[PATCH] D22247: [DAGCombine] Make sext(setcc) combine respect getBooleanContents()

[Michael Kuperstein via llvm-commits]

mkuper added a comment.

Thanks, Chandler!

Regarding the test case - this is actually somewhat reduced, it's 15 instructions, compared to the 29 in the PR.
The reason it's hard to reduce further is that the graph needs to be set up "just so". The combine opportunity needs to be exposed late (post-legalization), because if it happens too soon, you get an i1 SETCC, which doesn't hit the bad codepath. And I don't know of a way to directly generate an i8 (or larger) SETCC from IR.

I'll make a note of this in the test itself, although I'm not sure how helpful it will be. If the combine chain that leads to this being exposed breaks, there's nothing much you can do about that.


https://reviews.llvm.org/D22247