RFR(S): 8202399:) [C1] LIRGenerator::do_CheckCast needs to exclude is_invokespecial_receiver_check() when using PatchAlot

[Vladimir Ivanov]

> Thanks Vladimir! But as you actually supplied the patch details 
> technically you can't self-review it. :)
Okay. Can you "self-review" it then? :-)

Best regards,
Vladimir Ivanov

> 
> Can I get a "second" review please.
> 
> Thanks,
> David
> 
> On 1/05/2018 7:12 AM, Vladimir Ivanov wrote:
>> Looks good.
>>
>> Thanks a lot for taking care of it!
>>
>> Best regards,
>> Vladimir Ivanov
>>
>> On 4/29/18 20:03, David Holmes wrote:
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8202399
>>> webrev: http://cr.openjdk.java.net/~dholmes/8202399/webrev/
>>>
>>> JDK-8168699 introduced  a special case for 
>>> is_invokespecial_receiver_check() in LIRGenerator::do_CheckCast:
>>>
>>>    } else if (x->is_invokespecial_receiver_check()) {
>>>      assert(patching_info == NULL, "can't patch this");
>>>      stub = new DeoptimizeStub(info_for_exception,
>>>                                Deoptimization::Reason_class_check,
>>>                                Deoptimization::Action_none);
>>>
>>> but overlooked a potential bad interaction with PatchAlot. This can 
>>> lead to  the assertion failure as observed during testing for 
>>> JDK-8200167 with Graal. The proposed fix (supplied by Vladimir) is 
>>> quite simple but needs to be applied to each of the CPU specific files:
>>>
>>> diff --git a/src/hotspot/cpu/x86/c1_LIRGenerator_x86.cpp 
>>> b/src/hotspot/cpu/x86/c1_LIRGenerator_x86.cpp
>>> --- a/src/hotspot/cpu/x86/c1_LIRGenerator_x86.cpp
>>> +++ b/src/hotspot/cpu/x86/c1_LIRGenerator_x86.cpp
>>> @@ -1314,7 +1314,7 @@
>>>      LIRItem obj(x->obj(), this);
>>>
>>>      CodeEmitInfo* patching_info = NULL;
>>> -  if (!x->klass()->is_loaded() || (PatchALot && 
>>> !x->is_incompatible_class_change_check())) {
>>> +  if (!x->klass()->is_loaded() || (PatchALot && 
>>> !x->is_incompatible_class_change_check() && 
>>> !x->is_invokespecial_receiver_check())) {
>>>
>>> Testing:
>>>   - hotspot/jtreg/compiler (complete)
>>>   - hs-comp-precheckin (once mach5 is available)
>>>
>>> Thanks,
>>> David