[MIPS] Add __cmpdi2

Certain 32-bit kernel configurations seem to be able to cause references,
this was observed with gcc 4.1.2.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

2 files changed, 28 insertions, 1 deletions

diff --git a/arch/mips/lib/Makefile b/arch/mips/lib/Makefile
index 91ed1eb3310..8810dfb915d 100644
--- a/arch/mips/lib/Makefile
+++ b/arch/mips/lib/Makefile
@@ -28,4 +28,4 @@ obj-$(CONFIG_CPU_TX49XX)	+= dump_tlb.o
 obj-$(CONFIG_CPU_VR41XX)        += dump_tlb.o
 
 # libgcc-style stuff needed in the kernel
-obj-y += ashldi3.o ashrdi3.o lshrdi3.o ucmpdi2.o
+obj-y += ashldi3.o ashrdi3.o cmpdi2.o lshrdi3.o ucmpdi2.o
diff --git a/arch/mips/lib/cmpdi2.c b/arch/mips/lib/cmpdi2.c
new file mode 100644
index 00000000000..8c1306437ed
--- /dev/null
+++ b/arch/mips/lib/cmpdi2.c
@@ -0,0 +1,27 @@
+#include <linux/module.h>
+
+#include "libgcc.h"
+
+word_type __cmpdi2(long long a, long long b)
+{
+        const DWunion au = {
+                .ll = a
+        };
+        const DWunion bu = {
+                .ll = b
+        };
+
+        if (au.s.high < bu.s.high)
+                return 0;
+        else if (au.s.high > 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;
+}
+
+EXPORT_SYMBOL(__cmpdi2);