CodeGenPrepare.cpp revision 80f6a507d4e11ba066ad0e53e12ad25ad8cf07ba
1dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner//===- CodeGenPrepare.cpp - Prepare a function for code generation --------===// 2dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner// 3dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner// The LLVM Compiler Infrastructure 4dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner// 54ee451de366474b9c228b4e5fa573795a715216dChris Lattner// This file is distributed under the University of Illinois Open Source 64ee451de366474b9c228b4e5fa573795a715216dChris Lattner// License. See LICENSE.TXT for details. 7dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner// 8dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner//===----------------------------------------------------------------------===// 9dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner// 10dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner// This pass munges the code in the input function to better prepare it for 11a8a118b68fa3ca1632e7280cd6994aa0f8f1eec1Gordon Henriksen// SelectionDAG-based code generation. This works around limitations in it's 12a8a118b68fa3ca1632e7280cd6994aa0f8f1eec1Gordon Henriksen// basic-block-at-a-time approach. It should eventually be removed. 13dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner// 14dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner//===----------------------------------------------------------------------===// 15dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner 16dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner#define DEBUG_TYPE "codegenprepare" 17dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner#include "llvm/Transforms/Scalar.h" 18dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner#include "llvm/Constants.h" 19dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner#include "llvm/DerivedTypes.h" 20dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner#include "llvm/Function.h" 219bf12b5583104c810cfadcdce91edf9efad79973Evan Cheng#include "llvm/InlineAsm.h" 22dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner#include "llvm/Instructions.h" 236aae1d6582fe8519c42d9774d670bb93c78e9637Dale Johannesen#include "llvm/IntrinsicInst.h" 24dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner#include "llvm/Pass.h" 2580f6a507d4e11ba066ad0e53e12ad25ad8cf07baCameron Zwarich#include "llvm/Analysis/Dominators.h" 26d5f8684b16057df73771b23e293b400cb327e079Owen Anderson#include "llvm/Analysis/InstructionSimplify.h" 27ad80981a106c9d0ec83351e63ee3ac75ed646bf4Andreas Neustifter#include "llvm/Analysis/ProfileInfo.h" 28dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner#include "llvm/Target/TargetData.h" 29dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner#include "llvm/Target/TargetLowering.h" 30a1fd5b386dd8eb4c86bfd2b9659c219a1c4f56dbEvan Cheng#include "llvm/Transforms/Utils/AddrModeMatcher.h" 31dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner#include "llvm/Transforms/Utils/BasicBlockUtils.h" 32dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner#include "llvm/Transforms/Utils/Local.h" 33040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher#include "llvm/Transforms/Utils/BuildLibCalls.h" 34dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner#include "llvm/ADT/DenseMap.h" 35dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner#include "llvm/ADT/SmallSet.h" 367eb589d3f9294dbfe4d5205045bd8119a9666532Jakob Stoklund Olesen#include "llvm/ADT/Statistic.h" 3703ce042d70c423a41edca0714112a0e06b16493bDan Gohman#include "llvm/Assembly/Writer.h" 389bf12b5583104c810cfadcdce91edf9efad79973Evan Cheng#include "llvm/Support/CallSite.h" 39e1bcb440dc0ca3c41fda1c0c581abfc4f38ca170Evan Cheng#include "llvm/Support/CommandLine.h" 40bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng#include "llvm/Support/Debug.h" 41dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner#include "llvm/Support/GetElementPtrTypeIterator.h" 42088a1e84ea985a22efcf907d7789064fee3a97b9Chris Lattner#include "llvm/Support/PatternMatch.h" 436c1980b3357207c4d756255bc5e32323eac278dcDan Gohman#include "llvm/Support/raw_ostream.h" 44040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher#include "llvm/Support/IRBuilder.h" 45dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattnerusing namespace llvm; 46088a1e84ea985a22efcf907d7789064fee3a97b9Chris Lattnerusing namespace llvm::PatternMatch; 47dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner 4831ff1333e0651192212cee6e090df2ff57d19b53Cameron ZwarichSTATISTIC(NumBlocksElim, "Number of blocks eliminated"); 49073057f0d0a1e21ab020fa71ff4bd11543faa6d0Cameron ZwarichSTATISTIC(NumPHIsElim, "Number of trivial PHIs eliminated"); 50073057f0d0a1e21ab020fa71ff4bd11543faa6d0Cameron ZwarichSTATISTIC(NumGEPsElim, "Number of GEPs converted to casts"); 5131ff1333e0651192212cee6e090df2ff57d19b53Cameron ZwarichSTATISTIC(NumCmpUses, "Number of uses of Cmp expressions replaced with uses of " 5231ff1333e0651192212cee6e090df2ff57d19b53Cameron Zwarich "sunken Cmps"); 5331ff1333e0651192212cee6e090df2ff57d19b53Cameron ZwarichSTATISTIC(NumCastUses, "Number of uses of Cast expressions replaced with uses " 5431ff1333e0651192212cee6e090df2ff57d19b53Cameron Zwarich "of sunken Casts"); 5531ff1333e0651192212cee6e090df2ff57d19b53Cameron ZwarichSTATISTIC(NumMemoryInsts, "Number of memory instructions whose address " 5631ff1333e0651192212cee6e090df2ff57d19b53Cameron Zwarich "computations were sunk"); 5731ff1333e0651192212cee6e090df2ff57d19b53Cameron ZwarichSTATISTIC(NumExtsMoved, "Number of [s|z]ext instructions combined with loads"); 5831ff1333e0651192212cee6e090df2ff57d19b53Cameron ZwarichSTATISTIC(NumExtUses, "Number of uses of [s|z]ext instructions optimized"); 597eb589d3f9294dbfe4d5205045bd8119a9666532Jakob Stoklund Olesen 60e1bcb440dc0ca3c41fda1c0c581abfc4f38ca170Evan Chengstatic cl::opt<bool> 61e1bcb440dc0ca3c41fda1c0c581abfc4f38ca170Evan ChengCriticalEdgeSplit("cgp-critical-edge-splitting", 62e1bcb440dc0ca3c41fda1c0c581abfc4f38ca170Evan Cheng cl::desc("Split critical edges during codegen prepare"), 637eb589d3f9294dbfe4d5205045bd8119a9666532Jakob Stoklund Olesen cl::init(false), cl::Hidden); 64e1bcb440dc0ca3c41fda1c0c581abfc4f38ca170Evan Cheng 65692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christophernamespace { 663e8b6631e67e01e4960a7ba4668a50c596607473Chris Lattner class CodeGenPrepare : public FunctionPass { 67dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner /// TLI - Keep a pointer of a TargetLowering to consult for determining 68dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner /// transformation profitability. 69dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner const TargetLowering *TLI; 7080f6a507d4e11ba066ad0e53e12ad25ad8cf07baCameron Zwarich DominatorTree *DT; 7104149f7ffd033773adfe85e4acf3f560e29bd47dEvan Cheng ProfileInfo *PFI; 72ab63152871f4144050d0a58d592a95e089fe40d4Evan Cheng 73ab63152871f4144050d0a58d592a95e089fe40d4Evan Cheng /// BackEdges - Keep a set of all the loop back edges. 74ab63152871f4144050d0a58d592a95e089fe40d4Evan Cheng /// 75fe095f39e7009c51d1c86769792ccbcad8cdd2ecMike Stump SmallSet<std::pair<const BasicBlock*, const BasicBlock*>, 8> BackEdges; 768c3527e7a475dd3369a485a4f610d56f7005b7b5Cameron Zwarich 778c3527e7a475dd3369a485a4f610d56f7005b7b5Cameron Zwarich // Keeps track of non-local addresses that have been sunk into a block. This 788c3527e7a475dd3369a485a4f610d56f7005b7b5Cameron Zwarich // allows us to avoid inserting duplicate code for blocks with multiple 798c3527e7a475dd3369a485a4f610d56f7005b7b5Cameron Zwarich // load/stores of the same address. 808c3527e7a475dd3369a485a4f610d56f7005b7b5Cameron Zwarich DenseMap<Value*, Value*> SunkAddrs; 818c3527e7a475dd3369a485a4f610d56f7005b7b5Cameron Zwarich 82dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner public: 83ecd94c804a563f2a86572dcf1d2e81f397e19daaNick Lewycky static char ID; // Pass identification, replacement for typeid 84c2bbfc18e9adbbdcf5b3375d8d25e2452f7df7f1Dan Gohman explicit CodeGenPrepare(const TargetLowering *tli = 0) 85081c34b725980f995be9080eaec24cd3dfaaf065Owen Anderson : FunctionPass(ID), TLI(tli) { 86081c34b725980f995be9080eaec24cd3dfaaf065Owen Anderson initializeCodeGenPreparePass(*PassRegistry::getPassRegistry()); 87081c34b725980f995be9080eaec24cd3dfaaf065Owen Anderson } 88dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner bool runOnFunction(Function &F); 89692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 90ad80981a106c9d0ec83351e63ee3ac75ed646bf4Andreas Neustifter virtual void getAnalysisUsage(AnalysisUsage &AU) const { 9180f6a507d4e11ba066ad0e53e12ad25ad8cf07baCameron Zwarich AU.addPreserved<DominatorTree>(); 92ad80981a106c9d0ec83351e63ee3ac75ed646bf4Andreas Neustifter AU.addPreserved<ProfileInfo>(); 93ad80981a106c9d0ec83351e63ee3ac75ed646bf4Andreas Neustifter } 94ad80981a106c9d0ec83351e63ee3ac75ed646bf4Andreas Neustifter 95aa0e52328747d982d6c6e501a205832ad724ff62Dan Gohman virtual void releaseMemory() { 96aa0e52328747d982d6c6e501a205832ad724ff62Dan Gohman BackEdges.clear(); 97aa0e52328747d982d6c6e501a205832ad724ff62Dan Gohman } 98aa0e52328747d982d6c6e501a205832ad724ff62Dan Gohman 99dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner private: 100d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner bool EliminateMostlyEmptyBlocks(Function &F); 101d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner bool CanMergeBlocks(const BasicBlock *BB, const BasicBlock *DestBB) const; 102d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner void EliminateMostlyEmptyBlock(BasicBlock *BB); 103dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner bool OptimizeBlock(BasicBlock &BB); 104c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich bool OptimizeInst(Instruction *I); 10588a5c832ac71eb31d2b1bc143817af9248f4c549Chris Lattner bool OptimizeMemoryInst(Instruction *I, Value *Addr, const Type *AccessTy, 10688a5c832ac71eb31d2b1bc143817af9248f4c549Chris Lattner DenseMap<Value*,Value*> &SunkAddrs); 1079bf12b5583104c810cfadcdce91edf9efad79973Evan Cheng bool OptimizeInlineAsmInst(Instruction *I, CallSite CS, 1089bf12b5583104c810cfadcdce91edf9efad79973Evan Cheng DenseMap<Value*,Value*> &SunkAddrs); 109040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher bool OptimizeCallInst(CallInst *CI); 110b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman bool MoveExtToFormExtLoad(Instruction *I); 111bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng bool OptimizeExtUses(Instruction *I); 112fe095f39e7009c51d1c86769792ccbcad8cdd2ecMike Stump void findLoopBackEdges(const Function &F); 113dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner }; 114dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner} 115794fd75c67a2cdc128d67342c6d88a504d186896Devang Patel 1161997473cf72957d0e70322e2fe6fe2ab141c58a6Devang Patelchar CodeGenPrepare::ID = 0; 117d13db2c59cc94162d6cf0a04187d408bfef6d4a7Owen AndersonINITIALIZE_PASS(CodeGenPrepare, "codegenprepare", 118ce665bd2e2b581ab0858d1afe359192bac96b868Owen Anderson "Optimize for code generation", false, false) 119dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner 120dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris LattnerFunctionPass *llvm::createCodeGenPreparePass(const TargetLowering *TLI) { 121dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner return new CodeGenPrepare(TLI); 122dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner} 123dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner 124ab63152871f4144050d0a58d592a95e089fe40d4Evan Cheng/// findLoopBackEdges - Do a DFS walk to find loop back edges. 125ab63152871f4144050d0a58d592a95e089fe40d4Evan Cheng/// 126fe095f39e7009c51d1c86769792ccbcad8cdd2ecMike Stumpvoid CodeGenPrepare::findLoopBackEdges(const Function &F) { 127fe095f39e7009c51d1c86769792ccbcad8cdd2ecMike Stump SmallVector<std::pair<const BasicBlock*,const BasicBlock*>, 32> Edges; 128fe095f39e7009c51d1c86769792ccbcad8cdd2ecMike Stump FindFunctionBackedges(F, Edges); 129fe095f39e7009c51d1c86769792ccbcad8cdd2ecMike Stump 130fe095f39e7009c51d1c86769792ccbcad8cdd2ecMike Stump BackEdges.insert(Edges.begin(), Edges.end()); 131ab63152871f4144050d0a58d592a95e089fe40d4Evan Cheng} 132ab63152871f4144050d0a58d592a95e089fe40d4Evan Cheng 133dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner 134dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattnerbool CodeGenPrepare::runOnFunction(Function &F) { 135dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner bool EverMadeChange = false; 136692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 13780f6a507d4e11ba066ad0e53e12ad25ad8cf07baCameron Zwarich DT = getAnalysisIfAvailable<DominatorTree>(); 13804149f7ffd033773adfe85e4acf3f560e29bd47dEvan Cheng PFI = getAnalysisIfAvailable<ProfileInfo>(); 139d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // First pass, eliminate blocks that contain only PHI nodes and an 140d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // unconditional branch. 141d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner EverMadeChange |= EliminateMostlyEmptyBlocks(F); 142692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 14395bb00414eba82cc1c058b558cd28bc28134c561Cameron Zwarich // Now find loop back edges, but only if they are being used to decide which 14495bb00414eba82cc1c058b558cd28bc28134c561Cameron Zwarich // critical edges to split. 14595bb00414eba82cc1c058b558cd28bc28134c561Cameron Zwarich if (CriticalEdgeSplit) 14695bb00414eba82cc1c058b558cd28bc28134c561Cameron Zwarich findLoopBackEdges(F); 1477e66c0d43aefce78948f0b73422f6e5bb28e2077Evan Cheng 148d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner bool MadeChange = true; 149dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner while (MadeChange) { 150dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner MadeChange = false; 151dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) 152dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner MadeChange |= OptimizeBlock(*BB); 153dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner EverMadeChange |= MadeChange; 154dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner } 1558c3527e7a475dd3369a485a4f610d56f7005b7b5Cameron Zwarich 1568c3527e7a475dd3369a485a4f610d56f7005b7b5Cameron Zwarich SunkAddrs.clear(); 1578c3527e7a475dd3369a485a4f610d56f7005b7b5Cameron Zwarich 158dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner return EverMadeChange; 159dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner} 160dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner 1612d69724938e67ec248e0ba42f86287923b3a5171Dale Johannesen/// EliminateMostlyEmptyBlocks - eliminate blocks that contain only PHI nodes, 1622d69724938e67ec248e0ba42f86287923b3a5171Dale Johannesen/// debug info directives, and an unconditional branch. Passes before isel 1632d69724938e67ec248e0ba42f86287923b3a5171Dale Johannesen/// (e.g. LSR/loopsimplify) often split edges in ways that are non-optimal for 1642d69724938e67ec248e0ba42f86287923b3a5171Dale Johannesen/// isel. Start by eliminating these blocks so we can split them the way we 1652d69724938e67ec248e0ba42f86287923b3a5171Dale Johannesen/// want them. 166d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattnerbool CodeGenPrepare::EliminateMostlyEmptyBlocks(Function &F) { 167d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner bool MadeChange = false; 168d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // Note that this intentionally skips the entry block. 169d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner for (Function::iterator I = ++F.begin(), E = F.end(); I != E; ) { 170d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner BasicBlock *BB = I++; 171d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner 172d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // If this block doesn't end with an uncond branch, ignore it. 173d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner BranchInst *BI = dyn_cast<BranchInst>(BB->getTerminator()); 174d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner if (!BI || !BI->isUnconditional()) 175d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner continue; 176692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 1772d69724938e67ec248e0ba42f86287923b3a5171Dale Johannesen // If the instruction before the branch (skipping debug info) isn't a phi 1782d69724938e67ec248e0ba42f86287923b3a5171Dale Johannesen // node, then other stuff is happening here. 179d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner BasicBlock::iterator BBI = BI; 180d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner if (BBI != BB->begin()) { 181d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner --BBI; 1822d69724938e67ec248e0ba42f86287923b3a5171Dale Johannesen while (isa<DbgInfoIntrinsic>(BBI)) { 1832d69724938e67ec248e0ba42f86287923b3a5171Dale Johannesen if (BBI == BB->begin()) 1842d69724938e67ec248e0ba42f86287923b3a5171Dale Johannesen break; 1852d69724938e67ec248e0ba42f86287923b3a5171Dale Johannesen --BBI; 1862d69724938e67ec248e0ba42f86287923b3a5171Dale Johannesen } 1872d69724938e67ec248e0ba42f86287923b3a5171Dale Johannesen if (!isa<DbgInfoIntrinsic>(BBI) && !isa<PHINode>(BBI)) 1882d69724938e67ec248e0ba42f86287923b3a5171Dale Johannesen continue; 189d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner } 190692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 191d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // Do not break infinite loops. 192d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner BasicBlock *DestBB = BI->getSuccessor(0); 193d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner if (DestBB == BB) 194d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner continue; 195692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 196d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner if (!CanMergeBlocks(BB, DestBB)) 197d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner continue; 198692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 199d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner EliminateMostlyEmptyBlock(BB); 200d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner MadeChange = true; 201d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner } 202d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner return MadeChange; 203d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner} 204d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner 205d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner/// CanMergeBlocks - Return true if we can merge BB into DestBB if there is a 206d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner/// single uncond branch between them, and BB contains no other non-phi 207d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner/// instructions. 208d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattnerbool CodeGenPrepare::CanMergeBlocks(const BasicBlock *BB, 209d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner const BasicBlock *DestBB) const { 210d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // We only want to eliminate blocks whose phi nodes are used by phi nodes in 211d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // the successor. If there are more complex condition (e.g. preheaders), 212d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // don't mess around with them. 213d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner BasicBlock::const_iterator BBI = BB->begin(); 214d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner while (const PHINode *PN = dyn_cast<PHINode>(BBI++)) { 21560ad781c61815ca5b8dc2a45a102e1c8af65992fGabor Greif for (Value::const_use_iterator UI = PN->use_begin(), E = PN->use_end(); 216d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner UI != E; ++UI) { 217d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner const Instruction *User = cast<Instruction>(*UI); 218d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner if (User->getParent() != DestBB || !isa<PHINode>(User)) 219d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner return false; 220692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher // If User is inside DestBB block and it is a PHINode then check 221692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher // incoming value. If incoming value is not from BB then this is 22275abc1ed0618048c3cf6c5b71c9868c10d6c1478Devang Patel // a complex condition (e.g. preheaders) we want to avoid here. 22375abc1ed0618048c3cf6c5b71c9868c10d6c1478Devang Patel if (User->getParent() == DestBB) { 22475abc1ed0618048c3cf6c5b71c9868c10d6c1478Devang Patel if (const PHINode *UPN = dyn_cast<PHINode>(User)) 22575abc1ed0618048c3cf6c5b71c9868c10d6c1478Devang Patel for (unsigned I = 0, E = UPN->getNumIncomingValues(); I != E; ++I) { 22675abc1ed0618048c3cf6c5b71c9868c10d6c1478Devang Patel Instruction *Insn = dyn_cast<Instruction>(UPN->getIncomingValue(I)); 22775abc1ed0618048c3cf6c5b71c9868c10d6c1478Devang Patel if (Insn && Insn->getParent() == BB && 22875abc1ed0618048c3cf6c5b71c9868c10d6c1478Devang Patel Insn->getParent() != UPN->getIncomingBlock(I)) 22975abc1ed0618048c3cf6c5b71c9868c10d6c1478Devang Patel return false; 23075abc1ed0618048c3cf6c5b71c9868c10d6c1478Devang Patel } 23175abc1ed0618048c3cf6c5b71c9868c10d6c1478Devang Patel } 232d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner } 233d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner } 234692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 235d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // If BB and DestBB contain any common predecessors, then the phi nodes in BB 236d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // and DestBB may have conflicting incoming values for the block. If so, we 237d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // can't merge the block. 238d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner const PHINode *DestBBPN = dyn_cast<PHINode>(DestBB->begin()); 239d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner if (!DestBBPN) return true; // no conflict. 240692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 241d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // Collect the preds of BB. 242f67f73a519eac94b6c1f98dbce7d251a3a4aea07Chris Lattner SmallPtrSet<const BasicBlock*, 16> BBPreds; 243d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner if (const PHINode *BBPN = dyn_cast<PHINode>(BB->begin())) { 244d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // It is faster to get preds from a PHI than with pred_iterator. 245d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner for (unsigned i = 0, e = BBPN->getNumIncomingValues(); i != e; ++i) 246d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner BBPreds.insert(BBPN->getIncomingBlock(i)); 247d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner } else { 248d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner BBPreds.insert(pred_begin(BB), pred_end(BB)); 249d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner } 250692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 251d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // Walk the preds of DestBB. 252d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner for (unsigned i = 0, e = DestBBPN->getNumIncomingValues(); i != e; ++i) { 253d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner BasicBlock *Pred = DestBBPN->getIncomingBlock(i); 254d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner if (BBPreds.count(Pred)) { // Common predecessor? 255d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner BBI = DestBB->begin(); 256d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner while (const PHINode *PN = dyn_cast<PHINode>(BBI++)) { 257d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner const Value *V1 = PN->getIncomingValueForBlock(Pred); 258d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner const Value *V2 = PN->getIncomingValueForBlock(BB); 259692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 260d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // If V2 is a phi node in BB, look up what the mapped value will be. 261d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner if (const PHINode *V2PN = dyn_cast<PHINode>(V2)) 262d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner if (V2PN->getParent() == BB) 263d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner V2 = V2PN->getIncomingValueForBlock(Pred); 264692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 265d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // If there is a conflict, bail out. 266d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner if (V1 != V2) return false; 267d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner } 268d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner } 269d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner } 270d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner 271d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner return true; 272d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner} 273d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner 274d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner 275d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner/// EliminateMostlyEmptyBlock - Eliminate a basic block that have only phi's and 276d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner/// an unconditional branch in it. 277d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattnervoid CodeGenPrepare::EliminateMostlyEmptyBlock(BasicBlock *BB) { 278d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner BranchInst *BI = cast<BranchInst>(BB->getTerminator()); 279d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner BasicBlock *DestBB = BI->getSuccessor(0); 280692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 28168d67fdf203ff2d5b0eeb925befd0866bce3aceeDavid Greene DEBUG(dbgs() << "MERGING MOSTLY EMPTY BLOCKS - BEFORE:\n" << *BB << *DestBB); 282692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 283d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // If the destination block has a single pred, then this is a trivial edge, 284d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // just collapse it. 2859918fb5631974f2201a640384b7ebe672c749e43Chris Lattner if (BasicBlock *SinglePred = DestBB->getSinglePredecessor()) { 286f5102a0f088e7c96f7028bf7ca1c24975c314fffChris Lattner if (SinglePred != DestBB) { 287f5102a0f088e7c96f7028bf7ca1c24975c314fffChris Lattner // Remember if SinglePred was the entry block of the function. If so, we 288f5102a0f088e7c96f7028bf7ca1c24975c314fffChris Lattner // will need to move BB back to the entry position. 289f5102a0f088e7c96f7028bf7ca1c24975c314fffChris Lattner bool isEntry = SinglePred == &SinglePred->getParent()->getEntryBlock(); 290ad80981a106c9d0ec83351e63ee3ac75ed646bf4Andreas Neustifter MergeBasicBlockIntoOnlyPred(DestBB, this); 291f5102a0f088e7c96f7028bf7ca1c24975c314fffChris Lattner 292f5102a0f088e7c96f7028bf7ca1c24975c314fffChris Lattner if (isEntry && BB != &BB->getParent()->getEntryBlock()) 293f5102a0f088e7c96f7028bf7ca1c24975c314fffChris Lattner BB->moveBefore(&BB->getParent()->getEntryBlock()); 294f5102a0f088e7c96f7028bf7ca1c24975c314fffChris Lattner 29568d67fdf203ff2d5b0eeb925befd0866bce3aceeDavid Greene DEBUG(dbgs() << "AFTER:\n" << *DestBB << "\n\n\n"); 296f5102a0f088e7c96f7028bf7ca1c24975c314fffChris Lattner return; 297f5102a0f088e7c96f7028bf7ca1c24975c314fffChris Lattner } 298d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner } 299692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 300d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // Otherwise, we have multiple predecessors of BB. Update the PHIs in DestBB 301d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // to handle the new incoming edges it is about to have. 302d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner PHINode *PN; 303d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner for (BasicBlock::iterator BBI = DestBB->begin(); 304d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner (PN = dyn_cast<PHINode>(BBI)); ++BBI) { 305d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // Remove the incoming value for BB, and remember it. 306d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner Value *InVal = PN->removeIncomingValue(BB, false); 307692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 308d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // Two options: either the InVal is a phi node defined in BB or it is some 309d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // value that dominates BB. 310d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner PHINode *InValPhi = dyn_cast<PHINode>(InVal); 311d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner if (InValPhi && InValPhi->getParent() == BB) { 312d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // Add all of the input values of the input PHI as inputs of this phi. 313d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner for (unsigned i = 0, e = InValPhi->getNumIncomingValues(); i != e; ++i) 314d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner PN->addIncoming(InValPhi->getIncomingValue(i), 315d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner InValPhi->getIncomingBlock(i)); 316d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner } else { 317d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // Otherwise, add one instance of the dominating value for each edge that 318d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // we will be adding. 319d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner if (PHINode *BBPN = dyn_cast<PHINode>(BB->begin())) { 320d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner for (unsigned i = 0, e = BBPN->getNumIncomingValues(); i != e; ++i) 321d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner PN->addIncoming(InVal, BBPN->getIncomingBlock(i)); 322d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner } else { 323d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) 324d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner PN->addIncoming(InVal, *PI); 325d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner } 326d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner } 327d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner } 328692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 329d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // The PHIs are now updated, change everything that refers to BB to use 330d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner // DestBB and remove BB. 331d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner BB->replaceAllUsesWith(DestBB); 33280f6a507d4e11ba066ad0e53e12ad25ad8cf07baCameron Zwarich if (DT) { 33380f6a507d4e11ba066ad0e53e12ad25ad8cf07baCameron Zwarich BasicBlock *BBIDom = DT->getNode(BB)->getIDom()->getBlock(); 33480f6a507d4e11ba066ad0e53e12ad25ad8cf07baCameron Zwarich BasicBlock *DestBBIDom = DT->getNode(DestBB)->getIDom()->getBlock(); 33580f6a507d4e11ba066ad0e53e12ad25ad8cf07baCameron Zwarich BasicBlock *NewIDom = DT->findNearestCommonDominator(BBIDom, DestBBIDom); 33680f6a507d4e11ba066ad0e53e12ad25ad8cf07baCameron Zwarich DT->changeImmediateDominator(DestBB, NewIDom); 33780f6a507d4e11ba066ad0e53e12ad25ad8cf07baCameron Zwarich DT->eraseNode(BB); 33880f6a507d4e11ba066ad0e53e12ad25ad8cf07baCameron Zwarich } 33904149f7ffd033773adfe85e4acf3f560e29bd47dEvan Cheng if (PFI) { 34004149f7ffd033773adfe85e4acf3f560e29bd47dEvan Cheng PFI->replaceAllUses(BB, DestBB); 34104149f7ffd033773adfe85e4acf3f560e29bd47dEvan Cheng PFI->removeEdge(ProfileInfo::getEdge(BB, DestBB)); 342ad80981a106c9d0ec83351e63ee3ac75ed646bf4Andreas Neustifter } 343d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner BB->eraseFromParent(); 34431ff1333e0651192212cee6e090df2ff57d19b53Cameron Zwarich ++NumBlocksElim; 345692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 34668d67fdf203ff2d5b0eeb925befd0866bce3aceeDavid Greene DEBUG(dbgs() << "AFTER:\n" << *DestBB << "\n\n\n"); 347d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner} 348d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner 34998d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner/// FindReusablePredBB - Check all of the predecessors of the block DestPHI 35098d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner/// lives in to see if there is a block that we can reuse as a critical edge 35198d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner/// from TIBB. 35298d5c3141eddc84a8bcf7db57332967695585e42Chris Lattnerstatic BasicBlock *FindReusablePredBB(PHINode *DestPHI, BasicBlock *TIBB) { 35398d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner BasicBlock *Dest = DestPHI->getParent(); 35498d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner 35598d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner /// TIPHIValues - This array is lazily computed to determine the values of 35698d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner /// PHIs in Dest that TI would provide. 35798d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner SmallVector<Value*, 32> TIPHIValues; 35898d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner 35998d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner /// TIBBEntryNo - This is a cache to speed up pred queries for TIBB. 36098d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner unsigned TIBBEntryNo = 0; 36198d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner 36298d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner // Check to see if Dest has any blocks that can be used as a split edge for 36398d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner // this terminator. 36498d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner for (unsigned pi = 0, e = DestPHI->getNumIncomingValues(); pi != e; ++pi) { 36598d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner BasicBlock *Pred = DestPHI->getIncomingBlock(pi); 36698d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner // To be usable, the pred has to end with an uncond branch to the dest. 36798d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner BranchInst *PredBr = dyn_cast<BranchInst>(Pred->getTerminator()); 36898d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner if (!PredBr || !PredBr->isUnconditional()) 36998d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner continue; 37098d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner // Must be empty other than the branch and debug info. 37198d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner BasicBlock::iterator I = Pred->begin(); 37298d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner while (isa<DbgInfoIntrinsic>(I)) 37398d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner I++; 37498d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner if (&*I != PredBr) 37598d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner continue; 37698d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner // Cannot be the entry block; its label does not get emitted. 37798d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner if (Pred == &Dest->getParent()->getEntryBlock()) 37898d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner continue; 37998d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner 38098d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner // Finally, since we know that Dest has phi nodes in it, we have to make 38198d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner // sure that jumping to Pred will have the same effect as going to Dest in 38298d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner // terms of PHI values. 38398d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner PHINode *PN; 38498d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner unsigned PHINo = 0; 38598d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner unsigned PredEntryNo = pi; 38698d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner 38798d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner bool FoundMatch = true; 38898d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner for (BasicBlock::iterator I = Dest->begin(); 38998d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner (PN = dyn_cast<PHINode>(I)); ++I, ++PHINo) { 39098d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner if (PHINo == TIPHIValues.size()) { 39198d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner if (PN->getIncomingBlock(TIBBEntryNo) != TIBB) 39298d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner TIBBEntryNo = PN->getBasicBlockIndex(TIBB); 39398d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner TIPHIValues.push_back(PN->getIncomingValue(TIBBEntryNo)); 39498d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner } 39598d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner 39698d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner // If the PHI entry doesn't work, we can't use this pred. 39798d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner if (PN->getIncomingBlock(PredEntryNo) != Pred) 39898d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner PredEntryNo = PN->getBasicBlockIndex(Pred); 39998d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner 40098d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner if (TIPHIValues[PHINo] != PN->getIncomingValue(PredEntryNo)) { 40198d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner FoundMatch = false; 40298d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner break; 40398d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner } 40498d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner } 40598d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner 40698d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner // If we found a workable predecessor, change TI to branch to Succ. 40798d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner if (FoundMatch) 40898d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner return Pred; 40998d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner } 41098d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner return 0; 41198d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner} 41298d5c3141eddc84a8bcf7db57332967695585e42Chris Lattner 413d9c3a0d7cce72ac802516483c4a325b3b31bbc0eChris Lattner 414ebe807597f3ee67f6c5f9cd462ba325b579a2680Chris Lattner/// SplitEdgeNicely - Split the critical edge from TI to its specified 415dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner/// successor if it will improve codegen. We only do this if the successor has 416dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner/// phi nodes (otherwise critical edges are ok). If there is already another 417dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner/// predecessor of the succ that is empty (and thus has no phi nodes), use it 418dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner/// instead of introducing a new block. 419ab63152871f4144050d0a58d592a95e089fe40d4Evan Chengstatic void SplitEdgeNicely(TerminatorInst *TI, unsigned SuccNum, 420fe095f39e7009c51d1c86769792ccbcad8cdd2ecMike Stump SmallSet<std::pair<const BasicBlock*, 421fe095f39e7009c51d1c86769792ccbcad8cdd2ecMike Stump const BasicBlock*>, 8> &BackEdges, 422ab63152871f4144050d0a58d592a95e089fe40d4Evan Cheng Pass *P) { 423dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner BasicBlock *TIBB = TI->getParent(); 424dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner BasicBlock *Dest = TI->getSuccessor(SuccNum); 425dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner assert(isa<PHINode>(Dest->begin()) && 426dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner "This should only be called if Dest has a PHI!"); 4273f65b5e733e01faeb9db825515ca00e544fb988aChris Lattner PHINode *DestPHI = cast<PHINode>(Dest->begin()); 428692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 429fc0b80d9746e5fd4b45057ab814c67371fb0f9eaEvan Cheng // Do not split edges to EH landing pads. 4303f65b5e733e01faeb9db825515ca00e544fb988aChris Lattner if (InvokeInst *Invoke = dyn_cast<InvokeInst>(TI)) 431fc0b80d9746e5fd4b45057ab814c67371fb0f9eaEvan Cheng if (Invoke->getSuccessor(1) == Dest) 432fc0b80d9746e5fd4b45057ab814c67371fb0f9eaEvan Cheng return; 433fc0b80d9746e5fd4b45057ab814c67371fb0f9eaEvan Cheng 434ebe807597f3ee67f6c5f9cd462ba325b579a2680Chris Lattner // As a hack, never split backedges of loops. Even though the copy for any 435ebe807597f3ee67f6c5f9cd462ba325b579a2680Chris Lattner // PHIs inserted on the backedge would be dead for exits from the loop, we 436ebe807597f3ee67f6c5f9cd462ba325b579a2680Chris Lattner // assume that the cost of *splitting* the backedge would be too high. 437ab63152871f4144050d0a58d592a95e089fe40d4Evan Cheng if (BackEdges.count(std::make_pair(TIBB, Dest))) 438ebe807597f3ee67f6c5f9cd462ba325b579a2680Chris Lattner return; 439692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 440c09687bb7ea35e0dc9d709460c83a58e6076e4d2Chris Lattner if (BasicBlock *ReuseBB = FindReusablePredBB(DestPHI, TIBB)) { 441c09687bb7ea35e0dc9d709460c83a58e6076e4d2Chris Lattner ProfileInfo *PFI = P->getAnalysisIfAvailable<ProfileInfo>(); 442c09687bb7ea35e0dc9d709460c83a58e6076e4d2Chris Lattner if (PFI) 443c09687bb7ea35e0dc9d709460c83a58e6076e4d2Chris Lattner PFI->splitEdge(TIBB, Dest, ReuseBB); 444c09687bb7ea35e0dc9d709460c83a58e6076e4d2Chris Lattner Dest->removePredecessor(TIBB); 445c09687bb7ea35e0dc9d709460c83a58e6076e4d2Chris Lattner TI->setSuccessor(SuccNum, ReuseBB); 446ab63152871f4144050d0a58d592a95e089fe40d4Evan Cheng return; 447ab63152871f4144050d0a58d592a95e089fe40d4Evan Cheng } 448ab63152871f4144050d0a58d592a95e089fe40d4Evan Cheng 449c09687bb7ea35e0dc9d709460c83a58e6076e4d2Chris Lattner SplitCriticalEdge(TI, SuccNum, P, true); 450dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner} 451dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner 452ab63152871f4144050d0a58d592a95e089fe40d4Evan Cheng 453dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner/// OptimizeNoopCopyExpression - If the specified cast instruction is a noop 454a119de86a064414622562cfe32953de7f9b0ee40Dan Gohman/// copy (e.g. it's casting from one pointer type to another, i32->i8 on PPC), 455a119de86a064414622562cfe32953de7f9b0ee40Dan Gohman/// sink it into user blocks to reduce the number of virtual 456ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen/// registers that must be created and coalesced. 457dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner/// 458dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner/// Return true if any changes are made. 45985fa13c02d383bb87dd9b8b9081a4d34a3e9c52cChris Lattner/// 460dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattnerstatic bool OptimizeNoopCopyExpression(CastInst *CI, const TargetLowering &TLI){ 461692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher // If this is a noop copy, 462e50ed30282bb5b4a9ed952580523f2dda16215acOwen Anderson EVT SrcVT = TLI.getValueType(CI->getOperand(0)->getType()); 463e50ed30282bb5b4a9ed952580523f2dda16215acOwen Anderson EVT DstVT = TLI.getValueType(CI->getType()); 464692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 465dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // This is an fp<->int conversion? 46683ec4b6711980242ef3c55a4fa36b2d7a39c1bfbDuncan Sands if (SrcVT.isInteger() != DstVT.isInteger()) 467dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner return false; 4688e4eb09b1e3571965f49edcdfb56b1375b1b7551Duncan Sands 469dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // If this is an extension, it will be a zero or sign extension, which 470dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // isn't a noop. 4718e4eb09b1e3571965f49edcdfb56b1375b1b7551Duncan Sands if (SrcVT.bitsLT(DstVT)) return false; 472692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 473dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // If these values will be promoted, find out what they will be promoted 474dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // to. This helps us consider truncates on PPC as noop copies when they 475dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // are. 476aafe626c7fa9f99150cccd27d0151a2cf7c8c00bChris Lattner if (TLI.getTypeAction(SrcVT) == TargetLowering::Promote) 47723b9b19b1a5a00faa9fce0788155c7dbfd00bfb1Owen Anderson SrcVT = TLI.getTypeToTransformTo(CI->getContext(), SrcVT); 478aafe626c7fa9f99150cccd27d0151a2cf7c8c00bChris Lattner if (TLI.getTypeAction(DstVT) == TargetLowering::Promote) 47923b9b19b1a5a00faa9fce0788155c7dbfd00bfb1Owen Anderson DstVT = TLI.getTypeToTransformTo(CI->getContext(), DstVT); 480692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 481dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // If, after promotion, these are the same types, this is a noop copy. 482dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner if (SrcVT != DstVT) 483dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner return false; 484692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 485dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner BasicBlock *DefBB = CI->getParent(); 486692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 487dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner /// InsertedCasts - Only insert a cast in each block once. 488ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen DenseMap<BasicBlock*, CastInst*> InsertedCasts; 489692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 490dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner bool MadeChange = false; 491692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher for (Value::use_iterator UI = CI->use_begin(), E = CI->use_end(); 492dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner UI != E; ) { 493dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner Use &TheUse = UI.getUse(); 494dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner Instruction *User = cast<Instruction>(*UI); 495692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 496dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner // Figure out which BB this cast is used in. For PHI's this is the 497dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner // appropriate predecessor block. 498dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner BasicBlock *UserBB = User->getParent(); 499dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner if (PHINode *PN = dyn_cast<PHINode>(User)) { 500a36791da41cf4f635e50077b290676b873836bdaGabor Greif UserBB = PN->getIncomingBlock(UI); 501dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner } 502692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 503dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner // Preincrement use iterator so we don't invalidate it. 504dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner ++UI; 505692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 506dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner // If this user is in the same block as the cast, don't change the cast. 507dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner if (UserBB == DefBB) continue; 508692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 509dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner // If we have already inserted a cast into this block, use it. 510dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner CastInst *&InsertedCast = InsertedCasts[UserBB]; 511dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner 512dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner if (!InsertedCast) { 51302dea8b39f3acad5de1df36273444d149145e7fcDan Gohman BasicBlock::iterator InsertPt = UserBB->getFirstNonPHI(); 514692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 515692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher InsertedCast = 516692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher CastInst::Create(CI->getOpcode(), CI->getOperand(0), CI->getType(), "", 517dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner InsertPt); 518dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner MadeChange = true; 519dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner } 520692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 521ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen // Replace a use of the cast with a use of the new cast. 522dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner TheUse = InsertedCast; 52331ff1333e0651192212cee6e090df2ff57d19b53Cameron Zwarich ++NumCastUses; 524dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner } 525692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 526dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner // If we removed all uses, nuke the cast. 527e003813e9613f41ff2c6a10cb1d3ae3a5b8eab1fDuncan Sands if (CI->use_empty()) { 528dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner CI->eraseFromParent(); 529e003813e9613f41ff2c6a10cb1d3ae3a5b8eab1fDuncan Sands MadeChange = true; 530e003813e9613f41ff2c6a10cb1d3ae3a5b8eab1fDuncan Sands } 531692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 532dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner return MadeChange; 533dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner} 534dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner 535692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher/// OptimizeCmpExpression - sink the given CmpInst into user blocks to reduce 536ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen/// the number of virtual registers that must be created and coalesced. This is 537684b22df79c51114a12289e10a4063d5f02259a9Chris Lattner/// a clear win except on targets with multiple condition code registers 538684b22df79c51114a12289e10a4063d5f02259a9Chris Lattner/// (PowerPC), where it might lose; some adjustment may be wanted there. 539ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen/// 540ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen/// Return true if any changes are made. 54185fa13c02d383bb87dd9b8b9081a4d34a3e9c52cChris Lattnerstatic bool OptimizeCmpExpression(CmpInst *CI) { 542ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen BasicBlock *DefBB = CI->getParent(); 543692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 544ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen /// InsertedCmp - Only insert a cmp in each block once. 545ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen DenseMap<BasicBlock*, CmpInst*> InsertedCmps; 546692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 547ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen bool MadeChange = false; 548692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher for (Value::use_iterator UI = CI->use_begin(), E = CI->use_end(); 549ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen UI != E; ) { 550ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen Use &TheUse = UI.getUse(); 551ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen Instruction *User = cast<Instruction>(*UI); 552692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 553ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen // Preincrement use iterator so we don't invalidate it. 554ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen ++UI; 555692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 556ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen // Don't bother for PHI nodes. 557ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen if (isa<PHINode>(User)) 558ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen continue; 559ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen 560ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen // Figure out which BB this cmp is used in. 561ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen BasicBlock *UserBB = User->getParent(); 562692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 563ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen // If this user is in the same block as the cmp, don't change the cmp. 564ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen if (UserBB == DefBB) continue; 565692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 566ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen // If we have already inserted a cmp into this block, use it. 567ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen CmpInst *&InsertedCmp = InsertedCmps[UserBB]; 568ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen 569ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen if (!InsertedCmp) { 57002dea8b39f3acad5de1df36273444d149145e7fcDan Gohman BasicBlock::iterator InsertPt = UserBB->getFirstNonPHI(); 571692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 572692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher InsertedCmp = 5731c8a23c440b1665ba422778cdc74a0c59ecaf39eDan Gohman CmpInst::Create(CI->getOpcode(), 574333c40096561218bc3597cf153c0a3895274414cOwen Anderson CI->getPredicate(), CI->getOperand(0), 575ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen CI->getOperand(1), "", InsertPt); 576ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen MadeChange = true; 577ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen } 578692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 579ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen // Replace a use of the cmp with a use of the new cmp. 580ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen TheUse = InsertedCmp; 58131ff1333e0651192212cee6e090df2ff57d19b53Cameron Zwarich ++NumCmpUses; 582ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen } 583692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 584ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen // If we removed all uses, nuke the cmp. 585ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen if (CI->use_empty()) 586ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen CI->eraseFromParent(); 587692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 588ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen return MadeChange; 589ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen} 590ce0b23721e434789f9600c0fd13f0ca17444264fDale Johannesen 5910b6cb507385c8bd10b6a51b5e45a9b99d8d94798Benjamin Kramernamespace { 5920b6cb507385c8bd10b6a51b5e45a9b99d8d94798Benjamin Kramerclass CodeGenPrepareFortifiedLibCalls : public SimplifyFortifiedLibCalls { 5930b6cb507385c8bd10b6a51b5e45a9b99d8d94798Benjamin Kramerprotected: 5940b6cb507385c8bd10b6a51b5e45a9b99d8d94798Benjamin Kramer void replaceCall(Value *With) { 5950b6cb507385c8bd10b6a51b5e45a9b99d8d94798Benjamin Kramer CI->replaceAllUsesWith(With); 5960b6cb507385c8bd10b6a51b5e45a9b99d8d94798Benjamin Kramer CI->eraseFromParent(); 5970b6cb507385c8bd10b6a51b5e45a9b99d8d94798Benjamin Kramer } 5980b6cb507385c8bd10b6a51b5e45a9b99d8d94798Benjamin Kramer bool isFoldable(unsigned SizeCIOp, unsigned, bool) const { 599a6aac4c5bc22bb10c7adb11eee3f82c703af7002Gabor Greif if (ConstantInt *SizeCI = 600a6aac4c5bc22bb10c7adb11eee3f82c703af7002Gabor Greif dyn_cast<ConstantInt>(CI->getArgOperand(SizeCIOp))) 601a6aac4c5bc22bb10c7adb11eee3f82c703af7002Gabor Greif return SizeCI->isAllOnesValue(); 6020b6cb507385c8bd10b6a51b5e45a9b99d8d94798Benjamin Kramer return false; 6030b6cb507385c8bd10b6a51b5e45a9b99d8d94798Benjamin Kramer } 6040b6cb507385c8bd10b6a51b5e45a9b99d8d94798Benjamin Kramer}; 6050b6cb507385c8bd10b6a51b5e45a9b99d8d94798Benjamin Kramer} // end anonymous namespace 6060b6cb507385c8bd10b6a51b5e45a9b99d8d94798Benjamin Kramer 607040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopherbool CodeGenPrepare::OptimizeCallInst(CallInst *CI) { 608040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher // Lower all uses of llvm.objectsize.* 609040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI); 610040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher if (II && II->getIntrinsicID() == Intrinsic::objectsize) { 611de9f5452d3ae894bb7fdd455cec5af50e2560aa5Gabor Greif bool Min = (cast<ConstantInt>(II->getArgOperand(1))->getZExtValue() == 1); 612040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher const Type *ReturnTy = CI->getType(); 613040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher Constant *RetVal = ConstantInt::get(ReturnTy, Min ? 0 : -1ULL); 614040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher CI->replaceAllUsesWith(RetVal); 615040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher CI->eraseFromParent(); 616040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher return true; 617040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher } 618040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher 619040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher // From here on out we're working with named functions. 620040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher if (CI->getCalledFunction() == 0) return false; 621040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher 622040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher // We'll need TargetData from here on out. 623040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher const TargetData *TD = TLI ? TLI->getTargetData() : 0; 624040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher if (!TD) return false; 625040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher 6260b6cb507385c8bd10b6a51b5e45a9b99d8d94798Benjamin Kramer // Lower all default uses of _chk calls. This is very similar 6270b6cb507385c8bd10b6a51b5e45a9b99d8d94798Benjamin Kramer // to what InstCombineCalls does, but here we are only lowering calls 628040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher // that have the default "don't know" as the objectsize. Anything else 629040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher // should be left alone. 6300b6cb507385c8bd10b6a51b5e45a9b99d8d94798Benjamin Kramer CodeGenPrepareFortifiedLibCalls Simplifier; 6310b6cb507385c8bd10b6a51b5e45a9b99d8d94798Benjamin Kramer return Simplifier.fold(CI, TD); 632040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher} 63388a5c832ac71eb31d2b1bc143817af9248f4c549Chris Lattner//===----------------------------------------------------------------------===// 63488a5c832ac71eb31d2b1bc143817af9248f4c549Chris Lattner// Memory Optimization 63588a5c832ac71eb31d2b1bc143817af9248f4c549Chris Lattner//===----------------------------------------------------------------------===// 63688a5c832ac71eb31d2b1bc143817af9248f4c549Chris Lattner 637dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner/// IsNonLocalValue - Return true if the specified values are defined in a 638dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner/// different basic block than BB. 639dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattnerstatic bool IsNonLocalValue(Value *V, BasicBlock *BB) { 640dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner if (Instruction *I = dyn_cast<Instruction>(V)) 641dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner return I->getParent() != BB; 642dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner return false; 643dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner} 644dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner 6454a8ee23a8181f668dc294b417f67e1675ad391abBob Wilson/// OptimizeMemoryInst - Load and Store Instructions often have 646dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner/// addressing modes that can do significant amounts of computation. As such, 647dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner/// instruction selection will try to get the load or store to do as much 648dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner/// computation as possible for the program. The problem is that isel can only 649dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner/// see within a single block. As such, we sink as much legal addressing mode 650dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner/// stuff into the block as possible. 65188a5c832ac71eb31d2b1bc143817af9248f4c549Chris Lattner/// 65288a5c832ac71eb31d2b1bc143817af9248f4c549Chris Lattner/// This method is used to optimize both load/store and inline asms with memory 65388a5c832ac71eb31d2b1bc143817af9248f4c549Chris Lattner/// operands. 654896617b776e7b015346160645b19be776cbe3805Chris Lattnerbool CodeGenPrepare::OptimizeMemoryInst(Instruction *MemoryInst, Value *Addr, 65588a5c832ac71eb31d2b1bc143817af9248f4c549Chris Lattner const Type *AccessTy, 65688a5c832ac71eb31d2b1bc143817af9248f4c549Chris Lattner DenseMap<Value*,Value*> &SunkAddrs) { 65735bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson Value *Repl = Addr; 65835bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson 659d2f4174fcc69a3328076734fa3256b31e5b7f734Owen Anderson // Try to collapse single-value PHI nodes. This is necessary to undo 660d2f4174fcc69a3328076734fa3256b31e5b7f734Owen Anderson // unprofitable PRE transformations. 6617cb4fa20b5534decf527a6bfcc74bd79ea11cbb1Cameron Zwarich SmallVector<Value*, 8> worklist; 6627cb4fa20b5534decf527a6bfcc74bd79ea11cbb1Cameron Zwarich SmallPtrSet<Value*, 16> Visited; 66335bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson worklist.push_back(Addr); 66435bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson 66535bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson // Use a worklist to iteratively look through PHI nodes, and ensure that 66635bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson // the addressing mode obtained from the non-PHI roots of the graph 66735bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson // are equivalent. 66835bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson Value *Consensus = 0; 66935bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson unsigned NumUses = 0; 67035bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson SmallVector<Instruction*, 16> AddrModeInsts; 67135bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson ExtAddrMode AddrMode; 67235bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson while (!worklist.empty()) { 67335bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson Value *V = worklist.back(); 67435bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson worklist.pop_back(); 67535bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson 67635bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson // Break use-def graph loops. 67735bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson if (Visited.count(V)) { 67835bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson Consensus = 0; 67935bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson break; 68035bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson } 68135bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson 68235bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson Visited.insert(V); 68335bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson 68435bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson // For a PHI node, push all of its incoming values. 68535bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson if (PHINode *P = dyn_cast<PHINode>(V)) { 68635bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson for (unsigned i = 0, e = P->getNumIncomingValues(); i != e; ++i) 68735bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson worklist.push_back(P->getIncomingValue(i)); 68835bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson continue; 68935bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson } 69035bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson 69135bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson // For non-PHIs, determine the addressing mode being computed. 69235bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson SmallVector<Instruction*, 16> NewAddrModeInsts; 69335bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson ExtAddrMode NewAddrMode = 69435bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson AddressingModeMatcher::Match(V, AccessTy,MemoryInst, 69535bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson NewAddrModeInsts, *TLI); 69635bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson 69735bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson // Ensure that the obtained addressing mode is equivalent to that obtained 69835bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson // for all other roots of the PHI traversal. Also, when choosing one 69935bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson // such root as representative, select the one with the most uses in order 70035bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson // to keep the cost modeling heuristics in AddressingModeMatcher applicable. 70135bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson if (!Consensus || NewAddrMode == AddrMode) { 70235bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson if (V->getNumUses() > NumUses) { 70335bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson Consensus = V; 70435bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson NumUses = V->getNumUses(); 70535bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson AddrMode = NewAddrMode; 70635bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson AddrModeInsts = NewAddrModeInsts; 707d2f4174fcc69a3328076734fa3256b31e5b7f734Owen Anderson } 70835bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson continue; 709d2f4174fcc69a3328076734fa3256b31e5b7f734Owen Anderson } 710d2f4174fcc69a3328076734fa3256b31e5b7f734Owen Anderson 71135bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson Consensus = 0; 71235bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson break; 713d2f4174fcc69a3328076734fa3256b31e5b7f734Owen Anderson } 714d2f4174fcc69a3328076734fa3256b31e5b7f734Owen Anderson 71535bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson // If the addressing mode couldn't be determined, or if multiple different 71635bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson // ones were determined, bail out now. 71735bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson if (!Consensus) return false; 71835bf4d6d8018160557a92b86181acbcef76f86ebOwen Anderson 719dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // Check to see if any of the instructions supersumed by this addr mode are 720dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // non-local to I's BB. 721dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner bool AnyNonLocal = false; 722dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner for (unsigned i = 0, e = AddrModeInsts.size(); i != e; ++i) { 723896617b776e7b015346160645b19be776cbe3805Chris Lattner if (IsNonLocalValue(AddrModeInsts[i], MemoryInst->getParent())) { 724dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner AnyNonLocal = true; 725dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner break; 726dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner } 727dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner } 728692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 729dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // If all the instructions matched are already in this BB, don't do anything. 730dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner if (!AnyNonLocal) { 73168d67fdf203ff2d5b0eeb925befd0866bce3aceeDavid Greene DEBUG(dbgs() << "CGP: Found local addrmode: " << AddrMode << "\n"); 732dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner return false; 733dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner } 734692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 735dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // Insert this computation right after this user. Since our caller is 736dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // scanning from the top of the BB to the bottom, reuse of the expr are 737dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // guaranteed to happen later. 738896617b776e7b015346160645b19be776cbe3805Chris Lattner BasicBlock::iterator InsertPt = MemoryInst; 739692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 740dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // Now that we determined the addressing expression we want to use and know 741dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // that we have to sink it into this block. Check to see if we have already 742dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // done this for some other load/store instr in this block. If so, reuse the 743dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // computation. 744dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner Value *&SunkAddr = SunkAddrs[Addr]; 745dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner if (SunkAddr) { 74668d67fdf203ff2d5b0eeb925befd0866bce3aceeDavid Greene DEBUG(dbgs() << "CGP: Reusing nonlocal addrmode: " << AddrMode << " for " 7476c1980b3357207c4d756255bc5e32323eac278dcDan Gohman << *MemoryInst); 748dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner if (SunkAddr->getType() != Addr->getType()) 749dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner SunkAddr = new BitCastInst(SunkAddr, Addr->getType(), "tmp", InsertPt); 750dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner } else { 75168d67fdf203ff2d5b0eeb925befd0866bce3aceeDavid Greene DEBUG(dbgs() << "CGP: SINKING nonlocal addrmode: " << AddrMode << " for " 7526c1980b3357207c4d756255bc5e32323eac278dcDan Gohman << *MemoryInst); 7531d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson const Type *IntPtrTy = 7541d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson TLI->getTargetData()->getIntPtrType(AccessTy->getContext()); 755692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 756dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner Value *Result = 0; 757d8d0b6a42c09f1c5b00a4e7029b08074a3da5acdDan Gohman 758d8d0b6a42c09f1c5b00a4e7029b08074a3da5acdDan Gohman // Start with the base register. Do this first so that subsequent address 759d8d0b6a42c09f1c5b00a4e7029b08074a3da5acdDan Gohman // matching finds it last, which will prevent it from trying to match it 760d8d0b6a42c09f1c5b00a4e7029b08074a3da5acdDan Gohman // as the scaled value in case it happens to be a mul. That would be 761d8d0b6a42c09f1c5b00a4e7029b08074a3da5acdDan Gohman // problematic if we've sunk a different mul for the scale, because then 762d8d0b6a42c09f1c5b00a4e7029b08074a3da5acdDan Gohman // we'd end up sinking both muls. 763d8d0b6a42c09f1c5b00a4e7029b08074a3da5acdDan Gohman if (AddrMode.BaseReg) { 764d8d0b6a42c09f1c5b00a4e7029b08074a3da5acdDan Gohman Value *V = AddrMode.BaseReg; 7651df9859c40492511b8aa4321eb76496005d3b75bDuncan Sands if (V->getType()->isPointerTy()) 766d8d0b6a42c09f1c5b00a4e7029b08074a3da5acdDan Gohman V = new PtrToIntInst(V, IntPtrTy, "sunkaddr", InsertPt); 767d8d0b6a42c09f1c5b00a4e7029b08074a3da5acdDan Gohman if (V->getType() != IntPtrTy) 768d8d0b6a42c09f1c5b00a4e7029b08074a3da5acdDan Gohman V = CastInst::CreateIntegerCast(V, IntPtrTy, /*isSigned=*/true, 769d8d0b6a42c09f1c5b00a4e7029b08074a3da5acdDan Gohman "sunkaddr", InsertPt); 770d8d0b6a42c09f1c5b00a4e7029b08074a3da5acdDan Gohman Result = V; 771d8d0b6a42c09f1c5b00a4e7029b08074a3da5acdDan Gohman } 772d8d0b6a42c09f1c5b00a4e7029b08074a3da5acdDan Gohman 773d8d0b6a42c09f1c5b00a4e7029b08074a3da5acdDan Gohman // Add the scale value. 774dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner if (AddrMode.Scale) { 775dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner Value *V = AddrMode.ScaledReg; 776dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner if (V->getType() == IntPtrTy) { 777dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // done. 7781df9859c40492511b8aa4321eb76496005d3b75bDuncan Sands } else if (V->getType()->isPointerTy()) { 779dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner V = new PtrToIntInst(V, IntPtrTy, "sunkaddr", InsertPt); 780dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner } else if (cast<IntegerType>(IntPtrTy)->getBitWidth() < 781dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner cast<IntegerType>(V->getType())->getBitWidth()) { 782dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner V = new TruncInst(V, IntPtrTy, "sunkaddr", InsertPt); 783dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner } else { 784dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner V = new SExtInst(V, IntPtrTy, "sunkaddr", InsertPt); 785dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner } 786dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner if (AddrMode.Scale != 1) 787eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson V = BinaryOperator::CreateMul(V, ConstantInt::get(IntPtrTy, 788d672ecb0178c6247a5eaa5b0fb0c3b23cd25bd7cOwen Anderson AddrMode.Scale), 789dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner "sunkaddr", InsertPt); 790dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner if (Result) 7917cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif Result = BinaryOperator::CreateAdd(Result, V, "sunkaddr", InsertPt); 792dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner else 793dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner Result = V; 794dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner } 795692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 796dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // Add in the BaseGV if present. 797dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner if (AddrMode.BaseGV) { 798dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner Value *V = new PtrToIntInst(AddrMode.BaseGV, IntPtrTy, "sunkaddr", 799dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner InsertPt); 800dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner if (Result) 8017cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif Result = BinaryOperator::CreateAdd(Result, V, "sunkaddr", InsertPt); 802dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner else 803dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner Result = V; 804dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner } 805692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 806dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // Add in the Base Offset if present. 807dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner if (AddrMode.BaseOffs) { 808eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson Value *V = ConstantInt::get(IntPtrTy, AddrMode.BaseOffs); 809dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner if (Result) 8107cbd8a3e92221437048b484d5ef9c0a22d0f8c58Gabor Greif Result = BinaryOperator::CreateAdd(Result, V, "sunkaddr", InsertPt); 811dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner else 812dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner Result = V; 813dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner } 814dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner 815dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner if (Result == 0) 816a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson SunkAddr = Constant::getNullValue(Addr->getType()); 817dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner else 818dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner SunkAddr = new IntToPtrInst(Result, Addr->getType(), "sunkaddr",InsertPt); 819dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner } 820692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 821d2f4174fcc69a3328076734fa3256b31e5b7f734Owen Anderson MemoryInst->replaceUsesOfWith(Repl, SunkAddr); 822692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 823d2f4174fcc69a3328076734fa3256b31e5b7f734Owen Anderson if (Repl->use_empty()) { 824d2f4174fcc69a3328076734fa3256b31e5b7f734Owen Anderson RecursivelyDeleteTriviallyDeadInstructions(Repl); 825536d31b5b391ee76eae33f4756f6442bf10b2d72Dale Johannesen // This address is now available for reassignment, so erase the table entry; 826536d31b5b391ee76eae33f4756f6442bf10b2d72Dale Johannesen // we don't want to match some completely different instruction. 827536d31b5b391ee76eae33f4756f6442bf10b2d72Dale Johannesen SunkAddrs[Addr] = 0; 828536d31b5b391ee76eae33f4756f6442bf10b2d72Dale Johannesen } 82931ff1333e0651192212cee6e090df2ff57d19b53Cameron Zwarich ++NumMemoryInsts; 830dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner return true; 831dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner} 832dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner 8339bf12b5583104c810cfadcdce91edf9efad79973Evan Cheng/// OptimizeInlineAsmInst - If there are any memory operands, use 83488a5c832ac71eb31d2b1bc143817af9248f4c549Chris Lattner/// OptimizeMemoryInst to sink their address computing into the block when 8359bf12b5583104c810cfadcdce91edf9efad79973Evan Cheng/// possible / profitable. 8369bf12b5583104c810cfadcdce91edf9efad79973Evan Chengbool CodeGenPrepare::OptimizeInlineAsmInst(Instruction *I, CallSite CS, 8379bf12b5583104c810cfadcdce91edf9efad79973Evan Cheng DenseMap<Value*,Value*> &SunkAddrs) { 8389bf12b5583104c810cfadcdce91edf9efad79973Evan Cheng bool MadeChange = false; 8399bf12b5583104c810cfadcdce91edf9efad79973Evan Cheng 84044ab89eb376af838d1123293a79975aede501464John Thompson TargetLowering::AsmOperandInfoVector TargetConstraints = TLI->ParseConstraints(CS); 841677c6ecd0804c247eb727a830b50cd6537a6c12cDale Johannesen unsigned ArgNo = 0; 842eac6e1d0c748afc3d1496be0753ffbe5f5a4279bJohn Thompson for (unsigned i = 0, e = TargetConstraints.size(); i != e; ++i) { 843eac6e1d0c748afc3d1496be0753ffbe5f5a4279bJohn Thompson TargetLowering::AsmOperandInfo &OpInfo = TargetConstraints[i]; 844eac6e1d0c748afc3d1496be0753ffbe5f5a4279bJohn Thompson 8459bf12b5583104c810cfadcdce91edf9efad79973Evan Cheng // Compute the constraint code and ConstraintType to use. 8461784d160e4efa75782884d451d0788b9457e67dcDale Johannesen TLI->ComputeConstraintToUse(OpInfo, SDValue()); 8479bf12b5583104c810cfadcdce91edf9efad79973Evan Cheng 8489ec8095485c994522c9a50e16fc029de94c20476Eli Friedman if (OpInfo.ConstraintType == TargetLowering::C_Memory && 8499ec8095485c994522c9a50e16fc029de94c20476Eli Friedman OpInfo.isIndirect) { 850677c6ecd0804c247eb727a830b50cd6537a6c12cDale Johannesen Value *OpVal = const_cast<Value *>(CS.getArgument(ArgNo++)); 85188a5c832ac71eb31d2b1bc143817af9248f4c549Chris Lattner MadeChange |= OptimizeMemoryInst(I, OpVal, OpVal->getType(), SunkAddrs); 852677c6ecd0804c247eb727a830b50cd6537a6c12cDale Johannesen } else if (OpInfo.Type == InlineAsm::isInput) 853677c6ecd0804c247eb727a830b50cd6537a6c12cDale Johannesen ArgNo++; 8549bf12b5583104c810cfadcdce91edf9efad79973Evan Cheng } 8559bf12b5583104c810cfadcdce91edf9efad79973Evan Cheng 8569bf12b5583104c810cfadcdce91edf9efad79973Evan Cheng return MadeChange; 8579bf12b5583104c810cfadcdce91edf9efad79973Evan Cheng} 8589bf12b5583104c810cfadcdce91edf9efad79973Evan Cheng 859b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman/// MoveExtToFormExtLoad - Move a zext or sext fed by a load into the same 860b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman/// basic block as the load, unless conditions are unfavorable. This allows 861b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman/// SelectionDAG to fold the extend into the load. 862b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman/// 863b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohmanbool CodeGenPrepare::MoveExtToFormExtLoad(Instruction *I) { 864b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman // Look for a load being extended. 865b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman LoadInst *LI = dyn_cast<LoadInst>(I->getOperand(0)); 866b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman if (!LI) return false; 867b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman 868b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman // If they're already in the same block, there's nothing to do. 869b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman if (LI->getParent() == I->getParent()) 870b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman return false; 871b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman 872b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman // If the load has other users and the truncate is not free, this probably 873b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman // isn't worthwhile. 874b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman if (!LI->hasOneUse() && 875ec57a1acec7803fff2faa54c6ea8fec2be01aeb9Bob Wilson TLI && (TLI->isTypeLegal(TLI->getValueType(LI->getType())) || 876ec57a1acec7803fff2faa54c6ea8fec2be01aeb9Bob Wilson !TLI->isTypeLegal(TLI->getValueType(I->getType()))) && 87771dc4d96ed39fadcdccf8c578d49a1afdae0c6baBob Wilson !TLI->isTruncateFree(I->getType(), LI->getType())) 878b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman return false; 879b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman 880b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman // Check whether the target supports casts folded into loads. 881b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman unsigned LType; 882b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman if (isa<ZExtInst>(I)) 883b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman LType = ISD::ZEXTLOAD; 884b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman else { 885b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman assert(isa<SExtInst>(I) && "Unexpected ext type!"); 886b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman LType = ISD::SEXTLOAD; 887b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman } 888b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman if (TLI && !TLI->isLoadExtLegal(LType, TLI->getValueType(LI->getType()))) 889b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman return false; 890b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman 891b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman // Move the extend into the same block as the load, so that SelectionDAG 892b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman // can fold it. 893b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman I->removeFromParent(); 894b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman I->insertAfter(LI); 89531ff1333e0651192212cee6e090df2ff57d19b53Cameron Zwarich ++NumExtsMoved; 896b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman return true; 897b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman} 898b00f236b03ea57520f94823780896ebdbc5d8bdcDan Gohman 899bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Chengbool CodeGenPrepare::OptimizeExtUses(Instruction *I) { 900bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng BasicBlock *DefBB = I->getParent(); 901bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng 9029120f5c35b756e0b9d7747616e97df8f30edfcc8Bob Wilson // If the result of a {s|z}ext and its source are both live out, rewrite all 903bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng // other uses of the source with result of extension. 904bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng Value *Src = I->getOperand(0); 905bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng if (Src->hasOneUse()) 906bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng return false; 907bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng 908696e5c047bd06bf6b7b5471b3f4dec319b43628bEvan Cheng // Only do this xform if truncating is free. 90953bdbd756581a9a1d6d381059f103c5f3c687bb6Gabor Greif if (TLI && !TLI->isTruncateFree(I->getType(), Src->getType())) 910f9785f92b630e69262c395b2fc0893451169d68bEvan Cheng return false; 911f9785f92b630e69262c395b2fc0893451169d68bEvan Cheng 912772de516b6851e679d3da9e5171712b9c3122019Evan Cheng // Only safe to perform the optimization if the source is also defined in 913765dff258545f019502023045b471443ff9ef6c4Evan Cheng // this block. 914765dff258545f019502023045b471443ff9ef6c4Evan Cheng if (!isa<Instruction>(Src) || DefBB != cast<Instruction>(Src)->getParent()) 915772de516b6851e679d3da9e5171712b9c3122019Evan Cheng return false; 916772de516b6851e679d3da9e5171712b9c3122019Evan Cheng 917bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng bool DefIsLiveOut = false; 918692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); 919bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng UI != E; ++UI) { 920bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng Instruction *User = cast<Instruction>(*UI); 921bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng 922bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng // Figure out which BB this ext is used in. 923bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng BasicBlock *UserBB = User->getParent(); 924bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng if (UserBB == DefBB) continue; 925bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng DefIsLiveOut = true; 926bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng break; 927bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng } 928bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng if (!DefIsLiveOut) 929bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng return false; 930bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng 931765dff258545f019502023045b471443ff9ef6c4Evan Cheng // Make sure non of the uses are PHI nodes. 932692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher for (Value::use_iterator UI = Src->use_begin(), E = Src->use_end(); 933765dff258545f019502023045b471443ff9ef6c4Evan Cheng UI != E; ++UI) { 934765dff258545f019502023045b471443ff9ef6c4Evan Cheng Instruction *User = cast<Instruction>(*UI); 935f9785f92b630e69262c395b2fc0893451169d68bEvan Cheng BasicBlock *UserBB = User->getParent(); 936f9785f92b630e69262c395b2fc0893451169d68bEvan Cheng if (UserBB == DefBB) continue; 937f9785f92b630e69262c395b2fc0893451169d68bEvan Cheng // Be conservative. We don't want this xform to end up introducing 938f9785f92b630e69262c395b2fc0893451169d68bEvan Cheng // reloads just before load / store instructions. 939f9785f92b630e69262c395b2fc0893451169d68bEvan Cheng if (isa<PHINode>(User) || isa<LoadInst>(User) || isa<StoreInst>(User)) 940765dff258545f019502023045b471443ff9ef6c4Evan Cheng return false; 941765dff258545f019502023045b471443ff9ef6c4Evan Cheng } 942765dff258545f019502023045b471443ff9ef6c4Evan Cheng 943bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng // InsertedTruncs - Only insert one trunc in each block once. 944bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng DenseMap<BasicBlock*, Instruction*> InsertedTruncs; 945bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng 946bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng bool MadeChange = false; 947692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher for (Value::use_iterator UI = Src->use_begin(), E = Src->use_end(); 948bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng UI != E; ++UI) { 949bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng Use &TheUse = UI.getUse(); 950bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng Instruction *User = cast<Instruction>(*UI); 951bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng 952bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng // Figure out which BB this ext is used in. 953bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng BasicBlock *UserBB = User->getParent(); 954bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng if (UserBB == DefBB) continue; 955bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng 956bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng // Both src and def are live in this block. Rewrite the use. 957bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng Instruction *&InsertedTrunc = InsertedTruncs[UserBB]; 958bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng 959bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng if (!InsertedTrunc) { 96002dea8b39f3acad5de1df36273444d149145e7fcDan Gohman BasicBlock::iterator InsertPt = UserBB->getFirstNonPHI(); 961692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 962bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng InsertedTrunc = new TruncInst(I, Src->getType(), "", InsertPt); 963bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng } 964bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng 965bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng // Replace a use of the {s|z}ext source with a use of the result. 966bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng TheUse = InsertedTrunc; 96731ff1333e0651192212cee6e090df2ff57d19b53Cameron Zwarich ++NumExtUses; 968bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng MadeChange = true; 969bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng } 970bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng 971bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng return MadeChange; 972bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng} 973bdcb726fcad1e3fddc70847a2b91d4d4f9396938Evan Cheng 974c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarichbool CodeGenPrepare::OptimizeInst(Instruction *I) { 975c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich bool MadeChange = false; 976c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich 977c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich if (PHINode *P = dyn_cast<PHINode>(I)) { 978c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich // It is possible for very late stage optimizations (such as SimplifyCFG) 979c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich // to introduce PHI nodes too late to be cleaned up. If we detect such a 980c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich // trivial PHI, go ahead and zap it here. 981c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich if (Value *V = SimplifyInstruction(P)) { 982c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich P->replaceAllUsesWith(V); 983c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich P->eraseFromParent(); 984c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich ++NumPHIsElim; 985c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich } 986c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich } else if (CastInst *CI = dyn_cast<CastInst>(I)) { 987c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich // If the source of the cast is a constant, then this should have 988c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich // already been constant folded. The only reason NOT to constant fold 989c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich // it is if something (e.g. LSR) was careful to place the constant 990c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich // evaluation in a block other than then one that uses it (e.g. to hoist 991c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich // the address of globals out of a loop). If this is the case, we don't 992c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich // want to forward-subst the cast. 993c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich if (isa<Constant>(CI->getOperand(0))) 994c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich return false; 995c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich 996c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich bool Change = false; 997c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich if (TLI) { 998c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich Change = OptimizeNoopCopyExpression(CI, *TLI); 999c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich MadeChange |= Change; 1000c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich } 1001c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich 1002c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich if (!Change && (isa<ZExtInst>(I) || isa<SExtInst>(I))) { 1003c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich MadeChange |= MoveExtToFormExtLoad(I); 1004c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich MadeChange |= OptimizeExtUses(I); 1005c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich } 1006c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich } else if (CmpInst *CI = dyn_cast<CmpInst>(I)) { 1007c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich MadeChange |= OptimizeCmpExpression(CI); 1008c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich } else if (LoadInst *LI = dyn_cast<LoadInst>(I)) { 1009c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich if (TLI) 1010c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich MadeChange |= OptimizeMemoryInst(I, I->getOperand(0), LI->getType(), 1011c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich SunkAddrs); 1012c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) { 1013c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich if (TLI) 1014c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich MadeChange |= OptimizeMemoryInst(I, SI->getOperand(1), 1015c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich SI->getOperand(0)->getType(), 1016c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich SunkAddrs); 1017865ae1a9e77920e07c4a6a992736109c2cd4fe02Cameron Zwarich } else if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(I)) { 1018865ae1a9e77920e07c4a6a992736109c2cd4fe02Cameron Zwarich if (GEPI->hasAllZeroIndices()) { 1019865ae1a9e77920e07c4a6a992736109c2cd4fe02Cameron Zwarich /// The GEP operand must be a pointer, so must its result -> BitCast 1020865ae1a9e77920e07c4a6a992736109c2cd4fe02Cameron Zwarich Instruction *NC = new BitCastInst(GEPI->getOperand(0), GEPI->getType(), 1021865ae1a9e77920e07c4a6a992736109c2cd4fe02Cameron Zwarich GEPI->getName(), GEPI); 1022865ae1a9e77920e07c4a6a992736109c2cd4fe02Cameron Zwarich GEPI->replaceAllUsesWith(NC); 1023865ae1a9e77920e07c4a6a992736109c2cd4fe02Cameron Zwarich GEPI->eraseFromParent(); 1024865ae1a9e77920e07c4a6a992736109c2cd4fe02Cameron Zwarich ++NumGEPsElim; 1025865ae1a9e77920e07c4a6a992736109c2cd4fe02Cameron Zwarich MadeChange = true; 1026865ae1a9e77920e07c4a6a992736109c2cd4fe02Cameron Zwarich OptimizeInst(NC); 1027865ae1a9e77920e07c4a6a992736109c2cd4fe02Cameron Zwarich } 10286cf34abe1c99e79565c75cd3e62755239463e574Cameron Zwarich } else if (CallInst *CI = dyn_cast<CallInst>(I)) { 10296cf34abe1c99e79565c75cd3e62755239463e574Cameron Zwarich if (TLI && isa<InlineAsm>(CI->getCalledValue())) { 10306cf34abe1c99e79565c75cd3e62755239463e574Cameron Zwarich // Sink address computing for memory operands into the block. 10316cf34abe1c99e79565c75cd3e62755239463e574Cameron Zwarich MadeChange |= OptimizeInlineAsmInst(I, &(*CI), SunkAddrs); 10326cf34abe1c99e79565c75cd3e62755239463e574Cameron Zwarich } else { 10336cf34abe1c99e79565c75cd3e62755239463e574Cameron Zwarich MadeChange |= OptimizeCallInst(CI); 10346cf34abe1c99e79565c75cd3e62755239463e574Cameron Zwarich } 1035c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich } 1036c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich 1037c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich return MadeChange; 1038c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich} 1039c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich 1040dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner// In this pass we look for GEP and cast instructions that are used 1041dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner// across basic blocks and rewrite them to improve basic-block-at-a-time 1042dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner// selection. 1043dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattnerbool CodeGenPrepare::OptimizeBlock(BasicBlock &BB) { 1044dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner bool MadeChange = false; 1045692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 1046ab63152871f4144050d0a58d592a95e089fe40d4Evan Cheng // Split all critical edges where the dest block has a PHI. 1047e1bcb440dc0ca3c41fda1c0c581abfc4f38ca170Evan Cheng if (CriticalEdgeSplit) { 1048e1bcb440dc0ca3c41fda1c0c581abfc4f38ca170Evan Cheng TerminatorInst *BBTI = BB.getTerminator(); 1049e1bcb440dc0ca3c41fda1c0c581abfc4f38ca170Evan Cheng if (BBTI->getNumSuccessors() > 1 && !isa<IndirectBrInst>(BBTI)) { 1050e1bcb440dc0ca3c41fda1c0c581abfc4f38ca170Evan Cheng for (unsigned i = 0, e = BBTI->getNumSuccessors(); i != e; ++i) { 1051e1bcb440dc0ca3c41fda1c0c581abfc4f38ca170Evan Cheng BasicBlock *SuccBB = BBTI->getSuccessor(i); 1052e1bcb440dc0ca3c41fda1c0c581abfc4f38ca170Evan Cheng if (isa<PHINode>(SuccBB->begin()) && isCriticalEdge(BBTI, i, true)) 1053e1bcb440dc0ca3c41fda1c0c581abfc4f38ca170Evan Cheng SplitEdgeNicely(BBTI, i, BackEdges, this); 1054e1bcb440dc0ca3c41fda1c0c581abfc4f38ca170Evan Cheng } 1055ab63152871f4144050d0a58d592a95e089fe40d4Evan Cheng } 1056dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner } 1057692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 10588c3527e7a475dd3369a485a4f610d56f7005b7b5Cameron Zwarich SunkAddrs.clear(); 1059692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 1060dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner for (BasicBlock::iterator BBI = BB.begin(), E = BB.end(); BBI != E; ) { 1061dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner Instruction *I = BBI++; 1062692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 1063865ae1a9e77920e07c4a6a992736109c2cd4fe02Cameron Zwarich if (CallInst *CI = dyn_cast<CallInst>(I)) { 1064dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // If we found an inline asm expession, and if the target knows how to 1065dd77df3cbc2301c14f56c9d2cfd412a032c27241Chris Lattner // lower it to normal LLVM code, do so now. 10668850b36d0fdd2ddde3cc409a8496ace544e42185Chris Lattner if (TLI && isa<InlineAsm>(CI->getCalledValue())) { 10678850b36d0fdd2ddde3cc409a8496ace544e42185Chris Lattner if (TLI->ExpandInlineAsm(CI)) { 10688850b36d0fdd2ddde3cc409a8496ace544e42185Chris Lattner BBI = BB.begin(); 10698850b36d0fdd2ddde3cc409a8496ace544e42185Chris Lattner // Avoid processing instructions out of order, which could cause 10708850b36d0fdd2ddde3cc409a8496ace544e42185Chris Lattner // reuse before a value is defined. 10718850b36d0fdd2ddde3cc409a8496ace544e42185Chris Lattner SunkAddrs.clear(); 10728850b36d0fdd2ddde3cc409a8496ace544e42185Chris Lattner } else 10738850b36d0fdd2ddde3cc409a8496ace544e42185Chris Lattner // Sink address computing for memory operands into the block. 10748850b36d0fdd2ddde3cc409a8496ace544e42185Chris Lattner MadeChange |= OptimizeInlineAsmInst(I, &(*CI), SunkAddrs); 1075040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher } else { 1076040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher // Other CallInst optimizations that don't need to muck with the 1077040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher // enclosing iterator here. 1078040056fd11693ffc41ce9b777281c71705d0dc1fEric Christopher MadeChange |= OptimizeCallInst(CI); 10798850b36d0fdd2ddde3cc409a8496ace544e42185Chris Lattner } 1080c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich } else { 1081c061101e03ef6d2ca550f8fe71594a5e1c02e348Cameron Zwarich MadeChange |= OptimizeInst(I); 1082dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner } 1083dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner } 1084692bf6b85e0eaed549cd47d67289ab7b28e32651Eric Christopher 1085dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner return MadeChange; 1086dbe0deca339585dfbaed5951ef0ca2c6a0df173cChris Lattner} 1087