[llvm] [ValueTracking] Recognize `X op (X != 0)` as non-zero (PR #88579)

[Yingwei Zheng via llvm-commits]

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@@ -2420,9 +2420,20 @@ static bool isNonZeroRecurrence(const PHINode *PN) {
   }
 }
 
+static bool matchOpWithOpEqZero(Value *Op0, Value *Op1) {
+  ICmpInst::Predicate Pred;
+  return (match(Op0, m_ZExtOrSExt(m_ICmp(Pred, m_Specific(Op1), m_Zero()))) ||
+          match(Op1, m_ZExtOrSExt(m_ICmp(Pred, m_Specific(Op0), m_Zero())))) &&
+         Pred == ICmpInst::ICMP_EQ;
+}
+
 static bool isNonZeroAdd(const APInt &DemandedElts, unsigned Depth,
                          const SimplifyQuery &Q, unsigned BitWidth, Value *X,
                          Value *Y, bool NSW, bool NUW) {
+  // (X + (X != 0)) is non zero
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dtcxzyw wrote:

Yeah, it is a common pattern. But I would like to canonicalize it into `umax(X, 1)` (or vice versa).


https://github.com/llvm/llvm-project/pull/88579