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// run
// Copyright 2021 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.
// This testcase caused a crash when the register ABI was in effect,
// on amd64 (problem with register allocation).
package main
type Op struct {
tag string
_x []string
_q [20]uint64
plist []P
}
type P struct {
tag string
_x [10]uint64
b bool
}
type M int
//go:noinline
func (w *M) walkP(p *P) *P {
np := &P{}
*np = *p
np.tag += "new"
return np
}
func (w *M) walkOp(op *Op) *Op {
if op == nil {
return nil
}
orig := op
cloned := false
clone := func() {
if !cloned {
cloned = true
op = &Op{}
*op = *orig
}
}
pCloned := false
for i := range op.plist {
if s := w.walkP(&op.plist[i]); s != &op.plist[i] {
if !pCloned {
pCloned = true
clone()
op.plist = make([]P, len(orig.plist))
copy(op.plist, orig.plist)
}
op.plist[i] = *s
}
}
return op
}
func main() {
var ww M
w := &ww
p1 := P{tag: "a"}
p1._x[1] = 9
o := Op{tag: "old", plist: []P{p1}}
no := w.walkOp(&o)
if no.plist[0].tag != "anew" {
panic("bad")
}
}
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