use constants to generate less llvm-ir for raw_vec functions #77068
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Outdated suggestions cannot be applied.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.
as a continuation of #72013 to make RawVec::grow smaller I tried to use constants.
I can see that grow_amortized generate 13% less llvm-Ir and in total 3% less llvm-ir is generated for rustc_middle
but maybe the constant calculations is more time then is saved in llvm.
can I get a perf run?