I have some old legacy code I'm trying to compile, which was originally compiled on the Lahey LF90 compiler. When I tried compiling using gfortran and then ifort, the program compiled but when running the program I got vastly different results. When I talked to the original author, he said he had to specify -vax while compiling in order to compile code which uses the DEC/VAX and IBM/VS extensions. Rewriting the code is not at all a good option, as the code is ridiculously long and I haven't found any good resources saying how to convert back to regular fortran 77.
I've been trying to find what the equivalent option with ifort is, but all I've found is -Vaxlib (which doesn't appear to exist anymore?) or -vax which didn't work at all, or things saying that it should be done automatically, which obviously wasn't the case. So what do I need to do to compile this code?
Any help would be greatly appreciated, thanks!