On 10/08/12 14:44, Ulrich Weigand wrote: > Ramana Radhakrishnan wrote: > >> In addition I'd like this documented in changes.html for each of the >> release branches. > > Richard Earnshaw wrote: > >> However, it does need to be release-noted. > > Would the following htdocs patch be OK with you? Feel free to suggest > a more appropriate wording ... >
I think we need to make it clear that this also fixes a bug in the compiler that could lead to a run-time error. Otherwise, people will be asking why an abi-breaking change was made mid-cycle. R. > Bye, > Ulrich > > Index: gcc-4.6/changes.html > =================================================================== > RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-4.6/changes.html,v > retrieving revision 1.141 > diff -u -p -r1.141 changes.html > --- gcc-4.6/changes.html 12 Jun 2012 10:43:41 -0000 1.141 > +++ gcc-4.6/changes.html 10 Aug 2012 13:40:57 -0000 > @@ -68,6 +68,12 @@ > default by <code>-Wall</code> flag and > <code>-Wunused-but-set-parameter</code> > by <code>-Wall -Wextra</code> flags.</li> > > + <li>In GCC version 4.6.4 the default alignment of vector types on ARM > EABI > + targets has been changed to 8 bytes (for types larger than 8 bytes in > size), > + to comply with the AAPCS. This is an ABI change that affects e.g. > layout of > + structures having a member of vector type. Code using such types may be > + incompatible with binary objects built with older versions of GCC.</li> > + > <li><p>Support for a number of older systems and recently > unmaintained or untested target ports of GCC has been declared > obsolete in GCC 4.6. Unless there is activity to revive them, the > Index: gcc-4.7/changes.html > =================================================================== > RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-4.7/changes.html,v > retrieving revision 1.123 > diff -u -p -r1.123 changes.html > --- gcc-4.7/changes.html 23 Jul 2012 05:58:05 -0000 1.123 > +++ gcc-4.7/changes.html 10 Aug 2012 13:40:57 -0000 > @@ -121,6 +121,12 @@ > different GCC versions and with C++98/C++03 code compiled with any > version. > </li> > > + <li>In GCC version 4.7.2 the default alignment of vector types on ARM > EABI > + targets has been changed to 8 bytes (for types larger than 8 bytes in > size), > + to comply with the AAPCS. This is an ABI change that affects e.g. > layout of > + structures having a member of vector type. Code using such types may be > + incompatible with binary objects built with older versions of GCC.</li> > + > <li>More information on porting to GCC 4.7 from previous versions > of GCC can be found in > the <a href="http://gcc.gnu.org/gcc-4.7/porting_to.html";>porting > Index: gcc-4.8/changes.html > =================================================================== > RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-4.8/changes.html,v > retrieving revision 1.9 > diff -u -p -r1.9 changes.html > --- gcc-4.8/changes.html 31 Jul 2012 12:13:01 -0000 1.9 > +++ gcc-4.8/changes.html 10 Aug 2012 13:40:57 -0000 > @@ -24,6 +24,12 @@ more information about requirements to b > <p>The G++ namespace association extension, <code>__attribute > ((strong))</code>, > has been deprecated. Inline namespaces should be used instead.</p> > > +<p>The default alignment of vector types on ARM EABI targets has been changed > +to 8 bytes (for types larger than 8 bytes in size), to comply with the AAPCS. > +This is an ABI change that affects e.g. layout of structures having a member > +of vector type. Code using such types may be incompatible with binary > objects > +built with older versions of GCC.</p> > + > <h2>General Optimizer Improvements</h2> > > <ul> > >
