Request for reviews (M): 6910618: C2: Error: assert(d->is_oop(),"JVM_ArrayCopy: dst not an oop")

[Vladimir Kozlov]

Thank you, Tom

Bytecode_invoke_at_check() does not check for allocation bytecodes
and the bug case is deoptimization on the return from the call to
OptoRuntime::new_array_C(). So I am nervous about checking only
bytecode since I may miss something.

I will remove printing.

Thanks,
Vladimir

Tom Rodriguez wrote:
> Oh, right, wrong end of the stack.  So then why can't you get it from the bytecodes of the call site of the last scope?
> 
> ScopeDesc* scope = chunk->at(chunk->length() - 1)->scope();
> Bytecode_invoke* invoke = Bytecode_invoke_at_check(scope->method(), scope->bci());
> if (invoke != NULL) {
>   save_oop_result = invoke->result_type() == T_OBJECT;
> }
> 
> I guess it's possible that the site is being handled in some different way such that we don't actually have a real call there, particularly if reexecute were true.  So your fix seems more right.  What do you think about dropping the =true on the printing output since it seems redundant?
> 
> tom
> 
> On Feb 8, 2010, at 11:50 AM, Vladimir Kozlov wrote:
> 
>> Because it will return deoptee (caller method) and not the method
>> from which we returned already (no frame on stack).
>>
>> Vladimir
>>
>> Tom Rodriguez wrote:
>>> Why do you need to record this in the PcDesc?  Why can't you just do:
>>> chunk->at(0)->scope()->method()->return_type() == T_OBJECT
>>> tom
>>> On Feb 8, 2010, at 11:12 AM, Vladimir Kozlov wrote:
>>>> http://cr.openjdk.java.net/~kvn/6910618/webrev.00
>>>>
>>>> Fixed 6910618: C2: Error: assert(d->is_oop(),"JVM_ArrayCopy: dst not an oop")
>>>>
>>>> Problem:
>>>> If deoptimization happened on the return from a call which
>>>> which returns oop, the oop will be not updated during GC which
>>>> is triggered by scalar replaced objects reallocation.
>>>>
>>>> Solution:
>>>> Mark in PcDesc call sites which return oop (this is main part of changes)
>>>> and save the result oop across objects reallocation during deoptimization.
>>>>
>>>> Reviewed by:
>>>>
>>>> Fix verified (y/n): y, test
>>>>
>>>> Other testing:
>>>> JPRT
>>>>
>