X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbespillmorgan.c;h=e931929faca938e2494353503957623d6e50bd4b;hb=39d4311ea8a4f1bd78d1e0282d77d71f7ef4efdb;hp=86c03423e20c33b7fb9a74278104e1b255421fc1;hpb=eb285d9224370de02302b8191132928add5a3318;p=libfirm

diff --git a/ir/be/bespillmorgan.c b/ir/be/bespillmorgan.c
index 86c03423e..e931929fa 100644
--- a/ir/be/bespillmorgan.c
+++ b/ir/be/bespillmorgan.c
@@ -1,45 +1,67 @@
 /*
- * Author:      Matthias Braun
- * Date:		05.05.2006
- * Copyright:   (c) Universitaet Karlsruhe
- * License:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
+ * Copyright (C) 1995-2007 University of Karlsruhe.  All right reserved.
  *
+ * This file is part of libFirm.
+ *
+ * This file may be distributed and/or modified under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation and appearing in the file LICENSE.GPL included in the
+ * packaging of this file.
+ *
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+ * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE.
+ */
+
+/**
+ * @file
+ * @brief       Morgans spill algorithm.
+ * @author      Matthias Braun
+ * @date        05.05.2006
+ * @version     $Id$
  */
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
-#include "bespillmorgan.h"
-
-#include "bechordal.h"
-#include "bechordal_t.h"
-#include "bespill.h"
-#include "belive.h"
-#include "belive_t.h"
 #include "irgwalk.h"
-#include "besched.h"
-#include "beutil.h"
-#include "irloop.h"
 #include "irloop_t.h"
-#include "irgraph.h"
 #include "irgraph_t.h"
-#include "irphase.h"
-#include "irphase_t.h"
 #include "irprintf.h"
+#include "obst.h"
 
+#include "bespillmorgan.h"
+#include "bechordal_t.h"
+#include "bespill.h"
+#include "belive_t.h"
+#include "beabi.h"
 #include "bespillbelady.h"
 #include "beverify.h"
+#include "benodesets.h"
+#include "bespilloptions.h"
+#include "besched.h"
+#include "beutil.h"
+#include "bemodule.h"
+#include "beirg_t.h"
 
 #define DBG_LIVE		1
-#define DBG_PRESSURE	2
+#define DBG_LOOPANA		2
+#define DBG_PRESSURE	4
+#define DBG_SPILLS      8
+#define DBG_CHOOSE		16
 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
 
-typedef struct _morgan_env_t {
+typedef struct morgan_env {
 	const arch_env_t *arch;
 	const arch_register_class_t *cls;
 	ir_graph *irg;
-	phase_t phase;
-	// maximum safe register pressure
+	const be_lv_t *lv;
+	struct obstack obst;
+	/** maximum safe register pressure */
 	int registers_available;
 
 	spill_env_t *senv;
@@ -48,40 +70,42 @@ typedef struct _morgan_env_t {
 	set *block_attr_set;
 } morgan_env_t;
 
-typedef struct _loop_out_edge_t {
+typedef struct loop_edge {
 	ir_node *block;
 	int pos;
-} loop_out_edge_t;
+} loop_edge_t;
 
-typedef struct _loop_attr_t {
-	ir_loop *loop;
+typedef struct loop_attr {
+	const ir_loop *loop;
 	set *out_edges;
-	/// The set of all values that live through the loop and are not used
+	set *in_edges;
+	/** The set of all values that are live in the loop but not used in the loop */
 	bitset_t *livethrough_unused;
 } loop_attr_t;
 
-typedef struct _block_attr_t {
-	ir_node *block;
+typedef struct morgan_block_attr {
+	const ir_node *block;
+	/** set of all values that are live in the block but not used in the block */
 	bitset_t *livethrough_unused;
 } block_attr_t;
 
 //---------------------------------------------------------------------------
 
-int loop_out_edge_cmp(const void* p1, const void* p2, size_t s) {
-	loop_out_edge_t *e1 = (loop_out_edge_t*) p1;
-	loop_out_edge_t *e2 = (loop_out_edge_t*) p2;
+static int loop_edge_cmp(const void* p1, const void* p2, size_t s) {
+	loop_edge_t *e1 = (loop_edge_t*) p1;
+	loop_edge_t *e2 = (loop_edge_t*) p2;
 
 	return e1->block != e2->block || e1->pos != e2->pos;
 }
 
-int loop_attr_cmp(const void *e1, const void *e2, size_t s) {
+static int loop_attr_cmp(const void *e1, const void *e2, size_t s) {
 	loop_attr_t *la1 = (loop_attr_t*) e1;
 	loop_attr_t *la2 = (loop_attr_t*) e2;
 
 	return la1->loop != la2->loop;
 }
 
-int block_attr_cmp(const void *e1, const void *e2, size_t s) {
+static int block_attr_cmp(const void *e1, const void *e2, size_t s) {
 	block_attr_t *b1 = (block_attr_t*) e1;
 	block_attr_t *b2 = (block_attr_t*) e2;
 
@@ -89,18 +113,22 @@ int block_attr_cmp(const void *e1, const void *e2, size_t s) {
 }
 
 static INLINE int loop_attr_hash(const loop_attr_t *a) {
+#ifdef DEBUG_libfirm
+	return a->loop->loop_nr;
+#else
 	return HASH_PTR(a->loop);
+#endif
 }
 
 static INLINE int block_attr_hash(const block_attr_t *b) {
-	return HASH_PTR(b->block);
+	return nodeset_hash(b->block);
 }
 
-static INLINE int loop_out_edge_hash(const loop_out_edge_t *e) {
-	return HASH_PTR(e->block) ^ (e->pos * 31);
+static INLINE int loop_edge_hash(const loop_edge_t *e) {
+	return nodeset_hash(e->block) ^ (e->pos * 31);
 }
 
-static INLINE loop_attr_t *get_loop_attr(morgan_env_t *env, ir_loop *loop) {
+static INLINE loop_attr_t *get_loop_attr(morgan_env_t *env, const ir_loop *loop) {
 	loop_attr_t l_attr, *res;
 	int hash;
 	l_attr.loop = loop;
@@ -109,16 +137,17 @@ static INLINE loop_attr_t *get_loop_attr(morgan_env_t *env, ir_loop *loop) {
 	res = set_find(env->loop_attr_set, &l_attr, sizeof(l_attr), hash);
 
 	// create new loop_attr if none exists yet
-	if (!res) {
-		l_attr.out_edges = new_set(loop_out_edge_cmp, 1);
-		l_attr.livethrough_unused = bitset_obstack_alloc(&env->phase.obst, get_irg_last_idx(env->irg));
+	if (res == NULL) {
+		l_attr.out_edges = new_set(loop_edge_cmp, 1);
+		l_attr.in_edges = new_set(loop_edge_cmp, 1);
+		l_attr.livethrough_unused = bitset_obstack_alloc(&env->obst, get_irg_last_idx(env->irg));
 		res = set_insert(env->loop_attr_set, &l_attr, sizeof(l_attr), hash);
 	}
 
 	return res;
 }
 
-static INLINE block_attr_t *get_block_attr(morgan_env_t *env, ir_node *block) {
+static INLINE block_attr_t *get_block_attr(morgan_env_t *env, const ir_node *block) {
 	block_attr_t b_attr, *res;
 	int hash;
 	b_attr.block = block;
@@ -126,8 +155,8 @@ static INLINE block_attr_t *get_block_attr(morgan_env_t *env, ir_node *block) {
 	hash = block_attr_hash(&b_attr);
 	res = set_find(env->block_attr_set, &b_attr, sizeof(b_attr), hash);
 
-	if(!res) {
-		b_attr.livethrough_unused = bitset_obstack_alloc(&env->phase.obst, get_irg_last_idx(env->irg));
+	if(res == NULL) {
+		b_attr.livethrough_unused = NULL;
 		res = set_insert(env->block_attr_set, &b_attr, sizeof(b_attr), hash);
 	}
 
@@ -136,71 +165,147 @@ static INLINE block_attr_t *get_block_attr(morgan_env_t *env, ir_node *block) {
 
 //---------------------------------------------------------------------------
 
+static INLINE int consider_for_spilling(const arch_env_t *env, const arch_register_class_t *cls, const ir_node *node) {
+	if(!arch_irn_has_reg_class(env, node, -1, cls))
+		return 0;
+
+	return !(arch_irn_get_flags(env, node) & (arch_irn_flags_ignore | arch_irn_flags_dont_spill));
+}
+
 /**
- * Determine edges going out of a loop (= edges that go to a block that is not inside
- * the loop or one of its subloops)
+ * Determine edges going out of a loop (= edges that go to a block that is not
+ * inside the loop or one of its subloops)
  */
-static INLINE void construct_loop_out_edges(ir_node* block, void* e) {
-	morgan_env_t *env = (morgan_env_t*) e;
+static INLINE void construct_loop_edges(ir_node *block, void *data) {
+	morgan_env_t *env = data;
 	int n_cfgpreds = get_Block_n_cfgpreds(block);
 	int i;
 	ir_loop* loop = get_irn_loop(block);
+	DBG((dbg, DBG_LOOPANA, "Loop for %+F: %d (depth %d)\n", block, loop->loop_nr, loop->depth));
 
 	for(i = 0; i < n_cfgpreds; ++i) {
+		loop_edge_t edge;
+		int hash;
 		ir_node* cfgpred = get_Block_cfgpred(block, i);
 		ir_node* cfgpred_block = get_nodes_block(cfgpred);
 		ir_loop* cfgpred_loop = get_irn_loop(cfgpred_block);
-		loop_attr_t *outedges = get_loop_attr(env, cfgpred_loop);
 
-		if(cfgpred_loop != loop && get_loop_depth(cfgpred_loop) >= get_loop_depth(loop)) {
-			loop_out_edge_t edge;
-			edge.block = block;
-			edge.pos = i;
-			set_insert(outedges->out_edges, &edge, sizeof(edge), loop_out_edge_hash(&edge));
+		if(cfgpred_loop == loop)
+			continue;
+
+		assert(get_loop_depth(cfgpred_loop) != get_loop_depth(loop));
+
+		edge.block = block;
+		edge.pos = i;
+		hash = loop_edge_hash(&edge);
+
+		// edge out of a loop?
+		if(get_loop_depth(cfgpred_loop) > get_loop_depth(loop)) {
+			ir_loop *l;
+
+			DBG((dbg, DBG_LOOPANA, "Loop out edge from %+F (loop %d) to %+F (loop %d)\n", block, get_loop_loop_nr(loop),
+			     cfgpred_block, get_loop_loop_nr(cfgpred_loop)));
+
+			/* this might be a jump out of multiple loops, so add this to all
+		     * needed outedge sets */
+			l = cfgpred_loop;
+			do {
+				loop_attr_t *l_attr = get_loop_attr(env, l);
+				set_insert(l_attr->out_edges, &edge, sizeof(edge), hash);
+
+				l = get_loop_outer_loop(l);
+				assert(l != NULL);
+			} while(l != loop);
+		} else {
+			ir_loop *l;
+
+			// edge into a loop
+			DBG((dbg, DBG_LOOPANA, "Loop in edge from %+F (loop %d) to %+F (loop %d)\n", block, get_loop_loop_nr(loop),
+			     cfgpred_block, get_loop_loop_nr(cfgpred_loop)));
+
+			l = loop;
+			do {
+				loop_attr_t *l_attr = get_loop_attr(env, l);
+				set_insert(l_attr->in_edges, &edge, sizeof(edge), hash);
+
+				l = get_loop_outer_loop(l);
+			} while(l != cfgpred_loop);
 		}
 	}
 }
 
-static void free_loop_out_edges(morgan_env_t *env) {
+static void free_loop_edges(morgan_env_t *env) {
 	loop_attr_t *l_attr;
 
 	for(l_attr = set_first(env->loop_attr_set); l_attr != NULL; l_attr = set_next(env->loop_attr_set)) {
 		del_set(l_attr->out_edges);
+		del_set(l_attr->in_edges);
 	}
 }
 
+#if 0
 /**
  * Debugging help, shows all nodes in a (node-)bitset
  */
-static void show_nodebitset(ir_graph* irg, bitset_t* bitset) {
+static void show_nodebitset(ir_graph* irg, const bitset_t* bitset) {
 	int i;
 
 	bitset_foreach(bitset, i) {
 		ir_node* node = get_idx_irn(irg, i);
-		DBG((dbg, DBG_LIVE, "\t%+F\n", node));
+		ir_fprintf(stderr, " %+F", node);
+	}
+	fprintf(stderr, "\n");
+}
+#endif
+
+static INLINE void init_livethrough_unuseds(block_attr_t *attr, morgan_env_t *env) {
+	const ir_node *block;
+	int i;
+	const be_lv_t *lv = env->lv;
+
+	if(attr->livethrough_unused != NULL)
+		return;
+
+	block = attr->block;
+
+	attr->livethrough_unused = bitset_obstack_alloc(&env->obst, get_irg_last_idx(env->irg));
+
+	// copy all live-outs into the livethrough_unused set
+	be_lv_foreach(lv, block, be_lv_state_in | be_lv_state_out, i) {
+		ir_node *irn = be_lv_get_irn(lv, block, i);
+		int node_idx;
+
+		if(!consider_for_spilling(env->arch, env->cls, irn))
+			continue;
+
+		node_idx = get_irn_idx(irn);
+		bitset_set(attr->livethrough_unused, node_idx);
 	}
 }
 
 /**
  * Construct the livethrough unused set for a block
  */
-static bitset_t *construct_block_livethrough_unused(morgan_env_t* env, ir_node* block) {
+static void construct_block_livethrough_unused(ir_node *block, void *data) {
+	morgan_env_t* env = data;
 	block_attr_t *block_attr = get_block_attr(env, block);
-	irn_live_t *li;
 	ir_node *node;
+	int n_cfgpreds;
+	block_attr_t **pred_attrs = NULL;
+	int i;
 
-	DBG((dbg, DBG_LIVE, "Processing block %d\n", get_irn_node_nr(block)));
-	// copy all live-outs into the livethrough_unused set
-	live_foreach(block, li) {
-		int node_idx;
+	init_livethrough_unuseds(block_attr, env);
 
-		if(!live_is_in(li) || !live_is_out(li))
-			continue;
-		if(!arch_irn_consider_in_reg_alloc(env->arch, env->cls, li->irn))
-			continue;
+	DBG((dbg, DBG_LIVE, "Processing block %d\n", get_irn_node_nr(block)));
 
-		node_idx = get_irn_idx(li->irn);
-		bitset_set(block_attr->livethrough_unused, node_idx);
+	n_cfgpreds = get_Block_n_cfgpreds(block);
+	if(n_cfgpreds > 1) {
+		pred_attrs = alloca(sizeof(pred_attrs[0]) * n_cfgpreds);
+		for(i = 0; i < n_cfgpreds; ++i) {
+			ir_node *pred_block = get_Block_cfgpred_block(block, i);
+			pred_attrs[i] = get_block_attr(env, pred_block);
+			init_livethrough_unuseds(pred_attrs[i], env);
+		}
 	}
 
 	/*
@@ -210,20 +315,30 @@ static bitset_t *construct_block_livethrough_unused(morgan_env_t* env, ir_node*
 	sched_foreach(block, node) {
 		int i, arity;
 
-		for(i = 0, arity = get_irn_arity(node); i < arity; ++i) {
-			int idx = get_irn_idx(get_irn_n(node, i));
-			bitset_clear(block_attr->livethrough_unused, idx);
+		// phis are really uses in the pred block
+		if(is_Phi(node)) {
+			int j;
+			for(j = 0; j < n_cfgpreds; ++j) {
+				ir_node *used_value = get_Phi_pred(node, j);
+				int idx = get_irn_idx(used_value);
+				block_attr_t *pred_attr = pred_attrs[j];
+
+				bitset_clear(pred_attr->livethrough_unused, idx);
+			}
+		} else {
+			// mark all used values as used
+			for(i = 0, arity = get_irn_arity(node); i < arity; ++i) {
+				int idx = get_irn_idx(get_irn_n(node, i));
+				bitset_clear(block_attr->livethrough_unused, idx);
+			}
 		}
 	}
-
-	show_nodebitset(env->irg, block_attr->livethrough_unused);
-	return block_attr->livethrough_unused;
 }
 
 /**
  * Construct the livethrough unused set for a loop (and all its subloops+blocks)
  */
-static bitset_t *construct_loop_livethrough_unused(morgan_env_t *env, ir_loop *loop) {
+static bitset_t *construct_loop_livethrough_unused(morgan_env_t *env, const ir_loop *loop) {
 	int i;
 	loop_attr_t* loop_attr = get_loop_attr(env, loop);
 
@@ -233,9 +348,13 @@ static bitset_t *construct_loop_livethrough_unused(morgan_env_t *env, ir_loop *l
 		loop_element elem = get_loop_element(loop, i);
 		switch (*elem.kind) {
 		case k_ir_node: {
-			bitset_t *livethrough_block_unused;
+			ir_node *block = elem.node;
+			block_attr_t *block_attr = get_block_attr(env, block);
+			bitset_t *livethrough_block_unused = block_attr->livethrough_unused;
+
 			assert(is_Block(elem.node));
-			livethrough_block_unused = construct_block_livethrough_unused(env, elem.node);
+			assert(livethrough_block_unused != NULL);
+
 			if(i == 0) {
 				bitset_copy(loop_attr->livethrough_unused, livethrough_block_unused);
 			} else {
@@ -270,13 +389,11 @@ static bitset_t *construct_loop_livethrough_unused(morgan_env_t *env, ir_loop *l
 			bitset_andnot(son_attr->livethrough_unused, loop_attr->livethrough_unused);
 
 			DBG((dbg, DBG_LIVE, "Livethroughs for loop %d:\n", loop->loop_nr));
-			show_nodebitset(env->irg, son_attr->livethrough_unused);
 		} else if(*elem.kind == k_ir_node) {
 			block_attr_t *block_attr = get_block_attr(env, elem.node);
 			bitset_andnot(block_attr->livethrough_unused, loop_attr->livethrough_unused);
 
 			DBG((dbg, DBG_LIVE, "Livethroughs for block %+F\n", elem.node));
-			show_nodebitset(env->irg, block_attr->livethrough_unused);
 		} else {
 			assert(0);
 		}
@@ -285,98 +402,100 @@ static bitset_t *construct_loop_livethrough_unused(morgan_env_t *env, ir_loop *l
 	return loop_attr->livethrough_unused;
 }
 
-//---------------------------------------------------------------------------
+/*---------------------------------------------------------------------------*/
+
+typedef struct _spillcandidate_t {
+	ir_node *node;
+	int cost;
+} spillcandidate_t;
+
+static int compare_spillcandidates(const void *d1, const void *d2) {
+	const spillcandidate_t *cand1 = d1;
+	const spillcandidate_t *cand2 = d2;
+
+	return cand1->cost - cand2->cost;
+}
+
+static void spill_values(morgan_env_t *env, const loop_attr_t *loop_attr, int spills) {
+	const bitset_t *cand_bitset = loop_attr->livethrough_unused;
+	int candidatecount = bitset_popcnt(cand_bitset);
+	spillcandidate_t *candidates;
+	int i, c;
+	loop_edge_t *edge;
+
+	assert(spills <= candidatecount);
+
+	candidates = alloca(sizeof(candidates[0]) * candidatecount);
+
+	DBG((dbg, DBG_CHOOSE, "Candidates for loop %d\n", get_loop_loop_nr(loop_attr->loop)));
+	// build candidiatelist
+	c = 0;
+	bitset_foreach(cand_bitset, i) {
+		ir_node *node = get_idx_irn(env->irg, i);
+		candidates[c].node = node;
+		candidates[c].cost = 0;
 
-static int reduce_register_pressure_in_block(morgan_env_t *env, ir_node* block, int loop_unused_spills_possible) {
-	int pressure;
-	ir_node *irn;
-	int max_pressure = 0;
-	int spills_needed;
+		for(edge = set_first(loop_attr->out_edges); edge != NULL; edge = set_next(loop_attr->out_edges)) {
+			candidates[c].cost += be_get_reload_costs_on_edge(env->senv, node, edge->block, edge->pos);
+		}
+		DBG((dbg, DBG_CHOOSE, "%+F has costs %d\n", node, candidates[c].cost));
+
+		c++;
+	}
+	assert(c == candidatecount);
+
+	// sort list
+	qsort(candidates, candidatecount, sizeof(candidates[0]), compare_spillcandidates);
+
+	// spill values
+	for(i = 0; i < spills; ++i) {
+		ir_node *to_spill = candidates[i].node;
+		DBG((dbg, DBG_CHOOSE, "Spilling %+F ", to_spill));
+
+		for(edge = set_first(loop_attr->out_edges); edge != NULL; edge = set_next(loop_attr->out_edges)) {
+			be_add_reload_on_edge(env->senv, to_spill, edge->block, edge->pos, env->cls, 1);
+		}
+	}
+}
+
+static int reduce_register_pressure_in_block(morgan_env_t *env, const ir_node* block, int loop_unused_spills_possible) {
+	ir_node *node;
+	int max_pressure;
 	int loop_unused_spills_needed;
-	block_attr_t *block_attr = get_block_attr(env, block);
-	int block_unused_spills_possible = bitset_popcnt(block_attr->livethrough_unused);
-	int unused_spills_possible = loop_unused_spills_possible + block_unused_spills_possible;
 	pset *live_nodes = pset_new_ptr_default();
+	const be_lv_t *lv = env->lv;
 
-	be_liveness_end_of_block(env->arch, env->cls, block, live_nodes);
-	pressure = pset_count(live_nodes);
+	be_liveness_end_of_block(lv, env->arch, env->cls, block, live_nodes);
+	max_pressure = pset_count(live_nodes);
 
 	DBG((dbg, DBG_LIVE, "Reduce pressure to %d In Block %+F:\n", env->registers_available, block));
 
 	/**
-	 * Walk over all irns in the schedule and check register pressure for each of them
+	 * Determine register pressure in block
 	 */
-	sched_foreach_reverse(block, irn) {
-		// do we need more spills than possible with unused libethroughs?
-		int spills_needed = pressure - unused_spills_possible - env->registers_available;
-		if(spills_needed > 0) {
-			DBG((dbg, DBG_PRESSURE, "\tWARNING %d more spills needed at %+F\n", spills_needed, irn));
-			// TODO further spills needed
-			//assert(0);
-		}
-		if(pressure > max_pressure) {
-			max_pressure = pressure;
-		}
+	sched_foreach_reverse(block, node) {
+		int pressure;
 
-		/* Register pressure is only important until we reach the first phi (the rest of the block
-		 * will only be phis.)
-		 */
-		if(is_Phi(irn))
+		if(is_Phi(node))
 			break;
 
-		// update pressure
-		{
-			int pressure_old = pressure;
-			be_liveness_transfer(env->arch, env->cls, irn, live_nodes);
-			pressure = pset_count(live_nodes);
-			DBG((dbg, DBG_PRESSURE, "\tPressure at %+F - before: %d after: %d\n", irn, pressure_old, pressure));
-		}
+		be_liveness_transfer(env->arch, env->cls, node, live_nodes);
+		pressure = pset_count(live_nodes);
+		if(pressure > max_pressure)
+			max_pressure = pressure;
 	}
+	del_pset(live_nodes);
 
-	/*
-	 * Calculate number of spills from loop_unused_spills_possible that we want to use,
-	 * and spill unused livethroughs from the block if we still don't have enough registers
-	 */
-	spills_needed = max_pressure - env->registers_available;
-	if(spills_needed < 0) {
-		loop_unused_spills_needed = 0;
-	} else if(spills_needed > loop_unused_spills_possible) {
-		int i, spills;
-		int block_unused_spills_needed;
+	loop_unused_spills_needed = max_pressure - env->registers_available;
 
+	if(loop_unused_spills_needed < 0) {
+		loop_unused_spills_needed = 0;
+	} else if(loop_unused_spills_needed > loop_unused_spills_possible) {
 		loop_unused_spills_needed = loop_unused_spills_possible;
-		block_unused_spills_needed = spills_needed - loop_unused_spills_possible;
-		if(block_unused_spills_needed > block_unused_spills_possible) {
-			block_unused_spills_needed = block_unused_spills_possible;
-		}
-
-		spills = 0;
-		/*
-		 * Spill/Reload unused livethroughs from the block
-		 */
-		bitset_foreach(block_attr->livethrough_unused, i) {
-			ir_node *to_spill;
-			const ir_edge_t *edge;
-
-			if(spills >= block_unused_spills_needed)
-				break;
-
-			to_spill = get_idx_irn(env->irg, i);
-			foreach_block_succ(block, edge) {
-				DBG((dbg, DBG_PRESSURE, "Spilling node %+F around block %+F\n", to_spill, block));
-				if(is_Phi(to_spill)) {
-					be_spill_phi(env->senv, to_spill);
-				}
-				be_add_reload_on_edge(env->senv, to_spill, edge->src, edge->pos);
-			}
-		}
-	} else {
-		loop_unused_spills_needed = spills_needed;
 	}
 
-	del_pset(live_nodes);
-
-	DBG((dbg, DBG_PRESSURE, "Unused spills for Block %+F needed: %d\n", block, loop_unused_spills_needed));
+	DBG((dbg, DBG_PRESSURE, "Block %+F: max-pressure %d spills possible: %d spills used: %d\n",
+		 block, max_pressure, loop_unused_spills_possible, loop_unused_spills_needed));
 	return loop_unused_spills_needed;
 }
 
@@ -386,7 +505,7 @@ static int reduce_register_pressure_in_block(morgan_env_t *env, ir_node* block,
  * @param unused_spills_possible	Number of spills from livethrough_unused variables possible in outer loops
  * @return							Number of spills of livethrough_unused variables needed in outer loops
  */
-static int reduce_register_pressure_in_loop(morgan_env_t *env, ir_loop *loop, int outer_spills_possible) {
+static int reduce_register_pressure_in_loop(morgan_env_t *env, const ir_loop *loop, int outer_spills_possible) {
 	int i;
 	loop_attr_t* loop_attr = get_loop_attr(env, loop);
 	int spills_needed = 0;
@@ -401,6 +520,7 @@ static int reduce_register_pressure_in_loop(morgan_env_t *env, ir_loop *loop, in
 			int needed;
 			assert(is_Block(elem.node));
 			needed = reduce_register_pressure_in_block(env, elem.node, spills_possible);
+			assert(needed >= 0);
 			assert(needed <= spills_possible);
 			if(needed > spills_needed)
 				spills_needed = needed;
@@ -408,6 +528,7 @@ static int reduce_register_pressure_in_loop(morgan_env_t *env, ir_loop *loop, in
 		}
 		case k_ir_loop: {
 			int needed = reduce_register_pressure_in_loop(env, elem.son, spills_possible);
+			assert(needed >= 0);
 			assert(needed <= spills_possible);
 			if(needed > spills_needed)
 				spills_needed = needed;
@@ -419,24 +540,19 @@ static int reduce_register_pressure_in_loop(morgan_env_t *env, ir_loop *loop, in
 		}
     }
 
-	// calculate number of spills needed in outer loop and spill
-	// unused livethrough nodes around this loop
+	/* calculate number of spills needed in outer loop and spill
+	 * unused livethrough nodes around this loop */
 	if(spills_needed > outer_spills_possible) {
+		int spills_to_place;
 		outer_spills_needed = outer_spills_possible;
 		spills_needed -= outer_spills_possible;
 
-		bitset_foreach(loop_attr->livethrough_unused, i) {
-			loop_out_edge_t *edge;
-			ir_node *to_spill = get_idx_irn(env->irg, i);
+		spills_to_place = spills_needed;
 
-			for(edge = set_first(loop_attr->out_edges); edge != NULL; edge = set_next(loop_attr->out_edges)) {
-				if(is_Phi(to_spill)) {
-					be_spill_phi(env->senv, to_spill);
-				}
+		DBG((dbg, DBG_SPILLS, "%d values unused in loop %d, spilling %d\n",
+	         spills_possible - outer_spills_possible, loop->loop_nr, spills_to_place));
 
-				be_add_reload_on_edge(env->senv, to_spill, edge->block, edge->pos);
-			}
-		}
+		spill_values(env, loop_attr, spills_to_place);
 	} else {
 		outer_spills_needed = spills_needed;
 	}
@@ -444,63 +560,73 @@ static int reduce_register_pressure_in_loop(morgan_env_t *env, ir_loop *loop, in
 	return outer_spills_needed;
 }
 
-static void *init_phase_data(phase_t *phase, ir_node *irn, void *old) {
-	return old;
-}
-
-void be_spill_morgan(const be_chordal_env_t *chordal_env) {
+void be_spill_morgan(be_irg_t *birg, const arch_register_class_t *cls) {
+	ir_graph     *irg = be_get_birg_irg(birg);
 	morgan_env_t env;
 
-	FIRM_DBG_REGISTER(dbg, "ir.be.spillmorgan");
+	be_assure_liveness(birg);
 
-	env.arch = chordal_env->birg->main_env->arch_env;
-	env.irg = chordal_env->irg;
-	env.cls = chordal_env->cls;
-	env.senv = be_new_spill_env(chordal_env);
-	DEBUG_ONLY(be_set_spill_env_dbg_module(env.senv, dbg);)
+	env.arch = birg->main_env->arch_env;
+	env.irg  = irg;
+	env.cls  = cls;
+	env.lv   = be_get_birg_liveness(birg);
+	env.senv = be_new_spill_env(birg);
 
-	phase_init(&env.phase, "spillmorgan", env.irg, PHASE_DEFAULT_GROWTH, init_phase_data);
+	obstack_init(&env.obst);
 
-	env.registers_available = arch_count_non_ignore_regs(env.arch, env.cls);
+	env.registers_available = env.cls->n_regs - be_put_ignore_regs(birg, env.cls, NULL);
 
-	env.loop_attr_set = new_set(loop_attr_cmp, 5);
+	env.loop_attr_set  = new_set(loop_attr_cmp, 5);
 	env.block_attr_set = new_set(block_attr_cmp, 20);
 
-	/*-- Part1: Analysis --*/
-	be_liveness(env.irg);
+	/* -- Part1: Analysis -- */
 
-	// construct control flow loop tree
-	construct_cf_backedges(chordal_env->irg);
+	/* construct control flow loop tree */
+	if (! (get_irg_loopinfo_state(irg) & loopinfo_cf_consistent)) {
+		construct_cf_backedges(irg);
+	}
 
-	// construct loop out edges and livethrough_unused sets for loops and blocks
-	irg_block_walk_graph(chordal_env->irg, construct_loop_out_edges, NULL, &env);
-	construct_loop_livethrough_unused(&env, get_irg_loop(env.irg));
+	/* construct loop out edges and livethrough_unused sets for loops and blocks */
+	irg_block_walk_graph(irg, construct_block_livethrough_unused, construct_loop_edges, &env);
+	construct_loop_livethrough_unused(&env, get_irg_loop(irg));
 
-	/*-- Part2: Transformation --*/
+	/* -- Part2: Transformation -- */
 
-	// reduce register pressure to number of available registers
-	reduce_register_pressure_in_loop(&env, get_irg_loop(env.irg), 0);
+	/* spill unused livethrough values around loops and blocks where
+	 * the pressure is too high
+	 */
+	reduce_register_pressure_in_loop(&env, get_irg_loop(irg), 0);
 
+	/* Insert real spill/reload nodes and fix usages */
 	be_insert_spills_reloads(env.senv);
-	if (chordal_env->opts->vrfy_option == BE_CH_VRFY_WARN) {
-		be_verify_schedule(env.irg);
-	} else if (chordal_env->opts->vrfy_option == BE_CH_VRFY_ASSERT) {
-		assert(be_verify_schedule(env.irg));
-	}
 
-	// we have to remove dead nodes from schedule to not confuse liveness calculation
-	be_remove_dead_nodes_from_schedule(env.irg);
+	/* Verify the result */
+	if (birg->main_env->options->vrfy_option == BE_VRFY_WARN) {
+		be_verify_schedule(birg);
+	} else if (birg->main_env->options->vrfy_option == BE_VRFY_ASSERT) {
+		assert(be_verify_schedule(birg));
+	}
 
-	// cleanup
-	be_dump(env.irg, "-spillmorgan", dump_ir_block_graph_sched);
-	free_loop_out_edges(&env);
+	/* cleanup */
+	free_loop_edges(&env);
 	del_set(env.loop_attr_set);
 	del_set(env.block_attr_set);
 
-	// fix the remaining places with too high register pressure with beladies algorithm
-	be_liveness(env.irg);
-	be_spill_belady_spill_env(chordal_env, env.senv);
+	/* fix the remaining places with too high register pressure with beladies algorithm */
+	be_spill_belady_spill_env(birg, cls, env.senv);
 
 	be_delete_spill_env(env.senv);
-	phase_free(&env.phase);
+	obstack_free(&env.obst, NULL);
 }
+
+void be_init_spillmorgan(void)
+{
+	static be_spiller_t morgan_spiller = {
+		be_spill_morgan
+	};
+
+	be_register_spiller("morgan", &morgan_spiller);
+	FIRM_DBG_REGISTER(dbg, "ir.be.spillmorgan");
+}
+
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spillmorgan);