qemu/host/include/generic/host
Thomas Huth 34aee9c946 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>
2023-11-13 11:35:47 +01:00
..
crypto crypto: Add generic 64-bit carry-less multiply routine 2023-09-15 13:57:00 +00:00
atomic128-cas.h host/include/generic/host/atomic128: Fix compilation problem with Clang 17 2023-11-13 11:35:47 +01:00
atomic128-ldst.h host/include/generic/host/atomic128: Fix compilation problem with Clang 17 2023-11-13 11:35:47 +01:00
cpuinfo.h other architectures: spelling fixes 2023-07-25 17:14:07 +03:00
load-extract-al16-al8.h accel/tcg: Extract load_atom_extract_al16_or_al8 to host header 2023-05-30 09:51:11 -07:00
store-insert-al16.h accel/tcg: Extract store_atom_insert_al16 to host header 2023-05-30 09:51:11 -07:00