[MIPS] Add __ucmpdi2 implementation

Recent GCC SVN versions may generate calls to __ucmpdi2.

Signed-off-by: Thiemo Seufer <ths@networkno.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

2 files changed, 20 insertions, 1 deletions

diff --git a/arch/mips/lib/Makefile b/arch/mips/lib/Makefile
index d7d3b14dcfb2..5dad13efba7e 100644
--- a/arch/mips/lib/Makefile
+++ b/arch/mips/lib/Makefile
@@ -9,4 +9,4 @@ obj-y			+= iomap.o
 obj-$(CONFIG_PCI)       += iomap-pci.o
 
 # libgcc-style stuff needed in the kernel
-lib-y += ashldi3.o ashrdi3.o lshrdi3.o
+lib-y += ashldi3.o ashrdi3.o lshrdi3.o ucmpdi2.o
diff --git a/arch/mips/lib/ucmpdi2.c b/arch/mips/lib/ucmpdi2.c
new file mode 100644
index 000000000000..e9ff258ef028
--- /dev/null
+++ b/arch/mips/lib/ucmpdi2.c
@@ -0,0 +1,19 @@
+#include <linux/module.h>
+
+#include "libgcc.h"
+
+word_type __ucmpdi2 (unsigned long a, unsigned 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;
+}