About
g95 and gfortran
There are quite a few Fortran compilers available. gfortran comes with the Linux
system and you can fetch the Intel-compiler
yourself (provided you have a fair amount of free disk space).
Sun
has other free compilers.
I have fetched an additional Fortran90-compiler. You find it
under /chalmers/sw/unsup/g95/bin/ on the system (not on
www). If you explore /chalmers/sw/unsup/g95
you
will find some documentation as well.
You (may) need to change the LD_LIBRARY_PATH as well (this environment
variable tells the dynamic loader where to look for libraries). I
assume you are using tcsh. To use gfortran type:
setenv LD_LIBRARY_PATH
$LD_LIBRARY_PATH\:/chalmers/sw/unsup/g95/lib/gcc-lib/i686-pc-linux-gnu/4.0.3/
To get faster code -O3 is not enough on some of the tests, you need to
ask the compiler to unroll loops as well.
Type: gfortran -O3
-funroll-loops files... or g95 -O3 -funroll-loops files...