Potential Graal Regression: The location argument could not be resolved to a constant.

[Stefan Marr]

Hi:

Adopting the latest version of Graal, I am having trouble with failing optimization passes because of “The location argument could not be resolved to a constant.”

For all case I investigated so far, I get a stack trace like the following:

	at com.oracle.graal.truffle.FrameWithoutBoxing.getObjectUnsafe(FrameWithoutBoxing.java:84)
	at com.oracle.graal.truffle.FrameWithoutBoxing.getObject(FrameWithoutBoxing.java:68)
	at com.oracle.truffle.api.frame.FrameUtil.getObjectSafe(FrameUtil.java:38)
	at som.interpreter.nodes.literals.BlockNode$BlockNodeWithContext.getOuterSelf(BlockNode.java:67)
	at som.vmobjects.SBlock.getOuterSelf(SBlock.java:103)
	at som.interpreter.nodes.ContextualNode.determineContext(ContextualNode.java:61)

Now, the location in question, i.e., the frame slot, is used like this [1]:

    public Object getOuterSelf(final MaterializedFrame frame) {
      return FrameUtil.getObjectSafe(frame, outerSelfSlot);
    }

And defined as `private final FrameSlot outerSelfSlot;`

This reminds me of a change I did in March [2] based on Andreas’ comment [3].
But, now this problem seems to be back, and since I didn’t change anything in my code, but just updated Graal, it looks like there might be either a regression or an old problem exposed.
However, I don’t really see how I could get the frame slot ‘even more constant’ than what I have now.
Perhaps, I am reading the stack trace wrong, or there is something else going on?



To reproduce, the following should give an up-to-date TruffleSOM (note the recursive git submodule checkout, core-lib probably needs an update if you got an older copy):

git clone --recursive https://github.com/SOM-st/TruffleSOM.git
ant jar
ant test
./graal.sh -cp Smalltalk Examples/Benchmarks/BenchmarkHarness.som TreeSort 100 0 100

Thanks
Stefan

[1] https://github.com/SOM-st/TruffleSOM/blob/master/src/som/interpreter/nodes/literals/BlockNode.java#L67
[2] https://github.com/SOM-st/TruffleSOM/commit/c002b9be8bbed2ecf0c7a3fce93f9c108563e73e
[3] http://markmail.org/message/ad7jd2ewopheqo2l


-- 
Stefan Marr
INRIA Lille - Nord Europe
http://stefan-marr.de/research/