Index: include/elf/dwarf2.h
===================================================================
RCS file: /cvs/src/src/include/elf/dwarf2.h,v
retrieving revision 1.24
diff -u -p -r1.24 dwarf2.h
--- include/elf/dwarf2.h	24 Sep 2008 23:21:04 -0000	1.24
+++ include/elf/dwarf2.h	21 Apr 2009 01:15:27 -0000
@@ -709,6 +709,7 @@ enum dwarf_line_number_x_ops
     DW_LNE_end_sequence = 1,
     DW_LNE_set_address = 2,
     DW_LNE_define_file = 3,
+    DW_LNE_set_discriminator = 4,
     /* HP extensions.  */
     DW_LNE_HP_negate_is_UV_update      = 0x11,
     DW_LNE_HP_push_context             = 0x12,
Index: gas/dwarf2dbg.c
===================================================================
RCS file: /cvs/src/src/gas/dwarf2dbg.c,v
retrieving revision 1.100
diff -u -p -r1.100 dwarf2dbg.c
--- gas/dwarf2dbg.c	3 Mar 2009 10:04:58 -0000	1.100
+++ gas/dwarf2dbg.c	21 Apr 2009 01:15:27 -0000
@@ -25,7 +25,8 @@
 
 	.file FILENO "file.c"
 	.loc  FILENO LINENO [COLUMN] [basic_block] [prologue_end] \
-	      [epilogue_begin] [is_stmt VALUE] [isa VALUE]
+	      [epilogue_begin] [is_stmt VALUE] [isa VALUE] \
+	      [discriminator VALUE]
 */
 
 #include "as.h"
@@ -194,7 +195,8 @@ bfd_boolean dwarf2_loc_mark_labels;
 /* Current location as indicated by the most recent .loc directive.  */
 static struct dwarf2_line_info current = {
   1, 1, 0, 0,
-  DWARF2_LINE_DEFAULT_IS_STMT ? DWARF2_FLAG_IS_STMT : 0
+  DWARF2_LINE_DEFAULT_IS_STMT ? DWARF2_FLAG_IS_STMT : 0,
+  0
 };
 
 /* The size of an address on the target.  */
@@ -331,6 +333,7 @@ dwarf2_where (struct dwarf2_line_info *l
       line->column = 0;
       line->flags = DWARF2_FLAG_IS_STMT;
       line->isa = current.isa;
+      line->discriminator = current.discriminator;
     }
   else
     *line = current;
@@ -379,6 +382,7 @@ dwarf2_consume_line_info (void)
   current.flags &= ~(DWARF2_FLAG_BASIC_BLOCK
 		     | DWARF2_FLAG_PROLOGUE_END
 		     | DWARF2_FLAG_EPILOGUE_BEGIN);
+  current.discriminator = 0;
 }
 
 /* Called for each (preferably code) label.  If dwarf2_loc_mark_labels
@@ -581,6 +585,7 @@ dwarf2_directive_loc (int dummy ATTRIBUT
 
   current.filenum = filenum;
   current.line = line;
+  current.discriminator = 0;
 
 #ifndef NO_LISTING
   if (listing)
@@ -659,6 +664,18 @@ dwarf2_directive_loc (int dummy ATTRIBUT
 	      return;
 	    }
 	}
+      else if (strcmp (p, "discriminator") == 0)
+	{
+	  *input_line_pointer = c;
+	  value = get_absolute_expression ();
+	  if (value >= 0)
+	    current.discriminator = value;
+	  else
+	    {
+	      as_bad (_("discriminator less than zero"));
+	      return;
+	    }
+	}
       else
 	{
 	  as_bad (_("unknown .loc sub-directive `%s'"), p);
@@ -748,6 +765,14 @@ out_uleb128 (addressT value)
   output_leb128 (frag_more (sizeof_leb128 (value, 0)), value, 0);
 }
 
+/* Emit a signed "little-endian base 128" number.  */
+
+static void
+out_leb128 (addressT value)
+{
+  output_leb128 (frag_more (sizeof_leb128 (value, 1)), value, 1);
+}
+
 /* Emit a tuple for .debug_abbrev.  */
 
 static inline void
@@ -1208,6 +1233,14 @@ process_entries (segT seg, struct line_e
 	  out_uleb128 (column);
 	}
 
+      if (e->loc.discriminator != 0)
+	{
+	  out_opcode (DW_LNS_extended_op);
+	  out_leb128 (1 + sizeof_leb128 (e->loc.discriminator, 0));
+	  out_opcode (DW_LNE_set_discriminator);
+	  out_uleb128 (e->loc.discriminator);
+	}
+
       if (isa != e->loc.isa)
 	{
 	  isa = e->loc.isa;
Index: gas/dwarf2dbg.h
===================================================================
RCS file: /cvs/src/src/gas/dwarf2dbg.h,v
retrieving revision 1.22
diff -u -p -r1.22 dwarf2dbg.h
--- gas/dwarf2dbg.h	15 Jan 2009 12:42:52 -0000	1.22
+++ gas/dwarf2dbg.h	21 Apr 2009 01:15:27 -0000
@@ -34,6 +34,7 @@ struct dwarf2_line_info {
   unsigned int column;
   unsigned int isa;
   unsigned int flags;
+  unsigned int discriminator;
 };
 
 /* Implements the .file FILENO "FILENAME" directive.  FILENO can be 0