--- a/gcc/fwprop.c	Tue May 25 18:58:51 2010 +0900
+++ b/gcc/fwprop.c	Tue Mar 22 17:18:12 2011 +0900
@@ -1,5 +1,5 @@
 /* RTL-based forward propagation pass for GNU compiler.
-   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010
+   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011
    Free Software Foundation, Inc.
    Contributed by Paolo Bonzini and Steven Bosscher.
 
@@ -23,12 +23,12 @@
 #include "system.h"
 #include "coretypes.h"
 #include "tm.h"
-#include "toplev.h"
+#include "diagnostic-core.h"
 
+#include "sparseset.h"
 #include "timevar.h"
 #include "rtl.h"
 #include "tm_p.h"
-#include "emit-rtl.h"
 #include "insn-config.h"
 #include "recog.h"
 #include "flags.h"
@@ -40,6 +40,7 @@
 #include "cfgloop.h"
 #include "tree-pass.h"
 #include "domwalk.h"
+#include "emit-rtl.h"
 
 
 /* This pass does simple forward propagation and simplification when an
@@ -220,8 +221,8 @@
   struct df_lr_bb_info *lr_bb_info = df_lr_get_bb_info (bb_index);
   rtx insn;
 
-  bitmap_copy (local_md, md_bb_info->in);
-  bitmap_copy (local_lr, lr_bb_info->in);
+  bitmap_copy (local_md, &md_bb_info->in);
+  bitmap_copy (local_lr, &lr_bb_info->in);
 
   /* Push a marker for the leave_block callback.  */
   VEC_safe_push (df_ref, heap, reg_defs_stack, NULL);
@@ -848,95 +849,95 @@
 }
 
 
-struct find_occurrence_data
-{
-  rtx find;
-  rtx *retval;
-};
+static df_ref *active_defs;
+#ifdef ENABLE_CHECKING
+static sparseset active_defs_check;
+#endif
 
-/* Callback for for_each_rtx, used in find_occurrence.
-   See if PX is the rtx we have to find.  Return 1 to stop for_each_rtx
-   if successful, or 0 to continue traversing otherwise.  */
+/* Fill the ACTIVE_DEFS array with the use->def link for the registers
+   mentioned in USE_REC.  Register the valid entries in ACTIVE_DEFS_CHECK
+   too, for checking purposes.  */
 
-static int
-find_occurrence_callback (rtx *px, void *data)
+static void
+register_active_defs (df_ref *use_rec)
 {
-  struct find_occurrence_data *fod = (struct find_occurrence_data *) data;
-  rtx x = *px;
-  rtx find = fod->find;
+  while (*use_rec)
+    {
+      df_ref use = *use_rec++;
+      df_ref def = get_def_for_use (use);
+      int regno = DF_REF_REGNO (use);
 
-  if (x == find)
-    {
-      fod->retval = px;
-      return 1;
+#ifdef ENABLE_CHECKING
+      sparseset_set_bit (active_defs_check, regno);
+#endif
+      active_defs[regno] = def;
     }
-
-  return 0;
 }
 
-/* Return a pointer to one of the occurrences of register FIND in *PX.  */
 
-static rtx *
-find_occurrence (rtx *px, rtx find)
-{
-  struct find_occurrence_data data;
+/* Build the use->def links that we use to update the dataflow info
+   for new uses.  Note that building the links is very cheap and if
+   it were done earlier, they could be used to rule out invalid
+   propagations (in addition to what is done in all_uses_available_at).
+   I'm not doing this yet, though.  */
 
-  gcc_assert (REG_P (find)
-	      || (GET_CODE (find) == SUBREG
-		  && REG_P (SUBREG_REG (find))));
-
-  data.find = find;
-  data.retval = NULL;
-  for_each_rtx (px, find_occurrence_callback, &data);
-  return data.retval;
+static void
+update_df_init (rtx def_insn, rtx insn)
+{
+#ifdef ENABLE_CHECKING
+  sparseset_clear (active_defs_check);
+#endif
+  register_active_defs (DF_INSN_USES (def_insn));
+  register_active_defs (DF_INSN_USES (insn));
+  register_active_defs (DF_INSN_EQ_USES (insn));
 }
 
-
-/* Inside INSN, the expression rooted at *LOC has been changed, moving some
-   uses from USE_VEC.  Find those that are present, and create new items
-   in the data flow object of the pass.  Mark any new uses as having the
-   given TYPE.  */
-static void
-update_df (rtx insn, rtx *loc, df_ref *use_rec, enum df_ref_type type,
-	   int new_flags)
+
+/* Update the USE_DEF_REF array for the given use, using the active definitions
+   in the ACTIVE_DEFS array to match pseudos to their def. */
+
+static inline void
+update_uses (df_ref *use_rec)
 {
-  bool changed = false;
-
-  /* Add a use for the registers that were propagated.  */
   while (*use_rec)
     {
-      df_ref use = *use_rec;
-      df_ref orig_use = use, new_use;
-      int width = -1;
-      int offset = -1;
-      enum machine_mode mode = VOIDmode;
-      rtx *new_loc = find_occurrence (loc, DF_REF_REG (orig_use));
-      use_rec++;
-
-      if (!new_loc)
-	continue;
-
-      if (DF_REF_FLAGS_IS_SET (orig_use, DF_REF_SIGN_EXTRACT | DF_REF_ZERO_EXTRACT))
-	{
-	  width = DF_REF_EXTRACT_WIDTH (orig_use);
-	  offset = DF_REF_EXTRACT_OFFSET (orig_use);
-	  mode = DF_REF_EXTRACT_MODE (orig_use);
-	}
-
-      /* Add a new insn use.  Use the original type, because it says if the
-         use was within a MEM.  */
-      new_use = df_ref_create (DF_REF_REG (orig_use), new_loc,
-			       insn, BLOCK_FOR_INSN (insn),
-			       type, DF_REF_FLAGS (orig_use) | new_flags,
-			       width, offset, mode);
+      df_ref use = *use_rec++;
+      int regno = DF_REF_REGNO (use);
 
       /* Set up the use-def chain.  */
-      gcc_assert (DF_REF_ID (new_use) == (int) VEC_length (df_ref, use_def_ref));
-      VEC_safe_push (df_ref, heap, use_def_ref, get_def_for_use (orig_use));
-      changed = true;
+      if (DF_REF_ID (use) >= (int) VEC_length (df_ref, use_def_ref))
+        VEC_safe_grow_cleared (df_ref, heap, use_def_ref,
+                               DF_REF_ID (use) + 1);
+
+#ifdef ENABLE_CHECKING
+      gcc_assert (sparseset_bit_p (active_defs_check, regno));
+#endif
+      VEC_replace (df_ref, use_def_ref, DF_REF_ID (use), active_defs[regno]);
     }
-  if (changed)
-    df_insn_rescan (insn);
+}
+
+
+/* Update the USE_DEF_REF array for the uses in INSN.  Only update note
+   uses if NOTES_ONLY is true.  */
+
+static void
+update_df (rtx insn, rtx note)
+{
+  struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
+
+  if (note)
+    {
+      df_uses_create (&XEXP (note, 0), insn, DF_REF_IN_NOTE);
+      df_notes_rescan (insn);
+    }
+  else
+    {
+      df_uses_create (&PATTERN (insn), insn, 0);
+      df_insn_rescan (insn);
+      update_uses (DF_INSN_INFO_USES (insn_info));
+    }
+
+  update_uses (DF_INSN_INFO_EQ_USES (insn_info));
 }
 
 
@@ -950,13 +951,14 @@
 try_fwprop_subst (df_ref use, rtx *loc, rtx new_rtx, rtx def_insn, bool set_reg_equal)
 {
   rtx insn = DF_REF_INSN (use);
-  enum df_ref_type type = DF_REF_TYPE (use);
-  int flags = DF_REF_FLAGS (use);
   rtx set = single_set (insn);
+  rtx note = NULL_RTX;
   bool speed = optimize_bb_for_speed_p (BLOCK_FOR_INSN (insn));
   int old_cost = 0;
   bool ok;
 
+  update_df_init (def_insn, insn);
+
   /* forward_propagate_subreg may be operating on an instruction with
      multiple sets.  If so, assume the cost of the new instruction is
      not greater than the old one.  */
@@ -1001,14 +1003,6 @@
     {
       confirm_change_group ();
       num_changes++;
-
-      df_ref_remove (use);
-      if (!CONSTANT_P (new_rtx))
-	{
-	  struct df_insn_info *insn_info = DF_INSN_INFO_GET (def_insn);
-	  update_df (insn, loc, DF_INSN_INFO_USES (insn_info), type, flags);
-	  update_df (insn, loc, DF_INSN_INFO_EQ_USES (insn_info), type, flags);
-	}
     }
   else
     {
@@ -1021,21 +1015,13 @@
 	  if (dump_file)
 	    fprintf (dump_file, " Setting REG_EQUAL note\n");
 
-	  set_unique_reg_note (insn, REG_EQUAL, copy_rtx (new_rtx));
-
-	  /* ??? Is this still necessary if we add the note through
-	     set_unique_reg_note?  */
-          if (!CONSTANT_P (new_rtx))
-	    {
-	      struct df_insn_info *insn_info = DF_INSN_INFO_GET (def_insn);
-	      update_df (insn, loc, DF_INSN_INFO_USES (insn_info),
-			 type, DF_REF_IN_NOTE);
-	      update_df (insn, loc, DF_INSN_INFO_EQ_USES (insn_info),
-			 type, DF_REF_IN_NOTE);
-	    }
+	  note = set_unique_reg_note (insn, REG_EQUAL, copy_rtx (new_rtx));
 	}
     }
 
+  if ((ok || note) && !CONSTANT_P (new_rtx))
+    update_df (insn, note);
+
   return ok;
 }
 
@@ -1163,6 +1149,7 @@
   if (use_vec[0] && use_vec[1])
     return false;
 
+  update_df_init (def_insn, use_insn);
   speed_p = optimize_bb_for_speed_p (BLOCK_FOR_INSN (use_insn));
   asm_operands = NULL_RTX;
   switch (GET_CODE (use_pat))
@@ -1213,6 +1200,7 @@
   if (num_changes_pending () == 0 || !apply_change_group ())
     return false;
 
+  update_df (use_insn, NULL);
   num_changes++;
   return true;
 }
@@ -1304,10 +1292,11 @@
 	loc = &SET_SRC (use_set);
 
       /* Do not replace an existing REG_EQUAL note if the insn is not
-	 recognized.  Either we're already replacing in the note, or
-	 we'll separately try plugging the definition in the note and
-	 simplifying.  */
-      set_reg_equal = (note == NULL_RTX);
+	 recognized.  Either we're already replacing in the note, or we'll
+	 separately try plugging the definition in the note and simplifying.
+	 And only install a REQ_EQUAL note when the destination is a REG,
+	 as the note would be invalid otherwise.  */
+      set_reg_equal = (note == NULL_RTX && REG_P (SET_DEST (use_set)));
     }
 
   if (GET_MODE (*loc) == VOIDmode)
@@ -1326,9 +1315,10 @@
 
 
 /* Given a use USE of an insn, if it has a single reaching
-   definition, try to forward propagate it into that insn.  */
+   definition, try to forward propagate it into that insn.
+   Return true if cfg cleanup will be needed.  */
 
-static void
+static bool
 forward_propagate_into (df_ref use)
 {
   df_ref def;
@@ -1336,22 +1326,22 @@
   rtx parent;
 
   if (DF_REF_FLAGS (use) & DF_REF_READ_WRITE)
-    return;
+    return false;
   if (DF_REF_IS_ARTIFICIAL (use))
-    return;
+    return false;
 
   /* Only consider uses that have a single definition.  */
   def = get_def_for_use (use);
   if (!def)
-    return;
+    return false;
   if (DF_REF_FLAGS (def) & DF_REF_READ_WRITE)
-    return;
+    return false;
   if (DF_REF_IS_ARTIFICIAL (def))
-    return;
+    return false;
 
   /* Do not propagate loop invariant definitions inside the loop.  */
   if (DF_REF_BB (def)->loop_father != DF_REF_BB (use)->loop_father)
-    return;
+    return false;
 
   /* Check if the use is still present in the insn!  */
   use_insn = DF_REF_INSN (use);
@@ -1361,19 +1351,26 @@
     parent = PATTERN (use_insn);
 
   if (!reg_mentioned_p (DF_REF_REG (use), parent))
-    return;
+    return false;
 
   def_insn = DF_REF_INSN (def);
   if (multiple_sets (def_insn))
-    return;
+    return false;
   def_set = single_set (def_insn);
   if (!def_set)
-    return;
+    return false;
 
   /* Only try one kind of propagation.  If two are possible, we'll
      do it on the following iterations.  */
-  if (!forward_propagate_and_simplify (use, def_insn, def_set))
-    forward_propagate_subreg (use, def_insn, def_set);
+  if (forward_propagate_and_simplify (use, def_insn, def_set)
+      || forward_propagate_subreg (use, def_insn, def_set))
+    {
+      if (cfun->can_throw_non_call_exceptions
+	  && find_reg_note (use_insn, REG_EH_REGION, NULL_RTX)
+	  && purge_dead_edges (DF_REF_BB (use)))
+	return true;
+    }
+  return false;
 }
 
 
@@ -1391,6 +1388,11 @@
 
   build_single_def_use_links ();
   df_set_flags (DF_DEFER_INSN_RESCAN);
+
+  active_defs = XNEWVEC (df_ref, max_reg_num ());
+#ifdef ENABLE_CHECKING
+  active_defs_check = sparseset_alloc (max_reg_num ());
+#endif
 }
 
 static void
@@ -1399,6 +1401,11 @@
   loop_optimizer_finalize ();
 
   VEC_free (df_ref, heap, use_def_ref);
+  free (active_defs);
+#ifdef ENABLE_CHECKING
+  sparseset_free (active_defs_check);
+#endif
+
   free_dominance_info (CDI_DOMINATORS);
   cleanup_cfg (0);
   delete_trivially_dead_insns (get_insns (), max_reg_num ());
@@ -1422,10 +1429,11 @@
 fwprop (void)
 {
   unsigned i;
+  bool need_cleanup = false;
 
   fwprop_init ();
 
-  /* Go through all the uses.  update_df will create new ones at the
+  /* Go through all the uses.  df_uses_create will create new ones at the
      end, and we'll go through them as well.
 
      Do not forward propagate addresses into loops until after unrolling.
@@ -1439,10 +1447,12 @@
 	    || DF_REF_BB (use)->loop_father == NULL
 	    /* The outer most loop is not really a loop.  */
 	    || loop_outer (DF_REF_BB (use)->loop_father) == NULL)
-	  forward_propagate_into (use);
+	  need_cleanup |= forward_propagate_into (use);
     }
 
   fwprop_done ();
+  if (need_cleanup)
+    cleanup_cfg (0);
   return 0;
 }
 
@@ -1461,8 +1471,10 @@
   0,                                    /* properties_provided */
   0,                                    /* properties_destroyed */
   0,                                    /* todo_flags_start */
-  TODO_df_finish | TODO_verify_rtl_sharing |
-  TODO_dump_func                        /* todo_flags_finish */
+  TODO_df_finish
+    | TODO_verify_flow
+    | TODO_verify_rtl_sharing
+    | TODO_dump_func                    /* todo_flags_finish */
  }
 };
 
@@ -1470,9 +1482,11 @@
 fwprop_addr (void)
 {
   unsigned i;
+  bool need_cleanup = false;
+
   fwprop_init ();
 
-  /* Go through all the uses.  update_df will create new ones at the
+  /* Go through all the uses.  df_uses_create will create new ones at the
      end, and we'll go through them as well.  */
   for (i = 0; i < DF_USES_TABLE_SIZE (); i++)
     {
@@ -1482,11 +1496,13 @@
 	    && DF_REF_BB (use)->loop_father != NULL
 	    /* The outer most loop is not really a loop.  */
 	    && loop_outer (DF_REF_BB (use)->loop_father) != NULL)
-	  forward_propagate_into (use);
+	  need_cleanup |= forward_propagate_into (use);
     }
 
   fwprop_done ();
 
+  if (need_cleanup)
+    cleanup_cfg (0);
   return 0;
 }