hi there, I've been toying around with a simple language implementation that's emitting M0. The language is very alike C, but much ,much simpler. I'm currently doing the code generation, and found that M0 is missing comparison ops, to implement <, <=, >, >=, == and !=. We don't need all 6, but a few would help. The only way I can think of now to implement comparisons is to use sub, and then look at the result and jump using goto_if. However, I think it's such a common and simple op, in my view it'd be warranted to add a few ops directly to M0 for this.
Comments welcome. kjs On Apr 2, 6:12 pm, Christoph Otto <[email protected]> wrote: > On Sun, Apr 1, 2012, at 23:51, Brian Gernhardt wrote: > > > On Apr 1, 2012, at 11:17 PM, Jimmy Zhuo wrote: > > > > I just realized that M0 is stack based. M0 is dedicated to use the > > > least op to do the work, it's extreme makes it being stack based, > > > not register based. If the latter is more advanced, then it's a > > > retrogression. Here is some compares: > > > > M0: > > > set_imm I0, 0, 123 > > > set_imm I1, 0, 356 > > > add_i I2, I1, I0 > > > > CPU-ish: > > > mov %eax, 123 > > > add %eax, 356 > > > or > > > add %eax, %ebx > > > or > > > add %eax, [0] # [0] is memory unit. > > > or > > > add [0], %eax # [0] is memory unit. > > > > In M0, we can't do this: > > > add_i I2, 123, 356 > > > I have thought it would be nice if M0 had some concept of addressing > > modes. Indirect, indexed, and immediate are things that jump to mind > > quickly. They could be handled by the core runloop before dispatching > > off to the ops for simplicity. > > > ~~ Benabik > > The big goal of M0 is stupid simplicity, but I also don't want > meaningfully efficient execution to require an optimizing assembler. > Adding addressing modes isn't out of the question. > > I'm busier than I should be at the moment, but I'd love to see an > experiment with addressing modes. If either of you have the time, > please feel free to fork the m0 branch and hack out something on > the Perl interpreter. This kind of experimentation is exactly > what it's for. > > Christoph > _______________________________________________http://lists.parrot.org/mailman/listinfo/parrot-dev _______________________________________________ http://lists.parrot.org/mailman/listinfo/parrot-dev
