morello atomic: Trim gcvalue from the spin loop of arithmetic atomics #2249
+3
−5
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
Use a ptraddr_t as the input that can be assigned to the register constraint as is done for RISC-V. This allows the compiler to either hoist the gcvalue out of the loop, or to just use the x portion of the relevant register.
bsdjhb
commented
Nov 16, 2024
| @@ -667,21 +667,19 @@ static __inline void \ | |||
| atomic_##op##_##bar##ptr(volatile uintptr_t *p, uintptr_t val) \ | |||
| { \ | |||
| uintptr_t previous; \ | |||
| ptraddr_t tmp1, tmp2; \ | |||
| ptraddr_t tmp; \ | |||
| int res; \ | |||
| \ | |||
| __asm __volatile( \ | |||
| "1:" \ | |||
| "ld" #a "xr %0, [%4]\n" \ | |||
| "gcvalue %2, %0\n" \ | |||
There was a problem hiding this comment.
This could be eliminated if there was an equivalent to %wN to denote the X version of the C register as then we could use that as the second operand in the scvalue instruction below.
jrtc27
approved these changes
Nov 20, 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Outdated suggestions cannot be applied.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.
Use a ptraddr_t as the input that can be assigned to the register
constraint as is done for RISC-V. This allows the compiler to either
hoist the gcvalue out of the loop, or to just use the x portion of the
relevant register.