diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index 1235b04..1c273be 100644
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -164,18 +164,19 @@
 	retq
 	.p2align 4
 .Lless_3bytes:
-	cmpl $0, %edx
-	je .Lend
+	subl $1, %edx
+	jb .Lend
 	/*
 	 * Move data from 1 bytes to 3 bytes.
 	 */
-.Lloop_1:
-	movb (%rsi), %r8b
-	movb %r8b, (%rdi)
-	incq %rdi
-	incq %rsi
-	decl %edx
-	jnz .Lloop_1
+	movzbl (%rsi), %ecx
+	jz .Lstore_1byte
+	movzbq 1(%rsi), %r8
+	movzbq (%rsi, %rdx), %r9
+	movb %r8b, 1(%rdi)
+	movb %r9b, (%rdi, %rdx)
+.Lstore_1byte:
+	movb %cl, (%rdi)
 
 .Lend:
 	retq