[PATCH] D52431: [PowerPC] Turn on CR-Logical reducer pass

[Nemanja Ivanovic via Phabricator via llvm-commits]

nemanjai created this revision.
nemanjai added reviewers: hfinkel, echristo, kbarton.
Herald added a subscriber: jsji.

Quite a while ago, we implemented a pass that will reduce the number of CR-logical operations we emit. It does so by converting a CR-logical operation into a branch. We have kept this off by default because it seemed to cause a significant regression with one benchmark.
However, that regression turned out to be due to a completely unrelated reason - AADB introducing a self-copy that is a priority-setting nop and it was just exacerbated by this pass.

Now that we understand the reason for the only degradation, we can turn this pass on by default. A subsequent patch will detect and remove self-copies in the pre-emit peephole.


Repository:
  rL LLVM

https://reviews.llvm.org/D52431

Files:
  lib/Target/PowerPC/PPCTargetMachine.cpp
  test/CodeGen/PowerPC/2008-10-28-f128-i32.ll

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D52431.166729.patch
Type: text/x-patch
Size: 3823 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20180924/828fa1b4/attachment.bin>