unicode: performance improvements (API change)
*** There is an API change here: the introduction of the
LatinOffset int in the RangeTable struct. ***
* Avoid checking Latin range multiple times for non-Latin runes.
* Use linear search when it is faster than binary search.
go test -calibrate runs the calibration for where the linear/binary
crossover should be.
benchmark old MB/s new MB/s speedup
BenchmarkFields 36.27 41.43 1.14x
BenchmarkFieldsFunc 36.23 41.38 1.14x
The speedup here is evenly split between the linear scans
and the LatinOffset change. Both are about 1.07x.
R=r
CC=bradfitz, gobot, golang-dev
https://golang.org/cl/
6526048