1 /* PR optimization/10392
2  * Reporter: marcus@mc.pp.se
3  * Summary: [3.3/3.4 regression] [SH] optimizer generates faulty array indexing
4  * Description:
5  * The address calculation of an index operation on an array on the stack
6  * can _under some conditions_ get messed up completely
7  *
8  * Testcase tweaked by dank@kegel.com
9  * Problem only happens with -O2 -m4, so it should only happen on sh4,
10  * but what the heck, let's test other architectures, too.
11  * Not marked as xfail since it's a regression.
12 */
13 /* { dg-do run } */
14 /* { dg-options "-O2" } */
15 /* { dg-options "-O2 -m4" { target sh4-*-* } } */
16 extern void abort (void);
17 const char *dont_optimize_function_away;
18 
use(const char * str)19 const char *use(const char *str)
20 {
21 	dont_optimize_function_away = str;
22 	if (str[0] != 'v')
23 		abort();
24 	if (str[1] < '1' || str[1] > '6')
25 		abort();
26 	if (str[2])
27 		abort();
28 	return str[2] ? "notused" : "v6";
29 }
30 
func(char * a,char * b)31 const char *func(char *a, char *b)
32 {
33 	char buf[128];
34 	unsigned char i;
35 	const char *result;
36 
37 	char *item[] = {
38 		"v1",
39 		"v2",
40 	};
41 
42 	buf[0] = 'v';
43 	buf[1] = '3';
44 	buf[2] = 0;
45 
46 	for (i = 0; i < 2; i++) {
47 		/* bug is: following line passes wild pointer to use() on sh4 -O2 */
48 		result = use(item[i]);
49 
50 		use(buf);
51 		use(a);
52 		use(b);
53 		result = use(result);
54 	}
55 	return result;
56 }
57 
main()58 int main()
59 {
60 	func("v4", "v5");
61 	return 0;
62 }
63 
64