review request (L): 6981777 implement JSR 292 EG adjustments from summer 2010

[John Rose]

On Sep 15, 2010, at 2:20 AM, Rémi Forax wrote:

>> http://cr.openjdk.java.net/~jrose/6984311/webrev.01.nary
>> 
>> (These are only the diffs from the binary to the N-ary version.)
>> 
>> -- John
> 
> I prefer the N-ary version :)
> 
> Questions:
>  - Why having two constants InvokeDynamic and MethodApply in that case.
>    Constant arguments are tied to a BSM. I don't think you can reuse
>    array of arguments accross different BSMs.

Your wish is my command, this time :-)

  http://cr.openjdk.java.net/~jrose/6984311/webrev.02/

>  - Why argcount is stored using 2 bytes instead of one ?
>    These arguments are arguments of a Java method (the BSM)
>    which limit the number or argument to 255.


The argument list gets passed to the BSM as a single argument, an Object array of length up to 65535.  This in turn is easy to receive into the BSM as a Java varargs argument (or simple Object[]).

This is easier to implement and far more useful than passing a variable (and limited) number of arguments on the stack.

More details on the mlvm-dev list...

-- John