lto-streamer-in.c (lto_input_location): Try to reuse previous maps.

2009-10-17  Richard Guenther  <rguenther@suse.de>

	* lto-streamer-in.c (lto_input_location): Try to reuse
	previous maps.

From-SVN: r152953

gcc/ChangeLog

 2009-10-17  Richard Guenther  <rguenther@suse.de>
 
+	* lto-streamer-in.c (lto_input_location): Try to reuse
+	previous maps.
+
+2009-10-17  Richard Guenther  <rguenther@suse.de>
+
 	* lto-streamer-in.c (input_gimple_stmt): Fixup FIELD_DECL
 	operands in COMPONENT_REFs.
 

gcc/lto-streamer-in.c

@@ -274,26 +274,30 @@ static location_t
 lto_input_location (struct lto_input_block *ib, struct data_in *data_in)
 {
   expanded_location xloc;
-  location_t loc;
 
   xloc.file = input_string (data_in, ib);
   if (xloc.file == NULL)
     return UNKNOWN_LOCATION;
 
+  xloc.file = canon_file_name (xloc.file);
   xloc.line = lto_input_sleb128 (ib);
   xloc.column = lto_input_sleb128 (ib);
 
-  if (data_in->current_file)
-    linemap_add (line_table, LC_LEAVE, false, NULL, 0);
+  if (data_in->current_file != xloc.file)
+    {
+      if (data_in->current_file)
+	linemap_add (line_table, LC_LEAVE, false, NULL, 0);
 
-  data_in->current_file = canon_file_name (xloc.file);
+      linemap_add (line_table, LC_ENTER, false, xloc.file, xloc.line);
+    }
+  else if (data_in->current_line != xloc.line)
+    linemap_line_start (line_table, xloc.line, xloc.column);
+
+  data_in->current_file = xloc.file;
   data_in->current_line = xloc.line;
   data_in->current_col = xloc.column;
 
-  linemap_add (line_table, LC_ENTER, false, data_in->current_file, xloc.line);
-  LINEMAP_POSITION_FOR_COLUMN (loc, line_table, xloc.column);
-
-  return loc;
+  return linemap_position_for_column (line_table, xloc.column);
 }