Commit Graph

2 Commits

Author SHA1 Message Date
Matt Arsenault fee41517fe AMDGPU/GlobalISel: Introduce post-legalize combiner
The current set of custom combines are only really useful after
legalization, so move them there. There is a lot of overlap in the
boilerplate here, but I think we do want a pretty different set of
combines before and after legalize. I think we will want a lot of
overlap between the post-legalize and a post-regbankselect combiner.
2020-02-24 22:12:12 -05:00
Matt Arsenault 96db12d507 AMDGPU/GlobalISel: Custom lower 32-bit G_UDIV/G_UREM
AMDGPUCodeGenPrepare expands this most of the time, but not always. We
will always at least need a fallback option here. This is the 3rd
implementation of the same expansion in the backend. Eventually I
would like to eliminate the IR expansion (and the DAG version
obviously).

Currently the new legalizer path produces a better result, since the
IR expansion results in extra operations which need to be combined
out. Notably, the IR expansion results in multiplies by 0.
2020-02-17 11:05:50 -08:00