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Commit 95eec0d6 by Daniel Berlin
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tree-ssa-ccp.c (varying_ssa_edges): New worklist. 

2004-06-03  Daniel Berlin  <dberlin@dberlin.org>
		Kenneth Zadeck <zadeck@naturalbridge.com>

	* tree-ssa-ccp.c (varying_ssa_edges): New worklist.
	(add_var_to_ssa_edges_worklist): Add value argument.
	Update callers.
	Use new worklist.
	(process_ssa_edge_worklist): New function.
	(tree_ssa_ccp): Move worklist processing core to
	process_ssa_edge_worklist, and just call that for the two worklists.

From-SVN: r82598
parent 6ce2bcb7
Showing with 77 additions and 26 deletions
gcc/ChangeLog
2004-06-03 Steevn Bosscher <stevenb@suse.de>
2004-06-03 Daniel Berlin <dberlin@dberlin.org>
Kenneth Zadeck <zadeck@naturalbridge.com>
* tree-ssa-ccp.c (varying_ssa_edges): New worklist.
(add_var_to_ssa_edges_worklist): Add value argument.
Update callers.
Use new worklist.
(process_ssa_edge_worklist): New function.
(tree_ssa_ccp): Move worklist processing core to
process_ssa_edge_worklist, and just call that for the two worklists.
2004-06-03 Steven Bosscher <stevenb@suse.de>
* basic-block.c (tail_recursion_label_list): Don't declare.
(CLEANUP_PRE_SIBCALL): Remove. Renumber the other CLEANUP_*
......
gcc/tree-ssa-ccp.c
......@@ -98,9 +98,28 @@ static value *value_vector;
/* Worklist of SSA edges which will need reexamination as their definition
has changed. SSA edges are def-use edges in the SSA web. For each
edge, we store the definition statement or PHI node D. The destination
nodes that need to be visited are accessed using immediate_uses (D). */
nodes that need to be visited are accessed using immediate_uses
(D). */
static GTY(()) varray_type ssa_edges;
/* Identical to SSA_EDGES. For performance reasons, the list of SSA
edges is split into two. One contains all SSA edges who need to be
reexamined because their lattice value changed to varying (this
worklist), and the other contains all other SSA edges to be
reexamined (ssa_edges).
Since most values in the program are varying, the ideal situation
is to move them to that lattice value as quickly as possible.
Thus, it doesn't make sense to process any other type of lattice
value until all varying values are propagated fully, which is one
thing using the varying worklist achieves. In addition, if you
don't use a separate worklist for varying edges, you end up with
situations where lattice values move from
undefined->constant->varying instead of undefined->varying.
*/
static GTY(()) varray_type varying_ssa_edges;
static void initialize (void);
static void finalize (void);
static void visit_phi_node (tree);
......@@ -109,7 +128,7 @@ static value cp_lattice_meet (value, value);
static void visit_stmt (tree);
static void visit_cond_stmt (tree);
static void visit_assignment (tree);
static void add_var_to_ssa_edges_worklist (tree);
static void add_var_to_ssa_edges_worklist (tree, value);
static void add_outgoing_control_edges (basic_block);
static void add_control_edge (edge);
static void def_to_varying (tree);
......@@ -132,6 +151,31 @@ static void cfg_blocks_add (basic_block);
static basic_block cfg_blocks_get (void);
static bool need_imm_uses_for (tree var);
/* Process an SSA edge worklist. WORKLIST is the SSA edge worklist to
drain. This pops statements off the given WORKLIST and processes
them until there are no more statements on WORKLIST. */
static void
process_ssa_edge_worklist (varray_type *worklist)
{
/* Drain the entire worklist. */
while (VARRAY_ACTIVE_SIZE (*worklist) > 0)
{
/* Pull the statement to simulate off the worklist. */
tree stmt = VARRAY_TOP_TREE (*worklist);
stmt_ann_t ann = stmt_ann (stmt);
VARRAY_POP (*worklist);
/* visit_stmt can "cancel" reevaluation of some statements.
If it does, then in_ccp_worklist will be zero. */
if (ann->in_ccp_worklist)
{
ann->in_ccp_worklist = 0;
simulate_stmt (stmt);
}
}
}
/* Main entry point for SSA Conditional Constant Propagation. FNDECL is
the declaration for the function to optimize.
......@@ -148,7 +192,9 @@ tree_ssa_ccp (void)
initialize ();
/* Iterate until the worklists are empty. */
while (!cfg_blocks_empty_p () || VARRAY_ACTIVE_SIZE (ssa_edges) > 0)
while (!cfg_blocks_empty_p ()
|| VARRAY_ACTIVE_SIZE (ssa_edges) > 0
|| VARRAY_ACTIVE_SIZE (varying_ssa_edges) > 0)
{
if (!cfg_blocks_empty_p ())
{
......@@ -157,23 +203,12 @@ tree_ssa_ccp (void)
simulate_block (dest_block);
}
/* The SSA_EDGES worklist can get rather large. Go ahead and
drain the entire worklist each iteration through this loop. */
while (VARRAY_ACTIVE_SIZE (ssa_edges) > 0)
{
/* Pull the statement to simulate off the worklist. */
tree stmt = VARRAY_TOP_TREE (ssa_edges);
stmt_ann_t ann = stmt_ann (stmt);
VARRAY_POP (ssa_edges);
/* visit_stmt can "cancel" reevaluation of some statements.
If it does, then in_ccp_worklist will be zero. */
if (ann->in_ccp_worklist)
{
ann->in_ccp_worklist = 0;
simulate_stmt (stmt);
}
}
/* In order to move things to varying as quickly as
possible,process the VARYING_SSA_EDGES worklist first. */
process_ssa_edge_worklist (&varying_ssa_edges);
/* Now process the SSA_EDGES worklist. */
process_ssa_edge_worklist (&ssa_edges);
}
/* Now perform substitutions based on the known constant values. */
......@@ -1069,8 +1104,9 @@ initialize (void)
basic_block bb;
sbitmap virtual_var;
/* Worklist of SSA edges. */
/* Worklists of SSA edges. */
VARRAY_TREE_INIT (ssa_edges, 20, "ssa_edges");
VARRAY_TREE_INIT (varying_ssa_edges, 20, "varying_ssa_edges");
executable_blocks = sbitmap_alloc (last_basic_block);
sbitmap_zero (executable_blocks);
......@@ -1187,6 +1223,7 @@ static void
finalize (void)
{
ssa_edges = NULL;
varying_ssa_edges = NULL;
cfg_blocks = NULL;
free (value_vector);
sbitmap_free (bb_in_list);
......@@ -1258,9 +1295,9 @@ cfg_blocks_get (void)
}
/* We have just defined a new value for VAR. Add all immediate uses
of VAR to the ssa_edges worklist. */
of VAR to the ssa_edges or varying_ssa_edges worklist. */
static void
add_var_to_ssa_edges_worklist (tree var)
add_var_to_ssa_edges_worklist (tree var, value val)
{
tree stmt = SSA_NAME_DEF_STMT (var);
dataflow_t df = get_immediate_uses (stmt);
......@@ -1277,7 +1314,10 @@ add_var_to_ssa_edges_worklist (tree var)
if (ann->in_ccp_worklist == 0)
{
ann->in_ccp_worklist = 1;
VARRAY_PUSH_TREE (ssa_edges, use);
if (val.lattice_val == VARYING)
VARRAY_PUSH_TREE (varying_ssa_edges, use);
else
VARRAY_PUSH_TREE (ssa_edges, use);
}
}
}
......@@ -1341,7 +1381,7 @@ set_lattice_value (tree var, value val)
fprintf (dump_file, ". Adding definition to SSA edges.\n");
}
add_var_to_ssa_edges_worklist (var);
add_var_to_ssa_edges_worklist (var, val);
*old = val;
}
}
......
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