[PATCH] D35195: [WIP][PowerPC] run additional InstCombine pass after PPCCTRLoop pass

[Hal Finkel via Phabricator via llvm-commits]

hfinkel added a comment.

I'm not worried here about compile time, there's a different problem, however. If you run InstCombine after CGP, it will likely undo things that CGP does (such as sinking things, splitting things, etc. - a bunch of anti-canonical transformations). How much this matters for us I'm not sure, we'd need to audit. If this is just about eliminating dead code, does running something like ADCE take care of it?

It would certainly be interesting to describe what other code-quality improvements have shown up by doing this (in other test cases, etc.).

Regardless, this needs a test case.


https://reviews.llvm.org/D35195