diff options
| -rw-r--r-- | include/qemu/compiler.h | 13 | ||||
| -rw-r--r-- | include/qemu/host-utils.h | 2 |
2 files changed, 14 insertions, 1 deletions
diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h index c2f49df1f9..a309f90c76 100644 --- a/include/qemu/compiler.h +++ b/include/qemu/compiler.h @@ -184,4 +184,17 @@ #define QEMU_DISABLE_CFI #endif +/* + * Apple clang version 14 has a bug in its __builtin_subcll(); define + * BUILTIN_SUBCLL_BROKEN for the offending versions so we can avoid it. + * When a version of Apple clang which has this bug fixed is released + * we can add an upper bound to this check. + * See https://gitlab.com/qemu-project/qemu/-/issues/1631 + * and https://gitlab.com/qemu-project/qemu/-/issues/1659 for details. + * The bug never made it into any upstream LLVM releases, only Apple ones. + */ +#if defined(__apple_build_version__) && __clang_major__ >= 14 +#define BUILTIN_SUBCLL_BROKEN +#endif + #endif /* COMPILER_H */ diff --git a/include/qemu/host-utils.h b/include/qemu/host-utils.h index d3b4dce6a9..011618373e 100644 --- a/include/qemu/host-utils.h +++ b/include/qemu/host-utils.h @@ -649,7 +649,7 @@ static inline uint64_t uadd64_carry(uint64_t x, uint64_t y, bool *pcarry) */ static inline uint64_t usub64_borrow(uint64_t x, uint64_t y, bool *pborrow) { -#if __has_builtin(__builtin_subcll) +#if __has_builtin(__builtin_subcll) && !defined(BUILTIN_SUBCLL_BROKEN) unsigned long long b = *pborrow; x = __builtin_subcll(x, y, b, &b); *pborrow = b & 1; |