[ValueTracking] Add missing op checks in computeKnownFPClassFromCond

Author: dtcxzyw

llvm/lib/Analysis/ValueTracking.cpp

@@ -4906,10 +4906,10 @@ static void computeKnownFPClassFromCond(const Value *V, Value *Cond,
     if (CmpVal == V)
       KnownFromContext.knownNot(~(CondIsTrue ? MaskIfTrue : MaskIfFalse));
   } else if (match(Cond, m_Intrinsic<Intrinsic::is_fpclass>(
-                             m_Value(LHS), m_ConstantInt(ClassVal)))) {
+                             m_Specific(V), m_ConstantInt(ClassVal)))) {
     FPClassTest Mask = static_cast<FPClassTest>(ClassVal);
     KnownFromContext.knownNot(CondIsTrue ? ~Mask : Mask);
-  } else if (match(Cond, m_ICmp(Pred, m_ElementWiseBitCast(m_Value(LHS)),
+  } else if (match(Cond, m_ICmp(Pred, m_ElementWiseBitCast(m_Specific(V)),
                                 m_APInt(RHS)))) {
     bool TrueIfSigned;
     if (!isSignBitCheck(Pred, *RHS, TrueIfSigned))

llvm/test/Transforms/InstCombine/fpclass-from-dom-cond.ll

@@ -467,7 +467,9 @@ define i1 @pr118257(half %v0, half %v1) {
 ; CHECK-NEXT:    [[OR_COND:%.*]] = or i1 [[CMP1]], [[CMP2]]
 ; CHECK-NEXT:    br i1 [[OR_COND]], label [[IF_END:%.*]], label [[IF_ELSE:%.*]]
 ; CHECK:       if.else:
-; CHECK-NEXT:    ret i1 false
+; CHECK-NEXT:    [[CAST1:%.*]] = bitcast half [[V1]] to i16
+; CHECK-NEXT:    [[CMP3:%.*]] = icmp slt i16 [[CAST1]], 0
+; CHECK-NEXT:    ret i1 [[CMP3]]
 ; CHECK:       if.end:
 ; CHECK-NEXT:    ret i1 false
 ;
@@ -496,7 +498,9 @@ define i1 @pr118257_is_fpclass(half %v0, half %v1) {
 ; CHECK-NEXT:    [[OR_COND:%.*]] = or i1 [[CMP1]], [[CMP2]]
 ; CHECK-NEXT:    br i1 [[OR_COND]], label [[IF_END:%.*]], label [[IF_ELSE:%.*]]
 ; CHECK:       if.else:
-; CHECK-NEXT:    ret i1 false
+; CHECK-NEXT:    [[CAST1:%.*]] = bitcast half [[V1]] to i16
+; CHECK-NEXT:    [[CMP3:%.*]] = icmp slt i16 [[CAST1]], 0
+; CHECK-NEXT:    ret i1 [[CMP3]]
 ; CHECK:       if.end:
 ; CHECK-NEXT:    ret i1 false
 ;