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[InstSimplify] fold 'fcmp nnan ult X, 0.0' when X is not negative 

This is the inverted case for the transform added with D53874 / rL345725.

llvm-svn: 345728
This commit is contained in:
Sanjay Patel 2018-10-31 15:35:46 +00:00
parent b9fe3fbb57
commit d4dc30c20d
2 changed files with 8 additions and 13 deletions
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5
llvm/lib/Analysis/InstructionSimplify.cpp
View File

@ -3620,8 +3620,11 @@ static Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
if (CannotBeOrderedLessThanZero(LHS, Q.TLI))
return getTrue(RetTy);
break;
case FCmpInst::FCMP_ULT:
if (FMF.noNaNs() && CannotBeOrderedLessThanZero(LHS, Q.TLI))
return getFalse(RetTy);
break;
case FCmpInst::FCMP_OLT:
// X < 0
if (CannotBeOrderedLessThanZero(LHS, Q.TLI))
return getFalse(RetTy);
break;

16
llvm/test/Transforms/InstSimplify/floating-point-compare.ll
View File

@ -290,9 +290,7 @@ define <2 x i1> @UIToFP_is_not_negative_vec(<2 x i32> %x) {
define i1 @UIToFP_nnan_is_not_negative(i32 %x) {
; CHECK-LABEL: @UIToFP_nnan_is_not_negative(
; CHECK-NEXT: [[A:%.*]] = uitofp i32 [[X:%.*]] to float
; CHECK-NEXT: [[R:%.*]] = fcmp nnan ult float [[A]], 0.000000e+00
; CHECK-NEXT: ret i1 [[R]]
; CHECK-NEXT: ret i1 false
;
%a = uitofp i32 %x to float
%r = fcmp nnan ult float %a, 0.000000e+00
@ -301,9 +299,7 @@ define i1 @UIToFP_nnan_is_not_negative(i32 %x) {
define <2 x i1> @UIToFP_nnan_is_not_negative_vec(<2 x i32> %x) {
; CHECK-LABEL: @UIToFP_nnan_is_not_negative_vec(
; CHECK-NEXT: [[A:%.*]] = uitofp <2 x i32> [[X:%.*]] to <2 x float>
; CHECK-NEXT: [[R:%.*]] = fcmp nnan ult <2 x float> [[A]], zeroinitializer
; CHECK-NEXT: ret <2 x i1> [[R]]
; CHECK-NEXT: ret <2 x i1> zeroinitializer
;
%a = uitofp <2 x i32> %x to <2 x float>
%r = fcmp nnan ult <2 x float> %a, zeroinitializer
@ -366,9 +362,7 @@ define <2 x i1> @fabs_is_not_negative_vec(<2 x double> %x) {
define i1 @fabs_nnan_is_not_negative(double %x) {
; CHECK-LABEL: @fabs_nnan_is_not_negative(
; CHECK-NEXT: [[FABS:%.*]] = tail call double @llvm.fabs.f64(double [[X:%.*]])
; CHECK-NEXT: [[CMP:%.*]] = fcmp nnan ult double [[FABS]], 0.000000e+00
; CHECK-NEXT: ret i1 [[CMP]]
; CHECK-NEXT: ret i1 false
;
%fabs = tail call double @llvm.fabs.f64(double %x)
%cmp = fcmp nnan ult double %fabs, 0.0
@ -377,9 +371,7 @@ define i1 @fabs_nnan_is_not_negative(double %x) {
define <2 x i1> @fabs_nnan_is_not_negative_vec(<2 x double> %x) {
; CHECK-LABEL: @fabs_nnan_is_not_negative_vec(
; CHECK-NEXT: [[FABS:%.*]] = tail call <2 x double> @llvm.fabs.v2f64(<2 x double> [[X:%.*]])
; CHECK-NEXT: [[CMP:%.*]] = fcmp nnan ult <2 x double> [[FABS]], zeroinitializer
; CHECK-NEXT: ret <2 x i1> [[CMP]]
; CHECK-NEXT: ret <2 x i1> zeroinitializer
;
%fabs = tail call <2 x double> @llvm.fabs.v2f64(<2 x double> %x)
%cmp = fcmp nnan ult <2 x double> %fabs, zeroinitializer