| File: | lib/Transforms/Scalar/GVNHoist.cpp |
| Warning: | line 447, column 31 Called C++ object pointer is null |
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| 1 | //===- GVNHoist.cpp - Hoist scalar and load expressions -------------------===// | |||
| 2 | // | |||
| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | |||
| 4 | // See https://llvm.org/LICENSE.txt for license information. | |||
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | |||
| 6 | // | |||
| 7 | //===----------------------------------------------------------------------===// | |||
| 8 | // | |||
| 9 | // This pass hoists expressions from branches to a common dominator. It uses | |||
| 10 | // GVN (global value numbering) to discover expressions computing the same | |||
| 11 | // values. The primary goals of code-hoisting are: | |||
| 12 | // 1. To reduce the code size. | |||
| 13 | // 2. In some cases reduce critical path (by exposing more ILP). | |||
| 14 | // | |||
| 15 | // The algorithm factors out the reachability of values such that multiple | |||
| 16 | // queries to find reachability of values are fast. This is based on finding the | |||
| 17 | // ANTIC points in the CFG which do not change during hoisting. The ANTIC points | |||
| 18 | // are basically the dominance-frontiers in the inverse graph. So we introduce a | |||
| 19 | // data structure (CHI nodes) to keep track of values flowing out of a basic | |||
| 20 | // block. We only do this for values with multiple occurrences in the function | |||
| 21 | // as they are the potential hoistable candidates. This approach allows us to | |||
| 22 | // hoist instructions to a basic block with more than two successors, as well as | |||
| 23 | // deal with infinite loops in a trivial way. | |||
| 24 | // | |||
| 25 | // Limitations: This pass does not hoist fully redundant expressions because | |||
| 26 | // they are already handled by GVN-PRE. It is advisable to run gvn-hoist before | |||
| 27 | // and after gvn-pre because gvn-pre creates opportunities for more instructions | |||
| 28 | // to be hoisted. | |||
| 29 | // | |||
| 30 | // Hoisting may affect the performance in some cases. To mitigate that, hoisting | |||
| 31 | // is disabled in the following cases. | |||
| 32 | // 1. Scalars across calls. | |||
| 33 | // 2. geps when corresponding load/store cannot be hoisted. | |||
| 34 | //===----------------------------------------------------------------------===// | |||
| 35 | ||||
| 36 | #include "llvm/ADT/DenseMap.h" | |||
| 37 | #include "llvm/ADT/DenseSet.h" | |||
| 38 | #include "llvm/ADT/STLExtras.h" | |||
| 39 | #include "llvm/ADT/SmallPtrSet.h" | |||
| 40 | #include "llvm/ADT/SmallVector.h" | |||
| 41 | #include "llvm/ADT/Statistic.h" | |||
| 42 | #include "llvm/ADT/iterator_range.h" | |||
| 43 | #include "llvm/Analysis/AliasAnalysis.h" | |||
| 44 | #include "llvm/Analysis/GlobalsModRef.h" | |||
| 45 | #include "llvm/Analysis/IteratedDominanceFrontier.h" | |||
| 46 | #include "llvm/Analysis/MemoryDependenceAnalysis.h" | |||
| 47 | #include "llvm/Analysis/MemorySSA.h" | |||
| 48 | #include "llvm/Analysis/MemorySSAUpdater.h" | |||
| 49 | #include "llvm/Analysis/PostDominators.h" | |||
| 50 | #include "llvm/Transforms/Utils/Local.h" | |||
| 51 | #include "llvm/Analysis/ValueTracking.h" | |||
| 52 | #include "llvm/IR/Argument.h" | |||
| 53 | #include "llvm/IR/BasicBlock.h" | |||
| 54 | #include "llvm/IR/CFG.h" | |||
| 55 | #include "llvm/IR/Constants.h" | |||
| 56 | #include "llvm/IR/Dominators.h" | |||
| 57 | #include "llvm/IR/Function.h" | |||
| 58 | #include "llvm/IR/InstrTypes.h" | |||
| 59 | #include "llvm/IR/Instruction.h" | |||
| 60 | #include "llvm/IR/Instructions.h" | |||
| 61 | #include "llvm/IR/IntrinsicInst.h" | |||
| 62 | #include "llvm/IR/Intrinsics.h" | |||
| 63 | #include "llvm/IR/LLVMContext.h" | |||
| 64 | #include "llvm/IR/PassManager.h" | |||
| 65 | #include "llvm/IR/Use.h" | |||
| 66 | #include "llvm/IR/User.h" | |||
| 67 | #include "llvm/IR/Value.h" | |||
| 68 | #include "llvm/Pass.h" | |||
| 69 | #include "llvm/Support/Casting.h" | |||
| 70 | #include "llvm/Support/CommandLine.h" | |||
| 71 | #include "llvm/Support/Debug.h" | |||
| 72 | #include "llvm/Support/raw_ostream.h" | |||
| 73 | #include "llvm/Transforms/Scalar.h" | |||
| 74 | #include "llvm/Transforms/Scalar/GVN.h" | |||
| 75 | #include <algorithm> | |||
| 76 | #include <cassert> | |||
| 77 | #include <iterator> | |||
| 78 | #include <memory> | |||
| 79 | #include <utility> | |||
| 80 | #include <vector> | |||
| 81 | ||||
| 82 | using namespace llvm; | |||
| 83 | ||||
| 84 | #define DEBUG_TYPE"gvn-hoist" "gvn-hoist" | |||
| 85 | ||||
| 86 | STATISTIC(NumHoisted, "Number of instructions hoisted")static llvm::Statistic NumHoisted = {"gvn-hoist", "NumHoisted" , "Number of instructions hoisted"}; | |||
| 87 | STATISTIC(NumRemoved, "Number of instructions removed")static llvm::Statistic NumRemoved = {"gvn-hoist", "NumRemoved" , "Number of instructions removed"}; | |||
| 88 | STATISTIC(NumLoadsHoisted, "Number of loads hoisted")static llvm::Statistic NumLoadsHoisted = {"gvn-hoist", "NumLoadsHoisted" , "Number of loads hoisted"}; | |||
| 89 | STATISTIC(NumLoadsRemoved, "Number of loads removed")static llvm::Statistic NumLoadsRemoved = {"gvn-hoist", "NumLoadsRemoved" , "Number of loads removed"}; | |||
| 90 | STATISTIC(NumStoresHoisted, "Number of stores hoisted")static llvm::Statistic NumStoresHoisted = {"gvn-hoist", "NumStoresHoisted" , "Number of stores hoisted"}; | |||
| 91 | STATISTIC(NumStoresRemoved, "Number of stores removed")static llvm::Statistic NumStoresRemoved = {"gvn-hoist", "NumStoresRemoved" , "Number of stores removed"}; | |||
| 92 | STATISTIC(NumCallsHoisted, "Number of calls hoisted")static llvm::Statistic NumCallsHoisted = {"gvn-hoist", "NumCallsHoisted" , "Number of calls hoisted"}; | |||
| 93 | STATISTIC(NumCallsRemoved, "Number of calls removed")static llvm::Statistic NumCallsRemoved = {"gvn-hoist", "NumCallsRemoved" , "Number of calls removed"}; | |||
| 94 | ||||
| 95 | static cl::opt<int> | |||
| 96 | MaxHoistedThreshold("gvn-max-hoisted", cl::Hidden, cl::init(-1), | |||
| 97 | cl::desc("Max number of instructions to hoist " | |||
| 98 | "(default unlimited = -1)")); | |||
| 99 | ||||
| 100 | static cl::opt<int> MaxNumberOfBBSInPath( | |||
| 101 | "gvn-hoist-max-bbs", cl::Hidden, cl::init(4), | |||
| 102 | cl::desc("Max number of basic blocks on the path between " | |||
| 103 | "hoisting locations (default = 4, unlimited = -1)")); | |||
| 104 | ||||
| 105 | static cl::opt<int> MaxDepthInBB( | |||
| 106 | "gvn-hoist-max-depth", cl::Hidden, cl::init(100), | |||
| 107 | cl::desc("Hoist instructions from the beginning of the BB up to the " | |||
| 108 | "maximum specified depth (default = 100, unlimited = -1)")); | |||
| 109 | ||||
| 110 | static cl::opt<int> | |||
| 111 | MaxChainLength("gvn-hoist-max-chain-length", cl::Hidden, cl::init(10), | |||
| 112 | cl::desc("Maximum length of dependent chains to hoist " | |||
| 113 | "(default = 10, unlimited = -1)")); | |||
| 114 | ||||
| 115 | namespace llvm { | |||
| 116 | ||||
| 117 | using BBSideEffectsSet = DenseMap<const BasicBlock *, bool>; | |||
| 118 | using SmallVecInsn = SmallVector<Instruction *, 4>; | |||
| 119 | using SmallVecImplInsn = SmallVectorImpl<Instruction *>; | |||
| 120 | ||||
| 121 | // Each element of a hoisting list contains the basic block where to hoist and | |||
| 122 | // a list of instructions to be hoisted. | |||
| 123 | using HoistingPointInfo = std::pair<BasicBlock *, SmallVecInsn>; | |||
| 124 | ||||
| 125 | using HoistingPointList = SmallVector<HoistingPointInfo, 4>; | |||
| 126 | ||||
| 127 | // A map from a pair of VNs to all the instructions with those VNs. | |||
| 128 | using VNType = std::pair<unsigned, unsigned>; | |||
| 129 | ||||
| 130 | using VNtoInsns = DenseMap<VNType, SmallVector<Instruction *, 4>>; | |||
| 131 | ||||
| 132 | // CHI keeps information about values flowing out of a basic block. It is | |||
| 133 | // similar to PHI but in the inverse graph, and used for outgoing values on each | |||
| 134 | // edge. For conciseness, it is computed only for instructions with multiple | |||
| 135 | // occurrences in the CFG because they are the only hoistable candidates. | |||
| 136 | // A (CHI[{V, B, I1}, {V, C, I2}] | |||
| 137 | // / \ | |||
| 138 | // / \ | |||
| 139 | // B(I1) C (I2) | |||
| 140 | // The Value number for both I1 and I2 is V, the CHI node will save the | |||
| 141 | // instruction as well as the edge where the value is flowing to. | |||
| 142 | struct CHIArg { | |||
| 143 | VNType VN; | |||
| 144 | ||||
| 145 | // Edge destination (shows the direction of flow), may not be where the I is. | |||
| 146 | BasicBlock *Dest; | |||
| 147 | ||||
| 148 | // The instruction (VN) which uses the values flowing out of CHI. | |||
| 149 | Instruction *I; | |||
| 150 | ||||
| 151 | bool operator==(const CHIArg &A) { return VN == A.VN; } | |||
| 152 | bool operator!=(const CHIArg &A) { return !(*this == A); } | |||
| 153 | }; | |||
| 154 | ||||
| 155 | using CHIIt = SmallVectorImpl<CHIArg>::iterator; | |||
| 156 | using CHIArgs = iterator_range<CHIIt>; | |||
| 157 | using OutValuesType = DenseMap<BasicBlock *, SmallVector<CHIArg, 2>>; | |||
| 158 | using InValuesType = | |||
| 159 | DenseMap<BasicBlock *, SmallVector<std::pair<VNType, Instruction *>, 2>>; | |||
| 160 | ||||
| 161 | // An invalid value number Used when inserting a single value number into | |||
| 162 | // VNtoInsns. | |||
| 163 | enum : unsigned { InvalidVN = ~2U }; | |||
| 164 | ||||
| 165 | // Records all scalar instructions candidate for code hoisting. | |||
| 166 | class InsnInfo { | |||
| 167 | VNtoInsns VNtoScalars; | |||
| 168 | ||||
| 169 | public: | |||
| 170 | // Inserts I and its value number in VNtoScalars. | |||
| 171 | void insert(Instruction *I, GVN::ValueTable &VN) { | |||
| 172 | // Scalar instruction. | |||
| 173 | unsigned V = VN.lookupOrAdd(I); | |||
| 174 | VNtoScalars[{V, InvalidVN}].push_back(I); | |||
| 175 | } | |||
| 176 | ||||
| 177 | const VNtoInsns &getVNTable() const { return VNtoScalars; } | |||
| 178 | }; | |||
| 179 | ||||
| 180 | // Records all load instructions candidate for code hoisting. | |||
| 181 | class LoadInfo { | |||
| 182 | VNtoInsns VNtoLoads; | |||
| 183 | ||||
| 184 | public: | |||
| 185 | // Insert Load and the value number of its memory address in VNtoLoads. | |||
| 186 | void insert(LoadInst *Load, GVN::ValueTable &VN) { | |||
| 187 | if (Load->isSimple()) { | |||
| 188 | unsigned V = VN.lookupOrAdd(Load->getPointerOperand()); | |||
| 189 | VNtoLoads[{V, InvalidVN}].push_back(Load); | |||
| 190 | } | |||
| 191 | } | |||
| 192 | ||||
| 193 | const VNtoInsns &getVNTable() const { return VNtoLoads; } | |||
| 194 | }; | |||
| 195 | ||||
| 196 | // Records all store instructions candidate for code hoisting. | |||
| 197 | class StoreInfo { | |||
| 198 | VNtoInsns VNtoStores; | |||
| 199 | ||||
| 200 | public: | |||
| 201 | // Insert the Store and a hash number of the store address and the stored | |||
| 202 | // value in VNtoStores. | |||
| 203 | void insert(StoreInst *Store, GVN::ValueTable &VN) { | |||
| 204 | if (!Store->isSimple()) | |||
| 205 | return; | |||
| 206 | // Hash the store address and the stored value. | |||
| 207 | Value *Ptr = Store->getPointerOperand(); | |||
| 208 | Value *Val = Store->getValueOperand(); | |||
| 209 | VNtoStores[{VN.lookupOrAdd(Ptr), VN.lookupOrAdd(Val)}].push_back(Store); | |||
| 210 | } | |||
| 211 | ||||
| 212 | const VNtoInsns &getVNTable() const { return VNtoStores; } | |||
| 213 | }; | |||
| 214 | ||||
| 215 | // Records all call instructions candidate for code hoisting. | |||
| 216 | class CallInfo { | |||
| 217 | VNtoInsns VNtoCallsScalars; | |||
| 218 | VNtoInsns VNtoCallsLoads; | |||
| 219 | VNtoInsns VNtoCallsStores; | |||
| 220 | ||||
| 221 | public: | |||
| 222 | // Insert Call and its value numbering in one of the VNtoCalls* containers. | |||
| 223 | void insert(CallInst *Call, GVN::ValueTable &VN) { | |||
| 224 | // A call that doesNotAccessMemory is handled as a Scalar, | |||
| 225 | // onlyReadsMemory will be handled as a Load instruction, | |||
| 226 | // all other calls will be handled as stores. | |||
| 227 | unsigned V = VN.lookupOrAdd(Call); | |||
| 228 | auto Entry = std::make_pair(V, InvalidVN); | |||
| 229 | ||||
| 230 | if (Call->doesNotAccessMemory()) | |||
| 231 | VNtoCallsScalars[Entry].push_back(Call); | |||
| 232 | else if (Call->onlyReadsMemory()) | |||
| 233 | VNtoCallsLoads[Entry].push_back(Call); | |||
| 234 | else | |||
| 235 | VNtoCallsStores[Entry].push_back(Call); | |||
| 236 | } | |||
| 237 | ||||
| 238 | const VNtoInsns &getScalarVNTable() const { return VNtoCallsScalars; } | |||
| 239 | const VNtoInsns &getLoadVNTable() const { return VNtoCallsLoads; } | |||
| 240 | const VNtoInsns &getStoreVNTable() const { return VNtoCallsStores; } | |||
| 241 | }; | |||
| 242 | ||||
| 243 | static void combineKnownMetadata(Instruction *ReplInst, Instruction *I) { | |||
| 244 | static const unsigned KnownIDs[] = { | |||
| 245 | LLVMContext::MD_tbaa, LLVMContext::MD_alias_scope, | |||
| 246 | LLVMContext::MD_noalias, LLVMContext::MD_range, | |||
| 247 | LLVMContext::MD_fpmath, LLVMContext::MD_invariant_load, | |||
| 248 | LLVMContext::MD_invariant_group, LLVMContext::MD_access_group}; | |||
| 249 | combineMetadata(ReplInst, I, KnownIDs, true); | |||
| 250 | } | |||
| 251 | ||||
| 252 | // This pass hoists common computations across branches sharing common | |||
| 253 | // dominator. The primary goal is to reduce the code size, and in some | |||
| 254 | // cases reduce critical path (by exposing more ILP). | |||
| 255 | class GVNHoist { | |||
| 256 | public: | |||
| 257 | GVNHoist(DominatorTree *DT, PostDominatorTree *PDT, AliasAnalysis *AA, | |||
| 258 | MemoryDependenceResults *MD, MemorySSA *MSSA) | |||
| 259 | : DT(DT), PDT(PDT), AA(AA), MD(MD), MSSA(MSSA), | |||
| 260 | MSSAUpdater(std::make_unique<MemorySSAUpdater>(MSSA)) {} | |||
| 261 | ||||
| 262 | bool run(Function &F) { | |||
| 263 | NumFuncArgs = F.arg_size(); | |||
| 264 | VN.setDomTree(DT); | |||
| 265 | VN.setAliasAnalysis(AA); | |||
| 266 | VN.setMemDep(MD); | |||
| 267 | bool Res = false; | |||
| 268 | // Perform DFS Numbering of instructions. | |||
| 269 | unsigned BBI = 0; | |||
| 270 | for (const BasicBlock *BB : depth_first(&F.getEntryBlock())) { | |||
| 271 | DFSNumber[BB] = ++BBI; | |||
| 272 | unsigned I = 0; | |||
| 273 | for (auto &Inst : *BB) | |||
| 274 | DFSNumber[&Inst] = ++I; | |||
| 275 | } | |||
| 276 | ||||
| 277 | int ChainLength = 0; | |||
| 278 | ||||
| 279 | // FIXME: use lazy evaluation of VN to avoid the fix-point computation. | |||
| 280 | while (true) { | |||
| 281 | if (MaxChainLength != -1 && ++ChainLength >= MaxChainLength) | |||
| 282 | return Res; | |||
| 283 | ||||
| 284 | auto HoistStat = hoistExpressions(F); | |||
| 285 | if (HoistStat.first + HoistStat.second == 0) | |||
| 286 | return Res; | |||
| 287 | ||||
| 288 | if (HoistStat.second > 0) | |||
| 289 | // To address a limitation of the current GVN, we need to rerun the | |||
| 290 | // hoisting after we hoisted loads or stores in order to be able to | |||
| 291 | // hoist all scalars dependent on the hoisted ld/st. | |||
| 292 | VN.clear(); | |||
| 293 | ||||
| 294 | Res = true; | |||
| 295 | } | |||
| 296 | ||||
| 297 | return Res; | |||
| 298 | } | |||
| 299 | ||||
| 300 | // Copied from NewGVN.cpp | |||
| 301 | // This function provides global ranking of operations so that we can place | |||
| 302 | // them in a canonical order. Note that rank alone is not necessarily enough | |||
| 303 | // for a complete ordering, as constants all have the same rank. However, | |||
| 304 | // generally, we will simplify an operation with all constants so that it | |||
| 305 | // doesn't matter what order they appear in. | |||
| 306 | unsigned int rank(const Value *V) const { | |||
| 307 | // Prefer constants to undef to anything else | |||
| 308 | // Undef is a constant, have to check it first. | |||
| 309 | // Prefer smaller constants to constantexprs | |||
| 310 | if (isa<ConstantExpr>(V)) | |||
| 311 | return 2; | |||
| 312 | if (isa<UndefValue>(V)) | |||
| 313 | return 1; | |||
| 314 | if (isa<Constant>(V)) | |||
| 315 | return 0; | |||
| 316 | else if (auto *A = dyn_cast<Argument>(V)) | |||
| 317 | return 3 + A->getArgNo(); | |||
| 318 | ||||
| 319 | // Need to shift the instruction DFS by number of arguments + 3 to account | |||
| 320 | // for the constant and argument ranking above. | |||
| 321 | auto Result = DFSNumber.lookup(V); | |||
| 322 | if (Result > 0) | |||
| 323 | return 4 + NumFuncArgs + Result; | |||
| 324 | // Unreachable or something else, just return a really large number. | |||
| 325 | return ~0; | |||
| 326 | } | |||
| 327 | ||||
| 328 | private: | |||
| 329 | GVN::ValueTable VN; | |||
| 330 | DominatorTree *DT; | |||
| 331 | PostDominatorTree *PDT; | |||
| 332 | AliasAnalysis *AA; | |||
| 333 | MemoryDependenceResults *MD; | |||
| 334 | MemorySSA *MSSA; | |||
| 335 | std::unique_ptr<MemorySSAUpdater> MSSAUpdater; | |||
| 336 | DenseMap<const Value *, unsigned> DFSNumber; | |||
| 337 | BBSideEffectsSet BBSideEffects; | |||
| 338 | DenseSet<const BasicBlock *> HoistBarrier; | |||
| 339 | SmallVector<BasicBlock *, 32> IDFBlocks; | |||
| 340 | unsigned NumFuncArgs; | |||
| 341 | const bool HoistingGeps = false; | |||
| 342 | ||||
| 343 | enum InsKind { Unknown, Scalar, Load, Store }; | |||
| 344 | ||||
| 345 | // Return true when there are exception handling in BB. | |||
| 346 | bool hasEH(const BasicBlock *BB) { | |||
| 347 | auto It = BBSideEffects.find(BB); | |||
| 348 | if (It != BBSideEffects.end()) | |||
| 349 | return It->second; | |||
| 350 | ||||
| 351 | if (BB->isEHPad() || BB->hasAddressTaken()) { | |||
| 352 | BBSideEffects[BB] = true; | |||
| 353 | return true; | |||
| 354 | } | |||
| 355 | ||||
| 356 | if (BB->getTerminator()->mayThrow()) { | |||
| 357 | BBSideEffects[BB] = true; | |||
| 358 | return true; | |||
| 359 | } | |||
| 360 | ||||
| 361 | BBSideEffects[BB] = false; | |||
| 362 | return false; | |||
| 363 | } | |||
| 364 | ||||
| 365 | // Return true when a successor of BB dominates A. | |||
| 366 | bool successorDominate(const BasicBlock *BB, const BasicBlock *A) { | |||
| 367 | for (const BasicBlock *Succ : successors(BB)) | |||
| 368 | if (DT->dominates(Succ, A)) | |||
| 369 | return true; | |||
| 370 | ||||
| 371 | return false; | |||
| 372 | } | |||
| 373 | ||||
| 374 | // Return true when I1 appears before I2 in the instructions of BB. | |||
| 375 | bool firstInBB(const Instruction *I1, const Instruction *I2) { | |||
| 376 | assert(I1->getParent() == I2->getParent())((I1->getParent() == I2->getParent()) ? static_cast< void> (0) : __assert_fail ("I1->getParent() == I2->getParent()" , "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/Scalar/GVNHoist.cpp" , 376, __PRETTY_FUNCTION__)); | |||
| 377 | unsigned I1DFS = DFSNumber.lookup(I1); | |||
| 378 | unsigned I2DFS = DFSNumber.lookup(I2); | |||
| 379 | assert(I1DFS && I2DFS)((I1DFS && I2DFS) ? static_cast<void> (0) : __assert_fail ("I1DFS && I2DFS", "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/Scalar/GVNHoist.cpp" , 379, __PRETTY_FUNCTION__)); | |||
| 380 | return I1DFS < I2DFS; | |||
| 381 | } | |||
| 382 | ||||
| 383 | // Return true when there are memory uses of Def in BB. | |||
| 384 | bool hasMemoryUse(const Instruction *NewPt, MemoryDef *Def, | |||
| 385 | const BasicBlock *BB) { | |||
| 386 | const MemorySSA::AccessList *Acc = MSSA->getBlockAccesses(BB); | |||
| 387 | if (!Acc) | |||
| 388 | return false; | |||
| 389 | ||||
| 390 | Instruction *OldPt = Def->getMemoryInst(); | |||
| 391 | const BasicBlock *OldBB = OldPt->getParent(); | |||
| 392 | const BasicBlock *NewBB = NewPt->getParent(); | |||
| 393 | bool ReachedNewPt = false; | |||
| 394 | ||||
| 395 | for (const MemoryAccess &MA : *Acc) | |||
| 396 | if (const MemoryUse *MU = dyn_cast<MemoryUse>(&MA)) { | |||
| 397 | Instruction *Insn = MU->getMemoryInst(); | |||
| 398 | ||||
| 399 | // Do not check whether MU aliases Def when MU occurs after OldPt. | |||
| 400 | if (BB == OldBB && firstInBB(OldPt, Insn)) | |||
| 401 | break; | |||
| 402 | ||||
| 403 | // Do not check whether MU aliases Def when MU occurs before NewPt. | |||
| 404 | if (BB == NewBB) { | |||
| 405 | if (!ReachedNewPt) { | |||
| 406 | if (firstInBB(Insn, NewPt)) | |||
| 407 | continue; | |||
| 408 | ReachedNewPt = true; | |||
| 409 | } | |||
| 410 | } | |||
| 411 | if (MemorySSAUtil::defClobbersUseOrDef(Def, MU, *AA)) | |||
| 412 | return true; | |||
| 413 | } | |||
| 414 | ||||
| 415 | return false; | |||
| 416 | } | |||
| 417 | ||||
| 418 | bool hasEHhelper(const BasicBlock *BB, const BasicBlock *SrcBB, | |||
| 419 | int &NBBsOnAllPaths) { | |||
| 420 | // Stop walk once the limit is reached. | |||
| 421 | if (NBBsOnAllPaths == 0) | |||
| 422 | return true; | |||
| 423 | ||||
| 424 | // Impossible to hoist with exceptions on the path. | |||
| 425 | if (hasEH(BB)) | |||
| 426 | return true; | |||
| 427 | ||||
| 428 | // No such instruction after HoistBarrier in a basic block was | |||
| 429 | // selected for hoisting so instructions selected within basic block with | |||
| 430 | // a hoist barrier can be hoisted. | |||
| 431 | if ((BB != SrcBB) && HoistBarrier.count(BB)) | |||
| 432 | return true; | |||
| 433 | ||||
| 434 | return false; | |||
| 435 | } | |||
| 436 | ||||
| 437 | // Return true when there are exception handling or loads of memory Def | |||
| 438 | // between Def and NewPt. This function is only called for stores: Def is | |||
| 439 | // the MemoryDef of the store to be hoisted. | |||
| 440 | ||||
| 441 | // Decrement by 1 NBBsOnAllPaths for each block between HoistPt and BB, and | |||
| 442 | // return true when the counter NBBsOnAllPaths reaces 0, except when it is | |||
| 443 | // initialized to -1 which is unlimited. | |||
| 444 | bool hasEHOrLoadsOnPath(const Instruction *NewPt, MemoryDef *Def, | |||
| 445 | int &NBBsOnAllPaths) { | |||
| 446 | const BasicBlock *NewBB = NewPt->getParent(); | |||
| 447 | const BasicBlock *OldBB = Def->getBlock(); | |||
| ||||
| 448 | assert(DT->dominates(NewBB, OldBB) && "invalid path")((DT->dominates(NewBB, OldBB) && "invalid path") ? static_cast<void> (0) : __assert_fail ("DT->dominates(NewBB, OldBB) && \"invalid path\"" , "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/Scalar/GVNHoist.cpp" , 448, __PRETTY_FUNCTION__)); | |||
| 449 | assert(DT->dominates(Def->getDefiningAccess()->getBlock(), NewBB) &&((DT->dominates(Def->getDefiningAccess()->getBlock() , NewBB) && "def does not dominate new hoisting point" ) ? static_cast<void> (0) : __assert_fail ("DT->dominates(Def->getDefiningAccess()->getBlock(), NewBB) && \"def does not dominate new hoisting point\"" , "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/Scalar/GVNHoist.cpp" , 450, __PRETTY_FUNCTION__)) | |||
| 450 | "def does not dominate new hoisting point")((DT->dominates(Def->getDefiningAccess()->getBlock() , NewBB) && "def does not dominate new hoisting point" ) ? static_cast<void> (0) : __assert_fail ("DT->dominates(Def->getDefiningAccess()->getBlock(), NewBB) && \"def does not dominate new hoisting point\"" , "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/Scalar/GVNHoist.cpp" , 450, __PRETTY_FUNCTION__)); | |||
| 451 | ||||
| 452 | // Walk all basic blocks reachable in depth-first iteration on the inverse | |||
| 453 | // CFG from OldBB to NewBB. These blocks are all the blocks that may be | |||
| 454 | // executed between the execution of NewBB and OldBB. Hoisting an expression | |||
| 455 | // from OldBB into NewBB has to be safe on all execution paths. | |||
| 456 | for (auto I = idf_begin(OldBB), E = idf_end(OldBB); I != E;) { | |||
| 457 | const BasicBlock *BB = *I; | |||
| 458 | if (BB == NewBB) { | |||
| 459 | // Stop traversal when reaching HoistPt. | |||
| 460 | I.skipChildren(); | |||
| 461 | continue; | |||
| 462 | } | |||
| 463 | ||||
| 464 | if (hasEHhelper(BB, OldBB, NBBsOnAllPaths)) | |||
| 465 | return true; | |||
| 466 | ||||
| 467 | // Check that we do not move a store past loads. | |||
| 468 | if (hasMemoryUse(NewPt, Def, BB)) | |||
| 469 | return true; | |||
| 470 | ||||
| 471 | // -1 is unlimited number of blocks on all paths. | |||
| 472 | if (NBBsOnAllPaths != -1) | |||
| 473 | --NBBsOnAllPaths; | |||
| 474 | ||||
| 475 | ++I; | |||
| 476 | } | |||
| 477 | ||||
| 478 | return false; | |||
| 479 | } | |||
| 480 | ||||
| 481 | // Return true when there are exception handling between HoistPt and BB. | |||
| 482 | // Decrement by 1 NBBsOnAllPaths for each block between HoistPt and BB, and | |||
| 483 | // return true when the counter NBBsOnAllPaths reaches 0, except when it is | |||
| 484 | // initialized to -1 which is unlimited. | |||
| 485 | bool hasEHOnPath(const BasicBlock *HoistPt, const BasicBlock *SrcBB, | |||
| 486 | int &NBBsOnAllPaths) { | |||
| 487 | assert(DT->dominates(HoistPt, SrcBB) && "Invalid path")((DT->dominates(HoistPt, SrcBB) && "Invalid path") ? static_cast<void> (0) : __assert_fail ("DT->dominates(HoistPt, SrcBB) && \"Invalid path\"" , "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/Scalar/GVNHoist.cpp" , 487, __PRETTY_FUNCTION__)); | |||
| 488 | ||||
| 489 | // Walk all basic blocks reachable in depth-first iteration on | |||
| 490 | // the inverse CFG from BBInsn to NewHoistPt. These blocks are all the | |||
| 491 | // blocks that may be executed between the execution of NewHoistPt and | |||
| 492 | // BBInsn. Hoisting an expression from BBInsn into NewHoistPt has to be safe | |||
| 493 | // on all execution paths. | |||
| 494 | for (auto I = idf_begin(SrcBB), E = idf_end(SrcBB); I != E;) { | |||
| 495 | const BasicBlock *BB = *I; | |||
| 496 | if (BB == HoistPt) { | |||
| 497 | // Stop traversal when reaching NewHoistPt. | |||
| 498 | I.skipChildren(); | |||
| 499 | continue; | |||
| 500 | } | |||
| 501 | ||||
| 502 | if (hasEHhelper(BB, SrcBB, NBBsOnAllPaths)) | |||
| 503 | return true; | |||
| 504 | ||||
| 505 | // -1 is unlimited number of blocks on all paths. | |||
| 506 | if (NBBsOnAllPaths != -1) | |||
| 507 | --NBBsOnAllPaths; | |||
| 508 | ||||
| 509 | ++I; | |||
| 510 | } | |||
| 511 | ||||
| 512 | return false; | |||
| 513 | } | |||
| 514 | ||||
| 515 | // Return true when it is safe to hoist a memory load or store U from OldPt | |||
| 516 | // to NewPt. | |||
| 517 | bool safeToHoistLdSt(const Instruction *NewPt, const Instruction *OldPt, | |||
| 518 | MemoryUseOrDef *U, InsKind K, int &NBBsOnAllPaths) { | |||
| 519 | // In place hoisting is safe. | |||
| 520 | if (NewPt == OldPt) | |||
| 521 | return true; | |||
| 522 | ||||
| 523 | const BasicBlock *NewBB = NewPt->getParent(); | |||
| 524 | const BasicBlock *OldBB = OldPt->getParent(); | |||
| 525 | const BasicBlock *UBB = U->getBlock(); | |||
| 526 | ||||
| 527 | // Check for dependences on the Memory SSA. | |||
| 528 | MemoryAccess *D = U->getDefiningAccess(); | |||
| 529 | BasicBlock *DBB = D->getBlock(); | |||
| 530 | if (DT->properlyDominates(NewBB, DBB)) | |||
| 531 | // Cannot move the load or store to NewBB above its definition in DBB. | |||
| 532 | return false; | |||
| 533 | ||||
| 534 | if (NewBB == DBB && !MSSA->isLiveOnEntryDef(D)) | |||
| 535 | if (auto *UD = dyn_cast<MemoryUseOrDef>(D)) | |||
| 536 | if (!firstInBB(UD->getMemoryInst(), NewPt)) | |||
| 537 | // Cannot move the load or store to NewPt above its definition in D. | |||
| 538 | return false; | |||
| 539 | ||||
| 540 | // Check for unsafe hoistings due to side effects. | |||
| 541 | if (K == InsKind::Store) { | |||
| 542 | if (hasEHOrLoadsOnPath(NewPt, dyn_cast<MemoryDef>(U), NBBsOnAllPaths)) | |||
| 543 | return false; | |||
| 544 | } else if (hasEHOnPath(NewBB, OldBB, NBBsOnAllPaths)) | |||
| 545 | return false; | |||
| 546 | ||||
| 547 | if (UBB == NewBB) { | |||
| 548 | if (DT->properlyDominates(DBB, NewBB)) | |||
| 549 | return true; | |||
| 550 | assert(UBB == DBB)((UBB == DBB) ? static_cast<void> (0) : __assert_fail ( "UBB == DBB", "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/Scalar/GVNHoist.cpp" , 550, __PRETTY_FUNCTION__)); | |||
| 551 | assert(MSSA->locallyDominates(D, U))((MSSA->locallyDominates(D, U)) ? static_cast<void> ( 0) : __assert_fail ("MSSA->locallyDominates(D, U)", "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/Scalar/GVNHoist.cpp" , 551, __PRETTY_FUNCTION__)); | |||
| 552 | } | |||
| 553 | ||||
| 554 | // No side effects: it is safe to hoist. | |||
| 555 | return true; | |||
| 556 | } | |||
| 557 | ||||
| 558 | // Return true when it is safe to hoist scalar instructions from all blocks in | |||
| 559 | // WL to HoistBB. | |||
| 560 | bool safeToHoistScalar(const BasicBlock *HoistBB, const BasicBlock *BB, | |||
| 561 | int &NBBsOnAllPaths) { | |||
| 562 | return !hasEHOnPath(HoistBB, BB, NBBsOnAllPaths); | |||
| 563 | } | |||
| 564 | ||||
| 565 | // In the inverse CFG, the dominance frontier of basic block (BB) is the | |||
| 566 | // point where ANTIC needs to be computed for instructions which are going | |||
| 567 | // to be hoisted. Since this point does not change during gvn-hoist, | |||
| 568 | // we compute it only once (on demand). | |||
| 569 | // The ides is inspired from: | |||
| 570 | // "Partial Redundancy Elimination in SSA Form" | |||
| 571 | // ROBERT KENNEDY, SUN CHAN, SHIN-MING LIU, RAYMOND LO, PENG TU and FRED CHOW | |||
| 572 | // They use similar idea in the forward graph to find fully redundant and | |||
| 573 | // partially redundant expressions, here it is used in the inverse graph to | |||
| 574 | // find fully anticipable instructions at merge point (post-dominator in | |||
| 575 | // the inverse CFG). | |||
| 576 | // Returns the edge via which an instruction in BB will get the values from. | |||
| 577 | ||||
| 578 | // Returns true when the values are flowing out to each edge. | |||
| 579 | bool valueAnticipable(CHIArgs C, Instruction *TI) const { | |||
| 580 | if (TI->getNumSuccessors() > (unsigned)size(C)) | |||
| 581 | return false; // Not enough args in this CHI. | |||
| 582 | ||||
| 583 | for (auto CHI : C) { | |||
| 584 | BasicBlock *Dest = CHI.Dest; | |||
| 585 | // Find if all the edges have values flowing out of BB. | |||
| 586 | bool Found = llvm::any_of( | |||
| 587 | successors(TI), [Dest](const BasicBlock *BB) { return BB == Dest; }); | |||
| 588 | if (!Found) | |||
| 589 | return false; | |||
| 590 | } | |||
| 591 | return true; | |||
| 592 | } | |||
| 593 | ||||
| 594 | // Check if it is safe to hoist values tracked by CHI in the range | |||
| 595 | // [Begin, End) and accumulate them in Safe. | |||
| 596 | void checkSafety(CHIArgs C, BasicBlock *BB, InsKind K, | |||
| 597 | SmallVectorImpl<CHIArg> &Safe) { | |||
| 598 | int NumBBsOnAllPaths = MaxNumberOfBBSInPath; | |||
| 599 | for (auto CHI : C) { | |||
| ||||
| 600 | Instruction *Insn = CHI.I; | |||
| 601 | if (!Insn) // No instruction was inserted in this CHI. | |||
| 602 | continue; | |||
| 603 | if (K == InsKind::Scalar) { | |||
| 604 | if (safeToHoistScalar(BB, Insn->getParent(), NumBBsOnAllPaths)) | |||
| 605 | Safe.push_back(CHI); | |||
| 606 | } else { | |||
| 607 | MemoryUseOrDef *UD = MSSA->getMemoryAccess(Insn); | |||
| 608 | if (safeToHoistLdSt(BB->getTerminator(), Insn, UD, K, NumBBsOnAllPaths)) | |||
| 609 | Safe.push_back(CHI); | |||
| 610 | } | |||
| 611 | } | |||
| 612 | } | |||
| 613 | ||||
| 614 | using RenameStackType = DenseMap<VNType, SmallVector<Instruction *, 2>>; | |||
| 615 | ||||
| 616 | // Push all the VNs corresponding to BB into RenameStack. | |||
| 617 | void fillRenameStack(BasicBlock *BB, InValuesType &ValueBBs, | |||
| 618 | RenameStackType &RenameStack) { | |||
| 619 | auto it1 = ValueBBs.find(BB); | |||
| 620 | if (it1 != ValueBBs.end()) { | |||
| 621 | // Iterate in reverse order to keep lower ranked values on the top. | |||
| 622 | for (std::pair<VNType, Instruction *> &VI : reverse(it1->second)) { | |||
| 623 | // Get the value of instruction I | |||
| 624 | LLVM_DEBUG(dbgs() << "\nPushing on stack: " << *VI.second)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("gvn-hoist")) { dbgs() << "\nPushing on stack: " << *VI.second; } } while (false); | |||
| 625 | RenameStack[VI.first].push_back(VI.second); | |||
| 626 | } | |||
| 627 | } | |||
| 628 | } | |||
| 629 | ||||
| 630 | void fillChiArgs(BasicBlock *BB, OutValuesType &CHIBBs, | |||
| 631 | RenameStackType &RenameStack) { | |||
| 632 | // For each *predecessor* (because Post-DOM) of BB check if it has a CHI | |||
| 633 | for (auto Pred : predecessors(BB)) { | |||
| 634 | auto P = CHIBBs.find(Pred); | |||
| 635 | if (P == CHIBBs.end()) { | |||
| 636 | continue; | |||
| 637 | } | |||
| 638 | LLVM_DEBUG(dbgs() << "\nLooking at CHIs in: " << Pred->getName();)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("gvn-hoist")) { dbgs() << "\nLooking at CHIs in: " << Pred->getName();; } } while (false); | |||
| 639 | // A CHI is found (BB -> Pred is an edge in the CFG) | |||
| 640 | // Pop the stack until Top(V) = Ve. | |||
| 641 | auto &VCHI = P->second; | |||
| 642 | for (auto It = VCHI.begin(), E = VCHI.end(); It != E;) { | |||
| 643 | CHIArg &C = *It; | |||
| 644 | if (!C.Dest) { | |||
| 645 | auto si = RenameStack.find(C.VN); | |||
| 646 | // The Basic Block where CHI is must dominate the value we want to | |||
| 647 | // track in a CHI. In the PDom walk, there can be values in the | |||
| 648 | // stack which are not control dependent e.g., nested loop. | |||
| 649 | if (si != RenameStack.end() && si->second.size() && | |||
| 650 | DT->properlyDominates(Pred, si->second.back()->getParent())) { | |||
| 651 | C.Dest = BB; // Assign the edge | |||
| 652 | C.I = si->second.pop_back_val(); // Assign the argument | |||
| 653 | LLVM_DEBUG(dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("gvn-hoist")) { dbgs() << "\nCHI Inserted in BB: " << C.Dest->getName() << *C.I << ", VN: " << C.VN.first << ", " << C.VN.second; } } while (false ) | |||
| 654 | << "\nCHI Inserted in BB: " << C.Dest->getName() << *C.Ido { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("gvn-hoist")) { dbgs() << "\nCHI Inserted in BB: " << C.Dest->getName() << *C.I << ", VN: " << C.VN.first << ", " << C.VN.second; } } while (false ) | |||
| 655 | << ", VN: " << C.VN.first << ", " << C.VN.second)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("gvn-hoist")) { dbgs() << "\nCHI Inserted in BB: " << C.Dest->getName() << *C.I << ", VN: " << C.VN.first << ", " << C.VN.second; } } while (false ); | |||
| 656 | } | |||
| 657 | // Move to next CHI of a different value | |||
| 658 | It = std::find_if(It, VCHI.end(), | |||
| 659 | [It](CHIArg &A) { return A != *It; }); | |||
| 660 | } else | |||
| 661 | ++It; | |||
| 662 | } | |||
| 663 | } | |||
| 664 | } | |||
| 665 | ||||
| 666 | // Walk the post-dominator tree top-down and use a stack for each value to | |||
| 667 | // store the last value you see. When you hit a CHI from a given edge, the | |||
| 668 | // value to use as the argument is at the top of the stack, add the value to | |||
| 669 | // CHI and pop. | |||
| 670 | void insertCHI(InValuesType &ValueBBs, OutValuesType &CHIBBs) { | |||
| 671 | auto Root = PDT->getNode(nullptr); | |||
| 672 | if (!Root) | |||
| 673 | return; | |||
| 674 | // Depth first walk on PDom tree to fill the CHIargs at each PDF. | |||
| 675 | RenameStackType RenameStack; | |||
| 676 | for (auto Node : depth_first(Root)) { | |||
| 677 | BasicBlock *BB = Node->getBlock(); | |||
| 678 | if (!BB) | |||
| 679 | continue; | |||
| 680 | ||||
| 681 | // Collect all values in BB and push to stack. | |||
| 682 | fillRenameStack(BB, ValueBBs, RenameStack); | |||
| 683 | ||||
| 684 | // Fill outgoing values in each CHI corresponding to BB. | |||
| 685 | fillChiArgs(BB, CHIBBs, RenameStack); | |||
| 686 | } | |||
| 687 | } | |||
| 688 | ||||
| 689 | // Walk all the CHI-nodes to find ones which have a empty-entry and remove | |||
| 690 | // them Then collect all the instructions which are safe to hoist and see if | |||
| 691 | // they form a list of anticipable values. OutValues contains CHIs | |||
| 692 | // corresponding to each basic block. | |||
| 693 | void findHoistableCandidates(OutValuesType &CHIBBs, InsKind K, | |||
| 694 | HoistingPointList &HPL) { | |||
| 695 | auto cmpVN = [](const CHIArg &A, const CHIArg &B) { return A.VN < B.VN; }; | |||
| 696 | ||||
| 697 | // CHIArgs now have the outgoing values, so check for anticipability and | |||
| 698 | // accumulate hoistable candidates in HPL. | |||
| 699 | for (std::pair<BasicBlock *, SmallVector<CHIArg, 2>> &A : CHIBBs) { | |||
| 700 | BasicBlock *BB = A.first; | |||
| 701 | SmallVectorImpl<CHIArg> &CHIs = A.second; | |||
| 702 | // Vector of PHIs contains PHIs for different instructions. | |||
| 703 | // Sort the args according to their VNs, such that identical | |||
| 704 | // instructions are together. | |||
| 705 | llvm::stable_sort(CHIs, cmpVN); | |||
| 706 | auto TI = BB->getTerminator(); | |||
| 707 | auto B = CHIs.begin(); | |||
| 708 | // [PreIt, PHIIt) form a range of CHIs which have identical VNs. | |||
| 709 | auto PHIIt = std::find_if(CHIs.begin(), CHIs.end(), | |||
| 710 | [B](CHIArg &A) { return A != *B; }); | |||
| 711 | auto PrevIt = CHIs.begin(); | |||
| 712 | while (PrevIt != PHIIt) { | |||
| 713 | // Collect values which satisfy safety checks. | |||
| 714 | SmallVector<CHIArg, 2> Safe; | |||
| 715 | // We check for safety first because there might be multiple values in | |||
| 716 | // the same path, some of which are not safe to be hoisted, but overall | |||
| 717 | // each edge has at least one value which can be hoisted, making the | |||
| 718 | // value anticipable along that path. | |||
| 719 | checkSafety(make_range(PrevIt, PHIIt), BB, K, Safe); | |||
| 720 | ||||
| 721 | // List of safe values should be anticipable at TI. | |||
| 722 | if (valueAnticipable(make_range(Safe.begin(), Safe.end()), TI)) { | |||
| 723 | HPL.push_back({BB, SmallVecInsn()}); | |||
| 724 | SmallVecInsn &V = HPL.back().second; | |||
| 725 | for (auto B : Safe) | |||
| 726 | V.push_back(B.I); | |||
| 727 | } | |||
| 728 | ||||
| 729 | // Check other VNs | |||
| 730 | PrevIt = PHIIt; | |||
| 731 | PHIIt = std::find_if(PrevIt, CHIs.end(), | |||
| 732 | [PrevIt](CHIArg &A) { return A != *PrevIt; }); | |||
| 733 | } | |||
| 734 | } | |||
| 735 | } | |||
| 736 | ||||
| 737 | // Compute insertion points for each values which can be fully anticipated at | |||
| 738 | // a dominator. HPL contains all such values. | |||
| 739 | void computeInsertionPoints(const VNtoInsns &Map, HoistingPointList &HPL, | |||
| 740 | InsKind K) { | |||
| 741 | // Sort VNs based on their rankings | |||
| 742 | std::vector<VNType> Ranks; | |||
| 743 | for (const auto &Entry : Map) { | |||
| 744 | Ranks.push_back(Entry.first); | |||
| 745 | } | |||
| 746 | ||||
| 747 | // TODO: Remove fully-redundant expressions. | |||
| 748 | // Get instruction from the Map, assume that all the Instructions | |||
| 749 | // with same VNs have same rank (this is an approximation). | |||
| 750 | llvm::sort(Ranks, [this, &Map](const VNType &r1, const VNType &r2) { | |||
| 751 | return (rank(*Map.lookup(r1).begin()) < rank(*Map.lookup(r2).begin())); | |||
| 752 | }); | |||
| 753 | ||||
| 754 | // - Sort VNs according to their rank, and start with lowest ranked VN | |||
| 755 | // - Take a VN and for each instruction with same VN | |||
| 756 | // - Find the dominance frontier in the inverse graph (PDF) | |||
| 757 | // - Insert the chi-node at PDF | |||
| 758 | // - Remove the chi-nodes with missing entries | |||
| 759 | // - Remove values from CHI-nodes which do not truly flow out, e.g., | |||
| 760 | // modified along the path. | |||
| 761 | // - Collect the remaining values that are still anticipable | |||
| 762 | SmallVector<BasicBlock *, 2> IDFBlocks; | |||
| 763 | ReverseIDFCalculator IDFs(*PDT); | |||
| 764 | OutValuesType OutValue; | |||
| 765 | InValuesType InValue; | |||
| 766 | for (const auto &R : Ranks) { | |||
| 767 | const SmallVecInsn &V = Map.lookup(R); | |||
| 768 | if (V.size() < 2) | |||
| 769 | continue; | |||
| 770 | const VNType &VN = R; | |||
| 771 | SmallPtrSet<BasicBlock *, 2> VNBlocks; | |||
| 772 | for (auto &I : V) { | |||
| 773 | BasicBlock *BBI = I->getParent(); | |||
| 774 | if (!hasEH(BBI)) | |||
| 775 | VNBlocks.insert(BBI); | |||
| 776 | } | |||
| 777 | // Compute the Post Dominance Frontiers of each basic block | |||
| 778 | // The dominance frontier of a live block X in the reverse | |||
| 779 | // control graph is the set of blocks upon which X is control | |||
| 780 | // dependent. The following sequence computes the set of blocks | |||
| 781 | // which currently have dead terminators that are control | |||
| 782 | // dependence sources of a block which is in NewLiveBlocks. | |||
| 783 | IDFs.setDefiningBlocks(VNBlocks); | |||
| 784 | IDFBlocks.clear(); | |||
| 785 | IDFs.calculate(IDFBlocks); | |||
| 786 | ||||
| 787 | // Make a map of BB vs instructions to be hoisted. | |||
| 788 | for (unsigned i = 0; i < V.size(); ++i) { | |||
| 789 | InValue[V[i]->getParent()].push_back(std::make_pair(VN, V[i])); | |||
| 790 | } | |||
| 791 | // Insert empty CHI node for this VN. This is used to factor out | |||
| 792 | // basic blocks where the ANTIC can potentially change. | |||
| 793 | for (auto IDFB : IDFBlocks) { | |||
| 794 | for (unsigned i = 0; i < V.size(); ++i) { | |||
| 795 | CHIArg C = {VN, nullptr, nullptr}; | |||
| 796 | // Ignore spurious PDFs. | |||
| 797 | if (DT->properlyDominates(IDFB, V[i]->getParent())) { | |||
| 798 | OutValue[IDFB].push_back(C); | |||
| 799 | LLVM_DEBUG(dbgs() << "\nInsertion a CHI for BB: " << IDFB->getName()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("gvn-hoist")) { dbgs() << "\nInsertion a CHI for BB: " << IDFB->getName() << ", for Insn: " << *V[i]; } } while (false) | |||
| 800 | << ", for Insn: " << *V[i])do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("gvn-hoist")) { dbgs() << "\nInsertion a CHI for BB: " << IDFB->getName() << ", for Insn: " << *V[i]; } } while (false); | |||
| 801 | } | |||
| 802 | } | |||
| 803 | } | |||
| 804 | } | |||
| 805 | ||||
| 806 | // Insert CHI args at each PDF to iterate on factored graph of | |||
| 807 | // control dependence. | |||
| 808 | insertCHI(InValue, OutValue); | |||
| 809 | // Using the CHI args inserted at each PDF, find fully anticipable values. | |||
| 810 | findHoistableCandidates(OutValue, K, HPL); | |||
| 811 | } | |||
| 812 | ||||
| 813 | // Return true when all operands of Instr are available at insertion point | |||
| 814 | // HoistPt. When limiting the number of hoisted expressions, one could hoist | |||
| 815 | // a load without hoisting its access function. So before hoisting any | |||
| 816 | // expression, make sure that all its operands are available at insert point. | |||
| 817 | bool allOperandsAvailable(const Instruction *I, | |||
| 818 | const BasicBlock *HoistPt) const { | |||
| 819 | for (const Use &Op : I->operands()) | |||
| 820 | if (const auto *Inst = dyn_cast<Instruction>(&Op)) | |||
| 821 | if (!DT->dominates(Inst->getParent(), HoistPt)) | |||
| 822 | return false; | |||
| 823 | ||||
| 824 | return true; | |||
| 825 | } | |||
| 826 | ||||
| 827 | // Same as allOperandsAvailable with recursive check for GEP operands. | |||
| 828 | bool allGepOperandsAvailable(const Instruction *I, | |||
| 829 | const BasicBlock *HoistPt) const { | |||
| 830 | for (const Use &Op : I->operands()) | |||
| 831 | if (const auto *Inst = dyn_cast<Instruction>(&Op)) | |||
| 832 | if (!DT->dominates(Inst->getParent(), HoistPt)) { | |||
| 833 | if (const GetElementPtrInst *GepOp = | |||
| 834 | dyn_cast<GetElementPtrInst>(Inst)) { | |||
| 835 | if (!allGepOperandsAvailable(GepOp, HoistPt)) | |||
| 836 | return false; | |||
| 837 | // Gep is available if all operands of GepOp are available. | |||
| 838 | } else { | |||
| 839 | // Gep is not available if it has operands other than GEPs that are | |||
| 840 | // defined in blocks not dominating HoistPt. | |||
| 841 | return false; | |||
| 842 | } | |||
| 843 | } | |||
| 844 | return true; | |||
| 845 | } | |||
| 846 | ||||
| 847 | // Make all operands of the GEP available. | |||
| 848 | void makeGepsAvailable(Instruction *Repl, BasicBlock *HoistPt, | |||
| 849 | const SmallVecInsn &InstructionsToHoist, | |||
| 850 | Instruction *Gep) const { | |||
| 851 | assert(allGepOperandsAvailable(Gep, HoistPt) &&((allGepOperandsAvailable(Gep, HoistPt) && "GEP operands not available" ) ? static_cast<void> (0) : __assert_fail ("allGepOperandsAvailable(Gep, HoistPt) && \"GEP operands not available\"" , "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/Scalar/GVNHoist.cpp" , 852, __PRETTY_FUNCTION__)) | |||
| 852 | "GEP operands not available")((allGepOperandsAvailable(Gep, HoistPt) && "GEP operands not available" ) ? static_cast<void> (0) : __assert_fail ("allGepOperandsAvailable(Gep, HoistPt) && \"GEP operands not available\"" , "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/Scalar/GVNHoist.cpp" , 852, __PRETTY_FUNCTION__)); | |||
| 853 | ||||
| 854 | Instruction *ClonedGep = Gep->clone(); | |||
| 855 | for (unsigned i = 0, e = Gep->getNumOperands(); i != e; ++i) | |||
| 856 | if (Instruction *Op = dyn_cast<Instruction>(Gep->getOperand(i))) { | |||
| 857 | // Check whether the operand is already available. | |||
| 858 | if (DT->dominates(Op->getParent(), HoistPt)) | |||
| 859 | continue; | |||
| 860 | ||||
| 861 | // As a GEP can refer to other GEPs, recursively make all the operands | |||
| 862 | // of this GEP available at HoistPt. | |||
| 863 | if (GetElementPtrInst *GepOp = dyn_cast<GetElementPtrInst>(Op)) | |||
| 864 | makeGepsAvailable(ClonedGep, HoistPt, InstructionsToHoist, GepOp); | |||
| 865 | } | |||
| 866 | ||||
| 867 | // Copy Gep and replace its uses in Repl with ClonedGep. | |||
| 868 | ClonedGep->insertBefore(HoistPt->getTerminator()); | |||
| 869 | ||||
| 870 | // Conservatively discard any optimization hints, they may differ on the | |||
| 871 | // other paths. | |||
| 872 | ClonedGep->dropUnknownNonDebugMetadata(); | |||
| 873 | ||||
| 874 | // If we have optimization hints which agree with each other along different | |||
| 875 | // paths, preserve them. | |||
| 876 | for (const Instruction *OtherInst : InstructionsToHoist) { | |||
| 877 | const GetElementPtrInst *OtherGep; | |||
| 878 | if (auto *OtherLd = dyn_cast<LoadInst>(OtherInst)) | |||
| 879 | OtherGep = cast<GetElementPtrInst>(OtherLd->getPointerOperand()); | |||
| 880 | else | |||
| 881 | OtherGep = cast<GetElementPtrInst>( | |||
| 882 | cast<StoreInst>(OtherInst)->getPointerOperand()); | |||
| 883 | ClonedGep->andIRFlags(OtherGep); | |||
| 884 | } | |||
| 885 | ||||
| 886 | // Replace uses of Gep with ClonedGep in Repl. | |||
| 887 | Repl->replaceUsesOfWith(Gep, ClonedGep); | |||
| 888 | } | |||
| 889 | ||||
| 890 | void updateAlignment(Instruction *I, Instruction *Repl) { | |||
| 891 | if (auto *ReplacementLoad = dyn_cast<LoadInst>(Repl)) { | |||
| 892 | ReplacementLoad->setAlignment(MaybeAlign(std::min( | |||
| 893 | ReplacementLoad->getAlignment(), cast<LoadInst>(I)->getAlignment()))); | |||
| 894 | ++NumLoadsRemoved; | |||
| 895 | } else if (auto *ReplacementStore = dyn_cast<StoreInst>(Repl)) { | |||
| 896 | ReplacementStore->setAlignment( | |||
| 897 | MaybeAlign(std::min(ReplacementStore->getAlignment(), | |||
| 898 | cast<StoreInst>(I)->getAlignment()))); | |||
| 899 | ++NumStoresRemoved; | |||
| 900 | } else if (auto *ReplacementAlloca = dyn_cast<AllocaInst>(Repl)) { | |||
| 901 | ReplacementAlloca->setAlignment( | |||
| 902 | MaybeAlign(std::max(ReplacementAlloca->getAlignment(), | |||
| 903 | cast<AllocaInst>(I)->getAlignment()))); | |||
| 904 | } else if (isa<CallInst>(Repl)) { | |||
| 905 | ++NumCallsRemoved; | |||
| 906 | } | |||
| 907 | } | |||
| 908 | ||||
| 909 | // Remove all the instructions in Candidates and replace their usage with Repl. | |||
| 910 | // Returns the number of instructions removed. | |||
| 911 | unsigned rauw(const SmallVecInsn &Candidates, Instruction *Repl, | |||
| 912 | MemoryUseOrDef *NewMemAcc) { | |||
| 913 | unsigned NR = 0; | |||
| 914 | for (Instruction *I : Candidates) { | |||
| 915 | if (I != Repl) { | |||
| 916 | ++NR; | |||
| 917 | updateAlignment(I, Repl); | |||
| 918 | if (NewMemAcc) { | |||
| 919 | // Update the uses of the old MSSA access with NewMemAcc. | |||
| 920 | MemoryAccess *OldMA = MSSA->getMemoryAccess(I); | |||
| 921 | OldMA->replaceAllUsesWith(NewMemAcc); | |||
| 922 | MSSAUpdater->removeMemoryAccess(OldMA); | |||
| 923 | } | |||
| 924 | ||||
| 925 | Repl->andIRFlags(I); | |||
| 926 | combineKnownMetadata(Repl, I); | |||
| 927 | I->replaceAllUsesWith(Repl); | |||
| 928 | // Also invalidate the Alias Analysis cache. | |||
| 929 | MD->removeInstruction(I); | |||
| 930 | I->eraseFromParent(); | |||
| 931 | } | |||
| 932 | } | |||
| 933 | return NR; | |||
| 934 | } | |||
| 935 | ||||
| 936 | // Replace all Memory PHI usage with NewMemAcc. | |||
| 937 | void raMPHIuw(MemoryUseOrDef *NewMemAcc) { | |||
| 938 | SmallPtrSet<MemoryPhi *, 4> UsePhis; | |||
| 939 | for (User *U : NewMemAcc->users()) | |||
| 940 | if (MemoryPhi *Phi = dyn_cast<MemoryPhi>(U)) | |||
| 941 | UsePhis.insert(Phi); | |||
| 942 | ||||
| 943 | for (MemoryPhi *Phi : UsePhis) { | |||
| 944 | auto In = Phi->incoming_values(); | |||
| 945 | if (llvm::all_of(In, [&](Use &U) { return U == NewMemAcc; })) { | |||
| 946 | Phi->replaceAllUsesWith(NewMemAcc); | |||
| 947 | MSSAUpdater->removeMemoryAccess(Phi); | |||
| 948 | } | |||
| 949 | } | |||
| 950 | } | |||
| 951 | ||||
| 952 | // Remove all other instructions and replace them with Repl. | |||
| 953 | unsigned removeAndReplace(const SmallVecInsn &Candidates, Instruction *Repl, | |||
| 954 | BasicBlock *DestBB, bool MoveAccess) { | |||
| 955 | MemoryUseOrDef *NewMemAcc = MSSA->getMemoryAccess(Repl); | |||
| 956 | if (MoveAccess && NewMemAcc) { | |||
| 957 | // The definition of this ld/st will not change: ld/st hoisting is | |||
| 958 | // legal when the ld/st is not moved past its current definition. | |||
| 959 | MSSAUpdater->moveToPlace(NewMemAcc, DestBB, MemorySSA::End); | |||
| 960 | } | |||
| 961 | ||||
| 962 | // Replace all other instructions with Repl with memory access NewMemAcc. | |||
| 963 | unsigned NR = rauw(Candidates, Repl, NewMemAcc); | |||
| 964 | ||||
| 965 | // Remove MemorySSA phi nodes with the same arguments. | |||
| 966 | if (NewMemAcc) | |||
| 967 | raMPHIuw(NewMemAcc); | |||
| 968 | return NR; | |||
| 969 | } | |||
| 970 | ||||
| 971 | // In the case Repl is a load or a store, we make all their GEPs | |||
| 972 | // available: GEPs are not hoisted by default to avoid the address | |||
| 973 | // computations to be hoisted without the associated load or store. | |||
| 974 | bool makeGepOperandsAvailable(Instruction *Repl, BasicBlock *HoistPt, | |||
| 975 | const SmallVecInsn &InstructionsToHoist) const { | |||
| 976 | // Check whether the GEP of a ld/st can be synthesized at HoistPt. | |||
| 977 | GetElementPtrInst *Gep = nullptr; | |||
| 978 | Instruction *Val = nullptr; | |||
| 979 | if (auto *Ld = dyn_cast<LoadInst>(Repl)) { | |||
| 980 | Gep = dyn_cast<GetElementPtrInst>(Ld->getPointerOperand()); | |||
| 981 | } else if (auto *St = dyn_cast<StoreInst>(Repl)) { | |||
| 982 | Gep = dyn_cast<GetElementPtrInst>(St->getPointerOperand()); | |||
| 983 | Val = dyn_cast<Instruction>(St->getValueOperand()); | |||
| 984 | // Check that the stored value is available. | |||
| 985 | if (Val) { | |||
| 986 | if (isa<GetElementPtrInst>(Val)) { | |||
| 987 | // Check whether we can compute the GEP at HoistPt. | |||
| 988 | if (!allGepOperandsAvailable(Val, HoistPt)) | |||
| 989 | return false; | |||
| 990 | } else if (!DT->dominates(Val->getParent(), HoistPt)) | |||
| 991 | return false; | |||
| 992 | } | |||
| 993 | } | |||
| 994 | ||||
| 995 | // Check whether we can compute the Gep at HoistPt. | |||
| 996 | if (!Gep || !allGepOperandsAvailable(Gep, HoistPt)) | |||
| 997 | return false; | |||
| 998 | ||||
| 999 | makeGepsAvailable(Repl, HoistPt, InstructionsToHoist, Gep); | |||
| 1000 | ||||
| 1001 | if (Val && isa<GetElementPtrInst>(Val)) | |||
| 1002 | makeGepsAvailable(Repl, HoistPt, InstructionsToHoist, Val); | |||
| 1003 | ||||
| 1004 | return true; | |||
| 1005 | } | |||
| 1006 | ||||
| 1007 | std::pair<unsigned, unsigned> hoist(HoistingPointList &HPL) { | |||
| 1008 | unsigned NI = 0, NL = 0, NS = 0, NC = 0, NR = 0; | |||
| 1009 | for (const HoistingPointInfo &HP : HPL) { | |||
| 1010 | // Find out whether we already have one of the instructions in HoistPt, | |||
| 1011 | // in which case we do not have to move it. | |||
| 1012 | BasicBlock *DestBB = HP.first; | |||
| 1013 | const SmallVecInsn &InstructionsToHoist = HP.second; | |||
| 1014 | Instruction *Repl = nullptr; | |||
| 1015 | for (Instruction *I : InstructionsToHoist) | |||
| 1016 | if (I->getParent() == DestBB) | |||
| 1017 | // If there are two instructions in HoistPt to be hoisted in place: | |||
| 1018 | // update Repl to be the first one, such that we can rename the uses | |||
| 1019 | // of the second based on the first. | |||
| 1020 | if (!Repl || firstInBB(I, Repl)) | |||
| 1021 | Repl = I; | |||
| 1022 | ||||
| 1023 | // Keep track of whether we moved the instruction so we know whether we | |||
| 1024 | // should move the MemoryAccess. | |||
| 1025 | bool MoveAccess = true; | |||
| 1026 | if (Repl) { | |||
| 1027 | // Repl is already in HoistPt: it remains in place. | |||
| 1028 | assert(allOperandsAvailable(Repl, DestBB) &&((allOperandsAvailable(Repl, DestBB) && "instruction depends on operands that are not available" ) ? static_cast<void> (0) : __assert_fail ("allOperandsAvailable(Repl, DestBB) && \"instruction depends on operands that are not available\"" , "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/Scalar/GVNHoist.cpp" , 1029, __PRETTY_FUNCTION__)) | |||
| 1029 | "instruction depends on operands that are not available")((allOperandsAvailable(Repl, DestBB) && "instruction depends on operands that are not available" ) ? static_cast<void> (0) : __assert_fail ("allOperandsAvailable(Repl, DestBB) && \"instruction depends on operands that are not available\"" , "/build/llvm-toolchain-snapshot-10~svn374877/lib/Transforms/Scalar/GVNHoist.cpp" , 1029, __PRETTY_FUNCTION__)); | |||
| 1030 | MoveAccess = false; | |||
| 1031 | } else { | |||
| 1032 | // When we do not find Repl in HoistPt, select the first in the list | |||
| 1033 | // and move it to HoistPt. | |||
| 1034 | Repl = InstructionsToHoist.front(); | |||
| 1035 | ||||
| 1036 | // We can move Repl in HoistPt only when all operands are available. | |||
| 1037 | // The order in which hoistings are done may influence the availability | |||
| 1038 | // of operands. | |||
| 1039 | if (!allOperandsAvailable(Repl, DestBB)) { | |||
| 1040 | // When HoistingGeps there is nothing more we can do to make the | |||
| 1041 | // operands available: just continue. | |||
| 1042 | if (HoistingGeps) | |||
| 1043 | continue; | |||
| 1044 | ||||
| 1045 | // When not HoistingGeps we need to copy the GEPs. | |||
| 1046 | if (!makeGepOperandsAvailable(Repl, DestBB, InstructionsToHoist)) | |||
| 1047 | continue; | |||
| 1048 | } | |||
| 1049 | ||||
| 1050 | // Move the instruction at the end of HoistPt. | |||
| 1051 | Instruction *Last = DestBB->getTerminator(); | |||
| 1052 | MD->removeInstruction(Repl); | |||
| 1053 | Repl->moveBefore(Last); | |||
| 1054 | ||||
| 1055 | DFSNumber[Repl] = DFSNumber[Last]++; | |||
| 1056 | } | |||
| 1057 | ||||
| 1058 | NR += removeAndReplace(InstructionsToHoist, Repl, DestBB, MoveAccess); | |||
| 1059 | ||||
| 1060 | if (isa<LoadInst>(Repl)) | |||
| 1061 | ++NL; | |||
| 1062 | else if (isa<StoreInst>(Repl)) | |||
| 1063 | ++NS; | |||
| 1064 | else if (isa<CallInst>(Repl)) | |||
| 1065 | ++NC; | |||
| 1066 | else // Scalar | |||
| 1067 | ++NI; | |||
| 1068 | } | |||
| 1069 | ||||
| 1070 | NumHoisted += NL + NS + NC + NI; | |||
| 1071 | NumRemoved += NR; | |||
| 1072 | NumLoadsHoisted += NL; | |||
| 1073 | NumStoresHoisted += NS; | |||
| 1074 | NumCallsHoisted += NC; | |||
| 1075 | return {NI, NL + NC + NS}; | |||
| 1076 | } | |||
| 1077 | ||||
| 1078 | // Hoist all expressions. Returns Number of scalars hoisted | |||
| 1079 | // and number of non-scalars hoisted. | |||
| 1080 | std::pair<unsigned, unsigned> hoistExpressions(Function &F) { | |||
| 1081 | InsnInfo II; | |||
| 1082 | LoadInfo LI; | |||
| 1083 | StoreInfo SI; | |||
| 1084 | CallInfo CI; | |||
| 1085 | for (BasicBlock *BB : depth_first(&F.getEntryBlock())) { | |||
| 1086 | int InstructionNb = 0; | |||
| 1087 | for (Instruction &I1 : *BB) { | |||
| 1088 | // If I1 cannot guarantee progress, subsequent instructions | |||
| 1089 | // in BB cannot be hoisted anyways. | |||
| 1090 | if (!isGuaranteedToTransferExecutionToSuccessor(&I1)) { | |||
| 1091 | HoistBarrier.insert(BB); | |||
| 1092 | break; | |||
| 1093 | } | |||
| 1094 | // Only hoist the first instructions in BB up to MaxDepthInBB. Hoisting | |||
| 1095 | // deeper may increase the register pressure and compilation time. | |||
| 1096 | if (MaxDepthInBB != -1 && InstructionNb++ >= MaxDepthInBB) | |||
| 1097 | break; | |||
| 1098 | ||||
| 1099 | // Do not value number terminator instructions. | |||
| 1100 | if (I1.isTerminator()) | |||
| 1101 | break; | |||
| 1102 | ||||
| 1103 | if (auto *Load = dyn_cast<LoadInst>(&I1)) | |||
| 1104 | LI.insert(Load, VN); | |||
| 1105 | else if (auto *Store = dyn_cast<StoreInst>(&I1)) | |||
| 1106 | SI.insert(Store, VN); | |||
| 1107 | else if (auto *Call = dyn_cast<CallInst>(&I1)) { | |||
| 1108 | if (auto *Intr = dyn_cast<IntrinsicInst>(Call)) { | |||
| 1109 | if (isa<DbgInfoIntrinsic>(Intr) || | |||
| 1110 | Intr->getIntrinsicID() == Intrinsic::assume || | |||
| 1111 | Intr->getIntrinsicID() == Intrinsic::sideeffect) | |||
| 1112 | continue; | |||
| 1113 | } | |||
| 1114 | if (Call->mayHaveSideEffects()) | |||
| 1115 | break; | |||
| 1116 | ||||
| 1117 | if (Call->isConvergent()) | |||
| 1118 | break; | |||
| 1119 | ||||
| 1120 | CI.insert(Call, VN); | |||
| 1121 | } else if (HoistingGeps || !isa<GetElementPtrInst>(&I1)) | |||
| 1122 | // Do not hoist scalars past calls that may write to memory because | |||
| 1123 | // that could result in spills later. geps are handled separately. | |||
| 1124 | // TODO: We can relax this for targets like AArch64 as they have more | |||
| 1125 | // registers than X86. | |||
| 1126 | II.insert(&I1, VN); | |||
| 1127 | } | |||
| 1128 | } | |||
| 1129 | ||||
| 1130 | HoistingPointList HPL; | |||
| 1131 | computeInsertionPoints(II.getVNTable(), HPL, InsKind::Scalar); | |||
| 1132 | computeInsertionPoints(LI.getVNTable(), HPL, InsKind::Load); | |||
| 1133 | computeInsertionPoints(SI.getVNTable(), HPL, InsKind::Store); | |||
| 1134 | computeInsertionPoints(CI.getScalarVNTable(), HPL, InsKind::Scalar); | |||
| 1135 | computeInsertionPoints(CI.getLoadVNTable(), HPL, InsKind::Load); | |||
| 1136 | computeInsertionPoints(CI.getStoreVNTable(), HPL, InsKind::Store); | |||
| 1137 | return hoist(HPL); | |||
| 1138 | } | |||
| 1139 | }; | |||
| 1140 | ||||
| 1141 | class GVNHoistLegacyPass : public FunctionPass { | |||
| 1142 | public: | |||
| 1143 | static char ID; | |||
| 1144 | ||||
| 1145 | GVNHoistLegacyPass() : FunctionPass(ID) { | |||
| 1146 | initializeGVNHoistLegacyPassPass(*PassRegistry::getPassRegistry()); | |||
| 1147 | } | |||
| 1148 | ||||
| 1149 | bool runOnFunction(Function &F) override { | |||
| 1150 | if (skipFunction(F)) | |||
| 1151 | return false; | |||
| 1152 | auto &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree(); | |||
| 1153 | auto &PDT = getAnalysis<PostDominatorTreeWrapperPass>().getPostDomTree(); | |||
| 1154 | auto &AA = getAnalysis<AAResultsWrapperPass>().getAAResults(); | |||
| 1155 | auto &MD = getAnalysis<MemoryDependenceWrapperPass>().getMemDep(); | |||
| 1156 | auto &MSSA = getAnalysis<MemorySSAWrapperPass>().getMSSA(); | |||
| 1157 | ||||
| 1158 | GVNHoist G(&DT, &PDT, &AA, &MD, &MSSA); | |||
| 1159 | return G.run(F); | |||
| 1160 | } | |||
| 1161 | ||||
| 1162 | void getAnalysisUsage(AnalysisUsage &AU) const override { | |||
| 1163 | AU.addRequired<DominatorTreeWrapperPass>(); | |||
| 1164 | AU.addRequired<PostDominatorTreeWrapperPass>(); | |||
| 1165 | AU.addRequired<AAResultsWrapperPass>(); | |||
| 1166 | AU.addRequired<MemoryDependenceWrapperPass>(); | |||
| 1167 | AU.addRequired<MemorySSAWrapperPass>(); | |||
| 1168 | AU.addPreserved<DominatorTreeWrapperPass>(); | |||
| 1169 | AU.addPreserved<MemorySSAWrapperPass>(); | |||
| 1170 | AU.addPreserved<GlobalsAAWrapperPass>(); | |||
| 1171 | } | |||
| 1172 | }; | |||
| 1173 | ||||
| 1174 | } // end namespace llvm | |||
| 1175 | ||||
| 1176 | PreservedAnalyses GVNHoistPass::run(Function &F, FunctionAnalysisManager &AM) { | |||
| 1177 | DominatorTree &DT = AM.getResult<DominatorTreeAnalysis>(F); | |||
| 1178 | PostDominatorTree &PDT = AM.getResult<PostDominatorTreeAnalysis>(F); | |||
| 1179 | AliasAnalysis &AA = AM.getResult<AAManager>(F); | |||
| 1180 | MemoryDependenceResults &MD = AM.getResult<MemoryDependenceAnalysis>(F); | |||
| 1181 | MemorySSA &MSSA = AM.getResult<MemorySSAAnalysis>(F).getMSSA(); | |||
| 1182 | GVNHoist G(&DT, &PDT, &AA, &MD, &MSSA); | |||
| 1183 | if (!G.run(F)) | |||
| 1184 | return PreservedAnalyses::all(); | |||
| 1185 | ||||
| 1186 | PreservedAnalyses PA; | |||
| 1187 | PA.preserve<DominatorTreeAnalysis>(); | |||
| 1188 | PA.preserve<MemorySSAAnalysis>(); | |||
| 1189 | PA.preserve<GlobalsAA>(); | |||
| 1190 | return PA; | |||
| 1191 | } | |||
| 1192 | ||||
| 1193 | char GVNHoistLegacyPass::ID = 0; | |||
| 1194 | ||||
| 1195 | INITIALIZE_PASS_BEGIN(GVNHoistLegacyPass, "gvn-hoist",static void *initializeGVNHoistLegacyPassPassOnce(PassRegistry &Registry) { | |||
| 1196 | "Early GVN Hoisting of Expressions", false, false)static void *initializeGVNHoistLegacyPassPassOnce(PassRegistry &Registry) { | |||
| 1197 | INITIALIZE_PASS_DEPENDENCY(MemoryDependenceWrapperPass)initializeMemoryDependenceWrapperPassPass(Registry); | |||
| 1198 | INITIALIZE_PASS_DEPENDENCY(MemorySSAWrapperPass)initializeMemorySSAWrapperPassPass(Registry); | |||
| 1199 | INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)initializeDominatorTreeWrapperPassPass(Registry); | |||
| 1200 | INITIALIZE_PASS_DEPENDENCY(PostDominatorTreeWrapperPass)initializePostDominatorTreeWrapperPassPass(Registry); | |||
| 1201 | INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)initializeAAResultsWrapperPassPass(Registry); | |||
| 1202 | INITIALIZE_PASS_END(GVNHoistLegacyPass, "gvn-hoist",PassInfo *PI = new PassInfo( "Early GVN Hoisting of Expressions" , "gvn-hoist", &GVNHoistLegacyPass::ID, PassInfo::NormalCtor_t (callDefaultCtor<GVNHoistLegacyPass>), false, false); Registry .registerPass(*PI, true); return PI; } static llvm::once_flag InitializeGVNHoistLegacyPassPassFlag; void llvm::initializeGVNHoistLegacyPassPass (PassRegistry &Registry) { llvm::call_once(InitializeGVNHoistLegacyPassPassFlag , initializeGVNHoistLegacyPassPassOnce, std::ref(Registry)); } | |||
| 1203 | "Early GVN Hoisting of Expressions", false, false)PassInfo *PI = new PassInfo( "Early GVN Hoisting of Expressions" , "gvn-hoist", &GVNHoistLegacyPass::ID, PassInfo::NormalCtor_t (callDefaultCtor<GVNHoistLegacyPass>), false, false); Registry .registerPass(*PI, true); return PI; } static llvm::once_flag InitializeGVNHoistLegacyPassPassFlag; void llvm::initializeGVNHoistLegacyPassPass (PassRegistry &Registry) { llvm::call_once(InitializeGVNHoistLegacyPassPassFlag , initializeGVNHoistLegacyPassPassOnce, std::ref(Registry)); } | |||
| 1204 | ||||
| 1205 | FunctionPass *llvm::createGVNHoistPass() { return new GVNHoistLegacyPass(); } |