X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbespillslots.c;h=3d9993afb2b23f164855fc0149cdf97501569ab8;hb=02046d6f22e734521c84dfb2f342cf61e6442c2f;hp=af60c6c0f4072f9a78062c14d10145af08fb03a1;hpb=693d8f30cce7910cee31756db96a32e7a1c65ad9;p=libfirm

diff --git a/ir/be/bespillslots.c b/ir/be/bespillslots.c
index af60c6c0f..3d9993afb 100644
--- a/ir/be/bespillslots.c
+++ b/ir/be/bespillslots.c
@@ -25,7 +25,9 @@
 #include "bespillslots.h"
 #include "bechordal_t.h"
 #include "bejavacoal.h"
-
+#include "benodesets.h"
+#include "bestatevent.h"
+#include "bespilloptions.h"
 
 #define DBG_COALESCING		1
 #define DBG_INTERFERENCES	2
@@ -36,8 +38,10 @@ static firm_dbg_module_t *dbg = NULL;
 
 typedef struct _spill_t {
 	ir_node *spill;
-	/** regclass of the spilled value */
-	const arch_register_class_t *cls;
+	/** mode of the spilled value */
+	const ir_mode *mode;
+	/** alignment for the spilled value */
+	int alignment;
 	/** index into spillslot_unionfind unionfind structure */
 	int spillslot;
 } spill_t;
@@ -47,32 +51,37 @@ typedef struct _affinity_edge_t {
 	int slot1, slot2;
 } affinity_edge_t;
 
-typedef struct _ss_env_t {
+struct _be_fec_env_t {
 	struct obstack obst;
-	const be_chordal_env_t *chordal_env;
+	const arch_env_t *arch_env;
+	be_irg_t *birg;
 	set *spills;
 	ir_node **reloads;
 	affinity_edge_t **affinity_edges;
 	set *memperms;
-} ss_env_t;
+};
 
 /** Compare 2 affinity edges (used in quicksort) */
-static int cmp_affinity(const void *d1, const void *d2) {
-	const affinity_edge_t *e1 = d1;
-	const affinity_edge_t *e2 = d2;
+static int cmp_affinity(const void *d1, const void *d2)
+{
+	const affinity_edge_t * const *e1 = d1;
+	const affinity_edge_t * const *e2 = d2;
 
-	return e1->affinity < e2->affinity ? -1 : 1;
+	// sort in descending order
+	return (*e1)->affinity < (*e2)->affinity ? 1 : -1;
 }
 
-static int cmp_spill(const void* d1, const void* d2, size_t size) {
+static int cmp_spill(const void* d1, const void* d2, size_t size)
+{
 	const spill_t* s1 = d1;
 	const spill_t* s2 = d2;
 	return s1->spill != s2->spill;
 }
 
-static spill_t *get_spill(ss_env_t *env, ir_node *node) {
+static spill_t *get_spill(be_fec_env_t *env, ir_node *node)
+{
 	spill_t spill, *res;
-	int hash = HASH_PTR(node);
+	int hash = nodeset_hash(node);
 
 	spill.spill = node;
 	res = set_find(env->spills, &spill, sizeof(spill), hash);
@@ -89,60 +98,82 @@ static spill_t *get_spill(ss_env_t *env, ir_node *node) {
  *                                      |_|
  */
 
-static spill_t *collect_spill(ss_env_t *env, ir_node *node, const arch_register_class_t *cls) {
-	spill_t spill, *res;
-	int hash = HASH_PTR(node);
+static ir_node *get_memory_edge(const ir_node *node)
+{
+	int i, arity;
+
+	arity = get_irn_arity(node);
+	for(i = arity - 1; i >= 0; --i) {
+		ir_node *arg = get_irn_n(node, i);
+		if(get_irn_mode(arg) == mode_M)
+			return arg;
+	}
 
-	assert(be_is_Spill(node));
+	return NULL;
+}
 
+static spill_t *collect_spill(be_fec_env_t *env, ir_node *node,
+		                      const ir_mode *mode, int align)
+{
+	spill_t spill, *res;
+	int hash = nodeset_hash(node);
+
+	/* insert into set of spills if not already there */
 	spill.spill = node;
 	res = set_find(env->spills, &spill, sizeof(spill), hash);
 
 	if(res == NULL) {
 		spill.spillslot = set_count(env->spills);
-		spill.cls = cls;
+		spill.mode = mode;
+		spill.alignment = align;
 		res = set_insert(env->spills, &spill, sizeof(spill), hash);
 	} else {
-		assert(cls == res->cls);
+		assert(res->mode == mode);
+		assert(res->alignment == align);
 	}
 
 	return res;
 }
 
-static spill_t *collect_memphi(ss_env_t *env, ir_node *node, const arch_register_class_t *cls) {
+static spill_t *collect_memphi(be_fec_env_t *env, ir_node *node,
+                               const ir_mode *mode, int align)
+{
 	int i, arity;
 	spill_t spill, *res;
-	int hash = HASH_PTR(node);
+	int hash = nodeset_hash(node);
+	const ir_exec_freq *exec_freq = be_get_birg_exec_freq(env->birg);
 
 	assert(is_Phi(node));
 
 	spill.spill = node;
 	res = set_find(env->spills, &spill, sizeof(spill), hash);
 	if(res != NULL) {
+		assert(res->mode == mode);
+		assert(res->alignment == align);
 		return res;
 	}
 
 	spill.spillslot = set_count(env->spills);
-	spill.cls = cls;
+	spill.mode = mode;
+	spill.alignment = align;
 	res = set_insert(env->spills, &spill, sizeof(spill), hash);
 
-	// is 1 of the arguments a spill?
-	for(i = 0, arity = get_irn_arity(node); i < arity; ++i) {
+	// collect attached spills and mem-phis
+	arity = get_irn_arity(node);
+	for(i = 0; i < arity; ++i) {
 		affinity_edge_t *affinty_edge;
-		ir_node* arg = get_irn_n(node, i);
-		spill_t* arg_spill;
+		ir_node *arg = get_irn_n(node, i);
+		spill_t *arg_spill;
 
-		if(be_is_Spill(arg)) {
-			arg_spill = collect_spill(env, arg, cls);
+		if(is_Phi(arg)) {
+			arg_spill = collect_memphi(env, arg, mode, align);
 		} else {
-			// if it wasn't a spill then it must be a Mem-Phi
-			assert(is_Phi(arg));
-			arg_spill = collect_memphi(env, arg, cls);
+			arg_spill = collect_spill(env, arg, mode, align);
 		}
 
 		// add an affinity edge
 		affinty_edge = obstack_alloc(&env->obst, sizeof(affinty_edge[0]));
-		affinty_edge->affinity = get_block_execfreq(env->chordal_env->exec_freq, get_nodes_block(arg));
+		affinty_edge->affinity = get_block_execfreq(exec_freq, get_nodes_block(arg));
 		affinty_edge->slot1 = res->spillslot;
 		affinty_edge->slot2 = arg_spill->spillslot;
 		ARR_APP1(affinity_edge_t*, env->affinity_edges, affinty_edge);
@@ -151,25 +182,21 @@ static spill_t *collect_memphi(ss_env_t *env, ir_node *node, const arch_register
 	return res;
 }
 
-/**
- * This walker function searches for reloads and collects all the spills
- * and memphis attached to them.
- */
-static void collect_spills_walker(ir_node *node, void *data) {
-	ss_env_t *env = data;
+void be_node_needs_frame_entity(be_fec_env_t *env, ir_node *node,
+                                const ir_mode *mode, int align)
+{
+	ir_node *spillnode = get_memory_edge(node);
+	spill_t *spill;
 
-	if(be_is_Reload(node)) {
-		ir_node *spill = get_irn_n(node, be_pos_Reload_mem);
-		const arch_env_t *arch_env = env->chordal_env->birg->main_env->arch_env;
-		const arch_register_class_t *cls = arch_get_irn_reg_class(arch_env, node, -1);
+	assert(spillnode != NULL);
 
-		if(is_Phi(spill)) {
-			collect_memphi(env, spill, cls);
-		} else {
-			collect_spill(env, spill, cls);
-		}
-		ARR_APP1(ir_node*, env->reloads, node);
+	if (is_Phi(spillnode)) {
+		spill = collect_memphi(env, spillnode, mode, align);
+	} else {
+		spill = collect_spill(env, spillnode, mode, align);
 	}
+
+	ARR_APP1(ir_node *, env->reloads, node);
 }
 
 /*
@@ -180,7 +207,8 @@ static void collect_spills_walker(ir_node *node, void *data) {
  *  \____\___/ \__,_|_|\___||___/\___\___| |____/|_|\___/ \__|___/
  */
 
-static int merge_interferences(ss_env_t *env, bitset_t** interferences, int* spillslot_unionfind, int s1, int s2)
+static int merge_interferences(be_fec_env_t *env, bitset_t** interferences,
+                               int* spillslot_unionfind, int s1, int s2)
 {
 	int res;
 	int i;
@@ -209,8 +237,7 @@ static int merge_interferences(ss_env_t *env, bitset_t** interferences, int* spi
 }
 
 #if 0
-
-static void dump_interference_graph(ss_env_t *env, bitset_t **interferences, const char* suffix) {
+static void dump_interference_graph(be_fec_env_t *env, bitset_t **interferences, const char* suffix) {
 	char name[256];
 	int i;
 	int spillcount;
@@ -248,42 +275,15 @@ static void dump_interference_graph(ss_env_t *env, bitset_t **interferences, con
 	fprintf(f, "}\n");
 	fclose(f);
 }
-
-static void show_stats(ss_env_t *env) {
-	int spillcount;
-	int slotcount;
-	int *slotused;
-	spill_t *spill;
-
-	spillcount = set_count(env->spills);
-	fprintf(stderr, "%s: Collected %d spills\n", get_irg_dump_name(env->chordal_env->birg->irg), spillcount);
-
-	slotused = alloca(spillcount * sizeof(slotused[0]));
-	memset(slotused, 0, spillcount * sizeof(slotused[0]));
-
-	slotcount = 0;
-	for(spill = set_first(env->spills); spill != NULL; spill = set_next(env->spills)) {
-		int slot = spill->spillslot;
-		if(slotused[slot] == 0) {
-			slotused[slot] = 1;
-			slotcount++;
-		}
-	}
-
-	fprintf(stderr, "%s: Coalesced to %d spillslots\n", get_irg_dump_name(env->chordal_env->birg->irg), slotcount);
-}
-
 #endif
 
-static void assign_spillslots(ss_env_t *env);
-
 /**
  * A greedy coalescing algorithm for spillslots:
  *  1. Sort the list of affinity edges
  *  2. Try to merge slots with affinity edges (most expensive slots first)
  *  3. Try to merge everything else that is possible
  */
-static void do_greedy_coalescing(ss_env_t *env)
+static void do_greedy_coalescing(be_fec_env_t *env)
 {
 	int spillcount;
 	spill_t **spilllist;
@@ -292,6 +292,7 @@ static void do_greedy_coalescing(ss_env_t *env)
 	int affinity_edge_count;
 	bitset_t **interferences;
 	int* spillslot_unionfind;
+	const be_lv_t *lv = be_get_birg_liveness(env->birg);
 
 	spillcount = set_count(env->spills);
 	if(spillcount == 0)
@@ -321,7 +322,7 @@ static void do_greedy_coalescing(ss_env_t *env)
 	// construct interferences
 	for(i = 0; i < spillcount; ++i) {
 		for(i2 = i+1; i2 < spillcount; ++i2) {
-			if(values_interfere(env->chordal_env->lv, spilllist[i]->spill, spilllist[i2]->spill)) {
+			if(values_interfere(lv, spilllist[i]->spill, spilllist[i2]->spill)) {
 				DBG((dbg, DBG_INTERFERENCES, "Slot %d and %d interfere\n", i, i2));
 				bitset_set(interferences[i], i2);
 				bitset_set(interferences[i2], i);
@@ -382,7 +383,7 @@ static void do_greedy_coalescing(ss_env_t *env)
 		}
 	}
 
-	// assign spillslots
+	// assign spillslots to spills
 	for(i = 0; i < spillcount; ++i) {
 		spill_t *spill = spilllist[i];
 
@@ -392,63 +393,6 @@ static void do_greedy_coalescing(ss_env_t *env)
 	//dump_interference_graph(env, interferences, "after");
 }
 
-#if 0
-static void do_java_coalescing(ss_env_t *env)
-{
-	int spillcount;
-	spill_t **spilllist;
-	spill_t *spill;
-	int i, i2;
-	be_java_coal_t *coal;
-
-	spillcount = set_count(env->spills);
-	if(spillcount == 0)
-		return;
-
-	spilllist = alloca(spillcount * sizeof(spilllist[0]));
-
-	DEBUG_ONLY(
-		memset(spilllist, 0, spillcount * sizeof(spilllist[0]));
-	);
-
-	coal = be_java_coal_init("spillslot coalescing", spillcount, spillcount, 1);
-
-	for(spill = set_first(env->spills), i = 0; spill != NULL; spill = set_next(env->spills), ++i) {
-		assert(spill->spillslot < spillcount);
-		DEBUG_ONLY(assert(spilllist[spill->spillslot] == NULL));
-		spilllist[spill->spillslot] = spill;
-
-		be_java_coal_set_color(coal, spill->spillslot, spill->spillslot);
-	}
-
-	// construct interferences
-	for(i = 0; i < spillcount; ++i) {
-		for(i2 = i+1; i2 < spillcount; ++i2) {
-			if(values_interfere(env->chordal_env->lv, spilllist[i]->spill, spilllist[i2]->spill)) {
-				be_java_coal_add_int_edge(coal, i, i2);
-			}
-		}
-	}
-
-	for(i = 0; i < ARR_LEN(env->affinity_edges); ++i) {
-		const affinity_edge_t *edge = env->affinity_edges[i];
-		int n = edge->slot1;
-		int m = edge->slot2;
-		int costs = (int) (edge->affinity * 10000);
-		be_java_coal_add_aff_edge(coal, n, m, costs);
-	}
-
-	be_java_coal_coalesce(coal);
-
-	// construct spillslots
-	for(i = 0; i < spillcount; ++i) {
-		spill_t *spill = spilllist[i];
-		spill->spillslot = be_java_coal_get_color(coal, i);
-	}
-	be_java_coal_destroy(coal);
-}
-#endif
-
 /*
  *     _            _               _____       _   _ _   _
  *    / \   ___ ___(_) __ _ _ __   | ____|_ __ | |_(_) |_(_) ___  ___
@@ -461,14 +405,14 @@ static void do_java_coalescing(ss_env_t *env)
 typedef struct _spill_slot_t {
 	int size;
 	int align;
-	entity   *entity;
+	ir_entity *entity;
 } spill_slot_t;
 
 typedef struct _memperm_entry_t {
 	ir_node* node;
 	int pos;
-	entity *in;
-	entity *out;
+	ir_entity *in;
+	ir_entity *out;
 	struct _memperm_entry_t *next;
 } memperm_entry_t;
 
@@ -478,18 +422,20 @@ typedef struct _memperm_t {
 	memperm_entry_t *entries;
 } memperm_t;
 
-static int cmp_memperm(const void* d1, const void* d2, size_t size) {
+static int cmp_memperm(const void* d1, const void* d2, size_t size)
+{
 	const memperm_t* e1 = d1;
 	const memperm_t* e2 = d2;
 	return e1->block != e2->block;
 }
 
-static memperm_t *get_memperm(ss_env_t *env, ir_node *block) {
+static memperm_t *get_memperm(be_fec_env_t *env, ir_node *block)
+{
 	memperm_t entry, *res;
 	int hash;
 
 	entry.block = block;
-	hash = HASH_PTR(block);
+	hash = nodeset_hash(block);
 
 	res = set_find(env->memperms, &entry, sizeof(entry), hash);
 
@@ -502,32 +448,27 @@ static memperm_t *get_memperm(ss_env_t *env, ir_node *block) {
 	return res;
 }
 
-static entity* create_stack_entity(ss_env_t *env, spill_slot_t *slot) {
-	ir_type* frame = get_irg_frame_type(env->chordal_env->irg);
-	entity* res = frame_alloc_area(frame, slot->size, slot->align, 0);
+static ir_entity* create_stack_entity(be_fec_env_t *env, spill_slot_t *slot)
+{
+	ir_graph *irg = be_get_birg_irg(env->birg);
+	ir_type *frame = get_irg_frame_type(irg);
+	ir_entity *res = frame_alloc_area(frame, slot->size, slot->align, 0);
+
+	// adjust size of the entity type...
+	ir_type *enttype = get_entity_type(res);
+	set_type_size_bytes(enttype, slot->size);
 
 	slot->entity = res;
 
 	return res;
 }
 
-static int get_spillslotsize_for_spill(ss_env_t *env, spill_t *spill) {
-	const ir_mode *mode = arch_register_class_mode(spill->cls);
-
-	return get_mode_size_bytes(mode);
-}
-
-static int get_spillslotalign_for_spill(ss_env_t *env, spill_t *spill) {
-	const arch_isa_t *isa = env->chordal_env->birg->main_env->arch_env->isa;
-
-	return arch_isa_get_reg_class_alignment(isa, spill->cls);
-}
-
 /**
  * Enlarges a spillslot (if necessary) so that it can carry a value of size
  * @p othersize and alignment @p otheralign.
  */
-static void enlarge_spillslot(spill_slot_t *slot, int otheralign, int othersize) {
+static void enlarge_spillslot(spill_slot_t *slot, int otheralign, int othersize)
+{
 	if(othersize > slot->size) {
 		slot->size = othersize;
 	}
@@ -545,7 +486,9 @@ static void enlarge_spillslot(spill_slot_t *slot, int otheralign, int othersize)
  * Create stack entities for the spillslots and assign them to the spill and
  * reload nodes.
  */
-static void assign_spillslots(ss_env_t *env) {
+static void assign_spillslots(be_fec_env_t *env)
+{
+	const arch_env_t *arch_env = env->arch_env;
 	int i;
 	int spillcount;
 	spill_t *spill;
@@ -559,9 +502,10 @@ static void assign_spillslots(ss_env_t *env) {
 	// construct spillslots
 	for(spill = set_first(env->spills); spill != NULL; spill = set_next(env->spills)) {
 		int slotid = spill->spillslot;
+		const ir_mode *mode = spill->mode;
 		spill_slot_t *slot = & (spillslots[slotid]);
-		int align = get_spillslotalign_for_spill(env, spill);
-		int size = get_spillslotsize_for_spill(env, spill);
+		int size = get_mode_size_bytes(mode);
+		int align = spill->alignment;
 
 		if(slot->align == 0 && slot->size == 0) {
 			slot->align = align;
@@ -581,16 +525,16 @@ static void assign_spillslots(ss_env_t *env) {
 			create_stack_entity(env, slot);
 		}
 
-		if(be_is_Spill(node)) {
-			be_set_frame_entity(node, slot->entity);
-		} else {
+		if(is_Phi(node)) {
 			int i, arity;
+			ir_node *block = get_nodes_block(node);
 
 			// should be a PhiM
 			assert(is_Phi(node));
 
 			for(i = 0, arity = get_irn_arity(node); i < arity; ++i) {
 				ir_node *arg = get_irn_n(node, i);
+				ir_node *predblock = get_Block_cfgpred_block(block, i);
 				spill_t *argspill;
 				int argslotid;
 
@@ -606,7 +550,7 @@ static void assign_spillslots(ss_env_t *env) {
 						create_stack_entity(env, argslot);
 					}
 
-					memperm = get_memperm(env, get_nodes_block(arg));
+					memperm = get_memperm(env, predblock);
 
 					entry = obstack_alloc(&env->obst, sizeof(entry[0]));
 					entry->node = node;
@@ -618,27 +562,56 @@ static void assign_spillslots(ss_env_t *env) {
 					memperm->entries = entry;
 				}
 			}
+		} else {
+			arch_set_frame_entity(arch_env, node, slot->entity);
 		}
 	}
 
 	for(i = 0; i < ARR_LEN(env->reloads); ++i) {
-		const ir_node* reload = env->reloads[i];
-		ir_node* spillnode = get_irn_n(reload, be_pos_Reload_mem);
+		ir_node* reload = env->reloads[i];
+		ir_node* spillnode = get_memory_edge(reload);
 		spill_t *spill = get_spill(env, spillnode);
 		const spill_slot_t *slot = & spillslots[spill->spillslot];
 
 		assert(slot->entity != NULL);
 
-		be_set_frame_entity(reload, slot->entity);
+		arch_set_frame_entity(arch_env, reload, slot->entity);
 	}
 }
 
-static void create_memperms(ss_env_t *env) {
+/**
+ * Returns the last node in a block which is no control flow changing node
+ */
+static ir_node *get_end_of_block_insertion_point(ir_node* block)
+{
+	ir_node* ins = sched_last(block);
+	while(is_Proj(ins) && get_irn_mode(ins) == mode_X) {
+		ins = sched_prev(ins);
+		assert(ins != NULL);
+	}
+
+	if(is_cfop(ins)) {
+		while(1) {
+			ir_node *prev = sched_prev(ins);
+			if(!is_cfop(prev))
+				break;
+			ins = prev;
+		}
+	}
+
+	return ins;
+}
+
+static void create_memperms(be_fec_env_t *env)
+{
+	const arch_env_t *arch_env = env->arch_env;
+	ir_graph *irg = be_get_birg_irg(env->birg);
 	memperm_t *memperm;
 
 	for(memperm = set_first(env->memperms); memperm != NULL; memperm = set_next(env->memperms)) {
 		int i;
 		memperm_entry_t *entry;
+		ir_node *blockend;
 		ir_node** nodes = alloca(memperm->entrycount * sizeof(nodes[0]));
 		ir_node* mempermnode;
 
@@ -649,50 +622,136 @@ static void create_memperms(ss_env_t *env) {
 			nodes[i] = arg;
 		}
 
-		mempermnode = be_new_MemPerm(env->chordal_env->birg->main_env->arch_env, env->chordal_env->irg, memperm->block,
-			memperm->entrycount, nodes);
+		mempermnode = be_new_MemPerm(arch_env, irg, memperm->block,
+		                             memperm->entrycount, nodes);
 
-		for(entry = memperm->entries, i = 0; entry != NULL; entry = entry->next, ++i) {
+		// insert node into schedule
+		blockend = get_end_of_block_insertion_point(memperm->block);
+		sched_add_before(blockend, mempermnode);
+		be_stat_ev("mem_perm", memperm->entrycount);
+
+		i = 0;
+		for(entry = memperm->entries; entry != NULL; entry = entry->next, ++i) {
 			ir_node *proj;
 			ir_node* arg = get_irn_n(entry->node, entry->pos);
 
 			be_set_MemPerm_in_entity(mempermnode, i, entry->in);
 			be_set_MemPerm_out_entity(mempermnode, i, entry->out);
+			set_irg_current_block(irg, memperm->block);
 			proj = new_Proj(mempermnode, get_irn_mode(arg), i);
+			sched_add_before(blockend, proj);
+
 			set_irn_n(entry->node, entry->pos, proj);
 		}
+	}
+}
 
-		// insert node into schedule
-		sched_add_before(sched_last(memperm->block), mempermnode);
+static int count_spillslots(const be_fec_env_t *env)
+{
+	const spill_t *spill;
+	int spillcount = set_count(env->spills);
+	bitset_t *counted = bitset_alloca(spillcount);
+	int slotcount;
+
+	slotcount = 0;
+	for(spill = set_first(env->spills); spill != NULL;
+	    spill = set_next(env->spills)) {
+		int spillslot = spill->spillslot;
+		if(!bitset_is_set(counted, spillslot)) {
+			slotcount++;
+			bitset_set(counted, spillslot);
+		}
 	}
+
+	return slotcount;
 }
 
-void be_coalesce_spillslots(const be_chordal_env_t *chordal_env) {
-	ss_env_t env;
+be_fec_env_t *be_new_frame_entity_coalescer(be_irg_t *birg)
+{
+	const arch_env_t *arch_env = birg->main_env->arch_env;
+
+	be_fec_env_t *env = xmalloc(sizeof(env[0]));
 
-	obstack_init(&env.obst);
-	env.chordal_env = chordal_env;
-	env.spills = new_set(cmp_spill, 10);
-	env.reloads = NEW_ARR_F(ir_node*, 0);
-	env.affinity_edges = NEW_ARR_F(affinity_edge_t*, 0);
-	env.memperms = new_set(cmp_memperm, 10);
+	be_assure_liveness(birg);
+
+	obstack_init(&env->obst);
+	env->arch_env = arch_env;
+	env->birg = birg;
+	env->spills = new_set(cmp_spill, 10);
+	env->reloads = NEW_ARR_F(ir_node*, 0);
+	env->affinity_edges = NEW_ARR_F(affinity_edge_t*, 0);
+	env->memperms = new_set(cmp_memperm, 10);
 	FIRM_DBG_REGISTER(dbg, "firm.be.spillslots");
-	//firm_dbg_set_mask(dbg, DBG_COALESCING);
 
-	/* Get initial spill slots */
-	irg_walk_graph(chordal_env->irg, NULL, collect_spills_walker, &env);
+	return env;
+}
+
+void be_free_frame_entity_coalescer(be_fec_env_t *env)
+{
+	del_set(env->memperms);
+	DEL_ARR_F(env->reloads);
+	DEL_ARR_F(env->affinity_edges);
+	del_set(env->spills);
+	obstack_free(&env->obst, NULL);
+
+	free(env);
+}
+
+void be_assign_entities(be_fec_env_t *env)
+{
+	if(be_stat_ev_is_active()) {
+		int count = set_count(env->spills);
+		be_stat_ev("spillslots", count);
+	}
 
-	do_greedy_coalescing(&env);
+	if(be_coalesce_spill_slots) {
+		do_greedy_coalescing(env);
+	}
+
+	if(be_stat_ev_is_active()) {
+		int count = count_spillslots(env);
+		be_stat_ev("spillslots_after_coalescing", count);
+	}
 
-	assign_spillslots(&env);
+	assign_spillslots(env);
+
+	create_memperms(env);
+}
+
+/**
+ * This walker function searches for reloads and collects all the spills
+ * and memphis attached to them.
+ */
+static void collect_spills_walker(ir_node *node, void *data)
+{
+	be_fec_env_t *env = data;
+	const arch_env_t *arch_env = env->arch_env;
+	const ir_mode *mode;
+	const arch_register_class_t *cls;
+	int align;
+
+	/* classify returns classification of the irn the proj is attached to */
+	if (is_Proj(node))
+		return;
+
+	if (!arch_irn_class_is(arch_env, node, reload))
+		return;
+
+	mode = get_irn_mode(node);
+	cls = arch_get_irn_reg_class(arch_env, node, -1);
+	align = arch_isa_get_reg_class_alignment(arch_env_get_isa(arch_env), cls);
+
+	be_node_needs_frame_entity(env, node, mode, align);
+}
+
+void be_coalesce_spillslots(const be_chordal_env_t *chordal_env)
+{
+	be_fec_env_t *env = be_new_frame_entity_coalescer(chordal_env->birg);
 
-	create_memperms(&env);
+	/* collect reloads */
+	irg_walk_graph(chordal_env->irg, NULL, collect_spills_walker, env);
 
-	//show_stats(&env);
+	be_assign_entities(env);
 
-	del_set(env.memperms);
-	DEL_ARR_F(env.reloads);
-	DEL_ARR_F(env.affinity_edges);
-	del_set(env.spills);
-	obstack_free(&env.obst, NULL);
+	be_free_frame_entity_coalescer(env);
 }