[LTP] [PATCH 2/4] m4: add a check for __sync_add_and_fetch

[Cyril Hrubis <chrubis@suse.cz>]

Hi!
> +#if HAVE_SYNC_ADD_AND_FETCH == 1
> +static inline __attribute__((always_inline)) int atomic_add_return(int i, int *v)
> +{
> +	return __sync_add_and_fetch(v, i);
> +}
> +#else
> +#error Your compiler does not provide __sync_add_and_fetch and LTP\
> + implementation is missing for your architecture.
> +#endif
> +
>  static inline unsigned int tst_atomic_inc(int *v)
>  {
> -	return __sync_add_and_fetch(v, 1);
> +	return atomic_add_return(1, v);
>  }

I guess that we can make it a bit easier by defining the
tst_atomic_inc() directly, i.e.

#if HAVE_SYNC_ADD_AND_FETCH
static inline int tst_atomic_inc(int *v)
{
	return __sync_add_and_fetch(v, 1);
}
#else
...


>  #endif	/* TST_ATOMIC_H__ */
> diff --git a/m4/ltp-sync_add_and_fetch.m4 b/m4/ltp-sync_add_and_fetch.m4
> new file mode 100644
> index 000000000000..b9e222589267
> --- /dev/null
> +++ b/m4/ltp-sync_add_and_fetch.m4
> @@ -0,0 +1,29 @@
> +dnl
> +dnl Copyright (c) Linux Test Project, 2016
> +dnl
> +dnl This program is free software;  you can redistribute it and/or modify
> +dnl it under the terms of the GNU General Public License as published by
> +dnl the Free Software Foundation; either version 2 of the License, or
> +dnl (at your option) any later version.
> +dnl
> +dnl This program is distributed in the hope that it will be useful,
> +dnl but WITHOUT ANY WARRANTY;  without even the implied warranty of
> +dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
> +dnl the GNU General Public License for more details.
> +dnl
> +
> +AC_DEFUN([LTP_CHECK_SYNC_ADD_AND_FETCH],[dnl
> +	AC_MSG_CHECKING([for __sync_add_and_fetch])
> +	AC_LINK_IFELSE([AC_LANG_SOURCE([
> +int main(void) {
> +	int i = 0;
> +	return __sync_add_and_fetch(&i, 1);
> +}])],[has_saac="yes"])
> +
> +if test "x$has_saac" = xyes; then
> +	AC_DEFINE(HAVE_SYNC_ADD_AND_FETCH,1,[Define to 1 if you have __sync_add_and_fetch])
> +	AC_MSG_RESULT(yes)
> +else
> +	AC_MSG_RESULT(no)
> +fi
> +])
> -- 
> 1.8.3.1
> 
> 
> -- 
> Mailing list info: https://lists.linux.it/listinfo/ltp

-- 
Cyril Hrubis
chrubis@suse.cz