[PATCH i386 5/8] [AVX-512] Extend vectorizer hooks.

Uros Bizjak ubizjak@gmail.com
Fri Jan 3 11:25:00 GMT 2014


On Fri, Jan 3, 2014 at 12:20 PM, Eric Botcazou <ebotcazou@adacore.com> wrote:
>> When compiled with -m32 -mavx, we get:
>>
>>         .align 32
>>         .type   a, @object
>>         .size   a, 32
>> a:
>>
>> so, the alignment was already raised elsewhere. We get .align 16 for
>> -msse -m32 when vectorizing.
>>
>> without -msse (and consequently without vectorizing), we get for -m32:
>>
>>         .align 4
>>         .type   a, @object
>>         .size   a, 32
>> a:
>>
>> which corresponds to 32bit ABI rules (we still get .align16 for 64bit ABI).
>
> Yes, but the issue is that it was 32 before so the alignment decrease is weird.

Yes, but this change is benign, and as shown, I don't think we need
this functionality at all. The data from other TUs is accessed with a
4 byte alignment (on 32bit targets, and unfortunately also on 64bit
targets), and the alignment of local data is increased elsewhere.

I am testing a patch that removes "max_align" part from ix86_data_alignment.

Uros.



More information about the Gcc-patches mailing list