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

[John Rose]

Here is an updated patch for what used to be N-ary MethodApply nodes.

At Remi Forax's suggestion, the N-ary argument list has been moved into the CONSTANT_InvokeDynamic entry, and the CONSTANT_MethodApply type has been deleted.

This code passes a unit test with both trivial and non-trivial argument lists.
It also passes -XX:+StressMethodComparator, which walks all over the constant pool.

Please re-review.

-- John

On Sep 20, 2010, at 12:57 AM, Christian Thalinger wrote:

> On Wed, 2010-09-15 at 01:22 -0700, John Rose wrote:
>> On Sep 14, 2010, at 7:55 PM, John Rose wrote:
>> 
>>> Here's the update:
>>> 
>>> http://cr.openjdk.java.net/~jrose/6984311/webrev.01/
>>> 
>>> Note:  I may ask for review of an alternative form of this change set, which uses N-ary instead of binary nodes in the constant pool.  The EG is discussing both options.
>> 
>> I did the variation which supports N-ary MethodApply nodes.  It is somewhat less natural than the binary MethodApply nodes, because constant pools contain mostly binary nodes, but it matches the meaning of the constants better to allow them to be N-ary.  And the extra data structure is pretty simple.  See what you think.
>> 
>> http://cr.openjdk.java.net/~jrose/6984311/webrev.01.nary
>> 
>> (These are only the diffs from the binary to the N-ary version.)
> 
> src/share/vm/classfile/classFileParser.cpp:
> 
> +          cfs->guarantee_more(3, CHECK);  // operand_count, ..., tag/access_flags
> +          u2 op_count = cfs->get_u2_fast();
> +          cfs->guarantee_more(2*op_count + 1, CHECK);
> 
> I think the additional +1 is wrong as you check for 3 in the first
> guarantee_more.
> 
> Otherwise it looks good.
> 
> -- Christian
>