On 04/08/2025 22:18, Richard Henderson wrote:
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.
---
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 096c853af7f..2b3610c86ed 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. */
ok
