1// compile
2
3// Copyright 2017 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// Make sure assembly offsets don't get too large.
8
9// To trigger issue21655, the index offset needs to be small
10// enough to fit into an int32 (to get rewritten to an ADDQconst)
11// but large enough to overflow an int32 after multiplying by the stride.
12
13package main
14
15func f1(a []int64, i int64) int64 {
16	return a[i+1<<30]
17}
18func f2(a []int32, i int64) int32 {
19	return a[i+1<<30]
20}
21func f3(a []int16, i int64) int16 {
22	return a[i+1<<30]
23}
24func f4(a []int8, i int64) int8 {
25	return a[i+1<<31]
26}
27func f5(a []float64, i int64) float64 {
28	return a[i+1<<30]
29}
30func f6(a []float32, i int64) float32 {
31	return a[i+1<<30]
32}
33
34// Note: Before the fix for issue 21655, f{1,2,5,6} made
35// the compiler crash. f3 silently generated the wrong
36// code, using an offset of -1<<31 instead of 1<<31.
37// (This is due to the assembler accepting offsets
38// like 0x80000000 and silently using them as
39// signed 32 bit offsets.)
40// f4 was ok, but testing it can't hurt.
41
42func f7(ss []*string, i int) string {
43	const offset = 3 << 29 // 3<<29 * 4 = 3<<31 = 1<<31 mod 1<<32.
44	if i > offset {
45		return *ss[i-offset]
46	}
47	return ""
48}
49func f8(ss []*string, i int) string {
50	const offset = 3<<29 + 10
51	if i > offset {
52		return *ss[i-offset]
53	}
54	return ""
55}
56func f9(ss []*string, i int) string {
57	const offset = 3<<29 - 10
58	if i > offset {
59		return *ss[i-offset]
60	}
61	return ""
62}
63