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[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
This commit is contained in:
Sanjay Patel 2018-07-15 14:52:16 +00:00
parent ef71b704c2
commit 92d0c1c129
2 changed files with 16 additions and 16 deletions
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8
llvm/lib/Analysis/InstructionSimplify.cpp
View File

@ -4725,6 +4725,14 @@ static Value *SimplifyIntrinsic(Function *F, IterTy ArgBegin, IterTy ArgEnd,
return LHS;
}
return nullptr;
case Intrinsic::maxnum:
case Intrinsic::minnum:
// If one argument is NaN, return the other argument.
if (match(LHS, m_NaN()))
return RHS;
if (match(RHS, m_NaN()))
return LHS;
return nullptr;
default:
return nullptr;
}

24
llvm/test/Transforms/InstSimplify/floating-point-arithmetic.ll
View File

@ -474,8 +474,7 @@ declare <2 x double> @llvm.maxnum.v2f64(<2 x double>, <2 x double>)
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_op0(double %x) {
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 @maxnum_nan_op1(double %x) {
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_op0(double %x) {
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 double @minnum_nan_op1(double %x) {
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_op0_vec(<2 x double> %x) {
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> @maxnum_nan_op1_vec(<2 x double> %x) {
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_op0_vec(<2 x double> %x) {
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