[PATCH] D40307: [MachineCombiner] Add up latencies of all instructions in new pattern.

[Florian Hahn via Phabricator via llvm-commits]

fhahn added a comment.

I ran into this being a problem in https://reviews.llvm.org/D40306. The patterns added there are are not profitable on Cortex-A57, but because the NewRootLatency is under-estimated, the unprofitable pattern gets applied.


https://reviews.llvm.org/D40307