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| author | Emmanuel T Odeke <emmanuel@orijtech.com> | 2019-09-19 23:35:34 -0700 |
|---|---|---|
| committer | Emmanuel Odeke <emm.odeke@gmail.com> | 2019-09-20 08:55:30 +0000 |
| commit | 0d9981bccb0e9783b25491c9395702ca099a11e3 (patch) | |
| tree | 0091d7daf1f395ecd805216dabfc82c0f9c2df6d /src/debug | |
| parent | bb0a8fd38f4b14f79b0da1cfe3e732f3bfb63a51 (diff) | |
| download | go-0d9981bccb0e9783b25491c9395702ca099a11e3.tar.gz go-0d9981bccb0e9783b25491c9395702ca099a11e3.zip | |
debug/dwarf: optimize buf.string
(*buf).string previously manually searched
through its underlying byte slice until we
encountered a '0'. This change instead uses
bytes.IndexByte that results in a speed up:
$ benchstat before.txt after.txt
name old time/op new time/op delta
BufString-8 257ns ± 1% 174ns ± 1% -32.37% (p=0.000 n=9+8)
name old speed new speed delta
BufString-8 495MB/s ± 1% 732MB/s ± 1% +47.76% (p=0.000 n=10+8)
name old alloc/op new alloc/op delta
BufString-8 162B ± 0% 162B ± 0% ~ (all equal)
name old allocs/op new allocs/op delta
BufString-8 3.00 ± 0% 3.00 ± 0% ~ (all equal)
Change-Id: I7cf241742cc091d5d30d987a168b02d83955b1cf
Reviewed-on: https://go-review.googlesource.com/c/go/+/196657
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Diffstat (limited to 'src/debug')
| -rw-r--r-- | src/debug/dwarf/buf.go | 19 |
1 files changed, 10 insertions, 9 deletions
diff --git a/src/debug/dwarf/buf.go b/src/debug/dwarf/buf.go index 3e6ce293fd..c3822a0dac 100644 --- a/src/debug/dwarf/buf.go +++ b/src/debug/dwarf/buf.go @@ -7,6 +7,7 @@ package dwarf import ( + "bytes" "encoding/binary" "strconv" ) @@ -79,16 +80,16 @@ func (b *buf) bytes(n int) []byte { func (b *buf) skip(n int) { b.bytes(n) } func (b *buf) string() string { - for i := 0; i < len(b.data); i++ { - if b.data[i] == 0 { - s := string(b.data[0:i]) - b.data = b.data[i+1:] - b.off += Offset(i + 1) - return s - } + i := bytes.IndexByte(b.data, 0) + if i < 0 { + b.error("underflow") + return "" } - b.error("underflow") - return "" + + s := string(b.data[0:i]) + b.data = b.data[i+1:] + b.off += Offset(i + 1) + return s } func (b *buf) uint16() uint16 { |