f2c (+gcc)

The f2c program comes standard with all GNU/Linux distributions with which I am familiar. The home site of f2c is at AT&T's netlib software repository. f2c converts standard Fortran-77 code to standard C code. On GNU/linux, this is further compiled into assembly by gcc. Three immediate advantages of f2c are: A further advantage, if you are a nuclear or particle physicist, is that Disadvantages of f2c+gcc are that Debugging f2c+gcc-compiled code --- There are two ways to do this: Getting correct results --- schuetze@math.tu-dresden.de (T.Schuetze) pointed out that if one turns on optimization, the "paranoia" suite fails. This can be cured by passing the option -ffloat-store to the gcc phase of the compilation. If you use fort77 as a compiler driver, you can simply specify the option as printed above; some other compiler drivers may require you to pass it to gcc using some special option prefix. -ffloat-store forces all real variables to have their stated (either real*4 or real*8) precision. If you don't specify it, certain variables which only live in registers may have the precision of the Intel FP registers, which is different than real*4 or real*8.
Jeff Templon
Last modified: Wed Apr 11 14:54:45 EDT 2001