AVX types: __m256d versus __v4sd

[Marc Glisse <marc.glisse@xxxxxxxx>]

Hello,

I noticed that the AVX vector of 4 double has 2 names, __v4sd and __m256d 
(actually we have the same duality for SSE), and I'd like to know when I 
should use which name.

The only difference is the may_alias attribute. I expect that casting a 
__v4sd* to a double* doesn't require the may_alias attribute, and that 
problems only start if I try casting a __v4sd* to a __v4di*?

On the other hand, Intel only documents __m256d (the may_alias version), 
so portability says to use that one.


--
Marc Glisse