File: | lib/Transforms/Vectorize/LoopVectorize.cpp |
Location: | line 5604, column 75 |
Description: | Division by zero |
1 | //===- LoopVectorize.cpp - A Loop Vectorizer ------------------------------===// | |||
2 | // | |||
3 | // The LLVM Compiler Infrastructure | |||
4 | // | |||
5 | // This file is distributed under the University of Illinois Open Source | |||
6 | // License. See LICENSE.TXT for details. | |||
7 | // | |||
8 | //===----------------------------------------------------------------------===// | |||
9 | // | |||
10 | // This is the LLVM loop vectorizer. This pass modifies 'vectorizable' loops | |||
11 | // and generates target-independent LLVM-IR. | |||
12 | // The vectorizer uses the TargetTransformInfo analysis to estimate the costs | |||
13 | // of instructions in order to estimate the profitability of vectorization. | |||
14 | // | |||
15 | // The loop vectorizer combines consecutive loop iterations into a single | |||
16 | // 'wide' iteration. After this transformation the index is incremented | |||
17 | // by the SIMD vector width, and not by one. | |||
18 | // | |||
19 | // This pass has three parts: | |||
20 | // 1. The main loop pass that drives the different parts. | |||
21 | // 2. LoopVectorizationLegality - A unit that checks for the legality | |||
22 | // of the vectorization. | |||
23 | // 3. InnerLoopVectorizer - A unit that performs the actual | |||
24 | // widening of instructions. | |||
25 | // 4. LoopVectorizationCostModel - A unit that checks for the profitability | |||
26 | // of vectorization. It decides on the optimal vector width, which | |||
27 | // can be one, if vectorization is not profitable. | |||
28 | // | |||
29 | //===----------------------------------------------------------------------===// | |||
30 | // | |||
31 | // The reduction-variable vectorization is based on the paper: | |||
32 | // D. Nuzman and R. Henderson. Multi-platform Auto-vectorization. | |||
33 | // | |||
34 | // Variable uniformity checks are inspired by: | |||
35 | // Karrenberg, R. and Hack, S. Whole Function Vectorization. | |||
36 | // | |||
37 | // Other ideas/concepts are from: | |||
38 | // A. Zaks and D. Nuzman. Autovectorization in GCC-two years later. | |||
39 | // | |||
40 | // S. Maleki, Y. Gao, M. Garzaran, T. Wong and D. Padua. An Evaluation of | |||
41 | // Vectorizing Compilers. | |||
42 | // | |||
43 | //===----------------------------------------------------------------------===// | |||
44 | ||||
45 | #include "llvm/Transforms/Vectorize.h" | |||
46 | #include "llvm/ADT/DenseMap.h" | |||
47 | #include "llvm/ADT/EquivalenceClasses.h" | |||
48 | #include "llvm/ADT/Hashing.h" | |||
49 | #include "llvm/ADT/MapVector.h" | |||
50 | #include "llvm/ADT/SetVector.h" | |||
51 | #include "llvm/ADT/SmallPtrSet.h" | |||
52 | #include "llvm/ADT/SmallSet.h" | |||
53 | #include "llvm/ADT/SmallVector.h" | |||
54 | #include "llvm/ADT/Statistic.h" | |||
55 | #include "llvm/ADT/StringExtras.h" | |||
56 | #include "llvm/Analysis/AliasAnalysis.h" | |||
57 | #include "llvm/Analysis/AliasSetTracker.h" | |||
58 | #include "llvm/Analysis/BlockFrequencyInfo.h" | |||
59 | #include "llvm/Analysis/LoopInfo.h" | |||
60 | #include "llvm/Analysis/LoopIterator.h" | |||
61 | #include "llvm/Analysis/LoopPass.h" | |||
62 | #include "llvm/Analysis/ScalarEvolution.h" | |||
63 | #include "llvm/Analysis/ScalarEvolutionExpander.h" | |||
64 | #include "llvm/Analysis/ScalarEvolutionExpressions.h" | |||
65 | #include "llvm/Analysis/TargetTransformInfo.h" | |||
66 | #include "llvm/Analysis/ValueTracking.h" | |||
67 | #include "llvm/IR/Constants.h" | |||
68 | #include "llvm/IR/DataLayout.h" | |||
69 | #include "llvm/IR/DebugInfo.h" | |||
70 | #include "llvm/IR/DerivedTypes.h" | |||
71 | #include "llvm/IR/DiagnosticInfo.h" | |||
72 | #include "llvm/IR/Dominators.h" | |||
73 | #include "llvm/IR/Function.h" | |||
74 | #include "llvm/IR/IRBuilder.h" | |||
75 | #include "llvm/IR/Instructions.h" | |||
76 | #include "llvm/IR/IntrinsicInst.h" | |||
77 | #include "llvm/IR/LLVMContext.h" | |||
78 | #include "llvm/IR/Module.h" | |||
79 | #include "llvm/IR/PatternMatch.h" | |||
80 | #include "llvm/IR/Type.h" | |||
81 | #include "llvm/IR/Value.h" | |||
82 | #include "llvm/IR/ValueHandle.h" | |||
83 | #include "llvm/IR/Verifier.h" | |||
84 | #include "llvm/Pass.h" | |||
85 | #include "llvm/Support/BranchProbability.h" | |||
86 | #include "llvm/Support/CommandLine.h" | |||
87 | #include "llvm/Support/Debug.h" | |||
88 | #include "llvm/Support/raw_ostream.h" | |||
89 | #include "llvm/Transforms/Scalar.h" | |||
90 | #include "llvm/Transforms/Utils/BasicBlockUtils.h" | |||
91 | #include "llvm/Transforms/Utils/Local.h" | |||
92 | #include "llvm/Transforms/Utils/VectorUtils.h" | |||
93 | #include <algorithm> | |||
94 | #include <map> | |||
95 | #include <tuple> | |||
96 | ||||
97 | using namespace llvm; | |||
98 | using namespace llvm::PatternMatch; | |||
99 | ||||
100 | #define LV_NAME"loop-vectorize" "loop-vectorize" | |||
101 | #define DEBUG_TYPE"loop-vectorize" LV_NAME"loop-vectorize" | |||
102 | ||||
103 | STATISTIC(LoopsVectorized, "Number of loops vectorized")static llvm::Statistic LoopsVectorized = { "loop-vectorize", "Number of loops vectorized" , 0, 0 }; | |||
104 | STATISTIC(LoopsAnalyzed, "Number of loops analyzed for vectorization")static llvm::Statistic LoopsAnalyzed = { "loop-vectorize", "Number of loops analyzed for vectorization" , 0, 0 }; | |||
105 | ||||
106 | static cl::opt<unsigned> | |||
107 | VectorizationFactor("force-vector-width", cl::init(0), cl::Hidden, | |||
108 | cl::desc("Sets the SIMD width. Zero is autoselect.")); | |||
109 | ||||
110 | static cl::opt<unsigned> | |||
111 | VectorizationInterleave("force-vector-interleave", cl::init(0), cl::Hidden, | |||
112 | cl::desc("Sets the vectorization interleave count. " | |||
113 | "Zero is autoselect.")); | |||
114 | ||||
115 | static cl::opt<bool> | |||
116 | EnableIfConversion("enable-if-conversion", cl::init(true), cl::Hidden, | |||
117 | cl::desc("Enable if-conversion during vectorization.")); | |||
118 | ||||
119 | /// We don't vectorize loops with a known constant trip count below this number. | |||
120 | static cl::opt<unsigned> | |||
121 | TinyTripCountVectorThreshold("vectorizer-min-trip-count", cl::init(16), | |||
122 | cl::Hidden, | |||
123 | cl::desc("Don't vectorize loops with a constant " | |||
124 | "trip count that is smaller than this " | |||
125 | "value.")); | |||
126 | ||||
127 | /// This enables versioning on the strides of symbolically striding memory | |||
128 | /// accesses in code like the following. | |||
129 | /// for (i = 0; i < N; ++i) | |||
130 | /// A[i * Stride1] += B[i * Stride2] ... | |||
131 | /// | |||
132 | /// Will be roughly translated to | |||
133 | /// if (Stride1 == 1 && Stride2 == 1) { | |||
134 | /// for (i = 0; i < N; i+=4) | |||
135 | /// A[i:i+3] += ... | |||
136 | /// } else | |||
137 | /// ... | |||
138 | static cl::opt<bool> EnableMemAccessVersioning( | |||
139 | "enable-mem-access-versioning", cl::init(true), cl::Hidden, | |||
140 | cl::desc("Enable symblic stride memory access versioning")); | |||
141 | ||||
142 | /// We don't unroll loops with a known constant trip count below this number. | |||
143 | static const unsigned TinyTripCountUnrollThreshold = 128; | |||
144 | ||||
145 | /// When performing memory disambiguation checks at runtime do not make more | |||
146 | /// than this number of comparisons. | |||
147 | static const unsigned RuntimeMemoryCheckThreshold = 8; | |||
148 | ||||
149 | /// Maximum simd width. | |||
150 | static const unsigned MaxVectorWidth = 64; | |||
151 | ||||
152 | static cl::opt<unsigned> ForceTargetNumScalarRegs( | |||
153 | "force-target-num-scalar-regs", cl::init(0), cl::Hidden, | |||
154 | cl::desc("A flag that overrides the target's number of scalar registers.")); | |||
155 | ||||
156 | static cl::opt<unsigned> ForceTargetNumVectorRegs( | |||
157 | "force-target-num-vector-regs", cl::init(0), cl::Hidden, | |||
158 | cl::desc("A flag that overrides the target's number of vector registers.")); | |||
159 | ||||
160 | /// Maximum vectorization interleave count. | |||
161 | static const unsigned MaxInterleaveFactor = 16; | |||
162 | ||||
163 | static cl::opt<unsigned> ForceTargetMaxScalarInterleaveFactor( | |||
164 | "force-target-max-scalar-interleave", cl::init(0), cl::Hidden, | |||
165 | cl::desc("A flag that overrides the target's max interleave factor for " | |||
166 | "scalar loops.")); | |||
167 | ||||
168 | static cl::opt<unsigned> ForceTargetMaxVectorInterleaveFactor( | |||
169 | "force-target-max-vector-interleave", cl::init(0), cl::Hidden, | |||
170 | cl::desc("A flag that overrides the target's max interleave factor for " | |||
171 | "vectorized loops.")); | |||
172 | ||||
173 | static cl::opt<unsigned> ForceTargetInstructionCost( | |||
174 | "force-target-instruction-cost", cl::init(0), cl::Hidden, | |||
175 | cl::desc("A flag that overrides the target's expected cost for " | |||
176 | "an instruction to a single constant value. Mostly " | |||
177 | "useful for getting consistent testing.")); | |||
178 | ||||
179 | static cl::opt<unsigned> SmallLoopCost( | |||
180 | "small-loop-cost", cl::init(20), cl::Hidden, | |||
181 | cl::desc("The cost of a loop that is considered 'small' by the unroller.")); | |||
182 | ||||
183 | static cl::opt<bool> LoopVectorizeWithBlockFrequency( | |||
184 | "loop-vectorize-with-block-frequency", cl::init(false), cl::Hidden, | |||
185 | cl::desc("Enable the use of the block frequency analysis to access PGO " | |||
186 | "heuristics minimizing code growth in cold regions and being more " | |||
187 | "aggressive in hot regions.")); | |||
188 | ||||
189 | // Runtime unroll loops for load/store throughput. | |||
190 | static cl::opt<bool> EnableLoadStoreRuntimeUnroll( | |||
191 | "enable-loadstore-runtime-unroll", cl::init(true), cl::Hidden, | |||
192 | cl::desc("Enable runtime unrolling until load/store ports are saturated")); | |||
193 | ||||
194 | /// The number of stores in a loop that are allowed to need predication. | |||
195 | static cl::opt<unsigned> NumberOfStoresToPredicate( | |||
196 | "vectorize-num-stores-pred", cl::init(1), cl::Hidden, | |||
197 | cl::desc("Max number of stores to be predicated behind an if.")); | |||
198 | ||||
199 | static cl::opt<bool> EnableIndVarRegisterHeur( | |||
200 | "enable-ind-var-reg-heur", cl::init(true), cl::Hidden, | |||
201 | cl::desc("Count the induction variable only once when unrolling")); | |||
202 | ||||
203 | static cl::opt<bool> EnableCondStoresVectorization( | |||
204 | "enable-cond-stores-vec", cl::init(false), cl::Hidden, | |||
205 | cl::desc("Enable if predication of stores during vectorization.")); | |||
206 | ||||
207 | static cl::opt<unsigned> MaxNestedScalarReductionUF( | |||
208 | "max-nested-scalar-reduction-unroll", cl::init(2), cl::Hidden, | |||
209 | cl::desc("The maximum unroll factor to use when unrolling a scalar " | |||
210 | "reduction in a nested loop.")); | |||
211 | ||||
212 | namespace { | |||
213 | ||||
214 | // Forward declarations. | |||
215 | class LoopVectorizationLegality; | |||
216 | class LoopVectorizationCostModel; | |||
217 | class LoopVectorizeHints; | |||
218 | ||||
219 | /// Optimization analysis message produced during vectorization. Messages inform | |||
220 | /// the user why vectorization did not occur. | |||
221 | class Report { | |||
222 | std::string Message; | |||
223 | raw_string_ostream Out; | |||
224 | Instruction *Instr; | |||
225 | ||||
226 | public: | |||
227 | Report(Instruction *I = nullptr) : Out(Message), Instr(I) { | |||
228 | Out << "loop not vectorized: "; | |||
229 | } | |||
230 | ||||
231 | template <typename A> Report &operator<<(const A &Value) { | |||
232 | Out << Value; | |||
233 | return *this; | |||
234 | } | |||
235 | ||||
236 | Instruction *getInstr() { return Instr; } | |||
237 | ||||
238 | std::string &str() { return Out.str(); } | |||
239 | operator Twine() { return Out.str(); } | |||
240 | }; | |||
241 | ||||
242 | /// InnerLoopVectorizer vectorizes loops which contain only one basic | |||
243 | /// block to a specified vectorization factor (VF). | |||
244 | /// This class performs the widening of scalars into vectors, or multiple | |||
245 | /// scalars. This class also implements the following features: | |||
246 | /// * It inserts an epilogue loop for handling loops that don't have iteration | |||
247 | /// counts that are known to be a multiple of the vectorization factor. | |||
248 | /// * It handles the code generation for reduction variables. | |||
249 | /// * Scalarization (implementation using scalars) of un-vectorizable | |||
250 | /// instructions. | |||
251 | /// InnerLoopVectorizer does not perform any vectorization-legality | |||
252 | /// checks, and relies on the caller to check for the different legality | |||
253 | /// aspects. The InnerLoopVectorizer relies on the | |||
254 | /// LoopVectorizationLegality class to provide information about the induction | |||
255 | /// and reduction variables that were found to a given vectorization factor. | |||
256 | class InnerLoopVectorizer { | |||
257 | public: | |||
258 | InnerLoopVectorizer(Loop *OrigLoop, ScalarEvolution *SE, LoopInfo *LI, | |||
259 | DominatorTree *DT, const DataLayout *DL, | |||
260 | const TargetLibraryInfo *TLI, unsigned VecWidth, | |||
261 | unsigned UnrollFactor) | |||
262 | : OrigLoop(OrigLoop), SE(SE), LI(LI), DT(DT), DL(DL), TLI(TLI), | |||
263 | VF(VecWidth), UF(UnrollFactor), Builder(SE->getContext()), | |||
264 | Induction(nullptr), OldInduction(nullptr), WidenMap(UnrollFactor), | |||
265 | Legal(nullptr) {} | |||
266 | ||||
267 | // Perform the actual loop widening (vectorization). | |||
268 | void vectorize(LoopVectorizationLegality *L) { | |||
269 | Legal = L; | |||
270 | // Create a new empty loop. Unlink the old loop and connect the new one. | |||
271 | createEmptyLoop(); | |||
272 | // Widen each instruction in the old loop to a new one in the new loop. | |||
273 | // Use the Legality module to find the induction and reduction variables. | |||
274 | vectorizeLoop(); | |||
275 | // Register the new loop and update the analysis passes. | |||
276 | updateAnalysis(); | |||
277 | } | |||
278 | ||||
279 | virtual ~InnerLoopVectorizer() {} | |||
280 | ||||
281 | protected: | |||
282 | /// A small list of PHINodes. | |||
283 | typedef SmallVector<PHINode*, 4> PhiVector; | |||
284 | /// When we unroll loops we have multiple vector values for each scalar. | |||
285 | /// This data structure holds the unrolled and vectorized values that | |||
286 | /// originated from one scalar instruction. | |||
287 | typedef SmallVector<Value*, 2> VectorParts; | |||
288 | ||||
289 | // When we if-convert we need create edge masks. We have to cache values so | |||
290 | // that we don't end up with exponential recursion/IR. | |||
291 | typedef DenseMap<std::pair<BasicBlock*, BasicBlock*>, | |||
292 | VectorParts> EdgeMaskCache; | |||
293 | ||||
294 | /// \brief Add code that checks at runtime if the accessed arrays overlap. | |||
295 | /// | |||
296 | /// Returns a pair of instructions where the first element is the first | |||
297 | /// instruction generated in possibly a sequence of instructions and the | |||
298 | /// second value is the final comparator value or NULL if no check is needed. | |||
299 | std::pair<Instruction *, Instruction *> addRuntimeCheck(Instruction *Loc); | |||
300 | ||||
301 | /// \brief Add checks for strides that where assumed to be 1. | |||
302 | /// | |||
303 | /// Returns the last check instruction and the first check instruction in the | |||
304 | /// pair as (first, last). | |||
305 | std::pair<Instruction *, Instruction *> addStrideCheck(Instruction *Loc); | |||
306 | ||||
307 | /// Create an empty loop, based on the loop ranges of the old loop. | |||
308 | void createEmptyLoop(); | |||
309 | /// Copy and widen the instructions from the old loop. | |||
310 | virtual void vectorizeLoop(); | |||
311 | ||||
312 | /// \brief The Loop exit block may have single value PHI nodes where the | |||
313 | /// incoming value is 'Undef'. While vectorizing we only handled real values | |||
314 | /// that were defined inside the loop. Here we fix the 'undef case'. | |||
315 | /// See PR14725. | |||
316 | void fixLCSSAPHIs(); | |||
317 | ||||
318 | /// A helper function that computes the predicate of the block BB, assuming | |||
319 | /// that the header block of the loop is set to True. It returns the *entry* | |||
320 | /// mask for the block BB. | |||
321 | VectorParts createBlockInMask(BasicBlock *BB); | |||
322 | /// A helper function that computes the predicate of the edge between SRC | |||
323 | /// and DST. | |||
324 | VectorParts createEdgeMask(BasicBlock *Src, BasicBlock *Dst); | |||
325 | ||||
326 | /// A helper function to vectorize a single BB within the innermost loop. | |||
327 | void vectorizeBlockInLoop(BasicBlock *BB, PhiVector *PV); | |||
328 | ||||
329 | /// Vectorize a single PHINode in a block. This method handles the induction | |||
330 | /// variable canonicalization. It supports both VF = 1 for unrolled loops and | |||
331 | /// arbitrary length vectors. | |||
332 | void widenPHIInstruction(Instruction *PN, VectorParts &Entry, | |||
333 | unsigned UF, unsigned VF, PhiVector *PV); | |||
334 | ||||
335 | /// Insert the new loop to the loop hierarchy and pass manager | |||
336 | /// and update the analysis passes. | |||
337 | void updateAnalysis(); | |||
338 | ||||
339 | /// This instruction is un-vectorizable. Implement it as a sequence | |||
340 | /// of scalars. If \p IfPredicateStore is true we need to 'hide' each | |||
341 | /// scalarized instruction behind an if block predicated on the control | |||
342 | /// dependence of the instruction. | |||
343 | virtual void scalarizeInstruction(Instruction *Instr, | |||
344 | bool IfPredicateStore=false); | |||
345 | ||||
346 | /// Vectorize Load and Store instructions, | |||
347 | virtual void vectorizeMemoryInstruction(Instruction *Instr); | |||
348 | ||||
349 | /// Create a broadcast instruction. This method generates a broadcast | |||
350 | /// instruction (shuffle) for loop invariant values and for the induction | |||
351 | /// value. If this is the induction variable then we extend it to N, N+1, ... | |||
352 | /// this is needed because each iteration in the loop corresponds to a SIMD | |||
353 | /// element. | |||
354 | virtual Value *getBroadcastInstrs(Value *V); | |||
355 | ||||
356 | /// This function adds 0, 1, 2 ... to each vector element, starting at zero. | |||
357 | /// If Negate is set then negative numbers are added e.g. (0, -1, -2, ...). | |||
358 | /// The sequence starts at StartIndex. | |||
359 | virtual Value *getConsecutiveVector(Value* Val, int StartIdx, bool Negate); | |||
360 | ||||
361 | /// When we go over instructions in the basic block we rely on previous | |||
362 | /// values within the current basic block or on loop invariant values. | |||
363 | /// When we widen (vectorize) values we place them in the map. If the values | |||
364 | /// are not within the map, they have to be loop invariant, so we simply | |||
365 | /// broadcast them into a vector. | |||
366 | VectorParts &getVectorValue(Value *V); | |||
367 | ||||
368 | /// Generate a shuffle sequence that will reverse the vector Vec. | |||
369 | virtual Value *reverseVector(Value *Vec); | |||
370 | ||||
371 | /// This is a helper class that holds the vectorizer state. It maps scalar | |||
372 | /// instructions to vector instructions. When the code is 'unrolled' then | |||
373 | /// then a single scalar value is mapped to multiple vector parts. The parts | |||
374 | /// are stored in the VectorPart type. | |||
375 | struct ValueMap { | |||
376 | /// C'tor. UnrollFactor controls the number of vectors ('parts') that | |||
377 | /// are mapped. | |||
378 | ValueMap(unsigned UnrollFactor) : UF(UnrollFactor) {} | |||
379 | ||||
380 | /// \return True if 'Key' is saved in the Value Map. | |||
381 | bool has(Value *Key) const { return MapStorage.count(Key); } | |||
382 | ||||
383 | /// Initializes a new entry in the map. Sets all of the vector parts to the | |||
384 | /// save value in 'Val'. | |||
385 | /// \return A reference to a vector with splat values. | |||
386 | VectorParts &splat(Value *Key, Value *Val) { | |||
387 | VectorParts &Entry = MapStorage[Key]; | |||
388 | Entry.assign(UF, Val); | |||
389 | return Entry; | |||
390 | } | |||
391 | ||||
392 | ///\return A reference to the value that is stored at 'Key'. | |||
393 | VectorParts &get(Value *Key) { | |||
394 | VectorParts &Entry = MapStorage[Key]; | |||
395 | if (Entry.empty()) | |||
396 | Entry.resize(UF); | |||
397 | assert(Entry.size() == UF)((Entry.size() == UF) ? static_cast<void> (0) : __assert_fail ("Entry.size() == UF", "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 397, __PRETTY_FUNCTION__)); | |||
398 | return Entry; | |||
399 | } | |||
400 | ||||
401 | private: | |||
402 | /// The unroll factor. Each entry in the map stores this number of vector | |||
403 | /// elements. | |||
404 | unsigned UF; | |||
405 | ||||
406 | /// Map storage. We use std::map and not DenseMap because insertions to a | |||
407 | /// dense map invalidates its iterators. | |||
408 | std::map<Value *, VectorParts> MapStorage; | |||
409 | }; | |||
410 | ||||
411 | /// The original loop. | |||
412 | Loop *OrigLoop; | |||
413 | /// Scev analysis to use. | |||
414 | ScalarEvolution *SE; | |||
415 | /// Loop Info. | |||
416 | LoopInfo *LI; | |||
417 | /// Dominator Tree. | |||
418 | DominatorTree *DT; | |||
419 | /// Alias Analysis. | |||
420 | AliasAnalysis *AA; | |||
421 | /// Data Layout. | |||
422 | const DataLayout *DL; | |||
423 | /// Target Library Info. | |||
424 | const TargetLibraryInfo *TLI; | |||
425 | ||||
426 | /// The vectorization SIMD factor to use. Each vector will have this many | |||
427 | /// vector elements. | |||
428 | unsigned VF; | |||
429 | ||||
430 | protected: | |||
431 | /// The vectorization unroll factor to use. Each scalar is vectorized to this | |||
432 | /// many different vector instructions. | |||
433 | unsigned UF; | |||
434 | ||||
435 | /// The builder that we use | |||
436 | IRBuilder<> Builder; | |||
437 | ||||
438 | // --- Vectorization state --- | |||
439 | ||||
440 | /// The vector-loop preheader. | |||
441 | BasicBlock *LoopVectorPreHeader; | |||
442 | /// The scalar-loop preheader. | |||
443 | BasicBlock *LoopScalarPreHeader; | |||
444 | /// Middle Block between the vector and the scalar. | |||
445 | BasicBlock *LoopMiddleBlock; | |||
446 | ///The ExitBlock of the scalar loop. | |||
447 | BasicBlock *LoopExitBlock; | |||
448 | ///The vector loop body. | |||
449 | SmallVector<BasicBlock *, 4> LoopVectorBody; | |||
450 | ///The scalar loop body. | |||
451 | BasicBlock *LoopScalarBody; | |||
452 | /// A list of all bypass blocks. The first block is the entry of the loop. | |||
453 | SmallVector<BasicBlock *, 4> LoopBypassBlocks; | |||
454 | ||||
455 | /// The new Induction variable which was added to the new block. | |||
456 | PHINode *Induction; | |||
457 | /// The induction variable of the old basic block. | |||
458 | PHINode *OldInduction; | |||
459 | /// Holds the extended (to the widest induction type) start index. | |||
460 | Value *ExtendedIdx; | |||
461 | /// Maps scalars to widened vectors. | |||
462 | ValueMap WidenMap; | |||
463 | EdgeMaskCache MaskCache; | |||
464 | ||||
465 | LoopVectorizationLegality *Legal; | |||
466 | }; | |||
467 | ||||
468 | class InnerLoopUnroller : public InnerLoopVectorizer { | |||
469 | public: | |||
470 | InnerLoopUnroller(Loop *OrigLoop, ScalarEvolution *SE, LoopInfo *LI, | |||
471 | DominatorTree *DT, const DataLayout *DL, | |||
472 | const TargetLibraryInfo *TLI, unsigned UnrollFactor) : | |||
473 | InnerLoopVectorizer(OrigLoop, SE, LI, DT, DL, TLI, 1, UnrollFactor) { } | |||
474 | ||||
475 | private: | |||
476 | void scalarizeInstruction(Instruction *Instr, | |||
477 | bool IfPredicateStore = false) override; | |||
478 | void vectorizeMemoryInstruction(Instruction *Instr) override; | |||
479 | Value *getBroadcastInstrs(Value *V) override; | |||
480 | Value *getConsecutiveVector(Value* Val, int StartIdx, bool Negate) override; | |||
481 | Value *reverseVector(Value *Vec) override; | |||
482 | }; | |||
483 | ||||
484 | /// \brief Look for a meaningful debug location on the instruction or it's | |||
485 | /// operands. | |||
486 | static Instruction *getDebugLocFromInstOrOperands(Instruction *I) { | |||
487 | if (!I) | |||
488 | return I; | |||
489 | ||||
490 | DebugLoc Empty; | |||
491 | if (I->getDebugLoc() != Empty) | |||
492 | return I; | |||
493 | ||||
494 | for (User::op_iterator OI = I->op_begin(), OE = I->op_end(); OI != OE; ++OI) { | |||
495 | if (Instruction *OpInst = dyn_cast<Instruction>(*OI)) | |||
496 | if (OpInst->getDebugLoc() != Empty) | |||
497 | return OpInst; | |||
498 | } | |||
499 | ||||
500 | return I; | |||
501 | } | |||
502 | ||||
503 | /// \brief Set the debug location in the builder using the debug location in the | |||
504 | /// instruction. | |||
505 | static void setDebugLocFromInst(IRBuilder<> &B, const Value *Ptr) { | |||
506 | if (const Instruction *Inst = dyn_cast_or_null<Instruction>(Ptr)) | |||
507 | B.SetCurrentDebugLocation(Inst->getDebugLoc()); | |||
508 | else | |||
509 | B.SetCurrentDebugLocation(DebugLoc()); | |||
510 | } | |||
511 | ||||
512 | #ifndef NDEBUG | |||
513 | /// \return string containing a file name and a line # for the given loop. | |||
514 | static std::string getDebugLocString(const Loop *L) { | |||
515 | std::string Result; | |||
516 | if (L) { | |||
517 | raw_string_ostream OS(Result); | |||
518 | const DebugLoc LoopDbgLoc = L->getStartLoc(); | |||
519 | if (!LoopDbgLoc.isUnknown()) | |||
520 | LoopDbgLoc.print(L->getHeader()->getContext(), OS); | |||
521 | else | |||
522 | // Just print the module name. | |||
523 | OS << L->getHeader()->getParent()->getParent()->getModuleIdentifier(); | |||
524 | OS.flush(); | |||
525 | } | |||
526 | return Result; | |||
527 | } | |||
528 | #endif | |||
529 | ||||
530 | /// \brief Propagate known metadata from one instruction to another. | |||
531 | static void propagateMetadata(Instruction *To, const Instruction *From) { | |||
532 | SmallVector<std::pair<unsigned, MDNode *>, 4> Metadata; | |||
533 | From->getAllMetadataOtherThanDebugLoc(Metadata); | |||
534 | ||||
535 | for (auto M : Metadata) { | |||
536 | unsigned Kind = M.first; | |||
537 | ||||
538 | // These are safe to transfer (this is safe for TBAA, even when we | |||
539 | // if-convert, because should that metadata have had a control dependency | |||
540 | // on the condition, and thus actually aliased with some other | |||
541 | // non-speculated memory access when the condition was false, this would be | |||
542 | // caught by the runtime overlap checks). | |||
543 | if (Kind != LLVMContext::MD_tbaa && | |||
544 | Kind != LLVMContext::MD_alias_scope && | |||
545 | Kind != LLVMContext::MD_noalias && | |||
546 | Kind != LLVMContext::MD_fpmath) | |||
547 | continue; | |||
548 | ||||
549 | To->setMetadata(Kind, M.second); | |||
550 | } | |||
551 | } | |||
552 | ||||
553 | /// \brief Propagate known metadata from one instruction to a vector of others. | |||
554 | static void propagateMetadata(SmallVectorImpl<Value *> &To, const Instruction *From) { | |||
555 | for (Value *V : To) | |||
556 | if (Instruction *I = dyn_cast<Instruction>(V)) | |||
557 | propagateMetadata(I, From); | |||
558 | } | |||
559 | ||||
560 | /// LoopVectorizationLegality checks if it is legal to vectorize a loop, and | |||
561 | /// to what vectorization factor. | |||
562 | /// This class does not look at the profitability of vectorization, only the | |||
563 | /// legality. This class has two main kinds of checks: | |||
564 | /// * Memory checks - The code in canVectorizeMemory checks if vectorization | |||
565 | /// will change the order of memory accesses in a way that will change the | |||
566 | /// correctness of the program. | |||
567 | /// * Scalars checks - The code in canVectorizeInstrs and canVectorizeMemory | |||
568 | /// checks for a number of different conditions, such as the availability of a | |||
569 | /// single induction variable, that all types are supported and vectorize-able, | |||
570 | /// etc. This code reflects the capabilities of InnerLoopVectorizer. | |||
571 | /// This class is also used by InnerLoopVectorizer for identifying | |||
572 | /// induction variable and the different reduction variables. | |||
573 | class LoopVectorizationLegality { | |||
574 | public: | |||
575 | unsigned NumLoads; | |||
576 | unsigned NumStores; | |||
577 | unsigned NumPredStores; | |||
578 | ||||
579 | LoopVectorizationLegality(Loop *L, ScalarEvolution *SE, const DataLayout *DL, | |||
580 | DominatorTree *DT, TargetLibraryInfo *TLI, | |||
581 | AliasAnalysis *AA, Function *F) | |||
582 | : NumLoads(0), NumStores(0), NumPredStores(0), TheLoop(L), SE(SE), DL(DL), | |||
583 | DT(DT), TLI(TLI), AA(AA), TheFunction(F), Induction(nullptr), | |||
584 | WidestIndTy(nullptr), HasFunNoNaNAttr(false), MaxSafeDepDistBytes(-1U) { | |||
585 | } | |||
586 | ||||
587 | /// This enum represents the kinds of reductions that we support. | |||
588 | enum ReductionKind { | |||
589 | RK_NoReduction, ///< Not a reduction. | |||
590 | RK_IntegerAdd, ///< Sum of integers. | |||
591 | RK_IntegerMult, ///< Product of integers. | |||
592 | RK_IntegerOr, ///< Bitwise or logical OR of numbers. | |||
593 | RK_IntegerAnd, ///< Bitwise or logical AND of numbers. | |||
594 | RK_IntegerXor, ///< Bitwise or logical XOR of numbers. | |||
595 | RK_IntegerMinMax, ///< Min/max implemented in terms of select(cmp()). | |||
596 | RK_FloatAdd, ///< Sum of floats. | |||
597 | RK_FloatMult, ///< Product of floats. | |||
598 | RK_FloatMinMax ///< Min/max implemented in terms of select(cmp()). | |||
599 | }; | |||
600 | ||||
601 | /// This enum represents the kinds of inductions that we support. | |||
602 | enum InductionKind { | |||
603 | IK_NoInduction, ///< Not an induction variable. | |||
604 | IK_IntInduction, ///< Integer induction variable. Step = 1. | |||
605 | IK_ReverseIntInduction, ///< Reverse int induction variable. Step = -1. | |||
606 | IK_PtrInduction, ///< Pointer induction var. Step = sizeof(elem). | |||
607 | IK_ReversePtrInduction ///< Reverse ptr indvar. Step = - sizeof(elem). | |||
608 | }; | |||
609 | ||||
610 | // This enum represents the kind of minmax reduction. | |||
611 | enum MinMaxReductionKind { | |||
612 | MRK_Invalid, | |||
613 | MRK_UIntMin, | |||
614 | MRK_UIntMax, | |||
615 | MRK_SIntMin, | |||
616 | MRK_SIntMax, | |||
617 | MRK_FloatMin, | |||
618 | MRK_FloatMax | |||
619 | }; | |||
620 | ||||
621 | /// This struct holds information about reduction variables. | |||
622 | struct ReductionDescriptor { | |||
623 | ReductionDescriptor() : StartValue(nullptr), LoopExitInstr(nullptr), | |||
624 | Kind(RK_NoReduction), MinMaxKind(MRK_Invalid) {} | |||
625 | ||||
626 | ReductionDescriptor(Value *Start, Instruction *Exit, ReductionKind K, | |||
627 | MinMaxReductionKind MK) | |||
628 | : StartValue(Start), LoopExitInstr(Exit), Kind(K), MinMaxKind(MK) {} | |||
629 | ||||
630 | // The starting value of the reduction. | |||
631 | // It does not have to be zero! | |||
632 | TrackingVH<Value> StartValue; | |||
633 | // The instruction who's value is used outside the loop. | |||
634 | Instruction *LoopExitInstr; | |||
635 | // The kind of the reduction. | |||
636 | ReductionKind Kind; | |||
637 | // If this a min/max reduction the kind of reduction. | |||
638 | MinMaxReductionKind MinMaxKind; | |||
639 | }; | |||
640 | ||||
641 | /// This POD struct holds information about a potential reduction operation. | |||
642 | struct ReductionInstDesc { | |||
643 | ReductionInstDesc(bool IsRedux, Instruction *I) : | |||
644 | IsReduction(IsRedux), PatternLastInst(I), MinMaxKind(MRK_Invalid) {} | |||
645 | ||||
646 | ReductionInstDesc(Instruction *I, MinMaxReductionKind K) : | |||
647 | IsReduction(true), PatternLastInst(I), MinMaxKind(K) {} | |||
648 | ||||
649 | // Is this instruction a reduction candidate. | |||
650 | bool IsReduction; | |||
651 | // The last instruction in a min/max pattern (select of the select(icmp()) | |||
652 | // pattern), or the current reduction instruction otherwise. | |||
653 | Instruction *PatternLastInst; | |||
654 | // If this is a min/max pattern the comparison predicate. | |||
655 | MinMaxReductionKind MinMaxKind; | |||
656 | }; | |||
657 | ||||
658 | /// This struct holds information about the memory runtime legality | |||
659 | /// check that a group of pointers do not overlap. | |||
660 | struct RuntimePointerCheck { | |||
661 | RuntimePointerCheck() : Need(false) {} | |||
662 | ||||
663 | /// Reset the state of the pointer runtime information. | |||
664 | void reset() { | |||
665 | Need = false; | |||
666 | Pointers.clear(); | |||
667 | Starts.clear(); | |||
668 | Ends.clear(); | |||
669 | IsWritePtr.clear(); | |||
670 | DependencySetId.clear(); | |||
671 | AliasSetId.clear(); | |||
672 | } | |||
673 | ||||
674 | /// Insert a pointer and calculate the start and end SCEVs. | |||
675 | void insert(ScalarEvolution *SE, Loop *Lp, Value *Ptr, bool WritePtr, | |||
676 | unsigned DepSetId, unsigned ASId, ValueToValueMap &Strides); | |||
677 | ||||
678 | /// This flag indicates if we need to add the runtime check. | |||
679 | bool Need; | |||
680 | /// Holds the pointers that we need to check. | |||
681 | SmallVector<TrackingVH<Value>, 2> Pointers; | |||
682 | /// Holds the pointer value at the beginning of the loop. | |||
683 | SmallVector<const SCEV*, 2> Starts; | |||
684 | /// Holds the pointer value at the end of the loop. | |||
685 | SmallVector<const SCEV*, 2> Ends; | |||
686 | /// Holds the information if this pointer is used for writing to memory. | |||
687 | SmallVector<bool, 2> IsWritePtr; | |||
688 | /// Holds the id of the set of pointers that could be dependent because of a | |||
689 | /// shared underlying object. | |||
690 | SmallVector<unsigned, 2> DependencySetId; | |||
691 | /// Holds the id of the disjoint alias set to which this pointer belongs. | |||
692 | SmallVector<unsigned, 2> AliasSetId; | |||
693 | }; | |||
694 | ||||
695 | /// A struct for saving information about induction variables. | |||
696 | struct InductionInfo { | |||
697 | InductionInfo(Value *Start, InductionKind K) : StartValue(Start), IK(K) {} | |||
698 | InductionInfo() : StartValue(nullptr), IK(IK_NoInduction) {} | |||
699 | /// Start value. | |||
700 | TrackingVH<Value> StartValue; | |||
701 | /// Induction kind. | |||
702 | InductionKind IK; | |||
703 | }; | |||
704 | ||||
705 | /// ReductionList contains the reduction descriptors for all | |||
706 | /// of the reductions that were found in the loop. | |||
707 | typedef DenseMap<PHINode*, ReductionDescriptor> ReductionList; | |||
708 | ||||
709 | /// InductionList saves induction variables and maps them to the | |||
710 | /// induction descriptor. | |||
711 | typedef MapVector<PHINode*, InductionInfo> InductionList; | |||
712 | ||||
713 | /// Returns true if it is legal to vectorize this loop. | |||
714 | /// This does not mean that it is profitable to vectorize this | |||
715 | /// loop, only that it is legal to do so. | |||
716 | bool canVectorize(); | |||
717 | ||||
718 | /// Returns the Induction variable. | |||
719 | PHINode *getInduction() { return Induction; } | |||
720 | ||||
721 | /// Returns the reduction variables found in the loop. | |||
722 | ReductionList *getReductionVars() { return &Reductions; } | |||
723 | ||||
724 | /// Returns the induction variables found in the loop. | |||
725 | InductionList *getInductionVars() { return &Inductions; } | |||
726 | ||||
727 | /// Returns the widest induction type. | |||
728 | Type *getWidestInductionType() { return WidestIndTy; } | |||
729 | ||||
730 | /// Returns True if V is an induction variable in this loop. | |||
731 | bool isInductionVariable(const Value *V); | |||
732 | ||||
733 | /// Return true if the block BB needs to be predicated in order for the loop | |||
734 | /// to be vectorized. | |||
735 | bool blockNeedsPredication(BasicBlock *BB); | |||
736 | ||||
737 | /// Check if this pointer is consecutive when vectorizing. This happens | |||
738 | /// when the last index of the GEP is the induction variable, or that the | |||
739 | /// pointer itself is an induction variable. | |||
740 | /// This check allows us to vectorize A[idx] into a wide load/store. | |||
741 | /// Returns: | |||
742 | /// 0 - Stride is unknown or non-consecutive. | |||
743 | /// 1 - Address is consecutive. | |||
744 | /// -1 - Address is consecutive, and decreasing. | |||
745 | int isConsecutivePtr(Value *Ptr); | |||
746 | ||||
747 | /// Returns true if the value V is uniform within the loop. | |||
748 | bool isUniform(Value *V); | |||
749 | ||||
750 | /// Returns true if this instruction will remain scalar after vectorization. | |||
751 | bool isUniformAfterVectorization(Instruction* I) { return Uniforms.count(I); } | |||
752 | ||||
753 | /// Returns the information that we collected about runtime memory check. | |||
754 | RuntimePointerCheck *getRuntimePointerCheck() { return &PtrRtCheck; } | |||
755 | ||||
756 | /// This function returns the identity element (or neutral element) for | |||
757 | /// the operation K. | |||
758 | static Constant *getReductionIdentity(ReductionKind K, Type *Tp); | |||
759 | ||||
760 | unsigned getMaxSafeDepDistBytes() { return MaxSafeDepDistBytes; } | |||
761 | ||||
762 | bool hasStride(Value *V) { return StrideSet.count(V); } | |||
763 | bool mustCheckStrides() { return !StrideSet.empty(); } | |||
764 | SmallPtrSet<Value *, 8>::iterator strides_begin() { | |||
765 | return StrideSet.begin(); | |||
766 | } | |||
767 | SmallPtrSet<Value *, 8>::iterator strides_end() { return StrideSet.end(); } | |||
768 | ||||
769 | private: | |||
770 | /// Check if a single basic block loop is vectorizable. | |||
771 | /// At this point we know that this is a loop with a constant trip count | |||
772 | /// and we only need to check individual instructions. | |||
773 | bool canVectorizeInstrs(); | |||
774 | ||||
775 | /// When we vectorize loops we may change the order in which | |||
776 | /// we read and write from memory. This method checks if it is | |||
777 | /// legal to vectorize the code, considering only memory constrains. | |||
778 | /// Returns true if the loop is vectorizable | |||
779 | bool canVectorizeMemory(); | |||
780 | ||||
781 | /// Return true if we can vectorize this loop using the IF-conversion | |||
782 | /// transformation. | |||
783 | bool canVectorizeWithIfConvert(); | |||
784 | ||||
785 | /// Collect the variables that need to stay uniform after vectorization. | |||
786 | void collectLoopUniforms(); | |||
787 | ||||
788 | /// Return true if all of the instructions in the block can be speculatively | |||
789 | /// executed. \p SafePtrs is a list of addresses that are known to be legal | |||
790 | /// and we know that we can read from them without segfault. | |||
791 | bool blockCanBePredicated(BasicBlock *BB, SmallPtrSetImpl<Value *> &SafePtrs); | |||
792 | ||||
793 | /// Returns True, if 'Phi' is the kind of reduction variable for type | |||
794 | /// 'Kind'. If this is a reduction variable, it adds it to ReductionList. | |||
795 | bool AddReductionVar(PHINode *Phi, ReductionKind Kind); | |||
796 | /// Returns a struct describing if the instruction 'I' can be a reduction | |||
797 | /// variable of type 'Kind'. If the reduction is a min/max pattern of | |||
798 | /// select(icmp()) this function advances the instruction pointer 'I' from the | |||
799 | /// compare instruction to the select instruction and stores this pointer in | |||
800 | /// 'PatternLastInst' member of the returned struct. | |||
801 | ReductionInstDesc isReductionInstr(Instruction *I, ReductionKind Kind, | |||
802 | ReductionInstDesc &Desc); | |||
803 | /// Returns true if the instruction is a Select(ICmp(X, Y), X, Y) instruction | |||
804 | /// pattern corresponding to a min(X, Y) or max(X, Y). | |||
805 | static ReductionInstDesc isMinMaxSelectCmpPattern(Instruction *I, | |||
806 | ReductionInstDesc &Prev); | |||
807 | /// Returns the induction kind of Phi. This function may return NoInduction | |||
808 | /// if the PHI is not an induction variable. | |||
809 | InductionKind isInductionVariable(PHINode *Phi); | |||
810 | ||||
811 | /// \brief Collect memory access with loop invariant strides. | |||
812 | /// | |||
813 | /// Looks for accesses like "a[i * StrideA]" where "StrideA" is loop | |||
814 | /// invariant. | |||
815 | void collectStridedAcccess(Value *LoadOrStoreInst); | |||
816 | ||||
817 | /// Report an analysis message to assist the user in diagnosing loops that are | |||
818 | /// not vectorized. | |||
819 | void emitAnalysis(Report &Message) { | |||
820 | DebugLoc DL = TheLoop->getStartLoc(); | |||
821 | if (Instruction *I = Message.getInstr()) | |||
822 | DL = I->getDebugLoc(); | |||
823 | emitOptimizationRemarkAnalysis(TheFunction->getContext(), DEBUG_TYPE"loop-vectorize", | |||
824 | *TheFunction, DL, Message.str()); | |||
825 | } | |||
826 | ||||
827 | /// The loop that we evaluate. | |||
828 | Loop *TheLoop; | |||
829 | /// Scev analysis. | |||
830 | ScalarEvolution *SE; | |||
831 | /// DataLayout analysis. | |||
832 | const DataLayout *DL; | |||
833 | /// Dominators. | |||
834 | DominatorTree *DT; | |||
835 | /// Target Library Info. | |||
836 | TargetLibraryInfo *TLI; | |||
837 | /// Alias analysis. | |||
838 | AliasAnalysis *AA; | |||
839 | /// Parent function | |||
840 | Function *TheFunction; | |||
841 | ||||
842 | // --- vectorization state --- // | |||
843 | ||||
844 | /// Holds the integer induction variable. This is the counter of the | |||
845 | /// loop. | |||
846 | PHINode *Induction; | |||
847 | /// Holds the reduction variables. | |||
848 | ReductionList Reductions; | |||
849 | /// Holds all of the induction variables that we found in the loop. | |||
850 | /// Notice that inductions don't need to start at zero and that induction | |||
851 | /// variables can be pointers. | |||
852 | InductionList Inductions; | |||
853 | /// Holds the widest induction type encountered. | |||
854 | Type *WidestIndTy; | |||
855 | ||||
856 | /// Allowed outside users. This holds the reduction | |||
857 | /// vars which can be accessed from outside the loop. | |||
858 | SmallPtrSet<Value*, 4> AllowedExit; | |||
859 | /// This set holds the variables which are known to be uniform after | |||
860 | /// vectorization. | |||
861 | SmallPtrSet<Instruction*, 4> Uniforms; | |||
862 | /// We need to check that all of the pointers in this list are disjoint | |||
863 | /// at runtime. | |||
864 | RuntimePointerCheck PtrRtCheck; | |||
865 | /// Can we assume the absence of NaNs. | |||
866 | bool HasFunNoNaNAttr; | |||
867 | ||||
868 | unsigned MaxSafeDepDistBytes; | |||
869 | ||||
870 | ValueToValueMap Strides; | |||
871 | SmallPtrSet<Value *, 8> StrideSet; | |||
872 | }; | |||
873 | ||||
874 | /// LoopVectorizationCostModel - estimates the expected speedups due to | |||
875 | /// vectorization. | |||
876 | /// In many cases vectorization is not profitable. This can happen because of | |||
877 | /// a number of reasons. In this class we mainly attempt to predict the | |||
878 | /// expected speedup/slowdowns due to the supported instruction set. We use the | |||
879 | /// TargetTransformInfo to query the different backends for the cost of | |||
880 | /// different operations. | |||
881 | class LoopVectorizationCostModel { | |||
882 | public: | |||
883 | LoopVectorizationCostModel(Loop *L, ScalarEvolution *SE, LoopInfo *LI, | |||
884 | LoopVectorizationLegality *Legal, | |||
885 | const TargetTransformInfo &TTI, | |||
886 | const DataLayout *DL, const TargetLibraryInfo *TLI, | |||
887 | const Function *F, const LoopVectorizeHints *Hints) | |||
888 | : TheLoop(L), SE(SE), LI(LI), Legal(Legal), TTI(TTI), DL(DL), TLI(TLI), TheFunction(F), Hints(Hints) {} | |||
889 | ||||
890 | /// Information about vectorization costs | |||
891 | struct VectorizationFactor { | |||
892 | unsigned Width; // Vector width with best cost | |||
893 | unsigned Cost; // Cost of the loop with that width | |||
894 | }; | |||
895 | /// \return The most profitable vectorization factor and the cost of that VF. | |||
896 | /// This method checks every power of two up to VF. If UserVF is not ZERO | |||
897 | /// then this vectorization factor will be selected if vectorization is | |||
898 | /// possible. | |||
899 | VectorizationFactor selectVectorizationFactor(bool OptForSize); | |||
900 | ||||
901 | /// \return The size (in bits) of the widest type in the code that | |||
902 | /// needs to be vectorized. We ignore values that remain scalar such as | |||
903 | /// 64 bit loop indices. | |||
904 | unsigned getWidestType(); | |||
905 | ||||
906 | /// \return The most profitable unroll factor. | |||
907 | /// If UserUF is non-zero then this method finds the best unroll-factor | |||
908 | /// based on register pressure and other parameters. | |||
909 | /// VF and LoopCost are the selected vectorization factor and the cost of the | |||
910 | /// selected VF. | |||
911 | unsigned selectUnrollFactor(bool OptForSize, unsigned VF, unsigned LoopCost); | |||
912 | ||||
913 | /// \brief A struct that represents some properties of the register usage | |||
914 | /// of a loop. | |||
915 | struct RegisterUsage { | |||
916 | /// Holds the number of loop invariant values that are used in the loop. | |||
917 | unsigned LoopInvariantRegs; | |||
918 | /// Holds the maximum number of concurrent live intervals in the loop. | |||
919 | unsigned MaxLocalUsers; | |||
920 | /// Holds the number of instructions in the loop. | |||
921 | unsigned NumInstructions; | |||
922 | }; | |||
923 | ||||
924 | /// \return information about the register usage of the loop. | |||
925 | RegisterUsage calculateRegisterUsage(); | |||
926 | ||||
927 | private: | |||
928 | /// Returns the expected execution cost. The unit of the cost does | |||
929 | /// not matter because we use the 'cost' units to compare different | |||
930 | /// vector widths. The cost that is returned is *not* normalized by | |||
931 | /// the factor width. | |||
932 | unsigned expectedCost(unsigned VF); | |||
933 | ||||
934 | /// Returns the execution time cost of an instruction for a given vector | |||
935 | /// width. Vector width of one means scalar. | |||
936 | unsigned getInstructionCost(Instruction *I, unsigned VF); | |||
937 | ||||
938 | /// A helper function for converting Scalar types to vector types. | |||
939 | /// If the incoming type is void, we return void. If the VF is 1, we return | |||
940 | /// the scalar type. | |||
941 | static Type* ToVectorTy(Type *Scalar, unsigned VF); | |||
942 | ||||
943 | /// Returns whether the instruction is a load or store and will be a emitted | |||
944 | /// as a vector operation. | |||
945 | bool isConsecutiveLoadOrStore(Instruction *I); | |||
946 | ||||
947 | /// Report an analysis message to assist the user in diagnosing loops that are | |||
948 | /// not vectorized. | |||
949 | void emitAnalysis(Report &Message) { | |||
950 | DebugLoc DL = TheLoop->getStartLoc(); | |||
951 | if (Instruction *I = Message.getInstr()) | |||
952 | DL = I->getDebugLoc(); | |||
953 | emitOptimizationRemarkAnalysis(TheFunction->getContext(), DEBUG_TYPE"loop-vectorize", | |||
954 | *TheFunction, DL, Message.str()); | |||
955 | } | |||
956 | ||||
957 | /// The loop that we evaluate. | |||
958 | Loop *TheLoop; | |||
959 | /// Scev analysis. | |||
960 | ScalarEvolution *SE; | |||
961 | /// Loop Info analysis. | |||
962 | LoopInfo *LI; | |||
963 | /// Vectorization legality. | |||
964 | LoopVectorizationLegality *Legal; | |||
965 | /// Vector target information. | |||
966 | const TargetTransformInfo &TTI; | |||
967 | /// Target data layout information. | |||
968 | const DataLayout *DL; | |||
969 | /// Target Library Info. | |||
970 | const TargetLibraryInfo *TLI; | |||
971 | const Function *TheFunction; | |||
972 | // Loop Vectorize Hint. | |||
973 | const LoopVectorizeHints *Hints; | |||
974 | }; | |||
975 | ||||
976 | /// Utility class for getting and setting loop vectorizer hints in the form | |||
977 | /// of loop metadata. | |||
978 | /// This class keeps a number of loop annotations locally (as member variables) | |||
979 | /// and can, upon request, write them back as metadata on the loop. It will | |||
980 | /// initially scan the loop for existing metadata, and will update the local | |||
981 | /// values based on information in the loop. | |||
982 | /// We cannot write all values to metadata, as the mere presence of some info, | |||
983 | /// for example 'force', means a decision has been made. So, we need to be | |||
984 | /// careful NOT to add them if the user hasn't specifically asked so. | |||
985 | class LoopVectorizeHints { | |||
986 | enum HintKind { | |||
987 | HK_WIDTH, | |||
988 | HK_UNROLL, | |||
989 | HK_FORCE | |||
990 | }; | |||
991 | ||||
992 | /// Hint - associates name and validation with the hint value. | |||
993 | struct Hint { | |||
994 | const char * Name; | |||
995 | unsigned Value; // This may have to change for non-numeric values. | |||
996 | HintKind Kind; | |||
997 | ||||
998 | Hint(const char * Name, unsigned Value, HintKind Kind) | |||
999 | : Name(Name), Value(Value), Kind(Kind) { } | |||
1000 | ||||
1001 | bool validate(unsigned Val) { | |||
1002 | switch (Kind) { | |||
1003 | case HK_WIDTH: | |||
1004 | return isPowerOf2_32(Val) && Val <= MaxVectorWidth; | |||
1005 | case HK_UNROLL: | |||
1006 | return isPowerOf2_32(Val) && Val <= MaxInterleaveFactor; | |||
1007 | case HK_FORCE: | |||
1008 | return (Val <= 1); | |||
1009 | } | |||
1010 | return false; | |||
1011 | } | |||
1012 | }; | |||
1013 | ||||
1014 | /// Vectorization width. | |||
1015 | Hint Width; | |||
1016 | /// Vectorization interleave factor. | |||
1017 | Hint Interleave; | |||
1018 | /// Vectorization forced | |||
1019 | Hint Force; | |||
1020 | /// Array to help iterating through all hints. | |||
1021 | Hint *Hints[3]; // avoiding initialisation due to MSVC2012 | |||
1022 | ||||
1023 | /// Return the loop metadata prefix. | |||
1024 | static StringRef Prefix() { return "llvm.loop."; } | |||
1025 | ||||
1026 | public: | |||
1027 | enum ForceKind { | |||
1028 | FK_Undefined = -1, ///< Not selected. | |||
1029 | FK_Disabled = 0, ///< Forcing disabled. | |||
1030 | FK_Enabled = 1, ///< Forcing enabled. | |||
1031 | }; | |||
1032 | ||||
1033 | LoopVectorizeHints(const Loop *L, bool DisableInterleaving) | |||
1034 | : Width("vectorize.width", VectorizationFactor, HK_WIDTH), | |||
1035 | Interleave("interleave.count", DisableInterleaving, HK_UNROLL), | |||
1036 | Force("vectorize.enable", FK_Undefined, HK_FORCE), | |||
1037 | TheLoop(L) { | |||
1038 | // FIXME: Move this up initialisation when MSVC requirement is 2013+ | |||
1039 | Hints[0] = &Width; | |||
1040 | Hints[1] = &Interleave; | |||
1041 | Hints[2] = &Force; | |||
1042 | ||||
1043 | // Populate values with existing loop metadata. | |||
1044 | getHintsFromMetadata(); | |||
1045 | ||||
1046 | // force-vector-interleave overrides DisableInterleaving. | |||
1047 | if (VectorizationInterleave.getNumOccurrences() > 0) | |||
1048 | Interleave.Value = VectorizationInterleave; | |||
1049 | ||||
1050 | DEBUG(if (DisableInterleaving && Interleave.Value == 1) dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { if (DisableInterleaving && Interleave .Value == 1) dbgs() << "LV: Interleaving disabled by the pass manager\n" ; } } while (0) | |||
1051 | << "LV: Interleaving disabled by the pass manager\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { if (DisableInterleaving && Interleave .Value == 1) dbgs() << "LV: Interleaving disabled by the pass manager\n" ; } } while (0); | |||
1052 | } | |||
1053 | ||||
1054 | /// Mark the loop L as already vectorized by setting the width to 1. | |||
1055 | void setAlreadyVectorized() { | |||
1056 | Width.Value = Interleave.Value = 1; | |||
1057 | // FIXME: Change all lines below for this when we can use MSVC 2013+ | |||
1058 | //writeHintsToMetadata({ Width, Unroll }); | |||
1059 | std::vector<Hint> hints; | |||
1060 | hints.reserve(2); | |||
1061 | hints.emplace_back(Width); | |||
1062 | hints.emplace_back(Interleave); | |||
1063 | writeHintsToMetadata(std::move(hints)); | |||
1064 | } | |||
1065 | ||||
1066 | /// Dumps all the hint information. | |||
1067 | std::string emitRemark() const { | |||
1068 | Report R; | |||
1069 | if (Force.Value == LoopVectorizeHints::FK_Disabled) | |||
1070 | R << "vectorization is explicitly disabled"; | |||
1071 | else { | |||
1072 | R << "use -Rpass-analysis=loop-vectorize for more info"; | |||
1073 | if (Force.Value == LoopVectorizeHints::FK_Enabled) { | |||
1074 | R << " (Force=true"; | |||
1075 | if (Width.Value != 0) | |||
1076 | R << ", Vector Width=" << Width.Value; | |||
1077 | if (Interleave.Value != 0) | |||
1078 | R << ", Interleave Count=" << Interleave.Value; | |||
1079 | R << ")"; | |||
1080 | } | |||
1081 | } | |||
1082 | ||||
1083 | return R.str(); | |||
1084 | } | |||
1085 | ||||
1086 | unsigned getWidth() const { return Width.Value; } | |||
1087 | unsigned getInterleave() const { return Interleave.Value; } | |||
1088 | enum ForceKind getForce() const { return (ForceKind)Force.Value; } | |||
1089 | ||||
1090 | private: | |||
1091 | /// Find hints specified in the loop metadata and update local values. | |||
1092 | void getHintsFromMetadata() { | |||
1093 | MDNode *LoopID = TheLoop->getLoopID(); | |||
1094 | if (!LoopID) | |||
1095 | return; | |||
1096 | ||||
1097 | // First operand should refer to the loop id itself. | |||
1098 | assert(LoopID->getNumOperands() > 0 && "requires at least one operand")((LoopID->getNumOperands() > 0 && "requires at least one operand" ) ? static_cast<void> (0) : __assert_fail ("LoopID->getNumOperands() > 0 && \"requires at least one operand\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1098, __PRETTY_FUNCTION__)); | |||
1099 | assert(LoopID->getOperand(0) == LoopID && "invalid loop id")((LoopID->getOperand(0) == LoopID && "invalid loop id" ) ? static_cast<void> (0) : __assert_fail ("LoopID->getOperand(0) == LoopID && \"invalid loop id\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1099, __PRETTY_FUNCTION__)); | |||
1100 | ||||
1101 | for (unsigned i = 1, ie = LoopID->getNumOperands(); i < ie; ++i) { | |||
1102 | const MDString *S = nullptr; | |||
1103 | SmallVector<Value*, 4> Args; | |||
1104 | ||||
1105 | // The expected hint is either a MDString or a MDNode with the first | |||
1106 | // operand a MDString. | |||
1107 | if (const MDNode *MD = dyn_cast<MDNode>(LoopID->getOperand(i))) { | |||
1108 | if (!MD || MD->getNumOperands() == 0) | |||
1109 | continue; | |||
1110 | S = dyn_cast<MDString>(MD->getOperand(0)); | |||
1111 | for (unsigned i = 1, ie = MD->getNumOperands(); i < ie; ++i) | |||
1112 | Args.push_back(MD->getOperand(i)); | |||
1113 | } else { | |||
1114 | S = dyn_cast<MDString>(LoopID->getOperand(i)); | |||
1115 | assert(Args.size() == 0 && "too many arguments for MDString")((Args.size() == 0 && "too many arguments for MDString" ) ? static_cast<void> (0) : __assert_fail ("Args.size() == 0 && \"too many arguments for MDString\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1115, __PRETTY_FUNCTION__)); | |||
1116 | } | |||
1117 | ||||
1118 | if (!S) | |||
1119 | continue; | |||
1120 | ||||
1121 | // Check if the hint starts with the loop metadata prefix. | |||
1122 | StringRef Name = S->getString(); | |||
1123 | if (Args.size() == 1) | |||
1124 | setHint(Name, Args[0]); | |||
1125 | } | |||
1126 | } | |||
1127 | ||||
1128 | /// Checks string hint with one operand and set value if valid. | |||
1129 | void setHint(StringRef Name, Value *Arg) { | |||
1130 | if (!Name.startswith(Prefix())) | |||
1131 | return; | |||
1132 | Name = Name.substr(Prefix().size(), StringRef::npos); | |||
1133 | ||||
1134 | const ConstantInt *C = dyn_cast<ConstantInt>(Arg); | |||
1135 | if (!C) return; | |||
1136 | unsigned Val = C->getZExtValue(); | |||
1137 | ||||
1138 | for (auto H : Hints) { | |||
1139 | if (Name == H->Name) { | |||
1140 | if (H->validate(Val)) | |||
1141 | H->Value = Val; | |||
1142 | else | |||
1143 | DEBUG(dbgs() << "LV: ignoring invalid hint '" << Name << "'\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: ignoring invalid hint '" << Name << "'\n"; } } while (0); | |||
1144 | break; | |||
1145 | } | |||
1146 | } | |||
1147 | } | |||
1148 | ||||
1149 | /// Create a new hint from name / value pair. | |||
1150 | MDNode *createHintMetadata(StringRef Name, unsigned V) const { | |||
1151 | LLVMContext &Context = TheLoop->getHeader()->getContext(); | |||
1152 | SmallVector<Value*, 2> Vals; | |||
1153 | Vals.push_back(MDString::get(Context, Name)); | |||
1154 | Vals.push_back(ConstantInt::get(Type::getInt32Ty(Context), V)); | |||
1155 | return MDNode::get(Context, Vals); | |||
1156 | } | |||
1157 | ||||
1158 | /// Matches metadata with hint name. | |||
1159 | bool matchesHintMetadataName(MDNode *Node, std::vector<Hint> &HintTypes) { | |||
1160 | MDString* Name = dyn_cast<MDString>(Node->getOperand(0)); | |||
1161 | if (!Name) | |||
1162 | return false; | |||
1163 | ||||
1164 | for (auto H : HintTypes) | |||
1165 | if (Name->getName().endswith(H.Name)) | |||
1166 | return true; | |||
1167 | return false; | |||
1168 | } | |||
1169 | ||||
1170 | /// Sets current hints into loop metadata, keeping other values intact. | |||
1171 | void writeHintsToMetadata(std::vector<Hint> HintTypes) { | |||
1172 | if (HintTypes.size() == 0) | |||
1173 | return; | |||
1174 | ||||
1175 | // Reserve the first element to LoopID (see below). | |||
1176 | SmallVector<Value*, 4> Vals(1); | |||
1177 | // If the loop already has metadata, then ignore the existing operands. | |||
1178 | MDNode *LoopID = TheLoop->getLoopID(); | |||
1179 | if (LoopID) { | |||
1180 | for (unsigned i = 1, ie = LoopID->getNumOperands(); i < ie; ++i) { | |||
1181 | MDNode *Node = cast<MDNode>(LoopID->getOperand(i)); | |||
1182 | // If node in update list, ignore old value. | |||
1183 | if (!matchesHintMetadataName(Node, HintTypes)) | |||
1184 | Vals.push_back(Node); | |||
1185 | } | |||
1186 | } | |||
1187 | ||||
1188 | // Now, add the missing hints. | |||
1189 | for (auto H : HintTypes) | |||
1190 | Vals.push_back( | |||
1191 | createHintMetadata(Twine(Prefix(), H.Name).str(), H.Value)); | |||
1192 | ||||
1193 | // Replace current metadata node with new one. | |||
1194 | LLVMContext &Context = TheLoop->getHeader()->getContext(); | |||
1195 | MDNode *NewLoopID = MDNode::get(Context, Vals); | |||
1196 | // Set operand 0 to refer to the loop id itself. | |||
1197 | NewLoopID->replaceOperandWith(0, NewLoopID); | |||
1198 | ||||
1199 | TheLoop->setLoopID(NewLoopID); | |||
1200 | if (LoopID) | |||
1201 | LoopID->replaceAllUsesWith(NewLoopID); | |||
1202 | LoopID = NewLoopID; | |||
1203 | } | |||
1204 | ||||
1205 | /// The loop these hints belong to. | |||
1206 | const Loop *TheLoop; | |||
1207 | }; | |||
1208 | ||||
1209 | static void emitMissedWarning(Function *F, Loop *L, | |||
1210 | const LoopVectorizeHints &LH) { | |||
1211 | emitOptimizationRemarkMissed(F->getContext(), DEBUG_TYPE"loop-vectorize", *F, | |||
1212 | L->getStartLoc(), LH.emitRemark()); | |||
1213 | ||||
1214 | if (LH.getForce() == LoopVectorizeHints::FK_Enabled) { | |||
1215 | if (LH.getWidth() != 1) | |||
1216 | emitLoopVectorizeWarning( | |||
1217 | F->getContext(), *F, L->getStartLoc(), | |||
1218 | "failed explicitly specified loop vectorization"); | |||
1219 | else if (LH.getInterleave() != 1) | |||
1220 | emitLoopInterleaveWarning( | |||
1221 | F->getContext(), *F, L->getStartLoc(), | |||
1222 | "failed explicitly specified loop interleaving"); | |||
1223 | } | |||
1224 | } | |||
1225 | ||||
1226 | static void addInnerLoop(Loop &L, SmallVectorImpl<Loop *> &V) { | |||
1227 | if (L.empty()) | |||
1228 | return V.push_back(&L); | |||
1229 | ||||
1230 | for (Loop *InnerL : L) | |||
1231 | addInnerLoop(*InnerL, V); | |||
1232 | } | |||
1233 | ||||
1234 | /// The LoopVectorize Pass. | |||
1235 | struct LoopVectorize : public FunctionPass { | |||
1236 | /// Pass identification, replacement for typeid | |||
1237 | static char ID; | |||
1238 | ||||
1239 | explicit LoopVectorize(bool NoUnrolling = false, bool AlwaysVectorize = true) | |||
1240 | : FunctionPass(ID), | |||
1241 | DisableUnrolling(NoUnrolling), | |||
1242 | AlwaysVectorize(AlwaysVectorize) { | |||
1243 | initializeLoopVectorizePass(*PassRegistry::getPassRegistry()); | |||
1244 | } | |||
1245 | ||||
1246 | ScalarEvolution *SE; | |||
1247 | const DataLayout *DL; | |||
1248 | LoopInfo *LI; | |||
1249 | TargetTransformInfo *TTI; | |||
1250 | DominatorTree *DT; | |||
1251 | BlockFrequencyInfo *BFI; | |||
1252 | TargetLibraryInfo *TLI; | |||
1253 | AliasAnalysis *AA; | |||
1254 | bool DisableUnrolling; | |||
1255 | bool AlwaysVectorize; | |||
1256 | ||||
1257 | BlockFrequency ColdEntryFreq; | |||
1258 | ||||
1259 | bool runOnFunction(Function &F) override { | |||
1260 | SE = &getAnalysis<ScalarEvolution>(); | |||
1261 | DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>(); | |||
1262 | DL = DLP ? &DLP->getDataLayout() : nullptr; | |||
1263 | LI = &getAnalysis<LoopInfo>(); | |||
1264 | TTI = &getAnalysis<TargetTransformInfo>(); | |||
1265 | DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree(); | |||
1266 | BFI = &getAnalysis<BlockFrequencyInfo>(); | |||
1267 | TLI = getAnalysisIfAvailable<TargetLibraryInfo>(); | |||
1268 | AA = &getAnalysis<AliasAnalysis>(); | |||
1269 | ||||
1270 | // Compute some weights outside of the loop over the loops. Compute this | |||
1271 | // using a BranchProbability to re-use its scaling math. | |||
1272 | const BranchProbability ColdProb(1, 5); // 20% | |||
1273 | ColdEntryFreq = BlockFrequency(BFI->getEntryFreq()) * ColdProb; | |||
1274 | ||||
1275 | // If the target claims to have no vector registers don't attempt | |||
1276 | // vectorization. | |||
1277 | if (!TTI->getNumberOfRegisters(true)) | |||
1278 | return false; | |||
1279 | ||||
1280 | if (!DL) { | |||
1281 | DEBUG(dbgs() << "\nLV: Not vectorizing " << F.getName()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "\nLV: Not vectorizing " << F.getName() << ": Missing data layout\n"; } } while (0) | |||
1282 | << ": Missing data layout\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "\nLV: Not vectorizing " << F.getName() << ": Missing data layout\n"; } } while (0); | |||
1283 | return false; | |||
1284 | } | |||
1285 | ||||
1286 | // Build up a worklist of inner-loops to vectorize. This is necessary as | |||
1287 | // the act of vectorizing or partially unrolling a loop creates new loops | |||
1288 | // and can invalidate iterators across the loops. | |||
1289 | SmallVector<Loop *, 8> Worklist; | |||
1290 | ||||
1291 | for (Loop *L : *LI) | |||
1292 | addInnerLoop(*L, Worklist); | |||
1293 | ||||
1294 | LoopsAnalyzed += Worklist.size(); | |||
1295 | ||||
1296 | // Now walk the identified inner loops. | |||
1297 | bool Changed = false; | |||
1298 | while (!Worklist.empty()) | |||
1299 | Changed |= processLoop(Worklist.pop_back_val()); | |||
1300 | ||||
1301 | // Process each loop nest in the function. | |||
1302 | return Changed; | |||
1303 | } | |||
1304 | ||||
1305 | bool processLoop(Loop *L) { | |||
1306 | assert(L->empty() && "Only process inner loops.")((L->empty() && "Only process inner loops.") ? static_cast <void> (0) : __assert_fail ("L->empty() && \"Only process inner loops.\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1306, __PRETTY_FUNCTION__)); | |||
1307 | ||||
1308 | #ifndef NDEBUG | |||
1309 | const std::string DebugLocStr = getDebugLocString(L); | |||
1310 | #endif /* NDEBUG */ | |||
1311 | ||||
1312 | DEBUG(dbgs() << "\nLV: Checking a loop in \""do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "\nLV: Checking a loop in \"" << L->getHeader()->getParent()->getName() << "\" from " << DebugLocStr << "\n"; } } while (0) | |||
1313 | << L->getHeader()->getParent()->getName() << "\" from "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "\nLV: Checking a loop in \"" << L->getHeader()->getParent()->getName() << "\" from " << DebugLocStr << "\n"; } } while (0) | |||
1314 | << DebugLocStr << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "\nLV: Checking a loop in \"" << L->getHeader()->getParent()->getName() << "\" from " << DebugLocStr << "\n"; } } while (0); | |||
1315 | ||||
1316 | LoopVectorizeHints Hints(L, DisableUnrolling); | |||
1317 | ||||
1318 | DEBUG(dbgs() << "LV: Loop hints:"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Loop hints:" << " force=" << (Hints.getForce() == LoopVectorizeHints:: FK_Disabled ? "disabled" : (Hints.getForce() == LoopVectorizeHints ::FK_Enabled ? "enabled" : "?")) << " width=" << Hints .getWidth() << " unroll=" << Hints.getInterleave( ) << "\n"; } } while (0) | |||
1319 | << " force="do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Loop hints:" << " force=" << (Hints.getForce() == LoopVectorizeHints:: FK_Disabled ? "disabled" : (Hints.getForce() == LoopVectorizeHints ::FK_Enabled ? "enabled" : "?")) << " width=" << Hints .getWidth() << " unroll=" << Hints.getInterleave( ) << "\n"; } } while (0) | |||
1320 | << (Hints.getForce() == LoopVectorizeHints::FK_Disableddo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Loop hints:" << " force=" << (Hints.getForce() == LoopVectorizeHints:: FK_Disabled ? "disabled" : (Hints.getForce() == LoopVectorizeHints ::FK_Enabled ? "enabled" : "?")) << " width=" << Hints .getWidth() << " unroll=" << Hints.getInterleave( ) << "\n"; } } while (0) | |||
1321 | ? "disabled"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Loop hints:" << " force=" << (Hints.getForce() == LoopVectorizeHints:: FK_Disabled ? "disabled" : (Hints.getForce() == LoopVectorizeHints ::FK_Enabled ? "enabled" : "?")) << " width=" << Hints .getWidth() << " unroll=" << Hints.getInterleave( ) << "\n"; } } while (0) | |||
1322 | : (Hints.getForce() == LoopVectorizeHints::FK_Enableddo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Loop hints:" << " force=" << (Hints.getForce() == LoopVectorizeHints:: FK_Disabled ? "disabled" : (Hints.getForce() == LoopVectorizeHints ::FK_Enabled ? "enabled" : "?")) << " width=" << Hints .getWidth() << " unroll=" << Hints.getInterleave( ) << "\n"; } } while (0) | |||
1323 | ? "enabled"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Loop hints:" << " force=" << (Hints.getForce() == LoopVectorizeHints:: FK_Disabled ? "disabled" : (Hints.getForce() == LoopVectorizeHints ::FK_Enabled ? "enabled" : "?")) << " width=" << Hints .getWidth() << " unroll=" << Hints.getInterleave( ) << "\n"; } } while (0) | |||
1324 | : "?")) << " width=" << Hints.getWidth()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Loop hints:" << " force=" << (Hints.getForce() == LoopVectorizeHints:: FK_Disabled ? "disabled" : (Hints.getForce() == LoopVectorizeHints ::FK_Enabled ? "enabled" : "?")) << " width=" << Hints .getWidth() << " unroll=" << Hints.getInterleave( ) << "\n"; } } while (0) | |||
1325 | << " unroll=" << Hints.getInterleave() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Loop hints:" << " force=" << (Hints.getForce() == LoopVectorizeHints:: FK_Disabled ? "disabled" : (Hints.getForce() == LoopVectorizeHints ::FK_Enabled ? "enabled" : "?")) << " width=" << Hints .getWidth() << " unroll=" << Hints.getInterleave( ) << "\n"; } } while (0); | |||
1326 | ||||
1327 | // Function containing loop | |||
1328 | Function *F = L->getHeader()->getParent(); | |||
1329 | ||||
1330 | // Looking at the diagnostic output is the only way to determine if a loop | |||
1331 | // was vectorized (other than looking at the IR or machine code), so it | |||
1332 | // is important to generate an optimization remark for each loop. Most of | |||
1333 | // these messages are generated by emitOptimizationRemarkAnalysis. Remarks | |||
1334 | // generated by emitOptimizationRemark and emitOptimizationRemarkMissed are | |||
1335 | // less verbose reporting vectorized loops and unvectorized loops that may | |||
1336 | // benefit from vectorization, respectively. | |||
1337 | ||||
1338 | if (Hints.getForce() == LoopVectorizeHints::FK_Disabled) { | |||
1339 | DEBUG(dbgs() << "LV: Not vectorizing: #pragma vectorize disable.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Not vectorizing: #pragma vectorize disable.\n" ; } } while (0); | |||
1340 | emitOptimizationRemarkAnalysis(F->getContext(), DEBUG_TYPE"loop-vectorize", *F, | |||
1341 | L->getStartLoc(), Hints.emitRemark()); | |||
1342 | return false; | |||
1343 | } | |||
1344 | ||||
1345 | if (!AlwaysVectorize && Hints.getForce() != LoopVectorizeHints::FK_Enabled) { | |||
1346 | DEBUG(dbgs() << "LV: Not vectorizing: No #pragma vectorize enable.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Not vectorizing: No #pragma vectorize enable.\n" ; } } while (0); | |||
1347 | emitOptimizationRemarkAnalysis(F->getContext(), DEBUG_TYPE"loop-vectorize", *F, | |||
1348 | L->getStartLoc(), Hints.emitRemark()); | |||
1349 | return false; | |||
1350 | } | |||
1351 | ||||
1352 | if (Hints.getWidth() == 1 && Hints.getInterleave() == 1) { | |||
1353 | DEBUG(dbgs() << "LV: Not vectorizing: Disabled/already vectorized.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Not vectorizing: Disabled/already vectorized.\n" ; } } while (0); | |||
1354 | emitOptimizationRemarkAnalysis( | |||
1355 | F->getContext(), DEBUG_TYPE"loop-vectorize", *F, L->getStartLoc(), | |||
1356 | "loop not vectorized: vector width and interleave count are " | |||
1357 | "explicitly set to 1"); | |||
1358 | return false; | |||
1359 | } | |||
1360 | ||||
1361 | // Check the loop for a trip count threshold: | |||
1362 | // do not vectorize loops with a tiny trip count. | |||
1363 | BasicBlock *Latch = L->getLoopLatch(); | |||
1364 | const unsigned TC = SE->getSmallConstantTripCount(L, Latch); | |||
1365 | if (TC > 0u && TC < TinyTripCountVectorThreshold) { | |||
1366 | DEBUG(dbgs() << "LV: Found a loop with a very small trip count. "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found a loop with a very small trip count. " << "This loop is not worth vectorizing."; } } while (0 ) | |||
1367 | << "This loop is not worth vectorizing.")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found a loop with a very small trip count. " << "This loop is not worth vectorizing."; } } while (0 ); | |||
1368 | if (Hints.getForce() == LoopVectorizeHints::FK_Enabled) | |||
1369 | DEBUG(dbgs() << " But vectorizing was explicitly forced.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << " But vectorizing was explicitly forced.\n" ; } } while (0); | |||
1370 | else { | |||
1371 | DEBUG(dbgs() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "\n"; } } while (0); | |||
1372 | emitOptimizationRemarkAnalysis( | |||
1373 | F->getContext(), DEBUG_TYPE"loop-vectorize", *F, L->getStartLoc(), | |||
1374 | "vectorization is not beneficial and is not explicitly forced"); | |||
1375 | return false; | |||
1376 | } | |||
1377 | } | |||
1378 | ||||
1379 | // Check if it is legal to vectorize the loop. | |||
1380 | LoopVectorizationLegality LVL(L, SE, DL, DT, TLI, AA, F); | |||
1381 | if (!LVL.canVectorize()) { | |||
1382 | DEBUG(dbgs() << "LV: Not vectorizing: Cannot prove legality.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Not vectorizing: Cannot prove legality.\n" ; } } while (0); | |||
1383 | emitMissedWarning(F, L, Hints); | |||
1384 | return false; | |||
1385 | } | |||
1386 | ||||
1387 | // Use the cost model. | |||
1388 | LoopVectorizationCostModel CM(L, SE, LI, &LVL, *TTI, DL, TLI, F, &Hints); | |||
1389 | ||||
1390 | // Check the function attributes to find out if this function should be | |||
1391 | // optimized for size. | |||
1392 | bool OptForSize = Hints.getForce() != LoopVectorizeHints::FK_Enabled && | |||
1393 | F->hasFnAttribute(Attribute::OptimizeForSize); | |||
1394 | ||||
1395 | // Compute the weighted frequency of this loop being executed and see if it | |||
1396 | // is less than 20% of the function entry baseline frequency. Note that we | |||
1397 | // always have a canonical loop here because we think we *can* vectoriez. | |||
1398 | // FIXME: This is hidden behind a flag due to pervasive problems with | |||
1399 | // exactly what block frequency models. | |||
1400 | if (LoopVectorizeWithBlockFrequency) { | |||
1401 | BlockFrequency LoopEntryFreq = BFI->getBlockFreq(L->getLoopPreheader()); | |||
1402 | if (Hints.getForce() != LoopVectorizeHints::FK_Enabled && | |||
1403 | LoopEntryFreq < ColdEntryFreq) | |||
1404 | OptForSize = true; | |||
1405 | } | |||
1406 | ||||
1407 | // Check the function attributes to see if implicit floats are allowed.a | |||
1408 | // FIXME: This check doesn't seem possibly correct -- what if the loop is | |||
1409 | // an integer loop and the vector instructions selected are purely integer | |||
1410 | // vector instructions? | |||
1411 | if (F->hasFnAttribute(Attribute::NoImplicitFloat)) { | |||
1412 | DEBUG(dbgs() << "LV: Can't vectorize when the NoImplicitFloat"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Can't vectorize when the NoImplicitFloat" "attribute is used.\n"; } } while (0) | |||
1413 | "attribute is used.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Can't vectorize when the NoImplicitFloat" "attribute is used.\n"; } } while (0); | |||
1414 | emitOptimizationRemarkAnalysis( | |||
1415 | F->getContext(), DEBUG_TYPE"loop-vectorize", *F, L->getStartLoc(), | |||
1416 | "loop not vectorized due to NoImplicitFloat attribute"); | |||
1417 | emitMissedWarning(F, L, Hints); | |||
1418 | return false; | |||
1419 | } | |||
1420 | ||||
1421 | // Select the optimal vectorization factor. | |||
1422 | const LoopVectorizationCostModel::VectorizationFactor VF = | |||
1423 | CM.selectVectorizationFactor(OptForSize); | |||
1424 | ||||
1425 | // Select the unroll factor. | |||
1426 | const unsigned UF = | |||
1427 | CM.selectUnrollFactor(OptForSize, VF.Width, VF.Cost); | |||
1428 | ||||
1429 | DEBUG(dbgs() << "LV: Found a vectorizable loop (" << VF.Width << ") in "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found a vectorizable loop (" << VF.Width << ") in " << DebugLocStr << '\n'; } } while (0) | |||
1430 | << DebugLocStr << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found a vectorizable loop (" << VF.Width << ") in " << DebugLocStr << '\n'; } } while (0); | |||
1431 | DEBUG(dbgs() << "LV: Unroll Factor is " << UF << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Unroll Factor is " << UF << '\n'; } } while (0); | |||
1432 | ||||
1433 | if (VF.Width == 1) { | |||
1434 | DEBUG(dbgs() << "LV: Vectorization is possible but not beneficial\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Vectorization is possible but not beneficial\n" ; } } while (0); | |||
1435 | ||||
1436 | if (UF == 1) { | |||
1437 | emitOptimizationRemarkAnalysis( | |||
1438 | F->getContext(), DEBUG_TYPE"loop-vectorize", *F, L->getStartLoc(), | |||
1439 | "not beneficial to vectorize and user disabled interleaving"); | |||
1440 | return false; | |||
1441 | } | |||
1442 | DEBUG(dbgs() << "LV: Trying to at least unroll the loops.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Trying to at least unroll the loops.\n" ; } } while (0); | |||
1443 | ||||
1444 | // Report the unrolling decision. | |||
1445 | emitOptimizationRemark(F->getContext(), DEBUG_TYPE"loop-vectorize", *F, L->getStartLoc(), | |||
1446 | Twine("unrolled with interleaving factor " + | |||
1447 | Twine(UF) + | |||
1448 | " (vectorization not beneficial)")); | |||
1449 | ||||
1450 | // We decided not to vectorize, but we may want to unroll. | |||
1451 | ||||
1452 | InnerLoopUnroller Unroller(L, SE, LI, DT, DL, TLI, UF); | |||
1453 | Unroller.vectorize(&LVL); | |||
1454 | } else { | |||
1455 | // If we decided that it is *legal* to vectorize the loop then do it. | |||
1456 | InnerLoopVectorizer LB(L, SE, LI, DT, DL, TLI, VF.Width, UF); | |||
1457 | LB.vectorize(&LVL); | |||
1458 | ++LoopsVectorized; | |||
1459 | ||||
1460 | // Report the vectorization decision. | |||
1461 | emitOptimizationRemark( | |||
1462 | F->getContext(), DEBUG_TYPE"loop-vectorize", *F, L->getStartLoc(), | |||
1463 | Twine("vectorized loop (vectorization factor: ") + Twine(VF.Width) + | |||
1464 | ", unrolling interleave factor: " + Twine(UF) + ")"); | |||
1465 | } | |||
1466 | ||||
1467 | // Mark the loop as already vectorized to avoid vectorizing again. | |||
1468 | Hints.setAlreadyVectorized(); | |||
1469 | ||||
1470 | DEBUG(verifyFunction(*L->getHeader()->getParent()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { verifyFunction(*L->getHeader()->getParent ()); } } while (0); | |||
1471 | return true; | |||
1472 | } | |||
1473 | ||||
1474 | void getAnalysisUsage(AnalysisUsage &AU) const override { | |||
1475 | AU.addRequiredID(LoopSimplifyID); | |||
1476 | AU.addRequiredID(LCSSAID); | |||
1477 | AU.addRequired<BlockFrequencyInfo>(); | |||
1478 | AU.addRequired<DominatorTreeWrapperPass>(); | |||
1479 | AU.addRequired<LoopInfo>(); | |||
1480 | AU.addRequired<ScalarEvolution>(); | |||
1481 | AU.addRequired<TargetTransformInfo>(); | |||
1482 | AU.addRequired<AliasAnalysis>(); | |||
1483 | AU.addPreserved<LoopInfo>(); | |||
1484 | AU.addPreserved<DominatorTreeWrapperPass>(); | |||
1485 | AU.addPreserved<AliasAnalysis>(); | |||
1486 | } | |||
1487 | ||||
1488 | }; | |||
1489 | ||||
1490 | } // end anonymous namespace | |||
1491 | ||||
1492 | //===----------------------------------------------------------------------===// | |||
1493 | // Implementation of LoopVectorizationLegality, InnerLoopVectorizer and | |||
1494 | // LoopVectorizationCostModel. | |||
1495 | //===----------------------------------------------------------------------===// | |||
1496 | ||||
1497 | static Value *stripIntegerCast(Value *V) { | |||
1498 | if (CastInst *CI = dyn_cast<CastInst>(V)) | |||
1499 | if (CI->getOperand(0)->getType()->isIntegerTy()) | |||
1500 | return CI->getOperand(0); | |||
1501 | return V; | |||
1502 | } | |||
1503 | ||||
1504 | ///\brief Replaces the symbolic stride in a pointer SCEV expression by one. | |||
1505 | /// | |||
1506 | /// If \p OrigPtr is not null, use it to look up the stride value instead of | |||
1507 | /// \p Ptr. | |||
1508 | static const SCEV *replaceSymbolicStrideSCEV(ScalarEvolution *SE, | |||
1509 | ValueToValueMap &PtrToStride, | |||
1510 | Value *Ptr, Value *OrigPtr = nullptr) { | |||
1511 | ||||
1512 | const SCEV *OrigSCEV = SE->getSCEV(Ptr); | |||
1513 | ||||
1514 | // If there is an entry in the map return the SCEV of the pointer with the | |||
1515 | // symbolic stride replaced by one. | |||
1516 | ValueToValueMap::iterator SI = PtrToStride.find(OrigPtr ? OrigPtr : Ptr); | |||
1517 | if (SI != PtrToStride.end()) { | |||
1518 | Value *StrideVal = SI->second; | |||
1519 | ||||
1520 | // Strip casts. | |||
1521 | StrideVal = stripIntegerCast(StrideVal); | |||
1522 | ||||
1523 | // Replace symbolic stride by one. | |||
1524 | Value *One = ConstantInt::get(StrideVal->getType(), 1); | |||
1525 | ValueToValueMap RewriteMap; | |||
1526 | RewriteMap[StrideVal] = One; | |||
1527 | ||||
1528 | const SCEV *ByOne = | |||
1529 | SCEVParameterRewriter::rewrite(OrigSCEV, *SE, RewriteMap, true); | |||
1530 | DEBUG(dbgs() << "LV: Replacing SCEV: " << *OrigSCEV << " by: " << *ByOnedo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Replacing SCEV: " << *OrigSCEV << " by: " << *ByOne << "\n"; } } while (0) | |||
1531 | << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Replacing SCEV: " << *OrigSCEV << " by: " << *ByOne << "\n"; } } while (0); | |||
1532 | return ByOne; | |||
1533 | } | |||
1534 | ||||
1535 | // Otherwise, just return the SCEV of the original pointer. | |||
1536 | return SE->getSCEV(Ptr); | |||
1537 | } | |||
1538 | ||||
1539 | void LoopVectorizationLegality::RuntimePointerCheck::insert( | |||
1540 | ScalarEvolution *SE, Loop *Lp, Value *Ptr, bool WritePtr, unsigned DepSetId, | |||
1541 | unsigned ASId, ValueToValueMap &Strides) { | |||
1542 | // Get the stride replaced scev. | |||
1543 | const SCEV *Sc = replaceSymbolicStrideSCEV(SE, Strides, Ptr); | |||
1544 | const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(Sc); | |||
1545 | assert(AR && "Invalid addrec expression")((AR && "Invalid addrec expression") ? static_cast< void> (0) : __assert_fail ("AR && \"Invalid addrec expression\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1545, __PRETTY_FUNCTION__)); | |||
1546 | const SCEV *Ex = SE->getBackedgeTakenCount(Lp); | |||
1547 | const SCEV *ScEnd = AR->evaluateAtIteration(Ex, *SE); | |||
1548 | Pointers.push_back(Ptr); | |||
1549 | Starts.push_back(AR->getStart()); | |||
1550 | Ends.push_back(ScEnd); | |||
1551 | IsWritePtr.push_back(WritePtr); | |||
1552 | DependencySetId.push_back(DepSetId); | |||
1553 | AliasSetId.push_back(ASId); | |||
1554 | } | |||
1555 | ||||
1556 | Value *InnerLoopVectorizer::getBroadcastInstrs(Value *V) { | |||
1557 | // We need to place the broadcast of invariant variables outside the loop. | |||
1558 | Instruction *Instr = dyn_cast<Instruction>(V); | |||
1559 | bool NewInstr = | |||
1560 | (Instr && std::find(LoopVectorBody.begin(), LoopVectorBody.end(), | |||
1561 | Instr->getParent()) != LoopVectorBody.end()); | |||
1562 | bool Invariant = OrigLoop->isLoopInvariant(V) && !NewInstr; | |||
1563 | ||||
1564 | // Place the code for broadcasting invariant variables in the new preheader. | |||
1565 | IRBuilder<>::InsertPointGuard Guard(Builder); | |||
1566 | if (Invariant) | |||
1567 | Builder.SetInsertPoint(LoopVectorPreHeader->getTerminator()); | |||
1568 | ||||
1569 | // Broadcast the scalar into all locations in the vector. | |||
1570 | Value *Shuf = Builder.CreateVectorSplat(VF, V, "broadcast"); | |||
1571 | ||||
1572 | return Shuf; | |||
1573 | } | |||
1574 | ||||
1575 | Value *InnerLoopVectorizer::getConsecutiveVector(Value* Val, int StartIdx, | |||
1576 | bool Negate) { | |||
1577 | assert(Val->getType()->isVectorTy() && "Must be a vector")((Val->getType()->isVectorTy() && "Must be a vector" ) ? static_cast<void> (0) : __assert_fail ("Val->getType()->isVectorTy() && \"Must be a vector\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1577, __PRETTY_FUNCTION__)); | |||
1578 | assert(Val->getType()->getScalarType()->isIntegerTy() &&((Val->getType()->getScalarType()->isIntegerTy() && "Elem must be an integer") ? static_cast<void> (0) : __assert_fail ("Val->getType()->getScalarType()->isIntegerTy() && \"Elem must be an integer\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1579, __PRETTY_FUNCTION__)) | |||
1579 | "Elem must be an integer")((Val->getType()->getScalarType()->isIntegerTy() && "Elem must be an integer") ? static_cast<void> (0) : __assert_fail ("Val->getType()->getScalarType()->isIntegerTy() && \"Elem must be an integer\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1579, __PRETTY_FUNCTION__)); | |||
1580 | // Create the types. | |||
1581 | Type *ITy = Val->getType()->getScalarType(); | |||
1582 | VectorType *Ty = cast<VectorType>(Val->getType()); | |||
1583 | int VLen = Ty->getNumElements(); | |||
1584 | SmallVector<Constant*, 8> Indices; | |||
1585 | ||||
1586 | // Create a vector of consecutive numbers from zero to VF. | |||
1587 | for (int i = 0; i < VLen; ++i) { | |||
1588 | int64_t Idx = Negate ? (-i) : i; | |||
1589 | Indices.push_back(ConstantInt::get(ITy, StartIdx + Idx, Negate)); | |||
1590 | } | |||
1591 | ||||
1592 | // Add the consecutive indices to the vector value. | |||
1593 | Constant *Cv = ConstantVector::get(Indices); | |||
1594 | assert(Cv->getType() == Val->getType() && "Invalid consecutive vec")((Cv->getType() == Val->getType() && "Invalid consecutive vec" ) ? static_cast<void> (0) : __assert_fail ("Cv->getType() == Val->getType() && \"Invalid consecutive vec\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1594, __PRETTY_FUNCTION__)); | |||
1595 | return Builder.CreateAdd(Val, Cv, "induction"); | |||
1596 | } | |||
1597 | ||||
1598 | /// \brief Find the operand of the GEP that should be checked for consecutive | |||
1599 | /// stores. This ignores trailing indices that have no effect on the final | |||
1600 | /// pointer. | |||
1601 | static unsigned getGEPInductionOperand(const DataLayout *DL, | |||
1602 | const GetElementPtrInst *Gep) { | |||
1603 | unsigned LastOperand = Gep->getNumOperands() - 1; | |||
1604 | unsigned GEPAllocSize = DL->getTypeAllocSize( | |||
1605 | cast<PointerType>(Gep->getType()->getScalarType())->getElementType()); | |||
1606 | ||||
1607 | // Walk backwards and try to peel off zeros. | |||
1608 | while (LastOperand > 1 && match(Gep->getOperand(LastOperand), m_Zero())) { | |||
1609 | // Find the type we're currently indexing into. | |||
1610 | gep_type_iterator GEPTI = gep_type_begin(Gep); | |||
1611 | std::advance(GEPTI, LastOperand - 1); | |||
1612 | ||||
1613 | // If it's a type with the same allocation size as the result of the GEP we | |||
1614 | // can peel off the zero index. | |||
1615 | if (DL->getTypeAllocSize(*GEPTI) != GEPAllocSize) | |||
1616 | break; | |||
1617 | --LastOperand; | |||
1618 | } | |||
1619 | ||||
1620 | return LastOperand; | |||
1621 | } | |||
1622 | ||||
1623 | int LoopVectorizationLegality::isConsecutivePtr(Value *Ptr) { | |||
1624 | assert(Ptr->getType()->isPointerTy() && "Unexpected non-ptr")((Ptr->getType()->isPointerTy() && "Unexpected non-ptr" ) ? static_cast<void> (0) : __assert_fail ("Ptr->getType()->isPointerTy() && \"Unexpected non-ptr\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1624, __PRETTY_FUNCTION__)); | |||
1625 | // Make sure that the pointer does not point to structs. | |||
1626 | if (Ptr->getType()->getPointerElementType()->isAggregateType()) | |||
1627 | return 0; | |||
1628 | ||||
1629 | // If this value is a pointer induction variable we know it is consecutive. | |||
1630 | PHINode *Phi = dyn_cast_or_null<PHINode>(Ptr); | |||
1631 | if (Phi && Inductions.count(Phi)) { | |||
1632 | InductionInfo II = Inductions[Phi]; | |||
1633 | if (IK_PtrInduction == II.IK) | |||
1634 | return 1; | |||
1635 | else if (IK_ReversePtrInduction == II.IK) | |||
1636 | return -1; | |||
1637 | } | |||
1638 | ||||
1639 | GetElementPtrInst *Gep = dyn_cast_or_null<GetElementPtrInst>(Ptr); | |||
1640 | if (!Gep) | |||
1641 | return 0; | |||
1642 | ||||
1643 | unsigned NumOperands = Gep->getNumOperands(); | |||
1644 | Value *GpPtr = Gep->getPointerOperand(); | |||
1645 | // If this GEP value is a consecutive pointer induction variable and all of | |||
1646 | // the indices are constant then we know it is consecutive. We can | |||
1647 | Phi = dyn_cast<PHINode>(GpPtr); | |||
1648 | if (Phi && Inductions.count(Phi)) { | |||
1649 | ||||
1650 | // Make sure that the pointer does not point to structs. | |||
1651 | PointerType *GepPtrType = cast<PointerType>(GpPtr->getType()); | |||
1652 | if (GepPtrType->getElementType()->isAggregateType()) | |||
1653 | return 0; | |||
1654 | ||||
1655 | // Make sure that all of the index operands are loop invariant. | |||
1656 | for (unsigned i = 1; i < NumOperands; ++i) | |||
1657 | if (!SE->isLoopInvariant(SE->getSCEV(Gep->getOperand(i)), TheLoop)) | |||
1658 | return 0; | |||
1659 | ||||
1660 | InductionInfo II = Inductions[Phi]; | |||
1661 | if (IK_PtrInduction == II.IK) | |||
1662 | return 1; | |||
1663 | else if (IK_ReversePtrInduction == II.IK) | |||
1664 | return -1; | |||
1665 | } | |||
1666 | ||||
1667 | unsigned InductionOperand = getGEPInductionOperand(DL, Gep); | |||
1668 | ||||
1669 | // Check that all of the gep indices are uniform except for our induction | |||
1670 | // operand. | |||
1671 | for (unsigned i = 0; i != NumOperands; ++i) | |||
1672 | if (i != InductionOperand && | |||
1673 | !SE->isLoopInvariant(SE->getSCEV(Gep->getOperand(i)), TheLoop)) | |||
1674 | return 0; | |||
1675 | ||||
1676 | // We can emit wide load/stores only if the last non-zero index is the | |||
1677 | // induction variable. | |||
1678 | const SCEV *Last = nullptr; | |||
1679 | if (!Strides.count(Gep)) | |||
1680 | Last = SE->getSCEV(Gep->getOperand(InductionOperand)); | |||
1681 | else { | |||
1682 | // Because of the multiplication by a stride we can have a s/zext cast. | |||
1683 | // We are going to replace this stride by 1 so the cast is safe to ignore. | |||
1684 | // | |||
1685 | // %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ] | |||
1686 | // %0 = trunc i64 %indvars.iv to i32 | |||
1687 | // %mul = mul i32 %0, %Stride1 | |||
1688 | // %idxprom = zext i32 %mul to i64 << Safe cast. | |||
1689 | // %arrayidx = getelementptr inbounds i32* %B, i64 %idxprom | |||
1690 | // | |||
1691 | Last = replaceSymbolicStrideSCEV(SE, Strides, | |||
1692 | Gep->getOperand(InductionOperand), Gep); | |||
1693 | if (const SCEVCastExpr *C = dyn_cast<SCEVCastExpr>(Last)) | |||
1694 | Last = | |||
1695 | (C->getSCEVType() == scSignExtend || C->getSCEVType() == scZeroExtend) | |||
1696 | ? C->getOperand() | |||
1697 | : Last; | |||
1698 | } | |||
1699 | if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(Last)) { | |||
1700 | const SCEV *Step = AR->getStepRecurrence(*SE); | |||
1701 | ||||
1702 | // The memory is consecutive because the last index is consecutive | |||
1703 | // and all other indices are loop invariant. | |||
1704 | if (Step->isOne()) | |||
1705 | return 1; | |||
1706 | if (Step->isAllOnesValue()) | |||
1707 | return -1; | |||
1708 | } | |||
1709 | ||||
1710 | return 0; | |||
1711 | } | |||
1712 | ||||
1713 | bool LoopVectorizationLegality::isUniform(Value *V) { | |||
1714 | return (SE->isLoopInvariant(SE->getSCEV(V), TheLoop)); | |||
1715 | } | |||
1716 | ||||
1717 | InnerLoopVectorizer::VectorParts& | |||
1718 | InnerLoopVectorizer::getVectorValue(Value *V) { | |||
1719 | assert(V != Induction && "The new induction variable should not be used.")((V != Induction && "The new induction variable should not be used." ) ? static_cast<void> (0) : __assert_fail ("V != Induction && \"The new induction variable should not be used.\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1719, __PRETTY_FUNCTION__)); | |||
1720 | assert(!V->getType()->isVectorTy() && "Can't widen a vector")((!V->getType()->isVectorTy() && "Can't widen a vector" ) ? static_cast<void> (0) : __assert_fail ("!V->getType()->isVectorTy() && \"Can't widen a vector\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1720, __PRETTY_FUNCTION__)); | |||
1721 | ||||
1722 | // If we have a stride that is replaced by one, do it here. | |||
1723 | if (Legal->hasStride(V)) | |||
1724 | V = ConstantInt::get(V->getType(), 1); | |||
1725 | ||||
1726 | // If we have this scalar in the map, return it. | |||
1727 | if (WidenMap.has(V)) | |||
1728 | return WidenMap.get(V); | |||
1729 | ||||
1730 | // If this scalar is unknown, assume that it is a constant or that it is | |||
1731 | // loop invariant. Broadcast V and save the value for future uses. | |||
1732 | Value *B = getBroadcastInstrs(V); | |||
1733 | return WidenMap.splat(V, B); | |||
1734 | } | |||
1735 | ||||
1736 | Value *InnerLoopVectorizer::reverseVector(Value *Vec) { | |||
1737 | assert(Vec->getType()->isVectorTy() && "Invalid type")((Vec->getType()->isVectorTy() && "Invalid type" ) ? static_cast<void> (0) : __assert_fail ("Vec->getType()->isVectorTy() && \"Invalid type\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1737, __PRETTY_FUNCTION__)); | |||
1738 | SmallVector<Constant*, 8> ShuffleMask; | |||
1739 | for (unsigned i = 0; i < VF; ++i) | |||
1740 | ShuffleMask.push_back(Builder.getInt32(VF - i - 1)); | |||
1741 | ||||
1742 | return Builder.CreateShuffleVector(Vec, UndefValue::get(Vec->getType()), | |||
1743 | ConstantVector::get(ShuffleMask), | |||
1744 | "reverse"); | |||
1745 | } | |||
1746 | ||||
1747 | void InnerLoopVectorizer::vectorizeMemoryInstruction(Instruction *Instr) { | |||
1748 | // Attempt to issue a wide load. | |||
1749 | LoadInst *LI = dyn_cast<LoadInst>(Instr); | |||
1750 | StoreInst *SI = dyn_cast<StoreInst>(Instr); | |||
1751 | ||||
1752 | assert((LI || SI) && "Invalid Load/Store instruction")(((LI || SI) && "Invalid Load/Store instruction") ? static_cast <void> (0) : __assert_fail ("(LI || SI) && \"Invalid Load/Store instruction\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1752, __PRETTY_FUNCTION__)); | |||
1753 | ||||
1754 | Type *ScalarDataTy = LI ? LI->getType() : SI->getValueOperand()->getType(); | |||
1755 | Type *DataTy = VectorType::get(ScalarDataTy, VF); | |||
1756 | Value *Ptr = LI ? LI->getPointerOperand() : SI->getPointerOperand(); | |||
1757 | unsigned Alignment = LI ? LI->getAlignment() : SI->getAlignment(); | |||
1758 | // An alignment of 0 means target abi alignment. We need to use the scalar's | |||
1759 | // target abi alignment in such a case. | |||
1760 | if (!Alignment) | |||
1761 | Alignment = DL->getABITypeAlignment(ScalarDataTy); | |||
1762 | unsigned AddressSpace = Ptr->getType()->getPointerAddressSpace(); | |||
1763 | unsigned ScalarAllocatedSize = DL->getTypeAllocSize(ScalarDataTy); | |||
1764 | unsigned VectorElementSize = DL->getTypeStoreSize(DataTy)/VF; | |||
1765 | ||||
1766 | if (SI && Legal->blockNeedsPredication(SI->getParent())) | |||
1767 | return scalarizeInstruction(Instr, true); | |||
1768 | ||||
1769 | if (ScalarAllocatedSize != VectorElementSize) | |||
1770 | return scalarizeInstruction(Instr); | |||
1771 | ||||
1772 | // If the pointer is loop invariant or if it is non-consecutive, | |||
1773 | // scalarize the load. | |||
1774 | int ConsecutiveStride = Legal->isConsecutivePtr(Ptr); | |||
1775 | bool Reverse = ConsecutiveStride < 0; | |||
1776 | bool UniformLoad = LI && Legal->isUniform(Ptr); | |||
1777 | if (!ConsecutiveStride || UniformLoad) | |||
1778 | return scalarizeInstruction(Instr); | |||
1779 | ||||
1780 | Constant *Zero = Builder.getInt32(0); | |||
1781 | VectorParts &Entry = WidenMap.get(Instr); | |||
1782 | ||||
1783 | // Handle consecutive loads/stores. | |||
1784 | GetElementPtrInst *Gep = dyn_cast<GetElementPtrInst>(Ptr); | |||
1785 | if (Gep && Legal->isInductionVariable(Gep->getPointerOperand())) { | |||
1786 | setDebugLocFromInst(Builder, Gep); | |||
1787 | Value *PtrOperand = Gep->getPointerOperand(); | |||
1788 | Value *FirstBasePtr = getVectorValue(PtrOperand)[0]; | |||
1789 | FirstBasePtr = Builder.CreateExtractElement(FirstBasePtr, Zero); | |||
1790 | ||||
1791 | // Create the new GEP with the new induction variable. | |||
1792 | GetElementPtrInst *Gep2 = cast<GetElementPtrInst>(Gep->clone()); | |||
1793 | Gep2->setOperand(0, FirstBasePtr); | |||
1794 | Gep2->setName("gep.indvar.base"); | |||
1795 | Ptr = Builder.Insert(Gep2); | |||
1796 | } else if (Gep) { | |||
1797 | setDebugLocFromInst(Builder, Gep); | |||
1798 | assert(SE->isLoopInvariant(SE->getSCEV(Gep->getPointerOperand()),((SE->isLoopInvariant(SE->getSCEV(Gep->getPointerOperand ()), OrigLoop) && "Base ptr must be invariant") ? static_cast <void> (0) : __assert_fail ("SE->isLoopInvariant(SE->getSCEV(Gep->getPointerOperand()), OrigLoop) && \"Base ptr must be invariant\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1799, __PRETTY_FUNCTION__)) | |||
1799 | OrigLoop) && "Base ptr must be invariant")((SE->isLoopInvariant(SE->getSCEV(Gep->getPointerOperand ()), OrigLoop) && "Base ptr must be invariant") ? static_cast <void> (0) : __assert_fail ("SE->isLoopInvariant(SE->getSCEV(Gep->getPointerOperand()), OrigLoop) && \"Base ptr must be invariant\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1799, __PRETTY_FUNCTION__)); | |||
1800 | ||||
1801 | // The last index does not have to be the induction. It can be | |||
1802 | // consecutive and be a function of the index. For example A[I+1]; | |||
1803 | unsigned NumOperands = Gep->getNumOperands(); | |||
1804 | unsigned InductionOperand = getGEPInductionOperand(DL, Gep); | |||
1805 | // Create the new GEP with the new induction variable. | |||
1806 | GetElementPtrInst *Gep2 = cast<GetElementPtrInst>(Gep->clone()); | |||
1807 | ||||
1808 | for (unsigned i = 0; i < NumOperands; ++i) { | |||
1809 | Value *GepOperand = Gep->getOperand(i); | |||
1810 | Instruction *GepOperandInst = dyn_cast<Instruction>(GepOperand); | |||
1811 | ||||
1812 | // Update last index or loop invariant instruction anchored in loop. | |||
1813 | if (i == InductionOperand || | |||
1814 | (GepOperandInst && OrigLoop->contains(GepOperandInst))) { | |||
1815 | assert((i == InductionOperand ||(((i == InductionOperand || SE->isLoopInvariant(SE->getSCEV (GepOperandInst), OrigLoop)) && "Must be last index or loop invariant" ) ? static_cast<void> (0) : __assert_fail ("(i == InductionOperand || SE->isLoopInvariant(SE->getSCEV(GepOperandInst), OrigLoop)) && \"Must be last index or loop invariant\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1817, __PRETTY_FUNCTION__)) | |||
1816 | SE->isLoopInvariant(SE->getSCEV(GepOperandInst), OrigLoop)) &&(((i == InductionOperand || SE->isLoopInvariant(SE->getSCEV (GepOperandInst), OrigLoop)) && "Must be last index or loop invariant" ) ? static_cast<void> (0) : __assert_fail ("(i == InductionOperand || SE->isLoopInvariant(SE->getSCEV(GepOperandInst), OrigLoop)) && \"Must be last index or loop invariant\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1817, __PRETTY_FUNCTION__)) | |||
1817 | "Must be last index or loop invariant")(((i == InductionOperand || SE->isLoopInvariant(SE->getSCEV (GepOperandInst), OrigLoop)) && "Must be last index or loop invariant" ) ? static_cast<void> (0) : __assert_fail ("(i == InductionOperand || SE->isLoopInvariant(SE->getSCEV(GepOperandInst), OrigLoop)) && \"Must be last index or loop invariant\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1817, __PRETTY_FUNCTION__)); | |||
1818 | ||||
1819 | VectorParts &GEPParts = getVectorValue(GepOperand); | |||
1820 | Value *Index = GEPParts[0]; | |||
1821 | Index = Builder.CreateExtractElement(Index, Zero); | |||
1822 | Gep2->setOperand(i, Index); | |||
1823 | Gep2->setName("gep.indvar.idx"); | |||
1824 | } | |||
1825 | } | |||
1826 | Ptr = Builder.Insert(Gep2); | |||
1827 | } else { | |||
1828 | // Use the induction element ptr. | |||
1829 | assert(isa<PHINode>(Ptr) && "Invalid induction ptr")((isa<PHINode>(Ptr) && "Invalid induction ptr") ? static_cast<void> (0) : __assert_fail ("isa<PHINode>(Ptr) && \"Invalid induction ptr\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1829, __PRETTY_FUNCTION__)); | |||
1830 | setDebugLocFromInst(Builder, Ptr); | |||
1831 | VectorParts &PtrVal = getVectorValue(Ptr); | |||
1832 | Ptr = Builder.CreateExtractElement(PtrVal[0], Zero); | |||
1833 | } | |||
1834 | ||||
1835 | // Handle Stores: | |||
1836 | if (SI) { | |||
1837 | assert(!Legal->isUniform(SI->getPointerOperand()) &&((!Legal->isUniform(SI->getPointerOperand()) && "We do not allow storing to uniform addresses") ? static_cast <void> (0) : __assert_fail ("!Legal->isUniform(SI->getPointerOperand()) && \"We do not allow storing to uniform addresses\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1838, __PRETTY_FUNCTION__)) | |||
1838 | "We do not allow storing to uniform addresses")((!Legal->isUniform(SI->getPointerOperand()) && "We do not allow storing to uniform addresses") ? static_cast <void> (0) : __assert_fail ("!Legal->isUniform(SI->getPointerOperand()) && \"We do not allow storing to uniform addresses\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1838, __PRETTY_FUNCTION__)); | |||
1839 | setDebugLocFromInst(Builder, SI); | |||
1840 | // We don't want to update the value in the map as it might be used in | |||
1841 | // another expression. So don't use a reference type for "StoredVal". | |||
1842 | VectorParts StoredVal = getVectorValue(SI->getValueOperand()); | |||
1843 | ||||
1844 | for (unsigned Part = 0; Part < UF; ++Part) { | |||
1845 | // Calculate the pointer for the specific unroll-part. | |||
1846 | Value *PartPtr = Builder.CreateGEP(Ptr, Builder.getInt32(Part * VF)); | |||
1847 | ||||
1848 | if (Reverse) { | |||
1849 | // If we store to reverse consecutive memory locations then we need | |||
1850 | // to reverse the order of elements in the stored value. | |||
1851 | StoredVal[Part] = reverseVector(StoredVal[Part]); | |||
1852 | // If the address is consecutive but reversed, then the | |||
1853 | // wide store needs to start at the last vector element. | |||
1854 | PartPtr = Builder.CreateGEP(Ptr, Builder.getInt32(-Part * VF)); | |||
1855 | PartPtr = Builder.CreateGEP(PartPtr, Builder.getInt32(1 - VF)); | |||
1856 | } | |||
1857 | ||||
1858 | Value *VecPtr = Builder.CreateBitCast(PartPtr, | |||
1859 | DataTy->getPointerTo(AddressSpace)); | |||
1860 | StoreInst *NewSI = | |||
1861 | Builder.CreateAlignedStore(StoredVal[Part], VecPtr, Alignment); | |||
1862 | propagateMetadata(NewSI, SI); | |||
1863 | } | |||
1864 | return; | |||
1865 | } | |||
1866 | ||||
1867 | // Handle loads. | |||
1868 | assert(LI && "Must have a load instruction")((LI && "Must have a load instruction") ? static_cast <void> (0) : __assert_fail ("LI && \"Must have a load instruction\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1868, __PRETTY_FUNCTION__)); | |||
1869 | setDebugLocFromInst(Builder, LI); | |||
1870 | for (unsigned Part = 0; Part < UF; ++Part) { | |||
1871 | // Calculate the pointer for the specific unroll-part. | |||
1872 | Value *PartPtr = Builder.CreateGEP(Ptr, Builder.getInt32(Part * VF)); | |||
1873 | ||||
1874 | if (Reverse) { | |||
1875 | // If the address is consecutive but reversed, then the | |||
1876 | // wide store needs to start at the last vector element. | |||
1877 | PartPtr = Builder.CreateGEP(Ptr, Builder.getInt32(-Part * VF)); | |||
1878 | PartPtr = Builder.CreateGEP(PartPtr, Builder.getInt32(1 - VF)); | |||
1879 | } | |||
1880 | ||||
1881 | Value *VecPtr = Builder.CreateBitCast(PartPtr, | |||
1882 | DataTy->getPointerTo(AddressSpace)); | |||
1883 | LoadInst *NewLI = Builder.CreateAlignedLoad(VecPtr, Alignment, "wide.load"); | |||
1884 | propagateMetadata(NewLI, LI); | |||
1885 | Entry[Part] = Reverse ? reverseVector(NewLI) : NewLI; | |||
1886 | } | |||
1887 | } | |||
1888 | ||||
1889 | void InnerLoopVectorizer::scalarizeInstruction(Instruction *Instr, bool IfPredicateStore) { | |||
1890 | assert(!Instr->getType()->isAggregateType() && "Can't handle vectors")((!Instr->getType()->isAggregateType() && "Can't handle vectors" ) ? static_cast<void> (0) : __assert_fail ("!Instr->getType()->isAggregateType() && \"Can't handle vectors\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1890, __PRETTY_FUNCTION__)); | |||
1891 | // Holds vector parameters or scalars, in case of uniform vals. | |||
1892 | SmallVector<VectorParts, 4> Params; | |||
1893 | ||||
1894 | setDebugLocFromInst(Builder, Instr); | |||
1895 | ||||
1896 | // Find all of the vectorized parameters. | |||
1897 | for (unsigned op = 0, e = Instr->getNumOperands(); op != e; ++op) { | |||
1898 | Value *SrcOp = Instr->getOperand(op); | |||
1899 | ||||
1900 | // If we are accessing the old induction variable, use the new one. | |||
1901 | if (SrcOp == OldInduction) { | |||
1902 | Params.push_back(getVectorValue(SrcOp)); | |||
1903 | continue; | |||
1904 | } | |||
1905 | ||||
1906 | // Try using previously calculated values. | |||
1907 | Instruction *SrcInst = dyn_cast<Instruction>(SrcOp); | |||
1908 | ||||
1909 | // If the src is an instruction that appeared earlier in the basic block | |||
1910 | // then it should already be vectorized. | |||
1911 | if (SrcInst && OrigLoop->contains(SrcInst)) { | |||
1912 | assert(WidenMap.has(SrcInst) && "Source operand is unavailable")((WidenMap.has(SrcInst) && "Source operand is unavailable" ) ? static_cast<void> (0) : __assert_fail ("WidenMap.has(SrcInst) && \"Source operand is unavailable\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1912, __PRETTY_FUNCTION__)); | |||
1913 | // The parameter is a vector value from earlier. | |||
1914 | Params.push_back(WidenMap.get(SrcInst)); | |||
1915 | } else { | |||
1916 | // The parameter is a scalar from outside the loop. Maybe even a constant. | |||
1917 | VectorParts Scalars; | |||
1918 | Scalars.append(UF, SrcOp); | |||
1919 | Params.push_back(Scalars); | |||
1920 | } | |||
1921 | } | |||
1922 | ||||
1923 | assert(Params.size() == Instr->getNumOperands() &&((Params.size() == Instr->getNumOperands() && "Invalid number of operands" ) ? static_cast<void> (0) : __assert_fail ("Params.size() == Instr->getNumOperands() && \"Invalid number of operands\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1924, __PRETTY_FUNCTION__)) | |||
1924 | "Invalid number of operands")((Params.size() == Instr->getNumOperands() && "Invalid number of operands" ) ? static_cast<void> (0) : __assert_fail ("Params.size() == Instr->getNumOperands() && \"Invalid number of operands\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1924, __PRETTY_FUNCTION__)); | |||
1925 | ||||
1926 | // Does this instruction return a value ? | |||
1927 | bool IsVoidRetTy = Instr->getType()->isVoidTy(); | |||
1928 | ||||
1929 | Value *UndefVec = IsVoidRetTy ? nullptr : | |||
1930 | UndefValue::get(VectorType::get(Instr->getType(), VF)); | |||
1931 | // Create a new entry in the WidenMap and initialize it to Undef or Null. | |||
1932 | VectorParts &VecResults = WidenMap.splat(Instr, UndefVec); | |||
1933 | ||||
1934 | Instruction *InsertPt = Builder.GetInsertPoint(); | |||
1935 | BasicBlock *IfBlock = Builder.GetInsertBlock(); | |||
1936 | BasicBlock *CondBlock = nullptr; | |||
1937 | ||||
1938 | VectorParts Cond; | |||
1939 | Loop *VectorLp = nullptr; | |||
1940 | if (IfPredicateStore) { | |||
1941 | assert(Instr->getParent()->getSinglePredecessor() &&((Instr->getParent()->getSinglePredecessor() && "Only support single predecessor blocks") ? static_cast<void > (0) : __assert_fail ("Instr->getParent()->getSinglePredecessor() && \"Only support single predecessor blocks\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1942, __PRETTY_FUNCTION__)) | |||
1942 | "Only support single predecessor blocks")((Instr->getParent()->getSinglePredecessor() && "Only support single predecessor blocks") ? static_cast<void > (0) : __assert_fail ("Instr->getParent()->getSinglePredecessor() && \"Only support single predecessor blocks\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1942, __PRETTY_FUNCTION__)); | |||
1943 | Cond = createEdgeMask(Instr->getParent()->getSinglePredecessor(), | |||
1944 | Instr->getParent()); | |||
1945 | VectorLp = LI->getLoopFor(IfBlock); | |||
1946 | assert(VectorLp && "Must have a loop for this block")((VectorLp && "Must have a loop for this block") ? static_cast <void> (0) : __assert_fail ("VectorLp && \"Must have a loop for this block\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1946, __PRETTY_FUNCTION__)); | |||
1947 | } | |||
1948 | ||||
1949 | // For each vector unroll 'part': | |||
1950 | for (unsigned Part = 0; Part < UF; ++Part) { | |||
1951 | // For each scalar that we create: | |||
1952 | for (unsigned Width = 0; Width < VF; ++Width) { | |||
1953 | ||||
1954 | // Start if-block. | |||
1955 | Value *Cmp = nullptr; | |||
1956 | if (IfPredicateStore) { | |||
1957 | Cmp = Builder.CreateExtractElement(Cond[Part], Builder.getInt32(Width)); | |||
1958 | Cmp = Builder.CreateICmp(ICmpInst::ICMP_EQ, Cmp, ConstantInt::get(Cmp->getType(), 1)); | |||
1959 | CondBlock = IfBlock->splitBasicBlock(InsertPt, "cond.store"); | |||
1960 | LoopVectorBody.push_back(CondBlock); | |||
1961 | VectorLp->addBasicBlockToLoop(CondBlock, LI->getBase()); | |||
1962 | // Update Builder with newly created basic block. | |||
1963 | Builder.SetInsertPoint(InsertPt); | |||
1964 | } | |||
1965 | ||||
1966 | Instruction *Cloned = Instr->clone(); | |||
1967 | if (!IsVoidRetTy) | |||
1968 | Cloned->setName(Instr->getName() + ".cloned"); | |||
1969 | // Replace the operands of the cloned instructions with extracted scalars. | |||
1970 | for (unsigned op = 0, e = Instr->getNumOperands(); op != e; ++op) { | |||
1971 | Value *Op = Params[op][Part]; | |||
1972 | // Param is a vector. Need to extract the right lane. | |||
1973 | if (Op->getType()->isVectorTy()) | |||
1974 | Op = Builder.CreateExtractElement(Op, Builder.getInt32(Width)); | |||
1975 | Cloned->setOperand(op, Op); | |||
1976 | } | |||
1977 | ||||
1978 | // Place the cloned scalar in the new loop. | |||
1979 | Builder.Insert(Cloned); | |||
1980 | ||||
1981 | // If the original scalar returns a value we need to place it in a vector | |||
1982 | // so that future users will be able to use it. | |||
1983 | if (!IsVoidRetTy) | |||
1984 | VecResults[Part] = Builder.CreateInsertElement(VecResults[Part], Cloned, | |||
1985 | Builder.getInt32(Width)); | |||
1986 | // End if-block. | |||
1987 | if (IfPredicateStore) { | |||
1988 | BasicBlock *NewIfBlock = CondBlock->splitBasicBlock(InsertPt, "else"); | |||
1989 | LoopVectorBody.push_back(NewIfBlock); | |||
1990 | VectorLp->addBasicBlockToLoop(NewIfBlock, LI->getBase()); | |||
1991 | Builder.SetInsertPoint(InsertPt); | |||
1992 | Instruction *OldBr = IfBlock->getTerminator(); | |||
1993 | BranchInst::Create(CondBlock, NewIfBlock, Cmp, OldBr); | |||
1994 | OldBr->eraseFromParent(); | |||
1995 | IfBlock = NewIfBlock; | |||
1996 | } | |||
1997 | } | |||
1998 | } | |||
1999 | } | |||
2000 | ||||
2001 | static Instruction *getFirstInst(Instruction *FirstInst, Value *V, | |||
2002 | Instruction *Loc) { | |||
2003 | if (FirstInst) | |||
2004 | return FirstInst; | |||
2005 | if (Instruction *I = dyn_cast<Instruction>(V)) | |||
2006 | return I->getParent() == Loc->getParent() ? I : nullptr; | |||
2007 | return nullptr; | |||
2008 | } | |||
2009 | ||||
2010 | std::pair<Instruction *, Instruction *> | |||
2011 | InnerLoopVectorizer::addStrideCheck(Instruction *Loc) { | |||
2012 | Instruction *tnullptr = nullptr; | |||
2013 | if (!Legal->mustCheckStrides()) | |||
2014 | return std::pair<Instruction *, Instruction *>(tnullptr, tnullptr); | |||
2015 | ||||
2016 | IRBuilder<> ChkBuilder(Loc); | |||
2017 | ||||
2018 | // Emit checks. | |||
2019 | Value *Check = nullptr; | |||
2020 | Instruction *FirstInst = nullptr; | |||
2021 | for (SmallPtrSet<Value *, 8>::iterator SI = Legal->strides_begin(), | |||
2022 | SE = Legal->strides_end(); | |||
2023 | SI != SE; ++SI) { | |||
2024 | Value *Ptr = stripIntegerCast(*SI); | |||
2025 | Value *C = ChkBuilder.CreateICmpNE(Ptr, ConstantInt::get(Ptr->getType(), 1), | |||
2026 | "stride.chk"); | |||
2027 | // Store the first instruction we create. | |||
2028 | FirstInst = getFirstInst(FirstInst, C, Loc); | |||
2029 | if (Check) | |||
2030 | Check = ChkBuilder.CreateOr(Check, C); | |||
2031 | else | |||
2032 | Check = C; | |||
2033 | } | |||
2034 | ||||
2035 | // We have to do this trickery because the IRBuilder might fold the check to a | |||
2036 | // constant expression in which case there is no Instruction anchored in a | |||
2037 | // the block. | |||
2038 | LLVMContext &Ctx = Loc->getContext(); | |||
2039 | Instruction *TheCheck = | |||
2040 | BinaryOperator::CreateAnd(Check, ConstantInt::getTrue(Ctx)); | |||
2041 | ChkBuilder.Insert(TheCheck, "stride.not.one"); | |||
2042 | FirstInst = getFirstInst(FirstInst, TheCheck, Loc); | |||
2043 | ||||
2044 | return std::make_pair(FirstInst, TheCheck); | |||
2045 | } | |||
2046 | ||||
2047 | std::pair<Instruction *, Instruction *> | |||
2048 | InnerLoopVectorizer::addRuntimeCheck(Instruction *Loc) { | |||
2049 | LoopVectorizationLegality::RuntimePointerCheck *PtrRtCheck = | |||
2050 | Legal->getRuntimePointerCheck(); | |||
2051 | ||||
2052 | Instruction *tnullptr = nullptr; | |||
2053 | if (!PtrRtCheck->Need) | |||
2054 | return std::pair<Instruction *, Instruction *>(tnullptr, tnullptr); | |||
2055 | ||||
2056 | unsigned NumPointers = PtrRtCheck->Pointers.size(); | |||
2057 | SmallVector<TrackingVH<Value> , 2> Starts; | |||
2058 | SmallVector<TrackingVH<Value> , 2> Ends; | |||
2059 | ||||
2060 | LLVMContext &Ctx = Loc->getContext(); | |||
2061 | SCEVExpander Exp(*SE, "induction"); | |||
2062 | Instruction *FirstInst = nullptr; | |||
2063 | ||||
2064 | for (unsigned i = 0; i < NumPointers; ++i) { | |||
2065 | Value *Ptr = PtrRtCheck->Pointers[i]; | |||
2066 | const SCEV *Sc = SE->getSCEV(Ptr); | |||
2067 | ||||
2068 | if (SE->isLoopInvariant(Sc, OrigLoop)) { | |||
2069 | DEBUG(dbgs() << "LV: Adding RT check for a loop invariant ptr:" <<do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Adding RT check for a loop invariant ptr:" << *Ptr <<"\n"; } } while (0) | |||
2070 | *Ptr <<"\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Adding RT check for a loop invariant ptr:" << *Ptr <<"\n"; } } while (0); | |||
2071 | Starts.push_back(Ptr); | |||
2072 | Ends.push_back(Ptr); | |||
2073 | } else { | |||
2074 | DEBUG(dbgs() << "LV: Adding RT check for range:" << *Ptr << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Adding RT check for range:" << *Ptr << '\n'; } } while (0); | |||
2075 | unsigned AS = Ptr->getType()->getPointerAddressSpace(); | |||
2076 | ||||
2077 | // Use this type for pointer arithmetic. | |||
2078 | Type *PtrArithTy = Type::getInt8PtrTy(Ctx, AS); | |||
2079 | ||||
2080 | Value *Start = Exp.expandCodeFor(PtrRtCheck->Starts[i], PtrArithTy, Loc); | |||
2081 | Value *End = Exp.expandCodeFor(PtrRtCheck->Ends[i], PtrArithTy, Loc); | |||
2082 | Starts.push_back(Start); | |||
2083 | Ends.push_back(End); | |||
2084 | } | |||
2085 | } | |||
2086 | ||||
2087 | IRBuilder<> ChkBuilder(Loc); | |||
2088 | // Our instructions might fold to a constant. | |||
2089 | Value *MemoryRuntimeCheck = nullptr; | |||
2090 | for (unsigned i = 0; i < NumPointers; ++i) { | |||
2091 | for (unsigned j = i+1; j < NumPointers; ++j) { | |||
2092 | // No need to check if two readonly pointers intersect. | |||
2093 | if (!PtrRtCheck->IsWritePtr[i] && !PtrRtCheck->IsWritePtr[j]) | |||
2094 | continue; | |||
2095 | ||||
2096 | // Only need to check pointers between two different dependency sets. | |||
2097 | if (PtrRtCheck->DependencySetId[i] == PtrRtCheck->DependencySetId[j]) | |||
2098 | continue; | |||
2099 | // Only need to check pointers in the same alias set. | |||
2100 | if (PtrRtCheck->AliasSetId[i] != PtrRtCheck->AliasSetId[j]) | |||
2101 | continue; | |||
2102 | ||||
2103 | unsigned AS0 = Starts[i]->getType()->getPointerAddressSpace(); | |||
2104 | unsigned AS1 = Starts[j]->getType()->getPointerAddressSpace(); | |||
2105 | ||||
2106 | assert((AS0 == Ends[j]->getType()->getPointerAddressSpace()) &&(((AS0 == Ends[j]->getType()->getPointerAddressSpace()) && (AS1 == Ends[i]->getType()->getPointerAddressSpace ()) && "Trying to bounds check pointers with different address spaces" ) ? static_cast<void> (0) : __assert_fail ("(AS0 == Ends[j]->getType()->getPointerAddressSpace()) && (AS1 == Ends[i]->getType()->getPointerAddressSpace()) && \"Trying to bounds check pointers with different address spaces\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2108, __PRETTY_FUNCTION__)) | |||
2107 | (AS1 == Ends[i]->getType()->getPointerAddressSpace()) &&(((AS0 == Ends[j]->getType()->getPointerAddressSpace()) && (AS1 == Ends[i]->getType()->getPointerAddressSpace ()) && "Trying to bounds check pointers with different address spaces" ) ? static_cast<void> (0) : __assert_fail ("(AS0 == Ends[j]->getType()->getPointerAddressSpace()) && (AS1 == Ends[i]->getType()->getPointerAddressSpace()) && \"Trying to bounds check pointers with different address spaces\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2108, __PRETTY_FUNCTION__)) | |||
2108 | "Trying to bounds check pointers with different address spaces")(((AS0 == Ends[j]->getType()->getPointerAddressSpace()) && (AS1 == Ends[i]->getType()->getPointerAddressSpace ()) && "Trying to bounds check pointers with different address spaces" ) ? static_cast<void> (0) : __assert_fail ("(AS0 == Ends[j]->getType()->getPointerAddressSpace()) && (AS1 == Ends[i]->getType()->getPointerAddressSpace()) && \"Trying to bounds check pointers with different address spaces\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2108, __PRETTY_FUNCTION__)); | |||
2109 | ||||
2110 | Type *PtrArithTy0 = Type::getInt8PtrTy(Ctx, AS0); | |||
2111 | Type *PtrArithTy1 = Type::getInt8PtrTy(Ctx, AS1); | |||
2112 | ||||
2113 | Value *Start0 = ChkBuilder.CreateBitCast(Starts[i], PtrArithTy0, "bc"); | |||
2114 | Value *Start1 = ChkBuilder.CreateBitCast(Starts[j], PtrArithTy1, "bc"); | |||
2115 | Value *End0 = ChkBuilder.CreateBitCast(Ends[i], PtrArithTy1, "bc"); | |||
2116 | Value *End1 = ChkBuilder.CreateBitCast(Ends[j], PtrArithTy0, "bc"); | |||
2117 | ||||
2118 | Value *Cmp0 = ChkBuilder.CreateICmpULE(Start0, End1, "bound0"); | |||
2119 | FirstInst = getFirstInst(FirstInst, Cmp0, Loc); | |||
2120 | Value *Cmp1 = ChkBuilder.CreateICmpULE(Start1, End0, "bound1"); | |||
2121 | FirstInst = getFirstInst(FirstInst, Cmp1, Loc); | |||
2122 | Value *IsConflict = ChkBuilder.CreateAnd(Cmp0, Cmp1, "found.conflict"); | |||
2123 | FirstInst = getFirstInst(FirstInst, IsConflict, Loc); | |||
2124 | if (MemoryRuntimeCheck) { | |||
2125 | IsConflict = ChkBuilder.CreateOr(MemoryRuntimeCheck, IsConflict, | |||
2126 | "conflict.rdx"); | |||
2127 | FirstInst = getFirstInst(FirstInst, IsConflict, Loc); | |||
2128 | } | |||
2129 | MemoryRuntimeCheck = IsConflict; | |||
2130 | } | |||
2131 | } | |||
2132 | ||||
2133 | // We have to do this trickery because the IRBuilder might fold the check to a | |||
2134 | // constant expression in which case there is no Instruction anchored in a | |||
2135 | // the block. | |||
2136 | Instruction *Check = BinaryOperator::CreateAnd(MemoryRuntimeCheck, | |||
2137 | ConstantInt::getTrue(Ctx)); | |||
2138 | ChkBuilder.Insert(Check, "memcheck.conflict"); | |||
2139 | FirstInst = getFirstInst(FirstInst, Check, Loc); | |||
2140 | return std::make_pair(FirstInst, Check); | |||
2141 | } | |||
2142 | ||||
2143 | void InnerLoopVectorizer::createEmptyLoop() { | |||
2144 | /* | |||
2145 | In this function we generate a new loop. The new loop will contain | |||
2146 | the vectorized instructions while the old loop will continue to run the | |||
2147 | scalar remainder. | |||
2148 | ||||
2149 | [ ] <-- Back-edge taken count overflow check. | |||
2150 | / | | |||
2151 | / v | |||
2152 | | [ ] <-- vector loop bypass (may consist of multiple blocks). | |||
2153 | | / | | |||
2154 | | / v | |||
2155 | || [ ] <-- vector pre header. | |||
2156 | || | | |||
2157 | || v | |||
2158 | || [ ] \ | |||
2159 | || [ ]_| <-- vector loop. | |||
2160 | || | | |||
2161 | | \ v | |||
2162 | | >[ ] <--- middle-block. | |||
2163 | | / | | |||
2164 | | / v | |||
2165 | -|- >[ ] <--- new preheader. | |||
2166 | | | | |||
2167 | | v | |||
2168 | | [ ] \ | |||
2169 | | [ ]_| <-- old scalar loop to handle remainder. | |||
2170 | \ | | |||
2171 | \ v | |||
2172 | >[ ] <-- exit block. | |||
2173 | ... | |||
2174 | */ | |||
2175 | ||||
2176 | BasicBlock *OldBasicBlock = OrigLoop->getHeader(); | |||
2177 | BasicBlock *BypassBlock = OrigLoop->getLoopPreheader(); | |||
2178 | BasicBlock *ExitBlock = OrigLoop->getExitBlock(); | |||
2179 | assert(BypassBlock && "Invalid loop structure")((BypassBlock && "Invalid loop structure") ? static_cast <void> (0) : __assert_fail ("BypassBlock && \"Invalid loop structure\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2179, __PRETTY_FUNCTION__)); | |||
2180 | assert(ExitBlock && "Must have an exit block")((ExitBlock && "Must have an exit block") ? static_cast <void> (0) : __assert_fail ("ExitBlock && \"Must have an exit block\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2180, __PRETTY_FUNCTION__)); | |||
2181 | ||||
2182 | // Some loops have a single integer induction variable, while other loops | |||
2183 | // don't. One example is c++ iterators that often have multiple pointer | |||
2184 | // induction variables. In the code below we also support a case where we | |||
2185 | // don't have a single induction variable. | |||
2186 | OldInduction = Legal->getInduction(); | |||
2187 | Type *IdxTy = Legal->getWidestInductionType(); | |||
2188 | ||||
2189 | // Find the loop boundaries. | |||
2190 | const SCEV *ExitCount = SE->getBackedgeTakenCount(OrigLoop); | |||
2191 | assert(ExitCount != SE->getCouldNotCompute() && "Invalid loop count")((ExitCount != SE->getCouldNotCompute() && "Invalid loop count" ) ? static_cast<void> (0) : __assert_fail ("ExitCount != SE->getCouldNotCompute() && \"Invalid loop count\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2191, __PRETTY_FUNCTION__)); | |||
2192 | ||||
2193 | // The exit count might have the type of i64 while the phi is i32. This can | |||
2194 | // happen if we have an induction variable that is sign extended before the | |||
2195 | // compare. The only way that we get a backedge taken count is that the | |||
2196 | // induction variable was signed and as such will not overflow. In such a case | |||
2197 | // truncation is legal. | |||
2198 | if (ExitCount->getType()->getPrimitiveSizeInBits() > | |||
2199 | IdxTy->getPrimitiveSizeInBits()) | |||
2200 | ExitCount = SE->getTruncateOrNoop(ExitCount, IdxTy); | |||
2201 | ||||
2202 | const SCEV *BackedgeTakeCount = SE->getNoopOrZeroExtend(ExitCount, IdxTy); | |||
2203 | // Get the total trip count from the count by adding 1. | |||
2204 | ExitCount = SE->getAddExpr(BackedgeTakeCount, | |||
2205 | SE->getConstant(BackedgeTakeCount->getType(), 1)); | |||
2206 | ||||
2207 | // Expand the trip count and place the new instructions in the preheader. | |||
2208 | // Notice that the pre-header does not change, only the loop body. | |||
2209 | SCEVExpander Exp(*SE, "induction"); | |||
2210 | ||||
2211 | // We need to test whether the backedge-taken count is uint##_max. Adding one | |||
2212 | // to it will cause overflow and an incorrect loop trip count in the vector | |||
2213 | // body. In case of overflow we want to directly jump to the scalar remainder | |||
2214 | // loop. | |||
2215 | Value *BackedgeCount = | |||
2216 | Exp.expandCodeFor(BackedgeTakeCount, BackedgeTakeCount->getType(), | |||
2217 | BypassBlock->getTerminator()); | |||
2218 | if (BackedgeCount->getType()->isPointerTy()) | |||
2219 | BackedgeCount = CastInst::CreatePointerCast(BackedgeCount, IdxTy, | |||
2220 | "backedge.ptrcnt.to.int", | |||
2221 | BypassBlock->getTerminator()); | |||
2222 | Instruction *CheckBCOverflow = | |||
2223 | CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_EQ, BackedgeCount, | |||
2224 | Constant::getAllOnesValue(BackedgeCount->getType()), | |||
2225 | "backedge.overflow", BypassBlock->getTerminator()); | |||
2226 | ||||
2227 | // The loop index does not have to start at Zero. Find the original start | |||
2228 | // value from the induction PHI node. If we don't have an induction variable | |||
2229 | // then we know that it starts at zero. | |||
2230 | Builder.SetInsertPoint(BypassBlock->getTerminator()); | |||
2231 | Value *StartIdx = ExtendedIdx = OldInduction ? | |||
2232 | Builder.CreateZExt(OldInduction->getIncomingValueForBlock(BypassBlock), | |||
2233 | IdxTy): | |||
2234 | ConstantInt::get(IdxTy, 0); | |||
2235 | ||||
2236 | // We need an instruction to anchor the overflow check on. StartIdx needs to | |||
2237 | // be defined before the overflow check branch. Because the scalar preheader | |||
2238 | // is going to merge the start index and so the overflow branch block needs to | |||
2239 | // contain a definition of the start index. | |||
2240 | Instruction *OverflowCheckAnchor = BinaryOperator::CreateAdd( | |||
2241 | StartIdx, ConstantInt::get(IdxTy, 0), "overflow.check.anchor", | |||
2242 | BypassBlock->getTerminator()); | |||
2243 | ||||
2244 | // Count holds the overall loop count (N). | |||
2245 | Value *Count = Exp.expandCodeFor(ExitCount, ExitCount->getType(), | |||
2246 | BypassBlock->getTerminator()); | |||
2247 | ||||
2248 | LoopBypassBlocks.push_back(BypassBlock); | |||
2249 | ||||
2250 | // Split the single block loop into the two loop structure described above. | |||
2251 | BasicBlock *VectorPH = | |||
2252 | BypassBlock->splitBasicBlock(BypassBlock->getTerminator(), "vector.ph"); | |||
2253 | BasicBlock *VecBody = | |||
2254 | VectorPH->splitBasicBlock(VectorPH->getTerminator(), "vector.body"); | |||
2255 | BasicBlock *MiddleBlock = | |||
2256 | VecBody->splitBasicBlock(VecBody->getTerminator(), "middle.block"); | |||
2257 | BasicBlock *ScalarPH = | |||
2258 | MiddleBlock->splitBasicBlock(MiddleBlock->getTerminator(), "scalar.ph"); | |||
2259 | ||||
2260 | // Create and register the new vector loop. | |||
2261 | Loop* Lp = new Loop(); | |||
2262 | Loop *ParentLoop = OrigLoop->getParentLoop(); | |||
2263 | ||||
2264 | // Insert the new loop into the loop nest and register the new basic blocks | |||
2265 | // before calling any utilities such as SCEV that require valid LoopInfo. | |||
2266 | if (ParentLoop) { | |||
2267 | ParentLoop->addChildLoop(Lp); | |||
2268 | ParentLoop->addBasicBlockToLoop(ScalarPH, LI->getBase()); | |||
2269 | ParentLoop->addBasicBlockToLoop(VectorPH, LI->getBase()); | |||
2270 | ParentLoop->addBasicBlockToLoop(MiddleBlock, LI->getBase()); | |||
2271 | } else { | |||
2272 | LI->addTopLevelLoop(Lp); | |||
2273 | } | |||
2274 | Lp->addBasicBlockToLoop(VecBody, LI->getBase()); | |||
2275 | ||||
2276 | // Use this IR builder to create the loop instructions (Phi, Br, Cmp) | |||
2277 | // inside the loop. | |||
2278 | Builder.SetInsertPoint(VecBody->getFirstNonPHI()); | |||
2279 | ||||
2280 | // Generate the induction variable. | |||
2281 | setDebugLocFromInst(Builder, getDebugLocFromInstOrOperands(OldInduction)); | |||
2282 | Induction = Builder.CreatePHI(IdxTy, 2, "index"); | |||
2283 | // The loop step is equal to the vectorization factor (num of SIMD elements) | |||
2284 | // times the unroll factor (num of SIMD instructions). | |||
2285 | Constant *Step = ConstantInt::get(IdxTy, VF * UF); | |||
2286 | ||||
2287 | // This is the IR builder that we use to add all of the logic for bypassing | |||
2288 | // the new vector loop. | |||
2289 | IRBuilder<> BypassBuilder(BypassBlock->getTerminator()); | |||
2290 | setDebugLocFromInst(BypassBuilder, | |||
2291 | getDebugLocFromInstOrOperands(OldInduction)); | |||
2292 | ||||
2293 | // We may need to extend the index in case there is a type mismatch. | |||
2294 | // We know that the count starts at zero and does not overflow. | |||
2295 | if (Count->getType() != IdxTy) { | |||
2296 | // The exit count can be of pointer type. Convert it to the correct | |||
2297 | // integer type. | |||
2298 | if (ExitCount->getType()->isPointerTy()) | |||
2299 | Count = BypassBuilder.CreatePointerCast(Count, IdxTy, "ptrcnt.to.int"); | |||
2300 | else | |||
2301 | Count = BypassBuilder.CreateZExtOrTrunc(Count, IdxTy, "cnt.cast"); | |||
2302 | } | |||
2303 | ||||
2304 | // Add the start index to the loop count to get the new end index. | |||
2305 | Value *IdxEnd = BypassBuilder.CreateAdd(Count, StartIdx, "end.idx"); | |||
2306 | ||||
2307 | // Now we need to generate the expression for N - (N % VF), which is | |||
2308 | // the part that the vectorized body will execute. | |||
2309 | Value *R = BypassBuilder.CreateURem(Count, Step, "n.mod.vf"); | |||
2310 | Value *CountRoundDown = BypassBuilder.CreateSub(Count, R, "n.vec"); | |||
2311 | Value *IdxEndRoundDown = BypassBuilder.CreateAdd(CountRoundDown, StartIdx, | |||
2312 | "end.idx.rnd.down"); | |||
2313 | ||||
2314 | // Now, compare the new count to zero. If it is zero skip the vector loop and | |||
2315 | // jump to the scalar loop. | |||
2316 | Value *Cmp = | |||
2317 | BypassBuilder.CreateICmpEQ(IdxEndRoundDown, StartIdx, "cmp.zero"); | |||
2318 | ||||
2319 | BasicBlock *LastBypassBlock = BypassBlock; | |||
2320 | ||||
2321 | // Generate code to check that the loops trip count that we computed by adding | |||
2322 | // one to the backedge-taken count will not overflow. | |||
2323 | { | |||
2324 | auto PastOverflowCheck = | |||
2325 | std::next(BasicBlock::iterator(OverflowCheckAnchor)); | |||
2326 | BasicBlock *CheckBlock = | |||
2327 | LastBypassBlock->splitBasicBlock(PastOverflowCheck, "overflow.checked"); | |||
2328 | if (ParentLoop) | |||
2329 | ParentLoop->addBasicBlockToLoop(CheckBlock, LI->getBase()); | |||
2330 | LoopBypassBlocks.push_back(CheckBlock); | |||
2331 | Instruction *OldTerm = LastBypassBlock->getTerminator(); | |||
2332 | BranchInst::Create(ScalarPH, CheckBlock, CheckBCOverflow, OldTerm); | |||
2333 | OldTerm->eraseFromParent(); | |||
2334 | LastBypassBlock = CheckBlock; | |||
2335 | } | |||
2336 | ||||
2337 | // Generate the code to check that the strides we assumed to be one are really | |||
2338 | // one. We want the new basic block to start at the first instruction in a | |||
2339 | // sequence of instructions that form a check. | |||
2340 | Instruction *StrideCheck; | |||
2341 | Instruction *FirstCheckInst; | |||
2342 | std::tie(FirstCheckInst, StrideCheck) = | |||
2343 | addStrideCheck(LastBypassBlock->getTerminator()); | |||
2344 | if (StrideCheck) { | |||
2345 | // Create a new block containing the stride check. | |||
2346 | BasicBlock *CheckBlock = | |||
2347 | LastBypassBlock->splitBasicBlock(FirstCheckInst, "vector.stridecheck"); | |||
2348 | if (ParentLoop) | |||
2349 | ParentLoop->addBasicBlockToLoop(CheckBlock, LI->getBase()); | |||
2350 | LoopBypassBlocks.push_back(CheckBlock); | |||
2351 | ||||
2352 | // Replace the branch into the memory check block with a conditional branch | |||
2353 | // for the "few elements case". | |||
2354 | Instruction *OldTerm = LastBypassBlock->getTerminator(); | |||
2355 | BranchInst::Create(MiddleBlock, CheckBlock, Cmp, OldTerm); | |||
2356 | OldTerm->eraseFromParent(); | |||
2357 | ||||
2358 | Cmp = StrideCheck; | |||
2359 | LastBypassBlock = CheckBlock; | |||
2360 | } | |||
2361 | ||||
2362 | // Generate the code that checks in runtime if arrays overlap. We put the | |||
2363 | // checks into a separate block to make the more common case of few elements | |||
2364 | // faster. | |||
2365 | Instruction *MemRuntimeCheck; | |||
2366 | std::tie(FirstCheckInst, MemRuntimeCheck) = | |||
2367 | addRuntimeCheck(LastBypassBlock->getTerminator()); | |||
2368 | if (MemRuntimeCheck) { | |||
2369 | // Create a new block containing the memory check. | |||
2370 | BasicBlock *CheckBlock = | |||
2371 | LastBypassBlock->splitBasicBlock(MemRuntimeCheck, "vector.memcheck"); | |||
2372 | if (ParentLoop) | |||
2373 | ParentLoop->addBasicBlockToLoop(CheckBlock, LI->getBase()); | |||
2374 | LoopBypassBlocks.push_back(CheckBlock); | |||
2375 | ||||
2376 | // Replace the branch into the memory check block with a conditional branch | |||
2377 | // for the "few elements case". | |||
2378 | Instruction *OldTerm = LastBypassBlock->getTerminator(); | |||
2379 | BranchInst::Create(MiddleBlock, CheckBlock, Cmp, OldTerm); | |||
2380 | OldTerm->eraseFromParent(); | |||
2381 | ||||
2382 | Cmp = MemRuntimeCheck; | |||
2383 | LastBypassBlock = CheckBlock; | |||
2384 | } | |||
2385 | ||||
2386 | LastBypassBlock->getTerminator()->eraseFromParent(); | |||
2387 | BranchInst::Create(MiddleBlock, VectorPH, Cmp, | |||
2388 | LastBypassBlock); | |||
2389 | ||||
2390 | // We are going to resume the execution of the scalar loop. | |||
2391 | // Go over all of the induction variables that we found and fix the | |||
2392 | // PHIs that are left in the scalar version of the loop. | |||
2393 | // The starting values of PHI nodes depend on the counter of the last | |||
2394 | // iteration in the vectorized loop. | |||
2395 | // If we come from a bypass edge then we need to start from the original | |||
2396 | // start value. | |||
2397 | ||||
2398 | // This variable saves the new starting index for the scalar loop. | |||
2399 | PHINode *ResumeIndex = nullptr; | |||
2400 | LoopVectorizationLegality::InductionList::iterator I, E; | |||
2401 | LoopVectorizationLegality::InductionList *List = Legal->getInductionVars(); | |||
2402 | // Set builder to point to last bypass block. | |||
2403 | BypassBuilder.SetInsertPoint(LoopBypassBlocks.back()->getTerminator()); | |||
2404 | for (I = List->begin(), E = List->end(); I != E; ++I) { | |||
2405 | PHINode *OrigPhi = I->first; | |||
2406 | LoopVectorizationLegality::InductionInfo II = I->second; | |||
2407 | ||||
2408 | Type *ResumeValTy = (OrigPhi == OldInduction) ? IdxTy : OrigPhi->getType(); | |||
2409 | PHINode *ResumeVal = PHINode::Create(ResumeValTy, 2, "resume.val", | |||
2410 | MiddleBlock->getTerminator()); | |||
2411 | // We might have extended the type of the induction variable but we need a | |||
2412 | // truncated version for the scalar loop. | |||
2413 | PHINode *TruncResumeVal = (OrigPhi == OldInduction) ? | |||
2414 | PHINode::Create(OrigPhi->getType(), 2, "trunc.resume.val", | |||
2415 | MiddleBlock->getTerminator()) : nullptr; | |||
2416 | ||||
2417 | // Create phi nodes to merge from the backedge-taken check block. | |||
2418 | PHINode *BCResumeVal = PHINode::Create(ResumeValTy, 3, "bc.resume.val", | |||
2419 | ScalarPH->getTerminator()); | |||
2420 | BCResumeVal->addIncoming(ResumeVal, MiddleBlock); | |||
2421 | ||||
2422 | PHINode *BCTruncResumeVal = nullptr; | |||
2423 | if (OrigPhi == OldInduction) { | |||
2424 | BCTruncResumeVal = | |||
2425 | PHINode::Create(OrigPhi->getType(), 2, "bc.trunc.resume.val", | |||
2426 | ScalarPH->getTerminator()); | |||
2427 | BCTruncResumeVal->addIncoming(TruncResumeVal, MiddleBlock); | |||
2428 | } | |||
2429 | ||||
2430 | Value *EndValue = nullptr; | |||
2431 | switch (II.IK) { | |||
2432 | case LoopVectorizationLegality::IK_NoInduction: | |||
2433 | llvm_unreachable("Unknown induction")::llvm::llvm_unreachable_internal("Unknown induction", "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2433); | |||
2434 | case LoopVectorizationLegality::IK_IntInduction: { | |||
2435 | // Handle the integer induction counter. | |||
2436 | assert(OrigPhi->getType()->isIntegerTy() && "Invalid type")((OrigPhi->getType()->isIntegerTy() && "Invalid type" ) ? static_cast<void> (0) : __assert_fail ("OrigPhi->getType()->isIntegerTy() && \"Invalid type\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2436, __PRETTY_FUNCTION__)); | |||
2437 | ||||
2438 | // We have the canonical induction variable. | |||
2439 | if (OrigPhi == OldInduction) { | |||
2440 | // Create a truncated version of the resume value for the scalar loop, | |||
2441 | // we might have promoted the type to a larger width. | |||
2442 | EndValue = | |||
2443 | BypassBuilder.CreateTrunc(IdxEndRoundDown, OrigPhi->getType()); | |||
2444 | // The new PHI merges the original incoming value, in case of a bypass, | |||
2445 | // or the value at the end of the vectorized loop. | |||
2446 | for (unsigned I = 1, E = LoopBypassBlocks.size(); I != E; ++I) | |||
2447 | TruncResumeVal->addIncoming(II.StartValue, LoopBypassBlocks[I]); | |||
2448 | TruncResumeVal->addIncoming(EndValue, VecBody); | |||
2449 | ||||
2450 | BCTruncResumeVal->addIncoming(II.StartValue, LoopBypassBlocks[0]); | |||
2451 | ||||
2452 | // We know what the end value is. | |||
2453 | EndValue = IdxEndRoundDown; | |||
2454 | // We also know which PHI node holds it. | |||
2455 | ResumeIndex = ResumeVal; | |||
2456 | break; | |||
2457 | } | |||
2458 | ||||
2459 | // Not the canonical induction variable - add the vector loop count to the | |||
2460 | // start value. | |||
2461 | Value *CRD = BypassBuilder.CreateSExtOrTrunc(CountRoundDown, | |||
2462 | II.StartValue->getType(), | |||
2463 | "cast.crd"); | |||
2464 | EndValue = BypassBuilder.CreateAdd(CRD, II.StartValue , "ind.end"); | |||
2465 | break; | |||
2466 | } | |||
2467 | case LoopVectorizationLegality::IK_ReverseIntInduction: { | |||
2468 | // Convert the CountRoundDown variable to the PHI size. | |||
2469 | Value *CRD = BypassBuilder.CreateSExtOrTrunc(CountRoundDown, | |||
2470 | II.StartValue->getType(), | |||
2471 | "cast.crd"); | |||
2472 | // Handle reverse integer induction counter. | |||
2473 | EndValue = BypassBuilder.CreateSub(II.StartValue, CRD, "rev.ind.end"); | |||
2474 | break; | |||
2475 | } | |||
2476 | case LoopVectorizationLegality::IK_PtrInduction: { | |||
2477 | // For pointer induction variables, calculate the offset using | |||
2478 | // the end index. | |||
2479 | EndValue = BypassBuilder.CreateGEP(II.StartValue, CountRoundDown, | |||
2480 | "ptr.ind.end"); | |||
2481 | break; | |||
2482 | } | |||
2483 | case LoopVectorizationLegality::IK_ReversePtrInduction: { | |||
2484 | // The value at the end of the loop for the reverse pointer is calculated | |||
2485 | // by creating a GEP with a negative index starting from the start value. | |||
2486 | Value *Zero = ConstantInt::get(CountRoundDown->getType(), 0); | |||
2487 | Value *NegIdx = BypassBuilder.CreateSub(Zero, CountRoundDown, | |||
2488 | "rev.ind.end"); | |||
2489 | EndValue = BypassBuilder.CreateGEP(II.StartValue, NegIdx, | |||
2490 | "rev.ptr.ind.end"); | |||
2491 | break; | |||
2492 | } | |||
2493 | }// end of case | |||
2494 | ||||
2495 | // The new PHI merges the original incoming value, in case of a bypass, | |||
2496 | // or the value at the end of the vectorized loop. | |||
2497 | for (unsigned I = 1, E = LoopBypassBlocks.size(); I != E; ++I) { | |||
2498 | if (OrigPhi == OldInduction) | |||
2499 | ResumeVal->addIncoming(StartIdx, LoopBypassBlocks[I]); | |||
2500 | else | |||
2501 | ResumeVal->addIncoming(II.StartValue, LoopBypassBlocks[I]); | |||
2502 | } | |||
2503 | ResumeVal->addIncoming(EndValue, VecBody); | |||
2504 | ||||
2505 | // Fix the scalar body counter (PHI node). | |||
2506 | unsigned BlockIdx = OrigPhi->getBasicBlockIndex(ScalarPH); | |||
2507 | ||||
2508 | // The old induction's phi node in the scalar body needs the truncated | |||
2509 | // value. | |||
2510 | if (OrigPhi == OldInduction) { | |||
2511 | BCResumeVal->addIncoming(StartIdx, LoopBypassBlocks[0]); | |||
2512 | OrigPhi->setIncomingValue(BlockIdx, BCTruncResumeVal); | |||
2513 | } else { | |||
2514 | BCResumeVal->addIncoming(II.StartValue, LoopBypassBlocks[0]); | |||
2515 | OrigPhi->setIncomingValue(BlockIdx, BCResumeVal); | |||
2516 | } | |||
2517 | } | |||
2518 | ||||
2519 | // If we are generating a new induction variable then we also need to | |||
2520 | // generate the code that calculates the exit value. This value is not | |||
2521 | // simply the end of the counter because we may skip the vectorized body | |||
2522 | // in case of a runtime check. | |||
2523 | if (!OldInduction){ | |||
2524 | assert(!ResumeIndex && "Unexpected resume value found")((!ResumeIndex && "Unexpected resume value found") ? static_cast <void> (0) : __assert_fail ("!ResumeIndex && \"Unexpected resume value found\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2524, __PRETTY_FUNCTION__)); | |||
2525 | ResumeIndex = PHINode::Create(IdxTy, 2, "new.indc.resume.val", | |||
2526 | MiddleBlock->getTerminator()); | |||
2527 | for (unsigned I = 1, E = LoopBypassBlocks.size(); I != E; ++I) | |||
2528 | ResumeIndex->addIncoming(StartIdx, LoopBypassBlocks[I]); | |||
2529 | ResumeIndex->addIncoming(IdxEndRoundDown, VecBody); | |||
2530 | } | |||
2531 | ||||
2532 | // Make sure that we found the index where scalar loop needs to continue. | |||
2533 | assert(ResumeIndex && ResumeIndex->getType()->isIntegerTy() &&((ResumeIndex && ResumeIndex->getType()->isIntegerTy () && "Invalid resume Index") ? static_cast<void> (0) : __assert_fail ("ResumeIndex && ResumeIndex->getType()->isIntegerTy() && \"Invalid resume Index\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2534, __PRETTY_FUNCTION__)) | |||
2534 | "Invalid resume Index")((ResumeIndex && ResumeIndex->getType()->isIntegerTy () && "Invalid resume Index") ? static_cast<void> (0) : __assert_fail ("ResumeIndex && ResumeIndex->getType()->isIntegerTy() && \"Invalid resume Index\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2534, __PRETTY_FUNCTION__)); | |||
2535 | ||||
2536 | // Add a check in the middle block to see if we have completed | |||
2537 | // all of the iterations in the first vector loop. | |||
2538 | // If (N - N%VF) == N, then we *don't* need to run the remainder. | |||
2539 | Value *CmpN = CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_EQ, IdxEnd, | |||
2540 | ResumeIndex, "cmp.n", | |||
2541 | MiddleBlock->getTerminator()); | |||
2542 | ||||
2543 | BranchInst::Create(ExitBlock, ScalarPH, CmpN, MiddleBlock->getTerminator()); | |||
2544 | // Remove the old terminator. | |||
2545 | MiddleBlock->getTerminator()->eraseFromParent(); | |||
2546 | ||||
2547 | // Create i+1 and fill the PHINode. | |||
2548 | Value *NextIdx = Builder.CreateAdd(Induction, Step, "index.next"); | |||
2549 | Induction->addIncoming(StartIdx, VectorPH); | |||
2550 | Induction->addIncoming(NextIdx, VecBody); | |||
2551 | // Create the compare. | |||
2552 | Value *ICmp = Builder.CreateICmpEQ(NextIdx, IdxEndRoundDown); | |||
2553 | Builder.CreateCondBr(ICmp, MiddleBlock, VecBody); | |||
2554 | ||||
2555 | // Now we have two terminators. Remove the old one from the block. | |||
2556 | VecBody->getTerminator()->eraseFromParent(); | |||
2557 | ||||
2558 | // Get ready to start creating new instructions into the vectorized body. | |||
2559 | Builder.SetInsertPoint(VecBody->getFirstInsertionPt()); | |||
2560 | ||||
2561 | // Save the state. | |||
2562 | LoopVectorPreHeader = VectorPH; | |||
2563 | LoopScalarPreHeader = ScalarPH; | |||
2564 | LoopMiddleBlock = MiddleBlock; | |||
2565 | LoopExitBlock = ExitBlock; | |||
2566 | LoopVectorBody.push_back(VecBody); | |||
2567 | LoopScalarBody = OldBasicBlock; | |||
2568 | ||||
2569 | LoopVectorizeHints Hints(Lp, true); | |||
2570 | Hints.setAlreadyVectorized(); | |||
2571 | } | |||
2572 | ||||
2573 | /// This function returns the identity element (or neutral element) for | |||
2574 | /// the operation K. | |||
2575 | Constant* | |||
2576 | LoopVectorizationLegality::getReductionIdentity(ReductionKind K, Type *Tp) { | |||
2577 | switch (K) { | |||
2578 | case RK_IntegerXor: | |||
2579 | case RK_IntegerAdd: | |||
2580 | case RK_IntegerOr: | |||
2581 | // Adding, Xoring, Oring zero to a number does not change it. | |||
2582 | return ConstantInt::get(Tp, 0); | |||
2583 | case RK_IntegerMult: | |||
2584 | // Multiplying a number by 1 does not change it. | |||
2585 | return ConstantInt::get(Tp, 1); | |||
2586 | case RK_IntegerAnd: | |||
2587 | // AND-ing a number with an all-1 value does not change it. | |||
2588 | return ConstantInt::get(Tp, -1, true); | |||
2589 | case RK_FloatMult: | |||
2590 | // Multiplying a number by 1 does not change it. | |||
2591 | return ConstantFP::get(Tp, 1.0L); | |||
2592 | case RK_FloatAdd: | |||
2593 | // Adding zero to a number does not change it. | |||
2594 | return ConstantFP::get(Tp, 0.0L); | |||
2595 | default: | |||
2596 | llvm_unreachable("Unknown reduction kind")::llvm::llvm_unreachable_internal("Unknown reduction kind", "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2596); | |||
2597 | } | |||
2598 | } | |||
2599 | ||||
2600 | /// This function translates the reduction kind to an LLVM binary operator. | |||
2601 | static unsigned | |||
2602 | getReductionBinOp(LoopVectorizationLegality::ReductionKind Kind) { | |||
2603 | switch (Kind) { | |||
2604 | case LoopVectorizationLegality::RK_IntegerAdd: | |||
2605 | return Instruction::Add; | |||
2606 | case LoopVectorizationLegality::RK_IntegerMult: | |||
2607 | return Instruction::Mul; | |||
2608 | case LoopVectorizationLegality::RK_IntegerOr: | |||
2609 | return Instruction::Or; | |||
2610 | case LoopVectorizationLegality::RK_IntegerAnd: | |||
2611 | return Instruction::And; | |||
2612 | case LoopVectorizationLegality::RK_IntegerXor: | |||
2613 | return Instruction::Xor; | |||
2614 | case LoopVectorizationLegality::RK_FloatMult: | |||
2615 | return Instruction::FMul; | |||
2616 | case LoopVectorizationLegality::RK_FloatAdd: | |||
2617 | return Instruction::FAdd; | |||
2618 | case LoopVectorizationLegality::RK_IntegerMinMax: | |||
2619 | return Instruction::ICmp; | |||
2620 | case LoopVectorizationLegality::RK_FloatMinMax: | |||
2621 | return Instruction::FCmp; | |||
2622 | default: | |||
2623 | llvm_unreachable("Unknown reduction operation")::llvm::llvm_unreachable_internal("Unknown reduction operation" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2623); | |||
2624 | } | |||
2625 | } | |||
2626 | ||||
2627 | Value *createMinMaxOp(IRBuilder<> &Builder, | |||
2628 | LoopVectorizationLegality::MinMaxReductionKind RK, | |||
2629 | Value *Left, | |||
2630 | Value *Right) { | |||
2631 | CmpInst::Predicate P = CmpInst::ICMP_NE; | |||
2632 | switch (RK) { | |||
2633 | default: | |||
2634 | llvm_unreachable("Unknown min/max reduction kind")::llvm::llvm_unreachable_internal("Unknown min/max reduction kind" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2634); | |||
2635 | case LoopVectorizationLegality::MRK_UIntMin: | |||
2636 | P = CmpInst::ICMP_ULT; | |||
2637 | break; | |||
2638 | case LoopVectorizationLegality::MRK_UIntMax: | |||
2639 | P = CmpInst::ICMP_UGT; | |||
2640 | break; | |||
2641 | case LoopVectorizationLegality::MRK_SIntMin: | |||
2642 | P = CmpInst::ICMP_SLT; | |||
2643 | break; | |||
2644 | case LoopVectorizationLegality::MRK_SIntMax: | |||
2645 | P = CmpInst::ICMP_SGT; | |||
2646 | break; | |||
2647 | case LoopVectorizationLegality::MRK_FloatMin: | |||
2648 | P = CmpInst::FCMP_OLT; | |||
2649 | break; | |||
2650 | case LoopVectorizationLegality::MRK_FloatMax: | |||
2651 | P = CmpInst::FCMP_OGT; | |||
2652 | break; | |||
2653 | } | |||
2654 | ||||
2655 | Value *Cmp; | |||
2656 | if (RK == LoopVectorizationLegality::MRK_FloatMin || | |||
2657 | RK == LoopVectorizationLegality::MRK_FloatMax) | |||
2658 | Cmp = Builder.CreateFCmp(P, Left, Right, "rdx.minmax.cmp"); | |||
2659 | else | |||
2660 | Cmp = Builder.CreateICmp(P, Left, Right, "rdx.minmax.cmp"); | |||
2661 | ||||
2662 | Value *Select = Builder.CreateSelect(Cmp, Left, Right, "rdx.minmax.select"); | |||
2663 | return Select; | |||
2664 | } | |||
2665 | ||||
2666 | namespace { | |||
2667 | struct CSEDenseMapInfo { | |||
2668 | static bool canHandle(Instruction *I) { | |||
2669 | return isa<InsertElementInst>(I) || isa<ExtractElementInst>(I) || | |||
2670 | isa<ShuffleVectorInst>(I) || isa<GetElementPtrInst>(I); | |||
2671 | } | |||
2672 | static inline Instruction *getEmptyKey() { | |||
2673 | return DenseMapInfo<Instruction *>::getEmptyKey(); | |||
2674 | } | |||
2675 | static inline Instruction *getTombstoneKey() { | |||
2676 | return DenseMapInfo<Instruction *>::getTombstoneKey(); | |||
2677 | } | |||
2678 | static unsigned getHashValue(Instruction *I) { | |||
2679 | assert(canHandle(I) && "Unknown instruction!")((canHandle(I) && "Unknown instruction!") ? static_cast <void> (0) : __assert_fail ("canHandle(I) && \"Unknown instruction!\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2679, __PRETTY_FUNCTION__)); | |||
2680 | return hash_combine(I->getOpcode(), hash_combine_range(I->value_op_begin(), | |||
2681 | I->value_op_end())); | |||
2682 | } | |||
2683 | static bool isEqual(Instruction *LHS, Instruction *RHS) { | |||
2684 | if (LHS == getEmptyKey() || RHS == getEmptyKey() || | |||
2685 | LHS == getTombstoneKey() || RHS == getTombstoneKey()) | |||
2686 | return LHS == RHS; | |||
2687 | return LHS->isIdenticalTo(RHS); | |||
2688 | } | |||
2689 | }; | |||
2690 | } | |||
2691 | ||||
2692 | /// \brief Check whether this block is a predicated block. | |||
2693 | /// Due to if predication of stores we might create a sequence of "if(pred) a[i] | |||
2694 | /// = ...; " blocks. We start with one vectorized basic block. For every | |||
2695 | /// conditional block we split this vectorized block. Therefore, every second | |||
2696 | /// block will be a predicated one. | |||
2697 | static bool isPredicatedBlock(unsigned BlockNum) { | |||
2698 | return BlockNum % 2; | |||
2699 | } | |||
2700 | ||||
2701 | ///\brief Perform cse of induction variable instructions. | |||
2702 | static void cse(SmallVector<BasicBlock *, 4> &BBs) { | |||
2703 | // Perform simple cse. | |||
2704 | SmallDenseMap<Instruction *, Instruction *, 4, CSEDenseMapInfo> CSEMap; | |||
2705 | for (unsigned i = 0, e = BBs.size(); i != e; ++i) { | |||
2706 | BasicBlock *BB = BBs[i]; | |||
2707 | for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E;) { | |||
2708 | Instruction *In = I++; | |||
2709 | ||||
2710 | if (!CSEDenseMapInfo::canHandle(In)) | |||
2711 | continue; | |||
2712 | ||||
2713 | // Check if we can replace this instruction with any of the | |||
2714 | // visited instructions. | |||
2715 | if (Instruction *V = CSEMap.lookup(In)) { | |||
2716 | In->replaceAllUsesWith(V); | |||
2717 | In->eraseFromParent(); | |||
2718 | continue; | |||
2719 | } | |||
2720 | // Ignore instructions in conditional blocks. We create "if (pred) a[i] = | |||
2721 | // ...;" blocks for predicated stores. Every second block is a predicated | |||
2722 | // block. | |||
2723 | if (isPredicatedBlock(i)) | |||
2724 | continue; | |||
2725 | ||||
2726 | CSEMap[In] = In; | |||
2727 | } | |||
2728 | } | |||
2729 | } | |||
2730 | ||||
2731 | /// \brief Adds a 'fast' flag to floating point operations. | |||
2732 | static Value *addFastMathFlag(Value *V) { | |||
2733 | if (isa<FPMathOperator>(V)){ | |||
2734 | FastMathFlags Flags; | |||
2735 | Flags.setUnsafeAlgebra(); | |||
2736 | cast<Instruction>(V)->setFastMathFlags(Flags); | |||
2737 | } | |||
2738 | return V; | |||
2739 | } | |||
2740 | ||||
2741 | void InnerLoopVectorizer::vectorizeLoop() { | |||
2742 | //===------------------------------------------------===// | |||
2743 | // | |||
2744 | // Notice: any optimization or new instruction that go | |||
2745 | // into the code below should be also be implemented in | |||
2746 | // the cost-model. | |||
2747 | // | |||
2748 | //===------------------------------------------------===// | |||
2749 | Constant *Zero = Builder.getInt32(0); | |||
2750 | ||||
2751 | // In order to support reduction variables we need to be able to vectorize | |||
2752 | // Phi nodes. Phi nodes have cycles, so we need to vectorize them in two | |||
2753 | // stages. First, we create a new vector PHI node with no incoming edges. | |||
2754 | // We use this value when we vectorize all of the instructions that use the | |||
2755 | // PHI. Next, after all of the instructions in the block are complete we | |||
2756 | // add the new incoming edges to the PHI. At this point all of the | |||
2757 | // instructions in the basic block are vectorized, so we can use them to | |||
2758 | // construct the PHI. | |||
2759 | PhiVector RdxPHIsToFix; | |||
2760 | ||||
2761 | // Scan the loop in a topological order to ensure that defs are vectorized | |||
2762 | // before users. | |||
2763 | LoopBlocksDFS DFS(OrigLoop); | |||
2764 | DFS.perform(LI); | |||
2765 | ||||
2766 | // Vectorize all of the blocks in the original loop. | |||
2767 | for (LoopBlocksDFS::RPOIterator bb = DFS.beginRPO(), | |||
2768 | be = DFS.endRPO(); bb != be; ++bb) | |||
2769 | vectorizeBlockInLoop(*bb, &RdxPHIsToFix); | |||
2770 | ||||
2771 | // At this point every instruction in the original loop is widened to | |||
2772 | // a vector form. We are almost done. Now, we need to fix the PHI nodes | |||
2773 | // that we vectorized. The PHI nodes are currently empty because we did | |||
2774 | // not want to introduce cycles. Notice that the remaining PHI nodes | |||
2775 | // that we need to fix are reduction variables. | |||
2776 | ||||
2777 | // Create the 'reduced' values for each of the induction vars. | |||
2778 | // The reduced values are the vector values that we scalarize and combine | |||
2779 | // after the loop is finished. | |||
2780 | for (PhiVector::iterator it = RdxPHIsToFix.begin(), e = RdxPHIsToFix.end(); | |||
2781 | it != e; ++it) { | |||
2782 | PHINode *RdxPhi = *it; | |||
2783 | assert(RdxPhi && "Unable to recover vectorized PHI")((RdxPhi && "Unable to recover vectorized PHI") ? static_cast <void> (0) : __assert_fail ("RdxPhi && \"Unable to recover vectorized PHI\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2783, __PRETTY_FUNCTION__)); | |||
2784 | ||||
2785 | // Find the reduction variable descriptor. | |||
2786 | assert(Legal->getReductionVars()->count(RdxPhi) &&((Legal->getReductionVars()->count(RdxPhi) && "Unable to find the reduction variable" ) ? static_cast<void> (0) : __assert_fail ("Legal->getReductionVars()->count(RdxPhi) && \"Unable to find the reduction variable\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2787, __PRETTY_FUNCTION__)) | |||
2787 | "Unable to find the reduction variable")((Legal->getReductionVars()->count(RdxPhi) && "Unable to find the reduction variable" ) ? static_cast<void> (0) : __assert_fail ("Legal->getReductionVars()->count(RdxPhi) && \"Unable to find the reduction variable\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2787, __PRETTY_FUNCTION__)); | |||
2788 | LoopVectorizationLegality::ReductionDescriptor RdxDesc = | |||
2789 | (*Legal->getReductionVars())[RdxPhi]; | |||
2790 | ||||
2791 | setDebugLocFromInst(Builder, RdxDesc.StartValue); | |||
2792 | ||||
2793 | // We need to generate a reduction vector from the incoming scalar. | |||
2794 | // To do so, we need to generate the 'identity' vector and override | |||
2795 | // one of the elements with the incoming scalar reduction. We need | |||
2796 | // to do it in the vector-loop preheader. | |||
2797 | Builder.SetInsertPoint(LoopBypassBlocks[1]->getTerminator()); | |||
2798 | ||||
2799 | // This is the vector-clone of the value that leaves the loop. | |||
2800 | VectorParts &VectorExit = getVectorValue(RdxDesc.LoopExitInstr); | |||
2801 | Type *VecTy = VectorExit[0]->getType(); | |||
2802 | ||||
2803 | // Find the reduction identity variable. Zero for addition, or, xor, | |||
2804 | // one for multiplication, -1 for And. | |||
2805 | Value *Identity; | |||
2806 | Value *VectorStart; | |||
2807 | if (RdxDesc.Kind == LoopVectorizationLegality::RK_IntegerMinMax || | |||
2808 | RdxDesc.Kind == LoopVectorizationLegality::RK_FloatMinMax) { | |||
2809 | // MinMax reduction have the start value as their identify. | |||
2810 | if (VF == 1) { | |||
2811 | VectorStart = Identity = RdxDesc.StartValue; | |||
2812 | } else { | |||
2813 | VectorStart = Identity = Builder.CreateVectorSplat(VF, | |||
2814 | RdxDesc.StartValue, | |||
2815 | "minmax.ident"); | |||
2816 | } | |||
2817 | } else { | |||
2818 | // Handle other reduction kinds: | |||
2819 | Constant *Iden = | |||
2820 | LoopVectorizationLegality::getReductionIdentity(RdxDesc.Kind, | |||
2821 | VecTy->getScalarType()); | |||
2822 | if (VF == 1) { | |||
2823 | Identity = Iden; | |||
2824 | // This vector is the Identity vector where the first element is the | |||
2825 | // incoming scalar reduction. | |||
2826 | VectorStart = RdxDesc.StartValue; | |||
2827 | } else { | |||
2828 | Identity = ConstantVector::getSplat(VF, Iden); | |||
2829 | ||||
2830 | // This vector is the Identity vector where the first element is the | |||
2831 | // incoming scalar reduction. | |||
2832 | VectorStart = Builder.CreateInsertElement(Identity, | |||
2833 | RdxDesc.StartValue, Zero); | |||
2834 | } | |||
2835 | } | |||
2836 | ||||
2837 | // Fix the vector-loop phi. | |||
2838 | // We created the induction variable so we know that the | |||
2839 | // preheader is the first entry. | |||
2840 | BasicBlock *VecPreheader = Induction->getIncomingBlock(0); | |||
2841 | ||||
2842 | // Reductions do not have to start at zero. They can start with | |||
2843 | // any loop invariant values. | |||
2844 | VectorParts &VecRdxPhi = WidenMap.get(RdxPhi); | |||
2845 | BasicBlock *Latch = OrigLoop->getLoopLatch(); | |||
2846 | Value *LoopVal = RdxPhi->getIncomingValueForBlock(Latch); | |||
2847 | VectorParts &Val = getVectorValue(LoopVal); | |||
2848 | for (unsigned part = 0; part < UF; ++part) { | |||
2849 | // Make sure to add the reduction stat value only to the | |||
2850 | // first unroll part. | |||
2851 | Value *StartVal = (part == 0) ? VectorStart : Identity; | |||
2852 | cast<PHINode>(VecRdxPhi[part])->addIncoming(StartVal, VecPreheader); | |||
2853 | cast<PHINode>(VecRdxPhi[part])->addIncoming(Val[part], | |||
2854 | LoopVectorBody.back()); | |||
2855 | } | |||
2856 | ||||
2857 | // Before each round, move the insertion point right between | |||
2858 | // the PHIs and the values we are going to write. | |||
2859 | // This allows us to write both PHINodes and the extractelement | |||
2860 | // instructions. | |||
2861 | Builder.SetInsertPoint(LoopMiddleBlock->getFirstInsertionPt()); | |||
2862 | ||||
2863 | VectorParts RdxParts; | |||
2864 | setDebugLocFromInst(Builder, RdxDesc.LoopExitInstr); | |||
2865 | for (unsigned part = 0; part < UF; ++part) { | |||
2866 | // This PHINode contains the vectorized reduction variable, or | |||
2867 | // the initial value vector, if we bypass the vector loop. | |||
2868 | VectorParts &RdxExitVal = getVectorValue(RdxDesc.LoopExitInstr); | |||
2869 | PHINode *NewPhi = Builder.CreatePHI(VecTy, 2, "rdx.vec.exit.phi"); | |||
2870 | Value *StartVal = (part == 0) ? VectorStart : Identity; | |||
2871 | for (unsigned I = 1, E = LoopBypassBlocks.size(); I != E; ++I) | |||
2872 | NewPhi->addIncoming(StartVal, LoopBypassBlocks[I]); | |||
2873 | NewPhi->addIncoming(RdxExitVal[part], | |||
2874 | LoopVectorBody.back()); | |||
2875 | RdxParts.push_back(NewPhi); | |||
2876 | } | |||
2877 | ||||
2878 | // Reduce all of the unrolled parts into a single vector. | |||
2879 | Value *ReducedPartRdx = RdxParts[0]; | |||
2880 | unsigned Op = getReductionBinOp(RdxDesc.Kind); | |||
2881 | setDebugLocFromInst(Builder, ReducedPartRdx); | |||
2882 | for (unsigned part = 1; part < UF; ++part) { | |||
2883 | if (Op != Instruction::ICmp && Op != Instruction::FCmp) | |||
2884 | // Floating point operations had to be 'fast' to enable the reduction. | |||
2885 | ReducedPartRdx = addFastMathFlag( | |||
2886 | Builder.CreateBinOp((Instruction::BinaryOps)Op, RdxParts[part], | |||
2887 | ReducedPartRdx, "bin.rdx")); | |||
2888 | else | |||
2889 | ReducedPartRdx = createMinMaxOp(Builder, RdxDesc.MinMaxKind, | |||
2890 | ReducedPartRdx, RdxParts[part]); | |||
2891 | } | |||
2892 | ||||
2893 | if (VF > 1) { | |||
2894 | // VF is a power of 2 so we can emit the reduction using log2(VF) shuffles | |||
2895 | // and vector ops, reducing the set of values being computed by half each | |||
2896 | // round. | |||
2897 | assert(isPowerOf2_32(VF) &&((isPowerOf2_32(VF) && "Reduction emission only supported for pow2 vectors!" ) ? static_cast<void> (0) : __assert_fail ("isPowerOf2_32(VF) && \"Reduction emission only supported for pow2 vectors!\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2898, __PRETTY_FUNCTION__)) | |||
2898 | "Reduction emission only supported for pow2 vectors!")((isPowerOf2_32(VF) && "Reduction emission only supported for pow2 vectors!" ) ? static_cast<void> (0) : __assert_fail ("isPowerOf2_32(VF) && \"Reduction emission only supported for pow2 vectors!\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2898, __PRETTY_FUNCTION__)); | |||
2899 | Value *TmpVec = ReducedPartRdx; | |||
2900 | SmallVector<Constant*, 32> ShuffleMask(VF, nullptr); | |||
2901 | for (unsigned i = VF; i != 1; i >>= 1) { | |||
2902 | // Move the upper half of the vector to the lower half. | |||
2903 | for (unsigned j = 0; j != i/2; ++j) | |||
2904 | ShuffleMask[j] = Builder.getInt32(i/2 + j); | |||
2905 | ||||
2906 | // Fill the rest of the mask with undef. | |||
2907 | std::fill(&ShuffleMask[i/2], ShuffleMask.end(), | |||
2908 | UndefValue::get(Builder.getInt32Ty())); | |||
2909 | ||||
2910 | Value *Shuf = | |||
2911 | Builder.CreateShuffleVector(TmpVec, | |||
2912 | UndefValue::get(TmpVec->getType()), | |||
2913 | ConstantVector::get(ShuffleMask), | |||
2914 | "rdx.shuf"); | |||
2915 | ||||
2916 | if (Op != Instruction::ICmp && Op != Instruction::FCmp) | |||
2917 | // Floating point operations had to be 'fast' to enable the reduction. | |||
2918 | TmpVec = addFastMathFlag(Builder.CreateBinOp( | |||
2919 | (Instruction::BinaryOps)Op, TmpVec, Shuf, "bin.rdx")); | |||
2920 | else | |||
2921 | TmpVec = createMinMaxOp(Builder, RdxDesc.MinMaxKind, TmpVec, Shuf); | |||
2922 | } | |||
2923 | ||||
2924 | // The result is in the first element of the vector. | |||
2925 | ReducedPartRdx = Builder.CreateExtractElement(TmpVec, | |||
2926 | Builder.getInt32(0)); | |||
2927 | } | |||
2928 | ||||
2929 | // Create a phi node that merges control-flow from the backedge-taken check | |||
2930 | // block and the middle block. | |||
2931 | PHINode *BCBlockPhi = PHINode::Create(RdxPhi->getType(), 2, "bc.merge.rdx", | |||
2932 | LoopScalarPreHeader->getTerminator()); | |||
2933 | BCBlockPhi->addIncoming(RdxDesc.StartValue, LoopBypassBlocks[0]); | |||
2934 | BCBlockPhi->addIncoming(ReducedPartRdx, LoopMiddleBlock); | |||
2935 | ||||
2936 | // Now, we need to fix the users of the reduction variable | |||
2937 | // inside and outside of the scalar remainder loop. | |||
2938 | // We know that the loop is in LCSSA form. We need to update the | |||
2939 | // PHI nodes in the exit blocks. | |||
2940 | for (BasicBlock::iterator LEI = LoopExitBlock->begin(), | |||
2941 | LEE = LoopExitBlock->end(); LEI != LEE; ++LEI) { | |||
2942 | PHINode *LCSSAPhi = dyn_cast<PHINode>(LEI); | |||
2943 | if (!LCSSAPhi) break; | |||
2944 | ||||
2945 | // All PHINodes need to have a single entry edge, or two if | |||
2946 | // we already fixed them. | |||
2947 | assert(LCSSAPhi->getNumIncomingValues() < 3 && "Invalid LCSSA PHI")((LCSSAPhi->getNumIncomingValues() < 3 && "Invalid LCSSA PHI" ) ? static_cast<void> (0) : __assert_fail ("LCSSAPhi->getNumIncomingValues() < 3 && \"Invalid LCSSA PHI\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2947, __PRETTY_FUNCTION__)); | |||
2948 | ||||
2949 | // We found our reduction value exit-PHI. Update it with the | |||
2950 | // incoming bypass edge. | |||
2951 | if (LCSSAPhi->getIncomingValue(0) == RdxDesc.LoopExitInstr) { | |||
2952 | // Add an edge coming from the bypass. | |||
2953 | LCSSAPhi->addIncoming(ReducedPartRdx, LoopMiddleBlock); | |||
2954 | break; | |||
2955 | } | |||
2956 | }// end of the LCSSA phi scan. | |||
2957 | ||||
2958 | // Fix the scalar loop reduction variable with the incoming reduction sum | |||
2959 | // from the vector body and from the backedge value. | |||
2960 | int IncomingEdgeBlockIdx = | |||
2961 | (RdxPhi)->getBasicBlockIndex(OrigLoop->getLoopLatch()); | |||
2962 | assert(IncomingEdgeBlockIdx >= 0 && "Invalid block index")((IncomingEdgeBlockIdx >= 0 && "Invalid block index" ) ? static_cast<void> (0) : __assert_fail ("IncomingEdgeBlockIdx >= 0 && \"Invalid block index\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2962, __PRETTY_FUNCTION__)); | |||
2963 | // Pick the other block. | |||
2964 | int SelfEdgeBlockIdx = (IncomingEdgeBlockIdx ? 0 : 1); | |||
2965 | (RdxPhi)->setIncomingValue(SelfEdgeBlockIdx, BCBlockPhi); | |||
2966 | (RdxPhi)->setIncomingValue(IncomingEdgeBlockIdx, RdxDesc.LoopExitInstr); | |||
2967 | }// end of for each redux variable. | |||
2968 | ||||
2969 | fixLCSSAPHIs(); | |||
2970 | ||||
2971 | // Remove redundant induction instructions. | |||
2972 | cse(LoopVectorBody); | |||
2973 | } | |||
2974 | ||||
2975 | void InnerLoopVectorizer::fixLCSSAPHIs() { | |||
2976 | for (BasicBlock::iterator LEI = LoopExitBlock->begin(), | |||
2977 | LEE = LoopExitBlock->end(); LEI != LEE; ++LEI) { | |||
2978 | PHINode *LCSSAPhi = dyn_cast<PHINode>(LEI); | |||
2979 | if (!LCSSAPhi) break; | |||
2980 | if (LCSSAPhi->getNumIncomingValues() == 1) | |||
2981 | LCSSAPhi->addIncoming(UndefValue::get(LCSSAPhi->getType()), | |||
2982 | LoopMiddleBlock); | |||
2983 | } | |||
2984 | } | |||
2985 | ||||
2986 | InnerLoopVectorizer::VectorParts | |||
2987 | InnerLoopVectorizer::createEdgeMask(BasicBlock *Src, BasicBlock *Dst) { | |||
2988 | assert(std::find(pred_begin(Dst), pred_end(Dst), Src) != pred_end(Dst) &&((std::find(pred_begin(Dst), pred_end(Dst), Src) != pred_end( Dst) && "Invalid edge") ? static_cast<void> (0) : __assert_fail ("std::find(pred_begin(Dst), pred_end(Dst), Src) != pred_end(Dst) && \"Invalid edge\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2989, __PRETTY_FUNCTION__)) | |||
2989 | "Invalid edge")((std::find(pred_begin(Dst), pred_end(Dst), Src) != pred_end( Dst) && "Invalid edge") ? static_cast<void> (0) : __assert_fail ("std::find(pred_begin(Dst), pred_end(Dst), Src) != pred_end(Dst) && \"Invalid edge\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2989, __PRETTY_FUNCTION__)); | |||
2990 | ||||
2991 | // Look for cached value. | |||
2992 | std::pair<BasicBlock*, BasicBlock*> Edge(Src, Dst); | |||
2993 | EdgeMaskCache::iterator ECEntryIt = MaskCache.find(Edge); | |||
2994 | if (ECEntryIt != MaskCache.end()) | |||
2995 | return ECEntryIt->second; | |||
2996 | ||||
2997 | VectorParts SrcMask = createBlockInMask(Src); | |||
2998 | ||||
2999 | // The terminator has to be a branch inst! | |||
3000 | BranchInst *BI = dyn_cast<BranchInst>(Src->getTerminator()); | |||
3001 | assert(BI && "Unexpected terminator found")((BI && "Unexpected terminator found") ? static_cast< void> (0) : __assert_fail ("BI && \"Unexpected terminator found\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3001, __PRETTY_FUNCTION__)); | |||
3002 | ||||
3003 | if (BI->isConditional()) { | |||
3004 | VectorParts EdgeMask = getVectorValue(BI->getCondition()); | |||
3005 | ||||
3006 | if (BI->getSuccessor(0) != Dst) | |||
3007 | for (unsigned part = 0; part < UF; ++part) | |||
3008 | EdgeMask[part] = Builder.CreateNot(EdgeMask[part]); | |||
3009 | ||||
3010 | for (unsigned part = 0; part < UF; ++part) | |||
3011 | EdgeMask[part] = Builder.CreateAnd(EdgeMask[part], SrcMask[part]); | |||
3012 | ||||
3013 | MaskCache[Edge] = EdgeMask; | |||
3014 | return EdgeMask; | |||
3015 | } | |||
3016 | ||||
3017 | MaskCache[Edge] = SrcMask; | |||
3018 | return SrcMask; | |||
3019 | } | |||
3020 | ||||
3021 | InnerLoopVectorizer::VectorParts | |||
3022 | InnerLoopVectorizer::createBlockInMask(BasicBlock *BB) { | |||
3023 | assert(OrigLoop->contains(BB) && "Block is not a part of a loop")((OrigLoop->contains(BB) && "Block is not a part of a loop" ) ? static_cast<void> (0) : __assert_fail ("OrigLoop->contains(BB) && \"Block is not a part of a loop\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3023, __PRETTY_FUNCTION__)); | |||
3024 | ||||
3025 | // Loop incoming mask is all-one. | |||
3026 | if (OrigLoop->getHeader() == BB) { | |||
3027 | Value *C = ConstantInt::get(IntegerType::getInt1Ty(BB->getContext()), 1); | |||
3028 | return getVectorValue(C); | |||
3029 | } | |||
3030 | ||||
3031 | // This is the block mask. We OR all incoming edges, and with zero. | |||
3032 | Value *Zero = ConstantInt::get(IntegerType::getInt1Ty(BB->getContext()), 0); | |||
3033 | VectorParts BlockMask = getVectorValue(Zero); | |||
3034 | ||||
3035 | // For each pred: | |||
3036 | for (pred_iterator it = pred_begin(BB), e = pred_end(BB); it != e; ++it) { | |||
3037 | VectorParts EM = createEdgeMask(*it, BB); | |||
3038 | for (unsigned part = 0; part < UF; ++part) | |||
3039 | BlockMask[part] = Builder.CreateOr(BlockMask[part], EM[part]); | |||
3040 | } | |||
3041 | ||||
3042 | return BlockMask; | |||
3043 | } | |||
3044 | ||||
3045 | void InnerLoopVectorizer::widenPHIInstruction(Instruction *PN, | |||
3046 | InnerLoopVectorizer::VectorParts &Entry, | |||
3047 | unsigned UF, unsigned VF, PhiVector *PV) { | |||
3048 | PHINode* P = cast<PHINode>(PN); | |||
3049 | // Handle reduction variables: | |||
3050 | if (Legal->getReductionVars()->count(P)) { | |||
3051 | for (unsigned part = 0; part < UF; ++part) { | |||
3052 | // This is phase one of vectorizing PHIs. | |||
3053 | Type *VecTy = (VF == 1) ? PN->getType() : | |||
3054 | VectorType::get(PN->getType(), VF); | |||
3055 | Entry[part] = PHINode::Create(VecTy, 2, "vec.phi", | |||
3056 | LoopVectorBody.back()-> getFirstInsertionPt()); | |||
3057 | } | |||
3058 | PV->push_back(P); | |||
3059 | return; | |||
3060 | } | |||
3061 | ||||
3062 | setDebugLocFromInst(Builder, P); | |||
3063 | // Check for PHI nodes that are lowered to vector selects. | |||
3064 | if (P->getParent() != OrigLoop->getHeader()) { | |||
3065 | // We know that all PHIs in non-header blocks are converted into | |||
3066 | // selects, so we don't have to worry about the insertion order and we | |||
3067 | // can just use the builder. | |||
3068 | // At this point we generate the predication tree. There may be | |||
3069 | // duplications since this is a simple recursive scan, but future | |||
3070 | // optimizations will clean it up. | |||
3071 | ||||
3072 | unsigned NumIncoming = P->getNumIncomingValues(); | |||
3073 | ||||
3074 | // Generate a sequence of selects of the form: | |||
3075 | // SELECT(Mask3, In3, | |||
3076 | // SELECT(Mask2, In2, | |||
3077 | // ( ...))) | |||
3078 | for (unsigned In = 0; In < NumIncoming; In++) { | |||
3079 | VectorParts Cond = createEdgeMask(P->getIncomingBlock(In), | |||
3080 | P->getParent()); | |||
3081 | VectorParts &In0 = getVectorValue(P->getIncomingValue(In)); | |||
3082 | ||||
3083 | for (unsigned part = 0; part < UF; ++part) { | |||
3084 | // We might have single edge PHIs (blocks) - use an identity | |||
3085 | // 'select' for the first PHI operand. | |||
3086 | if (In == 0) | |||
3087 | Entry[part] = Builder.CreateSelect(Cond[part], In0[part], | |||
3088 | In0[part]); | |||
3089 | else | |||
3090 | // Select between the current value and the previous incoming edge | |||
3091 | // based on the incoming mask. | |||
3092 | Entry[part] = Builder.CreateSelect(Cond[part], In0[part], | |||
3093 | Entry[part], "predphi"); | |||
3094 | } | |||
3095 | } | |||
3096 | return; | |||
3097 | } | |||
3098 | ||||
3099 | // This PHINode must be an induction variable. | |||
3100 | // Make sure that we know about it. | |||
3101 | assert(Legal->getInductionVars()->count(P) &&((Legal->getInductionVars()->count(P) && "Not an induction variable" ) ? static_cast<void> (0) : __assert_fail ("Legal->getInductionVars()->count(P) && \"Not an induction variable\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3102, __PRETTY_FUNCTION__)) | |||
3102 | "Not an induction variable")((Legal->getInductionVars()->count(P) && "Not an induction variable" ) ? static_cast<void> (0) : __assert_fail ("Legal->getInductionVars()->count(P) && \"Not an induction variable\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3102, __PRETTY_FUNCTION__)); | |||
3103 | ||||
3104 | LoopVectorizationLegality::InductionInfo II = | |||
3105 | Legal->getInductionVars()->lookup(P); | |||
3106 | ||||
3107 | switch (II.IK) { | |||
3108 | case LoopVectorizationLegality::IK_NoInduction: | |||
3109 | llvm_unreachable("Unknown induction")::llvm::llvm_unreachable_internal("Unknown induction", "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3109); | |||
3110 | case LoopVectorizationLegality::IK_IntInduction: { | |||
3111 | assert(P->getType() == II.StartValue->getType() && "Types must match")((P->getType() == II.StartValue->getType() && "Types must match" ) ? static_cast<void> (0) : __assert_fail ("P->getType() == II.StartValue->getType() && \"Types must match\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3111, __PRETTY_FUNCTION__)); | |||
3112 | Type *PhiTy = P->getType(); | |||
3113 | Value *Broadcasted; | |||
3114 | if (P == OldInduction) { | |||
3115 | // Handle the canonical induction variable. We might have had to | |||
3116 | // extend the type. | |||
3117 | Broadcasted = Builder.CreateTrunc(Induction, PhiTy); | |||
3118 | } else { | |||
3119 | // Handle other induction variables that are now based on the | |||
3120 | // canonical one. | |||
3121 | Value *NormalizedIdx = Builder.CreateSub(Induction, ExtendedIdx, | |||
3122 | "normalized.idx"); | |||
3123 | NormalizedIdx = Builder.CreateSExtOrTrunc(NormalizedIdx, PhiTy); | |||
3124 | Broadcasted = Builder.CreateAdd(II.StartValue, NormalizedIdx, | |||
3125 | "offset.idx"); | |||
3126 | } | |||
3127 | Broadcasted = getBroadcastInstrs(Broadcasted); | |||
3128 | // After broadcasting the induction variable we need to make the vector | |||
3129 | // consecutive by adding 0, 1, 2, etc. | |||
3130 | for (unsigned part = 0; part < UF; ++part) | |||
3131 | Entry[part] = getConsecutiveVector(Broadcasted, VF * part, false); | |||
3132 | return; | |||
3133 | } | |||
3134 | case LoopVectorizationLegality::IK_ReverseIntInduction: | |||
3135 | case LoopVectorizationLegality::IK_PtrInduction: | |||
3136 | case LoopVectorizationLegality::IK_ReversePtrInduction: | |||
3137 | // Handle reverse integer and pointer inductions. | |||
3138 | Value *StartIdx = ExtendedIdx; | |||
3139 | // This is the normalized GEP that starts counting at zero. | |||
3140 | Value *NormalizedIdx = Builder.CreateSub(Induction, StartIdx, | |||
3141 | "normalized.idx"); | |||
3142 | ||||
3143 | // Handle the reverse integer induction variable case. | |||
3144 | if (LoopVectorizationLegality::IK_ReverseIntInduction == II.IK) { | |||
3145 | IntegerType *DstTy = cast<IntegerType>(II.StartValue->getType()); | |||
3146 | Value *CNI = Builder.CreateSExtOrTrunc(NormalizedIdx, DstTy, | |||
3147 | "resize.norm.idx"); | |||
3148 | Value *ReverseInd = Builder.CreateSub(II.StartValue, CNI, | |||
3149 | "reverse.idx"); | |||
3150 | ||||
3151 | // This is a new value so do not hoist it out. | |||
3152 | Value *Broadcasted = getBroadcastInstrs(ReverseInd); | |||
3153 | // After broadcasting the induction variable we need to make the | |||
3154 | // vector consecutive by adding ... -3, -2, -1, 0. | |||
3155 | for (unsigned part = 0; part < UF; ++part) | |||
3156 | Entry[part] = getConsecutiveVector(Broadcasted, -(int)VF * part, | |||
3157 | true); | |||
3158 | return; | |||
3159 | } | |||
3160 | ||||
3161 | // Handle the pointer induction variable case. | |||
3162 | assert(P->getType()->isPointerTy() && "Unexpected type.")((P->getType()->isPointerTy() && "Unexpected type." ) ? static_cast<void> (0) : __assert_fail ("P->getType()->isPointerTy() && \"Unexpected type.\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3162, __PRETTY_FUNCTION__)); | |||
3163 | ||||
3164 | // Is this a reverse induction ptr or a consecutive induction ptr. | |||
3165 | bool Reverse = (LoopVectorizationLegality::IK_ReversePtrInduction == | |||
3166 | II.IK); | |||
3167 | ||||
3168 | // This is the vector of results. Notice that we don't generate | |||
3169 | // vector geps because scalar geps result in better code. | |||
3170 | for (unsigned part = 0; part < UF; ++part) { | |||
3171 | if (VF == 1) { | |||
3172 | int EltIndex = (part) * (Reverse ? -1 : 1); | |||
3173 | Constant *Idx = ConstantInt::get(Induction->getType(), EltIndex); | |||
3174 | Value *GlobalIdx; | |||
3175 | if (Reverse) | |||
3176 | GlobalIdx = Builder.CreateSub(Idx, NormalizedIdx, "gep.ridx"); | |||
3177 | else | |||
3178 | GlobalIdx = Builder.CreateAdd(NormalizedIdx, Idx, "gep.idx"); | |||
3179 | ||||
3180 | Value *SclrGep = Builder.CreateGEP(II.StartValue, GlobalIdx, | |||
3181 | "next.gep"); | |||
3182 | Entry[part] = SclrGep; | |||
3183 | continue; | |||
3184 | } | |||
3185 | ||||
3186 | Value *VecVal = UndefValue::get(VectorType::get(P->getType(), VF)); | |||
3187 | for (unsigned int i = 0; i < VF; ++i) { | |||
3188 | int EltIndex = (i + part * VF) * (Reverse ? -1 : 1); | |||
3189 | Constant *Idx = ConstantInt::get(Induction->getType(), EltIndex); | |||
3190 | Value *GlobalIdx; | |||
3191 | if (!Reverse) | |||
3192 | GlobalIdx = Builder.CreateAdd(NormalizedIdx, Idx, "gep.idx"); | |||
3193 | else | |||
3194 | GlobalIdx = Builder.CreateSub(Idx, NormalizedIdx, "gep.ridx"); | |||
3195 | ||||
3196 | Value *SclrGep = Builder.CreateGEP(II.StartValue, GlobalIdx, | |||
3197 | "next.gep"); | |||
3198 | VecVal = Builder.CreateInsertElement(VecVal, SclrGep, | |||
3199 | Builder.getInt32(i), | |||
3200 | "insert.gep"); | |||
3201 | } | |||
3202 | Entry[part] = VecVal; | |||
3203 | } | |||
3204 | return; | |||
3205 | } | |||
3206 | } | |||
3207 | ||||
3208 | void InnerLoopVectorizer::vectorizeBlockInLoop(BasicBlock *BB, PhiVector *PV) { | |||
3209 | // For each instruction in the old loop. | |||
3210 | for (BasicBlock::iterator it = BB->begin(), e = BB->end(); it != e; ++it) { | |||
3211 | VectorParts &Entry = WidenMap.get(it); | |||
3212 | switch (it->getOpcode()) { | |||
3213 | case Instruction::Br: | |||
3214 | // Nothing to do for PHIs and BR, since we already took care of the | |||
3215 | // loop control flow instructions. | |||
3216 | continue; | |||
3217 | case Instruction::PHI:{ | |||
3218 | // Vectorize PHINodes. | |||
3219 | widenPHIInstruction(it, Entry, UF, VF, PV); | |||
3220 | continue; | |||
3221 | }// End of PHI. | |||
3222 | ||||
3223 | case Instruction::Add: | |||
3224 | case Instruction::FAdd: | |||
3225 | case Instruction::Sub: | |||
3226 | case Instruction::FSub: | |||
3227 | case Instruction::Mul: | |||
3228 | case Instruction::FMul: | |||
3229 | case Instruction::UDiv: | |||
3230 | case Instruction::SDiv: | |||
3231 | case Instruction::FDiv: | |||
3232 | case Instruction::URem: | |||
3233 | case Instruction::SRem: | |||
3234 | case Instruction::FRem: | |||
3235 | case Instruction::Shl: | |||
3236 | case Instruction::LShr: | |||
3237 | case Instruction::AShr: | |||
3238 | case Instruction::And: | |||
3239 | case Instruction::Or: | |||
3240 | case Instruction::Xor: { | |||
3241 | // Just widen binops. | |||
3242 | BinaryOperator *BinOp = dyn_cast<BinaryOperator>(it); | |||
3243 | setDebugLocFromInst(Builder, BinOp); | |||
3244 | VectorParts &A = getVectorValue(it->getOperand(0)); | |||
3245 | VectorParts &B = getVectorValue(it->getOperand(1)); | |||
3246 | ||||
3247 | // Use this vector value for all users of the original instruction. | |||
3248 | for (unsigned Part = 0; Part < UF; ++Part) { | |||
3249 | Value *V = Builder.CreateBinOp(BinOp->getOpcode(), A[Part], B[Part]); | |||
3250 | ||||
3251 | if (BinaryOperator *VecOp = dyn_cast<BinaryOperator>(V)) | |||
3252 | VecOp->copyIRFlags(BinOp); | |||
3253 | ||||
3254 | Entry[Part] = V; | |||
3255 | } | |||
3256 | ||||
3257 | propagateMetadata(Entry, it); | |||
3258 | break; | |||
3259 | } | |||
3260 | case Instruction::Select: { | |||
3261 | // Widen selects. | |||
3262 | // If the selector is loop invariant we can create a select | |||
3263 | // instruction with a scalar condition. Otherwise, use vector-select. | |||
3264 | bool InvariantCond = SE->isLoopInvariant(SE->getSCEV(it->getOperand(0)), | |||
3265 | OrigLoop); | |||
3266 | setDebugLocFromInst(Builder, it); | |||
3267 | ||||
3268 | // The condition can be loop invariant but still defined inside the | |||
3269 | // loop. This means that we can't just use the original 'cond' value. | |||
3270 | // We have to take the 'vectorized' value and pick the first lane. | |||
3271 | // Instcombine will make this a no-op. | |||
3272 | VectorParts &Cond = getVectorValue(it->getOperand(0)); | |||
3273 | VectorParts &Op0 = getVectorValue(it->getOperand(1)); | |||
3274 | VectorParts &Op1 = getVectorValue(it->getOperand(2)); | |||
3275 | ||||
3276 | Value *ScalarCond = (VF == 1) ? Cond[0] : | |||
3277 | Builder.CreateExtractElement(Cond[0], Builder.getInt32(0)); | |||
3278 | ||||
3279 | for (unsigned Part = 0; Part < UF; ++Part) { | |||
3280 | Entry[Part] = Builder.CreateSelect( | |||
3281 | InvariantCond ? ScalarCond : Cond[Part], | |||
3282 | Op0[Part], | |||
3283 | Op1[Part]); | |||
3284 | } | |||
3285 | ||||
3286 | propagateMetadata(Entry, it); | |||
3287 | break; | |||
3288 | } | |||
3289 | ||||
3290 | case Instruction::ICmp: | |||
3291 | case Instruction::FCmp: { | |||
3292 | // Widen compares. Generate vector compares. | |||
3293 | bool FCmp = (it->getOpcode() == Instruction::FCmp); | |||
3294 | CmpInst *Cmp = dyn_cast<CmpInst>(it); | |||
3295 | setDebugLocFromInst(Builder, it); | |||
3296 | VectorParts &A = getVectorValue(it->getOperand(0)); | |||
3297 | VectorParts &B = getVectorValue(it->getOperand(1)); | |||
3298 | for (unsigned Part = 0; Part < UF; ++Part) { | |||
3299 | Value *C = nullptr; | |||
3300 | if (FCmp) | |||
3301 | C = Builder.CreateFCmp(Cmp->getPredicate(), A[Part], B[Part]); | |||
3302 | else | |||
3303 | C = Builder.CreateICmp(Cmp->getPredicate(), A[Part], B[Part]); | |||
3304 | Entry[Part] = C; | |||
3305 | } | |||
3306 | ||||
3307 | propagateMetadata(Entry, it); | |||
3308 | break; | |||
3309 | } | |||
3310 | ||||
3311 | case Instruction::Store: | |||
3312 | case Instruction::Load: | |||
3313 | vectorizeMemoryInstruction(it); | |||
3314 | break; | |||
3315 | case Instruction::ZExt: | |||
3316 | case Instruction::SExt: | |||
3317 | case Instruction::FPToUI: | |||
3318 | case Instruction::FPToSI: | |||
3319 | case Instruction::FPExt: | |||
3320 | case Instruction::PtrToInt: | |||
3321 | case Instruction::IntToPtr: | |||
3322 | case Instruction::SIToFP: | |||
3323 | case Instruction::UIToFP: | |||
3324 | case Instruction::Trunc: | |||
3325 | case Instruction::FPTrunc: | |||
3326 | case Instruction::BitCast: { | |||
3327 | CastInst *CI = dyn_cast<CastInst>(it); | |||
3328 | setDebugLocFromInst(Builder, it); | |||
3329 | /// Optimize the special case where the source is the induction | |||
3330 | /// variable. Notice that we can only optimize the 'trunc' case | |||
3331 | /// because: a. FP conversions lose precision, b. sext/zext may wrap, | |||
3332 | /// c. other casts depend on pointer size. | |||
3333 | if (CI->getOperand(0) == OldInduction && | |||
3334 | it->getOpcode() == Instruction::Trunc) { | |||
3335 | Value *ScalarCast = Builder.CreateCast(CI->getOpcode(), Induction, | |||
3336 | CI->getType()); | |||
3337 | Value *Broadcasted = getBroadcastInstrs(ScalarCast); | |||
3338 | for (unsigned Part = 0; Part < UF; ++Part) | |||
3339 | Entry[Part] = getConsecutiveVector(Broadcasted, VF * Part, false); | |||
3340 | propagateMetadata(Entry, it); | |||
3341 | break; | |||
3342 | } | |||
3343 | /// Vectorize casts. | |||
3344 | Type *DestTy = (VF == 1) ? CI->getType() : | |||
3345 | VectorType::get(CI->getType(), VF); | |||
3346 | ||||
3347 | VectorParts &A = getVectorValue(it->getOperand(0)); | |||
3348 | for (unsigned Part = 0; Part < UF; ++Part) | |||
3349 | Entry[Part] = Builder.CreateCast(CI->getOpcode(), A[Part], DestTy); | |||
3350 | propagateMetadata(Entry, it); | |||
3351 | break; | |||
3352 | } | |||
3353 | ||||
3354 | case Instruction::Call: { | |||
3355 | // Ignore dbg intrinsics. | |||
3356 | if (isa<DbgInfoIntrinsic>(it)) | |||
3357 | break; | |||
3358 | setDebugLocFromInst(Builder, it); | |||
3359 | ||||
3360 | Module *M = BB->getParent()->getParent(); | |||
3361 | CallInst *CI = cast<CallInst>(it); | |||
3362 | Intrinsic::ID ID = getIntrinsicIDForCall(CI, TLI); | |||
3363 | assert(ID && "Not an intrinsic call!")((ID && "Not an intrinsic call!") ? static_cast<void > (0) : __assert_fail ("ID && \"Not an intrinsic call!\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3363, __PRETTY_FUNCTION__)); | |||
3364 | switch (ID) { | |||
3365 | case Intrinsic::lifetime_end: | |||
3366 | case Intrinsic::lifetime_start: | |||
3367 | scalarizeInstruction(it); | |||
3368 | break; | |||
3369 | default: | |||
3370 | bool HasScalarOpd = hasVectorInstrinsicScalarOpd(ID, 1); | |||
3371 | for (unsigned Part = 0; Part < UF; ++Part) { | |||
3372 | SmallVector<Value *, 4> Args; | |||
3373 | for (unsigned i = 0, ie = CI->getNumArgOperands(); i != ie; ++i) { | |||
3374 | if (HasScalarOpd && i == 1) { | |||
3375 | Args.push_back(CI->getArgOperand(i)); | |||
3376 | continue; | |||
3377 | } | |||
3378 | VectorParts &Arg = getVectorValue(CI->getArgOperand(i)); | |||
3379 | Args.push_back(Arg[Part]); | |||
3380 | } | |||
3381 | Type *Tys[] = {CI->getType()}; | |||
3382 | if (VF > 1) | |||
3383 | Tys[0] = VectorType::get(CI->getType()->getScalarType(), VF); | |||
3384 | ||||
3385 | Function *F = Intrinsic::getDeclaration(M, ID, Tys); | |||
3386 | Entry[Part] = Builder.CreateCall(F, Args); | |||
3387 | } | |||
3388 | ||||
3389 | propagateMetadata(Entry, it); | |||
3390 | break; | |||
3391 | } | |||
3392 | break; | |||
3393 | } | |||
3394 | ||||
3395 | default: | |||
3396 | // All other instructions are unsupported. Scalarize them. | |||
3397 | scalarizeInstruction(it); | |||
3398 | break; | |||
3399 | }// end of switch. | |||
3400 | }// end of for_each instr. | |||
3401 | } | |||
3402 | ||||
3403 | void InnerLoopVectorizer::updateAnalysis() { | |||
3404 | // Forget the original basic block. | |||
3405 | SE->forgetLoop(OrigLoop); | |||
3406 | ||||
3407 | // Update the dominator tree information. | |||
3408 | assert(DT->properlyDominates(LoopBypassBlocks.front(), LoopExitBlock) &&((DT->properlyDominates(LoopBypassBlocks.front(), LoopExitBlock ) && "Entry does not dominate exit.") ? static_cast< void> (0) : __assert_fail ("DT->properlyDominates(LoopBypassBlocks.front(), LoopExitBlock) && \"Entry does not dominate exit.\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3409, __PRETTY_FUNCTION__)) | |||
3409 | "Entry does not dominate exit.")((DT->properlyDominates(LoopBypassBlocks.front(), LoopExitBlock ) && "Entry does not dominate exit.") ? static_cast< void> (0) : __assert_fail ("DT->properlyDominates(LoopBypassBlocks.front(), LoopExitBlock) && \"Entry does not dominate exit.\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3409, __PRETTY_FUNCTION__)); | |||
3410 | ||||
3411 | for (unsigned I = 1, E = LoopBypassBlocks.size(); I != E; ++I) | |||
3412 | DT->addNewBlock(LoopBypassBlocks[I], LoopBypassBlocks[I-1]); | |||
3413 | DT->addNewBlock(LoopVectorPreHeader, LoopBypassBlocks.back()); | |||
3414 | ||||
3415 | // Due to if predication of stores we might create a sequence of "if(pred) | |||
3416 | // a[i] = ...; " blocks. | |||
3417 | for (unsigned i = 0, e = LoopVectorBody.size(); i != e; ++i) { | |||
3418 | if (i == 0) | |||
3419 | DT->addNewBlock(LoopVectorBody[0], LoopVectorPreHeader); | |||
3420 | else if (isPredicatedBlock(i)) { | |||
3421 | DT->addNewBlock(LoopVectorBody[i], LoopVectorBody[i-1]); | |||
3422 | } else { | |||
3423 | DT->addNewBlock(LoopVectorBody[i], LoopVectorBody[i-2]); | |||
3424 | } | |||
3425 | } | |||
3426 | ||||
3427 | DT->addNewBlock(LoopMiddleBlock, LoopBypassBlocks[1]); | |||
3428 | DT->addNewBlock(LoopScalarPreHeader, LoopBypassBlocks[0]); | |||
3429 | DT->changeImmediateDominator(LoopScalarBody, LoopScalarPreHeader); | |||
3430 | DT->changeImmediateDominator(LoopExitBlock, LoopMiddleBlock); | |||
3431 | ||||
3432 | DEBUG(DT->verifyDomTree())do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { DT->verifyDomTree(); } } while (0); | |||
3433 | } | |||
3434 | ||||
3435 | /// \brief Check whether it is safe to if-convert this phi node. | |||
3436 | /// | |||
3437 | /// Phi nodes with constant expressions that can trap are not safe to if | |||
3438 | /// convert. | |||
3439 | static bool canIfConvertPHINodes(BasicBlock *BB) { | |||
3440 | for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) { | |||
3441 | PHINode *Phi = dyn_cast<PHINode>(I); | |||
3442 | if (!Phi) | |||
3443 | return true; | |||
3444 | for (unsigned p = 0, e = Phi->getNumIncomingValues(); p != e; ++p) | |||
3445 | if (Constant *C = dyn_cast<Constant>(Phi->getIncomingValue(p))) | |||
3446 | if (C->canTrap()) | |||
3447 | return false; | |||
3448 | } | |||
3449 | return true; | |||
3450 | } | |||
3451 | ||||
3452 | bool LoopVectorizationLegality::canVectorizeWithIfConvert() { | |||
3453 | if (!EnableIfConversion) { | |||
3454 | emitAnalysis(Report() << "if-conversion is disabled"); | |||
3455 | return false; | |||
3456 | } | |||
3457 | ||||
3458 | assert(TheLoop->getNumBlocks() > 1 && "Single block loops are vectorizable")((TheLoop->getNumBlocks() > 1 && "Single block loops are vectorizable" ) ? static_cast<void> (0) : __assert_fail ("TheLoop->getNumBlocks() > 1 && \"Single block loops are vectorizable\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3458, __PRETTY_FUNCTION__)); | |||
3459 | ||||
3460 | // A list of pointers that we can safely read and write to. | |||
3461 | SmallPtrSet<Value *, 8> SafePointes; | |||
3462 | ||||
3463 | // Collect safe addresses. | |||
3464 | for (Loop::block_iterator BI = TheLoop->block_begin(), | |||
3465 | BE = TheLoop->block_end(); BI != BE; ++BI) { | |||
3466 | BasicBlock *BB = *BI; | |||
3467 | ||||
3468 | if (blockNeedsPredication(BB)) | |||
3469 | continue; | |||
3470 | ||||
3471 | for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) { | |||
3472 | if (LoadInst *LI = dyn_cast<LoadInst>(I)) | |||
3473 | SafePointes.insert(LI->getPointerOperand()); | |||
3474 | else if (StoreInst *SI = dyn_cast<StoreInst>(I)) | |||
3475 | SafePointes.insert(SI->getPointerOperand()); | |||
3476 | } | |||
3477 | } | |||
3478 | ||||
3479 | // Collect the blocks that need predication. | |||
3480 | BasicBlock *Header = TheLoop->getHeader(); | |||
3481 | for (Loop::block_iterator BI = TheLoop->block_begin(), | |||
3482 | BE = TheLoop->block_end(); BI != BE; ++BI) { | |||
3483 | BasicBlock *BB = *BI; | |||
3484 | ||||
3485 | // We don't support switch statements inside loops. | |||
3486 | if (!isa<BranchInst>(BB->getTerminator())) { | |||
3487 | emitAnalysis(Report(BB->getTerminator()) | |||
3488 | << "loop contains a switch statement"); | |||
3489 | return false; | |||
3490 | } | |||
3491 | ||||
3492 | // We must be able to predicate all blocks that need to be predicated. | |||
3493 | if (blockNeedsPredication(BB)) { | |||
3494 | if (!blockCanBePredicated(BB, SafePointes)) { | |||
3495 | emitAnalysis(Report(BB->getTerminator()) | |||
3496 | << "control flow cannot be substituted for a select"); | |||
3497 | return false; | |||
3498 | } | |||
3499 | } else if (BB != Header && !canIfConvertPHINodes(BB)) { | |||
3500 | emitAnalysis(Report(BB->getTerminator()) | |||
3501 | << "control flow cannot be substituted for a select"); | |||
3502 | return false; | |||
3503 | } | |||
3504 | } | |||
3505 | ||||
3506 | // We can if-convert this loop. | |||
3507 | return true; | |||
3508 | } | |||
3509 | ||||
3510 | bool LoopVectorizationLegality::canVectorize() { | |||
3511 | // We must have a loop in canonical form. Loops with indirectbr in them cannot | |||
3512 | // be canonicalized. | |||
3513 | if (!TheLoop->getLoopPreheader()) { | |||
3514 | emitAnalysis( | |||
3515 | Report() << "loop control flow is not understood by vectorizer"); | |||
3516 | return false; | |||
3517 | } | |||
3518 | ||||
3519 | // We can only vectorize innermost loops. | |||
3520 | if (TheLoop->getSubLoopsVector().size()) { | |||
3521 | emitAnalysis(Report() << "loop is not the innermost loop"); | |||
3522 | return false; | |||
3523 | } | |||
3524 | ||||
3525 | // We must have a single backedge. | |||
3526 | if (TheLoop->getNumBackEdges() != 1) { | |||
3527 | emitAnalysis( | |||
3528 | Report() << "loop control flow is not understood by vectorizer"); | |||
3529 | return false; | |||
3530 | } | |||
3531 | ||||
3532 | // We must have a single exiting block. | |||
3533 | if (!TheLoop->getExitingBlock()) { | |||
3534 | emitAnalysis( | |||
3535 | Report() << "loop control flow is not understood by vectorizer"); | |||
3536 | return false; | |||
3537 | } | |||
3538 | ||||
3539 | // We need to have a loop header. | |||
3540 | DEBUG(dbgs() << "LV: Found a loop: " <<do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found a loop: " << TheLoop->getHeader()->getName() << '\n'; } } while (0) | |||
3541 | TheLoop->getHeader()->getName() << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found a loop: " << TheLoop->getHeader()->getName() << '\n'; } } while (0); | |||
3542 | ||||
3543 | // Check if we can if-convert non-single-bb loops. | |||
3544 | unsigned NumBlocks = TheLoop->getNumBlocks(); | |||
3545 | if (NumBlocks != 1 && !canVectorizeWithIfConvert()) { | |||
3546 | DEBUG(dbgs() << "LV: Can't if-convert the loop.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Can't if-convert the loop.\n" ; } } while (0); | |||
3547 | return false; | |||
3548 | } | |||
3549 | ||||
3550 | // ScalarEvolution needs to be able to find the exit count. | |||
3551 | const SCEV *ExitCount = SE->getBackedgeTakenCount(TheLoop); | |||
3552 | if (ExitCount == SE->getCouldNotCompute()) { | |||
3553 | emitAnalysis(Report() << "could not determine number of loop iterations"); | |||
3554 | DEBUG(dbgs() << "LV: SCEV could not compute the loop exit count.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: SCEV could not compute the loop exit count.\n" ; } } while (0); | |||
3555 | return false; | |||
3556 | } | |||
3557 | ||||
3558 | // Check if we can vectorize the instructions and CFG in this loop. | |||
3559 | if (!canVectorizeInstrs()) { | |||
3560 | DEBUG(dbgs() << "LV: Can't vectorize the instructions or CFG\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Can't vectorize the instructions or CFG\n" ; } } while (0); | |||
3561 | return false; | |||
3562 | } | |||
3563 | ||||
3564 | // Go over each instruction and look at memory deps. | |||
3565 | if (!canVectorizeMemory()) { | |||
3566 | DEBUG(dbgs() << "LV: Can't vectorize due to memory conflicts\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Can't vectorize due to memory conflicts\n" ; } } while (0); | |||
3567 | return false; | |||
3568 | } | |||
3569 | ||||
3570 | // Collect all of the variables that remain uniform after vectorization. | |||
3571 | collectLoopUniforms(); | |||
3572 | ||||
3573 | DEBUG(dbgs() << "LV: We can vectorize this loop" <<do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: We can vectorize this loop" << (PtrRtCheck.Need ? " (with a runtime bound check)" : "") <<"!\n"; } } while (0) | |||
3574 | (PtrRtCheck.Need ? " (with a runtime bound check)" : "")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: We can vectorize this loop" << (PtrRtCheck.Need ? " (with a runtime bound check)" : "") <<"!\n"; } } while (0) | |||
3575 | <<"!\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: We can vectorize this loop" << (PtrRtCheck.Need ? " (with a runtime bound check)" : "") <<"!\n"; } } while (0); | |||
3576 | ||||
3577 | // Okay! We can vectorize. At this point we don't have any other mem analysis | |||
3578 | // which may limit our maximum vectorization factor, so just return true with | |||
3579 | // no restrictions. | |||
3580 | return true; | |||
3581 | } | |||
3582 | ||||
3583 | static Type *convertPointerToIntegerType(const DataLayout &DL, Type *Ty) { | |||
3584 | if (Ty->isPointerTy()) | |||
3585 | return DL.getIntPtrType(Ty); | |||
3586 | ||||
3587 | // It is possible that char's or short's overflow when we ask for the loop's | |||
3588 | // trip count, work around this by changing the type size. | |||
3589 | if (Ty->getScalarSizeInBits() < 32) | |||
3590 | return Type::getInt32Ty(Ty->getContext()); | |||
3591 | ||||
3592 | return Ty; | |||
3593 | } | |||
3594 | ||||
3595 | static Type* getWiderType(const DataLayout &DL, Type *Ty0, Type *Ty1) { | |||
3596 | Ty0 = convertPointerToIntegerType(DL, Ty0); | |||
3597 | Ty1 = convertPointerToIntegerType(DL, Ty1); | |||
3598 | if (Ty0->getScalarSizeInBits() > Ty1->getScalarSizeInBits()) | |||
3599 | return Ty0; | |||
3600 | return Ty1; | |||
3601 | } | |||
3602 | ||||
3603 | /// \brief Check that the instruction has outside loop users and is not an | |||
3604 | /// identified reduction variable. | |||
3605 | static bool hasOutsideLoopUser(const Loop *TheLoop, Instruction *Inst, | |||
3606 | SmallPtrSetImpl<Value *> &Reductions) { | |||
3607 | // Reduction instructions are allowed to have exit users. All other | |||
3608 | // instructions must not have external users. | |||
3609 | if (!Reductions.count(Inst)) | |||
3610 | //Check that all of the users of the loop are inside the BB. | |||
3611 | for (User *U : Inst->users()) { | |||
3612 | Instruction *UI = cast<Instruction>(U); | |||
3613 | // This user may be a reduction exit value. | |||
3614 | if (!TheLoop->contains(UI)) { | |||
3615 | DEBUG(dbgs() << "LV: Found an outside user for : " << *UI << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found an outside user for : " << *UI << '\n'; } } while (0); | |||
3616 | return true; | |||
3617 | } | |||
3618 | } | |||
3619 | return false; | |||
3620 | } | |||
3621 | ||||
3622 | bool LoopVectorizationLegality::canVectorizeInstrs() { | |||
3623 | BasicBlock *PreHeader = TheLoop->getLoopPreheader(); | |||
3624 | BasicBlock *Header = TheLoop->getHeader(); | |||
3625 | ||||
3626 | // Look for the attribute signaling the absence of NaNs. | |||
3627 | Function &F = *Header->getParent(); | |||
3628 | if (F.hasFnAttribute("no-nans-fp-math")) | |||
3629 | HasFunNoNaNAttr = F.getAttributes().getAttribute( | |||
3630 | AttributeSet::FunctionIndex, | |||
3631 | "no-nans-fp-math").getValueAsString() == "true"; | |||
3632 | ||||
3633 | // For each block in the loop. | |||
3634 | for (Loop::block_iterator bb = TheLoop->block_begin(), | |||
3635 | be = TheLoop->block_end(); bb != be; ++bb) { | |||
3636 | ||||
3637 | // Scan the instructions in the block and look for hazards. | |||
3638 | for (BasicBlock::iterator it = (*bb)->begin(), e = (*bb)->end(); it != e; | |||
3639 | ++it) { | |||
3640 | ||||
3641 | if (PHINode *Phi = dyn_cast<PHINode>(it)) { | |||
3642 | Type *PhiTy = Phi->getType(); | |||
3643 | // Check that this PHI type is allowed. | |||
3644 | if (!PhiTy->isIntegerTy() && | |||
3645 | !PhiTy->isFloatingPointTy() && | |||
3646 | !PhiTy->isPointerTy()) { | |||
3647 | emitAnalysis(Report(it) | |||
3648 | << "loop control flow is not understood by vectorizer"); | |||
3649 | DEBUG(dbgs() << "LV: Found an non-int non-pointer PHI.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found an non-int non-pointer PHI.\n" ; } } while (0); | |||
3650 | return false; | |||
3651 | } | |||
3652 | ||||
3653 | // If this PHINode is not in the header block, then we know that we | |||
3654 | // can convert it to select during if-conversion. No need to check if | |||
3655 | // the PHIs in this block are induction or reduction variables. | |||
3656 | if (*bb != Header) { | |||
3657 | // Check that this instruction has no outside users or is an | |||
3658 | // identified reduction value with an outside user. | |||
3659 | if (!hasOutsideLoopUser(TheLoop, it, AllowedExit)) | |||
3660 | continue; | |||
3661 | emitAnalysis(Report(it) << "value could not be identified as " | |||
3662 | "an induction or reduction variable"); | |||
3663 | return false; | |||
3664 | } | |||
3665 | ||||
3666 | // We only allow if-converted PHIs with more than two incoming values. | |||
3667 | if (Phi->getNumIncomingValues() != 2) { | |||
3668 | emitAnalysis(Report(it) | |||
3669 | << "control flow not understood by vectorizer"); | |||
3670 | DEBUG(dbgs() << "LV: Found an invalid PHI.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found an invalid PHI.\n" ; } } while (0); | |||
3671 | return false; | |||
3672 | } | |||
3673 | ||||
3674 | // This is the value coming from the preheader. | |||
3675 | Value *StartValue = Phi->getIncomingValueForBlock(PreHeader); | |||
3676 | // Check if this is an induction variable. | |||
3677 | InductionKind IK = isInductionVariable(Phi); | |||
3678 | ||||
3679 | if (IK_NoInduction != IK) { | |||
3680 | // Get the widest type. | |||
3681 | if (!WidestIndTy) | |||
3682 | WidestIndTy = convertPointerToIntegerType(*DL, PhiTy); | |||
3683 | else | |||
3684 | WidestIndTy = getWiderType(*DL, PhiTy, WidestIndTy); | |||
3685 | ||||
3686 | // Int inductions are special because we only allow one IV. | |||
3687 | if (IK == IK_IntInduction) { | |||
3688 | // Use the phi node with the widest type as induction. Use the last | |||
3689 | // one if there are multiple (no good reason for doing this other | |||
3690 | // than it is expedient). | |||
3691 | if (!Induction || PhiTy == WidestIndTy) | |||
3692 | Induction = Phi; | |||
3693 | } | |||
3694 | ||||
3695 | DEBUG(dbgs() << "LV: Found an induction variable.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found an induction variable.\n" ; } } while (0); | |||
3696 | Inductions[Phi] = InductionInfo(StartValue, IK); | |||
3697 | ||||
3698 | // Until we explicitly handle the case of an induction variable with | |||
3699 | // an outside loop user we have to give up vectorizing this loop. | |||
3700 | if (hasOutsideLoopUser(TheLoop, it, AllowedExit)) { | |||
3701 | emitAnalysis(Report(it) << "use of induction value outside of the " | |||
3702 | "loop is not handled by vectorizer"); | |||
3703 | return false; | |||
3704 | } | |||
3705 | ||||
3706 | continue; | |||
3707 | } | |||
3708 | ||||
3709 | if (AddReductionVar(Phi, RK_IntegerAdd)) { | |||
3710 | DEBUG(dbgs() << "LV: Found an ADD reduction PHI."<< *Phi <<"\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found an ADD reduction PHI." << *Phi <<"\n"; } } while (0); | |||
3711 | continue; | |||
3712 | } | |||
3713 | if (AddReductionVar(Phi, RK_IntegerMult)) { | |||
3714 | DEBUG(dbgs() << "LV: Found a MUL reduction PHI."<< *Phi <<"\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found a MUL reduction PHI." << *Phi <<"\n"; } } while (0); | |||
3715 | continue; | |||
3716 | } | |||
3717 | if (AddReductionVar(Phi, RK_IntegerOr)) { | |||
3718 | DEBUG(dbgs() << "LV: Found an OR reduction PHI."<< *Phi <<"\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found an OR reduction PHI." << *Phi <<"\n"; } } while (0); | |||
3719 | continue; | |||
3720 | } | |||
3721 | if (AddReductionVar(Phi, RK_IntegerAnd)) { | |||
3722 | DEBUG(dbgs() << "LV: Found an AND reduction PHI."<< *Phi <<"\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found an AND reduction PHI." << *Phi <<"\n"; } } while (0); | |||
3723 | continue; | |||
3724 | } | |||
3725 | if (AddReductionVar(Phi, RK_IntegerXor)) { | |||
3726 | DEBUG(dbgs() << "LV: Found a XOR reduction PHI."<< *Phi <<"\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found a XOR reduction PHI." << *Phi <<"\n"; } } while (0); | |||
3727 | continue; | |||
3728 | } | |||
3729 | if (AddReductionVar(Phi, RK_IntegerMinMax)) { | |||
3730 | DEBUG(dbgs() << "LV: Found a MINMAX reduction PHI."<< *Phi <<"\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found a MINMAX reduction PHI." << *Phi <<"\n"; } } while (0); | |||
3731 | continue; | |||
3732 | } | |||
3733 | if (AddReductionVar(Phi, RK_FloatMult)) { | |||
3734 | DEBUG(dbgs() << "LV: Found an FMult reduction PHI."<< *Phi <<"\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found an FMult reduction PHI." << *Phi <<"\n"; } } while (0); | |||
3735 | continue; | |||
3736 | } | |||
3737 | if (AddReductionVar(Phi, RK_FloatAdd)) { | |||
3738 | DEBUG(dbgs() << "LV: Found an FAdd reduction PHI."<< *Phi <<"\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found an FAdd reduction PHI." << *Phi <<"\n"; } } while (0); | |||
3739 | continue; | |||
3740 | } | |||
3741 | if (AddReductionVar(Phi, RK_FloatMinMax)) { | |||
3742 | DEBUG(dbgs() << "LV: Found an float MINMAX reduction PHI."<< *Phi <<do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found an float MINMAX reduction PHI." << *Phi << "\n"; } } while (0) | |||
3743 | "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found an float MINMAX reduction PHI." << *Phi << "\n"; } } while (0); | |||
3744 | continue; | |||
3745 | } | |||
3746 | ||||
3747 | emitAnalysis(Report(it) << "value that could not be identified as " | |||
3748 | "reduction is used outside the loop"); | |||
3749 | DEBUG(dbgs() << "LV: Found an unidentified PHI."<< *Phi <<"\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found an unidentified PHI." << *Phi <<"\n"; } } while (0); | |||
3750 | return false; | |||
3751 | }// end of PHI handling | |||
3752 | ||||
3753 | // We still don't handle functions. However, we can ignore dbg intrinsic | |||
3754 | // calls and we do handle certain intrinsic and libm functions. | |||
3755 | CallInst *CI = dyn_cast<CallInst>(it); | |||
3756 | if (CI && !getIntrinsicIDForCall(CI, TLI) && !isa<DbgInfoIntrinsic>(CI)) { | |||
3757 | emitAnalysis(Report(it) << "call instruction cannot be vectorized"); | |||
3758 | DEBUG(dbgs() << "LV: Found a call site.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found a call site.\n" ; } } while (0); | |||
3759 | return false; | |||
3760 | } | |||
3761 | ||||
3762 | // Intrinsics such as powi,cttz and ctlz are legal to vectorize if the | |||
3763 | // second argument is the same (i.e. loop invariant) | |||
3764 | if (CI && | |||
3765 | hasVectorInstrinsicScalarOpd(getIntrinsicIDForCall(CI, TLI), 1)) { | |||
3766 | if (!SE->isLoopInvariant(SE->getSCEV(CI->getOperand(1)), TheLoop)) { | |||
3767 | emitAnalysis(Report(it) | |||
3768 | << "intrinsic instruction cannot be vectorized"); | |||
3769 | DEBUG(dbgs() << "LV: Found unvectorizable intrinsic " << *CI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found unvectorizable intrinsic " << *CI << "\n"; } } while (0); | |||
3770 | return false; | |||
3771 | } | |||
3772 | } | |||
3773 | ||||
3774 | // Check that the instruction return type is vectorizable. | |||
3775 | // Also, we can't vectorize extractelement instructions. | |||
3776 | if ((!VectorType::isValidElementType(it->getType()) && | |||
3777 | !it->getType()->isVoidTy()) || isa<ExtractElementInst>(it)) { | |||
3778 | emitAnalysis(Report(it) | |||
3779 | << "instruction return type cannot be vectorized"); | |||
3780 | DEBUG(dbgs() << "LV: Found unvectorizable type.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found unvectorizable type.\n" ; } } while (0); | |||
3781 | return false; | |||
3782 | } | |||
3783 | ||||
3784 | // Check that the stored type is vectorizable. | |||
3785 | if (StoreInst *ST = dyn_cast<StoreInst>(it)) { | |||
3786 | Type *T = ST->getValueOperand()->getType(); | |||
3787 | if (!VectorType::isValidElementType(T)) { | |||
3788 | emitAnalysis(Report(ST) << "store instruction cannot be vectorized"); | |||
3789 | return false; | |||
3790 | } | |||
3791 | if (EnableMemAccessVersioning) | |||
3792 | collectStridedAcccess(ST); | |||
3793 | } | |||
3794 | ||||
3795 | if (EnableMemAccessVersioning) | |||
3796 | if (LoadInst *LI = dyn_cast<LoadInst>(it)) | |||
3797 | collectStridedAcccess(LI); | |||
3798 | ||||
3799 | // Reduction instructions are allowed to have exit users. | |||
3800 | // All other instructions must not have external users. | |||
3801 | if (hasOutsideLoopUser(TheLoop, it, AllowedExit)) { | |||
3802 | emitAnalysis(Report(it) << "value cannot be used outside the loop"); | |||
3803 | return false; | |||
3804 | } | |||
3805 | ||||
3806 | } // next instr. | |||
3807 | ||||
3808 | } | |||
3809 | ||||
3810 | if (!Induction) { | |||
3811 | DEBUG(dbgs() << "LV: Did not find one integer induction var.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Did not find one integer induction var.\n" ; } } while (0); | |||
3812 | if (Inductions.empty()) { | |||
3813 | emitAnalysis(Report() | |||
3814 | << "loop induction variable could not be identified"); | |||
3815 | return false; | |||
3816 | } | |||
3817 | } | |||
3818 | ||||
3819 | return true; | |||
3820 | } | |||
3821 | ||||
3822 | ///\brief Remove GEPs whose indices but the last one are loop invariant and | |||
3823 | /// return the induction operand of the gep pointer. | |||
3824 | static Value *stripGetElementPtr(Value *Ptr, ScalarEvolution *SE, | |||
3825 | const DataLayout *DL, Loop *Lp) { | |||
3826 | GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Ptr); | |||
3827 | if (!GEP) | |||
3828 | return Ptr; | |||
3829 | ||||
3830 | unsigned InductionOperand = getGEPInductionOperand(DL, GEP); | |||
3831 | ||||
3832 | // Check that all of the gep indices are uniform except for our induction | |||
3833 | // operand. | |||
3834 | for (unsigned i = 0, e = GEP->getNumOperands(); i != e; ++i) | |||
3835 | if (i != InductionOperand && | |||
3836 | !SE->isLoopInvariant(SE->getSCEV(GEP->getOperand(i)), Lp)) | |||
3837 | return Ptr; | |||
3838 | return GEP->getOperand(InductionOperand); | |||
3839 | } | |||
3840 | ||||
3841 | ///\brief Look for a cast use of the passed value. | |||
3842 | static Value *getUniqueCastUse(Value *Ptr, Loop *Lp, Type *Ty) { | |||
3843 | Value *UniqueCast = nullptr; | |||
3844 | for (User *U : Ptr->users()) { | |||
3845 | CastInst *CI = dyn_cast<CastInst>(U); | |||
3846 | if (CI && CI->getType() == Ty) { | |||
3847 | if (!UniqueCast) | |||
3848 | UniqueCast = CI; | |||
3849 | else | |||
3850 | return nullptr; | |||
3851 | } | |||
3852 | } | |||
3853 | return UniqueCast; | |||
3854 | } | |||
3855 | ||||
3856 | ///\brief Get the stride of a pointer access in a loop. | |||
3857 | /// Looks for symbolic strides "a[i*stride]". Returns the symbolic stride as a | |||
3858 | /// pointer to the Value, or null otherwise. | |||
3859 | static Value *getStrideFromPointer(Value *Ptr, ScalarEvolution *SE, | |||
3860 | const DataLayout *DL, Loop *Lp) { | |||
3861 | const PointerType *PtrTy = dyn_cast<PointerType>(Ptr->getType()); | |||
3862 | if (!PtrTy || PtrTy->isAggregateType()) | |||
3863 | return nullptr; | |||
3864 | ||||
3865 | // Try to remove a gep instruction to make the pointer (actually index at this | |||
3866 | // point) easier analyzable. If OrigPtr is equal to Ptr we are analzying the | |||
3867 | // pointer, otherwise, we are analyzing the index. | |||
3868 | Value *OrigPtr = Ptr; | |||
3869 | ||||
3870 | // The size of the pointer access. | |||
3871 | int64_t PtrAccessSize = 1; | |||
3872 | ||||
3873 | Ptr = stripGetElementPtr(Ptr, SE, DL, Lp); | |||
3874 | const SCEV *V = SE->getSCEV(Ptr); | |||
3875 | ||||
3876 | if (Ptr != OrigPtr) | |||
3877 | // Strip off casts. | |||
3878 | while (const SCEVCastExpr *C = dyn_cast<SCEVCastExpr>(V)) | |||
3879 | V = C->getOperand(); | |||
3880 | ||||
3881 | const SCEVAddRecExpr *S = dyn_cast<SCEVAddRecExpr>(V); | |||
3882 | if (!S) | |||
3883 | return nullptr; | |||
3884 | ||||
3885 | V = S->getStepRecurrence(*SE); | |||
3886 | if (!V) | |||
3887 | return nullptr; | |||
3888 | ||||
3889 | // Strip off the size of access multiplication if we are still analyzing the | |||
3890 | // pointer. | |||
3891 | if (OrigPtr == Ptr) { | |||
3892 | DL->getTypeAllocSize(PtrTy->getElementType()); | |||
3893 | if (const SCEVMulExpr *M = dyn_cast<SCEVMulExpr>(V)) { | |||
3894 | if (M->getOperand(0)->getSCEVType() != scConstant) | |||
3895 | return nullptr; | |||
3896 | ||||
3897 | const APInt &APStepVal = | |||
3898 | cast<SCEVConstant>(M->getOperand(0))->getValue()->getValue(); | |||
3899 | ||||
3900 | // Huge step value - give up. | |||
3901 | if (APStepVal.getBitWidth() > 64) | |||
3902 | return nullptr; | |||
3903 | ||||
3904 | int64_t StepVal = APStepVal.getSExtValue(); | |||
3905 | if (PtrAccessSize != StepVal) | |||
3906 | return nullptr; | |||
3907 | V = M->getOperand(1); | |||
3908 | } | |||
3909 | } | |||
3910 | ||||
3911 | // Strip off casts. | |||
3912 | Type *StripedOffRecurrenceCast = nullptr; | |||
3913 | if (const SCEVCastExpr *C = dyn_cast<SCEVCastExpr>(V)) { | |||
3914 | StripedOffRecurrenceCast = C->getType(); | |||
3915 | V = C->getOperand(); | |||
3916 | } | |||
3917 | ||||
3918 | // Look for the loop invariant symbolic value. | |||
3919 | const SCEVUnknown *U = dyn_cast<SCEVUnknown>(V); | |||
3920 | if (!U) | |||
3921 | return nullptr; | |||
3922 | ||||
3923 | Value *Stride = U->getValue(); | |||
3924 | if (!Lp->isLoopInvariant(Stride)) | |||
3925 | return nullptr; | |||
3926 | ||||
3927 | // If we have stripped off the recurrence cast we have to make sure that we | |||
3928 | // return the value that is used in this loop so that we can replace it later. | |||
3929 | if (StripedOffRecurrenceCast) | |||
3930 | Stride = getUniqueCastUse(Stride, Lp, StripedOffRecurrenceCast); | |||
3931 | ||||
3932 | return Stride; | |||
3933 | } | |||
3934 | ||||
3935 | void LoopVectorizationLegality::collectStridedAcccess(Value *MemAccess) { | |||
3936 | Value *Ptr = nullptr; | |||
3937 | if (LoadInst *LI = dyn_cast<LoadInst>(MemAccess)) | |||
3938 | Ptr = LI->getPointerOperand(); | |||
3939 | else if (StoreInst *SI = dyn_cast<StoreInst>(MemAccess)) | |||
3940 | Ptr = SI->getPointerOperand(); | |||
3941 | else | |||
3942 | return; | |||
3943 | ||||
3944 | Value *Stride = getStrideFromPointer(Ptr, SE, DL, TheLoop); | |||
3945 | if (!Stride) | |||
3946 | return; | |||
3947 | ||||
3948 | DEBUG(dbgs() << "LV: Found a strided access that we can version")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found a strided access that we can version" ; } } while (0); | |||
3949 | DEBUG(dbgs() << " Ptr: " << *Ptr << " Stride: " << *Stride << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << " Ptr: " << *Ptr << " Stride: " << *Stride << "\n"; } } while (0); | |||
3950 | Strides[Ptr] = Stride; | |||
3951 | StrideSet.insert(Stride); | |||
3952 | } | |||
3953 | ||||
3954 | void LoopVectorizationLegality::collectLoopUniforms() { | |||
3955 | // We now know that the loop is vectorizable! | |||
3956 | // Collect variables that will remain uniform after vectorization. | |||
3957 | std::vector<Value*> Worklist; | |||
3958 | BasicBlock *Latch = TheLoop->getLoopLatch(); | |||
3959 | ||||
3960 | // Start with the conditional branch and walk up the block. | |||
3961 | Worklist.push_back(Latch->getTerminator()->getOperand(0)); | |||
3962 | ||||
3963 | // Also add all consecutive pointer values; these values will be uniform | |||
3964 | // after vectorization (and subsequent cleanup) and, until revectorization is | |||
3965 | // supported, all dependencies must also be uniform. | |||
3966 | for (Loop::block_iterator B = TheLoop->block_begin(), | |||
3967 | BE = TheLoop->block_end(); B != BE; ++B) | |||
3968 | for (BasicBlock::iterator I = (*B)->begin(), IE = (*B)->end(); | |||
3969 | I != IE; ++I) | |||
3970 | if (I->getType()->isPointerTy() && isConsecutivePtr(I)) | |||
3971 | Worklist.insert(Worklist.end(), I->op_begin(), I->op_end()); | |||
3972 | ||||
3973 | while (Worklist.size()) { | |||
3974 | Instruction *I = dyn_cast<Instruction>(Worklist.back()); | |||
3975 | Worklist.pop_back(); | |||
3976 | ||||
3977 | // Look at instructions inside this loop. | |||
3978 | // Stop when reaching PHI nodes. | |||
3979 | // TODO: we need to follow values all over the loop, not only in this block. | |||
3980 | if (!I || !TheLoop->contains(I) || isa<PHINode>(I)) | |||
3981 | continue; | |||
3982 | ||||
3983 | // This is a known uniform. | |||
3984 | Uniforms.insert(I); | |||
3985 | ||||
3986 | // Insert all operands. | |||
3987 | Worklist.insert(Worklist.end(), I->op_begin(), I->op_end()); | |||
3988 | } | |||
3989 | } | |||
3990 | ||||
3991 | namespace { | |||
3992 | /// \brief Analyses memory accesses in a loop. | |||
3993 | /// | |||
3994 | /// Checks whether run time pointer checks are needed and builds sets for data | |||
3995 | /// dependence checking. | |||
3996 | class AccessAnalysis { | |||
3997 | public: | |||
3998 | /// \brief Read or write access location. | |||
3999 | typedef PointerIntPair<Value *, 1, bool> MemAccessInfo; | |||
4000 | typedef SmallPtrSet<MemAccessInfo, 8> MemAccessInfoSet; | |||
4001 | ||||
4002 | /// \brief Set of potential dependent memory accesses. | |||
4003 | typedef EquivalenceClasses<MemAccessInfo> DepCandidates; | |||
4004 | ||||
4005 | AccessAnalysis(const DataLayout *Dl, AliasAnalysis *AA, DepCandidates &DA) : | |||
4006 | DL(Dl), AST(*AA), DepCands(DA), IsRTCheckNeeded(false) {} | |||
4007 | ||||
4008 | /// \brief Register a load and whether it is only read from. | |||
4009 | void addLoad(AliasAnalysis::Location &Loc, bool IsReadOnly) { | |||
4010 | Value *Ptr = const_cast<Value*>(Loc.Ptr); | |||
4011 | AST.add(Ptr, AliasAnalysis::UnknownSize, Loc.AATags); | |||
4012 | Accesses.insert(MemAccessInfo(Ptr, false)); | |||
4013 | if (IsReadOnly) | |||
4014 | ReadOnlyPtr.insert(Ptr); | |||
4015 | } | |||
4016 | ||||
4017 | /// \brief Register a store. | |||
4018 | void addStore(AliasAnalysis::Location &Loc) { | |||
4019 | Value *Ptr = const_cast<Value*>(Loc.Ptr); | |||
4020 | AST.add(Ptr, AliasAnalysis::UnknownSize, Loc.AATags); | |||
4021 | Accesses.insert(MemAccessInfo(Ptr, true)); | |||
4022 | } | |||
4023 | ||||
4024 | /// \brief Check whether we can check the pointers at runtime for | |||
4025 | /// non-intersection. | |||
4026 | bool canCheckPtrAtRT(LoopVectorizationLegality::RuntimePointerCheck &RtCheck, | |||
4027 | unsigned &NumComparisons, ScalarEvolution *SE, | |||
4028 | Loop *TheLoop, ValueToValueMap &Strides, | |||
4029 | bool ShouldCheckStride = false); | |||
4030 | ||||
4031 | /// \brief Goes over all memory accesses, checks whether a RT check is needed | |||
4032 | /// and builds sets of dependent accesses. | |||
4033 | void buildDependenceSets() { | |||
4034 | processMemAccesses(); | |||
4035 | } | |||
4036 | ||||
4037 | bool isRTCheckNeeded() { return IsRTCheckNeeded; } | |||
4038 | ||||
4039 | bool isDependencyCheckNeeded() { return !CheckDeps.empty(); } | |||
4040 | void resetDepChecks() { CheckDeps.clear(); } | |||
4041 | ||||
4042 | MemAccessInfoSet &getDependenciesToCheck() { return CheckDeps; } | |||
4043 | ||||
4044 | private: | |||
4045 | typedef SetVector<MemAccessInfo> PtrAccessSet; | |||
4046 | ||||
4047 | /// \brief Go over all memory access and check whether runtime pointer checks | |||
4048 | /// are needed /// and build sets of dependency check candidates. | |||
4049 | void processMemAccesses(); | |||
4050 | ||||
4051 | /// Set of all accesses. | |||
4052 | PtrAccessSet Accesses; | |||
4053 | ||||
4054 | /// Set of accesses that need a further dependence check. | |||
4055 | MemAccessInfoSet CheckDeps; | |||
4056 | ||||
4057 | /// Set of pointers that are read only. | |||
4058 | SmallPtrSet<Value*, 16> ReadOnlyPtr; | |||
4059 | ||||
4060 | const DataLayout *DL; | |||
4061 | ||||
4062 | /// An alias set tracker to partition the access set by underlying object and | |||
4063 | //intrinsic property (such as TBAA metadata). | |||
4064 | AliasSetTracker AST; | |||
4065 | ||||
4066 | /// Sets of potentially dependent accesses - members of one set share an | |||
4067 | /// underlying pointer. The set "CheckDeps" identfies which sets really need a | |||
4068 | /// dependence check. | |||
4069 | DepCandidates &DepCands; | |||
4070 | ||||
4071 | bool IsRTCheckNeeded; | |||
4072 | }; | |||
4073 | ||||
4074 | } // end anonymous namespace | |||
4075 | ||||
4076 | /// \brief Check whether a pointer can participate in a runtime bounds check. | |||
4077 | static bool hasComputableBounds(ScalarEvolution *SE, ValueToValueMap &Strides, | |||
4078 | Value *Ptr) { | |||
4079 | const SCEV *PtrScev = replaceSymbolicStrideSCEV(SE, Strides, Ptr); | |||
4080 | const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(PtrScev); | |||
4081 | if (!AR) | |||
4082 | return false; | |||
4083 | ||||
4084 | return AR->isAffine(); | |||
4085 | } | |||
4086 | ||||
4087 | /// \brief Check the stride of the pointer and ensure that it does not wrap in | |||
4088 | /// the address space. | |||
4089 | static int isStridedPtr(ScalarEvolution *SE, const DataLayout *DL, Value *Ptr, | |||
4090 | const Loop *Lp, ValueToValueMap &StridesMap); | |||
4091 | ||||
4092 | bool AccessAnalysis::canCheckPtrAtRT( | |||
4093 | LoopVectorizationLegality::RuntimePointerCheck &RtCheck, | |||
4094 | unsigned &NumComparisons, ScalarEvolution *SE, Loop *TheLoop, | |||
4095 | ValueToValueMap &StridesMap, bool ShouldCheckStride) { | |||
4096 | // Find pointers with computable bounds. We are going to use this information | |||
4097 | // to place a runtime bound check. | |||
4098 | bool CanDoRT = true; | |||
4099 | ||||
4100 | bool IsDepCheckNeeded = isDependencyCheckNeeded(); | |||
4101 | NumComparisons = 0; | |||
4102 | ||||
4103 | // We assign a consecutive id to access from different alias sets. | |||
4104 | // Accesses between different groups doesn't need to be checked. | |||
4105 | unsigned ASId = 1; | |||
4106 | for (auto &AS : AST) { | |||
4107 | unsigned NumReadPtrChecks = 0; | |||
4108 | unsigned NumWritePtrChecks = 0; | |||
4109 | ||||
4110 | // We assign consecutive id to access from different dependence sets. | |||
4111 | // Accesses within the same set don't need a runtime check. | |||
4112 | unsigned RunningDepId = 1; | |||
4113 | DenseMap<Value *, unsigned> DepSetId; | |||
4114 | ||||
4115 | for (auto A : AS) { | |||
4116 | Value *Ptr = A.getValue(); | |||
4117 | bool IsWrite = Accesses.count(MemAccessInfo(Ptr, true)); | |||
4118 | MemAccessInfo Access(Ptr, IsWrite); | |||
4119 | ||||
4120 | if (IsWrite) | |||
4121 | ++NumWritePtrChecks; | |||
4122 | else | |||
4123 | ++NumReadPtrChecks; | |||
4124 | ||||
4125 | if (hasComputableBounds(SE, StridesMap, Ptr) && | |||
4126 | // When we run after a failing dependency check we have to make sure we | |||
4127 | // don't have wrapping pointers. | |||
4128 | (!ShouldCheckStride || | |||
4129 | isStridedPtr(SE, DL, Ptr, TheLoop, StridesMap) == 1)) { | |||
4130 | // The id of the dependence set. | |||
4131 | unsigned DepId; | |||
4132 | ||||
4133 | if (IsDepCheckNeeded) { | |||
4134 | Value *Leader = DepCands.getLeaderValue(Access).getPointer(); | |||
4135 | unsigned &LeaderId = DepSetId[Leader]; | |||
4136 | if (!LeaderId) | |||
4137 | LeaderId = RunningDepId++; | |||
4138 | DepId = LeaderId; | |||
4139 | } else | |||
4140 | // Each access has its own dependence set. | |||
4141 | DepId = RunningDepId++; | |||
4142 | ||||
4143 | RtCheck.insert(SE, TheLoop, Ptr, IsWrite, DepId, ASId, StridesMap); | |||
4144 | ||||
4145 | DEBUG(dbgs() << "LV: Found a runtime check ptr:" << *Ptr << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found a runtime check ptr:" << *Ptr << '\n'; } } while (0); | |||
4146 | } else { | |||
4147 | CanDoRT = false; | |||
4148 | } | |||
4149 | } | |||
4150 | ||||
4151 | if (IsDepCheckNeeded && CanDoRT && RunningDepId == 2) | |||
4152 | NumComparisons += 0; // Only one dependence set. | |||
4153 | else { | |||
4154 | NumComparisons += (NumWritePtrChecks * (NumReadPtrChecks + | |||
4155 | NumWritePtrChecks - 1)); | |||
4156 | } | |||
4157 | ||||
4158 | ++ASId; | |||
4159 | } | |||
4160 | ||||
4161 | // If the pointers that we would use for the bounds comparison have different | |||
4162 | // address spaces, assume the values aren't directly comparable, so we can't | |||
4163 | // use them for the runtime check. We also have to assume they could | |||
4164 | // overlap. In the future there should be metadata for whether address spaces | |||
4165 | // are disjoint. | |||
4166 | unsigned NumPointers = RtCheck.Pointers.size(); | |||
4167 | for (unsigned i = 0; i < NumPointers; ++i) { | |||
4168 | for (unsigned j = i + 1; j < NumPointers; ++j) { | |||
4169 | // Only need to check pointers between two different dependency sets. | |||
4170 | if (RtCheck.DependencySetId[i] == RtCheck.DependencySetId[j]) | |||
4171 | continue; | |||
4172 | // Only need to check pointers in the same alias set. | |||
4173 | if (RtCheck.AliasSetId[i] != RtCheck.AliasSetId[j]) | |||
4174 | continue; | |||
4175 | ||||
4176 | Value *PtrI = RtCheck.Pointers[i]; | |||
4177 | Value *PtrJ = RtCheck.Pointers[j]; | |||
4178 | ||||
4179 | unsigned ASi = PtrI->getType()->getPointerAddressSpace(); | |||
4180 | unsigned ASj = PtrJ->getType()->getPointerAddressSpace(); | |||
4181 | if (ASi != ASj) { | |||
4182 | DEBUG(dbgs() << "LV: Runtime check would require comparison between"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Runtime check would require comparison between" " different address spaces\n"; } } while (0) | |||
4183 | " different address spaces\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Runtime check would require comparison between" " different address spaces\n"; } } while (0); | |||
4184 | return false; | |||
4185 | } | |||
4186 | } | |||
4187 | } | |||
4188 | ||||
4189 | return CanDoRT; | |||
4190 | } | |||
4191 | ||||
4192 | void AccessAnalysis::processMemAccesses() { | |||
4193 | // We process the set twice: first we process read-write pointers, last we | |||
4194 | // process read-only pointers. This allows us to skip dependence tests for | |||
4195 | // read-only pointers. | |||
4196 | ||||
4197 | DEBUG(dbgs() << "LV: Processing memory accesses...\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Processing memory accesses...\n" ; } } while (0); | |||
4198 | DEBUG(dbgs() << " AST: "; AST.dump())do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << " AST: "; AST.dump(); } } while (0); | |||
4199 | DEBUG(dbgs() << "LV: Accesses:\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Accesses:\n"; } } while (0); | |||
4200 | DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { { for (auto A : Accesses) dbgs() << "\t" << *A.getPointer() << " (" << (A.getInt () ? "write" : (ReadOnlyPtr.count(A.getPointer()) ? "read-only" : "read")) << ")\n"; }; } } while (0) | |||
4201 | for (auto A : Accesses)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { { for (auto A : Accesses) dbgs() << "\t" << *A.getPointer() << " (" << (A.getInt () ? "write" : (ReadOnlyPtr.count(A.getPointer()) ? "read-only" : "read")) << ")\n"; }; } } while (0) | |||
4202 | dbgs() << "\t" << *A.getPointer() << " (" <<do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { { for (auto A : Accesses) dbgs() << "\t" << *A.getPointer() << " (" << (A.getInt () ? "write" : (ReadOnlyPtr.count(A.getPointer()) ? "read-only" : "read")) << ")\n"; }; } } while (0) | |||
4203 | (A.getInt() ? "write" : (ReadOnlyPtr.count(A.getPointer()) ?do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { { for (auto A : Accesses) dbgs() << "\t" << *A.getPointer() << " (" << (A.getInt () ? "write" : (ReadOnlyPtr.count(A.getPointer()) ? "read-only" : "read")) << ")\n"; }; } } while (0) | |||
4204 | "read-only" : "read")) << ")\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { { for (auto A : Accesses) dbgs() << "\t" << *A.getPointer() << " (" << (A.getInt () ? "write" : (ReadOnlyPtr.count(A.getPointer()) ? "read-only" : "read")) << ")\n"; }; } } while (0) | |||
4205 | })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { { for (auto A : Accesses) dbgs() << "\t" << *A.getPointer() << " (" << (A.getInt () ? "write" : (ReadOnlyPtr.count(A.getPointer()) ? "read-only" : "read")) << ")\n"; }; } } while (0); | |||
4206 | ||||
4207 | // The AliasSetTracker has nicely partitioned our pointers by metadata | |||
4208 | // compatibility and potential for underlying-object overlap. As a result, we | |||
4209 | // only need to check for potential pointer dependencies within each alias | |||
4210 | // set. | |||
4211 | for (auto &AS : AST) { | |||
4212 | // Note that both the alias-set tracker and the alias sets themselves used | |||
4213 | // linked lists internally and so the iteration order here is deterministic | |||
4214 | // (matching the original instruction order within each set). | |||
4215 | ||||
4216 | bool SetHasWrite = false; | |||
4217 | ||||
4218 | // Map of pointers to last access encountered. | |||
4219 | typedef DenseMap<Value*, MemAccessInfo> UnderlyingObjToAccessMap; | |||
4220 | UnderlyingObjToAccessMap ObjToLastAccess; | |||
4221 | ||||
4222 | // Set of access to check after all writes have been processed. | |||
4223 | PtrAccessSet DeferredAccesses; | |||
4224 | ||||
4225 | // Iterate over each alias set twice, once to process read/write pointers, | |||
4226 | // and then to process read-only pointers. | |||
4227 | for (int SetIteration = 0; SetIteration < 2; ++SetIteration) { | |||
4228 | bool UseDeferred = SetIteration > 0; | |||
4229 | PtrAccessSet &S = UseDeferred ? DeferredAccesses : Accesses; | |||
4230 | ||||
4231 | for (auto A : AS) { | |||
4232 | Value *Ptr = A.getValue(); | |||
4233 | bool IsWrite = S.count(MemAccessInfo(Ptr, true)); | |||
4234 | ||||
4235 | // If we're using the deferred access set, then it contains only reads. | |||
4236 | bool IsReadOnlyPtr = ReadOnlyPtr.count(Ptr) && !IsWrite; | |||
4237 | if (UseDeferred && !IsReadOnlyPtr) | |||
4238 | continue; | |||
4239 | // Otherwise, the pointer must be in the PtrAccessSet, either as a read | |||
4240 | // or a write. | |||
4241 | assert(((IsReadOnlyPtr && UseDeferred) || IsWrite ||((((IsReadOnlyPtr && UseDeferred) || IsWrite || S.count (MemAccessInfo(Ptr, false))) && "Alias-set pointer not in the access set?" ) ? static_cast<void> (0) : __assert_fail ("((IsReadOnlyPtr && UseDeferred) || IsWrite || S.count(MemAccessInfo(Ptr, false))) && \"Alias-set pointer not in the access set?\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4243, __PRETTY_FUNCTION__)) | |||
4242 | S.count(MemAccessInfo(Ptr, false))) &&((((IsReadOnlyPtr && UseDeferred) || IsWrite || S.count (MemAccessInfo(Ptr, false))) && "Alias-set pointer not in the access set?" ) ? static_cast<void> (0) : __assert_fail ("((IsReadOnlyPtr && UseDeferred) || IsWrite || S.count(MemAccessInfo(Ptr, false))) && \"Alias-set pointer not in the access set?\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4243, __PRETTY_FUNCTION__)) | |||
4243 | "Alias-set pointer not in the access set?")((((IsReadOnlyPtr && UseDeferred) || IsWrite || S.count (MemAccessInfo(Ptr, false))) && "Alias-set pointer not in the access set?" ) ? static_cast<void> (0) : __assert_fail ("((IsReadOnlyPtr && UseDeferred) || IsWrite || S.count(MemAccessInfo(Ptr, false))) && \"Alias-set pointer not in the access set?\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4243, __PRETTY_FUNCTION__)); | |||
4244 | ||||
4245 | MemAccessInfo Access(Ptr, IsWrite); | |||
4246 | DepCands.insert(Access); | |||
4247 | ||||
4248 | // Memorize read-only pointers for later processing and skip them in the | |||
4249 | // first round (they need to be checked after we have seen all write | |||
4250 | // pointers). Note: we also mark pointer that are not consecutive as | |||
4251 | // "read-only" pointers (so that we check "a[b[i]] +="). Hence, we need | |||
4252 | // the second check for "!IsWrite". | |||
4253 | if (!UseDeferred && IsReadOnlyPtr) { | |||
4254 | DeferredAccesses.insert(Access); | |||
4255 | continue; | |||
4256 | } | |||
4257 | ||||
4258 | // If this is a write - check other reads and writes for conflicts. If | |||
4259 | // this is a read only check other writes for conflicts (but only if | |||
4260 | // there is no other write to the ptr - this is an optimization to | |||
4261 | // catch "a[i] = a[i] + " without having to do a dependence check). | |||
4262 | if ((IsWrite || IsReadOnlyPtr) && SetHasWrite) { | |||
4263 | CheckDeps.insert(Access); | |||
4264 | IsRTCheckNeeded = true; | |||
4265 | } | |||
4266 | ||||
4267 | if (IsWrite) | |||
4268 | SetHasWrite = true; | |||
4269 | ||||
4270 | // Create sets of pointers connected by a shared alias set and | |||
4271 | // underlying object. | |||
4272 | typedef SmallVector<Value*, 16> ValueVector; | |||
4273 | ValueVector TempObjects; | |||
4274 | GetUnderlyingObjects(Ptr, TempObjects, DL); | |||
4275 | for (Value *UnderlyingObj : TempObjects) { | |||
4276 | UnderlyingObjToAccessMap::iterator Prev = | |||
4277 | ObjToLastAccess.find(UnderlyingObj); | |||
4278 | if (Prev != ObjToLastAccess.end()) | |||
4279 | DepCands.unionSets(Access, Prev->second); | |||
4280 | ||||
4281 | ObjToLastAccess[UnderlyingObj] = Access; | |||
4282 | } | |||
4283 | } | |||
4284 | } | |||
4285 | } | |||
4286 | } | |||
4287 | ||||
4288 | namespace { | |||
4289 | /// \brief Checks memory dependences among accesses to the same underlying | |||
4290 | /// object to determine whether there vectorization is legal or not (and at | |||
4291 | /// which vectorization factor). | |||
4292 | /// | |||
4293 | /// This class works under the assumption that we already checked that memory | |||
4294 | /// locations with different underlying pointers are "must-not alias". | |||
4295 | /// We use the ScalarEvolution framework to symbolically evalutate access | |||
4296 | /// functions pairs. Since we currently don't restructure the loop we can rely | |||
4297 | /// on the program order of memory accesses to determine their safety. | |||
4298 | /// At the moment we will only deem accesses as safe for: | |||
4299 | /// * A negative constant distance assuming program order. | |||
4300 | /// | |||
4301 | /// Safe: tmp = a[i + 1]; OR a[i + 1] = x; | |||
4302 | /// a[i] = tmp; y = a[i]; | |||
4303 | /// | |||
4304 | /// The latter case is safe because later checks guarantuee that there can't | |||
4305 | /// be a cycle through a phi node (that is, we check that "x" and "y" is not | |||
4306 | /// the same variable: a header phi can only be an induction or a reduction, a | |||
4307 | /// reduction can't have a memory sink, an induction can't have a memory | |||
4308 | /// source). This is important and must not be violated (or we have to | |||
4309 | /// resort to checking for cycles through memory). | |||
4310 | /// | |||
4311 | /// * A positive constant distance assuming program order that is bigger | |||
4312 | /// than the biggest memory access. | |||
4313 | /// | |||
4314 | /// tmp = a[i] OR b[i] = x | |||
4315 | /// a[i+2] = tmp y = b[i+2]; | |||
4316 | /// | |||
4317 | /// Safe distance: 2 x sizeof(a[0]), and 2 x sizeof(b[0]), respectively. | |||
4318 | /// | |||
4319 | /// * Zero distances and all accesses have the same size. | |||
4320 | /// | |||
4321 | class MemoryDepChecker { | |||
4322 | public: | |||
4323 | typedef PointerIntPair<Value *, 1, bool> MemAccessInfo; | |||
4324 | typedef SmallPtrSet<MemAccessInfo, 8> MemAccessInfoSet; | |||
4325 | ||||
4326 | MemoryDepChecker(ScalarEvolution *Se, const DataLayout *Dl, const Loop *L) | |||
4327 | : SE(Se), DL(Dl), InnermostLoop(L), AccessIdx(0), | |||
4328 | ShouldRetryWithRuntimeCheck(false) {} | |||
4329 | ||||
4330 | /// \brief Register the location (instructions are given increasing numbers) | |||
4331 | /// of a write access. | |||
4332 | void addAccess(StoreInst *SI) { | |||
4333 | Value *Ptr = SI->getPointerOperand(); | |||
4334 | Accesses[MemAccessInfo(Ptr, true)].push_back(AccessIdx); | |||
4335 | InstMap.push_back(SI); | |||
4336 | ++AccessIdx; | |||
4337 | } | |||
4338 | ||||
4339 | /// \brief Register the location (instructions are given increasing numbers) | |||
4340 | /// of a write access. | |||
4341 | void addAccess(LoadInst *LI) { | |||
4342 | Value *Ptr = LI->getPointerOperand(); | |||
4343 | Accesses[MemAccessInfo(Ptr, false)].push_back(AccessIdx); | |||
4344 | InstMap.push_back(LI); | |||
4345 | ++AccessIdx; | |||
4346 | } | |||
4347 | ||||
4348 | /// \brief Check whether the dependencies between the accesses are safe. | |||
4349 | /// | |||
4350 | /// Only checks sets with elements in \p CheckDeps. | |||
4351 | bool areDepsSafe(AccessAnalysis::DepCandidates &AccessSets, | |||
4352 | MemAccessInfoSet &CheckDeps, ValueToValueMap &Strides); | |||
4353 | ||||
4354 | /// \brief The maximum number of bytes of a vector register we can vectorize | |||
4355 | /// the accesses safely with. | |||
4356 | unsigned getMaxSafeDepDistBytes() { return MaxSafeDepDistBytes; } | |||
4357 | ||||
4358 | /// \brief In same cases when the dependency check fails we can still | |||
4359 | /// vectorize the loop with a dynamic array access check. | |||
4360 | bool shouldRetryWithRuntimeCheck() { return ShouldRetryWithRuntimeCheck; } | |||
4361 | ||||
4362 | private: | |||
4363 | ScalarEvolution *SE; | |||
4364 | const DataLayout *DL; | |||
4365 | const Loop *InnermostLoop; | |||
4366 | ||||
4367 | /// \brief Maps access locations (ptr, read/write) to program order. | |||
4368 | DenseMap<MemAccessInfo, std::vector<unsigned> > Accesses; | |||
4369 | ||||
4370 | /// \brief Memory access instructions in program order. | |||
4371 | SmallVector<Instruction *, 16> InstMap; | |||
4372 | ||||
4373 | /// \brief The program order index to be used for the next instruction. | |||
4374 | unsigned AccessIdx; | |||
4375 | ||||
4376 | // We can access this many bytes in parallel safely. | |||
4377 | unsigned MaxSafeDepDistBytes; | |||
4378 | ||||
4379 | /// \brief If we see a non-constant dependence distance we can still try to | |||
4380 | /// vectorize this loop with runtime checks. | |||
4381 | bool ShouldRetryWithRuntimeCheck; | |||
4382 | ||||
4383 | /// \brief Check whether there is a plausible dependence between the two | |||
4384 | /// accesses. | |||
4385 | /// | |||
4386 | /// Access \p A must happen before \p B in program order. The two indices | |||
4387 | /// identify the index into the program order map. | |||
4388 | /// | |||
4389 | /// This function checks whether there is a plausible dependence (or the | |||
4390 | /// absence of such can't be proved) between the two accesses. If there is a | |||
4391 | /// plausible dependence but the dependence distance is bigger than one | |||
4392 | /// element access it records this distance in \p MaxSafeDepDistBytes (if this | |||
4393 | /// distance is smaller than any other distance encountered so far). | |||
4394 | /// Otherwise, this function returns true signaling a possible dependence. | |||
4395 | bool isDependent(const MemAccessInfo &A, unsigned AIdx, | |||
4396 | const MemAccessInfo &B, unsigned BIdx, | |||
4397 | ValueToValueMap &Strides); | |||
4398 | ||||
4399 | /// \brief Check whether the data dependence could prevent store-load | |||
4400 | /// forwarding. | |||
4401 | bool couldPreventStoreLoadForward(unsigned Distance, unsigned TypeByteSize); | |||
4402 | }; | |||
4403 | ||||
4404 | } // end anonymous namespace | |||
4405 | ||||
4406 | static bool isInBoundsGep(Value *Ptr) { | |||
4407 | if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Ptr)) | |||
4408 | return GEP->isInBounds(); | |||
4409 | return false; | |||
4410 | } | |||
4411 | ||||
4412 | /// \brief Check whether the access through \p Ptr has a constant stride. | |||
4413 | static int isStridedPtr(ScalarEvolution *SE, const DataLayout *DL, Value *Ptr, | |||
4414 | const Loop *Lp, ValueToValueMap &StridesMap) { | |||
4415 | const Type *Ty = Ptr->getType(); | |||
4416 | assert(Ty->isPointerTy() && "Unexpected non-ptr")((Ty->isPointerTy() && "Unexpected non-ptr") ? static_cast <void> (0) : __assert_fail ("Ty->isPointerTy() && \"Unexpected non-ptr\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4416, __PRETTY_FUNCTION__)); | |||
4417 | ||||
4418 | // Make sure that the pointer does not point to aggregate types. | |||
4419 | const PointerType *PtrTy = cast<PointerType>(Ty); | |||
4420 | if (PtrTy->getElementType()->isAggregateType()) { | |||
4421 | DEBUG(dbgs() << "LV: Bad stride - Not a pointer to a scalar type" << *Ptr <<do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Bad stride - Not a pointer to a scalar type" << *Ptr << "\n"; } } while (0) | |||
4422 | "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Bad stride - Not a pointer to a scalar type" << *Ptr << "\n"; } } while (0); | |||
4423 | return 0; | |||
4424 | } | |||
4425 | ||||
4426 | const SCEV *PtrScev = replaceSymbolicStrideSCEV(SE, StridesMap, Ptr); | |||
4427 | ||||
4428 | const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(PtrScev); | |||
4429 | if (!AR) { | |||
4430 | DEBUG(dbgs() << "LV: Bad stride - Not an AddRecExpr pointer "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Bad stride - Not an AddRecExpr pointer " << *Ptr << " SCEV: " << *PtrScev << "\n" ; } } while (0) | |||
4431 | << *Ptr << " SCEV: " << *PtrScev << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Bad stride - Not an AddRecExpr pointer " << *Ptr << " SCEV: " << *PtrScev << "\n" ; } } while (0); | |||
4432 | return 0; | |||
4433 | } | |||
4434 | ||||
4435 | // The accesss function must stride over the innermost loop. | |||
4436 | if (Lp != AR->getLoop()) { | |||
4437 | DEBUG(dbgs() << "LV: Bad stride - Not striding over innermost loop " <<do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Bad stride - Not striding over innermost loop " << *Ptr << " SCEV: " << *PtrScev << "\n" ; } } while (0) | |||
4438 | *Ptr << " SCEV: " << *PtrScev << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Bad stride - Not striding over innermost loop " << *Ptr << " SCEV: " << *PtrScev << "\n" ; } } while (0); | |||
4439 | } | |||
4440 | ||||
4441 | // The address calculation must not wrap. Otherwise, a dependence could be | |||
4442 | // inverted. | |||
4443 | // An inbounds getelementptr that is a AddRec with a unit stride | |||
4444 | // cannot wrap per definition. The unit stride requirement is checked later. | |||
4445 | // An getelementptr without an inbounds attribute and unit stride would have | |||
4446 | // to access the pointer value "0" which is undefined behavior in address | |||
4447 | // space 0, therefore we can also vectorize this case. | |||
4448 | bool IsInBoundsGEP = isInBoundsGep(Ptr); | |||
4449 | bool IsNoWrapAddRec = AR->getNoWrapFlags(SCEV::NoWrapMask); | |||
4450 | bool IsInAddressSpaceZero = PtrTy->getAddressSpace() == 0; | |||
4451 | if (!IsNoWrapAddRec && !IsInBoundsGEP && !IsInAddressSpaceZero) { | |||
4452 | DEBUG(dbgs() << "LV: Bad stride - Pointer may wrap in the address space "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Bad stride - Pointer may wrap in the address space " << *Ptr << " SCEV: " << *PtrScev << "\n" ; } } while (0) | |||
4453 | << *Ptr << " SCEV: " << *PtrScev << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Bad stride - Pointer may wrap in the address space " << *Ptr << " SCEV: " << *PtrScev << "\n" ; } } while (0); | |||
4454 | return 0; | |||
4455 | } | |||
4456 | ||||
4457 | // Check the step is constant. | |||
4458 | const SCEV *Step = AR->getStepRecurrence(*SE); | |||
4459 | ||||
4460 | // Calculate the pointer stride and check if it is consecutive. | |||
4461 | const SCEVConstant *C = dyn_cast<SCEVConstant>(Step); | |||
4462 | if (!C) { | |||
4463 | DEBUG(dbgs() << "LV: Bad stride - Not a constant strided " << *Ptr <<do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Bad stride - Not a constant strided " << *Ptr << " SCEV: " << *PtrScev << "\n" ; } } while (0) | |||
4464 | " SCEV: " << *PtrScev << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Bad stride - Not a constant strided " << *Ptr << " SCEV: " << *PtrScev << "\n" ; } } while (0); | |||
4465 | return 0; | |||
4466 | } | |||
4467 | ||||
4468 | int64_t Size = DL->getTypeAllocSize(PtrTy->getElementType()); | |||
4469 | const APInt &APStepVal = C->getValue()->getValue(); | |||
4470 | ||||
4471 | // Huge step value - give up. | |||
4472 | if (APStepVal.getBitWidth() > 64) | |||
4473 | return 0; | |||
4474 | ||||
4475 | int64_t StepVal = APStepVal.getSExtValue(); | |||
4476 | ||||
4477 | // Strided access. | |||
4478 | int64_t Stride = StepVal / Size; | |||
4479 | int64_t Rem = StepVal % Size; | |||
4480 | if (Rem) | |||
4481 | return 0; | |||
4482 | ||||
4483 | // If the SCEV could wrap but we have an inbounds gep with a unit stride we | |||
4484 | // know we can't "wrap around the address space". In case of address space | |||
4485 | // zero we know that this won't happen without triggering undefined behavior. | |||
4486 | if (!IsNoWrapAddRec && (IsInBoundsGEP || IsInAddressSpaceZero) && | |||
4487 | Stride != 1 && Stride != -1) | |||
4488 | return 0; | |||
4489 | ||||
4490 | return Stride; | |||
4491 | } | |||
4492 | ||||
4493 | bool MemoryDepChecker::couldPreventStoreLoadForward(unsigned Distance, | |||
4494 | unsigned TypeByteSize) { | |||
4495 | // If loads occur at a distance that is not a multiple of a feasible vector | |||
4496 | // factor store-load forwarding does not take place. | |||
4497 | // Positive dependences might cause troubles because vectorizing them might | |||
4498 | // prevent store-load forwarding making vectorized code run a lot slower. | |||
4499 | // a[i] = a[i-3] ^ a[i-8]; | |||
4500 | // The stores to a[i:i+1] don't align with the stores to a[i-3:i-2] and | |||
4501 | // hence on your typical architecture store-load forwarding does not take | |||
4502 | // place. Vectorizing in such cases does not make sense. | |||
4503 | // Store-load forwarding distance. | |||
4504 | const unsigned NumCyclesForStoreLoadThroughMemory = 8*TypeByteSize; | |||
4505 | // Maximum vector factor. | |||
4506 | unsigned MaxVFWithoutSLForwardIssues = MaxVectorWidth*TypeByteSize; | |||
4507 | if(MaxSafeDepDistBytes < MaxVFWithoutSLForwardIssues) | |||
4508 | MaxVFWithoutSLForwardIssues = MaxSafeDepDistBytes; | |||
4509 | ||||
4510 | for (unsigned vf = 2*TypeByteSize; vf <= MaxVFWithoutSLForwardIssues; | |||
4511 | vf *= 2) { | |||
4512 | if (Distance % vf && Distance / vf < NumCyclesForStoreLoadThroughMemory) { | |||
4513 | MaxVFWithoutSLForwardIssues = (vf >>=1); | |||
4514 | break; | |||
4515 | } | |||
4516 | } | |||
4517 | ||||
4518 | if (MaxVFWithoutSLForwardIssues< 2*TypeByteSize) { | |||
4519 | DEBUG(dbgs() << "LV: Distance " << Distance <<do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Distance " << Distance << " that could cause a store-load forwarding conflict\n" ; } } while (0) | |||
4520 | " that could cause a store-load forwarding conflict\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Distance " << Distance << " that could cause a store-load forwarding conflict\n" ; } } while (0); | |||
4521 | return true; | |||
4522 | } | |||
4523 | ||||
4524 | if (MaxVFWithoutSLForwardIssues < MaxSafeDepDistBytes && | |||
4525 | MaxVFWithoutSLForwardIssues != MaxVectorWidth*TypeByteSize) | |||
4526 | MaxSafeDepDistBytes = MaxVFWithoutSLForwardIssues; | |||
4527 | return false; | |||
4528 | } | |||
4529 | ||||
4530 | bool MemoryDepChecker::isDependent(const MemAccessInfo &A, unsigned AIdx, | |||
4531 | const MemAccessInfo &B, unsigned BIdx, | |||
4532 | ValueToValueMap &Strides) { | |||
4533 | assert (AIdx < BIdx && "Must pass arguments in program order")((AIdx < BIdx && "Must pass arguments in program order" ) ? static_cast<void> (0) : __assert_fail ("AIdx < BIdx && \"Must pass arguments in program order\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4533, __PRETTY_FUNCTION__)); | |||
4534 | ||||
4535 | Value *APtr = A.getPointer(); | |||
4536 | Value *BPtr = B.getPointer(); | |||
4537 | bool AIsWrite = A.getInt(); | |||
4538 | bool BIsWrite = B.getInt(); | |||
4539 | ||||
4540 | // Two reads are independent. | |||
4541 | if (!AIsWrite && !BIsWrite) | |||
4542 | return false; | |||
4543 | ||||
4544 | // We cannot check pointers in different address spaces. | |||
4545 | if (APtr->getType()->getPointerAddressSpace() != | |||
4546 | BPtr->getType()->getPointerAddressSpace()) | |||
4547 | return true; | |||
4548 | ||||
4549 | const SCEV *AScev = replaceSymbolicStrideSCEV(SE, Strides, APtr); | |||
4550 | const SCEV *BScev = replaceSymbolicStrideSCEV(SE, Strides, BPtr); | |||
4551 | ||||
4552 | int StrideAPtr = isStridedPtr(SE, DL, APtr, InnermostLoop, Strides); | |||
4553 | int StrideBPtr = isStridedPtr(SE, DL, BPtr, InnermostLoop, Strides); | |||
4554 | ||||
4555 | const SCEV *Src = AScev; | |||
4556 | const SCEV *Sink = BScev; | |||
4557 | ||||
4558 | // If the induction step is negative we have to invert source and sink of the | |||
4559 | // dependence. | |||
4560 | if (StrideAPtr < 0) { | |||
4561 | //Src = BScev; | |||
4562 | //Sink = AScev; | |||
4563 | std::swap(APtr, BPtr); | |||
4564 | std::swap(Src, Sink); | |||
4565 | std::swap(AIsWrite, BIsWrite); | |||
4566 | std::swap(AIdx, BIdx); | |||
4567 | std::swap(StrideAPtr, StrideBPtr); | |||
4568 | } | |||
4569 | ||||
4570 | const SCEV *Dist = SE->getMinusSCEV(Sink, Src); | |||
4571 | ||||
4572 | DEBUG(dbgs() << "LV: Src Scev: " << *Src << "Sink Scev: " << *Sinkdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Src Scev: " << *Src << "Sink Scev: " << *Sink << "(Induction step: " << StrideAPtr << ")\n"; } } while (0) | |||
4573 | << "(Induction step: " << StrideAPtr << ")\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Src Scev: " << *Src << "Sink Scev: " << *Sink << "(Induction step: " << StrideAPtr << ")\n"; } } while (0); | |||
4574 | DEBUG(dbgs() << "LV: Distance for " << *InstMap[AIdx] << " to "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Distance for " << *InstMap[AIdx] << " to " << *InstMap[BIdx] << ": " << *Dist << "\n"; } } while (0) | |||
4575 | << *InstMap[BIdx] << ": " << *Dist << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Distance for " << *InstMap[AIdx] << " to " << *InstMap[BIdx] << ": " << *Dist << "\n"; } } while (0); | |||
4576 | ||||
4577 | // Need consecutive accesses. We don't want to vectorize | |||
4578 | // "A[B[i]] += ..." and similar code or pointer arithmetic that could wrap in | |||
4579 | // the address space. | |||
4580 | if (!StrideAPtr || !StrideBPtr || StrideAPtr != StrideBPtr){ | |||
4581 | DEBUG(dbgs() << "Non-consecutive pointer access\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "Non-consecutive pointer access\n" ; } } while (0); | |||
4582 | return true; | |||
4583 | } | |||
4584 | ||||
4585 | const SCEVConstant *C = dyn_cast<SCEVConstant>(Dist); | |||
4586 | if (!C) { | |||
4587 | DEBUG(dbgs() << "LV: Dependence because of non-constant distance\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Dependence because of non-constant distance\n" ; } } while (0); | |||
4588 | ShouldRetryWithRuntimeCheck = true; | |||
4589 | return true; | |||
4590 | } | |||
4591 | ||||
4592 | Type *ATy = APtr->getType()->getPointerElementType(); | |||
4593 | Type *BTy = BPtr->getType()->getPointerElementType(); | |||
4594 | unsigned TypeByteSize = DL->getTypeAllocSize(ATy); | |||
4595 | ||||
4596 | // Negative distances are not plausible dependencies. | |||
4597 | const APInt &Val = C->getValue()->getValue(); | |||
4598 | if (Val.isNegative()) { | |||
4599 | bool IsTrueDataDependence = (AIsWrite && !BIsWrite); | |||
4600 | if (IsTrueDataDependence && | |||
4601 | (couldPreventStoreLoadForward(Val.abs().getZExtValue(), TypeByteSize) || | |||
4602 | ATy != BTy)) | |||
4603 | return true; | |||
4604 | ||||
4605 | DEBUG(dbgs() << "LV: Dependence is negative: NoDep\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Dependence is negative: NoDep\n" ; } } while (0); | |||
4606 | return false; | |||
4607 | } | |||
4608 | ||||
4609 | // Write to the same location with the same size. | |||
4610 | // Could be improved to assert type sizes are the same (i32 == float, etc). | |||
4611 | if (Val == 0) { | |||
4612 | if (ATy == BTy) | |||
4613 | return false; | |||
4614 | DEBUG(dbgs() << "LV: Zero dependence difference but different types\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Zero dependence difference but different types\n" ; } } while (0); | |||
4615 | return true; | |||
4616 | } | |||
4617 | ||||
4618 | assert(Val.isStrictlyPositive() && "Expect a positive value")((Val.isStrictlyPositive() && "Expect a positive value" ) ? static_cast<void> (0) : __assert_fail ("Val.isStrictlyPositive() && \"Expect a positive value\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4618, __PRETTY_FUNCTION__)); | |||
4619 | ||||
4620 | // Positive distance bigger than max vectorization factor. | |||
4621 | if (ATy != BTy) { | |||
4622 | DEBUG(dbgs() <<do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: ReadWrite-Write positive dependency with different types\n" ; } } while (0) | |||
4623 | "LV: ReadWrite-Write positive dependency with different types\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: ReadWrite-Write positive dependency with different types\n" ; } } while (0); | |||
4624 | return false; | |||
4625 | } | |||
4626 | ||||
4627 | unsigned Distance = (unsigned) Val.getZExtValue(); | |||
4628 | ||||
4629 | // Bail out early if passed-in parameters make vectorization not feasible. | |||
4630 | unsigned ForcedFactor = VectorizationFactor ? VectorizationFactor : 1; | |||
4631 | unsigned ForcedUnroll = VectorizationInterleave ? VectorizationInterleave : 1; | |||
4632 | ||||
4633 | // The distance must be bigger than the size needed for a vectorized version | |||
4634 | // of the operation and the size of the vectorized operation must not be | |||
4635 | // bigger than the currrent maximum size. | |||
4636 | if (Distance < 2*TypeByteSize || | |||
4637 | 2*TypeByteSize > MaxSafeDepDistBytes || | |||
4638 | Distance < TypeByteSize * ForcedUnroll * ForcedFactor) { | |||
4639 | DEBUG(dbgs() << "LV: Failure because of Positive distance "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Failure because of Positive distance " << Val.getSExtValue() << '\n'; } } while (0) | |||
4640 | << Val.getSExtValue() << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Failure because of Positive distance " << Val.getSExtValue() << '\n'; } } while (0); | |||
4641 | return true; | |||
4642 | } | |||
4643 | ||||
4644 | MaxSafeDepDistBytes = Distance < MaxSafeDepDistBytes ? | |||
4645 | Distance : MaxSafeDepDistBytes; | |||
4646 | ||||
4647 | bool IsTrueDataDependence = (!AIsWrite && BIsWrite); | |||
4648 | if (IsTrueDataDependence && | |||
4649 | couldPreventStoreLoadForward(Distance, TypeByteSize)) | |||
4650 | return true; | |||
4651 | ||||
4652 | DEBUG(dbgs() << "LV: Positive distance " << Val.getSExtValue() <<do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Positive distance " << Val.getSExtValue() << " with max VF = " << MaxSafeDepDistBytes / TypeByteSize << '\n'; } } while ( 0) | |||
4653 | " with max VF = " << MaxSafeDepDistBytes / TypeByteSize << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Positive distance " << Val.getSExtValue() << " with max VF = " << MaxSafeDepDistBytes / TypeByteSize << '\n'; } } while ( 0); | |||
4654 | ||||
4655 | return false; | |||
4656 | } | |||
4657 | ||||
4658 | bool MemoryDepChecker::areDepsSafe(AccessAnalysis::DepCandidates &AccessSets, | |||
4659 | MemAccessInfoSet &CheckDeps, | |||
4660 | ValueToValueMap &Strides) { | |||
4661 | ||||
4662 | MaxSafeDepDistBytes = -1U; | |||
4663 | while (!CheckDeps.empty()) { | |||
4664 | MemAccessInfo CurAccess = *CheckDeps.begin(); | |||
4665 | ||||
4666 | // Get the relevant memory access set. | |||
4667 | EquivalenceClasses<MemAccessInfo>::iterator I = | |||
4668 | AccessSets.findValue(AccessSets.getLeaderValue(CurAccess)); | |||
4669 | ||||
4670 | // Check accesses within this set. | |||
4671 | EquivalenceClasses<MemAccessInfo>::member_iterator AI, AE; | |||
4672 | AI = AccessSets.member_begin(I), AE = AccessSets.member_end(); | |||
4673 | ||||
4674 | // Check every access pair. | |||
4675 | while (AI != AE) { | |||
4676 | CheckDeps.erase(*AI); | |||
4677 | EquivalenceClasses<MemAccessInfo>::member_iterator OI = std::next(AI); | |||
4678 | while (OI != AE) { | |||
4679 | // Check every accessing instruction pair in program order. | |||
4680 | for (std::vector<unsigned>::iterator I1 = Accesses[*AI].begin(), | |||
4681 | I1E = Accesses[*AI].end(); I1 != I1E; ++I1) | |||
4682 | for (std::vector<unsigned>::iterator I2 = Accesses[*OI].begin(), | |||
4683 | I2E = Accesses[*OI].end(); I2 != I2E; ++I2) { | |||
4684 | if (*I1 < *I2 && isDependent(*AI, *I1, *OI, *I2, Strides)) | |||
4685 | return false; | |||
4686 | if (*I2 < *I1 && isDependent(*OI, *I2, *AI, *I1, Strides)) | |||
4687 | return false; | |||
4688 | } | |||
4689 | ++OI; | |||
4690 | } | |||
4691 | AI++; | |||
4692 | } | |||
4693 | } | |||
4694 | return true; | |||
4695 | } | |||
4696 | ||||
4697 | bool LoopVectorizationLegality::canVectorizeMemory() { | |||
4698 | ||||
4699 | typedef SmallVector<Value*, 16> ValueVector; | |||
4700 | typedef SmallPtrSet<Value*, 16> ValueSet; | |||
4701 | ||||
4702 | // Holds the Load and Store *instructions*. | |||
4703 | ValueVector Loads; | |||
4704 | ValueVector Stores; | |||
4705 | ||||
4706 | // Holds all the different accesses in the loop. | |||
4707 | unsigned NumReads = 0; | |||
4708 | unsigned NumReadWrites = 0; | |||
4709 | ||||
4710 | PtrRtCheck.Pointers.clear(); | |||
4711 | PtrRtCheck.Need = false; | |||
4712 | ||||
4713 | const bool IsAnnotatedParallel = TheLoop->isAnnotatedParallel(); | |||
4714 | MemoryDepChecker DepChecker(SE, DL, TheLoop); | |||
4715 | ||||
4716 | // For each block. | |||
4717 | for (Loop::block_iterator bb = TheLoop->block_begin(), | |||
4718 | be = TheLoop->block_end(); bb != be; ++bb) { | |||
4719 | ||||
4720 | // Scan the BB and collect legal loads and stores. | |||
4721 | for (BasicBlock::iterator it = (*bb)->begin(), e = (*bb)->end(); it != e; | |||
4722 | ++it) { | |||
4723 | ||||
4724 | // If this is a load, save it. If this instruction can read from memory | |||
4725 | // but is not a load, then we quit. Notice that we don't handle function | |||
4726 | // calls that read or write. | |||
4727 | if (it->mayReadFromMemory()) { | |||
4728 | // Many math library functions read the rounding mode. We will only | |||
4729 | // vectorize a loop if it contains known function calls that don't set | |||
4730 | // the flag. Therefore, it is safe to ignore this read from memory. | |||
4731 | CallInst *Call = dyn_cast<CallInst>(it); | |||
4732 | if (Call && getIntrinsicIDForCall(Call, TLI)) | |||
4733 | continue; | |||
4734 | ||||
4735 | LoadInst *Ld = dyn_cast<LoadInst>(it); | |||
4736 | if (!Ld || (!Ld->isSimple() && !IsAnnotatedParallel)) { | |||
4737 | emitAnalysis(Report(Ld) | |||
4738 | << "read with atomic ordering or volatile read"); | |||
4739 | DEBUG(dbgs() << "LV: Found a non-simple load.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found a non-simple load.\n" ; } } while (0); | |||
4740 | return false; | |||
4741 | } | |||
4742 | NumLoads++; | |||
4743 | Loads.push_back(Ld); | |||
4744 | DepChecker.addAccess(Ld); | |||
4745 | continue; | |||
4746 | } | |||
4747 | ||||
4748 | // Save 'store' instructions. Abort if other instructions write to memory. | |||
4749 | if (it->mayWriteToMemory()) { | |||
4750 | StoreInst *St = dyn_cast<StoreInst>(it); | |||
4751 | if (!St) { | |||
4752 | emitAnalysis(Report(it) << "instruction cannot be vectorized"); | |||
4753 | return false; | |||
4754 | } | |||
4755 | if (!St->isSimple() && !IsAnnotatedParallel) { | |||
4756 | emitAnalysis(Report(St) | |||
4757 | << "write with atomic ordering or volatile write"); | |||
4758 | DEBUG(dbgs() << "LV: Found a non-simple store.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found a non-simple store.\n" ; } } while (0); | |||
4759 | return false; | |||
4760 | } | |||
4761 | NumStores++; | |||
4762 | Stores.push_back(St); | |||
4763 | DepChecker.addAccess(St); | |||
4764 | } | |||
4765 | } // Next instr. | |||
4766 | } // Next block. | |||
4767 | ||||
4768 | // Now we have two lists that hold the loads and the stores. | |||
4769 | // Next, we find the pointers that they use. | |||
4770 | ||||
4771 | // Check if we see any stores. If there are no stores, then we don't | |||
4772 | // care if the pointers are *restrict*. | |||
4773 | if (!Stores.size()) { | |||
4774 | DEBUG(dbgs() << "LV: Found a read-only loop!\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found a read-only loop!\n" ; } } while (0); | |||
4775 | return true; | |||
4776 | } | |||
4777 | ||||
4778 | AccessAnalysis::DepCandidates DependentAccesses; | |||
4779 | AccessAnalysis Accesses(DL, AA, DependentAccesses); | |||
4780 | ||||
4781 | // Holds the analyzed pointers. We don't want to call GetUnderlyingObjects | |||
4782 | // multiple times on the same object. If the ptr is accessed twice, once | |||
4783 | // for read and once for write, it will only appear once (on the write | |||
4784 | // list). This is okay, since we are going to check for conflicts between | |||
4785 | // writes and between reads and writes, but not between reads and reads. | |||
4786 | ValueSet Seen; | |||
4787 | ||||
4788 | ValueVector::iterator I, IE; | |||
4789 | for (I = Stores.begin(), IE = Stores.end(); I != IE; ++I) { | |||
4790 | StoreInst *ST = cast<StoreInst>(*I); | |||
4791 | Value* Ptr = ST->getPointerOperand(); | |||
4792 | ||||
4793 | if (isUniform(Ptr)) { | |||
4794 | emitAnalysis( | |||
4795 | Report(ST) | |||
4796 | << "write to a loop invariant address could not be vectorized"); | |||
4797 | DEBUG(dbgs() << "LV: We don't allow storing to uniform addresses\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: We don't allow storing to uniform addresses\n" ; } } while (0); | |||
4798 | return false; | |||
4799 | } | |||
4800 | ||||
4801 | // If we did *not* see this pointer before, insert it to the read-write | |||
4802 | // list. At this phase it is only a 'write' list. | |||
4803 | if (Seen.insert(Ptr)) { | |||
4804 | ++NumReadWrites; | |||
4805 | ||||
4806 | AliasAnalysis::Location Loc = AA->getLocation(ST); | |||
4807 | // The TBAA metadata could have a control dependency on the predication | |||
4808 | // condition, so we cannot rely on it when determining whether or not we | |||
4809 | // need runtime pointer checks. | |||
4810 | if (blockNeedsPredication(ST->getParent())) | |||
4811 | Loc.AATags.TBAA = nullptr; | |||
4812 | ||||
4813 | Accesses.addStore(Loc); | |||
4814 | } | |||
4815 | } | |||
4816 | ||||
4817 | if (IsAnnotatedParallel) { | |||
4818 | DEBUG(dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: A loop annotated parallel, ignore memory dependency " << "checks.\n"; } } while (0) | |||
4819 | << "LV: A loop annotated parallel, ignore memory dependency "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: A loop annotated parallel, ignore memory dependency " << "checks.\n"; } } while (0) | |||
4820 | << "checks.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: A loop annotated parallel, ignore memory dependency " << "checks.\n"; } } while (0); | |||
4821 | return true; | |||
4822 | } | |||
4823 | ||||
4824 | for (I = Loads.begin(), IE = Loads.end(); I != IE; ++I) { | |||
4825 | LoadInst *LD = cast<LoadInst>(*I); | |||
4826 | Value* Ptr = LD->getPointerOperand(); | |||
4827 | // If we did *not* see this pointer before, insert it to the | |||
4828 | // read list. If we *did* see it before, then it is already in | |||
4829 | // the read-write list. This allows us to vectorize expressions | |||
4830 | // such as A[i] += x; Because the address of A[i] is a read-write | |||
4831 | // pointer. This only works if the index of A[i] is consecutive. | |||
4832 | // If the address of i is unknown (for example A[B[i]]) then we may | |||
4833 | // read a few words, modify, and write a few words, and some of the | |||
4834 | // words may be written to the same address. | |||
4835 | bool IsReadOnlyPtr = false; | |||
4836 | if (Seen.insert(Ptr) || !isStridedPtr(SE, DL, Ptr, TheLoop, Strides)) { | |||
4837 | ++NumReads; | |||
4838 | IsReadOnlyPtr = true; | |||
4839 | } | |||
4840 | ||||
4841 | AliasAnalysis::Location Loc = AA->getLocation(LD); | |||
4842 | // The TBAA metadata could have a control dependency on the predication | |||
4843 | // condition, so we cannot rely on it when determining whether or not we | |||
4844 | // need runtime pointer checks. | |||
4845 | if (blockNeedsPredication(LD->getParent())) | |||
4846 | Loc.AATags.TBAA = nullptr; | |||
4847 | ||||
4848 | Accesses.addLoad(Loc, IsReadOnlyPtr); | |||
4849 | } | |||
4850 | ||||
4851 | // If we write (or read-write) to a single destination and there are no | |||
4852 | // other reads in this loop then is it safe to vectorize. | |||
4853 | if (NumReadWrites == 1 && NumReads == 0) { | |||
4854 | DEBUG(dbgs() << "LV: Found a write-only loop!\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found a write-only loop!\n" ; } } while (0); | |||
4855 | return true; | |||
4856 | } | |||
4857 | ||||
4858 | // Build dependence sets and check whether we need a runtime pointer bounds | |||
4859 | // check. | |||
4860 | Accesses.buildDependenceSets(); | |||
4861 | bool NeedRTCheck = Accesses.isRTCheckNeeded(); | |||
4862 | ||||
4863 | // Find pointers with computable bounds. We are going to use this information | |||
4864 | // to place a runtime bound check. | |||
4865 | unsigned NumComparisons = 0; | |||
4866 | bool CanDoRT = false; | |||
4867 | if (NeedRTCheck) | |||
4868 | CanDoRT = Accesses.canCheckPtrAtRT(PtrRtCheck, NumComparisons, SE, TheLoop, | |||
4869 | Strides); | |||
4870 | ||||
4871 | DEBUG(dbgs() << "LV: We need to do " << NumComparisons <<do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: We need to do " << NumComparisons << " pointer comparisons.\n"; } } while (0) | |||
4872 | " pointer comparisons.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: We need to do " << NumComparisons << " pointer comparisons.\n"; } } while (0); | |||
4873 | ||||
4874 | // If we only have one set of dependences to check pointers among we don't | |||
4875 | // need a runtime check. | |||
4876 | if (NumComparisons == 0 && NeedRTCheck) | |||
4877 | NeedRTCheck = false; | |||
4878 | ||||
4879 | // Check that we did not collect too many pointers or found an unsizeable | |||
4880 | // pointer. | |||
4881 | if (!CanDoRT || NumComparisons > RuntimeMemoryCheckThreshold) { | |||
4882 | PtrRtCheck.reset(); | |||
4883 | CanDoRT = false; | |||
4884 | } | |||
4885 | ||||
4886 | if (CanDoRT) { | |||
4887 | DEBUG(dbgs() << "LV: We can perform a memory runtime check if needed.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: We can perform a memory runtime check if needed.\n" ; } } while (0); | |||
4888 | } | |||
4889 | ||||
4890 | if (NeedRTCheck && !CanDoRT) { | |||
4891 | emitAnalysis(Report() << "cannot identify array bounds"); | |||
4892 | DEBUG(dbgs() << "LV: We can't vectorize because we can't find " <<do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: We can't vectorize because we can't find " << "the array bounds.\n"; } } while (0) | |||
4893 | "the array bounds.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: We can't vectorize because we can't find " << "the array bounds.\n"; } } while (0); | |||
4894 | PtrRtCheck.reset(); | |||
4895 | return false; | |||
4896 | } | |||
4897 | ||||
4898 | PtrRtCheck.Need = NeedRTCheck; | |||
4899 | ||||
4900 | bool CanVecMem = true; | |||
4901 | if (Accesses.isDependencyCheckNeeded()) { | |||
4902 | DEBUG(dbgs() << "LV: Checking memory dependencies\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Checking memory dependencies\n" ; } } while (0); | |||
4903 | CanVecMem = DepChecker.areDepsSafe( | |||
4904 | DependentAccesses, Accesses.getDependenciesToCheck(), Strides); | |||
4905 | MaxSafeDepDistBytes = DepChecker.getMaxSafeDepDistBytes(); | |||
4906 | ||||
4907 | if (!CanVecMem && DepChecker.shouldRetryWithRuntimeCheck()) { | |||
4908 | DEBUG(dbgs() << "LV: Retrying with memory checks\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Retrying with memory checks\n" ; } } while (0); | |||
4909 | NeedRTCheck = true; | |||
4910 | ||||
4911 | // Clear the dependency checks. We assume they are not needed. | |||
4912 | Accesses.resetDepChecks(); | |||
4913 | ||||
4914 | PtrRtCheck.reset(); | |||
4915 | PtrRtCheck.Need = true; | |||
4916 | ||||
4917 | CanDoRT = Accesses.canCheckPtrAtRT(PtrRtCheck, NumComparisons, SE, | |||
4918 | TheLoop, Strides, true); | |||
4919 | // Check that we did not collect too many pointers or found an unsizeable | |||
4920 | // pointer. | |||
4921 | if (!CanDoRT || NumComparisons > RuntimeMemoryCheckThreshold) { | |||
4922 | if (!CanDoRT && NumComparisons > 0) | |||
4923 | emitAnalysis(Report() | |||
4924 | << "cannot check memory dependencies at runtime"); | |||
4925 | else | |||
4926 | emitAnalysis(Report() | |||
4927 | << NumComparisons << " exceeds limit of " | |||
4928 | << RuntimeMemoryCheckThreshold | |||
4929 | << " dependent memory operations checked at runtime"); | |||
4930 | DEBUG(dbgs() << "LV: Can't vectorize with memory checks\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Can't vectorize with memory checks\n" ; } } while (0); | |||
4931 | PtrRtCheck.reset(); | |||
4932 | return false; | |||
4933 | } | |||
4934 | ||||
4935 | CanVecMem = true; | |||
4936 | } | |||
4937 | } | |||
4938 | ||||
4939 | if (!CanVecMem) | |||
4940 | emitAnalysis(Report() << "unsafe dependent memory operations in loop"); | |||
4941 | ||||
4942 | DEBUG(dbgs() << "LV: We" << (NeedRTCheck ? "" : " don't") <<do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: We" << (NeedRTCheck ? "" : " don't") << " need a runtime memory check.\n"; } } while (0) | |||
4943 | " need a runtime memory check.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: We" << (NeedRTCheck ? "" : " don't") << " need a runtime memory check.\n"; } } while (0); | |||
4944 | ||||
4945 | return CanVecMem; | |||
4946 | } | |||
4947 | ||||
4948 | static bool hasMultipleUsesOf(Instruction *I, | |||
4949 | SmallPtrSetImpl<Instruction *> &Insts) { | |||
4950 | unsigned NumUses = 0; | |||
4951 | for(User::op_iterator Use = I->op_begin(), E = I->op_end(); Use != E; ++Use) { | |||
4952 | if (Insts.count(dyn_cast<Instruction>(*Use))) | |||
4953 | ++NumUses; | |||
4954 | if (NumUses > 1) | |||
4955 | return true; | |||
4956 | } | |||
4957 | ||||
4958 | return false; | |||
4959 | } | |||
4960 | ||||
4961 | static bool areAllUsesIn(Instruction *I, SmallPtrSetImpl<Instruction *> &Set) { | |||
4962 | for(User::op_iterator Use = I->op_begin(), E = I->op_end(); Use != E; ++Use) | |||
4963 | if (!Set.count(dyn_cast<Instruction>(*Use))) | |||
4964 | return false; | |||
4965 | return true; | |||
4966 | } | |||
4967 | ||||
4968 | bool LoopVectorizationLegality::AddReductionVar(PHINode *Phi, | |||
4969 | ReductionKind Kind) { | |||
4970 | if (Phi->getNumIncomingValues() != 2) | |||
4971 | return false; | |||
4972 | ||||
4973 | // Reduction variables are only found in the loop header block. | |||
4974 | if (Phi->getParent() != TheLoop->getHeader()) | |||
4975 | return false; | |||
4976 | ||||
4977 | // Obtain the reduction start value from the value that comes from the loop | |||
4978 | // preheader. | |||
4979 | Value *RdxStart = Phi->getIncomingValueForBlock(TheLoop->getLoopPreheader()); | |||
4980 | ||||
4981 | // ExitInstruction is the single value which is used outside the loop. | |||
4982 | // We only allow for a single reduction value to be used outside the loop. | |||
4983 | // This includes users of the reduction, variables (which form a cycle | |||
4984 | // which ends in the phi node). | |||
4985 | Instruction *ExitInstruction = nullptr; | |||
4986 | // Indicates that we found a reduction operation in our scan. | |||
4987 | bool FoundReduxOp = false; | |||
4988 | ||||
4989 | // We start with the PHI node and scan for all of the users of this | |||
4990 | // instruction. All users must be instructions that can be used as reduction | |||
4991 | // variables (such as ADD). We must have a single out-of-block user. The cycle | |||
4992 | // must include the original PHI. | |||
4993 | bool FoundStartPHI = false; | |||
4994 | ||||
4995 | // To recognize min/max patterns formed by a icmp select sequence, we store | |||
4996 | // the number of instruction we saw from the recognized min/max pattern, | |||
4997 | // to make sure we only see exactly the two instructions. | |||
4998 | unsigned NumCmpSelectPatternInst = 0; | |||
4999 | ReductionInstDesc ReduxDesc(false, nullptr); | |||
5000 | ||||
5001 | SmallPtrSet<Instruction *, 8> VisitedInsts; | |||
5002 | SmallVector<Instruction *, 8> Worklist; | |||
5003 | Worklist.push_back(Phi); | |||
5004 | VisitedInsts.insert(Phi); | |||
5005 | ||||
5006 | // A value in the reduction can be used: | |||
5007 | // - By the reduction: | |||
5008 | // - Reduction operation: | |||
5009 | // - One use of reduction value (safe). | |||
5010 | // - Multiple use of reduction value (not safe). | |||
5011 | // - PHI: | |||
5012 | // - All uses of the PHI must be the reduction (safe). | |||
5013 | // - Otherwise, not safe. | |||
5014 | // - By one instruction outside of the loop (safe). | |||
5015 | // - By further instructions outside of the loop (not safe). | |||
5016 | // - By an instruction that is not part of the reduction (not safe). | |||
5017 | // This is either: | |||
5018 | // * An instruction type other than PHI or the reduction operation. | |||
5019 | // * A PHI in the header other than the initial PHI. | |||
5020 | while (!Worklist.empty()) { | |||
5021 | Instruction *Cur = Worklist.back(); | |||
5022 | Worklist.pop_back(); | |||
5023 | ||||
5024 | // No Users. | |||
5025 | // If the instruction has no users then this is a broken chain and can't be | |||
5026 | // a reduction variable. | |||
5027 | if (Cur->use_empty()) | |||
5028 | return false; | |||
5029 | ||||
5030 | bool IsAPhi = isa<PHINode>(Cur); | |||
5031 | ||||
5032 | // A header PHI use other than the original PHI. | |||
5033 | if (Cur != Phi && IsAPhi && Cur->getParent() == Phi->getParent()) | |||
5034 | return false; | |||
5035 | ||||
5036 | // Reductions of instructions such as Div, and Sub is only possible if the | |||
5037 | // LHS is the reduction variable. | |||
5038 | if (!Cur->isCommutative() && !IsAPhi && !isa<SelectInst>(Cur) && | |||
5039 | !isa<ICmpInst>(Cur) && !isa<FCmpInst>(Cur) && | |||
5040 | !VisitedInsts.count(dyn_cast<Instruction>(Cur->getOperand(0)))) | |||
5041 | return false; | |||
5042 | ||||
5043 | // Any reduction instruction must be of one of the allowed kinds. | |||
5044 | ReduxDesc = isReductionInstr(Cur, Kind, ReduxDesc); | |||
5045 | if (!ReduxDesc.IsReduction) | |||
5046 | return false; | |||
5047 | ||||
5048 | // A reduction operation must only have one use of the reduction value. | |||
5049 | if (!IsAPhi && Kind != RK_IntegerMinMax && Kind != RK_FloatMinMax && | |||
5050 | hasMultipleUsesOf(Cur, VisitedInsts)) | |||
5051 | return false; | |||
5052 | ||||
5053 | // All inputs to a PHI node must be a reduction value. | |||
5054 | if(IsAPhi && Cur != Phi && !areAllUsesIn(Cur, VisitedInsts)) | |||
5055 | return false; | |||
5056 | ||||
5057 | if (Kind == RK_IntegerMinMax && (isa<ICmpInst>(Cur) || | |||
5058 | isa<SelectInst>(Cur))) | |||
5059 | ++NumCmpSelectPatternInst; | |||
5060 | if (Kind == RK_FloatMinMax && (isa<FCmpInst>(Cur) || | |||
5061 | isa<SelectInst>(Cur))) | |||
5062 | ++NumCmpSelectPatternInst; | |||
5063 | ||||
5064 | // Check whether we found a reduction operator. | |||
5065 | FoundReduxOp |= !IsAPhi; | |||
5066 | ||||
5067 | // Process users of current instruction. Push non-PHI nodes after PHI nodes | |||
5068 | // onto the stack. This way we are going to have seen all inputs to PHI | |||
5069 | // nodes once we get to them. | |||
5070 | SmallVector<Instruction *, 8> NonPHIs; | |||
5071 | SmallVector<Instruction *, 8> PHIs; | |||
5072 | for (User *U : Cur->users()) { | |||
5073 | Instruction *UI = cast<Instruction>(U); | |||
5074 | ||||
5075 | // Check if we found the exit user. | |||
5076 | BasicBlock *Parent = UI->getParent(); | |||
5077 | if (!TheLoop->contains(Parent)) { | |||
5078 | // Exit if you find multiple outside users or if the header phi node is | |||
5079 | // being used. In this case the user uses the value of the previous | |||
5080 | // iteration, in which case we would loose "VF-1" iterations of the | |||
5081 | // reduction operation if we vectorize. | |||
5082 | if (ExitInstruction != nullptr || Cur == Phi) | |||
5083 | return false; | |||
5084 | ||||
5085 | // The instruction used by an outside user must be the last instruction | |||
5086 | // before we feed back to the reduction phi. Otherwise, we loose VF-1 | |||
5087 | // operations on the value. | |||
5088 | if (std::find(Phi->op_begin(), Phi->op_end(), Cur) == Phi->op_end()) | |||
5089 | return false; | |||
5090 | ||||
5091 | ExitInstruction = Cur; | |||
5092 | continue; | |||
5093 | } | |||
5094 | ||||
5095 | // Process instructions only once (termination). Each reduction cycle | |||
5096 | // value must only be used once, except by phi nodes and min/max | |||
5097 | // reductions which are represented as a cmp followed by a select. | |||
5098 | ReductionInstDesc IgnoredVal(false, nullptr); | |||
5099 | if (VisitedInsts.insert(UI)) { | |||
5100 | if (isa<PHINode>(UI)) | |||
5101 | PHIs.push_back(UI); | |||
5102 | else | |||
5103 | NonPHIs.push_back(UI); | |||
5104 | } else if (!isa<PHINode>(UI) && | |||
5105 | ((!isa<FCmpInst>(UI) && | |||
5106 | !isa<ICmpInst>(UI) && | |||
5107 | !isa<SelectInst>(UI)) || | |||
5108 | !isMinMaxSelectCmpPattern(UI, IgnoredVal).IsReduction)) | |||
5109 | return false; | |||
5110 | ||||
5111 | // Remember that we completed the cycle. | |||
5112 | if (UI == Phi) | |||
5113 | FoundStartPHI = true; | |||
5114 | } | |||
5115 | Worklist.append(PHIs.begin(), PHIs.end()); | |||
5116 | Worklist.append(NonPHIs.begin(), NonPHIs.end()); | |||
5117 | } | |||
5118 | ||||
5119 | // This means we have seen one but not the other instruction of the | |||
5120 | // pattern or more than just a select and cmp. | |||
5121 | if ((Kind == RK_IntegerMinMax || Kind == RK_FloatMinMax) && | |||
5122 | NumCmpSelectPatternInst != 2) | |||
5123 | return false; | |||
5124 | ||||
5125 | if (!FoundStartPHI || !FoundReduxOp || !ExitInstruction) | |||
5126 | return false; | |||
5127 | ||||
5128 | // We found a reduction var if we have reached the original phi node and we | |||
5129 | // only have a single instruction with out-of-loop users. | |||
5130 | ||||
5131 | // This instruction is allowed to have out-of-loop users. | |||
5132 | AllowedExit.insert(ExitInstruction); | |||
5133 | ||||
5134 | // Save the description of this reduction variable. | |||
5135 | ReductionDescriptor RD(RdxStart, ExitInstruction, Kind, | |||
5136 | ReduxDesc.MinMaxKind); | |||
5137 | Reductions[Phi] = RD; | |||
5138 | // We've ended the cycle. This is a reduction variable if we have an | |||
5139 | // outside user and it has a binary op. | |||
5140 | ||||
5141 | return true; | |||
5142 | } | |||
5143 | ||||
5144 | /// Returns true if the instruction is a Select(ICmp(X, Y), X, Y) instruction | |||
5145 | /// pattern corresponding to a min(X, Y) or max(X, Y). | |||
5146 | LoopVectorizationLegality::ReductionInstDesc | |||
5147 | LoopVectorizationLegality::isMinMaxSelectCmpPattern(Instruction *I, | |||
5148 | ReductionInstDesc &Prev) { | |||
5149 | ||||
5150 | assert((isa<ICmpInst>(I) || isa<FCmpInst>(I) || isa<SelectInst>(I)) &&(((isa<ICmpInst>(I) || isa<FCmpInst>(I) || isa< SelectInst>(I)) && "Expect a select instruction") ? static_cast<void> (0) : __assert_fail ("(isa<ICmpInst>(I) || isa<FCmpInst>(I) || isa<SelectInst>(I)) && \"Expect a select instruction\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 5151, __PRETTY_FUNCTION__)) | |||
5151 | "Expect a select instruction")(((isa<ICmpInst>(I) || isa<FCmpInst>(I) || isa< SelectInst>(I)) && "Expect a select instruction") ? static_cast<void> (0) : __assert_fail ("(isa<ICmpInst>(I) || isa<FCmpInst>(I) || isa<SelectInst>(I)) && \"Expect a select instruction\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 5151, __PRETTY_FUNCTION__)); | |||
5152 | Instruction *Cmp = nullptr; | |||
5153 | SelectInst *Select = nullptr; | |||
5154 | ||||
5155 | // We must handle the select(cmp()) as a single instruction. Advance to the | |||
5156 | // select. | |||
5157 | if ((Cmp = dyn_cast<ICmpInst>(I)) || (Cmp = dyn_cast<FCmpInst>(I))) { | |||
5158 | if (!Cmp->hasOneUse() || !(Select = dyn_cast<SelectInst>(*I->user_begin()))) | |||
5159 | return ReductionInstDesc(false, I); | |||
5160 | return ReductionInstDesc(Select, Prev.MinMaxKind); | |||
5161 | } | |||
5162 | ||||
5163 | // Only handle single use cases for now. | |||
5164 | if (!(Select = dyn_cast<SelectInst>(I))) | |||
5165 | return ReductionInstDesc(false, I); | |||
5166 | if (!(Cmp = dyn_cast<ICmpInst>(I->getOperand(0))) && | |||
5167 | !(Cmp = dyn_cast<FCmpInst>(I->getOperand(0)))) | |||
5168 | return ReductionInstDesc(false, I); | |||
5169 | if (!Cmp->hasOneUse()) | |||
5170 | return ReductionInstDesc(false, I); | |||
5171 | ||||
5172 | Value *CmpLeft; | |||
5173 | Value *CmpRight; | |||
5174 | ||||
5175 | // Look for a min/max pattern. | |||
5176 | if (m_UMin(m_Value(CmpLeft), m_Value(CmpRight)).match(Select)) | |||
5177 | return ReductionInstDesc(Select, MRK_UIntMin); | |||
5178 | else if (m_UMax(m_Value(CmpLeft), m_Value(CmpRight)).match(Select)) | |||
5179 | return ReductionInstDesc(Select, MRK_UIntMax); | |||
5180 | else if (m_SMax(m_Value(CmpLeft), m_Value(CmpRight)).match(Select)) | |||
5181 | return ReductionInstDesc(Select, MRK_SIntMax); | |||
5182 | else if (m_SMin(m_Value(CmpLeft), m_Value(CmpRight)).match(Select)) | |||
5183 | return ReductionInstDesc(Select, MRK_SIntMin); | |||
5184 | else if (m_OrdFMin(m_Value(CmpLeft), m_Value(CmpRight)).match(Select)) | |||
5185 | return ReductionInstDesc(Select, MRK_FloatMin); | |||
5186 | else if (m_OrdFMax(m_Value(CmpLeft), m_Value(CmpRight)).match(Select)) | |||
5187 | return ReductionInstDesc(Select, MRK_FloatMax); | |||
5188 | else if (m_UnordFMin(m_Value(CmpLeft), m_Value(CmpRight)).match(Select)) | |||
5189 | return ReductionInstDesc(Select, MRK_FloatMin); | |||
5190 | else if (m_UnordFMax(m_Value(CmpLeft), m_Value(CmpRight)).match(Select)) | |||
5191 | return ReductionInstDesc(Select, MRK_FloatMax); | |||
5192 | ||||
5193 | return ReductionInstDesc(false, I); | |||
5194 | } | |||
5195 | ||||
5196 | LoopVectorizationLegality::ReductionInstDesc | |||
5197 | LoopVectorizationLegality::isReductionInstr(Instruction *I, | |||
5198 | ReductionKind Kind, | |||
5199 | ReductionInstDesc &Prev) { | |||
5200 | bool FP = I->getType()->isFloatingPointTy(); | |||
5201 | bool FastMath = FP && I->hasUnsafeAlgebra(); | |||
5202 | switch (I->getOpcode()) { | |||
5203 | default: | |||
5204 | return ReductionInstDesc(false, I); | |||
5205 | case Instruction::PHI: | |||
5206 | if (FP && (Kind != RK_FloatMult && Kind != RK_FloatAdd && | |||
5207 | Kind != RK_FloatMinMax)) | |||
5208 | return ReductionInstDesc(false, I); | |||
5209 | return ReductionInstDesc(I, Prev.MinMaxKind); | |||
5210 | case Instruction::Sub: | |||
5211 | case Instruction::Add: | |||
5212 | return ReductionInstDesc(Kind == RK_IntegerAdd, I); | |||
5213 | case Instruction::Mul: | |||
5214 | return ReductionInstDesc(Kind == RK_IntegerMult, I); | |||
5215 | case Instruction::And: | |||
5216 | return ReductionInstDesc(Kind == RK_IntegerAnd, I); | |||
5217 | case Instruction::Or: | |||
5218 | return ReductionInstDesc(Kind == RK_IntegerOr, I); | |||
5219 | case Instruction::Xor: | |||
5220 | return ReductionInstDesc(Kind == RK_IntegerXor, I); | |||
5221 | case Instruction::FMul: | |||
5222 | return ReductionInstDesc(Kind == RK_FloatMult && FastMath, I); | |||
5223 | case Instruction::FSub: | |||
5224 | case Instruction::FAdd: | |||
5225 | return ReductionInstDesc(Kind == RK_FloatAdd && FastMath, I); | |||
5226 | case Instruction::FCmp: | |||
5227 | case Instruction::ICmp: | |||
5228 | case Instruction::Select: | |||
5229 | if (Kind != RK_IntegerMinMax && | |||
5230 | (!HasFunNoNaNAttr || Kind != RK_FloatMinMax)) | |||
5231 | return ReductionInstDesc(false, I); | |||
5232 | return isMinMaxSelectCmpPattern(I, Prev); | |||
5233 | } | |||
5234 | } | |||
5235 | ||||
5236 | LoopVectorizationLegality::InductionKind | |||
5237 | LoopVectorizationLegality::isInductionVariable(PHINode *Phi) { | |||
5238 | Type *PhiTy = Phi->getType(); | |||
5239 | // We only handle integer and pointer inductions variables. | |||
5240 | if (!PhiTy->isIntegerTy() && !PhiTy->isPointerTy()) | |||
5241 | return IK_NoInduction; | |||
5242 | ||||
5243 | // Check that the PHI is consecutive. | |||
5244 | const SCEV *PhiScev = SE->getSCEV(Phi); | |||
5245 | const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(PhiScev); | |||
5246 | if (!AR) { | |||
5247 | DEBUG(dbgs() << "LV: PHI is not a poly recurrence.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: PHI is not a poly recurrence.\n" ; } } while (0); | |||
5248 | return IK_NoInduction; | |||
5249 | } | |||
5250 | const SCEV *Step = AR->getStepRecurrence(*SE); | |||
5251 | ||||
5252 | // Integer inductions need to have a stride of one. | |||
5253 | if (PhiTy->isIntegerTy()) { | |||
5254 | if (Step->isOne()) | |||
5255 | return IK_IntInduction; | |||
5256 | if (Step->isAllOnesValue()) | |||
5257 | return IK_ReverseIntInduction; | |||
5258 | return IK_NoInduction; | |||
5259 | } | |||
5260 | ||||
5261 | // Calculate the pointer stride and check if it is consecutive. | |||
5262 | const SCEVConstant *C = dyn_cast<SCEVConstant>(Step); | |||
5263 | if (!C) | |||
5264 | return IK_NoInduction; | |||
5265 | ||||
5266 | assert(PhiTy->isPointerTy() && "The PHI must be a pointer")((PhiTy->isPointerTy() && "The PHI must be a pointer" ) ? static_cast<void> (0) : __assert_fail ("PhiTy->isPointerTy() && \"The PHI must be a pointer\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 5266, __PRETTY_FUNCTION__)); | |||
5267 | uint64_t Size = DL->getTypeAllocSize(PhiTy->getPointerElementType()); | |||
5268 | if (C->getValue()->equalsInt(Size)) | |||
5269 | return IK_PtrInduction; | |||
5270 | else if (C->getValue()->equalsInt(0 - Size)) | |||
5271 | return IK_ReversePtrInduction; | |||
5272 | ||||
5273 | return IK_NoInduction; | |||
5274 | } | |||
5275 | ||||
5276 | bool LoopVectorizationLegality::isInductionVariable(const Value *V) { | |||
5277 | Value *In0 = const_cast<Value*>(V); | |||
5278 | PHINode *PN = dyn_cast_or_null<PHINode>(In0); | |||
5279 | if (!PN) | |||
5280 | return false; | |||
5281 | ||||
5282 | return Inductions.count(PN); | |||
5283 | } | |||
5284 | ||||
5285 | bool LoopVectorizationLegality::blockNeedsPredication(BasicBlock *BB) { | |||
5286 | assert(TheLoop->contains(BB) && "Unknown block used")((TheLoop->contains(BB) && "Unknown block used") ? static_cast<void> (0) : __assert_fail ("TheLoop->contains(BB) && \"Unknown block used\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 5286, __PRETTY_FUNCTION__)); | |||
5287 | ||||
5288 | // Blocks that do not dominate the latch need predication. | |||
5289 | BasicBlock* Latch = TheLoop->getLoopLatch(); | |||
5290 | return !DT->dominates(BB, Latch); | |||
5291 | } | |||
5292 | ||||
5293 | bool LoopVectorizationLegality::blockCanBePredicated(BasicBlock *BB, | |||
5294 | SmallPtrSetImpl<Value *> &SafePtrs) { | |||
5295 | for (BasicBlock::iterator it = BB->begin(), e = BB->end(); it != e; ++it) { | |||
5296 | // We might be able to hoist the load. | |||
5297 | if (it->mayReadFromMemory()) { | |||
5298 | LoadInst *LI = dyn_cast<LoadInst>(it); | |||
5299 | if (!LI || !SafePtrs.count(LI->getPointerOperand())) | |||
5300 | return false; | |||
5301 | } | |||
5302 | ||||
5303 | // We don't predicate stores at the moment. | |||
5304 | if (it->mayWriteToMemory()) { | |||
5305 | StoreInst *SI = dyn_cast<StoreInst>(it); | |||
5306 | // We only support predication of stores in basic blocks with one | |||
5307 | // predecessor. | |||
5308 | if (!SI || ++NumPredStores > NumberOfStoresToPredicate || | |||
5309 | !SafePtrs.count(SI->getPointerOperand()) || | |||
5310 | !SI->getParent()->getSinglePredecessor()) | |||
5311 | return false; | |||
5312 | } | |||
5313 | if (it->mayThrow()) | |||
5314 | return false; | |||
5315 | ||||
5316 | // Check that we don't have a constant expression that can trap as operand. | |||
5317 | for (Instruction::op_iterator OI = it->op_begin(), OE = it->op_end(); | |||
5318 | OI != OE; ++OI) { | |||
5319 | if (Constant *C = dyn_cast<Constant>(*OI)) | |||
5320 | if (C->canTrap()) | |||
5321 | return false; | |||
5322 | } | |||
5323 | ||||
5324 | // The instructions below can trap. | |||
5325 | switch (it->getOpcode()) { | |||
5326 | default: continue; | |||
5327 | case Instruction::UDiv: | |||
5328 | case Instruction::SDiv: | |||
5329 | case Instruction::URem: | |||
5330 | case Instruction::SRem: | |||
5331 | return false; | |||
5332 | } | |||
5333 | } | |||
5334 | ||||
5335 | return true; | |||
5336 | } | |||
5337 | ||||
5338 | LoopVectorizationCostModel::VectorizationFactor | |||
5339 | LoopVectorizationCostModel::selectVectorizationFactor(bool OptForSize) { | |||
5340 | // Width 1 means no vectorize | |||
5341 | VectorizationFactor Factor = { 1U, 0U }; | |||
5342 | if (OptForSize && Legal->getRuntimePointerCheck()->Need) { | |||
5343 | emitAnalysis(Report() << "runtime pointer checks needed. Enable vectorization of this loop with '#pragma clang loop vectorize(enable)' when compiling with -Os"); | |||
5344 | DEBUG(dbgs() << "LV: Aborting. Runtime ptr check is required in Os.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Aborting. Runtime ptr check is required in Os.\n" ; } } while (0); | |||
5345 | return Factor; | |||
5346 | } | |||
5347 | ||||
5348 | if (!EnableCondStoresVectorization && Legal->NumPredStores) { | |||
5349 | emitAnalysis(Report() << "store that is conditionally executed prevents vectorization"); | |||
5350 | DEBUG(dbgs() << "LV: No vectorization. There are conditional stores.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: No vectorization. There are conditional stores.\n" ; } } while (0); | |||
5351 | return Factor; | |||
5352 | } | |||
5353 | ||||
5354 | // Find the trip count. | |||
5355 | unsigned TC = SE->getSmallConstantTripCount(TheLoop, TheLoop->getLoopLatch()); | |||
5356 | DEBUG(dbgs() << "LV: Found trip count: " << TC << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found trip count: " << TC << '\n'; } } while (0); | |||
5357 | ||||
5358 | unsigned WidestType = getWidestType(); | |||
5359 | unsigned WidestRegister = TTI.getRegisterBitWidth(true); | |||
5360 | unsigned MaxSafeDepDist = -1U; | |||
5361 | if (Legal->getMaxSafeDepDistBytes() != -1U) | |||
5362 | MaxSafeDepDist = Legal->getMaxSafeDepDistBytes() * 8; | |||
5363 | WidestRegister = ((WidestRegister < MaxSafeDepDist) ? | |||
5364 | WidestRegister : MaxSafeDepDist); | |||
5365 | unsigned MaxVectorSize = WidestRegister / WidestType; | |||
5366 | DEBUG(dbgs() << "LV: The Widest type: " << WidestType << " bits.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: The Widest type: " << WidestType << " bits.\n"; } } while (0); | |||
5367 | DEBUG(dbgs() << "LV: The Widest register is: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: The Widest register is: " << WidestRegister << " bits.\n"; } } while (0) | |||
5368 | << WidestRegister << " bits.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: The Widest register is: " << WidestRegister << " bits.\n"; } } while (0); | |||
5369 | ||||
5370 | if (MaxVectorSize == 0) { | |||
5371 | DEBUG(dbgs() << "LV: The target has no vector registers.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: The target has no vector registers.\n" ; } } while (0); | |||
5372 | MaxVectorSize = 1; | |||
5373 | } | |||
5374 | ||||
5375 | assert(MaxVectorSize <= 32 && "Did not expect to pack so many elements"((MaxVectorSize <= 32 && "Did not expect to pack so many elements" " into one vector!") ? static_cast<void> (0) : __assert_fail ("MaxVectorSize <= 32 && \"Did not expect to pack so many elements\" \" into one vector!\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 5376, __PRETTY_FUNCTION__)) | |||
5376 | " into one vector!")((MaxVectorSize <= 32 && "Did not expect to pack so many elements" " into one vector!") ? static_cast<void> (0) : __assert_fail ("MaxVectorSize <= 32 && \"Did not expect to pack so many elements\" \" into one vector!\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 5376, __PRETTY_FUNCTION__)); | |||
5377 | ||||
5378 | unsigned VF = MaxVectorSize; | |||
5379 | ||||
5380 | // If we optimize the program for size, avoid creating the tail loop. | |||
5381 | if (OptForSize) { | |||
5382 | // If we are unable to calculate the trip count then don't try to vectorize. | |||
5383 | if (TC < 2) { | |||
5384 | emitAnalysis(Report() << "unable to calculate the loop count due to complex control flow"); | |||
5385 | DEBUG(dbgs() << "LV: Aborting. A tail loop is required in Os.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Aborting. A tail loop is required in Os.\n" ; } } while (0); | |||
5386 | return Factor; | |||
5387 | } | |||
5388 | ||||
5389 | // Find the maximum SIMD width that can fit within the trip count. | |||
5390 | VF = TC % MaxVectorSize; | |||
5391 | ||||
5392 | if (VF == 0) | |||
5393 | VF = MaxVectorSize; | |||
5394 | ||||
5395 | // If the trip count that we found modulo the vectorization factor is not | |||
5396 | // zero then we require a tail. | |||
5397 | if (VF < 2) { | |||
5398 | emitAnalysis(Report() << "cannot optimize for size and vectorize at the same time. Enable vectorization of this loop with '#pragma clang loop vectorize(enable)' when compiling with -Os"); | |||
5399 | DEBUG(dbgs() << "LV: Aborting. A tail loop is required in Os.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Aborting. A tail loop is required in Os.\n" ; } } while (0); | |||
5400 | return Factor; | |||
5401 | } | |||
5402 | } | |||
5403 | ||||
5404 | int UserVF = Hints->getWidth(); | |||
5405 | if (UserVF != 0) { | |||
5406 | assert(isPowerOf2_32(UserVF) && "VF needs to be a power of two")((isPowerOf2_32(UserVF) && "VF needs to be a power of two" ) ? static_cast<void> (0) : __assert_fail ("isPowerOf2_32(UserVF) && \"VF needs to be a power of two\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 5406, __PRETTY_FUNCTION__)); | |||
5407 | DEBUG(dbgs() << "LV: Using user VF " << UserVF << ".\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Using user VF " << UserVF << ".\n"; } } while (0); | |||
5408 | ||||
5409 | Factor.Width = UserVF; | |||
5410 | return Factor; | |||
5411 | } | |||
5412 | ||||
5413 | float Cost = expectedCost(1); | |||
5414 | #ifndef NDEBUG | |||
5415 | const float ScalarCost = Cost; | |||
5416 | #endif /* NDEBUG */ | |||
5417 | unsigned Width = 1; | |||
5418 | DEBUG(dbgs() << "LV: Scalar loop costs: " << (int)ScalarCost << ".\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Scalar loop costs: " << (int)ScalarCost << ".\n"; } } while (0); | |||
5419 | ||||
5420 | bool ForceVectorization = Hints->getForce() == LoopVectorizeHints::FK_Enabled; | |||
5421 | // Ignore scalar width, because the user explicitly wants vectorization. | |||
5422 | if (ForceVectorization && VF > 1) { | |||
5423 | Width = 2; | |||
5424 | Cost = expectedCost(Width) / (float)Width; | |||
5425 | } | |||
5426 | ||||
5427 | for (unsigned i=2; i <= VF; i*=2) { | |||
5428 | // Notice that the vector loop needs to be executed less times, so | |||
5429 | // we need to divide the cost of the vector loops by the width of | |||
5430 | // the vector elements. | |||
5431 | float VectorCost = expectedCost(i) / (float)i; | |||
5432 | DEBUG(dbgs() << "LV: Vector loop of width " << i << " costs: " <<do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Vector loop of width " << i << " costs: " << (int)VectorCost << ".\n"; } } while (0) | |||
5433 | (int)VectorCost << ".\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Vector loop of width " << i << " costs: " << (int)VectorCost << ".\n"; } } while (0); | |||
5434 | if (VectorCost < Cost) { | |||
5435 | Cost = VectorCost; | |||
5436 | Width = i; | |||
5437 | } | |||
5438 | } | |||
5439 | ||||
5440 | DEBUG(if (ForceVectorization && Width > 1 && Cost >= ScalarCost) dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { if (ForceVectorization && Width > 1 && Cost >= ScalarCost) dbgs() << "LV: Vectorization seems to be not beneficial, " << "but was forced by a user.\n"; } } while (0) | |||
5441 | << "LV: Vectorization seems to be not beneficial, "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { if (ForceVectorization && Width > 1 && Cost >= ScalarCost) dbgs() << "LV: Vectorization seems to be not beneficial, " << "but was forced by a user.\n"; } } while (0) | |||
5442 | << "but was forced by a user.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { if (ForceVectorization && Width > 1 && Cost >= ScalarCost) dbgs() << "LV: Vectorization seems to be not beneficial, " << "but was forced by a user.\n"; } } while (0); | |||
5443 | DEBUG(dbgs() << "LV: Selecting VF: "<< Width << ".\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Selecting VF: "<< Width << ".\n"; } } while (0); | |||
5444 | Factor.Width = Width; | |||
5445 | Factor.Cost = Width * Cost; | |||
5446 | return Factor; | |||
5447 | } | |||
5448 | ||||
5449 | unsigned LoopVectorizationCostModel::getWidestType() { | |||
5450 | unsigned MaxWidth = 8; | |||
5451 | ||||
5452 | // For each block. | |||
5453 | for (Loop::block_iterator bb = TheLoop->block_begin(), | |||
5454 | be = TheLoop->block_end(); bb != be; ++bb) { | |||
5455 | BasicBlock *BB = *bb; | |||
5456 | ||||
5457 | // For each instruction in the loop. | |||
5458 | for (BasicBlock::iterator it = BB->begin(), e = BB->end(); it != e; ++it) { | |||
5459 | Type *T = it->getType(); | |||
5460 | ||||
5461 | // Only examine Loads, Stores and PHINodes. | |||
5462 | if (!isa<LoadInst>(it) && !isa<StoreInst>(it) && !isa<PHINode>(it)) | |||
5463 | continue; | |||
5464 | ||||
5465 | // Examine PHI nodes that are reduction variables. | |||
5466 | if (PHINode *PN = dyn_cast<PHINode>(it)) | |||
5467 | if (!Legal->getReductionVars()->count(PN)) | |||
5468 | continue; | |||
5469 | ||||
5470 | // Examine the stored values. | |||
5471 | if (StoreInst *ST = dyn_cast<StoreInst>(it)) | |||
5472 | T = ST->getValueOperand()->getType(); | |||
5473 | ||||
5474 | // Ignore loaded pointer types and stored pointer types that are not | |||
5475 | // consecutive. However, we do want to take consecutive stores/loads of | |||
5476 | // pointer vectors into account. | |||
5477 | if (T->isPointerTy() && !isConsecutiveLoadOrStore(it)) | |||
5478 | continue; | |||
5479 | ||||
5480 | MaxWidth = std::max(MaxWidth, | |||
5481 | (unsigned)DL->getTypeSizeInBits(T->getScalarType())); | |||
5482 | } | |||
5483 | } | |||
5484 | ||||
5485 | return MaxWidth; | |||
5486 | } | |||
5487 | ||||
5488 | unsigned | |||
5489 | LoopVectorizationCostModel::selectUnrollFactor(bool OptForSize, | |||
5490 | unsigned VF, | |||
5491 | unsigned LoopCost) { | |||
5492 | ||||
5493 | // -- The unroll heuristics -- | |||
5494 | // We unroll the loop in order to expose ILP and reduce the loop overhead. | |||
5495 | // There are many micro-architectural considerations that we can't predict | |||
5496 | // at this level. For example, frontend pressure (on decode or fetch) due to | |||
5497 | // code size, or the number and capabilities of the execution ports. | |||
5498 | // | |||
5499 | // We use the following heuristics to select the unroll factor: | |||
5500 | // 1. If the code has reductions, then we unroll in order to break the cross | |||
5501 | // iteration dependency. | |||
5502 | // 2. If the loop is really small, then we unroll in order to reduce the loop | |||
5503 | // overhead. | |||
5504 | // 3. We don't unroll if we think that we will spill registers to memory due | |||
5505 | // to the increased register pressure. | |||
5506 | ||||
5507 | // Use the user preference, unless 'auto' is selected. | |||
5508 | int UserUF = Hints->getInterleave(); | |||
5509 | if (UserUF != 0) | |||
| ||||
5510 | return UserUF; | |||
5511 | ||||
5512 | // When we optimize for size, we don't unroll. | |||
5513 | if (OptForSize) | |||
5514 | return 1; | |||
5515 | ||||
5516 | // We used the distance for the unroll factor. | |||
5517 | if (Legal->getMaxSafeDepDistBytes() != -1U) | |||
5518 | return 1; | |||
5519 | ||||
5520 | // Do not unroll loops with a relatively small trip count. | |||
5521 | unsigned TC = SE->getSmallConstantTripCount(TheLoop, | |||
5522 | TheLoop->getLoopLatch()); | |||
5523 | if (TC > 1 && TC < TinyTripCountUnrollThreshold) | |||
5524 | return 1; | |||
5525 | ||||
5526 | unsigned TargetNumRegisters = TTI.getNumberOfRegisters(VF > 1); | |||
5527 | DEBUG(dbgs() << "LV: The target has " << TargetNumRegisters <<do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: The target has " << TargetNumRegisters << " registers\n"; } } while (0) | |||
5528 | " registers\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: The target has " << TargetNumRegisters << " registers\n"; } } while (0); | |||
5529 | ||||
5530 | if (VF == 1) { | |||
5531 | if (ForceTargetNumScalarRegs.getNumOccurrences() > 0) | |||
5532 | TargetNumRegisters = ForceTargetNumScalarRegs; | |||
5533 | } else { | |||
5534 | if (ForceTargetNumVectorRegs.getNumOccurrences() > 0) | |||
5535 | TargetNumRegisters = ForceTargetNumVectorRegs; | |||
5536 | } | |||
5537 | ||||
5538 | LoopVectorizationCostModel::RegisterUsage R = calculateRegisterUsage(); | |||
5539 | // We divide by these constants so assume that we have at least one | |||
5540 | // instruction that uses at least one register. | |||
5541 | R.MaxLocalUsers = std::max(R.MaxLocalUsers, 1U); | |||
5542 | R.NumInstructions = std::max(R.NumInstructions, 1U); | |||
5543 | ||||
5544 | // We calculate the unroll factor using the following formula. | |||
5545 | // Subtract the number of loop invariants from the number of available | |||
5546 | // registers. These registers are used by all of the unrolled instances. | |||
5547 | // Next, divide the remaining registers by the number of registers that is | |||
5548 | // required by the loop, in order to estimate how many parallel instances | |||
5549 | // fit without causing spills. All of this is rounded down if necessary to be | |||
5550 | // a power of two. We want power of two unroll factors to simplify any | |||
5551 | // addressing operations or alignment considerations. | |||
5552 | unsigned UF = PowerOf2Floor((TargetNumRegisters - R.LoopInvariantRegs) / | |||
5553 | R.MaxLocalUsers); | |||
5554 | ||||
5555 | // Don't count the induction variable as unrolled. | |||
5556 | if (EnableIndVarRegisterHeur) | |||
5557 | UF = PowerOf2Floor((TargetNumRegisters - R.LoopInvariantRegs - 1) / | |||
5558 | std::max(1U, (R.MaxLocalUsers - 1))); | |||
5559 | ||||
5560 | // Clamp the unroll factor ranges to reasonable factors. | |||
5561 | unsigned MaxInterleaveSize = TTI.getMaxInterleaveFactor(); | |||
5562 | ||||
5563 | // Check if the user has overridden the unroll max. | |||
5564 | if (VF == 1) { | |||
5565 | if (ForceTargetMaxScalarInterleaveFactor.getNumOccurrences() > 0) | |||
5566 | MaxInterleaveSize = ForceTargetMaxScalarInterleaveFactor; | |||
5567 | } else { | |||
5568 | if (ForceTargetMaxVectorInterleaveFactor.getNumOccurrences() > 0) | |||
5569 | MaxInterleaveSize = ForceTargetMaxVectorInterleaveFactor; | |||
5570 | } | |||
5571 | ||||
5572 | // If we did not calculate the cost for VF (because the user selected the VF) | |||
5573 | // then we calculate the cost of VF here. | |||
5574 | if (LoopCost == 0) | |||
5575 | LoopCost = expectedCost(VF); | |||
5576 | ||||
5577 | // Clamp the calculated UF to be between the 1 and the max unroll factor | |||
5578 | // that the target allows. | |||
5579 | if (UF > MaxInterleaveSize) | |||
5580 | UF = MaxInterleaveSize; | |||
5581 | else if (UF < 1) | |||
5582 | UF = 1; | |||
5583 | ||||
5584 | // Unroll if we vectorized this loop and there is a reduction that could | |||
5585 | // benefit from unrolling. | |||
5586 | if (VF > 1 && Legal->getReductionVars()->size()) { | |||
5587 | DEBUG(dbgs() << "LV: Unrolling because of reductions.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Unrolling because of reductions.\n" ; } } while (0); | |||
5588 | return UF; | |||
5589 | } | |||
5590 | ||||
5591 | // Note that if we've already vectorized the loop we will have done the | |||
5592 | // runtime check and so unrolling won't require further checks. | |||
5593 | bool UnrollingRequiresRuntimePointerCheck = | |||
5594 | (VF == 1 && Legal->getRuntimePointerCheck()->Need); | |||
5595 | ||||
5596 | // We want to unroll small loops in order to reduce the loop overhead and | |||
5597 | // potentially expose ILP opportunities. | |||
5598 | DEBUG(dbgs() << "LV: Loop cost is " << LoopCost << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Loop cost is " << LoopCost << '\n'; } } while (0); | |||
5599 | if (!UnrollingRequiresRuntimePointerCheck && | |||
5600 | LoopCost < SmallLoopCost) { | |||
5601 | // We assume that the cost overhead is 1 and we use the cost model | |||
5602 | // to estimate the cost of the loop and unroll until the cost of the | |||
5603 | // loop overhead is about 5% of the cost of the loop. | |||
5604 | unsigned SmallUF = std::min(UF, (unsigned)PowerOf2Floor(SmallLoopCost / LoopCost)); | |||
| ||||
5605 | ||||
5606 | // Unroll until store/load ports (estimated by max unroll factor) are | |||
5607 | // saturated. | |||
5608 | unsigned StoresUF = UF / (Legal->NumStores ? Legal->NumStores : 1); | |||
5609 | unsigned LoadsUF = UF / (Legal->NumLoads ? Legal->NumLoads : 1); | |||
5610 | ||||
5611 | // If we have a scalar reduction (vector reductions are already dealt with | |||
5612 | // by this point), we can increase the critical path length if the loop | |||
5613 | // we're unrolling is inside another loop. Limit, by default to 2, so the | |||
5614 | // critical path only gets increased by one reduction operation. | |||
5615 | if (Legal->getReductionVars()->size() && | |||
5616 | TheLoop->getLoopDepth() > 1) { | |||
5617 | unsigned F = static_cast<unsigned>(MaxNestedScalarReductionUF); | |||
5618 | SmallUF = std::min(SmallUF, F); | |||
5619 | StoresUF = std::min(StoresUF, F); | |||
5620 | LoadsUF = std::min(LoadsUF, F); | |||
5621 | } | |||
5622 | ||||
5623 | if (EnableLoadStoreRuntimeUnroll && std::max(StoresUF, LoadsUF) > SmallUF) { | |||
5624 | DEBUG(dbgs() << "LV: Unrolling to saturate store or load ports.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Unrolling to saturate store or load ports.\n" ; } } while (0); | |||
5625 | return std::max(StoresUF, LoadsUF); | |||
5626 | } | |||
5627 | ||||
5628 | DEBUG(dbgs() << "LV: Unrolling to reduce branch cost.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Unrolling to reduce branch cost.\n" ; } } while (0); | |||
5629 | return SmallUF; | |||
5630 | } | |||
5631 | ||||
5632 | DEBUG(dbgs() << "LV: Not Unrolling.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Not Unrolling.\n"; } } while (0); | |||
5633 | return 1; | |||
5634 | } | |||
5635 | ||||
5636 | LoopVectorizationCostModel::RegisterUsage | |||
5637 | LoopVectorizationCostModel::calculateRegisterUsage() { | |||
5638 | // This function calculates the register usage by measuring the highest number | |||
5639 | // of values that are alive at a single location. Obviously, this is a very | |||
5640 | // rough estimation. We scan the loop in a topological order in order and | |||
5641 | // assign a number to each instruction. We use RPO to ensure that defs are | |||
5642 | // met before their users. We assume that each instruction that has in-loop | |||
5643 | // users starts an interval. We record every time that an in-loop value is | |||
5644 | // used, so we have a list of the first and last occurrences of each | |||
5645 | // instruction. Next, we transpose this data structure into a multi map that | |||
5646 | // holds the list of intervals that *end* at a specific location. This multi | |||
5647 | // map allows us to perform a linear search. We scan the instructions linearly | |||
5648 | // and record each time that a new interval starts, by placing it in a set. | |||
5649 | // If we find this value in the multi-map then we remove it from the set. | |||
5650 | // The max register usage is the maximum size of the set. | |||
5651 | // We also search for instructions that are defined outside the loop, but are | |||
5652 | // used inside the loop. We need this number separately from the max-interval | |||
5653 | // usage number because when we unroll, loop-invariant values do not take | |||
5654 | // more register. | |||
5655 | LoopBlocksDFS DFS(TheLoop); | |||
5656 | DFS.perform(LI); | |||
5657 | ||||
5658 | RegisterUsage R; | |||
5659 | R.NumInstructions = 0; | |||
5660 | ||||
5661 | // Each 'key' in the map opens a new interval. The values | |||
5662 | // of the map are the index of the 'last seen' usage of the | |||
5663 | // instruction that is the key. | |||
5664 | typedef DenseMap<Instruction*, unsigned> IntervalMap; | |||
5665 | // Maps instruction to its index. | |||
5666 | DenseMap<unsigned, Instruction*> IdxToInstr; | |||
5667 | // Marks the end of each interval. | |||
5668 | IntervalMap EndPoint; | |||
5669 | // Saves the list of instruction indices that are used in the loop. | |||
5670 | SmallSet<Instruction*, 8> Ends; | |||
5671 | // Saves the list of values that are used in the loop but are | |||
5672 | // defined outside the loop, such as arguments and constants. | |||
5673 | SmallPtrSet<Value*, 8> LoopInvariants; | |||
5674 | ||||
5675 | unsigned Index = 0; | |||
5676 | for (LoopBlocksDFS::RPOIterator bb = DFS.beginRPO(), | |||
5677 | be = DFS.endRPO(); bb != be; ++bb) { | |||
5678 | R.NumInstructions += (*bb)->size(); | |||
5679 | for (BasicBlock::iterator it = (*bb)->begin(), e = (*bb)->end(); it != e; | |||
5680 | ++it) { | |||
5681 | Instruction *I = it; | |||
5682 | IdxToInstr[Index++] = I; | |||
5683 | ||||
5684 | // Save the end location of each USE. | |||
5685 | for (unsigned i = 0; i < I->getNumOperands(); ++i) { | |||
5686 | Value *U = I->getOperand(i); | |||
5687 | Instruction *Instr = dyn_cast<Instruction>(U); | |||
5688 | ||||
5689 | // Ignore non-instruction values such as arguments, constants, etc. | |||
5690 | if (!Instr) continue; | |||
5691 | ||||
5692 | // If this instruction is outside the loop then record it and continue. | |||
5693 | if (!TheLoop->contains(Instr)) { | |||
5694 | LoopInvariants.insert(Instr); | |||
5695 | continue; | |||
5696 | } | |||
5697 | ||||
5698 | // Overwrite previous end points. | |||
5699 | EndPoint[Instr] = Index; | |||
5700 | Ends.insert(Instr); | |||
5701 | } | |||
5702 | } | |||
5703 | } | |||
5704 | ||||
5705 | // Saves the list of intervals that end with the index in 'key'. | |||
5706 | typedef SmallVector<Instruction*, 2> InstrList; | |||
5707 | DenseMap<unsigned, InstrList> TransposeEnds; | |||
5708 | ||||
5709 | // Transpose the EndPoints to a list of values that end at each index. | |||
5710 | for (IntervalMap::iterator it = EndPoint.begin(), e = EndPoint.end(); | |||
5711 | it != e; ++it) | |||
5712 | TransposeEnds[it->second].push_back(it->first); | |||
5713 | ||||
5714 | SmallSet<Instruction*, 8> OpenIntervals; | |||
5715 | unsigned MaxUsage = 0; | |||
5716 | ||||
5717 | ||||
5718 | DEBUG(dbgs() << "LV(REG): Calculating max register usage:\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV(REG): Calculating max register usage:\n" ; } } while (0); | |||
5719 | for (unsigned int i = 0; i < Index; ++i) { | |||
5720 | Instruction *I = IdxToInstr[i]; | |||
5721 | // Ignore instructions that are never used within the loop. | |||
5722 | if (!Ends.count(I)) continue; | |||
5723 | ||||
5724 | // Remove all of the instructions that end at this location. | |||
5725 | InstrList &List = TransposeEnds[i]; | |||
5726 | for (unsigned int j=0, e = List.size(); j < e; ++j) | |||
5727 | OpenIntervals.erase(List[j]); | |||
5728 | ||||
5729 | // Count the number of live interals. | |||
5730 | MaxUsage = std::max(MaxUsage, OpenIntervals.size()); | |||
5731 | ||||
5732 | DEBUG(dbgs() << "LV(REG): At #" << i << " Interval # " <<do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV(REG): At #" << i << " Interval # " << OpenIntervals.size() << '\n'; } } while (0) | |||
5733 | OpenIntervals.size() << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV(REG): At #" << i << " Interval # " << OpenIntervals.size() << '\n'; } } while (0); | |||
5734 | ||||
5735 | // Add the current instruction to the list of open intervals. | |||
5736 | OpenIntervals.insert(I); | |||
5737 | } | |||
5738 | ||||
5739 | unsigned Invariant = LoopInvariants.size(); | |||
5740 | DEBUG(dbgs() << "LV(REG): Found max usage: " << MaxUsage << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV(REG): Found max usage: " << MaxUsage << '\n'; } } while (0); | |||
5741 | DEBUG(dbgs() << "LV(REG): Found invariant usage: " << Invariant << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV(REG): Found invariant usage: " << Invariant << '\n'; } } while (0); | |||
5742 | DEBUG(dbgs() << "LV(REG): LoopSize: " << R.NumInstructions << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV(REG): LoopSize: " << R.NumInstructions << '\n'; } } while (0); | |||
5743 | ||||
5744 | R.LoopInvariantRegs = Invariant; | |||
5745 | R.MaxLocalUsers = MaxUsage; | |||
5746 | return R; | |||
5747 | } | |||
5748 | ||||
5749 | unsigned LoopVectorizationCostModel::expectedCost(unsigned VF) { | |||
5750 | unsigned Cost = 0; | |||
5751 | ||||
5752 | // For each block. | |||
5753 | for (Loop::block_iterator bb = TheLoop->block_begin(), | |||
5754 | be = TheLoop->block_end(); bb != be; ++bb) { | |||
5755 | unsigned BlockCost = 0; | |||
5756 | BasicBlock *BB = *bb; | |||
5757 | ||||
5758 | // For each instruction in the old loop. | |||
5759 | for (BasicBlock::iterator it = BB->begin(), e = BB->end(); it != e; ++it) { | |||
5760 | // Skip dbg intrinsics. | |||
5761 | if (isa<DbgInfoIntrinsic>(it)) | |||
5762 | continue; | |||
5763 | ||||
5764 | unsigned C = getInstructionCost(it, VF); | |||
5765 | ||||
5766 | // Check if we should override the cost. | |||
5767 | if (ForceTargetInstructionCost.getNumOccurrences() > 0) | |||
5768 | C = ForceTargetInstructionCost; | |||
5769 | ||||
5770 | BlockCost += C; | |||
5771 | DEBUG(dbgs() << "LV: Found an estimated cost of " << C << " for VF " <<do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found an estimated cost of " << C << " for VF " << VF << " For instruction: " << *it << '\n'; } } while (0) | |||
5772 | VF << " For instruction: " << *it << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found an estimated cost of " << C << " for VF " << VF << " For instruction: " << *it << '\n'; } } while (0); | |||
5773 | } | |||
5774 | ||||
5775 | // We assume that if-converted blocks have a 50% chance of being executed. | |||
5776 | // When the code is scalar then some of the blocks are avoided due to CF. | |||
5777 | // When the code is vectorized we execute all code paths. | |||
5778 | if (VF == 1 && Legal->blockNeedsPredication(*bb)) | |||
5779 | BlockCost /= 2; | |||
5780 | ||||
5781 | Cost += BlockCost; | |||
5782 | } | |||
5783 | ||||
5784 | return Cost; | |||
5785 | } | |||
5786 | ||||
5787 | /// \brief Check whether the address computation for a non-consecutive memory | |||
5788 | /// access looks like an unlikely candidate for being merged into the indexing | |||
5789 | /// mode. | |||
5790 | /// | |||
5791 | /// We look for a GEP which has one index that is an induction variable and all | |||
5792 | /// other indices are loop invariant. If the stride of this access is also | |||
5793 | /// within a small bound we decide that this address computation can likely be | |||
5794 | /// merged into the addressing mode. | |||
5795 | /// In all other cases, we identify the address computation as complex. | |||
5796 | static bool isLikelyComplexAddressComputation(Value *Ptr, | |||
5797 | LoopVectorizationLegality *Legal, | |||
5798 | ScalarEvolution *SE, | |||
5799 | const Loop *TheLoop) { | |||
5800 | GetElementPtrInst *Gep = dyn_cast<GetElementPtrInst>(Ptr); | |||
5801 | if (!Gep) | |||
5802 | return true; | |||
5803 | ||||
5804 | // We are looking for a gep with all loop invariant indices except for one | |||
5805 | // which should be an induction variable. | |||
5806 | unsigned NumOperands = Gep->getNumOperands(); | |||
5807 | for (unsigned i = 1; i < NumOperands; ++i) { | |||
5808 | Value *Opd = Gep->getOperand(i); | |||
5809 | if (!SE->isLoopInvariant(SE->getSCEV(Opd), TheLoop) && | |||
5810 | !Legal->isInductionVariable(Opd)) | |||
5811 | return true; | |||
5812 | } | |||
5813 | ||||
5814 | // Now we know we have a GEP ptr, %inv, %ind, %inv. Make sure that the step | |||
5815 | // can likely be merged into the address computation. | |||
5816 | unsigned MaxMergeDistance = 64; | |||
5817 | ||||
5818 | const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(SE->getSCEV(Ptr)); | |||
5819 | if (!AddRec) | |||
5820 | return true; | |||
5821 | ||||
5822 | // Check the step is constant. | |||
5823 | const SCEV *Step = AddRec->getStepRecurrence(*SE); | |||
5824 | // Calculate the pointer stride and check if it is consecutive. | |||
5825 | const SCEVConstant *C = dyn_cast<SCEVConstant>(Step); | |||
5826 | if (!C) | |||
5827 | return true; | |||
5828 | ||||
5829 | const APInt &APStepVal = C->getValue()->getValue(); | |||
5830 | ||||
5831 | // Huge step value - give up. | |||
5832 | if (APStepVal.getBitWidth() > 64) | |||
5833 | return true; | |||
5834 | ||||
5835 | int64_t StepVal = APStepVal.getSExtValue(); | |||
5836 | ||||
5837 | return StepVal > MaxMergeDistance; | |||
5838 | } | |||
5839 | ||||
5840 | static bool isStrideMul(Instruction *I, LoopVectorizationLegality *Legal) { | |||
5841 | if (Legal->hasStride(I->getOperand(0)) || Legal->hasStride(I->getOperand(1))) | |||
5842 | return true; | |||
5843 | return false; | |||
5844 | } | |||
5845 | ||||
5846 | unsigned | |||
5847 | LoopVectorizationCostModel::getInstructionCost(Instruction *I, unsigned VF) { | |||
5848 | // If we know that this instruction will remain uniform, check the cost of | |||
5849 | // the scalar version. | |||
5850 | if (Legal->isUniformAfterVectorization(I)) | |||
5851 | VF = 1; | |||
5852 | ||||
5853 | Type *RetTy = I->getType(); | |||
5854 | Type *VectorTy = ToVectorTy(RetTy, VF); | |||
5855 | ||||
5856 | // TODO: We need to estimate the cost of intrinsic calls. | |||
5857 | switch (I->getOpcode()) { | |||
5858 | case Instruction::GetElementPtr: | |||
5859 | // We mark this instruction as zero-cost because the cost of GEPs in | |||
5860 | // vectorized code depends on whether the corresponding memory instruction | |||
5861 | // is scalarized or not. Therefore, we handle GEPs with the memory | |||
5862 | // instruction cost. | |||
5863 | return 0; | |||
5864 | case Instruction::Br: { | |||
5865 | return TTI.getCFInstrCost(I->getOpcode()); | |||
5866 | } | |||
5867 | case Instruction::PHI: | |||
5868 | //TODO: IF-converted IFs become selects. | |||
5869 | return 0; | |||
5870 | case Instruction::Add: | |||
5871 | case Instruction::FAdd: | |||
5872 | case Instruction::Sub: | |||
5873 | case Instruction::FSub: | |||
5874 | case Instruction::Mul: | |||
5875 | case Instruction::FMul: | |||
5876 | case Instruction::UDiv: | |||
5877 | case Instruction::SDiv: | |||
5878 | case Instruction::FDiv: | |||
5879 | case Instruction::URem: | |||
5880 | case Instruction::SRem: | |||
5881 | case Instruction::FRem: | |||
5882 | case Instruction::Shl: | |||
5883 | case Instruction::LShr: | |||
5884 | case Instruction::AShr: | |||
5885 | case Instruction::And: | |||
5886 | case Instruction::Or: | |||
5887 | case Instruction::Xor: { | |||
5888 | // Since we will replace the stride by 1 the multiplication should go away. | |||
5889 | if (I->getOpcode() == Instruction::Mul && isStrideMul(I, Legal)) | |||
5890 | return 0; | |||
5891 | // Certain instructions can be cheaper to vectorize if they have a constant | |||
5892 | // second vector operand. One example of this are shifts on x86. | |||
5893 | TargetTransformInfo::OperandValueKind Op1VK = | |||
5894 | TargetTransformInfo::OK_AnyValue; | |||
5895 | TargetTransformInfo::OperandValueKind Op2VK = | |||
5896 | TargetTransformInfo::OK_AnyValue; | |||
5897 | TargetTransformInfo::OperandValueProperties Op1VP = | |||
5898 | TargetTransformInfo::OP_None; | |||
5899 | TargetTransformInfo::OperandValueProperties Op2VP = | |||
5900 | TargetTransformInfo::OP_None; | |||
5901 | Value *Op2 = I->getOperand(1); | |||
5902 | ||||
5903 | // Check for a splat of a constant or for a non uniform vector of constants. | |||
5904 | if (isa<ConstantInt>(Op2)) { | |||
5905 | ConstantInt *CInt = cast<ConstantInt>(Op2); | |||
5906 | if (CInt && CInt->getValue().isPowerOf2()) | |||
5907 | Op2VP = TargetTransformInfo::OP_PowerOf2; | |||
5908 | Op2VK = TargetTransformInfo::OK_UniformConstantValue; | |||
5909 | } else if (isa<ConstantVector>(Op2) || isa<ConstantDataVector>(Op2)) { | |||
5910 | Op2VK = TargetTransformInfo::OK_NonUniformConstantValue; | |||
5911 | Constant *SplatValue = cast<Constant>(Op2)->getSplatValue(); | |||
5912 | if (SplatValue) { | |||
5913 | ConstantInt *CInt = dyn_cast<ConstantInt>(SplatValue); | |||
5914 | if (CInt && CInt->getValue().isPowerOf2()) | |||
5915 | Op2VP = TargetTransformInfo::OP_PowerOf2; | |||
5916 | Op2VK = TargetTransformInfo::OK_UniformConstantValue; | |||
5917 | } | |||
5918 | } | |||
5919 | ||||
5920 | return TTI.getArithmeticInstrCost(I->getOpcode(), VectorTy, Op1VK, Op2VK, | |||
5921 | Op1VP, Op2VP); | |||
5922 | } | |||
5923 | case Instruction::Select: { | |||
5924 | SelectInst *SI = cast<SelectInst>(I); | |||
5925 | const SCEV *CondSCEV = SE->getSCEV(SI->getCondition()); | |||
5926 | bool ScalarCond = (SE->isLoopInvariant(CondSCEV, TheLoop)); | |||
5927 | Type *CondTy = SI->getCondition()->getType(); | |||
5928 | if (!ScalarCond) | |||
5929 | CondTy = VectorType::get(CondTy, VF); | |||
5930 | ||||
5931 | return TTI.getCmpSelInstrCost(I->getOpcode(), VectorTy, CondTy); | |||
5932 | } | |||
5933 | case Instruction::ICmp: | |||
5934 | case Instruction::FCmp: { | |||
5935 | Type *ValTy = I->getOperand(0)->getType(); | |||
5936 | VectorTy = ToVectorTy(ValTy, VF); | |||
5937 | return TTI.getCmpSelInstrCost(I->getOpcode(), VectorTy); | |||
5938 | } | |||
5939 | case Instruction::Store: | |||
5940 | case Instruction::Load: { | |||
5941 | StoreInst *SI = dyn_cast<StoreInst>(I); | |||
5942 | LoadInst *LI = dyn_cast<LoadInst>(I); | |||
5943 | Type *ValTy = (SI ? SI->getValueOperand()->getType() : | |||
5944 | LI->getType()); | |||
5945 | VectorTy = ToVectorTy(ValTy, VF); | |||
5946 | ||||
5947 | unsigned Alignment = SI ? SI->getAlignment() : LI->getAlignment(); | |||
5948 | unsigned AS = SI ? SI->getPointerAddressSpace() : | |||
5949 | LI->getPointerAddressSpace(); | |||
5950 | Value *Ptr = SI ? SI->getPointerOperand() : LI->getPointerOperand(); | |||
5951 | // We add the cost of address computation here instead of with the gep | |||
5952 | // instruction because only here we know whether the operation is | |||
5953 | // scalarized. | |||
5954 | if (VF == 1) | |||
5955 | return TTI.getAddressComputationCost(VectorTy) + | |||
5956 | TTI.getMemoryOpCost(I->getOpcode(), VectorTy, Alignment, AS); | |||
5957 | ||||
5958 | // Scalarized loads/stores. | |||
5959 | int ConsecutiveStride = Legal->isConsecutivePtr(Ptr); | |||
5960 | bool Reverse = ConsecutiveStride < 0; | |||
5961 | unsigned ScalarAllocatedSize = DL->getTypeAllocSize(ValTy); | |||
5962 | unsigned VectorElementSize = DL->getTypeStoreSize(VectorTy)/VF; | |||
5963 | if (!ConsecutiveStride || ScalarAllocatedSize != VectorElementSize) { | |||
5964 | bool IsComplexComputation = | |||
5965 | isLikelyComplexAddressComputation(Ptr, Legal, SE, TheLoop); | |||
5966 | unsigned Cost = 0; | |||
5967 | // The cost of extracting from the value vector and pointer vector. | |||
5968 | Type *PtrTy = ToVectorTy(Ptr->getType(), VF); | |||
5969 | for (unsigned i = 0; i < VF; ++i) { | |||
5970 | // The cost of extracting the pointer operand. | |||
5971 | Cost += TTI.getVectorInstrCost(Instruction::ExtractElement, PtrTy, i); | |||
5972 | // In case of STORE, the cost of ExtractElement from the vector. | |||
5973 | // In case of LOAD, the cost of InsertElement into the returned | |||
5974 | // vector. | |||
5975 | Cost += TTI.getVectorInstrCost(SI ? Instruction::ExtractElement : | |||
5976 | Instruction::InsertElement, | |||
5977 | VectorTy, i); | |||
5978 | } | |||
5979 | ||||
5980 | // The cost of the scalar loads/stores. | |||
5981 | Cost += VF * TTI.getAddressComputationCost(PtrTy, IsComplexComputation); | |||
5982 | Cost += VF * TTI.getMemoryOpCost(I->getOpcode(), ValTy->getScalarType(), | |||
5983 | Alignment, AS); | |||
5984 | return Cost; | |||
5985 | } | |||
5986 | ||||
5987 | // Wide load/stores. | |||
5988 | unsigned Cost = TTI.getAddressComputationCost(VectorTy); | |||
5989 | Cost += TTI.getMemoryOpCost(I->getOpcode(), VectorTy, Alignment, AS); | |||
5990 | ||||
5991 | if (Reverse) | |||
5992 | Cost += TTI.getShuffleCost(TargetTransformInfo::SK_Reverse, | |||
5993 | VectorTy, 0); | |||
5994 | return Cost; | |||
5995 | } | |||
5996 | case Instruction::ZExt: | |||
5997 | case Instruction::SExt: | |||
5998 | case Instruction::FPToUI: | |||
5999 | case Instruction::FPToSI: | |||
6000 | case Instruction::FPExt: | |||
6001 | case Instruction::PtrToInt: | |||
6002 | case Instruction::IntToPtr: | |||
6003 | case Instruction::SIToFP: | |||
6004 | case Instruction::UIToFP: | |||
6005 | case Instruction::Trunc: | |||
6006 | case Instruction::FPTrunc: | |||
6007 | case Instruction::BitCast: { | |||
6008 | // We optimize the truncation of induction variable. | |||
6009 | // The cost of these is the same as the scalar operation. | |||
6010 | if (I->getOpcode() == Instruction::Trunc && | |||
6011 | Legal->isInductionVariable(I->getOperand(0))) | |||
6012 | return TTI.getCastInstrCost(I->getOpcode(), I->getType(), | |||
6013 | I->getOperand(0)->getType()); | |||
6014 | ||||
6015 | Type *SrcVecTy = ToVectorTy(I->getOperand(0)->getType(), VF); | |||
6016 | return TTI.getCastInstrCost(I->getOpcode(), VectorTy, SrcVecTy); | |||
6017 | } | |||
6018 | case Instruction::Call: { | |||
6019 | CallInst *CI = cast<CallInst>(I); | |||
6020 | Intrinsic::ID ID = getIntrinsicIDForCall(CI, TLI); | |||
6021 | assert(ID && "Not an intrinsic call!")((ID && "Not an intrinsic call!") ? static_cast<void > (0) : __assert_fail ("ID && \"Not an intrinsic call!\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 6021, __PRETTY_FUNCTION__)); | |||
6022 | Type *RetTy = ToVectorTy(CI->getType(), VF); | |||
6023 | SmallVector<Type*, 4> Tys; | |||
6024 | for (unsigned i = 0, ie = CI->getNumArgOperands(); i != ie; ++i) | |||
6025 | Tys.push_back(ToVectorTy(CI->getArgOperand(i)->getType(), VF)); | |||
6026 | return TTI.getIntrinsicInstrCost(ID, RetTy, Tys); | |||
6027 | } | |||
6028 | default: { | |||
6029 | // We are scalarizing the instruction. Return the cost of the scalar | |||
6030 | // instruction, plus the cost of insert and extract into vector | |||
6031 | // elements, times the vector width. | |||
6032 | unsigned Cost = 0; | |||
6033 | ||||
6034 | if (!RetTy->isVoidTy() && VF != 1) { | |||
6035 | unsigned InsCost = TTI.getVectorInstrCost(Instruction::InsertElement, | |||
6036 | VectorTy); | |||
6037 | unsigned ExtCost = TTI.getVectorInstrCost(Instruction::ExtractElement, | |||
6038 | VectorTy); | |||
6039 | ||||
6040 | // The cost of inserting the results plus extracting each one of the | |||
6041 | // operands. | |||
6042 | Cost += VF * (InsCost + ExtCost * I->getNumOperands()); | |||
6043 | } | |||
6044 | ||||
6045 | // The cost of executing VF copies of the scalar instruction. This opcode | |||
6046 | // is unknown. Assume that it is the same as 'mul'. | |||
6047 | Cost += VF * TTI.getArithmeticInstrCost(Instruction::Mul, VectorTy); | |||
6048 | return Cost; | |||
6049 | } | |||
6050 | }// end of switch. | |||
6051 | } | |||
6052 | ||||
6053 | Type* LoopVectorizationCostModel::ToVectorTy(Type *Scalar, unsigned VF) { | |||
6054 | if (Scalar->isVoidTy() || VF == 1) | |||
6055 | return Scalar; | |||
6056 | return VectorType::get(Scalar, VF); | |||
6057 | } | |||
6058 | ||||
6059 | char LoopVectorize::ID = 0; | |||
6060 | static const char lv_name[] = "Loop Vectorization"; | |||
6061 | INITIALIZE_PASS_BEGIN(LoopVectorize, LV_NAME, lv_name, false, false)static void* initializeLoopVectorizePassOnce(PassRegistry & Registry) { | |||
6062 | INITIALIZE_AG_DEPENDENCY(TargetTransformInfo)initializeTargetTransformInfoAnalysisGroup(Registry); | |||
6063 | INITIALIZE_AG_DEPENDENCY(AliasAnalysis)initializeAliasAnalysisAnalysisGroup(Registry); | |||
6064 | INITIALIZE_PASS_DEPENDENCY(BlockFrequencyInfo)initializeBlockFrequencyInfoPass(Registry); | |||
6065 | INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)initializeDominatorTreeWrapperPassPass(Registry); | |||
6066 | INITIALIZE_PASS_DEPENDENCY(ScalarEvolution)initializeScalarEvolutionPass(Registry); | |||
6067 | INITIALIZE_PASS_DEPENDENCY(LCSSA)initializeLCSSAPass(Registry); | |||
6068 | INITIALIZE_PASS_DEPENDENCY(LoopInfo)initializeLoopInfoPass(Registry); | |||
6069 | INITIALIZE_PASS_DEPENDENCY(LoopSimplify)initializeLoopSimplifyPass(Registry); | |||
6070 | INITIALIZE_PASS_END(LoopVectorize, LV_NAME, lv_name, false, false)PassInfo *PI = new PassInfo(lv_name, "loop-vectorize", & LoopVectorize ::ID, PassInfo::NormalCtor_t(callDefaultCtor< LoopVectorize >), false, false); Registry.registerPass(*PI, true); return PI; } void llvm::initializeLoopVectorizePass(PassRegistry & Registry) { static volatile sys::cas_flag initialized = 0; sys ::cas_flag old_val = sys::CompareAndSwap(&initialized, 1, 0); if (old_val == 0) { initializeLoopVectorizePassOnce(Registry ); sys::MemoryFence(); AnnotateIgnoreWritesBegin("/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 6070); AnnotateHappensBefore("/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 6070, &initialized); initialized = 2; AnnotateIgnoreWritesEnd ("/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 6070); } else { sys::cas_flag tmp = initialized; sys::MemoryFence (); while (tmp != 2) { tmp = initialized; sys::MemoryFence(); } } AnnotateHappensAfter("/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 6070, &initialized); } | |||
6071 | ||||
6072 | namespace llvm { | |||
6073 | Pass *createLoopVectorizePass(bool NoUnrolling, bool AlwaysVectorize) { | |||
6074 | return new LoopVectorize(NoUnrolling, AlwaysVectorize); | |||
6075 | } | |||
6076 | } | |||
6077 | ||||
6078 | bool LoopVectorizationCostModel::isConsecutiveLoadOrStore(Instruction *Inst) { | |||
6079 | // Check for a store. | |||
6080 | if (StoreInst *ST = dyn_cast<StoreInst>(Inst)) | |||
6081 | return Legal->isConsecutivePtr(ST->getPointerOperand()) != 0; | |||
6082 | ||||
6083 | // Check for a load. | |||
6084 | if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) | |||
6085 | return Legal->isConsecutivePtr(LI->getPointerOperand()) != 0; | |||
6086 | ||||
6087 | return false; | |||
6088 | } | |||
6089 | ||||
6090 | ||||
6091 | void InnerLoopUnroller::scalarizeInstruction(Instruction *Instr, | |||
6092 | bool IfPredicateStore) { | |||
6093 | assert(!Instr->getType()->isAggregateType() && "Can't handle vectors")((!Instr->getType()->isAggregateType() && "Can't handle vectors" ) ? static_cast<void> (0) : __assert_fail ("!Instr->getType()->isAggregateType() && \"Can't handle vectors\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 6093, __PRETTY_FUNCTION__)); | |||
6094 | // Holds vector parameters or scalars, in case of uniform vals. | |||
6095 | SmallVector<VectorParts, 4> Params; | |||
6096 | ||||
6097 | setDebugLocFromInst(Builder, Instr); | |||
6098 | ||||
6099 | // Find all of the vectorized parameters. | |||
6100 | for (unsigned op = 0, e = Instr->getNumOperands(); op != e; ++op) { | |||
6101 | Value *SrcOp = Instr->getOperand(op); | |||
6102 | ||||
6103 | // If we are accessing the old induction variable, use the new one. | |||
6104 | if (SrcOp == OldInduction) { | |||
6105 | Params.push_back(getVectorValue(SrcOp)); | |||
6106 | continue; | |||
6107 | } | |||
6108 | ||||
6109 | // Try using previously calculated values. | |||
6110 | Instruction *SrcInst = dyn_cast<Instruction>(SrcOp); | |||
6111 | ||||
6112 | // If the src is an instruction that appeared earlier in the basic block | |||
6113 | // then it should already be vectorized. | |||
6114 | if (SrcInst && OrigLoop->contains(SrcInst)) { | |||
6115 | assert(WidenMap.has(SrcInst) && "Source operand is unavailable")((WidenMap.has(SrcInst) && "Source operand is unavailable" ) ? static_cast<void> (0) : __assert_fail ("WidenMap.has(SrcInst) && \"Source operand is unavailable\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 6115, __PRETTY_FUNCTION__)); | |||
6116 | // The parameter is a vector value from earlier. | |||
6117 | Params.push_back(WidenMap.get(SrcInst)); | |||
6118 | } else { | |||
6119 | // The parameter is a scalar from outside the loop. Maybe even a constant. | |||
6120 | VectorParts Scalars; | |||
6121 | Scalars.append(UF, SrcOp); | |||
6122 | Params.push_back(Scalars); | |||
6123 | } | |||
6124 | } | |||
6125 | ||||
6126 | assert(Params.size() == Instr->getNumOperands() &&((Params.size() == Instr->getNumOperands() && "Invalid number of operands" ) ? static_cast<void> (0) : __assert_fail ("Params.size() == Instr->getNumOperands() && \"Invalid number of operands\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 6127, __PRETTY_FUNCTION__)) | |||
6127 | "Invalid number of operands")((Params.size() == Instr->getNumOperands() && "Invalid number of operands" ) ? static_cast<void> (0) : __assert_fail ("Params.size() == Instr->getNumOperands() && \"Invalid number of operands\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 6127, __PRETTY_FUNCTION__)); | |||
6128 | ||||
6129 | // Does this instruction return a value ? | |||
6130 | bool IsVoidRetTy = Instr->getType()->isVoidTy(); | |||
6131 | ||||
6132 | Value *UndefVec = IsVoidRetTy ? nullptr : | |||
6133 | UndefValue::get(Instr->getType()); | |||
6134 | // Create a new entry in the WidenMap and initialize it to Undef or Null. | |||
6135 | VectorParts &VecResults = WidenMap.splat(Instr, UndefVec); | |||
6136 | ||||
6137 | Instruction *InsertPt = Builder.GetInsertPoint(); | |||
6138 | BasicBlock *IfBlock = Builder.GetInsertBlock(); | |||
6139 | BasicBlock *CondBlock = nullptr; | |||
6140 | ||||
6141 | VectorParts Cond; | |||
6142 | Loop *VectorLp = nullptr; | |||
6143 | if (IfPredicateStore) { | |||
6144 | assert(Instr->getParent()->getSinglePredecessor() &&((Instr->getParent()->getSinglePredecessor() && "Only support single predecessor blocks") ? static_cast<void > (0) : __assert_fail ("Instr->getParent()->getSinglePredecessor() && \"Only support single predecessor blocks\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 6145, __PRETTY_FUNCTION__)) | |||
6145 | "Only support single predecessor blocks")((Instr->getParent()->getSinglePredecessor() && "Only support single predecessor blocks") ? static_cast<void > (0) : __assert_fail ("Instr->getParent()->getSinglePredecessor() && \"Only support single predecessor blocks\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 6145, __PRETTY_FUNCTION__)); | |||
6146 | Cond = createEdgeMask(Instr->getParent()->getSinglePredecessor(), | |||
6147 | Instr->getParent()); | |||
6148 | VectorLp = LI->getLoopFor(IfBlock); | |||
6149 | assert(VectorLp && "Must have a loop for this block")((VectorLp && "Must have a loop for this block") ? static_cast <void> (0) : __assert_fail ("VectorLp && \"Must have a loop for this block\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 6149, __PRETTY_FUNCTION__)); | |||
6150 | } | |||
6151 | ||||
6152 | // For each vector unroll 'part': | |||
6153 | for (unsigned Part = 0; Part < UF; ++Part) { | |||
6154 | // For each scalar that we create: | |||
6155 | ||||
6156 | // Start an "if (pred) a[i] = ..." block. | |||
6157 | Value *Cmp = nullptr; | |||
6158 | if (IfPredicateStore) { | |||
6159 | if (Cond[Part]->getType()->isVectorTy()) | |||
6160 | Cond[Part] = | |||
6161 | Builder.CreateExtractElement(Cond[Part], Builder.getInt32(0)); | |||
6162 | Cmp = Builder.CreateICmp(ICmpInst::ICMP_EQ, Cond[Part], | |||
6163 | ConstantInt::get(Cond[Part]->getType(), 1)); | |||
6164 | CondBlock = IfBlock->splitBasicBlock(InsertPt, "cond.store"); | |||
6165 | LoopVectorBody.push_back(CondBlock); | |||
6166 | VectorLp->addBasicBlockToLoop(CondBlock, LI->getBase()); | |||
6167 | // Update Builder with newly created basic block. | |||
6168 | Builder.SetInsertPoint(InsertPt); | |||
6169 | } | |||
6170 | ||||
6171 | Instruction *Cloned = Instr->clone(); | |||
6172 | if (!IsVoidRetTy) | |||
6173 | Cloned->setName(Instr->getName() + ".cloned"); | |||
6174 | // Replace the operands of the cloned instructions with extracted scalars. | |||
6175 | for (unsigned op = 0, e = Instr->getNumOperands(); op != e; ++op) { | |||
6176 | Value *Op = Params[op][Part]; | |||
6177 | Cloned->setOperand(op, Op); | |||
6178 | } | |||
6179 | ||||
6180 | // Place the cloned scalar in the new loop. | |||
6181 | Builder.Insert(Cloned); | |||
6182 | ||||
6183 | // If the original scalar returns a value we need to place it in a vector | |||
6184 | // so that future users will be able to use it. | |||
6185 | if (!IsVoidRetTy) | |||
6186 | VecResults[Part] = Cloned; | |||
6187 | ||||
6188 | // End if-block. | |||
6189 | if (IfPredicateStore) { | |||
6190 | BasicBlock *NewIfBlock = CondBlock->splitBasicBlock(InsertPt, "else"); | |||
6191 | LoopVectorBody.push_back(NewIfBlock); | |||
6192 | VectorLp->addBasicBlockToLoop(NewIfBlock, LI->getBase()); | |||
6193 | Builder.SetInsertPoint(InsertPt); | |||
6194 | Instruction *OldBr = IfBlock->getTerminator(); | |||
6195 | BranchInst::Create(CondBlock, NewIfBlock, Cmp, OldBr); | |||
6196 | OldBr->eraseFromParent(); | |||
6197 | IfBlock = NewIfBlock; | |||
6198 | } | |||
6199 | } | |||
6200 | } | |||
6201 | ||||
6202 | void InnerLoopUnroller::vectorizeMemoryInstruction(Instruction *Instr) { | |||
6203 | StoreInst *SI = dyn_cast<StoreInst>(Instr); | |||
6204 | bool IfPredicateStore = (SI && Legal->blockNeedsPredication(SI->getParent())); | |||
6205 | ||||
6206 | return scalarizeInstruction(Instr, IfPredicateStore); | |||
6207 | } | |||
6208 | ||||
6209 | Value *InnerLoopUnroller::reverseVector(Value *Vec) { | |||
6210 | return Vec; | |||
6211 | } | |||
6212 | ||||
6213 | Value *InnerLoopUnroller::getBroadcastInstrs(Value *V) { | |||
6214 | return V; | |||
6215 | } | |||
6216 | ||||
6217 | Value *InnerLoopUnroller::getConsecutiveVector(Value* Val, int StartIdx, | |||
6218 | bool Negate) { | |||
6219 | // When unrolling and the VF is 1, we only need to add a simple scalar. | |||
6220 | Type *ITy = Val->getType(); | |||
6221 | assert(!ITy->isVectorTy() && "Val must be a scalar")((!ITy->isVectorTy() && "Val must be a scalar") ? static_cast <void> (0) : __assert_fail ("!ITy->isVectorTy() && \"Val must be a scalar\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn219049/lib/Transforms/Vectorize/LoopVectorize.cpp" , 6221, __PRETTY_FUNCTION__)); | |||
6222 | Constant *C = ConstantInt::get(ITy, StartIdx, Negate); | |||
6223 | return Builder.CreateAdd(Val, C, "induction"); | |||
6224 | } |