[PowerPC] Extend folding RLWINM + RLWINM to post-RA. #67293
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
CI is failing, please check. |
nemanjai
reviewed
Oct 12, 2023
| @@ -160,8 +160,7 @@ define i32 @xvtdivdp_shift(<2 x double> %a, <2 x double> %b) { | |||
| ; CHECK: # %bb.0: # %entry | |||
| ; CHECK-NEXT: xvtdivdp cr0, v2, v3 | |||
| ; CHECK-NEXT: mfocrf r3, 128 | |||
| ; CHECK-NEXT: srwi r3, r3, 28 | |||
| ; CHECK-NEXT: rlwinm r3, r3, 28, 31, 31 | |||
| ; CHECK-NEXT: li r3, 0 | |||
There was a problem hiding this comment.
This is less than ideal. We seem to be able to prove that the result of the xvtdivdp is unused, but we don't eliminate it or the move from CR - both expensive instructions.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This PR is migrated from Phabricator https://reviews.llvm.org/D89855.
We have patterns folding 2 RLWINMs in ppc-mi-peephole, while some RLWINM will be generated after RA, for example rGc4690b007743. We expect the optimization will also be performed for the RLWINM generated after RA followed by another RLWINM.