On 5/25/07, Donal K. Fellows <donal.k.fellows@[...].uk>  wrote:
> 
>  Alexandre Ferrieux wrote:
>  > Now even for upvar, there are possibilities. Since in Tcl [upvar]ed vars
>  > are accessed at runtime, it suffices to maintain enough data for a name
>  > lookup in each stack frame.
> 
>  You are aware that this is very close to what we actually do? :-)


:-)

No, I'm not really aware since I have not read the thorough documentation of
the bytecode VM...

 | The main difference is that variables aren't on the stack anyway, [for
deep reasons]

OK. Then remove the vars-on-stack of my proposal, yielding:

     proc foo {x} {bar $x; ...}
--> 
    .1 .checkargceq CALL
    .x .set CALL
    MARK MARK .x .set CALL .bar CALL

Then, you're saying that *this* is roughly equivalent to the current
bytecode VM ?
Sorry for reinventing that wheel...

So the bottom line is: how to isolate cases where locals (and proc
parameters as a special case) are handled in a completely traditional way
(like in C), and hence can be moved to the stack, right ?

-Alex