RFR(M): 8027422: assert(_gvn.type(obj)->higher_equal(tjp)) failed: cast_up is no longer needed

Fri Jan 17 16:35:49 PST 2014

Very good.

Thanks,
Vladimir

On 1/17/14 2:19 AM, Roland Westrelin wrote:
> What about this?
>
> http://cr.openjdk.java.net/~roland/8027422/webrev.03/
>
> Roland.
>
>
> On Jan 16, 2014, at 10:11 AM, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:
>
>> On 1/16/14 1:05 AM, Roland Westrelin wrote:
>>>
>>> Thanks for reviewing this, Christian.
>>>
>>>> Seeing all these:
>>>>
>>>> true /* include_speculative */
>>>>
>>>> I wonder if we should add new methods for these.  It would make it easier to see the users of the speculative versions.
>>>
>>> A new meet_speculative() method?
>>> I’m ok with it. Vladimir, what do you think?
>>
>> I was going to suggest it too but then you need additional methods for other methods: join(), higher_equal(), filter(). So I am fine with it if you do all of them.
>>
>> Vladimir
>>
>>>
>>> Roland.
>>>
>>>>
>>>> On Jan 14, 2014, at 7:25 AM, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:
>>>>
>>>>> Looks good to me.
>>>>>
>>>>> On 1/14/14 1:13 AM, Roland Westrelin wrote:
>>>>>> http://cr.openjdk.java.net/~roland/8027422/webrev.02/
>>>>>>
>>>>>> I fixed the verification code at the end of Compile::remove_speculative_types(), used this format everywhere:
>>>>>> t->filter(_type, true /* include_speculative */);
>>>>>>
>>>>>> renamed NodeHash::check_speculative_types() to NodeHash::check_no_speculative_types(), added PhaseIterGVN::check_no_speculative_types() and now call it from the verification code of Compile::remove_speculative_types().
>>>>>>
>>>>>> Do I need more than 1 review for this?
>>>>>
>>>>> Yes, you need an other review for this change. Ask Chris or Igor.
>>>>>
>>>>> Thanks,
>>>>> Vladimir
>>>>>
>>>>>>
>>>>>> Roland.
>>>>>>
>>>>>>
>>>>>> On Jan 13, 2014, at 11:03 AM, Roland Westrelin <roland.westrelin at oracle.com> wrote:
>>>>>>
>>>>>>>> compile.cpp: new verification code (under ASSERT) at the end of remove_speculative_types() checks only the root node - nothing else is pushed on worklist. Also add comment to this new code.
>>>>>>>
>>>>>>> Thanks for catching that.
>>>>>>> Is:
>>>>>>> // Verify that after the IGVN is over no speculative type has resurfaced
>>>>>>> good as a comment?
>>>>>>>
>>>>>>>> Passing 'true' parameter is not very informative. You can use local variable:
>>>>>>>>
>>>>>>>> bool include_speculative = true;
>>>>>>>> t->filter(_type, include_speculative);
>>>>>>>>
>>>>>>>> An other way to make code more informative is to add a comment to parameter:
>>>>>>>>
>>>>>>>> t->filter(_type, true /* include_speculative */);
>>>>>>>>
>>>>>>>> Either way is fine.
>>>>>>>
>>>>>>> Will do one of these.
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Roland.
>>>>>>>
>>>>>>>>
>>>>>>>> Thanks,
>>>>>>>> Vladimir
>>>>>>>>
>>>>>>>> On 1/10/14 1:46 AM, Roland Westrelin wrote:
>>>>>>>>> Hi Vladimir,
>>>>>>>>>
>>>>>>>>> Here is a new webrev for this:
>>>>>>>>> http://cr.openjdk.java.net/~roland/8027422/webrev.01/
>>>>>>>>>
>>>>>>>>> I fixed the issues you mentioned in your review.
>>>>>>>>> I added a call to remove_speculative() to the ConNode constructor. When a node becomes constant, its speculative part can be not null. The IGVN doesn’t kill ConNodes so without a call to remove_speculative() a ConNode with a speculative part can sneak past the call to Compile::remove_speculative_types().
>>>>>>>>> I also added a verification method:
>>>>>>>>> NodeHash::check_speculative_types()
>>>>>>>>> to check that no TypeNode with a speculative type is still in the IGVN hash table after Compile::remove_speculative_types()
>>>>>>>>>
>>>>>>>>> Roland.
>>>>>>>>>
>>>>>>>>> On Nov 19, 2013, at 8:49 PM, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:
>>>>>>>>>
>>>>>>>>>> On 11/19/13 11:45 AM, Roland Westrelin wrote:
>>>>>>>>>>> Thanks for reviewing this, Vladimir.
>>>>>>>>>>>
>>>>>>>>>>> On Nov 19, 2013, at 1:34 AM, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:
>>>>>>>>>>>
>>>>>>>>>>>> Next 2 places in type.cpp pass 'true' to meet() unconditionally:
>>>>>>>>>>>>
>>>>>>>>>>>> 1929     return TypeAry::make(_elem->meet(a->_elem, true),
>>>>>>>>>>>>
>>>>>>>>>>>> 3812     const TypeAry *tary = _ary->meet(tap->_ary, true)->is_ary();
>>>>>>>>>>>>
>>>>>>>>>>>> Should TypeAryPtr::remove_speculative() also clean _speculative in element's type?
>>>>>>>>>>>
>>>>>>>>>>> You’re right. It probably should.
>>>>>>>>>>> So I need to add a remove_speculative() method to TypeAry. Then the 2 places where true is passed to meet() for TypeAry don’t matter anymore because remove_speculative() is called from meet() and remove_speculative now has an effect on TypeAry, right?
>>>>>>>>>>
>>>>>>>>>> Right, passing 'true' will work in all cases then.
>>>>>>>>>>
>>>>>>>>>> Thanks,
>>>>>>>>>> Vladimir
>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>> Could you make printing code with 'this_t' aligned again in Type::meet()?
>>>>>>>>>>>
>>>>>>>>>>> Sure.
>>>>>>>>>>>
>>>>>>>>>>> Roland.
>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> thanks,
>>>>>>>>>>>> Vladimir
>>>>>>>>>>>>
>>>>>>>>>>>> On 11/18/13 1:15 PM, Roland Westrelin wrote:
>>>>>>>>>>>>> The root of the problem is that during the null check when the type of obj is improved in GraphKit::cast_not_null():
>>>>>>>>>>>>> const Type *t_not_null = t->join(TypePtr::NOTNULL, true);
>>>>>>>>>>>>> The join with TypePtr::NOTNULL is not applied to the speculative part. In fact, no meet between a TypeOopPtr and a TypePtr modifies the speculative part. One way to fix it would be to apply the meet with a TypePtr to the speculative part as well as the standard part of the type which I tried: then we need to move the _speculative field up in TypePtr and modify all operations on TypePtr to operate on _speculative so that the type system remains symmetric.
>>>>>>>>>>>>> In many places where we mix a TypePtr with a TypeOopPtr we actually don’t care about the speculative part. I changed the following operations on Type:
>>>>>>>>>>>>> higher_equal()
>>>>>>>>>>>>> meet()
>>>>>>>>>>>>> join()
>>>>>>>>>>>>> filter()
>>>>>>>>>>>>> so that by default they don’t return a result that include the speculative part of the type. Where we need the speculative part of the type, we have to explicitly request it.
>>>>>>>>>>>>>
>>>>>>>>>>>>> I also fixed a problem with Type nodes with a _type of TypeNarrowOop that wouldn’t drop the speculative part of the type during Compile::remove_speculative_types().
>>>>>>>>>>>>> I included small clean ups that Mikael suggested privately (dropped the duplicate check for res->isa_oopptr() in TypeOopPtr::meet, make remove_speculative not go through the exercise of creating a new type if speculative is NULL).
>>>>>>>>>>>>>
>>>>>>>>>>>>> http://cr.openjdk.java.net/~roland/8027422/webrev.00/
>>>>>>>>>>>>>
>>>>>>>>>>>>> Roland.
>>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>
>>>>>>>
>>>>>>
>>>>
>>>
>