[llvm] [InstSimplify] Simplify the expression `(a^c)&(a^~c)` to zero (PR #76637)

[Nikita Popov via llvm-commits]

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@@ -2204,6 +2204,13 @@ static Value *simplifyAndInst(Value *Op0, Value *Op1, const SimplifyQuery &Q,
       match(Op1, m_c_Xor(m_Specific(Or), m_Specific(Y))))
     return Constant::getNullValue(Op0->getType());
 
+  const APInt *C1, *C2;
+  Value *A;
+  // (A ^ C) & (A ^ ~C) -> 0
+  if (match(Op0, m_Xor(m_Value(A), m_APInt(C1))) &&
+      match(Op1, m_Xor(m_Specific(A), m_APInt(C2))) && (*C1 ^ *C2).isAllOnes())
----------------
nikic wrote:

```suggestion
      match(Op1, m_Xor(m_Specific(A), m_SpecificInt(~*C1))))
```

https://github.com/llvm/llvm-project/pull/76637