use Perl

• op code bloat (Score:1)

  by 2shortplanks (968) on 2002.05.03 5:56 (#7927) Homepage Journal

  First up: Very Cool. However, I'm getting a bit lost on the hand waving here.

  What actually converts the JBC into PBC? Are you doing this by hand atm (i.e. converting JBC to parrot assembler, then assembling it,) or is there some form of automated system?

  As I understand it you're adding new op codes to the pvm so that you have a one to one translation for JBC and PBC. Doesn't this add more operations to the VM? Don't adding more operations slow down the VM implementation (because each operation takes longer to look things up?)

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  • Re:op code bloat (Score:2)

    by acme (189)

    Yes, there is a lot of handwaving ;-)
    
    It was just weekend project, so I converted the JBC into PBC by hand. As I work on this more, I'll be using Java::JVM::Classfile to do it automatically.
    
    This does indeed mean adding more opcodes to Parrot. Parrot has around 600 opcodes already and I added 14. If I added all ~255 JVM opcodes, it would indeed increase the total number of Parrot opcodes, but the slowdown is pretty small. In fact, Parrot will have dynamically loadable opcode libraries, so in future this slo
    • Re:op code bloat (Score:1)

      by 2shortplanks (968)

      Does this mean that you can have numerous different Parrot Byte Codes and a PBC file will have to say what encoding scheme (what opcodes mean what) it is?

      /me waves hands too
      • Re:op code bloat (Score:2)

        by acme (189)

        Possibly. I think we're actually concentrating on getting Parrot working before doing all the magic clever stuff ;-)