RFR 8209626: [JVMCI] Use implicit exception table for dispatch and printing

[Vladimir Kozlov]

On 12/12/18 1:06 PM, Tom Rodriguez wrote:
> They all look like preexisting failures to me.  The CheckGraalIntrinsics one you mentioned in chat and 

yes

> compiler/aot/DeoptimizationTest.java which seems to have been failing at least intermittently for a while.  What do you 
> think?

SIGFPE is new. And I think your changes in sharedRuntime.cpp may affected execution of AOT methods because they are 
marked as compiled by Graal (compiler_jvmci):

http://hg.openjdk.java.net/jdk/jdk/file/9e28eff3d40f/src/hotspot/share/aot/aotCompiledMethod.hpp#l131

Vladimir

> 
> It does make me wonder if AOT needs any extra support to use the implicit exception table.  I would assume we'd be 
> seeing problems if that was the case but don't really know.
> 
> tom
> 
> Vladimir Kozlov wrote on 12/12/18 11:12 AM:
>> Tom,
>>
>> Some tests failed.
>>
>> Thanks,
>> Vladimir
>>
>> On 12/12/18 10:42 AM, Tom Rodriguez wrote:
>>> http://cr.openjdk.java.net/~never/8209626/webrev
>>> https://bugs.openjdk.java.net/browse/JDK-8209626
>>>
>>> Graal handles implicit exceptions by deoptimizing and that's currently done in a way that's hard to understand from 
>>> the PrintNMethods output. Basically there's just an extra PcDesc at the implicit check location and the runtime 
>>> assumes that a fault with a PcDesc underneath it an implicit check.  This changes JVMCI to use the implicit exception 
>>> table to mark these locations specially which simplifies the dispatching and 
>>> printing.  The new print output looks like this:
>>>
>>>    0x0000000120f053a0: mov    DWORD PTR [rsp-0x14000],eax
>>>    0x0000000120f053a7: sub    rsp,0x18
>>>    0x0000000120f053ab: mov    QWORD PTR [rsp+0x10],rbp       ;*aload_0 {reexecute=1 rethrow=0 return_oop=0}
>>>                                                              ; - java.lang.StringLatin1::equals at 0 (line 94)
>>>
>>>    0x0000000120f053b0: mov    eax,DWORD PTR [rsi+0xc]        ; implicit exception: deoptimizes
>>>                                                              ; ImmutableOopMap{rdx=Oop rsi=Oop }
>>>                                                              ;*aload_0 {reexecute=1 rethrow=0 return_oop=0}
>>>                                                              ; - java.lang.StringLatin1::equals at 0 (line 94)
>>>
>>>    0x0000000120f053b3: mov    r10d,DWORD PTR [rdx+0xc]       ; implicit exception: deoptimizes
>>>                                                              ; ImmutableOopMap{rdx=Oop rsi=Oop }
>>>
>>> The scope information is still printed in the normal original location. This has been in use with JVMCI 8 for several 
>>> months.
>>>
>>> tom