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.
My new guess for the reason: The unfolding of the bytes to int to serve the isNotContinuation / isMalformedxx methods. So those methods should be coded in byte logic too.
But there remains the big question, why c1 is faster than c2, except for 1b. -Ulf
------------------ your new switch--------------- (1) -server Method Millis Ratio Decoding 1b UTF-8 : 125 1.000 Decoding 2b UTF-8 : 2558 20.443 Decoding 3b UTF-8 : 3439 27.481 Decoding 4b UTF-8 : 2030 16.221 (2) -client Decoding 1b UTF-8 : 335 1.000 Decoding 2b UTF-8 : 1041 3.105 Decoding 3b UTF-8 : 2245 6.694 Decoding 4b UTF-8 : 1254 3.741 ------------------ existing "shift"--------------- (1) -server Decoding 1b UTF-8 : 134 1.000 Decoding 2b UTF-8 : 1891 14.106 Decoding 3b UTF-8 : 2934 21.886 Decoding 4b UTF-8 : 2133 15.913 (2) -client Decoding 1b UTF-8 : 341 1.000 Decoding 2b UTF-8 : 949 2.560 Decoding 3b UTF-8 : 2321 6.255 Decoding 4b UTF-8 : 1278 3.446 -sherman
