From cb4f60b2ff30b40a44c6c2e2652eb91f82e8bf33 Mon Sep 17 00:00:00 2001
From: drmortalwombat <90205530+drmortalwombat@users.noreply.github.com>
Date: Wed, 30 Mar 2022 20:05:09 +0200
Subject: [PATCH] Optimize muldiv8b8y

---
 include/fixmath.c | 26 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/include/fixmath.c b/include/fixmath.c
index a040424..4a6d493 100644
--- a/include/fixmath.c
+++ b/include/fixmath.c
@@ -517,14 +517,31 @@ unsigned lmuldiv8by8(char a, char b, char c)
 		sty	accu + 1
 		sty	accu + 2
 
-		ldx #16
+		lda a
+		beq	z1
+		lda c
+		beq	z1
+
+		ldx #8
+		lda	b
+		beq	z1
+
+		cmp c
+		bcc w0
+	l1:
+		lsr
+		ror accu + 1
+		inx
+		cmp c
+		bcs l1
+		bcc	wa
+
 	l2:
 		asl accu + 2
 		rol accu + 0
+	wa:
 		rol accu + 1
-
-		tya
-		asl	b
+	w0:
 		rol
 
 		bcc w2
@@ -547,6 +564,7 @@ unsigned lmuldiv8by8(char a, char b, char c)
 		bne w1
 		inc accu + 1
 	w1:
+		tya
 
 		dex
 		bne l2