commit 92d0c1c1290aa4e570cce83cf671d4d6d2d6d9c3
author Sanjay Patel <spatel@rotateright.com> Sun Jul 15 14:52:16 2018 +0000
committer Sanjay Patel <spatel@rotateright.com> Sun Jul 15 14:52:16 2018 +0000
tree 3d633c5c5a5a308d02e901e2cef1922c628e1f6e
parent ef71b704c21c33c744f104ca443ba671270b3c3a

[InstSimplify] fold minnum/maxnum with NaN arg

This fold is repeated/misplaced in instcombine, but I'm
not sure if it's safe to remove that yet because some
other folds appear to be asserting that the transform
has occurred within instcombine itself.

This isn't the best fix for PR37776, but it probably
hides the bug with the given code example:
https://bugs.llvm.org/show_bug.cgi?id=37776

We have another test to demonstrate the more general bug.

llvm-svn: 337127

llvm/test/Transforms/InstSimplify/floating-point-arithmetic.ll

diff --git a/llvm/test/Transforms/InstSimplify/floating-point-arithmetic.ll b/llvm/test/Transforms/InstSimplify/floating-point-arithmetic.ll
index ead4bdb..afd375f 100644
--- a/llvm/test/Transforms/InstSimplify/floating-point-arithmetic.ll
+++ b/llvm/test/Transforms/InstSimplify/floating-point-arithmetic.ll
@@ -474,8 +474,7 @@
 
 define double @maxnum_nan_op0(double %x) {
 ; CHECK-LABEL: @maxnum_nan_op0(
-; CHECK-NEXT:    [[R:%.*]] = call double @llvm.maxnum.f64(double 0x7FF8000000000000, double [[X:%.*]])
-; CHECK-NEXT:    ret double [[R]]
+; CHECK-NEXT:    ret double [[X:%.*]]
 ;
   %r = call double @llvm.maxnum.f64(double 0x7ff8000000000000, double %x)
   ret double %r
@@ -483,8 +482,7 @@
 
 define double @maxnum_nan_op1(double %x) {
 ; CHECK-LABEL: @maxnum_nan_op1(
-; CHECK-NEXT:    [[R:%.*]] = call double @llvm.maxnum.f64(double [[X:%.*]], double 0x7FF800000000DEAD)
-; CHECK-NEXT:    ret double [[R]]
+; CHECK-NEXT:    ret double [[X:%.*]]
 ;
   %r = call double @llvm.maxnum.f64(double %x, double 0x7ff800000000dead)
   ret double %r
@@ -492,8 +490,7 @@
 
 define double @minnum_nan_op0(double %x) {
 ; CHECK-LABEL: @minnum_nan_op0(
-; CHECK-NEXT:    [[R:%.*]] = call double @llvm.minnum.f64(double 0x7FF8000DEAD00000, double [[X:%.*]])
-; CHECK-NEXT:    ret double [[R]]
+; CHECK-NEXT:    ret double [[X:%.*]]
 ;
   %r = call double @llvm.minnum.f64(double 0x7ff8000dead00000, double %x)
   ret double %r
@@ -501,8 +498,7 @@
 
 define double @minnum_nan_op1(double %x) {
 ; CHECK-LABEL: @minnum_nan_op1(
-; CHECK-NEXT:    [[R:%.*]] = call double @llvm.minnum.f64(double [[X:%.*]], double 0x7FF800DEAD00DEAD)
-; CHECK-NEXT:    ret double [[R]]
+; CHECK-NEXT:    ret double [[X:%.*]]
 ;
   %r = call double @llvm.minnum.f64(double %x, double 0x7ff800dead00dead)
   ret double %r
@@ -510,8 +506,7 @@
 
 define <2 x double> @maxnum_nan_op0_vec(<2 x double> %x) {
 ; CHECK-LABEL: @maxnum_nan_op0_vec(
-; CHECK-NEXT:    [[R:%.*]] = call <2 x double> @llvm.maxnum.v2f64(<2 x double> <double 0x7FF8000000000000, double undef>, <2 x double> [[X:%.*]])
-; CHECK-NEXT:    ret <2 x double> [[R]]
+; CHECK-NEXT:    ret <2 x double> [[X:%.*]]
 ;
   %r = call <2 x double> @llvm.maxnum.v2f64(<2 x double> <double 0x7ff8000000000000, double undef>, <2 x double> %x)
   ret <2 x double> %r
@@ -519,8 +514,7 @@
 
 define <2 x double> @maxnum_nan_op1_vec(<2 x double> %x) {
 ; CHECK-LABEL: @maxnum_nan_op1_vec(
-; CHECK-NEXT:    [[R:%.*]] = call <2 x double> @llvm.maxnum.v2f64(<2 x double> [[X:%.*]], <2 x double> <double 0x7FF800000000DEAD, double 0x7FF8FFFFFFFFFFFF>)
-; CHECK-NEXT:    ret <2 x double> [[R]]
+; CHECK-NEXT:    ret <2 x double> [[X:%.*]]
 ;
   %r = call <2 x double> @llvm.maxnum.v2f64(<2 x double> %x, <2 x double> <double 0x7ff800000000dead, double 0x7ff8ffffffffffff>)
   ret <2 x double> %r
@@ -528,8 +522,7 @@
 
 define <2 x double> @minnum_nan_op0_vec(<2 x double> %x) {
 ; CHECK-LABEL: @minnum_nan_op0_vec(
-; CHECK-NEXT:    [[R:%.*]] = call <2 x double> @llvm.minnum.v2f64(<2 x double> <double undef, double 0x7FF8000DEAD00000>, <2 x double> [[X:%.*]])
-; CHECK-NEXT:    ret <2 x double> [[R]]
+; CHECK-NEXT:    ret <2 x double> [[X:%.*]]
 ;
   %r = call <2 x double> @llvm.minnum.v2f64(<2 x double> <double undef, double 0x7ff8000dead00000>, <2 x double> %x)
   ret <2 x double> %r
@@ -537,8 +530,7 @@
 
 define <2 x double> @minnum_nan_op1_vec(<2 x double> %x) {
 ; CHECK-LABEL: @minnum_nan_op1_vec(
-; CHECK-NEXT:    [[R:%.*]] = call <2 x double> @llvm.minnum.v2f64(<2 x double> [[X:%.*]], <2 x double> <double 0x7FF800DEAD00DEAD, double 0x7FF800DEAD00DEAD>)
-; CHECK-NEXT:    ret <2 x double> [[R]]
+; CHECK-NEXT:    ret <2 x double> [[X:%.*]]
 ;
   %r = call <2 x double> @llvm.minnum.v2f64(<2 x double> %x, <2 x double> <double 0x7ff800dead00dead, double 0x7ff800dead00dead>)
   ret <2 x double> %r