[PATCH] D154306: [InstCombine] Generalise ((x1 ^ y1) | (x2 ^ y2)) == 0 transform to more than two pairs of variables

[Noah Goldstein via Phabricator via llvm-commits]

goldstein.w.n added inline comments.


================
Comment at: llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp:2060
+
+    auto *BO = dyn_cast<BinaryOperator>(OrOp0);
+    if (BO && BO->getOpcode() == BinaryOperator::Or) {
----------------
Shouldn't we also be able to chase OrOp1 (if it doesn't match `Xor`).

Figure it should be something along the lines of:
```
if(match(Op0, Xor) && match(Op1, Xor)) {
 // Base Case
}
else if(match(Op0, Xor)) {
 // Chase Op1
}
else if(match(Op1, Xor)) {
 // Chase Op1
}
else {
 break;
}
```


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D154306/new/

https://reviews.llvm.org/D154306