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-rw-r--r--llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp38
-rw-r--r--llvm/test/Transforms/InstCombine/fabs.ll60
2 files changed, 55 insertions, 43 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))
diff --git a/llvm/test/Transforms/InstCombine/fabs.ll b/llvm/test/Transforms/InstCombine/fabs.ll
index ef4fc25dff1..9962c02d137 100644
--- a/llvm/test/Transforms/InstCombine/fabs.ll
+++ b/llvm/test/Transforms/InstCombine/fabs.ll
@@ -321,8 +321,8 @@ define double @select_fcmp_nnan_nsz_olt_zero(double %x) {
; CHECK-NEXT: [[TMP1:%.*]] = call nnan nsz double @llvm.fabs.f64(double [[X:%.*]])
; CHECK-NEXT: ret double [[TMP1]]
;
- %ltzero = fcmp nnan nsz olt double %x, 0.0
- %negx = fsub double -0.0, %x
+ %ltzero = fcmp olt double %x, 0.0
+ %negx = fsub nnan nsz double -0.0, %x
%fabs = select i1 %ltzero, double %negx, double %x
ret double %fabs
}
@@ -332,8 +332,8 @@ define double @select_fcmp_nnan_nsz_olt_zero_unary_fneg(double %x) {
; CHECK-NEXT: [[TMP1:%.*]] = call nnan nsz double @llvm.fabs.f64(double [[X:%.*]])
; CHECK-NEXT: ret double [[TMP1]]
;
- %ltzero = fcmp nnan nsz olt double %x, 0.0
- %negx = fneg double %x
+ %ltzero = fcmp olt double %x, 0.0
+ %negx = fneg nnan nsz double %x
%fabs = select i1 %ltzero, double %negx, double %x
ret double %fabs
}
@@ -345,8 +345,8 @@ define float @select_fcmp_nnan_nsz_olt_negzero(float %x) {
; CHECK-NEXT: [[TMP1:%.*]] = call nnan ninf nsz float @llvm.fabs.f32(float [[X:%.*]])
; CHECK-NEXT: ret float [[TMP1]]
;
- %ltzero = fcmp nnan nsz ninf olt float %x, -0.0
- %negx = fsub float -0.0, %x
+ %ltzero = fcmp olt float %x, -0.0
+ %negx = fsub nnan ninf nsz float -0.0, %x
%fabs = select i1 %ltzero, float %negx, float %x
ret float %fabs
}
@@ -356,8 +356,8 @@ define float @select_fcmp_nnan_nsz_olt_negzero_unary_fneg(float %x) {
; CHECK-NEXT: [[TMP1:%.*]] = call nnan ninf nsz float @llvm.fabs.f32(float [[X:%.*]])
; CHECK-NEXT: ret float [[TMP1]]
;
- %ltzero = fcmp nnan nsz ninf olt float %x, -0.0
- %negx = fneg float %x
+ %ltzero = fcmp olt float %x, -0.0
+ %negx = fneg nnan ninf nsz float %x
%fabs = select i1 %ltzero, float %negx, float %x
ret float %fabs
}
@@ -369,8 +369,8 @@ define double @select_fcmp_nnan_nsz_ole_zero(double %x) {
; CHECK-NEXT: [[TMP1:%.*]] = call fast double @llvm.fabs.f64(double [[X:%.*]])
; CHECK-NEXT: ret double [[TMP1]]
;
- %lezero = fcmp fast ole double %x, 0.0
- %negx = fsub double -0.0, %x
+ %lezero = fcmp ole double %x, 0.0
+ %negx = fsub fast double -0.0, %x
%fabs = select i1 %lezero, double %negx, double %x
ret double %fabs
}
@@ -380,8 +380,8 @@ define double @select_fcmp_nnan_nsz_ole_zero_unary_fneg(double %x) {
; CHECK-NEXT: [[TMP1:%.*]] = call fast double @llvm.fabs.f64(double [[X:%.*]])
; CHECK-NEXT: ret double [[TMP1]]
;
- %lezero = fcmp fast ole double %x, 0.0
- %negx = fneg double %x
+ %lezero = fcmp ole double %x, 0.0
+ %negx = fneg fast double %x
%fabs = select i1 %lezero, double %negx, double %x
ret double %fabs
}
@@ -393,8 +393,8 @@ define float @select_fcmp_nnan_nsz_ole_negzero(float %x) {
; CHECK-NEXT: [[TMP1:%.*]] = call nnan nsz float @llvm.fabs.f32(float [[X:%.*]])
; CHECK-NEXT: ret float [[TMP1]]
;
- %lezero = fcmp nnan nsz ole float %x, -0.0
- %negx = fsub float -0.0, %x
+ %lezero = fcmp ole float %x, -0.0
+ %negx = fsub nnan nsz float -0.0, %x
%fabs = select i1 %lezero, float %negx, float %x
ret float %fabs
}
@@ -404,8 +404,8 @@ define float @select_fcmp_nnan_nsz_ole_negzero_unary_fneg(float %x) {
; CHECK-NEXT: [[TMP1:%.*]] = call nnan nsz float @llvm.fabs.f32(float [[X:%.*]])
; CHECK-NEXT: ret float [[TMP1]]
;
- %lezero = fcmp nnan nsz ole float %x, -0.0
- %negx = fneg float %x
+ %lezero = fcmp ole float %x, -0.0
+ %negx = fneg nnan nsz float %x
%fabs = select i1 %lezero, float %negx, float %x
ret float %fabs
}
@@ -417,8 +417,8 @@ define <2 x float> @select_fcmp_nnan_nsz_ogt_zero(<2 x float> %x) {
; CHECK-NEXT: [[TMP1:%.*]] = call nnan nsz arcp <2 x float> @llvm.fabs.v2f32(<2 x float> [[X:%.*]])
; CHECK-NEXT: ret <2 x float> [[TMP1]]
;
- %gtzero = fcmp nnan nsz arcp ogt <2 x float> %x, zeroinitializer
- %negx = fsub <2 x float> <float -0.0, float -0.0>, %x
+ %gtzero = fcmp ogt <2 x float> %x, zeroinitializer
+ %negx = fsub nnan nsz arcp <2 x float> <float -0.0, float -0.0>, %x
%fabs = select <2 x i1> %gtzero, <2 x float> %x, <2 x float> %negx
ret <2 x float> %fabs
}
@@ -428,8 +428,8 @@ define <2 x float> @select_fcmp_nnan_nsz_ogt_zero_unary_fneg(<2 x float> %x) {
; CHECK-NEXT: [[TMP1:%.*]] = call nnan nsz arcp <2 x float> @llvm.fabs.v2f32(<2 x float> [[X:%.*]])
; CHECK-NEXT: ret <2 x float> [[TMP1]]
;
- %gtzero = fcmp nnan nsz arcp ogt <2 x float> %x, zeroinitializer
- %negx = fneg <2 x float> %x
+ %gtzero = fcmp ogt <2 x float> %x, zeroinitializer
+ %negx = fneg nnan nsz arcp <2 x float> %x
%fabs = select <2 x i1> %gtzero, <2 x float> %x, <2 x float> %negx
ret <2 x float> %fabs
}
@@ -441,8 +441,8 @@ define half @select_fcmp_nnan_nsz_ogt_negzero(half %x) {
; CHECK-NEXT: [[TMP1:%.*]] = call fast half @llvm.fabs.f16(half [[X:%.*]])
; CHECK-NEXT: ret half [[TMP1]]
;
- %gtzero = fcmp fast ogt half %x, -0.0
- %negx = fsub half 0.0, %x
+ %gtzero = fcmp ogt half %x, -0.0
+ %negx = fsub fast half 0.0, %x
%fabs = select i1 %gtzero, half %x, half %negx
ret half %fabs
}
@@ -454,8 +454,8 @@ define <2 x double> @select_fcmp_nnan_nsz_oge_zero(<2 x double> %x) {
; CHECK-NEXT: [[TMP1:%.*]] = call reassoc nnan nsz <2 x double> @llvm.fabs.v2f64(<2 x double> [[X:%.*]])
; CHECK-NEXT: ret <2 x double> [[TMP1]]
;
- %gezero = fcmp nnan nsz reassoc oge <2 x double> %x, zeroinitializer
- %negx = fsub <2 x double> <double -0.0, double -0.0>, %x
+ %gezero = fcmp oge <2 x double> %x, zeroinitializer
+ %negx = fsub nnan nsz reassoc <2 x double> <double -0.0, double -0.0>, %x
%fabs = select <2 x i1> %gezero, <2 x double> %x, <2 x double> %negx
ret <2 x double> %fabs
}
@@ -465,8 +465,8 @@ define <2 x double> @select_fcmp_nnan_nsz_oge_zero_unary_fneg(<2 x double> %x) {
; CHECK-NEXT: [[TMP1:%.*]] = call reassoc nnan nsz <2 x double> @llvm.fabs.v2f64(<2 x double> [[X:%.*]])
; CHECK-NEXT: ret <2 x double> [[TMP1]]
;
- %gezero = fcmp nnan nsz reassoc oge <2 x double> %x, zeroinitializer
- %negx = fneg <2 x double> %x
+ %gezero = fcmp oge <2 x double> %x, zeroinitializer
+ %negx = fneg nnan nsz reassoc <2 x double> %x
%fabs = select <2 x i1> %gezero, <2 x double> %x, <2 x double> %negx
ret <2 x double> %fabs
}
@@ -478,8 +478,8 @@ define half @select_fcmp_nnan_nsz_oge_negzero(half %x) {
; CHECK-NEXT: [[TMP1:%.*]] = call nnan nsz half @llvm.fabs.f16(half [[X:%.*]])
; CHECK-NEXT: ret half [[TMP1]]
;
- %gezero = fcmp nnan nsz oge half %x, -0.0
- %negx = fsub half -0.0, %x
+ %gezero = fcmp oge half %x, -0.0
+ %negx = fsub nnan nsz half -0.0, %x
%fabs = select i1 %gezero, half %x, half %negx
ret half %fabs
}
@@ -489,8 +489,8 @@ define half @select_fcmp_nnan_nsz_oge_negzero_unary_fneg(half %x) {
; CHECK-NEXT: [[TMP1:%.*]] = call nnan nsz half @llvm.fabs.f16(half [[X:%.*]])
; CHECK-NEXT: ret half [[TMP1]]
;
- %gezero = fcmp nnan nsz oge half %x, -0.0
- %negx = fneg half %x
+ %gezero = fcmp oge half %x, -0.0
+ %negx = fneg nnan nsz half %x
%fabs = select i1 %gezero, half %x, half %negx
ret half %fabs
}
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