[Bug middle-end/89544] Argument marshalling incorrectly assumes stack slots are naturally aligned.

[hjl.tools at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89544

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2025-06-27
                 CC|                            |hjl.tools at gmail dot com
             Status|UNCONFIRMED                 |NEW

--- Comment #10 from H.J. Lu <hjl.tools at gmail dot com> ---
On x86, arguments on stack also have natural alignment:

[hjl@gnu-tgl-3 pr120839]$ cat x.c
typedef struct {
  long double a;
  long double b;
} c __attribute__((aligned(32)));
extern double d;
void
e (c f)
{
  _Static_assert (__alignof (f) == 16, "__alignof (f) == 16)");
  d = f.a;
}
[hjl@gnu-tgl-3 pr120839]$ make CC=gcc  
gcc -O2 -S x.c
x.c: In function ‘e’:
x.c:9:3: error: static assertion failed: "__alignof (f) == 16)"
    9 |   _Static_assert (__alignof (f) == 16, "__alignof (f) == 16)");
      |   ^~~~~~~~~~~~~~
make: *** [Makefile:36: x.s] Error 1
[hjl@gnu-tgl-3 pr120839]$