replacing nodes with DeoptimizeNodes

[Tom Rodriguez]

It’s probably not the best place to do it, though it could be made to work.  What kinds of operations are you converting into deopts?

tom

On Mar 6, 2014, at 3:25 PM, Deneau, Tom <tom.deneau at amd.com> wrote:

> Yes, it's happening as a result of my conversion of a node into a Deopt
> node?  Which I was trying to do during lowering.  Maybe that's the wrong place to do it?
> 
> -- Tom
> 
>> -----Original Message-----
>> From: Tom Rodriguez [mailto:tom.rodriguez at oracle.com]
>> Sent: Thursday, March 06, 2014 5:17 PM
>> To: Deneau, Tom
>> Cc: Gilles Duboscq; Douglas Simon; graal-dev at openjdk.java.net
>> Subject: Re: replacing nodes with DeoptimizeNodes
>> 
>> 
>> On Mar 6, 2014, at 12:21 PM, Deneau, Tom <tom.deneau at amd.com> wrote:
>> 
>>> OK, and if I get an error like
>>> lowering of NodeA produced lowerable NodeB that should have been
>>> recursively lowered as it introduces these new nodes: [171|Deopt]
>>> 
>>> does that mean I have to write my own lowering for NodeA which as part
>> of that also lowers the replacement nodeB?
>> 
>> Generally any lowering phase is required to finish in a single pass, so
>> if you're lowering is doing anything tricky that introduces Lowerable
>> nodes than you need to manually lower them, usually by running your own
>> LoweringPhase.  When are you getting this message?  MacroNodes do this
>> for instance.
>> 
>> Is this happening as a result of your conversion of a node into a Deopt
>> node?  Are you trying to do that during lowering?
>> 
>> tom
>> 
>>> 
>>> -- Tom
>>> 
>>>> -----Original Message-----
>>>> From: gilwooden at gmail.com [mailto:gilwooden at gmail.com] On Behalf Of
>>>> Gilles Duboscq
>>>> Sent: Wednesday, March 05, 2014 4:29 AM
>>>> To: Doug Simon
>>>> Cc: Deneau, Tom; graal-dev at openjdk.java.net
>>>> Subject: Re: replacing nodes with DeoptimizeNodes
>>>> 
>>>> On Wed, Mar 5, 2014 at 11:18 AM, Doug Simon <doug.simon at oracle.com>
>>>> wrote:
>>>>> 
>>>>> On Mar 5, 2014, at 1:27 AM, Deneau, Tom <tom.deneau at amd.com> wrote:
>>>>> 
>>>>>> Let's say there is some random graal node that you choose not to
>>>> implement so you want it to be replaced by a DeoptimizeNode.  How
>>>> does one do that if the original node is not a terminal node, ie, it
>>>> has usages?
>>>>> 
>>>>> The subgraph rooted at that node has to be removed (probably through
>>>> use of
>>>> com.oracle.graal.nodes.util.GraphUtil.killWithUnusedFloatingInputs(No
>>>> de)
>>>> ).
>>>> 
>>>> Rather GraphUtil.killCFG(Node).
>>>> As an example, you can look at CanonicalizerPhase.performReplacement
>>>> (around line 297):
>>>> //case 7
>>>> fixed.predecessor().replaceFirstSuccessor(fixed, canonical);
>>>> GraphUtil.killCFG(fixed);
>>>> 
>>>> even better would be:
>>>> fixed.replaceAtPredecessor(canonical);
>>>> GraphUtil.killCFG(fixed);
>>>> 
>>>> where in you case fixed is the node you want to replace and canonical
>>>> is the DeoptimizeNode.
>>>> 
>>>>> 
>>>>> -Doug
>>> 
>> 
> 
>