CL 170738 used mmap for writing most of the output file content.
This change implements similar functionality for Windows.
The output of
compilebench -count=5
command before and after this change
name old time/op new time/op delta
Template 254ms ±14% 239ms ±10% ~ (p=0.222 n=5+5)
Unicode 119ms ±14% 113ms ±12% ~ (p=0.421 n=5+5)
GoTypes 892ms ±23% 850ms ± 1% ~ (p=0.841 n=5+5)
Compiler 3.86s ± 2% 3.82s ± 1% ~ (p=0.222 n=5+5)
SSA 12.6s ± 1% 12.6s ± 1% ~ (p=0.095 n=5+5)
Flate 162ms ±18% 149ms ± 1% -7.91% (p=0.016 n=5+5)
GoParser 199ms ±12% 184ms ± 1% ~ (p=0.056 n=5+5)
Reflect 524ms ±13% 507ms ± 3% ~ (p=0.421 n=5+5)
Tar 207ms ± 7% 198ms ± 0% -4.58% (p=0.016 n=5+4)
XML 305ms ± 6% 299ms ± 5% ~ (p=0.690 n=5+5)
LinkCompiler 1.14s ±11% 1.14s ± 3% ~ (p=0.222 n=5+5)
ExternalLinkCompiler 2.80s ± 5% 2.92s ±13% ~ (p=0.222 n=5+5)
LinkWithoutDebugCompiler 727ms ± 2% 750ms ± 7% ~ (p=0.151 n=5+5)
StdCmd 44.0s ± 8% 43.3s ± 2% ~ (p=1.000 n=5+5)
name old user-time/op new user-time/op delta
Template 300ms ±27% 259ms ±34% ~ (p=0.341 n=5+5)
Unicode 134ms ±51% 144ms ±67% ~ (p=0.548 n=5+5)
GoTypes 1.05s ±10% 1.03s ± 6% ~ (p=0.968 n=5+5)
Compiler 5.01s ± 3% 4.88s ± 3% ~ (p=0.286 n=5+5)
SSA 16.8s ± 1% 16.7s ± 1% -0.95% (p=0.008 n=5+5)
Flate 178ms ±67% 181ms ±38% ~ (p=0.849 n=5+5)
GoParser 231ms ±32% 219ms ±21% ~ (p=0.810 n=5+5)
Reflect 634ms ±33% 650ms ± 6% ~ (p=0.135 n=5+5)
Tar 219ms ±36% 231ms ±19% ~ (p=0.905 n=5+5)
XML 378ms ±20% 366ms ±23% ~ (p=0.913 n=5+5)
LinkCompiler 1.34s ±15% 1.32s ±10% ~ (p=0.730 n=5+5)
ExternalLinkCompiler 1.22s ±13% 1.18s ±15% ~ (p=0.873 n=5+5)
LinkWithoutDebugCompiler 847ms ±13% 841ms ±21% ~ (p=0.667 n=5+5)
name old text-bytes new text-bytes delta
HelloSize 767kB ± 0% 767kB ± 0% ~ (all equal)
CmdGoSize 10.6MB ± 0% 10.6MB ± 0% ~ (all equal)
name old data-bytes new data-bytes delta
HelloSize 10.1kB ± 0% 10.1kB ± 0% ~ (all equal)
CmdGoSize 310kB ± 0% 310kB ± 0% ~ (all equal)
name old bss-bytes new bss-bytes delta
HelloSize 0.00B 0.00B ~ (all equal)
CmdGoSize 0.00B 0.00B ~ (all equal)
name old exe-bytes new exe-bytes delta
HelloSize 1.10MB ± 0% 1.10MB ± 0% ~ (all equal)
CmdGoSize 14.7MB ± 0% 14.7MB ± 0% ~ (all equal)
Change-Id: I653f63213b9cc8a4b05f71938e34b5d53b05e3f5
Reviewed-on: https://go-review.googlesource.com/c/go/+/196846
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
-// +build !darwin,!dragonfly,!freebsd,!linux,!openbsd
+// +build !darwin,!dragonfly,!freebsd,!linux,!openbsd,!windows
package ld
--- /dev/null
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ld
+
+import (
+ "reflect"
+ "syscall"
+ "unsafe"
+)
+
+func (out *OutBuf) Mmap(filesize uint64) error {
+ err := out.f.Truncate(int64(filesize))
+ if err != nil {
+ Exitf("resize output file failed: %v", err)
+ }
+
+ low, high := uint32(filesize), uint32(filesize>>32)
+ fmap, err := syscall.CreateFileMapping(syscall.Handle(out.f.Fd()), nil, syscall.PAGE_READONLY, high, low, nil)
+ if err != nil {
+ return err
+ }
+ defer syscall.CloseHandle(fmap)
+
+ ptr, err := syscall.MapViewOfFile(fmap, syscall.FILE_MAP_READ|syscall.FILE_MAP_WRITE, 0, 0, uintptr(filesize))
+ if err != nil {
+ return err
+ }
+ *(*reflect.SliceHeader)(unsafe.Pointer(&out.buf)) = reflect.SliceHeader{Data: ptr, Len: int(filesize), Cap: int(filesize)}
+ return nil
+}
+
+func (out *OutBuf) Munmap() {
+ if out.buf == nil {
+ return
+ }
+ err := syscall.UnmapViewOfFile(uintptr(unsafe.Pointer(&out.buf[0])))
+ if err != nil {
+ Exitf("UnmapViewOfFile failed: %v", err)
+ }
+}
+
+func (out *OutBuf) Msync() error {
+ // does nothing on windows
+ return nil
+}