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];
      16  };
      17  
      18  struct radix_tree_path {
      19  	struct radix_tree_node *node, **slot;
      20  	int offset;
      21  };
      22  
      23  void radix_tree_tag_clear(struct radix_tree_root *root, unsigned long index)
      24  {
      25  	struct radix_tree_path path[7], *pathp = path;
      26  	unsigned int height, shift;
      27  	volatile unsigned long *addr;
      28  	
      29  	height = root->height;
      30  	
      31  	shift = (height - 1) * 6;
      32  	path[0].slot = &root->rnode;
      33  	
      34  	while (height > 0) {
      35  		int offset;
      36  		
      37  		offset = (index >> shift) & (64-1);
      38  		pathp[1].offset = offset;
      39  		pathp[1].node = *pathp[0].slot;
      40  		pathp[1].slot = (struct radix_tree_node **)
      41  			(pathp[1].node->slots + offset);
      42  		pathp++;
      43  		shift -= 6;
      44  		height--;
      45  	}
      46  	
      47  	addr = &(pathp->node->tags[0]) + 1;
      48  	*addr = 574;
      49  }
      50  
      51  struct radix_tree_root r;
      52  struct radix_tree_node node;
      53  
      54  int main ()
      55  {
      56    	r.height = 1;
      57  	r.rnode = &node;
      58  	
      59  	memset (&node, 0, sizeof (node));
      60  	
      61  	node.count = 1;
      62  	
      63  	radix_tree_tag_clear (&r, 13);
      64  	return 0;
      65  }