Offloading: libgfortran, libm dependencies

[Bernd Schmidt]

On 10/02/2015 05:20 PM, Thomas Schwinge wrote:
> How should we handle libgfortran and libm dependencies in offloaded code?
>
> As the linking requirements especially regarding libgfortran may be
> different for each offloading target (shared and/or static libraries
> supported, static linking enforced, libquadmath needed, and so on), I
> think the specific configuration must happen inside the offloading
> execution path (mkoffload).  Thus, trying to do this inside the gfortran
> front end, gcc/fortran/gfortranspec.c:lang_specific_driver etc., does not
> appear to be doing it the right way; for offloaded code, we'll always be
> using the lto1 front end instead of the gfortran one.  Is a libgfortran
> link spec like libgomp's, together with some flag (similar to
> -fopenmp/-fopenacc being used with the libgomp link spec) the right thing
> to do?

So I think I'm following your reasoning, and what you suggest may well 
be the best solution. The question then becomes how to decide when to 
pass that new flag. Have f951 put it into the options written into LTO 
somehow?


Bernd