Hi Armin, Armin Rigo wrote:
Actually, my comment about this was guided by the fact that I didn't see how the existing flow graph model can represent stack operations... Antonio, did you have something more precise in mind? A bunch of of operations that have often no argument and/or no return value, but implicitly operate on the stack, e.g. stack_int_mul(), stack_push(v), v=stack_pop()?
Yes, that was precisely what I though, but it seems a little untidy: as you pointed out I think the best way to handle stack machines is to transform SSI operations into a completely new list of stack based operation (or, equivalently, into a complex expression tree).
With this schema we could also easily handle other problems in the future: for example, we could also write a transformer for register-based machines that takes a list of SSI operations and produces a list of operations specifically tailored for that task.
Given this it each backend could choose the "instruction set" that fit best its needs, just as at the moment each backed can choose whether to use lltypesystem or ootypesystem.
Just my 2 euro-cents, ciao Anto _______________________________________________ [email protected] http://codespeak.net/mailman/listinfo/pypy-dev
