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

[Vladimir Kozlov]

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