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Re: [PATCH] update gcc-3.4/changes web page with Xtensa ABI changes


Gerald Pfeifer wrote:
On Fri, 5 Mar 2004, Bob Wilson wrote:

Here is a patch to the gcc-3.4/changes web page to describe my recent
ABI changes for the Xtensa port.  I ran it through the HTML validator
and it looks OK.


I suggest to move the note on ABI breakage to the very top of the new
entry.

Good idea. I've committed the change as shown in the attached patch.


--Bob
Index: changes.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-3.4/changes.html,v
retrieving revision 1.102
diff -u -r1.102 changes.html
--- changes.html	25 Feb 2004 10:08:49 -0000	1.102
+++ changes.html	8 Mar 2004 03:11:06 -0000
@@ -786,6 +786,25 @@
 
 <h3>Xtensa</h3>
   <ul>
+    <li>Several ABI bugs have been fixed.  Unfortunately, these changes
+    break binary compatibility with earlier releases.
+    <ul>
+      <li>For big-endian processors, the padding of aggregate return values
+      larger than a word has changed.  If the size of an aggregate return
+      value is not a multiple of 32 bits, previous versions of GCC inserted
+      padding in the most-significant bytes of the first return value
+      register.  Aggregates larger than a word are now padded in the
+      least-significant bytes of the last return value register used.
+      Aggregates smaller than a word are still padded in the most-significant
+      bytes.  The return value padding has not changed for little-endian
+      processors.</li>
+      <li>Function arguments with 16-byte alignment are now properly
+      aligned.</li>
+      <li>The implementation of the <code>va_list</code> type has changed.
+      A <code>va_list</code> value created by <code>va_start</code> from a
+      previous release cannot be used with <code>va_arg</code> from this
+      release, or vice versa.</li>
+    </ul></li>
     <li>More processor configuration options for Xtensa processors are
     supported:
     <ul>

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