1// run
2
3// Copyright 2011 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
7package main
8
9// 5g bug used to set up the 0 for -f() before calling f,
10// and the call to f smashed the register.
11
12func f(n int) int {
13	s := 0
14	for i := 0; i < n; i++ {
15		s += i>>1
16	}
17	return s
18}
19
20func main() {
21	x := -f(100)
22	if x != -2450 {
23		println(x)
24		panic("broken")
25	}
26}
27