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

[Roland Westrelin]

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.
>>>>>>>>>>>> 
>>>>>>>>>> 
>>>>>>>> 
>>>>>> 
>>>>> 
>>> 
>>