1 /* Check stack alignment.  Generic version.
2    Copyright (C) 2003-2022 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9 
10    The GNU C Library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14 
15    You should have received a copy of the GNU Lesser General Public
16    License along with the GNU C Library; if not, see
17    <https://www.gnu.org/licenses/>.  */
18 
19 #include <stdio.h>
20 #include <stdint.h>
21 
22 int
23 __attribute__ ((weak, noclone, noinline))
is_aligned(void * p,int align)24 is_aligned (void *p, int align)
25 {
26   return (((uintptr_t) p) & (align - 1)) != 0;
27 }
28 
29 #ifndef TEST_STACK_ALIGN_INIT
30 # define TEST_STACK_ALIGN_INIT() 0
31 #endif
32 
33 #define TEST_STACK_ALIGN() \
34   ({								     \
35     double _d = 12.0;						     \
36     long double _ld = 15.0;					     \
37     int _ret = TEST_STACK_ALIGN_INIT ();			     \
38 								     \
39     printf ("double:  %g %p %zu\n", _d, &_d, __alignof (double));    \
40     _ret += is_aligned (&_d, __alignof (double));		     \
41 								     \
42     printf ("ldouble: %Lg %p %zu\n", _ld, &_ld,			     \
43 	    __alignof (long double));				     \
44     _ret += is_aligned (&_ld, __alignof (long double));		     \
45     _ret;							     \
46    })
47