Hi Alan,
I gave the "continue ->else if " a try, it appears the server vm
obviously likes
the "continue" approach (it is consistent with what we experienced in
the past
when we did similar approach for ascii, in which we separate/singled the
ascii
path out). So I guess we probably want to keep the continue here.
Here are the data. dbcs2_new is to replace the continue with else if and the
dbcs2 is the "continue".
http://cr.openjdk.java.net/~sherman/7183053/dbcs2_new
http://cr.openjdk.java.net/~sherman/7183053/dbcs2
-Sherman
On 07/13/2012 10:09 AM, Xueming Shen wrote:
In JDK7, the decoder and encoder implementation of most of our
single-byte charsets
and UTF-8 charset are optimized to implement the internal interfce
sun.nio.cs.ArrayDecoder/
Encoder to provide a fastpath for String.getBytes(...) and new
String(byte[]...) operations. I
have an old blog regarding this optimization at
https://blogs.oracle.com/xuemingshen/entry/faster_new_string_bytes_cs
This rfe, as the followup for above changes, is to implement
ArrayDe/Encoder for most
of the sun.nio.cs.ext.DoubleByte based double-byte charsets. Here is
the webrev
http://cr.openjdk.java.net/~sherman/7183053/webrev
I've taken a pass over this and it's great to see
DoubleByte.Decoder/Encoder implementing
sun.nio.cs.ArrayDecoder/Encoder. The results looks good too, a small
number of regressions (Big5 at len=32 for example) but this is a
micro benchmark and I'm sure there are fluctuations. I don't see
anything obviously wrong with the EBCDIC changes I'd need a history
book to remember how the shifts between DBCS and SBCS. I think our
tests our good for this area so I'm happy. One minor nit is the
continue in both encode methods, I think it would be cleaner to use
"else if (bb ..." instead.
The continue might make the vm happy, but this is the code I did last
Oct, so I might be
wrong. Will give a couple run later with "else"
