2016-12-16 Paul Eggert <eggert@cs.ucla.edu>
+ builtin-expect: improve port to IBM XL C
+ Problem reported for z/OS by Daniel Richard G. in:
+ http://lists.gnu.org/archive/html/bug-gnulib/2016-12/msg00079.html
+ * m4/builtin-expect.m4 (gl___BUILTIN_EXPECT):
+ Test for <builtins.h> directly.
+
builtin-expect: port to IBM XL C
Problem reported for z/OS by Daniel Richard G. in:
http://lists.gnu.org/archive/html/bug-gnulib/2016-12/msg00074.html
AC_CACHE_CHECK([for __builtin_expect],
[gl_cv___builtin_expect],
[AC_LINK_IFELSE(
- [AC_LANG_SOURCE([AC_INCLUDES_DEFAULT[
+ [AC_LANG_SOURCE([[
int
main (int argc, char **argv)
{
return argv[argc != 100][0];
}]])],
[gl_cv___builtin_expect=yes],
- [gl_cv___builtin_expect=no])])
+ [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 or standard include files support
- __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
])
])