[PATCH] D51849: [RegisterCoalescer] Avoid "Use not jointly dominated by defs" in removePartialRedundancy

[Tim Renouf via Phabricator via llvm-commits]

tpr added a comment.

1. That test only fails without this fix if you have the fix in https://reviews.llvm.org/D51257.

2. I finally tracked down why I couldn't get a mir test before: Compiling a ll file as usual, arriving at RegisterCoalescer, the numbering of the MBBs was not quite in order. Using -stop-before names the MBBs in the mir according to those out-of-order numbers, but reading the mir in again with -run-pass fails to preserve it. Instead it renumbers the MBBs in order. RegisterCoalescing processes MBBs with the same loop depth and critical edgeness and connectedness in numbering order, so the pass behaved differently.


Repository:
  rL LLVM

https://reviews.llvm.org/D51849