X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbespillbelady.c;h=948278f6c42a5a03d2781845136a6fc4442b0f52;hb=7fea0e8ae1bf276ccce6e1c511d5b78ca098a78b;hp=ed71c5eb307167dd3b963641907398a4f4180fd6;hpb=725146f122809f3a449e66bb1a38c6675f367557;p=libfirm

diff --git a/ir/be/bespillbelady.c b/ir/be/bespillbelady.c
index ed71c5eb3..948278f6c 100644
--- a/ir/be/bespillbelady.c
+++ b/ir/be/bespillbelady.c
@@ -1,247 +1,302 @@
+/*
+ * 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
- * Date:		20.09.2005
- * Copyright:   (c) Universitaet Karlsruhe
- * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
+ * @file
+ * @brief       Beladys spillalgorithm.
+ * @author      Daniel Grund, Matthias Braun
+ * @date        20.09.2005
+ * @version     $Id$
  */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
 
-#include <alloca.h>
 #include "obst.h"
-#include "set.h"
-#include "pset.h"
+#include "irprintf_t.h"
 #include "irgraph.h"
 #include "irnode.h"
 #include "irmode.h"
 #include "irgwalk.h"
+#include "irloop.h"
 #include "iredges_t.h"
 #include "ircons_t.h"
+#include "irprintf.h"
+#include "irnodeset.h"
+#include "xmalloc.h"
+#include "pdeq.h"
 
 #include "beutil.h"
-#include "bearch.h"
-#include "bespillbelady.h"
-#include "beuses_t.h"
+#include "bearch_t.h"
+#include "beuses.h"
 #include "besched_t.h"
 #include "beirgmod.h"
 #include "belive_t.h"
 #include "benode_t.h"
+#include "bechordal_t.h"
+#include "bespilloptions.h"
+#include "beloopana.h"
+#include "beirg_t.h"
+#include "bespill.h"
+#include "bemodule.h"
+
+#define DBG_SPILL     1
+#define DBG_WSETS     2
+#define DBG_FIX       4
+#define DBG_DECIDE    8
+#define DBG_START    16
+#define DBG_SLOTS    32
+#define DBG_TRACE    64
+#define DBG_WORKSET 128
+DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
+
+/* factor to weight the different costs of reloading/rematerializing a node
+   (see bespill.h be_get_reload_costs_no_weight) */
+#define RELOAD_COST_FACTOR   10
+
+typedef enum {
+	value_not_reloaded,       /* the value has not been reloaded */
+	value_partially_reloaded, /* the value has been reloaded on some paths */
+	value_reloaded            /* the value has been reloaded on all paths */
+} reloaded_state_t;
 
-#define DBG_SPILL   1
-#define DBG_WSETS   2
-#define DBG_FIX     4
-#define DBG_DECIDE  8
-#define DBG_START  16
-#define DBG_TRACE  64
-#define DEBUG_LVL SET_LEVEL_0 //(DBG_START | DBG_DECIDE | DBG_WSETS | DBG_FIX | DBG_SPILL)
-static firm_dbg_module_t *dbg = NULL;
-
-#define MIN(a,b) (((a)<(b))?(a):(b))
-#define SINGLE_START_PROJS
-
-typedef struct _workset_t workset_t;
-
-typedef struct _belady_env_t {
-	struct obstack ob;
-	const be_node_factory_t *factory;
-	const arch_env_t *arch;
-	const arch_register_class_t *cls;
-	int n_regs;			/** number of regs in this reg-class */
-
-	workset_t *ws;		/**< the main workset used while processing a block. ob-allocated */
-	be_uses_t *uses;	/**< env for the next-use magic */
-	ir_node *instr;		/**< current instruction */
-	unsigned instr_nr;	/**< current instruction number (relative to block start) */
-	pset *used;			/**< holds the values used (so far) in the current BB */
-
-	spill_env_t *senv;	/* see bespill.h */
-	pset *reloads;		/**< all reload nodes placed */
-} belady_env_t;
-
-struct _workset_t {
-	belady_env_t *bel;
-	int i;				/**< used for iteration */
-	int len;			/**< current length */
-	loc_t vals[1];		/**< inlined array of the values/distances in this working set */
-};
-
-typedef struct _block_info_t {
-	workset_t *ws_start, *ws_end;
-} block_info_t;
+/**
+ * An association between a node and a point in time.
+ */
+typedef struct loc_t {
+	ir_node          *node;
+	unsigned          time;     /**< A use time (see beuses.h). */
+	reloaded_state_t  reloaded; /**< the value is a reloaded value */
+} loc_t;
+
+typedef struct _workset_t {
+	int   len;          /**< current length */
+	loc_t vals[0];      /**< inlined array of the values/distances in this working set */
+} workset_t;
+
+static struct obstack               obst;
+static const arch_env_t            *arch_env;
+static const arch_register_class_t *cls;
+static const be_lv_t               *lv;
+static be_loopana_t                *loop_ana;
+static int                          n_regs;
+static workset_t                   *ws;     /**< the main workset used while
+	                                             processing a block. */
+static be_uses_t                   *uses;   /**< env for the next-use magic */
+static ir_node                     *instr;  /**< current instruction */
+static unsigned                     instr_nr; /**< current instruction number
+	                                               (relative to block start) */
+static ir_nodeset_t                 used;
+static spill_env_t                 *senv;   /**< see bespill.h */
+static pdeq                        *worklist;
+
+static int loc_compare(const void *a, const void *b)
+{
+	const loc_t *p = a;
+	const loc_t *q = b;
+	return p->time - q->time;
+}
+
+void workset_print(const workset_t *w)
+{
+	int i;
+
+	for(i = 0; i < w->len; ++i) {
+		ir_fprintf(stderr, "%+F %d\n", w->vals[i].node, w->vals[i].time);
+	}
+}
 
 /**
  * Alloc a new workset on obstack @p ob with maximum size @p max
  */
-static INLINE workset_t *new_workset(struct obstack *ob, belady_env_t *bel) {
+static workset_t *new_workset(void)
+{
 	workset_t *res;
-	size_t size = sizeof(*res) + (bel->n_regs-1)*sizeof(res->vals[0]);
-	res = obstack_alloc(ob, size);
+	size_t     size = sizeof(*res) + n_regs * sizeof(res->vals[0]);
+
+	res  = obstack_alloc(&obst, size);
 	memset(res, 0, size);
-	res->bel = bel;
 	return res;
 }
 
-static INLINE workset_t *workset_clone(struct obstack *ob, workset_t *ws) {
+/**
+ * Alloc a new instance on obstack and make it equal to @param workset
+ */
+static workset_t *workset_clone(workset_t *workset)
+{
 	workset_t *res;
-	size_t size = sizeof(*res) + (ws->bel->n_regs-1)*sizeof(res->vals[0]);
-	res = obstack_alloc(ob, size);
-	memcpy(res, ws, size);
+	size_t size = sizeof(*res) + n_regs * sizeof(res->vals[0]);
+	res = obstack_alloc(&obst, size);
+	memcpy(res, workset, size);
 	return res;
 }
 
 /**
- * Inserts the value @p val into the workset, iff it is not
- * already contained. The workset must not be full.
+ * Copy workset @param src to @param tgt
  */
-static INLINE void workset_insert(workset_t *ws, ir_node *val) {
-	int i;
-	/* check for current regclass */
-	if (arch_get_irn_reg_class(ws->bel->arch, val, -1) != ws->bel->cls) {
-		DBG((dbg, DBG_DECIDE, "Dropped %+F\n", val));
-		return;
-	}
-
-	/* check if val is already contained */
-	for(i=0; i<ws->len; ++i)
-		if (ws->vals[i].irn == val)
-			return;
+static void workset_copy(workset_t *dest, const workset_t *src)
+{
+	size_t size = sizeof(*src) + n_regs * sizeof(src->vals[0]);
+	memcpy(dest, src, size);
+}
 
-	/* insert val */
-	assert(ws->len < ws->bel->n_regs && "Workset already full!");
-	ws->vals[ws->len++].irn = val;
+/**
+ * Overwrites the current content array of @param ws with the
+ * @param count locations given at memory @param locs.
+ * Set the length of @param ws to count.
+ */
+static void workset_bulk_fill(workset_t *workset, int count, const loc_t *locs)
+{
+	workset->len = count;
+	memcpy(&(workset->vals[0]), locs, count * sizeof(locs[0]));
 }
 
 /**
- * Inserts all values in array @p vals of length @p cnt
- * into the workset. There must be enough space for the
- * entries.
+ * Inserts the value @p val into the workset, iff it is not
+ * already contained. The workset must not be full.
  */
-static INLINE void workset_bulk_insert(workset_t *ws, int cnt, ir_node **vals) {
-	int i, o;
-
-	for(o=0; o<cnt; ++o) {
-		ir_node *val = vals[o];
-		DBG((dbg, DBG_TRACE, "Bulk insert %+F\n", val));
-		/* check for current regclass */
-		if (arch_get_irn_reg_class(ws->bel->arch, val, -1) != ws->bel->cls) {
-			DBG((dbg, DBG_TRACE, "Wrong reg class\n"));
-			goto no_insert;
-		}
+static void workset_insert(workset_t *workset, ir_node *val, int reloaded)
+{
+	loc_t *loc;
+	int    i;
+	/* check for current regclass */
+	assert(arch_irn_consider_in_reg_alloc(arch_env, cls, val));
 
-		/* check if val is already contained */
-		for(i=0; i<ws->len; ++i)
-			if (ws->vals[i].irn == val) {
-				DBG((dbg, DBG_TRACE, "Already contained\n"));
-				goto no_insert;
+	/* check if val is already contained */
+	for (i = 0; i < workset->len; ++i) {
+		loc = &workset->vals[i];
+		if (loc->node == val) {
+			if(!loc->reloaded) {
+				loc->reloaded = reloaded;
 			}
-
-		/* insert val */
-		assert(ws->len < ws->bel->n_regs && "Workset does not have enough room!");
-		ws->vals[ws->len++].irn = val;
-		DBG((dbg, DBG_TRACE, "Inserted\n"));
-
-no_insert:
-		/*epsilon statement :)*/;
+			return;
+		}
 	}
-}
 
-/**
- * Overwrites the current contents of @p ws with the
- * locations given in @p locs
- */
-#define workset_bulk_fill(ws, count, locs) memcpy(&(ws)->vals[0], locs, ((ws)->len=count)*sizeof(locs[0]));
+	/* insert val */
+	assert(workset->len < n_regs && "Workset already full!");
+	loc           = &workset->vals[workset->len];
+	loc->node     = val;
+	loc->reloaded = reloaded;
+	loc->time     = 6666; /* undefined yet */
+	workset->len++;
+}
 
 /**
  * Removes all entries from this workset
  */
-#define workset_clear(ws) (ws)->len = 0;
+static void workset_clear(workset_t *workset)
+{
+	workset->len = 0;
+}
 
 /**
  * Removes the value @p val from the workset if present.
  */
-static INLINE void workset_remove(workset_t *ws, ir_node *val) {
+static INLINE void workset_remove(workset_t *workset, ir_node *val)
+{
 	int i;
-	for(i=0; i<ws->len; ++i)
-		if (ws->vals[i].irn == val) {
-			ws->vals[i] = ws->vals[--ws->len];
+	for(i = 0; i < workset->len; ++i) {
+		if (workset->vals[i].node == val) {
+			workset->vals[i] = workset->vals[--workset->len];
 			return;
 		}
+	}
 }
 
-static INLINE int workset_contains(const workset_t *ws, const ir_node *val) {
+static INLINE int workset_contains(const workset_t *ws, const ir_node *val)
+{
 	int i;
-	for(i=0; i<ws->len; ++i)
-		if (ws->vals[i].irn == val)
+
+	for(i=0; i<ws->len; ++i) {
+		if (ws->vals[i].node == val)
 			return 1;
+	}
+
 	return 0;
 }
 
-#define workset_foreach(ws, v)	for(ws->i=0; \
-									v=(ws->i < ws->len) ? ws->vals[ws->i].irn : NULL, ws->i < ws->len; \
-									ws->i++)
+/**
+ * Iterates over all values in the working set.
+ * @p ws The workset to iterate
+ * @p v  A variable to put the current value in
+ * @p i  An integer for internal use
+ */
+#define workset_foreach(ws, v, i)	for(i=0; \
+										v=(i < ws->len) ? ws->vals[i].node : NULL, i < ws->len; \
+										++i)
 
 #define workset_set_time(ws, i, t) (ws)->vals[i].time=t
+#define workset_get_time(ws, i) (ws)->vals[i].time
 #define workset_set_length(ws, length) (ws)->len = length
 #define workset_get_length(ws) ((ws)->len)
-#define workset_get_val(ws, i) ((ws)->vals[i].irn)
+#define workset_get_val(ws, i) ((ws)->vals[i].node)
 #define workset_sort(ws) qsort((ws)->vals, (ws)->len, sizeof((ws)->vals[0]), loc_compare);
 
+typedef struct _block_info_t
+{
+	workset_t *start_workset;
+	workset_t *end_workset;
+} block_info_t;
+
+
+static void *new_block_info(void)
+{
+	block_info_t *res = obstack_alloc(&obst, sizeof(res[0]));
+	memset(res, 0, sizeof(res[0]));
 
-static int is_mem_phi(const ir_node *irn, void *data) {
-	ir_node *blk = get_nodes_block(irn);
-	DBG((dbg, DBG_SPILL, "Is %+F a mem-phi?\n", irn));
-	workset_t *sws = ((block_info_t *)get_irn_link(blk))->ws_start;
-	DBG((dbg, DBG_SPILL, "  %d\n", !workset_contains(sws, irn)));
-	return !workset_contains(sws, irn);
+	return res;
 }
 
+#define get_block_info(block)        ((block_info_t *)get_irn_link(block))
+#define set_block_info(block, info)  set_irn_link(block, info)
+
 /**
- * Collects all values live-in at block @p blk and all phi results in this block.
- * Then it adds the best values (at most n_regs) to the ws.
+ * @return The distance to the next use or 0 if irn has dont_spill flag set
  */
-static void build_start_set(belady_env_t *bel, ir_node *blk) {
-	workset_t *ws = bel->ws;
-	ir_node *irn, *first;
-	irn_live_t *li;
-	int count;
-	loc_t loc, *starters;
-	struct obstack ob;
-
-	obstack_init(&ob);
-
-	/* get all values */
-	first = sched_first(blk);
-	count = 0;
-	sched_foreach(blk, irn)
-		if (is_Phi(irn) && arch_get_irn_reg_class(bel->arch, irn, -1) == bel->cls) {
-			loc.irn = irn;
-			loc.time = be_get_next_use(bel->uses, first, 0, irn, 0);
-			DBG((dbg, DBG_START, "  %+F next-use %d\n", loc.irn, loc.time));
-			obstack_grow(&ob, &loc, sizeof(loc));
-			count++;
-		} else
-			break;
+static INLINE unsigned get_distance(ir_node *from, unsigned from_step,
+                                    const ir_node *def, int skip_from_uses)
+{
+	be_next_use_t use;
+	int           flags = arch_irn_get_flags(arch_env, def);
+	unsigned      costs;
+	unsigned      time;
 
-	live_foreach(blk, li)
-		if (live_is_in(li) && arch_get_irn_reg_class(bel->arch, li->irn, -1) == bel->cls) {
-			loc.irn = (ir_node *)li->irn;
-			loc.time = be_get_next_use(bel->uses, first, 0, li->irn, 0);
-			DBG((dbg, DBG_START, "  %+F next-use %d\n", loc.irn, loc.time));
-			obstack_grow(&ob, &loc, sizeof(loc));
-			count++;
-		}
-	starters = obstack_finish(&ob);
+	assert(! (flags & arch_irn_flags_ignore));
 
-	/* sort all values */
-	qsort(starters, count, sizeof(starters[0]), loc_compare);
+	use = be_get_next_use(uses, from, from_step, def, skip_from_uses);
+	if(USES_IS_INFINITE(use.time))
+		return USES_INFINITY;
 
-	/* copy the best ones to the ws */
-	count = MIN(count, ws->bel->n_regs);
-	workset_bulk_fill(ws, count, starters);
+	/* We have to keep nonspillable nodes in the workingset */
+	if(flags & arch_irn_flags_dont_spill)
+		return 0;
 
-	obstack_free(&ob, NULL);
+	costs = be_get_reload_costs_no_weight(senv, def, use.before);
+	assert(costs * RELOAD_COST_FACTOR < 1000);
+	time  = use.time + 1000 - (costs * RELOAD_COST_FACTOR);
+
+	return time;
 }
 
 /**
- * Performs the actions neccessary to grant the request that:
+ * Performs the actions necessary to grant the request that:
  * - new_vals can be held in registers
  * - as few as possible other values are disposed
  * - the worst values get disposed
@@ -249,263 +304,584 @@ static void build_start_set(belady_env_t *bel, ir_node *blk) {
  * @p is_usage indicates that the values in new_vals are used (not defined)
  * In this case reloads must be performed
  */
-static void displace(belady_env_t *bel, workset_t *new_vals, int is_usage) {
-	ir_node *val;
-	int i, len, max_allowed, demand;
-	workset_t *ws = bel->ws;
-	ir_node **to_insert = alloca(bel->n_regs * sizeof(*to_insert));
-
-	/*
-	 * 1. Identify the number of needed slots and the values to reload
-	 */
+static void displace(workset_t *new_vals, int is_usage)
+{
+	ir_node **to_insert = alloca(n_regs * sizeof(to_insert[0]));
+	ir_node  *val;
+	int       i;
+	int       len;
+	int       spills_needed;
+	int       demand;
+	int       iter;
+
+	/* 1. Identify the number of needed slots and the values to reload */
 	demand = 0;
-	workset_foreach(new_vals, val) {
+	workset_foreach(new_vals, val, iter) {
 		/* mark value as used */
 		if (is_usage)
-			pset_insert_ptr(bel->used, val);
+			ir_nodeset_insert(&used, val);
 
-		if (!workset_contains(ws, val)) {
+		if (! workset_contains(ws, val)) {
 			DBG((dbg, DBG_DECIDE, "    insert %+F\n", val));
-			to_insert[demand++] = val;
-			if (is_usage)
-				be_add_reload(bel->senv, val, bel->instr);
-		} else
-			DBG((dbg, DBG_DECIDE, "    skip %+F\n", val));
+			if (is_usage) {
+				DBG((dbg, DBG_SPILL, "Reload %+F before %+F\n", val, instr));
+				be_add_reload(senv, val, instr, cls, 1);
+			}
+		} else {
+			DBG((dbg, DBG_DECIDE, "    %+F already in workset\n", val));
+			assert(is_usage);
+			/* remove the value from the current workset so it is not accidently
+			 * spilled */
+			workset_remove(ws, val);
+		}
+		to_insert[demand++] = val;
 	}
-	DBG((dbg, DBG_DECIDE, "    demand = %d\n", demand));
-
 
-	/*
-	 * 2. Make room for at least 'demand' slots
-	 */
-	len = workset_get_length(ws);
-	max_allowed = bel->n_regs - demand;
+	/* 2. Make room for at least 'demand' slots */
+	len           = workset_get_length(ws);
+	spills_needed = len + demand - n_regs;
+	assert(spills_needed <= len);
 
 	/* Only make more free room if we do not have enough */
-	if (len > max_allowed) {
-		/* get current next-use distance */
-		for (i=0; i<ws->len; ++i)
-			workset_set_time(ws, i, be_get_next_use(bel->uses, bel->instr, bel->instr_nr, workset_get_val(ws, i), !is_usage));
+	if (spills_needed > 0) {
+		ir_node   *curr_bb  = get_nodes_block(instr);
+		workset_t *ws_start = get_block_info(curr_bb)->start_workset;
+
+		DBG((dbg, DBG_DECIDE, "    disposing %d values\n", spills_needed));
+
+		/* calculate current next-use distance for live values */
+		for (i = 0; i < len; ++i) {
+			ir_node  *val  = workset_get_val(ws, i);
+			unsigned  dist = get_distance(instr, instr_nr, val, !is_usage);
+			workset_set_time(ws, i, dist);
+		}
 
 		/* sort entries by increasing nextuse-distance*/
 		workset_sort(ws);
 
 		/* Logic for not needed live-ins: If a value is disposed
-		   before its first usage, remove it from start workset */
-		for (i=max_allowed; i<ws->len; ++i) {
-			ir_node *irn = ws->vals[i].irn;
-			if (!pset_find_ptr(bel->used, irn)) {
-				ir_node *curr_bb = get_nodes_block(bel->instr);
-				workset_t *ws_start = ((block_info_t *) get_irn_link(curr_bb))->ws_start;
-				workset_remove(ws_start, irn);
-
-				DBG((dbg, DBG_DECIDE, "    dispose %+F dumb\n", irn));
-			} else
-				DBG((dbg, DBG_DECIDE, "    dispose %+F\n", irn));
+		 * before its first usage, remove it from start workset
+		 * We don't do this for phis though	*/
+		for (i = len - spills_needed; i < len; ++i) {
+			ir_node *val = ws->vals[i].node;
+
+			DBG((dbg, DBG_DECIDE, "    disposing node %+F (%u)\n", val,
+			     workset_get_time(ws, i)));
+
+			if(!USES_IS_INFINITE(ws->vals[i].time)
+					&& !ws->vals[i].reloaded) {
+				//be_add_spill(senv, val, instr);
+			}
+
+			if (! ir_nodeset_contains(&used, val)) {
+				workset_remove(ws_start, val);
+				DBG((dbg, DBG_DECIDE, "    (and removing %+F from start workset)\n", val));
+			}
 		}
 
 		/* kill the last 'demand' entries in the array */
-		workset_set_length(ws, max_allowed);
+		workset_set_length(ws, len - spills_needed);
+	}
+
+	/* 3. Insert the new values into the workset */
+	for (i = 0; i < demand; ++i) {
+		ir_node *val = to_insert[i];
+
+		workset_insert(ws, val, 1);
+	}
+}
+
+/** Decides whether a specific node should be in the start workset or not
+ *
+ * @param env      belady environment
+ * @param first
+ * @param node     the node to test
+ * @param loop     the loop of the node
+ */
+static loc_t to_take_or_not_to_take(ir_node* first, ir_node *node,
+                                    ir_loop *loop)
+{
+	be_next_use_t next_use;
+	loc_t         loc;
+
+	loc.time     = USES_INFINITY;
+	loc.node     = node;
+	//loc.reloaded = rand() % 2; /* provoke a bug... */
+	loc.reloaded = 0;
+
+	if (!arch_irn_consider_in_reg_alloc(arch_env, cls, node)) {
+		loc.time = USES_INFINITY;
+		return loc;
+	}
+
+	/* We have to keep nonspillable nodes in the workingset */
+	if(arch_irn_get_flags(arch_env, node) & arch_irn_flags_dont_spill) {
+		loc.time = 0;
+		DBG((dbg, DBG_START, "    %+F taken (dontspill node)\n", node, loc.time));
+		return loc;
+	}
+
+	next_use = be_get_next_use(uses, first, 0, node, 0);
+	if(USES_IS_INFINITE(next_use.time)) {
+		// the nodes marked as live in shouldn't be dead, so it must be a phi
+		assert(is_Phi(node));
+		loc.time = USES_INFINITY;
+		DBG((dbg, DBG_START, "    %+F not taken (dead)\n", node));
+		if(is_Phi(node)) {
+			be_spill_phi(senv, node);
+		}
+		return loc;
 	}
 
-	/*
-	 * 3. Insert the new values into the workset
-	 */
-	workset_bulk_insert(bel->ws, demand, to_insert);
+	loc.time = next_use.time;
+
+	if(next_use.outermost_loop >= get_loop_depth(loop)) {
+		DBG((dbg, DBG_START, "    %+F taken (%u, loop %d)\n", node, loc.time, next_use.outermost_loop));
+	} else {
+		loc.time = USES_PENDING;
+		DBG((dbg, DBG_START, "    %+F delayed (outerloopdepth %d < loopdetph %d)\n", node, next_use.outermost_loop, get_loop_depth(loop)));
+	}
+	return loc;
 }
 
 /**
- * For the given block @p blk, decide for each values
+ * Computes the start-workset for a block with multiple predecessors. We assume
+ * that at least 1 of the predeccesors is a back-edge which means we're at the
+ * beginning of a loop. We try to reload as much values as possible now so they
+ * don't get reloaded inside the loop.
+ */
+static void compute_live_ins(const ir_node *block)
+{
+	ir_loop    *loop = get_irn_loop(block);
+	ir_node    *first;
+	ir_node    *node;
+	loc_t       loc;
+	loc_t      *starters;
+	loc_t      *delayed;
+	int         i, len, ws_count;
+	int	        free_slots, free_pressure_slots;
+	unsigned    pressure;
+	//int arity;
+	//int         n_pred_worksets;
+	//workset_t **pred_worksets;
+
+	/* Collect all values living at start of block */
+	starters = NEW_ARR_F(loc_t, 0);
+	delayed  = NEW_ARR_F(loc_t, 0);
+
+	DBG((dbg, DBG_START, "Living at start of %+F:\n", block));
+	first = sched_first(block);
+
+	/* check all Phis first */
+	sched_foreach(block, node) {
+		if (! is_Phi(node))
+			break;
+
+		loc = to_take_or_not_to_take(first, node, loop);
+
+		if (! USES_IS_INFINITE(loc.time)) {
+			if (USES_IS_PENDING(loc.time))
+				ARR_APP1(loc_t, delayed, loc);
+			else
+				ARR_APP1(loc_t, starters, loc);
+		}
+	}
+
+	/* check all Live-Ins */
+	be_lv_foreach(lv, block, be_lv_state_in, i) {
+		ir_node *node = be_lv_get_irn(lv, block, i);
+
+		loc = to_take_or_not_to_take(first, node, loop);
+
+		if (! USES_IS_INFINITE(loc.time)) {
+			if (USES_IS_PENDING(loc.time))
+				ARR_APP1(loc_t, delayed, loc);
+			else
+				ARR_APP1(loc_t, starters, loc);
+		}
+	}
+
+	pressure            = be_get_loop_pressure(loop_ana, cls, loop);
+	assert(ARR_LEN(delayed) <= (signed)pressure);
+	free_slots          = n_regs - ARR_LEN(starters);
+	free_pressure_slots = n_regs - (pressure - ARR_LEN(delayed));
+	free_slots          = MIN(free_slots, free_pressure_slots);
+
+	/* so far we only put nodes into the starters list that are used inside
+	 * the loop. If register pressure in the loop is low then we can take some
+	 * values and let them live through the loop */
+	if(free_slots > 0) {
+		qsort(delayed, ARR_LEN(delayed), sizeof(delayed[0]), loc_compare);
+
+		for (i = 0; i < ARR_LEN(delayed) && i < free_slots; ++i) {
+			DBG((dbg, DBG_START, "    delayed %+F taken\n", delayed[i].node));
+			ARR_APP1(loc_t, starters, delayed[i]);
+			delayed[i].node = NULL;
+		}
+	}
+
+	/* spill phis (the actual phis not just their values) that are in this block
+	 * but not in the start workset */
+	for (i = ARR_LEN(delayed) - 1; i >= 0; --i) {
+		ir_node *node = delayed[i].node;
+		if(node == NULL || !is_Phi(node) || get_nodes_block(node) != block)
+			continue;
+
+		DBG((dbg, DBG_START, "    spilling delayed phi %+F\n", node));
+		be_spill_phi(senv, node);
+	}
+	DEL_ARR_F(delayed);
+
+	/* Sort start values by first use */
+	qsort(starters, ARR_LEN(starters), sizeof(starters[0]), loc_compare);
+
+	/* Copy the best ones from starters to start workset */
+	ws_count = MIN(ARR_LEN(starters), n_regs);
+	workset_clear(ws);
+	workset_bulk_fill(ws, ws_count, starters);
+
+	/* spill phis (the actual phis not just their values) that are in this block
+	 * but not in the start workset */
+	len = ARR_LEN(starters);
+	for (i = ws_count; i < len; ++i) {
+		ir_node *node = starters[i].node;
+		if (! is_Phi(node) || get_nodes_block(node) != block)
+			continue;
+
+		DBG((dbg, DBG_START, "    spilling phi %+F\n", node));
+		be_spill_phi(senv, node);
+	}
+
+	DEL_ARR_F(starters);
+
+#if 0
+	/* determine reloaded status of the values: If there's 1 pred block (which
+	 * is no backedge) where the value is reloaded then we must set it to
+	 * reloaded here. We place spills in all pred where the value was not yet
+	 * reloaded to be sure we have a spill on each path */
+	n_pred_worksets = 0;
+	arity           = get_irn_arity(block);
+	pred_worksets   = alloca(sizeof(pred_worksets[0]) * arity);
+	for(i = 0; i < arity; ++i) {
+		ir_node      *pred_block = get_Block_cfgpred_block(block, i);
+		block_info_t *pred_info  = get_block_info(pred_block);
+		if(pred_info == NULL)
+			continue;
+
+		pred_worksets[n_pred_worksets] = pred_info->end_workset;
+		++n_pred_worksets;
+	}
+
+	for(i = 0; i < ws_count; ++i) {
+		loc_t   *loc   = &ws->vals[i];
+		ir_node *value = loc->node;
+		int      reloaded;
+		int      n;
+
+		/* phis from this block aren't reloaded */
+		if(get_nodes_block(value) == block) {
+			assert(is_Phi(value));
+			loc->reloaded = value_not_reloaded;
+			continue;
+		}
+
+		/* was the value reloaded on any of the other inputs */
+		reloaded = 0;
+		arity    = get_Block_n_cfgpreds(block);
+		for(n = 0; n < n_pred_worksets; ++n) {
+			workset_t *pred_workset = pred_worksets[n];
+			int        p_len        = workset_get_length(pred_workset);
+			int        p;
+
+			for(p = 0; p < p_len; ++p) {
+				loc_t *l = &pred_workset->vals[p];
+				if(l->node == value) {
+					if(l->reloaded) {
+						reloaded = 1;
+					}
+					break;
+				}
+			}
+			if(p >= p_len) {
+				reloaded = 1;
+				break;
+			}
+		}
+	}
+#endif
+}
+
+/**
+ * For the given block @p block, decide for each values
  * whether it is used from a register or is reloaded
  * before the use.
  */
-static void decide(ir_node *blk, void *env) {
-	belady_env_t *bel = env;
-	workset_t *new_vals;
-	ir_node *irn;
-#ifdef SINGLE_START_PROJS
-	ir_node *start_blk = get_irg_start_block(get_irn_irg(blk));
-#endif
-	block_info_t *blk_info = obstack_alloc(&bel->ob, sizeof(*blk_info));
-	set_irn_link(blk, blk_info);
+static void belady(ir_node *block)
+{
+	workset_t       *new_vals;
+	ir_node         *irn;
+	int              iter;
+	block_info_t    *block_info;
+	int              i, arity;
+	int              has_backedges = 0;
+	//int              first         = 0;
+	const ir_edge_t *edge;
+
+	/* no need to process a block twice */
+	if(get_block_info(block) != NULL) {
+		return;
+	}
+
+	/* check if all predecessor blocks are processed yet (though for backedges
+	 * we have to make an exception as we can't process them first) */
+	arity = get_Block_n_cfgpreds(block);
+	for(i = 0; i < arity; ++i) {
+		ir_node      *pred_block = get_Block_cfgpred_block(block, i);
+		block_info_t *pred_info  = get_block_info(pred_block);
+
+		if(pred_info == NULL) {
+			/* process predecessor first (it will be in the queue already) */
+			if(!is_backedge(block, i)) {
+				return;
+			}
+			has_backedges = 1;
+		}
+	}
+	(void) has_backedges;
+	if(arity == 0) {
+		workset_clear(ws);
+	} else if(arity == 1) {
+		ir_node      *pred_block = get_Block_cfgpred_block(block, 0);
+		block_info_t *pred_info  = get_block_info(pred_block);
+
+		assert(pred_info != NULL);
+		workset_copy(ws, pred_info->end_workset);
+	} else {
+		/* we need 2 heuristics here, for the case when all predecessor blocks
+		 * are known and when some are backedges (and therefore can't be known
+		 * yet) */
+		compute_live_ins(block);
+	}
 
 	DBG((dbg, DBG_DECIDE, "\n"));
-	DBG((dbg, DBG_DECIDE, "Decide for %+F\n", blk));
+	DBG((dbg, DBG_DECIDE, "Decide for %+F\n", block));
 
-	/* build starting-workset for this block */
-	build_start_set(bel, blk);
-	blk_info->ws_start = workset_clone(&bel->ob, bel->ws);
-	DBG((dbg, DBG_WSETS, "Initial start workset for %+F:\n", blk));
-	workset_foreach(blk_info->ws_start, irn)
-		DBG((dbg, DBG_WSETS, "  %+F\n", irn));
+	block_info = new_block_info();
+	set_block_info(block, block_info);
+
+	DBG((dbg, DBG_WSETS, "Start workset for %+F:\n", block));
+	workset_foreach(ws, irn, iter) {
+		DBG((dbg, DBG_WSETS, "  %+F (%u)\n", irn,
+		     workset_get_time(ws, iter)));
+	}
+
+	block_info->start_workset = workset_clone(ws);
 
 	/* process the block from start to end */
 	DBG((dbg, DBG_WSETS, "Processing...\n"));
-	bel->used = pset_new_ptr(32);
-	bel->instr_nr = 0;
-	new_vals = new_workset(&bel->ob, bel);
-	sched_foreach(blk, irn) {
-		assert(workset_get_length(bel->ws) <= bel->n_regs && "Too much values in workset!");
-
-
-#ifdef SINGLE_START_PROJS
-		if (is_Phi(irn) ||
-			(is_Proj(irn) && blk!=start_blk) ||
-			(get_irn_mode(irn) == mode_T && blk==start_blk)) {
-			DBG((dbg, DBG_DECIDE, "  ...%+F skipped\n", irn));
-			continue;
-		}
-#else
-		/* projs are handled with the tuple value.
-		 * Phis are no real instr (see insert_starters)
-		 * instr_nr does not increase */
-		if (is_Proj(irn) || is_Phi(irn)) {
-			DBG((dbg, DBG_DECIDE, "  ...%+F skipped\n", irn));
+	ir_nodeset_init(&used);
+	instr_nr = 0;
+	/* TODO: this leaks (into the obstack)... */
+	new_vals = new_workset();
+
+	sched_foreach(block, irn) {
+		int i, arity;
+		assert(workset_get_length(ws) <= n_regs);
+
+		/* Phis are no real instr (see insert_starters()) */
+		if (is_Phi(irn)) {
 			continue;
 		}
-#endif
 		DBG((dbg, DBG_DECIDE, "  ...%+F\n", irn));
 
 		/* set instruction in the workset */
-		bel->instr = irn;
+		instr = irn;
 
 		/* allocate all values _used_ by this instruction */
 		workset_clear(new_vals);
-		workset_bulk_insert(new_vals, get_irn_arity(irn)+1, get_irn_in(irn));
-		displace(bel, new_vals, 1);
+		for(i = 0, arity = get_irn_arity(irn); i < arity; ++i) {
+			ir_node *in = get_irn_n(irn, i);
+			if (!arch_irn_consider_in_reg_alloc(arch_env, cls, in))
+				continue;
+
+			/* (note that reloaded_value is irrelevant here) */
+			workset_insert(new_vals, in, 0);
+		}
+		displace(new_vals, 1);
 
 		/* allocate all values _defined_ by this instruction */
 		workset_clear(new_vals);
-		if (get_irn_mode(irn) == mode_T) { /* special handling for tuples and projs */
-			ir_node *proj;
-			for(proj=sched_next(irn); is_Proj(proj); proj=sched_next(proj))
-				workset_insert(new_vals, proj);
+		if (get_irn_mode(irn) == mode_T) {
+			const ir_edge_t *edge;
+
+			foreach_out_edge(irn, edge) {
+				ir_node *proj = get_edge_src_irn(edge);
+				if (!arch_irn_consider_in_reg_alloc(arch_env, cls, proj))
+					continue;
+				workset_insert(new_vals, proj, 0);
+			}
 		} else {
-			workset_insert(new_vals, irn);
+			if (!arch_irn_consider_in_reg_alloc(arch_env, cls, irn))
+				continue;
+			workset_insert(new_vals, irn, 0);
 		}
-		displace(bel, new_vals, 0);
+		displace(new_vals, 0);
 
-		bel->instr_nr++;
+		instr_nr++;
 	}
-	del_pset(bel->used);
+	ir_nodeset_destroy(&used);
 
 	/* Remember end-workset for this block */
-	blk_info->ws_end = workset_clone(&bel->ob, bel->ws);
-	DBG((dbg, DBG_WSETS, "Start workset for %+F:\n", blk));
-	workset_foreach(blk_info->ws_start, irn)
-		DBG((dbg, DBG_WSETS, "  %+F\n", irn));
-	DBG((dbg, DBG_WSETS, "End workset for %+F:\n", blk));
-	workset_foreach(blk_info->ws_end, irn)
-		DBG((dbg, DBG_WSETS, "  %+F\n", irn));
+	block_info->end_workset = workset_clone(ws);
+	DBG((dbg, DBG_WSETS, "End workset for %+F:\n", block));
+	workset_foreach(ws, irn, iter)
+		DBG((dbg, DBG_WSETS, "  %+F (%u)\n", irn,
+		     workset_get_time(ws, iter)));
+
+	/* add successor blocks into worklist */
+	foreach_block_succ(block, edge) {
+		ir_node *succ = get_edge_src_irn(edge);
+		pdeq_putr(worklist, succ);
+	}
 }
 
 /**
- * 'decide' is block-local and makes assumtions
+ * 'decide' is block-local and makes assumptions
  * about the set of live-ins. Thus we must adapt the
  * live-outs to the live-ins at each block-border.
  */
-static void fix_block_borders(ir_node *blk, void *env) {
-	belady_env_t *bel = env;
-	int i, max;
+static void fix_block_borders(ir_node *block, void *data)
+{
+	workset_t    *start_workset;
+	int           arity;
+	int           i;
+	int           iter;
+	(void) data;
 
 	DBG((dbg, DBG_FIX, "\n"));
-	DBG((dbg, DBG_FIX, "Fixing %+F\n", blk));
+	DBG((dbg, DBG_FIX, "Fixing %+F\n", block));
 
-	workset_t *wsb = ((block_info_t *)get_irn_link(blk))->ws_start;
+	start_workset = get_block_info(block)->start_workset;
 
 	/* process all pred blocks */
-	for (i=0, max=get_irn_arity(blk); i<max; ++i) {
-		ir_node *irnb, *irnp, *pred = get_Block_cfgpred_block(blk, i);
-		workset_t *wsp = ((block_info_t *)get_irn_link(pred))->ws_end;
+	arity = get_irn_arity(block);
+	for (i = 0; i < arity; ++i) {
+		ir_node   *pred = get_Block_cfgpred_block(block, i);
+		workset_t *pred_end_workset = get_block_info(pred)->end_workset;
+		ir_node   *node;
 
 		DBG((dbg, DBG_FIX, "  Pred %+F\n", pred));
 
-		workset_foreach(wsb, irnb) {
-			/* if irnb is a phi of the current block we reload
-			 * the corresponding argument, else irnb itself */
-			if(is_Phi(irnb) && blk == get_nodes_block(irnb))
-				irnb = get_irn_n(irnb, i);
+		/* spill all values not used anymore */
+		workset_foreach(pred_end_workset, node, iter) {
+			ir_node *n2;
+			int      iter2;
+			int      found = 0;
+			workset_foreach(start_workset, n2, iter2) {
+				if(n2 == node) {
+					found = 1;
+					break;
+				}
+				/* note that we do not look at phi inputs, becuase the values
+				 * will be either live-end and need no spill or
+				 * they have other users in which must be somewhere else in the
+				 * workset */
+			}
 
-			/* Unknowns are available everywhere */
-			if(get_irn_opcode(irnb) == iro_Unknown)
-				continue;
+#if 0
+			if(!found && be_is_live_out(lv, pred, node)
+					&& !pred_end_workset->vals[iter].reloaded) {
+				ir_node *insert_point
+					= be_get_end_of_block_insertion_point(pred);
+				DBG((dbg, DBG_SPILL, "Spill %+F before %+F\n", node,
+				     insert_point));
+				be_add_spill(senv, node, insert_point);
+			}
+#endif
+		}
+
+		/* reload missing values in predecessors */
+		workset_foreach(start_workset, node, iter) {
+			/* if node is a phi of the current block we reload
+			 * the corresponding argument, else node itself */
+			if(is_Phi(node) && block == get_nodes_block(node)) {
+				node = get_irn_n(node, i);
 
-			/* check if irnb is in a register at end of pred */
-			workset_foreach(wsp, irnp)
-				if (irnb == irnp)
-					goto next_value;
+				/* we might have unknowns as argument for the phi */
+				if(!arch_irn_consider_in_reg_alloc(arch_env, cls, node))
+					continue;
+			}
 
-			/* irnb is in memory at the end of pred, so we have to reload it */
-			DBG((dbg, DBG_FIX, "    reload %+F\n", irnb));
-			be_add_reload_on_edge(bel->senv, irnb, blk, i);
+			/* check if node is in a register at end of pred */
+			if(workset_contains(pred_end_workset, node))
+				continue;
 
-next_value:
-			/*epsilon statement :)*/;
+			/* node is not in memory at the end of pred -> reload it */
+			DBG((dbg, DBG_FIX, "    reload %+F\n", node));
+			DBG((dbg, DBG_SPILL, "Reload %+F before %+F,%d\n", node, block, i));
+			be_add_reload_on_edge(senv, node, block, i, cls, 1);
 		}
 	}
 }
 
-/**
- * Removes all used reloads from bel->reloads.
- * The remaining nodes in bel->reloads will be removed from the graph.
- */
-static void rescue_used_reloads(ir_node *irn, void *env) {
-	pset *rlds = (pset *)env;
-	if (pset_find_ptr(rlds, irn))
-		pset_remove_ptr(rlds, irn);
-}
-
-/**
- * Finds all unused reloads and remove them from the schedule
- * Also removes spills if they are not used anymore after removing reloads
- */
-static void remove_unused_reloads(ir_graph *irg, belady_env_t *bel) {
-	ir_node *irn;
+static void be_spill_belady(be_irg_t *birg, const arch_register_class_t *rcls)
+{
+	ir_graph *irg = be_get_birg_irg(birg);
 
-	irg_walk_graph(irg, rescue_used_reloads, NULL, bel->reloads);
-	for(irn = pset_first(bel->reloads); irn; irn = pset_next(bel->reloads)) {
-		DBG((dbg, DBG_SPILL, "Removing %+F before %+F in %+F\n", irn, sched_next(irn), get_nodes_block(irn)));
+	be_liveness_assure_sets(be_assure_liveness(birg));
 
-		ir_node *spill = get_irn_n(irn, 0);
+	/* construct control flow loop tree */
+	if(! (get_irg_loopinfo_state(irg) & loopinfo_cf_consistent)) {
+		construct_cf_backedges(irg);
+	}
 
-		/* remove reaload */
-		set_irn_n(irn, 0, new_Bad());
-		sched_remove(irn);
+	be_clear_links(irg);
 
-		/* if spill not used anymore, remove it too
-		 * test of regclass is necessary since spill may be a phi-M */
-		if (get_irn_n_edges(spill) == 0 && bel->cls == arch_get_irn_reg_class(bel->arch, spill, -1)) {
-			set_irn_n(spill, 0, new_Bad());
-			sched_remove(spill);
-		}
+	/* init belady env */
+	obstack_init(&obst);
+	arch_env = birg->main_env->arch_env;
+	cls      = rcls;
+	lv       = be_get_birg_liveness(birg);
+	n_regs   = cls->n_regs - be_put_ignore_regs(birg, cls, NULL);
+	ws       = new_workset();
+	uses     = be_begin_uses(irg, lv);
+	loop_ana = be_new_loop_pressure(birg);
+	senv     = be_new_spill_env(birg);
+	worklist = new_pdeq();
+
+	pdeq_putr(worklist, get_irg_start_block(irg));
+
+	while(!pdeq_empty(worklist)) {
+		ir_node *block = pdeq_getl(worklist);
+		belady(block);
 	}
-}
+	/* end block might not be reachable in endless loops */
+	belady(get_irg_end_block(irg));
 
-void be_spill_belady(const be_main_session_env_t *session, const arch_register_class_t *cls) {
-	dbg = firm_dbg_register("ir.be.spillbelady");
-	firm_dbg_set_mask(dbg, DEBUG_LVL);
+	del_pdeq(worklist);
 
-	/* init belady env */
-	belady_env_t *bel = alloca(sizeof(*bel));
-	obstack_init(&bel->ob);
-	bel->factory = session->main_env->node_factory;
-	bel->arch = session->main_env->arch_env;
-	bel->cls = cls;
-	bel->n_regs = arch_register_class_n_regs(cls);
-	bel->ws = new_workset(&bel->ob, bel);
-	bel->uses = be_begin_uses(session->irg, session->main_env->arch_env, cls);
-	bel->senv = be_new_spill_env(dbg, session, cls, is_mem_phi, NULL);
-	bel->reloads = pset_new_ptr_default();
-
-	/* do the work */
-	irg_block_walk_graph(session->irg, decide, NULL, bel);
-	irg_block_walk_graph(session->irg, fix_block_borders, NULL, bel);
-	be_insert_spills_reloads(bel->senv, bel->reloads);
-	remove_unused_reloads(session->irg, bel);
+	/* belady was block-local, fix the global flow by adding reloads on the
+	 * edges */
+	irg_block_walk_graph(irg, fix_block_borders, NULL, NULL);
+
+	/* Insert spill/reload nodes into the graph and fix usages */
+	be_insert_spills_reloads(senv);
 
 	/* clean up */
-	del_pset(bel->reloads);
-	be_delete_spill_env(bel->senv);
-	be_end_uses(bel->uses);
-	obstack_free(&bel->ob, NULL);
+	be_delete_spill_env(senv);
+	be_end_uses(uses);
+	be_free_loop_pressure(loop_ana);
+	obstack_free(&obst, NULL);
 }
+
+void be_init_spillbelady(void)
+{
+	static be_spiller_t belady_spiller = {
+		be_spill_belady
+	};
+
+	be_register_spiller("belady", &belady_spiller);
+	FIRM_DBG_REGISTER(dbg, "firm.be.spill.belady");
+}
+
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spillbelady);