Mixing Intel Fortran and PGI Fortran

Accelerated Computing HPC Compilers Legacy PGI Compilers
1

Hello.

I’m targeting a machine which has both NVIDIA GPU and Intel Xeon Phi.

Therefore I want to use CUDA Fortran as well as Intel offload directives. (I don’t really prefer using OpenACC for targeting Xeon Phi.)

So, I want to know if mixing Intel Fortran and PGI Fortran is theoretically possible through a C interface.

Although mixing Intel Fortran and PGI Fortran directly does not work, since GCC is interoperable with both Intel and PGI, I think it will be possible.

Or if you have some better ideas instead of mixing compilers, please tell me.

2

To mix the Intel and PGI fortran objects into the same executable, requires
some care. You have to decide which compiler will compile sources with I/O stmts, and which compiler is only going to compile subroutines or functions
with a Fortran 77 ‘pass by address’ argument interface. Difficult to debug.

Linking with C objects should be done using ISO_C_BINDINGs, which both
compilers will support.

It may be better to use OpenACC '-ta=tesla,multicore ’ with PGI compilers, and
see if the Phi runs the multicore part (when you set ENV variables to run
on the host only).

Or, create a source that compiles for Phi with Intel compilers,
and compiles for OpenACC/CUDA Fortran with pgfortran.

dave