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Differential D145281 Diff 502287 llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp

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llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp

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Show First 20 Lines • Show All 4,096 Lines • ▼ Show 20 LinesgetKnownSign(Value *Op, Instruction *CxtI, const DataLayout &DL,
Value *X, *Y; Value *X, *Y;
if (match(Op, m_NSWSub(m_Value(X), m_Value(Y)))) if (match(Op, m_NSWSub(m_Value(X), m_Value(Y))))
return isImpliedByDomCondition(ICmpInst::ICMP_SLT, X, Y, CxtI, DL); return isImpliedByDomCondition(ICmpInst::ICMP_SLT, X, Y, CxtI, DL);
return isImpliedByDomCondition( return isImpliedByDomCondition(
ICmpInst::ICMP_SLT, Op, Constant::getNullValue(Op->getType()), CxtI, DL); ICmpInst::ICMP_SLT, Op, Constant::getNullValue(Op->getType()), CxtI, DL);
} }
static std::optional<bool> getKnownSign(Value *Op, Instruction *CxtI,
const DataLayout &DL,
AssumptionCache *AC,
const DominatorTree *DT) {
KnownBits Known;
return getKnownSign(Op, CxtI, DL, AC, DT, Known);
}
static Instruction *foldICmpOrXX(ICmpInst &I, const SimplifyQuery &Q, static Instruction *foldICmpOrXX(ICmpInst &I, const SimplifyQuery &Q,
InstCombinerImpl &IC) { InstCombinerImpl &IC) {
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1), *A; Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1), *A;
bool Op0IsOr = false; bool Op0IsOr = false;
if (match(Op0, m_c_Or(m_Specific(Op1), m_Value(A)))) if (match(Op0, m_c_Or(m_Specific(Op1), m_Value(A))))
Op0IsOr = true; Op0IsOr = true;
else if (!match(Op1, m_c_Or(m_Specific(Op0), m_Value(A)))) else if (!match(Op1, m_c_Or(m_Specific(Op0), m_Value(A))))
return nullptr; return nullptr;
Value *OrOp = Op0IsOr ? Op0 : Op1; Value *OrOp = Op0IsOr ? Op0 : Op1;
Value *X = Op0IsOr ? Op1 : Op0; Value *X = Op0IsOr ? Op1 : Op0;
const CmpInst::Predicate Pred = I.getPredicate(); const CmpInst::Predicate Pred = I.getPredicate();
// icmp (X | Y) u<= X --> (X | Y) == X // icmp (X | Y) u<= X --> (X | Y) == X
if (Op0IsOr ? Pred == ICmpInst::ICMP_ULE : Pred == ICmpInst::ICMP_UGE) if (Op0IsOr ? Pred == ICmpInst::ICMP_ULE : Pred == ICmpInst::ICMP_UGE)
return new ICmpInst(ICmpInst::ICMP_EQ, Op0, Op1); return new ICmpInst(ICmpInst::ICMP_EQ, Op0, Op1);
// icmp (X | Y) u> X --> (X | Y) != X // icmp (X | Y) u> X --> (X | Y) != X
else if (Op0IsOr ? Pred == ICmpInst::ICMP_UGT : Pred == ICmpInst::ICMP_ULT) else if (Op0IsOr ? Pred == ICmpInst::ICMP_UGT : Pred == ICmpInst::ICMP_ULT)
return new ICmpInst(ICmpInst::ICMP_NE, Op0, Op1); return new ICmpInst(ICmpInst::ICMP_NE, Op0, Op1);
// icmp (X | noundef Y) eq/ne X // icmp (X | noundef Y) eq/ne X
// if (X | noundef Y).hasOneUse() // if (X | noundef Y).hasOneUse()
// --> (X & noundef Y) eq/ne noundef Y // --> (X & noundef Y) eq/ne noundef Y
if (ICmpInst::isEquality(Pred) && OrOp->hasOneUse() && if (ICmpInst::isEquality(Pred) && OrOp->hasOneUse() &&
RKSimonUnsubmitted
Not Done
ReplyInline Actions

Maybe move this into the if() to reduce scope

if (auto KnownSign = getKnownSign(A, &I, Q.DL, Q.AC, Q.DT))
RKSimon: Maybe move this into the if() to reduce scope ``` if (auto KnownSign = getKnownSign(A, &I, Q.DL…
isGuaranteedNotToBeUndefOrPoison(A, Q.AC, Q.CxtI, Q.DT, isGuaranteedNotToBeUndefOrPoison(A, Q.AC, Q.CxtI, Q.DT,
/*Depth*/ 0)) /*Depth*/ 0))
return new ICmpInst(Pred, IC.Builder.CreateAnd(X, A), A); return new ICmpInst(Pred, IC.Builder.CreateAnd(X, A), A);
if (ICmpInst::isEquality(Pred) || ICmpInst::getSignedPredicate(Pred) != Pred)
return nullptr;
auto KnownSign = getKnownSign(A, &I, Q.DL, Q.AC, Q.DT);
if (KnownSign != std::nullopt) {
// icmp (X | MinInt) s> X --> false
// icmp (X | MinInt) s<= X --> true
// icmp (X | MinInt) s>= X --> X s< 0
// icmp (X | MinInt) s< X --> X s>= 0
if (*KnownSign /* true is Signed. */ &&
IC.isKnownToBeAPowerOfTwo(A, /*OrZero*/ true, 0, &I)) {
if (Op0IsOr && (Pred == ICmpInst::ICMP_SGT || Pred == ICmpInst::ICMP_SLE))
return IC.replaceInstUsesWith(
I, ConstantInt::get(I.getType(), Pred == ICmpInst::ICMP_SLE));
else if (!Op0IsOr &&
(Pred == ICmpInst::ICMP_SLT || Pred == ICmpInst::ICMP_SGE))
return IC.replaceInstUsesWith(
I, ConstantInt::get(I.getType(), Pred == ICmpInst::ICMP_SGE));
else if (Op0IsOr ? Pred == ICmpInst::ICMP_SGE
: Pred == ICmpInst::ICMP_SLE)
return new ICmpInst(ICmpInst::ICMP_SLT, X,
Constant::getNullValue(Op0->getType()));
else
return new ICmpInst(ICmpInst::ICMP_SGE, X,
Constant::getNullValue(Op0->getType()));
}
// icmp (X | Pos_Y) s> X --> (X | Pos_Y) != X
// icmp (X | Pos_Y) s<= X --> (X | Pos_Y) == X
else if (!*KnownSign) {
if (Op0IsOr ? Pred == ICmpInst::ICMP_SGT : Pred == ICmpInst::ICMP_SLT)
return new ICmpInst(ICmpInst::ICMP_NE, Op0, Op1);
else if (Op0IsOr ? Pred == ICmpInst::ICMP_SLE
: Pred == ICmpInst::ICMP_SGE)
return new ICmpInst(ICmpInst::ICMP_EQ, Op0, Op1);
}
}
return nullptr; return nullptr;
} }
static Instruction *foldICmpXorXX(ICmpInst &I, const SimplifyQuery &Q, static Instruction *foldICmpXorXX(ICmpInst &I, const SimplifyQuery &Q,
InstCombinerImpl &IC) { InstCombinerImpl &IC) {
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1), *A; Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1), *A;
bool Op0IsXor = false; bool Op0IsXor = false;
if (match(Op0, m_c_Xor(m_Specific(Op1), m_Value(A)))) if (match(Op0, m_c_Xor(m_Specific(Op1), m_Value(A))))
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