Compiler: Optimize k*n and k+n when types are known #1529
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
When type information is specified, we can compile k*n and k+n into MULK/ADDK forms that are faster to execute, as long as we think n is a number. Since we generally restrict type aware optimizations to O2, this does that as well. This makes trig benchmark ~4% faster on Apple M2 in VM, and also a tiny improvment on scimark (~0.1%) can be observed. The optimization only affects interpreted execution, as NCG already can synthesize optimal code here. If the type information is not truthful (e.g. user annotates type as a number and it's not), the worst case scenario is flipped arguments to metamethods like __add/__mul for constant left hand side.
vegorov-rbx
reviewed
Nov 19, 2024
vegorov-rbx
approved these changes
Nov 19, 2024
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Outdated suggestions cannot be applied.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.
When type information is specified, we can compile k*n and k+n into MULK/ADDK forms that are faster to execute, as long as we think n is a number. Since we generally restrict type aware optimizations to O2, this does that as well.
This makes trig benchmark ~4% faster on Apple M2 in VM, and also a tiny improvement on scimark (~0.1%) can be observed. The optimization only affects interpreted execution, as NCG already can synthesize optimal code here.
If the type information is not truthful (e.g. user annotates type as a number and it's not), the worst case scenario is flipped arguments to metamethods like __add/__mul for constant left hand side.
Fixes #626 (the fix requires type information or NCG but I doubt any further work on this is warranted)