File: | lib/CodeGen/CodeGenPrepare.cpp |
Warning: | line 3417, column 23 Called C++ object pointer is null |
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1 | //===- CodeGenPrepare.cpp - Prepare a function for code generation --------===// | ||||
2 | // | ||||
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | ||||
4 | // See https://llvm.org/LICENSE.txt for license information. | ||||
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | ||||
6 | // | ||||
7 | //===----------------------------------------------------------------------===// | ||||
8 | // | ||||
9 | // This pass munges the code in the input function to better prepare it for | ||||
10 | // SelectionDAG-based code generation. This works around limitations in it's | ||||
11 | // basic-block-at-a-time approach. It should eventually be removed. | ||||
12 | // | ||||
13 | //===----------------------------------------------------------------------===// | ||||
14 | |||||
15 | #include "llvm/ADT/APInt.h" | ||||
16 | #include "llvm/ADT/ArrayRef.h" | ||||
17 | #include "llvm/ADT/DenseMap.h" | ||||
18 | #include "llvm/ADT/MapVector.h" | ||||
19 | #include "llvm/ADT/PointerIntPair.h" | ||||
20 | #include "llvm/ADT/STLExtras.h" | ||||
21 | #include "llvm/ADT/SmallPtrSet.h" | ||||
22 | #include "llvm/ADT/SmallVector.h" | ||||
23 | #include "llvm/ADT/Statistic.h" | ||||
24 | #include "llvm/Analysis/BlockFrequencyInfo.h" | ||||
25 | #include "llvm/Analysis/BranchProbabilityInfo.h" | ||||
26 | #include "llvm/Analysis/ConstantFolding.h" | ||||
27 | #include "llvm/Analysis/InstructionSimplify.h" | ||||
28 | #include "llvm/Analysis/LoopInfo.h" | ||||
29 | #include "llvm/Analysis/MemoryBuiltins.h" | ||||
30 | #include "llvm/Analysis/ProfileSummaryInfo.h" | ||||
31 | #include "llvm/Analysis/TargetLibraryInfo.h" | ||||
32 | #include "llvm/Analysis/TargetTransformInfo.h" | ||||
33 | #include "llvm/Transforms/Utils/Local.h" | ||||
34 | #include "llvm/Analysis/ValueTracking.h" | ||||
35 | #include "llvm/Analysis/VectorUtils.h" | ||||
36 | #include "llvm/CodeGen/Analysis.h" | ||||
37 | #include "llvm/CodeGen/ISDOpcodes.h" | ||||
38 | #include "llvm/CodeGen/SelectionDAGNodes.h" | ||||
39 | #include "llvm/CodeGen/TargetLowering.h" | ||||
40 | #include "llvm/CodeGen/TargetPassConfig.h" | ||||
41 | #include "llvm/CodeGen/TargetSubtargetInfo.h" | ||||
42 | #include "llvm/CodeGen/ValueTypes.h" | ||||
43 | #include "llvm/Config/llvm-config.h" | ||||
44 | #include "llvm/IR/Argument.h" | ||||
45 | #include "llvm/IR/Attributes.h" | ||||
46 | #include "llvm/IR/BasicBlock.h" | ||||
47 | #include "llvm/IR/CallSite.h" | ||||
48 | #include "llvm/IR/Constant.h" | ||||
49 | #include "llvm/IR/Constants.h" | ||||
50 | #include "llvm/IR/DataLayout.h" | ||||
51 | #include "llvm/IR/DerivedTypes.h" | ||||
52 | #include "llvm/IR/Dominators.h" | ||||
53 | #include "llvm/IR/Function.h" | ||||
54 | #include "llvm/IR/GetElementPtrTypeIterator.h" | ||||
55 | #include "llvm/IR/GlobalValue.h" | ||||
56 | #include "llvm/IR/GlobalVariable.h" | ||||
57 | #include "llvm/IR/IRBuilder.h" | ||||
58 | #include "llvm/IR/InlineAsm.h" | ||||
59 | #include "llvm/IR/InstrTypes.h" | ||||
60 | #include "llvm/IR/Instruction.h" | ||||
61 | #include "llvm/IR/Instructions.h" | ||||
62 | #include "llvm/IR/IntrinsicInst.h" | ||||
63 | #include "llvm/IR/Intrinsics.h" | ||||
64 | #include "llvm/IR/LLVMContext.h" | ||||
65 | #include "llvm/IR/MDBuilder.h" | ||||
66 | #include "llvm/IR/Module.h" | ||||
67 | #include "llvm/IR/Operator.h" | ||||
68 | #include "llvm/IR/PatternMatch.h" | ||||
69 | #include "llvm/IR/Statepoint.h" | ||||
70 | #include "llvm/IR/Type.h" | ||||
71 | #include "llvm/IR/Use.h" | ||||
72 | #include "llvm/IR/User.h" | ||||
73 | #include "llvm/IR/Value.h" | ||||
74 | #include "llvm/IR/ValueHandle.h" | ||||
75 | #include "llvm/IR/ValueMap.h" | ||||
76 | #include "llvm/Pass.h" | ||||
77 | #include "llvm/Support/BlockFrequency.h" | ||||
78 | #include "llvm/Support/BranchProbability.h" | ||||
79 | #include "llvm/Support/Casting.h" | ||||
80 | #include "llvm/Support/CommandLine.h" | ||||
81 | #include "llvm/Support/Compiler.h" | ||||
82 | #include "llvm/Support/Debug.h" | ||||
83 | #include "llvm/Support/ErrorHandling.h" | ||||
84 | #include "llvm/Support/MachineValueType.h" | ||||
85 | #include "llvm/Support/MathExtras.h" | ||||
86 | #include "llvm/Support/raw_ostream.h" | ||||
87 | #include "llvm/Target/TargetMachine.h" | ||||
88 | #include "llvm/Target/TargetOptions.h" | ||||
89 | #include "llvm/Transforms/Utils/BasicBlockUtils.h" | ||||
90 | #include "llvm/Transforms/Utils/BypassSlowDivision.h" | ||||
91 | #include "llvm/Transforms/Utils/SimplifyLibCalls.h" | ||||
92 | #include <algorithm> | ||||
93 | #include <cassert> | ||||
94 | #include <cstdint> | ||||
95 | #include <iterator> | ||||
96 | #include <limits> | ||||
97 | #include <memory> | ||||
98 | #include <utility> | ||||
99 | #include <vector> | ||||
100 | |||||
101 | using namespace llvm; | ||||
102 | using namespace llvm::PatternMatch; | ||||
103 | |||||
104 | #define DEBUG_TYPE"codegenprepare" "codegenprepare" | ||||
105 | |||||
106 | STATISTIC(NumBlocksElim, "Number of blocks eliminated")static llvm::Statistic NumBlocksElim = {"codegenprepare", "NumBlocksElim" , "Number of blocks eliminated", {0}, {false}}; | ||||
107 | STATISTIC(NumPHIsElim, "Number of trivial PHIs eliminated")static llvm::Statistic NumPHIsElim = {"codegenprepare", "NumPHIsElim" , "Number of trivial PHIs eliminated", {0}, {false}}; | ||||
108 | STATISTIC(NumGEPsElim, "Number of GEPs converted to casts")static llvm::Statistic NumGEPsElim = {"codegenprepare", "NumGEPsElim" , "Number of GEPs converted to casts", {0}, {false}}; | ||||
109 | STATISTIC(NumCmpUses, "Number of uses of Cmp expressions replaced with uses of "static llvm::Statistic NumCmpUses = {"codegenprepare", "NumCmpUses" , "Number of uses of Cmp expressions replaced with uses of " "sunken Cmps" , {0}, {false}} | ||||
110 | "sunken Cmps")static llvm::Statistic NumCmpUses = {"codegenprepare", "NumCmpUses" , "Number of uses of Cmp expressions replaced with uses of " "sunken Cmps" , {0}, {false}}; | ||||
111 | STATISTIC(NumCastUses, "Number of uses of Cast expressions replaced with uses "static llvm::Statistic NumCastUses = {"codegenprepare", "NumCastUses" , "Number of uses of Cast expressions replaced with uses " "of sunken Casts" , {0}, {false}} | ||||
112 | "of sunken Casts")static llvm::Statistic NumCastUses = {"codegenprepare", "NumCastUses" , "Number of uses of Cast expressions replaced with uses " "of sunken Casts" , {0}, {false}}; | ||||
113 | STATISTIC(NumMemoryInsts, "Number of memory instructions whose address "static llvm::Statistic NumMemoryInsts = {"codegenprepare", "NumMemoryInsts" , "Number of memory instructions whose address " "computations were sunk" , {0}, {false}} | ||||
114 | "computations were sunk")static llvm::Statistic NumMemoryInsts = {"codegenprepare", "NumMemoryInsts" , "Number of memory instructions whose address " "computations were sunk" , {0}, {false}}; | ||||
115 | STATISTIC(NumMemoryInstsPhiCreated,static llvm::Statistic NumMemoryInstsPhiCreated = {"codegenprepare" , "NumMemoryInstsPhiCreated", "Number of phis created when address " "computations were sunk to memory instructions", {0}, {false }} | ||||
116 | "Number of phis created when address "static llvm::Statistic NumMemoryInstsPhiCreated = {"codegenprepare" , "NumMemoryInstsPhiCreated", "Number of phis created when address " "computations were sunk to memory instructions", {0}, {false }} | ||||
117 | "computations were sunk to memory instructions")static llvm::Statistic NumMemoryInstsPhiCreated = {"codegenprepare" , "NumMemoryInstsPhiCreated", "Number of phis created when address " "computations were sunk to memory instructions", {0}, {false }}; | ||||
118 | STATISTIC(NumMemoryInstsSelectCreated,static llvm::Statistic NumMemoryInstsSelectCreated = {"codegenprepare" , "NumMemoryInstsSelectCreated", "Number of select created when address " "computations were sunk to memory instructions", {0}, {false }} | ||||
119 | "Number of select created when address "static llvm::Statistic NumMemoryInstsSelectCreated = {"codegenprepare" , "NumMemoryInstsSelectCreated", "Number of select created when address " "computations were sunk to memory instructions", {0}, {false }} | ||||
120 | "computations were sunk to memory instructions")static llvm::Statistic NumMemoryInstsSelectCreated = {"codegenprepare" , "NumMemoryInstsSelectCreated", "Number of select created when address " "computations were sunk to memory instructions", {0}, {false }}; | ||||
121 | STATISTIC(NumExtsMoved, "Number of [s|z]ext instructions combined with loads")static llvm::Statistic NumExtsMoved = {"codegenprepare", "NumExtsMoved" , "Number of [s|z]ext instructions combined with loads", {0}, {false}}; | ||||
122 | STATISTIC(NumExtUses, "Number of uses of [s|z]ext instructions optimized")static llvm::Statistic NumExtUses = {"codegenprepare", "NumExtUses" , "Number of uses of [s|z]ext instructions optimized", {0}, { false}}; | ||||
123 | STATISTIC(NumAndsAdded,static llvm::Statistic NumAndsAdded = {"codegenprepare", "NumAndsAdded" , "Number of and mask instructions added to form ext loads", { 0}, {false}} | ||||
124 | "Number of and mask instructions added to form ext loads")static llvm::Statistic NumAndsAdded = {"codegenprepare", "NumAndsAdded" , "Number of and mask instructions added to form ext loads", { 0}, {false}}; | ||||
125 | STATISTIC(NumAndUses, "Number of uses of and mask instructions optimized")static llvm::Statistic NumAndUses = {"codegenprepare", "NumAndUses" , "Number of uses of and mask instructions optimized", {0}, { false}}; | ||||
126 | STATISTIC(NumRetsDup, "Number of return instructions duplicated")static llvm::Statistic NumRetsDup = {"codegenprepare", "NumRetsDup" , "Number of return instructions duplicated", {0}, {false}}; | ||||
127 | STATISTIC(NumDbgValueMoved, "Number of debug value instructions moved")static llvm::Statistic NumDbgValueMoved = {"codegenprepare", "NumDbgValueMoved" , "Number of debug value instructions moved", {0}, {false}}; | ||||
128 | STATISTIC(NumSelectsExpanded, "Number of selects turned into branches")static llvm::Statistic NumSelectsExpanded = {"codegenprepare" , "NumSelectsExpanded", "Number of selects turned into branches" , {0}, {false}}; | ||||
129 | STATISTIC(NumStoreExtractExposed, "Number of store(extractelement) exposed")static llvm::Statistic NumStoreExtractExposed = {"codegenprepare" , "NumStoreExtractExposed", "Number of store(extractelement) exposed" , {0}, {false}}; | ||||
130 | |||||
131 | static cl::opt<bool> DisableBranchOpts( | ||||
132 | "disable-cgp-branch-opts", cl::Hidden, cl::init(false), | ||||
133 | cl::desc("Disable branch optimizations in CodeGenPrepare")); | ||||
134 | |||||
135 | static cl::opt<bool> | ||||
136 | DisableGCOpts("disable-cgp-gc-opts", cl::Hidden, cl::init(false), | ||||
137 | cl::desc("Disable GC optimizations in CodeGenPrepare")); | ||||
138 | |||||
139 | static cl::opt<bool> DisableSelectToBranch( | ||||
140 | "disable-cgp-select2branch", cl::Hidden, cl::init(false), | ||||
141 | cl::desc("Disable select to branch conversion.")); | ||||
142 | |||||
143 | static cl::opt<bool> AddrSinkUsingGEPs( | ||||
144 | "addr-sink-using-gep", cl::Hidden, cl::init(true), | ||||
145 | cl::desc("Address sinking in CGP using GEPs.")); | ||||
146 | |||||
147 | static cl::opt<bool> EnableAndCmpSinking( | ||||
148 | "enable-andcmp-sinking", cl::Hidden, cl::init(true), | ||||
149 | cl::desc("Enable sinkinig and/cmp into branches.")); | ||||
150 | |||||
151 | static cl::opt<bool> DisableStoreExtract( | ||||
152 | "disable-cgp-store-extract", cl::Hidden, cl::init(false), | ||||
153 | cl::desc("Disable store(extract) optimizations in CodeGenPrepare")); | ||||
154 | |||||
155 | static cl::opt<bool> StressStoreExtract( | ||||
156 | "stress-cgp-store-extract", cl::Hidden, cl::init(false), | ||||
157 | cl::desc("Stress test store(extract) optimizations in CodeGenPrepare")); | ||||
158 | |||||
159 | static cl::opt<bool> DisableExtLdPromotion( | ||||
160 | "disable-cgp-ext-ld-promotion", cl::Hidden, cl::init(false), | ||||
161 | cl::desc("Disable ext(promotable(ld)) -> promoted(ext(ld)) optimization in " | ||||
162 | "CodeGenPrepare")); | ||||
163 | |||||
164 | static cl::opt<bool> StressExtLdPromotion( | ||||
165 | "stress-cgp-ext-ld-promotion", cl::Hidden, cl::init(false), | ||||
166 | cl::desc("Stress test ext(promotable(ld)) -> promoted(ext(ld)) " | ||||
167 | "optimization in CodeGenPrepare")); | ||||
168 | |||||
169 | static cl::opt<bool> DisablePreheaderProtect( | ||||
170 | "disable-preheader-prot", cl::Hidden, cl::init(false), | ||||
171 | cl::desc("Disable protection against removing loop preheaders")); | ||||
172 | |||||
173 | static cl::opt<bool> ProfileGuidedSectionPrefix( | ||||
174 | "profile-guided-section-prefix", cl::Hidden, cl::init(true), cl::ZeroOrMore, | ||||
175 | cl::desc("Use profile info to add section prefix for hot/cold functions")); | ||||
176 | |||||
177 | static cl::opt<unsigned> FreqRatioToSkipMerge( | ||||
178 | "cgp-freq-ratio-to-skip-merge", cl::Hidden, cl::init(2), | ||||
179 | cl::desc("Skip merging empty blocks if (frequency of empty block) / " | ||||
180 | "(frequency of destination block) is greater than this ratio")); | ||||
181 | |||||
182 | static cl::opt<bool> ForceSplitStore( | ||||
183 | "force-split-store", cl::Hidden, cl::init(false), | ||||
184 | cl::desc("Force store splitting no matter what the target query says.")); | ||||
185 | |||||
186 | static cl::opt<bool> | ||||
187 | EnableTypePromotionMerge("cgp-type-promotion-merge", cl::Hidden, | ||||
188 | cl::desc("Enable merging of redundant sexts when one is dominating" | ||||
189 | " the other."), cl::init(true)); | ||||
190 | |||||
191 | static cl::opt<bool> DisableComplexAddrModes( | ||||
192 | "disable-complex-addr-modes", cl::Hidden, cl::init(false), | ||||
193 | cl::desc("Disables combining addressing modes with different parts " | ||||
194 | "in optimizeMemoryInst.")); | ||||
195 | |||||
196 | static cl::opt<bool> | ||||
197 | AddrSinkNewPhis("addr-sink-new-phis", cl::Hidden, cl::init(false), | ||||
198 | cl::desc("Allow creation of Phis in Address sinking.")); | ||||
199 | |||||
200 | static cl::opt<bool> | ||||
201 | AddrSinkNewSelects("addr-sink-new-select", cl::Hidden, cl::init(true), | ||||
202 | cl::desc("Allow creation of selects in Address sinking.")); | ||||
203 | |||||
204 | static cl::opt<bool> AddrSinkCombineBaseReg( | ||||
205 | "addr-sink-combine-base-reg", cl::Hidden, cl::init(true), | ||||
206 | cl::desc("Allow combining of BaseReg field in Address sinking.")); | ||||
207 | |||||
208 | static cl::opt<bool> AddrSinkCombineBaseGV( | ||||
209 | "addr-sink-combine-base-gv", cl::Hidden, cl::init(true), | ||||
210 | cl::desc("Allow combining of BaseGV field in Address sinking.")); | ||||
211 | |||||
212 | static cl::opt<bool> AddrSinkCombineBaseOffs( | ||||
213 | "addr-sink-combine-base-offs", cl::Hidden, cl::init(true), | ||||
214 | cl::desc("Allow combining of BaseOffs field in Address sinking.")); | ||||
215 | |||||
216 | static cl::opt<bool> AddrSinkCombineScaledReg( | ||||
217 | "addr-sink-combine-scaled-reg", cl::Hidden, cl::init(true), | ||||
218 | cl::desc("Allow combining of ScaledReg field in Address sinking.")); | ||||
219 | |||||
220 | static cl::opt<bool> | ||||
221 | EnableGEPOffsetSplit("cgp-split-large-offset-gep", cl::Hidden, | ||||
222 | cl::init(true), | ||||
223 | cl::desc("Enable splitting large offset of GEP.")); | ||||
224 | |||||
225 | namespace { | ||||
226 | |||||
227 | enum ExtType { | ||||
228 | ZeroExtension, // Zero extension has been seen. | ||||
229 | SignExtension, // Sign extension has been seen. | ||||
230 | BothExtension // This extension type is used if we saw sext after | ||||
231 | // ZeroExtension had been set, or if we saw zext after | ||||
232 | // SignExtension had been set. It makes the type | ||||
233 | // information of a promoted instruction invalid. | ||||
234 | }; | ||||
235 | |||||
236 | using SetOfInstrs = SmallPtrSet<Instruction *, 16>; | ||||
237 | using TypeIsSExt = PointerIntPair<Type *, 2, ExtType>; | ||||
238 | using InstrToOrigTy = DenseMap<Instruction *, TypeIsSExt>; | ||||
239 | using SExts = SmallVector<Instruction *, 16>; | ||||
240 | using ValueToSExts = DenseMap<Value *, SExts>; | ||||
241 | |||||
242 | class TypePromotionTransaction; | ||||
243 | |||||
244 | class CodeGenPrepare : public FunctionPass { | ||||
245 | const TargetMachine *TM = nullptr; | ||||
246 | const TargetSubtargetInfo *SubtargetInfo; | ||||
247 | const TargetLowering *TLI = nullptr; | ||||
248 | const TargetRegisterInfo *TRI; | ||||
249 | const TargetTransformInfo *TTI = nullptr; | ||||
250 | const TargetLibraryInfo *TLInfo; | ||||
251 | const LoopInfo *LI; | ||||
252 | std::unique_ptr<BlockFrequencyInfo> BFI; | ||||
253 | std::unique_ptr<BranchProbabilityInfo> BPI; | ||||
254 | |||||
255 | /// As we scan instructions optimizing them, this is the next instruction | ||||
256 | /// to optimize. Transforms that can invalidate this should update it. | ||||
257 | BasicBlock::iterator CurInstIterator; | ||||
258 | |||||
259 | /// Keeps track of non-local addresses that have been sunk into a block. | ||||
260 | /// This allows us to avoid inserting duplicate code for blocks with | ||||
261 | /// multiple load/stores of the same address. The usage of WeakTrackingVH | ||||
262 | /// enables SunkAddrs to be treated as a cache whose entries can be | ||||
263 | /// invalidated if a sunken address computation has been erased. | ||||
264 | ValueMap<Value*, WeakTrackingVH> SunkAddrs; | ||||
265 | |||||
266 | /// Keeps track of all instructions inserted for the current function. | ||||
267 | SetOfInstrs InsertedInsts; | ||||
268 | |||||
269 | /// Keeps track of the type of the related instruction before their | ||||
270 | /// promotion for the current function. | ||||
271 | InstrToOrigTy PromotedInsts; | ||||
272 | |||||
273 | /// Keep track of instructions removed during promotion. | ||||
274 | SetOfInstrs RemovedInsts; | ||||
275 | |||||
276 | /// Keep track of sext chains based on their initial value. | ||||
277 | DenseMap<Value *, Instruction *> SeenChainsForSExt; | ||||
278 | |||||
279 | /// Keep track of GEPs accessing the same data structures such as structs or | ||||
280 | /// arrays that are candidates to be split later because of their large | ||||
281 | /// size. | ||||
282 | MapVector< | ||||
283 | AssertingVH<Value>, | ||||
284 | SmallVector<std::pair<AssertingVH<GetElementPtrInst>, int64_t>, 32>> | ||||
285 | LargeOffsetGEPMap; | ||||
286 | |||||
287 | /// Keep track of new GEP base after splitting the GEPs having large offset. | ||||
288 | SmallSet<AssertingVH<Value>, 2> NewGEPBases; | ||||
289 | |||||
290 | /// Map serial numbers to Large offset GEPs. | ||||
291 | DenseMap<AssertingVH<GetElementPtrInst>, int> LargeOffsetGEPID; | ||||
292 | |||||
293 | /// Keep track of SExt promoted. | ||||
294 | ValueToSExts ValToSExtendedUses; | ||||
295 | |||||
296 | /// True if optimizing for size. | ||||
297 | bool OptSize; | ||||
298 | |||||
299 | /// DataLayout for the Function being processed. | ||||
300 | const DataLayout *DL = nullptr; | ||||
301 | |||||
302 | /// Building the dominator tree can be expensive, so we only build it | ||||
303 | /// lazily and update it when required. | ||||
304 | std::unique_ptr<DominatorTree> DT; | ||||
305 | |||||
306 | public: | ||||
307 | static char ID; // Pass identification, replacement for typeid | ||||
308 | |||||
309 | CodeGenPrepare() : FunctionPass(ID) { | ||||
310 | initializeCodeGenPreparePass(*PassRegistry::getPassRegistry()); | ||||
311 | } | ||||
312 | |||||
313 | bool runOnFunction(Function &F) override; | ||||
314 | |||||
315 | StringRef getPassName() const override { return "CodeGen Prepare"; } | ||||
316 | |||||
317 | void getAnalysisUsage(AnalysisUsage &AU) const override { | ||||
318 | // FIXME: When we can selectively preserve passes, preserve the domtree. | ||||
319 | AU.addRequired<ProfileSummaryInfoWrapperPass>(); | ||||
320 | AU.addRequired<TargetLibraryInfoWrapperPass>(); | ||||
321 | AU.addRequired<TargetTransformInfoWrapperPass>(); | ||||
322 | AU.addRequired<LoopInfoWrapperPass>(); | ||||
323 | } | ||||
324 | |||||
325 | private: | ||||
326 | template <typename F> | ||||
327 | void resetIteratorIfInvalidatedWhileCalling(BasicBlock *BB, F f) { | ||||
328 | // Substituting can cause recursive simplifications, which can invalidate | ||||
329 | // our iterator. Use a WeakTrackingVH to hold onto it in case this | ||||
330 | // happens. | ||||
331 | Value *CurValue = &*CurInstIterator; | ||||
332 | WeakTrackingVH IterHandle(CurValue); | ||||
333 | |||||
334 | f(); | ||||
335 | |||||
336 | // If the iterator instruction was recursively deleted, start over at the | ||||
337 | // start of the block. | ||||
338 | if (IterHandle != CurValue) { | ||||
339 | CurInstIterator = BB->begin(); | ||||
340 | SunkAddrs.clear(); | ||||
341 | } | ||||
342 | } | ||||
343 | |||||
344 | // Get the DominatorTree, building if necessary. | ||||
345 | DominatorTree &getDT(Function &F) { | ||||
346 | if (!DT) | ||||
347 | DT = std::make_unique<DominatorTree>(F); | ||||
348 | return *DT; | ||||
349 | } | ||||
350 | |||||
351 | bool eliminateFallThrough(Function &F); | ||||
352 | bool eliminateMostlyEmptyBlocks(Function &F); | ||||
353 | BasicBlock *findDestBlockOfMergeableEmptyBlock(BasicBlock *BB); | ||||
354 | bool canMergeBlocks(const BasicBlock *BB, const BasicBlock *DestBB) const; | ||||
355 | void eliminateMostlyEmptyBlock(BasicBlock *BB); | ||||
356 | bool isMergingEmptyBlockProfitable(BasicBlock *BB, BasicBlock *DestBB, | ||||
357 | bool isPreheader); | ||||
358 | bool optimizeBlock(BasicBlock &BB, bool &ModifiedDT); | ||||
359 | bool optimizeInst(Instruction *I, bool &ModifiedDT); | ||||
360 | bool optimizeMemoryInst(Instruction *MemoryInst, Value *Addr, | ||||
361 | Type *AccessTy, unsigned AddrSpace); | ||||
362 | bool optimizeInlineAsmInst(CallInst *CS); | ||||
363 | bool optimizeCallInst(CallInst *CI, bool &ModifiedDT); | ||||
364 | bool optimizeExt(Instruction *&I); | ||||
365 | bool optimizeExtUses(Instruction *I); | ||||
366 | bool optimizeLoadExt(LoadInst *Load); | ||||
367 | bool optimizeShiftInst(BinaryOperator *BO); | ||||
368 | bool optimizeSelectInst(SelectInst *SI); | ||||
369 | bool optimizeShuffleVectorInst(ShuffleVectorInst *SVI); | ||||
370 | bool optimizeSwitchInst(SwitchInst *SI); | ||||
371 | bool optimizeExtractElementInst(Instruction *Inst); | ||||
372 | bool dupRetToEnableTailCallOpts(BasicBlock *BB, bool &ModifiedDT); | ||||
373 | bool placeDbgValues(Function &F); | ||||
374 | bool canFormExtLd(const SmallVectorImpl<Instruction *> &MovedExts, | ||||
375 | LoadInst *&LI, Instruction *&Inst, bool HasPromoted); | ||||
376 | bool tryToPromoteExts(TypePromotionTransaction &TPT, | ||||
377 | const SmallVectorImpl<Instruction *> &Exts, | ||||
378 | SmallVectorImpl<Instruction *> &ProfitablyMovedExts, | ||||
379 | unsigned CreatedInstsCost = 0); | ||||
380 | bool mergeSExts(Function &F); | ||||
381 | bool splitLargeGEPOffsets(); | ||||
382 | bool performAddressTypePromotion( | ||||
383 | Instruction *&Inst, | ||||
384 | bool AllowPromotionWithoutCommonHeader, | ||||
385 | bool HasPromoted, TypePromotionTransaction &TPT, | ||||
386 | SmallVectorImpl<Instruction *> &SpeculativelyMovedExts); | ||||
387 | bool splitBranchCondition(Function &F, bool &ModifiedDT); | ||||
388 | bool simplifyOffsetableRelocate(Instruction &I); | ||||
389 | |||||
390 | bool tryToSinkFreeOperands(Instruction *I); | ||||
391 | bool replaceMathCmpWithIntrinsic(BinaryOperator *BO, CmpInst *Cmp, | ||||
392 | Intrinsic::ID IID); | ||||
393 | bool optimizeCmp(CmpInst *Cmp, bool &ModifiedDT); | ||||
394 | bool combineToUSubWithOverflow(CmpInst *Cmp, bool &ModifiedDT); | ||||
395 | bool combineToUAddWithOverflow(CmpInst *Cmp, bool &ModifiedDT); | ||||
396 | }; | ||||
397 | |||||
398 | } // end anonymous namespace | ||||
399 | |||||
400 | char CodeGenPrepare::ID = 0; | ||||
401 | |||||
402 | INITIALIZE_PASS_BEGIN(CodeGenPrepare, DEBUG_TYPE,static void *initializeCodeGenPreparePassOnce(PassRegistry & Registry) { | ||||
403 | "Optimize for code generation", false, false)static void *initializeCodeGenPreparePassOnce(PassRegistry & Registry) { | ||||
404 | INITIALIZE_PASS_DEPENDENCY(ProfileSummaryInfoWrapperPass)initializeProfileSummaryInfoWrapperPassPass(Registry); | ||||
405 | INITIALIZE_PASS_END(CodeGenPrepare, DEBUG_TYPE,PassInfo *PI = new PassInfo( "Optimize for code generation", "codegenprepare" , &CodeGenPrepare::ID, PassInfo::NormalCtor_t(callDefaultCtor <CodeGenPrepare>), false, false); Registry.registerPass (*PI, true); return PI; } static llvm::once_flag InitializeCodeGenPreparePassFlag ; void llvm::initializeCodeGenPreparePass(PassRegistry &Registry ) { llvm::call_once(InitializeCodeGenPreparePassFlag, initializeCodeGenPreparePassOnce , std::ref(Registry)); } | ||||
406 | "Optimize for code generation", false, false)PassInfo *PI = new PassInfo( "Optimize for code generation", "codegenprepare" , &CodeGenPrepare::ID, PassInfo::NormalCtor_t(callDefaultCtor <CodeGenPrepare>), false, false); Registry.registerPass (*PI, true); return PI; } static llvm::once_flag InitializeCodeGenPreparePassFlag ; void llvm::initializeCodeGenPreparePass(PassRegistry &Registry ) { llvm::call_once(InitializeCodeGenPreparePassFlag, initializeCodeGenPreparePassOnce , std::ref(Registry)); } | ||||
407 | |||||
408 | FunctionPass *llvm::createCodeGenPreparePass() { return new CodeGenPrepare(); } | ||||
409 | |||||
410 | bool CodeGenPrepare::runOnFunction(Function &F) { | ||||
411 | if (skipFunction(F)) | ||||
412 | return false; | ||||
413 | |||||
414 | DL = &F.getParent()->getDataLayout(); | ||||
415 | |||||
416 | bool EverMadeChange = false; | ||||
417 | // Clear per function information. | ||||
418 | InsertedInsts.clear(); | ||||
419 | PromotedInsts.clear(); | ||||
420 | |||||
421 | if (auto *TPC = getAnalysisIfAvailable<TargetPassConfig>()) { | ||||
422 | TM = &TPC->getTM<TargetMachine>(); | ||||
423 | SubtargetInfo = TM->getSubtargetImpl(F); | ||||
424 | TLI = SubtargetInfo->getTargetLowering(); | ||||
425 | TRI = SubtargetInfo->getRegisterInfo(); | ||||
426 | } | ||||
427 | TLInfo = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(F); | ||||
428 | TTI = &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F); | ||||
429 | LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo(); | ||||
430 | BPI.reset(new BranchProbabilityInfo(F, *LI)); | ||||
431 | BFI.reset(new BlockFrequencyInfo(F, *BPI, *LI)); | ||||
432 | OptSize = F.hasOptSize(); | ||||
433 | |||||
434 | ProfileSummaryInfo *PSI = | ||||
435 | &getAnalysis<ProfileSummaryInfoWrapperPass>().getPSI(); | ||||
436 | if (ProfileGuidedSectionPrefix) { | ||||
437 | if (PSI->isFunctionHotInCallGraph(&F, *BFI)) | ||||
438 | F.setSectionPrefix(".hot"); | ||||
439 | else if (PSI->isFunctionColdInCallGraph(&F, *BFI)) | ||||
440 | F.setSectionPrefix(".unlikely"); | ||||
441 | } | ||||
442 | |||||
443 | /// This optimization identifies DIV instructions that can be | ||||
444 | /// profitably bypassed and carried out with a shorter, faster divide. | ||||
445 | if (!OptSize && !PSI->hasHugeWorkingSetSize() && TLI && | ||||
446 | TLI->isSlowDivBypassed()) { | ||||
447 | const DenseMap<unsigned int, unsigned int> &BypassWidths = | ||||
448 | TLI->getBypassSlowDivWidths(); | ||||
449 | BasicBlock* BB = &*F.begin(); | ||||
450 | while (BB != nullptr) { | ||||
451 | // bypassSlowDivision may create new BBs, but we don't want to reapply the | ||||
452 | // optimization to those blocks. | ||||
453 | BasicBlock* Next = BB->getNextNode(); | ||||
454 | EverMadeChange |= bypassSlowDivision(BB, BypassWidths); | ||||
455 | BB = Next; | ||||
456 | } | ||||
457 | } | ||||
458 | |||||
459 | // Eliminate blocks that contain only PHI nodes and an | ||||
460 | // unconditional branch. | ||||
461 | EverMadeChange |= eliminateMostlyEmptyBlocks(F); | ||||
462 | |||||
463 | bool ModifiedDT = false; | ||||
464 | if (!DisableBranchOpts) | ||||
465 | EverMadeChange |= splitBranchCondition(F, ModifiedDT); | ||||
466 | |||||
467 | // Split some critical edges where one of the sources is an indirect branch, | ||||
468 | // to help generate sane code for PHIs involving such edges. | ||||
469 | EverMadeChange |= SplitIndirectBrCriticalEdges(F); | ||||
470 | |||||
471 | bool MadeChange = true; | ||||
472 | while (MadeChange) { | ||||
473 | MadeChange = false; | ||||
474 | DT.reset(); | ||||
475 | for (Function::iterator I = F.begin(); I != F.end(); ) { | ||||
476 | BasicBlock *BB = &*I++; | ||||
477 | bool ModifiedDTOnIteration = false; | ||||
478 | MadeChange |= optimizeBlock(*BB, ModifiedDTOnIteration); | ||||
479 | |||||
480 | // Restart BB iteration if the dominator tree of the Function was changed | ||||
481 | if (ModifiedDTOnIteration) | ||||
482 | break; | ||||
483 | } | ||||
484 | if (EnableTypePromotionMerge && !ValToSExtendedUses.empty()) | ||||
485 | MadeChange |= mergeSExts(F); | ||||
486 | if (!LargeOffsetGEPMap.empty()) | ||||
487 | MadeChange |= splitLargeGEPOffsets(); | ||||
488 | |||||
489 | // Really free removed instructions during promotion. | ||||
490 | for (Instruction *I : RemovedInsts) | ||||
491 | I->deleteValue(); | ||||
492 | |||||
493 | EverMadeChange |= MadeChange; | ||||
494 | SeenChainsForSExt.clear(); | ||||
495 | ValToSExtendedUses.clear(); | ||||
496 | RemovedInsts.clear(); | ||||
497 | LargeOffsetGEPMap.clear(); | ||||
498 | LargeOffsetGEPID.clear(); | ||||
499 | } | ||||
500 | |||||
501 | SunkAddrs.clear(); | ||||
502 | |||||
503 | if (!DisableBranchOpts) { | ||||
504 | MadeChange = false; | ||||
505 | // Use a set vector to get deterministic iteration order. The order the | ||||
506 | // blocks are removed may affect whether or not PHI nodes in successors | ||||
507 | // are removed. | ||||
508 | SmallSetVector<BasicBlock*, 8> WorkList; | ||||
509 | for (BasicBlock &BB : F) { | ||||
510 | SmallVector<BasicBlock *, 2> Successors(succ_begin(&BB), succ_end(&BB)); | ||||
511 | MadeChange |= ConstantFoldTerminator(&BB, true); | ||||
512 | if (!MadeChange) continue; | ||||
513 | |||||
514 | for (SmallVectorImpl<BasicBlock*>::iterator | ||||
515 | II = Successors.begin(), IE = Successors.end(); II != IE; ++II) | ||||
516 | if (pred_begin(*II) == pred_end(*II)) | ||||
517 | WorkList.insert(*II); | ||||
518 | } | ||||
519 | |||||
520 | // Delete the dead blocks and any of their dead successors. | ||||
521 | MadeChange |= !WorkList.empty(); | ||||
522 | while (!WorkList.empty()) { | ||||
523 | BasicBlock *BB = WorkList.pop_back_val(); | ||||
524 | SmallVector<BasicBlock*, 2> Successors(succ_begin(BB), succ_end(BB)); | ||||
525 | |||||
526 | DeleteDeadBlock(BB); | ||||
527 | |||||
528 | for (SmallVectorImpl<BasicBlock*>::iterator | ||||
529 | II = Successors.begin(), IE = Successors.end(); II != IE; ++II) | ||||
530 | if (pred_begin(*II) == pred_end(*II)) | ||||
531 | WorkList.insert(*II); | ||||
532 | } | ||||
533 | |||||
534 | // Merge pairs of basic blocks with unconditional branches, connected by | ||||
535 | // a single edge. | ||||
536 | if (EverMadeChange || MadeChange) | ||||
537 | MadeChange |= eliminateFallThrough(F); | ||||
538 | |||||
539 | EverMadeChange |= MadeChange; | ||||
540 | } | ||||
541 | |||||
542 | if (!DisableGCOpts) { | ||||
543 | SmallVector<Instruction *, 2> Statepoints; | ||||
544 | for (BasicBlock &BB : F) | ||||
545 | for (Instruction &I : BB) | ||||
546 | if (isStatepoint(I)) | ||||
547 | Statepoints.push_back(&I); | ||||
548 | for (auto &I : Statepoints) | ||||
549 | EverMadeChange |= simplifyOffsetableRelocate(*I); | ||||
550 | } | ||||
551 | |||||
552 | // Do this last to clean up use-before-def scenarios introduced by other | ||||
553 | // preparatory transforms. | ||||
554 | EverMadeChange |= placeDbgValues(F); | ||||
555 | |||||
556 | return EverMadeChange; | ||||
557 | } | ||||
558 | |||||
559 | /// Merge basic blocks which are connected by a single edge, where one of the | ||||
560 | /// basic blocks has a single successor pointing to the other basic block, | ||||
561 | /// which has a single predecessor. | ||||
562 | bool CodeGenPrepare::eliminateFallThrough(Function &F) { | ||||
563 | bool Changed = false; | ||||
564 | // Scan all of the blocks in the function, except for the entry block. | ||||
565 | // Use a temporary array to avoid iterator being invalidated when | ||||
566 | // deleting blocks. | ||||
567 | SmallVector<WeakTrackingVH, 16> Blocks; | ||||
568 | for (auto &Block : llvm::make_range(std::next(F.begin()), F.end())) | ||||
569 | Blocks.push_back(&Block); | ||||
570 | |||||
571 | for (auto &Block : Blocks) { | ||||
572 | auto *BB = cast_or_null<BasicBlock>(Block); | ||||
573 | if (!BB) | ||||
574 | continue; | ||||
575 | // If the destination block has a single pred, then this is a trivial | ||||
576 | // edge, just collapse it. | ||||
577 | BasicBlock *SinglePred = BB->getSinglePredecessor(); | ||||
578 | |||||
579 | // Don't merge if BB's address is taken. | ||||
580 | if (!SinglePred || SinglePred == BB || BB->hasAddressTaken()) continue; | ||||
581 | |||||
582 | BranchInst *Term = dyn_cast<BranchInst>(SinglePred->getTerminator()); | ||||
583 | if (Term && !Term->isConditional()) { | ||||
584 | Changed = true; | ||||
585 | LLVM_DEBUG(dbgs() << "To merge:\n" << *BB << "\n\n\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "To merge:\n" << * BB << "\n\n\n"; } } while (false); | ||||
586 | |||||
587 | // Merge BB into SinglePred and delete it. | ||||
588 | MergeBlockIntoPredecessor(BB); | ||||
589 | } | ||||
590 | } | ||||
591 | return Changed; | ||||
592 | } | ||||
593 | |||||
594 | /// Find a destination block from BB if BB is mergeable empty block. | ||||
595 | BasicBlock *CodeGenPrepare::findDestBlockOfMergeableEmptyBlock(BasicBlock *BB) { | ||||
596 | // If this block doesn't end with an uncond branch, ignore it. | ||||
597 | BranchInst *BI = dyn_cast<BranchInst>(BB->getTerminator()); | ||||
598 | if (!BI || !BI->isUnconditional()) | ||||
599 | return nullptr; | ||||
600 | |||||
601 | // If the instruction before the branch (skipping debug info) isn't a phi | ||||
602 | // node, then other stuff is happening here. | ||||
603 | BasicBlock::iterator BBI = BI->getIterator(); | ||||
604 | if (BBI != BB->begin()) { | ||||
605 | --BBI; | ||||
606 | while (isa<DbgInfoIntrinsic>(BBI)) { | ||||
607 | if (BBI == BB->begin()) | ||||
608 | break; | ||||
609 | --BBI; | ||||
610 | } | ||||
611 | if (!isa<DbgInfoIntrinsic>(BBI) && !isa<PHINode>(BBI)) | ||||
612 | return nullptr; | ||||
613 | } | ||||
614 | |||||
615 | // Do not break infinite loops. | ||||
616 | BasicBlock *DestBB = BI->getSuccessor(0); | ||||
617 | if (DestBB == BB) | ||||
618 | return nullptr; | ||||
619 | |||||
620 | if (!canMergeBlocks(BB, DestBB)) | ||||
621 | DestBB = nullptr; | ||||
622 | |||||
623 | return DestBB; | ||||
624 | } | ||||
625 | |||||
626 | /// Eliminate blocks that contain only PHI nodes, debug info directives, and an | ||||
627 | /// unconditional branch. Passes before isel (e.g. LSR/loopsimplify) often split | ||||
628 | /// edges in ways that are non-optimal for isel. Start by eliminating these | ||||
629 | /// blocks so we can split them the way we want them. | ||||
630 | bool CodeGenPrepare::eliminateMostlyEmptyBlocks(Function &F) { | ||||
631 | SmallPtrSet<BasicBlock *, 16> Preheaders; | ||||
632 | SmallVector<Loop *, 16> LoopList(LI->begin(), LI->end()); | ||||
633 | while (!LoopList.empty()) { | ||||
634 | Loop *L = LoopList.pop_back_val(); | ||||
635 | LoopList.insert(LoopList.end(), L->begin(), L->end()); | ||||
636 | if (BasicBlock *Preheader = L->getLoopPreheader()) | ||||
637 | Preheaders.insert(Preheader); | ||||
638 | } | ||||
639 | |||||
640 | bool MadeChange = false; | ||||
641 | // Copy blocks into a temporary array to avoid iterator invalidation issues | ||||
642 | // as we remove them. | ||||
643 | // Note that this intentionally skips the entry block. | ||||
644 | SmallVector<WeakTrackingVH, 16> Blocks; | ||||
645 | for (auto &Block : llvm::make_range(std::next(F.begin()), F.end())) | ||||
646 | Blocks.push_back(&Block); | ||||
647 | |||||
648 | for (auto &Block : Blocks) { | ||||
649 | BasicBlock *BB = cast_or_null<BasicBlock>(Block); | ||||
650 | if (!BB) | ||||
651 | continue; | ||||
652 | BasicBlock *DestBB = findDestBlockOfMergeableEmptyBlock(BB); | ||||
653 | if (!DestBB || | ||||
654 | !isMergingEmptyBlockProfitable(BB, DestBB, Preheaders.count(BB))) | ||||
655 | continue; | ||||
656 | |||||
657 | eliminateMostlyEmptyBlock(BB); | ||||
658 | MadeChange = true; | ||||
659 | } | ||||
660 | return MadeChange; | ||||
661 | } | ||||
662 | |||||
663 | bool CodeGenPrepare::isMergingEmptyBlockProfitable(BasicBlock *BB, | ||||
664 | BasicBlock *DestBB, | ||||
665 | bool isPreheader) { | ||||
666 | // Do not delete loop preheaders if doing so would create a critical edge. | ||||
667 | // Loop preheaders can be good locations to spill registers. If the | ||||
668 | // preheader is deleted and we create a critical edge, registers may be | ||||
669 | // spilled in the loop body instead. | ||||
670 | if (!DisablePreheaderProtect && isPreheader && | ||||
671 | !(BB->getSinglePredecessor() && | ||||
672 | BB->getSinglePredecessor()->getSingleSuccessor())) | ||||
673 | return false; | ||||
674 | |||||
675 | // Skip merging if the block's successor is also a successor to any callbr | ||||
676 | // that leads to this block. | ||||
677 | // FIXME: Is this really needed? Is this a correctness issue? | ||||
678 | for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) { | ||||
679 | if (auto *CBI = dyn_cast<CallBrInst>((*PI)->getTerminator())) | ||||
680 | for (unsigned i = 0, e = CBI->getNumSuccessors(); i != e; ++i) | ||||
681 | if (DestBB == CBI->getSuccessor(i)) | ||||
682 | return false; | ||||
683 | } | ||||
684 | |||||
685 | // Try to skip merging if the unique predecessor of BB is terminated by a | ||||
686 | // switch or indirect branch instruction, and BB is used as an incoming block | ||||
687 | // of PHIs in DestBB. In such case, merging BB and DestBB would cause ISel to | ||||
688 | // add COPY instructions in the predecessor of BB instead of BB (if it is not | ||||
689 | // merged). Note that the critical edge created by merging such blocks wont be | ||||
690 | // split in MachineSink because the jump table is not analyzable. By keeping | ||||
691 | // such empty block (BB), ISel will place COPY instructions in BB, not in the | ||||
692 | // predecessor of BB. | ||||
693 | BasicBlock *Pred = BB->getUniquePredecessor(); | ||||
694 | if (!Pred || | ||||
695 | !(isa<SwitchInst>(Pred->getTerminator()) || | ||||
696 | isa<IndirectBrInst>(Pred->getTerminator()))) | ||||
697 | return true; | ||||
698 | |||||
699 | if (BB->getTerminator() != BB->getFirstNonPHIOrDbg()) | ||||
700 | return true; | ||||
701 | |||||
702 | // We use a simple cost heuristic which determine skipping merging is | ||||
703 | // profitable if the cost of skipping merging is less than the cost of | ||||
704 | // merging : Cost(skipping merging) < Cost(merging BB), where the | ||||
705 | // Cost(skipping merging) is Freq(BB) * (Cost(Copy) + Cost(Branch)), and | ||||
706 | // the Cost(merging BB) is Freq(Pred) * Cost(Copy). | ||||
707 | // Assuming Cost(Copy) == Cost(Branch), we could simplify it to : | ||||
708 | // Freq(Pred) / Freq(BB) > 2. | ||||
709 | // Note that if there are multiple empty blocks sharing the same incoming | ||||
710 | // value for the PHIs in the DestBB, we consider them together. In such | ||||
711 | // case, Cost(merging BB) will be the sum of their frequencies. | ||||
712 | |||||
713 | if (!isa<PHINode>(DestBB->begin())) | ||||
714 | return true; | ||||
715 | |||||
716 | SmallPtrSet<BasicBlock *, 16> SameIncomingValueBBs; | ||||
717 | |||||
718 | // Find all other incoming blocks from which incoming values of all PHIs in | ||||
719 | // DestBB are the same as the ones from BB. | ||||
720 | for (pred_iterator PI = pred_begin(DestBB), E = pred_end(DestBB); PI != E; | ||||
721 | ++PI) { | ||||
722 | BasicBlock *DestBBPred = *PI; | ||||
723 | if (DestBBPred == BB) | ||||
724 | continue; | ||||
725 | |||||
726 | if (llvm::all_of(DestBB->phis(), [&](const PHINode &DestPN) { | ||||
727 | return DestPN.getIncomingValueForBlock(BB) == | ||||
728 | DestPN.getIncomingValueForBlock(DestBBPred); | ||||
729 | })) | ||||
730 | SameIncomingValueBBs.insert(DestBBPred); | ||||
731 | } | ||||
732 | |||||
733 | // See if all BB's incoming values are same as the value from Pred. In this | ||||
734 | // case, no reason to skip merging because COPYs are expected to be place in | ||||
735 | // Pred already. | ||||
736 | if (SameIncomingValueBBs.count(Pred)) | ||||
737 | return true; | ||||
738 | |||||
739 | BlockFrequency PredFreq = BFI->getBlockFreq(Pred); | ||||
740 | BlockFrequency BBFreq = BFI->getBlockFreq(BB); | ||||
741 | |||||
742 | for (auto SameValueBB : SameIncomingValueBBs) | ||||
743 | if (SameValueBB->getUniquePredecessor() == Pred && | ||||
744 | DestBB == findDestBlockOfMergeableEmptyBlock(SameValueBB)) | ||||
745 | BBFreq += BFI->getBlockFreq(SameValueBB); | ||||
746 | |||||
747 | return PredFreq.getFrequency() <= | ||||
748 | BBFreq.getFrequency() * FreqRatioToSkipMerge; | ||||
749 | } | ||||
750 | |||||
751 | /// Return true if we can merge BB into DestBB if there is a single | ||||
752 | /// unconditional branch between them, and BB contains no other non-phi | ||||
753 | /// instructions. | ||||
754 | bool CodeGenPrepare::canMergeBlocks(const BasicBlock *BB, | ||||
755 | const BasicBlock *DestBB) const { | ||||
756 | // We only want to eliminate blocks whose phi nodes are used by phi nodes in | ||||
757 | // the successor. If there are more complex condition (e.g. preheaders), | ||||
758 | // don't mess around with them. | ||||
759 | for (const PHINode &PN : BB->phis()) { | ||||
760 | for (const User *U : PN.users()) { | ||||
761 | const Instruction *UI = cast<Instruction>(U); | ||||
762 | if (UI->getParent() != DestBB || !isa<PHINode>(UI)) | ||||
763 | return false; | ||||
764 | // If User is inside DestBB block and it is a PHINode then check | ||||
765 | // incoming value. If incoming value is not from BB then this is | ||||
766 | // a complex condition (e.g. preheaders) we want to avoid here. | ||||
767 | if (UI->getParent() == DestBB) { | ||||
768 | if (const PHINode *UPN = dyn_cast<PHINode>(UI)) | ||||
769 | for (unsigned I = 0, E = UPN->getNumIncomingValues(); I != E; ++I) { | ||||
770 | Instruction *Insn = dyn_cast<Instruction>(UPN->getIncomingValue(I)); | ||||
771 | if (Insn && Insn->getParent() == BB && | ||||
772 | Insn->getParent() != UPN->getIncomingBlock(I)) | ||||
773 | return false; | ||||
774 | } | ||||
775 | } | ||||
776 | } | ||||
777 | } | ||||
778 | |||||
779 | // If BB and DestBB contain any common predecessors, then the phi nodes in BB | ||||
780 | // and DestBB may have conflicting incoming values for the block. If so, we | ||||
781 | // can't merge the block. | ||||
782 | const PHINode *DestBBPN = dyn_cast<PHINode>(DestBB->begin()); | ||||
783 | if (!DestBBPN) return true; // no conflict. | ||||
784 | |||||
785 | // Collect the preds of BB. | ||||
786 | SmallPtrSet<const BasicBlock*, 16> BBPreds; | ||||
787 | if (const PHINode *BBPN = dyn_cast<PHINode>(BB->begin())) { | ||||
788 | // It is faster to get preds from a PHI than with pred_iterator. | ||||
789 | for (unsigned i = 0, e = BBPN->getNumIncomingValues(); i != e; ++i) | ||||
790 | BBPreds.insert(BBPN->getIncomingBlock(i)); | ||||
791 | } else { | ||||
792 | BBPreds.insert(pred_begin(BB), pred_end(BB)); | ||||
793 | } | ||||
794 | |||||
795 | // Walk the preds of DestBB. | ||||
796 | for (unsigned i = 0, e = DestBBPN->getNumIncomingValues(); i != e; ++i) { | ||||
797 | BasicBlock *Pred = DestBBPN->getIncomingBlock(i); | ||||
798 | if (BBPreds.count(Pred)) { // Common predecessor? | ||||
799 | for (const PHINode &PN : DestBB->phis()) { | ||||
800 | const Value *V1 = PN.getIncomingValueForBlock(Pred); | ||||
801 | const Value *V2 = PN.getIncomingValueForBlock(BB); | ||||
802 | |||||
803 | // If V2 is a phi node in BB, look up what the mapped value will be. | ||||
804 | if (const PHINode *V2PN = dyn_cast<PHINode>(V2)) | ||||
805 | if (V2PN->getParent() == BB) | ||||
806 | V2 = V2PN->getIncomingValueForBlock(Pred); | ||||
807 | |||||
808 | // If there is a conflict, bail out. | ||||
809 | if (V1 != V2) return false; | ||||
810 | } | ||||
811 | } | ||||
812 | } | ||||
813 | |||||
814 | return true; | ||||
815 | } | ||||
816 | |||||
817 | /// Eliminate a basic block that has only phi's and an unconditional branch in | ||||
818 | /// it. | ||||
819 | void CodeGenPrepare::eliminateMostlyEmptyBlock(BasicBlock *BB) { | ||||
820 | BranchInst *BI = cast<BranchInst>(BB->getTerminator()); | ||||
821 | BasicBlock *DestBB = BI->getSuccessor(0); | ||||
822 | |||||
823 | LLVM_DEBUG(dbgs() << "MERGING MOSTLY EMPTY BLOCKS - BEFORE:\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "MERGING MOSTLY EMPTY BLOCKS - BEFORE:\n" << *BB << *DestBB; } } while (false) | ||||
824 | << *BB << *DestBB)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "MERGING MOSTLY EMPTY BLOCKS - BEFORE:\n" << *BB << *DestBB; } } while (false); | ||||
825 | |||||
826 | // If the destination block has a single pred, then this is a trivial edge, | ||||
827 | // just collapse it. | ||||
828 | if (BasicBlock *SinglePred = DestBB->getSinglePredecessor()) { | ||||
829 | if (SinglePred != DestBB) { | ||||
830 | assert(SinglePred == BB &&((SinglePred == BB && "Single predecessor not the same as predecessor" ) ? static_cast<void> (0) : __assert_fail ("SinglePred == BB && \"Single predecessor not the same as predecessor\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 831, __PRETTY_FUNCTION__)) | ||||
831 | "Single predecessor not the same as predecessor")((SinglePred == BB && "Single predecessor not the same as predecessor" ) ? static_cast<void> (0) : __assert_fail ("SinglePred == BB && \"Single predecessor not the same as predecessor\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 831, __PRETTY_FUNCTION__)); | ||||
832 | // Merge DestBB into SinglePred/BB and delete it. | ||||
833 | MergeBlockIntoPredecessor(DestBB); | ||||
834 | // Note: BB(=SinglePred) will not be deleted on this path. | ||||
835 | // DestBB(=its single successor) is the one that was deleted. | ||||
836 | LLVM_DEBUG(dbgs() << "AFTER:\n" << *SinglePred << "\n\n\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "AFTER:\n" << *SinglePred << "\n\n\n"; } } while (false); | ||||
837 | return; | ||||
838 | } | ||||
839 | } | ||||
840 | |||||
841 | // Otherwise, we have multiple predecessors of BB. Update the PHIs in DestBB | ||||
842 | // to handle the new incoming edges it is about to have. | ||||
843 | for (PHINode &PN : DestBB->phis()) { | ||||
844 | // Remove the incoming value for BB, and remember it. | ||||
845 | Value *InVal = PN.removeIncomingValue(BB, false); | ||||
846 | |||||
847 | // Two options: either the InVal is a phi node defined in BB or it is some | ||||
848 | // value that dominates BB. | ||||
849 | PHINode *InValPhi = dyn_cast<PHINode>(InVal); | ||||
850 | if (InValPhi && InValPhi->getParent() == BB) { | ||||
851 | // Add all of the input values of the input PHI as inputs of this phi. | ||||
852 | for (unsigned i = 0, e = InValPhi->getNumIncomingValues(); i != e; ++i) | ||||
853 | PN.addIncoming(InValPhi->getIncomingValue(i), | ||||
854 | InValPhi->getIncomingBlock(i)); | ||||
855 | } else { | ||||
856 | // Otherwise, add one instance of the dominating value for each edge that | ||||
857 | // we will be adding. | ||||
858 | if (PHINode *BBPN = dyn_cast<PHINode>(BB->begin())) { | ||||
859 | for (unsigned i = 0, e = BBPN->getNumIncomingValues(); i != e; ++i) | ||||
860 | PN.addIncoming(InVal, BBPN->getIncomingBlock(i)); | ||||
861 | } else { | ||||
862 | for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) | ||||
863 | PN.addIncoming(InVal, *PI); | ||||
864 | } | ||||
865 | } | ||||
866 | } | ||||
867 | |||||
868 | // The PHIs are now updated, change everything that refers to BB to use | ||||
869 | // DestBB and remove BB. | ||||
870 | BB->replaceAllUsesWith(DestBB); | ||||
871 | BB->eraseFromParent(); | ||||
872 | ++NumBlocksElim; | ||||
873 | |||||
874 | LLVM_DEBUG(dbgs() << "AFTER:\n" << *DestBB << "\n\n\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "AFTER:\n" << *DestBB << "\n\n\n"; } } while (false); | ||||
875 | } | ||||
876 | |||||
877 | // Computes a map of base pointer relocation instructions to corresponding | ||||
878 | // derived pointer relocation instructions given a vector of all relocate calls | ||||
879 | static void computeBaseDerivedRelocateMap( | ||||
880 | const SmallVectorImpl<GCRelocateInst *> &AllRelocateCalls, | ||||
881 | DenseMap<GCRelocateInst *, SmallVector<GCRelocateInst *, 2>> | ||||
882 | &RelocateInstMap) { | ||||
883 | // Collect information in two maps: one primarily for locating the base object | ||||
884 | // while filling the second map; the second map is the final structure holding | ||||
885 | // a mapping between Base and corresponding Derived relocate calls | ||||
886 | DenseMap<std::pair<unsigned, unsigned>, GCRelocateInst *> RelocateIdxMap; | ||||
887 | for (auto *ThisRelocate : AllRelocateCalls) { | ||||
888 | auto K = std::make_pair(ThisRelocate->getBasePtrIndex(), | ||||
889 | ThisRelocate->getDerivedPtrIndex()); | ||||
890 | RelocateIdxMap.insert(std::make_pair(K, ThisRelocate)); | ||||
891 | } | ||||
892 | for (auto &Item : RelocateIdxMap) { | ||||
893 | std::pair<unsigned, unsigned> Key = Item.first; | ||||
894 | if (Key.first == Key.second) | ||||
895 | // Base relocation: nothing to insert | ||||
896 | continue; | ||||
897 | |||||
898 | GCRelocateInst *I = Item.second; | ||||
899 | auto BaseKey = std::make_pair(Key.first, Key.first); | ||||
900 | |||||
901 | // We're iterating over RelocateIdxMap so we cannot modify it. | ||||
902 | auto MaybeBase = RelocateIdxMap.find(BaseKey); | ||||
903 | if (MaybeBase == RelocateIdxMap.end()) | ||||
904 | // TODO: We might want to insert a new base object relocate and gep off | ||||
905 | // that, if there are enough derived object relocates. | ||||
906 | continue; | ||||
907 | |||||
908 | RelocateInstMap[MaybeBase->second].push_back(I); | ||||
909 | } | ||||
910 | } | ||||
911 | |||||
912 | // Accepts a GEP and extracts the operands into a vector provided they're all | ||||
913 | // small integer constants | ||||
914 | static bool getGEPSmallConstantIntOffsetV(GetElementPtrInst *GEP, | ||||
915 | SmallVectorImpl<Value *> &OffsetV) { | ||||
916 | for (unsigned i = 1; i < GEP->getNumOperands(); i++) { | ||||
917 | // Only accept small constant integer operands | ||||
918 | auto Op = dyn_cast<ConstantInt>(GEP->getOperand(i)); | ||||
919 | if (!Op || Op->getZExtValue() > 20) | ||||
920 | return false; | ||||
921 | } | ||||
922 | |||||
923 | for (unsigned i = 1; i < GEP->getNumOperands(); i++) | ||||
924 | OffsetV.push_back(GEP->getOperand(i)); | ||||
925 | return true; | ||||
926 | } | ||||
927 | |||||
928 | // Takes a RelocatedBase (base pointer relocation instruction) and Targets to | ||||
929 | // replace, computes a replacement, and affects it. | ||||
930 | static bool | ||||
931 | simplifyRelocatesOffABase(GCRelocateInst *RelocatedBase, | ||||
932 | const SmallVectorImpl<GCRelocateInst *> &Targets) { | ||||
933 | bool MadeChange = false; | ||||
934 | // We must ensure the relocation of derived pointer is defined after | ||||
935 | // relocation of base pointer. If we find a relocation corresponding to base | ||||
936 | // defined earlier than relocation of base then we move relocation of base | ||||
937 | // right before found relocation. We consider only relocation in the same | ||||
938 | // basic block as relocation of base. Relocations from other basic block will | ||||
939 | // be skipped by optimization and we do not care about them. | ||||
940 | for (auto R = RelocatedBase->getParent()->getFirstInsertionPt(); | ||||
941 | &*R != RelocatedBase; ++R) | ||||
942 | if (auto RI = dyn_cast<GCRelocateInst>(R)) | ||||
943 | if (RI->getStatepoint() == RelocatedBase->getStatepoint()) | ||||
944 | if (RI->getBasePtrIndex() == RelocatedBase->getBasePtrIndex()) { | ||||
945 | RelocatedBase->moveBefore(RI); | ||||
946 | break; | ||||
947 | } | ||||
948 | |||||
949 | for (GCRelocateInst *ToReplace : Targets) { | ||||
950 | assert(ToReplace->getBasePtrIndex() == RelocatedBase->getBasePtrIndex() &&((ToReplace->getBasePtrIndex() == RelocatedBase->getBasePtrIndex () && "Not relocating a derived object of the original base object" ) ? static_cast<void> (0) : __assert_fail ("ToReplace->getBasePtrIndex() == RelocatedBase->getBasePtrIndex() && \"Not relocating a derived object of the original base object\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 951, __PRETTY_FUNCTION__)) | ||||
951 | "Not relocating a derived object of the original base object")((ToReplace->getBasePtrIndex() == RelocatedBase->getBasePtrIndex () && "Not relocating a derived object of the original base object" ) ? static_cast<void> (0) : __assert_fail ("ToReplace->getBasePtrIndex() == RelocatedBase->getBasePtrIndex() && \"Not relocating a derived object of the original base object\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 951, __PRETTY_FUNCTION__)); | ||||
952 | if (ToReplace->getBasePtrIndex() == ToReplace->getDerivedPtrIndex()) { | ||||
953 | // A duplicate relocate call. TODO: coalesce duplicates. | ||||
954 | continue; | ||||
955 | } | ||||
956 | |||||
957 | if (RelocatedBase->getParent() != ToReplace->getParent()) { | ||||
958 | // Base and derived relocates are in different basic blocks. | ||||
959 | // In this case transform is only valid when base dominates derived | ||||
960 | // relocate. However it would be too expensive to check dominance | ||||
961 | // for each such relocate, so we skip the whole transformation. | ||||
962 | continue; | ||||
963 | } | ||||
964 | |||||
965 | Value *Base = ToReplace->getBasePtr(); | ||||
966 | auto Derived = dyn_cast<GetElementPtrInst>(ToReplace->getDerivedPtr()); | ||||
967 | if (!Derived || Derived->getPointerOperand() != Base) | ||||
968 | continue; | ||||
969 | |||||
970 | SmallVector<Value *, 2> OffsetV; | ||||
971 | if (!getGEPSmallConstantIntOffsetV(Derived, OffsetV)) | ||||
972 | continue; | ||||
973 | |||||
974 | // Create a Builder and replace the target callsite with a gep | ||||
975 | assert(RelocatedBase->getNextNode() &&((RelocatedBase->getNextNode() && "Should always have one since it's not a terminator" ) ? static_cast<void> (0) : __assert_fail ("RelocatedBase->getNextNode() && \"Should always have one since it's not a terminator\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 976, __PRETTY_FUNCTION__)) | ||||
976 | "Should always have one since it's not a terminator")((RelocatedBase->getNextNode() && "Should always have one since it's not a terminator" ) ? static_cast<void> (0) : __assert_fail ("RelocatedBase->getNextNode() && \"Should always have one since it's not a terminator\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 976, __PRETTY_FUNCTION__)); | ||||
977 | |||||
978 | // Insert after RelocatedBase | ||||
979 | IRBuilder<> Builder(RelocatedBase->getNextNode()); | ||||
980 | Builder.SetCurrentDebugLocation(ToReplace->getDebugLoc()); | ||||
981 | |||||
982 | // If gc_relocate does not match the actual type, cast it to the right type. | ||||
983 | // In theory, there must be a bitcast after gc_relocate if the type does not | ||||
984 | // match, and we should reuse it to get the derived pointer. But it could be | ||||
985 | // cases like this: | ||||
986 | // bb1: | ||||
987 | // ... | ||||
988 | // %g1 = call coldcc i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(...) | ||||
989 | // br label %merge | ||||
990 | // | ||||
991 | // bb2: | ||||
992 | // ... | ||||
993 | // %g2 = call coldcc i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(...) | ||||
994 | // br label %merge | ||||
995 | // | ||||
996 | // merge: | ||||
997 | // %p1 = phi i8 addrspace(1)* [ %g1, %bb1 ], [ %g2, %bb2 ] | ||||
998 | // %cast = bitcast i8 addrspace(1)* %p1 in to i32 addrspace(1)* | ||||
999 | // | ||||
1000 | // In this case, we can not find the bitcast any more. So we insert a new bitcast | ||||
1001 | // no matter there is already one or not. In this way, we can handle all cases, and | ||||
1002 | // the extra bitcast should be optimized away in later passes. | ||||
1003 | Value *ActualRelocatedBase = RelocatedBase; | ||||
1004 | if (RelocatedBase->getType() != Base->getType()) { | ||||
1005 | ActualRelocatedBase = | ||||
1006 | Builder.CreateBitCast(RelocatedBase, Base->getType()); | ||||
1007 | } | ||||
1008 | Value *Replacement = Builder.CreateGEP( | ||||
1009 | Derived->getSourceElementType(), ActualRelocatedBase, makeArrayRef(OffsetV)); | ||||
1010 | Replacement->takeName(ToReplace); | ||||
1011 | // If the newly generated derived pointer's type does not match the original derived | ||||
1012 | // pointer's type, cast the new derived pointer to match it. Same reasoning as above. | ||||
1013 | Value *ActualReplacement = Replacement; | ||||
1014 | if (Replacement->getType() != ToReplace->getType()) { | ||||
1015 | ActualReplacement = | ||||
1016 | Builder.CreateBitCast(Replacement, ToReplace->getType()); | ||||
1017 | } | ||||
1018 | ToReplace->replaceAllUsesWith(ActualReplacement); | ||||
1019 | ToReplace->eraseFromParent(); | ||||
1020 | |||||
1021 | MadeChange = true; | ||||
1022 | } | ||||
1023 | return MadeChange; | ||||
1024 | } | ||||
1025 | |||||
1026 | // Turns this: | ||||
1027 | // | ||||
1028 | // %base = ... | ||||
1029 | // %ptr = gep %base + 15 | ||||
1030 | // %tok = statepoint (%fun, i32 0, i32 0, i32 0, %base, %ptr) | ||||
1031 | // %base' = relocate(%tok, i32 4, i32 4) | ||||
1032 | // %ptr' = relocate(%tok, i32 4, i32 5) | ||||
1033 | // %val = load %ptr' | ||||
1034 | // | ||||
1035 | // into this: | ||||
1036 | // | ||||
1037 | // %base = ... | ||||
1038 | // %ptr = gep %base + 15 | ||||
1039 | // %tok = statepoint (%fun, i32 0, i32 0, i32 0, %base, %ptr) | ||||
1040 | // %base' = gc.relocate(%tok, i32 4, i32 4) | ||||
1041 | // %ptr' = gep %base' + 15 | ||||
1042 | // %val = load %ptr' | ||||
1043 | bool CodeGenPrepare::simplifyOffsetableRelocate(Instruction &I) { | ||||
1044 | bool MadeChange = false; | ||||
1045 | SmallVector<GCRelocateInst *, 2> AllRelocateCalls; | ||||
1046 | |||||
1047 | for (auto *U : I.users()) | ||||
1048 | if (GCRelocateInst *Relocate = dyn_cast<GCRelocateInst>(U)) | ||||
1049 | // Collect all the relocate calls associated with a statepoint | ||||
1050 | AllRelocateCalls.push_back(Relocate); | ||||
1051 | |||||
1052 | // We need atleast one base pointer relocation + one derived pointer | ||||
1053 | // relocation to mangle | ||||
1054 | if (AllRelocateCalls.size() < 2) | ||||
1055 | return false; | ||||
1056 | |||||
1057 | // RelocateInstMap is a mapping from the base relocate instruction to the | ||||
1058 | // corresponding derived relocate instructions | ||||
1059 | DenseMap<GCRelocateInst *, SmallVector<GCRelocateInst *, 2>> RelocateInstMap; | ||||
1060 | computeBaseDerivedRelocateMap(AllRelocateCalls, RelocateInstMap); | ||||
1061 | if (RelocateInstMap.empty()) | ||||
1062 | return false; | ||||
1063 | |||||
1064 | for (auto &Item : RelocateInstMap) | ||||
1065 | // Item.first is the RelocatedBase to offset against | ||||
1066 | // Item.second is the vector of Targets to replace | ||||
1067 | MadeChange = simplifyRelocatesOffABase(Item.first, Item.second); | ||||
1068 | return MadeChange; | ||||
1069 | } | ||||
1070 | |||||
1071 | /// Sink the specified cast instruction into its user blocks. | ||||
1072 | static bool SinkCast(CastInst *CI) { | ||||
1073 | BasicBlock *DefBB = CI->getParent(); | ||||
1074 | |||||
1075 | /// InsertedCasts - Only insert a cast in each block once. | ||||
1076 | DenseMap<BasicBlock*, CastInst*> InsertedCasts; | ||||
1077 | |||||
1078 | bool MadeChange = false; | ||||
1079 | for (Value::user_iterator UI = CI->user_begin(), E = CI->user_end(); | ||||
1080 | UI != E; ) { | ||||
1081 | Use &TheUse = UI.getUse(); | ||||
1082 | Instruction *User = cast<Instruction>(*UI); | ||||
1083 | |||||
1084 | // Figure out which BB this cast is used in. For PHI's this is the | ||||
1085 | // appropriate predecessor block. | ||||
1086 | BasicBlock *UserBB = User->getParent(); | ||||
1087 | if (PHINode *PN = dyn_cast<PHINode>(User)) { | ||||
1088 | UserBB = PN->getIncomingBlock(TheUse); | ||||
1089 | } | ||||
1090 | |||||
1091 | // Preincrement use iterator so we don't invalidate it. | ||||
1092 | ++UI; | ||||
1093 | |||||
1094 | // The first insertion point of a block containing an EH pad is after the | ||||
1095 | // pad. If the pad is the user, we cannot sink the cast past the pad. | ||||
1096 | if (User->isEHPad()) | ||||
1097 | continue; | ||||
1098 | |||||
1099 | // If the block selected to receive the cast is an EH pad that does not | ||||
1100 | // allow non-PHI instructions before the terminator, we can't sink the | ||||
1101 | // cast. | ||||
1102 | if (UserBB->getTerminator()->isEHPad()) | ||||
1103 | continue; | ||||
1104 | |||||
1105 | // If this user is in the same block as the cast, don't change the cast. | ||||
1106 | if (UserBB == DefBB) continue; | ||||
1107 | |||||
1108 | // If we have already inserted a cast into this block, use it. | ||||
1109 | CastInst *&InsertedCast = InsertedCasts[UserBB]; | ||||
1110 | |||||
1111 | if (!InsertedCast) { | ||||
1112 | BasicBlock::iterator InsertPt = UserBB->getFirstInsertionPt(); | ||||
1113 | assert(InsertPt != UserBB->end())((InsertPt != UserBB->end()) ? static_cast<void> (0) : __assert_fail ("InsertPt != UserBB->end()", "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 1113, __PRETTY_FUNCTION__)); | ||||
1114 | InsertedCast = CastInst::Create(CI->getOpcode(), CI->getOperand(0), | ||||
1115 | CI->getType(), "", &*InsertPt); | ||||
1116 | InsertedCast->setDebugLoc(CI->getDebugLoc()); | ||||
1117 | } | ||||
1118 | |||||
1119 | // Replace a use of the cast with a use of the new cast. | ||||
1120 | TheUse = InsertedCast; | ||||
1121 | MadeChange = true; | ||||
1122 | ++NumCastUses; | ||||
1123 | } | ||||
1124 | |||||
1125 | // If we removed all uses, nuke the cast. | ||||
1126 | if (CI->use_empty()) { | ||||
1127 | salvageDebugInfo(*CI); | ||||
1128 | CI->eraseFromParent(); | ||||
1129 | MadeChange = true; | ||||
1130 | } | ||||
1131 | |||||
1132 | return MadeChange; | ||||
1133 | } | ||||
1134 | |||||
1135 | /// If the specified cast instruction is a noop copy (e.g. it's casting from | ||||
1136 | /// one pointer type to another, i32->i8 on PPC), sink it into user blocks to | ||||
1137 | /// reduce the number of virtual registers that must be created and coalesced. | ||||
1138 | /// | ||||
1139 | /// Return true if any changes are made. | ||||
1140 | static bool OptimizeNoopCopyExpression(CastInst *CI, const TargetLowering &TLI, | ||||
1141 | const DataLayout &DL) { | ||||
1142 | // Sink only "cheap" (or nop) address-space casts. This is a weaker condition | ||||
1143 | // than sinking only nop casts, but is helpful on some platforms. | ||||
1144 | if (auto *ASC = dyn_cast<AddrSpaceCastInst>(CI)) { | ||||
1145 | if (!TLI.isFreeAddrSpaceCast(ASC->getSrcAddressSpace(), | ||||
1146 | ASC->getDestAddressSpace())) | ||||
1147 | return false; | ||||
1148 | } | ||||
1149 | |||||
1150 | // If this is a noop copy, | ||||
1151 | EVT SrcVT = TLI.getValueType(DL, CI->getOperand(0)->getType()); | ||||
1152 | EVT DstVT = TLI.getValueType(DL, CI->getType()); | ||||
1153 | |||||
1154 | // This is an fp<->int conversion? | ||||
1155 | if (SrcVT.isInteger() != DstVT.isInteger()) | ||||
1156 | return false; | ||||
1157 | |||||
1158 | // If this is an extension, it will be a zero or sign extension, which | ||||
1159 | // isn't a noop. | ||||
1160 | if (SrcVT.bitsLT(DstVT)) return false; | ||||
1161 | |||||
1162 | // If these values will be promoted, find out what they will be promoted | ||||
1163 | // to. This helps us consider truncates on PPC as noop copies when they | ||||
1164 | // are. | ||||
1165 | if (TLI.getTypeAction(CI->getContext(), SrcVT) == | ||||
1166 | TargetLowering::TypePromoteInteger) | ||||
1167 | SrcVT = TLI.getTypeToTransformTo(CI->getContext(), SrcVT); | ||||
1168 | if (TLI.getTypeAction(CI->getContext(), DstVT) == | ||||
1169 | TargetLowering::TypePromoteInteger) | ||||
1170 | DstVT = TLI.getTypeToTransformTo(CI->getContext(), DstVT); | ||||
1171 | |||||
1172 | // If, after promotion, these are the same types, this is a noop copy. | ||||
1173 | if (SrcVT != DstVT) | ||||
1174 | return false; | ||||
1175 | |||||
1176 | return SinkCast(CI); | ||||
1177 | } | ||||
1178 | |||||
1179 | bool CodeGenPrepare::replaceMathCmpWithIntrinsic(BinaryOperator *BO, | ||||
1180 | CmpInst *Cmp, | ||||
1181 | Intrinsic::ID IID) { | ||||
1182 | if (BO->getParent() != Cmp->getParent()) { | ||||
1183 | // We used to use a dominator tree here to allow multi-block optimization. | ||||
1184 | // But that was problematic because: | ||||
1185 | // 1. It could cause a perf regression by hoisting the math op into the | ||||
1186 | // critical path. | ||||
1187 | // 2. It could cause a perf regression by creating a value that was live | ||||
1188 | // across multiple blocks and increasing register pressure. | ||||
1189 | // 3. Use of a dominator tree could cause large compile-time regression. | ||||
1190 | // This is because we recompute the DT on every change in the main CGP | ||||
1191 | // run-loop. The recomputing is probably unnecessary in many cases, so if | ||||
1192 | // that was fixed, using a DT here would be ok. | ||||
1193 | return false; | ||||
1194 | } | ||||
1195 | |||||
1196 | // We allow matching the canonical IR (add X, C) back to (usubo X, -C). | ||||
1197 | Value *Arg0 = BO->getOperand(0); | ||||
1198 | Value *Arg1 = BO->getOperand(1); | ||||
1199 | if (BO->getOpcode() == Instruction::Add && | ||||
1200 | IID == Intrinsic::usub_with_overflow) { | ||||
1201 | assert(isa<Constant>(Arg1) && "Unexpected input for usubo")((isa<Constant>(Arg1) && "Unexpected input for usubo" ) ? static_cast<void> (0) : __assert_fail ("isa<Constant>(Arg1) && \"Unexpected input for usubo\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 1201, __PRETTY_FUNCTION__)); | ||||
1202 | Arg1 = ConstantExpr::getNeg(cast<Constant>(Arg1)); | ||||
1203 | } | ||||
1204 | |||||
1205 | // Insert at the first instruction of the pair. | ||||
1206 | Instruction *InsertPt = nullptr; | ||||
1207 | for (Instruction &Iter : *Cmp->getParent()) { | ||||
1208 | if (&Iter == BO || &Iter == Cmp) { | ||||
1209 | InsertPt = &Iter; | ||||
1210 | break; | ||||
1211 | } | ||||
1212 | } | ||||
1213 | assert(InsertPt != nullptr && "Parent block did not contain cmp or binop")((InsertPt != nullptr && "Parent block did not contain cmp or binop" ) ? static_cast<void> (0) : __assert_fail ("InsertPt != nullptr && \"Parent block did not contain cmp or binop\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 1213, __PRETTY_FUNCTION__)); | ||||
1214 | |||||
1215 | IRBuilder<> Builder(InsertPt); | ||||
1216 | Value *MathOV = Builder.CreateBinaryIntrinsic(IID, Arg0, Arg1); | ||||
1217 | Value *Math = Builder.CreateExtractValue(MathOV, 0, "math"); | ||||
1218 | Value *OV = Builder.CreateExtractValue(MathOV, 1, "ov"); | ||||
1219 | BO->replaceAllUsesWith(Math); | ||||
1220 | Cmp->replaceAllUsesWith(OV); | ||||
1221 | BO->eraseFromParent(); | ||||
1222 | Cmp->eraseFromParent(); | ||||
1223 | return true; | ||||
1224 | } | ||||
1225 | |||||
1226 | /// Match special-case patterns that check for unsigned add overflow. | ||||
1227 | static bool matchUAddWithOverflowConstantEdgeCases(CmpInst *Cmp, | ||||
1228 | BinaryOperator *&Add) { | ||||
1229 | // Add = add A, 1; Cmp = icmp eq A,-1 (overflow if A is max val) | ||||
1230 | // Add = add A,-1; Cmp = icmp ne A, 0 (overflow if A is non-zero) | ||||
1231 | Value *A = Cmp->getOperand(0), *B = Cmp->getOperand(1); | ||||
1232 | |||||
1233 | // We are not expecting non-canonical/degenerate code. Just bail out. | ||||
1234 | if (isa<Constant>(A)) | ||||
1235 | return false; | ||||
1236 | |||||
1237 | ICmpInst::Predicate Pred = Cmp->getPredicate(); | ||||
1238 | if (Pred == ICmpInst::ICMP_EQ && match(B, m_AllOnes())) | ||||
1239 | B = ConstantInt::get(B->getType(), 1); | ||||
1240 | else if (Pred == ICmpInst::ICMP_NE && match(B, m_ZeroInt())) | ||||
1241 | B = ConstantInt::get(B->getType(), -1); | ||||
1242 | else | ||||
1243 | return false; | ||||
1244 | |||||
1245 | // Check the users of the variable operand of the compare looking for an add | ||||
1246 | // with the adjusted constant. | ||||
1247 | for (User *U : A->users()) { | ||||
1248 | if (match(U, m_Add(m_Specific(A), m_Specific(B)))) { | ||||
1249 | Add = cast<BinaryOperator>(U); | ||||
1250 | return true; | ||||
1251 | } | ||||
1252 | } | ||||
1253 | return false; | ||||
1254 | } | ||||
1255 | |||||
1256 | /// Try to combine the compare into a call to the llvm.uadd.with.overflow | ||||
1257 | /// intrinsic. Return true if any changes were made. | ||||
1258 | bool CodeGenPrepare::combineToUAddWithOverflow(CmpInst *Cmp, | ||||
1259 | bool &ModifiedDT) { | ||||
1260 | Value *A, *B; | ||||
1261 | BinaryOperator *Add; | ||||
1262 | if (!match(Cmp, m_UAddWithOverflow(m_Value(A), m_Value(B), m_BinOp(Add)))) | ||||
1263 | if (!matchUAddWithOverflowConstantEdgeCases(Cmp, Add)) | ||||
1264 | return false; | ||||
1265 | |||||
1266 | if (!TLI->shouldFormOverflowOp(ISD::UADDO, | ||||
1267 | TLI->getValueType(*DL, Add->getType()))) | ||||
1268 | return false; | ||||
1269 | |||||
1270 | // We don't want to move around uses of condition values this late, so we | ||||
1271 | // check if it is legal to create the call to the intrinsic in the basic | ||||
1272 | // block containing the icmp. | ||||
1273 | if (Add->getParent() != Cmp->getParent() && !Add->hasOneUse()) | ||||
1274 | return false; | ||||
1275 | |||||
1276 | if (!replaceMathCmpWithIntrinsic(Add, Cmp, Intrinsic::uadd_with_overflow)) | ||||
1277 | return false; | ||||
1278 | |||||
1279 | // Reset callers - do not crash by iterating over a dead instruction. | ||||
1280 | ModifiedDT = true; | ||||
1281 | return true; | ||||
1282 | } | ||||
1283 | |||||
1284 | bool CodeGenPrepare::combineToUSubWithOverflow(CmpInst *Cmp, | ||||
1285 | bool &ModifiedDT) { | ||||
1286 | // We are not expecting non-canonical/degenerate code. Just bail out. | ||||
1287 | Value *A = Cmp->getOperand(0), *B = Cmp->getOperand(1); | ||||
1288 | if (isa<Constant>(A) && isa<Constant>(B)) | ||||
1289 | return false; | ||||
1290 | |||||
1291 | // Convert (A u> B) to (A u< B) to simplify pattern matching. | ||||
1292 | ICmpInst::Predicate Pred = Cmp->getPredicate(); | ||||
1293 | if (Pred == ICmpInst::ICMP_UGT) { | ||||
1294 | std::swap(A, B); | ||||
1295 | Pred = ICmpInst::ICMP_ULT; | ||||
1296 | } | ||||
1297 | // Convert special-case: (A == 0) is the same as (A u< 1). | ||||
1298 | if (Pred == ICmpInst::ICMP_EQ && match(B, m_ZeroInt())) { | ||||
1299 | B = ConstantInt::get(B->getType(), 1); | ||||
1300 | Pred = ICmpInst::ICMP_ULT; | ||||
1301 | } | ||||
1302 | // Convert special-case: (A != 0) is the same as (0 u< A). | ||||
1303 | if (Pred == ICmpInst::ICMP_NE && match(B, m_ZeroInt())) { | ||||
1304 | std::swap(A, B); | ||||
1305 | Pred = ICmpInst::ICMP_ULT; | ||||
1306 | } | ||||
1307 | if (Pred != ICmpInst::ICMP_ULT) | ||||
1308 | return false; | ||||
1309 | |||||
1310 | // Walk the users of a variable operand of a compare looking for a subtract or | ||||
1311 | // add with that same operand. Also match the 2nd operand of the compare to | ||||
1312 | // the add/sub, but that may be a negated constant operand of an add. | ||||
1313 | Value *CmpVariableOperand = isa<Constant>(A) ? B : A; | ||||
1314 | BinaryOperator *Sub = nullptr; | ||||
1315 | for (User *U : CmpVariableOperand->users()) { | ||||
1316 | // A - B, A u< B --> usubo(A, B) | ||||
1317 | if (match(U, m_Sub(m_Specific(A), m_Specific(B)))) { | ||||
1318 | Sub = cast<BinaryOperator>(U); | ||||
1319 | break; | ||||
1320 | } | ||||
1321 | |||||
1322 | // A + (-C), A u< C (canonicalized form of (sub A, C)) | ||||
1323 | const APInt *CmpC, *AddC; | ||||
1324 | if (match(U, m_Add(m_Specific(A), m_APInt(AddC))) && | ||||
1325 | match(B, m_APInt(CmpC)) && *AddC == -(*CmpC)) { | ||||
1326 | Sub = cast<BinaryOperator>(U); | ||||
1327 | break; | ||||
1328 | } | ||||
1329 | } | ||||
1330 | if (!Sub) | ||||
1331 | return false; | ||||
1332 | |||||
1333 | if (!TLI->shouldFormOverflowOp(ISD::USUBO, | ||||
1334 | TLI->getValueType(*DL, Sub->getType()))) | ||||
1335 | return false; | ||||
1336 | |||||
1337 | if (!replaceMathCmpWithIntrinsic(Sub, Cmp, Intrinsic::usub_with_overflow)) | ||||
1338 | return false; | ||||
1339 | |||||
1340 | // Reset callers - do not crash by iterating over a dead instruction. | ||||
1341 | ModifiedDT = true; | ||||
1342 | return true; | ||||
1343 | } | ||||
1344 | |||||
1345 | /// Sink the given CmpInst into user blocks to reduce the number of virtual | ||||
1346 | /// registers that must be created and coalesced. This is a clear win except on | ||||
1347 | /// targets with multiple condition code registers (PowerPC), where it might | ||||
1348 | /// lose; some adjustment may be wanted there. | ||||
1349 | /// | ||||
1350 | /// Return true if any changes are made. | ||||
1351 | static bool sinkCmpExpression(CmpInst *Cmp, const TargetLowering &TLI) { | ||||
1352 | if (TLI.hasMultipleConditionRegisters()) | ||||
1353 | return false; | ||||
1354 | |||||
1355 | // Avoid sinking soft-FP comparisons, since this can move them into a loop. | ||||
1356 | if (TLI.useSoftFloat() && isa<FCmpInst>(Cmp)) | ||||
1357 | return false; | ||||
1358 | |||||
1359 | // Only insert a cmp in each block once. | ||||
1360 | DenseMap<BasicBlock*, CmpInst*> InsertedCmps; | ||||
1361 | |||||
1362 | bool MadeChange = false; | ||||
1363 | for (Value::user_iterator UI = Cmp->user_begin(), E = Cmp->user_end(); | ||||
1364 | UI != E; ) { | ||||
1365 | Use &TheUse = UI.getUse(); | ||||
1366 | Instruction *User = cast<Instruction>(*UI); | ||||
1367 | |||||
1368 | // Preincrement use iterator so we don't invalidate it. | ||||
1369 | ++UI; | ||||
1370 | |||||
1371 | // Don't bother for PHI nodes. | ||||
1372 | if (isa<PHINode>(User)) | ||||
1373 | continue; | ||||
1374 | |||||
1375 | // Figure out which BB this cmp is used in. | ||||
1376 | BasicBlock *UserBB = User->getParent(); | ||||
1377 | BasicBlock *DefBB = Cmp->getParent(); | ||||
1378 | |||||
1379 | // If this user is in the same block as the cmp, don't change the cmp. | ||||
1380 | if (UserBB == DefBB) continue; | ||||
1381 | |||||
1382 | // If we have already inserted a cmp into this block, use it. | ||||
1383 | CmpInst *&InsertedCmp = InsertedCmps[UserBB]; | ||||
1384 | |||||
1385 | if (!InsertedCmp) { | ||||
1386 | BasicBlock::iterator InsertPt = UserBB->getFirstInsertionPt(); | ||||
1387 | assert(InsertPt != UserBB->end())((InsertPt != UserBB->end()) ? static_cast<void> (0) : __assert_fail ("InsertPt != UserBB->end()", "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 1387, __PRETTY_FUNCTION__)); | ||||
1388 | InsertedCmp = | ||||
1389 | CmpInst::Create(Cmp->getOpcode(), Cmp->getPredicate(), | ||||
1390 | Cmp->getOperand(0), Cmp->getOperand(1), "", | ||||
1391 | &*InsertPt); | ||||
1392 | // Propagate the debug info. | ||||
1393 | InsertedCmp->setDebugLoc(Cmp->getDebugLoc()); | ||||
1394 | } | ||||
1395 | |||||
1396 | // Replace a use of the cmp with a use of the new cmp. | ||||
1397 | TheUse = InsertedCmp; | ||||
1398 | MadeChange = true; | ||||
1399 | ++NumCmpUses; | ||||
1400 | } | ||||
1401 | |||||
1402 | // If we removed all uses, nuke the cmp. | ||||
1403 | if (Cmp->use_empty()) { | ||||
1404 | Cmp->eraseFromParent(); | ||||
1405 | MadeChange = true; | ||||
1406 | } | ||||
1407 | |||||
1408 | return MadeChange; | ||||
1409 | } | ||||
1410 | |||||
1411 | bool CodeGenPrepare::optimizeCmp(CmpInst *Cmp, bool &ModifiedDT) { | ||||
1412 | if (sinkCmpExpression(Cmp, *TLI)) | ||||
1413 | return true; | ||||
1414 | |||||
1415 | if (combineToUAddWithOverflow(Cmp, ModifiedDT)) | ||||
1416 | return true; | ||||
1417 | |||||
1418 | if (combineToUSubWithOverflow(Cmp, ModifiedDT)) | ||||
1419 | return true; | ||||
1420 | |||||
1421 | return false; | ||||
1422 | } | ||||
1423 | |||||
1424 | /// Duplicate and sink the given 'and' instruction into user blocks where it is | ||||
1425 | /// used in a compare to allow isel to generate better code for targets where | ||||
1426 | /// this operation can be combined. | ||||
1427 | /// | ||||
1428 | /// Return true if any changes are made. | ||||
1429 | static bool sinkAndCmp0Expression(Instruction *AndI, | ||||
1430 | const TargetLowering &TLI, | ||||
1431 | SetOfInstrs &InsertedInsts) { | ||||
1432 | // Double-check that we're not trying to optimize an instruction that was | ||||
1433 | // already optimized by some other part of this pass. | ||||
1434 | assert(!InsertedInsts.count(AndI) &&((!InsertedInsts.count(AndI) && "Attempting to optimize already optimized and instruction" ) ? static_cast<void> (0) : __assert_fail ("!InsertedInsts.count(AndI) && \"Attempting to optimize already optimized and instruction\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 1435, __PRETTY_FUNCTION__)) | ||||
1435 | "Attempting to optimize already optimized and instruction")((!InsertedInsts.count(AndI) && "Attempting to optimize already optimized and instruction" ) ? static_cast<void> (0) : __assert_fail ("!InsertedInsts.count(AndI) && \"Attempting to optimize already optimized and instruction\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 1435, __PRETTY_FUNCTION__)); | ||||
1436 | (void) InsertedInsts; | ||||
1437 | |||||
1438 | // Nothing to do for single use in same basic block. | ||||
1439 | if (AndI->hasOneUse() && | ||||
1440 | AndI->getParent() == cast<Instruction>(*AndI->user_begin())->getParent()) | ||||
1441 | return false; | ||||
1442 | |||||
1443 | // Try to avoid cases where sinking/duplicating is likely to increase register | ||||
1444 | // pressure. | ||||
1445 | if (!isa<ConstantInt>(AndI->getOperand(0)) && | ||||
1446 | !isa<ConstantInt>(AndI->getOperand(1)) && | ||||
1447 | AndI->getOperand(0)->hasOneUse() && AndI->getOperand(1)->hasOneUse()) | ||||
1448 | return false; | ||||
1449 | |||||
1450 | for (auto *U : AndI->users()) { | ||||
1451 | Instruction *User = cast<Instruction>(U); | ||||
1452 | |||||
1453 | // Only sink 'and' feeding icmp with 0. | ||||
1454 | if (!isa<ICmpInst>(User)) | ||||
1455 | return false; | ||||
1456 | |||||
1457 | auto *CmpC = dyn_cast<ConstantInt>(User->getOperand(1)); | ||||
1458 | if (!CmpC || !CmpC->isZero()) | ||||
1459 | return false; | ||||
1460 | } | ||||
1461 | |||||
1462 | if (!TLI.isMaskAndCmp0FoldingBeneficial(*AndI)) | ||||
1463 | return false; | ||||
1464 | |||||
1465 | LLVM_DEBUG(dbgs() << "found 'and' feeding only icmp 0;\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "found 'and' feeding only icmp 0;\n" ; } } while (false); | ||||
1466 | LLVM_DEBUG(AndI->getParent()->dump())do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { AndI->getParent()->dump(); } } while (false); | ||||
1467 | |||||
1468 | // Push the 'and' into the same block as the icmp 0. There should only be | ||||
1469 | // one (icmp (and, 0)) in each block, since CSE/GVN should have removed any | ||||
1470 | // others, so we don't need to keep track of which BBs we insert into. | ||||
1471 | for (Value::user_iterator UI = AndI->user_begin(), E = AndI->user_end(); | ||||
1472 | UI != E; ) { | ||||
1473 | Use &TheUse = UI.getUse(); | ||||
1474 | Instruction *User = cast<Instruction>(*UI); | ||||
1475 | |||||
1476 | // Preincrement use iterator so we don't invalidate it. | ||||
1477 | ++UI; | ||||
1478 | |||||
1479 | LLVM_DEBUG(dbgs() << "sinking 'and' use: " << *User << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "sinking 'and' use: " << *User << "\n"; } } while (false); | ||||
1480 | |||||
1481 | // Keep the 'and' in the same place if the use is already in the same block. | ||||
1482 | Instruction *InsertPt = | ||||
1483 | User->getParent() == AndI->getParent() ? AndI : User; | ||||
1484 | Instruction *InsertedAnd = | ||||
1485 | BinaryOperator::Create(Instruction::And, AndI->getOperand(0), | ||||
1486 | AndI->getOperand(1), "", InsertPt); | ||||
1487 | // Propagate the debug info. | ||||
1488 | InsertedAnd->setDebugLoc(AndI->getDebugLoc()); | ||||
1489 | |||||
1490 | // Replace a use of the 'and' with a use of the new 'and'. | ||||
1491 | TheUse = InsertedAnd; | ||||
1492 | ++NumAndUses; | ||||
1493 | LLVM_DEBUG(User->getParent()->dump())do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { User->getParent()->dump(); } } while (false); | ||||
1494 | } | ||||
1495 | |||||
1496 | // We removed all uses, nuke the and. | ||||
1497 | AndI->eraseFromParent(); | ||||
1498 | return true; | ||||
1499 | } | ||||
1500 | |||||
1501 | /// Check if the candidates could be combined with a shift instruction, which | ||||
1502 | /// includes: | ||||
1503 | /// 1. Truncate instruction | ||||
1504 | /// 2. And instruction and the imm is a mask of the low bits: | ||||
1505 | /// imm & (imm+1) == 0 | ||||
1506 | static bool isExtractBitsCandidateUse(Instruction *User) { | ||||
1507 | if (!isa<TruncInst>(User)) { | ||||
1508 | if (User->getOpcode() != Instruction::And || | ||||
1509 | !isa<ConstantInt>(User->getOperand(1))) | ||||
1510 | return false; | ||||
1511 | |||||
1512 | const APInt &Cimm = cast<ConstantInt>(User->getOperand(1))->getValue(); | ||||
1513 | |||||
1514 | if ((Cimm & (Cimm + 1)).getBoolValue()) | ||||
1515 | return false; | ||||
1516 | } | ||||
1517 | return true; | ||||
1518 | } | ||||
1519 | |||||
1520 | /// Sink both shift and truncate instruction to the use of truncate's BB. | ||||
1521 | static bool | ||||
1522 | SinkShiftAndTruncate(BinaryOperator *ShiftI, Instruction *User, ConstantInt *CI, | ||||
1523 | DenseMap<BasicBlock *, BinaryOperator *> &InsertedShifts, | ||||
1524 | const TargetLowering &TLI, const DataLayout &DL) { | ||||
1525 | BasicBlock *UserBB = User->getParent(); | ||||
1526 | DenseMap<BasicBlock *, CastInst *> InsertedTruncs; | ||||
1527 | TruncInst *TruncI = dyn_cast<TruncInst>(User); | ||||
1528 | bool MadeChange = false; | ||||
1529 | |||||
1530 | for (Value::user_iterator TruncUI = TruncI->user_begin(), | ||||
1531 | TruncE = TruncI->user_end(); | ||||
1532 | TruncUI != TruncE;) { | ||||
1533 | |||||
1534 | Use &TruncTheUse = TruncUI.getUse(); | ||||
1535 | Instruction *TruncUser = cast<Instruction>(*TruncUI); | ||||
1536 | // Preincrement use iterator so we don't invalidate it. | ||||
1537 | |||||
1538 | ++TruncUI; | ||||
1539 | |||||
1540 | int ISDOpcode = TLI.InstructionOpcodeToISD(TruncUser->getOpcode()); | ||||
1541 | if (!ISDOpcode) | ||||
1542 | continue; | ||||
1543 | |||||
1544 | // If the use is actually a legal node, there will not be an | ||||
1545 | // implicit truncate. | ||||
1546 | // FIXME: always querying the result type is just an | ||||
1547 | // approximation; some nodes' legality is determined by the | ||||
1548 | // operand or other means. There's no good way to find out though. | ||||
1549 | if (TLI.isOperationLegalOrCustom( | ||||
1550 | ISDOpcode, TLI.getValueType(DL, TruncUser->getType(), true))) | ||||
1551 | continue; | ||||
1552 | |||||
1553 | // Don't bother for PHI nodes. | ||||
1554 | if (isa<PHINode>(TruncUser)) | ||||
1555 | continue; | ||||
1556 | |||||
1557 | BasicBlock *TruncUserBB = TruncUser->getParent(); | ||||
1558 | |||||
1559 | if (UserBB == TruncUserBB) | ||||
1560 | continue; | ||||
1561 | |||||
1562 | BinaryOperator *&InsertedShift = InsertedShifts[TruncUserBB]; | ||||
1563 | CastInst *&InsertedTrunc = InsertedTruncs[TruncUserBB]; | ||||
1564 | |||||
1565 | if (!InsertedShift && !InsertedTrunc) { | ||||
1566 | BasicBlock::iterator InsertPt = TruncUserBB->getFirstInsertionPt(); | ||||
1567 | assert(InsertPt != TruncUserBB->end())((InsertPt != TruncUserBB->end()) ? static_cast<void> (0) : __assert_fail ("InsertPt != TruncUserBB->end()", "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 1567, __PRETTY_FUNCTION__)); | ||||
1568 | // Sink the shift | ||||
1569 | if (ShiftI->getOpcode() == Instruction::AShr) | ||||
1570 | InsertedShift = BinaryOperator::CreateAShr(ShiftI->getOperand(0), CI, | ||||
1571 | "", &*InsertPt); | ||||
1572 | else | ||||
1573 | InsertedShift = BinaryOperator::CreateLShr(ShiftI->getOperand(0), CI, | ||||
1574 | "", &*InsertPt); | ||||
1575 | InsertedShift->setDebugLoc(ShiftI->getDebugLoc()); | ||||
1576 | |||||
1577 | // Sink the trunc | ||||
1578 | BasicBlock::iterator TruncInsertPt = TruncUserBB->getFirstInsertionPt(); | ||||
1579 | TruncInsertPt++; | ||||
1580 | assert(TruncInsertPt != TruncUserBB->end())((TruncInsertPt != TruncUserBB->end()) ? static_cast<void > (0) : __assert_fail ("TruncInsertPt != TruncUserBB->end()" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 1580, __PRETTY_FUNCTION__)); | ||||
1581 | |||||
1582 | InsertedTrunc = CastInst::Create(TruncI->getOpcode(), InsertedShift, | ||||
1583 | TruncI->getType(), "", &*TruncInsertPt); | ||||
1584 | InsertedTrunc->setDebugLoc(TruncI->getDebugLoc()); | ||||
1585 | |||||
1586 | MadeChange = true; | ||||
1587 | |||||
1588 | TruncTheUse = InsertedTrunc; | ||||
1589 | } | ||||
1590 | } | ||||
1591 | return MadeChange; | ||||
1592 | } | ||||
1593 | |||||
1594 | /// Sink the shift *right* instruction into user blocks if the uses could | ||||
1595 | /// potentially be combined with this shift instruction and generate BitExtract | ||||
1596 | /// instruction. It will only be applied if the architecture supports BitExtract | ||||
1597 | /// instruction. Here is an example: | ||||
1598 | /// BB1: | ||||
1599 | /// %x.extract.shift = lshr i64 %arg1, 32 | ||||
1600 | /// BB2: | ||||
1601 | /// %x.extract.trunc = trunc i64 %x.extract.shift to i16 | ||||
1602 | /// ==> | ||||
1603 | /// | ||||
1604 | /// BB2: | ||||
1605 | /// %x.extract.shift.1 = lshr i64 %arg1, 32 | ||||
1606 | /// %x.extract.trunc = trunc i64 %x.extract.shift.1 to i16 | ||||
1607 | /// | ||||
1608 | /// CodeGen will recognize the pattern in BB2 and generate BitExtract | ||||
1609 | /// instruction. | ||||
1610 | /// Return true if any changes are made. | ||||
1611 | static bool OptimizeExtractBits(BinaryOperator *ShiftI, ConstantInt *CI, | ||||
1612 | const TargetLowering &TLI, | ||||
1613 | const DataLayout &DL) { | ||||
1614 | BasicBlock *DefBB = ShiftI->getParent(); | ||||
1615 | |||||
1616 | /// Only insert instructions in each block once. | ||||
1617 | DenseMap<BasicBlock *, BinaryOperator *> InsertedShifts; | ||||
1618 | |||||
1619 | bool shiftIsLegal = TLI.isTypeLegal(TLI.getValueType(DL, ShiftI->getType())); | ||||
1620 | |||||
1621 | bool MadeChange = false; | ||||
1622 | for (Value::user_iterator UI = ShiftI->user_begin(), E = ShiftI->user_end(); | ||||
1623 | UI != E;) { | ||||
1624 | Use &TheUse = UI.getUse(); | ||||
1625 | Instruction *User = cast<Instruction>(*UI); | ||||
1626 | // Preincrement use iterator so we don't invalidate it. | ||||
1627 | ++UI; | ||||
1628 | |||||
1629 | // Don't bother for PHI nodes. | ||||
1630 | if (isa<PHINode>(User)) | ||||
1631 | continue; | ||||
1632 | |||||
1633 | if (!isExtractBitsCandidateUse(User)) | ||||
1634 | continue; | ||||
1635 | |||||
1636 | BasicBlock *UserBB = User->getParent(); | ||||
1637 | |||||
1638 | if (UserBB == DefBB) { | ||||
1639 | // If the shift and truncate instruction are in the same BB. The use of | ||||
1640 | // the truncate(TruncUse) may still introduce another truncate if not | ||||
1641 | // legal. In this case, we would like to sink both shift and truncate | ||||
1642 | // instruction to the BB of TruncUse. | ||||
1643 | // for example: | ||||
1644 | // BB1: | ||||
1645 | // i64 shift.result = lshr i64 opnd, imm | ||||
1646 | // trunc.result = trunc shift.result to i16 | ||||
1647 | // | ||||
1648 | // BB2: | ||||
1649 | // ----> We will have an implicit truncate here if the architecture does | ||||
1650 | // not have i16 compare. | ||||
1651 | // cmp i16 trunc.result, opnd2 | ||||
1652 | // | ||||
1653 | if (isa<TruncInst>(User) && shiftIsLegal | ||||
1654 | // If the type of the truncate is legal, no truncate will be | ||||
1655 | // introduced in other basic blocks. | ||||
1656 | && | ||||
1657 | (!TLI.isTypeLegal(TLI.getValueType(DL, User->getType())))) | ||||
1658 | MadeChange = | ||||
1659 | SinkShiftAndTruncate(ShiftI, User, CI, InsertedShifts, TLI, DL); | ||||
1660 | |||||
1661 | continue; | ||||
1662 | } | ||||
1663 | // If we have already inserted a shift into this block, use it. | ||||
1664 | BinaryOperator *&InsertedShift = InsertedShifts[UserBB]; | ||||
1665 | |||||
1666 | if (!InsertedShift) { | ||||
1667 | BasicBlock::iterator InsertPt = UserBB->getFirstInsertionPt(); | ||||
1668 | assert(InsertPt != UserBB->end())((InsertPt != UserBB->end()) ? static_cast<void> (0) : __assert_fail ("InsertPt != UserBB->end()", "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 1668, __PRETTY_FUNCTION__)); | ||||
1669 | |||||
1670 | if (ShiftI->getOpcode() == Instruction::AShr) | ||||
1671 | InsertedShift = BinaryOperator::CreateAShr(ShiftI->getOperand(0), CI, | ||||
1672 | "", &*InsertPt); | ||||
1673 | else | ||||
1674 | InsertedShift = BinaryOperator::CreateLShr(ShiftI->getOperand(0), CI, | ||||
1675 | "", &*InsertPt); | ||||
1676 | InsertedShift->setDebugLoc(ShiftI->getDebugLoc()); | ||||
1677 | |||||
1678 | MadeChange = true; | ||||
1679 | } | ||||
1680 | |||||
1681 | // Replace a use of the shift with a use of the new shift. | ||||
1682 | TheUse = InsertedShift; | ||||
1683 | } | ||||
1684 | |||||
1685 | // If we removed all uses, or there are none, nuke the shift. | ||||
1686 | if (ShiftI->use_empty()) { | ||||
1687 | salvageDebugInfo(*ShiftI); | ||||
1688 | ShiftI->eraseFromParent(); | ||||
1689 | MadeChange = true; | ||||
1690 | } | ||||
1691 | |||||
1692 | return MadeChange; | ||||
1693 | } | ||||
1694 | |||||
1695 | /// If counting leading or trailing zeros is an expensive operation and a zero | ||||
1696 | /// input is defined, add a check for zero to avoid calling the intrinsic. | ||||
1697 | /// | ||||
1698 | /// We want to transform: | ||||
1699 | /// %z = call i64 @llvm.cttz.i64(i64 %A, i1 false) | ||||
1700 | /// | ||||
1701 | /// into: | ||||
1702 | /// entry: | ||||
1703 | /// %cmpz = icmp eq i64 %A, 0 | ||||
1704 | /// br i1 %cmpz, label %cond.end, label %cond.false | ||||
1705 | /// cond.false: | ||||
1706 | /// %z = call i64 @llvm.cttz.i64(i64 %A, i1 true) | ||||
1707 | /// br label %cond.end | ||||
1708 | /// cond.end: | ||||
1709 | /// %ctz = phi i64 [ 64, %entry ], [ %z, %cond.false ] | ||||
1710 | /// | ||||
1711 | /// If the transform is performed, return true and set ModifiedDT to true. | ||||
1712 | static bool despeculateCountZeros(IntrinsicInst *CountZeros, | ||||
1713 | const TargetLowering *TLI, | ||||
1714 | const DataLayout *DL, | ||||
1715 | bool &ModifiedDT) { | ||||
1716 | if (!TLI || !DL) | ||||
1717 | return false; | ||||
1718 | |||||
1719 | // If a zero input is undefined, it doesn't make sense to despeculate that. | ||||
1720 | if (match(CountZeros->getOperand(1), m_One())) | ||||
1721 | return false; | ||||
1722 | |||||
1723 | // If it's cheap to speculate, there's nothing to do. | ||||
1724 | auto IntrinsicID = CountZeros->getIntrinsicID(); | ||||
1725 | if ((IntrinsicID == Intrinsic::cttz && TLI->isCheapToSpeculateCttz()) || | ||||
1726 | (IntrinsicID == Intrinsic::ctlz && TLI->isCheapToSpeculateCtlz())) | ||||
1727 | return false; | ||||
1728 | |||||
1729 | // Only handle legal scalar cases. Anything else requires too much work. | ||||
1730 | Type *Ty = CountZeros->getType(); | ||||
1731 | unsigned SizeInBits = Ty->getPrimitiveSizeInBits(); | ||||
1732 | if (Ty->isVectorTy() || SizeInBits > DL->getLargestLegalIntTypeSizeInBits()) | ||||
1733 | return false; | ||||
1734 | |||||
1735 | // The intrinsic will be sunk behind a compare against zero and branch. | ||||
1736 | BasicBlock *StartBlock = CountZeros->getParent(); | ||||
1737 | BasicBlock *CallBlock = StartBlock->splitBasicBlock(CountZeros, "cond.false"); | ||||
1738 | |||||
1739 | // Create another block after the count zero intrinsic. A PHI will be added | ||||
1740 | // in this block to select the result of the intrinsic or the bit-width | ||||
1741 | // constant if the input to the intrinsic is zero. | ||||
1742 | BasicBlock::iterator SplitPt = ++(BasicBlock::iterator(CountZeros)); | ||||
1743 | BasicBlock *EndBlock = CallBlock->splitBasicBlock(SplitPt, "cond.end"); | ||||
1744 | |||||
1745 | // Set up a builder to create a compare, conditional branch, and PHI. | ||||
1746 | IRBuilder<> Builder(CountZeros->getContext()); | ||||
1747 | Builder.SetInsertPoint(StartBlock->getTerminator()); | ||||
1748 | Builder.SetCurrentDebugLocation(CountZeros->getDebugLoc()); | ||||
1749 | |||||
1750 | // Replace the unconditional branch that was created by the first split with | ||||
1751 | // a compare against zero and a conditional branch. | ||||
1752 | Value *Zero = Constant::getNullValue(Ty); | ||||
1753 | Value *Cmp = Builder.CreateICmpEQ(CountZeros->getOperand(0), Zero, "cmpz"); | ||||
1754 | Builder.CreateCondBr(Cmp, EndBlock, CallBlock); | ||||
1755 | StartBlock->getTerminator()->eraseFromParent(); | ||||
1756 | |||||
1757 | // Create a PHI in the end block to select either the output of the intrinsic | ||||
1758 | // or the bit width of the operand. | ||||
1759 | Builder.SetInsertPoint(&EndBlock->front()); | ||||
1760 | PHINode *PN = Builder.CreatePHI(Ty, 2, "ctz"); | ||||
1761 | CountZeros->replaceAllUsesWith(PN); | ||||
1762 | Value *BitWidth = Builder.getInt(APInt(SizeInBits, SizeInBits)); | ||||
1763 | PN->addIncoming(BitWidth, StartBlock); | ||||
1764 | PN->addIncoming(CountZeros, CallBlock); | ||||
1765 | |||||
1766 | // We are explicitly handling the zero case, so we can set the intrinsic's | ||||
1767 | // undefined zero argument to 'true'. This will also prevent reprocessing the | ||||
1768 | // intrinsic; we only despeculate when a zero input is defined. | ||||
1769 | CountZeros->setArgOperand(1, Builder.getTrue()); | ||||
1770 | ModifiedDT = true; | ||||
1771 | return true; | ||||
1772 | } | ||||
1773 | |||||
1774 | bool CodeGenPrepare::optimizeCallInst(CallInst *CI, bool &ModifiedDT) { | ||||
1775 | BasicBlock *BB = CI->getParent(); | ||||
1776 | |||||
1777 | // Lower inline assembly if we can. | ||||
1778 | // If we found an inline asm expession, and if the target knows how to | ||||
1779 | // lower it to normal LLVM code, do so now. | ||||
1780 | if (TLI && isa<InlineAsm>(CI->getCalledValue())) { | ||||
1781 | if (TLI->ExpandInlineAsm(CI)) { | ||||
1782 | // Avoid invalidating the iterator. | ||||
1783 | CurInstIterator = BB->begin(); | ||||
1784 | // Avoid processing instructions out of order, which could cause | ||||
1785 | // reuse before a value is defined. | ||||
1786 | SunkAddrs.clear(); | ||||
1787 | return true; | ||||
1788 | } | ||||
1789 | // Sink address computing for memory operands into the block. | ||||
1790 | if (optimizeInlineAsmInst(CI)) | ||||
1791 | return true; | ||||
1792 | } | ||||
1793 | |||||
1794 | // Align the pointer arguments to this call if the target thinks it's a good | ||||
1795 | // idea | ||||
1796 | unsigned MinSize, PrefAlign; | ||||
1797 | if (TLI && TLI->shouldAlignPointerArgs(CI, MinSize, PrefAlign)) { | ||||
1798 | for (auto &Arg : CI->arg_operands()) { | ||||
1799 | // We want to align both objects whose address is used directly and | ||||
1800 | // objects whose address is used in casts and GEPs, though it only makes | ||||
1801 | // sense for GEPs if the offset is a multiple of the desired alignment and | ||||
1802 | // if size - offset meets the size threshold. | ||||
1803 | if (!Arg->getType()->isPointerTy()) | ||||
1804 | continue; | ||||
1805 | APInt Offset(DL->getIndexSizeInBits( | ||||
1806 | cast<PointerType>(Arg->getType())->getAddressSpace()), | ||||
1807 | 0); | ||||
1808 | Value *Val = Arg->stripAndAccumulateInBoundsConstantOffsets(*DL, Offset); | ||||
1809 | uint64_t Offset2 = Offset.getLimitedValue(); | ||||
1810 | if ((Offset2 & (PrefAlign-1)) != 0) | ||||
1811 | continue; | ||||
1812 | AllocaInst *AI; | ||||
1813 | if ((AI = dyn_cast<AllocaInst>(Val)) && AI->getAlignment() < PrefAlign && | ||||
1814 | DL->getTypeAllocSize(AI->getAllocatedType()) >= MinSize + Offset2) | ||||
1815 | AI->setAlignment(MaybeAlign(PrefAlign)); | ||||
1816 | // Global variables can only be aligned if they are defined in this | ||||
1817 | // object (i.e. they are uniquely initialized in this object), and | ||||
1818 | // over-aligning global variables that have an explicit section is | ||||
1819 | // forbidden. | ||||
1820 | GlobalVariable *GV; | ||||
1821 | if ((GV = dyn_cast<GlobalVariable>(Val)) && GV->canIncreaseAlignment() && | ||||
1822 | GV->getPointerAlignment(*DL) < PrefAlign && | ||||
1823 | DL->getTypeAllocSize(GV->getValueType()) >= | ||||
1824 | MinSize + Offset2) | ||||
1825 | GV->setAlignment(PrefAlign); | ||||
1826 | } | ||||
1827 | // If this is a memcpy (or similar) then we may be able to improve the | ||||
1828 | // alignment | ||||
1829 | if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(CI)) { | ||||
1830 | unsigned DestAlign = getKnownAlignment(MI->getDest(), *DL); | ||||
1831 | if (DestAlign > MI->getDestAlignment()) | ||||
1832 | MI->setDestAlignment(DestAlign); | ||||
1833 | if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI)) { | ||||
1834 | unsigned SrcAlign = getKnownAlignment(MTI->getSource(), *DL); | ||||
1835 | if (SrcAlign > MTI->getSourceAlignment()) | ||||
1836 | MTI->setSourceAlignment(SrcAlign); | ||||
1837 | } | ||||
1838 | } | ||||
1839 | } | ||||
1840 | |||||
1841 | // If we have a cold call site, try to sink addressing computation into the | ||||
1842 | // cold block. This interacts with our handling for loads and stores to | ||||
1843 | // ensure that we can fold all uses of a potential addressing computation | ||||
1844 | // into their uses. TODO: generalize this to work over profiling data | ||||
1845 | if (!OptSize && CI->hasFnAttr(Attribute::Cold)) | ||||
1846 | for (auto &Arg : CI->arg_operands()) { | ||||
1847 | if (!Arg->getType()->isPointerTy()) | ||||
1848 | continue; | ||||
1849 | unsigned AS = Arg->getType()->getPointerAddressSpace(); | ||||
1850 | return optimizeMemoryInst(CI, Arg, Arg->getType(), AS); | ||||
1851 | } | ||||
1852 | |||||
1853 | IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI); | ||||
1854 | if (II) { | ||||
1855 | switch (II->getIntrinsicID()) { | ||||
1856 | default: break; | ||||
1857 | case Intrinsic::experimental_widenable_condition: { | ||||
1858 | // Give up on future widening oppurtunties so that we can fold away dead | ||||
1859 | // paths and merge blocks before going into block-local instruction | ||||
1860 | // selection. | ||||
1861 | if (II->use_empty()) { | ||||
1862 | II->eraseFromParent(); | ||||
1863 | return true; | ||||
1864 | } | ||||
1865 | Constant *RetVal = ConstantInt::getTrue(II->getContext()); | ||||
1866 | resetIteratorIfInvalidatedWhileCalling(BB, [&]() { | ||||
1867 | replaceAndRecursivelySimplify(CI, RetVal, TLInfo, nullptr); | ||||
1868 | }); | ||||
1869 | return true; | ||||
1870 | } | ||||
1871 | case Intrinsic::objectsize: { | ||||
1872 | // Lower all uses of llvm.objectsize.* | ||||
1873 | Value *RetVal = | ||||
1874 | lowerObjectSizeCall(II, *DL, TLInfo, /*MustSucceed=*/true); | ||||
1875 | |||||
1876 | resetIteratorIfInvalidatedWhileCalling(BB, [&]() { | ||||
1877 | replaceAndRecursivelySimplify(CI, RetVal, TLInfo, nullptr); | ||||
1878 | }); | ||||
1879 | return true; | ||||
1880 | } | ||||
1881 | case Intrinsic::is_constant: { | ||||
1882 | // If is_constant hasn't folded away yet, lower it to false now. | ||||
1883 | Constant *RetVal = ConstantInt::get(II->getType(), 0); | ||||
1884 | resetIteratorIfInvalidatedWhileCalling(BB, [&]() { | ||||
1885 | replaceAndRecursivelySimplify(CI, RetVal, TLInfo, nullptr); | ||||
1886 | }); | ||||
1887 | return true; | ||||
1888 | } | ||||
1889 | case Intrinsic::aarch64_stlxr: | ||||
1890 | case Intrinsic::aarch64_stxr: { | ||||
1891 | ZExtInst *ExtVal = dyn_cast<ZExtInst>(CI->getArgOperand(0)); | ||||
1892 | if (!ExtVal || !ExtVal->hasOneUse() || | ||||
1893 | ExtVal->getParent() == CI->getParent()) | ||||
1894 | return false; | ||||
1895 | // Sink a zext feeding stlxr/stxr before it, so it can be folded into it. | ||||
1896 | ExtVal->moveBefore(CI); | ||||
1897 | // Mark this instruction as "inserted by CGP", so that other | ||||
1898 | // optimizations don't touch it. | ||||
1899 | InsertedInsts.insert(ExtVal); | ||||
1900 | return true; | ||||
1901 | } | ||||
1902 | |||||
1903 | case Intrinsic::launder_invariant_group: | ||||
1904 | case Intrinsic::strip_invariant_group: { | ||||
1905 | Value *ArgVal = II->getArgOperand(0); | ||||
1906 | auto it = LargeOffsetGEPMap.find(II); | ||||
1907 | if (it != LargeOffsetGEPMap.end()) { | ||||
1908 | // Merge entries in LargeOffsetGEPMap to reflect the RAUW. | ||||
1909 | // Make sure not to have to deal with iterator invalidation | ||||
1910 | // after possibly adding ArgVal to LargeOffsetGEPMap. | ||||
1911 | auto GEPs = std::move(it->second); | ||||
1912 | LargeOffsetGEPMap[ArgVal].append(GEPs.begin(), GEPs.end()); | ||||
1913 | LargeOffsetGEPMap.erase(II); | ||||
1914 | } | ||||
1915 | |||||
1916 | II->replaceAllUsesWith(ArgVal); | ||||
1917 | II->eraseFromParent(); | ||||
1918 | return true; | ||||
1919 | } | ||||
1920 | case Intrinsic::cttz: | ||||
1921 | case Intrinsic::ctlz: | ||||
1922 | // If counting zeros is expensive, try to avoid it. | ||||
1923 | return despeculateCountZeros(II, TLI, DL, ModifiedDT); | ||||
1924 | } | ||||
1925 | |||||
1926 | if (TLI) { | ||||
1927 | SmallVector<Value*, 2> PtrOps; | ||||
1928 | Type *AccessTy; | ||||
1929 | if (TLI->getAddrModeArguments(II, PtrOps, AccessTy)) | ||||
1930 | while (!PtrOps.empty()) { | ||||
1931 | Value *PtrVal = PtrOps.pop_back_val(); | ||||
1932 | unsigned AS = PtrVal->getType()->getPointerAddressSpace(); | ||||
1933 | if (optimizeMemoryInst(II, PtrVal, AccessTy, AS)) | ||||
1934 | return true; | ||||
1935 | } | ||||
1936 | } | ||||
1937 | } | ||||
1938 | |||||
1939 | // From here on out we're working with named functions. | ||||
1940 | if (!CI->getCalledFunction()) return false; | ||||
1941 | |||||
1942 | // Lower all default uses of _chk calls. This is very similar | ||||
1943 | // to what InstCombineCalls does, but here we are only lowering calls | ||||
1944 | // to fortified library functions (e.g. __memcpy_chk) that have the default | ||||
1945 | // "don't know" as the objectsize. Anything else should be left alone. | ||||
1946 | FortifiedLibCallSimplifier Simplifier(TLInfo, true); | ||||
1947 | if (Value *V = Simplifier.optimizeCall(CI)) { | ||||
1948 | CI->replaceAllUsesWith(V); | ||||
1949 | CI->eraseFromParent(); | ||||
1950 | return true; | ||||
1951 | } | ||||
1952 | |||||
1953 | return false; | ||||
1954 | } | ||||
1955 | |||||
1956 | /// Look for opportunities to duplicate return instructions to the predecessor | ||||
1957 | /// to enable tail call optimizations. The case it is currently looking for is: | ||||
1958 | /// @code | ||||
1959 | /// bb0: | ||||
1960 | /// %tmp0 = tail call i32 @f0() | ||||
1961 | /// br label %return | ||||
1962 | /// bb1: | ||||
1963 | /// %tmp1 = tail call i32 @f1() | ||||
1964 | /// br label %return | ||||
1965 | /// bb2: | ||||
1966 | /// %tmp2 = tail call i32 @f2() | ||||
1967 | /// br label %return | ||||
1968 | /// return: | ||||
1969 | /// %retval = phi i32 [ %tmp0, %bb0 ], [ %tmp1, %bb1 ], [ %tmp2, %bb2 ] | ||||
1970 | /// ret i32 %retval | ||||
1971 | /// @endcode | ||||
1972 | /// | ||||
1973 | /// => | ||||
1974 | /// | ||||
1975 | /// @code | ||||
1976 | /// bb0: | ||||
1977 | /// %tmp0 = tail call i32 @f0() | ||||
1978 | /// ret i32 %tmp0 | ||||
1979 | /// bb1: | ||||
1980 | /// %tmp1 = tail call i32 @f1() | ||||
1981 | /// ret i32 %tmp1 | ||||
1982 | /// bb2: | ||||
1983 | /// %tmp2 = tail call i32 @f2() | ||||
1984 | /// ret i32 %tmp2 | ||||
1985 | /// @endcode | ||||
1986 | bool CodeGenPrepare::dupRetToEnableTailCallOpts(BasicBlock *BB, bool &ModifiedDT) { | ||||
1987 | if (!TLI) | ||||
1988 | return false; | ||||
1989 | |||||
1990 | ReturnInst *RetI = dyn_cast<ReturnInst>(BB->getTerminator()); | ||||
1991 | if (!RetI) | ||||
1992 | return false; | ||||
1993 | |||||
1994 | PHINode *PN = nullptr; | ||||
1995 | BitCastInst *BCI = nullptr; | ||||
1996 | Value *V = RetI->getReturnValue(); | ||||
1997 | if (V) { | ||||
1998 | BCI = dyn_cast<BitCastInst>(V); | ||||
1999 | if (BCI) | ||||
2000 | V = BCI->getOperand(0); | ||||
2001 | |||||
2002 | PN = dyn_cast<PHINode>(V); | ||||
2003 | if (!PN) | ||||
2004 | return false; | ||||
2005 | } | ||||
2006 | |||||
2007 | if (PN && PN->getParent() != BB) | ||||
2008 | return false; | ||||
2009 | |||||
2010 | // Make sure there are no instructions between the PHI and return, or that the | ||||
2011 | // return is the first instruction in the block. | ||||
2012 | if (PN) { | ||||
2013 | BasicBlock::iterator BI = BB->begin(); | ||||
2014 | // Skip over debug and the bitcast. | ||||
2015 | do { ++BI; } while (isa<DbgInfoIntrinsic>(BI) || &*BI == BCI); | ||||
2016 | if (&*BI != RetI) | ||||
2017 | return false; | ||||
2018 | } else { | ||||
2019 | BasicBlock::iterator BI = BB->begin(); | ||||
2020 | while (isa<DbgInfoIntrinsic>(BI)) ++BI; | ||||
2021 | if (&*BI != RetI) | ||||
2022 | return false; | ||||
2023 | } | ||||
2024 | |||||
2025 | /// Only dup the ReturnInst if the CallInst is likely to be emitted as a tail | ||||
2026 | /// call. | ||||
2027 | const Function *F = BB->getParent(); | ||||
2028 | SmallVector<BasicBlock*, 4> TailCallBBs; | ||||
2029 | if (PN) { | ||||
2030 | for (unsigned I = 0, E = PN->getNumIncomingValues(); I != E; ++I) { | ||||
2031 | // Look through bitcasts. | ||||
2032 | Value *IncomingVal = PN->getIncomingValue(I)->stripPointerCasts(); | ||||
2033 | CallInst *CI = dyn_cast<CallInst>(IncomingVal); | ||||
2034 | BasicBlock *PredBB = PN->getIncomingBlock(I); | ||||
2035 | // Make sure the phi value is indeed produced by the tail call. | ||||
2036 | if (CI && CI->hasOneUse() && CI->getParent() == PredBB && | ||||
2037 | TLI->mayBeEmittedAsTailCall(CI) && | ||||
2038 | attributesPermitTailCall(F, CI, RetI, *TLI)) | ||||
2039 | TailCallBBs.push_back(PredBB); | ||||
2040 | } | ||||
2041 | } else { | ||||
2042 | SmallPtrSet<BasicBlock*, 4> VisitedBBs; | ||||
2043 | for (pred_iterator PI = pred_begin(BB), PE = pred_end(BB); PI != PE; ++PI) { | ||||
2044 | if (!VisitedBBs.insert(*PI).second) | ||||
2045 | continue; | ||||
2046 | |||||
2047 | BasicBlock::InstListType &InstList = (*PI)->getInstList(); | ||||
2048 | BasicBlock::InstListType::reverse_iterator RI = InstList.rbegin(); | ||||
2049 | BasicBlock::InstListType::reverse_iterator RE = InstList.rend(); | ||||
2050 | do { ++RI; } while (RI != RE && isa<DbgInfoIntrinsic>(&*RI)); | ||||
2051 | if (RI == RE) | ||||
2052 | continue; | ||||
2053 | |||||
2054 | CallInst *CI = dyn_cast<CallInst>(&*RI); | ||||
2055 | if (CI && CI->use_empty() && TLI->mayBeEmittedAsTailCall(CI) && | ||||
2056 | attributesPermitTailCall(F, CI, RetI, *TLI)) | ||||
2057 | TailCallBBs.push_back(*PI); | ||||
2058 | } | ||||
2059 | } | ||||
2060 | |||||
2061 | bool Changed = false; | ||||
2062 | for (auto const &TailCallBB : TailCallBBs) { | ||||
2063 | // Make sure the call instruction is followed by an unconditional branch to | ||||
2064 | // the return block. | ||||
2065 | BranchInst *BI = dyn_cast<BranchInst>(TailCallBB->getTerminator()); | ||||
2066 | if (!BI || !BI->isUnconditional() || BI->getSuccessor(0) != BB) | ||||
2067 | continue; | ||||
2068 | |||||
2069 | // Duplicate the return into TailCallBB. | ||||
2070 | (void)FoldReturnIntoUncondBranch(RetI, BB, TailCallBB); | ||||
2071 | ModifiedDT = Changed = true; | ||||
2072 | ++NumRetsDup; | ||||
2073 | } | ||||
2074 | |||||
2075 | // If we eliminated all predecessors of the block, delete the block now. | ||||
2076 | if (Changed && !BB->hasAddressTaken() && pred_begin(BB) == pred_end(BB)) | ||||
2077 | BB->eraseFromParent(); | ||||
2078 | |||||
2079 | return Changed; | ||||
2080 | } | ||||
2081 | |||||
2082 | //===----------------------------------------------------------------------===// | ||||
2083 | // Memory Optimization | ||||
2084 | //===----------------------------------------------------------------------===// | ||||
2085 | |||||
2086 | namespace { | ||||
2087 | |||||
2088 | /// This is an extended version of TargetLowering::AddrMode | ||||
2089 | /// which holds actual Value*'s for register values. | ||||
2090 | struct ExtAddrMode : public TargetLowering::AddrMode { | ||||
2091 | Value *BaseReg = nullptr; | ||||
2092 | Value *ScaledReg = nullptr; | ||||
2093 | Value *OriginalValue = nullptr; | ||||
2094 | bool InBounds = true; | ||||
2095 | |||||
2096 | enum FieldName { | ||||
2097 | NoField = 0x00, | ||||
2098 | BaseRegField = 0x01, | ||||
2099 | BaseGVField = 0x02, | ||||
2100 | BaseOffsField = 0x04, | ||||
2101 | ScaledRegField = 0x08, | ||||
2102 | ScaleField = 0x10, | ||||
2103 | MultipleFields = 0xff | ||||
2104 | }; | ||||
2105 | |||||
2106 | |||||
2107 | ExtAddrMode() = default; | ||||
2108 | |||||
2109 | void print(raw_ostream &OS) const; | ||||
2110 | void dump() const; | ||||
2111 | |||||
2112 | FieldName compare(const ExtAddrMode &other) { | ||||
2113 | // First check that the types are the same on each field, as differing types | ||||
2114 | // is something we can't cope with later on. | ||||
2115 | if (BaseReg && other.BaseReg && | ||||
2116 | BaseReg->getType() != other.BaseReg->getType()) | ||||
2117 | return MultipleFields; | ||||
2118 | if (BaseGV && other.BaseGV && | ||||
2119 | BaseGV->getType() != other.BaseGV->getType()) | ||||
2120 | return MultipleFields; | ||||
2121 | if (ScaledReg && other.ScaledReg && | ||||
2122 | ScaledReg->getType() != other.ScaledReg->getType()) | ||||
2123 | return MultipleFields; | ||||
2124 | |||||
2125 | // Conservatively reject 'inbounds' mismatches. | ||||
2126 | if (InBounds != other.InBounds) | ||||
2127 | return MultipleFields; | ||||
2128 | |||||
2129 | // Check each field to see if it differs. | ||||
2130 | unsigned Result = NoField; | ||||
2131 | if (BaseReg != other.BaseReg) | ||||
2132 | Result |= BaseRegField; | ||||
2133 | if (BaseGV != other.BaseGV) | ||||
2134 | Result |= BaseGVField; | ||||
2135 | if (BaseOffs != other.BaseOffs) | ||||
2136 | Result |= BaseOffsField; | ||||
2137 | if (ScaledReg != other.ScaledReg) | ||||
2138 | Result |= ScaledRegField; | ||||
2139 | // Don't count 0 as being a different scale, because that actually means | ||||
2140 | // unscaled (which will already be counted by having no ScaledReg). | ||||
2141 | if (Scale && other.Scale && Scale != other.Scale) | ||||
2142 | Result |= ScaleField; | ||||
2143 | |||||
2144 | if (countPopulation(Result) > 1) | ||||
2145 | return MultipleFields; | ||||
2146 | else | ||||
2147 | return static_cast<FieldName>(Result); | ||||
2148 | } | ||||
2149 | |||||
2150 | // An AddrMode is trivial if it involves no calculation i.e. it is just a base | ||||
2151 | // with no offset. | ||||
2152 | bool isTrivial() { | ||||
2153 | // An AddrMode is (BaseGV + BaseReg + BaseOffs + ScaleReg * Scale) so it is | ||||
2154 | // trivial if at most one of these terms is nonzero, except that BaseGV and | ||||
2155 | // BaseReg both being zero actually means a null pointer value, which we | ||||
2156 | // consider to be 'non-zero' here. | ||||
2157 | return !BaseOffs && !Scale && !(BaseGV && BaseReg); | ||||
2158 | } | ||||
2159 | |||||
2160 | Value *GetFieldAsValue(FieldName Field, Type *IntPtrTy) { | ||||
2161 | switch (Field) { | ||||
2162 | default: | ||||
2163 | return nullptr; | ||||
2164 | case BaseRegField: | ||||
2165 | return BaseReg; | ||||
2166 | case BaseGVField: | ||||
2167 | return BaseGV; | ||||
2168 | case ScaledRegField: | ||||
2169 | return ScaledReg; | ||||
2170 | case BaseOffsField: | ||||
2171 | return ConstantInt::get(IntPtrTy, BaseOffs); | ||||
2172 | } | ||||
2173 | } | ||||
2174 | |||||
2175 | void SetCombinedField(FieldName Field, Value *V, | ||||
2176 | const SmallVectorImpl<ExtAddrMode> &AddrModes) { | ||||
2177 | switch (Field) { | ||||
2178 | default: | ||||
2179 | llvm_unreachable("Unhandled fields are expected to be rejected earlier")::llvm::llvm_unreachable_internal("Unhandled fields are expected to be rejected earlier" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 2179); | ||||
2180 | break; | ||||
2181 | case ExtAddrMode::BaseRegField: | ||||
2182 | BaseReg = V; | ||||
2183 | break; | ||||
2184 | case ExtAddrMode::BaseGVField: | ||||
2185 | // A combined BaseGV is an Instruction, not a GlobalValue, so it goes | ||||
2186 | // in the BaseReg field. | ||||
2187 | assert(BaseReg == nullptr)((BaseReg == nullptr) ? static_cast<void> (0) : __assert_fail ("BaseReg == nullptr", "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 2187, __PRETTY_FUNCTION__)); | ||||
2188 | BaseReg = V; | ||||
2189 | BaseGV = nullptr; | ||||
2190 | break; | ||||
2191 | case ExtAddrMode::ScaledRegField: | ||||
2192 | ScaledReg = V; | ||||
2193 | // If we have a mix of scaled and unscaled addrmodes then we want scale | ||||
2194 | // to be the scale and not zero. | ||||
2195 | if (!Scale) | ||||
2196 | for (const ExtAddrMode &AM : AddrModes) | ||||
2197 | if (AM.Scale) { | ||||
2198 | Scale = AM.Scale; | ||||
2199 | break; | ||||
2200 | } | ||||
2201 | break; | ||||
2202 | case ExtAddrMode::BaseOffsField: | ||||
2203 | // The offset is no longer a constant, so it goes in ScaledReg with a | ||||
2204 | // scale of 1. | ||||
2205 | assert(ScaledReg == nullptr)((ScaledReg == nullptr) ? static_cast<void> (0) : __assert_fail ("ScaledReg == nullptr", "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 2205, __PRETTY_FUNCTION__)); | ||||
2206 | ScaledReg = V; | ||||
2207 | Scale = 1; | ||||
2208 | BaseOffs = 0; | ||||
2209 | break; | ||||
2210 | } | ||||
2211 | } | ||||
2212 | }; | ||||
2213 | |||||
2214 | } // end anonymous namespace | ||||
2215 | |||||
2216 | #ifndef NDEBUG | ||||
2217 | static inline raw_ostream &operator<<(raw_ostream &OS, const ExtAddrMode &AM) { | ||||
2218 | AM.print(OS); | ||||
2219 | return OS; | ||||
2220 | } | ||||
2221 | #endif | ||||
2222 | |||||
2223 | #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) | ||||
2224 | void ExtAddrMode::print(raw_ostream &OS) const { | ||||
2225 | bool NeedPlus = false; | ||||
2226 | OS << "["; | ||||
2227 | if (InBounds) | ||||
2228 | OS << "inbounds "; | ||||
2229 | if (BaseGV) { | ||||
2230 | OS << (NeedPlus ? " + " : "") | ||||
2231 | << "GV:"; | ||||
2232 | BaseGV->printAsOperand(OS, /*PrintType=*/false); | ||||
2233 | NeedPlus = true; | ||||
2234 | } | ||||
2235 | |||||
2236 | if (BaseOffs) { | ||||
2237 | OS << (NeedPlus ? " + " : "") | ||||
2238 | << BaseOffs; | ||||
2239 | NeedPlus = true; | ||||
2240 | } | ||||
2241 | |||||
2242 | if (BaseReg) { | ||||
2243 | OS << (NeedPlus ? " + " : "") | ||||
2244 | << "Base:"; | ||||
2245 | BaseReg->printAsOperand(OS, /*PrintType=*/false); | ||||
2246 | NeedPlus = true; | ||||
2247 | } | ||||
2248 | if (Scale) { | ||||
2249 | OS << (NeedPlus ? " + " : "") | ||||
2250 | << Scale << "*"; | ||||
2251 | ScaledReg->printAsOperand(OS, /*PrintType=*/false); | ||||
2252 | } | ||||
2253 | |||||
2254 | OS << ']'; | ||||
2255 | } | ||||
2256 | |||||
2257 | LLVM_DUMP_METHOD__attribute__((noinline)) __attribute__((__used__)) void ExtAddrMode::dump() const { | ||||
2258 | print(dbgs()); | ||||
2259 | dbgs() << '\n'; | ||||
2260 | } | ||||
2261 | #endif | ||||
2262 | |||||
2263 | namespace { | ||||
2264 | |||||
2265 | /// This class provides transaction based operation on the IR. | ||||
2266 | /// Every change made through this class is recorded in the internal state and | ||||
2267 | /// can be undone (rollback) until commit is called. | ||||
2268 | class TypePromotionTransaction { | ||||
2269 | /// This represents the common interface of the individual transaction. | ||||
2270 | /// Each class implements the logic for doing one specific modification on | ||||
2271 | /// the IR via the TypePromotionTransaction. | ||||
2272 | class TypePromotionAction { | ||||
2273 | protected: | ||||
2274 | /// The Instruction modified. | ||||
2275 | Instruction *Inst; | ||||
2276 | |||||
2277 | public: | ||||
2278 | /// Constructor of the action. | ||||
2279 | /// The constructor performs the related action on the IR. | ||||
2280 | TypePromotionAction(Instruction *Inst) : Inst(Inst) {} | ||||
2281 | |||||
2282 | virtual ~TypePromotionAction() = default; | ||||
2283 | |||||
2284 | /// Undo the modification done by this action. | ||||
2285 | /// When this method is called, the IR must be in the same state as it was | ||||
2286 | /// before this action was applied. | ||||
2287 | /// \pre Undoing the action works if and only if the IR is in the exact same | ||||
2288 | /// state as it was directly after this action was applied. | ||||
2289 | virtual void undo() = 0; | ||||
2290 | |||||
2291 | /// Advocate every change made by this action. | ||||
2292 | /// When the results on the IR of the action are to be kept, it is important | ||||
2293 | /// to call this function, otherwise hidden information may be kept forever. | ||||
2294 | virtual void commit() { | ||||
2295 | // Nothing to be done, this action is not doing anything. | ||||
2296 | } | ||||
2297 | }; | ||||
2298 | |||||
2299 | /// Utility to remember the position of an instruction. | ||||
2300 | class InsertionHandler { | ||||
2301 | /// Position of an instruction. | ||||
2302 | /// Either an instruction: | ||||
2303 | /// - Is the first in a basic block: BB is used. | ||||
2304 | /// - Has a previous instruction: PrevInst is used. | ||||
2305 | union { | ||||
2306 | Instruction *PrevInst; | ||||
2307 | BasicBlock *BB; | ||||
2308 | } Point; | ||||
2309 | |||||
2310 | /// Remember whether or not the instruction had a previous instruction. | ||||
2311 | bool HasPrevInstruction; | ||||
2312 | |||||
2313 | public: | ||||
2314 | /// Record the position of \p Inst. | ||||
2315 | InsertionHandler(Instruction *Inst) { | ||||
2316 | BasicBlock::iterator It = Inst->getIterator(); | ||||
2317 | HasPrevInstruction = (It != (Inst->getParent()->begin())); | ||||
2318 | if (HasPrevInstruction) | ||||
2319 | Point.PrevInst = &*--It; | ||||
2320 | else | ||||
2321 | Point.BB = Inst->getParent(); | ||||
2322 | } | ||||
2323 | |||||
2324 | /// Insert \p Inst at the recorded position. | ||||
2325 | void insert(Instruction *Inst) { | ||||
2326 | if (HasPrevInstruction) { | ||||
2327 | if (Inst->getParent()) | ||||
2328 | Inst->removeFromParent(); | ||||
2329 | Inst->insertAfter(Point.PrevInst); | ||||
2330 | } else { | ||||
2331 | Instruction *Position = &*Point.BB->getFirstInsertionPt(); | ||||
2332 | if (Inst->getParent()) | ||||
2333 | Inst->moveBefore(Position); | ||||
2334 | else | ||||
2335 | Inst->insertBefore(Position); | ||||
2336 | } | ||||
2337 | } | ||||
2338 | }; | ||||
2339 | |||||
2340 | /// Move an instruction before another. | ||||
2341 | class InstructionMoveBefore : public TypePromotionAction { | ||||
2342 | /// Original position of the instruction. | ||||
2343 | InsertionHandler Position; | ||||
2344 | |||||
2345 | public: | ||||
2346 | /// Move \p Inst before \p Before. | ||||
2347 | InstructionMoveBefore(Instruction *Inst, Instruction *Before) | ||||
2348 | : TypePromotionAction(Inst), Position(Inst) { | ||||
2349 | LLVM_DEBUG(dbgs() << "Do: move: " << *Inst << "\nbefore: " << *Beforedo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Do: move: " << * Inst << "\nbefore: " << *Before << "\n"; } } while (false) | ||||
2350 | << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Do: move: " << * Inst << "\nbefore: " << *Before << "\n"; } } while (false); | ||||
2351 | Inst->moveBefore(Before); | ||||
2352 | } | ||||
2353 | |||||
2354 | /// Move the instruction back to its original position. | ||||
2355 | void undo() override { | ||||
2356 | LLVM_DEBUG(dbgs() << "Undo: moveBefore: " << *Inst << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Undo: moveBefore: " << *Inst << "\n"; } } while (false); | ||||
2357 | Position.insert(Inst); | ||||
2358 | } | ||||
2359 | }; | ||||
2360 | |||||
2361 | /// Set the operand of an instruction with a new value. | ||||
2362 | class OperandSetter : public TypePromotionAction { | ||||
2363 | /// Original operand of the instruction. | ||||
2364 | Value *Origin; | ||||
2365 | |||||
2366 | /// Index of the modified instruction. | ||||
2367 | unsigned Idx; | ||||
2368 | |||||
2369 | public: | ||||
2370 | /// Set \p Idx operand of \p Inst with \p NewVal. | ||||
2371 | OperandSetter(Instruction *Inst, unsigned Idx, Value *NewVal) | ||||
2372 | : TypePromotionAction(Inst), Idx(Idx) { | ||||
2373 | LLVM_DEBUG(dbgs() << "Do: setOperand: " << Idx << "\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Do: setOperand: " << Idx << "\n" << "for:" << *Inst << "\n" << "with:" << *NewVal << "\n"; } } while ( false) | ||||
2374 | << "for:" << *Inst << "\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Do: setOperand: " << Idx << "\n" << "for:" << *Inst << "\n" << "with:" << *NewVal << "\n"; } } while ( false) | ||||
2375 | << "with:" << *NewVal << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Do: setOperand: " << Idx << "\n" << "for:" << *Inst << "\n" << "with:" << *NewVal << "\n"; } } while ( false); | ||||
2376 | Origin = Inst->getOperand(Idx); | ||||
2377 | Inst->setOperand(Idx, NewVal); | ||||
2378 | } | ||||
2379 | |||||
2380 | /// Restore the original value of the instruction. | ||||
2381 | void undo() override { | ||||
2382 | LLVM_DEBUG(dbgs() << "Undo: setOperand:" << Idx << "\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Undo: setOperand:" << Idx << "\n" << "for: " << *Inst << "\n" << "with: " << *Origin << "\n"; } } while ( false) | ||||
2383 | << "for: " << *Inst << "\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Undo: setOperand:" << Idx << "\n" << "for: " << *Inst << "\n" << "with: " << *Origin << "\n"; } } while ( false) | ||||
2384 | << "with: " << *Origin << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Undo: setOperand:" << Idx << "\n" << "for: " << *Inst << "\n" << "with: " << *Origin << "\n"; } } while ( false); | ||||
2385 | Inst->setOperand(Idx, Origin); | ||||
2386 | } | ||||
2387 | }; | ||||
2388 | |||||
2389 | /// Hide the operands of an instruction. | ||||
2390 | /// Do as if this instruction was not using any of its operands. | ||||
2391 | class OperandsHider : public TypePromotionAction { | ||||
2392 | /// The list of original operands. | ||||
2393 | SmallVector<Value *, 4> OriginalValues; | ||||
2394 | |||||
2395 | public: | ||||
2396 | /// Remove \p Inst from the uses of the operands of \p Inst. | ||||
2397 | OperandsHider(Instruction *Inst) : TypePromotionAction(Inst) { | ||||
2398 | LLVM_DEBUG(dbgs() << "Do: OperandsHider: " << *Inst << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Do: OperandsHider: " << *Inst << "\n"; } } while (false); | ||||
2399 | unsigned NumOpnds = Inst->getNumOperands(); | ||||
2400 | OriginalValues.reserve(NumOpnds); | ||||
2401 | for (unsigned It = 0; It < NumOpnds; ++It) { | ||||
2402 | // Save the current operand. | ||||
2403 | Value *Val = Inst->getOperand(It); | ||||
2404 | OriginalValues.push_back(Val); | ||||
2405 | // Set a dummy one. | ||||
2406 | // We could use OperandSetter here, but that would imply an overhead | ||||
2407 | // that we are not willing to pay. | ||||
2408 | Inst->setOperand(It, UndefValue::get(Val->getType())); | ||||
2409 | } | ||||
2410 | } | ||||
2411 | |||||
2412 | /// Restore the original list of uses. | ||||
2413 | void undo() override { | ||||
2414 | LLVM_DEBUG(dbgs() << "Undo: OperandsHider: " << *Inst << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Undo: OperandsHider: " << *Inst << "\n"; } } while (false); | ||||
2415 | for (unsigned It = 0, EndIt = OriginalValues.size(); It != EndIt; ++It) | ||||
2416 | Inst->setOperand(It, OriginalValues[It]); | ||||
2417 | } | ||||
2418 | }; | ||||
2419 | |||||
2420 | /// Build a truncate instruction. | ||||
2421 | class TruncBuilder : public TypePromotionAction { | ||||
2422 | Value *Val; | ||||
2423 | |||||
2424 | public: | ||||
2425 | /// Build a truncate instruction of \p Opnd producing a \p Ty | ||||
2426 | /// result. | ||||
2427 | /// trunc Opnd to Ty. | ||||
2428 | TruncBuilder(Instruction *Opnd, Type *Ty) : TypePromotionAction(Opnd) { | ||||
2429 | IRBuilder<> Builder(Opnd); | ||||
2430 | Val = Builder.CreateTrunc(Opnd, Ty, "promoted"); | ||||
2431 | LLVM_DEBUG(dbgs() << "Do: TruncBuilder: " << *Val << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Do: TruncBuilder: " << *Val << "\n"; } } while (false); | ||||
2432 | } | ||||
2433 | |||||
2434 | /// Get the built value. | ||||
2435 | Value *getBuiltValue() { return Val; } | ||||
2436 | |||||
2437 | /// Remove the built instruction. | ||||
2438 | void undo() override { | ||||
2439 | LLVM_DEBUG(dbgs() << "Undo: TruncBuilder: " << *Val << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Undo: TruncBuilder: " << *Val << "\n"; } } while (false); | ||||
2440 | if (Instruction *IVal = dyn_cast<Instruction>(Val)) | ||||
2441 | IVal->eraseFromParent(); | ||||
2442 | } | ||||
2443 | }; | ||||
2444 | |||||
2445 | /// Build a sign extension instruction. | ||||
2446 | class SExtBuilder : public TypePromotionAction { | ||||
2447 | Value *Val; | ||||
2448 | |||||
2449 | public: | ||||
2450 | /// Build a sign extension instruction of \p Opnd producing a \p Ty | ||||
2451 | /// result. | ||||
2452 | /// sext Opnd to Ty. | ||||
2453 | SExtBuilder(Instruction *InsertPt, Value *Opnd, Type *Ty) | ||||
2454 | : TypePromotionAction(InsertPt) { | ||||
2455 | IRBuilder<> Builder(InsertPt); | ||||
2456 | Val = Builder.CreateSExt(Opnd, Ty, "promoted"); | ||||
2457 | LLVM_DEBUG(dbgs() << "Do: SExtBuilder: " << *Val << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Do: SExtBuilder: " << *Val << "\n"; } } while (false); | ||||
2458 | } | ||||
2459 | |||||
2460 | /// Get the built value. | ||||
2461 | Value *getBuiltValue() { return Val; } | ||||
2462 | |||||
2463 | /// Remove the built instruction. | ||||
2464 | void undo() override { | ||||
2465 | LLVM_DEBUG(dbgs() << "Undo: SExtBuilder: " << *Val << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Undo: SExtBuilder: " << *Val << "\n"; } } while (false); | ||||
2466 | if (Instruction *IVal = dyn_cast<Instruction>(Val)) | ||||
2467 | IVal->eraseFromParent(); | ||||
2468 | } | ||||
2469 | }; | ||||
2470 | |||||
2471 | /// Build a zero extension instruction. | ||||
2472 | class ZExtBuilder : public TypePromotionAction { | ||||
2473 | Value *Val; | ||||
2474 | |||||
2475 | public: | ||||
2476 | /// Build a zero extension instruction of \p Opnd producing a \p Ty | ||||
2477 | /// result. | ||||
2478 | /// zext Opnd to Ty. | ||||
2479 | ZExtBuilder(Instruction *InsertPt, Value *Opnd, Type *Ty) | ||||
2480 | : TypePromotionAction(InsertPt) { | ||||
2481 | IRBuilder<> Builder(InsertPt); | ||||
2482 | Val = Builder.CreateZExt(Opnd, Ty, "promoted"); | ||||
2483 | LLVM_DEBUG(dbgs() << "Do: ZExtBuilder: " << *Val << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Do: ZExtBuilder: " << *Val << "\n"; } } while (false); | ||||
2484 | } | ||||
2485 | |||||
2486 | /// Get the built value. | ||||
2487 | Value *getBuiltValue() { return Val; } | ||||
2488 | |||||
2489 | /// Remove the built instruction. | ||||
2490 | void undo() override { | ||||
2491 | LLVM_DEBUG(dbgs() << "Undo: ZExtBuilder: " << *Val << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Undo: ZExtBuilder: " << *Val << "\n"; } } while (false); | ||||
2492 | if (Instruction *IVal = dyn_cast<Instruction>(Val)) | ||||
2493 | IVal->eraseFromParent(); | ||||
2494 | } | ||||
2495 | }; | ||||
2496 | |||||
2497 | /// Mutate an instruction to another type. | ||||
2498 | class TypeMutator : public TypePromotionAction { | ||||
2499 | /// Record the original type. | ||||
2500 | Type *OrigTy; | ||||
2501 | |||||
2502 | public: | ||||
2503 | /// Mutate the type of \p Inst into \p NewTy. | ||||
2504 | TypeMutator(Instruction *Inst, Type *NewTy) | ||||
2505 | : TypePromotionAction(Inst), OrigTy(Inst->getType()) { | ||||
2506 | LLVM_DEBUG(dbgs() << "Do: MutateType: " << *Inst << " with " << *NewTydo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Do: MutateType: " << *Inst << " with " << *NewTy << "\n"; } } while (false) | ||||
2507 | << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Do: MutateType: " << *Inst << " with " << *NewTy << "\n"; } } while (false); | ||||
2508 | Inst->mutateType(NewTy); | ||||
2509 | } | ||||
2510 | |||||
2511 | /// Mutate the instruction back to its original type. | ||||
2512 | void undo() override { | ||||
2513 | LLVM_DEBUG(dbgs() << "Undo: MutateType: " << *Inst << " with " << *OrigTydo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Undo: MutateType: " << *Inst << " with " << *OrigTy << "\n"; } } while (false) | ||||
2514 | << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Undo: MutateType: " << *Inst << " with " << *OrigTy << "\n"; } } while (false); | ||||
2515 | Inst->mutateType(OrigTy); | ||||
2516 | } | ||||
2517 | }; | ||||
2518 | |||||
2519 | /// Replace the uses of an instruction by another instruction. | ||||
2520 | class UsesReplacer : public TypePromotionAction { | ||||
2521 | /// Helper structure to keep track of the replaced uses. | ||||
2522 | struct InstructionAndIdx { | ||||
2523 | /// The instruction using the instruction. | ||||
2524 | Instruction *Inst; | ||||
2525 | |||||
2526 | /// The index where this instruction is used for Inst. | ||||
2527 | unsigned Idx; | ||||
2528 | |||||
2529 | InstructionAndIdx(Instruction *Inst, unsigned Idx) | ||||
2530 | : Inst(Inst), Idx(Idx) {} | ||||
2531 | }; | ||||
2532 | |||||
2533 | /// Keep track of the original uses (pair Instruction, Index). | ||||
2534 | SmallVector<InstructionAndIdx, 4> OriginalUses; | ||||
2535 | /// Keep track of the debug users. | ||||
2536 | SmallVector<DbgValueInst *, 1> DbgValues; | ||||
2537 | |||||
2538 | using use_iterator = SmallVectorImpl<InstructionAndIdx>::iterator; | ||||
2539 | |||||
2540 | public: | ||||
2541 | /// Replace all the use of \p Inst by \p New. | ||||
2542 | UsesReplacer(Instruction *Inst, Value *New) : TypePromotionAction(Inst) { | ||||
2543 | LLVM_DEBUG(dbgs() << "Do: UsersReplacer: " << *Inst << " with " << *Newdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Do: UsersReplacer: " << *Inst << " with " << *New << "\n"; } } while (false) | ||||
2544 | << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Do: UsersReplacer: " << *Inst << " with " << *New << "\n"; } } while (false); | ||||
2545 | // Record the original uses. | ||||
2546 | for (Use &U : Inst->uses()) { | ||||
2547 | Instruction *UserI = cast<Instruction>(U.getUser()); | ||||
2548 | OriginalUses.push_back(InstructionAndIdx(UserI, U.getOperandNo())); | ||||
2549 | } | ||||
2550 | // Record the debug uses separately. They are not in the instruction's | ||||
2551 | // use list, but they are replaced by RAUW. | ||||
2552 | findDbgValues(DbgValues, Inst); | ||||
2553 | |||||
2554 | // Now, we can replace the uses. | ||||
2555 | Inst->replaceAllUsesWith(New); | ||||
2556 | } | ||||
2557 | |||||
2558 | /// Reassign the original uses of Inst to Inst. | ||||
2559 | void undo() override { | ||||
2560 | LLVM_DEBUG(dbgs() << "Undo: UsersReplacer: " << *Inst << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Undo: UsersReplacer: " << *Inst << "\n"; } } while (false); | ||||
2561 | for (use_iterator UseIt = OriginalUses.begin(), | ||||
2562 | EndIt = OriginalUses.end(); | ||||
2563 | UseIt != EndIt; ++UseIt) { | ||||
2564 | UseIt->Inst->setOperand(UseIt->Idx, Inst); | ||||
2565 | } | ||||
2566 | // RAUW has replaced all original uses with references to the new value, | ||||
2567 | // including the debug uses. Since we are undoing the replacements, | ||||
2568 | // the original debug uses must also be reinstated to maintain the | ||||
2569 | // correctness and utility of debug value instructions. | ||||
2570 | for (auto *DVI: DbgValues) { | ||||
2571 | LLVMContext &Ctx = Inst->getType()->getContext(); | ||||
2572 | auto *MV = MetadataAsValue::get(Ctx, ValueAsMetadata::get(Inst)); | ||||
2573 | DVI->setOperand(0, MV); | ||||
2574 | } | ||||
2575 | } | ||||
2576 | }; | ||||
2577 | |||||
2578 | /// Remove an instruction from the IR. | ||||
2579 | class InstructionRemover : public TypePromotionAction { | ||||
2580 | /// Original position of the instruction. | ||||
2581 | InsertionHandler Inserter; | ||||
2582 | |||||
2583 | /// Helper structure to hide all the link to the instruction. In other | ||||
2584 | /// words, this helps to do as if the instruction was removed. | ||||
2585 | OperandsHider Hider; | ||||
2586 | |||||
2587 | /// Keep track of the uses replaced, if any. | ||||
2588 | UsesReplacer *Replacer = nullptr; | ||||
2589 | |||||
2590 | /// Keep track of instructions removed. | ||||
2591 | SetOfInstrs &RemovedInsts; | ||||
2592 | |||||
2593 | public: | ||||
2594 | /// Remove all reference of \p Inst and optionally replace all its | ||||
2595 | /// uses with New. | ||||
2596 | /// \p RemovedInsts Keep track of the instructions removed by this Action. | ||||
2597 | /// \pre If !Inst->use_empty(), then New != nullptr | ||||
2598 | InstructionRemover(Instruction *Inst, SetOfInstrs &RemovedInsts, | ||||
2599 | Value *New = nullptr) | ||||
2600 | : TypePromotionAction(Inst), Inserter(Inst), Hider(Inst), | ||||
2601 | RemovedInsts(RemovedInsts) { | ||||
2602 | if (New) | ||||
2603 | Replacer = new UsesReplacer(Inst, New); | ||||
2604 | LLVM_DEBUG(dbgs() << "Do: InstructionRemover: " << *Inst << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Do: InstructionRemover: " << *Inst << "\n"; } } while (false); | ||||
2605 | RemovedInsts.insert(Inst); | ||||
2606 | /// The instructions removed here will be freed after completing | ||||
2607 | /// optimizeBlock() for all blocks as we need to keep track of the | ||||
2608 | /// removed instructions during promotion. | ||||
2609 | Inst->removeFromParent(); | ||||
2610 | } | ||||
2611 | |||||
2612 | ~InstructionRemover() override { delete Replacer; } | ||||
2613 | |||||
2614 | /// Resurrect the instruction and reassign it to the proper uses if | ||||
2615 | /// new value was provided when build this action. | ||||
2616 | void undo() override { | ||||
2617 | LLVM_DEBUG(dbgs() << "Undo: InstructionRemover: " << *Inst << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Undo: InstructionRemover: " << *Inst << "\n"; } } while (false); | ||||
2618 | Inserter.insert(Inst); | ||||
2619 | if (Replacer) | ||||
2620 | Replacer->undo(); | ||||
2621 | Hider.undo(); | ||||
2622 | RemovedInsts.erase(Inst); | ||||
2623 | } | ||||
2624 | }; | ||||
2625 | |||||
2626 | public: | ||||
2627 | /// Restoration point. | ||||
2628 | /// The restoration point is a pointer to an action instead of an iterator | ||||
2629 | /// because the iterator may be invalidated but not the pointer. | ||||
2630 | using ConstRestorationPt = const TypePromotionAction *; | ||||
2631 | |||||
2632 | TypePromotionTransaction(SetOfInstrs &RemovedInsts) | ||||
2633 | : RemovedInsts(RemovedInsts) {} | ||||
2634 | |||||
2635 | /// Advocate every changes made in that transaction. | ||||
2636 | void commit(); | ||||
2637 | |||||
2638 | /// Undo all the changes made after the given point. | ||||
2639 | void rollback(ConstRestorationPt Point); | ||||
2640 | |||||
2641 | /// Get the current restoration point. | ||||
2642 | ConstRestorationPt getRestorationPoint() const; | ||||
2643 | |||||
2644 | /// \name API for IR modification with state keeping to support rollback. | ||||
2645 | /// @{ | ||||
2646 | /// Same as Instruction::setOperand. | ||||
2647 | void setOperand(Instruction *Inst, unsigned Idx, Value *NewVal); | ||||
2648 | |||||
2649 | /// Same as Instruction::eraseFromParent. | ||||
2650 | void eraseInstruction(Instruction *Inst, Value *NewVal = nullptr); | ||||
2651 | |||||
2652 | /// Same as Value::replaceAllUsesWith. | ||||
2653 | void replaceAllUsesWith(Instruction *Inst, Value *New); | ||||
2654 | |||||
2655 | /// Same as Value::mutateType. | ||||
2656 | void mutateType(Instruction *Inst, Type *NewTy); | ||||
2657 | |||||
2658 | /// Same as IRBuilder::createTrunc. | ||||
2659 | Value *createTrunc(Instruction *Opnd, Type *Ty); | ||||
2660 | |||||
2661 | /// Same as IRBuilder::createSExt. | ||||
2662 | Value *createSExt(Instruction *Inst, Value *Opnd, Type *Ty); | ||||
2663 | |||||
2664 | /// Same as IRBuilder::createZExt. | ||||
2665 | Value *createZExt(Instruction *Inst, Value *Opnd, Type *Ty); | ||||
2666 | |||||
2667 | /// Same as Instruction::moveBefore. | ||||
2668 | void moveBefore(Instruction *Inst, Instruction *Before); | ||||
2669 | /// @} | ||||
2670 | |||||
2671 | private: | ||||
2672 | /// The ordered list of actions made so far. | ||||
2673 | SmallVector<std::unique_ptr<TypePromotionAction>, 16> Actions; | ||||
2674 | |||||
2675 | using CommitPt = SmallVectorImpl<std::unique_ptr<TypePromotionAction>>::iterator; | ||||
2676 | |||||
2677 | SetOfInstrs &RemovedInsts; | ||||
2678 | }; | ||||
2679 | |||||
2680 | } // end anonymous namespace | ||||
2681 | |||||
2682 | void TypePromotionTransaction::setOperand(Instruction *Inst, unsigned Idx, | ||||
2683 | Value *NewVal) { | ||||
2684 | Actions.push_back(std::make_unique<TypePromotionTransaction::OperandSetter>( | ||||
2685 | Inst, Idx, NewVal)); | ||||
2686 | } | ||||
2687 | |||||
2688 | void TypePromotionTransaction::eraseInstruction(Instruction *Inst, | ||||
2689 | Value *NewVal) { | ||||
2690 | Actions.push_back( | ||||
2691 | std::make_unique<TypePromotionTransaction::InstructionRemover>( | ||||
2692 | Inst, RemovedInsts, NewVal)); | ||||
2693 | } | ||||
2694 | |||||
2695 | void TypePromotionTransaction::replaceAllUsesWith(Instruction *Inst, | ||||
2696 | Value *New) { | ||||
2697 | Actions.push_back( | ||||
2698 | std::make_unique<TypePromotionTransaction::UsesReplacer>(Inst, New)); | ||||
2699 | } | ||||
2700 | |||||
2701 | void TypePromotionTransaction::mutateType(Instruction *Inst, Type *NewTy) { | ||||
2702 | Actions.push_back( | ||||
2703 | std::make_unique<TypePromotionTransaction::TypeMutator>(Inst, NewTy)); | ||||
2704 | } | ||||
2705 | |||||
2706 | Value *TypePromotionTransaction::createTrunc(Instruction *Opnd, | ||||
2707 | Type *Ty) { | ||||
2708 | std::unique_ptr<TruncBuilder> Ptr(new TruncBuilder(Opnd, Ty)); | ||||
2709 | Value *Val = Ptr->getBuiltValue(); | ||||
2710 | Actions.push_back(std::move(Ptr)); | ||||
2711 | return Val; | ||||
2712 | } | ||||
2713 | |||||
2714 | Value *TypePromotionTransaction::createSExt(Instruction *Inst, | ||||
2715 | Value *Opnd, Type *Ty) { | ||||
2716 | std::unique_ptr<SExtBuilder> Ptr(new SExtBuilder(Inst, Opnd, Ty)); | ||||
2717 | Value *Val = Ptr->getBuiltValue(); | ||||
2718 | Actions.push_back(std::move(Ptr)); | ||||
2719 | return Val; | ||||
2720 | } | ||||
2721 | |||||
2722 | Value *TypePromotionTransaction::createZExt(Instruction *Inst, | ||||
2723 | Value *Opnd, Type *Ty) { | ||||
2724 | std::unique_ptr<ZExtBuilder> Ptr(new ZExtBuilder(Inst, Opnd, Ty)); | ||||
2725 | Value *Val = Ptr->getBuiltValue(); | ||||
2726 | Actions.push_back(std::move(Ptr)); | ||||
2727 | return Val; | ||||
2728 | } | ||||
2729 | |||||
2730 | void TypePromotionTransaction::moveBefore(Instruction *Inst, | ||||
2731 | Instruction *Before) { | ||||
2732 | Actions.push_back( | ||||
2733 | std::make_unique<TypePromotionTransaction::InstructionMoveBefore>( | ||||
2734 | Inst, Before)); | ||||
2735 | } | ||||
2736 | |||||
2737 | TypePromotionTransaction::ConstRestorationPt | ||||
2738 | TypePromotionTransaction::getRestorationPoint() const { | ||||
2739 | return !Actions.empty() ? Actions.back().get() : nullptr; | ||||
2740 | } | ||||
2741 | |||||
2742 | void TypePromotionTransaction::commit() { | ||||
2743 | for (CommitPt It = Actions.begin(), EndIt = Actions.end(); It != EndIt; | ||||
2744 | ++It) | ||||
2745 | (*It)->commit(); | ||||
2746 | Actions.clear(); | ||||
2747 | } | ||||
2748 | |||||
2749 | void TypePromotionTransaction::rollback( | ||||
2750 | TypePromotionTransaction::ConstRestorationPt Point) { | ||||
2751 | while (!Actions.empty() && Point != Actions.back().get()) { | ||||
2752 | std::unique_ptr<TypePromotionAction> Curr = Actions.pop_back_val(); | ||||
2753 | Curr->undo(); | ||||
2754 | } | ||||
2755 | } | ||||
2756 | |||||
2757 | namespace { | ||||
2758 | |||||
2759 | /// A helper class for matching addressing modes. | ||||
2760 | /// | ||||
2761 | /// This encapsulates the logic for matching the target-legal addressing modes. | ||||
2762 | class AddressingModeMatcher { | ||||
2763 | SmallVectorImpl<Instruction*> &AddrModeInsts; | ||||
2764 | const TargetLowering &TLI; | ||||
2765 | const TargetRegisterInfo &TRI; | ||||
2766 | const DataLayout &DL; | ||||
2767 | |||||
2768 | /// AccessTy/MemoryInst - This is the type for the access (e.g. double) and | ||||
2769 | /// the memory instruction that we're computing this address for. | ||||
2770 | Type *AccessTy; | ||||
2771 | unsigned AddrSpace; | ||||
2772 | Instruction *MemoryInst; | ||||
2773 | |||||
2774 | /// This is the addressing mode that we're building up. This is | ||||
2775 | /// part of the return value of this addressing mode matching stuff. | ||||
2776 | ExtAddrMode &AddrMode; | ||||
2777 | |||||
2778 | /// The instructions inserted by other CodeGenPrepare optimizations. | ||||
2779 | const SetOfInstrs &InsertedInsts; | ||||
2780 | |||||
2781 | /// A map from the instructions to their type before promotion. | ||||
2782 | InstrToOrigTy &PromotedInsts; | ||||
2783 | |||||
2784 | /// The ongoing transaction where every action should be registered. | ||||
2785 | TypePromotionTransaction &TPT; | ||||
2786 | |||||
2787 | // A GEP which has too large offset to be folded into the addressing mode. | ||||
2788 | std::pair<AssertingVH<GetElementPtrInst>, int64_t> &LargeOffsetGEP; | ||||
2789 | |||||
2790 | /// This is set to true when we should not do profitability checks. | ||||
2791 | /// When true, IsProfitableToFoldIntoAddressingMode always returns true. | ||||
2792 | bool IgnoreProfitability; | ||||
2793 | |||||
2794 | AddressingModeMatcher( | ||||
2795 | SmallVectorImpl<Instruction *> &AMI, const TargetLowering &TLI, | ||||
2796 | const TargetRegisterInfo &TRI, Type *AT, unsigned AS, Instruction *MI, | ||||
2797 | ExtAddrMode &AM, const SetOfInstrs &InsertedInsts, | ||||
2798 | InstrToOrigTy &PromotedInsts, TypePromotionTransaction &TPT, | ||||
2799 | std::pair<AssertingVH<GetElementPtrInst>, int64_t> &LargeOffsetGEP) | ||||
2800 | : AddrModeInsts(AMI), TLI(TLI), TRI(TRI), | ||||
2801 | DL(MI->getModule()->getDataLayout()), AccessTy(AT), AddrSpace(AS), | ||||
2802 | MemoryInst(MI), AddrMode(AM), InsertedInsts(InsertedInsts), | ||||
2803 | PromotedInsts(PromotedInsts), TPT(TPT), LargeOffsetGEP(LargeOffsetGEP) { | ||||
2804 | IgnoreProfitability = false; | ||||
2805 | } | ||||
2806 | |||||
2807 | public: | ||||
2808 | /// Find the maximal addressing mode that a load/store of V can fold, | ||||
2809 | /// give an access type of AccessTy. This returns a list of involved | ||||
2810 | /// instructions in AddrModeInsts. | ||||
2811 | /// \p InsertedInsts The instructions inserted by other CodeGenPrepare | ||||
2812 | /// optimizations. | ||||
2813 | /// \p PromotedInsts maps the instructions to their type before promotion. | ||||
2814 | /// \p The ongoing transaction where every action should be registered. | ||||
2815 | static ExtAddrMode | ||||
2816 | Match(Value *V, Type *AccessTy, unsigned AS, Instruction *MemoryInst, | ||||
2817 | SmallVectorImpl<Instruction *> &AddrModeInsts, | ||||
2818 | const TargetLowering &TLI, const TargetRegisterInfo &TRI, | ||||
2819 | const SetOfInstrs &InsertedInsts, InstrToOrigTy &PromotedInsts, | ||||
2820 | TypePromotionTransaction &TPT, | ||||
2821 | std::pair<AssertingVH<GetElementPtrInst>, int64_t> &LargeOffsetGEP) { | ||||
2822 | ExtAddrMode Result; | ||||
2823 | |||||
2824 | bool Success = AddressingModeMatcher(AddrModeInsts, TLI, TRI, AccessTy, AS, | ||||
2825 | MemoryInst, Result, InsertedInsts, | ||||
2826 | PromotedInsts, TPT, LargeOffsetGEP) | ||||
2827 | .matchAddr(V, 0); | ||||
2828 | (void)Success; assert(Success && "Couldn't select *anything*?")((Success && "Couldn't select *anything*?") ? static_cast <void> (0) : __assert_fail ("Success && \"Couldn't select *anything*?\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 2828, __PRETTY_FUNCTION__)); | ||||
2829 | return Result; | ||||
2830 | } | ||||
2831 | |||||
2832 | private: | ||||
2833 | bool matchScaledValue(Value *ScaleReg, int64_t Scale, unsigned Depth); | ||||
2834 | bool matchAddr(Value *Addr, unsigned Depth); | ||||
2835 | bool matchOperationAddr(User *AddrInst, unsigned Opcode, unsigned Depth, | ||||
2836 | bool *MovedAway = nullptr); | ||||
2837 | bool isProfitableToFoldIntoAddressingMode(Instruction *I, | ||||
2838 | ExtAddrMode &AMBefore, | ||||
2839 | ExtAddrMode &AMAfter); | ||||
2840 | bool valueAlreadyLiveAtInst(Value *Val, Value *KnownLive1, Value *KnownLive2); | ||||
2841 | bool isPromotionProfitable(unsigned NewCost, unsigned OldCost, | ||||
2842 | Value *PromotedOperand) const; | ||||
2843 | }; | ||||
2844 | |||||
2845 | class PhiNodeSet; | ||||
2846 | |||||
2847 | /// An iterator for PhiNodeSet. | ||||
2848 | class PhiNodeSetIterator { | ||||
2849 | PhiNodeSet * const Set; | ||||
2850 | size_t CurrentIndex = 0; | ||||
2851 | |||||
2852 | public: | ||||
2853 | /// The constructor. Start should point to either a valid element, or be equal | ||||
2854 | /// to the size of the underlying SmallVector of the PhiNodeSet. | ||||
2855 | PhiNodeSetIterator(PhiNodeSet * const Set, size_t Start); | ||||
2856 | PHINode * operator*() const; | ||||
2857 | PhiNodeSetIterator& operator++(); | ||||
2858 | bool operator==(const PhiNodeSetIterator &RHS) const; | ||||
2859 | bool operator!=(const PhiNodeSetIterator &RHS) const; | ||||
2860 | }; | ||||
2861 | |||||
2862 | /// Keeps a set of PHINodes. | ||||
2863 | /// | ||||
2864 | /// This is a minimal set implementation for a specific use case: | ||||
2865 | /// It is very fast when there are very few elements, but also provides good | ||||
2866 | /// performance when there are many. It is similar to SmallPtrSet, but also | ||||
2867 | /// provides iteration by insertion order, which is deterministic and stable | ||||
2868 | /// across runs. It is also similar to SmallSetVector, but provides removing | ||||
2869 | /// elements in O(1) time. This is achieved by not actually removing the element | ||||
2870 | /// from the underlying vector, so comes at the cost of using more memory, but | ||||
2871 | /// that is fine, since PhiNodeSets are used as short lived objects. | ||||
2872 | class PhiNodeSet { | ||||
2873 | friend class PhiNodeSetIterator; | ||||
2874 | |||||
2875 | using MapType = SmallDenseMap<PHINode *, size_t, 32>; | ||||
2876 | using iterator = PhiNodeSetIterator; | ||||
2877 | |||||
2878 | /// Keeps the elements in the order of their insertion in the underlying | ||||
2879 | /// vector. To achieve constant time removal, it never deletes any element. | ||||
2880 | SmallVector<PHINode *, 32> NodeList; | ||||
2881 | |||||
2882 | /// Keeps the elements in the underlying set implementation. This (and not the | ||||
2883 | /// NodeList defined above) is the source of truth on whether an element | ||||
2884 | /// is actually in the collection. | ||||
2885 | MapType NodeMap; | ||||
2886 | |||||
2887 | /// Points to the first valid (not deleted) element when the set is not empty | ||||
2888 | /// and the value is not zero. Equals to the size of the underlying vector | ||||
2889 | /// when the set is empty. When the value is 0, as in the beginning, the | ||||
2890 | /// first element may or may not be valid. | ||||
2891 | size_t FirstValidElement = 0; | ||||
2892 | |||||
2893 | public: | ||||
2894 | /// Inserts a new element to the collection. | ||||
2895 | /// \returns true if the element is actually added, i.e. was not in the | ||||
2896 | /// collection before the operation. | ||||
2897 | bool insert(PHINode *Ptr) { | ||||
2898 | if (NodeMap.insert(std::make_pair(Ptr, NodeList.size())).second) { | ||||
2899 | NodeList.push_back(Ptr); | ||||
2900 | return true; | ||||
2901 | } | ||||
2902 | return false; | ||||
2903 | } | ||||
2904 | |||||
2905 | /// Removes the element from the collection. | ||||
2906 | /// \returns whether the element is actually removed, i.e. was in the | ||||
2907 | /// collection before the operation. | ||||
2908 | bool erase(PHINode *Ptr) { | ||||
2909 | auto it = NodeMap.find(Ptr); | ||||
2910 | if (it != NodeMap.end()) { | ||||
2911 | NodeMap.erase(Ptr); | ||||
2912 | SkipRemovedElements(FirstValidElement); | ||||
2913 | return true; | ||||
2914 | } | ||||
2915 | return false; | ||||
2916 | } | ||||
2917 | |||||
2918 | /// Removes all elements and clears the collection. | ||||
2919 | void clear() { | ||||
2920 | NodeMap.clear(); | ||||
2921 | NodeList.clear(); | ||||
2922 | FirstValidElement = 0; | ||||
2923 | } | ||||
2924 | |||||
2925 | /// \returns an iterator that will iterate the elements in the order of | ||||
2926 | /// insertion. | ||||
2927 | iterator begin() { | ||||
2928 | if (FirstValidElement == 0) | ||||
2929 | SkipRemovedElements(FirstValidElement); | ||||
2930 | return PhiNodeSetIterator(this, FirstValidElement); | ||||
2931 | } | ||||
2932 | |||||
2933 | /// \returns an iterator that points to the end of the collection. | ||||
2934 | iterator end() { return PhiNodeSetIterator(this, NodeList.size()); } | ||||
2935 | |||||
2936 | /// Returns the number of elements in the collection. | ||||
2937 | size_t size() const { | ||||
2938 | return NodeMap.size(); | ||||
2939 | } | ||||
2940 | |||||
2941 | /// \returns 1 if the given element is in the collection, and 0 if otherwise. | ||||
2942 | size_t count(PHINode *Ptr) const { | ||||
2943 | return NodeMap.count(Ptr); | ||||
2944 | } | ||||
2945 | |||||
2946 | private: | ||||
2947 | /// Updates the CurrentIndex so that it will point to a valid element. | ||||
2948 | /// | ||||
2949 | /// If the element of NodeList at CurrentIndex is valid, it does not | ||||
2950 | /// change it. If there are no more valid elements, it updates CurrentIndex | ||||
2951 | /// to point to the end of the NodeList. | ||||
2952 | void SkipRemovedElements(size_t &CurrentIndex) { | ||||
2953 | while (CurrentIndex < NodeList.size()) { | ||||
2954 | auto it = NodeMap.find(NodeList[CurrentIndex]); | ||||
2955 | // If the element has been deleted and added again later, NodeMap will | ||||
2956 | // point to a different index, so CurrentIndex will still be invalid. | ||||
2957 | if (it != NodeMap.end() && it->second == CurrentIndex) | ||||
2958 | break; | ||||
2959 | ++CurrentIndex; | ||||
2960 | } | ||||
2961 | } | ||||
2962 | }; | ||||
2963 | |||||
2964 | PhiNodeSetIterator::PhiNodeSetIterator(PhiNodeSet *const Set, size_t Start) | ||||
2965 | : Set(Set), CurrentIndex(Start) {} | ||||
2966 | |||||
2967 | PHINode * PhiNodeSetIterator::operator*() const { | ||||
2968 | assert(CurrentIndex < Set->NodeList.size() &&((CurrentIndex < Set->NodeList.size() && "PhiNodeSet access out of range" ) ? static_cast<void> (0) : __assert_fail ("CurrentIndex < Set->NodeList.size() && \"PhiNodeSet access out of range\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 2969, __PRETTY_FUNCTION__)) | ||||
2969 | "PhiNodeSet access out of range")((CurrentIndex < Set->NodeList.size() && "PhiNodeSet access out of range" ) ? static_cast<void> (0) : __assert_fail ("CurrentIndex < Set->NodeList.size() && \"PhiNodeSet access out of range\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 2969, __PRETTY_FUNCTION__)); | ||||
2970 | return Set->NodeList[CurrentIndex]; | ||||
2971 | } | ||||
2972 | |||||
2973 | PhiNodeSetIterator& PhiNodeSetIterator::operator++() { | ||||
2974 | assert(CurrentIndex < Set->NodeList.size() &&((CurrentIndex < Set->NodeList.size() && "PhiNodeSet access out of range" ) ? static_cast<void> (0) : __assert_fail ("CurrentIndex < Set->NodeList.size() && \"PhiNodeSet access out of range\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 2975, __PRETTY_FUNCTION__)) | ||||
2975 | "PhiNodeSet access out of range")((CurrentIndex < Set->NodeList.size() && "PhiNodeSet access out of range" ) ? static_cast<void> (0) : __assert_fail ("CurrentIndex < Set->NodeList.size() && \"PhiNodeSet access out of range\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 2975, __PRETTY_FUNCTION__)); | ||||
2976 | ++CurrentIndex; | ||||
2977 | Set->SkipRemovedElements(CurrentIndex); | ||||
2978 | return *this; | ||||
2979 | } | ||||
2980 | |||||
2981 | bool PhiNodeSetIterator::operator==(const PhiNodeSetIterator &RHS) const { | ||||
2982 | return CurrentIndex == RHS.CurrentIndex; | ||||
2983 | } | ||||
2984 | |||||
2985 | bool PhiNodeSetIterator::operator!=(const PhiNodeSetIterator &RHS) const { | ||||
2986 | return !((*this) == RHS); | ||||
2987 | } | ||||
2988 | |||||
2989 | /// Keep track of simplification of Phi nodes. | ||||
2990 | /// Accept the set of all phi nodes and erase phi node from this set | ||||
2991 | /// if it is simplified. | ||||
2992 | class SimplificationTracker { | ||||
2993 | DenseMap<Value *, Value *> Storage; | ||||
2994 | const SimplifyQuery &SQ; | ||||
2995 | // Tracks newly created Phi nodes. The elements are iterated by insertion | ||||
2996 | // order. | ||||
2997 | PhiNodeSet AllPhiNodes; | ||||
2998 | // Tracks newly created Select nodes. | ||||
2999 | SmallPtrSet<SelectInst *, 32> AllSelectNodes; | ||||
3000 | |||||
3001 | public: | ||||
3002 | SimplificationTracker(const SimplifyQuery &sq) | ||||
3003 | : SQ(sq) {} | ||||
3004 | |||||
3005 | Value *Get(Value *V) { | ||||
3006 | do { | ||||
3007 | auto SV = Storage.find(V); | ||||
3008 | if (SV == Storage.end()) | ||||
3009 | return V; | ||||
3010 | V = SV->second; | ||||
3011 | } while (true); | ||||
3012 | } | ||||
3013 | |||||
3014 | Value *Simplify(Value *Val) { | ||||
3015 | SmallVector<Value *, 32> WorkList; | ||||
3016 | SmallPtrSet<Value *, 32> Visited; | ||||
3017 | WorkList.push_back(Val); | ||||
3018 | while (!WorkList.empty()) { | ||||
3019 | auto P = WorkList.pop_back_val(); | ||||
3020 | if (!Visited.insert(P).second) | ||||
3021 | continue; | ||||
3022 | if (auto *PI = dyn_cast<Instruction>(P)) | ||||
3023 | if (Value *V = SimplifyInstruction(cast<Instruction>(PI), SQ)) { | ||||
3024 | for (auto *U : PI->users()) | ||||
3025 | WorkList.push_back(cast<Value>(U)); | ||||
3026 | Put(PI, V); | ||||
3027 | PI->replaceAllUsesWith(V); | ||||
3028 | if (auto *PHI = dyn_cast<PHINode>(PI)) | ||||
3029 | AllPhiNodes.erase(PHI); | ||||
3030 | if (auto *Select = dyn_cast<SelectInst>(PI)) | ||||
3031 | AllSelectNodes.erase(Select); | ||||
3032 | PI->eraseFromParent(); | ||||
3033 | } | ||||
3034 | } | ||||
3035 | return Get(Val); | ||||
3036 | } | ||||
3037 | |||||
3038 | void Put(Value *From, Value *To) { | ||||
3039 | Storage.insert({ From, To }); | ||||
3040 | } | ||||
3041 | |||||
3042 | void ReplacePhi(PHINode *From, PHINode *To) { | ||||
3043 | Value* OldReplacement = Get(From); | ||||
3044 | while (OldReplacement != From) { | ||||
3045 | From = To; | ||||
3046 | To = dyn_cast<PHINode>(OldReplacement); | ||||
3047 | OldReplacement = Get(From); | ||||
3048 | } | ||||
3049 | assert(Get(To) == To && "Replacement PHI node is already replaced.")((Get(To) == To && "Replacement PHI node is already replaced." ) ? static_cast<void> (0) : __assert_fail ("Get(To) == To && \"Replacement PHI node is already replaced.\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 3049, __PRETTY_FUNCTION__)); | ||||
3050 | Put(From, To); | ||||
3051 | From->replaceAllUsesWith(To); | ||||
3052 | AllPhiNodes.erase(From); | ||||
3053 | From->eraseFromParent(); | ||||
3054 | } | ||||
3055 | |||||
3056 | PhiNodeSet& newPhiNodes() { return AllPhiNodes; } | ||||
3057 | |||||
3058 | void insertNewPhi(PHINode *PN) { AllPhiNodes.insert(PN); } | ||||
3059 | |||||
3060 | void insertNewSelect(SelectInst *SI) { AllSelectNodes.insert(SI); } | ||||
3061 | |||||
3062 | unsigned countNewPhiNodes() const { return AllPhiNodes.size(); } | ||||
3063 | |||||
3064 | unsigned countNewSelectNodes() const { return AllSelectNodes.size(); } | ||||
3065 | |||||
3066 | void destroyNewNodes(Type *CommonType) { | ||||
3067 | // For safe erasing, replace the uses with dummy value first. | ||||
3068 | auto Dummy = UndefValue::get(CommonType); | ||||
3069 | for (auto I : AllPhiNodes) { | ||||
3070 | I->replaceAllUsesWith(Dummy); | ||||
3071 | I->eraseFromParent(); | ||||
3072 | } | ||||
3073 | AllPhiNodes.clear(); | ||||
3074 | for (auto I : AllSelectNodes) { | ||||
3075 | I->replaceAllUsesWith(Dummy); | ||||
3076 | I->eraseFromParent(); | ||||
3077 | } | ||||
3078 | AllSelectNodes.clear(); | ||||
3079 | } | ||||
3080 | }; | ||||
3081 | |||||
3082 | /// A helper class for combining addressing modes. | ||||
3083 | class AddressingModeCombiner { | ||||
3084 | typedef DenseMap<Value *, Value *> FoldAddrToValueMapping; | ||||
3085 | typedef std::pair<PHINode *, PHINode *> PHIPair; | ||||
3086 | |||||
3087 | private: | ||||
3088 | /// The addressing modes we've collected. | ||||
3089 | SmallVector<ExtAddrMode, 16> AddrModes; | ||||
3090 | |||||
3091 | /// The field in which the AddrModes differ, when we have more than one. | ||||
3092 | ExtAddrMode::FieldName DifferentField = ExtAddrMode::NoField; | ||||
3093 | |||||
3094 | /// Are the AddrModes that we have all just equal to their original values? | ||||
3095 | bool AllAddrModesTrivial = true; | ||||
3096 | |||||
3097 | /// Common Type for all different fields in addressing modes. | ||||
3098 | Type *CommonType; | ||||
3099 | |||||
3100 | /// SimplifyQuery for simplifyInstruction utility. | ||||
3101 | const SimplifyQuery &SQ; | ||||
3102 | |||||
3103 | /// Original Address. | ||||
3104 | Value *Original; | ||||
3105 | |||||
3106 | public: | ||||
3107 | AddressingModeCombiner(const SimplifyQuery &_SQ, Value *OriginalValue) | ||||
3108 | : CommonType(nullptr), SQ(_SQ), Original(OriginalValue) {} | ||||
3109 | |||||
3110 | /// Get the combined AddrMode | ||||
3111 | const ExtAddrMode &getAddrMode() const { | ||||
3112 | return AddrModes[0]; | ||||
3113 | } | ||||
3114 | |||||
3115 | /// Add a new AddrMode if it's compatible with the AddrModes we already | ||||
3116 | /// have. | ||||
3117 | /// \return True iff we succeeded in doing so. | ||||
3118 | bool addNewAddrMode(ExtAddrMode &NewAddrMode) { | ||||
3119 | // Take note of if we have any non-trivial AddrModes, as we need to detect | ||||
3120 | // when all AddrModes are trivial as then we would introduce a phi or select | ||||
3121 | // which just duplicates what's already there. | ||||
3122 | AllAddrModesTrivial = AllAddrModesTrivial && NewAddrMode.isTrivial(); | ||||
3123 | |||||
3124 | // If this is the first addrmode then everything is fine. | ||||
3125 | if (AddrModes.empty()) { | ||||
3126 | AddrModes.emplace_back(NewAddrMode); | ||||
3127 | return true; | ||||
3128 | } | ||||
3129 | |||||
3130 | // Figure out how different this is from the other address modes, which we | ||||
3131 | // can do just by comparing against the first one given that we only care | ||||
3132 | // about the cumulative difference. | ||||
3133 | ExtAddrMode::FieldName ThisDifferentField = | ||||
3134 | AddrModes[0].compare(NewAddrMode); | ||||
3135 | if (DifferentField == ExtAddrMode::NoField) | ||||
3136 | DifferentField = ThisDifferentField; | ||||
3137 | else if (DifferentField != ThisDifferentField) | ||||
3138 | DifferentField = ExtAddrMode::MultipleFields; | ||||
3139 | |||||
3140 | // If NewAddrMode differs in more than one dimension we cannot handle it. | ||||
3141 | bool CanHandle = DifferentField != ExtAddrMode::MultipleFields; | ||||
3142 | |||||
3143 | // If Scale Field is different then we reject. | ||||
3144 | CanHandle = CanHandle && DifferentField != ExtAddrMode::ScaleField; | ||||
3145 | |||||
3146 | // We also must reject the case when base offset is different and | ||||
3147 | // scale reg is not null, we cannot handle this case due to merge of | ||||
3148 | // different offsets will be used as ScaleReg. | ||||
3149 | CanHandle = CanHandle && (DifferentField != ExtAddrMode::BaseOffsField || | ||||
3150 | !NewAddrMode.ScaledReg); | ||||
3151 | |||||
3152 | // We also must reject the case when GV is different and BaseReg installed | ||||
3153 | // due to we want to use base reg as a merge of GV values. | ||||
3154 | CanHandle = CanHandle && (DifferentField != ExtAddrMode::BaseGVField || | ||||
3155 | !NewAddrMode.HasBaseReg); | ||||
3156 | |||||
3157 | // Even if NewAddMode is the same we still need to collect it due to | ||||
3158 | // original value is different. And later we will need all original values | ||||
3159 | // as anchors during finding the common Phi node. | ||||
3160 | if (CanHandle) | ||||
3161 | AddrModes.emplace_back(NewAddrMode); | ||||
3162 | else | ||||
3163 | AddrModes.clear(); | ||||
3164 | |||||
3165 | return CanHandle; | ||||
3166 | } | ||||
3167 | |||||
3168 | /// Combine the addressing modes we've collected into a single | ||||
3169 | /// addressing mode. | ||||
3170 | /// \return True iff we successfully combined them or we only had one so | ||||
3171 | /// didn't need to combine them anyway. | ||||
3172 | bool combineAddrModes() { | ||||
3173 | // If we have no AddrModes then they can't be combined. | ||||
3174 | if (AddrModes.size() == 0) | ||||
3175 | return false; | ||||
3176 | |||||
3177 | // A single AddrMode can trivially be combined. | ||||
3178 | if (AddrModes.size() == 1 || DifferentField == ExtAddrMode::NoField) | ||||
3179 | return true; | ||||
3180 | |||||
3181 | // If the AddrModes we collected are all just equal to the value they are | ||||
3182 | // derived from then combining them wouldn't do anything useful. | ||||
3183 | if (AllAddrModesTrivial) | ||||
3184 | return false; | ||||
3185 | |||||
3186 | if (!addrModeCombiningAllowed()) | ||||
3187 | return false; | ||||
3188 | |||||
3189 | // Build a map between <original value, basic block where we saw it> to | ||||
3190 | // value of base register. | ||||
3191 | // Bail out if there is no common type. | ||||
3192 | FoldAddrToValueMapping Map; | ||||
3193 | if (!initializeMap(Map)) | ||||
3194 | return false; | ||||
3195 | |||||
3196 | Value *CommonValue = findCommon(Map); | ||||
3197 | if (CommonValue) | ||||
3198 | AddrModes[0].SetCombinedField(DifferentField, CommonValue, AddrModes); | ||||
3199 | return CommonValue != nullptr; | ||||
3200 | } | ||||
3201 | |||||
3202 | private: | ||||
3203 | /// Initialize Map with anchor values. For address seen | ||||
3204 | /// we set the value of different field saw in this address. | ||||
3205 | /// At the same time we find a common type for different field we will | ||||
3206 | /// use to create new Phi/Select nodes. Keep it in CommonType field. | ||||
3207 | /// Return false if there is no common type found. | ||||
3208 | bool initializeMap(FoldAddrToValueMapping &Map) { | ||||
3209 | // Keep track of keys where the value is null. We will need to replace it | ||||
3210 | // with constant null when we know the common type. | ||||
3211 | SmallVector<Value *, 2> NullValue; | ||||
3212 | Type *IntPtrTy = SQ.DL.getIntPtrType(AddrModes[0].OriginalValue->getType()); | ||||
3213 | for (auto &AM : AddrModes) { | ||||
3214 | Value *DV = AM.GetFieldAsValue(DifferentField, IntPtrTy); | ||||
3215 | if (DV) { | ||||
3216 | auto *Type = DV->getType(); | ||||
3217 | if (CommonType && CommonType != Type) | ||||
3218 | return false; | ||||
3219 | CommonType = Type; | ||||
3220 | Map[AM.OriginalValue] = DV; | ||||
3221 | } else { | ||||
3222 | NullValue.push_back(AM.OriginalValue); | ||||
3223 | } | ||||
3224 | } | ||||
3225 | assert(CommonType && "At least one non-null value must be!")((CommonType && "At least one non-null value must be!" ) ? static_cast<void> (0) : __assert_fail ("CommonType && \"At least one non-null value must be!\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 3225, __PRETTY_FUNCTION__)); | ||||
3226 | for (auto *V : NullValue) | ||||
3227 | Map[V] = Constant::getNullValue(CommonType); | ||||
3228 | return true; | ||||
3229 | } | ||||
3230 | |||||
3231 | /// We have mapping between value A and other value B where B was a field in | ||||
3232 | /// addressing mode represented by A. Also we have an original value C | ||||
3233 | /// representing an address we start with. Traversing from C through phi and | ||||
3234 | /// selects we ended up with A's in a map. This utility function tries to find | ||||
3235 | /// a value V which is a field in addressing mode C and traversing through phi | ||||
3236 | /// nodes and selects we will end up in corresponded values B in a map. | ||||
3237 | /// The utility will create a new Phi/Selects if needed. | ||||
3238 | // The simple example looks as follows: | ||||
3239 | // BB1: | ||||
3240 | // p1 = b1 + 40 | ||||
3241 | // br cond BB2, BB3 | ||||
3242 | // BB2: | ||||
3243 | // p2 = b2 + 40 | ||||
3244 | // br BB3 | ||||
3245 | // BB3: | ||||
3246 | // p = phi [p1, BB1], [p2, BB2] | ||||
3247 | // v = load p | ||||
3248 | // Map is | ||||
3249 | // p1 -> b1 | ||||
3250 | // p2 -> b2 | ||||
3251 | // Request is | ||||
3252 | // p -> ? | ||||
3253 | // The function tries to find or build phi [b1, BB1], [b2, BB2] in BB3. | ||||
3254 | Value *findCommon(FoldAddrToValueMapping &Map) { | ||||
3255 | // Tracks the simplification of newly created phi nodes. The reason we use | ||||
3256 | // this mapping is because we will add new created Phi nodes in AddrToBase. | ||||
3257 | // Simplification of Phi nodes is recursive, so some Phi node may | ||||
3258 | // be simplified after we added it to AddrToBase. In reality this | ||||
3259 | // simplification is possible only if original phi/selects were not | ||||
3260 | // simplified yet. | ||||
3261 | // Using this mapping we can find the current value in AddrToBase. | ||||
3262 | SimplificationTracker ST(SQ); | ||||
3263 | |||||
3264 | // First step, DFS to create PHI nodes for all intermediate blocks. | ||||
3265 | // Also fill traverse order for the second step. | ||||
3266 | SmallVector<Value *, 32> TraverseOrder; | ||||
3267 | InsertPlaceholders(Map, TraverseOrder, ST); | ||||
3268 | |||||
3269 | // Second Step, fill new nodes by merged values and simplify if possible. | ||||
3270 | FillPlaceholders(Map, TraverseOrder, ST); | ||||
3271 | |||||
3272 | if (!AddrSinkNewSelects && ST.countNewSelectNodes() > 0) { | ||||
3273 | ST.destroyNewNodes(CommonType); | ||||
3274 | return nullptr; | ||||
3275 | } | ||||
3276 | |||||
3277 | // Now we'd like to match New Phi nodes to existed ones. | ||||
3278 | unsigned PhiNotMatchedCount = 0; | ||||
3279 | if (!MatchPhiSet(ST, AddrSinkNewPhis, PhiNotMatchedCount)) { | ||||
3280 | ST.destroyNewNodes(CommonType); | ||||
3281 | return nullptr; | ||||
3282 | } | ||||
3283 | |||||
3284 | auto *Result = ST.Get(Map.find(Original)->second); | ||||
3285 | if (Result) { | ||||
3286 | NumMemoryInstsPhiCreated += ST.countNewPhiNodes() + PhiNotMatchedCount; | ||||
3287 | NumMemoryInstsSelectCreated += ST.countNewSelectNodes(); | ||||
3288 | } | ||||
3289 | return Result; | ||||
3290 | } | ||||
3291 | |||||
3292 | /// Try to match PHI node to Candidate. | ||||
3293 | /// Matcher tracks the matched Phi nodes. | ||||
3294 | bool MatchPhiNode(PHINode *PHI, PHINode *Candidate, | ||||
3295 | SmallSetVector<PHIPair, 8> &Matcher, | ||||
3296 | PhiNodeSet &PhiNodesToMatch) { | ||||
3297 | SmallVector<PHIPair, 8> WorkList; | ||||
3298 | Matcher.insert({ PHI, Candidate }); | ||||
3299 | SmallSet<PHINode *, 8> MatchedPHIs; | ||||
3300 | MatchedPHIs.insert(PHI); | ||||
3301 | WorkList.push_back({ PHI, Candidate }); | ||||
3302 | SmallSet<PHIPair, 8> Visited; | ||||
3303 | while (!WorkList.empty()) { | ||||
3304 | auto Item = WorkList.pop_back_val(); | ||||
3305 | if (!Visited.insert(Item).second) | ||||
3306 | continue; | ||||
3307 | // We iterate over all incoming values to Phi to compare them. | ||||
3308 | // If values are different and both of them Phi and the first one is a | ||||
3309 | // Phi we added (subject to match) and both of them is in the same basic | ||||
3310 | // block then we can match our pair if values match. So we state that | ||||
3311 | // these values match and add it to work list to verify that. | ||||
3312 | for (auto B : Item.first->blocks()) { | ||||
3313 | Value *FirstValue = Item.first->getIncomingValueForBlock(B); | ||||
3314 | Value *SecondValue = Item.second->getIncomingValueForBlock(B); | ||||
3315 | if (FirstValue == SecondValue) | ||||
3316 | continue; | ||||
3317 | |||||
3318 | PHINode *FirstPhi = dyn_cast<PHINode>(FirstValue); | ||||
3319 | PHINode *SecondPhi = dyn_cast<PHINode>(SecondValue); | ||||
3320 | |||||
3321 | // One of them is not Phi or | ||||
3322 | // The first one is not Phi node from the set we'd like to match or | ||||
3323 | // Phi nodes from different basic blocks then | ||||
3324 | // we will not be able to match. | ||||
3325 | if (!FirstPhi || !SecondPhi || !PhiNodesToMatch.count(FirstPhi) || | ||||
3326 | FirstPhi->getParent() != SecondPhi->getParent()) | ||||
3327 | return false; | ||||
3328 | |||||
3329 | // If we already matched them then continue. | ||||
3330 | if (Matcher.count({ FirstPhi, SecondPhi })) | ||||
3331 | continue; | ||||
3332 | // So the values are different and does not match. So we need them to | ||||
3333 | // match. (But we register no more than one match per PHI node, so that | ||||
3334 | // we won't later try to replace them twice.) | ||||
3335 | if (MatchedPHIs.insert(FirstPhi).second) | ||||
3336 | Matcher.insert({ FirstPhi, SecondPhi }); | ||||
3337 | // But me must check it. | ||||
3338 | WorkList.push_back({ FirstPhi, SecondPhi }); | ||||
3339 | } | ||||
3340 | } | ||||
3341 | return true; | ||||
3342 | } | ||||
3343 | |||||
3344 | /// For the given set of PHI nodes (in the SimplificationTracker) try | ||||
3345 | /// to find their equivalents. | ||||
3346 | /// Returns false if this matching fails and creation of new Phi is disabled. | ||||
3347 | bool MatchPhiSet(SimplificationTracker &ST, bool AllowNewPhiNodes, | ||||
3348 | unsigned &PhiNotMatchedCount) { | ||||
3349 | // Matched and PhiNodesToMatch iterate their elements in a deterministic | ||||
3350 | // order, so the replacements (ReplacePhi) are also done in a deterministic | ||||
3351 | // order. | ||||
3352 | SmallSetVector<PHIPair, 8> Matched; | ||||
3353 | SmallPtrSet<PHINode *, 8> WillNotMatch; | ||||
3354 | PhiNodeSet &PhiNodesToMatch = ST.newPhiNodes(); | ||||
3355 | while (PhiNodesToMatch.size()) { | ||||
3356 | PHINode *PHI = *PhiNodesToMatch.begin(); | ||||
3357 | |||||
3358 | // Add us, if no Phi nodes in the basic block we do not match. | ||||
3359 | WillNotMatch.clear(); | ||||
3360 | WillNotMatch.insert(PHI); | ||||
3361 | |||||
3362 | // Traverse all Phis until we found equivalent or fail to do that. | ||||
3363 | bool IsMatched = false; | ||||
3364 | for (auto &P : PHI->getParent()->phis()) { | ||||
3365 | if (&P == PHI) | ||||
3366 | continue; | ||||
3367 | if ((IsMatched = MatchPhiNode(PHI, &P, Matched, PhiNodesToMatch))) | ||||
3368 | break; | ||||
3369 | // If it does not match, collect all Phi nodes from matcher. | ||||
3370 | // if we end up with no match, them all these Phi nodes will not match | ||||
3371 | // later. | ||||
3372 | for (auto M : Matched) | ||||
3373 | WillNotMatch.insert(M.first); | ||||
3374 | Matched.clear(); | ||||
3375 | } | ||||
3376 | if (IsMatched) { | ||||
3377 | // Replace all matched values and erase them. | ||||
3378 | for (auto MV : Matched) | ||||
3379 | ST.ReplacePhi(MV.first, MV.second); | ||||
3380 | Matched.clear(); | ||||
3381 | continue; | ||||
3382 | } | ||||
3383 | // If we are not allowed to create new nodes then bail out. | ||||
3384 | if (!AllowNewPhiNodes) | ||||
3385 | return false; | ||||
3386 | // Just remove all seen values in matcher. They will not match anything. | ||||
3387 | PhiNotMatchedCount += WillNotMatch.size(); | ||||
3388 | for (auto *P : WillNotMatch) | ||||
3389 | PhiNodesToMatch.erase(P); | ||||
3390 | } | ||||
3391 | return true; | ||||
3392 | } | ||||
3393 | /// Fill the placeholders with values from predecessors and simplify them. | ||||
3394 | void FillPlaceholders(FoldAddrToValueMapping &Map, | ||||
3395 | SmallVectorImpl<Value *> &TraverseOrder, | ||||
3396 | SimplificationTracker &ST) { | ||||
3397 | while (!TraverseOrder.empty()) { | ||||
3398 | Value *Current = TraverseOrder.pop_back_val(); | ||||
3399 | assert(Map.find(Current) != Map.end() && "No node to fill!!!")((Map.find(Current) != Map.end() && "No node to fill!!!" ) ? static_cast<void> (0) : __assert_fail ("Map.find(Current) != Map.end() && \"No node to fill!!!\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 3399, __PRETTY_FUNCTION__)); | ||||
3400 | Value *V = Map[Current]; | ||||
3401 | |||||
3402 | if (SelectInst *Select
| ||||
3403 | // CurrentValue also must be Select. | ||||
3404 | auto *CurrentSelect = cast<SelectInst>(Current); | ||||
3405 | auto *TrueValue = CurrentSelect->getTrueValue(); | ||||
3406 | assert(Map.find(TrueValue) != Map.end() && "No True Value!")((Map.find(TrueValue) != Map.end() && "No True Value!" ) ? static_cast<void> (0) : __assert_fail ("Map.find(TrueValue) != Map.end() && \"No True Value!\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 3406, __PRETTY_FUNCTION__)); | ||||
3407 | Select->setTrueValue(ST.Get(Map[TrueValue])); | ||||
3408 | auto *FalseValue = CurrentSelect->getFalseValue(); | ||||
3409 | assert(Map.find(FalseValue) != Map.end() && "No False Value!")((Map.find(FalseValue) != Map.end() && "No False Value!" ) ? static_cast<void> (0) : __assert_fail ("Map.find(FalseValue) != Map.end() && \"No False Value!\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 3409, __PRETTY_FUNCTION__)); | ||||
3410 | Select->setFalseValue(ST.Get(Map[FalseValue])); | ||||
3411 | } else { | ||||
3412 | // Must be a Phi node then. | ||||
3413 | PHINode *PHI = cast<PHINode>(V); | ||||
3414 | auto *CurrentPhi = dyn_cast<PHINode>(Current); | ||||
3415 | // Fill the Phi node with values from predecessors. | ||||
3416 | for (auto B : predecessors(PHI->getParent())) { | ||||
3417 | Value *PV = CurrentPhi->getIncomingValueForBlock(B); | ||||
| |||||
3418 | assert(Map.find(PV) != Map.end() && "No predecessor Value!")((Map.find(PV) != Map.end() && "No predecessor Value!" ) ? static_cast<void> (0) : __assert_fail ("Map.find(PV) != Map.end() && \"No predecessor Value!\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 3418, __PRETTY_FUNCTION__)); | ||||
3419 | PHI->addIncoming(ST.Get(Map[PV]), B); | ||||
3420 | } | ||||
3421 | } | ||||
3422 | Map[Current] = ST.Simplify(V); | ||||
3423 | } | ||||
3424 | } | ||||
3425 | |||||
3426 | /// Starting from original value recursively iterates over def-use chain up to | ||||
3427 | /// known ending values represented in a map. For each traversed phi/select | ||||
3428 | /// inserts a placeholder Phi or Select. | ||||
3429 | /// Reports all new created Phi/Select nodes by adding them to set. | ||||
3430 | /// Also reports and order in what values have been traversed. | ||||
3431 | void InsertPlaceholders(FoldAddrToValueMapping &Map, | ||||
3432 | SmallVectorImpl<Value *> &TraverseOrder, | ||||
3433 | SimplificationTracker &ST) { | ||||
3434 | SmallVector<Value *, 32> Worklist; | ||||
3435 | assert((isa<PHINode>(Original) || isa<SelectInst>(Original)) &&(((isa<PHINode>(Original) || isa<SelectInst>(Original )) && "Address must be a Phi or Select node") ? static_cast <void> (0) : __assert_fail ("(isa<PHINode>(Original) || isa<SelectInst>(Original)) && \"Address must be a Phi or Select node\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 3436, __PRETTY_FUNCTION__)) | ||||
3436 | "Address must be a Phi or Select node")(((isa<PHINode>(Original) || isa<SelectInst>(Original )) && "Address must be a Phi or Select node") ? static_cast <void> (0) : __assert_fail ("(isa<PHINode>(Original) || isa<SelectInst>(Original)) && \"Address must be a Phi or Select node\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 3436, __PRETTY_FUNCTION__)); | ||||
3437 | auto *Dummy = UndefValue::get(CommonType); | ||||
3438 | Worklist.push_back(Original); | ||||
3439 | while (!Worklist.empty()) { | ||||
3440 | Value *Current = Worklist.pop_back_val(); | ||||
3441 | // if it is already visited or it is an ending value then skip it. | ||||
3442 | if (Map.find(Current) != Map.end()) | ||||
3443 | continue; | ||||
3444 | TraverseOrder.push_back(Current); | ||||
3445 | |||||
3446 | // CurrentValue must be a Phi node or select. All others must be covered | ||||
3447 | // by anchors. | ||||
3448 | if (SelectInst *CurrentSelect = dyn_cast<SelectInst>(Current)) { | ||||
3449 | // Is it OK to get metadata from OrigSelect?! | ||||
3450 | // Create a Select placeholder with dummy value. | ||||
3451 | SelectInst *Select = SelectInst::Create( | ||||
3452 | CurrentSelect->getCondition(), Dummy, Dummy, | ||||
3453 | CurrentSelect->getName(), CurrentSelect, CurrentSelect); | ||||
3454 | Map[Current] = Select; | ||||
3455 | ST.insertNewSelect(Select); | ||||
3456 | // We are interested in True and False values. | ||||
3457 | Worklist.push_back(CurrentSelect->getTrueValue()); | ||||
3458 | Worklist.push_back(CurrentSelect->getFalseValue()); | ||||
3459 | } else { | ||||
3460 | // It must be a Phi node then. | ||||
3461 | PHINode *CurrentPhi = cast<PHINode>(Current); | ||||
3462 | unsigned PredCount = CurrentPhi->getNumIncomingValues(); | ||||
3463 | PHINode *PHI = | ||||
3464 | PHINode::Create(CommonType, PredCount, "sunk_phi", CurrentPhi); | ||||
3465 | Map[Current] = PHI; | ||||
3466 | ST.insertNewPhi(PHI); | ||||
3467 | for (Value *P : CurrentPhi->incoming_values()) | ||||
3468 | Worklist.push_back(P); | ||||
3469 | } | ||||
3470 | } | ||||
3471 | } | ||||
3472 | |||||
3473 | bool addrModeCombiningAllowed() { | ||||
3474 | if (DisableComplexAddrModes) | ||||
3475 | return false; | ||||
3476 | switch (DifferentField) { | ||||
3477 | default: | ||||
3478 | return false; | ||||
3479 | case ExtAddrMode::BaseRegField: | ||||
3480 | return AddrSinkCombineBaseReg; | ||||
3481 | case ExtAddrMode::BaseGVField: | ||||
3482 | return AddrSinkCombineBaseGV; | ||||
3483 | case ExtAddrMode::BaseOffsField: | ||||
3484 | return AddrSinkCombineBaseOffs; | ||||
3485 | case ExtAddrMode::ScaledRegField: | ||||
3486 | return AddrSinkCombineScaledReg; | ||||
3487 | } | ||||
3488 | } | ||||
3489 | }; | ||||
3490 | } // end anonymous namespace | ||||
3491 | |||||
3492 | /// Try adding ScaleReg*Scale to the current addressing mode. | ||||
3493 | /// Return true and update AddrMode if this addr mode is legal for the target, | ||||
3494 | /// false if not. | ||||
3495 | bool AddressingModeMatcher::matchScaledValue(Value *ScaleReg, int64_t Scale, | ||||
3496 | unsigned Depth) { | ||||
3497 | // If Scale is 1, then this is the same as adding ScaleReg to the addressing | ||||
3498 | // mode. Just process that directly. | ||||
3499 | if (Scale == 1) | ||||
3500 | return matchAddr(ScaleReg, Depth); | ||||
3501 | |||||
3502 | // If the scale is 0, it takes nothing to add this. | ||||
3503 | if (Scale == 0) | ||||
3504 | return true; | ||||
3505 | |||||
3506 | // If we already have a scale of this value, we can add to it, otherwise, we | ||||
3507 | // need an available scale field. | ||||
3508 | if (AddrMode.Scale != 0 && AddrMode.ScaledReg != ScaleReg) | ||||
3509 | return false; | ||||
3510 | |||||
3511 | ExtAddrMode TestAddrMode = AddrMode; | ||||
3512 | |||||
3513 | // Add scale to turn X*4+X*3 -> X*7. This could also do things like | ||||
3514 | // [A+B + A*7] -> [B+A*8]. | ||||
3515 | TestAddrMode.Scale += Scale; | ||||
3516 | TestAddrMode.ScaledReg = ScaleReg; | ||||
3517 | |||||
3518 | // If the new address isn't legal, bail out. | ||||
3519 | if (!TLI.isLegalAddressingMode(DL, TestAddrMode, AccessTy, AddrSpace)) | ||||
3520 | return false; | ||||
3521 | |||||
3522 | // It was legal, so commit it. | ||||
3523 | AddrMode = TestAddrMode; | ||||
3524 | |||||
3525 | // Okay, we decided that we can add ScaleReg+Scale to AddrMode. Check now | ||||
3526 | // to see if ScaleReg is actually X+C. If so, we can turn this into adding | ||||
3527 | // X*Scale + C*Scale to addr mode. | ||||
3528 | ConstantInt *CI = nullptr; Value *AddLHS = nullptr; | ||||
3529 | if (isa<Instruction>(ScaleReg) && // not a constant expr. | ||||
3530 | match(ScaleReg, m_Add(m_Value(AddLHS), m_ConstantInt(CI)))) { | ||||
3531 | TestAddrMode.InBounds = false; | ||||
3532 | TestAddrMode.ScaledReg = AddLHS; | ||||
3533 | TestAddrMode.BaseOffs += CI->getSExtValue()*TestAddrMode.Scale; | ||||
3534 | |||||
3535 | // If this addressing mode is legal, commit it and remember that we folded | ||||
3536 | // this instruction. | ||||
3537 | if (TLI.isLegalAddressingMode(DL, TestAddrMode, AccessTy, AddrSpace)) { | ||||
3538 | AddrModeInsts.push_back(cast<Instruction>(ScaleReg)); | ||||
3539 | AddrMode = TestAddrMode; | ||||
3540 | return true; | ||||
3541 | } | ||||
3542 | } | ||||
3543 | |||||
3544 | // Otherwise, not (x+c)*scale, just return what we have. | ||||
3545 | return true; | ||||
3546 | } | ||||
3547 | |||||
3548 | /// This is a little filter, which returns true if an addressing computation | ||||
3549 | /// involving I might be folded into a load/store accessing it. | ||||
3550 | /// This doesn't need to be perfect, but needs to accept at least | ||||
3551 | /// the set of instructions that MatchOperationAddr can. | ||||
3552 | static bool MightBeFoldableInst(Instruction *I) { | ||||
3553 | switch (I->getOpcode()) { | ||||
3554 | case Instruction::BitCast: | ||||
3555 | case Instruction::AddrSpaceCast: | ||||
3556 | // Don't touch identity bitcasts. | ||||
3557 | if (I->getType() == I->getOperand(0)->getType()) | ||||
3558 | return false; | ||||
3559 | return I->getType()->isIntOrPtrTy(); | ||||
3560 | case Instruction::PtrToInt: | ||||
3561 | // PtrToInt is always a noop, as we know that the int type is pointer sized. | ||||
3562 | return true; | ||||
3563 | case Instruction::IntToPtr: | ||||
3564 | // We know the input is intptr_t, so this is foldable. | ||||
3565 | return true; | ||||
3566 | case Instruction::Add: | ||||
3567 | return true; | ||||
3568 | case Instruction::Mul: | ||||
3569 | case Instruction::Shl: | ||||
3570 | // Can only handle X*C and X << C. | ||||
3571 | return isa<ConstantInt>(I->getOperand(1)); | ||||
3572 | case Instruction::GetElementPtr: | ||||
3573 | return true; | ||||
3574 | default: | ||||
3575 | return false; | ||||
3576 | } | ||||
3577 | } | ||||
3578 | |||||
3579 | /// Check whether or not \p Val is a legal instruction for \p TLI. | ||||
3580 | /// \note \p Val is assumed to be the product of some type promotion. | ||||
3581 | /// Therefore if \p Val has an undefined state in \p TLI, this is assumed | ||||
3582 | /// to be legal, as the non-promoted value would have had the same state. | ||||
3583 | static bool isPromotedInstructionLegal(const TargetLowering &TLI, | ||||
3584 | const DataLayout &DL, Value *Val) { | ||||
3585 | Instruction *PromotedInst = dyn_cast<Instruction>(Val); | ||||
3586 | if (!PromotedInst) | ||||
3587 | return false; | ||||
3588 | int ISDOpcode = TLI.InstructionOpcodeToISD(PromotedInst->getOpcode()); | ||||
3589 | // If the ISDOpcode is undefined, it was undefined before the promotion. | ||||
3590 | if (!ISDOpcode) | ||||
3591 | return true; | ||||
3592 | // Otherwise, check if the promoted instruction is legal or not. | ||||
3593 | return TLI.isOperationLegalOrCustom( | ||||
3594 | ISDOpcode, TLI.getValueType(DL, PromotedInst->getType())); | ||||
3595 | } | ||||
3596 | |||||
3597 | namespace { | ||||
3598 | |||||
3599 | /// Hepler class to perform type promotion. | ||||
3600 | class TypePromotionHelper { | ||||
3601 | /// Utility function to add a promoted instruction \p ExtOpnd to | ||||
3602 | /// \p PromotedInsts and record the type of extension we have seen. | ||||
3603 | static void addPromotedInst(InstrToOrigTy &PromotedInsts, | ||||
3604 | Instruction *ExtOpnd, | ||||
3605 | bool IsSExt) { | ||||
3606 | ExtType ExtTy = IsSExt ? SignExtension : ZeroExtension; | ||||
3607 | InstrToOrigTy::iterator It = PromotedInsts.find(ExtOpnd); | ||||
3608 | if (It != PromotedInsts.end()) { | ||||
3609 | // If the new extension is same as original, the information in | ||||
3610 | // PromotedInsts[ExtOpnd] is still correct. | ||||
3611 | if (It->second.getInt() == ExtTy) | ||||
3612 | return; | ||||
3613 | |||||
3614 | // Now the new extension is different from old extension, we make | ||||
3615 | // the type information invalid by setting extension type to | ||||
3616 | // BothExtension. | ||||
3617 | ExtTy = BothExtension; | ||||
3618 | } | ||||
3619 | PromotedInsts[ExtOpnd] = TypeIsSExt(ExtOpnd->getType(), ExtTy); | ||||
3620 | } | ||||
3621 | |||||
3622 | /// Utility function to query the original type of instruction \p Opnd | ||||
3623 | /// with a matched extension type. If the extension doesn't match, we | ||||
3624 | /// cannot use the information we had on the original type. | ||||
3625 | /// BothExtension doesn't match any extension type. | ||||
3626 | static const Type *getOrigType(const InstrToOrigTy &PromotedInsts, | ||||
3627 | Instruction *Opnd, | ||||
3628 | bool IsSExt) { | ||||
3629 | ExtType ExtTy = IsSExt ? SignExtension : ZeroExtension; | ||||
3630 | InstrToOrigTy::const_iterator It = PromotedInsts.find(Opnd); | ||||
3631 | if (It != PromotedInsts.end() && It->second.getInt() == ExtTy) | ||||
3632 | return It->second.getPointer(); | ||||
3633 | return nullptr; | ||||
3634 | } | ||||
3635 | |||||
3636 | /// Utility function to check whether or not a sign or zero extension | ||||
3637 | /// of \p Inst with \p ConsideredExtType can be moved through \p Inst by | ||||
3638 | /// either using the operands of \p Inst or promoting \p Inst. | ||||
3639 | /// The type of the extension is defined by \p IsSExt. | ||||
3640 | /// In other words, check if: | ||||
3641 | /// ext (Ty Inst opnd1 opnd2 ... opndN) to ConsideredExtType. | ||||
3642 | /// #1 Promotion applies: | ||||
3643 | /// ConsideredExtType Inst (ext opnd1 to ConsideredExtType, ...). | ||||
3644 | /// #2 Operand reuses: | ||||
3645 | /// ext opnd1 to ConsideredExtType. | ||||
3646 | /// \p PromotedInsts maps the instructions to their type before promotion. | ||||
3647 | static bool canGetThrough(const Instruction *Inst, Type *ConsideredExtType, | ||||
3648 | const InstrToOrigTy &PromotedInsts, bool IsSExt); | ||||
3649 | |||||
3650 | /// Utility function to determine if \p OpIdx should be promoted when | ||||
3651 | /// promoting \p Inst. | ||||
3652 | static bool shouldExtOperand(const Instruction *Inst, int OpIdx) { | ||||
3653 | return !(isa<SelectInst>(Inst) && OpIdx == 0); | ||||
3654 | } | ||||
3655 | |||||
3656 | /// Utility function to promote the operand of \p Ext when this | ||||
3657 | /// operand is a promotable trunc or sext or zext. | ||||
3658 | /// \p PromotedInsts maps the instructions to their type before promotion. | ||||
3659 | /// \p CreatedInstsCost[out] contains the cost of all instructions | ||||
3660 | /// created to promote the operand of Ext. | ||||
3661 | /// Newly added extensions are inserted in \p Exts. | ||||
3662 | /// Newly added truncates are inserted in \p Truncs. | ||||
3663 | /// Should never be called directly. | ||||
3664 | /// \return The promoted value which is used instead of Ext. | ||||
3665 | static Value *promoteOperandForTruncAndAnyExt( | ||||
3666 | Instruction *Ext, TypePromotionTransaction &TPT, | ||||
3667 | InstrToOrigTy &PromotedInsts, unsigned &CreatedInstsCost, | ||||
3668 | SmallVectorImpl<Instruction *> *Exts, | ||||
3669 | SmallVectorImpl<Instruction *> *Truncs, const TargetLowering &TLI); | ||||
3670 | |||||
3671 | /// Utility function to promote the operand of \p Ext when this | ||||
3672 | /// operand is promotable and is not a supported trunc or sext. | ||||
3673 | /// \p PromotedInsts maps the instructions to their type before promotion. | ||||
3674 | /// \p CreatedInstsCost[out] contains the cost of all the instructions | ||||
3675 | /// created to promote the operand of Ext. | ||||
3676 | /// Newly added extensions are inserted in \p Exts. | ||||
3677 | /// Newly added truncates are inserted in \p Truncs. | ||||
3678 | /// Should never be called directly. | ||||
3679 | /// \return The promoted value which is used instead of Ext. | ||||
3680 | static Value *promoteOperandForOther(Instruction *Ext, | ||||
3681 | TypePromotionTransaction &TPT, | ||||
3682 | InstrToOrigTy &PromotedInsts, | ||||
3683 | unsigned &CreatedInstsCost, | ||||
3684 | SmallVectorImpl<Instruction *> *Exts, | ||||
3685 | SmallVectorImpl<Instruction *> *Truncs, | ||||
3686 | const TargetLowering &TLI, bool IsSExt); | ||||
3687 | |||||
3688 | /// \see promoteOperandForOther. | ||||
3689 | static Value *signExtendOperandForOther( | ||||
3690 | Instruction *Ext, TypePromotionTransaction &TPT, | ||||
3691 | InstrToOrigTy &PromotedInsts, unsigned &CreatedInstsCost, | ||||
3692 | SmallVectorImpl<Instruction *> *Exts, | ||||
3693 | SmallVectorImpl<Instruction *> *Truncs, const TargetLowering &TLI) { | ||||
3694 | return promoteOperandForOther(Ext, TPT, PromotedInsts, CreatedInstsCost, | ||||
3695 | Exts, Truncs, TLI, true); | ||||
3696 | } | ||||
3697 | |||||
3698 | /// \see promoteOperandForOther. | ||||
3699 | static Value *zeroExtendOperandForOther( | ||||
3700 | Instruction *Ext, TypePromotionTransaction &TPT, | ||||
3701 | InstrToOrigTy &PromotedInsts, unsigned &CreatedInstsCost, | ||||
3702 | SmallVectorImpl<Instruction *> *Exts, | ||||
3703 | SmallVectorImpl<Instruction *> *Truncs, const TargetLowering &TLI) { | ||||
3704 | return promoteOperandForOther(Ext, TPT, PromotedInsts, CreatedInstsCost, | ||||
3705 | Exts, Truncs, TLI, false); | ||||
3706 | } | ||||
3707 | |||||
3708 | public: | ||||
3709 | /// Type for the utility function that promotes the operand of Ext. | ||||
3710 | using Action = Value *(*)(Instruction *Ext, TypePromotionTransaction &TPT, | ||||
3711 | InstrToOrigTy &PromotedInsts, | ||||
3712 | unsigned &CreatedInstsCost, | ||||
3713 | SmallVectorImpl<Instruction *> *Exts, | ||||
3714 | SmallVectorImpl<Instruction *> *Truncs, | ||||
3715 | const TargetLowering &TLI); | ||||
3716 | |||||
3717 | /// Given a sign/zero extend instruction \p Ext, return the appropriate | ||||
3718 | /// action to promote the operand of \p Ext instead of using Ext. | ||||
3719 | /// \return NULL if no promotable action is possible with the current | ||||
3720 | /// sign extension. | ||||
3721 | /// \p InsertedInsts keeps track of all the instructions inserted by the | ||||
3722 | /// other CodeGenPrepare optimizations. This information is important | ||||
3723 | /// because we do not want to promote these instructions as CodeGenPrepare | ||||
3724 | /// will reinsert them later. Thus creating an infinite loop: create/remove. | ||||
3725 | /// \p PromotedInsts maps the instructions to their type before promotion. | ||||
3726 | static Action getAction(Instruction *Ext, const SetOfInstrs &InsertedInsts, | ||||
3727 | const TargetLowering &TLI, | ||||
3728 | const InstrToOrigTy &PromotedInsts); | ||||
3729 | }; | ||||
3730 | |||||
3731 | } // end anonymous namespace | ||||
3732 | |||||
3733 | bool TypePromotionHelper::canGetThrough(const Instruction *Inst, | ||||
3734 | Type *ConsideredExtType, | ||||
3735 | const InstrToOrigTy &PromotedInsts, | ||||
3736 | bool IsSExt) { | ||||
3737 | // The promotion helper does not know how to deal with vector types yet. | ||||
3738 | // To be able to fix that, we would need to fix the places where we | ||||
3739 | // statically extend, e.g., constants and such. | ||||
3740 | if (Inst->getType()->isVectorTy()) | ||||
3741 | return false; | ||||
3742 | |||||
3743 | // We can always get through zext. | ||||
3744 | if (isa<ZExtInst>(Inst)) | ||||
3745 | return true; | ||||
3746 | |||||
3747 | // sext(sext) is ok too. | ||||
3748 | if (IsSExt && isa<SExtInst>(Inst)) | ||||
3749 | return true; | ||||
3750 | |||||
3751 | // We can get through binary operator, if it is legal. In other words, the | ||||
3752 | // binary operator must have a nuw or nsw flag. | ||||
3753 | const BinaryOperator *BinOp = dyn_cast<BinaryOperator>(Inst); | ||||
3754 | if (BinOp && isa<OverflowingBinaryOperator>(BinOp) && | ||||
3755 | ((!IsSExt && BinOp->hasNoUnsignedWrap()) || | ||||
3756 | (IsSExt && BinOp->hasNoSignedWrap()))) | ||||
3757 | return true; | ||||
3758 | |||||
3759 | // ext(and(opnd, cst)) --> and(ext(opnd), ext(cst)) | ||||
3760 | if ((Inst->getOpcode() == Instruction::And || | ||||
3761 | Inst->getOpcode() == Instruction::Or)) | ||||
3762 | return true; | ||||
3763 | |||||
3764 | // ext(xor(opnd, cst)) --> xor(ext(opnd), ext(cst)) | ||||
3765 | if (Inst->getOpcode() == Instruction::Xor) { | ||||
3766 | const ConstantInt *Cst = dyn_cast<ConstantInt>(Inst->getOperand(1)); | ||||
3767 | // Make sure it is not a NOT. | ||||
3768 | if (Cst && !Cst->getValue().isAllOnesValue()) | ||||
3769 | return true; | ||||
3770 | } | ||||
3771 | |||||
3772 | // zext(shrl(opnd, cst)) --> shrl(zext(opnd), zext(cst)) | ||||
3773 | // It may change a poisoned value into a regular value, like | ||||
3774 | // zext i32 (shrl i8 %val, 12) --> shrl i32 (zext i8 %val), 12 | ||||
3775 | // poisoned value regular value | ||||
3776 | // It should be OK since undef covers valid value. | ||||
3777 | if (Inst->getOpcode() == Instruction::LShr && !IsSExt) | ||||
3778 | return true; | ||||
3779 | |||||
3780 | // and(ext(shl(opnd, cst)), cst) --> and(shl(ext(opnd), ext(cst)), cst) | ||||
3781 | // It may change a poisoned value into a regular value, like | ||||
3782 | // zext i32 (shl i8 %val, 12) --> shl i32 (zext i8 %val), 12 | ||||
3783 | // poisoned value regular value | ||||
3784 | // It should be OK since undef covers valid value. | ||||
3785 | if (Inst->getOpcode() == Instruction::Shl && Inst->hasOneUse()) { | ||||
3786 | const Instruction *ExtInst = | ||||
3787 | dyn_cast<const Instruction>(*Inst->user_begin()); | ||||
3788 | if (ExtInst->hasOneUse()) { | ||||
3789 | const Instruction *AndInst = | ||||
3790 | dyn_cast<const Instruction>(*ExtInst->user_begin()); | ||||
3791 | if (AndInst && AndInst->getOpcode() == Instruction::And) { | ||||
3792 | const ConstantInt *Cst = dyn_cast<ConstantInt>(AndInst->getOperand(1)); | ||||
3793 | if (Cst && | ||||
3794 | Cst->getValue().isIntN(Inst->getType()->getIntegerBitWidth())) | ||||
3795 | return true; | ||||
3796 | } | ||||
3797 | } | ||||
3798 | } | ||||
3799 | |||||
3800 | // Check if we can do the following simplification. | ||||
3801 | // ext(trunc(opnd)) --> ext(opnd) | ||||
3802 | if (!isa<TruncInst>(Inst)) | ||||
3803 | return false; | ||||
3804 | |||||
3805 | Value *OpndVal = Inst->getOperand(0); | ||||
3806 | // Check if we can use this operand in the extension. | ||||
3807 | // If the type is larger than the result type of the extension, we cannot. | ||||
3808 | if (!OpndVal->getType()->isIntegerTy() || | ||||
3809 | OpndVal->getType()->getIntegerBitWidth() > | ||||
3810 | ConsideredExtType->getIntegerBitWidth()) | ||||
3811 | return false; | ||||
3812 | |||||
3813 | // If the operand of the truncate is not an instruction, we will not have | ||||
3814 | // any information on the dropped bits. | ||||
3815 | // (Actually we could for constant but it is not worth the extra logic). | ||||
3816 | Instruction *Opnd = dyn_cast<Instruction>(OpndVal); | ||||
3817 | if (!Opnd) | ||||
3818 | return false; | ||||
3819 | |||||
3820 | // Check if the source of the type is narrow enough. | ||||
3821 | // I.e., check that trunc just drops extended bits of the same kind of | ||||
3822 | // the extension. | ||||
3823 | // #1 get the type of the operand and check the kind of the extended bits. | ||||
3824 | const Type *OpndType = getOrigType(PromotedInsts, Opnd, IsSExt); | ||||
3825 | if (OpndType) | ||||
3826 | ; | ||||
3827 | else if ((IsSExt && isa<SExtInst>(Opnd)) || (!IsSExt && isa<ZExtInst>(Opnd))) | ||||
3828 | OpndType = Opnd->getOperand(0)->getType(); | ||||
3829 | else | ||||
3830 | return false; | ||||
3831 | |||||
3832 | // #2 check that the truncate just drops extended bits. | ||||
3833 | return Inst->getType()->getIntegerBitWidth() >= | ||||
3834 | OpndType->getIntegerBitWidth(); | ||||
3835 | } | ||||
3836 | |||||
3837 | TypePromotionHelper::Action TypePromotionHelper::getAction( | ||||
3838 | Instruction *Ext, const SetOfInstrs &InsertedInsts, | ||||
3839 | const TargetLowering &TLI, const InstrToOrigTy &PromotedInsts) { | ||||
3840 | assert((isa<SExtInst>(Ext) || isa<ZExtInst>(Ext)) &&(((isa<SExtInst>(Ext) || isa<ZExtInst>(Ext)) && "Unexpected instruction type") ? static_cast<void> (0) : __assert_fail ("(isa<SExtInst>(Ext) || isa<ZExtInst>(Ext)) && \"Unexpected instruction type\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 3841, __PRETTY_FUNCTION__)) | ||||
3841 | "Unexpected instruction type")(((isa<SExtInst>(Ext) || isa<ZExtInst>(Ext)) && "Unexpected instruction type") ? static_cast<void> (0) : __assert_fail ("(isa<SExtInst>(Ext) || isa<ZExtInst>(Ext)) && \"Unexpected instruction type\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 3841, __PRETTY_FUNCTION__)); | ||||
3842 | Instruction *ExtOpnd = dyn_cast<Instruction>(Ext->getOperand(0)); | ||||
3843 | Type *ExtTy = Ext->getType(); | ||||
3844 | bool IsSExt = isa<SExtInst>(Ext); | ||||
3845 | // If the operand of the extension is not an instruction, we cannot | ||||
3846 | // get through. | ||||
3847 | // If it, check we can get through. | ||||
3848 | if (!ExtOpnd || !canGetThrough(ExtOpnd, ExtTy, PromotedInsts, IsSExt)) | ||||
3849 | return nullptr; | ||||
3850 | |||||
3851 | // Do not promote if the operand has been added by codegenprepare. | ||||
3852 | // Otherwise, it means we are undoing an optimization that is likely to be | ||||
3853 | // redone, thus causing potential infinite loop. | ||||
3854 | if (isa<TruncInst>(ExtOpnd) && InsertedInsts.count(ExtOpnd)) | ||||
3855 | return nullptr; | ||||
3856 | |||||
3857 | // SExt or Trunc instructions. | ||||
3858 | // Return the related handler. | ||||
3859 | if (isa<SExtInst>(ExtOpnd) || isa<TruncInst>(ExtOpnd) || | ||||
3860 | isa<ZExtInst>(ExtOpnd)) | ||||
3861 | return promoteOperandForTruncAndAnyExt; | ||||
3862 | |||||
3863 | // Regular instruction. | ||||
3864 | // Abort early if we will have to insert non-free instructions. | ||||
3865 | if (!ExtOpnd->hasOneUse() && !TLI.isTruncateFree(ExtTy, ExtOpnd->getType())) | ||||
3866 | return nullptr; | ||||
3867 | return IsSExt ? signExtendOperandForOther : zeroExtendOperandForOther; | ||||
3868 | } | ||||
3869 | |||||
3870 | Value *TypePromotionHelper::promoteOperandForTruncAndAnyExt( | ||||
3871 | Instruction *SExt, TypePromotionTransaction &TPT, | ||||
3872 | InstrToOrigTy &PromotedInsts, unsigned &CreatedInstsCost, | ||||
3873 | SmallVectorImpl<Instruction *> *Exts, | ||||
3874 | SmallVectorImpl<Instruction *> *Truncs, const TargetLowering &TLI) { | ||||
3875 | // By construction, the operand of SExt is an instruction. Otherwise we cannot | ||||
3876 | // get through it and this method should not be called. | ||||
3877 | Instruction *SExtOpnd = cast<Instruction>(SExt->getOperand(0)); | ||||
3878 | Value *ExtVal = SExt; | ||||
3879 | bool HasMergedNonFreeExt = false; | ||||
3880 | if (isa<ZExtInst>(SExtOpnd)) { | ||||
3881 | // Replace s|zext(zext(opnd)) | ||||
3882 | // => zext(opnd). | ||||
3883 | HasMergedNonFreeExt = !TLI.isExtFree(SExtOpnd); | ||||
3884 | Value *ZExt = | ||||
3885 | TPT.createZExt(SExt, SExtOpnd->getOperand(0), SExt->getType()); | ||||
3886 | TPT.replaceAllUsesWith(SExt, ZExt); | ||||
3887 | TPT.eraseInstruction(SExt); | ||||
3888 | ExtVal = ZExt; | ||||
3889 | } else { | ||||
3890 | // Replace z|sext(trunc(opnd)) or sext(sext(opnd)) | ||||
3891 | // => z|sext(opnd). | ||||
3892 | TPT.setOperand(SExt, 0, SExtOpnd->getOperand(0)); | ||||
3893 | } | ||||
3894 | CreatedInstsCost = 0; | ||||
3895 | |||||
3896 | // Remove dead code. | ||||
3897 | if (SExtOpnd->use_empty()) | ||||
3898 | TPT.eraseInstruction(SExtOpnd); | ||||
3899 | |||||
3900 | // Check if the extension is still needed. | ||||
3901 | Instruction *ExtInst = dyn_cast<Instruction>(ExtVal); | ||||
3902 | if (!ExtInst || ExtInst->getType() != ExtInst->getOperand(0)->getType()) { | ||||
3903 | if (ExtInst) { | ||||
3904 | if (Exts) | ||||
3905 | Exts->push_back(ExtInst); | ||||
3906 | CreatedInstsCost = !TLI.isExtFree(ExtInst) && !HasMergedNonFreeExt; | ||||
3907 | } | ||||
3908 | return ExtVal; | ||||
3909 | } | ||||
3910 | |||||
3911 | // At this point we have: ext ty opnd to ty. | ||||
3912 | // Reassign the uses of ExtInst to the opnd and remove ExtInst. | ||||
3913 | Value *NextVal = ExtInst->getOperand(0); | ||||
3914 | TPT.eraseInstruction(ExtInst, NextVal); | ||||
3915 | return NextVal; | ||||
3916 | } | ||||
3917 | |||||
3918 | Value *TypePromotionHelper::promoteOperandForOther( | ||||
3919 | Instruction *Ext, TypePromotionTransaction &TPT, | ||||
3920 | InstrToOrigTy &PromotedInsts, unsigned &CreatedInstsCost, | ||||
3921 | SmallVectorImpl<Instruction *> *Exts, | ||||
3922 | SmallVectorImpl<Instruction *> *Truncs, const TargetLowering &TLI, | ||||
3923 | bool IsSExt) { | ||||
3924 | // By construction, the operand of Ext is an instruction. Otherwise we cannot | ||||
3925 | // get through it and this method should not be called. | ||||
3926 | Instruction *ExtOpnd = cast<Instruction>(Ext->getOperand(0)); | ||||
3927 | CreatedInstsCost = 0; | ||||
3928 | if (!ExtOpnd->hasOneUse()) { | ||||
3929 | // ExtOpnd will be promoted. | ||||
3930 | // All its uses, but Ext, will need to use a truncated value of the | ||||
3931 | // promoted version. | ||||
3932 | // Create the truncate now. | ||||
3933 | Value *Trunc = TPT.createTrunc(Ext, ExtOpnd->getType()); | ||||
3934 | if (Instruction *ITrunc = dyn_cast<Instruction>(Trunc)) { | ||||
3935 | // Insert it just after the definition. | ||||
3936 | ITrunc->moveAfter(ExtOpnd); | ||||
3937 | if (Truncs) | ||||
3938 | Truncs->push_back(ITrunc); | ||||
3939 | } | ||||
3940 | |||||
3941 | TPT.replaceAllUsesWith(ExtOpnd, Trunc); | ||||
3942 | // Restore the operand of Ext (which has been replaced by the previous call | ||||
3943 | // to replaceAllUsesWith) to avoid creating a cycle trunc <-> sext. | ||||
3944 | TPT.setOperand(Ext, 0, ExtOpnd); | ||||
3945 | } | ||||
3946 | |||||
3947 | // Get through the Instruction: | ||||
3948 | // 1. Update its type. | ||||
3949 | // 2. Replace the uses of Ext by Inst. | ||||
3950 | // 3. Extend each operand that needs to be extended. | ||||
3951 | |||||
3952 | // Remember the original type of the instruction before promotion. | ||||
3953 | // This is useful to know that the high bits are sign extended bits. | ||||
3954 | addPromotedInst(PromotedInsts, ExtOpnd, IsSExt); | ||||
3955 | // Step #1. | ||||
3956 | TPT.mutateType(ExtOpnd, Ext->getType()); | ||||
3957 | // Step #2. | ||||
3958 | TPT.replaceAllUsesWith(Ext, ExtOpnd); | ||||
3959 | // Step #3. | ||||
3960 | Instruction *ExtForOpnd = Ext; | ||||
3961 | |||||
3962 | LLVM_DEBUG(dbgs() << "Propagate Ext to operands\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Propagate Ext to operands\n" ; } } while (false); | ||||
3963 | for (int OpIdx = 0, EndOpIdx = ExtOpnd->getNumOperands(); OpIdx != EndOpIdx; | ||||
3964 | ++OpIdx) { | ||||
3965 | LLVM_DEBUG(dbgs() << "Operand:\n" << *(ExtOpnd->getOperand(OpIdx)) << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Operand:\n" << * (ExtOpnd->getOperand(OpIdx)) << '\n'; } } while (false ); | ||||
3966 | if (ExtOpnd->getOperand(OpIdx)->getType() == Ext->getType() || | ||||
3967 | !shouldExtOperand(ExtOpnd, OpIdx)) { | ||||
3968 | LLVM_DEBUG(dbgs() << "No need to propagate\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "No need to propagate\n" ; } } while (false); | ||||
3969 | continue; | ||||
3970 | } | ||||
3971 | // Check if we can statically extend the operand. | ||||
3972 | Value *Opnd = ExtOpnd->getOperand(OpIdx); | ||||
3973 | if (const ConstantInt *Cst = dyn_cast<ConstantInt>(Opnd)) { | ||||
3974 | LLVM_DEBUG(dbgs() << "Statically extend\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Statically extend\n"; } } while (false); | ||||
3975 | unsigned BitWidth = Ext->getType()->getIntegerBitWidth(); | ||||
3976 | APInt CstVal = IsSExt ? Cst->getValue().sext(BitWidth) | ||||
3977 | : Cst->getValue().zext(BitWidth); | ||||
3978 | TPT.setOperand(ExtOpnd, OpIdx, ConstantInt::get(Ext->getType(), CstVal)); | ||||
3979 | continue; | ||||
3980 | } | ||||
3981 | // UndefValue are typed, so we have to statically sign extend them. | ||||
3982 | if (isa<UndefValue>(Opnd)) { | ||||
3983 | LLVM_DEBUG(dbgs() << "Statically extend\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Statically extend\n"; } } while (false); | ||||
3984 | TPT.setOperand(ExtOpnd, OpIdx, UndefValue::get(Ext->getType())); | ||||
3985 | continue; | ||||
3986 | } | ||||
3987 | |||||
3988 | // Otherwise we have to explicitly sign extend the operand. | ||||
3989 | // Check if Ext was reused to extend an operand. | ||||
3990 | if (!ExtForOpnd) { | ||||
3991 | // If yes, create a new one. | ||||
3992 | LLVM_DEBUG(dbgs() << "More operands to ext\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "More operands to ext\n" ; } } while (false); | ||||
3993 | Value *ValForExtOpnd = IsSExt ? TPT.createSExt(Ext, Opnd, Ext->getType()) | ||||
3994 | : TPT.createZExt(Ext, Opnd, Ext->getType()); | ||||
3995 | if (!isa<Instruction>(ValForExtOpnd)) { | ||||
3996 | TPT.setOperand(ExtOpnd, OpIdx, ValForExtOpnd); | ||||
3997 | continue; | ||||
3998 | } | ||||
3999 | ExtForOpnd = cast<Instruction>(ValForExtOpnd); | ||||
4000 | } | ||||
4001 | if (Exts) | ||||
4002 | Exts->push_back(ExtForOpnd); | ||||
4003 | TPT.setOperand(ExtForOpnd, 0, Opnd); | ||||
4004 | |||||
4005 | // Move the sign extension before the insertion point. | ||||
4006 | TPT.moveBefore(ExtForOpnd, ExtOpnd); | ||||
4007 | TPT.setOperand(ExtOpnd, OpIdx, ExtForOpnd); | ||||
4008 | CreatedInstsCost += !TLI.isExtFree(ExtForOpnd); | ||||
4009 | // If more sext are required, new instructions will have to be created. | ||||
4010 | ExtForOpnd = nullptr; | ||||
4011 | } | ||||
4012 | if (ExtForOpnd == Ext) { | ||||
4013 | LLVM_DEBUG(dbgs() << "Extension is useless now\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Extension is useless now\n" ; } } while (false); | ||||
4014 | TPT.eraseInstruction(Ext); | ||||
4015 | } | ||||
4016 | return ExtOpnd; | ||||
4017 | } | ||||
4018 | |||||
4019 | /// Check whether or not promoting an instruction to a wider type is profitable. | ||||
4020 | /// \p NewCost gives the cost of extension instructions created by the | ||||
4021 | /// promotion. | ||||
4022 | /// \p OldCost gives the cost of extension instructions before the promotion | ||||
4023 | /// plus the number of instructions that have been | ||||
4024 | /// matched in the addressing mode the promotion. | ||||
4025 | /// \p PromotedOperand is the value that has been promoted. | ||||
4026 | /// \return True if the promotion is profitable, false otherwise. | ||||
4027 | bool AddressingModeMatcher::isPromotionProfitable( | ||||
4028 | unsigned NewCost, unsigned OldCost, Value *PromotedOperand) const { | ||||
4029 | LLVM_DEBUG(dbgs() << "OldCost: " << OldCost << "\tNewCost: " << NewCostdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "OldCost: " << OldCost << "\tNewCost: " << NewCost << '\n'; } } while (false) | ||||
4030 | << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "OldCost: " << OldCost << "\tNewCost: " << NewCost << '\n'; } } while (false); | ||||
4031 | // The cost of the new extensions is greater than the cost of the | ||||
4032 | // old extension plus what we folded. | ||||
4033 | // This is not profitable. | ||||
4034 | if (NewCost > OldCost) | ||||
4035 | return false; | ||||
4036 | if (NewCost < OldCost) | ||||
4037 | return true; | ||||
4038 | // The promotion is neutral but it may help folding the sign extension in | ||||
4039 | // loads for instance. | ||||
4040 | // Check that we did not create an illegal instruction. | ||||
4041 | return isPromotedInstructionLegal(TLI, DL, PromotedOperand); | ||||
4042 | } | ||||
4043 | |||||
4044 | /// Given an instruction or constant expr, see if we can fold the operation | ||||
4045 | /// into the addressing mode. If so, update the addressing mode and return | ||||
4046 | /// true, otherwise return false without modifying AddrMode. | ||||
4047 | /// If \p MovedAway is not NULL, it contains the information of whether or | ||||
4048 | /// not AddrInst has to be folded into the addressing mode on success. | ||||
4049 | /// If \p MovedAway == true, \p AddrInst will not be part of the addressing | ||||
4050 | /// because it has been moved away. | ||||
4051 | /// Thus AddrInst must not be added in the matched instructions. | ||||
4052 | /// This state can happen when AddrInst is a sext, since it may be moved away. | ||||
4053 | /// Therefore, AddrInst may not be valid when MovedAway is true and it must | ||||
4054 | /// not be referenced anymore. | ||||
4055 | bool AddressingModeMatcher::matchOperationAddr(User *AddrInst, unsigned Opcode, | ||||
4056 | unsigned Depth, | ||||
4057 | bool *MovedAway) { | ||||
4058 | // Avoid exponential behavior on extremely deep expression trees. | ||||
4059 | if (Depth >= 5) return false; | ||||
4060 | |||||
4061 | // By default, all matched instructions stay in place. | ||||
4062 | if (MovedAway) | ||||
4063 | *MovedAway = false; | ||||
4064 | |||||
4065 | switch (Opcode) { | ||||
4066 | case Instruction::PtrToInt: | ||||
4067 | // PtrToInt is always a noop, as we know that the int type is pointer sized. | ||||
4068 | return matchAddr(AddrInst->getOperand(0), Depth); | ||||
4069 | case Instruction::IntToPtr: { | ||||
4070 | auto AS = AddrInst->getType()->getPointerAddressSpace(); | ||||
4071 | auto PtrTy = MVT::getIntegerVT(DL.getPointerSizeInBits(AS)); | ||||
4072 | // This inttoptr is a no-op if the integer type is pointer sized. | ||||
4073 | if (TLI.getValueType(DL, AddrInst->getOperand(0)->getType()) == PtrTy) | ||||
4074 | return matchAddr(AddrInst->getOperand(0), Depth); | ||||
4075 | return false; | ||||
4076 | } | ||||
4077 | case Instruction::BitCast: | ||||
4078 | // BitCast is always a noop, and we can handle it as long as it is | ||||
4079 | // int->int or pointer->pointer (we don't want int<->fp or something). | ||||
4080 | if (AddrInst->getOperand(0)->getType()->isIntOrPtrTy() && | ||||
4081 | // Don't touch identity bitcasts. These were probably put here by LSR, | ||||
4082 | // and we don't want to mess around with them. Assume it knows what it | ||||
4083 | // is doing. | ||||
4084 | AddrInst->getOperand(0)->getType() != AddrInst->getType()) | ||||
4085 | return matchAddr(AddrInst->getOperand(0), Depth); | ||||
4086 | return false; | ||||
4087 | case Instruction::AddrSpaceCast: { | ||||
4088 | unsigned SrcAS | ||||
4089 | = AddrInst->getOperand(0)->getType()->getPointerAddressSpace(); | ||||
4090 | unsigned DestAS = AddrInst->getType()->getPointerAddressSpace(); | ||||
4091 | if (TLI.isNoopAddrSpaceCast(SrcAS, DestAS)) | ||||
4092 | return matchAddr(AddrInst->getOperand(0), Depth); | ||||
4093 | return false; | ||||
4094 | } | ||||
4095 | case Instruction::Add: { | ||||
4096 | // Check to see if we can merge in the RHS then the LHS. If so, we win. | ||||
4097 | ExtAddrMode BackupAddrMode = AddrMode; | ||||
4098 | unsigned OldSize = AddrModeInsts.size(); | ||||
4099 | // Start a transaction at this point. | ||||
4100 | // The LHS may match but not the RHS. | ||||
4101 | // Therefore, we need a higher level restoration point to undo partially | ||||
4102 | // matched operation. | ||||
4103 | TypePromotionTransaction::ConstRestorationPt LastKnownGood = | ||||
4104 | TPT.getRestorationPoint(); | ||||
4105 | |||||
4106 | AddrMode.InBounds = false; | ||||
4107 | if (matchAddr(AddrInst->getOperand(1), Depth+1) && | ||||
4108 | matchAddr(AddrInst->getOperand(0), Depth+1)) | ||||
4109 | return true; | ||||
4110 | |||||
4111 | // Restore the old addr mode info. | ||||
4112 | AddrMode = BackupAddrMode; | ||||
4113 | AddrModeInsts.resize(OldSize); | ||||
4114 | TPT.rollback(LastKnownGood); | ||||
4115 | |||||
4116 | // Otherwise this was over-aggressive. Try merging in the LHS then the RHS. | ||||
4117 | if (matchAddr(AddrInst->getOperand(0), Depth+1) && | ||||
4118 | matchAddr(AddrInst->getOperand(1), Depth+1)) | ||||
4119 | return true; | ||||
4120 | |||||
4121 | // Otherwise we definitely can't merge the ADD in. | ||||
4122 | AddrMode = BackupAddrMode; | ||||
4123 | AddrModeInsts.resize(OldSize); | ||||
4124 | TPT.rollback(LastKnownGood); | ||||
4125 | break; | ||||
4126 | } | ||||
4127 | //case Instruction::Or: | ||||
4128 | // TODO: We can handle "Or Val, Imm" iff this OR is equivalent to an ADD. | ||||
4129 | //break; | ||||
4130 | case Instruction::Mul: | ||||
4131 | case Instruction::Shl: { | ||||
4132 | // Can only handle X*C and X << C. | ||||
4133 | AddrMode.InBounds = false; | ||||
4134 | ConstantInt *RHS = dyn_cast<ConstantInt>(AddrInst->getOperand(1)); | ||||
4135 | if (!RHS || RHS->getBitWidth() > 64) | ||||
4136 | return false; | ||||
4137 | int64_t Scale = RHS->getSExtValue(); | ||||
4138 | if (Opcode == Instruction::Shl) | ||||
4139 | Scale = 1LL << Scale; | ||||
4140 | |||||
4141 | return matchScaledValue(AddrInst->getOperand(0), Scale, Depth); | ||||
4142 | } | ||||
4143 | case Instruction::GetElementPtr: { | ||||
4144 | // Scan the GEP. We check it if it contains constant offsets and at most | ||||
4145 | // one variable offset. | ||||
4146 | int VariableOperand = -1; | ||||
4147 | unsigned VariableScale = 0; | ||||
4148 | |||||
4149 | int64_t ConstantOffset = 0; | ||||
4150 | gep_type_iterator GTI = gep_type_begin(AddrInst); | ||||
4151 | for (unsigned i = 1, e = AddrInst->getNumOperands(); i != e; ++i, ++GTI) { | ||||
4152 | if (StructType *STy = GTI.getStructTypeOrNull()) { | ||||
4153 | const StructLayout *SL = DL.getStructLayout(STy); | ||||
4154 | unsigned Idx = | ||||
4155 | cast<ConstantInt>(AddrInst->getOperand(i))->getZExtValue(); | ||||
4156 | ConstantOffset += SL->getElementOffset(Idx); | ||||
4157 | } else { | ||||
4158 | uint64_t TypeSize = DL.getTypeAllocSize(GTI.getIndexedType()); | ||||
4159 | if (ConstantInt *CI = dyn_cast<ConstantInt>(AddrInst->getOperand(i))) { | ||||
4160 | const APInt &CVal = CI->getValue(); | ||||
4161 | if (CVal.getMinSignedBits() <= 64) { | ||||
4162 | ConstantOffset += CVal.getSExtValue() * TypeSize; | ||||
4163 | continue; | ||||
4164 | } | ||||
4165 | } | ||||
4166 | if (TypeSize) { // Scales of zero don't do anything. | ||||
4167 | // We only allow one variable index at the moment. | ||||
4168 | if (VariableOperand != -1) | ||||
4169 | return false; | ||||
4170 | |||||
4171 | // Remember the variable index. | ||||
4172 | VariableOperand = i; | ||||
4173 | VariableScale = TypeSize; | ||||
4174 | } | ||||
4175 | } | ||||
4176 | } | ||||
4177 | |||||
4178 | // A common case is for the GEP to only do a constant offset. In this case, | ||||
4179 | // just add it to the disp field and check validity. | ||||
4180 | if (VariableOperand == -1) { | ||||
4181 | AddrMode.BaseOffs += ConstantOffset; | ||||
4182 | if (ConstantOffset == 0 || | ||||
4183 | TLI.isLegalAddressingMode(DL, AddrMode, AccessTy, AddrSpace)) { | ||||
4184 | // Check to see if we can fold the base pointer in too. | ||||
4185 | if (matchAddr(AddrInst->getOperand(0), Depth+1)) { | ||||
4186 | if (!cast<GEPOperator>(AddrInst)->isInBounds()) | ||||
4187 | AddrMode.InBounds = false; | ||||
4188 | return true; | ||||
4189 | } | ||||
4190 | } else if (EnableGEPOffsetSplit && isa<GetElementPtrInst>(AddrInst) && | ||||
4191 | TLI.shouldConsiderGEPOffsetSplit() && Depth == 0 && | ||||
4192 | ConstantOffset > 0) { | ||||
4193 | // Record GEPs with non-zero offsets as candidates for splitting in the | ||||
4194 | // event that the offset cannot fit into the r+i addressing mode. | ||||
4195 | // Simple and common case that only one GEP is used in calculating the | ||||
4196 | // address for the memory access. | ||||
4197 | Value *Base = AddrInst->getOperand(0); | ||||
4198 | auto *BaseI = dyn_cast<Instruction>(Base); | ||||
4199 | auto *GEP = cast<GetElementPtrInst>(AddrInst); | ||||
4200 | if (isa<Argument>(Base) || isa<GlobalValue>(Base) || | ||||
4201 | (BaseI && !isa<CastInst>(BaseI) && | ||||
4202 | !isa<GetElementPtrInst>(BaseI))) { | ||||
4203 | // Make sure the parent block allows inserting non-PHI instructions | ||||
4204 | // before the terminator. | ||||
4205 | BasicBlock *Parent = | ||||
4206 | BaseI ? BaseI->getParent() : &GEP->getFunction()->getEntryBlock(); | ||||
4207 | if (!Parent->getTerminator()->isEHPad()) | ||||
4208 | LargeOffsetGEP = std::make_pair(GEP, ConstantOffset); | ||||
4209 | } | ||||
4210 | } | ||||
4211 | AddrMode.BaseOffs -= ConstantOffset; | ||||
4212 | return false; | ||||
4213 | } | ||||
4214 | |||||
4215 | // Save the valid addressing mode in case we can't match. | ||||
4216 | ExtAddrMode BackupAddrMode = AddrMode; | ||||
4217 | unsigned OldSize = AddrModeInsts.size(); | ||||
4218 | |||||
4219 | // See if the scale and offset amount is valid for this target. | ||||
4220 | AddrMode.BaseOffs += ConstantOffset; | ||||
4221 | if (!cast<GEPOperator>(AddrInst)->isInBounds()) | ||||
4222 | AddrMode.InBounds = false; | ||||
4223 | |||||
4224 | // Match the base operand of the GEP. | ||||
4225 | if (!matchAddr(AddrInst->getOperand(0), Depth+1)) { | ||||
4226 | // If it couldn't be matched, just stuff the value in a register. | ||||
4227 | if (AddrMode.HasBaseReg) { | ||||
4228 | AddrMode = BackupAddrMode; | ||||
4229 | AddrModeInsts.resize(OldSize); | ||||
4230 | return false; | ||||
4231 | } | ||||
4232 | AddrMode.HasBaseReg = true; | ||||
4233 | AddrMode.BaseReg = AddrInst->getOperand(0); | ||||
4234 | } | ||||
4235 | |||||
4236 | // Match the remaining variable portion of the GEP. | ||||
4237 | if (!matchScaledValue(AddrInst->getOperand(VariableOperand), VariableScale, | ||||
4238 | Depth)) { | ||||
4239 | // If it couldn't be matched, try stuffing the base into a register | ||||
4240 | // instead of matching it, and retrying the match of the scale. | ||||
4241 | AddrMode = BackupAddrMode; | ||||
4242 | AddrModeInsts.resize(OldSize); | ||||
4243 | if (AddrMode.HasBaseReg) | ||||
4244 | return false; | ||||
4245 | AddrMode.HasBaseReg = true; | ||||
4246 | AddrMode.BaseReg = AddrInst->getOperand(0); | ||||
4247 | AddrMode.BaseOffs += ConstantOffset; | ||||
4248 | if (!matchScaledValue(AddrInst->getOperand(VariableOperand), | ||||
4249 | VariableScale, Depth)) { | ||||
4250 | // If even that didn't work, bail. | ||||
4251 | AddrMode = BackupAddrMode; | ||||
4252 | AddrModeInsts.resize(OldSize); | ||||
4253 | return false; | ||||
4254 | } | ||||
4255 | } | ||||
4256 | |||||
4257 | return true; | ||||
4258 | } | ||||
4259 | case Instruction::SExt: | ||||
4260 | case Instruction::ZExt: { | ||||
4261 | Instruction *Ext = dyn_cast<Instruction>(AddrInst); | ||||
4262 | if (!Ext) | ||||
4263 | return false; | ||||
4264 | |||||
4265 | // Try to move this ext out of the way of the addressing mode. | ||||
4266 | // Ask for a method for doing so. | ||||
4267 | TypePromotionHelper::Action TPH = | ||||
4268 | TypePromotionHelper::getAction(Ext, InsertedInsts, TLI, PromotedInsts); | ||||
4269 | if (!TPH) | ||||
4270 | return false; | ||||
4271 | |||||
4272 | TypePromotionTransaction::ConstRestorationPt LastKnownGood = | ||||
4273 | TPT.getRestorationPoint(); | ||||
4274 | unsigned CreatedInstsCost = 0; | ||||
4275 | unsigned ExtCost = !TLI.isExtFree(Ext); | ||||
4276 | Value *PromotedOperand = | ||||
4277 | TPH(Ext, TPT, PromotedInsts, CreatedInstsCost, nullptr, nullptr, TLI); | ||||
4278 | // SExt has been moved away. | ||||
4279 | // Thus either it will be rematched later in the recursive calls or it is | ||||
4280 | // gone. Anyway, we must not fold it into the addressing mode at this point. | ||||
4281 | // E.g., | ||||
4282 | // op = add opnd, 1 | ||||
4283 | // idx = ext op | ||||
4284 | // addr = gep base, idx | ||||
4285 | // is now: | ||||
4286 | // promotedOpnd = ext opnd <- no match here | ||||
4287 | // op = promoted_add promotedOpnd, 1 <- match (later in recursive calls) | ||||
4288 | // addr = gep base, op <- match | ||||
4289 | if (MovedAway) | ||||
4290 | *MovedAway = true; | ||||
4291 | |||||
4292 | assert(PromotedOperand &&((PromotedOperand && "TypePromotionHelper should have filtered out those cases" ) ? static_cast<void> (0) : __assert_fail ("PromotedOperand && \"TypePromotionHelper should have filtered out those cases\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 4293, __PRETTY_FUNCTION__)) | ||||
4293 | "TypePromotionHelper should have filtered out those cases")((PromotedOperand && "TypePromotionHelper should have filtered out those cases" ) ? static_cast<void> (0) : __assert_fail ("PromotedOperand && \"TypePromotionHelper should have filtered out those cases\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 4293, __PRETTY_FUNCTION__)); | ||||
4294 | |||||
4295 | ExtAddrMode BackupAddrMode = AddrMode; | ||||
4296 | unsigned OldSize = AddrModeInsts.size(); | ||||
4297 | |||||
4298 | if (!matchAddr(PromotedOperand, Depth) || | ||||
4299 | // The total of the new cost is equal to the cost of the created | ||||
4300 | // instructions. | ||||
4301 | // The total of the old cost is equal to the cost of the extension plus | ||||
4302 | // what we have saved in the addressing mode. | ||||
4303 | !isPromotionProfitable(CreatedInstsCost, | ||||
4304 | ExtCost + (AddrModeInsts.size() - OldSize), | ||||
4305 | PromotedOperand)) { | ||||
4306 | AddrMode = BackupAddrMode; | ||||
4307 | AddrModeInsts.resize(OldSize); | ||||
4308 | LLVM_DEBUG(dbgs() << "Sign extension does not pay off: rollback\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Sign extension does not pay off: rollback\n" ; } } while (false); | ||||
4309 | TPT.rollback(LastKnownGood); | ||||
4310 | return false; | ||||
4311 | } | ||||
4312 | return true; | ||||
4313 | } | ||||
4314 | } | ||||
4315 | return false; | ||||
4316 | } | ||||
4317 | |||||
4318 | /// If we can, try to add the value of 'Addr' into the current addressing mode. | ||||
4319 | /// If Addr can't be added to AddrMode this returns false and leaves AddrMode | ||||
4320 | /// unmodified. This assumes that Addr is either a pointer type or intptr_t | ||||
4321 | /// for the target. | ||||
4322 | /// | ||||
4323 | bool AddressingModeMatcher::matchAddr(Value *Addr, unsigned Depth) { | ||||
4324 | // Start a transaction at this point that we will rollback if the matching | ||||
4325 | // fails. | ||||
4326 | TypePromotionTransaction::ConstRestorationPt LastKnownGood = | ||||
4327 | TPT.getRestorationPoint(); | ||||
4328 | if (ConstantInt *CI = dyn_cast<ConstantInt>(Addr)) { | ||||
4329 | // Fold in immediates if legal for the target. | ||||
4330 | AddrMode.BaseOffs += CI->getSExtValue(); | ||||
4331 | if (TLI.isLegalAddressingMode(DL, AddrMode, AccessTy, AddrSpace)) | ||||
4332 | return true; | ||||
4333 | AddrMode.BaseOffs -= CI->getSExtValue(); | ||||
4334 | } else if (GlobalValue *GV = dyn_cast<GlobalValue>(Addr)) { | ||||
4335 | // If this is a global variable, try to fold it into the addressing mode. | ||||
4336 | if (!AddrMode.BaseGV) { | ||||
4337 | AddrMode.BaseGV = GV; | ||||
4338 | if (TLI.isLegalAddressingMode(DL, AddrMode, AccessTy, AddrSpace)) | ||||
4339 | return true; | ||||
4340 | AddrMode.BaseGV = nullptr; | ||||
4341 | } | ||||
4342 | } else if (Instruction *I = dyn_cast<Instruction>(Addr)) { | ||||
4343 | ExtAddrMode BackupAddrMode = AddrMode; | ||||
4344 | unsigned OldSize = AddrModeInsts.size(); | ||||
4345 | |||||
4346 | // Check to see if it is possible to fold this operation. | ||||
4347 | bool MovedAway = false; | ||||
4348 | if (matchOperationAddr(I, I->getOpcode(), Depth, &MovedAway)) { | ||||
4349 | // This instruction may have been moved away. If so, there is nothing | ||||
4350 | // to check here. | ||||
4351 | if (MovedAway) | ||||
4352 | return true; | ||||
4353 | // Okay, it's possible to fold this. Check to see if it is actually | ||||
4354 | // *profitable* to do so. We use a simple cost model to avoid increasing | ||||
4355 | // register pressure too much. | ||||
4356 | if (I->hasOneUse() || | ||||
4357 | isProfitableToFoldIntoAddressingMode(I, BackupAddrMode, AddrMode)) { | ||||
4358 | AddrModeInsts.push_back(I); | ||||
4359 | return true; | ||||
4360 | } | ||||
4361 | |||||
4362 | // It isn't profitable to do this, roll back. | ||||
4363 | //cerr << "NOT FOLDING: " << *I; | ||||
4364 | AddrMode = BackupAddrMode; | ||||
4365 | AddrModeInsts.resize(OldSize); | ||||
4366 | TPT.rollback(LastKnownGood); | ||||
4367 | } | ||||
4368 | } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Addr)) { | ||||
4369 | if (matchOperationAddr(CE, CE->getOpcode(), Depth)) | ||||
4370 | return true; | ||||
4371 | TPT.rollback(LastKnownGood); | ||||
4372 | } else if (isa<ConstantPointerNull>(Addr)) { | ||||
4373 | // Null pointer gets folded without affecting the addressing mode. | ||||
4374 | return true; | ||||
4375 | } | ||||
4376 | |||||
4377 | // Worse case, the target should support [reg] addressing modes. :) | ||||
4378 | if (!AddrMode.HasBaseReg) { | ||||
4379 | AddrMode.HasBaseReg = true; | ||||
4380 | AddrMode.BaseReg = Addr; | ||||
4381 | // Still check for legality in case the target supports [imm] but not [i+r]. | ||||
4382 | if (TLI.isLegalAddressingMode(DL, AddrMode, AccessTy, AddrSpace)) | ||||
4383 | return true; | ||||
4384 | AddrMode.HasBaseReg = false; | ||||
4385 | AddrMode.BaseReg = nullptr; | ||||
4386 | } | ||||
4387 | |||||
4388 | // If the base register is already taken, see if we can do [r+r]. | ||||
4389 | if (AddrMode.Scale == 0) { | ||||
4390 | AddrMode.Scale = 1; | ||||
4391 | AddrMode.ScaledReg = Addr; | ||||
4392 | if (TLI.isLegalAddressingMode(DL, AddrMode, AccessTy, AddrSpace)) | ||||
4393 | return true; | ||||
4394 | AddrMode.Scale = 0; | ||||
4395 | AddrMode.ScaledReg = nullptr; | ||||
4396 | } | ||||
4397 | // Couldn't match. | ||||
4398 | TPT.rollback(LastKnownGood); | ||||
4399 | return false; | ||||
4400 | } | ||||
4401 | |||||
4402 | /// Check to see if all uses of OpVal by the specified inline asm call are due | ||||
4403 | /// to memory operands. If so, return true, otherwise return false. | ||||
4404 | static bool IsOperandAMemoryOperand(CallInst *CI, InlineAsm *IA, Value *OpVal, | ||||
4405 | const TargetLowering &TLI, | ||||
4406 | const TargetRegisterInfo &TRI) { | ||||
4407 | const Function *F = CI->getFunction(); | ||||
4408 | TargetLowering::AsmOperandInfoVector TargetConstraints = | ||||
4409 | TLI.ParseConstraints(F->getParent()->getDataLayout(), &TRI, | ||||
4410 | ImmutableCallSite(CI)); | ||||
4411 | |||||
4412 | for (unsigned i = 0, e = TargetConstraints.size(); i != e; ++i) { | ||||
4413 | TargetLowering::AsmOperandInfo &OpInfo = TargetConstraints[i]; | ||||
4414 | |||||
4415 | // Compute the constraint code and ConstraintType to use. | ||||
4416 | TLI.ComputeConstraintToUse(OpInfo, SDValue()); | ||||
4417 | |||||
4418 | // If this asm operand is our Value*, and if it isn't an indirect memory | ||||
4419 | // operand, we can't fold it! | ||||
4420 | if (OpInfo.CallOperandVal == OpVal && | ||||
4421 | (OpInfo.ConstraintType != TargetLowering::C_Memory || | ||||
4422 | !OpInfo.isIndirect)) | ||||
4423 | return false; | ||||
4424 | } | ||||
4425 | |||||
4426 | return true; | ||||
4427 | } | ||||
4428 | |||||
4429 | // Max number of memory uses to look at before aborting the search to conserve | ||||
4430 | // compile time. | ||||
4431 | static constexpr int MaxMemoryUsesToScan = 20; | ||||
4432 | |||||
4433 | /// Recursively walk all the uses of I until we find a memory use. | ||||
4434 | /// If we find an obviously non-foldable instruction, return true. | ||||
4435 | /// Add the ultimately found memory instructions to MemoryUses. | ||||
4436 | static bool FindAllMemoryUses( | ||||
4437 | Instruction *I, | ||||
4438 | SmallVectorImpl<std::pair<Instruction *, unsigned>> &MemoryUses, | ||||
4439 | SmallPtrSetImpl<Instruction *> &ConsideredInsts, const TargetLowering &TLI, | ||||
4440 | const TargetRegisterInfo &TRI, int SeenInsts = 0) { | ||||
4441 | // If we already considered this instruction, we're done. | ||||
4442 | if (!ConsideredInsts.insert(I).second) | ||||
4443 | return false; | ||||
4444 | |||||
4445 | // If this is an obviously unfoldable instruction, bail out. | ||||
4446 | if (!MightBeFoldableInst(I)) | ||||
4447 | return true; | ||||
4448 | |||||
4449 | const bool OptSize = I->getFunction()->hasOptSize(); | ||||
4450 | |||||
4451 | // Loop over all the uses, recursively processing them. | ||||
4452 | for (Use &U : I->uses()) { | ||||
4453 | // Conservatively return true if we're seeing a large number or a deep chain | ||||
4454 | // of users. This avoids excessive compilation times in pathological cases. | ||||
4455 | if (SeenInsts++ >= MaxMemoryUsesToScan) | ||||
4456 | return true; | ||||
4457 | |||||
4458 | Instruction *UserI = cast<Instruction>(U.getUser()); | ||||
4459 | if (LoadInst *LI = dyn_cast<LoadInst>(UserI)) { | ||||
4460 | MemoryUses.push_back(std::make_pair(LI, U.getOperandNo())); | ||||
4461 | continue; | ||||
4462 | } | ||||
4463 | |||||
4464 | if (StoreInst *SI = dyn_cast<StoreInst>(UserI)) { | ||||
4465 | unsigned opNo = U.getOperandNo(); | ||||
4466 | if (opNo != StoreInst::getPointerOperandIndex()) | ||||
4467 | return true; // Storing addr, not into addr. | ||||
4468 | MemoryUses.push_back(std::make_pair(SI, opNo)); | ||||
4469 | continue; | ||||
4470 | } | ||||
4471 | |||||
4472 | if (AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(UserI)) { | ||||
4473 | unsigned opNo = U.getOperandNo(); | ||||
4474 | if (opNo != AtomicRMWInst::getPointerOperandIndex()) | ||||
4475 | return true; // Storing addr, not into addr. | ||||
4476 | MemoryUses.push_back(std::make_pair(RMW, opNo)); | ||||
4477 | continue; | ||||
4478 | } | ||||
4479 | |||||
4480 | if (AtomicCmpXchgInst *CmpX = dyn_cast<AtomicCmpXchgInst>(UserI)) { | ||||
4481 | unsigned opNo = U.getOperandNo(); | ||||
4482 | if (opNo != AtomicCmpXchgInst::getPointerOperandIndex()) | ||||
4483 | return true; // Storing addr, not into addr. | ||||
4484 | MemoryUses.push_back(std::make_pair(CmpX, opNo)); | ||||
4485 | continue; | ||||
4486 | } | ||||
4487 | |||||
4488 | if (CallInst *CI = dyn_cast<CallInst>(UserI)) { | ||||
4489 | // If this is a cold call, we can sink the addressing calculation into | ||||
4490 | // the cold path. See optimizeCallInst | ||||
4491 | if (!OptSize && CI->hasFnAttr(Attribute::Cold)) | ||||
4492 | continue; | ||||
4493 | |||||
4494 | InlineAsm *IA = dyn_cast<InlineAsm>(CI->getCalledValue()); | ||||
4495 | if (!IA) return true; | ||||
4496 | |||||
4497 | // If this is a memory operand, we're cool, otherwise bail out. | ||||
4498 | if (!IsOperandAMemoryOperand(CI, IA, I, TLI, TRI)) | ||||
4499 | return true; | ||||
4500 | continue; | ||||
4501 | } | ||||
4502 | |||||
4503 | if (FindAllMemoryUses(UserI, MemoryUses, ConsideredInsts, TLI, TRI, | ||||
4504 | SeenInsts)) | ||||
4505 | return true; | ||||
4506 | } | ||||
4507 | |||||
4508 | return false; | ||||
4509 | } | ||||
4510 | |||||
4511 | /// Return true if Val is already known to be live at the use site that we're | ||||
4512 | /// folding it into. If so, there is no cost to include it in the addressing | ||||
4513 | /// mode. KnownLive1 and KnownLive2 are two values that we know are live at the | ||||
4514 | /// instruction already. | ||||
4515 | bool AddressingModeMatcher::valueAlreadyLiveAtInst(Value *Val,Value *KnownLive1, | ||||
4516 | Value *KnownLive2) { | ||||
4517 | // If Val is either of the known-live values, we know it is live! | ||||
4518 | if (Val == nullptr || Val == KnownLive1 || Val == KnownLive2) | ||||
4519 | return true; | ||||
4520 | |||||
4521 | // All values other than instructions and arguments (e.g. constants) are live. | ||||
4522 | if (!isa<Instruction>(Val) && !isa<Argument>(Val)) return true; | ||||
4523 | |||||
4524 | // If Val is a constant sized alloca in the entry block, it is live, this is | ||||
4525 | // true because it is just a reference to the stack/frame pointer, which is | ||||
4526 | // live for the whole function. | ||||
4527 | if (AllocaInst *AI = dyn_cast<AllocaInst>(Val)) | ||||
4528 | if (AI->isStaticAlloca()) | ||||
4529 | return true; | ||||
4530 | |||||
4531 | // Check to see if this value is already used in the memory instruction's | ||||
4532 | // block. If so, it's already live into the block at the very least, so we | ||||
4533 | // can reasonably fold it. | ||||
4534 | return Val->isUsedInBasicBlock(MemoryInst->getParent()); | ||||
4535 | } | ||||
4536 | |||||
4537 | /// It is possible for the addressing mode of the machine to fold the specified | ||||
4538 | /// instruction into a load or store that ultimately uses it. | ||||
4539 | /// However, the specified instruction has multiple uses. | ||||
4540 | /// Given this, it may actually increase register pressure to fold it | ||||
4541 | /// into the load. For example, consider this code: | ||||
4542 | /// | ||||
4543 | /// X = ... | ||||
4544 | /// Y = X+1 | ||||
4545 | /// use(Y) -> nonload/store | ||||
4546 | /// Z = Y+1 | ||||
4547 | /// load Z | ||||
4548 | /// | ||||
4549 | /// In this case, Y has multiple uses, and can be folded into the load of Z | ||||
4550 | /// (yielding load [X+2]). However, doing this will cause both "X" and "X+1" to | ||||
4551 | /// be live at the use(Y) line. If we don't fold Y into load Z, we use one | ||||
4552 | /// fewer register. Since Y can't be folded into "use(Y)" we don't increase the | ||||
4553 | /// number of computations either. | ||||
4554 | /// | ||||
4555 | /// Note that this (like most of CodeGenPrepare) is just a rough heuristic. If | ||||
4556 | /// X was live across 'load Z' for other reasons, we actually *would* want to | ||||
4557 | /// fold the addressing mode in the Z case. This would make Y die earlier. | ||||
4558 | bool AddressingModeMatcher:: | ||||
4559 | isProfitableToFoldIntoAddressingMode(Instruction *I, ExtAddrMode &AMBefore, | ||||
4560 | ExtAddrMode &AMAfter) { | ||||
4561 | if (IgnoreProfitability) return true; | ||||
4562 | |||||
4563 | // AMBefore is the addressing mode before this instruction was folded into it, | ||||
4564 | // and AMAfter is the addressing mode after the instruction was folded. Get | ||||
4565 | // the set of registers referenced by AMAfter and subtract out those | ||||
4566 | // referenced by AMBefore: this is the set of values which folding in this | ||||
4567 | // address extends the lifetime of. | ||||
4568 | // | ||||
4569 | // Note that there are only two potential values being referenced here, | ||||
4570 | // BaseReg and ScaleReg (global addresses are always available, as are any | ||||
4571 | // folded immediates). | ||||
4572 | Value *BaseReg = AMAfter.BaseReg, *ScaledReg = AMAfter.ScaledReg; | ||||
4573 | |||||
4574 | // If the BaseReg or ScaledReg was referenced by the previous addrmode, their | ||||
4575 | // lifetime wasn't extended by adding this instruction. | ||||
4576 | if (valueAlreadyLiveAtInst(BaseReg, AMBefore.BaseReg, AMBefore.ScaledReg)) | ||||
4577 | BaseReg = nullptr; | ||||
4578 | if (valueAlreadyLiveAtInst(ScaledReg, AMBefore.BaseReg, AMBefore.ScaledReg)) | ||||
4579 | ScaledReg = nullptr; | ||||
4580 | |||||
4581 | // If folding this instruction (and it's subexprs) didn't extend any live | ||||
4582 | // ranges, we're ok with it. | ||||
4583 | if (!BaseReg && !ScaledReg) | ||||
4584 | return true; | ||||
4585 | |||||
4586 | // If all uses of this instruction can have the address mode sunk into them, | ||||
4587 | // we can remove the addressing mode and effectively trade one live register | ||||
4588 | // for another (at worst.) In this context, folding an addressing mode into | ||||
4589 | // the use is just a particularly nice way of sinking it. | ||||
4590 | SmallVector<std::pair<Instruction*,unsigned>, 16> MemoryUses; | ||||
4591 | SmallPtrSet<Instruction*, 16> ConsideredInsts; | ||||
4592 | if (FindAllMemoryUses(I, MemoryUses, ConsideredInsts, TLI, TRI)) | ||||
4593 | return false; // Has a non-memory, non-foldable use! | ||||
4594 | |||||
4595 | // Now that we know that all uses of this instruction are part of a chain of | ||||
4596 | // computation involving only operations that could theoretically be folded | ||||
4597 | // into a memory use, loop over each of these memory operation uses and see | ||||
4598 | // if they could *actually* fold the instruction. The assumption is that | ||||
4599 | // addressing modes are cheap and that duplicating the computation involved | ||||
4600 | // many times is worthwhile, even on a fastpath. For sinking candidates | ||||
4601 | // (i.e. cold call sites), this serves as a way to prevent excessive code | ||||
4602 | // growth since most architectures have some reasonable small and fast way to | ||||
4603 | // compute an effective address. (i.e LEA on x86) | ||||
4604 | SmallVector<Instruction*, 32> MatchedAddrModeInsts; | ||||
4605 | for (unsigned i = 0, e = MemoryUses.size(); i != e; ++i) { | ||||
4606 | Instruction *User = MemoryUses[i].first; | ||||
4607 | unsigned OpNo = MemoryUses[i].second; | ||||
4608 | |||||
4609 | // Get the access type of this use. If the use isn't a pointer, we don't | ||||
4610 | // know what it accesses. | ||||
4611 | Value *Address = User->getOperand(OpNo); | ||||
4612 | PointerType *AddrTy = dyn_cast<PointerType>(Address->getType()); | ||||
4613 | if (!AddrTy) | ||||
4614 | return false; | ||||
4615 | Type *AddressAccessTy = AddrTy->getElementType(); | ||||
4616 | unsigned AS = AddrTy->getAddressSpace(); | ||||
4617 | |||||
4618 | // Do a match against the root of this address, ignoring profitability. This | ||||
4619 | // will tell us if the addressing mode for the memory operation will | ||||
4620 | // *actually* cover the shared instruction. | ||||
4621 | ExtAddrMode Result; | ||||
4622 | std::pair<AssertingVH<GetElementPtrInst>, int64_t> LargeOffsetGEP(nullptr, | ||||
4623 | 0); | ||||
4624 | TypePromotionTransaction::ConstRestorationPt LastKnownGood = | ||||
4625 | TPT.getRestorationPoint(); | ||||
4626 | AddressingModeMatcher Matcher( | ||||
4627 | MatchedAddrModeInsts, TLI, TRI, AddressAccessTy, AS, MemoryInst, Result, | ||||
4628 | InsertedInsts, PromotedInsts, TPT, LargeOffsetGEP); | ||||
4629 | Matcher.IgnoreProfitability = true; | ||||
4630 | bool Success = Matcher.matchAddr(Address, 0); | ||||
4631 | (void)Success; assert(Success && "Couldn't select *anything*?")((Success && "Couldn't select *anything*?") ? static_cast <void> (0) : __assert_fail ("Success && \"Couldn't select *anything*?\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 4631, __PRETTY_FUNCTION__)); | ||||
4632 | |||||
4633 | // The match was to check the profitability, the changes made are not | ||||
4634 | // part of the original matcher. Therefore, they should be dropped | ||||
4635 | // otherwise the original matcher will not present the right state. | ||||
4636 | TPT.rollback(LastKnownGood); | ||||
4637 | |||||
4638 | // If the match didn't cover I, then it won't be shared by it. | ||||
4639 | if (!is_contained(MatchedAddrModeInsts, I)) | ||||
4640 | return false; | ||||
4641 | |||||
4642 | MatchedAddrModeInsts.clear(); | ||||
4643 | } | ||||
4644 | |||||
4645 | return true; | ||||
4646 | } | ||||
4647 | |||||
4648 | /// Return true if the specified values are defined in a | ||||
4649 | /// different basic block than BB. | ||||
4650 | static bool IsNonLocalValue(Value *V, BasicBlock *BB) { | ||||
4651 | if (Instruction *I = dyn_cast<Instruction>(V)) | ||||
4652 | return I->getParent() != BB; | ||||
4653 | return false; | ||||
4654 | } | ||||
4655 | |||||
4656 | /// Sink addressing mode computation immediate before MemoryInst if doing so | ||||
4657 | /// can be done without increasing register pressure. The need for the | ||||
4658 | /// register pressure constraint means this can end up being an all or nothing | ||||
4659 | /// decision for all uses of the same addressing computation. | ||||
4660 | /// | ||||
4661 | /// Load and Store Instructions often have addressing modes that can do | ||||
4662 | /// significant amounts of computation. As such, instruction selection will try | ||||
4663 | /// to get the load or store to do as much computation as possible for the | ||||
4664 | /// program. The problem is that isel can only see within a single block. As | ||||
4665 | /// such, we sink as much legal addressing mode work into the block as possible. | ||||
4666 | /// | ||||
4667 | /// This method is used to optimize both load/store and inline asms with memory | ||||
4668 | /// operands. It's also used to sink addressing computations feeding into cold | ||||
4669 | /// call sites into their (cold) basic block. | ||||
4670 | /// | ||||
4671 | /// The motivation for handling sinking into cold blocks is that doing so can | ||||
4672 | /// both enable other address mode sinking (by satisfying the register pressure | ||||
4673 | /// constraint above), and reduce register pressure globally (by removing the | ||||
4674 | /// addressing mode computation from the fast path entirely.). | ||||
4675 | bool CodeGenPrepare::optimizeMemoryInst(Instruction *MemoryInst, Value *Addr, | ||||
4676 | Type *AccessTy, unsigned AddrSpace) { | ||||
4677 | Value *Repl = Addr; | ||||
4678 | |||||
4679 | // Try to collapse single-value PHI nodes. This is necessary to undo | ||||
4680 | // unprofitable PRE transformations. | ||||
4681 | SmallVector<Value*, 8> worklist; | ||||
4682 | SmallPtrSet<Value*, 16> Visited; | ||||
4683 | worklist.push_back(Addr); | ||||
4684 | |||||
4685 | // Use a worklist to iteratively look through PHI and select nodes, and | ||||
4686 | // ensure that the addressing mode obtained from the non-PHI/select roots of | ||||
4687 | // the graph are compatible. | ||||
4688 | bool PhiOrSelectSeen = false; | ||||
4689 | SmallVector<Instruction*, 16> AddrModeInsts; | ||||
4690 | const SimplifyQuery SQ(*DL, TLInfo); | ||||
4691 | AddressingModeCombiner AddrModes(SQ, Addr); | ||||
4692 | TypePromotionTransaction TPT(RemovedInsts); | ||||
4693 | TypePromotionTransaction::ConstRestorationPt LastKnownGood = | ||||
4694 | TPT.getRestorationPoint(); | ||||
4695 | while (!worklist.empty()) { | ||||
| |||||
4696 | Value *V = worklist.back(); | ||||
4697 | worklist.pop_back(); | ||||
4698 | |||||
4699 | // We allow traversing cyclic Phi nodes. | ||||
4700 | // In case of success after this loop we ensure that traversing through | ||||
4701 | // Phi nodes ends up with all cases to compute address of the form | ||||
4702 | // BaseGV + Base + Scale * Index + Offset | ||||
4703 | // where Scale and Offset are constans and BaseGV, Base and Index | ||||
4704 | // are exactly the same Values in all cases. | ||||
4705 | // It means that BaseGV, Scale and Offset dominate our memory instruction | ||||
4706 | // and have the same value as they had in address computation represented | ||||
4707 | // as Phi. So we can safely sink address computation to memory instruction. | ||||
4708 | if (!Visited.insert(V).second) | ||||
4709 | continue; | ||||
4710 | |||||
4711 | // For a PHI node, push all of its incoming values. | ||||
4712 | if (PHINode *P
| ||||
4713 | for (Value *IncValue : P->incoming_values()) | ||||
4714 | worklist.push_back(IncValue); | ||||
4715 | PhiOrSelectSeen = true; | ||||
4716 | continue; | ||||
4717 | } | ||||
4718 | // Similar for select. | ||||
4719 | if (SelectInst *SI
| ||||
4720 | worklist.push_back(SI->getFalseValue()); | ||||
4721 | worklist.push_back(SI->getTrueValue()); | ||||
4722 | PhiOrSelectSeen = true; | ||||
4723 | continue; | ||||
4724 | } | ||||
4725 | |||||
4726 | // For non-PHIs, determine the addressing mode being computed. Note that | ||||
4727 | // the result may differ depending on what other uses our candidate | ||||
4728 | // addressing instructions might have. | ||||
4729 | AddrModeInsts.clear(); | ||||
4730 | std::pair<AssertingVH<GetElementPtrInst>, int64_t> LargeOffsetGEP(nullptr, | ||||
4731 | 0); | ||||
4732 | ExtAddrMode NewAddrMode = AddressingModeMatcher::Match( | ||||
4733 | V, AccessTy, AddrSpace, MemoryInst, AddrModeInsts, *TLI, *TRI, | ||||
4734 | InsertedInsts, PromotedInsts, TPT, LargeOffsetGEP); | ||||
4735 | |||||
4736 | GetElementPtrInst *GEP = LargeOffsetGEP.first; | ||||
4737 | if (GEP
| ||||
4738 | // If splitting the underlying data structure can reduce the offset of a | ||||
4739 | // GEP, collect the GEP. Skip the GEPs that are the new bases of | ||||
4740 | // previously split data structures. | ||||
4741 | LargeOffsetGEPMap[GEP->getPointerOperand()].push_back(LargeOffsetGEP); | ||||
4742 | if (LargeOffsetGEPID.find(GEP) == LargeOffsetGEPID.end()) | ||||
4743 | LargeOffsetGEPID[GEP] = LargeOffsetGEPID.size(); | ||||
4744 | } | ||||
4745 | |||||
4746 | NewAddrMode.OriginalValue = V; | ||||
4747 | if (!AddrModes.addNewAddrMode(NewAddrMode)) | ||||
4748 | break; | ||||
4749 | } | ||||
4750 | |||||
4751 | // Try to combine the AddrModes we've collected. If we couldn't collect any, | ||||
4752 | // or we have multiple but either couldn't combine them or combining them | ||||
4753 | // wouldn't do anything useful, bail out now. | ||||
4754 | if (!AddrModes.combineAddrModes()) { | ||||
4755 | TPT.rollback(LastKnownGood); | ||||
4756 | return false; | ||||
4757 | } | ||||
4758 | TPT.commit(); | ||||
4759 | |||||
4760 | // Get the combined AddrMode (or the only AddrMode, if we only had one). | ||||
4761 | ExtAddrMode AddrMode = AddrModes.getAddrMode(); | ||||
4762 | |||||
4763 | // If all the instructions matched are already in this BB, don't do anything. | ||||
4764 | // If we saw a Phi node then it is not local definitely, and if we saw a select | ||||
4765 | // then we want to push the address calculation past it even if it's already | ||||
4766 | // in this BB. | ||||
4767 | if (!PhiOrSelectSeen && none_of(AddrModeInsts, [&](Value *V) { | ||||
4768 | return IsNonLocalValue(V, MemoryInst->getParent()); | ||||
4769 | })) { | ||||
4770 | LLVM_DEBUG(dbgs() << "CGP: Found local addrmode: " << AddrModedo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "CGP: Found local addrmode: " << AddrMode << "\n"; } } while (false) | ||||
4771 | << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "CGP: Found local addrmode: " << AddrMode << "\n"; } } while (false); | ||||
4772 | return false; | ||||
4773 | } | ||||
4774 | |||||
4775 | // Insert this computation right after this user. Since our caller is | ||||
4776 | // scanning from the top of the BB to the bottom, reuse of the expr are | ||||
4777 | // guaranteed to happen later. | ||||
4778 | IRBuilder<> Builder(MemoryInst); | ||||
4779 | |||||
4780 | // Now that we determined the addressing expression we want to use and know | ||||
4781 | // that we have to sink it into this block. Check to see if we have already | ||||
4782 | // done this for some other load/store instr in this block. If so, reuse | ||||
4783 | // the computation. Before attempting reuse, check if the address is valid | ||||
4784 | // as it may have been erased. | ||||
4785 | |||||
4786 | WeakTrackingVH SunkAddrVH = SunkAddrs[Addr]; | ||||
4787 | |||||
4788 | Value * SunkAddr = SunkAddrVH.pointsToAliveValue() ? SunkAddrVH : nullptr; | ||||
4789 | if (SunkAddr) { | ||||
4790 | LLVM_DEBUG(dbgs() << "CGP: Reusing nonlocal addrmode: " << AddrModedo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "CGP: Reusing nonlocal addrmode: " << AddrMode << " for " << *MemoryInst << "\n"; } } while (false) | ||||
4791 | << " for " << *MemoryInst << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "CGP: Reusing nonlocal addrmode: " << AddrMode << " for " << *MemoryInst << "\n"; } } while (false); | ||||
4792 | if (SunkAddr->getType() != Addr->getType()) | ||||
4793 | SunkAddr = Builder.CreatePointerCast(SunkAddr, Addr->getType()); | ||||
4794 | } else if (AddrSinkUsingGEPs || (!AddrSinkUsingGEPs.getNumOccurrences() && | ||||
4795 | TM && SubtargetInfo->addrSinkUsingGEPs())) { | ||||
4796 | // By default, we use the GEP-based method when AA is used later. This | ||||
4797 | // prevents new inttoptr/ptrtoint pairs from degrading AA capabilities. | ||||
4798 | LLVM_DEBUG(dbgs() << "CGP: SINKING nonlocal addrmode: " << AddrModedo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "CGP: SINKING nonlocal addrmode: " << AddrMode << " for " << *MemoryInst << "\n"; } } while (false) | ||||
4799 | << " for " << *MemoryInst << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "CGP: SINKING nonlocal addrmode: " << AddrMode << " for " << *MemoryInst << "\n"; } } while (false); | ||||
4800 | Type *IntPtrTy = DL->getIntPtrType(Addr->getType()); | ||||
4801 | Value *ResultPtr = nullptr, *ResultIndex = nullptr; | ||||
4802 | |||||
4803 | // First, find the pointer. | ||||
4804 | if (AddrMode.BaseReg && AddrMode.BaseReg->getType()->isPointerTy()) { | ||||
4805 | ResultPtr = AddrMode.BaseReg; | ||||
4806 | AddrMode.BaseReg = nullptr; | ||||
4807 | } | ||||
4808 | |||||
4809 | if (AddrMode.Scale && AddrMode.ScaledReg->getType()->isPointerTy()) { | ||||
4810 | // We can't add more than one pointer together, nor can we scale a | ||||
4811 | // pointer (both of which seem meaningless). | ||||
4812 | if (ResultPtr || AddrMode.Scale != 1) | ||||
4813 | return false; | ||||
4814 | |||||
4815 | ResultPtr = AddrMode.ScaledReg; | ||||
4816 | AddrMode.Scale = 0; | ||||
4817 | } | ||||
4818 | |||||
4819 | // It is only safe to sign extend the BaseReg if we know that the math | ||||
4820 | // required to create it did not overflow before we extend it. Since | ||||
4821 | // the original IR value was tossed in favor of a constant back when | ||||
4822 | // the AddrMode was created we need to bail out gracefully if widths | ||||
4823 | // do not match instead of extending it. | ||||
4824 | // | ||||
4825 | // (See below for code to add the scale.) | ||||
4826 | if (AddrMode.Scale) { | ||||
4827 | Type *ScaledRegTy = AddrMode.ScaledReg->getType(); | ||||
4828 | if (cast<IntegerType>(IntPtrTy)->getBitWidth() > | ||||
4829 | cast<IntegerType>(ScaledRegTy)->getBitWidth()) | ||||
4830 | return false; | ||||
4831 | } | ||||
4832 | |||||
4833 | if (AddrMode.BaseGV) { | ||||
4834 | if (ResultPtr) | ||||
4835 | return false; | ||||
4836 | |||||
4837 | ResultPtr = AddrMode.BaseGV; | ||||
4838 | } | ||||
4839 | |||||
4840 | // If the real base value actually came from an inttoptr, then the matcher | ||||
4841 | // will look through it and provide only the integer value. In that case, | ||||
4842 | // use it here. | ||||
4843 | if (!DL->isNonIntegralPointerType(Addr->getType())) { | ||||
4844 | if (!ResultPtr && AddrMode.BaseReg) { | ||||
4845 | ResultPtr = Builder.CreateIntToPtr(AddrMode.BaseReg, Addr->getType(), | ||||
4846 | "sunkaddr"); | ||||
4847 | AddrMode.BaseReg = nullptr; | ||||
4848 | } else if (!ResultPtr && AddrMode.Scale == 1) { | ||||
4849 | ResultPtr = Builder.CreateIntToPtr(AddrMode.ScaledReg, Addr->getType(), | ||||
4850 | "sunkaddr"); | ||||
4851 | AddrMode.Scale = 0; | ||||
4852 | } | ||||
4853 | } | ||||
4854 | |||||
4855 | if (!ResultPtr && | ||||
4856 | !AddrMode.BaseReg && !AddrMode.Scale && !AddrMode.BaseOffs) { | ||||
4857 | SunkAddr = Constant::getNullValue(Addr->getType()); | ||||
4858 | } else if (!ResultPtr) { | ||||
4859 | return false; | ||||
4860 | } else { | ||||
4861 | Type *I8PtrTy = | ||||
4862 | Builder.getInt8PtrTy(Addr->getType()->getPointerAddressSpace()); | ||||
4863 | Type *I8Ty = Builder.getInt8Ty(); | ||||
4864 | |||||
4865 | // Start with the base register. Do this first so that subsequent address | ||||
4866 | // matching finds it last, which will prevent it from trying to match it | ||||
4867 | // as the scaled value in case it happens to be a mul. That would be | ||||
4868 | // problematic if we've sunk a different mul for the scale, because then | ||||
4869 | // we'd end up sinking both muls. | ||||
4870 | if (AddrMode.BaseReg) { | ||||
4871 | Value *V = AddrMode.BaseReg; | ||||
4872 | if (V->getType() != IntPtrTy) | ||||
4873 | V = Builder.CreateIntCast(V, IntPtrTy, /*isSigned=*/true, "sunkaddr"); | ||||
4874 | |||||
4875 | ResultIndex = V; | ||||
4876 | } | ||||
4877 | |||||
4878 | // Add the scale value. | ||||
4879 | if (AddrMode.Scale) { | ||||
4880 | Value *V = AddrMode.ScaledReg; | ||||
4881 | if (V->getType() == IntPtrTy) { | ||||
4882 | // done. | ||||
4883 | } else { | ||||
4884 | assert(cast<IntegerType>(IntPtrTy)->getBitWidth() <((cast<IntegerType>(IntPtrTy)->getBitWidth() < cast <IntegerType>(V->getType())->getBitWidth() && "We can't transform if ScaledReg is too narrow") ? static_cast <void> (0) : __assert_fail ("cast<IntegerType>(IntPtrTy)->getBitWidth() < cast<IntegerType>(V->getType())->getBitWidth() && \"We can't transform if ScaledReg is too narrow\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 4886, __PRETTY_FUNCTION__)) | ||||
4885 | cast<IntegerType>(V->getType())->getBitWidth() &&((cast<IntegerType>(IntPtrTy)->getBitWidth() < cast <IntegerType>(V->getType())->getBitWidth() && "We can't transform if ScaledReg is too narrow") ? static_cast <void> (0) : __assert_fail ("cast<IntegerType>(IntPtrTy)->getBitWidth() < cast<IntegerType>(V->getType())->getBitWidth() && \"We can't transform if ScaledReg is too narrow\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 4886, __PRETTY_FUNCTION__)) | ||||
4886 | "We can't transform if ScaledReg is too narrow")((cast<IntegerType>(IntPtrTy)->getBitWidth() < cast <IntegerType>(V->getType())->getBitWidth() && "We can't transform if ScaledReg is too narrow") ? static_cast <void> (0) : __assert_fail ("cast<IntegerType>(IntPtrTy)->getBitWidth() < cast<IntegerType>(V->getType())->getBitWidth() && \"We can't transform if ScaledReg is too narrow\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 4886, __PRETTY_FUNCTION__)); | ||||
4887 | V = Builder.CreateTrunc(V, IntPtrTy, "sunkaddr"); | ||||
4888 | } | ||||
4889 | |||||
4890 | if (AddrMode.Scale != 1) | ||||
4891 | V = Builder.CreateMul(V, ConstantInt::get(IntPtrTy, AddrMode.Scale), | ||||
4892 | "sunkaddr"); | ||||
4893 | if (ResultIndex) | ||||
4894 | ResultIndex = Builder.CreateAdd(ResultIndex, V, "sunkaddr"); | ||||
4895 | else | ||||
4896 | ResultIndex = V; | ||||
4897 | } | ||||
4898 | |||||
4899 | // Add in the Base Offset if present. | ||||
4900 | if (AddrMode.BaseOffs) { | ||||
4901 | Value *V = ConstantInt::get(IntPtrTy, AddrMode.BaseOffs); | ||||
4902 | if (ResultIndex) { | ||||
4903 | // We need to add this separately from the scale above to help with | ||||
4904 | // SDAG consecutive load/store merging. | ||||
4905 | if (ResultPtr->getType() != I8PtrTy) | ||||
4906 | ResultPtr = Builder.CreatePointerCast(ResultPtr, I8PtrTy); | ||||
4907 | ResultPtr = | ||||
4908 | AddrMode.InBounds | ||||
4909 | ? Builder.CreateInBoundsGEP(I8Ty, ResultPtr, ResultIndex, | ||||
4910 | "sunkaddr") | ||||
4911 | : Builder.CreateGEP(I8Ty, ResultPtr, ResultIndex, "sunkaddr"); | ||||
4912 | } | ||||
4913 | |||||
4914 | ResultIndex = V; | ||||
4915 | } | ||||
4916 | |||||
4917 | if (!ResultIndex) { | ||||
4918 | SunkAddr = ResultPtr; | ||||
4919 | } else { | ||||
4920 | if (ResultPtr->getType() != I8PtrTy) | ||||
4921 | ResultPtr = Builder.CreatePointerCast(ResultPtr, I8PtrTy); | ||||
4922 | SunkAddr = | ||||
4923 | AddrMode.InBounds | ||||
4924 | ? Builder.CreateInBoundsGEP(I8Ty, ResultPtr, ResultIndex, | ||||
4925 | "sunkaddr") | ||||
4926 | : Builder.CreateGEP(I8Ty, ResultPtr, ResultIndex, "sunkaddr"); | ||||
4927 | } | ||||
4928 | |||||
4929 | if (SunkAddr->getType() != Addr->getType()) | ||||
4930 | SunkAddr = Builder.CreatePointerCast(SunkAddr, Addr->getType()); | ||||
4931 | } | ||||
4932 | } else { | ||||
4933 | // We'd require a ptrtoint/inttoptr down the line, which we can't do for | ||||
4934 | // non-integral pointers, so in that case bail out now. | ||||
4935 | Type *BaseTy = AddrMode.BaseReg ? AddrMode.BaseReg->getType() : nullptr; | ||||
4936 | Type *ScaleTy = AddrMode.Scale ? AddrMode.ScaledReg->getType() : nullptr; | ||||
4937 | PointerType *BasePtrTy = dyn_cast_or_null<PointerType>(BaseTy); | ||||
4938 | PointerType *ScalePtrTy = dyn_cast_or_null<PointerType>(ScaleTy); | ||||
4939 | if (DL->isNonIntegralPointerType(Addr->getType()) || | ||||
4940 | (BasePtrTy && DL->isNonIntegralPointerType(BasePtrTy)) || | ||||
4941 | (ScalePtrTy && DL->isNonIntegralPointerType(ScalePtrTy)) || | ||||
4942 | (AddrMode.BaseGV && | ||||
4943 | DL->isNonIntegralPointerType(AddrMode.BaseGV->getType()))) | ||||
4944 | return false; | ||||
4945 | |||||
4946 | LLVM_DEBUG(dbgs() << "CGP: SINKING nonlocal addrmode: " << AddrModedo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "CGP: SINKING nonlocal addrmode: " << AddrMode << " for " << *MemoryInst << "\n"; } } while (false) | ||||
4947 | << " for " << *MemoryInst << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "CGP: SINKING nonlocal addrmode: " << AddrMode << " for " << *MemoryInst << "\n"; } } while (false); | ||||
4948 | Type *IntPtrTy = DL->getIntPtrType(Addr->getType()); | ||||
4949 | Value *Result = nullptr; | ||||
4950 | |||||
4951 | // Start with the base register. Do this first so that subsequent address | ||||
4952 | // matching finds it last, which will prevent it from trying to match it | ||||
4953 | // as the scaled value in case it happens to be a mul. That would be | ||||
4954 | // problematic if we've sunk a different mul for the scale, because then | ||||
4955 | // we'd end up sinking both muls. | ||||
4956 | if (AddrMode.BaseReg) { | ||||
4957 | Value *V = AddrMode.BaseReg; | ||||
4958 | if (V->getType()->isPointerTy()) | ||||
4959 | V = Builder.CreatePtrToInt(V, IntPtrTy, "sunkaddr"); | ||||
4960 | if (V->getType() != IntPtrTy) | ||||
4961 | V = Builder.CreateIntCast(V, IntPtrTy, /*isSigned=*/true, "sunkaddr"); | ||||
4962 | Result = V; | ||||
4963 | } | ||||
4964 | |||||
4965 | // Add the scale value. | ||||
4966 | if (AddrMode.Scale) { | ||||
4967 | Value *V = AddrMode.ScaledReg; | ||||
4968 | if (V->getType() == IntPtrTy) { | ||||
4969 | // done. | ||||
4970 | } else if (V->getType()->isPointerTy()) { | ||||
4971 | V = Builder.CreatePtrToInt(V, IntPtrTy, "sunkaddr"); | ||||
4972 | } else if (cast<IntegerType>(IntPtrTy)->getBitWidth() < | ||||
4973 | cast<IntegerType>(V->getType())->getBitWidth()) { | ||||
4974 | V = Builder.CreateTrunc(V, IntPtrTy, "sunkaddr"); | ||||
4975 | } else { | ||||
4976 | // It is only safe to sign extend the BaseReg if we know that the math | ||||
4977 | // required to create it did not overflow before we extend it. Since | ||||
4978 | // the original IR value was tossed in favor of a constant back when | ||||
4979 | // the AddrMode was created we need to bail out gracefully if widths | ||||
4980 | // do not match instead of extending it. | ||||
4981 | Instruction *I = dyn_cast_or_null<Instruction>(Result); | ||||
4982 | if (I && (Result != AddrMode.BaseReg)) | ||||
4983 | I->eraseFromParent(); | ||||
4984 | return false; | ||||
4985 | } | ||||
4986 | if (AddrMode.Scale != 1) | ||||
4987 | V = Builder.CreateMul(V, ConstantInt::get(IntPtrTy, AddrMode.Scale), | ||||
4988 | "sunkaddr"); | ||||
4989 | if (Result) | ||||
4990 | Result = Builder.CreateAdd(Result, V, "sunkaddr"); | ||||
4991 | else | ||||
4992 | Result = V; | ||||
4993 | } | ||||
4994 | |||||
4995 | // Add in the BaseGV if present. | ||||
4996 | if (AddrMode.BaseGV) { | ||||
4997 | Value *V = Builder.CreatePtrToInt(AddrMode.BaseGV, IntPtrTy, "sunkaddr"); | ||||
4998 | if (Result) | ||||
4999 | Result = Builder.CreateAdd(Result, V, "sunkaddr"); | ||||
5000 | else | ||||
5001 | Result = V; | ||||
5002 | } | ||||
5003 | |||||
5004 | // Add in the Base Offset if present. | ||||
5005 | if (AddrMode.BaseOffs) { | ||||
5006 | Value *V = ConstantInt::get(IntPtrTy, AddrMode.BaseOffs); | ||||
5007 | if (Result) | ||||
5008 | Result = Builder.CreateAdd(Result, V, "sunkaddr"); | ||||
5009 | else | ||||
5010 | Result = V; | ||||
5011 | } | ||||
5012 | |||||
5013 | if (!Result) | ||||
5014 | SunkAddr = Constant::getNullValue(Addr->getType()); | ||||
5015 | else | ||||
5016 | SunkAddr = Builder.CreateIntToPtr(Result, Addr->getType(), "sunkaddr"); | ||||
5017 | } | ||||
5018 | |||||
5019 | MemoryInst->replaceUsesOfWith(Repl, SunkAddr); | ||||
5020 | // Store the newly computed address into the cache. In the case we reused a | ||||
5021 | // value, this should be idempotent. | ||||
5022 | SunkAddrs[Addr] = WeakTrackingVH(SunkAddr); | ||||
5023 | |||||
5024 | // If we have no uses, recursively delete the value and all dead instructions | ||||
5025 | // using it. | ||||
5026 | if (Repl->use_empty()) { | ||||
5027 | // This can cause recursive deletion, which can invalidate our iterator. | ||||
5028 | // Use a WeakTrackingVH to hold onto it in case this happens. | ||||
5029 | Value *CurValue = &*CurInstIterator; | ||||
5030 | WeakTrackingVH IterHandle(CurValue); | ||||
5031 | BasicBlock *BB = CurInstIterator->getParent(); | ||||
5032 | |||||
5033 | RecursivelyDeleteTriviallyDeadInstructions(Repl, TLInfo); | ||||
5034 | |||||
5035 | if (IterHandle != CurValue) { | ||||
5036 | // If the iterator instruction was recursively deleted, start over at the | ||||
5037 | // start of the block. | ||||
5038 | CurInstIterator = BB->begin(); | ||||
5039 | SunkAddrs.clear(); | ||||
5040 | } | ||||
5041 | } | ||||
5042 | ++NumMemoryInsts; | ||||
5043 | return true; | ||||
5044 | } | ||||
5045 | |||||
5046 | /// If there are any memory operands, use OptimizeMemoryInst to sink their | ||||
5047 | /// address computing into the block when possible / profitable. | ||||
5048 | bool CodeGenPrepare::optimizeInlineAsmInst(CallInst *CS) { | ||||
5049 | bool MadeChange = false; | ||||
5050 | |||||
5051 | const TargetRegisterInfo *TRI = | ||||
5052 | TM->getSubtargetImpl(*CS->getFunction())->getRegisterInfo(); | ||||
5053 | TargetLowering::AsmOperandInfoVector TargetConstraints = | ||||
5054 | TLI->ParseConstraints(*DL, TRI, CS); | ||||
5055 | unsigned ArgNo = 0; | ||||
5056 | for (unsigned i = 0, e = TargetConstraints.size(); i != e; ++i) { | ||||
5057 | TargetLowering::AsmOperandInfo &OpInfo = TargetConstraints[i]; | ||||
5058 | |||||
5059 | // Compute the constraint code and ConstraintType to use. | ||||
5060 | TLI->ComputeConstraintToUse(OpInfo, SDValue()); | ||||
5061 | |||||
5062 | if (OpInfo.ConstraintType == TargetLowering::C_Memory && | ||||
5063 | OpInfo.isIndirect) { | ||||
5064 | Value *OpVal = CS->getArgOperand(ArgNo++); | ||||
5065 | MadeChange |= optimizeMemoryInst(CS, OpVal, OpVal->getType(), ~0u); | ||||
5066 | } else if (OpInfo.Type == InlineAsm::isInput) | ||||
5067 | ArgNo++; | ||||
5068 | } | ||||
5069 | |||||
5070 | return MadeChange; | ||||
5071 | } | ||||
5072 | |||||
5073 | /// Check if all the uses of \p Val are equivalent (or free) zero or | ||||
5074 | /// sign extensions. | ||||
5075 | static bool hasSameExtUse(Value *Val, const TargetLowering &TLI) { | ||||
5076 | assert(!Val->use_empty() && "Input must have at least one use")((!Val->use_empty() && "Input must have at least one use" ) ? static_cast<void> (0) : __assert_fail ("!Val->use_empty() && \"Input must have at least one use\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 5076, __PRETTY_FUNCTION__)); | ||||
5077 | const Instruction *FirstUser = cast<Instruction>(*Val->user_begin()); | ||||
5078 | bool IsSExt = isa<SExtInst>(FirstUser); | ||||
5079 | Type *ExtTy = FirstUser->getType(); | ||||
5080 | for (const User *U : Val->users()) { | ||||
5081 | const Instruction *UI = cast<Instruction>(U); | ||||
5082 | if ((IsSExt && !isa<SExtInst>(UI)) || (!IsSExt && !isa<ZExtInst>(UI))) | ||||
5083 | return false; | ||||
5084 | Type *CurTy = UI->getType(); | ||||
5085 | // Same input and output types: Same instruction after CSE. | ||||
5086 | if (CurTy == ExtTy) | ||||
5087 | continue; | ||||
5088 | |||||
5089 | // If IsSExt is true, we are in this situation: | ||||
5090 | // a = Val | ||||
5091 | // b = sext ty1 a to ty2 | ||||
5092 | // c = sext ty1 a to ty3 | ||||
5093 | // Assuming ty2 is shorter than ty3, this could be turned into: | ||||
5094 | // a = Val | ||||
5095 | // b = sext ty1 a to ty2 | ||||
5096 | // c = sext ty2 b to ty3 | ||||
5097 | // However, the last sext is not free. | ||||
5098 | if (IsSExt) | ||||
5099 | return false; | ||||
5100 | |||||
5101 | // This is a ZExt, maybe this is free to extend from one type to another. | ||||
5102 | // In that case, we would not account for a different use. | ||||
5103 | Type *NarrowTy; | ||||
5104 | Type *LargeTy; | ||||
5105 | if (ExtTy->getScalarType()->getIntegerBitWidth() > | ||||
5106 | CurTy->getScalarType()->getIntegerBitWidth()) { | ||||
5107 | NarrowTy = CurTy; | ||||
5108 | LargeTy = ExtTy; | ||||
5109 | } else { | ||||
5110 | NarrowTy = ExtTy; | ||||
5111 | LargeTy = CurTy; | ||||
5112 | } | ||||
5113 | |||||
5114 | if (!TLI.isZExtFree(NarrowTy, LargeTy)) | ||||
5115 | return false; | ||||
5116 | } | ||||
5117 | // All uses are the same or can be derived from one another for free. | ||||
5118 | return true; | ||||
5119 | } | ||||
5120 | |||||
5121 | /// Try to speculatively promote extensions in \p Exts and continue | ||||
5122 | /// promoting through newly promoted operands recursively as far as doing so is | ||||
5123 | /// profitable. Save extensions profitably moved up, in \p ProfitablyMovedExts. | ||||
5124 | /// When some promotion happened, \p TPT contains the proper state to revert | ||||
5125 | /// them. | ||||
5126 | /// | ||||
5127 | /// \return true if some promotion happened, false otherwise. | ||||
5128 | bool CodeGenPrepare::tryToPromoteExts( | ||||
5129 | TypePromotionTransaction &TPT, const SmallVectorImpl<Instruction *> &Exts, | ||||
5130 | SmallVectorImpl<Instruction *> &ProfitablyMovedExts, | ||||
5131 | unsigned CreatedInstsCost) { | ||||
5132 | bool Promoted = false; | ||||
5133 | |||||
5134 | // Iterate over all the extensions to try to promote them. | ||||
5135 | for (auto I : Exts) { | ||||
5136 | // Early check if we directly have ext(load). | ||||
5137 | if (isa<LoadInst>(I->getOperand(0))) { | ||||
5138 | ProfitablyMovedExts.push_back(I); | ||||
5139 | continue; | ||||
5140 | } | ||||
5141 | |||||
5142 | // Check whether or not we want to do any promotion. The reason we have | ||||
5143 | // this check inside the for loop is to catch the case where an extension | ||||
5144 | // is directly fed by a load because in such case the extension can be moved | ||||
5145 | // up without any promotion on its operands. | ||||
5146 | if (!TLI || !TLI->enableExtLdPromotion() || DisableExtLdPromotion) | ||||
5147 | return false; | ||||
5148 | |||||
5149 | // Get the action to perform the promotion. | ||||
5150 | TypePromotionHelper::Action TPH = | ||||
5151 | TypePromotionHelper::getAction(I, InsertedInsts, *TLI, PromotedInsts); | ||||
5152 | // Check if we can promote. | ||||
5153 | if (!TPH) { | ||||
5154 | // Save the current extension as we cannot move up through its operand. | ||||
5155 | ProfitablyMovedExts.push_back(I); | ||||
5156 | continue; | ||||
5157 | } | ||||
5158 | |||||
5159 | // Save the current state. | ||||
5160 | TypePromotionTransaction::ConstRestorationPt LastKnownGood = | ||||
5161 | TPT.getRestorationPoint(); | ||||
5162 | SmallVector<Instruction *, 4> NewExts; | ||||
5163 | unsigned NewCreatedInstsCost = 0; | ||||
5164 | unsigned ExtCost = !TLI->isExtFree(I); | ||||
5165 | // Promote. | ||||
5166 | Value *PromotedVal = TPH(I, TPT, PromotedInsts, NewCreatedInstsCost, | ||||
5167 | &NewExts, nullptr, *TLI); | ||||
5168 | assert(PromotedVal &&((PromotedVal && "TypePromotionHelper should have filtered out those cases" ) ? static_cast<void> (0) : __assert_fail ("PromotedVal && \"TypePromotionHelper should have filtered out those cases\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 5169, __PRETTY_FUNCTION__)) | ||||
5169 | "TypePromotionHelper should have filtered out those cases")((PromotedVal && "TypePromotionHelper should have filtered out those cases" ) ? static_cast<void> (0) : __assert_fail ("PromotedVal && \"TypePromotionHelper should have filtered out those cases\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 5169, __PRETTY_FUNCTION__)); | ||||
5170 | |||||
5171 | // We would be able to merge only one extension in a load. | ||||
5172 | // Therefore, if we have more than 1 new extension we heuristically | ||||
5173 | // cut this search path, because it means we degrade the code quality. | ||||
5174 | // With exactly 2, the transformation is neutral, because we will merge | ||||
5175 | // one extension but leave one. However, we optimistically keep going, | ||||
5176 | // because the new extension may be removed too. | ||||
5177 | long long TotalCreatedInstsCost = CreatedInstsCost + NewCreatedInstsCost; | ||||
5178 | // FIXME: It would be possible to propagate a negative value instead of | ||||
5179 | // conservatively ceiling it to 0. | ||||
5180 | TotalCreatedInstsCost = | ||||
5181 | std::max((long long)0, (TotalCreatedInstsCost - ExtCost)); | ||||
5182 | if (!StressExtLdPromotion && | ||||
5183 | (TotalCreatedInstsCost > 1 || | ||||
5184 | !isPromotedInstructionLegal(*TLI, *DL, PromotedVal))) { | ||||
5185 | // This promotion is not profitable, rollback to the previous state, and | ||||
5186 | // save the current extension in ProfitablyMovedExts as the latest | ||||
5187 | // speculative promotion turned out to be unprofitable. | ||||
5188 | TPT.rollback(LastKnownGood); | ||||
5189 | ProfitablyMovedExts.push_back(I); | ||||
5190 | continue; | ||||
5191 | } | ||||
5192 | // Continue promoting NewExts as far as doing so is profitable. | ||||
5193 | SmallVector<Instruction *, 2> NewlyMovedExts; | ||||
5194 | (void)tryToPromoteExts(TPT, NewExts, NewlyMovedExts, TotalCreatedInstsCost); | ||||
5195 | bool NewPromoted = false; | ||||
5196 | for (auto ExtInst : NewlyMovedExts) { | ||||
5197 | Instruction *MovedExt = cast<Instruction>(ExtInst); | ||||
5198 | Value *ExtOperand = MovedExt->getOperand(0); | ||||
5199 | // If we have reached to a load, we need this extra profitability check | ||||
5200 | // as it could potentially be merged into an ext(load). | ||||
5201 | if (isa<LoadInst>(ExtOperand) && | ||||
5202 | !(StressExtLdPromotion || NewCreatedInstsCost <= ExtCost || | ||||
5203 | (ExtOperand->hasOneUse() || hasSameExtUse(ExtOperand, *TLI)))) | ||||
5204 | continue; | ||||
5205 | |||||
5206 | ProfitablyMovedExts.push_back(MovedExt); | ||||
5207 | NewPromoted = true; | ||||
5208 | } | ||||
5209 | |||||
5210 | // If none of speculative promotions for NewExts is profitable, rollback | ||||
5211 | // and save the current extension (I) as the last profitable extension. | ||||
5212 | if (!NewPromoted) { | ||||
5213 | TPT.rollback(LastKnownGood); | ||||
5214 | ProfitablyMovedExts.push_back(I); | ||||
5215 | continue; | ||||
5216 | } | ||||
5217 | // The promotion is profitable. | ||||
5218 | Promoted = true; | ||||
5219 | } | ||||
5220 | return Promoted; | ||||
5221 | } | ||||
5222 | |||||
5223 | /// Merging redundant sexts when one is dominating the other. | ||||
5224 | bool CodeGenPrepare::mergeSExts(Function &F) { | ||||
5225 | bool Changed = false; | ||||
5226 | for (auto &Entry : ValToSExtendedUses) { | ||||
5227 | SExts &Insts = Entry.second; | ||||
5228 | SExts CurPts; | ||||
5229 | for (Instruction *Inst : Insts) { | ||||
5230 | if (RemovedInsts.count(Inst) || !isa<SExtInst>(Inst) || | ||||
5231 | Inst->getOperand(0) != Entry.first) | ||||
5232 | continue; | ||||
5233 | bool inserted = false; | ||||
5234 | for (auto &Pt : CurPts) { | ||||
5235 | if (getDT(F).dominates(Inst, Pt)) { | ||||
5236 | Pt->replaceAllUsesWith(Inst); | ||||
5237 | RemovedInsts.insert(Pt); | ||||
5238 | Pt->removeFromParent(); | ||||
5239 | Pt = Inst; | ||||
5240 | inserted = true; | ||||
5241 | Changed = true; | ||||
5242 | break; | ||||
5243 | } | ||||
5244 | if (!getDT(F).dominates(Pt, Inst)) | ||||
5245 | // Give up if we need to merge in a common dominator as the | ||||
5246 | // experiments show it is not profitable. | ||||
5247 | continue; | ||||
5248 | Inst->replaceAllUsesWith(Pt); | ||||
5249 | RemovedInsts.insert(Inst); | ||||
5250 | Inst->removeFromParent(); | ||||
5251 | inserted = true; | ||||
5252 | Changed = true; | ||||
5253 | break; | ||||
5254 | } | ||||
5255 | if (!inserted) | ||||
5256 | CurPts.push_back(Inst); | ||||
5257 | } | ||||
5258 | } | ||||
5259 | return Changed; | ||||
5260 | } | ||||
5261 | |||||
5262 | // Spliting large data structures so that the GEPs accessing them can have | ||||
5263 | // smaller offsets so that they can be sunk to the same blocks as their users. | ||||
5264 | // For example, a large struct starting from %base is splitted into two parts | ||||
5265 | // where the second part starts from %new_base. | ||||
5266 | // | ||||
5267 | // Before: | ||||
5268 | // BB0: | ||||
5269 | // %base = | ||||
5270 | // | ||||
5271 | // BB1: | ||||
5272 | // %gep0 = gep %base, off0 | ||||
5273 | // %gep1 = gep %base, off1 | ||||
5274 | // %gep2 = gep %base, off2 | ||||
5275 | // | ||||
5276 | // BB2: | ||||
5277 | // %load1 = load %gep0 | ||||
5278 | // %load2 = load %gep1 | ||||
5279 | // %load3 = load %gep2 | ||||
5280 | // | ||||
5281 | // After: | ||||
5282 | // BB0: | ||||
5283 | // %base = | ||||
5284 | // %new_base = gep %base, off0 | ||||
5285 | // | ||||
5286 | // BB1: | ||||
5287 | // %new_gep0 = %new_base | ||||
5288 | // %new_gep1 = gep %new_base, off1 - off0 | ||||
5289 | // %new_gep2 = gep %new_base, off2 - off0 | ||||
5290 | // | ||||
5291 | // BB2: | ||||
5292 | // %load1 = load i32, i32* %new_gep0 | ||||
5293 | // %load2 = load i32, i32* %new_gep1 | ||||
5294 | // %load3 = load i32, i32* %new_gep2 | ||||
5295 | // | ||||
5296 | // %new_gep1 and %new_gep2 can be sunk to BB2 now after the splitting because | ||||
5297 | // their offsets are smaller enough to fit into the addressing mode. | ||||
5298 | bool CodeGenPrepare::splitLargeGEPOffsets() { | ||||
5299 | bool Changed = false; | ||||
5300 | for (auto &Entry : LargeOffsetGEPMap) { | ||||
5301 | Value *OldBase = Entry.first; | ||||
5302 | SmallVectorImpl<std::pair<AssertingVH<GetElementPtrInst>, int64_t>> | ||||
5303 | &LargeOffsetGEPs = Entry.second; | ||||
5304 | auto compareGEPOffset = | ||||
5305 | [&](const std::pair<GetElementPtrInst *, int64_t> &LHS, | ||||
5306 | const std::pair<GetElementPtrInst *, int64_t> &RHS) { | ||||
5307 | if (LHS.first == RHS.first) | ||||
5308 | return false; | ||||
5309 | if (LHS.second != RHS.second) | ||||
5310 | return LHS.second < RHS.second; | ||||
5311 | return LargeOffsetGEPID[LHS.first] < LargeOffsetGEPID[RHS.first]; | ||||
5312 | }; | ||||
5313 | // Sorting all the GEPs of the same data structures based on the offsets. | ||||
5314 | llvm::sort(LargeOffsetGEPs, compareGEPOffset); | ||||
5315 | LargeOffsetGEPs.erase( | ||||
5316 | std::unique(LargeOffsetGEPs.begin(), LargeOffsetGEPs.end()), | ||||
5317 | LargeOffsetGEPs.end()); | ||||
5318 | // Skip if all the GEPs have the same offsets. | ||||
5319 | if (LargeOffsetGEPs.front().second == LargeOffsetGEPs.back().second) | ||||
5320 | continue; | ||||
5321 | GetElementPtrInst *BaseGEP = LargeOffsetGEPs.begin()->first; | ||||
5322 | int64_t BaseOffset = LargeOffsetGEPs.begin()->second; | ||||
5323 | Value *NewBaseGEP = nullptr; | ||||
5324 | |||||
5325 | auto LargeOffsetGEP = LargeOffsetGEPs.begin(); | ||||
5326 | while (LargeOffsetGEP != LargeOffsetGEPs.end()) { | ||||
5327 | GetElementPtrInst *GEP = LargeOffsetGEP->first; | ||||
5328 | int64_t Offset = LargeOffsetGEP->second; | ||||
5329 | if (Offset != BaseOffset) { | ||||
5330 | TargetLowering::AddrMode AddrMode; | ||||
5331 | AddrMode.BaseOffs = Offset - BaseOffset; | ||||
5332 | // The result type of the GEP might not be the type of the memory | ||||
5333 | // access. | ||||
5334 | if (!TLI->isLegalAddressingMode(*DL, AddrMode, | ||||
5335 | GEP->getResultElementType(), | ||||
5336 | GEP->getAddressSpace())) { | ||||
5337 | // We need to create a new base if the offset to the current base is | ||||
5338 | // too large to fit into the addressing mode. So, a very large struct | ||||
5339 | // may be splitted into several parts. | ||||
5340 | BaseGEP = GEP; | ||||
5341 | BaseOffset = Offset; | ||||
5342 | NewBaseGEP = nullptr; | ||||
5343 | } | ||||
5344 | } | ||||
5345 | |||||
5346 | // Generate a new GEP to replace the current one. | ||||
5347 | LLVMContext &Ctx = GEP->getContext(); | ||||
5348 | Type *IntPtrTy = DL->getIntPtrType(GEP->getType()); | ||||
5349 | Type *I8PtrTy = | ||||
5350 | Type::getInt8PtrTy(Ctx, GEP->getType()->getPointerAddressSpace()); | ||||
5351 | Type *I8Ty = Type::getInt8Ty(Ctx); | ||||
5352 | |||||
5353 | if (!NewBaseGEP) { | ||||
5354 | // Create a new base if we don't have one yet. Find the insertion | ||||
5355 | // pointer for the new base first. | ||||
5356 | BasicBlock::iterator NewBaseInsertPt; | ||||
5357 | BasicBlock *NewBaseInsertBB; | ||||
5358 | if (auto *BaseI = dyn_cast<Instruction>(OldBase)) { | ||||
5359 | // If the base of the struct is an instruction, the new base will be | ||||
5360 | // inserted close to it. | ||||
5361 | NewBaseInsertBB = BaseI->getParent(); | ||||
5362 | if (isa<PHINode>(BaseI)) | ||||
5363 | NewBaseInsertPt = NewBaseInsertBB->getFirstInsertionPt(); | ||||
5364 | else if (InvokeInst *Invoke = dyn_cast<InvokeInst>(BaseI)) { | ||||
5365 | NewBaseInsertBB = | ||||
5366 | SplitEdge(NewBaseInsertBB, Invoke->getNormalDest()); | ||||
5367 | NewBaseInsertPt = NewBaseInsertBB->getFirstInsertionPt(); | ||||
5368 | } else | ||||
5369 | NewBaseInsertPt = std::next(BaseI->getIterator()); | ||||
5370 | } else { | ||||
5371 | // If the current base is an argument or global value, the new base | ||||
5372 | // will be inserted to the entry block. | ||||
5373 | NewBaseInsertBB = &BaseGEP->getFunction()->getEntryBlock(); | ||||
5374 | NewBaseInsertPt = NewBaseInsertBB->getFirstInsertionPt(); | ||||
5375 | } | ||||
5376 | IRBuilder<> NewBaseBuilder(NewBaseInsertBB, NewBaseInsertPt); | ||||
5377 | // Create a new base. | ||||
5378 | Value *BaseIndex = ConstantInt::get(IntPtrTy, BaseOffset); | ||||
5379 | NewBaseGEP = OldBase; | ||||
5380 | if (NewBaseGEP->getType() != I8PtrTy) | ||||
5381 | NewBaseGEP = NewBaseBuilder.CreatePointerCast(NewBaseGEP, I8PtrTy); | ||||
5382 | NewBaseGEP = | ||||
5383 | NewBaseBuilder.CreateGEP(I8Ty, NewBaseGEP, BaseIndex, "splitgep"); | ||||
5384 | NewGEPBases.insert(NewBaseGEP); | ||||
5385 | } | ||||
5386 | |||||
5387 | IRBuilder<> Builder(GEP); | ||||
5388 | Value *NewGEP = NewBaseGEP; | ||||
5389 | if (Offset == BaseOffset) { | ||||
5390 | if (GEP->getType() != I8PtrTy) | ||||
5391 | NewGEP = Builder.CreatePointerCast(NewGEP, GEP->getType()); | ||||
5392 | } else { | ||||
5393 | // Calculate the new offset for the new GEP. | ||||
5394 | Value *Index = ConstantInt::get(IntPtrTy, Offset - BaseOffset); | ||||
5395 | NewGEP = Builder.CreateGEP(I8Ty, NewBaseGEP, Index); | ||||
5396 | |||||
5397 | if (GEP->getType() != I8PtrTy) | ||||
5398 | NewGEP = Builder.CreatePointerCast(NewGEP, GEP->getType()); | ||||
5399 | } | ||||
5400 | GEP->replaceAllUsesWith(NewGEP); | ||||
5401 | LargeOffsetGEPID.erase(GEP); | ||||
5402 | LargeOffsetGEP = LargeOffsetGEPs.erase(LargeOffsetGEP); | ||||
5403 | GEP->eraseFromParent(); | ||||
5404 | Changed = true; | ||||
5405 | } | ||||
5406 | } | ||||
5407 | return Changed; | ||||
5408 | } | ||||
5409 | |||||
5410 | /// Return true, if an ext(load) can be formed from an extension in | ||||
5411 | /// \p MovedExts. | ||||
5412 | bool CodeGenPrepare::canFormExtLd( | ||||
5413 | const SmallVectorImpl<Instruction *> &MovedExts, LoadInst *&LI, | ||||
5414 | Instruction *&Inst, bool HasPromoted) { | ||||
5415 | for (auto *MovedExtInst : MovedExts) { | ||||
5416 | if (isa<LoadInst>(MovedExtInst->getOperand(0))) { | ||||
5417 | LI = cast<LoadInst>(MovedExtInst->getOperand(0)); | ||||
5418 | Inst = MovedExtInst; | ||||
5419 | break; | ||||
5420 | } | ||||
5421 | } | ||||
5422 | if (!LI) | ||||
5423 | return false; | ||||
5424 | |||||
5425 | // If they're already in the same block, there's nothing to do. | ||||
5426 | // Make the cheap checks first if we did not promote. | ||||
5427 | // If we promoted, we need to check if it is indeed profitable. | ||||
5428 | if (!HasPromoted && LI->getParent() == Inst->getParent()) | ||||
5429 | return false; | ||||
5430 | |||||
5431 | return TLI->isExtLoad(LI, Inst, *DL); | ||||
5432 | } | ||||
5433 | |||||
5434 | /// Move a zext or sext fed by a load into the same basic block as the load, | ||||
5435 | /// unless conditions are unfavorable. This allows SelectionDAG to fold the | ||||
5436 | /// extend into the load. | ||||
5437 | /// | ||||
5438 | /// E.g., | ||||
5439 | /// \code | ||||
5440 | /// %ld = load i32* %addr | ||||
5441 | /// %add = add nuw i32 %ld, 4 | ||||
5442 | /// %zext = zext i32 %add to i64 | ||||
5443 | // \endcode | ||||
5444 | /// => | ||||
5445 | /// \code | ||||
5446 | /// %ld = load i32* %addr | ||||
5447 | /// %zext = zext i32 %ld to i64 | ||||
5448 | /// %add = add nuw i64 %zext, 4 | ||||
5449 | /// \encode | ||||
5450 | /// Note that the promotion in %add to i64 is done in tryToPromoteExts(), which | ||||
5451 | /// allow us to match zext(load i32*) to i64. | ||||
5452 | /// | ||||
5453 | /// Also, try to promote the computations used to obtain a sign extended | ||||
5454 | /// value used into memory accesses. | ||||
5455 | /// E.g., | ||||
5456 | /// \code | ||||
5457 | /// a = add nsw i32 b, 3 | ||||
5458 | /// d = sext i32 a to i64 | ||||
5459 | /// e = getelementptr ..., i64 d | ||||
5460 | /// \endcode | ||||
5461 | /// => | ||||
5462 | /// \code | ||||
5463 | /// f = sext i32 b to i64 | ||||
5464 | /// a = add nsw i64 f, 3 | ||||
5465 | /// e = getelementptr ..., i64 a | ||||
5466 | /// \endcode | ||||
5467 | /// | ||||
5468 | /// \p Inst[in/out] the extension may be modified during the process if some | ||||
5469 | /// promotions apply. | ||||
5470 | bool CodeGenPrepare::optimizeExt(Instruction *&Inst) { | ||||
5471 | // ExtLoad formation and address type promotion infrastructure requires TLI to | ||||
5472 | // be effective. | ||||
5473 | if (!TLI) | ||||
5474 | return false; | ||||
5475 | |||||
5476 | bool AllowPromotionWithoutCommonHeader = false; | ||||
5477 | /// See if it is an interesting sext operations for the address type | ||||
5478 | /// promotion before trying to promote it, e.g., the ones with the right | ||||
5479 | /// type and used in memory accesses. | ||||
5480 | bool ATPConsiderable = TTI->shouldConsiderAddressTypePromotion( | ||||
5481 | *Inst, AllowPromotionWithoutCommonHeader); | ||||
5482 | TypePromotionTransaction TPT(RemovedInsts); | ||||
5483 | TypePromotionTransaction::ConstRestorationPt LastKnownGood = | ||||
5484 | TPT.getRestorationPoint(); | ||||
5485 | SmallVector<Instruction *, 1> Exts; | ||||
5486 | SmallVector<Instruction *, 2> SpeculativelyMovedExts; | ||||
5487 | Exts.push_back(Inst); | ||||
5488 | |||||
5489 | bool HasPromoted = tryToPromoteExts(TPT, Exts, SpeculativelyMovedExts); | ||||
5490 | |||||
5491 | // Look for a load being extended. | ||||
5492 | LoadInst *LI = nullptr; | ||||
5493 | Instruction *ExtFedByLoad; | ||||
5494 | |||||
5495 | // Try to promote a chain of computation if it allows to form an extended | ||||
5496 | // load. | ||||
5497 | if (canFormExtLd(SpeculativelyMovedExts, LI, ExtFedByLoad, HasPromoted)) { | ||||
5498 | assert(LI && ExtFedByLoad && "Expect a valid load and extension")((LI && ExtFedByLoad && "Expect a valid load and extension" ) ? static_cast<void> (0) : __assert_fail ("LI && ExtFedByLoad && \"Expect a valid load and extension\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 5498, __PRETTY_FUNCTION__)); | ||||
5499 | TPT.commit(); | ||||
5500 | // Move the extend into the same block as the load | ||||
5501 | ExtFedByLoad->moveAfter(LI); | ||||
5502 | // CGP does not check if the zext would be speculatively executed when moved | ||||
5503 | // to the same basic block as the load. Preserving its original location | ||||
5504 | // would pessimize the debugging experience, as well as negatively impact | ||||
5505 | // the quality of sample pgo. We don't want to use "line 0" as that has a | ||||
5506 | // size cost in the line-table section and logically the zext can be seen as | ||||
5507 | // part of the load. Therefore we conservatively reuse the same debug | ||||
5508 | // location for the load and the zext. | ||||
5509 | ExtFedByLoad->setDebugLoc(LI->getDebugLoc()); | ||||
5510 | ++NumExtsMoved; | ||||
5511 | Inst = ExtFedByLoad; | ||||
5512 | return true; | ||||
5513 | } | ||||
5514 | |||||
5515 | // Continue promoting SExts if known as considerable depending on targets. | ||||
5516 | if (ATPConsiderable && | ||||
5517 | performAddressTypePromotion(Inst, AllowPromotionWithoutCommonHeader, | ||||
5518 | HasPromoted, TPT, SpeculativelyMovedExts)) | ||||
5519 | return true; | ||||
5520 | |||||
5521 | TPT.rollback(LastKnownGood); | ||||
5522 | return false; | ||||
5523 | } | ||||
5524 | |||||
5525 | // Perform address type promotion if doing so is profitable. | ||||
5526 | // If AllowPromotionWithoutCommonHeader == false, we should find other sext | ||||
5527 | // instructions that sign extended the same initial value. However, if | ||||
5528 | // AllowPromotionWithoutCommonHeader == true, we expect promoting the | ||||
5529 | // extension is just profitable. | ||||
5530 | bool CodeGenPrepare::performAddressTypePromotion( | ||||
5531 | Instruction *&Inst, bool AllowPromotionWithoutCommonHeader, | ||||
5532 | bool HasPromoted, TypePromotionTransaction &TPT, | ||||
5533 | SmallVectorImpl<Instruction *> &SpeculativelyMovedExts) { | ||||
5534 | bool Promoted = false; | ||||
5535 | SmallPtrSet<Instruction *, 1> UnhandledExts; | ||||
5536 | bool AllSeenFirst = true; | ||||
5537 | for (auto I : SpeculativelyMovedExts) { | ||||
5538 | Value *HeadOfChain = I->getOperand(0); | ||||
5539 | DenseMap<Value *, Instruction *>::iterator AlreadySeen = | ||||
5540 | SeenChainsForSExt.find(HeadOfChain); | ||||
5541 | // If there is an unhandled SExt which has the same header, try to promote | ||||
5542 | // it as well. | ||||
5543 | if (AlreadySeen != SeenChainsForSExt.end()) { | ||||
5544 | if (AlreadySeen->second != nullptr) | ||||
5545 | UnhandledExts.insert(AlreadySeen->second); | ||||
5546 | AllSeenFirst = false; | ||||
5547 | } | ||||
5548 | } | ||||
5549 | |||||
5550 | if (!AllSeenFirst || (AllowPromotionWithoutCommonHeader && | ||||
5551 | SpeculativelyMovedExts.size() == 1)) { | ||||
5552 | TPT.commit(); | ||||
5553 | if (HasPromoted) | ||||
5554 | Promoted = true; | ||||
5555 | for (auto I : SpeculativelyMovedExts) { | ||||
5556 | Value *HeadOfChain = I->getOperand(0); | ||||
5557 | SeenChainsForSExt[HeadOfChain] = nullptr; | ||||
5558 | ValToSExtendedUses[HeadOfChain].push_back(I); | ||||
5559 | } | ||||
5560 | // Update Inst as promotion happen. | ||||
5561 | Inst = SpeculativelyMovedExts.pop_back_val(); | ||||
5562 | } else { | ||||
5563 | // This is the first chain visited from the header, keep the current chain | ||||
5564 | // as unhandled. Defer to promote this until we encounter another SExt | ||||
5565 | // chain derived from the same header. | ||||
5566 | for (auto I : SpeculativelyMovedExts) { | ||||
5567 | Value *HeadOfChain = I->getOperand(0); | ||||
5568 | SeenChainsForSExt[HeadOfChain] = Inst; | ||||
5569 | } | ||||
5570 | return false; | ||||
5571 | } | ||||
5572 | |||||
5573 | if (!AllSeenFirst && !UnhandledExts.empty()) | ||||
5574 | for (auto VisitedSExt : UnhandledExts) { | ||||
5575 | if (RemovedInsts.count(VisitedSExt)) | ||||
5576 | continue; | ||||
5577 | TypePromotionTransaction TPT(RemovedInsts); | ||||
5578 | SmallVector<Instruction *, 1> Exts; | ||||
5579 | SmallVector<Instruction *, 2> Chains; | ||||
5580 | Exts.push_back(VisitedSExt); | ||||
5581 | bool HasPromoted = tryToPromoteExts(TPT, Exts, Chains); | ||||
5582 | TPT.commit(); | ||||
5583 | if (HasPromoted) | ||||
5584 | Promoted = true; | ||||
5585 | for (auto I : Chains) { | ||||
5586 | Value *HeadOfChain = I->getOperand(0); | ||||
5587 | // Mark this as handled. | ||||
5588 | SeenChainsForSExt[HeadOfChain] = nullptr; | ||||
5589 | ValToSExtendedUses[HeadOfChain].push_back(I); | ||||
5590 | } | ||||
5591 | } | ||||
5592 | return Promoted; | ||||
5593 | } | ||||
5594 | |||||
5595 | bool CodeGenPrepare::optimizeExtUses(Instruction *I) { | ||||
5596 | BasicBlock *DefBB = I->getParent(); | ||||
5597 | |||||
5598 | // If the result of a {s|z}ext and its source are both live out, rewrite all | ||||
5599 | // other uses of the source with result of extension. | ||||
5600 | Value *Src = I->getOperand(0); | ||||
5601 | if (Src->hasOneUse()) | ||||
5602 | return false; | ||||
5603 | |||||
5604 | // Only do this xform if truncating is free. | ||||
5605 | if (TLI && !TLI->isTruncateFree(I->getType(), Src->getType())) | ||||
5606 | return false; | ||||
5607 | |||||
5608 | // Only safe to perform the optimization if the source is also defined in | ||||
5609 | // this block. | ||||
5610 | if (!isa<Instruction>(Src) || DefBB != cast<Instruction>(Src)->getParent()) | ||||
5611 | return false; | ||||
5612 | |||||
5613 | bool DefIsLiveOut = false; | ||||
5614 | for (User *U : I->users()) { | ||||
5615 | Instruction *UI = cast<Instruction>(U); | ||||
5616 | |||||
5617 | // Figure out which BB this ext is used in. | ||||
5618 | BasicBlock *UserBB = UI->getParent(); | ||||
5619 | if (UserBB == DefBB) continue; | ||||
5620 | DefIsLiveOut = true; | ||||
5621 | break; | ||||
5622 | } | ||||
5623 | if (!DefIsLiveOut) | ||||
5624 | return false; | ||||
5625 | |||||
5626 | // Make sure none of the uses are PHI nodes. | ||||
5627 | for (User *U : Src->users()) { | ||||
5628 | Instruction *UI = cast<Instruction>(U); | ||||
5629 | BasicBlock *UserBB = UI->getParent(); | ||||
5630 | if (UserBB == DefBB) continue; | ||||
5631 | // Be conservative. We don't want this xform to end up introducing | ||||
5632 | // reloads just before load / store instructions. | ||||
5633 | if (isa<PHINode>(UI) || isa<LoadInst>(UI) || isa<StoreInst>(UI)) | ||||
5634 | return false; | ||||
5635 | } | ||||
5636 | |||||
5637 | // InsertedTruncs - Only insert one trunc in each block once. | ||||
5638 | DenseMap<BasicBlock*, Instruction*> InsertedTruncs; | ||||
5639 | |||||
5640 | bool MadeChange = false; | ||||
5641 | for (Use &U : Src->uses()) { | ||||
5642 | Instruction *User = cast<Instruction>(U.getUser()); | ||||
5643 | |||||
5644 | // Figure out which BB this ext is used in. | ||||
5645 | BasicBlock *UserBB = User->getParent(); | ||||
5646 | if (UserBB == DefBB) continue; | ||||
5647 | |||||
5648 | // Both src and def are live in this block. Rewrite the use. | ||||
5649 | Instruction *&InsertedTrunc = InsertedTruncs[UserBB]; | ||||
5650 | |||||
5651 | if (!InsertedTrunc) { | ||||
5652 | BasicBlock::iterator InsertPt = UserBB->getFirstInsertionPt(); | ||||
5653 | assert(InsertPt != UserBB->end())((InsertPt != UserBB->end()) ? static_cast<void> (0) : __assert_fail ("InsertPt != UserBB->end()", "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 5653, __PRETTY_FUNCTION__)); | ||||
5654 | InsertedTrunc = new TruncInst(I, Src->getType(), "", &*InsertPt); | ||||
5655 | InsertedInsts.insert(InsertedTrunc); | ||||
5656 | } | ||||
5657 | |||||
5658 | // Replace a use of the {s|z}ext source with a use of the result. | ||||
5659 | U = InsertedTrunc; | ||||
5660 | ++NumExtUses; | ||||
5661 | MadeChange = true; | ||||
5662 | } | ||||
5663 | |||||
5664 | return MadeChange; | ||||
5665 | } | ||||
5666 | |||||
5667 | // Find loads whose uses only use some of the loaded value's bits. Add an "and" | ||||
5668 | // just after the load if the target can fold this into one extload instruction, | ||||
5669 | // with the hope of eliminating some of the other later "and" instructions using | ||||
5670 | // the loaded value. "and"s that are made trivially redundant by the insertion | ||||
5671 | // of the new "and" are removed by this function, while others (e.g. those whose | ||||
5672 | // path from the load goes through a phi) are left for isel to potentially | ||||
5673 | // remove. | ||||
5674 | // | ||||
5675 | // For example: | ||||
5676 | // | ||||
5677 | // b0: | ||||
5678 | // x = load i32 | ||||
5679 | // ... | ||||
5680 | // b1: | ||||
5681 | // y = and x, 0xff | ||||
5682 | // z = use y | ||||
5683 | // | ||||
5684 | // becomes: | ||||
5685 | // | ||||
5686 | // b0: | ||||
5687 | // x = load i32 | ||||
5688 | // x' = and x, 0xff | ||||
5689 | // ... | ||||
5690 | // b1: | ||||
5691 | // z = use x' | ||||
5692 | // | ||||
5693 | // whereas: | ||||
5694 | // | ||||
5695 | // b0: | ||||
5696 | // x1 = load i32 | ||||
5697 | // ... | ||||
5698 | // b1: | ||||
5699 | // x2 = load i32 | ||||
5700 | // ... | ||||
5701 | // b2: | ||||
5702 | // x = phi x1, x2 | ||||
5703 | // y = and x, 0xff | ||||
5704 | // | ||||
5705 | // becomes (after a call to optimizeLoadExt for each load): | ||||
5706 | // | ||||
5707 | // b0: | ||||
5708 | // x1 = load i32 | ||||
5709 | // x1' = and x1, 0xff | ||||
5710 | // ... | ||||
5711 | // b1: | ||||
5712 | // x2 = load i32 | ||||
5713 | // x2' = and x2, 0xff | ||||
5714 | // ... | ||||
5715 | // b2: | ||||
5716 | // x = phi x1', x2' | ||||
5717 | // y = and x, 0xff | ||||
5718 | bool CodeGenPrepare::optimizeLoadExt(LoadInst *Load) { | ||||
5719 | if (!Load->isSimple() || !Load->getType()->isIntOrPtrTy()) | ||||
5720 | return false; | ||||
5721 | |||||
5722 | // Skip loads we've already transformed. | ||||
5723 | if (Load->hasOneUse() && | ||||
5724 | InsertedInsts.count(cast<Instruction>(*Load->user_begin()))) | ||||
5725 | return false; | ||||
5726 | |||||
5727 | // Look at all uses of Load, looking through phis, to determine how many bits | ||||
5728 | // of the loaded value are needed. | ||||
5729 | SmallVector<Instruction *, 8> WorkList; | ||||
5730 | SmallPtrSet<Instruction *, 16> Visited; | ||||
5731 | SmallVector<Instruction *, 8> AndsToMaybeRemove; | ||||
5732 | for (auto *U : Load->users()) | ||||
5733 | WorkList.push_back(cast<Instruction>(U)); | ||||
5734 | |||||
5735 | EVT LoadResultVT = TLI->getValueType(*DL, Load->getType()); | ||||
5736 | unsigned BitWidth = LoadResultVT.getSizeInBits(); | ||||
5737 | APInt DemandBits(BitWidth, 0); | ||||
5738 | APInt WidestAndBits(BitWidth, 0); | ||||
5739 | |||||
5740 | while (!WorkList.empty()) { | ||||
5741 | Instruction *I = WorkList.back(); | ||||
5742 | WorkList.pop_back(); | ||||
5743 | |||||
5744 | // Break use-def graph loops. | ||||
5745 | if (!Visited.insert(I).second) | ||||
5746 | continue; | ||||
5747 | |||||
5748 | // For a PHI node, push all of its users. | ||||
5749 | if (auto *Phi = dyn_cast<PHINode>(I)) { | ||||
5750 | for (auto *U : Phi->users()) | ||||
5751 | WorkList.push_back(cast<Instruction>(U)); | ||||
5752 | continue; | ||||
5753 | } | ||||
5754 | |||||
5755 | switch (I->getOpcode()) { | ||||
5756 | case Instruction::And: { | ||||
5757 | auto *AndC = dyn_cast<ConstantInt>(I->getOperand(1)); | ||||
5758 | if (!AndC) | ||||
5759 | return false; | ||||
5760 | APInt AndBits = AndC->getValue(); | ||||
5761 | DemandBits |= AndBits; | ||||
5762 | // Keep track of the widest and mask we see. | ||||
5763 | if (AndBits.ugt(WidestAndBits)) | ||||
5764 | WidestAndBits = AndBits; | ||||
5765 | if (AndBits == WidestAndBits && I->getOperand(0) == Load) | ||||
5766 | AndsToMaybeRemove.push_back(I); | ||||
5767 | break; | ||||
5768 | } | ||||
5769 | |||||
5770 | case Instruction::Shl: { | ||||
5771 | auto *ShlC = dyn_cast<ConstantInt>(I->getOperand(1)); | ||||
5772 | if (!ShlC) | ||||
5773 | return false; | ||||
5774 | uint64_t ShiftAmt = ShlC->getLimitedValue(BitWidth - 1); | ||||
5775 | DemandBits.setLowBits(BitWidth - ShiftAmt); | ||||
5776 | break; | ||||
5777 | } | ||||
5778 | |||||
5779 | case Instruction::Trunc: { | ||||
5780 | EVT TruncVT = TLI->getValueType(*DL, I->getType()); | ||||
5781 | unsigned TruncBitWidth = TruncVT.getSizeInBits(); | ||||
5782 | DemandBits.setLowBits(TruncBitWidth); | ||||
5783 | break; | ||||
5784 | } | ||||
5785 | |||||
5786 | default: | ||||
5787 | return false; | ||||
5788 | } | ||||
5789 | } | ||||
5790 | |||||
5791 | uint32_t ActiveBits = DemandBits.getActiveBits(); | ||||
5792 | // Avoid hoisting (and (load x) 1) since it is unlikely to be folded by the | ||||
5793 | // target even if isLoadExtLegal says an i1 EXTLOAD is valid. For example, | ||||
5794 | // for the AArch64 target isLoadExtLegal(ZEXTLOAD, i32, i1) returns true, but | ||||
5795 | // (and (load x) 1) is not matched as a single instruction, rather as a LDR | ||||
5796 | // followed by an AND. | ||||
5797 | // TODO: Look into removing this restriction by fixing backends to either | ||||
5798 | // return false for isLoadExtLegal for i1 or have them select this pattern to | ||||
5799 | // a single instruction. | ||||
5800 | // | ||||
5801 | // Also avoid hoisting if we didn't see any ands with the exact DemandBits | ||||
5802 | // mask, since these are the only ands that will be removed by isel. | ||||
5803 | if (ActiveBits <= 1 || !DemandBits.isMask(ActiveBits) || | ||||
5804 | WidestAndBits != DemandBits) | ||||
5805 | return false; | ||||
5806 | |||||
5807 | LLVMContext &Ctx = Load->getType()->getContext(); | ||||
5808 | Type *TruncTy = Type::getIntNTy(Ctx, ActiveBits); | ||||
5809 | EVT TruncVT = TLI->getValueType(*DL, TruncTy); | ||||
5810 | |||||
5811 | // Reject cases that won't be matched as extloads. | ||||
5812 | if (!LoadResultVT.bitsGT(TruncVT) || !TruncVT.isRound() || | ||||
5813 | !TLI->isLoadExtLegal(ISD::ZEXTLOAD, LoadResultVT, TruncVT)) | ||||
5814 | return false; | ||||
5815 | |||||
5816 | IRBuilder<> Builder(Load->getNextNode()); | ||||
5817 | auto *NewAnd = dyn_cast<Instruction>( | ||||
5818 | Builder.CreateAnd(Load, ConstantInt::get(Ctx, DemandBits))); | ||||
5819 | // Mark this instruction as "inserted by CGP", so that other | ||||
5820 | // optimizations don't touch it. | ||||
5821 | InsertedInsts.insert(NewAnd); | ||||
5822 | |||||
5823 | // Replace all uses of load with new and (except for the use of load in the | ||||
5824 | // new and itself). | ||||
5825 | Load->replaceAllUsesWith(NewAnd); | ||||
5826 | NewAnd->setOperand(0, Load); | ||||
5827 | |||||
5828 | // Remove any and instructions that are now redundant. | ||||
5829 | for (auto *And : AndsToMaybeRemove) | ||||
5830 | // Check that the and mask is the same as the one we decided to put on the | ||||
5831 | // new and. | ||||
5832 | if (cast<ConstantInt>(And->getOperand(1))->getValue() == DemandBits) { | ||||
5833 | And->replaceAllUsesWith(NewAnd); | ||||
5834 | if (&*CurInstIterator == And) | ||||
5835 | CurInstIterator = std::next(And->getIterator()); | ||||
5836 | And->eraseFromParent(); | ||||
5837 | ++NumAndUses; | ||||
5838 | } | ||||
5839 | |||||
5840 | ++NumAndsAdded; | ||||
5841 | return true; | ||||
5842 | } | ||||
5843 | |||||
5844 | /// Check if V (an operand of a select instruction) is an expensive instruction | ||||
5845 | /// that is only used once. | ||||
5846 | static bool sinkSelectOperand(const TargetTransformInfo *TTI, Value *V) { | ||||
5847 | auto *I = dyn_cast<Instruction>(V); | ||||
5848 | // If it's safe to speculatively execute, then it should not have side | ||||
5849 | // effects; therefore, it's safe to sink and possibly *not* execute. | ||||
5850 | return I && I->hasOneUse() && isSafeToSpeculativelyExecute(I) && | ||||
5851 | TTI->getUserCost(I) >= TargetTransformInfo::TCC_Expensive; | ||||
5852 | } | ||||
5853 | |||||
5854 | /// Returns true if a SelectInst should be turned into an explicit branch. | ||||
5855 | static bool isFormingBranchFromSelectProfitable(const TargetTransformInfo *TTI, | ||||
5856 | const TargetLowering *TLI, | ||||
5857 | SelectInst *SI) { | ||||
5858 | // If even a predictable select is cheap, then a branch can't be cheaper. | ||||
5859 | if (!TLI->isPredictableSelectExpensive()) | ||||
5860 | return false; | ||||
5861 | |||||
5862 | // FIXME: This should use the same heuristics as IfConversion to determine | ||||
5863 | // whether a select is better represented as a branch. | ||||
5864 | |||||
5865 | // If metadata tells us that the select condition is obviously predictable, | ||||
5866 | // then we want to replace the select with a branch. | ||||
5867 | uint64_t TrueWeight, FalseWeight; | ||||
5868 | if (SI->extractProfMetadata(TrueWeight, FalseWeight)) { | ||||
5869 | uint64_t Max = std::max(TrueWeight, FalseWeight); | ||||
5870 | uint64_t Sum = TrueWeight + FalseWeight; | ||||
5871 | if (Sum != 0) { | ||||
5872 | auto Probability = BranchProbability::getBranchProbability(Max, Sum); | ||||
5873 | if (Probability > TLI->getPredictableBranchThreshold()) | ||||
5874 | return true; | ||||
5875 | } | ||||
5876 | } | ||||
5877 | |||||
5878 | CmpInst *Cmp = dyn_cast<CmpInst>(SI->getCondition()); | ||||
5879 | |||||
5880 | // If a branch is predictable, an out-of-order CPU can avoid blocking on its | ||||
5881 | // comparison condition. If the compare has more than one use, there's | ||||
5882 | // probably another cmov or setcc around, so it's not worth emitting a branch. | ||||
5883 | if (!Cmp || !Cmp->hasOneUse()) | ||||
5884 | return false; | ||||
5885 | |||||
5886 | // If either operand of the select is expensive and only needed on one side | ||||
5887 | // of the select, we should form a branch. | ||||
5888 | if (sinkSelectOperand(TTI, SI->getTrueValue()) || | ||||
5889 | sinkSelectOperand(TTI, SI->getFalseValue())) | ||||
5890 | return true; | ||||
5891 | |||||
5892 | return false; | ||||
5893 | } | ||||
5894 | |||||
5895 | /// If \p isTrue is true, return the true value of \p SI, otherwise return | ||||
5896 | /// false value of \p SI. If the true/false value of \p SI is defined by any | ||||
5897 | /// select instructions in \p Selects, look through the defining select | ||||
5898 | /// instruction until the true/false value is not defined in \p Selects. | ||||
5899 | static Value *getTrueOrFalseValue( | ||||
5900 | SelectInst *SI, bool isTrue, | ||||
5901 | const SmallPtrSet<const Instruction *, 2> &Selects) { | ||||
5902 | Value *V = nullptr; | ||||
5903 | |||||
5904 | for (SelectInst *DefSI = SI; DefSI != nullptr && Selects.count(DefSI); | ||||
5905 | DefSI = dyn_cast<SelectInst>(V)) { | ||||
5906 | assert(DefSI->getCondition() == SI->getCondition() &&((DefSI->getCondition() == SI->getCondition() && "The condition of DefSI does not match with SI") ? static_cast <void> (0) : __assert_fail ("DefSI->getCondition() == SI->getCondition() && \"The condition of DefSI does not match with SI\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 5907, __PRETTY_FUNCTION__)) | ||||
5907 | "The condition of DefSI does not match with SI")((DefSI->getCondition() == SI->getCondition() && "The condition of DefSI does not match with SI") ? static_cast <void> (0) : __assert_fail ("DefSI->getCondition() == SI->getCondition() && \"The condition of DefSI does not match with SI\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 5907, __PRETTY_FUNCTION__)); | ||||
5908 | V = (isTrue ? DefSI->getTrueValue() : DefSI->getFalseValue()); | ||||
5909 | } | ||||
5910 | |||||
5911 | assert(V && "Failed to get select true/false value")((V && "Failed to get select true/false value") ? static_cast <void> (0) : __assert_fail ("V && \"Failed to get select true/false value\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 5911, __PRETTY_FUNCTION__)); | ||||
5912 | return V; | ||||
5913 | } | ||||
5914 | |||||
5915 | bool CodeGenPrepare::optimizeShiftInst(BinaryOperator *Shift) { | ||||
5916 | assert(Shift->isShift() && "Expected a shift")((Shift->isShift() && "Expected a shift") ? static_cast <void> (0) : __assert_fail ("Shift->isShift() && \"Expected a shift\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 5916, __PRETTY_FUNCTION__)); | ||||
5917 | |||||
5918 | // If this is (1) a vector shift, (2) shifts by scalars are cheaper than | ||||
5919 | // general vector shifts, and (3) the shift amount is a select-of-splatted | ||||
5920 | // values, hoist the shifts before the select: | ||||
5921 | // shift Op0, (select Cond, TVal, FVal) --> | ||||
5922 | // select Cond, (shift Op0, TVal), (shift Op0, FVal) | ||||
5923 | // | ||||
5924 | // This is inverting a generic IR transform when we know that the cost of a | ||||
5925 | // general vector shift is more than the cost of 2 shift-by-scalars. | ||||
5926 | // We can't do this effectively in SDAG because we may not be able to | ||||
5927 | // determine if the select operands are splats from within a basic block. | ||||
5928 | Type *Ty = Shift->getType(); | ||||
5929 | if (!Ty->isVectorTy() || !TLI->isVectorShiftByScalarCheap(Ty)) | ||||
5930 | return false; | ||||
5931 | Value *Cond, *TVal, *FVal; | ||||
5932 | if (!match(Shift->getOperand(1), | ||||
5933 | m_OneUse(m_Select(m_Value(Cond), m_Value(TVal), m_Value(FVal))))) | ||||
5934 | return false; | ||||
5935 | if (!isSplatValue(TVal) || !isSplatValue(FVal)) | ||||
5936 | return false; | ||||
5937 | |||||
5938 | IRBuilder<> Builder(Shift); | ||||
5939 | BinaryOperator::BinaryOps Opcode = Shift->getOpcode(); | ||||
5940 | Value *NewTVal = Builder.CreateBinOp(Opcode, Shift->getOperand(0), TVal); | ||||
5941 | Value *NewFVal = Builder.CreateBinOp(Opcode, Shift->getOperand(0), FVal); | ||||
5942 | Value *NewSel = Builder.CreateSelect(Cond, NewTVal, NewFVal); | ||||
5943 | Shift->replaceAllUsesWith(NewSel); | ||||
5944 | Shift->eraseFromParent(); | ||||
5945 | return true; | ||||
5946 | } | ||||
5947 | |||||
5948 | /// If we have a SelectInst that will likely profit from branch prediction, | ||||
5949 | /// turn it into a branch. | ||||
5950 | bool CodeGenPrepare::optimizeSelectInst(SelectInst *SI) { | ||||
5951 | // If branch conversion isn't desirable, exit early. | ||||
5952 | if (DisableSelectToBranch || OptSize || !TLI) | ||||
5953 | return false; | ||||
5954 | |||||
5955 | // Find all consecutive select instructions that share the same condition. | ||||
5956 | SmallVector<SelectInst *, 2> ASI; | ||||
5957 | ASI.push_back(SI); | ||||
5958 | for (BasicBlock::iterator It = ++BasicBlock::iterator(SI); | ||||
5959 | It != SI->getParent()->end(); ++It) { | ||||
5960 | SelectInst *I = dyn_cast<SelectInst>(&*It); | ||||
5961 | if (I && SI->getCondition() == I->getCondition()) { | ||||
5962 | ASI.push_back(I); | ||||
5963 | } else { | ||||
5964 | break; | ||||
5965 | } | ||||
5966 | } | ||||
5967 | |||||
5968 | SelectInst *LastSI = ASI.back(); | ||||
5969 | // Increment the current iterator to skip all the rest of select instructions | ||||
5970 | // because they will be either "not lowered" or "all lowered" to branch. | ||||
5971 | CurInstIterator = std::next(LastSI->getIterator()); | ||||
5972 | |||||
5973 | bool VectorCond = !SI->getCondition()->getType()->isIntegerTy(1); | ||||
5974 | |||||
5975 | // Can we convert the 'select' to CF ? | ||||
5976 | if (VectorCond || SI->getMetadata(LLVMContext::MD_unpredictable)) | ||||
5977 | return false; | ||||
5978 | |||||
5979 | TargetLowering::SelectSupportKind SelectKind; | ||||
5980 | if (VectorCond) | ||||
5981 | SelectKind = TargetLowering::VectorMaskSelect; | ||||
5982 | else if (SI->getType()->isVectorTy()) | ||||
5983 | SelectKind = TargetLowering::ScalarCondVectorVal; | ||||
5984 | else | ||||
5985 | SelectKind = TargetLowering::ScalarValSelect; | ||||
5986 | |||||
5987 | if (TLI->isSelectSupported(SelectKind) && | ||||
5988 | !isFormingBranchFromSelectProfitable(TTI, TLI, SI)) | ||||
5989 | return false; | ||||
5990 | |||||
5991 | // The DominatorTree needs to be rebuilt by any consumers after this | ||||
5992 | // transformation. We simply reset here rather than setting the ModifiedDT | ||||
5993 | // flag to avoid restarting the function walk in runOnFunction for each | ||||
5994 | // select optimized. | ||||
5995 | DT.reset(); | ||||
5996 | |||||
5997 | // Transform a sequence like this: | ||||
5998 | // start: | ||||
5999 | // %cmp = cmp uge i32 %a, %b | ||||
6000 | // %sel = select i1 %cmp, i32 %c, i32 %d | ||||
6001 | // | ||||
6002 | // Into: | ||||
6003 | // start: | ||||
6004 | // %cmp = cmp uge i32 %a, %b | ||||
6005 | // br i1 %cmp, label %select.true, label %select.false | ||||
6006 | // select.true: | ||||
6007 | // br label %select.end | ||||
6008 | // select.false: | ||||
6009 | // br label %select.end | ||||
6010 | // select.end: | ||||
6011 | // %sel = phi i32 [ %c, %select.true ], [ %d, %select.false ] | ||||
6012 | // | ||||
6013 | // In addition, we may sink instructions that produce %c or %d from | ||||
6014 | // the entry block into the destination(s) of the new branch. | ||||
6015 | // If the true or false blocks do not contain a sunken instruction, that | ||||
6016 | // block and its branch may be optimized away. In that case, one side of the | ||||
6017 | // first branch will point directly to select.end, and the corresponding PHI | ||||
6018 | // predecessor block will be the start block. | ||||
6019 | |||||
6020 | // First, we split the block containing the select into 2 blocks. | ||||
6021 | BasicBlock *StartBlock = SI->getParent(); | ||||
6022 | BasicBlock::iterator SplitPt = ++(BasicBlock::iterator(LastSI)); | ||||
6023 | BasicBlock *EndBlock = StartBlock->splitBasicBlock(SplitPt, "select.end"); | ||||
6024 | |||||
6025 | // Delete the unconditional branch that was just created by the split. | ||||
6026 | StartBlock->getTerminator()->eraseFromParent(); | ||||
6027 | |||||
6028 | // These are the new basic blocks for the conditional branch. | ||||
6029 | // At least one will become an actual new basic block. | ||||
6030 | BasicBlock *TrueBlock = nullptr; | ||||
6031 | BasicBlock *FalseBlock = nullptr; | ||||
6032 | BranchInst *TrueBranch = nullptr; | ||||
6033 | BranchInst *FalseBranch = nullptr; | ||||
6034 | |||||
6035 | // Sink expensive instructions into the conditional blocks to avoid executing | ||||
6036 | // them speculatively. | ||||
6037 | for (SelectInst *SI : ASI) { | ||||
6038 | if (sinkSelectOperand(TTI, SI->getTrueValue())) { | ||||
6039 | if (TrueBlock == nullptr) { | ||||
6040 | TrueBlock = BasicBlock::Create(SI->getContext(), "select.true.sink", | ||||
6041 | EndBlock->getParent(), EndBlock); | ||||
6042 | TrueBranch = BranchInst::Create(EndBlock, TrueBlock); | ||||
6043 | TrueBranch->setDebugLoc(SI->getDebugLoc()); | ||||
6044 | } | ||||
6045 | auto *TrueInst = cast<Instruction>(SI->getTrueValue()); | ||||
6046 | TrueInst->moveBefore(TrueBranch); | ||||
6047 | } | ||||
6048 | if (sinkSelectOperand(TTI, SI->getFalseValue())) { | ||||
6049 | if (FalseBlock == nullptr) { | ||||
6050 | FalseBlock = BasicBlock::Create(SI->getContext(), "select.false.sink", | ||||
6051 | EndBlock->getParent(), EndBlock); | ||||
6052 | FalseBranch = BranchInst::Create(EndBlock, FalseBlock); | ||||
6053 | FalseBranch->setDebugLoc(SI->getDebugLoc()); | ||||
6054 | } | ||||
6055 | auto *FalseInst = cast<Instruction>(SI->getFalseValue()); | ||||
6056 | FalseInst->moveBefore(FalseBranch); | ||||
6057 | } | ||||
6058 | } | ||||
6059 | |||||
6060 | // If there was nothing to sink, then arbitrarily choose the 'false' side | ||||
6061 | // for a new input value to the PHI. | ||||
6062 | if (TrueBlock == FalseBlock) { | ||||
6063 | assert(TrueBlock == nullptr &&((TrueBlock == nullptr && "Unexpected basic block transform while optimizing select" ) ? static_cast<void> (0) : __assert_fail ("TrueBlock == nullptr && \"Unexpected basic block transform while optimizing select\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 6064, __PRETTY_FUNCTION__)) | ||||
6064 | "Unexpected basic block transform while optimizing select")((TrueBlock == nullptr && "Unexpected basic block transform while optimizing select" ) ? static_cast<void> (0) : __assert_fail ("TrueBlock == nullptr && \"Unexpected basic block transform while optimizing select\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 6064, __PRETTY_FUNCTION__)); | ||||
6065 | |||||
6066 | FalseBlock = BasicBlock::Create(SI->getContext(), "select.false", | ||||
6067 | EndBlock->getParent(), EndBlock); | ||||
6068 | auto *FalseBranch = BranchInst::Create(EndBlock, FalseBlock); | ||||
6069 | FalseBranch->setDebugLoc(SI->getDebugLoc()); | ||||
6070 | } | ||||
6071 | |||||
6072 | // Insert the real conditional branch based on the original condition. | ||||
6073 | // If we did not create a new block for one of the 'true' or 'false' paths | ||||
6074 | // of the condition, it means that side of the branch goes to the end block | ||||
6075 | // directly and the path originates from the start block from the point of | ||||
6076 | // view of the new PHI. | ||||
6077 | BasicBlock *TT, *FT; | ||||
6078 | if (TrueBlock == nullptr) { | ||||
6079 | TT = EndBlock; | ||||
6080 | FT = FalseBlock; | ||||
6081 | TrueBlock = StartBlock; | ||||
6082 | } else if (FalseBlock == nullptr) { | ||||
6083 | TT = TrueBlock; | ||||
6084 | FT = EndBlock; | ||||
6085 | FalseBlock = StartBlock; | ||||
6086 | } else { | ||||
6087 | TT = TrueBlock; | ||||
6088 | FT = FalseBlock; | ||||
6089 | } | ||||
6090 | IRBuilder<>(SI).CreateCondBr(SI->getCondition(), TT, FT, SI); | ||||
6091 | |||||
6092 | SmallPtrSet<const Instruction *, 2> INS; | ||||
6093 | INS.insert(ASI.begin(), ASI.end()); | ||||
6094 | // Use reverse iterator because later select may use the value of the | ||||
6095 | // earlier select, and we need to propagate value through earlier select | ||||
6096 | // to get the PHI operand. | ||||
6097 | for (auto It = ASI.rbegin(); It != ASI.rend(); ++It) { | ||||
6098 | SelectInst *SI = *It; | ||||
6099 | // The select itself is replaced with a PHI Node. | ||||
6100 | PHINode *PN = PHINode::Create(SI->getType(), 2, "", &EndBlock->front()); | ||||
6101 | PN->takeName(SI); | ||||
6102 | PN->addIncoming(getTrueOrFalseValue(SI, true, INS), TrueBlock); | ||||
6103 | PN->addIncoming(getTrueOrFalseValue(SI, false, INS), FalseBlock); | ||||
6104 | PN->setDebugLoc(SI->getDebugLoc()); | ||||
6105 | |||||
6106 | SI->replaceAllUsesWith(PN); | ||||
6107 | SI->eraseFromParent(); | ||||
6108 | INS.erase(SI); | ||||
6109 | ++NumSelectsExpanded; | ||||
6110 | } | ||||
6111 | |||||
6112 | // Instruct OptimizeBlock to skip to the next block. | ||||
6113 | CurInstIterator = StartBlock->end(); | ||||
6114 | return true; | ||||
6115 | } | ||||
6116 | |||||
6117 | static bool isBroadcastShuffle(ShuffleVectorInst *SVI) { | ||||
6118 | SmallVector<int, 16> Mask(SVI->getShuffleMask()); | ||||
6119 | int SplatElem = -1; | ||||
6120 | for (unsigned i = 0; i < Mask.size(); ++i) { | ||||
6121 | if (SplatElem != -1 && Mask[i] != -1 && Mask[i] != SplatElem) | ||||
6122 | return false; | ||||
6123 | SplatElem = Mask[i]; | ||||
6124 | } | ||||
6125 | |||||
6126 | return true; | ||||
6127 | } | ||||
6128 | |||||
6129 | /// Some targets have expensive vector shifts if the lanes aren't all the same | ||||
6130 | /// (e.g. x86 only introduced "vpsllvd" and friends with AVX2). In these cases | ||||
6131 | /// it's often worth sinking a shufflevector splat down to its use so that | ||||
6132 | /// codegen can spot all lanes are identical. | ||||
6133 | bool CodeGenPrepare::optimizeShuffleVectorInst(ShuffleVectorInst *SVI) { | ||||
6134 | BasicBlock *DefBB = SVI->getParent(); | ||||
6135 | |||||
6136 | // Only do this xform if variable vector shifts are particularly expensive. | ||||
6137 | if (!TLI || !TLI->isVectorShiftByScalarCheap(SVI->getType())) | ||||
6138 | return false; | ||||
6139 | |||||
6140 | // We only expect better codegen by sinking a shuffle if we can recognise a | ||||
6141 | // constant splat. | ||||
6142 | if (!isBroadcastShuffle(SVI)) | ||||
6143 | return false; | ||||
6144 | |||||
6145 | // InsertedShuffles - Only insert a shuffle in each block once. | ||||
6146 | DenseMap<BasicBlock*, Instruction*> InsertedShuffles; | ||||
6147 | |||||
6148 | bool MadeChange = false; | ||||
6149 | for (User *U : SVI->users()) { | ||||
6150 | Instruction *UI = cast<Instruction>(U); | ||||
6151 | |||||
6152 | // Figure out which BB this ext is used in. | ||||
6153 | BasicBlock *UserBB = UI->getParent(); | ||||
6154 | if (UserBB == DefBB) continue; | ||||
6155 | |||||
6156 | // For now only apply this when the splat is used by a shift instruction. | ||||
6157 | if (!UI->isShift()) continue; | ||||
6158 | |||||
6159 | // Everything checks out, sink the shuffle if the user's block doesn't | ||||
6160 | // already have a copy. | ||||
6161 | Instruction *&InsertedShuffle = InsertedShuffles[UserBB]; | ||||
6162 | |||||
6163 | if (!InsertedShuffle) { | ||||
6164 | BasicBlock::iterator InsertPt = UserBB->getFirstInsertionPt(); | ||||
6165 | assert(InsertPt != UserBB->end())((InsertPt != UserBB->end()) ? static_cast<void> (0) : __assert_fail ("InsertPt != UserBB->end()", "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 6165, __PRETTY_FUNCTION__)); | ||||
6166 | InsertedShuffle = | ||||
6167 | new ShuffleVectorInst(SVI->getOperand(0), SVI->getOperand(1), | ||||
6168 | SVI->getOperand(2), "", &*InsertPt); | ||||
6169 | InsertedShuffle->setDebugLoc(SVI->getDebugLoc()); | ||||
6170 | } | ||||
6171 | |||||
6172 | UI->replaceUsesOfWith(SVI, InsertedShuffle); | ||||
6173 | MadeChange = true; | ||||
6174 | } | ||||
6175 | |||||
6176 | // If we removed all uses, nuke the shuffle. | ||||
6177 | if (SVI->use_empty()) { | ||||
6178 | SVI->eraseFromParent(); | ||||
6179 | MadeChange = true; | ||||
6180 | } | ||||
6181 | |||||
6182 | return MadeChange; | ||||
6183 | } | ||||
6184 | |||||
6185 | bool CodeGenPrepare::tryToSinkFreeOperands(Instruction *I) { | ||||
6186 | // If the operands of I can be folded into a target instruction together with | ||||
6187 | // I, duplicate and sink them. | ||||
6188 | SmallVector<Use *, 4> OpsToSink; | ||||
6189 | if (!TLI || !TLI->shouldSinkOperands(I, OpsToSink)) | ||||
6190 | return false; | ||||
6191 | |||||
6192 | // OpsToSink can contain multiple uses in a use chain (e.g. | ||||
6193 | // (%u1 with %u1 = shufflevector), (%u2 with %u2 = zext %u1)). The dominating | ||||
6194 | // uses must come first, so we process the ops in reverse order so as to not | ||||
6195 | // create invalid IR. | ||||
6196 | BasicBlock *TargetBB = I->getParent(); | ||||
6197 | bool Changed = false; | ||||
6198 | SmallVector<Use *, 4> ToReplace; | ||||
6199 | for (Use *U : reverse(OpsToSink)) { | ||||
6200 | auto *UI = cast<Instruction>(U->get()); | ||||
6201 | if (UI->getParent() == TargetBB || isa<PHINode>(UI)) | ||||
6202 | continue; | ||||
6203 | ToReplace.push_back(U); | ||||
6204 | } | ||||
6205 | |||||
6206 | SetVector<Instruction *> MaybeDead; | ||||
6207 | DenseMap<Instruction *, Instruction *> NewInstructions; | ||||
6208 | Instruction *InsertPoint = I; | ||||
6209 | for (Use *U : ToReplace) { | ||||
6210 | auto *UI = cast<Instruction>(U->get()); | ||||
6211 | Instruction *NI = UI->clone(); | ||||
6212 | NewInstructions[UI] = NI; | ||||
6213 | MaybeDead.insert(UI); | ||||
6214 | LLVM_DEBUG(dbgs() << "Sinking " << *UI << " to user " << *I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Sinking " << *UI << " to user " << *I << "\n"; } } while (false ); | ||||
6215 | NI->insertBefore(InsertPoint); | ||||
6216 | InsertPoint = NI; | ||||
6217 | InsertedInsts.insert(NI); | ||||
6218 | |||||
6219 | // Update the use for the new instruction, making sure that we update the | ||||
6220 | // sunk instruction uses, if it is part of a chain that has already been | ||||
6221 | // sunk. | ||||
6222 | Instruction *OldI = cast<Instruction>(U->getUser()); | ||||
6223 | if (NewInstructions.count(OldI)) | ||||
6224 | NewInstructions[OldI]->setOperand(U->getOperandNo(), NI); | ||||
6225 | else | ||||
6226 | U->set(NI); | ||||
6227 | Changed = true; | ||||
6228 | } | ||||
6229 | |||||
6230 | // Remove instructions that are dead after sinking. | ||||
6231 | for (auto *I : MaybeDead) { | ||||
6232 | if (!I->hasNUsesOrMore(1)) { | ||||
6233 | LLVM_DEBUG(dbgs() << "Removing dead instruction: " << *I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Removing dead instruction: " << *I << "\n"; } } while (false); | ||||
6234 | I->eraseFromParent(); | ||||
6235 | } | ||||
6236 | } | ||||
6237 | |||||
6238 | return Changed; | ||||
6239 | } | ||||
6240 | |||||
6241 | bool CodeGenPrepare::optimizeSwitchInst(SwitchInst *SI) { | ||||
6242 | if (!TLI || !DL) | ||||
6243 | return false; | ||||
6244 | |||||
6245 | Value *Cond = SI->getCondition(); | ||||
6246 | Type *OldType = Cond->getType(); | ||||
6247 | LLVMContext &Context = Cond->getContext(); | ||||
6248 | MVT RegType = TLI->getRegisterType(Context, TLI->getValueType(*DL, OldType)); | ||||
6249 | unsigned RegWidth = RegType.getSizeInBits(); | ||||
6250 | |||||
6251 | if (RegWidth <= cast<IntegerType>(OldType)->getBitWidth()) | ||||
6252 | return false; | ||||
6253 | |||||
6254 | // If the register width is greater than the type width, expand the condition | ||||
6255 | // of the switch instruction and each case constant to the width of the | ||||
6256 | // register. By widening the type of the switch condition, subsequent | ||||
6257 | // comparisons (for case comparisons) will not need to be extended to the | ||||
6258 | // preferred register width, so we will potentially eliminate N-1 extends, | ||||
6259 | // where N is the number of cases in the switch. | ||||
6260 | auto *NewType = Type::getIntNTy(Context, RegWidth); | ||||
6261 | |||||
6262 | // Zero-extend the switch condition and case constants unless the switch | ||||
6263 | // condition is a function argument that is already being sign-extended. | ||||
6264 | // In that case, we can avoid an unnecessary mask/extension by sign-extending | ||||
6265 | // everything instead. | ||||
6266 | Instruction::CastOps ExtType = Instruction::ZExt; | ||||
6267 | if (auto *Arg = dyn_cast<Argument>(Cond)) | ||||
6268 | if (Arg->hasSExtAttr()) | ||||
6269 | ExtType = Instruction::SExt; | ||||
6270 | |||||
6271 | auto *ExtInst = CastInst::Create(ExtType, Cond, NewType); | ||||
6272 | ExtInst->insertBefore(SI); | ||||
6273 | ExtInst->setDebugLoc(SI->getDebugLoc()); | ||||
6274 | SI->setCondition(ExtInst); | ||||
6275 | for (auto Case : SI->cases()) { | ||||
6276 | APInt NarrowConst = Case.getCaseValue()->getValue(); | ||||
6277 | APInt WideConst = (ExtType == Instruction::ZExt) ? | ||||
6278 | NarrowConst.zext(RegWidth) : NarrowConst.sext(RegWidth); | ||||
6279 | Case.setValue(ConstantInt::get(Context, WideConst)); | ||||
6280 | } | ||||
6281 | |||||
6282 | return true; | ||||
6283 | } | ||||
6284 | |||||
6285 | |||||
6286 | namespace { | ||||
6287 | |||||
6288 | /// Helper class to promote a scalar operation to a vector one. | ||||
6289 | /// This class is used to move downward extractelement transition. | ||||
6290 | /// E.g., | ||||
6291 | /// a = vector_op <2 x i32> | ||||
6292 | /// b = extractelement <2 x i32> a, i32 0 | ||||
6293 | /// c = scalar_op b | ||||
6294 | /// store c | ||||
6295 | /// | ||||
6296 | /// => | ||||
6297 | /// a = vector_op <2 x i32> | ||||
6298 | /// c = vector_op a (equivalent to scalar_op on the related lane) | ||||
6299 | /// * d = extractelement <2 x i32> c, i32 0 | ||||
6300 | /// * store d | ||||
6301 | /// Assuming both extractelement and store can be combine, we get rid of the | ||||
6302 | /// transition. | ||||
6303 | class VectorPromoteHelper { | ||||
6304 | /// DataLayout associated with the current module. | ||||
6305 | const DataLayout &DL; | ||||
6306 | |||||
6307 | /// Used to perform some checks on the legality of vector operations. | ||||
6308 | const TargetLowering &TLI; | ||||
6309 | |||||
6310 | /// Used to estimated the cost of the promoted chain. | ||||
6311 | const TargetTransformInfo &TTI; | ||||
6312 | |||||
6313 | /// The transition being moved downwards. | ||||
6314 | Instruction *Transition; | ||||
6315 | |||||
6316 | /// The sequence of instructions to be promoted. | ||||
6317 | SmallVector<Instruction *, 4> InstsToBePromoted; | ||||
6318 | |||||
6319 | /// Cost of combining a store and an extract. | ||||
6320 | unsigned StoreExtractCombineCost; | ||||
6321 | |||||
6322 | /// Instruction that will be combined with the transition. | ||||
6323 | Instruction *CombineInst = nullptr; | ||||
6324 | |||||
6325 | /// The instruction that represents the current end of the transition. | ||||
6326 | /// Since we are faking the promotion until we reach the end of the chain | ||||
6327 | /// of computation, we need a way to get the current end of the transition. | ||||
6328 | Instruction *getEndOfTransition() const { | ||||
6329 | if (InstsToBePromoted.empty()) | ||||
6330 | return Transition; | ||||
6331 | return InstsToBePromoted.back(); | ||||
6332 | } | ||||
6333 | |||||
6334 | /// Return the index of the original value in the transition. | ||||
6335 | /// E.g., for "extractelement <2 x i32> c, i32 1" the original value, | ||||
6336 | /// c, is at index 0. | ||||
6337 | unsigned getTransitionOriginalValueIdx() const { | ||||
6338 | assert(isa<ExtractElementInst>(Transition) &&((isa<ExtractElementInst>(Transition) && "Other kind of transitions are not supported yet" ) ? static_cast<void> (0) : __assert_fail ("isa<ExtractElementInst>(Transition) && \"Other kind of transitions are not supported yet\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 6339, __PRETTY_FUNCTION__)) | ||||
6339 | "Other kind of transitions are not supported yet")((isa<ExtractElementInst>(Transition) && "Other kind of transitions are not supported yet" ) ? static_cast<void> (0) : __assert_fail ("isa<ExtractElementInst>(Transition) && \"Other kind of transitions are not supported yet\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 6339, __PRETTY_FUNCTION__)); | ||||
6340 | return 0; | ||||
6341 | } | ||||
6342 | |||||
6343 | /// Return the index of the index in the transition. | ||||
6344 | /// E.g., for "extractelement <2 x i32> c, i32 0" the index | ||||
6345 | /// is at index 1. | ||||
6346 | unsigned getTransitionIdx() const { | ||||
6347 | assert(isa<ExtractElementInst>(Transition) &&((isa<ExtractElementInst>(Transition) && "Other kind of transitions are not supported yet" ) ? static_cast<void> (0) : __assert_fail ("isa<ExtractElementInst>(Transition) && \"Other kind of transitions are not supported yet\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 6348, __PRETTY_FUNCTION__)) | ||||
6348 | "Other kind of transitions are not supported yet")((isa<ExtractElementInst>(Transition) && "Other kind of transitions are not supported yet" ) ? static_cast<void> (0) : __assert_fail ("isa<ExtractElementInst>(Transition) && \"Other kind of transitions are not supported yet\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 6348, __PRETTY_FUNCTION__)); | ||||
6349 | return 1; | ||||
6350 | } | ||||
6351 | |||||
6352 | /// Get the type of the transition. | ||||
6353 | /// This is the type of the original value. | ||||
6354 | /// E.g., for "extractelement <2 x i32> c, i32 1" the type of the | ||||
6355 | /// transition is <2 x i32>. | ||||
6356 | Type *getTransitionType() const { | ||||
6357 | return Transition->getOperand(getTransitionOriginalValueIdx())->getType(); | ||||
6358 | } | ||||
6359 | |||||
6360 | /// Promote \p ToBePromoted by moving \p Def downward through. | ||||
6361 | /// I.e., we have the following sequence: | ||||
6362 | /// Def = Transition <ty1> a to <ty2> | ||||
6363 | /// b = ToBePromoted <ty2> Def, ... | ||||
6364 | /// => | ||||
6365 | /// b = ToBePromoted <ty1> a, ... | ||||
6366 | /// Def = Transition <ty1> ToBePromoted to <ty2> | ||||
6367 | void promoteImpl(Instruction *ToBePromoted); | ||||
6368 | |||||
6369 | /// Check whether or not it is profitable to promote all the | ||||
6370 | /// instructions enqueued to be promoted. | ||||
6371 | bool isProfitableToPromote() { | ||||
6372 | Value *ValIdx = Transition->getOperand(getTransitionOriginalValueIdx()); | ||||
6373 | unsigned Index = isa<ConstantInt>(ValIdx) | ||||
6374 | ? cast<ConstantInt>(ValIdx)->getZExtValue() | ||||
6375 | : -1; | ||||
6376 | Type *PromotedType = getTransitionType(); | ||||
6377 | |||||
6378 | StoreInst *ST = cast<StoreInst>(CombineInst); | ||||
6379 | unsigned AS = ST->getPointerAddressSpace(); | ||||
6380 | unsigned Align = ST->getAlignment(); | ||||
6381 | // Check if this store is supported. | ||||
6382 | if (!TLI.allowsMisalignedMemoryAccesses( | ||||
6383 | TLI.getValueType(DL, ST->getValueOperand()->getType()), AS, | ||||
6384 | Align)) { | ||||
6385 | // If this is not supported, there is no way we can combine | ||||
6386 | // the extract with the store. | ||||
6387 | return false; | ||||
6388 | } | ||||
6389 | |||||
6390 | // The scalar chain of computation has to pay for the transition | ||||
6391 | // scalar to vector. | ||||
6392 | // The vector chain has to account for the combining cost. | ||||
6393 | uint64_t ScalarCost = | ||||
6394 | TTI.getVectorInstrCost(Transition->getOpcode(), PromotedType, Index); | ||||
6395 | uint64_t VectorCost = StoreExtractCombineCost; | ||||
6396 | for (const auto &Inst : InstsToBePromoted) { | ||||
6397 | // Compute the cost. | ||||
6398 | // By construction, all instructions being promoted are arithmetic ones. | ||||
6399 | // Moreover, one argument is a constant that can be viewed as a splat | ||||
6400 | // constant. | ||||
6401 | Value *Arg0 = Inst->getOperand(0); | ||||
6402 | bool IsArg0Constant = isa<UndefValue>(Arg0) || isa<ConstantInt>(Arg0) || | ||||
6403 | isa<ConstantFP>(Arg0); | ||||
6404 | TargetTransformInfo::OperandValueKind Arg0OVK = | ||||
6405 | IsArg0Constant ? TargetTransformInfo::OK_UniformConstantValue | ||||
6406 | : TargetTransformInfo::OK_AnyValue; | ||||
6407 | TargetTransformInfo::OperandValueKind Arg1OVK = | ||||
6408 | !IsArg0Constant ? TargetTransformInfo::OK_UniformConstantValue | ||||
6409 | : TargetTransformInfo::OK_AnyValue; | ||||
6410 | ScalarCost += TTI.getArithmeticInstrCost( | ||||
6411 | Inst->getOpcode(), Inst->getType(), Arg0OVK, Arg1OVK); | ||||
6412 | VectorCost += TTI.getArithmeticInstrCost(Inst->getOpcode(), PromotedType, | ||||
6413 | Arg0OVK, Arg1OVK); | ||||
6414 | } | ||||
6415 | LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Estimated cost of computation to be promoted:\nScalar: " << ScalarCost << "\nVector: " << VectorCost << '\n'; } } while (false) | ||||
6416 | dbgs() << "Estimated cost of computation to be promoted:\nScalar: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Estimated cost of computation to be promoted:\nScalar: " << ScalarCost << "\nVector: " << VectorCost << '\n'; } } while (false) | ||||
6417 | << ScalarCost << "\nVector: " << VectorCost << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Estimated cost of computation to be promoted:\nScalar: " << ScalarCost << "\nVector: " << VectorCost << '\n'; } } while (false); | ||||
6418 | return ScalarCost > VectorCost; | ||||
6419 | } | ||||
6420 | |||||
6421 | /// Generate a constant vector with \p Val with the same | ||||
6422 | /// number of elements as the transition. | ||||
6423 | /// \p UseSplat defines whether or not \p Val should be replicated | ||||
6424 | /// across the whole vector. | ||||
6425 | /// In other words, if UseSplat == true, we generate <Val, Val, ..., Val>, | ||||
6426 | /// otherwise we generate a vector with as many undef as possible: | ||||
6427 | /// <undef, ..., undef, Val, undef, ..., undef> where \p Val is only | ||||
6428 | /// used at the index of the extract. | ||||
6429 | Value *getConstantVector(Constant *Val, bool UseSplat) const { | ||||
6430 | unsigned ExtractIdx = std::numeric_limits<unsigned>::max(); | ||||
6431 | if (!UseSplat) { | ||||
6432 | // If we cannot determine where the constant must be, we have to | ||||
6433 | // use a splat constant. | ||||
6434 | Value *ValExtractIdx = Transition->getOperand(getTransitionIdx()); | ||||
6435 | if (ConstantInt *CstVal = dyn_cast<ConstantInt>(ValExtractIdx)) | ||||
6436 | ExtractIdx = CstVal->getSExtValue(); | ||||
6437 | else | ||||
6438 | UseSplat = true; | ||||
6439 | } | ||||
6440 | |||||
6441 | unsigned End = getTransitionType()->getVectorNumElements(); | ||||
6442 | if (UseSplat) | ||||
6443 | return ConstantVector::getSplat(End, Val); | ||||
6444 | |||||
6445 | SmallVector<Constant *, 4> ConstVec; | ||||
6446 | UndefValue *UndefVal = UndefValue::get(Val->getType()); | ||||
6447 | for (unsigned Idx = 0; Idx != End; ++Idx) { | ||||
6448 | if (Idx == ExtractIdx) | ||||
6449 | ConstVec.push_back(Val); | ||||
6450 | else | ||||
6451 | ConstVec.push_back(UndefVal); | ||||
6452 | } | ||||
6453 | return ConstantVector::get(ConstVec); | ||||
6454 | } | ||||
6455 | |||||
6456 | /// Check if promoting to a vector type an operand at \p OperandIdx | ||||
6457 | /// in \p Use can trigger undefined behavior. | ||||
6458 | static bool canCauseUndefinedBehavior(const Instruction *Use, | ||||
6459 | unsigned OperandIdx) { | ||||
6460 | // This is not safe to introduce undef when the operand is on | ||||
6461 | // the right hand side of a division-like instruction. | ||||
6462 | if (OperandIdx != 1) | ||||
6463 | return false; | ||||
6464 | switch (Use->getOpcode()) { | ||||
6465 | default: | ||||
6466 | return false; | ||||
6467 | case Instruction::SDiv: | ||||
6468 | case Instruction::UDiv: | ||||
6469 | case Instruction::SRem: | ||||
6470 | case Instruction::URem: | ||||
6471 | return true; | ||||
6472 | case Instruction::FDiv: | ||||
6473 | case Instruction::FRem: | ||||
6474 | return !Use->hasNoNaNs(); | ||||
6475 | } | ||||
6476 | llvm_unreachable(nullptr)::llvm::llvm_unreachable_internal(nullptr, "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 6476); | ||||
6477 | } | ||||
6478 | |||||
6479 | public: | ||||
6480 | VectorPromoteHelper(const DataLayout &DL, const TargetLowering &TLI, | ||||
6481 | const TargetTransformInfo &TTI, Instruction *Transition, | ||||
6482 | unsigned CombineCost) | ||||
6483 | : DL(DL), TLI(TLI), TTI(TTI), Transition(Transition), | ||||
6484 | StoreExtractCombineCost(CombineCost) { | ||||
6485 | assert(Transition && "Do not know how to promote null")((Transition && "Do not know how to promote null") ? static_cast <void> (0) : __assert_fail ("Transition && \"Do not know how to promote null\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 6485, __PRETTY_FUNCTION__)); | ||||
6486 | } | ||||
6487 | |||||
6488 | /// Check if we can promote \p ToBePromoted to \p Type. | ||||
6489 | bool canPromote(const Instruction *ToBePromoted) const { | ||||
6490 | // We could support CastInst too. | ||||
6491 | return isa<BinaryOperator>(ToBePromoted); | ||||
6492 | } | ||||
6493 | |||||
6494 | /// Check if it is profitable to promote \p ToBePromoted | ||||
6495 | /// by moving downward the transition through. | ||||
6496 | bool shouldPromote(const Instruction *ToBePromoted) const { | ||||
6497 | // Promote only if all the operands can be statically expanded. | ||||
6498 | // Indeed, we do not want to introduce any new kind of transitions. | ||||
6499 | for (const Use &U : ToBePromoted->operands()) { | ||||
6500 | const Value *Val = U.get(); | ||||
6501 | if (Val == getEndOfTransition()) { | ||||
6502 | // If the use is a division and the transition is on the rhs, | ||||
6503 | // we cannot promote the operation, otherwise we may create a | ||||
6504 | // division by zero. | ||||
6505 | if (canCauseUndefinedBehavior(ToBePromoted, U.getOperandNo())) | ||||
6506 | return false; | ||||
6507 | continue; | ||||
6508 | } | ||||
6509 | if (!isa<ConstantInt>(Val) && !isa<UndefValue>(Val) && | ||||
6510 | !isa<ConstantFP>(Val)) | ||||
6511 | return false; | ||||
6512 | } | ||||
6513 | // Check that the resulting operation is legal. | ||||
6514 | int ISDOpcode = TLI.InstructionOpcodeToISD(ToBePromoted->getOpcode()); | ||||
6515 | if (!ISDOpcode) | ||||
6516 | return false; | ||||
6517 | return StressStoreExtract || | ||||
6518 | TLI.isOperationLegalOrCustom( | ||||
6519 | ISDOpcode, TLI.getValueType(DL, getTransitionType(), true)); | ||||
6520 | } | ||||
6521 | |||||
6522 | /// Check whether or not \p Use can be combined | ||||
6523 | /// with the transition. | ||||
6524 | /// I.e., is it possible to do Use(Transition) => AnotherUse? | ||||
6525 | bool canCombine(const Instruction *Use) { return isa<StoreInst>(Use); } | ||||
6526 | |||||
6527 | /// Record \p ToBePromoted as part of the chain to be promoted. | ||||
6528 | void enqueueForPromotion(Instruction *ToBePromoted) { | ||||
6529 | InstsToBePromoted.push_back(ToBePromoted); | ||||
6530 | } | ||||
6531 | |||||
6532 | /// Set the instruction that will be combined with the transition. | ||||
6533 | void recordCombineInstruction(Instruction *ToBeCombined) { | ||||
6534 | assert(canCombine(ToBeCombined) && "Unsupported instruction to combine")((canCombine(ToBeCombined) && "Unsupported instruction to combine" ) ? static_cast<void> (0) : __assert_fail ("canCombine(ToBeCombined) && \"Unsupported instruction to combine\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 6534, __PRETTY_FUNCTION__)); | ||||
6535 | CombineInst = ToBeCombined; | ||||
6536 | } | ||||
6537 | |||||
6538 | /// Promote all the instructions enqueued for promotion if it is | ||||
6539 | /// is profitable. | ||||
6540 | /// \return True if the promotion happened, false otherwise. | ||||
6541 | bool promote() { | ||||
6542 | // Check if there is something to promote. | ||||
6543 | // Right now, if we do not have anything to combine with, | ||||
6544 | // we assume the promotion is not profitable. | ||||
6545 | if (InstsToBePromoted.empty() || !CombineInst) | ||||
6546 | return false; | ||||
6547 | |||||
6548 | // Check cost. | ||||
6549 | if (!StressStoreExtract && !isProfitableToPromote()) | ||||
6550 | return false; | ||||
6551 | |||||
6552 | // Promote. | ||||
6553 | for (auto &ToBePromoted : InstsToBePromoted) | ||||
6554 | promoteImpl(ToBePromoted); | ||||
6555 | InstsToBePromoted.clear(); | ||||
6556 | return true; | ||||
6557 | } | ||||
6558 | }; | ||||
6559 | |||||
6560 | } // end anonymous namespace | ||||
6561 | |||||
6562 | void VectorPromoteHelper::promoteImpl(Instruction *ToBePromoted) { | ||||
6563 | // At this point, we know that all the operands of ToBePromoted but Def | ||||
6564 | // can be statically promoted. | ||||
6565 | // For Def, we need to use its parameter in ToBePromoted: | ||||
6566 | // b = ToBePromoted ty1 a | ||||
6567 | // Def = Transition ty1 b to ty2 | ||||
6568 | // Move the transition down. | ||||
6569 | // 1. Replace all uses of the promoted operation by the transition. | ||||
6570 | // = ... b => = ... Def. | ||||
6571 | assert(ToBePromoted->getType() == Transition->getType() &&((ToBePromoted->getType() == Transition->getType() && "The type of the result of the transition does not match " "the final type" ) ? static_cast<void> (0) : __assert_fail ("ToBePromoted->getType() == Transition->getType() && \"The type of the result of the transition does not match \" \"the final type\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 6573, __PRETTY_FUNCTION__)) | ||||
6572 | "The type of the result of the transition does not match "((ToBePromoted->getType() == Transition->getType() && "The type of the result of the transition does not match " "the final type" ) ? static_cast<void> (0) : __assert_fail ("ToBePromoted->getType() == Transition->getType() && \"The type of the result of the transition does not match \" \"the final type\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 6573, __PRETTY_FUNCTION__)) | ||||
6573 | "the final type")((ToBePromoted->getType() == Transition->getType() && "The type of the result of the transition does not match " "the final type" ) ? static_cast<void> (0) : __assert_fail ("ToBePromoted->getType() == Transition->getType() && \"The type of the result of the transition does not match \" \"the final type\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 6573, __PRETTY_FUNCTION__)); | ||||
6574 | ToBePromoted->replaceAllUsesWith(Transition); | ||||
6575 | // 2. Update the type of the uses. | ||||
6576 | // b = ToBePromoted ty2 Def => b = ToBePromoted ty1 Def. | ||||
6577 | Type *TransitionTy = getTransitionType(); | ||||
6578 | ToBePromoted->mutateType(TransitionTy); | ||||
6579 | // 3. Update all the operands of the promoted operation with promoted | ||||
6580 | // operands. | ||||
6581 | // b = ToBePromoted ty1 Def => b = ToBePromoted ty1 a. | ||||
6582 | for (Use &U : ToBePromoted->operands()) { | ||||
6583 | Value *Val = U.get(); | ||||
6584 | Value *NewVal = nullptr; | ||||
6585 | if (Val == Transition) | ||||
6586 | NewVal = Transition->getOperand(getTransitionOriginalValueIdx()); | ||||
6587 | else if (isa<UndefValue>(Val) || isa<ConstantInt>(Val) || | ||||
6588 | isa<ConstantFP>(Val)) { | ||||
6589 | // Use a splat constant if it is not safe to use undef. | ||||
6590 | NewVal = getConstantVector( | ||||
6591 | cast<Constant>(Val), | ||||
6592 | isa<UndefValue>(Val) || | ||||
6593 | canCauseUndefinedBehavior(ToBePromoted, U.getOperandNo())); | ||||
6594 | } else | ||||
6595 | llvm_unreachable("Did you modified shouldPromote and forgot to update "::llvm::llvm_unreachable_internal("Did you modified shouldPromote and forgot to update " "this?", "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 6596) | ||||
6596 | "this?")::llvm::llvm_unreachable_internal("Did you modified shouldPromote and forgot to update " "this?", "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 6596); | ||||
6597 | ToBePromoted->setOperand(U.getOperandNo(), NewVal); | ||||
6598 | } | ||||
6599 | Transition->moveAfter(ToBePromoted); | ||||
6600 | Transition->setOperand(getTransitionOriginalValueIdx(), ToBePromoted); | ||||
6601 | } | ||||
6602 | |||||
6603 | /// Some targets can do store(extractelement) with one instruction. | ||||
6604 | /// Try to push the extractelement towards the stores when the target | ||||
6605 | /// has this feature and this is profitable. | ||||
6606 | bool CodeGenPrepare::optimizeExtractElementInst(Instruction *Inst) { | ||||
6607 | unsigned CombineCost = std::numeric_limits<unsigned>::max(); | ||||
6608 | if (DisableStoreExtract || !TLI || | ||||
6609 | (!StressStoreExtract && | ||||
6610 | !TLI->canCombineStoreAndExtract(Inst->getOperand(0)->getType(), | ||||
6611 | Inst->getOperand(1), CombineCost))) | ||||
6612 | return false; | ||||
6613 | |||||
6614 | // At this point we know that Inst is a vector to scalar transition. | ||||
6615 | // Try to move it down the def-use chain, until: | ||||
6616 | // - We can combine the transition with its single use | ||||
6617 | // => we got rid of the transition. | ||||
6618 | // - We escape the current basic block | ||||
6619 | // => we would need to check that we are moving it at a cheaper place and | ||||
6620 | // we do not do that for now. | ||||
6621 | BasicBlock *Parent = Inst->getParent(); | ||||
6622 | LLVM_DEBUG(dbgs() << "Found an interesting transition: " << *Inst << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Found an interesting transition: " << *Inst << '\n'; } } while (false); | ||||
6623 | VectorPromoteHelper VPH(*DL, *TLI, *TTI, Inst, CombineCost); | ||||
6624 | // If the transition has more than one use, assume this is not going to be | ||||
6625 | // beneficial. | ||||
6626 | while (Inst->hasOneUse()) { | ||||
6627 | Instruction *ToBePromoted = cast<Instruction>(*Inst->user_begin()); | ||||
6628 | LLVM_DEBUG(dbgs() << "Use: " << *ToBePromoted << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Use: " << *ToBePromoted << '\n'; } } while (false); | ||||
6629 | |||||
6630 | if (ToBePromoted->getParent() != Parent) { | ||||
6631 | LLVM_DEBUG(dbgs() << "Instruction to promote is in a different block ("do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Instruction to promote is in a different block (" << ToBePromoted->getParent()->getName() << ") than the transition (" << Parent->getName() << ").\n"; } } while (false) | ||||
6632 | << ToBePromoted->getParent()->getName()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Instruction to promote is in a different block (" << ToBePromoted->getParent()->getName() << ") than the transition (" << Parent->getName() << ").\n"; } } while (false) | ||||
6633 | << ") than the transition (" << Parent->getName()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Instruction to promote is in a different block (" << ToBePromoted->getParent()->getName() << ") than the transition (" << Parent->getName() << ").\n"; } } while (false) | ||||
6634 | << ").\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Instruction to promote is in a different block (" << ToBePromoted->getParent()->getName() << ") than the transition (" << Parent->getName() << ").\n"; } } while (false); | ||||
6635 | return false; | ||||
6636 | } | ||||
6637 | |||||
6638 | if (VPH.canCombine(ToBePromoted)) { | ||||
6639 | LLVM_DEBUG(dbgs() << "Assume " << *Inst << '\n'do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Assume " << *Inst << '\n' << "will be combined with: " << *ToBePromoted << '\n'; } } while (false) | ||||
6640 | << "will be combined with: " << *ToBePromoted << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Assume " << *Inst << '\n' << "will be combined with: " << *ToBePromoted << '\n'; } } while (false); | ||||
6641 | VPH.recordCombineInstruction(ToBePromoted); | ||||
6642 | bool Changed = VPH.promote(); | ||||
6643 | NumStoreExtractExposed += Changed; | ||||
6644 | return Changed; | ||||
6645 | } | ||||
6646 | |||||
6647 | LLVM_DEBUG(dbgs() << "Try promoting.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Try promoting.\n"; } } while (false); | ||||
6648 | if (!VPH.canPromote(ToBePromoted) || !VPH.shouldPromote(ToBePromoted)) | ||||
6649 | return false; | ||||
6650 | |||||
6651 | LLVM_DEBUG(dbgs() << "Promoting is possible... Enqueue for promotion!\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Promoting is possible... Enqueue for promotion!\n" ; } } while (false); | ||||
6652 | |||||
6653 | VPH.enqueueForPromotion(ToBePromoted); | ||||
6654 | Inst = ToBePromoted; | ||||
6655 | } | ||||
6656 | return false; | ||||
6657 | } | ||||
6658 | |||||
6659 | /// For the instruction sequence of store below, F and I values | ||||
6660 | /// are bundled together as an i64 value before being stored into memory. | ||||
6661 | /// Sometimes it is more efficient to generate separate stores for F and I, | ||||
6662 | /// which can remove the bitwise instructions or sink them to colder places. | ||||
6663 | /// | ||||
6664 | /// (store (or (zext (bitcast F to i32) to i64), | ||||
6665 | /// (shl (zext I to i64), 32)), addr) --> | ||||
6666 | /// (store F, addr) and (store I, addr+4) | ||||
6667 | /// | ||||
6668 | /// Similarly, splitting for other merged store can also be beneficial, like: | ||||
6669 | /// For pair of {i32, i32}, i64 store --> two i32 stores. | ||||
6670 | /// For pair of {i32, i16}, i64 store --> two i32 stores. | ||||
6671 | /// For pair of {i16, i16}, i32 store --> two i16 stores. | ||||
6672 | /// For pair of {i16, i8}, i32 store --> two i16 stores. | ||||
6673 | /// For pair of {i8, i8}, i16 store --> two i8 stores. | ||||
6674 | /// | ||||
6675 | /// We allow each target to determine specifically which kind of splitting is | ||||
6676 | /// supported. | ||||
6677 | /// | ||||
6678 | /// The store patterns are commonly seen from the simple code snippet below | ||||
6679 | /// if only std::make_pair(...) is sroa transformed before inlined into hoo. | ||||
6680 | /// void goo(const std::pair<int, float> &); | ||||
6681 | /// hoo() { | ||||
6682 | /// ... | ||||
6683 | /// goo(std::make_pair(tmp, ftmp)); | ||||
6684 | /// ... | ||||
6685 | /// } | ||||
6686 | /// | ||||
6687 | /// Although we already have similar splitting in DAG Combine, we duplicate | ||||
6688 | /// it in CodeGenPrepare to catch the case in which pattern is across | ||||
6689 | /// multiple BBs. The logic in DAG Combine is kept to catch case generated | ||||
6690 | /// during code expansion. | ||||
6691 | static bool splitMergedValStore(StoreInst &SI, const DataLayout &DL, | ||||
6692 | const TargetLowering &TLI) { | ||||
6693 | // Handle simple but common cases only. | ||||
6694 | Type *StoreType = SI.getValueOperand()->getType(); | ||||
6695 | if (!DL.typeSizeEqualsStoreSize(StoreType) || | ||||
6696 | DL.getTypeSizeInBits(StoreType) == 0) | ||||
6697 | return false; | ||||
6698 | |||||
6699 | unsigned HalfValBitSize = DL.getTypeSizeInBits(StoreType) / 2; | ||||
6700 | Type *SplitStoreType = Type::getIntNTy(SI.getContext(), HalfValBitSize); | ||||
6701 | if (!DL.typeSizeEqualsStoreSize(SplitStoreType)) | ||||
6702 | return false; | ||||
6703 | |||||
6704 | // Don't split the store if it is volatile. | ||||
6705 | if (SI.isVolatile()) | ||||
6706 | return false; | ||||
6707 | |||||
6708 | // Match the following patterns: | ||||
6709 | // (store (or (zext LValue to i64), | ||||
6710 | // (shl (zext HValue to i64), 32)), HalfValBitSize) | ||||
6711 | // or | ||||
6712 | // (store (or (shl (zext HValue to i64), 32)), HalfValBitSize) | ||||
6713 | // (zext LValue to i64), | ||||
6714 | // Expect both operands of OR and the first operand of SHL have only | ||||
6715 | // one use. | ||||
6716 | Value *LValue, *HValue; | ||||
6717 | if (!match(SI.getValueOperand(), | ||||
6718 | m_c_Or(m_OneUse(m_ZExt(m_Value(LValue))), | ||||
6719 | m_OneUse(m_Shl(m_OneUse(m_ZExt(m_Value(HValue))), | ||||
6720 | m_SpecificInt(HalfValBitSize)))))) | ||||
6721 | return false; | ||||
6722 | |||||
6723 | // Check LValue and HValue are int with size less or equal than 32. | ||||
6724 | if (!LValue->getType()->isIntegerTy() || | ||||
6725 | DL.getTypeSizeInBits(LValue->getType()) > HalfValBitSize || | ||||
6726 | !HValue->getType()->isIntegerTy() || | ||||
6727 | DL.getTypeSizeInBits(HValue->getType()) > HalfValBitSize) | ||||
6728 | return false; | ||||
6729 | |||||
6730 | // If LValue/HValue is a bitcast instruction, use the EVT before bitcast | ||||
6731 | // as the input of target query. | ||||
6732 | auto *LBC = dyn_cast<BitCastInst>(LValue); | ||||
6733 | auto *HBC = dyn_cast<BitCastInst>(HValue); | ||||
6734 | EVT LowTy = LBC ? EVT::getEVT(LBC->getOperand(0)->getType()) | ||||
6735 | : EVT::getEVT(LValue->getType()); | ||||
6736 | EVT HighTy = HBC ? EVT::getEVT(HBC->getOperand(0)->getType()) | ||||
6737 | : EVT::getEVT(HValue->getType()); | ||||
6738 | if (!ForceSplitStore && !TLI.isMultiStoresCheaperThanBitsMerge(LowTy, HighTy)) | ||||
6739 | return false; | ||||
6740 | |||||
6741 | // Start to split store. | ||||
6742 | IRBuilder<> Builder(SI.getContext()); | ||||
6743 | Builder.SetInsertPoint(&SI); | ||||
6744 | |||||
6745 | // If LValue/HValue is a bitcast in another BB, create a new one in current | ||||
6746 | // BB so it may be merged with the splitted stores by dag combiner. | ||||
6747 | if (LBC && LBC->getParent() != SI.getParent()) | ||||
6748 | LValue = Builder.CreateBitCast(LBC->getOperand(0), LBC->getType()); | ||||
6749 | if (HBC && HBC->getParent() != SI.getParent()) | ||||
6750 | HValue = Builder.CreateBitCast(HBC->getOperand(0), HBC->getType()); | ||||
6751 | |||||
6752 | bool IsLE = SI.getModule()->getDataLayout().isLittleEndian(); | ||||
6753 | auto CreateSplitStore = [&](Value *V, bool Upper) { | ||||
6754 | V = Builder.CreateZExtOrBitCast(V, SplitStoreType); | ||||
6755 | Value *Addr = Builder.CreateBitCast( | ||||
6756 | SI.getOperand(1), | ||||
6757 | SplitStoreType->getPointerTo(SI.getPointerAddressSpace())); | ||||
6758 | if ((IsLE && Upper) || (!IsLE && !Upper)) | ||||
6759 | Addr = Builder.CreateGEP( | ||||
6760 | SplitStoreType, Addr, | ||||
6761 | ConstantInt::get(Type::getInt32Ty(SI.getContext()), 1)); | ||||
6762 | Builder.CreateAlignedStore( | ||||
6763 | V, Addr, Upper ? SI.getAlignment() / 2 : SI.getAlignment()); | ||||
6764 | }; | ||||
6765 | |||||
6766 | CreateSplitStore(LValue, false); | ||||
6767 | CreateSplitStore(HValue, true); | ||||
6768 | |||||
6769 | // Delete the old store. | ||||
6770 | SI.eraseFromParent(); | ||||
6771 | return true; | ||||
6772 | } | ||||
6773 | |||||
6774 | // Return true if the GEP has two operands, the first operand is of a sequential | ||||
6775 | // type, and the second operand is a constant. | ||||
6776 | static bool GEPSequentialConstIndexed(GetElementPtrInst *GEP) { | ||||
6777 | gep_type_iterator I = gep_type_begin(*GEP); | ||||
6778 | return GEP->getNumOperands() == 2 && | ||||
6779 | I.isSequential() && | ||||
6780 | isa<ConstantInt>(GEP->getOperand(1)); | ||||
6781 | } | ||||
6782 | |||||
6783 | // Try unmerging GEPs to reduce liveness interference (register pressure) across | ||||
6784 | // IndirectBr edges. Since IndirectBr edges tend to touch on many blocks, | ||||
6785 | // reducing liveness interference across those edges benefits global register | ||||
6786 | // allocation. Currently handles only certain cases. | ||||
6787 | // | ||||
6788 | // For example, unmerge %GEPI and %UGEPI as below. | ||||
6789 | // | ||||
6790 | // ---------- BEFORE ---------- | ||||
6791 | // SrcBlock: | ||||
6792 | // ... | ||||
6793 | // %GEPIOp = ... | ||||
6794 | // ... | ||||
6795 | // %GEPI = gep %GEPIOp, Idx | ||||
6796 | // ... | ||||
6797 | // indirectbr ... [ label %DstB0, label %DstB1, ... label %DstBi ... ] | ||||
6798 | // (* %GEPI is alive on the indirectbr edges due to other uses ahead) | ||||
6799 | // (* %GEPIOp is alive on the indirectbr edges only because of it's used by | ||||
6800 | // %UGEPI) | ||||
6801 | // | ||||
6802 | // DstB0: ... (there may be a gep similar to %UGEPI to be unmerged) | ||||
6803 | // DstB1: ... (there may be a gep similar to %UGEPI to be unmerged) | ||||
6804 | // ... | ||||
6805 | // | ||||
6806 | // DstBi: | ||||
6807 | // ... | ||||
6808 | // %UGEPI = gep %GEPIOp, UIdx | ||||
6809 | // ... | ||||
6810 | // --------------------------- | ||||
6811 | // | ||||
6812 | // ---------- AFTER ---------- | ||||
6813 | // SrcBlock: | ||||
6814 | // ... (same as above) | ||||
6815 | // (* %GEPI is still alive on the indirectbr edges) | ||||
6816 | // (* %GEPIOp is no longer alive on the indirectbr edges as a result of the | ||||
6817 | // unmerging) | ||||
6818 | // ... | ||||
6819 | // | ||||
6820 | // DstBi: | ||||
6821 | // ... | ||||
6822 | // %UGEPI = gep %GEPI, (UIdx-Idx) | ||||
6823 | // ... | ||||
6824 | // --------------------------- | ||||
6825 | // | ||||
6826 | // The register pressure on the IndirectBr edges is reduced because %GEPIOp is | ||||
6827 | // no longer alive on them. | ||||
6828 | // | ||||
6829 | // We try to unmerge GEPs here in CodGenPrepare, as opposed to limiting merging | ||||
6830 | // of GEPs in the first place in InstCombiner::visitGetElementPtrInst() so as | ||||
6831 | // not to disable further simplications and optimizations as a result of GEP | ||||
6832 | // merging. | ||||
6833 | // | ||||
6834 | // Note this unmerging may increase the length of the data flow critical path | ||||
6835 | // (the path from %GEPIOp to %UGEPI would go through %GEPI), which is a tradeoff | ||||
6836 | // between the register pressure and the length of data-flow critical | ||||
6837 | // path. Restricting this to the uncommon IndirectBr case would minimize the | ||||
6838 | // impact of potentially longer critical path, if any, and the impact on compile | ||||
6839 | // time. | ||||
6840 | static bool tryUnmergingGEPsAcrossIndirectBr(GetElementPtrInst *GEPI, | ||||
6841 | const TargetTransformInfo *TTI) { | ||||
6842 | BasicBlock *SrcBlock = GEPI->getParent(); | ||||
6843 | // Check that SrcBlock ends with an IndirectBr. If not, give up. The common | ||||
6844 | // (non-IndirectBr) cases exit early here. | ||||
6845 | if (!isa<IndirectBrInst>(SrcBlock->getTerminator())) | ||||
6846 | return false; | ||||
6847 | // Check that GEPI is a simple gep with a single constant index. | ||||
6848 | if (!GEPSequentialConstIndexed(GEPI)) | ||||
6849 | return false; | ||||
6850 | ConstantInt *GEPIIdx = cast<ConstantInt>(GEPI->getOperand(1)); | ||||
6851 | // Check that GEPI is a cheap one. | ||||
6852 | if (TTI->getIntImmCost(GEPIIdx->getValue(), GEPIIdx->getType()) | ||||
6853 | > TargetTransformInfo::TCC_Basic) | ||||
6854 | return false; | ||||
6855 | Value *GEPIOp = GEPI->getOperand(0); | ||||
6856 | // Check that GEPIOp is an instruction that's also defined in SrcBlock. | ||||
6857 | if (!isa<Instruction>(GEPIOp)) | ||||
6858 | return false; | ||||
6859 | auto *GEPIOpI = cast<Instruction>(GEPIOp); | ||||
6860 | if (GEPIOpI->getParent() != SrcBlock) | ||||
6861 | return false; | ||||
6862 | // Check that GEP is used outside the block, meaning it's alive on the | ||||
6863 | // IndirectBr edge(s). | ||||
6864 | if (find_if(GEPI->users(), [&](User *Usr) { | ||||
6865 | if (auto *I = dyn_cast<Instruction>(Usr)) { | ||||
6866 | if (I->getParent() != SrcBlock) { | ||||
6867 | return true; | ||||
6868 | } | ||||
6869 | } | ||||
6870 | return false; | ||||
6871 | }) == GEPI->users().end()) | ||||
6872 | return false; | ||||
6873 | // The second elements of the GEP chains to be unmerged. | ||||
6874 | std::vector<GetElementPtrInst *> UGEPIs; | ||||
6875 | // Check each user of GEPIOp to check if unmerging would make GEPIOp not alive | ||||
6876 | // on IndirectBr edges. | ||||
6877 | for (User *Usr : GEPIOp->users()) { | ||||
6878 | if (Usr == GEPI) continue; | ||||
6879 | // Check if Usr is an Instruction. If not, give up. | ||||
6880 | if (!isa<Instruction>(Usr)) | ||||
6881 | return false; | ||||
6882 | auto *UI = cast<Instruction>(Usr); | ||||
6883 | // Check if Usr in the same block as GEPIOp, which is fine, skip. | ||||
6884 | if (UI->getParent() == SrcBlock) | ||||
6885 | continue; | ||||
6886 | // Check if Usr is a GEP. If not, give up. | ||||
6887 | if (!isa<GetElementPtrInst>(Usr)) | ||||
6888 | return false; | ||||
6889 | auto *UGEPI = cast<GetElementPtrInst>(Usr); | ||||
6890 | // Check if UGEPI is a simple gep with a single constant index and GEPIOp is | ||||
6891 | // the pointer operand to it. If so, record it in the vector. If not, give | ||||
6892 | // up. | ||||
6893 | if (!GEPSequentialConstIndexed(UGEPI)) | ||||
6894 | return false; | ||||
6895 | if (UGEPI->getOperand(0) != GEPIOp) | ||||
6896 | return false; | ||||
6897 | if (GEPIIdx->getType() != | ||||
6898 | cast<ConstantInt>(UGEPI->getOperand(1))->getType()) | ||||
6899 | return false; | ||||
6900 | ConstantInt *UGEPIIdx = cast<ConstantInt>(UGEPI->getOperand(1)); | ||||
6901 | if (TTI->getIntImmCost(UGEPIIdx->getValue(), UGEPIIdx->getType()) | ||||
6902 | > TargetTransformInfo::TCC_Basic) | ||||
6903 | return false; | ||||
6904 | UGEPIs.push_back(UGEPI); | ||||
6905 | } | ||||
6906 | if (UGEPIs.size() == 0) | ||||
6907 | return false; | ||||
6908 | // Check the materializing cost of (Uidx-Idx). | ||||
6909 | for (GetElementPtrInst *UGEPI : UGEPIs) { | ||||
6910 | ConstantInt *UGEPIIdx = cast<ConstantInt>(UGEPI->getOperand(1)); | ||||
6911 | APInt NewIdx = UGEPIIdx->getValue() - GEPIIdx->getValue(); | ||||
6912 | unsigned ImmCost = TTI->getIntImmCost(NewIdx, GEPIIdx->getType()); | ||||
6913 | if (ImmCost > TargetTransformInfo::TCC_Basic) | ||||
6914 | return false; | ||||
6915 | } | ||||
6916 | // Now unmerge between GEPI and UGEPIs. | ||||
6917 | for (GetElementPtrInst *UGEPI : UGEPIs) { | ||||
6918 | UGEPI->setOperand(0, GEPI); | ||||
6919 | ConstantInt *UGEPIIdx = cast<ConstantInt>(UGEPI->getOperand(1)); | ||||
6920 | Constant *NewUGEPIIdx = | ||||
6921 | ConstantInt::get(GEPIIdx->getType(), | ||||
6922 | UGEPIIdx->getValue() - GEPIIdx->getValue()); | ||||
6923 | UGEPI->setOperand(1, NewUGEPIIdx); | ||||
6924 | // If GEPI is not inbounds but UGEPI is inbounds, change UGEPI to not | ||||
6925 | // inbounds to avoid UB. | ||||
6926 | if (!GEPI->isInBounds()) { | ||||
6927 | UGEPI->setIsInBounds(false); | ||||
6928 | } | ||||
6929 | } | ||||
6930 | // After unmerging, verify that GEPIOp is actually only used in SrcBlock (not | ||||
6931 | // alive on IndirectBr edges). | ||||
6932 | assert(find_if(GEPIOp->users(), [&](User *Usr) {((find_if(GEPIOp->users(), [&](User *Usr) { return cast <Instruction>(Usr)->getParent() != SrcBlock; }) == GEPIOp ->users().end() && "GEPIOp is used outside SrcBlock" ) ? static_cast<void> (0) : __assert_fail ("find_if(GEPIOp->users(), [&](User *Usr) { return cast<Instruction>(Usr)->getParent() != SrcBlock; }) == GEPIOp->users().end() && \"GEPIOp is used outside SrcBlock\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 6934, __PRETTY_FUNCTION__)) | ||||
6933 | return cast<Instruction>(Usr)->getParent() != SrcBlock;((find_if(GEPIOp->users(), [&](User *Usr) { return cast <Instruction>(Usr)->getParent() != SrcBlock; }) == GEPIOp ->users().end() && "GEPIOp is used outside SrcBlock" ) ? static_cast<void> (0) : __assert_fail ("find_if(GEPIOp->users(), [&](User *Usr) { return cast<Instruction>(Usr)->getParent() != SrcBlock; }) == GEPIOp->users().end() && \"GEPIOp is used outside SrcBlock\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 6934, __PRETTY_FUNCTION__)) | ||||
6934 | }) == GEPIOp->users().end() && "GEPIOp is used outside SrcBlock")((find_if(GEPIOp->users(), [&](User *Usr) { return cast <Instruction>(Usr)->getParent() != SrcBlock; }) == GEPIOp ->users().end() && "GEPIOp is used outside SrcBlock" ) ? static_cast<void> (0) : __assert_fail ("find_if(GEPIOp->users(), [&](User *Usr) { return cast<Instruction>(Usr)->getParent() != SrcBlock; }) == GEPIOp->users().end() && \"GEPIOp is used outside SrcBlock\"" , "/build/llvm-toolchain-snapshot-10~svn373517/lib/CodeGen/CodeGenPrepare.cpp" , 6934, __PRETTY_FUNCTION__)); | ||||
6935 | return true; | ||||
6936 | } | ||||
6937 | |||||
6938 | bool CodeGenPrepare::optimizeInst(Instruction *I, bool &ModifiedDT) { | ||||
6939 | // Bail out if we inserted the instruction to prevent optimizations from | ||||
6940 | // stepping on each other's toes. | ||||
6941 | if (InsertedInsts.count(I)) | ||||
6942 | return false; | ||||
6943 | |||||
6944 | // TODO: Move into the switch on opcode below here. | ||||
6945 | if (PHINode *P = dyn_cast<PHINode>(I)) { | ||||
6946 | // It is possible for very late stage optimizations (such as SimplifyCFG) | ||||
6947 | // to introduce PHI nodes too late to be cleaned up. If we detect such a | ||||
6948 | // trivial PHI, go ahead and zap it here. | ||||
6949 | if (Value *V = SimplifyInstruction(P, {*DL, TLInfo})) { | ||||
6950 | LargeOffsetGEPMap.erase(P); | ||||
6951 | P->replaceAllUsesWith(V); | ||||
6952 | P->eraseFromParent(); | ||||
6953 | ++NumPHIsElim; | ||||
6954 | return true; | ||||
6955 | } | ||||
6956 | return false; | ||||
6957 | } | ||||
6958 | |||||
6959 | if (CastInst *CI = dyn_cast<CastInst>(I)) { | ||||
6960 | // If the source of the cast is a constant, then this should have | ||||
6961 | // already been constant folded. The only reason NOT to constant fold | ||||
6962 | // it is if something (e.g. LSR) was careful to place the constant | ||||
6963 | // evaluation in a block other than then one that uses it (e.g. to hoist | ||||
6964 | // the address of globals out of a loop). If this is the case, we don't | ||||
6965 | // want to forward-subst the cast. | ||||
6966 | if (isa<Constant>(CI->getOperand(0))) | ||||
6967 | return false; | ||||
6968 | |||||
6969 | if (TLI && OptimizeNoopCopyExpression(CI, *TLI, *DL)) | ||||
6970 | return true; | ||||
6971 | |||||
6972 | if (isa<ZExtInst>(I) || isa<SExtInst>(I)) { | ||||
6973 | /// Sink a zext or sext into its user blocks if the target type doesn't | ||||
6974 | /// fit in one register | ||||
6975 | if (TLI && | ||||
6976 | TLI->getTypeAction(CI->getContext(), | ||||
6977 | TLI->getValueType(*DL, CI->getType())) == | ||||
6978 | TargetLowering::TypeExpandInteger) { | ||||
6979 | return SinkCast(CI); | ||||
6980 | } else { | ||||
6981 | bool MadeChange = optimizeExt(I); | ||||
6982 | return MadeChange | optimizeExtUses(I); | ||||
6983 | } | ||||
6984 | } | ||||
6985 | return false; | ||||
6986 | } | ||||
6987 | |||||
6988 | if (auto *Cmp = dyn_cast<CmpInst>(I)) | ||||
6989 | if (TLI && optimizeCmp(Cmp, ModifiedDT)) | ||||
6990 | return true; | ||||
6991 | |||||
6992 | if (LoadInst *LI = dyn_cast<LoadInst>(I)) { | ||||
6993 | LI->setMetadata(LLVMContext::MD_invariant_group, nullptr); | ||||
6994 | if (TLI) { | ||||
6995 | bool Modified = optimizeLoadExt(LI); | ||||
6996 | unsigned AS = LI->getPointerAddressSpace(); | ||||
6997 | Modified |= optimizeMemoryInst(I, I->getOperand(0), LI->getType(), AS); | ||||
6998 | return Modified; | ||||
6999 | } | ||||
7000 | return false; | ||||
7001 | } | ||||
7002 | |||||
7003 | if (StoreInst *SI = dyn_cast<StoreInst>(I)) { | ||||
7004 | if (TLI && splitMergedValStore(*SI, *DL, *TLI)) | ||||
7005 | return true; | ||||
7006 | SI->setMetadata(LLVMContext::MD_invariant_group, nullptr); | ||||
7007 | if (TLI) { | ||||
7008 | unsigned AS = SI->getPointerAddressSpace(); | ||||
7009 | return optimizeMemoryInst(I, SI->getOperand(1), | ||||
7010 | SI->getOperand(0)->getType(), AS); | ||||
7011 | } | ||||
7012 | return false; | ||||
7013 | } | ||||
7014 | |||||
7015 | if (AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(I)) { | ||||
7016 | unsigned AS = RMW->getPointerAddressSpace(); | ||||
7017 | return optimizeMemoryInst(I, RMW->getPointerOperand(), | ||||
7018 | RMW->getType(), AS); | ||||
7019 | } | ||||
7020 | |||||
7021 | if (AtomicCmpXchgInst *CmpX = dyn_cast<AtomicCmpXchgInst>(I)) { | ||||
7022 | unsigned AS = CmpX->getPointerAddressSpace(); | ||||
7023 | return optimizeMemoryInst(I, CmpX->getPointerOperand(), | ||||
7024 | CmpX->getCompareOperand()->getType(), AS); | ||||
7025 | } | ||||
7026 | |||||
7027 | BinaryOperator *BinOp = dyn_cast<BinaryOperator>(I); | ||||
7028 | |||||
7029 | if (BinOp && (BinOp->getOpcode() == Instruction::And) && | ||||
7030 | EnableAndCmpSinking && TLI) | ||||
7031 | return sinkAndCmp0Expression(BinOp, *TLI, InsertedInsts); | ||||
7032 | |||||
7033 | // TODO: Move this into the switch on opcode - it handles shifts already. | ||||
7034 | if (BinOp && (BinOp->getOpcode() == Instruction::AShr || | ||||
7035 | BinOp->getOpcode() == Instruction::LShr)) { | ||||
7036 | ConstantInt *CI = dyn_cast<ConstantInt>(BinOp->getOperand(1)); | ||||
7037 | if (TLI && CI && TLI->hasExtractBitsInsn()) | ||||
7038 | if (OptimizeExtractBits(BinOp, CI, *TLI, *DL)) | ||||
7039 | return true; | ||||
7040 | } | ||||
7041 | |||||
7042 | if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(I)) { | ||||
7043 | if (GEPI->hasAllZeroIndices()) { | ||||
7044 | /// The GEP operand must be a pointer, so must its result -> BitCast | ||||
7045 | Instruction *NC = new BitCastInst(GEPI->getOperand(0), GEPI->getType(), | ||||
7046 | GEPI->getName(), GEPI); | ||||
7047 | NC->setDebugLoc(GEPI->getDebugLoc()); | ||||
7048 | GEPI->replaceAllUsesWith(NC); | ||||
7049 | GEPI->eraseFromParent(); | ||||
7050 | ++NumGEPsElim; | ||||
7051 | optimizeInst(NC, ModifiedDT); | ||||
7052 | return true; | ||||
7053 | } | ||||
7054 | if (tryUnmergingGEPsAcrossIndirectBr(GEPI, TTI)) { | ||||
7055 | return true; | ||||
7056 | } | ||||
7057 | return false; | ||||
7058 | } | ||||
7059 | |||||
7060 | if (tryToSinkFreeOperands(I)) | ||||
7061 | return true; | ||||
7062 | |||||
7063 | switch (I->getOpcode()) { | ||||
7064 | case Instruction::Shl: | ||||
7065 | case Instruction::LShr: | ||||
7066 | case Instruction::AShr: | ||||
7067 | return optimizeShiftInst(cast<BinaryOperator>(I)); | ||||
7068 | case Instruction::Call: | ||||
7069 | return optimizeCallInst(cast<CallInst>(I), ModifiedDT); | ||||
7070 | case Instruction::Select: | ||||
7071 | return optimizeSelectInst(cast<SelectInst>(I)); | ||||
7072 | case Instruction::ShuffleVector: | ||||
7073 | return optimizeShuffleVectorInst(cast<ShuffleVectorInst>(I)); | ||||
7074 | case Instruction::Switch: | ||||
7075 | return optimizeSwitchInst(cast<SwitchInst>(I)); | ||||
7076 | case Instruction::ExtractElement: | ||||
7077 | return optimizeExtractElementInst(cast<ExtractElementInst>(I)); | ||||
7078 | } | ||||
7079 | |||||
7080 | return false; | ||||
7081 | } | ||||
7082 | |||||
7083 | /// Given an OR instruction, check to see if this is a bitreverse | ||||
7084 | /// idiom. If so, insert the new intrinsic and return true. | ||||
7085 | static bool makeBitReverse(Instruction &I, const DataLayout &DL, | ||||
7086 | const TargetLowering &TLI) { | ||||
7087 | if (!I.getType()->isIntegerTy() || | ||||
7088 | !TLI.isOperationLegalOrCustom(ISD::BITREVERSE, | ||||
7089 | TLI.getValueType(DL, I.getType(), true))) | ||||
7090 | return false; | ||||
7091 | |||||
7092 | SmallVector<Instruction*, 4> Insts; | ||||
7093 | if (!recognizeBSwapOrBitReverseIdiom(&I, false, true, Insts)) | ||||
7094 | return false; | ||||
7095 | Instruction *LastInst = Insts.back(); | ||||
7096 | I.replaceAllUsesWith(LastInst); | ||||
7097 | RecursivelyDeleteTriviallyDeadInstructions(&I); | ||||
7098 | return true; | ||||
7099 | } | ||||
7100 | |||||
7101 | // In this pass we look for GEP and cast instructions that are used | ||||
7102 | // across basic blocks and rewrite them to improve basic-block-at-a-time | ||||
7103 | // selection. | ||||
7104 | bool CodeGenPrepare::optimizeBlock(BasicBlock &BB, bool &ModifiedDT) { | ||||
7105 | SunkAddrs.clear(); | ||||
7106 | bool MadeChange = false; | ||||
7107 | |||||
7108 | CurInstIterator = BB.begin(); | ||||
7109 | while (CurInstIterator != BB.end()) { | ||||
7110 | MadeChange |= optimizeInst(&*CurInstIterator++, ModifiedDT); | ||||
7111 | if (ModifiedDT) | ||||
7112 | return true; | ||||
7113 | } | ||||
7114 | |||||
7115 | bool MadeBitReverse = true; | ||||
7116 | while (TLI && MadeBitReverse) { | ||||
7117 | MadeBitReverse = false; | ||||
7118 | for (auto &I : reverse(BB)) { | ||||
7119 | if (makeBitReverse(I, *DL, *TLI)) { | ||||
7120 | MadeBitReverse = MadeChange = true; | ||||
7121 | break; | ||||
7122 | } | ||||
7123 | } | ||||
7124 | } | ||||
7125 | MadeChange |= dupRetToEnableTailCallOpts(&BB, ModifiedDT); | ||||
7126 | |||||
7127 | return MadeChange; | ||||
7128 | } | ||||
7129 | |||||
7130 | // llvm.dbg.value is far away from the value then iSel may not be able | ||||
7131 | // handle it properly. iSel will drop llvm.dbg.value if it can not | ||||
7132 | // find a node corresponding to the value. | ||||
7133 | bool CodeGenPrepare::placeDbgValues(Function &F) { | ||||
7134 | bool MadeChange = false; | ||||
7135 | for (BasicBlock &BB : F) { | ||||
7136 | Instruction *PrevNonDbgInst = nullptr; | ||||
7137 | for (BasicBlock::iterator BI = BB.begin(), BE = BB.end(); BI != BE;) { | ||||
7138 | Instruction *Insn = &*BI++; | ||||
7139 | DbgValueInst *DVI = dyn_cast<DbgValueInst>(Insn); | ||||
7140 | // Leave dbg.values that refer to an alloca alone. These | ||||
7141 | // intrinsics describe the address of a variable (= the alloca) | ||||
7142 | // being taken. They should not be moved next to the alloca | ||||
7143 | // (and to the beginning of the scope), but rather stay close to | ||||
7144 | // where said address is used. | ||||
7145 | if (!DVI || (DVI->getValue() && isa<AllocaInst>(DVI->getValue()))) { | ||||
7146 | PrevNonDbgInst = Insn; | ||||
7147 | continue; | ||||
7148 | } | ||||
7149 | |||||
7150 | Instruction *VI = dyn_cast_or_null<Instruction>(DVI->getValue()); | ||||
7151 | if (VI && VI != PrevNonDbgInst && !VI->isTerminator()) { | ||||
7152 | // If VI is a phi in a block with an EHPad terminator, we can't insert | ||||
7153 | // after it. | ||||
7154 | if (isa<PHINode>(VI) && VI->getParent()->getTerminator()->isEHPad()) | ||||
7155 | continue; | ||||
7156 | LLVM_DEBUG(dbgs() << "Moving Debug Value before :\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Moving Debug Value before :\n" << *DVI << ' ' << *VI; } } while (false) | ||||
7157 | << *DVI << ' ' << *VI)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Moving Debug Value before :\n" << *DVI << ' ' << *VI; } } while (false); | ||||
7158 | DVI->removeFromParent(); | ||||
7159 | if (isa<PHINode>(VI)) | ||||
7160 | DVI->insertBefore(&*VI->getParent()->getFirstInsertionPt()); | ||||
7161 | else | ||||
7162 | DVI->insertAfter(VI); | ||||
7163 | MadeChange = true; | ||||
7164 | ++NumDbgValueMoved; | ||||
7165 | } | ||||
7166 | } | ||||
7167 | } | ||||
7168 | return MadeChange; | ||||
7169 | } | ||||
7170 | |||||
7171 | /// Scale down both weights to fit into uint32_t. | ||||
7172 | static void scaleWeights(uint64_t &NewTrue, uint64_t &NewFalse) { | ||||
7173 | uint64_t NewMax = (NewTrue > NewFalse) ? NewTrue : NewFalse; | ||||
7174 | uint32_t Scale = (NewMax / std::numeric_limits<uint32_t>::max()) + 1; | ||||
7175 | NewTrue = NewTrue / Scale; | ||||
7176 | NewFalse = NewFalse / Scale; | ||||
7177 | } | ||||
7178 | |||||
7179 | /// Some targets prefer to split a conditional branch like: | ||||
7180 | /// \code | ||||
7181 | /// %0 = icmp ne i32 %a, 0 | ||||
7182 | /// %1 = icmp ne i32 %b, 0 | ||||
7183 | /// %or.cond = or i1 %0, %1 | ||||
7184 | /// br i1 %or.cond, label %TrueBB, label %FalseBB | ||||
7185 | /// \endcode | ||||
7186 | /// into multiple branch instructions like: | ||||
7187 | /// \code | ||||
7188 | /// bb1: | ||||
7189 | /// %0 = icmp ne i32 %a, 0 | ||||
7190 | /// br i1 %0, label %TrueBB, label %bb2 | ||||
7191 | /// bb2: | ||||
7192 | /// %1 = icmp ne i32 %b, 0 | ||||
7193 | /// br i1 %1, label %TrueBB, label %FalseBB | ||||
7194 | /// \endcode | ||||
7195 | /// This usually allows instruction selection to do even further optimizations | ||||
7196 | /// and combine the compare with the branch instruction. Currently this is | ||||
7197 | /// applied for targets which have "cheap" jump instructions. | ||||
7198 | /// | ||||
7199 | /// FIXME: Remove the (equivalent?) implementation in SelectionDAG. | ||||
7200 | /// | ||||
7201 | bool CodeGenPrepare::splitBranchCondition(Function &F, bool &ModifiedDT) { | ||||
7202 | if (!TM || !TM->Options.EnableFastISel || !TLI || TLI->isJumpExpensive()) | ||||
7203 | return false; | ||||
7204 | |||||
7205 | bool MadeChange = false; | ||||
7206 | for (auto &BB : F) { | ||||
7207 | // Does this BB end with the following? | ||||
7208 | // %cond1 = icmp|fcmp|binary instruction ... | ||||
7209 | // %cond2 = icmp|fcmp|binary instruction ... | ||||
7210 | // %cond.or = or|and i1 %cond1, cond2 | ||||
7211 | // br i1 %cond.or label %dest1, label %dest2" | ||||
7212 | BinaryOperator *LogicOp; | ||||
7213 | BasicBlock *TBB, *FBB; | ||||
7214 | if (!match(BB.getTerminator(), m_Br(m_OneUse(m_BinOp(LogicOp)), TBB, FBB))) | ||||
7215 | continue; | ||||
7216 | |||||
7217 | auto *Br1 = cast<BranchInst>(BB.getTerminator()); | ||||
7218 | if (Br1->getMetadata(LLVMContext::MD_unpredictable)) | ||||
7219 | continue; | ||||
7220 | |||||
7221 | unsigned Opc; | ||||
7222 | Value *Cond1, *Cond2; | ||||
7223 | if (match(LogicOp, m_And(m_OneUse(m_Value(Cond1)), | ||||
7224 | m_OneUse(m_Value(Cond2))))) | ||||
7225 | Opc = Instruction::And; | ||||
7226 | else if (match(LogicOp, m_Or(m_OneUse(m_Value(Cond1)), | ||||
7227 | m_OneUse(m_Value(Cond2))))) | ||||
7228 | Opc = Instruction::Or; | ||||
7229 | else | ||||
7230 | continue; | ||||
7231 | |||||
7232 | if (!match(Cond1, m_CombineOr(m_Cmp(), m_BinOp())) || | ||||
7233 | !match(Cond2, m_CombineOr(m_Cmp(), m_BinOp())) ) | ||||
7234 | continue; | ||||
7235 | |||||
7236 | LLVM_DEBUG(dbgs() << "Before branch condition splitting\n"; BB.dump())do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "Before branch condition splitting\n" ; BB.dump(); } } while (false); | ||||
7237 | |||||
7238 | // Create a new BB. | ||||
7239 | auto TmpBB = | ||||
7240 | BasicBlock::Create(BB.getContext(), BB.getName() + ".cond.split", | ||||
7241 | BB.getParent(), BB.getNextNode()); | ||||
7242 | |||||
7243 | // Update original basic block by using the first condition directly by the | ||||
7244 | // branch instruction and removing the no longer needed and/or instruction. | ||||
7245 | Br1->setCondition(Cond1); | ||||
7246 | LogicOp->eraseFromParent(); | ||||
7247 | |||||
7248 | // Depending on the condition we have to either replace the true or the | ||||
7249 | // false successor of the original branch instruction. | ||||
7250 | if (Opc == Instruction::And) | ||||
7251 | Br1->setSuccessor(0, TmpBB); | ||||
7252 | else | ||||
7253 | Br1->setSuccessor(1, TmpBB); | ||||
7254 | |||||
7255 | // Fill in the new basic block. | ||||
7256 | auto *Br2 = IRBuilder<>(TmpBB).CreateCondBr(Cond2, TBB, FBB); | ||||
7257 | if (auto *I = dyn_cast<Instruction>(Cond2)) { | ||||
7258 | I->removeFromParent(); | ||||
7259 | I->insertBefore(Br2); | ||||
7260 | } | ||||
7261 | |||||
7262 | // Update PHI nodes in both successors. The original BB needs to be | ||||
7263 | // replaced in one successor's PHI nodes, because the branch comes now from | ||||
7264 | // the newly generated BB (NewBB). In the other successor we need to add one | ||||
7265 | // incoming edge to the PHI nodes, because both branch instructions target | ||||
7266 | // now the same successor. Depending on the original branch condition | ||||
7267 | // (and/or) we have to swap the successors (TrueDest, FalseDest), so that | ||||
7268 | // we perform the correct update for the PHI nodes. | ||||
7269 | // This doesn't change the successor order of the just created branch | ||||
7270 | // instruction (or any other instruction). | ||||
7271 | if (Opc == Instruction::Or) | ||||
7272 | std::swap(TBB, FBB); | ||||
7273 | |||||
7274 | // Replace the old BB with the new BB. | ||||
7275 | TBB->replacePhiUsesWith(&BB, TmpBB); | ||||
7276 | |||||
7277 | // Add another incoming edge form the new BB. | ||||
7278 | for (PHINode &PN : FBB->phis()) { | ||||
7279 | auto *Val = PN.getIncomingValueForBlock(&BB); | ||||
7280 | PN.addIncoming(Val, TmpBB); | ||||
7281 | } | ||||
7282 | |||||
7283 | // Update the branch weights (from SelectionDAGBuilder:: | ||||
7284 | // FindMergedConditions). | ||||
7285 | if (Opc == Instruction::Or) { | ||||
7286 | // Codegen X | Y as: | ||||
7287 | // BB1: | ||||
7288 | // jmp_if_X TBB | ||||
7289 | // jmp TmpBB | ||||
7290 | // TmpBB: | ||||
7291 | // jmp_if_Y TBB | ||||
7292 | // jmp FBB | ||||
7293 | // | ||||
7294 | |||||
7295 | // We have flexibility in setting Prob for BB1 and Prob for NewBB. | ||||
7296 | // The requirement is that | ||||
7297 | // TrueProb for BB1 + (FalseProb for BB1 * TrueProb for TmpBB) | ||||
7298 | // = TrueProb for original BB. | ||||
7299 | // Assuming the original weights are A and B, one choice is to set BB1's | ||||
7300 | // weights to A and A+2B, and set TmpBB's weights to A and 2B. This choice | ||||
7301 | // assumes that | ||||
7302 | // TrueProb for BB1 == FalseProb for BB1 * TrueProb for TmpBB. | ||||
7303 | // Another choice is to assume TrueProb for BB1 equals to TrueProb for | ||||
7304 | // TmpBB, but the math is more complicated. | ||||
7305 | uint64_t TrueWeight, FalseWeight; | ||||
7306 | if (Br1->extractProfMetadata(TrueWeight, FalseWeight)) { | ||||
7307 | uint64_t NewTrueWeight = TrueWeight; | ||||
7308 | uint64_t NewFalseWeight = TrueWeight + 2 * FalseWeight; | ||||
7309 | scaleWeights(NewTrueWeight, NewFalseWeight); | ||||
7310 | Br1->setMetadata(LLVMContext::MD_prof, MDBuilder(Br1->getContext()) | ||||
7311 | .createBranchWeights(TrueWeight, FalseWeight)); | ||||
7312 | |||||
7313 | NewTrueWeight = TrueWeight; | ||||
7314 | NewFalseWeight = 2 * FalseWeight; | ||||
7315 | scaleWeights(NewTrueWeight, NewFalseWeight); | ||||
7316 | Br2->setMetadata(LLVMContext::MD_prof, MDBuilder(Br2->getContext()) | ||||
7317 | .createBranchWeights(TrueWeight, FalseWeight)); | ||||
7318 | } | ||||
7319 | } else { | ||||
7320 | // Codegen X & Y as: | ||||
7321 | // BB1: | ||||
7322 | // jmp_if_X TmpBB | ||||
7323 | // jmp FBB | ||||
7324 | // TmpBB: | ||||
7325 | // jmp_if_Y TBB | ||||
7326 | // jmp FBB | ||||
7327 | // | ||||
7328 | // This requires creation of TmpBB after CurBB. | ||||
7329 | |||||
7330 | // We have flexibility in setting Prob for BB1 and Prob for TmpBB. | ||||
7331 | // The requirement is that | ||||
7332 | // FalseProb for BB1 + (TrueProb for BB1 * FalseProb for TmpBB) | ||||
7333 | // = FalseProb for original BB. | ||||
7334 | // Assuming the original weights are A and B, one choice is to set BB1's | ||||
7335 | // weights to 2A+B and B, and set TmpBB's weights to 2A and B. This choice | ||||
7336 | // assumes that | ||||
7337 | // FalseProb for BB1 == TrueProb for BB1 * FalseProb for TmpBB. | ||||
7338 | uint64_t TrueWeight, FalseWeight; | ||||
7339 | if (Br1->extractProfMetadata(TrueWeight, FalseWeight)) { | ||||
7340 | uint64_t NewTrueWeight = 2 * TrueWeight + FalseWeight; | ||||
7341 | uint64_t NewFalseWeight = FalseWeight; | ||||
7342 | scaleWeights(NewTrueWeight, NewFalseWeight); | ||||
7343 | Br1->setMetadata(LLVMContext::MD_prof, MDBuilder(Br1->getContext()) | ||||
7344 | .createBranchWeights(TrueWeight, FalseWeight)); | ||||
7345 | |||||
7346 | NewTrueWeight = 2 * TrueWeight; | ||||
7347 | NewFalseWeight = FalseWeight; | ||||
7348 | scaleWeights(NewTrueWeight, NewFalseWeight); | ||||
7349 | Br2->setMetadata(LLVMContext::MD_prof, MDBuilder(Br2->getContext()) | ||||
7350 | .createBranchWeights(TrueWeight, FalseWeight)); | ||||
7351 | } | ||||
7352 | } | ||||
7353 | |||||
7354 | ModifiedDT = true; | ||||
7355 | MadeChange = true; | ||||
7356 | |||||
7357 | LLVM_DEBUG(dbgs() << "After branch condition splitting\n"; BB.dump();do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "After branch condition splitting\n" ; BB.dump(); TmpBB->dump(); } } while (false) | ||||
7358 | TmpBB->dump())do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("codegenprepare")) { dbgs() << "After branch condition splitting\n" ; BB.dump(); TmpBB->dump(); } } while (false); | ||||
7359 | } | ||||
7360 | return MadeChange; | ||||
7361 | } |
1 | //===- llvm/ADT/SmallVector.h - 'Normally small' vectors --------*- C++ -*-===// |
2 | // |
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | // See https://llvm.org/LICENSE.txt for license information. |
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | // |
9 | // This file defines the SmallVector class. |
10 | // |
11 | //===----------------------------------------------------------------------===// |
12 | |
13 | #ifndef LLVM_ADT_SMALLVECTOR_H |
14 | #define LLVM_ADT_SMALLVECTOR_H |
15 | |
16 | #include "llvm/ADT/iterator_range.h" |
17 | #include "llvm/Support/AlignOf.h" |
18 | #include "llvm/Support/Compiler.h" |
19 | #include "llvm/Support/MathExtras.h" |
20 | #include "llvm/Support/MemAlloc.h" |
21 | #include "llvm/Support/type_traits.h" |
22 | #include "llvm/Support/ErrorHandling.h" |
23 | #include <algorithm> |
24 | #include <cassert> |
25 | #include <cstddef> |
26 | #include <cstdlib> |
27 | #include <cstring> |
28 | #include <initializer_list> |
29 | #include <iterator> |
30 | #include <memory> |
31 | #include <new> |
32 | #include <type_traits> |
33 | #include <utility> |
34 | |
35 | namespace llvm { |
36 | |
37 | /// This is all the non-templated stuff common to all SmallVectors. |
38 | class SmallVectorBase { |
39 | protected: |
40 | void *BeginX; |
41 | unsigned Size = 0, Capacity; |
42 | |
43 | SmallVectorBase() = delete; |
44 | SmallVectorBase(void *FirstEl, size_t TotalCapacity) |
45 | : BeginX(FirstEl), Capacity(TotalCapacity) {} |
46 | |
47 | /// This is an implementation of the grow() method which only works |
48 | /// on POD-like data types and is out of line to reduce code duplication. |
49 | void grow_pod(void *FirstEl, size_t MinCapacity, size_t TSize); |
50 | |
51 | public: |
52 | size_t size() const { return Size; } |
53 | size_t capacity() const { return Capacity; } |
54 | |
55 | LLVM_NODISCARD[[clang::warn_unused_result]] bool empty() const { return !Size; } |
56 | |
57 | /// Set the array size to \p N, which the current array must have enough |
58 | /// capacity for. |
59 | /// |
60 | /// This does not construct or destroy any elements in the vector. |
61 | /// |
62 | /// Clients can use this in conjunction with capacity() to write past the end |
63 | /// of the buffer when they know that more elements are available, and only |
64 | /// update the size later. This avoids the cost of value initializing elements |
65 | /// which will only be overwritten. |
66 | void set_size(size_t N) { |
67 | assert(N <= capacity())((N <= capacity()) ? static_cast<void> (0) : __assert_fail ("N <= capacity()", "/build/llvm-toolchain-snapshot-10~svn373517/include/llvm/ADT/SmallVector.h" , 67, __PRETTY_FUNCTION__)); |
68 | Size = N; |
69 | } |
70 | }; |
71 | |
72 | /// Figure out the offset of the first element. |
73 | template <class T, typename = void> struct SmallVectorAlignmentAndSize { |
74 | AlignedCharArrayUnion<SmallVectorBase> Base; |
75 | AlignedCharArrayUnion<T> FirstEl; |
76 | }; |
77 | |
78 | /// This is the part of SmallVectorTemplateBase which does not depend on whether |
79 | /// the type T is a POD. The extra dummy template argument is used by ArrayRef |
80 | /// to avoid unnecessarily requiring T to be complete. |
81 | template <typename T, typename = void> |
82 | class SmallVectorTemplateCommon : public SmallVectorBase { |
83 | /// Find the address of the first element. For this pointer math to be valid |
84 | /// with small-size of 0 for T with lots of alignment, it's important that |
85 | /// SmallVectorStorage is properly-aligned even for small-size of 0. |
86 | void *getFirstEl() const { |
87 | return const_cast<void *>(reinterpret_cast<const void *>( |
88 | reinterpret_cast<const char *>(this) + |
89 | offsetof(SmallVectorAlignmentAndSize<T>, FirstEl)__builtin_offsetof(SmallVectorAlignmentAndSize<T>, FirstEl ))); |
90 | } |
91 | // Space after 'FirstEl' is clobbered, do not add any instance vars after it. |
92 | |
93 | protected: |
94 | SmallVectorTemplateCommon(size_t Size) |
95 | : SmallVectorBase(getFirstEl(), Size) {} |
96 | |
97 | void grow_pod(size_t MinCapacity, size_t TSize) { |
98 | SmallVectorBase::grow_pod(getFirstEl(), MinCapacity, TSize); |
99 | } |
100 | |
101 | /// Return true if this is a smallvector which has not had dynamic |
102 | /// memory allocated for it. |
103 | bool isSmall() const { return BeginX == getFirstEl(); } |
104 | |
105 | /// Put this vector in a state of being small. |
106 | void resetToSmall() { |
107 | BeginX = getFirstEl(); |
108 | Size = Capacity = 0; // FIXME: Setting Capacity to 0 is suspect. |
109 | } |
110 | |
111 | public: |
112 | using size_type = size_t; |
113 | using difference_type = ptrdiff_t; |
114 | using value_type = T; |
115 | using iterator = T *; |
116 | using const_iterator = const T *; |
117 | |
118 | using const_reverse_iterator = std::reverse_iterator<const_iterator>; |
119 | using reverse_iterator = std::reverse_iterator<iterator>; |
120 | |
121 | using reference = T &; |
122 | using const_reference = const T &; |
123 | using pointer = T *; |
124 | using const_pointer = const T *; |
125 | |
126 | // forward iterator creation methods. |
127 | iterator begin() { return (iterator)this->BeginX; } |
128 | const_iterator begin() const { return (const_iterator)this->BeginX; } |
129 | iterator end() { return begin() + size(); } |
130 | const_iterator end() const { return begin() + size(); } |
131 | |
132 | // reverse iterator creation methods. |
133 | reverse_iterator rbegin() { return reverse_iterator(end()); } |
134 | const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); } |
135 | reverse_iterator rend() { return reverse_iterator(begin()); } |
136 | const_reverse_iterator rend() const { return const_reverse_iterator(begin());} |
137 | |
138 | size_type size_in_bytes() const { return size() * sizeof(T); } |
139 | size_type max_size() const { return size_type(-1) / sizeof(T); } |
140 | |
141 | size_t capacity_in_bytes() const { return capacity() * sizeof(T); } |
142 | |
143 | /// Return a pointer to the vector's buffer, even if empty(). |
144 | pointer data() { return pointer(begin()); } |
145 | /// Return a pointer to the vector's buffer, even if empty(). |
146 | const_pointer data() const { return const_pointer(begin()); } |
147 | |
148 | reference operator[](size_type idx) { |
149 | assert(idx < size())((idx < size()) ? static_cast<void> (0) : __assert_fail ("idx < size()", "/build/llvm-toolchain-snapshot-10~svn373517/include/llvm/ADT/SmallVector.h" , 149, __PRETTY_FUNCTION__)); |
150 | return begin()[idx]; |
151 | } |
152 | const_reference operator[](size_type idx) const { |
153 | assert(idx < size())((idx < size()) ? static_cast<void> (0) : __assert_fail ("idx < size()", "/build/llvm-toolchain-snapshot-10~svn373517/include/llvm/ADT/SmallVector.h" , 153, __PRETTY_FUNCTION__)); |
154 | return begin()[idx]; |
155 | } |
156 | |
157 | reference front() { |
158 | assert(!empty())((!empty()) ? static_cast<void> (0) : __assert_fail ("!empty()" , "/build/llvm-toolchain-snapshot-10~svn373517/include/llvm/ADT/SmallVector.h" , 158, __PRETTY_FUNCTION__)); |
159 | return begin()[0]; |
160 | } |
161 | const_reference front() const { |
162 | assert(!empty())((!empty()) ? static_cast<void> (0) : __assert_fail ("!empty()" , "/build/llvm-toolchain-snapshot-10~svn373517/include/llvm/ADT/SmallVector.h" , 162, __PRETTY_FUNCTION__)); |
163 | return begin()[0]; |
164 | } |
165 | |
166 | reference back() { |
167 | assert(!empty())((!empty()) ? static_cast<void> (0) : __assert_fail ("!empty()" , "/build/llvm-toolchain-snapshot-10~svn373517/include/llvm/ADT/SmallVector.h" , 167, __PRETTY_FUNCTION__)); |
168 | return end()[-1]; |
169 | } |
170 | const_reference back() const { |
171 | assert(!empty())((!empty()) ? static_cast<void> (0) : __assert_fail ("!empty()" , "/build/llvm-toolchain-snapshot-10~svn373517/include/llvm/ADT/SmallVector.h" , 171, __PRETTY_FUNCTION__)); |
172 | return end()[-1]; |
173 | } |
174 | }; |
175 | |
176 | /// SmallVectorTemplateBase<TriviallyCopyable = false> - This is where we put method |
177 | /// implementations that are designed to work with non-POD-like T's. |
178 | template <typename T, bool = is_trivially_copyable<T>::value> |
179 | class SmallVectorTemplateBase : public SmallVectorTemplateCommon<T> { |
180 | protected: |
181 | SmallVectorTemplateBase(size_t Size) : SmallVectorTemplateCommon<T>(Size) {} |
182 | |
183 | static void destroy_range(T *S, T *E) { |
184 | while (S != E) { |
185 | --E; |
186 | E->~T(); |
187 | } |
188 | } |
189 | |
190 | /// Move the range [I, E) into the uninitialized memory starting with "Dest", |
191 | /// constructing elements as needed. |
192 | template<typename It1, typename It2> |
193 | static void uninitialized_move(It1 I, It1 E, It2 Dest) { |
194 | std::uninitialized_copy(std::make_move_iterator(I), |
195 | std::make_move_iterator(E), Dest); |
196 | } |
197 | |
198 | /// Copy the range [I, E) onto the uninitialized memory starting with "Dest", |
199 | /// constructing elements as needed. |
200 | template<typename It1, typename It2> |
201 | static void uninitialized_copy(It1 I, It1 E, It2 Dest) { |
202 | std::uninitialized_copy(I, E, Dest); |
203 | } |
204 | |
205 | /// Grow the allocated memory (without initializing new elements), doubling |
206 | /// the size of the allocated memory. Guarantees space for at least one more |
207 | /// element, or MinSize more elements if specified. |
208 | void grow(size_t MinSize = 0); |
209 | |
210 | public: |
211 | void push_back(const T &Elt) { |
212 | if (LLVM_UNLIKELY(this->size() >= this->capacity())__builtin_expect((bool)(this->size() >= this->capacity ()), false)) |
213 | this->grow(); |
214 | ::new ((void*) this->end()) T(Elt); |
215 | this->set_size(this->size() + 1); |
216 | } |
217 | |
218 | void push_back(T &&Elt) { |
219 | if (LLVM_UNLIKELY(this->size() >= this->capacity())__builtin_expect((bool)(this->size() >= this->capacity ()), false)) |
220 | this->grow(); |
221 | ::new ((void*) this->end()) T(::std::move(Elt)); |
222 | this->set_size(this->size() + 1); |
223 | } |
224 | |
225 | void pop_back() { |
226 | this->set_size(this->size() - 1); |
227 | this->end()->~T(); |
228 | } |
229 | }; |
230 | |
231 | // Define this out-of-line to dissuade the C++ compiler from inlining it. |
232 | template <typename T, bool TriviallyCopyable> |
233 | void SmallVectorTemplateBase<T, TriviallyCopyable>::grow(size_t MinSize) { |
234 | if (MinSize > UINT32_MAX(4294967295U)) |
235 | report_bad_alloc_error("SmallVector capacity overflow during allocation"); |
236 | |
237 | // Always grow, even from zero. |
238 | size_t NewCapacity = size_t(NextPowerOf2(this->capacity() + 2)); |
239 | NewCapacity = std::min(std::max(NewCapacity, MinSize), size_t(UINT32_MAX(4294967295U))); |
240 | T *NewElts = static_cast<T*>(llvm::safe_malloc(NewCapacity*sizeof(T))); |
241 | |
242 | // Move the elements over. |
243 | this->uninitialized_move(this->begin(), this->end(), NewElts); |
244 | |
245 | // Destroy the original elements. |
246 | destroy_range(this->begin(), this->end()); |
247 | |
248 | // If this wasn't grown from the inline copy, deallocate the old space. |
249 | if (!this->isSmall()) |
250 | free(this->begin()); |
251 | |
252 | this->BeginX = NewElts; |
253 | this->Capacity = NewCapacity; |
254 | } |
255 | |
256 | /// SmallVectorTemplateBase<TriviallyCopyable = true> - This is where we put |
257 | /// method implementations that are designed to work with POD-like T's. |
258 | template <typename T> |
259 | class SmallVectorTemplateBase<T, true> : public SmallVectorTemplateCommon<T> { |
260 | protected: |
261 | SmallVectorTemplateBase(size_t Size) : SmallVectorTemplateCommon<T>(Size) {} |
262 | |
263 | // No need to do a destroy loop for POD's. |
264 | static void destroy_range(T *, T *) {} |
265 | |
266 | /// Move the range [I, E) onto the uninitialized memory |
267 | /// starting with "Dest", constructing elements into it as needed. |
268 | template<typename It1, typename It2> |
269 | static void uninitialized_move(It1 I, It1 E, It2 Dest) { |
270 | // Just do a copy. |
271 | uninitialized_copy(I, E, Dest); |
272 | } |
273 | |
274 | /// Copy the range [I, E) onto the uninitialized memory |
275 | /// starting with "Dest", constructing elements into it as needed. |
276 | template<typename It1, typename It2> |
277 | static void uninitialized_copy(It1 I, It1 E, It2 Dest) { |
278 | // Arbitrary iterator types; just use the basic implementation. |
279 | std::uninitialized_copy(I, E, Dest); |
280 | } |
281 | |
282 | /// Copy the range [I, E) onto the uninitialized memory |
283 | /// starting with "Dest", constructing elements into it as needed. |
284 | template <typename T1, typename T2> |
285 | static void uninitialized_copy( |
286 | T1 *I, T1 *E, T2 *Dest, |
287 | typename std::enable_if<std::is_same<typename std::remove_const<T1>::type, |
288 | T2>::value>::type * = nullptr) { |
289 | // Use memcpy for PODs iterated by pointers (which includes SmallVector |
290 | // iterators): std::uninitialized_copy optimizes to memmove, but we can |
291 | // use memcpy here. Note that I and E are iterators and thus might be |
292 | // invalid for memcpy if they are equal. |
293 | if (I != E) |
294 | memcpy(reinterpret_cast<void *>(Dest), I, (E - I) * sizeof(T)); |
295 | } |
296 | |
297 | /// Double the size of the allocated memory, guaranteeing space for at |
298 | /// least one more element or MinSize if specified. |
299 | void grow(size_t MinSize = 0) { this->grow_pod(MinSize, sizeof(T)); } |
300 | |
301 | public: |
302 | void push_back(const T &Elt) { |
303 | if (LLVM_UNLIKELY(this->size() >= this->capacity())__builtin_expect((bool)(this->size() >= this->capacity ()), false)) |
304 | this->grow(); |
305 | memcpy(reinterpret_cast<void *>(this->end()), &Elt, sizeof(T)); |
306 | this->set_size(this->size() + 1); |
307 | } |
308 | |
309 | void pop_back() { this->set_size(this->size() - 1); } |
310 | }; |
311 | |
312 | /// This class consists of common code factored out of the SmallVector class to |
313 | /// reduce code duplication based on the SmallVector 'N' template parameter. |
314 | template <typename T> |
315 | class SmallVectorImpl : public SmallVectorTemplateBase<T> { |
316 | using SuperClass = SmallVectorTemplateBase<T>; |
317 | |
318 | public: |
319 | using iterator = typename SuperClass::iterator; |
320 | using const_iterator = typename SuperClass::const_iterator; |
321 | using reference = typename SuperClass::reference; |
322 | using size_type = typename SuperClass::size_type; |
323 | |
324 | protected: |
325 | // Default ctor - Initialize to empty. |
326 | explicit SmallVectorImpl(unsigned N) |
327 | : SmallVectorTemplateBase<T>(N) {} |
328 | |
329 | public: |
330 | SmallVectorImpl(const SmallVectorImpl &) = delete; |
331 | |
332 | ~SmallVectorImpl() { |
333 | // Subclass has already destructed this vector's elements. |
334 | // If this wasn't grown from the inline copy, deallocate the old space. |
335 | if (!this->isSmall()) |
336 | free(this->begin()); |
337 | } |
338 | |
339 | void clear() { |
340 | this->destroy_range(this->begin(), this->end()); |
341 | this->Size = 0; |
342 | } |
343 | |
344 | void resize(size_type N) { |
345 | if (N < this->size()) { |
346 | this->destroy_range(this->begin()+N, this->end()); |
347 | this->set_size(N); |
348 | } else if (N > this->size()) { |
349 | if (this->capacity() < N) |
350 | this->grow(N); |
351 | for (auto I = this->end(), E = this->begin() + N; I != E; ++I) |
352 | new (&*I) T(); |
353 | this->set_size(N); |
354 | } |
355 | } |
356 | |
357 | void resize(size_type N, const T &NV) { |
358 | if (N < this->size()) { |
359 | this->destroy_range(this->begin()+N, this->end()); |
360 | this->set_size(N); |
361 | } else if (N > this->size()) { |
362 | if (this->capacity() < N) |
363 | this->grow(N); |
364 | std::uninitialized_fill(this->end(), this->begin()+N, NV); |
365 | this->set_size(N); |
366 | } |
367 | } |
368 | |
369 | void reserve(size_type N) { |
370 | if (this->capacity() < N) |
371 | this->grow(N); |
372 | } |
373 | |
374 | LLVM_NODISCARD[[clang::warn_unused_result]] T pop_back_val() { |
375 | T Result = ::std::move(this->back()); |
376 | this->pop_back(); |
377 | return Result; |
378 | } |
379 | |
380 | void swap(SmallVectorImpl &RHS); |
381 | |
382 | /// Add the specified range to the end of the SmallVector. |
383 | template <typename in_iter, |
384 | typename = typename std::enable_if<std::is_convertible< |
385 | typename std::iterator_traits<in_iter>::iterator_category, |
386 | std::input_iterator_tag>::value>::type> |
387 | void append(in_iter in_start, in_iter in_end) { |
388 | size_type NumInputs = std::distance(in_start, in_end); |
389 | if (NumInputs > this->capacity() - this->size()) |
390 | this->grow(this->size()+NumInputs); |
391 | |
392 | this->uninitialized_copy(in_start, in_end, this->end()); |
393 | this->set_size(this->size() + NumInputs); |
394 | } |
395 | |
396 | /// Append \p NumInputs copies of \p Elt to the end. |
397 | void append(size_type NumInputs, const T &Elt) { |
398 | if (NumInputs > this->capacity() - this->size()) |
399 | this->grow(this->size()+NumInputs); |
400 | |
401 | std::uninitialized_fill_n(this->end(), NumInputs, Elt); |
402 | this->set_size(this->size() + NumInputs); |
403 | } |
404 | |
405 | void append(std::initializer_list<T> IL) { |
406 | append(IL.begin(), IL.end()); |
407 | } |
408 | |
409 | // FIXME: Consider assigning over existing elements, rather than clearing & |
410 | // re-initializing them - for all assign(...) variants. |
411 | |
412 | void assign(size_type NumElts, const T &Elt) { |
413 | clear(); |
414 | if (this->capacity() < NumElts) |
415 | this->grow(NumElts); |
416 | this->set_size(NumElts); |
417 | std::uninitialized_fill(this->begin(), this->end(), Elt); |
418 | } |
419 | |
420 | template <typename in_iter, |
421 | typename = typename std::enable_if<std::is_convertible< |
422 | typename std::iterator_traits<in_iter>::iterator_category, |
423 | std::input_iterator_tag>::value>::type> |
424 | void assign(in_iter in_start, in_iter in_end) { |
425 | clear(); |
426 | append(in_start, in_end); |
427 | } |
428 | |
429 | void assign(std::initializer_list<T> IL) { |
430 | clear(); |
431 | append(IL); |
432 | } |
433 | |
434 | iterator erase(const_iterator CI) { |
435 | // Just cast away constness because this is a non-const member function. |
436 | iterator I = const_cast<iterator>(CI); |
437 | |
438 | assert(I >= this->begin() && "Iterator to erase is out of bounds.")((I >= this->begin() && "Iterator to erase is out of bounds." ) ? static_cast<void> (0) : __assert_fail ("I >= this->begin() && \"Iterator to erase is out of bounds.\"" , "/build/llvm-toolchain-snapshot-10~svn373517/include/llvm/ADT/SmallVector.h" , 438, __PRETTY_FUNCTION__)); |
439 | assert(I < this->end() && "Erasing at past-the-end iterator.")((I < this->end() && "Erasing at past-the-end iterator." ) ? static_cast<void> (0) : __assert_fail ("I < this->end() && \"Erasing at past-the-end iterator.\"" , "/build/llvm-toolchain-snapshot-10~svn373517/include/llvm/ADT/SmallVector.h" , 439, __PRETTY_FUNCTION__)); |
440 | |
441 | iterator N = I; |
442 | // Shift all elts down one. |
443 | std::move(I+1, this->end(), I); |
444 | // Drop the last elt. |
445 | this->pop_back(); |
446 | return(N); |
447 | } |
448 | |
449 | iterator erase(const_iterator CS, const_iterator CE) { |
450 | // Just cast away constness because this is a non-const member function. |
451 | iterator S = const_cast<iterator>(CS); |
452 | iterator E = const_cast<iterator>(CE); |
453 | |
454 | assert(S >= this->begin() && "Range to erase is out of bounds.")((S >= this->begin() && "Range to erase is out of bounds." ) ? static_cast<void> (0) : __assert_fail ("S >= this->begin() && \"Range to erase is out of bounds.\"" , "/build/llvm-toolchain-snapshot-10~svn373517/include/llvm/ADT/SmallVector.h" , 454, __PRETTY_FUNCTION__)); |
455 | assert(S <= E && "Trying to erase invalid range.")((S <= E && "Trying to erase invalid range.") ? static_cast <void> (0) : __assert_fail ("S <= E && \"Trying to erase invalid range.\"" , "/build/llvm-toolchain-snapshot-10~svn373517/include/llvm/ADT/SmallVector.h" , 455, __PRETTY_FUNCTION__)); |
456 | assert(E <= this->end() && "Trying to erase past the end.")((E <= this->end() && "Trying to erase past the end." ) ? static_cast<void> (0) : __assert_fail ("E <= this->end() && \"Trying to erase past the end.\"" , "/build/llvm-toolchain-snapshot-10~svn373517/include/llvm/ADT/SmallVector.h" , 456, __PRETTY_FUNCTION__)); |
457 | |
458 | iterator N = S; |
459 | // Shift all elts down. |
460 | iterator I = std::move(E, this->end(), S); |
461 | // Drop the last elts. |
462 | this->destroy_range(I, this->end()); |
463 | this->set_size(I - this->begin()); |
464 | return(N); |
465 | } |
466 | |
467 | iterator insert(iterator I, T &&Elt) { |
468 | if (I == this->end()) { // Important special case for empty vector. |
469 | this->push_back(::std::move(Elt)); |
470 | return this->end()-1; |
471 | } |
472 | |
473 | assert(I >= this->begin() && "Insertion iterator is out of bounds.")((I >= this->begin() && "Insertion iterator is out of bounds." ) ? static_cast<void> (0) : __assert_fail ("I >= this->begin() && \"Insertion iterator is out of bounds.\"" , "/build/llvm-toolchain-snapshot-10~svn373517/include/llvm/ADT/SmallVector.h" , 473, __PRETTY_FUNCTION__)); |
474 | assert(I <= this->end() && "Inserting past the end of the vector.")((I <= this->end() && "Inserting past the end of the vector." ) ? static_cast<void> (0) : __assert_fail ("I <= this->end() && \"Inserting past the end of the vector.\"" , "/build/llvm-toolchain-snapshot-10~svn373517/include/llvm/ADT/SmallVector.h" , 474, __PRETTY_FUNCTION__)); |
475 | |
476 | if (this->size() >= this->capacity()) { |
477 | size_t EltNo = I-this->begin(); |
478 | this->grow(); |
479 | I = this->begin()+EltNo; |
480 | } |
481 | |
482 | ::new ((void*) this->end()) T(::std::move(this->back())); |
483 | // Push everything else over. |
484 | std::move_backward(I, this->end()-1, this->end()); |
485 | this->set_size(this->size() + 1); |
486 | |
487 | // If we just moved the element we're inserting, be sure to update |
488 | // the reference. |
489 | T *EltPtr = &Elt; |
490 | if (I <= EltPtr && EltPtr < this->end()) |
491 | ++EltPtr; |
492 | |
493 | *I = ::std::move(*EltPtr); |
494 | return I; |
495 | } |
496 | |
497 | iterator insert(iterator I, const T &Elt) { |
498 | if (I == this->end()) { // Important special case for empty vector. |
499 | this->push_back(Elt); |
500 | return this->end()-1; |
501 | } |
502 | |
503 | assert(I >= this->begin() && "Insertion iterator is out of bounds.")((I >= this->begin() && "Insertion iterator is out of bounds." ) ? static_cast<void> (0) : __assert_fail ("I >= this->begin() && \"Insertion iterator is out of bounds.\"" , "/build/llvm-toolchain-snapshot-10~svn373517/include/llvm/ADT/SmallVector.h" , 503, __PRETTY_FUNCTION__)); |
504 | assert(I <= this->end() && "Inserting past the end of the vector.")((I <= this->end() && "Inserting past the end of the vector." ) ? static_cast<void> (0) : __assert_fail ("I <= this->end() && \"Inserting past the end of the vector.\"" , "/build/llvm-toolchain-snapshot-10~svn373517/include/llvm/ADT/SmallVector.h" , 504, __PRETTY_FUNCTION__)); |
505 | |
506 | if (this->size() >= this->capacity()) { |
507 | size_t EltNo = I-this->begin(); |
508 | this->grow(); |
509 | I = this->begin()+EltNo; |
510 | } |
511 | ::new ((void*) this->end()) T(std::move(this->back())); |
512 | // Push everything else over. |
513 | std::move_backward(I, this->end()-1, this->end()); |
514 | this->set_size(this->size() + 1); |
515 | |
516 | // If we just moved the element we're inserting, be sure to update |
517 | // the reference. |
518 | const T *EltPtr = &Elt; |
519 | if (I <= EltPtr && EltPtr < this->end()) |
520 | ++EltPtr; |
521 | |
522 | *I = *EltPtr; |
523 | return I; |
524 | } |
525 | |
526 | iterator insert(iterator I, size_type NumToInsert, const T &Elt) { |
527 | // Convert iterator to elt# to avoid invalidating iterator when we reserve() |
528 | size_t InsertElt = I - this->begin(); |
529 | |
530 | if (I == this->end()) { // Important special case for empty vector. |
531 | append(NumToInsert, Elt); |
532 | return this->begin()+InsertElt; |
533 | } |
534 | |
535 | assert(I >= this->begin() && "Insertion iterator is out of bounds.")((I >= this->begin() && "Insertion iterator is out of bounds." ) ? static_cast<void> (0) : __assert_fail ("I >= this->begin() && \"Insertion iterator is out of bounds.\"" , "/build/llvm-toolchain-snapshot-10~svn373517/include/llvm/ADT/SmallVector.h" , 535, __PRETTY_FUNCTION__)); |
536 | assert(I <= this->end() && "Inserting past the end of the vector.")((I <= this->end() && "Inserting past the end of the vector." ) ? static_cast<void> (0) : __assert_fail ("I <= this->end() && \"Inserting past the end of the vector.\"" , "/build/llvm-toolchain-snapshot-10~svn373517/include/llvm/ADT/SmallVector.h" , 536, __PRETTY_FUNCTION__)); |
537 | |
538 | // Ensure there is enough space. |
539 | reserve(this->size() + NumToInsert); |
540 | |
541 | // Uninvalidate the iterator. |
542 | I = this->begin()+InsertElt; |
543 | |
544 | // If there are more elements between the insertion point and the end of the |
545 | // range than there are being inserted, we can use a simple approach to |
546 | // insertion. Since we already reserved space, we know that this won't |
547 | // reallocate the vector. |
548 | if (size_t(this->end()-I) >= NumToInsert) { |
549 | T *OldEnd = this->end(); |
550 | append(std::move_iterator<iterator>(this->end() - NumToInsert), |
551 | std::move_iterator<iterator>(this->end())); |
552 | |
553 | // Copy the existing elements that get replaced. |
554 | std::move_backward(I, OldEnd-NumToInsert, OldEnd); |
555 | |
556 | std::fill_n(I, NumToInsert, Elt); |
557 | return I; |
558 | } |
559 | |
560 | // Otherwise, we're inserting more elements than exist already, and we're |
561 | // not inserting at the end. |
562 | |
563 | // Move over the elements that we're about to overwrite. |
564 | T *OldEnd = this->end(); |
565 | this->set_size(this->size() + NumToInsert); |
566 | size_t NumOverwritten = OldEnd-I; |
567 | this->uninitialized_move(I, OldEnd, this->end()-NumOverwritten); |
568 | |
569 | // Replace the overwritten part. |
570 | std::fill_n(I, NumOverwritten, Elt); |
571 | |
572 | // Insert the non-overwritten middle part. |
573 | std::uninitialized_fill_n(OldEnd, NumToInsert-NumOverwritten, Elt); |
574 | return I; |
575 | } |
576 | |
577 | template <typename ItTy, |
578 | typename = typename std::enable_if<std::is_convertible< |
579 | typename std::iterator_traits<ItTy>::iterator_category, |
580 | std::input_iterator_tag>::value>::type> |
581 | iterator insert(iterator I, ItTy From, ItTy To) { |
582 | // Convert iterator to elt# to avoid invalidating iterator when we reserve() |
583 | size_t InsertElt = I - this->begin(); |
584 | |
585 | if (I == this->end()) { // Important special case for empty vector. |
586 | append(From, To); |
587 | return this->begin()+InsertElt; |
588 | } |
589 | |
590 | assert(I >= this->begin() && "Insertion iterator is out of bounds.")((I >= this->begin() && "Insertion iterator is out of bounds." ) ? static_cast<void> (0) : __assert_fail ("I >= this->begin() && \"Insertion iterator is out of bounds.\"" , "/build/llvm-toolchain-snapshot-10~svn373517/include/llvm/ADT/SmallVector.h" , 590, __PRETTY_FUNCTION__)); |
591 | assert(I <= this->end() && "Inserting past the end of the vector.")((I <= this->end() && "Inserting past the end of the vector." ) ? static_cast<void> (0) : __assert_fail ("I <= this->end() && \"Inserting past the end of the vector.\"" , "/build/llvm-toolchain-snapshot-10~svn373517/include/llvm/ADT/SmallVector.h" , 591, __PRETTY_FUNCTION__)); |
592 | |
593 | size_t NumToInsert = std::distance(From, To); |
594 | |
595 | // Ensure there is enough space. |
596 | reserve(this->size() + NumToInsert); |
597 | |
598 | // Uninvalidate the iterator. |
599 | I = this->begin()+InsertElt; |
600 | |
601 | // If there are more elements between the insertion point and the end of the |
602 | // range than there are being inserted, we can use a simple approach to |
603 | // insertion. Since we already reserved space, we know that this won't |
604 | // reallocate the vector. |
605 | if (size_t(this->end()-I) >= NumToInsert) { |
606 | T *OldEnd = this->end(); |
607 | append(std::move_iterator<iterator>(this->end() - NumToInsert), |
608 | std::move_iterator<iterator>(this->end())); |
609 | |
610 | // Copy the existing elements that get replaced. |
611 | std::move_backward(I, OldEnd-NumToInsert, OldEnd); |
612 | |
613 | std::copy(From, To, I); |
614 | return I; |
615 | } |
616 | |
617 | // Otherwise, we're inserting more elements than exist already, and we're |
618 | // not inserting at the end. |
619 | |
620 | // Move over the elements that we're about to overwrite. |
621 | T *OldEnd = this->end(); |
622 | this->set_size(this->size() + NumToInsert); |
623 | size_t NumOverwritten = OldEnd-I; |
624 | this->uninitialized_move(I, OldEnd, this->end()-NumOverwritten); |
625 | |
626 | // Replace the overwritten part. |
627 | for (T *J = I; NumOverwritten > 0; --NumOverwritten) { |
628 | *J = *From; |
629 | ++J; ++From; |
630 | } |
631 | |
632 | // Insert the non-overwritten middle part. |
633 | this->uninitialized_copy(From, To, OldEnd); |
634 | return I; |
635 | } |
636 | |
637 | void insert(iterator I, std::initializer_list<T> IL) { |
638 | insert(I, IL.begin(), IL.end()); |
639 | } |
640 | |
641 | template <typename... ArgTypes> reference emplace_back(ArgTypes &&... Args) { |
642 | if (LLVM_UNLIKELY(this->size() >= this->capacity())__builtin_expect((bool)(this->size() >= this->capacity ()), false)) |
643 | this->grow(); |
644 | ::new ((void *)this->end()) T(std::forward<ArgTypes>(Args)...); |
645 | this->set_size(this->size() + 1); |
646 | return this->back(); |
647 | } |
648 | |
649 | SmallVectorImpl &operator=(const SmallVectorImpl &RHS); |
650 | |
651 | SmallVectorImpl &operator=(SmallVectorImpl &&RHS); |
652 | |
653 | bool operator==(const SmallVectorImpl &RHS) const { |
654 | if (this->size() != RHS.size()) return false; |
655 | return std::equal(this->begin(), this->end(), RHS.begin()); |
656 | } |
657 | bool operator!=(const SmallVectorImpl &RHS) const { |
658 | return !(*this == RHS); |
659 | } |
660 | |
661 | bool operator<(const SmallVectorImpl &RHS) const { |
662 | return std::lexicographical_compare(this->begin(), this->end(), |
663 | RHS.begin(), RHS.end()); |
664 | } |
665 | }; |
666 | |
667 | template <typename T> |
668 | void SmallVectorImpl<T>::swap(SmallVectorImpl<T> &RHS) { |
669 | if (this == &RHS) return; |
670 | |
671 | // We can only avoid copying elements if neither vector is small. |
672 | if (!this->isSmall() && !RHS.isSmall()) { |
673 | std::swap(this->BeginX, RHS.BeginX); |
674 | std::swap(this->Size, RHS.Size); |
675 | std::swap(this->Capacity, RHS.Capacity); |
676 | return; |
677 | } |
678 | if (RHS.size() > this->capacity()) |
679 | this->grow(RHS.size()); |
680 | if (this->size() > RHS.capacity()) |
681 | RHS.grow(this->size()); |
682 | |
683 | // Swap the shared elements. |
684 | size_t NumShared = this->size(); |
685 | if (NumShared > RHS.size()) NumShared = RHS.size(); |
686 | for (size_type i = 0; i != NumShared; ++i) |
687 | std::swap((*this)[i], RHS[i]); |
688 | |
689 | // Copy over the extra elts. |
690 | if (this->size() > RHS.size()) { |
691 | size_t EltDiff = this->size() - RHS.size(); |
692 | this->uninitialized_copy(this->begin()+NumShared, this->end(), RHS.end()); |
693 | RHS.set_size(RHS.size() + EltDiff); |
694 | this->destroy_range(this->begin()+NumShared, this->end()); |
695 | this->set_size(NumShared); |
696 | } else if (RHS.size() > this->size()) { |
697 | size_t EltDiff = RHS.size() - this->size(); |
698 | this->uninitialized_copy(RHS.begin()+NumShared, RHS.end(), this->end()); |
699 | this->set_size(this->size() + EltDiff); |
700 | this->destroy_range(RHS.begin()+NumShared, RHS.end()); |
701 | RHS.set_size(NumShared); |
702 | } |
703 | } |
704 | |
705 | template <typename T> |
706 | SmallVectorImpl<T> &SmallVectorImpl<T>:: |
707 | operator=(const SmallVectorImpl<T> &RHS) { |
708 | // Avoid self-assignment. |
709 | if (this == &RHS) return *this; |
710 | |
711 | // If we already have sufficient space, assign the common elements, then |
712 | // destroy any excess. |
713 | size_t RHSSize = RHS.size(); |
714 | size_t CurSize = this->size(); |
715 | if (CurSize >= RHSSize) { |
716 | // Assign common elements. |
717 | iterator NewEnd; |
718 | if (RHSSize) |
719 | NewEnd = std::copy(RHS.begin(), RHS.begin()+RHSSize, this->begin()); |
720 | else |
721 | NewEnd = this->begin(); |
722 | |
723 | // Destroy excess elements. |
724 | this->destroy_range(NewEnd, this->end()); |
725 | |
726 | // Trim. |
727 | this->set_size(RHSSize); |
728 | return *this; |
729 | } |
730 | |
731 | // If we have to grow to have enough elements, destroy the current elements. |
732 | // This allows us to avoid copying them during the grow. |
733 | // FIXME: don't do this if they're efficiently moveable. |
734 | if (this->capacity() < RHSSize) { |
735 | // Destroy current elements. |
736 | this->destroy_range(this->begin(), this->end()); |
737 | this->set_size(0); |
738 | CurSize = 0; |
739 | this->grow(RHSSize); |
740 | } else if (CurSize) { |
741 | // Otherwise, use assignment for the already-constructed elements. |
742 | std::copy(RHS.begin(), RHS.begin()+CurSize, this->begin()); |
743 | } |
744 | |
745 | // Copy construct the new elements in place. |
746 | this->uninitialized_copy(RHS.begin()+CurSize, RHS.end(), |
747 | this->begin()+CurSize); |
748 | |
749 | // Set end. |
750 | this->set_size(RHSSize); |
751 | return *this; |
752 | } |
753 | |
754 | template <typename T> |
755 | SmallVectorImpl<T> &SmallVectorImpl<T>::operator=(SmallVectorImpl<T> &&RHS) { |
756 | // Avoid self-assignment. |
757 | if (this == &RHS) return *this; |
758 | |
759 | // If the RHS isn't small, clear this vector and then steal its buffer. |
760 | if (!RHS.isSmall()) { |
761 | this->destroy_range(this->begin(), this->end()); |
762 | if (!this->isSmall()) free(this->begin()); |
763 | this->BeginX = RHS.BeginX; |
764 | this->Size = RHS.Size; |
765 | this->Capacity = RHS.Capacity; |
766 | RHS.resetToSmall(); |
767 | return *this; |
768 | } |
769 | |
770 | // If we already have sufficient space, assign the common elements, then |
771 | // destroy any excess. |
772 | size_t RHSSize = RHS.size(); |
773 | size_t CurSize = this->size(); |
774 | if (CurSize >= RHSSize) { |
775 | // Assign common elements. |
776 | iterator NewEnd = this->begin(); |
777 | if (RHSSize) |
778 | NewEnd = std::move(RHS.begin(), RHS.end(), NewEnd); |
779 | |
780 | // Destroy excess elements and trim the bounds. |
781 | this->destroy_range(NewEnd, this->end()); |
782 | this->set_size(RHSSize); |
783 | |
784 | // Clear the RHS. |
785 | RHS.clear(); |
786 | |
787 | return *this; |
788 | } |
789 | |
790 | // If we have to grow to have enough elements, destroy the current elements. |
791 | // This allows us to avoid copying them during the grow. |
792 | // FIXME: this may not actually make any sense if we can efficiently move |
793 | // elements. |
794 | if (this->capacity() < RHSSize) { |
795 | // Destroy current elements. |
796 | this->destroy_range(this->begin(), this->end()); |
797 | this->set_size(0); |
798 | CurSize = 0; |
799 | this->grow(RHSSize); |
800 | } else if (CurSize) { |
801 | // Otherwise, use assignment for the already-constructed elements. |
802 | std::move(RHS.begin(), RHS.begin()+CurSize, this->begin()); |
803 | } |
804 | |
805 | // Move-construct the new elements in place. |
806 | this->uninitialized_move(RHS.begin()+CurSize, RHS.end(), |
807 | this->begin()+CurSize); |
808 | |
809 | // Set end. |
810 | this->set_size(RHSSize); |
811 | |
812 | RHS.clear(); |
813 | return *this; |
814 | } |
815 | |
816 | /// Storage for the SmallVector elements. This is specialized for the N=0 case |
817 | /// to avoid allocating unnecessary storage. |
818 | template <typename T, unsigned N> |
819 | struct SmallVectorStorage { |
820 | AlignedCharArrayUnion<T> InlineElts[N]; |
821 | }; |
822 | |
823 | /// We need the storage to be properly aligned even for small-size of 0 so that |
824 | /// the pointer math in \a SmallVectorTemplateCommon::getFirstEl() is |
825 | /// well-defined. |
826 | template <typename T> struct alignas(alignof(T)) SmallVectorStorage<T, 0> {}; |
827 | |
828 | /// This is a 'vector' (really, a variable-sized array), optimized |
829 | /// for the case when the array is small. It contains some number of elements |
830 | /// in-place, which allows it to avoid heap allocation when the actual number of |
831 | /// elements is below that threshold. This allows normal "small" cases to be |
832 | /// fast without losing generality for large inputs. |
833 | /// |
834 | /// Note that this does not attempt to be exception safe. |
835 | /// |
836 | template <typename T, unsigned N> |
837 | class SmallVector : public SmallVectorImpl<T>, SmallVectorStorage<T, N> { |
838 | public: |
839 | SmallVector() : SmallVectorImpl<T>(N) {} |
840 | |
841 | ~SmallVector() { |
842 | // Destroy the constructed elements in the vector. |
843 | this->destroy_range(this->begin(), this->end()); |
844 | } |
845 | |
846 | explicit SmallVector(size_t Size, const T &Value = T()) |
847 | : SmallVectorImpl<T>(N) { |
848 | this->assign(Size, Value); |
849 | } |
850 | |
851 | template <typename ItTy, |
852 | typename = typename std::enable_if<std::is_convertible< |
853 | typename std::iterator_traits<ItTy>::iterator_category, |
854 | std::input_iterator_tag>::value>::type> |
855 | SmallVector(ItTy S, ItTy E) : SmallVectorImpl<T>(N) { |
856 | this->append(S, E); |
857 | } |
858 | |
859 | template <typename RangeTy> |
860 | explicit SmallVector(const iterator_range<RangeTy> &R) |
861 | : SmallVectorImpl<T>(N) { |
862 | this->append(R.begin(), R.end()); |
863 | } |
864 | |
865 | SmallVector(std::initializer_list<T> IL) : SmallVectorImpl<T>(N) { |
866 | this->assign(IL); |
867 | } |
868 | |
869 | SmallVector(const SmallVector &RHS) : SmallVectorImpl<T>(N) { |
870 | if (!RHS.empty()) |
871 | SmallVectorImpl<T>::operator=(RHS); |
872 | } |
873 | |
874 | const SmallVector &operator=(const SmallVector &RHS) { |
875 | SmallVectorImpl<T>::operator=(RHS); |
876 | return *this; |
877 | } |
878 | |
879 | SmallVector(SmallVector &&RHS) : SmallVectorImpl<T>(N) { |
880 | if (!RHS.empty()) |
881 | SmallVectorImpl<T>::operator=(::std::move(RHS)); |
882 | } |
883 | |
884 | SmallVector(SmallVectorImpl<T> &&RHS) : SmallVectorImpl<T>(N) { |
885 | if (!RHS.empty()) |
886 | SmallVectorImpl<T>::operator=(::std::move(RHS)); |
887 | } |
888 | |
889 | const SmallVector &operator=(SmallVector &&RHS) { |
890 | SmallVectorImpl<T>::operator=(::std::move(RHS)); |
891 | return *this; |
892 | } |
893 | |
894 | const SmallVector &operator=(SmallVectorImpl<T> &&RHS) { |
895 | SmallVectorImpl<T>::operator=(::std::move(RHS)); |
896 | return *this; |
897 | } |
898 | |
899 | const SmallVector &operator=(std::initializer_list<T> IL) { |
900 | this->assign(IL); |
901 | return *this; |
902 | } |
903 | }; |
904 | |
905 | template <typename T, unsigned N> |
906 | inline size_t capacity_in_bytes(const SmallVector<T, N> &X) { |
907 | return X.capacity_in_bytes(); |
908 | } |
909 | |
910 | } // end namespace llvm |
911 | |
912 | namespace std { |
913 | |
914 | /// Implement std::swap in terms of SmallVector swap. |
915 | template<typename T> |
916 | inline void |
917 | swap(llvm::SmallVectorImpl<T> &LHS, llvm::SmallVectorImpl<T> &RHS) { |
918 | LHS.swap(RHS); |
919 | } |
920 | |
921 | /// Implement std::swap in terms of SmallVector swap. |
922 | template<typename T, unsigned N> |
923 | inline void |
924 | swap(llvm::SmallVector<T, N> &LHS, llvm::SmallVector<T, N> &RHS) { |
925 | LHS.swap(RHS); |
926 | } |
927 | |
928 | } // end namespace std |
929 | |
930 | #endif // LLVM_ADT_SMALLVECTOR_H |