Re: State of gcc 2.95 use in Debian unstable
Heiko Müller wrote:
> Dear Thiemo,
> we very much appreciate your work on the gcc-2.95 debian package.
> For us - and probably also for other users in the scientific
> community - the "old" compiler version is still of great value.
>
> We use gcc-2.95 to compile C/C++ code with very large mathematical
> expressions generated by computer algebra software. This involves
> very long (several thousand lines of code) functions to evaluate
> multi-variable polynomial expression resulting from perturbation
> theoretical solutions of physical problems.
>
> We found that gcc-2.95 -Os produces object code of acceptable quality
> within reasonable compilation times. gcc >=3 is less efficient w.r.t.
> compilation time and memory consumption and in many cases even fails
> to compile our codes due to the very long expressions. The C/C++ codes
> generated from the computer algebra software are perhaps unusual but
> not broken.
Well, gcc 3.x was somewhat disappointing WRT, but I would expect 4.0
to do better. If 4.x fails for your (valid and standard-conforming)
code, please consider to provide a testcase to the upstream developers.
I'm sure they are interested in it, and long-term it will help you as
well to have a more modern compiler which can handle such cases.
> Since what we are doing is not so unusual in theoretical physics we are
> probably not alone with these kind problems. Please consider that even
> if no other debian packages would depend on gcc-2.95 many users may
> very much require it.
Indeed, I got also one private reply which suggested gcc-2.95 is still
an interesting choice for some numerics code.
Thiemo
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