[11] RFR(XS): 8202179: Compilation fails with assert(n->is_expensive()) failed: expensive nodes with non-null control here only

[Vladimir Kozlov]

Good.

thanks,
Vladimir

On 4/26/18 8:59 AM, Tobias Hartmann wrote:
> Hi Vladimir,
> 
> On 26.04.2018 17:47, Vladimir Kozlov wrote:
>> Should we also check in(0) for NULL in Node::is_unreachable() ? I know that is called only for
>> expensive nodes *now* but still it should check for 0.
> 
> Okay, let's do that:
> http://cr.openjdk.java.net/~thartmann/8202179/webrev.01/
> 
> Thanks,
> Tobias
> 
>> On 4/26/18 12:05 AM, Tobias Hartmann wrote:
>>> Hi,
>>>
>>> please review the following patch:
>>> https://bugs.openjdk.java.net/browse/JDK-8202179
>>> http://cr.openjdk.java.net/~thartmann/8202179/webrev.00/
>>>
>>> Expensive nodes have control inputs to prevent GVN from commoning them which may cause more frequent
>>> execution (see comment of PhaseIdealLoop::process_expensive_nodes()).
>>> Compile::cleanup_expensive_nodes() assumes no expensive nodes are added after parsing and removes
>>> the control input if there's only a single copy of a node. ConvD2FNode::Ideal() then creates a new
>>> SqrtFNode with the control of the input SqrtDNode (which is NULL).
>>>
>>> We should only treat the SqrtFNode as expensive if the control input is not NULL.
>>>
>>> I was only able to reproduce this with replay compilation and a customer application.
>>>
>>> All tests pass.
>>>
>>> Thanks,
>>> Tobias
>>>