diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 1c5978c0338..24248158f13 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2000-11-17  Richard Henderson  <rth@redhat.com>
+
+	* config/alpha/elf.h (PREFERRED_DEBUGGING_TYPE): Set to DWARF2_DEBUG.
+	(ASM_SPEC): Disable and enable .mdebug based on -gstabs.
+	(ASM_FILE_START): Only write out ecoff .file directive if
+	emitting mdebug debugging.
+
 2000-11-17  Richard Henderson  <rth@redhat.com>
 
 	* configure.in (HAVE_AS_DWARF2_DEBUG_LINE): New.  Detect
diff --git a/gcc/config/alpha/elf.h b/gcc/config/alpha/elf.h
index 7676af4481c..8b0bf21a77d 100644
--- a/gcc/config/alpha/elf.h
+++ b/gcc/config/alpha/elf.h
@@ -27,7 +27,7 @@ Boston, MA 02111-1307, USA.    */
 #define DWARF2_DEBUGGING_INFO
 
 #undef  PREFERRED_DEBUGGING_TYPE
-#define PREFERRED_DEBUGGING_TYPE DBX_DEBUG
+#define PREFERRED_DEBUGGING_TYPE DWARF2_DEBUG
 
 #undef ASM_FINAL_SPEC
 
@@ -35,7 +35,7 @@ Boston, MA 02111-1307, USA.    */
 #define CC1_SPEC  "%{G*}"
 
 #undef  ASM_SPEC
-#define ASM_SPEC  "%{G*} %{relax:-relax} %{gdwarf*:-no-mdebug}"
+#define ASM_SPEC  "%{G*} %{relax:-relax} %{!gstabs*:-no-mdebug}%{gstabs*:-mdebug}"
 
 #undef  LINK_SPEC
 #define LINK_SPEC "-m elf64alpha %{G*} %{relax:-relax}		\
@@ -51,7 +51,7 @@ Boston, MA 02111-1307, USA.    */
 #undef  ASM_FILE_START
 #define ASM_FILE_START(FILE)					\
 do {								\
-  if (write_symbols != DWARF2_DEBUG)				\
+  if (write_symbols == DBX_DEBUG)				\
     {								\
       alpha_write_verstamp (FILE);				\
       output_file_directive (FILE, main_input_filename);	\