llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-llvm-support Author: Matt Arsenault (arsenm) <details> <summary>Changes</summary> Handle multiple use copysign in SimplifyDemandedFPClass --- Full diff: https://github.com/llvm/llvm-project/pull/176917.diff 3 Files Affected: - (modified) llvm/include/llvm/Support/KnownFPClass.h (+7) - (modified) llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp (+36-3) - (modified) llvm/test/Transforms/InstCombine/simplify-demanded-fpclass.ll (+7-7) ``````````diff diff --git a/llvm/include/llvm/Support/KnownFPClass.h b/llvm/include/llvm/Support/KnownFPClass.h index 3dd2cbad873d2..4d0a46f6ce602 100644 --- a/llvm/include/llvm/Support/KnownFPClass.h +++ b/llvm/include/llvm/Support/KnownFPClass.h @@ -290,6 +290,13 @@ struct KnownFPClass { KnownFPClasses &= (fcPositive | fcNan); } + static KnownFPClass copysign(const KnownFPClass &KnownMag, + const KnownFPClass &KnownSign) { + KnownFPClass Known = KnownMag; + Known.copysign(KnownSign); + return Known; + } + // Propagate knowledge that a non-NaN source implies the result can also not // be a NaN. For unconstrained operations, signaling nans are not guaranteed // to be quieted but cannot be introduced. diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp index 9212cfd8fd28d..805a0ca8a9b97 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp @@ -2600,7 +2600,9 @@ Value *InstCombinerImpl::SimplifyDemandedUseFPClass(Instruction *I, case Intrinsic::copysign: { // Flip on more potentially demanded classes const FPClassTest DemandedMaskAnySign = llvm::unknown_sign(DemandedMask); - if (SimplifyDemandedFPClass(CI, 0, DemandedMaskAnySign, Known, Depth + 1)) + KnownFPClass KnownMag; + if (SimplifyDemandedFPClass(CI, 0, DemandedMaskAnySign, KnownMag, + Depth + 1)) return I; if ((DemandedMask & fcNegative) == DemandedMask) { @@ -2616,7 +2618,8 @@ Value *InstCombinerImpl::SimplifyDemandedUseFPClass(Instruction *I, } if (Value *Simplified = simplifyDemandedFPClassCopysignMag( - CI->getArgOperand(0), DemandedMask, Known, FMF.noSignedZeros())) + CI->getArgOperand(0), DemandedMask, KnownMag, + FMF.noSignedZeros())) return Simplified; KnownFPClass KnownSign = computeKnownFPClass(CI->getArgOperand(1), @@ -2643,7 +2646,7 @@ Value *InstCombinerImpl::SimplifyDemandedUseFPClass(Instruction *I, return I; } - Known.copysign(KnownSign); + Known = KnownFPClass::copysign(KnownMag, KnownSign); break; } case Intrinsic::maximum: @@ -3147,6 +3150,36 @@ Value *InstCombinerImpl::SimplifyMultipleUseDemandedFPClass( return Simplified; break; } + case Intrinsic::copysign: { + Value *Src = CI->getArgOperand(0); + Value *Sign = CI->getArgOperand(1); + KnownFPClass KnownSrc = + computeKnownFPClass(Src, fcAllFlags, CxtI, Depth + 1); + + // Rule out some cases by magnitude, which may help prove the sign bit is + // one direction or the other. + KnownSrc.knownNot(~llvm::unknown_sign(DemandedMask)); + + // Cannot use nsz in the multiple use case. + if (Value *Simplified = simplifyDemandedFPClassCopysignMag( + Src, DemandedMask, KnownSrc, /*NSZ=*/false)) + return Simplified; + + KnownFPClass KnownSign = + computeKnownFPClass(Sign, fcAllFlags, CxtI, Depth + 1); + + if (FMF.noInfs()) + KnownSign.knownNot(fcInf); + if (FMF.noNaNs()) + KnownSign.knownNot(fcNan); + + if (KnownSign.SignBit && KnownSrc.SignBit && + *KnownSign.SignBit == *KnownSrc.SignBit) + return Src; + + Known = KnownFPClass::copysign(KnownSrc, KnownSign); + break; + } case Intrinsic::maximum: case Intrinsic::minimum: case Intrinsic::maximumnum: diff --git a/llvm/test/Transforms/InstCombine/simplify-demanded-fpclass.ll b/llvm/test/Transforms/InstCombine/simplify-demanded-fpclass.ll index 45a50f04e1b0f..683b31869e138 100644 --- a/llvm/test/Transforms/InstCombine/simplify-demanded-fpclass.ll +++ b/llvm/test/Transforms/InstCombine/simplify-demanded-fpclass.ll @@ -2136,7 +2136,7 @@ define nofpclass(nan ninf nnorm nsub nzero) float @ret_only_positive__copysign_s ; CHECK-SAME: (float nofpclass(nan ninf nzero nsub nnorm) [[ALWAYS_POSITIVE:%.*]], float [[UNKNOWN:%.*]], ptr [[PTR:%.*]]) { ; CHECK-NEXT: [[COPYSIGN:%.*]] = call float @llvm.copysign.f32(float [[ALWAYS_POSITIVE]], float [[UNKNOWN]]) ; CHECK-NEXT: store float [[COPYSIGN]], ptr [[PTR]], align 4 -; CHECK-NEXT: ret float [[COPYSIGN]] +; CHECK-NEXT: ret float [[ALWAYS_POSITIVE]] ; %copysign = call float @llvm.copysign.f32(float %always.positive, float %unknown) store float %copysign, ptr %ptr @@ -2159,7 +2159,7 @@ define nofpclass(nan pinf pnorm psub pzero) float @ret_only_negative__copysign_s ; CHECK-SAME: (float nofpclass(nan pinf pzero psub pnorm) [[ALWAYS_NEGATIVE:%.*]], float [[UNKNOWN:%.*]], ptr [[PTR:%.*]]) { ; CHECK-NEXT: [[COPYSIGN:%.*]] = call float @llvm.copysign.f32(float [[ALWAYS_NEGATIVE]], float [[UNKNOWN]]) ; CHECK-NEXT: store float [[COPYSIGN]], ptr [[PTR]], align 4 -; CHECK-NEXT: ret float [[COPYSIGN]] +; CHECK-NEXT: ret float [[ALWAYS_NEGATIVE]] ; %copysign = call float @llvm.copysign.f32(float %always.negative, float %unknown) store float %copysign, ptr %ptr @@ -2228,7 +2228,7 @@ define nofpclass(nan nnorm nsub nzero) float @ret_only_positive_or_ninf__copysig ; CHECK-SAME: (float nofpclass(nan ninf nzero nsub nnorm) [[ALWAYS_POSITIVE:%.*]], float [[UNKNOWN:%.*]], ptr [[PTR:%.*]]) { ; CHECK-NEXT: [[COPYSIGN:%.*]] = call ninf float @llvm.copysign.f32(float [[ALWAYS_POSITIVE]], float [[UNKNOWN]]) ; CHECK-NEXT: store float [[COPYSIGN]], ptr [[PTR]], align 4 -; CHECK-NEXT: ret float [[COPYSIGN]] +; CHECK-NEXT: ret float [[ALWAYS_POSITIVE]] ; %copysign = call ninf float @llvm.copysign.f32(float %always.positive, float %unknown) store float %copysign, ptr %ptr @@ -2386,7 +2386,7 @@ define nofpclass(pinf pnorm psub pzero) float @ret_only_negative_or_nan__copysig ; CHECK-SAME: (float nofpclass(pinf pzero psub pnorm) [[ALWAYS_NEGATIVE_OR_NAN:%.*]], float [[UNKNOWN:%.*]], ptr [[PTR:%.*]]) { ; CHECK-NEXT: [[COPYSIGN:%.*]] = call nnan float @llvm.copysign.f32(float [[ALWAYS_NEGATIVE_OR_NAN]], float [[UNKNOWN]]) ; CHECK-NEXT: store float [[COPYSIGN]], ptr [[PTR]], align 4 -; CHECK-NEXT: ret float [[COPYSIGN]] +; CHECK-NEXT: ret float [[ALWAYS_NEGATIVE_OR_NAN]] ; %copysign = call nnan float @llvm.copysign.f32(float %always.negative.or.nan, float %unknown) store float %copysign, ptr %ptr @@ -2455,7 +2455,7 @@ define nofpclass(pinf pnorm psub pzero) float @ret_only_positive_or_nan__copysig ; CHECK-SAME: (float nofpclass(pinf pzero psub pnorm) [[ALWAYS_NEGATIVE_OR_NAN:%.*]], float [[UNKNOWN:%.*]], ptr [[PTR:%.*]]) { ; CHECK-NEXT: [[COPYSIGN:%.*]] = call nnan float @llvm.copysign.f32(float [[ALWAYS_NEGATIVE_OR_NAN]], float [[UNKNOWN]]) ; CHECK-NEXT: store float [[COPYSIGN]], ptr [[PTR]], align 4 -; CHECK-NEXT: ret float [[COPYSIGN]] +; CHECK-NEXT: ret float [[ALWAYS_NEGATIVE_OR_NAN]] ; %copysign = call nnan float @llvm.copysign.f32(float %always.negative.or.nan, float %unknown) store float %copysign, ptr %ptr @@ -2479,7 +2479,7 @@ define nofpclass(nan) float @ret_no_nan__copysign_ninf__src_known_negative_or_na ; CHECK-SAME: (float nofpclass(pinf pzero psub pnorm) [[ALWAYS_NEGATIVE_OR_NAN:%.*]], float nofpclass(nan pzero psub pnorm) [[ALWAYS_NEGATIVE_OR_PINF:%.*]], ptr [[PTR:%.*]]) { ; CHECK-NEXT: [[COPYSIGN:%.*]] = call ninf float @llvm.copysign.f32(float [[ALWAYS_NEGATIVE_OR_NAN]], float [[ALWAYS_NEGATIVE_OR_PINF]]) ; CHECK-NEXT: store float [[COPYSIGN]], ptr [[PTR]], align 4 -; CHECK-NEXT: ret float [[COPYSIGN]] +; CHECK-NEXT: ret float [[ALWAYS_NEGATIVE_OR_NAN]] ; %copysign = call ninf float @llvm.copysign.f32(float %always.negative.or.nan, float %always.negative.or.pinf) store float %copysign, ptr %ptr @@ -2503,7 +2503,7 @@ define nofpclass(nan) float @ret_no_nan__copysign_ninf__src_known_negative_or_na ; CHECK-SAME: (float nofpclass(ninf nzero nsub nnorm) [[ALWAYS_POSITIVE_OR_NAN:%.*]], float nofpclass(nan nzero nsub nnorm) [[ALWAYS_NEGATIVE_OR_PINF:%.*]], ptr [[PTR:%.*]]) { ; CHECK-NEXT: [[COPYSIGN:%.*]] = call ninf float @llvm.copysign.f32(float [[ALWAYS_POSITIVE_OR_NAN]], float [[ALWAYS_NEGATIVE_OR_PINF]]) ; CHECK-NEXT: store float [[COPYSIGN]], ptr [[PTR]], align 4 -; CHECK-NEXT: ret float [[COPYSIGN]] +; CHECK-NEXT: ret float [[ALWAYS_POSITIVE_OR_NAN]] ; %copysign = call ninf float @llvm.copysign.f32(float %always.positive.or.nan, float %always.negative.or.pinf) store float %copysign, ptr %ptr `````````` </details> https://github.com/llvm/llvm-project/pull/176917 _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
