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https://github.com/golang/go
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53 lines
865 B
Go
53 lines
865 B
Go
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// run
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// Copyright 2019 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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// Issue 30977: write barrier call clobbers volatile
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// value when there are multiple uses of the value.
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package main
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import "runtime"
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type T struct {
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a, b, c, d, e string
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}
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//go:noinline
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func g() T {
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return T{"a", "b", "c", "d", "e"}
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}
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//go:noinline
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func f() {
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// The compiler optimizes this to direct copying
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// the call result to both globals, with write
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// barriers. The first write barrier call clobbers
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// the result of g on stack.
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X = g()
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Y = X
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}
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var X, Y T
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const N = 1000
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func main() {
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// Keep GC running so the write barrier is on.
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go func() {
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for {
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runtime.GC()
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}
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}()
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for i := 0; i < N; i++ {
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runtime.Gosched()
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f()
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if X != Y {
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panic("FAIL")
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}
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}
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}
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