https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89950
Bug ID: 89950
Summary: attribute aligned ignored with attribute vector_size
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
When attribute aligned appears in conjunction with attribute vector_size on the
same declaration and when the former specifies a different alignment than the
latter attribute implies, the alignment specified by the former attribute is
ignored.
However, when attribute aligned is specified on a vector (re)declaration
without attribute vector_size, the alignment is honored.
$ cat z.c && gcc -O2 -S -Wall z.c
void f (void)
{
typedef __attribute__ ((vector_size (1024))) int Vec_1k;
typedef __attribute__ ((aligned (256))) Vec_1k V;
_Static_assert (__alignof__ (V) == 256); // passes
_Static_assert (__builtin_has_attribute (V, aligned (256))); // passes
V v;
_Static_assert (__alignof__ (v) == 256); // passes
_Static_assert (__builtin_has_attribute (v, aligned (256))); // passes
}
void g (void)
{
typedef __attribute__ ((aligned (256), vector_size (1024))) int V;
_Static_assert (__alignof__ (V) == 256); // fails
_Static_assert (__builtin_has_attribute (V, aligned (256))); // fails
V v;
_Static_assert (__alignof__ (v) == 256); // fails
_Static_assert (__builtin_has_attribute (v, aligned (256))); // fails
}
z.c: In function ‘g’:
z.c:17:3: error: static assertion failed
17 | _Static_assert (__alignof__ (V) == 256); //
fails
| ^~~~~~~~~~~~~~
z.c:18:3: error: static assertion failed
18 | _Static_assert (__builtin_has_attribute (V, aligned (256))); //
fails
| ^~~~~~~~~~~~~~
z.c:21:3: error: static assertion failed
21 | _Static_assert (__alignof__ (v) == 256); //
fails
| ^~~~~~~~~~~~~~
z.c:22:3: error: static assertion failed
22 | _Static_assert (__builtin_has_attribute (v, aligned (256))); //
fails
| ^~~~~~~~~~~~~~
