If you want “-mpentium”, you need at least GCC 2.8.1. I think they dropped DOS target circa version 0.100 (2005?), and nowadays MAME is modern C++ (AFAIK). MAME 0.1 only supported five games, right? Of course, later versions got more games but ran much slower.
So for our fun, we will need my cross DJGPP v2 tool chain for win32, MAME 0.1, Allegro 3.12 and Synthetic Audio Library (SEAL) Development Kit 1.0.7. It took a bit of messing around building certain portions inside of each step of the tools, but after a while I had a satisfactory chain capable of building what I had needed. Why not use a more up to date version of both GCC/Binutils? Well the problem is that the pre EGCS tools ended up with macro and inline assembly directives that were dumped along the way so that later versions simply will not assemble any of the later video code in Allegro, and a lot of the C needs updating too. And it was easier to just get the older tool chain working. So as promised, a while back I had built a GCC 2.7.2.3 / Binutils 2.8.1 cross compiler toolchain suitable for building old Allegro based programs, such as MAME. Of course the #1 reason why I’d want such a thing is that being able to do native builds on modern machines means that things compile in seconds, rather than an hour + compiling inside of DOSBox.