[InstCombine] add more tests for fcmp+select -> fabs; NFC

This should correspond to the patterns in D44091 and might
make handling these in the DAG unnecessary.

llvm-svn: 327689

1 files changed, 160 insertions, 11 deletions

diff --git a/llvm/test/Transforms/InstCombine/fabs.ll b/llvm/test/Transforms/InstCombine/fabs.ll
index 294b74b23da..73fc74eae4a 100644
--- a/llvm/test/Transforms/InstCombine/fabs.ll
+++ b/llvm/test/Transforms/InstCombine/fabs.ll
@@ -245,11 +245,71 @@ define double @multi_use_fabs_fpext(float %x) {
   store volatile double %fpext, double* undef
   ret double %fabs
 }
- 
+
+; X <= 0.0 ? (0.0 - X) : X --> fabs(X)
+
+define double @select_fcmp_ole_zero(double %x) {
+; CHECK-LABEL: @select_fcmp_ole_zero(
+; CHECK-NEXT:    [[LEZERO:%.*]] = fcmp ole double [[X:%.*]], 0.000000e+00
+; CHECK-NEXT:    [[NEGX:%.*]] = fsub double 0.000000e+00, [[X]]
+; CHECK-NEXT:    [[FABS:%.*]] = select i1 [[LEZERO]], double [[NEGX]], double [[X]]
+; CHECK-NEXT:    ret double [[FABS]]
+;
+  %lezero = fcmp ole double %x, 0.0
+  %negx = fsub double 0.0, %x
+  %fabs = select i1 %lezero, double %negx, double %x
+  ret double %fabs
+}
+
+; X <= -0.0 ? (0.0 - X) : X --> fabs(X)
+
+define float @select_fcmp_ole_negzero(float %x) {
+; CHECK-LABEL: @select_fcmp_ole_negzero(
+; CHECK-NEXT:    [[LEZERO:%.*]] = fcmp ole float [[X:%.*]], -0.000000e+00
+; CHECK-NEXT:    [[NEGX:%.*]] = fsub float 0.000000e+00, [[X]]
+; CHECK-NEXT:    [[FABS:%.*]] = select i1 [[LEZERO]], float [[NEGX]], float [[X]]
+; CHECK-NEXT:    ret float [[FABS]]
+;
+  %lezero = fcmp ole float %x, -0.0
+  %negx = fsub float 0.0, %x
+  %fabs = select i1 %lezero, float %negx, float %x
+  ret float %fabs
+}
+
+; X > 0.0 ? X : (0.0 - X) --> fabs(X)
+
+define fp128 @select_fcmp_ogt_zero(fp128 %x) {
+; CHECK-LABEL: @select_fcmp_ogt_zero(
+; CHECK-NEXT:    [[GTZERO:%.*]] = fcmp ogt fp128 [[X:%.*]], 0xL00000000000000000000000000000000
+; CHECK-NEXT:    [[NEGX:%.*]] = fsub fp128 0xL00000000000000000000000000000000, [[X]]
+; CHECK-NEXT:    [[FABS:%.*]] = select i1 [[GTZERO]], fp128 [[X]], fp128 [[NEGX]]
+; CHECK-NEXT:    ret fp128 [[FABS]]
+;
+  %gtzero = fcmp ogt fp128 %x, zeroinitializer
+  %negx = fsub fp128 zeroinitializer, %x
+  %fabs = select i1 %gtzero, fp128 %x, fp128 %negx
+  ret fp128 %fabs
+}
+
+; X > -0.0 ? X : (0.0 - X) --> fabs(X)
+
+define half @select_fcmp_ogt_negzero(half %x) {
+; CHECK-LABEL: @select_fcmp_ogt_negzero(
+; CHECK-NEXT:    [[GTZERO:%.*]] = fcmp ogt half [[X:%.*]], 0xH8000
+; CHECK-NEXT:    [[NEGX:%.*]] = fsub half 0xH0000, [[X]]
+; CHECK-NEXT:    [[FABS:%.*]] = select i1 [[GTZERO]], half [[X]], half [[NEGX]]
+; CHECK-NEXT:    ret half [[FABS]]
+;
+  %gtzero = fcmp ogt half %x, -0.0
+  %negx = fsub half 0.0, %x
+  %fabs = select i1 %gtzero, half %x, half %negx
+  ret half %fabs
+}
+
 ; X < 0.0 ? -X : X --> fabs(X)
 
-define double @select_fcmp_nsz_olt(double %x) {
-; CHECK-LABEL: @select_fcmp_nsz_olt(
+define double @select_fcmp_nsz_olt_zero(double %x) {
+; CHECK-LABEL: @select_fcmp_nsz_olt_zero(
 ; CHECK-NEXT:    [[LTZERO:%.*]] = fcmp nsz olt double [[X:%.*]], 0.000000e+00
 ; CHECK-NEXT:    [[NEGX:%.*]] = fsub double -0.000000e+00, [[X]]
 ; CHECK-NEXT:    [[FABS:%.*]] = select i1 [[LTZERO]], double [[NEGX]], double [[X]]
@@ -261,19 +321,108 @@ define double @select_fcmp_nsz_olt(double %x) {
   ret double %fabs
 }
 
-; X >= 0.0 ? X : -X --> fabs(X)
-; Also test for vector type and more FMF.
+; X < -0.0 ? -X : X --> fabs(X)
+
+define float @select_fcmp_nsz_olt_negzero(float %x) {
+; CHECK-LABEL: @select_fcmp_nsz_olt_negzero(
+; CHECK-NEXT:    [[LTZERO:%.*]] = fcmp ninf nsz olt float [[X:%.*]], -0.000000e+00
+; CHECK-NEXT:    [[NEGX:%.*]] = fsub float -0.000000e+00, [[X]]
+; CHECK-NEXT:    [[FABS:%.*]] = select i1 [[LTZERO]], float [[NEGX]], float [[X]]
+; CHECK-NEXT:    ret float [[FABS]]
+;
+  %ltzero = fcmp nsz ninf olt float %x, -0.0
+  %negx = fsub float -0.0, %x
+  %fabs = select i1 %ltzero, float %negx, float %x
+  ret float %fabs
+}
+
+; X <= 0.0 ? -X : X --> fabs(X)
 
-define <2 x float> @select_fcmp_nsz_ogt(<2 x float> %x) {
-; CHECK-LABEL: @select_fcmp_nsz_ogt(
-; CHECK-NEXT:    [[GEZERO:%.*]] = fcmp ninf nsz oge <2 x float> [[X:%.*]], zeroinitializer
+define double @select_fcmp_nsz_ole_zero(double %x) {
+; CHECK-LABEL: @select_fcmp_nsz_ole_zero(
+; CHECK-NEXT:    [[LEZERO:%.*]] = fcmp fast ole double [[X:%.*]], 0.000000e+00
+; CHECK-NEXT:    [[NEGX:%.*]] = fsub double -0.000000e+00, [[X]]
+; CHECK-NEXT:    [[FABS:%.*]] = select i1 [[LEZERO]], double [[NEGX]], double [[X]]
+; CHECK-NEXT:    ret double [[FABS]]
+;
+  %lezero = fcmp fast ole double %x, 0.0
+  %negx = fsub double -0.0, %x
+  %fabs = select i1 %lezero, double %negx, double %x
+  ret double %fabs
+}
+
+; X <= -0.0 ? -X : X --> fabs(X)
+
+define float @select_fcmp_nsz_ole_negzero(float %x) {
+; CHECK-LABEL: @select_fcmp_nsz_ole_negzero(
+; CHECK-NEXT:    [[LEZERO:%.*]] = fcmp nsz ole float [[X:%.*]], -0.000000e+00
+; CHECK-NEXT:    [[NEGX:%.*]] = fsub float -0.000000e+00, [[X]]
+; CHECK-NEXT:    [[FABS:%.*]] = select i1 [[LEZERO]], float [[NEGX]], float [[X]]
+; CHECK-NEXT:    ret float [[FABS]]
+;
+  %lezero = fcmp nsz ole float %x, -0.0
+  %negx = fsub float -0.0, %x
+  %fabs = select i1 %lezero, float %negx, float %x
+  ret float %fabs
+}
+
+; X > 0.0 ? X : (0.0 - X) --> fabs(X)
+
+define <2 x float> @select_fcmp_nsz_ogt_zero(<2 x float> %x) {
+; CHECK-LABEL: @select_fcmp_nsz_ogt_zero(
+; CHECK-NEXT:    [[GTZERO:%.*]] = fcmp nsz arcp ogt <2 x float> [[X:%.*]], zeroinitializer
 ; CHECK-NEXT:    [[NEGX:%.*]] = fsub <2 x float> <float -0.000000e+00, float -0.000000e+00>, [[X]]
-; CHECK-NEXT:    [[FABS:%.*]] = select <2 x i1> [[GEZERO]], <2 x float> [[X]], <2 x float> [[NEGX]]
+; CHECK-NEXT:    [[FABS:%.*]] = select <2 x i1> [[GTZERO]], <2 x float> [[X]], <2 x float> [[NEGX]]
 ; CHECK-NEXT:    ret <2 x float> [[FABS]]
 ;
-  %gezero = fcmp nsz ninf oge <2 x float> %x, zeroinitializer
+  %gtzero = fcmp nsz arcp ogt <2 x float> %x, zeroinitializer
   %negx = fsub <2 x float> <float -0.0, float -0.0>, %x
-  %fabs = select <2 x i1> %gezero, <2 x float> %x, <2 x float> %negx
+  %fabs = select <2 x i1> %gtzero, <2 x float> %x, <2 x float> %negx
   ret <2 x float> %fabs
 }
 
+; X > -0.0 ? X : (0.0 - X) --> fabs(X)
+
+define half @select_fcmp_nsz_ogt_negzero(half %x) {
+; CHECK-LABEL: @select_fcmp_nsz_ogt_negzero(
+; CHECK-NEXT:    [[GTZERO:%.*]] = fcmp fast ogt half [[X:%.*]], 0xH8000
+; CHECK-NEXT:    [[NEGX:%.*]] = fsub half 0xH0000, [[X]]
+; CHECK-NEXT:    [[FABS:%.*]] = select i1 [[GTZERO]], half [[X]], half [[NEGX]]
+; CHECK-NEXT:    ret half [[FABS]]
+;
+  %gtzero = fcmp fast ogt half %x, -0.0
+  %negx = fsub half 0.0, %x
+  %fabs = select i1 %gtzero, half %x, half %negx
+  ret half %fabs
+}
+
+; X > 0.0 ? X : (0.0 - X) --> fabs(X)
+
+define <2 x double> @select_fcmp_nsz_oge_zero(<2 x double> %x) {
+; CHECK-LABEL: @select_fcmp_nsz_oge_zero(
+; CHECK-NEXT:    [[GEZERO:%.*]] = fcmp reassoc nsz oge <2 x double> [[X:%.*]], zeroinitializer
+; CHECK-NEXT:    [[NEGX:%.*]] = fsub <2 x double> <double -0.000000e+00, double -0.000000e+00>, [[X]]
+; CHECK-NEXT:    [[FABS:%.*]] = select <2 x i1> [[GEZERO]], <2 x double> [[X]], <2 x double> [[NEGX]]
+; CHECK-NEXT:    ret <2 x double> [[FABS]]
+;
+  %gezero = fcmp nsz reassoc oge <2 x double> %x, zeroinitializer
+  %negx = fsub <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
+}
+
+; X > -0.0 ? X : (0.0 - X) --> fabs(X)
+
+define half @select_fcmp_nsz_oge_negzero(half %x) {
+; CHECK-LABEL: @select_fcmp_nsz_oge_negzero(
+; CHECK-NEXT:    [[GEZERO:%.*]] = fcmp nsz oge half [[X:%.*]], 0xH8000
+; CHECK-NEXT:    [[NEGX:%.*]] = fsub half 0xH8000, [[X]]
+; CHECK-NEXT:    [[FABS:%.*]] = select i1 [[GEZERO]], half [[X]], half [[NEGX]]
+; CHECK-NEXT:    ret half [[FABS]]
+;
+  %gezero = fcmp nsz oge half %x, -0.0
+  %negx = fsub half -0.0, %x
+  %fabs = select i1 %gezero, half %x, half %negx
+  ret half %fabs
+}
+