diff --git a/klibc/arch/cris/__negdi2.S b/klibc/arch/cris/__negdi2.S
new file mode 100644
index 0000000..3cca9ed
--- /dev/null
+++ b/klibc/arch/cris/__negdi2.S
@@ -0,0 +1,25 @@
+/*
+ * arch/cris/__negdi2.c
+ */
+
+/*
+ * In 2's complement arithmetric, -x == (~x + 1), so
+ * -{h,l} = (~{h,l} + {0,1)
+ * -{h,l} = {~h,~l} + {0,1}
+ * -{h,l} = {~h + cy, ~l + 1}
+ * ... where cy = (l == 0)
+ * -{h,l} = {~h + cy, -l}
+ */
+
+	.text
+	.balign 4
+	.type	__negdi2,@function
+	.globl	__negdi2
+__negdi2:
+	neg.d	$r10,$r10
+	seq	$r12
+	not	$r11
+	ret
+	  add.d	$r12,$r11
+
+	.size __negdi2, .-__negdi2
diff --git a/klibc/libgcc/__negdi2.c b/klibc/libgcc/__negdi2.c
deleted file mode 100644
index 60f2ed3..0000000
--- a/klibc/libgcc/__negdi2.c
+++ /dev/null
@@ -1,24 +0,0 @@
-#include <stdint.h>
-#include <stddef.h>
-
-struct DWstruct {int32_t low, high;};
-
-typedef union
-{
-  struct DWstruct s;
-  int64_t ll;
-} DWunion;
-
-
-__negdi2 (int64_t u)
-{
-  DWunion w;
-  DWunion uu;
-
-  uu.ll = u;
-
-  w.s.low = -uu.s.low;
-  w.s.high = -uu.s.high - ((uint32_t) w.s.low > 0);
-
-  return w.ll;
-}