From 748e0b5c247c1cf5e1f3625dd7e29112fe92c7e5 Mon Sep 17 00:00:00 2001
From: Stephen Heumann <stephenheumann@gmail.com>
Date: Tue, 4 Jul 2017 12:39:11 -0500
Subject: [PATCH] Small optimizations for MD5.

---
 md5.asm    |  2 +-
 md5.macros | 35 +++++++++++++++++------------------
 2 files changed, 18 insertions(+), 19 deletions(-)

diff --git a/md5.asm b/md5.asm
index 02e362b..bfe2f74 100644
--- a/md5.asm
+++ b/md5.asm
@@ -27,7 +27,7 @@ b	gequ	16
 c	gequ	20
 d	gequ	24
 ;unused	gequ	28
-f_plus_a gequ	32
+;unused gequ	32
 temp	gequ	36
 h0	gequ	40
 h1	gequ	44
diff --git a/md5.macros b/md5.macros
index 8908c50..36aaf66 100644
--- a/md5.macros
+++ b/md5.macros
@@ -131,14 +131,14 @@
 	eor	&d
 	clc
 	adc	&a
-	sta	f_plus_a
+	sta	temp
 	
 	lda	&c+2
 	eor	&d+2
 	and	&b+2
 	eor	&d+2
 	adc	&a+2
-	sta	f_plus_a+2
+	sta	temp+2
 .skip1
 
 * f_16 to f_31
@@ -149,14 +149,14 @@
 	eor	&c
 	clc
 	adc	&a
-	sta	f_plus_a
+	sta	temp
 	
 	lda	&b+2
 	eor	&c+2
 	and	&d+2
 	eor	&c+2
 	adc	&a+2
-	sta	f_plus_a+2
+	sta	temp+2
 .skip2
 
 * f_32 to f_47
@@ -166,13 +166,13 @@
 	eor	&d
 	clc
 	adc	&a
-	sta	f_plus_a
+	sta	temp
 	
 	lda	&b+2
 	eor	&c+2
 	eor	&d+2
 	adc	&a+2
-	sta	f_plus_a+2
+	sta	temp+2
 .skip3
 
 * f_48 to f_63
@@ -183,27 +183,27 @@
 	eor	&c
 	clc
 	adc	&a
-	sta	f_plus_a
+	sta	temp
 	
 	lda	&d+2
 	eor	#$FFFF
 	ora	&b+2
 	eor	&c+2
 	adc	&a+2
-	sta	f_plus_a+2
+	sta	temp+2
 .skip4
 
 	ldy	idx
 	ldx	g_times_4,y
 	lda	m,x
 	clc
-	adc	f_plus_a
+	adc	temp
 	sta	temp
 	inx
 	inx
 	lda	m,x
-	adc	f_plus_a+2
-	sta	temp+2
+	adc	temp+2
+	tax
 	
 	lda	k,y
 	clc
@@ -211,10 +211,14 @@
 	sta	temp
 	iny
 	iny
-	lda	k,y
-	adc	temp+2
+	txa
+	adc	k,y
 	sta	temp+2
 	
+	iny
+	iny
+	sty	idx
+	
 	ROTL4	temp,&shift
 	
 	clc
@@ -225,11 +229,6 @@
 	adc	temp+2
 	sta	&a+2
 	
-	inc	idx
-	inc	idx
-	inc	idx
-	inc	idx
-	
 	mend