m4/ae_cc_atomic_builtins.m4

   1 # SYNOPSIS
   2 #
   3 #   AE_CC_ATOMIC_BUILTINS([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
   4 #
   5 # LICENSE
   6 #
   7 #   Copyright (c) 2023 Michael Jeanson <mjeanson@efficios.com>
   8 #
   9 #   This program is free software; you can redistribute it and/or modify it
  10 #   under the terms of the GNU General Public License as published by the
  11 #   Free Software Foundation; either version 2 of the License, or (at your
  12 #   option) any later version.
  13 #
  14 #   This program is distributed in the hope that it will be useful, but
  15 #   WITHOUT ANY WARRANTY; without even the implied warranty of
  16 #   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
  17 #   Public License for more details.
  18 #
  19 #   You should have received a copy of the GNU General Public License along
  20 #   with this program. If not, see <https://www.gnu.org/licenses/>.
  21 #
  22 #   As a special exception, the respective Autoconf Macro's copyright owner
  23 #   gives unlimited permission to copy, distribute and modify the configure
  24 #   scripts that are the output of Autoconf when processing the Macro. You
  25 #   need not follow the terms of the GNU General Public License when using
  26 #   or distributing such scripts, even though portions of the text of the
  27 #   Macro appear in them. The GNU General Public License (GPL) does govern
  28 #   all other use of the material that constitutes the Autoconf Macro.
  29 #
  30 #   This special exception to the GPL applies to versions of the Autoconf
  31 #   Macro released by the Autoconf Archive. When you make and distribute a
  32 #   modified version of the Autoconf Macro, you may extend this special
  33 #   exception to the GPL to apply to your modified version as well.
  34
  35 #serial 1
  36
  37 AC_DEFUN([AE_CC_ATOMIC_BUILTINS], [
  38 AC_REQUIRE([AC_PROG_CC])
  39 AC_LANG_PUSH([C])
  40
  41 AC_CACHE_CHECK(
  42   [whether $CC supports atomic builtins],
  43   [ae_cv_cc_atomic_builtins],
  44   [
  45     AC_LINK_IFELSE([
  46       AC_LANG_PROGRAM([
  47         int x, y;
  48       ],[
  49         __atomic_store_n(&x, 0, __ATOMIC_RELAXED);
  50         __atomic_load_n(&x, __ATOMIC_RELAXED);
  51         y = __atomic_exchange_n(&x, 1, __ATOMIC_RELAXED);
  52         __atomic_compare_exchange_n(&x, &y, 0, 0, __ATOMIC_RELAXED, __ATOMIC_RELAXED);
  53         __atomic_add_fetch(&x, 1, __ATOMIC_RELAXED);
  54         __atomic_sub_fetch(&x, 1, __ATOMIC_RELAXED);
  55         __atomic_and_fetch(&x, 0x01, __ATOMIC_RELAXED);
  56         __atomic_or_fetch(&x, 0x01, __ATOMIC_RELAXED);
  57         __atomic_thread_fence(__ATOMIC_RELAXED);
  58         __atomic_signal_fence(__ATOMIC_RELAXED);
  59       ])
  60     ],[
  61       ae_cv_cc_atomic_builtins=yes
  62     ],[
  63       ae_cv_cc_atomic_builtins=no
  64     ])
  65   ]
  66 )
  67
  68 # Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
  69 if test "x$ae_cv_cc_atomic_builtins" = "xyes"; then
  70   $1
  71   :
  72 else
  73   $2
  74   :
  75 fi
  76
  77 AC_LANG_POP
  78 ])dnl AE_CC_ATOMIC_BUILTINS