Codereview request for 7096080: UTF8 update and new CESU-8 charset

[Xueming Shen]

On 10/11/2011 04:36 AM, Ulf Zibis wrote:
> Am 30.09.2011 22:46, schrieb Xueming Shen:
>>
>> I believe we changed from (b1 < xyz) to (b1 >> x) == -2 back to 
>> 2009(?) because
>> the benchmark shows the "shift" version is slightly faster. Do you 
>> have any number
>> shows any difference now. My non-scientific benchmark still suggests 
>> the "shift"
>> type is faster on -server vm, no significant difference on -client vm.
>>
> In this sense, then you should do the same here:
>   87         private static boolean isNotContinuation(int b) {
>   88             return (b >> 6) != -2;
>   89         }

I don't know which one is better, I did a run on

     private static boolean op1(int b) {
         return (b >> 6) != -2;
     }
     private static boolean op2(int b) {
         return (b & 0xc0) != 0x80;
     }
     private static boolean op3(byte b) {
          return b >= (byte)0xc0;
     }

with 1000000 iteration on my linux machine,  and got the scores

op1=1149
op2=1147
op3=1146

I would interpret it as they are identical.

>
>
> Additionally:
> Make private:
>   75     private static final void updatePositions(
>   76             Buffer src, int sp, Buffer dst, int dp) {
>
updated accordingly

-Sherman