auto import from //depot/cupcake/@135843
diff --git a/libc/arch-x86/string/strcpy.S b/libc/arch-x86/string/strcpy.S
new file mode 100644
index 0000000..341eb6c
--- /dev/null
+++ b/libc/arch-x86/string/strcpy.S
@@ -0,0 +1,63 @@
+/* $OpenBSD: strcpy.S,v 1.8 2005/08/07 11:30:38 espie Exp $ */
+/*
+ * Written by J.T. Conklin <jtc@netbsd.org>.
+ * Public domain.
+ */
+
+#include <machine/asm.h>
+
+#if defined(APIWARN)
+#APP
+ .section .gnu.warning.strcpy
+ .ascii "warning: strcpy() is almost always misused, please use strlcpy()"
+#NO_APP
+#endif
+
+/*
+ * NOTE: I've unrolled the loop eight times: large enough to make a
+ * significant difference, and small enough not to totally trash the
+ * cache.
+ */
+
+ENTRY(strcpy)
+ movl 4(%esp),%ecx /* dst address */
+ movl 8(%esp),%edx /* src address */
+ pushl %ecx /* push dst address */
+
+ .align 2,0x90
+L1: movb (%edx),%al /* unroll loop, but not too much */
+ movb %al,(%ecx)
+ testb %al,%al
+ jz L2
+ movb 1(%edx),%al
+ movb %al,1(%ecx)
+ testb %al,%al
+ jz L2
+ movb 2(%edx),%al
+ movb %al,2(%ecx)
+ testb %al,%al
+ jz L2
+ movb 3(%edx),%al
+ movb %al,3(%ecx)
+ testb %al,%al
+ jz L2
+ movb 4(%edx),%al
+ movb %al,4(%ecx)
+ testb %al,%al
+ jz L2
+ movb 5(%edx),%al
+ movb %al,5(%ecx)
+ testb %al,%al
+ jz L2
+ movb 6(%edx),%al
+ movb %al,6(%ecx)
+ testb %al,%al
+ jz L2
+ movb 7(%edx),%al
+ movb %al,7(%ecx)
+ addl $8,%edx
+ addl $8,%ecx
+ testb %al,%al
+ jnz L1
+L2: popl %eax /* pop dst address */
+ ret