ScalarReplAggregates.cpp revision 88e6dc8bf14e8a98888f62173a6581386b8d29a0
1ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner//===- ScalarReplAggregates.cpp - Scalar Replacement of Aggregates --------===// 2fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman// 3b576c94c15af9a440f69d9d03c2afead7971118cJohn Criswell// The LLVM Compiler Infrastructure 4b576c94c15af9a440f69d9d03c2afead7971118cJohn Criswell// 54ee451de366474b9c228b4e5fa573795a715216dChris Lattner// This file is distributed under the University of Illinois Open Source 64ee451de366474b9c228b4e5fa573795a715216dChris Lattner// License. See LICENSE.TXT for details. 7fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman// 8b576c94c15af9a440f69d9d03c2afead7971118cJohn Criswell//===----------------------------------------------------------------------===// 9ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner// 10ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner// This transformation implements the well known scalar replacement of 11ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner// aggregates transformation. This xform breaks up alloca instructions of 12ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner// aggregate type (structure or array) into individual alloca instructions for 1338aec325604635380421a27e39ab06d55ed2458dChris Lattner// each member (if possible). Then, if possible, it transforms the individual 1438aec325604635380421a27e39ab06d55ed2458dChris Lattner// alloca instructions into nice clean scalar SSA form. 1538aec325604635380421a27e39ab06d55ed2458dChris Lattner// 1638aec325604635380421a27e39ab06d55ed2458dChris Lattner// This combines a simple SRoA algorithm with the Mem2Reg algorithm because 1738aec325604635380421a27e39ab06d55ed2458dChris Lattner// often interact, especially for C++ programs. As such, iterating between 1838aec325604635380421a27e39ab06d55ed2458dChris Lattner// SRoA, then Mem2Reg until we run out of things to promote works well. 19ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner// 20ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner//===----------------------------------------------------------------------===// 21ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 220e5f499638c8d277b9dc4a4385712177c53b5681Chris Lattner#define DEBUG_TYPE "scalarrepl" 23ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner#include "llvm/Transforms/Scalar.h" 2438aec325604635380421a27e39ab06d55ed2458dChris Lattner#include "llvm/Constants.h" 2538aec325604635380421a27e39ab06d55ed2458dChris Lattner#include "llvm/DerivedTypes.h" 26ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner#include "llvm/Function.h" 2779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner#include "llvm/GlobalVariable.h" 28d8e1eea678833cc2b15e4ea69a5a403ba9c3b013Misha Brukman#include "llvm/Instructions.h" 29372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner#include "llvm/IntrinsicInst.h" 30372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner#include "llvm/Pass.h" 3138aec325604635380421a27e39ab06d55ed2458dChris Lattner#include "llvm/Analysis/Dominators.h" 3238aec325604635380421a27e39ab06d55ed2458dChris Lattner#include "llvm/Target/TargetData.h" 3338aec325604635380421a27e39ab06d55ed2458dChris Lattner#include "llvm/Transforms/Utils/PromoteMemToReg.h" 349525528a7dc5462b6374d38c81ba5c07b11741feChris Lattner#include "llvm/Support/Debug.h" 35a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner#include "llvm/Support/GetElementPtrTypeIterator.h" 36a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner#include "llvm/Support/MathExtras.h" 37a4f0b3a084d120cfc5b5bb06f64b222f5cb72740Chris Lattner#include "llvm/Support/Compiler.h" 381ccd185cb49d81465a2901622e58ceae046d1d83Chris Lattner#include "llvm/ADT/SmallVector.h" 39551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/Statistic.h" 40551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/StringExtras.h" 41d8664730942beb911327336d1f9db8e7efcd6813Chris Lattnerusing namespace llvm; 42d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 430e5f499638c8d277b9dc4a4385712177c53b5681Chris LattnerSTATISTIC(NumReplaced, "Number of allocas broken up"); 440e5f499638c8d277b9dc4a4385712177c53b5681Chris LattnerSTATISTIC(NumPromoted, "Number of allocas promoted"); 450e5f499638c8d277b9dc4a4385712177c53b5681Chris LattnerSTATISTIC(NumConverted, "Number of aggregates converted to scalar"); 4679b3bd395dc3303cde65e18e0524ed2f70268c99Chris LattnerSTATISTIC(NumGlobals, "Number of allocas copied from constant global"); 47ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 480e5f499638c8d277b9dc4a4385712177c53b5681Chris Lattnernamespace { 499525528a7dc5462b6374d38c81ba5c07b11741feChris Lattner struct VISIBILITY_HIDDEN SROA : public FunctionPass { 50ecd94c804a563f2a86572dcf1d2e81f397e19daaNick Lewycky static char ID; // Pass identification, replacement for typeid 51c2bbfc18e9adbbdcf5b3375d8d25e2452f7df7f1Dan Gohman explicit SROA(signed T = -1) : FunctionPass((intptr_t)&ID) { 52ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel if (T == -1) 53b0e71edb6b33f822e001500dac90acf95faacea8Chris Lattner SRThreshold = 128; 54ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel else 55ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel SRThreshold = T; 56ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel } 57794fd75c67a2cdc128d67342c6d88a504d186896Devang Patel 58ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner bool runOnFunction(Function &F); 59ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 6038aec325604635380421a27e39ab06d55ed2458dChris Lattner bool performScalarRepl(Function &F); 6138aec325604635380421a27e39ab06d55ed2458dChris Lattner bool performPromotion(Function &F); 6238aec325604635380421a27e39ab06d55ed2458dChris Lattner 63a15854c9febcb60eb107048640b04abff8cc47e5Chris Lattner // getAnalysisUsage - This pass does not require any passes, but we know it 64a15854c9febcb60eb107048640b04abff8cc47e5Chris Lattner // will not alter the CFG, so say so. 65a15854c9febcb60eb107048640b04abff8cc47e5Chris Lattner virtual void getAnalysisUsage(AnalysisUsage &AU) const { 66326821ef12c911af1d785e305e81dc3c07e456a5Devang Patel AU.addRequired<DominatorTree>(); 6738aec325604635380421a27e39ab06d55ed2458dChris Lattner AU.addRequired<DominanceFrontier>(); 6838aec325604635380421a27e39ab06d55ed2458dChris Lattner AU.addRequired<TargetData>(); 69a15854c9febcb60eb107048640b04abff8cc47e5Chris Lattner AU.setPreservesCFG(); 70a15854c9febcb60eb107048640b04abff8cc47e5Chris Lattner } 71a15854c9febcb60eb107048640b04abff8cc47e5Chris Lattner 72ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner private: 7339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// AllocaInfo - When analyzing uses of an alloca instruction, this captures 7439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// information about the uses. All these fields are initialized to false 7539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// and set to true when something is learned. 7639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner struct AllocaInfo { 7739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// isUnsafe - This is set to true if the alloca cannot be SROA'd. 7839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner bool isUnsafe : 1; 7939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 8039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// needsCanon - This is set to true if there is some use of the alloca 8139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// that requires canonicalization. 8239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner bool needsCanon : 1; 8339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 8439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// isMemCpySrc - This is true if this aggregate is memcpy'd from. 8539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner bool isMemCpySrc : 1; 8639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 8733b0b8d242de8d428f11e77ea734a08b47797216Zhou Sheng /// isMemCpyDst - This is true if this aggregate is memcpy'd into. 8839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner bool isMemCpyDst : 1; 8939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 9039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo() 9139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner : isUnsafe(false), needsCanon(false), 9239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isMemCpySrc(false), isMemCpyDst(false) {} 9339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner }; 9439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 95ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel unsigned SRThreshold; 96ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel 9739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner void MarkUnsafe(AllocaInfo &I) { I.isUnsafe = true; } 9839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 99f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner int isSafeAllocaToScalarRepl(AllocationInst *AI); 10039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 10139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner void isSafeUseOfAllocation(Instruction *User, AllocationInst *AI, 10239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo &Info); 10339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner void isSafeElementUse(Value *Ptr, bool isFirstElt, AllocationInst *AI, 10439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo &Info); 10539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner void isSafeMemIntrinsicOnAllocation(MemIntrinsic *MI, AllocationInst *AI, 10639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner unsigned OpNo, AllocaInfo &Info); 10739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner void isSafeUseOfBitCastedAllocation(BitCastInst *User, AllocationInst *AI, 10839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo &Info); 10939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 110a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner void DoScalarReplacement(AllocationInst *AI, 111a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner std::vector<AllocationInst*> &WorkList); 112f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner void CanonicalizeAllocaUsers(AllocationInst *AI); 113ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner AllocaInst *AddNewAlloca(Function &F, const Type *Ty, AllocationInst *Base); 114a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1158bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner void RewriteBitCastUserOfAlloca(Instruction *BCInst, AllocationInst *AI, 116372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner SmallVector<AllocaInst*, 32> &NewElts); 117372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 118a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *CanConvertToScalar(Value *V, bool &IsNotTrivial); 119a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner void ConvertToScalar(AllocationInst *AI, const Type *Ty); 120a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner void ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI, unsigned Offset); 121800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *ConvertUsesOfLoadToScalar(LoadInst *LI, AllocaInst *NewAI, 122800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned Offset); 123800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *ConvertUsesOfStoreToScalar(StoreInst *SI, AllocaInst *NewAI, 124800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned Offset); 12579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner static Instruction *isOnlyCopiedFromConstantGlobal(AllocationInst *AI); 126ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner }; 127ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner} 128ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 129844731a7f1909f55935e3514c9e713a62d67662eDan Gohmanchar SROA::ID = 0; 130844731a7f1909f55935e3514c9e713a62d67662eDan Gohmanstatic RegisterPass<SROA> X("scalarrepl", "Scalar Replacement of Aggregates"); 131844731a7f1909f55935e3514c9e713a62d67662eDan Gohman 132d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke// Public interface to the ScalarReplAggregates pass 133ff366850aa9956e167e78d4f5b57aae10d8c5779Devang PatelFunctionPass *llvm::createScalarReplAggregatesPass(signed int Threshold) { 134ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel return new SROA(Threshold); 135ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel} 136ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 137ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 138ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattnerbool SROA::runOnFunction(Function &F) { 139fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner bool Changed = performPromotion(F); 140fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner while (1) { 141fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner bool LocalChange = performScalarRepl(F); 142fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner if (!LocalChange) break; // No need to repromote if no scalarrepl 143fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner Changed = true; 144fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner LocalChange = performPromotion(F); 145fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner if (!LocalChange) break; // No need to re-scalarrepl if no promotion 146fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner } 14738aec325604635380421a27e39ab06d55ed2458dChris Lattner 14838aec325604635380421a27e39ab06d55ed2458dChris Lattner return Changed; 14938aec325604635380421a27e39ab06d55ed2458dChris Lattner} 15038aec325604635380421a27e39ab06d55ed2458dChris Lattner 15138aec325604635380421a27e39ab06d55ed2458dChris Lattner 15238aec325604635380421a27e39ab06d55ed2458dChris Lattnerbool SROA::performPromotion(Function &F) { 15338aec325604635380421a27e39ab06d55ed2458dChris Lattner std::vector<AllocaInst*> Allocas; 154326821ef12c911af1d785e305e81dc3c07e456a5Devang Patel DominatorTree &DT = getAnalysis<DominatorTree>(); 15543f820d1f7638656be2158efac7dd8f5b08b8b77Chris Lattner DominanceFrontier &DF = getAnalysis<DominanceFrontier>(); 15638aec325604635380421a27e39ab06d55ed2458dChris Lattner 15702a3be020a6b4eedb4b489959997d23a22cdf22eChris Lattner BasicBlock &BB = F.getEntryBlock(); // Get the entry node for the function 15838aec325604635380421a27e39ab06d55ed2458dChris Lattner 159fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner bool Changed = false; 160fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 16138aec325604635380421a27e39ab06d55ed2458dChris Lattner while (1) { 16238aec325604635380421a27e39ab06d55ed2458dChris Lattner Allocas.clear(); 16338aec325604635380421a27e39ab06d55ed2458dChris Lattner 16438aec325604635380421a27e39ab06d55ed2458dChris Lattner // Find allocas that are safe to promote, by looking at all instructions in 16538aec325604635380421a27e39ab06d55ed2458dChris Lattner // the entry node 16638aec325604635380421a27e39ab06d55ed2458dChris Lattner for (BasicBlock::iterator I = BB.begin(), E = --BB.end(); I != E; ++I) 16738aec325604635380421a27e39ab06d55ed2458dChris Lattner if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) // Is it an alloca? 16841968df51e11f581eb19c8f68a8cb2f4e8acc1c5Devang Patel if (isAllocaPromotable(AI)) 16938aec325604635380421a27e39ab06d55ed2458dChris Lattner Allocas.push_back(AI); 17038aec325604635380421a27e39ab06d55ed2458dChris Lattner 17138aec325604635380421a27e39ab06d55ed2458dChris Lattner if (Allocas.empty()) break; 17238aec325604635380421a27e39ab06d55ed2458dChris Lattner 173326821ef12c911af1d785e305e81dc3c07e456a5Devang Patel PromoteMemToReg(Allocas, DT, DF); 17438aec325604635380421a27e39ab06d55ed2458dChris Lattner NumPromoted += Allocas.size(); 17538aec325604635380421a27e39ab06d55ed2458dChris Lattner Changed = true; 17638aec325604635380421a27e39ab06d55ed2458dChris Lattner } 17738aec325604635380421a27e39ab06d55ed2458dChris Lattner 17838aec325604635380421a27e39ab06d55ed2458dChris Lattner return Changed; 17938aec325604635380421a27e39ab06d55ed2458dChris Lattner} 18038aec325604635380421a27e39ab06d55ed2458dChris Lattner 181963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner/// getNumSAElements - Return the number of elements in the specific struct or 182963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner/// array. 183963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattnerstatic uint64_t getNumSAElements(const Type *T) { 184963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner if (const StructType *ST = dyn_cast<StructType>(T)) 185963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner return ST->getNumElements(); 186963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner return cast<ArrayType>(T)->getNumElements(); 187963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner} 188963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner 18938aec325604635380421a27e39ab06d55ed2458dChris Lattner// performScalarRepl - This algorithm is a simple worklist driven algorithm, 19038aec325604635380421a27e39ab06d55ed2458dChris Lattner// which runs on all of the malloc/alloca instructions in the function, removing 19138aec325604635380421a27e39ab06d55ed2458dChris Lattner// them if they are only used by getelementptr instructions. 19238aec325604635380421a27e39ab06d55ed2458dChris Lattner// 19338aec325604635380421a27e39ab06d55ed2458dChris Lattnerbool SROA::performScalarRepl(Function &F) { 194ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner std::vector<AllocationInst*> WorkList; 195ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 196ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner // Scan the entry basic block, adding any alloca's and mallocs to the worklist 19702a3be020a6b4eedb4b489959997d23a22cdf22eChris Lattner BasicBlock &BB = F.getEntryBlock(); 198ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E; ++I) 199ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner if (AllocationInst *A = dyn_cast<AllocationInst>(I)) 200ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner WorkList.push_back(A); 201ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 2027139406707eb3869183fd6a3329fe4a77d309692Chris Lattner const TargetData &TD = getAnalysis<TargetData>(); 2037139406707eb3869183fd6a3329fe4a77d309692Chris Lattner 204ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner // Process the worklist 205ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner bool Changed = false; 206ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner while (!WorkList.empty()) { 207ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner AllocationInst *AI = WorkList.back(); 208ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner WorkList.pop_back(); 209a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 210add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner // Handle dead allocas trivially. These can be formed by SROA'ing arrays 211add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner // with unused elements. 212add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner if (AI->use_empty()) { 213add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner AI->eraseFromParent(); 214add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner continue; 215add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner } 216add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner 217a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // If we can turn this aggregate value (potentially with casts) into a 218a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // simple scalar value that can be mem2reg'd into a register value. 219a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner bool IsNotTrivial = false; 220a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (const Type *ActualType = CanConvertToScalar(AI, IsNotTrivial)) 221df4f226cdcbe853984ddda10aa0d53590d35b97eChris Lattner if (IsNotTrivial && ActualType != Type::VoidTy) { 222a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner ConvertToScalar(AI, ActualType); 223a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner Changed = true; 224a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner continue; 225a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 226ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 22779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // Check to see if we can perform the core SROA transformation. We cannot 22879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // transform the allocation instruction if it is an array allocation 22979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // (allocations OF arrays are ok though), and an allocation of a scalar 23079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // value cannot be decomposed at all. 231a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner if (!AI->isArrayAllocation() && 232a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner (isa<StructType>(AI->getAllocatedType()) || 2337139406707eb3869183fd6a3329fe4a77d309692Chris Lattner isa<ArrayType>(AI->getAllocatedType())) && 2347139406707eb3869183fd6a3329fe4a77d309692Chris Lattner AI->getAllocatedType()->isSized() && 235963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner // Do not promote any struct whose size is larger than "128" bytes. 236963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner TD.getABITypeSize(AI->getAllocatedType()) < SRThreshold && 237963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner // Do not promote any struct into more than "32" separate vars. 238963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner getNumSAElements(AI->getAllocatedType()) < SRThreshold/4) { 239a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Check that all of the users of the allocation are capable of being 240a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // transformed. 241a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner switch (isSafeAllocaToScalarRepl(AI)) { 242a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner default: assert(0 && "Unexpected value!"); 243a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner case 0: // Not safe to scalar replace. 244a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner break; 245a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner case 1: // Safe, but requires cleanup/canonicalizations first 246a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner CanonicalizeAllocaUsers(AI); 247a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // FALL THROUGH. 248a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner case 3: // Safe to scalar replace. 249a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner DoScalarReplacement(AI, WorkList); 250a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner Changed = true; 251a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner continue; 252a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 253f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner } 25479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 25579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // Check to see if this allocation is only modified by a memcpy/memmove from 25679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // a constant global. If this is the case, we can change all users to use 25779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // the constant global instead. This is commonly produced by the CFE by 25879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // constructs like "void foo() { int A[] = {1,2,3,4,5,6,7,8,9...}; }" if 'A' 25979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // is only subsequently read. 26079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (Instruction *TheCopy = isOnlyCopiedFromConstantGlobal(AI)) { 26179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner DOUT << "Found alloca equal to global: " << *AI; 26279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner DOUT << " memcpy = " << *TheCopy; 26379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner Constant *TheSrc = cast<Constant>(TheCopy->getOperand(2)); 26479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner AI->replaceAllUsesWith(ConstantExpr::getBitCast(TheSrc, AI->getType())); 26579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner TheCopy->eraseFromParent(); // Don't mutate the global. 26679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner AI->eraseFromParent(); 26779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner ++NumGlobals; 26879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner Changed = true; 26979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner continue; 27079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner } 271a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner 272a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Otherwise, couldn't process this. 273a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 274ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 275a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner return Changed; 276a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner} 277fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 278a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner/// DoScalarReplacement - This alloca satisfied the isSafeAllocaToScalarRepl 279a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner/// predicate, do SROA now. 280a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattnervoid SROA::DoScalarReplacement(AllocationInst *AI, 281a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner std::vector<AllocationInst*> &WorkList) { 28279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner DOUT << "Found inst to SROA: " << *AI; 283a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner SmallVector<AllocaInst*, 32> ElementAllocas; 284a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner if (const StructType *ST = dyn_cast<StructType>(AI->getAllocatedType())) { 285a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner ElementAllocas.reserve(ST->getNumContainedTypes()); 286a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner for (unsigned i = 0, e = ST->getNumContainedTypes(); i != e; ++i) { 287a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AllocaInst *NA = new AllocaInst(ST->getContainedType(i), 0, 288a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AI->getAlignment(), 289a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AI->getName() + "." + utostr(i), AI); 290a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner ElementAllocas.push_back(NA); 291a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner WorkList.push_back(NA); // Add to worklist for recursive processing 292a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 293a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } else { 294a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner const ArrayType *AT = cast<ArrayType>(AI->getAllocatedType()); 295a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner ElementAllocas.reserve(AT->getNumElements()); 296a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner const Type *ElTy = AT->getElementType(); 297a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner for (unsigned i = 0, e = AT->getNumElements(); i != e; ++i) { 298a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AllocaInst *NA = new AllocaInst(ElTy, 0, AI->getAlignment(), 299a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AI->getName() + "." + utostr(i), AI); 300a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner ElementAllocas.push_back(NA); 301a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner WorkList.push_back(NA); // Add to worklist for recursive processing 302ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner } 303a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 304fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 305a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Now that we have created the alloca instructions that we want to use, 306a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // expand the getelementptr instructions to use them. 307a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // 308a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner while (!AI->use_empty()) { 309a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner Instruction *User = cast<Instruction>(AI->use_back()); 310a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner if (BitCastInst *BCInst = dyn_cast<BitCastInst>(User)) { 311a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner RewriteBitCastUserOfAlloca(BCInst, AI, ElementAllocas); 312a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner BCInst->eraseFromParent(); 313a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner continue; 314a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 315a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner 3162a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // Replace: 3172a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // %res = load { i32, i32 }* %alloc 3182a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // with: 3192a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // %load.0 = load i32* %alloc.0 3202a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // %insert.0 insertvalue { i32, i32 } zeroinitializer, i32 %load.0, 0 3212a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // %load.1 = load i32* %alloc.1 3222a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // %insert = insertvalue { i32, i32 } %insert.0, i32 %load.1, 1 32302518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman // (Also works for arrays instead of structs) 32402518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman if (LoadInst *LI = dyn_cast<LoadInst>(User)) { 32502518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman Value *Insert = UndefValue::get(LI->getType()); 32602518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman for (unsigned i = 0, e = ElementAllocas.size(); i != e; ++i) { 32702518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman Value *Load = new LoadInst(ElementAllocas[i], "load", LI); 32802518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman Insert = InsertValueInst::Create(Insert, Load, i, "insert", LI); 32902518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman } 33002518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman LI->replaceAllUsesWith(Insert); 33102518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman LI->eraseFromParent(); 33202518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman continue; 33302518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman } 33402518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman 3352a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // Replace: 3362a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // store { i32, i32 } %val, { i32, i32 }* %alloc 3372a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // with: 3382a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // %val.0 = extractvalue { i32, i32 } %val, 0 3392a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // store i32 %val.0, i32* %alloc.0 3402a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // %val.1 = extractvalue { i32, i32 } %val, 1 3412a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // store i32 %val.1, i32* %alloc.1 34202518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman // (Also works for arrays instead of structs) 34302518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman if (StoreInst *SI = dyn_cast<StoreInst>(User)) { 34402518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman Value *Val = SI->getOperand(0); 34502518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman for (unsigned i = 0, e = ElementAllocas.size(); i != e; ++i) { 34602518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman Value *Extract = ExtractValueInst::Create(Val, i, Val->getName(), SI); 34702518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman new StoreInst(Extract, ElementAllocas[i], SI); 34802518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman } 34902518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman SI->eraseFromParent(); 35002518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman continue; 35102518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman } 35202518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman 353a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner GetElementPtrInst *GEPI = cast<GetElementPtrInst>(User); 354a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // We now know that the GEP is of the form: GEP <ptr>, 0, <cst> 355a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner unsigned Idx = 356a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner (unsigned)cast<ConstantInt>(GEPI->getOperand(2))->getZExtValue(); 357a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner 358a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner assert(Idx < ElementAllocas.size() && "Index out of range?"); 359a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AllocaInst *AllocaToUse = ElementAllocas[Idx]; 360a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner 361a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner Value *RepValue; 362a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner if (GEPI->getNumOperands() == 3) { 363a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Do not insert a new getelementptr instruction with zero indices, only 364a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // to have it optimized out later. 365a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner RepValue = AllocaToUse; 366a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } else { 367a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // We are indexing deeply into the structure, so we still need a 368a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // getelement ptr instruction to finish the indexing. This may be 369a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // expanded itself once the worklist is rerun. 370a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // 371a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner SmallVector<Value*, 8> NewArgs; 372a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner NewArgs.push_back(Constant::getNullValue(Type::Int32Ty)); 373a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner NewArgs.append(GEPI->op_begin()+3, GEPI->op_end()); 374051a950000e21935165db56695e35bade668193bGabor Greif RepValue = GetElementPtrInst::Create(AllocaToUse, NewArgs.begin(), 375051a950000e21935165db56695e35bade668193bGabor Greif NewArgs.end(), "", GEPI); 376a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner RepValue->takeName(GEPI); 377a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 378a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner 379a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // If this GEP is to the start of the aggregate, check for memcpys. 380a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner if (Idx == 0) { 381a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner bool IsStartOfAggregateGEP = true; 382a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner for (unsigned i = 3, e = GEPI->getNumOperands(); i != e; ++i) { 383a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner if (!isa<ConstantInt>(GEPI->getOperand(i))) { 384a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner IsStartOfAggregateGEP = false; 385a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner break; 386a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 387a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner if (!cast<ConstantInt>(GEPI->getOperand(i))->isZero()) { 388a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner IsStartOfAggregateGEP = false; 389a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner break; 3908bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner } 3918bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner } 3928bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 393a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner if (IsStartOfAggregateGEP) 394a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner RewriteBitCastUserOfAlloca(GEPI, AI, ElementAllocas); 395ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner } 396a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner 397ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 398a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Move all of the users over to the new GEP. 399a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner GEPI->replaceAllUsesWith(RepValue); 400a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Delete the old GEP 401a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner GEPI->eraseFromParent(); 402ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner } 403ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 404a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Finally, delete the Alloca instruction 405a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AI->eraseFromParent(); 406a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner NumReplaced++; 407ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner} 4085e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner 4095e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner 410f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// isSafeElementUse - Check to see if this use is an allowed use for a 4118bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// getelementptr instruction of an array aggregate allocation. isFirstElt 4128bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// indicates whether Ptr is known to the start of the aggregate. 413f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// 41439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattnervoid SROA::isSafeElementUse(Value *Ptr, bool isFirstElt, AllocationInst *AI, 41539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo &Info) { 416f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner for (Value::use_iterator I = Ptr->use_begin(), E = Ptr->use_end(); 417f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner I != E; ++I) { 418f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner Instruction *User = cast<Instruction>(*I); 419f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner switch (User->getOpcode()) { 420f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner case Instruction::Load: break; 421f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner case Instruction::Store: 422f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner // Store is ok if storing INTO the pointer, not storing the pointer 42339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (User->getOperand(0) == Ptr) return MarkUnsafe(Info); 424f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner break; 425f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner case Instruction::GetElementPtr: { 426f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner GetElementPtrInst *GEP = cast<GetElementPtrInst>(User); 4278bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner bool AreAllZeroIndices = isFirstElt; 428f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner if (GEP->getNumOperands() > 1) { 4298bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner if (!isa<ConstantInt>(GEP->getOperand(1)) || 4308bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner !cast<ConstantInt>(GEP->getOperand(1))->isZero()) 43139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // Using pointer arithmetic to navigate the array. 43239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 4338bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 4348bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner if (AreAllZeroIndices) { 4358bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner for (unsigned i = 2, e = GEP->getNumOperands(); i != e; ++i) { 4368bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner if (!isa<ConstantInt>(GEP->getOperand(i)) || 4378bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner !cast<ConstantInt>(GEP->getOperand(i))->isZero()) { 4388bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner AreAllZeroIndices = false; 4398bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner break; 4408bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner } 4418bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner } 4428bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner } 443f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner } 44439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isSafeElementUse(GEP, AreAllZeroIndices, AI, Info); 44539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (Info.isUnsafe) return; 446f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner break; 447f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner } 4488bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner case Instruction::BitCast: 44939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (isFirstElt) { 45039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isSafeUseOfBitCastedAllocation(cast<BitCastInst>(User), AI, Info); 45139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (Info.isUnsafe) return; 4528bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner break; 45339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 4548bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner DOUT << " Transformation preventing inst: " << *User; 45539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 4568bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner case Instruction::Call: 4578bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(User)) { 45839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (isFirstElt) { 45939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isSafeMemIntrinsicOnAllocation(MI, AI, I.getOperandNo(), Info); 46039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (Info.isUnsafe) return; 4618bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner break; 46239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 4638bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner } 4648bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner DOUT << " Transformation preventing inst: " << *User; 46539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 466f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner default: 467b7427031372337e6d67f9573ec6c722ab5ea913eBill Wendling DOUT << " Transformation preventing inst: " << *User; 46839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 469f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner } 470f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner } 47139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return; // All users look ok :) 472f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner} 473f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner 474d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner/// AllUsersAreLoads - Return true if all users of this value are loads. 475d878ecd904e4469344a2274f9784422c2c68b81cChris Lattnerstatic bool AllUsersAreLoads(Value *Ptr) { 476d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner for (Value::use_iterator I = Ptr->use_begin(), E = Ptr->use_end(); 477d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner I != E; ++I) 478d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner if (cast<Instruction>(*I)->getOpcode() != Instruction::Load) 479d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner return false; 480fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman return true; 481d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner} 482d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner 4835e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner/// isSafeUseOfAllocation - Check to see if this user is an allowed use for an 4845e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner/// aggregate allocation. 4855e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner/// 48639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattnervoid SROA::isSafeUseOfAllocation(Instruction *User, AllocationInst *AI, 48739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo &Info) { 488372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (BitCastInst *C = dyn_cast<BitCastInst>(User)) 48939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return isSafeUseOfBitCastedAllocation(C, AI, Info); 49039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 49102518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman if (isa<LoadInst>(User)) 49202518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman return; // Loads (returning a first class aggregrate) are always rewritable 49302518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman 49402518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman if (isa<StoreInst>(User) && User->getOperand(0) != AI) 49502518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman return; // Store is ok if storing INTO the pointer, not storing the pointer 49602518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman 49739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(User); 49839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (GEPI == 0) 49939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 500546fc40d69ce4051b48112aafedd1e41f4a13195Chris Lattner 501be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner gep_type_iterator I = gep_type_begin(GEPI), E = gep_type_end(GEPI); 502be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner 50325de486263abc1882498a8701e3eb29ee0804c4eChris Lattner // The GEP is not safe to transform if not of the form "GEP <ptr>, 0, <cst>". 504be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner if (I == E || 50539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner I.getOperand() != Constant::getNullValue(I.getOperand()->getType())) { 50639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 50739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 508be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner 509be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner ++I; 51039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (I == E) return MarkUnsafe(Info); // ran out of GEP indices?? 511546fc40d69ce4051b48112aafedd1e41f4a13195Chris Lattner 5128bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner bool IsAllZeroIndices = true; 5138bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 51488e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner // If the first index is a non-constant index into an array, see if we can 51588e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner // handle it as a special case. 516be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner if (const ArrayType *AT = dyn_cast<ArrayType>(*I)) { 51788e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner if (!isa<ConstantInt>(I.getOperand())) { 5188bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner IsAllZeroIndices = 0; 51988e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner uint64_t NumElements = AT->getNumElements(); 5208bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 521d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // If this is an array index and the index is not constant, we cannot 522d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // promote... that is unless the array has exactly one or two elements in 523d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // it, in which case we CAN promote it, but we have to canonicalize this 524d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // out if this is the only problem. 52525de486263abc1882498a8701e3eb29ee0804c4eChris Lattner if ((NumElements == 1 || NumElements == 2) && 52639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllUsersAreLoads(GEPI)) { 52739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner Info.needsCanon = true; 52839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return; // Canonicalization required! 52939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 53039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 531d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } 5325e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner } 53388e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner 53488e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner 53588e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner // Walk through the GEP type indices, checking the types that this indexes 53688e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner // into. 53788e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner for (; I != E; ++I) { 53888e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner // Ignore struct elements, no extra checking needed for these. 53988e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner if (isa<StructType>(*I)) 54088e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner continue; 54188e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner 54288e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner // Don't SROA pointers into vectors. 54388e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner if (isa<VectorType>(*I)) 54488e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner return MarkUnsafe(Info); 54588e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner 54688e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner // Otherwise, we must have an index into an array type. Verify that this is 54788e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner // an in-range constant integer. Specifically, consider A[0][i]. We 54888e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner // cannot know that the user isn't doing invalid things like allowing i to 54988e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner // index an out-of-range subscript that accesses A[1]. Because of this, we 55088e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner // have to reject SROA of any accesses into structs where any of the 55188e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner // components are variables. 55288e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner ConstantInt *IdxVal = dyn_cast<ConstantInt>(I.getOperand()); 55388e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner if (!IdxVal) return MarkUnsafe(Info); 55488e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner if (IdxVal->getZExtValue() >= cast<ArrayType>(*I)->getNumElements()) 55588e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner return MarkUnsafe(Info); 55688e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner 55788e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner IsAllZeroIndices &= IdxVal->isZero(); 55888e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner } 55988e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner 560be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner // If there are any non-simple uses of this getelementptr, make sure to reject 561be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner // them. 56239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return isSafeElementUse(GEPI, IsAllZeroIndices, AI, Info); 5638bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner} 5648bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 5658bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// isSafeMemIntrinsicOnAllocation - Return true if the specified memory 5668bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// intrinsic can be promoted by SROA. At this point, we know that the operand 5678bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// of the memintrinsic is a pointer to the beginning of the allocation. 56839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattnervoid SROA::isSafeMemIntrinsicOnAllocation(MemIntrinsic *MI, AllocationInst *AI, 56939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner unsigned OpNo, AllocaInfo &Info) { 5708bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner // If not constant length, give up. 5718bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner ConstantInt *Length = dyn_cast<ConstantInt>(MI->getLength()); 57239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (!Length) return MarkUnsafe(Info); 5738bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 5748bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner // If not the whole aggregate, give up. 5758bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner const TargetData &TD = getAnalysis<TargetData>(); 5763cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands if (Length->getZExtValue() != 5773cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands TD.getABITypeSize(AI->getType()->getElementType())) 57839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 5798bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 5808bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner // We only know about memcpy/memset/memmove. 5818bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner if (!isa<MemCpyInst>(MI) && !isa<MemSetInst>(MI) && !isa<MemMoveInst>(MI)) 58239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 58339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 58439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // Otherwise, we can transform it. Determine whether this is a memcpy/set 58539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // into or out of the aggregate. 58639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (OpNo == 1) 58739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner Info.isMemCpyDst = true; 58839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner else { 58939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner assert(OpNo == 2); 59039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner Info.isMemCpySrc = true; 59139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 5925e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner} 5935e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner 594372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner/// isSafeUseOfBitCastedAllocation - Return true if all users of this bitcast 595372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner/// are 59639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattnervoid SROA::isSafeUseOfBitCastedAllocation(BitCastInst *BC, AllocationInst *AI, 59739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo &Info) { 598372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner for (Value::use_iterator UI = BC->use_begin(), E = BC->use_end(); 599372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner UI != E; ++UI) { 600372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (BitCastInst *BCU = dyn_cast<BitCastInst>(UI)) { 60139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isSafeUseOfBitCastedAllocation(BCU, AI, Info); 602372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } else if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(UI)) { 60339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isSafeMemIntrinsicOnAllocation(MI, AI, UI.getOperandNo(), Info); 604372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } else { 60539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 606372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 60739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (Info.isUnsafe) return; 608372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 609372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner} 610372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 6118bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// RewriteBitCastUserOfAlloca - BCInst (transitively) bitcasts AI, or indexes 6128bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// to its first element. Transform users of the cast to use the new values 6138bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// instead. 6148bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattnervoid SROA::RewriteBitCastUserOfAlloca(Instruction *BCInst, AllocationInst *AI, 615372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner SmallVector<AllocaInst*, 32> &NewElts) { 616372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner Constant *Zero = Constant::getNullValue(Type::Int32Ty); 617372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner const TargetData &TD = getAnalysis<TargetData>(); 6188bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 6198bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner Value::use_iterator UI = BCInst->use_begin(), UE = BCInst->use_end(); 6208bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner while (UI != UE) { 6218bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner if (BitCastInst *BCU = dyn_cast<BitCastInst>(*UI)) { 622372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner RewriteBitCastUserOfAlloca(BCU, AI, NewElts); 6238bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner ++UI; 6248bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner BCU->eraseFromParent(); 625372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner continue; 626372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 627372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 628372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // Otherwise, must be memcpy/memmove/memset of the entire aggregate. Split 629372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // into one per element. 6308bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner MemIntrinsic *MI = dyn_cast<MemIntrinsic>(*UI); 6318bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 6328bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner // If it's not a mem intrinsic, it must be some other user of a gep of the 6338bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner // first pointer. Just leave these alone. 6348bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner if (!MI) { 6358bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner ++UI; 6368bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner continue; 6378bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner } 638372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 639372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // If this is a memcpy/memmove, construct the other pointer as the 640372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // appropriate type. 641372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner Value *OtherPtr = 0; 642372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (MemCpyInst *MCI = dyn_cast<MemCpyInst>(MI)) { 643372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (BCInst == MCI->getRawDest()) 644372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner OtherPtr = MCI->getRawSource(); 645372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner else { 646372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner assert(BCInst == MCI->getRawSource()); 647372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner OtherPtr = MCI->getRawDest(); 648372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 649372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } else if (MemMoveInst *MMI = dyn_cast<MemMoveInst>(MI)) { 650372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (BCInst == MMI->getRawDest()) 651372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner OtherPtr = MMI->getRawSource(); 652372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner else { 653372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner assert(BCInst == MMI->getRawSource()); 654372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner OtherPtr = MMI->getRawDest(); 655372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 656372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 657372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 658372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // If there is an other pointer, we want to convert it to the same pointer 659372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // type as AI has, so we can GEP through it. 660372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (OtherPtr) { 661372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // It is likely that OtherPtr is a bitcast, if so, remove it. 662372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (BitCastInst *BC = dyn_cast<BitCastInst>(OtherPtr)) 663372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner OtherPtr = BC->getOperand(0); 664372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (ConstantExpr *BCE = dyn_cast<ConstantExpr>(OtherPtr)) 665372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (BCE->getOpcode() == Instruction::BitCast) 666372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner OtherPtr = BCE->getOperand(0); 667372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 668372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // If the pointer is not the right type, insert a bitcast to the right 669372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // type. 670372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (OtherPtr->getType() != AI->getType()) 671372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner OtherPtr = new BitCastInst(OtherPtr, AI->getType(), OtherPtr->getName(), 672372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner MI); 673372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 674372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 675372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // Process each element of the aggregate. 676372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner Value *TheFn = MI->getOperand(0); 677372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner const Type *BytePtrTy = MI->getRawDest()->getType(); 678372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner bool SROADest = MI->getRawDest() == BCInst; 679372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 680372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner for (unsigned i = 0, e = NewElts.size(); i != e; ++i) { 681372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // If this is a memcpy/memmove, emit a GEP of the other element address. 682372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner Value *OtherElt = 0; 683372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (OtherPtr) { 684963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner Value *Idx[2] = { Zero, ConstantInt::get(Type::Int32Ty, i) }; 685051a950000e21935165db56695e35bade668193bGabor Greif OtherElt = GetElementPtrInst::Create(OtherPtr, Idx, Idx + 2, 686963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner OtherPtr->getNameStr()+"."+utostr(i), 687051a950000e21935165db56695e35bade668193bGabor Greif MI); 688372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 689372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 690372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner Value *EltPtr = NewElts[i]; 691c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner const Type *EltTy =cast<PointerType>(EltPtr->getType())->getElementType(); 692c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner 693c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner // If we got down to a scalar, insert a load or store as appropriate. 69431e5bdccf29f0ce6172f0f0bbb43a9a736b1ef0cDan Gohman if (EltTy->isSingleValueType()) { 695c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner if (isa<MemCpyInst>(MI) || isa<MemMoveInst>(MI)) { 696c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner Value *Elt = new LoadInst(SROADest ? OtherElt : EltPtr, "tmp", 697c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner MI); 698c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner new StoreInst(Elt, SROADest ? EltPtr : OtherElt, MI); 699c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner continue; 700c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } else { 701c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner assert(isa<MemSetInst>(MI)); 702c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner 703c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner // If the stored element is zero (common case), just store a null 704c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner // constant. 705c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner Constant *StoreVal; 706c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner if (ConstantInt *CI = dyn_cast<ConstantInt>(MI->getOperand(2))) { 707c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner if (CI->isZero()) { 708c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner StoreVal = Constant::getNullValue(EltTy); // 0.0, null, 0, <0,0> 709c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } else { 71007a96765daedf180a7102d39fe56c499878312b7Dan Gohman // If EltTy is a vector type, get the element type. 711c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner const Type *ValTy = EltTy; 712c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner if (const VectorType *VTy = dyn_cast<VectorType>(ValTy)) 713c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner ValTy = VTy->getElementType(); 7143cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 715c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner // Construct an integer with the right value. 7163cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands unsigned EltSize = TD.getTypeSizeInBits(ValTy); 7173cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands APInt OneVal(EltSize, CI->getZExtValue()); 718c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner APInt TotalVal(OneVal); 719c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner // Set each byte. 7203cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands for (unsigned i = 0; 8*i < EltSize; ++i) { 721c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner TotalVal = TotalVal.shl(8); 722c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner TotalVal |= OneVal; 723c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } 7243cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 725c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner // Convert the integer value to the appropriate type. 726c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner StoreVal = ConstantInt::get(TotalVal); 727c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner if (isa<PointerType>(ValTy)) 728c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner StoreVal = ConstantExpr::getIntToPtr(StoreVal, ValTy); 729c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner else if (ValTy->isFloatingPoint()) 730c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner StoreVal = ConstantExpr::getBitCast(StoreVal, ValTy); 731c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner assert(StoreVal->getType() == ValTy && "Type mismatch!"); 732c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner 733c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner // If the requested value was a vector constant, create it. 734c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner if (EltTy != ValTy) { 735c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner unsigned NumElts = cast<VectorType>(ValTy)->getNumElements(); 736c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner SmallVector<Constant*, 16> Elts(NumElts, StoreVal); 737c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner StoreVal = ConstantVector::get(&Elts[0], NumElts); 738c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } 739c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } 740c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner new StoreInst(StoreVal, EltPtr, MI); 741c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner continue; 742c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } 743c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner // Otherwise, if we're storing a byte variable, use a memset call for 744c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner // this element. 745c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } 746c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } 747372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 748372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // Cast the element pointer to BytePtrTy. 749372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (EltPtr->getType() != BytePtrTy) 750372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner EltPtr = new BitCastInst(EltPtr, BytePtrTy, EltPtr->getNameStr(), MI); 751c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner 752c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner // Cast the other pointer (if we have one) to BytePtrTy. 753c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner if (OtherElt && OtherElt->getType() != BytePtrTy) 754c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner OtherElt = new BitCastInst(OtherElt, BytePtrTy,OtherElt->getNameStr(), 755c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner MI); 756c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner 7573cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands unsigned EltSize = TD.getABITypeSize(EltTy); 758c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner 759372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // Finally, insert the meminst for this element. 760372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (isa<MemCpyInst>(MI) || isa<MemMoveInst>(MI)) { 761372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner Value *Ops[] = { 762372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner SROADest ? EltPtr : OtherElt, // Dest ptr 763372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner SROADest ? OtherElt : EltPtr, // Src ptr 764372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner ConstantInt::get(MI->getOperand(3)->getType(), EltSize), // Size 765372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner Zero // Align 766372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner }; 767051a950000e21935165db56695e35bade668193bGabor Greif CallInst::Create(TheFn, Ops, Ops + 4, "", MI); 768c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } else { 769c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner assert(isa<MemSetInst>(MI)); 770372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner Value *Ops[] = { 771372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner EltPtr, MI->getOperand(2), // Dest, Value, 772372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner ConstantInt::get(MI->getOperand(3)->getType(), EltSize), // Size 773372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner Zero // Align 774372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner }; 775051a950000e21935165db56695e35bade668193bGabor Greif CallInst::Create(TheFn, Ops, Ops + 4, "", MI); 776372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 777c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } 778372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 779372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // Finally, MI is now dead, as we've modified its actions to occur on all of 780372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // the elements of the aggregate. 7818bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner ++UI; 782372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner MI->eraseFromParent(); 783372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 784372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner} 785372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 7863cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands/// HasPadding - Return true if the specified type has any structure or 7873cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands/// alignment padding, false otherwise. 788a0fcc08e6542a0376917b5c76a0af3eb2650c535Duncan Sandsstatic bool HasPadding(const Type *Ty, const TargetData &TD) { 78939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (const StructType *STy = dyn_cast<StructType>(Ty)) { 79039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner const StructLayout *SL = TD.getStructLayout(STy); 79139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner unsigned PrevFieldBitOffset = 0; 79239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { 7933cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands unsigned FieldBitOffset = SL->getElementOffsetInBits(i); 7943cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 79539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // Padding in sub-elements? 796a0fcc08e6542a0376917b5c76a0af3eb2650c535Duncan Sands if (HasPadding(STy->getElementType(i), TD)) 79739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return true; 7983cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 79939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // Check to see if there is any padding between this element and the 80039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // previous one. 80139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (i) { 8023cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands unsigned PrevFieldEnd = 80339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner PrevFieldBitOffset+TD.getTypeSizeInBits(STy->getElementType(i-1)); 80439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (PrevFieldEnd < FieldBitOffset) 80539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return true; 80639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 8073cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 80839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner PrevFieldBitOffset = FieldBitOffset; 80939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 8103cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 81139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // Check for tail padding. 81239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (unsigned EltCount = STy->getNumElements()) { 81339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner unsigned PrevFieldEnd = PrevFieldBitOffset + 81439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner TD.getTypeSizeInBits(STy->getElementType(EltCount-1)); 8153cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands if (PrevFieldEnd < SL->getSizeInBits()) 81639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return true; 81739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 81839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 81939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } else if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) { 820a0fcc08e6542a0376917b5c76a0af3eb2650c535Duncan Sands return HasPadding(ATy->getElementType(), TD); 8213cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands } else if (const VectorType *VTy = dyn_cast<VectorType>(Ty)) { 822a0fcc08e6542a0376917b5c76a0af3eb2650c535Duncan Sands return HasPadding(VTy->getElementType(), TD); 82339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 824a0fcc08e6542a0376917b5c76a0af3eb2650c535Duncan Sands return TD.getTypeSizeInBits(Ty) != TD.getABITypeSizeInBits(Ty); 82539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner} 826372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 827f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// isSafeStructAllocaToScalarRepl - Check to see if the specified allocation of 828f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// an aggregate can be broken down into elements. Return 0 if not, 3 if safe, 829f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// or 1 if safe after canonicalization has been performed. 8305e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner/// 831f5990edc877c4e63503c589928a00ec6ec751830Chris Lattnerint SROA::isSafeAllocaToScalarRepl(AllocationInst *AI) { 8325e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner // Loop over the use list of the alloca. We can only transform it if all of 8335e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner // the users are safe to transform. 83439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo Info; 83539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 8365e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner for (Value::use_iterator I = AI->use_begin(), E = AI->use_end(); 837f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner I != E; ++I) { 83839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isSafeUseOfAllocation(cast<Instruction>(*I), AI, Info); 83939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (Info.isUnsafe) { 840b7427031372337e6d67f9573ec6c722ab5ea913eBill Wendling DOUT << "Cannot transform: " << *AI << " due to user: " << **I; 841f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner return 0; 8425e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner } 843f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner } 84439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 84539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // Okay, we know all the users are promotable. If the aggregate is a memcpy 84639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // source and destination, we have to be careful. In particular, the memcpy 84739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // could be moving around elements that live in structure padding of the LLVM 84839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // types, but may actually be used. In these cases, we refuse to promote the 84939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // struct. 85039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (Info.isMemCpySrc && Info.isMemCpyDst && 8513cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands HasPadding(AI->getType()->getElementType(), getAnalysis<TargetData>())) 85239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return 0; 8533cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 85439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // If we require cleanup, return 1, otherwise return 3. 85539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return Info.needsCanon ? 1 : 3; 856f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner} 857f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner 858f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// CanonicalizeAllocaUsers - If SROA reported that it can promote the specified 859f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// allocation, but only if cleaned up, perform the cleanups required. 860f5990edc877c4e63503c589928a00ec6ec751830Chris Lattnervoid SROA::CanonicalizeAllocaUsers(AllocationInst *AI) { 861d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // At this point, we know that the end result will be SROA'd and promoted, so 862d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // we can insert ugly code if required so long as sroa+mem2reg will clean it 863d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // up. 864d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner for (Value::use_iterator UI = AI->use_begin(), E = AI->use_end(); 865d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner UI != E; ) { 866a9d1a843fc74a9d877e105744e710496863f7580Chris Lattner GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(*UI++); 867a9d1a843fc74a9d877e105744e710496863f7580Chris Lattner if (!GEPI) continue; 86896326f9d312585532c95dcc31626f45f16cd5dd8Reid Spencer gep_type_iterator I = gep_type_begin(GEPI); 869d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner ++I; 870d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner 871d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner if (const ArrayType *AT = dyn_cast<ArrayType>(*I)) { 872d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner uint64_t NumElements = AT->getNumElements(); 873fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 874d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner if (!isa<ConstantInt>(I.getOperand())) { 875d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner if (NumElements == 1) { 876c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer GEPI->setOperand(2, Constant::getNullValue(Type::Int32Ty)); 877d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } else { 878d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner assert(NumElements == 2 && "Unhandled case!"); 879d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // All users of the GEP must be loads. At each use of the GEP, insert 880d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // two loads of the appropriate indexed GEP and select between them. 881e4d87aa2de6e52952dca73716386db09aad5a8fdReid Spencer Value *IsOne = new ICmpInst(ICmpInst::ICMP_NE, I.getOperand(), 882d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner Constant::getNullValue(I.getOperand()->getType()), 883e4d87aa2de6e52952dca73716386db09aad5a8fdReid Spencer "isone", GEPI); 884d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // Insert the new GEP instructions, which are properly indexed. 8851ccd185cb49d81465a2901622e58ceae046d1d83Chris Lattner SmallVector<Value*, 8> Indices(GEPI->op_begin()+1, GEPI->op_end()); 886c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer Indices[1] = Constant::getNullValue(Type::Int32Ty); 887051a950000e21935165db56695e35bade668193bGabor Greif Value *ZeroIdx = GetElementPtrInst::Create(GEPI->getOperand(0), 888051a950000e21935165db56695e35bade668193bGabor Greif Indices.begin(), 889051a950000e21935165db56695e35bade668193bGabor Greif Indices.end(), 890051a950000e21935165db56695e35bade668193bGabor Greif GEPI->getName()+".0", GEPI); 891c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer Indices[1] = ConstantInt::get(Type::Int32Ty, 1); 892051a950000e21935165db56695e35bade668193bGabor Greif Value *OneIdx = GetElementPtrInst::Create(GEPI->getOperand(0), 893051a950000e21935165db56695e35bade668193bGabor Greif Indices.begin(), 894051a950000e21935165db56695e35bade668193bGabor Greif Indices.end(), 895051a950000e21935165db56695e35bade668193bGabor Greif GEPI->getName()+".1", GEPI); 896d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // Replace all loads of the variable index GEP with loads from both 897d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // indexes and a select. 898d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner while (!GEPI->use_empty()) { 899d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner LoadInst *LI = cast<LoadInst>(GEPI->use_back()); 900d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner Value *Zero = new LoadInst(ZeroIdx, LI->getName()+".0", LI); 901d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner Value *One = new LoadInst(OneIdx , LI->getName()+".1", LI); 902051a950000e21935165db56695e35bade668193bGabor Greif Value *R = SelectInst::Create(IsOne, One, Zero, LI->getName(), LI); 903d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner LI->replaceAllUsesWith(R); 904d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner LI->eraseFromParent(); 905d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } 906d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner GEPI->eraseFromParent(); 907d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } 908d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } 909d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } 910d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } 9115e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner} 912a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 913a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// MergeInType - Add the 'In' type to the accumulated type so far. If the 914a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// types are incompatible, return true, otherwise update Accum and return 915a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// false. 916de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// 917d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// There are three cases we handle here: 918d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// 1) An effectively-integer union, where the pieces are stored into as 919de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// smaller integers (common with byte swap and other idioms). 920d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// 2) A union of vector types of the same size and potentially its elements. 921d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// Here we turn element accesses into insert/extract element operations. 922d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// 3) A union of scalar types, such as int/float or int/pointer. Here we 923d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// merge together into integers, allowing the xform to work with #1 as 924d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// well. 9255b121cc688eacf41b1b773244882d206199dc105Chris Lattnerstatic bool MergeInType(const Type *In, const Type *&Accum, 9265b121cc688eacf41b1b773244882d206199dc105Chris Lattner const TargetData &TD) { 927a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // If this is our first type, just use it. 9289d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer const VectorType *PTy; 929de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner if (Accum == Type::VoidTy || In == Accum) { 930a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner Accum = In; 931d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner } else if (In == Type::VoidTy) { 932d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // Noop. 93342a75517250017a52afb03a0ade03cbd49559fe5Chris Lattner } else if (In->isInteger() && Accum->isInteger()) { // integer union. 934a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // Otherwise pick whichever type is larger. 935a54b7cbd452b3adb2f51346140d996b29c2cdb30Reid Spencer if (cast<IntegerType>(In)->getBitWidth() > 936a54b7cbd452b3adb2f51346140d996b29c2cdb30Reid Spencer cast<IntegerType>(Accum)->getBitWidth()) 937a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner Accum = In; 9385b121cc688eacf41b1b773244882d206199dc105Chris Lattner } else if (isa<PointerType>(In) && isa<PointerType>(Accum)) { 939c836333c3b0a18c398436ae00667a8fb5e476129Chris Lattner // Pointer unions just stay as one of the pointers. 9409d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer } else if (isa<VectorType>(In) || isa<VectorType>(Accum)) { 9419d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer if ((PTy = dyn_cast<VectorType>(Accum)) && 942d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner PTy->getElementType() == In) { 943d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // Accum is a vector, and we are accessing an element: ok. 9449d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer } else if ((PTy = dyn_cast<VectorType>(In)) && 945d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner PTy->getElementType() == Accum) { 946d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // In is a vector, and accum is an element: ok, remember In. 947d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner Accum = In; 9489d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer } else if ((PTy = dyn_cast<VectorType>(In)) && isa<VectorType>(Accum) && 9499d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer PTy->getBitWidth() == cast<VectorType>(Accum)->getBitWidth()) { 950d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // Two vectors of the same size: keep Accum. 951d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner } else { 952d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // Cannot insert an short into a <4 x int> or handle 953d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // <2 x int> -> <4 x int> 954d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner return true; 955d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner } 95621c362d3240d0ba9ff98b7f36e54f25936d1a201Chris Lattner } else { 957d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // Pointer/FP/Integer unions merge together as integers. 958d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner switch (Accum->getTypeID()) { 959d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner case Type::PointerTyID: Accum = TD.getIntPtrType(); break; 960c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer case Type::FloatTyID: Accum = Type::Int32Ty; break; 961c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer case Type::DoubleTyID: Accum = Type::Int64Ty; break; 962ef0ab932ef3b07016ffb827cd529d4787d7ed12eDale Johannesen case Type::X86_FP80TyID: return true; 963ef0ab932ef3b07016ffb827cd529d4787d7ed12eDale Johannesen case Type::FP128TyID: return true; 964ef0ab932ef3b07016ffb827cd529d4787d7ed12eDale Johannesen case Type::PPC_FP128TyID: return true; 965d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner default: 96642a75517250017a52afb03a0ade03cbd49559fe5Chris Lattner assert(Accum->isInteger() && "Unknown FP type!"); 967d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner break; 968d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner } 969d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner 970d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner switch (In->getTypeID()) { 971d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner case Type::PointerTyID: In = TD.getIntPtrType(); break; 972c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer case Type::FloatTyID: In = Type::Int32Ty; break; 973c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer case Type::DoubleTyID: In = Type::Int64Ty; break; 974ef0ab932ef3b07016ffb827cd529d4787d7ed12eDale Johannesen case Type::X86_FP80TyID: return true; 975ef0ab932ef3b07016ffb827cd529d4787d7ed12eDale Johannesen case Type::FP128TyID: return true; 976ef0ab932ef3b07016ffb827cd529d4787d7ed12eDale Johannesen case Type::PPC_FP128TyID: return true; 977d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner default: 97842a75517250017a52afb03a0ade03cbd49559fe5Chris Lattner assert(In->isInteger() && "Unknown FP type!"); 979d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner break; 980d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner } 981d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner return MergeInType(In, Accum, TD); 982a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 983a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return false; 984a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner} 985a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 9863cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands/// getUIntAtLeastAsBigAs - Return an unsigned integer type that is at least 987a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// as big as the specified type. If there is no suitable type, this returns 988a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// null. 9893cb3650a278e37aa6378127c51e407d2823139b4Duncan Sandsconst Type *getUIntAtLeastAsBigAs(unsigned NumBits) { 990a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (NumBits > 64) return 0; 991c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer if (NumBits > 32) return Type::Int64Ty; 992c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer if (NumBits > 16) return Type::Int32Ty; 993c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer if (NumBits > 8) return Type::Int16Ty; 994c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer return Type::Int8Ty; 995a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner} 996a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 997a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// CanConvertToScalar - V is a pointer. If we can convert the pointee to a 998a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// single scalar integer type, return that type. Further, if the use is not 999a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// a completely trivial use that mem2reg could promote, set IsNotTrivial. If 1000a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// there are no uses of this pointer, return Type::VoidTy to differentiate from 1001a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// failure. 1002a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// 1003a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattnerconst Type *SROA::CanConvertToScalar(Value *V, bool &IsNotTrivial) { 1004a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *UsedType = Type::VoidTy; // No uses, no forced type. 1005a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const TargetData &TD = getAnalysis<TargetData>(); 1006a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const PointerType *PTy = cast<PointerType>(V->getType()); 1007a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1008a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI!=E; ++UI) { 1009a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner Instruction *User = cast<Instruction>(*UI); 1010a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1011a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(User)) { 101202518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman // FIXME: Loads of a first class aggregrate value could be converted to a 101302518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman // series of loads and insertvalues 101402518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman if (!LI->getType()->isSingleValueType()) 101502518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman return 0; 101602518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman 10175b121cc688eacf41b1b773244882d206199dc105Chris Lattner if (MergeInType(LI->getType(), UsedType, TD)) 1018a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return 0; 1019a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1020a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else if (StoreInst *SI = dyn_cast<StoreInst>(User)) { 102124d6da5fedcf39891f7d8c5b031c01324b3db545Reid Spencer // Storing the pointer, not into the value? 1022a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (SI->getOperand(0) == V) return 0; 102302518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman 102402518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman // FIXME: Stores of a first class aggregrate value could be converted to a 102502518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman // series of extractvalues and stores 102602518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman if (!SI->getOperand(0)->getType()->isSingleValueType()) 102702518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman return 0; 1028a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1029de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner // NOTE: We could handle storing of FP imms into integers here! 1030a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 10315b121cc688eacf41b1b773244882d206199dc105Chris Lattner if (MergeInType(SI->getOperand(0)->getType(), UsedType, TD)) 1032a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return 0; 1033d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner } else if (BitCastInst *CI = dyn_cast<BitCastInst>(User)) { 1034a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner IsNotTrivial = true; 1035a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *SubTy = CanConvertToScalar(CI, IsNotTrivial); 10365b121cc688eacf41b1b773244882d206199dc105Chris Lattner if (!SubTy || MergeInType(SubTy, UsedType, TD)) return 0; 1037a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(User)) { 1038a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // Check to see if this is stepping over an element: GEP Ptr, int C 1039a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (GEP->getNumOperands() == 2 && isa<ConstantInt>(GEP->getOperand(1))) { 1040b83eb6447ba155342598f0fabe1f08f5baa9164aReid Spencer unsigned Idx = cast<ConstantInt>(GEP->getOperand(1))->getZExtValue(); 10413cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands unsigned ElSize = TD.getABITypeSize(PTy->getElementType()); 1042a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner unsigned BitOffset = Idx*ElSize*8; 1043a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (BitOffset > 64 || !isPowerOf2_32(ElSize)) return 0; 1044a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1045a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner IsNotTrivial = true; 1046a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *SubElt = CanConvertToScalar(GEP, IsNotTrivial); 1047a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (SubElt == 0) return 0; 104842a75517250017a52afb03a0ade03cbd49559fe5Chris Lattner if (SubElt != Type::VoidTy && SubElt->isInteger()) { 1049a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *NewTy = 10503cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands getUIntAtLeastAsBigAs(TD.getABITypeSizeInBits(SubElt)+BitOffset); 10515b121cc688eacf41b1b773244882d206199dc105Chris Lattner if (NewTy == 0 || MergeInType(NewTy, UsedType, TD)) return 0; 1052a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner continue; 1053a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1054a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else if (GEP->getNumOperands() == 3 && 1055a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner isa<ConstantInt>(GEP->getOperand(1)) && 1056a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner isa<ConstantInt>(GEP->getOperand(2)) && 1057843f0767acd05baed952d39e77ea89b438430a4fZhou Sheng cast<ConstantInt>(GEP->getOperand(1))->isZero()) { 1058a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // We are stepping into an element, e.g. a structure or an array: 1059a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // GEP Ptr, int 0, uint C 1060a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *AggTy = PTy->getElementType(); 1061b83eb6447ba155342598f0fabe1f08f5baa9164aReid Spencer unsigned Idx = cast<ConstantInt>(GEP->getOperand(2))->getZExtValue(); 1062a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1063a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (const ArrayType *ATy = dyn_cast<ArrayType>(AggTy)) { 1064a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (Idx >= ATy->getNumElements()) return 0; // Out of range. 1065ac9dcb94dde5f166ee29372385c0e3b695227ab4Reid Spencer } else if (const VectorType *VectorTy = dyn_cast<VectorType>(AggTy)) { 106607a96765daedf180a7102d39fe56c499878312b7Dan Gohman // Getting an element of the vector. 1067ac9dcb94dde5f166ee29372385c0e3b695227ab4Reid Spencer if (Idx >= VectorTy->getNumElements()) return 0; // Out of range. 1068de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner 1069ac9dcb94dde5f166ee29372385c0e3b695227ab4Reid Spencer // Merge in the vector type. 1070ac9dcb94dde5f166ee29372385c0e3b695227ab4Reid Spencer if (MergeInType(VectorTy, UsedType, TD)) return 0; 1071de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner 1072de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner const Type *SubTy = CanConvertToScalar(GEP, IsNotTrivial); 1073de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner if (SubTy == 0) return 0; 1074de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner 10755b121cc688eacf41b1b773244882d206199dc105Chris Lattner if (SubTy != Type::VoidTy && MergeInType(SubTy, UsedType, TD)) 1076de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner return 0; 1077de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner 1078de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner // We'll need to change this to an insert/extract element operation. 1079de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner IsNotTrivial = true; 1080de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner continue; // Everything looks ok 1081de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner 1082a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else if (isa<StructType>(AggTy)) { 1083a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // Structs are always ok. 1084a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else { 1085a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return 0; 1086a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 10873cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands const Type *NTy = getUIntAtLeastAsBigAs(TD.getABITypeSizeInBits(AggTy)); 10885b121cc688eacf41b1b773244882d206199dc105Chris Lattner if (NTy == 0 || MergeInType(NTy, UsedType, TD)) return 0; 1089a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *SubTy = CanConvertToScalar(GEP, IsNotTrivial); 1090a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (SubTy == 0) return 0; 10915b121cc688eacf41b1b773244882d206199dc105Chris Lattner if (SubTy != Type::VoidTy && MergeInType(SubTy, UsedType, TD)) 1092a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return 0; 1093a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner continue; // Everything looks ok 1094a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1095a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return 0; 1096a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else { 1097a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // Cannot handle this! 1098a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return 0; 1099a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1100a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1101a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1102a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return UsedType; 1103a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner} 1104a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1105a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// ConvertToScalar - The specified alloca passes the CanConvertToScalar 1106a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// predicate and is non-trivial. Convert it to something that can be trivially 1107a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// promoted into a register by mem2reg. 1108a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattnervoid SROA::ConvertToScalar(AllocationInst *AI, const Type *ActualTy) { 1109b7427031372337e6d67f9573ec6c722ab5ea913eBill Wendling DOUT << "CONVERT TO SCALAR: " << *AI << " TYPE = " 1110b7427031372337e6d67f9573ec6c722ab5ea913eBill Wendling << *ActualTy << "\n"; 1111a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner ++NumConverted; 1112a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1113a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner BasicBlock *EntryBlock = AI->getParent(); 1114ecb7a77885b174cf4d001a9b48533b3979e7810dDan Gohman assert(EntryBlock == &EntryBlock->getParent()->getEntryBlock() && 1115a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner "Not in the entry block!"); 1116a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner EntryBlock->getInstList().remove(AI); // Take the alloca out of the program. 1117a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1118a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // Create and insert the alloca. 1119de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner AllocaInst *NewAI = new AllocaInst(ActualTy, 0, AI->getName(), 1120de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner EntryBlock->begin()); 1121a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner ConvertUsesToScalar(AI, NewAI, 0); 1122a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner delete AI; 1123a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner} 1124a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1125a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1126a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// ConvertUsesToScalar - Convert all of the users of Ptr to use the new alloca 1127de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// directly. This happens when we are converting an "integer union" to a 1128de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// single integer scalar, or when we are converting a "vector union" to a 1129de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// vector with insert/extractelement instructions. 1130de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// 1131de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// Offset is an offset from the original alloca, in bits that need to be 1132de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// shifted to the right. By the end of this, there should be no uses of Ptr. 1133a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattnervoid SROA::ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI, unsigned Offset) { 1134a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner while (!Ptr->use_empty()) { 1135a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner Instruction *User = cast<Instruction>(Ptr->use_back()); 1136a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1137a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(User)) { 1138800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *NV = ConvertUsesOfLoadToScalar(LI, NewAI, Offset); 1139a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner LI->replaceAllUsesWith(NV); 1140a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner LI->eraseFromParent(); 1141a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else if (StoreInst *SI = dyn_cast<StoreInst>(User)) { 1142a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner assert(SI->getOperand(0) != Ptr && "Consistency error!"); 1143a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1144800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *SV = ConvertUsesOfStoreToScalar(SI, NewAI, Offset); 1145a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner new StoreInst(SV, NewAI, SI); 1146a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner SI->eraseFromParent(); 1147a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1148f4b1818728fb5cb0740cf5362faf72dd66ccf3eaChris Lattner } else if (BitCastInst *CI = dyn_cast<BitCastInst>(User)) { 1149b10e0da065fc2c18b5bee9011eb249e223a23108Chris Lattner ConvertUsesToScalar(CI, NewAI, Offset); 1150a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner CI->eraseFromParent(); 1151a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(User)) { 1152a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const PointerType *AggPtrTy = 1153a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner cast<PointerType>(GEP->getOperand(0)->getType()); 1154a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const TargetData &TD = getAnalysis<TargetData>(); 11553cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands unsigned AggSizeInBits = 11563cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands TD.getABITypeSizeInBits(AggPtrTy->getElementType()); 11573cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 1158a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // Check to see if this is stepping over an element: GEP Ptr, int C 1159a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner unsigned NewOffset = Offset; 1160a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (GEP->getNumOperands() == 2) { 1161b83eb6447ba155342598f0fabe1f08f5baa9164aReid Spencer unsigned Idx = cast<ConstantInt>(GEP->getOperand(1))->getZExtValue(); 1162a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner unsigned BitOffset = Idx*AggSizeInBits; 1163a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1164f4b1818728fb5cb0740cf5362faf72dd66ccf3eaChris Lattner NewOffset += BitOffset; 1165a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else if (GEP->getNumOperands() == 3) { 1166a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // We know that operand #2 is zero. 1167b83eb6447ba155342598f0fabe1f08f5baa9164aReid Spencer unsigned Idx = cast<ConstantInt>(GEP->getOperand(2))->getZExtValue(); 1168a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *AggTy = AggPtrTy->getElementType(); 1169a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (const SequentialType *SeqTy = dyn_cast<SequentialType>(AggTy)) { 11703cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands unsigned ElSizeBits = 11713cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands TD.getABITypeSizeInBits(SeqTy->getElementType()); 1172a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1173f4b1818728fb5cb0740cf5362faf72dd66ccf3eaChris Lattner NewOffset += ElSizeBits*Idx; 1174a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else if (const StructType *STy = dyn_cast<StructType>(AggTy)) { 1175b1919e2f08ecb37140af676fd2916f8d5ed7df3dChris Lattner unsigned EltBitOffset = 11763cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands TD.getStructLayout(STy)->getElementOffsetInBits(Idx); 1177a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1178f4b1818728fb5cb0740cf5362faf72dd66ccf3eaChris Lattner NewOffset += EltBitOffset; 1179a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else { 1180a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner assert(0 && "Unsupported operation!"); 1181a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner abort(); 1182a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1183a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else { 1184a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner assert(0 && "Unsupported operation!"); 1185a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner abort(); 1186a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1187a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner ConvertUsesToScalar(GEP, NewAI, NewOffset); 1188a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner GEP->eraseFromParent(); 1189a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else { 1190a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner assert(0 && "Unsupported operation!"); 1191a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner abort(); 1192a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1193a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1194a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner} 119579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 1196800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// ConvertUsesOfLoadToScalar - Convert all of the users the specified load to 1197800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// use the new alloca directly, returning the value that should replace the 1198800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// load. This happens when we are converting an "integer union" to a 1199800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// single integer scalar, or when we are converting a "vector union" to a 1200800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// vector with insert/extractelement instructions. 1201800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// 1202800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// Offset is an offset from the original alloca, in bits that need to be 1203800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// shifted to the right. By the end of this, there should be no uses of Ptr. 1204800de31776356910eb877e71df9f32b0a6215324Chris LattnerValue *SROA::ConvertUsesOfLoadToScalar(LoadInst *LI, AllocaInst *NewAI, 1205800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned Offset) { 1206800de31776356910eb877e71df9f32b0a6215324Chris Lattner // The load is a bit extract from NewAI shifted right by Offset bits. 1207800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *NV = new LoadInst(NewAI, LI->getName(), LI); 1208800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1209800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (NV->getType() == LI->getType() && Offset == 0) { 1210800de31776356910eb877e71df9f32b0a6215324Chris Lattner // We win, no conversion needed. 1211800de31776356910eb877e71df9f32b0a6215324Chris Lattner return NV; 1212800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 12139d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner 12149d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // If the result type of the 'union' is a pointer, then this must be ptr->ptr 12159d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // cast. Anything else would result in NV being an integer. 12169d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner if (isa<PointerType>(NV->getType())) { 12179d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner assert(isa<PointerType>(LI->getType())); 12189d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner return new BitCastInst(NV, LI->getType(), LI->getName(), LI); 12199d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner } 1220800de31776356910eb877e71df9f32b0a6215324Chris Lattner 12219d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner if (const VectorType *VTy = dyn_cast<VectorType>(NV->getType())) { 1222800de31776356910eb877e71df9f32b0a6215324Chris Lattner // If the result alloca is a vector type, this is either an element 1223800de31776356910eb877e71df9f32b0a6215324Chris Lattner // access or a bitcast to another vector type. 12249d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner if (isa<VectorType>(LI->getType())) 12259d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner return new BitCastInst(NV, LI->getType(), LI->getName(), LI); 12269d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner 12279d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // Otherwise it must be an element access. 1228800de31776356910eb877e71df9f32b0a6215324Chris Lattner const TargetData &TD = getAnalysis<TargetData>(); 12299d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner unsigned Elt = 0; 12309d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner if (Offset) { 12319d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner unsigned EltSize = TD.getABITypeSizeInBits(VTy->getElementType()); 12329d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner Elt = Offset/EltSize; 12339d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner Offset -= EltSize*Elt; 1234800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 12359d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner NV = new ExtractElementInst(NV, ConstantInt::get(Type::Int32Ty, Elt), 12369d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner "tmp", LI); 1237800de31776356910eb877e71df9f32b0a6215324Chris Lattner 12389d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // If we're done, return this element. 12399d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner if (NV->getType() == LI->getType() && Offset == 0) 12409d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner return NV; 12419d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner } 12429d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner 12439d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner const IntegerType *NTy = cast<IntegerType>(NV->getType()); 12449d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner 12459d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // If this is a big-endian system and the load is narrower than the 12469d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // full alloca type, we need to do a shift to get the right bits. 12479d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner int ShAmt = 0; 12489d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner const TargetData &TD = getAnalysis<TargetData>(); 12499d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner if (TD.isBigEndian()) { 12509d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // On big-endian machines, the lowest bit is stored at the bit offset 12519d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // from the pointer given by getTypeStoreSizeInBits. This matters for 12529d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // integers with a bitwidth that is not a multiple of 8. 12539d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner ShAmt = TD.getTypeStoreSizeInBits(NTy) - 12549d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner TD.getTypeStoreSizeInBits(LI->getType()) - Offset; 12559d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner } else { 12569d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner ShAmt = Offset; 12579d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner } 12589d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner 12599d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // Note: we support negative bitwidths (with shl) which are not defined. 12609d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // We do this to support (f.e.) loads off the end of a structure where 12619d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // only some bits are used. 12629d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner if (ShAmt > 0 && (unsigned)ShAmt < NTy->getBitWidth()) 12637cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif NV = BinaryOperator::CreateLShr(NV, 12649d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner ConstantInt::get(NV->getType(),ShAmt), 12659d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner LI->getName(), LI); 12669d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner else if (ShAmt < 0 && (unsigned)-ShAmt < NTy->getBitWidth()) 12677cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif NV = BinaryOperator::CreateShl(NV, 12689d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner ConstantInt::get(NV->getType(),-ShAmt), 12699d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner LI->getName(), LI); 12709d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner 12719d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // Finally, unconditionally truncate the integer to the right width. 12729d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner unsigned LIBitWidth = TD.getTypeSizeInBits(LI->getType()); 12739d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner if (LIBitWidth < NTy->getBitWidth()) 12749d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner NV = new TruncInst(NV, IntegerType::get(LIBitWidth), 12759d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner LI->getName(), LI); 12769d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner 12779d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // If the result is an integer, this is a trunc or bitcast. 12789d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner if (isa<IntegerType>(LI->getType())) { 12799d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // Should be done. 12809d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner } else if (LI->getType()->isFloatingPoint()) { 12819d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // Just do a bitcast, we know the sizes match up. 12829d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner NV = new BitCastInst(NV, LI->getType(), LI->getName(), LI); 12839d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner } else { 12849d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // Otherwise must be a pointer. 12859d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner NV = new IntToPtrInst(NV, LI->getType(), LI->getName(), LI); 1286800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 12879d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner assert(NV->getType() == LI->getType() && "Didn't convert right?"); 1288800de31776356910eb877e71df9f32b0a6215324Chris Lattner return NV; 1289800de31776356910eb877e71df9f32b0a6215324Chris Lattner} 1290800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1291800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1292800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// ConvertUsesOfStoreToScalar - Convert the specified store to a load+store 1293800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// pair of the new alloca directly, returning the value that should be stored 1294800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// to the alloca. This happens when we are converting an "integer union" to a 1295800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// single integer scalar, or when we are converting a "vector union" to a 1296800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// vector with insert/extractelement instructions. 1297800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// 1298800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// Offset is an offset from the original alloca, in bits that need to be 1299800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// shifted to the right. By the end of this, there should be no uses of Ptr. 1300800de31776356910eb877e71df9f32b0a6215324Chris LattnerValue *SROA::ConvertUsesOfStoreToScalar(StoreInst *SI, AllocaInst *NewAI, 1301800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned Offset) { 1302800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1303800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Convert the stored type to the actual type, shift it left to insert 1304800de31776356910eb877e71df9f32b0a6215324Chris Lattner // then 'or' into place. 1305800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *SV = SI->getOperand(0); 1306800de31776356910eb877e71df9f32b0a6215324Chris Lattner const Type *AllocaType = NewAI->getType()->getElementType(); 1307800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (SV->getType() == AllocaType && Offset == 0) { 1308800de31776356910eb877e71df9f32b0a6215324Chris Lattner // All is well. 1309800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else if (const VectorType *PTy = dyn_cast<VectorType>(AllocaType)) { 1310800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *Old = new LoadInst(NewAI, NewAI->getName()+".in", SI); 1311800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1312800de31776356910eb877e71df9f32b0a6215324Chris Lattner // If the result alloca is a vector type, this is either an element 1313800de31776356910eb877e71df9f32b0a6215324Chris Lattner // access or a bitcast to another vector type. 1314800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (isa<VectorType>(SV->getType())) { 1315800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV = new BitCastInst(SV, AllocaType, SV->getName(), SI); 1316800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else { 1317800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Must be an element insertion. 1318800de31776356910eb877e71df9f32b0a6215324Chris Lattner const TargetData &TD = getAnalysis<TargetData>(); 1319800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned Elt = Offset/TD.getABITypeSizeInBits(PTy->getElementType()); 1320051a950000e21935165db56695e35bade668193bGabor Greif SV = InsertElementInst::Create(Old, SV, 1321051a950000e21935165db56695e35bade668193bGabor Greif ConstantInt::get(Type::Int32Ty, Elt), 1322051a950000e21935165db56695e35bade668193bGabor Greif "tmp", SI); 1323800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 1324800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else if (isa<PointerType>(AllocaType)) { 1325800de31776356910eb877e71df9f32b0a6215324Chris Lattner // If the alloca type is a pointer, then all the elements must be 1326800de31776356910eb877e71df9f32b0a6215324Chris Lattner // pointers. 1327800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (SV->getType() != AllocaType) 1328800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV = new BitCastInst(SV, AllocaType, SV->getName(), SI); 1329800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else { 1330800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *Old = new LoadInst(NewAI, NewAI->getName()+".in", SI); 1331800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1332800de31776356910eb877e71df9f32b0a6215324Chris Lattner // If SV is a float, convert it to the appropriate integer type. 1333800de31776356910eb877e71df9f32b0a6215324Chris Lattner // If it is a pointer, do the same, and also handle ptr->ptr casts 1334800de31776356910eb877e71df9f32b0a6215324Chris Lattner // here. 1335800de31776356910eb877e71df9f32b0a6215324Chris Lattner const TargetData &TD = getAnalysis<TargetData>(); 1336800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned SrcWidth = TD.getTypeSizeInBits(SV->getType()); 1337800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned DestWidth = TD.getTypeSizeInBits(AllocaType); 1338800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned SrcStoreWidth = TD.getTypeStoreSizeInBits(SV->getType()); 1339800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned DestStoreWidth = TD.getTypeStoreSizeInBits(AllocaType); 1340800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (SV->getType()->isFloatingPoint()) 1341800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV = new BitCastInst(SV, IntegerType::get(SrcWidth), 1342800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV->getName(), SI); 1343800de31776356910eb877e71df9f32b0a6215324Chris Lattner else if (isa<PointerType>(SV->getType())) 1344800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV = new PtrToIntInst(SV, TD.getIntPtrType(), SV->getName(), SI); 1345800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1346800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Always zero extend the value if needed. 1347800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (SV->getType() != AllocaType) 1348800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV = new ZExtInst(SV, AllocaType, SV->getName(), SI); 1349800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1350800de31776356910eb877e71df9f32b0a6215324Chris Lattner // If this is a big-endian system and the store is narrower than the 1351800de31776356910eb877e71df9f32b0a6215324Chris Lattner // full alloca type, we need to do a shift to get the right bits. 1352800de31776356910eb877e71df9f32b0a6215324Chris Lattner int ShAmt = 0; 1353800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (TD.isBigEndian()) { 1354800de31776356910eb877e71df9f32b0a6215324Chris Lattner // On big-endian machines, the lowest bit is stored at the bit offset 1355800de31776356910eb877e71df9f32b0a6215324Chris Lattner // from the pointer given by getTypeStoreSizeInBits. This matters for 1356800de31776356910eb877e71df9f32b0a6215324Chris Lattner // integers with a bitwidth that is not a multiple of 8. 1357800de31776356910eb877e71df9f32b0a6215324Chris Lattner ShAmt = DestStoreWidth - SrcStoreWidth - Offset; 1358800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else { 1359800de31776356910eb877e71df9f32b0a6215324Chris Lattner ShAmt = Offset; 1360800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 1361800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1362800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Note: we support negative bitwidths (with shr) which are not defined. 1363800de31776356910eb877e71df9f32b0a6215324Chris Lattner // We do this to support (f.e.) stores off the end of a structure where 1364800de31776356910eb877e71df9f32b0a6215324Chris Lattner // only some bits in the structure are set. 1365800de31776356910eb877e71df9f32b0a6215324Chris Lattner APInt Mask(APInt::getLowBitsSet(DestWidth, SrcWidth)); 1366800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (ShAmt > 0 && (unsigned)ShAmt < DestWidth) { 13677cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif SV = BinaryOperator::CreateShl(SV, 1368800de31776356910eb877e71df9f32b0a6215324Chris Lattner ConstantInt::get(SV->getType(), ShAmt), 1369800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV->getName(), SI); 1370800de31776356910eb877e71df9f32b0a6215324Chris Lattner Mask <<= ShAmt; 1371800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else if (ShAmt < 0 && (unsigned)-ShAmt < DestWidth) { 13727cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif SV = BinaryOperator::CreateLShr(SV, 1373800de31776356910eb877e71df9f32b0a6215324Chris Lattner ConstantInt::get(SV->getType(),-ShAmt), 1374800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV->getName(), SI); 1375800de31776356910eb877e71df9f32b0a6215324Chris Lattner Mask = Mask.lshr(ShAmt); 1376800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 1377800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1378800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Mask out the bits we are about to insert from the old value, and or 1379800de31776356910eb877e71df9f32b0a6215324Chris Lattner // in the new bits. 1380800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (SrcWidth != DestWidth) { 1381800de31776356910eb877e71df9f32b0a6215324Chris Lattner assert(DestWidth > SrcWidth); 13827cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif Old = BinaryOperator::CreateAnd(Old, ConstantInt::get(~Mask), 1383800de31776356910eb877e71df9f32b0a6215324Chris Lattner Old->getName()+".mask", SI); 13847cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif SV = BinaryOperator::CreateOr(Old, SV, SV->getName()+".ins", SI); 1385800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 1386800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 1387800de31776356910eb877e71df9f32b0a6215324Chris Lattner return SV; 1388800de31776356910eb877e71df9f32b0a6215324Chris Lattner} 1389800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1390800de31776356910eb877e71df9f32b0a6215324Chris Lattner 139179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 139279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// PointsToConstantGlobal - Return true if V (possibly indirectly) points to 139379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// some part of a constant global variable. This intentionally only accepts 139479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// constant expressions because we don't can't rewrite arbitrary instructions. 139579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattnerstatic bool PointsToConstantGlobal(Value *V) { 139679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) 139779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return GV->isConstant(); 139879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) 139979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (CE->getOpcode() == Instruction::BitCast || 140079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner CE->getOpcode() == Instruction::GetElementPtr) 140179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return PointsToConstantGlobal(CE->getOperand(0)); 140279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return false; 140379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner} 140479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 140579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// isOnlyCopiedFromConstantGlobal - Recursively walk the uses of a (derived) 140679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// pointer to an alloca. Ignore any reads of the pointer, return false if we 140779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// see any stores or other unknown uses. If we see pointer arithmetic, keep 140879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// track of whether it moves the pointer (with isOffset) but otherwise traverse 140979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// the uses. If we see a memcpy/memmove that targets an unoffseted pointer to 141079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// the alloca, and if the source pointer is a pointer to a constant global, we 141179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// can optimize this. 141279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattnerstatic bool isOnlyCopiedFromConstantGlobal(Value *V, Instruction *&TheCopy, 141379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner bool isOffset) { 141479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI!=E; ++UI) { 141579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (isa<LoadInst>(*UI)) { 141679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // Ignore loads, they are always ok. 141779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner continue; 141879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner } 141979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (BitCastInst *BCI = dyn_cast<BitCastInst>(*UI)) { 142079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If uses of the bitcast are ok, we are ok. 142179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (!isOnlyCopiedFromConstantGlobal(BCI, TheCopy, isOffset)) 142279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return false; 142379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner continue; 142479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner } 142579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(*UI)) { 142679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If the GEP has all zero indices, it doesn't offset the pointer. If it 142779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // doesn't, it does. 142879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (!isOnlyCopiedFromConstantGlobal(GEP, TheCopy, 142979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner isOffset || !GEP->hasAllZeroIndices())) 143079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return false; 143179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner continue; 143279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner } 143379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 143479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If this is isn't our memcpy/memmove, reject it as something we can't 143579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // handle. 143679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (!isa<MemCpyInst>(*UI) && !isa<MemMoveInst>(*UI)) 143779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return false; 143879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 143979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If we already have seen a copy, reject the second one. 144079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (TheCopy) return false; 144179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 144279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If the pointer has been offset from the start of the alloca, we can't 144379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // safely handle this. 144479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (isOffset) return false; 144579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 144679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If the memintrinsic isn't using the alloca as the dest, reject it. 144779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (UI.getOperandNo() != 1) return false; 144879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 144979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner MemIntrinsic *MI = cast<MemIntrinsic>(*UI); 145079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 145179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If the source of the memcpy/move is not a constant global, reject it. 145279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (!PointsToConstantGlobal(MI->getOperand(2))) 145379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return false; 145479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 145579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // Otherwise, the transform is safe. Remember the copy instruction. 145679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner TheCopy = MI; 145779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner } 145879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return true; 145979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner} 146079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 146179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// isOnlyCopiedFromConstantGlobal - Return true if the specified alloca is only 146279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// modified by a copy from a constant global. If we can prove this, we can 146379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// replace any uses of the alloca with uses of the global directly. 146479b3bd395dc3303cde65e18e0524ed2f70268c99Chris LattnerInstruction *SROA::isOnlyCopiedFromConstantGlobal(AllocationInst *AI) { 146579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner Instruction *TheCopy = 0; 146679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (::isOnlyCopiedFromConstantGlobal(AI, TheCopy, false)) 146779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return TheCopy; 146879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return 0; 146979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner} 1470