• Josh Bleecher Snyder's avatar
    encoding/binary: use an offset instead of slicing · b8543397
    Josh Bleecher Snyder authored
    While running make.bash, over 5% of all pointer writes
    come from encoding/binary doing struct reads.
    
    This change replaces slicing during such reads with an offset.
    This avoids updating the slice pointer with every
    struct field read or write.
    
    This has no impact when the write barrier is off.
    Running the benchmarks with GOGC=1, however,
    shows significant improvement:
    
    name          old time/op    new time/op    delta
    ReadStruct-8    13.2µs ± 6%    10.1µs ± 5%  -23.24%  (p=0.000 n=10+10)
    
    name          old speed      new speed      delta
    ReadStruct-8  5.69MB/s ± 6%  7.40MB/s ± 5%  +30.18%  (p=0.000 n=10+10)
    
    Change-Id: I22904263196bfeddc38abe8989428e263aee5253
    Reviewed-on: https://go-review.googlesource.com/98757
    Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
    TryBot-Result: Gobot Gobot <gobot@golang.org>
    Reviewed-by: 's avatarIan Lance Taylor <iant@golang.org>
    b8543397
binary.go 16.7 KB