ScalarReplAggregates.cpp revision dd68912801861273dc3dca33cfc18357213049a4
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" 30fa5cbd6d0fbda23fd669c8718e07b19001b2d21aOwen Anderson#include "llvm/LLVMContext.h" 3172eaa0e5eb345a8483608675b86dfcfa465c784cChris Lattner#include "llvm/Module.h" 32372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner#include "llvm/Pass.h" 33c827939046670a9800659b83e2048f1d3a79a531Cameron Zwarich#include "llvm/Analysis/DIBuilder.h" 34b1686c32fc694636cbf15a59b23b2a741b65ecf4Cameron Zwarich#include "llvm/Analysis/Dominators.h" 35c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner#include "llvm/Analysis/Loads.h" 365034dd318a9dfa0dc45a3ac01e58e60f2aa2498dDan Gohman#include "llvm/Analysis/ValueTracking.h" 3738aec325604635380421a27e39ab06d55ed2458dChris Lattner#include "llvm/Target/TargetData.h" 3838aec325604635380421a27e39ab06d55ed2458dChris Lattner#include "llvm/Transforms/Utils/PromoteMemToReg.h" 394afc90dacf309999d8b7f6c2b4b0c56af346bab5Devang Patel#include "llvm/Transforms/Utils/Local.h" 40e0a1a5ba91df6817f9ffae7af65ed0bda66f7620Chris Lattner#include "llvm/Transforms/Utils/SSAUpdater.h" 41a9be1df6d7a9b5a07253d83a634ae5876e7e5550Chris Lattner#include "llvm/Support/CallSite.h" 429525528a7dc5462b6374d38c81ba5c07b11741feChris Lattner#include "llvm/Support/Debug.h" 437d696d80409aad20bb5da0fc4eccab941dd371d4Torok Edwin#include "llvm/Support/ErrorHandling.h" 44a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner#include "llvm/Support/GetElementPtrTypeIterator.h" 4565a650291d01638853aaf1e80fcc2fc86a785957Chris Lattner#include "llvm/Support/IRBuilder.h" 46a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner#include "llvm/Support/MathExtras.h" 47bdff548e4dd577a72094d57b282de4e765643b96Chris Lattner#include "llvm/Support/raw_ostream.h" 48c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner#include "llvm/ADT/SetVector.h" 491ccd185cb49d81465a2901622e58ceae046d1d83Chris Lattner#include "llvm/ADT/SmallVector.h" 50551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/Statistic.h" 51d8664730942beb911327336d1f9db8e7efcd6813Chris Lattnerusing namespace llvm; 52d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 530e5f499638c8d277b9dc4a4385712177c53b5681Chris LattnerSTATISTIC(NumReplaced, "Number of allocas broken up"); 540e5f499638c8d277b9dc4a4385712177c53b5681Chris LattnerSTATISTIC(NumPromoted, "Number of allocas promoted"); 55c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris LattnerSTATISTIC(NumAdjusted, "Number of scalar allocas adjusted to allow promotion"); 560e5f499638c8d277b9dc4a4385712177c53b5681Chris LattnerSTATISTIC(NumConverted, "Number of aggregates converted to scalar"); 5779b3bd395dc3303cde65e18e0524ed2f70268c99Chris LattnerSTATISTIC(NumGlobals, "Number of allocas copied from constant global"); 58ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 590e5f499638c8d277b9dc4a4385712177c53b5681Chris Lattnernamespace { 603e8b6631e67e01e4960a7ba4668a50c596607473Chris Lattner struct SROA : public FunctionPass { 61b1686c32fc694636cbf15a59b23b2a741b65ecf4Cameron Zwarich SROA(int T, bool hasDT, char &ID) 62b1686c32fc694636cbf15a59b23b2a741b65ecf4Cameron Zwarich : FunctionPass(ID), HasDomTree(hasDT) { 63ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel if (T == -1) 64b0e71edb6b33f822e001500dac90acf95faacea8Chris Lattner SRThreshold = 128; 65ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel else 66ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel SRThreshold = T; 67ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel } 68794fd75c67a2cdc128d67342c6d88a504d186896Devang Patel 69ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner bool runOnFunction(Function &F); 70ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 7138aec325604635380421a27e39ab06d55ed2458dChris Lattner bool performScalarRepl(Function &F); 7238aec325604635380421a27e39ab06d55ed2458dChris Lattner bool performPromotion(Function &F); 7338aec325604635380421a27e39ab06d55ed2458dChris Lattner 74ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner private: 75b1686c32fc694636cbf15a59b23b2a741b65ecf4Cameron Zwarich bool HasDomTree; 7656c3852fb46b7754ad89b998b5968cff0c3937eeChris Lattner TargetData *TD; 776974302e3ff20746268721959efed807c7711bfcBob Wilson 78b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson /// DeadInsts - Keep track of instructions we have made dead, so that 79b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson /// we can remove them after we are done working. 80b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson SmallVector<Value*, 32> DeadInsts; 81b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson 8239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// AllocaInfo - When analyzing uses of an alloca instruction, this captures 8339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// information about the uses. All these fields are initialized to false 8439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// and set to true when something is learned. 8539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner struct AllocaInfo { 866c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattner /// The alloca to promote. 876c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattner AllocaInst *AI; 886c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattner 89145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner /// CheckedPHIs - This is a set of verified PHI nodes, to prevent infinite 90145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner /// looping and avoid redundant work. 91145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner SmallPtrSet<PHINode*, 8> CheckedPHIs; 92145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner 9339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// isUnsafe - This is set to true if the alloca cannot be SROA'd. 9439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner bool isUnsafe : 1; 956974302e3ff20746268721959efed807c7711bfcBob Wilson 9639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// isMemCpySrc - This is true if this aggregate is memcpy'd from. 9739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner bool isMemCpySrc : 1; 9839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 9933b0b8d242de8d428f11e77ea734a08b47797216Zhou Sheng /// isMemCpyDst - This is true if this aggregate is memcpy'd into. 10039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner bool isMemCpyDst : 1; 10139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 1027e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner /// hasSubelementAccess - This is true if a subelement of the alloca is 1037e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner /// ever accessed, or false if the alloca is only accessed with mem 1047e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner /// intrinsics or load/store that only access the entire alloca at once. 1057e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner bool hasSubelementAccess : 1; 1067e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner 1077e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner /// hasALoadOrStore - This is true if there are any loads or stores to it. 1087e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner /// The alloca may just be accessed with memcpy, for example, which would 1097e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner /// not set this. 1107e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner bool hasALoadOrStore : 1; 1117e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner 1126c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattner explicit AllocaInfo(AllocaInst *ai) 1136c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattner : AI(ai), isUnsafe(false), isMemCpySrc(false), isMemCpyDst(false), 1147e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner hasSubelementAccess(false), hasALoadOrStore(false) {} 11539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner }; 1166974302e3ff20746268721959efed807c7711bfcBob Wilson 117ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel unsigned SRThreshold; 118ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel 119d01a0da090407762fe3b770d84f049d72d06467eChris Lattner void MarkUnsafe(AllocaInfo &I, Instruction *User) { 120d01a0da090407762fe3b770d84f049d72d06467eChris Lattner I.isUnsafe = true; 121d01a0da090407762fe3b770d84f049d72d06467eChris Lattner DEBUG(dbgs() << " Transformation preventing inst: " << *User << '\n'); 122d01a0da090407762fe3b770d84f049d72d06467eChris Lattner } 12339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 1246c146eefbf75875250af37a0f1ea70fc6b4716eeVictor Hernandez bool isSafeAllocaToScalarRepl(AllocaInst *AI); 12539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 1266c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattner void isSafeForScalarRepl(Instruction *I, uint64_t Offset, AllocaInfo &Info); 127145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner void isSafePHISelectUseForScalarRepl(Instruction *User, uint64_t Offset, 128145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner AllocaInfo &Info); 1296c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattner void isSafeGEP(GetElementPtrInst *GEPI, uint64_t &Offset, AllocaInfo &Info); 1306c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattner void isSafeMemAccess(uint64_t Offset, uint64_t MemSize, 131d01a0da090407762fe3b770d84f049d72d06467eChris Lattner const Type *MemOpType, bool isStore, AllocaInfo &Info, 132145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner Instruction *TheAccess, bool AllowWholeAccess); 133b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson bool TypeHasComponent(const Type *T, uint64_t Offset, uint64_t Size); 134e88728d757d3090f1c0885b78d3675a7e143a2f9Bob Wilson uint64_t FindElementAndOffset(const Type *&T, uint64_t &Offset, 135e88728d757d3090f1c0885b78d3675a7e143a2f9Bob Wilson const Type *&IdxTy); 1366974302e3ff20746268721959efed807c7711bfcBob Wilson 1376974302e3ff20746268721959efed807c7711bfcBob Wilson void DoScalarReplacement(AllocaInst *AI, 1387b929dad59785f62a66f7c58615082f98441e95eVictor Hernandez std::vector<AllocaInst*> &WorkList); 139b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson void DeleteDeadInstructions(); 1406974302e3ff20746268721959efed807c7711bfcBob Wilson 141b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson void RewriteForScalarRepl(Instruction *I, AllocaInst *AI, uint64_t Offset, 142b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson SmallVector<AllocaInst*, 32> &NewElts); 143b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson void RewriteBitCast(BitCastInst *BC, AllocaInst *AI, uint64_t Offset, 144b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson SmallVector<AllocaInst*, 32> &NewElts); 145b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson void RewriteGEP(GetElementPtrInst *GEPI, AllocaInst *AI, uint64_t Offset, 146b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson SmallVector<AllocaInst*, 32> &NewElts); 147b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson void RewriteMemIntrinUserOfAlloca(MemIntrinsic *MI, Instruction *Inst, 1487b929dad59785f62a66f7c58615082f98441e95eVictor Hernandez AllocaInst *AI, 149d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner SmallVector<AllocaInst*, 32> &NewElts); 1507b929dad59785f62a66f7c58615082f98441e95eVictor Hernandez void RewriteStoreUserOfWholeAlloca(StoreInst *SI, AllocaInst *AI, 151d2fa781169175b827e50953a1d0b7edc6b0c4801Chris Lattner SmallVector<AllocaInst*, 32> &NewElts); 1527b929dad59785f62a66f7c58615082f98441e95eVictor Hernandez void RewriteLoadUserOfWholeAlloca(LoadInst *LI, AllocaInst *AI, 1536e733d34ca487ab7ff8a6def018a933620393869Chris Lattner SmallVector<AllocaInst*, 32> &NewElts); 1546974302e3ff20746268721959efed807c7711bfcBob Wilson 15531d80103d56c026403d7fb6c50833664ff63ddcbChris Lattner static MemTransferInst *isOnlyCopiedFromConstantGlobal(AllocaInst *AI); 156ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner }; 157b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner 158b1686c32fc694636cbf15a59b23b2a741b65ecf4Cameron Zwarich // SROA_DT - SROA that uses DominatorTree. 159b1686c32fc694636cbf15a59b23b2a741b65ecf4Cameron Zwarich struct SROA_DT : public SROA { 160b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner static char ID; 161b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner public: 162b1686c32fc694636cbf15a59b23b2a741b65ecf4Cameron Zwarich SROA_DT(int T = -1) : SROA(T, true, ID) { 163b1686c32fc694636cbf15a59b23b2a741b65ecf4Cameron Zwarich initializeSROA_DTPass(*PassRegistry::getPassRegistry()); 164b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner } 165b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner 166b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner // getAnalysisUsage - This pass does not require any passes, but we know it 167b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner // will not alter the CFG, so say so. 168b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner virtual void getAnalysisUsage(AnalysisUsage &AU) const { 169b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner AU.addRequired<DominatorTree>(); 170b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner AU.setPreservesCFG(); 171b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner } 172b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner }; 173b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner 174b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner // SROA_SSAUp - SROA that uses SSAUpdater. 175b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner struct SROA_SSAUp : public SROA { 176b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner static char ID; 177b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner public: 178b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner SROA_SSAUp(int T = -1) : SROA(T, false, ID) { 179b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner initializeSROA_SSAUpPass(*PassRegistry::getPassRegistry()); 180b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner } 181b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner 182b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner // getAnalysisUsage - This pass does not require any passes, but we know it 183b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner // will not alter the CFG, so say so. 184b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner virtual void getAnalysisUsage(AnalysisUsage &AU) const { 185b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner AU.setPreservesCFG(); 186b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner } 187b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner }; 188b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner 189ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner} 190ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 191b1686c32fc694636cbf15a59b23b2a741b65ecf4Cameron Zwarichchar SROA_DT::ID = 0; 192b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattnerchar SROA_SSAUp::ID = 0; 193b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner 194b1686c32fc694636cbf15a59b23b2a741b65ecf4Cameron ZwarichINITIALIZE_PASS_BEGIN(SROA_DT, "scalarrepl", 195b1686c32fc694636cbf15a59b23b2a741b65ecf4Cameron Zwarich "Scalar Replacement of Aggregates (DT)", false, false) 1962ab36d350293c77fc8941ce1023e4899df7e3a82Owen AndersonINITIALIZE_PASS_DEPENDENCY(DominatorTree) 197b1686c32fc694636cbf15a59b23b2a741b65ecf4Cameron ZwarichINITIALIZE_PASS_END(SROA_DT, "scalarrepl", 198b1686c32fc694636cbf15a59b23b2a741b65ecf4Cameron Zwarich "Scalar Replacement of Aggregates (DT)", false, false) 199b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner 200b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris LattnerINITIALIZE_PASS_BEGIN(SROA_SSAUp, "scalarrepl-ssa", 201b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner "Scalar Replacement of Aggregates (SSAUp)", false, false) 202b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris LattnerINITIALIZE_PASS_END(SROA_SSAUp, "scalarrepl-ssa", 203b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner "Scalar Replacement of Aggregates (SSAUp)", false, false) 204844731a7f1909f55935e3514c9e713a62d67662eDan Gohman 205d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke// Public interface to the ScalarReplAggregates pass 206b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris LattnerFunctionPass *llvm::createScalarReplAggregatesPass(int Threshold, 207b1686c32fc694636cbf15a59b23b2a741b65ecf4Cameron Zwarich bool UseDomTree) { 208b1686c32fc694636cbf15a59b23b2a741b65ecf4Cameron Zwarich if (UseDomTree) 209b1686c32fc694636cbf15a59b23b2a741b65ecf4Cameron Zwarich return new SROA_DT(Threshold); 210b352d6eb49927a7c707cbd9046cfc525b0c3f2d7Chris Lattner return new SROA_SSAUp(Threshold); 211ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel} 212ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 213ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 2144cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner//===----------------------------------------------------------------------===// 2154cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner// Convert To Scalar Optimization. 2164cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner//===----------------------------------------------------------------------===// 217963a97f1a365c8d09ca681e922371f9ec3473ee8Chris Lattner 218c4472072641f702dbd99ae12b7da089e75c44a99Chris Lattnernamespace { 219a001b664988f759d194f3d5d880c61449219fc2eChris Lattner/// ConvertToScalarInfo - This class implements the "Convert To Scalar" 220a001b664988f759d194f3d5d880c61449219fc2eChris Lattner/// optimization, which scans the uses of an alloca and determines if it can 221a001b664988f759d194f3d5d880c61449219fc2eChris Lattner/// rewrite it in terms of a single new alloca that can be mem2reg'd. 2224cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattnerclass ConvertToScalarInfo { 223d4c9c3e6b97e095c24d989c0f5ce763f90100ef1Cameron Zwarich /// AllocaSize - The size of the alloca being considered in bytes. 224c4472072641f702dbd99ae12b7da089e75c44a99Chris Lattner unsigned AllocaSize; 225593375d04ab32be0161607a741d310172f142b93Chris Lattner const TargetData &TD; 2266974302e3ff20746268721959efed807c7711bfcBob Wilson 227a0bada729ffaa1bfc80ef25935bdc5a67432708fChris Lattner /// IsNotTrivial - This is set to true if there is some access to the object 228a001b664988f759d194f3d5d880c61449219fc2eChris Lattner /// which means that mem2reg can't promote it. 229c4472072641f702dbd99ae12b7da089e75c44a99Chris Lattner bool IsNotTrivial; 2306974302e3ff20746268721959efed807c7711bfcBob Wilson 231a001b664988f759d194f3d5d880c61449219fc2eChris Lattner /// VectorTy - This tracks the type that we should promote the vector to if 232a001b664988f759d194f3d5d880c61449219fc2eChris Lattner /// it is possible to turn it into a vector. This starts out null, and if it 233a001b664988f759d194f3d5d880c61449219fc2eChris Lattner /// isn't possible to turn into a vector type, it gets set to VoidTy. 234c4472072641f702dbd99ae12b7da089e75c44a99Chris Lattner const Type *VectorTy; 2356974302e3ff20746268721959efed807c7711bfcBob Wilson 236a001b664988f759d194f3d5d880c61449219fc2eChris Lattner /// HadAVector - True if there is at least one vector access to the alloca. 237a001b664988f759d194f3d5d880c61449219fc2eChris Lattner /// We don't want to turn random arrays into vectors and use vector element 238a001b664988f759d194f3d5d880c61449219fc2eChris Lattner /// insert/extract, but if there are element accesses to something that is 239a001b664988f759d194f3d5d880c61449219fc2eChris Lattner /// also declared as a vector, we do want to promote to a vector. 240c4472072641f702dbd99ae12b7da089e75c44a99Chris Lattner bool HadAVector; 241c4472072641f702dbd99ae12b7da089e75c44a99Chris Lattner 2421bcdb6ffad79936a96b46080bf0fed867243b32aCameron Zwarich /// HadNonMemTransferAccess - True if there is at least one access to the 2431bcdb6ffad79936a96b46080bf0fed867243b32aCameron Zwarich /// alloca that is not a MemTransferInst. We don't want to turn structs into 2441bcdb6ffad79936a96b46080bf0fed867243b32aCameron Zwarich /// large integers unless there is some potential for optimization. 24585b0f468cf8390fca3ec356cd498ce0039dbad4fCameron Zwarich bool HadNonMemTransferAccess; 24685b0f468cf8390fca3ec356cd498ce0039dbad4fCameron Zwarich 2474cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattnerpublic: 248593375d04ab32be0161607a741d310172f142b93Chris Lattner explicit ConvertToScalarInfo(unsigned Size, const TargetData &td) 249deac268f893d5dadea845466fa0e5a11647c6113Cameron Zwarich : AllocaSize(Size), TD(td), IsNotTrivial(false), VectorTy(0), 25085b0f468cf8390fca3ec356cd498ce0039dbad4fCameron Zwarich HadAVector(false), HadNonMemTransferAccess(false) { } 2516974302e3ff20746268721959efed807c7711bfcBob Wilson 252a001b664988f759d194f3d5d880c61449219fc2eChris Lattner AllocaInst *TryConvert(AllocaInst *AI); 2536974302e3ff20746268721959efed807c7711bfcBob Wilson 2544cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattnerprivate: 255593375d04ab32be0161607a741d310172f142b93Chris Lattner bool CanConvertToScalar(Value *V, uint64_t Offset); 256dd68912801861273dc3dca33cfc18357213049a4Cameron Zwarich void MergeInType(const Type *In, uint64_t Offset); 257c9ecd14cee020f884313b60f8696384d3e7848f7Cameron Zwarich bool MergeInVectorType(const VectorType *VInTy, uint64_t Offset); 258593375d04ab32be0161607a741d310172f142b93Chris Lattner void ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI, uint64_t Offset); 2596974302e3ff20746268721959efed807c7711bfcBob Wilson 260593375d04ab32be0161607a741d310172f142b93Chris Lattner Value *ConvertScalar_ExtractValue(Value *NV, const Type *ToType, 261593375d04ab32be0161607a741d310172f142b93Chris Lattner uint64_t Offset, IRBuilder<> &Builder); 262593375d04ab32be0161607a741d310172f142b93Chris Lattner Value *ConvertScalar_InsertValue(Value *StoredVal, Value *ExistingVal, 263593375d04ab32be0161607a741d310172f142b93Chris Lattner uint64_t Offset, IRBuilder<> &Builder); 264c4472072641f702dbd99ae12b7da089e75c44a99Chris Lattner}; 265c4472072641f702dbd99ae12b7da089e75c44a99Chris Lattner} // end anonymous namespace. 266c4472072641f702dbd99ae12b7da089e75c44a99Chris Lattner 26791abace4ef6fdfe01bcebfb8e90938e71f8a5c4fChris Lattner 268a001b664988f759d194f3d5d880c61449219fc2eChris Lattner/// TryConvert - Analyze the specified alloca, and if it is safe to do so, 269a001b664988f759d194f3d5d880c61449219fc2eChris Lattner/// rewrite it to be a new alloca which is mem2reg'able. This returns the new 270a001b664988f759d194f3d5d880c61449219fc2eChris Lattner/// alloca if possible or null if not. 271a001b664988f759d194f3d5d880c61449219fc2eChris LattnerAllocaInst *ConvertToScalarInfo::TryConvert(AllocaInst *AI) { 272a001b664988f759d194f3d5d880c61449219fc2eChris Lattner // If we can't convert this scalar, or if mem2reg can trivially do it, bail 273a001b664988f759d194f3d5d880c61449219fc2eChris Lattner // out. 274a001b664988f759d194f3d5d880c61449219fc2eChris Lattner if (!CanConvertToScalar(AI, 0) || !IsNotTrivial) 275a001b664988f759d194f3d5d880c61449219fc2eChris Lattner return 0; 2766974302e3ff20746268721959efed807c7711bfcBob Wilson 277a001b664988f759d194f3d5d880c61449219fc2eChris Lattner // If we were able to find a vector type that can handle this with 278a001b664988f759d194f3d5d880c61449219fc2eChris Lattner // insert/extract elements, and if there was at least one use that had 279a001b664988f759d194f3d5d880c61449219fc2eChris Lattner // a vector type, promote this to a vector. We don't want to promote 280a001b664988f759d194f3d5d880c61449219fc2eChris Lattner // random stuff that doesn't use vectors (e.g. <9 x double>) because then 281a001b664988f759d194f3d5d880c61449219fc2eChris Lattner // we just get a lot of insert/extracts. If at least one vector is 282a001b664988f759d194f3d5d880c61449219fc2eChris Lattner // involved, then we probably really do have a union of vector/array. 283a001b664988f759d194f3d5d880c61449219fc2eChris Lattner const Type *NewTy; 28485a7c690852d6151acff0d8821762d75bc774ab4Chris Lattner if (VectorTy && VectorTy->isVectorTy() && HadAVector) { 285a001b664988f759d194f3d5d880c61449219fc2eChris Lattner DEBUG(dbgs() << "CONVERT TO VECTOR: " << *AI << "\n TYPE = " 286a001b664988f759d194f3d5d880c61449219fc2eChris Lattner << *VectorTy << '\n'); 287a001b664988f759d194f3d5d880c61449219fc2eChris Lattner NewTy = VectorTy; // Use the vector type. 288a001b664988f759d194f3d5d880c61449219fc2eChris Lattner } else { 28985b0f468cf8390fca3ec356cd498ce0039dbad4fCameron Zwarich unsigned BitWidth = AllocaSize * 8; 29085b0f468cf8390fca3ec356cd498ce0039dbad4fCameron Zwarich if (!HadAVector && !HadNonMemTransferAccess && 29185b0f468cf8390fca3ec356cd498ce0039dbad4fCameron Zwarich !TD.fitsInLegalInteger(BitWidth)) 29285b0f468cf8390fca3ec356cd498ce0039dbad4fCameron Zwarich return 0; 29385b0f468cf8390fca3ec356cd498ce0039dbad4fCameron Zwarich 294a001b664988f759d194f3d5d880c61449219fc2eChris Lattner DEBUG(dbgs() << "CONVERT TO SCALAR INTEGER: " << *AI << "\n"); 295a001b664988f759d194f3d5d880c61449219fc2eChris Lattner // Create and insert the integer alloca. 29685b0f468cf8390fca3ec356cd498ce0039dbad4fCameron Zwarich NewTy = IntegerType::get(AI->getContext(), BitWidth); 297a001b664988f759d194f3d5d880c61449219fc2eChris Lattner } 298a001b664988f759d194f3d5d880c61449219fc2eChris Lattner AllocaInst *NewAI = new AllocaInst(NewTy, 0, "", AI->getParent()->begin()); 299a001b664988f759d194f3d5d880c61449219fc2eChris Lattner ConvertUsesToScalar(AI, NewAI, 0); 300a001b664988f759d194f3d5d880c61449219fc2eChris Lattner return NewAI; 301a001b664988f759d194f3d5d880c61449219fc2eChris Lattner} 302a001b664988f759d194f3d5d880c61449219fc2eChris Lattner 303a001b664988f759d194f3d5d880c61449219fc2eChris Lattner/// MergeInType - Add the 'In' type to the accumulated vector type (VectorTy) 304a001b664988f759d194f3d5d880c61449219fc2eChris Lattner/// so far at the offset specified by Offset (which is specified in bytes). 3054cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// 306b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich/// There are three cases we handle here: 3074cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// 1) A union of vector types of the same size and potentially its elements. 3084cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// Here we turn element accesses into insert/extract element operations. 3094cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// This promotes a <4 x float> with a store of float to the third element 3104cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// into a <4 x float> that uses insert element. 311b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich/// 2) A union of vector types with power-of-2 size differences, e.g. a float, 312b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich/// <2 x float> and <4 x float>. Here we turn element accesses into insert 313b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich/// and extract element operations, and <2 x float> accesses into a cast to 314b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich/// <2 x double>, an extract, and a cast back to <2 x float>. 315b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich/// 3) A fully general blob of memory, which we turn into some (potentially 3164cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// large) integer type with extract and insert operations where the loads 317a001b664988f759d194f3d5d880c61449219fc2eChris Lattner/// and stores would mutate the memory. We mark this by setting VectorTy 318a001b664988f759d194f3d5d880c61449219fc2eChris Lattner/// to VoidTy. 319dd68912801861273dc3dca33cfc18357213049a4Cameron Zwarichvoid ConvertToScalarInfo::MergeInType(const Type *In, uint64_t Offset) { 320a001b664988f759d194f3d5d880c61449219fc2eChris Lattner // If we already decided to turn this into a blob of integer memory, there is 321a001b664988f759d194f3d5d880c61449219fc2eChris Lattner // nothing to be done. 3224cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (VectorTy && VectorTy->isVoidTy()) 3234cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return; 3246974302e3ff20746268721959efed807c7711bfcBob Wilson 3254cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If this could be contributing to a vector, analyze it. 326c4472072641f702dbd99ae12b7da089e75c44a99Chris Lattner 3274cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If the In type is a vector that is the same size as the alloca, see if it 3284cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // matches the existing VecTy. 3294cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (const VectorType *VInTy = dyn_cast<VectorType>(In)) { 330c9ecd14cee020f884313b60f8696384d3e7848f7Cameron Zwarich if (MergeInVectorType(VInTy, Offset)) 3314cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return; 3324cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else if (In->isFloatTy() || In->isDoubleTy() || 3334cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner (In->isIntegerTy() && In->getPrimitiveSizeInBits() >= 8 && 3344cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner isPowerOf2_32(In->getPrimitiveSizeInBits()))) { 3359827b78b51f285e90c2b1e5add9b28d10c88595cCameron Zwarich // Full width accesses can be ignored, because they can always be turned 3369827b78b51f285e90c2b1e5add9b28d10c88595cCameron Zwarich // into bitcasts. 3379827b78b51f285e90c2b1e5add9b28d10c88595cCameron Zwarich unsigned EltSize = In->getPrimitiveSizeInBits()/8; 338dd68912801861273dc3dca33cfc18357213049a4Cameron Zwarich if (EltSize == AllocaSize) 3399827b78b51f285e90c2b1e5add9b28d10c88595cCameron Zwarich return; 3405fc1282c1822d692ed1681cdc4c315950c6eb1d8Cameron Zwarich 3414cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If we're accessing something that could be an element of a vector, see 3424cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // if the implied vector agrees with what we already have and if Offset is 3434cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // compatible with it. 34496cc1d0dfbcf9c7ffffc65f0aa008ff532d444f4Cameron Zwarich if (Offset % EltSize == 0 && AllocaSize % EltSize == 0 && 345c4f78208b399111cc4f5d97ed1875566819f34b4Cameron Zwarich (!VectorTy || Offset * 8 < VectorTy->getPrimitiveSizeInBits())) { 3465fc1282c1822d692ed1681cdc4c315950c6eb1d8Cameron Zwarich if (!VectorTy) { 3474cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner VectorTy = VectorType::get(In, AllocaSize/EltSize); 3485fc1282c1822d692ed1681cdc4c315950c6eb1d8Cameron Zwarich return; 3495fc1282c1822d692ed1681cdc4c315950c6eb1d8Cameron Zwarich } 3505fc1282c1822d692ed1681cdc4c315950c6eb1d8Cameron Zwarich 3515fc1282c1822d692ed1681cdc4c315950c6eb1d8Cameron Zwarich unsigned CurrentEltSize = cast<VectorType>(VectorTy)->getElementType() 3525fc1282c1822d692ed1681cdc4c315950c6eb1d8Cameron Zwarich ->getPrimitiveSizeInBits()/8; 3535fc1282c1822d692ed1681cdc4c315950c6eb1d8Cameron Zwarich if (EltSize == CurrentEltSize) 3545fc1282c1822d692ed1681cdc4c315950c6eb1d8Cameron Zwarich return; 355344731c01805aeda49c747bac6148501fa85557cCameron Zwarich 356344731c01805aeda49c747bac6148501fa85557cCameron Zwarich if (In->isIntegerTy() && isPowerOf2_32(AllocaSize / EltSize)) 357344731c01805aeda49c747bac6148501fa85557cCameron Zwarich return; 3584cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 3594cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 3606974302e3ff20746268721959efed807c7711bfcBob Wilson 3614cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Otherwise, we have a case that we can't handle with an optimized vector 3624cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // form. We can still turn this into a large integer. 3634cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner VectorTy = Type::getVoidTy(In->getContext()); 3644cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner} 365c4472072641f702dbd99ae12b7da089e75c44a99Chris Lattner 366c9ecd14cee020f884313b60f8696384d3e7848f7Cameron Zwarich/// MergeInVectorType - Handles the vector case of MergeInType, returning true 367c9ecd14cee020f884313b60f8696384d3e7848f7Cameron Zwarich/// if the type was successfully merged and false otherwise. 368c9ecd14cee020f884313b60f8696384d3e7848f7Cameron Zwarichbool ConvertToScalarInfo::MergeInVectorType(const VectorType *VInTy, 369c9ecd14cee020f884313b60f8696384d3e7848f7Cameron Zwarich uint64_t Offset) { 370c9ecd14cee020f884313b60f8696384d3e7848f7Cameron Zwarich // Remember if we saw a vector type. 371c9ecd14cee020f884313b60f8696384d3e7848f7Cameron Zwarich HadAVector = true; 372c9ecd14cee020f884313b60f8696384d3e7848f7Cameron Zwarich 373b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich // TODO: Support nonzero offsets? 374b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich if (Offset != 0) 375b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich return false; 376b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich 377b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich // Only allow vectors that are a power-of-2 away from the size of the alloca. 378b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich if (!isPowerOf2_64(AllocaSize / (VInTy->getBitWidth() / 8))) 379b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich return false; 380b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich 381b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich // If this the first vector we see, remember the type so that we know the 382b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich // element size. 383b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich if (!VectorTy) { 384b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich VectorTy = VInTy; 385c9ecd14cee020f884313b60f8696384d3e7848f7Cameron Zwarich return true; 386c9ecd14cee020f884313b60f8696384d3e7848f7Cameron Zwarich } 387c9ecd14cee020f884313b60f8696384d3e7848f7Cameron Zwarich 388b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich unsigned BitWidth = cast<VectorType>(VectorTy)->getBitWidth(); 389b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich unsigned InBitWidth = VInTy->getBitWidth(); 390b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich 391b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich // Vectors of the same size can be converted using a simple bitcast. 392b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich if (InBitWidth == BitWidth && AllocaSize == (InBitWidth / 8)) 393b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich return true; 394b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich 395b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich const Type *ElementTy = cast<VectorType>(VectorTy)->getElementType(); 396c77a10fe0a40861bcb4bd2a0c170c948a57be688Cameron Zwarich const Type *InElementTy = cast<VectorType>(VInTy)->getElementType(); 397b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich 398b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich // Do not allow mixed integer and floating-point accesses from vectors of 399b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich // different sizes. 400b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich if (ElementTy->isFloatingPointTy() != InElementTy->isFloatingPointTy()) 401b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich return false; 402b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich 403b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich if (ElementTy->isFloatingPointTy()) { 404b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich // Only allow floating-point vectors of different sizes if they have the 405b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich // same element type. 406b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich // TODO: This could be loosened a bit, but would anything benefit? 407b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich if (ElementTy != InElementTy) 408b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich return false; 409b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich 410b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich // There are no arbitrary-precision floating-point types, which limits the 411b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich // number of legal vector types with larger element types that we can form 412b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich // to bitcast and extract a subvector. 413b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich // TODO: We could support some more cases with mixed fp128 and double here. 414b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich if (!(BitWidth == 64 || BitWidth == 128) || 415b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich !(InBitWidth == 64 || InBitWidth == 128)) 416b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich return false; 417b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich } else { 418b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich assert(ElementTy->isIntegerTy() && "Vector elements must be either integer " 419b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich "or floating-point."); 420b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich unsigned BitWidth = ElementTy->getPrimitiveSizeInBits(); 421b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich unsigned InBitWidth = InElementTy->getPrimitiveSizeInBits(); 422b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich 423b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich // Do not allow integer types smaller than a byte or types whose widths are 424b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich // not a multiple of a byte. 425b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich if (BitWidth < 8 || InBitWidth < 8 || 426b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich BitWidth % 8 != 0 || InBitWidth % 8 != 0) 427b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich return false; 428b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich } 429b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich 430b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich // Pick the largest of the two vector types. 431b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich if (InBitWidth > BitWidth) 432b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich VectorTy = VInTy; 433b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich 434b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich return true; 435c9ecd14cee020f884313b60f8696384d3e7848f7Cameron Zwarich} 436c9ecd14cee020f884313b60f8696384d3e7848f7Cameron Zwarich 4374cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// CanConvertToScalar - V is a pointer. If we can convert the pointee and all 4384cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// its accesses to a single vector type, return true and set VecTy to 4394cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// the new type. If we could convert the alloca into a single promotable 4404cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// integer, return true but set VecTy to VoidTy. Further, if the use is not a 4414cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// completely trivial use that mem2reg could promote, set IsNotTrivial. Offset 4424cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// is the current offset from the base of the alloca being analyzed. 4434cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// 4444cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// If we see at least one access to the value that is as a vector type, set the 4454cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// SawVec flag. 4464cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattnerbool ConvertToScalarInfo::CanConvertToScalar(Value *V, uint64_t Offset) { 4474cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI!=E; ++UI) { 4484cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Instruction *User = cast<Instruction>(*UI); 4496974302e3ff20746268721959efed807c7711bfcBob Wilson 4504cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(User)) { 4514cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Don't break volatile loads. 4524cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (LI->isVolatile()) 4534cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return false; 4540488fb649a56b7fc89a5814df5308813f9e5a85dDale Johannesen // Don't touch MMX operations. 4550488fb649a56b7fc89a5814df5308813f9e5a85dDale Johannesen if (LI->getType()->isX86_MMXTy()) 4560488fb649a56b7fc89a5814df5308813f9e5a85dDale Johannesen return false; 45785b0f468cf8390fca3ec356cd498ce0039dbad4fCameron Zwarich HadNonMemTransferAccess = true; 458dd68912801861273dc3dca33cfc18357213049a4Cameron Zwarich MergeInType(LI->getType(), Offset); 459add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner continue; 460add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner } 4616974302e3ff20746268721959efed807c7711bfcBob Wilson 4624cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (StoreInst *SI = dyn_cast<StoreInst>(User)) { 4634cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Storing the pointer, not into the value? 4644cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (SI->getOperand(0) == V || SI->isVolatile()) return false; 4650488fb649a56b7fc89a5814df5308813f9e5a85dDale Johannesen // Don't touch MMX operations. 4660488fb649a56b7fc89a5814df5308813f9e5a85dDale Johannesen if (SI->getOperand(0)->getType()->isX86_MMXTy()) 4670488fb649a56b7fc89a5814df5308813f9e5a85dDale Johannesen return false; 46885b0f468cf8390fca3ec356cd498ce0039dbad4fCameron Zwarich HadNonMemTransferAccess = true; 469dd68912801861273dc3dca33cfc18357213049a4Cameron Zwarich MergeInType(SI->getOperand(0)->getType(), Offset); 4707809ecd5b019d26498499121f4d9c0b7de2f0a14Chris Lattner continue; 4717809ecd5b019d26498499121f4d9c0b7de2f0a14Chris Lattner } 4726974302e3ff20746268721959efed807c7711bfcBob Wilson 4734cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (BitCastInst *BCI = dyn_cast<BitCastInst>(User)) { 474a001b664988f759d194f3d5d880c61449219fc2eChris Lattner IsNotTrivial = true; // Can't be mem2reg'd. 4754cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (!CanConvertToScalar(BCI, Offset)) 4764cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return false; 4773992feb075b27ff37b63017078a977206f97d10dBob Wilson continue; 4783992feb075b27ff37b63017078a977206f97d10dBob Wilson } 4793992feb075b27ff37b63017078a977206f97d10dBob Wilson 4804cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(User)) { 4814cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If this is a GEP with a variable indices, we can't handle it. 4824cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (!GEP->hasAllConstantIndices()) 4834cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return false; 4846974302e3ff20746268721959efed807c7711bfcBob Wilson 4854cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Compute the offset that this GEP adds to the pointer. 4864cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SmallVector<Value*, 8> Indices(GEP->op_begin()+1, GEP->op_end()); 4874cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t GEPOffset = TD.getIndexedOffset(GEP->getPointerOperandType(), 4884cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner &Indices[0], Indices.size()); 4894cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // See if all uses can be converted. 4904cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (!CanConvertToScalar(GEP, Offset+GEPOffset)) 4914cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return false; 492a001b664988f759d194f3d5d880c61449219fc2eChris Lattner IsNotTrivial = true; // Can't be mem2reg'd. 49385b0f468cf8390fca3ec356cd498ce0039dbad4fCameron Zwarich HadNonMemTransferAccess = true; 4947809ecd5b019d26498499121f4d9c0b7de2f0a14Chris Lattner continue; 4954cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 496ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 4974cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If this is a constant sized memset of a constant value (e.g. 0) we can 4984cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // handle it. 4994cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (MemSetInst *MSI = dyn_cast<MemSetInst>(User)) { 5004cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Store of constant value and constant size. 501a001b664988f759d194f3d5d880c61449219fc2eChris Lattner if (!isa<ConstantInt>(MSI->getValue()) || 502a001b664988f759d194f3d5d880c61449219fc2eChris Lattner !isa<ConstantInt>(MSI->getLength())) 503a001b664988f759d194f3d5d880c61449219fc2eChris Lattner return false; 504a001b664988f759d194f3d5d880c61449219fc2eChris Lattner IsNotTrivial = true; // Can't be mem2reg'd. 50585b0f468cf8390fca3ec356cd498ce0039dbad4fCameron Zwarich HadNonMemTransferAccess = true; 506a001b664988f759d194f3d5d880c61449219fc2eChris Lattner continue; 5074cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 508fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 5094cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If this is a memcpy or memmove into or out of the whole allocation, we 5104cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // can handle it like a load or store of the scalar type. 5114cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(User)) { 512a001b664988f759d194f3d5d880c61449219fc2eChris Lattner ConstantInt *Len = dyn_cast<ConstantInt>(MTI->getLength()); 513a001b664988f759d194f3d5d880c61449219fc2eChris Lattner if (Len == 0 || Len->getZExtValue() != AllocaSize || Offset != 0) 514a001b664988f759d194f3d5d880c61449219fc2eChris Lattner return false; 5156974302e3ff20746268721959efed807c7711bfcBob Wilson 516a001b664988f759d194f3d5d880c61449219fc2eChris Lattner IsNotTrivial = true; // Can't be mem2reg'd. 517a001b664988f759d194f3d5d880c61449219fc2eChris Lattner continue; 518ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner } 5196974302e3ff20746268721959efed807c7711bfcBob Wilson 5204cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Otherwise, we cannot handle this! 5214cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return false; 522a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 5236974302e3ff20746268721959efed807c7711bfcBob Wilson 5244cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return true; 525ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner} 526a59adc40153f3e0f9843952c127d179b5ebe6c4cChris Lattner 5274cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// ConvertUsesToScalar - Convert all of the users of Ptr to use the new alloca 5284cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// directly. This happens when we are converting an "integer union" to a 5294cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// single integer scalar, or when we are converting a "vector union" to a 5304cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// vector with insert/extractelement instructions. 5314cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// 5324cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// Offset is an offset from the original alloca, in bits that need to be 5334cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// shifted to the right. By the end of this, there should be no uses of Ptr. 5344cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattnervoid ConvertToScalarInfo::ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI, 5354cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t Offset) { 5364cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner while (!Ptr->use_empty()) { 5374cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Instruction *User = cast<Instruction>(Ptr->use_back()); 538b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson 5394cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (BitCastInst *CI = dyn_cast<BitCastInst>(User)) { 5404cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ConvertUsesToScalar(CI, NewAI, Offset); 5414cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner CI->eraseFromParent(); 5424cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner continue; 5434cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 544b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson 5454cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(User)) { 5464cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Compute the offset that this GEP adds to the pointer. 5474cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SmallVector<Value*, 8> Indices(GEP->op_begin()+1, GEP->op_end()); 5484cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t GEPOffset = TD.getIndexedOffset(GEP->getPointerOperandType(), 5494cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner &Indices[0], Indices.size()); 5504cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ConvertUsesToScalar(GEP, NewAI, Offset+GEPOffset*8); 5514cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner GEP->eraseFromParent(); 5524cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner continue; 5534cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 5546974302e3ff20746268721959efed807c7711bfcBob Wilson 55561db1f56d0b717d67557bbb2a9d83af1449458cbChris Lattner IRBuilder<> Builder(User); 5566974302e3ff20746268721959efed807c7711bfcBob Wilson 5574cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(User)) { 5584cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // The load is a bit extract from NewAI shifted right by Offset bits. 5594cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *LoadedVal = Builder.CreateLoad(NewAI, "tmp"); 5604cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *NewLoadVal 5614cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner = ConvertScalar_ExtractValue(LoadedVal, LI->getType(), Offset, Builder); 5624cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner LI->replaceAllUsesWith(NewLoadVal); 5634cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner LI->eraseFromParent(); 5644cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner continue; 5654cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 5666974302e3ff20746268721959efed807c7711bfcBob Wilson 5674cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (StoreInst *SI = dyn_cast<StoreInst>(User)) { 5684cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner assert(SI->getOperand(0) != Ptr && "Consistency error!"); 5694cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Instruction *Old = Builder.CreateLoad(NewAI, NewAI->getName()+".in"); 5704cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *New = ConvertScalar_InsertValue(SI->getOperand(0), Old, Offset, 5714cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Builder); 5724cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Builder.CreateStore(New, NewAI); 5734cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SI->eraseFromParent(); 5746974302e3ff20746268721959efed807c7711bfcBob Wilson 5754cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If the load we just inserted is now dead, then the inserted store 5764cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // overwrote the entire thing. 5774cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Old->use_empty()) 5784cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Old->eraseFromParent(); 5794cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner continue; 5804cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 5816974302e3ff20746268721959efed807c7711bfcBob Wilson 5824cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If this is a constant sized memset of a constant value (e.g. 0) we can 5834cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // transform it into a store of the expanded constant value. 5844cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (MemSetInst *MSI = dyn_cast<MemSetInst>(User)) { 5854cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner assert(MSI->getRawDest() == Ptr && "Consistency error!"); 5864cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner unsigned NumBytes = cast<ConstantInt>(MSI->getLength())->getZExtValue(); 5874cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (NumBytes != 0) { 5884cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner unsigned Val = cast<ConstantInt>(MSI->getValue())->getZExtValue(); 5896974302e3ff20746268721959efed807c7711bfcBob Wilson 5904cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Compute the value replicated the right number of times. 5914cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner APInt APVal(NumBytes*8, Val); 5922674089cefe519195e00bdf879647438cfb1cb0fDaniel Dunbar 5934cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Splat the value if non-zero. 5944cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Val) 5954cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (unsigned i = 1; i != NumBytes; ++i) 5964cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner APVal |= APVal << 8; 5976974302e3ff20746268721959efed807c7711bfcBob Wilson 5984cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Instruction *Old = Builder.CreateLoad(NewAI, NewAI->getName()+".in"); 5994cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *New = ConvertScalar_InsertValue( 6004cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ConstantInt::get(User->getContext(), APVal), 6014cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Old, Offset, Builder); 6024cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Builder.CreateStore(New, NewAI); 6036974302e3ff20746268721959efed807c7711bfcBob Wilson 6044cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If the load we just inserted is now dead, then the memset overwrote 6054cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // the entire thing. 6064cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Old->use_empty()) 6076974302e3ff20746268721959efed807c7711bfcBob Wilson Old->eraseFromParent(); 6084cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 6094cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner MSI->eraseFromParent(); 6104cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner continue; 611b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson } 612fca55c8ac7d12e4139ad0ab7d74b76c47935aef6Daniel Dunbar 6134cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If this is a memcpy or memmove into or out of the whole allocation, we 6144cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // can handle it like a load or store of the scalar type. 6154cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(User)) { 6164cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner assert(Offset == 0 && "must be store to start of alloca"); 6176974302e3ff20746268721959efed807c7711bfcBob Wilson 6184cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If the source and destination are both to the same alloca, then this is 6194cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // a noop copy-to-self, just delete it. Otherwise, emit a load and store 6204cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // as appropriate. 621bd1801b5553c8be3960255a92738464e0010b6f6Dan Gohman AllocaInst *OrigAI = cast<AllocaInst>(GetUnderlyingObject(Ptr, &TD, 0)); 6226974302e3ff20746268721959efed807c7711bfcBob Wilson 623bd1801b5553c8be3960255a92738464e0010b6f6Dan Gohman if (GetUnderlyingObject(MTI->getSource(), &TD, 0) != OrigAI) { 6244cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Dest must be OrigAI, change this to be a load from the original 6254cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // pointer (bitcasted), then a store to our new alloca. 6264cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner assert(MTI->getRawDest() == Ptr && "Neither use is of pointer?"); 6274cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *SrcPtr = MTI->getSource(); 628e90a6333c3a4514f88c8a3dddd10d9bcddcd6d85Mon P Wang const PointerType* SPTy = cast<PointerType>(SrcPtr->getType()); 629e90a6333c3a4514f88c8a3dddd10d9bcddcd6d85Mon P Wang const PointerType* AIPTy = cast<PointerType>(NewAI->getType()); 630e90a6333c3a4514f88c8a3dddd10d9bcddcd6d85Mon P Wang if (SPTy->getAddressSpace() != AIPTy->getAddressSpace()) { 631e90a6333c3a4514f88c8a3dddd10d9bcddcd6d85Mon P Wang AIPTy = PointerType::get(AIPTy->getElementType(), 632e90a6333c3a4514f88c8a3dddd10d9bcddcd6d85Mon P Wang SPTy->getAddressSpace()); 633e90a6333c3a4514f88c8a3dddd10d9bcddcd6d85Mon P Wang } 634e90a6333c3a4514f88c8a3dddd10d9bcddcd6d85Mon P Wang SrcPtr = Builder.CreateBitCast(SrcPtr, AIPTy); 635e90a6333c3a4514f88c8a3dddd10d9bcddcd6d85Mon P Wang 6364cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner LoadInst *SrcVal = Builder.CreateLoad(SrcPtr, "srcval"); 6374cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SrcVal->setAlignment(MTI->getAlignment()); 6384cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Builder.CreateStore(SrcVal, NewAI); 639bd1801b5553c8be3960255a92738464e0010b6f6Dan Gohman } else if (GetUnderlyingObject(MTI->getDest(), &TD, 0) != OrigAI) { 6404cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Src must be OrigAI, change this to be a load from NewAI then a store 6414cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // through the original dest pointer (bitcasted). 6424cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner assert(MTI->getRawSource() == Ptr && "Neither use is of pointer?"); 6434cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner LoadInst *SrcVal = Builder.CreateLoad(NewAI, "srcval"); 644b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson 645e90a6333c3a4514f88c8a3dddd10d9bcddcd6d85Mon P Wang const PointerType* DPTy = cast<PointerType>(MTI->getDest()->getType()); 646e90a6333c3a4514f88c8a3dddd10d9bcddcd6d85Mon P Wang const PointerType* AIPTy = cast<PointerType>(NewAI->getType()); 647e90a6333c3a4514f88c8a3dddd10d9bcddcd6d85Mon P Wang if (DPTy->getAddressSpace() != AIPTy->getAddressSpace()) { 648e90a6333c3a4514f88c8a3dddd10d9bcddcd6d85Mon P Wang AIPTy = PointerType::get(AIPTy->getElementType(), 649e90a6333c3a4514f88c8a3dddd10d9bcddcd6d85Mon P Wang DPTy->getAddressSpace()); 650e90a6333c3a4514f88c8a3dddd10d9bcddcd6d85Mon P Wang } 651e90a6333c3a4514f88c8a3dddd10d9bcddcd6d85Mon P Wang Value *DstPtr = Builder.CreateBitCast(MTI->getDest(), AIPTy); 652e90a6333c3a4514f88c8a3dddd10d9bcddcd6d85Mon P Wang 6534cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner StoreInst *NewStore = Builder.CreateStore(SrcVal, DstPtr); 6544cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner NewStore->setAlignment(MTI->getAlignment()); 6554cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else { 6564cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Noop transfer. Src == Dst 6574cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 6585fac55fafb53fde5c548bcd08e07418e9d8e549fMatthijs Kooijman 6594cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner MTI->eraseFromParent(); 6604cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner continue; 6614cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 6626974302e3ff20746268721959efed807c7711bfcBob Wilson 6634cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner llvm_unreachable("Unsupported operation!"); 66488e6dc8bf14e8a98888f62173a6581386b8d29a0Chris Lattner } 6652674089cefe519195e00bdf879647438cfb1cb0fDaniel Dunbar} 6662674089cefe519195e00bdf879647438cfb1cb0fDaniel Dunbar 667b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich/// getScaledElementType - Gets a scaled element type for a partial vector 668344731c01805aeda49c747bac6148501fa85557cCameron Zwarich/// access of an alloca. The input types must be integer or floating-point 669344731c01805aeda49c747bac6148501fa85557cCameron Zwarich/// scalar or vector types, and the resulting type is an integer, float or 670344731c01805aeda49c747bac6148501fa85557cCameron Zwarich/// double. 671344731c01805aeda49c747bac6148501fa85557cCameron Zwarichstatic const Type *getScaledElementType(const Type *Ty1, const Type *Ty2, 6721537ce75ed25bbca58096383bb1fb9dd427bf1aaCameron Zwarich unsigned NewBitWidth) { 673344731c01805aeda49c747bac6148501fa85557cCameron Zwarich bool IsFP1 = Ty1->isFloatingPointTy() || 674344731c01805aeda49c747bac6148501fa85557cCameron Zwarich (Ty1->isVectorTy() && 675344731c01805aeda49c747bac6148501fa85557cCameron Zwarich cast<VectorType>(Ty1)->getElementType()->isFloatingPointTy()); 676344731c01805aeda49c747bac6148501fa85557cCameron Zwarich bool IsFP2 = Ty2->isFloatingPointTy() || 677344731c01805aeda49c747bac6148501fa85557cCameron Zwarich (Ty2->isVectorTy() && 678344731c01805aeda49c747bac6148501fa85557cCameron Zwarich cast<VectorType>(Ty2)->getElementType()->isFloatingPointTy()); 679344731c01805aeda49c747bac6148501fa85557cCameron Zwarich 680344731c01805aeda49c747bac6148501fa85557cCameron Zwarich LLVMContext &Context = Ty1->getContext(); 681344731c01805aeda49c747bac6148501fa85557cCameron Zwarich 682344731c01805aeda49c747bac6148501fa85557cCameron Zwarich // Prefer floating-point types over integer types, as integer types may have 683344731c01805aeda49c747bac6148501fa85557cCameron Zwarich // been created by earlier scalar replacement. 684344731c01805aeda49c747bac6148501fa85557cCameron Zwarich if (IsFP1 || IsFP2) { 685344731c01805aeda49c747bac6148501fa85557cCameron Zwarich if (NewBitWidth == 32) 686344731c01805aeda49c747bac6148501fa85557cCameron Zwarich return Type::getFloatTy(Context); 687344731c01805aeda49c747bac6148501fa85557cCameron Zwarich if (NewBitWidth == 64) 688344731c01805aeda49c747bac6148501fa85557cCameron Zwarich return Type::getDoubleTy(Context); 689344731c01805aeda49c747bac6148501fa85557cCameron Zwarich } 690b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich 691344731c01805aeda49c747bac6148501fa85557cCameron Zwarich return Type::getIntNTy(Context, NewBitWidth); 692b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich} 693b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich 694ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang/// CreateShuffleVectorCast - Creates a shuffle vector to convert one vector 695ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang/// to another vector of the same element type which has the same allocation 696ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang/// size but different primitive sizes (e.g. <3 x i32> and <4 x i32>). 697ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wangstatic Value *CreateShuffleVectorCast(Value *FromVal, const Type *ToType, 698ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang IRBuilder<> &Builder) { 699ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang const Type *FromType = FromVal->getType(); 700481823aa819ea1dd25567ae616dca93056ef770aMon P Wang const VectorType *FromVTy = cast<VectorType>(FromType); 701481823aa819ea1dd25567ae616dca93056ef770aMon P Wang const VectorType *ToVTy = cast<VectorType>(ToType); 702481823aa819ea1dd25567ae616dca93056ef770aMon P Wang assert((ToVTy->getElementType() == FromVTy->getElementType()) && 703ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang "Vectors must have the same element type"); 704ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang Value *UnV = UndefValue::get(FromType); 705ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang unsigned numEltsFrom = FromVTy->getNumElements(); 706ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang unsigned numEltsTo = ToVTy->getNumElements(); 707ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang 708ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang SmallVector<Constant*, 3> Args; 709481823aa819ea1dd25567ae616dca93056ef770aMon P Wang const Type* Int32Ty = Builder.getInt32Ty(); 710ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang unsigned minNumElts = std::min(numEltsFrom, numEltsTo); 711ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang unsigned i; 712ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang for (i=0; i != minNumElts; ++i) 713481823aa819ea1dd25567ae616dca93056ef770aMon P Wang Args.push_back(ConstantInt::get(Int32Ty, i)); 714ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang 715ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang if (i < numEltsTo) { 716481823aa819ea1dd25567ae616dca93056ef770aMon P Wang Constant* UnC = UndefValue::get(Int32Ty); 717ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang for (; i != numEltsTo; ++i) 718ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang Args.push_back(UnC); 719ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang } 720ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang Constant *Mask = ConstantVector::get(Args); 721ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang return Builder.CreateShuffleVector(FromVal, UnV, Mask, "tmpV"); 722ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang} 723ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang 7244cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// ConvertScalar_ExtractValue - Extract a value of type ToType from an integer 7254cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// or vector value FromVal, extracting the bits from the offset specified by 7264cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// Offset. This returns the value, which is of type ToType. 7274cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// 7284cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// This happens when we are converting an "integer union" to a single 7294cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// integer scalar, or when we are converting a "vector union" to a vector with 7304cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// insert/extractelement instructions. 7314cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// 7324cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// Offset is an offset from the original alloca, in bits that need to be 7334cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// shifted to the right. 7344cc576bc5ea27951f3bb15ccefbe483293bf8eafChris LattnerValue *ConvertToScalarInfo:: 7354cc576bc5ea27951f3bb15ccefbe483293bf8eafChris LattnerConvertScalar_ExtractValue(Value *FromVal, const Type *ToType, 7364cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t Offset, IRBuilder<> &Builder) { 7374cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If the load is of the whole new alloca, no conversion is needed. 738be0761c8202405cdd33f1103d262c0aa97895a8eMon P Wang const Type *FromType = FromVal->getType(); 739be0761c8202405cdd33f1103d262c0aa97895a8eMon P Wang if (FromType == ToType && Offset == 0) 7404cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return FromVal; 7414cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 7424cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If the result alloca is a vector type, this is either an element 7434cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // access or a bitcast to another vector type of the same size. 744be0761c8202405cdd33f1103d262c0aa97895a8eMon P Wang if (const VectorType *VTy = dyn_cast<VectorType>(FromType)) { 7450398d6135daef709f80837e457a75dc2e1c2aab7Cameron Zwarich unsigned FromTypeSize = TD.getTypeAllocSize(FromType); 7469827b78b51f285e90c2b1e5add9b28d10c88595cCameron Zwarich unsigned ToTypeSize = TD.getTypeAllocSize(ToType); 7470398d6135daef709f80837e457a75dc2e1c2aab7Cameron Zwarich if (FromTypeSize == ToTypeSize) { 748ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang // If the two types have the same primitive size, use a bit cast. 749ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang // Otherwise, it is two vectors with the same element type that has 750ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang // the same allocation size but different number of elements so use 751ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang // a shuffle vector. 752be0761c8202405cdd33f1103d262c0aa97895a8eMon P Wang if (FromType->getPrimitiveSizeInBits() == 753be0761c8202405cdd33f1103d262c0aa97895a8eMon P Wang ToType->getPrimitiveSizeInBits()) 754be0761c8202405cdd33f1103d262c0aa97895a8eMon P Wang return Builder.CreateBitCast(FromVal, ToType, "tmp"); 755ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang else 756ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang return CreateShuffleVectorCast(FromVal, ToType, Builder); 757be0761c8202405cdd33f1103d262c0aa97895a8eMon P Wang } 758032c10fee2a4bb731488ce75844878009d3bd409Cameron Zwarich 7590398d6135daef709f80837e457a75dc2e1c2aab7Cameron Zwarich if (isPowerOf2_64(FromTypeSize / ToTypeSize)) { 760344731c01805aeda49c747bac6148501fa85557cCameron Zwarich assert(!(ToType->isVectorTy() && Offset != 0) && "Can't extract a value " 761344731c01805aeda49c747bac6148501fa85557cCameron Zwarich "of a smaller vector type at a nonzero offset."); 762032c10fee2a4bb731488ce75844878009d3bd409Cameron Zwarich 763344731c01805aeda49c747bac6148501fa85557cCameron Zwarich const Type *CastElementTy = getScaledElementType(FromType, ToType, 7641537ce75ed25bbca58096383bb1fb9dd427bf1aaCameron Zwarich ToTypeSize * 8); 7650398d6135daef709f80837e457a75dc2e1c2aab7Cameron Zwarich unsigned NumCastVectorElements = FromTypeSize / ToTypeSize; 766032c10fee2a4bb731488ce75844878009d3bd409Cameron Zwarich 767032c10fee2a4bb731488ce75844878009d3bd409Cameron Zwarich LLVMContext &Context = FromVal->getContext(); 768032c10fee2a4bb731488ce75844878009d3bd409Cameron Zwarich const Type *CastTy = VectorType::get(CastElementTy, 769032c10fee2a4bb731488ce75844878009d3bd409Cameron Zwarich NumCastVectorElements); 770032c10fee2a4bb731488ce75844878009d3bd409Cameron Zwarich Value *Cast = Builder.CreateBitCast(FromVal, CastTy, "tmp"); 771344731c01805aeda49c747bac6148501fa85557cCameron Zwarich 772344731c01805aeda49c747bac6148501fa85557cCameron Zwarich unsigned EltSize = TD.getTypeAllocSizeInBits(CastElementTy); 773344731c01805aeda49c747bac6148501fa85557cCameron Zwarich unsigned Elt = Offset/EltSize; 774344731c01805aeda49c747bac6148501fa85557cCameron Zwarich assert(EltSize*Elt == Offset && "Invalid modulus in validity checking"); 775032c10fee2a4bb731488ce75844878009d3bd409Cameron Zwarich Value *Extract = Builder.CreateExtractElement(Cast, ConstantInt::get( 776344731c01805aeda49c747bac6148501fa85557cCameron Zwarich Type::getInt32Ty(Context), Elt), "tmp"); 777032c10fee2a4bb731488ce75844878009d3bd409Cameron Zwarich return Builder.CreateBitCast(Extract, ToType, "tmp"); 778b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich } 7794cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 7804cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Otherwise it must be an element access. 7814cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner unsigned Elt = 0; 7824cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Offset) { 7834cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner unsigned EltSize = TD.getTypeAllocSizeInBits(VTy->getElementType()); 7844cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Elt = Offset/EltSize; 7854cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner assert(EltSize*Elt == Offset && "Invalid modulus in validity checking"); 786b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson } 7874cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Return the element extracted out of it. 7884cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *V = Builder.CreateExtractElement(FromVal, ConstantInt::get( 7894cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Type::getInt32Ty(FromVal->getContext()), Elt), "tmp"); 7904cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (V->getType() != ToType) 7914cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner V = Builder.CreateBitCast(V, ToType, "tmp"); 7924cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return V; 7934cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 7946974302e3ff20746268721959efed807c7711bfcBob Wilson 7954cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If ToType is a first class aggregate, extract out each of the pieces and 7964cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // use insertvalue's to form the FCA. 7974cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (const StructType *ST = dyn_cast<StructType>(ToType)) { 7984cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const StructLayout &Layout = *TD.getStructLayout(ST); 7994cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *Res = UndefValue::get(ST); 8004cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (unsigned i = 0, e = ST->getNumElements(); i != e; ++i) { 8014cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *Elt = ConvertScalar_ExtractValue(FromVal, ST->getElementType(i), 8024cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Offset+Layout.getElementOffsetInBits(i), 8034cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Builder); 8044cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Res = Builder.CreateInsertValue(Res, Elt, i, "tmp"); 8054cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 8064cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return Res; 8074cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 8086974302e3ff20746268721959efed807c7711bfcBob Wilson 8094cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (const ArrayType *AT = dyn_cast<ArrayType>(ToType)) { 8104cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t EltSize = TD.getTypeAllocSizeInBits(AT->getElementType()); 8114cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *Res = UndefValue::get(AT); 8124cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (unsigned i = 0, e = AT->getNumElements(); i != e; ++i) { 8134cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *Elt = ConvertScalar_ExtractValue(FromVal, AT->getElementType(), 8144cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Offset+i*EltSize, Builder); 8154cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Res = Builder.CreateInsertValue(Res, Elt, i, "tmp"); 8164cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 8174cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return Res; 818b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson } 8192674089cefe519195e00bdf879647438cfb1cb0fDaniel Dunbar 8204cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Otherwise, this must be a union that was converted to an integer value. 8214cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const IntegerType *NTy = cast<IntegerType>(FromVal->getType()); 822b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson 8234cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If this is a big-endian system and the load is narrower than the 8244cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // full alloca type, we need to do a shift to get the right bits. 8254cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner int ShAmt = 0; 8264cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (TD.isBigEndian()) { 8274cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // On big-endian machines, the lowest bit is stored at the bit offset 8284cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // from the pointer given by getTypeStoreSizeInBits. This matters for 8294cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // integers with a bitwidth that is not a multiple of 8. 8304cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ShAmt = TD.getTypeStoreSizeInBits(NTy) - 8314cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner TD.getTypeStoreSizeInBits(ToType) - Offset; 832b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson } else { 8334cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ShAmt = Offset; 834b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson } 835b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson 8364cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Note: we support negative bitwidths (with shl) which are not defined. 8374cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // We do this to support (f.e.) loads off the end of a structure where 8384cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // only some bits are used. 8394cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (ShAmt > 0 && (unsigned)ShAmt < NTy->getBitWidth()) 8404cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner FromVal = Builder.CreateLShr(FromVal, 8414cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ConstantInt::get(FromVal->getType(), 8424cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ShAmt), "tmp"); 8434cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner else if (ShAmt < 0 && (unsigned)-ShAmt < NTy->getBitWidth()) 8446974302e3ff20746268721959efed807c7711bfcBob Wilson FromVal = Builder.CreateShl(FromVal, 8454cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ConstantInt::get(FromVal->getType(), 8464cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner -ShAmt), "tmp"); 847b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson 8484cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Finally, unconditionally truncate the integer to the right width. 8494cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner unsigned LIBitWidth = TD.getTypeSizeInBits(ToType); 8504cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (LIBitWidth < NTy->getBitWidth()) 8514cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner FromVal = 8526974302e3ff20746268721959efed807c7711bfcBob Wilson Builder.CreateTrunc(FromVal, IntegerType::get(FromVal->getContext(), 8534cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner LIBitWidth), "tmp"); 8544cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner else if (LIBitWidth > NTy->getBitWidth()) 8554cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner FromVal = 8566974302e3ff20746268721959efed807c7711bfcBob Wilson Builder.CreateZExt(FromVal, IntegerType::get(FromVal->getContext(), 8574cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner LIBitWidth), "tmp"); 8584cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 8594cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If the result is an integer, this is a trunc or bitcast. 8604cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (ToType->isIntegerTy()) { 8614cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Should be done. 8624cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else if (ToType->isFloatingPointTy() || ToType->isVectorTy()) { 8634cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Just do a bitcast, we know the sizes match up. 8644cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner FromVal = Builder.CreateBitCast(FromVal, ToType, "tmp"); 8654cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else { 8664cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Otherwise must be a pointer. 8674cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner FromVal = Builder.CreateIntToPtr(FromVal, ToType, "tmp"); 868372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 8694cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner assert(FromVal->getType() == ToType && "Didn't convert right?"); 8704cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return FromVal; 871372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner} 872372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 8734cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// ConvertScalar_InsertValue - Insert the value "SV" into the existing integer 8744cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// or vector value "Old" at the offset specified by Offset. 8754cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// 8764cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// This happens when we are converting an "integer union" to a 8774cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// single integer scalar, or when we are converting a "vector union" to a 8784cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// vector with insert/extractelement instructions. 8794cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// 8804cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// Offset is an offset from the original alloca, in bits that need to be 8814cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// shifted to the right. 8824cc576bc5ea27951f3bb15ccefbe483293bf8eafChris LattnerValue *ConvertToScalarInfo:: 8834cc576bc5ea27951f3bb15ccefbe483293bf8eafChris LattnerConvertScalar_InsertValue(Value *SV, Value *Old, 8844cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t Offset, IRBuilder<> &Builder) { 8854cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Convert the stored type to the actual type, shift it left to insert 8864cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // then 'or' into place. 8874cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const Type *AllocaType = Old->getType(); 8884cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner LLVMContext &Context = Old->getContext(); 8892674089cefe519195e00bdf879647438cfb1cb0fDaniel Dunbar 8904cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (const VectorType *VTy = dyn_cast<VectorType>(AllocaType)) { 8914cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t VecSize = TD.getTypeAllocSizeInBits(VTy); 8924cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t ValSize = TD.getTypeAllocSizeInBits(SV->getType()); 8936974302e3ff20746268721959efed807c7711bfcBob Wilson 8944cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Changing the whole vector with memset or with an access of a different 8954cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // vector type? 896be0761c8202405cdd33f1103d262c0aa97895a8eMon P Wang if (ValSize == VecSize) { 897ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang // If the two types have the same primitive size, use a bit cast. 898ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang // Otherwise, it is two vectors with the same element type that has 899ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang // the same allocation size but different number of elements so use 900ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang // a shuffle vector. 901be0761c8202405cdd33f1103d262c0aa97895a8eMon P Wang if (VTy->getPrimitiveSizeInBits() == 902be0761c8202405cdd33f1103d262c0aa97895a8eMon P Wang SV->getType()->getPrimitiveSizeInBits()) 903be0761c8202405cdd33f1103d262c0aa97895a8eMon P Wang return Builder.CreateBitCast(SV, AllocaType, "tmp"); 904ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang else 905ddf9abf2b6ee3a1104057df20ec3be61b410441eMon P Wang return CreateShuffleVectorCast(SV, VTy, Builder); 906be0761c8202405cdd33f1103d262c0aa97895a8eMon P Wang } 9072674089cefe519195e00bdf879647438cfb1cb0fDaniel Dunbar 908344731c01805aeda49c747bac6148501fa85557cCameron Zwarich if (isPowerOf2_64(VecSize / ValSize)) { 909344731c01805aeda49c747bac6148501fa85557cCameron Zwarich assert(!(SV->getType()->isVectorTy() && Offset != 0) && "Can't insert a " 910344731c01805aeda49c747bac6148501fa85557cCameron Zwarich "value of a smaller vector type at a nonzero offset."); 911b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich 912344731c01805aeda49c747bac6148501fa85557cCameron Zwarich const Type *CastElementTy = getScaledElementType(VTy, SV->getType(), 913344731c01805aeda49c747bac6148501fa85557cCameron Zwarich ValSize); 9141537ce75ed25bbca58096383bb1fb9dd427bf1aaCameron Zwarich unsigned NumCastVectorElements = VecSize / ValSize; 915b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich 916b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich LLVMContext &Context = SV->getContext(); 917b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich const Type *OldCastTy = VectorType::get(CastElementTy, 918b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich NumCastVectorElements); 919b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich Value *OldCast = Builder.CreateBitCast(Old, OldCastTy, "tmp"); 920b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich 921b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich Value *SVCast = Builder.CreateBitCast(SV, CastElementTy, "tmp"); 922344731c01805aeda49c747bac6148501fa85557cCameron Zwarich 923344731c01805aeda49c747bac6148501fa85557cCameron Zwarich unsigned EltSize = TD.getTypeAllocSizeInBits(CastElementTy); 924344731c01805aeda49c747bac6148501fa85557cCameron Zwarich unsigned Elt = Offset/EltSize; 925344731c01805aeda49c747bac6148501fa85557cCameron Zwarich assert(EltSize*Elt == Offset && "Invalid modulus in validity checking"); 926b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich Value *Insert = 927b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich Builder.CreateInsertElement(OldCast, SVCast, ConstantInt::get( 928344731c01805aeda49c747bac6148501fa85557cCameron Zwarich Type::getInt32Ty(Context), Elt), "tmp"); 929b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich return Builder.CreateBitCast(Insert, AllocaType, "tmp"); 930b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich } 931b2fd770136b92637c5f084b743eab29f910288d5Cameron Zwarich 9324cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Must be an element insertion. 933c5c43b958cf2f251c836f94d4499adb6296f0611Cameron Zwarich assert(SV->getType() == VTy->getElementType()); 934c5c43b958cf2f251c836f94d4499adb6296f0611Cameron Zwarich uint64_t EltSize = TD.getTypeAllocSizeInBits(VTy->getElementType()); 9354cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner unsigned Elt = Offset/EltSize; 936c5c43b958cf2f251c836f94d4499adb6296f0611Cameron Zwarich return Builder.CreateInsertElement(Old, SV, 9374cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ConstantInt::get(Type::getInt32Ty(SV->getContext()), Elt), 9384cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner "tmp"); 939b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson } 9406974302e3ff20746268721959efed807c7711bfcBob Wilson 9414cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If SV is a first-class aggregate value, insert each value recursively. 9424cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (const StructType *ST = dyn_cast<StructType>(SV->getType())) { 9434cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const StructLayout &Layout = *TD.getStructLayout(ST); 9444cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (unsigned i = 0, e = ST->getNumElements(); i != e; ++i) { 9454cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *Elt = Builder.CreateExtractValue(SV, i, "tmp"); 9466974302e3ff20746268721959efed807c7711bfcBob Wilson Old = ConvertScalar_InsertValue(Elt, Old, 9474cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Offset+Layout.getElementOffsetInBits(i), 9484cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Builder); 9494cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 9504cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return Old; 9514cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 9526974302e3ff20746268721959efed807c7711bfcBob Wilson 9534cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (const ArrayType *AT = dyn_cast<ArrayType>(SV->getType())) { 9544cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t EltSize = TD.getTypeAllocSizeInBits(AT->getElementType()); 9554cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (unsigned i = 0, e = AT->getNumElements(); i != e; ++i) { 9564cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *Elt = Builder.CreateExtractValue(SV, i, "tmp"); 9574cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Old = ConvertScalar_InsertValue(Elt, Old, Offset+i*EltSize, Builder); 9584cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 9594cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return Old; 9604cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 9614cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 9624cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If SV is a float, convert it to the appropriate integer type. 9634cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If it is a pointer, do the same. 9644cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner unsigned SrcWidth = TD.getTypeSizeInBits(SV->getType()); 9654cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner unsigned DestWidth = TD.getTypeSizeInBits(AllocaType); 9664cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner unsigned SrcStoreWidth = TD.getTypeStoreSizeInBits(SV->getType()); 9674cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner unsigned DestStoreWidth = TD.getTypeStoreSizeInBits(AllocaType); 9684cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (SV->getType()->isFloatingPointTy() || SV->getType()->isVectorTy()) 9694cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SV = Builder.CreateBitCast(SV, 9704cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner IntegerType::get(SV->getContext(),SrcWidth), "tmp"); 9714cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner else if (SV->getType()->isPointerTy()) 9724cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SV = Builder.CreatePtrToInt(SV, TD.getIntPtrType(SV->getContext()), "tmp"); 9734cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 9744cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Zero extend or truncate the value if needed. 9754cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (SV->getType() != AllocaType) { 9764cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (SV->getType()->getPrimitiveSizeInBits() < 9774cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner AllocaType->getPrimitiveSizeInBits()) 9784cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SV = Builder.CreateZExt(SV, AllocaType, "tmp"); 9794cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner else { 9804cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Truncation may be needed if storing more than the alloca can hold 9814cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // (undefined behavior). 9824cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SV = Builder.CreateTrunc(SV, AllocaType, "tmp"); 9834cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SrcWidth = DestWidth; 9844cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SrcStoreWidth = DestStoreWidth; 9854cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 9864cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 9874cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 9884cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If this is a big-endian system and the store is narrower than the 9894cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // full alloca type, we need to do a shift to get the right bits. 9904cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner int ShAmt = 0; 9914cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (TD.isBigEndian()) { 9924cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // On big-endian machines, the lowest bit is stored at the bit offset 9934cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // from the pointer given by getTypeStoreSizeInBits. This matters for 9944cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // integers with a bitwidth that is not a multiple of 8. 9954cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ShAmt = DestStoreWidth - SrcStoreWidth - Offset; 9964cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else { 9974cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ShAmt = Offset; 9984cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 9994cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 10004cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Note: we support negative bitwidths (with shr) which are not defined. 10014cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // We do this to support (f.e.) stores off the end of a structure where 10024cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // only some bits in the structure are set. 10034cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner APInt Mask(APInt::getLowBitsSet(DestWidth, SrcWidth)); 10044cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (ShAmt > 0 && (unsigned)ShAmt < DestWidth) { 10054cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SV = Builder.CreateShl(SV, ConstantInt::get(SV->getType(), 10064cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ShAmt), "tmp"); 10074cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Mask <<= ShAmt; 10084cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else if (ShAmt < 0 && (unsigned)-ShAmt < DestWidth) { 10094cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SV = Builder.CreateLShr(SV, ConstantInt::get(SV->getType(), 10104cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner -ShAmt), "tmp"); 10114cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Mask = Mask.lshr(-ShAmt); 10124cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 10134cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 10144cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Mask out the bits we are about to insert from the old value, and or 10154cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // in the new bits. 10164cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (SrcWidth != DestWidth) { 10174cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner assert(DestWidth > SrcWidth); 10184cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Old = Builder.CreateAnd(Old, ConstantInt::get(Context, ~Mask), "mask"); 10194cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SV = Builder.CreateOr(Old, SV, "ins"); 10204cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 10214cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return SV; 1022b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson} 1023b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson 1024b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson 10254cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner//===----------------------------------------------------------------------===// 10264cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner// SRoA Driver 10274cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner//===----------------------------------------------------------------------===// 1028b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson 1029b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson 10304cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattnerbool SROA::runOnFunction(Function &F) { 10314cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner TD = getAnalysisIfAvailable<TargetData>(); 1032b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson 10334cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner bool Changed = performPromotion(F); 1034b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson 10354cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // FIXME: ScalarRepl currently depends on TargetData more than it 10364cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // theoretically needs to. It should be refactored in order to support 10374cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // target-independent IR. Until this is done, just skip the actual 10384cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // scalar-replacement portion of this pass. 10394cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (!TD) return Changed; 10404cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 10414cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner while (1) { 10424cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner bool LocalChange = performScalarRepl(F); 10434cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (!LocalChange) break; // No need to repromote if no scalarrepl 10444cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Changed = true; 10454cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner LocalChange = performPromotion(F); 10464cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (!LocalChange) break; // No need to re-scalarrepl if no promotion 10472674089cefe519195e00bdf879647438cfb1cb0fDaniel Dunbar } 10484cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 10494cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return Changed; 1050d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner} 1051d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner 1052d0f56132cfa6e25fb9692e84ea12444c86b92ae4Chris Lattnernamespace { 1053d0f56132cfa6e25fb9692e84ea12444c86b92ae4Chris Lattnerclass AllocaPromoter : public LoadAndStorePromoter { 1054d0f56132cfa6e25fb9692e84ea12444c86b92ae4Chris Lattner AllocaInst *AI; 1055d0f56132cfa6e25fb9692e84ea12444c86b92ae4Chris Lattnerpublic: 1056c827939046670a9800659b83e2048f1d3a79a531Cameron Zwarich AllocaPromoter(const SmallVectorImpl<Instruction*> &Insts, SSAUpdater &S, 1057c827939046670a9800659b83e2048f1d3a79a531Cameron Zwarich DbgDeclareInst *DD, DIBuilder *&DB) 1058c827939046670a9800659b83e2048f1d3a79a531Cameron Zwarich : LoadAndStorePromoter(Insts, S, DD, DB), AI(0) {} 1059e0a1a5ba91df6817f9ffae7af65ed0bda66f7620Chris Lattner 1060deaf55f69865bbc997a569c2a689ec5b0fbdefefChris Lattner void run(AllocaInst *AI, const SmallVectorImpl<Instruction*> &Insts) { 1061d0f56132cfa6e25fb9692e84ea12444c86b92ae4Chris Lattner // Remember which alloca we're promoting (for isInstInList). 1062d0f56132cfa6e25fb9692e84ea12444c86b92ae4Chris Lattner this->AI = AI; 1063deaf55f69865bbc997a569c2a689ec5b0fbdefefChris Lattner LoadAndStorePromoter::run(Insts); 1064d0f56132cfa6e25fb9692e84ea12444c86b92ae4Chris Lattner AI->eraseFromParent(); 1065e0a1a5ba91df6817f9ffae7af65ed0bda66f7620Chris Lattner } 1066e0a1a5ba91df6817f9ffae7af65ed0bda66f7620Chris Lattner 1067d0f56132cfa6e25fb9692e84ea12444c86b92ae4Chris Lattner virtual bool isInstInList(Instruction *I, 1068d0f56132cfa6e25fb9692e84ea12444c86b92ae4Chris Lattner const SmallVectorImpl<Instruction*> &Insts) const { 1069d0f56132cfa6e25fb9692e84ea12444c86b92ae4Chris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(I)) 1070d0f56132cfa6e25fb9692e84ea12444c86b92ae4Chris Lattner return LI->getOperand(0) == AI; 1071d0f56132cfa6e25fb9692e84ea12444c86b92ae4Chris Lattner return cast<StoreInst>(I)->getPointerOperand() == AI; 1072e0a1a5ba91df6817f9ffae7af65ed0bda66f7620Chris Lattner } 1073d0f56132cfa6e25fb9692e84ea12444c86b92ae4Chris Lattner}; 1074d0f56132cfa6e25fb9692e84ea12444c86b92ae4Chris Lattner} // end anon namespace 107578c50b8cd68d266d4ed6f8eca443cf8142a01204Bob Wilson 1076c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner/// isSafeSelectToSpeculate - Select instructions that use an alloca and are 1077c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner/// subsequently loaded can be rewritten to load both input pointers and then 1078c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner/// select between the result, allowing the load of the alloca to be promoted. 1079c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner/// From this: 1080c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner/// %P2 = select i1 %cond, i32* %Alloca, i32* %Other 1081c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner/// %V = load i32* %P2 1082c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner/// to: 1083c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner/// %V1 = load i32* %Alloca -> will be mem2reg'd 1084c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner/// %V2 = load i32* %Other 1085e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner/// %V = select i1 %cond, i32 %V1, i32 %V2 1086c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner/// 1087c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner/// We can do this to a select if its only uses are loads and if the operand to 1088c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner/// the select can be loaded unconditionally. 1089c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattnerstatic bool isSafeSelectToSpeculate(SelectInst *SI, const TargetData *TD) { 1090c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner bool TDerefable = SI->getTrueValue()->isDereferenceablePointer(); 1091c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner bool FDerefable = SI->getFalseValue()->isDereferenceablePointer(); 1092c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner 1093c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner for (Value::use_iterator UI = SI->use_begin(), UE = SI->use_end(); 1094c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner UI != UE; ++UI) { 1095c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner LoadInst *LI = dyn_cast<LoadInst>(*UI); 1096c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner if (LI == 0 || LI->isVolatile()) return false; 1097c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner 1098e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // Both operands to the select need to be dereferencable, either absolutely 1099c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner // (e.g. allocas) or at this point because we can see other accesses to it. 1100c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner if (!TDerefable && !isSafeToLoadUnconditionally(SI->getTrueValue(), LI, 1101c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner LI->getAlignment(), TD)) 1102c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner return false; 1103c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner if (!FDerefable && !isSafeToLoadUnconditionally(SI->getFalseValue(), LI, 1104c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner LI->getAlignment(), TD)) 1105c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner return false; 1106c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner } 1107c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner 1108c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner return true; 1109c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner} 1110c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner 1111e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner/// isSafePHIToSpeculate - PHI instructions that use an alloca and are 1112e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner/// subsequently loaded can be rewritten to load both input pointers in the pred 1113e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner/// blocks and then PHI the results, allowing the load of the alloca to be 1114e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner/// promoted. 1115e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner/// From this: 1116e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner/// %P2 = phi [i32* %Alloca, i32* %Other] 1117e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner/// %V = load i32* %P2 1118e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner/// to: 1119e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner/// %V1 = load i32* %Alloca -> will be mem2reg'd 1120e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner/// ... 1121e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner/// %V2 = load i32* %Other 1122e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner/// ... 1123e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner/// %V = phi [i32 %V1, i32 %V2] 1124e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner/// 1125e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner/// We can do this to a select if its only uses are loads and if the operand to 1126e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner/// the select can be loaded unconditionally. 1127e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattnerstatic bool isSafePHIToSpeculate(PHINode *PN, const TargetData *TD) { 1128e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // For now, we can only do this promotion if the load is in the same block as 1129e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // the PHI, and if there are no stores between the phi and load. 1130e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // TODO: Allow recursive phi users. 1131e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // TODO: Allow stores. 1132e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner BasicBlock *BB = PN->getParent(); 1133e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner unsigned MaxAlign = 0; 1134e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner for (Value::use_iterator UI = PN->use_begin(), UE = PN->use_end(); 1135e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner UI != UE; ++UI) { 1136e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner LoadInst *LI = dyn_cast<LoadInst>(*UI); 1137e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner if (LI == 0 || LI->isVolatile()) return false; 1138e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1139e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // For now we only allow loads in the same block as the PHI. This is a 1140e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // common case that happens when instcombine merges two loads through a PHI. 1141e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner if (LI->getParent() != BB) return false; 1142e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1143e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // Ensure that there are no instructions between the PHI and the load that 1144e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // could store. 1145e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner for (BasicBlock::iterator BBI = PN; &*BBI != LI; ++BBI) 1146e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner if (BBI->mayWriteToMemory()) 1147e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner return false; 1148e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1149e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner MaxAlign = std::max(MaxAlign, LI->getAlignment()); 1150e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner } 1151e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1152e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // Okay, we know that we have one or more loads in the same block as the PHI. 1153e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // We can transform this if it is safe to push the loads into the predecessor 1154e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // blocks. The only thing to watch out for is that we can't put a possibly 1155e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // trapping load in the predecessor if it is a critical edge. 1156e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { 1157e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner BasicBlock *Pred = PN->getIncomingBlock(i); 1158e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1159e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // If the predecessor has a single successor, then the edge isn't critical. 1160e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner if (Pred->getTerminator()->getNumSuccessors() == 1) 1161e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner continue; 1162e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1163e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner Value *InVal = PN->getIncomingValue(i); 1164e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1165e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // If the InVal is an invoke in the pred, we can't put a load on the edge. 1166e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner if (InvokeInst *II = dyn_cast<InvokeInst>(InVal)) 1167e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner if (II->getParent() == Pred) 1168e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner return false; 1169e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1170e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // If this pointer is always safe to load, or if we can prove that there is 1171e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // already a load in the block, then we can move the load to the pred block. 1172e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner if (InVal->isDereferenceablePointer() || 1173e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner isSafeToLoadUnconditionally(InVal, Pred->getTerminator(), MaxAlign, TD)) 1174e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner continue; 1175e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1176e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner return false; 1177e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner } 1178e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1179e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner return true; 1180e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner} 1181e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1182c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner 1183c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner/// tryToMakeAllocaBePromotable - This returns true if the alloca only has 1184c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner/// direct (non-volatile) loads and stores to it. If the alloca is close but 1185c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner/// not quite there, this will transform the code to allow promotion. As such, 1186c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner/// it is a non-pure predicate. 1187c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattnerstatic bool tryToMakeAllocaBePromotable(AllocaInst *AI, const TargetData *TD) { 1188c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner SetVector<Instruction*, SmallVector<Instruction*, 4>, 1189c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner SmallPtrSet<Instruction*, 4> > InstsToRewrite; 1190c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner 1191c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner for (Value::use_iterator UI = AI->use_begin(), UE = AI->use_end(); 1192c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner UI != UE; ++UI) { 1193c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner User *U = *UI; 1194c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(U)) { 1195c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner if (LI->isVolatile()) 1196c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner return false; 1197c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner continue; 1198c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner } 1199c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner 1200c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner if (StoreInst *SI = dyn_cast<StoreInst>(U)) { 1201c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner if (SI->getOperand(0) == AI || SI->isVolatile()) 1202c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner return false; // Don't allow a store OF the AI, only INTO the AI. 1203c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner continue; 1204c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner } 1205c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner 1206c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner if (SelectInst *SI = dyn_cast<SelectInst>(U)) { 1207c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner // If the condition being selected on is a constant, fold the select, yes 1208c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner // this does (rarely) happen early on. 1209c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner if (ConstantInt *CI = dyn_cast<ConstantInt>(SI->getCondition())) { 1210c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner Value *Result = SI->getOperand(1+CI->isZero()); 1211c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner SI->replaceAllUsesWith(Result); 1212c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner SI->eraseFromParent(); 1213c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner 1214c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner // This is very rare and we just scrambled the use list of AI, start 1215c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner // over completely. 1216c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner return tryToMakeAllocaBePromotable(AI, TD); 1217c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner } 1218c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner 1219c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner // If it is safe to turn "load (select c, AI, ptr)" into a select of two 1220c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner // loads, then we can transform this by rewriting the select. 1221c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner if (!isSafeSelectToSpeculate(SI, TD)) 1222c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner return false; 1223c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner 1224c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner InstsToRewrite.insert(SI); 1225c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner continue; 1226c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner } 1227c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner 1228e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner if (PHINode *PN = dyn_cast<PHINode>(U)) { 1229e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner if (PN->use_empty()) { // Dead PHIs can be stripped. 1230e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner InstsToRewrite.insert(PN); 1231e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner continue; 1232e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner } 1233e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1234e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // If it is safe to turn "load (phi [AI, ptr, ...])" into a PHI of loads 1235e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // in the pred blocks, then we can transform this by rewriting the PHI. 1236e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner if (!isSafePHIToSpeculate(PN, TD)) 1237e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner return false; 1238e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1239e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner InstsToRewrite.insert(PN); 1240e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner continue; 1241e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner } 1242e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1243c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner return false; 1244c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner } 1245c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner 1246c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner // If there are no instructions to rewrite, then all uses are load/stores and 1247c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner // we're done! 1248c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner if (InstsToRewrite.empty()) 1249c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner return true; 1250c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner 1251c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner // If we have instructions that need to be rewritten for this to be promotable 1252c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner // take care of it now. 1253c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner for (unsigned i = 0, e = InstsToRewrite.size(); i != e; ++i) { 1254e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner if (SelectInst *SI = dyn_cast<SelectInst>(InstsToRewrite[i])) { 1255e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // Selects in InstsToRewrite only have load uses. Rewrite each as two 1256e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // loads with a new select. 1257e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner while (!SI->use_empty()) { 1258e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner LoadInst *LI = cast<LoadInst>(SI->use_back()); 1259c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner 1260e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner IRBuilder<> Builder(LI); 1261e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner LoadInst *TrueLoad = 1262e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner Builder.CreateLoad(SI->getTrueValue(), LI->getName()+".t"); 1263e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner LoadInst *FalseLoad = 1264e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner Builder.CreateLoad(SI->getFalseValue(), LI->getName()+".t"); 1265e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1266e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // Transfer alignment and TBAA info if present. 1267e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner TrueLoad->setAlignment(LI->getAlignment()); 1268e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner FalseLoad->setAlignment(LI->getAlignment()); 1269e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner if (MDNode *Tag = LI->getMetadata(LLVMContext::MD_tbaa)) { 1270e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner TrueLoad->setMetadata(LLVMContext::MD_tbaa, Tag); 1271e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner FalseLoad->setMetadata(LLVMContext::MD_tbaa, Tag); 1272e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner } 1273e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1274e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner Value *V = Builder.CreateSelect(SI->getCondition(), TrueLoad, FalseLoad); 1275e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner V->takeName(LI); 1276e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner LI->replaceAllUsesWith(V); 1277e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner LI->eraseFromParent(); 1278c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner } 1279e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1280e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // Now that all the loads are gone, the select is gone too. 1281e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner SI->eraseFromParent(); 1282e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner continue; 1283e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner } 1284e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1285e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // Otherwise, we have a PHI node which allows us to push the loads into the 1286e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // predecessors. 1287e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner PHINode *PN = cast<PHINode>(InstsToRewrite[i]); 1288e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner if (PN->use_empty()) { 1289e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner PN->eraseFromParent(); 1290e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner continue; 1291e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner } 1292e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1293e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner const Type *LoadTy = cast<PointerType>(PN->getType())->getElementType(); 12943ecfc861b4365f341c5c969b40e1afccde676e6fJay Foad PHINode *NewPN = PHINode::Create(LoadTy, PN->getNumIncomingValues(), 12953ecfc861b4365f341c5c969b40e1afccde676e6fJay Foad PN->getName()+".ld", PN); 1296e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1297e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // Get the TBAA tag and alignment to use from one of the loads. It doesn't 1298e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // matter which one we get and if any differ, it doesn't matter. 1299e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner LoadInst *SomeLoad = cast<LoadInst>(PN->use_back()); 1300e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner MDNode *TBAATag = SomeLoad->getMetadata(LLVMContext::MD_tbaa); 1301e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner unsigned Align = SomeLoad->getAlignment(); 1302e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1303e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // Rewrite all loads of the PN to use the new PHI. 1304e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner while (!PN->use_empty()) { 1305e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner LoadInst *LI = cast<LoadInst>(PN->use_back()); 1306e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner LI->replaceAllUsesWith(NewPN); 1307c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner LI->eraseFromParent(); 1308c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner } 1309c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner 1310e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // Inject loads into all of the pred blocks. Keep track of which blocks we 1311e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner // insert them into in case we have multiple edges from the same block. 1312e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner DenseMap<BasicBlock*, LoadInst*> InsertedLoads; 1313e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1314e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { 1315e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner BasicBlock *Pred = PN->getIncomingBlock(i); 1316e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner LoadInst *&Load = InsertedLoads[Pred]; 1317e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner if (Load == 0) { 1318e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner Load = new LoadInst(PN->getIncomingValue(i), 1319e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner PN->getName() + "." + Pred->getName(), 1320e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner Pred->getTerminator()); 1321e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner Load->setAlignment(Align); 1322e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner if (TBAATag) Load->setMetadata(LLVMContext::MD_tbaa, TBAATag); 1323e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner } 1324e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1325e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner NewPN->addIncoming(Load, Pred); 1326e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner } 1327e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner 1328e3357863aaabe297c5fa819d083f2308ebb5f2c2Chris Lattner PN->eraseFromParent(); 1329c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner } 1330c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner 1331c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner ++NumAdjusted; 1332c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner return true; 1333c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner} 1334c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner 13354cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattnerbool SROA::performPromotion(Function &F) { 13364cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner std::vector<AllocaInst*> Allocas; 1337e0a1a5ba91df6817f9ffae7af65ed0bda66f7620Chris Lattner DominatorTree *DT = 0; 1338b1686c32fc694636cbf15a59b23b2a741b65ecf4Cameron Zwarich if (HasDomTree) 1339e0a1a5ba91df6817f9ffae7af65ed0bda66f7620Chris Lattner DT = &getAnalysis<DominatorTree>(); 1340b742defa0a8f3e477c3ed641da49aab276937556Bob Wilson 13414cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner BasicBlock &BB = F.getEntryBlock(); // Get the entry node for the function 1342372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 13434cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner bool Changed = false; 1344deaf55f69865bbc997a569c2a689ec5b0fbdefefChris Lattner SmallVector<Instruction*, 64> Insts; 1345c827939046670a9800659b83e2048f1d3a79a531Cameron Zwarich DIBuilder *DIB = 0; 13464cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner while (1) { 13474cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Allocas.clear(); 13484cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 13494cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Find allocas that are safe to promote, by looking at all instructions in 13504cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // the entry node 13514cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (BasicBlock::iterator I = BB.begin(), E = --BB.end(); I != E; ++I) 13524cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) // Is it an alloca? 1353c87c50a39c1bc27437352feee0f6aba2d50fa1b5Chris Lattner if (tryToMakeAllocaBePromotable(AI, TD)) 13544cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Allocas.push_back(AI); 13554cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 13564cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Allocas.empty()) break; 13574cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 1358b1686c32fc694636cbf15a59b23b2a741b65ecf4Cameron Zwarich if (HasDomTree) 1359419e8a62997987e0509efe721c1ea81ac29f09f3Cameron Zwarich PromoteMemToReg(Allocas, *DT); 1360e0a1a5ba91df6817f9ffae7af65ed0bda66f7620Chris Lattner else { 1361e0a1a5ba91df6817f9ffae7af65ed0bda66f7620Chris Lattner SSAUpdater SSA; 1362deaf55f69865bbc997a569c2a689ec5b0fbdefefChris Lattner for (unsigned i = 0, e = Allocas.size(); i != e; ++i) { 1363deaf55f69865bbc997a569c2a689ec5b0fbdefefChris Lattner AllocaInst *AI = Allocas[i]; 1364deaf55f69865bbc997a569c2a689ec5b0fbdefefChris Lattner 1365deaf55f69865bbc997a569c2a689ec5b0fbdefefChris Lattner // Build list of instructions to promote. 1366deaf55f69865bbc997a569c2a689ec5b0fbdefefChris Lattner for (Value::use_iterator UI = AI->use_begin(), E = AI->use_end(); 1367deaf55f69865bbc997a569c2a689ec5b0fbdefefChris Lattner UI != E; ++UI) 1368deaf55f69865bbc997a569c2a689ec5b0fbdefefChris Lattner Insts.push_back(cast<Instruction>(*UI)); 1369c827939046670a9800659b83e2048f1d3a79a531Cameron Zwarich 1370c827939046670a9800659b83e2048f1d3a79a531Cameron Zwarich DbgDeclareInst *DDI = FindAllocaDbgDeclare(AI); 137113a16083abcdacf2ee44ae95b084f87937ea9aceCameron Zwarich if (DDI && !DIB) 137213a16083abcdacf2ee44ae95b084f87937ea9aceCameron Zwarich DIB = new DIBuilder(*AI->getParent()->getParent()->getParent()); 1373c827939046670a9800659b83e2048f1d3a79a531Cameron Zwarich AllocaPromoter(Insts, SSA, DDI, DIB).run(AI, Insts); 1374deaf55f69865bbc997a569c2a689ec5b0fbdefefChris Lattner Insts.clear(); 1375deaf55f69865bbc997a569c2a689ec5b0fbdefefChris Lattner } 1376e0a1a5ba91df6817f9ffae7af65ed0bda66f7620Chris Lattner } 13774cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner NumPromoted += Allocas.size(); 13784cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Changed = true; 13794cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 13804cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 1381c827939046670a9800659b83e2048f1d3a79a531Cameron Zwarich // FIXME: Is there a better way to handle the lazy initialization of DIB 1382c827939046670a9800659b83e2048f1d3a79a531Cameron Zwarich // so that there doesn't need to be an explicit delete? 1383c827939046670a9800659b83e2048f1d3a79a531Cameron Zwarich delete DIB; 1384c827939046670a9800659b83e2048f1d3a79a531Cameron Zwarich 13854cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return Changed; 13864cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner} 13874cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 13884cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 13894cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// ShouldAttemptScalarRepl - Decide if an alloca is a good candidate for 13904cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// SROA. It must be a struct or array type with a small number of elements. 13914cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattnerstatic bool ShouldAttemptScalarRepl(AllocaInst *AI) { 13924cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const Type *T = AI->getAllocatedType(); 13934cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Do not promote any struct into more than 32 separate vars. 13944cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (const StructType *ST = dyn_cast<StructType>(T)) 13954cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return ST->getNumElements() <= 32; 13964cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Arrays are much less likely to be safe for SROA; only consider 13974cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // them if they are very small. 13984cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (const ArrayType *AT = dyn_cast<ArrayType>(T)) 13994cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return AT->getNumElements() <= 8; 14004cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return false; 14014cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner} 14024cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 14034cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 14044cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner// performScalarRepl - This algorithm is a simple worklist driven algorithm, 14054cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner// which runs on all of the malloc/alloca instructions in the function, removing 14064cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner// them if they are only used by getelementptr instructions. 14074cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner// 14084cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattnerbool SROA::performScalarRepl(Function &F) { 14094cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner std::vector<AllocaInst*> WorkList; 14104cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 14114cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Scan the entry basic block, adding allocas to the worklist. 14124cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner BasicBlock &BB = F.getEntryBlock(); 14134cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E; ++I) 14144cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (AllocaInst *A = dyn_cast<AllocaInst>(I)) 14154cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner WorkList.push_back(A); 14164cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 14174cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Process the worklist 14184cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner bool Changed = false; 14194cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner while (!WorkList.empty()) { 14204cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner AllocaInst *AI = WorkList.back(); 14214cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner WorkList.pop_back(); 14226974302e3ff20746268721959efed807c7711bfcBob Wilson 14234cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Handle dead allocas trivially. These can be formed by SROA'ing arrays 14244cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // with unused elements. 14254cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (AI->use_empty()) { 14264cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner AI->eraseFromParent(); 14274cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Changed = true; 14284cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner continue; 1429d93afec1dbbb1abb3df55e2e007b5f256d09f84aChris Lattner } 14304cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 14314cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If this alloca is impossible for us to promote, reject it early. 14324cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (AI->isArrayAllocation() || !AI->getAllocatedType()->isSized()) 14334cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner continue; 14346974302e3ff20746268721959efed807c7711bfcBob Wilson 14354cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Check to see if this allocation is only modified by a memcpy/memmove from 14364cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // a constant global. If this is the case, we can change all users to use 14374cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // the constant global instead. This is commonly produced by the CFE by 14384cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // constructs like "void foo() { int A[] = {1,2,3,4,5,6,7,8,9...}; }" if 'A' 14394cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // is only subsequently read. 14404cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (MemTransferInst *TheCopy = isOnlyCopiedFromConstantGlobal(AI)) { 14414cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner DEBUG(dbgs() << "Found alloca equal to global: " << *AI << '\n'); 14424cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner DEBUG(dbgs() << " memcpy = " << *TheCopy << '\n'); 14434cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Constant *TheSrc = cast<Constant>(TheCopy->getSource()); 14444cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner AI->replaceAllUsesWith(ConstantExpr::getBitCast(TheSrc, AI->getType())); 14454cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner TheCopy->eraseFromParent(); // Don't mutate the global. 14464cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner AI->eraseFromParent(); 14474cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ++NumGlobals; 14484cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Changed = true; 14494cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner continue; 14504cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 14516974302e3ff20746268721959efed807c7711bfcBob Wilson 14524cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Check to see if we can perform the core SROA transformation. We cannot 14534cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // transform the allocation instruction if it is an array allocation 14544cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // (allocations OF arrays are ok though), and an allocation of a scalar 14554cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // value cannot be decomposed at all. 14564cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t AllocaSize = TD->getTypeAllocSize(AI->getAllocatedType()); 145744118f0e25c25fedda1ccdd6a72f072c0b5c96e7Dan Gohman 14584cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Do not promote [0 x %struct]. 14594cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (AllocaSize == 0) continue; 14606974302e3ff20746268721959efed807c7711bfcBob Wilson 14614cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Do not promote any struct whose size is too big. 14624cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (AllocaSize > SRThreshold) continue; 14636974302e3ff20746268721959efed807c7711bfcBob Wilson 14644cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If the alloca looks like a good candidate for scalar replacement, and if 14654cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // all its users can be transformed, then split up the aggregate into its 14664cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // separate elements. 14674cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (ShouldAttemptScalarRepl(AI) && isSafeAllocaToScalarRepl(AI)) { 14684cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner DoScalarReplacement(AI, WorkList); 14694cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Changed = true; 14704cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner continue; 147120adc9dc4650313f017b27d9818eb2176238113dMon P Wang } 14724cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 14734cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If we can turn this aggregate value (potentially with casts) into a 14744cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // simple scalar value that can be mem2reg'd into a register value. 14754cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // IsNotTrivial tracks whether this is something that mem2reg could have 14764cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // promoted itself. If so, we don't want to transform it needlessly. Note 14774cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // that we can't just check based on the type: the alloca may be of an i32 14784cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // but that has pointer arithmetic to set byte 3 of it or something. 14794cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (AllocaInst *NewAI = 14804cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ConvertToScalarInfo((unsigned)AllocaSize, *TD).TryConvert(AI)) { 14814cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner NewAI->takeName(AI); 14824cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner AI->eraseFromParent(); 14834cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ++NumConverted; 14844cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Changed = true; 14854cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner continue; 14866974302e3ff20746268721959efed807c7711bfcBob Wilson } 14876974302e3ff20746268721959efed807c7711bfcBob Wilson 14884cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Otherwise, couldn't process this alloca. 1489372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 14904cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 14914cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return Changed; 1492372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner} 1493d2fa781169175b827e50953a1d0b7edc6b0c4801Chris Lattner 14944cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// DoScalarReplacement - This alloca satisfied the isSafeAllocaToScalarRepl 14954cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// predicate, do SROA now. 14966974302e3ff20746268721959efed807c7711bfcBob Wilsonvoid SROA::DoScalarReplacement(AllocaInst *AI, 14974cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner std::vector<AllocaInst*> &WorkList) { 14984cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner DEBUG(dbgs() << "Found inst to SROA: " << *AI << '\n'); 14994cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SmallVector<AllocaInst*, 32> ElementAllocas; 15004cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (const StructType *ST = dyn_cast<StructType>(AI->getAllocatedType())) { 15014cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ElementAllocas.reserve(ST->getNumContainedTypes()); 15024cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (unsigned i = 0, e = ST->getNumContainedTypes(); i != e; ++i) { 15036974302e3ff20746268721959efed807c7711bfcBob Wilson AllocaInst *NA = new AllocaInst(ST->getContainedType(i), 0, 15044cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner AI->getAlignment(), 15054cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner AI->getName() + "." + Twine(i), AI); 15064cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ElementAllocas.push_back(NA); 15074cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner WorkList.push_back(NA); // Add to worklist for recursive processing 15084cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 15094cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else { 15104cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const ArrayType *AT = cast<ArrayType>(AI->getAllocatedType()); 15114cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ElementAllocas.reserve(AT->getNumElements()); 15124cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const Type *ElTy = AT->getElementType(); 15134cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (unsigned i = 0, e = AT->getNumElements(); i != e; ++i) { 15144cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner AllocaInst *NA = new AllocaInst(ElTy, 0, AI->getAlignment(), 15154cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner AI->getName() + "." + Twine(i), AI); 15164cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ElementAllocas.push_back(NA); 15174cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner WorkList.push_back(NA); // Add to worklist for recursive processing 15184cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 15194cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 1520d2fa781169175b827e50953a1d0b7edc6b0c4801Chris Lattner 15214cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Now that we have created the new alloca instructions, rewrite all the 15224cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // uses of the old alloca. 15234cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner RewriteForScalarRepl(AI, AI, 0, ElementAllocas); 1524d2fa781169175b827e50953a1d0b7edc6b0c4801Chris Lattner 15254cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Now erase any instructions that were made dead while rewriting the alloca. 15264cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner DeleteDeadInstructions(); 15274cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner AI->eraseFromParent(); 15284cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 1529fe60104ac97f3a8736dcfbfdf9547c7b7cc7b951Dan Gohman ++NumReplaced; 15304cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner} 15314cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 15324cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// DeleteDeadInstructions - Erase instructions on the DeadInstrs list, 15334cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// recursively including all their operands that become trivially dead. 15344cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattnervoid SROA::DeleteDeadInstructions() { 15354cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner while (!DeadInsts.empty()) { 15364cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Instruction *I = cast<Instruction>(DeadInsts.pop_back_val()); 15374cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 15384cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (User::op_iterator OI = I->op_begin(), E = I->op_end(); OI != E; ++OI) 15394cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Instruction *U = dyn_cast<Instruction>(*OI)) { 15404cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Zero out the operand and see if it becomes trivially dead. 15414cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // (But, don't add allocas to the dead instruction list -- they are 15424cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // already on the worklist and will be deleted separately.) 15434cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner *OI = 0; 15444cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (isInstructionTriviallyDead(U) && !isa<AllocaInst>(U)) 15454cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner DeadInsts.push_back(U); 1546d2fa781169175b827e50953a1d0b7edc6b0c4801Chris Lattner } 1547d2fa781169175b827e50953a1d0b7edc6b0c4801Chris Lattner 15484cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner I->eraseFromParent(); 15494cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 15504cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner} 15516974302e3ff20746268721959efed807c7711bfcBob Wilson 15524cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// isSafeForScalarRepl - Check if instruction I is a safe use with regard to 15534cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// performing scalar replacement of alloca AI. The results are flagged in 15544cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// the Info parameter. Offset indicates the position within AI that is 15554cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// referenced by this instruction. 15566c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattnervoid SROA::isSafeForScalarRepl(Instruction *I, uint64_t Offset, 15574cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner AllocaInfo &Info) { 15584cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI!=E; ++UI) { 15594cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Instruction *User = cast<Instruction>(*UI); 15604cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 15614cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (BitCastInst *BC = dyn_cast<BitCastInst>(User)) { 15626c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattner isSafeForScalarRepl(BC, Offset, Info); 15634cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(User)) { 15644cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t GEPOffset = Offset; 15656c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattner isSafeGEP(GEPI, GEPOffset, Info); 15664cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (!Info.isUnsafe) 15676c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattner isSafeForScalarRepl(GEPI, GEPOffset, Info); 156819101c7585c191376d898e3e66e35acd9bd777c2Gabor Greif } else if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(User)) { 15694cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ConstantInt *Length = dyn_cast<ConstantInt>(MI->getLength()); 1570d01a0da090407762fe3b770d84f049d72d06467eChris Lattner if (Length == 0) 1571d01a0da090407762fe3b770d84f049d72d06467eChris Lattner return MarkUnsafe(Info, User); 15726c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattner isSafeMemAccess(Offset, Length->getZExtValue(), 0, 1573145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner UI.getOperandNo() == 0, Info, MI, 1574145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner true /*AllowWholeAccess*/); 15754cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else if (LoadInst *LI = dyn_cast<LoadInst>(User)) { 1576d01a0da090407762fe3b770d84f049d72d06467eChris Lattner if (LI->isVolatile()) 1577d01a0da090407762fe3b770d84f049d72d06467eChris Lattner return MarkUnsafe(Info, User); 1578d01a0da090407762fe3b770d84f049d72d06467eChris Lattner const Type *LIType = LI->getType(); 15796c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattner isSafeMemAccess(Offset, TD->getTypeAllocSize(LIType), 1580145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner LIType, false, Info, LI, true /*AllowWholeAccess*/); 1581d01a0da090407762fe3b770d84f049d72d06467eChris Lattner Info.hasALoadOrStore = true; 1582d01a0da090407762fe3b770d84f049d72d06467eChris Lattner 15834cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else if (StoreInst *SI = dyn_cast<StoreInst>(User)) { 15844cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Store is ok if storing INTO the pointer, not storing the pointer 1585d01a0da090407762fe3b770d84f049d72d06467eChris Lattner if (SI->isVolatile() || SI->getOperand(0) == I) 1586d01a0da090407762fe3b770d84f049d72d06467eChris Lattner return MarkUnsafe(Info, User); 1587d01a0da090407762fe3b770d84f049d72d06467eChris Lattner 1588d01a0da090407762fe3b770d84f049d72d06467eChris Lattner const Type *SIType = SI->getOperand(0)->getType(); 15896c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattner isSafeMemAccess(Offset, TD->getTypeAllocSize(SIType), 1590145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner SIType, true, Info, SI, true /*AllowWholeAccess*/); 1591145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner Info.hasALoadOrStore = true; 1592145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner } else if (isa<PHINode>(User) || isa<SelectInst>(User)) { 1593145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner isSafePHISelectUseForScalarRepl(User, Offset, Info); 1594145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner } else { 1595145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner return MarkUnsafe(Info, User); 1596145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner } 1597145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner if (Info.isUnsafe) return; 1598145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner } 1599145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner} 1600145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner 1601145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner 1602145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner/// isSafePHIUseForScalarRepl - If we see a PHI node or select using a pointer 1603145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner/// derived from the alloca, we can often still split the alloca into elements. 1604145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner/// This is useful if we have a large alloca where one element is phi'd 1605145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner/// together somewhere: we can SRoA and promote all the other elements even if 1606145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner/// we end up not being able to promote this one. 1607145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner/// 1608145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner/// All we require is that the uses of the PHI do not index into other parts of 1609145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner/// the alloca. The most important use case for this is single load and stores 1610145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner/// that are PHI'd together, which can happen due to code sinking. 1611145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattnervoid SROA::isSafePHISelectUseForScalarRepl(Instruction *I, uint64_t Offset, 1612145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner AllocaInfo &Info) { 1613145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner // If we've already checked this PHI, don't do it again. 1614145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner if (PHINode *PN = dyn_cast<PHINode>(I)) 1615145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner if (!Info.CheckedPHIs.insert(PN)) 1616145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner return; 1617145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner 1618145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI!=E; ++UI) { 1619145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner Instruction *User = cast<Instruction>(*UI); 1620145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner 1621145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner if (BitCastInst *BC = dyn_cast<BitCastInst>(User)) { 1622145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner isSafePHISelectUseForScalarRepl(BC, Offset, Info); 1623145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner } else if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(User)) { 1624145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner // Only allow "bitcast" GEPs for simplicity. We could generalize this, 1625145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner // but would have to prove that we're staying inside of an element being 1626145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner // promoted. 1627145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner if (!GEPI->hasAllZeroIndices()) 1628145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner return MarkUnsafe(Info, User); 1629145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner isSafePHISelectUseForScalarRepl(GEPI, Offset, Info); 1630145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner } else if (LoadInst *LI = dyn_cast<LoadInst>(User)) { 1631145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner if (LI->isVolatile()) 1632145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner return MarkUnsafe(Info, User); 1633145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner const Type *LIType = LI->getType(); 1634145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner isSafeMemAccess(Offset, TD->getTypeAllocSize(LIType), 1635145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner LIType, false, Info, LI, false /*AllowWholeAccess*/); 1636145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner Info.hasALoadOrStore = true; 1637145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner 1638145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner } else if (StoreInst *SI = dyn_cast<StoreInst>(User)) { 1639145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner // Store is ok if storing INTO the pointer, not storing the pointer 1640145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner if (SI->isVolatile() || SI->getOperand(0) == I) 1641145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner return MarkUnsafe(Info, User); 1642145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner 1643145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner const Type *SIType = SI->getOperand(0)->getType(); 1644145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner isSafeMemAccess(Offset, TD->getTypeAllocSize(SIType), 1645145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner SIType, true, Info, SI, false /*AllowWholeAccess*/); 1646d01a0da090407762fe3b770d84f049d72d06467eChris Lattner Info.hasALoadOrStore = true; 1647145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner } else if (isa<PHINode>(User) || isa<SelectInst>(User)) { 1648145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner isSafePHISelectUseForScalarRepl(User, Offset, Info); 16494cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else { 1650d01a0da090407762fe3b770d84f049d72d06467eChris Lattner return MarkUnsafe(Info, User); 1651d2fa781169175b827e50953a1d0b7edc6b0c4801Chris Lattner } 16524cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Info.isUnsafe) return; 1653d2fa781169175b827e50953a1d0b7edc6b0c4801Chris Lattner } 1654d2fa781169175b827e50953a1d0b7edc6b0c4801Chris Lattner} 1655d2fa781169175b827e50953a1d0b7edc6b0c4801Chris Lattner 16564cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// isSafeGEP - Check if a GEP instruction can be handled for scalar 16574cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// replacement. It is safe when all the indices are constant, in-bounds 16584cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// references, and when the resulting offset corresponds to an element within 16594cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// the alloca type. The results are flagged in the Info parameter. Upon 16604cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// return, Offset is adjusted as specified by the GEP indices. 16616c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattnervoid SROA::isSafeGEP(GetElementPtrInst *GEPI, 16624cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t &Offset, AllocaInfo &Info) { 16634cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner gep_type_iterator GEPIt = gep_type_begin(GEPI), E = gep_type_end(GEPI); 16644cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (GEPIt == E) 16654cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return; 16665ffe6acd577696a41932c7b82db06a04687e07baChris Lattner 16674cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Walk through the GEP type indices, checking the types that this indexes 16684cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // into. 16694cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (; GEPIt != E; ++GEPIt) { 16704cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Ignore struct elements, no extra checking needed for these. 16714cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if ((*GEPIt)->isStructTy()) 16724cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner continue; 16735ffe6acd577696a41932c7b82db06a04687e07baChris Lattner 16744cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ConstantInt *IdxVal = dyn_cast<ConstantInt>(GEPIt.getOperand()); 16754cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (!IdxVal) 1676d01a0da090407762fe3b770d84f049d72d06467eChris Lattner return MarkUnsafe(Info, GEPI); 16775ffe6acd577696a41932c7b82db06a04687e07baChris Lattner } 167841b33f437f70dcf63e35d08e5f4202258ef05c15Eli Friedman 16794cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Compute the offset due to this GEP and check if the alloca has a 16804cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // component element at that offset. 16814cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SmallVector<Value*, 8> Indices(GEPI->op_begin() + 1, GEPI->op_end()); 16824cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Offset += TD->getIndexedOffset(GEPI->getPointerOperandType(), 16834cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner &Indices[0], Indices.size()); 16846c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattner if (!TypeHasComponent(Info.AI->getAllocatedType(), Offset, 0)) 1685d01a0da090407762fe3b770d84f049d72d06467eChris Lattner MarkUnsafe(Info, GEPI); 16864cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner} 168741b33f437f70dcf63e35d08e5f4202258ef05c15Eli Friedman 1688704d1347c5009f674408fae6f78343b415891274Bob Wilson/// isHomogeneousAggregate - Check if type T is a struct or array containing 1689704d1347c5009f674408fae6f78343b415891274Bob Wilson/// elements of the same type (which is always true for arrays). If so, 1690704d1347c5009f674408fae6f78343b415891274Bob Wilson/// return true with NumElts and EltTy set to the number of elements and the 1691704d1347c5009f674408fae6f78343b415891274Bob Wilson/// element type, respectively. 1692704d1347c5009f674408fae6f78343b415891274Bob Wilsonstatic bool isHomogeneousAggregate(const Type *T, unsigned &NumElts, 1693704d1347c5009f674408fae6f78343b415891274Bob Wilson const Type *&EltTy) { 1694704d1347c5009f674408fae6f78343b415891274Bob Wilson if (const ArrayType *AT = dyn_cast<ArrayType>(T)) { 1695704d1347c5009f674408fae6f78343b415891274Bob Wilson NumElts = AT->getNumElements(); 1696f0908aeade2f41d2fed82de8d85448358b379328Bob Wilson EltTy = (NumElts == 0 ? 0 : AT->getElementType()); 1697704d1347c5009f674408fae6f78343b415891274Bob Wilson return true; 1698704d1347c5009f674408fae6f78343b415891274Bob Wilson } 1699704d1347c5009f674408fae6f78343b415891274Bob Wilson if (const StructType *ST = dyn_cast<StructType>(T)) { 1700704d1347c5009f674408fae6f78343b415891274Bob Wilson NumElts = ST->getNumContainedTypes(); 1701f0908aeade2f41d2fed82de8d85448358b379328Bob Wilson EltTy = (NumElts == 0 ? 0 : ST->getContainedType(0)); 1702704d1347c5009f674408fae6f78343b415891274Bob Wilson for (unsigned n = 1; n < NumElts; ++n) { 1703704d1347c5009f674408fae6f78343b415891274Bob Wilson if (ST->getContainedType(n) != EltTy) 1704704d1347c5009f674408fae6f78343b415891274Bob Wilson return false; 1705704d1347c5009f674408fae6f78343b415891274Bob Wilson } 1706704d1347c5009f674408fae6f78343b415891274Bob Wilson return true; 1707704d1347c5009f674408fae6f78343b415891274Bob Wilson } 1708704d1347c5009f674408fae6f78343b415891274Bob Wilson return false; 1709704d1347c5009f674408fae6f78343b415891274Bob Wilson} 1710704d1347c5009f674408fae6f78343b415891274Bob Wilson 1711704d1347c5009f674408fae6f78343b415891274Bob Wilson/// isCompatibleAggregate - Check if T1 and T2 are either the same type or are 1712704d1347c5009f674408fae6f78343b415891274Bob Wilson/// "homogeneous" aggregates with the same element type and number of elements. 1713704d1347c5009f674408fae6f78343b415891274Bob Wilsonstatic bool isCompatibleAggregate(const Type *T1, const Type *T2) { 1714704d1347c5009f674408fae6f78343b415891274Bob Wilson if (T1 == T2) 1715704d1347c5009f674408fae6f78343b415891274Bob Wilson return true; 1716704d1347c5009f674408fae6f78343b415891274Bob Wilson 1717704d1347c5009f674408fae6f78343b415891274Bob Wilson unsigned NumElts1, NumElts2; 1718704d1347c5009f674408fae6f78343b415891274Bob Wilson const Type *EltTy1, *EltTy2; 1719704d1347c5009f674408fae6f78343b415891274Bob Wilson if (isHomogeneousAggregate(T1, NumElts1, EltTy1) && 1720704d1347c5009f674408fae6f78343b415891274Bob Wilson isHomogeneousAggregate(T2, NumElts2, EltTy2) && 1721704d1347c5009f674408fae6f78343b415891274Bob Wilson NumElts1 == NumElts2 && 1722704d1347c5009f674408fae6f78343b415891274Bob Wilson EltTy1 == EltTy2) 1723704d1347c5009f674408fae6f78343b415891274Bob Wilson return true; 1724704d1347c5009f674408fae6f78343b415891274Bob Wilson 1725704d1347c5009f674408fae6f78343b415891274Bob Wilson return false; 1726704d1347c5009f674408fae6f78343b415891274Bob Wilson} 1727704d1347c5009f674408fae6f78343b415891274Bob Wilson 17284cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// isSafeMemAccess - Check if a load/store/memcpy operates on the entire AI 17294cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// alloca or has an offset and size that corresponds to a component element 17304cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// within it. The offset checked here may have been formed from a GEP with a 17314cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// pointer bitcasted to a different type. 1732145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner/// 1733145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner/// If AllowWholeAccess is true, then this allows uses of the entire alloca as a 1734145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner/// unit. If false, it only allows accesses known to be in a single element. 17356c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattnervoid SROA::isSafeMemAccess(uint64_t Offset, uint64_t MemSize, 17364cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const Type *MemOpType, bool isStore, 1737145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner AllocaInfo &Info, Instruction *TheAccess, 1738145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner bool AllowWholeAccess) { 17394cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Check if this is a load/store of the entire alloca. 1740145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner if (Offset == 0 && AllowWholeAccess && 17416c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattner MemSize == TD->getTypeAllocSize(Info.AI->getAllocatedType())) { 1742704d1347c5009f674408fae6f78343b415891274Bob Wilson // This can be safe for MemIntrinsics (where MemOpType is 0) and integer 1743704d1347c5009f674408fae6f78343b415891274Bob Wilson // loads/stores (which are essentially the same as the MemIntrinsics with 1744704d1347c5009f674408fae6f78343b415891274Bob Wilson // regard to copying padding between elements). But, if an alloca is 1745704d1347c5009f674408fae6f78343b415891274Bob Wilson // flagged as both a source and destination of such operations, we'll need 1746704d1347c5009f674408fae6f78343b415891274Bob Wilson // to check later for padding between elements. 1747704d1347c5009f674408fae6f78343b415891274Bob Wilson if (!MemOpType || MemOpType->isIntegerTy()) { 1748704d1347c5009f674408fae6f78343b415891274Bob Wilson if (isStore) 1749704d1347c5009f674408fae6f78343b415891274Bob Wilson Info.isMemCpyDst = true; 1750704d1347c5009f674408fae6f78343b415891274Bob Wilson else 1751704d1347c5009f674408fae6f78343b415891274Bob Wilson Info.isMemCpySrc = true; 17524cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return; 17534cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 1754704d1347c5009f674408fae6f78343b415891274Bob Wilson // This is also safe for references using a type that is compatible with 1755704d1347c5009f674408fae6f78343b415891274Bob Wilson // the type of the alloca, so that loads/stores can be rewritten using 1756704d1347c5009f674408fae6f78343b415891274Bob Wilson // insertvalue/extractvalue. 17576c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattner if (isCompatibleAggregate(MemOpType, Info.AI->getAllocatedType())) { 17587e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner Info.hasSubelementAccess = true; 1759704d1347c5009f674408fae6f78343b415891274Bob Wilson return; 17607e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner } 17614cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 17624cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Check if the offset/size correspond to a component within the alloca type. 17636c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattner const Type *T = Info.AI->getAllocatedType(); 17647e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner if (TypeHasComponent(T, Offset, MemSize)) { 17657e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner Info.hasSubelementAccess = true; 17664cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return; 17677e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner } 17684cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 1769d01a0da090407762fe3b770d84f049d72d06467eChris Lattner return MarkUnsafe(Info, TheAccess); 17705ffe6acd577696a41932c7b82db06a04687e07baChris Lattner} 17715ffe6acd577696a41932c7b82db06a04687e07baChris Lattner 17724cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// TypeHasComponent - Return true if T has a component type with the 17734cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// specified offset and size. If Size is zero, do not check the size. 17744cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattnerbool SROA::TypeHasComponent(const Type *T, uint64_t Offset, uint64_t Size) { 17754cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const Type *EltTy; 17764cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t EltSize; 17774cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (const StructType *ST = dyn_cast<StructType>(T)) { 17784cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const StructLayout *Layout = TD->getStructLayout(ST); 17794cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner unsigned EltIdx = Layout->getElementContainingOffset(Offset); 17804cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner EltTy = ST->getContainedType(EltIdx); 17814cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner EltSize = TD->getTypeAllocSize(EltTy); 17824cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Offset -= Layout->getElementOffset(EltIdx); 17834cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else if (const ArrayType *AT = dyn_cast<ArrayType>(T)) { 17844cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner EltTy = AT->getElementType(); 17854cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner EltSize = TD->getTypeAllocSize(EltTy); 17864cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Offset >= AT->getNumElements() * EltSize) 17874cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return false; 17884cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Offset %= EltSize; 17894cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else { 17904cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return false; 17914cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 17924cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Offset == 0 && (Size == 0 || EltSize == Size)) 17934cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return true; 17944cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Check if the component spans multiple elements. 17954cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Offset + Size > EltSize) 17964cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return false; 17974cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return TypeHasComponent(EltTy, Offset, Size); 17984cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner} 17993cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 18004cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// RewriteForScalarRepl - Alloca AI is being split into NewElts, so rewrite 18014cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// the instruction I, which references it, to use the separate elements. 18024cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// Offset indicates the position within AI that is referenced by this 18034cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// instruction. 18044cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattnervoid SROA::RewriteForScalarRepl(Instruction *I, AllocaInst *AI, uint64_t Offset, 18054cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SmallVector<AllocaInst*, 32> &NewElts) { 1806145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI!=E;) { 1807145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner Use &TheUse = UI.getUse(); 1808145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner Instruction *User = cast<Instruction>(*UI++); 18093cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 18104cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (BitCastInst *BC = dyn_cast<BitCastInst>(User)) { 18114cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner RewriteBitCast(BC, AI, Offset, NewElts); 1812145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner continue; 1813145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner } 1814145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner 1815145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(User)) { 18164cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner RewriteGEP(GEPI, AI, Offset, NewElts); 1817145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner continue; 1818145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner } 1819145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner 1820145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(User)) { 18214cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ConstantInt *Length = dyn_cast<ConstantInt>(MI->getLength()); 18224cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t MemSize = Length->getZExtValue(); 18234cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Offset == 0 && 18244cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner MemSize == TD->getTypeAllocSize(AI->getAllocatedType())) 18254cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner RewriteMemIntrinUserOfAlloca(MI, I, AI, NewElts); 18264cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Otherwise the intrinsic can only touch a single element and the 18274cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // address operand will be updated, so nothing else needs to be done. 1828145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner continue; 1829145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner } 1830145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner 1831145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(User)) { 18324cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const Type *LIType = LI->getType(); 1833192228edb1c08ca11da2df959072bcaa99eacd63Chris Lattner 1834704d1347c5009f674408fae6f78343b415891274Bob Wilson if (isCompatibleAggregate(LIType, AI->getAllocatedType())) { 18354cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Replace: 18364cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // %res = load { i32, i32 }* %alloc 18374cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // with: 18384cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // %load.0 = load i32* %alloc.0 18394cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // %insert.0 insertvalue { i32, i32 } zeroinitializer, i32 %load.0, 0 18404cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // %load.1 = load i32* %alloc.1 18414cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // %insert = insertvalue { i32, i32 } %insert.0, i32 %load.1, 1 18424cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // (Also works for arrays instead of structs) 18434cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *Insert = UndefValue::get(LIType); 1844abb25122050349ccf77f8afb198a985e7a4d95eeDevang Patel IRBuilder<> Builder(LI); 18454cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (unsigned i = 0, e = NewElts.size(); i != e; ++i) { 1846abb25122050349ccf77f8afb198a985e7a4d95eeDevang Patel Value *Load = Builder.CreateLoad(NewElts[i], "load"); 1847abb25122050349ccf77f8afb198a985e7a4d95eeDevang Patel Insert = Builder.CreateInsertValue(Insert, Load, i, "insert"); 18484cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 18494cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner LI->replaceAllUsesWith(Insert); 18504cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner DeadInsts.push_back(LI); 18514cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else if (LIType->isIntegerTy() && 18524cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner TD->getTypeAllocSize(LIType) == 18534cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner TD->getTypeAllocSize(AI->getAllocatedType())) { 18544cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If this is a load of the entire alloca to an integer, rewrite it. 18554cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner RewriteLoadUserOfWholeAlloca(LI, AI, NewElts); 18564cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 1857145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner continue; 1858145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner } 1859145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner 1860145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner if (StoreInst *SI = dyn_cast<StoreInst>(User)) { 18614cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *Val = SI->getOperand(0); 18624cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const Type *SIType = Val->getType(); 1863704d1347c5009f674408fae6f78343b415891274Bob Wilson if (isCompatibleAggregate(SIType, AI->getAllocatedType())) { 18644cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Replace: 18654cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // store { i32, i32 } %val, { i32, i32 }* %alloc 18664cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // with: 18674cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // %val.0 = extractvalue { i32, i32 } %val, 0 18684cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // store i32 %val.0, i32* %alloc.0 18694cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // %val.1 = extractvalue { i32, i32 } %val, 1 18704cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // store i32 %val.1, i32* %alloc.1 18714cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // (Also works for arrays instead of structs) 1872abb25122050349ccf77f8afb198a985e7a4d95eeDevang Patel IRBuilder<> Builder(SI); 18734cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (unsigned i = 0, e = NewElts.size(); i != e; ++i) { 1874abb25122050349ccf77f8afb198a985e7a4d95eeDevang Patel Value *Extract = Builder.CreateExtractValue(Val, i, Val->getName()); 1875abb25122050349ccf77f8afb198a985e7a4d95eeDevang Patel Builder.CreateStore(Extract, NewElts[i]); 18764cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 18774cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner DeadInsts.push_back(SI); 18784cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else if (SIType->isIntegerTy() && 18794cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner TD->getTypeAllocSize(SIType) == 18804cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner TD->getTypeAllocSize(AI->getAllocatedType())) { 18814cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If this is a store of the entire alloca from an integer, rewrite it. 18824cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner RewriteStoreUserOfWholeAlloca(SI, AI, NewElts); 188339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 1884145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner continue; 1885145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner } 1886145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner 1887145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner if (isa<SelectInst>(User) || isa<PHINode>(User)) { 1888145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner // If we have a PHI user of the alloca itself (as opposed to a GEP or 1889145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner // bitcast) we have to rewrite it. GEP and bitcast uses will be RAUW'd to 1890145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner // the new pointer. 1891145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner if (!isa<AllocaInst>(I)) continue; 1892145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner 1893145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner assert(Offset == 0 && NewElts[0] && 1894145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner "Direct alloca use should have a zero offset"); 1895145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner 1896145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner // If we have a use of the alloca, we know the derived uses will be 1897145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner // utilizing just the first element of the scalarized result. Insert a 1898145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner // bitcast of the first alloca before the user as required. 1899145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner AllocaInst *NewAI = NewElts[0]; 1900145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner BitCastInst *BCI = new BitCastInst(NewAI, AI->getType(), "", NewAI); 1901145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner NewAI->moveBefore(BCI); 1902145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner TheUse = BCI; 1903145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner continue; 190439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 19054cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 19064cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner} 19073cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 19084cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// RewriteBitCast - Update a bitcast reference to the alloca being replaced 19094cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// and recursively continue updating all of its uses. 19104cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattnervoid SROA::RewriteBitCast(BitCastInst *BC, AllocaInst *AI, uint64_t Offset, 19114cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SmallVector<AllocaInst*, 32> &NewElts) { 19124cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner RewriteForScalarRepl(BC, AI, Offset, NewElts); 19134cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (BC->getOperand(0) != AI) 19144cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return; 191539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 19164cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // The bitcast references the original alloca. Replace its uses with 19174cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // references to the first new element alloca. 19184cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Instruction *Val = NewElts[0]; 19194cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Val->getType() != BC->getDestTy()) { 19204cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Val = new BitCastInst(Val, BC->getDestTy(), "", BC); 19214cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Val->takeName(BC); 192239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 19234cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner BC->replaceAllUsesWith(Val); 19244cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner DeadInsts.push_back(BC); 192539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner} 1926372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 19274cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// FindElementAndOffset - Return the index of the element containing Offset 19284cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// within the specified type, which must be either a struct or an array. 19294cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// Sets T to the type of the element and Offset to the offset within that 19304cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// element. IdxTy is set to the type of the index result to be used in a 19314cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// GEP instruction. 19324cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattneruint64_t SROA::FindElementAndOffset(const Type *&T, uint64_t &Offset, 19334cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const Type *&IdxTy) { 19344cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t Idx = 0; 19354cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (const StructType *ST = dyn_cast<StructType>(T)) { 19364cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const StructLayout *Layout = TD->getStructLayout(ST); 19374cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Idx = Layout->getElementContainingOffset(Offset); 19384cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner T = ST->getContainedType(Idx); 19394cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Offset -= Layout->getElementOffset(Idx); 19404cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner IdxTy = Type::getInt32Ty(T->getContext()); 19414cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return Idx; 1942f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner } 19434cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const ArrayType *AT = cast<ArrayType>(T); 19444cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner T = AT->getElementType(); 19454cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t EltSize = TD->getTypeAllocSize(T); 19464cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Idx = Offset / EltSize; 19474cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Offset -= Idx * EltSize; 19484cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner IdxTy = Type::getInt64Ty(T->getContext()); 19494cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return Idx; 19505e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner} 1951a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 19524cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// RewriteGEP - Check if this GEP instruction moves the pointer across 19534cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// elements of the alloca that are being split apart, and if so, rewrite 19544cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// the GEP to be relative to the new element. 19554cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattnervoid SROA::RewriteGEP(GetElementPtrInst *GEPI, AllocaInst *AI, uint64_t Offset, 19564cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SmallVector<AllocaInst*, 32> &NewElts) { 19574cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t OldOffset = Offset; 19584cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SmallVector<Value*, 8> Indices(GEPI->op_begin() + 1, GEPI->op_end()); 19594cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Offset += TD->getIndexedOffset(GEPI->getPointerOperandType(), 19604cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner &Indices[0], Indices.size()); 19614cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 19624cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner RewriteForScalarRepl(GEPI, AI, Offset, NewElts); 19634cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 19644cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const Type *T = AI->getAllocatedType(); 19654cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const Type *IdxTy; 19664cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t OldIdx = FindElementAndOffset(T, OldOffset, IdxTy); 19674cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (GEPI->getOperand(0) == AI) 19684cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner OldIdx = ~0ULL; // Force the GEP to be rewritten. 19694cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 19704cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner T = AI->getAllocatedType(); 19714cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t EltOffset = Offset; 19724cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t Idx = FindElementAndOffset(T, EltOffset, IdxTy); 19734cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 19744cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If this GEP does not move the pointer across elements of the alloca 19754cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // being split, then it does not needs to be rewritten. 19764cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Idx == OldIdx) 1977c4472072641f702dbd99ae12b7da089e75c44a99Chris Lattner return; 1978c4472072641f702dbd99ae12b7da089e75c44a99Chris Lattner 19794cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const Type *i32Ty = Type::getInt32Ty(AI->getContext()); 19804cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SmallVector<Value*, 8> NewArgs; 19814cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner NewArgs.push_back(Constant::getNullValue(i32Ty)); 19824cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner while (EltOffset != 0) { 19834cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t EltIdx = FindElementAndOffset(T, EltOffset, IdxTy); 19844cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner NewArgs.push_back(ConstantInt::get(IdxTy, EltIdx)); 19852e0d5f84325303fa95997cd66485811bd0a6ef70Chris Lattner } 19864cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Instruction *Val = NewElts[Idx]; 19874cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (NewArgs.size() > 1) { 19884cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Val = GetElementPtrInst::CreateInBounds(Val, NewArgs.begin(), 19894cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner NewArgs.end(), "", GEPI); 19904cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Val->takeName(GEPI); 19914cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 19924cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Val->getType() != GEPI->getType()) 19934cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Val = new BitCastInst(Val, GEPI->getType(), Val->getName(), GEPI); 19944cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner GEPI->replaceAllUsesWith(Val); 19954cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner DeadInsts.push_back(GEPI); 1996a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner} 1997a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 19984cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// RewriteMemIntrinUserOfAlloca - MI is a memcpy/memset/memmove from or to AI. 19994cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// Rewrite it to copy or set the elements of the scalarized memory. 20004cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattnervoid SROA::RewriteMemIntrinUserOfAlloca(MemIntrinsic *MI, Instruction *Inst, 20014cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner AllocaInst *AI, 20024cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SmallVector<AllocaInst*, 32> &NewElts) { 20034cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If this is a memcpy/memmove, construct the other pointer as the 20044cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // appropriate type. The "Other" pointer is the pointer that goes to memory 20054cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // that doesn't have anything to do with the alloca that we are promoting. For 20064cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // memset, this Value* stays null. 20074cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *OtherPtr = 0; 20084cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner unsigned MemAlignment = MI->getAlignment(); 20094cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI)) { // memmove/memcopy 20104cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Inst == MTI->getRawDest()) 20114cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner OtherPtr = MTI->getRawSource(); 20124cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner else { 20134cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner assert(Inst == MTI->getRawSource()); 20144cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner OtherPtr = MTI->getRawDest(); 2015a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 20164cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 20173ce5e887aef457701da95f1c6ccbd58ec3d32fe4Chris Lattner 20184cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If there is an other pointer, we want to convert it to the same pointer 20194cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // type as AI has, so we can GEP through it safely. 20204cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (OtherPtr) { 20210238f8c430050d23ef861169bb4c4f930af0ef97Chris Lattner unsigned AddrSpace = 20220238f8c430050d23ef861169bb4c4f930af0ef97Chris Lattner cast<PointerType>(OtherPtr->getType())->getAddressSpace(); 20234cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 20244cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Remove bitcasts and all-zero GEPs from OtherPtr. This is an 20254cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // optimization, but it's also required to detect the corner case where 20264cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // both pointer operands are referencing the same memory, and where 20274cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // OtherPtr may be a bitcast or GEP that currently being rewritten. (This 20284cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // function is only called for mem intrinsics that access the whole 20294cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // aggregate, so non-zero GEPs are not an issue here.) 20300238f8c430050d23ef861169bb4c4f930af0ef97Chris Lattner OtherPtr = OtherPtr->stripPointerCasts(); 20316974302e3ff20746268721959efed807c7711bfcBob Wilson 20324cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Copying the alloca to itself is a no-op: just delete it. 20334cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (OtherPtr == AI || OtherPtr == NewElts[0]) { 20344cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // This code will run twice for a no-op memcpy -- once for each operand. 20354cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Put only one reference to MI on the DeadInsts list. 20364cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (SmallVector<Value*, 32>::const_iterator I = DeadInsts.begin(), 20374cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner E = DeadInsts.end(); I != E; ++I) 20384cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (*I == MI) return; 20394cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner DeadInsts.push_back(MI); 20404cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return; 2041c570487d45f7426dc5f75c0309122d6f9330ecf7Chris Lattner } 20426974302e3ff20746268721959efed807c7711bfcBob Wilson 20434cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If the pointer is not the right type, insert a bitcast to the right 20444cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // type. 20450238f8c430050d23ef861169bb4c4f930af0ef97Chris Lattner const Type *NewTy = 20460238f8c430050d23ef861169bb4c4f930af0ef97Chris Lattner PointerType::get(AI->getType()->getElementType(), AddrSpace); 20476974302e3ff20746268721959efed807c7711bfcBob Wilson 20480238f8c430050d23ef861169bb4c4f930af0ef97Chris Lattner if (OtherPtr->getType() != NewTy) 20490238f8c430050d23ef861169bb4c4f930af0ef97Chris Lattner OtherPtr = new BitCastInst(OtherPtr, NewTy, OtherPtr->getName(), MI); 2050a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 20516974302e3ff20746268721959efed807c7711bfcBob Wilson 20524cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Process each element of the aggregate. 20534cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner bool SROADest = MI->getRawDest() == Inst; 20546974302e3ff20746268721959efed807c7711bfcBob Wilson 20554cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Constant *Zero = Constant::getNullValue(Type::getInt32Ty(MI->getContext())); 20564b3dfbd220835cbba519162712c9cb6afaa44059Duncan Sands 20574cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (unsigned i = 0, e = NewElts.size(); i != e; ++i) { 20584cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If this is a memcpy/memmove, emit a GEP of the other element address. 20594cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *OtherElt = 0; 20604cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner unsigned OtherEltAlign = MemAlignment; 20616974302e3ff20746268721959efed807c7711bfcBob Wilson 20624cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (OtherPtr) { 20634cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *Idx[2] = { Zero, 20644cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ConstantInt::get(Type::getInt32Ty(MI->getContext()), i) }; 20654cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner OtherElt = GetElementPtrInst::CreateInBounds(OtherPtr, Idx, Idx + 2, 20664cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner OtherPtr->getName()+"."+Twine(i), 20674cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner MI); 20684cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t EltOffset; 20694cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const PointerType *OtherPtrTy = cast<PointerType>(OtherPtr->getType()); 2070d55c1c16598eba6111fb3a5b6e5dbc6469a562f7Chris Lattner const Type *OtherTy = OtherPtrTy->getElementType(); 2071d55c1c16598eba6111fb3a5b6e5dbc6469a562f7Chris Lattner if (const StructType *ST = dyn_cast<StructType>(OtherTy)) { 20724cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner EltOffset = TD->getStructLayout(ST)->getElementOffset(i); 20734cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else { 2074d55c1c16598eba6111fb3a5b6e5dbc6469a562f7Chris Lattner const Type *EltTy = cast<SequentialType>(OtherTy)->getElementType(); 20754cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner EltOffset = TD->getTypeAllocSize(EltTy)*i; 20764cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 20776974302e3ff20746268721959efed807c7711bfcBob Wilson 20784cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // The alignment of the other pointer is the guaranteed alignment of the 20794cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // element, which is affected by both the known alignment of the whole 20804cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // mem intrinsic and the alignment of the element. If the alignment of 20814cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // the memcpy (f.e.) is 32 but the element is at a 4-byte offset, then the 20824cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // known alignment is just 4 bytes. 20834cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner OtherEltAlign = (unsigned)MinAlign(OtherEltAlign, EltOffset); 20849bc67da0a9982f2f7597d1d46cf18f079e4f8f98Chris Lattner } 20856974302e3ff20746268721959efed807c7711bfcBob Wilson 20864cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *EltPtr = NewElts[i]; 20874cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const Type *EltTy = cast<PointerType>(EltPtr->getType())->getElementType(); 20886974302e3ff20746268721959efed807c7711bfcBob Wilson 20894cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If we got down to a scalar, insert a load or store as appropriate. 20904cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (EltTy->isSingleValueType()) { 20914cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (isa<MemTransferInst>(MI)) { 20924cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (SROADest) { 20934cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // From Other to Alloca. 20944cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *Elt = new LoadInst(OtherElt, "tmp", false, OtherEltAlign, MI); 20954cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner new StoreInst(Elt, EltPtr, MI); 20964cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else { 20974cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // From Alloca to Other. 20984cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *Elt = new LoadInst(EltPtr, "tmp", MI); 20994cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner new StoreInst(Elt, OtherElt, false, OtherEltAlign, MI); 21004cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 21014cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner continue; 210233e24adc3bc3d046aa05cf903fb74da1610b57cbChris Lattner } 21034cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner assert(isa<MemSetInst>(MI)); 21046974302e3ff20746268721959efed807c7711bfcBob Wilson 21054cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If the stored element is zero (common case), just store a null 21064cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // constant. 21074cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Constant *StoreVal; 21086f14c8c7c1ec97797a04631abad6885bfaabcc6dGabor Greif if (ConstantInt *CI = dyn_cast<ConstantInt>(MI->getArgOperand(1))) { 21094cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (CI->isZero()) { 21104cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner StoreVal = Constant::getNullValue(EltTy); // 0.0, null, 0, <0,0> 21114cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else { 21124cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If EltTy is a vector type, get the element type. 21134cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const Type *ValTy = EltTy->getScalarType(); 2114c570487d45f7426dc5f75c0309122d6f9330ecf7Chris Lattner 21154cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Construct an integer with the right value. 21164cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner unsigned EltSize = TD->getTypeSizeInBits(ValTy); 21174cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner APInt OneVal(EltSize, CI->getZExtValue()); 21184cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner APInt TotalVal(OneVal); 21194cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Set each byte. 21204cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (unsigned i = 0; 8*i < EltSize; ++i) { 21214cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner TotalVal = TotalVal.shl(8); 21224cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner TotalVal |= OneVal; 21234cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 21246974302e3ff20746268721959efed807c7711bfcBob Wilson 21254cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Convert the integer value to the appropriate type. 2126d55c1c16598eba6111fb3a5b6e5dbc6469a562f7Chris Lattner StoreVal = ConstantInt::get(CI->getContext(), TotalVal); 21274cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (ValTy->isPointerTy()) 21284cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner StoreVal = ConstantExpr::getIntToPtr(StoreVal, ValTy); 21294cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner else if (ValTy->isFloatingPointTy()) 21304cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner StoreVal = ConstantExpr::getBitCast(StoreVal, ValTy); 21314cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner assert(StoreVal->getType() == ValTy && "Type mismatch!"); 21326974302e3ff20746268721959efed807c7711bfcBob Wilson 21334cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If the requested value was a vector constant, create it. 21344cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (EltTy != ValTy) { 21354cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner unsigned NumElts = cast<VectorType>(ValTy)->getNumElements(); 21364cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SmallVector<Constant*, 16> Elts(NumElts, StoreVal); 21372ca5c8644e6c35b3a7910a576ed89cddb7b82c3bChris Lattner StoreVal = ConstantVector::get(Elts); 21384cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 21394cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 21404cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner new StoreInst(StoreVal, EltPtr, MI); 21414cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner continue; 21424cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 21434cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Otherwise, if we're storing a byte variable, use a memset call for 21444cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // this element. 21454cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 21466974302e3ff20746268721959efed807c7711bfcBob Wilson 21474cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner unsigned EltSize = TD->getTypeAllocSize(EltTy); 21486974302e3ff20746268721959efed807c7711bfcBob Wilson 214961db1f56d0b717d67557bbb2a9d83af1449458cbChris Lattner IRBuilder<> Builder(MI); 21506974302e3ff20746268721959efed807c7711bfcBob Wilson 21514cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Finally, insert the meminst for this element. 215261db1f56d0b717d67557bbb2a9d83af1449458cbChris Lattner if (isa<MemSetInst>(MI)) { 215361db1f56d0b717d67557bbb2a9d83af1449458cbChris Lattner Builder.CreateMemSet(EltPtr, MI->getArgOperand(1), EltSize, 215461db1f56d0b717d67557bbb2a9d83af1449458cbChris Lattner MI->isVolatile()); 21554cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else { 215661db1f56d0b717d67557bbb2a9d83af1449458cbChris Lattner assert(isa<MemTransferInst>(MI)); 215761db1f56d0b717d67557bbb2a9d83af1449458cbChris Lattner Value *Dst = SROADest ? EltPtr : OtherElt; // Dest ptr 215861db1f56d0b717d67557bbb2a9d83af1449458cbChris Lattner Value *Src = SROADest ? OtherElt : EltPtr; // Src ptr 21596974302e3ff20746268721959efed807c7711bfcBob Wilson 216061db1f56d0b717d67557bbb2a9d83af1449458cbChris Lattner if (isa<MemCpyInst>(MI)) 216161db1f56d0b717d67557bbb2a9d83af1449458cbChris Lattner Builder.CreateMemCpy(Dst, Src, EltSize, OtherEltAlign,MI->isVolatile()); 216261db1f56d0b717d67557bbb2a9d83af1449458cbChris Lattner else 216361db1f56d0b717d67557bbb2a9d83af1449458cbChris Lattner Builder.CreateMemMove(Dst, Src, EltSize,OtherEltAlign,MI->isVolatile()); 21644cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 2165a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 21664cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner DeadInsts.push_back(MI); 2167a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner} 216879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 21694cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// RewriteStoreUserOfWholeAlloca - We found a store of an integer that 21704cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// overwrites the entire allocation. Extract out the pieces of the stored 21714cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// integer and store them individually. 21724cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattnervoid SROA::RewriteStoreUserOfWholeAlloca(StoreInst *SI, AllocaInst *AI, 21734cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SmallVector<AllocaInst*, 32> &NewElts){ 21744cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Extract each element out of the integer according to its structure offset 21754cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // and store the element value to the individual alloca. 21764cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *SrcVal = SI->getOperand(0); 21774cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const Type *AllocaEltTy = AI->getAllocatedType(); 21784cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t AllocaSizeBits = TD->getTypeAllocSizeInBits(AllocaEltTy); 21796974302e3ff20746268721959efed807c7711bfcBob Wilson 218070728532799d751b8e0e97719dcb3344a2fc97deChris Lattner IRBuilder<> Builder(SI); 218170728532799d751b8e0e97719dcb3344a2fc97deChris Lattner 21824cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Handle tail padding by extending the operand 21834cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (TD->getTypeSizeInBits(SrcVal->getType()) != AllocaSizeBits) 218470728532799d751b8e0e97719dcb3344a2fc97deChris Lattner SrcVal = Builder.CreateZExt(SrcVal, 218570728532799d751b8e0e97719dcb3344a2fc97deChris Lattner IntegerType::get(SI->getContext(), AllocaSizeBits)); 21864b3dfbd220835cbba519162712c9cb6afaa44059Duncan Sands 21874cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner DEBUG(dbgs() << "PROMOTING STORE TO WHOLE ALLOCA: " << *AI << '\n' << *SI 21884cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner << '\n'); 21894b3dfbd220835cbba519162712c9cb6afaa44059Duncan Sands 21904cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // There are two forms here: AI could be an array or struct. Both cases 21914cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // have different ways to compute the element offset. 21924cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (const StructType *EltSTy = dyn_cast<StructType>(AllocaEltTy)) { 21934cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const StructLayout *Layout = TD->getStructLayout(EltSTy); 21946974302e3ff20746268721959efed807c7711bfcBob Wilson 21954cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (unsigned i = 0, e = NewElts.size(); i != e; ++i) { 21964cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Get the number of bits to shift SrcVal to get the value. 21974cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const Type *FieldTy = EltSTy->getElementType(i); 21984cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t Shift = Layout->getElementOffsetInBits(i); 21996974302e3ff20746268721959efed807c7711bfcBob Wilson 22004cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (TD->isBigEndian()) 22014cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Shift = AllocaSizeBits-Shift-TD->getTypeAllocSizeInBits(FieldTy); 22026974302e3ff20746268721959efed807c7711bfcBob Wilson 22034cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *EltVal = SrcVal; 22044cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Shift) { 22054cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *ShiftVal = ConstantInt::get(EltVal->getType(), Shift); 220670728532799d751b8e0e97719dcb3344a2fc97deChris Lattner EltVal = Builder.CreateLShr(EltVal, ShiftVal, "sroa.store.elt"); 22074cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 22086974302e3ff20746268721959efed807c7711bfcBob Wilson 22094cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Truncate down to an integer of the right size. 22104cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t FieldSizeBits = TD->getTypeSizeInBits(FieldTy); 22116974302e3ff20746268721959efed807c7711bfcBob Wilson 22124cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Ignore zero sized fields like {}, they obviously contain no data. 22134cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (FieldSizeBits == 0) continue; 22146974302e3ff20746268721959efed807c7711bfcBob Wilson 22154cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (FieldSizeBits != AllocaSizeBits) 221670728532799d751b8e0e97719dcb3344a2fc97deChris Lattner EltVal = Builder.CreateTrunc(EltVal, 221770728532799d751b8e0e97719dcb3344a2fc97deChris Lattner IntegerType::get(SI->getContext(), FieldSizeBits)); 22184cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *DestField = NewElts[i]; 22194cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (EltVal->getType() == FieldTy) { 22204cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Storing to an integer field of this size, just do it. 22214cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else if (FieldTy->isFloatingPointTy() || FieldTy->isVectorTy()) { 22224cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Bitcast to the right element type (for fp/vector values). 222370728532799d751b8e0e97719dcb3344a2fc97deChris Lattner EltVal = Builder.CreateBitCast(EltVal, FieldTy); 22244cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else { 22254cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Otherwise, bitcast the dest pointer (for aggregates). 222670728532799d751b8e0e97719dcb3344a2fc97deChris Lattner DestField = Builder.CreateBitCast(DestField, 222770728532799d751b8e0e97719dcb3344a2fc97deChris Lattner PointerType::getUnqual(EltVal->getType())); 22284cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 22294cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner new StoreInst(EltVal, DestField, SI); 22304cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 22316974302e3ff20746268721959efed807c7711bfcBob Wilson 22329d34c4d678cfc836a59a114b7b2cf91e9dd5eac4Chris Lattner } else { 22334cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const ArrayType *ATy = cast<ArrayType>(AllocaEltTy); 22344cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const Type *ArrayEltTy = ATy->getElementType(); 22354cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t ElementOffset = TD->getTypeAllocSizeInBits(ArrayEltTy); 22364cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t ElementSizeBits = TD->getTypeSizeInBits(ArrayEltTy); 22374b3dfbd220835cbba519162712c9cb6afaa44059Duncan Sands 22384cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t Shift; 22396974302e3ff20746268721959efed807c7711bfcBob Wilson 22404cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (TD->isBigEndian()) 22414cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Shift = AllocaSizeBits-ElementOffset; 22426974302e3ff20746268721959efed807c7711bfcBob Wilson else 22434cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Shift = 0; 22446974302e3ff20746268721959efed807c7711bfcBob Wilson 22454cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (unsigned i = 0, e = NewElts.size(); i != e; ++i) { 22464cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Ignore zero sized fields like {}, they obviously contain no data. 22474cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (ElementSizeBits == 0) continue; 22486974302e3ff20746268721959efed807c7711bfcBob Wilson 22494cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *EltVal = SrcVal; 22504cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Shift) { 22514cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *ShiftVal = ConstantInt::get(EltVal->getType(), Shift); 225270728532799d751b8e0e97719dcb3344a2fc97deChris Lattner EltVal = Builder.CreateLShr(EltVal, ShiftVal, "sroa.store.elt"); 22534cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 22546974302e3ff20746268721959efed807c7711bfcBob Wilson 22554cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Truncate down to an integer of the right size. 22564cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (ElementSizeBits != AllocaSizeBits) 225770728532799d751b8e0e97719dcb3344a2fc97deChris Lattner EltVal = Builder.CreateTrunc(EltVal, 225870728532799d751b8e0e97719dcb3344a2fc97deChris Lattner IntegerType::get(SI->getContext(), 225970728532799d751b8e0e97719dcb3344a2fc97deChris Lattner ElementSizeBits)); 22604cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *DestField = NewElts[i]; 22614cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (EltVal->getType() == ArrayEltTy) { 22624cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Storing to an integer field of this size, just do it. 22634cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else if (ArrayEltTy->isFloatingPointTy() || 22644cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ArrayEltTy->isVectorTy()) { 22654cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Bitcast to the right element type (for fp/vector values). 226670728532799d751b8e0e97719dcb3344a2fc97deChris Lattner EltVal = Builder.CreateBitCast(EltVal, ArrayEltTy); 22674cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else { 22684cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Otherwise, bitcast the dest pointer (for aggregates). 226970728532799d751b8e0e97719dcb3344a2fc97deChris Lattner DestField = Builder.CreateBitCast(DestField, 227070728532799d751b8e0e97719dcb3344a2fc97deChris Lattner PointerType::getUnqual(EltVal->getType())); 22714cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 22724cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner new StoreInst(EltVal, DestField, SI); 22736974302e3ff20746268721959efed807c7711bfcBob Wilson 22744cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (TD->isBigEndian()) 22754cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Shift -= ElementOffset; 22766974302e3ff20746268721959efed807c7711bfcBob Wilson else 22774cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Shift += ElementOffset; 22784cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 2279800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 22806974302e3ff20746268721959efed807c7711bfcBob Wilson 22814cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner DeadInsts.push_back(SI); 2282800de31776356910eb877e71df9f32b0a6215324Chris Lattner} 2283800de31776356910eb877e71df9f32b0a6215324Chris Lattner 22844cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// RewriteLoadUserOfWholeAlloca - We found a load of the entire allocation to 22854cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// an integer. Load the individual pieces to form the aggregate value. 22864cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattnervoid SROA::RewriteLoadUserOfWholeAlloca(LoadInst *LI, AllocaInst *AI, 22874cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SmallVector<AllocaInst*, 32> &NewElts) { 22884cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Extract each element out of the NewElts according to its structure offset 22894cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // and form the result value. 22904cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const Type *AllocaEltTy = AI->getAllocatedType(); 22914cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t AllocaSizeBits = TD->getTypeAllocSizeInBits(AllocaEltTy); 22926974302e3ff20746268721959efed807c7711bfcBob Wilson 22934cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner DEBUG(dbgs() << "PROMOTING LOAD OF WHOLE ALLOCA: " << *AI << '\n' << *LI 22944cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner << '\n'); 22956974302e3ff20746268721959efed807c7711bfcBob Wilson 22964cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // There are two forms here: AI could be an array or struct. Both cases 22974cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // have different ways to compute the element offset. 22984cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const StructLayout *Layout = 0; 22994cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t ArrayEltBitOffset = 0; 23004cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (const StructType *EltSTy = dyn_cast<StructType>(AllocaEltTy)) { 23014cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Layout = TD->getStructLayout(EltSTy); 23024cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } else { 23034cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const Type *ArrayEltTy = cast<ArrayType>(AllocaEltTy)->getElementType(); 23044cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ArrayEltBitOffset = TD->getTypeAllocSizeInBits(ArrayEltTy); 23056974302e3ff20746268721959efed807c7711bfcBob Wilson } 23066974302e3ff20746268721959efed807c7711bfcBob Wilson 23076974302e3ff20746268721959efed807c7711bfcBob Wilson Value *ResultVal = 23084cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Constant::getNullValue(IntegerType::get(LI->getContext(), AllocaSizeBits)); 23096974302e3ff20746268721959efed807c7711bfcBob Wilson 23104cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner for (unsigned i = 0, e = NewElts.size(); i != e; ++i) { 23114cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Load the value from the alloca. If the NewElt is an aggregate, cast 23124cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // the pointer to an integer of the same size before doing the load. 23134cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *SrcField = NewElts[i]; 23144cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner const Type *FieldTy = 23154cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner cast<PointerType>(SrcField->getType())->getElementType(); 23164cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t FieldSizeBits = TD->getTypeSizeInBits(FieldTy); 23176974302e3ff20746268721959efed807c7711bfcBob Wilson 23184cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Ignore zero sized fields like {}, they obviously contain no data. 23194cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (FieldSizeBits == 0) continue; 23206974302e3ff20746268721959efed807c7711bfcBob Wilson 23216974302e3ff20746268721959efed807c7711bfcBob Wilson const IntegerType *FieldIntTy = IntegerType::get(LI->getContext(), 23224cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner FieldSizeBits); 23234cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (!FieldTy->isIntegerTy() && !FieldTy->isFloatingPointTy() && 23244cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner !FieldTy->isVectorTy()) 23254cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SrcField = new BitCastInst(SrcField, 23264cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner PointerType::getUnqual(FieldIntTy), 23274cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner "", LI); 23284cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SrcField = new LoadInst(SrcField, "sroa.load.elt", LI); 232929e641761e81bd000bdc4ccfae479c6dda18e402Chris Lattner 23304cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // If SrcField is a fp or vector of the right size but that isn't an 23314cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // integer type, bitcast to an integer so we can shift it. 23324cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (SrcField->getType() != FieldIntTy) 23334cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SrcField = new BitCastInst(SrcField, FieldIntTy, "", LI); 233429e641761e81bd000bdc4ccfae479c6dda18e402Chris Lattner 23354cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Zero extend the field to be the same size as the final alloca so that 23364cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // we can shift and insert it. 23374cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (SrcField->getType() != ResultVal->getType()) 23384cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SrcField = new ZExtInst(SrcField, ResultVal->getType(), "", LI); 23396974302e3ff20746268721959efed807c7711bfcBob Wilson 23404cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Determine the number of bits to shift SrcField. 23414cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner uint64_t Shift; 23424cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Layout) // Struct case. 23434cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Shift = Layout->getElementOffsetInBits(i); 23444cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner else // Array case. 23454cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Shift = i*ArrayEltBitOffset; 23466974302e3ff20746268721959efed807c7711bfcBob Wilson 23474cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (TD->isBigEndian()) 23484cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Shift = AllocaSizeBits-Shift-FieldIntTy->getBitWidth(); 23496974302e3ff20746268721959efed807c7711bfcBob Wilson 23504cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Shift) { 23514cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner Value *ShiftVal = ConstantInt::get(SrcField->getType(), Shift); 23524cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner SrcField = BinaryOperator::CreateShl(SrcField, ShiftVal, "", LI); 23539b872db775797dea4b391a9347cfbd2ca9c558e2Chris Lattner } 23544cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 23551495247f517c0ac3aeeb9e6c7c0205dd7849d332Chris Lattner // Don't create an 'or x, 0' on the first iteration. 23561495247f517c0ac3aeeb9e6c7c0205dd7849d332Chris Lattner if (!isa<Constant>(ResultVal) || 23571495247f517c0ac3aeeb9e6c7c0205dd7849d332Chris Lattner !cast<Constant>(ResultVal)->isNullValue()) 23581495247f517c0ac3aeeb9e6c7c0205dd7849d332Chris Lattner ResultVal = BinaryOperator::CreateOr(SrcField, ResultVal, "", LI); 23591495247f517c0ac3aeeb9e6c7c0205dd7849d332Chris Lattner else 23601495247f517c0ac3aeeb9e6c7c0205dd7849d332Chris Lattner ResultVal = SrcField; 23619b872db775797dea4b391a9347cfbd2ca9c558e2Chris Lattner } 23624b3dfbd220835cbba519162712c9cb6afaa44059Duncan Sands 23634cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Handle tail padding by truncating the result 23644cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (TD->getTypeSizeInBits(LI->getType()) != AllocaSizeBits) 23654cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner ResultVal = new TruncInst(ResultVal, LI->getType(), "", LI); 23664b3dfbd220835cbba519162712c9cb6afaa44059Duncan Sands 23674cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner LI->replaceAllUsesWith(ResultVal); 23684cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner DeadInsts.push_back(LI); 23694cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner} 23704cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 23714cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// HasPadding - Return true if the specified type has any structure or 2372694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson/// alignment padding in between the elements that would be split apart 2373694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson/// by SROA; return false otherwise. 23744cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattnerstatic bool HasPadding(const Type *Ty, const TargetData &TD) { 2375694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) { 2376694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson Ty = ATy->getElementType(); 2377694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson return TD.getTypeSizeInBits(Ty) != TD.getTypeAllocSizeInBits(Ty); 2378694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson } 23794cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 2380694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson // SROA currently handles only Arrays and Structs. 2381694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson const StructType *STy = cast<StructType>(Ty); 2382694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson const StructLayout *SL = TD.getStructLayout(STy); 2383694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson unsigned PrevFieldBitOffset = 0; 2384694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { 2385694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson unsigned FieldBitOffset = SL->getElementOffsetInBits(i); 2386694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson 2387694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson // Check to see if there is any padding between this element and the 2388694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson // previous one. 2389694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson if (i) { 2390694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson unsigned PrevFieldEnd = 23914cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner PrevFieldBitOffset+TD.getTypeSizeInBits(STy->getElementType(i-1)); 2392694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson if (PrevFieldEnd < FieldBitOffset) 23934cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return true; 23944cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner } 2395694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson PrevFieldBitOffset = FieldBitOffset; 23962e0d5f84325303fa95997cd66485811bd0a6ef70Chris Lattner } 2397694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson // Check for tail padding. 2398694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson if (unsigned EltCount = STy->getNumElements()) { 2399694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson unsigned PrevFieldEnd = PrevFieldBitOffset + 2400694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson TD.getTypeSizeInBits(STy->getElementType(EltCount-1)); 2401694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson if (PrevFieldEnd < SL->getSizeInBits()) 2402694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson return true; 2403694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson } 2404694a10e7d8410f24639971224ce0e282c8cd04cbBob Wilson return false; 24054cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner} 24064b3dfbd220835cbba519162712c9cb6afaa44059Duncan Sands 24074cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// isSafeStructAllocaToScalarRepl - Check to see if the specified allocation of 24084cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// an aggregate can be broken down into elements. Return 0 if not, 3 if safe, 24094cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner/// or 1 if safe after canonicalization has been performed. 24104cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattnerbool SROA::isSafeAllocaToScalarRepl(AllocaInst *AI) { 24114cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Loop over the use list of the alloca. We can only transform it if all of 24124cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // the users are safe to transform. 24136c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattner AllocaInfo Info(AI); 24146974302e3ff20746268721959efed807c7711bfcBob Wilson 24156c95d24927b11fb76bc3e76ebe6a8198d74fc178Chris Lattner isSafeForScalarRepl(AI, 0, Info); 24164cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Info.isUnsafe) { 24174cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner DEBUG(dbgs() << "Cannot transform: " << *AI << '\n'); 24184cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return false; 2419800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 24206974302e3ff20746268721959efed807c7711bfcBob Wilson 24214cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // Okay, we know all the users are promotable. If the aggregate is a memcpy 24224cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // source and destination, we have to be careful. In particular, the memcpy 24234cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // could be moving around elements that live in structure padding of the LLVM 24244cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // types, but may actually be used. In these cases, we refuse to promote the 24254cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner // struct. 24264cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner if (Info.isMemCpySrc && Info.isMemCpyDst && 24274cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner HasPadding(AI->getAllocatedType(), *TD)) 24284cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return false; 24294cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner 2430396a0567cf959d86a8a1ad185e54d84f5dacbacfChris Lattner // If the alloca never has an access to just *part* of it, but is accessed 2431396a0567cf959d86a8a1ad185e54d84f5dacbacfChris Lattner // via loads and stores, then we should use ConvertToScalarInfo to promote 24327e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner // the alloca instead of promoting each piece at a time and inserting fission 24337e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner // and fusion code. 24347e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner if (!Info.hasSubelementAccess && Info.hasALoadOrStore) { 24357e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner // If the struct/array just has one element, use basic SRoA. 24367e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner if (const StructType *ST = dyn_cast<StructType>(AI->getAllocatedType())) { 24377e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner if (ST->getNumElements() > 1) return false; 24387e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner } else { 24397e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner if (cast<ArrayType>(AI->getAllocatedType())->getNumElements() > 1) 24407e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner return false; 24417e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner } 24427e9b427c879ae32b72fd24aeaf011e87e5692fd7Chris Lattner } 2443145c532e68acdf70d40bab5bc2034f692848b8dcChris Lattner 24444cc576bc5ea27951f3bb15ccefbe483293bf8eafChris Lattner return true; 2445800de31776356910eb877e71df9f32b0a6215324Chris Lattner} 2446800de31776356910eb877e71df9f32b0a6215324Chris Lattner 2447800de31776356910eb877e71df9f32b0a6215324Chris Lattner 244879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 244979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// PointsToConstantGlobal - Return true if V (possibly indirectly) points to 245079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// some part of a constant global variable. This intentionally only accepts 245179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// constant expressions because we don't can't rewrite arbitrary instructions. 245279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattnerstatic bool PointsToConstantGlobal(Value *V) { 245379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) 245479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return GV->isConstant(); 245579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) 24566974302e3ff20746268721959efed807c7711bfcBob Wilson if (CE->getOpcode() == Instruction::BitCast || 245779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner CE->getOpcode() == Instruction::GetElementPtr) 245879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return PointsToConstantGlobal(CE->getOperand(0)); 245979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return false; 246079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner} 246179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 246279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// isOnlyCopiedFromConstantGlobal - Recursively walk the uses of a (derived) 246379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// pointer to an alloca. Ignore any reads of the pointer, return false if we 246479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// see any stores or other unknown uses. If we see pointer arithmetic, keep 246579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// track of whether it moves the pointer (with isOffset) but otherwise traverse 246679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// the uses. If we see a memcpy/memmove that targets an unoffseted pointer to 2467081f80078dccf02c1f9c61378ff88bbf1b4afb5eNick Lewycky/// the alloca, and if the source pointer is a pointer to a constant global, we 246879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// can optimize this. 246931d80103d56c026403d7fb6c50833664ff63ddcbChris Lattnerstatic bool isOnlyCopiedFromConstantGlobal(Value *V, MemTransferInst *&TheCopy, 247079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner bool isOffset) { 247179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI!=E; ++UI) { 24728a8a4350db3e66a517dc179ba38439c66bb726a8Gabor Greif User *U = cast<Instruction>(*UI); 24738a8a4350db3e66a517dc179ba38439c66bb726a8Gabor Greif 24742e61849f45144f2f05d57b00947df7e101610694Chris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(U)) { 24756e733d34ca487ab7ff8a6def018a933620393869Chris Lattner // Ignore non-volatile loads, they are always ok. 24762e61849f45144f2f05d57b00947df7e101610694Chris Lattner if (LI->isVolatile()) return false; 24772e61849f45144f2f05d57b00947df7e101610694Chris Lattner continue; 24782e61849f45144f2f05d57b00947df7e101610694Chris Lattner } 24796974302e3ff20746268721959efed807c7711bfcBob Wilson 24808a8a4350db3e66a517dc179ba38439c66bb726a8Gabor Greif if (BitCastInst *BCI = dyn_cast<BitCastInst>(U)) { 248179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If uses of the bitcast are ok, we are ok. 248279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (!isOnlyCopiedFromConstantGlobal(BCI, TheCopy, isOffset)) 248379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return false; 248479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner continue; 248579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner } 24868a8a4350db3e66a517dc179ba38439c66bb726a8Gabor Greif if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(U)) { 248779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If the GEP has all zero indices, it doesn't offset the pointer. If it 248879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // doesn't, it does. 248979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (!isOnlyCopiedFromConstantGlobal(GEP, TheCopy, 249079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner isOffset || !GEP->hasAllZeroIndices())) 249179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return false; 249279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner continue; 249379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner } 24946974302e3ff20746268721959efed807c7711bfcBob Wilson 24956248065194778c866164b0c10f09f0f0d91b91acChris Lattner if (CallSite CS = U) { 2496081f80078dccf02c1f9c61378ff88bbf1b4afb5eNick Lewycky // If this is the function being called then we treat it like a load and 2497081f80078dccf02c1f9c61378ff88bbf1b4afb5eNick Lewycky // ignore it. 2498081f80078dccf02c1f9c61378ff88bbf1b4afb5eNick Lewycky if (CS.isCallee(UI)) 2499081f80078dccf02c1f9c61378ff88bbf1b4afb5eNick Lewycky continue; 25006974302e3ff20746268721959efed807c7711bfcBob Wilson 25015389210e638401b8982b6de7c4e4a16999007035Duncan Sands // If this is a readonly/readnone call site, then we know it is just a 25025389210e638401b8982b6de7c4e4a16999007035Duncan Sands // load (but one that potentially returns the value itself), so we can 25035389210e638401b8982b6de7c4e4a16999007035Duncan Sands // ignore it if we know that the value isn't captured. 25045389210e638401b8982b6de7c4e4a16999007035Duncan Sands unsigned ArgNo = CS.getArgumentNo(UI); 25055389210e638401b8982b6de7c4e4a16999007035Duncan Sands if (CS.onlyReadsMemory() && 25065389210e638401b8982b6de7c4e4a16999007035Duncan Sands (CS.getInstruction()->use_empty() || 25075389210e638401b8982b6de7c4e4a16999007035Duncan Sands CS.paramHasAttr(ArgNo+1, Attribute::NoCapture))) 25085389210e638401b8982b6de7c4e4a16999007035Duncan Sands continue; 25095389210e638401b8982b6de7c4e4a16999007035Duncan Sands 25106248065194778c866164b0c10f09f0f0d91b91acChris Lattner // If this is being passed as a byval argument, the caller is making a 25116248065194778c866164b0c10f09f0f0d91b91acChris Lattner // copy, so it is only a read of the alloca. 25126248065194778c866164b0c10f09f0f0d91b91acChris Lattner if (CS.paramHasAttr(ArgNo+1, Attribute::ByVal)) 25136248065194778c866164b0c10f09f0f0d91b91acChris Lattner continue; 25146248065194778c866164b0c10f09f0f0d91b91acChris Lattner } 25156974302e3ff20746268721959efed807c7711bfcBob Wilson 251679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If this is isn't our memcpy/memmove, reject it as something we can't 251779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // handle. 251831d80103d56c026403d7fb6c50833664ff63ddcbChris Lattner MemTransferInst *MI = dyn_cast<MemTransferInst>(U); 251931d80103d56c026403d7fb6c50833664ff63ddcbChris Lattner if (MI == 0) 252079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return false; 25216974302e3ff20746268721959efed807c7711bfcBob Wilson 25222e61849f45144f2f05d57b00947df7e101610694Chris Lattner // If the transfer is using the alloca as a source of the transfer, then 25232e29ebd9e8efefe3ff926aa99cf2e5323665998eChris Lattner // ignore it since it is a load (unless the transfer is volatile). 25242e61849f45144f2f05d57b00947df7e101610694Chris Lattner if (UI.getOperandNo() == 1) { 25252e61849f45144f2f05d57b00947df7e101610694Chris Lattner if (MI->isVolatile()) return false; 25262e61849f45144f2f05d57b00947df7e101610694Chris Lattner continue; 25272e61849f45144f2f05d57b00947df7e101610694Chris Lattner } 252879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 252979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If we already have seen a copy, reject the second one. 253079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (TheCopy) return false; 25316974302e3ff20746268721959efed807c7711bfcBob Wilson 253279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If the pointer has been offset from the start of the alloca, we can't 253379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // safely handle this. 253479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (isOffset) return false; 253579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 253679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If the memintrinsic isn't using the alloca as the dest, reject it. 2537a6aac4c5bc22bb10c7adb11eee3f82c703af7002Gabor Greif if (UI.getOperandNo() != 0) return false; 25386974302e3ff20746268721959efed807c7711bfcBob Wilson 253979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If the source of the memcpy/move is not a constant global, reject it. 254031d80103d56c026403d7fb6c50833664ff63ddcbChris Lattner if (!PointsToConstantGlobal(MI->getSource())) 254179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return false; 25426974302e3ff20746268721959efed807c7711bfcBob Wilson 254379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // Otherwise, the transform is safe. Remember the copy instruction. 254479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner TheCopy = MI; 254579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner } 254679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return true; 254779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner} 254879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 254979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// isOnlyCopiedFromConstantGlobal - Return true if the specified alloca is only 255079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// modified by a copy from a constant global. If we can prove this, we can 255179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// replace any uses of the alloca with uses of the global directly. 255231d80103d56c026403d7fb6c50833664ff63ddcbChris LattnerMemTransferInst *SROA::isOnlyCopiedFromConstantGlobal(AllocaInst *AI) { 255331d80103d56c026403d7fb6c50833664ff63ddcbChris Lattner MemTransferInst *TheCopy = 0; 255479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (::isOnlyCopiedFromConstantGlobal(AI, TheCopy, false)) 255579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return TheCopy; 255679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return 0; 255779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner} 2558