112 lines
2.0 KiB
C
112 lines
2.0 KiB
C
/* { dg-do run } */
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/* { dg-options "-std=gnu99 -Wall -Wextra -O1" } */
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extern void *memset (void*, int, __SIZE_TYPE__);
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extern void abort (void);
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struct radix_tree_root {
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unsigned int height;
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struct radix_tree_node *rnode;
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};
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struct radix_tree_node {
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unsigned int count;
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void *slots[64];
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unsigned long tags[2][2];
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};
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struct radix_tree_path {
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struct radix_tree_node *node, **slot;
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int offset;
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};
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static unsigned long height_to_maxindex[7] =
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{0, 63, 4095, 262143, 16777215, 1073741823, 4294967295};
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static inline void tag_clear(struct radix_tree_node *node, int tag, int offset)
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{
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int nr;
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volatile unsigned long *addr;
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#if(__SIZEOF_INT__ >= 4)
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int mask;
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#else
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long mask;
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#endif
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nr = offset;
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addr = &node->tags[tag][0];
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addr += nr >> 5;
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mask = 1 << (nr & 0x1f);
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*addr &= ~mask;
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}
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void *radix_tree_tag_clear(struct radix_tree_root *root, unsigned long index, int tag)
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{
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struct radix_tree_path path[7], *pathp = path;
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unsigned int height, shift;
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void *ret = 0;
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height = root->height;
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if (index > height_to_maxindex[height])
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goto out;
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shift = (height - 1) * 6;
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pathp->node = 0;
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pathp->slot = &root->rnode;
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while (height > 0) {
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int offset;
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if (*pathp->slot == 0)
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goto out;
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offset = (index >> shift) & (64-1);
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pathp[1].offset = offset;
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pathp[1].node = *pathp[0].slot;
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pathp[1].slot = (struct radix_tree_node **)
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(pathp[1].node->slots + offset);
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pathp++;
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shift -= 6;
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height--;
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}
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ret = *pathp[0].slot;
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if (ret == 0)
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goto out;
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do {
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int idx;
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tag_clear(pathp[0].node, tag, pathp[0].offset);
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for (idx = 0; idx < 2; idx++) {
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if (pathp[0].node->tags[tag][idx])
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goto out;
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}
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pathp--;
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} while (pathp[0].node);
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out:
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return ret;
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}
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int main ()
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{
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struct radix_tree_root r;
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struct radix_tree_node node;
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void *p = (void *) 0xdeadbeef;
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r.height = 1;
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r.rnode = &node;
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memset (&node, 0, sizeof (node));
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node.count = 1;
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node.slots [13] = p;
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radix_tree_tag_clear (&r, 13, 1);
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if (r.rnode->slots[13] != p)
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abort ();
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return 0;
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}
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