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// Copyright 2022 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 p
import (
"fmt"
"runtime"
)
var y int
//go:noinline
func Square(x int) {
var pc0, pc1 [1]uintptr
runtime.Callers(1, pc0[:]) // get PC at entry
// a switch using jump table
switch x {
case 1:
y = 1
case 2:
y = 4
case 3:
y = 9
case 4:
y = 16
case 5:
y = 25
case 6:
y = 36
case 7:
y = 49
case 8:
y = 64
default:
panic("too large")
}
// check PC is in the same function
runtime.Callers(1, pc1[:])
if pc1[0] < pc0[0] || pc1[0] > pc0[0]+1000000 {
fmt.Printf("jump across DSO boundary. pc0=%x, pc1=%x\n", pc0[0], pc1[0])
panic("FAIL")
}
if y != x*x {
fmt.Printf("x=%d y=%d!=%d\n", x, y, x*x)
panic("FAIL")
}
}
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