Initial Contribution
diff --git a/libc/arch-x86/string/memset.S b/libc/arch-x86/string/memset.S
new file mode 100644
index 0000000..1059ccc
--- /dev/null
+++ b/libc/arch-x86/string/memset.S
@@ -0,0 +1,55 @@
+/* $OpenBSD: memset.S,v 1.3 2005/08/07 11:30:38 espie Exp $ */
+/*
+ * Written by J.T. Conklin <jtc@netbsd.org>.
+ * Public domain.
+ */
+
+#include <machine/asm.h>
+
+ENTRY(memset)
+ pushl %edi
+ pushl %ebx
+ movl 12(%esp),%edi
+ movzbl 16(%esp),%eax /* unsigned char, zero extend */
+ movl 20(%esp),%ecx
+ pushl %edi /* push address of buffer */
+
+ cld /* set fill direction forward */
+
+ /*
+ * if the string is too short, it's really not worth the overhead
+ * of aligning to word boundries, etc. So we jump to a plain
+ * unaligned set.
+ */
+ cmpl $0x0f,%ecx
+ jle L1
+
+ movb %al,%ah /* copy char to all bytes in word */
+ movl %eax,%edx
+ sall $16,%eax
+ orl %edx,%eax
+
+ movl %edi,%edx /* compute misalignment */
+ negl %edx
+ andl $3,%edx
+ movl %ecx,%ebx
+ subl %edx,%ebx
+
+ movl %edx,%ecx /* set until word aligned */
+ rep
+ stosb
+
+ movl %ebx,%ecx
+ shrl $2,%ecx /* set by words */
+ rep
+ stosl
+
+ movl %ebx,%ecx /* set remainder by bytes */
+ andl $3,%ecx
+L1: rep
+ stosb
+
+ popl %eax /* pop address of buffer */
+ popl %ebx
+ popl %edi
+ ret