About porting GCC to backends which have a small number of registers. ....

[Basile Starynkevitch]

>> To give just one small practical example, I'm told (by people who are more
>> familiar with GCC internals than I) that it is not feasible with today's
>> GCC to port to backends which have a small number of registers.

I think (not sure) that could be attributed to 
john@darrington.wattle.id.au - apologies if I am wrong.


Why?


GCC is doing many optimisations at the GIMPLE level.

Why won't it be possible (even if very painful) to transform GIMPLE to 
some architecture with very few registers.

IIRC, the TMS9900 (a microprocessor from texas instruments, in 1976) had 
very few hardware registers. One of them being a "pointer" to some 
"virtual register bank" on the call stack.

http://www.bitsavers.org/components/ti/TMS9900/TMS_9900_Microprocessor_Data_Manual_May76.pdf

I don't seen any impossibility in generating such instructions from GIMPLE.

Of course, I am not candidate to do so...

Cheers


-- 
Basile Starynkevitch                  <basile@starynkevitch.net>
(only mine opinions / les opinions sont miennes uniquement)
92340 Bourg-la-Reine, France
web page: starynkevitch.net/Basile/