[9] RFR(XS): 8042052: assert(t != NULL) failed: must set before get

[Niclas Adlertz]

Hi Tobias,

Thank you for catching this.
I would say you can then change "_gvn.transform(result)" to just 
"result" inside "inline_pow()", after the call to "finish_pow_exp()" at 
line 1931:

From:
// the result from finish_pow_exp is now input to the phi node 
 
 

phi_node->init_req(2, _gvn.transform(result));

To:
phi_node->init_req(2, result);

since "result" has already been returned from "_gvn.transform()" either 
inside "finish_pow_exp" or before the call, inside "inline_pow()".

Also since "_gvn.transform()" possibly returns a new node, this:
// Make sure type of PhiNode is recorded
_gvn.transform(result_val);
return result_val;

should be replaced with:
return _gvn.transform(result_val);

(I don't think the comment is nescessary since we need to record nodes 
at many other places as well)

Kind Regards,
Niclas Adlertz

On 04/30/2014 04:30 PM, Tobias Hartmann wrote:
> Hi,
>
> please review the following patch for bug 8042052.
>
> *Problem*
> The changes introduced by the fix for 8041912 [1] removed the call to
> set_result(...) in LibraryCallKit::finish_pow_exp(...) that called
> gvn.transform on the PhiNode results_val. The type of the PhiNode is
> therefore not recorded in the gvn. The PhiNode is returned and later
> accessed as an input to a StoreNode in
> PhaseGVN::transform_no_reclaim(...). The call to StoreNode::Value tries
> to look up the type of the PhiNode and triggers the assert in
> PhaseTransform::type(...) because the type is not set.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8042052
>
> *Solution*
> A call to _gvn.transform is added to make sure the type of the PhiNode
> is recorded.
>
> Webrev: http://cr.openjdk.java.net/~anoll/8042052/webrev.00/
>
> *Tests:*
> Failing test (testMathExpDouble), JPRT
>
> Thanks,
> Tobias
>
> [1] https://bugs.openjdk.java.net/browse/JDK-8041912
>