1 /* Various examples of safe array access for which -Warray-bounds
2 shouldn't issue a warning at any optimization level
3 (PR tree-optimization/83510). */
4
5 /* { dg-options "-Warray-bounds" } */
6
7 /* This test is XFAILed because thread1 threads a switch statement
8 such that the various cases have been split into different
9 independent blocks. One of these blocks exposes an arr[i_27]
10 which is later propagated by VRP to be arr[10]. This is an
11 invalid access, but the array bounds code doesn't know it is an
12 unreachable path.
13
14 However, it is not until dom2 that we "know" that the value of the
15 switch index is such that the path to arr[10] is unreachable. For
16 that matter, it is not until dom3 that we remove the unreachable
17 path.
18
19
20 See:
21 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83510
22 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83312
23
24 It's not until here that ranger "knows" that the path is
25 unreachable:
26
27 thread1
28 vrp1 <-- array bounds checking
29 dce2
30 stdarg
31 cdce
32 cselim
33 copyprop
34 ifcombine
35 mergephi3 <-- too late
36 */
37
38 extern int get_flag (void);
39
40 unsigned int arr[10];
41
42 struct xyz {
43 unsigned int a0;
44 };
45
46 extern void wfm(struct xyz *, int, unsigned int);
47
48 static unsigned int f(struct xyz * ctx, unsigned int number)
49 {
50 switch (number) {
51 case 0x9:
52 return ctx->a0;
53 case 0xA: case 0xB:
54 case 0xC: case 0xD: case 0xE: case 0xF:
55 case 0x10: case 0x11: case 0x12: case 0x13:
56 return arr[number - 0xa];
57 }
58 return 0;
59 }
60
61 int g(struct xyz * ctx) {
62 int i;
63
64 for (i = 0; i < 10; i++) {
65 wfm(ctx, i, f(ctx, i));
66 }
67
68 return 0;
69 }
70
71 int g_signed(struct xyz * ctx) {
72 int i;
73
74 for (i = 0; i < 10; i++) {
75 wfm(ctx, i, f(ctx, i));
76 }
77
78 return 0;
79 }
80
81 void test_2 (struct xyz * ctx)
82 {
83 int i;
84
85 for (i = 0; i < 10; i++) {
86 if (get_flag ())
87 wfm(ctx, i, f(ctx, i));
88 }
89 }
90
91 void test_3 (struct xyz * ctx)
92 {
93 unsigned int i;
94
95 for (i = 0; i < 10; i++) {
96 switch (i) {
97 case 0x9:
98 wfm(ctx, i, ctx->a0);
99 break;
100 case 0xA: case 0xB:
101 case 0xC: case 0xD: case 0xE: case 0xF:
102 case 0x10: case 0x11: case 0x12: case 0x13:
103 if (get_flag ())
104 wfm(ctx, i, arr[i - 0xa]);
105 break;
106 }
107 }
108 }
109
110 void test_3_signed (struct xyz * ctx)
111 {
112 int i;
113
114 for (i = 0; i < 10; i++) {
115 switch (i) {
116 case 0x9:
117 wfm(ctx, i, ctx->a0);
118 break;
119 case 0xA: case 0xB:
120 case 0xC: case 0xD: case 0xE: case 0xF:
121 case 0x10: case 0x11: case 0x12: case 0x13:
122 if (get_flag ())
123 wfm(ctx, i, arr[i]);
124 break;
125 }
126 }
127 }
128
129 void test_4 (struct xyz * ctx)
130 {
131 unsigned int i, j;
132
133 for (i = 0; i < 10; i++) {
134 switch (i) {
135 case 0x9:
136 wfm(ctx, i, ctx->a0);
137 break;
138 case 0xA: case 0xB:
139 case 0xC: case 0xD: case 0xE: case 0xF:
140 case 0x10: case 0x11: case 0x12: case 0x13:
141 for (j = 0; j < 5; j++)
142 wfm(ctx, i, arr[i - 0xa]);
143 break;
144 }
145 }
146 }
147 void test_4_signed (struct xyz * ctx)
148 {
149 int i, j;
150
151 for (i = 0; i < 10; i++) {
152 switch (i) {
153 case 0x9:
154 wfm(ctx, i, ctx->a0);
155 break;
156 case 0xA: case 0xB:
157 case 0xC: case 0xD: case 0xE: case 0xF:
158 case 0x10: case 0x11: case 0x12: case 0x13:
159 for (j = 0; j < 5; j++)
160 wfm(ctx, i, arr[i]);
161 break;
162 }
163 }
164 }
165
166 void test_5 (struct xyz * ctx)
167 {
168 unsigned int i;
169 for (i = 10; i < 20; i++) {
170 wfm(ctx, i, arr[i - 10]);
171 }
172 }
173
174 void test_5_signed (struct xyz * ctx)
175 {
176 int i;
177 for (i = 10; i < 20; i++) {
178 wfm(ctx, i, arr[i - 10]);
179 }
180 }