Backport 12.0.1 to release_12x #96
Closed
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
|
I'm not sure why GitHub complains that the branch cannot be rebased. It is already based on |
|
We probably need to push these commits to the target branch by hand. According to the following discussion, there is no workaround for this GitHub limitation: https://github.community/t/weird-problem-with-cannot-be-rebased-due-to-conflicts/178433 |
|
We will wave the review. @bryanpkc will merge this. |
bryanpkc
pushed a commit
that referenced
this pull request
Apr 20, 2022
This patch implemented TTI.IntImmCost() properly. Each BPF insn has 32bit immediate space, so for any immediate which can be represented as 32bit signed int, the cost is technically free. If an int cannot be presented as a 32bit signed int, a ld_imm64 instruction is needed and a TCC_Basic is returned. This change is motivated when we observed that several bpf selftests failed with latest llvm trunk, e.g., #10/16 strobemeta.o:FAIL #10/17 strobemeta_nounroll1.o:FAIL #10/18 strobemeta_nounroll2.o:FAIL #10/19 strobemeta_subprogs.o:FAIL #96 snprintf_btf:FAIL The reason of the failure is due to that SpeculateAroundPHIsPass did aggressive transformation which alters control flow for which currently verifer cannot handle well. In llvm12, SpeculateAroundPHIsPass is not called. SpeculateAroundPHIsPass relied on TTI.getIntImmCost() and TTI.getIntImmCostInst() for profitability analysis. This patch implemented TTI.getIntImmCost() properly for BPF backend which also prevented transformation which caused the above test failures. Differential Revision: https://reviews.llvm.org/D96448 (cherry picked from commit a260ae7)
bryanpkc
force-pushed
the
backport-12.0.1
branch
from
bd053ae to
c3acb45
Compare
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.
Backport recent fixes from LLVM 12.0.1 to the
release_12xbranch. This should fix issue #91.I also cherry-picked 54f059c to prevent OpenMP tests from failing when LLVM is built in Debug mode.