On Monday 2009-11-02 07:22, David Miller wrote:
>> +static inline uint32_t deref_get_32(const void *ptr)
>> +{
>> + uint32_t ret;
>> + memcpy(&ret, ptr, sizeof(ret));
>> + return ret;
>> +}
>>
>> Is what I use in one project; however, trying to minimize the
>> unalignedness - iptables is a "perfect" example, and netlink
>> may do the same tho I am not sure - seems to be the best
>> approach in serialized streams.
>
>This will not work all the time.
>
>If GCC can see at the inlining point that 'ptr' is of a type that
>should be properly aligned it can inline the memcpy and still emit
>the very unaligned load or store that you're trying to avoid.
Hi Dave,
Indeed it seems to be this way. Hm, bad.
What codes are you using on your alignment-sensitive SPARCs -
the standard bitshifting, "char *p; p[0]<<24 | p[1]<<16 | p[2]<<8 | p[3]"?
--
To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
