"Armin Vogl" <[EMAIL PROTECTED]> writes: > I would like to ask if it would be possible to write a gcc backend for the > Xilinx PicoBlaze soft processor.
Porting gcc to an 8-bit microcontroller is not completely impossible, but it is not easy. gcc was written to generate code for 32-bit processors, and tends to get in a register crunch on very small processors. While I didn't look at the PicoBlaze docs at all, small processors also tend to have specialized addressing modes which tend to confuse gcc. Fixing these problems in a gcc port tends to put you into the most complex part of the compiler, which is reload. > As I have never programmed anything like a compiler and am > not familiar with gcc, I would like to ask how much time it would > need to implement a backend. Is it realistic to do it myself or is > there a place to request the addition of a backend. > > Is it realistic for somebody with zero gcc experience to implement a backend > in a reasonable time (whatever that may mean :) ? It's obviously hard to say. There is fairly decent documentation and there are plenty of existing examples. One advantage of a small processor is that there isn't all that much to implement--it's mostly debugging. An excellent programmer could probably get up to speed and do the backend port in a few months. (For comparison, I've written a few gcc backend ports already, and last year I did a port to a 16-bit microcontroller in less than a month, but the chip had the advantage of having 16 registers and only one addressing mode (register indirect)). There is no place to request a backend port, other than the e-mail you sent. Most such requests go unanswered. A backend port is hard enough that most people wouldn't do one without a good reason. Ian
