Jit64: divwx - One more micro-optimization #10199
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
Prefer using eax to isolate the sign bit. This saves a byte when the destination ends up as r8-15, because those require a REX prefix. Before: 41 8B C5 mov eax,r13d 41 C1 ED 1F shr r13d,1Fh 44 03 E8 add r13d,eax 41 D1 FD sar r13d,1 After: 41 8B C5 mov eax,r13d C1 E8 1F shr eax,1Fh 44 03 E8 add r13d,eax 41 D1 FD sar r13d,1
Sintendo
force-pushed
the
jit64divwxnits
branch
from
d848830
to
dfb3204
Compare
JosJuice
approved these changes
Nov 3, 2021
lioncash
approved these changes
Nov 3, 2021
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Outdated suggestions cannot be applied.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.
The division by 2 case can be improved ever so slightly by using eax when possible to isolate the sign bit. This saves a byte when the destination ends up as r8-15, because those require a REX prefix.
I also improved the comments a little in this area.
Before:
After: