+/*
+ * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
+ *
+ * This file is part of libFirm.
+ *
+ * This file may be distributed and/or modified under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation and appearing in the file LICENSE.GPL included in the
+ * packaging of this file.
+ *
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+ * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE.
+ */
+
+/**
+ * @file
+ * @brief Implementation of cdep
+ * @author Christoph Mallon
+ * @version $Id$
+ */
#include <assert.h>
#include <stdlib.h>
#include "irdom.h"
#include "irgwalk.h"
#include "irnode.h"
#include "pmap.h"
+#include "obst.h"
+#include "xmalloc.h"
#include "cdep.h"
#include "irprintf.h"
+#include "irdump.h"
-typedef unsigned int uint;
+typedef struct cdep_info {
+ pmap *cdep_map; /**< A map to find the list of all control dependence nodes for a block. */
+ struct obstack obst; /**< An obstack where all cdep data lives on. */
+} cdep_info;
-static pmap* cdep_map;
+static cdep_info *cdep_data;
-cdep* find_cdep(const ir_node* block)
+/* Return a list of all control dependences of a block. */
+ir_cdep *find_cdep(const ir_node *block)
{
- return pmap_get(cdep_map, (void*)block);
+ return (ir_cdep*) pmap_get(cdep_data->cdep_map, block);
}
+/* Replace the control dependence info of old by the info of nw. */
+void exchange_cdep(ir_node *old, const ir_node *nw)
+{
+ ir_cdep *cdep = find_cdep(nw);
+ pmap_insert(cdep_data->cdep_map, old, cdep);
+}
-static void add_cdep(ir_node* node, ir_node* dep_on)
+/**
+ * Adds a control dependence from node to dep_on.
+ */
+static void add_cdep(ir_node *node, ir_node *dep_on)
{
- cdep* dep = find_cdep(node);
+ ir_cdep *dep = find_cdep(node);
#if 0
ir_fprintf(stderr, "Adding cdep of %+F on %+F\n", node, dep_on);
#endif
- if (dep == NULL) {
- cdep* newdep = malloc(sizeof(*newdep));
-
- newdep->node = dep_on;
- newdep->next = NULL;
- pmap_insert(cdep_map, node, newdep);
- } else {
- cdep* newdep;
-
- for (;;) {
- if (dep->node == dep_on) return;
- if (dep->next == NULL) break;
- dep = dep->next;
- }
- newdep = malloc(sizeof(*newdep));
- newdep->node = dep_on;
- newdep->next = NULL;
- dep->next = newdep;
- }
+ if (dep == NULL) {
+ ir_cdep *newdep = OALLOC(&cdep_data->obst, ir_cdep);
+
+ newdep->node = dep_on;
+ newdep->next = NULL;
+ pmap_insert(cdep_data->cdep_map, node, newdep);
+ } else {
+ ir_cdep *newdep;
+
+ for (;;) {
+ if (dep->node == dep_on) return;
+ if (dep->next == NULL) break;
+ dep = dep->next;
+ }
+ newdep = OALLOC(&cdep_data->obst, ir_cdep);
+ newdep->node = dep_on;
+ newdep->next = NULL;
+ dep->next = newdep;
+ }
}
+typedef struct cdep_env {
+ ir_node *start_block;
+ ir_node *end_block;
+} cdep_env;
-static void cdep_pre(ir_node* node, void* env)
+/**
+ * Pre-block-walker: calculate the control dependence
+ */
+static void cdep_pre(ir_node *node, void *ctx)
{
- uint n;
- uint i;
-
- /* special case:
- * start and end block have no control depency
- */
- if (node == get_irg_start_block(get_irn_irg(node))) return;
- if (node == get_irg_end_block(get_irn_irg(node))) return;
-
- n = get_Block_n_cfgpreds(node);
- for (i = 0; i < n; i++) {
- ir_node* pred = get_Block_cfgpred_block(node, i);
- ir_node* pdom;
- ir_node* dependee;
-
- if (is_Bad(pred)) continue;
-
- pdom = get_Block_ipostdom(pred);
- for (dependee = node; dependee != pdom; dependee = get_Block_ipostdom(dependee)) {
- assert(!is_Bad(pdom));
- add_cdep(dependee, pred);
- }
- }
+ cdep_env *env = (cdep_env*) ctx;
+ int i;
+
+ /* special case:
+ * start and end block have no control dependency
+ */
+ if (node == env->start_block) return;
+ if (node == env->end_block) return;
+
+ for (i = get_Block_n_cfgpreds(node) - 1; i >= 0; --i) {
+ ir_node *pred = get_Block_cfgpred_block(node, i);
+ ir_node *pdom;
+ ir_node *dependee;
+
+ if (is_Bad(pred)) continue;
+
+ pdom = get_Block_ipostdom(pred);
+ for (dependee = node; dependee != pdom; dependee = get_Block_ipostdom(dependee)) {
+ assert(!is_Bad(pdom));
+ add_cdep(dependee, pred);
+ }
+ }
}
-#include "irdump.h"
-
-
-static int cdep_edge_hook(FILE* F, ir_node* block)
+/**
+ * A block edge hook: add all cdep edges of block.
+ */
+static int cdep_edge_hook(FILE *F, ir_node *block)
{
-#if 0
- ir_node* pdom;
-#endif
- cdep* cd;
+ ir_cdep *cd;
#if 0
- pdom = get_Block_ipostdom(block);
+ ir_node *pdom = get_Block_ipostdom(block);
if (pdom != NULL) {
fprintf(
F,
}
#endif
- for (cd = find_cdep(block); cd != NULL; cd = cd->next) {
- fprintf(
- F,
+ for (cd = find_cdep(block); cd != NULL; cd = cd->next) {
+ fprintf(
+ F,
"edge:{sourcename:\"n%ld\" targetname:\"n%ld\" "
"linestyle:dashed color:gold}\n",
get_irn_node_nr(block), get_irn_node_nr(cd->node)
);
- }
+ }
return 0;
}
-
-void compute_cdep(ir_graph* irg)
+/* Compute the control dependence graph for a graph. */
+void compute_cdep(ir_graph *irg)
{
- cdep_map = pmap_create();
+ ir_node *rem;
+ cdep_env env;
+
+ free_cdep(irg);
+ cdep_data = XMALLOC(cdep_info);
+ obstack_init(&cdep_data->obst);
+
+ cdep_data->cdep_map = pmap_create();
- compute_postdoms(irg);
- set_Block_ipostdom(get_irg_start_block(irg), get_irg_end_block(irg));
+ assure_postdoms(irg);
- irg_block_walk_graph(irg, cdep_pre, NULL, NULL);
+ /* we must temporary change the post dominator relation:
+ the ipdom of the startblock is the end block.
+ Firm does NOT add the phantom edge from Start to End.
+ */
+ env.start_block = get_irg_start_block(irg);
+ env.end_block = get_irg_end_block(irg);
-#if 1
+ rem = get_Block_ipostdom(env.start_block);
+ set_Block_ipostdom(env.start_block, env.end_block);
+
+ irg_block_walk_graph(irg, cdep_pre, NULL, &env);
+
+#if 0
set_dump_block_edge_hook(cdep_edge_hook);
- dump_ir_block_graph(irg, "_cdep");
+ dump_ir_block_graph(irg, "_cdep");
set_dump_block_edge_hook(NULL);
+#else
+ (void) cdep_edge_hook;
#endif
- free_postdom(irg);
+ /* restore the post dominator relation */
+ set_Block_ipostdom(env.start_block, rem);
}
-
-void free_cdep(ir_graph* irg)
+/* Free the control dependence info. */
+void free_cdep(ir_graph *irg)
{
- // TODO atm leaking more memory than a small memory leaking animal
+ (void) irg;
+ if (cdep_data != NULL) {
+ pmap_destroy(cdep_data->cdep_map);
+ obstack_free(&cdep_data->obst, NULL);
+ xfree(cdep_data);
+ cdep_data = NULL;
+ }
}
-
-int is_cdep_on(const ir_node* dependee, const ir_node* candidate)
+/* Check whether dependee is (directly) control dependent on candidate. */
+int is_cdep_on(const ir_node *dependee, const ir_node *candidate)
{
- const cdep* dep;
+ const ir_cdep *dep;
for (dep = find_cdep(dependee); dep != NULL; dep = dep->next) {
if (dep->node == candidate) return 1;
return 0;
}
-
-int is_iterated_cdep_on(ir_node* dependee, ir_node* candidate)
+/* Check whether dependee is (possible iterated) control dependent on candidate. */
+int is_iterated_cdep_on(ir_node *dependee, ir_node *candidate)
{
- const cdep* dep;
+ const ir_cdep *dep;
while ((dep = find_cdep(dependee)) != NULL) {
if (dep->next != NULL) return 0;
return 0;
}
-
-ir_node* get_unique_cdep(const ir_node* block)
+/* If block is control dependent on exactly one node, return this node, else NULL. */
+ir_node *get_unique_cdep(const ir_node *block)
{
- cdep* cdep = find_cdep(block);
+ ir_cdep *cdep = find_cdep(block);
return cdep != NULL && cdep->next == NULL ? cdep->node : NULL;
}
-
-int has_multiple_cdep(const ir_node* block)
+/* Check if the given block is control dependent of more than one node. */
+int has_multiple_cdep(const ir_node *block)
{
- cdep* cdep = find_cdep(block);
+ ir_cdep *cdep = find_cdep(block);
return cdep != NULL && cdep->next != NULL;
}