handle Block_entity like other node attributes
[libfirm] / ir / opt / combo.c
index 59d494a..ad88f5a 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.
  *
@@ -21,7 +21,6 @@
  * @file
  * @brief   Cliff Click's Combined Analysis/Optimization
  * @author  Michael Beck
- * @version $Id$
  *
  * This is a slightly enhanced version of Cliff Clicks combo algorithm
  * - support for commutative nodes is added, Add(a,b) and Add(b,a) ARE congruent
@@ -63,7 +62,6 @@
 #include <assert.h>
 
 #include "iroptimize.h"
-#include "archop.h"
 #include "irflag.h"
 #include "ircons.h"
 #include "list.h"
 #include "debug.h"
 #include "array_t.h"
 #include "error.h"
-
+#include "irnodeset.h"
+#include "irpass.h"
 #include "tv_t.h"
+#include "irtools.h"
+#include "opt_manage.h"
 
 #include "irprintf.h"
 #include "irdump.h"
@@ -93,9 +94,6 @@
 /* define this to check the consistency of partitions */
 #define CHECK_PARTITIONS
 
-/* allow optimization of non-strict programs */
-#define WITH_UNKNOWN
-
 typedef struct node_t            node_t;
 typedef struct partition_t       partition_t;
 typedef struct opcode_key_t      opcode_key_t;
@@ -108,13 +106,7 @@ typedef void (*compute_func)(node_t *node);
  * An opcode map key.
  */
 struct opcode_key_t {
-       ir_opcode   code;   /**< The Firm opcode. */
-       ir_mode     *mode;  /**< The mode of all nodes in the partition. */
-       int         arity;  /**< The arity of this opcode (needed for Phi etc. */
-       union {
-               long      proj;   /**< For Proj nodes, its proj number */
-               ir_entity *ent;   /**< For Sel Nodes, its entity */
-       } u;
+       ir_node *irn;    /**< An IR node representing this opcode. */
 };
 
 /**
@@ -137,7 +129,7 @@ typedef struct listmap_t {
  * have to use this union.
  */
 typedef union {
-       tarval          *tv;
+       ir_tarval      *tv;
        symconst_symbol sym;
 } lattice_elem_t;
 
@@ -195,12 +187,14 @@ typedef struct environment_t {
        partition_t     *touched;       /**< the touched set. */
        partition_t     *initial;       /**< The initial partition. */
        set             *opcode2id_map; /**< The opcodeMode->id map. */
-       pmap            *type2id_map;   /**< The type->id map. */
+       ir_node         **kept_memory;  /**< Array of memory nodes that must be kept. */
        int             end_idx;        /**< -1 for local and 0 for global congruences. */
        int             lambda_input;   /**< Captured argument for lambda_partition(). */
        unsigned        modified:1;     /**< Set, if the graph was modified. */
-       unsigned        commutative:1;  /**< Set, if commutation nodes should be handled specially. */
        unsigned        unopt_cf:1;     /**< If set, control flow is not optimized due to Unknown. */
+       /* options driving the optimization */
+       unsigned        commutative:1;  /**< Set, if commutation nodes should be handled specially. */
+       unsigned        opt_unknown:1;  /**< Set, if non-strict programs should be optimized. */
 #ifdef DEBUG_libfirm
        partition_t     *dbg_list;      /**< List of all partitions. */
 #endif
@@ -209,8 +203,8 @@ typedef struct environment_t {
 /** Type of the what function. */
 typedef void *(*what_func)(const node_t *node, environment_t *env);
 
-#define get_irn_node(follower)         ((node_t *)get_irn_link(follower))
-#define set_irn_node(follower, node)   set_irn_link(follower, node)
+#define get_irn_node(irn)         ((node_t *)get_irn_link(irn))
+#define set_irn_node(irn, node)   set_irn_link(irn, node)
 
 /* we do NOT use tarval_unreachable here, instead we use Top for this purpose */
 #undef tarval_unreachable
@@ -224,23 +218,56 @@ DEBUG_ONLY(static firm_dbg_module_t *dbg;)
 DEBUG_ONLY(static const char *what_reason;)
 
 /** Next partition number. */
-DEBUG_ONLY(static unsigned part_nr = 0);
+DEBUG_ONLY(static unsigned part_nr = 0;)
 
-/** The tarval returned by Unknown nodes. */
-#ifdef WITH_UNKNOWN
-#define tarval_UNKNOWN tarval_top
-#else
-#define tarval_UNKNOWN tarval_bad
-#endif
+/** The tarval returned by Unknown nodes: set to either tarval_bad OR tarval_top. */
+static ir_tarval *tarval_UNKNOWN;
 
 /* forward */
 static node_t *identity(node_t *node);
 
+/**
+ * Compare two opcode representatives.
+ */
+static int cmp_irn_opcode(const ir_node *a, const ir_node *b)
+{
+       int arity;
+
+       if ((get_irn_op(a) != get_irn_op(b)) ||
+           (get_irn_mode(a) != get_irn_mode(b)))
+               return 1;
+
+       /* compare if a's in and b's in are of equal length */
+       arity = get_irn_arity(a);
+       if (arity != get_irn_arity(b))
+               return 1;
+
+       if (is_Block(a)) {
+               /*
+                * Some ugliness here: Two Blocks having the same
+                * IJmp predecessor would be congruent, which of course is wrong.
+                * We fix it by never letting blocks be congruent
+                * which cannot be detected by combo either.
+                */
+               return 1;
+       }
+
+       /*
+        * here, we already know that the nodes are identical except their
+        * attributes
+        */
+       if (a->op->ops.node_cmp_attr)
+               return a->op->ops.node_cmp_attr(a, b);
+
+       return 0;
+}  /* cmp_irn_opcode */
+
 #ifdef CHECK_PARTITIONS
 /**
  * Check a partition.
  */
-static void check_partition(const partition_t *T) {
+static void check_partition(const partition_t *T)
+{
        node_t   *node;
        unsigned n = 0;
 
@@ -262,52 +289,24 @@ static void check_partition(const partition_t *T) {
 /**
  * check that all leader nodes in the partition have the same opcode.
  */
-static void check_opcode(const partition_t *Z) {
-       node_t       *node;
-       opcode_key_t key;
-       int          first = 1;
+static void check_opcode(const partition_t *Z)
+{
+       node_t        *node;
+       const ir_node *repr = NULL;
 
        list_for_each_entry(node_t, node, &Z->Leader, node_list) {
                ir_node *irn = node->node;
 
-               if (first) {
-                       key.code   = get_irn_opcode(irn);
-                       key.mode   = get_irn_mode(irn);
-                       key.arity  = get_irn_arity(irn);
-                       key.u.proj = 0;
-                       key.u.ent  = NULL;
-
-                       switch (get_irn_opcode(irn)) {
-                       case iro_Proj:
-                               key.u.proj = get_Proj_proj(irn);
-                               break;
-                       case iro_Sel:
-                               key.u.ent = get_Sel_entity(irn);
-                               break;
-                       default:
-                               break;
-                       }
-                       first = 0;
+               if (repr == NULL) {
+                       repr = irn;
                } else {
-                       assert(key.code  == get_irn_opcode(irn));
-                       assert(key.mode  == get_irn_mode(irn));
-                       assert(key.arity == get_irn_arity(irn));
-
-                       switch (get_irn_opcode(irn)) {
-                       case iro_Proj:
-                               assert(key.u.proj == get_Proj_proj(irn));
-                               break;
-                       case iro_Sel:
-                               assert(key.u.ent == get_Sel_entity(irn));
-                               break;
-                       default:
-                               break;
-                       }
+                       assert(cmp_irn_opcode(repr, irn) == 0);
                }
        }
 }  /* check_opcode */
 
-static void check_all_partitions(environment_t *env) {
+static void check_all_partitions(environment_t *env)
+{
 #ifdef DEBUG_libfirm
        partition_t *P;
        node_t      *node;
@@ -322,26 +321,36 @@ static void check_all_partitions(environment_t *env) {
                        assert(leader != node && leader->part == node->part);
                }
        }
+#else
+       (void) env;
 #endif
 }
 
 /**
  * Check list.
  */
-static void do_check_list(const node_t *list, int ofs, const partition_t *Z) {
-       const node_t *e;
+static void do_check_list(const node_t *list, int ofs, const partition_t *Z)
+{
 
+#ifndef NDEBUG
+       const node_t *e;
 #define NEXT(e)  *((const node_t **)((char *)(e) + (ofs)))
        for (e = list; e != NULL; e = NEXT(e)) {
                assert(e->part == Z);
        }
 #undef NEXT
+#else
+       (void) list;
+       (void) ofs;
+       (void) Z;
+#endif
 }  /* ido_check_list */
 
 /**
  * Check a local list.
  */
-static void check_list(const node_t *list, const partition_t *Z) {
+static void check_list(const node_t *list, const partition_t *Z)
+{
        do_check_list(list, offsetof(node_t, next), Z);
 }  /* check_list */
 
@@ -357,7 +366,8 @@ static inline lattice_elem_t get_partition_type(const partition_t *X);
 /**
  * Dump partition to output.
  */
-static void dump_partition(const char *msg, const partition_t *part) {
+static void dump_partition(const char *msg, const partition_t *part)
+{
        const node_t   *node;
        int            first = 1;
        lattice_elem_t type = get_partition_type(part);
@@ -383,7 +393,8 @@ static void dump_partition(const char *msg, const partition_t *part) {
 /**
  * Dumps a list.
  */
-static void do_dump_list(const char *msg, const node_t *node, int ofs) {
+static void do_dump_list(const char *msg, const node_t *node, int ofs)
+{
        const node_t *p;
        int          first = 1;
 
@@ -402,21 +413,24 @@ static void do_dump_list(const char *msg, const node_t *node, int ofs) {
 /**
  * Dumps a race list.
  */
-static void dump_race_list(const char *msg, const node_t *list) {
+static void dump_race_list(const char *msg, const node_t *list)
+{
        do_dump_list(msg, list, offsetof(node_t, race_next));
 }  /* dump_race_list */
 
 /**
  * Dumps a local list.
  */
-static void dump_list(const char *msg, const node_t *list) {
+static void dump_list(const char *msg, const node_t *list)
+{
        do_dump_list(msg, list, offsetof(node_t, next));
 }  /* dump_list */
 
 /**
  * Dump all partitions.
  */
-static void dump_all_partitions(const environment_t *env) {
+static void dump_all_partitions(const environment_t *env)
+{
        const partition_t *P;
 
        DB((dbg, LEVEL_2, "All partitions\n===============\n"));
@@ -427,7 +441,8 @@ static void dump_all_partitions(const environment_t *env) {
 /**
  * Sump a split list.
  */
-static void dump_split_list(const partition_t *list) {
+static void dump_split_list(const partition_t *list)
+{
        const partition_t *p;
 
        DB((dbg, LEVEL_2, "Split by %s produced = {\n", what_reason));
@@ -439,7 +454,8 @@ static void dump_split_list(const partition_t *list) {
 /**
  * Dump partition and type for a node.
  */
-static int dump_partition_hook(FILE *F, ir_node *n, ir_node *local) {
+static int dump_partition_hook(FILE *F, ir_node *n, ir_node *local)
+{
        ir_node *irn = local != NULL ? local : n;
        node_t *node = get_irn_node(irn);
 
@@ -459,7 +475,8 @@ static int dump_partition_hook(FILE *F, ir_node *n, ir_node *local) {
 /**
  * Verify that a type transition is monotone
  */
-static void verify_type(const lattice_elem_t old_type, node_t *node) {
+static void verify_type(const lattice_elem_t old_type, node_t *node)
+{
        if (old_type.tv == node->type.tv) {
                /* no change */
                return;
@@ -482,9 +499,10 @@ static void verify_type(const lattice_elem_t old_type, node_t *node) {
 /**
  * Compare two pointer values of a listmap.
  */
-static int listmap_cmp_ptr(const void *elt, const void *key, size_t size) {
-       const listmap_entry_t *e1 = elt;
-       const listmap_entry_t *e2 = key;
+static int listmap_cmp_ptr(const void *elt, const void *key, size_t size)
+{
+       const listmap_entry_t *e1 = (listmap_entry_t*)elt;
+       const listmap_entry_t *e2 = (listmap_entry_t*)key;
 
        (void) size;
        return e1->id != e2->id;
@@ -495,7 +513,8 @@ static int listmap_cmp_ptr(const void *elt, const void *key, size_t size) {
  *
  * @param map  the listmap
  */
-static void listmap_init(listmap_t *map) {
+static void listmap_init(listmap_t *map)
+{
        map->map    = new_set(listmap_cmp_ptr, 16);
        map->values = NULL;
 }  /* listmap_init */
@@ -505,7 +524,8 @@ static void listmap_init(listmap_t *map) {
  *
  * @param map  the listmap
  */
-static void listmap_term(listmap_t *map) {
+static void listmap_term(listmap_t *map)
+{
        del_set(map->map);
 }  /* listmap_term */
 
@@ -517,13 +537,14 @@ static void listmap_term(listmap_t *map) {
  *
  * @return the associated listmap entry for the given id
  */
-static listmap_entry_t *listmap_find(listmap_t *map, void *id) {
+static listmap_entry_t *listmap_find(listmap_t *map, void *id)
+{
        listmap_entry_t key, *entry;
 
        key.id   = id;
        key.list = NULL;
        key.next = NULL;
-       entry = set_insert(map->map, &key, sizeof(key), HASH_PTR(id));
+       entry = (listmap_entry_t*)set_insert(map->map, &key, sizeof(key), HASH_PTR(id));
 
        if (entry->list == NULL) {
                /* a new entry, put into the list */
@@ -540,29 +561,42 @@ static listmap_entry_t *listmap_find(listmap_t *map, void *id) {
  *
  * @return a hash value for the given opcode map entry
  */
-static unsigned opcode_hash(const opcode_key_t *entry) {
-       return (entry->mode - (ir_mode *)0) * 9 + entry->code + entry->u.proj * 3 + HASH_PTR(entry->u.ent) + entry->arity;
+static unsigned opcode_hash(const opcode_key_t *entry)
+{
+       /* we cannot use the ir ops hash function here, because it hashes the
+        * predecessors. */
+       const ir_node *n = entry->irn;
+       ir_opcode code  = get_irn_opcode(n);
+       ir_mode   *mode = get_irn_mode(n);
+       unsigned hash = (unsigned)(PTR_TO_INT(mode) * 9 + code) + get_irn_arity(n);
+
+       if (code == iro_Const)
+               hash ^= (unsigned)HASH_PTR(get_Const_tarval(n));
+       else if (code == iro_Proj)
+               hash += (unsigned)get_Proj_proj(n);
+       return hash;
 }  /* opcode_hash */
 
 /**
  * Compare two entries in the opcode map.
  */
-static int cmp_opcode(const void *elt, const void *key, size_t size) {
-       const opcode_key_t *o1 = elt;
-       const opcode_key_t *o2 = key;
+static int cmp_opcode(const void *elt, const void *key, size_t size)
+{
+       const opcode_key_t *o1 = (opcode_key_t*)elt;
+       const opcode_key_t *o2 = (opcode_key_t*)key;
 
        (void) size;
-       return o1->code != o2->code || o1->mode != o2->mode ||
-              o1->arity != o2->arity ||
-              o1->u.proj != o2->u.proj || o1->u.ent != o2->u.ent;
+
+       return cmp_irn_opcode(o1->irn, o2->irn);
 }  /* cmp_opcode */
 
 /**
  * Compare two Def-Use edges for input position.
  */
-static int cmp_def_use_edge(const void *a, const void *b) {
-       const ir_def_use_edge *ea = a;
-       const ir_def_use_edge *eb = b;
+static int cmp_def_use_edge(const void *a, const void *b)
+{
+       const ir_def_use_edge *ea = (const ir_def_use_edge*)a;
+       const ir_def_use_edge *eb = (const ir_def_use_edge*)b;
 
        /* no overrun, because range is [-1, MAXINT] */
        return ea->pos - eb->pos;
@@ -571,7 +605,8 @@ static int cmp_def_use_edge(const void *a, const void *b) {
 /**
  * We need the Def-Use edges sorted.
  */
-static void sort_irn_outs(node_t *node) {
+static void sort_irn_outs(node_t *node)
+{
        ir_node *irn = node->node;
        int n_outs = get_irn_n_outs(irn);
 
@@ -588,7 +623,8 @@ static void sort_irn_outs(node_t *node) {
  *
  * @return the associated type of this node
  */
-static inline lattice_elem_t get_node_type(const ir_node *irn) {
+static inline lattice_elem_t get_node_type(const ir_node *irn)
+{
        return get_irn_node(irn)->type;
 }  /* get_node_type */
 
@@ -599,7 +635,8 @@ static inline lattice_elem_t get_node_type(const ir_node *irn) {
  *
  * @return the associated type of this node
  */
-static inline tarval *get_node_tarval(const ir_node *irn) {
+static inline ir_tarval *get_node_tarval(const ir_node *irn)
+{
        lattice_elem_t type = get_node_type(irn);
 
        if (is_tarval(type.tv))
@@ -610,7 +647,8 @@ static inline tarval *get_node_tarval(const ir_node *irn) {
 /**
  * Add a partition to the worklist.
  */
-static inline void add_to_worklist(partition_t *X, environment_t *env) {
+static inline void add_to_worklist(partition_t *X, environment_t *env)
+{
        assert(X->on_worklist == 0);
        DB((dbg, LEVEL_2, "Adding part%d to worklist\n", X->nr));
        X->wl_next     = env->worklist;
@@ -625,8 +663,9 @@ static inline void add_to_worklist(partition_t *X, environment_t *env) {
  *
  * @return a newly allocated partition
  */
-static inline partition_t *new_partition(environment_t *env) {
-       partition_t *part = obstack_alloc(&env->obst, sizeof(*part));
+static inline partition_t *new_partition(environment_t *env)
+{
+       partition_t *part = OALLOC(&env->obst, partition_t);
 
        INIT_LIST_HEAD(&part->Leader);
        INIT_LIST_HEAD(&part->Follower);
@@ -656,7 +695,8 @@ static inline partition_t *new_partition(environment_t *env) {
 /**
  * Get the first node from a partition.
  */
-static inline node_t *get_first_node(const partition_t *X) {
+static inline node_t *get_first_node(const partition_t *X)
+{
        return list_entry(X->Leader.next, node_t, node_list);
 }  /* get_first_node */
 
@@ -668,7 +708,8 @@ static inline node_t *get_first_node(const partition_t *X) {
  *
  * @return the type of the first element of the partition
  */
-static inline lattice_elem_t get_partition_type(const partition_t *X) {
+static inline lattice_elem_t get_partition_type(const partition_t *X)
+{
        const node_t *first = get_first_node(X);
        return first->type;
 }  /* get_partition_type */
@@ -683,9 +724,10 @@ static inline lattice_elem_t get_partition_type(const partition_t *X) {
  *
  * @return the created node
  */
-static node_t *create_partition_node(ir_node *irn, partition_t *part, environment_t *env) {
+static node_t *create_partition_node(ir_node *irn, partition_t *part, environment_t *env)
+{
        /* create a partition node and place it in the partition */
-       node_t *node = obstack_alloc(&env->obst, sizeof(*node));
+       node_t *node = OALLOC(&env->obst, node_t);
 
        INIT_LIST_HEAD(&node->node_list);
        INIT_LIST_HEAD(&node->cprop_list);
@@ -714,8 +756,9 @@ static node_t *create_partition_node(ir_node *irn, partition_t *part, environmen
  * Pre-Walker, initialize all Nodes' type to U or top and place
  * all nodes into the TOP partition.
  */
-static void create_initial_partitions(ir_node *irn, void *ctx) {
-       environment_t *env  = ctx;
+static void create_initial_partitions(ir_node *irn, void *ctx)
+{
+       environment_t *env  = (environment_t*)ctx;
        partition_t   *part = env->initial;
        node_t        *node;
 
@@ -732,11 +775,13 @@ static void create_initial_partitions(ir_node *irn, void *ctx) {
 /**
  * Post-Walker, collect  all Block-Phi lists, set Cond.
  */
-static void init_block_phis(ir_node *irn, void *ctx) {
+static void init_block_phis(ir_node *irn, void *ctx)
+{
        (void) ctx;
 
        if (is_Phi(irn)) {
-               add_Block_phi(get_nodes_block(irn), irn);
+               ir_node *block = get_nodes_block(irn);
+               add_Block_phi(block, irn);
        }
 }  /* init_block_phis */
 
@@ -747,7 +792,8 @@ static void init_block_phis(ir_node *irn, void *ctx) {
  * @param y    a node
  * @param env  the environment
  */
-static inline void add_to_touched(node_t *y, environment_t *env) {
+static inline void add_to_touched(node_t *y, environment_t *env)
+{
        if (y->on_touched == 0) {
                partition_t *part = y->part;
 
@@ -772,16 +818,18 @@ static inline void add_to_touched(node_t *y, environment_t *env) {
  * @param y    the node
  * @param env  the environment
  */
-static void add_to_cprop(node_t *y, environment_t *env) {
+static void add_to_cprop(node_t *y, environment_t *env)
+{
        ir_node *irn;
 
        /* Add y to y.partition.cprop. */
        if (y->on_cprop == 0) {
                partition_t *Y = y->part;
                ir_node *irn   = y->node;
+               ir_node *skipped = skip_Proj(irn);
 
                /* place Conds and all its Projs on the cprop_X list */
-               if (is_Cond(skip_Proj(irn)))
+               if (is_Cond(skipped) || is_Switch(skipped))
                        list_add_tail(&y->cprop_list, &Y->cprop_X);
                else
                        list_add_tail(&y->cprop_list, &Y->cprop);
@@ -799,7 +847,7 @@ static void add_to_cprop(node_t *y, environment_t *env) {
        irn = y->node;
        if (get_irn_mode(irn) == mode_T) {
                /* mode_T nodes always produce tarval_bottom, so we must explicitly
-                  add it's Proj's to get constant evaluation to work */
+                * add its Projs to get constant evaluation to work */
                int i;
 
                for (i = get_irn_n_outs(irn) - 1; i >= 0; --i) {
@@ -827,7 +875,8 @@ static void add_to_cprop(node_t *y, environment_t *env) {
  * @param Z_prime  the Z' partition, a previous part of Z
  * @param env      the environment
  */
-static void update_worklist(partition_t *Z, partition_t *Z_prime, environment_t *env) {
+static void update_worklist(partition_t *Z, partition_t *Z_prime, environment_t *env)
+{
        if (Z->on_worklist || Z_prime->n_leader < Z->n_leader) {
                add_to_worklist(Z_prime, env);
        } else {
@@ -840,7 +889,8 @@ static void update_worklist(partition_t *Z, partition_t *Z_prime, environment_t
  *
  * @param x  the node
  */
-static void move_edges_to_leader(node_t *x) {
+static void move_edges_to_leader(node_t *x)
+{
        ir_node     *irn = x->node;
        int         i, j, k;
 
@@ -885,7 +935,8 @@ static void move_edges_to_leader(node_t *x) {
  *
  * @return  a new partition containing the nodes of g
  */
-static partition_t *split_no_followers(partition_t *Z, node_t *g, environment_t *env) {
+static partition_t *split_no_followers(partition_t *Z, node_t *g, environment_t *env)
+{
        partition_t *Z_prime;
        node_t      *node;
        unsigned    n = 0;
@@ -935,7 +986,8 @@ static partition_t *split_no_followers(partition_t *Z, node_t *g, environment_t
  *
  * @param n  the node
  */
-static void follower_to_leader(node_t *n) {
+static void follower_to_leader(node_t *n)
+{
        assert(n->is_follower == 1);
 
        DB((dbg, LEVEL_2, "%+F make the follower -> leader transition\n", n->node));
@@ -963,7 +1015,8 @@ typedef struct step_env {
  * @param irn    the node to check
  * @param input  number of the input
  */
-static int is_real_follower(const ir_node *irn, int input) {
+static int is_real_follower(const ir_node *irn, int input)
+{
        node_t *pred;
 
        switch (get_irn_opcode(irn)) {
@@ -1015,10 +1068,6 @@ static int is_real_follower(const ir_node *irn, int input) {
                if (is_tarval(pred->type.tv) && tarval_is_all_one(pred->type.tv))
                        return 0;
                break;
-       case iro_Min:
-       case iro_Max:
-               /* all inputs are followers */
-               return 1;
        default:
                assert(!"opcode not implemented yet");
                break;
@@ -1029,7 +1078,8 @@ static int is_real_follower(const ir_node *irn, int input) {
 /**
  * Do one step in the race.
  */
-static int step(step_env *env) {
+static int step(step_env *env)
+{
        node_t *n;
 
        if (env->initial != NULL) {
@@ -1096,7 +1146,8 @@ static int step(step_env *env) {
  *
  * @param list  the list
  */
-static int clear_flags(node_t *list) {
+static int clear_flags(node_t *list)
+{
        int    res = 0;
        node_t *n;
 
@@ -1121,7 +1172,8 @@ static int clear_flags(node_t *list) {
  *
  * @return  a new partition containing the nodes of gg
  */
-static partition_t *split(partition_t **pX, node_t *gg, environment_t *env) {
+static partition_t *split(partition_t **pX, node_t *gg, environment_t *env)
+{
        partition_t *X = *pX;
        partition_t *X_prime;
        list_head   tmp;
@@ -1294,7 +1346,8 @@ static partition_t *split(partition_t **pX, node_t *gg, environment_t *env) {
  *
  * @return non-zero if the i'th input of the given Phi node is live
  */
-static int is_live_input(ir_node *phi, int i) {
+static int is_live_input(ir_node *phi, int i)
+{
        if (i >= 0) {
                ir_node        *block = get_nodes_block(phi);
                ir_node        *pred  = get_Block_cfgpred(block, i);
@@ -1309,7 +1362,8 @@ static int is_live_input(ir_node *phi, int i) {
 /**
  * Return non-zero if a type is a constant.
  */
-static int is_constant_type(lattice_elem_t type) {
+static int is_constant_type(lattice_elem_t type)
+{
        if (type.tv != tarval_bottom && type.tv != tarval_top)
                return 1;
        return 0;
@@ -1321,7 +1375,8 @@ static int is_constant_type(lattice_elem_t type) {
  *
  * @param type  the type to check
  */
-static int type_is_neither_top_nor_const(const lattice_elem_t type) {
+static int type_is_neither_top_nor_const(const lattice_elem_t type)
+{
        if (is_tarval(type.tv)) {
                if (type.tv == tarval_top)
                        return 0;
@@ -1341,7 +1396,8 @@ static int type_is_neither_top_nor_const(const lattice_elem_t type) {
  * @param idx   the index of the def_use edge to evaluate
  * @param env   the environment
  */
-static void collect_touched(list_head *list, int idx, environment_t *env) {
+static void collect_touched(list_head *list, int idx, environment_t *env)
+{
        node_t  *x, *y;
        int     end_idx = env->end_idx;
 
@@ -1385,7 +1441,7 @@ static void collect_touched(list_head *list, int idx, environment_t *env) {
                                continue;
 
                        if (is_constant_type(y->type)) {
-                               ir_opcode code = get_irn_opcode(succ);
+                               unsigned  code = get_irn_opcode(succ);
                                if (code == iro_Sub || code == iro_Cmp)
                                        add_to_cprop(y, env);
                        }
@@ -1406,7 +1462,8 @@ static void collect_touched(list_head *list, int idx, environment_t *env) {
  * @param list  the list which contains the nodes that must be evaluated
  * @param env   the environment
  */
-static void collect_commutative_touched(list_head *list, environment_t *env) {
+static void collect_commutative_touched(list_head *list, environment_t *env)
+{
        node_t  *x, *y;
 
        list_for_each_entry(node_t, x, list, node_list) {
@@ -1437,7 +1494,7 @@ static void collect_commutative_touched(list_head *list, environment_t *env) {
 
                        y = get_irn_node(succ);
                        if (is_constant_type(y->type)) {
-                               ir_opcode code = get_irn_opcode(succ);
+                               unsigned code = get_irn_opcode(succ);
                                if (code == iro_Eor)
                                        add_to_cprop(y, env);
                        }
@@ -1456,7 +1513,8 @@ static void collect_commutative_touched(list_head *list, environment_t *env) {
  *
  * @param env  the environment
  */
-static void cause_splits(environment_t *env) {
+static void cause_splits(environment_t *env)
+{
        partition_t *X, *Z, *N;
        int         idx;
 
@@ -1477,9 +1535,12 @@ static void cause_splits(environment_t *env) {
                collect_commutative_touched(&X->Follower, env);
 
                for (Z = env->touched; Z != NULL; Z = N) {
-                       node_t   *e;
-                       node_t   *touched  = Z->touched;
-                       unsigned n_touched = Z->n_touched;
+                       node_t   *e, *n;
+                       node_t   *touched     = Z->touched;
+                       node_t   *touched_aa  = NULL;
+                       node_t   *touched_ab  = NULL;
+                       unsigned n_touched_aa = 0;
+                       unsigned n_touched_ab = 0;
 
                        assert(Z->touched != NULL);
 
@@ -1490,18 +1551,45 @@ static void cause_splits(environment_t *env) {
                        Z->on_touched = 0;
 
                        /* Empty local Z.touched. */
-                       for (e = touched; e != NULL; e = e->next) {
+                       for (e = touched; e != NULL; e = n) {
+                               node_t *left  = get_irn_node(get_irn_n(e->node, 0));
+                               node_t *right = get_irn_node(get_irn_n(e->node, 1));
+
                                assert(e->is_follower == 0);
                                e->on_touched = 0;
+                               n = e->next;
+
+                               /*
+                                * Note: op(a, a) is NOT congruent to op(a, b).
+                                * So, we must split the touched list.
+                                */
+                               if (left->part == right->part) {
+                                       e->next = touched_aa;
+                                       touched_aa = e;
+                                       ++n_touched_aa;
+                               } else {
+                                       e->next = touched_ab;
+                                       touched_ab = e;
+                                       ++n_touched_ab;
+                               }
                        }
+                       assert(n_touched_aa + n_touched_ab == Z->n_touched);
                        Z->touched   = NULL;
                        Z->n_touched = 0;
 
-                       if (0 < n_touched && n_touched < Z->n_leader) {
-                               DB((dbg, LEVEL_2, "Split part%d by touched\n", Z->nr));
-                               split(&Z, touched, env);
+                       if (0 < n_touched_aa && n_touched_aa < Z->n_leader) {
+                               partition_t *Z_prime = Z;
+                               DB((dbg, LEVEL_2, "Split part%d by touched_aa\n", Z_prime->nr));
+                               split(&Z_prime, touched_aa, env);
                        } else
-                               assert(n_touched <= Z->n_leader);
+                               assert(n_touched_aa <= Z->n_leader);
+
+                       if (0 < n_touched_ab && n_touched_ab < Z->n_leader) {
+                               partition_t *Z_prime = Z;
+                               DB((dbg, LEVEL_2, "Split part%d by touched_ab\n", Z_prime->nr));
+                               split(&Z_prime, touched_ab, env);
+                       } else
+                               assert(n_touched_ab <= Z->n_leader);
                }
        }
 
@@ -1555,7 +1643,8 @@ static void cause_splits(environment_t *env) {
  * @return *P
  */
 static partition_t *split_by_what(partition_t *X, what_func What,
-                                  partition_t **P, environment_t *env) {
+                                  partition_t **P, environment_t *env)
+{
        node_t          *x, *S;
        listmap_t       map;
        listmap_entry_t *iter;
@@ -1601,39 +1690,26 @@ static partition_t *split_by_what(partition_t *X, what_func What,
 }  /* split_by_what */
 
 /** lambda n.(n.type) */
-static void *lambda_type(const node_t *node, environment_t *env) {
+static void *lambda_type(const node_t *node, environment_t *env)
+{
        (void)env;
        return node->type.tv;
 }  /* lambda_type */
 
 /** lambda n.(n.opcode) */
-static void *lambda_opcode(const node_t *node, environment_t *env) {
+static void *lambda_opcode(const node_t *node, environment_t *env)
+{
        opcode_key_t key, *entry;
-       ir_node      *irn = node->node;
-
-       key.code   = get_irn_opcode(irn);
-       key.mode   = get_irn_mode(irn);
-       key.arity  = get_irn_arity(irn);
-       key.u.proj = 0;
-       key.u.ent  = NULL;
 
-       switch (get_irn_opcode(irn)) {
-       case iro_Proj:
-               key.u.proj = get_Proj_proj(irn);
-               break;
-       case iro_Sel:
-               key.u.ent = get_Sel_entity(irn);
-               break;
-       default:
-               break;
-       }
+       key.irn = node->node;
 
-       entry = set_insert(env->opcode2id_map, &key, sizeof(key), opcode_hash(&key));
+       entry = (opcode_key_t*)set_insert(env->opcode2id_map, &key, sizeof(key), opcode_hash(&key));
        return entry;
 }  /* lambda_opcode */
 
 /** lambda n.(n[i].partition) */
-static void *lambda_partition(const node_t *node, environment_t *env) {
+static void *lambda_partition(const node_t *node, environment_t *env)
+{
        ir_node *skipped = skip_Proj(node->node);
        ir_node *pred;
        node_t  *p;
@@ -1657,12 +1733,12 @@ static void *lambda_partition(const node_t *node, environment_t *env) {
 
        pred = i == -1 ? get_irn_n(skipped, i) : get_irn_n(node->node, i);
        p    = get_irn_node(pred);
-
        return p->part;
 }  /* lambda_partition */
 
 /** lambda n.(n[i].partition) for commutative nodes */
-static void *lambda_commutative_partition(const node_t *node, environment_t *env) {
+static void *lambda_commutative_partition(const node_t *node, environment_t *env)
+{
        ir_node     *irn     = node->node;
        ir_node     *skipped = skip_Proj(irn);
        ir_node     *pred, *left, *right;
@@ -1717,7 +1793,8 @@ static void *lambda_commutative_partition(const node_t *node, environment_t *env
  * Returns true if a type is a constant (and NOT Top
  * or Bottom).
  */
-static int is_con(const lattice_elem_t type) {
+static int is_con(const lattice_elem_t type)
+{
        /* be conservative */
        if (is_tarval(type.tv))
                return tarval_is_constant(type.tv);
@@ -1730,14 +1807,15 @@ static int is_con(const lattice_elem_t type) {
  * @param X    the partition to split
  * @param env  the environment
  */
-static void split_by(partition_t *X, environment_t *env) {
+static void split_by(partition_t *X, environment_t *env)
+{
        partition_t *I, *P = NULL;
        int         input;
 
        dump_partition("split_by", X);
 
        if (X->n_leader == 1) {
-               /* we have only one leader, no need to split, just check it's type */
+               /* we have only one leader, no need to split, just check its type */
                node_t *x = get_first_node(X);
                X->type_is_T_or_C = x->type.tv == tarval_top || is_con(x->type);
                return;
@@ -1819,15 +1897,10 @@ static void split_by(partition_t *X, environment_t *env) {
  *
  * @param node  the node
  */
-static void default_compute(node_t *node) {
+static void default_compute(node_t *node)
+{
        int     i;
        ir_node *irn = node->node;
-       node_t  *block = get_irn_node(get_nodes_block(irn));
-
-       if (block->type.tv == tarval_unreachable) {
-               node->type.tv = tarval_top;
-               return;
-       }
 
        /* if any of the data inputs have type top, the result is type top */
        for (i = get_irn_arity(irn) - 1; i >= 0; --i) {
@@ -1851,12 +1924,13 @@ static void default_compute(node_t *node) {
  *
  * @param node  the node
  */
-static void compute_Block(node_t *node) {
+static void compute_Block(node_t *node)
+{
        int     i;
        ir_node *block = node->node;
 
-       if (block == get_irg_start_block(current_ir_graph)) {
-               /* start block is always reachable */
+       if (block == get_irg_start_block(current_ir_graph) || get_Block_entity(block) != NULL) {
+               /* start block and labelled blocks are always reachable */
                node->type.tv = tarval_reachable;
                return;
        }
@@ -1878,7 +1952,8 @@ static void compute_Block(node_t *node) {
  *
  * @param node  the node
  */
-static void compute_Bad(node_t *node) {
+static void compute_Bad(node_t *node)
+{
        /* Bad nodes ALWAYS compute Top */
        node->type.tv = tarval_top;
 }  /* compute_Bad */
@@ -1888,7 +1963,8 @@ static void compute_Bad(node_t *node) {
  *
  * @param node  the node
  */
-static void compute_Unknown(node_t *node) {
+static void compute_Unknown(node_t *node)
+{
        /* While Unknown nodes should compute Top this is dangerous:
         * a Top input to a Cond would lead to BOTH control flows unreachable.
         * While this is correct in the given semantics, it would destroy the Firm
@@ -1897,7 +1973,7 @@ static void compute_Unknown(node_t *node) {
         * It would be safe to compute Top IF it can be assured, that only Cmp
         * nodes are inputs to Conds. We check that first.
         * This is the way Frontends typically build Firm, but some optimizations
-        * (cond_eval for instance) might replace them by Phib's...
+        * (jump threading for instance) might replace them by Phib's...
         */
        node->type.tv = tarval_UNKNOWN;
 }  /* compute_Unknown */
@@ -1907,7 +1983,8 @@ static void compute_Unknown(node_t *node) {
  *
  * @param node  the node
  */
-static void compute_Jmp(node_t *node) {
+static void compute_Jmp(node_t *node)
+{
        node_t *block = get_irn_node(get_nodes_block(node->node));
 
        node->type = block->type;
@@ -1918,7 +1995,8 @@ static void compute_Jmp(node_t *node) {
  *
  * @param node  the node
  */
-static void compute_Return(node_t *node) {
+static void compute_Return(node_t *node)
+{
        /* The Return node is NOT dead if it is in a reachable block.
         * This is already checked in compute(). so we can return
         * Reachable here. */
@@ -1930,7 +2008,8 @@ static void compute_Return(node_t *node) {
  *
  * @param node  the node
  */
-static void compute_End(node_t *node) {
+static void compute_End(node_t *node)
+{
        /* the End node is NOT dead of course */
        node->type.tv = tarval_reachable;
 }  /* compute_End */
@@ -1940,7 +2019,8 @@ static void compute_End(node_t *node) {
  *
  * @param node  the node
  */
-static void compute_Call(node_t *node) {
+static void compute_Call(node_t *node)
+{
        /*
         * A Call computes always bottom, even if it has Unknown
         * predecessors.
@@ -1953,7 +2033,8 @@ static void compute_Call(node_t *node) {
  *
  * @param node  the node
  */
-static void compute_SymConst(node_t *node) {
+static void compute_SymConst(node_t *node)
+{
        ir_node *irn = node->node;
        node_t  *block = get_irn_node(get_nodes_block(irn));
 
@@ -1963,7 +2044,6 @@ static void compute_SymConst(node_t *node) {
        }
        switch (get_SymConst_kind(irn)) {
        case symconst_addr_ent:
-       /* case symconst_addr_name: cannot handle this yet */
                node->type.sym = get_SymConst_symbol(irn);
                break;
        default:
@@ -1976,7 +2056,8 @@ static void compute_SymConst(node_t *node) {
  *
  * @param node  the node
  */
-static void compute_Phi(node_t *node) {
+static void compute_Phi(node_t *node)
+{
        int            i;
        ir_node        *phi = node->node;
        lattice_elem_t type;
@@ -2023,7 +2104,8 @@ static void compute_Phi(node_t *node) {
  *
  * @param node  the node
  */
-static void compute_Add(node_t *node) {
+static void compute_Add(node_t *node)
+{
        ir_node        *sub = node->node;
        node_t         *l   = get_irn_node(get_Add_left(sub));
        node_t         *r   = get_irn_node(get_Add_right(sub));
@@ -2064,13 +2146,14 @@ static void compute_Add(node_t *node) {
  *
  * @param node  the node
  */
-static void compute_Sub(node_t *node) {
+static void compute_Sub(node_t *node)
+{
        ir_node        *sub = node->node;
        node_t         *l   = get_irn_node(get_Sub_left(sub));
        node_t         *r   = get_irn_node(get_Sub_right(sub));
        lattice_elem_t a    = l->type;
        lattice_elem_t b    = r->type;
-       tarval         *tv;
+       ir_tarval      *tv;
 
        if (a.tv == tarval_top || b.tv == tarval_top) {
                node->type.tv = tarval_top;
@@ -2110,13 +2193,14 @@ static void compute_Sub(node_t *node) {
  *
  * @param node  the node
  */
-static void compute_Eor(node_t *node) {
+static void compute_Eor(node_t *node)
+{
        ir_node        *eor = node->node;
        node_t         *l   = get_irn_node(get_Eor_left(eor));
        node_t         *r   = get_irn_node(get_Eor_right(eor));
        lattice_elem_t a    = l->type;
        lattice_elem_t b    = r->type;
-       tarval         *tv;
+       ir_tarval      *tv;
 
        if (a.tv == tarval_top || b.tv == tarval_top) {
                node->type.tv = tarval_top;
@@ -2151,64 +2235,43 @@ static void compute_Eor(node_t *node) {
  *
  * @param node  the node
  */
-static void compute_Cmp(node_t *node) {
-       ir_node        *cmp  = node->node;
-       node_t         *l    = get_irn_node(get_Cmp_left(cmp));
-       node_t         *r    = get_irn_node(get_Cmp_right(cmp));
-       lattice_elem_t a     = l->type;
-       lattice_elem_t b     = r->type;
-
-       if (a.tv == tarval_top || b.tv == tarval_top) {
-               node->type.tv = tarval_top;
-       } else if (r->part == l->part) {
-               /* both nodes congruent, we can probably do something */
-               node->type.tv = tarval_b_true;
-       } else if (is_con(a) && is_con(b)) {
-               /* both nodes are constants, we can probably do something */
-               node->type.tv = tarval_b_true;
-       } else {
-               node->type.tv = tarval_bottom;
-       }
-}  /* compute_Cmp */
-
-/**
- * (Re-)compute the type for a Proj(Cmp).
- *
- * @param node  the node
- * @param cond  the predecessor Cmp node
- */
-static void compute_Proj_Cmp(node_t *node, ir_node *cmp) {
-       ir_node        *proj = node->node;
-       node_t         *l    = get_irn_node(get_Cmp_left(cmp));
-       node_t         *r    = get_irn_node(get_Cmp_right(cmp));
-       lattice_elem_t a     = l->type;
-       lattice_elem_t b     = r->type;
-       pn_Cmp         pnc   = get_Proj_proj(proj);
-       tarval         *tv;
+static void compute_Cmp(node_t *node)
+{
+       ir_node        *cmp     = node->node;
+       node_t         *l       = get_irn_node(get_Cmp_left(cmp));
+       node_t         *r       = get_irn_node(get_Cmp_right(cmp));
+       lattice_elem_t a        = l->type;
+       lattice_elem_t b        = r->type;
+       ir_relation    relation = get_Cmp_relation(cmp);
+       ir_tarval      *tv;
 
        if (a.tv == tarval_top || b.tv == tarval_top) {
                node->type.tv = tarval_undefined;
        } else if (is_con(a) && is_con(b)) {
                default_compute(node);
-       } else if (r->part == l->part &&
-                  (!mode_is_float(get_irn_mode(l->node)) || pnc == pn_Cmp_Lt || pnc == pn_Cmp_Gt)) {
-               /*
-                * BEWARE: a == a is NOT always True for floating Point values, as
-                * NaN != NaN is defined, so we must check this here.
-                */
-               tv = pnc & pn_Cmp_Eq ? tarval_b_true: tarval_b_false;
 
-               /* if the node was ONCE evaluated by all constants, but now
+       /*
+        * BEWARE: a == a is NOT always True for floating Point values, as
+        * NaN != NaN is defined, so we must check this here.
+        * (while for some pnc we could still optimize we have to stay
+        *  consistent with compute_Cmp, so don't do anything for floats)
+        */
+       } else if (r->part == l->part && !mode_is_float(get_irn_mode(l->node))) {
+               tv = relation & ir_relation_equal ? tarval_b_true : tarval_b_false;
+
+               /* if the node was ONCE evaluated to a constant, but now
                   this breaks AND we get from the argument partitions a different
-                  result, switch to bottom.
+                  result, ensure monotony by fall to bottom.
                   This happens because initially all nodes are in the same partition ... */
-               if (node->type.tv != tv)
+               if (node->type.tv == tarval_bottom)
+                       tv = tarval_bottom;
+               else if (node->type.tv != tv && is_constant_type(node->type))
                        tv = tarval_bottom;
                node->type.tv = tv;
        } else {
                node->type.tv = tarval_bottom;
        }
-}  /* compute_Proj_Cmp */
+}
 
 /**
  * (Re-)compute the type for a Proj(Cond).
@@ -2216,7 +2279,8 @@ static void compute_Proj_Cmp(node_t *node, ir_node *cmp) {
  * @param node  the node
  * @param cond  the predecessor Cond node
  */
-static void compute_Proj_Cond(node_t *node, ir_node *cond) {
+static void compute_Proj_Cond(node_t *node, ir_node *cond)
+{
        ir_node *proj     = node->node;
        long    pnc       = get_Proj_proj(proj);
        ir_node *sel      = get_Cond_selector(cond);
@@ -2274,89 +2338,105 @@ static void compute_Proj_Cond(node_t *node, ir_node *cond) {
        if (node->type.tv == tarval_reachable)
                return;
 
-       if (get_irn_mode(sel) == mode_b) {
-               /* an IF */
-               if (pnc == pn_Cond_true) {
-                       if (selector->type.tv == tarval_b_false) {
-                               node->type.tv = tarval_unreachable;
-                       } else if (selector->type.tv == tarval_b_true) {
-                               node->type.tv = tarval_reachable;
-                       } else if (selector->type.tv == tarval_bottom) {
-                               node->type.tv = tarval_reachable;
-                       } else {
-                               assert(selector->type.tv == tarval_top);
-#ifdef WITH_UNKNOWN
+       if (pnc == pn_Cond_true) {
+               if (selector->type.tv == tarval_b_false) {
+                       node->type.tv = tarval_unreachable;
+               } else if (selector->type.tv == tarval_b_true) {
+                       node->type.tv = tarval_reachable;
+               } else if (selector->type.tv == tarval_bottom) {
+                       node->type.tv = tarval_reachable;
+               } else {
+                       assert(selector->type.tv == tarval_top);
+                       if (tarval_UNKNOWN == tarval_top) {
                                /* any condition based on Top is "!=" */
                                node->type.tv = tarval_unreachable;
-#else
+                       } else {
                                node->type.tv = tarval_unreachable;
-#endif
                        }
-               } else {
-                       assert(pnc == pn_Cond_false);
+               }
+       } else {
+               assert(pnc == pn_Cond_false);
 
-                       if (selector->type.tv == tarval_b_false) {
-                               node->type.tv = tarval_reachable;
-                       } else if (selector->type.tv == tarval_b_true) {
-                               node->type.tv = tarval_unreachable;
-                       } else if (selector->type.tv == tarval_bottom) {
-                               node->type.tv = tarval_reachable;
-                       } else {
-                               assert(selector->type.tv == tarval_top);
-#ifdef WITH_UNKNOWN
+               if (selector->type.tv == tarval_b_false) {
+                       node->type.tv = tarval_reachable;
+               } else if (selector->type.tv == tarval_b_true) {
+                       node->type.tv = tarval_unreachable;
+               } else if (selector->type.tv == tarval_bottom) {
+                       node->type.tv = tarval_reachable;
+               } else {
+                       assert(selector->type.tv == tarval_top);
+                       if (tarval_UNKNOWN == tarval_top) {
                                /* any condition based on Top is "!=" */
                                node->type.tv = tarval_reachable;
-#else
+                       } else {
                                node->type.tv = tarval_unreachable;
-#endif
                        }
                }
-       } else {
-               /* an SWITCH */
-               if (selector->type.tv == tarval_bottom) {
+       }
+}  /* compute_Proj_Cond */
+
+static void compute_Proj_Switch(node_t *node, ir_node *switchn)
+{
+       ir_node *proj     = node->node;
+       long     pnc      = get_Proj_proj(proj);
+       ir_node *sel      = get_Switch_selector(switchn);
+       node_t  *selector = get_irn_node(sel);
+
+       /* see long comment in compute_Proj_Cond */
+       if (node->type.tv == tarval_reachable)
+               return;
+
+       if (selector->type.tv == tarval_bottom) {
+               node->type.tv = tarval_reachable;
+       } else if (selector->type.tv == tarval_top) {
+               if (tarval_UNKNOWN == tarval_top && pnc == pn_Switch_default) {
+                       /* a switch based of Top is always "default" */
                        node->type.tv = tarval_reachable;
-               } else if (selector->type.tv == tarval_top) {
-#ifdef WITH_UNKNOWN
-                       if (pnc == get_Cond_defaultProj(cond)) {
-                               /* a switch based of Top is always "default" */
-                               node->type.tv = tarval_reachable;
-                       } else
-#endif
-                               node->type.tv = tarval_unreachable;
                } else {
-                       long value = get_tarval_long(selector->type.tv);
-                       if (pnc == get_Cond_defaultProj(cond)) {
-                               /* default switch, have to check ALL other cases */
-                               int i;
-
-                               for (i = get_irn_n_outs(cond) - 1; i >= 0; --i) {
-                                       ir_node *succ = get_irn_out(cond, i);
-
-                                       if (succ == proj)
-                                               continue;
-                                       if (value == get_Proj_proj(succ)) {
-                                               /* we found a match, will NOT take the default case */
-                                               node->type.tv = tarval_unreachable;
-                                               return;
-                                       }
+                       node->type.tv = tarval_unreachable;
+               }
+       } else {
+               long                   value = get_tarval_long(selector->type.tv);
+               const ir_switch_table *table = get_Switch_table(switchn);
+               size_t                 n_entries = ir_switch_table_get_n_entries(table);
+               size_t                 e;
+
+               for (e = 0; e < n_entries; ++e) {
+                       const ir_switch_table_entry *entry
+                               = ir_switch_table_get_entry_const(table, e);
+                       ir_tarval *min = entry->min;
+                       ir_tarval *max = entry->max;
+                       if (min == max) {
+                               if (selector->type.tv == min) {
+                                       node->type.tv = entry->pn == pnc
+                                               ? tarval_reachable : tarval_unreachable;
+                                       return;
                                }
-                               /* all cases checked, no match, will take default case */
-                               node->type.tv = tarval_reachable;
                        } else {
-                               /* normal case */
-                               node->type.tv = value == pnc ? tarval_reachable : tarval_unreachable;
+                               long minval = get_tarval_long(min);
+                               long maxval = get_tarval_long(max);
+                               if (minval <= value && value <= maxval) {
+                                       node->type.tv = entry->pn == pnc
+                                               ? tarval_reachable : tarval_unreachable;
+                                       return;
+                               }
                        }
                }
+
+               /* no entry matched: default */
+               node->type.tv
+                       = pnc == pn_Switch_default ? tarval_reachable : tarval_unreachable;
        }
-}  /* compute_Proj_Cond */
+}
 
 /**
- * (Re-)compute the type for a Proj-Node.
- *
- * @param node  the node
- */
-static void compute_Proj(node_t *node) {
-       ir_node *proj = node->node;
+* (Re-)compute the type for a Proj-Node.
+*
+* @param node  the node
+*/
+static void compute_Proj(node_t *node)
+{
+ir_node *proj = node->node;
        ir_mode *mode = get_irn_mode(proj);
        node_t  *block = get_irn_node(get_nodes_block(skip_Proj(proj)));
        ir_node *pred  = get_Proj_pred(proj);
@@ -2366,7 +2446,7 @@ static void compute_Proj(node_t *node) {
                node->type.tv = tarval_top;
                return;
        }
-       if (get_irn_node(pred)->type.tv == tarval_top && !is_Cond(pred)) {
+       if (get_irn_node(pred)->type.tv == tarval_top && !is_Cond(pred) && !is_Switch(pred)) {
                /* if the predecessor is Top, its Proj follow */
                node->type.tv = tarval_top;
                return;
@@ -2376,28 +2456,26 @@ static void compute_Proj(node_t *node) {
                /* mode M is always bottom */
                node->type.tv = tarval_bottom;
                return;
+       } else if (mode == mode_X) {
+               /* handle mode_X nodes */
+               switch (get_irn_opcode(pred)) {
+               case iro_Start:
+                       /* the Proj_X from the Start is always reachable.
+                          However this is already handled at the top. */
+                       node->type.tv = tarval_reachable;
+                       return;
+               case iro_Cond:
+                       compute_Proj_Cond(node, pred);
+                       return;
+               case iro_Switch:
+                       compute_Proj_Switch(node, pred);
+                       return;
+               default:
+                       break;
+               }
        }
-       if (mode != mode_X) {
-               if (is_Cmp(pred))
-                       compute_Proj_Cmp(node, pred);
-               else
-                       default_compute(node);
-               return;
-       }
-       /* handle mode_X nodes */
 
-       switch (get_irn_opcode(pred)) {
-       case iro_Start:
-               /* the Proj_X from the Start is always reachable.
-                  However this is already handled at the top. */
-               node->type.tv = tarval_reachable;
-               break;
-       case iro_Cond:
-               compute_Proj_Cond(node, pred);
-               break;
-       default:
-               default_compute(node);
-       }
+       default_compute(node);
 }  /* compute_Proj */
 
 /**
@@ -2405,11 +2483,12 @@ static void compute_Proj(node_t *node) {
  *
  * @param node  the node
  */
-static void compute_Confirm(node_t *node) {
+static void compute_Confirm(node_t *node)
+{
        ir_node *confirm = node->node;
        node_t  *pred = get_irn_node(get_Confirm_value(confirm));
 
-       if (get_Confirm_cmp(confirm) == pn_Cmp_Eq) {
+       if (get_Confirm_relation(confirm) == ir_relation_equal) {
                node_t *bound = get_irn_node(get_Confirm_bound(confirm));
 
                if (is_con(bound->type)) {
@@ -2422,100 +2501,13 @@ static void compute_Confirm(node_t *node) {
        node->type = pred->type;
 }  /* compute_Confirm */
 
-/**
- * (Re-)compute the type for a Max.
- *
- * @param node  the node
- */
-static void compute_Max(node_t *node) {
-       ir_node        *op = node->node;
-       node_t         *l  = get_irn_node(get_binop_left(op));
-       node_t         *r  = get_irn_node(get_binop_right(op));
-       lattice_elem_t a   = l->type;
-       lattice_elem_t b   = r->type;
-
-       if (a.tv == tarval_top || b.tv == tarval_top) {
-               node->type.tv = tarval_top;
-       } else if (is_con(a) && is_con(b)) {
-               /* both nodes are constants, we can probably do something */
-               if (a.tv == b.tv) {
-                       /* this case handles SymConsts as well */
-                       node->type = a;
-               } else {
-                       ir_mode *mode   = get_irn_mode(op);
-                       tarval  *tv_min = get_mode_min(mode);
-
-                       if (a.tv == tv_min)
-                               node->type = b;
-                       else if (b.tv == tv_min)
-                               node->type = a;
-                       else if (is_tarval(a.tv) && is_tarval(b.tv)) {
-                               if (tarval_cmp(a.tv, b.tv) & pn_Cmp_Gt)
-                                       node->type.tv = a.tv;
-                               else
-                                       node->type.tv = b.tv;
-                       } else {
-                               node->type.tv = tarval_bad;
-                       }
-               }
-       } else if (r->part == l->part) {
-               /* both nodes congruent, we can probably do something */
-               node->type = a;
-       } else {
-               node->type.tv = tarval_bottom;
-       }
-}  /* compute_Max */
-
-/**
- * (Re-)compute the type for a Min.
- *
- * @param node  the node
- */
-static void compute_Min(node_t *node) {
-       ir_node        *op = node->node;
-       node_t         *l  = get_irn_node(get_binop_left(op));
-       node_t         *r  = get_irn_node(get_binop_right(op));
-       lattice_elem_t a   = l->type;
-       lattice_elem_t b   = r->type;
-
-       if (a.tv == tarval_top || b.tv == tarval_top) {
-               node->type.tv = tarval_top;
-       } else if (is_con(a) && is_con(b)) {
-               /* both nodes are constants, we can probably do something */
-               if (a.tv == b.tv) {
-                       /* this case handles SymConsts as well */
-                       node->type = a;
-               } else {
-                       ir_mode *mode   = get_irn_mode(op);
-                       tarval  *tv_max = get_mode_max(mode);
-
-                       if (a.tv == tv_max)
-                               node->type = b;
-                       else if (b.tv == tv_max)
-                               node->type = a;
-                       else if (is_tarval(a.tv) && is_tarval(b.tv)) {
-                               if (tarval_cmp(a.tv, b.tv) & pn_Cmp_Gt)
-                                       node->type.tv = a.tv;
-                               else
-                                       node->type.tv = b.tv;
-                       } else {
-                               node->type.tv = tarval_bad;
-                       }
-               }
-       } else if (r->part == l->part) {
-               /* both nodes congruent, we can probably do something */
-               node->type = a;
-       } else {
-               node->type.tv = tarval_bottom;
-       }
-}  /* compute_Min */
-
 /**
  * (Re-)compute the type for a given node.
  *
  * @param node  the node
  */
-static void compute(node_t *node) {
+static void compute(node_t *node)
+{
        ir_node *irn = node->node;
        compute_func func;
 
@@ -2529,7 +2521,8 @@ static void compute(node_t *node) {
        if (node->type.tv == tarval_bottom)
                return;
 #endif
-       if (is_no_Block(irn)) {
+
+       if (!is_Block(irn)) {
                /* for pinned nodes, check its control input */
                if (get_irn_pinned(skip_Proj(irn)) == op_pin_state_pinned) {
                        node_t *block = get_irn_node(get_nodes_block(irn));
@@ -2547,7 +2540,7 @@ static void compute(node_t *node) {
 }  /* compute */
 
 /*
- * Identity functions: Note that one might thing that identity() is just a
+ * Identity functions: Note that one might think that identity() is just a
  * synonym for equivalent_node(). While this is true, we cannot use it for the algorithm
  * here, because it expects that the identity node is one of the inputs, which is NOT
  * always true for equivalent_node() which can handle (and does sometimes) DAGs.
@@ -2557,7 +2550,8 @@ static void compute(node_t *node) {
 /**
  * Calculates the Identity for Phi nodes
  */
-static node_t *identity_Phi(node_t *node) {
+static node_t *identity_Phi(node_t *node)
+{
        ir_node *phi    = node->node;
        ir_node *block  = get_nodes_block(phi);
        node_t  *n_part = NULL;
@@ -2586,12 +2580,13 @@ static node_t *identity_Phi(node_t *node) {
 /**
  * Calculates the Identity for commutative 0 neutral nodes.
  */
-static node_t *identity_comm_zero_binop(node_t *node) {
-       ir_node *op   = node->node;
-       node_t  *a    = get_irn_node(get_binop_left(op));
-       node_t  *b    = get_irn_node(get_binop_right(op));
-       ir_mode *mode = get_irn_mode(op);
-       tarval  *zero;
+static node_t *identity_comm_zero_binop(node_t *node)
+{
+       ir_node   *op   = node->node;
+       node_t    *a    = get_irn_node(get_binop_left(op));
+       node_t    *b    = get_irn_node(get_binop_right(op));
+       ir_mode   *mode = get_irn_mode(op);
+       ir_tarval *zero;
 
        /* for FP these optimizations are only allowed if fp_strict_algebraic is disabled */
        if (mode_is_float(mode) && (get_irg_fp_model(current_ir_graph) & fp_strict_algebraic))
@@ -2610,11 +2605,12 @@ static node_t *identity_comm_zero_binop(node_t *node) {
 /**
  * Calculates the Identity for Shift nodes.
  */
-static node_t *identity_shift(node_t *node) {
-       ir_node *op   = node->node;
-       node_t  *b    = get_irn_node(get_binop_right(op));
-       ir_mode *mode = get_irn_mode(b->node);
-       tarval  *zero;
+static node_t *identity_shift(node_t *node)
+{
+       ir_node   *op   = node->node;
+       node_t    *b    = get_irn_node(get_binop_right(op));
+       ir_mode   *mode = get_irn_mode(b->node);
+       ir_tarval *zero;
 
        /* node: no input should be tarval_top, else the binop would be also
         * Top and not being split. */
@@ -2627,12 +2623,13 @@ static node_t *identity_shift(node_t *node) {
 /**
  * Calculates the Identity for Mul nodes.
  */
-static node_t *identity_Mul(node_t *node) {
-       ir_node *op   = node->node;
-       node_t  *a    = get_irn_node(get_Mul_left(op));
-       node_t  *b    = get_irn_node(get_Mul_right(op));
-       ir_mode *mode = get_irn_mode(op);
-       tarval  *one;
+static node_t *identity_Mul(node_t *node)
+{
+       ir_node   *op   = node->node;
+       node_t    *a    = get_irn_node(get_Mul_left(op));
+       node_t    *b    = get_irn_node(get_Mul_right(op));
+       ir_mode   *mode = get_irn_mode(op);
+       ir_tarval *one;
 
        /* for FP these optimizations are only allowed if fp_strict_algebraic is disabled */
        if (mode_is_float(mode) && (get_irg_fp_model(current_ir_graph) & fp_strict_algebraic))
@@ -2651,7 +2648,8 @@ static node_t *identity_Mul(node_t *node) {
 /**
  * Calculates the Identity for Sub nodes.
  */
-static node_t *identity_Sub(node_t *node) {
+static node_t *identity_Sub(node_t *node)
+{
        ir_node *sub  = node->node;
        node_t  *b    = get_irn_node(get_Sub_right(sub));
        ir_mode *mode = get_irn_mode(sub);
@@ -2670,11 +2668,12 @@ static node_t *identity_Sub(node_t *node) {
 /**
  * Calculates the Identity for And nodes.
  */
-static node_t *identity_And(node_t *node) {
-       ir_node *and = node->node;
-       node_t  *a   = get_irn_node(get_And_left(and));
-       node_t  *b   = get_irn_node(get_And_right(and));
-       tarval  *neutral = get_mode_all_one(get_irn_mode(and));
+static node_t *identity_And(node_t *node)
+{
+       ir_node   *andnode = node->node;
+       node_t    *a       = get_irn_node(get_And_left(andnode));
+       node_t    *b       = get_irn_node(get_And_right(andnode));
+       ir_tarval *neutral = get_mode_all_one(get_irn_mode(andnode));
 
        /* node: no input should be tarval_top, else the And would be also
         * Top and not being split. */
@@ -2688,7 +2687,8 @@ static node_t *identity_And(node_t *node) {
 /**
  * Calculates the Identity for Confirm nodes.
  */
-static node_t *identity_Confirm(node_t *node) {
+static node_t *identity_Confirm(node_t *node)
+{
        ir_node *confirm = node->node;
 
        /* a Confirm is always a Copy */
@@ -2698,7 +2698,8 @@ static node_t *identity_Confirm(node_t *node) {
 /**
  * Calculates the Identity for Mux nodes.
  */
-static node_t *identity_Mux(node_t *node) {
+static node_t *identity_Mux(node_t *node)
+{
        ir_node *mux = node->node;
        node_t  *t   = get_irn_node(get_Mux_true(mux));
        node_t  *f   = get_irn_node(get_Mux_false(mux));
@@ -2720,58 +2721,11 @@ static node_t *identity_Mux(node_t *node) {
        return node;
 }  /* identity_Mux */
 
-/**
- * Calculates the Identity for Min nodes.
- */
-static node_t *identity_Min(node_t *node) {
-       ir_node *op   = node->node;
-       node_t  *a    = get_irn_node(get_binop_left(op));
-       node_t  *b    = get_irn_node(get_binop_right(op));
-       ir_mode *mode = get_irn_mode(op);
-       tarval  *tv_max;
-
-       if (a->part == b->part) {
-               /* leader of multiple predecessors */
-               return a;
-       }
-
-       /* works even with NaN */
-       tv_max = get_mode_max(mode);
-       if (a->type.tv == tv_max)
-               return b;
-       if (b->type.tv == tv_max)
-               return a;
-       return node;
-}  /* identity_Min */
-
-/**
- * Calculates the Identity for Max nodes.
- */
-static node_t *identity_Max(node_t *node) {
-       ir_node *op   = node->node;
-       node_t  *a    = get_irn_node(get_binop_left(op));
-       node_t  *b    = get_irn_node(get_binop_right(op));
-       ir_mode *mode = get_irn_mode(op);
-       tarval  *tv_min;
-
-       if (a->part == b->part) {
-               /* leader of multiple predecessors */
-               return a;
-       }
-
-       /* works even with NaN */
-       tv_min = get_mode_min(mode);
-       if (a->type.tv == tv_min)
-               return b;
-       if (b->type.tv == tv_min)
-               return a;
-       return node;
-}  /* identity_Max */
-
 /**
  * Calculates the Identity for nodes.
  */
-static node_t *identity(node_t *node) {
+static node_t *identity(node_t *node)
+{
        ir_node *irn = node->node;
 
        switch (get_irn_opcode(irn)) {
@@ -2796,10 +2750,6 @@ static node_t *identity(node_t *node) {
                return identity_Confirm(node);
        case iro_Mux:
                return identity_Mux(node);
-       case iro_Min:
-               return identity_Min(node);
-       case iro_Max:
-               return identity_Max(node);
        default:
                return node;
        }
@@ -2809,7 +2759,8 @@ static node_t *identity(node_t *node) {
  * Node follower is a (new) follower of leader, segregate Leader
  * out edges.
  */
-static void segregate_def_use_chain_1(const ir_node *follower, node_t *leader) {
+static void segregate_def_use_chain_1(const ir_node *follower, node_t *leader)
+{
        ir_node *l   = leader->node;
        int     j, i, n = get_irn_n_outs(l);
 
@@ -2835,7 +2786,8 @@ static void segregate_def_use_chain_1(const ir_node *follower, node_t *leader) {
  *
  * @param follower  the follower IR node
  */
-static void segregate_def_use_chain(const ir_node *follower) {
+static void segregate_def_use_chain(const ir_node *follower)
+{
        int i;
 
        for (i = get_irn_arity(follower) - 1; i >= 0; --i) {
@@ -2850,7 +2802,8 @@ static void segregate_def_use_chain(const ir_node *follower) {
  *
  * @param env  the environment
  */
-static void propagate(environment_t *env) {
+static void propagate(environment_t *env)
+{
        partition_t    *X, *Y;
        node_t         *x;
        lattice_elem_t old_type;
@@ -2988,7 +2941,8 @@ static void propagate(environment_t *env) {
  *
  * @param irn  the node
  */
-static ir_node *get_leader(node_t *node) {
+static ir_node *get_leader(node_t *node)
+{
        partition_t *part = node->part;
 
        if (part->n_leader > 1 || node->is_follower) {
@@ -3006,7 +2960,8 @@ static ir_node *get_leader(node_t *node) {
 /**
  * Returns non-zero if a mode_T node has only one reachable output.
  */
-static int only_one_reachable_proj(ir_node *n) {
+static int only_one_reachable_proj(ir_node *n)
+{
        int i, k = 0;
 
        for (i = get_irn_n_outs(n) - 1; i >= 0; --i) {
@@ -3030,13 +2985,20 @@ static int only_one_reachable_proj(ir_node *n) {
  * Return non-zero if the control flow predecessor node pred
  * is the only reachable control flow exit of its block.
  *
- * @param pred  the control flow exit
+ * @param pred   the control flow exit
+ * @param block  the destination block
  */
-static int can_exchange(ir_node *pred) {
-       if (is_Start(pred))
+static int can_exchange(ir_node *pred, ir_node *block)
+{
+       if (is_Start(pred) || get_Block_entity(block) != NULL)
                return 0;
        else if (is_Jmp(pred))
                return 1;
+       else if (is_Raise(pred)) {
+               /* Raise is a tuple and usually has only one reachable ProjX,
+                * but it must not be eliminated like a Jmp */
+               return 0;
+       }
        else if (get_irn_mode(pred) == mode_T) {
                /* if the predecessor block has more than one
                   reachable outputs we cannot remove the block */
@@ -3049,8 +3011,9 @@ static int can_exchange(ir_node *pred) {
  * Block Post-Walker, apply the analysis results on control flow by
  * shortening Phi's and Block inputs.
  */
-static void apply_cf(ir_node *block, void *ctx) {
-       environment_t *env = ctx;
+static void apply_cf(ir_node *block, void *ctx)
+{
+       environment_t *env = (environment_t*)ctx;
        node_t        *node = get_irn_node(block);
        int           i, j, k, n;
        ir_node       **ins, **in_X;
@@ -3065,31 +3028,29 @@ static void apply_cf(ir_node *block, void *ctx) {
                        ir_node *pred = get_Block_cfgpred(block, i);
 
                        if (! is_Bad(pred)) {
-                               node_t *pred_bl = get_irn_node(get_nodes_block(skip_Proj(pred)));
-
-                               if (pred_bl->flagged == 0) {
-                                       pred_bl->flagged = 3;
-
-                                       if (pred_bl->type.tv == tarval_reachable) {
-                                               /*
-                                                * We will remove an edge from block to its pred.
-                                                * This might leave the pred block as an endless loop
-                                                */
-                                               if (! is_backedge(block, i))
-                                                       keep_alive(pred_bl->node);
+                               ir_node *pred_block = get_nodes_block(skip_Proj(pred));
+                               if (!is_Bad(pred_block)) {
+                                       node_t *pred_bl = get_irn_node(pred_block);
+
+                                       if (pred_bl->flagged == 0) {
+                                               pred_bl->flagged = 3;
+
+                                               if (pred_bl->type.tv == tarval_reachable) {
+                                                       /*
+                                                        * We will remove an edge from block to its pred.
+                                                        * This might leave the pred block as an endless loop
+                                                        */
+                                                       if (! is_backedge(block, i))
+                                                               keep_alive(pred_bl->node);
+                                               }
                                        }
                                }
                        }
                }
 
-               /* the EndBlock is always reachable even if the analysis
-                  finds out the opposite :-) */
-               if (block != get_irg_end_block(current_ir_graph)) {
-                       /* mark dead blocks */
-                       set_Block_dead(block);
-                       DB((dbg, LEVEL_1, "Removing dead %+F\n", block));
-               } else {
-                       /* the endblock is unreachable */
+               if (block == get_irg_end_block(current_ir_graph)) {
+                       /* Analysis found out that the end block is unreachable,
+                        * hence we remove all its control flow predecessors. */
                        set_irn_in(block, 0, NULL);
                }
                return;
@@ -3099,7 +3060,7 @@ static void apply_cf(ir_node *block, void *ctx) {
                /* only one predecessor combine */
                ir_node *pred = skip_Proj(get_Block_cfgpred(block, 0));
 
-               if (can_exchange(pred)) {
+               if (can_exchange(pred, block)) {
                        ir_node *new_block = get_nodes_block(pred);
                        DB((dbg, LEVEL_1, "Fuse %+F with %+F\n", block, new_block));
                        DBG_OPT_COMBO(block, new_block, FS_OPT_COMBO_CF);
@@ -3121,18 +3082,21 @@ static void apply_cf(ir_node *block, void *ctx) {
                } else {
                        DB((dbg, LEVEL_1, "Removing dead input %d from %+F (%+F)\n", i, block, pred));
                        if (! is_Bad(pred)) {
-                               node_t *pred_bl = get_irn_node(get_nodes_block(skip_Proj(pred)));
-
-                               if (pred_bl->flagged == 0) {
-                                       pred_bl->flagged = 3;
-
-                                       if (pred_bl->type.tv == tarval_reachable) {
-                                               /*
-                                                * We will remove an edge from block to its pred.
-                                                * This might leave the pred block as an endless loop
-                                                */
-                                               if (! is_backedge(block, i))
-                                                       keep_alive(pred_bl->node);
+                               ir_node *pred_block = get_nodes_block(skip_Proj(pred));
+                               if (!is_Bad(pred_block)) {
+                                       node_t *pred_bl = get_irn_node(pred_block);
+
+                                       if (!is_Bad(pred_bl->node) && pred_bl->flagged == 0) {
+                                               pred_bl->flagged = 3;
+
+                                               if (pred_bl->type.tv == tarval_reachable) {
+                                                       /*
+                                                        * We will remove an edge from block to its pred.
+                                                        * This might leave the pred block as an endless loop
+                                                        */
+                                                       if (! is_backedge(block, i))
+                                                               keep_alive(pred_bl->node);
+                                               }
                                        }
                                }
                        }
@@ -3149,8 +3113,8 @@ static void apply_cf(ir_node *block, void *ctx) {
                next = get_Phi_next(phi);
                if (is_tarval(node->type.tv) && tarval_is_constant(node->type.tv)) {
                        /* this Phi is replaced by a constant */
-                       tarval  *tv = node->type.tv;
-                       ir_node *c  = new_r_Const(current_ir_graph, block, get_tarval_mode(tv), tv);
+                       ir_tarval *tv = node->type.tv;
+                       ir_node   *c  = new_r_Const(current_ir_graph, tv);
 
                        set_irn_node(c, node);
                        node->node = c;
@@ -3190,7 +3154,7 @@ static void apply_cf(ir_node *block, void *ctx) {
                /* this Block has only one live predecessor */
                ir_node *pred = skip_Proj(in_X[0]);
 
-               if (can_exchange(pred)) {
+               if (can_exchange(pred, block)) {
                        ir_node *new_block = get_nodes_block(pred);
                        DBG_OPT_COMBO(block, new_block, FS_OPT_COMBO_CF);
                        exchange(block, new_block);
@@ -3209,26 +3173,95 @@ static void apply_cf(ir_node *block, void *ctx) {
  * AddP(x, NULL) is a follower of x, but with different mode.
  * Fix it here.
  */
-static void exchange_leader(ir_node *irn, ir_node *leader) {
+static void exchange_leader(ir_node *irn, ir_node *leader)
+{
        ir_mode *mode = get_irn_mode(irn);
        if (mode != get_irn_mode(leader)) {
-               /* The conv is a no-op, so we are fre to place in
+               /* The conv is a no-op, so we are free to place it
                 * either in the block of the leader OR in irn's block.
                 * Probably placing it into leaders block might reduce
                 * the number of Conv due to CSE. */
                ir_node  *block = get_nodes_block(leader);
                dbg_info *dbg   = get_irn_dbg_info(irn);
-
-               leader = new_rd_Conv(dbg, current_ir_graph, block, leader, mode);
+               ir_node  *nlead = new_rd_Conv(dbg, block, leader, mode);
+
+               if (nlead != leader) {
+                       /* Note: this newly create irn has no node info because
+                        * it is created after the analysis. However, this node
+                        * replaces the node irn and should not be visited again,
+                        * so set its visited count to the count of irn.
+                        * Otherwise we might visited this node more than once if
+                        * irn had more than one user.
+                        */
+                       set_irn_node(nlead, NULL);
+                       set_irn_visited(nlead, get_irn_visited(irn));
+                       leader = nlead;
+               }
        }
        exchange(irn, leader);
-}
+}  /* exchange_leader */
+
+/**
+ * Check, if all users of a mode_M node are dead. Use
+ * the Def-Use edges for this purpose, as they still
+ * reflect the situation.
+ */
+static int all_users_are_dead(const ir_node *irn)
+{
+       int i, n = get_irn_n_outs(irn);
+
+       for (i = 1; i <= n; ++i) {
+               const ir_node *succ  = irn->out[i].use;
+               const node_t  *block = get_irn_node(get_nodes_block(succ));
+               const node_t  *node;
+
+               if (block->type.tv == tarval_unreachable) {
+                       /* block is unreachable */
+                       continue;
+               }
+               node = get_irn_node(succ);
+               if (node->type.tv != tarval_top) {
+                       /* found a reachable user */
+                       return 0;
+               }
+       }
+       /* all users are unreachable */
+       return 1;
+}  /* all_user_are_dead */
+
+/**
+ * Walker: Find reachable mode_M nodes that have only
+ * unreachable users. These nodes must be kept later.
+ */
+static void find_kept_memory(ir_node *irn, void *ctx)
+{
+       environment_t *env = (environment_t*)ctx;
+       node_t        *node, *block;
+
+       if (get_irn_mode(irn) != mode_M)
+               return;
+
+       block = get_irn_node(get_nodes_block(irn));
+       if (block->type.tv == tarval_unreachable)
+               return;
+
+       node = get_irn_node(irn);
+       if (node->type.tv == tarval_top)
+               return;
+
+       /* ok, we found a live memory node. */
+       if (all_users_are_dead(irn)) {
+               DB((dbg, LEVEL_1, "%+F must be kept\n", irn));
+               ARR_APP1(ir_node *, env->kept_memory, irn);
+       }
+}  /* find_kept_memory */
 
 /**
  * Post-Walker, apply the analysis results;
  */
-static void apply_result(ir_node *irn, void *ctx) {
-       environment_t *env = ctx;
+static void apply_result(ir_node *irn, void *ctx)
+{
+       environment_t *env = (environment_t*)ctx;
        node_t        *node = get_irn_node(irn);
 
        if (is_Block(irn) || is_End(irn) || is_Bad(irn)) {
@@ -3237,7 +3270,9 @@ static void apply_result(ir_node *irn, void *ctx) {
                node_t *block = get_irn_node(get_nodes_block(irn));
 
                if (block->type.tv == tarval_unreachable) {
-                       ir_node *bad = get_irg_bad(current_ir_graph);
+                       ir_graph *irg  = get_irn_irg(irn);
+                       ir_mode  *mode = get_irn_mode(node->node);
+                       ir_node  *bad  = new_r_Bad(irg, mode);
 
                        /* here, bad might already have a node, but this can be safely ignored
                           as long as bad has at least ONE valid node */
@@ -3246,12 +3281,30 @@ static void apply_result(ir_node *irn, void *ctx) {
                        DB((dbg, LEVEL_1, "%+F is unreachable\n", irn));
                        exchange(irn, bad);
                        env->modified = 1;
-               }
-               else if (node->type.tv == tarval_top) {
-                       /* don't kick away Unknown's, they might be still needed */
-                       if (! is_Unknown(irn)) {
-                               ir_mode *mode = get_irn_mode(irn);
-                               ir_node *unk  = new_r_Unknown(current_ir_graph, mode);
+               } else if (node->type.tv == tarval_top) {
+                       ir_mode *mode = get_irn_mode(irn);
+
+                       if (mode == mode_M) {
+                               /* never kill a mode_M node */
+                               if (is_Proj(irn)) {
+                                       ir_node *pred  = get_Proj_pred(irn);
+                                       node_t  *pnode = get_irn_node(pred);
+
+                                       if (pnode->type.tv == tarval_top) {
+                                               /* skip the predecessor */
+                                               ir_node *mem = get_memop_mem(pred);
+                                               node->node = mem;
+                                               DB((dbg, LEVEL_1, "%+F computes Top, replaced by %+F\n", irn, mem));
+                                               exchange(irn, mem);
+                                               env->modified = 1;
+                                       }
+                               }
+                               /* leave other nodes, especially PhiM */
+                       } else if (mode == mode_T) {
+                               /* Do not kill mode_T nodes, kill their Projs */
+                       } else if (! is_Unknown(irn)) {
+                               /* don't kick away Unknown's, they might be still needed */
+                               ir_node *unk = new_r_Unknown(current_ir_graph, mode);
 
                                /* control flow should already be handled at apply_cf() */
                                assert(mode != mode_X);
@@ -3269,9 +3322,9 @@ static void apply_result(ir_node *irn, void *ctx) {
                                /* leave or Jmp */
                                ir_node *cond = get_Proj_pred(irn);
 
-                               if (is_Cond(cond)) {
+                               if (is_Cond(cond) || is_Switch(cond)) {
                                        if (only_one_reachable_proj(cond)) {
-                                               ir_node *jmp = new_r_Jmp(current_ir_graph, block->node);
+                                               ir_node *jmp = new_r_Jmp(block->node);
                                                set_irn_node(jmp, node);
                                                node->node = jmp;
                                                DB((dbg, LEVEL_1, "%+F is replaced by %+F\n", irn, jmp));
@@ -3279,14 +3332,16 @@ static void apply_result(ir_node *irn, void *ctx) {
                                                exchange(irn, jmp);
                                                env->modified = 1;
                                        } else {
-                                               node_t *sel = get_irn_node(get_Cond_selector(cond));
-                                               tarval *tv  = sel->type.tv;
-
-                                               if (is_tarval(tv) && tarval_is_constant(tv)) {
-                                                       /* The selector is a constant, but more
-                                                        * than one output is active: An unoptimized
-                                                        * case found. */
-                                                       env->unopt_cf = 1;
+                                               if (is_Switch(cond)) {
+                                                       node_t    *sel = get_irn_node(get_Switch_selector(cond));
+                                                       ir_tarval *tv  = sel->type.tv;
+
+                                                       if (is_tarval(tv) && tarval_is_constant(tv)) {
+                                                               /* The selector is a constant, but more
+                                                                * than one output is active: An unoptimized
+                                                                * case found. */
+                                                               env->unopt_cf = 1;
+                                                       }
                                                }
                                        }
                                }
@@ -3294,7 +3349,7 @@ static void apply_result(ir_node *irn, void *ctx) {
                } else {
                        /* normal data node */
                        if (is_tarval(node->type.tv) && tarval_is_constant(node->type.tv)) {
-                               tarval *tv = node->type.tv;
+                               ir_tarval *tv = node->type.tv;
 
                                /*
                                 * Beware: never replace mode_T nodes by constants. Currently we must mark
@@ -3302,7 +3357,7 @@ static void apply_result(ir_node *irn, void *ctx) {
                                 */
                                if (! is_Const(irn) && get_irn_mode(irn) != mode_T) {
                                        /* can be replaced by a constant */
-                                       ir_node *c = new_r_Const(current_ir_graph, block->node, get_tarval_mode(tv), tv);
+                                       ir_node *c = new_r_Const(current_ir_graph, tv);
                                        set_irn_node(c, node);
                                        node->node = c;
                                        DB((dbg, LEVEL_1, "%+F is replaced by %+F\n", irn, c));
@@ -3313,7 +3368,7 @@ static void apply_result(ir_node *irn, void *ctx) {
                        } else if (is_entity(node->type.sym.entity_p)) {
                                if (! is_SymConst(irn)) {
                                        /* can be replaced by a SymConst */
-                                       ir_node *symc = new_r_SymConst(current_ir_graph, block->node, get_irn_mode(irn), node->type.sym, symconst_addr_ent);
+                                       ir_node *symc = new_r_SymConst(current_ir_graph, get_irn_mode(irn), node->type.sym, symconst_addr_ent);
                                        set_irn_node(symc, node);
                                        node->node = symc;
 
@@ -3364,22 +3419,32 @@ static void apply_result(ir_node *irn, void *ctx) {
 /**
  * Fix the keep-alives by deleting unreachable ones.
  */
-static void apply_end(ir_node *end, environment_t *env) {
+static void apply_end(ir_node *end, environment_t *env)
+{
        int i, j,  n = get_End_n_keepalives(end);
-       ir_node **in;
+       ir_node **in = NULL;
 
        if (n > 0)
                NEW_ARR_A(ir_node *, in, n);
 
        /* fix the keep alive */
        for (i = j = 0; i < n; i++) {
-               ir_node *ka   = get_End_keepalive(end, i);
-               node_t  *node = get_irn_node(ka);
+               ir_node *ka = get_End_keepalive(end, i);
+               ir_node *block;
+               node_t  *node;
 
-               if (! is_Block(ka))
-                       node = get_irn_node(get_nodes_block(ka));
+               if (is_Bad(ka))
+                       continue;
+               if (!is_Block(ka)) {
+                       block = get_nodes_block(ka);
+                       if (is_Bad(block))
+                               continue;
+               } else {
+                       block = ka;
+               }
 
-               if (node->type.tv != tarval_unreachable && !is_Bad(ka))
+               node = get_irn_node(block);
+               if (node->type.tv != tarval_unreachable)
                        in[j++] = ka;
        }
        if (j != n) {
@@ -3393,11 +3458,12 @@ static void apply_end(ir_node *end, environment_t *env) {
 /**
  * sets the generic functions to compute.
  */
-static void set_compute_functions(void) {
-       int i;
+static void set_compute_functions(void)
+{
+       size_t i, n;
 
        /* set the default compute function */
-       for (i = get_irp_n_opcodes() - 1; i >= 0; --i) {
+       for (i = 0, n = get_irp_n_opcodes(); i < n; ++i) {
                ir_op *op = get_irp_opcode(i);
                op->ops.generic = (op_func)default_compute;
        }
@@ -3418,19 +3484,41 @@ static void set_compute_functions(void) {
        SET(Return);
        SET(End);
        SET(Call);
+}  /* set_compute_functions */
 
-       if (op_Max != NULL)
-               SET(Max);
-       if (op_Min != NULL)
-               SET(Min);
+/**
+ * Add memory keeps.
+ */
+static void add_memory_keeps(ir_node **kept_memory, size_t len)
+{
+       ir_node      *end = get_irg_end(current_ir_graph);
+       int          i;
+       size_t       idx;
+       ir_nodeset_t set;
 
-}  /* set_compute_functions */
+       ir_nodeset_init(&set);
+
+       /* check, if those nodes are already kept */
+       for (i = get_End_n_keepalives(end) - 1; i >= 0; --i)
+               ir_nodeset_insert(&set, get_End_keepalive(end, i));
 
-void combo(ir_graph *irg) {
+       for (idx = 0; idx < len; ++idx) {
+               ir_node *ka = kept_memory[idx];
+
+               if (! ir_nodeset_contains(&set, ka)) {
+                       add_End_keepalive(end, ka);
+               }
+       }
+       ir_nodeset_destroy(&set);
+}  /* add_memory_keeps */
+
+static ir_graph_state_t do_combo(ir_graph *irg)
+{
        environment_t env;
        ir_node       *initial_bl;
        node_t        *start;
        ir_graph      *rem = current_ir_graph;
+       size_t        len;
 
        current_ir_graph = irg;
 
@@ -3448,23 +3536,27 @@ void combo(ir_graph *irg) {
        env.dbg_list       = NULL;
 #endif
        env.opcode2id_map  = new_set(cmp_opcode, iro_Last * 4);
-       env.type2id_map    = pmap_create();
+       env.kept_memory    = NEW_ARR_F(ir_node *, 0);
        env.end_idx        = get_opt_global_cse() ? 0 : -1;
        env.lambda_input   = 0;
-       env.commutative    = 1;
        env.modified       = 0;
        env.unopt_cf       = 0;
-
-       assure_irg_outs(irg);
-       assure_cf_loop(irg);
+       /* options driving the optimization */
+       env.commutative    = 1;
+       env.opt_unknown    = 1;
 
        /* we have our own value_of function */
        set_value_of_func(get_node_tarval);
 
        set_compute_functions();
-       DEBUG_ONLY(part_nr = 0);
+       DEBUG_ONLY(part_nr = 0;)
 
-       ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
+       ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK | IR_RESOURCE_PHI_LIST);
+
+       if (env.opt_unknown)
+               tarval_UNKNOWN = tarval_top;
+       else
+               tarval_UNKNOWN = tarval_bad;
 
        /* create the initial partition and place it on the work list */
        env.initial = new_partition(&env);
@@ -3472,7 +3564,7 @@ void combo(ir_graph *irg) {
        irg_walk_graph(irg, create_initial_partitions, init_block_phis, &env);
 
        /* set the hook: from now, every node has a partition and a type */
-       DEBUG_ONLY(set_dump_node_vcgattr_hook(dump_partition_hook));
+       DEBUG_ONLY(set_dump_node_vcgattr_hook(dump_partition_hook);)
 
        /* all nodes on the initial partition have type Top */
        env.initial->type_is_T_or_C = 1;
@@ -3497,6 +3589,11 @@ void combo(ir_graph *irg) {
 #endif
 
        /* apply the result */
+
+       /* check, which nodes must be kept */
+       irg_walk_graph(irg, NULL, find_kept_memory, &env);
+
+       /* kill unreachable control flow */
        irg_block_walk_graph(irg, NULL, apply_cf, &env);
        /* Kill keep-alives of dead blocks: this speeds up apply_result()
         * and fixes assertion because dead cf to dead blocks is NOT removed by
@@ -3504,28 +3601,43 @@ void combo(ir_graph *irg) {
        apply_end(get_irg_end(irg), &env);
        irg_walk_graph(irg, NULL, apply_result, &env);
 
+       len = ARR_LEN(env.kept_memory);
+       if (len > 0)
+               add_memory_keeps(env.kept_memory, len);
+
        if (env.unopt_cf) {
                DB((dbg, LEVEL_1, "Unoptimized Control Flow left"));
        }
 
-       if (env.modified) {
-               /* control flow might changed */
-               set_irg_outs_inconsistent(irg);
-               set_irg_extblk_inconsistent(irg);
-               set_irg_doms_inconsistent(irg);
-               set_irg_loopinfo_inconsistent(irg);
-       }
-
-       ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
+       ir_free_resources(irg, IR_RESOURCE_IRN_LINK | IR_RESOURCE_PHI_LIST);
 
        /* remove the partition hook */
-       DEBUG_ONLY(set_dump_node_vcgattr_hook(NULL));
+       DEBUG_ONLY(set_dump_node_vcgattr_hook(NULL);)
 
-       pmap_destroy(env.type2id_map);
+       DEL_ARR_F(env.kept_memory);
        del_set(env.opcode2id_map);
        obstack_free(&env.obst, NULL);
 
        /* restore value_of() default behavior */
        set_value_of_func(NULL);
        current_ir_graph = rem;
+
+       return 0; // cannot guarantee anything
 }  /* combo */
+
+static optdesc_t opt_combo = {
+       "combo",
+       IR_GRAPH_STATE_NO_BADS | IR_GRAPH_STATE_CONSISTENT_OUTS | IR_GRAPH_STATE_CONSISTENT_LOOPINFO,
+       do_combo,
+};
+
+void combo(ir_graph *irg)
+{
+       perform_irg_optimization(irg, &opt_combo);
+}
+
+/* Creates an ir_graph pass for combo. */
+ir_graph_pass_t *combo_pass(const char *name)
+{
+       return def_graph_pass(name ? name : "combo", combo);
+}  /* combo_pass */