• Rob Pike's avatar
    fmt: speed up 10-20% · 53bc1944
    Rob Pike authored
    The check for Stringer etc. can only fire if the test is not a builtin, so avoid
    the expensive check if we know there's no chance.
    Also put in a fast path for pad, which saves a more modest amount.
    
    benchmark                      old ns/op    new ns/op    delta
    BenchmarkSprintfEmpty                148          152   +2.70%
    BenchmarkSprintfString               585          497  -15.04%
    BenchmarkSprintfInt                  441          396  -10.20%
    BenchmarkSprintfIntInt               718          603  -16.02%
    BenchmarkSprintfPrefixedInt          676          621   -8.14%
    BenchmarkSprintfFloat               1003          953   -4.99%
    BenchmarkManyArgs                   2945         2312  -21.49%
    BenchmarkScanInts                1704152      1734441   +1.78%
    BenchmarkScanRecursiveInt        1837397      1828920   -0.46%
    
    R=golang-dev, bradfitz
    CC=golang-dev
    https://golang.org/cl/6245068
    53bc1944
fmt_test.go 22.3 KB