RFR: 8196331: Optimize Character.digit for latin1 input (original) (raw)

Claes Redestad claes.redestad at oracle.com
Mon Jan 29 11:15:38 UTC 2018


Hi,

for the latin1 block of CharacterData we can improve the digit(int, int) implementation by providing an optimized lookup table. This improves microbenchmarks exercising Integer.parseInt, Long.parseLong and UUID.fromString etc by around 50%for typical inputs.

Webrev: http://cr.openjdk.java.net/~redestad/8196331/open.00/ Bug: https://bugs.openjdk.java.net/browse/JDK-8196331

The lookup array is pre-calculated to minimize startup impact (adds 1,027 bytecodes executed during initialization)

/Claes



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