diff --git a/sys/sparc64/sparc64/support.S b/sys/sparc64/sparc64/support.S
index bba97b580a3c..5b9dd68d110a 100644
--- a/sys/sparc64/sparc64/support.S
+++ b/sys/sparc64/sparc64/support.S
@@ -206,6 +206,30 @@ __FBSDID("$FreeBSD$");
 	 inc	dst ; \
 6:
 
+/*
+ * Extension of _MEMCPY dealing with overlap, but unaware of ASIs.
+ * Used for bcopy() and memmove().
+ */
+#define	_MEMMOVE(dst, src, len) \
+	/* Check for overlap, and copy backwards if so. */ \
+	sub	dst, src, %g1 ; \
+	cmp	%g1, len ; \
+	bgeu,a,pt %xcc, 2f ; \
+	 nop ; \
+	/* Copy backwards. */ \
+	add	src, len, src ; \
+	add	dst, len, dst ; \
+1:	deccc	1, len ; \
+	bl,pn	%xcc, 3f ; \
+	 dec	1, src ; \
+	ldub	[src], %g1 ; \
+	dec	1, dst ; \
+	ba	%xcc, 1b ; \
+	 stb	%g1, [dst] ; \
+2:	/* Do the fast version. */ \
+	_MEMCPY(dst, src, len, EMPTY, EMPTY, EMPTY, EMPTY) ; \
+3:
+
 /*
  * void ascopy(u_long asi, vm_offset_t src, vm_offset_t dst, size_t len)
  */
@@ -265,48 +289,13 @@ ENTRY(bcmp)
 END(bcmp)
 
 /*
- * void *memmove(void *dst, const void *src, size_t len)
  * void bcopy(const void *src, void *dst, size_t len)
  */
-ENTRY(memmove)
-	/*
-	 * Swap src/dst for memmove/bcopy differences
-	 */
-	mov	%o0, %o6
-	mov	%o1, %o0
-	mov	%o6, %o1
-ALTENTRY(bcopy)
-	/*
-	 * Check for overlap, and copy backwards if so.
-	 */
-	sub	%o1, %o0, %g1
-	cmp	%g1, %o2
-	bgeu,a,pt %xcc, 3f
-	 nop
-
-	/*
-	 * Copy backwards.
-	 */
-	add	%o0, %o2, %o0
-	add	%o1, %o2, %o1
-1:	deccc	1, %o2
-	bl,a,pn	%xcc, 2f
-	 nop
-	dec	1, %o0
-	ldub	[%o0], %g1
-	dec	1, %o1
-	ba	%xcc, 1b
-	 stb	%g1, [%o1]
-2:	retl
-	 mov	%o6, %o0
-
-	/*
-	 * Do the fast version.
-	 */
-3:	_MEMCPY(%o1, %o0, %o2, EMPTY, EMPTY, EMPTY, EMPTY)
+ENTRY(bcopy)
+	_MEMMOVE(%o1, %o0, %o2)
 	retl
-	 mov	%o6, %o0
-END(memmove)
+	 nop
+END(bcopy)
 
 /*
  * void bzero(void *b, size_t len)
@@ -336,6 +325,16 @@ ENTRY(memcpy)
 	 nop
 END(memcpy)
 
+/*
+ * void *memmove(void *dst, const void *src, size_t len)
+ */
+ENTRY(memmove)
+	mov	%o0, %o3
+	_MEMMOVE(%o3, %o1, %o2)
+	retl
+	 nop
+END(memmove)
+
 /*
  * void *memset(void *b, int c, size_t len)
  */