File size: 1,555 Bytes
3dcad1f |
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 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 |
dnl Check for __builtin_expect.
dnl Copyright 2016-2023 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
dnl Written by Paul Eggert.
AC_DEFUN([gl___BUILTIN_EXPECT],
[
AC_CACHE_CHECK([for __builtin_expect],
[gl_cv___builtin_expect],
[AC_LINK_IFELSE(
[AC_LANG_SOURCE([[
int
main (int argc, char **argv)
{
argc = __builtin_expect (argc, 100);
return argv[argc != 100][0];
}]])],
[gl_cv___builtin_expect=yes],
[AC_LINK_IFELSE(
[AC_LANG_SOURCE([[
#include <builtins.h>
int
main (int argc, char **argv)
{
argc = __builtin_expect (argc, 100);
return argv[argc != 100][0];
}]])],
[gl_cv___builtin_expect="in <builtins.h>"],
[gl_cv___builtin_expect=no])])])
if test "$gl_cv___builtin_expect" = yes; then
AC_DEFINE([HAVE___BUILTIN_EXPECT], [1])
elif test "$gl_cv___builtin_expect" = "in <builtins.h>"; then
AC_DEFINE([HAVE___BUILTIN_EXPECT], [2])
fi
AH_VERBATIM([HAVE___BUILTIN_EXPECT],
[/* Define to 1 if the compiler supports __builtin_expect,
and to 2 if <builtins.h> does. */
#undef HAVE___BUILTIN_EXPECT
#ifndef HAVE___BUILTIN_EXPECT
# define __builtin_expect(e, c) (e)
#elif HAVE___BUILTIN_EXPECT == 2
# include <builtins.h>
#endif
])
])
|