At 01:57 PM 9/2/2001 -0400, Ken Fox wrote:
>"Bryan C. Warnock" wrote:
> > I think the only way your going to be able to detect dynamic redefinitions
> > is dynamically. :-)
>
>Not really. Does the program include string eval? That throws out
>optimizations like folding and dead code elimination that use *any*
>global. If the program re-defines a single sub using an assignment to
>a symbol table slot, then only that sub limits optimization. The
>optimizer starts with a set of assumptions and alters those assumptions
>as it sees more of the program.
The more I think about the potential for runtime redefinition, the more I
think having an "if optmized" op is of limited use. Certainly useful for
the "use inlined/use non-inlined" case (to some extent) but there's a lot
of redefinition that can really screw with some of the things that perl can
potentially do.
We do, after all, have the possibility of having *all* our source (or all
our bytecode, which is enough for the optimizer) at hand, something most
other languages don't have. (Try building perl 5 as one big source file.
You get around a 5% speedup last I knew, because the compiler could see all
the source) That means we can sort of maybe more aggressive in our
optimizations, since there's less entropy in the system. (Well, from the
invisible source front, at least)
Dan
--------------------------------------"it's like this"-------------------
Dan Sugalski even samurai
[EMAIL PROTECTED] have teddy bears and even
teddy bears get drunk
