From patchwork Tue Jun 22 11:35:46 2010
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Subject: [wwwdocs] Some news into gcc-4.6
Date: Tue, 22 Jun 2010 01:35:46 -0000
From: Jan Hubicka <hubicka@ucw.cz>
X-Patchwork-Id: 56462
Message-Id: <20100622113546.GA18560@kam.mff.cuni.cz>
To: gcc-patches@gcc.gnu.rg

Hi,
before we forget about this, this patch announces the new -fsuggest-attribute
feature and changes in IPA.
For marketing reasons I think we might add compile time and memory usage improvements
and mention df changes (and hopefully others).  The buildtime improved from over 11m
to 9m42s, so I am quite safe with that 10% claim.

Honza


Index: changes.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-4.6/changes.html,v
retrieving revision 1.18
diff -u -r1.18 changes.html
--- changes.html	13 Jun 2010 12:44:28 -0000	1.18
+++ changes.html	22 Jun 2010 11:33:43 -0000
@@ -43,6 +43,34 @@
       with options that can affect standards compliance but result in
       better optimized code.  For example <code>-Ofast</code> enables
       <code>-ffast-math</code>.</li>
+      <li>Interprocedural optimizations improvements</li>
+      <ul>
+	  <li>Interprocedural framework was re-tuned for link time
+	      optimization.</li>
+	  <li>Improved auto-detection of <code>const</code> and <code>pure</code>
+	      functions.  Newly <code>noreturn</code> functions are auto-detected.
+	      <p><code>-fsuggest-attribute</code> flag is available to make compiler
+	      to inform users when adding attributes into headers might improve
+	      code generation.</p></li>
+	  <li>Inlining heuristics was improved:
+	      <ul>
+		 <li>Number of problems with large compilation units was fixed.</li>
+		 <li>Inlining of callbacks is now more aggressive.</li>
+		 <li>Virtual methods are inlined caller is inlined
+		     and devirtualization is possible then.</li>
+	      </ul>
+	  <li>
+	</ul>
+  </ul>
+
+<h2>Compile time and memory usage improvements</h2>
+  <ul>
+      <li>Datastructures used by dataflow framework in GCC was reorganized
+	  for better memory usage and more cache locality.  Compile
+	  time is improved especially on units with large functions (possibly
+	  resulting from a lot of inlining) not fitting in processor cache.
+	  Compile time of GCC C compiler binary with link time optimization
+	  was improved by over 10% (benchmared on x86-64 target).</li>
   </ul>
 
 <h2>New Languages and Language specific improvements</h2>