The non-LSE pattern aarch64_atomic_exchange<mode> comes before the
LSE pattern aarch64_atomic_exchange<mode>_lse. From a recog
perspective, the only difference between the patterns is that
the non-LSE one clobbers CC and needs a scratch.
However, combine and RTL-SSA can both add clobbers to make a
pattern match. This means that if they try to rerecognise an
LSE pattern, they could end up turning it into a non-LSE pattern.
This patch adds a !TARGET_LSE test to avoid that.
This is needed to avoid a regression with later patches.
Tested on aarch64-linux-gnu & pushed.
Richard
gcc/
* config/aarch64/atomics.md (aarch64_atomic_exchange<mode>): Require
!TARGET_LSE.
---
gcc/config/aarch64/atomics.md | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/gcc/config/aarch64/atomics.md b/gcc/config/aarch64/atomics.md
index 2b6f04efa6c..055a87320ca 100644
--- a/gcc/config/aarch64/atomics.md
+++ b/gcc/config/aarch64/atomics.md
@@ -224,7 +224,7 @@ (define_insn_and_split "aarch64_atomic_exchange<mode>"
UNSPECV_ATOMIC_EXCHG))
(clobber (reg:CC CC_REGNUM))
(clobber (match_scratch:SI 4 "=&r"))]
- ""
+ "!TARGET_LSE"
"#"
"&& epilogue_completed"
[(const_int 0)]
--
2.25.1
