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[WEB] Describe -pg and LTO changes

Message ID 20141116200245.GA10567@basil.fritz.box
State New
Headers show

Commit Message

Andi Kleen Nov. 16, 2014, 8:02 p.m. UTC
This patch describes some user visible changes that were 
added to gcc 5.

Ok to commit? 

-Andi

Comments

Jeff Law Nov. 17, 2014, 7:44 p.m. UTC | #1
On 11/16/14 13:02, Andi Kleen wrote:
>
> This patch describes some user visible changes that were
> added to gcc 5.
>
> Ok to commit?
Yes, this is fine.  Thanks,
Jeff
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Patch

Index: htdocs/gcc-5/changes.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-5/changes.html,v
retrieving revision 1.25
diff -u -r1.25 changes.html
--- htdocs/gcc-5/changes.html	14 Nov 2014 21:32:32 -0000	1.25
+++ htdocs/gcc-5/changes.html	16 Nov 2014 20:03:07 -0000
@@ -154,6 +154,11 @@ 
 	about qualifiers on pointers being discarded via a new warning option
 	<code>-Wno-discarded-qualifiers</code>.</li>
     <li>The C front end now generates more precise caret diagnostics.</li>
+    <li>The -pg option now only affects the current file in a LTO build.</li>
+    <li>A new no_reorder attribute has been added, that prevents reordering
+	of a specific symbol against other such symbols or inline assembler.
+	This is a more focussed alternative to 
+	<code>-fno-toplevel-reorder</code>.
   </ul>
 
 <h3 id="cxx">C++</h3>
@@ -295,6 +300,17 @@ 
 
    </ul>
 
+<h3 id="x86">IA-32/x86-64</h3>
+  <ul>
+	<li>The new <code>-mrecord-mcount</code> option for <code>-pg</code>
+	generates a Linux kernel style table of pointers to mcount or
+	__fentry__ calls at the beginning of functions. The new
+	<code>-mnop-mcount</code> option in addition also generates nops in
+	place of the __fentry__ or mcount call, so that a call per function
+	can be later patched in. This can be used for low overhead tracing or
+	hot code patching.</li>
+  </ul>
+
 <h2 id="os">Operating Systems</h2>
 
   <h3 id="dragonfly">DragonFly BSD</h3>
@@ -304,7 +320,11 @@ 
   </ul>
 
 <!-- h2>Documentation improvements</h2-->
-<!-- h2>Other significant improvements</h2 -->
-
+<h2>Other significant improvements</h2>
+  <h3 id="gcc-ar"></h3>
+  <ul>
+    <li>The <code>gcc-ar, gcc-nm, gcc-ranlib</code> wrappers now
+	understand a <code>-B</code> option to set the compiler to use.</li>
+  </ul>
 </body>
 </html>