• Kyle Consalus's avatar
    runtime: special case copy, equal for one-word interface values · 4d903504
    Kyle Consalus authored
    Based on the observation that a great number of the types that
    are copied or compared in interfaces, maps, and channels are
    word-sized, this uses specialized copy and equality functions
    for them that use a word instead of 4 or 8 bytes. Seems to yield
    0-6% improvements in performance in the benchmarks I've run.
    For example, with the regexp benchmarks:
    
    Before:
    regexp.BenchmarkLiteral   500000       3.26 µs/op
    regexp.BenchmarkNotLiteral    100000      13.67 µs/op
    regexp.BenchmarkMatchClass    100000      18.72 µs/op
    regexp.BenchmarkMatchClass_InRange    100000      20.04 µs/op
    regexp.BenchmarkReplaceAll    100000      27.85 µs/op
    
    After:
    regexp.BenchmarkLiteral   500000       3.11 µs/op
    regexp.BenchmarkNotLiteral    200000      13.29 µs/op
    regexp.BenchmarkMatchClass    100000      17.65 µs/op
    regexp.BenchmarkMatchClass_InRange    100000      18.49 µs/op
    regexp.BenchmarkReplaceAll    100000      26.34 µs/op
    
    R=rsc
    CC=golang-dev
    https://golang.org/cl/1967047
    4d903504
go.h 25.2 KB