[16] RFR (S) 8249749: modify a primitive array through a stream and a for cycle causes jre crash

[Doerr, Martin]

Hi Vladimir,

thank you for taking care of it. It's good to know that 11u is also affected.

Best regards,
Martin


> -----Original Message-----
> From: Vladimir Kozlov <vladimir.kozlov at oracle.com>
> Sent: Mittwoch, 19. August 2020 00:10
> To: Doerr, Martin <martin.doerr at sap.com>; hotspot compiler <hotspot-
> compiler-dev at openjdk.java.net>
> Cc: Zeller, Arno <arno.zeller at sap.com>
> Subject: Re: [16] RFR (S) 8249749: modify a primitive array through a stream
> and a for cycle causes jre crash
> 
> https://bugs.openjdk.java.net/browse/JDK-8251994
> 
> On 8/18/20 3:03 PM, Vladimir Kozlov wrote:
> > I reproduced it with -XX:UseAVX=0.
> >
> > I will file bug and take care of it.
> >
> > Thanks,
> > Vladimir K
> >
> > On 8/18/20 2:57 PM, Vladimir Kozlov wrote:
> >> Thank you for reporting, Martin
> >>
> >> Please, file bug and specify JDK version, VM flags and CPUID features on
> machine where it fail.
> >>
> >> We test on x86 and aarch64 and I did not see any issues so far.
> >>
> >> Regards,
> >> Vladimir
> >>
> >> On 8/18/20 2:25 PM, Doerr, Martin wrote:
> >>> Hi Vladimir,
> >>>
> >>> we are hitting the following assertion after this change was pushed:
> >>> assert(my_pack(s) == __null) failed: only in one pack
> >>>
> >>> Stack:
> >>>
> V  [jvm.dll+0xbbac55]  SuperWord::construct_my_pack_map+0x135  (superw
> ord.cpp:1723)
> >>>
> V  [jvm.dll+0xbb57f7]  SuperWord::SLP_extract+0x427  (superword.cpp:520)
> >>>
> V  [jvm.dll+0xbcba0b]  SuperWord::transform_loop+0x48b  (superword.cpp:
> 170)
> >>>
> V  [jvm.dll+0x895a09]  PhaseIdealLoop::build_and_optimize+0xef9  (loopnod
> e.cpp:3270)
> >>> V  [jvm.dll+0x3df4b6]  Compile::Optimize+0xf76  (compile.cpp:2187)
> >>> ...
> >>>
> >>> Seems to be reproducible by JTREG test
> compiler/vectorization/TestComplexAddrExpr.java on some x64 and aarch64
> machines.
> >>> (May depend on CPU model.)
> >>>
> >>> Is this a known issue?
> >>> Or should I open a bug?
> >>>
> >>> Best regards,
> >>> Martin
> >>>
> >>>
> >>>> -----Original Message-----
> >>>> From: hotspot-compiler-dev <hotspot-compiler-dev-
> >>>> retn at openjdk.java.net> On Behalf Of Vladimir Kozlov
> >>>> Sent: Montag, 10. August 2020 19:03
> >>>> To: hotspot compiler <hotspot-compiler-dev at openjdk.java.net>
> >>>> Subject: Re: [16] RFR (S) 8249749: modify a primitive array through a
> stream
> >>>> and a for cycle causes jre crash
> >>>>
> >>>> Thank you, Vladimir
> >>>>
> >>>> Vladimir K
> >>>>
> >>>> On 8/10/20 2:04 AM, Vladimir Ivanov wrote:
> >>>>>
> >>>>>> http://cr.openjdk.java.net/~kvn/8249749/webrev.00/
> >>>>>
> >>>>> Looks good.
> >>>>>
> >>>>> Best regards,
> >>>>> Vladimir Ivanov
> >>>>>
> >>>>>> https://bugs.openjdk.java.net/browse/JDK-8249749
> >>>>>>
> >>>>>> SuperWord does not recognize array indexing pattern used in the
> test
> >>>> due to additional AddI node:
> >>>>>>
> >>>>>> AddI(AddI(Invariant(j*n), Loop_phi(i)), Loop_inc(1))
> >>>>>>
> >>>>>> As result it can't find memory reference to align vectors. But code
> ignores
> >>>> that and continue execution.
> >>>>>> Later when align_to_ref is referenced we hit SEGV because it is
> NULL.
> >>>>>>
> >>>>>> The fix is to check align_to_ref for NULL early and bailout.
> >>>>>>
> >>>>>> I also adjusted code in SWPointer::scaled_iv_plus_offset() to
> recognize
> >>>> this address pattern to vectorize test's code.
> >>>>>> And added missing _invar setting.
> >>>>>>
> >>>>>> And I slightly modified tracking code to investigate this issue.
> >>>>>>
> >>>>>> Added new test to check some complex address expressions similar
> to
> >>>> bug's test case. Not all cases in test are
> >>>>>> vectorized - there are other conditions which prevent that.
> >>>>>>
> >>>>>> Tested tier1,tier2,hs-tier3,precheckin-comp
> >>>>>>
> >>>>>> Thanks,
> >>>>>> Vladimir K