1 files changed, 21 insertions, 0 deletions
diff --git a/string.s b/string.s
new file mode 100644
index 0000000..b6bc317
--- /dev/null
+++ b/string.s
@@ -0,0 +1,21 @@
+.include "lib.s"
+
+.globl strlen
+strlen:
+	prologue
+
+	backup %rdi, %rcx
+
+	movq 16(%rbp), %rdi
+	xorq %rax, %rax
+	movq $-1, %rcx
+
+	repne scasb
+
+	movq $-2, %rax
+	subq %rcx, %rax
+
+	restore %rdi, %rcx
+
+	leave
+	ret