ScalarReplAggregates.cpp revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f
19085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org//===- ScalarReplAggregates.cpp - Scalar Replacement of Aggregates --------===// 29085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org// 39085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org// The LLVM Compiler Infrastructure 45ec4892aef9cca42940d7d92302abf674365f6b7ager@chromium.org// 55ec4892aef9cca42940d7d92302abf674365f6b7ager@chromium.org// This file is distributed under the University of Illinois Open Source 65ec4892aef9cca42940d7d92302abf674365f6b7ager@chromium.org// License. See LICENSE.TXT for details. 75ec4892aef9cca42940d7d92302abf674365f6b7ager@chromium.org// 89085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org//===----------------------------------------------------------------------===// 99085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org// 109085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org// This transformation implements the well known scalar replacement of 119085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org// aggregates transformation. This xform breaks up alloca instructions of 129085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org// aggregate type (structure or array) into individual alloca instructions for 139085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org// each member (if possible). Then, if possible, it transforms the individual 149085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org// alloca instructions into nice clean scalar SSA form. 159085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org// 169085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org// This combines a simple SRoA algorithm with the Mem2Reg algorithm because they 179085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org// often interact, especially for C++ programs. As such, iterating between 189085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org// SRoA, then Mem2Reg until we run out of things to promote works well. 199085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org// 209085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org//===----------------------------------------------------------------------===// 219085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 229085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org#include "llvm/Transforms/Scalar.h" 239085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org#include "llvm/ADT/SetVector.h" 249085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org#include "llvm/ADT/SmallVector.h" 259085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org#include "llvm/ADT/Statistic.h" 269085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org#include "llvm/Analysis/Loads.h" 279085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org#include "llvm/Analysis/ValueTracking.h" 289085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org#include "llvm/IR/CallSite.h" 299085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org#include "llvm/IR/Constants.h" 309085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org#include "llvm/IR/DIBuilder.h" 319085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org#include "llvm/IR/DataLayout.h" 329085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org#include "llvm/IR/DebugInfo.h" 3356454717593e7552d6846198b8e0f661fa36a3cayangguo@chromium.org#include "llvm/IR/DerivedTypes.h" 349085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org#include "llvm/IR/Dominators.h" 359085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org#include "llvm/IR/Function.h" 369085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org#include "llvm/IR/GetElementPtrTypeIterator.h" 379085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org#include "llvm/IR/GlobalVariable.h" 389085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org#include "llvm/IR/IRBuilder.h" 399085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org#include "llvm/IR/Instructions.h" 40c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org#include "llvm/IR/IntrinsicInst.h" 41c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org#include "llvm/IR/LLVMContext.h" 4271affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org#include "llvm/IR/Module.h" 4371affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org#include "llvm/IR/Operator.h" 449085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org#include "llvm/Pass.h" 45e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org#include "llvm/Support/Debug.h" 46e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org#include "llvm/Support/ErrorHandling.h" 47e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org#include "llvm/Support/MathExtras.h" 481b3afd1cab9087ca3c4e585d3da77d374d65c082mstarzinger@chromium.org#include "llvm/Support/raw_ostream.h" 4940b9da37a45dabf86bd82a39e885f2921f47fc08fschneider@chromium.org#include "llvm/Transforms/Utils/Local.h" 5040b9da37a45dabf86bd82a39e885f2921f47fc08fschneider@chromium.org#include "llvm/Transforms/Utils/PromoteMemToReg.h" 51e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org#include "llvm/Transforms/Utils/SSAUpdater.h" 52e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.orgusing namespace llvm; 531b3afd1cab9087ca3c4e585d3da77d374d65c082mstarzinger@chromium.org 5440b9da37a45dabf86bd82a39e885f2921f47fc08fschneider@chromium.org#define DEBUG_TYPE "scalarrepl" 5540b9da37a45dabf86bd82a39e885f2921f47fc08fschneider@chromium.org 56b9d7da12d4486aa0a9d6660de46d977198076e77sgjesse@chromium.orgSTATISTIC(NumReplaced, "Number of allocas broken up"); 57b9d7da12d4486aa0a9d6660de46d977198076e77sgjesse@chromium.orgSTATISTIC(NumPromoted, "Number of allocas promoted"); 581b3afd1cab9087ca3c4e585d3da77d374d65c082mstarzinger@chromium.orgSTATISTIC(NumAdjusted, "Number of scalar allocas adjusted to allow promotion"); 5940b9da37a45dabf86bd82a39e885f2921f47fc08fschneider@chromium.orgSTATISTIC(NumConverted, "Number of aggregates converted to scalar"); 6040b9da37a45dabf86bd82a39e885f2921f47fc08fschneider@chromium.org 61b9d7da12d4486aa0a9d6660de46d977198076e77sgjesse@chromium.orgnamespace { 62b9d7da12d4486aa0a9d6660de46d977198076e77sgjesse@chromium.org struct SROA : public FunctionPass { 631b3afd1cab9087ca3c4e585d3da77d374d65c082mstarzinger@chromium.org SROA(int T, bool hasDT, char &ID, int ST, int AT, int SLT) 6440b9da37a45dabf86bd82a39e885f2921f47fc08fschneider@chromium.org : FunctionPass(ID), HasDomTree(hasDT) { 6540b9da37a45dabf86bd82a39e885f2921f47fc08fschneider@chromium.org if (T == -1) 66e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org SRThreshold = 128; 67e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org else 689085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org SRThreshold = T; 699085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (ST == -1) 709085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org StructMemberThreshold = 32; 719085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org else 729085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org StructMemberThreshold = ST; 739085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (AT == -1) 749085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org ArrayElementThreshold = 8; 759085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org else 769085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org ArrayElementThreshold = AT; 779085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (SLT == -1) 789085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // Do not limit the scalar integer load size if no threshold is given. 799085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org ScalarLoadThreshold = -1; 809085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org else 819085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org ScalarLoadThreshold = SLT; 829085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 839085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 849085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org bool runOnFunction(Function &F) override; 859085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 869085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org bool performScalarRepl(Function &F); 879085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org bool performPromotion(Function &F); 889085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 899085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org private: 909085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org bool HasDomTree; 91a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org const DataLayout *DL; 92a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org 93a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org /// DeadInsts - Keep track of instructions we have made dead, so that 94a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org /// we can remove them after we are done working. 95a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org SmallVector<Value*, 32> DeadInsts; 96b08986cb66c3f6687247cb6da186c1e73057e399whesse@chromium.org 97a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org /// AllocaInfo - When analyzing uses of an alloca instruction, this captures 98a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org /// information about the uses. All these fields are initialized to false 99a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org /// and set to true when something is learned. 100a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org struct AllocaInfo { 101c6c5718277d4047fad1e034396228ce15571b5a4sgjesse@chromium.org /// The alloca to promote. 1023a5fd78f0ca6c2827bb05f69a373d152a9ce6ff3fschneider@chromium.org AllocaInst *AI; 103c6c5718277d4047fad1e034396228ce15571b5a4sgjesse@chromium.org 104c6c5718277d4047fad1e034396228ce15571b5a4sgjesse@chromium.org /// CheckedPHIs - This is a set of verified PHI nodes, to prevent infinite 105c6c5718277d4047fad1e034396228ce15571b5a4sgjesse@chromium.org /// looping and avoid redundant work. 106c6c5718277d4047fad1e034396228ce15571b5a4sgjesse@chromium.org SmallPtrSet<PHINode*, 8> CheckedPHIs; 1073a5fd78f0ca6c2827bb05f69a373d152a9ce6ff3fschneider@chromium.org 108c6c5718277d4047fad1e034396228ce15571b5a4sgjesse@chromium.org /// isUnsafe - This is set to true if the alloca cannot be SROA'd. 109c6c5718277d4047fad1e034396228ce15571b5a4sgjesse@chromium.org bool isUnsafe : 1; 110c6c5718277d4047fad1e034396228ce15571b5a4sgjesse@chromium.org 111a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org /// isMemCpySrc - This is true if this aggregate is memcpy'd from. 112a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org bool isMemCpySrc : 1; 113a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org 114a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org /// isMemCpyDst - This is true if this aggregate is memcpy'd into. 115a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org bool isMemCpyDst : 1; 116c6c5718277d4047fad1e034396228ce15571b5a4sgjesse@chromium.org 117c6c5718277d4047fad1e034396228ce15571b5a4sgjesse@chromium.org /// hasSubelementAccess - This is true if a subelement of the alloca is 118a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org /// ever accessed, or false if the alloca is only accessed with mem 119a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org /// intrinsics or load/store that only access the entire alloca at once. 120a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org bool hasSubelementAccess : 1; 121a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org 122c6c5718277d4047fad1e034396228ce15571b5a4sgjesse@chromium.org /// hasALoadOrStore - This is true if there are any loads or stores to it. 123b08986cb66c3f6687247cb6da186c1e73057e399whesse@chromium.org /// The alloca may just be accessed with memcpy, for example, which would 124a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org /// not set this. 125a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org bool hasALoadOrStore : 1; 126a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org 127a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org explicit AllocaInfo(AllocaInst *ai) 12884bcc559ac20fb04f806e97d28a314b20b58fd60svenpanne@chromium.org : AI(ai), isUnsafe(false), isMemCpySrc(false), isMemCpyDst(false), 129eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org hasSubelementAccess(false), hasALoadOrStore(false) {} 130755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org }; 131755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org 132a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org /// SRThreshold - The maximum alloca size to considered for SROA. 1334a1fe7d5e92fdb673d5f05d5ddf7b1ed703ba18dwhesse@chromium.org unsigned SRThreshold; 13456454717593e7552d6846198b8e0f661fa36a3cayangguo@chromium.org 13556454717593e7552d6846198b8e0f661fa36a3cayangguo@chromium.org /// StructMemberThreshold - The maximum number of members a struct can 1364a1fe7d5e92fdb673d5f05d5ddf7b1ed703ba18dwhesse@chromium.org /// contain to be considered for SROA. 1379085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org unsigned StructMemberThreshold; 1389085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 1399085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org /// ArrayElementThreshold - The maximum number of elements an array can 1404a1fe7d5e92fdb673d5f05d5ddf7b1ed703ba18dwhesse@chromium.org /// have to be considered for SROA. 141eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org unsigned ArrayElementThreshold; 1429085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 1439085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org /// ScalarLoadThreshold - The maximum size in bits of scalars to load when 1445aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org /// converting to scalar 1455aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org unsigned ScalarLoadThreshold; 1465aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org 1475aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org void MarkUnsafe(AllocaInfo &I, Instruction *User) { 1485aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org I.isUnsafe = true; 1495aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org DEBUG(dbgs() << " Transformation preventing inst: " << *User << '\n'); 1505aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org } 1515aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org 1525aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org bool isSafeAllocaToScalarRepl(AllocaInst *AI); 1535aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org 1545aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org void isSafeForScalarRepl(Instruction *I, uint64_t Offset, AllocaInfo &Info); 1555c838251403b0be9a882540f1922577abba4c872ager@chromium.org void isSafePHISelectUseForScalarRepl(Instruction *User, uint64_t Offset, 1565c838251403b0be9a882540f1922577abba4c872ager@chromium.org AllocaInfo &Info); 1579085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org void isSafeGEP(GetElementPtrInst *GEPI, uint64_t &Offset, AllocaInfo &Info); 1580ee099beef2c2b38743d657b84a30b626d9178ecager@chromium.org void isSafeMemAccess(uint64_t Offset, uint64_t MemSize, 159c6c5718277d4047fad1e034396228ce15571b5a4sgjesse@chromium.org Type *MemOpType, bool isStore, AllocaInfo &Info, 1603a5fd78f0ca6c2827bb05f69a373d152a9ce6ff3fschneider@chromium.org Instruction *TheAccess, bool AllowWholeAccess); 1613a5fd78f0ca6c2827bb05f69a373d152a9ce6ff3fschneider@chromium.org bool TypeHasComponent(Type *T, uint64_t Offset, uint64_t Size); 1629085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org uint64_t FindElementAndOffset(Type *&T, uint64_t &Offset, 1639085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Type *&IdxTy); 1641456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org 1651456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org void DoScalarReplacement(AllocaInst *AI, 1661456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org std::vector<AllocaInst*> &WorkList); 1671456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org void DeleteDeadInstructions(); 1681456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org 1691456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org void RewriteForScalarRepl(Instruction *I, AllocaInst *AI, uint64_t Offset, 1701456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org SmallVectorImpl<AllocaInst *> &NewElts); 1711456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org void RewriteBitCast(BitCastInst *BC, AllocaInst *AI, uint64_t Offset, 1721456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org SmallVectorImpl<AllocaInst *> &NewElts); 1731456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org void RewriteGEP(GetElementPtrInst *GEPI, AllocaInst *AI, uint64_t Offset, 1741456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org SmallVectorImpl<AllocaInst *> &NewElts); 1751456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org void RewriteLifetimeIntrinsic(IntrinsicInst *II, AllocaInst *AI, 1761456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org uint64_t Offset, 1771456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org SmallVectorImpl<AllocaInst *> &NewElts); 1781456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org void RewriteMemIntrinUserOfAlloca(MemIntrinsic *MI, Instruction *Inst, 1791456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org AllocaInst *AI, 1801456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org SmallVectorImpl<AllocaInst *> &NewElts); 1811456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org void RewriteStoreUserOfWholeAlloca(StoreInst *SI, AllocaInst *AI, 1821456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org SmallVectorImpl<AllocaInst *> &NewElts); 1831456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org void RewriteLoadUserOfWholeAlloca(LoadInst *LI, AllocaInst *AI, 1841456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org SmallVectorImpl<AllocaInst *> &NewElts); 1851456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org bool ShouldAttemptScalarRepl(AllocaInst *AI); 1861456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org }; 1871456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org 1881456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org // SROA_DT - SROA that uses DominatorTree. 1891456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org struct SROA_DT : public SROA { 1901456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org static char ID; 1911456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org public: 1921456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org SROA_DT(int T = -1, int ST = -1, int AT = -1, int SLT = -1) : 1931456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org SROA(T, true, ID, ST, AT, SLT) { 1941456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org initializeSROA_DTPass(*PassRegistry::getPassRegistry()); 1951456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org } 1961456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org 1971456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org // getAnalysisUsage - This pass does not require any passes, but we know it 1981456e708d277e725ca42a03463af16fe471c9210jkummerow@chromium.org // will not alter the CFG, so say so. 1995aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org void getAnalysisUsage(AnalysisUsage &AU) const override { 2005aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org AU.addRequired<DominatorTreeWrapperPass>(); 2019085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org AU.setPreservesCFG(); 202a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org } 203a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org }; 204a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org 205a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org // SROA_SSAUp - SROA that uses SSAUpdater. 206a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org struct SROA_SSAUp : public SROA { 207a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org static char ID; 208a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org public: 209a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org SROA_SSAUp(int T = -1, int ST = -1, int AT = -1, int SLT = -1) : 210c6c5718277d4047fad1e034396228ce15571b5a4sgjesse@chromium.org SROA(T, false, ID, ST, AT, SLT) { 211c6c5718277d4047fad1e034396228ce15571b5a4sgjesse@chromium.org initializeSROA_SSAUpPass(*PassRegistry::getPassRegistry()); 212c6c5718277d4047fad1e034396228ce15571b5a4sgjesse@chromium.org } 213c6c5718277d4047fad1e034396228ce15571b5a4sgjesse@chromium.org 214c6c5718277d4047fad1e034396228ce15571b5a4sgjesse@chromium.org // getAnalysisUsage - This pass does not require any passes, but we know it 215c6c5718277d4047fad1e034396228ce15571b5a4sgjesse@chromium.org // will not alter the CFG, so say so. 216a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org void getAnalysisUsage(AnalysisUsage &AU) const override { 217a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org AU.setPreservesCFG(); 218a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org } 219a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org }; 220a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org 221a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org} 222a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org 223a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.orgchar SROA_DT::ID = 0; 224a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.orgchar SROA_SSAUp::ID = 0; 225a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org 226a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.orgINITIALIZE_PASS_BEGIN(SROA_DT, "scalarrepl", 227a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org "Scalar Replacement of Aggregates (DT)", false, false) 228a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.orgINITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass) 229a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.orgINITIALIZE_PASS_END(SROA_DT, "scalarrepl", 230a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org "Scalar Replacement of Aggregates (DT)", false, false) 231a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org 232a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.orgINITIALIZE_PASS_BEGIN(SROA_SSAUp, "scalarrepl-ssa", 233a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org "Scalar Replacement of Aggregates (SSAUp)", false, false) 234a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.orgINITIALIZE_PASS_END(SROA_SSAUp, "scalarrepl-ssa", 235a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org "Scalar Replacement of Aggregates (SSAUp)", false, false) 236a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org 237a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org// Public interface to the ScalarReplAggregates pass 238c3b670ff19220959730d7886892bc4beb95d2ebaerik.corry@gmail.comFunctionPass *llvm::createScalarReplAggregatesPass(int Threshold, 239c3b670ff19220959730d7886892bc4beb95d2ebaerik.corry@gmail.com bool UseDomTree, 240c3b670ff19220959730d7886892bc4beb95d2ebaerik.corry@gmail.com int StructMemberThreshold, 241c3b670ff19220959730d7886892bc4beb95d2ebaerik.corry@gmail.com int ArrayElementThreshold, 242c3b670ff19220959730d7886892bc4beb95d2ebaerik.corry@gmail.com int ScalarLoadThreshold) { 243c3b670ff19220959730d7886892bc4beb95d2ebaerik.corry@gmail.com if (UseDomTree) 244a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org return new SROA_DT(Threshold, StructMemberThreshold, ArrayElementThreshold, 245c6c5718277d4047fad1e034396228ce15571b5a4sgjesse@chromium.org ScalarLoadThreshold); 2464a1fe7d5e92fdb673d5f05d5ddf7b1ed703ba18dwhesse@chromium.org return new SROA_SSAUp(Threshold, StructMemberThreshold, 2479085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org ArrayElementThreshold, ScalarLoadThreshold); 2489085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org} 2499085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 2509085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 25186f77b7fe492ed2bdfbf4e1147dab2f09c7d7003kasperl@chromium.org//===----------------------------------------------------------------------===// 25286f77b7fe492ed2bdfbf4e1147dab2f09c7d7003kasperl@chromium.org// Convert To Scalar Optimization. 25386f77b7fe492ed2bdfbf4e1147dab2f09c7d7003kasperl@chromium.org//===----------------------------------------------------------------------===// 25486f77b7fe492ed2bdfbf4e1147dab2f09c7d7003kasperl@chromium.org 25586f77b7fe492ed2bdfbf4e1147dab2f09c7d7003kasperl@chromium.orgnamespace { 25686f77b7fe492ed2bdfbf4e1147dab2f09c7d7003kasperl@chromium.org/// ConvertToScalarInfo - This class implements the "Convert To Scalar" 25786f77b7fe492ed2bdfbf4e1147dab2f09c7d7003kasperl@chromium.org/// optimization, which scans the uses of an alloca and determines if it can 25886f77b7fe492ed2bdfbf4e1147dab2f09c7d7003kasperl@chromium.org/// rewrite it in terms of a single new alloca that can be mem2reg'd. 25986f77b7fe492ed2bdfbf4e1147dab2f09c7d7003kasperl@chromium.orgclass ConvertToScalarInfo { 26086f77b7fe492ed2bdfbf4e1147dab2f09c7d7003kasperl@chromium.org /// AllocaSize - The size of the alloca being considered in bytes. 26186f77b7fe492ed2bdfbf4e1147dab2f09c7d7003kasperl@chromium.org unsigned AllocaSize; 2629085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org const DataLayout &DL; 2639085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org unsigned ScalarLoadThreshold; 2649085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 265b95b98b0c30bcd40b657aa45f6cd75a46a4772adfschneider@chromium.org /// IsNotTrivial - This is set to true if there is some access to the object 266b95b98b0c30bcd40b657aa45f6cd75a46a4772adfschneider@chromium.org /// which means that mem2reg can't promote it. 267b95b98b0c30bcd40b657aa45f6cd75a46a4772adfschneider@chromium.org bool IsNotTrivial; 268b95b98b0c30bcd40b657aa45f6cd75a46a4772adfschneider@chromium.org 269b95b98b0c30bcd40b657aa45f6cd75a46a4772adfschneider@chromium.org /// ScalarKind - Tracks the kind of alloca being considered for promotion, 270b95b98b0c30bcd40b657aa45f6cd75a46a4772adfschneider@chromium.org /// computed based on the uses of the alloca rather than the LLVM type system. 271b95b98b0c30bcd40b657aa45f6cd75a46a4772adfschneider@chromium.org enum { 272b95b98b0c30bcd40b657aa45f6cd75a46a4772adfschneider@chromium.org Unknown, 273b95b98b0c30bcd40b657aa45f6cd75a46a4772adfschneider@chromium.org 274b95b98b0c30bcd40b657aa45f6cd75a46a4772adfschneider@chromium.org // Accesses via GEPs that are consistent with element access of a vector 275b95b98b0c30bcd40b657aa45f6cd75a46a4772adfschneider@chromium.org // type. This will not be converted into a vector unless there is a later 276b95b98b0c30bcd40b657aa45f6cd75a46a4772adfschneider@chromium.org // access using an actual vector type. 277b95b98b0c30bcd40b657aa45f6cd75a46a4772adfschneider@chromium.org ImplicitVector, 278b95b98b0c30bcd40b657aa45f6cd75a46a4772adfschneider@chromium.org 279b95b98b0c30bcd40b657aa45f6cd75a46a4772adfschneider@chromium.org // Accesses via vector operations and GEPs that are consistent with the 280b95b98b0c30bcd40b657aa45f6cd75a46a4772adfschneider@chromium.org // layout of a vector type. 2819085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Vector, 282a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org 283a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org // An integer bag-of-bits with bitwise operations for insertion and 284a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org // extraction. Any combination of types can be converted into this kind 285a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org // of scalar. 2869085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Integer 2879085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } ScalarKind; 2889085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 2899085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org /// VectorTy - This tracks the type that we should promote the vector to if 2909085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org /// it is possible to turn it into a vector. This starts out null, and if it 2919085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org /// isn't possible to turn into a vector type, it gets set to VoidTy. 2929085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org VectorType *VectorTy; 2939085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 2949085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org /// HadNonMemTransferAccess - True if there is at least one access to the 2959085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org /// alloca that is not a MemTransferInst. We don't want to turn structs into 2969085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org /// large integers unless there is some potential for optimization. 2979085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org bool HadNonMemTransferAccess; 2989085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 2999085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org /// HadDynamicAccess - True if some element of this alloca was dynamic. 3009085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org /// We don't yet have support for turning a dynamic access into a large 3019085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org /// integer. 3029085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org bool HadDynamicAccess; 3039085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 3049085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.orgpublic: 3059085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org explicit ConvertToScalarInfo(unsigned Size, const DataLayout &DL, 3069085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org unsigned SLT) 3079d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com : AllocaSize(Size), DL(DL), ScalarLoadThreshold(SLT), IsNotTrivial(false), 3089d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com ScalarKind(Unknown), VectorTy(nullptr), HadNonMemTransferAccess(false), 3099d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com HadDynamicAccess(false) { } 3109d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com 3119085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org AllocaInst *TryConvert(AllocaInst *AI); 3129085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 3139085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.orgprivate: 3149085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org bool CanConvertToScalar(Value *V, uint64_t Offset, Value* NonConstantIdx); 3159085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org void MergeInTypeForLoadOrStore(Type *In, uint64_t Offset); 3169085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org bool MergeInVectorType(VectorType *VInTy, uint64_t Offset); 3179d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com void ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI, uint64_t Offset, 3189d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com Value *NonConstantIdx); 3199085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 3209085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Value *ConvertScalar_ExtractValue(Value *NV, Type *ToType, 3219085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org uint64_t Offset, Value* NonConstantIdx, 3229085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org IRBuilder<> &Builder); 3239085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Value *ConvertScalar_InsertValue(Value *StoredVal, Value *ExistingVal, 3249085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org uint64_t Offset, Value* NonConstantIdx, 3259085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org IRBuilder<> &Builder); 3265ad5acef6bd4ebc785f946d8bcc2a88b1e031827ricow@chromium.org}; 3275ad5acef6bd4ebc785f946d8bcc2a88b1e031827ricow@chromium.org} // end anonymous namespace. 3285ad5acef6bd4ebc785f946d8bcc2a88b1e031827ricow@chromium.org 3295ad5acef6bd4ebc785f946d8bcc2a88b1e031827ricow@chromium.org 3309085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// TryConvert - Analyze the specified alloca, and if it is safe to do so, 3319085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// rewrite it to be a new alloca which is mem2reg'able. This returns the new 3329085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// alloca if possible or null if not. 3339085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.orgAllocaInst *ConvertToScalarInfo::TryConvert(AllocaInst *AI) { 3349085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // If we can't convert this scalar, or if mem2reg can trivially do it, bail 3359085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // out. 3369085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (!CanConvertToScalar(AI, 0, nullptr) || !IsNotTrivial) 3379085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return nullptr; 3389085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 3399085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // If an alloca has only memset / memcpy uses, it may still have an Unknown 3409085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // ScalarKind. Treat it as an Integer below. 3419085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (ScalarKind == Unknown) 3429085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org ScalarKind = Integer; 3439085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 3449085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (ScalarKind == Vector && VectorTy->getBitWidth() != AllocaSize * 8) 3459085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org ScalarKind = Integer; 3469085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 3479085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // If we were able to find a vector type that can handle this with 3489085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // insert/extract elements, and if there was at least one use that had 3499085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // a vector type, promote this to a vector. We don't want to promote 3509085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // random stuff that doesn't use vectors (e.g. <9 x double>) because then 3519085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // we just get a lot of insert/extracts. If at least one vector is 3529085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // involved, then we probably really do have a union of vector/array. 3539085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Type *NewTy; 3549085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (ScalarKind == Vector) { 3555ad5acef6bd4ebc785f946d8bcc2a88b1e031827ricow@chromium.org assert(VectorTy && "Missing type for vector scalar."); 3569085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org DEBUG(dbgs() << "CONVERT TO VECTOR: " << *AI << "\n TYPE = " 3579085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org << *VectorTy << '\n'); 3589085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org NewTy = VectorTy; // Use the vector type. 3599085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } else { 3609085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org unsigned BitWidth = AllocaSize * 8; 361755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org 3629085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // Do not convert to scalar integer if the alloca size exceeds the 3639085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // scalar load threshold. 364755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org if (BitWidth > ScalarLoadThreshold) 3659085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return nullptr; 3669085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 3679085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if ((ScalarKind == ImplicitVector || ScalarKind == Integer) && 3689085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org !HadNonMemTransferAccess && !DL.fitsInLegalInteger(BitWidth)) 3699085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return nullptr; 3709085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // Dynamic accesses on integers aren't yet supported. They need us to shift 3719085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // by a dynamic amount which could be difficult to work out as we might not 3729085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // know whether to use a left or right shift. 3739085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (ScalarKind == Integer && HadDynamicAccess) 3743e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org return nullptr; 3753e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org 3763e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org DEBUG(dbgs() << "CONVERT TO SCALAR INTEGER: " << *AI << "\n"); 3773e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org // Create and insert the integer alloca. 3783e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org NewTy = IntegerType::get(AI->getContext(), BitWidth); 3793e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org } 3809085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org AllocaInst *NewAI = new AllocaInst(NewTy, nullptr, "", 3819085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org AI->getParent()->begin()); 3829085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org ConvertUsesToScalar(AI, NewAI, 0, nullptr); 3839085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return NewAI; 3849085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org} 3859085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 386eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org/// MergeInTypeForLoadOrStore - Add the 'In' type to the accumulated vector type 3879085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// (VectorTy) so far at the offset specified by Offset (which is specified in 3889085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// bytes). 389755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// 390755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// There are two cases we handle here: 391755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// 1) A union of vector types of the same size and potentially its elements. 392755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// Here we turn element accesses into insert/extract element operations. 3939085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// This promotes a <4 x float> with a store of float to the third element 3949085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// into a <4 x float> that uses insert element. 395755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// 2) A fully general blob of memory, which we turn into some (potentially 396755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// large) integer type with extract and insert operations where the loads 397755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// and stores would mutate the memory. We mark this by setting VectorTy 3989085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// to VoidTy. 3999155e252524a2bf92aecd27493feafed86702312kmillikin@chromium.orgvoid ConvertToScalarInfo::MergeInTypeForLoadOrStore(Type *In, 4009155e252524a2bf92aecd27493feafed86702312kmillikin@chromium.org uint64_t Offset) { 4019155e252524a2bf92aecd27493feafed86702312kmillikin@chromium.org // If we already decided to turn this into a blob of integer memory, there is 4029155e252524a2bf92aecd27493feafed86702312kmillikin@chromium.org // nothing to be done. 4039155e252524a2bf92aecd27493feafed86702312kmillikin@chromium.org if (ScalarKind == Integer) 4040ee099beef2c2b38743d657b84a30b626d9178ecager@chromium.org return; 4050ee099beef2c2b38743d657b84a30b626d9178ecager@chromium.org 4060ee099beef2c2b38743d657b84a30b626d9178ecager@chromium.org // If this could be contributing to a vector, analyze it. 4070ee099beef2c2b38743d657b84a30b626d9178ecager@chromium.org 408eb96f4fd17b379ad2247264f82af1100f448779bricow@chromium.org // If the In type is a vector that is the same size as the alloca, see if it 409eb96f4fd17b379ad2247264f82af1100f448779bricow@chromium.org // matches the existing VecTy. 410eb96f4fd17b379ad2247264f82af1100f448779bricow@chromium.org if (VectorType *VInTy = dyn_cast<VectorType>(In)) { 411eb96f4fd17b379ad2247264f82af1100f448779bricow@chromium.org if (MergeInVectorType(VInTy, Offset)) 412eb96f4fd17b379ad2247264f82af1100f448779bricow@chromium.org return; 413eb96f4fd17b379ad2247264f82af1100f448779bricow@chromium.org } else if (In->isFloatTy() || In->isDoubleTy() || 414eb96f4fd17b379ad2247264f82af1100f448779bricow@chromium.org (In->isIntegerTy() && In->getPrimitiveSizeInBits() >= 8 && 4159085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org isPowerOf2_32(In->getPrimitiveSizeInBits()))) { 4169085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // Full width accesses can be ignored, because they can always be turned 41730ce411529579186181838984710b0b0980857aaricow@chromium.org // into bitcasts. 4180ee099beef2c2b38743d657b84a30b626d9178ecager@chromium.org unsigned EltSize = In->getPrimitiveSizeInBits()/8; 4190ee099beef2c2b38743d657b84a30b626d9178ecager@chromium.org if (EltSize == AllocaSize) 4209085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return; 421e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org 4229085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // If we're accessing something that could be an element of a vector, see 423755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // if the implied vector agrees with what we already have and if Offset is 4249085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // compatible with it. 4259085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (Offset % EltSize == 0 && AllocaSize % EltSize == 0 && 426755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org (!VectorTy || EltSize == VectorTy->getElementType() 4279085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org ->getPrimitiveSizeInBits()/8)) { 4289085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (!VectorTy) { 429755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org ScalarKind = ImplicitVector; 430755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org VectorTy = VectorType::get(In, AllocaSize/EltSize); 431755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org } 432755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org return; 4339085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 434755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org } 4359085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 4369085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // Otherwise, we have a case that we can't handle with an optimized vector 4379085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // form. We can still turn this into a large integer. 4389085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org ScalarKind = Integer; 4399085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org} 4409085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 4413e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org/// MergeInVectorType - Handles the vector case of MergeInTypeForLoadOrStore, 4423e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org/// returning true if the type was successfully merged and false otherwise. 4433e87580939cb78c5802369f723680d4a16cc2902ager@chromium.orgbool ConvertToScalarInfo::MergeInVectorType(VectorType *VInTy, 4449085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org uint64_t Offset) { 4453e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org if (VInTy->getBitWidth()/8 == AllocaSize && Offset == 0) { 4469085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // If we're storing/loading a vector of the right size, allow it as a 447c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org // vector. If this the first vector we see, remember the type so that 4489085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // we know the element size. If this is a subsequent access, ignore it 4499085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // even if it is a differing type but the same size. Worst case we can 4509085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // bitcast the resultant vectors. 451c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org if (!VectorTy) 452ea88ce93dcb41a9200ec8747ae7642a5db1f4ce7sgjesse@chromium.org VectorTy = VInTy; 4539085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org ScalarKind = Vector; 454c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org return true; 455c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org } 4569d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com 4579d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com return false; 4587a6fc815d62905d0c52705b96225b1bd23e00a43jkummerow@chromium.org} 4599d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com 4609d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com/// CanConvertToScalar - V is a pointer. If we can convert the pointee and all 4619d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com/// its accesses to a single vector type, return true and set VecTy to 462e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org/// the new type. If we could convert the alloca into a single promotable 4639085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// integer, return true but set VecTy to VoidTy. Further, if the use is not a 464c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org/// completely trivial use that mem2reg could promote, set IsNotTrivial. Offset 465c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org/// is the current offset from the base of the alloca being analyzed. 4669085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// 467c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org/// If we see at least one access to the value that is as a vector type, set the 468c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org/// SawVec flag. 469c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.orgbool ConvertToScalarInfo::CanConvertToScalar(Value *V, uint64_t Offset, 470c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org Value* NonConstantIdx) { 471c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org for (User *U : V->users()) { 472c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org Instruction *UI = cast<Instruction>(U); 473c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org 474c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org if (LoadInst *LI = dyn_cast<LoadInst>(UI)) { 475c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org // Don't break volatile loads. 476c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org if (!LI->isSimple()) 4779085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return false; 478c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org // Don't touch MMX operations. 479c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org if (LI->getType()->isX86_MMXTy()) 4809085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return false; 4819085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org HadNonMemTransferAccess = true; 4829085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org MergeInTypeForLoadOrStore(LI->getType(), Offset); 48383e168294456ca2f02db421a635f7d5f5d023966kmillikin@chromium.org continue; 4849085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 485c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org 486c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org if (StoreInst *SI = dyn_cast<StoreInst>(UI)) { 487c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org // Storing the pointer, not into the value? 488ea88ce93dcb41a9200ec8747ae7642a5db1f4ce7sgjesse@chromium.org if (SI->getOperand(0) == V || !SI->isSimple()) return false; 489c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org // Don't touch MMX operations. 490c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org if (SI->getOperand(0)->getType()->isX86_MMXTy()) 491c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org return false; 492c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org HadNonMemTransferAccess = true; 493c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org MergeInTypeForLoadOrStore(SI->getOperand(0)->getType(), Offset); 494c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org continue; 495c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org } 496ea88ce93dcb41a9200ec8747ae7642a5db1f4ce7sgjesse@chromium.org 497ea88ce93dcb41a9200ec8747ae7642a5db1f4ce7sgjesse@chromium.org if (BitCastInst *BCI = dyn_cast<BitCastInst>(UI)) { 498c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org if (!onlyUsedByLifetimeMarkers(BCI)) 499c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org IsNotTrivial = true; // Can't be mem2reg'd. 500c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org if (!CanConvertToScalar(BCI, Offset, NonConstantIdx)) 501c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org return false; 5029085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org continue; 50383e168294456ca2f02db421a635f7d5f5d023966kmillikin@chromium.org } 5049085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 505ea88ce93dcb41a9200ec8747ae7642a5db1f4ce7sgjesse@chromium.org if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(UI)) { 506c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org // If this is a GEP with a variable indices, we can't handle it. 5079085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org PointerType* PtrTy = dyn_cast<PointerType>(GEP->getPointerOperandType()); 50883e168294456ca2f02db421a635f7d5f5d023966kmillikin@chromium.org if (!PtrTy) 5099085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return false; 510c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org 5119085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // Compute the offset that this GEP adds to the pointer. 5129085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org SmallVector<Value*, 8> Indices(GEP->op_begin()+1, GEP->op_end()); 513ea88ce93dcb41a9200ec8747ae7642a5db1f4ce7sgjesse@chromium.org Value *GEPNonConstantIdx = nullptr; 514c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org if (!GEP->hasAllConstantIndices()) { 5153e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org if (!isa<VectorType>(PtrTy->getElementType())) 5163e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org return false; 517ea88ce93dcb41a9200ec8747ae7642a5db1f4ce7sgjesse@chromium.org if (NonConstantIdx) 518ea88ce93dcb41a9200ec8747ae7642a5db1f4ce7sgjesse@chromium.org return false; 519c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org GEPNonConstantIdx = Indices.pop_back_val(); 520ea88ce93dcb41a9200ec8747ae7642a5db1f4ce7sgjesse@chromium.org if (!GEPNonConstantIdx->getType()->isIntegerTy(32)) 521c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org return false; 522c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org HadDynamicAccess = true; 523c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org } else 524c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org GEPNonConstantIdx = NonConstantIdx; 525c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org uint64_t GEPOffset = DL.getIndexedOffset(PtrTy, 526ea88ce93dcb41a9200ec8747ae7642a5db1f4ce7sgjesse@chromium.org Indices); 527ea88ce93dcb41a9200ec8747ae7642a5db1f4ce7sgjesse@chromium.org // See if all uses can be converted. 5289085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (!CanConvertToScalar(GEP, Offset+GEPOffset, GEPNonConstantIdx)) 5299085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return false; 5309085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org IsNotTrivial = true; // Can't be mem2reg'd. 531ea88ce93dcb41a9200ec8747ae7642a5db1f4ce7sgjesse@chromium.org HadNonMemTransferAccess = true; 5329085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org continue; 5333e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org } 5343e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org 5353e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org // If this is a constant sized memset of a constant value (e.g. 0) we can 5369085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // handle it. 5373e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org if (MemSetInst *MSI = dyn_cast<MemSetInst>(UI)) { 5383e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org // Store to dynamic index. 5393e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org if (NonConstantIdx) 5403e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org return false; 5413e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org // Store of constant value. 5429085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (!isa<ConstantInt>(MSI->getValue())) 5439085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return false; 5449085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 5459085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // Store of constant size. 5469085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org ConstantInt *Len = dyn_cast<ConstantInt>(MSI->getLength()); 5479085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (!Len) 5489085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return false; 5499085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 5509085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // If the size differs from the alloca, we can only convert the alloca to 5519085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // an integer bag-of-bits. 5529085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // FIXME: This should handle all of the cases that are currently accepted 5539085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // as vector element insertions. 5549085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (Len->getZExtValue() != AllocaSize || Offset != 0) 5559085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org ScalarKind = Integer; 5569085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 5579085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org IsNotTrivial = true; // Can't be mem2reg'd. 558c36ce6e8979bbbd43539f0a0effc87ea20dd65cckmillikin@chromium.org HadNonMemTransferAccess = true; 5599085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org continue; 5609085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 561badaffc570baec00166b0ad3bdc96995751a7e13ricow@chromium.org 562badaffc570baec00166b0ad3bdc96995751a7e13ricow@chromium.org // If this is a memcpy or memmove into or out of the whole allocation, we 563badaffc570baec00166b0ad3bdc96995751a7e13ricow@chromium.org // can handle it like a load or store of the scalar type. 564000f7fbc1dfa59e414332fd2898b5da4d44eedd6jkummerow@chromium.org if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(UI)) { 565000f7fbc1dfa59e414332fd2898b5da4d44eedd6jkummerow@chromium.org // Store to dynamic index. 566000f7fbc1dfa59e414332fd2898b5da4d44eedd6jkummerow@chromium.org if (NonConstantIdx) 567000f7fbc1dfa59e414332fd2898b5da4d44eedd6jkummerow@chromium.org return false; 568000f7fbc1dfa59e414332fd2898b5da4d44eedd6jkummerow@chromium.org ConstantInt *Len = dyn_cast<ConstantInt>(MTI->getLength()); 5699085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (!Len || Len->getZExtValue() != AllocaSize || Offset != 0) 5709085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return false; 5719085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 5729085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org IsNotTrivial = true; // Can't be mem2reg'd. 5739085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org continue; 574c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org } 575c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org 576c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org // If this is a lifetime intrinsic, we can handle it. 577c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(UI)) { 578c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org if (II->getIntrinsicID() == Intrinsic::lifetime_start || 579c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org II->getIntrinsicID() == Intrinsic::lifetime_end) { 580c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org continue; 581e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org } 582e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org } 583c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org 58489e18f5599cb4cd462cb1ed324addd7388fb4d60rossberg@chromium.org // Otherwise, we cannot handle this! 58589e18f5599cb4cd462cb1ed324addd7388fb4d60rossberg@chromium.org return false; 58689e18f5599cb4cd462cb1ed324addd7388fb4d60rossberg@chromium.org } 58789e18f5599cb4cd462cb1ed324addd7388fb4d60rossberg@chromium.org 5883811b436bf328d2ace6fe79ce99aeda71f9f06d3ager@chromium.org return true; 589c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org} 59088aa058bdadfa79ae2836d12d6dd2d1c28aa490cdanno@chromium.org 59188aa058bdadfa79ae2836d12d6dd2d1c28aa490cdanno@chromium.org/// ConvertUsesToScalar - Convert all of the users of Ptr to use the new alloca 5923811b436bf328d2ace6fe79ce99aeda71f9f06d3ager@chromium.org/// directly. This happens when we are converting an "integer union" to a 5933811b436bf328d2ace6fe79ce99aeda71f9f06d3ager@chromium.org/// single integer scalar, or when we are converting a "vector union" to a 594c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org/// vector with insert/extractelement instructions. 595c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org/// 596c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org/// Offset is an offset from the original alloca, in bits that need to be 597c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org/// shifted to the right. By the end of this, there should be no uses of Ptr. 598c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.orgvoid ConvertToScalarInfo::ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI, 599c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org uint64_t Offset, 600c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org Value* NonConstantIdx) { 601c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org while (!Ptr->use_empty()) { 602c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org Instruction *User = cast<Instruction>(Ptr->user_back()); 6033811b436bf328d2ace6fe79ce99aeda71f9f06d3ager@chromium.org 60488aa058bdadfa79ae2836d12d6dd2d1c28aa490cdanno@chromium.org if (BitCastInst *CI = dyn_cast<BitCastInst>(User)) { 6059085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org ConvertUsesToScalar(CI, NewAI, Offset, NonConstantIdx); 606c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org CI->eraseFromParent(); 607c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org continue; 608c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org } 609c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org 610c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(User)) { 611c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org // Compute the offset that this GEP adds to the pointer. 612c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org SmallVector<Value*, 8> Indices(GEP->op_begin()+1, GEP->op_end()); 6132356e6fbe66ac3aa027b61cb43a3c3619b3c3a5evegorov@chromium.org Value* GEPNonConstantIdx = nullptr; 6142356e6fbe66ac3aa027b61cb43a3c3619b3c3a5evegorov@chromium.org if (!GEP->hasAllConstantIndices()) { 6152356e6fbe66ac3aa027b61cb43a3c3619b3c3a5evegorov@chromium.org assert(!NonConstantIdx && 6162356e6fbe66ac3aa027b61cb43a3c3619b3c3a5evegorov@chromium.org "Dynamic GEP reading from dynamic GEP unsupported"); 6172356e6fbe66ac3aa027b61cb43a3c3619b3c3a5evegorov@chromium.org GEPNonConstantIdx = Indices.pop_back_val(); 618c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org } else 619c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org GEPNonConstantIdx = NonConstantIdx; 620ac6aa175ab59d65cfb7a88dbb621e1d7f1a80b8fsgjesse@chromium.org uint64_t GEPOffset = DL.getIndexedOffset(GEP->getPointerOperandType(), 62183aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org Indices); 62283aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org ConvertUsesToScalar(GEP, NewAI, Offset+GEPOffset*8, GEPNonConstantIdx); 62383aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org GEP->eraseFromParent(); 624ac6aa175ab59d65cfb7a88dbb621e1d7f1a80b8fsgjesse@chromium.org continue; 625ac6aa175ab59d65cfb7a88dbb621e1d7f1a80b8fsgjesse@chromium.org } 62683aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org 62789e18f5599cb4cd462cb1ed324addd7388fb4d60rossberg@chromium.org IRBuilder<> Builder(User); 628ac6aa175ab59d65cfb7a88dbb621e1d7f1a80b8fsgjesse@chromium.org 6292356e6fbe66ac3aa027b61cb43a3c3619b3c3a5evegorov@chromium.org if (LoadInst *LI = dyn_cast<LoadInst>(User)) { 6302356e6fbe66ac3aa027b61cb43a3c3619b3c3a5evegorov@chromium.org // The load is a bit extract from NewAI shifted right by Offset bits. 6312356e6fbe66ac3aa027b61cb43a3c3619b3c3a5evegorov@chromium.org Value *LoadedVal = Builder.CreateLoad(NewAI); 6325d00b60c201d860c74821f553fdc34f4e057b411lrn@chromium.org Value *NewLoadVal 6335d00b60c201d860c74821f553fdc34f4e057b411lrn@chromium.org = ConvertScalar_ExtractValue(LoadedVal, LI->getType(), Offset, 634d91075f76b836c2cfa4f4e4cc0fb31170df864ccerik.corry@gmail.com NonConstantIdx, Builder); 635d91075f76b836c2cfa4f4e4cc0fb31170df864ccerik.corry@gmail.com LI->replaceAllUsesWith(NewLoadVal); 636496c03a64f12710e837204e261ef155601247895sgjesse@chromium.org LI->eraseFromParent(); 637496c03a64f12710e837204e261ef155601247895sgjesse@chromium.org continue; 638496c03a64f12710e837204e261ef155601247895sgjesse@chromium.org } 639496c03a64f12710e837204e261ef155601247895sgjesse@chromium.org 640496c03a64f12710e837204e261ef155601247895sgjesse@chromium.org if (StoreInst *SI = dyn_cast<StoreInst>(User)) { 641496c03a64f12710e837204e261ef155601247895sgjesse@chromium.org assert(SI->getOperand(0) != Ptr && "Consistency error!"); 642496c03a64f12710e837204e261ef155601247895sgjesse@chromium.org Instruction *Old = Builder.CreateLoad(NewAI, NewAI->getName()+".in"); 643212d964d8f853ddb1fdf3a64037f3af294d55cf3jkummerow@chromium.org Value *New = ConvertScalar_InsertValue(SI->getOperand(0), Old, Offset, 644212d964d8f853ddb1fdf3a64037f3af294d55cf3jkummerow@chromium.org NonConstantIdx, Builder); 645496c03a64f12710e837204e261ef155601247895sgjesse@chromium.org Builder.CreateStore(New, NewAI); 6462356e6fbe66ac3aa027b61cb43a3c3619b3c3a5evegorov@chromium.org SI->eraseFromParent(); 6479085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 6489085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // If the load we just inserted is now dead, then the inserted store 6499085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // overwrote the entire thing. 65071affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org if (Old->use_empty()) 65171affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org Old->eraseFromParent(); 65271affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org continue; 65371affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org } 65471affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org 655eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org // If this is a constant sized memset of a constant value (e.g. 0) we can 656eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org // transform it into a store of the expanded constant value. 65771affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org if (MemSetInst *MSI = dyn_cast<MemSetInst>(User)) { 65871affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org assert(MSI->getRawDest() == Ptr && "Consistency error!"); 65971affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org assert(!NonConstantIdx && "Cannot replace dynamic memset with insert"); 66071affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org int64_t SNumBytes = cast<ConstantInt>(MSI->getLength())->getSExtValue(); 66171affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org if (SNumBytes > 0 && (SNumBytes >> 32) == 0) { 66271affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org unsigned NumBytes = static_cast<unsigned>(SNumBytes); 66371affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org unsigned Val = cast<ConstantInt>(MSI->getValue())->getZExtValue(); 66471affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org 6659085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // Compute the value replicated the right number of times. 6669085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org APInt APVal(NumBytes*8, Val); 6679085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 66883aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org // Splat the value if non-zero. 6699085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (Val) 67064e3a4be4a99f31920128de34573c8ac9038de42ricow@chromium.org for (unsigned i = 1; i != NumBytes; ++i) 6715ad5acef6bd4ebc785f946d8bcc2a88b1e031827ricow@chromium.org APVal |= APVal << 8; 6725ad5acef6bd4ebc785f946d8bcc2a88b1e031827ricow@chromium.org 6739085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Instruction *Old = Builder.CreateLoad(NewAI, NewAI->getName()+".in"); 6749085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Value *New = ConvertScalar_InsertValue( 675e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org ConstantInt::get(User->getContext(), APVal), 676e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org Old, Offset, nullptr, Builder); 6779085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Builder.CreateStore(New, NewAI); 678e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org 6790ee099beef2c2b38743d657b84a30b626d9178ecager@chromium.org // If the load we just inserted is now dead, then the memset overwrote 6800ee099beef2c2b38743d657b84a30b626d9178ecager@chromium.org // the entire thing. 6810ee099beef2c2b38743d657b84a30b626d9178ecager@chromium.org if (Old->use_empty()) 6829085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Old->eraseFromParent(); 6839085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 6849085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org MSI->eraseFromParent(); 6859085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org continue; 6869085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 6879085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 688e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // If this is a memcpy or memmove into or out of the whole allocation, we 6899085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // can handle it like a load or store of the scalar type. 6909085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(User)) { 6919085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org assert(Offset == 0 && "must be store to start of alloca"); 692755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org assert(!NonConstantIdx && "Cannot replace dynamic transfer with insert"); 693e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org 694755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // If the source and destination are both to the same alloca, then this is 695755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // a noop copy-to-self, just delete it. Otherwise, emit a load and store 6963811b436bf328d2ace6fe79ce99aeda71f9f06d3ager@chromium.org // as appropriate. 6973811b436bf328d2ace6fe79ce99aeda71f9f06d3ager@chromium.org AllocaInst *OrigAI = cast<AllocaInst>(GetUnderlyingObject(Ptr, &DL, 0)); 6983811b436bf328d2ace6fe79ce99aeda71f9f06d3ager@chromium.org 6993811b436bf328d2ace6fe79ce99aeda71f9f06d3ager@chromium.org if (GetUnderlyingObject(MTI->getSource(), &DL, 0) != OrigAI) { 700e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // Dest must be OrigAI, change this to be a load from the original 701e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // pointer (bitcasted), then a store to our new alloca. 702e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org assert(MTI->getRawDest() == Ptr && "Neither use is of pointer?"); 703eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org Value *SrcPtr = MTI->getSource(); 704e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org PointerType* SPTy = cast<PointerType>(SrcPtr->getType()); 705e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org PointerType* AIPTy = cast<PointerType>(NewAI->getType()); 706e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org if (SPTy->getAddressSpace() != AIPTy->getAddressSpace()) { 707911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org AIPTy = PointerType::get(AIPTy->getElementType(), 708911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org SPTy->getAddressSpace()); 709911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org } 710755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org SrcPtr = Builder.CreateBitCast(SrcPtr, AIPTy); 711911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org 712e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org LoadInst *SrcVal = Builder.CreateLoad(SrcPtr, "srcval"); 713e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org SrcVal->setAlignment(MTI->getAlignment()); 714911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org Builder.CreateStore(SrcVal, NewAI); 715911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org } else if (GetUnderlyingObject(MTI->getDest(), &DL, 0) != OrigAI) { 716911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org // Src must be OrigAI, change this to be a load from NewAI then a store 717e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // through the original dest pointer (bitcasted). 718eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org assert(MTI->getRawSource() == Ptr && "Neither use is of pointer?"); 719eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org LoadInst *SrcVal = Builder.CreateLoad(NewAI, "srcval"); 720badaffc570baec00166b0ad3bdc96995751a7e13ricow@chromium.org 721755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org PointerType* DPTy = cast<PointerType>(MTI->getDest()->getType()); 722755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org PointerType* AIPTy = cast<PointerType>(NewAI->getType()); 723755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org if (DPTy->getAddressSpace() != AIPTy->getAddressSpace()) { 724755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org AIPTy = PointerType::get(AIPTy->getElementType(), 725e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org DPTy->getAddressSpace()); 726e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org } 727755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org Value *DstPtr = Builder.CreateBitCast(MTI->getDest(), AIPTy); 728755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org 7293811b436bf328d2ace6fe79ce99aeda71f9f06d3ager@chromium.org StoreInst *NewStore = Builder.CreateStore(SrcVal, DstPtr); 7303811b436bf328d2ace6fe79ce99aeda71f9f06d3ager@chromium.org NewStore->setAlignment(MTI->getAlignment()); 7315aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org } else { 7323e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org // Noop transfer. Src == Dst 7335aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org } 7345a6af92a1549c81fb61855518f43b712e4c0e469christian.plesner.hansen@gmail.com 7353811b436bf328d2ace6fe79ce99aeda71f9f06d3ager@chromium.org MTI->eraseFromParent(); 7365a6af92a1549c81fb61855518f43b712e4c0e469christian.plesner.hansen@gmail.com continue; 7375aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org } 738b302e56e5b70c4504faa2adf4ec3efb64a9d3e38sgjesse@chromium.org 739b302e56e5b70c4504faa2adf4ec3efb64a9d3e38sgjesse@chromium.org if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(User)) { 740b302e56e5b70c4504faa2adf4ec3efb64a9d3e38sgjesse@chromium.org if (II->getIntrinsicID() == Intrinsic::lifetime_start || 741b302e56e5b70c4504faa2adf4ec3efb64a9d3e38sgjesse@chromium.org II->getIntrinsicID() == Intrinsic::lifetime_end) { 742b302e56e5b70c4504faa2adf4ec3efb64a9d3e38sgjesse@chromium.org // There's no need to preserve these, as the resulting alloca will be 743b302e56e5b70c4504faa2adf4ec3efb64a9d3e38sgjesse@chromium.org // converted to a register anyways. 744b302e56e5b70c4504faa2adf4ec3efb64a9d3e38sgjesse@chromium.org II->eraseFromParent(); 745badaffc570baec00166b0ad3bdc96995751a7e13ricow@chromium.org continue; 746755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org } 747e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org } 7489085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 7493e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org llvm_unreachable("Unsupported operation!"); 7503e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org } 7513e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org} 7523e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org 7533e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org/// ConvertScalar_ExtractValue - Extract a value of type ToType from an integer 7549085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// or vector value FromVal, extracting the bits from the offset specified by 7559085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// Offset. This returns the value, which is of type ToType. 7569085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// 7579085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// This happens when we are converting an "integer union" to a single 7589085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// integer scalar, or when we are converting a "vector union" to a vector with 7595aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org/// insert/extractelement instructions. 7609dfbea4c7d423c7bc1db94425cb78e7f7cf41f78erik.corry@gmail.com/// 7615aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org/// Offset is an offset from the original alloca, in bits that need to be 7625aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org/// shifted to the right. 7633e87580939cb78c5802369f723680d4a16cc2902ager@chromium.orgValue *ConvertToScalarInfo:: 7643e87580939cb78c5802369f723680d4a16cc2902ager@chromium.orgConvertScalar_ExtractValue(Value *FromVal, Type *ToType, 7653e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org uint64_t Offset, Value* NonConstantIdx, 7663e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org IRBuilder<> &Builder) { 767e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org // If the load is of the whole new alloca, no conversion is needed. 768e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org Type *FromType = FromVal->getType(); 769e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org if (FromType == ToType && Offset == 0) 770e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org return FromVal; 77186f77b7fe492ed2bdfbf4e1147dab2f09c7d7003kasperl@chromium.org 77286f77b7fe492ed2bdfbf4e1147dab2f09c7d7003kasperl@chromium.org // If the result alloca is a vector type, this is either an element 77386f77b7fe492ed2bdfbf4e1147dab2f09c7d7003kasperl@chromium.org // access or a bitcast to another vector type of the same size. 77486f77b7fe492ed2bdfbf4e1147dab2f09c7d7003kasperl@chromium.org if (VectorType *VTy = dyn_cast<VectorType>(FromType)) { 775c3b670ff19220959730d7886892bc4beb95d2ebaerik.corry@gmail.com unsigned FromTypeSize = DL.getTypeAllocSize(FromType); 776c3b670ff19220959730d7886892bc4beb95d2ebaerik.corry@gmail.com unsigned ToTypeSize = DL.getTypeAllocSize(ToType); 777c3b670ff19220959730d7886892bc4beb95d2ebaerik.corry@gmail.com if (FromTypeSize == ToTypeSize) 778c3b670ff19220959730d7886892bc4beb95d2ebaerik.corry@gmail.com return Builder.CreateBitCast(FromVal, ToType); 779e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org 780755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // Otherwise it must be an element access. 781755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org unsigned Elt = 0; 782755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org if (Offset) { 783e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org unsigned EltSize = DL.getTypeAllocSizeInBits(VTy->getElementType()); 784e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org Elt = Offset/EltSize; 785e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org assert(EltSize*Elt == Offset && "Invalid modulus in validity checking"); 786755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org } 787eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org // Return the element extracted out of it. 788755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org Value *Idx; 789755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org if (NonConstantIdx) { 790755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org if (Elt) 791eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org Idx = Builder.CreateAdd(NonConstantIdx, 792755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org Builder.getInt32(Elt), 793755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org "dyn.offset"); 7949085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org else 795eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org Idx = NonConstantIdx; 796755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org } else 797755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org Idx = Builder.getInt32(Elt); 798755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org Value *V = Builder.CreateExtractElement(FromVal, Idx); 799dff694e8cc18aa9640e92962de2699b9d07a7690vegorov@chromium.org if (V->getType() != ToType) 8009dfbea4c7d423c7bc1db94425cb78e7f7cf41f78erik.corry@gmail.com V = Builder.CreateBitCast(V, ToType); 801dff694e8cc18aa9640e92962de2699b9d07a7690vegorov@chromium.org return V; 802dff694e8cc18aa9640e92962de2699b9d07a7690vegorov@chromium.org } 8030a4e901cdfb5505a896d30aa8c2e04fce0fbe069vegorov@chromium.org 8040a4e901cdfb5505a896d30aa8c2e04fce0fbe069vegorov@chromium.org // If ToType is a first class aggregate, extract out each of the pieces and 8050a4e901cdfb5505a896d30aa8c2e04fce0fbe069vegorov@chromium.org // use insertvalue's to form the FCA. 8060a4e901cdfb5505a896d30aa8c2e04fce0fbe069vegorov@chromium.org if (StructType *ST = dyn_cast<StructType>(ToType)) { 8073e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org assert(!NonConstantIdx && 8083e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org "Dynamic indexing into struct types not supported"); 8093e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org const StructLayout &Layout = *DL.getStructLayout(ST); 8103e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org Value *Res = UndefValue::get(ST); 811911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org for (unsigned i = 0, e = ST->getNumElements(); i != e; ++i) { 812911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org Value *Elt = ConvertScalar_ExtractValue(FromVal, ST->getElementType(i), 813911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org Offset+Layout.getElementOffsetInBits(i), 814911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org nullptr, Builder); 815911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org Res = Builder.CreateInsertValue(Res, Elt, i); 816911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org } 817911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org return Res; 818911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org } 819911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org 820911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org if (ArrayType *AT = dyn_cast<ArrayType>(ToType)) { 821911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org assert(!NonConstantIdx && 822911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org "Dynamic indexing into array types not supported"); 823911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org uint64_t EltSize = DL.getTypeAllocSizeInBits(AT->getElementType()); 824911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org Value *Res = UndefValue::get(AT); 825eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org for (unsigned i = 0, e = AT->getNumElements(); i != e; ++i) { 826eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org Value *Elt = ConvertScalar_ExtractValue(FromVal, AT->getElementType(), 827eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org Offset+i*EltSize, nullptr, 828eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org Builder); 829911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org Res = Builder.CreateInsertValue(Res, Elt, i); 830911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org } 831911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org return Res; 832911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org } 833911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org 834911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org // Otherwise, this must be a union that was converted to an integer value. 835911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org IntegerType *NTy = cast<IntegerType>(FromVal->getType()); 836911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org 837911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org // If this is a big-endian system and the load is narrower than the 838911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org // full alloca type, we need to do a shift to get the right bits. 839911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org int ShAmt = 0; 840911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org if (DL.isBigEndian()) { 841911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org // On big-endian machines, the lowest bit is stored at the bit offset 842911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org // from the pointer given by getTypeStoreSizeInBits. This matters for 843911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org // integers with a bitwidth that is not a multiple of 8. 844911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org ShAmt = DL.getTypeStoreSizeInBits(NTy) - 845911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org DL.getTypeStoreSizeInBits(ToType) - Offset; 846911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org } else { 847911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org ShAmt = Offset; 848911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org } 84968ac009f55a85e6891742d58914eaf717f667b26kasperl@chromium.org 85068ac009f55a85e6891742d58914eaf717f667b26kasperl@chromium.org // Note: we support negative bitwidths (with shl) which are not defined. 85168ac009f55a85e6891742d58914eaf717f667b26kasperl@chromium.org // We do this to support (f.e.) loads off the end of a structure where 85268ac009f55a85e6891742d58914eaf717f667b26kasperl@chromium.org // only some bits are used. 85368ac009f55a85e6891742d58914eaf717f667b26kasperl@chromium.org if (ShAmt > 0 && (unsigned)ShAmt < NTy->getBitWidth()) 854e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org FromVal = Builder.CreateLShr(FromVal, 85568ac009f55a85e6891742d58914eaf717f667b26kasperl@chromium.org ConstantInt::get(FromVal->getType(), ShAmt)); 85668ac009f55a85e6891742d58914eaf717f667b26kasperl@chromium.org else if (ShAmt < 0 && (unsigned)-ShAmt < NTy->getBitWidth()) 85768ac009f55a85e6891742d58914eaf717f667b26kasperl@chromium.org FromVal = Builder.CreateShl(FromVal, 858e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org ConstantInt::get(FromVal->getType(), -ShAmt)); 85968ac009f55a85e6891742d58914eaf717f667b26kasperl@chromium.org 86068ac009f55a85e6891742d58914eaf717f667b26kasperl@chromium.org // Finally, unconditionally truncate the integer to the right width. 86168ac009f55a85e6891742d58914eaf717f667b26kasperl@chromium.org unsigned LIBitWidth = DL.getTypeSizeInBits(ToType); 86268ac009f55a85e6891742d58914eaf717f667b26kasperl@chromium.org if (LIBitWidth < NTy->getBitWidth()) 86368ac009f55a85e6891742d58914eaf717f667b26kasperl@chromium.org FromVal = 86468ac009f55a85e6891742d58914eaf717f667b26kasperl@chromium.org Builder.CreateTrunc(FromVal, IntegerType::get(FromVal->getContext(), 86568ac009f55a85e6891742d58914eaf717f667b26kasperl@chromium.org LIBitWidth)); 86668ac009f55a85e6891742d58914eaf717f667b26kasperl@chromium.org else if (LIBitWidth > NTy->getBitWidth()) 86768ac009f55a85e6891742d58914eaf717f667b26kasperl@chromium.org FromVal = 86868ac009f55a85e6891742d58914eaf717f667b26kasperl@chromium.org Builder.CreateZExt(FromVal, IntegerType::get(FromVal->getContext(), 869eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org LIBitWidth)); 870755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org 871755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // If the result is an integer, this is a trunc or bitcast. 872755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org if (ToType->isIntegerTy()) { 873eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org // Should be done. 874755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org } else if (ToType->isFloatingPointTy() || ToType->isVectorTy()) { 875755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // Just do a bitcast, we know the sizes match up. 876755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org FromVal = Builder.CreateBitCast(FromVal, ToType); 877eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org } else { 878755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // Otherwise must be a pointer. 879755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org FromVal = Builder.CreateIntToPtr(FromVal, ToType); 8809085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 881eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org assert(FromVal->getType() == ToType && "Didn't convert right?"); 882755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org return FromVal; 883755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org} 884755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org 885eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org/// ConvertScalar_InsertValue - Insert the value "SV" into the existing integer 886755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// or vector value "Old" at the offset specified by Offset. 887755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// 888755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// This happens when we are converting an "integer union" to a 889755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// single integer scalar, or when we are converting a "vector union" to a 890755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// vector with insert/extractelement instructions. 891755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// 892755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// Offset is an offset from the original alloca, in bits that need to be 893755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// shifted to the right. 894755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// 895755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// NonConstantIdx is an index value if there was a GEP with a non-constant 896755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// index value. If this is 0 then all GEPs used to find this insert address 897755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// are constant. 898755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.orgValue *ConvertToScalarInfo:: 899755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.orgConvertScalar_InsertValue(Value *SV, Value *Old, 900755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org uint64_t Offset, Value* NonConstantIdx, 901755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org IRBuilder<> &Builder) { 902755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // Convert the stored type to the actual type, shift it left to insert 903755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // then 'or' into place. 904755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org Type *AllocaType = Old->getType(); 905755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org LLVMContext &Context = Old->getContext(); 906755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org 907755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org if (VectorType *VTy = dyn_cast<VectorType>(AllocaType)) { 9089085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org uint64_t VecSize = DL.getTypeAllocSizeInBits(VTy); 909c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org uint64_t ValSize = DL.getTypeAllocSizeInBits(SV->getType()); 910c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org 911c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org // Changing the whole vector with memset or with an access of a different 912c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org // vector type? 9139d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com if (ValSize == VecSize) 9149d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com return Builder.CreateBitCast(SV, AllocaType); 9159d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com 9169d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com // Must be an element insertion. 9170ee099beef2c2b38743d657b84a30b626d9178ecager@chromium.org Type *EltTy = VTy->getElementType(); 9180ee099beef2c2b38743d657b84a30b626d9178ecager@chromium.org if (SV->getType() != EltTy) 9190ee099beef2c2b38743d657b84a30b626d9178ecager@chromium.org SV = Builder.CreateBitCast(SV, EltTy); 9200ee099beef2c2b38743d657b84a30b626d9178ecager@chromium.org uint64_t EltSize = DL.getTypeAllocSizeInBits(EltTy); 921b302e56e5b70c4504faa2adf4ec3efb64a9d3e38sgjesse@chromium.org unsigned Elt = Offset/EltSize; 922b302e56e5b70c4504faa2adf4ec3efb64a9d3e38sgjesse@chromium.org Value *Idx; 923b302e56e5b70c4504faa2adf4ec3efb64a9d3e38sgjesse@chromium.org if (NonConstantIdx) { 9249d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com if (Elt) 925eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org Idx = Builder.CreateAdd(NonConstantIdx, 926eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org Builder.getInt32(Elt), 927e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org "dyn.offset"); 928eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org else 9299d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com Idx = NonConstantIdx; 9309d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com } else 9319085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Idx = Builder.getInt32(Elt); 932e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org return Builder.CreateInsertElement(Old, SV, Idx); 933e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org } 9340b6db5975a9d1ebcf3de7b18603380d99f789e66sgjesse@chromium.org 9350b6db5975a9d1ebcf3de7b18603380d99f789e66sgjesse@chromium.org // If SV is a first-class aggregate value, insert each value recursively. 9369085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (StructType *ST = dyn_cast<StructType>(SV->getType())) { 937e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org assert(!NonConstantIdx && 9380b6db5975a9d1ebcf3de7b18603380d99f789e66sgjesse@chromium.org "Dynamic indexing into struct types not supported"); 9390b6db5975a9d1ebcf3de7b18603380d99f789e66sgjesse@chromium.org const StructLayout &Layout = *DL.getStructLayout(ST); 9400b6db5975a9d1ebcf3de7b18603380d99f789e66sgjesse@chromium.org for (unsigned i = 0, e = ST->getNumElements(); i != e; ++i) { 9419085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Value *Elt = Builder.CreateExtractValue(SV, i); 9422abc450936e88b5c98a5e9d43ee6230ccc748272kasperl@chromium.org Old = ConvertScalar_InsertValue(Elt, Old, 9432abc450936e88b5c98a5e9d43ee6230ccc748272kasperl@chromium.org Offset+Layout.getElementOffsetInBits(i), 9442abc450936e88b5c98a5e9d43ee6230ccc748272kasperl@chromium.org nullptr, Builder); 9452abc450936e88b5c98a5e9d43ee6230ccc748272kasperl@chromium.org } 9462abc450936e88b5c98a5e9d43ee6230ccc748272kasperl@chromium.org return Old; 947cec079d8ed1f0920a0ea3dc9a3e81966013287c1whesse@chromium.org } 948cec079d8ed1f0920a0ea3dc9a3e81966013287c1whesse@chromium.org 949d91075f76b836c2cfa4f4e4cc0fb31170df864ccerik.corry@gmail.com if (ArrayType *AT = dyn_cast<ArrayType>(SV->getType())) { 950cec079d8ed1f0920a0ea3dc9a3e81966013287c1whesse@chromium.org assert(!NonConstantIdx && 9519085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org "Dynamic indexing into array types not supported"); 952eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org uint64_t EltSize = DL.getTypeAllocSizeInBits(AT->getElementType()); 953eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org for (unsigned i = 0, e = AT->getNumElements(); i != e; ++i) { 9545ad5acef6bd4ebc785f946d8bcc2a88b1e031827ricow@chromium.org Value *Elt = Builder.CreateExtractValue(SV, i); 955eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org Old = ConvertScalar_InsertValue(Elt, Old, Offset+i*EltSize, nullptr, 9569085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Builder); 9579085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 958cec079d8ed1f0920a0ea3dc9a3e81966013287c1whesse@chromium.org return Old; 9599085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 960e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org 9619085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // If SV is a float, convert it to the appropriate integer type. 9629085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // If it is a pointer, do the same. 9639085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org unsigned SrcWidth = DL.getTypeSizeInBits(SV->getType()); 964755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org unsigned DestWidth = DL.getTypeSizeInBits(AllocaType); 9654af710e493dc8583f3b7b7ce65127ad4e7c3f8a1ager@chromium.org unsigned SrcStoreWidth = DL.getTypeStoreSizeInBits(SV->getType()); 9669085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org unsigned DestStoreWidth = DL.getTypeStoreSizeInBits(AllocaType); 9679085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (SV->getType()->isFloatingPointTy() || SV->getType()->isVectorTy()) 968755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org SV = Builder.CreateBitCast(SV, IntegerType::get(SV->getContext(),SrcWidth)); 969cec079d8ed1f0920a0ea3dc9a3e81966013287c1whesse@chromium.org else if (SV->getType()->isPointerTy()) 970755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org SV = Builder.CreatePtrToInt(SV, DL.getIntPtrType(SV->getType())); 971755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org 972755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // Zero extend or truncate the value if needed. 973755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org if (SV->getType() != AllocaType) { 974755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org if (SV->getType()->getPrimitiveSizeInBits() < 9754af710e493dc8583f3b7b7ce65127ad4e7c3f8a1ager@chromium.org AllocaType->getPrimitiveSizeInBits()) 9764af710e493dc8583f3b7b7ce65127ad4e7c3f8a1ager@chromium.org SV = Builder.CreateZExt(SV, AllocaType); 9774af710e493dc8583f3b7b7ce65127ad4e7c3f8a1ager@chromium.org else { 9784af710e493dc8583f3b7b7ce65127ad4e7c3f8a1ager@chromium.org // Truncation may be needed if storing more than the alloca can hold 979755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // (undefined behavior). 980755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org SV = Builder.CreateTrunc(SV, AllocaType); 981755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org SrcWidth = DestWidth; 982755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org SrcStoreWidth = DestStoreWidth; 98383aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org } 98483aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org } 98583aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org 98683aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org // If this is a big-endian system and the store is narrower than the 987755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // full alloca type, we need to do a shift to get the right bits. 988755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org int ShAmt = 0; 989755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org if (DL.isBigEndian()) { 990755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // On big-endian machines, the lowest bit is stored at the bit offset 991755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // from the pointer given by getTypeStoreSizeInBits. This matters for 992755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // integers with a bitwidth that is not a multiple of 8. 993755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org ShAmt = DestStoreWidth - SrcStoreWidth - Offset; 994755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org } else { 9959d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com ShAmt = Offset; 9969d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com } 9979d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com 9989d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com // Note: we support negative bitwidths (with shr) which are not defined. 999755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // We do this to support (f.e.) stores off the end of a structure where 1000755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // only some bits in the structure are set. 1001755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org APInt Mask(APInt::getLowBitsSet(DestWidth, SrcWidth)); 10029085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (ShAmt > 0 && (unsigned)ShAmt < DestWidth) { 10039d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com SV = Builder.CreateShl(SV, ConstantInt::get(SV->getType(), ShAmt)); 10049d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com Mask <<= ShAmt; 10059d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com } else if (ShAmt < 0 && (unsigned)-ShAmt < DestWidth) { 10069d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com SV = Builder.CreateLShr(SV, ConstantInt::get(SV->getType(), -ShAmt)); 10079085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Mask = Mask.lshr(-ShAmt); 10089d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com } 10099d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com 10109d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com // Mask out the bits we are about to insert from the old value, and or 10119d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com // in the new bits. 10129d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com if (SrcWidth != DestWidth) { 10139d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com assert(DestWidth > SrcWidth); 10149d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com Old = Builder.CreateAnd(Old, ConstantInt::get(Context, ~Mask), "mask"); 10159d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com SV = Builder.CreateOr(Old, SV, "ins"); 10169d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com } 10179d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com return SV; 10189d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com} 10199d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com 10209d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com 10219d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com//===----------------------------------------------------------------------===// 10229d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com// SRoA Driver 10239085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org//===----------------------------------------------------------------------===// 1024e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org 1025e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org 1026e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.orgbool SROA::runOnFunction(Function &F) { 1027e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org if (skipOptnoneFunction(F)) 1028e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org return false; 1029e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org 1030e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>(); 1031e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org DL = DLP ? &DLP->getDataLayout() : nullptr; 1032e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org 1033e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org bool Changed = performPromotion(F); 1034e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org 1035e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // FIXME: ScalarRepl currently depends on DataLayout more than it 1036defbd109bb9bd556bb8ece103c3b340d3552155ekasperl@chromium.org // theoretically needs to. It should be refactored in order to support 1037defbd109bb9bd556bb8ece103c3b340d3552155ekasperl@chromium.org // target-independent IR. Until this is done, just skip the actual 1038defbd109bb9bd556bb8ece103c3b340d3552155ekasperl@chromium.org // scalar-replacement portion of this pass. 1039defbd109bb9bd556bb8ece103c3b340d3552155ekasperl@chromium.org if (!DL) return Changed; 1040defbd109bb9bd556bb8ece103c3b340d3552155ekasperl@chromium.org 1041defbd109bb9bd556bb8ece103c3b340d3552155ekasperl@chromium.org while (1) { 1042e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org bool LocalChange = performScalarRepl(F); 1043c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org if (!LocalChange) break; // No need to repromote if no scalarrepl 1044e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org Changed = true; 1045e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org LocalChange = performPromotion(F); 10469085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (!LocalChange) break; // No need to re-scalarrepl if no promotion 1047defbd109bb9bd556bb8ece103c3b340d3552155ekasperl@chromium.org } 1048c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org 1049defbd109bb9bd556bb8ece103c3b340d3552155ekasperl@chromium.org return Changed; 1050defbd109bb9bd556bb8ece103c3b340d3552155ekasperl@chromium.org} 1051defbd109bb9bd556bb8ece103c3b340d3552155ekasperl@chromium.org 1052e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.orgnamespace { 1053e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.orgclass AllocaPromoter : public LoadAndStorePromoter { 1054e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org AllocaInst *AI; 10559085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org DIBuilder *DIB; 1056c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org SmallVector<DbgDeclareInst *, 4> DDIs; 1057e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org SmallVector<DbgValueInst *, 4> DVIs; 1058e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.orgpublic: 10599085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org AllocaPromoter(const SmallVectorImpl<Instruction*> &Insts, SSAUpdater &S, 1060c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org DIBuilder *DB) 10615aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org : LoadAndStorePromoter(Insts, S), AI(nullptr), DIB(DB) {} 10625aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org 10635aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org void run(AllocaInst *AI, const SmallVectorImpl<Instruction*> &Insts) { 1064e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org // Remember which alloca we're promoting (for isInstInList). 1065e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org this->AI = AI; 1066e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org if (MDNode *DebugNode = MDNode::getIfExists(AI->getContext(), AI)) { 1067e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org for (User *U : DebugNode->users()) 1068e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(U)) 1069e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org DDIs.push_back(DDI); 1070e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org else if (DbgValueInst *DVI = dyn_cast<DbgValueInst>(U)) 10719085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org DVIs.push_back(DVI); 1072c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org } 1073e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org 1074e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org LoadAndStorePromoter::run(Insts); 10759085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org AI->eraseFromParent(); 1076c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org for (SmallVectorImpl<DbgDeclareInst *>::iterator I = DDIs.begin(), 10775aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org E = DDIs.end(); I != E; ++I) { 10785aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org DbgDeclareInst *DDI = *I; 10795aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org DDI->eraseFromParent(); 1080e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org } 1081e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org for (SmallVectorImpl<DbgValueInst *>::iterator I = DVIs.begin(), 1082e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org E = DVIs.end(); I != E; ++I) { 1083e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org DbgValueInst *DVI = *I; 1084e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org DVI->eraseFromParent(); 1085e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org } 10869085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 1087eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org 1088755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org bool isInstInList(Instruction *I, 1089755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org const SmallVectorImpl<Instruction*> &Insts) const override { 1090755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org if (LoadInst *LI = dyn_cast<LoadInst>(I)) 1091eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org return LI->getOperand(0) == AI; 1092755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org return cast<StoreInst>(I)->getPointerOperand() == AI; 1093755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org } 1094755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org 1095eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org void updateDebugInfo(Instruction *Inst) const override { 1096755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org for (SmallVectorImpl<DbgDeclareInst *>::const_iterator I = DDIs.begin(), 1097755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org E = DDIs.end(); I != E; ++I) { 10989085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org DbgDeclareInst *DDI = *I; 1099eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) 1100755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org ConvertDebugDeclareToDebugValue(DDI, SI, *DIB); 1101755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org else if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) 1102755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org ConvertDebugDeclareToDebugValue(DDI, LI, *DIB); 1103eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org } 1104755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org for (SmallVectorImpl<DbgValueInst *>::const_iterator I = DVIs.begin(), 1105755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org E = DVIs.end(); I != E; ++I) { 1106755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org DbgValueInst *DVI = *I; 11075aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org Value *Arg = nullptr; 11085aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) { 11095aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org // If an argument is zero extended then use argument directly. The ZExt 11105aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org // may be zapped by an optimization pass in future. 1111b302e56e5b70c4504faa2adf4ec3efb64a9d3e38sgjesse@chromium.org if (ZExtInst *ZExt = dyn_cast<ZExtInst>(SI->getOperand(0))) 1112b302e56e5b70c4504faa2adf4ec3efb64a9d3e38sgjesse@chromium.org Arg = dyn_cast<Argument>(ZExt->getOperand(0)); 1113b302e56e5b70c4504faa2adf4ec3efb64a9d3e38sgjesse@chromium.org if (SExtInst *SExt = dyn_cast<SExtInst>(SI->getOperand(0))) 1114b302e56e5b70c4504faa2adf4ec3efb64a9d3e38sgjesse@chromium.org Arg = dyn_cast<Argument>(SExt->getOperand(0)); 1115eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org if (!Arg) 1116eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org Arg = SI->getOperand(0); 1117eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org } else if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) { 1118eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org Arg = LI->getOperand(0); 111986f77b7fe492ed2bdfbf4e1147dab2f09c7d7003kasperl@chromium.org } else { 112086f77b7fe492ed2bdfbf4e1147dab2f09c7d7003kasperl@chromium.org continue; 112186f77b7fe492ed2bdfbf4e1147dab2f09c7d7003kasperl@chromium.org } 112286f77b7fe492ed2bdfbf4e1147dab2f09c7d7003kasperl@chromium.org Instruction *DbgVal = 1123911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org DIB->insertDbgValueIntrinsic(Arg, 0, DIVariable(DVI->getVariable()), 1124911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org Inst); 1125911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org DbgVal->setDebugLoc(DVI->getDebugLoc()); 1126911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org } 11279d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com } 1128755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org}; 1129755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org} // end anon namespace 1130b302e56e5b70c4504faa2adf4ec3efb64a9d3e38sgjesse@chromium.org 113168ac009f55a85e6891742d58914eaf717f667b26kasperl@chromium.org/// isSafeSelectToSpeculate - Select instructions that use an alloca and are 1132755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// subsequently loaded can be rewritten to load both input pointers and then 1133755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// select between the result, allowing the load of the alloca to be promoted. 1134e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org/// From this: 1135e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org/// %P2 = select i1 %cond, i32* %Alloca, i32* %Other 1136eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org/// %V = load i32* %P2 1137755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// to: 1138755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// %V1 = load i32* %Alloca -> will be mem2reg'd 11393811b436bf328d2ace6fe79ce99aeda71f9f06d3ager@chromium.org/// %V2 = load i32* %Other 11403811b436bf328d2ace6fe79ce99aeda71f9f06d3ager@chromium.org/// %V = select i1 %cond, i32 %V1, i32 %V2 11413811b436bf328d2ace6fe79ce99aeda71f9f06d3ager@chromium.org/// 11423811b436bf328d2ace6fe79ce99aeda71f9f06d3ager@chromium.org/// We can do this to a select if its only uses are loads and if the operand to 11433811b436bf328d2ace6fe79ce99aeda71f9f06d3ager@chromium.org/// the select can be loaded unconditionally. 1144755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.orgstatic bool isSafeSelectToSpeculate(SelectInst *SI, const DataLayout *DL) { 1145755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org bool TDerefable = SI->getTrueValue()->isDereferenceablePointer(); 11464af710e493dc8583f3b7b7ce65127ad4e7c3f8a1ager@chromium.org bool FDerefable = SI->getFalseValue()->isDereferenceablePointer(); 11474af710e493dc8583f3b7b7ce65127ad4e7c3f8a1ager@chromium.org 11484af710e493dc8583f3b7b7ce65127ad4e7c3f8a1ager@chromium.org for (User *U : SI->users()) { 11494af710e493dc8583f3b7b7ce65127ad4e7c3f8a1ager@chromium.org LoadInst *LI = dyn_cast<LoadInst>(U); 115083aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org if (!LI || !LI->isSimple()) return false; 115183aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org 115283aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org // Both operands to the select need to be dereferencable, either absolutely 115383aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org // (e.g. allocas) or at this point because we can see other accesses to it. 115483aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org if (!TDerefable && !isSafeToLoadUnconditionally(SI->getTrueValue(), LI, 115583aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org LI->getAlignment(), DL)) 115683aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org return false; 115783aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org if (!FDerefable && !isSafeToLoadUnconditionally(SI->getFalseValue(), LI, 115883aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org LI->getAlignment(), DL)) 115983aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org return false; 116083aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org } 116183aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org 1162755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org return true; 1163755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org} 1164755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org 1165755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// isSafePHIToSpeculate - PHI instructions that use an alloca and are 1166755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// subsequently loaded can be rewritten to load both input pointers in the pred 1167755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// blocks and then PHI the results, allowing the load of the alloca to be 1168755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// promoted. 1169755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// From this: 1170755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// %P2 = phi [i32* %Alloca, i32* %Other] 1171755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// %V = load i32* %P2 1172755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// to: 1173755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// %V1 = load i32* %Alloca -> will be mem2reg'd 1174755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// ... 1175755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// %V2 = load i32* %Other 1176755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org/// ... 11779085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// %V = phi [i32 %V1, i32 %V2] 11789085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// 11799085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// We can do this to a select if its only uses are loads and if the operand to 11809085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// the select can be loaded unconditionally. 11819085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.orgstatic bool isSafePHIToSpeculate(PHINode *PN, const DataLayout *DL) { 11829085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // For now, we can only do this promotion if the load is in the same block as 11839d58c2b1c27d8b2890b9bd46e57d3842b09e0292christian.plesner.hansen@gmail.com // the PHI, and if there are no stores between the phi and load. 11847979bbb1df2eaff193e85d44c8da1ffa1525b7fcfschneider@chromium.org // TODO: Allow recursive phi users. 1185eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org // TODO: Allow stores. 11869085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org BasicBlock *BB = PN->getParent(); 11879085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org unsigned MaxAlign = 0; 11889085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org for (User *U : PN->users()) { 11899085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org LoadInst *LI = dyn_cast<LoadInst>(U); 11909085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (!LI || !LI->isSimple()) return false; 1191eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org 11929085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // For now we only allow loads in the same block as the PHI. This is a 11939085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // common case that happens when instcombine merges two loads through a PHI. 11949085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (LI->getParent() != BB) return false; 11959085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 11969085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // Ensure that there are no instructions between the PHI and the load that 11979085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // could store. 11989085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org for (BasicBlock::iterator BBI = PN; &*BBI != LI; ++BBI) 11999085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (BBI->mayWriteToMemory()) 12009085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return false; 12019085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 12029085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org MaxAlign = std::max(MaxAlign, LI->getAlignment()); 12039085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 12049085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 12059085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // Okay, we know that we have one or more loads in the same block as the PHI. 12069085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // We can transform this if it is safe to push the loads into the predecessor 12079085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // blocks. The only thing to watch out for is that we can't put a possibly 12089085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // trapping load in the predecessor if it is a critical edge. 12099085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { 12109085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org BasicBlock *Pred = PN->getIncomingBlock(i); 1211e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org Value *InVal = PN->getIncomingValue(i); 12129085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 12138e8294a88dc7d58f579aee0ba08c19fc8a616e2dsgjesse@chromium.org // If the terminator of the predecessor has side-effects (an invoke), 12144f693d6b99ffdbc05e5e211e08ed5039e13279d2ricow@chromium.org // there is no safe place to put a load in the predecessor. 1215471f2f1d24adb4bad1edc3bf0ee35092486de187mstarzinger@chromium.org if (Pred->getTerminator()->mayHaveSideEffects()) 1216e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org return false; 121783aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org 121883aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org // If the value is produced by the terminator of the predecessor 121983aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org // (an invoke), there is no valid place to put a load in the predecessor. 122083aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org if (Pred->getTerminator() == InVal) 122183aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org return false; 122283aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org 1223e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // If the predecessor has a single successor, then the edge isn't critical. 1224e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org if (Pred->getTerminator()->getNumSuccessors() == 1) 1225e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org continue; 1226e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org 1227e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // If this pointer is always safe to load, or if we can prove that there is 12289085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // already a load in the block, then we can move the load to the pred block. 12299085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (InVal->isDereferenceablePointer() || 1230e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org isSafeToLoadUnconditionally(InVal, Pred->getTerminator(), MaxAlign, DL)) 1231c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org continue; 123283a4728861129dc263ded92157f3e6389f851f19karlklose@chromium.org 123383a4728861129dc263ded92157f3e6389f851f19karlklose@chromium.org return false; 1234c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org } 1235e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org 1236e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org return true; 1237e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org} 12389085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 1239911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org 1240911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org/// tryToMakeAllocaBePromotable - This returns true if the alloca only has 1241911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org/// direct (non-volatile) loads and stores to it. If the alloca is close but 12429085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// not quite there, this will transform the code to allow promotion. As such, 124383a4728861129dc263ded92157f3e6389f851f19karlklose@chromium.org/// it is a non-pure predicate. 124483a4728861129dc263ded92157f3e6389f851f19karlklose@chromium.orgstatic bool tryToMakeAllocaBePromotable(AllocaInst *AI, const DataLayout *DL) { 124583a4728861129dc263ded92157f3e6389f851f19karlklose@chromium.org SetVector<Instruction*, SmallVector<Instruction*, 4>, 1246c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org SmallPtrSet<Instruction*, 4> > InstsToRewrite; 12479085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org for (User *U : AI->users()) { 12489085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (LoadInst *LI = dyn_cast<LoadInst>(U)) { 12499085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (!LI->isSimple()) 12509085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return false; 12519085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org continue; 12529085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 1253ac091b7d178f1853ede4a5cba58e767e6adf7d96ager@chromium.org 1254a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org if (StoreInst *SI = dyn_cast<StoreInst>(U)) { 12559085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (SI->getOperand(0) == AI || !SI->isSimple()) 12569085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return false; // Don't allow a store OF the AI, only INTO the AI. 12579085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org continue; 12589085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 12599085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 12609085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (SelectInst *SI = dyn_cast<SelectInst>(U)) { 12613811b436bf328d2ace6fe79ce99aeda71f9f06d3ager@chromium.org // If the condition being selected on is a constant, fold the select, yes 12629085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // this does (rarely) happen early on. 12639085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (ConstantInt *CI = dyn_cast<ConstantInt>(SI->getCondition())) { 12649085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Value *Result = SI->getOperand(1+CI->isZero()); 12659085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org SI->replaceAllUsesWith(Result); 12669085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org SI->eraseFromParent(); 12679085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 12689085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // This is very rare and we just scrambled the use list of AI, start 12699085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // over completely. 12709085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return tryToMakeAllocaBePromotable(AI, DL); 12719085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 1272b302e56e5b70c4504faa2adf4ec3efb64a9d3e38sgjesse@chromium.org 12739085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // If it is safe to turn "load (select c, AI, ptr)" into a select of two 12749085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // loads, then we can transform this by rewriting the select. 12759085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (!isSafeSelectToSpeculate(SI, DL)) 12769085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return false; 12779085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 12789085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org InstsToRewrite.insert(SI); 12799085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org continue; 12809085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 12819085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 12829085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (PHINode *PN = dyn_cast<PHINode>(U)) { 12839085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (PN->use_empty()) { // Dead PHIs can be stripped. 12849085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org InstsToRewrite.insert(PN); 12859085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org continue; 12869085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 12879085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 12889085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // If it is safe to turn "load (phi [AI, ptr, ...])" into a PHI of loads 12899085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // in the pred blocks, then we can transform this by rewriting the PHI. 12909085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (!isSafePHIToSpeculate(PN, DL)) 12919085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return false; 12929085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 12939085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org InstsToRewrite.insert(PN); 12949085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org continue; 12959085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 12969085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 12979085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (BitCastInst *BCI = dyn_cast<BitCastInst>(U)) { 12989085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (onlyUsedByLifetimeMarkers(BCI)) { 12993811b436bf328d2ace6fe79ce99aeda71f9f06d3ager@chromium.org InstsToRewrite.insert(BCI); 13003811b436bf328d2ace6fe79ce99aeda71f9f06d3ager@chromium.org continue; 13013811b436bf328d2ace6fe79ce99aeda71f9f06d3ager@chromium.org } 13029085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 13039085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 13049085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return false; 13059085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 13069085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 13075aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org // If there are no instructions to rewrite, then all uses are load/stores and 13085aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org // we're done! 13091b3afd1cab9087ca3c4e585d3da77d374d65c082mstarzinger@chromium.org if (InstsToRewrite.empty()) 1310a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org return true; 131164e3a4be4a99f31920128de34573c8ac9038de42ricow@chromium.org 131264e3a4be4a99f31920128de34573c8ac9038de42ricow@chromium.org // If we have instructions that need to be rewritten for this to be promotable 131364e3a4be4a99f31920128de34573c8ac9038de42ricow@chromium.org // take care of it now. 13145aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org for (unsigned i = 0, e = InstsToRewrite.size(); i != e; ++i) { 13159085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (BitCastInst *BCI = dyn_cast<BitCastInst>(InstsToRewrite[i])) { 13169085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // This could only be a bitcast used by nothing but lifetime intrinsics. 13173e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org for (BitCastInst::user_iterator I = BCI->user_begin(), E = BCI->user_end(); 13183e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org I != E;) 13193e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org cast<Instruction>(*I++)->eraseFromParent(); 1320357bf65ed5309ac3a2c4bf20b6ce7770488787c2ager@chromium.org BCI->eraseFromParent(); 1321ac091b7d178f1853ede4a5cba58e767e6adf7d96ager@chromium.org continue; 1322ac091b7d178f1853ede4a5cba58e767e6adf7d96ager@chromium.org } 1323ac091b7d178f1853ede4a5cba58e767e6adf7d96ager@chromium.org 1324160a7b0747492f3f735353d9582521f3314bf4dfdanno@chromium.org if (SelectInst *SI = dyn_cast<SelectInst>(InstsToRewrite[i])) { 1325ac091b7d178f1853ede4a5cba58e767e6adf7d96ager@chromium.org // Selects in InstsToRewrite only have load uses. Rewrite each as two 1326357bf65ed5309ac3a2c4bf20b6ce7770488787c2ager@chromium.org // loads with a new select. 1327160a7b0747492f3f735353d9582521f3314bf4dfdanno@chromium.org while (!SI->use_empty()) { 1328160a7b0747492f3f735353d9582521f3314bf4dfdanno@chromium.org LoadInst *LI = cast<LoadInst>(SI->user_back()); 1329160a7b0747492f3f735353d9582521f3314bf4dfdanno@chromium.org 1330160a7b0747492f3f735353d9582521f3314bf4dfdanno@chromium.org IRBuilder<> Builder(LI); 1331357bf65ed5309ac3a2c4bf20b6ce7770488787c2ager@chromium.org LoadInst *TrueLoad = 1332160a7b0747492f3f735353d9582521f3314bf4dfdanno@chromium.org Builder.CreateLoad(SI->getTrueValue(), LI->getName()+".t"); 1333160a7b0747492f3f735353d9582521f3314bf4dfdanno@chromium.org LoadInst *FalseLoad = 1334357bf65ed5309ac3a2c4bf20b6ce7770488787c2ager@chromium.org Builder.CreateLoad(SI->getFalseValue(), LI->getName()+".f"); 13353e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org 13360ee099beef2c2b38743d657b84a30b626d9178ecager@chromium.org // Transfer alignment and TBAA info if present. 13370ee099beef2c2b38743d657b84a30b626d9178ecager@chromium.org TrueLoad->setAlignment(LI->getAlignment()); 13380ee099beef2c2b38743d657b84a30b626d9178ecager@chromium.org FalseLoad->setAlignment(LI->getAlignment()); 1339160a7b0747492f3f735353d9582521f3314bf4dfdanno@chromium.org if (MDNode *Tag = LI->getMetadata(LLVMContext::MD_tbaa)) { 1340160a7b0747492f3f735353d9582521f3314bf4dfdanno@chromium.org TrueLoad->setMetadata(LLVMContext::MD_tbaa, Tag); 1341160a7b0747492f3f735353d9582521f3314bf4dfdanno@chromium.org FalseLoad->setMetadata(LLVMContext::MD_tbaa, Tag); 134240b9da37a45dabf86bd82a39e885f2921f47fc08fschneider@chromium.org } 134340b9da37a45dabf86bd82a39e885f2921f47fc08fschneider@chromium.org 134440b9da37a45dabf86bd82a39e885f2921f47fc08fschneider@chromium.org Value *V = Builder.CreateSelect(SI->getCondition(), TrueLoad, FalseLoad); 13459085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org V->takeName(LI); 13460a4e901cdfb5505a896d30aa8c2e04fce0fbe069vegorov@chromium.org LI->replaceAllUsesWith(V); 13479085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org LI->eraseFromParent(); 13480a4e901cdfb5505a896d30aa8c2e04fce0fbe069vegorov@chromium.org } 1349dff694e8cc18aa9640e92962de2699b9d07a7690vegorov@chromium.org 13509085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // Now that all the loads are gone, the select is gone too. 13513e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org SI->eraseFromParent(); 13523e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org continue; 13533e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org } 13543e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org 13559085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // Otherwise, we have a PHI node which allows us to push the loads into the 135640b9da37a45dabf86bd82a39e885f2921f47fc08fschneider@chromium.org // predecessors. 135740b9da37a45dabf86bd82a39e885f2921f47fc08fschneider@chromium.org PHINode *PN = cast<PHINode>(InstsToRewrite[i]); 1358357bf65ed5309ac3a2c4bf20b6ce7770488787c2ager@chromium.org if (PN->use_empty()) { 135940b9da37a45dabf86bd82a39e885f2921f47fc08fschneider@chromium.org PN->eraseFromParent(); 136040b9da37a45dabf86bd82a39e885f2921f47fc08fschneider@chromium.org continue; 136140b9da37a45dabf86bd82a39e885f2921f47fc08fschneider@chromium.org } 136240b9da37a45dabf86bd82a39e885f2921f47fc08fschneider@chromium.org 136340b9da37a45dabf86bd82a39e885f2921f47fc08fschneider@chromium.org Type *LoadTy = cast<PointerType>(PN->getType())->getElementType(); 1364357bf65ed5309ac3a2c4bf20b6ce7770488787c2ager@chromium.org PHINode *NewPN = PHINode::Create(LoadTy, PN->getNumIncomingValues(), 13659085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org PN->getName()+".ld", PN); 13669085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 13679085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // Get the TBAA tag and alignment to use from one of the loads. It doesn't 13689085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // matter which one we get and if any differ, it doesn't matter. 13699085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org LoadInst *SomeLoad = cast<LoadInst>(PN->user_back()); 13705d6c1f5b20195b800bc6db146920fd6f878d1fd4vegorov@chromium.org MDNode *TBAATag = SomeLoad->getMetadata(LLVMContext::MD_tbaa); 13715d6c1f5b20195b800bc6db146920fd6f878d1fd4vegorov@chromium.org unsigned Align = SomeLoad->getAlignment(); 13725c838251403b0be9a882540f1922577abba4c872ager@chromium.org 1373160a7b0747492f3f735353d9582521f3314bf4dfdanno@chromium.org // Rewrite all loads of the PN to use the new PHI. 13744111b80e5083e1ec54273d3275875ccc24cdbbafkmillikin@chromium.org while (!PN->use_empty()) { 13755c838251403b0be9a882540f1922577abba4c872ager@chromium.org LoadInst *LI = cast<LoadInst>(PN->user_back()); 13765c838251403b0be9a882540f1922577abba4c872ager@chromium.org LI->replaceAllUsesWith(NewPN); 137740b9da37a45dabf86bd82a39e885f2921f47fc08fschneider@chromium.org LI->eraseFromParent(); 13783e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org } 1379160a7b0747492f3f735353d9582521f3314bf4dfdanno@chromium.org 1380160a7b0747492f3f735353d9582521f3314bf4dfdanno@chromium.org // Inject loads into all of the pred blocks. Keep track of which blocks we 1381160a7b0747492f3f735353d9582521f3314bf4dfdanno@chromium.org // insert them into in case we have multiple edges from the same block. 1382160a7b0747492f3f735353d9582521f3314bf4dfdanno@chromium.org DenseMap<BasicBlock*, LoadInst*> InsertedLoads; 1383160a7b0747492f3f735353d9582521f3314bf4dfdanno@chromium.org 1384160a7b0747492f3f735353d9582521f3314bf4dfdanno@chromium.org for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { 1385160a7b0747492f3f735353d9582521f3314bf4dfdanno@chromium.org BasicBlock *Pred = PN->getIncomingBlock(i); 1386160a7b0747492f3f735353d9582521f3314bf4dfdanno@chromium.org LoadInst *&Load = InsertedLoads[Pred]; 1387160a7b0747492f3f735353d9582521f3314bf4dfdanno@chromium.org if (!Load) { 138883aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org Load = new LoadInst(PN->getIncomingValue(i), 138983aa54905e559090bea7771b83f188762cfcf082ricow@chromium.org PN->getName() + "." + Pred->getName(), 1390357bf65ed5309ac3a2c4bf20b6ce7770488787c2ager@chromium.org Pred->getTerminator()); 13913e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org Load->setAlignment(Align); 13923e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org if (TBAATag) Load->setMetadata(LLVMContext::MD_tbaa, TBAATag); 13933e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org } 1394ac091b7d178f1853ede4a5cba58e767e6adf7d96ager@chromium.org 13953e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org NewPN->addIncoming(Load, Pred); 13969085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 13979085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 13989085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org PN->eraseFromParent(); 13999085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 14004f693d6b99ffdbc05e5e211e08ed5039e13279d2ricow@chromium.org 14014f693d6b99ffdbc05e5e211e08ed5039e13279d2ricow@chromium.org ++NumAdjusted; 14024f693d6b99ffdbc05e5e211e08ed5039e13279d2ricow@chromium.org return true; 14039085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org} 14049085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 14059085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.orgbool SROA::performPromotion(Function &F) { 14069085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org std::vector<AllocaInst*> Allocas; 14072356e6fbe66ac3aa027b61cb43a3c3619b3c3a5evegorov@chromium.org DominatorTree *DT = nullptr; 14082356e6fbe66ac3aa027b61cb43a3c3619b3c3a5evegorov@chromium.org if (HasDomTree) 14092356e6fbe66ac3aa027b61cb43a3c3619b3c3a5evegorov@chromium.org DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree(); 14109085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 1411a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org BasicBlock &BB = F.getEntryBlock(); // Get the entry node for the function 14123a5fd78f0ca6c2827bb05f69a373d152a9ce6ff3fschneider@chromium.org DIBuilder DIB(*F.getParent()); 14139085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org bool Changed = false; 1414a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org SmallVector<Instruction*, 64> Insts; 1415a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org while (1) { 14160511e24c6ebf94594a7e03bdcd58157ac2971d69erik.corry@gmail.com Allocas.clear(); 1417a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org 1418a55512615f5adc085d23bc8589d155c4b579fb7bkasperl@chromium.org // Find allocas that are safe to promote, by looking at all instructions in 14194a1fe7d5e92fdb673d5f05d5ddf7b1ed703ba18dwhesse@chromium.org // the entry node 1420f0ac72dfa39ec827de605aafc57d4834237aa7f3whesse@chromium.org for (BasicBlock::iterator I = BB.begin(), E = --BB.end(); I != E; ++I) 1421f0ac72dfa39ec827de605aafc57d4834237aa7f3whesse@chromium.org if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) // Is it an alloca? 14229085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (tryToMakeAllocaBePromotable(AI, DL)) 14239085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Allocas.push_back(AI); 14249085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 14259085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (Allocas.empty()) break; 14264af710e493dc8583f3b7b7ce65127ad4e7c3f8a1ager@chromium.org 14274af710e493dc8583f3b7b7ce65127ad4e7c3f8a1ager@chromium.org if (HasDomTree) 14284af710e493dc8583f3b7b7ce65127ad4e7c3f8a1ager@chromium.org PromoteMemToReg(Allocas, *DT); 14299085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org else { 14309085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org SSAUpdater SSA; 1431c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org for (unsigned i = 0, e = Allocas.size(); i != e; ++i) { 1432c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org AllocaInst *AI = Allocas[i]; 1433c4c927273ae2b690c4a015b4640a2a469c9a1a69ager@chromium.org 14349085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // Build list of instructions to promote. 143564e3a4be4a99f31920128de34573c8ac9038de42ricow@chromium.org for (User *U : AI->users()) 14362356e6fbe66ac3aa027b61cb43a3c3619b3c3a5evegorov@chromium.org Insts.push_back(cast<Instruction>(U)); 14379085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org AllocaPromoter(Insts, SSA, &DIB).run(AI, Insts); 14389085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Insts.clear(); 14399085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 14409085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 1441c3b670ff19220959730d7886892bc4beb95d2ebaerik.corry@gmail.com NumPromoted += Allocas.size(); 1442c3b670ff19220959730d7886892bc4beb95d2ebaerik.corry@gmail.com Changed = true; 1443c3b670ff19220959730d7886892bc4beb95d2ebaerik.corry@gmail.com } 1444badaffc570baec00166b0ad3bdc96995751a7e13ricow@chromium.org 1445badaffc570baec00166b0ad3bdc96995751a7e13ricow@chromium.org return Changed; 1446000f7fbc1dfa59e414332fd2898b5da4d44eedd6jkummerow@chromium.org} 1447badaffc570baec00166b0ad3bdc96995751a7e13ricow@chromium.org 14489085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 14499085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// ShouldAttemptScalarRepl - Decide if an alloca is a good candidate for 14509085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// SROA. It must be a struct or array type with a small number of elements. 14519085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.orgbool SROA::ShouldAttemptScalarRepl(AllocaInst *AI) { 14529085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Type *T = AI->getAllocatedType(); 14539085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // Do not promote any struct that has too many members. 14549085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (StructType *ST = dyn_cast<StructType>(T)) 14559085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return ST->getNumElements() <= StructMemberThreshold; 14569085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // Do not promote any array that has too many elements. 14579085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (ArrayType *AT = dyn_cast<ArrayType>(T)) 14589085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return AT->getNumElements() <= ArrayElementThreshold; 1459755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org return false; 1460755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org} 1461755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org 1462755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org// performScalarRepl - This algorithm is a simple worklist driven algorithm, 1463e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org// which runs on all of the alloca instructions in the entry block, removing 14648e8294a88dc7d58f579aee0ba08c19fc8a616e2dsgjesse@chromium.org// them if they are only used by getelementptr instructions. 14658e8294a88dc7d58f579aee0ba08c19fc8a616e2dsgjesse@chromium.org// 1466471f2f1d24adb4bad1edc3bf0ee35092486de187mstarzinger@chromium.orgbool SROA::performScalarRepl(Function &F) { 1467755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org std::vector<AllocaInst*> WorkList; 14689085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 146971affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org // Scan the entry basic block, adding allocas to the worklist. 147071affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org BasicBlock &BB = F.getEntryBlock(); 1471755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E; ++I) 1472755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org if (AllocaInst *A = dyn_cast<AllocaInst>(I)) 14733e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org WorkList.push_back(A); 1474ac091b7d178f1853ede4a5cba58e767e6adf7d96ager@chromium.org 1475ac091b7d178f1853ede4a5cba58e767e6adf7d96ager@chromium.org // Process the worklist 147671affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org bool Changed = false; 147771affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org while (!WorkList.empty()) { 147871affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org AllocaInst *AI = WorkList.back(); 1479755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org WorkList.pop_back(); 1480755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org 1481755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // Handle dead allocas trivially. These can be formed by SROA'ing arrays 148271affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org // with unused elements. 14833e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org if (AI->use_empty()) { 1484e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org AI->eraseFromParent(); 1485e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org Changed = true; 1486e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org continue; 1487e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org } 1488e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org 1489e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // If this alloca is impossible for us to promote, reject it early. 1490e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org if (AI->isArrayAllocation() || !AI->getAllocatedType()->isSized()) 1491e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org continue; 1492e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org 1493e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // Check to see if we can perform the core SROA transformation. We cannot 1494e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // transform the allocation instruction if it is an array allocation 1495e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // (allocations OF arrays are ok though), and an allocation of a scalar 1496e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // value cannot be decomposed at all. 1497e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org uint64_t AllocaSize = DL->getTypeAllocSize(AI->getAllocatedType()); 1498e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org 1499e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // Do not promote [0 x %struct]. 1500755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org if (AllocaSize == 0) continue; 1501755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org 1502e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // Do not promote any struct whose size is too big. 1503755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org if (AllocaSize > SRThreshold) continue; 1504755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org 1505755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // If the alloca looks like a good candidate for scalar replacement, and if 1506755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // all its users can be transformed, then split up the aggregate into its 1507755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // separate elements. 1508755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org if (ShouldAttemptScalarRepl(AI) && isSafeAllocaToScalarRepl(AI)) { 1509755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org DoScalarReplacement(AI, WorkList); 1510e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org Changed = true; 1511e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org continue; 1512e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org } 1513e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org 1514e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // If we can turn this aggregate value (potentially with casts) into a 1515e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // simple scalar value that can be mem2reg'd into a register value. 1516e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // IsNotTrivial tracks whether this is something that mem2reg could have 1517e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // promoted itself. If so, we don't want to transform it needlessly. Note 1518755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // that we can't just check based on the type: the alloca may be of an i32 1519755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // but that has pointer arithmetic to set byte 3 of it or something. 1520755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org if (AllocaInst *NewAI = ConvertToScalarInfo( 1521755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org (unsigned)AllocaSize, *DL, ScalarLoadThreshold).TryConvert(AI)) { 1522755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org NewAI->takeName(AI); 1523755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org AI->eraseFromParent(); 1524755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org ++NumConverted; 1525755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org Changed = true; 1526755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org continue; 1527755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org } 15283e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org 15293e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org // Otherwise, couldn't process this alloca. 15303e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org } 15313e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org 15323e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org return Changed; 1533ac091b7d178f1853ede4a5cba58e767e6adf7d96ager@chromium.org} 15343e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org 15353e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org/// DoScalarReplacement - This alloca satisfied the isSafeAllocaToScalarRepl 1536ac091b7d178f1853ede4a5cba58e767e6adf7d96ager@chromium.org/// predicate, do SROA now. 1537ac091b7d178f1853ede4a5cba58e767e6adf7d96ager@chromium.orgvoid SROA::DoScalarReplacement(AllocaInst *AI, 1538ac091b7d178f1853ede4a5cba58e767e6adf7d96ager@chromium.org std::vector<AllocaInst*> &WorkList) { 1539ac091b7d178f1853ede4a5cba58e767e6adf7d96ager@chromium.org DEBUG(dbgs() << "Found inst to SROA: " << *AI << '\n'); 15403e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org SmallVector<AllocaInst*, 32> ElementAllocas; 15413e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org if (StructType *ST = dyn_cast<StructType>(AI->getAllocatedType())) { 15423e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org ElementAllocas.reserve(ST->getNumContainedTypes()); 15433e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org for (unsigned i = 0, e = ST->getNumContainedTypes(); i != e; ++i) { 1544e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org AllocaInst *NA = new AllocaInst(ST->getContainedType(i), nullptr, 1545e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org AI->getAlignment(), 1546e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org AI->getName() + "." + Twine(i), AI); 1547e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org ElementAllocas.push_back(NA); 1548e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org WorkList.push_back(NA); // Add to worklist for recursive processing 1549e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org } 1550e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org } else { 1551e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org ArrayType *AT = cast<ArrayType>(AI->getAllocatedType()); 1552e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org ElementAllocas.reserve(AT->getNumElements()); 1553e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org Type *ElTy = AT->getElementType(); 1554755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org for (unsigned i = 0, e = AT->getNumElements(); i != e; ++i) { 1555755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org AllocaInst *NA = new AllocaInst(ElTy, nullptr, AI->getAlignment(), 1556e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org AI->getName() + "." + Twine(i), AI); 1557e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org ElementAllocas.push_back(NA); 15585aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org WorkList.push_back(NA); // Add to worklist for recursive processing 1559e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org } 1560e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org } 1561e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org 1562e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // Now that we have created the new alloca instructions, rewrite all the 1563e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // uses of the old alloca. 1564e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org RewriteForScalarRepl(AI, AI, 0, ElementAllocas); 1565e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org 1566e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org // Now erase any instructions that were made dead while rewriting the alloca. 1567e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org DeleteDeadInstructions(); 15685aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org AI->eraseFromParent(); 1569e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org 1570e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org ++NumReplaced; 1571e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org} 1572e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org 1573e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org/// DeleteDeadInstructions - Erase instructions on the DeadInstrs list, 15745aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org/// recursively including all their operands that become trivially dead. 15755aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.orgvoid SROA::DeleteDeadInstructions() { 1576755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org while (!DeadInsts.empty()) { 157771affb54842da76b24f0bb3184e9f0960523f89dkasperl@chromium.org Instruction *I = cast<Instruction>(DeadInsts.pop_back_val()); 15789085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 15799085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org for (User::op_iterator OI = I->op_begin(), E = I->op_end(); OI != E; ++OI) 15809085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (Instruction *U = dyn_cast<Instruction>(*OI)) { 1581755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // Zero out the operand and see if it becomes trivially dead. 1582755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // (But, don't add allocas to the dead instruction list -- they are 1583755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org // already on the worklist and will be deleted separately.) 1584e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org *OI = nullptr; 1585911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org if (isInstructionTriviallyDead(U) && !isa<AllocaInst>(U)) 1586911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org DeadInsts.push_back(U); 1587911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org } 1588e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org 1589911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org I->eraseFromParent(); 1590e959c18cf7193e2f021245584a3c8f1f32f82c92kasperl@chromium.org } 1591755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org} 1592755c5b1cc880bc54405d2652f934a941e8fcda4asgjesse@chromium.org 15933e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org/// isSafeForScalarRepl - Check if instruction I is a safe use with regard to 1594eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org/// performing scalar replacement of alloca AI. The results are flagged in 1595911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org/// the Info parameter. Offset indicates the position within AI that is 15963e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org/// referenced by this instruction. 15973e87580939cb78c5802369f723680d4a16cc2902ager@chromium.orgvoid SROA::isSafeForScalarRepl(Instruction *I, uint64_t Offset, 1598911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org AllocaInfo &Info) { 15993e87580939cb78c5802369f723680d4a16cc2902ager@chromium.org for (Use &U : I->uses()) { 1600911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org Instruction *User = cast<Instruction>(U.getUser()); 1601911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org 1602911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org if (BitCastInst *BC = dyn_cast<BitCastInst>(User)) { 1603911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org isSafeForScalarRepl(BC, Offset, Info); 1604911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org } else if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(User)) { 1605911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org uint64_t GEPOffset = Offset; 1606911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org isSafeGEP(GEPI, GEPOffset, Info); 1607911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org if (!Info.isUnsafe) 1608911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org isSafeForScalarRepl(GEPI, GEPOffset, Info); 1609911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org } else if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(User)) { 1610911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org ConstantInt *Length = dyn_cast<ConstantInt>(MI->getLength()); 1611911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org if (!Length || Length->isNegative()) 1612911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org return MarkUnsafe(Info, User); 1613911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org 1614911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org isSafeMemAccess(Offset, Length->getZExtValue(), nullptr, 1615e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org U.getOperandNo() == 0, Info, MI, 1616e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org true /*AllowWholeAccess*/); 1617defbd109bb9bd556bb8ece103c3b340d3552155ekasperl@chromium.org } else if (LoadInst *LI = dyn_cast<LoadInst>(User)) { 1618e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org if (!LI->isSimple()) 1619e2902be65446e26fd63a3b4eab2f14257cf4ebafager@chromium.org return MarkUnsafe(Info, User); 16205aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org Type *LIType = LI->getType(); 16219085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org isSafeMemAccess(Offset, DL->getTypeAllocSize(LIType), 16225aa501ca9fb4dfb30f4191aac135202fe8d80e4aager@chromium.org LIType, false, Info, LI, true /*AllowWholeAccess*/); 16239085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Info.hasALoadOrStore = true; 16249085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 1625eadaf2282ee421d7a63a21d71369b029105341ccager@chromium.org } else if (StoreInst *SI = dyn_cast<StoreInst>(User)) { 16269085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // Store is ok if storing INTO the pointer, not storing the pointer 16279085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (!SI->isSimple() || SI->getOperand(0) == I) 16289085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return MarkUnsafe(Info, User); 16299085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 16309085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Type *SIType = SI->getOperand(0)->getType(); 16319085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org isSafeMemAccess(Offset, DL->getTypeAllocSize(SIType), 16329085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org SIType, true, Info, SI, true /*AllowWholeAccess*/); 1633911335cff40a2630bbe1dfb77b1897be991241bfsgjesse@chromium.org Info.hasALoadOrStore = true; 16349085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(User)) { 16359085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (II->getIntrinsicID() != Intrinsic::lifetime_start && 16369085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org II->getIntrinsicID() != Intrinsic::lifetime_end) 16379085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return MarkUnsafe(Info, User); 16389085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } else if (isa<PHINode>(User) || isa<SelectInst>(User)) { 16399085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org isSafePHISelectUseForScalarRepl(User, Offset, Info); 16409085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } else { 16419085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return MarkUnsafe(Info, User); 16429085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 16439085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (Info.isUnsafe) return; 16449085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } 16459085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org} 1646c514574143c1bf74d4fb6e7dccb175fe9ff2f5d3sgjesse@chromium.org 16479085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 1648f0ac72dfa39ec827de605aafc57d4834237aa7f3whesse@chromium.org/// isSafePHIUseForScalarRepl - If we see a PHI node or select using a pointer 1649badaffc570baec00166b0ad3bdc96995751a7e13ricow@chromium.org/// derived from the alloca, we can often still split the alloca into elements. 1650badaffc570baec00166b0ad3bdc96995751a7e13ricow@chromium.org/// This is useful if we have a large alloca where one element is phi'd 1651000f7fbc1dfa59e414332fd2898b5da4d44eedd6jkummerow@chromium.org/// together somewhere: we can SRoA and promote all the other elements even if 1652badaffc570baec00166b0ad3bdc96995751a7e13ricow@chromium.org/// we end up not being able to promote this one. 1653f0ac72dfa39ec827de605aafc57d4834237aa7f3whesse@chromium.org/// 16549085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// All we require is that the uses of the PHI do not index into other parts of 16559085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// the alloca. The most important use case for this is single load and stores 16569085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org/// that are PHI'd together, which can happen due to code sinking. 16579085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.orgvoid SROA::isSafePHISelectUseForScalarRepl(Instruction *I, uint64_t Offset, 16589085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org AllocaInfo &Info) { 16599085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // If we've already checked this PHI, don't do it again. 16609085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (PHINode *PN = dyn_cast<PHINode>(I)) 16619085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (!Info.CheckedPHIs.insert(PN)) 16629085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return; 16639085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 16644af710e493dc8583f3b7b7ce65127ad4e7c3f8a1ager@chromium.org for (User *U : I->users()) { 16659085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Instruction *UI = cast<Instruction>(U); 16669085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 16679085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (BitCastInst *BC = dyn_cast<BitCastInst>(UI)) { 16689085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org isSafePHISelectUseForScalarRepl(BC, Offset, Info); 16699085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } else if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(UI)) { 16709085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // Only allow "bitcast" GEPs for simplicity. We could generalize this, 16719085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // but would have to prove that we're staying inside of an element being 16729085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org // promoted. 16739085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (!GEPI->hasAllZeroIndices()) 16749085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return MarkUnsafe(Info, UI); 16759085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org isSafePHISelectUseForScalarRepl(GEPI, Offset, Info); 16769085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } else if (LoadInst *LI = dyn_cast<LoadInst>(UI)) { 16779085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (!LI->isSimple()) 16789085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org return MarkUnsafe(Info, UI); 16799085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Type *LIType = LI->getType(); 16809085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org isSafeMemAccess(Offset, DL->getTypeAllocSize(LIType), 16819085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org LIType, false, Info, LI, false /*AllowWholeAccess*/); 16829085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org Info.hasALoadOrStore = true; 16839085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org 16849085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org } else if (StoreInst *SI = dyn_cast<StoreInst>(UI)) { 16855ec4892aef9cca42940d7d92302abf674365f6b7ager@chromium.org // Store is ok if storing INTO the pointer, not storing the pointer 16869085a016223a6b72bf580d5781c93ec7b9e54422ager@chromium.org if (!SI->isSimple() || SI->getOperand(0) == I) 1687 return MarkUnsafe(Info, UI); 1688 1689 Type *SIType = SI->getOperand(0)->getType(); 1690 isSafeMemAccess(Offset, DL->getTypeAllocSize(SIType), 1691 SIType, true, Info, SI, false /*AllowWholeAccess*/); 1692 Info.hasALoadOrStore = true; 1693 } else if (isa<PHINode>(UI) || isa<SelectInst>(UI)) { 1694 isSafePHISelectUseForScalarRepl(UI, Offset, Info); 1695 } else { 1696 return MarkUnsafe(Info, UI); 1697 } 1698 if (Info.isUnsafe) return; 1699 } 1700} 1701 1702/// isSafeGEP - Check if a GEP instruction can be handled for scalar 1703/// replacement. It is safe when all the indices are constant, in-bounds 1704/// references, and when the resulting offset corresponds to an element within 1705/// the alloca type. The results are flagged in the Info parameter. Upon 1706/// return, Offset is adjusted as specified by the GEP indices. 1707void SROA::isSafeGEP(GetElementPtrInst *GEPI, 1708 uint64_t &Offset, AllocaInfo &Info) { 1709 gep_type_iterator GEPIt = gep_type_begin(GEPI), E = gep_type_end(GEPI); 1710 if (GEPIt == E) 1711 return; 1712 bool NonConstant = false; 1713 unsigned NonConstantIdxSize = 0; 1714 1715 // Walk through the GEP type indices, checking the types that this indexes 1716 // into. 1717 for (; GEPIt != E; ++GEPIt) { 1718 // Ignore struct elements, no extra checking needed for these. 1719 if ((*GEPIt)->isStructTy()) 1720 continue; 1721 1722 ConstantInt *IdxVal = dyn_cast<ConstantInt>(GEPIt.getOperand()); 1723 if (!IdxVal) 1724 return MarkUnsafe(Info, GEPI); 1725 } 1726 1727 // Compute the offset due to this GEP and check if the alloca has a 1728 // component element at that offset. 1729 SmallVector<Value*, 8> Indices(GEPI->op_begin() + 1, GEPI->op_end()); 1730 // If this GEP is non-constant then the last operand must have been a 1731 // dynamic index into a vector. Pop this now as it has no impact on the 1732 // constant part of the offset. 1733 if (NonConstant) 1734 Indices.pop_back(); 1735 Offset += DL->getIndexedOffset(GEPI->getPointerOperandType(), Indices); 1736 if (!TypeHasComponent(Info.AI->getAllocatedType(), Offset, 1737 NonConstantIdxSize)) 1738 MarkUnsafe(Info, GEPI); 1739} 1740 1741/// isHomogeneousAggregate - Check if type T is a struct or array containing 1742/// elements of the same type (which is always true for arrays). If so, 1743/// return true with NumElts and EltTy set to the number of elements and the 1744/// element type, respectively. 1745static bool isHomogeneousAggregate(Type *T, unsigned &NumElts, 1746 Type *&EltTy) { 1747 if (ArrayType *AT = dyn_cast<ArrayType>(T)) { 1748 NumElts = AT->getNumElements(); 1749 EltTy = (NumElts == 0 ? nullptr : AT->getElementType()); 1750 return true; 1751 } 1752 if (StructType *ST = dyn_cast<StructType>(T)) { 1753 NumElts = ST->getNumContainedTypes(); 1754 EltTy = (NumElts == 0 ? nullptr : ST->getContainedType(0)); 1755 for (unsigned n = 1; n < NumElts; ++n) { 1756 if (ST->getContainedType(n) != EltTy) 1757 return false; 1758 } 1759 return true; 1760 } 1761 return false; 1762} 1763 1764/// isCompatibleAggregate - Check if T1 and T2 are either the same type or are 1765/// "homogeneous" aggregates with the same element type and number of elements. 1766static bool isCompatibleAggregate(Type *T1, Type *T2) { 1767 if (T1 == T2) 1768 return true; 1769 1770 unsigned NumElts1, NumElts2; 1771 Type *EltTy1, *EltTy2; 1772 if (isHomogeneousAggregate(T1, NumElts1, EltTy1) && 1773 isHomogeneousAggregate(T2, NumElts2, EltTy2) && 1774 NumElts1 == NumElts2 && 1775 EltTy1 == EltTy2) 1776 return true; 1777 1778 return false; 1779} 1780 1781/// isSafeMemAccess - Check if a load/store/memcpy operates on the entire AI 1782/// alloca or has an offset and size that corresponds to a component element 1783/// within it. The offset checked here may have been formed from a GEP with a 1784/// pointer bitcasted to a different type. 1785/// 1786/// If AllowWholeAccess is true, then this allows uses of the entire alloca as a 1787/// unit. If false, it only allows accesses known to be in a single element. 1788void SROA::isSafeMemAccess(uint64_t Offset, uint64_t MemSize, 1789 Type *MemOpType, bool isStore, 1790 AllocaInfo &Info, Instruction *TheAccess, 1791 bool AllowWholeAccess) { 1792 // Check if this is a load/store of the entire alloca. 1793 if (Offset == 0 && AllowWholeAccess && 1794 MemSize == DL->getTypeAllocSize(Info.AI->getAllocatedType())) { 1795 // This can be safe for MemIntrinsics (where MemOpType is 0) and integer 1796 // loads/stores (which are essentially the same as the MemIntrinsics with 1797 // regard to copying padding between elements). But, if an alloca is 1798 // flagged as both a source and destination of such operations, we'll need 1799 // to check later for padding between elements. 1800 if (!MemOpType || MemOpType->isIntegerTy()) { 1801 if (isStore) 1802 Info.isMemCpyDst = true; 1803 else 1804 Info.isMemCpySrc = true; 1805 return; 1806 } 1807 // This is also safe for references using a type that is compatible with 1808 // the type of the alloca, so that loads/stores can be rewritten using 1809 // insertvalue/extractvalue. 1810 if (isCompatibleAggregate(MemOpType, Info.AI->getAllocatedType())) { 1811 Info.hasSubelementAccess = true; 1812 return; 1813 } 1814 } 1815 // Check if the offset/size correspond to a component within the alloca type. 1816 Type *T = Info.AI->getAllocatedType(); 1817 if (TypeHasComponent(T, Offset, MemSize)) { 1818 Info.hasSubelementAccess = true; 1819 return; 1820 } 1821 1822 return MarkUnsafe(Info, TheAccess); 1823} 1824 1825/// TypeHasComponent - Return true if T has a component type with the 1826/// specified offset and size. If Size is zero, do not check the size. 1827bool SROA::TypeHasComponent(Type *T, uint64_t Offset, uint64_t Size) { 1828 Type *EltTy; 1829 uint64_t EltSize; 1830 if (StructType *ST = dyn_cast<StructType>(T)) { 1831 const StructLayout *Layout = DL->getStructLayout(ST); 1832 unsigned EltIdx = Layout->getElementContainingOffset(Offset); 1833 EltTy = ST->getContainedType(EltIdx); 1834 EltSize = DL->getTypeAllocSize(EltTy); 1835 Offset -= Layout->getElementOffset(EltIdx); 1836 } else if (ArrayType *AT = dyn_cast<ArrayType>(T)) { 1837 EltTy = AT->getElementType(); 1838 EltSize = DL->getTypeAllocSize(EltTy); 1839 if (Offset >= AT->getNumElements() * EltSize) 1840 return false; 1841 Offset %= EltSize; 1842 } else if (VectorType *VT = dyn_cast<VectorType>(T)) { 1843 EltTy = VT->getElementType(); 1844 EltSize = DL->getTypeAllocSize(EltTy); 1845 if (Offset >= VT->getNumElements() * EltSize) 1846 return false; 1847 Offset %= EltSize; 1848 } else { 1849 return false; 1850 } 1851 if (Offset == 0 && (Size == 0 || EltSize == Size)) 1852 return true; 1853 // Check if the component spans multiple elements. 1854 if (Offset + Size > EltSize) 1855 return false; 1856 return TypeHasComponent(EltTy, Offset, Size); 1857} 1858 1859/// RewriteForScalarRepl - Alloca AI is being split into NewElts, so rewrite 1860/// the instruction I, which references it, to use the separate elements. 1861/// Offset indicates the position within AI that is referenced by this 1862/// instruction. 1863void SROA::RewriteForScalarRepl(Instruction *I, AllocaInst *AI, uint64_t Offset, 1864 SmallVectorImpl<AllocaInst *> &NewElts) { 1865 for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI!=E;) { 1866 Use &TheUse = *UI++; 1867 Instruction *User = cast<Instruction>(TheUse.getUser()); 1868 1869 if (BitCastInst *BC = dyn_cast<BitCastInst>(User)) { 1870 RewriteBitCast(BC, AI, Offset, NewElts); 1871 continue; 1872 } 1873 1874 if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(User)) { 1875 RewriteGEP(GEPI, AI, Offset, NewElts); 1876 continue; 1877 } 1878 1879 if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(User)) { 1880 ConstantInt *Length = dyn_cast<ConstantInt>(MI->getLength()); 1881 uint64_t MemSize = Length->getZExtValue(); 1882 if (Offset == 0 && 1883 MemSize == DL->getTypeAllocSize(AI->getAllocatedType())) 1884 RewriteMemIntrinUserOfAlloca(MI, I, AI, NewElts); 1885 // Otherwise the intrinsic can only touch a single element and the 1886 // address operand will be updated, so nothing else needs to be done. 1887 continue; 1888 } 1889 1890 if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(User)) { 1891 if (II->getIntrinsicID() == Intrinsic::lifetime_start || 1892 II->getIntrinsicID() == Intrinsic::lifetime_end) { 1893 RewriteLifetimeIntrinsic(II, AI, Offset, NewElts); 1894 } 1895 continue; 1896 } 1897 1898 if (LoadInst *LI = dyn_cast<LoadInst>(User)) { 1899 Type *LIType = LI->getType(); 1900 1901 if (isCompatibleAggregate(LIType, AI->getAllocatedType())) { 1902 // Replace: 1903 // %res = load { i32, i32 }* %alloc 1904 // with: 1905 // %load.0 = load i32* %alloc.0 1906 // %insert.0 insertvalue { i32, i32 } zeroinitializer, i32 %load.0, 0 1907 // %load.1 = load i32* %alloc.1 1908 // %insert = insertvalue { i32, i32 } %insert.0, i32 %load.1, 1 1909 // (Also works for arrays instead of structs) 1910 Value *Insert = UndefValue::get(LIType); 1911 IRBuilder<> Builder(LI); 1912 for (unsigned i = 0, e = NewElts.size(); i != e; ++i) { 1913 Value *Load = Builder.CreateLoad(NewElts[i], "load"); 1914 Insert = Builder.CreateInsertValue(Insert, Load, i, "insert"); 1915 } 1916 LI->replaceAllUsesWith(Insert); 1917 DeadInsts.push_back(LI); 1918 } else if (LIType->isIntegerTy() && 1919 DL->getTypeAllocSize(LIType) == 1920 DL->getTypeAllocSize(AI->getAllocatedType())) { 1921 // If this is a load of the entire alloca to an integer, rewrite it. 1922 RewriteLoadUserOfWholeAlloca(LI, AI, NewElts); 1923 } 1924 continue; 1925 } 1926 1927 if (StoreInst *SI = dyn_cast<StoreInst>(User)) { 1928 Value *Val = SI->getOperand(0); 1929 Type *SIType = Val->getType(); 1930 if (isCompatibleAggregate(SIType, AI->getAllocatedType())) { 1931 // Replace: 1932 // store { i32, i32 } %val, { i32, i32 }* %alloc 1933 // with: 1934 // %val.0 = extractvalue { i32, i32 } %val, 0 1935 // store i32 %val.0, i32* %alloc.0 1936 // %val.1 = extractvalue { i32, i32 } %val, 1 1937 // store i32 %val.1, i32* %alloc.1 1938 // (Also works for arrays instead of structs) 1939 IRBuilder<> Builder(SI); 1940 for (unsigned i = 0, e = NewElts.size(); i != e; ++i) { 1941 Value *Extract = Builder.CreateExtractValue(Val, i, Val->getName()); 1942 Builder.CreateStore(Extract, NewElts[i]); 1943 } 1944 DeadInsts.push_back(SI); 1945 } else if (SIType->isIntegerTy() && 1946 DL->getTypeAllocSize(SIType) == 1947 DL->getTypeAllocSize(AI->getAllocatedType())) { 1948 // If this is a store of the entire alloca from an integer, rewrite it. 1949 RewriteStoreUserOfWholeAlloca(SI, AI, NewElts); 1950 } 1951 continue; 1952 } 1953 1954 if (isa<SelectInst>(User) || isa<PHINode>(User)) { 1955 // If we have a PHI user of the alloca itself (as opposed to a GEP or 1956 // bitcast) we have to rewrite it. GEP and bitcast uses will be RAUW'd to 1957 // the new pointer. 1958 if (!isa<AllocaInst>(I)) continue; 1959 1960 assert(Offset == 0 && NewElts[0] && 1961 "Direct alloca use should have a zero offset"); 1962 1963 // If we have a use of the alloca, we know the derived uses will be 1964 // utilizing just the first element of the scalarized result. Insert a 1965 // bitcast of the first alloca before the user as required. 1966 AllocaInst *NewAI = NewElts[0]; 1967 BitCastInst *BCI = new BitCastInst(NewAI, AI->getType(), "", NewAI); 1968 NewAI->moveBefore(BCI); 1969 TheUse = BCI; 1970 continue; 1971 } 1972 } 1973} 1974 1975/// RewriteBitCast - Update a bitcast reference to the alloca being replaced 1976/// and recursively continue updating all of its uses. 1977void SROA::RewriteBitCast(BitCastInst *BC, AllocaInst *AI, uint64_t Offset, 1978 SmallVectorImpl<AllocaInst *> &NewElts) { 1979 RewriteForScalarRepl(BC, AI, Offset, NewElts); 1980 if (BC->getOperand(0) != AI) 1981 return; 1982 1983 // The bitcast references the original alloca. Replace its uses with 1984 // references to the alloca containing offset zero (which is normally at 1985 // index zero, but might not be in cases involving structs with elements 1986 // of size zero). 1987 Type *T = AI->getAllocatedType(); 1988 uint64_t EltOffset = 0; 1989 Type *IdxTy; 1990 uint64_t Idx = FindElementAndOffset(T, EltOffset, IdxTy); 1991 Instruction *Val = NewElts[Idx]; 1992 if (Val->getType() != BC->getDestTy()) { 1993 Val = new BitCastInst(Val, BC->getDestTy(), "", BC); 1994 Val->takeName(BC); 1995 } 1996 BC->replaceAllUsesWith(Val); 1997 DeadInsts.push_back(BC); 1998} 1999 2000/// FindElementAndOffset - Return the index of the element containing Offset 2001/// within the specified type, which must be either a struct or an array. 2002/// Sets T to the type of the element and Offset to the offset within that 2003/// element. IdxTy is set to the type of the index result to be used in a 2004/// GEP instruction. 2005uint64_t SROA::FindElementAndOffset(Type *&T, uint64_t &Offset, 2006 Type *&IdxTy) { 2007 uint64_t Idx = 0; 2008 if (StructType *ST = dyn_cast<StructType>(T)) { 2009 const StructLayout *Layout = DL->getStructLayout(ST); 2010 Idx = Layout->getElementContainingOffset(Offset); 2011 T = ST->getContainedType(Idx); 2012 Offset -= Layout->getElementOffset(Idx); 2013 IdxTy = Type::getInt32Ty(T->getContext()); 2014 return Idx; 2015 } else if (ArrayType *AT = dyn_cast<ArrayType>(T)) { 2016 T = AT->getElementType(); 2017 uint64_t EltSize = DL->getTypeAllocSize(T); 2018 Idx = Offset / EltSize; 2019 Offset -= Idx * EltSize; 2020 IdxTy = Type::getInt64Ty(T->getContext()); 2021 return Idx; 2022 } 2023 VectorType *VT = cast<VectorType>(T); 2024 T = VT->getElementType(); 2025 uint64_t EltSize = DL->getTypeAllocSize(T); 2026 Idx = Offset / EltSize; 2027 Offset -= Idx * EltSize; 2028 IdxTy = Type::getInt64Ty(T->getContext()); 2029 return Idx; 2030} 2031 2032/// RewriteGEP - Check if this GEP instruction moves the pointer across 2033/// elements of the alloca that are being split apart, and if so, rewrite 2034/// the GEP to be relative to the new element. 2035void SROA::RewriteGEP(GetElementPtrInst *GEPI, AllocaInst *AI, uint64_t Offset, 2036 SmallVectorImpl<AllocaInst *> &NewElts) { 2037 uint64_t OldOffset = Offset; 2038 SmallVector<Value*, 8> Indices(GEPI->op_begin() + 1, GEPI->op_end()); 2039 // If the GEP was dynamic then it must have been a dynamic vector lookup. 2040 // In this case, it must be the last GEP operand which is dynamic so keep that 2041 // aside until we've found the constant GEP offset then add it back in at the 2042 // end. 2043 Value* NonConstantIdx = nullptr; 2044 if (!GEPI->hasAllConstantIndices()) 2045 NonConstantIdx = Indices.pop_back_val(); 2046 Offset += DL->getIndexedOffset(GEPI->getPointerOperandType(), Indices); 2047 2048 RewriteForScalarRepl(GEPI, AI, Offset, NewElts); 2049 2050 Type *T = AI->getAllocatedType(); 2051 Type *IdxTy; 2052 uint64_t OldIdx = FindElementAndOffset(T, OldOffset, IdxTy); 2053 if (GEPI->getOperand(0) == AI) 2054 OldIdx = ~0ULL; // Force the GEP to be rewritten. 2055 2056 T = AI->getAllocatedType(); 2057 uint64_t EltOffset = Offset; 2058 uint64_t Idx = FindElementAndOffset(T, EltOffset, IdxTy); 2059 2060 // If this GEP does not move the pointer across elements of the alloca 2061 // being split, then it does not needs to be rewritten. 2062 if (Idx == OldIdx) 2063 return; 2064 2065 Type *i32Ty = Type::getInt32Ty(AI->getContext()); 2066 SmallVector<Value*, 8> NewArgs; 2067 NewArgs.push_back(Constant::getNullValue(i32Ty)); 2068 while (EltOffset != 0) { 2069 uint64_t EltIdx = FindElementAndOffset(T, EltOffset, IdxTy); 2070 NewArgs.push_back(ConstantInt::get(IdxTy, EltIdx)); 2071 } 2072 if (NonConstantIdx) { 2073 Type* GepTy = T; 2074 // This GEP has a dynamic index. We need to add "i32 0" to index through 2075 // any structs or arrays in the original type until we get to the vector 2076 // to index. 2077 while (!isa<VectorType>(GepTy)) { 2078 NewArgs.push_back(Constant::getNullValue(i32Ty)); 2079 GepTy = cast<CompositeType>(GepTy)->getTypeAtIndex(0U); 2080 } 2081 NewArgs.push_back(NonConstantIdx); 2082 } 2083 Instruction *Val = NewElts[Idx]; 2084 if (NewArgs.size() > 1) { 2085 Val = GetElementPtrInst::CreateInBounds(Val, NewArgs, "", GEPI); 2086 Val->takeName(GEPI); 2087 } 2088 if (Val->getType() != GEPI->getType()) 2089 Val = new BitCastInst(Val, GEPI->getType(), Val->getName(), GEPI); 2090 GEPI->replaceAllUsesWith(Val); 2091 DeadInsts.push_back(GEPI); 2092} 2093 2094/// RewriteLifetimeIntrinsic - II is a lifetime.start/lifetime.end. Rewrite it 2095/// to mark the lifetime of the scalarized memory. 2096void SROA::RewriteLifetimeIntrinsic(IntrinsicInst *II, AllocaInst *AI, 2097 uint64_t Offset, 2098 SmallVectorImpl<AllocaInst *> &NewElts) { 2099 ConstantInt *OldSize = cast<ConstantInt>(II->getArgOperand(0)); 2100 // Put matching lifetime markers on everything from Offset up to 2101 // Offset+OldSize. 2102 Type *AIType = AI->getAllocatedType(); 2103 uint64_t NewOffset = Offset; 2104 Type *IdxTy; 2105 uint64_t Idx = FindElementAndOffset(AIType, NewOffset, IdxTy); 2106 2107 IRBuilder<> Builder(II); 2108 uint64_t Size = OldSize->getLimitedValue(); 2109 2110 if (NewOffset) { 2111 // Splice the first element and index 'NewOffset' bytes in. SROA will 2112 // split the alloca again later. 2113 unsigned AS = AI->getType()->getAddressSpace(); 2114 Value *V = Builder.CreateBitCast(NewElts[Idx], Builder.getInt8PtrTy(AS)); 2115 V = Builder.CreateGEP(V, Builder.getInt64(NewOffset)); 2116 2117 IdxTy = NewElts[Idx]->getAllocatedType(); 2118 uint64_t EltSize = DL->getTypeAllocSize(IdxTy) - NewOffset; 2119 if (EltSize > Size) { 2120 EltSize = Size; 2121 Size = 0; 2122 } else { 2123 Size -= EltSize; 2124 } 2125 if (II->getIntrinsicID() == Intrinsic::lifetime_start) 2126 Builder.CreateLifetimeStart(V, Builder.getInt64(EltSize)); 2127 else 2128 Builder.CreateLifetimeEnd(V, Builder.getInt64(EltSize)); 2129 ++Idx; 2130 } 2131 2132 for (; Idx != NewElts.size() && Size; ++Idx) { 2133 IdxTy = NewElts[Idx]->getAllocatedType(); 2134 uint64_t EltSize = DL->getTypeAllocSize(IdxTy); 2135 if (EltSize > Size) { 2136 EltSize = Size; 2137 Size = 0; 2138 } else { 2139 Size -= EltSize; 2140 } 2141 if (II->getIntrinsicID() == Intrinsic::lifetime_start) 2142 Builder.CreateLifetimeStart(NewElts[Idx], 2143 Builder.getInt64(EltSize)); 2144 else 2145 Builder.CreateLifetimeEnd(NewElts[Idx], 2146 Builder.getInt64(EltSize)); 2147 } 2148 DeadInsts.push_back(II); 2149} 2150 2151/// RewriteMemIntrinUserOfAlloca - MI is a memcpy/memset/memmove from or to AI. 2152/// Rewrite it to copy or set the elements of the scalarized memory. 2153void 2154SROA::RewriteMemIntrinUserOfAlloca(MemIntrinsic *MI, Instruction *Inst, 2155 AllocaInst *AI, 2156 SmallVectorImpl<AllocaInst *> &NewElts) { 2157 // If this is a memcpy/memmove, construct the other pointer as the 2158 // appropriate type. The "Other" pointer is the pointer that goes to memory 2159 // that doesn't have anything to do with the alloca that we are promoting. For 2160 // memset, this Value* stays null. 2161 Value *OtherPtr = nullptr; 2162 unsigned MemAlignment = MI->getAlignment(); 2163 if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI)) { // memmove/memcopy 2164 if (Inst == MTI->getRawDest()) 2165 OtherPtr = MTI->getRawSource(); 2166 else { 2167 assert(Inst == MTI->getRawSource()); 2168 OtherPtr = MTI->getRawDest(); 2169 } 2170 } 2171 2172 // If there is an other pointer, we want to convert it to the same pointer 2173 // type as AI has, so we can GEP through it safely. 2174 if (OtherPtr) { 2175 unsigned AddrSpace = 2176 cast<PointerType>(OtherPtr->getType())->getAddressSpace(); 2177 2178 // Remove bitcasts and all-zero GEPs from OtherPtr. This is an 2179 // optimization, but it's also required to detect the corner case where 2180 // both pointer operands are referencing the same memory, and where 2181 // OtherPtr may be a bitcast or GEP that currently being rewritten. (This 2182 // function is only called for mem intrinsics that access the whole 2183 // aggregate, so non-zero GEPs are not an issue here.) 2184 OtherPtr = OtherPtr->stripPointerCasts(); 2185 2186 // Copying the alloca to itself is a no-op: just delete it. 2187 if (OtherPtr == AI || OtherPtr == NewElts[0]) { 2188 // This code will run twice for a no-op memcpy -- once for each operand. 2189 // Put only one reference to MI on the DeadInsts list. 2190 for (SmallVectorImpl<Value *>::const_iterator I = DeadInsts.begin(), 2191 E = DeadInsts.end(); I != E; ++I) 2192 if (*I == MI) return; 2193 DeadInsts.push_back(MI); 2194 return; 2195 } 2196 2197 // If the pointer is not the right type, insert a bitcast to the right 2198 // type. 2199 Type *NewTy = 2200 PointerType::get(AI->getType()->getElementType(), AddrSpace); 2201 2202 if (OtherPtr->getType() != NewTy) 2203 OtherPtr = new BitCastInst(OtherPtr, NewTy, OtherPtr->getName(), MI); 2204 } 2205 2206 // Process each element of the aggregate. 2207 bool SROADest = MI->getRawDest() == Inst; 2208 2209 Constant *Zero = Constant::getNullValue(Type::getInt32Ty(MI->getContext())); 2210 2211 for (unsigned i = 0, e = NewElts.size(); i != e; ++i) { 2212 // If this is a memcpy/memmove, emit a GEP of the other element address. 2213 Value *OtherElt = nullptr; 2214 unsigned OtherEltAlign = MemAlignment; 2215 2216 if (OtherPtr) { 2217 Value *Idx[2] = { Zero, 2218 ConstantInt::get(Type::getInt32Ty(MI->getContext()), i) }; 2219 OtherElt = GetElementPtrInst::CreateInBounds(OtherPtr, Idx, 2220 OtherPtr->getName()+"."+Twine(i), 2221 MI); 2222 uint64_t EltOffset; 2223 PointerType *OtherPtrTy = cast<PointerType>(OtherPtr->getType()); 2224 Type *OtherTy = OtherPtrTy->getElementType(); 2225 if (StructType *ST = dyn_cast<StructType>(OtherTy)) { 2226 EltOffset = DL->getStructLayout(ST)->getElementOffset(i); 2227 } else { 2228 Type *EltTy = cast<SequentialType>(OtherTy)->getElementType(); 2229 EltOffset = DL->getTypeAllocSize(EltTy)*i; 2230 } 2231 2232 // The alignment of the other pointer is the guaranteed alignment of the 2233 // element, which is affected by both the known alignment of the whole 2234 // mem intrinsic and the alignment of the element. If the alignment of 2235 // the memcpy (f.e.) is 32 but the element is at a 4-byte offset, then the 2236 // known alignment is just 4 bytes. 2237 OtherEltAlign = (unsigned)MinAlign(OtherEltAlign, EltOffset); 2238 } 2239 2240 Value *EltPtr = NewElts[i]; 2241 Type *EltTy = cast<PointerType>(EltPtr->getType())->getElementType(); 2242 2243 // If we got down to a scalar, insert a load or store as appropriate. 2244 if (EltTy->isSingleValueType()) { 2245 if (isa<MemTransferInst>(MI)) { 2246 if (SROADest) { 2247 // From Other to Alloca. 2248 Value *Elt = new LoadInst(OtherElt, "tmp", false, OtherEltAlign, MI); 2249 new StoreInst(Elt, EltPtr, MI); 2250 } else { 2251 // From Alloca to Other. 2252 Value *Elt = new LoadInst(EltPtr, "tmp", MI); 2253 new StoreInst(Elt, OtherElt, false, OtherEltAlign, MI); 2254 } 2255 continue; 2256 } 2257 assert(isa<MemSetInst>(MI)); 2258 2259 // If the stored element is zero (common case), just store a null 2260 // constant. 2261 Constant *StoreVal; 2262 if (ConstantInt *CI = dyn_cast<ConstantInt>(MI->getArgOperand(1))) { 2263 if (CI->isZero()) { 2264 StoreVal = Constant::getNullValue(EltTy); // 0.0, null, 0, <0,0> 2265 } else { 2266 // If EltTy is a vector type, get the element type. 2267 Type *ValTy = EltTy->getScalarType(); 2268 2269 // Construct an integer with the right value. 2270 unsigned EltSize = DL->getTypeSizeInBits(ValTy); 2271 APInt OneVal(EltSize, CI->getZExtValue()); 2272 APInt TotalVal(OneVal); 2273 // Set each byte. 2274 for (unsigned i = 0; 8*i < EltSize; ++i) { 2275 TotalVal = TotalVal.shl(8); 2276 TotalVal |= OneVal; 2277 } 2278 2279 // Convert the integer value to the appropriate type. 2280 StoreVal = ConstantInt::get(CI->getContext(), TotalVal); 2281 if (ValTy->isPointerTy()) 2282 StoreVal = ConstantExpr::getIntToPtr(StoreVal, ValTy); 2283 else if (ValTy->isFloatingPointTy()) 2284 StoreVal = ConstantExpr::getBitCast(StoreVal, ValTy); 2285 assert(StoreVal->getType() == ValTy && "Type mismatch!"); 2286 2287 // If the requested value was a vector constant, create it. 2288 if (EltTy->isVectorTy()) { 2289 unsigned NumElts = cast<VectorType>(EltTy)->getNumElements(); 2290 StoreVal = ConstantVector::getSplat(NumElts, StoreVal); 2291 } 2292 } 2293 new StoreInst(StoreVal, EltPtr, MI); 2294 continue; 2295 } 2296 // Otherwise, if we're storing a byte variable, use a memset call for 2297 // this element. 2298 } 2299 2300 unsigned EltSize = DL->getTypeAllocSize(EltTy); 2301 if (!EltSize) 2302 continue; 2303 2304 IRBuilder<> Builder(MI); 2305 2306 // Finally, insert the meminst for this element. 2307 if (isa<MemSetInst>(MI)) { 2308 Builder.CreateMemSet(EltPtr, MI->getArgOperand(1), EltSize, 2309 MI->isVolatile()); 2310 } else { 2311 assert(isa<MemTransferInst>(MI)); 2312 Value *Dst = SROADest ? EltPtr : OtherElt; // Dest ptr 2313 Value *Src = SROADest ? OtherElt : EltPtr; // Src ptr 2314 2315 if (isa<MemCpyInst>(MI)) 2316 Builder.CreateMemCpy(Dst, Src, EltSize, OtherEltAlign,MI->isVolatile()); 2317 else 2318 Builder.CreateMemMove(Dst, Src, EltSize,OtherEltAlign,MI->isVolatile()); 2319 } 2320 } 2321 DeadInsts.push_back(MI); 2322} 2323 2324/// RewriteStoreUserOfWholeAlloca - We found a store of an integer that 2325/// overwrites the entire allocation. Extract out the pieces of the stored 2326/// integer and store them individually. 2327void 2328SROA::RewriteStoreUserOfWholeAlloca(StoreInst *SI, AllocaInst *AI, 2329 SmallVectorImpl<AllocaInst *> &NewElts) { 2330 // Extract each element out of the integer according to its structure offset 2331 // and store the element value to the individual alloca. 2332 Value *SrcVal = SI->getOperand(0); 2333 Type *AllocaEltTy = AI->getAllocatedType(); 2334 uint64_t AllocaSizeBits = DL->getTypeAllocSizeInBits(AllocaEltTy); 2335 2336 IRBuilder<> Builder(SI); 2337 2338 // Handle tail padding by extending the operand 2339 if (DL->getTypeSizeInBits(SrcVal->getType()) != AllocaSizeBits) 2340 SrcVal = Builder.CreateZExt(SrcVal, 2341 IntegerType::get(SI->getContext(), AllocaSizeBits)); 2342 2343 DEBUG(dbgs() << "PROMOTING STORE TO WHOLE ALLOCA: " << *AI << '\n' << *SI 2344 << '\n'); 2345 2346 // There are two forms here: AI could be an array or struct. Both cases 2347 // have different ways to compute the element offset. 2348 if (StructType *EltSTy = dyn_cast<StructType>(AllocaEltTy)) { 2349 const StructLayout *Layout = DL->getStructLayout(EltSTy); 2350 2351 for (unsigned i = 0, e = NewElts.size(); i != e; ++i) { 2352 // Get the number of bits to shift SrcVal to get the value. 2353 Type *FieldTy = EltSTy->getElementType(i); 2354 uint64_t Shift = Layout->getElementOffsetInBits(i); 2355 2356 if (DL->isBigEndian()) 2357 Shift = AllocaSizeBits-Shift-DL->getTypeAllocSizeInBits(FieldTy); 2358 2359 Value *EltVal = SrcVal; 2360 if (Shift) { 2361 Value *ShiftVal = ConstantInt::get(EltVal->getType(), Shift); 2362 EltVal = Builder.CreateLShr(EltVal, ShiftVal, "sroa.store.elt"); 2363 } 2364 2365 // Truncate down to an integer of the right size. 2366 uint64_t FieldSizeBits = DL->getTypeSizeInBits(FieldTy); 2367 2368 // Ignore zero sized fields like {}, they obviously contain no data. 2369 if (FieldSizeBits == 0) continue; 2370 2371 if (FieldSizeBits != AllocaSizeBits) 2372 EltVal = Builder.CreateTrunc(EltVal, 2373 IntegerType::get(SI->getContext(), FieldSizeBits)); 2374 Value *DestField = NewElts[i]; 2375 if (EltVal->getType() == FieldTy) { 2376 // Storing to an integer field of this size, just do it. 2377 } else if (FieldTy->isFloatingPointTy() || FieldTy->isVectorTy()) { 2378 // Bitcast to the right element type (for fp/vector values). 2379 EltVal = Builder.CreateBitCast(EltVal, FieldTy); 2380 } else { 2381 // Otherwise, bitcast the dest pointer (for aggregates). 2382 DestField = Builder.CreateBitCast(DestField, 2383 PointerType::getUnqual(EltVal->getType())); 2384 } 2385 new StoreInst(EltVal, DestField, SI); 2386 } 2387 2388 } else { 2389 ArrayType *ATy = cast<ArrayType>(AllocaEltTy); 2390 Type *ArrayEltTy = ATy->getElementType(); 2391 uint64_t ElementOffset = DL->getTypeAllocSizeInBits(ArrayEltTy); 2392 uint64_t ElementSizeBits = DL->getTypeSizeInBits(ArrayEltTy); 2393 2394 uint64_t Shift; 2395 2396 if (DL->isBigEndian()) 2397 Shift = AllocaSizeBits-ElementOffset; 2398 else 2399 Shift = 0; 2400 2401 for (unsigned i = 0, e = NewElts.size(); i != e; ++i) { 2402 // Ignore zero sized fields like {}, they obviously contain no data. 2403 if (ElementSizeBits == 0) continue; 2404 2405 Value *EltVal = SrcVal; 2406 if (Shift) { 2407 Value *ShiftVal = ConstantInt::get(EltVal->getType(), Shift); 2408 EltVal = Builder.CreateLShr(EltVal, ShiftVal, "sroa.store.elt"); 2409 } 2410 2411 // Truncate down to an integer of the right size. 2412 if (ElementSizeBits != AllocaSizeBits) 2413 EltVal = Builder.CreateTrunc(EltVal, 2414 IntegerType::get(SI->getContext(), 2415 ElementSizeBits)); 2416 Value *DestField = NewElts[i]; 2417 if (EltVal->getType() == ArrayEltTy) { 2418 // Storing to an integer field of this size, just do it. 2419 } else if (ArrayEltTy->isFloatingPointTy() || 2420 ArrayEltTy->isVectorTy()) { 2421 // Bitcast to the right element type (for fp/vector values). 2422 EltVal = Builder.CreateBitCast(EltVal, ArrayEltTy); 2423 } else { 2424 // Otherwise, bitcast the dest pointer (for aggregates). 2425 DestField = Builder.CreateBitCast(DestField, 2426 PointerType::getUnqual(EltVal->getType())); 2427 } 2428 new StoreInst(EltVal, DestField, SI); 2429 2430 if (DL->isBigEndian()) 2431 Shift -= ElementOffset; 2432 else 2433 Shift += ElementOffset; 2434 } 2435 } 2436 2437 DeadInsts.push_back(SI); 2438} 2439 2440/// RewriteLoadUserOfWholeAlloca - We found a load of the entire allocation to 2441/// an integer. Load the individual pieces to form the aggregate value. 2442void 2443SROA::RewriteLoadUserOfWholeAlloca(LoadInst *LI, AllocaInst *AI, 2444 SmallVectorImpl<AllocaInst *> &NewElts) { 2445 // Extract each element out of the NewElts according to its structure offset 2446 // and form the result value. 2447 Type *AllocaEltTy = AI->getAllocatedType(); 2448 uint64_t AllocaSizeBits = DL->getTypeAllocSizeInBits(AllocaEltTy); 2449 2450 DEBUG(dbgs() << "PROMOTING LOAD OF WHOLE ALLOCA: " << *AI << '\n' << *LI 2451 << '\n'); 2452 2453 // There are two forms here: AI could be an array or struct. Both cases 2454 // have different ways to compute the element offset. 2455 const StructLayout *Layout = nullptr; 2456 uint64_t ArrayEltBitOffset = 0; 2457 if (StructType *EltSTy = dyn_cast<StructType>(AllocaEltTy)) { 2458 Layout = DL->getStructLayout(EltSTy); 2459 } else { 2460 Type *ArrayEltTy = cast<ArrayType>(AllocaEltTy)->getElementType(); 2461 ArrayEltBitOffset = DL->getTypeAllocSizeInBits(ArrayEltTy); 2462 } 2463 2464 Value *ResultVal = 2465 Constant::getNullValue(IntegerType::get(LI->getContext(), AllocaSizeBits)); 2466 2467 for (unsigned i = 0, e = NewElts.size(); i != e; ++i) { 2468 // Load the value from the alloca. If the NewElt is an aggregate, cast 2469 // the pointer to an integer of the same size before doing the load. 2470 Value *SrcField = NewElts[i]; 2471 Type *FieldTy = 2472 cast<PointerType>(SrcField->getType())->getElementType(); 2473 uint64_t FieldSizeBits = DL->getTypeSizeInBits(FieldTy); 2474 2475 // Ignore zero sized fields like {}, they obviously contain no data. 2476 if (FieldSizeBits == 0) continue; 2477 2478 IntegerType *FieldIntTy = IntegerType::get(LI->getContext(), 2479 FieldSizeBits); 2480 if (!FieldTy->isIntegerTy() && !FieldTy->isFloatingPointTy() && 2481 !FieldTy->isVectorTy()) 2482 SrcField = new BitCastInst(SrcField, 2483 PointerType::getUnqual(FieldIntTy), 2484 "", LI); 2485 SrcField = new LoadInst(SrcField, "sroa.load.elt", LI); 2486 2487 // If SrcField is a fp or vector of the right size but that isn't an 2488 // integer type, bitcast to an integer so we can shift it. 2489 if (SrcField->getType() != FieldIntTy) 2490 SrcField = new BitCastInst(SrcField, FieldIntTy, "", LI); 2491 2492 // Zero extend the field to be the same size as the final alloca so that 2493 // we can shift and insert it. 2494 if (SrcField->getType() != ResultVal->getType()) 2495 SrcField = new ZExtInst(SrcField, ResultVal->getType(), "", LI); 2496 2497 // Determine the number of bits to shift SrcField. 2498 uint64_t Shift; 2499 if (Layout) // Struct case. 2500 Shift = Layout->getElementOffsetInBits(i); 2501 else // Array case. 2502 Shift = i*ArrayEltBitOffset; 2503 2504 if (DL->isBigEndian()) 2505 Shift = AllocaSizeBits-Shift-FieldIntTy->getBitWidth(); 2506 2507 if (Shift) { 2508 Value *ShiftVal = ConstantInt::get(SrcField->getType(), Shift); 2509 SrcField = BinaryOperator::CreateShl(SrcField, ShiftVal, "", LI); 2510 } 2511 2512 // Don't create an 'or x, 0' on the first iteration. 2513 if (!isa<Constant>(ResultVal) || 2514 !cast<Constant>(ResultVal)->isNullValue()) 2515 ResultVal = BinaryOperator::CreateOr(SrcField, ResultVal, "", LI); 2516 else 2517 ResultVal = SrcField; 2518 } 2519 2520 // Handle tail padding by truncating the result 2521 if (DL->getTypeSizeInBits(LI->getType()) != AllocaSizeBits) 2522 ResultVal = new TruncInst(ResultVal, LI->getType(), "", LI); 2523 2524 LI->replaceAllUsesWith(ResultVal); 2525 DeadInsts.push_back(LI); 2526} 2527 2528/// HasPadding - Return true if the specified type has any structure or 2529/// alignment padding in between the elements that would be split apart 2530/// by SROA; return false otherwise. 2531static bool HasPadding(Type *Ty, const DataLayout &DL) { 2532 if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) { 2533 Ty = ATy->getElementType(); 2534 return DL.getTypeSizeInBits(Ty) != DL.getTypeAllocSizeInBits(Ty); 2535 } 2536 2537 // SROA currently handles only Arrays and Structs. 2538 StructType *STy = cast<StructType>(Ty); 2539 const StructLayout *SL = DL.getStructLayout(STy); 2540 unsigned PrevFieldBitOffset = 0; 2541 for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { 2542 unsigned FieldBitOffset = SL->getElementOffsetInBits(i); 2543 2544 // Check to see if there is any padding between this element and the 2545 // previous one. 2546 if (i) { 2547 unsigned PrevFieldEnd = 2548 PrevFieldBitOffset+DL.getTypeSizeInBits(STy->getElementType(i-1)); 2549 if (PrevFieldEnd < FieldBitOffset) 2550 return true; 2551 } 2552 PrevFieldBitOffset = FieldBitOffset; 2553 } 2554 // Check for tail padding. 2555 if (unsigned EltCount = STy->getNumElements()) { 2556 unsigned PrevFieldEnd = PrevFieldBitOffset + 2557 DL.getTypeSizeInBits(STy->getElementType(EltCount-1)); 2558 if (PrevFieldEnd < SL->getSizeInBits()) 2559 return true; 2560 } 2561 return false; 2562} 2563 2564/// isSafeStructAllocaToScalarRepl - Check to see if the specified allocation of 2565/// an aggregate can be broken down into elements. Return 0 if not, 3 if safe, 2566/// or 1 if safe after canonicalization has been performed. 2567bool SROA::isSafeAllocaToScalarRepl(AllocaInst *AI) { 2568 // Loop over the use list of the alloca. We can only transform it if all of 2569 // the users are safe to transform. 2570 AllocaInfo Info(AI); 2571 2572 isSafeForScalarRepl(AI, 0, Info); 2573 if (Info.isUnsafe) { 2574 DEBUG(dbgs() << "Cannot transform: " << *AI << '\n'); 2575 return false; 2576 } 2577 2578 // Okay, we know all the users are promotable. If the aggregate is a memcpy 2579 // source and destination, we have to be careful. In particular, the memcpy 2580 // could be moving around elements that live in structure padding of the LLVM 2581 // types, but may actually be used. In these cases, we refuse to promote the 2582 // struct. 2583 if (Info.isMemCpySrc && Info.isMemCpyDst && 2584 HasPadding(AI->getAllocatedType(), *DL)) 2585 return false; 2586 2587 // If the alloca never has an access to just *part* of it, but is accessed 2588 // via loads and stores, then we should use ConvertToScalarInfo to promote 2589 // the alloca instead of promoting each piece at a time and inserting fission 2590 // and fusion code. 2591 if (!Info.hasSubelementAccess && Info.hasALoadOrStore) { 2592 // If the struct/array just has one element, use basic SRoA. 2593 if (StructType *ST = dyn_cast<StructType>(AI->getAllocatedType())) { 2594 if (ST->getNumElements() > 1) return false; 2595 } else { 2596 if (cast<ArrayType>(AI->getAllocatedType())->getNumElements() > 1) 2597 return false; 2598 } 2599 } 2600 2601 return true; 2602} 2603