X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbespillbelady.c;h=6b249f50455c22ffe3412a775f8ee5ed2b1f2ae3;hb=c57decb6b15b5490d4c3e9e546d8024556e2263f;hp=48b0bb1109d6a5ce29306cc3a751243639773170;hpb=508dbb88a1f5caddda5d515d0d81bb300d75d5ab;p=libfirm

diff --git a/ir/be/bespillbelady.c b/ir/be/bespillbelady.c
index 48b0bb110..6b249f504 100644
--- a/ir/be/bespillbelady.c
+++ b/ir/be/bespillbelady.c
@@ -1,26 +1,33 @@
-/**
- * Author:      Daniel Grund, Matthias Braun
- * Date:        20.09.2005
- * Copyright:   (c) Universitaet Karlsruhe
- * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
+/*
+ * Copyright (C) 1995-2011 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.
  */
-#ifdef HAVE_CONFIG_H
-#include <config.h>
-#endif
 
-#ifdef HAVE_ALLOCA_H
-#include <alloca.h>
-#endif
+/**
+ * @file
+ * @brief       Beladys spillalgorithm.
+ * @author      Daniel Grund, Matthias Braun
+ * @date        20.09.2005
+ */
+#include "config.h"
 
-#ifdef HAVE_MALLOC_H
-#include <malloc.h>
-#endif
+#include <stdbool.h>
 
 #include "obst.h"
-#include "set.h"
-#include "pset.h"
-#include "irprintf_t.h"
 #include "irgraph.h"
 #include "irnode.h"
 #include "irmode.h"
@@ -29,105 +36,103 @@
 #include "iredges_t.h"
 #include "ircons_t.h"
 #include "irprintf.h"
+#include "irnodeset.h"
+#include "irtools.h"
+#include "statev_t.h"
+#include "util.h"
 
 #include "beutil.h"
 #include "bearch.h"
-#include "bespillbelady.h"
-#include "beuses_t.h"
-#include "besched_t.h"
+#include "beuses.h"
+#include "besched.h"
 #include "beirgmod.h"
 #include "belive_t.h"
-#include "benode_t.h"
+#include "benode.h"
 #include "bechordal_t.h"
-#include "bespilloptions.h"
+#include "bespill.h"
 #include "beloopana.h"
-
-#define DBG_SPILL   1
-#define DBG_WSETS   2
-#define DBG_FIX     4
-#define DBG_DECIDE  8
-#define DBG_START  16
-#define DBG_SLOTS  32
-#define DBG_TRACE  64
+#include "beirg.h"
+#include "bespillutil.h"
+#include "bemodule.h"
+
+#define DBG_SPILL     1
+#define DBG_WSETS     2
+#define DBG_FIX       4
+#define DBG_DECIDE    8
+#define DBG_START    16
+#define DBG_SLOTS    32
+#define DBG_TRACE    64
 #define DBG_WORKSET 128
 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
 
+#define TIME_UNDEFINED 6666
+
 /**
  * An association between a node and a point in time.
  */
-typedef struct _loc_t {
-  ir_node *irn;        /**< A node. */
-  unsigned time;       /**< A use time (see beuses.h). */
+typedef struct loc_t {
+	ir_node          *node;
+	unsigned          time;     /**< A use time (see beuses.h). */
+	bool              spilled;  /**< value was already spilled on this path */
 } loc_t;
 
-typedef struct _workset_t {
-	int len;			/**< current length */
-	loc_t vals[0];		/**< inlined array of the values/distances in this working set */
+typedef struct workset_t {
+	unsigned len;     /**< current length */
+	loc_t    vals[];  /**< array of the values/distances in this working set */
 } workset_t;
 
-typedef struct _belady_env_t {
-	struct obstack ob;
-	const arch_env_t *arch;
-	const arch_register_class_t *cls;
-	const be_lv_t *lv;
-	be_loopana_t *loop_ana;
-	int n_regs;			/** number of regs in this reg-class */
-
-	workset_t *ws;		/**< the main workset used while processing a block. ob-allocated */
-	be_uses_t *uses;	/**< env for the next-use magic */
-	ir_node *instr;		/**< current instruction */
-	unsigned instr_nr;	/**< current instruction number (relative to block start) */
-	pset *used;
-
-	spill_env_t *senv;	/**< see bespill.h */
-} belady_env_t;
-
-static int loc_compare(const void *a, const void *b)
-{
-	const loc_t *p = a;
-	const loc_t *q = b;
-	return p->time - q->time;
-}
-
-static INLINE void workset_print(const workset_t *w)
-{
-	int i;
-
-	for(i = 0; i < w->len; ++i) {
-		ir_fprintf(stderr, "%+F %d\n", w->vals[i].irn, w->vals[i].time);
-	}
-}
+static struct obstack               obst;
+static const arch_register_class_t *cls;
+static const be_lv_t               *lv;
+static be_loopana_t                *loop_ana;
+static unsigned                     n_regs;
+static workset_t                   *ws;     /**< the main workset used while
+	                                             processing a block. */
+static be_uses_t                   *uses;   /**< env for the next-use magic */
+static ir_node                     *instr;  /**< current instruction */
+static spill_env_t                 *senv;   /**< see bespill.h */
+static ir_node                    **blocklist;
+
+static int                          move_spills      = true;
+static int                          respectloopdepth = true;
+static int                          improve_known_preds = true;
+/* factor to weight the different costs of reloading/rematerializing a node
+   (see bespill.h be_get_reload_costs_no_weight) */
+static int                          remat_bonus      = 10;
+
+static const lc_opt_table_entry_t options[] = {
+	LC_OPT_ENT_BOOL   ("movespills", "try to move spills out of loops", &move_spills),
+	LC_OPT_ENT_BOOL   ("respectloopdepth", "outermost loop cutting", &respectloopdepth),
+	LC_OPT_ENT_BOOL   ("improveknownpreds", "known preds cutting", &improve_known_preds),
+	LC_OPT_ENT_INT    ("rematbonus", "give bonus to rematerialisable nodes", &remat_bonus),
+	LC_OPT_LAST
+};
 
 /**
  * Alloc a new workset on obstack @p ob with maximum size @p max
  */
-static INLINE workset_t *new_workset(belady_env_t *env, struct obstack *ob) {
-	workset_t *res;
-	size_t size = sizeof(*res) + (env->n_regs)*sizeof(res->vals[0]);
-	res = obstack_alloc(ob, size);
-	memset(res, 0, size);
-	return res;
+static workset_t *new_workset(void)
+{
+	return OALLOCFZ(&obst, workset_t, vals, n_regs);
 }
 
 /**
- * Alloc a new instance on obstack and make it equal to @param ws
+ * Alloc a new instance on obstack and make it equal to @param workset
  */
-static INLINE workset_t *workset_clone(belady_env_t *env, struct obstack *ob, workset_t *ws) {
-	workset_t *res;
-	size_t size = sizeof(*res) + (env->n_regs)*sizeof(res->vals[0]);
-	res = obstack_alloc(ob, size);
-	memcpy(res, ws, size);
+static workset_t *workset_clone(workset_t *workset)
+{
+	workset_t *res = OALLOCF(&obst, workset_t, vals, n_regs);
+	memcpy(res, workset, sizeof(*res) + n_regs * sizeof(res->vals[0]));
 	return res;
 }
 
 /**
- * Do NOT alloc anything. Make @param tgt equal to @param src.
- * returns @param tgt for convenience
+ * Copy workset @param src to @param tgt
  */
-static INLINE workset_t *workset_copy(belady_env_t *env, workset_t *tgt, workset_t *src) {
-	size_t size = sizeof(*src) + (env->n_regs)*sizeof(src->vals[0]);
-	memcpy(tgt, src, size);
-	return tgt;
+static void workset_copy(workset_t *dest, const workset_t *src)
+{
+	size_t size = sizeof(*src) + n_regs * sizeof(src->vals[0]);
+	memcpy(dest, src, size);
 }
 
 /**
@@ -135,7 +140,8 @@ static INLINE workset_t *workset_copy(belady_env_t *env, workset_t *tgt, workset
  * @param count locations given at memory @param locs.
  * Set the length of @param ws to count.
  */
-static INLINE void workset_bulk_fill(workset_t *workset, int count, const loc_t *locs) {
+static void workset_bulk_fill(workset_t *workset, int count, const loc_t *locs)
+{
 	workset->len = count;
 	memcpy(&(workset->vals[0]), locs, count * sizeof(locs[0]));
 }
@@ -144,52 +150,110 @@ static INLINE void workset_bulk_fill(workset_t *workset, int count, const loc_t
  * Inserts the value @p val into the workset, iff it is not
  * already contained. The workset must not be full.
  */
-static INLINE void workset_insert(belady_env_t *env, workset_t *ws, ir_node *val) {
-	int i;
+static void workset_insert(workset_t *workset, ir_node *val, bool spilled)
+{
+	loc_t    *loc;
+	unsigned  i;
 	/* check for current regclass */
-	if (!arch_irn_consider_in_reg_alloc(env->arch, env->cls, val)) {
-		DBG((dbg, DBG_WORKSET, "Skipped %+F\n", val));
-		return;
-	}
+	assert(arch_irn_consider_in_reg_alloc(cls, val));
 
 	/* check if val is already contained */
-	for(i=0; i<ws->len; ++i)
-		if (ws->vals[i].irn == val)
+	for (i = 0; i < workset->len; ++i) {
+		loc = &workset->vals[i];
+		if (loc->node == val) {
+			if (spilled) {
+				loc->spilled = true;
+			}
 			return;
+		}
+	}
 
 	/* insert val */
-	assert(ws->len < env->n_regs && "Workset already full!");
-	ws->vals[ws->len++].irn = val;
+	assert(workset->len < n_regs && "Workset already full!");
+	loc           = &workset->vals[workset->len];
+	loc->node     = val;
+	loc->spilled  = spilled;
+	loc->time     = TIME_UNDEFINED;
+	workset->len++;
 }
 
 /**
  * Removes all entries from this workset
  */
-static INLINE void workset_clear(workset_t *ws) {
-	ws->len = 0;
+static void workset_clear(workset_t *workset)
+{
+	workset->len = 0;
 }
 
 /**
  * Removes the value @p val from the workset if present.
  */
-static INLINE void workset_remove(workset_t *ws, ir_node *val) {
-	int i;
-	for(i=0; i<ws->len; ++i) {
-		if (ws->vals[i].irn == val) {
-			ws->vals[i] = ws->vals[--ws->len];
+static void workset_remove(workset_t *workset, ir_node *val)
+{
+	unsigned i;
+	for (i = 0; i < workset->len; ++i) {
+		if (workset->vals[i].node == val) {
+			workset->vals[i] = workset->vals[--workset->len];
 			return;
 		}
 	}
 }
 
-static INLINE int workset_contains(const workset_t *ws, const ir_node *val) {
-	int i;
-	for(i=0; i<ws->len; ++i) {
-		if (ws->vals[i].irn == val)
-			return 1;
+static const loc_t *workset_contains(const workset_t *ws, const ir_node *val)
+{
+	unsigned i;
+	for (i = 0; i < ws->len; ++i) {
+		if (ws->vals[i].node == val)
+			return &ws->vals[i];
 	}
 
-	return 0;
+	return NULL;
+}
+
+static int loc_compare(const void *a, const void *b)
+{
+	const loc_t   *p  = ((const loc_t*) a);
+	const loc_t   *q  = ((const loc_t*) b);
+	const unsigned pt = p->time;
+	const unsigned qt = q->time;
+
+	if (pt < qt)
+		return -1;
+	if (pt > qt)
+		return 1;
+
+	return get_irn_node_nr(p->node) - get_irn_node_nr(q->node);
+}
+
+static void workset_sort(workset_t *workset)
+{
+	qsort(workset->vals, workset->len, sizeof(workset->vals[0]), loc_compare);
+}
+
+static inline unsigned workset_get_time(const workset_t *workset, unsigned idx)
+{
+	return workset->vals[idx].time;
+}
+
+static inline void workset_set_time(workset_t *workset, unsigned idx,
+                                    unsigned time)
+{
+	workset->vals[idx].time = time;
+}
+
+static inline unsigned workset_get_length(const workset_t *workset)
+{
+	return workset->len;
+}
+
+static inline void workset_set_length(workset_t *workset, unsigned len)
+{
+	workset->len = len;
+}
+
+static inline ir_node *workset_get_val(const workset_t *workset, unsigned idx)
+{
+	return workset->vals[idx].node;
 }
 
 /**
@@ -198,54 +262,57 @@ static INLINE int workset_contains(const workset_t *ws, const ir_node *val) {
  * @p v  A variable to put the current value in
  * @p i  An integer for internal use
  */
-#define workset_foreach(ws, v, i)	for(i=0; \
-										v=(i < ws->len) ? ws->vals[i].irn : NULL, i < ws->len; \
-										++i)
-
-#define workset_set_time(ws, i, t) (ws)->vals[i].time=t
-#define workset_get_time(ws, i) (ws)->vals[i].time
-#define workset_set_length(ws, length) (ws)->len = length
-#define workset_get_length(ws) ((ws)->len)
-#define workset_get_val(ws, i) ((ws)->vals[i].irn)
-#define workset_sort(ws) qsort((ws)->vals, (ws)->len, sizeof((ws)->vals[0]), loc_compare);
-
-typedef struct _block_info_t {
-	workset_t *ws_start, *ws_end;
-	int processed;
-} block_info_t;
+#define workset_foreach(ws, v, i) \
+	for (i=0; v=(i < ws->len) ? ws->vals[i].node : NULL, i < ws->len; ++i)
 
+typedef struct block_info_t {
+	workset_t *start_workset;
+	workset_t *end_workset;
+} block_info_t;
 
-static INLINE void *new_block_info(struct obstack *ob) {
-	block_info_t *res = obstack_alloc(ob, sizeof(*res));
-	res->ws_start = NULL;
-	res->ws_end = NULL;
-	res->processed = 0;
+static block_info_t *new_block_info(void)
+{
+	return OALLOCZ(&obst, block_info_t);
+}
 
-	return res;
+static inline block_info_t *get_block_info(const ir_node *block)
+{
+	return (block_info_t*)get_irn_link(block);
 }
 
-#define get_block_info(block)        ((block_info_t *)get_irn_link(block))
-#define set_block_info(block, info)  set_irn_link(block, info)
+static inline void set_block_info(ir_node *block, block_info_t *info)
+{
+	set_irn_link(block, info);
+}
 
 /**
  * @return The distance to the next use or 0 if irn has dont_spill flag set
  */
-static INLINE unsigned get_distance(belady_env_t *env, ir_node *from, unsigned from_step, const ir_node *def, int skip_from_uses)
+static unsigned get_distance(ir_node *from, const ir_node *def, int skip_from_uses)
 {
 	be_next_use_t use;
-	int flags = arch_irn_get_flags(env->arch, def);
+	unsigned      costs;
+	unsigned      time;
 
-	assert(! (flags & arch_irn_flags_ignore));
+	assert(!arch_irn_is_ignore(def));
 
-	use = be_get_next_use(env->uses, from, from_step, def, skip_from_uses);
-	if(USES_IS_INFINITE(use.time))
+	use  = be_get_next_use(uses, from, def, skip_from_uses);
+	time = use.time;
+	if (USES_IS_INFINITE(time))
 		return USES_INFINITY;
 
 	/* We have to keep nonspillable nodes in the workingset */
-	if(flags & arch_irn_flags_dont_spill)
+	if (arch_get_irn_flags(skip_Proj_const(def)) & arch_irn_flags_dont_spill)
 		return 0;
 
-	return use.time;
+	/* give some bonus to rematerialisable nodes */
+	if (remat_bonus > 0) {
+		costs = be_get_reload_costs_no_weight(senv, def, use.before);
+		assert(costs * remat_bonus < 1000);
+		time  += 1000 - (costs * remat_bonus);
+	}
+
+	return time;
 }
 
 /**
@@ -257,164 +324,268 @@ static INLINE unsigned get_distance(belady_env_t *env, ir_node *from, unsigned f
  * @p is_usage indicates that the values in new_vals are used (not defined)
  * In this case reloads must be performed
  */
-static void displace(belady_env_t *env, workset_t *new_vals, int is_usage) {
-	ir_node *val;
-	int     i, len, max_allowed, demand, iter;
-
-	workset_t *ws         = env->ws;
-	ir_node   **to_insert = alloca(env->n_regs * sizeof(*to_insert));
-
-	/*
-		1. Identify the number of needed slots and the values to reload
-	*/
+static void displace(workset_t *new_vals, int is_usage)
+{
+	ir_node **to_insert = ALLOCAN(ir_node*, n_regs);
+	bool     *spilled   = ALLOCAN(bool,     n_regs);
+	ir_node  *val;
+	int       i;
+	int       len;
+	int       spills_needed;
+	int       demand;
+	unsigned  iter;
+
+	/* 1. Identify the number of needed slots and the values to reload */
 	demand = 0;
 	workset_foreach(new_vals, val, iter) {
-		/* mark value as used */
-		if (is_usage)
-			pset_insert_ptr(env->used, val);
+		bool reloaded = false;
 
 		if (! workset_contains(ws, val)) {
-			DBG((dbg, DBG_DECIDE, "    insert %+F\n", val));
-			to_insert[demand++] = val;
+			DB((dbg, DBG_DECIDE, "    insert %+F\n", val));
 			if (is_usage) {
-				DBG((dbg, DBG_SPILL, "Reload %+F before %+F\n", val, env->instr));
-				be_add_reload(env->senv, val, env->instr, env->cls, 1);
+				DB((dbg, DBG_SPILL, "Reload %+F before %+F\n", val, instr));
+				be_add_reload(senv, val, instr, cls, 1);
+				reloaded = true;
 			}
+		} else {
+			DB((dbg, DBG_DECIDE, "    %+F already in workset\n", val));
+			assert(is_usage);
+			/* remove the value from the current workset so it is not accidently
+			 * spilled */
+			workset_remove(ws, val);
 		}
-		else {
-			assert(is_usage || "Defined value already in workset?!?");
-			DBG((dbg, DBG_DECIDE, "    skip %+F\n", val));
-		}
+		spilled[demand]   = reloaded;
+		to_insert[demand] = val;
+		++demand;
 	}
-	DBG((dbg, DBG_DECIDE, "    demand = %d\n", demand));
-
-	/*
-		2. Make room for at least 'demand' slots
-	*/
-	len         = workset_get_length(ws);
-	max_allowed = env->n_regs - demand;
 
-	DBG((dbg, DBG_DECIDE, "    disposing %d values\n", ws->len - max_allowed));
+	/* 2. Make room for at least 'demand' slots */
+	len           = workset_get_length(ws);
+	spills_needed = len + demand - n_regs;
+	assert(spills_needed <= len);
 
 	/* Only make more free room if we do not have enough */
-	if (len > max_allowed) {
-		/* get current next-use distance */
-		for (i = 0; i < ws->len; ++i) {
-			unsigned dist = get_distance(env, env->instr, env->instr_nr, workset_get_val(ws, i), !is_usage);
+	if (spills_needed > 0) {
+		DB((dbg, DBG_DECIDE, "    disposing %d values\n", spills_needed));
+
+		/* calculate current next-use distance for live values */
+		for (i = 0; i < len; ++i) {
+			ir_node  *val  = workset_get_val(ws, i);
+			unsigned  dist = get_distance(instr, val, !is_usage);
 			workset_set_time(ws, i, dist);
 		}
 
 		/* sort entries by increasing nextuse-distance*/
 		workset_sort(ws);
 
-		/*
-			Logic for not needed live-ins: If a value is disposed
-			before its first usage, remove it from start workset
-			We don't do this for phis though
-		*/
-		for (i = max_allowed; i < ws->len; ++i) {
-			ir_node *irn = ws->vals[i].irn;
-
-			DBG((dbg, DBG_DECIDE, "    disposing %+F (%u)\n", irn, workset_get_time(ws, i)));
-
-            if (is_Phi(irn))
-                continue;
+		for (i = len - spills_needed; i < len; ++i) {
+			ir_node *val = ws->vals[i].node;
 
-			if (! pset_find_ptr(env->used, irn)) {
-				ir_node   *curr_bb  = get_nodes_block(env->instr);
-				workset_t *ws_start = get_block_info(curr_bb)->ws_start;
-				workset_remove(ws_start, irn);
+			DB((dbg, DBG_DECIDE, "    disposing node %+F (%u)\n", val,
+			     workset_get_time(ws, i)));
 
-				DBG((dbg, DBG_DECIDE, "    (and removing %+F from start workset)\n", irn));
+			if (move_spills) {
+				if (!USES_IS_INFINITE(ws->vals[i].time)
+						&& !ws->vals[i].spilled) {
+					ir_node *after_pos = sched_prev(instr);
+					DB((dbg, DBG_DECIDE, "Spill %+F after node %+F\n", val,
+						after_pos));
+					be_add_spill(senv, val, after_pos);
+				}
 			}
 		}
 
 		/* kill the last 'demand' entries in the array */
-		workset_set_length(ws, max_allowed);
+		workset_set_length(ws, len - spills_needed);
 	}
 
-	/*
-		3. Insert the new values into the workset
-	*/
-	for (i = 0; i < demand; ++i)
-		workset_insert(env, env->ws, to_insert[i]);
+	/* 3. Insert the new values into the workset */
+	for (i = 0; i < demand; ++i) {
+		ir_node *val = to_insert[i];
+
+		workset_insert(ws, val, spilled[i]);
+	}
 }
 
-static void belady(ir_node *block, void *env);
+enum {
+	AVAILABLE_EVERYWHERE,
+	AVAILABLE_NOWHERE,
+	AVAILABLE_PARTLY,
+	AVAILABLE_UNKNOWN
+};
 
-static loc_t to_take_or_not_to_take(belady_env_t *env, ir_node* first, ir_node *node, ir_node *block, ir_loop *loop) {
-	be_next_use_t next_use;
-	loc_t loc;
-	loc.time = USES_INFINITY;
+static unsigned available_in_all_preds(workset_t* const* pred_worksets,
+                                       size_t n_pred_worksets,
+                                       const ir_node *value, bool is_local_phi)
+{
+	size_t i;
+	bool   avail_everywhere = true;
+	bool   avail_nowhere    = true;
+
+	assert(n_pred_worksets > 0);
+
+	/* value available in all preds? */
+	for (i = 0; i < n_pred_worksets; ++i) {
+		bool             found     = false;
+		const workset_t *p_workset = pred_worksets[i];
+		int              p_len     = workset_get_length(p_workset);
+		int              p_i;
+		const ir_node   *l_value;
+
+		if (is_local_phi) {
+			assert(is_Phi(value));
+			l_value = get_irn_n(value, i);
+		} else {
+			l_value = value;
+		}
 
-	if (!arch_irn_consider_in_reg_alloc(env->arch, env->cls, node)) {
-		loc.time = USES_INFINITY;
-		return loc;
+		for (p_i = 0; p_i < p_len; ++p_i) {
+			const loc_t *p_l = &p_workset->vals[p_i];
+			if (p_l->node != l_value)
+				continue;
+
+			found = true;
+			break;
+		}
+
+		if (found) {
+			avail_nowhere = false;
+		} else {
+			avail_everywhere = false;
+		}
 	}
 
-	loc.irn = node;
+	if (avail_everywhere) {
+		assert(!avail_nowhere);
+		return AVAILABLE_EVERYWHERE;
+	} else if (avail_nowhere) {
+		return AVAILABLE_NOWHERE;
+	} else {
+		return AVAILABLE_PARTLY;
+	}
+}
+
+/** Decides whether a specific node should be in the start workset or not
+ *
+ * @param env      belady environment
+ * @param first
+ * @param node     the node to test
+ * @param loop     the loop of the node
+ */
+static loc_t to_take_or_not_to_take(ir_node* first, ir_node *node,
+                                    ir_loop *loop, unsigned available)
+{
+	be_next_use_t next_use;
+	loc_t         loc;
+
+	loc.time    = USES_INFINITY;
+	loc.node    = node;
+	loc.spilled = false;
 
 	/* We have to keep nonspillable nodes in the workingset */
-	if(arch_irn_get_flags(env->arch, node) & arch_irn_flags_dont_spill) {
+	if (arch_get_irn_flags(skip_Proj_const(node)) & arch_irn_flags_dont_spill) {
 		loc.time = 0;
-		DBG((dbg, DBG_START, "    %+F taken (dontspill node)\n", node, loc.time));
+		DB((dbg, DBG_START, "    %+F taken (dontspill node)\n", node, loc.time));
 		return loc;
 	}
 
-	next_use = be_get_next_use(env->uses, first, 0, node, 0);
-	if(USES_IS_INFINITE(next_use.time)) {
-		// the nodes marked as live in shouldn't be dead, so it must be a phi
-		loc.time = USES_INFINITY;
-		DBG((dbg, DBG_START, "    %+F not taken (dead)\n", node));
+	next_use = be_get_next_use(uses, first, node, 0);
+	if (USES_IS_INFINITE(next_use.time)) {
+		/* the nodes marked as live in shouldn't be dead, so it must be a phi */
 		assert(is_Phi(node));
+		loc.time = USES_INFINITY;
+		DB((dbg, DBG_START, "    %+F not taken (dead)\n", node));
 		return loc;
 	}
 
 	loc.time = next_use.time;
 
-	if(next_use.outermost_loop >= get_loop_depth(loop)) {
-		DBG((dbg, DBG_START, "    %+F taken (%u, loop %d)\n", node, loc.time, next_use.outermost_loop));
+	if (improve_known_preds) {
+		if (available == AVAILABLE_EVERYWHERE) {
+			DB((dbg, DBG_START, "    %+F taken (%u, live in all preds)\n",
+			    node, loc.time));
+			return loc;
+		} else if (available == AVAILABLE_NOWHERE) {
+			DB((dbg, DBG_START, "    %+F not taken (%u, live in no pred)\n",
+			    node, loc.time));
+			loc.time = USES_INFINITY;
+			return loc;
+		}
+	}
+
+	if (!respectloopdepth || next_use.outermost_loop >= get_loop_depth(loop)) {
+		DB((dbg, DBG_START, "    %+F taken (%u, loop %d)\n", node, loc.time,
+		    next_use.outermost_loop));
 	} else {
 		loc.time = USES_PENDING;
-		DBG((dbg, DBG_START, "    %+F delayed (outerloopdepth %d < loopdetph %d)\n", node, next_use.outermost_loop, get_loop_depth(loop)));
+		DB((dbg, DBG_START, "    %+F delayed (outerdepth %d < loopdepth %d)\n",
+		    node, next_use.outermost_loop, get_loop_depth(loop)));
 	}
+
 	return loc;
 }
 
-/*
- * Computes set of live-ins for each block with multiple predecessors
- * and notifies spill algorithm which phis need to be spilled
+/**
+ * Computes the start-workset for a block with multiple predecessors. We assume
+ * that at least 1 of the predeccesors is a back-edge which means we're at the
+ * beginning of a loop. We try to reload as much values as possible now so they
+ * don't get reloaded inside the loop.
  */
-static void compute_live_ins(ir_node *block, void *data) {
-	belady_env_t  *env  = data;
-	ir_loop       *loop = get_irn_loop(block);
-	const be_lv_t *lv   = env->lv;
-	block_info_t  *block_info;
-	ir_node       *first, *irn;
-	loc_t         loc, *starters, *delayed;
-	int           i, len, ws_count;
-	int	          free_slots, free_pressure_slots;
-	unsigned      pressure;
-
-	if (get_Block_n_cfgpreds(block) == 1 && get_irg_start_block(get_irn_irg(block)) != block)
-		return;
-
-	block_info = new_block_info(&env->ob);
-	set_block_info(block, block_info);
+static void decide_start_workset(const ir_node *block)
+{
+	ir_loop    *loop = get_irn_loop(block);
+	ir_node    *first;
+	loc_t       loc;
+	loc_t      *starters;
+	loc_t      *delayed;
+	unsigned    len;
+	unsigned    i;
+	unsigned    ws_count;
+	int         free_slots, free_pressure_slots;
+	unsigned    pressure;
+	int         arity;
+	workset_t **pred_worksets;
+	bool        all_preds_known;
+
+	/* check predecessors */
+	arity           = get_irn_arity(block);
+	pred_worksets   = ALLOCAN(workset_t*, arity);
+	all_preds_known = true;
+	for (int in = 0; in < arity; ++in) {
+		ir_node      *pred_block = get_Block_cfgpred_block(block, in);
+		block_info_t *pred_info  = get_block_info(pred_block);
+
+		if (pred_info == NULL) {
+			pred_worksets[in] = NULL;
+			all_preds_known   = false;
+		} else {
+			pred_worksets[in] = pred_info->end_workset;
+		}
+	}
 
 	/* Collect all values living at start of block */
 	starters = NEW_ARR_F(loc_t, 0);
 	delayed  = NEW_ARR_F(loc_t, 0);
 
-	DBG((dbg, DBG_START, "Living at start of %+F:\n", block));
+	DB((dbg, DBG_START, "Living at start of %+F:\n", block));
 	first = sched_first(block);
 
 	/* check all Phis first */
-	sched_foreach(block, irn) {
-		if (! is_Phi(irn))
+	sched_foreach(block, node) {
+		unsigned available;
+
+		if (! is_Phi(node))
 			break;
+		if (!arch_irn_consider_in_reg_alloc(cls, node))
+			continue;
+
+		if (all_preds_known) {
+			available = available_in_all_preds(pred_worksets, arity, node, true);
+		} else {
+			available = AVAILABLE_UNKNOWN;
+		}
 
-		loc = to_take_or_not_to_take(env, first, irn, block, loop);
+		loc = to_take_or_not_to_take(first, node, loop, available);
 
 		if (! USES_IS_INFINITE(loc.time)) {
 			if (USES_IS_PENDING(loc.time))
@@ -422,15 +593,20 @@ static void compute_live_ins(ir_node *block, void *data) {
 			else
 				ARR_APP1(loc_t, starters, loc);
 		} else {
-			be_spill_phi(env->senv, irn);
+			be_spill_phi(senv, node);
 		}
 	}
 
 	/* check all Live-Ins */
-	be_lv_foreach(lv, block, be_lv_state_in, i) {
-		ir_node *node = be_lv_get_irn(lv, block, i);
+	be_lv_foreach_cls(lv, block, be_lv_state_in, cls, node) {
+		unsigned available;
+		if (all_preds_known) {
+			available = available_in_all_preds(pred_worksets, arity, node, false);
+		} else {
+			available = AVAILABLE_UNKNOWN;
+		}
 
-		loc = to_take_or_not_to_take(env, first, node, block, loop);
+		loc = to_take_or_not_to_take(first, node, loop, available);
 
 		if (! USES_IS_INFINITE(loc.time)) {
 			if (USES_IS_PENDING(loc.time))
@@ -440,14 +616,65 @@ static void compute_live_ins(ir_node *block, void *data) {
 		}
 	}
 
-	pressure            = be_get_loop_pressure(env->loop_ana, env->cls, loop);
-	free_slots          = env->n_regs - ARR_LEN(starters);
-	free_pressure_slots = env->n_regs - pressure;
+	pressure            = be_get_loop_pressure(loop_ana, cls, loop);
+	assert(ARR_LEN(delayed) <= pressure);
+	free_slots          = n_regs - ARR_LEN(starters);
+	free_pressure_slots = n_regs - (pressure - ARR_LEN(delayed));
 	free_slots          = MIN(free_slots, free_pressure_slots);
-	/* append nodes delayed due to loop structure until start set is full */
-	for (i = 0; i < ARR_LEN(delayed) && i < free_slots; ++i) {
-		DBG((dbg, DBG_START, "    delayed %+F taken\n", delayed[i].irn));
-		ARR_APP1(loc_t, starters, delayed[i]);
+
+	/* so far we only put nodes into the starters list that are used inside
+	 * the loop. If register pressure in the loop is low then we can take some
+	 * values and let them live through the loop */
+	DB((dbg, DBG_START, "Loop pressure %d, taking %d delayed vals\n",
+	    pressure, free_slots));
+	if (free_slots > 0) {
+		size_t i;
+
+		qsort(delayed, ARR_LEN(delayed), sizeof(delayed[0]), loc_compare);
+
+		for (i = 0; i < ARR_LEN(delayed) && free_slots > 0; ++i) {
+			int    p, arity;
+			loc_t *loc = & delayed[i];
+
+			if (!is_Phi(loc->node)) {
+				/* don't use values which are dead in a known predecessors
+				 * to not induce unnecessary reloads */
+				arity = get_irn_arity(block);
+				for (p = 0; p < arity; ++p) {
+					ir_node      *pred_block = get_Block_cfgpred_block(block, p);
+					block_info_t *pred_info  = get_block_info(pred_block);
+
+					if (pred_info == NULL)
+						continue;
+
+					if (!workset_contains(pred_info->end_workset, loc->node)) {
+						DB((dbg, DBG_START,
+							"    delayed %+F not live at pred %+F\n", loc->node,
+							pred_block));
+						goto skip_delayed;
+					}
+				}
+			}
+
+			DB((dbg, DBG_START, "    delayed %+F taken\n", loc->node));
+			ARR_APP1(loc_t, starters, *loc);
+			loc->node = NULL;
+			--free_slots;
+		skip_delayed:
+			;
+		}
+	}
+
+	/* spill phis (the actual phis not just their values) that are in this block
+	 * but not in the start workset */
+	len = ARR_LEN(delayed);
+	for (i = 0; i < len; ++i) {
+		ir_node *node = delayed[i].node;
+		if (node == NULL || !is_Phi(node) || get_nodes_block(node) != block)
+			continue;
+
+		DB((dbg, DBG_START, "    spilling delayed phi %+F\n", node));
+		be_spill_phi(senv, node);
 	}
 	DEL_ARR_F(delayed);
 
@@ -455,141 +682,158 @@ static void compute_live_ins(ir_node *block, void *data) {
 	qsort(starters, ARR_LEN(starters), sizeof(starters[0]), loc_compare);
 
 	/* Copy the best ones from starters to start workset */
-	ws_count             = MIN(ARR_LEN(starters), env->n_regs);
-	block_info->ws_start = new_workset(env, &env->ob);
-	workset_bulk_fill(block_info->ws_start, ws_count, starters);
+	ws_count = MIN((unsigned) ARR_LEN(starters), n_regs);
+	workset_clear(ws);
+	workset_bulk_fill(ws, ws_count, starters);
 
-	/* The phis of this block which are not in the start set have to be spilled later. */
+	/* spill phis (the actual phis not just their values) that are in this block
+	 * but not in the start workset */
 	len = ARR_LEN(starters);
 	for (i = ws_count; i < len; ++i) {
-		irn = starters[i].irn;
-		if (! is_Phi(irn) || get_nodes_block(irn) != block)
+		ir_node *node = starters[i].node;
+		if (! is_Phi(node) || get_nodes_block(node) != block)
 			continue;
 
-		be_spill_phi(env->senv, irn);
+		DB((dbg, DBG_START, "    spilling phi %+F\n", node));
+		be_spill_phi(senv, node);
 	}
 
 	DEL_ARR_F(starters);
-}
 
-/**
- * Collects all values live-in at block @p block and all phi results in this block.
- * Then it adds the best values (at most n_regs) to the blocks start_workset.
- * The phis among the remaining values get spilled: Introduce psudo-copies of
- *  their args to break interference and make it possible to spill them to the
- *  same spill slot.
- */
-static block_info_t *compute_block_start_info(belady_env_t *env, ir_node *block) {
-	ir_node *pred_block;
-	block_info_t *res, *pred_info;
-
-	/* Have we seen this block before? */
-	res = get_block_info(block);
-	if (res)
-		return res;
-
-	/* Create the block info for this block. */
-	res = new_block_info(&env->ob);
-	set_block_info(block, res);
-
-	/* Use endset of predecessor block as startset */
-	assert(get_Block_n_cfgpreds(block) == 1 && block != get_irg_start_block(get_irn_irg(block)));
-	pred_block = get_Block_cfgpred_block(block, 0);
-	pred_info = get_block_info(pred_block);
-
-	/* if pred block has not been processed yet, do it now */
-	if (pred_info == NULL || pred_info->processed == 0) {
-		belady(pred_block, env);
-		pred_info = get_block_info(pred_block);
-	}
+	/* determine spill status of the values: If there's 1 pred block (which
+	 * is no backedge) where the value is spilled then we must set it to
+	 * spilled here. */
+	for (i = 0; i < ws_count; ++i) {
+		loc_t   *loc     = &ws->vals[i];
+		ir_node *value   = loc->node;
+		bool     spilled;
+		int      n;
+
+		/* phis from this block aren't spilled */
+		if (get_nodes_block(value) == block) {
+			assert(is_Phi(value));
+			loc->spilled = false;
+			continue;
+		}
 
-	/* now we have an end_set of pred */
-	assert(pred_info->ws_end && "The recursive call (above) is supposed to compute an end_set");
-	res->ws_start = workset_clone(env, &env->ob, pred_info->ws_end);
+		/* determine if value was spilled on any predecessor */
+		spilled = false;
+		for (n = 0; n < arity; ++n) {
+			workset_t *pred_workset = pred_worksets[n];
+			int        p_len;
+			int        p;
 
-	return res;
-}
+			if (pred_workset == NULL)
+				continue;
+
+			p_len = workset_get_length(pred_workset);
+			for (p = 0; p < p_len; ++p) {
+				loc_t *l = &pred_workset->vals[p];
+
+				if (l->node != value)
+					continue;
+
+				if (l->spilled) {
+					spilled = true;
+				}
+				break;
+			}
+		}
 
+		loc->spilled = spilled;
+	}
+}
 
 /**
  * For the given block @p block, decide for each values
  * whether it is used from a register or is reloaded
  * before the use.
  */
-static void belady(ir_node *block, void *data) {
-	belady_env_t *env = data;
-	workset_t *new_vals;
-	ir_node *irn;
-	int iter;
+static void process_block(ir_node *block)
+{
+	workset_t    *new_vals;
+	unsigned      iter;
 	block_info_t *block_info;
+	int           arity;
+
+	/* no need to process a block twice */
+	assert(get_block_info(block) == NULL);
+
+	/* construct start workset */
+	arity = get_Block_n_cfgpreds(block);
+	if (arity == 0) {
+		/* no predecessor -> empty set */
+		workset_clear(ws);
+	} else if (arity == 1) {
+		/* one predecessor, copy its end workset */
+		ir_node      *pred_block = get_Block_cfgpred_block(block, 0);
+		block_info_t *pred_info  = get_block_info(pred_block);
+
+		assert(pred_info != NULL);
+		workset_copy(ws, pred_info->end_workset);
+	} else {
+		/* multiple predecessors, do more advanced magic :) */
+		decide_start_workset(block);
+	}
 
-	/* make sure we have blockinfo (with startset) */
-	block_info = get_block_info(block);
-	if (block_info == NULL)
-		block_info = compute_block_start_info(env, block);
+	DB((dbg, DBG_DECIDE, "\n"));
+	DB((dbg, DBG_DECIDE, "Decide for %+F\n", block));
 
-	/* Don't do a block twice */
-	if(block_info->processed)
-		return;
+	block_info = new_block_info();
+	set_block_info(block, block_info);
 
-	/* get the starting workset for this block */
-	DBG((dbg, DBG_DECIDE, "\n"));
-	DBG((dbg, DBG_DECIDE, "Decide for %+F\n", block));
+	DB((dbg, DBG_WSETS, "Start workset for %+F:\n", block));
+	{
+		ir_node *irn;
+		workset_foreach(ws, irn, iter) {
+			DB((dbg, DBG_WSETS, "  %+F (%u)\n", irn, workset_get_time(ws, iter)));
+		}
+	}
 
-	workset_copy(env, env->ws, block_info->ws_start);
-	DBG((dbg, DBG_WSETS, "Start workset for %+F:\n", block));
-	workset_foreach(env->ws, irn, iter)
-		DBG((dbg, DBG_WSETS, "  %+F (%u)\n", irn, workset_get_time(env->ws, iter)));
+	block_info->start_workset = workset_clone(ws);
 
 	/* process the block from start to end */
-	DBG((dbg, DBG_WSETS, "Processing...\n"));
-	env->used = pset_new_ptr_default();
-	env->instr_nr = 0;
-	new_vals = new_workset(env, &env->ob);
+	DB((dbg, DBG_WSETS, "Processing...\n"));
+	/* TODO: this leaks (into the obstack)... */
+	new_vals = new_workset();
+
 	sched_foreach(block, irn) {
-		int i, arity;
-		assert(workset_get_length(env->ws) <= env->n_regs && "Too much values in workset!");
-
-		/* projs are handled with the tuple value.
-		 * Phis are no real instr (see insert_starters())
-		 * instr_nr does not increase */
-		if (is_Proj(irn) || is_Phi(irn)) {
-			DBG((dbg, DBG_DECIDE, "  ...%+F skipped\n", irn));
+		assert(workset_get_length(ws) <= n_regs);
+
+		/* Phis are no real instr (see insert_starters()) */
+		if (is_Phi(irn)) {
 			continue;
 		}
-		DBG((dbg, DBG_DECIDE, "  ...%+F\n", irn));
+		DB((dbg, DBG_DECIDE, "  ...%+F\n", irn));
 
 		/* set instruction in the workset */
-		env->instr = irn;
+		instr = irn;
 
 		/* allocate all values _used_ by this instruction */
 		workset_clear(new_vals);
-		for(i = 0, arity = get_irn_arity(irn); i < arity; ++i) {
-			workset_insert(env, new_vals, get_irn_n(irn, i));
-		}
-		displace(env, new_vals, 1);
+		be_foreach_use(irn, cls, in_req_, in, in_req,
+			/* (note that "spilled" is irrelevant here) */
+			workset_insert(new_vals, in, false);
+		);
+		displace(new_vals, 1);
 
 		/* allocate all values _defined_ by this instruction */
 		workset_clear(new_vals);
-		if (get_irn_mode(irn) == mode_T) { /* special handling for tuples and projs */
-			ir_node *proj;
-			for(proj=sched_next(irn); is_Proj(proj); proj=sched_next(proj))
-				workset_insert(env, new_vals, proj);
-		} else {
-			workset_insert(env, new_vals, irn);
-		}
-		displace(env, new_vals, 0);
-
-		env->instr_nr++;
+		be_foreach_definition(irn, cls, value, req,
+			assert(req->width == 1);
+			workset_insert(new_vals, value, false);
+		);
+		displace(new_vals, 0);
 	}
-	del_pset(env->used);
 
 	/* Remember end-workset for this block */
-	block_info->ws_end = workset_clone(env, &env->ob, env->ws);
-	block_info->processed = 1;
-	DBG((dbg, DBG_WSETS, "End workset for %+F:\n", block));
-	workset_foreach(block_info->ws_end, irn, iter)
-		DBG((dbg, DBG_WSETS, "  %+F (%u)\n", irn, workset_get_time(block_info->ws_end, iter)));
+	block_info->end_workset = workset_clone(ws);
+	DB((dbg, DBG_WSETS, "End workset for %+F:\n", block));
+	{
+		ir_node *irn;
+		workset_foreach(ws, irn, iter)
+			DB((dbg, DBG_WSETS, "  %+F (%u)\n", irn, workset_get_time(ws, iter)));
+	}
 }
 
 /**
@@ -597,119 +841,169 @@ static void belady(ir_node *block, void *data) {
  * about the set of live-ins. Thus we must adapt the
  * live-outs to the live-ins at each block-border.
  */
-static void fix_block_borders(ir_node *block, void *data) {
-	belady_env_t *env = data;
-	workset_t *wsb;
-        ir_graph *irg = get_irn_irg(block);
-        ir_node *startblock = get_irg_start_block(irg);
-	int i, max, iter, iter2;
+static void fix_block_borders(ir_node *block, void *data)
+{
+	workset_t *start_workset;
+	int        arity;
+	int        i;
+	unsigned   iter;
+	(void) data;
+
+	DB((dbg, DBG_FIX, "\n"));
+	DB((dbg, DBG_FIX, "Fixing %+F\n", block));
+
+	arity = get_irn_arity(block);
+	/* can happen for endless loops */
+	if (arity == 0)
+		return;
 
-        if(block == startblock)
-            return;
+	start_workset = get_block_info(block)->start_workset;
 
-	DBG((dbg, DBG_FIX, "\n"));
-	DBG((dbg, DBG_FIX, "Fixing %+F\n", block));
+	/* process all pred blocks */
+	for (i = 0; i < arity; ++i) {
+		ir_node   *pred = get_Block_cfgpred_block(block, i);
+		workset_t *pred_end_workset = get_block_info(pred)->end_workset;
+		ir_node   *node;
+
+		DB((dbg, DBG_FIX, "  Pred %+F\n", pred));
+
+		/* spill all values not used anymore */
+		workset_foreach(pred_end_workset, node, iter) {
+			ir_node *n2;
+			unsigned iter2;
+			bool     found = false;
+			workset_foreach(start_workset, n2, iter2) {
+				if (n2 == node) {
+					found = true;
+					break;
+				}
+				/* note that we do not look at phi inputs, becuase the values
+				 * will be either live-end and need no spill or
+				 * they have other users in which must be somewhere else in the
+				 * workset */
+			}
 
-	wsb = get_block_info(block)->ws_start;
+			if (found)
+				continue;
 
-	/* process all pred blocks */
-	for (i=0, max=get_irn_arity(block); i<max; ++i) {
-		ir_node *irnb, *irnp, *pred = get_Block_cfgpred_block(block, i);
-		workset_t *wsp = get_block_info(pred)->ws_end;
+			if (move_spills && be_is_live_in(lv, block, node)
+					&& !pred_end_workset->vals[iter].spilled) {
+				ir_node *insert_point;
+				if (arity > 1) {
+					insert_point = be_get_end_of_block_insertion_point(pred);
+					insert_point = sched_prev(insert_point);
+				} else {
+					insert_point = block;
+				}
+				DB((dbg, DBG_SPILL, "Spill %+F after %+F\n", node,
+				     insert_point));
+				be_add_spill(senv, node, insert_point);
+			}
+		}
 
-		DBG((dbg, DBG_FIX, "  Pred %+F\n", pred));
+		/* reload missing values in predecessors, add missing spills */
+		workset_foreach(start_workset, node, iter) {
+			const loc_t *l    = &start_workset->vals[iter];
+			const loc_t *pred_loc;
 
-		workset_foreach(wsb, irnb, iter) {
-			/* if irnb is a phi of the current block we reload
-			 * the corresponding argument, else irnb itself */
-			if(is_Phi(irnb) && block == get_nodes_block(irnb)) {
-				irnb = get_irn_n(irnb, i);
+			/* if node is a phi of the current block we reload
+			 * the corresponding argument, else node itself */
+			if (is_Phi(node) && get_nodes_block(node) == block) {
+				node = get_irn_n(node, i);
+				assert(!l->spilled);
 
-				// we might have unknowns as argument for the phi
-				if(!arch_irn_consider_in_reg_alloc(env->arch, env->cls, irnb))
+				/* we might have unknowns as argument for the phi */
+				if (!arch_irn_consider_in_reg_alloc(cls, node))
 					continue;
 			}
 
-			/* Unknowns are available everywhere */
-			if(get_irn_opcode(irnb) == iro_Unknown)
-				continue;
-
-			/* check if irnb is in a register at end of pred */
-			workset_foreach(wsp, irnp, iter2) {
-				if (irnb == irnp)
-					goto next_value;
+			/* check if node is in a register at end of pred */
+			pred_loc = workset_contains(pred_end_workset, node);
+			if (pred_loc != NULL) {
+				/* we might have to spill value on this path */
+				if (move_spills && !pred_loc->spilled && l->spilled) {
+					ir_node *insert_point
+						= be_get_end_of_block_insertion_point(pred);
+					insert_point = sched_prev(insert_point);
+					DB((dbg, DBG_SPILL, "Spill %+F after %+F\n", node,
+					    insert_point));
+					be_add_spill(senv, node, insert_point);
+				}
+			} else {
+				/* node is not in register at the end of pred -> reload it */
+				DB((dbg, DBG_FIX, "    reload %+F\n", node));
+				DB((dbg, DBG_SPILL, "Reload %+F before %+F,%d\n", node, block, i));
+				be_add_reload_on_edge(senv, node, block, i, cls, 1);
 			}
-
-			/* irnb is not in memory at the end of pred, so we have to reload it */
-			DBG((dbg, DBG_FIX, "    reload %+F\n", irnb));
-			DBG((dbg, DBG_SPILL, "Reload %+F before %+F,%d\n", irnb, block, i));
-			be_add_reload_on_edge(env->senv, irnb, block, i, env->cls, 1);
-
-next_value:
-			/*epsilon statement :)*/;
 		}
 	}
 }
 
-void be_spill_belady(be_irg_t *birg, const arch_register_class_t *cls) {
-	be_spill_belady_spill_env(birg, cls, NULL);
-}
+static void be_spill_belady(ir_graph *irg, const arch_register_class_t *rcls)
+{
+	int i;
 
-void be_spill_belady_spill_env(be_irg_t *birg, const arch_register_class_t *cls, spill_env_t *spill_env) {
-	belady_env_t env;
-	ir_graph *irg = be_get_birg_irg(birg);
+	be_assure_live_sets(irg);
 
-	FIRM_DBG_REGISTER(dbg, "firm.be.spill.belady");
-	//firm_dbg_set_mask(dbg, DBG_SPILL);
+	stat_ev_tim_push();
+	assure_loopinfo(irg);
+	stat_ev_tim_pop("belady_time_backedges");
 
-	be_invalidate_liveness(birg);
-	be_assure_liveness(birg);
-	/* construct control flow loop tree */
-	if(! (get_irg_loopinfo_state(irg) & loopinfo_cf_consistent)) {
-		construct_cf_backedges(irg);
-	}
+	stat_ev_tim_push();
+	be_clear_links(irg);
+	stat_ev_tim_pop("belady_time_clear_links");
+
+	ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
 
 	/* init belady env */
-	obstack_init(&env.ob);
-	env.arch      = birg->main_env->arch_env;
-	env.cls       = cls;
-	env.lv        = be_get_birg_liveness(birg);
-	env.n_regs    = env.cls->n_regs - be_put_ignore_regs(birg, cls, NULL);
-	env.ws        = new_workset(&env, &env.ob);
-	env.uses      = be_begin_uses(irg, env.lv);
-	env.loop_ana  = be_new_loop_pressure(birg);
-	if(spill_env == NULL) {
-		env.senv = be_new_spill_env(birg);
-	} else {
-		env.senv = spill_env;
+	stat_ev_tim_push();
+	obstack_init(&obst);
+	cls       = rcls;
+	lv        = be_get_irg_liveness(irg);
+	n_regs    = be_get_n_allocatable_regs(irg, cls);
+	ws        = new_workset();
+	uses      = be_begin_uses(irg, lv);
+	loop_ana  = be_new_loop_pressure(irg, cls);
+	senv      = be_new_spill_env(irg);
+	blocklist = be_get_cfgpostorder(irg);
+	stat_ev_tim_pop("belady_time_init");
+
+	stat_ev_tim_push();
+	/* walk blocks in reverse postorder */
+	for (i = ARR_LEN(blocklist) - 1; i >= 0; --i) {
+		process_block(blocklist[i]);
 	}
-	DEBUG_ONLY(be_set_spill_env_dbg_module(env.senv, dbg);)
+	DEL_ARR_F(blocklist);
+	stat_ev_tim_pop("belady_time_belady");
+
+	stat_ev_tim_push();
+	/* belady was block-local, fix the global flow by adding reloads on the
+	 * edges */
+	irg_block_walk_graph(irg, fix_block_borders, NULL, NULL);
+	stat_ev_tim_pop("belady_time_fix_borders");
+
+	ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
 
-	be_clear_links(irg);
-	/* Decide which phi nodes will be spilled and place copies for them into the graph */
-	irg_block_walk_graph(irg, compute_live_ins, NULL, &env);
-	/* Fix high register pressure with belady algorithm */
-	irg_block_walk_graph(irg, NULL, belady, &env);
-	/* belady was block-local, fix the global flow by adding reloads on the edges */
-	irg_block_walk_graph(irg, fix_block_borders, NULL, &env);
 	/* Insert spill/reload nodes into the graph and fix usages */
-	be_insert_spills_reloads(env.senv);
+	be_insert_spills_reloads(senv);
 
 	/* clean up */
-	if(spill_env == NULL)
-		be_delete_spill_env(env.senv);
-	be_end_uses(env.uses);
-	be_free_loop_pressure(env.loop_ana);
-	obstack_free(&env.ob, NULL);
+	be_delete_spill_env(senv);
+	be_end_uses(uses);
+	be_free_loop_pressure(loop_ana);
+	obstack_free(&obst, NULL);
 }
 
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spillbelady)
 void be_init_spillbelady(void)
 {
 	static be_spiller_t belady_spiller = {
 		be_spill_belady
 	};
+	lc_opt_entry_t *be_grp       = lc_opt_get_grp(firm_opt_get_root(), "be");
+	lc_opt_entry_t *belady_group = lc_opt_get_grp(be_grp, "belady");
+	lc_opt_add_table(belady_group, options);
 
 	be_register_spiller("belady", &belady_spiller);
+	FIRM_DBG_REGISTER(dbg, "firm.be.spill.belady");
 }
-
-BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spillbelady);