sysdeps/x86_64/tst-stack-align.h

   1 /* Copyright (C) 2003-2018 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <stdio.h>
  19 #include <stdint.h>
  20
  21 #define TEST_STACK_ALIGN() \
  22   ({                                                                         \
  23     /* AMD64 ABI mandates 16byte aligned stack.                              \
  24        Unfortunately, current GCC doesn't support __int128 or __float128     \
  25        types, so use aligned attribute instead.  */                          \
  26     struct _S                                                                \
  27       {                                                                      \
  28         int _i __attribute__((aligned (16)));                                \
  29         int _pad[3];                                                         \
  30       } _s = { ._i = 18 };                                                   \
  31     double _d = 12.0;                                                        \
  32     long double _ld = 15.0;                                                  \
  33     int _ret = 0;                                                            \
  34     printf ("__int128:  %d %p %zu\n", _s._i, &_s, __alignof (_s));           \
  35     if ((((uintptr_t) &_s) & (__alignof (_s) - 1)) != 0)                     \
  36       _ret = 1;                                                              \
  37                                                                              \
  38     printf ("double:  %g %p %zu\n", _d, &_d, __alignof (double));            \
  39     if ((((uintptr_t) &_d) & (__alignof (double) - 1)) != 0)                 \
  40       _ret = 1;                                                              \
  41                                                                              \
  42     printf ("ldouble: %Lg %p %zu\n", _ld, &_ld, __alignof (long double));    \
  43     if ((((uintptr_t) &_ld) & (__alignof (long double) - 1)) != 0)           \
  44       _ret = 1;                                                              \
  45     _ret;                                                                    \
  46     })