X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbecopyopt.c;h=8b0f6d000282c7e20bb6fb22fce923370fe61552;hb=8544304305897e5f2b5752fc243fd45c4f95a38c;hp=85a3334faafcbb41da3e24ff9739426079487ed0;hpb=ad8d083988ca94d6d0370f172533112f592f62df;p=libfirm

diff --git a/ir/be/becopyopt.c b/ir/be/becopyopt.c
index 85a3334fa..8b0f6d000 100644
--- a/ir/be/becopyopt.c
+++ b/ir/be/becopyopt.c
@@ -1,113 +1,639 @@
 /**
- * @author Daniel Grund
- * @date 12.04.2005
+ * Author:      Daniel Grund
+ * Date:		12.04.2005
+ * Copyright:   (c) Universitaet Karlsruhe
+ * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
  */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#ifdef HAVE_ALLOCA_H
+#include <alloca.h>
+#endif
+#ifdef HAVE_MALLOC_H
+#include <malloc.h>
+#endif
 
-#include "becopyopt.h"
+#include "xmalloc.h"
+#include "debug.h"
+#include "pmap.h"
+#include "irgraph.h"
+#include "irgwalk.h"
+#include "irprog.h"
+#include "irloop_t.h"
+#include "iredges_t.h"
+#include "phiclass.h"
 
-#define DEBUG_LVL 0 //SET_LEVEL_1
-static firm_dbg_module_t *dbg = NULL;
+#include "bearch.h"
+#include "beutil.h"
+#include "beifg_t.h"
+#include "becopyopt_t.h"
+#include "becopystat.h"
 
-//TODO external things
-#define is_optimizable(irn) (is_Phi(irn) || 0)
+
+#undef QUICK_AND_DIRTY_HACK
+
+/******************************************************************************
+    _____                           _
+   / ____|                         | |
+  | |  __  ___ _ __   ___ _ __ __ _| |
+  | | |_ |/ _ \ '_ \ / _ \ '__/ _` | |
+  | |__| |  __/ | | |  __/ | | (_| | |
+   \_____|\___|_| |_|\___|_|  \__,_|_|
+
+ ******************************************************************************/
+
+DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
+
+void be_copy_opt_init(void) {
+}
+
+copy_opt_t *new_copy_opt(be_chordal_env_t *chordal_env, int (*get_costs)(ir_node*, ir_node*, int)) {
+	const char *s1, *s2, *s3;
+	int len;
+	copy_opt_t *co;
+
+	FIRM_DBG_REGISTER(dbg, "ir.be.copyopt");
+
+	co = xcalloc(1, sizeof(*co));
+	co->cenv      = chordal_env;
+	co->aenv      = chordal_env->birg->main_env->arch_env;
+	co->irg       = chordal_env->irg;
+	co->cls       = chordal_env->cls;
+	co->get_costs = get_costs;
+
+	s1 = get_irp_prog_name();
+	s2 = get_entity_name(get_irg_entity(co->irg));
+	s3 = chordal_env->cls->name;
+	len = strlen(s1) + strlen(s2) + strlen(s3) + 5;
+	co->name = xmalloc(len);
+	snprintf(co->name, len, "%s__%s__%s", s1, s2, s3);
+
+	return co;
+}
+
+void free_copy_opt(copy_opt_t *co) {
+	xfree(co->name);
+	free(co);
+}
+
+int co_is_optimizable_root(const copy_opt_t *co, ir_node *irn) {
+	arch_register_req_t req;
+	const arch_register_t *reg;
+
+	if (arch_irn_is(co->aenv, irn, ignore))
+		return 0;
+
+	reg = arch_get_irn_register(co->aenv, irn);
+	if (arch_register_type_is(reg, ignore))
+		return 0;
+
+	if (is_Reg_Phi(irn) || is_Perm_Proj(co->aenv, irn) || is_2addr_code(co->aenv, irn, &req))
+		return 1;
+
+	return 0;
+}
+
+int co_is_optimizable_arg(const copy_opt_t *co, ir_node *irn) {
+	const ir_edge_t *edge;
+	const arch_register_t *reg;
+
+	assert(0 && "Is buggy and obsolete. Do not use");
+
+	if (arch_irn_is(co->aenv, irn, ignore))
+		return 0;
+
+	reg = arch_get_irn_register(co->aenv, irn);
+	if (arch_register_type_is(reg, ignore))
+		return 0;
+
+	foreach_out_edge(irn, edge) {
+		ir_node *n = edge->src;
+
+		if (!nodes_interfere(co->cenv, irn, n) || irn == n) {
+			arch_register_req_t req;
+			arch_get_register_req(co->aenv, &req, n, -1);
+
+			if(is_Reg_Phi(n) ||
+			   is_Perm(co->aenv, n) ||
+			   (arch_register_req_is(&req, should_be_same) && req.other_same == irn)
+			  )
+				return 1;
+		}
+	}
+
+	return 0;
+}
+
+int co_get_costs_loop_depth(ir_node *root, ir_node* arg, int pos) {
+	int cost = 0;
+	ir_loop *loop;
+	ir_node *root_block = get_nodes_block(root);
+
+	if (is_Phi(root)) {
+		/* for phis the copies are placed in the corresponding pred-block */
+		loop = get_irn_loop(get_Block_cfgpred_block(root_block, pos));
+	} else {
+		/* a perm places the copy in the same block as it resides */
+		loop = get_irn_loop(root_block);
+	}
+	if (loop) {
+		int d = get_loop_depth(loop);
+		cost = d*d;
+	}
+	return cost+1;
+}
+
+int co_get_costs_all_one(ir_node *root, ir_node* arg, int pos) {
+	return 1;
+}
+
+/******************************************************************************
+   ____        _   _    _       _ _          _____ _
+  / __ \      | | | |  | |     (_) |        / ____| |
+ | |  | |_ __ | |_| |  | |_ __  _| |_ ___  | (___ | |_ ___  _ __ __ _  __ _  ___
+ | |  | | '_ \| __| |  | | '_ \| | __/ __|  \___ \| __/ _ \| '__/ _` |/ _` |/ _ \
+ | |__| | |_) | |_| |__| | | | | | |_\__ \  ____) | || (_) | | | (_| | (_| |  __/
+  \____/| .__/ \__|\____/|_| |_|_|\__|___/ |_____/ \__\___/|_|  \__,_|\__, |\___|
+        | |                                                            __/ |
+        |_|                                                           |___/
+ ******************************************************************************/
 
 /**
- * Builds an optimization unit for a given optimizable irn (root).
- * This opt-unit is inserted in the main structure co.
- * If an arg of root itself is optimizable process this arg before with a
- * recursive call. For handling this situation and loops co->root is used
- * to remember all roots.
+ * Determines a maximum weighted independent set with respect to
+ * the interference and conflict edges of all nodes in a qnode.
  */
-static void co_append_unit(copy_opt_t *co, const ir_node *root) {
-	int i, arity;
+static int ou_max_ind_set_costs(unit_t *ou) {
+	be_chordal_env_t *chordal_env = ou->co->cenv;
+	ir_node **safe, **unsafe;
+	int i, o, safe_count, safe_costs, unsafe_count, *unsafe_costs;
+	bitset_t *curr;
+	int max, pos, curr_weight, best_weight = 0;
+
+	/* assign the nodes into two groups.
+	 * safe: node has no interference, hence it is in every max stable set.
+	 * unsafe: node has an interference
+	 */
+	safe = alloca((ou->node_count-1) * sizeof(*safe));
+	safe_costs = 0;
+	safe_count = 0;
+	unsafe = alloca((ou->node_count-1) * sizeof(*unsafe));
+	unsafe_costs = alloca((ou->node_count-1) * sizeof(*unsafe_costs));
+	unsafe_count = 0;
+	for(i=1; i<ou->node_count; ++i) {
+		int is_safe = 1;
+		for(o=1; o<ou->node_count; ++o) {
+			if (i==o)
+				continue;
+			if (nodes_interfere(chordal_env, ou->nodes[i], ou->nodes[o])) {
+				unsafe_costs[unsafe_count] = ou->costs[i];
+				unsafe[unsafe_count] = ou->nodes[i];
+				++unsafe_count;
+				is_safe = 0;
+				break;
+			}
+		}
+		if (is_safe) {
+			safe_costs += ou->costs[i];
+			safe[safe_count++] = ou->nodes[i];
+		}
+	}
+
+
+	/* now compute the best set out of the unsafe nodes*/
+	if (unsafe_count > MIS_HEUR_TRIGGER) {
+		bitset_t *best = bitset_alloca(unsafe_count);
+		/* Heuristik: Greedy trial and error form index 0 to unsafe_count-1 */
+		for (i=0; i<unsafe_count; ++i) {
+			bitset_set(best, i);
+			/* check if it is a stable set */
+			for (o=bitset_next_set(best, 0); o!=-1 && o<i; o=bitset_next_set(best, o+1))
+				if (nodes_interfere(chordal_env, unsafe[i], unsafe[o])) {
+					bitset_clear(best, i); /* clear the bit and try next one */
+					break;
+				}
+		}
+		/* compute the weight */
+		bitset_foreach(best, pos)
+			best_weight += unsafe_costs[pos];
+	} else {
+		/* Exact Algorithm: Brute force */
+		curr = bitset_alloca(unsafe_count);
+		bitset_set_all(curr);
+		while ((max = bitset_popcnt(curr)) != 0) {
+			/* check if curr is a stable set */
+			for (i=bitset_next_set(curr, 0); i!=-1; i=bitset_next_set(curr, i+1))
+				for (o=bitset_next_set(curr, i+1); o!=-1; o=bitset_next_set(curr, o+1)) /* !!!!! difference to qnode_max_ind_set(): NOT (curr, i) */
+						if (nodes_interfere(chordal_env, unsafe[i], unsafe[o]))
+							goto no_stable_set;
+
+			/* if we arrive here, we have a stable set */
+			/* compute the weigth of the stable set*/
+			curr_weight = 0;
+			bitset_foreach(curr, pos)
+				curr_weight += unsafe_costs[pos];
+
+			/* any better ? */
+			if (curr_weight > best_weight) {
+				best_weight = curr_weight;
+			}
+
+	no_stable_set:
+			bitset_minus1(curr);
+		}
+	}
+
+	return safe_costs+best_weight;
+}
+
+static void co_collect_units(ir_node *irn, void *env) {
+	copy_opt_t *co = env;
 	unit_t *unit;
-	DBG((dbg, LEVEL_1, "\t  Root: %n\n", root));
-	/* check if we encountered this root earlier */
-	if (pset_find_ptr(co->roots, root))
+	arch_register_req_t req;
+
+	if (!is_curr_reg_class(co, irn))
+		return;
+	if (!co_is_optimizable_root(co, irn))
 		return;
-	pset_insert_ptr(co->roots, root);
 
-	/* init unit */
-	arity = get_irn_arity(root);
-	unit = malloc(sizeof(*unit));
-	unit->interf = 0;
+	/* Init a new unit */
+	unit = xcalloc(1, sizeof(*unit));
+	unit->co = co;
 	unit->node_count = 1;
-	unit->nodes = malloc((arity+1) * sizeof(*unit->nodes));
-	unit->nodes[0] = root;
 	INIT_LIST_HEAD(&unit->queue);
 
-	/* check all args */
-	for (i=0; i<arity; ++i) {
-		ir_node *arg = get_irn_n(root, i);
-		if (arg != root) {
-			if (!values_interfere(root, arg)) {
-				DBG((dbg, LEVEL_1, "\t  Member: %n\n", arg));
-				if (is_optimizable(arg))
-					co_append_unit(co, arg);
-				unit->nodes[unit->node_count++] = arg;
-			} else
-				unit->interf++;
+	/* Phi with some/all of its arguments */
+	if (is_Reg_Phi(irn)) {
+		int i, arity;
+
+		/* init */
+		arity = get_irn_arity(irn);
+		unit->nodes = xmalloc((arity+1) * sizeof(*unit->nodes));
+		unit->costs = xmalloc((arity+1) * sizeof(*unit->costs));
+		unit->nodes[0] = irn;
+
+		/* fill */
+		for (i=0; i<arity; ++i) {
+			int o, arg_pos;
+			ir_node *arg = get_irn_n(irn, i);
+
+			assert(is_curr_reg_class(co, arg) && "Argument not in same register class.");
+			if (arg == irn)
+				continue;
+			if (nodes_interfere(co->cenv, irn, arg)) {
+				unit->inevitable_costs += co->get_costs(irn, arg, i);
+				continue;
+			}
+
+			/* Else insert the argument of the phi to the members of this ou */
+			DBG((dbg, LEVEL_1, "\t   Member: %+F\n", arg));
+
+			/* Check if arg has occurred at a prior position in the arg/list */
+			arg_pos = 0;
+			for (o=0; o<unit->node_count; ++o)
+				if (unit->nodes[o] == arg) {
+					arg_pos = o;
+					break;
+				}
+
+			if (!arg_pos) { /* a new argument */
+				/* insert node, set costs */
+				unit->nodes[unit->node_count] = arg;
+				unit->costs[unit->node_count] = co->get_costs(irn, arg, i);
+				unit->node_count++;
+			} else { /* arg has occured before in same phi */
+				/* increase costs for existing arg */
+				unit->costs[arg_pos] += co->get_costs(irn, arg, i);
+			}
 		}
-	}
+		unit->nodes = xrealloc(unit->nodes, unit->node_count * sizeof(*unit->nodes));
+		unit->costs = xrealloc(unit->costs, unit->node_count * sizeof(*unit->costs));
+	} else
+
+	/* Proj of a perm with corresponding arg */
+	if (is_Perm_Proj(co->aenv, irn)) {
+		assert(!nodes_interfere(co->cenv, irn, get_Perm_src(irn)));
+		unit->nodes = xmalloc(2 * sizeof(*unit->nodes));
+		unit->costs = xmalloc(2 * sizeof(*unit->costs));
+		unit->node_count = 2;
+		unit->nodes[0] = irn;
+		unit->nodes[1] = get_Perm_src(irn);
+		unit->costs[1] = co->get_costs(irn, unit->nodes[1], -1);
+	} else
+
+	/* Src == Tgt of a 2-addr-code instruction */
+	if (is_2addr_code(co->aenv, irn, &req)) {
+		ir_node *other = req.other_same;
+		if (!nodes_interfere(co->cenv, irn, other)) {
+			unit->nodes = xmalloc(2 * sizeof(*unit->nodes));
+			unit->costs = xmalloc(2 * sizeof(*unit->costs));
+			unit->node_count = 2;
+			unit->nodes[0] = irn;
+			unit->nodes[1] = other;
+			unit->costs[1] = co->get_costs(irn, other, -1);
+		}
+	} else
+		assert(0 && "This is not an optimizable node!");
 
+	/* Insert the new unit at a position according to its costs */
 	if (unit->node_count > 1) {
-		unit->nodes = realloc(unit->nodes, unit->node_count * sizeof(*unit->nodes));
-		list_add_tail(&unit->units, &co->units);
+		int i;
+		struct list_head *tmp;
+
+		/* Determine the maximum costs this unit can cause: all_nodes_cost */
+		for(i=1; i<unit->node_count; ++i) {
+			unit->sort_key = MAX(unit->sort_key, unit->costs[i]);
+			unit->all_nodes_costs += unit->costs[i];
+		}
+
+		/* Determine the minimal costs this unit will cause: min_nodes_costs */
+		unit->min_nodes_costs += unit->all_nodes_costs - ou_max_ind_set_costs(unit);
+		/* Insert the new ou according to its sort_key */
+		tmp = &co->units;
+		while (tmp->next != &co->units && list_entry_units(tmp->next)->sort_key > unit->sort_key)
+			tmp = tmp->next;
+		list_add(&unit->units, tmp);
 	} else {
-		free(unit->nodes);
 		free(unit);
 	}
 }
 
-static void co_collect_in_block(ir_node *block, void *env) {
-	copy_opt_t *co = env;
-	struct list_head *head = &get_ra_block_info(block)->border_head;
-	border_t *curr;
+#ifdef QUICK_AND_DIRTY_HACK
 
-	list_for_each_entry_reverse(border_t, curr, head, list)
-		if (curr->is_def && curr->is_real && is_optimizable(curr->irn))
-			co_append_unit(co, curr->irn);
-}
+static int compare_ous(const void *k1, const void *k2) {
+	const unit_t *u1 = *((const unit_t **) k1);
+	const unit_t *u2 = *((const unit_t **) k2);
+	int i, o, u1_has_constr, u2_has_constr;
+	arch_register_req_t req;
+	const arch_env_t *aenv = u1->co->aenv;
+
+	/* Units with constraints come first */
+	u1_has_constr = 0;
+	for (i=0; i<u1->node_count; ++i) {
+		arch_get_register_req(aenv, &req, u1->nodes[i], -1);
+		if (arch_register_req_is(&req, limited)) {
+			u1_has_constr = 1;
+			break;
+		}
+	}
+
+	u2_has_constr = 0;
+	for (i=0; i<u2->node_count; ++i) {
+		arch_get_register_req(aenv, &req, u2->nodes[i], -1);
+		if (arch_register_req_is(&req, limited)) {
+			u2_has_constr = 1;
+			break;
+		}
+	}
+
+	if (u1_has_constr != u2_has_constr)
+		return u2_has_constr - u1_has_constr;
+
+	/* Now check, whether the two units are connected */
+#if 0
+	for (i=0; i<u1->node_count; ++i)
+		for (o=0; o<u2->node_count; ++o)
+			if (u1->nodes[i] == u2->nodes[o])
+				return 0;
+#endif
+
+	/* After all, the sort key decides. Greater keys come first. */
+	return u2->sort_key - u1->sort_key;
 
-static void co_collect_units(copy_opt_t *co) {
-	DBG((dbg, LEVEL_1, "\tCollecting optimization units\n"));
-	co->roots = pset_new_ptr(64);
-	dom_tree_walk_irg(co->irg, co_collect_in_block, NULL, co);
-	del_pset(co->roots);
 }
 
-copy_opt_t *new_copy_opt(ir_graph *irg) {
-	dbg = firm_dbg_register("ir.be.copyopt");
-	firm_dbg_set_mask(dbg, DEBUG_LVL);
+/**
+ * Sort the ou's according to constraints and their sort_key
+ */
+static void co_sort_units(copy_opt_t *co) {
+	int i, count = 0, costs;
+	unit_t *ou, **ous;
+
+	/* get the number of ous, remove them form the list and fill the array */
+	list_for_each_entry(unit_t, ou, &co->units, units)
+		count++;
+	ous = alloca(count * sizeof(*ous));
+
+	costs = co_get_max_copy_costs(co);
+
+	i = 0;
+	list_for_each_entry(unit_t, ou, &co->units, units)
+		ous[i++] = ou;
 
-	copy_opt_t *co = calloc(1, sizeof(*co));
-	co->irg = irg;
 	INIT_LIST_HEAD(&co->units);
-	co_collect_units(co);
-	return co;
+
+	assert(count == i && list_empty(&co->units));
+
+	for (i=0; i<count; ++i)
+		ir_printf("%+F\n", ous[i]->nodes[0]);
+
+	qsort(ous, count, sizeof(*ous), compare_ous);
+
+	ir_printf("\n\n");
+	for (i=0; i<count; ++i)
+		ir_printf("%+F\n", ous[i]->nodes[0]);
+
+	/* reinsert into list in correct order */
+	for (i=0; i<count; ++i)
+		list_add_tail(&ous[i]->units, &co->units);
+
+	assert(costs == co_get_max_copy_costs(co));
 }
+#endif
 
-void free_copy_opt(copy_opt_t *co) {
+void co_build_ou_structure(copy_opt_t *co) {
+	DBG((dbg, LEVEL_1, "\tCollecting optimization units\n"));
+	INIT_LIST_HEAD(&co->units);
+	irg_walk_graph(co->irg, co_collect_units, NULL, co);
+#ifdef QUICK_AND_DIRTY_HACK
+	co_sort_units(co);
+#endif
+}
+
+void co_free_ou_structure(copy_opt_t *co) {
 	unit_t *curr, *tmp;
+	ASSERT_OU_AVAIL(co);
 	list_for_each_entry_safe(unit_t, curr, tmp, &co->units, units) {
-		free(curr->nodes);
-		free(curr);
+		xfree(curr->nodes);
+		xfree(curr->costs);
+		xfree(curr);
+	}
+	co->units.next = NULL;
+}
+
+/* co_solve_heuristic() is implemented in becopyheur.c */
+
+int co_get_max_copy_costs(const copy_opt_t *co) {
+	int i, res = 0;
+	unit_t *curr;
+
+	ASSERT_OU_AVAIL(co);
+
+	list_for_each_entry(unit_t, curr, &co->units, units) {
+		res += curr->inevitable_costs;
+		for (i=1; i<curr->node_count; ++i)
+			res += curr->costs[i];
 	}
+	return res;
 }
 
-int co_get_lower_bound(copy_opt_t *co) {
-	//TODO Think if copy counting is this easy!
+int co_get_inevit_copy_costs(const copy_opt_t *co) {
 	int res = 0;
 	unit_t *curr;
+
+	ASSERT_OU_AVAIL(co);
+
 	list_for_each_entry(unit_t, curr, &co->units, units)
-		res += curr->interf + curr->node_count - curr->mis_size;
+		res += curr->inevitable_costs;
+	return res;
+}
+
+int co_get_copy_costs(const copy_opt_t *co) {
+	int i, res = 0;
+	unit_t *curr;
+
+	ASSERT_OU_AVAIL(co);
+
+	list_for_each_entry(unit_t, curr, &co->units, units) {
+		int root_col = get_irn_col(co, curr->nodes[0]);
+		DBG((dbg, LEVEL_1, "  %3d costs for root %+F color %d\n", curr->inevitable_costs, curr->nodes[0], root_col));
+		res += curr->inevitable_costs;
+		for (i=1; i<curr->node_count; ++i) {
+			int arg_col = get_irn_col(co, curr->nodes[i]);
+			if (root_col != arg_col) {
+				DBG((dbg, LEVEL_1, "  %3d for arg %+F color %d\n", curr->costs[i], curr->nodes[i], arg_col));
+				res += curr->costs[i];
+			}
+		}
+	}
 	return res;
 }
 
-int co_get_interferer_count(copy_opt_t *co) {
+int co_get_lower_bound(const copy_opt_t *co) {
 	int res = 0;
 	unit_t *curr;
+
+	ASSERT_OU_AVAIL(co);
+
 	list_for_each_entry(unit_t, curr, &co->units, units)
-		res += curr->interf;
+		res += curr->inevitable_costs + curr->min_nodes_costs;
 	return res;
 }
+
+/******************************************************************************
+   _____                 _        _____ _
+  / ____|               | |      / ____| |
+ | |  __ _ __ __ _ _ __ | |__   | (___ | |_ ___  _ __ __ _  __ _  ___
+ | | |_ | '__/ _` | '_ \| '_ \   \___ \| __/ _ \| '__/ _` |/ _` |/ _ \
+ | |__| | | | (_| | |_) | | | |  ____) | || (_) | | | (_| | (_| |  __/
+  \_____|_|  \__,_| .__/|_| |_| |_____/ \__\___/|_|  \__,_|\__, |\___|
+                  | |                                       __/ |
+                  |_|                                      |___/
+ ******************************************************************************/
+
+static int compare_affinity_node_t(const void *k1, const void *k2, size_t size) {
+	const affinity_node_t *n1 = k1;
+	const affinity_node_t *n2 = k2;
+
+	return (n1->irn != n2->irn);
+}
+
+static void add_edge(copy_opt_t *co, ir_node *n1, ir_node *n2, int costs) {
+	affinity_node_t new_node, *node;
+	neighb_t new_nbr, *nbr;
+	int allocnew;
+
+	new_node.irn        = n1;
+	new_node.degree     = 0;
+	new_node.neighbours = NULL;
+	node = set_insert(co->nodes, &new_node, sizeof(new_node), HASH_PTR(new_node.irn));
+
+	allocnew = 1;
+	for (nbr = node->neighbours; nbr; nbr = nbr->next)
+		if (nbr->irn == n2) {
+			allocnew = 0;
+			break;
+		}
+
+	/* if we did not find n2 in n1's neighbourhood insert it */
+	if (allocnew) {
+		obstack_grow(&co->obst, &new_nbr, sizeof(new_nbr));
+		nbr = obstack_finish(&co->obst);
+		nbr->irn   = n2;
+		nbr->costs = 0;
+		nbr->next  = node->neighbours;
+		node->neighbours = nbr;
+		node->degree++;
+	}
+
+	/* now nbr points to n1's neighbour-entry of n2 */
+	nbr->costs += costs;
+}
+
+static INLINE void add_edges(copy_opt_t *co, ir_node *n1, ir_node *n2, int costs) {
+	if (! be_ifg_connected(co->cenv->ifg, n1, n2)) {
+		add_edge(co, n1, n2, costs);
+		add_edge(co, n2, n1, costs);
+	}
+}
+
+static void build_graph_walker(ir_node *irn, void *env) {
+	copy_opt_t *co = env;
+	int pos, max;
+	arch_register_req_t req;
+	const arch_register_t *reg;
+
+	if (!is_curr_reg_class(co, irn) || arch_irn_is(co->aenv, irn, ignore))
+		return;
+
+	reg = arch_get_irn_register(co->aenv, irn);
+	if (arch_register_type_is(reg, ignore))
+		return;
+
+	/* Phis */
+	if (is_Reg_Phi(irn))
+		for (pos=0, max=get_irn_arity(irn); pos<max; ++pos) {
+			ir_node *arg = get_irn_n(irn, pos);
+			add_edges(co, irn, arg, co->get_costs(irn, arg, pos));
+		}
+
+	/* Perms */
+	else if (is_Perm_Proj(co->aenv, irn)) {
+		ir_node *arg = get_Perm_src(irn);
+		add_edges(co, irn, arg, co->get_costs(irn, arg, 0));
+	}
+
+	/* 2-address code */
+	else if (is_2addr_code(co->aenv, irn, &req))
+		add_edges(co, irn, req.other_same, co->get_costs(irn, req.other_same, 0));
+}
+
+void co_build_graph_structure(copy_opt_t *co) {
+	obstack_init(&co->obst);
+	co->nodes = new_set(compare_affinity_node_t, 32);
+
+	irg_walk_graph(co->irg, build_graph_walker, NULL, co);
+}
+
+void co_free_graph_structure(copy_opt_t *co) {
+	ASSERT_GS_AVAIL(co);
+
+	del_set(co->nodes);
+	obstack_free(&co->obst, NULL);
+	co->nodes = NULL;
+}
+
+/* co_solve_ilp1() co_solve_ilp2() are implemented in becopyilpX.c */
+
+int co_gs_is_optimizable(copy_opt_t *co, ir_node *irn) {
+	affinity_node_t new_node, *n;
+
+	ASSERT_GS_AVAIL(co);
+
+	new_node.irn = irn;
+	n = set_find(co->nodes, &new_node, sizeof(new_node), HASH_PTR(new_node.irn));
+	if (n) {
+		return (n->degree > 0);
+	} else
+		return 0;
+}