--- a/gcc/dce.c	Sun Feb 07 18:28:00 2010 +0900
+++ b/gcc/dce.c	Fri Feb 12 23:39:51 2010 +0900
@@ -27,6 +27,7 @@
 #include "regs.h"
 #include "hard-reg-set.h"
 #include "flags.h"
+#include "except.h"
 #include "df.h"
 #include "cselib.h"
 #include "dce.h"
@@ -35,9 +36,6 @@
 #include "dbgcnt.h"
 #include "tm_p.h"
 
-DEF_VEC_I(int);
-DEF_VEC_ALLOC_I(int,heap);
-
 
 /* -------------------------------------------------------------------------
    Core mark/delete routines
@@ -81,13 +79,7 @@
       return false;
 
     default:
-      if (volatile_refs_p (body))
-	return false;
-
-      if (flag_non_call_exceptions && may_trap_p (body))
-	return false;
-
-      return true;
+      return !volatile_refs_p (body);
     }
 }
 
@@ -101,6 +93,14 @@
   rtx body, x;
   int i;
 
+  /* Don't delete jumps, notes and the like.  */
+  if (!NONJUMP_INSN_P (insn))
+    return false;
+
+  /* Don't delete insns that can throw.  */
+  if (!insn_nothrow_p (insn))
+    return false;
+
   if (CALL_P (insn)
       /* We cannot delete calls inside of the recursive dce because
 	 this may cause basic blocks to be deleted and this messes up
@@ -115,13 +115,11 @@
 	  && !RTL_LOOPING_CONST_OR_PURE_CALL_P (insn)))
     return find_call_stack_args (insn, false, fast, arg_stores);
 
-  if (!NONJUMP_INSN_P (insn))
-    return false;
-
   body = PATTERN (insn);
   switch (GET_CODE (body))
     {
     case USE:
+    case VAR_LOCATION:
       return false;
 
     case CLOBBER:
@@ -352,8 +350,8 @@
 	  }
 	for (byte = off; byte < off + INTVAL (MEM_SIZE (mem)); byte++)
 	  {
-	    gcc_assert (!bitmap_bit_p (sp_bytes, byte - min_sp_off));
-	    bitmap_set_bit (sp_bytes, byte - min_sp_off);
+	    if (!bitmap_set_bit (sp_bytes, byte - min_sp_off))
+	      gcc_unreachable ();
 	  }
       }
 
@@ -440,9 +438,8 @@
 	{
 	  if (byte < min_sp_off
 	      || byte >= max_sp_off
-	      || !bitmap_bit_p (sp_bytes, byte - min_sp_off))
+	      || !bitmap_clear_bit (sp_bytes, byte - min_sp_off))
 	    break;
-	  bitmap_clear_bit (sp_bytes, byte - min_sp_off);
 	}
 
       if (!deletable_insn_p (insn, fast, NULL))
@@ -625,7 +622,7 @@
 
   FOR_ALL_BB (bb)
     {
-      for (use_rec = df_get_artificial_uses (bb->index); 
+      for (use_rec = df_get_artificial_uses (bb->index);
 	   *use_rec; use_rec++)
 	for (defs = DF_REF_CHAIN (*use_rec); defs; defs = defs->next)
 	  if (! DF_REF_IS_ARTIFICIAL (defs->ref))
@@ -642,6 +639,9 @@
   struct df_link *defs;
   df_ref *use_rec;
 
+  if (DEBUG_INSN_P (insn))
+    return;
+
   for (use_rec = DF_INSN_USES (insn); *use_rec; use_rec++)
     {
       df_ref use = *use_rec;
@@ -738,9 +738,9 @@
 {
  {
   RTL_PASS,
-  "dce",                                /* name */
-  gate_ud_dce,                        /* gate */
-  rest_of_handle_ud_dce,              /* execute */
+  "ud dce",                             /* name */
+  gate_ud_dce,                          /* gate */
+  rest_of_handle_ud_dce,                /* execute */
   NULL,                                 /* sub */
   NULL,                                 /* next */
   0,                                    /* static_pass_number */
@@ -825,7 +825,7 @@
 		mark_insn (insn, true);
 		goto quickexit;
 	      }
-	    
+
 	    last = start + len;
 	    while (start < last)
 	      if (bitmap_bit_p (local_live, start++))
@@ -834,9 +834,9 @@
 		  goto quickexit;
 		}
 	  }
-	
-      quickexit: 
-	
+
+      quickexit:
+
 	/* No matter if the instruction is needed or not, we remove
 	   any regno in the defs from the live set.  */
 	df_byte_lr_simulate_defs (insn, local_live);
@@ -848,12 +848,12 @@
 
 	if (dump_file)
 	  {
-	    fprintf (dump_file, "finished processing insn %d live out = ", 
+	    fprintf (dump_file, "finished processing insn %d live out = ",
 		     INSN_UID (insn));
 	    df_print_byte_regset (dump_file, local_live);
 	  }
       }
-  
+
   df_byte_lr_simulate_artificial_refs_at_top (bb, local_live);
 
   block_changed = !bitmap_equal_p (local_live, DF_BYTE_LR_IN (bb));
@@ -913,10 +913,10 @@
 	      needed = true;
 	      break;
 	    }
-	    
+
 	if (needed)
 	  mark_insn (insn, true);
-	
+
 	/* No matter if the instruction is needed or not, we remove
 	   any regno in the defs from the live set.  */
 	df_simulate_defs (insn, local_live);
@@ -926,7 +926,7 @@
 	if (marked_insn_p (insn))
 	  df_simulate_uses (insn, local_live);
       }
-  
+
   df_simulate_finalize_backwards (bb, local_live);
 
   block_changed = !bitmap_equal_p (local_live, DF_LR_IN (bb));
@@ -986,15 +986,15 @@
 	    }
 
 	  if (byte_level)
-	    local_changed 
+	    local_changed
 	      = byte_dce_process_block (bb, bitmap_bit_p (redo_out, index),
 					  bb_has_eh_pred (bb) ? au_eh : au);
 	  else
-	    local_changed 
+	    local_changed
 	      = dce_process_block (bb, bitmap_bit_p (redo_out, index),
 				   bb_has_eh_pred (bb) ? au_eh : au);
 	  bitmap_set_bit (processed, index);
-	  
+
 	  if (local_changed)
 	    {
 	      edge e;
@@ -1010,7 +1010,7 @@
 		  bitmap_set_bit (redo_out, e->src->index);
 	    }
 	}
-      
+
       if (global_changed)
 	{
 	  /* Turn off the RUN_DCE flag to prevent recursive calls to
@@ -1023,11 +1023,11 @@
 	  sbitmap_zero (marked);
 	  bitmap_clear (processed);
 	  bitmap_clear (redo_out);
-	  
+
 	  /* We do not need to rescan any instructions.  We only need
 	     to redo the dataflow equations for the blocks that had a
 	     change at the top of the block.  Then we need to redo the
-	     iteration.  */ 
+	     iteration.  */
 	  if (byte_level)
 	    df_analyze_problem (df_byte_lr, all_blocks, postorder, n_blocks);
 	  else
@@ -1090,9 +1090,9 @@
       /* If dce is able to delete something, it has to happen
 	 immediately.  Otherwise there will be problems handling the
 	 eq_notes.  */
-      enum df_changeable_flags old_flags 
-	= df_clear_flags (DF_DEFER_INSN_RESCAN + DF_NO_INSN_RESCAN);
-      
+      int old_flags =
+	df_clear_flags (DF_DEFER_INSN_RESCAN + DF_NO_INSN_RESCAN);
+
       df_in_progress = true;
       rest_of_handle_fast_dce ();
       df_in_progress = false;
@@ -1123,7 +1123,7 @@
 {
  {
   RTL_PASS,
-  "dce",                                /* name */
+  "rtl dce",                            /* name */
   gate_fast_dce,                        /* gate */
   rest_of_handle_fast_dce,              /* execute */
   NULL,                                 /* sub */