[PATCH] D33572: [PPC CodeGen] Expand the bitreverse.i32 intrinsic.

[Nemanja Ivanovic via Phabricator via llvm-commits]

nemanjai added a comment.

In https://reviews.llvm.org/D33572#794182, @hfinkel wrote:

> In https://reviews.llvm.org/D33572#794146, @jtony wrote:
>
> > Address comments from Hal Finkel and add one more IR test case to test the original situation in Bugzilla (the IR is equivalent form of fast bit-reverse but NOT the intrinsic).
>
>
> So, we don't currently recognize the 32-bit version as a bit permutation in 64-bit mode? Otherwise, we'd end up in the same situation as the PR and the test would fail right now, right?


I think that the point that needs to be mentioned in this patch is that idiom recognition will fire now that we've legalized `ISD::BITREVERSE` and we will not consider this for the bit permutation handling. Namely, what we'll have in the SDAG is just the `ISD::BITREVERSE` node.


https://reviews.llvm.org/D33572