Fix Clang warning with __builtin_assume #1788
Merged
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
|
Hi there, this is jenkins continuous integration... |
|
launch jenkins |
|
launch perftests |
fthaler
approved these changes
Jun 19, 2024
|
launch jenkins |
|
launch perftests |
|
launch jenkins |
1 similar comment
|
launch jenkins |
|
does it have any effect on perftests? if not, we can merge. |
Looks like: https://jenkins-mch.cscs.ch/job/GridTools/job/GridTools_perftest_PR/326/env=cray,label=daint-cn/Results/ |
|
launch perftest |
havogt
approved these changes
Jun 24, 2024
havogt
pushed a commit
that referenced
this pull request
Jun 26, 2024
Building the project with `Clang` generates the following warning: ``` the argument to '__builtin_assume' has side effects that will be discarded [-Wassume] ``` Seems like Clang doesn't handle the hint well unless we pass a const/pure attribute to the function call inside the assume. See: llvm/llvm-project#55636 and llvm/llvm-project#93077 With this change performance for the fn fused nabla examples is significantly improved on clang-cuda and is now much faster than (our old) nvcc, which doesn't have `assume` support.
# for free
to join this conversation on GitHub.
Already have an account?
# 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Outdated suggestions cannot be applied.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.
Building the project with
Clanggenerates the following warning:Seems like Clang doesn't handle the hint well unless we pass a const/pure attribute to the function call inside the assume. See: llvm/llvm-project#55636 and llvm/llvm-project#93077
With this change performance for the fn fused nabla examples is significantly improved on clang-cuda and is now much faster than (our old) nvcc, which doesn't have
assumesupport.