RFR: 8219860: Cleanup ClassFileParser::parse_linenumber_table

[Lois Foltan]

+1, looks good Claes!
Lois

On 3/8/2019 5:34 AM, Robbin Ehn wrote:
> Hi Claes.
>
> Removes 4 times more than it adds, great!
> It seems very reasonably.
>
> Very minor nit, I would remove TRAPS from get_u1(TRAPS) if it's not 
> needed, and I can't see that it is. Keep it if you think it makes some 
> sense.
>
> Thanks, Robbin
>
> On 2019-03-08 10:18, Claes Redestad wrote:
>> Hi,
>>
>> ClassFileParser::parse_linenumber_table use
>> CompressedLineNumberWriteStream to turn line number information into a
>> compact table for inclusion in each Method. Calls in that area are
>> poorly inlined and shows up in startup profiles.
>>
>> Additionally, there are a few hacks in the area to disable compiler
>> optimizations on Windows due a bug in MSC 2005 that caused stack
>> overflow at build time. Testing show no sign of issues, so I suggest
>> removing these explicit deoptimizations.
>>
>> Webrev: http://cr.openjdk.java.net/~redestad/8219860/open.00/
>> Bug:    https://bugs.openjdk.java.net/browse/JDK-8219860
>>
>> Testing: tier1-3, verified a 10-15% reduction of instructions in
>> parse_linenumber_table.
>>
>> Thanks!
>>
>> /Claes