Y is 28 for introduction of the quoted code in
arch/arm/mm/alignment.c, AFAICT, so how about this one, ok now?
Index: changes.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-4.7/changes.html,v
retrieving revision 1.113
diff -p -u -r1.113 changes.html
--- changes.html 5 Jun 2012 11:03:53 -0000 1.113
+++ changes.html 15 Jun 2012 02:04:46 -0000
@@ -43,6 +43,19 @@
</li>
+ <li>On ARM, when compiling for ARMv6 (but not ARMv6-M), ARMv7-A,
+ ARMv7-R, or ARMv7-M, the new option
+ <code>-munaligned-access</code> is active by default, which for
+ some source codes generates code that accesses memory on unaligned
+ adresses. This will require the kernel of those systems to enable
+ such accesses (controlled by CP15 register <code>c1</code>, refer
+ to ARM documentation). Alternatively or for compatibility with
+ kernels where unaligned accesses are not supported, all code has
+ to be compiled with <code>-mno-unaligned-access</code>.
+ Linux/ARM in official releases has automatically and
+ unconditionally supported unaligned accesses as emitted by GCC due
+ to this option being active since Linux version 2.6.28.</li>
+
<li>Support on ARM for the legacy floating-point accelerator (FPA) and
the mixed-endian floating-point format that it used has been obsoleted.
The ports that still use this format have been obsoleted as well.
brgds, H-P
