diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp | 38 |
1 files changed, 25 insertions, 13 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp index 5a14726bee2..aeeab4788f2 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp @@ -1883,22 +1883,34 @@ Instruction *InstCombiner::visitSelectInst(SelectInst &SI) { Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, X, FCI); return replaceInstUsesWith(SI, Fabs); } - // 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 (FCI->hasNoSignedZeros() && - ((X == FalseVal && match(TrueVal, m_FNeg(m_Specific(X))) && - (Pred == FCmpInst::FCMP_OLT || Pred == FCmpInst::FCMP_OLE)) || - (X == TrueVal && match(FalseVal, m_FNeg(m_Specific(X))) && - (Pred == FCmpInst::FCMP_OGT || Pred == FCmpInst::FCMP_OGE)))) { - Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, X, FCI); - return replaceInstUsesWith(SI, Fabs); - } } } + // FIXME: These folds should test/propagate FMF from the select, not the fneg. + // With nnan and nsz: + // (X < +/-0.0) ? -X : X --> fabs(X) + // (X <= +/-0.0) ? -X : X --> fabs(X) + Instruction *FNeg; + if (match(CondVal, m_FCmp(Pred, m_Specific(FalseVal), m_AnyZeroFP())) && + match(TrueVal, m_FNeg(m_Specific(FalseVal))) && + match(TrueVal, m_Instruction(FNeg)) && + FNeg->hasNoNaNs() && FNeg->hasNoSignedZeros() && + (Pred == FCmpInst::FCMP_OLT || Pred == FCmpInst::FCMP_OLE)) { + Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, FalseVal, FNeg); + return replaceInstUsesWith(SI, Fabs); + } + // With nnan and 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))) && + match(FalseVal, m_Instruction(FNeg)) && + FNeg->hasNoNaNs() && FNeg->hasNoSignedZeros() && + (Pred == FCmpInst::FCMP_OGT || Pred == FCmpInst::FCMP_OGE)) { + Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, TrueVal, FNeg); + return replaceInstUsesWith(SI, Fabs); + } + // See if we are selecting two values based on a comparison of the two values. if (ICmpInst *ICI = dyn_cast<ICmpInst>(CondVal)) if (Instruction *Result = foldSelectInstWithICmp(SI, ICI)) |
