V6/usr/source/s5/printf.s
/ C library -- printf
.globl _printf
.globl pfloat
.globl pscien
.globl _putchar
.globl csv
.globl cret
_printf:
jsr r5,csv
sub $126.,sp
mov 4(r5),formp / format
mov r5,r4
add $6,r4 / arglist
loop:
movb *formp,r0
beq 1f
inc formp
cmp r0,$'%
beq 2f
3:
mov r0,(sp)
jsr pc,*$_putchar
br loop
1:
jmp cret
2:
clr rjust
clr ndigit
cmpb *formp,$'-
bne 2f
inc formp
inc rjust
2:
jsr r3,gnum
mov r1,width
clr ndfnd
cmp r0,$'.
bne 1f
jsr r3,gnum
mov r1,ndigit
1:
mov sp,r3
add $4,r3
mov $swtab,r1
1:
mov (r1)+,r2
beq 3b
cmp r0,(r1)+
bne 1b
jmp (r2)
.data
swtab:
decimal; 'd
octal; 'o
hex; 'x
float; 'f
scien; 'e
charac; 'c
string; 's
logical; 'l
remote; 'r
0; 0
.text
decimal:
mov (r4)+,r1
bge 1f
neg r1
movb $'-,(r3)+
br 1f
logical:
mov (r4)+,r1
1:
jsr pc,1f
br prbuf
1:
clr r0
div $10.,r0
mov r1,-(sp)
mov r0,r1
beq 1f
jsr pc,1b
1:
mov (sp)+,r0
add $'0,r0
movb r0,(r3)+
rts pc
charac:
movb (r4)+,(r3)+
bne 1f
dec r3
1:
movb (r4)+,(r3)+
bne prbuf
dec r3
br prbuf
string:
mov ndigit,r1
clr r3
mov (r4),r2
1:
tstb (r2)+
beq 1f
inc r3
sob r1,1b
1:
mov (r4)+,r2
br prstr
hex:
mov $1f,r2
.data
1:
-4; !17
.text
br 2f
octal:
mov $1f,r2
.data
1:
-3; !7
.text
2:
mov (r4)+,r1
beq 2f
tst ndigit
beq 2f
movb $'0,(r3)+
2:
clr r0
jsr pc,1f
br prbuf
1:
mov r1,-(sp)
ashc (r2),r0
beq 1f
jsr pc,1b
1:
mov (sp)+,r0
bic 2(r2),r0
add $'0,r0
cmp r0,$'9
ble 1f
add $'A-'0-10.,r0
1:
movb r0,(r3)+
rts pc
float:
mov ndigit,r0
mov ndfnd,r2
jsr pc,pfloat
br prbuf
scien:
mov ndigit,r0
mov ndfnd,r2
jsr pc,pscien
br prbuf
remote:
mov (r4)+,r4
mov (r4)+,formp
jmp loop
prbuf:
mov sp,r2
add $4,r2
sub r2,r3
prstr:
mov r4,-(sp)
mov $' ,-(sp)
mov r3,r4
neg r3
add width,r3
ble 1f
tst rjust
bne 1f
2:
jsr pc,*$_putchar
sob r3,2b
1:
tst r4
beq 2f
1:
movb (r2)+,(sp)
jsr pc,*$_putchar
sob r4,1b
2:
tst r3
ble 1f
mov $' ,(sp)
2:
jsr pc,*$_putchar
sob r3,2b
1:
tst (sp)+
mov (sp)+,r4
jmp loop
gnum:
clr ndfnd
clr r1
1:
movb *formp,r0
inc formp
sub $'0,r0
cmp r0,$'*-'0
bne 2f
mov (r4)+,r0
br 3f
2:
cmp r0,$9.
bhi 1f
3:
inc ndfnd
mul $10.,r1
add r0,r1
br 1b
1:
add $'0,r0
rts r3
.bss
width: .=.+2
formp: .=.+2
rjust: .=.+2
ndfnd: .=.+2
ndigit: .=.+2