diff options
| author | Thomas Huth <thuth@redhat.com> | 2023-11-08 09:59:54 +0100 |
|---|---|---|
| committer | Thomas Huth <thuth@redhat.com> | 2023-11-13 11:35:47 +0100 |
| commit | 34aee9c94691f529cd952f9483a6b357ca098042 (patch) | |
| tree | 54692e4c2baa30060f4d9789783fe531541e57cc /include | |
| parent | 69680740eafa1838527c90155a7432d51b8ff203 (diff) | |
host/include/generic/host/atomic128: Fix compilation problem with Clang 17
When compiling QEMU with Clang 17 on a s390x, the compilation fails:
In file included from ../accel/tcg/cputlb.c:32:
In file included from /root/qemu/include/exec/helper-proto-common.h:10:
In file included from /root/qemu/include/qemu/atomic128.h:62:
/root/qemu/host/include/generic/host/atomic128-ldst.h:68:15: error:
__sync builtin operation MUST have natural alignment (consider using __
atomic). [-Werror,-Wsync-alignment]
68 | } while (!__sync_bool_compare_and_swap_16(ptr_align, old, new.i));
| ^
In file included from ../accel/tcg/cputlb.c:32:
In file included from /root/qemu/include/exec/helper-proto-common.h:10:
In file included from /root/qemu/include/qemu/atomic128.h:61:
/root/qemu/host/include/generic/host/atomic128-cas.h:36:11: error:
__sync builtin operation MUST have natural alignment (consider using __a
tomic). [-Werror,-Wsync-alignment]
36 | r.i = __sync_val_compare_and_swap_16(ptr_align, c.i, n.i);
| ^
2 errors generated.
It's arguably a bug in Clang since we already use __builtin_assume_aligned()
to tell the compiler that the pointer is properly aligned. But according to
https://github.com/llvm/llvm-project/issues/69146 it seems like the Clang
folks don't see an easy fix on their side and recommend to use a type
declared with __attribute__((aligned(16))) to work around this problem.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1934
Message-ID: <20231108085954.313071-1-thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/qemu/int128.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/qemu/int128.h b/include/qemu/int128.h index 73624e8be7..174bd7dafb 100644 --- a/include/qemu/int128.h +++ b/include/qemu/int128.h @@ -10,6 +10,7 @@ */ #if defined(CONFIG_INT128) && !defined(CONFIG_TCG_INTERPRETER) typedef __int128_t Int128; +typedef __int128_t __attribute__((aligned(16))) Int128Aligned; static inline Int128 int128_make64(uint64_t a) { @@ -224,6 +225,7 @@ static inline Int128 int128_rems(Int128 a, Int128 b) #else /* !CONFIG_INT128 */ typedef struct Int128 Int128; +typedef struct Int128 __attribute__((aligned(16))) Int128Aligned; /* * We guarantee that the in-memory byte representation of an |