How about the JIT engine then.
When does parrot use it?
how well does it scale? ( has anyone done some benchmarking )
On Thu, 11 Apr 2002, [iso-8859-1] Jonathan E. Paton wrote:
> > Where in the parrot code does the actual translation
> > from byte code to binary code occur?
>
> Parrot eq. an interpreter, all the byte codes are like
> commands to tell it what actions to take... it doesn't
> directly take byte codes and turn them into binary code.
>
> Conversion would be compiling, but the benefit of using
> bytecode is that if parrot compiles then the bytecode
> can be executed. This is not like gcc's internal
> bytecode, which is just an intermediate step.
>
> Parrot works rather like this simple RPN evaluator:
>
> #!/usr/bin/perl -w
>
> use strict;
>
> my @stack;
>
> # Setup function table and pattern
> my %ops = ( '+' => sub { $stack[-2] += pop @stack },
> '-' => sub { $stack[-2] -= pop @stack },
> '*' => sub { $stack[-2] *= pop @stack },
> '/' => sub { $stack[-2] /= pop @stack },
> '^' => sub { $stack[-2] ^= pop @stack },
> '!' => sub { $stack[-1] = fact($stack[-1]) },
> 'd' => sub { pop @stack },
> 'p' => sub { print $stack[-1] },
> 'P' => sub { print pop @stack },
> 'r' => sub { return $stack[-1] },
> 's' => sub { @stack[-2,-1] = @stack[-1,-2] },
> 'c' => sub { @stack = () }
> );
>
> # Create re patterns
> my $ops = join("|", map { quotemeta } keys %ops);
> my $num = qr/\d+(?:\.\d+)?/;
>
> # RPN Expression Evaluator
> sub eval_RPN {
> local $_ = shift;
>
> while (/($ops|$num|\s+|.+)/go) {
> my $token = $1;
>
> if (exists $ops{$token}) {
> $ops{$token}();
> }
>
> elsif ($token =~ /\s+/) {
> # Do nothing
> }
>
> elsif ($token =~ /^$num$/) {
> push @stack, $token;
> }
>
> else {
> die "Don't know what to do with: $_";
> }
> }
> return pop @stack;
> }
>
> sub fact {
> my ($x, $e) = (abs int shift, 1);
> while ($x>1) { $e*=$x-- }
> return $e;
> }
>
> ### TEST ###
> print eval_RPN(join " ", @ARGV);
>
> __END__
>
> I wrote that one a while back... every programmer
> has written one. Try:
>
> ../rpn 1 2 '+' 4 '*' p
>
> to get a feel of what it does. It mimicks the dc
> command.
>
> Now, back to the topic:
>
> > where does it get executed?
>
> In C.
>
> > Im having a hard time finding things in the code...
>
> I haven't looked at the code, so don't feel bad :P
>
> Jonathan Paton
>
> __________________________________________________
> Do You Yahoo!?
> Everything you'll ever need on one web page
> from News and Sport to Email and Music Charts
> http://uk.my.yahoo.com
>
