[llvm] [ValueTracking] Check both operands for being 0 and then the other for isKnownNonZero (PR #147330)

[Nikita Popov via llvm-commits]

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@@ -3892,6 +3893,12 @@ static bool isKnownNonEqual(const Value *V1, const Value *V2,
   if (Depth >= MaxAnalysisRecursionDepth)
     return false;
 
+  // 0 vs known-non-zero
+  if (match(V1, m_Zero()) && isKnownNonZero(V2, DemandedElts, Q, Depth + 1))
+    return true;
+  if (match(V2, m_Zero()) && isKnownNonZero(V1, DemandedElts, Q, Depth + 1))
+    return true;
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nikic wrote:

I don't think this makes sense. x - 0 is just x and should get folded away.

https://github.com/llvm/llvm-project/pull/147330