https://gcc.gnu.org/g:5a2d86939c735ca2e9aba68c534bffe763a8f7a6
commit r16-3145-g5a2d86939c735ca2e9aba68c534bffe763a8f7a6
Author: Richard Henderson <richard.hender...@linaro.org>
Date: Mon Aug 4 21:47:57 2025 +1000
aarch64: Disable TARGET_CMPBR with aarch64_track_speculation
With -mtrack-speculation, CC_REGNUM must be used at every
conditional branch.
gcc:
* config/aarch64/aarch64.h (TARGET_CMPBR): False when
aarch64_track_speculation is true.
Diff:
---
gcc/config/aarch64/aarch64.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h
index 096c853af7ff..2b3610c86ed5 100644
--- a/gcc/config/aarch64/aarch64.h
+++ b/gcc/config/aarch64/aarch64.h
@@ -410,8 +410,9 @@ constexpr auto AARCH64_FL_DEFAULT_ISA_MODE ATTRIBUTE_UNUSED
/* CSSC instructions are enabled through +cssc. */
#define TARGET_CSSC AARCH64_HAVE_ISA (CSSC)
-/* CB<cc> instructions are enabled through +cmpbr. */
-#define TARGET_CMPBR AARCH64_HAVE_ISA (CMPBR)
+/* CB<cc> instructions are enabled through +cmpbr,
+ but are incompatible with -mtrack-speculation. */
+#define TARGET_CMPBR (AARCH64_HAVE_ISA (CMPBR) && !aarch64_track_speculation)
/* Make sure this is always defined so we don't have to check for ifdefs
but rather use normal ifs. */
