[PATCH] D136169: [AMDGPU] Avoid SCC clobbering before S_CSELECT_B32

[Alexander via Phabricator via llvm-commits]

alex-t added a comment.

In fact, to avoid this unwanted loop I can use another hack - just forward scavenger one position to look up the SCC liveness at the insertion slot and then immediately backward scavenger to restore its position and avoid breaking the PEI logic.
This looks weird but avoids the loop.
Also, this approach still allows some amount of false positives and, hence, some unnecessary SCC saves/restores.
Will, see what I can do to further improve it.


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https://reviews.llvm.org/D136169