From: Dennis Ritchie <dmr@research.uucp>
Date: Mon, 17 Jan 1972 17:53:35 +0000 (-0500)
Subject: Research V2 development
X-Git-Tag: Research-V2~70
X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/commitdiff_plain/ba369452fba521e1cd977a4e960d45d5a29f565b

Research V2 development
Work on file cmd/cmp.s

Synthesized-from: v2
---

diff --git a/cmd/cmp.s b/cmd/cmp.s
new file mode 100644
index 0000000000..fa0febbbd4
--- /dev/null
+++ b/cmd/cmp.s
@@ -0,0 +1,133 @@
+/ cmp -- compare files
+
+
+	cmp	(sp)+,$3
+	beq	1f
+	jsr	r5,mesg; <Usage: cmp arg1 arg2\n\0>; .even
+	sys	exit
+1:
+	tst	(sp)+
+	mov	(sp)+,0f
+	sys	open; 0:..; 0
+	bec	1f
+	jsr	r5,mesg; <Can't open arg1.\n\0>; .even
+	sys	exit
+1:
+	mov	r0,f1
+	mov	(sp)+,0f
+	sys	open; 0:..; 0
+	bec	1f
+	jsr	r5,mesg; <Can't open arg2.\n\0>; .even
+	sys	exit
+1:
+	mov	r0,f2
+	clr	r2
+1:
+	jsr	r5,getw; f1
+	bvs	eof1
+	mov	r0,r3
+	jsr	r5,getw; f2
+	bvs	eof2
+	cmp	r0,r3
+	beq	2f
+	mov	r0,r4
+	mov	r2,r0
+	jsr	pc,octal
+	jsr	r5,mesg; <: \0>; .even
+	mov	r3,r0
+	jsr	pc,octal
+	jsr	r5,mesg; < \0>;
+	mov	r4,r0
+	jsr	pc,octal
+	jsr	r5,mesg; <\n\0>
+2:
+	add	$2,r2
+	br	1b
+eof1:
+	jsr	r5,getw; f2
+	bvs	1f
+	jsr	r5,mesg; <EOF on arg1.\n\0>; .even
+	sys	exit
+1:
+	sys	exit
+
+eof2:
+	jsr	r5,mesg; <EOF on arg2.\n\0>; .even
+	sys	exit
+
+mesg:
+	movb	(r5)+,ch
+	beq	1f
+	mov	$1,r0
+	sys	write; ch; 1
+	br	mesg
+1:
+	inc	r5
+	bic	$1,r5
+	rts	r5
+
+getw:
+	mov	(r5)+,r1
+	cmp	2(r1),$1
+	bne	1f
+	mov	*4(r1),r0
+	bic	$!377,r0
+	dec	2(r1)
+	rts	r5
+1:
+	sub	$2,2(r1)
+	bge	1f
+	mov	(r1),r0
+	mov	r1,0f
+	add	$6,0f
+	sys	read; 0:..; 512.
+	mov	r0,2(r1)
+	bne	2f
+	sev
+	rts	r5
+2:
+	mov	r1,4(r1)
+	add	$6,4(r1)
+	sub	$2,2(r1)
+1:
+	mov	*4(r1),r0
+	add	$2,4(r1)
+	rts	r5
+
+octal:
+	mov	r4,-(sp)
+	mov	r0,r5
+	mov	$6,-(sp)
+1:
+	clr	r4
+	alsc	$1,r4
+	cmp	(sp),$6
+	beq	2f
+	alsc	$2,r4
+2:
+	add	$'0,r4
+	mov	r4,ch
+	mov	$1,r0
+	sys	write; ch; 1
+	dec	(sp)
+	bne	1b
+	tst	(sp)+
+	mov	(sp)+,r4
+	rts	pc
+
+	.bss
+
+ch:	.=.+2
+f1:	.=.+6; .=.+512.
+f2:	.=.+6; .=.+512.
+*4(r1),r0
+	bic	$!377,r0
+	dec	2(r1)
+	rts	r5
+1:
+	sub	$2,2(r1)
+	bge	1f
+	mov	(r1),r0
+	mov	r1,0f
+	add	$6,0f
+	sys	read; 0:..
\ No newline at end of file