introduce be_foreach_use and use it
[libfirm] / ir / be / bespillbelady.c
index 4857e37..3b2755c 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
+ * Copyright (C) 1995-2011 University of Karlsruhe.  All right reserved.
  *
  * This file is part of libFirm.
  *
  * @brief       Beladys spillalgorithm.
  * @author      Daniel Grund, Matthias Braun
  * @date        20.09.2005
- * @version     $Id$
  */
-#ifdef HAVE_CONFIG_H
 #include "config.h"
-#endif
 
 #include <stdbool.h>
 
 #include "obst.h"
-#include "irprintf_t.h"
 #include "irgraph.h"
 #include "irnode.h"
 #include "irmode.h"
 #include "ircons_t.h"
 #include "irprintf.h"
 #include "irnodeset.h"
-#include "xmalloc.h"
-#include "pdeq.h"
+#include "irtools.h"
+#include "statev_t.h"
+#include "util.h"
 
 #include "beutil.h"
-#include "bearch_t.h"
+#include "bearch.h"
 #include "beuses.h"
-#include "besched_t.h"
+#include "besched.h"
 #include "beirgmod.h"
 #include "belive_t.h"
-#include "benode_t.h"
+#include "benode.h"
 #include "bechordal_t.h"
-#include "bespilloptions.h"
-#include "beloopana.h"
-#include "beirg_t.h"
 #include "bespill.h"
+#include "beloopana.h"
+#include "beirg.h"
+#include "bespillutil.h"
 #include "bemodule.h"
 
 #define DBG_SPILL     1
@@ -70,80 +67,53 @@ DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
 
 #define TIME_UNDEFINED 6666
 
-//#define LOOK_AT_LOOPDEPTH
-
 /**
  * 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). */
-       bool              spilled;  /**< the value was already spilled on this path */
+       bool              spilled;  /**< value was already spilled on this path */
 } loc_t;
 
-typedef struct _workset_t {
-       int   len;          /**< current length */
-       loc_t vals[0];      /**< inlined array of the values/distances in this working set */
+typedef struct workset_t {
+       unsigned len;     /**< current length */
+       loc_t    vals[];  /**< 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 unsigned                     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 ir_node                    **blocklist;
 
-static bool                         move_spills      = true;
-static bool                         respectloopdepth = true;
-static bool                         improve_known_preds = true;
+static int                          move_spills      = true;
+static int                          respectloopdepth = true;
+static int                          improve_known_preds = true;
 /* factor to weight the different costs of reloading/rematerializing a node
    (see bespill.h be_get_reload_costs_no_weight) */
 static int                          remat_bonus      = 10;
 
 static const lc_opt_table_entry_t options[] = {
        LC_OPT_ENT_BOOL   ("movespills", "try to move spills out of loops", &move_spills),
-       LC_OPT_ENT_BOOL   ("respectloopdepth", "exprimental (outermost loop cutting)", &respectloopdepth),
-       LC_OPT_ENT_BOOL   ("improveknownpreds", "experimental (known preds cutting)", &improve_known_preds),
+       LC_OPT_ENT_BOOL   ("respectloopdepth", "outermost loop cutting", &respectloopdepth),
+       LC_OPT_ENT_BOOL   ("improveknownpreds", "known preds cutting", &improve_known_preds),
        LC_OPT_ENT_INT    ("rematbonus", "give bonus to rematerialisable nodes", &remat_bonus),
        LC_OPT_LAST
 };
 
-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 workset_t *new_workset(void)
 {
-       workset_t *res;
-       size_t     size = sizeof(*res) + n_regs * sizeof(res->vals[0]);
-
-       res  = obstack_alloc(&obst, size);
-       memset(res, 0, size);
-       return res;
+       return OALLOCFZ(&obst, workset_t, vals, n_regs);
 }
 
 /**
@@ -151,10 +121,8 @@ static workset_t *new_workset(void)
  */
 static workset_t *workset_clone(workset_t *workset)
 {
-       workset_t *res;
-       size_t size = sizeof(*res) + n_regs * sizeof(res->vals[0]);
-       res = obstack_alloc(&obst, size);
-       memcpy(res, workset, size);
+       workset_t *res = OALLOCF(&obst, workset_t, vals, n_regs);
+       memcpy(res, workset, sizeof(*res) + n_regs * sizeof(res->vals[0]));
        return res;
 }
 
@@ -184,10 +152,10 @@ static void workset_bulk_fill(workset_t *workset, int count, const loc_t *locs)
  */
 static void workset_insert(workset_t *workset, ir_node *val, bool spilled)
 {
-       loc_t *loc;
-       int    i;
+       loc_t    *loc;
+       unsigned  i;
        /* check for current regclass */
-       assert(arch_irn_consider_in_reg_alloc(arch_env, cls, val));
+       assert(arch_irn_consider_in_reg_alloc(cls, val));
 
        /* check if val is already contained */
        for (i = 0; i < workset->len; ++i) {
@@ -220,10 +188,10 @@ static void workset_clear(workset_t *workset)
 /**
  * Removes the value @p val from the workset if present.
  */
-static INLINE void workset_remove(workset_t *workset, ir_node *val)
+static void workset_remove(workset_t *workset, ir_node *val)
 {
-       int i;
-       for(i = 0; i < workset->len; ++i) {
+       unsigned i;
+       for (i = 0; i < workset->len; ++i) {
                if (workset->vals[i].node == val) {
                        workset->vals[i] = workset->vals[--workset->len];
                        return;
@@ -231,11 +199,9 @@ static INLINE void workset_remove(workset_t *workset, ir_node *val)
        }
 }
 
-static INLINE const loc_t *workset_contains(const workset_t *ws,
-                                            const ir_node *val)
+static const loc_t *workset_contains(const workset_t *ws, const ir_node *val)
 {
-       int i;
-
+       unsigned i;
        for (i = 0; i < ws->len; ++i) {
                if (ws->vals[i].node == val)
                        return &ws->vals[i];
@@ -244,61 +210,99 @@ static INLINE const loc_t *workset_contains(const workset_t *ws,
        return NULL;
 }
 
+static int loc_compare(const void *a, const void *b)
+{
+       const loc_t   *p  = ((const loc_t*) a);
+       const loc_t   *q  = ((const loc_t*) b);
+       const unsigned pt = p->time;
+       const unsigned qt = q->time;
+
+       if (pt < qt)
+               return -1;
+       if (pt > qt)
+               return 1;
+
+       return get_irn_node_nr(p->node) - get_irn_node_nr(q->node);
+}
+
+static void workset_sort(workset_t *workset)
+{
+       qsort(workset->vals, workset->len, sizeof(workset->vals[0]), loc_compare);
+}
+
+static inline unsigned workset_get_time(const workset_t *workset, unsigned idx)
+{
+       return workset->vals[idx].time;
+}
+
+static inline void workset_set_time(workset_t *workset, unsigned idx,
+                                    unsigned time)
+{
+       workset->vals[idx].time = time;
+}
+
+static inline unsigned workset_get_length(const workset_t *workset)
+{
+       return workset->len;
+}
+
+static inline void workset_set_length(workset_t *workset, unsigned len)
+{
+       workset->len = len;
+}
+
+static inline ir_node *workset_get_val(const workset_t *workset, unsigned idx)
+{
+       return workset->vals[idx].node;
+}
+
 /**
  * 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].node)
-#define workset_sort(ws) qsort((ws)->vals, (ws)->len, sizeof((ws)->vals[0]), loc_compare);
-
-typedef struct _block_info_t
-{
+#define workset_foreach(ws, v, i) \
+       for (i=0; v=(i < ws->len) ? ws->vals[i].node : NULL, i < ws->len; ++i)
+
+typedef struct block_info_t {
        workset_t *start_workset;
        workset_t *end_workset;
 } block_info_t;
 
-
-static void *new_block_info(void)
+static block_info_t *new_block_info(void)
 {
-       block_info_t *res = obstack_alloc(&obst, sizeof(res[0]));
-       memset(res, 0, sizeof(res[0]));
+       return OALLOCZ(&obst, block_info_t);
+}
 
-       return res;
+static inline block_info_t *get_block_info(const ir_node *block)
+{
+       return (block_info_t*)get_irn_link(block);
 }
 
-#define get_block_info(block)        ((block_info_t *)get_irn_link(block))
-#define set_block_info(block, info)  set_irn_link(block, info)
+static inline void set_block_info(ir_node *block, block_info_t *info)
+{
+       set_irn_link(block, info);
+}
 
 /**
  * @return The distance to the next use or 0 if irn has dont_spill flag set
  */
-static INLINE unsigned get_distance(ir_node *from, unsigned from_step,
-                                    const ir_node *def, int skip_from_uses)
+static unsigned get_distance(ir_node *from, 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;
 
-       assert(! (flags & arch_irn_flags_ignore));
+       assert(!arch_irn_is_ignore(def));
 
-       use  = be_get_next_use(uses, from, from_step, def, skip_from_uses);
+       use  = be_get_next_use(uses, from, def, skip_from_uses);
        time = use.time;
        if (USES_IS_INFINITE(time))
                return USES_INFINITY;
 
        /* We have to keep nonspillable nodes in the workingset */
-       if (flags & arch_irn_flags_dont_spill)
+       if (arch_get_irn_flags(skip_Proj_const(def)) & arch_irn_flags_dont_spill)
                return 0;
 
        /* give some bonus to rematerialisable nodes */
@@ -322,24 +326,20 @@ static INLINE unsigned get_distance(ir_node *from, unsigned from_step,
  */
 static void displace(workset_t *new_vals, int is_usage)
 {
-       ir_node **to_insert = alloca(n_regs * sizeof(to_insert[0]));
-       bool     *spilled   = alloca(n_regs * sizeof(spilled[0]));
+       ir_node **to_insert = ALLOCAN(ir_node*, n_regs);
+       bool     *spilled   = ALLOCAN(bool,     n_regs);
        ir_node  *val;
        int       i;
        int       len;
        int       spills_needed;
        int       demand;
-       int       iter;
+       unsigned  iter;
 
        /* 1. Identify the number of needed slots and the values to reload */
        demand = 0;
        workset_foreach(new_vals, val, iter) {
                bool reloaded = false;
 
-               /* mark value as used */
-               if (is_usage)
-                       ir_nodeset_insert(&used, val);
-
                if (! workset_contains(ws, val)) {
                        DB((dbg, DBG_DECIDE, "    insert %+F\n", val));
                        if (is_usage) {
@@ -366,20 +366,12 @@ static void displace(workset_t *new_vals, int is_usage)
 
        /* Only make more free room if we do not have enough */
        if (spills_needed > 0) {
-               ir_node   *curr_bb  = NULL;
-               workset_t *ws_start = NULL;
-
-               if (move_spills) {
-                       curr_bb  = get_nodes_block(instr);
-                       ws_start = get_block_info(curr_bb)->start_workset;
-               }
-
                DB((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);
+                       unsigned  dist = get_distance(instr, val, !is_usage);
                        workset_set_time(ws, i, dist);
                }
 
@@ -400,14 +392,6 @@ static void displace(workset_t *new_vals, int is_usage)
                                                after_pos));
                                        be_add_spill(senv, val, after_pos);
                                }
-                       } else {
-                               /* Logic for not needed live-ins: If a value is disposed
-                                * before its first use, remove it from start workset
-                                * We don't do this for phis though     */
-                               if (!is_Phi(val) && ! ir_nodeset_contains(&used, val)) {
-                                       workset_remove(ws_start, val);
-                                       DB((dbg, DBG_DECIDE, "    (and removing %+F from start workset)\n", val));
-                               }
                        }
                }
 
@@ -498,21 +482,21 @@ static loc_t to_take_or_not_to_take(ir_node* first, ir_node *node,
        loc.node    = node;
        loc.spilled = false;
 
-       if (!arch_irn_consider_in_reg_alloc(arch_env, cls, node)) {
+       if (!arch_irn_consider_in_reg_alloc(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) {
+       if (arch_get_irn_flags(skip_Proj_const(node)) & arch_irn_flags_dont_spill) {
                loc.time = 0;
                DB((dbg, DBG_START, "    %+F taken (dontspill node)\n", node, loc.time));
                return loc;
        }
 
-       next_use = be_get_next_use(uses, first, 0, node, 0);
+       next_use = be_get_next_use(uses, first, 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
+               /* the nodes marked as live in shouldn't be dead, so it must be a phi */
                assert(is_Phi(node));
                loc.time = USES_INFINITY;
                DB((dbg, DBG_START, "    %+F not taken (dead)\n", node));
@@ -526,7 +510,7 @@ static loc_t to_take_or_not_to_take(ir_node* first, ir_node *node,
                        DB((dbg, DBG_START, "    %+F taken (%u, live in all preds)\n",
                            node, loc.time));
                        return loc;
-               } else if(available == AVAILABLE_NOWHERE) {
+               } else if (available == AVAILABLE_NOWHERE) {
                        DB((dbg, DBG_START, "    %+F not taken (%u, live in no pred)\n",
                            node, loc.time));
                        loc.time = USES_INFINITY;
@@ -556,12 +540,13 @@ static void decide_start_workset(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    len;
+       unsigned    i;
+       unsigned    ws_count;
+       int         free_slots, free_pressure_slots;
        unsigned    pressure;
        int         arity;
        workset_t **pred_worksets;
@@ -569,17 +554,17 @@ static void decide_start_workset(const ir_node *block)
 
        /* check predecessors */
        arity           = get_irn_arity(block);
-       pred_worksets   = alloca(sizeof(pred_worksets[0]) * arity);
+       pred_worksets   = ALLOCAN(workset_t*, arity);
        all_preds_known = true;
-       for(i = 0; i < arity; ++i) {
-               ir_node      *pred_block = get_Block_cfgpred_block(block, i);
+       for (int in = 0; in < arity; ++in) {
+               ir_node      *pred_block = get_Block_cfgpred_block(block, in);
                block_info_t *pred_info  = get_block_info(pred_block);
 
                if (pred_info == NULL) {
-                       pred_worksets[i] = NULL;
-                       all_preds_known  = false;
+                       pred_worksets[in] = NULL;
+                       all_preds_known   = false;
                } else {
-                       pred_worksets[i] = pred_info->end_workset;
+                       pred_worksets[in] = pred_info->end_workset;
                }
        }
 
@@ -596,7 +581,7 @@ static void decide_start_workset(const ir_node *block)
 
                if (! is_Phi(node))
                        break;
-               if (!arch_irn_consider_in_reg_alloc(arch_env, cls, node))
+               if (!arch_irn_consider_in_reg_alloc(cls, node))
                        continue;
 
                if (all_preds_known) {
@@ -618,10 +603,8 @@ static void decide_start_workset(const ir_node *block)
        }
 
        /* check all Live-Ins */
-       be_lv_foreach(lv, block, be_lv_state_in, i) {
-               ir_node *node = be_lv_get_irn(lv, block, i);
+       be_lv_foreach_cls(lv, block, be_lv_state_in, cls, node) {
                unsigned available;
-
                if (all_preds_known) {
                        available = available_in_all_preds(pred_worksets, arity, node, false);
                } else {
@@ -639,7 +622,7 @@ static void decide_start_workset(const ir_node *block)
        }
 
        pressure            = be_get_loop_pressure(loop_ana, cls, loop);
-       assert(ARR_LEN(delayed) <= (signed)pressure);
+       assert(ARR_LEN(delayed) <= 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);
@@ -650,27 +633,31 @@ static void decide_start_workset(const ir_node *block)
        DB((dbg, DBG_START, "Loop pressure %d, taking %d delayed vals\n",
            pressure, free_slots));
        if (free_slots > 0) {
+               size_t i;
+
                qsort(delayed, ARR_LEN(delayed), sizeof(delayed[0]), loc_compare);
 
                for (i = 0; i < ARR_LEN(delayed) && free_slots > 0; ++i) {
                        int    p, arity;
                        loc_t *loc = & delayed[i];
 
-                       /* don't use values which are dead in a known predecessors
-                        * to not induce unnecessary reloads */
-                       arity = get_irn_arity(block);
-                       for (p = 0; p < arity; ++p) {
-                               ir_node      *pred_block = get_Block_cfgpred_block(block, p);
-                               block_info_t *pred_info  = get_block_info(pred_block);
-
-                               if (pred_info == NULL)
-                                       continue;
-
-                               if (!workset_contains(pred_info->end_workset, loc->node)) {
-                                       DB((dbg, DBG_START,
-                                           "    delayed %+F not live at pred %+F\n", loc->node,
-                                           pred_block));
-                                       goto skip_delayed;
+                       if (!is_Phi(loc->node)) {
+                               /* don't use values which are dead in a known predecessors
+                                * to not induce unnecessary reloads */
+                               arity = get_irn_arity(block);
+                               for (p = 0; p < arity; ++p) {
+                                       ir_node      *pred_block = get_Block_cfgpred_block(block, p);
+                                       block_info_t *pred_info  = get_block_info(pred_block);
+
+                                       if (pred_info == NULL)
+                                               continue;
+
+                                       if (!workset_contains(pred_info->end_workset, loc->node)) {
+                                               DB((dbg, DBG_START,
+                                                       "    delayed %+F not live at pred %+F\n", loc->node,
+                                                       pred_block));
+                                               goto skip_delayed;
+                                       }
                                }
                        }
 
@@ -685,7 +672,8 @@ static void decide_start_workset(const ir_node *block)
 
        /* 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) {
+       len = ARR_LEN(delayed);
+       for (i = 0; i < len; ++i) {
                ir_node *node = delayed[i].node;
                if (node == NULL || !is_Phi(node) || get_nodes_block(node) != block)
                        continue;
@@ -699,7 +687,7 @@ static void decide_start_workset(const ir_node *block)
        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);
+       ws_count = MIN((unsigned) ARR_LEN(starters), n_regs);
        workset_clear(ws);
        workset_bulk_fill(ws, ws_count, starters);
 
@@ -720,7 +708,7 @@ static void decide_start_workset(const ir_node *block)
        /* determine spill status of the values: If there's 1 pred block (which
         * is no backedge) where the value is spilled then we must set it to
         * spilled here. */
-       for(i = 0; i < ws_count; ++i) {
+       for (i = 0; i < ws_count; ++i) {
                loc_t   *loc     = &ws->vals[i];
                ir_node *value   = loc->node;
                bool     spilled;
@@ -735,7 +723,7 @@ static void decide_start_workset(const ir_node *block)
 
                /* determine if value was spilled on any predecessor */
                spilled = false;
-               for(n = 0; n < arity; ++n) {
+               for (n = 0; n < arity; ++n) {
                        workset_t *pred_workset = pred_worksets[n];
                        int        p_len;
                        int        p;
@@ -744,7 +732,7 @@ static void decide_start_workset(const ir_node *block)
                                continue;
 
                        p_len = workset_get_length(pred_workset);
-                       for(p = 0; p < p_len; ++p) {
+                       for (p = 0; p < p_len; ++p) {
                                loc_t *l = &pred_workset->vals[p];
 
                                if (l->node != value)
@@ -766,50 +754,30 @@ static void decide_start_workset(const ir_node *block)
  * whether it is used from a register or is reloaded
  * before the use.
  */
-static void belady(ir_node *block)
+static void process_block(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;
+       workset_t    *new_vals;
+       unsigned      iter;
+       block_info_t *block_info;
+       int           arity;
 
        /* no need to process a block twice */
-       if (get_block_info(block) != NULL) {
-               return;
-       }
+       assert(get_block_info(block) == NULL);
 
-       /* check if all predecessor blocks are processed yet (though for backedges
-        * we have to make an exception as we can't process them first) */
+       /* construct start workset */
        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) {
+               /* no predecessor -> empty set */
                workset_clear(ws);
        } else if (arity == 1) {
+               /* one predecessor, copy its end workset */
                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) */
+               /* multiple predecessors, do more advanced magic :) */
                decide_start_workset(block);
        }
 
@@ -820,22 +788,21 @@ static void belady(ir_node *block)
        set_block_info(block, block_info);
 
        DB((dbg, DBG_WSETS, "Start workset for %+F:\n", block));
-       workset_foreach(ws, irn, iter) {
-               DB((dbg, DBG_WSETS, "  %+F (%u)\n", irn,
-                    workset_get_time(ws, iter)));
+       {
+               ir_node *irn;
+               workset_foreach(ws, irn, iter) {
+                       DB((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 */
        DB((dbg, DBG_WSETS, "Processing...\n"));
-       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()) */
@@ -849,49 +816,28 @@ static void belady(ir_node *block)
 
                /* allocate all values _used_ by this instruction */
                workset_clear(new_vals);
-               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;
-
+               be_foreach_use(irn, cls, in_req_, in, in_req,
                        /* (note that "spilled" is irrelevant here) */
                        workset_insert(new_vals, in, false);
-               }
+               );
                displace(new_vals, 1);
 
                /* allocate all values _defined_ by this instruction */
                workset_clear(new_vals);
-               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, false);
-                       }
-               } else {
-                       if (!arch_irn_consider_in_reg_alloc(arch_env, cls, irn))
-                               continue;
-                       workset_insert(new_vals, irn, false);
-               }
+               be_foreach_definition(irn, cls, value,
+                       assert(req_->width == 1);
+                       workset_insert(new_vals, value, false);
+               );
                displace(new_vals, 0);
-
-               instr_nr++;
        }
-       ir_nodeset_destroy(&used);
 
        /* Remember end-workset for this block */
        block_info->end_workset = workset_clone(ws);
        DB((dbg, DBG_WSETS, "End workset for %+F:\n", block));
-       workset_foreach(ws, irn, iter)
-               DB((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);
+       {
+               ir_node *irn;
+               workset_foreach(ws, irn, iter)
+                       DB((dbg, DBG_WSETS, "  %+F (%u)\n", irn, workset_get_time(ws, iter)));
        }
 }
 
@@ -902,19 +848,23 @@ static void belady(ir_node *block)
  */
 static void fix_block_borders(ir_node *block, void *data)
 {
-       workset_t    *start_workset;
-       int           arity;
-       int           i;
-       int           iter;
+       workset_t *start_workset;
+       int        arity;
+       int        i;
+       unsigned   iter;
        (void) data;
 
        DB((dbg, DBG_FIX, "\n"));
        DB((dbg, DBG_FIX, "Fixing %+F\n", block));
 
+       arity = get_irn_arity(block);
+       /* can happen for endless loops */
+       if (arity == 0)
+               return;
+
        start_workset = get_block_info(block)->start_workset;
 
        /* process all pred blocks */
-       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;
@@ -925,7 +875,7 @@ static void fix_block_borders(ir_node *block, void *data)
                /* spill all values not used anymore */
                workset_foreach(pred_end_workset, node, iter) {
                        ir_node *n2;
-                       int      iter2;
+                       unsigned iter2;
                        bool     found = false;
                        workset_foreach(start_workset, n2, iter2) {
                                if (n2 == node) {
@@ -968,7 +918,7 @@ static void fix_block_borders(ir_node *block, void *data)
                                assert(!l->spilled);
 
                                /* we might have unknowns as argument for the phi */
-                               if (!arch_irn_consider_in_reg_alloc(arch_env, cls, node))
+                               if (!arch_irn_consider_in_reg_alloc(cls, node))
                                        continue;
                        }
 
@@ -994,45 +944,50 @@ static void fix_block_borders(ir_node *block, void *data)
        }
 }
 
-static void be_spill_belady(be_irg_t *birg, const arch_register_class_t *rcls)
+static void be_spill_belady(ir_graph *irg, const arch_register_class_t *rcls)
 {
-       ir_graph *irg = be_get_birg_irg(birg);
+       int i;
 
-       be_liveness_assure_sets(be_assure_liveness(birg));
+       be_assure_live_sets(irg);
 
-       /* construct control flow loop tree */
-       if (! (get_irg_loopinfo_state(irg) & loopinfo_cf_consistent)) {
-               construct_cf_backedges(irg);
-       }
+       stat_ev_tim_push();
+       assure_loopinfo(irg);
+       stat_ev_tim_pop("belady_time_backedges");
 
+       stat_ev_tim_push();
        be_clear_links(irg);
+       stat_ev_tim_pop("belady_time_clear_links");
+
+       ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
 
        /* init belady env */
+       stat_ev_tim_push();
        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);
+       cls       = rcls;
+       lv        = be_get_irg_liveness(irg);
+       n_regs    = be_get_n_allocatable_regs(irg, cls);
+       ws        = new_workset();
+       uses      = be_begin_uses(irg, lv);
+       loop_ana  = be_new_loop_pressure(irg, cls);
+       senv      = be_new_spill_env(irg);
+       blocklist = be_get_cfgpostorder(irg);
+       stat_ev_tim_pop("belady_time_init");
+
+       stat_ev_tim_push();
+       /* walk blocks in reverse postorder */
+       for (i = ARR_LEN(blocklist) - 1; i >= 0; --i) {
+               process_block(blocklist[i]);
        }
-       /* end block might not be reachable in endless loops */
-       belady(get_irg_end_block(irg));
-
-       del_pdeq(worklist);
+       DEL_ARR_F(blocklist);
+       stat_ev_tim_pop("belady_time_belady");
 
+       stat_ev_tim_push();
        /* belady was block-local, fix the global flow by adding reloads on the
         * edges */
        irg_block_walk_graph(irg, fix_block_borders, NULL, NULL);
+       stat_ev_tim_pop("belady_time_fix_borders");
+
+       ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
 
        /* Insert spill/reload nodes into the graph and fix usages */
        be_insert_spills_reloads(senv);
@@ -1044,6 +999,7 @@ static void be_spill_belady(be_irg_t *birg, const arch_register_class_t *rcls)
        obstack_free(&obst, NULL);
 }
 
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spillbelady)
 void be_init_spillbelady(void)
 {
        static be_spiller_t belady_spiller = {
@@ -1056,5 +1012,3 @@ void be_init_spillbelady(void)
        be_register_spiller("belady", &belady_spiller);
        FIRM_DBG_REGISTER(dbg, "firm.be.spill.belady");
 }
-
-BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spillbelady);