aarch64: Support FEAT_LSFE #201
Open
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
taiki-e
added
the
O-aarch64
taiki-e
force-pushed
the
main
branch
5 times, most recently
from
53c8409 to
378f6cd
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Outdated suggestions cannot be applied.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.
Armv9.6 added atomic float instructions for binary{16,32,64} and bfloat16 as FEAT_LSFE (Large System Float Extension).
This PR optimizes AArch64 {16,32,64}-bit atomic float add/sub/max/min when FEAT_LSFE is enabled.
LLVM's assembly support for FEAT_LSFE needs LLVM 20 (llvm/llvm-project@67ff5ba), so use .inst directive on LLVM 19 or older.
Run-time detection is also implemented, but at this time it is only used in testing. AFAIK no CPUs actually implement this feature yet, so we will only refer to the feature available at compile time at this time.