becopyilp: Do not advertise the switch to dump the solution, because this is not...
[libfirm] / ir / be / bessaconstr.c
index f238720..768280a 100644 (file)
@@ -1,39 +1,25 @@
 /*
- * Copyright (C) 1995-2007 University of Karlsruhe.  All right reserved.
- *
  * This file is part of libFirm.
- *
- * This file may be distributed and/or modified under the terms of the
- * GNU General Public License version 2 as published by the Free Software
- * Foundation and appearing in the file LICENSE.GPL included in the
- * packaging of this file.
- *
- * Licensees holding valid libFirm Professional Edition licenses may use
- * this file in accordance with the libFirm Commercial License.
- * Agreement provided with the Software.
- *
- * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
- * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE.
+ * Copyright (C) 2012 University of Karlsruhe.
  */
 
 /**
  * @file
  * @brief       SSA construction for a set of nodes
- * @author      Sebastian Hack, Daniel Grund, Matthias Braun, Christian Wuerdig
+ * @author      Sebastian Hack, Daniel Grund, Matthias Braun, Christian Wuerdig,
+ *              Sebastian Buchwald
  * @date        04.05.2005
- * @version     $Id$
  *
  * The problem: Given a value and a set of "copies" that are known to
  * represent the same abstract value, rewire all usages of the original value
  * to their closest copy while introducing phis as necessary.
  *
  * Algorithm: Mark all blocks in the iterated dominance frontiers of the value
- * and it's copies. Link the copies ordered by dominance to the blocks.  The
- * we search for each use all all definitions in the current block, if none is
+ * and its copies. Link the copies ordered by dominance to the blocks.  Then
+ * we search for each use all definitions in the current block, if none is
  * found, then we search one in the immediate dominator. If we are in a block
- * of the dominance frontier, create a phi and search do the same search for
- * the phi arguments.
+ * of the dominance frontier, create a phi and do the same search for all
+ * phi arguments.
  *
  * A copy in this context means, that you want to introduce several new
  * abstract values (in Firm: nodes) for which you know, that they
  * This function reroutes all uses of the original value to the copies in the
  * corresponding dominance subtrees and creates Phi functions where necessary.
  */
-#ifdef HAVE_CONFIG_H
 #include "config.h"
-#endif
+
+/* statev in this file is extensive, so only enable if needed */
+#define DISABLE_STATEV
 
 #include "bessaconstr.h"
 #include "bemodule.h"
-#include "besched_t.h"
+#include "besched.h"
 #include "beintlive_t.h"
-#include "beirg_t.h"
+#include "beirg.h"
+#include "be_t.h"
+#include "benode.h"
 
 #include "debug.h"
 #include "error.h"
 #include "pdeq.h"
 #include "array.h"
 #include "irdom.h"
+#include "irnodeset.h"
 
 #include "ircons.h"
 #include "iredges_t.h"
+#include "statev_t.h"
 
 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
 
+static ir_node *search_def_end_of_block(be_ssa_construction_env_t *env,
+                                        ir_node *block);
+
+struct constr_info {
+       bool is_definition     : 1;
+       bool is_use            : 1;
+       bool already_processed : 1;
+       union {
+               /* Since we only consider scheduled nodes,
+                * this points to the real definition (e.g. a Proj). */
+               ir_node *definition;
+
+               /* Last definition of a block. */
+               ir_node *last_definition;
+       } u;
+};
+
+typedef struct constr_info constr_info;
+
+/**
+ * @return Whether the block contains a definition.
+ */
+static bool has_definition(const ir_node *block)
+{
+       return irn_visited(block);
+}
+
+static constr_info *get_or_set_info(be_ssa_construction_env_t *env,
+                                    const ir_node *node)
+{
+       constr_info *info = ir_nodemap_get(constr_info, &env->infos, node);
+       if (info == NULL) {
+               info = OALLOCZ(&env->obst, constr_info);
+               ir_nodemap_insert(&env->infos, node, info);
+       }
+       return info;
+}
+
+static constr_info *get_info(const be_ssa_construction_env_t *env,
+                             const ir_node *node)
+{
+       return ir_nodemap_get(constr_info, &env->infos, node);
+}
+
+/**
+ * @return Whether the block contains a use.
+ */
+static inline bool has_use(be_ssa_construction_env_t *env, ir_node *block)
+{
+       constr_info *info = get_or_set_info(env, block);
+       return info->is_use;
+}
+
+/**
+ * @return Whether the node is a definition.
+ */
+static bool is_definition(be_ssa_construction_env_t *env, ir_node *node)
+{
+       constr_info *info = get_info(env, node);
+       return info != NULL && info->is_definition;
+}
+
+/**
+ * Introduces a definition at the corresponding block.
+ */
+static void introduce_definition(be_ssa_construction_env_t *env, ir_node *def)
+{
+       ir_node     *block      = get_nodes_block(def);
+       constr_info *def_info   = get_or_set_info(env, def);
+       ir_node     *skip       = skip_Proj(def);
+       constr_info *skip_info  = get_or_set_info(env, skip);
+       constr_info *block_info = get_or_set_info(env, block);
+
+       DBG((dbg, LEVEL_2, "\tintroducing definition %+F in %+F\n", def, block));
+
+       def_info->is_definition = true;
+
+       skip_info->is_definition = true;
+       skip_info->u.definition  = def;
+
+       // Set the last definition if we only introduce one definition for the block
+       if (has_definition(block)) {
+               assert(!block_info->already_processed);
+               block_info->u.last_definition = NULL;
+       } else {
+               mark_irn_visited(block);
+               block_info->u.last_definition = def;
+       }
+}
+
+static void introduce_use(be_ssa_construction_env_t *env, ir_node *use)
+{
+       ir_node     *block      = get_nodes_block(use);
+       constr_info *info       = get_or_set_info(env, use);
+       constr_info *block_info = get_or_set_info(env, block);
+
+       DBG((dbg, LEVEL_2, "\tintroducing use %+F in %+F\n", use, block));
+
+       info->is_use       = true;
+       block_info->is_use = true;
+
+       waitq_put(env->worklist, use);
+}
+
 /**
  * Calculates the iterated dominance frontier of a set of blocks. Marks the
  * blocks as visited. Sets the link fields of the blocks in the dominance
  * frontier to the block itself.
  */
-static
-void mark_iterated_dominance_frontiers(const be_dom_front_info_t *domfronts,
-                                       waitq *worklist)
+static void mark_iterated_dominance_frontiers(
+                                           const be_ssa_construction_env_t *env)
 {
+       stat_ev_cnt_decl(blocks);
        DBG((dbg, LEVEL_3, "Dominance Frontier:"));
-       while(!pdeq_empty(worklist)) {
+       stat_ev_tim_push();
+       while (!waitq_empty(env->worklist)) {
                int i;
-               ir_node *block = waitq_get(worklist);
-               ir_node **domfront = be_get_dominance_frontier(domfronts, block);
+               ir_node  *block    = (ir_node*)waitq_get(env->worklist);
+               ir_node **domfront = ir_get_dominance_frontier(block);
                int domfront_len = ARR_LEN(domfront);
 
                for (i = 0; i < domfront_len; ++i) {
                        ir_node *y = domfront[i];
-                       if(Block_block_visited(y))
+                       if (Block_block_visited(y))
                                continue;
 
-                       if(!irn_visited(y)) {
+                       if (!irn_visited(y)) {
                                set_irn_link(y, NULL);
-                               waitq_put(worklist, y);
+                               waitq_put(env->worklist, y);
                        }
+
                        DBG((dbg, LEVEL_3, " %+F", y));
                        mark_Block_block_visited(y);
+                       stat_ev_cnt_inc(blocks);
                }
        }
+       stat_ev_tim_pop("bessaconstr_idf_time");
+       stat_ev_cnt_done(blocks, "bessaconstr_idf_blocks");
        DBG((dbg, LEVEL_3, "\n"));
 }
 
-static
-ir_node *search_def_end_of_block(be_ssa_construction_env_t *env,
-                                 ir_node *block);
-
-static
-ir_node *create_phi(be_ssa_construction_env_t *env, ir_node *block,
-                    ir_node *link_with)
+/**
+ * Inserts a new phi at the given block.
+ *
+ * The constructed phi has only Dummy operands,
+ * but can be used as definition for other nodes.
+ *
+ * @see fix_phi_arguments
+ */
+static ir_node *insert_dummy_phi(be_ssa_construction_env_t *env, ir_node *block)
 {
        int i, n_preds = get_Block_n_cfgpreds(block);
-       ir_graph *irg = get_irn_irg(block);
-       ir_node *phi;
-       ir_node **ins = alloca(n_preds * sizeof(ins[0]));
+       ir_graph *irg = get_Block_irg(block);
+       ir_node **ins = ALLOCAN(ir_node*, n_preds);
+       ir_node  *dummy;
+       ir_node  *phi;
 
-       assert(n_preds > 1);
+       DBG((dbg, LEVEL_3, "\t...create phi at block %+F\n", block));
 
-       for(i = 0; i < n_preds; ++i) {
-               ins[i] = new_r_Unknown(irg, env->mode);
-       }
-       phi = new_r_Phi(irg, block, n_preds, ins, env->mode);
-       if(env->new_phis != NULL) {
-               ARR_APP1(ir_node*, env->new_phis, phi);
-       }
+       assert(n_preds > 1);
 
-       if(env->mode != mode_M) {
-               sched_add_after(block, phi);
+       dummy = new_r_Dummy(irg, env->mode);
+       for (i = 0; i < n_preds; ++i) {
+               ins[i] = dummy;
        }
+       phi = be_new_Phi(block, n_preds, ins, env->mode, env->phi_req);
+       sched_add_after(block, phi);
+       ARR_APP1(ir_node*, env->new_phis, phi);
 
        DBG((dbg, LEVEL_2, "\tcreating phi %+F in %+F\n", phi, block));
-       set_irn_link(link_with, phi);
-       mark_irn_visited(block);
-
-       for(i = 0; i < n_preds; ++i) {
-               ir_node *pred_block = get_Block_cfgpred_block(block, i);
-               ir_node *pred_def   = search_def_end_of_block(env, pred_block);
+       introduce_definition(env, phi);
 
-               set_irn_n(phi, i, pred_def);
-       }
+       waitq_put(env->worklist, phi);
 
        return phi;
 }
 
-static
-ir_node *get_def_at_idom(be_ssa_construction_env_t *env, ir_node *block)
+/**
+ * @return Last definition of the immediate dominator.
+ */
+static ir_node *get_def_at_idom(be_ssa_construction_env_t *env, ir_node *block)
 {
        ir_node *dom = get_Block_idom(block);
        assert(dom != NULL);
+       DBG((dbg, LEVEL_3, "\t...continue at idom %+F\n", dom));
        return search_def_end_of_block(env, dom);
 }
 
-static
-ir_node *search_def_end_of_block(be_ssa_construction_env_t *env, ir_node *block)
+static ir_node *get_def_from_preds(be_ssa_construction_env_t *const env, ir_node *const block)
 {
-       if(irn_visited(block)) {
-               assert(get_irn_link(block) != NULL);
-               return get_irn_link(block);
-       } else if(Block_block_visited(block)) {
-               return create_phi(env, block, block);
+       /* Create a phi if the block is in the dominance frontier. */
+       if (Block_block_visited(block)) {
+               return insert_dummy_phi(env, block);
        } else {
-               ir_node *def = get_def_at_idom(env, block);
-               mark_irn_visited(block);
-               set_irn_link(block, def);
+               return get_def_at_idom(env, block);
+       }
+}
 
-               return def;
+/**
+ * Fixes all operands of a use.
+ *
+ * If an operand of the use is a (original) definition,
+ * it will be replaced by the given definition.
+ */
+static void set_operands(be_ssa_construction_env_t *env, ir_node *use, ir_node *def, constr_info *const use_info)
+{
+       int arity = get_irn_arity(use);
+       for (int i = 0; i < arity; ++i) {
+               ir_node *op = get_irn_n(use, i);
+
+               if (is_definition(env, op)) {
+                       DBG((dbg, LEVEL_1, "\t...%+F(%d) -> %+F\n", use, i, def));
+                       set_irn_n(use, i, def);
+               }
        }
+
+       use_info->already_processed = true;
 }
 
-static
-ir_node *search_def(be_ssa_construction_env_t *env, ir_node *at)
+/**
+ * Fixes all uses of the given block.
+ */
+static void process_block(be_ssa_construction_env_t *env, ir_node *block)
 {
-       ir_node *block = get_nodes_block(at);
-       ir_node *node;
-       ir_node *def;
+       ir_node     *def        = NULL;
+       constr_info *block_info = get_or_set_info(env, block);
 
-       DBG((dbg, LEVEL_3, "\t...searching def at %+F\n", at));
+       assert(has_definition(block));
+       assert(!block_info->already_processed && "Block already processed");
 
-       /* no defs in the current block we can do the normal searching */
-       if(!irn_visited(block) && !Block_block_visited(block)) {
-               DBG((dbg, LEVEL_3, "\t...continue at idom\n"));
-               return get_def_at_idom(env, block);
-       }
+       DBG((dbg, LEVEL_3, "\tprocessing block  %+F\n", block));
 
-       /* there are defs in the current block, walk the linked list to find
-          the one immediately dominating us
-        */
-       node = block;
-       def  = get_irn_link(node);
-       while(def != NULL) {
-               if(!value_dominates(at, def)) {
-                       DBG((dbg, LEVEL_3, "\t...found dominating def %+F\n", def));
-                       return def;
-               }
+       sched_foreach(block, node) {
+               constr_info *const info = get_info(env, node);
+               if (!info)
+                       continue;
 
-               node = def;
-               def  = get_irn_link(node);
-       }
+               if (info->is_use && !is_Phi(node)) {
+                       DBG((dbg, LEVEL_3, "\t...found use %+F\n", node));
 
-       /* block in dominance frontier? create a phi then */
-       if(Block_block_visited(block)) {
-               DBG((dbg, LEVEL_3, "\t...create phi at block %+F\n", block));
-               assert(!is_Phi(node));
-               return create_phi(env, block, node);
-       }
+                       if (def == NULL) {
+                               /* Create a phi if the block is in the dominance frontier. */
+                               def = get_def_from_preds(env, block);
+                       }
 
+                       set_operands(env, node, def, info);
+               }
+
+               if (info->is_definition) {
+                       def = info->u.definition;
+                       DBG((dbg, LEVEL_3, "\t...found definition %+F\n", def));
+               }
+       }
 
-       DBG((dbg, LEVEL_3, "\t...continue at idom (after checking block)\n"));
-       return get_def_at_idom(env, block);
+       block_info->already_processed = true;
+       block_info->u.last_definition = def;
 }
 
 /**
- * Adds a definition into the link field of the block. The definitions are
- * sorted by dominance. A non-visited block means no definition has been
- * inserted yet.
+ * @return Last definition of the given block.
  */
-static
-void introduce_def_at_block(ir_node *block, ir_node *def)
+static ir_node *search_def_end_of_block(be_ssa_construction_env_t *env,
+                                        ir_node *block)
 {
-       if(irn_visited(block)) {
-               ir_node *node = block;
-               ir_node *current_def;
-
-               while(1) {
-                       current_def = get_irn_link(node);
-                       if(current_def == def) {
-                               /* already in block */
-                               return;
+       constr_info *block_info      = get_or_set_info(env, block);
+       ir_node     *last_definition = block_info->u.last_definition;
+
+       if (last_definition != NULL)
+               return last_definition;
+
+       if (has_definition(block)) {
+               if (has_use(env, block)) {
+                       if (!block_info->already_processed) {
+                               process_block(env, block);
+                       }
+               }
+               else {
+                       /* Search the last definition of the block. */
+                       sched_foreach_reverse(block, def) {
+                               constr_info const *const info = get_info(env, def);
+                               if (info && info->is_definition) {
+                                       DBG((dbg, LEVEL_3, "\t...found definition %+F\n", info->u.definition));
+                                       block_info->u.last_definition = info->u.definition;
+                                       break;
+                               }
                        }
-                       if(current_def == NULL)
-                               break;
-                       if(value_dominates(current_def, def))
-                               break;
-                       node = current_def;
+
+                       assert(block_info->u.last_definition && "No definition found");
                }
 
-               set_irn_link(node, def);
-               set_irn_link(def, current_def);
+               return block_info->u.last_definition;
        } else {
-               set_irn_link(block, def);
-               set_irn_link(def, NULL);
-               mark_irn_visited(block);
+               ir_node *const def = get_def_from_preds(env, block);
+               block_info->u.last_definition = def;
+               return def;
        }
 }
 
-void be_ssa_construction_init(be_ssa_construction_env_t *env, be_irg_t *birg)
+/**
+ * Fixes all operands of the given use.
+ */
+static void search_def_at_block(be_ssa_construction_env_t *const env, ir_node *const use, constr_info *const info)
 {
-       ir_graph *irg = be_get_birg_irg(birg);
-       memset(env, 0, sizeof(env[0]));
+       ir_node     *block      = get_nodes_block(use);
+       constr_info *block_info = get_or_set_info(env, block);
+
+       if (block_info->already_processed)
+               return;
+
+       if (has_definition(block)) {
+               process_block(env, block);
+       } else {
+               ir_node *const def = get_def_from_preds(env, block);
+               set_operands(env, use, def, info);
+       }
+}
+
+void be_ssa_construction_init(be_ssa_construction_env_t *env, ir_graph *irg)
+{
+       stat_ev_ctx_push_fmt("bessaconstr", "%+F", irg);
+       stat_ev_tim_push();
 
-       be_assure_dom_front(birg);
+       stat_ev_dbl("bessaconstr_n_blocks", get_Block_dom_max_subtree_pre_num(get_irg_start_block(irg)));
+
+       memset(env, 0, sizeof(env[0]));
 
        env->irg       = irg;
-       env->domfronts = be_get_birg_dom_front(birg);
        env->new_phis  = NEW_ARR_F(ir_node*, 0);
        env->worklist  = new_waitq();
+       ir_nodemap_init(&env->infos, irg);
+       obstack_init(&env->obst);
 
-       set_using_visited(irg);
-       set_using_block_visited(irg);
-       set_using_irn_link(irg);
+       assure_irg_properties(env->irg,
+                             IR_GRAPH_PROPERTY_CONSISTENT_DOMINANCE_FRONTIERS);
+
+       ir_reserve_resources(irg, IR_RESOURCE_IRN_VISITED
+                       | IR_RESOURCE_BLOCK_VISITED | IR_RESOURCE_IRN_LINK);
 
        /* we use the visited flag to indicate blocks in the dominance frontier
         * and blocks that already have the relevant value at the end calculated */
        inc_irg_visited(irg);
        /* We use the block visited flag to indicate blocks in the dominance
-        * froniter of some values (and this potentially needing phis) */
+        * frontier of some values (and this potentially needing phis) */
        inc_irg_block_visited(irg);
 }
 
 void be_ssa_construction_destroy(be_ssa_construction_env_t *env)
 {
+       stat_ev_int("bessaconstr_phis", ARR_LEN(env->new_phis));
+       obstack_free(&env->obst, NULL);
+       ir_nodemap_destroy(&env->infos);
        del_waitq(env->worklist);
        DEL_ARR_F(env->new_phis);
 
-       clear_using_visited(env->irg);
-       clear_using_block_visited(env->irg);
-       clear_using_irn_link(env->irg);
+       ir_free_resources(env->irg, IR_RESOURCE_IRN_VISITED
+                       | IR_RESOURCE_BLOCK_VISITED | IR_RESOURCE_IRN_LINK);
+
+       stat_ev_tim_pop("bessaconstr_total_time");
+       stat_ev_ctx_pop("bessaconstr");
+}
+
+static void determine_phi_req(be_ssa_construction_env_t *env, ir_node *value)
+{
+       const arch_register_req_t *req   = arch_get_irn_register_req(value);
+       env->mode = get_irn_mode(value);
+       if (req->width == 1) {
+               env->phi_req = req->cls->class_req;
+       } else {
+               /* construct a new register req... */
+               ir_graph            *irg     = get_irn_irg(value);
+               struct obstack      *obst    = be_get_be_obst(irg);
+               arch_register_req_t *new_req = OALLOCZ(obst, arch_register_req_t);
+               new_req->cls   = req->cls;
+               new_req->type  = req->type & arch_register_req_type_aligned;
+               new_req->width = req->width;
+               env->phi_req = new_req;
+       }
 }
 
 void be_ssa_construction_add_copy(be_ssa_construction_env_t *env,
@@ -282,18 +444,18 @@ void be_ssa_construction_add_copy(be_ssa_construction_env_t *env,
 
        assert(env->iterated_domfront_calculated == 0);
 
-       if(env->mode == NULL) {
-               env->mode = get_irn_mode(copy);
+       if (env->mode == NULL) {
+               determine_phi_req(env, copy);
        } else {
                assert(env->mode == get_irn_mode(copy));
        }
 
        block = get_nodes_block(copy);
 
-       if(!irn_visited(block)) {
+       if (!has_definition(block)) {
                waitq_put(env->worklist, block);
        }
-       introduce_def_at_block(block, copy);
+       introduce_definition(env, copy);
 }
 
 void be_ssa_construction_add_copies(be_ssa_construction_env_t *env,
@@ -303,99 +465,137 @@ void be_ssa_construction_add_copies(be_ssa_construction_env_t *env,
 
        assert(env->iterated_domfront_calculated == 0);
 
-       if(env->mode == NULL) {
-               env->mode = get_irn_mode(copies[0]);
+       if (env->mode == NULL) {
+               determine_phi_req(env, copies[0]);
        }
 
-       for(i = 0; i < copies_len; ++i) {
-               ir_node *copy = copies[i];
+       for (i = 0; i < copies_len; ++i) {
+               ir_node *copy  = copies[i];
                ir_node *block = get_nodes_block(copy);
 
                assert(env->mode == get_irn_mode(copy));
-               if(!irn_visited(block)) {
+               if (!has_definition(block)) {
                        waitq_put(env->worklist, block);
                }
-               introduce_def_at_block(block, copy);
+               introduce_definition(env, copy);
        }
 }
 
-void be_ssa_construction_set_ignore_uses(be_ssa_construction_env_t *env,
-                                         const ir_nodeset_t *ignore_uses)
+ir_node **be_ssa_construction_get_new_phis(be_ssa_construction_env_t *env)
 {
-       env->ignore_uses = ignore_uses;
+       return env->new_phis;
 }
 
-ir_node **be_ssa_construction_get_new_phis(be_ssa_construction_env_t *env)
+/**
+ * Fixes all arguments of a newly constructed phi.
+ *
+ * @see insert_dummy_phi
+ */
+static void fix_phi_arguments(be_ssa_construction_env_t *const env, ir_node *const phi, constr_info *const info)
 {
-       return env->new_phis;
+       ir_node *block   = get_nodes_block(phi);
+       int      n_preds = get_Block_n_cfgpreds(block);
+
+       DBG((dbg, LEVEL_3, "\tfixing phi arguments  %+F\n", phi));
+
+       for (int i = 0; i < n_preds; ++i) {
+               ir_node *op = get_irn_n(phi, i);
+
+               if (is_definition(env, op) || is_Dummy(op)) {
+                       ir_node *pred_block = get_Block_cfgpred_block(block, i);
+                       ir_node *pred_def   = search_def_end_of_block(env, pred_block);
+
+                       DBG((dbg, LEVEL_1, "\t...%+F(%d) -> %+F\n", phi, i, pred_def));
+                       set_irn_n(phi, i, pred_def);
+               }
+       }
+
+       info->already_processed = true;
 }
 
-void be_ssa_construction_fix_users(be_ssa_construction_env_t *env,
-                                   ir_node *value)
+void be_ssa_construction_fix_users_array(be_ssa_construction_env_t *env,
+                                         ir_node **nodes, size_t nodes_len)
 {
-       const ir_edge_t *edge, *next;
+       size_t i;
+       stat_ev_cnt_decl(uses);
 
-       if(!env->iterated_domfront_calculated) {
-               mark_iterated_dominance_frontiers(env->domfronts, env->worklist);
+       be_timer_push(T_SSA_CONSTR);
+
+       if (!env->iterated_domfront_calculated) {
+               mark_iterated_dominance_frontiers(env);
                env->iterated_domfront_calculated = 1;
        }
 
-       /*
-        * Search the valid def for each use and set it.
-        */
-       foreach_out_edge_safe(value, edge, next) {
-               ir_node *use = get_edge_src_irn(edge);
-               ir_node *at  = use;
-               int pos      = get_edge_src_pos(edge);
-               ir_node *def;
-
-               if(env->ignore_uses != NULL     &&
-                  ir_nodeset_contains(env->ignore_uses, use))
-                       continue;
+       DBG((dbg, LEVEL_1, "\tfixing users array\n"));
+
+       assert(waitq_empty(env->worklist));
+
+       stat_ev_tim_push();
 
-               if(is_Phi(use)) {
-                       ir_node *block = get_nodes_block(use);
-                       ir_node *predblock = get_Block_cfgpred_block(block, pos);
-                       at = sched_last(predblock);
+       for (i = 0; i < nodes_len; ++i) {
+               ir_node *value = nodes[i];
+               DBG((dbg, LEVEL_3, "\tfixing users of %+F\n", value));
+               introduce_definition(env, value);
+
+               foreach_out_edge_safe(value, edge) {
+                       ir_node *const use = get_edge_src_irn(edge);
+                       if (is_Anchor(use) || is_End(use))
+                               continue;
+
+                       introduce_use(env, use);
                }
+       }
+
+       assert(!waitq_empty(env->worklist));
 
-               def = search_def(env, at);
+       while (!waitq_empty(env->worklist)) {
+               ir_node     *use  = (ir_node *)waitq_get(env->worklist);
+               constr_info *info = get_info(env, use);
 
-               if(def == NULL) {
-                       panic("no definition found for %+F at position %d\n", use, pos);
+               if (info->already_processed)
+                       continue;
+
+               if (is_Phi(use)) {
+                       fix_phi_arguments(env, use, info);
+               }
+               else {
+                       DBG((dbg, LEVEL_3, "\tsearching def for %+F at %+F\n", use, get_nodes_block(use)));
+                       search_def_at_block(env, use, info);
                }
 
-               DBG((dbg, LEVEL_2, "\t%+F(%d) -> %+F\n", use, pos, def));
-               set_irn_n(use, pos, def);
+               stat_ev_cnt_inc(uses);
        }
+
+       be_timer_pop(T_SSA_CONSTR);
+
+       stat_ev_tim_pop("bessaconstr_fix_time");
+       stat_ev_cnt_done(uses, "bessaconstr_uses");
 }
 
-void be_ssa_construction_fix_users_array(be_ssa_construction_env_t *env,
-                                         ir_node **nodes, size_t nodes_len)
+void be_ssa_construction_fix_users(be_ssa_construction_env_t *env, ir_node *value)
 {
-       size_t i;
-
-       for(i = 0; i < nodes_len; ++i) {
-               ir_node *node = nodes[i];
-               be_ssa_construction_fix_users(env, node);
-       }
+       be_ssa_construction_fix_users_array(env, &value, 1);
 }
 
+
 void be_ssa_construction_update_liveness_phis(be_ssa_construction_env_t *env,
                                               be_lv_t *lv)
 {
        int i, n;
 
+       be_timer_push(T_SSA_CONSTR);
+
        n = ARR_LEN(env->new_phis);
-       for(i = 0; i < n; ++i) {
+       for (i = 0; i < n; ++i) {
                ir_node *phi = env->new_phis[i];
                be_liveness_introduce(lv, phi);
        }
+
+       be_timer_pop(T_SSA_CONSTR);
 }
 
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_ssaconstr)
 void be_init_ssaconstr(void)
 {
        FIRM_DBG_REGISTER(dbg, "firm.be.ssaconstr");
 }
-
-BE_REGISTER_MODULE_CONSTRUCTOR(be_init_ssaconstr);