(j3.2006) (SC22WG5.5902) [ukfortran] 3 levels of parallelism?

[N.M. Maclaren]

OpenAcc has effectively been subsumed into OpenMP. Whether the OpenMP 
'SIMD' features (i.e. OpenAcc) are practical is unclear, and the 
implementation status less so. My very limited feedback from people who 
have tried to use it was highly negative. As far as I know, CUDA looks 
likely to dominate for the forseeable future.

Also, while languages are traditionally descriptive, not prescriptive, 
explicit threading (as in C++ etc.) and coarrays are both prescriptive 
models. In particular, they can't take advantage of SIMD, though Fortran as 
a whole can.

Regards,
Nick Maclaren.