X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;ds=sidebyside;f=ir%2Fbe%2Fbelistsched.c;h=b172575baa264026ed251f44d4eb31b52018e8ba;hb=6d5b4983239cffb1b219b90c40128332f5a91b77;hp=9b38faa23c7bfca2608301436b75e425c762fdf4;hpb=5e1f95efc1491481487ba22482422b6d6f42bcdb;p=libfirm

diff --git a/ir/be/belistsched.c b/ir/be/belistsched.c
index 9b38faa23..b172575ba 100644
--- a/ir/be/belistsched.c
+++ b/ir/be/belistsched.c
@@ -26,24 +26,37 @@
 #include "irmode_t.h"
 #include "irdump.h"
 #include "irprintf_t.h"
+#include "array.h"
 #include "debug.h"
+#include "irtools.h"
 
 #include "besched_t.h"
 #include "beutil.h"
 #include "belive_t.h"
 #include "belistsched.h"
+#include "beschedmris.h"
 #include "bearch.h"
+#include "bestat.h"
 
-#define MAX(x,y) ((x) > (y) ? (x) : (y))
-#define MIN(x,y) ((x) < (y) ? (x) : (y))
+/**
+ * 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 already_sched : 1; /**< Set if this node is already scheduled */
+	unsigned is_root       : 1; /**< is a root node of a block */
+} sched_irn_t;
 
 /**
  * Scheduling environment for the whole graph.
  */
 typedef struct _sched_env_t {
-    const ir_graph *irg;                        /**< The graph to schedule. */
-    const list_sched_selector_t *selector;		  /**< The node selector. */
-    void *selector_env;                         /**< A pointer to give to the selector. */
+	sched_irn_t *sched_info;                    /**< scheduling info per node */
+	const list_sched_selector_t *selector;      /**< The node selector. */
+	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. */
 } sched_env_t;
 
 #if 0
@@ -74,32 +87,74 @@ static int cmp_usage(const void *a, const void *b)
 }
 #endif
 
-static ir_node *trivial_select(void *block_env, pset *ready_set)
+/**
+ * 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)
 {
-	ir_node *res;
+	const arch_env_t *arch_env = block_env;
+	ir_node *irn = NULL;
+	int const_last = 0;
 
-	res = pset_first(ready_set);
-	pset_break(ready_set);
-	return res;
+	/* assure that branches and constants are executed last */
+	for (irn = nodeset_first(ready_set); irn; irn = nodeset_next(ready_set)) {
+		arch_irn_class_t irn_class = arch_irn_classify(arch_env, irn);
+
+		if (irn_class != arch_irn_class_branch && (const_last ? (irn_class != arch_irn_class_const) : 1)) {
+			nodeset_break(ready_set);
+			return irn;
+		}
+	}
+
+	/* assure that constants are executed before branches */
+	if (const_last) {
+		for (irn = nodeset_first(ready_set); irn; irn = nodeset_next(ready_set)) {
+			if (arch_irn_classify(arch_env, irn) != arch_irn_class_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 = 0;
+	int res = -1;
 
 	if(sel->to_appear_in_schedule)
 		res = sel->to_appear_in_schedule(block_env, irn);
 
-	return res || to_appear_in_schedule(irn) || be_is_Keep(irn) || be_is_RegParams(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 = {
-	NULL,
-	NULL,
+	trivial_init_graph,
+	trivial_init_block,
 	trivial_select,
-	NULL,
-	NULL,
-	NULL
+	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;
@@ -113,11 +168,16 @@ typedef struct _usage_stats_t {
 							  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;
-	pset *already_scheduled;
-	const list_sched_selector_t *vtab;
+	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)
@@ -158,7 +218,7 @@ static int max_hops_walker(reg_pressure_selector_env_t *env, ir_node *irn, ir_no
 	 * If the node is in the current block but not
 	 * yet scheduled, we keep on searching from that node.
 	 */
-	if(!pset_find_ptr(env->already_scheduled, irn)) {
+	if(!nodeset_find(env->already_scheduled, irn)) {
 		int i, n;
 		int res = 0;
 		for(i = 0, n = get_irn_arity(irn); i < n; ++i) {
@@ -205,10 +265,15 @@ static int compute_max_hops(reg_pressure_selector_env_t *env, ir_node *irn)
 	return res;
 }
 
-static void *reg_pressure_graph_init(const list_sched_selector_t *vtab, const arch_isa_t *isa, ir_graph *irg)
+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 (void *) vtab;
+
+	return main_env;
 }
 
 static void *reg_pressure_block_init(void *graph_env, ir_node *bl)
@@ -217,20 +282,20 @@ static void *reg_pressure_block_init(void *graph_env, ir_node *bl)
 	reg_pressure_selector_env_t *env  = xmalloc(sizeof(env[0]));
 
 	obstack_init(&env->obst);
-	env->already_scheduled = pset_new_ptr(32);
+	env->already_scheduled = new_nodeset(32);
 	env->root              = NULL;
-	env->vtab              = graph_env;
+	env->main_env          = graph_env;
 
 	/*
 	 * Collect usage statistics.
 	 */
 	sched_foreach(bl, irn) {
-		if(must_appear_in_schedule(env->vtab, env, 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->vtab, env, irn)) {
+				if(must_appear_in_schedule(env->main_env->vtab, env, irn)) {
 					usage_stats_t *us = get_or_set_usage_stats(env, irn);
 					if(is_live_end(bl, op))
 						us->uses_in_block = 99999;
@@ -253,7 +318,7 @@ static void reg_pressure_block_free(void *block_env)
 		set_irn_link(us->irn, NULL);
 
 	obstack_free(&env->obst, NULL);
-	del_pset(env->already_scheduled);
+	del_nodeset(env->already_scheduled);
 	free(env);
 }
 
@@ -282,7 +347,7 @@ static INLINE int reg_pr_costs(reg_pressure_selector_env_t *env, ir_node *irn)
 	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->vtab, env, op))
+		if(must_appear_in_schedule(env->main_env->vtab, env, op))
 			sum += compute_max_hops(env, op);
 	}
 
@@ -291,126 +356,229 @@ static INLINE int reg_pr_costs(reg_pressure_selector_env_t *env, ir_node *irn)
 	return sum;
 }
 
-static ir_node *reg_pressure_select(void *block_env, pset *ready_set)
+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(pset_count(ready_set) > 0);
-
-	for(irn = pset_first(ready_set); irn; irn = pset_next(ready_set)) {
-		int costs = reg_pr_costs(env, irn);
-		if(costs <= curr_cost) {
-			res       = irn;
-			curr_cost = costs;
+	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_classify(env->main_env->arch_env, irn) != arch_irn_class_branch) {
+			int costs = reg_pr_costs(env, irn);
+			if (costs <= curr_cost) {
+				res       = irn;
+				curr_cost = costs;
+			}
 		}
 	}
 
-	pset_insert_ptr(env->already_scheduled, res);
+	/*
+		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;
 }
 
-static const list_sched_selector_t reg_pressure_selector_struct = {
-	reg_pressure_graph_init,
-	reg_pressure_block_init,
-	reg_pressure_select,
-	NULL,
-	reg_pressure_block_free,
-	NULL
-};
+/**
+ * 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_node *block;                             /**< the current block */
+	sched_env_t *sched_env;                     /**< the scheduler environment */
+	const list_sched_selector_t *selector;
+	void *selector_block_env;
+	DEBUG_ONLY(firm_dbg_module_t *dbg;)
+} block_sched_env_t;
 
-const list_sched_selector_t *reg_pressure_selector = &reg_pressure_selector_struct;
+/**
+ * Returns non-zero if the node is already scheduled
+ */
+static INLINE int is_already_scheduled(block_sched_env_t *env, ir_node *n)
+{
+	int idx = get_irn_idx(n);
 
-static void list_sched_block(ir_node *block, void *env_ptr);
+	assert(idx < ARR_LEN(env->sched_info));
+	return env->sched_info[idx].already_sched;
+}
 
-void list_sched(const struct _arch_isa_t *isa, ir_graph *irg)
+/**
+ * Mark a node as already scheduled
+ */
+static INLINE void mark_already_scheduled(block_sched_env_t *env, ir_node *n)
 {
-	sched_env_t env;
-	const list_sched_selector_t *selector;
+	int idx = get_irn_idx(n);
 
-	memset(&env, 0, sizeof(env));
-	selector = env.selector = isa->impl->get_list_sched_selector(isa);
-	env.selector_env = selector->init_graph ? selector->init_graph(selector, isa, irg) : NULL;
-	env.irg = irg;
+	assert(idx < ARR_LEN(env->sched_info));
+	env->sched_info[idx].already_sched = 1;
+}
 
-	/* Assure, that the out edges are computed */
-	edges_assure(irg);
+/**
+ * Returns non-zero if the node is a root node
+ */
+static INLINE unsigned is_root_node(block_sched_env_t *env, ir_node *n)
+{
+	int idx = get_irn_idx(n);
 
-	/* Schedule each single block. */
-	irg_block_walk_graph(irg, list_sched_block, NULL, &env);
+	assert(idx < ARR_LEN(env->sched_info));
+	return env->sched_info[idx].is_root;
+}
+
+/**
+ * Mark a node as roto node
+ */
+static INLINE void mark_root_node(block_sched_env_t *env, ir_node *n)
+{
+	int idx = get_irn_idx(n);
 
-	if(selector->finish_graph)
-		selector->finish_graph(env.selector_env);
+	assert(idx < ARR_LEN(env->sched_info));
+	env->sched_info[idx].is_root = 1;
 }
 
+/**
+ * Get the current delay.
+ */
+static 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;
+}
 
 /**
- * Environment for a block scheduler.
+ * Set the current delay.
  */
-typedef struct _block_sched_env_t {
-	int curr_time;
-	pset *ready_set;
-	pset *already_scheduled;
-	ir_node *block;
-	firm_dbg_module_t *dbg;
-	const list_sched_selector_t *selector;
-	void *selector_block_env;
-} block_sched_env_t;
+static 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 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 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;
+}
+
+/**
+ * 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;
+}
+
+/**
+ * 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;
+}
 
 /**
  * Try to put a node in the ready set.
- * @param env The block scheduler environment.
- * @param irn The node to make ready.
+ * @param env   The block scheduler environment.
+ * @param pred  The previous scheduled node.
+ * @param irn   The node to make ready.
  * @return 1, if the node could be made ready, 0 else.
  */
-static INLINE int make_ready(block_sched_env_t *env, ir_node *irn)
+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))
+    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))
+    if (env->block != get_nodes_block(irn))
         return 0;
 
-    for(i = 0, n = get_irn_arity(irn); i < n; ++i) {
+    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(!pset_find_ptr(env->already_scheduled, op) && get_nodes_block(op) == env->block)
+        if (!is_already_scheduled(env, op) && get_nodes_block(op) == env->block)
             return 0;
     }
 
-    DBG((env->dbg, LEVEL_2, "\tmaking ready: %+F\n", irn));
-    pset_insert_ptr(env->ready_set, irn);
+    nodeset_insert(env->cands, irn);
 
-    return 1;
-}
+		/* 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);
 
-/**
- * Check, if a node is ready in a block schedule.
- * @param env The block schedule environment.
- * @param irn The node to check for.
- * @return 1 if the node was ready, 0 if not.
- */
-#define is_ready(env,irn) \
-  (pset_find_ptr((env)->ready_set, irn) != NULL)
+			etime = etime_p > etime ? etime_p : etime;
+		}
 
-/**
- * Check, if a node has already been schedules.
- * @param env The block schedule environment.
- * @param irn The node to check for.
- * @return 1 if the node was already scheduled, 0 if not.
- */
-#define is_scheduled(env,irn) \
-  (pset_find_ptr((env)->already_scheduled, irn) != NULL)
+		set_irn_etime(env, irn, etime);
+
+    DB((env->dbg, LEVEL_2, "\tmaking ready: %+F etime %u\n", irn, etime));
+
+    return 1;
+}
 
 /**
  * Try, to make all users of a node ready.
@@ -426,7 +594,7 @@ static INLINE void make_users_ready(block_sched_env_t *env, ir_node *irn)
 	foreach_out_edge(irn, edge) {
 		ir_node *user = edge->src;
 		if(!is_Phi(user))
-			make_ready(env, user);
+			make_ready(env, irn, user);
 	}
 }
 
@@ -461,11 +629,11 @@ static ir_node *add_to_sched(block_sched_env_t *env, ir_node *irn)
     }
 
     /* Insert the node in the set of all already scheduled nodes. */
-    pset_insert_ptr(env->already_scheduled, irn);
+    mark_already_scheduled(env, irn);
 
     /* Remove the node from the ready set */
-    if(pset_find_ptr(env->ready_set, irn))
-        pset_remove_ptr(env->ready_set, irn);
+    if(nodeset_find(env->cands, irn))
+        nodeset_remove(env->cands, irn);
 
     return irn;
 }
@@ -479,14 +647,6 @@ static ir_node *add_to_sched(block_sched_env_t *env, ir_node *irn)
  * values.
  *
  * @param irn The tuple-moded irn.
- * @param list The schedule list to append all the projs.
- * @param time The time step to which the irn and all its projs are
- * related to.
- * @param obst The obstack the scheduling data structures shall be
- * created upon.
- * @param ready_set The ready set of the list scheduler.
- * @param already_scheduled A set containing all nodes already
- * scheduled.
  */
 static void add_tuple_projs(block_sched_env_t *env, ir_node *irn)
 {
@@ -494,12 +654,15 @@ static void add_tuple_projs(block_sched_env_t *env, ir_node *irn)
 
 	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)
+		if (get_irn_mode(out) == mode_T)
 			add_tuple_projs(env, out);
 		else {
 			add_to_sched(env, out);
@@ -508,18 +671,75 @@ static void add_tuple_projs(block_sched_env_t *env, ir_node *irn)
 	}
 }
 
-static ir_node *select_node(block_sched_env_t *be)
+/**
+ * Execute the heuristic function,
+ */
+static ir_node *select_node_heuristic(block_sched_env_t *be, nodeset *ns)
 {
 	ir_node *irn;
 
-	for(irn = pset_first(be->ready_set); irn; irn = pset_next(be->ready_set)) {
-		if(be_is_Keep(irn)) {
-			pset_break(be->ready_set);
+	for (irn = nodeset_first(ns); irn; irn = nodeset_next(ns)) {
+		if (be_is_Keep(irn)) {
+			nodeset_break(ns);
 			return irn;
 		}
 	}
 
-	return be->selector->select(be->selector_block_env, be->ready_set);
+	return be->selector->select(be->selector_block_env, ns);
+}
+
+/**
+ * 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
+
+/**
+ * descent into a dag and create a pre-order list.
+ */
+static void descent(ir_node *root, ir_node *block, ir_node **list) {
+	int i;
+
+	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);
+
+			/* 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;
+
+			descent(pred, block, list);
+		}
+	}
+	set_irn_link(root, *list);
+	*list = root;
 }
 
 /**
@@ -535,112 +755,284 @@ static ir_node *select_node(block_sched_env_t *be)
  */
 static void list_sched_block(ir_node *block, void *env_ptr)
 {
-	sched_env_t *env = env_ptr;
-	block_sched_env_t be;
+	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;
-	ir_node *start_node = get_irg_start(get_irn_irg(block));
-	ir_node *final_jmp  = NULL;
 	int j, m;
-	int phi_seen = 0;
-	sched_info_t *info = get_irn_sched_info(block);
+
+	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);
 
 	/* Initialize the block scheduling environment */
-	be.dbg               = firm_dbg_register("firm.be.sched");
+	be.sched_info        = env->sched_info;
 	be.block             = block;
 	be.curr_time         = 0;
-	be.ready_set         = new_pset(node_cmp_func, get_irn_n_edges(block));
-	be.already_scheduled = new_pset(node_cmp_func, get_irn_n_edges(block));
+	be.cands             = new_nodeset(get_irn_n_edges(block));
 	be.selector          = selector;
+	be.sched_env         = env;
+	FIRM_DBG_REGISTER(be.dbg, "firm.be.sched");
+
+//	firm_dbg_set_mask(be.dbg, SET_LEVEL_3);
 
-	if(selector->init_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. */
+	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);
+	}
+
+	/* Second step: calculate the pre-order list. */
+	preord = NULL;
+	for (curr = root; curr; curr = irn) {
+		irn = get_irn_link(curr);
+		descent(curr, block, &preord);
+	}
+	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_classify(env->arch_env, curr) == arch_irn_class_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;
+					}
+				}
+			}
+		}
+		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)
+		if (get_irn_opcode(irn) == iro_End)
 			continue;
 
-		/* Phi functions are scheduled immediately, since they only transfer
-		 * data flow from the predecessors to this block. */
-		if(is_Phi(irn)) {
+		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);
 			add_to_sched(&be, irn);
 			make_users_ready(&be, irn);
-			phi_seen = 1;
 		}
+		else if (irn == start_node) {
+			/* The start block will be scheduled as the first node */
+			be.curr_time += get_irn_etime(&be, irn);
 
-		else if(irn == start_node) {
 			add_to_sched(&be, irn);
 			add_tuple_projs(&be, irn);
 		}
-
-		else if(get_irn_opcode(irn) == iro_Jmp) {
-			final_jmp = irn;
-		}
-
-		/* Other nodes must have all operands in other blocks to be made
-		 * ready */
 		else {
+			/* Other nodes must have all operands in other blocks to be made
+			 * 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) {
+			for (j = 0, m = get_irn_arity(irn); j < m; ++j) {
 				ir_node *operand = get_irn_n(irn, j);
 
-				if(get_nodes_block(operand) == block) {
+				if (get_nodes_block(operand) == block) {
 					ready = 0;
 					break;
 				}
 			}
 
 			/* Make the node ready, if all operands live in a foreign block */
-			if(ready) {
+			if (ready) {
 				DBG((be.dbg, LEVEL_2, "\timmediately ready: %+F\n", irn));
-				make_ready(&be, irn);
+				make_ready(&be, NULL, irn);
 			}
 		}
 	}
 
-	/* Increase the time, if some phi functions have been scheduled */
-	be.curr_time += phi_seen;
+	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;
+
+		/* collect statistics about amount of ready nodes */
+		be_do_stat_sched_ready(block, be.cands);
 
-	while(pset_count(be.ready_set) > 0) {
-		/* select a node to be scheduled and check if it was ready */
-		irn = select_node(&be);
+		/* calculate the max delay of all candidates */
+		foreach_nodeset(be.cands, irn) {
+			sched_timestep_t d = get_irn_delay(&be, irn);
 
-		DBG((be.dbg, LEVEL_3, "\tpicked node %+F\n", irn));
+			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);
+        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) {
+      /* Keeps must be immediately scheduled */
+    }
+    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) {
+			  DB((be.dbg, LEVEL_3, "\tmcand = 1, max_delay = %u\n", max_delay));
+			  irn = nodeset_first(mcands);
+		  }
+		  else {
+			  int cnt = nodeset_count(ecands);
+			  if (cnt == 1) {
+					arch_irn_class_t irn_class;
+
+				  irn = nodeset_first(ecands);
+					irn_class = arch_irn_classify(env->arch_env, irn);
+
+					if (irn_class == arch_irn_class_branch) {
+						/* BEWARE: don't select a JUMP if others are still possible */
+						goto force_mcands;
+					}
+				  DB((be.dbg, LEVEL_3, "\tecand = 1, max_delay = %u\n", 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);
 
 		/* Add the node to the schedule. */
 		add_to_sched(&be, irn);
 
-		if(get_irn_mode(irn) == mode_T)
+		if (get_irn_mode(irn) == mode_T)
 			add_tuple_projs(&be, irn);
 		else
 			make_users_ready(&be, irn);
 
-		/* Increase the time step. */
-		be.curr_time += 1;
-
 		/* remove the scheduled node from the ready list. */
-		if(pset_find_ptr(be.ready_set, irn))
-			pset_remove_ptr(be.ready_set, irn);
+		if (nodeset_find(be.cands, irn))
+			nodeset_remove(be.cands, irn);
 	}
 
-	if(selector->finish_block)
+	if (selector->finish_block)
 		selector->finish_block(be.selector_block_env);
 
-	if(final_jmp)
-		add_to_sched(&be, final_jmp);
+	del_nodeset(be.cands);
+}
+
+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, int enable_mris)
+{
+	const arch_env_t *arch_env = birg->main_env->arch_env;
+	ir_graph *irg              = birg->irg;
+
+	int num_nodes;
+	sched_env_t env;
+	mris_env_t *mris;
+
+	/* Assure, that the out edges are computed */
+	edges_assure(irg);
+
+	if(enable_mris)
+		mris = be_sched_mris_preprocess(birg);
+
+	num_nodes = get_irg_last_idx(irg);
+
+	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.sched_info = NEW_ARR_F(sched_irn_t, num_nodes);
+
+	memset(env.sched_info, 0, num_nodes * sizeof(*env.sched_info));
+
+	if (env.selector->init_graph)
+		env.selector_env = env.selector->init_graph(env.selector, arch_env, irg);
+
+	/* Schedule each single block. */
+	irg_block_walk_graph(irg, list_sched_block, NULL, &env);
+
+	if (env.selector->finish_graph)
+		env.selector->finish_graph(env.selector_env);
+
+	if(enable_mris)
+		be_sched_mris_free(mris);
 
-	del_pset(be.ready_set);
-	del_pset(be.already_scheduled);
+	DEL_ARR_F(env.sched_info);
 }