Re: Performance Characteristics

[James Clark <jjc@xxxxxxxxxx>]

At 20:08 20/04/97 +0100, David Halls wrote:
>> For relatively straight-forward requirements, Jade is astoundingly
>> fast -- I can format a 150-page book on my 75MHZ Pentium notebook
>> (16MB RAM) in under ten seconds, using either Linux or Win95 -- but
>> advanced or unusual requirements could slow that down a bit.
>
>Sounds good so this is probably irrelevant: Is the DSSSL interpreted;

Jade has a virtual machine architecture: it compiles expressions into a DAG
of instruction objects which it then executes.  It's obviously not as fast
as compiling to native code, but it's a lot faster than a pure interpreter.
Jade's inner loop is literally this (in VM::eval):

  while (insn)
    insn = insn->execute(*this);

>if so, would the ability to precompile a dsssl stylesheet into native code
>be useful?

I doubt it would actually speed things up very much.  I haven't done much
profiling, but most of the execution time appears to be spent executing
primitives or outside of evaluating expressions altogether.

James