diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 69995383256..ba78b2cb4be 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2005-01-03  Eric Botcazou  <ebotcazou@libertysurf.fr>
+
+	* config/sparc/sparc.h (SPARC_RELAXED_ORDERING): Define to false.
+	* config/sparc/linux.h (SPARC_RELAXED_ORDERING): Define to true.
+	* config/sparc/linux64.h (SPARC_RELAXED_ORDERING): Likewise.
+	* config/sparc/sparc.c (TARGET_RELAXED_ORDERING): Define to
+	SPARC_RELAXED_ORDERING.
+
 2005-01-03  Richard Henderson  <rth@redhat.com>
 	    Uros Bizjak  <uros@kss-loka.si>
 
diff --git a/gcc/config/sparc/linux.h b/gcc/config/sparc/linux.h
index 2116cb4adbf..ec95ae6e30d 100644
--- a/gcc/config/sparc/linux.h
+++ b/gcc/config/sparc/linux.h
@@ -234,3 +234,9 @@ do {									\
 #endif
 
 #define MD_UNWIND_SUPPORT "config/sparc/linux-unwind.h"
+
+/* Linux currently uses RMO in uniprocessor mode, which is equivalent to
+   TMO, and TMO in multiprocessor mode.  But they reserve the right to
+   change their minds.  */
+#undef SPARC_RELAXED_ORDERING
+#define SPARC_RELAXED_ORDERING true
diff --git a/gcc/config/sparc/linux64.h b/gcc/config/sparc/linux64.h
index 0b91659abd2..deaea779586 100644
--- a/gcc/config/sparc/linux64.h
+++ b/gcc/config/sparc/linux64.h
@@ -371,3 +371,9 @@ do {									\
 #endif
 
 #define MD_UNWIND_SUPPORT "config/sparc/linux-unwind.h"
+
+/* Linux currently uses RMO in uniprocessor mode, which is equivalent to
+   TMO, and TMO in multiprocessor mode.  But they reserve the right to
+   change their minds.  */
+#undef SPARC_RELAXED_ORDERING
+#define SPARC_RELAXED_ORDERING true
diff --git a/gcc/config/sparc/sparc.c b/gcc/config/sparc/sparc.c
index c15a406d1f9..5415beaf7f8 100644
--- a/gcc/config/sparc/sparc.c
+++ b/gcc/config/sparc/sparc.c
@@ -498,20 +498,8 @@ enum processor_type sparc_cpu;
 #define TARGET_ATTRIBUTE_TABLE sparc_attribute_table
 #endif
 
-/* The SPARC v9 architecture defines a relaxed memory ordering model (RMO)
-   which requires this if enabled.  Prior to v9, there are no instructions
-   to even talk about memory syncronization.  The Ultra3 processor doesn't
-   implement RMO.
-
-   Solaris never enables RMO; only ever uses total memory ordering (TMO.
-
-   Linux currently uses RMO in uniprocessor mode, which is equivalent to
-   TMO, and TMO in multiprocessor mode.  But they reserve the right to
-   change their minds.  */
-/* ??? Getting the configury correct is harder than it's worth.  Just
-   enable it all the time.  */
 #undef TARGET_RELAXED_ORDERING
-#define TARGET_RELAXED_ORDERING true
+#define TARGET_RELAXED_ORDERING SPARC_RELAXED_ORDERING
 
 struct gcc_target targetm = TARGET_INITIALIZER;
 
diff --git a/gcc/config/sparc/sparc.h b/gcc/config/sparc/sparc.h
index 3b6ea6c67ef..673b1da854f 100644
--- a/gcc/config/sparc/sparc.h
+++ b/gcc/config/sparc/sparc.h
@@ -204,6 +204,16 @@ extern enum cmodel sparc_cmodel;
 
 #define SPARC_DEFAULT_CMODEL CM_32
 
+/* The SPARC-V9 architecture defines a relaxed memory ordering model (RMO)
+   which requires the following macro to be true if enabled.  Prior to V9,
+   there are no instructions to even talk about memory synchronization.
+   Note that the UltraSPARC III processors don't implement RMO, unlike the
+   UltraSPARC II processors.
+
+   Default to false; for example, Solaris never enables RMO, only ever uses
+   total memory ordering (TMO).  */
+#define SPARC_RELAXED_ORDERING false
+
 /* This is call-clobbered in the normal ABI, but is reserved in the
    home grown (aka upward compatible) embedded ABI.  */
 #define EMBMEDANY_BASE_REG "%g4"