Patchwork [wwwdocs] gcc 4.8 changes - mention scalability improvements

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Submitter Steven Bosscher
Date Oct. 13, 2012, 10:47 p.m.
Message ID <CABu31nMtnHMUOwC5RvTU_07k_OW65Q-DV++OUM--FSyX-kXToQ@mail.gmail.com>
Download mbox | patch
Permalink /patch/191315/
State New
Headers show

Comments

Steven Bosscher - Oct. 13, 2012, 10:47 p.m.
Hello,

This patch adds a short notice about some speed-ups in GCC 4.8 for
extremely large functions (coming from the work done on PR54146 by
several people).
OK for the wwwdocs?

Ciao!
Steven
Richard Guenther - Oct. 15, 2012, 8:46 a.m.
On Sun, Oct 14, 2012 at 12:47 AM, Steven Bosscher <stevenb.gcc@gmail.com> wrote:
> Hello,
>
> This patch adds a short notice about some speed-ups in GCC 4.8 for
> extremely large functions (coming from the work done on PR54146 by
> several people).
> OK for the wwwdocs?

Ok.

Thanks,
Richard.

> Ciao!
> Steven
>
>
>
> Index: htdocs/gcc-4.8/changes.html
> ===================================================================
> RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-4.8/changes.html,v
> retrieving revision 1.44
> diff -u -r1.44 changes.html
> --- htdocs/gcc-4.8/changes.html 9 Oct 2012 18:44:55 -0000       1.44
> +++ htdocs/gcc-4.8/changes.html 13 Oct 2012 22:45:59 -0000
> @@ -65,10 +65,17 @@
>        level, and it makes PRE more aggressive.
>      </li>
>      <li>The struct reorg and matrix reorg optimizations (command-line
> -    options <code>-fipa-struct-reorg</code> and
> -    <code>-fipa-matrix-reorg</code>) have been removed.  They did not
> -    work correctly nor with link-time optimization (LTO), hence were only
> -    applicable to programs consisting of a single translation unit.</li>
> +     options <code>-fipa-struct-reorg</code> and
> +     <code>-fipa-matrix-reorg</code>) have been removed.  They did not
> +     work correctly nor with link-time optimization (LTO), hence were only
> +     applicable to programs consisting of a single translation unit.
> +    </li>
> +    <li>Several scalability bottle-necks have been removed from GCC's
> +     optimization passes.  Compilation of extremely large functions,
> +     e.g. due to the use of the <code>flatten</code> attribute in the
> +     "Eigen" C++ linear algebra templates library, is significantly
> +     faster than previous releases of GCC.
> +    </li>
>    </ul>

Patch

Index: htdocs/gcc-4.8/changes.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-4.8/changes.html,v
retrieving revision 1.44
diff -u -r1.44 changes.html
--- htdocs/gcc-4.8/changes.html	9 Oct 2012 18:44:55 -0000	1.44
+++ htdocs/gcc-4.8/changes.html	13 Oct 2012 22:45:59 -0000
@@ -65,10 +65,17 @@ 
       level, and it makes PRE more aggressive.
     </li>
     <li>The struct reorg and matrix reorg optimizations (command-line
-    options <code>-fipa-struct-reorg</code> and
-    <code>-fipa-matrix-reorg</code>) have been removed.  They did not
-    work correctly nor with link-time optimization (LTO), hence were only
-    applicable to programs consisting of a single translation unit.</li>
+     options <code>-fipa-struct-reorg</code> and
+     <code>-fipa-matrix-reorg</code>) have been removed.  They did not
+     work correctly nor with link-time optimization (LTO), hence were only
+     applicable to programs consisting of a single translation unit.
+    </li>
+    <li>Several scalability bottle-necks have been removed from GCC's
+     optimization passes.  Compilation of extremely large functions,
+     e.g. due to the use of the <code>flatten</code> attribute in the
+     "Eigen" C++ linear algebra templates library, is significantly
+     faster than previous releases of GCC.
+    </li>
   </ul>