patch committed to dataflow branch

[Kenneth Zadeck <zadeck at naturalbridge dot com>]

This patch fixes several storage leaks with df and changes the way that libcalls are processed in dce.c.

This code has been bootstrapped and regression tested on

x86_64-unknown-linux-gnu
powerpc64-unknown-linux-gnu
i686-pc-linux-gnu

Kenny


2006-04-25  Kenneth Zadeck <zadeck@naturalbridge.com>
    * flow.c (rest_of_handle_life): Removed unnecessary code.
    * df-scan.c (df_scan_free_internal, df_scan_free): Fixed
    storage leak.
    * df-core.c (df_delete_basic_block): Removed dangling pointer.
    * mode-switching.c (optimize_move_switching): Moved creation of df
    instance to avoid storage leak.
    * ifcvt.c (if_convert): Fixed storage leak.  
    * dce.c (mark_insn,
    rest_of_handle_dce): Removed old way of processing libcalls.
    (libcall_matches_p, mark_libcall_insns): Removed.
    (mark_libcall): New function.
    (mark_reg_dependencies, dce_process_block): New code to check for
    libcalls.
    (fast_dce): Fixed storage leak.
   

Index: flow.c
===================================================================
--- flow.c	(revision 113230)
+++ flow.c	(working copy)
@@ -3892,11 +3892,7 @@ rest_of_handle_life (void)
   df_ur_add_problem (rtl_df, 0);
 
   life_analysis (PROP_FINAL);
-#if 0
-  if (optimize)
-    cleanup_cfg (CLEANUP_EXPENSIVE | CLEANUP_UPDATE_LIFE | CLEANUP_LOG_LINKS
-                 | (flag_thread_jumps ? CLEANUP_THREADING : 0));
-#endif
+  df_finish (rtl_df);
 
   no_new_pseudos = 1;
   return 0;
Index: df-scan.c
===================================================================
--- df-scan.c	(revision 113230)
+++ df-scan.c	(working copy)
@@ -159,6 +159,7 @@ df_scan_free_internal (struct dataflow *
   free_alloc_pool (problem_data->reg_pool);
   free_alloc_pool (problem_data->mw_reg_pool);
   free_alloc_pool (problem_data->mw_link_pool);
+  free (dflow->problem_data);
 }
 
 
@@ -279,10 +280,7 @@ df_scan_free (struct dataflow *dflow)
   struct df *df = dflow->df;
   
   if (dflow->problem_data)
-    {
-      df_scan_free_internal (dflow);
-      free (dflow->problem_data);
-    }
+    df_scan_free_internal (dflow);
 
   if (df->blocks_to_scan)
     BITMAP_FREE (df->blocks_to_scan);
Index: df-core.c
===================================================================
--- df-core.c	(revision 113230)
+++ df-core.c	(working copy)
@@ -478,8 +478,11 @@ df_delete_basic_block (struct df *df, in
     {
       struct dataflow *dflow = df->problems_in_order[i];
       if (dflow->problem->free_bb_fun)
-	dflow->problem->free_bb_fun 
-	  (dflow, bb, df_get_bb_info (dflow, bb_index)); 
+	{
+	  dflow->problem->free_bb_fun 
+	    (dflow, bb, df_get_bb_info (dflow, bb_index)); 
+	  df_set_bb_info (dflow, bb_index, NULL);
+	}
     }
 }
 
@@ -493,7 +496,10 @@ df_finish1 (struct df *df)
   int i;
 
   for (i = 0; i < df->num_problems_defined; i++)
-    df->problems_in_order[i]->problem->free_fun (df->problems_in_order[i]); 
+    {
+      struct dataflow *dflow = df->problems_in_order[i];
+      dflow->problem->free_fun (df->problems_in_order[i]); 
+    }
 
   free (df);
 }
Index: mode-switching.c
===================================================================
--- mode-switching.c	(revision 113230)
+++ mode-switching.c	(working copy)
@@ -398,12 +398,7 @@ optimize_mode_switching (void)
   int max_num_modes = 0;
   bool emited = false;
   basic_block post_entry ATTRIBUTE_UNUSED, pre_exit ATTRIBUTE_UNUSED;
-  struct df *df = df_init (DF_HARD_REGS);
-
-  df_lr_add_problem (df, 0);
-  df_ur_add_problem (df, 0);
-  df_ri_add_problem (df, 0);
-  df_analyze (df);
+  struct df *df;
 
   for (e = N_ENTITIES - 1, n_entities = 0; e >= 0; e--)
     if (OPTIMIZE_MODE_SWITCHING (e))
@@ -426,6 +421,12 @@ optimize_mode_switching (void)
   if (! n_entities)
     return 0;
 
+  df = df_init (DF_HARD_REGS);
+  df_lr_add_problem (df, 0);
+  df_ur_add_problem (df, 0);
+  df_ri_add_problem (df, 0);
+  df_analyze (df);
+
 #if defined (MODE_ENTRY) && defined (MODE_EXIT)
   /* Split the edge from the entry block, so that we can note that
      there NORMAL_MODE is supplied.  */
Index: ifcvt.c
===================================================================
--- ifcvt.c	(revision 113230)
+++ ifcvt.c	(working copy)
@@ -3950,6 +3950,7 @@ if_convert (void)
 #ifdef ENABLE_CHECKING
   verify_flow_info ();
 #endif
+  df_finish (df);
 }
 
 static bool
Index: dce.c
===================================================================
--- dce.c	(revision 113230)
+++ dce.c	(working copy)
@@ -114,22 +114,11 @@ mark_insn (rtx insn, bool fast)
 {
   if (!marked_insn_p (insn))
     {
-      unsigned int id = INSN_UID (insn);
-      rtx note;
-
       if (!fast)
 	VEC_safe_push (rtx, heap, worklist, insn);
       bitmap_set_bit (marked, INSN_UID (insn));
       if (dump_file)
-	fprintf (dump_file, "  Adding insn %d to worklist\n", id);
-
-      if ((note = find_reg_note (insn, REG_LIBCALL_ID, NULL_RTX)))
-	{
-	  if (dump_file)
-	    fprintf (dump_file, "Marking libcall " HOST_WIDE_INT_PRINT_DEC "\n",
- 		     INTVAL (XEXP (note, 0)));
-	  bitmap_set_bit (marked_libcalls, INTVAL (XEXP (note, 0)));
-	}
+	fprintf (dump_file, "  Adding insn %d to worklist\n", INSN_UID (insn));
     }
 }
 
@@ -255,29 +244,54 @@ delete_unmarked_insns (bool df_delete)
 	}
 }
 
-/* Mark each instruction belonging to a libcall whose id is in
-   marked_libcalls.  */
+/* Return true if INSN has libcall id ID.  */
+static bool
+libcall_matches_p (rtx insn, int id)
+{
+  rtx note;
+  if ((note = find_reg_note (insn, REG_LIBCALL_ID, NULL_RTX)))
+    return id == INTVAL (XEXP (note, 0));
+  else 
+    return false;
+}
 
-static void
-mark_libcall_insns (void)
+
+/* Mark all insns using DELETE_PARM in the libcall that contains
+   START_INSN.  */
+static void 
+mark_libcall (rtx start_insn, bool delete_parm)
 {
-  basic_block bb;
+  rtx note = find_reg_note (start_insn, REG_LIBCALL_ID, NULL_RTX);
+  int id = INTVAL (XEXP (note, 0));
   rtx insn;
 
-  if (bitmap_empty_p (marked_libcalls))
-    return;
-  FOR_EACH_BB (bb)
-    FOR_BB_INSNS (bb, insn)
-      {
-	rtx note;
-	if ((note = find_reg_note (insn, REG_LIBCALL_ID, NULL_RTX)))
-	  {
-	    if (bitmap_bit_p (marked_libcalls, INTVAL (XEXP (note, 0))))
-	      mark_insn (insn, false);
-	  }
-      }
+  mark_insn (start_insn, delete_parm);
+  insn = NEXT_INSN (start_insn);
+
+  for (insn = NEXT_INSN (start_insn); insn; insn = NEXT_INSN (insn))
+    {
+      if (INSN_P (insn))
+	{
+	  if (libcall_matches_p (insn, id))
+	    mark_insn (insn, delete_parm);
+	  else 
+	    break;
+	}
+    }
+  
+  for (insn = PREV_INSN (start_insn); insn; insn = PREV_INSN (insn))
+    {
+      if (INSN_P (insn))
+	{
+	  if (libcall_matches_p (insn, id))
+	    mark_insn (insn, delete_parm);
+	  else 
+	    break;
+	}
+    }
 }
 
+
 /* Free the data allocated by init_dce.  */
 
 static void
@@ -329,6 +343,10 @@ mark_reg_dependencies (rtx insn)
   struct df_link *defs;
   struct df_ref *use;
 
+  /* If this is part of a libcall, mark the entire libcall.  */
+  if (find_reg_note (insn, REG_LIBCALL_ID, NULL_RTX))
+    mark_libcall (insn, false);
+
   for (use = DF_INSN_USES (dce_df, insn); use; use = use->next_ref)
     {
       if (dump_file)
@@ -359,13 +377,6 @@ rest_of_handle_dce (void)
   while (VEC_length (rtx, worklist) > 0)
     mark_reg_dependencies (VEC_pop (rtx, worklist));
 
-  mark_libcall_insns ();
-
-  while (VEC_length (rtx, worklist) > 0)
-    mark_reg_dependencies (VEC_pop (rtx, worklist));
-
-  delete_unmarked_insns (false);
-
   end_dce ();
   return 0;
 }
@@ -427,18 +438,22 @@ end_fast_dce (void)
    changed.  */
 
 static bool
-dce_process_block (struct dataflow * dflow, basic_block bb, bool redo_out)
+dce_process_block (basic_block bb, bool redo_out)
 {
   bitmap local_live = BITMAP_ALLOC (NULL);
   rtx insn;
   bool block_changed;
   struct df_ref *def, *use;
   unsigned int bb_index = bb->index;
+  struct dataflow * dflow = dce_df->problems_by_index[DF_LR];
+  rtx libcall_start = NULL;
+  int libcall_id = -1;
 
   if (redo_out)
     {
-      /* Need to redo the live_out set if when one of the succs was
-	 done its live in change.  */
+      /* Need to redo the live_out set of this block if when one of
+	 the succs of this block has had a change in it live in
+	 set.  */
       edge e;
       edge_iterator ei;
       df_confluence_function_n con_fun_n = dflow->problem->con_fun_n;
@@ -463,9 +478,34 @@ dce_process_block (struct dataflow * dfl
   FOR_BB_INSNS_REVERSE (bb, insn)
     if (INSN_P (insn))
       {
+	/* If this is a recursive call, the libcall will have already
+	   been marked.  */
 	if (!marked_insn_p (insn))
-	  {
+	  {	
 	    bool needed = false;
+	    rtx note;
+	    if ((note = find_reg_note (insn, REG_LIBCALL_ID, NULL_RTX)))
+	      {
+		int new_id = INTVAL (XEXP (note, 0));
+		if (libcall_start)
+		  {
+		    if (libcall_id != new_id)
+		      {
+			libcall_start = insn;
+			libcall_id = new_id;
+		      }
+		  }
+		else
+		  {
+		    libcall_start = insn;
+		    libcall_id = new_id;
+		  }
+	      }
+	    else 
+	      {
+		libcall_start = NULL;
+		libcall_id = -1;
+	      }
 	    for (def = DF_INSN_GET (dce_df, insn)->defs; 
 		 def; def = def->next_ref)
 	      if (bitmap_bit_p (local_live, DF_REF_REGNO (def)))
@@ -475,7 +515,21 @@ dce_process_block (struct dataflow * dfl
 		}
 	    
 	    if (needed)
-	      mark_insn (insn, true);
+	      {
+		/* If we need to mark an insn in the middle of a
+		   libcall, we need to back up to mark the entire
+		   libcall.  Given that libcalls are rare, rescanning
+		   the block should be a reasonable solution to trying
+		   to figure out how to back up.  */
+ 		if (libcall_start)
+		  {
+		    mark_libcall (libcall_start, true);
+		    BITMAP_FREE (local_live);
+		    return dce_process_block (bb, false);
+		  }
+		else
+		  mark_insn (insn, true);
+	      }
 	  }
 	
 	/* No matter if the instruction is needed or not, we remove
@@ -534,15 +588,13 @@ fast_dce (bool df_delete)
      the in of one of their successors has changed.  */
   bitmap redo_out = BITMAP_ALLOC (NULL);
   bitmap all_blocks = BITMAP_ALLOC (NULL);
-  struct dataflow *dflow;
   bool global_changed = true;
+  struct dataflow * dflow = dce_df->problems_by_index[DF_LR];
   int n_blocks;
   int loop_count = 0;
 
   prescan_insns_for_dce (true);
 
-  dflow = dce_df->problems_by_index[DF_LR];
-
   n_blocks = post_order_compute (postorder, true);
   if (n_blocks != n_basic_blocks)
     delete_unreachable_blocks ();
@@ -558,7 +610,7 @@ fast_dce (bool df_delete)
 	  int index = postorder [i];
 	  basic_block bb = BASIC_BLOCK (index);
 	  bool local_changed 
-	    = dce_process_block (dflow, bb, bitmap_bit_p (redo_out, index));
+	    = dce_process_block (bb, bitmap_bit_p (redo_out, index));
 	  bitmap_set_bit (processed, index);
 	  
 	  if (local_changed)
@@ -613,6 +665,7 @@ fast_dce (bool df_delete)
 
   delete_unmarked_insns (df_delete);
 
+  free (postorder);
   BITMAP_FREE (processed);
   BITMAP_FREE (changed);
   BITMAP_FREE (redo_out);