HSAIL (tests) and inlining issue

[Deneau, Tom]

> -----Original Message-----
> From: Doug Simon [mailto:doug.simon at oracle.com]
> Sent: Tuesday, June 17, 2014 10:45 AM
> To: Deneau, Tom
> Cc: Caspole, Eric; graal-dev at openjdk.java.net
> Subject: Re: HSAIL (tests) and inlining issue
> 
> 
> On Jun 17, 2014, at 5:32 PM, Deneau, Tom <tom.deneau at amd.com> wrote:
> 
> > Doug --
> >
> > I didn't understand the relation between resolving
> StringIndexOutOfBoundsException and inlining String.equals().
> 
> In
> com.oracle.graal.compiler.hsail.test.lambda.NewStringEqualsTest.runTest(
> ) we have the following:
> 
>         dispatchLambdaKernel(NUM, (gid) -> {
>             outArray[gid] = new String(chars, 0, 10 + (gid %
> 3)).equals(base);
>         });
> 
> The String(char[], int, int) constructor called above contains:
> 
>         if (count < 0) {
>             throw new StringIndexOutOfBoundsException(count);
>         }
> 
> When RemoveNeverExecutedCode == false, then the 'then' branch will be
> compiled. If StringIndexOutOfBoundsException is unresolved, the
> allocation of StringIndexOutOfBoundsException is converted to a deopt.
> If it's resolved, then InlineEverything==true ensure it is inlined. This
> constructor (indirectly) recursively calls String(char[], int, int). The
> inliner performs recursive inlining until it hits
> GraalOptions.MaximumDesiredSize which means it never gets to inline
> String.equals.
> 
> > I'm trying to remember why we disabled RemoveNeverExecutedCode.  I
> think it was because our junits often don't run enough times in java
> mode to get valid profiling information so we might need code even if it
> was previously never executed.
> 
> You could make the unit tests run in Java mode in a loop long enough to
> get the desired profile.
>

Agreed. If the profile runs long enough, we can trust it and deopt on the paths that weren't executed and get rid of -G:-RemoveNeverExecutedCode.  And I guess if we do find something deopting we can always try to recompile.

We'll try to plan out some way to deal with this.
 
> > I need to think more about your suggestion of InlineOrDeopt.  While
> this would allow a test to pass functionally, we wouldn't want to
> actually offload a kernel where there was a deoptimization on the main
> compilation path.
> 
> Won't the profile gathered for the kernel prior to compilation be
> accurate in most cases?

Yes as mentioned above, if it runs long enough we should be able to trust it for removing never-executed code, etc.  But what about an actual recursive method in the main path?  We can't inline that, so we would deopt but it would be a poor offload candidate if it de-opted on the main codepath.

> 
> -Doug
> 
> >> -----Original Message-----
> >> From: Doug Simon [mailto:doug.simon at oracle.com]
> >> Sent: Tuesday, June 17, 2014 10:03 AM
> >> To: Caspole, Eric; Deneau, Tom
> >> Cc: graal-dev at openjdk.java.net
> >> Subject: HSAIL (tests) and inlining issue
> >>
> >> Eric, Tom,
> >>
> >> We've had issues on our gate recently caused by intermittent failures
> >> of NewStringEqualsTest (stack trace below). If
> >> StringIndexOutOfBoundsException is resolved before this test is run,
> >> then inlining exhausts its budget before getting to inline
> >> String.equals which in turn leaves a direct call in the graph,
> >> something that HSAIL cannot currently handle. The primary problem is
> >> the use of InlineEverything and RemoveNeverExecutedCode in the HSAIL
> >> tests. As we've seen, these don't actually guarantee everything will
> be inlined.
> >>
> >> For now, I've disabled NewStringEqualsTest and added a comment as to
> >> why. I'm not sure what the longer term solution is. I'd at least like
> >> to see RemoveNeverExecutedCode go away - do we really need it?
> >>
> >> Now that HSAIL supports deopt, maybe we can change InlineEverything
> >> to InlineEverythingOrDeopt - calls that cannot be inlined are replace
> >> with DopetimizeNodes.
> >>
> >> -Doug
> >>
> >>
> >> 2)
> >> testUsingLambdaMethod(com.oracle.graal.compiler.hsail.test.lambda.New
> >> Str
> >> ingEqualsTest)
> >> com.oracle.graal.graph.GraalGraphInternalError:
> >> com.oracle.graal.compiler.common.GraalInternalError: unimplemented:
> >> direct call to java.lang.String.equals(Object)
> >> 	at node: 110|Invoke#Direct#String.equals
> >> 	at
> >> com.oracle.graal.graph.GraalGraphInternalError.transformAndAddContext
> >> (Gr
> >> aalGraphInternalError.java:136)
> >> 	at
> >> com.oracle.graal.compiler.gen.NodeLIRBuilder.doBlock(NodeLIRBuilder.j
> >> ava
> >> :220)
> >> 	at
> >> com.oracle.graal.compiler.GraalCompiler.emitBlock(GraalCompiler.java:
> >> 216
> >> )
> >> 	at
> >>
> com.oracle.graal.compiler.GraalCompiler.emitLIR(GraalCompiler.java:250)
> >> 	at
> >> com.oracle.graal.compiler.GraalCompiler.emitBackEnd(GraalCompiler.jav
> >> a:1
> >> 98)
> >> 	at
> >>
> com.oracle.graal.compiler.GraalCompiler.compileGraph(GraalCompiler.java:
> >> 141)
> >> 	at
> >> com.oracle.graal.hotspot.hsail.HSAILHotSpotBackend.compileKernel(HSAI
> >> LHo
> >> tSpotBackend.java:195)
> >> 	at
> >> com.oracle.graal.hotspot.hsail.HSAILHotSpotBackend.compileAndInstallK
> >> ern
> >> el(HSAILHotSpotBackend.java:153)
> >> 	at
> >> com.oracle.graal.compiler.hsail.test.infra.GraalKernelTester.dispatch
> >> Ker
> >> nelOkra(GraalKernelTester.java:163)
> >> 	at
> >> com.oracle.graal.compiler.hsail.test.infra.KernelTester.dispatchLambd
> >> aMe
> >> thodKernelOkra(KernelTester.java:598)
> >> 	at
> >> com.oracle.graal.compiler.hsail.test.infra.KernelTester.dispatchLambd
> >> aMe
> >> thodKernel(KernelTester.java:279)
> >> 	at
> >> com.oracle.graal.compiler.hsail.test.infra.KernelTester.dispatchLambd
> >> aKe
> >> rnel(KernelTester.java:301)
> >> 	at
> >> com.oracle.graal.compiler.hsail.test.lambda.NewStringEqualsTest.runTe
> >> st(
> >> NewStringEqualsTest.java:55)
> >> 	at
> >> com.oracle.graal.compiler.hsail.test.infra.KernelTester.runOkraInstan
> >> ce(
> >> KernelTester.java:666)
> >> 	at
> >> com.oracle.graal.compiler.hsail.test.infra.KernelTester.assertOkraEqu
> >> als
> >> Seq(KernelTester.java:656)
> >> 	at
> >> com.oracle.graal.compiler.hsail.test.infra.KernelTester.testGenerated
> >> Hsa
> >> ilUsingLambdaMethod(KernelTester.java:683)
> >> 	at
> >> com.oracle.graal.compiler.hsail.test.infra.GraalKernelTester.testGene
> >> rat
> >> edHsailUsingLambdaMethod(GraalKernelTester.java:206)
> >> 	at
> >> com.oracle.graal.compiler.hsail.test.lambda.NewStringEqualsTest.testU
> >> sin
> >> gLambdaMethod(NewStringEqualsTest.java:76)
> >> 	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> >> 	at
> >> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
> >> jav
> >> a:62)
> >> 	at
> >> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
> >> sor
> >> Impl.java:43)
> >> 	at java.lang.reflect.Method.invoke(Method.java:483)
> >> 	at
> >> org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(Framework
> >> Met
> >> hod.java:47)
> >> 	at
> >> org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCal
> >> lab
> >> le.java:12)
> >> 	at
> >> org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMe
> >> tho
> >> d.java:44)
> >> 	at
> >> org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMet
> >> hod
> >> .java:17)
> >> 	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
> >> 	at
> >> org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRun
> >> ner
> >> .java:70)
> >> 	at
> >> org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRun
> >> ner
> >> .java:50)
> >> 	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
> >> 	at
> >> org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
> >> 	at
> >> org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
> >> 	at
> >> org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
> >> 	at
> >> org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
> >> 	at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
> >> 	at org.junit.runners.Suite.runChild(Suite.java:127)
> >> 	at org.junit.runners.Suite.runChild(Suite.java:26)
> >> 	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
> >> 	at
> >> org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
> >> 	at org.junit.runn
> >> ers.ParentRunner.runChildren(ParentRunner.java:236)
> >> 	at
> >> org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
> >> 	at
> >> org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
> >> 	at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
> >> 	at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
> >> 	at org.junit.runner.JUnitCore.run(JUnitCore.java:138)
> >> 	at org.junit.runner.JUnitCore.run(JUnitCore.java:117)
> >> 	at
> >> com.oracle.graal.test.GraalJUnitCore.main(GraalJUnitCore.java:102)
> >> 	at JUnitWrapper.main(JUnitWrapper.java:78)
> >> Caused by: com.oracle.graal.compiler.common.GraalInternalError:
> >> unimplemented: direct call to java.lang.String.equals(Object)
> >> 	at
> >> com.oracle.graal.compiler.common.GraalInternalError.unimplemented(Gra
> >> alI
> >> nternalError.java:40)
> >> 	at
> >> com.oracle.graal.compiler.hsail.HSAILNodeLIRBuilder.emitDirectCall(HS
> >> AIL
> >> NodeLIRBuilder.java:50)
> >> 	at
> >> com.oracle.graal.compiler.gen.NodeLIRBuilder.emitInvoke(NodeLIRBuilde
> >> r.j
> >> ava:472)
> >> 	at
> >> com.oracle.graal.nodes.InvokeNode.generate(InvokeNode.java:131)
> >> 	at
> >> com.oracle.graal.compiler.gen.NodeLIRBuilder.emitNode(NodeLIRBuilder.
> >> jav
> >> a:312)
> >> 	at
> >> com.oracle.graal.hotspot.hsail.HSAILHotSpotNodeLIRBuilder.emitNode(HS
> >> AIL
> >> HotSpotNodeLIRBuilder.java:56)
> >> 	at
> >>
> com.oracle.graal.compiler.gen.NodeLIRBuilder.doRoot(NodeLIRBuilder.java:
> >> 303)
> >> 	at
> >> com.oracle.graal.compiler.gen.NodeLIRBuilder.doBlock(NodeLIRBuilder.j
> >> ava
> >> :218)
> >> 	... 46 more
> >>
> >> FAILURES!!!
> >> Tests run: 4527,  Failures: 2