ValueTracking: Update another cannotBeOrderedLessThanZero use

Author: arsenm

llvm/lib/Analysis/InstructionSimplify.cpp

@@ -4204,14 +4204,18 @@ static Value *simplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
   if (match(RHS, m_AnyZeroFP())) {
     switch (Pred) {
     case FCmpInst::FCMP_OGE:
-    case FCmpInst::FCMP_ULT:
+    case FCmpInst::FCMP_ULT: {
+      FPClassTest Interested = FMF.noNaNs() ? fcNegative : fcNegative | fcNan;
+      KnownFPClass Known = computeKnownFPClass(LHS, Q.DL, Interested, 0,
+                                               Q.TLI, Q.AC, Q.CxtI, Q.DT);
+
       // Positive or zero X >= 0.0 --> true
       // Positive or zero X <  0.0 --> false
-      if ((FMF.noNaNs() ||
-           isKnownNeverNaN(LHS, Q.DL, Q.TLI, 0, Q.AC, Q.CxtI, Q.DT)) &&
-          CannotBeOrderedLessThanZero(LHS, Q.DL, Q.TLI))
+      if ((FMF.noNaNs() || Known.isKnownNeverNaN()) &&
+          Known.cannotBeOrderedLessThanZero())
         return Pred == FCmpInst::FCMP_OGE ? getTrue(RetTy) : getFalse(RetTy);
       break;
+    }
     case FCmpInst::FCMP_UGE:
     case FCmpInst::FCMP_OLT:
       // Positive or zero or nan X >= 0.0 --> true

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

@@ -1478,8 +1478,7 @@ define i1 @fcmp_oge_0_assumed_oge_zero(float %x) {
 ; CHECK-LABEL: @fcmp_oge_0_assumed_oge_zero(
 ; CHECK-NEXT:    [[ASSUME_CMP:%.*]] = fcmp oge float [[X:%.*]], 0.000000e+00
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[ASSUME_CMP]])
-; CHECK-NEXT:    [[R:%.*]] = fcmp oge float [[X]], 0.000000e+00
-; CHECK-NEXT:    ret i1 [[R]]
+; CHECK-NEXT:    ret i1 true
 ;
   %assume.cmp = fcmp oge float %x, 0.0
   call void @llvm.assume(i1 %assume.cmp)
@@ -1491,8 +1490,7 @@ define i1 @fcmp_ult_0_assumed_oge_zero(float %x) {
 ; CHECK-LABEL: @fcmp_ult_0_assumed_oge_zero(
 ; CHECK-NEXT:    [[ASSUME_CMP:%.*]] = fcmp oge float [[X:%.*]], 0.000000e+00
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[ASSUME_CMP]])
-; CHECK-NEXT:    [[R:%.*]] = fcmp ult float [[X]], 0.000000e+00
-; CHECK-NEXT:    ret i1 [[R]]
+; CHECK-NEXT:    ret i1 false
 ;
   %assume.cmp = fcmp oge float %x, 0.0
   call void @llvm.assume(i1 %assume.cmp)