From 2aa64be3a6928f79e445a73eb4998de6497b53b9 Mon Sep 17 00:00:00 2001
From: ceriel <none@none>
Date: Fri, 27 Mar 1987 09:55:28 +0000
Subject: [PATCH] Franks version

---
 mach/m68k4/libem/cms.s | 28 ++++++++++++++--------------
 mach/m68k4/libem/cmu.s | 37 +++++++++++++++++--------------------
 mach/m68k4/libem/exg.s | 30 +++++++++++-------------------
 3 files changed, 42 insertions(+), 53 deletions(-)

diff --git a/mach/m68k4/libem/cms.s b/mach/m68k4/libem/cms.s
index b6f4a5109..fa6d1b6b4 100644
--- a/mach/m68k4/libem/cms.s
+++ b/mach/m68k4/libem/cms.s
@@ -4,23 +4,23 @@
 .sect .data
 .sect .bss
 
+.sect .text
 	! d0 contains set size
-
-	.sect .text
+	! on exit d0 is zero for equal, non-zero for not equal
 .cms:
-	move.l	(sp)+,a2	! return address
-	move.l	sp,a0
-	move.l	sp,a1
-	add	d0,a1
-	move.w	d0,d1
-	asr	#1,d0
+	move.l	(sp)+, d2	! return address
+	move.l	sp, a0		! address of top block
+	lea	0(sp, d0.l), a1	! address of lower block
+	move.l	d0, d1
+	asr.l	#2, d0
 1:
-	cmp	(a0)+,(a1)+
+	cmp.l	(a0)+, (a1)+
 	bne	2f
-	sub.l	#1,d0
+	sub.l	#1, d0
 	bne	1b
 2:
-	asl	#1,d1
-	add	d1,sp
-	move.l	d0,-(sp)
-	jmp	(a2)
+	asl.l	#1, d1
+	add.l	d1, sp		! two blocks popped
+	move.l	d2, -(sp)
+	rts
+.align 2
diff --git a/mach/m68k4/libem/cmu.s b/mach/m68k4/libem/cmu.s
index 9f2051598..5228ed056 100644
--- a/mach/m68k4/libem/cmu.s
+++ b/mach/m68k4/libem/cmu.s
@@ -1,32 +1,29 @@
-.define .cmu
+.define	.cmu
 .sect .text
 .sect .rom
 .sect .data
 .sect .bss
 
-	! d0 : # bytes of 1 block
-	.sect .text
+.sect .text
+	! on entry d0: # bytes of 1 block
+	! on exit d0: result
 .cmu:
-	move.l	sp,a0		! top block
-	add.l	#4,a0
-	move.l	a0,a1
-	add.l	d0,a1		! lower block
-	move.l	d0,d2
-	asr.l	#2,d0
-	sub.l	#1,d0
-	move.l	#1,d1		! greater
+	move.l	(sp)+, d2	! return address
+	move.l	sp, a0		! address of top block
+	lea	0(sp, d0.l), a1	! address of lower block
+	move.l	d0, d1
+	asr.l	#2, d0
 1:
-	cmp.l	(a0)+,(a1)+
+	cmp.l	(a0)+, (a1)+
 	bne	2f
-	dbf	d0,1b
-	clr.l	d1		! equal
+	sub.l	#1, d0
+	bne	1b		! note: on equal carry is set
 2:
 	bcc	3f
-	neg.l	d1		! less
+	neg.l	d0		! less
 3:
-	asl.l	#1,d2
-	move.l	(sp)+,a0
-	add.l	d2,sp		! new sp
-	jmp	(a0)
-
+	asl.l	#1, d1
+	add.l	d1, sp		! new sp; two blocks popped
+	move.l	d2, -(sp)
+	rts
 .align 2
diff --git a/mach/m68k4/libem/exg.s b/mach/m68k4/libem/exg.s
index 396893b6e..18fd7c176 100644
--- a/mach/m68k4/libem/exg.s
+++ b/mach/m68k4/libem/exg.s
@@ -1,28 +1,20 @@
-.define .exg
+.define	.exg
 .sect .text
 .sect .rom
 .sect .data
 .sect .bss
 
+.sect .text
 	! d0 : exchange size in bytes
-	.sect .text
 .exg:
-	move.l	(sp)+,d2
-	move.l	sp,a1
-	sub.l	d0,sp
-	move.l	sp,a2
-	asr	#1,d0
-	move.l	d0,d1
+	lea	4(sp, d0), a0	! address of bottom block
+	lea	4(sp), a1	! address of top block
+	asr.l	#2, d0
+	sub.l	#1, d0
 1:
-	move.l	(a1)+,(a2)+
-	sub	#1,d0
-	bgt	1b
-	move.l	sp,a1
-	asr	#1,d1
-1:
-	move.l	(a1)+,(a2)+
-	sub	#1,d1
-	bgt	1b
-	move.l	a1,sp
-	move.l	d2,-(sp)
+	move.l	(a1), d1
+	move.l	(a0), (a1)+
+	move.l	d1, (a0)+
+	dbf	d0, 1b
 	rts
+.align 2