[Bug target/53016] memcpy optimization can cause unaligned access on ARM

[rearnsha at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53016

Richard Earnshaw <rearnsha at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID

--- Comment #8 from Richard Earnshaw <rearnsha at gcc dot gnu.org> 2012-04-18 
14:23:04 UTC ---
Casts do not change the fact that the pointer initialized in statement I
highlighted creates undefined behaviour.  The fact that you are using memcpy is
a red herring.

>From c99:

6.3.2.3 Pointers

7) A pointer to an object or incomplete type may be converted to a pointer to a
different object or incomplete type. If the resulting pointer is not correctly
aligned for the pointed-to type, the behavior is undefined. ...