issue43570.go

     1  // run
     2  
     3  // Copyright 2021 The Go Authors. All rights reserved.
     4  // Use of this source code is governed by a BSD-style
     5  // license that can be found in the LICENSE file.
     6  
     7  package main
     8  
     9  import "fmt"
    10  
    11  type T [8]*int
    12  
    13  //go:noinline
    14  func f(x int) T {
    15  	return T{}
    16  }
    17  
    18  //go:noinline
    19  func g(x int, t T) {
    20  	if t != (T{}) {
    21  		panic(fmt.Sprintf("bad: %v", t))
    22  	}
    23  }
    24  
    25  func main() {
    26  	const N = 10000
    27  	var q T
    28  	func() {
    29  		for i := 0; i < N; i++ {
    30  			q = f(0)
    31  			g(0, q)
    32  			sink = make([]byte, 1024)
    33  		}
    34  	}()
    35  	// Note that the closure is a trick to get the write to q to be a
    36  	// write to a pointer that is known to be non-nil and requires
    37  	// a write barrier.
    38  }
    39  
    40  var sink []byte
    41
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