meson: fix CONFIG_ATOMIC128 check

The current testing code isn't correct and matching QEMU usage:

testfile.c: In function 'main':
testfile.c:5:11: error: incorrect number of arguments to function '__atomic_load'
    5 |       y = __atomic_load(&x, 0);
      |           ^~~~~~~~~~~~~
testfile.c:6:7: error: argument 2 of '__atomic_store' must be a pointer type
    6 |       __atomic_store(&x, y, 0);
      |       ^~~~~~~~~~~~~~
testfile.c:7:7: error: argument 3 of '__atomic_compare_exchange' must be a pointer type
    7 |       __atomic_compare_exchange(&x, &y, x, 0, 0, 0);
      |       ^~~~~~~~~~~~~~~~~~~~~~~~~

Replace the test with common atomics test for u64 and u128 that matches
better QEMU needs.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
This commit is contained in:
Marc-André Lureau 2022-02-28 16:03:09 +04:00
parent 848126d11e
commit d2958fb0b6

View file

@ -1853,21 +1853,23 @@ config_host_data.set('HAVE_BROKEN_SIZE_MAX', not cc.compiles('''
return printf("%zu", SIZE_MAX);
}''', args: ['-Werror']))
# See if 64-bit atomic operations are supported.
# Note that without __atomic builtins, we can only
# assume atomic loads/stores max at pointer size.
config_host_data.set('CONFIG_ATOMIC64', cc.links('''
atomic_test = '''
#include <stdint.h>
int main(void)
{
uint64_t x = 0, y = 0;
@0@ x = 0, y = 0;
y = __atomic_load_n(&x, __ATOMIC_RELAXED);
__atomic_store_n(&x, y, __ATOMIC_RELAXED);
__atomic_compare_exchange_n(&x, &y, x, 0, __ATOMIC_RELAXED, __ATOMIC_RELAXED);
__atomic_exchange_n(&x, y, __ATOMIC_RELAXED);
__atomic_fetch_add(&x, y, __ATOMIC_RELAXED);
return 0;
}'''))
}'''
# See if 64-bit atomic operations are supported.
# Note that without __atomic builtins, we can only
# assume atomic loads/stores max at pointer size.
config_host_data.set('CONFIG_ATOMIC64', cc.links(atomic_test.format('uint64_t')))
has_int128 = cc.links('''
__int128_t a;
@ -1882,15 +1884,10 @@ has_int128 = cc.links('''
config_host_data.set('CONFIG_INT128', has_int128)
if has_int128
has_atomic128 = cc.links('''
int main(void)
{
unsigned __int128 x = 0, y = 0;
y = __atomic_load(&x, 0);
__atomic_store(&x, y, 0);
__atomic_compare_exchange(&x, &y, x, 0, 0, 0);
return 0;
}''')
# "do we have 128-bit atomics which are handled inline and specifically not
# via libatomic". The reason we can't use libatomic is documented in the
# comment starting "GCC is a house divided" in include/qemu/atomic128.h.
has_atomic128 = cc.links(atomic_test.format('unsigned __int128'))
config_host_data.set('CONFIG_ATOMIC128', has_atomic128)