From 49ffb1065bc9ec2335e621eba2c025eb01cf5a3a Mon Sep 17 00:00:00 2001
From: Stephen Heumann <stephenheumann@gmail.com>
Date: Mon, 26 Feb 2024 22:14:59 -0600
Subject: [PATCH] Unroll the core loop of strlen one time.

This makes the core loop about 10% faster at the cost of 5 extra code bytes, which seems like a reasonable tradeoff.
---
 string.asm | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/string.asm b/string.asm
index e382f43..d2c1147 100644
--- a/string.asm
+++ b/string.asm
@@ -961,6 +961,9 @@ str      equ   4                        pointer to the string
          tyx                             null
          short M
 lb1      lda   [str],Y
+         beq   lb2
+         iny
+         lda   [str],Y
          beq   lb2
          iny
          bne   lb1