ValueTracking: Fix computeKnownFPClass handling for copysign

[arsenm]

Summary

We need to expand the set of possible classes to the opposite
sign for the first operand if we don't know the sign of the second
operand.

[arsenm]

Something's broken with -0

[foad]

llvm/include/llvm/Analysis/ValueTracking.h

399–402

This doesn't work. Sign.isKnownNever(fcPositive) does not guarantee that the sign bit of Sign is 1, since it could be a nan with the sign bit clear.

I guess you meant Sign.isKnownNever(fcPositive | fcNan)? But this is another case where you could test Sign.SignBit && *Sign.SignBit as well or instead, since there is redundancy in the representation.

[foad]

llvm/include/llvm/Analysis/ValueTracking.h

403

How do you know the result is not nan?

[arsenm]

llvm/include/llvm/Analysis/ValueTracking.h

403

You don’t. This is avoiding clearing the bits that say it could be nan

[arsenm]

0125b8d2ecd39fabb7c735624d5f8d2be3dd7356

llvm/include/llvm/Analysis/ValueTracking.h

struct KnownFPClass {
 
   /// Assume the sign bit is zero.
   void signBitMustBeZero() {
     KnownFPClasses &= (fcPositive | fcNan);
     SignBit = false;
   }
 
   void copysign(const KnownFPClass &Sign) {
-    // Start assuming nothing about the sign.
+    // Don't know anything about the sign of the source. Expand the possible set
+    // to its opposite sign pair.
+    if (KnownFPClasses & fcZero)
+      KnownFPClasses |= fcZero;
+    if (KnownFPClasses & fcSubnormal)
+      KnownFPClasses |= fcSubnormal;
+    if (KnownFPClasses & fcNormal)
+      KnownFPClasses |= fcNormal;
+    if (KnownFPClasses & fcInf)
+      KnownFPClasses |= fcInf;
+
+    // Sign bit is exactly preserved even for nans.
     SignBit = Sign.SignBit;
-    if (!SignBit)
-      return;
 
-    if (*SignBit)
-      KnownFPClasses = KnownFPClasses & fcNegative;
-    else
-      KnownFPClasses = KnownFPClasses & fcPositive;
+    // Clear sign bits based on the input sign mask.
+    if (Sign.isKnownNever(fcPositive | fcNan) || (SignBit && *SignBit))
+      KnownFPClasses &= (fcNegative | fcNan);
+    if (Sign.isKnownNever(fcNegative | fcNan) || (SignBit && !*SignBit))
+      KnownFPClasses &= (fcPositive | fcNan);
   }
 
   // Propagate knowledge that a non-NaN source implies the result can also not
   // be a NaN. For unconstrained operations, signaling nans are not guaranteed
   // to be quieted but cannot be introduced.
   void propagateNaN(const KnownFPClass &Src, bool PreserveSign = false) {
     if (Src.isKnownNever(fcNan)) {
       knownNot(fcNan);

llvm/test/Transforms/Attributor/nofpclass-copysign.ll

 ; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2:[0-9]+]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
 define float @ret_copysign_fabs_rhs(float %arg0, float %arg1) {
-; CHECK-LABEL: define nofpclass(nan ninf nzero nsub nnorm) float @ret_copysign_fabs_rhs
+; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) float @ret_copysign_fabs_rhs
 ; CHECK-SAME: (float [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
 ; CHECK-NEXT:    [[FABS_ARG1:%.*]] = call float @llvm.fabs.f32(float [[ARG1]]) #[[ATTR2]]
-; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(nan ninf nzero nsub nnorm) float @llvm.copysign.f32(float [[ARG0]], float [[FABS_ARG1]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(ninf nzero nsub nnorm) float @llvm.copysign.f32(float [[ARG0]], float [[FABS_ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %fabs.arg1 = call float @llvm.fabs.f32(float %arg1)
   %call = call float @llvm.copysign.f32(float %arg0, float %fabs.arg1)
   ret float %call
 }
 
 define float @ret_copysign_nnan_lhs_fabs_rhs(float nofpclass(nan) %arg0, float %arg1) {
 ; CHECK-LABEL: define nofpclass(nan ninf nzero nsub nnorm) float @ret_copysign_nnan_lhs_fabs_rhs
 ; CHECK-SAME: (float nofpclass(nan) [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
 ; CHECK-NEXT:    [[FABS_ARG1:%.*]] = call float @llvm.fabs.f32(float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(nan ninf nzero nsub nnorm) float @llvm.copysign.f32(float [[ARG0]], float [[FABS_ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %fabs.arg1 = call float @llvm.fabs.f32(float %arg1)
   %call = call float @llvm.copysign.f32(float %arg0, float %fabs.arg1)
   ret float %call
 }
 
 
 define float @ret_copysign_lhs_fabs_nnan_rhs(float %arg0, float %arg1) {
-; CHECK-LABEL: define nofpclass(nan ninf nzero nsub nnorm) float @ret_copysign_lhs_fabs_nnan_rhs
+; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) float @ret_copysign_lhs_fabs_nnan_rhs
 ; CHECK-SAME: (float [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
 ; CHECK-NEXT:    [[FABS_ARG1:%.*]] = call nnan float @llvm.fabs.f32(float [[ARG1]]) #[[ATTR2]]
-; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(nan ninf nzero nsub nnorm) float @llvm.copysign.f32(float [[ARG0]], float [[FABS_ARG1]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(ninf nzero nsub nnorm) float @llvm.copysign.f32(float [[ARG0]], float [[FABS_ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %fabs.arg1 = call nnan float @llvm.fabs.f32(float %arg1)
   %call = call float @llvm.copysign.f32(float %arg0, float %fabs.arg1)
   ret float %call
 }
 
 
 define float @ret_copysign_noneg_lhs(float nofpclass(ninf nnorm nsub nzero) %arg0, float %arg1) {
-; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) float @ret_copysign_noneg_lhs
+; CHECK-LABEL: define float @ret_copysign_noneg_lhs
 ; CHECK-SAME: (float nofpclass(ninf nzero nsub nnorm) [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(ninf nzero nsub nnorm) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
 define float @ret_copysign_noneg_rhs(float %arg0, float nofpclass(ninf nnorm nsub nzero) %arg1) {
 ; CHECK-LABEL: define float @ret_copysign_noneg_rhs
 ; CHECK-SAME: (float [[ARG0:%.*]], float nofpclass(ninf nzero nsub nnorm) [[ARG1:%.*]]) #[[ATTR1]] {
 ; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
+define float @ret_copysign_noneg_nonan_rhs(float %arg0, float nofpclass(ninf nnorm nsub nzero nan) %arg1) {
+; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) float @ret_copysign_noneg_nonan_rhs
+; CHECK-SAME: (float [[ARG0:%.*]], float nofpclass(nan ninf nzero nsub nnorm) [[ARG1:%.*]]) #[[ATTR1]] {
+; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(ninf nzero nsub nnorm) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
+; CHECK-NEXT:    ret float [[CALL]]
+;
+  %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
+  ret float %call
+}
+
 define float @ret_copysign_nopos_lhs(float nofpclass(pinf pnorm psub pzero) %arg0, float %arg1) {
-; CHECK-LABEL: define nofpclass(pinf pzero psub pnorm) float @ret_copysign_nopos_lhs
+; CHECK-LABEL: define float @ret_copysign_nopos_lhs
 ; CHECK-SAME: (float nofpclass(pinf pzero psub pnorm) [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(pinf pzero psub pnorm) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
 define float @ret_copysign_nopos_rhs(float %arg0, float nofpclass(pinf pnorm psub pzero) %arg1) {
 ; CHECK-LABEL: define float @ret_copysign_nopos_rhs

 ; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
 define float @ret_copysign_noneg_nonan_lhs(float nofpclass(ninf nnorm nsub nzero nan) %arg0, float %arg1) {
-; CHECK-LABEL: define nofpclass(nan ninf nzero nsub nnorm) float @ret_copysign_noneg_nonan_lhs
+; CHECK-LABEL: define nofpclass(nan) float @ret_copysign_noneg_nonan_lhs
 ; CHECK-SAME: (float nofpclass(nan ninf nzero nsub nnorm) [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(nan ninf nzero nsub nnorm) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(nan) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
 define float @ret_copysign_nopos_nonan_lhs(float nofpclass(pinf pnorm psub pzero nan) %arg0, float %arg1) {
-; CHECK-LABEL: define nofpclass(nan pinf pzero psub pnorm) float @ret_copysign_nopos_nonan_lhs
+; CHECK-LABEL: define nofpclass(nan) float @ret_copysign_nopos_nonan_lhs
 ; CHECK-SAME: (float nofpclass(nan pinf pzero psub pnorm) [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(nan pinf pzero psub pnorm) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(nan) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
 define float @ret_copysign_mixed_lhs0(float nofpclass(ninf pnorm nsub nzero) %arg0, float %arg1) {
-; CHECK-LABEL: define nofpclass(ninf nzero nsub pnorm) float @ret_copysign_mixed_lhs0
+; CHECK-LABEL: define float @ret_copysign_mixed_lhs0
 ; CHECK-SAME: (float nofpclass(ninf nzero nsub pnorm) [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(ninf nzero nsub pnorm) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
 define float @ret_copysign_mixed_lhs1(float nofpclass(pinf nnorm psub pzero) %arg0, float %arg1) {
-; CHECK-LABEL: define nofpclass(pinf pzero psub nnorm) float @ret_copysign_mixed_lhs1
+; CHECK-LABEL: define float @ret_copysign_mixed_lhs1
 ; CHECK-SAME: (float nofpclass(pinf pzero psub nnorm) [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(pinf pzero psub nnorm) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
 define float @ret_copysign_mixed_lhs2(float nofpclass(ninf pnorm psub nzero qnan) %arg0, float %arg1) {
-; CHECK-LABEL: define nofpclass(qnan ninf nzero psub pnorm) float @ret_copysign_mixed_lhs2
+; CHECK-LABEL: define nofpclass(qnan) float @ret_copysign_mixed_lhs2
 ; CHECK-SAME: (float nofpclass(qnan ninf nzero psub pnorm) [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(qnan ninf nzero psub pnorm) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(qnan) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
 define float @ret_copysign_noninf_lhs(float nofpclass(ninf) %arg0, float %arg1) {
-; CHECK-LABEL: define nofpclass(ninf) float @ret_copysign_noninf_lhs
+; CHECK-LABEL: define float @ret_copysign_noninf_lhs
 ; CHECK-SAME: (float nofpclass(ninf) [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(ninf) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
 define float @ret_copysign_nopinf_lhs(float nofpclass(pinf) %arg0, float %arg1) {
-; CHECK-LABEL: define nofpclass(pinf) float @ret_copysign_nopinf_lhs
+; CHECK-LABEL: define float @ret_copysign_nopinf_lhs
 ; CHECK-SAME: (float nofpclass(pinf) [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(pinf) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
 define float @ret_copysign_noinf_lhs(float nofpclass(inf) %arg0, float %arg1) {
 ; CHECK-LABEL: define nofpclass(inf) float @ret_copysign_noinf_lhs
 ; CHECK-SAME: (float nofpclass(inf) [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
 ; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(inf) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
 define float @ret_copysign_nonzero_lhs(float nofpclass(nzero) %arg0, float %arg1) {
-; CHECK-LABEL: define nofpclass(nzero) float @ret_copysign_nonzero_lhs
+; CHECK-LABEL: define float @ret_copysign_nonzero_lhs
 ; CHECK-SAME: (float nofpclass(nzero) [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(nzero) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
 define float @ret_copysign_nopzero_lhs(float nofpclass(pzero) %arg0, float %arg1) {
-; CHECK-LABEL: define nofpclass(pzero) float @ret_copysign_nopzero_lhs
+; CHECK-LABEL: define float @ret_copysign_nopzero_lhs
 ; CHECK-SAME: (float nofpclass(pzero) [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(pzero) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
 define float @ret_copysign_nozero_lhs(float nofpclass(zero) %arg0, float %arg1) {
 ; CHECK-LABEL: define nofpclass(zero) float @ret_copysign_nozero_lhs
 ; CHECK-SAME: (float nofpclass(zero) [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
 ; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(zero) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
 define float @ret_copysign_nonsub_lhs(float nofpclass(nsub) %arg0, float %arg1) {
-; CHECK-LABEL: define nofpclass(nsub) float @ret_copysign_nonsub_lhs
+; CHECK-LABEL: define float @ret_copysign_nonsub_lhs
 ; CHECK-SAME: (float nofpclass(nsub) [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(nsub) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
 define float @ret_copysign_nopsub_lhs(float nofpclass(psub) %arg0, float %arg1) {
-; CHECK-LABEL: define nofpclass(psub) float @ret_copysign_nopsub_lhs
+; CHECK-LABEL: define float @ret_copysign_nopsub_lhs
 ; CHECK-SAME: (float nofpclass(psub) [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(psub) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
 define float @ret_copysign_nosub_lhs(float nofpclass(sub) %arg0, float %arg1) {
 ; CHECK-LABEL: define nofpclass(sub) float @ret_copysign_nosub_lhs
 ; CHECK-SAME: (float nofpclass(sub) [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
 ; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(sub) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
 define float @ret_copysign_nonnorm_lhs(float nofpclass(nnorm) %arg0, float %arg1) {
-; CHECK-LABEL: define nofpclass(nnorm) float @ret_copysign_nonnorm_lhs
+; CHECK-LABEL: define float @ret_copysign_nonnorm_lhs
 ; CHECK-SAME: (float nofpclass(nnorm) [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(nnorm) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
 define float @ret_copysign_nopnorm_lhs(float nofpclass(pnorm) %arg0, float %arg1) {
-; CHECK-LABEL: define nofpclass(pnorm) float @ret_copysign_nopnorm_lhs
+; CHECK-LABEL: define float @ret_copysign_nopnorm_lhs
 ; CHECK-SAME: (float nofpclass(pnorm) [[ARG0:%.*]], float [[ARG1:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(pnorm) float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.copysign.f32(float [[ARG0]], float [[ARG1]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.copysign.f32(float %arg0, float %arg1)
   ret float %call
 }
 
 define float @ret_copysign_nonorm_lhs(float nofpclass(norm) %arg0, float %arg1) {
 ; CHECK-LABEL: define nofpclass(norm) float @ret_copysign_nonorm_lhs

llvm/unittests/Analysis/ValueTrackingTest.cpp

TEST_F(ComputeKnownFPClassTest, CopySignNNanSrc0) {
   parseAssembly(
       "declare float @llvm.fabs.f32(float)\n"
       "declare float @llvm.copysign.f32(float, float)\n"
       "define float @test(float %arg0, float %arg1) {\n"
       "  %fabs = call nnan float @llvm.fabs.f32(float %arg0)"
       "  %A = call float @llvm.copysign.f32(float %fabs, float %arg1)"
       "  ret float %A\n"
       "}\n");
-  expectKnownFPClass(fcPositive, std::nullopt);
+  expectKnownFPClass(~fcNan, std::nullopt);
 }
 
 TEST_F(ComputeKnownFPClassTest, CopySignNInfSrc0_NegSign) {
   parseAssembly(
       "declare float @llvm.log.f32(float)\n"
       "declare float @llvm.copysign.f32(float, float)\n"
       "define float @test(float %arg0, float %arg1) {\n"
       "  %ninf = call ninf float @llvm.log.f32(float %arg0)"
       "  %A = call float @llvm.copysign.f32(float %ninf, float -1.0)"
       "  ret float %A\n"
       "}\n");
-  expectKnownFPClass(fcNegFinite, true);
+  expectKnownFPClass(fcNegFinite | fcNan, true);
 }
 
 TEST_F(ComputeKnownFPClassTest, CopySignNInfSrc0_PosSign) {
   parseAssembly(
       "declare float @llvm.sqrt.f32(float)\n"
       "declare float @llvm.copysign.f32(float, float)\n"
       "define float @test(float %arg0, float %arg1) {\n"
       "  %ninf = call ninf float @llvm.sqrt.f32(float %arg0)"
       "  %A = call float @llvm.copysign.f32(float %ninf, float 1.0)"
       "  ret float %A\n"
       "}\n");
-  expectKnownFPClass(fcPosFinite, false);
+  expectKnownFPClass(fcPosFinite | fcNan, false);
 }
 
 TEST_F(ComputeKnownFPClassTest, UIToFP) {
   parseAssembly(
       "define float @test(i32 %arg0, i16 %arg1) {\n"
       "  %A = uitofp i32 %arg0 to float"
       "  %A2 = uitofp i16 %arg1 to half"
       "  ret float %A\n"