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Differential D112509 Diff 382390 llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp

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llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp

Show First 20 Lines • Show All 2,922 Lines • ▼ Show 20 Lines if ((Cmp0 == TrueVal && Cmp1 == FalseVal) ||
} }
// NOTE: if we wanted to, this is where to detect MIN/MAX // NOTE: if we wanted to, this is where to detect MIN/MAX
} }
} }
// Canonicalize select with fcmp to fabs(). -0.0 makes this tricky. We need // Canonicalize select with fcmp to fabs(). -0.0 makes this tricky. We need
// fast-math-flags (nsz) or fsub with +0.0 (not fneg) for this to work. // fast-math-flags (nsz) or fsub with +0.0 (not fneg) for this to work.
// (X <= +/-0.0) ? (0.0 - X) : X --> fabs(X) // (X <= +/-0.0) ? (0.0 - X) : X --> fabs(X)
if (match(CondVal, m_FCmp(Pred, m_Specific(FalseVal), m_AnyZeroFP())) && if (match(CondVal, m_FCmp(Pred, m_Specific(FalseVal), m_AnyZeroFP())) &&
spatelUnsubmitted
Done
ReplyInline Actions

Can we remove this match as a preliminary cleanup?

spatel: Can we remove this match as a preliminary cleanup?
match(TrueVal, m_FSub(m_PosZeroFP(), m_Specific(FalseVal))) && match(TrueVal, m_FSub(m_PosZeroFP(), m_Specific(FalseVal))) &&
(Pred == FCmpInst::FCMP_OLE || Pred == FCmpInst::FCMP_ULE)) { (Pred == FCmpInst::FCMP_OLE || Pred == FCmpInst::FCMP_ULE)) {
Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, FalseVal, &SI); Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, FalseVal, &SI);
return replaceInstUsesWith(SI, Fabs); return replaceInstUsesWith(SI, Fabs);
} }
// (X > +/-0.0) ? X : (0.0 - X) --> fabs(X) // (X > +/-0.0) ? X : (0.0 - X) --> fabs(X)
if (match(CondVal, m_FCmp(Pred, m_Specific(TrueVal), m_AnyZeroFP())) && if (match(CondVal, m_FCmp(Pred, m_Specific(TrueVal), m_AnyZeroFP())) &&
match(FalseVal, m_FSub(m_PosZeroFP(), m_Specific(TrueVal))) && match(FalseVal, m_FSub(m_PosZeroFP(), m_Specific(TrueVal))) &&
(Pred == FCmpInst::FCMP_OGT || Pred == FCmpInst::FCMP_UGT)) { (Pred == FCmpInst::FCMP_OGT || Pred == FCmpInst::FCMP_UGT)) {
Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, TrueVal, &SI); Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, TrueVal, &SI);
return replaceInstUsesWith(SI, Fabs); return replaceInstUsesWith(SI, Fabs);
} }
// With nnan and nsz: // (X < +/-0.0) ? X : (0.0 - X) --> (0.0 - fabs(X))
// With nsz:
// (X < +/-0.0) ? X : -X --> -fabs(X)
if (match(CondVal, m_FCmp(Pred, m_Specific(TrueVal), m_AnyZeroFP())) &&
(match(FalseVal, m_FSub(m_PosZeroFP(), m_Specific(TrueVal))) ||
(match(FalseVal, m_FNeg(m_Specific(TrueVal))) &&
cast<Instruction>(FalseVal)->hasNoSignedZeros())) &&
(Pred == FCmpInst::FCMP_OLT || Pred == FCmpInst::FCMP_ULT)) {
Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, TrueVal, &SI);
return BinaryOperator::CreateFSubFMF(ConstantFP::get(Fabs->getType(), 0.0),
Fabs, cast<Instruction>(FalseVal));
}
// With nsz:
// (X < +/-0.0) ? -X : X --> fabs(X) // (X < +/-0.0) ? -X : X --> fabs(X)
// (X <= +/-0.0) ? -X : X --> fabs(X) // (X <= +/-0.0) ? -X : X --> fabs(X)
if (match(CondVal, m_FCmp(Pred, m_Specific(FalseVal), m_AnyZeroFP())) && if (match(CondVal, m_FCmp(Pred, m_Specific(FalseVal), m_AnyZeroFP())) &&
spatelUnsubmitted
Done
ReplyInline Actions

Can we remove this match as a preliminary cleanup?

spatel: Can we remove this match as a preliminary cleanup?
match(TrueVal, m_FNeg(m_Specific(FalseVal))) && SI.hasNoSignedZeros() && match(TrueVal, m_FNeg(m_Specific(FalseVal))) && SI.hasNoSignedZeros() &&
(Pred == FCmpInst::FCMP_OLT || Pred == FCmpInst::FCMP_OLE || (Pred == FCmpInst::FCMP_OLT || Pred == FCmpInst::FCMP_OLE ||
Pred == FCmpInst::FCMP_ULT || Pred == FCmpInst::FCMP_ULE)) { Pred == FCmpInst::FCMP_ULT || Pred == FCmpInst::FCMP_ULE)) {
Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, FalseVal, &SI); Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, FalseVal, &SI);
return replaceInstUsesWith(SI, Fabs); return replaceInstUsesWith(SI, Fabs);
} }
// With nnan and nsz: // With nsz:
// (X > +/-0.0) ? X : -X --> fabs(X) // (X > +/-0.0) ? X : -X --> fabs(X)
// (X >= +/-0.0) ? X : -X --> fabs(X) // (X >= +/-0.0) ? X : -X --> fabs(X)
if (match(CondVal, m_FCmp(Pred, m_Specific(TrueVal), m_AnyZeroFP())) && if (match(CondVal, m_FCmp(Pred, m_Specific(TrueVal), m_AnyZeroFP())) &&
match(FalseVal, m_FNeg(m_Specific(TrueVal))) && SI.hasNoSignedZeros() && match(FalseVal, m_FNeg(m_Specific(TrueVal))) && SI.hasNoSignedZeros() &&
(Pred == FCmpInst::FCMP_OGT || Pred == FCmpInst::FCMP_OGE || (Pred == FCmpInst::FCMP_OGT || Pred == FCmpInst::FCMP_OGE ||
Pred == FCmpInst::FCMP_UGT || Pred == FCmpInst::FCMP_UGE)) { Pred == FCmpInst::FCMP_UGT || Pred == FCmpInst::FCMP_UGE)) {
Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, TrueVal, &SI); Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, TrueVal, &SI);
return replaceInstUsesWith(SI, Fabs); return replaceInstUsesWith(SI, Fabs);
} }
// With nsz:
// (X < +/-0.0) ? X : -X --> -fabs(X)
// (X <= +/-0.0) ? X : -X --> -fabs(X)
if (match(CondVal, m_FCmp(Pred, m_Specific(TrueVal), m_AnyZeroFP())) &&
match(FalseVal, m_FNeg(m_Specific(TrueVal))) && SI.hasNoSignedZeros() &&
(Pred == FCmpInst::FCMP_OLT || Pred == FCmpInst::FCMP_OLE ||
Pred == FCmpInst::FCMP_ULT || Pred == FCmpInst::FCMP_ULE)) {
Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, TrueVal, &SI);
return UnaryOperator::CreateFNegFMF(Fabs, cast<Instruction>(FalseVal));
}
// With nsz:
// (X > +/-0.0) ? -X : X --> -fabs(X)
// (X >= +/-0.0) ? -X : X --> -fabs(X)
if (match(CondVal, m_FCmp(Pred, m_Specific(FalseVal), m_AnyZeroFP())) &&
match(TrueVal, m_FNeg(m_Specific(FalseVal))) && SI.hasNoSignedZeros() &&
(Pred == FCmpInst::FCMP_OGT || Pred == FCmpInst::FCMP_OGE ||
Pred == FCmpInst::FCMP_UGT || Pred == FCmpInst::FCMP_UGE)) {
Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, FalseVal, &SI);
return UnaryOperator::CreateFNegFMF(Fabs, cast<Instruction>(TrueVal));
}
// See if we are selecting two values based on a comparison of the two values. // See if we are selecting two values based on a comparison of the two values.
if (ICmpInst *ICI = dyn_cast<ICmpInst>(CondVal)) if (ICmpInst *ICI = dyn_cast<ICmpInst>(CondVal))
if (Instruction *Result = foldSelectInstWithICmp(SI, ICI)) if (Instruction *Result = foldSelectInstWithICmp(SI, ICI))
return Result; return Result;
if (Instruction *Add = foldAddSubSelect(SI, Builder)) if (Instruction *Add = foldAddSubSelect(SI, Builder))
return Add; return Add;
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