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/* ET-trees data structure implementation.
   Contributed by Pavel Nejedly
   Copyright (C) 2002, 2003, 2004, 2005, 2007 Free Software Foundation, Inc.
 
This file is part of the libiberty library.
Libiberty is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
 
Libiberty is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Library General Public License for more details.
 
You should have received a copy of the GNU Library General Public
License along with libiberty; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.
 
  The ET-forest structure is described in:
    D. D. Sleator and R. E. Tarjan. A data structure for dynamic trees.
    J.  G'omput. System Sci., 26(3):362 381, 1983.
*/
 
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "et-forest.h"
#include "alloc-pool.h"
 
/* We do not enable this with ENABLE_CHECKING, since it is awfully slow.  */
#undef DEBUG_ET
 
#ifdef DEBUG_ET
#include "basic-block.h"
#endif
 
/* The occurrence of a node in the et tree.  */
struct et_occ
{
  struct et_node *of;           /* The node.  */
 
  struct et_occ *parent;        /* Parent in the splay-tree.  */
  struct et_occ *prev;          /* Left son in the splay-tree.  */
  struct et_occ *next;          /* Right son in the splay-tree.  */
 
  int depth;                    /* The depth of the node is the sum of depth
                                   fields on the path to the root.  */
  int min;                      /* The minimum value of the depth in the subtree
                                   is obtained by adding sum of depth fields
                                   on the path to the root.  */
  struct et_occ *min_occ;       /* The occurrence in the subtree with the minimal
                                   depth.  */
};
 
static alloc_pool et_nodes;
static alloc_pool et_occurrences;
 
/* Changes depth of OCC to D.  */
 
static inline void
set_depth (struct et_occ *occ, int d)
{
  if (!occ)
    return;
 
  occ->min += d - occ->depth;
  occ->depth = d;
}
 
/* Adds D to the depth of OCC.  */
 
static inline void
set_depth_add (struct et_occ *occ, int d)
{
  if (!occ)
    return;
 
  occ->min += d;
  occ->depth += d;
}
 
/* Sets prev field of OCC to P.  */
 
static inline void
set_prev (struct et_occ *occ, struct et_occ *t)
{
#ifdef DEBUG_ET
  gcc_assert (occ != t);
#endif
 
  occ->prev = t;
  if (t)
    t->parent = occ;
}
 
/* Sets next field of OCC to P.  */
 
static inline void
set_next (struct et_occ *occ, struct et_occ *t)
{
#ifdef DEBUG_ET
  gcc_assert (occ != t);
#endif
 
  occ->next = t;
  if (t)
    t->parent = occ;
}
 
/* Recompute minimum for occurrence OCC.  */
 
static inline void
et_recomp_min (struct et_occ *occ)
{
  struct et_occ *mson = occ->prev;
 
  if (!mson
      || (occ->next
          && mson->min > occ->next->min))
      mson = occ->next;
 
  if (mson && mson->min < 0)
    {
      occ->min = mson->min + occ->depth;
      occ->min_occ = mson->min_occ;
    }
  else
    {
      occ->min = occ->depth;
      occ->min_occ = occ;
    }
}
 
#ifdef DEBUG_ET
/* Checks whether neighborhood of OCC seems sane.  */
 
static void
et_check_occ_sanity (struct et_occ *occ)
{
  if (!occ)
    return;
 
  gcc_assert (occ->parent != occ);
  gcc_assert (occ->prev != occ);
  gcc_assert (occ->next != occ);
  gcc_assert (!occ->next || occ->next != occ->prev);
 
  if (occ->next)
    {
      gcc_assert (occ->next != occ->parent);
      gcc_assert (occ->next->parent == occ);
    }
 
  if (occ->prev)
    {
      gcc_assert (occ->prev != occ->parent);
      gcc_assert (occ->prev->parent == occ);
    }
 
  gcc_assert (!occ->parent
              || occ->parent->prev == occ
              || occ->parent->next == occ);
}
 
/* Checks whether tree rooted at OCC is sane.  */
 
static void
et_check_sanity (struct et_occ *occ)
{
  et_check_occ_sanity (occ);
  if (occ->prev)
    et_check_sanity (occ->prev);
  if (occ->next)
    et_check_sanity (occ->next);
}
 
/* Checks whether tree containing OCC is sane.  */
 
static void
et_check_tree_sanity (struct et_occ *occ)
{
  while (occ->parent)
    occ = occ->parent;
 
  et_check_sanity (occ);
}
 
/* For recording the paths.  */
 
/* An ad-hoc constant; if the function has more blocks, this won't work,
   but since it is used for debugging only, it does not matter.  */
#define MAX_NODES 100000
 
static int len;
static void *datas[MAX_NODES];
static int depths[MAX_NODES];
 
/* Records the path represented by OCC, with depth incremented by DEPTH.  */
 
static int
record_path_before_1 (struct et_occ *occ, int depth)
{
  int mn, m;
 
  depth += occ->depth;
  mn = depth;
 
  if (occ->prev)
    {
      m = record_path_before_1 (occ->prev, depth);
      if (m < mn)
        mn = m;
    }
 
  fprintf (stderr, "%d (%d); ", ((basic_block) occ->of->data)->index, depth);
 
  gcc_assert (len < MAX_NODES);
 
  depths[len] = depth;
  datas[len] = occ->of;
  len++;
 
  if (occ->next)
    {
      m = record_path_before_1 (occ->next, depth);
      if (m < mn)
        mn = m;
    }
 
  gcc_assert (mn == occ->min + depth - occ->depth);
 
  return mn;
}
 
/* Records the path represented by a tree containing OCC.  */
 
static void
record_path_before (struct et_occ *occ)
{
  while (occ->parent)
    occ = occ->parent;
 
  len = 0;
  record_path_before_1 (occ, 0);
  fprintf (stderr, "\n");
}
 
/* Checks whether the path represented by OCC, with depth incremented by DEPTH,
   was not changed since the last recording.  */
 
static int
check_path_after_1 (struct et_occ *occ, int depth)
{
  int mn, m;
 
  depth += occ->depth;
  mn = depth;
 
  if (occ->next)
    {
      m = check_path_after_1 (occ->next, depth);
      if (m < mn)
        mn =  m;
    }
 
  len--;
  gcc_assert (depths[len] == depth && datas[len] == occ->of);
 
  if (occ->prev)
    {
      m = check_path_after_1 (occ->prev, depth);
      if (m < mn)
        mn =  m;
    }
 
  gcc_assert (mn == occ->min + depth - occ->depth);
 
  return mn;
}
 
/* Checks whether the path represented by a tree containing OCC was
   not changed since the last recording.  */
 
static void
check_path_after (struct et_occ *occ)
{
  while (occ->parent)
    occ = occ->parent;
 
  check_path_after_1 (occ, 0);
  gcc_assert (!len);
}
 
#endif
 
/* Splay the occurrence OCC to the root of the tree.  */
 
static void
et_splay (struct et_occ *occ)
{
  struct et_occ *f, *gf, *ggf;
  int occ_depth, f_depth, gf_depth;
 
#ifdef DEBUG_ET
  record_path_before (occ);
  et_check_tree_sanity (occ);
#endif
 
  while (occ->parent)
    {
      occ_depth = occ->depth;
 
      f = occ->parent;
      f_depth = f->depth;
 
      gf = f->parent;
 
      if (!gf)
        {
          set_depth_add (occ, f_depth);
          occ->min_occ = f->min_occ;
          occ->min = f->min;
 
          if (f->prev == occ)
            {
              /* zig */
              set_prev (f, occ->next);
              set_next (occ, f);
              set_depth_add (f->prev, occ_depth);
            }
          else
            {
              /* zag */
              set_next (f, occ->prev);
              set_prev (occ, f);
              set_depth_add (f->next, occ_depth);
            }
          set_depth (f, -occ_depth);
          occ->parent = NULL;
 
          et_recomp_min (f);
#ifdef DEBUG_ET
          et_check_tree_sanity (occ);
          check_path_after (occ);
#endif
          return;
        }
 
      gf_depth = gf->depth;
 
      set_depth_add (occ, f_depth + gf_depth);
      occ->min_occ = gf->min_occ;
      occ->min = gf->min;
 
      ggf = gf->parent;
 
      if (gf->prev == f)
        {
          if (f->prev == occ)
            {
              /* zig zig */
              set_prev (gf, f->next);
              set_prev (f, occ->next);
              set_next (occ, f);
              set_next (f, gf);
 
              set_depth (f, -occ_depth);
              set_depth_add (f->prev, occ_depth);
              set_depth (gf, -f_depth);
              set_depth_add (gf->prev, f_depth);
            }
          else
            {
              /* zag zig */
              set_prev (gf, occ->next);
              set_next (f, occ->prev);
              set_prev (occ, f);
              set_next (occ, gf);
 
              set_depth (f, -occ_depth);
              set_depth_add (f->next, occ_depth);
              set_depth (gf, -occ_depth - f_depth);
              set_depth_add (gf->prev, occ_depth + f_depth);
            }
        }
      else
        {
          if (f->prev == occ)
            {
              /* zig zag */
              set_next (gf, occ->prev);
              set_prev (f, occ->next);
              set_prev (occ, gf);
              set_next (occ, f);
 
              set_depth (f, -occ_depth);
              set_depth_add (f->prev, occ_depth);
              set_depth (gf, -occ_depth - f_depth);
              set_depth_add (gf->next, occ_depth + f_depth);
            }
          else
            {
              /* zag zag */
              set_next (gf, f->prev);
              set_next (f, occ->prev);
              set_prev (occ, f);
              set_prev (f, gf);
 
              set_depth (f, -occ_depth);
              set_depth_add (f->next, occ_depth);
              set_depth (gf, -f_depth);
              set_depth_add (gf->next, f_depth);
            }
        }
 
      occ->parent = ggf;
      if (ggf)
        {
          if (ggf->prev == gf)
            ggf->prev = occ;
          else
            ggf->next = occ;
        }
 
      et_recomp_min (gf);
      et_recomp_min (f);
#ifdef DEBUG_ET
      et_check_tree_sanity (occ);
#endif
    }
 
#ifdef DEBUG_ET
  et_check_sanity (occ);
  check_path_after (occ);
#endif
}
 
/* Create a new et tree occurrence of NODE.  */
 
static struct et_occ *
et_new_occ (struct et_node *node)
{
  struct et_occ *nw;
 
  if (!et_occurrences)
    et_occurrences = create_alloc_pool ("et_occ pool", sizeof (struct et_occ), 300);
  nw = pool_alloc (et_occurrences);
 
  nw->of = node;
  nw->parent = NULL;
  nw->prev = NULL;
  nw->next = NULL;
 
  nw->depth = 0;
  nw->min_occ = nw;
  nw->min = 0;
 
  return nw;
}
 
/* Create a new et tree containing DATA.  */
 
struct et_node *
et_new_tree (void *data)
{
  struct et_node *nw;
 
  if (!et_nodes)
    et_nodes = create_alloc_pool ("et_node pool", sizeof (struct et_node), 300);
  nw = pool_alloc (et_nodes);
 
  nw->data = data;
  nw->father = NULL;
  nw->left = NULL;
  nw->right = NULL;
  nw->son = NULL;
 
  nw->rightmost_occ = et_new_occ (nw);
  nw->parent_occ = NULL;
 
  return nw;
}
 
/* Releases et tree T.  */
 
void
et_free_tree (struct et_node *t)
{
  while (t->son)
    et_split (t->son);
 
  if (t->father)
    et_split (t);
 
  pool_free (et_occurrences, t->rightmost_occ);
  pool_free (et_nodes, t);
}
 
/* Releases et tree T without maintaining other nodes.  */
 
void
et_free_tree_force (struct et_node *t)
{
  pool_free (et_occurrences, t->rightmost_occ);
  if (t->parent_occ)
    pool_free (et_occurrences, t->parent_occ);
  pool_free (et_nodes, t);
}
 
/* Release the alloc pools, if they are empty.  */
 
void
et_free_pools (void)
{
  free_alloc_pool_if_empty (&et_occurrences);
  free_alloc_pool_if_empty (&et_nodes);
}
 
/* Sets father of et tree T to FATHER.  */
 
void
et_set_father (struct et_node *t, struct et_node *father)
{
  struct et_node *left, *right;
  struct et_occ *rmost, *left_part, *new_f_occ, *p;
 
  /* Update the path represented in the splay tree.  */
  new_f_occ = et_new_occ (father);
 
  rmost = father->rightmost_occ;
  et_splay (rmost);
 
  left_part = rmost->prev;
 
  p = t->rightmost_occ;
  et_splay (p);
 
  set_prev (new_f_occ, left_part);
  set_next (new_f_occ, p);
 
  p->depth++;
  p->min++;
  et_recomp_min (new_f_occ);
 
  set_prev (rmost, new_f_occ);
 
  if (new_f_occ->min + rmost->depth < rmost->min)
    {
      rmost->min = new_f_occ->min + rmost->depth;
      rmost->min_occ = new_f_occ->min_occ;
    }
 
  t->parent_occ = new_f_occ;
 
  /* Update the tree.  */
  t->father = father;
  right = father->son;
  if (right)
    left = right->left;
  else
    left = right = t;
 
  left->right = t;
  right->left = t;
  t->left = left;
  t->right = right;
 
  father->son = t;
 
#ifdef DEBUG_ET
  et_check_tree_sanity (rmost);
  record_path_before (rmost);
#endif
}
 
/* Splits the edge from T to its father.  */
 
void
et_split (struct et_node *t)
{
  struct et_node *father = t->father;
  struct et_occ *r, *l, *rmost, *p_occ;
 
  /* Update the path represented by the splay tree.  */
  rmost = t->rightmost_occ;
  et_splay (rmost);
 
  for (r = rmost->next; r->prev; r = r->prev)
    continue;
  et_splay (r);
 
  r->prev->parent = NULL;
  p_occ = t->parent_occ;
  et_splay (p_occ);
  t->parent_occ = NULL;
 
  l = p_occ->prev;
  p_occ->next->parent = NULL;
 
  set_prev (r, l);
 
  et_recomp_min (r);
 
  et_splay (rmost);
  rmost->depth = 0;
  rmost->min = 0;
 
  pool_free (et_occurrences, p_occ);
 
  /* Update the tree.  */
  if (father->son == t)
    father->son = t->right;
  if (father->son == t)
    father->son = NULL;
  else
    {
      t->left->right = t->right;
      t->right->left = t->left;
    }
  t->left = t->right = NULL;
  t->father = NULL;
 
#ifdef DEBUG_ET
  et_check_tree_sanity (rmost);
  record_path_before (rmost);
 
  et_check_tree_sanity (r);
  record_path_before (r);
#endif
}
 
/* Finds the nearest common ancestor of the nodes N1 and N2.  */
 
struct et_node *
et_nca (struct et_node *n1, struct et_node *n2)
{
  struct et_occ *o1 = n1->rightmost_occ, *o2 = n2->rightmost_occ, *om;
  struct et_occ *l, *r, *ret;
  int mn;
 
  if (n1 == n2)
    return n1;
 
  et_splay (o1);
  l = o1->prev;
  r = o1->next;
  if (l)
    l->parent = NULL;
  if (r)
    r->parent = NULL;
  et_splay (o2);
 
  if (l == o2 || (l && l->parent != NULL))
    {
      ret = o2->next;
 
      set_prev (o1, o2);
      if (r)
        r->parent = o1;
    }
  else
    {
      ret = o2->prev;
 
      set_next (o1, o2);
      if (l)
        l->parent = o1;
    }
 
  if (0 < o2->depth)
    {
      om = o1;
      mn = o1->depth;
    }
  else
    {
      om = o2;
      mn = o2->depth + o1->depth;
    }
 
#ifdef DEBUG_ET
  et_check_tree_sanity (o2);
#endif
 
  if (ret && ret->min + o1->depth + o2->depth < mn)
    return ret->min_occ->of;
  else
    return om->of;
}
 
/* Checks whether the node UP is an ancestor of the node DOWN.  */
 
bool
et_below (struct et_node *down, struct et_node *up)
{
  struct et_occ *u = up->rightmost_occ, *d = down->rightmost_occ;
  struct et_occ *l, *r;
 
  if (up == down)
    return true;
 
  et_splay (u);
  l = u->prev;
  r = u->next;
 
  if (!l)
    return false;
 
  l->parent = NULL;
 
  if (r)
    r->parent = NULL;
 
  et_splay (d);
 
  if (l == d || l->parent != NULL)
    {
      if (r)
        r->parent = u;
      set_prev (u, d);
#ifdef DEBUG_ET
      et_check_tree_sanity (u);
#endif
    }
  else
    {
      l->parent = u;
 
      /* In case O1 and O2 are in two different trees, we must just restore the
         original state.  */
      if (r && r->parent != NULL)
        set_next (u, d);
      else
        set_next (u, r);
 
#ifdef DEBUG_ET
      et_check_tree_sanity (u);
#endif
      return false;
    }
 
  if (0 >= d->depth)
    return false;
 
  return !d->next || d->next->min + d->depth >= 0;
}

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[/] [openrisc/] [trunk/] [gnu-old/] [gcc-4.2.2/] [gcc/] [et-forest.c] - Blame information for rev 38

Line No.	Rev	Author	Line
1	38	julius	`/* ET-trees data structure implementation.`
2			`Contributed by Pavel Nejedly`
3			`Copyright (C) 2002, 2003, 2004, 2005, 2007 Free Software Foundation, Inc.`
4
5			`This file is part of the libiberty library.`
6			`Libiberty is free software; you can redistribute it and/or`
7			`modify it under the terms of the GNU Library General Public`
8			`License as published by the Free Software Foundation; either`
9			`version 3 of the License, or (at your option) any later version.`
10
11			`Libiberty is distributed in the hope that it will be useful,`
12			`but WITHOUT ANY WARRANTY; without even the implied warranty of`
13			`MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU`
14			`Library General Public License for more details.`
15
16			`You should have received a copy of the GNU Library General Public`
17			`License along with libiberty; see the file COPYING3. If not see`
18			`<http://www.gnu.org/licenses/>.`
19
20			`The ET-forest structure is described in:`
21			`D. D. Sleator and R. E. Tarjan. A data structure for dynamic trees.`
22			`J. G'omput. System Sci., 26(3):362 381, 1983.`
23			`*/`
24
25			`#include "config.h"`
26			`#include "system.h"`
27			`#include "coretypes.h"`
28			`#include "tm.h"`
29			`#include "et-forest.h"`
30			`#include "alloc-pool.h"`
31
32			`/* We do not enable this with ENABLE_CHECKING, since it is awfully slow. */`
33			`#undef DEBUG_ET`
34
35			`#ifdef DEBUG_ET`
36			`#include "basic-block.h"`
37			`#endif`
38
39			`/* The occurrence of a node in the et tree. */`
40			`struct et_occ`
41			`{`
42			`struct et_node of; / The node. */`
43
44			`struct et_occ parent; / Parent in the splay-tree. */`
45			`struct et_occ prev; / Left son in the splay-tree. */`
46			`struct et_occ next; / Right son in the splay-tree. */`
47
48			`int depth; /* The depth of the node is the sum of depth`
49			`fields on the path to the root. */`
50			`int min; /* The minimum value of the depth in the subtree`
51			`is obtained by adding sum of depth fields`
52			`on the path to the root. */`
53			`struct et_occ min_occ; / The occurrence in the subtree with the minimal`
54			`depth. */`
55			`};`
56
57			`static alloc_pool et_nodes;`
58			`static alloc_pool et_occurrences;`
59
60			`/* Changes depth of OCC to D. */`
61
62			`static inline void`
63			`set_depth (struct et_occ *occ, int d)`
64			`{`
65			`if (!occ)`
66			`return;`
67
68			`occ->min += d - occ->depth;`
69			`occ->depth = d;`
70			`}`
71
72			`/* Adds D to the depth of OCC. */`
73
74			`static inline void`
75			`set_depth_add (struct et_occ *occ, int d)`
76			`{`
77			`if (!occ)`
78			`return;`
79
80			`occ->min += d;`
81			`occ->depth += d;`
82			`}`
83
84			`/* Sets prev field of OCC to P. */`
85
86			`static inline void`
87			`set_prev (struct et_occ occ, struct et_occ t)`
88			`{`
89			`#ifdef DEBUG_ET`
90			`gcc_assert (occ != t);`
91			`#endif`
92
93			`occ->prev = t;`
94			`if (t)`
95			`t->parent = occ;`
96			`}`
97
98			`/* Sets next field of OCC to P. */`
99
100			`static inline void`
101			`set_next (struct et_occ occ, struct et_occ t)`
102			`{`
103			`#ifdef DEBUG_ET`
104			`gcc_assert (occ != t);`
105			`#endif`
106
107			`occ->next = t;`
108			`if (t)`
109			`t->parent = occ;`
110			`}`
111
112			`/* Recompute minimum for occurrence OCC. */`
113
114			`static inline void`
115			`et_recomp_min (struct et_occ *occ)`
116			`{`
117			`struct et_occ *mson = occ->prev;`
118
119			`if (!mson`
120			`\|\| (occ->next`
121			`&& mson->min > occ->next->min))`
122			`mson = occ->next;`
123
124			`if (mson && mson->min < 0)`
125			`{`
126			`occ->min = mson->min + occ->depth;`
127			`occ->min_occ = mson->min_occ;`
128			`}`
129			`else`
130			`{`
131			`occ->min = occ->depth;`
132			`occ->min_occ = occ;`
133			`}`
134			`}`
135
136			`#ifdef DEBUG_ET`
137			`/* Checks whether neighborhood of OCC seems sane. */`
138
139			`static void`
140			`et_check_occ_sanity (struct et_occ *occ)`
141			`{`
142			`if (!occ)`
143			`return;`
144
145			`gcc_assert (occ->parent != occ);`
146			`gcc_assert (occ->prev != occ);`
147			`gcc_assert (occ->next != occ);`
148			`gcc_assert (!occ->next \|\| occ->next != occ->prev);`
149
150			`if (occ->next)`
151			`{`
152			`gcc_assert (occ->next != occ->parent);`
153			`gcc_assert (occ->next->parent == occ);`
154			`}`
155
156			`if (occ->prev)`
157			`{`
158			`gcc_assert (occ->prev != occ->parent);`
159			`gcc_assert (occ->prev->parent == occ);`
160			`}`
161
162			`gcc_assert (!occ->parent`
163			`\|\| occ->parent->prev == occ`
164			`\|\| occ->parent->next == occ);`
165			`}`
166
167			`/* Checks whether tree rooted at OCC is sane. */`
168
169			`static void`
170			`et_check_sanity (struct et_occ *occ)`
171			`{`
172			`et_check_occ_sanity (occ);`
173			`if (occ->prev)`
174			`et_check_sanity (occ->prev);`
175			`if (occ->next)`
176			`et_check_sanity (occ->next);`
177			`}`
178
179			`/* Checks whether tree containing OCC is sane. */`
180
181			`static void`
182			`et_check_tree_sanity (struct et_occ *occ)`
183			`{`
184			`while (occ->parent)`
185			`occ = occ->parent;`
186
187			`et_check_sanity (occ);`
188			`}`
189
190			`/* For recording the paths. */`
191
192			`/* An ad-hoc constant; if the function has more blocks, this won't work,`
193			`but since it is used for debugging only, it does not matter. */`
194			`#define MAX_NODES 100000`
195
196			`static int len;`
197			`static void *datas[MAX_NODES];`
198			`static int depths[MAX_NODES];`
199
200			`/* Records the path represented by OCC, with depth incremented by DEPTH. */`
201
202			`static int`
203			`record_path_before_1 (struct et_occ *occ, int depth)`
204			`{`
205			`int mn, m;`
206
207			`depth += occ->depth;`
208			`mn = depth;`
209
210			`if (occ->prev)`
211			`{`
212			`m = record_path_before_1 (occ->prev, depth);`
213			`if (m < mn)`
214			`mn = m;`
215			`}`
216
217			`fprintf (stderr, "%d (%d); ", ((basic_block) occ->of->data)->index, depth);`
218
219			`gcc_assert (len < MAX_NODES);`
220
221			`depths[len] = depth;`
222			`datas[len] = occ->of;`
223			`len++;`
224
225			`if (occ->next)`
226			`{`
227			`m = record_path_before_1 (occ->next, depth);`
228			`if (m < mn)`
229			`mn = m;`
230			`}`
231
232			`gcc_assert (mn == occ->min + depth - occ->depth);`
233
234			`return mn;`
235			`}`
236
237			`/* Records the path represented by a tree containing OCC. */`
238
239			`static void`
240			`record_path_before (struct et_occ *occ)`
241			`{`
242			`while (occ->parent)`
243			`occ = occ->parent;`
244
245			`len = 0;`
246			`record_path_before_1 (occ, 0);`
247			`fprintf (stderr, "\n");`
248			`}`
249
250			`/* Checks whether the path represented by OCC, with depth incremented by DEPTH,`
251			`was not changed since the last recording. */`
252
253			`static int`
254			`check_path_after_1 (struct et_occ *occ, int depth)`
255			`{`
256			`int mn, m;`
257
258			`depth += occ->depth;`
259			`mn = depth;`
260
261			`if (occ->next)`
262			`{`
263			`m = check_path_after_1 (occ->next, depth);`
264			`if (m < mn)`
265			`mn = m;`
266			`}`
267
268			`len--;`
269			`gcc_assert (depths[len] == depth && datas[len] == occ->of);`
270
271			`if (occ->prev)`
272			`{`
273			`m = check_path_after_1 (occ->prev, depth);`
274			`if (m < mn)`
275			`mn = m;`
276			`}`
277
278			`gcc_assert (mn == occ->min + depth - occ->depth);`
279
280			`return mn;`
281			`}`
282
283			`/* Checks whether the path represented by a tree containing OCC was`
284			`not changed since the last recording. */`
285
286			`static void`
287			`check_path_after (struct et_occ *occ)`
288			`{`
289			`while (occ->parent)`
290			`occ = occ->parent;`
291
292			`check_path_after_1 (occ, 0);`
293			`gcc_assert (!len);`
294			`}`
295
296			`#endif`
297
298			`/* Splay the occurrence OCC to the root of the tree. */`
299
300			`static void`
301			`et_splay (struct et_occ *occ)`
302			`{`
303			`struct et_occ f, gf, *ggf;`
304			`int occ_depth, f_depth, gf_depth;`
305
306			`#ifdef DEBUG_ET`
307			`record_path_before (occ);`
308			`et_check_tree_sanity (occ);`
309			`#endif`
310
311			`while (occ->parent)`
312			`{`
313			`occ_depth = occ->depth;`
314
315			`f = occ->parent;`
316			`f_depth = f->depth;`
317
318			`gf = f->parent;`
319
320			`if (!gf)`
321			`{`
322			`set_depth_add (occ, f_depth);`
323			`occ->min_occ = f->min_occ;`
324			`occ->min = f->min;`
325
326			`if (f->prev == occ)`
327			`{`
328			`/* zig */`
329			`set_prev (f, occ->next);`
330			`set_next (occ, f);`
331			`set_depth_add (f->prev, occ_depth);`
332			`}`
333			`else`
334			`{`
335			`/* zag */`
336			`set_next (f, occ->prev);`
337			`set_prev (occ, f);`
338			`set_depth_add (f->next, occ_depth);`
339			`}`
340			`set_depth (f, -occ_depth);`
341			`occ->parent = NULL;`
342
343			`et_recomp_min (f);`
344			`#ifdef DEBUG_ET`
345			`et_check_tree_sanity (occ);`
346			`check_path_after (occ);`
347			`#endif`
348			`return;`
349			`}`
350
351			`gf_depth = gf->depth;`
352
353			`set_depth_add (occ, f_depth + gf_depth);`
354			`occ->min_occ = gf->min_occ;`
355			`occ->min = gf->min;`
356
357			`ggf = gf->parent;`
358
359			`if (gf->prev == f)`
360			`{`
361			`if (f->prev == occ)`
362			`{`
363			`/* zig zig */`
364			`set_prev (gf, f->next);`
365			`set_prev (f, occ->next);`
366			`set_next (occ, f);`
367			`set_next (f, gf);`
368
369			`set_depth (f, -occ_depth);`
370			`set_depth_add (f->prev, occ_depth);`
371			`set_depth (gf, -f_depth);`
372			`set_depth_add (gf->prev, f_depth);`
373			`}`
374			`else`
375			`{`
376			`/* zag zig */`
377			`set_prev (gf, occ->next);`
378			`set_next (f, occ->prev);`
379			`set_prev (occ, f);`
380			`set_next (occ, gf);`
381
382			`set_depth (f, -occ_depth);`
383			`set_depth_add (f->next, occ_depth);`
384			`set_depth (gf, -occ_depth - f_depth);`
385			`set_depth_add (gf->prev, occ_depth + f_depth);`
386			`}`
387			`}`
388			`else`
389			`{`
390			`if (f->prev == occ)`
391			`{`
392			`/* zig zag */`
393			`set_next (gf, occ->prev);`
394			`set_prev (f, occ->next);`
395			`set_prev (occ, gf);`
396			`set_next (occ, f);`
397
398			`set_depth (f, -occ_depth);`
399			`set_depth_add (f->prev, occ_depth);`
400			`set_depth (gf, -occ_depth - f_depth);`
401			`set_depth_add (gf->next, occ_depth + f_depth);`
402			`}`
403			`else`
404			`{`
405			`/* zag zag */`
406			`set_next (gf, f->prev);`
407			`set_next (f, occ->prev);`
408			`set_prev (occ, f);`
409			`set_prev (f, gf);`
410
411			`set_depth (f, -occ_depth);`
412			`set_depth_add (f->next, occ_depth);`
413			`set_depth (gf, -f_depth);`
414			`set_depth_add (gf->next, f_depth);`
415			`}`
416			`}`
417
418			`occ->parent = ggf;`
419			`if (ggf)`
420			`{`
421			`if (ggf->prev == gf)`
422			`ggf->prev = occ;`
423			`else`
424			`ggf->next = occ;`
425			`}`
426
427			`et_recomp_min (gf);`
428			`et_recomp_min (f);`
429			`#ifdef DEBUG_ET`
430			`et_check_tree_sanity (occ);`
431			`#endif`
432			`}`
433
434			`#ifdef DEBUG_ET`
435			`et_check_sanity (occ);`
436			`check_path_after (occ);`
437			`#endif`
438			`}`
439
440			`/* Create a new et tree occurrence of NODE. */`
441
442			`static struct et_occ *`
443			`et_new_occ (struct et_node *node)`
444			`{`
445			`struct et_occ *nw;`
446
447			`if (!et_occurrences)`
448			`et_occurrences = create_alloc_pool ("et_occ pool", sizeof (struct et_occ), 300);`
449			`nw = pool_alloc (et_occurrences);`
450
451			`nw->of = node;`
452			`nw->parent = NULL;`
453			`nw->prev = NULL;`
454			`nw->next = NULL;`
455
456			`nw->depth = 0;`
457			`nw->min_occ = nw;`
458			`nw->min = 0;`
459
460			`return nw;`
461			`}`
462
463			`/* Create a new et tree containing DATA. */`
464
465			`struct et_node *`
466			`et_new_tree (void *data)`
467			`{`
468			`struct et_node *nw;`
469
470			`if (!et_nodes)`
471			`et_nodes = create_alloc_pool ("et_node pool", sizeof (struct et_node), 300);`
472			`nw = pool_alloc (et_nodes);`
473
474			`nw->data = data;`
475			`nw->father = NULL;`
476			`nw->left = NULL;`
477			`nw->right = NULL;`
478			`nw->son = NULL;`
479
480			`nw->rightmost_occ = et_new_occ (nw);`
481			`nw->parent_occ = NULL;`
482
483			`return nw;`
484			`}`
485
486			`/* Releases et tree T. */`
487
488			`void`
489			`et_free_tree (struct et_node *t)`
490			`{`
491			`while (t->son)`
492			`et_split (t->son);`
493
494			`if (t->father)`
495			`et_split (t);`
496
497			`pool_free (et_occurrences, t->rightmost_occ);`
498			`pool_free (et_nodes, t);`
499			`}`
500
501			`/* Releases et tree T without maintaining other nodes. */`
502
503			`void`
504			`et_free_tree_force (struct et_node *t)`
505			`{`
506			`pool_free (et_occurrences, t->rightmost_occ);`
507			`if (t->parent_occ)`
508			`pool_free (et_occurrences, t->parent_occ);`
509			`pool_free (et_nodes, t);`
510			`}`
511
512			`/* Release the alloc pools, if they are empty. */`
513
514			`void`
515			`et_free_pools (void)`
516			`{`
517			`free_alloc_pool_if_empty (&et_occurrences);`
518			`free_alloc_pool_if_empty (&et_nodes);`
519			`}`
520
521			`/* Sets father of et tree T to FATHER. */`
522
523			`void`
524			`et_set_father (struct et_node t, struct et_node father)`
525			`{`
526			`struct et_node left, right;`
527			`struct et_occ rmost, left_part, new_f_occ, p;`
528
529			`/* Update the path represented in the splay tree. */`
530			`new_f_occ = et_new_occ (father);`
531
532			`rmost = father->rightmost_occ;`
533			`et_splay (rmost);`
534
535			`left_part = rmost->prev;`
536
537			`p = t->rightmost_occ;`
538			`et_splay (p);`
539
540			`set_prev (new_f_occ, left_part);`
541			`set_next (new_f_occ, p);`
542
543			`p->depth++;`
544			`p->min++;`
545			`et_recomp_min (new_f_occ);`
546
547			`set_prev (rmost, new_f_occ);`
548
549			`if (new_f_occ->min + rmost->depth < rmost->min)`
550			`{`
551			`rmost->min = new_f_occ->min + rmost->depth;`
552			`rmost->min_occ = new_f_occ->min_occ;`
553			`}`
554
555			`t->parent_occ = new_f_occ;`
556
557			`/* Update the tree. */`
558			`t->father = father;`
559			`right = father->son;`
560			`if (right)`
561			`left = right->left;`
562			`else`
563			`left = right = t;`
564
565			`left->right = t;`
566			`right->left = t;`
567			`t->left = left;`
568			`t->right = right;`
569
570			`father->son = t;`
571
572			`#ifdef DEBUG_ET`
573			`et_check_tree_sanity (rmost);`
574			`record_path_before (rmost);`
575			`#endif`
576			`}`
577
578			`/* Splits the edge from T to its father. */`
579
580			`void`
581			`et_split (struct et_node *t)`
582			`{`
583			`struct et_node *father = t->father;`
584			`struct et_occ r, l, rmost, p_occ;`
585
586			`/* Update the path represented by the splay tree. */`
587			`rmost = t->rightmost_occ;`
588			`et_splay (rmost);`
589
590			`for (r = rmost->next; r->prev; r = r->prev)`
591			`continue;`
592			`et_splay (r);`
593
594			`r->prev->parent = NULL;`
595			`p_occ = t->parent_occ;`
596			`et_splay (p_occ);`
597			`t->parent_occ = NULL;`
598
599			`l = p_occ->prev;`
600			`p_occ->next->parent = NULL;`
601
602			`set_prev (r, l);`
603
604			`et_recomp_min (r);`
605
606			`et_splay (rmost);`
607			`rmost->depth = 0;`
608			`rmost->min = 0;`
609
610			`pool_free (et_occurrences, p_occ);`
611
612			`/* Update the tree. */`
613			`if (father->son == t)`
614			`father->son = t->right;`
615			`if (father->son == t)`
616			`father->son = NULL;`
617			`else`
618			`{`
619			`t->left->right = t->right;`
620			`t->right->left = t->left;`
621			`}`
622			`t->left = t->right = NULL;`
623			`t->father = NULL;`
624
625			`#ifdef DEBUG_ET`
626			`et_check_tree_sanity (rmost);`
627			`record_path_before (rmost);`
628
629			`et_check_tree_sanity (r);`
630			`record_path_before (r);`
631			`#endif`
632			`}`
633
634			`/* Finds the nearest common ancestor of the nodes N1 and N2. */`
635
636			`struct et_node *`
637			`et_nca (struct et_node n1, struct et_node n2)`
638			`{`
639			`struct et_occ o1 = n1->rightmost_occ, o2 = n2->rightmost_occ, *om;`
640			`struct et_occ l, r, *ret;`
641			`int mn;`
642
643			`if (n1 == n2)`
644			`return n1;`
645
646			`et_splay (o1);`
647			`l = o1->prev;`
648			`r = o1->next;`
649			`if (l)`
650			`l->parent = NULL;`
651			`if (r)`
652			`r->parent = NULL;`
653			`et_splay (o2);`
654
655			`if (l == o2 \|\| (l && l->parent != NULL))`
656			`{`
657			`ret = o2->next;`
658
659			`set_prev (o1, o2);`
660			`if (r)`
661			`r->parent = o1;`
662			`}`
663			`else`
664			`{`
665			`ret = o2->prev;`
666
667			`set_next (o1, o2);`
668			`if (l)`
669			`l->parent = o1;`
670			`}`
671
672			`if (0 < o2->depth)`
673			`{`
674			`om = o1;`
675			`mn = o1->depth;`
676			`}`
677			`else`
678			`{`
679			`om = o2;`
680			`mn = o2->depth + o1->depth;`
681			`}`
682
683			`#ifdef DEBUG_ET`
684			`et_check_tree_sanity (o2);`
685			`#endif`
686
687			`if (ret && ret->min + o1->depth + o2->depth < mn)`
688			`return ret->min_occ->of;`
689			`else`
690			`return om->of;`
691			`}`
692
693			`/* Checks whether the node UP is an ancestor of the node DOWN. */`
694
695			`bool`
696			`et_below (struct et_node down, struct et_node up)`
697			`{`
698			`struct et_occ u = up->rightmost_occ, d = down->rightmost_occ;`
699			`struct et_occ l, r;`
700
701			`if (up == down)`
702			`return true;`
703
704			`et_splay (u);`
705			`l = u->prev;`
706			`r = u->next;`
707
708			`if (!l)`
709			`return false;`
710
711			`l->parent = NULL;`
712
713			`if (r)`
714			`r->parent = NULL;`
715
716			`et_splay (d);`
717
718			`if (l == d \|\| l->parent != NULL)`
719			`{`
720			`if (r)`
721			`r->parent = u;`
722			`set_prev (u, d);`
723			`#ifdef DEBUG_ET`
724			`et_check_tree_sanity (u);`
725			`#endif`
726			`}`
727			`else`
728			`{`
729			`l->parent = u;`
730
731			`/* In case O1 and O2 are in two different trees, we must just restore the`
732			`original state. */`
733			`if (r && r->parent != NULL)`
734			`set_next (u, d);`
735			`else`
736			`set_next (u, r);`
737
738			`#ifdef DEBUG_ET`
739			`et_check_tree_sanity (u);`
740			`#endif`
741			`return false;`
742			`}`
743
744			`if (0 >= d->depth)`
745			`return false;`
746
747			`return !d->next \|\| d->next->min + d->depth >= 0;`
748			`}`