RFC (S) 8076758: new StringBuilder().append(String).toString() should be recognized by OptimizeStringConcat
tobias.hartmann at oracle.com
Mon Aug 31 05:24:51 UTC 2015
I don't think you need the has_offset_field() check because the String.offset field was removed long time ago. We're going to remove the legacy VM side code with the compact strings JEP .
Otherwise it looks good. Please also execute the following test  from compact strings because it contains some string concat correctness checks.
On 28.08.2015 12:12, Aleksey Shipilev wrote:
> I would like to see this one fixed, because it touches on pending String
> improvements in JDK:
> Here is a proof-of-concept patch:
> It passes JPRT and fixes the performance issues in microbenchmarks, but
> I'm not sure the code change is completely correct, given the history of
> OptimizeStringConcat bugs. Could anyone from a compiler team chime in?
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