Rewrite of IBM doublebyte charsets

[Ulf Zibis]

Am 22.05.2009 01:41, Ulf Zibis schrieb:
> Am 21.05.2009 00:22, Xueming Shen schrieb:
>>
>> Ulf Zibis wrote:
>>
>>> (7) Avoid copying b2cStr to b2c:
>>>    (String#charAt() is fast as char[] access)
>>>   Benefit[7]: increase startup performance for decoder
>>>
>> I tried again last night. char[][] is much faster than the String[] 
>> version in both client
>> and server vm. So keep it asis. (this was actually I switched from 
>> String[] to char[][])
>
> I'm surprised, because I had in mind from older benchmarks, that 
> char_array[index] had same speed than str.charAt(index) after 
> optimization from hotspot.
> I also had this results here: 
> https://java-nio-charset-enhanced.dev.java.net/source/browse/java-nio-charset-enhanced/branches/array_io_string/src/sun/nio/cs/SingleByteFastDecoder.java?rev=&view=markup 
>
>

Maybe hotspot doesn't optimize here, because initC2B() only runs once, 
but later in de/encoder loops .... wouldn't str.charAt(index) be 
optimized by hotspot to same speed?

-Ulf