[InstSimplify] use any-zero matcher for fcmp folds
The m_APFloat matcher does not work with anything but strict
splat vector constants, so we could miss these folds and then
trigger an assertion in instcombine:
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=13201
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354406 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp
index 843b3e9..092aaf6 100644
--- a/lib/Analysis/InstructionSimplify.cpp
+++ b/lib/Analysis/InstructionSimplify.cpp
@@ -3648,6 +3648,31 @@
}
// Handle fcmp with constant RHS.
+ if (match(RHS, m_AnyZeroFP())) {
+ switch (Pred) {
+ case FCmpInst::FCMP_OGE:
+ if (FMF.noNaNs() && CannotBeOrderedLessThanZero(LHS, Q.TLI))
+ return getTrue(RetTy);
+ break;
+ case FCmpInst::FCMP_UGE:
+ 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:
+ if (CannotBeOrderedLessThanZero(LHS, Q.TLI))
+ return getFalse(RetTy);
+ break;
+ default:
+ break;
+ }
+ }
+
+ // TODO: Use match with a specific FP value, so these work with vectors with
+ // undef lanes.
const APFloat *C;
if (match(RHS, m_APFloat(C))) {
// Check whether the constant is an infinity.
@@ -3675,28 +3700,6 @@
break;
}
}
- }
- if (C->isZero()) {
- switch (Pred) {
- case FCmpInst::FCMP_OGE:
- if (FMF.noNaNs() && CannotBeOrderedLessThanZero(LHS, Q.TLI))
- return getTrue(RetTy);
- break;
- case FCmpInst::FCMP_UGE:
- 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:
- if (CannotBeOrderedLessThanZero(LHS, Q.TLI))
- return getFalse(RetTy);
- break;
- default:
- break;
- }
} else if (C->isNegative()) {
assert(!C->isNaN() && "Unexpected NaN constant!");
// TODO: We can catch more cases by using a range check rather than
diff --git a/test/Transforms/InstSimplify/floating-point-compare.ll b/test/Transforms/InstSimplify/floating-point-compare.ll
index 77db052..5ce56e0 100644
--- a/test/Transforms/InstSimplify/floating-point-compare.ll
+++ b/test/Transforms/InstSimplify/floating-point-compare.ll
@@ -399,9 +399,7 @@
define <2 x i1> @fabs_is_not_negative_anyzero(<2 x float> %V) {
; CHECK-LABEL: @fabs_is_not_negative_anyzero(
-; CHECK-NEXT: [[ABS:%.*]] = call <2 x float> @llvm.fabs.v2f32(<2 x float> [[V:%.*]])
-; CHECK-NEXT: [[CMP:%.*]] = fcmp olt <2 x float> [[ABS]], <float 0.000000e+00, float -0.000000e+00>
-; CHECK-NEXT: ret <2 x i1> [[CMP]]
+; CHECK-NEXT: ret <2 x i1> zeroinitializer
;
%abs = call <2 x float> @llvm.fabs.v2f32(<2 x float> %V)
%cmp = fcmp olt <2 x float> %abs, <float 0.0, float -0.0>
@@ -410,9 +408,7 @@
define <3 x i1> @fabs_is_not_negative_negzero_undef(<3 x float> %V) {
; CHECK-LABEL: @fabs_is_not_negative_negzero_undef(
-; CHECK-NEXT: [[ABS:%.*]] = call <3 x float> @llvm.fabs.v3f32(<3 x float> [[V:%.*]])
-; CHECK-NEXT: [[CMP:%.*]] = fcmp olt <3 x float> [[ABS]], <float -0.000000e+00, float -0.000000e+00, float undef>
-; CHECK-NEXT: ret <3 x i1> [[CMP]]
+; CHECK-NEXT: ret <3 x i1> zeroinitializer
;
%abs = call <3 x float> @llvm.fabs.v3f32(<3 x float> %V)
%cmp = fcmp olt <3 x float> %abs, <float -0.0, float -0.0, float undef>
@@ -421,9 +417,7 @@
define <3 x i1> @fabs_is_not_negative_poszero_undef(<3 x float> %V) {
; CHECK-LABEL: @fabs_is_not_negative_poszero_undef(
-; CHECK-NEXT: [[ABS:%.*]] = call <3 x float> @llvm.fabs.v3f32(<3 x float> [[V:%.*]])
-; CHECK-NEXT: [[CMP:%.*]] = fcmp olt <3 x float> [[ABS]], <float 0.000000e+00, float 0.000000e+00, float undef>
-; CHECK-NEXT: ret <3 x i1> [[CMP]]
+; CHECK-NEXT: ret <3 x i1> zeroinitializer
;
%abs = call <3 x float> @llvm.fabs.v3f32(<3 x float> %V)
%cmp = fcmp olt <3 x float> %abs, <float 0.0, float 0.0, float undef>
@@ -432,9 +426,7 @@
define <3 x i1> @fabs_is_not_negative_anyzero_undef(<3 x float> %V) {
; CHECK-LABEL: @fabs_is_not_negative_anyzero_undef(
-; CHECK-NEXT: [[ABS:%.*]] = call <3 x float> @llvm.fabs.v3f32(<3 x float> [[V:%.*]])
-; CHECK-NEXT: [[CMP:%.*]] = fcmp olt <3 x float> [[ABS]], <float 0.000000e+00, float -0.000000e+00, float undef>
-; CHECK-NEXT: ret <3 x i1> [[CMP]]
+; CHECK-NEXT: ret <3 x i1> zeroinitializer
;
%abs = call <3 x float> @llvm.fabs.v3f32(<3 x float> %V)
%cmp = fcmp olt <3 x float> %abs, <float 0.0, float -0.0, float undef>
