RFR(XS): 7902477: JMH perfasm fails with lastest JDK 13

[Nick Gasson]

Hi Aleksey,

>>
>>    Pattern.compile("^(\\S.*)( +)\\[(.+), (.+)[\\]\\[](.*)");
> 
> Can you show the example output where the original regexp fails? Because I think you are adding
> another capture group here, which means the matcher indices at L850-751 below should be amended:

It's failing on this output, where the format changed in JDK 13 to add 
the extra "-------"s.

- - - [BEGIN] - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
- - - -
StubRoutines::updateBytesCRC32 [0x0000ffff6c819700, 0x0000ffff6c819870] 
(368 bytes)
--------------------------------------------------------------------------------
   0x0000ffff6c819700:   stp     x29, x30, [sp, #-16]!
   0x0000ffff6c819704:   mov     x29, sp
   0x0000ffff6c819708:   mvn     w0, w0
   0x0000ffff6c81970c:   subs    x2, x2, #0x80

This parsing code is supposed to match the "StubRountines::..." line, 
which it does, but it also matches the first line of the assembly output.

Unless I'm missing something the patch doesn't add an additional capture 
group. It changes the previous initial capture group (.+) to (\\S.*) and 
anchors it to the start of the line. Because otherwise it will match 
like this:

(  0x0000ffff6c819700:   stp     x29, x30,)( )[(sp), (#-16)](!)

The exception then comes from trying to parse "sp" as a hex address.

Thanks,
Nick