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/* ET-trees data structure implementation.
   Contributed by Pavel Nejedly
   Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008 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 = (struct et_occ *) 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 = (struct et_node *) 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;
}
 
/* Returns the root of the tree that contains NODE.  */
 
struct et_node *
et_root (struct et_node *node)
{
  struct et_occ *occ = node->rightmost_occ, *r;
 
  /* The root of the tree corresponds to the rightmost occurrence in the
     represented path.  */
  et_splay (occ);
  for (r = occ; r->next; r = r->next)
    continue;
  et_splay (r);
 
  return r->of;
}

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[/] [openrisc/] [trunk/] [gnu-stable/] [gcc-4.5.1/] [gcc/] [et-forest.c] - Blame information for rev 859

Line No.	Rev	Author	Line
1	280	jeremybenn	`/* ET-trees data structure implementation.`
2			`Contributed by Pavel Nejedly`
3			`Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008 Free Software`
4			`Foundation, Inc.`
5
6			`This file is part of the libiberty library.`
7			`Libiberty is free software; you can redistribute it and/or`
8			`modify it under the terms of the GNU Library General Public`
9			`License as published by the Free Software Foundation; either`
10			`version 3 of the License, or (at your option) any later version.`
11
12			`Libiberty is distributed in the hope that it will be useful,`
13			`but WITHOUT ANY WARRANTY; without even the implied warranty of`
14			`MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU`
15			`Library General Public License for more details.`
16
17			`You should have received a copy of the GNU Library General Public`
18			`License along with libiberty; see the file COPYING3. If not see`
19			`<http://www.gnu.org/licenses/>.`
20
21			`The ET-forest structure is described in:`
22			`D. D. Sleator and R. E. Tarjan. A data structure for dynamic trees.`
23			`J. G'omput. System Sci., 26(3):362 381, 1983.`
24			`*/`
25
26			`#include "config.h"`
27			`#include "system.h"`
28			`#include "coretypes.h"`
29			`#include "tm.h"`
30			`#include "et-forest.h"`
31			`#include "alloc-pool.h"`
32
33			`/* We do not enable this with ENABLE_CHECKING, since it is awfully slow. */`
34			`#undef DEBUG_ET`
35
36			`#ifdef DEBUG_ET`
37			`#include "basic-block.h"`
38			`#endif`
39
40			`/* The occurrence of a node in the et tree. */`
41			`struct et_occ`
42			`{`
43			`struct et_node of; / The node. */`
44
45			`struct et_occ parent; / Parent in the splay-tree. */`
46			`struct et_occ prev; / Left son in the splay-tree. */`
47			`struct et_occ next; / Right son in the splay-tree. */`
48
49			`int depth; /* The depth of the node is the sum of depth`
50			`fields on the path to the root. */`
51			`int min; /* The minimum value of the depth in the subtree`
52			`is obtained by adding sum of depth fields`
53			`on the path to the root. */`
54			`struct et_occ min_occ; / The occurrence in the subtree with the minimal`
55			`depth. */`
56			`};`
57
58			`static alloc_pool et_nodes;`
59			`static alloc_pool et_occurrences;`
60
61			`/* Changes depth of OCC to D. */`
62
63			`static inline void`
64			`set_depth (struct et_occ *occ, int d)`
65			`{`
66			`if (!occ)`
67			`return;`
68
69			`occ->min += d - occ->depth;`
70			`occ->depth = d;`
71			`}`
72
73			`/* Adds D to the depth of OCC. */`
74
75			`static inline void`
76			`set_depth_add (struct et_occ *occ, int d)`
77			`{`
78			`if (!occ)`
79			`return;`
80
81			`occ->min += d;`
82			`occ->depth += d;`
83			`}`
84
85			`/* Sets prev field of OCC to P. */`
86
87			`static inline void`
88			`set_prev (struct et_occ occ, struct et_occ t)`
89			`{`
90			`#ifdef DEBUG_ET`
91			`gcc_assert (occ != t);`
92			`#endif`
93
94			`occ->prev = t;`
95			`if (t)`
96			`t->parent = occ;`
97			`}`
98
99			`/* Sets next field of OCC to P. */`
100
101			`static inline void`
102			`set_next (struct et_occ occ, struct et_occ t)`
103			`{`
104			`#ifdef DEBUG_ET`
105			`gcc_assert (occ != t);`
106			`#endif`
107
108			`occ->next = t;`
109			`if (t)`
110			`t->parent = occ;`
111			`}`
112
113			`/* Recompute minimum for occurrence OCC. */`
114
115			`static inline void`
116			`et_recomp_min (struct et_occ *occ)`
117			`{`
118			`struct et_occ *mson = occ->prev;`
119
120			`if (!mson`
121			`\|\| (occ->next`
122			`&& mson->min > occ->next->min))`
123			`mson = occ->next;`
124
125			`if (mson && mson->min < 0)`
126			`{`
127			`occ->min = mson->min + occ->depth;`
128			`occ->min_occ = mson->min_occ;`
129			`}`
130			`else`
131			`{`
132			`occ->min = occ->depth;`
133			`occ->min_occ = occ;`
134			`}`
135			`}`
136
137			`#ifdef DEBUG_ET`
138			`/* Checks whether neighborhood of OCC seems sane. */`
139
140			`static void`
141			`et_check_occ_sanity (struct et_occ *occ)`
142			`{`
143			`if (!occ)`
144			`return;`
145
146			`gcc_assert (occ->parent != occ);`
147			`gcc_assert (occ->prev != occ);`
148			`gcc_assert (occ->next != occ);`
149			`gcc_assert (!occ->next \|\| occ->next != occ->prev);`
150
151			`if (occ->next)`
152			`{`
153			`gcc_assert (occ->next != occ->parent);`
154			`gcc_assert (occ->next->parent == occ);`
155			`}`
156
157			`if (occ->prev)`
158			`{`
159			`gcc_assert (occ->prev != occ->parent);`
160			`gcc_assert (occ->prev->parent == occ);`
161			`}`
162
163			`gcc_assert (!occ->parent`
164			`\|\| occ->parent->prev == occ`
165			`\|\| occ->parent->next == occ);`
166			`}`
167
168			`/* Checks whether tree rooted at OCC is sane. */`
169
170			`static void`
171			`et_check_sanity (struct et_occ *occ)`
172			`{`
173			`et_check_occ_sanity (occ);`
174			`if (occ->prev)`
175			`et_check_sanity (occ->prev);`
176			`if (occ->next)`
177			`et_check_sanity (occ->next);`
178			`}`
179
180			`/* Checks whether tree containing OCC is sane. */`
181
182			`static void`
183			`et_check_tree_sanity (struct et_occ *occ)`
184			`{`
185			`while (occ->parent)`
186			`occ = occ->parent;`
187
188			`et_check_sanity (occ);`
189			`}`
190
191			`/* For recording the paths. */`
192
193			`/* An ad-hoc constant; if the function has more blocks, this won't work,`
194			`but since it is used for debugging only, it does not matter. */`
195			`#define MAX_NODES 100000`
196
197			`static int len;`
198			`static void *datas[MAX_NODES];`
199			`static int depths[MAX_NODES];`
200
201			`/* Records the path represented by OCC, with depth incremented by DEPTH. */`
202
203			`static int`
204			`record_path_before_1 (struct et_occ *occ, int depth)`
205			`{`
206			`int mn, m;`
207
208			`depth += occ->depth;`
209			`mn = depth;`
210
211			`if (occ->prev)`
212			`{`
213			`m = record_path_before_1 (occ->prev, depth);`
214			`if (m < mn)`
215			`mn = m;`
216			`}`
217
218			`fprintf (stderr, "%d (%d); ", ((basic_block) occ->of->data)->index, depth);`
219
220			`gcc_assert (len < MAX_NODES);`
221
222			`depths[len] = depth;`
223			`datas[len] = occ->of;`
224			`len++;`
225
226			`if (occ->next)`
227			`{`
228			`m = record_path_before_1 (occ->next, depth);`
229			`if (m < mn)`
230			`mn = m;`
231			`}`
232
233			`gcc_assert (mn == occ->min + depth - occ->depth);`
234
235			`return mn;`
236			`}`
237
238			`/* Records the path represented by a tree containing OCC. */`
239
240			`static void`
241			`record_path_before (struct et_occ *occ)`
242			`{`
243			`while (occ->parent)`
244			`occ = occ->parent;`
245
246			`len = 0;`
247			`record_path_before_1 (occ, 0);`
248			`fprintf (stderr, "\n");`
249			`}`
250
251			`/* Checks whether the path represented by OCC, with depth incremented by DEPTH,`
252			`was not changed since the last recording. */`
253
254			`static int`
255			`check_path_after_1 (struct et_occ *occ, int depth)`
256			`{`
257			`int mn, m;`
258
259			`depth += occ->depth;`
260			`mn = depth;`
261
262			`if (occ->next)`
263			`{`
264			`m = check_path_after_1 (occ->next, depth);`
265			`if (m < mn)`
266			`mn = m;`
267			`}`
268
269			`len--;`
270			`gcc_assert (depths[len] == depth && datas[len] == occ->of);`
271
272			`if (occ->prev)`
273			`{`
274			`m = check_path_after_1 (occ->prev, depth);`
275			`if (m < mn)`
276			`mn = m;`
277			`}`
278
279			`gcc_assert (mn == occ->min + depth - occ->depth);`
280
281			`return mn;`
282			`}`
283
284			`/* Checks whether the path represented by a tree containing OCC was`
285			`not changed since the last recording. */`
286
287			`static void`
288			`check_path_after (struct et_occ *occ)`
289			`{`
290			`while (occ->parent)`
291			`occ = occ->parent;`
292
293			`check_path_after_1 (occ, 0);`
294			`gcc_assert (!len);`
295			`}`
296
297			`#endif`
298
299			`/* Splay the occurrence OCC to the root of the tree. */`
300
301			`static void`
302			`et_splay (struct et_occ *occ)`
303			`{`
304			`struct et_occ f, gf, *ggf;`
305			`int occ_depth, f_depth, gf_depth;`
306
307			`#ifdef DEBUG_ET`
308			`record_path_before (occ);`
309			`et_check_tree_sanity (occ);`
310			`#endif`
311
312			`while (occ->parent)`
313			`{`
314			`occ_depth = occ->depth;`
315
316			`f = occ->parent;`
317			`f_depth = f->depth;`
318
319			`gf = f->parent;`
320
321			`if (!gf)`
322			`{`
323			`set_depth_add (occ, f_depth);`
324			`occ->min_occ = f->min_occ;`
325			`occ->min = f->min;`
326
327			`if (f->prev == occ)`
328			`{`
329			`/* zig */`
330			`set_prev (f, occ->next);`
331			`set_next (occ, f);`
332			`set_depth_add (f->prev, occ_depth);`
333			`}`
334			`else`
335			`{`
336			`/* zag */`
337			`set_next (f, occ->prev);`
338			`set_prev (occ, f);`
339			`set_depth_add (f->next, occ_depth);`
340			`}`
341			`set_depth (f, -occ_depth);`
342			`occ->parent = NULL;`
343
344			`et_recomp_min (f);`
345			`#ifdef DEBUG_ET`
346			`et_check_tree_sanity (occ);`
347			`check_path_after (occ);`
348			`#endif`
349			`return;`
350			`}`
351
352			`gf_depth = gf->depth;`
353
354			`set_depth_add (occ, f_depth + gf_depth);`
355			`occ->min_occ = gf->min_occ;`
356			`occ->min = gf->min;`
357
358			`ggf = gf->parent;`
359
360			`if (gf->prev == f)`
361			`{`
362			`if (f->prev == occ)`
363			`{`
364			`/* zig zig */`
365			`set_prev (gf, f->next);`
366			`set_prev (f, occ->next);`
367			`set_next (occ, f);`
368			`set_next (f, gf);`
369
370			`set_depth (f, -occ_depth);`
371			`set_depth_add (f->prev, occ_depth);`
372			`set_depth (gf, -f_depth);`
373			`set_depth_add (gf->prev, f_depth);`
374			`}`
375			`else`
376			`{`
377			`/* zag zig */`
378			`set_prev (gf, occ->next);`
379			`set_next (f, occ->prev);`
380			`set_prev (occ, f);`
381			`set_next (occ, gf);`
382
383			`set_depth (f, -occ_depth);`
384			`set_depth_add (f->next, occ_depth);`
385			`set_depth (gf, -occ_depth - f_depth);`
386			`set_depth_add (gf->prev, occ_depth + f_depth);`
387			`}`
388			`}`
389			`else`
390			`{`
391			`if (f->prev == occ)`
392			`{`
393			`/* zig zag */`
394			`set_next (gf, occ->prev);`
395			`set_prev (f, occ->next);`
396			`set_prev (occ, gf);`
397			`set_next (occ, f);`
398
399			`set_depth (f, -occ_depth);`
400			`set_depth_add (f->prev, occ_depth);`
401			`set_depth (gf, -occ_depth - f_depth);`
402			`set_depth_add (gf->next, occ_depth + f_depth);`
403			`}`
404			`else`
405			`{`
406			`/* zag zag */`
407			`set_next (gf, f->prev);`
408			`set_next (f, occ->prev);`
409			`set_prev (occ, f);`
410			`set_prev (f, gf);`
411
412			`set_depth (f, -occ_depth);`
413			`set_depth_add (f->next, occ_depth);`
414			`set_depth (gf, -f_depth);`
415			`set_depth_add (gf->next, f_depth);`
416			`}`
417			`}`
418
419			`occ->parent = ggf;`
420			`if (ggf)`
421			`{`
422			`if (ggf->prev == gf)`
423			`ggf->prev = occ;`
424			`else`
425			`ggf->next = occ;`
426			`}`
427
428			`et_recomp_min (gf);`
429			`et_recomp_min (f);`
430			`#ifdef DEBUG_ET`
431			`et_check_tree_sanity (occ);`
432			`#endif`
433			`}`
434
435			`#ifdef DEBUG_ET`
436			`et_check_sanity (occ);`
437			`check_path_after (occ);`
438			`#endif`
439			`}`
440
441			`/* Create a new et tree occurrence of NODE. */`
442
443			`static struct et_occ *`
444			`et_new_occ (struct et_node *node)`
445			`{`
446			`struct et_occ *nw;`
447
448			`if (!et_occurrences)`
449			`et_occurrences = create_alloc_pool ("et_occ pool", sizeof (struct et_occ), 300);`
450			`nw = (struct et_occ *) pool_alloc (et_occurrences);`
451
452			`nw->of = node;`
453			`nw->parent = NULL;`
454			`nw->prev = NULL;`
455			`nw->next = NULL;`
456
457			`nw->depth = 0;`
458			`nw->min_occ = nw;`
459			`nw->min = 0;`
460
461			`return nw;`
462			`}`
463
464			`/* Create a new et tree containing DATA. */`
465
466			`struct et_node *`
467			`et_new_tree (void *data)`
468			`{`
469			`struct et_node *nw;`
470
471			`if (!et_nodes)`
472			`et_nodes = create_alloc_pool ("et_node pool", sizeof (struct et_node), 300);`
473			`nw = (struct et_node *) pool_alloc (et_nodes);`
474
475			`nw->data = data;`
476			`nw->father = NULL;`
477			`nw->left = NULL;`
478			`nw->right = NULL;`
479			`nw->son = NULL;`
480
481			`nw->rightmost_occ = et_new_occ (nw);`
482			`nw->parent_occ = NULL;`
483
484			`return nw;`
485			`}`
486
487			`/* Releases et tree T. */`
488
489			`void`
490			`et_free_tree (struct et_node *t)`
491			`{`
492			`while (t->son)`
493			`et_split (t->son);`
494
495			`if (t->father)`
496			`et_split (t);`
497
498			`pool_free (et_occurrences, t->rightmost_occ);`
499			`pool_free (et_nodes, t);`
500			`}`
501
502			`/* Releases et tree T without maintaining other nodes. */`
503
504			`void`
505			`et_free_tree_force (struct et_node *t)`
506			`{`
507			`pool_free (et_occurrences, t->rightmost_occ);`
508			`if (t->parent_occ)`
509			`pool_free (et_occurrences, t->parent_occ);`
510			`pool_free (et_nodes, t);`
511			`}`
512
513			`/* Release the alloc pools, if they are empty. */`
514
515			`void`
516			`et_free_pools (void)`
517			`{`
518			`free_alloc_pool_if_empty (&et_occurrences);`
519			`free_alloc_pool_if_empty (&et_nodes);`
520			`}`
521
522			`/* Sets father of et tree T to FATHER. */`
523
524			`void`
525			`et_set_father (struct et_node t, struct et_node father)`
526			`{`
527			`struct et_node left, right;`
528			`struct et_occ rmost, left_part, new_f_occ, p;`
529
530			`/* Update the path represented in the splay tree. */`
531			`new_f_occ = et_new_occ (father);`
532
533			`rmost = father->rightmost_occ;`
534			`et_splay (rmost);`
535
536			`left_part = rmost->prev;`
537
538			`p = t->rightmost_occ;`
539			`et_splay (p);`
540
541			`set_prev (new_f_occ, left_part);`
542			`set_next (new_f_occ, p);`
543
544			`p->depth++;`
545			`p->min++;`
546			`et_recomp_min (new_f_occ);`
547
548			`set_prev (rmost, new_f_occ);`
549
550			`if (new_f_occ->min + rmost->depth < rmost->min)`
551			`{`
552			`rmost->min = new_f_occ->min + rmost->depth;`
553			`rmost->min_occ = new_f_occ->min_occ;`
554			`}`
555
556			`t->parent_occ = new_f_occ;`
557
558			`/* Update the tree. */`
559			`t->father = father;`
560			`right = father->son;`
561			`if (right)`
562			`left = right->left;`
563			`else`
564			`left = right = t;`
565
566			`left->right = t;`
567			`right->left = t;`
568			`t->left = left;`
569			`t->right = right;`
570
571			`father->son = t;`
572
573			`#ifdef DEBUG_ET`
574			`et_check_tree_sanity (rmost);`
575			`record_path_before (rmost);`
576			`#endif`
577			`}`
578
579			`/* Splits the edge from T to its father. */`
580
581			`void`
582			`et_split (struct et_node *t)`
583			`{`
584			`struct et_node *father = t->father;`
585			`struct et_occ r, l, rmost, p_occ;`
586
587			`/* Update the path represented by the splay tree. */`
588			`rmost = t->rightmost_occ;`
589			`et_splay (rmost);`
590
591			`for (r = rmost->next; r->prev; r = r->prev)`
592			`continue;`
593			`et_splay (r);`
594
595			`r->prev->parent = NULL;`
596			`p_occ = t->parent_occ;`
597			`et_splay (p_occ);`
598			`t->parent_occ = NULL;`
599
600			`l = p_occ->prev;`
601			`p_occ->next->parent = NULL;`
602
603			`set_prev (r, l);`
604
605			`et_recomp_min (r);`
606
607			`et_splay (rmost);`
608			`rmost->depth = 0;`
609			`rmost->min = 0;`
610
611			`pool_free (et_occurrences, p_occ);`
612
613			`/* Update the tree. */`
614			`if (father->son == t)`
615			`father->son = t->right;`
616			`if (father->son == t)`
617			`father->son = NULL;`
618			`else`
619			`{`
620			`t->left->right = t->right;`
621			`t->right->left = t->left;`
622			`}`
623			`t->left = t->right = NULL;`
624			`t->father = NULL;`
625
626			`#ifdef DEBUG_ET`
627			`et_check_tree_sanity (rmost);`
628			`record_path_before (rmost);`
629
630			`et_check_tree_sanity (r);`
631			`record_path_before (r);`
632			`#endif`
633			`}`
634
635			`/* Finds the nearest common ancestor of the nodes N1 and N2. */`
636
637			`struct et_node *`
638			`et_nca (struct et_node n1, struct et_node n2)`
639			`{`
640			`struct et_occ o1 = n1->rightmost_occ, o2 = n2->rightmost_occ, *om;`
641			`struct et_occ l, r, *ret;`
642			`int mn;`
643
644			`if (n1 == n2)`
645			`return n1;`
646
647			`et_splay (o1);`
648			`l = o1->prev;`
649			`r = o1->next;`
650			`if (l)`
651			`l->parent = NULL;`
652			`if (r)`
653			`r->parent = NULL;`
654			`et_splay (o2);`
655
656			`if (l == o2 \|\| (l && l->parent != NULL))`
657			`{`
658			`ret = o2->next;`
659
660			`set_prev (o1, o2);`
661			`if (r)`
662			`r->parent = o1;`
663			`}`
664			`else`
665			`{`
666			`ret = o2->prev;`
667
668			`set_next (o1, o2);`
669			`if (l)`
670			`l->parent = o1;`
671			`}`
672
673			`if (0 < o2->depth)`
674			`{`
675			`om = o1;`
676			`mn = o1->depth;`
677			`}`
678			`else`
679			`{`
680			`om = o2;`
681			`mn = o2->depth + o1->depth;`
682			`}`
683
684			`#ifdef DEBUG_ET`
685			`et_check_tree_sanity (o2);`
686			`#endif`
687
688			`if (ret && ret->min + o1->depth + o2->depth < mn)`
689			`return ret->min_occ->of;`
690			`else`
691			`return om->of;`
692			`}`
693
694			`/* Checks whether the node UP is an ancestor of the node DOWN. */`
695
696			`bool`
697			`et_below (struct et_node down, struct et_node up)`
698			`{`
699			`struct et_occ u = up->rightmost_occ, d = down->rightmost_occ;`
700			`struct et_occ l, r;`
701
702			`if (up == down)`
703			`return true;`
704
705			`et_splay (u);`
706			`l = u->prev;`
707			`r = u->next;`
708
709			`if (!l)`
710			`return false;`
711
712			`l->parent = NULL;`
713
714			`if (r)`
715			`r->parent = NULL;`
716
717			`et_splay (d);`
718
719			`if (l == d \|\| l->parent != NULL)`
720			`{`
721			`if (r)`
722			`r->parent = u;`
723			`set_prev (u, d);`
724			`#ifdef DEBUG_ET`
725			`et_check_tree_sanity (u);`
726			`#endif`
727			`}`
728			`else`
729			`{`
730			`l->parent = u;`
731
732			`/* In case O1 and O2 are in two different trees, we must just restore the`
733			`original state. */`
734			`if (r && r->parent != NULL)`
735			`set_next (u, d);`
736			`else`
737			`set_next (u, r);`
738
739			`#ifdef DEBUG_ET`
740			`et_check_tree_sanity (u);`
741			`#endif`
742			`return false;`
743			`}`
744
745			`if (0 >= d->depth)`
746			`return false;`
747
748			`return !d->next \|\| d->next->min + d->depth >= 0;`
749			`}`
750
751			`/* Returns the root of the tree that contains NODE. */`
752
753			`struct et_node *`
754			`et_root (struct et_node *node)`
755			`{`
756			`struct et_occ occ = node->rightmost_occ, r;`
757
758			`/* The root of the tree corresponds to the rightmost occurrence in the`
759			`represented path. */`
760			`et_splay (occ);`
761			`for (r = occ; r->next; r = r->next)`
762			`continue;`
763			`et_splay (r);`
764
765			`return r->of;`
766			`}`