mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-23 15:29:51 +00:00
089a246333
effective in avoiding recomputation of LCSSA form; the widespread use of instsimplify (which looks through phi nodes) means it was not preserving LCSSA form anyway; and instcombine is no longer scheduled in the middle of the loop passes so this doesn't matter anymore. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130301 91177308-0d34-0410-b5e6-96231b3b80d8
360 lines
15 KiB
C++
360 lines
15 KiB
C++
//===- InstCombine.h - Main InstCombine pass definition -------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef INSTCOMBINE_INSTCOMBINE_H
|
|
#define INSTCOMBINE_INSTCOMBINE_H
|
|
|
|
#include "InstCombineWorklist.h"
|
|
#include "llvm/Operator.h"
|
|
#include "llvm/Pass.h"
|
|
#include "llvm/Analysis/ValueTracking.h"
|
|
#include "llvm/Support/IRBuilder.h"
|
|
#include "llvm/Support/InstVisitor.h"
|
|
#include "llvm/Support/TargetFolder.h"
|
|
|
|
namespace llvm {
|
|
class CallSite;
|
|
class TargetData;
|
|
class DbgDeclareInst;
|
|
class MemIntrinsic;
|
|
class MemSetInst;
|
|
|
|
/// SelectPatternFlavor - We can match a variety of different patterns for
|
|
/// select operations.
|
|
enum SelectPatternFlavor {
|
|
SPF_UNKNOWN = 0,
|
|
SPF_SMIN, SPF_UMIN,
|
|
SPF_SMAX, SPF_UMAX
|
|
//SPF_ABS - TODO.
|
|
};
|
|
|
|
/// getComplexity: Assign a complexity or rank value to LLVM Values...
|
|
/// 0 -> undef, 1 -> Const, 2 -> Other, 3 -> Arg, 3 -> Unary, 4 -> OtherInst
|
|
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;
|
|
}
|
|
|
|
|
|
/// InstCombineIRInserter - This is an IRBuilder insertion helper that works
|
|
/// just like the normal insertion helper, but also adds any new instructions
|
|
/// to the instcombine worklist.
|
|
class LLVM_LIBRARY_VISIBILITY InstCombineIRInserter
|
|
: public IRBuilderDefaultInserter<true> {
|
|
InstCombineWorklist &Worklist;
|
|
public:
|
|
InstCombineIRInserter(InstCombineWorklist &WL) : Worklist(WL) {}
|
|
|
|
void InsertHelper(Instruction *I, const Twine &Name,
|
|
BasicBlock *BB, BasicBlock::iterator InsertPt) const {
|
|
IRBuilderDefaultInserter<true>::InsertHelper(I, Name, BB, InsertPt);
|
|
Worklist.Add(I);
|
|
}
|
|
};
|
|
|
|
/// InstCombiner - The -instcombine pass.
|
|
class LLVM_LIBRARY_VISIBILITY InstCombiner
|
|
: public FunctionPass,
|
|
public InstVisitor<InstCombiner, Instruction*> {
|
|
TargetData *TD;
|
|
bool MadeIRChange;
|
|
public:
|
|
/// Worklist - All of the instructions that need to be simplified.
|
|
InstCombineWorklist Worklist;
|
|
|
|
/// Builder - This is an IRBuilder that automatically inserts new
|
|
/// instructions into the worklist when they are created.
|
|
typedef IRBuilder<true, TargetFolder, InstCombineIRInserter> BuilderTy;
|
|
BuilderTy *Builder;
|
|
|
|
static char ID; // Pass identification, replacement for typeid
|
|
InstCombiner() : FunctionPass(ID), TD(0), Builder(0) {
|
|
initializeInstCombinerPass(*PassRegistry::getPassRegistry());
|
|
}
|
|
|
|
public:
|
|
virtual bool runOnFunction(Function &F);
|
|
|
|
bool DoOneIteration(Function &F, unsigned ItNum);
|
|
|
|
virtual void getAnalysisUsage(AnalysisUsage &AU) const;
|
|
|
|
TargetData *getTargetData() const { return TD; }
|
|
|
|
// 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, const Type *Ty);
|
|
Instruction *visitSub(BinaryOperator &I);
|
|
Instruction *visitFSub(BinaryOperator &I);
|
|
Instruction *visitMul(BinaryOperator &I);
|
|
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 *FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS);
|
|
Value *FoldAndOfFCmps(FCmpInst *LHS, FCmpInst *RHS);
|
|
Instruction *visitAnd(BinaryOperator &I);
|
|
Value *FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS);
|
|
Value *FoldOrOfFCmps(FCmpInst *LHS, FCmpInst *RHS);
|
|
Instruction *FoldOrWithConstants(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 *FoldFCmp_IntToFP_Cst(FCmpInst &I, Instruction *LHSI,
|
|
Constant *RHSC);
|
|
Instruction *FoldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP,
|
|
GlobalVariable *GV, CmpInst &ICI,
|
|
ConstantInt *AndCst = 0);
|
|
Instruction *visitFCmpInst(FCmpInst &I);
|
|
Instruction *visitICmpInst(ICmpInst &I);
|
|
Instruction *visitICmpInstWithCastAndCast(ICmpInst &ICI);
|
|
Instruction *visitICmpInstWithInstAndIntCst(ICmpInst &ICI,
|
|
Instruction *LHS,
|
|
ConstantInt *RHS);
|
|
Instruction *FoldICmpDivCst(ICmpInst &ICI, BinaryOperator *DivI,
|
|
ConstantInt *DivRHS);
|
|
Instruction *FoldICmpShrCst(ICmpInst &ICI, BinaryOperator *DivI,
|
|
ConstantInt *DivRHS);
|
|
Instruction *FoldICmpAddOpCst(ICmpInst &ICI, Value *X, ConstantInt *CI,
|
|
ICmpInst::Predicate Pred, Value *TheAdd);
|
|
Instruction *FoldGEPICmp(GEPOperator *GEPLHS, Value *RHS,
|
|
ICmpInst::Predicate Cond, Instruction &I);
|
|
Instruction *FoldShiftByConstant(Value *Op0, ConstantInt *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 *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 *visitSelectInst(SelectInst &SI);
|
|
Instruction *visitSelectInstWithICmp(SelectInst &SI, ICmpInst *ICI);
|
|
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 *visitMalloc(Instruction &FI);
|
|
Instruction *visitFree(CallInst &FI);
|
|
Instruction *visitLoadInst(LoadInst &LI);
|
|
Instruction *visitStoreInst(StoreInst &SI);
|
|
Instruction *visitBranchInst(BranchInst &BI);
|
|
Instruction *visitSwitchInst(SwitchInst &SI);
|
|
Instruction *visitInsertElementInst(InsertElementInst &IE);
|
|
Instruction *visitExtractElementInst(ExtractElementInst &EI);
|
|
Instruction *visitShuffleVectorInst(ShuffleVectorInst &SVI);
|
|
Instruction *visitExtractValueInst(ExtractValueInst &EV);
|
|
|
|
// visitInstruction - Specify what to return for unhandled instructions...
|
|
Instruction *visitInstruction(Instruction &I) { return 0; }
|
|
|
|
private:
|
|
bool ShouldChangeType(const Type *From, const Type *To) const;
|
|
Value *dyn_castNegVal(Value *V) const;
|
|
Value *dyn_castFNegVal(Value *V) const;
|
|
const Type *FindElementAtOffset(const Type *Ty, int64_t Offset,
|
|
SmallVectorImpl<Value*> &NewIndices);
|
|
Instruction *FoldOpIntoSelect(Instruction &Op, SelectInst *SI);
|
|
|
|
/// ShouldOptimizeCast - Return true if the cast from "V to Ty" actually
|
|
/// results in any code being generated and is interesting to optimize out. If
|
|
/// the cast can be eliminated by some other simple transformation, we prefer
|
|
/// to do the simplification first.
|
|
bool ShouldOptimizeCast(Instruction::CastOps opcode,const Value *V,
|
|
const Type *Ty);
|
|
|
|
Instruction *visitCallSite(CallSite CS);
|
|
Instruction *tryOptimizeCall(CallInst *CI, const TargetData *TD);
|
|
bool transformConstExprCastCall(CallSite CS);
|
|
Instruction *transformCallThroughTrampoline(CallSite CS);
|
|
Instruction *transformZExtICmp(ICmpInst *ICI, Instruction &CI,
|
|
bool DoXform = true);
|
|
Instruction *transformSExtICmp(ICmpInst *ICI, Instruction &CI);
|
|
bool WillNotOverflowSignedAdd(Value *LHS, Value *RHS);
|
|
Value *EmitGEPOffset(User *GEP);
|
|
|
|
public:
|
|
// InsertNewInstBefore - insert an instruction New before instruction Old
|
|
// in the program. Add the new instruction to the worklist.
|
|
//
|
|
Instruction *InsertNewInstBefore(Instruction *New, Instruction &Old) {
|
|
assert(New && New->getParent() == 0 &&
|
|
"New instruction already inserted into a basic block!");
|
|
BasicBlock *BB = Old.getParent();
|
|
BB->getInstList().insert(&Old, New); // Insert inst
|
|
Worklist.Add(New);
|
|
return New;
|
|
}
|
|
|
|
// ReplaceInstUsesWith - This method is to be used when an instruction is
|
|
// found to be dead, replacable 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) {
|
|
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(errs() << "IC: Replacing " << I << "\n"
|
|
" with " << *V << '\n');
|
|
|
|
I.replaceAllUsesWith(V);
|
|
return &I;
|
|
}
|
|
|
|
// EraseInstFromFunction - 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(errs() << "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 (User::op_iterator i = I.op_begin(), e = I.op_end(); i != e; ++i)
|
|
if (Instruction *Op = dyn_cast<Instruction>(*i))
|
|
Worklist.Add(Op);
|
|
}
|
|
Worklist.Remove(&I);
|
|
I.eraseFromParent();
|
|
MadeIRChange = true;
|
|
return 0; // Don't do anything with FI
|
|
}
|
|
|
|
void ComputeMaskedBits(Value *V, const APInt &Mask, APInt &KnownZero,
|
|
APInt &KnownOne, unsigned Depth = 0) const {
|
|
return llvm::ComputeMaskedBits(V, Mask, KnownZero, KnownOne, TD, Depth);
|
|
}
|
|
|
|
bool MaskedValueIsZero(Value *V, const APInt &Mask,
|
|
unsigned Depth = 0) const {
|
|
return llvm::MaskedValueIsZero(V, Mask, TD, Depth);
|
|
}
|
|
unsigned ComputeNumSignBits(Value *Op, unsigned Depth = 0) const {
|
|
return llvm::ComputeNumSignBits(Op, TD, Depth);
|
|
}
|
|
|
|
private:
|
|
|
|
/// SimplifyAssociativeOrCommutative - This performs a few simplifications for
|
|
/// operators which are associative or commutative.
|
|
bool SimplifyAssociativeOrCommutative(BinaryOperator &I);
|
|
|
|
/// SimplifyUsingDistributiveLaws - This tries to simplify binary operations
|
|
/// which some other binary operation distributes over 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);
|
|
|
|
/// SimplifyDemandedUseBits - 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);
|
|
bool SimplifyDemandedBits(Use &U, APInt DemandedMask,
|
|
APInt& KnownZero, APInt& KnownOne,
|
|
unsigned Depth=0);
|
|
|
|
/// SimplifyDemandedInstructionBits - Inst is an integer instruction that
|
|
/// SimplifyDemandedBits knows about. See if the instruction has any
|
|
/// properties that allow us to simplify its operands.
|
|
bool SimplifyDemandedInstructionBits(Instruction &Inst);
|
|
|
|
Value *SimplifyDemandedVectorElts(Value *V, APInt DemandedElts,
|
|
APInt& UndefElts, unsigned Depth = 0);
|
|
|
|
// FoldOpIntoPhi - 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);
|
|
|
|
// FoldPHIArgOpIntoPHI - If all operands to a PHI node are the same "unary"
|
|
// operator and they all are only used by the PHI, PHI together their
|
|
// inputs, and do the operation once, to the result of the PHI.
|
|
Instruction *FoldPHIArgOpIntoPHI(PHINode &PN);
|
|
Instruction *FoldPHIArgBinOpIntoPHI(PHINode &PN);
|
|
Instruction *FoldPHIArgGEPIntoPHI(PHINode &PN);
|
|
Instruction *FoldPHIArgLoadIntoPHI(PHINode &PN);
|
|
|
|
|
|
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, Constant *Lo, Constant *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, const Type *Ty, bool isSigned);
|
|
};
|
|
|
|
|
|
|
|
} // end namespace llvm.
|
|
|
|
#endif
|