X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbelistsched.c;h=cf31ea45ec0c76fcad5d13d876d7f43ac6ff8d8b;hb=1872920c09708b361d06c0dc9f4c1fd0a03544f5;hp=78ec313355f4d06aa5260aad7af8fa4c9f9ae303;hpb=08f9ccb62f9fc4250a0721a3ae38b6574ada8c1b;p=libfirm

diff --git a/ir/be/belistsched.c b/ir/be/belistsched.c
index 78ec31335..cf31ea45e 100644
--- a/ir/be/belistsched.c
+++ b/ir/be/belistsched.c
@@ -1,11 +1,29 @@
-/**
- * Scheduling algorithms.
- * Just a simple list scheduling algorithm is here.
- * @date   20.10.2004
- * @author Sebastian Hack
- * @cvs-id $Id$
+/*
+ * 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       Primitive list scheduling with different node selectors.
+ * @author      Sebastian Hack
+ * @date        20.10.2004
+ * @version     $Id$
+ */
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
@@ -32,26 +50,90 @@
 #include "debug.h"
 #include "irtools.h"
 
+#include "bemodule.h"
 #include "besched_t.h"
 #include "beutil.h"
 #include "belive_t.h"
 #include "belistsched.h"
 #include "beschedmris.h"
-#include "bearch.h"
+#include "beschedrss.h"
+#include "bearch_t.h"
 #include "bestat.h"
+#include "beirg_t.h"
+
+#include "lc_opts.h"
+#include "lc_opts_enum.h"
+
+DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL);
+
+#define BE_SCHED_NODE(irn) (be_is_Keep(irn) || be_is_CopyKeep(irn) || be_is_RegParams(irn))
+
+enum {
+	BE_SCHED_SELECT_TRIVIAL,
+	BE_SCHED_SELECT_REGPRESS,
+	BE_SCHED_SELECT_MUCHNIK,
+	BE_SCHED_SELECT_HEUR,
+	BE_SCHED_SELECT_HMUCHNIK,
+	BE_SCHED_SELECT_RANDOM,
+	BE_SCHED_SELECT_NORMAL,
+};
+
+enum {
+	BE_SCHED_PREP_NONE = 0,
+	BE_SCHED_PREP_MRIS = 2,
+	BE_SCHED_PREP_RSS  = 3
+};
+
+typedef struct _list_sched_options_t {
+	int select;  /**< the node selector */
+	int prep;    /**< schedule preparation */
+} list_sched_options_t;
+
+static list_sched_options_t list_sched_options = {
+	BE_SCHED_SELECT_HEUR,     /* mueller heuristic selector */
+	BE_SCHED_PREP_NONE,       /* no scheduling preparation */
+};
+
+/* schedule selector options. */
+static const lc_opt_enum_int_items_t sched_select_items[] = {
+	{ "trivial",  BE_SCHED_SELECT_TRIVIAL  },
+	{ "random",   BE_SCHED_SELECT_RANDOM   },
+	{ "regpress", BE_SCHED_SELECT_REGPRESS },
+	{ "normal",   BE_SCHED_SELECT_NORMAL   },
+	{ "muchnik",  BE_SCHED_SELECT_MUCHNIK  },
+	{ "heur",     BE_SCHED_SELECT_HEUR     },
+	{ "hmuchnik", BE_SCHED_SELECT_HMUCHNIK },
+	{ NULL,       0 }
+};
+
+/* schedule preparation options. */
+static const lc_opt_enum_int_items_t sched_prep_items[] = {
+	{ "none", BE_SCHED_PREP_NONE },
+	{ "mris", BE_SCHED_PREP_MRIS },
+	{ "rss",  BE_SCHED_PREP_RSS  },
+	{ NULL,   0 }
+};
+
+static lc_opt_enum_int_var_t sched_select_var = {
+	&list_sched_options.select, sched_select_items
+};
+
+static lc_opt_enum_int_var_t sched_prep_var = {
+	&list_sched_options.prep, sched_prep_items
+};
+
+static const lc_opt_table_entry_t list_sched_option_table[] = {
+	LC_OPT_ENT_ENUM_PTR("prep",   "schedule preparation",   &sched_prep_var),
+	LC_OPT_ENT_ENUM_PTR("select", "node selector",          &sched_select_var),
+	LC_OPT_LAST
+};
 
 /**
  * All scheduling info needed per node.
  */
 typedef struct _sched_irn_t {
-	sched_timestep_t delay;      /**< The delay for this node if already calculated, else 0. */
-	sched_timestep_t etime;      /**< The earliest time of this node. */
-	unsigned num_user;           /**< The number real users (mode datab) of this node */
 	unsigned num_not_sched_user; /**< The number of not yet scheduled users of this node */
-	int      reg_diff;           /**< The difference of num(out registers) - num(in registers) */
-	int      preorder;           /**< The pre-order position */
 	unsigned already_sched : 1;  /**< Set if this node is already scheduled */
-	unsigned is_root       : 1;  /**< is a root node of a block */
 } sched_irn_t;
 
 /**
@@ -63,523 +145,62 @@ typedef struct _sched_env_t {
 	const arch_env_t *arch_env;                 /**< The architecture environment. */
 	const ir_graph *irg;                        /**< The graph to schedule. */
 	void *selector_env;                         /**< A pointer to give to the selector. */
-	unsigned use_heuristic : 1;                 /**< Use internal heuristic or backend selector */
 } sched_env_t;
 
-#if 0
-/*
- * Ugly global variable for the compare function
- * since qsort(3) does not pass an extra pointer.
- */
-static ir_node *curr_bl = NULL;
-
-static int cmp_usage(const void *a, const void *b)
-{
-	struct trivial_sched_env *env;
-	const ir_node *p = a;
-	const ir_node *q = b;
-	int res = 0;
-
-	res = is_live_end(env->curr_bl, a) - is_live_end(env->curr_bl, b);
-
-	/*
-	 * One of them is live at the end of the block.
-	 * Then, that one shall be scheduled at after the other
-	 */
-	if(res != 0)
-		return res;
-
-
-	return res;
-}
-#endif
-
-/**
- * The trivial selector:
- * Just assure that branches are executed last, otherwise select
- * the first node ready.
- */
-static ir_node *trivial_select(void *block_env, nodeset *ready_set)
-{
-	const arch_env_t *arch_env = block_env;
-	ir_node *irn = NULL;
-
-	/* assure that branches and constants are executed last */
-	for (irn = nodeset_first(ready_set); irn; irn = nodeset_next(ready_set)) {
-		if (! arch_irn_class_is(arch_env, irn, branch)) {
-			nodeset_break(ready_set);
-			return irn;
-		}
-	}
-
-
-	/* at last: schedule branches */
-	irn = nodeset_first(ready_set);
-	nodeset_break(ready_set);
-
-	return irn;
-}
-
-static void *trivial_init_graph(const list_sched_selector_t *vtab, const arch_env_t *arch_env, ir_graph *irg)
-{
-	return (void *) arch_env;
-}
-
-static void *trivial_init_block(void *graph_env, ir_node *bl)
-{
-	return graph_env;
-}
-
-static INLINE int must_appear_in_schedule(const list_sched_selector_t *sel, void *block_env, const ir_node *irn)
-{
-	int res = -1;
-
-	if(sel->to_appear_in_schedule)
-		res = sel->to_appear_in_schedule(block_env, irn);
-
-	return res >= 0 ? res : (to_appear_in_schedule(irn) || be_is_Keep(irn) || be_is_RegParams(irn));
-}
-
-static const list_sched_selector_t trivial_selector_struct = {
-	trivial_init_graph,
-	trivial_init_block,
-	trivial_select,
-	NULL,                /* to_appear_in_schedule */
-	NULL,                /* exectime */
-	NULL,                /* latency */
-	NULL,                /* finish_block */
-	NULL                 /* finish_graph */
-};
-
-const list_sched_selector_t *trivial_selector = &trivial_selector_struct;
-
-typedef struct _usage_stats_t {
-	ir_node *irn;
-	struct _usage_stats_t *next;
-	int max_hops;
-	int uses_in_block;      /**< Number of uses inside the current block. */
-	int already_consumed;   /**< Number of insns using this value already
-							  scheduled. */
-} usage_stats_t;
-
-typedef struct {
-	const list_sched_selector_t *vtab;
-	const arch_env_t *arch_env;
-} reg_pressure_main_env_t;
-
-typedef struct {
-	struct obstack obst;
-	const reg_pressure_main_env_t *main_env;
-	usage_stats_t *root;
-	nodeset *already_scheduled;
-} reg_pressure_selector_env_t;
-
-static INLINE usage_stats_t *get_or_set_usage_stats(reg_pressure_selector_env_t *env, ir_node *irn)
-{
-	usage_stats_t *us = get_irn_link(irn);
-
-	if(!us) {
-		us                   = obstack_alloc(&env->obst, sizeof(us[0]));
-		us->irn              = irn;
-		us->already_consumed = 0;
-		us->max_hops         = INT_MAX;
-		us->next             = env->root;
-		env->root            = us;
-		set_irn_link(irn, us);
-	}
-
-	return us;
-}
-
-static INLINE usage_stats_t *get_usage_stats(ir_node *irn)
-{
-	usage_stats_t *us = get_irn_link(irn);
-	assert(us && "This node must have usage stats");
-	return us;
-}
-
-static int max_hops_walker(reg_pressure_selector_env_t *env, ir_node *irn, ir_node *curr_bl, int depth, unsigned visited_nr)
-{
-	ir_node *bl = get_nodes_block(irn);
-	/*
-	 * If the reached node is not in the block desired,
-	 * return the value passed for this situation.
-	 */
-	if(get_nodes_block(irn) != bl)
-		return block_dominates(bl, curr_bl) ? 0 : INT_MAX;
-
-	/*
-	 * If the node is in the current block but not
-	 * yet scheduled, we keep on searching from that node.
-	 */
-	if(!nodeset_find(env->already_scheduled, irn)) {
-		int i, n;
-		int res = 0;
-		for(i = 0, n = get_irn_arity(irn); i < n; ++i) {
-			ir_node *operand = get_irn_n(irn, i);
-
-			if(get_irn_visited(operand) < visited_nr) {
-				int tmp;
-
-				set_irn_visited(operand, visited_nr);
-				tmp = max_hops_walker(env, operand, bl, depth + 1, visited_nr);
-				res = MAX(tmp, res);
-			}
-		}
-
-		return res;
-	}
-
-	/*
-	 * If the node is in the current block and scheduled, return
-	 * the depth which indicates the number of steps to the
-	 * region of scheduled nodes.
-	 */
-	return depth;
-}
-
-static int compute_max_hops(reg_pressure_selector_env_t *env, ir_node *irn)
-{
-	ir_node *bl   = get_nodes_block(irn);
-	ir_graph *irg = get_irn_irg(bl);
-	int res       = 0;
-
-	const ir_edge_t *edge;
-
-	foreach_out_edge(irn, edge) {
-		ir_node *user       = get_edge_src_irn(edge);
-		unsigned visited_nr = get_irg_visited(irg) + 1;
-		int max_hops;
-
-		set_irg_visited(irg, visited_nr);
-		max_hops = max_hops_walker(env, user, irn, 0, visited_nr);
-		res      = MAX(res, max_hops);
-	}
-
-	return res;
-}
-
-static void *reg_pressure_graph_init(const list_sched_selector_t *vtab, const arch_env_t *arch_env, ir_graph *irg)
-{
-	reg_pressure_main_env_t *main_env = xmalloc(sizeof(main_env[0]));
-
-	main_env->arch_env = arch_env;
-	main_env->vtab     = vtab;
-	irg_walk_graph(irg, firm_clear_link, NULL, NULL);
-
-	return main_env;
-}
-
-static void *reg_pressure_block_init(void *graph_env, ir_node *bl)
-{
-	ir_node *irn;
-	reg_pressure_selector_env_t *env  = xmalloc(sizeof(env[0]));
-
-	obstack_init(&env->obst);
-	env->already_scheduled = new_nodeset(32);
-	env->root              = NULL;
-	env->main_env          = graph_env;
-
-	/*
-	 * Collect usage statistics.
-	 */
-	sched_foreach(bl, irn) {
-		if(must_appear_in_schedule(env->main_env->vtab, env, irn)) {
-			int i, n;
-
-			for(i = 0, n = get_irn_arity(irn); i < n; ++i) {
-				//ir_node *op = get_irn_n(irn, i);
-				if(must_appear_in_schedule(env->main_env->vtab, env, irn)) {
-					usage_stats_t *us = get_or_set_usage_stats(env, irn);
-#if 0 /* Liveness is not computed here! */
-					if(is_live_end(bl, op))
-						us->uses_in_block = 99999;
-					else
-#endif
-						us->uses_in_block++;
-				}
-			}
-		}
-	}
-
-	return env;
-}
-
-static void reg_pressure_block_free(void *block_env)
-{
-	reg_pressure_selector_env_t *env = block_env;
-	usage_stats_t *us;
-
-	for(us = env->root; us; us = us->next)
-		set_irn_link(us->irn, NULL);
-
-	obstack_free(&env->obst, NULL);
-	del_nodeset(env->already_scheduled);
-	free(env);
-}
-
-static int get_result_hops_sum(reg_pressure_selector_env_t *env, ir_node *irn)
-{
-	int res = 0;
-	if(get_irn_mode(irn) == mode_T) {
-		const ir_edge_t *edge;
-
-		foreach_out_edge(irn, edge)
-			res += get_result_hops_sum(env, get_edge_src_irn(edge));
-	}
-
-	else if(mode_is_data(get_irn_mode(irn)))
-		res = compute_max_hops(env, irn);
-
-
-	return res;
-}
-
-static INLINE int reg_pr_costs(reg_pressure_selector_env_t *env, ir_node *irn)
-{
-	int i, n;
-	int sum = 0;
-
-	for(i = 0, n = get_irn_arity(irn); i < n; ++i) {
-		ir_node *op = get_irn_n(irn, i);
-
-		if(must_appear_in_schedule(env->main_env->vtab, env, op))
-			sum += compute_max_hops(env, op);
-	}
-
-	sum += get_result_hops_sum(env, irn);
-
-	return sum;
-}
-
-static ir_node *reg_pressure_select(void *block_env, nodeset *ready_set)
-{
-	reg_pressure_selector_env_t *env = block_env;
-	ir_node *irn, *res     = NULL;
-	int curr_cost          = INT_MAX;
-
-	assert(nodeset_count(ready_set) > 0);
-
-	for (irn = nodeset_first(ready_set); irn; irn = nodeset_next(ready_set)) {
-		/*
-			Ignore branch instructions for the time being.
-			They should only be scheduled if there is nothing else.
-		*/
-		if (! arch_irn_class_is(env->main_env->arch_env, irn, branch)) {
-			int costs = reg_pr_costs(env, irn);
-			if (costs <= curr_cost) {
-				res       = irn;
-				curr_cost = costs;
-			}
-		}
-	}
-
-	/*
-		There was no result so we only saw a branch.
-		Take it and finish.
-	*/
-
-	if(!res) {
-		res = nodeset_first(ready_set);
-		nodeset_break(ready_set);
-
-		assert(res && "There must be a node scheduled.");
-	}
-
-	nodeset_insert(env->already_scheduled, res);
-	return res;
-}
-
 /**
  * Environment for a block scheduler.
  */
 typedef struct _block_sched_env_t {
 	sched_irn_t *sched_info;                    /**< scheduling info per node, copied from the global scheduler object */
-	sched_timestep_t curr_time;                 /**< current time of the scheduler */
-	nodeset *cands;                             /**< the set of candidates */
+	ir_nodeset_t cands;                         /**< the set of candidates */
 	ir_node *block;                             /**< the current block */
 	sched_env_t *sched_env;                     /**< the scheduler environment */
-	nodeset *live;                              /**< simple liveness during scheduling */
+	ir_nodeset_t live;                          /**< simple liveness during scheduling */
 	const list_sched_selector_t *selector;
 	void *selector_block_env;
-	DEBUG_ONLY(firm_dbg_module_t *dbg;)
 } block_sched_env_t;
 
 /**
- * Returns non-zero if the node is already scheduled
+ * Returns non-zero if a node must be placed in the schedule.
  */
-static INLINE int is_already_scheduled(block_sched_env_t *env, ir_node *n)
+static INLINE int must_appear_in_schedule(const list_sched_selector_t *sel, void *block_env, const ir_node *irn)
 {
-	int idx = get_irn_idx(n);
+	int res = -1;
 
-	assert(idx < ARR_LEN(env->sched_info));
-	return env->sched_info[idx].already_sched;
-}
+	/* if there are no uses, don't schedule */
+	if (get_irn_n_edges(irn) < 1)
+		return 0;
 
-/**
- * Mark a node as already scheduled
- */
-static INLINE void mark_already_scheduled(block_sched_env_t *env, ir_node *n)
-{
-	int idx = get_irn_idx(n);
+	/* else ask the scheduler */
+	if (sel->to_appear_in_schedule)
+		res = sel->to_appear_in_schedule(block_env, irn);
 
-	assert(idx < ARR_LEN(env->sched_info));
-	env->sched_info[idx].already_sched = 1;
+	return res >= 0 ? res : ((to_appear_in_schedule(irn) || BE_SCHED_NODE(irn)) && ! is_Unknown(irn));
 }
 
 /**
- * Returns non-zero if the node is a root node
+ * Returns non-zero if the node is already scheduled
  */
-static INLINE unsigned is_root_node(block_sched_env_t *env, ir_node *n)
+static INLINE int is_already_scheduled(block_sched_env_t *env, ir_node *n)
 {
 	int idx = get_irn_idx(n);
 
 	assert(idx < ARR_LEN(env->sched_info));
-	return env->sched_info[idx].is_root;
+	return env->sched_info[idx].already_sched;
 }
 
 /**
- * Mark a node as roto node
+ * Mark a node as already scheduled
  */
-static INLINE void mark_root_node(block_sched_env_t *env, ir_node *n)
+static INLINE void set_already_scheduled(block_sched_env_t *env, ir_node *n)
 {
 	int idx = get_irn_idx(n);
 
 	assert(idx < ARR_LEN(env->sched_info));
-	env->sched_info[idx].is_root = 1;
-}
-
-/**
- * Get the current delay.
- */
-static INLINE sched_timestep_t get_irn_delay(block_sched_env_t *env, ir_node *n) {
-	int idx = get_irn_idx(n);
-
-	assert(idx < ARR_LEN(env->sched_info));
-	return env->sched_info[idx].delay;
-}
-
-/**
- * Set the current delay.
- */
-static INLINE void set_irn_delay(block_sched_env_t *env, ir_node *n, sched_timestep_t delay) {
-	int idx = get_irn_idx(n);
-
-	assert(idx < ARR_LEN(env->sched_info));
-	env->sched_info[idx].delay = delay;
-}
-
-/**
- * Get the current etime.
- */
-static INLINE sched_timestep_t get_irn_etime(block_sched_env_t *env, ir_node *n) {
-	int idx = get_irn_idx(n);
-
-	assert(idx < ARR_LEN(env->sched_info));
-	return env->sched_info[idx].etime;
-}
-
-/**
- * Set the current etime.
- */
-static INLINE void set_irn_etime(block_sched_env_t *env, ir_node *n, sched_timestep_t etime) {
-	int idx = get_irn_idx(n);
-
-	assert(idx < ARR_LEN(env->sched_info));
-	env->sched_info[idx].etime = etime;
-}
-
-/**
- * Get the number of users.
- */
-static INLINE unsigned get_irn_num_user(block_sched_env_t *env, ir_node *n) {
-	int idx = get_irn_idx(n);
-
-	assert(idx < ARR_LEN(env->sched_info));
-	return env->sched_info[idx].num_user;
-}
-
-/**
- * Set the number of users.
- */
-static INLINE void set_irn_num_user(block_sched_env_t *env, ir_node *n, unsigned num_user) {
-	int idx = get_irn_idx(n);
-
-	assert(idx < ARR_LEN(env->sched_info));
-	env->sched_info[idx].num_user = num_user;
-}
-
-/**
- * Get the register difference.
- */
-static INLINE int get_irn_reg_diff(block_sched_env_t *env, ir_node *n) {
-	int idx = get_irn_idx(n);
-
-	assert(idx < ARR_LEN(env->sched_info));
-	return env->sched_info[idx].reg_diff;
-}
-
-/**
- * Set the register difference.
- */
-static INLINE void set_irn_reg_diff(block_sched_env_t *env, ir_node *n, int reg_diff) {
-	int idx = get_irn_idx(n);
-
-	assert(idx < ARR_LEN(env->sched_info));
-	env->sched_info[idx].reg_diff = reg_diff;
-}
-
-/**
- * Get the pre-order position.
- */
-static INLINE int get_irn_preorder(block_sched_env_t *env, ir_node *n) {
-	int idx = get_irn_idx(n);
-
-	assert(idx < ARR_LEN(env->sched_info));
-	return env->sched_info[idx].preorder;
-}
-
-/**
- * Set the pre-order position.
- */
-static INLINE void set_irn_preorder(block_sched_env_t *env, ir_node *n, int pos) {
-	int idx = get_irn_idx(n);
-
-	assert(idx < ARR_LEN(env->sched_info));
-	env->sched_info[idx].preorder = pos;
-}
-
-/**
- * returns the exec-time for node n.
- */
-static sched_timestep_t exectime(sched_env_t *env, ir_node *n) {
-  if (be_is_Keep(n) || is_Proj(n))
-    return 0;
-	if (env->selector->exectime)
-		return env->selector->exectime(env->selector_env, n);
-	return 1;
+	env->sched_info[idx].already_sched = 1;
 }
 
-/**
- * Calculates the latency for between two ops
- */
-static sched_timestep_t latency(sched_env_t *env, ir_node *pred, int pred_cycle, ir_node *curr, int curr_cycle) {
-	/* a Keep hides a root */
-	if (be_is_Keep(curr))
-		return exectime(env, pred);
-
-	/* Proj's are executed immediately */
-	if (is_Proj(curr))
-		return 0;
-
-	/* predecessors Proj's must be skipped */
-	if (is_Proj(pred))
-		pred = get_Proj_pred(pred);
-
-	if (env->selector->latency)
-		return env->selector->latency(env->selector_env, pred, pred_cycle, curr, curr_cycle);
-	return 1;
-}
+static void add_to_sched(block_sched_env_t *env, ir_node *irn);
 
 /**
  * Try to put a node in the ready set.
@@ -591,48 +212,45 @@ static sched_timestep_t latency(sched_env_t *env, ir_node *pred, int pred_cycle,
 static INLINE int make_ready(block_sched_env_t *env, ir_node *pred, ir_node *irn)
 {
 	int i, n;
-	sched_timestep_t etime_p, etime;
-
-    /* Blocks cannot be scheduled. */
-    if (is_Block(irn))
-        return 0;
-
-    /*
-     * Check, if the given ir node is in a different block as the
-     * currently scheduled one. If that is so, don't make the node ready.
-     */
-    if (env->block != get_nodes_block(irn))
-        return 0;
-
-    for (i = 0, n = get_irn_arity(irn); i < n; ++i) {
-        ir_node *op = get_irn_n(irn, i);
-
-        /* if irn is an End we have keep-alives and op might be a block, skip that */
-        if (is_Block(op)) {
-          assert(get_irn_op(irn) == op_End);
-          continue;
-        }
-
-        /* If the operand is local to the scheduled block and not yet
-         * scheduled, this nodes cannot be made ready, so exit. */
-        if (!is_already_scheduled(env, op) && get_nodes_block(op) == env->block)
-            return 0;
-    }
 
-    nodeset_insert(env->cands, irn);
+	/* Blocks cannot be scheduled. */
+	if (is_Block(irn) || get_irn_n_edges(irn) == 0)
+		return 0;
+
+	/*
+	 * Check, if the given ir node is in a different block as the
+	 * currently scheduled one. If that is so, don't make the node ready.
+	 */
+	if (env->block != get_nodes_block(irn))
+		return 0;
+
+	for (i = 0, n = get_irn_ins_or_deps(irn); i < n; ++i) {
+		ir_node *op = get_irn_in_or_dep(irn, i);
 
-	/* calculate the etime of this node */
-	etime = env->curr_time;
-	if (pred) {
-		etime_p  = get_irn_etime(env, pred);
-		etime   += latency(env->sched_env, pred, 1, irn, 0);
+		/* if irn is an End we have keep-alives and op might be a block, skip that */
+		if (is_Block(op)) {
+		  	assert(get_irn_op(irn) == op_End);
+			continue;
+		}
 
-		etime = etime_p > etime ? etime_p : etime;
+		/* If the operand is local to the scheduled block and not yet
+		 * scheduled, this nodes cannot be made ready, so exit. */
+		if (! is_already_scheduled(env, op) && get_nodes_block(op) == env->block)
+			return 0;
 	}
 
-	set_irn_etime(env, irn, etime);
+	if (! must_appear_in_schedule(env->selector, env, irn)) {
+		add_to_sched(env, irn);
+		DB((dbg, LEVEL_3, "\tmaking immediately available: %+F\n", irn));
+	} else {
+		ir_nodeset_insert(&env->cands, irn);
 
-    DB((env->dbg, LEVEL_2, "\tmaking ready: %+F etime %u\n", irn, etime));
+		/* Notify selector about the ready node. */
+		if (env->selector->node_ready)
+			env->selector->node_ready(env->selector_block_env, irn, pred);
+
+		DB((dbg, LEVEL_2, "\tmaking ready: %+F\n", irn));
+	}
 
     return 1;
 }
@@ -640,17 +258,27 @@ static INLINE int make_ready(block_sched_env_t *env, ir_node *pred, ir_node *irn
 /**
  * Try, to make all users of a node ready.
  * In fact, a usage node can only be made ready, if all its operands
- * have already been scheduled yet. This is checked my make_ready().
+ * have already been scheduled yet. This is checked by make_ready().
  * @param env The block schedule environment.
  * @param irn The node, which usages (successors) are to be made ready.
  */
-static INLINE void make_users_ready(block_sched_env_t *env, ir_node *irn)
+static void make_users_ready(block_sched_env_t *env, ir_node *irn)
 {
 	const ir_edge_t *edge;
 
+	/* make all data users ready */
 	foreach_out_edge(irn, edge) {
-		ir_node *user = edge->src;
-		if(!is_Phi(user))
+		ir_node *user = get_edge_src_irn(edge);
+
+		if (! is_Phi(user))
+			make_ready(env, irn, user);
+	}
+
+	/* and the dependent nodes as well */
+	foreach_out_edge_kind(irn, edge, EDGE_KIND_DEP) {
+		ir_node *user = get_edge_src_irn(edge);
+
+		if (! is_Phi(user))
 			make_ready(env, irn, user);
 	}
 }
@@ -690,7 +318,7 @@ static INLINE int add_irn_not_sched_user(block_sched_env_t *env, ir_node *n, int
  * Returns the number of users of a node having mode datab.
  */
 static int get_num_successors(ir_node *irn) {
-	int sum = 0;
+	int             sum = 0;
 	const ir_edge_t *edge;
 
 	if (get_irn_mode(irn) == mode_T) {
@@ -699,10 +327,11 @@ static int get_num_successors(ir_node *irn) {
 			ir_node *proj = get_edge_src_irn(edge);
 			ir_mode *mode = get_irn_mode(proj);
 
-			if (mode == mode_T)
+			if (mode == mode_T) {
 				sum += get_num_successors(proj);
-			else if (mode_is_datab(mode))
+			} else if (mode_is_datab(mode)) {
 				sum += get_irn_n_edges(proj);
+			}
 		}
 	}
 	else {
@@ -718,7 +347,7 @@ static int get_num_successors(ir_node *irn) {
 
 /**
  * Adds irn to @p live, updates all inputs that this user is scheduled
- * and counts all of it's non scheduled users.
+ * and counts all of its non scheduled users.
  */
 static void update_sched_liveness(block_sched_env_t *env, ir_node *irn) {
 	int i;
@@ -727,17 +356,16 @@ static void update_sched_liveness(block_sched_env_t *env, ir_node *irn) {
 	if (is_Proj(irn))
 		return;
 
-	for (i = get_irn_arity(irn) - 1; i >= 0; i--) {
-		ir_node *in = get_irn_n(irn, i);
+	for (i = get_irn_ins_or_deps(irn) - 1; i >= 0; --i) {
+		ir_node *in = get_irn_in_or_dep(irn, i);
 
 		/* if in is a proj: update predecessor */
-		while (is_Proj(in))
-			in = get_Proj_pred(in);
+		in = skip_Proj(in);
 
 		/* if in is still in the live set: reduce number of users by one */
-		if (nodeset_find(env->live, in)) {
+		if (ir_nodeset_contains(&env->live, in)) {
 			if (add_irn_not_sched_user(env, in, -1) <= 0)
-				nodeset_remove(env->live, in);
+				ir_nodeset_remove(&env->live, in);
 		}
 	}
 
@@ -750,251 +378,38 @@ static void update_sched_liveness(block_sched_env_t *env, ir_node *irn) {
 	i = get_num_successors(irn);
 	if (i > 0) {
 		set_irn_not_sched_user(env, irn, i);
-		nodeset_insert(env->live, irn);
+		ir_nodeset_insert(&env->live, irn);
 	}
 }
 
-/**
- * Returns the current register pressure for the current block
- * while scheduling.
- * This is the number of already scheduled nodes having not yet
- * scheduled users.
- */
-static INLINE int get_cur_reg_pressure(block_sched_env_t *env) {
-	/*
-		Nodes with all users scheduled are removed from live set,
-		so the number of nodes in this set represent the current
-		register pressure in this block.
-	*/
-	return nodeset_count(env->live);
-}
-
 /**
  * Append an instruction to a schedule.
  * @param env The block scheduling environment.
  * @param irn The node to add to the schedule.
  * @return    The given node.
  */
-static ir_node *add_to_sched(block_sched_env_t *env, ir_node *irn)
+static void add_to_sched(block_sched_env_t *env, ir_node *irn)
 {
     /* If the node consumes/produces data, it is appended to the schedule
      * list, otherwise, it is not put into the list */
-    if(must_appear_in_schedule(env->selector, env->selector_block_env, irn)) {
-        sched_info_t *info = get_irn_sched_info(irn);
-        INIT_LIST_HEAD(&info->list);
-        info->scheduled = 1;
+    if (must_appear_in_schedule(env->selector, env->selector_block_env, irn)) {
 		update_sched_liveness(env, irn);
-        sched_add_before(env->block, irn);
-
-        DBG((env->dbg, LEVEL_2, "\tadding %+F\n", irn));
-    }
-
-    /* Insert the node in the set of all already scheduled nodes. */
-    mark_already_scheduled(env, irn);
-
-    /* Remove the node from the ready set */
-    if(nodeset_find(env->cands, irn))
-        nodeset_remove(env->cands, irn);
-
-    return irn;
-}
-
-/**
- * Add the proj nodes of a tuple-mode irn to the schedule immediately
- * after the tuple-moded irn. By pinning the projs after the irn, no
- * other nodes can create a new lifetime between the tuple-moded irn and
- * one of its projs. This should render a realistic image of a
- * tuple-moded irn, which in fact models a node which defines multiple
- * values.
- *
- * @param irn The tuple-moded irn.
- */
-static void add_tuple_projs(block_sched_env_t *env, ir_node *irn)
-{
-	const ir_edge_t *edge;
-
-	assert(get_irn_mode(irn) == mode_T && "Mode of node must be tuple");
-
-	if(is_Bad(irn))
-		return;
-
-	foreach_out_edge(irn, edge) {
-		ir_node *out = edge->src;
-
-		assert(is_Proj(out) && "successor of a modeT node must be a proj");
-
-		if (get_irn_mode(out) == mode_T)
-			add_tuple_projs(env, out);
-		else {
-			add_to_sched(env, out);
-			make_users_ready(env, out);
-		}
-	}
-}
-
-/**
- * Returns the difference of regs_output - regs_input;
- */
-static int get_reg_difference(block_sched_env_t *be, ir_node *irn) {
-	int num_out = 0;
-	int num_in  = 0;
-	int i;
-
-	if (get_irn_mode(irn) == mode_T) {
-		/* mode_T nodes: num out regs == num Projs with mode datab */
-		const ir_edge_t *edge;
-		foreach_out_edge(irn, edge) {
-			ir_node *proj = get_edge_src_irn(edge);
-			if (mode_is_datab(get_irn_mode(proj)))
-				num_out++;
-		}
-	}
-	else
-		num_out = 1;
-
-	/* num in regs: number of ins with mode datab and not ignore */
-	for (i = get_irn_arity(irn) - 1; i >= 0; i--) {
-		ir_node *in = get_irn_n(irn, i);
-		if (mode_is_datab(get_irn_mode(in)) && ! arch_irn_is(be->sched_env->arch_env, irn, ignore))
-			num_in++;
-	}
-
-	return num_out - num_in;
-}
-
-/**
- * Execute the heuristic function,
- */
-static ir_node *select_node_heuristic(block_sched_env_t *be, nodeset *ns)
-{
-	ir_node *irn, *cand = NULL;
-
-/* prefer instructions which can be scheduled early */
-#define PRIO_TIME       16
-/* prefer instructions with lots of successors */
-#define PRIO_NUMSUCCS    4
-/* prefer instructions with long critical path */
-#define PRIO_LEVEL      12
-/* prefer instructions coming early in preorder */
-#define PRIO_PREORD      8
-/* weight of current register pressure */
-#define PRIO_CUR_PRESS  20
-/* weight of register pressure difference */
-#define PRIO_CHG_PRESS  14
-
-	/* schedule keeps as early as possible */
-	foreach_nodeset(ns, irn) {
-		if (be_is_Keep(irn)) {
-			nodeset_break(ns);
-			return irn;
-		}
-	}
-
-	if (be->sched_env->use_heuristic) {
-		int max_prio     = INT_MIN;
-		int cur_prio     = INT_MIN;
-		int cur_pressure = get_cur_reg_pressure(be);
-
-		/* priority based selection, heuristic inspired by mueller diss */
-		foreach_nodeset(ns, irn) {
-			/* make sure that branches are scheduled last */
-			if (! arch_irn_class_is(be->sched_env->arch_env, irn, branch)) {
-				cur_prio = (get_irn_delay(be, irn) << PRIO_LEVEL)
-					+ (get_irn_num_user(be, irn) << PRIO_NUMSUCCS)
-					- (get_irn_etime(be, irn) << PRIO_TIME)
-					- ((get_irn_reg_diff(be, irn) >> PRIO_CHG_PRESS) << ((cur_pressure >> PRIO_CUR_PRESS) - 3))
-					+ (get_irn_preorder(be, irn) << PRIO_PREORD); /* high preorder means: early scheduled in pre-order list */
-				if (cur_prio > max_prio) {
-					cand     = irn;
-					max_prio = cur_prio;
-				}
-			}
-		}
-
-		if (cand) {
-			DBG((be->dbg, LEVEL_4, "heuristic selected %+F:\n", cand));
-			DBG((be->dbg, LEVEL_4, "\tpriority: %d\n", cand));
-			DBG((be->dbg, LEVEL_4, "\tdelay:    %d (%d)\n", get_irn_delay(be, cand), get_irn_delay(be, cand) << PRIO_LEVEL));
-			DBG((be->dbg, LEVEL_4, "\t#user:    %d (%d)\n", get_irn_num_user(be, cand), get_irn_num_user(be, cand) << PRIO_NUMSUCCS));
-			DBG((be->dbg, LEVEL_4, "\tetime:    %d (%d)\n", get_irn_etime(be, cand), -(get_irn_etime(be, cand) << PRIO_TIME)));
-			DBG((be->dbg, LEVEL_4, "\tpreorder: %d (%d)\n", get_irn_preorder(be, cand), get_irn_preorder(be, cand) << PRIO_PREORD));
-			DBG((be->dbg, LEVEL_4, "\treg diff: %d (%d)\n", get_irn_reg_diff(be, cand), -(((get_irn_reg_diff(be, cand) >> PRIO_CHG_PRESS) << ((cur_pressure >> PRIO_CUR_PRESS) - 3)))));
-			DBG((be->dbg, LEVEL_4, "\tpressure: %d\n", cur_pressure));
-		}
-		else {
-			cand = nodeset_first(ns);
-		}
-	}
-	else {
-		/* use backend selector */
-		cand = be->selector->select(be->selector_block_env, ns);
-	}
+		sched_add_before(env->block, irn);
 
-	return cand;
-}
-
-/**
- * Returns non-zero if root is a root in the block block.
- */
-static int is_root(ir_node *root, ir_node *block) {
-	const ir_edge_t *edge;
-
-	foreach_out_edge(root, edge) {
-		ir_node *succ = get_edge_src_irn(edge);
-
-		if (is_Block(succ))
-			continue;
-		/* Phi nodes are always in "another block */
-		if (is_Phi(succ))
-			continue;
-		if (get_nodes_block(succ) == block)
-			return 0;
-	}
-	return 1;
-}
-
-/* we need a special mark */
-static char _mark;
-#define MARK	&_mark
-
-static firm_dbg_module_t *xxxdbg;
+		DBG((dbg, LEVEL_2, "\tadding %+F\n", irn));
 
-/**
- * descent into a dag and create a pre-order list.
- */
-static void descent(ir_node *root, ir_node *block, ir_node **list, block_sched_env_t *env, int cur_depth) {
-	int i;
-
-	cur_depth++;
-
-	if (! is_Phi(root)) {
-		/* Phi nodes always leave the block */
-		for (i = get_irn_arity(root) - 1; i >= 0; --i) {
-			ir_node *pred = get_irn_n(root, i);
-
-			DBG((xxxdbg, LEVEL_3, "   node %+F\n", pred));
-			/* Blocks may happen as predecessors of End nodes */
-			if (is_Block(pred))
-				continue;
-
-			/* already seen nodes are not marked */
-			if (get_irn_link(pred) != MARK)
-				continue;
-
-			/* don't leave our block */
-			if (get_nodes_block(pred) != block)
-				continue;
+	   	/* Remove the node from the ready set */
+		ir_nodeset_remove(&env->cands, irn);
+    }
 
-			set_irn_link(pred, NULL);
-			set_irn_preorder(env, pred, cur_depth);
+	/* notify the selector about the finally selected node. */
+	if (env->selector->node_selected)
+		env->selector->node_selected(env->selector_block_env, irn);
 
-			descent(pred, block, list, env, cur_depth);
-		}
-	}
-	set_irn_link(root, *list);
-	*list = root;
+    /* Insert the node in the set of all available scheduled nodes. */
+    set_already_scheduled(env, irn);
 
-	cur_depth--;
+	make_users_ready(env, irn);
 }
 
 /**
@@ -1013,284 +428,185 @@ static void list_sched_block(ir_node *block, void *env_ptr)
 	sched_env_t *env                      = env_ptr;
 	const list_sched_selector_t *selector = env->selector;
 	ir_node *start_node                   = get_irg_start(get_irn_irg(block));
-	sched_info_t *info                    = get_irn_sched_info(block);
 
 	block_sched_env_t be;
 	const ir_edge_t *edge;
 	ir_node *irn;
 	int j, m;
 
-	ir_node *root = NULL, *preord = NULL;
-	ir_node *curr;
-
 	/* Initialize the block's list head that will hold the schedule. */
-	INIT_LIST_HEAD(&info->list);
+	sched_init_block(block);
 
 	/* Initialize the block scheduling environment */
-	be.sched_info        = env->sched_info;
-	be.block             = block;
-	be.curr_time         = 0;
-	be.cands             = new_nodeset(get_irn_n_edges(block));
-	be.live              = new_nodeset(get_irn_n_edges(block));
-	be.selector          = selector;
-	be.sched_env         = env;
-	FIRM_DBG_REGISTER(be.dbg, "firm.be.sched");
-	FIRM_DBG_REGISTER(xxxdbg, "firm.be.sched");
-
-	//	firm_dbg_set_mask(be.dbg, SET_LEVEL_3);
+	be.sched_info = env->sched_info;
+	be.block      = block;
+	ir_nodeset_init_size(&be.cands, get_irn_n_edges(block));
+	ir_nodeset_init_size(&be.live, get_irn_n_edges(block));
+	be.selector   = selector;
+	be.sched_env  = env;
+
+	DBG((dbg, LEVEL_1, "scheduling %+F\n", block));
 
 	if (selector->init_block)
 		be.selector_block_env = selector->init_block(env->selector_env, block);
 
-	DBG((be.dbg, LEVEL_1, "scheduling %+F\n", block));
-
-	/* First step: Find the root set. */
+	/* Then one can add all nodes are ready to the set. */
 	foreach_out_edge(block, edge) {
-		ir_node *succ = get_edge_src_irn(edge);
-
-		if (is_root(succ, block)) {
-			mark_root_node(&be, succ);
-			set_irn_link(succ, root);
-			root = succ;
-		}
-		else
-			set_irn_link(succ, MARK);
-	}
+		ir_node   *irn = get_edge_src_irn(edge);
+		ir_opcode code = get_irn_opcode(irn);
+		int users;
 
-	/* Second step: calculate the pre-order list. */
-	preord = NULL;
-	for (curr = root; curr; curr = irn) {
-		irn = get_irn_link(curr);
-		DBG((be.dbg, LEVEL_2, "   DAG root %+F\n", curr));
-		descent(curr, block, &preord, &be, 0);
-	}
-	root = preord;
-
-	/* Third step: calculate the Delay. Note that our
-	* list is now in pre-order, starting at root
-	*/
-	for (curr = root; curr; curr = get_irn_link(curr)) {
-		sched_timestep_t d;
-
-		if (arch_irn_class_is(env->arch_env, curr, branch)) {
-			/* assure, that branches can be executed last */
-			d = 0;
-		}
-		else {
-			if (is_root_node(&be, curr))
-				d = exectime(env, curr);
-			else {
-				d = 0;
-				foreach_out_edge(curr, edge) {
-					ir_node *n = get_edge_src_irn(edge);
-
-					if (get_nodes_block(n) == block) {
-						sched_timestep_t ld;
-
-						ld = latency(env, curr, 1, n, 0) + get_irn_delay(&be, n);
-						d = ld > d ? ld : d;
-					}
-				}
-			}
+		if (code == iro_End) {
+			/* Skip the end node because of keep-alive edges. */
+			continue;
+		} else if (code == iro_Block) {
+			/* A Block-Block edge. This should be the MacroBlock
+			 * edge, ignore it. */
+			assert(get_Block_MacroBlock(irn) == block && "Block-Block edge found");
+			continue;
 		}
-		set_irn_delay(&be, curr, d);
-		DB((be.dbg, LEVEL_2, "\t%+F delay %u\n", curr, d));
-
-		/* set the etime of all nodes to 0 */
-		set_irn_etime(&be, curr, 0);
-	}
-
-
-	/* Then one can add all nodes are ready to the set. */
-	foreach_out_edge(block, edge) {
-		ir_node *irn = get_edge_src_irn(edge);
 
-		/* Skip the end node because of keepalive edges. */
-		if (get_irn_opcode(irn) == iro_End)
+		users = get_irn_n_edges(irn);
+		if (users == 0)
 			continue;
+		else if (users == 1) { /* ignore nodes that are only hold by the anchor */
+			const ir_edge_t *edge = get_irn_out_edge_first_kind(irn, EDGE_KIND_NORMAL);
+			ir_node *user = get_edge_src_irn(edge);
+			if (is_Anchor(user))
+				continue;
+		}
 
 		if (is_Phi(irn)) {
-			/* Phi functions are scheduled immediately, since they only transfer
-			* data flow from the predecessors to this block. */
-
-			/* Increase the time step. */
-			be.curr_time += get_irn_etime(&be, irn);
+			/*
+				Phi functions are scheduled immediately, since they	only
+				transfer data flow from the predecessors to this block.
+			*/
 			add_to_sched(&be, irn);
-			make_users_ready(&be, irn);
 		}
 		else if (irn == start_node) {
 			/* The start block will be scheduled as the first node */
-			be.curr_time += get_irn_etime(&be, irn);
-
 			add_to_sched(&be, irn);
-			add_tuple_projs(&be, irn);
 		}
 		else {
 			/* Other nodes must have all operands in other blocks to be made
-			* ready */
+			 * ready */
 			int ready = 1;
 
 			/* Check, if the operands of a node are not local to this block */
-			for (j = 0, m = get_irn_arity(irn); j < m; ++j) {
-				ir_node *operand = get_irn_n(irn, j);
+			for (j = 0, m = get_irn_ins_or_deps(irn); j < m; ++j) {
+				ir_node *operand = get_irn_in_or_dep(irn, j);
 
 				if (get_nodes_block(operand) == block) {
 					ready = 0;
 					break;
-				}
-				else {
+				} else {
 					/* live in values increase register pressure */
-					update_sched_liveness(&be, operand);
+					ir_nodeset_insert(&be.live, operand);
 				}
 			}
 
 			/* Make the node ready, if all operands live in a foreign block */
 			if (ready) {
-				DBG((be.dbg, LEVEL_2, "\timmediately ready: %+F\n", irn));
+				DBG((dbg, LEVEL_2, "\timmediately ready: %+F\n", irn));
 				make_ready(&be, NULL, irn);
 			}
-
-			/* calculate number of users (needed for heuristic) */
-			set_irn_num_user(&be, irn, get_num_successors(irn));
-
-			/* calculate register difference (needed for heuristic) */
-			set_irn_reg_diff(&be, irn, get_reg_difference(&be, irn));
 		}
 	}
 
-	while (nodeset_count(be.cands) > 0) {
-		nodeset *mcands;                            /**< the set of candidates with maximum delay time */
-		nodeset *ecands;                            /**< the set of nodes in mcands whose etime <= curr_time  */
-		sched_timestep_t max_delay = 0;
-
+	/* Iterate over all remaining nodes */
+	while (ir_nodeset_size(&be.cands) > 0) {
+		ir_nodeset_iterator_t iter;
 		/* collect statistics about amount of ready nodes */
-		be_do_stat_sched_ready(block, be.cands);
-
-		/* calculate the max delay of all candidates */
-		foreach_nodeset(be.cands, irn) {
-			sched_timestep_t d = get_irn_delay(&be, irn);
+		be_do_stat_sched_ready(block, &be.cands);
 
-			max_delay = d > max_delay ? d : max_delay;
-		}
-		mcands = new_nodeset(8);
-		ecands = new_nodeset(8);
-
-		/* calculate mcands and ecands */
-		foreach_nodeset(be.cands, irn) {
-			if (be_is_Keep(irn)) {
-				nodeset_break(be.cands);
+		/* Keeps must be scheduled immediately */
+		foreach_ir_nodeset(&be.cands, irn, iter) {
+			if (be_is_Keep(irn) || be_is_CopyKeep(irn) || is_Sync(irn)) {
 				break;
 			}
-			if (get_irn_delay(&be, irn) == max_delay) {
-				nodeset_insert(mcands, irn);
-				if (get_irn_etime(&be, irn) <= be.curr_time)
-					nodeset_insert(ecands, irn);
-			}
 		}
 
-		if (irn) {
+		if (! irn) {
 			/* Keeps must be immediately scheduled */
+			irn = be.selector->select(be.selector_block_env, &be.cands, &be.live);
 		}
-		else {
-			DB((be.dbg, LEVEL_2, "\tbe.curr_time = %u\n", be.curr_time));
-
-			/* select a node to be scheduled and check if it was ready */
-			if (nodeset_count(mcands) == 1) {
-				irn = nodeset_first(mcands);
-				DB((be.dbg, LEVEL_3, "\tirn = %+F, mcand = 1, max_delay = %u\n", irn, max_delay));
-			}
-			else {
-				int cnt = nodeset_count(ecands);
-				if (cnt == 1) {
-					irn = nodeset_first(ecands);
-
-					if (arch_irn_class_is(env->arch_env, irn, branch)) {
-						/* BEWARE: don't select a JUMP if others are still possible */
-						goto force_mcands;
-					}
-					DB((be.dbg, LEVEL_3, "\tirn = %+F, ecand = 1, max_delay = %u\n", irn, max_delay));
-				}
-				else if (cnt > 1) {
-					DB((be.dbg, LEVEL_3, "\tecand = %d, max_delay = %u\n", cnt, max_delay));
-					irn = select_node_heuristic(&be, ecands);
-				}
-				else {
-force_mcands:
-					DB((be.dbg, LEVEL_3, "\tmcand = %d\n", nodeset_count(mcands)));
-					irn = select_node_heuristic(&be, mcands);
-				}
-			}
-		}
-		del_nodeset(mcands);
-		del_nodeset(ecands);
-
-		DB((be.dbg, LEVEL_2, "\tpicked node %+F\n", irn));
 
-		/* Increase the time step. */
-		be.curr_time += exectime(env, irn);
+		DB((dbg, LEVEL_2, "\tpicked node %+F\n", irn));
 
 		/* Add the node to the schedule. */
 		add_to_sched(&be, irn);
 
-		if (get_irn_mode(irn) == mode_T)
-			add_tuple_projs(&be, irn);
-		else
-			make_users_ready(&be, irn);
-
 		/* remove the scheduled node from the ready list. */
-		if (nodeset_find(be.cands, irn))
-			nodeset_remove(be.cands, irn);
+		ir_nodeset_remove(&be.cands, irn);
 	}
 
 	if (selector->finish_block)
 		selector->finish_block(be.selector_block_env);
 
-	del_nodeset(be.cands);
-	del_nodeset(be.live);
+	ir_nodeset_destroy(&be.cands);
+	ir_nodeset_destroy(&be.live);
 }
 
-static const list_sched_selector_t reg_pressure_selector_struct = {
-	reg_pressure_graph_init,
-	reg_pressure_block_init,
-	reg_pressure_select,
-	NULL,                    /* to_appear_in_schedule */
-	NULL,                    /* exectime */
-	NULL,                    /* latency */
-	reg_pressure_block_free,
-	free
-};
-
-const list_sched_selector_t *reg_pressure_selector = &reg_pressure_selector_struct;
-
 /* List schedule a graph. */
-void list_sched(const be_irg_t *birg, be_options_t *be_opts)
+void list_sched(be_irg_t *birg, be_options_t *be_opts)
 {
 	const arch_env_t *arch_env = birg->main_env->arch_env;
-	ir_graph *irg              = birg->irg;
+	ir_graph         *irg      = birg->irg;
 
 	int num_nodes;
 	sched_env_t env;
-	mris_env_t *mris;
+	mris_env_t *mris = NULL;
+	list_sched_selector_t sel;
+
+	(void)be_opts;
+
+	/* Select a scheduler based on backend options */
+	switch (list_sched_options.select) {
+		case BE_SCHED_SELECT_TRIVIAL:  sel = trivial_selector;      break;
+		case BE_SCHED_SELECT_RANDOM:   sel = random_selector;       break;
+		case BE_SCHED_SELECT_REGPRESS: sel = reg_pressure_selector; break;
+		case BE_SCHED_SELECT_MUCHNIK:  sel = muchnik_selector;      break;
+		case BE_SCHED_SELECT_HEUR:     sel = heuristic_selector;    break;
+		case BE_SCHED_SELECT_NORMAL:   sel = normal_selector;       break;
+		default:
+		case BE_SCHED_SELECT_HMUCHNIK: sel = trivial_selector;      break;
+	}
 
-	/* Assure, that the out edges are computed */
-	edges_assure(irg);
+#if 1
+	/* Matze: This is very slow, we should avoid it to improve backend speed,
+	 * we just have to make sure that we have no dangling out-edges at this
+	 * point...
+	 */
 
-	if(be_opts->mris)
-		mris = be_sched_mris_preprocess(birg);
+	/* Assure, that we have no dangling out-edges to deleted stuff */
+	edges_deactivate(birg->irg);
+	edges_activate(birg->irg);
+#endif
+
+	switch (list_sched_options.prep) {
+		case BE_SCHED_PREP_MRIS:
+			mris = be_sched_mris_preprocess(birg);
+			break;
+		case BE_SCHED_PREP_RSS:
+			rss_schedule_preparation(birg);
+			break;
+		default:
+			break;
+	}
 
 	num_nodes = get_irg_last_idx(irg);
 
+	/* initialize environment for list scheduler */
 	memset(&env, 0, sizeof(env));
-	env.selector      = arch_env->isa->impl->get_list_sched_selector(arch_env->isa);
-	env.arch_env      = arch_env;
-	env.irg           = irg;
-	env.use_heuristic = be_opts->sched_select == BE_SCHED_SELECT_HEUR ? 1 : 0;
-	env.sched_info    = NEW_ARR_F(sched_irn_t, num_nodes);
+	env.selector   = arch_env_get_list_sched_selector(arch_env, &sel);
+	env.arch_env   = arch_env;
+	env.irg        = irg;
+	env.sched_info = NEW_ARR_F(sched_irn_t, num_nodes);
 
-	memset(env.sched_info, 0, num_nodes * sizeof(*env.sched_info));
+	memset(env.sched_info, 0, num_nodes * sizeof(env.sched_info[0]));
 
 	if (env.selector->init_graph)
-		env.selector_env = env.selector->init_graph(env.selector, arch_env, irg);
+		env.selector_env = env.selector->init_graph(env.selector, birg);
 
 	/* Schedule each single block. */
 	irg_block_walk_graph(irg, list_sched_block, NULL, &env);
@@ -1298,8 +614,74 @@ void list_sched(const be_irg_t *birg, be_options_t *be_opts)
 	if (env.selector->finish_graph)
 		env.selector->finish_graph(env.selector_env);
 
-	if(be_opts->mris)
+	if (list_sched_options.prep == BE_SCHED_PREP_MRIS)
 		be_sched_mris_free(mris);
 
 	DEL_ARR_F(env.sched_info);
 }
+
+/* List schedule a block. */
+void list_sched_single_block(const be_irg_t *birg, ir_node *block,
+                             be_options_t *be_opts)
+{
+	const arch_env_t *arch_env = birg->main_env->arch_env;
+	ir_graph         *irg      = birg->irg;
+
+	int num_nodes;
+	sched_env_t env;
+	list_sched_selector_t sel;
+
+	(void)be_opts;
+
+	/* Select a scheduler based on backend options */
+	switch (list_sched_options.select) {
+		case BE_SCHED_SELECT_TRIVIAL:  sel = trivial_selector;      break;
+		case BE_SCHED_SELECT_RANDOM:   sel = random_selector;       break;
+		case BE_SCHED_SELECT_REGPRESS: sel = reg_pressure_selector; break;
+		case BE_SCHED_SELECT_MUCHNIK:  sel = muchnik_selector;      break;
+		case BE_SCHED_SELECT_HEUR:     sel = heuristic_selector;    break;
+		case BE_SCHED_SELECT_NORMAL:   sel = normal_selector;       break;
+		default:
+		case BE_SCHED_SELECT_HMUCHNIK: sel = trivial_selector;      break;
+	}
+
+	/* Assure, that the out edges are computed */
+	edges_deactivate(birg->irg);
+	edges_activate(birg->irg);
+
+	num_nodes = get_irg_last_idx(irg);
+
+	/* initialize environment for list scheduler */
+	memset(&env, 0, sizeof(env));
+	env.selector   = arch_env_get_list_sched_selector(arch_env, &sel);
+	env.arch_env   = arch_env;
+	env.irg        = irg;
+	env.sched_info = NEW_ARR_F(sched_irn_t, num_nodes);
+
+	memset(env.sched_info, 0, num_nodes * sizeof(env.sched_info[0]));
+
+	if (env.selector->init_graph)
+		env.selector_env = env.selector->init_graph(env.selector, birg);
+
+	/* Schedule block. */
+	list_sched_block(block, &env);
+
+	if (env.selector->finish_graph)
+		env.selector->finish_graph(env.selector_env);
+
+	DEL_ARR_F(env.sched_info);
+}
+
+/**
+ * Register list scheduler options.
+ */
+void be_init_listsched(void) {
+	lc_opt_entry_t *be_grp = lc_opt_get_grp(firm_opt_get_root(), "be");
+	lc_opt_entry_t *sched_grp = lc_opt_get_grp(be_grp, "listsched");
+
+	lc_opt_add_table(sched_grp, list_sched_option_table);
+
+	FIRM_DBG_REGISTER(dbg, "firm.be.sched");
+}
+
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_listsched);