X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbespill.c;h=577b56dfb4074365bae36e088be502611ba8e804;hb=75e3b5fe17402ca27fc671dd404ff958664506b1;hp=c2adba09fbf80ac43f0bfb98e18edaa83948301f;hpb=e2f37d0340ab4de1d7de4b1e0bdf3de081ef283e;p=libfirm

diff --git a/ir/be/bespill.c b/ir/be/bespill.c
index c2adba09f..577b56dfb 100644
--- a/ir/be/bespill.c
+++ b/ir/be/bespill.c
@@ -1,8 +1,28 @@
+/*
+ * 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.
+ */
+
 /**
- * Author:      Daniel Grund, Sebastian Hack
- * Date:		29.09.2005
- * Copyright:   (c) Universitaet Karlsruhe
- * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
+ * @file
+ * @brief       implementation of the spill/reload placement abstraction layer
+ * @author      Daniel Grund, Sebastian Hack, Matthias Braun
+ * @date		29.09.2005
+ * @version     $Id$
  */
 #ifdef HAVE_CONFIG_H
 #include "config.h"
@@ -14,6 +34,8 @@
 #include "irnode_t.h"
 #include "ircons_t.h"
 #include "iredges_t.h"
+#include "irbackedge_t.h"
+#include "irprintf.h"
 #include "ident_t.h"
 #include "type_t.h"
 #include "entity_t.h"
@@ -21,216 +43,406 @@
 #include "irgwalk.h"
 #include "array.h"
 #include "pdeq.h"
+#include "execfreq.h"
+#include "irnodeset.h"
 
+#include "bearch_t.h"
 #include "belive_t.h"
 #include "besched_t.h"
 #include "bespill.h"
+#include "belive_t.h"
 #include "benode_t.h"
 #include "bechordal_t.h"
+#include "bejavacoal.h"
+#include "benodesets.h"
+#include "bespilloptions.h"
+#include "bestatevent.h"
+#include "bessaconstr.h"
+#include "beirg_t.h"
+#include "beintlive_t.h"
+#include "bemodule.h"
 
-#define REMAT
-/* This enables re-computation of values. Current state: Unfinished and buggy. */
-#undef BUGGY_REMAT
+DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
 
-typedef struct _reloader_t reloader_t;
-typedef struct _spill_info_t spill_info_t;
+#define REMAT_COST_INFINITE  1000
 
-struct _reloader_t {
+typedef struct reloader_t reloader_t;
+struct reloader_t {
 	reloader_t *next;
-	ir_node *reloader;
+	ir_node    *can_spill_after;
+	ir_node    *reloader;
+	ir_node    *rematted_node;
+	int         remat_cost_delta; /** costs needed for rematerialization,
+	                                   compared to placing a reload */
 };
 
-struct _spill_info_t {
-	ir_node *spilled_node;
-	reloader_t *reloaders;
+typedef struct spill_info_t spill_info_t;
+struct spill_info_t {
+	ir_node    *to_spill;  /**< the value that should get spilled */
+	reloader_t *reloaders; /**< list of places where the value should get
+	                            reloaded */
+	ir_node    *spill;     /**< the spill node, or a PhiM node */
+	ir_node    *old_spill; /**< if we had the value of a phi spilled before but
+	                            not the phi itself then this field contains the
+	                            spill for the phi value */
+	const arch_register_class_t *reload_cls; /** the register class in which the
+	                                             reload should be placed */
 };
 
-typedef struct _spill_ctx_t {
-	ir_node *spilled;  /**< The spilled node. */
-	ir_node *user;     /**< The node this spill is for. */
-	ir_node *spill;    /**< The spill itself. */
-} spill_ctx_t;
-
-struct _spill_env_t {
-	const arch_register_class_t *cls;
-	const be_chordal_env_t *chordal_env;
-	struct obstack obst;
-	set *spill_ctxs;
-	set *spills;				/**< all spill_info_t's, which must be placed */
-	pset *mem_phis;				/**< set of all special spilled phis. allocated and freed separately */
-	ir_node **copies;			/**< set of copies placed because of phi spills */
-	DEBUG_ONLY(firm_dbg_module_t *dbg;)
+struct spill_env_t {
+	const arch_env_t *arch_env;
+	ir_graph         *irg;
+	struct obstack    obst;
+	be_irg_t         *birg;
+	int               spill_cost;     /**< the cost of a single spill node */
+	int               reload_cost;    /**< the cost of a reload node */
+	set              *spills;         /**< all spill_info_t's, which must be
+	                                       placed */
+	ir_nodeset_t      mem_phis;       /**< set of all spilled phis. */
+	ir_exec_freq     *exec_freq;
+
+#ifdef FIRM_STATISTICS
+	unsigned          spill_count;
+	unsigned          reload_count;
+	unsigned          remat_count;
+	unsigned          spilled_phi_count;
+#endif
 };
 
-/* associated Phi -> Spill*/
-typedef struct _phi_spill_assoc_t {
-	ir_node *phi;
-	ir_node *spill;
-} phi_spill_assoc_t;
-
 /**
- * Compare two Phi->Spill associations.
+ * Compare two spill infos.
  */
-static int cmp_phi_spill_assoc(const void *a, const void *b, size_t n) {
-	const phi_spill_assoc_t *p1 = a;
-	const phi_spill_assoc_t *p2 = b;
-	return p1->phi != p2->phi;
-}
+static
+int cmp_spillinfo(const void *x, const void *y, size_t size)
+{
+	const spill_info_t *xx = x;
+	const spill_info_t *yy = y;
+	(void) size;
 
-/**
- * compare two spill contexts.
- */
-static int cmp_spillctx(const void *a, const void *b, size_t n) {
-	const spill_ctx_t *p = a;
-	const spill_ctx_t *q = b;
-	return p->user != q->user || p->spilled != q->spilled;
+	return xx->to_spill != yy->to_spill;
 }
 
 /**
- * Compare two spill infos.
+ * Returns spill info for a specific value (the value that is to be spilled)
  */
-static int cmp_spillinfo(const void *x, const void *y, size_t size) {
-	const spill_info_t *xx = x;
-	const spill_info_t *yy = y;
-	return xx->spilled_node != yy->spilled_node;
-}
+static
+spill_info_t *get_spillinfo(const spill_env_t *env, ir_node *value)
+{
+	spill_info_t info, *res;
+	int hash = nodeset_hash(value);
+
+	info.to_spill = value;
+	res = set_find(env->spills, &info, sizeof(info), hash);
+
+	if (res == NULL) {
+		info.reloaders = NULL;
+		info.spill = NULL;
+		info.old_spill = NULL;
+		info.reload_cls = NULL;
+		res = set_insert(env->spills, &info, sizeof(info), hash);
+	}
 
-DEBUG_ONLY(
-/* Sets the debug module of a spill environment. */
-void be_set_spill_env_dbg_module(spill_env_t *env, firm_dbg_module_t *dbg) {
-	env->dbg = dbg;
+	return res;
 }
-)
 
-/* Creates a new spill environment. */
-spill_env_t *be_new_spill_env(const be_chordal_env_t *chordal_env) {
+spill_env_t *be_new_spill_env(be_irg_t *birg)
+{
+	const arch_env_t *arch_env = birg->main_env->arch_env;
+
 	spill_env_t *env	= xmalloc(sizeof(env[0]));
-	env->spill_ctxs		= new_set(cmp_spillctx, 1024);
 	env->spills			= new_set(cmp_spillinfo, 1024);
-	env->cls			= chordal_env->cls;
-	env->chordal_env	= chordal_env;
-	env->mem_phis		= pset_new_ptr_default();
-	env->copies			= NEW_ARR_F(ir_node*, 0);
+	env->irg            = be_get_birg_irg(birg);
+	env->birg           = birg;
+	env->arch_env       = arch_env;
+	ir_nodeset_init(&env->mem_phis);
+	env->spill_cost     = arch_env->isa->spill_cost;
+	env->reload_cost    = arch_env->isa->reload_cost;
+	env->exec_freq      = be_get_birg_exec_freq(birg);
 	obstack_init(&env->obst);
+
+#ifdef FIRM_STATISTICS
+	env->spill_count       = 0;
+	env->reload_count      = 0;
+	env->remat_count       = 0;
+	env->spilled_phi_count = 0;
+#endif
+
 	return env;
 }
 
-/* Deletes a spill environment. */
-void be_delete_spill_env(spill_env_t *env) {
-	del_set(env->spill_ctxs);
+void be_delete_spill_env(spill_env_t *env)
+{
 	del_set(env->spills);
-	del_pset(env->mem_phis);
-	DEL_ARR_F(env->copies);
+	ir_nodeset_destroy(&env->mem_phis);
 	obstack_free(&env->obst, NULL);
 	free(env);
 }
 
-/**
- * Returns a spill context. If the context did not exists, create one.
- *
- * @param sc        the set containing all spill contexts
- * @param to_spill  the node that should be spilled
- * @param ctx_irn   an user of the spilled node
+/*
+ *  ____  _                  ____      _                 _
+ * |  _ \| | __ _  ___ ___  |  _ \ ___| | ___   __ _  __| |___
+ * | |_) | |/ _` |/ __/ _ \ | |_) / _ \ |/ _ \ / _` |/ _` / __|
+ * |  __/| | (_| | (_|  __/ |  _ <  __/ | (_) | (_| | (_| \__ \
+ * |_|   |_|\__,_|\___\___| |_| \_\___|_|\___/ \__,_|\__,_|___/
  *
- * @return a spill context.
  */
-static spill_ctx_t *be_get_spill_ctx(set *sc, ir_node *to_spill, ir_node *ctx_irn) {
-	spill_ctx_t templ;
 
-	templ.spilled = to_spill;
-	templ.user    = ctx_irn;
-	templ.spill   = NULL;
+void be_add_remat(spill_env_t *env, ir_node *to_spill, ir_node *before,
+                  ir_node *rematted_node)
+{
+	spill_info_t *spill_info;
+	reloader_t *reloader;
+
+	spill_info = get_spillinfo(env, to_spill);
+
+	/* add the remat information */
+	reloader                = obstack_alloc(&env->obst, sizeof(reloader[0]));
+	reloader->next          = spill_info->reloaders;
+	reloader->reloader      = before;
+	reloader->rematted_node = rematted_node;
+	reloader->remat_cost_delta = 0; /* We will never have a cost win over a
+	                                   reload since we're not even allowed to
+	                                   create a reload */
+
+	spill_info->reloaders  = reloader;
 
-	return set_insert(sc, &templ, sizeof(templ), HASH_COMBINE(HASH_PTR(to_spill), HASH_PTR(ctx_irn)));
+	DBG((dbg, LEVEL_1, "creating spillinfo for %+F, will be rematerialized before %+F\n",
+		to_spill, before));
 }
 
-/**
- * Creates a spill.
- *
- * @param senv      the spill environment
- * @param irn       the node that should be spilled
- * @param ctx_irn   an user of the spilled node
- *
- * @return a be_Spill node
- */
-static ir_node *be_spill_irn(spill_env_t *senv, ir_node *irn, ir_node *ctx_irn) {
-	spill_ctx_t *ctx;
-	const be_main_env_t *env = senv->chordal_env->birg->main_env;
-	DBG((senv->dbg, LEVEL_1, "%+F in ctx %+F\n", irn, ctx_irn));
+void be_add_reload2(spill_env_t *env, ir_node *to_spill, ir_node *before, ir_node *can_spill_after,
+                   const arch_register_class_t *reload_cls, int allow_remat)
+{
+	spill_info_t *info;
+	reloader_t *rel;
 
-	// Has the value already been spilled?
-	ctx = be_get_spill_ctx(senv->spill_ctxs, irn, ctx_irn);
-	if(ctx->spill)
-		return ctx->spill;
+	info = get_spillinfo(env, to_spill);
 
-	/* Trying to spill an already spilled value, no need for a new spill
-	 * node then, we can simply connect to the same one for this reload
-	 */
-	if(be_is_Reload(irn)) {
-		return get_irn_n(irn, be_pos_Reload_mem);
+	if (is_Phi(to_spill)) {
+		int i, arity;
+
+		/* create spillinfos for the phi arguments */
+		for (i = 0, arity = get_irn_arity(to_spill); i < arity; ++i) {
+			ir_node *arg = get_irn_n(to_spill, i);
+			get_spillinfo(env, arg);
+		}
+
+#if 1
+		/* hackery... sometimes the morgan algo spilled the value of a phi,
+		 * the belady algo decides later to spill the whole phi, then sees the
+		 * spill node and adds a reload for that spill node, problem is the
+		 * reload gets attach to that same spill (and is totally unnecessary)
+		 */
+		if (info->old_spill != NULL &&
+			(before == info->old_spill || value_dominates(before, info->old_spill)))
+		{
+			printf("spilledphi hack was needed...\n");
+			before = sched_next(info->old_spill);
+		}
+#endif
 	}
 
-	ctx->spill = be_spill(env->arch_env, irn, ctx_irn);
+	assert(!is_Proj(before) && !be_is_Keep(before));
+
+	/* put reload into list */
+	rel                   = obstack_alloc(&env->obst, sizeof(rel[0]));
+	rel->next             = info->reloaders;
+	rel->reloader         = before;
+	rel->rematted_node    = NULL;
+	rel->can_spill_after  = can_spill_after;
+	rel->remat_cost_delta = allow_remat ? 0 : REMAT_COST_INFINITE;
 
-	return ctx->spill;
+	info->reloaders  = rel;
+	assert(info->reload_cls == NULL || info->reload_cls == reload_cls);
+	info->reload_cls = reload_cls;
+
+	DBG((dbg, LEVEL_1, "creating spillinfo for %+F, will be reloaded before %+F, may%s be rematerialized\n",
+		to_spill, before, allow_remat ? "" : " not"));
+}
+
+void be_add_reload(spill_env_t *senv, ir_node *to_spill, ir_node *before,
+                   const arch_register_class_t *reload_cls, int allow_remat)
+{
+	be_add_reload2(senv, to_spill, before, to_spill, reload_cls, allow_remat);
+
+}
+
+ir_node *be_get_end_of_block_insertion_point(const ir_node *block)
+{
+	ir_node *last = sched_last(block);
+
+	/* we might have projs and keepanys behind the jump... */
+	while(be_is_Keep(last)) {
+		last = sched_prev(last);
+		assert(!sched_is_end(last));
+	}
+
+	if(!is_cfop(last)) {
+		last = sched_next(last);
+		/* last node must be a cfop, only exception is the start block */
+		assert(last	== get_irg_start_block(get_irn_irg(block)));
+	}
+
+	/* add the reload before the (cond-)jump */
+	return last;
 }
 
 /**
- * Removes all copies introduced for phi-spills
+ * Returns the point at which you can insert a node that should be executed
+ * before block @p block when coming from pred @p pos.
  */
-static void remove_copies(spill_env_t *env) {
-	int i;
+static
+ir_node *get_block_insertion_point(ir_node *block, int pos)
+{
+	ir_node *predblock;
+
+	/* simply add the reload to the beginning of the block if we only have 1
+	 * predecessor. We don't need to check for phis as there can't be any in a
+	 * block with only 1 pred. */
+	if(get_Block_n_cfgpreds(block) == 1) {
+		assert(!is_Phi(sched_first(block)));
+		return sched_first(block);
+	}
+
+	/* We have to reload the value in pred-block */
+	predblock = get_Block_cfgpred_block(block, pos);
+	return be_get_end_of_block_insertion_point(predblock);
+}
 
-	for(i = 0; i < ARR_LEN(env->copies); ++i) {
-		ir_node *node = env->copies[i];
-		ir_node *src;
-		const ir_edge_t *edge, *ne;
+void be_add_reload_at_end(spill_env_t *env, ir_node *to_spill, const ir_node *block,
+                          const arch_register_class_t *reload_cls,
+                          int allow_remat)
+{
+	ir_node *before = be_get_end_of_block_insertion_point(block);
+	be_add_reload(env, to_spill, before, reload_cls, allow_remat);
+}
 
-		assert(be_is_Copy(node));
+void be_add_reload_on_edge(spill_env_t *env, ir_node *to_spill, ir_node *block,
+                           int pos,	const arch_register_class_t *reload_cls,
+                           int allow_remat)
+{
+	ir_node *before = get_block_insertion_point(block, pos);
+	be_add_reload(env, to_spill, before, reload_cls, allow_remat);
+}
 
-		src = be_get_Copy_op(node);
-		foreach_out_edge_safe(node, edge, ne) {
-			ir_node *user = get_edge_src_irn(edge);
-			int user_pos  = get_edge_src_pos(edge);
+void be_spill_phi(spill_env_t *env, ir_node *node)
+{
+	spill_info_t* spill;
+	int i, arity;
 
-			set_irn_n(user, user_pos, src);
-		}
+	assert(is_Phi(node));
+
+	ir_nodeset_insert(&env->mem_phis, node);
+
+	/* create spillinfos for the phi arguments */
+	spill = get_spillinfo(env, node);
+	for(i = 0, arity = get_irn_arity(node); i < arity; ++i) {
+		ir_node *arg = get_irn_n(node, i);
+		get_spillinfo(env, arg);
 	}
 
-	ARR_SETLEN(ir_node*, env->copies, 0);
+	/* if we had a spill for the phi value before, then remove this spill from
+	 * schedule, as we will remove it in the insert spill/reload phase
+	 */
+	if(spill->spill != NULL && !is_Phi(spill->spill)) {
+		assert(spill->old_spill == NULL);
+		spill->old_spill = spill->spill;
+		spill->spill = NULL;
+	}
 }
 
+/*
+ *   ____                _         ____        _ _ _
+ *  / ___|_ __ ___  __ _| |_ ___  / ___| _ __ (_) | |___
+ * | |   | '__/ _ \/ _` | __/ _ \ \___ \| '_ \| | | / __|
+ * | |___| | |  __/ (_| | ||  __/  ___) | |_) | | | \__ \
+ *  \____|_|  \___|\__,_|\__\___| |____/| .__/|_|_|_|___/
+ *                                      |_|
+ */
+
 /**
- * Searchs the schedule of a block backwards until we reach the first
- * use or def of a value or a phi.
- * Returns the node before this node (so that you can do sched_add_before)
+ * Schedules a node after an instruction. That is the place after all projs and
+ * phis that are scheduled after the instruction. This function also skips phi
+ * nodes at the beginning of a block
  */
-static ir_node *find_last_use_def(spill_env_t *env, ir_node *block, ir_node *value) {
-	ir_node *node, *last;
+static
+void sched_add_after_insn(ir_node *sched_after, ir_node *node)
+{
+	ir_node *next = sched_next(sched_after);
+	while(is_Proj(next) || is_Phi(next) || be_is_Keep(next)) {
+		next = sched_next(next);
+	}
+	assert(next != NULL);
 
-	last = NULL;
-	sched_foreach_reverse(block, node) {
-		int i, arity;
+	if(sched_is_end(next)) {
+		sched_add_after(sched_last(get_nodes_block(sched_after)), node);
+	} else {
+		sched_add_before(next, node);
+	}
+}
 
-		if(is_Phi(node)) {
-			return last;
-		}
-		if(value == node) {
-			return last;
-		}
-		for(i = 0, arity = get_irn_arity(node); i < arity; ++i) {
-			ir_node *arg = get_irn_n(node, i);
-			if(arg == value) {
-				return last;
-			}
-		}
-		last = node;
+/**
+ * Creates a spill.
+ *
+ * @param senv      the spill environment
+ * @param irn       the node that should be spilled
+ * @param ctx_irn   an user of the spilled node
+ *
+ * @return a be_Spill node
+ */
+static
+void spill_irn(spill_env_t *env, spill_info_t *spillinfo)
+{
+	optimization_state_t  opt;
+	ir_node              *to_spill = spillinfo->to_spill;
+
+	DBG((dbg, LEVEL_1, "spilling %+F ... ", to_spill));
+
+	/* Trying to spill an already spilled value, no need for a new spill
+	 * node then, we can simply connect to the same one for this reload
+	 *
+	 * Normally reloads get simply rematerialized instead of spilled again; this
+	 * can happen annyway when the reload is the pred of a phi to spill)
+	 */
+	if (be_is_Reload(to_spill)) {
+		spillinfo->spill = get_irn_n(to_spill, be_pos_Reload_mem);
+		DB((dbg, LEVEL_1, "skip reload, using existing spill %+F\n", spillinfo->spill));
+		return;
 	}
 
-	// simply return first node if no def or use found
-	return sched_first(block);
+	assert(!(arch_irn_is(env->arch_env, to_spill, dont_spill)
+				&& "Attempt to spill a node marked 'dont_spill'"));
+
+	/* some backends have virtual noreg/unknown nodes that are not scheduled */
+	if(!sched_is_scheduled(to_spill)) {
+		spillinfo->spill = new_NoMem();
+		return;
+	}
+
+
+	/*
+	 * We switch on optimizations here to get CSE. This is needed as the STA
+	 * backends has some extra spill phases and we want to make use of those
+	 * spills instead of creating new ones.
+	 */
+	save_optimization_state(&opt);
+	set_optimize(1);
+	spillinfo->spill = be_spill(env->arch_env, to_spill);
+	restore_optimization_state(&opt);
+	if (! sched_is_scheduled(spillinfo->spill)) {
+		DB((dbg, LEVEL_1, "add spill %+F after %+F\n", spillinfo->spill, to_spill));
+#ifdef FIRM_STATISTICS
+		env->spill_count++;
+#endif
+		sched_add_after_insn(to_spill, spillinfo->spill);
+	} else {
+		DB((dbg, LEVEL_1, "re-using spill %+F after %+F\n", spillinfo->spill, to_spill));
+	}
 }
 
+static
+void spill_node(spill_env_t *env, spill_info_t *spillinfo);
+
 /**
  * If the first usage of a Phi result would be out of memory
  * there is no sense in allocating a register for it.
@@ -240,68 +452,61 @@ static ir_node *find_last_use_def(spill_env_t *env, ir_node *block, ir_node *val
  * @param senv      the spill environment
  * @param phi       the Phi node that should be spilled
  * @param ctx_irn   an user of the spilled node
- *
- * @return a be_Spill node
  */
-static ir_node *spill_phi(spill_env_t *senv, ir_node *phi, ir_node *ctx_irn, set *already_visited_phis, bitset_t *bs) {
-	int         i;
+static
+void spill_phi(spill_env_t *env, spill_info_t *spillinfo)
+{
+	ir_node *phi = spillinfo->to_spill;
+	int i;
 	int arity = get_irn_arity(phi);
-	ir_graph    *irg      = senv->chordal_env->irg;
-	ir_node     *bl       = get_nodes_block(phi);
-	ir_node     **ins, *phi_spill;
-	phi_spill_assoc_t key;
-	spill_ctx_t *ctx;
+	ir_node     *block    = get_nodes_block(phi);
+	ir_node     **ins;
 
 	assert(is_Phi(phi));
-	DBG((senv->dbg, LEVEL_1, "%+F in ctx %+F\n", phi, ctx_irn));
 
+	DBG((dbg, LEVEL_1, "spilling Phi %+F:\n", phi));
 	/* build a new PhiM */
-	NEW_ARR_A(ir_node *, ins, arity);
-	for (i = 0; i < arity; ++i) {
-		ins[i] = new_r_Bad(irg);
+	ins = alloca(sizeof(ir_node*) * arity);
+	for(i = 0; i < arity; ++i) {
+		ins[i] = new_r_Unknown(env->irg, mode_M);
 	}
-	phi_spill = new_r_Phi(senv->chordal_env->irg, bl, arity, ins, mode_M);
-	key.phi   = phi;
-	key.spill = phi_spill;
-	set_insert(already_visited_phis, &key, sizeof(key), HASH_PTR(phi));
-	bitset_set(bs, get_irn_idx(phi));
-
-	/* search an existing spill for this context */
-	ctx = be_get_spill_ctx(senv->spill_ctxs, phi, ctx_irn);
-
-	/* if not found spill the phi */
-	if (! ctx->spill) {
-		/* collect all arguments of the phi */
-		for (i = 0; i < arity; ++i) {
-			ir_node *arg = get_irn_n(phi, i);
-			ir_node *sub_res;
-			phi_spill_assoc_t *entry;
-
-			if(is_Phi(arg) && pset_find_ptr(senv->mem_phis, arg)) {
-				// looping edge?
-				if(arg == phi) {
-					sub_res = phi_spill;
-				} else if (! bitset_is_set(bs, get_irn_idx(arg))) {
-					sub_res = spill_phi(senv, arg, ctx_irn, already_visited_phis, bs);
-				} else {
-					/* we already visited the argument phi: get it's spill */
-					key.phi   = arg;
-					key.spill = NULL;
-					entry     = set_find(already_visited_phis, &key, sizeof(key), HASH_PTR(arg));
-					assert(entry && "argument phi already visited, but no spill found?!?");
-					sub_res   = entry->spill;
-					assert(sub_res && "spill missing?!?");
-				}
-			} else {
-				sub_res = be_spill_irn(senv, arg, ctx_irn);
-			}
+	assert(!get_opt_cse());
+	spillinfo->spill = new_r_Phi(env->irg, block, arity, ins, mode_M);
+#ifdef FIRM_STATISTICS
+	env->spilled_phi_count++;
+#endif
 
-			set_irn_n(phi_spill, i, sub_res);
-		}
+	for(i = 0; i < arity; ++i) {
+		ir_node *arg = get_irn_n(phi, i);
+		spill_info_t *arg_info = get_spillinfo(env, arg);
 
-		ctx->spill = phi_spill;
+		spill_node(env, arg_info);
+
+		set_irn_n(spillinfo->spill, i, arg_info->spill);
+	}
+	DBG((dbg, LEVEL_1, "... done spilling Phi %+F, created PhiM %+F\n", phi, spillinfo->spill));
+
+	/* rewire reloads from old_spill to phi */
+	if (spillinfo->old_spill != NULL) {
+		const ir_edge_t *edge, *next;
+		ir_node *old_spill = spillinfo->old_spill;
+
+		DBG((dbg, LEVEL_1, "old spill found, rewiring reloads:\n"));
+
+		foreach_out_edge_safe(old_spill, edge, next) {
+			ir_node *reload = get_edge_src_irn(edge);
+			int     pos     = get_edge_src_pos(edge);
+
+			DBG((dbg, LEVEL_1, "\tset input %d of %+F to %+F\n", pos, reload, spillinfo->spill));
+
+			assert(be_is_Reload(reload) || is_Phi(reload));
+			set_irn_n(reload, pos, spillinfo->spill);
+		}
+		DBG((dbg, LEVEL_1, "\tset input of %+F to BAD\n", old_spill));
+		set_irn_n(old_spill, be_pos_Spill_val, new_Bad());
+		/* sched_remove(old_spill); */
+		spillinfo->old_spill = NULL;
 	}
-	return ctx->spill;
 }
 
 /**
@@ -309,110 +514,160 @@ static ir_node *spill_phi(spill_env_t *senv, ir_node *phi, ir_node *ctx_irn, set
  *
  * @param senv      the spill environment
  * @param to_spill  the node that should be spilled
- *
- * @return a be_Spill node
  */
-static ir_node *be_spill_node(spill_env_t *senv, ir_node *to_spill) {
-	ir_graph *irg = get_irn_irg(to_spill);
-	ir_node  *res;
-
-	if (pset_find_ptr(senv->mem_phis, to_spill)) {
-		set *already_visited_phis = new_set(cmp_phi_spill_assoc, 10);
-		bitset_t *bs = bitset_alloca(get_irg_last_idx(irg));
-		res = spill_phi(senv, to_spill, to_spill, already_visited_phis, bs);
-		del_set(already_visited_phis);
-	} else {
-		res = be_spill_irn(senv, to_spill, to_spill);
-	}
+static
+void spill_node(spill_env_t *env, spill_info_t *spillinfo)
+{
+	ir_node *to_spill;
 
-	return res;
-}
+	/* the node should be tagged for spilling already... */
+	if(spillinfo->spill != NULL)
+		return;
 
-#ifdef REMAT
+	to_spill = spillinfo->to_spill;
 
-#ifdef BUGGY_REMAT
+	if (is_Phi(to_spill) && ir_nodeset_contains(&env->mem_phis, to_spill)) {
+		spill_phi(env, spillinfo);
+	} else {
+		spill_irn(env, spillinfo);
+	}
+}
 
-/**
- * Check if a spilled node could be rematerialized.
+/*
+ *
+ *  ____                      _            _       _ _
+ * |  _ \ ___ _ __ ___   __ _| |_ ___ _ __(_) __ _| (_)_______
+ * | |_) / _ \ '_ ` _ \ / _` | __/ _ \ '__| |/ _` | | |_  / _ \
+ * |  _ <  __/ | | | | | (_| | ||  __/ |  | | (_| | | |/ /  __/
+ * |_| \_\___|_| |_| |_|\__,_|\__\___|_|  |_|\__,_|_|_/___\___|
  *
- * @param senv      the spill environment
- * @param spill     the Spill node
- * @param spilled   the node that was spilled
- * @param reloader  a irn that requires a reload
  */
-static int check_remat_conditions(spill_env_t *senv, ir_node *spill, ir_node *spilled, ir_node *reloader) {
-	int pos, max;
 
-	/* check for 'normal' spill and general remat condition */
-	if (!be_is_Spill(spill) || !arch_irn_is(senv->chordal_env->birg->main_env->arch_env, spilled, rematerializable))
-		return 0;
+/**
+ * Tests whether value @p arg is available before node @p reloader
+ * @returns 1 if value is available, 0 otherwise
+ */
+static
+int is_value_available(spill_env_t *env, const ir_node *arg, const ir_node *reloader)
+{
+	if(is_Unknown(arg) || arg == new_NoMem())
+		return 1;
 
-	/* check availability of original arguments */
-	if (is_Block(reloader)) {
+	if(be_is_Spill(arg))
+		return 1;
 
-		/* we want to remat at the end of a block.
-		 * thus all arguments must be alive at the end of the block
-		 */
-		for (pos=0, max=get_irn_arity(spilled); pos<max; ++pos) {
-			ir_node *arg = get_irn_n(spilled, pos);
-			if (!is_live_end(reloader, arg))
-				return 0;
-		}
+	if(arg == get_irg_frame(env->irg))
+		return 1;
 
-	} else {
+	/* hack for now (happens when command should be inserted at end of block) */
+	if(is_Block(reloader)) {
+		return 0;
+	}
 
-		/* we want to remat before the insn reloader
-		 * thus an arguments is alive if
-		 *   - it interferes with the reloaders result
-		 * or
-		 *   - or it is (last-) used by reloader itself
-		 */
-		for (pos=0, max=get_irn_arity(spilled); pos<max; ++pos) {
-			ir_node *arg = get_irn_n(spilled, pos);
-			int i, m;
+	/*
+	 * Ignore registers are always available
+	 */
+	if(arch_irn_is(env->arch_env, arg, ignore)) {
+		return 1;
+	}
 
-			if (values_interfere(reloader, arg))
-				goto is_alive;
+ 	/* the following test does not work while spilling,
+	 * because the liveness info is not adapted yet to the effects of the
+	 * additional spills/reloads.
+	 */
+#if 0
+	/* we want to remat before the insn reloader
+	 * thus an arguments is alive if
+	 *   - it interferes with the reloaders result
+	 *   - or it is (last-) used by reloader itself
+	 */
+	if (values_interfere(env->birg->lv, reloader, arg)) {
+		return 1;
+	}
 
-			for (i=0, m=get_irn_arity(reloader); i<m; ++i) {
-				ir_node *rel_arg = get_irn_n(reloader, i);
-				if (rel_arg == arg)
-					goto is_alive;
-			}
+	arity = get_irn_arity(reloader);
+	for (i = 0; i < arity; ++i) {
+		ir_node *rel_arg = get_irn_n(reloader, i);
+		if (rel_arg == arg)
+			return 1;
+	}
+#endif
 
-			/* arg is not alive before reloader */
-			return 0;
+ 	return 0;
+}
 
-is_alive:	;
+/**
+ * Checks whether the node can principally be rematerialized
+ */
+static
+int is_remat_node(spill_env_t *env, const ir_node *node)
+{
+	const arch_env_t *arch_env = env->arch_env;
 
-		}
+	assert(!be_is_Spill(node));
 
-	}
+	if(arch_irn_is(arch_env, node, rematerializable))
+		return 1;
 
-	return 1;
+	return 0;
 }
 
-#else /* BUGGY_REMAT */
-
 /**
- * A very simple rematerialization checker.
+ * Check if a node is rematerializable. This tests for the following conditions:
  *
- * @param senv      the spill environment
- * @param spill     the Spill node
- * @param spilled   the node that was spilled
- * @param reloader  a irn that requires a reload
+ * - The node itself is rematerializable
+ * - All arguments of the node are available or also rematerialisable
+ * - The costs for the rematerialisation operation is less or equal a limit
+ *
+ * Returns the costs needed for rematerialisation or something
+ * >= REMAT_COST_INFINITE if remat is not possible.
  */
-static int check_remat_conditions(spill_env_t *senv, ir_node *spill, ir_node *spilled, ir_node *reloader) {
-	const arch_env_t *aenv = senv->chordal_env->birg->main_env->arch_env;
+static
+int check_remat_conditions_costs(spill_env_t *env, const ir_node *spilled,
+                                 const ir_node *reloader, int parentcosts)
+{
+	int i, arity;
+	int argremats;
+	int costs = 0;
+
+	if(!is_remat_node(env, spilled))
+		return REMAT_COST_INFINITE;
+
+	if(be_is_Reload(spilled)) {
+		costs += 2;
+	} else {
+		costs += arch_get_op_estimated_cost(env->arch_env, spilled);
+	}
+	if(parentcosts + costs >= env->reload_cost + env->spill_cost) {
+		return REMAT_COST_INFINITE;
+	}
+	if(arch_irn_is(env->arch_env, spilled, modify_flags)) {
+		return REMAT_COST_INFINITE;
+	}
 
-	return get_irn_arity(spilled) == 0 &&
-		   be_is_Spill(spill) &&
-		   arch_irn_is(aenv, spilled, rematerializable);
-}
+	argremats = 0;
+	for(i = 0, arity = get_irn_arity(spilled); i < arity; ++i) {
+		ir_node *arg = get_irn_n(spilled, i);
 
-#endif /* BUGGY_REMAT */
+		if(is_value_available(env, arg, reloader))
+			continue;
 
-#endif /* REMAT */
+		/* we have to rematerialize the argument as well */
+		if(argremats >= 1) {
+			/* we only support rematerializing 1 argument at the moment,
+			 * so that we don't have to care about register pressure
+			 */
+			return REMAT_COST_INFINITE;
+		}
+		argremats++;
+
+		costs += check_remat_conditions_costs(env, arg, reloader, parentcosts + costs);
+		if(parentcosts + costs >= env->reload_cost + env->spill_cost)
+			return REMAT_COST_INFINITE;
+	}
+
+	return costs;
+}
 
 /**
  * Re-materialize a node.
@@ -421,434 +676,257 @@ static int check_remat_conditions(spill_env_t *senv, ir_node *spill, ir_node *sp
  * @param spilled   the node that was spilled
  * @param reloader  a irn that requires a reload
  */
-static ir_node *do_remat(spill_env_t *senv, ir_node *spilled, ir_node *reloader) {
+static
+ir_node *do_remat(spill_env_t *env, ir_node *spilled, ir_node *reloader)
+{
+	int i, arity;
 	ir_node *res;
-	ir_node *bl = (is_Block(reloader)) ? reloader : get_nodes_block(reloader);
-
-	/* recompute the value */
-	res = new_ir_node(get_irn_dbg_info(spilled), senv->chordal_env->irg, bl,
-		get_irn_op(spilled),
-		get_irn_mode(spilled),
-		get_irn_arity(spilled),
-		get_irn_in(spilled) + 1);
-	copy_node_attr(spilled, res);
-
-	DBG((senv->dbg, LEVEL_1, "Insert remat %+F before reloader %+F\n", res, reloader));
+	ir_node *bl;
+	ir_node **ins;
 
-	/* insert in schedule */
-	if (is_Block(reloader)) {
-		ir_node *insert = sched_skip(reloader, 0, sched_skip_cf_predicator, (void *) senv->chordal_env->birg->main_env->arch_env);
-		sched_add_after(insert, res);
+	if(is_Block(reloader)) {
+		bl = reloader;
 	} else {
-		sched_add_before(reloader, res);
+		bl = get_nodes_block(reloader);
 	}
 
-	return res;
-}
-
-void be_spill_phi(spill_env_t *env, ir_node *node) {
-	assert(is_Phi(node));
-
-	pset_insert_ptr(env->mem_phis, node);
-}
-
-void be_insert_spills_reloads(spill_env_t *env) {
-	const arch_env_t *arch_env = env->chordal_env->birg->main_env->arch_env;
-	ir_node *node;
-	spill_info_t *si;
-
-	DBG((env->dbg, LEVEL_1, "Reloads for mem-phis:\n"));
-	foreach_pset(env->mem_phis, node) {
-		const ir_edge_t *e;
-		int i, arity;
-
-		assert(is_Phi(node));
-
-		/* We have to place copy nodes in the predecessor blocks to temporarily
-		 * produce new values that get separate spill slots
-		 */
-		for(i = 0, arity = get_irn_arity(node); i < arity; ++i) {
-			ir_node *pred_block, *arg, *copy, *insert_point;
-
-			/* Don't do anything for looping edges (there's no need
-			 * and placing copies here breaks stuff as it suddenly
-			 * generates new living values through the whole loop)
-			 */
-			arg = get_irn_n(node, i);
-			if(arg == node)
-				continue;
-
-			pred_block = get_Block_cfgpred_block(get_nodes_block(node), i);
-			copy = be_new_Copy(env->cls, get_irn_irg(arg), pred_block, arg);
-
-			ARR_APP1(ir_node*, env->copies, copy);
-			insert_point = find_last_use_def(env, pred_block, arg);
-			sched_add_before(insert_point, copy);
-
-			set_irn_n(node, i, copy);
-		}
-
-		/* Add reloads for mem_phis */
-		/* BETTER: These reloads (1) should only be inserted, if they are really needed */
-		DBG((env->dbg, LEVEL_1, " Mem-phi %+F\n", node));
-		foreach_out_edge(node, e) {
-			ir_node *user = e->src;
-			if (is_Phi(user) && !pset_find_ptr(env->mem_phis, user)) {
-				ir_node *use_bl = get_nodes_block(user);
-				DBG((env->dbg, LEVEL_1, " non-mem-phi user %+F\n", user));
-				be_add_reload_on_edge(env, node, use_bl, e->pos); /* (1) */
-			}
+	ins = alloca(get_irn_arity(spilled) * sizeof(ins[0]));
+	for(i = 0, arity = get_irn_arity(spilled); i < arity; ++i) {
+		ir_node *arg = get_irn_n(spilled, i);
+
+		if(is_value_available(env, arg, reloader)) {
+			ins[i] = arg;
+		} else {
+			ins[i] = do_remat(env, arg, reloader);
+#ifdef FIRM_STATISTICS
+			/* don't count the recursive call as remat */
+			env->remat_count--;
+#endif
 		}
 	}
 
-	/* process each spilled node */
-	DBG((env->dbg, LEVEL_1, "Insert spills and reloads:\n"));
-	for(si = set_first(env->spills); si; si = set_next(env->spills)) {
-		reloader_t *rld;
-		ir_mode *mode = get_irn_mode(si->spilled_node);
-		pset *values = pset_new_ptr(16);
-
-		/* go through all reloads for this spill */
-		for(rld = si->reloaders; rld; rld = rld->next) {
-			ir_node *new_val;
+	/* create a copy of the node */
+	res = new_ir_node(get_irn_dbg_info(spilled), env->irg, bl,
+	                  get_irn_op(spilled), get_irn_mode(spilled),
+	                  get_irn_arity(spilled), ins);
+	copy_node_attr(spilled, res);
+	new_backedge_info(res);
 
-			/* the spill for this reloader */
-			ir_node *spill   = be_spill_node(env, si->spilled_node);
+	DBG((dbg, LEVEL_1, "Insert remat %+F of %+F before reloader %+F\n", res, spilled, reloader));
 
-#ifdef REMAT
-			if (check_remat_conditions(env, spill, si->spilled_node, rld->reloader)) {
-				new_val = do_remat(env, si->spilled_node, rld->reloader);
-			} else
+	if (! is_Proj(res)) {
+		/* insert in schedule */
+		sched_reset(res);
+		sched_add_before(reloader, res);
+#ifdef FIRM_STATISTICS
+		env->remat_count++;
 #endif
-				/* do a reload */
-				new_val = be_reload(arch_env, env->cls, rld->reloader, mode, spill);
-
-			DBG((env->dbg, LEVEL_1, " %+F of %+F before %+F\n", new_val, si->spilled_node, rld->reloader));
-			pset_insert_ptr(values, new_val);
-		}
-
-		/* introduce copies, rewire the uses */
-		assert(pset_count(values) > 0 && "???");
-		pset_insert_ptr(values, si->spilled_node);
-		be_ssa_constr_set_ignore(env->chordal_env->dom_front, values, env->mem_phis);
-
-		del_pset(values);
 	}
 
-	remove_copies(env);
-
-	// reloads are placed now, but we might reuse the spill environment for further spilling decisions
-	del_set(env->spills);
-	env->spills = new_set(cmp_spillinfo, 1024);
+	return res;
 }
 
-void be_add_reload(spill_env_t *env, ir_node *to_spill, ir_node *before) {
-	spill_info_t templ, *res;
-	reloader_t *rel;
-
-	assert(sched_is_scheduled(before));
-	assert(arch_irn_consider_in_reg_alloc(env->chordal_env->birg->main_env->arch_env, env->cls, to_spill));
-
-	templ.spilled_node = to_spill;
-	templ.reloaders    = NULL;
-	res = set_insert(env->spills, &templ, sizeof(templ), HASH_PTR(to_spill));
+double be_get_spill_costs(spill_env_t *env, ir_node *to_spill, ir_node *after)
+{
+	ir_node *block = get_nodes_block(after);
+	double   freq  = get_block_execfreq(env->exec_freq, block);
+	(void) to_spill;
 
-	rel           = obstack_alloc(&env->obst, sizeof(rel[0]));
-	rel->reloader = before;
-	rel->next     = res->reloaders;
-	res->reloaders = rel;
+	return env->spill_cost * freq;
 }
 
-void be_add_reload_on_edge(spill_env_t *env, ir_node *to_spill, ir_node *block, int pos) {
-	ir_node *predblock, *last;
+double be_get_reload_costs(spill_env_t *env, ir_node *to_spill, ir_node *before)
+{
+	ir_node      *block = get_nodes_block(before);
+	double        freq  = get_block_execfreq(env->exec_freq, block);
 
-	/* simply add the reload to the beginning of the block if we only have 1 predecessor
-	 * (we don't need to check for phis as there can't be any in a block with only 1 pred)
-	 */
-	if(get_Block_n_cfgpreds(block) == 1) {
-		assert(!is_Phi(sched_first(block)));
-		be_add_reload(env, to_spill, sched_first(block));
-		return;
+	if(be_do_remats) {
+		/* is the node rematerializable? */
+		int costs = check_remat_conditions_costs(env, to_spill, before, 0);
+		if(costs < env->reload_cost)
+			return costs * freq;
 	}
 
-	// We have to reload the value in pred-block
-	predblock = get_Block_cfgpred_block(block, pos);
-	last = sched_last(predblock);
-	// there should be exactly 1 jump at the end of the block
-	assert(is_cfop(last));
-
-	// add the reload before the (cond-)jump
-	be_add_reload(env, to_spill, last);
+	return env->reload_cost * freq;
 }
 
-/****************************************
-
-	SPILL SLOT MANAGEMENT AND OPTS
-
-****************************************/
+int be_is_rematerializable(spill_env_t *env, const ir_node *to_remat, const ir_node *before)
+{
+	return check_remat_conditions_costs(env, to_remat, before, 0) < REMAT_COST_INFINITE;
+}
 
-typedef struct _spill_slot_t {
-	unsigned size;
-	unsigned align;
-	pset *members;
-	ir_mode *largest_mode;	/* the mode of all members with largest size */
-} spill_slot_t;
+double be_get_reload_costs_on_edge(spill_env_t *env, ir_node *to_spill,
+                                ir_node *block, int pos)
+{
+	ir_node *before = get_block_insertion_point(block, pos);
+	return be_get_reload_costs(env, to_spill, before);
+}
 
-typedef struct _ss_env_t {
-	struct obstack ob;
-	be_chordal_env_t *cenv;
-	pmap *slots;		/* maps spill_contexts to spill_slots */
-	pmap *types;    /* maps modes to types */
-	DEBUG_ONLY(firm_dbg_module_t *dbg;)
-} ss_env_t;
+/*
+ *  ___                     _     ____      _                 _
+ * |_ _|_ __  ___  ___ _ __| |_  |  _ \ ___| | ___   __ _  __| |___
+ *  | || '_ \/ __|/ _ \ '__| __| | |_) / _ \ |/ _ \ / _` |/ _` / __|
+ *  | || | | \__ \  __/ |  | |_  |  _ <  __/ | (_) | (_| | (_| \__ \
+ * |___|_| |_|___/\___|_|   \__| |_| \_\___|_|\___/ \__,_|\__,_|___/
+ *
+ */
 
+void be_insert_spills_reloads(spill_env_t *env)
+{
+	const arch_env_t      *arch_env  = env->arch_env;
+	const ir_exec_freq    *exec_freq = env->exec_freq;
+	spill_info_t          *si;
+	ir_nodeset_iterator_t  iter;
+	ir_node               *node;
+
+	/* create all phi-ms first, this is needed so, that phis, hanging on
+	   spilled phis work correctly */
+	foreach_ir_nodeset(&env->mem_phis, node, iter) {
+		spill_info_t *info = get_spillinfo(env, node);
+		spill_node(env, info);
+	}
 
-/**
- * Walker: compute the spill slots
- */
-static void compute_spill_slots_walker(ir_node *spill, void *env) {
-	ss_env_t *ssenv = env;
-	ir_node *ctx;
-	pmap_entry *entry;
-	spill_slot_t *ss;
+	/* process each spilled node */
+	for (si = set_first(env->spills); si; si = set_next(env->spills)) {
+		reloader_t *rld;
+		ir_node  *to_spill        = si->to_spill;
+		ir_mode  *mode            = get_irn_mode(to_spill);
+		ir_node **copies          = NEW_ARR_F(ir_node*, 0);
+		double    all_remat_costs = 0; /** costs when we would remat all nodes */
+		int       force_remat     = 0;
+
+		DBG((dbg, LEVEL_1, "\nhandling all reloaders of %+F:\n", to_spill));
+
+		/* determine possibility of rematerialisations */
+		if(be_do_remats) {
+			for (rld = si->reloaders; rld != NULL; rld = rld->next) {
+				double   freq;
+				int      remat_cost;
+				int      remat_cost_delta;
+				ir_node *block;
+				ir_node *reloader = rld->reloader;
+
+				if(rld->rematted_node != NULL) {
+					DBG((dbg, LEVEL_2, "\tforced remat %+F before %+F\n",
+					     rld->rematted_node, reloader));
+					continue;
+				}
+				if(rld->remat_cost_delta >= REMAT_COST_INFINITE) {
+					DBG((dbg, LEVEL_2, "\treload before %+F is forbidden\n",
+					     reloader));
+					all_remat_costs = REMAT_COST_INFINITE;
+					continue;
+				}
 
-	if (!be_is_Spill(spill))
-		return;
+				remat_cost  = check_remat_conditions_costs(env, to_spill,
+				                                           reloader, 0);
+				if(remat_cost >= REMAT_COST_INFINITE) {
+					DBG((dbg, LEVEL_2, "\tremat before %+F not possible\n",
+					     reloader));
+					rld->remat_cost_delta = REMAT_COST_INFINITE;
+					all_remat_costs       = REMAT_COST_INFINITE;
+					continue;
+				}
 
-	/* check, if this spill is for a context already known */
-	ctx = be_get_Spill_context(spill);
-	entry = pmap_find(ssenv->slots, ctx);
-
-	if (!entry) {
-		struct _arch_env_t *arch_env     = ssenv->cenv->birg->main_env->arch_env;
-		const arch_register_class_t *cls = arch_get_irn_reg_class(arch_env, spill, be_pos_Spill_val);
-		ir_mode *largest_mode            = arch_register_class_mode(cls);
-
-		/* this is a new spill context */
-		ss = obstack_alloc(&ssenv->ob, sizeof(*ss));
-		ss->members      = pset_new_ptr(8);
-		ss->largest_mode = largest_mode;
-		ss->size         = get_mode_size_bytes(ss->largest_mode);
-		ss->align        = arch_isa_get_reg_class_alignment(arch_env->isa, cls);
-		pmap_insert(ssenv->slots, ctx, ss);
-	} else {
-		/* values with the same spill_ctx must go into the same spill slot */
-		ss = entry->value;
+				remat_cost_delta      = remat_cost - env->reload_cost;
+				rld->remat_cost_delta = remat_cost_delta;
+				block                 = is_Block(reloader) ? reloader : get_nodes_block(reloader);
+				freq                  = get_block_execfreq(exec_freq, block);
+				all_remat_costs      += remat_cost_delta * freq;
+				DBG((dbg, LEVEL_2, "\tremat costs delta before %+F: "
+				     "%d (rel %f)\n", reloader, remat_cost_delta,
+				     remat_cost_delta * freq));
+			}
+			if(all_remat_costs < REMAT_COST_INFINITE) {
+				ir_node *block = get_nodes_block(to_spill);
+				double   freq  = get_block_execfreq(exec_freq, block);
+				/* we don't need the costs for the spill if we can remat
+				   all reloaders */
+				all_remat_costs -= env->spill_cost * freq;
+
+				DBG((dbg, LEVEL_2, "\tspill costs %d (rel %f)\n",
+				     env->spill_cost, env->spill_cost * freq));
+			}
 
-#ifndef NDEBUG
-		/* ugly mega assert :-) */
-		{
-			ir_node *irn;
-			struct _arch_env_t *arch_env     = ssenv->cenv->birg->main_env->arch_env;
-			const arch_register_class_t *cls = arch_get_irn_reg_class(arch_env, spill, be_pos_Spill_val);
-			int size = get_mode_size_bytes(arch_register_class_mode(cls));
-			assert((int) ss->size == size && "Different sizes for the same spill slot are not allowed.");
-			for (irn = pset_first(ss->members); irn; irn = pset_next(ss->members)) {
-				/* use values_interfere here, because it uses the dominance check,
-					 which does work for values in memory */
-				assert(!values_interfere(spill, irn) && "Spills for the same spill slot must not interfere!");
+			if(all_remat_costs < 0) {
+				DBG((dbg, LEVEL_1, "\nforcing remats of all reloaders (%f)\n",
+				     all_remat_costs));
+				force_remat = 1;
 			}
 		}
-#endif /* NDEBUG */
-	}
 
-	pset_insert_ptr(ss->members, spill);
-}
-
-/**
- * qsort compare function, sort spill slots by size.
- */
-static int ss_sorter(const void *v1, const void *v2) {
-	const spill_slot_t **ss1 = (const spill_slot_t **)v1;
-	const spill_slot_t **ss2 = (const spill_slot_t **)v2;
-	return ((int) (*ss2)->size) - ((int) (*ss1)->size);
-}
+		/* go through all reloads for this spill */
+		for (rld = si->reloaders; rld != NULL; rld = rld->next) {
+			ir_node *copy; /* a reload is a "copy" of the original value */
+
+			if (rld->rematted_node != NULL) {
+				copy = rld->rematted_node;
+				sched_add_before(rld->reloader, copy);
+			} else if (be_do_remats &&
+					(force_remat || rld->remat_cost_delta < 0)) {
+				copy = do_remat(env, to_spill, rld->reloader);
+			} else {
+				/* make sure we have a spill */
+				if (si->spill == NULL) {
+					spill_node(env, si);
+				}
 
+				/* create a reload */
+				copy = be_reload(arch_env, si->reload_cls, rld->reloader, mode,
+				                 si->spill);
+#ifdef FIRM_STATISTICS
+				env->reload_count++;
+#endif
+			}
 
-/**
- * This function should optimize the spill slots.
- *  - Coalescing of multiple slots
- *  - Ordering the slots
- *
- * Input slots are in @p ssenv->slots
- * @p size The count of initial spill slots in @p ssenv->slots
- *         This also is the size of the preallocated array @p ass
- *
- * @return An array of spill slots @p ass in specific order
- **/
-static void optimize_slots(ss_env_t *ssenv, int size, spill_slot_t *ass[]) {
-	int i, o, used_slots;
-	pmap_entry *entr;
-
-	i=0;
-	pmap_foreach(ssenv->slots, entr)
-		ass[i++] = entr->value;
-
-	/* Sort the array to minimize fragmentation and cache footprint.
-	   Large slots come first */
-	qsort(ass, size, sizeof(ass[0]), ss_sorter);
-
-	/* For each spill slot:
-		- assign a new offset to this slot
-	    - xor find another slot to coalesce with */
-	used_slots = 0;
-	for (i=0; i<size; ++i) { /* for each spill slot */
-		ir_node *n1;
-		int tgt_slot = -1;
-
-		DBG((ssenv->dbg, LEVEL_1, "Spill slot %d members:\n", i));
-		for(n1 = pset_first(ass[i]->members); n1; n1 = pset_next(ass[i]->members))
-			DBG((ssenv->dbg, LEVEL_1, "  %+F\n", n1));
-
-
-		for (o=0; o < used_slots && tgt_slot == -1; ++o) { /* for each offset-assigned spill slot */
-			/* check inter-slot-pairs for interference */
-			ir_node *n2;
-			for(n1 = pset_first(ass[i]->members); n1; n1 = pset_next(ass[i]->members))
-				for(n2 = pset_first(ass[o]->members); n2; n2 = pset_next(ass[o]->members))
-					if(values_interfere(n1, n2)) {
-						pset_break(ass[i]->members);
-						pset_break(ass[o]->members);
-						DBG((ssenv->dbg, LEVEL_1, "    Interf %+F -- %+F\n", n1, n2));
-						goto interf_detected;
-					}
-
-			/* if we are here, there is no interference between ass[i] and ass[o] */
-			tgt_slot = o;
-
-interf_detected: /*nothing*/ ;
+			DBG((dbg, LEVEL_1, " %+F of %+F before %+F\n",
+			     copy, to_spill, rld->reloader));
+			ARR_APP1(ir_node*, copies, copy);
 		}
 
-		/* now the members of ass[i] join the members of ass[tgt_slot] */
-
-		/* do we need a new slot? */
-		if (tgt_slot == -1) {
-			tgt_slot = used_slots;
-			used_slots++;
-
-			/* init slot */
-			if (tgt_slot != i) {
-				ass[tgt_slot]->size = ass[i]->size;
-				del_pset(ass[tgt_slot]->members);
-				ass[tgt_slot]->members = pset_new_ptr(8);
+		/* if we had any reloads or remats, then we need to reconstruct the
+		 * SSA form for the spilled value */
+		if (ARR_LEN(copies) > 0) {
+			be_ssa_construction_env_t senv;
+			/* be_lv_t *lv = be_get_birg_liveness(env->birg); */
+
+			be_ssa_construction_init(&senv, env->birg);
+			be_ssa_construction_add_copy(&senv, to_spill);
+			be_ssa_construction_add_copies(&senv, copies, ARR_LEN(copies));
+			be_ssa_construction_fix_users(&senv, to_spill);
+
+#if 0
+			/* no need to enable this as long as we invalidate liveness
+			   after this function... */
+			be_ssa_construction_update_liveness_phis(&senv);
+			be_liveness_update(to_spill);
+			len = ARR_LEN(copies);
+			for(i = 0; i < len; ++i) {
+				be_liveness_update(lv, copies[i]);
 			}
+#endif
+			be_ssa_construction_destroy(&senv);
 		}
 
-		/* copy the members to the target pset */
-		/* NOTE: If src and tgt pset are the same, inserting while iterating is not allowed */
-		if (tgt_slot != i)
-			for(n1 = pset_first(ass[i]->members); n1; n1 = pset_next(ass[i]->members))
-					pset_insert_ptr(ass[tgt_slot]->members, n1);
+		DEL_ARR_F(copies);
+		si->reloaders = NULL;
 	}
-}
 
-#define ALIGN_SPILL_AREA 16
-#define pset_foreach(pset, elm)  for(elm=pset_first(pset); elm; elm=pset_next(pset))
+	stat_ev_dbl("spill_spills", env->spill_count);
+	stat_ev_dbl("spill_reloads", env->reload_count);
+	stat_ev_dbl("spill_remats", env->remat_count);
+	stat_ev_dbl("spill_spilled_phis", env->spilled_phi_count);
 
-/**
- * Returns a spill type for a mode. Keep them in a map to reduce
- * the number of types.
- *
- * @param types  a map containing all created types
- * @param ss     the spill slot
- *
- * Note that type types should are identical for every mode.
- * This rule might break if two different register classes return the same
- * mode but different alignments.
- */
-static ir_type *get_spill_type(pmap *types, spill_slot_t *ss) {
-	pmap_entry *e = pmap_find(types, ss->largest_mode);
-	ir_type *res;
-
-	if (! e) {
-		char buf[64];
-		snprintf(buf, sizeof(buf), "spill_slot_type_%s", get_mode_name(ss->largest_mode));
-		res = new_type_primitive(new_id_from_str(buf), ss->largest_mode);
-		set_type_alignment_bytes(res, ss->align);
-		pmap_insert(types, ss->largest_mode, res);
-	} else {
-		res = e->value;
-		assert(get_type_alignment_bytes(res) == (int)ss->align);
-	}
+	/* Matze: In theory be_ssa_construction should take care of the liveness...
+	 * try to disable this again in the future */
+	be_liveness_invalidate(env->birg->lv);
 
-	return res;
+	be_remove_dead_nodes_from_schedule(env->birg);
 }
 
-/**
- * Create spill slot entities on the frame type.
- *
- * @param ssenv   the spill environment
- * @param n       number of spill slots
- * @param ss      array of spill slots
- */
-static void assign_entities(ss_env_t *ssenv, int n_slots, spill_slot_t *ss[]) {
-	int i, offset, frame_align;
-	ir_type *frame = get_irg_frame_type(ssenv->cenv->irg);
-
-	/* aligning by increasing frame size */
-	offset = get_type_size_bits(frame) / 8;
-	offset = round_up2(offset, ALIGN_SPILL_AREA);
-	set_type_size_bytes(frame, -1);
-
-	/* create entities and assign offsets according to size and alignment*/
-	for (i = 0; i < n_slots; ++i) {
-		char buf[64];
-		ident *name;
-		entity *spill_ent;
-		ir_node *irn;
-
-		/* build entity */
-		snprintf(buf, sizeof(buf), "spill_slot_%d", i);
-		name = new_id_from_str(buf);
-
-		spill_ent = new_entity(frame, name, get_spill_type(ssenv->types, ss[i]));
-
-		/* align */
-		offset = round_up2(offset, ss[i]->align);
-		/* set */
-		set_entity_offset_bytes(spill_ent, offset);
-		/* next possible offset */
-		offset += round_up2(ss[i]->size, ss[i]->align);
-
-		pset_foreach(ss[i]->members, irn)
-			be_set_Spill_entity(irn, spill_ent);
-	}
-
-
-	/* set final size of stack frame */
-	frame_align = get_type_alignment_bytes(frame);
-	set_type_size_bytes(frame, round_up2(offset, frame_align));
+void be_init_spill(void)
+{
+	FIRM_DBG_REGISTER(dbg, "firm.be.spill");
 }
 
-void be_compute_spill_offsets(be_chordal_env_t *cenv) {
-	ss_env_t ssenv;
-	spill_slot_t **ss;
-	int ss_size;
-	pmap_entry *pme;
-
-	obstack_init(&ssenv.ob);
-	ssenv.cenv  = cenv;
-	ssenv.slots = pmap_create();
-	ssenv.types = pmap_create();
-	FIRM_DBG_REGISTER(ssenv.dbg, "ir.be.spillslots");
-
-	/* Get initial spill slots */
-	irg_walk_graph(cenv->irg, NULL, compute_spill_slots_walker, &ssenv);
-
-	/* Build an empty array for optimized spill slots */
-	ss_size = pmap_count(ssenv.slots);
-	ss = obstack_alloc(&ssenv.ob, ss_size * sizeof(*ss));
-	optimize_slots(&ssenv, ss_size, ss);
-
-	/* Integrate slots into the stack frame entity */
-	assign_entities(&ssenv, ss_size, ss);
-
-	/* Clean up */
-	pmap_foreach(ssenv.slots, pme)
-	del_pset(((spill_slot_t *)pme->value)->members);
-	pmap_destroy(ssenv.slots);
-	pmap_destroy(ssenv.types);
-	obstack_free(&ssenv.ob, NULL);
-
-	be_copy_entities_to_reloads(cenv->irg);
-}
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spill);