Re: [GCC 4.8 changes] PATCH: Mention several user-visible changes for x86

[Uros Bizjak <ubizjak at gmail dot com>]

On Tue, Feb 12, 2013 at 8:45 PM, Igor Zamyatin <izamyatin@gmail.com> wrote:

> This patch updates GCC 4.8 changes.html to mention Broadwell's
> features, RTM and HLE support and fixed pre-reload scheduler.
>
> OK to commit?
>
>
> Thanks,
> Igor
>
> Index: htdocs/gcc-4.8/changes.html
> ===================================================================
> RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-4.8/changes.html,v
> retrieving revision 1.95
> diff -c -r1.95 changes.html
> *** htdocs/gcc-4.8/changes.html 11 Feb 2013 15:12:58 -0000      1.95
> --- htdocs/gcc-4.8/changes.html 12 Feb 2013 15:10:41 -0000
> ***************
> *** 460,465 ****
> --- 460,471 ----
>       wrong results.  You must build all
>       modules with <code>-mpreferred-stack-boundary=3</code>, including any
>       libraries.  This includes the system libraries and startup modules.</li>
> +     <li>Support for the new Intel processor codename Broadwell with RDSEED,
> +     ADCX, ADOX, PREFETCHW is available through <code>-madx</code>,
> +     <code>-mprfchw</code>, <code>-mrdseed</code>.
> +     </li>
> +     <li> Support for Intel RTM and HLE intrinsics, built-in
> functions and code generation is available via -mrtm and -mhle.
> +     </li>

Please also mention new -mfxsr, -mxsave and -mxsaveopt options.

>       <li> New built-in functions to detect run-time CPU type and ISA:
>       <ul>
>         <li>A built-in function <code>__builtin_cpu_is</code> has been added to
> ***************
> *** 524,529 ****
> --- 530,538 ----
>       <a href="http://gcc.gnu.org/wiki/FunctionMultiVersioning";>wiki</a>
> for more
>       information.
>       </li>
> +     <li> Problem with instability of pre-reload scheduler on x86
> targets was fixed. Now option -fschedule-insn
> +     can be used loosely to reach better performance.

"used loosely" in what sense?

Thanks,
Uros.