ScalarReplAggregates.cpp revision d93afec1dbbb1abb3df55e2e007b5f256d09f84a
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 51ae73dc1448d25b02cabc7c64c86c64371453dda8Dan Gohman explicit SROA(signed T = -1) : FunctionPass(&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: 7356c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner TargetData *TD; 7456c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner 7539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// AllocaInfo - When analyzing uses of an alloca instruction, this captures 7639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// information about the uses. All these fields are initialized to false 7739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// and set to true when something is learned. 7839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner struct AllocaInfo { 7939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// isUnsafe - This is set to true if the alloca cannot be SROA'd. 8039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner bool isUnsafe : 1; 8139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 8239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// needsCanon - This is set to true if there is some use of the alloca 8339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// that requires canonicalization. 8439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner bool needsCanon : 1; 8539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 8639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// isMemCpySrc - This is true if this aggregate is memcpy'd from. 8739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner bool isMemCpySrc : 1; 8839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 8933b0b8d242de8d428f11e77ea734a08b47797216Zhou Sheng /// isMemCpyDst - This is true if this aggregate is memcpy'd into. 9039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner bool isMemCpyDst : 1; 9139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 9239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo() 9339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner : isUnsafe(false), needsCanon(false), 9439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isMemCpySrc(false), isMemCpyDst(false) {} 9539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner }; 9639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 97ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel unsigned SRThreshold; 98ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel 9939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner void MarkUnsafe(AllocaInfo &I) { I.isUnsafe = true; } 10039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 101f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner int isSafeAllocaToScalarRepl(AllocationInst *AI); 10239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 10339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner void isSafeUseOfAllocation(Instruction *User, AllocationInst *AI, 10439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo &Info); 10539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner void isSafeElementUse(Value *Ptr, bool isFirstElt, AllocationInst *AI, 10639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo &Info); 10739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner void isSafeMemIntrinsicOnAllocation(MemIntrinsic *MI, AllocationInst *AI, 10839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner unsigned OpNo, AllocaInfo &Info); 10939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner void isSafeUseOfBitCastedAllocation(BitCastInst *User, AllocationInst *AI, 11039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo &Info); 11139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 112a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner void DoScalarReplacement(AllocationInst *AI, 113a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner std::vector<AllocationInst*> &WorkList); 114f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner void CanonicalizeAllocaUsers(AllocationInst *AI); 115ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner AllocaInst *AddNewAlloca(Function &F, const Type *Ty, AllocationInst *Base); 116a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1178bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner void RewriteBitCastUserOfAlloca(Instruction *BCInst, AllocationInst *AI, 118372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner SmallVector<AllocaInst*, 32> &NewElts); 119372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 120d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner void RewriteMemIntrinUserOfAlloca(MemIntrinsic *MI, Instruction *BCInst, 121d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner AllocationInst *AI, 122d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner SmallVector<AllocaInst*, 32> &NewElts); 123d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner 124d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner 125a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *CanConvertToScalar(Value *V, bool &IsNotTrivial); 126a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner void ConvertToScalar(AllocationInst *AI, const Type *Ty); 127a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner void ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI, unsigned Offset); 128800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *ConvertUsesOfLoadToScalar(LoadInst *LI, AllocaInst *NewAI, 129800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned Offset); 130800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *ConvertUsesOfStoreToScalar(StoreInst *SI, AllocaInst *NewAI, 131800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned Offset); 13279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner static Instruction *isOnlyCopiedFromConstantGlobal(AllocationInst *AI); 133ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner }; 134ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner} 135ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 136844731a7f1909f55935e3514c9e713a62d67662eDan Gohmanchar SROA::ID = 0; 137844731a7f1909f55935e3514c9e713a62d67662eDan Gohmanstatic RegisterPass<SROA> X("scalarrepl", "Scalar Replacement of Aggregates"); 138844731a7f1909f55935e3514c9e713a62d67662eDan Gohman 139d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke// Public interface to the ScalarReplAggregates pass 140ff366850aa9956e167e78d4f5b57aae10d8c5779Devang PatelFunctionPass *llvm::createScalarReplAggregatesPass(signed int Threshold) { 141ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel return new SROA(Threshold); 142ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel} 143ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 144ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 145ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattnerbool SROA::runOnFunction(Function &F) { 14656c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner TD = &getAnalysis<TargetData>(); 14756c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner 148fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner bool Changed = performPromotion(F); 149fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner while (1) { 150fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner bool LocalChange = performScalarRepl(F); 151fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner if (!LocalChange) break; // No need to repromote if no scalarrepl 152fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner Changed = true; 153fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner LocalChange = performPromotion(F); 154fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner if (!LocalChange) break; // No need to re-scalarrepl if no promotion 155fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner } 15638aec325604635380421a27e39ab06d55ed2458dChris Lattner 15738aec325604635380421a27e39ab06d55ed2458dChris Lattner return Changed; 15838aec325604635380421a27e39ab06d55ed2458dChris Lattner} 15938aec325604635380421a27e39ab06d55ed2458dChris Lattner 16038aec325604635380421a27e39ab06d55ed2458dChris Lattner 16138aec325604635380421a27e39ab06d55ed2458dChris Lattnerbool SROA::performPromotion(Function &F) { 16238aec325604635380421a27e39ab06d55ed2458dChris Lattner std::vector<AllocaInst*> Allocas; 163326821ef12c911af1d785e305e81dc3c07e456a5Devang Patel DominatorTree &DT = getAnalysis<DominatorTree>(); 16443f820d1f7638656be2158efac7dd8f5b08b8b77Chris Lattner DominanceFrontier &DF = getAnalysis<DominanceFrontier>(); 16538aec325604635380421a27e39ab06d55ed2458dChris Lattner 16602a3be020a6b4eedb4b489959997d23a22cdf22eChris Lattner BasicBlock &BB = F.getEntryBlock(); // Get the entry node for the function 16738aec325604635380421a27e39ab06d55ed2458dChris Lattner 168fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner bool Changed = false; 169fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 17038aec325604635380421a27e39ab06d55ed2458dChris Lattner while (1) { 17138aec325604635380421a27e39ab06d55ed2458dChris Lattner Allocas.clear(); 17238aec325604635380421a27e39ab06d55ed2458dChris Lattner 17338aec325604635380421a27e39ab06d55ed2458dChris Lattner // Find allocas that are safe to promote, by looking at all instructions in 17438aec325604635380421a27e39ab06d55ed2458dChris Lattner // the entry node 17538aec325604635380421a27e39ab06d55ed2458dChris Lattner for (BasicBlock::iterator I = BB.begin(), E = --BB.end(); I != E; ++I) 17638aec325604635380421a27e39ab06d55ed2458dChris Lattner if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) // Is it an alloca? 17741968df51e11f581eb19c8f68a8cb2f4e8acc1c5Devang Patel if (isAllocaPromotable(AI)) 17838aec325604635380421a27e39ab06d55ed2458dChris Lattner Allocas.push_back(AI); 17938aec325604635380421a27e39ab06d55ed2458dChris Lattner 18038aec325604635380421a27e39ab06d55ed2458dChris Lattner if (Allocas.empty()) break; 18138aec325604635380421a27e39ab06d55ed2458dChris Lattner 182326821ef12c911af1d785e305e81dc3c07e456a5Devang Patel PromoteMemToReg(Allocas, DT, DF); 18338aec325604635380421a27e39ab06d55ed2458dChris Lattner NumPromoted += Allocas.size(); 18438aec325604635380421a27e39ab06d55ed2458dChris Lattner Changed = true; 18538aec325604635380421a27e39ab06d55ed2458dChris Lattner } 18638aec325604635380421a27e39ab06d55ed2458dChris Lattner 18738aec325604635380421a27e39ab06d55ed2458dChris Lattner return Changed; 18838aec325604635380421a27e39ab06d55ed2458dChris Lattner} 18938aec325604635380421a27e39ab06d55ed2458dChris Lattner 190963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner/// getNumSAElements - Return the number of elements in the specific struct or 191963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner/// array. 192963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattnerstatic uint64_t getNumSAElements(const Type *T) { 193963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner if (const StructType *ST = dyn_cast<StructType>(T)) 194963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner return ST->getNumElements(); 195963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner return cast<ArrayType>(T)->getNumElements(); 196963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner} 197963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner 19838aec325604635380421a27e39ab06d55ed2458dChris Lattner// performScalarRepl - This algorithm is a simple worklist driven algorithm, 19938aec325604635380421a27e39ab06d55ed2458dChris Lattner// which runs on all of the malloc/alloca instructions in the function, removing 20038aec325604635380421a27e39ab06d55ed2458dChris Lattner// them if they are only used by getelementptr instructions. 20138aec325604635380421a27e39ab06d55ed2458dChris Lattner// 20238aec325604635380421a27e39ab06d55ed2458dChris Lattnerbool SROA::performScalarRepl(Function &F) { 203ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner std::vector<AllocationInst*> WorkList; 204ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 205ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner // Scan the entry basic block, adding any alloca's and mallocs to the worklist 20602a3be020a6b4eedb4b489959997d23a22cdf22eChris Lattner BasicBlock &BB = F.getEntryBlock(); 207ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E; ++I) 208ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner if (AllocationInst *A = dyn_cast<AllocationInst>(I)) 209ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner WorkList.push_back(A); 210ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 211ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner // Process the worklist 212ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner bool Changed = false; 213ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner while (!WorkList.empty()) { 214ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner AllocationInst *AI = WorkList.back(); 215ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner WorkList.pop_back(); 216a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 217add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner // Handle dead allocas trivially. These can be formed by SROA'ing arrays 218add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner // with unused elements. 219add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner if (AI->use_empty()) { 220add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner AI->eraseFromParent(); 221add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner continue; 222add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner } 223add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner 224a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // If we can turn this aggregate value (potentially with casts) into a 225a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // simple scalar value that can be mem2reg'd into a register value. 226a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner bool IsNotTrivial = false; 227a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (const Type *ActualType = CanConvertToScalar(AI, IsNotTrivial)) 228df4f226cdcbe853984ddda10aa0d53590d35b97eChris Lattner if (IsNotTrivial && ActualType != Type::VoidTy) { 229a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner ConvertToScalar(AI, ActualType); 230a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner Changed = true; 231a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner continue; 232a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 233ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 23479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // Check to see if we can perform the core SROA transformation. We cannot 23579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // transform the allocation instruction if it is an array allocation 23679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // (allocations OF arrays are ok though), and an allocation of a scalar 23779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // value cannot be decomposed at all. 238a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner if (!AI->isArrayAllocation() && 239a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner (isa<StructType>(AI->getAllocatedType()) || 2407139406707eb3869183fd6a3329fe4a77d309692Chris Lattner isa<ArrayType>(AI->getAllocatedType())) && 2417139406707eb3869183fd6a3329fe4a77d309692Chris Lattner AI->getAllocatedType()->isSized() && 242963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner // Do not promote any struct whose size is larger than "128" bytes. 24356c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner TD->getABITypeSize(AI->getAllocatedType()) < SRThreshold && 244963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner // Do not promote any struct into more than "32" separate vars. 245963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner getNumSAElements(AI->getAllocatedType()) < SRThreshold/4) { 246a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Check that all of the users of the allocation are capable of being 247a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // transformed. 248a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner switch (isSafeAllocaToScalarRepl(AI)) { 249a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner default: assert(0 && "Unexpected value!"); 250a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner case 0: // Not safe to scalar replace. 251a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner break; 252a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner case 1: // Safe, but requires cleanup/canonicalizations first 253a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner CanonicalizeAllocaUsers(AI); 254a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // FALL THROUGH. 255a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner case 3: // Safe to scalar replace. 256a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner DoScalarReplacement(AI, WorkList); 257a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner Changed = true; 258a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner continue; 259a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 260f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner } 26179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 26279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // Check to see if this allocation is only modified by a memcpy/memmove from 26379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // a constant global. If this is the case, we can change all users to use 26479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // the constant global instead. This is commonly produced by the CFE by 26579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // constructs like "void foo() { int A[] = {1,2,3,4,5,6,7,8,9...}; }" if 'A' 26679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // is only subsequently read. 26779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (Instruction *TheCopy = isOnlyCopiedFromConstantGlobal(AI)) { 26879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner DOUT << "Found alloca equal to global: " << *AI; 26979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner DOUT << " memcpy = " << *TheCopy; 27079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner Constant *TheSrc = cast<Constant>(TheCopy->getOperand(2)); 27179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner AI->replaceAllUsesWith(ConstantExpr::getBitCast(TheSrc, AI->getType())); 27279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner TheCopy->eraseFromParent(); // Don't mutate the global. 27379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner AI->eraseFromParent(); 27479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner ++NumGlobals; 27579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner Changed = true; 27679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner continue; 27779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner } 278a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner 279a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Otherwise, couldn't process this. 280a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 281ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 282a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner return Changed; 283a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner} 284fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 285a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner/// DoScalarReplacement - This alloca satisfied the isSafeAllocaToScalarRepl 286a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner/// predicate, do SROA now. 287a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattnervoid SROA::DoScalarReplacement(AllocationInst *AI, 288a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner std::vector<AllocationInst*> &WorkList) { 28979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner DOUT << "Found inst to SROA: " << *AI; 290a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner SmallVector<AllocaInst*, 32> ElementAllocas; 291a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner if (const StructType *ST = dyn_cast<StructType>(AI->getAllocatedType())) { 292a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner ElementAllocas.reserve(ST->getNumContainedTypes()); 293a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner for (unsigned i = 0, e = ST->getNumContainedTypes(); i != e; ++i) { 294a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AllocaInst *NA = new AllocaInst(ST->getContainedType(i), 0, 295a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AI->getAlignment(), 296a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AI->getName() + "." + utostr(i), AI); 297a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner ElementAllocas.push_back(NA); 298a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner WorkList.push_back(NA); // Add to worklist for recursive processing 299a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 300a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } else { 301a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner const ArrayType *AT = cast<ArrayType>(AI->getAllocatedType()); 302a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner ElementAllocas.reserve(AT->getNumElements()); 303a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner const Type *ElTy = AT->getElementType(); 304a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner for (unsigned i = 0, e = AT->getNumElements(); i != e; ++i) { 305a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AllocaInst *NA = new AllocaInst(ElTy, 0, AI->getAlignment(), 306a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AI->getName() + "." + utostr(i), AI); 307a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner ElementAllocas.push_back(NA); 308a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner WorkList.push_back(NA); // Add to worklist for recursive processing 309ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner } 310a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 311fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 312a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Now that we have created the alloca instructions that we want to use, 313a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // expand the getelementptr instructions to use them. 314a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // 315a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner while (!AI->use_empty()) { 316a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner Instruction *User = cast<Instruction>(AI->use_back()); 317a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner if (BitCastInst *BCInst = dyn_cast<BitCastInst>(User)) { 318a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner RewriteBitCastUserOfAlloca(BCInst, AI, ElementAllocas); 319a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner BCInst->eraseFromParent(); 320a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner continue; 321a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 322a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner 3232a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // Replace: 3242a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // %res = load { i32, i32 }* %alloc 3252a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // with: 3262a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // %load.0 = load i32* %alloc.0 3272a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // %insert.0 insertvalue { i32, i32 } zeroinitializer, i32 %load.0, 0 3282a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // %load.1 = load i32* %alloc.1 3292a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // %insert = insertvalue { i32, i32 } %insert.0, i32 %load.1, 1 33002518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman // (Also works for arrays instead of structs) 33102518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman if (LoadInst *LI = dyn_cast<LoadInst>(User)) { 33202518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman Value *Insert = UndefValue::get(LI->getType()); 33302518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman for (unsigned i = 0, e = ElementAllocas.size(); i != e; ++i) { 33402518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman Value *Load = new LoadInst(ElementAllocas[i], "load", LI); 33502518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman Insert = InsertValueInst::Create(Insert, Load, i, "insert", LI); 33602518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman } 33702518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman LI->replaceAllUsesWith(Insert); 33802518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman LI->eraseFromParent(); 33902518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman continue; 34002518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman } 34102518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman 3422a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // Replace: 3432a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // store { i32, i32 } %val, { i32, i32 }* %alloc 3442a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // with: 3452a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // %val.0 = extractvalue { i32, i32 } %val, 0 3462a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // store i32 %val.0, i32* %alloc.0 3472a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // %val.1 = extractvalue { i32, i32 } %val, 1 3482a6a6457094e05e5f5ab34f90dbd25c13d61f8b5Chris Lattner // store i32 %val.1, i32* %alloc.1 34902518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman // (Also works for arrays instead of structs) 35002518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman if (StoreInst *SI = dyn_cast<StoreInst>(User)) { 35102518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman Value *Val = SI->getOperand(0); 35202518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman for (unsigned i = 0, e = ElementAllocas.size(); i != e; ++i) { 35302518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman Value *Extract = ExtractValueInst::Create(Val, i, Val->getName(), SI); 35402518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman new StoreInst(Extract, ElementAllocas[i], SI); 35502518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman } 35602518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman SI->eraseFromParent(); 35702518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman continue; 35802518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman } 35902518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman 360a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner GetElementPtrInst *GEPI = cast<GetElementPtrInst>(User); 361a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // We now know that the GEP is of the form: GEP <ptr>, 0, <cst> 362a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner unsigned Idx = 363a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner (unsigned)cast<ConstantInt>(GEPI->getOperand(2))->getZExtValue(); 364a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner 365a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner assert(Idx < ElementAllocas.size() && "Index out of range?"); 366a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AllocaInst *AllocaToUse = ElementAllocas[Idx]; 367a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner 368a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner Value *RepValue; 369a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner if (GEPI->getNumOperands() == 3) { 370a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Do not insert a new getelementptr instruction with zero indices, only 371a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // to have it optimized out later. 372a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner RepValue = AllocaToUse; 373a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } else { 374a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // We are indexing deeply into the structure, so we still need a 375a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // getelement ptr instruction to finish the indexing. This may be 376a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // expanded itself once the worklist is rerun. 377a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // 378a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner SmallVector<Value*, 8> NewArgs; 379a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner NewArgs.push_back(Constant::getNullValue(Type::Int32Ty)); 380a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner NewArgs.append(GEPI->op_begin()+3, GEPI->op_end()); 381051a950000e21935165db56695e35bade668193bGabor Greif RepValue = GetElementPtrInst::Create(AllocaToUse, NewArgs.begin(), 382051a950000e21935165db56695e35bade668193bGabor Greif NewArgs.end(), "", GEPI); 383a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner RepValue->takeName(GEPI); 384a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 385a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner 386a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // If this GEP is to the start of the aggregate, check for memcpys. 387d356a7ee0ed7744857dcf497cb20b0128770fb0fChris Lattner if (Idx == 0 && GEPI->hasAllZeroIndices()) 388d356a7ee0ed7744857dcf497cb20b0128770fb0fChris Lattner RewriteBitCastUserOfAlloca(GEPI, AI, ElementAllocas); 389ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 390a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Move all of the users over to the new GEP. 391a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner GEPI->replaceAllUsesWith(RepValue); 392a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Delete the old GEP 393a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner GEPI->eraseFromParent(); 394ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner } 395ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 396a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Finally, delete the Alloca instruction 397a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AI->eraseFromParent(); 398a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner NumReplaced++; 399ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner} 4005e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner 4015e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner 402f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// isSafeElementUse - Check to see if this use is an allowed use for a 4038bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// getelementptr instruction of an array aggregate allocation. isFirstElt 4048bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// indicates whether Ptr is known to the start of the aggregate. 405f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// 40639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattnervoid SROA::isSafeElementUse(Value *Ptr, bool isFirstElt, AllocationInst *AI, 40739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo &Info) { 408f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner for (Value::use_iterator I = Ptr->use_begin(), E = Ptr->use_end(); 409f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner I != E; ++I) { 410f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner Instruction *User = cast<Instruction>(*I); 411f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner switch (User->getOpcode()) { 412f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner case Instruction::Load: break; 413f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner case Instruction::Store: 414f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner // Store is ok if storing INTO the pointer, not storing the pointer 41539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (User->getOperand(0) == Ptr) return MarkUnsafe(Info); 416f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner break; 417f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner case Instruction::GetElementPtr: { 418f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner GetElementPtrInst *GEP = cast<GetElementPtrInst>(User); 4198bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner bool AreAllZeroIndices = isFirstElt; 420f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner if (GEP->getNumOperands() > 1) { 4218bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner if (!isa<ConstantInt>(GEP->getOperand(1)) || 4228bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner !cast<ConstantInt>(GEP->getOperand(1))->isZero()) 42339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // Using pointer arithmetic to navigate the array. 42439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 4258bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 426d356a7ee0ed7744857dcf497cb20b0128770fb0fChris Lattner if (AreAllZeroIndices) 427d356a7ee0ed7744857dcf497cb20b0128770fb0fChris Lattner AreAllZeroIndices = GEP->hasAllZeroIndices(); 428f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner } 42939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isSafeElementUse(GEP, AreAllZeroIndices, AI, Info); 43039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (Info.isUnsafe) return; 431f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner break; 432f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner } 4338bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner case Instruction::BitCast: 43439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (isFirstElt) { 43539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isSafeUseOfBitCastedAllocation(cast<BitCastInst>(User), AI, Info); 43639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (Info.isUnsafe) return; 4378bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner break; 43839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 4398bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner DOUT << " Transformation preventing inst: " << *User; 44039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 4418bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner case Instruction::Call: 4428bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(User)) { 44339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (isFirstElt) { 44439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isSafeMemIntrinsicOnAllocation(MI, AI, I.getOperandNo(), Info); 44539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (Info.isUnsafe) return; 4468bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner break; 44739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 4488bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner } 4498bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner DOUT << " Transformation preventing inst: " << *User; 45039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 451f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner default: 452b7427031372337e6d67f9573ec6c722ab5ea913eBill Wendling DOUT << " Transformation preventing inst: " << *User; 45339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 454f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner } 455f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner } 45639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return; // All users look ok :) 457f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner} 458f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner 459d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner/// AllUsersAreLoads - Return true if all users of this value are loads. 460d878ecd904e4469344a2274f9784422c2c68b81cChris Lattnerstatic bool AllUsersAreLoads(Value *Ptr) { 461d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner for (Value::use_iterator I = Ptr->use_begin(), E = Ptr->use_end(); 462d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner I != E; ++I) 463d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner if (cast<Instruction>(*I)->getOpcode() != Instruction::Load) 464d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner return false; 465fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman return true; 466d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner} 467d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner 4685e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner/// isSafeUseOfAllocation - Check to see if this user is an allowed use for an 4695e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner/// aggregate allocation. 4705e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner/// 47139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattnervoid SROA::isSafeUseOfAllocation(Instruction *User, AllocationInst *AI, 47239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo &Info) { 473372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (BitCastInst *C = dyn_cast<BitCastInst>(User)) 47439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return isSafeUseOfBitCastedAllocation(C, AI, Info); 47539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 47602518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman if (isa<LoadInst>(User)) 47702518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman return; // Loads (returning a first class aggregrate) are always rewritable 47802518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman 47902518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman if (isa<StoreInst>(User) && User->getOperand(0) != AI) 48002518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman return; // Store is ok if storing INTO the pointer, not storing the pointer 48102518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman 48239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(User); 48339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (GEPI == 0) 48439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 485546fc40d69ce4051b48112aafedd1e41f4a13195Chris Lattner 486be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner gep_type_iterator I = gep_type_begin(GEPI), E = gep_type_end(GEPI); 487be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner 48825de486263abc1882498a8701e3eb29ee0804c4eChris Lattner // The GEP is not safe to transform if not of the form "GEP <ptr>, 0, <cst>". 489be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner if (I == E || 49039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner I.getOperand() != Constant::getNullValue(I.getOperand()->getType())) { 49139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 49239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 493be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner 494be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner ++I; 49539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (I == E) return MarkUnsafe(Info); // ran out of GEP indices?? 496546fc40d69ce4051b48112aafedd1e41f4a13195Chris Lattner 4978bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner bool IsAllZeroIndices = true; 4988bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 49988e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner // If the first index is a non-constant index into an array, see if we can 50088e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner // handle it as a special case. 501be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner if (const ArrayType *AT = dyn_cast<ArrayType>(*I)) { 50288e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner if (!isa<ConstantInt>(I.getOperand())) { 5038bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner IsAllZeroIndices = 0; 50488e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner uint64_t NumElements = AT->getNumElements(); 5058bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 506d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // If this is an array index and the index is not constant, we cannot 507d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // promote... that is unless the array has exactly one or two elements in 508d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // it, in which case we CAN promote it, but we have to canonicalize this 509d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // out if this is the only problem. 51025de486263abc1882498a8701e3eb29ee0804c4eChris Lattner if ((NumElements == 1 || NumElements == 2) && 51139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllUsersAreLoads(GEPI)) { 51239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner Info.needsCanon = true; 51339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return; // Canonicalization required! 51439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 51539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 516d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } 5175e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner } 5185fac55fafb53fde5c548bcd08e07418e9d8e549fMatthijs Kooijman 51988e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner // Walk through the GEP type indices, checking the types that this indexes 52088e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner // into. 52188e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner for (; I != E; ++I) { 52288e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner // Ignore struct elements, no extra checking needed for these. 52388e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner if (isa<StructType>(*I)) 52488e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner continue; 52588e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner 52688e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner ConstantInt *IdxVal = dyn_cast<ConstantInt>(I.getOperand()); 52788e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner if (!IdxVal) return MarkUnsafe(Info); 5285fac55fafb53fde5c548bcd08e07418e9d8e549fMatthijs Kooijman 5295fac55fafb53fde5c548bcd08e07418e9d8e549fMatthijs Kooijman // Are all indices still zero? 53088e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner IsAllZeroIndices &= IdxVal->isZero(); 5315fac55fafb53fde5c548bcd08e07418e9d8e549fMatthijs Kooijman 5325fac55fafb53fde5c548bcd08e07418e9d8e549fMatthijs Kooijman if (const ArrayType *AT = dyn_cast<ArrayType>(*I)) { 5335fac55fafb53fde5c548bcd08e07418e9d8e549fMatthijs Kooijman // This GEP indexes an array. Verify that this is an in-range constant 5345fac55fafb53fde5c548bcd08e07418e9d8e549fMatthijs Kooijman // integer. Specifically, consider A[0][i]. We cannot know that the user 5355fac55fafb53fde5c548bcd08e07418e9d8e549fMatthijs Kooijman // isn't doing invalid things like allowing i to index an out-of-range 5365fac55fafb53fde5c548bcd08e07418e9d8e549fMatthijs Kooijman // subscript that accesses A[1]. Because of this, we have to reject SROA 537c0bc547c99bd97088e950b3074d917091abe3f51Dale Johannesen // of any accesses into structs where any of the components are variables. 5385fac55fafb53fde5c548bcd08e07418e9d8e549fMatthijs Kooijman if (IdxVal->getZExtValue() >= AT->getNumElements()) 5395fac55fafb53fde5c548bcd08e07418e9d8e549fMatthijs Kooijman return MarkUnsafe(Info); 540c0bc547c99bd97088e950b3074d917091abe3f51Dale Johannesen } else if (const VectorType *VT = dyn_cast<VectorType>(*I)) { 541c0bc547c99bd97088e950b3074d917091abe3f51Dale Johannesen if (IdxVal->getZExtValue() >= VT->getNumElements()) 542c0bc547c99bd97088e950b3074d917091abe3f51Dale Johannesen return MarkUnsafe(Info); 5435fac55fafb53fde5c548bcd08e07418e9d8e549fMatthijs Kooijman } 54488e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner } 54588e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner 546be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner // If there are any non-simple uses of this getelementptr, make sure to reject 547be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner // them. 54839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return isSafeElementUse(GEPI, IsAllZeroIndices, AI, Info); 5498bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner} 5508bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 5518bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// isSafeMemIntrinsicOnAllocation - Return true if the specified memory 5528bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// intrinsic can be promoted by SROA. At this point, we know that the operand 5538bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// of the memintrinsic is a pointer to the beginning of the allocation. 55439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattnervoid SROA::isSafeMemIntrinsicOnAllocation(MemIntrinsic *MI, AllocationInst *AI, 55539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner unsigned OpNo, AllocaInfo &Info) { 5568bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner // If not constant length, give up. 5578bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner ConstantInt *Length = dyn_cast<ConstantInt>(MI->getLength()); 55839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (!Length) return MarkUnsafe(Info); 5598bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 5608bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner // If not the whole aggregate, give up. 5613cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands if (Length->getZExtValue() != 56256c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner TD->getABITypeSize(AI->getType()->getElementType())) 56339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 5648bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 5658bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner // We only know about memcpy/memset/memmove. 5668bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner if (!isa<MemCpyInst>(MI) && !isa<MemSetInst>(MI) && !isa<MemMoveInst>(MI)) 56739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 56839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 56939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // Otherwise, we can transform it. Determine whether this is a memcpy/set 57039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // into or out of the aggregate. 57139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (OpNo == 1) 57239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner Info.isMemCpyDst = true; 57339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner else { 57439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner assert(OpNo == 2); 57539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner Info.isMemCpySrc = true; 57639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 5775e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner} 5785e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner 579372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner/// isSafeUseOfBitCastedAllocation - Return true if all users of this bitcast 580372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner/// are 58139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattnervoid SROA::isSafeUseOfBitCastedAllocation(BitCastInst *BC, AllocationInst *AI, 58239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo &Info) { 583372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner for (Value::use_iterator UI = BC->use_begin(), E = BC->use_end(); 584372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner UI != E; ++UI) { 585372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (BitCastInst *BCU = dyn_cast<BitCastInst>(UI)) { 58639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isSafeUseOfBitCastedAllocation(BCU, AI, Info); 587372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } else if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(UI)) { 58839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isSafeMemIntrinsicOnAllocation(MI, AI, UI.getOperandNo(), Info); 589372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } else { 59039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 591372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 59239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (Info.isUnsafe) return; 593372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 594372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner} 595372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 5968bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// RewriteBitCastUserOfAlloca - BCInst (transitively) bitcasts AI, or indexes 5978bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// to its first element. Transform users of the cast to use the new values 5988bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// instead. 5998bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattnervoid SROA::RewriteBitCastUserOfAlloca(Instruction *BCInst, AllocationInst *AI, 600372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner SmallVector<AllocaInst*, 32> &NewElts) { 6018bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner Value::use_iterator UI = BCInst->use_begin(), UE = BCInst->use_end(); 6028bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner while (UI != UE) { 603d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner Instruction *User = cast<Instruction>(*UI++); 604d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (BitCastInst *BCU = dyn_cast<BitCastInst>(User)) { 605372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner RewriteBitCastUserOfAlloca(BCU, AI, NewElts); 6068bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner BCU->eraseFromParent(); 607372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner continue; 608372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 609372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 610d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(User)) { 611d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // This must be memcpy/memmove/memset of the entire aggregate. 612d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // Split into one per element. 613d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner RewriteMemIntrinUserOfAlloca(MI, BCInst, AI, NewElts); 614d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner MI->eraseFromParent(); 615d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner continue; 616d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner } 617d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner 6188bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner // If it's not a mem intrinsic, it must be some other user of a gep of the 6198bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner // first pointer. Just leave these alone. 620d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner continue; 621d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner } 622d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner} 623d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner 624d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner/// RewriteMemIntrinUserOfAlloca - MI is a memcpy/memset/memmove from or to AI. 625d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner/// Rewrite it to copy or set the elements of the scalarized memory. 626d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattnervoid SROA::RewriteMemIntrinUserOfAlloca(MemIntrinsic *MI, Instruction *BCInst, 627d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner AllocationInst *AI, 628d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner SmallVector<AllocaInst*, 32> &NewElts) { 629d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner 630d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // If this is a memcpy/memmove, construct the other pointer as the 631d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // appropriate type. 632d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner Value *OtherPtr = 0; 633d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (MemCpyInst *MCI = dyn_cast<MemCpyInst>(MI)) { 634d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (BCInst == MCI->getRawDest()) 635d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner OtherPtr = MCI->getRawSource(); 636d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner else { 637d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner assert(BCInst == MCI->getRawSource()); 638d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner OtherPtr = MCI->getRawDest(); 6398bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner } 640d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner } else if (MemMoveInst *MMI = dyn_cast<MemMoveInst>(MI)) { 641d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (BCInst == MMI->getRawDest()) 642d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner OtherPtr = MMI->getRawSource(); 643d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner else { 644d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner assert(BCInst == MMI->getRawSource()); 645d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner OtherPtr = MMI->getRawDest(); 646372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 647d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner } 648d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner 649d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // If there is an other pointer, we want to convert it to the same pointer 650d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // type as AI has, so we can GEP through it safely. 651d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (OtherPtr) { 652d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // It is likely that OtherPtr is a bitcast, if so, remove it. 653d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (BitCastInst *BC = dyn_cast<BitCastInst>(OtherPtr)) 654d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner OtherPtr = BC->getOperand(0); 655d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // All zero GEPs are effectively bitcasts. 656d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(OtherPtr)) 657d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (GEP->hasAllZeroIndices()) 658d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner OtherPtr = GEP->getOperand(0); 659372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 660d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (ConstantExpr *BCE = dyn_cast<ConstantExpr>(OtherPtr)) 661d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (BCE->getOpcode() == Instruction::BitCast) 662d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner OtherPtr = BCE->getOperand(0); 663d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner 664d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // If the pointer is not the right type, insert a bitcast to the right 665d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // type. 666d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (OtherPtr->getType() != AI->getType()) 667d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner OtherPtr = new BitCastInst(OtherPtr, AI->getType(), OtherPtr->getName(), 668d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner MI); 669d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner } 670d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner 671d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // Process each element of the aggregate. 672d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner Value *TheFn = MI->getOperand(0); 673d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner const Type *BytePtrTy = MI->getRawDest()->getType(); 674d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner bool SROADest = MI->getRawDest() == BCInst; 675d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner 676d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner Constant *Zero = Constant::getNullValue(Type::Int32Ty); 677372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 678d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner for (unsigned i = 0, e = NewElts.size(); i != e; ++i) { 679d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // If this is a memcpy/memmove, emit a GEP of the other element address. 680d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner Value *OtherElt = 0; 681d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (OtherPtr) { 682d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner Value *Idx[2] = { Zero, ConstantInt::get(Type::Int32Ty, i) }; 683d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner OtherElt = GetElementPtrInst::Create(OtherPtr, Idx, Idx + 2, 684963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner OtherPtr->getNameStr()+"."+utostr(i), 685d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner MI); 686d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner } 687d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner 688d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner Value *EltPtr = NewElts[i]; 689d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner const Type *EltTy =cast<PointerType>(EltPtr->getType())->getElementType(); 690d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner 691d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // If we got down to a scalar, insert a load or store as appropriate. 692d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (EltTy->isSingleValueType()) { 693d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (isa<MemCpyInst>(MI) || isa<MemMoveInst>(MI)) { 694d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner Value *Elt = new LoadInst(SROADest ? OtherElt : EltPtr, "tmp", 695d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner MI); 696d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner new StoreInst(Elt, SROADest ? EltPtr : OtherElt, MI); 697d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner continue; 698372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 699d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner assert(isa<MemSetInst>(MI)); 700c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner 701d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // If the stored element is zero (common case), just store a null 702d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // constant. 703d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner Constant *StoreVal; 704d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (ConstantInt *CI = dyn_cast<ConstantInt>(MI->getOperand(2))) { 705d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (CI->isZero()) { 706d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner StoreVal = Constant::getNullValue(EltTy); // 0.0, null, 0, <0,0> 707c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } else { 708d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // If EltTy is a vector type, get the element type. 709d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner const Type *ValTy = EltTy; 710d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (const VectorType *VTy = dyn_cast<VectorType>(ValTy)) 711d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner ValTy = VTy->getElementType(); 712d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner 713d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // Construct an integer with the right value. 714d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner unsigned EltSize = TD->getTypeSizeInBits(ValTy); 715d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner APInt OneVal(EltSize, CI->getZExtValue()); 716d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner APInt TotalVal(OneVal); 717d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // Set each byte. 718d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner for (unsigned i = 0; 8*i < EltSize; ++i) { 719d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner TotalVal = TotalVal.shl(8); 720d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner TotalVal |= OneVal; 721d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner } 722d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner 723d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // Convert the integer value to the appropriate type. 724d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner StoreVal = ConstantInt::get(TotalVal); 725d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (isa<PointerType>(ValTy)) 726d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner StoreVal = ConstantExpr::getIntToPtr(StoreVal, ValTy); 727d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner else if (ValTy->isFloatingPoint()) 728d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner StoreVal = ConstantExpr::getBitCast(StoreVal, ValTy); 729d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner assert(StoreVal->getType() == ValTy && "Type mismatch!"); 730d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner 731d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // If the requested value was a vector constant, create it. 732d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (EltTy != ValTy) { 733d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner unsigned NumElts = cast<VectorType>(ValTy)->getNumElements(); 734d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner SmallVector<Constant*, 16> Elts(NumElts, StoreVal); 735d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner StoreVal = ConstantVector::get(&Elts[0], NumElts); 736c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } 737c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } 738d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner new StoreInst(StoreVal, EltPtr, MI); 739d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner continue; 740c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } 741d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // Otherwise, if we're storing a byte variable, use a memset call for 742d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // this element. 743d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner } 744c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner 745d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // Cast the element pointer to BytePtrTy. 746d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (EltPtr->getType() != BytePtrTy) 747d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner EltPtr = new BitCastInst(EltPtr, BytePtrTy, EltPtr->getNameStr(), MI); 748c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner 749d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // Cast the other pointer (if we have one) to BytePtrTy. 750d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (OtherElt && OtherElt->getType() != BytePtrTy) 751d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner OtherElt = new BitCastInst(OtherElt, BytePtrTy,OtherElt->getNameStr(), 752d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner MI); 753d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner 754d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner unsigned EltSize = TD->getABITypeSize(EltTy); 755d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner 756d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner // Finally, insert the meminst for this element. 757d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner if (isa<MemCpyInst>(MI) || isa<MemMoveInst>(MI)) { 758d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner Value *Ops[] = { 759d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner SROADest ? EltPtr : OtherElt, // Dest ptr 760d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner SROADest ? OtherElt : EltPtr, // Src ptr 761d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner ConstantInt::get(MI->getOperand(3)->getType(), EltSize), // Size 762d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner Zero // Align 763d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner }; 764d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner CallInst::Create(TheFn, Ops, Ops + 4, "", MI); 765d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner } else { 766d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner assert(isa<MemSetInst>(MI)); 767d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner Value *Ops[] = { 768d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner EltPtr, MI->getOperand(2), // Dest, Value, 769d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner ConstantInt::get(MI->getOperand(3)->getType(), EltSize), // Size 770d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner Zero // Align 771d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner }; 772d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner CallInst::Create(TheFn, Ops, Ops + 4, "", MI); 773c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } 774372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 775372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner} 776d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner 777372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 7783cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands/// HasPadding - Return true if the specified type has any structure or 7793cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands/// alignment padding, false otherwise. 780a0fcc08e6542a0376917b5c76a0af3eb2650c535Duncan Sandsstatic bool HasPadding(const Type *Ty, const TargetData &TD) { 78139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (const StructType *STy = dyn_cast<StructType>(Ty)) { 78239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner const StructLayout *SL = TD.getStructLayout(STy); 78339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner unsigned PrevFieldBitOffset = 0; 78439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { 7853cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands unsigned FieldBitOffset = SL->getElementOffsetInBits(i); 7863cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 78739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // Padding in sub-elements? 788a0fcc08e6542a0376917b5c76a0af3eb2650c535Duncan Sands if (HasPadding(STy->getElementType(i), TD)) 78939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return true; 7903cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 79139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // Check to see if there is any padding between this element and the 79239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // previous one. 79339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (i) { 7943cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands unsigned PrevFieldEnd = 79539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner PrevFieldBitOffset+TD.getTypeSizeInBits(STy->getElementType(i-1)); 79639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (PrevFieldEnd < FieldBitOffset) 79739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return true; 79839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 7993cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 80039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner PrevFieldBitOffset = FieldBitOffset; 80139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 8023cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 80339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // Check for tail padding. 80439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (unsigned EltCount = STy->getNumElements()) { 80539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner unsigned PrevFieldEnd = PrevFieldBitOffset + 80639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner TD.getTypeSizeInBits(STy->getElementType(EltCount-1)); 8073cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands if (PrevFieldEnd < SL->getSizeInBits()) 80839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return true; 80939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 81039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 81139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } else if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) { 812a0fcc08e6542a0376917b5c76a0af3eb2650c535Duncan Sands return HasPadding(ATy->getElementType(), TD); 8133cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands } else if (const VectorType *VTy = dyn_cast<VectorType>(Ty)) { 814a0fcc08e6542a0376917b5c76a0af3eb2650c535Duncan Sands return HasPadding(VTy->getElementType(), TD); 81539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 816a0fcc08e6542a0376917b5c76a0af3eb2650c535Duncan Sands return TD.getTypeSizeInBits(Ty) != TD.getABITypeSizeInBits(Ty); 81739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner} 818372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 819f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// isSafeStructAllocaToScalarRepl - Check to see if the specified allocation of 820f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// an aggregate can be broken down into elements. Return 0 if not, 3 if safe, 821f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// or 1 if safe after canonicalization has been performed. 8225e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner/// 823f5990edc877c4e63503c589928a00ec6ec751830Chris Lattnerint SROA::isSafeAllocaToScalarRepl(AllocationInst *AI) { 8245e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner // Loop over the use list of the alloca. We can only transform it if all of 8255e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner // the users are safe to transform. 82639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo Info; 82739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 8285e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner for (Value::use_iterator I = AI->use_begin(), E = AI->use_end(); 829f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner I != E; ++I) { 83039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isSafeUseOfAllocation(cast<Instruction>(*I), AI, Info); 83139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (Info.isUnsafe) { 832b7427031372337e6d67f9573ec6c722ab5ea913eBill Wendling DOUT << "Cannot transform: " << *AI << " due to user: " << **I; 833f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner return 0; 8345e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner } 835f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner } 83639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 83739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // Okay, we know all the users are promotable. If the aggregate is a memcpy 83839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // source and destination, we have to be careful. In particular, the memcpy 83939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // could be moving around elements that live in structure padding of the LLVM 84039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // types, but may actually be used. In these cases, we refuse to promote the 84139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // struct. 84239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (Info.isMemCpySrc && Info.isMemCpyDst && 84356c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner HasPadding(AI->getType()->getElementType(), *TD)) 84439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return 0; 8453cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 84639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // If we require cleanup, return 1, otherwise return 3. 84739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return Info.needsCanon ? 1 : 3; 848f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner} 849f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner 850f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// CanonicalizeAllocaUsers - If SROA reported that it can promote the specified 851f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// allocation, but only if cleaned up, perform the cleanups required. 852f5990edc877c4e63503c589928a00ec6ec751830Chris Lattnervoid SROA::CanonicalizeAllocaUsers(AllocationInst *AI) { 853d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // At this point, we know that the end result will be SROA'd and promoted, so 854d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // we can insert ugly code if required so long as sroa+mem2reg will clean it 855d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // up. 856d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner for (Value::use_iterator UI = AI->use_begin(), E = AI->use_end(); 857d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner UI != E; ) { 858a9d1a843fc74a9d877e105744e710496863f7580Chris Lattner GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(*UI++); 859a9d1a843fc74a9d877e105744e710496863f7580Chris Lattner if (!GEPI) continue; 86096326f9d312585532c95dcc31626f45f16cd5dd8Reid Spencer gep_type_iterator I = gep_type_begin(GEPI); 861d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner ++I; 862d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner 863d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner if (const ArrayType *AT = dyn_cast<ArrayType>(*I)) { 864d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner uint64_t NumElements = AT->getNumElements(); 865fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 866d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner if (!isa<ConstantInt>(I.getOperand())) { 867d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner if (NumElements == 1) { 868c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer GEPI->setOperand(2, Constant::getNullValue(Type::Int32Ty)); 869d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } else { 870d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner assert(NumElements == 2 && "Unhandled case!"); 871d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // All users of the GEP must be loads. At each use of the GEP, insert 872d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // two loads of the appropriate indexed GEP and select between them. 873e4d87aa2de6e52952dca73716386db09aad5a8fdReid Spencer Value *IsOne = new ICmpInst(ICmpInst::ICMP_NE, I.getOperand(), 874d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner Constant::getNullValue(I.getOperand()->getType()), 875e4d87aa2de6e52952dca73716386db09aad5a8fdReid Spencer "isone", GEPI); 876d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // Insert the new GEP instructions, which are properly indexed. 8771ccd185cb49d81465a2901622e58ceae046d1d83Chris Lattner SmallVector<Value*, 8> Indices(GEPI->op_begin()+1, GEPI->op_end()); 878c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer Indices[1] = Constant::getNullValue(Type::Int32Ty); 879051a950000e21935165db56695e35bade668193bGabor Greif Value *ZeroIdx = GetElementPtrInst::Create(GEPI->getOperand(0), 880051a950000e21935165db56695e35bade668193bGabor Greif Indices.begin(), 881051a950000e21935165db56695e35bade668193bGabor Greif Indices.end(), 882051a950000e21935165db56695e35bade668193bGabor Greif GEPI->getName()+".0", GEPI); 883c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer Indices[1] = ConstantInt::get(Type::Int32Ty, 1); 884051a950000e21935165db56695e35bade668193bGabor Greif Value *OneIdx = GetElementPtrInst::Create(GEPI->getOperand(0), 885051a950000e21935165db56695e35bade668193bGabor Greif Indices.begin(), 886051a950000e21935165db56695e35bade668193bGabor Greif Indices.end(), 887051a950000e21935165db56695e35bade668193bGabor Greif GEPI->getName()+".1", GEPI); 888d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // Replace all loads of the variable index GEP with loads from both 889d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // indexes and a select. 890d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner while (!GEPI->use_empty()) { 891d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner LoadInst *LI = cast<LoadInst>(GEPI->use_back()); 892d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner Value *Zero = new LoadInst(ZeroIdx, LI->getName()+".0", LI); 893d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner Value *One = new LoadInst(OneIdx , LI->getName()+".1", LI); 894051a950000e21935165db56695e35bade668193bGabor Greif Value *R = SelectInst::Create(IsOne, One, Zero, LI->getName(), LI); 895d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner LI->replaceAllUsesWith(R); 896d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner LI->eraseFromParent(); 897d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } 898d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner GEPI->eraseFromParent(); 899d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } 900d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } 901d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } 902d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } 9035e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner} 904a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 905a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// MergeInType - Add the 'In' type to the accumulated type so far. If the 906a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// types are incompatible, return true, otherwise update Accum and return 907a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// false. 908de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// 909d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// There are three cases we handle here: 910d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// 1) An effectively-integer union, where the pieces are stored into as 911de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// smaller integers (common with byte swap and other idioms). 912d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// 2) A union of vector types of the same size and potentially its elements. 913d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// Here we turn element accesses into insert/extract element operations. 914d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// 3) A union of scalar types, such as int/float or int/pointer. Here we 915d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// merge together into integers, allowing the xform to work with #1 as 916d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// well. 9175b121cc688eacf41b1b773244882d206199dc105Chris Lattnerstatic bool MergeInType(const Type *In, const Type *&Accum, 9185b121cc688eacf41b1b773244882d206199dc105Chris Lattner const TargetData &TD) { 919a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // If this is our first type, just use it. 9209d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer const VectorType *PTy; 921de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner if (Accum == Type::VoidTy || In == Accum) { 922a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner Accum = In; 923d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner } else if (In == Type::VoidTy) { 924d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // Noop. 92542a75517250017a52afb03a0ade03cbd49559fe5Chris Lattner } else if (In->isInteger() && Accum->isInteger()) { // integer union. 926a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // Otherwise pick whichever type is larger. 927a54b7cbd452b3adb2f51346140d996b29c2cdb30Reid Spencer if (cast<IntegerType>(In)->getBitWidth() > 928a54b7cbd452b3adb2f51346140d996b29c2cdb30Reid Spencer cast<IntegerType>(Accum)->getBitWidth()) 929a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner Accum = In; 9305b121cc688eacf41b1b773244882d206199dc105Chris Lattner } else if (isa<PointerType>(In) && isa<PointerType>(Accum)) { 931c836333c3b0a18c398436ae00667a8fb5e476129Chris Lattner // Pointer unions just stay as one of the pointers. 9329d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer } else if (isa<VectorType>(In) || isa<VectorType>(Accum)) { 9339d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer if ((PTy = dyn_cast<VectorType>(Accum)) && 934d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner PTy->getElementType() == In) { 935d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // Accum is a vector, and we are accessing an element: ok. 9369d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer } else if ((PTy = dyn_cast<VectorType>(In)) && 937d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner PTy->getElementType() == Accum) { 938d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // In is a vector, and accum is an element: ok, remember In. 939d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner Accum = In; 9409d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer } else if ((PTy = dyn_cast<VectorType>(In)) && isa<VectorType>(Accum) && 9419d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer PTy->getBitWidth() == cast<VectorType>(Accum)->getBitWidth()) { 942d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // Two vectors of the same size: keep Accum. 943d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner } else { 944d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // Cannot insert an short into a <4 x int> or handle 945d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // <2 x int> -> <4 x int> 946d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner return true; 947d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner } 94821c362d3240d0ba9ff98b7f36e54f25936d1a201Chris Lattner } else { 949d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // Pointer/FP/Integer unions merge together as integers. 950d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner switch (Accum->getTypeID()) { 951d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner case Type::PointerTyID: Accum = TD.getIntPtrType(); break; 952c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer case Type::FloatTyID: Accum = Type::Int32Ty; break; 953c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer case Type::DoubleTyID: Accum = Type::Int64Ty; break; 954ef0ab932ef3b07016ffb827cd529d4787d7ed12eDale Johannesen case Type::X86_FP80TyID: return true; 955ef0ab932ef3b07016ffb827cd529d4787d7ed12eDale Johannesen case Type::FP128TyID: return true; 956ef0ab932ef3b07016ffb827cd529d4787d7ed12eDale Johannesen case Type::PPC_FP128TyID: return true; 957d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner default: 95842a75517250017a52afb03a0ade03cbd49559fe5Chris Lattner assert(Accum->isInteger() && "Unknown FP type!"); 959d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner break; 960d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner } 961d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner 962d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner switch (In->getTypeID()) { 963d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner case Type::PointerTyID: In = TD.getIntPtrType(); break; 964c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer case Type::FloatTyID: In = Type::Int32Ty; break; 965c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer case Type::DoubleTyID: In = Type::Int64Ty; break; 966ef0ab932ef3b07016ffb827cd529d4787d7ed12eDale Johannesen case Type::X86_FP80TyID: return true; 967ef0ab932ef3b07016ffb827cd529d4787d7ed12eDale Johannesen case Type::FP128TyID: return true; 968ef0ab932ef3b07016ffb827cd529d4787d7ed12eDale Johannesen case Type::PPC_FP128TyID: return true; 969d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner default: 97042a75517250017a52afb03a0ade03cbd49559fe5Chris Lattner assert(In->isInteger() && "Unknown FP type!"); 971d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner break; 972d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner } 973d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner return MergeInType(In, Accum, TD); 974a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 975a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return false; 976a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner} 977a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 97856c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner/// getIntAtLeastAsBigAs - Return an integer type that is at least as big as the 97956c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner/// specified type. If there is no suitable type, this returns null. 98056c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattnerconst Type *getIntAtLeastAsBigAs(unsigned NumBits) { 981a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (NumBits > 64) return 0; 982c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer if (NumBits > 32) return Type::Int64Ty; 983c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer if (NumBits > 16) return Type::Int32Ty; 984c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer if (NumBits > 8) return Type::Int16Ty; 985c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer return Type::Int8Ty; 986a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner} 987a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 988a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// CanConvertToScalar - V is a pointer. If we can convert the pointee to a 989a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// single scalar integer type, return that type. Further, if the use is not 990a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// a completely trivial use that mem2reg could promote, set IsNotTrivial. If 991a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// there are no uses of this pointer, return Type::VoidTy to differentiate from 992a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// failure. 993a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// 994a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattnerconst Type *SROA::CanConvertToScalar(Value *V, bool &IsNotTrivial) { 995a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *UsedType = Type::VoidTy; // No uses, no forced type. 996a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const PointerType *PTy = cast<PointerType>(V->getType()); 997a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 998a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI!=E; ++UI) { 999a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner Instruction *User = cast<Instruction>(*UI); 1000a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1001a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(User)) { 100202518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman // FIXME: Loads of a first class aggregrate value could be converted to a 100302518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman // series of loads and insertvalues 100402518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman if (!LI->getType()->isSingleValueType()) 100502518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman return 0; 100602518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman 100756c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner if (MergeInType(LI->getType(), UsedType, *TD)) 1008a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return 0; 1009cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner continue; 1010cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner } 1011cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner 1012cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner if (StoreInst *SI = dyn_cast<StoreInst>(User)) { 101324d6da5fedcf39891f7d8c5b031c01324b3db545Reid Spencer // Storing the pointer, not into the value? 1014a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (SI->getOperand(0) == V) return 0; 101502518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman 101602518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman // FIXME: Stores of a first class aggregrate value could be converted to a 101702518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman // series of extractvalues and stores 101802518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman if (!SI->getOperand(0)->getType()->isSingleValueType()) 101902518140ac3310d0357c26a87b2372d85da9c2f4Matthijs Kooijman return 0; 1020a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1021de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner // NOTE: We could handle storing of FP imms into integers here! 1022a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 102356c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner if (MergeInType(SI->getOperand(0)->getType(), UsedType, *TD)) 1024a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return 0; 1025cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner continue; 1026cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner } 1027cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner if (BitCastInst *CI = dyn_cast<BitCastInst>(User)) { 1028a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner IsNotTrivial = true; 1029a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *SubTy = CanConvertToScalar(CI, IsNotTrivial); 103056c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner if (!SubTy || MergeInType(SubTy, UsedType, *TD)) return 0; 1031cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner continue; 1032cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner } 1033cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner 1034cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(User)) { 1035a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // Check to see if this is stepping over an element: GEP Ptr, int C 1036a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (GEP->getNumOperands() == 2 && isa<ConstantInt>(GEP->getOperand(1))) { 1037b83eb6447ba155342598f0fabe1f08f5baa9164aReid Spencer unsigned Idx = cast<ConstantInt>(GEP->getOperand(1))->getZExtValue(); 103856c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner unsigned ElSize = TD->getABITypeSize(PTy->getElementType()); 1039a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner unsigned BitOffset = Idx*ElSize*8; 1040a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (BitOffset > 64 || !isPowerOf2_32(ElSize)) return 0; 1041a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1042a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner IsNotTrivial = true; 1043a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *SubElt = CanConvertToScalar(GEP, IsNotTrivial); 1044a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (SubElt == 0) return 0; 104542a75517250017a52afb03a0ade03cbd49559fe5Chris Lattner if (SubElt != Type::VoidTy && SubElt->isInteger()) { 1046a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *NewTy = 104756c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner getIntAtLeastAsBigAs(TD->getABITypeSizeInBits(SubElt)+BitOffset); 104856c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner if (NewTy == 0 || MergeInType(NewTy, UsedType, *TD)) return 0; 1049a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner continue; 1050a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1051cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner // Cannot handle this! 1052cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner return 0; 1053cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner } 1054cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner 1055cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner if (GEP->getNumOperands() == 3 && 1056cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner isa<ConstantInt>(GEP->getOperand(1)) && 1057cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner isa<ConstantInt>(GEP->getOperand(2)) && 1058cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner cast<ConstantInt>(GEP->getOperand(1))->isZero()) { 1059a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // We are stepping into an element, e.g. a structure or an array: 1060d356a7ee0ed7744857dcf497cb20b0128770fb0fChris Lattner // GEP Ptr, i32 0, i32 Cst 1061a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *AggTy = PTy->getElementType(); 1062b83eb6447ba155342598f0fabe1f08f5baa9164aReid Spencer unsigned Idx = cast<ConstantInt>(GEP->getOperand(2))->getZExtValue(); 1063a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1064a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (const ArrayType *ATy = dyn_cast<ArrayType>(AggTy)) { 1065a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (Idx >= ATy->getNumElements()) return 0; // Out of range. 1066ac9dcb94dde5f166ee29372385c0e3b695227ab4Reid Spencer } else if (const VectorType *VectorTy = dyn_cast<VectorType>(AggTy)) { 106707a96765daedf180a7102d39fe56c499878312b7Dan Gohman // Getting an element of the vector. 1068ac9dcb94dde5f166ee29372385c0e3b695227ab4Reid Spencer if (Idx >= VectorTy->getNumElements()) return 0; // Out of range. 1069de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner 1070ac9dcb94dde5f166ee29372385c0e3b695227ab4Reid Spencer // Merge in the vector type. 107156c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner if (MergeInType(VectorTy, UsedType, *TD)) return 0; 1072de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner 1073de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner const Type *SubTy = CanConvertToScalar(GEP, IsNotTrivial); 1074de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner if (SubTy == 0) return 0; 1075de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner 107656c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner if (SubTy != Type::VoidTy && MergeInType(SubTy, UsedType, *TD)) 1077de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner return 0; 1078de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner 1079de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner // We'll need to change this to an insert/extract element operation. 1080de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner IsNotTrivial = true; 1081de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner continue; // Everything looks ok 1082de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner 1083a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else if (isa<StructType>(AggTy)) { 1084a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // Structs are always ok. 1085a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else { 1086a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return 0; 1087a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 108856c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner const Type *NTy = getIntAtLeastAsBigAs(TD->getABITypeSizeInBits(AggTy)); 108956c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner if (NTy == 0 || MergeInType(NTy, UsedType, *TD)) return 0; 1090a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *SubTy = CanConvertToScalar(GEP, IsNotTrivial); 1091a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (SubTy == 0) return 0; 109256c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner if (SubTy != Type::VoidTy && MergeInType(SubTy, UsedType, *TD)) 1093a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return 0; 1094a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner continue; // Everything looks ok 1095a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1096a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return 0; 1097a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1098cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner 1099cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner // Cannot handle this! 1100cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner return 0; 1101a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1102a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1103a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return UsedType; 1104a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner} 1105a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1106a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// ConvertToScalar - The specified alloca passes the CanConvertToScalar 1107a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// predicate and is non-trivial. Convert it to something that can be trivially 1108a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// promoted into a register by mem2reg. 1109a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattnervoid SROA::ConvertToScalar(AllocationInst *AI, const Type *ActualTy) { 1110b7427031372337e6d67f9573ec6c722ab5ea913eBill Wendling DOUT << "CONVERT TO SCALAR: " << *AI << " TYPE = " 1111b7427031372337e6d67f9573ec6c722ab5ea913eBill Wendling << *ActualTy << "\n"; 1112a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner ++NumConverted; 1113a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1114a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner BasicBlock *EntryBlock = AI->getParent(); 1115ecb7a77885b174cf4d001a9b48533b3979e7810dDan Gohman assert(EntryBlock == &EntryBlock->getParent()->getEntryBlock() && 1116a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner "Not in the entry block!"); 1117a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner EntryBlock->getInstList().remove(AI); // Take the alloca out of the program. 1118a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1119a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // Create and insert the alloca. 1120de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner AllocaInst *NewAI = new AllocaInst(ActualTy, 0, AI->getName(), 1121de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner EntryBlock->begin()); 1122a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner ConvertUsesToScalar(AI, NewAI, 0); 1123a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner delete AI; 1124a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner} 1125a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1126a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1127a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// ConvertUsesToScalar - Convert all of the users of Ptr to use the new alloca 1128de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// directly. This happens when we are converting an "integer union" to a 1129de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// single integer scalar, or when we are converting a "vector union" to a 1130de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// vector with insert/extractelement instructions. 1131de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// 1132de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// Offset is an offset from the original alloca, in bits that need to be 1133de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// shifted to the right. By the end of this, there should be no uses of Ptr. 1134a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattnervoid SROA::ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI, unsigned Offset) { 1135a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner while (!Ptr->use_empty()) { 1136a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner Instruction *User = cast<Instruction>(Ptr->use_back()); 1137a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1138a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(User)) { 1139800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *NV = ConvertUsesOfLoadToScalar(LI, NewAI, Offset); 1140a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner LI->replaceAllUsesWith(NV); 1141a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner LI->eraseFromParent(); 1142cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner continue; 1143cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner } 1144cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner 1145cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner if (StoreInst *SI = dyn_cast<StoreInst>(User)) { 1146a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner assert(SI->getOperand(0) != Ptr && "Consistency error!"); 1147a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1148800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *SV = ConvertUsesOfStoreToScalar(SI, NewAI, Offset); 1149a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner new StoreInst(SV, NewAI, SI); 1150a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner SI->eraseFromParent(); 1151cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner continue; 1152cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner } 1153cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner 1154cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner if (BitCastInst *CI = dyn_cast<BitCastInst>(User)) { 1155b10e0da065fc2c18b5bee9011eb249e223a23108Chris Lattner ConvertUsesToScalar(CI, NewAI, Offset); 1156a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner CI->eraseFromParent(); 1157cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner continue; 1158cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner } 1159cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner 1160cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(User)) { 1161a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const PointerType *AggPtrTy = 1162a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner cast<PointerType>(GEP->getOperand(0)->getType()); 11633cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands unsigned AggSizeInBits = 116456c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner TD->getABITypeSizeInBits(AggPtrTy->getElementType()); 11653cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 1166a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // Check to see if this is stepping over an element: GEP Ptr, int C 1167a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner unsigned NewOffset = Offset; 1168a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (GEP->getNumOperands() == 2) { 1169b83eb6447ba155342598f0fabe1f08f5baa9164aReid Spencer unsigned Idx = cast<ConstantInt>(GEP->getOperand(1))->getZExtValue(); 1170a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner unsigned BitOffset = Idx*AggSizeInBits; 1171a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1172f4b1818728fb5cb0740cf5362faf72dd66ccf3eaChris Lattner NewOffset += BitOffset; 1173cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner ConvertUsesToScalar(GEP, NewAI, NewOffset); 1174cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner GEP->eraseFromParent(); 1175cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner continue; 1176cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner } 1177cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner 1178cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner assert(GEP->getNumOperands() == 3 && "Unsupported operation"); 1179cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner 1180cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner // We know that operand #2 is zero. 1181cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner unsigned Idx = cast<ConstantInt>(GEP->getOperand(2))->getZExtValue(); 1182cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner const Type *AggTy = AggPtrTy->getElementType(); 1183cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner if (const SequentialType *SeqTy = dyn_cast<SequentialType>(AggTy)) { 1184cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner unsigned ElSizeBits = 1185cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner TD->getABITypeSizeInBits(SeqTy->getElementType()); 1186cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner 1187cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner NewOffset += ElSizeBits*Idx; 1188a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else { 1189cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner const StructType *STy = cast<StructType>(AggTy); 1190cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner unsigned EltBitOffset = 1191cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner TD->getStructLayout(STy)->getElementOffsetInBits(Idx); 1192cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner 1193cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner NewOffset += EltBitOffset; 1194a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1195a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner ConvertUsesToScalar(GEP, NewAI, NewOffset); 1196a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner GEP->eraseFromParent(); 1197cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner continue; 1198a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1199cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner 1200cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner assert(0 && "Unsupported operation!"); 1201cf3218640969175634b82e4e3fde1b9e680a5dc6Chris Lattner abort(); 1202a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1203a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner} 120479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 1205800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// ConvertUsesOfLoadToScalar - Convert all of the users the specified load to 1206800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// use the new alloca directly, returning the value that should replace the 1207800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// load. This happens when we are converting an "integer union" to a 1208800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// single integer scalar, or when we are converting a "vector union" to a 1209800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// vector with insert/extractelement instructions. 1210800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// 1211800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// Offset is an offset from the original alloca, in bits that need to be 1212800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// shifted to the right. By the end of this, there should be no uses of Ptr. 1213800de31776356910eb877e71df9f32b0a6215324Chris LattnerValue *SROA::ConvertUsesOfLoadToScalar(LoadInst *LI, AllocaInst *NewAI, 1214800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned Offset) { 1215800de31776356910eb877e71df9f32b0a6215324Chris Lattner // The load is a bit extract from NewAI shifted right by Offset bits. 1216800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *NV = new LoadInst(NewAI, LI->getName(), LI); 1217800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1218800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (NV->getType() == LI->getType() && Offset == 0) { 1219800de31776356910eb877e71df9f32b0a6215324Chris Lattner // We win, no conversion needed. 1220800de31776356910eb877e71df9f32b0a6215324Chris Lattner return NV; 1221800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 12229d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner 12239d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // If the result type of the 'union' is a pointer, then this must be ptr->ptr 12249d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // cast. Anything else would result in NV being an integer. 12259d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner if (isa<PointerType>(NV->getType())) { 12269d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner assert(isa<PointerType>(LI->getType())); 12279d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner return new BitCastInst(NV, LI->getType(), LI->getName(), LI); 12289d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner } 1229800de31776356910eb877e71df9f32b0a6215324Chris Lattner 12309d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner if (const VectorType *VTy = dyn_cast<VectorType>(NV->getType())) { 1231800de31776356910eb877e71df9f32b0a6215324Chris Lattner // If the result alloca is a vector type, this is either an element 1232800de31776356910eb877e71df9f32b0a6215324Chris Lattner // access or a bitcast to another vector type. 12339d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner if (isa<VectorType>(LI->getType())) 12349d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner return new BitCastInst(NV, LI->getType(), LI->getName(), LI); 12359d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner 12369d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // Otherwise it must be an element access. 12379d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner unsigned Elt = 0; 12389d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner if (Offset) { 123956c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner unsigned EltSize = TD->getABITypeSizeInBits(VTy->getElementType()); 12409d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner Elt = Offset/EltSize; 12419d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner Offset -= EltSize*Elt; 1242800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 12439d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner NV = new ExtractElementInst(NV, ConstantInt::get(Type::Int32Ty, Elt), 12449d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner "tmp", LI); 1245800de31776356910eb877e71df9f32b0a6215324Chris Lattner 12469d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // If we're done, return this element. 12479d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner if (NV->getType() == LI->getType() && Offset == 0) 12489d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner return NV; 12499d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner } 12509d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner 12519d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner const IntegerType *NTy = cast<IntegerType>(NV->getType()); 12529d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner 12539d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // If this is a big-endian system and the load is narrower than the 12549d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // full alloca type, we need to do a shift to get the right bits. 12559d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner int ShAmt = 0; 125656c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner if (TD->isBigEndian()) { 12579d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // On big-endian machines, the lowest bit is stored at the bit offset 12589d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // from the pointer given by getTypeStoreSizeInBits. This matters for 12599d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // integers with a bitwidth that is not a multiple of 8. 126056c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner ShAmt = TD->getTypeStoreSizeInBits(NTy) - 126156c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner TD->getTypeStoreSizeInBits(LI->getType()) - Offset; 12629d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner } else { 12639d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner ShAmt = Offset; 12649d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner } 12659d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner 12669d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // Note: we support negative bitwidths (with shl) which are not defined. 12679d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // We do this to support (f.e.) loads off the end of a structure where 12689d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // only some bits are used. 12699d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner if (ShAmt > 0 && (unsigned)ShAmt < NTy->getBitWidth()) 12707cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif NV = BinaryOperator::CreateLShr(NV, 12719d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner ConstantInt::get(NV->getType(),ShAmt), 12729d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner LI->getName(), LI); 12739d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner else if (ShAmt < 0 && (unsigned)-ShAmt < NTy->getBitWidth()) 12747cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif NV = BinaryOperator::CreateShl(NV, 12759d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner ConstantInt::get(NV->getType(),-ShAmt), 12769d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner LI->getName(), LI); 12779d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner 12789d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // Finally, unconditionally truncate the integer to the right width. 127956c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner unsigned LIBitWidth = TD->getTypeSizeInBits(LI->getType()); 12809d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner if (LIBitWidth < NTy->getBitWidth()) 12819d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner NV = new TruncInst(NV, IntegerType::get(LIBitWidth), 12829d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner LI->getName(), LI); 12839d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner 12849d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // If the result is an integer, this is a trunc or bitcast. 12859d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner if (isa<IntegerType>(LI->getType())) { 12869d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // Should be done. 12879d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner } else if (LI->getType()->isFloatingPoint()) { 12889d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // Just do a bitcast, we know the sizes match up. 12899d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner NV = new BitCastInst(NV, LI->getType(), LI->getName(), LI); 12909d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner } else { 12919d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner // Otherwise must be a pointer. 12929d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner NV = new IntToPtrInst(NV, LI->getType(), LI->getName(), LI); 1293800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 12949d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner assert(NV->getType() == LI->getType() && "Didn't convert right?"); 1295800de31776356910eb877e71df9f32b0a6215324Chris Lattner return NV; 1296800de31776356910eb877e71df9f32b0a6215324Chris Lattner} 1297800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1298800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1299800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// ConvertUsesOfStoreToScalar - Convert the specified store to a load+store 1300800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// pair of the new alloca directly, returning the value that should be stored 1301800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// to the alloca. This happens when we are converting an "integer union" to a 1302800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// single integer scalar, or when we are converting a "vector union" to a 1303800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// vector with insert/extractelement instructions. 1304800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// 1305800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// Offset is an offset from the original alloca, in bits that need to be 1306800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// shifted to the right. By the end of this, there should be no uses of Ptr. 1307800de31776356910eb877e71df9f32b0a6215324Chris LattnerValue *SROA::ConvertUsesOfStoreToScalar(StoreInst *SI, AllocaInst *NewAI, 1308800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned Offset) { 1309800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1310800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Convert the stored type to the actual type, shift it left to insert 1311800de31776356910eb877e71df9f32b0a6215324Chris Lattner // then 'or' into place. 1312800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *SV = SI->getOperand(0); 1313800de31776356910eb877e71df9f32b0a6215324Chris Lattner const Type *AllocaType = NewAI->getType()->getElementType(); 1314800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (SV->getType() == AllocaType && Offset == 0) { 1315800de31776356910eb877e71df9f32b0a6215324Chris Lattner // All is well. 1316800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else if (const VectorType *PTy = dyn_cast<VectorType>(AllocaType)) { 1317800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *Old = new LoadInst(NewAI, NewAI->getName()+".in", SI); 1318800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1319800de31776356910eb877e71df9f32b0a6215324Chris Lattner // If the result alloca is a vector type, this is either an element 1320800de31776356910eb877e71df9f32b0a6215324Chris Lattner // access or a bitcast to another vector type. 1321800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (isa<VectorType>(SV->getType())) { 1322800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV = new BitCastInst(SV, AllocaType, SV->getName(), SI); 1323800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else { 1324800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Must be an element insertion. 132556c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner unsigned Elt = Offset/TD->getABITypeSizeInBits(PTy->getElementType()); 1326051a950000e21935165db56695e35bade668193bGabor Greif SV = InsertElementInst::Create(Old, SV, 1327051a950000e21935165db56695e35bade668193bGabor Greif ConstantInt::get(Type::Int32Ty, Elt), 1328051a950000e21935165db56695e35bade668193bGabor Greif "tmp", SI); 1329800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 1330800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else if (isa<PointerType>(AllocaType)) { 1331800de31776356910eb877e71df9f32b0a6215324Chris Lattner // If the alloca type is a pointer, then all the elements must be 1332800de31776356910eb877e71df9f32b0a6215324Chris Lattner // pointers. 1333800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (SV->getType() != AllocaType) 1334800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV = new BitCastInst(SV, AllocaType, SV->getName(), SI); 1335800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else { 1336800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *Old = new LoadInst(NewAI, NewAI->getName()+".in", SI); 1337800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1338800de31776356910eb877e71df9f32b0a6215324Chris Lattner // If SV is a float, convert it to the appropriate integer type. 1339800de31776356910eb877e71df9f32b0a6215324Chris Lattner // If it is a pointer, do the same, and also handle ptr->ptr casts 1340800de31776356910eb877e71df9f32b0a6215324Chris Lattner // here. 134156c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner unsigned SrcWidth = TD->getTypeSizeInBits(SV->getType()); 134256c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner unsigned DestWidth = TD->getTypeSizeInBits(AllocaType); 134356c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner unsigned SrcStoreWidth = TD->getTypeStoreSizeInBits(SV->getType()); 134456c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner unsigned DestStoreWidth = TD->getTypeStoreSizeInBits(AllocaType); 1345800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (SV->getType()->isFloatingPoint()) 1346800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV = new BitCastInst(SV, IntegerType::get(SrcWidth), 1347800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV->getName(), SI); 1348800de31776356910eb877e71df9f32b0a6215324Chris Lattner else if (isa<PointerType>(SV->getType())) 134956c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner SV = new PtrToIntInst(SV, TD->getIntPtrType(), SV->getName(), SI); 1350800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1351800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Always zero extend the value if needed. 1352800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (SV->getType() != AllocaType) 1353800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV = new ZExtInst(SV, AllocaType, SV->getName(), SI); 1354800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1355800de31776356910eb877e71df9f32b0a6215324Chris Lattner // If this is a big-endian system and the store is narrower than the 1356800de31776356910eb877e71df9f32b0a6215324Chris Lattner // full alloca type, we need to do a shift to get the right bits. 1357800de31776356910eb877e71df9f32b0a6215324Chris Lattner int ShAmt = 0; 135856c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner if (TD->isBigEndian()) { 1359800de31776356910eb877e71df9f32b0a6215324Chris Lattner // On big-endian machines, the lowest bit is stored at the bit offset 1360800de31776356910eb877e71df9f32b0a6215324Chris Lattner // from the pointer given by getTypeStoreSizeInBits. This matters for 1361800de31776356910eb877e71df9f32b0a6215324Chris Lattner // integers with a bitwidth that is not a multiple of 8. 1362800de31776356910eb877e71df9f32b0a6215324Chris Lattner ShAmt = DestStoreWidth - SrcStoreWidth - Offset; 1363800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else { 1364800de31776356910eb877e71df9f32b0a6215324Chris Lattner ShAmt = Offset; 1365800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 1366800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1367800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Note: we support negative bitwidths (with shr) which are not defined. 1368800de31776356910eb877e71df9f32b0a6215324Chris Lattner // We do this to support (f.e.) stores off the end of a structure where 1369800de31776356910eb877e71df9f32b0a6215324Chris Lattner // only some bits in the structure are set. 1370800de31776356910eb877e71df9f32b0a6215324Chris Lattner APInt Mask(APInt::getLowBitsSet(DestWidth, SrcWidth)); 1371800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (ShAmt > 0 && (unsigned)ShAmt < DestWidth) { 13727cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif SV = BinaryOperator::CreateShl(SV, 1373800de31776356910eb877e71df9f32b0a6215324Chris Lattner ConstantInt::get(SV->getType(), ShAmt), 1374800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV->getName(), SI); 1375800de31776356910eb877e71df9f32b0a6215324Chris Lattner Mask <<= ShAmt; 1376800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else if (ShAmt < 0 && (unsigned)-ShAmt < DestWidth) { 13777cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif SV = BinaryOperator::CreateLShr(SV, 1378800de31776356910eb877e71df9f32b0a6215324Chris Lattner ConstantInt::get(SV->getType(),-ShAmt), 1379800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV->getName(), SI); 1380800de31776356910eb877e71df9f32b0a6215324Chris Lattner Mask = Mask.lshr(ShAmt); 1381800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 1382800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1383800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Mask out the bits we are about to insert from the old value, and or 1384800de31776356910eb877e71df9f32b0a6215324Chris Lattner // in the new bits. 1385800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (SrcWidth != DestWidth) { 1386800de31776356910eb877e71df9f32b0a6215324Chris Lattner assert(DestWidth > SrcWidth); 13877cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif Old = BinaryOperator::CreateAnd(Old, ConstantInt::get(~Mask), 1388800de31776356910eb877e71df9f32b0a6215324Chris Lattner Old->getName()+".mask", SI); 13897cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif SV = BinaryOperator::CreateOr(Old, SV, SV->getName()+".ins", SI); 1390800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 1391800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 1392800de31776356910eb877e71df9f32b0a6215324Chris Lattner return SV; 1393800de31776356910eb877e71df9f32b0a6215324Chris Lattner} 1394800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1395800de31776356910eb877e71df9f32b0a6215324Chris Lattner 139679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 139779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// PointsToConstantGlobal - Return true if V (possibly indirectly) points to 139879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// some part of a constant global variable. This intentionally only accepts 139979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// constant expressions because we don't can't rewrite arbitrary instructions. 140079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattnerstatic bool PointsToConstantGlobal(Value *V) { 140179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) 140279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return GV->isConstant(); 140379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) 140479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (CE->getOpcode() == Instruction::BitCast || 140579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner CE->getOpcode() == Instruction::GetElementPtr) 140679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return PointsToConstantGlobal(CE->getOperand(0)); 140779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return false; 140879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner} 140979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 141079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// isOnlyCopiedFromConstantGlobal - Recursively walk the uses of a (derived) 141179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// pointer to an alloca. Ignore any reads of the pointer, return false if we 141279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// see any stores or other unknown uses. If we see pointer arithmetic, keep 141379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// track of whether it moves the pointer (with isOffset) but otherwise traverse 141479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// the uses. If we see a memcpy/memmove that targets an unoffseted pointer to 141579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// the alloca, and if the source pointer is a pointer to a constant global, we 141679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// can optimize this. 141779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattnerstatic bool isOnlyCopiedFromConstantGlobal(Value *V, Instruction *&TheCopy, 141879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner bool isOffset) { 141979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI!=E; ++UI) { 142079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (isa<LoadInst>(*UI)) { 142179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // Ignore loads, they are always ok. 142279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner continue; 142379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner } 142479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (BitCastInst *BCI = dyn_cast<BitCastInst>(*UI)) { 142579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If uses of the bitcast are ok, we are ok. 142679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (!isOnlyCopiedFromConstantGlobal(BCI, TheCopy, isOffset)) 142779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return false; 142879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner continue; 142979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner } 143079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(*UI)) { 143179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If the GEP has all zero indices, it doesn't offset the pointer. If it 143279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // doesn't, it does. 143379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (!isOnlyCopiedFromConstantGlobal(GEP, TheCopy, 143479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner isOffset || !GEP->hasAllZeroIndices())) 143579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return false; 143679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner continue; 143779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner } 143879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 143979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If this is isn't our memcpy/memmove, reject it as something we can't 144079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // handle. 144179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (!isa<MemCpyInst>(*UI) && !isa<MemMoveInst>(*UI)) 144279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return false; 144379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 144479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If we already have seen a copy, reject the second one. 144579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (TheCopy) return false; 144679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 144779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If the pointer has been offset from the start of the alloca, we can't 144879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // safely handle this. 144979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (isOffset) return false; 145079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 145179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If the memintrinsic isn't using the alloca as the dest, reject it. 145279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (UI.getOperandNo() != 1) return false; 145379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 145479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner MemIntrinsic *MI = cast<MemIntrinsic>(*UI); 145579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 145679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If the source of the memcpy/move is not a constant global, reject it. 145779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (!PointsToConstantGlobal(MI->getOperand(2))) 145879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return false; 145979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 146079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // Otherwise, the transform is safe. Remember the copy instruction. 146179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner TheCopy = MI; 146279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner } 146379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return true; 146479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner} 146579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 146679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// isOnlyCopiedFromConstantGlobal - Return true if the specified alloca is only 146779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// modified by a copy from a constant global. If we can prove this, we can 146879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// replace any uses of the alloca with uses of the global directly. 146979b3bd395dc3303cde65e18e0524ed2f70268c99Chris LattnerInstruction *SROA::isOnlyCopiedFromConstantGlobal(AllocationInst *AI) { 147079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner Instruction *TheCopy = 0; 147179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (::isOnlyCopiedFromConstantGlobal(AI, TheCopy, false)) 147279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return TheCopy; 147379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return 0; 147479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner} 1475