diff --git a/arch/m32r/kernel/m32r_ksyms.c b/arch/m32r/kernel/m32r_ksyms.c
index b727e693c80508f59186b554eefff893bb699b0a..23f26f4adfff5d0d32674710724dda81b3a9bcf8 100644
--- a/arch/m32r/kernel/m32r_ksyms.c
+++ b/arch/m32r/kernel/m32r_ksyms.c
@@ -41,6 +41,9 @@ EXPORT_SYMBOL(cpu_data);
 EXPORT_SYMBOL(smp_flush_tlb_page);
 #endif
 
+extern int __ucmpdi2(unsigned long long a, unsigned long long b);
+EXPORT_SYMBOL(__ucmpdi2);
+
 /* compiler generated symbol */
 extern void __ashldi3(void);
 extern void __ashrdi3(void);
diff --git a/arch/m32r/lib/Makefile b/arch/m32r/lib/Makefile
index d16b4e40d1ae9746165756d21628594e0a7a7ca1..5889eb9610b5943ba28234c8533bd4f13add20e4 100644
--- a/arch/m32r/lib/Makefile
+++ b/arch/m32r/lib/Makefile
@@ -3,5 +3,5 @@
 #
 
 lib-y  := checksum.o ashxdi3.o memset.o memcpy.o \
-	  delay.o strlen.o usercopy.o csum_partial_copy.o
-
+	  delay.o strlen.o usercopy.o csum_partial_copy.o \
+	  ucmpdi2.o
diff --git a/arch/m32r/lib/libgcc.h b/arch/m32r/lib/libgcc.h
new file mode 100644
index 0000000000000000000000000000000000000000..267aa435bc35ddcfa90c51e1c5192379c4ec0778
--- /dev/null
+++ b/arch/m32r/lib/libgcc.h
@@ -0,0 +1,23 @@
+#ifndef __ASM_LIBGCC_H
+#define __ASM_LIBGCC_H
+
+#include <asm/byteorder.h>
+
+#ifdef __BIG_ENDIAN
+struct DWstruct {
+	int high, low;
+};
+#elif defined(__LITTLE_ENDIAN)
+struct DWstruct {
+	int low, high;
+};
+#else
+#error I feel sick.
+#endif
+
+typedef union {
+	struct DWstruct s;
+	long long ll;
+} DWunion;
+
+#endif /* __ASM_LIBGCC_H */
diff --git a/arch/m32r/lib/ucmpdi2.c b/arch/m32r/lib/ucmpdi2.c
new file mode 100644
index 0000000000000000000000000000000000000000..9d3c682c89b558f99833fe742e0d5d18e59f270a
--- /dev/null
+++ b/arch/m32r/lib/ucmpdi2.c
@@ -0,0 +1,17 @@
+#include "libgcc.h"
+
+int __ucmpdi2(unsigned long long a, unsigned long long b)
+{
+	const DWunion au = {.ll = a};
+	const DWunion bu = {.ll = b};
+
+	if ((unsigned int)au.s.high < (unsigned int)bu.s.high)
+		return 0;
+	else if ((unsigned int)au.s.high > (unsigned int)bu.s.high)
+		return 2;
+	if ((unsigned int)au.s.low < (unsigned int)bu.s.low)
+		return 0;
+	else if ((unsigned int)au.s.low > (unsigned int)bu.s.low)
+		return 2;
+	return 1;
+}