[PATCH] D32563: Add LiveRangeShrink pass to shrink live range within BB.

[Dehao Chen via Phabricator via llvm-commits]

danielcdh added a comment.

Sorry about the regression. As Quentin pointed out, moving instructions close to phi should not be a problem as the algorithm checks the moved instruction uses >1 single-use defs. Looking at the example of the regression case, the transformation looks reasonable if we only consider shrinking live-ranges. Could you provide an IR that I can try reproduce the issue and see why register allocation is worse?

During the mean time, I can prepare a patch to move this to x86-only, or revert the patch if necessary.


https://reviews.llvm.org/D32563