[llvm] r204389 - [Constant Hoisting] Extend coverage of the constant hoisting pass.
Eric Christopher
echristo at gmail.com
Thu Mar 20 13:29:32 PDT 2014
For the record, feel free to post-commit review it per normal, it
wasn't that kind of request. Just "hey, can you make it easier to do
post-commit review on" :)
-eric
On Thu, Mar 20, 2014 at 1:24 PM, Eric Christopher <echristo at gmail.com> wrote:
> Really appreciate it. Thanks Juergen! :)
>
> -eric
>
> On Thu, Mar 20, 2014 at 1:21 PM, Juergen Ributzka <juergen at apple.com> wrote:
>> Ok, I will try to break it up into sensible pieces.
>>
>> -Juergen
>>
>> On Mar 20, 2014, at 1:13 PM, Eric Christopher <echristo at gmail.com> wrote:
>>
>>> Actually, this patch is almost impossible to review otherwise. Would
>>> you mind doing this? :)
>>>
>>> -eric
>>>
>>> On Thu, Mar 20, 2014 at 1:12 PM, Eric Christopher <echristo at gmail.com> wrote:
>>>> Is there some reason this couldn't be split out into refactoring and
>>>> then adding new functionality?
>>>>
>>>> -eric
>>>>
>>>> On Thu, Mar 20, 2014 at 12:55 PM, Juergen Ributzka <juergen at apple.com> wrote:
>>>>> Author: ributzka
>>>>> Date: Thu Mar 20 14:55:52 2014
>>>>> New Revision: 204389
>>>>>
>>>>> URL: http://llvm.org/viewvc/llvm-project?rev=204389&view=rev
>>>>> Log:
>>>>> [Constant Hoisting] Extend coverage of the constant hoisting pass.
>>>>>
>>>>> This commit extends the coverage of the constant hoisting pass, adds additonal
>>>>> debug output and updates the function names according to the style guide.
>>>>>
>>>>> Related to <rdar://problem/16381500>
>>>>>
>>>>> Modified:
>>>>> llvm/trunk/include/llvm/Analysis/TargetTransformInfo.h
>>>>> llvm/trunk/lib/Analysis/TargetTransformInfo.cpp
>>>>> llvm/trunk/lib/Target/X86/X86TargetTransformInfo.cpp
>>>>> llvm/trunk/lib/Transforms/Scalar/ConstantHoisting.cpp
>>>>> llvm/trunk/test/CodeGen/X86/lsr-interesting-step.ll
>>>>> llvm/trunk/test/CodeGen/X86/negate-add-zero.ll
>>>>> llvm/trunk/test/Transforms/ConstantHoisting/X86/phi.ll
>>>>>
>>>>> Modified: llvm/trunk/include/llvm/Analysis/TargetTransformInfo.h
>>>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/TargetTransformInfo.h?rev=204389&r1=204388&r2=204389&view=diff
>>>>> ==============================================================================
>>>>> --- llvm/trunk/include/llvm/Analysis/TargetTransformInfo.h (original)
>>>>> +++ llvm/trunk/include/llvm/Analysis/TargetTransformInfo.h Thu Mar 20 14:55:52 2014
>>>>> @@ -297,10 +297,10 @@ public:
>>>>> /// \brief Return the expected cost of materialization for the given integer
>>>>> /// immediate of the specified type for a given instruction. The cost can be
>>>>> /// zero if the immediate can be folded into the specified instruction.
>>>>> - virtual unsigned getIntImmCost(unsigned Opcode, const APInt &Imm,
>>>>> - Type *Ty) const;
>>>>> - virtual unsigned getIntImmCost(Intrinsic::ID IID, const APInt &Imm,
>>>>> + virtual unsigned getIntImmCost(unsigned Opc, unsigned Idx, const APInt &Imm,
>>>>> Type *Ty) const;
>>>>> + virtual unsigned getIntImmCost(Intrinsic::ID IID, unsigned Idx,
>>>>> + const APInt &Imm, Type *Ty) const;
>>>>> /// @}
>>>>>
>>>>> /// \name Vector Target Information
>>>>>
>>>>> Modified: llvm/trunk/lib/Analysis/TargetTransformInfo.cpp
>>>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/TargetTransformInfo.cpp?rev=204389&r1=204388&r2=204389&view=diff
>>>>> ==============================================================================
>>>>> --- llvm/trunk/lib/Analysis/TargetTransformInfo.cpp (original)
>>>>> +++ llvm/trunk/lib/Analysis/TargetTransformInfo.cpp Thu Mar 20 14:55:52 2014
>>>>> @@ -148,14 +148,14 @@ unsigned TargetTransformInfo::getIntImmC
>>>>> return PrevTTI->getIntImmCost(Imm, Ty);
>>>>> }
>>>>>
>>>>> -unsigned TargetTransformInfo::getIntImmCost(unsigned Opcode, const APInt &Imm,
>>>>> - Type *Ty) const {
>>>>> - return PrevTTI->getIntImmCost(Opcode, Imm, Ty);
>>>>> +unsigned TargetTransformInfo::getIntImmCost(unsigned Opc, unsigned Idx,
>>>>> + const APInt &Imm, Type *Ty) const {
>>>>> + return PrevTTI->getIntImmCost(Opc, Idx, Imm, Ty);
>>>>> }
>>>>>
>>>>> -unsigned TargetTransformInfo::getIntImmCost(Intrinsic::ID IID, const APInt &Imm,
>>>>> - Type *Ty) const {
>>>>> - return PrevTTI->getIntImmCost(IID, Imm, Ty);
>>>>> +unsigned TargetTransformInfo::getIntImmCost(Intrinsic::ID IID, unsigned Idx,
>>>>> + const APInt &Imm, Type *Ty) const {
>>>>> + return PrevTTI->getIntImmCost(IID, Idx, Imm, Ty);
>>>>> }
>>>>>
>>>>> unsigned TargetTransformInfo::getNumberOfRegisters(bool Vector) const {
>>>>> @@ -539,12 +539,12 @@ struct NoTTI final : ImmutablePass, Targ
>>>>> return TCC_Basic;
>>>>> }
>>>>>
>>>>> - unsigned getIntImmCost(unsigned Opcode, const APInt &Imm,
>>>>> + unsigned getIntImmCost(unsigned Opcode, unsigned Idx, const APInt &Imm,
>>>>> Type *Ty) const override {
>>>>> return TCC_Free;
>>>>> }
>>>>>
>>>>> - unsigned getIntImmCost(Intrinsic::ID IID, const APInt &Imm,
>>>>> + unsigned getIntImmCost(Intrinsic::ID IID, unsigned Idx, const APInt &Imm,
>>>>> Type *Ty) const override {
>>>>> return TCC_Free;
>>>>> }
>>>>>
>>>>> Modified: llvm/trunk/lib/Target/X86/X86TargetTransformInfo.cpp
>>>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86TargetTransformInfo.cpp?rev=204389&r1=204388&r2=204389&view=diff
>>>>> ==============================================================================
>>>>> --- llvm/trunk/lib/Target/X86/X86TargetTransformInfo.cpp (original)
>>>>> +++ llvm/trunk/lib/Target/X86/X86TargetTransformInfo.cpp Thu Mar 20 14:55:52 2014
>>>>> @@ -103,9 +103,9 @@ public:
>>>>>
>>>>> unsigned getIntImmCost(const APInt &Imm, Type *Ty) const override;
>>>>>
>>>>> - unsigned getIntImmCost(unsigned Opcode, const APInt &Imm,
>>>>> + unsigned getIntImmCost(unsigned Opcode, unsigned Idx, const APInt &Imm,
>>>>> Type *Ty) const override;
>>>>> - unsigned getIntImmCost(Intrinsic::ID IID, const APInt &Imm,
>>>>> + unsigned getIntImmCost(Intrinsic::ID IID, unsigned Idx, const APInt &Imm,
>>>>> Type *Ty) const override;
>>>>>
>>>>> /// @}
>>>>> @@ -776,6 +776,9 @@ unsigned X86TTI::getIntImmCost(const API
>>>>> if (BitSize == 0)
>>>>> return ~0U;
>>>>>
>>>>> + if (Imm == 0)
>>>>> + return TCC_Free;
>>>>> +
>>>>> if (Imm.getBitWidth() <= 64 &&
>>>>> (isInt<32>(Imm.getSExtValue()) || isUInt<32>(Imm.getZExtValue())))
>>>>> return TCC_Basic;
>>>>> @@ -783,7 +786,7 @@ unsigned X86TTI::getIntImmCost(const API
>>>>> return 2 * TCC_Basic;
>>>>> }
>>>>>
>>>>> -unsigned X86TTI::getIntImmCost(unsigned Opcode, const APInt &Imm,
>>>>> +unsigned X86TTI::getIntImmCost(unsigned Opcode, unsigned Idx, const APInt &Imm,
>>>>> Type *Ty) const {
>>>>> assert(Ty->isIntegerTy());
>>>>>
>>>>> @@ -791,7 +794,15 @@ unsigned X86TTI::getIntImmCost(unsigned
>>>>> if (BitSize == 0)
>>>>> return ~0U;
>>>>>
>>>>> + unsigned ImmIdx = ~0U;
>>>>> switch (Opcode) {
>>>>> + default: return TCC_Free;
>>>>> + case Instruction::GetElementPtr:
>>>>> + if (Idx != 0)
>>>>> + return TCC_Free;
>>>>> + case Instruction::Store:
>>>>> + ImmIdx = 0;
>>>>> + break;
>>>>> case Instruction::Add:
>>>>> case Instruction::Sub:
>>>>> case Instruction::Mul:
>>>>> @@ -806,28 +817,31 @@ unsigned X86TTI::getIntImmCost(unsigned
>>>>> case Instruction::Or:
>>>>> case Instruction::Xor:
>>>>> case Instruction::ICmp:
>>>>> - if (Imm.getBitWidth() <= 64 && isInt<32>(Imm.getSExtValue()))
>>>>> - return TCC_Free;
>>>>> - else
>>>>> - return X86TTI::getIntImmCost(Imm, Ty);
>>>>> + ImmIdx = 1;
>>>>> + break;
>>>>> case Instruction::Trunc:
>>>>> case Instruction::ZExt:
>>>>> case Instruction::SExt:
>>>>> case Instruction::IntToPtr:
>>>>> case Instruction::PtrToInt:
>>>>> case Instruction::BitCast:
>>>>> + case Instruction::PHI:
>>>>> case Instruction::Call:
>>>>> case Instruction::Select:
>>>>> case Instruction::Ret:
>>>>> case Instruction::Load:
>>>>> - case Instruction::Store:
>>>>> - return X86TTI::getIntImmCost(Imm, Ty);
>>>>> + break;
>>>>> }
>>>>> - return TargetTransformInfo::getIntImmCost(Opcode, Imm, Ty);
>>>>> +
>>>>> + if ((Idx == ImmIdx) &&
>>>>> + Imm.getBitWidth() <= 64 && isInt<32>(Imm.getSExtValue()))
>>>>> + return TCC_Free;
>>>>> +
>>>>> + return X86TTI::getIntImmCost(Imm, Ty);
>>>>> }
>>>>>
>>>>> -unsigned X86TTI::getIntImmCost(Intrinsic::ID IID, const APInt &Imm,
>>>>> - Type *Ty) const {
>>>>> +unsigned X86TTI::getIntImmCost(Intrinsic::ID IID, unsigned Idx,
>>>>> + const APInt &Imm, Type *Ty) const {
>>>>> assert(Ty->isIntegerTy());
>>>>>
>>>>> unsigned BitSize = Ty->getPrimitiveSizeInBits();
>>>>> @@ -835,21 +849,24 @@ unsigned X86TTI::getIntImmCost(Intrinsic
>>>>> return ~0U;
>>>>>
>>>>> switch (IID) {
>>>>> - default: return TargetTransformInfo::getIntImmCost(IID, Imm, Ty);
>>>>> + default: return TCC_Free;
>>>>> case Intrinsic::sadd_with_overflow:
>>>>> case Intrinsic::uadd_with_overflow:
>>>>> case Intrinsic::ssub_with_overflow:
>>>>> case Intrinsic::usub_with_overflow:
>>>>> case Intrinsic::smul_with_overflow:
>>>>> case Intrinsic::umul_with_overflow:
>>>>> - if (Imm.getBitWidth() <= 64 && isInt<32>(Imm.getSExtValue()))
>>>>> + if ((Idx == 1) && Imm.getBitWidth() <= 64 && isInt<32>(Imm.getSExtValue()))
>>>>> return TCC_Free;
>>>>> else
>>>>> return X86TTI::getIntImmCost(Imm, Ty);
>>>>> case Intrinsic::experimental_stackmap:
>>>>> + if (Idx < 2)
>>>>> + return TCC_Free;
>>>>> case Intrinsic::experimental_patchpoint_void:
>>>>> case Intrinsic::experimental_patchpoint_i64:
>>>>> - if (Imm.getBitWidth() <= 64 && isInt<64>(Imm.getSExtValue()))
>>>>> + if ((Idx < 4 ) ||
>>>>> + (Imm.getBitWidth() <= 64 && isInt<64>(Imm.getSExtValue())))
>>>>> return TCC_Free;
>>>>> else
>>>>> return X86TTI::getIntImmCost(Imm, Ty);
>>>>>
>>>>> Modified: llvm/trunk/lib/Transforms/Scalar/ConstantHoisting.cpp
>>>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/ConstantHoisting.cpp?rev=204389&r1=204388&r2=204389&view=diff
>>>>> ==============================================================================
>>>>> --- llvm/trunk/lib/Transforms/Scalar/ConstantHoisting.cpp (original)
>>>>> +++ llvm/trunk/lib/Transforms/Scalar/ConstantHoisting.cpp Thu Mar 20 14:55:52 2014
>>>>> @@ -35,15 +35,14 @@
>>>>>
>>>>> #define DEBUG_TYPE "consthoist"
>>>>> #include "llvm/Transforms/Scalar.h"
>>>>> -#include "llvm/ADT/MapVector.h"
>>>>> #include "llvm/ADT/SmallSet.h"
>>>>> +#include "llvm/ADT/SmallVector.h"
>>>>> #include "llvm/ADT/Statistic.h"
>>>>> #include "llvm/Analysis/TargetTransformInfo.h"
>>>>> #include "llvm/IR/Constants.h"
>>>>> #include "llvm/IR/Dominators.h"
>>>>> #include "llvm/IR/IntrinsicInst.h"
>>>>> #include "llvm/Pass.h"
>>>>> -#include "llvm/Support/CommandLine.h"
>>>>> #include "llvm/Support/Debug.h"
>>>>>
>>>>> using namespace llvm;
>>>>> @@ -51,42 +50,80 @@ using namespace llvm;
>>>>> STATISTIC(NumConstantsHoisted, "Number of constants hoisted");
>>>>> STATISTIC(NumConstantsRebased, "Number of constants rebased");
>>>>>
>>>>> -
>>>>> namespace {
>>>>> -typedef SmallVector<User *, 4> ConstantUseListType;
>>>>> +struct ConstantUser;
>>>>> +struct RebasedConstantInfo;
>>>>> +
>>>>> +typedef SmallVector<ConstantUser, 8> ConstantUseListType;
>>>>> +typedef SmallVector<RebasedConstantInfo, 4> RebasedConstantListType;
>>>>> +
>>>>> +/// \brief Keeps track of the user of a constant and the operand index where the
>>>>> +/// constant is used.
>>>>> +struct ConstantUser {
>>>>> + Instruction *Inst;
>>>>> + unsigned OpndIdx;
>>>>> +
>>>>> + ConstantUser(Instruction *Inst, unsigned Idx) : Inst(Inst), OpndIdx(Idx) { }
>>>>> +};
>>>>> +
>>>>> +/// \brief Keeps track of a constant candidate and its usees.
>>>>> struct ConstantCandidate {
>>>>> + ConstantUseListType Uses;
>>>>> + ConstantInt *ConstInt;
>>>>> unsigned CumulativeCost;
>>>>> +
>>>>> + ConstantCandidate(ConstantInt *ConstInt)
>>>>> + : ConstInt(ConstInt), CumulativeCost(0) { }
>>>>> +
>>>>> + /// \brief Add the user to the use list and update the cost.
>>>>> + void addUser(Instruction *Inst, unsigned Idx, unsigned Cost) {
>>>>> + CumulativeCost += Cost;
>>>>> + Uses.push_back(ConstantUser(Inst, Idx));
>>>>> + }
>>>>> +};
>>>>> +
>>>>> +/// \brief This represents a constant that has been rebased with respect to a
>>>>> +/// base constant. The difference to the base constant is recorded in Offset.
>>>>> +struct RebasedConstantInfo {
>>>>> ConstantUseListType Uses;
>>>>> + Constant *Offset;
>>>>> + mutable BasicBlock *IDom;
>>>>> +
>>>>> + RebasedConstantInfo(ConstantUseListType &&Uses, Constant *Offset)
>>>>> + : Uses(Uses), Offset(Offset), IDom(nullptr) { }
>>>>> };
>>>>>
>>>>> +/// \brief A base constant and all its rebased constants.
>>>>> struct ConstantInfo {
>>>>> ConstantInt *BaseConstant;
>>>>> - struct RebasedConstantInfo {
>>>>> - ConstantInt *OriginalConstant;
>>>>> - Constant *Offset;
>>>>> - ConstantUseListType Uses;
>>>>> - };
>>>>> - typedef SmallVector<RebasedConstantInfo, 4> RebasedConstantListType;
>>>>> RebasedConstantListType RebasedConstants;
>>>>> };
>>>>>
>>>>> +/// \brief The constant hoisting pass.
>>>>> class ConstantHoisting : public FunctionPass {
>>>>> + typedef DenseMap<ConstantInt *, unsigned> ConstCandMapType;
>>>>> + typedef std::vector<ConstantCandidate> ConstCandVecType;
>>>>> +
>>>>> const TargetTransformInfo *TTI;
>>>>> DominatorTree *DT;
>>>>> + BasicBlock *Entry;
>>>>> +
>>>>> + /// Keeps track of constant candidates found in the function.
>>>>> + ConstCandMapType ConstCandMap;
>>>>> + ConstCandVecType ConstCandVec;
>>>>>
>>>>> - /// Keeps track of expensive constants found in the function.
>>>>> - typedef MapVector<ConstantInt *, ConstantCandidate> ConstantMapType;
>>>>> - ConstantMapType ConstantMap;
>>>>> + /// Keep track of cast instructions we already cloned.
>>>>> + SmallDenseMap<Instruction *, Instruction *> ClonedCastMap;
>>>>>
>>>>> /// These are the final constants we decided to hoist.
>>>>> - SmallVector<ConstantInfo, 4> Constants;
>>>>> + SmallVector<ConstantInfo, 8> ConstantVec;
>>>>> public:
>>>>> static char ID; // Pass identification, replacement for typeid
>>>>> - ConstantHoisting() : FunctionPass(ID), TTI(0) {
>>>>> + ConstantHoisting() : FunctionPass(ID), TTI(0), DT(0), Entry(0) {
>>>>> initializeConstantHoistingPass(*PassRegistry::getPassRegistry());
>>>>> }
>>>>>
>>>>> - bool runOnFunction(Function &F) override;
>>>>> + bool runOnFunction(Function &Fn) override;
>>>>>
>>>>> const char *getPassName() const override { return "Constant Hoisting"; }
>>>>>
>>>>> @@ -97,19 +134,49 @@ public:
>>>>> }
>>>>>
>>>>> private:
>>>>> - void CollectConstant(User *U, unsigned Opcode, Intrinsic::ID IID,
>>>>> - ConstantInt *C);
>>>>> - void CollectConstants(Instruction *I);
>>>>> - void CollectConstants(Function &F);
>>>>> - void FindAndMakeBaseConstant(ConstantMapType::iterator S,
>>>>> - ConstantMapType::iterator E);
>>>>> - void FindBaseConstants();
>>>>> - Instruction *FindConstantInsertionPoint(Function &F,
>>>>> - const ConstantInfo &CI) const;
>>>>> - void EmitBaseConstants(Function &F, User *U, Instruction *Base,
>>>>> - Constant *Offset, ConstantInt *OriginalConstant);
>>>>> - bool EmitBaseConstants(Function &F);
>>>>> - bool OptimizeConstants(Function &F);
>>>>> + /// \brief Initialize the pass.
>>>>> + void setup(Function &Fn) {
>>>>> + DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
>>>>> + TTI = &getAnalysis<TargetTransformInfo>();
>>>>> + Entry = &Fn.getEntryBlock();
>>>>> + }
>>>>> +
>>>>> + /// \brief Cleanup.
>>>>> + void cleanup() {
>>>>> + ConstantVec.clear();
>>>>> + ClonedCastMap.clear();
>>>>> + ConstCandVec.clear();
>>>>> + ConstCandMap.clear();
>>>>> +
>>>>> + TTI = nullptr;
>>>>> + DT = nullptr;
>>>>> + Entry = nullptr;
>>>>> + }
>>>>> +
>>>>> + /// \brief Find the common dominator of all uses and cache the result for
>>>>> + /// future lookup.
>>>>> + BasicBlock *getIDom(const RebasedConstantInfo &RCI) const {
>>>>> + if (RCI.IDom)
>>>>> + return RCI.IDom;
>>>>> + RCI.IDom = findIDomOfAllUses(RCI.Uses);
>>>>> + assert(RCI.IDom && "Invalid IDom.");
>>>>> + return RCI.IDom;
>>>>> + }
>>>>> +
>>>>> + BasicBlock *findIDomOfAllUses(const ConstantUseListType &Uses) const;
>>>>> + Instruction *findMatInsertPt(Instruction *I, unsigned Idx = ~0U) const;
>>>>> + Instruction *findConstantInsertionPoint(const ConstantInfo &CI) const;
>>>>> + void collectConstantCandidates(Instruction *I, unsigned Idx, ConstantInt *C);
>>>>> + void collectConstantCandidates(Instruction *I);
>>>>> + void collectConstantCandidates(Function &Fn);
>>>>> + void findAndMakeBaseConstant(ConstCandVecType::iterator S,
>>>>> + ConstCandVecType::iterator E);
>>>>> + void findBaseConstants();
>>>>> + void emitBaseConstants(Instruction *Base, Constant *Offset,
>>>>> + const ConstantUser &CU);
>>>>> + bool emitBaseConstants();
>>>>> + void deleteDeadCastInst() const;
>>>>> + bool optimizeConstants(Function &F);
>>>>> };
>>>>> }
>>>>>
>>>>> @@ -126,297 +193,352 @@ FunctionPass *llvm::createConstantHoisti
>>>>> }
>>>>>
>>>>> /// \brief Perform the constant hoisting optimization for the given function.
>>>>> -bool ConstantHoisting::runOnFunction(Function &F) {
>>>>> - DEBUG(dbgs() << "********** Constant Hoisting **********\n");
>>>>> - DEBUG(dbgs() << "********** Function: " << F.getName() << '\n');
>>>>> +bool ConstantHoisting::runOnFunction(Function &Fn) {
>>>>> + DEBUG(dbgs() << "********** Begin Constant Hoisting **********\n");
>>>>> + DEBUG(dbgs() << "********** Function: " << Fn.getName() << '\n');
>>>>>
>>>>> - DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
>>>>> - TTI = &getAnalysis<TargetTransformInfo>();
>>>>> + setup(Fn);
>>>>>
>>>>> - return OptimizeConstants(F);
>>>>> + bool MadeChange = optimizeConstants(Fn);
>>>>> +
>>>>> + if (MadeChange) {
>>>>> + DEBUG(dbgs() << "********** Function after Constant Hoisting: "
>>>>> + << Fn.getName() << '\n');
>>>>> + DEBUG(dbgs() << Fn);
>>>>> + }
>>>>> + DEBUG(dbgs() << "********** End Constant Hoisting **********\n");
>>>>> +
>>>>> + cleanup();
>>>>> +
>>>>> + return MadeChange;
>>>>> }
>>>>>
>>>>> -void ConstantHoisting::CollectConstant(User * U, unsigned Opcode,
>>>>> - Intrinsic::ID IID, ConstantInt *C) {
>>>>> +/// \brief Find nearest common dominator of all uses.
>>>>> +/// FIXME: Replace this with NearestCommonDominator once it is in common code.
>>>>> +BasicBlock *
>>>>> +ConstantHoisting::findIDomOfAllUses(const ConstantUseListType &Uses) const {
>>>>> + // Collect all basic blocks.
>>>>> + SmallPtrSet<BasicBlock *, 8> BBs;
>>>>> + for (auto const &U : Uses)
>>>>> + BBs.insert(findMatInsertPt(U.Inst, U.OpndIdx)->getParent());
>>>>> +
>>>>> + if (BBs.count(Entry))
>>>>> + return Entry;
>>>>> +
>>>>> + while (BBs.size() >= 2) {
>>>>> + BasicBlock *BB, *BB1, *BB2;
>>>>> + BB1 = *BBs.begin();
>>>>> + BB2 = *std::next(BBs.begin());
>>>>> + BB = DT->findNearestCommonDominator(BB1, BB2);
>>>>> + if (BB == Entry)
>>>>> + return Entry;
>>>>> + BBs.erase(BB1);
>>>>> + BBs.erase(BB2);
>>>>> + BBs.insert(BB);
>>>>> + }
>>>>> + assert((BBs.size() == 1) && "Expected only one element.");
>>>>> + return *BBs.begin();
>>>>> +}
>>>>> +
>>>>> +/// \brief Find the constant materialization insertion point.
>>>>> +Instruction *ConstantHoisting::findMatInsertPt(Instruction *Inst,
>>>>> + unsigned Idx) const {
>>>>> + // The simple and common case.
>>>>> + if (!isa<PHINode>(Inst) && !isa<LandingPadInst>(Inst))
>>>>> + return Inst;
>>>>> +
>>>>> + // We can't insert directly before a phi node or landing pad. Insert before
>>>>> + // the terminator of the incoming or dominating block.
>>>>> + assert(Entry != Inst->getParent() && "PHI or landing pad in entry block!");
>>>>> + if (Idx != ~0U && isa<PHINode>(Inst))
>>>>> + return cast<PHINode>(Inst)->getIncomingBlock(Idx)->getTerminator();
>>>>> +
>>>>> + BasicBlock *IDom = DT->getNode(Inst->getParent())->getIDom()->getBlock();
>>>>> + return IDom->getTerminator();
>>>>> +}
>>>>> +
>>>>> +/// \brief Find an insertion point that dominates all uses.
>>>>> +Instruction *ConstantHoisting::
>>>>> +findConstantInsertionPoint(const ConstantInfo &ConstInfo) const {
>>>>> + assert(!ConstInfo.RebasedConstants.empty() && "Invalid constant info entry.");
>>>>> + // Collect all IDoms.
>>>>> + SmallPtrSet<BasicBlock *, 8> BBs;
>>>>> + for (auto const &RCI : ConstInfo.RebasedConstants)
>>>>> + BBs.insert(getIDom(RCI));
>>>>> +
>>>>> + assert(!BBs.empty() && "No dominators!?");
>>>>> +
>>>>> + if (BBs.count(Entry))
>>>>> + return &Entry->front();
>>>>> +
>>>>> + while (BBs.size() >= 2) {
>>>>> + BasicBlock *BB, *BB1, *BB2;
>>>>> + BB1 = *BBs.begin();
>>>>> + BB2 = *std::next(BBs.begin());
>>>>> + BB = DT->findNearestCommonDominator(BB1, BB2);
>>>>> + if (BB == Entry)
>>>>> + return &Entry->front();
>>>>> + BBs.erase(BB1);
>>>>> + BBs.erase(BB2);
>>>>> + BBs.insert(BB);
>>>>> + }
>>>>> + assert((BBs.size() == 1) && "Expected only one element.");
>>>>> + Instruction &FirstInst = (*BBs.begin())->front();
>>>>> + return findMatInsertPt(&FirstInst);
>>>>> +}
>>>>> +
>>>>> +
>>>>> +/// \brief Record constant integer ConstInt for instruction Inst at operand
>>>>> +/// index Idx.
>>>>> +///
>>>>> +/// The operand at index Idx is not necessarily the constant inetger itself. It
>>>>> +/// could also be a cast instruction or a constant expression that uses the
>>>>> +// constant integer.
>>>>> +void ConstantHoisting::collectConstantCandidates(Instruction *Inst,
>>>>> + unsigned Idx,
>>>>> + ConstantInt *ConstInt) {
>>>>> unsigned Cost;
>>>>> - if (Opcode)
>>>>> - Cost = TTI->getIntImmCost(Opcode, C->getValue(), C->getType());
>>>>> + // Ask the target about the cost of materializing the constant for the given
>>>>> + // instruction and operand index.
>>>>> + if (auto IntrInst = dyn_cast<IntrinsicInst>(Inst))
>>>>> + Cost = TTI->getIntImmCost(IntrInst->getIntrinsicID(), Idx,
>>>>> + ConstInt->getValue(), ConstInt->getType());
>>>>> else
>>>>> - Cost = TTI->getIntImmCost(IID, C->getValue(), C->getType());
>>>>> + Cost = TTI->getIntImmCost(Inst->getOpcode(), Idx, ConstInt->getValue(),
>>>>> + ConstInt->getType());
>>>>>
>>>>> + // Ignore cheap integer constants.
>>>>> if (Cost > TargetTransformInfo::TCC_Basic) {
>>>>> - ConstantCandidate &CC = ConstantMap[C];
>>>>> - CC.CumulativeCost += Cost;
>>>>> - CC.Uses.push_back(U);
>>>>> - DEBUG(dbgs() << "Collect constant " << *C << " with cost " << Cost
>>>>> - << " from " << *U << '\n');
>>>>> + ConstCandMapType::iterator Itr;
>>>>> + bool Inserted;
>>>>> + std::tie(Itr, Inserted) = ConstCandMap.insert(std::make_pair(ConstInt, 0));
>>>>> + if (Inserted) {
>>>>> + ConstCandVec.push_back(ConstantCandidate(ConstInt));
>>>>> + Itr->second = ConstCandVec.size() - 1;
>>>>> + }
>>>>> + ConstCandVec[Itr->second].addUser(Inst, Idx, Cost);
>>>>> + DEBUG(if (auto ConstInt = dyn_cast<ConstantInt>(Inst->getOperand(Idx)))
>>>>> + dbgs() << "Collect constant " << *ConstInt << " from " << *Inst
>>>>> + << " with cost " << Cost << '\n';
>>>>> + else
>>>>> + dbgs() << "Collect constant " << *ConstInt << " indirectly from "
>>>>> + << *Inst << " via " << *Inst->getOperand(Idx) << " with cost "
>>>>> + << Cost << '\n';
>>>>> + );
>>>>> }
>>>>> }
>>>>>
>>>>> -/// \brief Scan the instruction or constant expression for expensive integer
>>>>> -/// constants and record them in the constant map.
>>>>> -void ConstantHoisting::CollectConstants(Instruction *I) {
>>>>> - unsigned Opcode = 0;
>>>>> - Intrinsic::ID IID = Intrinsic::not_intrinsic;
>>>>> - if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I))
>>>>> - IID = II->getIntrinsicID();
>>>>> - else
>>>>> - Opcode = I->getOpcode();
>>>>> +/// \brief Scan the instruction for expensive integer constants and record them
>>>>> +/// in the constant candidate vector.
>>>>> +void ConstantHoisting::collectConstantCandidates(Instruction *Inst) {
>>>>> + // Skip all cast instructions. They are visited indirectly later on.
>>>>> + if (Inst->isCast())
>>>>> + return;
>>>>> +
>>>>> + // Can't handle inline asm. Skip it.
>>>>> + if (auto Call = dyn_cast<CallInst>(Inst))
>>>>> + if (isa<InlineAsm>(Call->getCalledValue()))
>>>>> + return;
>>>>>
>>>>> // Scan all operands.
>>>>> - for (User::op_iterator O = I->op_begin(), E = I->op_end(); O != E; ++O) {
>>>>> - if (ConstantInt *C = dyn_cast<ConstantInt>(O)) {
>>>>> - CollectConstant(I, Opcode, IID, C);
>>>>> + for (unsigned Idx = 0, E = Inst->getNumOperands(); Idx != E; ++Idx) {
>>>>> + Value *Opnd = Inst->getOperand(Idx);
>>>>> +
>>>>> + // Vist constant integers.
>>>>> + if (auto ConstInt = dyn_cast<ConstantInt>(Opnd)) {
>>>>> + collectConstantCandidates(Inst, Idx, ConstInt);
>>>>> continue;
>>>>> }
>>>>> - if (ConstantExpr *CE = dyn_cast<ConstantExpr>(O)) {
>>>>> - // We only handle constant cast expressions.
>>>>> - if (!CE->isCast())
>>>>> +
>>>>> + // Visit cast instructions that have constant integers.
>>>>> + if (auto CastInst = dyn_cast<Instruction>(Opnd)) {
>>>>> + // Only visit cast instructions, which have been skipped. All other
>>>>> + // instructions should have already been visited.
>>>>> + if (!CastInst->isCast())
>>>>> continue;
>>>>>
>>>>> - if (ConstantInt *C = dyn_cast<ConstantInt>(CE->getOperand(0))) {
>>>>> - // Ignore the cast expression and use the opcode of the instruction.
>>>>> - CollectConstant(CE, Opcode, IID, C);
>>>>> + if (auto *ConstInt = dyn_cast<ConstantInt>(CastInst->getOperand(0))) {
>>>>> + // Pretend the constant is directly used by the instruction and ignore
>>>>> + // the cast instruction.
>>>>> + collectConstantCandidates(Inst, Idx, ConstInt);
>>>>> continue;
>>>>> }
>>>>> }
>>>>> - }
>>>>> +
>>>>> + // Visit constant expressions that have constant integers.
>>>>> + if (auto ConstExpr = dyn_cast<ConstantExpr>(Opnd)) {
>>>>> + // Only visit constant cast expressions.
>>>>> + if (!ConstExpr->isCast())
>>>>> + continue;
>>>>> +
>>>>> + if (auto ConstInt = dyn_cast<ConstantInt>(ConstExpr->getOperand(0))) {
>>>>> + // Pretend the constant is directly used by the instruction and ignore
>>>>> + // the constant expression.
>>>>> + collectConstantCandidates(Inst, Idx, ConstInt);
>>>>> + continue;
>>>>> + }
>>>>> + }
>>>>> + } // end of for all operands
>>>>> }
>>>>>
>>>>> /// \brief Collect all integer constants in the function that cannot be folded
>>>>> /// into an instruction itself.
>>>>> -void ConstantHoisting::CollectConstants(Function &F) {
>>>>> - for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
>>>>> - for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
>>>>> - CollectConstants(I);
>>>>> +void ConstantHoisting::collectConstantCandidates(Function &Fn) {
>>>>> + for (Function::iterator BB : Fn)
>>>>> + for (BasicBlock::iterator I : *BB)
>>>>> + collectConstantCandidates(I);
>>>>> }
>>>>>
>>>>> /// \brief Find the base constant within the given range and rebase all other
>>>>> /// constants with respect to the base constant.
>>>>> -void ConstantHoisting::FindAndMakeBaseConstant(ConstantMapType::iterator S,
>>>>> - ConstantMapType::iterator E) {
>>>>> - ConstantMapType::iterator MaxCostItr = S;
>>>>> +void ConstantHoisting::findAndMakeBaseConstant(ConstCandVecType::iterator S,
>>>>> + ConstCandVecType::iterator E) {
>>>>> + auto MaxCostItr = S;
>>>>> unsigned NumUses = 0;
>>>>> // Use the constant that has the maximum cost as base constant.
>>>>> - for (ConstantMapType::iterator I = S; I != E; ++I) {
>>>>> - NumUses += I->second.Uses.size();
>>>>> - if (I->second.CumulativeCost > MaxCostItr->second.CumulativeCost)
>>>>> - MaxCostItr = I;
>>>>> + for (auto ConstCand = S; ConstCand != E; ++ConstCand) {
>>>>> + NumUses += ConstCand->Uses.size();
>>>>> + if (ConstCand->CumulativeCost > MaxCostItr->CumulativeCost)
>>>>> + MaxCostItr = ConstCand;
>>>>> }
>>>>>
>>>>> // Don't hoist constants that have only one use.
>>>>> if (NumUses <= 1)
>>>>> return;
>>>>>
>>>>> - ConstantInfo CI;
>>>>> - CI.BaseConstant = MaxCostItr->first;
>>>>> - Type *Ty = CI.BaseConstant->getType();
>>>>> + ConstantInfo ConstInfo;
>>>>> + ConstInfo.BaseConstant = MaxCostItr->ConstInt;
>>>>> + Type *Ty = ConstInfo.BaseConstant->getType();
>>>>> +
>>>>> // Rebase the constants with respect to the base constant.
>>>>> - for (ConstantMapType::iterator I = S; I != E; ++I) {
>>>>> - APInt Diff = I->first->getValue() - CI.BaseConstant->getValue();
>>>>> - ConstantInfo::RebasedConstantInfo RCI;
>>>>> - RCI.OriginalConstant = I->first;
>>>>> - RCI.Offset = ConstantInt::get(Ty, Diff);
>>>>> - RCI.Uses = std::move(I->second.Uses);
>>>>> - CI.RebasedConstants.push_back(RCI);
>>>>> - }
>>>>> - Constants.push_back(CI);
>>>>> -}
>>>>> -
>>>>> -/// \brief Finds and combines constants that can be easily rematerialized with
>>>>> -/// an add from a common base constant.
>>>>> -void ConstantHoisting::FindBaseConstants() {
>>>>> - // Sort the constants by value and type. This invalidates the mapping.
>>>>> - std::sort(ConstantMap.begin(), ConstantMap.end(),
>>>>> - [](const std::pair<ConstantInt *, ConstantCandidate> &LHS,
>>>>> - const std::pair<ConstantInt *, ConstantCandidate> &RHS) {
>>>>> - if (LHS.first->getType() != RHS.first->getType())
>>>>> - return LHS.first->getType()->getBitWidth() <
>>>>> - RHS.first->getType()->getBitWidth();
>>>>> - return LHS.first->getValue().ult(RHS.first->getValue());
>>>>> - });
>>>>> -
>>>>> - // Simple linear scan through the sorted constant map for viable merge
>>>>> - // candidates.
>>>>> - ConstantMapType::iterator MinValItr = ConstantMap.begin();
>>>>> - for (ConstantMapType::iterator I = std::next(ConstantMap.begin()),
>>>>> - E = ConstantMap.end(); I != E; ++I) {
>>>>> - if (MinValItr->first->getType() == I->first->getType()) {
>>>>> + for (auto ConstCand = S; ConstCand != E; ++ConstCand) {
>>>>> + APInt Diff = ConstCand->ConstInt->getValue() -
>>>>> + ConstInfo.BaseConstant->getValue();
>>>>> + Constant *Offset = Diff == 0 ? nullptr : ConstantInt::get(Ty, Diff);
>>>>> + ConstInfo.RebasedConstants.push_back(
>>>>> + RebasedConstantInfo(std::move(ConstCand->Uses), Offset));
>>>>> + }
>>>>> + ConstantVec.push_back(ConstInfo);
>>>>> +}
>>>>> +
>>>>> +/// \brief Finds and combines constant candidates that can be easily
>>>>> +/// rematerialized with an add from a common base constant.
>>>>> +void ConstantHoisting::findBaseConstants() {
>>>>> + // Sort the constants by value and type. This invalidates the mapping!
>>>>> + std::sort(ConstCandVec.begin(), ConstCandVec.end(),
>>>>> + [](const ConstantCandidate &LHS, const ConstantCandidate &RHS) {
>>>>> + if (LHS.ConstInt->getType() != RHS.ConstInt->getType())
>>>>> + return LHS.ConstInt->getType()->getBitWidth() <
>>>>> + RHS.ConstInt->getType()->getBitWidth();
>>>>> + return LHS.ConstInt->getValue().ult(RHS.ConstInt->getValue());
>>>>> + });
>>>>> +
>>>>> + // Simple linear scan through the sorted constant candidate vector for viable
>>>>> + // merge candidates.
>>>>> + auto MinValItr = ConstCandVec.begin();
>>>>> + for (auto CC = std::next(ConstCandVec.begin()), E = ConstCandVec.end();
>>>>> + CC != E; ++CC) {
>>>>> + if (MinValItr->ConstInt->getType() == CC->ConstInt->getType()) {
>>>>> // Check if the constant is in range of an add with immediate.
>>>>> - APInt Diff = I->first->getValue() - MinValItr->first->getValue();
>>>>> + APInt Diff = CC->ConstInt->getValue() - MinValItr->ConstInt->getValue();
>>>>> if ((Diff.getBitWidth() <= 64) &&
>>>>> TTI->isLegalAddImmediate(Diff.getSExtValue()))
>>>>> continue;
>>>>> }
>>>>> // We either have now a different constant type or the constant is not in
>>>>> // range of an add with immediate anymore.
>>>>> - FindAndMakeBaseConstant(MinValItr, I);
>>>>> + findAndMakeBaseConstant(MinValItr, CC);
>>>>> // Start a new base constant search.
>>>>> - MinValItr = I;
>>>>> + MinValItr = CC;
>>>>> }
>>>>> // Finalize the last base constant search.
>>>>> - FindAndMakeBaseConstant(MinValItr, ConstantMap.end());
>>>>> -}
>>>>> -
>>>>> -/// \brief Records the basic block of the instruction or all basic blocks of the
>>>>> -/// users of the constant expression.
>>>>> -static void CollectBasicBlocks(SmallPtrSet<BasicBlock *, 4> &BBs, Function &F,
>>>>> - User *U) {
>>>>> - if (Instruction *I = dyn_cast<Instruction>(U))
>>>>> - BBs.insert(I->getParent());
>>>>> - else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(U))
>>>>> - // Find all users of this constant expression.
>>>>> - for (User *UU : CE->users())
>>>>> - // Only record users that are instructions. We don't want to go down a
>>>>> - // nested constant expression chain. Also check if the instruction is even
>>>>> - // in the current function.
>>>>> - if (Instruction *I = dyn_cast<Instruction>(UU))
>>>>> - if(I->getParent()->getParent() == &F)
>>>>> - BBs.insert(I->getParent());
>>>>> -}
>>>>> -
>>>>> -/// \brief Find the instruction we should insert the constant materialization
>>>>> -/// before.
>>>>> -static Instruction *getMatInsertPt(Instruction *I, const DominatorTree *DT) {
>>>>> - if (!isa<PHINode>(I) && !isa<LandingPadInst>(I)) // Simple case.
>>>>> - return I;
>>>>> -
>>>>> - // We can't insert directly before a phi node or landing pad. Insert before
>>>>> - // the terminator of the dominating block.
>>>>> - assert(&I->getParent()->getParent()->getEntryBlock() != I->getParent() &&
>>>>> - "PHI or landing pad in entry block!");
>>>>> - BasicBlock *IDom = DT->getNode(I->getParent())->getIDom()->getBlock();
>>>>> - return IDom->getTerminator();
>>>>> -}
>>>>> -
>>>>> -/// \brief Find an insertion point that dominates all uses.
>>>>> -Instruction *ConstantHoisting::
>>>>> -FindConstantInsertionPoint(Function &F, const ConstantInfo &CI) const {
>>>>> - BasicBlock *Entry = &F.getEntryBlock();
>>>>> -
>>>>> - // Collect all basic blocks.
>>>>> - SmallPtrSet<BasicBlock *, 4> BBs;
>>>>> - ConstantInfo::RebasedConstantListType::const_iterator RCI, RCE;
>>>>> - for (RCI = CI.RebasedConstants.begin(), RCE = CI.RebasedConstants.end();
>>>>> - RCI != RCE; ++RCI)
>>>>> - for (SmallVectorImpl<User *>::const_iterator U = RCI->Uses.begin(),
>>>>> - E = RCI->Uses.end(); U != E; ++U)
>>>>> - CollectBasicBlocks(BBs, F, *U);
>>>>> -
>>>>> - if (BBs.count(Entry))
>>>>> - return getMatInsertPt(&Entry->front(), DT);
>>>>> -
>>>>> - while (BBs.size() >= 2) {
>>>>> - BasicBlock *BB, *BB1, *BB2;
>>>>> - BB1 = *BBs.begin();
>>>>> - BB2 = *std::next(BBs.begin());
>>>>> - BB = DT->findNearestCommonDominator(BB1, BB2);
>>>>> - if (BB == Entry)
>>>>> - return getMatInsertPt(&Entry->front(), DT);
>>>>> - BBs.erase(BB1);
>>>>> - BBs.erase(BB2);
>>>>> - BBs.insert(BB);
>>>>> - }
>>>>> - assert((BBs.size() == 1) && "Expected only one element.");
>>>>> - Instruction &FirstInst = (*BBs.begin())->front();
>>>>> - return getMatInsertPt(&FirstInst, DT);
>>>>> + findAndMakeBaseConstant(MinValItr, ConstCandVec.end());
>>>>> }
>>>>>
>>>>> /// \brief Emit materialization code for all rebased constants and update their
>>>>> /// users.
>>>>> -void ConstantHoisting::EmitBaseConstants(Function &F, User *U,
>>>>> - Instruction *Base, Constant *Offset,
>>>>> - ConstantInt *OriginalConstant) {
>>>>> - if (Instruction *I = dyn_cast<Instruction>(U)) {
>>>>> - Instruction *Mat = Base;
>>>>> - if (!Offset->isNullValue()) {
>>>>> - Mat = BinaryOperator::Create(Instruction::Add, Base, Offset,
>>>>> - "const_mat", getMatInsertPt(I, DT));
>>>>> -
>>>>> - // Use the same debug location as the instruction we are about to update.
>>>>> - Mat->setDebugLoc(I->getDebugLoc());
>>>>> -
>>>>> - DEBUG(dbgs() << "Materialize constant (" << *Base->getOperand(0)
>>>>> - << " + " << *Offset << ") in BB "
>>>>> - << I->getParent()->getName() << '\n' << *Mat << '\n');
>>>>> - }
>>>>> - DEBUG(dbgs() << "Update: " << *I << '\n');
>>>>> - I->replaceUsesOfWith(OriginalConstant, Mat);
>>>>> - DEBUG(dbgs() << "To: " << *I << '\n');
>>>>> +void ConstantHoisting::emitBaseConstants(Instruction *Base, Constant *Offset,
>>>>> + const ConstantUser &CU) {
>>>>> + Instruction *Mat = Base;
>>>>> + if (Offset) {
>>>>> + Instruction *InsertionPt = findMatInsertPt(CU.Inst, CU.OpndIdx);
>>>>> + Mat = BinaryOperator::Create(Instruction::Add, Base, Offset,
>>>>> + "const_mat", InsertionPt);
>>>>> +
>>>>> + DEBUG(dbgs() << "Materialize constant (" << *Base->getOperand(0)
>>>>> + << " + " << *Offset << ") in BB "
>>>>> + << Mat->getParent()->getName() << '\n' << *Mat << '\n');
>>>>> + Mat->setDebugLoc(CU.Inst->getDebugLoc());
>>>>> + }
>>>>> + Value *Opnd = CU.Inst->getOperand(CU.OpndIdx);
>>>>> +
>>>>> + // Visit constant integer.
>>>>> + if (isa<ConstantInt>(Opnd)) {
>>>>> + DEBUG(dbgs() << "Update: " << *CU.Inst << '\n');
>>>>> + CU.Inst->setOperand(CU.OpndIdx, Mat);
>>>>> + DEBUG(dbgs() << "To : " << *CU.Inst << '\n');
>>>>> return;
>>>>> }
>>>>> - assert(isa<ConstantExpr>(U) && "Expected a ConstantExpr.");
>>>>> - ConstantExpr *CE = cast<ConstantExpr>(U);
>>>>> - SmallVector<std::pair<Instruction *, Instruction *>, 8> WorkList;
>>>>> - DEBUG(dbgs() << "Visit ConstantExpr " << *CE << '\n');
>>>>> - for (User *UU : CE->users()) {
>>>>> - DEBUG(dbgs() << "Check user "; UU->print(dbgs()); dbgs() << '\n');
>>>>> - // We only handel instructions here and won't walk down a ConstantExpr chain
>>>>> - // to replace all ConstExpr with instructions.
>>>>> - if (Instruction *I = dyn_cast<Instruction>(UU)) {
>>>>> - // Only update constant expressions in the current function.
>>>>> - if (I->getParent()->getParent() != &F) {
>>>>> - DEBUG(dbgs() << "Not in the same function - skip.\n");
>>>>> - continue;
>>>>> - }
>>>>>
>>>>> - Instruction *Mat = Base;
>>>>> - Instruction *InsertBefore = getMatInsertPt(I, DT);
>>>>> - if (!Offset->isNullValue()) {
>>>>> - Mat = BinaryOperator::Create(Instruction::Add, Base, Offset,
>>>>> - "const_mat", InsertBefore);
>>>>> -
>>>>> - // Use the same debug location as the instruction we are about to
>>>>> - // update.
>>>>> - Mat->setDebugLoc(I->getDebugLoc());
>>>>> -
>>>>> - DEBUG(dbgs() << "Materialize constant (" << *Base->getOperand(0)
>>>>> - << " + " << *Offset << ") in BB "
>>>>> - << I->getParent()->getName() << '\n' << *Mat << '\n');
>>>>> - }
>>>>> - Instruction *ICE = CE->getAsInstruction();
>>>>> - ICE->replaceUsesOfWith(OriginalConstant, Mat);
>>>>> - ICE->insertBefore(InsertBefore);
>>>>> -
>>>>> - // Use the same debug location as the instruction we are about to update.
>>>>> - ICE->setDebugLoc(I->getDebugLoc());
>>>>> -
>>>>> - WorkList.push_back(std::make_pair(I, ICE));
>>>>> - } else {
>>>>> - DEBUG(dbgs() << "Not an instruction - skip.\n");
>>>>> + // Visit cast instruction.
>>>>> + if (auto CastInst = dyn_cast<Instruction>(Opnd)) {
>>>>> + assert(CastInst->isCast() && "Expected an cast instruction!");
>>>>> + // Check if we already have visited this cast instruction before to avoid
>>>>> + // unnecessary cloning.
>>>>> + Instruction *&ClonedCastInst = ClonedCastMap[CastInst];
>>>>> + if (!ClonedCastInst) {
>>>>> + ClonedCastInst = CastInst->clone();
>>>>> + ClonedCastInst->setOperand(0, Mat);
>>>>> + ClonedCastInst->insertAfter(CastInst);
>>>>> + // Use the same debug location as the original cast instruction.
>>>>> + ClonedCastInst->setDebugLoc(CastInst->getDebugLoc());
>>>>> + DEBUG(dbgs() << "Clone instruction: " << *ClonedCastInst << '\n'
>>>>> + << "To : " << *CastInst << '\n');
>>>>> }
>>>>> +
>>>>> + DEBUG(dbgs() << "Update: " << *CU.Inst << '\n');
>>>>> + CU.Inst->setOperand(CU.OpndIdx, ClonedCastInst);
>>>>> + DEBUG(dbgs() << "To : " << *CU.Inst << '\n');
>>>>> + return;
>>>>> }
>>>>> - SmallVectorImpl<std::pair<Instruction *, Instruction *> >::iterator I, E;
>>>>> - for (I = WorkList.begin(), E = WorkList.end(); I != E; ++I) {
>>>>> - DEBUG(dbgs() << "Create instruction: " << *I->second << '\n');
>>>>> - DEBUG(dbgs() << "Update: " << *I->first << '\n');
>>>>> - I->first->replaceUsesOfWith(CE, I->second);
>>>>> - DEBUG(dbgs() << "To: " << *I->first << '\n');
>>>>> +
>>>>> + // Visit constant expression.
>>>>> + if (auto ConstExpr = dyn_cast<ConstantExpr>(Opnd)) {
>>>>> + Instruction *ConstExprInst = ConstExpr->getAsInstruction();
>>>>> + ConstExprInst->setOperand(0, Mat);
>>>>> + ConstExprInst->insertBefore(findMatInsertPt(CU.Inst, CU.OpndIdx));
>>>>> +
>>>>> + // Use the same debug location as the instruction we are about to update.
>>>>> + ConstExprInst->setDebugLoc(CU.Inst->getDebugLoc());
>>>>> +
>>>>> + DEBUG(dbgs() << "Create instruction: " << *ConstExprInst << '\n'
>>>>> + << "From : " << *ConstExpr << '\n');
>>>>> + DEBUG(dbgs() << "Update: " << *CU.Inst << '\n');
>>>>> + CU.Inst->setOperand(CU.OpndIdx, ConstExprInst);
>>>>> + DEBUG(dbgs() << "To : " << *CU.Inst << '\n');
>>>>> + return;
>>>>> }
>>>>> }
>>>>>
>>>>> /// \brief Hoist and hide the base constant behind a bitcast and emit
>>>>> /// materialization code for derived constants.
>>>>> -bool ConstantHoisting::EmitBaseConstants(Function &F) {
>>>>> +bool ConstantHoisting::emitBaseConstants() {
>>>>> bool MadeChange = false;
>>>>> - SmallVectorImpl<ConstantInfo>::iterator CI, CE;
>>>>> - for (CI = Constants.begin(), CE = Constants.end(); CI != CE; ++CI) {
>>>>> + for (auto const &ConstInfo : ConstantVec) {
>>>>> // Hoist and hide the base constant behind a bitcast.
>>>>> - Instruction *IP = FindConstantInsertionPoint(F, *CI);
>>>>> - IntegerType *Ty = CI->BaseConstant->getType();
>>>>> - Instruction *Base = new BitCastInst(CI->BaseConstant, Ty, "const", IP);
>>>>> - DEBUG(dbgs() << "Hoist constant (" << *CI->BaseConstant << ") to BB "
>>>>> - << IP->getParent()->getName() << '\n');
>>>>> + Instruction *IP = findConstantInsertionPoint(ConstInfo);
>>>>> + IntegerType *Ty = ConstInfo.BaseConstant->getType();
>>>>> + Instruction *Base =
>>>>> + new BitCastInst(ConstInfo.BaseConstant, Ty, "const", IP);
>>>>> + DEBUG(dbgs() << "Hoist constant (" << *ConstInfo.BaseConstant << ") to BB "
>>>>> + << IP->getParent()->getName() << '\n' << *Base << '\n');
>>>>> NumConstantsHoisted++;
>>>>>
>>>>> // Emit materialization code for all rebased constants.
>>>>> - ConstantInfo::RebasedConstantListType::iterator RCI, RCE;
>>>>> - for (RCI = CI->RebasedConstants.begin(), RCE = CI->RebasedConstants.end();
>>>>> - RCI != RCE; ++RCI) {
>>>>> + for (auto const &RCI : ConstInfo.RebasedConstants) {
>>>>> NumConstantsRebased++;
>>>>> - for (SmallVectorImpl<User *>::iterator U = RCI->Uses.begin(),
>>>>> - E = RCI->Uses.end(); U != E; ++U)
>>>>> - EmitBaseConstants(F, *U, Base, RCI->Offset, RCI->OriginalConstant);
>>>>> + for (auto const &U : RCI.Uses)
>>>>> + emitBaseConstants(Base, RCI.Offset, U);
>>>>> }
>>>>>
>>>>> // Use the same debug location as the last user of the constant.
>>>>> @@ -432,27 +554,37 @@ bool ConstantHoisting::EmitBaseConstants
>>>>> return MadeChange;
>>>>> }
>>>>>
>>>>> -/// \brief Optimize expensive integer constants in the given function.
>>>>> -bool ConstantHoisting::OptimizeConstants(Function &F) {
>>>>> - bool MadeChange = false;
>>>>> +/// \brief Check all cast instructions we made a copy of and remove them if they
>>>>> +/// have no more users.
>>>>> +void ConstantHoisting::deleteDeadCastInst() const {
>>>>> + for (auto const &I : ClonedCastMap)
>>>>> + if (I.first->use_empty())
>>>>> + I.first->removeFromParent();
>>>>> +}
>>>>>
>>>>> +/// \brief Optimize expensive integer constants in the given function.
>>>>> +bool ConstantHoisting::optimizeConstants(Function &Fn) {
>>>>> // Collect all constant candidates.
>>>>> - CollectConstants(F);
>>>>> + collectConstantCandidates(Fn);
>>>>>
>>>>> - // There are no constants to worry about.
>>>>> - if (ConstantMap.empty())
>>>>> - return MadeChange;
>>>>> + // There are no constant candidates to worry about.
>>>>> + if (ConstCandVec.empty())
>>>>> + return false;
>>>>>
>>>>> // Combine constants that can be easily materialized with an add from a common
>>>>> // base constant.
>>>>> - FindBaseConstants();
>>>>> + findBaseConstants();
>>>>> +
>>>>> + // There are no constants to emit.
>>>>> + if (ConstantVec.empty())
>>>>> + return false;
>>>>>
>>>>> // Finally hoist the base constant and emit materializating code for dependent
>>>>> // constants.
>>>>> - MadeChange |= EmitBaseConstants(F);
>>>>> + bool MadeChange = emitBaseConstants();
>>>>>
>>>>> - ConstantMap.clear();
>>>>> - Constants.clear();
>>>>> + // Cleanup dead instructions.
>>>>> + deleteDeadCastInst();
>>>>>
>>>>> return MadeChange;
>>>>> }
>>>>>
>>>>> Modified: llvm/trunk/test/CodeGen/X86/lsr-interesting-step.ll
>>>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/lsr-interesting-step.ll?rev=204389&r1=204388&r2=204389&view=diff
>>>>> ==============================================================================
>>>>> --- llvm/trunk/test/CodeGen/X86/lsr-interesting-step.ll (original)
>>>>> +++ llvm/trunk/test/CodeGen/X86/lsr-interesting-step.ll Thu Mar 20 14:55:52 2014
>>>>> @@ -3,26 +3,24 @@
>>>>> ; The inner loop should require only one add (and no leas either).
>>>>> ; rdar://8100380
>>>>>
>>>>> -; CHECK: BB0_3:
>>>>> -; CHECK-NEXT: movb $0, flags(%rdx)
>>>>> -; CHECK-NEXT: addq %rax, %rdx
>>>>> -; CHECK-NEXT: cmpq $8192, %rdx
>>>>> +; CHECK: BB0_2:
>>>>> +; CHECK-NEXT: movb $0, flags(%rcx)
>>>>> +; CHECK-NEXT: addq %rax, %rcx
>>>>> +; CHECK-NEXT: cmpq $8192, %rcx
>>>>> ; CHECK-NEXT: jl
>>>>>
>>>>> @flags = external global [8192 x i8], align 16 ; <[8192 x i8]*> [#uses=1]
>>>>>
>>>>> define void @foo() nounwind {
>>>>> entry:
>>>>> - %tmp = icmp slt i64 2, 8192 ; <i1> [#uses=1]
>>>>> - br i1 %tmp, label %bb, label %bb21
>>>>> + br label %bb
>>>>>
>>>>> bb: ; preds = %entry
>>>>> br label %bb7
>>>>>
>>>>> bb7: ; preds = %bb, %bb17
>>>>> %tmp8 = phi i64 [ %tmp18, %bb17 ], [ 2, %bb ] ; <i64> [#uses=2]
>>>>> - %tmp9 = icmp slt i64 2, 8192 ; <i1> [#uses=1]
>>>>> - br i1 %tmp9, label %bb10, label %bb17
>>>>> + br label %bb10
>>>>>
>>>>> bb10: ; preds = %bb7
>>>>> br label %bb11
>>>>>
>>>>> Modified: llvm/trunk/test/CodeGen/X86/negate-add-zero.ll
>>>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/negate-add-zero.ll?rev=204389&r1=204388&r2=204389&view=diff
>>>>> ==============================================================================
>>>>> --- llvm/trunk/test/CodeGen/X86/negate-add-zero.ll (original)
>>>>> +++ llvm/trunk/test/CodeGen/X86/negate-add-zero.ll Thu Mar 20 14:55:52 2014
>>>>> @@ -827,9 +827,7 @@ declare void @_ZN11MatrixTools9transpose
>>>>> declare void @_ZN21HNodeTranslateRotate311toCartesianEv(%struct.HNodeTranslateRotate3*)
>>>>>
>>>>> define linkonce void @_ZN21HNodeTranslateRotate36setVelERK9CDSVectorIdLi1EN3CDS12DefaultAllocEE(%struct.HNodeTranslateRotate3* %this, %"struct.CDSVector<double,0,CDS::DefaultAlloc>"* %velv) {
>>>>> -entry:
>>>>> - %0 = add i32 0, -1 ; <i32> [#uses=1]
>>>>> - %1 = getelementptr double* null, i32 %0 ; <double*> [#uses=1]
>>>>> + %1 = getelementptr double* null, i32 -1 ; <double*> [#uses=1]
>>>>> %2 = load double* %1, align 8 ; <double> [#uses=1]
>>>>> %3 = load double* null, align 8 ; <double> [#uses=2]
>>>>> %4 = load double* null, align 8 ; <double> [#uses=2]
>>>>> @@ -890,13 +888,12 @@ entry:
>>>>> store double %52, double* %55, align 8
>>>>> %56 = getelementptr %struct.HNodeTranslateRotate3* %this, i32 0, i32 0, i32 10, i32 0, i32 0, i32 2 ; <double*> [#uses=1]
>>>>> store double %53, double* %56, align 8
>>>>> - %57 = add i32 0, 4 ; <i32> [#uses=1]
>>>>> - %58 = getelementptr %"struct.SubVector<CDSVector<double, 1, CDS::DefaultAlloc> >"* null, i32 0, i32 0 ; <%"struct.CDSVector<double,0,CDS::DefaultAlloc>"**> [#uses=1]
>>>>> - store %"struct.CDSVector<double,0,CDS::DefaultAlloc>"* %velv, %"struct.CDSVector<double,0,CDS::DefaultAlloc>"** %58, align 8
>>>>> - %59 = getelementptr %"struct.SubVector<CDSVector<double, 1, CDS::DefaultAlloc> >"* null, i32 0, i32 1 ; <i32*> [#uses=1]
>>>>> - store i32 %57, i32* %59, align 4
>>>>> - %60 = getelementptr %"struct.SubVector<CDSVector<double, 1, CDS::DefaultAlloc> >"* null, i32 0, i32 2 ; <i32*> [#uses=1]
>>>>> - store i32 3, i32* %60, align 8
>>>>> + %57 = getelementptr %"struct.SubVector<CDSVector<double, 1, CDS::DefaultAlloc> >"* null, i32 0, i32 0 ; <%"struct.CDSVector<double,0,CDS::DefaultAlloc>"**> [#uses=1]
>>>>> + store %"struct.CDSVector<double,0,CDS::DefaultAlloc>"* %velv, %"struct.CDSVector<double,0,CDS::DefaultAlloc>"** %57, align 8
>>>>> + %58 = getelementptr %"struct.SubVector<CDSVector<double, 1, CDS::DefaultAlloc> >"* null, i32 0, i32 1 ; <i32*> [#uses=1]
>>>>> + store i32 4, i32* %58, align 4
>>>>> + %59 = getelementptr %"struct.SubVector<CDSVector<double, 1, CDS::DefaultAlloc> >"* null, i32 0, i32 2 ; <i32*> [#uses=1]
>>>>> + store i32 3, i32* %59, align 8
>>>>> unreachable
>>>>> }
>>>>>
>>>>>
>>>>> Modified: llvm/trunk/test/Transforms/ConstantHoisting/X86/phi.ll
>>>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/ConstantHoisting/X86/phi.ll?rev=204389&r1=204388&r2=204389&view=diff
>>>>> ==============================================================================
>>>>> --- llvm/trunk/test/Transforms/ConstantHoisting/X86/phi.ll (original)
>>>>> +++ llvm/trunk/test/Transforms/ConstantHoisting/X86/phi.ll Thu Mar 20 14:55:52 2014
>>>>> @@ -19,11 +19,11 @@ return:
>>>>> ret i8* %retval.0
>>>>>
>>>>> ; CHECK-LABEL: @test1
>>>>> -; CHECK: entry:
>>>>> -; CHECK: %const_mat = add i64 %const, 1
>>>>> -; CHECK-NEXT: %1 = inttoptr i64 %const_mat to i8*
>>>>> -; CHECK-NEXT: br i1 %cmp
>>>>> -; CHECK: %retval.0 = phi i8* [ null, %entry ], [ %1, %if.end ]
>>>>> +; CHECK: if.end:
>>>>> +; CHECK: %2 = inttoptr i64 %const to i8*
>>>>> +; CHECK-NEXT: br
>>>>> +; CHECK: return:
>>>>> +; CHECK-NEXT: %retval.0 = phi i8* [ null, %entry ], [ %2, %if.end ]
>>>>> }
>>>>>
>>>>> define void @test2(i1 %cmp, i64** %tmp) {
>>>>>
>>>>>
>>>>> _______________________________________________
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>>>>> llvm-commits at cs.uiuc.edu
>>>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>>
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