1 files changed, 34 insertions, 0 deletions
diff --git a/klibc/klibc/memmove.c b/klibc/klibc/memmove.c
new file mode 100644
index 0000000000..c1f042af39
--- /dev/null
+++ b/klibc/klibc/memmove.c
@@ -0,0 +1,34 @@
+/*
+ * memmove.c
+ */
+
+#include <string.h>
+
+void *memmove(void *dst, const void *src, size_t n)
+{
+  const char *p = src;
+  char *q = dst;
+#if defined(__i386__) || defined(__x86_64__)
+  if ( q < p ) {
+    asm volatile("cld ; rep ; movsb" : "+c" (n), "+S" (p), "+D" (q));
+  } else {
+    p += (n-1);
+    q += (n-1);
+    asm volatile("std ; rep ; movsb" : "+c" (n), "+S" (p), "+D" (q));
+  }
+#else
+  if ( q < p ) {
+    while ( n-- ) {
+      *q++ = *p++;
+    }
+  } else {
+    p += n;
+    q += n;
+    while ( n-- ) {
+      *--q = *--p;
+    }
+  }
+#endif
+
+  return dst;
+}