SIMD intrinsics / gcc vectors

[Tobias Burnus]

On 3/11/20 11:01 AM, Richard Biener wrote:
> I think he is talking about using intrinsics to manually write vector

I assumed so – but I thought it might be still useful to list
what is actually supported instead of just saying "no".

> code like those from xmmintrin.h, the C intrinsic headers provide
> vector types and functions to operate on them mapping to CPU

The starting problem is that there is currently no way to create
vector types in gfortran. I thought the Intel Fortran compiler might
support something as vendor extension, but a quick search also only
found annotations like for OpenMP's simd.  (ifort's vector attribute is
more powerful, but I think it also does not permit defining vectors.)

Thus, the first step is to come up with a syntax to specify a vector type.

I am also not sure whether it would get used as most Fortran code is
written such that it is completely hardware/compiler independent. And
there is some opposition among the gfortran developers adding and especially
inventing vendor extensions.

Tobias

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