RFR(XS): 8026959: assert(!n->pinned() || n->is_MachConstantBase()) failed: only pinned MachConstantBase node is expected here

[Igor Veresov]

Thanks for the explanation. No, I think it'll be too complicated. Looks good.

igor

On Oct 21, 2013, at 10:48 PM, Rickard Bäckman <rickard.backman at oracle.com> wrote:

> Igor,
> 
> it would be easy to check that the control of a phi isn't NULL.
> If we have an out edge from the MathExact and the Phi and MathExact have the same control checking that it is also used as an input is a bit more work since there can be nodes in between.
> Should I add a graph traversal?
> 
> Thanks
> /R
> 
> 
> On 10/21, Igor Veresov wrote:
>> Would it be prudent to verify (via an assert) all these assumptions about the graph shape you list in the comments?
>> 
>> igor
>> 
>> On Oct 21, 2013, at 6:39 AM, Rickard Bäckman <rickard.backman at oracle.com> wrote:
>> 
>>> Hi,
>>> 
>>> can I have reviews for this small change?
>>> The problem is we are moving a Phi node that is both input and output to
>>> a MathExactNode.
>>> 
>>> Unfortunately cr.openjdk.java.net is down at the moment. I'm pasting the
>>> diff below.
>>> 
>>> diff --git a/src/share/vm/opto/compile.cpp b/src/share/vm/opto/compile.cpp
>>> --- a/src/share/vm/opto/compile.cpp
>>> +++ b/src/share/vm/opto/compile.cpp
>>> @@ -3004,6 +3004,10 @@
>>>      if (result != NULL) {
>>>        for (DUIterator_Fast jmax, j = result->fast_outs(jmax); j < jmax; j++) {
>>>          Node* out = result->fast_out(j);
>>> +          // Phi nodes shouldn't be moved. They would only match below if they
>>> +          // had the same control as the MathExactNode. The only time that
>>> +          // would happen is if the Phi is also an input to the MathExact
>>> +          if (!out->is_Phi()) {
>>>          if (out->in(0) == NULL) {
>>>            out->set_req(0, non_throwing);
>>>          } else if (out->in(0) == ctrl) {
>>> @@ -3012,6 +3016,7 @@
>>>        }
>>>      }
>>>    }
>>> +    }
>>>    break;
>>>  default:
>>>    assert( !n->is_Call(), "" );
>>> 
>>> 
>>> Thank you
>>> /R
>> 
> /R