X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbecopyheur4.c;h=e7195aa354805856836535bba4017b9d07fc7db0;hb=75e3b5fe17402ca27fc671dd404ff958664506b1;hp=034172f27cafa1d04d278641f99a2972f9f040ee;hpb=de3446f093aa514a51a894e6e345ad5c5ef717b8;p=libfirm

diff --git a/ir/be/becopyheur4.c b/ir/be/becopyheur4.c
index 034172f27..e7195aa35 100644
--- a/ir/be/becopyheur4.c
+++ b/ir/be/becopyheur4.c
@@ -1,11 +1,5 @@
-/**
- * @file       becopyheur4.c
- * @brief      Simple copy minimization heuristics.
- * @author     27.04.2007
- * @version    $Id$
- * @license
- *
- * Copyrigth (C) 1995-2007 University of Karlsruhe.  All right reserved.
+/*
+ * Copyright (C) 1995-2007 University of Karlsruhe.  All right reserved.
  *
  * This file is part of libFirm.
  *
@@ -21,15 +15,20 @@
  * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
  * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE.
- *
- * @summary
+ */
+
+/**
+ * @file
+ * @brief       Simple copy minimization heuristics.
+ * @author      Christian Wuerdig
+ * @date        27.04.2007
+ * @version     $Id$
  *
  * This is the C implementation of the mst algorithm
  * originally written in Java by Sebastian Hack.
  * (also known as "heur3" :)
  * Performs simple copy minimization.
  */
-
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif /* HAVE_CONFIG_H */
@@ -42,23 +41,37 @@
 #include "raw_bitset.h"
 #include "irphase_t.h"
 #include "pqueue.h"
-#include "pset_new.h"
 #include "xmalloc.h"
 #include "pdeq.h"
+#include "pset.h"
 #include "irprintf.h"
+#include "irbitset.h"
+#include "error.h"
+#include "list.h"
 
 #include "bearch.h"
 #include "beifg.h"
 #include "be_t.h"
 #include "becopyopt_t.h"
-#include "irbitset.h"
+#include "bemodule.h"
+
 
 #define COL_COST_INFEASIBLE       DBL_MAX
 #define AFF_NEIGHBOUR_FIX_BENEFIT 128.0
 #define NEIGHBOUR_CONSTR_COSTS    64.0
 
-#define DBG_AFF_CHUNK(env, level, chunk) DEBUG_ONLY(if (firm_dbg_get_mask((env)->dbg) & (level)) dbg_aff_chunk((env), (chunk));)
-#define DBG_COL_COST(env, level, cost)   DEBUG_ONLY(if (firm_dbg_get_mask((env)->dbg) & (level)) dbg_col_cost((env), (cost));)
+#ifdef NDEBUG
+
+#define DBG_AFF_CHUNK(env, level, chunk)
+#define DBG_COL_COST(env, level, cost)
+
+#else
+
+static firm_dbg_module_t *dbg = NULL;
+#define DBG_AFF_CHUNK(env, level, chunk) do { if (firm_dbg_get_mask(dbg) & (level)) dbg_aff_chunk((env), (chunk)); } while(0)
+#define DBG_COL_COST(env, level, cost)   do { if (firm_dbg_get_mask(dbg) & (level)) dbg_col_cost((env), (cost)); } while(0)
+
+#endif
 
 static int last_chunk_id = 0;
 
@@ -67,58 +80,67 @@ typedef struct _col_cost_t {
 	double cost;
 } col_cost_t;
 
+/**
+ * An affinity chunk.
+ */
 typedef struct _aff_chunk_t {
-	bitset_t *nodes;
-	int      weight;
-	unsigned weight_consistent : 1;
-	int      id;
+	ir_node  **n;                   /**< An ARR_F containing all nodes of the chunk. */
+	bitset_t *nodes;                /**< A bitset containing all nodes inside this chunk. */
+	bitset_t *interfere;            /**< A bitset containing all interfering neighbours of the nodes in this chunk. */
+	int      weight;                /**< Weight of this chunk */
+	unsigned weight_consistent : 1; /**< Set if the weight is consistent. */
+	unsigned deleted           : 1; /**< Set if the was deleted. */
+	int      id;                    /**< For debugging: An id of this chunk. */
 } aff_chunk_t;
 
+/**
+ * An affinity edge.
+ */
 typedef struct _aff_edge_t {
-	ir_node *src;
-	ir_node *tgt;
-	double  weight;
+	ir_node *src;                   /**< Source node. */
+	ir_node *tgt;                   /**< Target node. */
+	double  weight;                 /**< The weight of this edge. */
 } aff_edge_t;
 
-/* main coalescing environment*/
+/* main coalescing environment */
 typedef struct _co_mst_env_t {
 	int              n_regs;         /**< number of regs in class */
 	int              k;              /**< number of non-ignore registers in class */
 	bitset_t         *ignore_regs;   /**< set containing all global ignore registers */
 	ir_phase         ph;             /**< phase object holding data for nodes */
 	pqueue           *chunks;        /**< priority queue for chunks */
-	pset_new_t       chunkset;       /**< set holding all chunks */
+	pset             *chunkset;      /**< set holding all chunks */
 	be_ifg_t         *ifg;           /**< the interference graph */
 	const arch_env_t *aenv;          /**< the arch environment */
 	copy_opt_t       *co;            /**< the copy opt object */
-	DEBUG_ONLY(firm_dbg_module_t *dbg);
 } co_mst_env_t;
 
 /* stores coalescing related information for a node */
 typedef struct _co_mst_irn_t {
-	ir_node     *irn;              /**< the irn this information belongs to */
-	aff_chunk_t *chunk;            /**< the chunk this irn belongs to */
-	bitset_t    *adm_colors;       /**< set of admissible colors for this irn */
-	ir_node     **int_neighs;      /**< ARR_D of all interfering neighbours (cached for speed reasons) */
-	int         int_aff_neigh;     /**< number of interfering affinity neighbours */
-	int         col;               /**< color currently assigned */
-	int         init_col;          /**< the initial color */
-	int         tmp_col;           /**< a temporary assigned color */
-	unsigned    fixed     : 1;     /**< the color is fixed */
-	unsigned    tmp_fixed : 1;     /**< the color is temporary fixed */
+	ir_node          *irn;              /**< the irn this information belongs to */
+	aff_chunk_t      *chunk;            /**< the chunk this irn belongs to */
+	bitset_t         *adm_colors;       /**< set of admissible colors for this irn */
+	ir_node          **int_neighs;      /**< array of all interfering neighbours (cached for speed reasons) */
+	int              n_neighs;          /**< length of the interfering neighbours array. */
+	int              int_aff_neigh;     /**< number of interfering affinity neighbours */
+	int              col;               /**< color currently assigned */
+	int              init_col;          /**< the initial color */
+	int              tmp_col;           /**< a temporary assigned color */
+	unsigned         fixed     : 1;     /**< the color is fixed */
+	struct list_head list;              /**< Queue for coloring undo. */
 } co_mst_irn_t;
 
 #define get_co_mst_irn(mst_env, irn) (phase_get_or_set_irn_data(&(mst_env)->ph, (irn)))
 
-typedef int decide_func_t(co_mst_irn_t *node, int col);
+typedef int decide_func_t(const co_mst_irn_t *node, int col);
 
 #ifdef DEBUG_libfirm
 
 /**
  * Write a chunk to stderr for debugging.
  */
-static void dbg_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
-	int idx;
+static void dbg_aff_chunk(const co_mst_env_t *env, const aff_chunk_t *c) {
+	bitset_pos_t idx;
 	if (c->weight_consistent)
 		ir_fprintf(stderr, " $%d ", c->weight);
 	ir_fprintf(stderr, "{");
@@ -132,8 +154,10 @@ static void dbg_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
 /**
  * Dump all admissible colors to stderr.
  */
-static void dbg_admissible_colors(co_mst_env_t *env, co_mst_irn_t *node) {
-	int idx;
+static void dbg_admissible_colors(const co_mst_env_t *env, const co_mst_irn_t *node) {
+	bitset_pos_t idx;
+	(void) env;
+
 	if (bitset_popcnt(node->adm_colors) < 1)
 		fprintf(stderr, "no admissible colors?!?");
 	else {
@@ -145,7 +169,7 @@ static void dbg_admissible_colors(co_mst_env_t *env, co_mst_irn_t *node) {
 /**
  * Dump color-cost pairs to stderr.
  */
-static void dbg_col_cost(co_mst_env_t *env, col_cost_t *cost) {
+static void dbg_col_cost(const co_mst_env_t *env, const col_cost_t *cost) {
 	int i;
 	for (i = 0; i < env->n_regs; ++i) {
 		if (cost[i].cost == COL_COST_INFEASIBLE)
@@ -157,32 +181,34 @@ static void dbg_col_cost(co_mst_env_t *env, col_cost_t *cost) {
 
 #endif /* DEBUG_libfirm */
 
-static INLINE int get_mst_irn_col(co_mst_irn_t *node) {
-	return node->tmp_fixed ? node->tmp_col : node->col;
+static INLINE int get_mst_irn_col(const co_mst_irn_t *node) {
+	return node->tmp_col >= 0 ? node->tmp_col : node->col;
 }
 
 /**
  * @return 1 if node @p node has color @p col, 0 otherwise.
  */
-static int decider_has_color(co_mst_irn_t *node, int col) {
+static int decider_has_color(const co_mst_irn_t *node, int col) {
 	return get_mst_irn_col(node) == col;
 }
 
 /**
  * @return 1 if node @p node has not color @p col, 0 otherwise.
  */
-static int decider_hasnot_color(co_mst_irn_t *node, int col) {
+static int decider_hasnot_color(const co_mst_irn_t *node, int col) {
 	return get_mst_irn_col(node) != col;
 }
 
 /**
  * Always returns true.
  */
-static int decider_always_yes(co_mst_irn_t *node, int col) {
+static int decider_always_yes(const co_mst_irn_t *node, int col) {
+	(void) node;
+	(void) col;
 	return 1;
 }
 
-/* > compares two affinity edges by its weight */
+/** compares two affinity edges by its weight */
 static int cmp_aff_edge(const void *a, const void *b) {
 	const aff_edge_t *e1 = a;
 	const aff_edge_t *e2 = b;
@@ -197,7 +223,7 @@ static int cmp_aff_edge(const void *a, const void *b) {
 	return QSORT_CMP(e2->weight, e1->weight);
 }
 
-/* compares to color-cost pairs */
+/** compares to color-cost pairs */
 static int cmp_col_cost(const void *a, const void *b) {
 	const col_cost_t *c1 = a;
 	const col_cost_t *c2 = b;
@@ -212,9 +238,11 @@ static INLINE aff_chunk_t *new_aff_chunk(co_mst_env_t *env) {
 	aff_chunk_t *c = xmalloc(sizeof(*c));
 	c->weight            = -1;
 	c->weight_consistent = 0;
+	c->n                 = NEW_ARR_F(ir_node *, 0);
 	c->nodes             = bitset_irg_malloc(env->co->irg);
+	c->interfere         = bitset_irg_malloc(env->co->irg);
 	c->id                = last_chunk_id++;
-	pset_new_insert(&env->chunkset, c);
+	pset_insert(env->chunkset, c, c->id);
 	return c;
 }
 
@@ -222,8 +250,11 @@ static INLINE aff_chunk_t *new_aff_chunk(co_mst_env_t *env) {
  * Frees all memory allocated by an affinity chunk.
  */
 static INLINE void delete_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
-	pset_new_remove(&env->chunkset, c);
+	pset_remove(env->chunkset, c, c->id);
 	bitset_free(c->nodes);
+	bitset_free(c->interfere);
+	DEL_ARR_F(c->n);
+	c->deleted = 1;
 	free(c);
 }
 
@@ -231,9 +262,21 @@ static INLINE void delete_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
  * Adds a node to an affinity chunk
  */
 static INLINE void aff_chunk_add_node(aff_chunk_t *c, co_mst_irn_t *node) {
+	int i;
+
+	if (bitset_is_set(c->nodes, get_irn_idx(node->irn)))
+		return;
+
 	c->weight_consistent = 0;
 	node->chunk          = c;
 	bitset_set(c->nodes, get_irn_idx(node->irn));
+
+	ARR_APP1(ir_node *, c->n, node->irn);
+
+	for (i = node->n_neighs - 1; i >= 0; --i) {
+		ir_node *neigh = node->int_neighs[i];
+		bitset_set(c->interfere, get_irn_idx(neigh));
+	}
 }
 
 /**
@@ -250,19 +293,16 @@ static void *co_mst_irn_init(ir_phase *ph, ir_node *irn, void *old) {
 		unsigned len;
 
 		res->irn           = irn;
-		res->chunk         = new_aff_chunk(env);
+		res->chunk         = NULL;
 		res->fixed         = 0;
-		res->tmp_fixed     = 0;
 		res->tmp_col       = -1;
 		res->int_neighs    = NULL;
 		res->int_aff_neigh = 0;
 		res->col           = arch_register_get_index(arch_get_irn_register(env->aenv, irn));
 		res->init_col      = res->col;
+		INIT_LIST_HEAD(&res->list);
 
-		/* add note to new chunk */
-		aff_chunk_add_node(res->chunk, res);
-
-		DB((env->dbg, LEVEL_4, "Creating phase info for %+F, chunk %d\n", irn, res->chunk->id));
+		DB((dbg, LEVEL_4, "Creating phase info for %+F\n", irn));
 
 		/* set admissible registers */
 		res->adm_colors = bitset_obstack_alloc(phase_obst(ph), env->n_regs);
@@ -282,13 +322,14 @@ static void *co_mst_irn_init(ir_phase *ph, ir_node *irn, void *old) {
 
 		/* build list of interfering neighbours */
 		len = 0;
-		/* count them first as an obstack array cannot be extended */
-		be_ifg_foreach_neighbour(env->ifg, nodes_it, irn, neigh)
-			len++;
-		res->int_neighs = NEW_ARR_D(ir_node *, phase_obst(ph), len);
-		len = 0;
-		be_ifg_foreach_neighbour(env->ifg, nodes_it, irn, neigh)
-			res->int_neighs[len++] = neigh;
+		be_ifg_foreach_neighbour(env->ifg, nodes_it, irn, neigh) {
+			if (! arch_irn_is(env->aenv, neigh, ignore)) {
+				obstack_ptr_grow(phase_obst(ph), neigh);
+				++len;
+			}
+		}
+		res->int_neighs = obstack_finish(phase_obst(ph));
+		res->n_neighs   = len;
 	}
 	return res;
 }
@@ -296,18 +337,9 @@ static void *co_mst_irn_init(ir_phase *ph, ir_node *irn, void *old) {
 /**
  * Check if affinity chunk @p chunk interferes with node @p irn.
  */
-static INLINE int aff_chunk_interferes(co_mst_env_t *env, aff_chunk_t *chunk, ir_node *irn) {
-	co_mst_irn_t *node = get_co_mst_irn(env, irn);
-	ir_node      *neigh;
-	int          i;
-
-	for (i = 0; i < ARR_LEN(node->int_neighs); ++i) {
-		neigh = node->int_neighs[i];
-		if (! arch_irn_is(env->aenv, neigh, ignore) && bitset_is_set(chunk->nodes, get_irn_idx(neigh)))
-			return 1;
-	}
-
-	return 0;
+static INLINE int aff_chunk_interferes(co_mst_env_t *env, const aff_chunk_t *chunk, ir_node *irn) {
+	(void) env;
+	return bitset_is_set(chunk->interfere, get_irn_idx(irn));
 }
 
 /**
@@ -317,82 +349,129 @@ static INLINE int aff_chunk_interferes(co_mst_env_t *env, aff_chunk_t *chunk, ir
  * @param c2    Another chunk
  * @return 1 if there are interferences between nodes of c1 and c2, 0 otherwise.
  */
-static INLINE int aff_chunks_interfere(co_mst_env_t *env, aff_chunk_t *c1, aff_chunk_t *c2) {
-	int idx;
+static INLINE int aff_chunks_interfere(co_mst_env_t *env, const aff_chunk_t *c1, const aff_chunk_t *c2) {
+	bitset_t *tmp;
 
 	if (c1 == c2)
 		return 0;
 
 	/* check if there is a node in c2 having an interfering neighbor in c1 */
-	bitset_foreach(c2->nodes, idx) {
-		ir_node *n = get_idx_irn(env->co->irg, idx);
+	tmp = bitset_alloca(get_irg_last_idx(env->co->irg));
+	tmp = bitset_copy(tmp, c1->interfere);
+	tmp = bitset_and(tmp, c2->nodes);
 
-		if (aff_chunk_interferes(env, c1, n))
-			return 1;
-	}
+	return bitset_popcnt(tmp) > 0;
+}
 
-	return 0;
+/**
+ * Returns the affinity chunk of @p irn or creates a new
+ * one with @p irn as element if there is none assigned.
+ */
+static INLINE aff_chunk_t *get_aff_chunk(co_mst_env_t *env, ir_node *irn) {
+	co_mst_irn_t *node = get_co_mst_irn(env, irn);
+	return node->chunk;
 }
 
 /**
- * Let c1 absorb the nodes of c2 (only possible when there
- * are no interference edges from c1 to c2).
+ * Let chunk(src) absorb the nodes of chunk(tgt) (only possible when there
+ * are no interference edges from chunk(src) to chunk(tgt)).
  * @return 1 if successful, 0 if not possible
  */
-static int aff_chunk_absorb(co_mst_env_t *env, aff_chunk_t *c1, aff_chunk_t *c2) {
-	DB((env->dbg, LEVEL_4, "Attempt to let c1 (id %d): ", c1->id));
-	DBG_AFF_CHUNK(env, LEVEL_4, c1);
-	DB((env->dbg, LEVEL_4, "\n\tabsorb c2 (id %d): ", c2->id));
-	DBG_AFF_CHUNK(env, LEVEL_4, c2);
-	DB((env->dbg, LEVEL_4, "\n"));
+static int aff_chunk_absorb(co_mst_env_t *env, ir_node *src, ir_node *tgt) {
+	aff_chunk_t *c1 = get_aff_chunk(env, src);
+	aff_chunk_t *c2 = get_aff_chunk(env, tgt);
+
+#ifndef NDEBUG
+		DB((dbg, LEVEL_4, "Attempt to let c1 (id %d): ", c1 ? c1->id : -1));
+		if (c1) {
+			DBG_AFF_CHUNK(env, LEVEL_4, c1);
+		} else {
+			DB((dbg, LEVEL_4, "{%+F}", src));
+		}
+		DB((dbg, LEVEL_4, "\n\tabsorb c2 (id %d): ", c2 ? c2->id : -1));
+		if (c2) {
+			DBG_AFF_CHUNK(env, LEVEL_4, c2);
+		} else {
+			DB((dbg, LEVEL_4, "{%+F}", tgt));
+		}
+		DB((dbg, LEVEL_4, "\n"));
+#endif
 
-	if (c1 != c2 && ! aff_chunks_interfere(env, c1, c2)) {
-		int idx;
+	if (c1 == NULL) {
+		if (c2 == NULL) {
+			/* no chunk exists */
+			co_mst_irn_t *mirn = get_co_mst_irn(env, src);
+			int i;
 
-		bitset_or(c1->nodes, c2->nodes);
-		c1->weight_consistent = 0;
+			for (i = mirn->n_neighs - 1; i >= 0; --i) {
+				if (mirn->int_neighs[i] == tgt)
+					break;
+			}
+			if (i < 0) {
+				/* create one containing both nodes */
+				c1 = new_aff_chunk(env);
+				aff_chunk_add_node(c1, get_co_mst_irn(env, src));
+				aff_chunk_add_node(c1, get_co_mst_irn(env, tgt));
+				goto absorbed;
+			}
+		} else {
+			/* c2 already exists */
+			if (! aff_chunk_interferes(env, c2, src)) {
+				aff_chunk_add_node(c2, get_co_mst_irn(env, src));
+				goto absorbed;
+			}
+		}
+	} else if (c2 == NULL) {
+		/* c1 already exists */
+		if (! aff_chunk_interferes(env, c1, tgt)) {
+			aff_chunk_add_node(c1, get_co_mst_irn(env, tgt));
+			goto absorbed;
+		}
+	} else if (c1 != c2 && ! aff_chunks_interfere(env, c1, c2)) {
+		int idx, len;
 
-		bitset_foreach(c2->nodes, idx) {
-			ir_node      *n  = get_idx_irn(env->co->irg, idx);
+		for (idx = 0, len = ARR_LEN(c2->n); idx < len; ++idx) {
+			ir_node      *n  = c2->n[idx];
 			co_mst_irn_t *mn = get_co_mst_irn(env, n);
+
 			mn->chunk = c1;
+
+			if (! bitset_is_set(c1->nodes, get_irn_idx(n)))
+				ARR_APP1(ir_node *, c1->n, n);
 		}
 
-		DB((env->dbg, LEVEL_4, " ... absorbed, c2 deleted\n"));
+		bitset_or(c1->nodes, c2->nodes);
+		bitset_or(c1->interfere, c2->interfere);
+		c1->weight_consistent = 0;
+
 		delete_aff_chunk(env, c2);
-		return 1;
+		goto absorbed;
 	}
-	DB((env->dbg, LEVEL_4, " ... c1 interferes with c2, skipped\n"));
+	DB((dbg, LEVEL_4, " ... c1 interferes with c2, skipped\n"));
 	return 0;
-}
 
-/**
- * Returns the affinity chunk of @p irn or creates a new
- * one with @p irn as element if there is none assigned.
- */
-static INLINE aff_chunk_t *get_aff_chunk(co_mst_env_t *env, ir_node *irn) {
-	co_mst_irn_t *node = get_co_mst_irn(env, irn);
-	assert(node->chunk && "Node should have a chunk.");
-	return node->chunk;
+absorbed:
+	DB((dbg, LEVEL_4, " ... absorbed\n"));
+	return 1;
 }
 
 /**
  * Assures that the weight of the given chunk is consistent.
  */
-static void aff_chunk_assure_weight(co_mst_env_t *env, aff_chunk_t *c) {
+static void aff_chunk_assure_weight(const co_mst_env_t *env, aff_chunk_t *c) {
 	if (! c->weight_consistent) {
 		int w = 0;
-		int idx;
+		int idx, len;
 
-		bitset_foreach(c->nodes, idx) {
-			ir_node         *n  = get_idx_irn(env->co->irg, idx);
-			affinity_node_t *an = get_affinity_info(env->co, n);
+		for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
+			ir_node               *n  = c->n[idx];
+			const affinity_node_t *an = get_affinity_info(env->co, n);
 
 			if (an != NULL) {
 				neighb_t *neigh;
 				co_gs_foreach_neighb(an, neigh) {
-					ir_node      *m    = neigh->irn;
-					int          m_idx = get_irn_idx(m);
+					const ir_node *m    = neigh->irn;
+					const int     m_idx = get_irn_idx(m);
 
 					/* skip ignore nodes */
 					if (arch_irn_is(env->aenv, m, ignore))
@@ -411,22 +490,22 @@ static void aff_chunk_assure_weight(co_mst_env_t *env, aff_chunk_t *c) {
 /**
  * Count the number of interfering affinity neighbours
  */
-static int count_interfering_aff_neighs(co_mst_env_t *env, affinity_node_t *an) {
-	neighb_t     *neigh;
-	ir_node      *irn  = an->irn;
-	co_mst_irn_t *node = get_co_mst_irn(env, irn);
-	int          res   = 0;
+static int count_interfering_aff_neighs(co_mst_env_t *env, const affinity_node_t *an) {
+	const neighb_t     *neigh;
+	ir_node            *irn  = an->irn;
+	const co_mst_irn_t *node = get_co_mst_irn(env, irn);
+	int                res   = 0;
 
 	co_gs_foreach_neighb(an, neigh) {
-		ir_node *n = neigh->irn;
-		int     i;
+		const ir_node *n = neigh->irn;
+		int           i;
 
 		/* skip ignore nodes */
 		if (arch_irn_is(env->aenv, n, ignore))
 			continue;
 
 		/* check if the affinity neighbour interfere */
-		for (i = 0; i < ARR_LEN(node->int_neighs); ++i) {
+		for (i = 0; i < node->n_neighs; ++i) {
 			if (node->int_neighs[i] == n) {
 				++res;
 				break;
@@ -450,7 +529,6 @@ static void build_affinity_chunks(co_mst_env_t *env) {
 	ir_node     *n;
 	int         i, len;
 	aff_chunk_t *curr_chunk;
-	pset_new_iterator_t iter;
 
 	/* at first we create the affinity edge objects */
 	be_ifg_foreach_node(env->ifg, nodes_it, n) {
@@ -470,6 +548,8 @@ static void build_affinity_chunks(co_mst_env_t *env) {
 
 			if (n1->int_aff_neigh < 0)
 				n1->int_aff_neigh = count_interfering_aff_neighs(env, an);
+
+			/* build the affinity edges */
 			co_gs_foreach_neighb(an, neigh) {
 				ir_node *m    = neigh->irn;
 				int     m_idx = get_irn_idx(m);
@@ -491,6 +571,10 @@ static void build_affinity_chunks(co_mst_env_t *env) {
 						affinity_node_t *am = get_affinity_info(env->co, m);
 						n2->int_aff_neigh = count_interfering_aff_neighs(env, am);
 					}
+					/*
+					 * these weights are pure hackery ;-).
+					 * It's not chriswue's fault but mine.
+					 */
 					edge.weight = (double)neigh->costs / (double)(1 + n1->int_aff_neigh + n2->int_aff_neigh);
 					ARR_APP1(aff_edge_t, edges, edge);
 				}
@@ -502,25 +586,38 @@ static void build_affinity_chunks(co_mst_env_t *env) {
 	len = ARR_LEN(edges);
 	qsort(edges, len, sizeof(edges[0]), cmp_aff_edge);
 	for (i = 0; i < len; ++i) {
-		aff_chunk_t *c1 = get_aff_chunk(env, edges[i].src);
-		aff_chunk_t *c2 = get_aff_chunk(env, edges[i].tgt);
-
-		DBG((env->dbg, LEVEL_1, "edge (%u,%u) %f\n", edges[i].src->node_idx, edges[i].tgt->node_idx, edges[i].weight));
+		DBG((dbg, LEVEL_1, "edge (%u,%u) %f\n", edges[i].src->node_idx, edges[i].tgt->node_idx, edges[i].weight));
 
-		(void)aff_chunk_absorb(env, c1, c2);
+		(void)aff_chunk_absorb(env, edges[i].src, edges[i].tgt);
 	}
 
 	/* now insert all chunks into a priority queue */
-	foreach_pset_new(&env->chunkset, curr_chunk, iter) {
+	foreach_pset(env->chunkset, curr_chunk) {
 		aff_chunk_assure_weight(env, curr_chunk);
 
-		DBG((env->dbg, LEVEL_1, "entry #%d", curr_chunk->id));
+		DBG((dbg, LEVEL_1, "entry #%d", curr_chunk->id));
 		DBG_AFF_CHUNK(env, LEVEL_1, curr_chunk);
-		DBG((env->dbg, LEVEL_1, "\n"));
-
+		DBG((dbg, LEVEL_1, "\n"));
 
 		pqueue_put(env->chunks, curr_chunk, curr_chunk->weight);
 	}
+	foreach_phase_irn(&env->ph, n) {
+		co_mst_irn_t *mirn = get_co_mst_irn(env, n);
+
+		if (mirn->chunk == NULL) {
+			/* no chunk is allocated so far, do it now */
+			aff_chunk_t *curr_chunk = new_aff_chunk(env);
+			aff_chunk_add_node(curr_chunk, mirn);
+
+			aff_chunk_assure_weight(env, curr_chunk);
+
+			DBG((dbg, LEVEL_1, "entry #%d", curr_chunk->id));
+			DBG_AFF_CHUNK(env, LEVEL_1, curr_chunk);
+			DBG((dbg, LEVEL_1, "\n"));
+
+			pqueue_put(env->chunks, curr_chunk, curr_chunk->weight);
+		}
+	}
 
 	DEL_ARR_F(edges);
 }
@@ -533,13 +630,13 @@ static void expand_chunk_from(co_mst_env_t *env, co_mst_irn_t *node, bitset_t *v
 {
 	waitq *nodes = new_waitq();
 
-	DBG((env->dbg, LEVEL_1, "\nExpanding new chunk (id %d) from %+F:", chunk->id, node->irn));
+	DBG((dbg, LEVEL_1, "\n\tExpanding new chunk (#%d) from %+F, color %d:", chunk->id, node->irn, col));
 
 	/* init queue and chunk */
 	waitq_put(nodes, node);
 	bitset_set(visited, get_irn_idx(node->irn));
 	aff_chunk_add_node(chunk, node);
-	DB((env->dbg, LEVEL_1, " %+F", node->irn));
+	DB((dbg, LEVEL_1, " %+F", node->irn));
 
 	/* as long as there are nodes in the queue */
 	while (! waitq_empty(nodes)) {
@@ -576,7 +673,7 @@ static void expand_chunk_from(co_mst_env_t *env, co_mst_irn_t *node, bitset_t *v
 					*/
 					bitset_set(visited, m_idx);
 					aff_chunk_add_node(chunk, n2);
-					DB((env->dbg, LEVEL_1, " %+F", n2->irn));
+					DB((dbg, LEVEL_1, " %+F", n2->irn));
 					/* enqueue for further search */
 					waitq_put(nodes, n2);
 				}
@@ -584,7 +681,7 @@ static void expand_chunk_from(co_mst_env_t *env, co_mst_irn_t *node, bitset_t *v
 		}
 	}
 
-	DB((env->dbg, LEVEL_1, "\n"));
+	DB((dbg, LEVEL_1, "\n"));
 
 	del_waitq(nodes);
 }
@@ -594,29 +691,31 @@ static void expand_chunk_from(co_mst_env_t *env, co_mst_irn_t *node, bitset_t *v
  */
 static aff_chunk_t *fragment_chunk(co_mst_env_t *env, int col, aff_chunk_t *c, waitq *tmp) {
 	bitset_t    *visited = bitset_irg_malloc(env->co->irg);
-	int         idx;
+	int         idx, len;
 	aff_chunk_t *best = NULL;
 
-	bitset_foreach(c->nodes, idx) {
+	for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
 		ir_node       *irn;
 		co_mst_irn_t  *node;
 		aff_chunk_t   *tmp_chunk;
 		decide_func_t *decider;
 		int           check_for_best;
 
-		if (bitset_is_set(visited, idx))
+		irn = c->n[idx];
+		if (bitset_is_set(visited, get_irn_idx(irn)))
 			continue;
 
-		irn  = get_idx_irn(env->co->irg, idx);
 		node = get_co_mst_irn(env, irn);
 
 		if (get_mst_irn_col(node) == col) {
 			decider        = decider_has_color;
 			check_for_best = 1;
+			DBG((dbg, LEVEL_4, "\tcolor %d wanted", col));
 		}
 		else {
 			decider        = decider_hasnot_color;
 			check_for_best = 0;
+			DBG((dbg, LEVEL_4, "\tcolor %d forbidden", col));
 		}
 
 		/* create a new chunk starting at current node */
@@ -668,20 +767,52 @@ static INLINE void col_cost_init_single(co_mst_env_t *env, col_cost_t *cost, int
  * Resets the temporary fixed color of all nodes within wait queue @p nodes.
  * ATTENTION: the queue is empty after calling this function!
  */
-static INLINE void reject_coloring(waitq *nodes) {
-	while (! waitq_empty(nodes)) {
-		co_mst_irn_t *n = waitq_get(nodes);
-		n->tmp_fixed = 0;
+static INLINE void reject_coloring(struct list_head *nodes) {
+	co_mst_irn_t *n, *temp;
+	DB((dbg, LEVEL_4, "\treject coloring for"));
+	list_for_each_entry_safe(co_mst_irn_t, n, temp, nodes, list) {
+		DB((dbg, LEVEL_4, " %+F", n->irn));
+		assert(n->tmp_col >= 0);
+		n->tmp_col = -1;
+		list_del_init(&n->list);
+	}
+	DB((dbg, LEVEL_4, "\n"));
+}
+
+static INLINE void materialize_coloring(struct list_head *nodes) {
+	co_mst_irn_t *n, *temp;
+	list_for_each_entry_safe(co_mst_irn_t, n, temp, nodes, list) {
+		assert(n->tmp_col >= 0);
+		n->col     = n->tmp_col;
+		n->tmp_col = -1;
+		list_del_init(&n->list);
 	}
 }
 
+static INLINE void set_temp_color(co_mst_irn_t *node, int col, struct list_head *changed)
+{
+	assert(col >= 0);
+	assert(!node->fixed);
+	assert(node->tmp_col < 0);
+	assert(node->list.next == &node->list && node->list.prev == &node->list);
+
+	list_add_tail(&node->list, changed);
+	node->tmp_col = col;
+}
+
+static INLINE int is_loose(co_mst_irn_t *node)
+{
+	return !node->fixed && node->tmp_col < 0;
+}
+
 /**
  * Determines the costs for each color if it would be assigned to node @p node.
  */
 static void determine_color_costs(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs) {
 	affinity_node_t *an = get_affinity_info(env->co, node->irn);
 	neighb_t        *aff_neigh;
-	int             idx, i;
+	bitset_pos_t     idx;
+	int              i;
 
 	col_cost_init(env, costs, 0.0);
 
@@ -700,7 +831,7 @@ static void determine_color_costs(co_mst_env_t *env, co_mst_irn_t *node, col_cos
 			c     = (double)aff_neigh->costs;
 
 			/* calculate costs for fixed affinity neighbours */
-			if (neigh->tmp_fixed || neigh->fixed) {
+			if (!is_loose(neigh)) {
 				int col = get_mst_irn_col(neigh);
 				costs[col].cost -= c * AFF_NEIGHBOUR_FIX_BENEFIT;
 			}
@@ -708,7 +839,7 @@ static void determine_color_costs(co_mst_env_t *env, co_mst_irn_t *node, col_cos
 	}
 
 	/* calculate (positive) costs for interfering neighbours */
-	for (i = 0; i < ARR_LEN(node->int_neighs); ++i) {
+	for (i = 0; i < node->n_neighs; ++i) {
 		co_mst_irn_t *neigh;
 		int          col, col_cnt;
 		ir_node      *int_neigh;
@@ -723,7 +854,7 @@ static void determine_color_costs(co_mst_env_t *env, co_mst_irn_t *node, col_cos
 		col     = get_mst_irn_col(neigh);
 		col_cnt = bitset_popcnt(neigh->adm_colors);
 
-		if (neigh->tmp_fixed || neigh->fixed) {
+		if (!is_loose(neigh)) {
 			/* colors of fixed interfering neighbours are infeasible */
 			costs[col].cost = COL_COST_INFEASIBLE;
 		}
@@ -738,6 +869,8 @@ static void determine_color_costs(co_mst_env_t *env, co_mst_irn_t *node, col_cos
 				}
 			}
 		}
+
+		DB((dbg, LEVEL_4, "\tneigh %+F, loose: %d, color: %d\n", int_neigh, is_loose(neigh), col));
 	}
 
 	/* set all not admissible colors to COL_COST_INFEASIBLE */
@@ -746,26 +879,25 @@ static void determine_color_costs(co_mst_env_t *env, co_mst_irn_t *node, col_cos
 }
 
 /* need forward declaration due to recursive call */
-static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs, waitq *changed_ones);
+static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs, struct list_head *changed_ones);
 
 /**
  * Tries to change node to a color but @p explude_col.
  * @return 1 if succeeded, 0 otherwise.
  */
-static int change_node_color_excluded(co_mst_env_t *env, co_mst_irn_t *node, int exclude_col, waitq *changed_ones) {
+static int change_node_color_excluded(co_mst_env_t *env, co_mst_irn_t *node, int exclude_col, struct list_head *changed_ones) {
 	int col = get_mst_irn_col(node);
 	int res = 0;
 
 	/* neighbours has already a different color -> good, temporary fix it */
 	if (col != exclude_col) {
-		node->tmp_fixed = 1;
-		node->tmp_col   = col;
-		waitq_put(changed_ones, node);
+		if (is_loose(node))
+			set_temp_color(node, col, changed_ones);
 		return 1;
 	}
 
 	/* The node has the color it should not have _and_ has not been visited yet. */
-	if (! (node->tmp_fixed || node->fixed)) {
+	if (is_loose(node)) {
 		col_cost_t *costs = alloca(env->n_regs * sizeof(costs[0]));
 
 		/* Get the costs for giving the node a specific color. */
@@ -789,14 +921,13 @@ static int change_node_color_excluded(co_mst_env_t *env, co_mst_irn_t *node, int
  * ATTENTION: Expect @p costs already sorted by increasing costs.
  * @return 1 if coloring could be applied, 0 otherwise.
  */
-static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs, waitq *changed_ones) {
+static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs, struct list_head *changed_ones) {
 	int   i;
-	waitq *local_changed = new_waitq();
-	waitq *tmp           = new_waitq();
+	struct list_head local_changed;
 
-	DBG((env->dbg, LEVEL_1, "\tRecoloring %+F with color-costs", node->irn));
+	DBG((dbg, LEVEL_1, "\tRecoloring %+F with color-costs", node->irn));
 	DBG_COL_COST(env, LEVEL_1, costs);
-	DB((env->dbg, LEVEL_1, "\n"));
+	DB((dbg, LEVEL_1, "\n"));
 
 	for (i = 0; i < env->n_regs; ++i) {
 		int tgt_col  = costs[i].col;
@@ -805,22 +936,17 @@ static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *cost
 
 		/* If the costs for that color (and all successive) are infinite, bail out we won't make it anyway. */
 		if (costs[i].cost == COL_COST_INFEASIBLE) {
-			node->tmp_fixed = 0;
-			del_waitq(local_changed);
-			del_waitq(tmp);
 			return 0;
 		}
 
 		/* Set the new color of the node and mark the node as temporarily fixed. */
-		assert(! node->tmp_fixed && "Node must not have been temporary fixed.");
-		node->tmp_fixed = 1;
-		node->tmp_col   = tgt_col;
-
-		assert(waitq_empty(local_changed) && "Node queue should be empty here.");
-		waitq_put(local_changed, node);
+		assert(node->tmp_col < 0 && "Node must not have been temporary fixed.");
+		INIT_LIST_HEAD(&local_changed);
+		set_temp_color(node, tgt_col, &local_changed);
+		DBG((dbg, LEVEL_4, "\tTemporary setting %+F to color %d\n", node->irn, tgt_col));
 
 		/* try to color all interfering neighbours with current color forbidden */
-		for (j = 0; j < ARR_LEN(node->int_neighs); ++j) {
+		for (j = 0; j < node->n_neighs; ++j) {
 			co_mst_irn_t *nn;
 			ir_node      *neigh;
 
@@ -831,6 +957,8 @@ static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *cost
 				continue;
 
 			nn = get_co_mst_irn(env, neigh);
+			DB((dbg, LEVEL_4, "\tHandling neighbour %+F, at position %d (fixed: %d, tmp_col: %d, col: %d)\n",
+				neigh, j, nn->fixed, nn->tmp_col, nn->col));
 
 			/*
 				Try to change the color of the neighbor and record all nodes which
@@ -840,13 +968,9 @@ static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *cost
 			*/
 			if (get_mst_irn_col(nn) == tgt_col) {
 				/* try to color neighbour with tgt_col forbidden */
-				neigh_ok = change_node_color_excluded(env, nn, tgt_col, tmp);
-
-				/* join lists of changed nodes */
-				while (! waitq_empty(tmp))
-					waitq_put(local_changed, waitq_get(tmp));
+				neigh_ok = change_node_color_excluded(env, nn, tgt_col, &local_changed);
 
-				if (! neigh_ok)
+				if (!neigh_ok)
 					break;
 			}
 		}
@@ -857,20 +981,15 @@ static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *cost
 		*/
 		if (neigh_ok) {
 			/* append the local_changed ones to global ones */
-			while (! waitq_empty(local_changed))
-				waitq_put(changed_ones, waitq_get(local_changed));
-			del_waitq(local_changed);
-			del_waitq(tmp);
+			list_splice(&local_changed, changed_ones);
 			return 1;
 		}
 		else {
 			/* coloring of neighbours failed, so we try next color */
-			reject_coloring(local_changed);
+			reject_coloring(&local_changed);
 		}
 	}
 
-	del_waitq(local_changed);
-	del_waitq(tmp);
 	return 0;
 }
 
@@ -878,17 +997,14 @@ static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *cost
  * Tries to bring node @p node and all it's neighbours to color @p tgt_col.
  * @return 1 if color @p col could be applied, 0 otherwise
  */
-static int change_node_color(co_mst_env_t *env, co_mst_irn_t *node, int tgt_col, waitq *changed_ones) {
+static int change_node_color(co_mst_env_t *env, co_mst_irn_t *node, int tgt_col, struct list_head *changed_ones) {
 	int col = get_mst_irn_col(node);
 
 	/* if node already has the target color -> good, temporary fix it */
 	if (col == tgt_col) {
-		DBG((env->dbg, LEVEL_4, "\t\tCNC: %+F has already color %d, fix temporary\n", node->irn, tgt_col));
-		if (! node->tmp_fixed) {
-			node->tmp_fixed = 1;
-			node->tmp_col   = tgt_col;
-			waitq_put(changed_ones, node);
-		}
+		DBG((dbg, LEVEL_4, "\t\tCNC: %+F has already color %d, fix temporary\n", node->irn, tgt_col));
+		if (is_loose(node))
+			set_temp_color(node, tgt_col, changed_ones);
 		return 1;
 	}
 
@@ -896,30 +1012,30 @@ static int change_node_color(co_mst_env_t *env, co_mst_irn_t *node, int tgt_col,
 		Node has not yet a fixed color and target color is admissible
 		-> try to recolor node and it's affinity neighbours
 	*/
-	if (! (node->fixed || node->tmp_fixed) && bitset_is_set(node->adm_colors, tgt_col)) {
+	if (is_loose(node) && bitset_is_set(node->adm_colors, tgt_col)) {
 		col_cost_t *costs = alloca(env->n_regs * sizeof(costs[0]));
 		int        res;
 
 		col_cost_init_single(env, costs, tgt_col);
 
-		DBG((env->dbg, LEVEL_4, "\t\tCNC: Attempt to recolor %+F ===>>\n", node->irn));
+		DBG((dbg, LEVEL_4, "\t\tCNC: Attempt to recolor %+F ===>>\n", node->irn));
 		res = recolor_nodes(env, node, costs, changed_ones);
-		DBG((env->dbg, LEVEL_4, "\t\tCNC: <<=== Recoloring of %+F %s\n", node->irn, res ? "succeeded" : "failed"));
+		DBG((dbg, LEVEL_4, "\t\tCNC: <<=== Recoloring of %+F %s\n", node->irn, res ? "succeeded" : "failed"));
 
 		return res;
 	}
 
-	DEBUG_ONLY(
-		if (firm_dbg_get_mask(env->dbg) & LEVEL_4) {
-			if (node->fixed || node->tmp_fixed)
-				DB((env->dbg, LEVEL_4, "\t\tCNC: %+F has already fixed color %d\n", node->irn, col));
+#ifndef NDEBUG
+		if (firm_dbg_get_mask(dbg) & LEVEL_4) {
+			if (!is_loose(node))
+				DB((dbg, LEVEL_4, "\t\tCNC: %+F has already fixed color %d\n", node->irn, col));
 			else {
-				DB((env->dbg, LEVEL_4, "\t\tCNC: color %d not admissible for %+F (", tgt_col, node->irn));
+				DB((dbg, LEVEL_4, "\t\tCNC: color %d not admissible for %+F (", tgt_col, node->irn));
 				dbg_admissible_colors(env, node);
-				DB((env->dbg, LEVEL_4, ")\n"));
+				DB((dbg, LEVEL_4, ")\n"));
 			}
 		}
-	)
+#endif
 
 	return 0;
 }
@@ -931,38 +1047,71 @@ static int change_node_color(co_mst_env_t *env, co_mst_irn_t *node, int tgt_col,
 static void color_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
 	aff_chunk_t *best_chunk   = NULL;
 	int         best_color    = -1;
-	waitq       *changed_ones = new_waitq();
+	int         did_all       = 0;
 	waitq       *tmp_chunks   = new_waitq();
+	waitq       *best_starts  = NULL;
 	bitset_t    *visited;
-	int         col, idx;
+	int         col, idx, len;
+	struct list_head changed_ones;
 
-	DB((env->dbg, LEVEL_2, "fragmentizing chunk #%d", c->id));
+	DB((dbg, LEVEL_2, "fragmentizing chunk #%d", c->id));
 	DBG_AFF_CHUNK(env, LEVEL_2, c);
-	DB((env->dbg, LEVEL_2, "\n"));
+	DB((dbg, LEVEL_2, "\n"));
+
+
+	/* check which color is the "best" for the given chunk.
+	 * if we found a color which was ok for all nodes, we take it
+	 * and do not look further. (see did_all flag usage below.)
+	 * If we have many colors which fit all nodes it is hard to decide
+	 * which one to take anyway.
+	 * TODO Sebastian: Perhaps we should at all nodes and figure out
+	 * a suitable color using costs as done above (determine_color_costs).
+	 */
+	for (col = 0; col < env->n_regs && !did_all; ++col) {
+		int         one_good     = 0;
+		waitq       *good_starts = new_waitq();
+		aff_chunk_t *local_best;
 
+		/* skip ignore colors */
+		if (bitset_is_set(env->ignore_regs, col))
+			continue;
 
-	/* check which color is the "best" for the given chunk */
-	for (col = 0; col < env->k; ++col) {
-		int         one_good = 0;
-		aff_chunk_t *local_best;
+		DB((dbg, LEVEL_3, "\ttrying color %d\n", col));
 
-		DB((env->dbg, LEVEL_3, "\ttrying color %d\n", col));
+		/* suppose we can color all nodes to the same color */
+		did_all = 1;
+
+		INIT_LIST_HEAD(&changed_ones);
 
 		/* try to bring all nodes of given chunk to the current color. */
-		bitset_foreach(c->nodes, idx) {
-			ir_node      *irn  = get_idx_irn(env->co->irg, idx);
+		for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
+			ir_node      *irn  = c->n[idx];
 			co_mst_irn_t *node = get_co_mst_irn(env, irn);
+			int          good  = 0;
 
 			assert(! node->fixed && "Node must not have a fixed color.");
+			DB((dbg, LEVEL_4, "\t\tBringing %+F from color %d to color %d ...\n", irn, node->col, col));
+
+			/*
+				The order of the colored nodes is important, so we record the successfully
+				colored ones in the order they appeared.
+			*/
+			good = change_node_color(env, node, col, &changed_ones);
+			if (good) {
+				waitq_put(good_starts, node);
+			}
+
+			one_good |= good;
+			did_all  &= good;
 
-			DB((env->dbg, LEVEL_4, "\t\tBringing %+F from color %d to color %d ...\n", irn, node->col, col));
-			one_good |= change_node_color(env, node, col, changed_ones);
-			DB((env->dbg, LEVEL_4, "\t\t... %+F attempt from %d to %d %s\n", irn, node->col, col, one_good ? "succeeded" : "failed"));
+			DB((dbg, LEVEL_4, "\t\t... %+F attempt from %d to %d %s\n", irn, node->col, col, one_good ? "succeeded" : "failed"));
 		}
 
 		/* try next color when failed */
-		if (! one_good)
+		if (! one_good) {
+			reject_coloring(&changed_ones);
 			continue;
+		}
 
 		/* fragment the chunk according to the coloring */
 		local_best = fragment_chunk(env, col, c, tmp_chunks);
@@ -972,20 +1121,26 @@ static void color_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
 		if (local_best) {
 			aff_chunk_assure_weight(env, local_best);
 
-			DB((env->dbg, LEVEL_4, "\t\tlocal best chunk (id %d) for color %d: ", local_best->id, col));
+			DB((dbg, LEVEL_4, "\t\tlocal best chunk (id %d) for color %d: ", local_best->id, col));
 			DBG_AFF_CHUNK(env, LEVEL_4, local_best);
 
 			if (! best_chunk || best_chunk->weight < local_best->weight) {
 				best_chunk = local_best;
 				best_color = col;
-				DB((env->dbg, LEVEL_4, "\n\t\t... setting global best chunk (id %d), color %d\n", best_chunk->id, best_color));
+				if (best_starts)
+					del_waitq(best_starts);
+				best_starts = good_starts;
+				DB((dbg, LEVEL_4, "\n\t\t... setting global best chunk (id %d), color %d\n", best_chunk->id, best_color));
 			} else {
-				DB((env->dbg, LEVEL_4, "\n\t\t... omitting, global best is better\n"));
+				DB((dbg, LEVEL_4, "\n\t\t... omitting, global best is better\n"));
+				del_waitq(good_starts);
 			}
 		}
+		else {
+			del_waitq(good_starts);
+		}
 
-		/* reject the coloring and bring the coloring to the initial state */
-		reject_coloring(changed_ones);
+		reject_coloring(&changed_ones);
 	}
 
 	/* free all intermediate created chunks except best one */
@@ -998,40 +1153,48 @@ static void color_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
 
 	/* return if coloring failed */
 	if (! best_chunk) {
-		delete_aff_chunk(env, c);
-		del_waitq(changed_ones);
+		if (best_starts)
+			del_waitq(best_starts);
 		return;
 	}
 
-	DB((env->dbg, LEVEL_2, "\tbest chunk #%d ", best_chunk->id));
+	DB((dbg, LEVEL_2, "\tbest chunk #%d ", best_chunk->id));
 	DBG_AFF_CHUNK(env, LEVEL_2, best_chunk);
-	DB((env->dbg, LEVEL_2, "using color %d\n", best_color));
+	DB((dbg, LEVEL_2, "using color %d\n", best_color));
 
-	/* get the best fragment from the best list and color it */
-	bitset_foreach(best_chunk->nodes, idx) {
-		ir_node      *irn  = get_idx_irn(env->co->irg, idx);
+	INIT_LIST_HEAD(&changed_ones);
+	for (idx = 0, len = ARR_LEN(best_chunk->n); idx < len; ++idx) {
+		ir_node      *irn  = best_chunk->n[idx];
 		co_mst_irn_t *node = get_co_mst_irn(env, irn);
-		int          res;
-
-		res = change_node_color(env, node, best_color, changed_ones);
-		assert(res && "color manifesting failed");
-		node->fixed = 1;
-		node->chunk = best_chunk;
-	}
-
-	/* materialize colors on changed nodes */
-	while (! waitq_empty(changed_ones)) {
-		co_mst_irn_t *n = waitq_get(changed_ones);
-		n->tmp_fixed = 0;
-		n->col       = n->tmp_col;
+		int res;
+
+		/* bring the node to the color. */
+		DB((dbg, LEVEL_4, "\tManifesting color %d for %+F, chunk #%d\n", best_color, node->irn, best_chunk->id));
+		INIT_LIST_HEAD(&changed_ones);
+		res = change_node_color(env, node, best_color, &changed_ones);
+		if (res) {
+			materialize_coloring(&changed_ones);
+			node->fixed = 1;
+		}
 	}
 
 	/* remove the nodes in best chunk from original chunk */
 	bitset_andnot(c->nodes, best_chunk->nodes);
+	for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
+		ir_node *irn = c->n[idx];
+
+		if (bitset_is_set(best_chunk->nodes, get_irn_idx(irn))) {
+			int last = ARR_LEN(c->n) - 1;
+
+			c->n[idx] = c->n[last];
+			ARR_SHRINKLEN(c->n, last);
+			len--;
+		}
+	}
 
 	/* we have to get the nodes back into the original chunk because they are scattered over temporary chunks */
-	bitset_foreach(c->nodes, idx) {
-		ir_node      *n  = get_idx_irn(env->co->irg, idx);
+	for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
+		ir_node      *n  = c->n[idx];
 		co_mst_irn_t *nn = get_co_mst_irn(env, n);
 		nn->chunk = c;
 	}
@@ -1039,10 +1202,10 @@ static void color_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
 	/* fragment the remaining chunk */
 	visited = bitset_irg_malloc(env->co->irg);
 	bitset_or(visited, best_chunk->nodes);
-	bitset_foreach(c->nodes, idx) {
-		if (! bitset_is_set(visited, idx)) {
+	for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
+		ir_node *irn = c->n[idx];
+		if (! bitset_is_set(visited, get_irn_idx(irn))) {
 			aff_chunk_t  *new_chunk = new_aff_chunk(env);
-			ir_node      *irn       = get_idx_irn(env->co->irg, idx);
 			co_mst_irn_t *node      = get_co_mst_irn(env, irn);
 
 			expand_chunk_from(env, node, visited, new_chunk, c, decider_always_yes, 0);
@@ -1054,14 +1217,14 @@ static void color_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
 	/* clear obsolete chunks and free some memory */
 	delete_aff_chunk(env, best_chunk);
 	bitset_free(visited);
-	del_waitq(changed_ones);
+	if (best_starts)
+		del_waitq(best_starts);
 }
 
 /**
  * Main driver for mst safe coalescing algorithm.
  */
-int co_solve_heuristic_mst(copy_opt_t *co)
-{
+int co_solve_heuristic_mst(copy_opt_t *co) {
 	unsigned     n_regs       = co->cls->n_regs;
 	bitset_t     *ignore_regs = bitset_alloca(n_regs);
 	unsigned     k;
@@ -1074,7 +1237,6 @@ int co_solve_heuristic_mst(copy_opt_t *co)
 	k = be_put_ignore_regs(co->cenv->birg, co->cls, ignore_regs);
 	k = n_regs - k;
 
-	FIRM_DBG_REGISTER(mst_env.dbg, "firm.be.co.heur4");
 	mst_env.n_regs      = n_regs;
 	mst_env.k           = k;
 	mst_env.chunks      = new_pqueue();
@@ -1082,9 +1244,9 @@ int co_solve_heuristic_mst(copy_opt_t *co)
 	mst_env.ignore_regs = ignore_regs;
 	mst_env.ifg         = co->cenv->ifg;
 	mst_env.aenv        = co->aenv;
-	pset_new_init(&mst_env.chunkset);
+	mst_env.chunkset    = pset_new_ptr(512);
 
-	DBG((mst_env.dbg, LEVEL_1, "==== Coloring %+F, class %s ====\n", co->irg, co->cls->name));
+	DBG((dbg, LEVEL_1, "==== Coloring %+F, class %s ====\n", co->irg, co->cls->name));
 
 	/* build affinity chunks */
 	build_affinity_chunks(&mst_env);
@@ -1094,7 +1256,7 @@ int co_solve_heuristic_mst(copy_opt_t *co)
 		aff_chunk_t *chunk = pqueue_get(mst_env.chunks);
 
 		color_aff_chunk(&mst_env, chunk);
-		DB((mst_env.dbg, LEVEL_4, "<<<====== Coloring chunk (%d) done\n", chunk->id));
+		DB((dbg, LEVEL_4, "<<<====== Coloring chunk (%d) done\n", chunk->id));
 		delete_aff_chunk(&mst_env, chunk);
 	}
 
@@ -1106,7 +1268,7 @@ int co_solve_heuristic_mst(copy_opt_t *co)
 		if (arch_irn_is(mst_env.aenv, irn, ignore))
 			continue;
 
-		assert(mirn->fixed && "Node should have fixed color");
+		// assert(mirn->fixed && "Node should have fixed color");
 
 		/* skip nodes where color hasn't changed */
 		if (mirn->init_col == mirn->col)
@@ -1114,13 +1276,19 @@ int co_solve_heuristic_mst(copy_opt_t *co)
 
 		reg = arch_register_for_index(co->cls, mirn->col);
 		arch_set_irn_register(co->aenv, irn, reg);
-		DB((mst_env.dbg, LEVEL_1, "%+F set color from %d to %d\n", irn, mirn->init_col, mirn->col));
+		DB((dbg, LEVEL_1, "%+F set color from %d to %d\n", irn, mirn->init_col, mirn->col));
 	}
 
 	/* free allocated memory */
 	del_pqueue(mst_env.chunks);
 	phase_free(&mst_env.ph);
-	pset_new_destroy(&mst_env.chunkset);
+	del_pset(mst_env.chunkset);
 
 	return 0;
 }
+
+void be_init_copyheur4(void) {
+	FIRM_DBG_REGISTER(dbg, "firm.be.co.heur4");
+}
+
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_copyheur4);