From ce3e0cefcc25b69e67e05793b9902ebfdb654bfd Mon Sep 17 00:00:00 2001
From: Robert Morris <rhm@research.uucp>
Date: Tue, 26 Nov 1974 18:13:21 -0500
Subject: [PATCH] Research V5 development Work on file usr/source/s1/form2.s

Co-Authored-By: Ken Thompson <ken@research.uucp>
Synthesized-from: v5
---
 usr/source/s1/form2.s | 92 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)
 create mode 100644 usr/source/s1/form2.s

diff --git a/usr/source/s1/form2.s b/usr/source/s1/form2.s
new file mode 100644
index 0000000000..d9c9674237
--- /dev/null
+++ b/usr/source/s1/form2.s
@@ -0,0 +1,92 @@
+/	scan
+/	r1 = pointer to input header
+/	r0 = pointer to output header
+/	switch = 0 real output
+/		not 0  output to r0
+scan:
+	mov	r0,-(sp)
+	mov	r1,-(sp)
+
+1:
+	mov	(sp),r1
+	jsr	pc,getchar
+	bes	5f
+	cmpb	r0,$'\\
+	beq	3f
+	cmpb	r0,$'\[
+	beq	4f
+	cmpb	r0,$'\{
+	beq	4f
+	cmpb	r0,$'\]
+	beq	1f
+	cmpb	r0,$'\}
+	beq	7f
+	cmpb	r0,$'\n
+	bne	6f
+	jsr	pc,lookchar
+	bes	5f
+	movb	$'\n,r0
+6:
+	tst	switch
+	beq	2f
+	mov	2(sp),r1
+	jsr	pc,putchar
+	br	1b
+2:
+	jsr	r5,putc
+	br	1b
+3:
+	jsr	pc,getchar
+	br	6b
+/	have [ or {
+4:
+	mov	r(r1),-(sp)
+	jsr	pc,getchar
+	bes	1f
+	cmpb	r0,$'0
+	blt	4f
+	cmpb	r0,$'9
+	bgt	4f
+	jsr	pc,getchar
+	cmpb	r0,$'\]
+	beq	3f
+	cmpb	r0,$'\}
+	beq	3f
+
+4:
+	mov	(sp)+,r(r1)
+	mov	2(sp),r0
+	jsr	pc,esub
+	mov	r1,(sp)
+	mov	r0,2(sp)
+	br	1b
+
+/	have arg
+3:
+	tst	switch
+	beq	2f
+	mov	opointer,r1
+	mov	4(sp),r0
+	jsr	pc,putword
+	mov	2(sp),r1
+2:
+	mov	(sp)+,r(r1)
+	jsr	pc,getchar
+	inc	r(r1)	/skip ]
+	jsr	pc,earg
+	br	1b
+
+5:
+	tst	argf
+	bne	1f
+	mov	ipointer,r1
+	jsr	pc,pop
+	bes	1f
+	mov	r0,(sp)
+	br	1b
+7:
+	inc	curlyf
+1:
+	mov	(sp)+,r1
+	mov	(sp)+,r0
+	rts	pc
-- 
2.20.1