ScalarReplAggregates.cpp revision 800de31776356910eb877e71df9f32b0a6215324
1ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner//===- ScalarReplAggregates.cpp - Scalar Replacement of Aggregates --------===// 2fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman// 3b576c94c15af9a440f69d9d03c2afead7971118cJohn Criswell// The LLVM Compiler Infrastructure 4b576c94c15af9a440f69d9d03c2afead7971118cJohn Criswell// 54ee451de366474b9c228b4e5fa573795a715216dChris Lattner// This file is distributed under the University of Illinois Open Source 64ee451de366474b9c228b4e5fa573795a715216dChris Lattner// License. See LICENSE.TXT for details. 7fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman// 8b576c94c15af9a440f69d9d03c2afead7971118cJohn Criswell//===----------------------------------------------------------------------===// 9ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner// 10ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner// This transformation implements the well known scalar replacement of 11ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner// aggregates transformation. This xform breaks up alloca instructions of 12ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner// aggregate type (structure or array) into individual alloca instructions for 1338aec325604635380421a27e39ab06d55ed2458dChris Lattner// each member (if possible). Then, if possible, it transforms the individual 1438aec325604635380421a27e39ab06d55ed2458dChris Lattner// alloca instructions into nice clean scalar SSA form. 1538aec325604635380421a27e39ab06d55ed2458dChris Lattner// 1638aec325604635380421a27e39ab06d55ed2458dChris Lattner// This combines a simple SRoA algorithm with the Mem2Reg algorithm because 1738aec325604635380421a27e39ab06d55ed2458dChris Lattner// often interact, especially for C++ programs. As such, iterating between 1838aec325604635380421a27e39ab06d55ed2458dChris Lattner// SRoA, then Mem2Reg until we run out of things to promote works well. 19ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner// 20ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner//===----------------------------------------------------------------------===// 21ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 220e5f499638c8d277b9dc4a4385712177c53b5681Chris Lattner#define DEBUG_TYPE "scalarrepl" 23ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner#include "llvm/Transforms/Scalar.h" 2438aec325604635380421a27e39ab06d55ed2458dChris Lattner#include "llvm/Constants.h" 2538aec325604635380421a27e39ab06d55ed2458dChris Lattner#include "llvm/DerivedTypes.h" 26ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner#include "llvm/Function.h" 2779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner#include "llvm/GlobalVariable.h" 28d8e1eea678833cc2b15e4ea69a5a403ba9c3b013Misha Brukman#include "llvm/Instructions.h" 29372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner#include "llvm/IntrinsicInst.h" 30372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner#include "llvm/Pass.h" 3138aec325604635380421a27e39ab06d55ed2458dChris Lattner#include "llvm/Analysis/Dominators.h" 3238aec325604635380421a27e39ab06d55ed2458dChris Lattner#include "llvm/Target/TargetData.h" 3338aec325604635380421a27e39ab06d55ed2458dChris Lattner#include "llvm/Transforms/Utils/PromoteMemToReg.h" 349525528a7dc5462b6374d38c81ba5c07b11741feChris Lattner#include "llvm/Support/Debug.h" 35a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner#include "llvm/Support/GetElementPtrTypeIterator.h" 36a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner#include "llvm/Support/MathExtras.h" 37a4f0b3a084d120cfc5b5bb06f64b222f5cb72740Chris Lattner#include "llvm/Support/Compiler.h" 381ccd185cb49d81465a2901622e58ceae046d1d83Chris Lattner#include "llvm/ADT/SmallVector.h" 39551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/Statistic.h" 40551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/StringExtras.h" 41d8664730942beb911327336d1f9db8e7efcd6813Chris Lattnerusing namespace llvm; 42d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 430e5f499638c8d277b9dc4a4385712177c53b5681Chris LattnerSTATISTIC(NumReplaced, "Number of allocas broken up"); 440e5f499638c8d277b9dc4a4385712177c53b5681Chris LattnerSTATISTIC(NumPromoted, "Number of allocas promoted"); 450e5f499638c8d277b9dc4a4385712177c53b5681Chris LattnerSTATISTIC(NumConverted, "Number of aggregates converted to scalar"); 4679b3bd395dc3303cde65e18e0524ed2f70268c99Chris LattnerSTATISTIC(NumGlobals, "Number of allocas copied from constant global"); 47ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 480e5f499638c8d277b9dc4a4385712177c53b5681Chris Lattnernamespace { 499525528a7dc5462b6374d38c81ba5c07b11741feChris Lattner struct VISIBILITY_HIDDEN SROA : public FunctionPass { 50ecd94c804a563f2a86572dcf1d2e81f397e19daaNick Lewycky static char ID; // Pass identification, replacement for typeid 51c2bbfc18e9adbbdcf5b3375d8d25e2452f7df7f1Dan Gohman explicit SROA(signed T = -1) : FunctionPass((intptr_t)&ID) { 52ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel if (T == -1) 53b0e71edb6b33f822e001500dac90acf95faacea8Chris Lattner SRThreshold = 128; 54ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel else 55ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel SRThreshold = T; 56ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel } 57794fd75c67a2cdc128d67342c6d88a504d186896Devang Patel 58ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner bool runOnFunction(Function &F); 59ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 6038aec325604635380421a27e39ab06d55ed2458dChris Lattner bool performScalarRepl(Function &F); 6138aec325604635380421a27e39ab06d55ed2458dChris Lattner bool performPromotion(Function &F); 6238aec325604635380421a27e39ab06d55ed2458dChris Lattner 63a15854c9febcb60eb107048640b04abff8cc47e5Chris Lattner // getAnalysisUsage - This pass does not require any passes, but we know it 64a15854c9febcb60eb107048640b04abff8cc47e5Chris Lattner // will not alter the CFG, so say so. 65a15854c9febcb60eb107048640b04abff8cc47e5Chris Lattner virtual void getAnalysisUsage(AnalysisUsage &AU) const { 66326821ef12c911af1d785e305e81dc3c07e456a5Devang Patel AU.addRequired<DominatorTree>(); 6738aec325604635380421a27e39ab06d55ed2458dChris Lattner AU.addRequired<DominanceFrontier>(); 6838aec325604635380421a27e39ab06d55ed2458dChris Lattner AU.addRequired<TargetData>(); 69a15854c9febcb60eb107048640b04abff8cc47e5Chris Lattner AU.setPreservesCFG(); 70a15854c9febcb60eb107048640b04abff8cc47e5Chris Lattner } 71a15854c9febcb60eb107048640b04abff8cc47e5Chris Lattner 72ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner private: 7339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// AllocaInfo - When analyzing uses of an alloca instruction, this captures 7439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// information about the uses. All these fields are initialized to false 7539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// and set to true when something is learned. 7639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner struct AllocaInfo { 7739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// isUnsafe - This is set to true if the alloca cannot be SROA'd. 7839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner bool isUnsafe : 1; 7939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 8039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// needsCanon - This is set to true if there is some use of the alloca 8139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// that requires canonicalization. 8239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner bool needsCanon : 1; 8339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 8439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner /// isMemCpySrc - This is true if this aggregate is memcpy'd from. 8539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner bool isMemCpySrc : 1; 8639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 8733b0b8d242de8d428f11e77ea734a08b47797216Zhou Sheng /// isMemCpyDst - This is true if this aggregate is memcpy'd into. 8839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner bool isMemCpyDst : 1; 8939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 9039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo() 9139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner : isUnsafe(false), needsCanon(false), 9239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isMemCpySrc(false), isMemCpyDst(false) {} 9339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner }; 9439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 95ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel unsigned SRThreshold; 96ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel 9739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner void MarkUnsafe(AllocaInfo &I) { I.isUnsafe = true; } 9839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 99f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner int isSafeAllocaToScalarRepl(AllocationInst *AI); 10039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 10139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner void isSafeUseOfAllocation(Instruction *User, AllocationInst *AI, 10239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo &Info); 10339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner void isSafeElementUse(Value *Ptr, bool isFirstElt, AllocationInst *AI, 10439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo &Info); 10539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner void isSafeMemIntrinsicOnAllocation(MemIntrinsic *MI, AllocationInst *AI, 10639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner unsigned OpNo, AllocaInfo &Info); 10739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner void isSafeUseOfBitCastedAllocation(BitCastInst *User, AllocationInst *AI, 10839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo &Info); 10939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 110a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner void DoScalarReplacement(AllocationInst *AI, 111a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner std::vector<AllocationInst*> &WorkList); 112f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner void CanonicalizeAllocaUsers(AllocationInst *AI); 113ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner AllocaInst *AddNewAlloca(Function &F, const Type *Ty, AllocationInst *Base); 114a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1158bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner void RewriteBitCastUserOfAlloca(Instruction *BCInst, AllocationInst *AI, 116372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner SmallVector<AllocaInst*, 32> &NewElts); 117372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 118a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *CanConvertToScalar(Value *V, bool &IsNotTrivial); 119a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner void ConvertToScalar(AllocationInst *AI, const Type *Ty); 120a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner void ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI, unsigned Offset); 121800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *ConvertUsesOfLoadToScalar(LoadInst *LI, AllocaInst *NewAI, 122800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned Offset); 123800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *ConvertUsesOfStoreToScalar(StoreInst *SI, AllocaInst *NewAI, 124800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned Offset); 12579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner static Instruction *isOnlyCopiedFromConstantGlobal(AllocationInst *AI); 126ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner }; 127ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 1281997473cf72957d0e70322e2fe6fe2ab141c58a6Devang Patel char SROA::ID = 0; 1297f8897f22e88271cfa114998a4d6088e7c8e8e11Chris Lattner RegisterPass<SROA> X("scalarrepl", "Scalar Replacement of Aggregates"); 130ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner} 131ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 132d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke// Public interface to the ScalarReplAggregates pass 133ff366850aa9956e167e78d4f5b57aae10d8c5779Devang PatelFunctionPass *llvm::createScalarReplAggregatesPass(signed int Threshold) { 134ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel return new SROA(Threshold); 135ff366850aa9956e167e78d4f5b57aae10d8c5779Devang Patel} 136ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 137ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 138ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattnerbool SROA::runOnFunction(Function &F) { 139fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner bool Changed = performPromotion(F); 140fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner while (1) { 141fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner bool LocalChange = performScalarRepl(F); 142fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner if (!LocalChange) break; // No need to repromote if no scalarrepl 143fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner Changed = true; 144fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner LocalChange = performPromotion(F); 145fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner if (!LocalChange) break; // No need to re-scalarrepl if no promotion 146fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner } 14738aec325604635380421a27e39ab06d55ed2458dChris Lattner 14838aec325604635380421a27e39ab06d55ed2458dChris Lattner return Changed; 14938aec325604635380421a27e39ab06d55ed2458dChris Lattner} 15038aec325604635380421a27e39ab06d55ed2458dChris Lattner 15138aec325604635380421a27e39ab06d55ed2458dChris Lattner 15238aec325604635380421a27e39ab06d55ed2458dChris Lattnerbool SROA::performPromotion(Function &F) { 15338aec325604635380421a27e39ab06d55ed2458dChris Lattner std::vector<AllocaInst*> Allocas; 154326821ef12c911af1d785e305e81dc3c07e456a5Devang Patel DominatorTree &DT = getAnalysis<DominatorTree>(); 15543f820d1f7638656be2158efac7dd8f5b08b8b77Chris Lattner DominanceFrontier &DF = getAnalysis<DominanceFrontier>(); 15638aec325604635380421a27e39ab06d55ed2458dChris Lattner 15702a3be020a6b4eedb4b489959997d23a22cdf22eChris Lattner BasicBlock &BB = F.getEntryBlock(); // Get the entry node for the function 15838aec325604635380421a27e39ab06d55ed2458dChris Lattner 159fe7ea0da17a1b5150aabbc2e82c5f4a0750dc23eChris Lattner bool Changed = false; 160fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 16138aec325604635380421a27e39ab06d55ed2458dChris Lattner while (1) { 16238aec325604635380421a27e39ab06d55ed2458dChris Lattner Allocas.clear(); 16338aec325604635380421a27e39ab06d55ed2458dChris Lattner 16438aec325604635380421a27e39ab06d55ed2458dChris Lattner // Find allocas that are safe to promote, by looking at all instructions in 16538aec325604635380421a27e39ab06d55ed2458dChris Lattner // the entry node 16638aec325604635380421a27e39ab06d55ed2458dChris Lattner for (BasicBlock::iterator I = BB.begin(), E = --BB.end(); I != E; ++I) 16738aec325604635380421a27e39ab06d55ed2458dChris Lattner if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) // Is it an alloca? 16841968df51e11f581eb19c8f68a8cb2f4e8acc1c5Devang Patel if (isAllocaPromotable(AI)) 16938aec325604635380421a27e39ab06d55ed2458dChris Lattner Allocas.push_back(AI); 17038aec325604635380421a27e39ab06d55ed2458dChris Lattner 17138aec325604635380421a27e39ab06d55ed2458dChris Lattner if (Allocas.empty()) break; 17238aec325604635380421a27e39ab06d55ed2458dChris Lattner 173326821ef12c911af1d785e305e81dc3c07e456a5Devang Patel PromoteMemToReg(Allocas, DT, DF); 17438aec325604635380421a27e39ab06d55ed2458dChris Lattner NumPromoted += Allocas.size(); 17538aec325604635380421a27e39ab06d55ed2458dChris Lattner Changed = true; 17638aec325604635380421a27e39ab06d55ed2458dChris Lattner } 17738aec325604635380421a27e39ab06d55ed2458dChris Lattner 17838aec325604635380421a27e39ab06d55ed2458dChris Lattner return Changed; 17938aec325604635380421a27e39ab06d55ed2458dChris Lattner} 18038aec325604635380421a27e39ab06d55ed2458dChris Lattner 18138aec325604635380421a27e39ab06d55ed2458dChris Lattner// performScalarRepl - This algorithm is a simple worklist driven algorithm, 18238aec325604635380421a27e39ab06d55ed2458dChris Lattner// which runs on all of the malloc/alloca instructions in the function, removing 18338aec325604635380421a27e39ab06d55ed2458dChris Lattner// them if they are only used by getelementptr instructions. 18438aec325604635380421a27e39ab06d55ed2458dChris Lattner// 18538aec325604635380421a27e39ab06d55ed2458dChris Lattnerbool SROA::performScalarRepl(Function &F) { 186ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner std::vector<AllocationInst*> WorkList; 187ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 188ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner // Scan the entry basic block, adding any alloca's and mallocs to the worklist 18902a3be020a6b4eedb4b489959997d23a22cdf22eChris Lattner BasicBlock &BB = F.getEntryBlock(); 190ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E; ++I) 191ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner if (AllocationInst *A = dyn_cast<AllocationInst>(I)) 192ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner WorkList.push_back(A); 193ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 1947139406707eb3869183fd6a3329fe4a77d309692Chris Lattner const TargetData &TD = getAnalysis<TargetData>(); 1957139406707eb3869183fd6a3329fe4a77d309692Chris Lattner 196ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner // Process the worklist 197ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner bool Changed = false; 198ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner while (!WorkList.empty()) { 199ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner AllocationInst *AI = WorkList.back(); 200ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner WorkList.pop_back(); 201a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 202add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner // Handle dead allocas trivially. These can be formed by SROA'ing arrays 203add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner // with unused elements. 204add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner if (AI->use_empty()) { 205add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner AI->eraseFromParent(); 206add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner continue; 207add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner } 208add2bd7f5941537a97a41e037ae2277fbeed0b4fChris Lattner 209a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // If we can turn this aggregate value (potentially with casts) into a 210a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // simple scalar value that can be mem2reg'd into a register value. 211a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner bool IsNotTrivial = false; 212a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (const Type *ActualType = CanConvertToScalar(AI, IsNotTrivial)) 213df4f226cdcbe853984ddda10aa0d53590d35b97eChris Lattner if (IsNotTrivial && ActualType != Type::VoidTy) { 214a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner ConvertToScalar(AI, ActualType); 215a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner Changed = true; 216a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner continue; 217a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 218ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 21979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // Check to see if we can perform the core SROA transformation. We cannot 22079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // transform the allocation instruction if it is an array allocation 22179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // (allocations OF arrays are ok though), and an allocation of a scalar 22279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // value cannot be decomposed at all. 223a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner if (!AI->isArrayAllocation() && 224a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner (isa<StructType>(AI->getAllocatedType()) || 2257139406707eb3869183fd6a3329fe4a77d309692Chris Lattner isa<ArrayType>(AI->getAllocatedType())) && 2267139406707eb3869183fd6a3329fe4a77d309692Chris Lattner AI->getAllocatedType()->isSized() && 2273cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands TD.getABITypeSize(AI->getAllocatedType()) < SRThreshold) { 228a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Check that all of the users of the allocation are capable of being 229a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // transformed. 230a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner switch (isSafeAllocaToScalarRepl(AI)) { 231a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner default: assert(0 && "Unexpected value!"); 232a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner case 0: // Not safe to scalar replace. 233a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner break; 234a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner case 1: // Safe, but requires cleanup/canonicalizations first 235a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner CanonicalizeAllocaUsers(AI); 236a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // FALL THROUGH. 237a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner case 3: // Safe to scalar replace. 238a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner DoScalarReplacement(AI, WorkList); 239a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner Changed = true; 240a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner continue; 241a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 242f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner } 24379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 24479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // Check to see if this allocation is only modified by a memcpy/memmove from 24579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // a constant global. If this is the case, we can change all users to use 24679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // the constant global instead. This is commonly produced by the CFE by 24779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // constructs like "void foo() { int A[] = {1,2,3,4,5,6,7,8,9...}; }" if 'A' 24879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // is only subsequently read. 24979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (Instruction *TheCopy = isOnlyCopiedFromConstantGlobal(AI)) { 25079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner DOUT << "Found alloca equal to global: " << *AI; 25179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner DOUT << " memcpy = " << *TheCopy; 25279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner Constant *TheSrc = cast<Constant>(TheCopy->getOperand(2)); 25379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner AI->replaceAllUsesWith(ConstantExpr::getBitCast(TheSrc, AI->getType())); 25479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner TheCopy->eraseFromParent(); // Don't mutate the global. 25579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner AI->eraseFromParent(); 25679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner ++NumGlobals; 25779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner Changed = true; 25879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner continue; 25979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner } 260a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner 261a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Otherwise, couldn't process this. 262a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 263ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 264a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner return Changed; 265a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner} 266fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 267a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner/// DoScalarReplacement - This alloca satisfied the isSafeAllocaToScalarRepl 268a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner/// predicate, do SROA now. 269a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattnervoid SROA::DoScalarReplacement(AllocationInst *AI, 270a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner std::vector<AllocationInst*> &WorkList) { 27179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner DOUT << "Found inst to SROA: " << *AI; 272a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner SmallVector<AllocaInst*, 32> ElementAllocas; 273a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner if (const StructType *ST = dyn_cast<StructType>(AI->getAllocatedType())) { 274a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner ElementAllocas.reserve(ST->getNumContainedTypes()); 275a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner for (unsigned i = 0, e = ST->getNumContainedTypes(); i != e; ++i) { 276a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AllocaInst *NA = new AllocaInst(ST->getContainedType(i), 0, 277a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AI->getAlignment(), 278a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AI->getName() + "." + utostr(i), AI); 279a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner ElementAllocas.push_back(NA); 280a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner WorkList.push_back(NA); // Add to worklist for recursive processing 281a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 282a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } else { 283a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner const ArrayType *AT = cast<ArrayType>(AI->getAllocatedType()); 284a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner ElementAllocas.reserve(AT->getNumElements()); 285a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner const Type *ElTy = AT->getElementType(); 286a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner for (unsigned i = 0, e = AT->getNumElements(); i != e; ++i) { 287a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AllocaInst *NA = new AllocaInst(ElTy, 0, AI->getAlignment(), 288a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AI->getName() + "." + utostr(i), AI); 289a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner ElementAllocas.push_back(NA); 290a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner WorkList.push_back(NA); // Add to worklist for recursive processing 291ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner } 292a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 293fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 294a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Now that we have created the alloca instructions that we want to use, 295a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // expand the getelementptr instructions to use them. 296a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // 297a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner while (!AI->use_empty()) { 298a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner Instruction *User = cast<Instruction>(AI->use_back()); 299a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner if (BitCastInst *BCInst = dyn_cast<BitCastInst>(User)) { 300a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner RewriteBitCastUserOfAlloca(BCInst, AI, ElementAllocas); 301a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner BCInst->eraseFromParent(); 302a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner continue; 303a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 304a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner 305a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner GetElementPtrInst *GEPI = cast<GetElementPtrInst>(User); 306a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // We now know that the GEP is of the form: GEP <ptr>, 0, <cst> 307a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner unsigned Idx = 308a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner (unsigned)cast<ConstantInt>(GEPI->getOperand(2))->getZExtValue(); 309a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner 310a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner assert(Idx < ElementAllocas.size() && "Index out of range?"); 311a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AllocaInst *AllocaToUse = ElementAllocas[Idx]; 312a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner 313a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner Value *RepValue; 314a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner if (GEPI->getNumOperands() == 3) { 315a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Do not insert a new getelementptr instruction with zero indices, only 316a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // to have it optimized out later. 317a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner RepValue = AllocaToUse; 318a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } else { 319a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // We are indexing deeply into the structure, so we still need a 320a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // getelement ptr instruction to finish the indexing. This may be 321a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // expanded itself once the worklist is rerun. 322a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // 323a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner SmallVector<Value*, 8> NewArgs; 324a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner NewArgs.push_back(Constant::getNullValue(Type::Int32Ty)); 325a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner NewArgs.append(GEPI->op_begin()+3, GEPI->op_end()); 326b8f74793b9d161bc666fe27fc92fe112b6ec169bDavid Greene RepValue = new GetElementPtrInst(AllocaToUse, NewArgs.begin(), 327b8f74793b9d161bc666fe27fc92fe112b6ec169bDavid Greene NewArgs.end(), "", GEPI); 328a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner RepValue->takeName(GEPI); 329a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 330a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner 331a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // If this GEP is to the start of the aggregate, check for memcpys. 332a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner if (Idx == 0) { 333a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner bool IsStartOfAggregateGEP = true; 334a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner for (unsigned i = 3, e = GEPI->getNumOperands(); i != e; ++i) { 335a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner if (!isa<ConstantInt>(GEPI->getOperand(i))) { 336a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner IsStartOfAggregateGEP = false; 337a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner break; 338a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner } 339a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner if (!cast<ConstantInt>(GEPI->getOperand(i))->isZero()) { 340a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner IsStartOfAggregateGEP = false; 341a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner break; 3428bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner } 3438bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner } 3448bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 345a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner if (IsStartOfAggregateGEP) 346a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner RewriteBitCastUserOfAlloca(GEPI, AI, ElementAllocas); 347ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner } 348a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner 349ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 350a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Move all of the users over to the new GEP. 351a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner GEPI->replaceAllUsesWith(RepValue); 352a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Delete the old GEP 353a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner GEPI->eraseFromParent(); 354ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner } 355ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner 356a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner // Finally, delete the Alloca instruction 357a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner AI->eraseFromParent(); 358a10b29b84b63c448b7cb423598d3a38b0f55cddbChris Lattner NumReplaced++; 359ed7b41ea90a17c826f195acbc456c4bb733113d6Chris Lattner} 3605e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner 3615e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner 362f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// isSafeElementUse - Check to see if this use is an allowed use for a 3638bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// getelementptr instruction of an array aggregate allocation. isFirstElt 3648bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// indicates whether Ptr is known to the start of the aggregate. 365f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// 36639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattnervoid SROA::isSafeElementUse(Value *Ptr, bool isFirstElt, AllocationInst *AI, 36739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo &Info) { 368f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner for (Value::use_iterator I = Ptr->use_begin(), E = Ptr->use_end(); 369f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner I != E; ++I) { 370f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner Instruction *User = cast<Instruction>(*I); 371f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner switch (User->getOpcode()) { 372f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner case Instruction::Load: break; 373f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner case Instruction::Store: 374f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner // Store is ok if storing INTO the pointer, not storing the pointer 37539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (User->getOperand(0) == Ptr) return MarkUnsafe(Info); 376f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner break; 377f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner case Instruction::GetElementPtr: { 378f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner GetElementPtrInst *GEP = cast<GetElementPtrInst>(User); 3798bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner bool AreAllZeroIndices = isFirstElt; 380f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner if (GEP->getNumOperands() > 1) { 3818bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner if (!isa<ConstantInt>(GEP->getOperand(1)) || 3828bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner !cast<ConstantInt>(GEP->getOperand(1))->isZero()) 38339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // Using pointer arithmetic to navigate the array. 38439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 3858bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 3868bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner if (AreAllZeroIndices) { 3878bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner for (unsigned i = 2, e = GEP->getNumOperands(); i != e; ++i) { 3888bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner if (!isa<ConstantInt>(GEP->getOperand(i)) || 3898bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner !cast<ConstantInt>(GEP->getOperand(i))->isZero()) { 3908bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner AreAllZeroIndices = false; 3918bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner break; 3928bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner } 3938bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner } 3948bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner } 395f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner } 39639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isSafeElementUse(GEP, AreAllZeroIndices, AI, Info); 39739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (Info.isUnsafe) return; 398f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner break; 399f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner } 4008bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner case Instruction::BitCast: 40139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (isFirstElt) { 40239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isSafeUseOfBitCastedAllocation(cast<BitCastInst>(User), AI, Info); 40339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (Info.isUnsafe) return; 4048bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner break; 40539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 4068bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner DOUT << " Transformation preventing inst: " << *User; 40739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 4088bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner case Instruction::Call: 4098bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(User)) { 41039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (isFirstElt) { 41139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isSafeMemIntrinsicOnAllocation(MI, AI, I.getOperandNo(), Info); 41239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (Info.isUnsafe) return; 4138bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner break; 41439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 4158bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner } 4168bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner DOUT << " Transformation preventing inst: " << *User; 41739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 418f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner default: 419b7427031372337e6d67f9573ec6c722ab5ea913eBill Wendling DOUT << " Transformation preventing inst: " << *User; 42039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 421f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner } 422f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner } 42339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return; // All users look ok :) 424f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner} 425f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner 426d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner/// AllUsersAreLoads - Return true if all users of this value are loads. 427d878ecd904e4469344a2274f9784422c2c68b81cChris Lattnerstatic bool AllUsersAreLoads(Value *Ptr) { 428d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner for (Value::use_iterator I = Ptr->use_begin(), E = Ptr->use_end(); 429d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner I != E; ++I) 430d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner if (cast<Instruction>(*I)->getOpcode() != Instruction::Load) 431d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner return false; 432fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman return true; 433d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner} 434d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner 4355e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner/// isSafeUseOfAllocation - Check to see if this user is an allowed use for an 4365e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner/// aggregate allocation. 4375e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner/// 43839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattnervoid SROA::isSafeUseOfAllocation(Instruction *User, AllocationInst *AI, 43939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo &Info) { 440372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (BitCastInst *C = dyn_cast<BitCastInst>(User)) 44139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return isSafeUseOfBitCastedAllocation(C, AI, Info); 44239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 44339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(User); 44439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (GEPI == 0) 44539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 446546fc40d69ce4051b48112aafedd1e41f4a13195Chris Lattner 447be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner gep_type_iterator I = gep_type_begin(GEPI), E = gep_type_end(GEPI); 448be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner 44925de486263abc1882498a8701e3eb29ee0804c4eChris Lattner // The GEP is not safe to transform if not of the form "GEP <ptr>, 0, <cst>". 450be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner if (I == E || 45139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner I.getOperand() != Constant::getNullValue(I.getOperand()->getType())) { 45239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 45339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 454be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner 455be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner ++I; 45639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (I == E) return MarkUnsafe(Info); // ran out of GEP indices?? 457546fc40d69ce4051b48112aafedd1e41f4a13195Chris Lattner 4588bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner bool IsAllZeroIndices = true; 4598bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 460be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner // If this is a use of an array allocation, do a bit more checking for sanity. 461be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner if (const ArrayType *AT = dyn_cast<ArrayType>(*I)) { 462be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner uint64_t NumElements = AT->getNumElements(); 463d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner 4648bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner if (ConstantInt *Idx = dyn_cast<ConstantInt>(I.getOperand())) { 4658bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner IsAllZeroIndices &= Idx->isZero(); 4668bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 467d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // Check to make sure that index falls within the array. If not, 468d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // something funny is going on, so we won't do the optimization. 469d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // 4708bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner if (Idx->getZExtValue() >= NumElements) 47139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 472fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 47325de486263abc1882498a8701e3eb29ee0804c4eChris Lattner // We cannot scalar repl this level of the array unless any array 47425de486263abc1882498a8701e3eb29ee0804c4eChris Lattner // sub-indices are in-range constants. In particular, consider: 47525de486263abc1882498a8701e3eb29ee0804c4eChris Lattner // A[0][i]. We cannot know that the user isn't doing invalid things like 47625de486263abc1882498a8701e3eb29ee0804c4eChris Lattner // allowing i to index an out-of-range subscript that accesses A[1]. 47725de486263abc1882498a8701e3eb29ee0804c4eChris Lattner // 47825de486263abc1882498a8701e3eb29ee0804c4eChris Lattner // Scalar replacing *just* the outer index of the array is probably not 47925de486263abc1882498a8701e3eb29ee0804c4eChris Lattner // going to be a win anyway, so just give up. 4809d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer for (++I; I != E && (isa<ArrayType>(*I) || isa<VectorType>(*I)); ++I) { 481d92515034fc4157850b981f696702cc2f35733f0Chris Lattner uint64_t NumElements; 482d92515034fc4157850b981f696702cc2f35733f0Chris Lattner if (const ArrayType *SubArrayTy = dyn_cast<ArrayType>(*I)) 483d92515034fc4157850b981f696702cc2f35733f0Chris Lattner NumElements = SubArrayTy->getNumElements(); 484d92515034fc4157850b981f696702cc2f35733f0Chris Lattner else 4859d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer NumElements = cast<VectorType>(*I)->getNumElements(); 486d92515034fc4157850b981f696702cc2f35733f0Chris Lattner 4878bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner ConstantInt *IdxVal = dyn_cast<ConstantInt>(I.getOperand()); 48839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (!IdxVal) return MarkUnsafe(Info); 4898bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner if (IdxVal->getZExtValue() >= NumElements) 49039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 4918bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner IsAllZeroIndices &= IdxVal->isZero(); 49225de486263abc1882498a8701e3eb29ee0804c4eChris Lattner } 49325de486263abc1882498a8701e3eb29ee0804c4eChris Lattner 494d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } else { 4958bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner IsAllZeroIndices = 0; 4968bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 497d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // If this is an array index and the index is not constant, we cannot 498d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // promote... that is unless the array has exactly one or two elements in 499d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // it, in which case we CAN promote it, but we have to canonicalize this 500d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // out if this is the only problem. 50125de486263abc1882498a8701e3eb29ee0804c4eChris Lattner if ((NumElements == 1 || NumElements == 2) && 50239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllUsersAreLoads(GEPI)) { 50339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner Info.needsCanon = true; 50439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return; // Canonicalization required! 50539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 50639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 507d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } 5085e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner } 509be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner 510be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner // If there are any non-simple uses of this getelementptr, make sure to reject 511be883a23ed64b83235d509ad0befc1d6aa6b0cd8Chris Lattner // them. 51239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return isSafeElementUse(GEPI, IsAllZeroIndices, AI, Info); 5138bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner} 5148bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 5158bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// isSafeMemIntrinsicOnAllocation - Return true if the specified memory 5168bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// intrinsic can be promoted by SROA. At this point, we know that the operand 5178bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// of the memintrinsic is a pointer to the beginning of the allocation. 51839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattnervoid SROA::isSafeMemIntrinsicOnAllocation(MemIntrinsic *MI, AllocationInst *AI, 51939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner unsigned OpNo, AllocaInfo &Info) { 5208bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner // If not constant length, give up. 5218bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner ConstantInt *Length = dyn_cast<ConstantInt>(MI->getLength()); 52239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (!Length) return MarkUnsafe(Info); 5238bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 5248bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner // If not the whole aggregate, give up. 5258bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner const TargetData &TD = getAnalysis<TargetData>(); 5263cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands if (Length->getZExtValue() != 5273cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands TD.getABITypeSize(AI->getType()->getElementType())) 52839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 5298bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 5308bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner // We only know about memcpy/memset/memmove. 5318bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner if (!isa<MemCpyInst>(MI) && !isa<MemSetInst>(MI) && !isa<MemMoveInst>(MI)) 53239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 53339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 53439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // Otherwise, we can transform it. Determine whether this is a memcpy/set 53539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // into or out of the aggregate. 53639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (OpNo == 1) 53739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner Info.isMemCpyDst = true; 53839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner else { 53939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner assert(OpNo == 2); 54039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner Info.isMemCpySrc = true; 54139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 5425e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner} 5435e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner 544372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner/// isSafeUseOfBitCastedAllocation - Return true if all users of this bitcast 545372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner/// are 54639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattnervoid SROA::isSafeUseOfBitCastedAllocation(BitCastInst *BC, AllocationInst *AI, 54739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo &Info) { 548372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner for (Value::use_iterator UI = BC->use_begin(), E = BC->use_end(); 549372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner UI != E; ++UI) { 550372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (BitCastInst *BCU = dyn_cast<BitCastInst>(UI)) { 55139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isSafeUseOfBitCastedAllocation(BCU, AI, Info); 552372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } else if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(UI)) { 55339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isSafeMemIntrinsicOnAllocation(MI, AI, UI.getOperandNo(), Info); 554372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } else { 55539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return MarkUnsafe(Info); 556372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 55739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (Info.isUnsafe) return; 558372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 559372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner} 560372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 5618bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// RewriteBitCastUserOfAlloca - BCInst (transitively) bitcasts AI, or indexes 5628bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// to its first element. Transform users of the cast to use the new values 5638bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner/// instead. 5648bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattnervoid SROA::RewriteBitCastUserOfAlloca(Instruction *BCInst, AllocationInst *AI, 565372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner SmallVector<AllocaInst*, 32> &NewElts) { 566372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner Constant *Zero = Constant::getNullValue(Type::Int32Ty); 567372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner const TargetData &TD = getAnalysis<TargetData>(); 5688bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 5698bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner Value::use_iterator UI = BCInst->use_begin(), UE = BCInst->use_end(); 5708bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner while (UI != UE) { 5718bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner if (BitCastInst *BCU = dyn_cast<BitCastInst>(*UI)) { 572372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner RewriteBitCastUserOfAlloca(BCU, AI, NewElts); 5738bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner ++UI; 5748bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner BCU->eraseFromParent(); 575372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner continue; 576372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 577372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 578372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // Otherwise, must be memcpy/memmove/memset of the entire aggregate. Split 579372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // into one per element. 5808bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner MemIntrinsic *MI = dyn_cast<MemIntrinsic>(*UI); 5818bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner 5828bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner // If it's not a mem intrinsic, it must be some other user of a gep of the 5838bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner // first pointer. Just leave these alone. 5848bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner if (!MI) { 5858bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner ++UI; 5868bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner continue; 5878bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner } 588372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 589372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // If this is a memcpy/memmove, construct the other pointer as the 590372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // appropriate type. 591372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner Value *OtherPtr = 0; 592372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (MemCpyInst *MCI = dyn_cast<MemCpyInst>(MI)) { 593372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (BCInst == MCI->getRawDest()) 594372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner OtherPtr = MCI->getRawSource(); 595372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner else { 596372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner assert(BCInst == MCI->getRawSource()); 597372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner OtherPtr = MCI->getRawDest(); 598372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 599372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } else if (MemMoveInst *MMI = dyn_cast<MemMoveInst>(MI)) { 600372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (BCInst == MMI->getRawDest()) 601372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner OtherPtr = MMI->getRawSource(); 602372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner else { 603372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner assert(BCInst == MMI->getRawSource()); 604372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner OtherPtr = MMI->getRawDest(); 605372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 606372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 607372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 608372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // If there is an other pointer, we want to convert it to the same pointer 609372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // type as AI has, so we can GEP through it. 610372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (OtherPtr) { 611372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // It is likely that OtherPtr is a bitcast, if so, remove it. 612372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (BitCastInst *BC = dyn_cast<BitCastInst>(OtherPtr)) 613372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner OtherPtr = BC->getOperand(0); 614372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (ConstantExpr *BCE = dyn_cast<ConstantExpr>(OtherPtr)) 615372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (BCE->getOpcode() == Instruction::BitCast) 616372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner OtherPtr = BCE->getOperand(0); 617372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 618372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // If the pointer is not the right type, insert a bitcast to the right 619372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // type. 620372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (OtherPtr->getType() != AI->getType()) 621372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner OtherPtr = new BitCastInst(OtherPtr, AI->getType(), OtherPtr->getName(), 622372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner MI); 623372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 624372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 625372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // Process each element of the aggregate. 626372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner Value *TheFn = MI->getOperand(0); 627372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner const Type *BytePtrTy = MI->getRawDest()->getType(); 628372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner bool SROADest = MI->getRawDest() == BCInst; 629372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 630372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner for (unsigned i = 0, e = NewElts.size(); i != e; ++i) { 631372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // If this is a memcpy/memmove, emit a GEP of the other element address. 632372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner Value *OtherElt = 0; 633372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (OtherPtr) { 634b8f74793b9d161bc666fe27fc92fe112b6ec169bDavid Greene Value *Idx[2]; 635b8f74793b9d161bc666fe27fc92fe112b6ec169bDavid Greene Idx[0] = Zero; 636b8f74793b9d161bc666fe27fc92fe112b6ec169bDavid Greene Idx[1] = ConstantInt::get(Type::Int32Ty, i); 637b8f74793b9d161bc666fe27fc92fe112b6ec169bDavid Greene OtherElt = new GetElementPtrInst(OtherPtr, Idx, Idx + 2, 638372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner OtherPtr->getNameStr()+"."+utostr(i), 639372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner MI); 640372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 641372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 642372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner Value *EltPtr = NewElts[i]; 643c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner const Type *EltTy =cast<PointerType>(EltPtr->getType())->getElementType(); 644c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner 645c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner // If we got down to a scalar, insert a load or store as appropriate. 646c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner if (EltTy->isFirstClassType()) { 647c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner if (isa<MemCpyInst>(MI) || isa<MemMoveInst>(MI)) { 648c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner Value *Elt = new LoadInst(SROADest ? OtherElt : EltPtr, "tmp", 649c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner MI); 650c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner new StoreInst(Elt, SROADest ? EltPtr : OtherElt, MI); 651c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner continue; 652c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } else { 653c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner assert(isa<MemSetInst>(MI)); 654c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner 655c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner // If the stored element is zero (common case), just store a null 656c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner // constant. 657c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner Constant *StoreVal; 658c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner if (ConstantInt *CI = dyn_cast<ConstantInt>(MI->getOperand(2))) { 659c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner if (CI->isZero()) { 660c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner StoreVal = Constant::getNullValue(EltTy); // 0.0, null, 0, <0,0> 661c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } else { 66207a96765daedf180a7102d39fe56c499878312b7Dan Gohman // If EltTy is a vector type, get the element type. 663c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner const Type *ValTy = EltTy; 664c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner if (const VectorType *VTy = dyn_cast<VectorType>(ValTy)) 665c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner ValTy = VTy->getElementType(); 6663cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 667c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner // Construct an integer with the right value. 6683cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands unsigned EltSize = TD.getTypeSizeInBits(ValTy); 6693cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands APInt OneVal(EltSize, CI->getZExtValue()); 670c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner APInt TotalVal(OneVal); 671c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner // Set each byte. 6723cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands for (unsigned i = 0; 8*i < EltSize; ++i) { 673c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner TotalVal = TotalVal.shl(8); 674c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner TotalVal |= OneVal; 675c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } 6763cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 677c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner // Convert the integer value to the appropriate type. 678c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner StoreVal = ConstantInt::get(TotalVal); 679c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner if (isa<PointerType>(ValTy)) 680c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner StoreVal = ConstantExpr::getIntToPtr(StoreVal, ValTy); 681c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner else if (ValTy->isFloatingPoint()) 682c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner StoreVal = ConstantExpr::getBitCast(StoreVal, ValTy); 683c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner assert(StoreVal->getType() == ValTy && "Type mismatch!"); 684c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner 685c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner // If the requested value was a vector constant, create it. 686c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner if (EltTy != ValTy) { 687c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner unsigned NumElts = cast<VectorType>(ValTy)->getNumElements(); 688c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner SmallVector<Constant*, 16> Elts(NumElts, StoreVal); 689c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner StoreVal = ConstantVector::get(&Elts[0], NumElts); 690c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } 691c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } 692c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner new StoreInst(StoreVal, EltPtr, MI); 693c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner continue; 694c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } 695c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner // Otherwise, if we're storing a byte variable, use a memset call for 696c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner // this element. 697c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } 698c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } 699372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 700372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // Cast the element pointer to BytePtrTy. 701372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (EltPtr->getType() != BytePtrTy) 702372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner EltPtr = new BitCastInst(EltPtr, BytePtrTy, EltPtr->getNameStr(), MI); 703c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner 704c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner // Cast the other pointer (if we have one) to BytePtrTy. 705c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner if (OtherElt && OtherElt->getType() != BytePtrTy) 706c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner OtherElt = new BitCastInst(OtherElt, BytePtrTy,OtherElt->getNameStr(), 707c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner MI); 708c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner 7093cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands unsigned EltSize = TD.getABITypeSize(EltTy); 710c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner 711372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // Finally, insert the meminst for this element. 712372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner if (isa<MemCpyInst>(MI) || isa<MemMoveInst>(MI)) { 713372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner Value *Ops[] = { 714372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner SROADest ? EltPtr : OtherElt, // Dest ptr 715372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner SROADest ? OtherElt : EltPtr, // Src ptr 716372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner ConstantInt::get(MI->getOperand(3)->getType(), EltSize), // Size 717372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner Zero // Align 718372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner }; 71952eec548206d0b135b55ba52dd0e82e978f15ae5David Greene new CallInst(TheFn, Ops, Ops + 4, "", MI); 720c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } else { 721c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner assert(isa<MemSetInst>(MI)); 722372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner Value *Ops[] = { 723372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner EltPtr, MI->getOperand(2), // Dest, Value, 724372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner ConstantInt::get(MI->getOperand(3)->getType(), EltSize), // Size 725372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner Zero // Align 726372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner }; 72752eec548206d0b135b55ba52dd0e82e978f15ae5David Greene new CallInst(TheFn, Ops, Ops + 4, "", MI); 728372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 729c14d3cac4bb5c798fbcc4b9cad87841ca087b017Chris Lattner } 730372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 731372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // Finally, MI is now dead, as we've modified its actions to occur on all of 732372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner // the elements of the aggregate. 7338bf991193245bb8b7e497e8c16545a206fbe5eefChris Lattner ++UI; 734372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner MI->eraseFromParent(); 735372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner } 736372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner} 737372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 7383cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands/// HasPadding - Return true if the specified type has any structure or 7393cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands/// alignment padding, false otherwise. 74018b0ca854fbeebbc48cf1f4473daa428e68f748cDuncan Sandsstatic bool HasPadding(const Type *Ty, const TargetData &TD, 74118b0ca854fbeebbc48cf1f4473daa428e68f748cDuncan Sands bool inPacked = false) { 74239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (const StructType *STy = dyn_cast<StructType>(Ty)) { 74339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner const StructLayout *SL = TD.getStructLayout(STy); 74439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner unsigned PrevFieldBitOffset = 0; 74539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { 7463cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands unsigned FieldBitOffset = SL->getElementOffsetInBits(i); 7473cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 74839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // Padding in sub-elements? 74918b0ca854fbeebbc48cf1f4473daa428e68f748cDuncan Sands if (HasPadding(STy->getElementType(i), TD, STy->isPacked())) 75039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return true; 7513cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 75239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // Check to see if there is any padding between this element and the 75339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // previous one. 75439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (i) { 7553cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands unsigned PrevFieldEnd = 75639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner PrevFieldBitOffset+TD.getTypeSizeInBits(STy->getElementType(i-1)); 75739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (PrevFieldEnd < FieldBitOffset) 75839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return true; 75939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 7603cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 76139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner PrevFieldBitOffset = FieldBitOffset; 76239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 7633cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 76439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // Check for tail padding. 76539a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (unsigned EltCount = STy->getNumElements()) { 76639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner unsigned PrevFieldEnd = PrevFieldBitOffset + 76739a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner TD.getTypeSizeInBits(STy->getElementType(EltCount-1)); 7683cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands if (PrevFieldEnd < SL->getSizeInBits()) 76939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return true; 77039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 77139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 77239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } else if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) { 77318b0ca854fbeebbc48cf1f4473daa428e68f748cDuncan Sands return HasPadding(ATy->getElementType(), TD, false); 7743cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands } else if (const VectorType *VTy = dyn_cast<VectorType>(Ty)) { 77518b0ca854fbeebbc48cf1f4473daa428e68f748cDuncan Sands return HasPadding(VTy->getElementType(), TD, false); 77639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner } 77718b0ca854fbeebbc48cf1f4473daa428e68f748cDuncan Sands return inPacked ? 77818b0ca854fbeebbc48cf1f4473daa428e68f748cDuncan Sands false : TD.getTypeSizeInBits(Ty) != TD.getABITypeSizeInBits(Ty); 77939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner} 780372dda8881c7a32a6f5ce0f76a713e3a9ef46ea1Chris Lattner 781f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// isSafeStructAllocaToScalarRepl - Check to see if the specified allocation of 782f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// an aggregate can be broken down into elements. Return 0 if not, 3 if safe, 783f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// or 1 if safe after canonicalization has been performed. 7845e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner/// 785f5990edc877c4e63503c589928a00ec6ec751830Chris Lattnerint SROA::isSafeAllocaToScalarRepl(AllocationInst *AI) { 7865e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner // Loop over the use list of the alloca. We can only transform it if all of 7875e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner // the users are safe to transform. 78839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner AllocaInfo Info; 78939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 7905e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner for (Value::use_iterator I = AI->use_begin(), E = AI->use_end(); 791f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner I != E; ++I) { 79239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner isSafeUseOfAllocation(cast<Instruction>(*I), AI, Info); 79339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (Info.isUnsafe) { 794b7427031372337e6d67f9573ec6c722ab5ea913eBill Wendling DOUT << "Cannot transform: " << *AI << " due to user: " << **I; 795f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner return 0; 7965e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner } 797f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner } 79839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner 79939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // Okay, we know all the users are promotable. If the aggregate is a memcpy 80039a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // source and destination, we have to be careful. In particular, the memcpy 80139a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // could be moving around elements that live in structure padding of the LLVM 80239a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // types, but may actually be used. In these cases, we refuse to promote the 80339a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // struct. 80439a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner if (Info.isMemCpySrc && Info.isMemCpyDst && 8053cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands HasPadding(AI->getType()->getElementType(), getAnalysis<TargetData>())) 80639a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return 0; 8073cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 80839a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner // If we require cleanup, return 1, otherwise return 3. 80939a1c04323a5993d6b2993e615ec44c16e19aeeaChris Lattner return Info.needsCanon ? 1 : 3; 810f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner} 811f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner 812f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// CanonicalizeAllocaUsers - If SROA reported that it can promote the specified 813f5990edc877c4e63503c589928a00ec6ec751830Chris Lattner/// allocation, but only if cleaned up, perform the cleanups required. 814f5990edc877c4e63503c589928a00ec6ec751830Chris Lattnervoid SROA::CanonicalizeAllocaUsers(AllocationInst *AI) { 815d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // At this point, we know that the end result will be SROA'd and promoted, so 816d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // we can insert ugly code if required so long as sroa+mem2reg will clean it 817d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // up. 818d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner for (Value::use_iterator UI = AI->use_begin(), E = AI->use_end(); 819d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner UI != E; ) { 820a9d1a843fc74a9d877e105744e710496863f7580Chris Lattner GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(*UI++); 821a9d1a843fc74a9d877e105744e710496863f7580Chris Lattner if (!GEPI) continue; 82296326f9d312585532c95dcc31626f45f16cd5dd8Reid Spencer gep_type_iterator I = gep_type_begin(GEPI); 823d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner ++I; 824d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner 825d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner if (const ArrayType *AT = dyn_cast<ArrayType>(*I)) { 826d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner uint64_t NumElements = AT->getNumElements(); 827fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 828d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner if (!isa<ConstantInt>(I.getOperand())) { 829d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner if (NumElements == 1) { 830c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer GEPI->setOperand(2, Constant::getNullValue(Type::Int32Ty)); 831d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } else { 832d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner assert(NumElements == 2 && "Unhandled case!"); 833d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // All users of the GEP must be loads. At each use of the GEP, insert 834d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // two loads of the appropriate indexed GEP and select between them. 835e4d87aa2de6e52952dca73716386db09aad5a8fdReid Spencer Value *IsOne = new ICmpInst(ICmpInst::ICMP_NE, I.getOperand(), 836d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner Constant::getNullValue(I.getOperand()->getType()), 837e4d87aa2de6e52952dca73716386db09aad5a8fdReid Spencer "isone", GEPI); 838d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // Insert the new GEP instructions, which are properly indexed. 8391ccd185cb49d81465a2901622e58ceae046d1d83Chris Lattner SmallVector<Value*, 8> Indices(GEPI->op_begin()+1, GEPI->op_end()); 840c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer Indices[1] = Constant::getNullValue(Type::Int32Ty); 8411ccd185cb49d81465a2901622e58ceae046d1d83Chris Lattner Value *ZeroIdx = new GetElementPtrInst(GEPI->getOperand(0), 842b8f74793b9d161bc666fe27fc92fe112b6ec169bDavid Greene Indices.begin(), 843b8f74793b9d161bc666fe27fc92fe112b6ec169bDavid Greene Indices.end(), 844d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner GEPI->getName()+".0", GEPI); 845c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer Indices[1] = ConstantInt::get(Type::Int32Ty, 1); 8461ccd185cb49d81465a2901622e58ceae046d1d83Chris Lattner Value *OneIdx = new GetElementPtrInst(GEPI->getOperand(0), 847b8f74793b9d161bc666fe27fc92fe112b6ec169bDavid Greene Indices.begin(), 848b8f74793b9d161bc666fe27fc92fe112b6ec169bDavid Greene Indices.end(), 849d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner GEPI->getName()+".1", GEPI); 850d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // Replace all loads of the variable index GEP with loads from both 851d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner // indexes and a select. 852d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner while (!GEPI->use_empty()) { 853d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner LoadInst *LI = cast<LoadInst>(GEPI->use_back()); 854d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner Value *Zero = new LoadInst(ZeroIdx, LI->getName()+".0", LI); 855d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner Value *One = new LoadInst(OneIdx , LI->getName()+".1", LI); 856d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner Value *R = new SelectInst(IsOne, One, Zero, LI->getName(), LI); 857d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner LI->replaceAllUsesWith(R); 858d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner LI->eraseFromParent(); 859d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } 860d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner GEPI->eraseFromParent(); 861d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } 862d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } 863d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } 864d878ecd904e4469344a2274f9784422c2c68b81cChris Lattner } 8655e062a1eda2c4adffd428a35e737a431fc37f4e0Chris Lattner} 866a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 867a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// MergeInType - Add the 'In' type to the accumulated type so far. If the 868a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// types are incompatible, return true, otherwise update Accum and return 869a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// false. 870de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// 871d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// There are three cases we handle here: 872d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// 1) An effectively-integer union, where the pieces are stored into as 873de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// smaller integers (common with byte swap and other idioms). 874d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// 2) A union of vector types of the same size and potentially its elements. 875d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// Here we turn element accesses into insert/extract element operations. 876d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// 3) A union of scalar types, such as int/float or int/pointer. Here we 877d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// merge together into integers, allowing the xform to work with #1 as 878d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner/// well. 8795b121cc688eacf41b1b773244882d206199dc105Chris Lattnerstatic bool MergeInType(const Type *In, const Type *&Accum, 8805b121cc688eacf41b1b773244882d206199dc105Chris Lattner const TargetData &TD) { 881a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // If this is our first type, just use it. 8829d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer const VectorType *PTy; 883de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner if (Accum == Type::VoidTy || In == Accum) { 884a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner Accum = In; 885d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner } else if (In == Type::VoidTy) { 886d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // Noop. 88742a75517250017a52afb03a0ade03cbd49559fe5Chris Lattner } else if (In->isInteger() && Accum->isInteger()) { // integer union. 888a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // Otherwise pick whichever type is larger. 889a54b7cbd452b3adb2f51346140d996b29c2cdb30Reid Spencer if (cast<IntegerType>(In)->getBitWidth() > 890a54b7cbd452b3adb2f51346140d996b29c2cdb30Reid Spencer cast<IntegerType>(Accum)->getBitWidth()) 891a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner Accum = In; 8925b121cc688eacf41b1b773244882d206199dc105Chris Lattner } else if (isa<PointerType>(In) && isa<PointerType>(Accum)) { 893c836333c3b0a18c398436ae00667a8fb5e476129Chris Lattner // Pointer unions just stay as one of the pointers. 8949d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer } else if (isa<VectorType>(In) || isa<VectorType>(Accum)) { 8959d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer if ((PTy = dyn_cast<VectorType>(Accum)) && 896d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner PTy->getElementType() == In) { 897d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // Accum is a vector, and we are accessing an element: ok. 8989d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer } else if ((PTy = dyn_cast<VectorType>(In)) && 899d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner PTy->getElementType() == Accum) { 900d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // In is a vector, and accum is an element: ok, remember In. 901d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner Accum = In; 9029d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer } else if ((PTy = dyn_cast<VectorType>(In)) && isa<VectorType>(Accum) && 9039d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer PTy->getBitWidth() == cast<VectorType>(Accum)->getBitWidth()) { 904d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // Two vectors of the same size: keep Accum. 905d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner } else { 906d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // Cannot insert an short into a <4 x int> or handle 907d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // <2 x int> -> <4 x int> 908d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner return true; 909d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner } 91021c362d3240d0ba9ff98b7f36e54f25936d1a201Chris Lattner } else { 911d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner // Pointer/FP/Integer unions merge together as integers. 912d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner switch (Accum->getTypeID()) { 913d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner case Type::PointerTyID: Accum = TD.getIntPtrType(); break; 914c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer case Type::FloatTyID: Accum = Type::Int32Ty; break; 915c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer case Type::DoubleTyID: Accum = Type::Int64Ty; break; 916ef0ab932ef3b07016ffb827cd529d4787d7ed12eDale Johannesen case Type::X86_FP80TyID: return true; 917ef0ab932ef3b07016ffb827cd529d4787d7ed12eDale Johannesen case Type::FP128TyID: return true; 918ef0ab932ef3b07016ffb827cd529d4787d7ed12eDale Johannesen case Type::PPC_FP128TyID: return true; 919d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner default: 92042a75517250017a52afb03a0ade03cbd49559fe5Chris Lattner assert(Accum->isInteger() && "Unknown FP type!"); 921d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner break; 922d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner } 923d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner 924d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner switch (In->getTypeID()) { 925d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner case Type::PointerTyID: In = TD.getIntPtrType(); break; 926c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer case Type::FloatTyID: In = Type::Int32Ty; break; 927c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer case Type::DoubleTyID: In = Type::Int64Ty; break; 928ef0ab932ef3b07016ffb827cd529d4787d7ed12eDale Johannesen case Type::X86_FP80TyID: return true; 929ef0ab932ef3b07016ffb827cd529d4787d7ed12eDale Johannesen case Type::FP128TyID: return true; 930ef0ab932ef3b07016ffb827cd529d4787d7ed12eDale Johannesen case Type::PPC_FP128TyID: return true; 931d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner default: 93242a75517250017a52afb03a0ade03cbd49559fe5Chris Lattner assert(In->isInteger() && "Unknown FP type!"); 933d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner break; 934d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner } 935d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner return MergeInType(In, Accum, TD); 936a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 937a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return false; 938a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner} 939a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 9403cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands/// getUIntAtLeastAsBigAs - Return an unsigned integer type that is at least 941a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// as big as the specified type. If there is no suitable type, this returns 942a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// null. 9433cb3650a278e37aa6378127c51e407d2823139b4Duncan Sandsconst Type *getUIntAtLeastAsBigAs(unsigned NumBits) { 944a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (NumBits > 64) return 0; 945c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer if (NumBits > 32) return Type::Int64Ty; 946c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer if (NumBits > 16) return Type::Int32Ty; 947c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer if (NumBits > 8) return Type::Int16Ty; 948c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer return Type::Int8Ty; 949a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner} 950a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 951a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// CanConvertToScalar - V is a pointer. If we can convert the pointee to a 952a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// single scalar integer type, return that type. Further, if the use is not 953a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// a completely trivial use that mem2reg could promote, set IsNotTrivial. If 954a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// there are no uses of this pointer, return Type::VoidTy to differentiate from 955a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// failure. 956a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// 957a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattnerconst Type *SROA::CanConvertToScalar(Value *V, bool &IsNotTrivial) { 958a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *UsedType = Type::VoidTy; // No uses, no forced type. 959a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const TargetData &TD = getAnalysis<TargetData>(); 960a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const PointerType *PTy = cast<PointerType>(V->getType()); 961a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 962a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI!=E; ++UI) { 963a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner Instruction *User = cast<Instruction>(*UI); 964a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 965a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(User)) { 9665b121cc688eacf41b1b773244882d206199dc105Chris Lattner if (MergeInType(LI->getType(), UsedType, TD)) 967a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return 0; 968a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 969a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else if (StoreInst *SI = dyn_cast<StoreInst>(User)) { 97024d6da5fedcf39891f7d8c5b031c01324b3db545Reid Spencer // Storing the pointer, not into the value? 971a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (SI->getOperand(0) == V) return 0; 972a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 973de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner // NOTE: We could handle storing of FP imms into integers here! 974a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 9755b121cc688eacf41b1b773244882d206199dc105Chris Lattner if (MergeInType(SI->getOperand(0)->getType(), UsedType, TD)) 976a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return 0; 977d22dbdf60652536d44dc4a380059368bea75b5cdChris Lattner } else if (BitCastInst *CI = dyn_cast<BitCastInst>(User)) { 978a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner IsNotTrivial = true; 979a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *SubTy = CanConvertToScalar(CI, IsNotTrivial); 9805b121cc688eacf41b1b773244882d206199dc105Chris Lattner if (!SubTy || MergeInType(SubTy, UsedType, TD)) return 0; 981a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(User)) { 982a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // Check to see if this is stepping over an element: GEP Ptr, int C 983a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (GEP->getNumOperands() == 2 && isa<ConstantInt>(GEP->getOperand(1))) { 984b83eb6447ba155342598f0fabe1f08f5baa9164aReid Spencer unsigned Idx = cast<ConstantInt>(GEP->getOperand(1))->getZExtValue(); 9853cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands unsigned ElSize = TD.getABITypeSize(PTy->getElementType()); 986a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner unsigned BitOffset = Idx*ElSize*8; 987a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (BitOffset > 64 || !isPowerOf2_32(ElSize)) return 0; 988a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 989a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner IsNotTrivial = true; 990a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *SubElt = CanConvertToScalar(GEP, IsNotTrivial); 991a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (SubElt == 0) return 0; 99242a75517250017a52afb03a0ade03cbd49559fe5Chris Lattner if (SubElt != Type::VoidTy && SubElt->isInteger()) { 993a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *NewTy = 9943cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands getUIntAtLeastAsBigAs(TD.getABITypeSizeInBits(SubElt)+BitOffset); 9955b121cc688eacf41b1b773244882d206199dc105Chris Lattner if (NewTy == 0 || MergeInType(NewTy, UsedType, TD)) return 0; 996a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner continue; 997a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 998a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else if (GEP->getNumOperands() == 3 && 999a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner isa<ConstantInt>(GEP->getOperand(1)) && 1000a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner isa<ConstantInt>(GEP->getOperand(2)) && 1001843f0767acd05baed952d39e77ea89b438430a4fZhou Sheng cast<ConstantInt>(GEP->getOperand(1))->isZero()) { 1002a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // We are stepping into an element, e.g. a structure or an array: 1003a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // GEP Ptr, int 0, uint C 1004a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *AggTy = PTy->getElementType(); 1005b83eb6447ba155342598f0fabe1f08f5baa9164aReid Spencer unsigned Idx = cast<ConstantInt>(GEP->getOperand(2))->getZExtValue(); 1006a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1007a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (const ArrayType *ATy = dyn_cast<ArrayType>(AggTy)) { 1008a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (Idx >= ATy->getNumElements()) return 0; // Out of range. 1009ac9dcb94dde5f166ee29372385c0e3b695227ab4Reid Spencer } else if (const VectorType *VectorTy = dyn_cast<VectorType>(AggTy)) { 101007a96765daedf180a7102d39fe56c499878312b7Dan Gohman // Getting an element of the vector. 1011ac9dcb94dde5f166ee29372385c0e3b695227ab4Reid Spencer if (Idx >= VectorTy->getNumElements()) return 0; // Out of range. 1012de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner 1013ac9dcb94dde5f166ee29372385c0e3b695227ab4Reid Spencer // Merge in the vector type. 1014ac9dcb94dde5f166ee29372385c0e3b695227ab4Reid Spencer if (MergeInType(VectorTy, UsedType, TD)) return 0; 1015de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner 1016de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner const Type *SubTy = CanConvertToScalar(GEP, IsNotTrivial); 1017de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner if (SubTy == 0) return 0; 1018de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner 10195b121cc688eacf41b1b773244882d206199dc105Chris Lattner if (SubTy != Type::VoidTy && MergeInType(SubTy, UsedType, TD)) 1020de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner return 0; 1021de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner 1022de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner // We'll need to change this to an insert/extract element operation. 1023de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner IsNotTrivial = true; 1024de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner continue; // Everything looks ok 1025de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner 1026a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else if (isa<StructType>(AggTy)) { 1027a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // Structs are always ok. 1028a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else { 1029a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return 0; 1030a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 10313cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands const Type *NTy = getUIntAtLeastAsBigAs(TD.getABITypeSizeInBits(AggTy)); 10325b121cc688eacf41b1b773244882d206199dc105Chris Lattner if (NTy == 0 || MergeInType(NTy, UsedType, TD)) return 0; 1033a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *SubTy = CanConvertToScalar(GEP, IsNotTrivial); 1034a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (SubTy == 0) return 0; 10355b121cc688eacf41b1b773244882d206199dc105Chris Lattner if (SubTy != Type::VoidTy && MergeInType(SubTy, UsedType, TD)) 1036a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return 0; 1037a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner continue; // Everything looks ok 1038a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1039a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return 0; 1040a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else { 1041a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // Cannot handle this! 1042a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return 0; 1043a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1044a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1045a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1046a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner return UsedType; 1047a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner} 1048a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1049a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// ConvertToScalar - The specified alloca passes the CanConvertToScalar 1050a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// predicate and is non-trivial. Convert it to something that can be trivially 1051a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// promoted into a register by mem2reg. 1052a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattnervoid SROA::ConvertToScalar(AllocationInst *AI, const Type *ActualTy) { 1053b7427031372337e6d67f9573ec6c722ab5ea913eBill Wendling DOUT << "CONVERT TO SCALAR: " << *AI << " TYPE = " 1054b7427031372337e6d67f9573ec6c722ab5ea913eBill Wendling << *ActualTy << "\n"; 1055a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner ++NumConverted; 1056a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1057a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner BasicBlock *EntryBlock = AI->getParent(); 1058ecb7a77885b174cf4d001a9b48533b3979e7810dDan Gohman assert(EntryBlock == &EntryBlock->getParent()->getEntryBlock() && 1059a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner "Not in the entry block!"); 1060a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner EntryBlock->getInstList().remove(AI); // Take the alloca out of the program. 1061a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1062a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // Create and insert the alloca. 1063de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner AllocaInst *NewAI = new AllocaInst(ActualTy, 0, AI->getName(), 1064de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner EntryBlock->begin()); 1065a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner ConvertUsesToScalar(AI, NewAI, 0); 1066a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner delete AI; 1067a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner} 1068a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1069a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1070a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner/// ConvertUsesToScalar - Convert all of the users of Ptr to use the new alloca 1071de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// directly. This happens when we are converting an "integer union" to a 1072de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// single integer scalar, or when we are converting a "vector union" to a 1073de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// vector with insert/extractelement instructions. 1074de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// 1075de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// Offset is an offset from the original alloca, in bits that need to be 1076de6df88529e20541dcfab7824af2eb0776194f01Chris Lattner/// shifted to the right. By the end of this, there should be no uses of Ptr. 1077a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattnervoid SROA::ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI, unsigned Offset) { 1078a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner while (!Ptr->use_empty()) { 1079a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner Instruction *User = cast<Instruction>(Ptr->use_back()); 1080a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1081a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(User)) { 1082800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *NV = ConvertUsesOfLoadToScalar(LI, NewAI, Offset); 1083a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner LI->replaceAllUsesWith(NV); 1084a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner LI->eraseFromParent(); 1085a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else if (StoreInst *SI = dyn_cast<StoreInst>(User)) { 1086a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner assert(SI->getOperand(0) != Ptr && "Consistency error!"); 1087a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1088800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *SV = ConvertUsesOfStoreToScalar(SI, NewAI, Offset); 1089a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner new StoreInst(SV, NewAI, SI); 1090a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner SI->eraseFromParent(); 1091a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1092f4b1818728fb5cb0740cf5362faf72dd66ccf3eaChris Lattner } else if (BitCastInst *CI = dyn_cast<BitCastInst>(User)) { 1093b10e0da065fc2c18b5bee9011eb249e223a23108Chris Lattner ConvertUsesToScalar(CI, NewAI, Offset); 1094a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner CI->eraseFromParent(); 1095a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(User)) { 1096a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const PointerType *AggPtrTy = 1097a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner cast<PointerType>(GEP->getOperand(0)->getType()); 1098a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const TargetData &TD = getAnalysis<TargetData>(); 10993cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands unsigned AggSizeInBits = 11003cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands TD.getABITypeSizeInBits(AggPtrTy->getElementType()); 11013cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands 1102a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // Check to see if this is stepping over an element: GEP Ptr, int C 1103a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner unsigned NewOffset = Offset; 1104a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (GEP->getNumOperands() == 2) { 1105b83eb6447ba155342598f0fabe1f08f5baa9164aReid Spencer unsigned Idx = cast<ConstantInt>(GEP->getOperand(1))->getZExtValue(); 1106a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner unsigned BitOffset = Idx*AggSizeInBits; 1107a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1108f4b1818728fb5cb0740cf5362faf72dd66ccf3eaChris Lattner NewOffset += BitOffset; 1109a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else if (GEP->getNumOperands() == 3) { 1110a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner // We know that operand #2 is zero. 1111b83eb6447ba155342598f0fabe1f08f5baa9164aReid Spencer unsigned Idx = cast<ConstantInt>(GEP->getOperand(2))->getZExtValue(); 1112a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner const Type *AggTy = AggPtrTy->getElementType(); 1113a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner if (const SequentialType *SeqTy = dyn_cast<SequentialType>(AggTy)) { 11143cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands unsigned ElSizeBits = 11153cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands TD.getABITypeSizeInBits(SeqTy->getElementType()); 1116a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1117f4b1818728fb5cb0740cf5362faf72dd66ccf3eaChris Lattner NewOffset += ElSizeBits*Idx; 1118a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else if (const StructType *STy = dyn_cast<StructType>(AggTy)) { 1119b1919e2f08ecb37140af676fd2916f8d5ed7df3dChris Lattner unsigned EltBitOffset = 11203cb3650a278e37aa6378127c51e407d2823139b4Duncan Sands TD.getStructLayout(STy)->getElementOffsetInBits(Idx); 1121a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner 1122f4b1818728fb5cb0740cf5362faf72dd66ccf3eaChris Lattner NewOffset += EltBitOffset; 1123a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else { 1124a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner assert(0 && "Unsupported operation!"); 1125a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner abort(); 1126a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1127a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else { 1128a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner assert(0 && "Unsupported operation!"); 1129a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner abort(); 1130a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1131a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner ConvertUsesToScalar(GEP, NewAI, NewOffset); 1132a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner GEP->eraseFromParent(); 1133a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } else { 1134a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner assert(0 && "Unsupported operation!"); 1135a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner abort(); 1136a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1137a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner } 1138a188894d67a3cc2516b25aae9b3cbdbff4b0babeChris Lattner} 113979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 1140800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// ConvertUsesOfLoadToScalar - Convert all of the users the specified load to 1141800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// use the new alloca directly, returning the value that should replace the 1142800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// load. This happens when we are converting an "integer union" to a 1143800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// single integer scalar, or when we are converting a "vector union" to a 1144800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// vector with insert/extractelement instructions. 1145800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// 1146800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// Offset is an offset from the original alloca, in bits that need to be 1147800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// shifted to the right. By the end of this, there should be no uses of Ptr. 1148800de31776356910eb877e71df9f32b0a6215324Chris LattnerValue *SROA::ConvertUsesOfLoadToScalar(LoadInst *LI, AllocaInst *NewAI, 1149800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned Offset) { 1150800de31776356910eb877e71df9f32b0a6215324Chris Lattner // The load is a bit extract from NewAI shifted right by Offset bits. 1151800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *NV = new LoadInst(NewAI, LI->getName(), LI); 1152800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1153800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (NV->getType() == LI->getType() && Offset == 0) { 1154800de31776356910eb877e71df9f32b0a6215324Chris Lattner // We win, no conversion needed. 1155800de31776356910eb877e71df9f32b0a6215324Chris Lattner return NV; 1156800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 1157800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1158800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (const VectorType *PTy = dyn_cast<VectorType>(NV->getType())) { 1159800de31776356910eb877e71df9f32b0a6215324Chris Lattner // If the result alloca is a vector type, this is either an element 1160800de31776356910eb877e71df9f32b0a6215324Chris Lattner // access or a bitcast to another vector type. 1161800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (isa<VectorType>(LI->getType())) { 1162800de31776356910eb877e71df9f32b0a6215324Chris Lattner NV = new BitCastInst(NV, LI->getType(), LI->getName(), LI); 1163800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else { 1164800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Must be an element access. 1165800de31776356910eb877e71df9f32b0a6215324Chris Lattner const TargetData &TD = getAnalysis<TargetData>(); 1166800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned Elt = Offset/TD.getABITypeSizeInBits(PTy->getElementType()); 1167800de31776356910eb877e71df9f32b0a6215324Chris Lattner NV = new ExtractElementInst(NV, ConstantInt::get(Type::Int32Ty, Elt), 1168800de31776356910eb877e71df9f32b0a6215324Chris Lattner "tmp", LI); 1169800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 1170800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else if (isa<PointerType>(NV->getType())) { 1171800de31776356910eb877e71df9f32b0a6215324Chris Lattner assert(isa<PointerType>(LI->getType())); 1172800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Must be ptr->ptr cast. Anything else would result in NV being 1173800de31776356910eb877e71df9f32b0a6215324Chris Lattner // an integer. 1174800de31776356910eb877e71df9f32b0a6215324Chris Lattner NV = new BitCastInst(NV, LI->getType(), LI->getName(), LI); 1175800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else { 1176800de31776356910eb877e71df9f32b0a6215324Chris Lattner const IntegerType *NTy = cast<IntegerType>(NV->getType()); 1177800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1178800de31776356910eb877e71df9f32b0a6215324Chris Lattner // If this is a big-endian system and the load is narrower than the 1179800de31776356910eb877e71df9f32b0a6215324Chris Lattner // full alloca type, we need to do a shift to get the right bits. 1180800de31776356910eb877e71df9f32b0a6215324Chris Lattner int ShAmt = 0; 1181800de31776356910eb877e71df9f32b0a6215324Chris Lattner const TargetData &TD = getAnalysis<TargetData>(); 1182800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (TD.isBigEndian()) { 1183800de31776356910eb877e71df9f32b0a6215324Chris Lattner // On big-endian machines, the lowest bit is stored at the bit offset 1184800de31776356910eb877e71df9f32b0a6215324Chris Lattner // from the pointer given by getTypeStoreSizeInBits. This matters for 1185800de31776356910eb877e71df9f32b0a6215324Chris Lattner // integers with a bitwidth that is not a multiple of 8. 1186800de31776356910eb877e71df9f32b0a6215324Chris Lattner ShAmt = TD.getTypeStoreSizeInBits(NTy) - 1187800de31776356910eb877e71df9f32b0a6215324Chris Lattner TD.getTypeStoreSizeInBits(LI->getType()) - Offset; 1188800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else { 1189800de31776356910eb877e71df9f32b0a6215324Chris Lattner ShAmt = Offset; 1190800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 1191800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1192800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Note: we support negative bitwidths (with shl) which are not defined. 1193800de31776356910eb877e71df9f32b0a6215324Chris Lattner // We do this to support (f.e.) loads off the end of a structure where 1194800de31776356910eb877e71df9f32b0a6215324Chris Lattner // only some bits are used. 1195800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (ShAmt > 0 && (unsigned)ShAmt < NTy->getBitWidth()) 1196800de31776356910eb877e71df9f32b0a6215324Chris Lattner NV = BinaryOperator::createLShr(NV, 1197800de31776356910eb877e71df9f32b0a6215324Chris Lattner ConstantInt::get(NV->getType(),ShAmt), 1198800de31776356910eb877e71df9f32b0a6215324Chris Lattner LI->getName(), LI); 1199800de31776356910eb877e71df9f32b0a6215324Chris Lattner else if (ShAmt < 0 && (unsigned)-ShAmt < NTy->getBitWidth()) 1200800de31776356910eb877e71df9f32b0a6215324Chris Lattner NV = BinaryOperator::createShl(NV, 1201800de31776356910eb877e71df9f32b0a6215324Chris Lattner ConstantInt::get(NV->getType(),-ShAmt), 1202800de31776356910eb877e71df9f32b0a6215324Chris Lattner LI->getName(), LI); 1203800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1204800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Finally, unconditionally truncate the integer to the right width. 1205800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned LIBitWidth = TD.getTypeSizeInBits(LI->getType()); 1206800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (LIBitWidth < NTy->getBitWidth()) 1207800de31776356910eb877e71df9f32b0a6215324Chris Lattner NV = new TruncInst(NV, IntegerType::get(LIBitWidth), 1208800de31776356910eb877e71df9f32b0a6215324Chris Lattner LI->getName(), LI); 1209800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1210800de31776356910eb877e71df9f32b0a6215324Chris Lattner // If the result is an integer, this is a trunc or bitcast. 1211800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (isa<IntegerType>(LI->getType())) { 1212800de31776356910eb877e71df9f32b0a6215324Chris Lattner assert(NV->getType() == LI->getType() && "Truncate wasn't enough?"); 1213800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else if (LI->getType()->isFloatingPoint()) { 1214800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Just do a bitcast, we know the sizes match up. 1215800de31776356910eb877e71df9f32b0a6215324Chris Lattner NV = new BitCastInst(NV, LI->getType(), LI->getName(), LI); 1216800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else { 1217800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Otherwise must be a pointer. 1218800de31776356910eb877e71df9f32b0a6215324Chris Lattner NV = new IntToPtrInst(NV, LI->getType(), LI->getName(), LI); 1219800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 1220800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 1221800de31776356910eb877e71df9f32b0a6215324Chris Lattner return NV; 1222800de31776356910eb877e71df9f32b0a6215324Chris Lattner} 1223800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1224800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1225800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// ConvertUsesOfStoreToScalar - Convert the specified store to a load+store 1226800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// pair of the new alloca directly, returning the value that should be stored 1227800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// to the alloca. This happens when we are converting an "integer union" to a 1228800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// single integer scalar, or when we are converting a "vector union" to a 1229800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// vector with insert/extractelement instructions. 1230800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// 1231800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// Offset is an offset from the original alloca, in bits that need to be 1232800de31776356910eb877e71df9f32b0a6215324Chris Lattner/// shifted to the right. By the end of this, there should be no uses of Ptr. 1233800de31776356910eb877e71df9f32b0a6215324Chris LattnerValue *SROA::ConvertUsesOfStoreToScalar(StoreInst *SI, AllocaInst *NewAI, 1234800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned Offset) { 1235800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1236800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Convert the stored type to the actual type, shift it left to insert 1237800de31776356910eb877e71df9f32b0a6215324Chris Lattner // then 'or' into place. 1238800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *SV = SI->getOperand(0); 1239800de31776356910eb877e71df9f32b0a6215324Chris Lattner const Type *AllocaType = NewAI->getType()->getElementType(); 1240800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (SV->getType() == AllocaType && Offset == 0) { 1241800de31776356910eb877e71df9f32b0a6215324Chris Lattner // All is well. 1242800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else if (const VectorType *PTy = dyn_cast<VectorType>(AllocaType)) { 1243800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *Old = new LoadInst(NewAI, NewAI->getName()+".in", SI); 1244800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1245800de31776356910eb877e71df9f32b0a6215324Chris Lattner // If the result alloca is a vector type, this is either an element 1246800de31776356910eb877e71df9f32b0a6215324Chris Lattner // access or a bitcast to another vector type. 1247800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (isa<VectorType>(SV->getType())) { 1248800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV = new BitCastInst(SV, AllocaType, SV->getName(), SI); 1249800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else { 1250800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Must be an element insertion. 1251800de31776356910eb877e71df9f32b0a6215324Chris Lattner const TargetData &TD = getAnalysis<TargetData>(); 1252800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned Elt = Offset/TD.getABITypeSizeInBits(PTy->getElementType()); 1253800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV = new InsertElementInst(Old, SV, 1254800de31776356910eb877e71df9f32b0a6215324Chris Lattner ConstantInt::get(Type::Int32Ty, Elt), 1255800de31776356910eb877e71df9f32b0a6215324Chris Lattner "tmp", SI); 1256800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 1257800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else if (isa<PointerType>(AllocaType)) { 1258800de31776356910eb877e71df9f32b0a6215324Chris Lattner // If the alloca type is a pointer, then all the elements must be 1259800de31776356910eb877e71df9f32b0a6215324Chris Lattner // pointers. 1260800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (SV->getType() != AllocaType) 1261800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV = new BitCastInst(SV, AllocaType, SV->getName(), SI); 1262800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else { 1263800de31776356910eb877e71df9f32b0a6215324Chris Lattner Value *Old = new LoadInst(NewAI, NewAI->getName()+".in", SI); 1264800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1265800de31776356910eb877e71df9f32b0a6215324Chris Lattner // If SV is a float, convert it to the appropriate integer type. 1266800de31776356910eb877e71df9f32b0a6215324Chris Lattner // If it is a pointer, do the same, and also handle ptr->ptr casts 1267800de31776356910eb877e71df9f32b0a6215324Chris Lattner // here. 1268800de31776356910eb877e71df9f32b0a6215324Chris Lattner const TargetData &TD = getAnalysis<TargetData>(); 1269800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned SrcWidth = TD.getTypeSizeInBits(SV->getType()); 1270800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned DestWidth = TD.getTypeSizeInBits(AllocaType); 1271800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned SrcStoreWidth = TD.getTypeStoreSizeInBits(SV->getType()); 1272800de31776356910eb877e71df9f32b0a6215324Chris Lattner unsigned DestStoreWidth = TD.getTypeStoreSizeInBits(AllocaType); 1273800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (SV->getType()->isFloatingPoint()) 1274800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV = new BitCastInst(SV, IntegerType::get(SrcWidth), 1275800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV->getName(), SI); 1276800de31776356910eb877e71df9f32b0a6215324Chris Lattner else if (isa<PointerType>(SV->getType())) 1277800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV = new PtrToIntInst(SV, TD.getIntPtrType(), SV->getName(), SI); 1278800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1279800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Always zero extend the value if needed. 1280800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (SV->getType() != AllocaType) 1281800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV = new ZExtInst(SV, AllocaType, SV->getName(), SI); 1282800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1283800de31776356910eb877e71df9f32b0a6215324Chris Lattner // If this is a big-endian system and the store is narrower than the 1284800de31776356910eb877e71df9f32b0a6215324Chris Lattner // full alloca type, we need to do a shift to get the right bits. 1285800de31776356910eb877e71df9f32b0a6215324Chris Lattner int ShAmt = 0; 1286800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (TD.isBigEndian()) { 1287800de31776356910eb877e71df9f32b0a6215324Chris Lattner // On big-endian machines, the lowest bit is stored at the bit offset 1288800de31776356910eb877e71df9f32b0a6215324Chris Lattner // from the pointer given by getTypeStoreSizeInBits. This matters for 1289800de31776356910eb877e71df9f32b0a6215324Chris Lattner // integers with a bitwidth that is not a multiple of 8. 1290800de31776356910eb877e71df9f32b0a6215324Chris Lattner ShAmt = DestStoreWidth - SrcStoreWidth - Offset; 1291800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else { 1292800de31776356910eb877e71df9f32b0a6215324Chris Lattner ShAmt = Offset; 1293800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 1294800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1295800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Note: we support negative bitwidths (with shr) which are not defined. 1296800de31776356910eb877e71df9f32b0a6215324Chris Lattner // We do this to support (f.e.) stores off the end of a structure where 1297800de31776356910eb877e71df9f32b0a6215324Chris Lattner // only some bits in the structure are set. 1298800de31776356910eb877e71df9f32b0a6215324Chris Lattner APInt Mask(APInt::getLowBitsSet(DestWidth, SrcWidth)); 1299800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (ShAmt > 0 && (unsigned)ShAmt < DestWidth) { 1300800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV = BinaryOperator::createShl(SV, 1301800de31776356910eb877e71df9f32b0a6215324Chris Lattner ConstantInt::get(SV->getType(), ShAmt), 1302800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV->getName(), SI); 1303800de31776356910eb877e71df9f32b0a6215324Chris Lattner Mask <<= ShAmt; 1304800de31776356910eb877e71df9f32b0a6215324Chris Lattner } else if (ShAmt < 0 && (unsigned)-ShAmt < DestWidth) { 1305800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV = BinaryOperator::createLShr(SV, 1306800de31776356910eb877e71df9f32b0a6215324Chris Lattner ConstantInt::get(SV->getType(),-ShAmt), 1307800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV->getName(), SI); 1308800de31776356910eb877e71df9f32b0a6215324Chris Lattner Mask = Mask.lshr(ShAmt); 1309800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 1310800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1311800de31776356910eb877e71df9f32b0a6215324Chris Lattner // Mask out the bits we are about to insert from the old value, and or 1312800de31776356910eb877e71df9f32b0a6215324Chris Lattner // in the new bits. 1313800de31776356910eb877e71df9f32b0a6215324Chris Lattner if (SrcWidth != DestWidth) { 1314800de31776356910eb877e71df9f32b0a6215324Chris Lattner assert(DestWidth > SrcWidth); 1315800de31776356910eb877e71df9f32b0a6215324Chris Lattner Old = BinaryOperator::createAnd(Old, ConstantInt::get(~Mask), 1316800de31776356910eb877e71df9f32b0a6215324Chris Lattner Old->getName()+".mask", SI); 1317800de31776356910eb877e71df9f32b0a6215324Chris Lattner SV = BinaryOperator::createOr(Old, SV, SV->getName()+".ins", SI); 1318800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 1319800de31776356910eb877e71df9f32b0a6215324Chris Lattner } 1320800de31776356910eb877e71df9f32b0a6215324Chris Lattner return SV; 1321800de31776356910eb877e71df9f32b0a6215324Chris Lattner} 1322800de31776356910eb877e71df9f32b0a6215324Chris Lattner 1323800de31776356910eb877e71df9f32b0a6215324Chris Lattner 132479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 132579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// PointsToConstantGlobal - Return true if V (possibly indirectly) points to 132679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// some part of a constant global variable. This intentionally only accepts 132779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// constant expressions because we don't can't rewrite arbitrary instructions. 132879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattnerstatic bool PointsToConstantGlobal(Value *V) { 132979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) 133079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return GV->isConstant(); 133179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) 133279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (CE->getOpcode() == Instruction::BitCast || 133379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner CE->getOpcode() == Instruction::GetElementPtr) 133479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return PointsToConstantGlobal(CE->getOperand(0)); 133579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return false; 133679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner} 133779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 133879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// isOnlyCopiedFromConstantGlobal - Recursively walk the uses of a (derived) 133979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// pointer to an alloca. Ignore any reads of the pointer, return false if we 134079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// see any stores or other unknown uses. If we see pointer arithmetic, keep 134179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// track of whether it moves the pointer (with isOffset) but otherwise traverse 134279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// the uses. If we see a memcpy/memmove that targets an unoffseted pointer to 134379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// the alloca, and if the source pointer is a pointer to a constant global, we 134479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// can optimize this. 134579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattnerstatic bool isOnlyCopiedFromConstantGlobal(Value *V, Instruction *&TheCopy, 134679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner bool isOffset) { 134779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI!=E; ++UI) { 134879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (isa<LoadInst>(*UI)) { 134979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // Ignore loads, they are always ok. 135079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner continue; 135179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner } 135279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (BitCastInst *BCI = dyn_cast<BitCastInst>(*UI)) { 135379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If uses of the bitcast are ok, we are ok. 135479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (!isOnlyCopiedFromConstantGlobal(BCI, TheCopy, isOffset)) 135579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return false; 135679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner continue; 135779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner } 135879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(*UI)) { 135979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If the GEP has all zero indices, it doesn't offset the pointer. If it 136079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // doesn't, it does. 136179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (!isOnlyCopiedFromConstantGlobal(GEP, TheCopy, 136279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner isOffset || !GEP->hasAllZeroIndices())) 136379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return false; 136479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner continue; 136579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner } 136679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 136779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If this is isn't our memcpy/memmove, reject it as something we can't 136879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // handle. 136979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (!isa<MemCpyInst>(*UI) && !isa<MemMoveInst>(*UI)) 137079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return false; 137179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 137279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If we already have seen a copy, reject the second one. 137379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (TheCopy) return false; 137479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 137579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If the pointer has been offset from the start of the alloca, we can't 137679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // safely handle this. 137779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (isOffset) return false; 137879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 137979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If the memintrinsic isn't using the alloca as the dest, reject it. 138079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (UI.getOperandNo() != 1) return false; 138179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 138279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner MemIntrinsic *MI = cast<MemIntrinsic>(*UI); 138379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 138479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // If the source of the memcpy/move is not a constant global, reject it. 138579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (!PointsToConstantGlobal(MI->getOperand(2))) 138679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return false; 138779b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 138879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner // Otherwise, the transform is safe. Remember the copy instruction. 138979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner TheCopy = MI; 139079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner } 139179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return true; 139279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner} 139379b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner 139479b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// isOnlyCopiedFromConstantGlobal - Return true if the specified alloca is only 139579b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// modified by a copy from a constant global. If we can prove this, we can 139679b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner/// replace any uses of the alloca with uses of the global directly. 139779b3bd395dc3303cde65e18e0524ed2f70268c99Chris LattnerInstruction *SROA::isOnlyCopiedFromConstantGlobal(AllocationInst *AI) { 139879b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner Instruction *TheCopy = 0; 139979b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner if (::isOnlyCopiedFromConstantGlobal(AI, TheCopy, false)) 140079b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return TheCopy; 140179b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner return 0; 140279b3bd395dc3303cde65e18e0524ed2f70268c99Chris Lattner} 1403