diff options
| author | Josh Bleecher Snyder <josharian@gmail.com> | 2018-04-13 15:37:37 -0700 |
|---|---|---|
| committer | Josh Bleecher Snyder <josharian@gmail.com> | 2018-04-13 23:54:05 +0000 |
| commit | 9137edc986629c18760c4633166b29b556e64567 (patch) | |
| tree | 641700909f1c6ad878dff56189439a2e00254c1f /src/cmd/internal/objfile | |
| parent | 983fca55c0c43ef8cc663e3c0770d62032eac495 (diff) | |
| download | go-9137edc986629c18760c4633166b29b556e64567.tar.xz | |
cmd/internal/objfile: reuse tabwriter across symbols when disassembling
Since the tabwriter is flushed at every symbol,
it can be re-used with no impact on the output.
This cuts allocated space when objdump-ing
the compiler by almost 40%,
and enables further upcoming improvements.
It also speeds up objdump.
name old time/op new time/op delta
ObjdumpCompile 9.22s ± 3% 8.77s ± 3% -4.79% (p=0.000 n=10+9)
Change-Id: Ief114d6c2680a4e762b5f439d3ca8dc7a89b9b27
Reviewed-on: https://go-review.googlesource.com/106978
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Diffstat (limited to 'src/cmd/internal/objfile')
| -rw-r--r-- | src/cmd/internal/objfile/disasm.go | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/cmd/internal/objfile/disasm.go b/src/cmd/internal/objfile/disasm.go index 40f87e4869..deba727695 100644 --- a/src/cmd/internal/objfile/disasm.go +++ b/src/cmd/internal/objfile/disasm.go @@ -197,6 +197,7 @@ func (d *Disasm) Print(w io.Writer, filter *regexp.Regexp, start, end uint64, pr fc = NewFileCache(8) } + tw := tabwriter.NewWriter(bw, 18, 8, 1, '\t', tabwriter.StripEscape) for _, sym := range d.syms { symStart := sym.Addr symEnd := sym.Addr + uint64(sym.Size) @@ -215,7 +216,6 @@ func (d *Disasm) Print(w io.Writer, filter *regexp.Regexp, start, end uint64, pr file, _, _ := d.pcln.PCToLine(sym.Addr) fmt.Fprintf(bw, "TEXT %s(SB) %s\n", sym.Name, file) - tw := tabwriter.NewWriter(bw, 18, 8, 1, '\t', tabwriter.StripEscape) if symEnd > end { symEnd = end } |