diff options
author | Vaibhav <56088720+VaibhavRumale@users.noreply.github.com> | 2024-06-27 11:10:33 -0700 |
---|---|---|
committer | GitHub <noreply@github.com> | 2024-06-27 20:10:33 +0200 |
commit | ea686686477921f571d3b492de44664eafb82465 (patch) | |
tree | fc782fd1faa409bc03138ddaf8768b3ca6e61259 | |
parent | fa0e9acea5e4d363eef6acc484afc1b22ab8e698 (diff) | |
download | llvm-ea686686477921f571d3b492de44664eafb82465.zip llvm-ea686686477921f571d3b492de44664eafb82465.tar.gz llvm-ea686686477921f571d3b492de44664eafb82465.tar.bz2 |
[InstCombine] Add fold for fabs(-x) -> fabs(x) (#95627)
This patch folds `fabs(-x) -> fabs(x)`
Closes #94170
Proofs: https://alive2.llvm.org/ce/z/gjzmgf
-rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp | 14 | ||||
-rw-r--r-- | llvm/test/Transforms/InstCombine/fabs-fneg-fold.ll | 186 |
2 files changed, 196 insertions, 4 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp index 56bd79f..921ed6e 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp @@ -2511,16 +2511,22 @@ Instruction *InstCombinerImpl::visitCallInst(CallInst &CI) { } case Intrinsic::fabs: { Value *Cond, *TVal, *FVal; - if (match(II->getArgOperand(0), - m_Select(m_Value(Cond), m_Value(TVal), m_Value(FVal)))) { + Value *Arg = II->getArgOperand(0); + Value *X; + // fabs (-X) --> fabs (X) + if (match(Arg, m_FNeg(m_Value(X)))) { + CallInst *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, X, II); + return replaceInstUsesWith(CI, Fabs); + } + + if (match(Arg, m_Select(m_Value(Cond), m_Value(TVal), m_Value(FVal)))) { // fabs (select Cond, TrueC, FalseC) --> select Cond, AbsT, AbsF if (isa<Constant>(TVal) || isa<Constant>(FVal)) { CallInst *AbsT = Builder.CreateCall(II->getCalledFunction(), {TVal}); CallInst *AbsF = Builder.CreateCall(II->getCalledFunction(), {FVal}); SelectInst *SI = SelectInst::Create(Cond, AbsT, AbsF); FastMathFlags FMF1 = II->getFastMathFlags(); - FastMathFlags FMF2 = - cast<SelectInst>(II->getArgOperand(0))->getFastMathFlags(); + FastMathFlags FMF2 = cast<SelectInst>(Arg)->getFastMathFlags(); FMF2.setNoSignedZeros(false); SI->setFastMathFlags(FMF1 | FMF2); return SI; diff --git a/llvm/test/Transforms/InstCombine/fabs-fneg-fold.ll b/llvm/test/Transforms/InstCombine/fabs-fneg-fold.ll new file mode 100644 index 0000000..a1988e5 --- /dev/null +++ b/llvm/test/Transforms/InstCombine/fabs-fneg-fold.ll @@ -0,0 +1,186 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5 +; RUN: opt -S -passes=instcombine %s | FileCheck %s + +define float @fabs_fneg_basic(float %x) { +; CHECK-LABEL: define float @fabs_fneg_basic( +; CHECK-SAME: float [[X:%.*]]) { +; CHECK-NEXT: [[FABS:%.*]] = call float @llvm.fabs.f32(float [[X]]) +; CHECK-NEXT: ret float [[FABS]] +; + %neg = fneg float %x + %fabs = call float @llvm.fabs.f32(float %neg) + ret float %fabs +} + +define <2 x float> @fabs_fneg_v2f32(<2 x float> %x) { +; CHECK-LABEL: define <2 x float> @fabs_fneg_v2f32( +; CHECK-SAME: <2 x float> [[X:%.*]]) { +; CHECK-NEXT: [[FABS:%.*]] = call <2 x float> @llvm.fabs.v2f32(<2 x float> [[X]]) +; CHECK-NEXT: ret <2 x float> [[FABS]] +; + %neg = fneg <2 x float> %x + %fabs = call <2 x float> @llvm.fabs.v2f32(<2 x float> %neg) + ret <2 x float> %fabs +} + +define double @fabs_fneg_f64(double %x) { +; CHECK-LABEL: define double @fabs_fneg_f64( +; CHECK-SAME: double [[X:%.*]]) { +; CHECK-NEXT: [[FABS:%.*]] = call double @llvm.fabs.f64(double [[X]]) +; CHECK-NEXT: ret double [[FABS]] +; + %neg = fneg double %x + %fabs = call double @llvm.fabs.f64(double %neg) + ret double %fabs +} + +define <4 x double> @fabs_fneg_v4f64(<4 x double> %x) { +; CHECK-LABEL: define <4 x double> @fabs_fneg_v4f64( +; CHECK-SAME: <4 x double> [[X:%.*]]) { +; CHECK-NEXT: [[FABS:%.*]] = call <4 x double> @llvm.fabs.v4f64(<4 x double> [[X]]) +; CHECK-NEXT: ret <4 x double> [[FABS]] +; + %neg = fneg <4 x double> %x + %fabs = call <4 x double> @llvm.fabs.v4f64(<4 x double> %neg) + ret <4 x double> %fabs +} + +define half @fabs_fneg_f16(half %x) { +; CHECK-LABEL: define half @fabs_fneg_f16( +; CHECK-SAME: half [[X:%.*]]) { +; CHECK-NEXT: [[FABS:%.*]] = call half @llvm.fabs.f16(half [[X]]) +; CHECK-NEXT: ret half [[FABS]] +; + %neg = fneg half %x + %fabs = call half @llvm.fabs.f16(half %neg) + ret half %fabs +} + +define float @fabs_copysign_nnan(float %x, float %y) { +; CHECK-LABEL: define float @fabs_copysign_nnan( +; CHECK-SAME: float [[X:%.*]], float [[Y:%.*]]) { +; CHECK-NEXT: [[FABS:%.*]] = call nnan float @llvm.fabs.f32(float [[X]]) +; CHECK-NEXT: ret float [[FABS]] +; + %copysign = call float @llvm.copysign.f32(float %x, float %y) + %fabs = call nnan float @llvm.fabs.f32(float %copysign) + ret float %fabs +} + + +define float @fabs_copysign_ninf(float %x, float %y) { +; CHECK-LABEL: define float @fabs_copysign_ninf( +; CHECK-SAME: float [[X:%.*]], float [[Y:%.*]]) { +; CHECK-NEXT: [[FABS:%.*]] = call ninf float @llvm.fabs.f32(float [[X]]) +; CHECK-NEXT: ret float [[FABS]] +; + %copysign = call float @llvm.copysign.f32(float %x, float %y) + %fabs = call ninf float @llvm.fabs.f32(float %copysign) + ret float %fabs +} + +define float @fabs_copysign_nsz(float %x, float %y) { +; CHECK-LABEL: define float @fabs_copysign_nsz( +; CHECK-SAME: float [[X:%.*]], float [[Y:%.*]]) { +; CHECK-NEXT: [[FABS:%.*]] = call nsz float @llvm.fabs.f32(float [[X]]) +; CHECK-NEXT: ret float [[FABS]] +; + %copysign = call float @llvm.copysign.f32(float %x, float %y) + %fabs = call nsz float @llvm.fabs.f32(float %copysign) + ret float %fabs +} + +define float @fabs_copysign_nnan_negative(float %x, float %y) { +; CHECK-LABEL: define float @fabs_copysign_nnan_negative( +; CHECK-SAME: float [[X:%.*]], float [[Y:%.*]]) { +; CHECK-NEXT: [[FABS:%.*]] = call nnan float @llvm.fabs.f32(float [[X]]) +; CHECK-NEXT: ret float [[FABS]] +; + %copysign = call float @llvm.copysign.f32(float %x, float %y) + %fabs = call nnan float @llvm.fabs.f32(float %copysign) + ret float %fabs +} + + +define float @fabs_copysign_ninf_negative(float %x, float %y) { +; CHECK-LABEL: define float @fabs_copysign_ninf_negative( +; CHECK-SAME: float [[X:%.*]], float [[Y:%.*]]) { +; CHECK-NEXT: [[FABS:%.*]] = call ninf float @llvm.fabs.f32(float [[X]]) +; CHECK-NEXT: ret float [[FABS]] +; + %copysign = call float @llvm.copysign.f32(float %x, float %y) + %fabs = call ninf float @llvm.fabs.f32(float %copysign) + ret float %fabs +} + +define float @fabs_copysign_nsz_negative(float %x, float %y) { +; CHECK-LABEL: define float @fabs_copysign_nsz_negative( +; CHECK-SAME: float [[X:%.*]], float [[Y:%.*]]) { +; CHECK-NEXT: [[FABS:%.*]] = call nsz float @llvm.fabs.f32(float [[X]]) +; CHECK-NEXT: ret float [[FABS]] +; + %copysign = call float @llvm.copysign.f32(float %x, float %y) + %fabs = call nsz float @llvm.fabs.f32(float %copysign) + ret float %fabs +} + +define float @fabs_fneg_no_fabs(float %x) { +; CHECK-LABEL: define float @fabs_fneg_no_fabs( +; CHECK-SAME: float [[X:%.*]]) { +; CHECK-NEXT: [[NEG:%.*]] = fneg float [[X]] +; CHECK-NEXT: ret float [[NEG]] +; + %neg = fneg float %x + ret float %neg +} + +define <2 x float> @fabs_fneg_splat_v2f32(<2 x float> %x) { +; CHECK-LABEL: define <2 x float> @fabs_fneg_splat_v2f32( +; CHECK-SAME: <2 x float> [[X:%.*]]) { +; CHECK-NEXT: ret <2 x float> <float 2.000000e+00, float 2.000000e+00> +; + %neg = fneg <2 x float> <float -2.0, float -2.0> + %fabs = call <2 x float> @llvm.fabs.v2f32(<2 x float> %neg) + ret <2 x float> %fabs +} + + +define <2 x float> @fabs_fneg_splat_poison_v2f32(<2 x float> %x) { +; CHECK-LABEL: define <2 x float> @fabs_fneg_splat_poison_v2f32( +; CHECK-SAME: <2 x float> [[X:%.*]]) { +; CHECK-NEXT: [[FABS:%.*]] = call <2 x float> @llvm.fabs.v2f32(<2 x float> <float -2.000000e+00, float poison>) +; CHECK-NEXT: ret <2 x float> [[FABS]] +; + %neg = fneg <2 x float> <float 2.0, float poison> + %fabs = call <2 x float> @llvm.fabs.v2f32(<2 x float> %neg) + ret <2 x float> %fabs +} + +define <2 x float> @fabs_fneg_non_splat_v2f32(<2 x float> %x) { +; CHECK-LABEL: define <2 x float> @fabs_fneg_non_splat_v2f32( +; CHECK-SAME: <2 x float> [[X:%.*]]) { +; CHECK-NEXT: ret <2 x float> <float 2.000000e+00, float 3.000000e+00> +; + %neg = fneg <2 x float> <float 2.0, float 3.0> + %fabs = call <2 x float> @llvm.fabs.v2f32(<2 x float> %neg) + ret <2 x float> %fabs +} + +declare void @use(float) + +define float @fabs_fneg_multi_use(float %x) { +; CHECK-LABEL: define float @fabs_fneg_multi_use( +; CHECK-SAME: float [[X:%.*]]) { +; CHECK-NEXT: [[NEG:%.*]] = fneg float [[X]] +; CHECK-NEXT: call void @use(float [[NEG]]) +; CHECK-NEXT: [[FABS:%.*]] = call float @llvm.fabs.f32(float [[X]]) +; CHECK-NEXT: ret float [[FABS]] +; + %neg = fneg float %x + call void @use(float %neg) + %fabs = call float @llvm.fabs.f32(float %neg) + ret float %fabs +} + + + |