advice on gfortran options for a port

[Tijl Coosemans]

On Sun, 15 Nov 2015 20:43:21 +0100 (CET) Gerald Pfeifer <gerald at pfeifer.com> wrote:
> On Wed, 29 Jul 2015, Tijl Coosemans wrote:
>>> Trying to build (with gfortran48 to gfortran6) I get:
>>> 
>>> f951: sorry, unimplemented: Graphite loop optimizations cannot be used (ISL is not available)(-fgraphite, -fgraphite-identity, -floop-block, -floop-interchange, -floop-strip-mine, -floop-parallelize-all, -floop-unroll-and-jam, and -ftree-loop-linear)
>>> 
>>> Are these not implemented on BSD?
>>> I wonder how they build with GCC with these flags?
>>> 
>>> Anyway, should I leave all these flags, and -ggdb in the port?
>>> Or should I use the default ports tree FFLAGS instead?  
>> It seems that gcc needs to be configured with --with-isl to enable
>> Graphite.  Gerald, can this be enabled in the gcc ports?  
> 
> I just committed a patch to lang/gcc6-devel that adds a new option 
> GRAPHITE which enables support for Graphite loop optimizations and 
> am looking into pushing this back into the gcc5-devel and later 
> gcc5 ports.
> 
> Since this pulls in libisl as an additional dependency and I have 
> only seen two requests for this (including yours) so far, I'm a 
> little hesitant to make enable this option by default.
> 
> What do you think?  (Patch below.)

If upstream disables it by default it's ok to keep the port option
disabled by default too.