Good news, bad news

[Charles Oliver Nutter]

On Mon, May 23, 2011 at 7:41 PM, John Rose <john.r.rose at oracle.com> wrote:
>> I'm still unclear why you couldn't write your own variant of guardWithTest and have it work but my knowledge of what's really allowed is somewhat limited.
>
> Those snippets will inline (I think), but at some point Charlie will want to fetch a bit of constant stuff out of an instance variable.  That will look non-constant to the optimizer, even if the instance variable is final and the enclosing object is a constant reference.  We made sure this happens for java.lang.invoke classes, but we haven't extended it yet to user code, in part because it would have its own bug tail to work through.

That's what I figured. See the diff I just posted that basically does
GWT by hand.

This also plays into the pre/post logic discussion too...ideally there
would be a way to indicate to the JVM that my hand-written Java code
should be specialized on a per-callsite or per-MH-chain basis, so I
could reuse the same code many places without it going all megamorphic
on me.

You say "haven't extended it yet to user code"...which gives me hope
for 1.7.0_1 potentially introducing it :)

If I can get past this invokeExact exception, I'll let you know how
inlining looks in a polymorphic case.

- Charlie