MEX=/usr/local/matlab/bin/mex
FORTRAN = gfortran
FFLAGS = -c -fpic -O3  -fopenmp
MEXLIB = -fopenmp

OBJS=
file.o
file2.o

all: file1 file2 mex

mex: a.out $(OBJS)
$(MEX) -O a.out $(OBJS) $(MEXLIB)

file1: file1.f
$(FORTRAN) $(FFLAGS) file1.f

file2: file2.f
$(FORTRAN) $(FFLAGS) file2.f

Unknown MEX argument '-fopenmp'.