The big committ:
[libfirm] / ir / be / beirgmod.c
index 71b8da9..a2b2c1f 100644 (file)
@@ -1,13 +1,28 @@
+/**
+ * This file contains the following IRG modifications for be routines:
+ * - backend dominance information
+ * - SSA construction for a set of nodes
+ * - insertion of Perm nodes
+ * - empty block elimination
+ * - a simple dead node elimination (set inputs of unreachable nodes to BAD)
+ *
+ * Author:      Sebastian Hack, Daniel Grund, Matthias Braun, Christian Wuerdig
+ * Date:        04.05.2005
+ * Copyright:   (c) Universitaet Karlsruhe
+ * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
+ * CVS-Id:      $Id$
+ */
 #ifdef HAVE_CONFIG_H
-#include "config.h"
+#include <config.h>
 #endif
 
 #include <stdlib.h>
 
-#ifdef WIN32
-#include <malloc.h>
-#else
-#include <alloca.h>
+#ifdef HAVE_MALLOC_H
+ #include <malloc.h>
+#endif
+#ifdef HAVE_ALLOCA_H
+ #include <alloca.h>
 #endif
 
 #include "hashptr.h"
 #include "irdom_t.h"
 #include "iredges_t.h"
 #include "irgopt.h"
+#include "irprintf_t.h"
+#include "irgwalk.h"
 
 #include "be_t.h"
+#include "bechordal_t.h"
 #include "bearch.h"
 #include "besched_t.h"
 #include "belive_t.h"
 #include "benode_t.h"
 #include "beutil.h"
+#include "beinsn_t.h"
 
 #include "beirgmod.h"
 
-#define DBG_MODULE firm_dbg_register("firm.be.irgmod")
 #define DBG_LEVEL SET_LEVEL_0
+DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
+
+/*
+  ____                  _
+ |  _ \  ___  _ __ ___ (_)_ __   __ _ _ __   ___ ___
+ | | | |/ _ \| '_ ` _ \| | '_ \ / _` | '_ \ / __/ _ \
+ | |_| | (_) | | | | | | | | | | (_| | | | | (_|  __/
+ |____/ \___/|_| |_| |_|_|_| |_|\__,_|_| |_|\___\___|
+ |  ___| __ ___  _ __ | |_(_) ___ _ __ ___
+ | |_ | '__/ _ \| '_ \| __| |/ _ \ '__/ __|
+ |  _|| | | (_) | | | | |_| |  __/ |  \__ \
+ |_|  |_|  \___/|_| |_|\__|_|\___|_|  |___/
 
-struct _dom_front_info_t {
-  pmap *df_map;
+*/
+
+/**
+ * The dominance frontier for a graph.
+ */
+struct _be_dom_front_info_t {
+       pmap *df_map;         /**< A map, mapping every block to a list of its dominance frontier blocks. */
+       struct obstack obst;  /**< An obstack holding all the frontier data. */
 };
 
 /**
@@ -52,151 +88,178 @@ struct _dom_front_info_t {
  */
 static INLINE ir_node *get_idom(ir_node *bl)
 {
-  ir_node *idom = get_Block_idom(bl);
-  return idom == NULL ? bl : idom;
+       ir_node *idom = get_Block_idom(bl);
+       return idom == NULL ? bl : idom;
 }
 
-static void compute_df(ir_node *n, pmap *df_map)
+/**
+ * Compute the dominance frontier for a given block.
+ *
+ * @param blk   the block where the calculation starts
+ *
+ * @return the list of all blocks in the dominance frontier of blk
+ */
+static ir_node **compute_df(ir_node *blk, be_dom_front_info_t *info)
 {
-  ir_node *c;
-  const ir_edge_t *edge;
-  pset *df = pset_new_ptr_default();
-
-  /* Add local dominance frontiers */
-  foreach_block_succ(n, edge) {
-    ir_node *y = edge->src;
-
-    if(get_idom(y) != n)
-      pset_insert_ptr(df, y);
-  }
-
-  /*
-   * Go recursively down the dominance tree and add all blocks
-   * int the dominance frontiers of the children, which are not
-   * dominated by the given block.
-   */
-  for(c = get_Block_dominated_first(n); c; c = get_Block_dominated_next(c)) {
-    pset *df_c;
-    ir_node *w;
-
-    compute_df(c, df_map);
-    df_c = pmap_get(df_map, c);
-
-    for(w = pset_first(df_c); w; w = pset_next(df_c)) {
-      if(get_idom(w) != n)
-        pset_insert_ptr(df, w);
-    }
-  }
-
-  pmap_insert(df_map, n, df);
+       ir_node *c;
+       const ir_edge_t *edge;
+       ir_node **df_list = NEW_ARR_F(ir_node *, 0);
+       ir_node **df;
+       int len;
+
+       /* Add local dominance frontiers */
+       foreach_block_succ(blk, edge) {
+               ir_node *y = edge->src;
+
+               if (get_idom(y) != blk) {
+                       ARR_APP1(ir_node *, df_list, y);
+               }
+       }
 
+       /*
+        * Go recursively down the dominance tree and add all blocks
+        * into the dominance frontiers of the children, which are not
+        * dominated by the given block.
+        */
+       for (c = get_Block_dominated_first(blk); c; c = get_Block_dominated_next(c)) {
+               int i;
+               ir_node **df_c_list = compute_df(c, info);
+
+               for (i = ARR_LEN(df_c_list) - 1; i >= 0; --i) {
+                       ir_node *w = df_c_list[i];
+                       if (get_idom(w) != blk)
+                               ARR_APP1(ir_node *, df_list, w);
+               }
+       }
+
+       /* now copy the flexible array to the obstack */
+       len = ARR_LEN(df_list);
+       df = NEW_ARR_D(ir_node *, &info->obst, len);
+       memcpy(df, df_list, len * sizeof(df[0]));
+       DEL_ARR_F(df_list);
+
+       pmap_insert(info->df_map, blk, df);
+       return df;
 }
 
-dom_front_info_t *be_compute_dominance_frontiers(ir_graph *irg)
+be_dom_front_info_t *be_compute_dominance_frontiers(ir_graph *irg)
 {
-  dom_front_info_t *info = malloc(sizeof(*info));
+       be_dom_front_info_t *info = xmalloc(sizeof(*info));
 
-  edges_assure(irg);
-  info->df_map = pmap_create();
-  compute_doms(irg);
-  compute_df(get_irg_start_block(irg), info->df_map);
+       edges_assure(irg);
+       obstack_init(&info->obst);
+       info->df_map = pmap_create();
+       assure_doms(irg);
+       (void)compute_df(get_irg_start_block(irg), info);
 
-  return info;
+       return info;
 }
 
-void be_free_dominance_frontiers(dom_front_info_t *info)
+void be_free_dominance_frontiers(be_dom_front_info_t *info)
 {
-  pmap_entry *ent;
-
-  for(ent = pmap_first(info->df_map); ent; ent = pmap_next(info->df_map))
-    del_pset(ent->value);
-
-  pmap_destroy(info->df_map);
-  free(info);
+       obstack_free(&info->obst, NULL);
+       pmap_destroy(info->df_map);
+       free(info);
 }
 
-pset *be_get_dominance_frontier(dom_front_info_t *info, ir_node *block)
+/* Get the dominance frontier of a block. */
+ir_node **be_get_dominance_frontier(be_dom_front_info_t *info, ir_node *block)
 {
-  return pmap_get(info->df_map, block);
+       return pmap_get(info->df_map, block);
 }
 
-static void determine_phi_blocks(pset *copies, pset* copy_blocks, pset *phi_blocks, dom_front_info_t *df_info)
+static void determine_phi_blocks(pset *copies, pset *copy_blocks, pset *phi_blocks, be_dom_front_info_t *df_info)
 {
        ir_node *bl;
-       pdeq *worklist = new_pdeq();
-       firm_dbg_module_t *dbg = DBG_MODULE;
+       waitq *worklist = new_waitq();
 
        /*
-       * Fill the worklist queue and the rest of the orig blocks array.
-       */
-       for(bl = pset_first(copy_blocks); bl; bl = pset_next(copy_blocks)) {
-               pdeq_putr(worklist, bl);
+        * Fill the worklist queue and the rest of the orig blocks array.
+        */
+       for (bl = pset_first(copy_blocks); bl; bl = pset_next(copy_blocks)) {
+               waitq_put(worklist, bl);
        }
 
-       while(!pdeq_empty(worklist)) {
-               ir_node *bl = pdeq_getl(worklist);
-               pset *df    = be_get_dominance_frontier(df_info, bl);
+       while (!pdeq_empty(worklist)) {
+               ir_node *bl  = waitq_get(worklist);
+               ir_node **df = be_get_dominance_frontier(df_info, bl);
+               int i;
 
                ir_node *y;
 
                DBG((dbg, LEVEL_3, "dom front of %+F\n", bl));
-               for(y = pset_first(df); y; y = pset_next(df))
-                       DBG((dbg, LEVEL_3, "\t%+F\n", y));
-
-               for(y = pset_first(df); y; y = pset_next(df)) {
-                       if(!pset_find_ptr(phi_blocks, y)) {
+               DEBUG_ONLY(
+                       for (i = ARR_LEN(df) - 1; i >= 0; --i)
+                               DBG((dbg, LEVEL_3, "\t%+F\n", df[i]))
+               );
+
+               for (i = ARR_LEN(df) - 1; i >= 0; --i) {
+                       y = df[i];
+                       if (!pset_find_ptr(phi_blocks, y)) {
                                pset_insert_ptr(phi_blocks, y);
 
                                /*
-                               * Clear the link field of a possible phi block, since
-                               * the possibly created phi will be stored there. See,
-                               * search_def()
-                               */
+                                * Clear the link field of a possible phi block, since
+                                * the possibly created phi will be stored there. See,
+                                * search_def()
+                                */
                                set_irn_link(y, NULL);
 
                                if(!pset_find_ptr(copy_blocks, y))
-                                       pdeq_putr(worklist, y);
-
+                                       waitq_put(worklist, y);
                        }
                }
        }
 
-       del_pdeq(worklist);
+       del_waitq(worklist);
 }
 
+/*
+  ____ ____    _
+ / ___/ ___|  / \
+ \___ \___ \ / _ \
+  ___) |__) / ___ \
+ |____/____/_/   \_\
+   ____                _                   _   _
+  / ___|___  _ __  ___| |_ _ __ _   _  ___| |_(_) ___  _ __
+ | |   / _ \| '_ \/ __| __| '__| | | |/ __| __| |/ _ \| '_ \
+ | |__| (_) | | | \__ \ |_| |  | |_| | (__| |_| | (_) | | | |
+  \____\___/|_| |_|___/\__|_|   \__,_|\___|\__|_|\___/|_| |_|
+
+*/
+
 /**
  * Find the copy of the given original node whose value is 'active'
  * at a usage.
  *
  * The usage is given as a node and a position. Initially, the given operand
  * points to a node for which copies were introduced. We have to find
- * the valid copy for this usage. This is done by travering the
+ * the valid copy for this usage. This is done by traversing the
  * dominance tree upwards. If the usage is a phi function, we start
  * traversing from the predecessor block which corresponds to the phi
  * usage.
  *
- * @param usage The node which uses the original node.
- * @param pos The number of the argument which corresponds to the
- * original node.
- * @param copy_blocks A set containing all basic block in which copies
- * of the original node are located.
- * @param copies A set containing all node which are copies from the
- * original node.
- * @return The valid copy for usage.
+ * @param usage       The node which uses the original node.
+ * @param pos         The position of the argument which corresponds to the original node.
+ * @param copies      A set containing all node which are copies from the original node.
+ * @param copy_blocks A set containing all basic block in which copies of the original node are located.
+ * @param phis        A set where all created phis are recorded.
+ * @param phi_blocks  A set of all blocks where Phis shall be inserted (iterated dominance frontier).
+ * @param mode        The mode for the Phi if one has to be created.
+ * @return            The valid copy for usage.
  */
-static ir_node *search_def(ir_node *usage, int pos, pset *copies, pset *copy_blocks, pset *phi_blocks, ir_mode *mode)
+static ir_node *search_def(ir_node *usage, int pos, pset *copies, pset *copy_blocks, pset *phis, pset *phi_blocks, ir_mode *mode)
 {
        ir_node *curr_bl;
        ir_node *start_irn;
-       firm_dbg_module_t *dbg = DBG_MODULE;
 
        curr_bl = get_nodes_block(usage);
 
        DBG((dbg, LEVEL_1, "Searching valid def for use %+F at pos %d\n", usage, pos));
        /*
-       * If the usage is in a phi node, search the copy in the
-       * predecessor denoted by pos.
-       */
+        * If the usage is in a phi node, search the copy in the
+        * predecessor denoted by pos.
+        */
        if(is_Phi(usage)) {
                curr_bl = get_Block_cfgpred_block(curr_bl, pos);
                start_irn = sched_last(curr_bl);
@@ -209,10 +272,12 @@ static ir_node *search_def(ir_node *usage, int pos, pset *copies, pset *copy_blo
         * predecessor block of the usage.
         */
        while(curr_bl != NULL) {
+               ir_node *phim;
 
            /*
                 * If this block contains a copy, search the block
-                * instruction by instruction.
+                * instruction by instruction. If nothing is found
+                * search for a not scheduled PhiM.
                 */
                if(pset_find_ptr(copy_blocks, curr_bl)) {
                        ir_node *irn;
@@ -224,31 +289,54 @@ static ir_node *search_def(ir_node *usage, int pos, pset *copies, pset *copy_blo
                                if(pset_find_ptr(copies, irn))
                                        return irn;
                        }
+
+                       for(phim = pset_first(copies); phim; phim = pset_next(copies)) {
+                               if(!is_Phi(phim) || !(get_irn_mode(phim) == mode_M))
+                                       continue;
+
+                               if(get_nodes_block(phim) == curr_bl) {
+                                       pset_break(copies);
+                                       return phim;
+                               }
+                       }
                }
 
                if(pset_find_ptr(phi_blocks, curr_bl)) {
                        ir_node *phi = get_irn_link(curr_bl);
 
-                       if(!phi) {
+                       if(phi == NULL) {
                                int i, n_preds = get_irn_arity(curr_bl);
                                ir_graph *irg = get_irn_irg(curr_bl);
-                               ir_node **ins = malloc(n_preds * sizeof(ins[0]));
+                               ir_node **ins = alloca(n_preds * sizeof(ins[0]));
 
                                for(i = 0; i < n_preds; ++i)
-                                       ins[i] = new_r_Unknown(irg, mode);
+                                       ins[i] = new_r_Bad(irg);
 
                                phi = new_r_Phi(irg, curr_bl, n_preds, ins, mode);
                                DBG((dbg, LEVEL_2, "\tcreating phi %+F in %+F\n", phi, curr_bl));
 
                                set_irn_link(curr_bl, phi);
-                               sched_add_after(curr_bl, phi);
-                               free(ins);
+                               if(mode != mode_M)
+                                       sched_add_after(curr_bl, phi);
 
                                for(i = 0; i < n_preds; ++i) {
-                                       ir_node *arg = search_def(phi, i, copies, copy_blocks, phi_blocks, mode);
+                                       ir_node *arg = search_def(phi, i, copies, copy_blocks, phis, phi_blocks, mode);
+                                       if(arg == NULL) {
+                                               ir_node *irn;
+
+                                               ir_fprintf(stderr, "no definition found for %+F at position %d\nCopies: ", phi, i);
+                                               for(irn = pset_first(copies); irn; irn = pset_next(copies)) {
+                                                       ir_fprintf(stderr, "%+F ", irn);
+                                               }
+                                               ir_fprintf(stderr, "\n\n");
+                                               assert(arg && "no definition found");
+                                       }
                                        DBG((dbg, LEVEL_2, "\t\t%+F(%d) -> %+F\n", phi, i, arg));
                                        set_irn_n(phi, i, arg);
                                }
+
+                               if(phis != NULL)
+                                       pset_insert_ptr(phis, phi);
                        }
 
                        return phi;
@@ -263,15 +351,12 @@ static ir_node *search_def(ir_node *usage, int pos, pset *copies, pset *copy_blo
        return NULL;
 }
 
-static void fix_usages(pset *copies, pset *copy_blocks, pset *phi_blocks, pset *ignore_uses)
+static void fix_usages(pset *copies, pset *copy_blocks, pset *phi_blocks, pset *phis, pset *ignore_uses)
 {
-       firm_dbg_module_t *dbg = DBG_MODULE;
-       int n_outs             = 0;
-
+       int n_outs = 0;
        struct obstack obst;
        ir_node *irn;
        int i;
-
        struct out {
                ir_node *irn;
                int pos;
@@ -280,16 +365,18 @@ static void fix_usages(pset *copies, pset *copy_blocks, pset *phi_blocks, pset *
        obstack_init(&obst);
 
        /*
-       * Put all outs into an array.
-       * This is necessary, since the outs would be modified while
-       * iterating on them what could bring the outs module in trouble.
-       */
-       for(irn = pset_first(copies); irn; irn = pset_next(copies)) {
+        * Put all outs into an array.
+        * This is necessary, since the outs would be modified while
+        * iterating on them what could bring the outs module in trouble.
+        */
+       for (irn = pset_first(copies); irn; irn = pset_next(copies)) {
                const ir_edge_t *edge;
                foreach_out_edge(irn, edge) {
-                       if(!pset_find_ptr(ignore_uses, get_edge_src_irn(edge))) {
+                       ir_node *src = get_edge_src_irn(edge);
+                       /* ignore all users from ignore_uses or keep-alives (user is End node) */
+                       if (! pset_find_ptr(ignore_uses, src) && ! is_End(src)) {
                                struct out tmp;
-                               tmp.irn = get_edge_src_irn(edge);
+                               tmp.irn = src;
                                tmp.pos = get_edge_src_pos(edge);
                                obstack_grow(&obst, &tmp, sizeof(tmp));
                                n_outs++;
@@ -304,20 +391,28 @@ static void fix_usages(pset *copies, pset *copy_blocks, pset *phi_blocks, pset *
        for(i = 0; i < n_outs; ++i) {
                ir_node *irn  = outs[i].irn;
                int pos       = outs[i].pos;
-               ir_mode *mode = get_irn_mode(irn);
+               ir_mode *mode = get_irn_mode(get_irn_n(irn, pos));
 
                ir_node *def;
 
-               def = search_def(irn, pos, copies, copy_blocks, phi_blocks, mode);
+               def = search_def(irn, pos, copies, copy_blocks, phis, phi_blocks, mode);
                DBG((dbg, LEVEL_2, "\t%+F(%d) -> %+F\n", irn, pos, def));
 
-               if(def != NULL)
-                       set_irn_n(irn, pos, def);
+               if(def == NULL) {
+                       ir_fprintf(stderr, "no definition found for %+F at position %d\nCopies: ", irn, pos);
+                       for(irn = pset_first(copies); irn; irn = pset_next(copies)) {
+                               ir_fprintf(stderr, "%+F ", irn);
+                       }
+                       ir_fprintf(stderr, "\n\n");
+                       assert(def && "no definition found");
+               }
+               set_irn_n(irn, pos, def);
        }
 
        obstack_free(&obst, NULL);
 }
 
+#if 0
 /**
  * Remove phis which are not necessary.
  * During place_phi_functions() phi functions are put on the dominance
@@ -330,57 +425,72 @@ static void fix_usages(pset *copies, pset *copy_blocks, pset *phi_blocks, pset *
  */
 static void remove_odd_phis(pset *copies, pset *unused_copies)
 {
-  ir_node *irn;
-
-  for(irn = pset_first(copies); irn; irn = pset_next(copies)) {
-    if(is_Phi(irn)) {
-      int i, n;
-      int illegal = 0;
-
-      assert(sched_is_scheduled(irn) && "phi must be scheduled");
-      for(i = 0, n = get_irn_arity(irn); i < n && !illegal; ++i)
-        illegal = get_irn_n(irn, i) == NULL;
+       ir_node *irn;
 
-      if(illegal)
-        sched_remove(irn);
-    }
-  }
+       for(irn = pset_first(copies); irn; irn = pset_next(copies)) {
+               if(is_Phi(irn)) {
+                       int i, n;
+                       int illegal = 0;
+
+                       assert(sched_is_scheduled(irn) && "phi must be scheduled");
+                       for(i = 0, n = get_irn_arity(irn); i < n && !illegal; ++i)
+                               illegal = get_irn_n(irn, i) == NULL;
+
+                       if(illegal) {
+                               for(i = 0, n = get_irn_arity(irn); i < n; ++i)
+                                       set_irn_n(irn, i, new_Bad());
+                               sched_remove(irn);
+                       }
+               }
+       }
 
-  for(irn = pset_first(unused_copies); irn; irn = pset_next(unused_copies)) {
+       for(irn = pset_first(unused_copies); irn; irn = pset_next(unused_copies)) {
+               for(i = 0, n = get_irn_arity(irn); i < n; ++i)
+                       set_irn_n(irn, i, new_Bad());
                sched_remove(irn);
        }
 }
+#endif /* if 0 */
 
-void be_ssa_constr_ignore(dom_front_info_t *info, int n, ir_node *nodes[], pset *ignore_uses)
+void be_ssa_constr_phis_ignore(be_dom_front_info_t *info, be_lv_t *lv, int n, ir_node *nodes[], pset *phis, pset *ignore_uses)
 {
        pset *irns = pset_new_ptr(n);
        int i;
 
        for(i = 0; i < n; ++i)
                pset_insert_ptr(irns, nodes[i]);
-       be_ssa_constr_set_ignore(info, irns, ignore_uses);
+       be_ssa_constr_set_phis_ignore(info, lv, irns, phis, ignore_uses);
        del_pset(irns);
 }
 
-void be_ssa_constr(dom_front_info_t *info, int n, ir_node *nodes[])
+void be_ssa_constr_ignore(be_dom_front_info_t *info, be_lv_t *lv, int n, ir_node *nodes[], pset *ignore_uses)
+{
+       be_ssa_constr_phis_ignore(info, lv, n, nodes, NULL, ignore_uses);
+}
+
+void be_ssa_constr(be_dom_front_info_t *info, be_lv_t *lv, int n, ir_node *nodes[])
 {
        pset *empty_set = be_empty_set();
-       assert(pset_count(empty_set) == 0);
-       be_ssa_constr_ignore(info, n, nodes, empty_set);
+       be_ssa_constr_ignore(info, lv, n, nodes, empty_set);
 }
 
-void be_ssa_constr_set_ignore(dom_front_info_t *df, pset *nodes, pset *ignore_uses)
+void be_ssa_constr_set_phis_ignore(be_dom_front_info_t *df, be_lv_t *lv, pset *nodes, pset *phis, pset *ignore_uses)
 {
        int n                  = pset_count(nodes);
        pset *blocks           = pset_new_ptr(n);
        pset *phi_blocks       = pset_new_ptr(n);
        int save_optimize      = get_optimize();
        int save_normalize     = get_opt_normalize();
-       firm_dbg_module_t *dbg = DBG_MODULE;
+       int phis_set_created   = 0;
 
        ir_node *irn;
 
-       firm_dbg_set_mask(dbg, DBG_LEVEL);
+       /* We need to collect the phi functions to compute their liveness. */
+       if(lv && !phis) {
+               phis_set_created = 1;
+               phis = pset_new_ptr_default();
+       }
+
        DBG((dbg, LEVEL_1, "Introducing following copies for:\n"));
 
        /* Fill the sets. */
@@ -391,17 +501,17 @@ void be_ssa_constr_set_ignore(dom_front_info_t *df, pset *nodes, pset *ignore_us
        }
 
        /*
-       * Disable optimization so that the phi functions do not
-       * disappear.
-       */
+        * Disable optimization so that the phi functions do not
+        * disappear.
+        */
        set_optimize(0);
        set_opt_normalize(0);
 
        /*
-       * Place the phi functions and reroute the usages.
-       */
+        * Place the phi functions and reroute the usages.
+        */
        determine_phi_blocks(nodes, blocks, phi_blocks, df);
-       fix_usages(nodes, blocks, phi_blocks, ignore_uses);
+       fix_usages(nodes, blocks, phi_blocks, phis, ignore_uses);
 
        /* reset the optimizations */
        set_optimize(save_optimize);
@@ -410,12 +520,206 @@ void be_ssa_constr_set_ignore(dom_front_info_t *df, pset *nodes, pset *ignore_us
        del_pset(phi_blocks);
        del_pset(blocks);
 
+       /* Recompute the liveness (if wanted) of the original nodes, the copies and the inserted phis. */
+       if(lv) {
+#if 1
+               foreach_pset(nodes, irn)
+                       be_liveness_update(lv, irn);
+
+               foreach_pset(phis, irn)
+                       be_liveness_introduce(lv, irn);
+#else
+               be_liveness_recompute(lv);
+#endif
+       }
+
+       /* Free the phi set of we created it. */
+       if(phis_set_created)
+               del_pset(phis);
+
+}
+
+void be_ssa_constr_set_phis(be_dom_front_info_t *df, be_lv_t *lv, pset *nodes, pset *phis)
+{
+       pset *empty_set = be_empty_set();
+       be_ssa_constr_set_phis_ignore(df, lv, nodes, phis, empty_set);
+}
+
+void be_ssa_constr_set_ignore(be_dom_front_info_t *df, be_lv_t *lv, pset *nodes, pset *ignore_uses)
+{
+       be_ssa_constr_set_phis_ignore(df, lv, nodes, NULL, ignore_uses);
 }
 
-void be_ssa_constr_set(dom_front_info_t *info, pset *nodes)
+void be_ssa_constr_set(be_dom_front_info_t *info, be_lv_t *lv, pset *nodes)
 {
        pset *empty_set = be_empty_set();
+       be_ssa_constr_set_ignore(info, lv, nodes, empty_set);
+}
+
+/*
+  ___                     _     ____
+ |_ _|_ __  ___  ___ _ __| |_  |  _ \ ___ _ __ _ __ ___
+  | || '_ \/ __|/ _ \ '__| __| | |_) / _ \ '__| '_ ` _ \
+  | || | | \__ \  __/ |  | |_  |  __/  __/ |  | | | | | |
+ |___|_| |_|___/\___|_|   \__| |_|   \___|_|  |_| |_| |_|
+
+*/
+
+ir_node *insert_Perm_after(const arch_env_t *arch_env,
+                                                  be_lv_t *lv,
+                                                  const arch_register_class_t *cls,
+                                                  be_dom_front_info_t *dom_front,
+                                                  ir_node *pos)
+{
+       ir_node *bl     = is_Block(pos) ? pos : get_nodes_block(pos);
+       ir_graph *irg   = get_irn_irg(bl);
+       pset *live      = pset_new_ptr_default();
+
+       ir_node *curr, *irn, *perm, **nodes;
+       int i, n;
+
+       DBG((dbg, LEVEL_1, "Insert Perm after: %+F\n", pos));
+
+       be_liveness_nodes_live_at(lv, arch_env, cls, pos, live);
+
+       n = pset_count(live);
+
+       if(n == 0) {
+               del_pset(live);
+               return NULL;
+       }
+
+       nodes = xmalloc(n * sizeof(nodes[0]));
+
+       DBG((dbg, LEVEL_1, "live:\n"));
+       for(irn = pset_first(live), i = 0; irn; irn = pset_next(live), i++) {
+               DBG((dbg, LEVEL_1, "\t%+F\n", irn));
+               nodes[i] = irn;
+       }
+       del_pset(live);
+
+       perm = be_new_Perm(cls, irg, bl, n, nodes);
+       sched_add_after(pos, perm);
+       free(nodes);
+
+       curr = perm;
+       for (i = 0; i < n; ++i) {
+               ir_node *copies[2];
+               ir_node *perm_op = get_irn_n(perm, i);
+               const arch_register_t *reg = arch_get_irn_register(arch_env, perm_op);
+
+               ir_mode *mode = get_irn_mode(perm_op);
+               ir_node *proj = new_r_Proj(irg, bl, perm, mode, i);
+               arch_set_irn_register(arch_env, proj, reg);
+
+               sched_add_after(curr, proj);
+               curr = proj;
+
+               copies[0] = perm_op;
+               copies[1] = proj;
+
+               be_ssa_constr(dom_front, lv, 2, copies);
+       }
 
-       assert(pset_count(empty_set) == 0);
-       be_ssa_constr_set_ignore(info, nodes, empty_set);
+       return perm;
 }
+
+struct _elr_closure_t {
+       struct obstack obst;
+       const be_chordal_env_t *cenv;
+};
+
+static void elr_split_walker(ir_node *bl, void *data)
+{
+       struct _elr_closure_t *c     = data;
+       const be_chordal_env_t *cenv = c->cenv;
+       const arch_env_t *aenv       = cenv->birg->main_env->arch_env;
+       be_lv_t *lv                  = cenv->birg->lv;
+       be_dom_front_info_t *dom_front = cenv->birg->dom_front;
+       be_insn_t *insn;
+       be_insn_env_t ie;
+
+       be_insn_env_init(&ie, cenv->birg, cenv->cls, &c->obst);
+
+       for(insn = be_scan_insn(&ie, sched_first(bl)); !is_Block(insn->irn); insn = be_scan_insn(&ie, insn->next_insn)) {
+               ir_node *pred = sched_prev(insn->irn);
+               if(!is_Block(pred) && !is_Phi(insn->irn))
+                       insert_Perm_after(aenv, lv, cenv->cls, dom_front, insn->irn);
+       }
+}
+
+void extreme_liverange_splitting(struct _be_chordal_env_t *cenv)
+{
+       struct _elr_closure_t c;
+       be_lv_t *lv = cenv->birg->lv;
+
+       c.cenv = cenv;
+       obstack_init(&c.obst);
+       be_liveness_recompute(lv);
+       irg_block_walk_graph(cenv->irg, elr_split_walker, NULL, &c);
+       be_liveness_recompute(lv);
+       obstack_free(&c.obst, NULL);
+}
+
+/**
+ * Post-block-walker: Find blocks containing only one jump and
+ * remove them.
+ */
+static void remove_empty_block(ir_node *block, void *data) {
+       const ir_edge_t *edge, *next;
+       ir_node *node;
+       int *changed = data;
+       ir_node *jump = NULL;
+
+       assert(is_Block(block));
+
+       if (get_Block_n_cfgpreds(block) != 1)
+               return;
+
+       sched_foreach(block, node) {
+               if (! is_Jmp(node))
+                       return;
+               if (jump != NULL) {
+                       /* we should never have 2 jumps in a block */
+                       assert(0 && "We should never have 2 jumps in a block");
+                       return;
+               }
+               jump = node;
+       }
+
+       if (jump == NULL)
+               return;
+
+       node = get_Block_cfgpred(block, 0);
+       foreach_out_edge_safe(jump, edge, next) {
+               ir_node *block = get_edge_src_irn(edge);
+               int     pos    = get_edge_src_pos(edge);
+
+               set_irn_n(block, pos, node);
+       }
+
+       set_Block_cfgpred(block, 0, new_Bad());
+       sched_remove(jump);
+       *changed = 1;
+}
+
+/* removes basic blocks that just contain a jump instruction */
+int be_remove_empty_blocks(ir_graph *irg) {
+       int changed = 0;
+
+       irg_block_walk_graph(irg, remove_empty_block, NULL, &changed);
+       if (changed) {
+               /* invalidate analysis info */
+               set_irg_doms_inconsistent(irg);
+               set_irg_extblk_inconsistent(irg);
+               set_irg_outs_inconsistent(irg);
+       }
+       return changed;
+}
+
+void be_init_irgmod(void)
+{
+       FIRM_DBG_REGISTER(dbg, "firm.be.irgmod");
+}
+
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_irgmod);