1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
|
dnl Checks for availability of GCC's atomic operations builtins.
dnl Defines HAVE_GCC_ATOMIC_BUILTINS if available.
AC_DEFUN([WX_ATOMIC_BUILTINS],
[
AC_REQUIRE([AC_PROG_CC])
if test -n "$GCC"; then
AC_MSG_CHECKING([for __sync_fetch_and_add and __sync_sub_and_fetch builtins])
AC_CACHE_VAL(wx_cv_cc_gcc_atomic_builtins, [
AC_TRY_LINK(
[],
[
unsigned int value=0;
/* wxAtomicInc doesn't use return value here */
__sync_fetch_and_add(&value, 2);
__sync_sub_and_fetch(&value, 1);
/* but wxAtomicDec does, so mimic that: */
volatile unsigned int r2 = __sync_sub_and_fetch(&value, 1);
],
wx_cv_cc_gcc_atomic_builtins=yes,
wx_cv_cc_gcc_atomic_builtins=no)
])
AC_MSG_RESULT([$wx_cv_cc_gcc_atomic_builtins])
if test $wx_cv_cc_gcc_atomic_builtins = yes; then
AC_DEFINE([HAVE_GCC_ATOMIC_BUILTINS])
fi
fi
])
|
