--- a/arch/mips/include/asm/string.h
+++ b/arch/mips/include/asm/string.h
@@ -133,11 +133,44 @@ strncmp(__const__ char *__cs, __const__
 
 #define __HAVE_ARCH_MEMSET
 extern void *memset(void *__s, int __c, size_t __count);
+#define memset(__s, __c, len)					\
+({								\
+	size_t __len = (len);					\
+	void *__ret;						\
+	if (__builtin_constant_p(len) && __len >= 64)		\
+		__ret = memset((__s), (__c), __len);		\
+	else							\
+		__ret = __builtin_memset((__s), (__c), __len);	\
+	__ret;							\
+})
 
 #define __HAVE_ARCH_MEMCPY
 extern void *memcpy(void *__to, __const__ void *__from, size_t __n);
+#define memcpy(dst, src, len)					\
+({								\
+	size_t __len = (len);					\
+	void *__ret;						\
+	if (__builtin_constant_p(len) && __len >= 64)		\
+		__ret = memcpy((dst), (src), __len);		\
+	else							\
+		__ret = __builtin_memcpy((dst), (src), __len);	\
+	__ret;							\
+})
 
 #define __HAVE_ARCH_MEMMOVE
 extern void *memmove(void *__dest, __const__ void *__src, size_t __n);
+#define memmove(dst, src, len)					\
+({								\
+	size_t __len = (len);					\
+	void *__ret;						\
+	if (__builtin_constant_p(len) && __len >= 64)		\
+		__ret = memmove((dst), (src), __len);		\
+	else							\
+		__ret = __builtin_memmove((dst), (src), __len);	\
+	__ret;							\
+})
+
+#define __HAVE_ARCH_MEMCMP
+#define memcmp(src1, src2, len) __builtin_memcmp((src1), (src2), (len))
 
 #endif /* _ASM_STRING_H */
--- a/arch/mips/lib/Makefile
+++ b/arch/mips/lib/Makefile
@@ -3,7 +3,7 @@
 #
 
 lib-y	+= csum_partial.o delay.o memcpy.o memcpy-inatomic.o memset.o \
-	   strlen_user.o strncpy_user.o strnlen_user.o uncached.o
+	   strlen_user.o strncpy_user.o strnlen_user.o uncached.o memcmp.o
 
 obj-y			+= iomap.o
 obj-$(CONFIG_PCI)	+= iomap-pci.o
--- /dev/null
+++ b/arch/mips/lib/memcmp.c
@@ -0,0 +1,22 @@
+/*
+ *  copied from linux/lib/string.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+
+#undef memcmp
+int memcmp(const void *cs, const void *ct, size_t count)
+{
+	const unsigned char *su1, *su2;
+	int res = 0;
+
+	for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
+		if ((res = *su1 - *su2) != 0)
+			break;
+	return res;
+}
+EXPORT_SYMBOL(memcmp);
+
