Invokedynamic and recursive method call

[Vladimir Ivanov]

Remi, thanks for the report!

Filed JDK-8072008 [1].

Best regards,
Vladimir Ivanov

[1] https://bugs.openjdk.java.net/browse/JDK-8072008

On 1/30/15 4:03 AM, Remi Forax wrote:
>
> On 01/30/2015 01:48 AM, John Rose wrote:
>> On Jan 7, 2015, at 8:13 AM, Remi Forax <forax at univ-mlv.fr
>> <mailto:forax at univ-mlv.fr>> wrote:
>>>
>>> But if fibo is called through an invokedynamic, instead of emitting a
>>> direct call to fibo,
>>> the JIT generates a code that push the method handle on stack and
>>> execute it
>>> like if the metod handle was not constant
>>> (the method handle is constant because the call at depth=1 is inlined !).
>>
>> Invocation of non-constant MH's had a performance regression with the
>> LF-based implementation.
>> As of JDK-8069591 they should be no slower and sometimes faster than
>> the old implementation.
>> — John
>>
>
> In my case, the method handle is constant (I think it's also the case
> when you write fibo in javascript).
> At depth=1, the call is correctly inlined.
> At depth=2, the call is not inlined because it's a recursive call and by
> default hotspot only inline recursive call once,
> this is normal behavior. The bug is that instead of doing a call (using
> the call assembly instruction),
> the JIT pushes the method handle on stack and do an invokebasic, which
> is slower.
>
> Rémi
>
>
>
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