From 129f371902635f409f624a5b0cd3863ea1016c50 Mon Sep 17 00:00:00 2001
From: Stephen Heumann <stephenheumann@gmail.com>
Date: Tue, 4 Jul 2017 14:09:41 -0500
Subject: [PATCH] Add zero bytes to optimize some rotates in MD5.

---
 md5.asm    | 10 +++++++---
 md5.macros | 20 ++++----------------
 2 files changed, 11 insertions(+), 19 deletions(-)

diff --git a/md5.asm b/md5.asm
index ec34c77..2ef3899 100644
--- a/md5.asm
+++ b/md5.asm
@@ -26,9 +26,10 @@ a_	gequ	12	; elements of state
 b	gequ	16
 c	gequ	20
 d	gequ	24
-temp2	gequ	28
-;unused gequ	32
-temp	gequ	36
+zero1	gequ	28
+temp	gequ	30
+zero2	gequ	34
+;unused	gequ	36
 h0	gequ	40
 h1	gequ	44
 h2	gequ	48
@@ -96,6 +97,9 @@ MD5_INIT start
 	stz	length+4
 	stz	length+6
 	stz	extra
+	
+	stz	zero1
+	stz	zero2
 	rtl
 	end
 
diff --git a/md5.macros b/md5.macros
index 8c75ce6..8589e3c 100644
--- a/md5.macros
+++ b/md5.macros
@@ -141,11 +141,7 @@
 	aif	&n>7,.skip2
 	ldx	&loc+1
 	lda	&loc+3
-	and	#$00FF
-	sta	temp2
-	lda	&loc-1
-	and	#$FF00
-	ora	temp2
+	ora	&loc-1
 	sta	&loc
 	stx	&loc+2
 	txa
@@ -155,11 +151,7 @@
 	aif	&n>11,.skip3
 	ldx	&loc+1
 	lda	&loc+3
-	and	#$00FF
-	sta	temp2
-	lda	&loc-1
-	and	#$FF00
-	ora	temp2
+	ora	&loc-1
 	sta	&loc
 	stx	&loc+2
 	ROTL4CONT &loc,&n-8
@@ -180,7 +172,7 @@
 	sty	&loc
 	mexit
 .skip5
-	aif	&n>21,.skip6
+	aif	&n>20,.skip6
 	lda	&loc+2
 	ldy	&loc
 	sta	&loc
@@ -190,11 +182,7 @@
 .skip6
 	ldx	&loc+1
 	lda	&loc+3
-	and	#$00FF
-	sta	temp2
-	lda	&loc-1
-	and	#$FF00
-	ora	temp2
+	ora	&loc-1
 	sta	&loc+2
 	stx	&loc
 	ROTR4CONT &loc,24-&n