forked from OSchip/llvm-project
657 lines
27 KiB
C++
657 lines
27 KiB
C++
//===- InstCombineInternal.h - InstCombine pass internals -------*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
/// \file
|
|
///
|
|
/// This file provides internal interfaces used to implement the InstCombine.
|
|
///
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_LIB_TRANSFORMS_INSTCOMBINE_INSTCOMBINEINTERNAL_H
|
|
#define LLVM_LIB_TRANSFORMS_INSTCOMBINE_INSTCOMBINEINTERNAL_H
|
|
|
|
#include "llvm/Analysis/AliasAnalysis.h"
|
|
#include "llvm/Analysis/AssumptionCache.h"
|
|
#include "llvm/Analysis/LoopInfo.h"
|
|
#include "llvm/Analysis/TargetFolder.h"
|
|
#include "llvm/Analysis/ValueTracking.h"
|
|
#include "llvm/IR/Dominators.h"
|
|
#include "llvm/IR/IRBuilder.h"
|
|
#include "llvm/IR/InstVisitor.h"
|
|
#include "llvm/IR/IntrinsicInst.h"
|
|
#include "llvm/IR/Operator.h"
|
|
#include "llvm/IR/PatternMatch.h"
|
|
#include "llvm/Pass.h"
|
|
#include "llvm/Transforms/InstCombine/InstCombineWorklist.h"
|
|
|
|
#define DEBUG_TYPE "instcombine"
|
|
|
|
namespace llvm {
|
|
class CallSite;
|
|
class DataLayout;
|
|
class DominatorTree;
|
|
class TargetLibraryInfo;
|
|
class DbgDeclareInst;
|
|
class MemIntrinsic;
|
|
class MemSetInst;
|
|
|
|
/// \brief Assign a complexity or rank value to LLVM Values.
|
|
///
|
|
/// This routine maps IR values to various complexity ranks:
|
|
/// 0 -> undef
|
|
/// 1 -> Constants
|
|
/// 2 -> Other non-instructions
|
|
/// 3 -> Arguments
|
|
/// 3 -> Unary operations
|
|
/// 4 -> Other instructions
|
|
static inline unsigned getComplexity(Value *V) {
|
|
if (isa<Instruction>(V)) {
|
|
if (BinaryOperator::isNeg(V) || BinaryOperator::isFNeg(V) ||
|
|
BinaryOperator::isNot(V))
|
|
return 3;
|
|
return 4;
|
|
}
|
|
if (isa<Argument>(V))
|
|
return 3;
|
|
return isa<Constant>(V) ? (isa<UndefValue>(V) ? 0 : 1) : 2;
|
|
}
|
|
|
|
/// \brief Add one to a Constant
|
|
static inline Constant *AddOne(Constant *C) {
|
|
return ConstantExpr::getAdd(C, ConstantInt::get(C->getType(), 1));
|
|
}
|
|
/// \brief Subtract one from a Constant
|
|
static inline Constant *SubOne(Constant *C) {
|
|
return ConstantExpr::getSub(C, ConstantInt::get(C->getType(), 1));
|
|
}
|
|
|
|
/// \brief Return true if the specified value is free to invert (apply ~ to).
|
|
/// This happens in cases where the ~ can be eliminated. If WillInvertAllUses
|
|
/// is true, work under the assumption that the caller intends to remove all
|
|
/// uses of V and only keep uses of ~V.
|
|
///
|
|
static inline bool IsFreeToInvert(Value *V, bool WillInvertAllUses) {
|
|
// ~(~(X)) -> X.
|
|
if (BinaryOperator::isNot(V))
|
|
return true;
|
|
|
|
// Constants can be considered to be not'ed values.
|
|
if (isa<ConstantInt>(V))
|
|
return true;
|
|
|
|
// A vector of constant integers can be inverted easily.
|
|
Constant *CV;
|
|
if (V->getType()->isVectorTy() && match(V, PatternMatch::m_Constant(CV))) {
|
|
unsigned NumElts = V->getType()->getVectorNumElements();
|
|
for (unsigned i = 0; i != NumElts; ++i) {
|
|
Constant *Elt = CV->getAggregateElement(i);
|
|
if (!Elt)
|
|
return false;
|
|
|
|
if (isa<UndefValue>(Elt))
|
|
continue;
|
|
|
|
if (!isa<ConstantInt>(Elt))
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
// Compares can be inverted if all of their uses are being modified to use the
|
|
// ~V.
|
|
if (isa<CmpInst>(V))
|
|
return WillInvertAllUses;
|
|
|
|
// If `V` is of the form `A + Constant` then `-1 - V` can be folded into `(-1
|
|
// - Constant) - A` if we are willing to invert all of the uses.
|
|
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(V))
|
|
if (BO->getOpcode() == Instruction::Add ||
|
|
BO->getOpcode() == Instruction::Sub)
|
|
if (isa<Constant>(BO->getOperand(0)) || isa<Constant>(BO->getOperand(1)))
|
|
return WillInvertAllUses;
|
|
|
|
return false;
|
|
}
|
|
|
|
|
|
/// \brief Specific patterns of overflow check idioms that we match.
|
|
enum OverflowCheckFlavor {
|
|
OCF_UNSIGNED_ADD,
|
|
OCF_SIGNED_ADD,
|
|
OCF_UNSIGNED_SUB,
|
|
OCF_SIGNED_SUB,
|
|
OCF_UNSIGNED_MUL,
|
|
OCF_SIGNED_MUL,
|
|
|
|
OCF_INVALID
|
|
};
|
|
|
|
/// \brief Returns the OverflowCheckFlavor corresponding to a overflow_with_op
|
|
/// intrinsic.
|
|
static inline OverflowCheckFlavor
|
|
IntrinsicIDToOverflowCheckFlavor(unsigned ID) {
|
|
switch (ID) {
|
|
default:
|
|
return OCF_INVALID;
|
|
case Intrinsic::uadd_with_overflow:
|
|
return OCF_UNSIGNED_ADD;
|
|
case Intrinsic::sadd_with_overflow:
|
|
return OCF_SIGNED_ADD;
|
|
case Intrinsic::usub_with_overflow:
|
|
return OCF_UNSIGNED_SUB;
|
|
case Intrinsic::ssub_with_overflow:
|
|
return OCF_SIGNED_SUB;
|
|
case Intrinsic::umul_with_overflow:
|
|
return OCF_UNSIGNED_MUL;
|
|
case Intrinsic::smul_with_overflow:
|
|
return OCF_SIGNED_MUL;
|
|
}
|
|
}
|
|
|
|
/// \brief The core instruction combiner logic.
|
|
///
|
|
/// This class provides both the logic to recursively visit instructions and
|
|
/// combine them.
|
|
class LLVM_LIBRARY_VISIBILITY InstCombiner
|
|
: public InstVisitor<InstCombiner, Instruction *> {
|
|
// FIXME: These members shouldn't be public.
|
|
public:
|
|
/// \brief A worklist of the instructions that need to be simplified.
|
|
InstCombineWorklist &Worklist;
|
|
|
|
/// \brief An IRBuilder that automatically inserts new instructions into the
|
|
/// worklist.
|
|
typedef IRBuilder<TargetFolder, IRBuilderCallbackInserter> BuilderTy;
|
|
BuilderTy *Builder;
|
|
|
|
private:
|
|
// Mode in which we are running the combiner.
|
|
const bool MinimizeSize;
|
|
/// Enable combines that trigger rarely but are costly in compiletime.
|
|
const bool ExpensiveCombines;
|
|
|
|
AliasAnalysis *AA;
|
|
|
|
// Required analyses.
|
|
AssumptionCache &AC;
|
|
TargetLibraryInfo &TLI;
|
|
DominatorTree &DT;
|
|
const DataLayout &DL;
|
|
|
|
// Optional analyses. When non-null, these can both be used to do better
|
|
// combining and will be updated to reflect any changes.
|
|
LoopInfo *LI;
|
|
|
|
bool MadeIRChange;
|
|
|
|
public:
|
|
InstCombiner(InstCombineWorklist &Worklist, BuilderTy *Builder,
|
|
bool MinimizeSize, bool ExpensiveCombines, AliasAnalysis *AA,
|
|
AssumptionCache &AC, TargetLibraryInfo &TLI,
|
|
DominatorTree &DT, const DataLayout &DL, LoopInfo *LI)
|
|
: Worklist(Worklist), Builder(Builder), MinimizeSize(MinimizeSize),
|
|
ExpensiveCombines(ExpensiveCombines), AA(AA), AC(AC), TLI(TLI), DT(DT),
|
|
DL(DL), LI(LI), MadeIRChange(false) {}
|
|
|
|
/// \brief Run the combiner over the entire worklist until it is empty.
|
|
///
|
|
/// \returns true if the IR is changed.
|
|
bool run();
|
|
|
|
AssumptionCache &getAssumptionCache() const { return AC; }
|
|
|
|
const DataLayout &getDataLayout() const { return DL; }
|
|
|
|
DominatorTree &getDominatorTree() const { return DT; }
|
|
|
|
LoopInfo *getLoopInfo() const { return LI; }
|
|
|
|
TargetLibraryInfo &getTargetLibraryInfo() const { return TLI; }
|
|
|
|
// Visitation implementation - Implement instruction combining for different
|
|
// instruction types. The semantics are as follows:
|
|
// Return Value:
|
|
// null - No change was made
|
|
// I - Change was made, I is still valid, I may be dead though
|
|
// otherwise - Change was made, replace I with returned instruction
|
|
//
|
|
Instruction *visitAdd(BinaryOperator &I);
|
|
Instruction *visitFAdd(BinaryOperator &I);
|
|
Value *OptimizePointerDifference(Value *LHS, Value *RHS, Type *Ty);
|
|
Instruction *visitSub(BinaryOperator &I);
|
|
Instruction *visitFSub(BinaryOperator &I);
|
|
Instruction *visitMul(BinaryOperator &I);
|
|
Value *foldFMulConst(Instruction *FMulOrDiv, Constant *C,
|
|
Instruction *InsertBefore);
|
|
Instruction *visitFMul(BinaryOperator &I);
|
|
Instruction *visitURem(BinaryOperator &I);
|
|
Instruction *visitSRem(BinaryOperator &I);
|
|
Instruction *visitFRem(BinaryOperator &I);
|
|
bool SimplifyDivRemOfSelect(BinaryOperator &I);
|
|
Instruction *commonRemTransforms(BinaryOperator &I);
|
|
Instruction *commonIRemTransforms(BinaryOperator &I);
|
|
Instruction *commonDivTransforms(BinaryOperator &I);
|
|
Instruction *commonIDivTransforms(BinaryOperator &I);
|
|
Instruction *visitUDiv(BinaryOperator &I);
|
|
Instruction *visitSDiv(BinaryOperator &I);
|
|
Instruction *visitFDiv(BinaryOperator &I);
|
|
Value *simplifyRangeCheck(ICmpInst *Cmp0, ICmpInst *Cmp1, bool Inverted);
|
|
Value *FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS);
|
|
Value *FoldAndOfFCmps(FCmpInst *LHS, FCmpInst *RHS);
|
|
Instruction *visitAnd(BinaryOperator &I);
|
|
Value *FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS, Instruction *CxtI);
|
|
Value *FoldOrOfFCmps(FCmpInst *LHS, FCmpInst *RHS);
|
|
Instruction *FoldOrWithConstants(BinaryOperator &I, Value *Op, Value *A,
|
|
Value *B, Value *C);
|
|
Instruction *FoldXorWithConstants(BinaryOperator &I, Value *Op, Value *A,
|
|
Value *B, Value *C);
|
|
Instruction *visitOr(BinaryOperator &I);
|
|
Instruction *visitXor(BinaryOperator &I);
|
|
Instruction *visitShl(BinaryOperator &I);
|
|
Instruction *visitAShr(BinaryOperator &I);
|
|
Instruction *visitLShr(BinaryOperator &I);
|
|
Instruction *commonShiftTransforms(BinaryOperator &I);
|
|
Instruction *visitFCmpInst(FCmpInst &I);
|
|
Instruction *visitICmpInst(ICmpInst &I);
|
|
Instruction *FoldShiftByConstant(Value *Op0, Constant *Op1,
|
|
BinaryOperator &I);
|
|
Instruction *commonCastTransforms(CastInst &CI);
|
|
Instruction *commonPointerCastTransforms(CastInst &CI);
|
|
Instruction *visitTrunc(TruncInst &CI);
|
|
Instruction *visitZExt(ZExtInst &CI);
|
|
Instruction *visitSExt(SExtInst &CI);
|
|
Instruction *visitFPTrunc(FPTruncInst &CI);
|
|
Instruction *visitFPExt(CastInst &CI);
|
|
Instruction *visitFPToUI(FPToUIInst &FI);
|
|
Instruction *visitFPToSI(FPToSIInst &FI);
|
|
Instruction *visitUIToFP(CastInst &CI);
|
|
Instruction *visitSIToFP(CastInst &CI);
|
|
Instruction *visitPtrToInt(PtrToIntInst &CI);
|
|
Instruction *visitIntToPtr(IntToPtrInst &CI);
|
|
Instruction *visitBitCast(BitCastInst &CI);
|
|
Instruction *visitAddrSpaceCast(AddrSpaceCastInst &CI);
|
|
Instruction *FoldItoFPtoI(Instruction &FI);
|
|
Instruction *visitSelectInst(SelectInst &SI);
|
|
Instruction *visitCallInst(CallInst &CI);
|
|
Instruction *visitInvokeInst(InvokeInst &II);
|
|
|
|
Instruction *SliceUpIllegalIntegerPHI(PHINode &PN);
|
|
Instruction *visitPHINode(PHINode &PN);
|
|
Instruction *visitGetElementPtrInst(GetElementPtrInst &GEP);
|
|
Instruction *visitAllocaInst(AllocaInst &AI);
|
|
Instruction *visitAllocSite(Instruction &FI);
|
|
Instruction *visitFree(CallInst &FI);
|
|
Instruction *visitLoadInst(LoadInst &LI);
|
|
Instruction *visitStoreInst(StoreInst &SI);
|
|
Instruction *visitBranchInst(BranchInst &BI);
|
|
Instruction *visitSwitchInst(SwitchInst &SI);
|
|
Instruction *visitReturnInst(ReturnInst &RI);
|
|
Instruction *visitInsertValueInst(InsertValueInst &IV);
|
|
Instruction *visitInsertElementInst(InsertElementInst &IE);
|
|
Instruction *visitExtractElementInst(ExtractElementInst &EI);
|
|
Instruction *visitShuffleVectorInst(ShuffleVectorInst &SVI);
|
|
Instruction *visitExtractValueInst(ExtractValueInst &EV);
|
|
Instruction *visitLandingPadInst(LandingPadInst &LI);
|
|
Instruction *visitVAStartInst(VAStartInst &I);
|
|
Instruction *visitVACopyInst(VACopyInst &I);
|
|
|
|
/// Specify what to return for unhandled instructions.
|
|
Instruction *visitInstruction(Instruction &I) { return nullptr; }
|
|
|
|
/// True when DB dominates all uses of DI except UI.
|
|
/// UI must be in the same block as DI.
|
|
/// The routine checks that the DI parent and DB are different.
|
|
bool dominatesAllUses(const Instruction *DI, const Instruction *UI,
|
|
const BasicBlock *DB) const;
|
|
|
|
/// Try to replace select with select operand SIOpd in SI-ICmp sequence.
|
|
bool replacedSelectWithOperand(SelectInst *SI, const ICmpInst *Icmp,
|
|
const unsigned SIOpd);
|
|
|
|
private:
|
|
bool ShouldChangeType(unsigned FromBitWidth, unsigned ToBitWidth) const;
|
|
bool ShouldChangeType(Type *From, Type *To) const;
|
|
Value *dyn_castNegVal(Value *V) const;
|
|
Value *dyn_castFNegVal(Value *V, bool NoSignedZero = false) const;
|
|
Type *FindElementAtOffset(PointerType *PtrTy, int64_t Offset,
|
|
SmallVectorImpl<Value *> &NewIndices);
|
|
|
|
/// Classify whether a cast is worth optimizing.
|
|
///
|
|
/// This is a helper to decide whether the simplification of
|
|
/// logic(cast(A), cast(B)) to cast(logic(A, B)) should be performed.
|
|
///
|
|
/// \param CI The cast we are interested in.
|
|
///
|
|
/// \return true if this cast actually results in any code being generated and
|
|
/// if it cannot already be eliminated by some other transformation.
|
|
bool shouldOptimizeCast(CastInst *CI);
|
|
|
|
/// \brief Try to optimize a sequence of instructions checking if an operation
|
|
/// on LHS and RHS overflows.
|
|
///
|
|
/// If this overflow check is done via one of the overflow check intrinsics,
|
|
/// then CtxI has to be the call instruction calling that intrinsic. If this
|
|
/// overflow check is done by arithmetic followed by a compare, then CtxI has
|
|
/// to be the arithmetic instruction.
|
|
///
|
|
/// If a simplification is possible, stores the simplified result of the
|
|
/// operation in OperationResult and result of the overflow check in
|
|
/// OverflowResult, and return true. If no simplification is possible,
|
|
/// returns false.
|
|
bool OptimizeOverflowCheck(OverflowCheckFlavor OCF, Value *LHS, Value *RHS,
|
|
Instruction &CtxI, Value *&OperationResult,
|
|
Constant *&OverflowResult);
|
|
|
|
Instruction *visitCallSite(CallSite CS);
|
|
Instruction *tryOptimizeCall(CallInst *CI);
|
|
bool transformConstExprCastCall(CallSite CS);
|
|
Instruction *transformCallThroughTrampoline(CallSite CS,
|
|
IntrinsicInst *Tramp);
|
|
|
|
/// Transform (zext icmp) to bitwise / integer operations in order to
|
|
/// eliminate it.
|
|
///
|
|
/// \param ICI The icmp of the (zext icmp) pair we are interested in.
|
|
/// \parem CI The zext of the (zext icmp) pair we are interested in.
|
|
/// \param DoTransform Pass false to just test whether the given (zext icmp)
|
|
/// would be transformed. Pass true to actually perform the transformation.
|
|
///
|
|
/// \return null if the transformation cannot be performed. If the
|
|
/// transformation can be performed the new instruction that replaces the
|
|
/// (zext icmp) pair will be returned (if \p DoTransform is false the
|
|
/// unmodified \p ICI will be returned in this case).
|
|
Instruction *transformZExtICmp(ICmpInst *ICI, ZExtInst &CI,
|
|
bool DoTransform = true);
|
|
|
|
Instruction *transformSExtICmp(ICmpInst *ICI, Instruction &CI);
|
|
bool WillNotOverflowSignedAdd(Value *LHS, Value *RHS, Instruction &CxtI);
|
|
bool WillNotOverflowSignedSub(Value *LHS, Value *RHS, Instruction &CxtI);
|
|
bool WillNotOverflowUnsignedSub(Value *LHS, Value *RHS, Instruction &CxtI);
|
|
bool WillNotOverflowSignedMul(Value *LHS, Value *RHS, Instruction &CxtI);
|
|
Value *EmitGEPOffset(User *GEP);
|
|
Instruction *scalarizePHI(ExtractElementInst &EI, PHINode *PN);
|
|
Value *EvaluateInDifferentElementOrder(Value *V, ArrayRef<int> Mask);
|
|
Instruction *foldCastedBitwiseLogic(BinaryOperator &I);
|
|
Instruction *shrinkBitwiseLogic(TruncInst &Trunc);
|
|
Instruction *optimizeBitCastFromPhi(CastInst &CI, PHINode *PN);
|
|
|
|
/// Determine if a pair of casts can be replaced by a single cast.
|
|
///
|
|
/// \param CI1 The first of a pair of casts.
|
|
/// \param CI2 The second of a pair of casts.
|
|
///
|
|
/// \return 0 if the cast pair cannot be eliminated, otherwise returns an
|
|
/// Instruction::CastOps value for a cast that can replace the pair, casting
|
|
/// CI1->getSrcTy() to CI2->getDstTy().
|
|
///
|
|
/// \see CastInst::isEliminableCastPair
|
|
Instruction::CastOps isEliminableCastPair(const CastInst *CI1,
|
|
const CastInst *CI2);
|
|
|
|
public:
|
|
/// \brief Inserts an instruction \p New before instruction \p Old
|
|
///
|
|
/// Also adds the new instruction to the worklist and returns \p New so that
|
|
/// it is suitable for use as the return from the visitation patterns.
|
|
Instruction *InsertNewInstBefore(Instruction *New, Instruction &Old) {
|
|
assert(New && !New->getParent() &&
|
|
"New instruction already inserted into a basic block!");
|
|
BasicBlock *BB = Old.getParent();
|
|
BB->getInstList().insert(Old.getIterator(), New); // Insert inst
|
|
Worklist.Add(New);
|
|
return New;
|
|
}
|
|
|
|
/// \brief Same as InsertNewInstBefore, but also sets the debug loc.
|
|
Instruction *InsertNewInstWith(Instruction *New, Instruction &Old) {
|
|
New->setDebugLoc(Old.getDebugLoc());
|
|
return InsertNewInstBefore(New, Old);
|
|
}
|
|
|
|
/// \brief A combiner-aware RAUW-like routine.
|
|
///
|
|
/// This method is to be used when an instruction is found to be dead,
|
|
/// replaceable with another preexisting expression. Here we add all uses of
|
|
/// I to the worklist, replace all uses of I with the new value, then return
|
|
/// I, so that the inst combiner will know that I was modified.
|
|
Instruction *replaceInstUsesWith(Instruction &I, Value *V) {
|
|
// If there are no uses to replace, then we return nullptr to indicate that
|
|
// no changes were made to the program.
|
|
if (I.use_empty()) return nullptr;
|
|
|
|
Worklist.AddUsersToWorkList(I); // Add all modified instrs to worklist.
|
|
|
|
// If we are replacing the instruction with itself, this must be in a
|
|
// segment of unreachable code, so just clobber the instruction.
|
|
if (&I == V)
|
|
V = UndefValue::get(I.getType());
|
|
|
|
DEBUG(dbgs() << "IC: Replacing " << I << "\n"
|
|
<< " with " << *V << '\n');
|
|
|
|
I.replaceAllUsesWith(V);
|
|
return &I;
|
|
}
|
|
|
|
/// Creates a result tuple for an overflow intrinsic \p II with a given
|
|
/// \p Result and a constant \p Overflow value.
|
|
Instruction *CreateOverflowTuple(IntrinsicInst *II, Value *Result,
|
|
Constant *Overflow) {
|
|
Constant *V[] = {UndefValue::get(Result->getType()), Overflow};
|
|
StructType *ST = cast<StructType>(II->getType());
|
|
Constant *Struct = ConstantStruct::get(ST, V);
|
|
return InsertValueInst::Create(Struct, Result, 0);
|
|
}
|
|
|
|
/// \brief Combiner aware instruction erasure.
|
|
///
|
|
/// When dealing with an instruction that has side effects or produces a void
|
|
/// value, we can't rely on DCE to delete the instruction. Instead, visit
|
|
/// methods should return the value returned by this function.
|
|
Instruction *eraseInstFromFunction(Instruction &I) {
|
|
DEBUG(dbgs() << "IC: ERASE " << I << '\n');
|
|
|
|
assert(I.use_empty() && "Cannot erase instruction that is used!");
|
|
// Make sure that we reprocess all operands now that we reduced their
|
|
// use counts.
|
|
if (I.getNumOperands() < 8) {
|
|
for (Use &Operand : I.operands())
|
|
if (auto *Inst = dyn_cast<Instruction>(Operand))
|
|
Worklist.Add(Inst);
|
|
}
|
|
Worklist.Remove(&I);
|
|
I.eraseFromParent();
|
|
MadeIRChange = true;
|
|
return nullptr; // Don't do anything with FI
|
|
}
|
|
|
|
void computeKnownBits(Value *V, APInt &KnownZero, APInt &KnownOne,
|
|
unsigned Depth, Instruction *CxtI) const {
|
|
return llvm::computeKnownBits(V, KnownZero, KnownOne, DL, Depth, &AC, CxtI,
|
|
&DT);
|
|
}
|
|
|
|
bool MaskedValueIsZero(Value *V, const APInt &Mask, unsigned Depth = 0,
|
|
Instruction *CxtI = nullptr) const {
|
|
return llvm::MaskedValueIsZero(V, Mask, DL, Depth, &AC, CxtI, &DT);
|
|
}
|
|
unsigned ComputeNumSignBits(Value *Op, unsigned Depth = 0,
|
|
Instruction *CxtI = nullptr) const {
|
|
return llvm::ComputeNumSignBits(Op, DL, Depth, &AC, CxtI, &DT);
|
|
}
|
|
void ComputeSignBit(Value *V, bool &KnownZero, bool &KnownOne,
|
|
unsigned Depth = 0, Instruction *CxtI = nullptr) const {
|
|
return llvm::ComputeSignBit(V, KnownZero, KnownOne, DL, Depth, &AC, CxtI,
|
|
&DT);
|
|
}
|
|
OverflowResult computeOverflowForUnsignedMul(Value *LHS, Value *RHS,
|
|
const Instruction *CxtI) {
|
|
return llvm::computeOverflowForUnsignedMul(LHS, RHS, DL, &AC, CxtI, &DT);
|
|
}
|
|
OverflowResult computeOverflowForUnsignedAdd(Value *LHS, Value *RHS,
|
|
const Instruction *CxtI) {
|
|
return llvm::computeOverflowForUnsignedAdd(LHS, RHS, DL, &AC, CxtI, &DT);
|
|
}
|
|
|
|
private:
|
|
/// \brief Performs a few simplifications for operators which are associative
|
|
/// or commutative.
|
|
bool SimplifyAssociativeOrCommutative(BinaryOperator &I);
|
|
|
|
/// \brief Tries to simplify binary operations which some other binary
|
|
/// operation distributes over.
|
|
///
|
|
/// It does this by either by factorizing out common terms (eg "(A*B)+(A*C)"
|
|
/// -> "A*(B+C)") or expanding out if this results in simplifications (eg: "A
|
|
/// & (B | C) -> (A&B) | (A&C)" if this is a win). Returns the simplified
|
|
/// value, or null if it didn't simplify.
|
|
Value *SimplifyUsingDistributiveLaws(BinaryOperator &I);
|
|
|
|
/// \brief Attempts to replace V with a simpler value based on the demanded
|
|
/// bits.
|
|
Value *SimplifyDemandedUseBits(Value *V, APInt DemandedMask, APInt &KnownZero,
|
|
APInt &KnownOne, unsigned Depth,
|
|
Instruction *CxtI);
|
|
bool SimplifyDemandedBits(Use &U, const APInt &DemandedMask, APInt &KnownZero,
|
|
APInt &KnownOne, unsigned Depth = 0);
|
|
/// Helper routine of SimplifyDemandedUseBits. It tries to simplify demanded
|
|
/// bit for "r1 = shr x, c1; r2 = shl r1, c2" instruction sequence.
|
|
Value *SimplifyShrShlDemandedBits(Instruction *Lsr, Instruction *Sftl,
|
|
const APInt &DemandedMask, APInt &KnownZero,
|
|
APInt &KnownOne);
|
|
|
|
/// \brief Tries to simplify operands to an integer instruction based on its
|
|
/// demanded bits.
|
|
bool SimplifyDemandedInstructionBits(Instruction &Inst);
|
|
|
|
Value *SimplifyDemandedVectorElts(Value *V, APInt DemandedElts,
|
|
APInt &UndefElts, unsigned Depth = 0);
|
|
|
|
Value *SimplifyVectorOp(BinaryOperator &Inst);
|
|
Value *SimplifyBSwap(BinaryOperator &Inst);
|
|
|
|
|
|
/// Given a binary operator, cast instruction, or select which has a PHI node
|
|
/// as operand #0, see if we can fold the instruction into the PHI (which is
|
|
/// only possible if all operands to the PHI are constants).
|
|
Instruction *FoldOpIntoPhi(Instruction &I);
|
|
|
|
/// Given an instruction with a select as one operand and a constant as the
|
|
/// other operand, try to fold the binary operator into the select arguments.
|
|
/// This also works for Cast instructions, which obviously do not have a
|
|
/// second operand.
|
|
Instruction *FoldOpIntoSelect(Instruction &Op, SelectInst *SI);
|
|
|
|
/// This is a convenience wrapper function for the above two functions.
|
|
Instruction *foldOpWithConstantIntoOperand(Instruction &I);
|
|
|
|
/// \brief Try to rotate an operation below a PHI node, using PHI nodes for
|
|
/// its operands.
|
|
Instruction *FoldPHIArgOpIntoPHI(PHINode &PN);
|
|
Instruction *FoldPHIArgBinOpIntoPHI(PHINode &PN);
|
|
Instruction *FoldPHIArgGEPIntoPHI(PHINode &PN);
|
|
Instruction *FoldPHIArgLoadIntoPHI(PHINode &PN);
|
|
Instruction *FoldPHIArgZextsIntoPHI(PHINode &PN);
|
|
|
|
/// Helper function for FoldPHIArgXIntoPHI() to get debug location for the
|
|
/// folded operation.
|
|
DebugLoc PHIArgMergedDebugLoc(PHINode &PN);
|
|
|
|
Instruction *foldGEPICmp(GEPOperator *GEPLHS, Value *RHS,
|
|
ICmpInst::Predicate Cond, Instruction &I);
|
|
Instruction *foldAllocaCmp(ICmpInst &ICI, const AllocaInst *Alloca,
|
|
const Value *Other);
|
|
Instruction *foldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP,
|
|
GlobalVariable *GV, CmpInst &ICI,
|
|
ConstantInt *AndCst = nullptr);
|
|
Instruction *foldFCmpIntToFPConst(FCmpInst &I, Instruction *LHSI,
|
|
Constant *RHSC);
|
|
Instruction *foldICmpAddOpConst(Instruction &ICI, Value *X, ConstantInt *CI,
|
|
ICmpInst::Predicate Pred);
|
|
Instruction *foldICmpWithCastAndCast(ICmpInst &ICI);
|
|
|
|
Instruction *foldICmpUsingKnownBits(ICmpInst &Cmp);
|
|
Instruction *foldICmpWithConstant(ICmpInst &Cmp);
|
|
Instruction *foldICmpInstWithConstant(ICmpInst &Cmp);
|
|
Instruction *foldICmpInstWithConstantNotInt(ICmpInst &Cmp);
|
|
Instruction *foldICmpBinOp(ICmpInst &Cmp);
|
|
Instruction *foldICmpEquality(ICmpInst &Cmp);
|
|
|
|
Instruction *foldICmpTruncConstant(ICmpInst &Cmp, Instruction *Trunc,
|
|
const APInt *C);
|
|
Instruction *foldICmpAndConstant(ICmpInst &Cmp, BinaryOperator *And,
|
|
const APInt *C);
|
|
Instruction *foldICmpXorConstant(ICmpInst &Cmp, BinaryOperator *Xor,
|
|
const APInt *C);
|
|
Instruction *foldICmpOrConstant(ICmpInst &Cmp, BinaryOperator *Or,
|
|
const APInt *C);
|
|
Instruction *foldICmpMulConstant(ICmpInst &Cmp, BinaryOperator *Mul,
|
|
const APInt *C);
|
|
Instruction *foldICmpShlConstant(ICmpInst &Cmp, BinaryOperator *Shl,
|
|
const APInt *C);
|
|
Instruction *foldICmpShrConstant(ICmpInst &Cmp, BinaryOperator *Shr,
|
|
const APInt *C);
|
|
Instruction *foldICmpUDivConstant(ICmpInst &Cmp, BinaryOperator *UDiv,
|
|
const APInt *C);
|
|
Instruction *foldICmpDivConstant(ICmpInst &Cmp, BinaryOperator *Div,
|
|
const APInt *C);
|
|
Instruction *foldICmpSubConstant(ICmpInst &Cmp, BinaryOperator *Sub,
|
|
const APInt *C);
|
|
Instruction *foldICmpAddConstant(ICmpInst &Cmp, BinaryOperator *Add,
|
|
const APInt *C);
|
|
Instruction *foldICmpAndConstConst(ICmpInst &Cmp, BinaryOperator *And,
|
|
const APInt *C1);
|
|
Instruction *foldICmpAndShift(ICmpInst &Cmp, BinaryOperator *And,
|
|
const APInt *C1, const APInt *C2);
|
|
Instruction *foldICmpShrConstConst(ICmpInst &I, Value *ShAmt, const APInt &C1,
|
|
const APInt &C2);
|
|
Instruction *foldICmpShlConstConst(ICmpInst &I, Value *ShAmt, const APInt &C1,
|
|
const APInt &C2);
|
|
|
|
Instruction *foldICmpBinOpEqualityWithConstant(ICmpInst &Cmp,
|
|
BinaryOperator *BO,
|
|
const APInt *C);
|
|
Instruction *foldICmpIntrinsicWithConstant(ICmpInst &ICI, const APInt *C);
|
|
|
|
// Helpers of visitSelectInst().
|
|
Instruction *foldSelectExtConst(SelectInst &Sel);
|
|
Instruction *foldSelectOpOp(SelectInst &SI, Instruction *TI, Instruction *FI);
|
|
Instruction *foldSelectIntoOp(SelectInst &SI, Value *, Value *);
|
|
Instruction *foldSPFofSPF(Instruction *Inner, SelectPatternFlavor SPF1,
|
|
Value *A, Value *B, Instruction &Outer,
|
|
SelectPatternFlavor SPF2, Value *C);
|
|
Instruction *foldSelectInstWithICmp(SelectInst &SI, ICmpInst *ICI);
|
|
|
|
Instruction *OptAndOp(Instruction *Op, ConstantInt *OpRHS,
|
|
ConstantInt *AndRHS, BinaryOperator &TheAnd);
|
|
|
|
Value *FoldLogicalPlusAnd(Value *LHS, Value *RHS, ConstantInt *Mask,
|
|
bool isSub, Instruction &I);
|
|
Value *insertRangeTest(Value *V, const APInt &Lo, const APInt &Hi,
|
|
bool isSigned, bool Inside);
|
|
Instruction *PromoteCastOfAllocation(BitCastInst &CI, AllocaInst &AI);
|
|
Instruction *MatchBSwap(BinaryOperator &I);
|
|
bool SimplifyStoreAtEndOfBlock(StoreInst &SI);
|
|
Instruction *SimplifyMemTransfer(MemIntrinsic *MI);
|
|
Instruction *SimplifyMemSet(MemSetInst *MI);
|
|
|
|
Value *EvaluateInDifferentType(Value *V, Type *Ty, bool isSigned);
|
|
|
|
/// \brief Returns a value X such that Val = X * Scale, or null if none.
|
|
///
|
|
/// If the multiplication is known not to overflow then NoSignedWrap is set.
|
|
Value *Descale(Value *Val, APInt Scale, bool &NoSignedWrap);
|
|
};
|
|
|
|
} // end namespace llvm.
|
|
|
|
#undef DEBUG_TYPE
|
|
|
|
#endif
|