advice on gfortran options for a port

[Anton Shterenlikht]

I'm making a port of http://netlib.org/math/

The supplied makefile has:

# This makefile uses features of GNU Make.  Uses bash on Linux.
# Meant to be run from the directory containing the math77 Fortran directory.
# You may need to change the first line above, and the definitions of FC,
# std_flags, and FFLAGS below.  If code is to be used in production,
# you will want to change the optimization level.  (For example change
# -ggdb to -O3 or -O2.

FC = /usr/bin/gfortran
std_flags=-march=native -fimplicit-none -fno-f2c -fno-backslash\
 -funroll-loops  -ffpe-trap=zero,overflow,invalid -finit-real=NAN\
 -ftree-vectorize -floop-interchange -floop-strip-mine -floop-block -pipe

FFLAGS = -ggdb $(std_flags) -Wall

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?

Thanks

Anton