Request for reviews (S): 7011839: JSR 292 turn on escape analysis when using invokedynamic

[Christian Thalinger]

Vladimir, could you please review this change?  -- Christian

On Jan 13, 2011, at 1:17 PM, Christian Thalinger wrote:
> On Jan 13, 2011, at 12:00 AM, John Rose wrote:
>> On Jan 12, 2011, at 5:46 AM, Christian Thalinger wrote:
>> 
>>> http://cr.openjdk.java.net/~twisti/7011839/webrev.01/
>> 
>> The arg_size computation is very fragile.  To start with, the arg_size value should be computed in one place.
>> 
>> As the code is written, arg_base points at the implicit argument to indy, which (I think) is not really on the stack.
>> 
>> I suggest this code:
>> 
>> 234   // compute size of arguments
>> 235   int arg_size = target->arg_size();
>>         if (code == Bytecodes::_invokedynamic) {
>>           assert(!target->is_static(), "receiver explicit in method");
>>           arg_size--;  // implicit, not really on stack
>>         }
>> 236   if (!target->is_loaded() && code == Bytecodes::_invokestatic) {
>>           assert(!target->is_static(), "receiver explicit in unloaded method");
>> 237     arg_size--;
>> 238   }
> 
> I like that better.  I'd like to keep the invokedynamic check as I couldn't reproduce any escaping case with an invokedynamic call site (using Indify).  I think the reason is because they all bail before out as native call sites.
> 
>> 
>> The second assertion is for good measure.  The bare "arg_size--" makes me nervous.
> 
> We can't use that assert since ciMethod::is_static uses check_is_loaded which asserts on is_loaded.
> 
> http://cr.openjdk.java.net/~twisti/7011839/webrev.02/