8250825: C2 crashes with assert(field != __null) failed: missing field(Internet mail)

[jiefu(傅杰)]

Thanks Vladimir and Tobias for your review.

Pushed.


Best regards,

Jie


________________________________
From: Vladimir Kozlov <vladimir.kozlov at oracle.com>
Sent: Saturday, August 1, 2020 7:54 AM
To: jiefu(傅杰)
Cc: hotspot compiler
Subject: Re: 8250825: C2 crashes with assert(field != __null) failed: missing field(Internet mail)

Yes, it is good.

Thanks,
Vladimir

On 7/31/20 4:43 PM, jiefu(傅杰) wrote:
> Hi Vladimir K,
>
> The latest version for the test case is here: http://cr.openjdk.java.net/~jiefu/8250825/webrev.02/
> Compared with webrev.01, the changes are:
>       - Rename the test to TestMisalignedUnsafeAccess.java
>       - Add @summary tag
>       - Remove Xbatch
>       - Remvoe initUnsafe
>
> Are you still OK with it?
>
> Thanks.
> Best regards,
> Jie
>
> On 2020/8/1, 12:46 AM, "Vladimir Kozlov" <vladimir.kozlov at oracle.com> wrote:
>
>      Good.
>
>      thanks,
>      Vladimir K
>
>      On 7/30/20 10:06 PM, jiefu(傅杰) wrote:
>      > Hi Vladimir K,
>      >
>      > Thanks for your review.
>      >
>      > The test had been extended here:
>      >    - http://cr.openjdk.java.net/~jiefu/8250825/webrev.01/
>      >
>      > Before the patch:
>      >    The unsafe access (put/get) to static field will crash.
>      >    The unsafe access (put/get) to instance field is fine.
>      >
>      > After the patch:
>      >    All is ok.
>      >
>      > Thanks a lot.
>      > Best regards,
>      > Jie
>      >
>      > On 2020/7/31, 2:24 AM, "hotspot-compiler-dev on behalf of Vladimir Kozlov" <hotspot-compiler-dev-retn at openjdk.java.net on behalf of vladimir.kozlov at oracle.com> wrote:
>      >
>      >      Hi Jie
>      >
>      >      Nodes generated by make_unsafe_address() are correct. The issue is that Unsafe API allows to genereate unaligned (to
>      >      fields) offset with arbitrary type. As result C2 type system can't find corresponding field.
>      >
>      >      Did you tried to do unaligned unsafe access to instance fields?
>      >      Also try to unsafe set value (Store node). There is code in C2 which checks for narrow stores. Would be interesting how
>      >      it behave in unsafe case.
>      >
>      >      Please, extend your test.
>      >
>      >      Otherwise fix is good.
>      >
>      >      Thanks,
>      >      Vladimir K
>      >
>      >      On 7/30/20 6:09 AM, jiefu(傅杰) wrote:
>      >      > Hi all,
>      >      >
>      >      > JBS:    https://bugs.openjdk.java.net/browse/JDK-8250825
>      >      > Webrev: http://cr.openjdk.java.net/~jiefu/8250825/webrev.00/
>      >      >
>      >      > When C2 tries to inline an unsafe-access method, it may generate the following pattern in make_unsafe_address:
>      >      >        ConP  ConL
>      >      >           \  |
>      >      >            \ |
>      >      >            AddP
>      >      > Current implementation of TypeOopPtr::TypeOopPtr(...) failed to recognize it as an unsafe operation, which leads to the crash.
>      >      >
>      >      > Testing:
>      >      >    - tier1-3 on Linux/x64
>      >      >
>      >      > Could you please review it and give me some advice?
>      >      >
>      >      > Thanks a lot.
>      >      > Best regards,
>      >      > Jie
>      >      >
>      >
>      >
>      >
>
>
>