On Fri, Jan 8, 2016 at 1:43 PM, H.J. Lu <hjl.to...@gmail.com> wrote:
> 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);
>> }
>>
>
Is a bad example:
extern __inline void __attribute__((__gnu_inline__, __always_inline__,
__artificial__))
_mm256_store_ps (float *__P, __m256 __A)
{
*(__m256 *)__P = __A;
}
since it doesn't use builtin.
--
H.J.
