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llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
| Show First 20 Lines • Show All 2,956 Lines • ▼ Show 20 Lines | Instruction *InstCombinerImpl::visitSelectInst(SelectInst &SI) { | ||||
| // (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); | ||||
| } | } | ||||
| // Negative Fabs: | |||||
| // 1. (X < +/-0.0) ? X : (0.0 - X) --> (0.0 - fabs(X)) | |||||
| // 2. nsz on the sub (canonicalized to FNeg) or on the select: | |||||
| // (X < +/-0.0) ? X : -X --> -X | |||||
spatel: "--> -X" should be "--> -fabs(X)" | |||||
| if (match(CondVal, m_FCmp(Pred, m_Specific(TrueVal), m_AnyZeroFP())) && | |||||
| (Pred == FCmpInst::FCMP_OLT || Pred == FCmpInst::FCMP_ULT)) { | |||||
mnadeemAuthorUnsubmitted <= needs nsz on the select, so I'll just add that condition here and the rest should work fine. mnadeem: `<=` needs nsz on the select, so I'll just add that condition here and the rest should work… | |||||
| if (match(FalseVal, m_FSub(m_PosZeroFP(), m_Specific(TrueVal)))) { | |||||
| Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, TrueVal, &SI); | |||||
| return BinaryOperator::CreateFSubFMF( | |||||
| ConstantFP::get(Fabs->getType(), 0.0), Fabs, | |||||
| cast<Instruction>(FalseVal)); | |||||
| } else if (match(FalseVal, m_FNeg(m_Specific(TrueVal))) && | |||||
| (cast<Instruction>(FalseVal)->hasNoSignedZeros() || | |||||
| SI.hasNoSignedZeros())) { | |||||
| Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, TrueVal, &SI); | |||||
| return UnaryOperator::CreateFNegFMF(Fabs, cast<Instruction>(FalseVal)); | |||||
| } | |||||
| } | |||||
| // 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; | ||||
| ▲ Show 20 Lines • Show All 338 Lines • Show Last 20 Lines | |||||
"--> -X" should be "--> -fabs(X)"