Remove usage of [[likely]] and [[unlikely]]
#5255
Merged
+49
−77
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
GabrielDosReis
approved these changes
Jan 27, 2025
This comment was marked as resolved.
This comment was marked as resolved.
This comment was marked as resolved.
This comment was marked as resolved.
This comment was marked as resolved.
This comment was marked as resolved.
This comment was marked as resolved.
This comment was marked as resolved.
|
I'm mirroring this to the MSVC-internal repo - please notify me if any further changes are pushed. |
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Outdated suggestions cannot be applied.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.
@GabrielDosReis informed me that the optimizer team discourages use of the
[[likely]]and[[unlikely]]attributes, and instead encourages PGO/SPGO. (This aligns with what I've always said, "don't help the compiler".) We've accumulated a fair amount of usage of these attributes, none of which was motivated by benchmarking. Let's remove this noise from our codebase. If we ever find places where it actually affects performance (presumably for Clang/LLVM, since C2 pays minimal attention to the attribute), we can decide what to do.[[likely]]and[[unlikely]]._LIKELY_X86_X64,_LIKELY_ARM_ARM64, and clang-format suppression._LIKELYand_UNLIKELY.