1e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner//===-- LoopIdiomRecognize.cpp - Loop idiom recognition -------------------===// 2e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner// 3e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner// The LLVM Compiler Infrastructure 4e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner// 5e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner// This file is distributed under the University of Illinois Open Source 6e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner// License. See LICENSE.TXT for details. 7e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner// 8e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner//===----------------------------------------------------------------------===// 9e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner// 10e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner// This pass implements an idiom recognizer that transforms simple loops into a 11e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner// non-loop form. In cases that this kicks in, it can be a significant 12e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner// performance win. 13e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner// 14e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner//===----------------------------------------------------------------------===// 15bdce5720ad878259544e6a4e3621dac32cf2d134Chris Lattner// 16bdce5720ad878259544e6a4e3621dac32cf2d134Chris Lattner// TODO List: 17bdce5720ad878259544e6a4e3621dac32cf2d134Chris Lattner// 18bdce5720ad878259544e6a4e3621dac32cf2d134Chris Lattner// Future loop memory idioms to recognize: 19bdce5720ad878259544e6a4e3621dac32cf2d134Chris Lattner// memcmp, memmove, strlen, etc. 20bdce5720ad878259544e6a4e3621dac32cf2d134Chris Lattner// Future floating point idioms to recognize in -ffast-math mode: 21bdce5720ad878259544e6a4e3621dac32cf2d134Chris Lattner// fpowi 22bdce5720ad878259544e6a4e3621dac32cf2d134Chris Lattner// Future integer operation idioms to recognize: 23bdce5720ad878259544e6a4e3621dac32cf2d134Chris Lattner// ctpop, ctlz, cttz 24bdce5720ad878259544e6a4e3621dac32cf2d134Chris Lattner// 25bdce5720ad878259544e6a4e3621dac32cf2d134Chris Lattner// Beware that isel's default lowering for ctpop is highly inefficient for 26bdce5720ad878259544e6a4e3621dac32cf2d134Chris Lattner// i64 and larger types when i64 is legal and the value has few bits set. It 27bdce5720ad878259544e6a4e3621dac32cf2d134Chris Lattner// would be good to enhance isel to emit a loop for ctpop in this case. 28bdce5720ad878259544e6a4e3621dac32cf2d134Chris Lattner// 29bdce5720ad878259544e6a4e3621dac32cf2d134Chris Lattner// We should enhance the memset/memcpy recognition to handle multiple stores in 30bdce5720ad878259544e6a4e3621dac32cf2d134Chris Lattner// the loop. This would handle things like: 31bdce5720ad878259544e6a4e3621dac32cf2d134Chris Lattner// void foo(_Complex float *P) 32bdce5720ad878259544e6a4e3621dac32cf2d134Chris Lattner// for (i) { __real__(*P) = 0; __imag__(*P) = 0; } 3391139ccd995149dd0d5e4ab3604d9239e1f90a54Chris Lattner// 34408b534e431cc317f1116cd78df96da2af7cafd9Chris Lattner// We should enhance this to handle negative strides through memory. 35408b534e431cc317f1116cd78df96da2af7cafd9Chris Lattner// Alternatively (and perhaps better) we could rely on an earlier pass to force 36408b534e431cc317f1116cd78df96da2af7cafd9Chris Lattner// forward iteration through memory, which is generally better for cache 37408b534e431cc317f1116cd78df96da2af7cafd9Chris Lattner// behavior. Negative strides *do* happen for memset/memcpy loops. 38408b534e431cc317f1116cd78df96da2af7cafd9Chris Lattner// 39d957c717918c412402157b85fc51b4c6d2631381Chris Lattner// This could recognize common matrix multiplies and dot product idioms and 4091139ccd995149dd0d5e4ab3604d9239e1f90a54Chris Lattner// replace them with calls to BLAS (if linked in??). 4191139ccd995149dd0d5e4ab3604d9239e1f90a54Chris Lattner// 42bdce5720ad878259544e6a4e3621dac32cf2d134Chris Lattner//===----------------------------------------------------------------------===// 43e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner 44e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner#define DEBUG_TYPE "loop-idiom" 45e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner#include "llvm/Transforms/Scalar.h" 46e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner#include "llvm/IntrinsicInst.h" 473a393728a62122d7009d8e2cbe52a221874e576aChris Lattner#include "llvm/Module.h" 482e12f1ac6ebd49e5c41b7e9dcd802f3df40a1bc7Chris Lattner#include "llvm/Analysis/AliasAnalysis.h" 49e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner#include "llvm/Analysis/LoopPass.h" 50e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner#include "llvm/Analysis/ScalarEvolutionExpressions.h" 51a92ff91a967c63a2395a34c9e8331a7d50d6ab10Chris Lattner#include "llvm/Analysis/ScalarEvolutionExpander.h" 5222920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner#include "llvm/Analysis/ValueTracking.h" 5322920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner#include "llvm/Target/TargetData.h" 54c19175c9d8d3c2663b682a7fe34bb22da370d5c1Chris Lattner#include "llvm/Target/TargetLibraryInfo.h" 559f39188def2b4102817945522fac1209083efa06Chris Lattner#include "llvm/Transforms/Utils/Local.h" 56e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner#include "llvm/Support/Debug.h" 57a92ff91a967c63a2395a34c9e8331a7d50d6ab10Chris Lattner#include "llvm/Support/IRBuilder.h" 58e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner#include "llvm/Support/raw_ostream.h" 594ce31fb57412b16cd61337ba41c60112dfbecfb6Chris Lattner#include "llvm/ADT/Statistic.h" 60e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattnerusing namespace llvm; 61e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner 624ce31fb57412b16cd61337ba41c60112dfbecfb6Chris LattnerSTATISTIC(NumMemSet, "Number of memset's formed from loop stores"); 634ce31fb57412b16cd61337ba41c60112dfbecfb6Chris LattnerSTATISTIC(NumMemCpy, "Number of memcpy's formed from loop load+stores"); 64e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner 65e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattnernamespace { 66e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner class LoopIdiomRecognize : public LoopPass { 6722920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner Loop *CurLoop; 6822920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner const TargetData *TD; 6962c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner DominatorTree *DT; 7022920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner ScalarEvolution *SE; 71c19175c9d8d3c2663b682a7fe34bb22da370d5c1Chris Lattner TargetLibraryInfo *TLI; 72e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner public: 73e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner static char ID; 74e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner explicit LoopIdiomRecognize() : LoopPass(ID) { 75e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner initializeLoopIdiomRecognizePass(*PassRegistry::getPassRegistry()); 76e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner } 77e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner 78e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner bool runOnLoop(Loop *L, LPPassManager &LPM); 7962c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner bool runOnLoopBlock(BasicBlock *BB, const SCEV *BECount, 8062c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner SmallVectorImpl<BasicBlock*> &ExitBlocks); 81e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner 8222920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner bool processLoopStore(StoreInst *SI, const SCEV *BECount); 83e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner bool processLoopMemSet(MemSetInst *MSI, const SCEV *BECount); 84d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 853a393728a62122d7009d8e2cbe52a221874e576aChris Lattner bool processLoopStridedStore(Value *DestPtr, unsigned StoreSize, 863a393728a62122d7009d8e2cbe52a221874e576aChris Lattner unsigned StoreAlignment, 873a393728a62122d7009d8e2cbe52a221874e576aChris Lattner Value *SplatValue, Instruction *TheStore, 883a393728a62122d7009d8e2cbe52a221874e576aChris Lattner const SCEVAddRecExpr *Ev, 893a393728a62122d7009d8e2cbe52a221874e576aChris Lattner const SCEV *BECount); 90e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner bool processLoopStoreOfLoopLoad(StoreInst *SI, unsigned StoreSize, 91e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner const SCEVAddRecExpr *StoreEv, 92e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner const SCEVAddRecExpr *LoadEv, 93e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner const SCEV *BECount); 94d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 95e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner /// This transformation requires natural loop information & requires that 96e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner /// loop preheaders be inserted into the CFG. 97e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner /// 98e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner virtual void getAnalysisUsage(AnalysisUsage &AU) const { 99e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner AU.addRequired<LoopInfo>(); 100e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner AU.addPreserved<LoopInfo>(); 101e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner AU.addRequiredID(LoopSimplifyID); 102e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner AU.addPreservedID(LoopSimplifyID); 103e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner AU.addRequiredID(LCSSAID); 104e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner AU.addPreservedID(LCSSAID); 1052e12f1ac6ebd49e5c41b7e9dcd802f3df40a1bc7Chris Lattner AU.addRequired<AliasAnalysis>(); 1062e12f1ac6ebd49e5c41b7e9dcd802f3df40a1bc7Chris Lattner AU.addPreserved<AliasAnalysis>(); 107e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner AU.addRequired<ScalarEvolution>(); 108e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner AU.addPreserved<ScalarEvolution>(); 109e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner AU.addPreserved<DominatorTree>(); 11062c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner AU.addRequired<DominatorTree>(); 111c19175c9d8d3c2663b682a7fe34bb22da370d5c1Chris Lattner AU.addRequired<TargetLibraryInfo>(); 112e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner } 113e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner }; 114e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner} 115e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner 116e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattnerchar LoopIdiomRecognize::ID = 0; 117e6bb649ec63059d795a31198c3c569c137e7ad59Chris LattnerINITIALIZE_PASS_BEGIN(LoopIdiomRecognize, "loop-idiom", "Recognize loop idioms", 118e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner false, false) 119e6bb649ec63059d795a31198c3c569c137e7ad59Chris LattnerINITIALIZE_PASS_DEPENDENCY(LoopInfo) 12062c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris LattnerINITIALIZE_PASS_DEPENDENCY(DominatorTree) 121e6bb649ec63059d795a31198c3c569c137e7ad59Chris LattnerINITIALIZE_PASS_DEPENDENCY(LoopSimplify) 122e6bb649ec63059d795a31198c3c569c137e7ad59Chris LattnerINITIALIZE_PASS_DEPENDENCY(LCSSA) 123e6bb649ec63059d795a31198c3c569c137e7ad59Chris LattnerINITIALIZE_PASS_DEPENDENCY(ScalarEvolution) 124c19175c9d8d3c2663b682a7fe34bb22da370d5c1Chris LattnerINITIALIZE_PASS_DEPENDENCY(TargetLibraryInfo) 1252e12f1ac6ebd49e5c41b7e9dcd802f3df40a1bc7Chris LattnerINITIALIZE_AG_DEPENDENCY(AliasAnalysis) 126e6bb649ec63059d795a31198c3c569c137e7ad59Chris LattnerINITIALIZE_PASS_END(LoopIdiomRecognize, "loop-idiom", "Recognize loop idioms", 127e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner false, false) 128e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner 129e6bb649ec63059d795a31198c3c569c137e7ad59Chris LattnerPass *llvm::createLoopIdiomPass() { return new LoopIdiomRecognize(); } 130e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner 1314f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner/// deleteDeadInstruction - Delete this instruction. Before we do, go through 1329f39188def2b4102817945522fac1209083efa06Chris Lattner/// and zero out all the operands of this instruction. If any of them become 1339f39188def2b4102817945522fac1209083efa06Chris Lattner/// dead, delete them and the computation tree that feeds them. 1349f39188def2b4102817945522fac1209083efa06Chris Lattner/// 1354f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattnerstatic void deleteDeadInstruction(Instruction *I, ScalarEvolution &SE) { 1369f39188def2b4102817945522fac1209083efa06Chris Lattner SmallVector<Instruction*, 32> NowDeadInsts; 137d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 1389f39188def2b4102817945522fac1209083efa06Chris Lattner NowDeadInsts.push_back(I); 139d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 1409f39188def2b4102817945522fac1209083efa06Chris Lattner // Before we touch this instruction, remove it from SE! 1419f39188def2b4102817945522fac1209083efa06Chris Lattner do { 1429f39188def2b4102817945522fac1209083efa06Chris Lattner Instruction *DeadInst = NowDeadInsts.pop_back_val(); 143d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 1449f39188def2b4102817945522fac1209083efa06Chris Lattner // This instruction is dead, zap it, in stages. Start by removing it from 1459f39188def2b4102817945522fac1209083efa06Chris Lattner // SCEV. 1469f39188def2b4102817945522fac1209083efa06Chris Lattner SE.forgetValue(DeadInst); 147d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 1489f39188def2b4102817945522fac1209083efa06Chris Lattner for (unsigned op = 0, e = DeadInst->getNumOperands(); op != e; ++op) { 1499f39188def2b4102817945522fac1209083efa06Chris Lattner Value *Op = DeadInst->getOperand(op); 1509f39188def2b4102817945522fac1209083efa06Chris Lattner DeadInst->setOperand(op, 0); 151d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 1529f39188def2b4102817945522fac1209083efa06Chris Lattner // If this operand just became dead, add it to the NowDeadInsts list. 1539f39188def2b4102817945522fac1209083efa06Chris Lattner if (!Op->use_empty()) continue; 154d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 1559f39188def2b4102817945522fac1209083efa06Chris Lattner if (Instruction *OpI = dyn_cast<Instruction>(Op)) 1569f39188def2b4102817945522fac1209083efa06Chris Lattner if (isInstructionTriviallyDead(OpI)) 1579f39188def2b4102817945522fac1209083efa06Chris Lattner NowDeadInsts.push_back(OpI); 1589f39188def2b4102817945522fac1209083efa06Chris Lattner } 159d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 1609f39188def2b4102817945522fac1209083efa06Chris Lattner DeadInst->eraseFromParent(); 161d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 1629f39188def2b4102817945522fac1209083efa06Chris Lattner } while (!NowDeadInsts.empty()); 1639f39188def2b4102817945522fac1209083efa06Chris Lattner} 1649f39188def2b4102817945522fac1209083efa06Chris Lattner 1654f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner/// deleteIfDeadInstruction - If the specified value is a dead instruction, 1664f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner/// delete it and any recursively used instructions. 1674f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattnerstatic void deleteIfDeadInstruction(Value *V, ScalarEvolution &SE) { 1684f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner if (Instruction *I = dyn_cast<Instruction>(V)) 1694f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner if (isInstructionTriviallyDead(I)) 170a5d950f673c29710d0e9e2afefe74b7003362a06Andrew Trick deleteDeadInstruction(I, SE); 1714f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner} 1724f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner 173e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattnerbool LoopIdiomRecognize::runOnLoop(Loop *L, LPPassManager &LPM) { 17422920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner CurLoop = L; 175d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 17671400b6afa3a650cac0ace1beb24a35518555f56Chad Rosier // Disable loop idiom recognition if the function's name is a common idiom. 17771400b6afa3a650cac0ace1beb24a35518555f56Chad Rosier StringRef Name = L->getHeader()->getParent()->getName(); 17871400b6afa3a650cac0ace1beb24a35518555f56Chad Rosier if (Name == "memset" || Name == "memcpy") 17971400b6afa3a650cac0ace1beb24a35518555f56Chad Rosier return false; 18071400b6afa3a650cac0ace1beb24a35518555f56Chad Rosier 18122920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner // The trip count of the loop must be analyzable. 18222920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner SE = &getAnalysis<ScalarEvolution>(); 18322920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner if (!SE->hasLoopInvariantBackedgeTakenCount(L)) 18422920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner return false; 18522920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner const SCEV *BECount = SE->getBackedgeTakenCount(L); 18622920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner if (isa<SCEVCouldNotCompute>(BECount)) return false; 187d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 1888e08e73f0e12c9e669f2d7d0a5c9213df3046c01Chris Lattner // If this loop executes exactly one time, then it should be peeled, not 1898e08e73f0e12c9e669f2d7d0a5c9213df3046c01Chris Lattner // optimized by this pass. 1908e08e73f0e12c9e669f2d7d0a5c9213df3046c01Chris Lattner if (const SCEVConstant *BECst = dyn_cast<SCEVConstant>(BECount)) 1918e08e73f0e12c9e669f2d7d0a5c9213df3046c01Chris Lattner if (BECst->getValue()->getValue() == 0) 1928e08e73f0e12c9e669f2d7d0a5c9213df3046c01Chris Lattner return false; 193d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 19422920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner // We require target data for now. 19522920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner TD = getAnalysisIfAvailable<TargetData>(); 19622920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner if (TD == 0) return false; 19762c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner 19862c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner DT = &getAnalysis<DominatorTree>(); 19962c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner LoopInfo &LI = getAnalysis<LoopInfo>(); 200c19175c9d8d3c2663b682a7fe34bb22da370d5c1Chris Lattner TLI = &getAnalysis<TargetLibraryInfo>(); 201d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 20262c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner SmallVector<BasicBlock*, 8> ExitBlocks; 20362c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner CurLoop->getUniqueExitBlocks(ExitBlocks); 20462c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner 20563f9c3c49ac7011e6366fbec42716f3f70f1beeeChris Lattner DEBUG(dbgs() << "loop-idiom Scanning: F[" 20663f9c3c49ac7011e6366fbec42716f3f70f1beeeChris Lattner << L->getHeader()->getParent()->getName() 20763f9c3c49ac7011e6366fbec42716f3f70f1beeeChris Lattner << "] Loop %" << L->getHeader()->getName() << "\n"); 208d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 20962c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner bool MadeChange = false; 21062c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner // Scan all the blocks in the loop that are not in subloops. 21162c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner for (Loop::block_iterator BI = L->block_begin(), E = L->block_end(); BI != E; 21262c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner ++BI) { 21362c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner // Ignore blocks in subloops. 21462c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner if (LI.getLoopFor(*BI) != CurLoop) 21562c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner continue; 216d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 21762c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner MadeChange |= runOnLoopBlock(*BI, BECount, ExitBlocks); 21862c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner } 21962c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner return MadeChange; 22062c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner} 221e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner 22262c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner/// runOnLoopBlock - Process the specified block, which lives in a counted loop 22362c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner/// with the specified backedge count. This block is known to be in the current 22462c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner/// loop and not in any subloops. 22562c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattnerbool LoopIdiomRecognize::runOnLoopBlock(BasicBlock *BB, const SCEV *BECount, 22662c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner SmallVectorImpl<BasicBlock*> &ExitBlocks) { 22762c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner // We can only promote stores in this block if they are unconditionally 22862c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner // executed in the loop. For a block to be unconditionally executed, it has 22962c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner // to dominate all the exit blocks of the loop. Verify this now. 23062c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner for (unsigned i = 0, e = ExitBlocks.size(); i != e; ++i) 23162c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner if (!DT->dominates(BB, ExitBlocks[i])) 23262c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner return false; 233d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 23422920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner bool MadeChange = false; 23522920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) { 236b7e9ef0ed1e246bd64d97a768555c8334c0d86e9Chris Lattner Instruction *Inst = I++; 237b7e9ef0ed1e246bd64d97a768555c8334c0d86e9Chris Lattner // Look for store instructions, which may be optimized to memset/memcpy. 238b7e9ef0ed1e246bd64d97a768555c8334c0d86e9Chris Lattner if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) { 239b7e9ef0ed1e246bd64d97a768555c8334c0d86e9Chris Lattner WeakVH InstPtr(I); 240b7e9ef0ed1e246bd64d97a768555c8334c0d86e9Chris Lattner if (!processLoopStore(SI, BECount)) continue; 241b7e9ef0ed1e246bd64d97a768555c8334c0d86e9Chris Lattner MadeChange = true; 242d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 243b7e9ef0ed1e246bd64d97a768555c8334c0d86e9Chris Lattner // If processing the store invalidated our iterator, start over from the 244e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner // top of the block. 245b7e9ef0ed1e246bd64d97a768555c8334c0d86e9Chris Lattner if (InstPtr == 0) 246b7e9ef0ed1e246bd64d97a768555c8334c0d86e9Chris Lattner I = BB->begin(); 247b7e9ef0ed1e246bd64d97a768555c8334c0d86e9Chris Lattner continue; 248b7e9ef0ed1e246bd64d97a768555c8334c0d86e9Chris Lattner } 249d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 250e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner // Look for memset instructions, which may be optimized to a larger memset. 251e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner if (MemSetInst *MSI = dyn_cast<MemSetInst>(Inst)) { 252e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner WeakVH InstPtr(I); 253e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner if (!processLoopMemSet(MSI, BECount)) continue; 254e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner MadeChange = true; 255d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 256e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner // If processing the memset invalidated our iterator, start over from the 257e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner // top of the block. 258e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner if (InstPtr == 0) 259e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner I = BB->begin(); 260e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner continue; 261e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner } 26222920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner } 263d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 26422920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner return MadeChange; 265e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner} 266e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner 26762c50fdf69064c0d086aedfadb6ceb7c303bbcb9Chris Lattner 268e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner/// processLoopStore - See if this store can be promoted to a memset or memcpy. 26922920b59864cac3b62d158fd4111cfda3c09c67aChris Lattnerbool LoopIdiomRecognize::processLoopStore(StoreInst *SI, const SCEV *BECount) { 2702bc3d52b9ab422ee9f7e42a1a4e3b818e623a5f7Eli Friedman if (!SI->isSimple()) return false; 271e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner 27222920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner Value *StoredVal = SI->getValueOperand(); 273a92ff91a967c63a2395a34c9e8331a7d50d6ab10Chris Lattner Value *StorePtr = SI->getPointerOperand(); 274d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 27595ae676bc89b4cb9166576b74f1220ab5b0ff0adChris Lattner // Reject stores that are so large that they overflow an unsigned. 27622920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner uint64_t SizeInBits = TD->getTypeSizeInBits(StoredVal->getType()); 27795ae676bc89b4cb9166576b74f1220ab5b0ff0adChris Lattner if ((SizeInBits & 7) || (SizeInBits >> 32) != 0) 27822920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner return false; 279d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 28022920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner // See if the pointer expression is an AddRec like {base,+,1} on the current 28122920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner // loop, which indicates a strided store. If we have something else, it's a 28222920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner // random store we can't handle. 283e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner const SCEVAddRecExpr *StoreEv = 284e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner dyn_cast<SCEVAddRecExpr>(SE->getSCEV(StorePtr)); 285e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner if (StoreEv == 0 || StoreEv->getLoop() != CurLoop || !StoreEv->isAffine()) 28622920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner return false; 28722920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner 28822920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner // Check to see if the stride matches the size of the store. If so, then we 28922920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner // know that every byte is touched in the loop. 290d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick unsigned StoreSize = (unsigned)SizeInBits >> 3; 291e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner const SCEVConstant *Stride = dyn_cast<SCEVConstant>(StoreEv->getOperand(1)); 292d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 293408b534e431cc317f1116cd78df96da2af7cafd9Chris Lattner if (Stride == 0 || StoreSize != Stride->getValue()->getValue()) { 294408b534e431cc317f1116cd78df96da2af7cafd9Chris Lattner // TODO: Could also handle negative stride here someday, that will require 295408b534e431cc317f1116cd78df96da2af7cafd9Chris Lattner // the validity check in mayLoopAccessLocation to be updated though. 296408b534e431cc317f1116cd78df96da2af7cafd9Chris Lattner // Enable this to print exact negative strides. 2970e68cee62f251c45df92c71ca536142bc7d82631Chris Lattner if (0 && Stride && StoreSize == -Stride->getValue()->getValue()) { 298408b534e431cc317f1116cd78df96da2af7cafd9Chris Lattner dbgs() << "NEGATIVE STRIDE: " << *SI << "\n"; 299408b534e431cc317f1116cd78df96da2af7cafd9Chris Lattner dbgs() << "BB: " << *SI->getParent(); 300408b534e431cc317f1116cd78df96da2af7cafd9Chris Lattner } 301d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 30222920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner return false; 303408b534e431cc317f1116cd78df96da2af7cafd9Chris Lattner } 3043a393728a62122d7009d8e2cbe52a221874e576aChris Lattner 3053a393728a62122d7009d8e2cbe52a221874e576aChris Lattner // See if we can optimize just this store in isolation. 3063a393728a62122d7009d8e2cbe52a221874e576aChris Lattner if (processLoopStridedStore(StorePtr, StoreSize, SI->getAlignment(), 3073a393728a62122d7009d8e2cbe52a221874e576aChris Lattner StoredVal, SI, StoreEv, BECount)) 3083a393728a62122d7009d8e2cbe52a221874e576aChris Lattner return true; 309a92ff91a967c63a2395a34c9e8331a7d50d6ab10Chris Lattner 310e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner // If the stored value is a strided load in the same loop with the same stride 311e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner // this this may be transformable into a memcpy. This kicks in for stuff like 312e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner // for (i) A[i] = B[i]; 313e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(StoredVal)) { 314e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner const SCEVAddRecExpr *LoadEv = 315e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner dyn_cast<SCEVAddRecExpr>(SE->getSCEV(LI->getOperand(0))); 316e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner if (LoadEv && LoadEv->getLoop() == CurLoop && LoadEv->isAffine() && 3172bc3d52b9ab422ee9f7e42a1a4e3b818e623a5f7Eli Friedman StoreEv->getOperand(1) == LoadEv->getOperand(1) && LI->isSimple()) 318e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner if (processLoopStoreOfLoopLoad(SI, StoreSize, StoreEv, LoadEv, BECount)) 319e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner return true; 320e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner } 3214ce31fb57412b16cd61337ba41c60112dfbecfb6Chris Lattner //errs() << "UNHANDLED strided store: " << *StoreEv << " - " << *SI << "\n"; 32222920b59864cac3b62d158fd4111cfda3c09c67aChris Lattner 323e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner return false; 324e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner} 325e6bb649ec63059d795a31198c3c569c137e7ad59Chris Lattner 326e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner/// processLoopMemSet - See if this memset can be promoted to a large memset. 327e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattnerbool LoopIdiomRecognize:: 328e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris LattnerprocessLoopMemSet(MemSetInst *MSI, const SCEV *BECount) { 329e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner // We can only handle non-volatile memsets with a constant size. 330e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner if (MSI->isVolatile() || !isa<ConstantInt>(MSI->getLength())) return false; 331e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner 332c19175c9d8d3c2663b682a7fe34bb22da370d5c1Chris Lattner // If we're not allowed to hack on memset, we fail. 333c19175c9d8d3c2663b682a7fe34bb22da370d5c1Chris Lattner if (!TLI->has(LibFunc::memset)) 334c19175c9d8d3c2663b682a7fe34bb22da370d5c1Chris Lattner return false; 335d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 336e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner Value *Pointer = MSI->getDest(); 337d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 338e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner // See if the pointer expression is an AddRec like {base,+,1} on the current 339e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner // loop, which indicates a strided store. If we have something else, it's a 340e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner // random store we can't handle. 341e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner const SCEVAddRecExpr *Ev = dyn_cast<SCEVAddRecExpr>(SE->getSCEV(Pointer)); 342e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner if (Ev == 0 || Ev->getLoop() != CurLoop || !Ev->isAffine()) 343e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner return false; 344e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner 345e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner // Reject memsets that are so large that they overflow an unsigned. 346e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner uint64_t SizeInBytes = cast<ConstantInt>(MSI->getLength())->getZExtValue(); 347e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner if ((SizeInBytes >> 32) != 0) 348e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner return false; 349d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 350e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner // Check to see if the stride matches the size of the memset. If so, then we 351e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner // know that every byte is touched in the loop. 352e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner const SCEVConstant *Stride = dyn_cast<SCEVConstant>(Ev->getOperand(1)); 353d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 354e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner // TODO: Could also handle negative stride here someday, that will require the 355e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner // validity check in mayLoopAccessLocation to be updated though. 356e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner if (Stride == 0 || MSI->getLength() != Stride->getValue()) 357e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner return false; 358d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 3593a393728a62122d7009d8e2cbe52a221874e576aChris Lattner return processLoopStridedStore(Pointer, (unsigned)SizeInBytes, 3603a393728a62122d7009d8e2cbe52a221874e576aChris Lattner MSI->getAlignment(), MSI->getValue(), 3613a393728a62122d7009d8e2cbe52a221874e576aChris Lattner MSI, Ev, BECount); 362e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner} 363e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner 364e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner 36563f9c3c49ac7011e6366fbec42716f3f70f1beeeChris Lattner/// mayLoopAccessLocation - Return true if the specified loop might access the 36663f9c3c49ac7011e6366fbec42716f3f70f1beeeChris Lattner/// specified pointer location, which is a loop-strided access. The 'Access' 36763f9c3c49ac7011e6366fbec42716f3f70f1beeeChris Lattner/// argument specifies what the verboten forms of access are (read or write). 36863f9c3c49ac7011e6366fbec42716f3f70f1beeeChris Lattnerstatic bool mayLoopAccessLocation(Value *Ptr,AliasAnalysis::ModRefResult Access, 36963f9c3c49ac7011e6366fbec42716f3f70f1beeeChris Lattner Loop *L, const SCEV *BECount, 370e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner unsigned StoreSize, AliasAnalysis &AA, 371e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner Instruction *IgnoredStore) { 37230980b68151a1c1527306aa0f39e3b297af05583Chris Lattner // Get the location that may be stored across the loop. Since the access is 37330980b68151a1c1527306aa0f39e3b297af05583Chris Lattner // strided positively through memory, we say that the modified location starts 37430980b68151a1c1527306aa0f39e3b297af05583Chris Lattner // at the pointer and has infinite size. 375a64cbf067d6315522d13b606774bbadb4e328d1bChris Lattner uint64_t AccessSize = AliasAnalysis::UnknownSize; 376a64cbf067d6315522d13b606774bbadb4e328d1bChris Lattner 377a64cbf067d6315522d13b606774bbadb4e328d1bChris Lattner // If the loop iterates a fixed number of times, we can refine the access size 378a64cbf067d6315522d13b606774bbadb4e328d1bChris Lattner // to be exactly the size of the memset, which is (BECount+1)*StoreSize 379a64cbf067d6315522d13b606774bbadb4e328d1bChris Lattner if (const SCEVConstant *BECst = dyn_cast<SCEVConstant>(BECount)) 380a64cbf067d6315522d13b606774bbadb4e328d1bChris Lattner AccessSize = (BECst->getValue()->getZExtValue()+1)*StoreSize; 381d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 382a64cbf067d6315522d13b606774bbadb4e328d1bChris Lattner // TODO: For this to be really effective, we have to dive into the pointer 383a64cbf067d6315522d13b606774bbadb4e328d1bChris Lattner // operand in the store. Store to &A[i] of 100 will always return may alias 384a64cbf067d6315522d13b606774bbadb4e328d1bChris Lattner // with store of &A[100], we need to StoreLoc to be "A" with size of 100, 385a64cbf067d6315522d13b606774bbadb4e328d1bChris Lattner // which will then no-alias a store to &A[100]. 386e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner AliasAnalysis::Location StoreLoc(Ptr, AccessSize); 38730980b68151a1c1527306aa0f39e3b297af05583Chris Lattner 38830980b68151a1c1527306aa0f39e3b297af05583Chris Lattner for (Loop::block_iterator BI = L->block_begin(), E = L->block_end(); BI != E; 38930980b68151a1c1527306aa0f39e3b297af05583Chris Lattner ++BI) 39030980b68151a1c1527306aa0f39e3b297af05583Chris Lattner for (BasicBlock::iterator I = (*BI)->begin(), E = (*BI)->end(); I != E; ++I) 391e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner if (&*I != IgnoredStore && 39263f9c3c49ac7011e6366fbec42716f3f70f1beeeChris Lattner (AA.getModRefInfo(I, StoreLoc) & Access)) 39330980b68151a1c1527306aa0f39e3b297af05583Chris Lattner return true; 39430980b68151a1c1527306aa0f39e3b297af05583Chris Lattner 39530980b68151a1c1527306aa0f39e3b297af05583Chris Lattner return false; 39630980b68151a1c1527306aa0f39e3b297af05583Chris Lattner} 39730980b68151a1c1527306aa0f39e3b297af05583Chris Lattner 3983a393728a62122d7009d8e2cbe52a221874e576aChris Lattner/// getMemSetPatternValue - If a strided store of the specified value is safe to 3993a393728a62122d7009d8e2cbe52a221874e576aChris Lattner/// turn into a memset_pattern16, return a ConstantArray of 16 bytes that should 4003a393728a62122d7009d8e2cbe52a221874e576aChris Lattner/// be passed in. Otherwise, return null. 4013a393728a62122d7009d8e2cbe52a221874e576aChris Lattner/// 4023a393728a62122d7009d8e2cbe52a221874e576aChris Lattner/// Note that we don't ever attempt to use memset_pattern8 or 4, because these 4033a393728a62122d7009d8e2cbe52a221874e576aChris Lattner/// just replicate their input array and then pass on to memset_pattern16. 4043a393728a62122d7009d8e2cbe52a221874e576aChris Lattnerstatic Constant *getMemSetPatternValue(Value *V, const TargetData &TD) { 4053a393728a62122d7009d8e2cbe52a221874e576aChris Lattner // If the value isn't a constant, we can't promote it to being in a constant 4063a393728a62122d7009d8e2cbe52a221874e576aChris Lattner // array. We could theoretically do a store to an alloca or something, but 4073a393728a62122d7009d8e2cbe52a221874e576aChris Lattner // that doesn't seem worthwhile. 4083a393728a62122d7009d8e2cbe52a221874e576aChris Lattner Constant *C = dyn_cast<Constant>(V); 4093a393728a62122d7009d8e2cbe52a221874e576aChris Lattner if (C == 0) return 0; 410d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 4113a393728a62122d7009d8e2cbe52a221874e576aChris Lattner // Only handle simple values that are a power of two bytes in size. 4123a393728a62122d7009d8e2cbe52a221874e576aChris Lattner uint64_t Size = TD.getTypeSizeInBits(V->getType()); 4133a393728a62122d7009d8e2cbe52a221874e576aChris Lattner if (Size == 0 || (Size & 7) || (Size & (Size-1))) 4143a393728a62122d7009d8e2cbe52a221874e576aChris Lattner return 0; 415d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 41680e8b506b8134d63dc3cb6211cccc34be4b19d40Chris Lattner // Don't care enough about darwin/ppc to implement this. 41780e8b506b8134d63dc3cb6211cccc34be4b19d40Chris Lattner if (TD.isBigEndian()) 41880e8b506b8134d63dc3cb6211cccc34be4b19d40Chris Lattner return 0; 4193a393728a62122d7009d8e2cbe52a221874e576aChris Lattner 4203a393728a62122d7009d8e2cbe52a221874e576aChris Lattner // Convert to size in bytes. 4213a393728a62122d7009d8e2cbe52a221874e576aChris Lattner Size /= 8; 422c19175c9d8d3c2663b682a7fe34bb22da370d5c1Chris Lattner 4233a393728a62122d7009d8e2cbe52a221874e576aChris Lattner // TODO: If CI is larger than 16-bytes, we can try slicing it in half to see 42480e8b506b8134d63dc3cb6211cccc34be4b19d40Chris Lattner // if the top and bottom are the same (e.g. for vectors and large integers). 4253a393728a62122d7009d8e2cbe52a221874e576aChris Lattner if (Size > 16) return 0; 426d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 42780e8b506b8134d63dc3cb6211cccc34be4b19d40Chris Lattner // If the constant is exactly 16 bytes, just use it. 42880e8b506b8134d63dc3cb6211cccc34be4b19d40Chris Lattner if (Size == 16) return C; 42980e8b506b8134d63dc3cb6211cccc34be4b19d40Chris Lattner 43080e8b506b8134d63dc3cb6211cccc34be4b19d40Chris Lattner // Otherwise, we'll use an array of the constants. 43180e8b506b8134d63dc3cb6211cccc34be4b19d40Chris Lattner unsigned ArraySize = 16/Size; 43280e8b506b8134d63dc3cb6211cccc34be4b19d40Chris Lattner ArrayType *AT = ArrayType::get(V->getType(), ArraySize); 43380e8b506b8134d63dc3cb6211cccc34be4b19d40Chris Lattner return ConstantArray::get(AT, std::vector<Constant*>(ArraySize, C)); 4343a393728a62122d7009d8e2cbe52a221874e576aChris Lattner} 4353a393728a62122d7009d8e2cbe52a221874e576aChris Lattner 4363a393728a62122d7009d8e2cbe52a221874e576aChris Lattner 4373a393728a62122d7009d8e2cbe52a221874e576aChris Lattner/// processLoopStridedStore - We see a strided store of some value. If we can 4383a393728a62122d7009d8e2cbe52a221874e576aChris Lattner/// transform this into a memset or memset_pattern in the loop preheader, do so. 4393a393728a62122d7009d8e2cbe52a221874e576aChris Lattnerbool LoopIdiomRecognize:: 4403a393728a62122d7009d8e2cbe52a221874e576aChris LattnerprocessLoopStridedStore(Value *DestPtr, unsigned StoreSize, 4413a393728a62122d7009d8e2cbe52a221874e576aChris Lattner unsigned StoreAlignment, Value *StoredVal, 4423a393728a62122d7009d8e2cbe52a221874e576aChris Lattner Instruction *TheStore, const SCEVAddRecExpr *Ev, 4433a393728a62122d7009d8e2cbe52a221874e576aChris Lattner const SCEV *BECount) { 444d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 4453a393728a62122d7009d8e2cbe52a221874e576aChris Lattner // If the stored value is a byte-wise value (like i32 -1), then it may be 4463a393728a62122d7009d8e2cbe52a221874e576aChris Lattner // turned into a memset of i8 -1, assuming that all the consecutive bytes 4473a393728a62122d7009d8e2cbe52a221874e576aChris Lattner // are stored. A store of i32 0x01020304 can never be turned into a memset, 4483a393728a62122d7009d8e2cbe52a221874e576aChris Lattner // but it can be turned into memset_pattern if the target supports it. 4493a393728a62122d7009d8e2cbe52a221874e576aChris Lattner Value *SplatValue = isBytewiseValue(StoredVal); 4503a393728a62122d7009d8e2cbe52a221874e576aChris Lattner Constant *PatternValue = 0; 451d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 4523a393728a62122d7009d8e2cbe52a221874e576aChris Lattner // If we're allowed to form a memset, and the stored value would be acceptable 4533a393728a62122d7009d8e2cbe52a221874e576aChris Lattner // for memset, use it. 4543a393728a62122d7009d8e2cbe52a221874e576aChris Lattner if (SplatValue && TLI->has(LibFunc::memset) && 4553a393728a62122d7009d8e2cbe52a221874e576aChris Lattner // Verify that the stored value is loop invariant. If not, we can't 4563a393728a62122d7009d8e2cbe52a221874e576aChris Lattner // promote the memset. 4573a393728a62122d7009d8e2cbe52a221874e576aChris Lattner CurLoop->isLoopInvariant(SplatValue)) { 4583a393728a62122d7009d8e2cbe52a221874e576aChris Lattner // Keep and use SplatValue. 4593a393728a62122d7009d8e2cbe52a221874e576aChris Lattner PatternValue = 0; 4603a393728a62122d7009d8e2cbe52a221874e576aChris Lattner } else if (TLI->has(LibFunc::memset_pattern16) && 4613a393728a62122d7009d8e2cbe52a221874e576aChris Lattner (PatternValue = getMemSetPatternValue(StoredVal, *TD))) { 4623a393728a62122d7009d8e2cbe52a221874e576aChris Lattner // It looks like we can use PatternValue! 4633a393728a62122d7009d8e2cbe52a221874e576aChris Lattner SplatValue = 0; 4643a393728a62122d7009d8e2cbe52a221874e576aChris Lattner } else { 4653a393728a62122d7009d8e2cbe52a221874e576aChris Lattner // Otherwise, this isn't an idiom we can transform. For example, we can't 4665ac7c7da3ebfd1aa95226aeefb8cfa3ba34fd72aEli Friedman // do anything with a 3-byte store. 467bafa117e8f2e3532f391227ebc9d4513b17edbadChris Lattner return false; 4683a393728a62122d7009d8e2cbe52a221874e576aChris Lattner } 469d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 470a92ff91a967c63a2395a34c9e8331a7d50d6ab10Chris Lattner // The trip count of the loop and the base pointer of the addrec SCEV is 471a92ff91a967c63a2395a34c9e8331a7d50d6ab10Chris Lattner // guaranteed to be loop invariant, which means that it should dominate the 4724f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner // header. This allows us to insert code for it in the preheader. 4734f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner BasicBlock *Preheader = CurLoop->getLoopPreheader(); 4744f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner IRBuilder<> Builder(Preheader->getTerminator()); 4755e7645be4c9dd2193add44d30b5fef8036d7a3ceAndrew Trick SCEVExpander Expander(*SE, "loop-idiom"); 476a5d950f673c29710d0e9e2afefe74b7003362a06Andrew Trick 4774f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner // Okay, we have a strided store "p[i]" of a splattable value. We can turn 4784f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner // this into a memset in the loop preheader now if we want. However, this 4794f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner // would be unsafe to do if there is anything else in the loop that may read 4804f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner // or write to the aliased location. Check for any overlap by generating the 4814f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner // base pointer and checking the region. 482e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner unsigned AddrSpace = cast<PointerType>(DestPtr->getType())->getAddressSpace(); 483d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick Value *BasePtr = 484a92ff91a967c63a2395a34c9e8331a7d50d6ab10Chris Lattner Expander.expandCodeFor(Ev->getStart(), Builder.getInt8PtrTy(AddrSpace), 485a92ff91a967c63a2395a34c9e8331a7d50d6ab10Chris Lattner Preheader->getTerminator()); 486d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 4874f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner 4884f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner if (mayLoopAccessLocation(BasePtr, AliasAnalysis::ModRef, 4894f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner CurLoop, BECount, 4904f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner StoreSize, getAnalysis<AliasAnalysis>(), TheStore)){ 4914f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner Expander.clear(); 4924f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner // If we generated new code for the base pointer, clean up. 4934f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner deleteIfDeadInstruction(BasePtr, *SE); 4944f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner return false; 4954f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner } 496a5d950f673c29710d0e9e2afefe74b7003362a06Andrew Trick 4974f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner // Okay, everything looks good, insert the memset. 4984f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner 499a92ff91a967c63a2395a34c9e8331a7d50d6ab10Chris Lattner // The # stored bytes is (BECount+1)*Size. Expand the trip count out to 500a92ff91a967c63a2395a34c9e8331a7d50d6ab10Chris Lattner // pointer size if it isn't already. 501db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *IntPtr = TD->getIntPtrType(DestPtr->getContext()); 5027c90b90f4e9b0c421f0e45d7de03f6edce113a90Chris Lattner BECount = SE->getTruncateOrZeroExtend(BECount, IntPtr); 503d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 504a92ff91a967c63a2395a34c9e8331a7d50d6ab10Chris Lattner const SCEV *NumBytesS = SE->getAddExpr(BECount, SE->getConstant(IntPtr, 1), 5053228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagNUW); 506a92ff91a967c63a2395a34c9e8331a7d50d6ab10Chris Lattner if (StoreSize != 1) 507a92ff91a967c63a2395a34c9e8331a7d50d6ab10Chris Lattner NumBytesS = SE->getMulExpr(NumBytesS, SE->getConstant(IntPtr, StoreSize), 5083228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagNUW); 509d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 510d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick Value *NumBytes = 511a92ff91a967c63a2395a34c9e8331a7d50d6ab10Chris Lattner Expander.expandCodeFor(NumBytesS, IntPtr, Preheader->getTerminator()); 512d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 513cd77a50e638be5e7153ebe2a8ba875de7df48beaDevang Patel CallInst *NewCall; 5143a393728a62122d7009d8e2cbe52a221874e576aChris Lattner if (SplatValue) 5153a393728a62122d7009d8e2cbe52a221874e576aChris Lattner NewCall = Builder.CreateMemSet(BasePtr, SplatValue,NumBytes,StoreAlignment); 5163a393728a62122d7009d8e2cbe52a221874e576aChris Lattner else { 5173a393728a62122d7009d8e2cbe52a221874e576aChris Lattner Module *M = TheStore->getParent()->getParent()->getParent(); 5183a393728a62122d7009d8e2cbe52a221874e576aChris Lattner Value *MSP = M->getOrInsertFunction("memset_pattern16", 5193a393728a62122d7009d8e2cbe52a221874e576aChris Lattner Builder.getVoidTy(), 520d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick Builder.getInt8PtrTy(), 5213a393728a62122d7009d8e2cbe52a221874e576aChris Lattner Builder.getInt8PtrTy(), IntPtr, 5223a393728a62122d7009d8e2cbe52a221874e576aChris Lattner (void*)0); 523d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 5243a393728a62122d7009d8e2cbe52a221874e576aChris Lattner // Otherwise we should form a memset_pattern16. PatternValue is known to be 5253a393728a62122d7009d8e2cbe52a221874e576aChris Lattner // an constant array of 16-bytes. Plop the value into a mergable global. 5263a393728a62122d7009d8e2cbe52a221874e576aChris Lattner GlobalVariable *GV = new GlobalVariable(*M, PatternValue->getType(), true, 5273a393728a62122d7009d8e2cbe52a221874e576aChris Lattner GlobalValue::InternalLinkage, 5283a393728a62122d7009d8e2cbe52a221874e576aChris Lattner PatternValue, ".memset_pattern"); 5293a393728a62122d7009d8e2cbe52a221874e576aChris Lattner GV->setUnnamedAddr(true); // Ok to merge these. 5303a393728a62122d7009d8e2cbe52a221874e576aChris Lattner GV->setAlignment(16); 53180e8b506b8134d63dc3cb6211cccc34be4b19d40Chris Lattner Value *PatternPtr = ConstantExpr::getBitCast(GV, Builder.getInt8PtrTy()); 5323a393728a62122d7009d8e2cbe52a221874e576aChris Lattner NewCall = Builder.CreateCall3(MSP, BasePtr, PatternPtr, NumBytes); 5333a393728a62122d7009d8e2cbe52a221874e576aChris Lattner } 534d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 535a92ff91a967c63a2395a34c9e8331a7d50d6ab10Chris Lattner DEBUG(dbgs() << " Formed memset: " << *NewCall << "\n" 536e41d3c015ce5cafde305d9a6d9baaae1c41bf46aChris Lattner << " from store to: " << *Ev << " at: " << *TheStore << "\n"); 537cd77a50e638be5e7153ebe2a8ba875de7df48beaDevang Patel NewCall->setDebugLoc(TheStore->getDebugLoc()); 538d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 5399f39188def2b4102817945522fac1209083efa06Chris Lattner // Okay, the memset has been formed. Zap the original store and anything that 5409f39188def2b4102817945522fac1209083efa06Chris Lattner // feeds into it. 5414f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner deleteDeadInstruction(TheStore, *SE); 5424ce31fb57412b16cd61337ba41c60112dfbecfb6Chris Lattner ++NumMemSet; 543a92ff91a967c63a2395a34c9e8331a7d50d6ab10Chris Lattner return true; 544a92ff91a967c63a2395a34c9e8331a7d50d6ab10Chris Lattner} 545a92ff91a967c63a2395a34c9e8331a7d50d6ab10Chris Lattner 546e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner/// processLoopStoreOfLoopLoad - We see a strided store whose value is a 547e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner/// same-strided load. 548e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattnerbool LoopIdiomRecognize:: 549e2c43920919c6fe376613d1d8331897dc1ba3d57Chris LattnerprocessLoopStoreOfLoopLoad(StoreInst *SI, unsigned StoreSize, 550e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner const SCEVAddRecExpr *StoreEv, 551e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner const SCEVAddRecExpr *LoadEv, 552e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner const SCEV *BECount) { 553c19175c9d8d3c2663b682a7fe34bb22da370d5c1Chris Lattner // If we're not allowed to form memcpy, we fail. 554c19175c9d8d3c2663b682a7fe34bb22da370d5c1Chris Lattner if (!TLI->has(LibFunc::memcpy)) 555c19175c9d8d3c2663b682a7fe34bb22da370d5c1Chris Lattner return false; 556d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 557e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner LoadInst *LI = cast<LoadInst>(SI->getValueOperand()); 558d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 5594f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner // The trip count of the loop and the base pointer of the addrec SCEV is 5604f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner // guaranteed to be loop invariant, which means that it should dominate the 5614f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner // header. This allows us to insert code for it in the preheader. 5624f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner BasicBlock *Preheader = CurLoop->getLoopPreheader(); 5634f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner IRBuilder<> Builder(Preheader->getTerminator()); 5645e7645be4c9dd2193add44d30b5fef8036d7a3ceAndrew Trick SCEVExpander Expander(*SE, "loop-idiom"); 565a5d950f673c29710d0e9e2afefe74b7003362a06Andrew Trick 566e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner // Okay, we have a strided store "p[i]" of a loaded value. We can turn 567bdce5720ad878259544e6a4e3621dac32cf2d134Chris Lattner // this into a memcpy in the loop preheader now if we want. However, this 568e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner // would be unsafe to do if there is anything else in the loop that may read 5694f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner // or write the memory region we're storing to. This includes the load that 5704f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner // feeds the stores. Check for an alias by generating the base address and 5714f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner // checking everything. 5724f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner Value *StoreBasePtr = 5734f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner Expander.expandCodeFor(StoreEv->getStart(), 5744f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner Builder.getInt8PtrTy(SI->getPointerAddressSpace()), 5754f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner Preheader->getTerminator()); 576a5d950f673c29710d0e9e2afefe74b7003362a06Andrew Trick 5774f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner if (mayLoopAccessLocation(StoreBasePtr, AliasAnalysis::ModRef, 57863f9c3c49ac7011e6366fbec42716f3f70f1beeeChris Lattner CurLoop, BECount, StoreSize, 5794f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner getAnalysis<AliasAnalysis>(), SI)) { 5804f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner Expander.clear(); 5814f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner // If we generated new code for the base pointer, clean up. 5824f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner deleteIfDeadInstruction(StoreBasePtr, *SE); 58363f9c3c49ac7011e6366fbec42716f3f70f1beeeChris Lattner return false; 5844f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner } 58563f9c3c49ac7011e6366fbec42716f3f70f1beeeChris Lattner 58663f9c3c49ac7011e6366fbec42716f3f70f1beeeChris Lattner // For a memcpy, we have to make sure that the input array is not being 58763f9c3c49ac7011e6366fbec42716f3f70f1beeeChris Lattner // mutated by the loop. 588d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick Value *LoadBasePtr = 589e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner Expander.expandCodeFor(LoadEv->getStart(), 590e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner Builder.getInt8PtrTy(LI->getPointerAddressSpace()), 591e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner Preheader->getTerminator()); 5924f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner 5934f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner if (mayLoopAccessLocation(LoadBasePtr, AliasAnalysis::Mod, CurLoop, BECount, 5944f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner StoreSize, getAnalysis<AliasAnalysis>(), SI)) { 5954f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner Expander.clear(); 5964f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner // If we generated new code for the base pointer, clean up. 5974f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner deleteIfDeadInstruction(LoadBasePtr, *SE); 5984f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner deleteIfDeadInstruction(StoreBasePtr, *SE); 5994f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner return false; 6004f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner } 601a5d950f673c29710d0e9e2afefe74b7003362a06Andrew Trick 6024f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner // Okay, everything is safe, we can transform this! 603a5d950f673c29710d0e9e2afefe74b7003362a06Andrew Trick 604d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 605e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner // The # stored bytes is (BECount+1)*Size. Expand the trip count out to 606e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner // pointer size if it isn't already. 607db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *IntPtr = TD->getIntPtrType(SI->getContext()); 6087c90b90f4e9b0c421f0e45d7de03f6edce113a90Chris Lattner BECount = SE->getTruncateOrZeroExtend(BECount, IntPtr); 609d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 610e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner const SCEV *NumBytesS = SE->getAddExpr(BECount, SE->getConstant(IntPtr, 1), 6113228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagNUW); 612e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner if (StoreSize != 1) 613e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner NumBytesS = SE->getMulExpr(NumBytesS, SE->getConstant(IntPtr, StoreSize), 6143228cc259b5ca00e46af36da369a451f5736cbf4Andrew Trick SCEV::FlagNUW); 615d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 616e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner Value *NumBytes = 617e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner Expander.expandCodeFor(NumBytesS, IntPtr, Preheader->getTerminator()); 618d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 619af35841f2e346f9259606886698c188280406cdbDevang Patel CallInst *NewCall = 620e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner Builder.CreateMemCpy(StoreBasePtr, LoadBasePtr, NumBytes, 621e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner std::min(SI->getAlignment(), LI->getAlignment())); 622af35841f2e346f9259606886698c188280406cdbDevang Patel NewCall->setDebugLoc(SI->getDebugLoc()); 623d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 624e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner DEBUG(dbgs() << " Formed memcpy: " << *NewCall << "\n" 625e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner << " from load ptr=" << *LoadEv << " at: " << *LI << "\n" 626e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner << " from store ptr=" << *StoreEv << " at: " << *SI << "\n"); 627a5d950f673c29710d0e9e2afefe74b7003362a06Andrew Trick 628d99b39e43b6e8263c80425c99d4e924f08e86e43Andrew Trick 629e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner // Okay, the memset has been formed. Zap the original store and anything that 630e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner // feeds into it. 6314f81b5419295cfc26a1349d6c23a55c6d2a683e1Chris Lattner deleteDeadInstruction(SI, *SE); 6324ce31fb57412b16cd61337ba41c60112dfbecfb6Chris Lattner ++NumMemCpy; 633e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner return true; 634e2c43920919c6fe376613d1d8331897dc1ba3d57Chris Lattner} 635