On Fri, Jan 8, 2016 at 1:38 PM, Jakub Jelinek <ja...@redhat.com> wrote:
> On Fri, Jan 08, 2016 at 01:27:08PM -0800, H.J. Lu wrote:
>> > That is just wrong and will severely pessimize correct code.
>> > Please don't waste time on that.
>> >
>>
>> Do you have an example to show it will pessimize correct code?
>
> Anything where the compiler can't figure out alignment info and you use the
> aligned functions, starting from trivial tests like:
>
> void foo (float *p, __m256 q)
> {
> _mm256_store_ps (p, q);
> }
>
> etc. The SSE*/AVX* docs say clearly that if the pointer argument is not
> properly aligned, a #GP is generated, and you need to use the
> *storeu*/*loadu* intrinsics instead.
>
How is it `correct' code when alignment of p is unknown? Do you
mean you are expecting GP.
--
H.J.
