diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c140b0e97be..55b0b15f045 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2000-02-01  David Billinghurst <David.Billinghurst@riotinto.com.au> 
+
+	* config/mips/iris6.h (SUBTARGET_ASM_SPEC) : Default ISA based
+	on ABI.
+
 Tue Feb  1 00:57:40 2000  Hans-Peter Nilsson  <hp@bitrange.com>
 
 	* dwarfout.c (SHORT_TYPE_SIZE): Correct default.
diff --git a/gcc/config/mips/iris6.h b/gcc/config/mips/iris6.h
index 01b0c1c71ff..44f6ac8765f 100644
--- a/gcc/config/mips/iris6.h
+++ b/gcc/config/mips/iris6.h
@@ -219,8 +219,9 @@ Boston, MA 02111-1307, USA.  */
 
 /* ??? If no mabi=X option give, but a mipsX option is, then should depend
    on the mipsX option.  */
+/* If no mips[3,4] option given, give the appropriate default for mabi=X */
 #undef SUBTARGET_ASM_SPEC
-#define SUBTARGET_ASM_SPEC "%{!mabi*:-n32}"
+#define SUBTARGET_ASM_SPEC "%{!mabi*:-n32} %{!mips*: %{!mabi*:-mips3} %{mabi=n32:-mips3} %{mabi=64:-mips4}}"
 
 /* Must pass -g0 to the assembler, otherwise it may overwrite our
    debug info with its own debug info. */