Fix aliasing bug that also caused memory usage problems.

[pf3gnuchains/gcc-fork.git] / gcc / ra-colorize.c

diff --git a/gcc/ra-colorize.c b/gcc/ra-colorize.c
index 245292b..e3118a0 100644 (file)
--- a/gcc/ra-colorize.c
+++ b/gcc/ra-colorize.c
@@ -1,5 +1,5 @@
 /* Graph coloring register allocator
-   Copyright (C) 2001, 2002 Free Software Foundation, Inc.
+   Copyright (C) 2001, 2002, 2004 Free Software Foundation, Inc.
    Contributed by Michael Matz <matz@suse.de>
    and Daniel Berlin <dan@cgsoftware.com>.
 
@@ -50,7 +50,7 @@
 static void push_list (struct dlist *, struct dlist **);
 static void push_list_end (struct dlist *, struct dlist **);
 static void free_dlist (struct dlist **);
-static void put_web_at_end (struct web *, enum node_type);
+static void put_web_at_end (struct web *, enum ra_node_type);
 static void put_move (struct move *, enum move_type);
 static void build_worklists (struct df *);
 static void enable_move (struct web *);
@@ -61,7 +61,7 @@ static void remove_move (struct web *, struct move *);
 static void add_worklist (struct web *);
 static int ok (struct web *, struct web *);
 static int conservative (struct web *, struct web *);
-static inline unsigned int simplify_p (enum node_type);
+static inline unsigned int simplify_p (enum ra_node_type);
 static void combine (struct web *, struct web *);
 static void coalesce (void);
 static void freeze_moves (struct web *);
@@ -92,6 +92,7 @@ static void add_web_pair_cost (struct web *, struct web *,
                               unsigned HOST_WIDE_INT, unsigned int);
 static int comp_web_pairs (const void *, const void *);
 static void sort_and_combine_web_pairs (int);
+static int ok_class (struct web *, struct web *);
 static void aggressive_coalesce (void);
 static void extended_coalesce_2 (void);
 static void check_uncoalesced_moves (void);
@@ -168,7 +169,7 @@ free_dlist (struct dlist **list)
    Inline, because it's called with constant TYPE every time.  */
 
 inline void
-put_web (struct web *web, enum node_type type)
+put_web (struct web *web, enum ra_node_type type)
 {
   switch (type)
     {
@@ -260,7 +261,7 @@ reset_lists (void)
    list.  Additionally TYPE may not be SIMPLIFY.  */
 
 static void
-put_web_at_end (struct web *web, enum node_type type)
+put_web_at_end (struct web *web, enum ra_node_type type)
 {
   if (type == PRECOLORED)
     type = INITIAL;
@@ -683,7 +684,7 @@ alias (struct web *web)
    SIMPLIFY types.  */
 
 static inline unsigned int
-simplify_p (enum node_type type)
+simplify_p (enum ra_node_type type)
 {
   return type == SIMPLIFY || type == SIMPLIFY_SPILL || type == SIMPLIFY_FAT;
 }
@@ -841,7 +842,8 @@ coalesce (void)
     }
   else if (target->type == PRECOLORED
           || TEST_BIT (sup_igraph, source->id * num_webs + target->id)
-          || TEST_BIT (sup_igraph, target->id * num_webs + source->id))
+          || TEST_BIT (sup_igraph, target->id * num_webs + source->id)
+          || !ok_class (target, source))
     {
       remove_move (source, m);
       remove_move (target, m);
@@ -2464,6 +2466,39 @@ sort_and_combine_web_pairs (int for_move)
   free (sorted);
 }
 
+/* Returns nonzero if source/target reg classes are ok for coalesce.  */
+
+static int
+ok_class (struct web *target, struct web *source)
+{
+  /* Don't coalesce if preferred classes are different and at least one
+     of them has a size of 1. This was preventing things such as the
+     branch on count transformation (i.e. DoLoop) since the target, which
+     prefers the CTR, was being coalesced with a source which preferred
+     GENERAL_REGS. If only one web has a preferred class with 1 free reg
+     then set it as the preferred color of the other web.   */
+  enum reg_class t_class, s_class;
+  t_class = reg_preferred_class (target->regno);
+  s_class = reg_preferred_class (source->regno);
+  if (t_class != s_class)
+    {
+      if (num_free_regs[t_class] == 1)
+       {
+         if (num_free_regs[s_class] != 1)
+           SET_HARD_REG_BIT (source->prefer_colors,
+                             single_reg_in_regclass[t_class]);
+         return 0;
+       }
+      else if (num_free_regs[s_class] == 1)
+       {
+           SET_HARD_REG_BIT (target->prefer_colors,
+                             single_reg_in_regclass[s_class]);
+         return 0;
+       }
+    }
+  return 1;
+}
+
 /* Greedily coalesce all moves possible.  Begin with the web pair
    giving the most saving if coalesced.  */
 
@@ -2487,7 +2522,8 @@ aggressive_coalesce (void)
        if (s != t
            && t->type != PRECOLORED
            && !TEST_BIT (sup_igraph, s->id * num_webs + t->id)
-           && !TEST_BIT (sup_igraph, t->id * num_webs + s->id))
+           && !TEST_BIT (sup_igraph, t->id * num_webs + s->id)
+           && ok_class (t, s))
          {
            if ((s->type == PRECOLORED && ok (t, s))
                || s->type != PRECOLORED)
@@ -2557,6 +2593,7 @@ extended_coalesce_2 (void)
                                    dest->id * num_webs + source->id)
                      && !TEST_BIT (sup_igraph,
                                    source->id * num_webs + dest->id)
+                     && ok_class (dest, source)
                      && hard_regs_intersect_p (&source->usable_regs,
                                                &dest->usable_regs))
                    add_web_pair_cost (dest, source,
@@ -2608,7 +2645,7 @@ check_uncoalesced_moves (void)
 void
 ra_colorize_graph (struct df *df)
 {
-  if (rtl_dump_file)
+  if (dump_file)
     dump_igraph (df);
   build_worklists (df);