InlineCost.cpp revision 13086a658ae06046ded902229f9918b8bad505bd
1e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman//===- InlineCost.cpp - Cost analysis for inliner -------------------------===// 2e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman// 3e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman// The LLVM Compiler Infrastructure 4e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman// 5e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman// This file is distributed under the University of Illinois Open Source 6e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman// License. See LICENSE.TXT for details. 7e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman// 8e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman//===----------------------------------------------------------------------===// 9e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman// 10e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman// This file implements inline cost analysis. 11e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman// 12e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman//===----------------------------------------------------------------------===// 13e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman 14f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth#define DEBUG_TYPE "inline-cost" 15e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman#include "llvm/Analysis/InlineCost.h" 16d04a8d4b33ff316ca4cf961e06c9e312eff8e64fChandler Carruth#include "llvm/ADT/STLExtras.h" 17d04a8d4b33ff316ca4cf961e06c9e312eff8e64fChandler Carruth#include "llvm/ADT/SetVector.h" 18d04a8d4b33ff316ca4cf961e06c9e312eff8e64fChandler Carruth#include "llvm/ADT/SmallPtrSet.h" 19d04a8d4b33ff316ca4cf961e06c9e312eff8e64fChandler Carruth#include "llvm/ADT/SmallVector.h" 20d04a8d4b33ff316ca4cf961e06c9e312eff8e64fChandler Carruth#include "llvm/ADT/Statistic.h" 21f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth#include "llvm/Analysis/ConstantFolding.h" 22f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth#include "llvm/Analysis/InstructionSimplify.h" 238d6c0f4deeb0f2ff671df7ae92b75ee1e39acd37Chandler Carruth#include "llvm/Analysis/TargetTransformInfo.h" 240b8c9a80f20772c3793201ab5b251d3520b9cea3Chandler Carruth#include "llvm/IR/CallingConv.h" 250b8c9a80f20772c3793201ab5b251d3520b9cea3Chandler Carruth#include "llvm/IR/DataLayout.h" 260b8c9a80f20772c3793201ab5b251d3520b9cea3Chandler Carruth#include "llvm/IR/GlobalAlias.h" 270b8c9a80f20772c3793201ab5b251d3520b9cea3Chandler Carruth#include "llvm/IR/IntrinsicInst.h" 280b8c9a80f20772c3793201ab5b251d3520b9cea3Chandler Carruth#include "llvm/IR/Operator.h" 2984bcf93e0fd225de2217d1b712c01586a633a6d8Chandler Carruth#include "llvm/InstVisitor.h" 30d04a8d4b33ff316ca4cf961e06c9e312eff8e64fChandler Carruth#include "llvm/Support/CallSite.h" 31d04a8d4b33ff316ca4cf961e06c9e312eff8e64fChandler Carruth#include "llvm/Support/Debug.h" 32d04a8d4b33ff316ca4cf961e06c9e312eff8e64fChandler Carruth#include "llvm/Support/GetElementPtrTypeIterator.h" 33d04a8d4b33ff316ca4cf961e06c9e312eff8e64fChandler Carruth#include "llvm/Support/raw_ostream.h" 344e8af6db184118638c21f713ad98e3292c6891c9Eric Christopher 35e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohmanusing namespace llvm; 36e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman 37d6fc26217e194372cabe4ef9e2514beac511a943Chandler CarruthSTATISTIC(NumCallsAnalyzed, "Number of call sites analyzed"); 38d6fc26217e194372cabe4ef9e2514beac511a943Chandler Carruth 39f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthnamespace { 40f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 41f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthclass CallAnalyzer : public InstVisitor<CallAnalyzer, bool> { 42f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth typedef InstVisitor<CallAnalyzer, bool> Base; 43f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth friend class InstVisitor<CallAnalyzer, bool>; 44f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 453574eca1b02600bac4e625297f4ecf745f4c4f32Micah Villmow // DataLayout if available, or null. 463574eca1b02600bac4e625297f4ecf745f4c4f32Micah Villmow const DataLayout *const TD; 47f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 488d6c0f4deeb0f2ff671df7ae92b75ee1e39acd37Chandler Carruth /// The TargetTransformInfo available for this compilation. 498d6c0f4deeb0f2ff671df7ae92b75ee1e39acd37Chandler Carruth const TargetTransformInfo &TTI; 508d6c0f4deeb0f2ff671df7ae92b75ee1e39acd37Chandler Carruth 51f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // The called function. 52f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Function &F; 53f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 54f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth int Threshold; 55f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth int Cost; 56f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 5792df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem bool IsCallerRecursive; 5892df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem bool IsRecursiveCall; 59f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool ExposesReturnsTwice; 60f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool HasDynamicAlloca; 6167ae13575900e8efd056672987249fd0adbf5e73James Molloy bool ContainsNoDuplicateCall; 6267ae13575900e8efd056672987249fd0adbf5e73James Molloy 6392df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem /// Number of bytes allocated statically by the callee. 6492df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem uint64_t AllocatedSize; 65f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth unsigned NumInstructions, NumVectorInstructions; 66f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth int FiftyPercentVectorBonus, TenPercentVectorBonus; 67f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth int VectorBonus; 68f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 69f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // While we walk the potentially-inlined instructions, we build up and 70f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // maintain a mapping of simplified values specific to this callsite. The 71f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // idea is to propagate any special information we have about arguments to 72f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // this call through the inlinable section of the function, and account for 73f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // likely simplifications post-inlining. The most important aspect we track 74f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // is CFG altering simplifications -- when we prove a basic block dead, that 75f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // can cause dramatic shifts in the cost of inlining a function. 76f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DenseMap<Value *, Constant *> SimplifiedValues; 77f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 78f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Keep track of the values which map back (through function arguments) to 79f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // allocas on the caller stack which could be simplified through SROA. 80f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DenseMap<Value *, Value *> SROAArgValues; 81f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 82f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // The mapping of caller Alloca values to their accumulated cost savings. If 83f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // we have to disable SROA for one of the allocas, this tells us how much 84f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // cost must be added. 85f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DenseMap<Value *, int> SROAArgCosts; 86f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 87f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Keep track of values which map to a pointer base and constant offset. 88f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DenseMap<Value *, std::pair<Value *, APInt> > ConstantOffsetPtrs; 89f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 90f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Custom simplification helper routines. 91f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool isAllocaDerivedArg(Value *V); 92f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool lookupSROAArgAndCost(Value *V, Value *&Arg, 93f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DenseMap<Value *, int>::iterator &CostIt); 94f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth void disableSROA(DenseMap<Value *, int>::iterator CostIt); 95f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth void disableSROA(Value *V); 96f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth void accumulateSROACost(DenseMap<Value *, int>::iterator CostIt, 97f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth int InstructionCost); 98f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool handleSROACandidate(bool IsSROAValid, 99f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DenseMap<Value *, int>::iterator CostIt, 100f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth int InstructionCost); 101f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool isGEPOffsetConstant(GetElementPtrInst &GEP); 102f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool accumulateGEPOffset(GEPOperator &GEP, APInt &Offset); 103ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth bool simplifyCallSite(Function *F, CallSite CS); 104f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth ConstantInt *stripAndComputeInBoundsConstantOffsets(Value *&V); 105f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 106f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Custom analysis routines. 107f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool analyzeBlock(BasicBlock *BB); 108f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 109f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Disable several entry points to the visitor so we don't accidentally use 110f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // them by declaring but not defining them here. 111f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth void visit(Module *); void visit(Module &); 112f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth void visit(Function *); void visit(Function &); 113f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth void visit(BasicBlock *); void visit(BasicBlock &); 114f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 115f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Provide base case for our instruction visit. 116f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool visitInstruction(Instruction &I); 117f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 118f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Our visit overrides. 119f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool visitAlloca(AllocaInst &I); 120f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool visitPHI(PHINode &I); 121f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool visitGetElementPtr(GetElementPtrInst &I); 122f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool visitBitCast(BitCastInst &I); 123f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool visitPtrToInt(PtrToIntInst &I); 124f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool visitIntToPtr(IntToPtrInst &I); 125f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool visitCastInst(CastInst &I); 126f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool visitUnaryInstruction(UnaryInstruction &I); 127f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool visitICmp(ICmpInst &I); 128f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool visitSub(BinaryOperator &I); 129f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool visitBinaryOperator(BinaryOperator &I); 130f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool visitLoad(LoadInst &I); 131f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool visitStore(StoreInst &I); 132ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth bool visitExtractValue(ExtractValueInst &I); 133ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth bool visitInsertValue(InsertValueInst &I); 134f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool visitCallSite(CallSite CS); 135f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 136f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthpublic: 1378d6c0f4deeb0f2ff671df7ae92b75ee1e39acd37Chandler Carruth CallAnalyzer(const DataLayout *TD, const TargetTransformInfo &TTI, 1388d6c0f4deeb0f2ff671df7ae92b75ee1e39acd37Chandler Carruth Function &Callee, int Threshold) 1398d6c0f4deeb0f2ff671df7ae92b75ee1e39acd37Chandler Carruth : TD(TD), TTI(TTI), F(Callee), Threshold(Threshold), Cost(0), 1408d6c0f4deeb0f2ff671df7ae92b75ee1e39acd37Chandler Carruth IsCallerRecursive(false), IsRecursiveCall(false), 1418d6c0f4deeb0f2ff671df7ae92b75ee1e39acd37Chandler Carruth ExposesReturnsTwice(false), HasDynamicAlloca(false), 1428d6c0f4deeb0f2ff671df7ae92b75ee1e39acd37Chandler Carruth ContainsNoDuplicateCall(false), AllocatedSize(0), NumInstructions(0), 1438d6c0f4deeb0f2ff671df7ae92b75ee1e39acd37Chandler Carruth NumVectorInstructions(0), FiftyPercentVectorBonus(0), 1448d6c0f4deeb0f2ff671df7ae92b75ee1e39acd37Chandler Carruth TenPercentVectorBonus(0), VectorBonus(0), NumConstantArgs(0), 1458d6c0f4deeb0f2ff671df7ae92b75ee1e39acd37Chandler Carruth NumConstantOffsetPtrArgs(0), NumAllocaArgs(0), NumConstantPtrCmps(0), 1468d6c0f4deeb0f2ff671df7ae92b75ee1e39acd37Chandler Carruth NumConstantPtrDiffs(0), NumInstructionsSimplified(0), 1478d6c0f4deeb0f2ff671df7ae92b75ee1e39acd37Chandler Carruth SROACostSavings(0), SROACostSavingsLost(0) {} 1483d1d895c866b76ac4d862301f36e2b95d803f0abChandler Carruth 149f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool analyzeCall(CallSite CS); 150082bf2a977b6bb91d61ac5155e1906ecc6ba47bfOwen Anderson 151f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth int getThreshold() { return Threshold; } 152f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth int getCost() { return Cost; } 153082bf2a977b6bb91d61ac5155e1906ecc6ba47bfOwen Anderson 154f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Keep a bunch of stats about the cost savings found so we can print them 155f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // out when debugging. 156f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth unsigned NumConstantArgs; 157f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth unsigned NumConstantOffsetPtrArgs; 158f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth unsigned NumAllocaArgs; 159f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth unsigned NumConstantPtrCmps; 160f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth unsigned NumConstantPtrDiffs; 161f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth unsigned NumInstructionsSimplified; 162f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth unsigned SROACostSavings; 163f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth unsigned SROACostSavingsLost; 164082bf2a977b6bb91d61ac5155e1906ecc6ba47bfOwen Anderson 165f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth void dump(); 166f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth}; 167082bf2a977b6bb91d61ac5155e1906ecc6ba47bfOwen Anderson 168f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth} // namespace 169e8187e02949571e8a610644762b843ef2891f011Chandler Carruth 170f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// \brief Test whether the given value is an Alloca-derived function argument. 171f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::isAllocaDerivedArg(Value *V) { 172f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return SROAArgValues.count(V); 173f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth} 174e8187e02949571e8a610644762b843ef2891f011Chandler Carruth 175f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// \brief Lookup the SROA-candidate argument and cost iterator which V maps to. 176f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// Returns false if V does not map to a SROA-candidate. 177f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::lookupSROAArgAndCost( 178f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *V, Value *&Arg, DenseMap<Value *, int>::iterator &CostIt) { 179f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (SROAArgValues.empty() || SROAArgCosts.empty()) 180f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return false; 181e8187e02949571e8a610644762b843ef2891f011Chandler Carruth 182f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DenseMap<Value *, Value *>::iterator ArgIt = SROAArgValues.find(V); 183f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (ArgIt == SROAArgValues.end()) 184f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return false; 185e8187e02949571e8a610644762b843ef2891f011Chandler Carruth 186f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Arg = ArgIt->second; 187f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth CostIt = SROAArgCosts.find(Arg); 188f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return CostIt != SROAArgCosts.end(); 189e8187e02949571e8a610644762b843ef2891f011Chandler Carruth} 190e8187e02949571e8a610644762b843ef2891f011Chandler Carruth 191f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// \brief Disable SROA for the candidate marked by this cost iterator. 192e8187e02949571e8a610644762b843ef2891f011Chandler Carruth/// 193d9b0b025612992a0b724eeca8bdf10b1d7a5c355Benjamin Kramer/// This marks the candidate as no longer viable for SROA, and adds the cost 194f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// savings associated with it back into the inline cost measurement. 195f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthvoid CallAnalyzer::disableSROA(DenseMap<Value *, int>::iterator CostIt) { 196f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // If we're no longer able to perform SROA we need to undo its cost savings 197f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // and prevent subsequent analysis. 198f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Cost += CostIt->second; 199f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SROACostSavings -= CostIt->second; 200f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SROACostSavingsLost += CostIt->second; 201f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SROAArgCosts.erase(CostIt); 202f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth} 203f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 204f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// \brief If 'V' maps to a SROA candidate, disable SROA for it. 205f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthvoid CallAnalyzer::disableSROA(Value *V) { 206f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *SROAArg; 207f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DenseMap<Value *, int>::iterator CostIt; 208f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (lookupSROAArgAndCost(V, SROAArg, CostIt)) 209f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth disableSROA(CostIt); 210f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth} 211f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 212f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// \brief Accumulate the given cost for a particular SROA candidate. 213f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthvoid CallAnalyzer::accumulateSROACost(DenseMap<Value *, int>::iterator CostIt, 214f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth int InstructionCost) { 215f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth CostIt->second += InstructionCost; 216f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SROACostSavings += InstructionCost; 217f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth} 218f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 219f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// \brief Helper for the common pattern of handling a SROA candidate. 220f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// Either accumulates the cost savings if the SROA remains valid, or disables 221f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// SROA for the candidate. 222f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::handleSROACandidate(bool IsSROAValid, 223f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DenseMap<Value *, int>::iterator CostIt, 224f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth int InstructionCost) { 225f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (IsSROAValid) { 226f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth accumulateSROACost(CostIt, InstructionCost); 227e8187e02949571e8a610644762b843ef2891f011Chandler Carruth return true; 228e8187e02949571e8a610644762b843ef2891f011Chandler Carruth } 229e8187e02949571e8a610644762b843ef2891f011Chandler Carruth 230f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth disableSROA(CostIt); 231f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return false; 232f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth} 233f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 234f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// \brief Check whether a GEP's indices are all constant. 235f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// 236f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// Respects any simplified values known during the analysis of this callsite. 237f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::isGEPOffsetConstant(GetElementPtrInst &GEP) { 238f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth for (User::op_iterator I = GEP.idx_begin(), E = GEP.idx_end(); I != E; ++I) 239f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (!isa<Constant>(*I) && !SimplifiedValues.lookup(*I)) 240e8187e02949571e8a610644762b843ef2891f011Chandler Carruth return false; 241e8187e02949571e8a610644762b843ef2891f011Chandler Carruth 242f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return true; 243f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth} 244f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 245f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// \brief Accumulate a constant GEP offset into an APInt if possible. 246f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// 247f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// Returns false if unable to compute the offset for any reason. Respects any 248f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// simplified values known during the analysis of this callsite. 249f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::accumulateGEPOffset(GEPOperator &GEP, APInt &Offset) { 250f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (!TD) 251f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return false; 252f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 253426c2bf5cdd2173e4a33aea8cb92cf684a724f4bChandler Carruth unsigned IntPtrWidth = TD->getPointerSizeInBits(); 254f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth assert(IntPtrWidth == Offset.getBitWidth()); 255f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 256f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth for (gep_type_iterator GTI = gep_type_begin(GEP), GTE = gep_type_end(GEP); 257f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth GTI != GTE; ++GTI) { 258f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth ConstantInt *OpC = dyn_cast<ConstantInt>(GTI.getOperand()); 259f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (!OpC) 260f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (Constant *SimpleOp = SimplifiedValues.lookup(GTI.getOperand())) 261f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth OpC = dyn_cast<ConstantInt>(SimpleOp); 262f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (!OpC) 263e8187e02949571e8a610644762b843ef2891f011Chandler Carruth return false; 264f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (OpC->isZero()) continue; 265e8187e02949571e8a610644762b843ef2891f011Chandler Carruth 266f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Handle a struct index, which adds its field offset to the pointer. 267f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (StructType *STy = dyn_cast<StructType>(*GTI)) { 268f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth unsigned ElementIdx = OpC->getZExtValue(); 269f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth const StructLayout *SL = TD->getStructLayout(STy); 270f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Offset += APInt(IntPtrWidth, SL->getElementOffset(ElementIdx)); 271f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth continue; 272f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 273f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 274f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth APInt TypeSize(IntPtrWidth, TD->getTypeAllocSize(GTI.getIndexedType())); 275f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Offset += OpC->getValue().sextOrTrunc(IntPtrWidth) * TypeSize; 276e8187e02949571e8a610644762b843ef2891f011Chandler Carruth } 277f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return true; 278f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth} 279f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 280f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::visitAlloca(AllocaInst &I) { 281f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // FIXME: Check whether inlining will turn a dynamic alloca into a static 282f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // alloca, and handle that case. 283e8187e02949571e8a610644762b843ef2891f011Chandler Carruth 28492df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem // Accumulate the allocated size. 28592df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem if (I.isStaticAlloca()) { 28692df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem Type *Ty = I.getAllocatedType(); 28792df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem AllocatedSize += (TD ? TD->getTypeAllocSize(Ty) : 28892df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem Ty->getPrimitiveSizeInBits()); 28992df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem } 29092df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem 29128f872f8a1945635f30763805c1418a90c6b345eBob Wilson // We will happily inline static alloca instructions. 29228f872f8a1945635f30763805c1418a90c6b345eBob Wilson if (I.isStaticAlloca()) 293f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return Base::visitAlloca(I); 294f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 295f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // FIXME: This is overly conservative. Dynamic allocas are inefficient for 296f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // a variety of reasons, and so we would like to not inline them into 297f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // functions which don't currently have a dynamic alloca. This simply 298f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // disables inlining altogether in the presence of a dynamic alloca. 299f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth HasDynamicAlloca = true; 300f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return false; 301f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth} 302f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 303f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::visitPHI(PHINode &I) { 304f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // FIXME: We should potentially be tracking values through phi nodes, 305f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // especially when they collapse to a single value due to deleted CFG edges 306f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // during inlining. 307f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 308f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // FIXME: We need to propagate SROA *disabling* through phi nodes, even 309f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // though we don't want to propagate it's bonuses. The idea is to disable 310f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // SROA if it *might* be used in an inappropriate manner. 311f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 312f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Phi nodes are always zero-cost. 313f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return true; 314f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth} 315f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 316f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::visitGetElementPtr(GetElementPtrInst &I) { 317f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *SROAArg; 318f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DenseMap<Value *, int>::iterator CostIt; 319f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool SROACandidate = lookupSROAArgAndCost(I.getPointerOperand(), 320f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SROAArg, CostIt); 321f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 322f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Try to fold GEPs of constant-offset call site argument pointers. This 323f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // requires target data and inbounds GEPs. 324f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (TD && I.isInBounds()) { 325f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Check if we have a base + offset for the pointer. 326f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *Ptr = I.getPointerOperand(); 327f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth std::pair<Value *, APInt> BaseAndOffset = ConstantOffsetPtrs.lookup(Ptr); 328f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (BaseAndOffset.first) { 329f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Check if the offset of this GEP is constant, and if so accumulate it 330f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // into Offset. 331f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (!accumulateGEPOffset(cast<GEPOperator>(I), BaseAndOffset.second)) { 332f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Non-constant GEPs aren't folded, and disable SROA. 333f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (SROACandidate) 334f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth disableSROA(CostIt); 335e8187e02949571e8a610644762b843ef2891f011Chandler Carruth return false; 336f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 337f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 338f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Add the result as a new mapping to Base + Offset. 339f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth ConstantOffsetPtrs[&I] = BaseAndOffset; 340f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 341f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Also handle SROA candidates here, we already know that the GEP is 342f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // all-constant indexed. 343f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (SROACandidate) 344f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SROAArgValues[&I] = SROAArg; 345f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 346f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return true; 347e8187e02949571e8a610644762b843ef2891f011Chandler Carruth } 348f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 349f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 350f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (isGEPOffsetConstant(I)) { 351f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (SROACandidate) 352f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SROAArgValues[&I] = SROAArg; 353f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 354f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Constant GEPs are modeled as free. 355e8187e02949571e8a610644762b843ef2891f011Chandler Carruth return true; 356e8187e02949571e8a610644762b843ef2891f011Chandler Carruth } 357e8187e02949571e8a610644762b843ef2891f011Chandler Carruth 358f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Variable GEPs will require math and will disable SROA. 359f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (SROACandidate) 360f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth disableSROA(CostIt); 361f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return false; 362f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth} 363f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 364f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::visitBitCast(BitCastInst &I) { 365f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Propagate constants through bitcasts. 36673527d30cddd9b542a01a33c333bc707504fd05fChandler Carruth Constant *COp = dyn_cast<Constant>(I.getOperand(0)); 36773527d30cddd9b542a01a33c333bc707504fd05fChandler Carruth if (!COp) 36873527d30cddd9b542a01a33c333bc707504fd05fChandler Carruth COp = SimplifiedValues.lookup(I.getOperand(0)); 36973527d30cddd9b542a01a33c333bc707504fd05fChandler Carruth if (COp) 370f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (Constant *C = ConstantExpr::getBitCast(COp, I.getType())) { 371f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SimplifiedValues[&I] = C; 372e8187e02949571e8a610644762b843ef2891f011Chandler Carruth return true; 373e8187e02949571e8a610644762b843ef2891f011Chandler Carruth } 374f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 375f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Track base/offsets through casts 376f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth std::pair<Value *, APInt> BaseAndOffset 377f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth = ConstantOffsetPtrs.lookup(I.getOperand(0)); 378f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Casts don't change the offset, just wrap it up. 379f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (BaseAndOffset.first) 380f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth ConstantOffsetPtrs[&I] = BaseAndOffset; 381f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 382f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Also look for SROA candidates here. 383f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *SROAArg; 384f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DenseMap<Value *, int>::iterator CostIt; 385f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt)) 386f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SROAArgValues[&I] = SROAArg; 387f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 388f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Bitcasts are always zero cost. 389f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return true; 390f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth} 391f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 392f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::visitPtrToInt(PtrToIntInst &I) { 393f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Propagate constants through ptrtoint. 39473527d30cddd9b542a01a33c333bc707504fd05fChandler Carruth Constant *COp = dyn_cast<Constant>(I.getOperand(0)); 39573527d30cddd9b542a01a33c333bc707504fd05fChandler Carruth if (!COp) 39673527d30cddd9b542a01a33c333bc707504fd05fChandler Carruth COp = SimplifiedValues.lookup(I.getOperand(0)); 39773527d30cddd9b542a01a33c333bc707504fd05fChandler Carruth if (COp) 398f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (Constant *C = ConstantExpr::getPtrToInt(COp, I.getType())) { 399f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SimplifiedValues[&I] = C; 400f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return true; 401f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 402f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 403f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Track base/offset pairs when converted to a plain integer provided the 404f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // integer is large enough to represent the pointer. 405f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth unsigned IntegerSize = I.getType()->getScalarSizeInBits(); 406426c2bf5cdd2173e4a33aea8cb92cf684a724f4bChandler Carruth if (TD && IntegerSize >= TD->getPointerSizeInBits()) { 407f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth std::pair<Value *, APInt> BaseAndOffset 408f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth = ConstantOffsetPtrs.lookup(I.getOperand(0)); 409f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (BaseAndOffset.first) 410f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth ConstantOffsetPtrs[&I] = BaseAndOffset; 411e8187e02949571e8a610644762b843ef2891f011Chandler Carruth } 412e8187e02949571e8a610644762b843ef2891f011Chandler Carruth 413f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // This is really weird. Technically, ptrtoint will disable SROA. However, 414f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // unless that ptrtoint is *used* somewhere in the live basic blocks after 415f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // inlining, it will be nuked, and SROA should proceed. All of the uses which 416f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // would block SROA would also block SROA if applied directly to a pointer, 417f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // and so we can just add the integer in here. The only places where SROA is 418f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // preserved either cannot fire on an integer, or won't in-and-of themselves 419f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // disable SROA (ext) w/o some later use that we would see and disable. 420f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *SROAArg; 421f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DenseMap<Value *, int>::iterator CostIt; 422f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt)) 423f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SROAArgValues[&I] = SROAArg; 424f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 425b5da8a4ae1fbd8e4ffab06cfeb5b32a94d0381bbChandler Carruth return TargetTransformInfo::TCC_Free == TTI.getUserCost(&I); 426e8187e02949571e8a610644762b843ef2891f011Chandler Carruth} 427e8187e02949571e8a610644762b843ef2891f011Chandler Carruth 428f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::visitIntToPtr(IntToPtrInst &I) { 429f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Propagate constants through ptrtoint. 43073527d30cddd9b542a01a33c333bc707504fd05fChandler Carruth Constant *COp = dyn_cast<Constant>(I.getOperand(0)); 43173527d30cddd9b542a01a33c333bc707504fd05fChandler Carruth if (!COp) 43273527d30cddd9b542a01a33c333bc707504fd05fChandler Carruth COp = SimplifiedValues.lookup(I.getOperand(0)); 43373527d30cddd9b542a01a33c333bc707504fd05fChandler Carruth if (COp) 434f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (Constant *C = ConstantExpr::getIntToPtr(COp, I.getType())) { 435f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SimplifiedValues[&I] = C; 436f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return true; 437f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 4386977e79526a6342b9408c358bca21c3b0c7e61d5Nick Lewycky 439f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Track base/offset pairs when round-tripped through a pointer without 440f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // modifications provided the integer is not too large. 441f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *Op = I.getOperand(0); 442f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth unsigned IntegerSize = Op->getType()->getScalarSizeInBits(); 443426c2bf5cdd2173e4a33aea8cb92cf684a724f4bChandler Carruth if (TD && IntegerSize <= TD->getPointerSizeInBits()) { 444f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth std::pair<Value *, APInt> BaseAndOffset = ConstantOffsetPtrs.lookup(Op); 445f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (BaseAndOffset.first) 446f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth ConstantOffsetPtrs[&I] = BaseAndOffset; 447f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 448e8187e02949571e8a610644762b843ef2891f011Chandler Carruth 449f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // "Propagate" SROA here in the same manner as we do for ptrtoint above. 450f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *SROAArg; 451f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DenseMap<Value *, int>::iterator CostIt; 452f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (lookupSROAArgAndCost(Op, SROAArg, CostIt)) 453f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SROAArgValues[&I] = SROAArg; 454e8187e02949571e8a610644762b843ef2891f011Chandler Carruth 455b5da8a4ae1fbd8e4ffab06cfeb5b32a94d0381bbChandler Carruth return TargetTransformInfo::TCC_Free == TTI.getUserCost(&I); 456f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth} 457f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 458f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::visitCastInst(CastInst &I) { 459f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Propagate constants through ptrtoint. 46073527d30cddd9b542a01a33c333bc707504fd05fChandler Carruth Constant *COp = dyn_cast<Constant>(I.getOperand(0)); 46173527d30cddd9b542a01a33c333bc707504fd05fChandler Carruth if (!COp) 46273527d30cddd9b542a01a33c333bc707504fd05fChandler Carruth COp = SimplifiedValues.lookup(I.getOperand(0)); 46373527d30cddd9b542a01a33c333bc707504fd05fChandler Carruth if (COp) 464f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (Constant *C = ConstantExpr::getCast(I.getOpcode(), COp, I.getType())) { 465f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SimplifiedValues[&I] = C; 466f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return true; 467082bf2a977b6bb91d61ac5155e1906ecc6ba47bfOwen Anderson } 468082bf2a977b6bb91d61ac5155e1906ecc6ba47bfOwen Anderson 469f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Disable SROA in the face of arbitrary casts we don't whitelist elsewhere. 470f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth disableSROA(I.getOperand(0)); 471f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 472b5da8a4ae1fbd8e4ffab06cfeb5b32a94d0381bbChandler Carruth return TargetTransformInfo::TCC_Free == TTI.getUserCost(&I); 473082bf2a977b6bb91d61ac5155e1906ecc6ba47bfOwen Anderson} 474082bf2a977b6bb91d61ac5155e1906ecc6ba47bfOwen Anderson 475f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::visitUnaryInstruction(UnaryInstruction &I) { 476f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *Operand = I.getOperand(0); 477f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Constant *Ops[1] = { dyn_cast<Constant>(Operand) }; 478f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (Ops[0] || (Ops[0] = SimplifiedValues.lookup(Operand))) 479f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (Constant *C = ConstantFoldInstOperands(I.getOpcode(), I.getType(), 480f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Ops, TD)) { 481f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SimplifiedValues[&I] = C; 482f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return true; 483f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 484274d377ea68195989c3238fe96ce2ca812a12fafChandler Carruth 485f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Disable any SROA on the argument to arbitrary unary operators. 486f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth disableSROA(Operand); 487f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 488f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return false; 489f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth} 490f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 491f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::visitICmp(ICmpInst &I) { 492f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *LHS = I.getOperand(0), *RHS = I.getOperand(1); 493f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // First try to handle simplified comparisons. 494f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (!isa<Constant>(LHS)) 495f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (Constant *SimpleLHS = SimplifiedValues.lookup(LHS)) 496f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth LHS = SimpleLHS; 497f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (!isa<Constant>(RHS)) 498f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (Constant *SimpleRHS = SimplifiedValues.lookup(RHS)) 499f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth RHS = SimpleRHS; 500f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (Constant *CLHS = dyn_cast<Constant>(LHS)) 501f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (Constant *CRHS = dyn_cast<Constant>(RHS)) 502f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (Constant *C = ConstantExpr::getICmp(I.getPredicate(), CLHS, CRHS)) { 503f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SimplifiedValues[&I] = C; 504f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return true; 505274d377ea68195989c3238fe96ce2ca812a12fafChandler Carruth } 506274d377ea68195989c3238fe96ce2ca812a12fafChandler Carruth 507f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Otherwise look for a comparison between constant offset pointers with 508f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // a common base. 509f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *LHSBase, *RHSBase; 510f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth APInt LHSOffset, RHSOffset; 511f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth llvm::tie(LHSBase, LHSOffset) = ConstantOffsetPtrs.lookup(LHS); 512f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (LHSBase) { 513f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth llvm::tie(RHSBase, RHSOffset) = ConstantOffsetPtrs.lookup(RHS); 514f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (RHSBase && LHSBase == RHSBase) { 515f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // We have common bases, fold the icmp to a constant based on the 516f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // offsets. 517f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Constant *CLHS = ConstantInt::get(LHS->getContext(), LHSOffset); 518f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Constant *CRHS = ConstantInt::get(RHS->getContext(), RHSOffset); 519f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (Constant *C = ConstantExpr::getICmp(I.getPredicate(), CLHS, CRHS)) { 520f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SimplifiedValues[&I] = C; 521f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth ++NumConstantPtrCmps; 522f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return true; 523274d377ea68195989c3238fe96ce2ca812a12fafChandler Carruth } 524f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 525f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 526274d377ea68195989c3238fe96ce2ca812a12fafChandler Carruth 527f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // If the comparison is an equality comparison with null, we can simplify it 528f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // for any alloca-derived argument. 529f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (I.isEquality() && isa<ConstantPointerNull>(I.getOperand(1))) 530f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (isAllocaDerivedArg(I.getOperand(0))) { 531f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // We can actually predict the result of comparisons between an 532f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // alloca-derived value and null. Note that this fires regardless of 533f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // SROA firing. 534f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool IsNotEqual = I.getPredicate() == CmpInst::ICMP_NE; 535f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SimplifiedValues[&I] = IsNotEqual ? ConstantInt::getTrue(I.getType()) 536f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth : ConstantInt::getFalse(I.getType()); 537f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return true; 538f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 539274d377ea68195989c3238fe96ce2ca812a12fafChandler Carruth 540f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Finally check for SROA candidates in comparisons. 541f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *SROAArg; 542f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DenseMap<Value *, int>::iterator CostIt; 543f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt)) { 544f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (isa<ConstantPointerNull>(I.getOperand(1))) { 545f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth accumulateSROACost(CostIt, InlineConstants::InstrCost); 546f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return true; 547274d377ea68195989c3238fe96ce2ca812a12fafChandler Carruth } 548274d377ea68195989c3238fe96ce2ca812a12fafChandler Carruth 549f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth disableSROA(CostIt); 550274d377ea68195989c3238fe96ce2ca812a12fafChandler Carruth } 551e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman 552f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return false; 55342c7d23c6d56e0743169d94025264eaf17eb799dKenneth Uildriks} 55474fa7327d690e6ceda6ce77e4e5b8ef75cb12538Kenneth Uildriks 555f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::visitSub(BinaryOperator &I) { 556f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Try to handle a special case: we can fold computing the difference of two 557f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // constant-related pointers. 558f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *LHS = I.getOperand(0), *RHS = I.getOperand(1); 559f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *LHSBase, *RHSBase; 560f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth APInt LHSOffset, RHSOffset; 561f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth llvm::tie(LHSBase, LHSOffset) = ConstantOffsetPtrs.lookup(LHS); 562f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (LHSBase) { 563f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth llvm::tie(RHSBase, RHSOffset) = ConstantOffsetPtrs.lookup(RHS); 564f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (RHSBase && LHSBase == RHSBase) { 565f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // We have common bases, fold the subtract to a constant based on the 566f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // offsets. 567f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Constant *CLHS = ConstantInt::get(LHS->getContext(), LHSOffset); 568f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Constant *CRHS = ConstantInt::get(RHS->getContext(), RHSOffset); 569f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (Constant *C = ConstantExpr::getSub(CLHS, CRHS)) { 570f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SimplifiedValues[&I] = C; 571f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth ++NumConstantPtrDiffs; 572f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return true; 573f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 574f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 575f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 5765c655413cf9466c29e38204ab3f19b33fffd7996Andrew Trick 577f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Otherwise, fall back to the generic logic for simplifying and handling 578f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // instructions. 579f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return Base::visitSub(I); 580f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth} 581f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 582f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::visitBinaryOperator(BinaryOperator &I) { 583f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *LHS = I.getOperand(0), *RHS = I.getOperand(1); 584f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (!isa<Constant>(LHS)) 585f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (Constant *SimpleLHS = SimplifiedValues.lookup(LHS)) 586f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth LHS = SimpleLHS; 587f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (!isa<Constant>(RHS)) 588f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (Constant *SimpleRHS = SimplifiedValues.lookup(RHS)) 589f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth RHS = SimpleRHS; 590f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *SimpleV = SimplifyBinOp(I.getOpcode(), LHS, RHS, TD); 591f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (Constant *C = dyn_cast_or_null<Constant>(SimpleV)) { 592f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SimplifiedValues[&I] = C; 593f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return true; 594f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 5955c655413cf9466c29e38204ab3f19b33fffd7996Andrew Trick 596f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Disable any SROA on arguments to arbitrary, unsimplified binary operators. 597f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth disableSROA(LHS); 598f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth disableSROA(RHS); 5995c655413cf9466c29e38204ab3f19b33fffd7996Andrew Trick 600f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return false; 6014e8af6db184118638c21f713ad98e3292c6891c9Eric Christopher} 6024e8af6db184118638c21f713ad98e3292c6891c9Eric Christopher 603f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::visitLoad(LoadInst &I) { 604f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *SROAArg; 605f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DenseMap<Value *, int>::iterator CostIt; 606f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt)) { 607f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (I.isSimple()) { 608f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth accumulateSROACost(CostIt, InlineConstants::InstrCost); 609f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return true; 6108e2da0ce9d70606e10889d17f481842586132d88Eric Christopher } 6118e2da0ce9d70606e10889d17f481842586132d88Eric Christopher 612f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth disableSROA(CostIt); 613f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 6148e2da0ce9d70606e10889d17f481842586132d88Eric Christopher 615f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return false; 616f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth} 617f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 618f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::visitStore(StoreInst &I) { 619f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *SROAArg; 620f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DenseMap<Value *, int>::iterator CostIt; 621f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt)) { 622f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (I.isSimple()) { 623f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth accumulateSROACost(CostIt, InlineConstants::InstrCost); 624f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return true; 6258e2da0ce9d70606e10889d17f481842586132d88Eric Christopher } 626f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 627f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth disableSROA(CostIt); 6288e2da0ce9d70606e10889d17f481842586132d88Eric Christopher } 6295c655413cf9466c29e38204ab3f19b33fffd7996Andrew Trick 630f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return false; 6314e8af6db184118638c21f713ad98e3292c6891c9Eric Christopher} 6324e8af6db184118638c21f713ad98e3292c6891c9Eric Christopher 633ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruthbool CallAnalyzer::visitExtractValue(ExtractValueInst &I) { 634ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth // Constant folding for extract value is trivial. 635ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth Constant *C = dyn_cast<Constant>(I.getAggregateOperand()); 636ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth if (!C) 637ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth C = SimplifiedValues.lookup(I.getAggregateOperand()); 638ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth if (C) { 639ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth SimplifiedValues[&I] = ConstantExpr::getExtractValue(C, I.getIndices()); 640ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth return true; 641ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth } 642ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth 643ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth // SROA can look through these but give them a cost. 644ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth return false; 645ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth} 646ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth 647ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruthbool CallAnalyzer::visitInsertValue(InsertValueInst &I) { 648ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth // Constant folding for insert value is trivial. 649ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth Constant *AggC = dyn_cast<Constant>(I.getAggregateOperand()); 650ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth if (!AggC) 651ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth AggC = SimplifiedValues.lookup(I.getAggregateOperand()); 652ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth Constant *InsertedC = dyn_cast<Constant>(I.getInsertedValueOperand()); 653ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth if (!InsertedC) 654ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth InsertedC = SimplifiedValues.lookup(I.getInsertedValueOperand()); 655ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth if (AggC && InsertedC) { 656ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth SimplifiedValues[&I] = ConstantExpr::getInsertValue(AggC, InsertedC, 657ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth I.getIndices()); 658ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth return true; 659ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth } 660ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth 661ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth // SROA can look through these but give them a cost. 662ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth return false; 663ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth} 664ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth 665ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth/// \brief Try to simplify a call site. 666ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth/// 667ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth/// Takes a concrete function and callsite and tries to actually simplify it by 668ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth/// analyzing the arguments and call itself with instsimplify. Returns true if 669ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth/// it has simplified the callsite to some other entity (a constant), making it 670ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth/// free. 671ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruthbool CallAnalyzer::simplifyCallSite(Function *F, CallSite CS) { 672ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth // FIXME: Using the instsimplify logic directly for this is inefficient 673ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth // because we have to continually rebuild the argument list even when no 674ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth // simplifications can be performed. Until that is fixed with remapping 675ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth // inside of instsimplify, directly constant fold calls here. 676ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth if (!canConstantFoldCallTo(F)) 677ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth return false; 678ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth 679ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth // Try to re-map the arguments to constants. 680ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth SmallVector<Constant *, 4> ConstantArgs; 681ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth ConstantArgs.reserve(CS.arg_size()); 682ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end(); 683ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth I != E; ++I) { 684ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth Constant *C = dyn_cast<Constant>(*I); 685ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth if (!C) 686ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth C = dyn_cast_or_null<Constant>(SimplifiedValues.lookup(*I)); 687ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth if (!C) 688ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth return false; // This argument doesn't map to a constant. 689ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth 690ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth ConstantArgs.push_back(C); 691ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth } 692ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth if (Constant *C = ConstantFoldCall(F, ConstantArgs)) { 693ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth SimplifiedValues[CS.getInstruction()] = C; 694ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth return true; 695ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth } 696ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth 697ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth return false; 698ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth} 699ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth 700f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::visitCallSite(CallSite CS) { 701f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (CS.isCall() && cast<CallInst>(CS.getInstruction())->canReturnTwice() && 702831737d329a727f53a1fb0572f7b7a8127208881Bill Wendling !F.getAttributes().hasAttribute(AttributeSet::FunctionIndex, 703831737d329a727f53a1fb0572f7b7a8127208881Bill Wendling Attribute::ReturnsTwice)) { 704f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // This aborts the entire analysis. 705f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth ExposesReturnsTwice = true; 706f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return false; 7074e8af6db184118638c21f713ad98e3292c6891c9Eric Christopher } 70867ae13575900e8efd056672987249fd0adbf5e73James Molloy if (CS.isCall() && 70967ae13575900e8efd056672987249fd0adbf5e73James Molloy cast<CallInst>(CS.getInstruction())->hasFnAttr(Attribute::NoDuplicate)) 71067ae13575900e8efd056672987249fd0adbf5e73James Molloy ContainsNoDuplicateCall = true; 7115c655413cf9466c29e38204ab3f19b33fffd7996Andrew Trick 712ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth if (Function *F = CS.getCalledFunction()) { 713ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth // When we have a concrete function, first try to simplify it directly. 714ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth if (simplifyCallSite(F, CS)) 715ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth return true; 716274d377ea68195989c3238fe96ce2ca812a12fafChandler Carruth 717ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth // Next check if it is an intrinsic we know about. 718ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth // FIXME: Lift this into part of the InstVisitor. 719ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(CS.getInstruction())) { 720ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth switch (II->getIntrinsicID()) { 721ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth default: 722ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth return Base::visitCallSite(CS); 723ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth 724ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth case Intrinsic::memset: 725ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth case Intrinsic::memcpy: 726ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth case Intrinsic::memmove: 727ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth // SROA can usually chew through these intrinsics, but they aren't free. 728ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth return false; 729ba94204e94ba88f7c897a5a59d1c770b7dc3d04eChandler Carruth } 730f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 7314e8af6db184118638c21f713ad98e3292c6891c9Eric Christopher 732f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (F == CS.getInstruction()->getParent()->getParent()) { 733f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // This flag will fully abort the analysis, so don't bother with anything 734f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // else. 73592df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem IsRecursiveCall = true; 736f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return false; 737f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 7384e8af6db184118638c21f713ad98e3292c6891c9Eric Christopher 73913086a658ae06046ded902229f9918b8bad505bdChandler Carruth if (TTI.isLoweredToCall(F)) { 740f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // We account for the average 1 instruction per call argument setup 741f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // here. 742f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Cost += CS.arg_size() * InlineConstants::InstrCost; 7434e8af6db184118638c21f713ad98e3292c6891c9Eric Christopher 744f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Everything other than inline ASM will also have a significant cost 745f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // merely from making the call. 746f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (!isa<InlineAsm>(CS.getCalledValue())) 747f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Cost += InlineConstants::CallPenalty; 748f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 7495c655413cf9466c29e38204ab3f19b33fffd7996Andrew Trick 750f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return Base::visitCallSite(CS); 751f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 752f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 753f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Otherwise we're in a very special case -- an indirect function call. See 754f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // if we can be particularly clever about this. 755f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *Callee = CS.getCalledValue(); 756f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 757f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // First, pay the price of the argument setup. We account for the average 758f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // 1 instruction per call argument setup here. 759f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Cost += CS.arg_size() * InlineConstants::InstrCost; 760f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 761f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Next, check if this happens to be an indirect function call to a known 762f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // function in this inline context. If not, we've done all we can. 763f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Function *F = dyn_cast_or_null<Function>(SimplifiedValues.lookup(Callee)); 764f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (!F) 765f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return Base::visitCallSite(CS); 766f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 767f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // If we have a constant that we are calling as a function, we can peer 768f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // through it and see the function target. This happens not infrequently 769f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // during devirtualization and so we want to give it a hefty bonus for 770f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // inlining, but cap that bonus in the event that inlining wouldn't pan 771f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // out. Pretend to inline the function, with a custom threshold. 7728d6c0f4deeb0f2ff671df7ae92b75ee1e39acd37Chandler Carruth CallAnalyzer CA(TD, TTI, *F, InlineConstants::IndirectCallThreshold); 773f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (CA.analyzeCall(CS)) { 774f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // We were able to inline the indirect call! Subtract the cost from the 775f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // bonus we want to apply, but don't go below zero. 776f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Cost -= std::max(0, InlineConstants::IndirectCallThreshold - CA.getCost()); 777f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 778f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 779f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return Base::visitCallSite(CS); 7804e8af6db184118638c21f713ad98e3292c6891c9Eric Christopher} 7814e8af6db184118638c21f713ad98e3292c6891c9Eric Christopher 782f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::visitInstruction(Instruction &I) { 783d5003cafd6fc86acaf8e09ef0ca1dc899da8850eChandler Carruth // Some instructions are free. All of the free intrinsics can also be 784d5003cafd6fc86acaf8e09ef0ca1dc899da8850eChandler Carruth // handled by SROA, etc. 785b5da8a4ae1fbd8e4ffab06cfeb5b32a94d0381bbChandler Carruth if (TargetTransformInfo::TCC_Free == TTI.getUserCost(&I)) 786d5003cafd6fc86acaf8e09ef0ca1dc899da8850eChandler Carruth return true; 787d5003cafd6fc86acaf8e09ef0ca1dc899da8850eChandler Carruth 788f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // We found something we don't understand or can't handle. Mark any SROA-able 789f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // values in the operand list as no longer viable. 790f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth for (User::op_iterator OI = I.op_begin(), OE = I.op_end(); OI != OE; ++OI) 791f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth disableSROA(*OI); 792f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 793f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return false; 7948e2da0ce9d70606e10889d17f481842586132d88Eric Christopher} 79574fa7327d690e6ceda6ce77e4e5b8ef75cb12538Kenneth Uildriks 796f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 797f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// \brief Analyze a basic block for its contribution to the inline cost. 798f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// 799f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// This method walks the analyzer over every instruction in the given basic 800f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// block and accounts for their cost during inlining at this callsite. It 801f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// aborts early if the threshold has been exceeded or an impossible to inline 802f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// construct has been detected. It returns false if inlining is no longer 803f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// viable, and true if inlining remains viable. 804f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::analyzeBlock(BasicBlock *BB) { 805f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth for (BasicBlock::iterator I = BB->begin(), E = llvm::prior(BB->end()); 806f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth I != E; ++I) { 807f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth ++NumInstructions; 808f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (isa<ExtractElementInst>(I) || I->getType()->isVectorTy()) 809f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth ++NumVectorInstructions; 810f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 811f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // If the instruction simplified to a constant, there is no cost to this 812f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // instruction. Visit the instructions using our InstVisitor to account for 813f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // all of the per-instruction logic. The visit tree returns true if we 814f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // consumed the instruction in any way, and false if the instruction's base 815f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // cost should count against inlining. 816f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (Base::visit(I)) 817f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth ++NumInstructionsSimplified; 818f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth else 819f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Cost += InlineConstants::InstrCost; 820f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 821f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // If the visit this instruction detected an uninlinable pattern, abort. 82292df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem if (IsRecursiveCall || ExposesReturnsTwice || HasDynamicAlloca) 82392df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem return false; 82492df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem 82592df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem // If the caller is a recursive function then we don't want to inline 82692df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem // functions which allocate a lot of stack space because it would increase 82792df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem // the caller stack usage dramatically. 82892df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem if (IsCallerRecursive && 82992df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem AllocatedSize > InlineConstants::TotalAllocaSizeRecursiveCaller) 830f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return false; 831f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 832f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (NumVectorInstructions > NumInstructions/2) 833f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth VectorBonus = FiftyPercentVectorBonus; 834f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth else if (NumVectorInstructions > NumInstructions/10) 835f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth VectorBonus = TenPercentVectorBonus; 836f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth else 837f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth VectorBonus = 0; 838f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 839f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Check if we've past the threshold so we don't spin in huge basic 840f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // blocks that will never inline. 84128f872f8a1945635f30763805c1418a90c6b345eBob Wilson if (Cost > (Threshold + VectorBonus)) 842f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return false; 843f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 844f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 845f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return true; 846752e2590585227f6f10e80978f587915d9adb2adDavid Chisnall} 847752e2590585227f6f10e80978f587915d9adb2adDavid Chisnall 848f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// \brief Compute the base pointer and cumulative constant offsets for V. 849f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// 850f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// This strips all constant offsets off of V, leaving it the base pointer, and 851f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// accumulates the total constant offset applied in the returned constant. It 852f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// returns 0 if V is not a pointer, and returns the constant '0' if there are 853f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// no constant offsets applied. 854f2286b0152f0b942e82d8e809186e5cc0d247131Chandler CarruthConstantInt *CallAnalyzer::stripAndComputeInBoundsConstantOffsets(Value *&V) { 855f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (!TD || !V->getType()->isPointerTy()) 856f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return 0; 857f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 858426c2bf5cdd2173e4a33aea8cb92cf684a724f4bChandler Carruth unsigned IntPtrWidth = TD->getPointerSizeInBits(); 859f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth APInt Offset = APInt::getNullValue(IntPtrWidth); 860f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 861f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Even though we don't look through PHI nodes, we could be called on an 862f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // instruction in an unreachable block, which may be on a cycle. 863f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SmallPtrSet<Value *, 4> Visited; 864f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Visited.insert(V); 865f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth do { 866f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) { 867f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (!GEP->isInBounds() || !accumulateGEPOffset(*GEP, Offset)) 868f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return 0; 869f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth V = GEP->getPointerOperand(); 870f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } else if (Operator::getOpcode(V) == Instruction::BitCast) { 871f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth V = cast<Operator>(V)->getOperand(0); 872f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) { 873f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (GA->mayBeOverridden()) 874f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth break; 875f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth V = GA->getAliasee(); 876f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } else { 877f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth break; 878f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 879f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth assert(V->getType()->isPointerTy() && "Unexpected operand type!"); 880f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } while (Visited.insert(V)); 881e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman 882ece6c6bb6329748b92403c06ac87f45c43485911Chandler Carruth Type *IntPtrTy = TD->getIntPtrType(V->getContext()); 883f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return cast<ConstantInt>(ConstantInt::get(IntPtrTy, Offset)); 884f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth} 885e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman 886f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// \brief Analyze a call site for potential inlining. 887f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// 888f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// Returns true if inlining this call is viable, and false if it is not 889f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// viable. It computes the cost and adjusts the threshold based on numerous 890f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// factors and heuristics. If this method returns false but the computed cost 891f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// is below the computed threshold, then inlining was forcibly disabled by 892593423f7461fbbbf752ff013bf20c19ef95d3435Bob Wilson/// some artifact of the routine. 893f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthbool CallAnalyzer::analyzeCall(CallSite CS) { 894d6fc26217e194372cabe4ef9e2514beac511a943Chandler Carruth ++NumCallsAnalyzed; 895d6fc26217e194372cabe4ef9e2514beac511a943Chandler Carruth 896f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Track whether the post-inlining function would have more than one basic 897f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // block. A single basic block is often intended for inlining. Balloon the 898f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // threshold by 50% until we pass the single-BB phase. 899f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool SingleBB = true; 900f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth int SingleBBBonus = Threshold / 2; 901f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Threshold += SingleBBBonus; 902f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 90328f872f8a1945635f30763805c1418a90c6b345eBob Wilson // Perform some tweaks to the cost and threshold based on the direct 90428f872f8a1945635f30763805c1418a90c6b345eBob Wilson // callsite information. 90528f872f8a1945635f30763805c1418a90c6b345eBob Wilson 90628f872f8a1945635f30763805c1418a90c6b345eBob Wilson // We want to more aggressively inline vector-dense kernels, so up the 90728f872f8a1945635f30763805c1418a90c6b345eBob Wilson // threshold, and we'll lower it if the % of vector instructions gets too 90828f872f8a1945635f30763805c1418a90c6b345eBob Wilson // low. 90928f872f8a1945635f30763805c1418a90c6b345eBob Wilson assert(NumInstructions == 0); 91028f872f8a1945635f30763805c1418a90c6b345eBob Wilson assert(NumVectorInstructions == 0); 91128f872f8a1945635f30763805c1418a90c6b345eBob Wilson FiftyPercentVectorBonus = Threshold; 91228f872f8a1945635f30763805c1418a90c6b345eBob Wilson TenPercentVectorBonus = Threshold / 2; 91328f872f8a1945635f30763805c1418a90c6b345eBob Wilson 91428f872f8a1945635f30763805c1418a90c6b345eBob Wilson // Give out bonuses per argument, as the instructions setting them up will 91528f872f8a1945635f30763805c1418a90c6b345eBob Wilson // be gone after inlining. 91628f872f8a1945635f30763805c1418a90c6b345eBob Wilson for (unsigned I = 0, E = CS.arg_size(); I != E; ++I) { 91728f872f8a1945635f30763805c1418a90c6b345eBob Wilson if (TD && CS.isByValArgument(I)) { 91828f872f8a1945635f30763805c1418a90c6b345eBob Wilson // We approximate the number of loads and stores needed by dividing the 91928f872f8a1945635f30763805c1418a90c6b345eBob Wilson // size of the byval type by the target's pointer size. 92028f872f8a1945635f30763805c1418a90c6b345eBob Wilson PointerType *PTy = cast<PointerType>(CS.getArgument(I)->getType()); 92128f872f8a1945635f30763805c1418a90c6b345eBob Wilson unsigned TypeSize = TD->getTypeSizeInBits(PTy->getElementType()); 92228f872f8a1945635f30763805c1418a90c6b345eBob Wilson unsigned PointerSize = TD->getPointerSizeInBits(); 92328f872f8a1945635f30763805c1418a90c6b345eBob Wilson // Ceiling division. 92428f872f8a1945635f30763805c1418a90c6b345eBob Wilson unsigned NumStores = (TypeSize + PointerSize - 1) / PointerSize; 92528f872f8a1945635f30763805c1418a90c6b345eBob Wilson 92628f872f8a1945635f30763805c1418a90c6b345eBob Wilson // If it generates more than 8 stores it is likely to be expanded as an 92728f872f8a1945635f30763805c1418a90c6b345eBob Wilson // inline memcpy so we take that as an upper bound. Otherwise we assume 92828f872f8a1945635f30763805c1418a90c6b345eBob Wilson // one load and one store per word copied. 92928f872f8a1945635f30763805c1418a90c6b345eBob Wilson // FIXME: The maxStoresPerMemcpy setting from the target should be used 93028f872f8a1945635f30763805c1418a90c6b345eBob Wilson // here instead of a magic number of 8, but it's not available via 93128f872f8a1945635f30763805c1418a90c6b345eBob Wilson // DataLayout. 93228f872f8a1945635f30763805c1418a90c6b345eBob Wilson NumStores = std::min(NumStores, 8U); 93328f872f8a1945635f30763805c1418a90c6b345eBob Wilson 93428f872f8a1945635f30763805c1418a90c6b345eBob Wilson Cost -= 2 * NumStores * InlineConstants::InstrCost; 93528f872f8a1945635f30763805c1418a90c6b345eBob Wilson } else { 93628f872f8a1945635f30763805c1418a90c6b345eBob Wilson // For non-byval arguments subtract off one instruction per call 93728f872f8a1945635f30763805c1418a90c6b345eBob Wilson // argument. 93828f872f8a1945635f30763805c1418a90c6b345eBob Wilson Cost -= InlineConstants::InstrCost; 939b6fdd022b7414f916ba7b08560a0f55e14863326Benjamin Kramer } 94028f872f8a1945635f30763805c1418a90c6b345eBob Wilson } 941f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 94228f872f8a1945635f30763805c1418a90c6b345eBob Wilson // If there is only one call of the function, and it has internal linkage, 94328f872f8a1945635f30763805c1418a90c6b345eBob Wilson // the cost of inlining it drops dramatically. 94467ae13575900e8efd056672987249fd0adbf5e73James Molloy bool OnlyOneCallAndLocalLinkage = F.hasLocalLinkage() && F.hasOneUse() && 94567ae13575900e8efd056672987249fd0adbf5e73James Molloy &F == CS.getCalledFunction(); 94667ae13575900e8efd056672987249fd0adbf5e73James Molloy if (OnlyOneCallAndLocalLinkage) 94728f872f8a1945635f30763805c1418a90c6b345eBob Wilson Cost += InlineConstants::LastCallToStaticBonus; 94828f872f8a1945635f30763805c1418a90c6b345eBob Wilson 94928f872f8a1945635f30763805c1418a90c6b345eBob Wilson // If the instruction after the call, or if the normal destination of the 95028f872f8a1945635f30763805c1418a90c6b345eBob Wilson // invoke is an unreachable instruction, the function is noreturn. As such, 95128f872f8a1945635f30763805c1418a90c6b345eBob Wilson // there is little point in inlining this unless there is literally zero 95228f872f8a1945635f30763805c1418a90c6b345eBob Wilson // cost. 95328f872f8a1945635f30763805c1418a90c6b345eBob Wilson Instruction *Instr = CS.getInstruction(); 95428f872f8a1945635f30763805c1418a90c6b345eBob Wilson if (InvokeInst *II = dyn_cast<InvokeInst>(Instr)) { 95528f872f8a1945635f30763805c1418a90c6b345eBob Wilson if (isa<UnreachableInst>(II->getNormalDest()->begin())) 956f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Threshold = 1; 95728f872f8a1945635f30763805c1418a90c6b345eBob Wilson } else if (isa<UnreachableInst>(++BasicBlock::iterator(Instr))) 95828f872f8a1945635f30763805c1418a90c6b345eBob Wilson Threshold = 1; 959f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 96028f872f8a1945635f30763805c1418a90c6b345eBob Wilson // If this function uses the coldcc calling convention, prefer not to inline 96128f872f8a1945635f30763805c1418a90c6b345eBob Wilson // it. 96228f872f8a1945635f30763805c1418a90c6b345eBob Wilson if (F.getCallingConv() == CallingConv::Cold) 96328f872f8a1945635f30763805c1418a90c6b345eBob Wilson Cost += InlineConstants::ColdccPenalty; 964f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 96528f872f8a1945635f30763805c1418a90c6b345eBob Wilson // Check if we're done. This can happen due to bonuses and penalties. 96628f872f8a1945635f30763805c1418a90c6b345eBob Wilson if (Cost > Threshold) 96728f872f8a1945635f30763805c1418a90c6b345eBob Wilson return false; 9685c655413cf9466c29e38204ab3f19b33fffd7996Andrew Trick 969f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (F.empty()) 970f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return true; 971e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman 97292df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem Function *Caller = CS.getInstruction()->getParent()->getParent(); 97392df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem // Check if the caller function is recursive itself. 97492df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem for (Value::use_iterator U = Caller->use_begin(), E = Caller->use_end(); 97592df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem U != E; ++U) { 97692df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem CallSite Site(cast<Value>(*U)); 97792df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem if (!Site) 97892df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem continue; 97992df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem Instruction *I = Site.getInstruction(); 98092df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem if (I->getParent()->getParent() == Caller) { 98192df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem IsCallerRecursive = true; 98292df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem break; 98392df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem } 98492df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem } 98592df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem 986f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Track whether we've seen a return instruction. The first return 987f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // instruction is free, as at least one will usually disappear in inlining. 988f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool HasReturn = false; 989f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 990f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Populate our simplified values by mapping from function arguments to call 991f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // arguments with known important simplifications. 992f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth CallSite::arg_iterator CAI = CS.arg_begin(); 993f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth for (Function::arg_iterator FAI = F.arg_begin(), FAE = F.arg_end(); 994f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth FAI != FAE; ++FAI, ++CAI) { 995f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth assert(CAI != CS.arg_end()); 996f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (Constant *C = dyn_cast<Constant>(CAI)) 997f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SimplifiedValues[FAI] = C; 998f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 999f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *PtrArg = *CAI; 1000f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (ConstantInt *C = stripAndComputeInBoundsConstantOffsets(PtrArg)) { 1001f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth ConstantOffsetPtrs[FAI] = std::make_pair(PtrArg, C->getValue()); 1002f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 1003f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // We can SROA any pointer arguments derived from alloca instructions. 1004f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (isa<AllocaInst>(PtrArg)) { 1005f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SROAArgValues[FAI] = PtrArg; 1006f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SROAArgCosts[PtrArg] = 0; 1007f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 1008f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 1009f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 1010f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth NumConstantArgs = SimplifiedValues.size(); 1011f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth NumConstantOffsetPtrArgs = ConstantOffsetPtrs.size(); 1012f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth NumAllocaArgs = SROAArgValues.size(); 1013f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 1014f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // The worklist of live basic blocks in the callee *after* inlining. We avoid 1015f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // adding basic blocks of the callee which can be proven to be dead for this 1016f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // particular call site in order to get more accurate cost estimates. This 1017f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // requires a somewhat heavyweight iteration pattern: we need to walk the 1018f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // basic blocks in a breadth-first order as we insert live successors. To 1019f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // accomplish this, prioritizing for small iterations because we exit after 1020f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // crossing our threshold, we use a small-size optimized SetVector. 1021f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth typedef SetVector<BasicBlock *, SmallVector<BasicBlock *, 16>, 1022f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SmallPtrSet<BasicBlock *, 16> > BBSetVector; 1023f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth BBSetVector BBWorklist; 1024f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth BBWorklist.insert(&F.getEntryBlock()); 1025f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Note that we *must not* cache the size, this loop grows the worklist. 1026f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth for (unsigned Idx = 0; Idx != BBWorklist.size(); ++Idx) { 1027f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Bail out the moment we cross the threshold. This means we'll under-count 1028f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // the cost, but only when undercounting doesn't matter. 102928f872f8a1945635f30763805c1418a90c6b345eBob Wilson if (Cost > (Threshold + VectorBonus)) 1030f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth break; 1031f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 1032f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth BasicBlock *BB = BBWorklist[Idx]; 1033f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (BB->empty()) 1034f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth continue; 1035e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman 1036f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Handle the terminator cost here where we can track returns and other 1037f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // function-wide constructs. 1038f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth TerminatorInst *TI = BB->getTerminator(); 1039f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 1040f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // We never want to inline functions that contain an indirectbr. This is 1041f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // incorrect because all the blockaddress's (in static global initializers 104292df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem // for example) would be referring to the original function, and this 104392df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem // indirect jump would jump from the inlined copy of the function into the 104492df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem // original function which is extremely undefined behavior. 1045f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // FIXME: This logic isn't really right; we can safely inline functions 1046f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // with indirectbr's as long as no other function or global references the 1047f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // blockaddress of a block within the current function. And as a QOI issue, 1048f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // if someone is using a blockaddress without an indirectbr, and that 1049f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // reference somehow ends up in another function or global, we probably 1050f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // don't want to inline this function. 1051f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (isa<IndirectBrInst>(TI)) 1052f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return false; 10535c655413cf9466c29e38204ab3f19b33fffd7996Andrew Trick 1054f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (!HasReturn && isa<ReturnInst>(TI)) 1055f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth HasReturn = true; 1056f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth else 1057f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Cost += InlineConstants::InstrCost; 1058e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman 1059f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Analyze the cost of this block. If we blow through the threshold, this 1060f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // returns false, and we can bail on out. 1061f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (!analyzeBlock(BB)) { 106292df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem if (IsRecursiveCall || ExposesReturnsTwice || HasDynamicAlloca) 1063f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return false; 106492df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem 106592df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem // If the caller is a recursive function then we don't want to inline 106692df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem // functions which allocate a lot of stack space because it would increase 106792df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem // the caller stack usage dramatically. 106892df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem if (IsCallerRecursive && 106992df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem AllocatedSize > InlineConstants::TotalAllocaSizeRecursiveCaller) 107092df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem return false; 107192df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem 1072f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth break; 1073f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 10745c655413cf9466c29e38204ab3f19b33fffd7996Andrew Trick 1075f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Add in the live successors by first checking whether we have terminator 1076f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // that may be simplified based on the values simplified by this call. 1077f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (BranchInst *BI = dyn_cast<BranchInst>(TI)) { 1078f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (BI->isConditional()) { 1079f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *Cond = BI->getCondition(); 1080f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (ConstantInt *SimpleCond 1081f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth = dyn_cast_or_null<ConstantInt>(SimplifiedValues.lookup(Cond))) { 1082f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth BBWorklist.insert(BI->getSuccessor(SimpleCond->isZero() ? 1 : 0)); 1083f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth continue; 1084f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 1085f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 1086f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } else if (SwitchInst *SI = dyn_cast<SwitchInst>(TI)) { 1087f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Value *Cond = SI->getCondition(); 1088f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (ConstantInt *SimpleCond 1089f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth = dyn_cast_or_null<ConstantInt>(SimplifiedValues.lookup(Cond))) { 1090f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth BBWorklist.insert(SI->findCaseValue(SimpleCond).getCaseSuccessor()); 1091f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth continue; 1092f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 1093f84755b8360d13b1d19df821d9e8692aac7e9b87Chris Lattner } 1094e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman 1095f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // If we're unable to select a particular successor, just count all of 1096f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // them. 109792df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem for (unsigned TIdx = 0, TSize = TI->getNumSuccessors(); TIdx != TSize; 109892df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem ++TIdx) 1099f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth BBWorklist.insert(TI->getSuccessor(TIdx)); 1100f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth 1101f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // If we had any successors at this point, than post-inlining is likely to 1102f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // have them as well. Note that we assume any basic blocks which existed 1103f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // due to branches or switches which folded above will also fold after 1104f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // inlining. 1105f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (SingleBB && TI->getNumSuccessors() > 1) { 1106f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Take off the bonus we applied to the threshold. 1107f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Threshold -= SingleBBBonus; 1108f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth SingleBB = false; 1109f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 1110e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman } 1111e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman 111267ae13575900e8efd056672987249fd0adbf5e73James Molloy // If this is a noduplicate call, we can still inline as long as 111367ae13575900e8efd056672987249fd0adbf5e73James Molloy // inlining this would cause the removal of the caller (so the instruction 111467ae13575900e8efd056672987249fd0adbf5e73James Molloy // is not actually duplicated, just moved). 111567ae13575900e8efd056672987249fd0adbf5e73James Molloy if (!OnlyOneCallAndLocalLinkage && ContainsNoDuplicateCall) 111667ae13575900e8efd056672987249fd0adbf5e73James Molloy return false; 111767ae13575900e8efd056672987249fd0adbf5e73James Molloy 1118f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth Threshold += VectorBonus; 1119e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman 112028f872f8a1945635f30763805c1418a90c6b345eBob Wilson return Cost < Threshold; 1121f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth} 11225c655413cf9466c29e38204ab3f19b33fffd7996Andrew Trick 1123286c4dc355b8be6806081b23c3097485821c7642Manman Ren#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 1124f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth/// \brief Dump stats about this call's analysis. 1125f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruthvoid CallAnalyzer::dump() { 1126f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth#define DEBUG_PRINT_STAT(x) llvm::dbgs() << " " #x ": " << x << "\n" 1127f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DEBUG_PRINT_STAT(NumConstantArgs); 1128f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DEBUG_PRINT_STAT(NumConstantOffsetPtrArgs); 1129f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DEBUG_PRINT_STAT(NumAllocaArgs); 1130f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DEBUG_PRINT_STAT(NumConstantPtrCmps); 1131f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DEBUG_PRINT_STAT(NumConstantPtrDiffs); 1132f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DEBUG_PRINT_STAT(NumInstructionsSimplified); 1133f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DEBUG_PRINT_STAT(SROACostSavings); 1134f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DEBUG_PRINT_STAT(SROACostSavingsLost); 113567ae13575900e8efd056672987249fd0adbf5e73James Molloy DEBUG_PRINT_STAT(ContainsNoDuplicateCall); 1136f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth#undef DEBUG_PRINT_STAT 1137e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman} 1138cc77eece74c8db09acc2af425e7e6c88a5bb30d1Manman Ren#endif 1139f7477470d37ee2ab9075eaee4745fa084d424ab8Jakob Stoklund Olesen 114086953b5795007eaa98838297360a6987e33e92e7Chandler CarruthINITIALIZE_PASS_BEGIN(InlineCostAnalysis, "inline-cost", "Inline Cost Analysis", 114186953b5795007eaa98838297360a6987e33e92e7Chandler Carruth true, true) 11428d6c0f4deeb0f2ff671df7ae92b75ee1e39acd37Chandler CarruthINITIALIZE_AG_DEPENDENCY(TargetTransformInfo) 114386953b5795007eaa98838297360a6987e33e92e7Chandler CarruthINITIALIZE_PASS_END(InlineCostAnalysis, "inline-cost", "Inline Cost Analysis", 114486953b5795007eaa98838297360a6987e33e92e7Chandler Carruth true, true) 114586953b5795007eaa98838297360a6987e33e92e7Chandler Carruth 114686953b5795007eaa98838297360a6987e33e92e7Chandler Carruthchar InlineCostAnalysis::ID = 0; 114786953b5795007eaa98838297360a6987e33e92e7Chandler Carruth 114886953b5795007eaa98838297360a6987e33e92e7Chandler CarruthInlineCostAnalysis::InlineCostAnalysis() : CallGraphSCCPass(ID), TD(0) {} 114986953b5795007eaa98838297360a6987e33e92e7Chandler Carruth 115086953b5795007eaa98838297360a6987e33e92e7Chandler CarruthInlineCostAnalysis::~InlineCostAnalysis() {} 115186953b5795007eaa98838297360a6987e33e92e7Chandler Carruth 115286953b5795007eaa98838297360a6987e33e92e7Chandler Carruthvoid InlineCostAnalysis::getAnalysisUsage(AnalysisUsage &AU) const { 115386953b5795007eaa98838297360a6987e33e92e7Chandler Carruth AU.setPreservesAll(); 11548d6c0f4deeb0f2ff671df7ae92b75ee1e39acd37Chandler Carruth AU.addRequired<TargetTransformInfo>(); 115586953b5795007eaa98838297360a6987e33e92e7Chandler Carruth CallGraphSCCPass::getAnalysisUsage(AU); 115686953b5795007eaa98838297360a6987e33e92e7Chandler Carruth} 115786953b5795007eaa98838297360a6987e33e92e7Chandler Carruth 115886953b5795007eaa98838297360a6987e33e92e7Chandler Carruthbool InlineCostAnalysis::runOnSCC(CallGraphSCC &SCC) { 115986953b5795007eaa98838297360a6987e33e92e7Chandler Carruth TD = getAnalysisIfAvailable<DataLayout>(); 11608d6c0f4deeb0f2ff671df7ae92b75ee1e39acd37Chandler Carruth TTI = &getAnalysis<TargetTransformInfo>(); 116186953b5795007eaa98838297360a6987e33e92e7Chandler Carruth return false; 116286953b5795007eaa98838297360a6987e33e92e7Chandler Carruth} 116386953b5795007eaa98838297360a6987e33e92e7Chandler Carruth 116486953b5795007eaa98838297360a6987e33e92e7Chandler CarruthInlineCost InlineCostAnalysis::getInlineCost(CallSite CS, int Threshold) { 1165b381578fcb5fea988f661dbbee9747b8fd55c5fbDavid Chisnall return getInlineCost(CS, CS.getCalledFunction(), Threshold); 1166b381578fcb5fea988f661dbbee9747b8fd55c5fbDavid Chisnall} 1167f7477470d37ee2ab9075eaee4745fa084d424ab8Jakob Stoklund Olesen 116886953b5795007eaa98838297360a6987e33e92e7Chandler CarruthInlineCost InlineCostAnalysis::getInlineCost(CallSite CS, Function *Callee, 1169b381578fcb5fea988f661dbbee9747b8fd55c5fbDavid Chisnall int Threshold) { 117028f872f8a1945635f30763805c1418a90c6b345eBob Wilson // Cannot inline indirect calls. 117128f872f8a1945635f30763805c1418a90c6b345eBob Wilson if (!Callee) 117228f872f8a1945635f30763805c1418a90c6b345eBob Wilson return llvm::InlineCost::getNever(); 117328f872f8a1945635f30763805c1418a90c6b345eBob Wilson 117428f872f8a1945635f30763805c1418a90c6b345eBob Wilson // Calls to functions with always-inline attributes should be inlined 117528f872f8a1945635f30763805c1418a90c6b345eBob Wilson // whenever possible. 1176831737d329a727f53a1fb0572f7b7a8127208881Bill Wendling if (Callee->getAttributes().hasAttribute(AttributeSet::FunctionIndex, 1177831737d329a727f53a1fb0572f7b7a8127208881Bill Wendling Attribute::AlwaysInline)) { 117828f872f8a1945635f30763805c1418a90c6b345eBob Wilson if (isInlineViable(*Callee)) 117928f872f8a1945635f30763805c1418a90c6b345eBob Wilson return llvm::InlineCost::getAlways(); 118028f872f8a1945635f30763805c1418a90c6b345eBob Wilson return llvm::InlineCost::getNever(); 118128f872f8a1945635f30763805c1418a90c6b345eBob Wilson } 118228f872f8a1945635f30763805c1418a90c6b345eBob Wilson 1183f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Don't inline functions which can be redefined at link-time to mean 1184f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // something else. Don't inline functions marked noinline or call sites 1185f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // marked noinline. 118628f872f8a1945635f30763805c1418a90c6b345eBob Wilson if (Callee->mayBeOverridden() || 1187831737d329a727f53a1fb0572f7b7a8127208881Bill Wendling Callee->getAttributes().hasAttribute(AttributeSet::FunctionIndex, 1188831737d329a727f53a1fb0572f7b7a8127208881Bill Wendling Attribute::NoInline) || 11896765834754cbb3cb0f15b4b15e98c5e73fa50066Bill Wendling CS.isNoInline()) 1190f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return llvm::InlineCost::getNever(); 1191f7477470d37ee2ab9075eaee4745fa084d424ab8Jakob Stoklund Olesen 119292df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem DEBUG(llvm::dbgs() << " Analyzing call of " << Callee->getName() 119392df026f0da91dc65ef6186e97ff87b1f53e8cd0Nadav Rotem << "...\n"); 119444b04a5f4ac8a2b9b3208a937f2ba36bcf7aa40fChris Lattner 11958d6c0f4deeb0f2ff671df7ae92b75ee1e39acd37Chandler Carruth CallAnalyzer CA(TD, *TTI, *Callee, Threshold); 1196f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth bool ShouldInline = CA.analyzeCall(CS); 11975c655413cf9466c29e38204ab3f19b33fffd7996Andrew Trick 1198f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DEBUG(CA.dump()); 119944b04a5f4ac8a2b9b3208a937f2ba36bcf7aa40fChris Lattner 1200f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // Check if there was a reason to force inlining or no inlining. 1201f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (!ShouldInline && CA.getCost() < CA.getThreshold()) 1202f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return InlineCost::getNever(); 120328f872f8a1945635f30763805c1418a90c6b345eBob Wilson if (ShouldInline && CA.getCost() >= CA.getThreshold()) 1204f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return InlineCost::getAlways(); 12055c655413cf9466c29e38204ab3f19b33fffd7996Andrew Trick 1206f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth return llvm::InlineCost::get(CA.getCost(), CA.getThreshold()); 1207f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth} 120828f872f8a1945635f30763805c1418a90c6b345eBob Wilson 120986953b5795007eaa98838297360a6987e33e92e7Chandler Carruthbool InlineCostAnalysis::isInlineViable(Function &F) { 121086953b5795007eaa98838297360a6987e33e92e7Chandler Carruth bool ReturnsTwice = 121186953b5795007eaa98838297360a6987e33e92e7Chandler Carruth F.getAttributes().hasAttribute(AttributeSet::FunctionIndex, 121286953b5795007eaa98838297360a6987e33e92e7Chandler Carruth Attribute::ReturnsTwice); 121328f872f8a1945635f30763805c1418a90c6b345eBob Wilson for (Function::iterator BI = F.begin(), BE = F.end(); BI != BE; ++BI) { 121428f872f8a1945635f30763805c1418a90c6b345eBob Wilson // Disallow inlining of functions which contain an indirect branch. 121528f872f8a1945635f30763805c1418a90c6b345eBob Wilson if (isa<IndirectBrInst>(BI->getTerminator())) 121628f872f8a1945635f30763805c1418a90c6b345eBob Wilson return false; 121728f872f8a1945635f30763805c1418a90c6b345eBob Wilson 121828f872f8a1945635f30763805c1418a90c6b345eBob Wilson for (BasicBlock::iterator II = BI->begin(), IE = BI->end(); II != IE; 121928f872f8a1945635f30763805c1418a90c6b345eBob Wilson ++II) { 122028f872f8a1945635f30763805c1418a90c6b345eBob Wilson CallSite CS(II); 122128f872f8a1945635f30763805c1418a90c6b345eBob Wilson if (!CS) 122228f872f8a1945635f30763805c1418a90c6b345eBob Wilson continue; 122328f872f8a1945635f30763805c1418a90c6b345eBob Wilson 122428f872f8a1945635f30763805c1418a90c6b345eBob Wilson // Disallow recursive calls. 122528f872f8a1945635f30763805c1418a90c6b345eBob Wilson if (&F == CS.getCalledFunction()) 122628f872f8a1945635f30763805c1418a90c6b345eBob Wilson return false; 122728f872f8a1945635f30763805c1418a90c6b345eBob Wilson 122828f872f8a1945635f30763805c1418a90c6b345eBob Wilson // Disallow calls which expose returns-twice to a function not previously 122928f872f8a1945635f30763805c1418a90c6b345eBob Wilson // attributed as such. 123028f872f8a1945635f30763805c1418a90c6b345eBob Wilson if (!ReturnsTwice && CS.isCall() && 123128f872f8a1945635f30763805c1418a90c6b345eBob Wilson cast<CallInst>(CS.getInstruction())->canReturnTwice()) 123228f872f8a1945635f30763805c1418a90c6b345eBob Wilson return false; 123328f872f8a1945635f30763805c1418a90c6b345eBob Wilson } 123428f872f8a1945635f30763805c1418a90c6b345eBob Wilson } 123528f872f8a1945635f30763805c1418a90c6b345eBob Wilson 123628f872f8a1945635f30763805c1418a90c6b345eBob Wilson return true; 123728f872f8a1945635f30763805c1418a90c6b345eBob Wilson} 1238