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factor simplification logic for AND and OR out to InstSimplify from instcombine.

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llvm-svn: 86635
This commit is contained in:
Chris Lattner 2009-11-10 00:55:12 +00:00
parent 93a4f29c67
commit 3730cf6fef
3 changed files with 197 additions and 112 deletions
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15
include/llvm/Analysis/InstructionSimplify.h
View File

@ -20,15 +20,26 @@ namespace llvm {
class Value;
class TargetData;
/// SimplifyAndInst - Given operands for an And, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyAndInst(Value *LHS, Value *RHS,
const TargetData *TD = 0);
/// SimplifyOrInst - Given operands for an Or, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyOrInst(Value *LHS, Value *RHS,
const TargetData *TD = 0);
/// SimplifyICmpInst - Given operands for an ICmpInst, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
const TargetData *TD = 0);
const TargetData *TD = 0);
/// SimplifyFCmpInst - Given operands for an FCmpInst, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
const TargetData *TD = 0);
const TargetData *TD = 0);
//=== Helper functions for higher up the class hierarchy.

175
lib/Analysis/InstructionSimplify.cpp
View File

@ -16,21 +16,133 @@
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Instructions.h"
#include "llvm/Support/PatternMatch.h"
using namespace llvm;
using namespace llvm::PatternMatch;
/// SimplifyBinOp - Given operands for a BinaryOperator, see if we can
/// SimplifyAndInst - Given operands for an And, see if we can
/// fold the result. If not, this returns null.
Value *llvm::SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
const TargetData *TD) {
if (Constant *CLHS = dyn_cast<Constant>(LHS))
if (Constant *CRHS = dyn_cast<Constant>(RHS)) {
Constant *COps[] = {CLHS, CRHS};
return ConstantFoldInstOperands(Opcode, LHS->getType(), COps, 2, TD);
}
Value *llvm::SimplifyAndInst(Value *Op0, Value *Op1,
const TargetData *TD) {
if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
Constant *Ops[] = { CLHS, CRHS };
return ConstantFoldInstOperands(Instruction::And, CLHS->getType(),
Ops, 2, TD);
}
// Canonicalize the constant to the RHS.
std::swap(Op0, Op1);
}
// X & undef -> 0
if (isa<UndefValue>(Op1))
return Constant::getNullValue(Op0->getType());
// X & X = X
if (Op0 == Op1)
return Op0;
// X & <0,0> = <0,0>
if (isa<ConstantAggregateZero>(Op1))
return Op1;
// X & <-1,-1> = X
if (ConstantVector *CP = dyn_cast<ConstantVector>(Op1))
if (CP->isAllOnesValue())
return Op0;
if (ConstantInt *Op1CI = dyn_cast<ConstantInt>(Op1)) {
// X & 0 = 0
if (Op1CI->isZero())
return Op1CI;
// X & -1 = X
if (Op1CI->isAllOnesValue())
return Op0;
}
// A & ~A = ~A & A = 0
Value *A, *B;
if ((match(Op0, m_Not(m_Value(A))) && A == Op1) ||
(match(Op1, m_Not(m_Value(A))) && A == Op0))
return Constant::getNullValue(Op0->getType());
// (A | ?) & A = A
if (match(Op0, m_Or(m_Value(A), m_Value(B))) &&
(A == Op1 || B == Op1))
return Op1;
// A & (A | ?) = A
if (match(Op1, m_Or(m_Value(A), m_Value(B))) &&
(A == Op0 || B == Op0))
return Op0;
return 0;
}
/// SimplifyOrInst - Given operands for an Or, see if we can
/// fold the result. If not, this returns null.
Value *llvm::SimplifyOrInst(Value *Op0, Value *Op1,
const TargetData *TD) {
if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
Constant *Ops[] = { CLHS, CRHS };
return ConstantFoldInstOperands(Instruction::Or, CLHS->getType(),
Ops, 2, TD);
}
// Canonicalize the constant to the RHS.
std::swap(Op0, Op1);
}
// X | undef -> -1
if (isa<UndefValue>(Op1))
return Constant::getAllOnesValue(Op0->getType());
// X | X = X
if (Op0 == Op1)
return Op0;
// X | <0,0> = X
if (isa<ConstantAggregateZero>(Op1))
return Op0;
// X | <-1,-1> = <-1,-1>
if (ConstantVector *CP = dyn_cast<ConstantVector>(Op1))
if (CP->isAllOnesValue())
return Op1;
if (ConstantInt *Op1CI = dyn_cast<ConstantInt>(Op1)) {
// X | 0 = X
if (Op1CI->isZero())
return Op0;
// X | -1 = -1
if (Op1CI->isAllOnesValue())
return Op1CI;
}
// A | ~A = ~A | A = -1
Value *A, *B;
if ((match(Op0, m_Not(m_Value(A))) && A == Op1) ||
(match(Op1, m_Not(m_Value(A))) && A == Op0))
return Constant::getAllOnesValue(Op0->getType());
// (A & ?) | A = A
if (match(Op0, m_And(m_Value(A), m_Value(B))) &&
(A == Op1 || B == Op1))
return Op1;
// A | (A & ?) = A
if (match(Op1, m_And(m_Value(A), m_Value(B))) &&
(A == Op0 || B == Op0))
return Op0;
return 0;
}
static const Type *GetCompareTy(Value *Op) {
return CmpInst::makeCmpResultType(Op->getType());
}
@ -43,9 +155,14 @@ Value *llvm::SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate;
assert(CmpInst::isIntPredicate(Pred) && "Not an integer compare!");
if (Constant *CLHS = dyn_cast<Constant>(LHS))
if (Constant *CLHS = dyn_cast<Constant>(LHS)) {
if (Constant *CRHS = dyn_cast<Constant>(RHS))
return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, TD);
// If we have a constant, make sure it is on the RHS.
std::swap(LHS, RHS);
Pred = CmpInst::getSwappedPredicate(Pred);
}
// ITy - This is the return type of the compare we're considering.
const Type *ITy = GetCompareTy(LHS);
@ -54,12 +171,6 @@ Value *llvm::SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
if (LHS == RHS)
return ConstantInt::get(ITy, CmpInst::isTrueWhenEqual(Pred));
// If we have a constant, make sure it is on the RHS.
if (isa<Constant>(LHS)) {
std::swap(LHS, RHS);
Pred = CmpInst::getSwappedPredicate(Pred);
}
if (isa<UndefValue>(RHS)) // X icmp undef -> undef
return UndefValue::get(ITy);
@ -95,8 +206,6 @@ Value *llvm::SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
return ConstantInt::getTrue(CI->getContext());
break;
}
}
@ -110,9 +219,14 @@ Value *llvm::SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate;
assert(CmpInst::isFPPredicate(Pred) && "Not an FP compare!");
if (Constant *CLHS = dyn_cast<Constant>(LHS))
if (Constant *CLHS = dyn_cast<Constant>(LHS)) {
if (Constant *CRHS = dyn_cast<Constant>(RHS))
return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, TD);
// If we have a constant, make sure it is on the RHS.
std::swap(LHS, RHS);
Pred = CmpInst::getSwappedPredicate(Pred);
}
// Fold trivial predicates.
if (Pred == FCmpInst::FCMP_FALSE)
@ -120,12 +234,6 @@ Value *llvm::SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
if (Pred == FCmpInst::FCMP_TRUE)
return ConstantInt::get(GetCompareTy(LHS), 1);
// If we have a constant, make sure it is on the RHS.
if (isa<Constant>(LHS)) {
std::swap(LHS, RHS);
Pred = CmpInst::getSwappedPredicate(Pred);
}
if (isa<UndefValue>(RHS)) // fcmp pred X, undef -> undef
return UndefValue::get(GetCompareTy(LHS));
@ -155,7 +263,24 @@ Value *llvm::SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
return 0;
}
//=== Helper functions for higher up the class hierarchy.
/// SimplifyBinOp - Given operands for a BinaryOperator, see if we can
/// fold the result. If not, this returns null.
Value *llvm::SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
const TargetData *TD) {
switch (Opcode) {
case Instruction::And: return SimplifyAndInst(LHS, RHS, TD);
case Instruction::Or: return SimplifyOrInst(LHS, RHS, TD);
default:
if (Constant *CLHS = dyn_cast<Constant>(LHS))
if (Constant *CRHS = dyn_cast<Constant>(RHS)) {
Constant *COps[] = {CLHS, CRHS};
return ConstantFoldInstOperands(Opcode, LHS->getType(), COps, 2, TD);
}
return 0;
}
}
/// SimplifyCmpInst - Given operands for a CmpInst, see if we can
/// fold the result.

119
lib/Transforms/Scalar/InstructionCombining.cpp
View File

@ -4292,25 +4292,15 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
bool Changed = SimplifyCommutative(I);
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
if (isa<UndefValue>(Op1)) // X & undef -> 0
return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
// and X, X = X
if (Op0 == Op1)
return ReplaceInstUsesWith(I, Op1);
if (Value *V = SimplifyAndInst(Op0, Op1, TD))
return ReplaceInstUsesWith(I, V);
// See if we can simplify any instructions used by the instruction whose sole
// purpose is to compute bits we don't care about.
if (SimplifyDemandedInstructionBits(I))
return &I;
if (isa<VectorType>(I.getType())) {
if (ConstantVector *CP = dyn_cast<ConstantVector>(Op1)) {
if (CP->isAllOnesValue()) // X & <-1,-1> -> X
return ReplaceInstUsesWith(I, I.getOperand(0));
} else if (isa<ConstantAggregateZero>(Op1)) {
return ReplaceInstUsesWith(I, Op1); // X & <0,0> -> <0,0>
}
}
if (ConstantInt *AndRHS = dyn_cast<ConstantInt>(Op1)) {
const APInt &AndRHSMask = AndRHS->getValue();
@ -4431,42 +4421,29 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
return NV;
}
Value *Op0NotVal = dyn_castNotVal(Op0);
Value *Op1NotVal = dyn_castNotVal(Op1);
if (Op0NotVal == Op1 || Op1NotVal == Op0) // A & ~A == ~A & A == 0
return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
// (~A & ~B) == (~(A | B)) - De Morgan's Law
if (Op0NotVal && Op1NotVal && isOnlyUse(Op0) && isOnlyUse(Op1)) {
Value *Or = Builder->CreateOr(Op0NotVal, Op1NotVal,
I.getName()+".demorgan");
return BinaryOperator::CreateNot(Or);
}
if (Value *Op0NotVal = dyn_castNotVal(Op0))
if (Value *Op1NotVal = dyn_castNotVal(Op1))
if (Op0->hasOneUse() && Op1->hasOneUse()) {
Value *Or = Builder->CreateOr(Op0NotVal, Op1NotVal,
I.getName()+".demorgan");
return BinaryOperator::CreateNot(Or);
}
{
Value *A = 0, *B = 0, *C = 0, *D = 0;
if (match(Op0, m_Or(m_Value(A), m_Value(B)))) {
if (A == Op1 || B == Op1) // (A | ?) & A --> A
return ReplaceInstUsesWith(I, Op1);
// (A|B) & ~(A&B) -> A^B
if (match(Op0, m_Or(m_Value(A), m_Value(B))) &&
match(Op1, m_Not(m_And(m_Value(C), m_Value(D)))) &&
((A == C && B == D) || (A == D && B == C)))
return BinaryOperator::CreateXor(A, B);
// (A|B) & ~(A&B) -> A^B
if (match(Op1, m_Not(m_And(m_Value(C), m_Value(D))))) {
if ((A == C && B == D) || (A == D && B == C))
return BinaryOperator::CreateXor(A, B);
}
}
if (match(Op1, m_Or(m_Value(A), m_Value(B)))) {
if (A == Op0 || B == Op0) // A & (A | ?) --> A
return ReplaceInstUsesWith(I, Op0);
// ~(A&B) & (A|B) -> A^B
if (match(Op0, m_Not(m_And(m_Value(C), m_Value(D))))) {
if ((A == C && B == D) || (A == D && B == C))
return BinaryOperator::CreateXor(A, B);
}
}
// ~(A&B) & (A|B) -> A^B
if (match(Op1, m_Or(m_Value(A), m_Value(B))) &&
match(Op0, m_Not(m_And(m_Value(C), m_Value(D)))) &&
((A == C && B == D) || (A == D && B == C)))
return BinaryOperator::CreateXor(A, B);
if (Op0->hasOneUse() &&
match(Op0, m_Xor(m_Value(A), m_Value(B)))) {
@ -4998,27 +4975,15 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
bool Changed = SimplifyCommutative(I);
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
if (isa<UndefValue>(Op1)) // X | undef -> -1
return ReplaceInstUsesWith(I, Constant::getAllOnesValue(I.getType()));
// or X, X = X
if (Op0 == Op1)
return ReplaceInstUsesWith(I, Op0);
if (Value *V = SimplifyOrInst(Op0, Op1, TD))
return ReplaceInstUsesWith(I, V);
// See if we can simplify any instructions used by the instruction whose sole
// purpose is to compute bits we don't care about.
if (SimplifyDemandedInstructionBits(I))
return &I;
if (isa<VectorType>(I.getType())) {
if (isa<ConstantAggregateZero>(Op1)) {
return ReplaceInstUsesWith(I, Op0); // X | <0,0> -> X
} else if (ConstantVector *CP = dyn_cast<ConstantVector>(Op1)) {
if (CP->isAllOnesValue()) // X | <-1,-1> -> <-1,-1>
return ReplaceInstUsesWith(I, I.getOperand(1));
}
}
// or X, -1 == -1
if (ConstantInt *RHS = dyn_cast<ConstantInt>(Op1)) {
ConstantInt *C1 = 0; Value *X = 0;
// (X & C1) | C2 --> (X | C2) & (C1|C2)
@ -5051,13 +5016,6 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
Value *A = 0, *B = 0;
ConstantInt *C1 = 0, *C2 = 0;
if (match(Op0, m_And(m_Value(A), m_Value(B))))
if (A == Op1 || B == Op1) // (A & ?) | A --> A
return ReplaceInstUsesWith(I, Op1);
if (match(Op1, m_And(m_Value(A), m_Value(B))))
if (A == Op0 || B == Op0) // A | (A & ?) --> A
return ReplaceInstUsesWith(I, Op0);
// (A | B) | C and A | (B | C) -> bswap if possible.
// (A >> B) | (C << D) and (A << B) | (B >> C) -> bswap if possible.
if (match(Op0, m_Or(m_Value(), m_Value())) ||
@ -5191,23 +5149,14 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
if (Ret) return Ret;
}
if ((A = dyn_castNotVal(Op0))) { // ~A | Op1
if (A == Op1) // ~A | A == -1
return ReplaceInstUsesWith(I, Constant::getAllOnesValue(I.getType()));
} else {
A = 0;
}
// Note, A is still live here!
if ((B = dyn_castNotVal(Op1))) { // Op0 | ~B
if (Op0 == B)
return ReplaceInstUsesWith(I, Constant::getAllOnesValue(I.getType()));
// (~A | ~B) == (~(A & B)) - De Morgan's Law
if (A && isOnlyUse(Op0) && isOnlyUse(Op1)) {
Value *And = Builder->CreateAnd(A, B, I.getName()+".demorgan");
return BinaryOperator::CreateNot(And);
}
}
// (~A | ~B) == (~(A & B)) - De Morgan's Law
if (Value *Op0NotVal = dyn_castNotVal(Op0))
if (Value *Op1NotVal = dyn_castNotVal(Op1))
if (Op0->hasOneUse() && Op1->hasOneUse()) {
Value *And = Builder->CreateAnd(Op0NotVal, Op1NotVal,
I.getName()+".demorgan");
return BinaryOperator::CreateNot(And);
}
// (icmp1 A, B) | (icmp2 A, B) --> (icmp3 A, B)
if (ICmpInst *RHS = dyn_cast<ICmpInst>(I.getOperand(1))) {