/* Calculate (post)dominators in slightly super-linear time.
- Copyright (C) 2000, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+ Copyright (C) 2000, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+ Free Software Foundation, Inc.
Contributed by Michael Matz (matz@ifh.de).
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2, or (at your option)
+ the Free Software Foundation; either version 3, or (at your option)
any later version.
GCC is distributed in the hope that it will be useful, but WITHOUT
License for more details.
You should have received a copy of the GNU General Public License
- along with GCC; see the file COPYING. If not, write to the Free
- Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
- 02110-1301, USA. */
+ along with GCC; see the file COPYING3. If not see
+ <http://www.gnu.org/licenses/>. */
/* This file implements the well known algorithm from Lengauer and Tarjan
to compute the dominators in a control flow graph. A basic block D is said
#include "vecprim.h"
#include "pointer-set.h"
#include "graphds.h"
-
-/* Whether the dominators and the postdominators are available. */
-static enum dom_state dom_computed[2];
+#include "bitmap.h"
/* We name our nodes with integers, beginning with 1. Zero is reserved for
'undefined' or 'end of list'. The name of each node is given by the dfs
/* The following few fields implement the structures needed for disjoint
sets. */
- /* set_chain[x] is the next node on the path from x to the representant
+ /* set_chain[x] is the next node on the path from x to the representative
of the set containing x. If set_chain[x]==0 then x is a root. */
TBB *set_chain;
/* set_size[x] is the number of elements in the set named by x. */
void debug_dominance_info (enum cdi_direction);
void debug_dominance_tree (enum cdi_direction, basic_block);
-/* Keeps track of the*/
-static unsigned n_bbs_in_dom_tree[2];
-
/* Helper macro for allocating and initializing an array,
for aesthetic reasons. */
#define init_ar(var, type, num, content) \
static inline TBB
eval (struct dom_info *di, TBB v)
{
- /* The representant of the set V is in, also called root (as the set
+ /* The representative of the set V is in, also called root (as the set
representation is a tree). */
TBB rep = di->set_chain[v];
if (!node->father)
return NULL;
- return node->father->data;
+ return (basic_block) node->father->data;
}
/* Set the immediate dominator of the block possibly removing
existing edge. NULL can be used to remove any edge. */
-inline void
+void
set_immediate_dominator (enum cdi_direction dir, basic_block bb,
basic_block dominated_by)
{
unsigned int dir_index = dom_convert_dir_to_idx (dir);
struct et_node *node = bb->dom[dir_index];
-
+
gcc_assert (dom_computed[dir_index]);
if (node->father)
VEC (basic_block, heap) *
get_dominated_by (enum cdi_direction dir, basic_block bb)
{
- int n;
unsigned int dir_index = dom_convert_dir_to_idx (dir);
struct et_node *node = bb->dom[dir_index], *son = node->son, *ason;
VEC (basic_block, heap) *bbs = NULL;
if (!son)
return NULL;
- VEC_safe_push (basic_block, heap, bbs, son->data);
- for (ason = son->right, n = 1; ason != son; ason = ason->right)
- VEC_safe_push (basic_block, heap, bbs, ason->data);
+ VEC_safe_push (basic_block, heap, bbs, (basic_block) son->data);
+ for (ason = son->right; ason != son; ason = ason->right)
+ VEC_safe_push (basic_block, heap, bbs, (basic_block) ason->data);
return bbs;
}
/* Returns the list of basic blocks that are immediately dominated (in
direction DIR) by some block between N_REGION ones stored in REGION,
except for blocks in the REGION itself. */
-
+
VEC (basic_block, heap) *
get_dominated_by_region (enum cdi_direction dir, basic_block *region,
unsigned n_region)
return doms;
}
+/* Returns the list of basic blocks including BB dominated by BB, in the
+ direction DIR. The vector will be sorted in preorder. */
+
+VEC (basic_block, heap) *
+get_all_dominated_blocks (enum cdi_direction dir, basic_block bb)
+{
+ VEC(basic_block, heap) *bbs = NULL;
+ unsigned i;
+
+ i = 0;
+ VEC_safe_push (basic_block, heap, bbs, bb);
+
+ do
+ {
+ basic_block son;
+
+ bb = VEC_index (basic_block, bbs, i++);
+ for (son = first_dom_son (dir, bb);
+ son;
+ son = next_dom_son (dir, son))
+ VEC_safe_push (basic_block, heap, bbs, son);
+ }
+ while (i < VEC_length (basic_block, bbs));
+
+ return bbs;
+}
+
/* Redirect all edges pointing to BB to TO. */
void
redirect_immediate_dominators (enum cdi_direction dir, basic_block bb,
{
unsigned int dir_index = dom_convert_dir_to_idx (dir);
struct et_node *bb_node, *to_node, *son;
-
+
bb_node = bb->dom[dir_index];
to_node = to->dom[dir_index];
if (!bb2)
return bb1;
- return et_nca (bb1->dom[dir_index], bb2->dom[dir_index])->data;
+ return (basic_block) et_nca (bb1->dom[dir_index], bb2->dom[dir_index])->data;
}
unsigned i, first;
bitmap_iterator bi;
basic_block dom;
-
+
first = bitmap_first_set_bit (blocks);
dom = BASIC_BLOCK (first);
EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi)
You can view these as bounds for the range of dfs numbers the
nodes in the subtree of the dominator tree rooted at that node
will contain.
-
+
The dominator tree is always a simple acyclic tree, so there are
only three possible relations two nodes in the dominator tree have
to each other:
-
+
1. Node A is above Node B (and thus, Node A dominates node B)
A
B, and DFS_Number_Out of A will be >= DFS_Number_Out of B. This is
because we must hit A in the dominator tree *before* B on the walk
down, and we will hit A *after* B on the walk back up
-
+
2. Node A is below node B (and thus, node B dominates node A)
-
-
+
+
B
|
A
In the above case, DFS_Number_In of A will be >= DFS_Number_In of
B, and DFS_Number_Out of A will be <= DFS_Number_Out of B.
-
+
This is because we must hit A in the dominator tree *after* B on
the walk down, and we will hit A *before* B on the walk back up
-
+
3. Node A and B are siblings (and thus, neither dominates the other)
C
A_Dominates_B (node A, node B)
{
- return DFS_Number_In(A) <= DFS_Number_In(B)
+ return DFS_Number_In(A) <= DFS_Number_In(B)
&& DFS_Number_Out (A) >= DFS_Number_Out(B);
}
/* Return TRUE in case BB1 is dominated by BB2. */
bool
-dominated_by_p (enum cdi_direction dir, basic_block bb1, basic_block bb2)
-{
+dominated_by_p (enum cdi_direction dir, const_basic_block bb1, const_basic_block bb2)
+{
unsigned int dir_index = dom_convert_dir_to_idx (dir);
struct et_node *n1 = bb1->dom[dir_index], *n2 = bb2->dom[dir_index];
-
+
gcc_assert (dom_computed[dir_index]);
if (dom_computed[dir_index] == DOM_OK)
static basic_block
root_of_dom_tree (enum cdi_direction dir, basic_block bb)
{
- return et_root (bb->dom[dom_convert_dir_to_idx (dir)])->data;
+ return (basic_block) et_root (bb->dom[dom_convert_dir_to_idx (dir)])->data;
}
/* See the comment in iterate_fix_dominators. Finds the immediate dominators
Then, we need to establish the dominance relation among the basic blocks
in BBS. We split the dominance tree by removing the immediate dominator
- edges from BBS, creating a forrest F. We form a graph G whose vertices
+ edges from BBS, creating a forest F. We form a graph G whose vertices
are BBS and ENTRY and X -> Y is an edge of G if there exists an edge
- X' -> Y in CFG such that X' belongs to the tree of the dominance forrest
+ X' -> Y in CFG such that X' belongs to the tree of the dominance forest
whose root is X. We then determine dominance tree of G. Note that
for X, Y in BBS, X dominates Y in CFG if and only if X dominates Y in G.
In this step, we can use arbitrary algorithm to determine dominators.
dom_i = (size_t) *pointer_map_contains (map, dom);
/* Do not include parallel edges to G. */
- if (bitmap_bit_p (g->vertices[dom_i].data, i))
+ if (bitmap_bit_p ((bitmap) g->vertices[dom_i].data, i))
continue;
- bitmap_set_bit (g->vertices[dom_i].data, i);
+ bitmap_set_bit ((bitmap) g->vertices[dom_i].data, i);
add_edge (g, dom_i, i);
}
}
gcc_assert (!bb->dom[dir_index]);
n_bbs_in_dom_tree[dir_index]++;
-
+
bb->dom[dir_index] = et_new_tree (bb);
if (dom_computed[dir_index] == DOM_OK)
unsigned int dir_index = dom_convert_dir_to_idx (dir);
struct et_node *son = bb->dom[dir_index]->son;
- return son ? son->data : NULL;
+ return (basic_block) (son ? son->data : NULL);
}
/* Returns the next dominance son after BB in the dominator or postdominator
unsigned int dir_index = dom_convert_dir_to_idx (dir);
struct et_node *next = bb->dom[dir_index]->right;
- return next->father->son == next ? NULL : next->data;
+ return (basic_block) (next->father->son == next ? NULL : next->data);
}
/* Return dominance availability for dominance info DIR. */
}
/* Prints to stderr representation of the dominance tree (for direction DIR)
- rooted in ROOT, indented by INDENT tabelators. If INDENT_FIRST is false,
+ rooted in ROOT, indented by INDENT tabulators. If INDENT_FIRST is false,
the first line of the output is not indented. */
static void
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