Summary:
There was a bug with sequences like
s_mov_b64 s[0:1], exec
s_and_b64 s[2:3]<def>, s[0:1], s[2:3]<kill>
...
s_mov_b64_term exec, s[2:3]
because s[2:3] was defined and used in the same instruction, ending up with
SaveExecInst inside OtherUseInsts.
Note that the test case also exposes an unrelated bug.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98028
Reviewers: tstellarAMD, arsenm
Subscribers: kzhuravl, wdng, yaxunl, llvm-commits, tony-tye
Differential Revision: https://reviews.llvm.org/D25306
llvm-svn: 283528
Fixes to allow spilling all registers at the end of the block
work with exec modifications. Don't emit s_and_saveexec_b64 for
if lowering, and instead emit copies. Mark control flow mask
instructions as terminators to get correct spill code placement
with fast regalloc, and then have a separate optimization pass
form the saveexec.
This should work if SGPRs are spilled to VGPRs, but
will likely fail in the case that an SGPR spills to memory
and no workitem takes a divergent branch.
llvm-svn: 282667
Nicolai Haehnle