/*
- * Project: libFIRM
- * File name: ir/opt/gvn_pre.c
- * Purpose: Global Value Numbering Partial Redundancy Elimination
- * (VanDrunen Hosking 2004)
- * Author: Michael Beck, Rubino Geiss
- * Created:
- * CVS-ID: $Id$
- * Copyright: (c) 1998-2006 Universität Karlsruhe
- * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
+ * Copyright (C) 1995-2007 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 Global Value Numbering Partial Redundancy Elimination
+ * (VanDrunen Hosking 2004)
+ * @author Michael Beck, Rubino Geiss
+ * @version $Id$
+ * @summary
+ *
+ * Currently completely broken because our sets do NOT preserve
+ * the topological sort!
+ */
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
+#include "iroptimize.h"
+
#include <assert.h>
#include "irgraph_t.h"
#include "irdom.h"
#include "irouts.h"
#include "pset.h"
+#include "set.h"
#include "irgopt.h"
#include "iropt_t.h"
#include "irprintf.h"
#include "ircons.h"
#include "irgmod.h"
#include "debug.h"
-#include "gvn_pre.h"
+#include "xmalloc.h"
+
+/** The debug module handle. */
+DEBUG_ONLY(static firm_dbg_module_t *dbg;)
+
+
+/** A value set. */
+typedef struct set value_set;
+
+/** A node set. */
+typedef struct pset node_set;
+
+/** An entry in the value set. */
+typedef struct value_entry {
+ ir_node *node; /**< the node */
+ ir_node *value; /**< the value of the node */
+} value_entry;
-/* */
+/** Additional info we need for every block. */
typedef struct block_info {
- pset *nodes; /**< the set of nodes per block */
- pset *avail_out; /**< the Avail_out set for a block */
- pset *antic_in; /**< the Antic_in set for a block */
- pset *new_set; /**< the set of all new values for a block */
- ir_node *avail; /**< the get_map(avail, block) result */
- int not_found; /**< non-zero, if avail was not found in this block */
- struct block_info *next;
+ node_set *nodes; /**< The set of nodes per block. */
+ value_set *avail_out; /**< The Avail_out set for a block. */
+ node_set *antic_in; /**< The Antic_in set for a block. */
+ value_set *new_set; /**< The set of all new values for a block. */
+ ir_node *avail; /**< The get_map(avail, block) result. */
+ int not_found; /**< Non-zero, if avail was not found in this block. */
+ struct block_info *next; /**< Links all entries, so we can recover the sets easily. */
} block_info;
+/**
+ * A pair of nodes that must be exchanged.
+ * We must defer the exchange because our hash-sets cannot
+ * find an already replace node else.
+ */
+typedef struct elim_pair {
+ ir_node *old_node; /**< The old node that will be replaced. */
+ ir_node *new_node; /**< The new node. */
+ struct elim_pair *next; /**< Links all entries in a list. */
+} elim_pair;
+
+/** The environment for the GVN-PRE algorithm */
typedef struct pre_env {
- struct obstack *obst; /**< the obstack to allocate on */
- ir_node *start_block; /**< the start block of the current graph */
- ir_node *end_block; /**< the end block of the current graph */
- block_info *list; /**< links all block info entires for easier recovery */
- int changes; /**< non-zero, if calculation of Antic_in has changed */
+ struct obstack *obst; /**< The obstack to allocate on. */
+ node_set *trans_set; /**< The set of all translated values. */
+ ir_node *start_block; /**< The start block of the current graph. */
+ ir_node *end_block; /**< The end block of the current graph */
+ block_info *list; /**< Links all block info entires for easier recovery. */
+ elim_pair *pairs; /**< A list of node pairs that must be eliminated. */
+ char changes; /**< Non-zero, if calculation of Antic_in has changed. */
+ char first_iter; /**< non-zero for first iteration */
} pre_env;
-/** The debug module handle. */
-static firm_dbg_module_t *dbg;
+/* ---------- Functions for Node sets ---------- */
+
+#define node_set_first(s) pset_first(s)
+#define node_set_next(s) pset_next(s)
+#define node_set_break(s) pset_break(s)
+#define node_set_foreach(v, s) for ((v) = node_set_first(s); (v); (v) = node_set_next(s))
/**
- * returns non-zero if a node is movable.
+ * Creates a new node set.
*/
-static int is_nice_value(ir_node *n) {
- ir_mode *mode = get_irn_mode(n);
+static node_set *new_node_set(void) {
+ return new_pset(identities_cmp, 8);
+}
- if (!mode_is_data(mode))
- return 0;
- if (is_irn_constlike(n))
- return 0;
- return (get_irn_pinned(n) != op_pin_state_pinned);
+/**
+ * Deletes a node set.
+ */
+static void del_node_set(node_set *set) {
+ del_pset(set);
+}
+
+/**
+ * Add a node to the set.
+ */
+static ir_node *node_add(node_set *set, ir_node *node) {
+ return identify_remember(set, node);
+}
+
+/**
+ * Remove a node from a node set.
+ */
+static void node_set_remove(node_set *set, ir_node *node) {
+ pset_remove(set, node, ir_node_hash(node));
+}
+
+/**
+ * Return the number of entries in a node set.
+ */
+static int node_set_count(node_set *set) {
+ return pset_count(set);
+}
+
+#if 0
+/** computes dst = dst \/ src for node sets */
+static void node_union(node_set *dst, node_set *src)
+{
+ ir_node *entry;
+ node_set_foreach(entry, src) {
+ node_add(dst, entry);
+ }
+}
+#endif
+
+/**
+ * Lookup a node in a node set.
+ */
+static ir_node *node_lookup(node_set *set, ir_node *n)
+{
+ return pset_find(set, n, ir_node_hash(n));
+}
+
+
+/* ---------- Functions for Value sets ---------- */
+
+#define value_set_foreach(v, s) for ((v) = set_first(s); (v); (v) = set_next(s))
+
+/**
+ * calculate a hash value for a value represented by a node
+ */
+static unsigned value_hash(ir_node *value) {
+ return ir_node_hash(value);
+}
+
+/**
+ * Compare two value entries.
+ */
+static int value_cmp(const void *elt, const void *key, size_t size)
+{
+ const value_entry *e1 = elt;
+ const value_entry *e2 = key;
+ (void) size;
+
+ return identities_cmp(e1->value, e2->value);
+}
+
+/** Create a new value set. */
+static value_set *new_value_set(void) {
+ return new_set(value_cmp, 8);
+}
+
+/** Deletes a value set. */
+static void del_value_set(value_set *set) {
+ del_set(set);
+}
+
+/**
+ * Add a node node representing the value value to the set.
+ */
+static value_entry *value_add(value_set *set, ir_node *node, ir_node *value)
+{
+ value_entry key;
+ key.node = node;
+ key.value = value;
+ return set_insert(set, &key, sizeof(key), value_hash(value));
+}
+
+/** computes dst = dst \/ src for value sets */
+static void value_union(value_set *dst, value_set *src)
+{
+ value_entry *entry;
+ value_set_foreach(entry, src)
+ value_add(dst, entry->node, entry->value);
+}
+
+/** computes dst = dst \/ (value_set)src for value sets */
+static void value_union_nodes(value_set *dst, node_set *src)
+{
+ ir_node *n;
+ node_set_foreach(n, src)
+ value_add(dst, n, n);
}
-#define pset_foreach(v, s) for ((v) = pset_first(s); (v); (v) = pset_next(s))
+/**
+ * Lookup a value in a value set.
+ */
+static ir_node *value_lookup(value_set *value_set, ir_node *n)
+{
+ value_entry key, *e;
-typedef unsigned (*HASH_FUNC)(void *);
+ key.value = n;
+ e = set_find(value_set, &key, sizeof(key), value_hash(n));
+ return e ? e->node : NULL;
+}
-/** computes dst = dst \/ src */
-static void pset_union(pset *dst, pset *src, HASH_FUNC hash)
+/**
+ * Add or replace a value in a set by an node computing the same
+ * value in a dominator block.
+ *
+ * @return non-zero if a replacement took place
+ */
+static int value_add_or_replace(value_set *set, ir_node *node, ir_node *value)
{
- void *entry;
+ value_entry *e = value_add(set, node, value);
+
+ if (e->node != node) {
+ /* node must dominate old one here */
+ assert(block_dominates(get_nodes_block(node), get_nodes_block(e->node)));
- pset_foreach(entry, src) {
- pset_insert(dst, entry, hash(entry));
+ e->node = node;
+ return 1;
}
+ return 0;
}
-#define pset_union(d, s) pset_union(d, s, (HASH_FUNC)ir_node_hash)
+/**
+ * Returns non-zero if a node is movable.
+ */
+static int is_nice_value(ir_node *n) {
+ ir_mode *mode;
+
+ while (is_Proj(n))
+ n = get_Proj_pred(n);
+ mode = get_irn_mode(n);
+ /*
+ * FIXME: For now, we cannot handle Div/even if it's movable.
+ * That should be fixed.
+ */
+ if (!mode_is_data(mode))
+ return 0;
+ if (is_irn_constlike(n))
+ return 0;
+ return (get_irn_pinned(n) != op_pin_state_pinned);
+}
#ifdef DEBUG_libfirm
/**
- * Dump the Avail or Antic sets
+ * Dump a set.
*/
-static void dump_set(pset *set, char *txt, ir_node *block)
+static void dump_node_set(node_set *set, char *txt, ir_node *block)
{
ir_node *n;
int i;
DB((dbg, LEVEL_2, "%s(%+F) = {\n", txt, block));
i = 0;
- pset_foreach(n, set) {
+ node_set_foreach(n, set) {
if ((i & 3) == 3)
DB((dbg, LEVEL_2, "\n"));
DB((dbg, LEVEL_2, " %+F,", n));
DB((dbg, LEVEL_2, "\n}\n"));
} /* dump_set */
+/**
+ * Dump a value set.
+ */
+static void dump_value_set(value_set *set, char *txt, ir_node *block)
+{
+ value_entry *e;
+ int i;
+
+ DB((dbg, LEVEL_2, "%s(%+F) = {\n", txt, block));
+ i = 0;
+ value_set_foreach(e, set) {
+ if ((i & 3) == 3)
+ DB((dbg, LEVEL_2, "\n"));
+ if (e->node != e->value)
+ DB((dbg, LEVEL_2, " %+F(%+F),", e->node, e->value));
+ else
+ DB((dbg, LEVEL_2, " %+F,", e->node));
+ ++i;
+ }
+ DB((dbg, LEVEL_2, "\n}\n"));
+} /* dump_set */
+
#else
-#define dump_set(set, txt, block)
+#define dump_node_set(set, txt, block)
+#define dump_value_set(set, txt, block)
#endif /* DEBUG_libfirm */
}
/**
- * computes Avail_out(block):
+ * Computes Avail_out(block):
*
* Avail_in(block) = Avail_out(dom(block))
* Avail_out(block) = Avail_in(block) \/ Nodes(block)
if (block == env->end_block)
return;
- pset_union(info->avail_out, info->nodes);
-
- /* the root has no dominator */
+ /*
+ * First add all nodes from the dominator.
+ * This must be done to ensure that Antic_out contains the leader
+ * for every node. The root has no dominator.
+ */
if (block != env->start_block) {
dom_blk = get_Block_idom(block);
assert(is_Block(dom_blk));
dom_info = get_block_info(dom_blk);
assert(dom_info);
- pset_union(info->avail_out, dom_info->avail_out);
+ value_union(info->avail_out, dom_info->avail_out);
}
- dump_set(info->avail_out, "Avail_out", block);
+ value_union_nodes(info->avail_out, info->nodes);
+
+ dump_value_set(info->avail_out, "Avail_out", block);
}
-/*
- * Implement phi_translate
+/**
+ * returns non-zero if a tree node must be copied because of
+ * a phi_translate.
*/
-static ir_node *phi_translate(ir_node *node, ir_node *block, int pos, pre_env *env)
+static int need_copy(ir_node *node, ir_node *block)
{
- ir_node *pred_block;
+ int i, arity;
+
+ /* Phi always stop the recursion */
+ if (is_Phi(node))
+ return get_irn_intra_n(node, -1) == block;
+
+ if (! is_nice_value(node))
+ return 0;
+
+ /* check predecessor */
+ arity = get_irn_intra_arity(node);
+ for (i = 0; i < arity; ++i) {
+ ir_node *pred = get_irn_intra_n(node, i);
+ ir_node *local_bl = get_irn_intra_n(pred, -1);
+ ir_node *leader = value_lookup(get_block_info(local_bl)->avail_out, pred);
+
+ pred = leader != NULL ? leader : pred;
+ if (need_copy(pred, block))
+ return 1;
+ }
+ return 0;
+}
+
+/**
+ * Translate a node
+ */
+static ir_node *translate(ir_node *node, ir_node *block, int pos, pre_env *env)
+{
+ int i, arity, need_new;
+ ir_node *res, *nn, **in;
+
+ /* Phi always stop the recursion */
+ if (is_Phi(node)) {
+ if (get_irn_intra_n(node, -1) == block)
+ return get_Phi_pred(node, pos);
+ return node;
+ }
+
+ if (! is_nice_value(node))
+ return node;
+
+ arity = get_irn_intra_arity(node);
+ if (arity > 0) {
+ NEW_ARR_A(ir_node *, in, arity);
+ i = arity - 1;
+ need_new = 0;
+ do {
+ ir_node *pred = get_irn_intra_n(node, i);
+ ir_node *pred_blk = get_irn_intra_n(pred, -1);
+ ir_node *leader = value_lookup(get_block_info(pred_blk)->avail_out, pred);
+ in[i] = translate(leader ? leader : pred, block, pos, env);
+ need_new |= (in[i] != pred);
+ --i;
+ } while(i >= 0);
+ if (! need_new)
+ return node;
+
+ /* create a copy */
+ nn = new_ir_node(
+ get_irn_dbg_info(node),
+ current_ir_graph,
+ get_Block_cfgpred_block(block, pos),
+ get_irn_op(node),
+ get_irn_mode(node),
+ arity,
+ in);
+ /* We need the attribute copy here, because the Hash value of a
+ node might depend on that. */
+ copy_node_attr(node, nn);
+ res = node_add(env->trans_set, nn);
+ if (nn != res)
+ obstack_free(env->obst, nn);
+ else
+ DB((dbg, LEVEL_2, "--> Translate %+F in <%+F,%d> into %+F\n", node, block, pos, res));
+ return res;
+ }
+ return node;
+}
+
+#if 0
+/**
+ * Implements phi_translate.
+ */
+static ir_node *deep_phi_translate(ir_node *node, ir_node *block, int pos, pre_env *env)
+{
+ struct obstack *old;
ir_node *res;
- int i, arity = get_irn_intra_arity(node);
+
+ if (! need_copy(node, block))
+ return node;
+
+ /* Create a copy of the node in the pos'th predecessor block.
+ Use our environmental obstack, as these nodes are always
+ temporary. */
+ old = current_ir_graph->obst;
+ current_ir_graph->obst = env->obst;
+ res = translate(node, block, pos, env);
+ current_ir_graph->obst = old;
+
+ return res;
+} /* phi_translate */
+#endif
+
+/**
+ * Implements phi_translate.
+ */
+static ir_node *phi_translate(ir_node *node, ir_node *block, int pos, pre_env *env)
+{
+ ir_node *nn, *res;
+ int i, arity;
struct obstack *old;
if (is_Phi(node)) {
- if (get_nodes_block(node) == block)
+ if (get_irn_intra_n(node, -1) == block)
return get_Phi_pred(node, pos);
return node;
}
+ arity = get_irn_intra_arity(node);
+
/* check if the node has at least one Phi predecessor */
for (i = 0; i < arity; ++i) {
- ir_node *phi = get_irn_intra_n(node, i);
- if (is_Phi(phi) && get_nodes_block(phi) == block)
+ ir_node *pred = get_irn_intra_n(node, i);
+ ir_node *pred_bl = get_irn_intra_n(pred, -1);
+ ir_node *leader = value_lookup(get_block_info(pred_bl)->avail_out, pred);
+
+ leader = leader != NULL ? leader : pred;
+ if (is_Phi(leader) && get_irn_intra_n(pred, -1) == block)
break;
}
if (i >= arity) {
return node;
}
- pred_block = get_Block_cfgpred_block(block, pos);
-
/* Create a copy of the node in the pos'th predecessor block.
Use our environmental obstack, as these nodes are always
temporary. */
old = current_ir_graph->obst;
current_ir_graph->obst = env->obst;
- res = new_ir_node(
- get_irn_dbg_info(node),
- current_ir_graph,
- pred_block,
- get_irn_op(node),
- get_irn_mode(node),
- arity,
- get_irn_in(node));
+ nn = new_ir_node(
+ get_irn_dbg_info(node),
+ current_ir_graph,
+ NULL,
+ get_irn_op(node),
+ get_irn_mode(node),
+ arity,
+ get_irn_in(node));
/* We need the attribute copy here, because the Hash value of a
node might depend on that. */
- copy_node_attr(node, res);
- current_ir_graph->obst = old;
+ copy_node_attr(node, nn);
- for (i = -1; i < arity; ++i) {
- ir_node *pred = get_irn_intra_n(node, i);
+ set_irn_n(nn, -1, get_irn_intra_n(node, -1));
+ for (i = 0; i < arity; ++i) {
+ ir_node *pred = get_irn_intra_n(node, i);
+ ir_node *pred_bl = get_irn_intra_n(pred, -1);
+ ir_node *leader = value_lookup(get_block_info(pred_bl)->avail_out, pred);
- if (! is_Phi(pred))
- set_irn_n(res, i, pred);
+ leader = leader != NULL ? leader : pred;
+ if (is_Phi(leader) && get_irn_intra_n(pred, -1) == block)
+ set_irn_n(nn, i, get_Phi_pred(leader, pos));
else
- set_irn_n(res, i, get_Phi_pred(pred, pos));
+ set_irn_n(nn, i, leader);
}
- set_irn_link(res, NULL);
+ res = node_add(env->trans_set, nn);
+ current_ir_graph->obst = old;
+
+ if (nn != res)
+ obstack_free(env->obst, nn);
+ else {
+ DB((dbg, LEVEL_2, "--> Translate %+F in <%+F,%d> into %+F\n", node, block, pos, res));
+ }
+ return res;
+} /* phi_translate */
+
+/**
+ * check if a node n is clean in block block.
+ */
+static int _is_clean(ir_node *n, ir_node *block)
+{
+ int i;
+
+ if (get_nodes_block(n) != block)
+ return 1;
+ if (is_Phi(n))
+ return 1;
+
+ if (irn_visited(n))
+ return 0;
+
+ if (! is_nice_value(n))
+ goto bad;
+ for (i = get_irn_arity(n) - 1; i >= 0; --i) {
+ ir_node *pred = get_irn_n(n, i);
+ if (! _is_clean(pred, block))
+ goto bad;
+ }
+ return 1;
+bad:
+ mark_irn_visited(n);
+ return 0;
+}
+
+/**
+ * check if a node n is clean.
+ */
+static int is_clean(ir_node *n)
+{
+ int res = _is_clean(n, get_nodes_block(n));
return res;
}
+/**
+ * Clean a node set.
+ * This function is called for node sets with is_clean
+ * nodes only, so we must just remove nodes that don't
+ * have available inputs
+ */
+static void clean_node_set(node_set *set, ir_node *blk)
+{
+ ir_node *n, *pred, *pred_blk;
+ int i;
+
+restart:
+ for (n = node_set_first(set); n; n = node_set_next(set)) {
+ for (i = get_irn_intra_arity(n) - 1; i >= 0; --i) {
+ pred = get_irn_intra_n(n, i);
+
+ pred_blk = get_irn_intra_n(pred, -1);
+ if (block_dominates(pred_blk, blk))
+ continue;
+ /* pred do not dominate it, but may be in the set */
+ if (node_lookup(set, pred) != NULL)
+ continue;
+ /* we found a node that must be removed */
+ node_set_break(set);
+ node_set_remove(set, n);
+ DB((dbg, LEVEL_2, "<-- Cleaning %+F\n", n));
+ goto restart;
+ }
+ }
+}
+
/**
* computes Antic_in(block):
- *
*/
static void compute_antic(ir_node *block, void *ctx)
{
if (block == env->start_block)
return;
- size = pset_count(info->antic_in);
+ size = node_set_count(info->antic_in);
- /* the root has no dominator */
+ /* the end block has no successor */
if (block != env->end_block) {
int n_succ = get_Block_n_cfg_outs(block);
if (n_succ == 1) {
- ir_node *node;
+ ir_node *node, *list;
int i, pos = -1;
- pset *nodes = new_pset(identities_cmp, 8);
-
- pset_union(nodes, info->nodes);
/* find blocks position in succ's block predecessors */
succ = get_Block_cfg_out(block, 0);
assert(pos >= 0);
succ_info = get_block_info(succ);
- for (node = pset_first(succ_info->antic_in);
- node;
- node = pset_next(succ_info->antic_in)) {
+ /* translate into list: we cannot insert into a set we iterate
+ * and succ might be equal to block for endless loops */
+ list = NULL;
+ node_set_foreach(node, succ_info->antic_in) {
+ set_irn_link(node, list);
+ list = node;
+ }
+ for (node = list; node; node = get_irn_link(node)) {
ir_node *trans = phi_translate(node, succ, pos, env);
- identify_remember(nodes, trans);
-
- /* add all predecessors of node */
- for (i = get_irn_arity(node) - 1; i >= 0; --i) {
- ir_node *pred = get_irn_n(node, i);
- ir_node *trans = phi_translate(pred, succ, pos, env);
-
- if (is_nice_value(trans))
- identify_remember(nodes, trans);
- }
+ if (is_clean(trans))
+ node_add(info->antic_in, trans);
}
- /* this step calculates Antic_in(b) = Antic_out(b) \/ Nodes(b) */
- pset_union(info->antic_in, nodes);
- del_pset(nodes);
- }
+ }
else {
ir_node *n, *succ0;
block_info *succ0_info;
first one. */
succ0 = get_Block_cfg_out(block, 0);
succ0_info = get_block_info(succ0);
- for (n = pset_first(succ0_info->antic_in);
- n;
- n = pset_next(succ0_info->antic_in)) {
+ node_set_foreach(n, succ0_info->antic_in) {
/* we need the disjoint */
for (i = 1; i < n_succ; ++i) {
ir_node *succ = get_Block_cfg_out(block, i);
block_info *succ_info = get_block_info(succ);
- if (pset_find(succ_info->antic_in, n, ir_node_hash(n)) == NULL)
+ if (node_lookup(succ_info->antic_in, n) == NULL)
break;
}
if (i >= n_succ) {
/* we found a node that is common in all Antic_in(succ(b)),
put it in Antic_in(b) */
- identify_remember(info->antic_in, n);
+ node_add(info->antic_in, n);
}
}
- /* this step calculates Antic_in(b) = Antic_out(b) \/ Nodes(b) */
- pset_union(info->antic_in, info->nodes);
+ }
+
+ /*
+ * This step calculates Antic_in(b) = Antic_out(b) \/ Nodes(b).
+ * It is enough to do this in the first iteration, because
+ * the set info->nodes is not changed anymore.
+ */
+ if (env->first_iter) {
+ ir_node *n;
+ node_set_foreach(n, info->nodes) {
+ if (is_clean(n))
+ node_add(info->antic_in, n);
+ }
}
}
- if (size != pset_count(info->antic_in))
+// clean_node_set(info->antic_in, block);
+ (void) clean_node_set;
+
+ dump_node_set(info->antic_in, "Antic_in", block);
+ if (size != node_set_count(info->antic_in)) {
/* the Antic_in set has changed */
env->changes |= 1;
-
- dump_set(info->antic_in, "Antic_in", block);
+ }
} /* compute_antic */
/**
{
int i;
pre_env *env = ctx;
- block_info *info = obstack_alloc(env->obst, sizeof(block_info));
+ block_info *info = obstack_alloc(env->obst, sizeof(*info));
set_irn_link(block, info);
- info->nodes = new_pset(identities_cmp, 8);
- info->antic_in = new_pset(identities_cmp, 8);
- info->avail_out = new_pset(identities_cmp, 8);
+ info->nodes = new_node_set();
+ info->antic_in = new_node_set();
+ info->avail_out = new_value_set();
info->avail = NULL;
info->not_found = 0;
info->new_set = NULL;
info->next = env->list;
- env->list = info->next;
+ env->list = info;
/* fill the nodes set, we will need it later */
for (i = get_irn_n_outs(block) - 1; i >= 0; --i) {
ir_node *n = get_irn_out(block, i);
- /* clear the link field here, we need it later */
set_irn_link(n, NULL);
/* we cannot optimize pinned nodes, so do not remember them */
if (is_nice_value(n))
- identify_remember(info->nodes, n);
- else if (is_Phi(n) && get_irn_mode(n) != mode_M) {
- /*
- * Phis are "temporaries" and must be handled special:
- * They are avail, but are not in Antic_in
- */
- identify_remember(info->avail_out, n);
- }
- }
-}
-
-/**
- * Compare two nodes for equal operands.
- */
-static int operands_equal(ir_node *n1, ir_node *n2)
-{
- int i, arity = get_irn_arity(n1);
- assert(n1->op == n2->op && arity == get_irn_arity(n2));
- for (i = 0; i < arity; ++i)
- if (get_irn_n(n1, i) != get_irn_n(n2, i))
- return 0;
- return 1;
-}
-
-/**
- * Get the leader of an expression. In Firm, only
- * Phi nodes can be leaders, all other 'leader' are
- * handled by the identify_remember mechanism right.
- */
-static ir_node *find_leader(ir_node *n)
-{
- ir_node *l = get_irn_link(n);
-
- if (l) {
- assert(is_Phi(l));
- return l;
+ node_add(info->nodes, n);
}
- return n;
-}
-
-static ir_node *has_leader(ir_node *n)
-{
- ir_node *l = get_irn_link(n);
-
- if (l) {
- assert(is_Phi(l));
- return l;
- }
- return NULL;
}
/**
static void insert_nodes(ir_node *block, void *ctx)
{
pre_env *env = ctx;
- ir_node *v, *idom, *first_s;
+ value_entry *entry;
+ ir_node *e, *idom, *first_s, *worklist;
block_info *curr_info, *idom_info;
int pos, arity = get_irn_intra_arity(block);
- int all_same, by_some;
+ int all_same, by_some, updated;
+ /* ensure that even the start block has a new_set */
curr_info = get_block_info(block);
- curr_info->new_set = new_pset(identities_cmp, 8);
+ if (curr_info->new_set)
+ del_value_set(curr_info->new_set);
+ curr_info->new_set = new_value_set();
if (block == env->start_block)
return;
idom_info = get_block_info(idom);
/* update the new_sets */
- pset_union(curr_info->new_set, idom_info->new_set);
- pset_foreach(v, idom_info->new_set) {
- ir_node *old = identify_remember(idom_info->new_set, v);
-
- if (old != v) {
- /* v must dominate old here */
- assert(block_dominates(get_nodes_block(v), get_nodes_block(old)));
-
- pset_remove(curr_info->avail_out, old, ir_node_hash(old));
- identify_remember(curr_info->avail_out, v);
- }
+ updated = 0;
+ dump_value_set(idom_info->new_set, "[New Set]", idom);
+ value_set_foreach(entry, idom_info->new_set) {
+ updated |= value_add_or_replace(curr_info->avail_out, entry->node, entry->value);
}
- dump_set(curr_info->avail_out, "[Avail_out]", block);
+ if (updated)
+ dump_value_set(curr_info->avail_out, "Updated [Avail_out]", block);
if (arity <= 1)
return;
- pset_foreach(v, curr_info->antic_in) {
- /*
- * If we already have a leader for this node,
- * it is totally redundant.
- */
- if (has_leader(v))
- continue;
+ /* convert the set into a list. This allows the removal of
+ * elements from the set */
+ worklist = NULL;
+ node_set_foreach(e, curr_info->antic_in) {
+ set_irn_link(e, worklist);
+ worklist = e;
+ }
+
+ for (e = worklist; e != NULL; e = get_irn_link(e)) {
+ ir_mode *mode;
/* If the value was already computed in the dominator, then
it is totally redundant. Hence we have nothing to insert. */
- if (pset_find(idom_info->avail_out, v, ir_node_hash(v))) {
+ if (value_lookup(idom_info->avail_out, e)) {
// DB((dbg, LEVEL_2, "Found %+F from block %+F avail in dom %+F\n", v, block, idom));
continue;
}
- all_same = 1;
by_some = 0;
+ all_same = 1;
first_s = NULL;
+ mode = NULL;
/* for all predecessor blocks */
for (pos = 0; pos < arity; ++pos) {
block_info *pred_info;
ir_node *pred_blk = get_Block_cfgpred_block(block, pos);
- ir_node *trans, *found;
+ ir_node *e_prime, *v_prime, *e_dprime;
/* ignore bad blocks. */
if (is_Bad(pred_blk))
continue;
- trans = phi_translate(v, block, pos, env);
+ e_prime = phi_translate(e, block, pos, env);
+ v_prime = e_prime;
pred_info = get_block_info(pred_blk);
- found = pset_find(pred_info->avail_out, trans, ir_node_hash(trans));
+ e_dprime = value_lookup(pred_info->avail_out, v_prime);
- if (found == NULL) {
+ if (e_dprime == NULL) {
all_same = 0;
- pred_info->avail = trans;
+ pred_info->avail = e_prime;
pred_info->not_found = 1;
}
else {
- found = find_leader(found);
- pred_info->avail = found;
+ mode = get_irn_mode(e_dprime);
+ e_dprime = e_dprime;
+ pred_info->avail = e_dprime;
pred_info->not_found = 0;
by_some = 1;
if (first_s == NULL)
- first_s = found;
- else if (first_s != found)
+ first_s = e_dprime;
+ else if (first_s != e_dprime)
all_same = 0;
- DB((dbg, LEVEL_2, "Found %+F from block %+F as %+F in pred %+F\n", v, block, found, pred_blk));
+ DB((dbg, LEVEL_2, "Found %+F from block %+F as %+F in pred %+F\n", e, block, e_dprime, pred_blk));
} /* if */
} /* for */
it's defined by some predecessor, it is partially redundant. */
if (! all_same && by_some) {
ir_node *phi, **in;
- ir_mode *mode = NULL;
- DB((dbg, LEVEL_1, "Partial redundant %+F from block %+F found\n", v, block));
+
+ DB((dbg, LEVEL_1, "Partial redundant %+F from block %+F found\n", e, block));
in = xmalloc(arity * sizeof(*in));
/* for all predecessor blocks */
/* ignore blocks that already have the expression */
if (pred_info->not_found) {
- ir_node *avail = pred_info->avail;
+ ir_node *e_prime = pred_info->avail;
ir_node *nn;
- assert(! is_Phi(avail));
-
- mode = get_irn_mode(avail);
- nn = new_ir_node(
- get_irn_dbg_info(avail),
- current_ir_graph, pred_blk,
- get_irn_op(avail),
- mode,
- get_irn_arity(avail),
- get_irn_in(avail) + 1);
-
- pred_info->avail = identify_remember(pred_info->avail_out, nn);
+ if (!is_Phi(e_prime)) {
+ mode = get_irn_mode(e_prime);
+ nn = new_ir_node(
+ get_irn_dbg_info(e_prime),
+ current_ir_graph, pred_blk,
+ get_irn_op(e_prime),
+ mode,
+ get_irn_arity(e_prime),
+ get_irn_in(e_prime) + 1);
+ copy_node_attr(e_prime, nn);
+
+ DB((dbg, LEVEL_2, "New node %+F in block %+F created\n", nn, pred_blk));
+ pred_info->avail = value_add(pred_info->avail_out, nn, e_prime)->node;
+ }
}
in[pos] = pred_info->avail;
} /* for */
phi = new_r_Phi(current_ir_graph, block, arity, in, mode);
free(in);
- identify_remember(curr_info->avail_out, phi);
- identify_remember(curr_info->new_set, phi);
- /* v might be translated, so add it here */
- identify_remember(curr_info->avail_out, v);
- identify_remember(curr_info->new_set, v);
- set_irn_link(v, phi);
- DB((dbg, LEVEL_2, "New %+F for redundant %+F created\n", phi, v));
+ value_add_or_replace(curr_info->avail_out, phi, e);
+ value_add(curr_info->new_set, phi, e);
+ DB((dbg, LEVEL_2, "New %+F for redundant %+F created\n", phi, e));
+
+ /* the good case: we really replace an instruction */
+ node_set_remove(curr_info->antic_in, e);
+
env->changes |= 1;
} /* if */
- } /* pset_foreach */
+ } /* node_set_foreach */
} /* insert_nodes */
/**
- * Do the elimination step
+ * Do the elimination step: collect all changes
+ * We cannot do the changes right here, as this would change
+ * the hash values of the nodes in the avail_out set!
*/
-static void eliminate_nodes(ir_node *block, void *ctx)
+static void collect_elim_pairs(ir_node *block, void *ctx)
{
+ pre_env *env = ctx;
block_info *curr_info = get_block_info(block);
ir_node *v;
- pset_foreach(v, curr_info->nodes) {
- ir_node *l = identify_remember(curr_info->avail_out, v);
+ dump_node_set(curr_info->nodes, "Updating nodes", block);
+ node_set_foreach(v, curr_info->nodes) {
+ ir_node *l = value_lookup(curr_info->avail_out, v);
- l = find_leader(l);
+ assert(l);
if (l != v) {
- DB((dbg, LEVEL_2, "Replacing %+F by %+F\n", v, l));
- exchange(v, l);
+ elim_pair *p = obstack_alloc(env->obst, sizeof(*p));
+
+ p->old_node = v;
+ p->new_node = l;
+ p->next = env->pairs;
+ env->pairs = p;
+ }
+ }
+}
+
+/**
+ * Do all the recorded changes and optimize
+ * newly created Phi's.
+ */
+static void eliminate_nodes(elim_pair *pairs)
+{
+ elim_pair *p;
+
+ for (p = pairs; p != NULL; p = p->next) {
+ DB((dbg, LEVEL_2, "Replacing %+F by %+F\n", p->old_node, p->new_node));
+ /*
+ * PRE tends to create Phi(self, self, ... , x, self, self, ...)
+ * which we can optimize here
+ */
+ if (is_Phi(p->new_node)) {
+ int i;
+ ir_node *res = NULL;
+
+ for (i = get_irn_intra_arity(p->new_node) - 1; i >= 0; --i) {
+ ir_node *pred = get_irn_n(p->new_node, i);
+
+ if (pred != p->old_node) {
+ if (res) {
+ res = NULL;
+ break;
+ }
+ res = pred;
+ }
+ }
+ if (res)
+ p->new_node = res;
}
+ exchange(p->old_node, p->new_node);
}
}
+/*
+ * Argh: Endless loops cause problems, because the
+ * insert algorithm did not terminate. We get translated nodes that
+ * references the origin. These nodes are translated again and again...
+ *
+ * The current fix is to use post-dominance. This simple ignores
+ * endless loops, ie we cannot optimize them.
+ */
void do_gvn_pre(ir_graph *irg)
{
struct obstack obst;
pre_env a_env;
optimization_state_t state;
block_info *p;
- int iter = 0;
+ unsigned antic_iter, insert_iter;
+
+ assert(!"COMPLETELY BROKEN YET, DO NOT USE");
/* register a debug mask */
- dbg = firm_dbg_register("firm.opt.gvn_pre");
+ FIRM_DBG_REGISTER(dbg, "firm.opt.gvn_pre");
firm_dbg_set_mask(dbg, SET_LEVEL_2);
obstack_init(&obst);
a_env.obst = &obst;
+ a_env.trans_set = new_node_set();
a_env.list = NULL;
a_env.start_block = get_irg_start_block(irg);
a_env.end_block = get_irg_end_block(irg);
+ a_env.pairs = NULL;
/* Move Proj's into the same block as their args,
else we would assign the result to wrong blocks */
/* critical edges MUST be removed */
remove_critical_cf_edges(irg);
- /* we need dominator AND post dominator information */
+ /* we need dominator for Antic_out calculation */
if (get_irg_dom_state(irg) != dom_consistent)
compute_doms(irg);
if (get_irg_postdom_state(irg) != dom_consistent)
compute_postdoms(irg);
+ /* we get all nodes of a block by following outs */
if (get_irg_outs_state(irg) != outs_consistent)
compute_irg_outs(irg);
save_optimization_state(&state);
set_opt_global_cse(1);
+ DB((dbg, LEVEL_1, "Doing GVN-PRE for %e\n", get_irg_entity(irg)));
+ printf("Doing GVN-PRE for %s\n", get_entity_name(get_irg_entity(irg)));
+
/* allocate block info for all blocks */
irg_block_walk_graph(irg, NULL, alloc_blk_info, &a_env);
dom_tree_walk_irg(irg, compute_avail_top_down, NULL, &a_env);
/* compute the anticipated value sets for all blocks */
+ inc_irg_visited(irg);
+ antic_iter = 0;
+ a_env.first_iter = 1;
do {
- DB((dbg, LEVEL_1, "Antic_in Iteration %d starts ...\n", ++iter));
+ DB((dbg, LEVEL_1, "Antic_in Iteration %d starts ...\n", ++antic_iter));
a_env.changes = 0;
irg_block_walk_graph(irg, compute_antic, NULL, &a_env);
// postdom_tree_walk_irg(irg, compute_antic, NULL, &a_env);
+ a_env.first_iter = 0;
DB((dbg, LEVEL_1, "------------------------\n"));
} while (a_env.changes != 0);
/* compute redundant expressions */
- iter = 0;
+ insert_iter = 0;
do {
- DB((dbg, LEVEL_1, "Insert Iteration %d starts ...\n", ++iter));
+ DB((dbg, LEVEL_1, "Insert Iteration %d starts ...\n", ++insert_iter));
a_env.changes = 0;
dom_tree_walk_irg(irg, insert_nodes, NULL, &a_env);
DB((dbg, LEVEL_1, "------------------------\n"));
} while (a_env.changes != 0);
/* last step: eliminate nodes */
- dom_tree_walk_irg(irg, eliminate_nodes, NULL, &a_env);
+ dom_tree_walk_irg(irg, collect_elim_pairs, NULL, &a_env);
+ eliminate_nodes(a_env.pairs);
restore_optimization_state(&state);
/* clean up: delete all sets */
for (p = a_env.list; p != NULL; p = p->next) {
if (p->antic_in)
- del_pset(p->antic_in);
+ del_node_set(p->antic_in);
if (p->avail_out)
- del_pset(p->avail_out);
+ del_value_set(p->avail_out);
if (p->nodes)
- del_pset(p->nodes);
+ del_node_set(p->nodes);
+ if (p->new_set)
+ del_value_set(p->new_set);
}
+ del_node_set(a_env.trans_set);
obstack_free(&obst, NULL);
+ set_irg_pinned(irg, op_pin_state_pinned);
+
+ if (a_env.pairs) {
+ set_irg_outs_inconsistent(irg);
+ set_irg_loopinfo_inconsistent(irg);
+ }
} /* do_gvn_pre */
projects / libfirm / blobdiff