- BugFix: removed missing debugging artefact, causing partitions with
[libfirm] / ir / opt / combo.c
index 376beab..057dacd 100644 (file)
@@ -48,7 +48,9 @@
 #include "irop.h"
 #include "irouts.h"
 #include "irgmod.h"
+#include "iropt_dbg.h"
 #include "debug.h"
+#include "array_t.h"
 #include "error.h"
 
 #include "tv_t.h"
 #include "irdump.h"
 
 /* define this to check that all type translations are monotone */
-#define VERIFY_MONOTONE
+#undef VERIFY_MONOTONE
 
 /* define this to check the consistency of partitions */
 #define CHECK_PARTITIONS
 
-/* define this to disable followers (may be buggy) */
-#undef NO_FOLLOWER
-
 typedef struct node_t            node_t;
 typedef struct partition_t       partition_t;
 typedef struct opcode_key_t      opcode_key_t;
@@ -128,8 +127,8 @@ struct node_t {
        unsigned        on_cprop:1;     /**< Set, if this node is on the partition.cprop list. */
        unsigned        on_fallen:1;    /**< Set, if this node is on the fallen list. */
        unsigned        is_follower:1;  /**< Set, if this node is a follower. */
-       unsigned        is_flagged:1;   /**< Set, if this node is flagged by step(). */
        unsigned        by_all_const:1; /**< Set, if this node was once evaluated by all constants. */
+       unsigned        flagged:2;      /**< 2 Bits, set if this node was visited by race 1 or 2. */
 };
 
 /**
@@ -167,7 +166,8 @@ typedef struct environment_t {
        pmap            *type2id_map;   /**< The type->id map. */
        int             end_idx;        /**< -1 for local and 0 for global congruences. */
        int             lambda_input;   /**< Captured argument for lambda_partition(). */
-       int             modified;       /**< Set, if the graph was modified. */
+       char            nonstd_cond;    /**< Set, if a Condb note has a non-Cmp predecessor. */
+       char            modified;       /**< Set, if the graph was modified. */
 #ifdef DEBUG_libfirm
        partition_t     *dbg_list;      /**< List of all partitions. */
 #endif
@@ -190,6 +190,9 @@ DEBUG_ONLY(static firm_dbg_module_t *dbg;)
 /** Next partition number. */
 DEBUG_ONLY(static unsigned part_nr = 0);
 
+/** The tarval returned by Unknown nodes. */
+static tarval *tarval_UNKNOWN;
+
 /* forward */
 static node_t *identity(node_t *node);
 
@@ -203,6 +206,7 @@ static void check_partition(const partition_t *T) {
 
        list_for_each_entry(node_t, node, &T->Leader, node_list) {
                assert(node->is_follower == 0);
+               assert(node->flagged == 0);
                assert(node->part == T);
                ++n;
        }
@@ -210,11 +214,51 @@ static void check_partition(const partition_t *T) {
 
        list_for_each_entry(node_t, node, &T->Follower, node_list) {
                assert(node->is_follower == 1);
+               assert(node->flagged == 0);
                assert(node->part == T);
        }
 }  /* check_partition */
+
+static void check_all_partitions(environment_t *env) {
+       partition_t *P;
+       node_t      *node;
+
+#ifdef DEBUG_libfirm
+       for (P = env->dbg_list; P != NULL; P = P->dbg_next) {
+               check_partition(P);
+               list_for_each_entry(node_t, node, &P->Follower, node_list) {
+                       node_t *leader = identity(node);
+
+                       assert(leader != node && leader->part == node->part);
+               }
+       }
+#endif
+}
+
+/**
+ * Check list.
+ */
+static void do_check_list(const node_t *list, int ofs, const partition_t *Z) {
+       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
+}  /* ido_check_list */
+
+/**
+ * Check a local list.
+ */
+static void check_list(const node_t *list, const partition_t *Z) {
+       do_check_list(list, offsetof(node_t, next), Z);
+}  /* check_list */
+
 #else
 #define check_partition(T)
+#define check_list(list, Z)
+#define check_all_partitions(env)
 #endif /* CHECK_PARTITIONS */
 
 #ifdef DEBUG_libfirm
@@ -456,6 +500,7 @@ static INLINE tarval *get_node_tarval(const ir_node *irn) {
  */
 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;
        X->on_worklist = 1;
        env->worklist  = X;
@@ -543,8 +588,8 @@ static node_t *create_partition_node(ir_node *irn, partition_t *part, environmen
        node->on_cprop       = 0;
        node->on_fallen      = 0;
        node->is_follower    = 0;
-       node->is_flagged     = 0;
        node->by_all_const   = 0;
+       node->flagged        = 0;
        set_irn_node(irn, node);
 
        list_add_tail(&node->node_list, &part->Leader);
@@ -580,6 +625,11 @@ static void create_initial_partitions(ir_node *irn, void *ctx) {
 
        if (is_Phi(irn)) {
                add_Block_phi(get_nodes_block(irn), irn);
+       } else if (is_Cond(irn)) {
+               /* check if all Cond's have a Cmp predecessor. */
+               if (get_irn_mode(irn) == mode_b && !is_Cmp(skip_Proj(get_Cond_selector(irn))))
+                       env->nonstd_cond = 1;
+
        }
 }  /* create_initial_partitions */
 
@@ -604,6 +654,8 @@ static INLINE void add_to_touched(node_t *y, environment_t *env) {
                        env->touched       = part;
                        part->on_touched   = 1;
                }
+
+               check_list(part->touched, part);
        }
 }  /* add_to_touched */
 
@@ -742,7 +794,7 @@ static partition_t *split_no_followers(partition_t *Z, node_t *g, environment_t
        Z_prime = new_partition(env);
        max_input = 0;
        for (node = g; node != NULL; node = node->next) {
-               list_add(&node->node_list, &Z_prime->Leader);
+               list_add_tail(&node->node_list, &Z_prime->Leader);
                node->part = Z_prime;
                if (node->max_user_input > max_input)
                        max_input = node->max_user_input;
@@ -763,11 +815,21 @@ static partition_t *split_no_followers(partition_t *Z, node_t *g, environment_t
        return Z_prime;
 }  /* split_no_followers */
 
-#ifdef NO_FOLLOWER
+/**
+ * Make the Follower -> Leader transition for a node.
+ *
+ * @param n  the node
+ */
+static void follower_to_leader(node_t *n) {
+       assert(n->is_follower == 1);
 
-#define split(Z, g, env) split_no_followers(*(Z), g, env)
-
-#else
+       DB((dbg, LEVEL_2, "%+F make the follower -> leader transition\n", n->node));
+       n->is_follower = 0;
+       move_edges_to_leader(n);
+       list_del(&n->node_list);
+       list_add_tail(&n->node_list, &n->part->Leader);
+       ++n->part->n_leader;
+}  /* follower_to_leader */
 
 /**
  * The environment for one race step.
@@ -777,9 +839,78 @@ typedef struct step_env {
        node_t   *unwalked;   /**< The unwalked node list. */
        node_t   *walked;     /**< The walked node list. */
        int      index;       /**< Next index of Follower use_def edge. */
-       unsigned n_leader;    /**< number of Leader in initial. */
+       unsigned side;        /**< side number. */
 } step_env;
 
+/**
+ * Return non-zero, if a input is a real follower
+ *
+ * @param irn    the node to check
+ * @param input  number of the input
+ */
+static int is_real_follower(const ir_node *irn, int input) {
+       node_t *pred;
+
+       switch (get_irn_opcode(irn)) {
+       case iro_Confirm:
+               if (input == 1) {
+                       /* ignore the Confirm bound input */
+                       return 0;
+               }
+               break;
+       case iro_Mux:
+               if (input == 0) {
+                       /* ignore the Mux sel input */
+                       return 0;
+               }
+               break;
+       case iro_Phi: {
+               /* dead inputs are not follower edges */
+               ir_node *block = get_nodes_block(irn);
+               node_t  *pred  = get_irn_node(get_Block_cfgpred(block, input));
+
+               if (pred->type.tv == tarval_unreachable)
+                       return 0;
+               break;
+       }
+       case iro_Sub:
+       case iro_Shr:
+       case iro_Shl:
+       case iro_Shrs:
+       case iro_Rotl:
+               if (input == 1) {
+                       /* only a Sub x,0 / Shift x,0 might be a follower */
+                       return 0;
+               }
+               break;
+       case iro_Add:
+       case iro_Or:
+       case iro_Eor:
+               pred = get_irn_node(get_irn_n(irn, input));
+               if (is_tarval(pred->type.tv) && tarval_is_null(pred->type.tv))
+                       return 0;
+               break;
+       case iro_Mul:
+               pred = get_irn_node(get_irn_n(irn, input));
+               if (is_tarval(pred->type.tv) && tarval_is_one(pred->type.tv))
+                       return 0;
+               break;
+       case iro_And:
+               pred = get_irn_node(get_irn_n(irn, 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;
+       }
+       return 1;
+}
+
 /**
  * Do one step in the race.
  */
@@ -801,24 +932,38 @@ static int step(step_env *env) {
                /* let n be the first node in unwalked */
                n = env->unwalked;
                while (env->index < n->n_followers) {
+                       const ir_def_use_edge *edge = &n->node->out[1 + env->index];
+
                        /* let m be n.F.def_use[index] */
-                       node_t *m = get_irn_node(n->node->out[1 + env->index].use);
+                       node_t *m = get_irn_node(edge->use);
 
                        assert(m->is_follower);
+                       /*
+                        * Some inputs, like the get_Confirm_bound are NOT
+                        * real followers, sort them out.
+                        */
+                       if (! is_real_follower(m->node, edge->pos)) {
+                               ++env->index;
+                               continue;
+                       }
                        ++env->index;
 
                        /* only followers from our partition */
                        if (m->part != n->part)
                                continue;
 
-                       if (!m->is_flagged) {
-                               m->is_flagged = 1;
+                       if ((m->flagged & env->side) == 0) {
+                               m->flagged |= env->side;
 
-                               /* add m to unwalked not as first node (we might still need to
-                                  check for more follower node */
-                               m->race_next = n->race_next;
-                               n->race_next = m;
-                               return 0;
+                               if (m->flagged != 3) {
+                                       /* visited the first time */
+                                       /* add m to unwalked not as first node (we might still need to
+                                          check for more follower node */
+                                       m->race_next = n->race_next;
+                                       n->race_next = m;
+                                       return 0;
+                               }
+                               /* else already visited by the other side and on the other list */
                        }
                }
                /* move n to walked */
@@ -831,15 +976,25 @@ static int step(step_env *env) {
 }  /* step */
 
 /**
- * Clear the flags from a list.
+ * Clear the flags from a list and check for
+ * nodes that where touched from both sides.
  *
  * @param list  the list
  */
-static void clear_flags(node_t *list) {
+static int clear_flags(node_t *list) {
+       int    res = 0;
        node_t *n;
 
-       for (n = list; n != NULL; n = n->race_next)
-               n->is_flagged = 0;
+       for (n = list; n != NULL; n = n->race_next) {
+               if (n->flagged == 3) {
+                       /* we reach a follower from both sides, this will split congruent
+                        * inputs and make it a leader. */
+                       follower_to_leader(n);
+                       res = 1;
+               }
+               n->flagged = 0;
+       }
+       return res;
 }  /* clear_flags */
 
 /**
@@ -857,8 +1012,8 @@ static partition_t *split(partition_t **pX, node_t *gg, environment_t *env) {
        list_head   tmp;
        step_env    env1, env2, *winner;
        node_t      *g, *h, *node, *t;
-       int         max_input;
-       unsigned    n, m;
+       int         max_input, transitions;
+       unsigned    n;
        DEBUG_ONLY(static int run = 0;)
 
        DB((dbg, LEVEL_2, "Run %d ", run++));
@@ -876,7 +1031,6 @@ static partition_t *split(partition_t **pX, node_t *gg, environment_t *env) {
 
        /* Remove gg from X.Leader and put into g */
        g = NULL;
-       n = 0;
        for (node = gg; node != NULL; node = node->next) {
                assert(node->part == X);
                assert(node->is_follower == 0);
@@ -885,15 +1039,12 @@ static partition_t *split(partition_t **pX, node_t *gg, environment_t *env) {
                list_add_tail(&node->node_list, &tmp);
                node->race_next = g;
                g               = node;
-               ++n;
        }
        /* produce h */
        h = NULL;
-       m = 0;
        list_for_each_entry(node_t, node, &X->Leader, node_list) {
                node->race_next = h;
                h               = node;
-               ++m;
        }
        /* restore X.Leader */
        list_splice(&tmp, &X->Leader);
@@ -902,13 +1053,13 @@ static partition_t *split(partition_t **pX, node_t *gg, environment_t *env) {
        env1.unwalked      = NULL;
        env1.walked        = NULL;
        env1.index         = 0;
-       env1.n_leader      = n;
+       env1.side          = 1;
 
        env2.initial       = h;
        env2.unwalked      = NULL;
        env2.walked        = NULL;
        env2.index         = 0;
-       env2.n_leader      = m;
+       env2.side          = 2;
 
        for (;;) {
                if (step(&env1)) {
@@ -924,53 +1075,66 @@ static partition_t *split(partition_t **pX, node_t *gg, environment_t *env) {
        assert(winner->unwalked == NULL);
 
        /* clear flags from walked/unwalked */
-       clear_flags(env1.unwalked);
-       clear_flags(env1.walked);
-       clear_flags(env2.unwalked);
-       clear_flags(env2.walked);
+       transitions  = clear_flags(env1.unwalked);
+       transitions |= clear_flags(env1.walked);
+       transitions |= clear_flags(env2.unwalked);
+       transitions |= clear_flags(env2.walked);
 
        dump_race_list("winner ", winner->walked);
 
        /* Move walked_{winner} to a new partition, X'. */
-       X_prime = new_partition(env);
+       X_prime   = new_partition(env);
        max_input = 0;
+       n         = 0;
        for (node = winner->walked; node != NULL; node = node->race_next) {
                list_del(&node->node_list);
                node->part = X_prime;
                if (node->is_follower) {
-                       list_add(&node->node_list, &X_prime->Follower);
+                       list_add_tail(&node->node_list, &X_prime->Follower);
                } else {
-                       list_add(&node->node_list, &X_prime->Leader);
-                       ++X_prime->n_leader;
+                       list_add_tail(&node->node_list, &X_prime->Leader);
+                       ++n;
                }
                if (node->max_user_input > max_input)
                        max_input = node->max_user_input;
        }
+       X_prime->n_leader        = n;
        X_prime->max_user_inputs = max_input;
        X->n_leader             -= X_prime->n_leader;
 
        /* for now, copy the type info tag, it will be adjusted in split_by(). */
        X_prime->type_is_T_or_C = X->type_is_T_or_C;
 
-       /* do the Follower -> Leader transition for nodes that loose congruent inputs */
+       /*
+        * Even if a follower was not checked by both sides, it might have
+        * loose its congruence, so we need to check this case for all follower.
+        */
        list_for_each_entry_safe(node_t, node, t, &X_prime->Follower, node_list) {
                if (identity(node) == node) {
-                       /* we reach a follower from both sides, this will split congruent
-                        * inputs and make it a leader. */
-                       DB((dbg, LEVEL_2, "%+F make the follower -> leader transition\n", node->node));
-                       node->is_follower = 0;
-                       move_edges_to_leader(node);
-                       list_del(&node->node_list);
-                       list_add(&node->node_list, &X_prime->Leader);
-                       ++X_prime->n_leader;
+                       follower_to_leader(node);
+                       transitions = 1;
                }
        }
+
        check_partition(X);
        check_partition(X_prime);
 
        /* X' is the smaller part */
        add_to_worklist(X_prime, env);
 
+       /*
+        * If there where follower to leader transitions, ensure that the nodes
+        * can be split out if necessary.
+        */
+       if (transitions) {
+               /* place partitions on the cprop list */
+                if (X_prime->on_cprop == 0) {
+                       X_prime->cprop_next = env->cprop;
+                       env->cprop          = X_prime;
+                       X_prime->on_cprop   = 1;
+               }
+       }
+
        dump_partition("Now ", X);
        dump_partition("Created new ", X_prime);
 
@@ -982,7 +1146,6 @@ static partition_t *split(partition_t **pX, node_t *gg, environment_t *env) {
 
        return X_prime;
 }  /* split */
-#endif /* NO_FOLLOWER */
 
 /**
  * Returns non-zero if the i'th input of a Phi node is live.
@@ -1048,14 +1211,14 @@ static void collect_touched(list_head *list, int idx, environment_t *env) {
 
                if (idx == -1) {
                        /* leader edges start AFTER follower edges */
-                       x->next_edge = 1 + x->n_followers;
+                       x->next_edge = x->n_followers + 1;
                }
                num_edges = get_irn_n_outs(x->node);
 
                /* for all edges in x.L.def_use_{idx} */
                while (x->next_edge <= num_edges) {
-                       ir_def_use_edge *edge = &x->node->out[x->next_edge];
-                       ir_node         *succ;
+                       const ir_def_use_edge *edge = &x->node->out[x->next_edge];
+                       ir_node               *succ;
 
                        /* check if we have necessary edges */
                        if (edge->pos > idx)
@@ -1071,6 +1234,7 @@ static void collect_touched(list_head *list, int idx, environment_t *env) {
                                continue;
 
                        y = get_irn_node(succ);
+                       assert(get_irn_n(succ, idx) == x->node);
 
                        /* ignore block edges touching followers */
                        if (idx == -1 && y->is_follower)
@@ -1078,7 +1242,7 @@ static void collect_touched(list_head *list, int idx, environment_t *env) {
 
                        if (is_constant_type(y->type)) {
                                ir_opcode code = get_irn_opcode(succ);
-                               if (code == iro_Sub || code == iro_Cmp)
+                               if (code == iro_Sub || code == iro_Eor || code == iro_Cmp)
                                        add_to_cprop(y, env);
                        }
 
@@ -1137,10 +1301,11 @@ static void cause_splits(environment_t *env) {
                        Z->touched   = NULL;
                        Z->n_touched = 0;
 
-                       if (n_touched > 0 && Z->n_leader != n_touched) {
+                       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);
-                       }
+                       } else
+                               assert(n_touched <= Z->n_leader);
                }
        }
 }  /* cause_splits */
@@ -1432,10 +1597,8 @@ static void compute_Unknown(node_t *node) {
         * 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...
-        *
-        * For now, we compute bottom here.
         */
-       node->type.tv = tarval_bottom;
+       node->type.tv = tarval_UNKNOWN;
 }  /* compute_Unknown */
 
 /**
@@ -1616,6 +1779,47 @@ static void compute_Sub(node_t *node) {
        }
 }  /* compute_Sub */
 
+/**
+ * (Re-)compute the type for an Eor. Special case: both nodes are congruent.
+ *
+ * @param node  the 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;
+
+       if (a.tv == tarval_top || b.tv == tarval_top) {
+               node->type.tv = tarval_top;
+       } else if (is_con(a) && is_con(b)) {
+               if (is_tarval(a.tv) && is_tarval(b.tv)) {
+                       node->type.tv = tarval_eor(a.tv, b.tv);
+               } else if (is_tarval(a.tv) && tarval_is_null(a.tv)) {
+                       node->type = b;
+               } else if (is_tarval(b.tv) && tarval_is_null(b.tv)) {
+                       node->type = a;
+               } else {
+                       node->type.tv = tarval_bottom;
+               }
+               node->by_all_const = 1;
+       } else if (r->part == l->part) {
+               ir_mode *mode = get_irn_mode(eor);
+               tv = get_mode_null(mode);
+
+               /* if the node was ONCE evaluated by all constants, but now
+                  this breakes AND we cat by partition a different result, switch to bottom.
+                  This happens because initially all nodes are in the same partition ... */
+               if (node->by_all_const && node->type.tv != tv)
+                       tv = tarval_bottom;
+               node->type.tv = tv;
+       } else {
+               node->type.tv = tarval_bottom;
+       }
+}  /* compute_Eor */
+
 /**
  * (Re-)compute the type for Cmp.
  *
@@ -1629,7 +1833,15 @@ static void compute_Cmp(node_t *node) {
        lattice_elem_t b     = r->type;
 
        if (a.tv == tarval_top || b.tv == tarval_top) {
+#ifdef WITH_UNKNOWN
+               /*
+                * Top is congruent to any other value, we can
+                * calculate the compare result.
+                */
+               node->type.tv = tarval_b_true;
+#else
                node->type.tv = tarval_top;
+#endif
        } else if (is_con(a) && is_con(b)) {
                /* both nodes are constants, we can probably do something */
                node->type.tv = tarval_b_true;
@@ -1657,7 +1869,13 @@ static void compute_Proj_Cmp(node_t *node, ir_node *cmp) {
        tarval         *tv;
 
        if (a.tv == tarval_top || b.tv == tarval_top) {
+#ifdef WITH_UNKNOWN
+               /* see above */
+               tv = new_tarval_from_long((pnc & pn_Cmp_Eq) ^ pn_Cmp_Eq, mode_b);
+               goto not_equal;
+#else
                node->type.tv = tarval_top;
+#endif
        } else if (is_con(a) && is_con(b)) {
                default_compute(node);
                node->by_all_const = 1;
@@ -1668,6 +1886,9 @@ static void compute_Proj_Cmp(node_t *node, ir_node *cmp) {
                 * NaN != NaN is defined, so we must check this here.
                 */
                tv = new_tarval_from_long(pnc & pn_Cmp_Eq, mode_b);
+#ifdef WITH_UNKNOWN
+not_equal:
+#endif
 
                /* if the node was ONCE evaluated by all constants, but now
                   this breakes AND we cat by partition a different result, switch to bottom.
@@ -1995,8 +2216,22 @@ static node_t *identity_comm_zero_binop(node_t *node) {
        return node;
 }  /* identity_comm_zero_binop */
 
-#define identity_Add  identity_comm_zero_binop
-#define identity_Or   identity_comm_zero_binop
+/**
+ * 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;
+
+       /* node: no input should be tarval_top, else the binop would be also
+        * Top and not being split. */
+       zero = get_mode_null(mode);
+       if (b->type.tv == zero)
+               return get_irn_node(get_binop_left(op));
+       return node;
+}  /* identity_shift */
 
 /**
  * Calculates the Identity for Mul nodes.
@@ -2074,18 +2309,23 @@ static node_t *identity_Confirm(node_t *node) {
  */
 static node_t *identity_Mux(node_t *node) {
        ir_node *mux = node->node;
-       node_t  *sel = get_irn_node(get_Mux_sel(mux));
        node_t  *t   = get_irn_node(get_Mux_true(mux));
        node_t  *f   = get_irn_node(get_Mux_false(mux));
+       /*node_t  *sel; */
 
        if (t->part == f->part)
                return t;
 
+       /* for now, the 1-input identity is not supported */
+#if 0
+       sel = get_irn_node(get_Mux_sel(mux));
+
        /* Mux sel input is mode_b, so it is always a tarval */
        if (sel->type.tv == tarval_b_true)
                return t;
        if (sel->type.tv == tarval_b_false)
                return f;
+#endif
        return node;
 }  /* identity_Mux */
 
@@ -2146,12 +2386,17 @@ static node_t *identity(node_t *node) {
        switch (get_irn_opcode(irn)) {
        case iro_Phi:
                return identity_Phi(node);
-       case iro_Add:
-               return identity_Add(node);
        case iro_Mul:
                return identity_Mul(node);
+       case iro_Add:
        case iro_Or:
-               return identity_Or(node);
+       case iro_Eor:
+               return identity_comm_zero_binop(node);
+       case iro_Shr:
+       case iro_Shl:
+       case iro_Shrs:
+       case iro_Rotl:
+               return identity_shift(node);
        case iro_And:
                return identity_And(node);
        case iro_Sub:
@@ -2239,14 +2484,12 @@ static void propagate(environment_t *env) {
                while (! list_empty(&X->cprop)) {
                        /* remove the first Node x from X.cprop */
                        x = list_entry(X->cprop.next, node_t, cprop_list);
-                       assert(x->part == X);
+                       //assert(x->part == X);
                        list_del(&x->cprop_list);
                        x->on_cprop = 0;
 
                        if (x->is_follower && identity(x) == x) {
-                               /* x will make the follower -> leader transition */
-                               DB((dbg, LEVEL_2, "%+F make the follower -> leader transition\n", x->node));
-
+                               /* check the opcode first */
                                if (oldopcode == NULL) {
                                        oldopcode = lambda_opcode(get_first_node(X), env);
                                }
@@ -2261,14 +2504,8 @@ static void propagate(environment_t *env) {
                                        }
                                }
 
-                               /* move x from X.Follower to X.Leader */
-                               list_del(&x->node_list);
-                               list_add_tail(&x->node_list, &X->Leader);
-                               x->is_follower = 0;
-                               X->n_leader++;
-
-                               /* Make all inputs to x from inside X no longer be F.def_use edges */
-                               move_edges_to_leader(x);
+                               /* x will make the follower -> leader transition */
+                               follower_to_leader(x);
                        }
 
                        /* compute a new type for x */
@@ -2301,6 +2538,11 @@ static void propagate(environment_t *env) {
                if (n_fallen > 0 && n_fallen != X->n_leader) {
                        DB((dbg, LEVEL_2, "Splitting part%d by fallen\n", X->nr));
                        Y = split(&X, fallen, env);
+                       /*
+                        * We have split out fallen node. The type of the result
+                        * partition is NOT set yet.
+                        */
+                       Y->type_is_T_or_C = 0;
                } else {
                        Y = X;
                }
@@ -2308,13 +2550,9 @@ static void propagate(environment_t *env) {
                for (x = fallen; x != NULL; x = x->next)
                        x->on_fallen = 0;
 
-#ifndef NO_FOLLOWER
                if (old_type_was_T_or_C) {
                        node_t *y, *tmp;
 
-                       if (Y->on_worklist == 0)
-                               add_to_worklist(Y, env);
-
                        /* check if some nodes will make the leader -> follower transition */
                        list_for_each_entry_safe(node_t, y, tmp, &Y->Leader, node_list) {
                                if (y->type.tv != tarval_top && ! is_con(y->type)) {
@@ -2333,7 +2571,6 @@ static void propagate(environment_t *env) {
                                }
                        }
                }
-#endif
                split_by(Y, env);
        }
 }  /* propagate */
@@ -2347,8 +2584,9 @@ static ir_node *get_leader(node_t *node) {
        partition_t *part = node->part;
 
        if (part->n_leader > 1 || node->is_follower) {
-               if (node->is_follower)
+               if (node->is_follower) {
                        DB((dbg, LEVEL_2, "Replacing follower %+F\n", node->node));
+               }
                else
                        DB((dbg, LEVEL_2, "Found congruence class for %+F\n", node->node));
 
@@ -2391,7 +2629,7 @@ static int can_exchange(ir_node *pred) {
                return 1;
        }
        return 0;
-}
+}  /* can_exchange */
 
 /**
  * Block Post-Walker, apply the analysis results on control flow by
@@ -2404,26 +2642,55 @@ static void apply_cf(ir_node *block, void *ctx) {
        ir_node       **ins, **in_X;
        ir_node       *phi, *next;
 
-       if (block == get_irg_end_block(current_ir_graph) ||
-           block == get_irg_start_block(current_ir_graph)) {
+       n = get_Block_n_cfgpreds(block);
+
+       if (node->type.tv == tarval_unreachable) {
+               env->modified = 1;
+
+               for (i = n - 1; i >= 0; --i) {
+                       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);
+                                       }
+                               }
+                       }
+               }
+
                /* the EndBlock is always reachable even if the analysis
                   finds out the opposite :-) */
-               return;
-       }
-       if (node->type.tv == tarval_unreachable) {
-               /* mark dead blocks */
-               set_Block_dead(block);
+               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 */
+                       set_irn_in(block, 0, NULL);
+               }
                return;
        }
 
-       n = get_Block_n_cfgpreds(block);
-
        if (n == 1) {
                /* only one predecessor combine */
                ir_node *pred = skip_Proj(get_Block_cfgpred(block, 0));
 
                if (can_exchange(pred)) {
-                       exchange(block, get_nodes_block(pred));
+                       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);
+                       exchange(block, new_block);
+                       node->node = new_block;
                        env->modified = 1;
                }
                return;
@@ -2437,6 +2704,24 @@ static void apply_cf(ir_node *block, void *ctx) {
 
                if (node->type.tv == tarval_reachable) {
                        in_X[k++] = pred;
+               } 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);
+                                       }
+                               }
+                       }
                }
        }
        if (k >= n)
@@ -2455,6 +2740,7 @@ static void apply_cf(ir_node *block, void *ctx) {
                        set_irn_node(c, node);
                        node->node = c;
                        DB((dbg, LEVEL_1, "%+F is replaced by %+F\n", phi, c));
+                       DBG_OPT_COMBO(phi, c, FS_OPT_COMBO_CONST);
                        exchange(phi, c);
                        env->modified = 1;
                } else {
@@ -2466,13 +2752,16 @@ static void apply_cf(ir_node *block, void *ctx) {
                                        ins[j++] = get_Phi_pred(phi, i);
                                }
                        }
-                       if (j <= 1) {
+                       if (j == 1) {
                                /* this Phi is replaced by a single predecessor */
                                ir_node *s = ins[0];
+                               node_t *phi_node = get_irn_node(phi);
 
                                node->node = s;
                                DB((dbg, LEVEL_1, "%+F is replaced by %+F because of cf change\n", phi, s));
+                               DBG_OPT_COMBO(phi, s, FS_OPT_COMBO_FOLLOWER);
                                exchange(phi, s);
+                               phi_node->node = s;
                                env->modified = 1;
                        } else {
                                set_irn_in(phi, j, ins);
@@ -2481,12 +2770,15 @@ static void apply_cf(ir_node *block, void *ctx) {
                }
        }
 
-       if (k <= 1) {
+       if (k == 1) {
                /* this Block has only one live predecessor */
                ir_node *pred = skip_Proj(in_X[0]);
 
                if (can_exchange(pred)) {
-                       exchange(block, get_nodes_block(pred));
+                       ir_node *new_block = get_nodes_block(pred);
+                       DBG_OPT_COMBO(block, new_block, FS_OPT_COMBO_CF);
+                       exchange(block, new_block);
+                       node->node = new_block;
                        env->modified = 1;
                }
        } else {
@@ -2519,14 +2811,17 @@ static void apply_result(ir_node *irn, void *ctx) {
                        env->modified = 1;
                }
                else if (node->type.tv == tarval_unreachable) {
-                       ir_node *bad = get_irg_bad(current_ir_graph);
-
-                       /* see comment above */
-                       set_irn_node(bad, node);
-                       node->node = bad;
-                       DB((dbg, LEVEL_1, "%+F is unreachable\n", irn));
-                       exchange(irn, bad);
-                       env->modified = 1;
+                       /* don't kick away Unknown */
+                       if (! is_Unknown(irn)) {
+                               ir_node *bad = get_irg_bad(current_ir_graph);
+
+                               /* see comment above */
+                               set_irn_node(bad, node);
+                               node->node = bad;
+                               DB((dbg, LEVEL_1, "%+F is unreachable\n", irn));
+                               exchange(irn, bad);
+                               env->modified = 1;
+                       }
                }
                else if (get_irn_mode(irn) == mode_X) {
                        if (is_Proj(irn)) {
@@ -2537,11 +2832,12 @@ static void apply_result(ir_node *irn, void *ctx) {
                                        node_t *sel = get_irn_node(get_Cond_selector(cond));
 
                                        if (is_tarval(sel->type.tv) && tarval_is_constant(sel->type.tv)) {
-                                               /* Cond selector is a constant, make a Jmp */
-                                               ir_node *jmp = new_r_Jmp(current_ir_graph, block->node);
+                                               /* Cond selector is a constant and the Proj is reachable, make a Jmp */
+                                               ir_node *jmp  = new_r_Jmp(current_ir_graph, block->node);
                                                set_irn_node(jmp, node);
                                                node->node = jmp;
                                                DB((dbg, LEVEL_1, "%+F is replaced by %+F\n", irn, jmp));
+                                               DBG_OPT_COMBO(irn, jmp, FS_OPT_COMBO_CF);
                                                exchange(irn, jmp);
                                                env->modified = 1;
                                        }
@@ -2562,6 +2858,7 @@ static void apply_result(ir_node *irn, void *ctx) {
                                        set_irn_node(c, node);
                                        node->node = c;
                                        DB((dbg, LEVEL_1, "%+F is replaced by %+F\n", irn, c));
+                                       DBG_OPT_COMBO(irn, c, FS_OPT_COMBO_CONST);
                                        exchange(irn, c);
                                        env->modified = 1;
                                }
@@ -2573,6 +2870,7 @@ static void apply_result(ir_node *irn, void *ctx) {
                                        node->node = symc;
 
                                        DB((dbg, LEVEL_1, "%+F is replaced by %+F\n", irn, symc));
+                                       DBG_OPT_COMBO(irn, symc, FS_OPT_COMBO_CONST);
                                        exchange(irn, symc);
                                        env->modified = 1;
                                }
@@ -2583,6 +2881,10 @@ static void apply_result(ir_node *irn, void *ctx) {
 
                                if (leader != irn) {
                                        DB((dbg, LEVEL_1, "%+F from part%d is replaced by %+F\n", irn, node->part->nr, leader));
+                                       if (node->is_follower)
+                                               DBG_OPT_COMBO(irn, leader, FS_OPT_COMBO_FOLLOWER);
+                                       else
+                                               DBG_OPT_COMBO(irn, leader, FS_OPT_COMBO_CONGRUENT);
                                        exchange(irn, leader);
                                        env->modified = 1;
                                }
@@ -2606,17 +2908,11 @@ static void apply_end(ir_node *end, environment_t *env) {
                ir_node *ka   = get_End_keepalive(end, i);
                node_t  *node = get_irn_node(ka);
 
-               /* Use the is_flagged bit to mark already visited nodes.
-                * This should not be ready but better safe than sorry. */
-               if (node->is_flagged == 0) {
-                       node->is_flagged = 1;
+               if (! is_Block(ka))
+                       node = get_irn_node(get_nodes_block(ka));
 
-                       if (! is_Block(ka))
-                               node = get_irn_node(get_nodes_block(ka));
-
-                       if (node->type.tv != tarval_unreachable)
-                               in[j++] = ka;
-               }
+               if (node->type.tv != tarval_unreachable)
+                       in[j++] = ka;
        }
        if (j != n) {
                set_End_keepalives(end, j, in);
@@ -2646,6 +2942,7 @@ static void set_compute_functions(void) {
        SET(Phi);
        SET(Add);
        SET(Sub);
+       SET(Eor);
        SET(SymConst);
        SET(Cmp);
        SET(Proj);
@@ -2660,11 +2957,13 @@ static void set_compute_functions(void) {
 }  /* set_compute_functions */
 
 static int dump_partition_hook(FILE *F, ir_node *n, ir_node *local) {
+#ifdef DEBUG_libfirm
        ir_node *irn = local != NULL ? local : n;
        node_t *node = get_irn_node(irn);
 
        ir_fprintf(F, "info2 : \"partition %u type %+F\"\n", node->part->nr, node->type);
        return 1;
+#endif
 }
 
 void combo(ir_graph *irg) {
@@ -2693,9 +2992,11 @@ void combo(ir_graph *irg) {
        env.type2id_map    = pmap_create();
        env.end_idx        = get_opt_global_cse() ? 0 : -1;
        env.lambda_input   = 0;
+       env.nonstd_cond    = 0;
        env.modified       = 0;
 
        assure_irg_outs(irg);
+       assure_cf_loop(irg);
 
        /* we have our own value_of function */
        set_value_of_func(get_node_tarval);
@@ -2703,11 +3004,19 @@ void combo(ir_graph *irg) {
        set_compute_functions();
        DEBUG_ONLY(part_nr = 0);
 
+       ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
+
        /* create the initial partition and place it on the work list */
        env.initial = new_partition(&env);
        add_to_worklist(env.initial, &env);
        irg_walk_graph(irg, init_block_phis, create_initial_partitions, &env);
 
+#ifdef WITH_UNKNOWN
+       tarval_UNKNOWN = env.nonstd_cond ? tarval_bad : tarval_top;
+#else
+       tarval_UNKNOWN = tarval_bad;
+#endif
+
        /* all nodes on the initial partition have type Top */
        env.initial->type_is_T_or_C = 1;
 
@@ -2724,6 +3033,7 @@ void combo(ir_graph *irg) {
        } while (env.cprop != NULL || env.worklist != NULL);
 
        dump_all_partitions(&env);
+       check_all_partitions(&env);
 
 #if 0
        set_dump_node_vcgattr_hook(dump_partition_hook);
@@ -2746,6 +3056,8 @@ void combo(ir_graph *irg) {
                set_irg_loopinfo_inconsistent(irg);
        }
 
+       ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
+
        pmap_destroy(env.type2id_map);
        del_set(env.opcode2id_map);
        obstack_free(&env.obst, NULL);