1 /* { dg-do run } */
2 /* { dg-options "-std=gnu99 -Wall -Wextra -O1" } */
3
4 extern void *memset (void*, int, __SIZE_TYPE__);
5 extern void abort (void);
6
7 struct radix_tree_root {
8 unsigned int height;
9 struct radix_tree_node *rnode;
10 };
11
12 struct radix_tree_node {
13 unsigned int count;
14 void *slots[64];
15 unsigned long tags[2][2];
16 };
17
18 struct radix_tree_path {
19 struct radix_tree_node *node, **slot;
20 int offset;
21 };
22
23 static unsigned long height_to_maxindex[7] =
24 {0, 63, 4095, 262143, 16777215, 1073741823, 4294967295};
25
tag_clear(struct radix_tree_node * node,int tag,int offset)26 static inline void tag_clear(struct radix_tree_node *node, int tag, int offset)
27 {
28 int nr;
29 volatile unsigned long *addr;
30 #if(__SIZEOF_INT__ >= 4)
31 int mask;
32 #else
33 long mask;
34 #endif
35
36 nr = offset;
37 addr = &node->tags[tag][0];
38
39 addr += nr >> 5;
40 mask = 1 << (nr & 0x1f);
41 *addr &= ~mask;
42 }
43
radix_tree_tag_clear(struct radix_tree_root * root,unsigned long index,int tag)44 void *radix_tree_tag_clear(struct radix_tree_root *root, unsigned long index, int tag)
45 {
46 struct radix_tree_path path[7], *pathp = path;
47 unsigned int height, shift;
48 void *ret = 0;
49
50 height = root->height;
51 if (index > height_to_maxindex[height])
52 goto out;
53
54 shift = (height - 1) * 6;
55 pathp->node = 0;
56 pathp->slot = &root->rnode;
57
58 while (height > 0) {
59 int offset;
60
61 if (*pathp->slot == 0)
62 goto out;
63
64 offset = (index >> shift) & (64-1);
65 pathp[1].offset = offset;
66 pathp[1].node = *pathp[0].slot;
67 pathp[1].slot = (struct radix_tree_node **)
68 (pathp[1].node->slots + offset);
69 pathp++;
70 shift -= 6;
71 height--;
72 }
73
74 ret = *pathp[0].slot;
75 if (ret == 0)
76 goto out;
77
78 do {
79 int idx;
80
81 tag_clear(pathp[0].node, tag, pathp[0].offset);
82 for (idx = 0; idx < 2; idx++) {
83 if (pathp[0].node->tags[tag][idx])
84 goto out;
85 }
86 pathp--;
87 } while (pathp[0].node);
88 out:
89 return ret;
90 }
91
main()92 int main ()
93 {
94 struct radix_tree_root r;
95 struct radix_tree_node node;
96 void *p = (void *) 0xdeadbeef;
97
98 r.height = 1;
99 r.rnode = &node;
100
101 memset (&node, 0, sizeof (node));
102
103 node.count = 1;
104 node.slots [13] = p;
105
106 radix_tree_tag_clear (&r, 13, 1);
107
108 if (r.rnode->slots[13] != p)
109 abort ();
110 return 0;
111 }
112