public inbox for gcc-cvs@sourceware.org
help / color / mirror / Atom feed
* [gcc r13-7666] RISC-V: Enforce atomic compare_exchange SEQ_CST
@ 2023-07-31 16:18 Patrick O'Neill
0 siblings, 0 replies; only message in thread
From: Patrick O'Neill @ 2023-07-31 16:18 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:0180b20de73778fe1e67060f66c7f47630aeb949
commit r13-7666-g0180b20de73778fe1e67060f66c7f47630aeb949
Author: Patrick O'Neill <patrick@rivosinc.com>
Date: Wed Apr 5 09:46:37 2023 -0700
RISC-V: Enforce atomic compare_exchange SEQ_CST
This patch enforces SEQ_CST for atomic compare_exchange ops.
Replace Fence/LR.aq/SC.aq pairs with SEQ_CST LR.aqrl/SC.rl pairs
recommended by table A.6 of the ISA manual.
2023-04-27 Patrick O'Neill <patrick@rivosinc.com>
gcc/ChangeLog:
* config/riscv/sync.md (atomic_cas_value_strong<mode>): Change
FENCE/LR.aq/SC.aq into sequentially consistent LR.aqrl/SC.rl
pair.
Signed-off-by: Patrick O'Neill <patrick@rivosinc.com>
Diff:
---
gcc/config/riscv/sync.md | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/gcc/config/riscv/sync.md b/gcc/config/riscv/sync.md
index 0c83ef04607..5620d6ffa58 100644
--- a/gcc/config/riscv/sync.md
+++ b/gcc/config/riscv/sync.md
@@ -297,9 +297,16 @@
UNSPEC_COMPARE_AND_SWAP))
(clobber (match_scratch:GPR 6 "=&r"))]
"TARGET_ATOMIC"
- "%F5 1: lr.<amo>%A5 %0,%1; bne %0,%z2,1f; sc.<amo>%A4 %6,%z3,%1; bnez %6,1b; 1:"
+ {
+ return "1:\;"
+ "lr.<amo>.aqrl\t%0,%1\;"
+ "bne\t%0,%z2,1f\;"
+ "sc.<amo>.rl\t%6,%z3,%1\;"
+ "bnez\t%6,1b\;"
+ "1:";
+ }
[(set_attr "type" "atomic")
- (set (attr "length") (const_int 20))])
+ (set (attr "length") (const_int 16))])
(define_expand "atomic_compare_and_swap<mode>"
[(match_operand:SI 0 "register_operand" "") ;; bool output
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2023-07-31 16:18 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-07-31 16:18 [gcc r13-7666] RISC-V: Enforce atomic compare_exchange SEQ_CST Patrick O'Neill
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).