[PATCH] D138542: [InstSimplify] Use dominate condtion to simplify xor/sub

[Sanjay Patel via Phabricator via llvm-commits]

spatel added a comment.

There's a question of where this kind of transform belongs - CVP, SCCP?

This seems fine to me, but it should probably be split off into a helper function. We could do the same for srem/urem? sdiv/udiv with a slight adjustment? any other opcodes?



================
Comment at: llvm/test/Transforms/InstSimplify/domcondition.ll:36
+; CHECK:       cond.end:
+; CHECK-NEXT:    ret i32 0
+;
----------------
Something went wrong - this should not simplify?


================
Comment at: llvm/test/Transforms/InstSimplify/domcondition.ll:68
+cond.true:
+  %xor = xor i32 %x, %y
+  %mul = mul i32 %xor, %x
----------------
xor -> sub?


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