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dnl AC_C_RESTRICT
dnl Do nothing if the compiler accepts the restrict keyword.
dnl Otherwise define restrict to __restrict__ or __restrict if one of
dnl those work, otherwise define restrict to be empty.
AC_DEFUN([AC_C_RESTRICT],
[AC_MSG_CHECKING([for restrict])
ac_cv_c_restrict=no
for ac_kw in restrict __restrict__ __restrict; do
AC_TRY_COMPILE([],[char * $ac_kw p;],[ac_cv_c_restrict=$ac_kw; break])
done
AC_MSG_RESULT([$ac_cv_c_restrict])
case $ac_cv_c_restrict in
restrict) ;;
no) AC_DEFINE([restrict],,
[Define as `__restrict' if that's what the C compiler calls
it, or to nothing if it is not supported.]) ;;
*) AC_DEFINE_UNQUOTED([restrict],$ac_cv_c_restrict) ;;
esac])
dnl AC_C_BUILTIN_EXPECT
dnl Check whether compiler understands __builtin_expect.
AC_DEFUN([AC_C_BUILTIN_EXPECT],
[AC_CACHE_CHECK([for __builtin_expect],[ac_cv_builtin_expect],
[cat > conftest.c <<EOF
#line __oline__ "configure"
int foo (int a)
{
a = __builtin_expect (a, 10);
return a == 10 ? 0 : 1;
}
EOF
if AC_TRY_COMMAND([${CC-cc} $CFLAGS -nostdlib -nostartfiles
-o conftest conftest.c -lgcc >&AC_FD_CC]); then
ac_cv_builtin_expect=yes
else
ac_cv_builtin_expect=no
fi
rm -f conftest*])
if test x"$ac_cv_builtin_expect" = x"yes"; then
AC_DEFINE(HAVE_BUILTIN_EXPECT,,
[Define if you have the `__builtin_expect' function.])
fi])
dnl AC_C_ALWAYS_INLINE
dnl Define inline to something appropriate, including the new always_inline
dnl attribute from gcc 3.1
AC_DEFUN([AC_C_ALWAYS_INLINE],
[AC_C_INLINE
if test x"$GCC" = x"yes" -a x"$ac_cv_c_inline" = x"inline"; then
AC_MSG_CHECKING([for always_inline])
SAVE_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -Wall -Werror"
AC_TRY_COMPILE([],
[__attribute__ ((__always_inline__)) void f (void);
#ifdef __cplusplus
42 = 42; // obviously illegal - we want c++ to fail here
#endif],
[ac_cv_always_inline=yes],[ac_cv_always_inline=no])
CFLAGS="$SAVE_CFLAGS"
AC_MSG_RESULT([$ac_cv_always_inline])
if test x"$ac_cv_always_inline" = x"yes"; then
AC_DEFINE_UNQUOTED([inline],[__attribute__ ((__always_inline__))])
fi
fi])
dnl AC_C_ATTRIBUTE_ALIGNED
dnl define ATTRIBUTE_ALIGNED_MAX to the maximum alignment if this is supported
AC_DEFUN([AC_C_ATTRIBUTE_ALIGNED],
[SAV_CFLAGS=$CFLAGS;
if test x"$GCC" = xyes; then CFLAGS="$CFLAGS -Werror"; fi
AC_CACHE_CHECK([__attribute__ ((aligned ())) support],
[ac_cv_c_attribute_aligned],
[ac_cv_c_attribute_aligned=0
for ac_cv_c_attr_align_try in 2 4 8 16 32 64; do
AC_TRY_COMPILE([],
[static struct s {
char a;
char b __attribute__ ((aligned($ac_cv_c_attr_align_try)));
} S = {0, 0};
switch (1) {
case 0:
case (long)(&((struct s *)0)->b) == $ac_cv_c_attr_align_try:
return 0;
}
return (long)&S;],
[ac_cv_c_attribute_aligned=$ac_cv_c_attr_align_try])
done])
if test x"$ac_cv_c_attribute_aligned" != x"0"; then
AC_DEFINE_UNQUOTED([ATTRIBUTE_ALIGNED_MAX],
[$ac_cv_c_attribute_aligned],[maximum supported data alignment])
fi
CFLAGS=$SAV_CFLAGS])
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