1 files changed, 30 insertions, 0 deletions
diff --git a/klibc/klibc/memset.c b/klibc/klibc/memset.c
new file mode 100644
index 0000000000..522cc59a1e
--- /dev/null
+++ b/klibc/klibc/memset.c
@@ -0,0 +1,30 @@
+/*
+ * memset.c
+ */
+
+#include <string.h>
+#include <stdint.h>
+
+void *memset(void *dst, int c, size_t n)
+{
+  char *q = dst;
+
+#if defined(__i386__)
+  size_t nl = n >> 2;
+  asm volatile("cld ; rep ; stosl ; movl %3,%0 ; rep ; stosb"
+	       : "+c" (nl), "+D" (q)
+	       : "a" ((unsigned char)c * 0x01010101U), "r" (n & 3));
+#elif defined(__x86_64__)
+  size_t nq = n >> 3;
+  asm volatile("cld ; rep ; stosq ; movl %3,%%ecx ; rep ; stosb"
+	       : "+c" (nq), "+D" (q)
+	       : "a" ((unsigned char)c * 0x0101010101010101U),
+	       "r" ((uint32_t)n & 7));
+#else
+  while ( n-- ) {
+    *q++ = c;
+  }
+#endif
+
+  return dst;
+}