On 20 August 2013 03:13, LMH <lmh_users-gro...@molconn.com> wrote: > I would be happy to build gcc-3 myself, I'm just looking for some > documentation to get that done. > > The fact the gcc-3/g77 are old means nothing to me. There are still millions > of lines of fortran77 code out there that are being used. There is just no > reason to spend years of man hours to update the code and result in new code > that gives the exact numerical answers as the old code. I already work 80, > and sometimes even 100 hours in a week developing new material. The less > time I have to spend on projects that already work as is, the better. The > last time I checked, important linux distros used in industry (Cent, Suse, > etc) all still included legacy gcc3 development support. If you think about > the investment in gcc3 based code that is out there, and the time that could > be required to port that to gcc4, keeping the legacy support makes allot of > sense. > > When gcc4 first came out, I tried moving. I was able to get my code to > compile and link after making allot of changes to the header files, but I > got different numerical answers on my data for some cases. This is the real > bugbear.
gfortran is not considered a bugbear since about gcc 4.1. Its developers are committed to considering any standard Fortran 77 code that does not compile or gives wrong results on gfortran a bug. > When you change compilers, everything has to be QC'd again. I tried > again with gcc4.3, and found again that many header files had changed and it > took quite a bit of work to get it to compile. When I did get it to work, I > now got the same numerical answers as with gcc3. This underscores some of > the issues that can happen when you change compilers, especially if the > compiler is a relatively new version. Imagine some of the disasters that > could have happened if I based research on the incorrect values from > software compiled under the early versions of gcc4!!! There have also been > allot of issues with folks trying to compile f77 code under gfortran. > > In many cases, there is just no good reason to move compilers when you have > mature src code that has been optimized and QC'd for 30+ years. Why would > you want to put ANY time into maintaining such code? I used to write a lot of Fortran 4 code back in 198*ies... Should I demand an IBM-360 Fortran 4 compiler being distributed? :-) > That is not a > rhetorical question, so if there are some good reasons to move to newer > versions of gcc, I would be interested in hearing the arguments. Putting in > time to revise code and end up with the identical assembler is not something > I am all that interested in. > Identical assembler? Come on, do you want your executables optimized for i486 ? Then yes, you might want to us gcc3. :-) Also it's obvious that most of Fortran 77 code had been developed not on g77, but using other compilers, mostly dead by now. After all, being a cross-compiler, g77 is mostly a quick hack. Dmitrii -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
