[llvm] [InstCombine] Fold xored one-complemented operand comparisons (PR #69882)

[Yingwei Zheng via llvm-commits]

================
@@ -7032,6 +7032,22 @@ Instruction *InstCombinerImpl::visitICmpInst(ICmpInst &I) {
       return new ICmpInst(I.getInversePredicate(), Builder.CreateAnd(X, Y),
                           Op1);
 
+    // Transform (~X ^ Y) s< ~Z  --> (X ^ Y) s> Z,
+    //           (~X ^ Y) s> ~Z  --> (X ^ Y) s< Z,
+    //           (~X ^ Y) s<= ~Z --> (X ^ Y) s>= Z,
+    //           (~X ^ Y) s>= ~Z --> (X ^ Y) s<= Z,
+    //           (~X ^ Y) u< ~Z  --> (X ^ Y) u< Z,
+    //           (~X ^ Y) u> ~Z  --> (X ^ Y) u< Z,
+    //           (~X ^ Y) u<= ~Z --> (X ^ Y) u>= Z,
+    //           (~X ^ Y) u>= ~Z --> (X ^ Y) <= Z,
+    //           (~X ^ Y) == ~Z  --> (X ^ Y) != Z,
+    // and       (~X ^ Y) != ~Z  --> (X ^ Y) == Z,
----------------
dtcxzyw wrote:

```suggestion
    //           (~X ^ Y) u>= ~Z --> (X ^ Y) u<= Z,
    //           (~X ^ Y) == ~Z  --> (X ^ Y) == Z,
    // and       (~X ^ Y) != ~Z  --> (X ^ Y) != Z,
```


https://github.com/llvm/llvm-project/pull/69882