[llvm] [ValueTracking] Respect `samesign` flag in `isKnownInversion` (PR #112390)

[Yingwei Zheng via llvm-commits]

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@@ -8526,14 +8526,26 @@ bool llvm::isKnownInversion(const Value *X, const Value *Y) {
       !match(Y, m_c_ICmp(Pred2, m_Specific(A), m_Value(C))))
     return false;
 
+  // If they are only differ in predicate. They must both have samesign flag or
+  // not.
   if (B == C)
-    return Pred1 == ICmpInst::getInversePredicate(Pred2);
+    return Pred1 == ICmpInst::getInversePredicate(Pred2) &&
+           (!cast<ICmpInst>(X)->hasSameSign() ||
+            cast<ICmpInst>(Y)->hasSameSign());
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dtcxzyw wrote:

Agree.

https://github.com/llvm/llvm-project/pull/112390