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6129f37367
No point in calling a function when we can build the interface
using a known type (or itab) and the address of a local.
Get rid of third arg (preallocated stack space) to convT2{I,E}.
Makes go binary smaller by 0.2%
benchmark old ns/op new ns/op delta
BenchmarkEfaceInteger-8 16.7 10.1 -39.52%
Update #17118
Update #15375
Change-Id: I9724a1f802bfa1e3957bf1856b55558278e198a2
Reviewed-on: https://go-review.googlesource.com/29373
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
50 lines
1.2 KiB
Go
50 lines
1.2 KiB
Go
// Copyright 2016 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package gc
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import "testing"
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type T struct {
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x [2]int64 // field that will be clobbered. Also makes type not SSAable.
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p *byte // has a pointer
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}
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//go:noinline
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func makeT() T {
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return T{}
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}
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var g T
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var sink interface{}
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func TestIssue15854(t *testing.T) {
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for i := 0; i < 10000; i++ {
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if g.x[0] != 0 {
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t.Fatalf("g.x[0] clobbered with %x\n", g.x[0])
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}
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// The bug was in the following assignment. The return
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// value of makeT() is not copied out of the args area of
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// stack frame in a timely fashion. So when write barriers
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// are enabled, the marshaling of the args for the write
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// barrier call clobbers the result of makeT() before it is
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// read by the write barrier code.
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g = makeT()
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sink = make([]byte, 1000) // force write barriers to eventually happen
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}
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}
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func TestIssue15854b(t *testing.T) {
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const N = 10000
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a := make([]T, N)
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for i := 0; i < N; i++ {
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a = append(a, makeT())
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sink = make([]byte, 1000) // force write barriers to eventually happen
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}
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for i, v := range a {
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if v.x[0] != 0 {
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t.Fatalf("a[%d].x[0] clobbered with %x\n", i, v.x[0])
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}
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}
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}
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