--- old-xen-build/xen/include/asm-x86/x86_64/string.h	2005-05-02 18:29:44.000000000 +0000
+++ new-xen-build/xen/include/asm-x86/x86_64/string.h	2005-05-04 23:12:53.000000000 +0000
@@ -3,7 +3,29 @@
 
 #define __HAVE_ARCH_MEMMOVE
 #define memmove(dest,src,n) (__memmove((dest),(src),(n)))
-#define __memmove(dest,src,n) (__builtin_memmove((dest),(src),(n)))
+static inline void *__memmove(void * dest,const void * src, size_t n)
+{
+int d0, d1, d2;
+if (dest<src)
+__asm__ __volatile__(
+	"rep\n\t"
+	"movsb"
+	: "=&c" (d0), "=&S" (d1), "=&D" (d2)
+	:"0" (n),"1" (src),"2" (dest)
+	: "memory");
+else
+__asm__ __volatile__(
+	"std\n\t"
+	"rep\n\t"
+	"movsb\n\t"
+	"cld"
+	: "=&c" (d0), "=&S" (d1), "=&D" (d2)
+	:"0" (n),
+	 "1" (n-1+(const char *)src),
+	 "2" (n-1+(char *)dest)
+	:"memory");
+return dest;
+}
 
 #define __HAVE_ARCH_MEMCPY
 #define memcpy(t,f,n) (__memcpy((t),(f),(n)))