[ValueTracking] Fix a bug for signed min-max clamping

adam-bzowski · adam-bzowski · commit d52fc5ab66d1 · 2024-12-27T06:50:36.000-08:00
This is the fix of the bug present in PR 120576.
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
@@ -1119,8 +1119,7 @@ static void unionWithMinMaxIntrinsicClamp(const IntrinsicInst *II,
                                           KnownBits &Known) {
   const APInt *CLow, *CHigh;
   if (isSignedMinMaxIntrinsicClamp(II, CLow, CHigh))
-    if (!(CLow->isMinSignedValue() && CHigh->isMaxSignedValue()))
-      Known = Known.unionWith(ConstantRange(*CLow, *CHigh + 1).toKnownBits());
+    Known = Known.unionWith(ConstantRange::getNonEmpty(*CLow, *CHigh + 1).toKnownBits());
 }
 
 static void computeKnownBitsFromOperator(const Operator *I,

Original file line number	Diff line number	Diff line change
`@@ -1119,8 +1119,7 @@ static void unionWithMinMaxIntrinsicClamp(const IntrinsicInst *II,`
`1119`	`1119`	`KnownBits &Known) {`
`1120`	`1120`	`const APInt CLow, CHigh;`
`1121`	`1121`	`if (isSignedMinMaxIntrinsicClamp(II, CLow, CHigh))`
`1122`		`- if (!(CLow->isMinSignedValue() && CHigh->isMaxSignedValue()))`
`1123`		`- Known = Known.unionWith(ConstantRange(CLow, CHigh + 1).toKnownBits());`
	`1122`	`+ Known = Known.unionWith(ConstantRange::getNonEmpty(CLow, CHigh + 1).toKnownBits());`
`1124`	`1123`	`}`
`1125`	`1124`
`1126`	`1125`	`static void computeKnownBitsFromOperator(const Operator *I,`