------- Comment #11 from pinskia at gcc dot gnu dot org 2010-09-01 18:25
-------
(In reply to comment #10)
> typedef my_unaligned_aliasing_uint32 uint32
> __attribute__((aligned(1),may_alias));
>
> inline __attribute__((__always_inline__)) uint32 READ_UINT32(const void *ptr)
> {
> return *(const my_unaligned_aliasing_uint32 *)ptr;
> }
It does not:
READ_UINT32:
j $31
lw $2,0($4)
The aligned attribute is ignored there I think. memcpy produces:
lbu $2,3($4)
lbu $6,0($4)
lbu $5,1($4)
lbu $3,2($4)
addiu $sp,$sp,-16
sb $6,0($sp)
sb $5,1($sp)
sb $3,2($sp)
sb $2,3($sp)
lw $2,0($sp)
j $31
addiu $sp,$sp,16
Which is bad and could be improved by using lwl/lwr. I will file a bug about
that.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45462
