What we did was, we used the vendor compilers to compile gcc for a platform (or maybe used gcc to cross-compile itself, I forget). Then we used that gcc to compile gcc for that platform. Then we used the new gcc to compile gcc for that platform, and made sure that it was the same as the previous gcc. This wasn't easy - we had one guy that this is pretty much all he did for months. But it got us to a place where we were free from the vendor compilers.
It was back in the first .com wave, so 1999 - 2002.
> Was gcc an option at that time? Or did management require you to use the vendor compiler?
Customers did. Our software needed to integrate with their existing toolchains.
At least for our customers gcc was not a serious compiler, given the license and being that funny open source thingy.
This was the only time period I used C instead of C++ at work.
However I do confess, the situation for C++ support was even worse, so although I am not fan of C, the decision made sense from business point of view.