diff options
Diffstat (limited to 'include/qemu/atomic.h')
| -rw-r--r-- | include/qemu/atomic.h | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h index fe5467d..112a299 100644 --- a/include/qemu/atomic.h +++ b/include/qemu/atomic.h @@ -271,7 +271,19 @@ _oldn; \ }) -/* Abstractions to access atomically (i.e. "once") i64/u64 variables */ +/* + * Abstractions to access atomically (i.e. "once") i64/u64 variables. + * + * The i386 abi is odd in that by default members are only aligned to + * 4 bytes, which means that 8-byte types can wind up mis-aligned. + * Clang will then warn about this, and emit a call into libatomic. + * + * Use of these types in structures when they will be used with atomic + * operations can avoid this. + */ +typedef int64_t aligned_int64_t __attribute__((aligned(8))); +typedef uint64_t aligned_uint64_t __attribute__((aligned(8))); + #ifdef CONFIG_ATOMIC64 /* Use __nocheck because sizeof(void *) might be < sizeof(u64) */ #define qatomic_read_i64(P) \ |