2006-08-18 Christophe Jaillet <christophe.jaillet@wanadoo.fr>

[pf3gnuchains/gcc-fork.git] / gcc / cfgloopanal.c

diff --git a/gcc/cfgloopanal.c b/gcc/cfgloopanal.c
index 0a5179e..da54583 100644 (file)
--- a/gcc/cfgloopanal.c
+++ b/gcc/cfgloopanal.c
@@ -1,5 +1,5 @@
 /* Natural loop analysis code for GNU compiler.
-   Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
+   Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -15,8 +15,8 @@ for more details.
 
 You should have received a copy of the GNU General Public License
 along with GCC; see the file COPYING.  If not, write to the Free
-Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-02111-1307, USA.  */
+Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301, USA.  */
 
 #include "config.h"
 #include "system.h"
@@ -24,6 +24,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 #include "tm.h"
 #include "rtl.h"
 #include "hard-reg-set.h"
+#include "obstack.h"
 #include "basic-block.h"
 #include "cfgloop.h"
 #include "expr.h"
@@ -32,7 +33,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 /* Checks whether BB is executed exactly once in each LOOP iteration.  */
 
 bool
-just_once_each_iteration_p (struct loop *loop, basic_block bb)
+just_once_each_iteration_p (const struct loop *loop, basic_block bb)
 {
   /* It must be executed at least once each iteration.  */
   if (!dominated_by_p (CDI_DOMINATORS, loop->latch, bb))
@@ -82,7 +83,9 @@ struct graph
 /* Dumps graph G into F.  */
 
 extern void dump_graph (FILE *, struct graph *);
-void dump_graph (FILE *f, struct graph *g)
+
+void
+dump_graph (FILE *f, struct graph *g)
 {
   int i;
   struct edge *e;
@@ -110,10 +113,10 @@ void dump_graph (FILE *f, struct graph *g)
 static struct graph *
 new_graph (int n_vertices)
 {
-  struct graph *g = xmalloc (sizeof (struct graph));
+  struct graph *g = XNEW (struct graph);
 
   g->n_vertices = n_vertices;
-  g->vertices = xcalloc (n_vertices, sizeof (struct vertex));
+  g->vertices = XCNEWVEC (struct vertex, n_vertices);
 
   return g;
 }
@@ -177,7 +180,7 @@ dfs (struct graph *g, int *qs, int nq, int *qt, bool forward)
            {
              if (qt)
                qt[tick] = v;
-             g->vertices[v].post = tick++;
+             g->vertices[v].post = tick++;
 
              if (!top)
                break;
@@ -208,8 +211,7 @@ check_irred (struct graph *g, struct edge *e)
 
   /* All edges should lead from a component with higher number to the
      one with lower one.  */
-  if (g->vertices[e->src].component < g->vertices[e->dest].component)
-    abort ();
+  gcc_assert (g->vertices[e->src].component >= g->vertices[e->dest].component);
 
   if (g->vertices[e->src].component != g->vertices[e->dest].component)
     return;
@@ -257,7 +259,7 @@ free_graph (struct graph *g)
    for parts of cycles that only "pass" through some loop -- i.e. for
    each cycle, we want to mark blocks that belong directly to innermost
    loop containing the whole cycle.
-   
+
    LOOPS is the loop tree.  */
 
 #define LOOP_REPR(LOOP) ((LOOP)->num + last_basic_block)
@@ -268,10 +270,11 @@ mark_irreducible_loops (struct loops *loops)
 {
   basic_block act;
   edge e;
+  edge_iterator ei;
   int i, src, dest;
   struct graph *g;
-  int *queue1 = xmalloc ((last_basic_block + loops->num) * sizeof (int));
-  int *queue2 = xmalloc ((last_basic_block + loops->num) * sizeof (int));
+  int *queue1 = XNEWVEC (int, last_basic_block + loops->num);
+  int *queue2 = XNEWVEC (int, last_basic_block + loops->num);
   int nq, depth;
   struct loop *cloop;
 
@@ -279,7 +282,7 @@ mark_irreducible_loops (struct loops *loops)
   FOR_BB_BETWEEN (act, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb)
     {
       act->flags &= ~BB_IRREDUCIBLE_LOOP;
-      for (e = act->succ; e; e = e->succ_next)
+      FOR_EACH_EDGE (e, ei, act->succs)
        e->flags &= ~EDGE_IRREDUCIBLE_LOOP;
     }
 
@@ -287,10 +290,10 @@ mark_irreducible_loops (struct loops *loops)
   g = new_graph (last_basic_block + loops->num);
 
   FOR_BB_BETWEEN (act, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb)
-    for (e = act->succ; e; e = e->succ_next)
+    FOR_EACH_EDGE (e, ei, act->succs)
       {
-        /* Ignore edges to exit.  */
-        if (e->dest == EXIT_BLOCK_PTR)
+       /* Ignore edges to exit.  */
+       if (e->dest == EXIT_BLOCK_PTR)
          continue;
 
        /* And latch edges.  */
@@ -416,24 +419,25 @@ unsigned
 expected_loop_iterations (const struct loop *loop)
 {
   edge e;
+  edge_iterator ei;
 
-  if (loop->header->count)
+  if (loop->latch->count || loop->header->count)
     {
       gcov_type count_in, count_latch, expected;
 
       count_in = 0;
       count_latch = 0;
 
-      for (e = loop->header->pred; e; e = e->pred_next)
+      FOR_EACH_EDGE (e, ei, loop->header->preds)
        if (e->src == loop->latch)
          count_latch = e->count;
        else
          count_in += e->count;
 
       if (count_in == 0)
-        expected = count_latch * 2;
+       expected = count_latch * 2;
       else
-        expected = (count_latch + count_in - 1) / count_in;
+       expected = (count_latch + count_in - 1) / count_in;
 
       /* Avoid overflows.  */
       return (expected > REG_BR_PROB_BASE ? REG_BR_PROB_BASE : expected);
@@ -445,7 +449,7 @@ expected_loop_iterations (const struct loop *loop)
       freq_in = 0;
       freq_latch = 0;
 
-      for (e = loop->header->pred; e; e = e->pred_next)
+      FOR_EACH_EDGE (e, ei, loop->header->preds)
        if (e->src == loop->latch)
          freq_latch = EDGE_FREQUENCY (e);
        else
@@ -524,7 +528,7 @@ init_set_costs (void)
   target_res_regs = 3;
 
   /* These are really just heuristic values.  */
-  
+
   start_sequence ();
   emit_move_insn (reg1, reg2);
   seq = get_insns ();
@@ -563,3 +567,29 @@ global_cost_for_size (unsigned size, unsigned regs_used, unsigned n_uses)
   return cost;
 }
 
+/* Sets EDGE_LOOP_EXIT flag for all exits of LOOPS.  */
+
+void
+mark_loop_exit_edges (struct loops *loops)
+{
+  basic_block bb;
+  edge e;
+
+  if (loops->num <= 1)
+    return;
+
+  FOR_EACH_BB (bb)
+    {
+      edge_iterator ei;
+
+      FOR_EACH_EDGE (e, ei, bb->succs)
+       {
+         if (bb->loop_father->outer
+             && loop_exit_edge_p (bb->loop_father, e))
+           e->flags |= EDGE_LOOP_EXIT;
+         else
+           e->flags &= ~EDGE_LOOP_EXIT;
+       }
+    }
+}
+