1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
|
;
; Ullrich von Bassewitz, 13.08.1998
;
; CC65 runtime: helper stuff for mod/div/mul with long signed ints
;
; When negating values, we will ignore the possibility here, that one of the
; values if $80000000, in which case the negate will fail.
.export poplsargs
.import getlop
.importzp sreg, tmp1, tmp2, ptr1, ptr3, ptr4
poplsargs:
jsr getlop ; Get the operands
; Remember the signs of the operands (that is, the high bytes) in tmp1 and
; tmp2. Make both operands positive.
lda sreg+1 ; Is the left operand negative?
sta tmp1 ; Remember the sign for later
bpl L1 ; Jump if not
clc ; Make it positive
lda ptr1
eor #$FF
adc #$01
sta ptr1
lda ptr1+1
eor #$FF
adc #$00
sta ptr1+1
lda sreg
eor #$FF
adc #$00
sta sreg
lda sreg+1
eor #$FF
adc #$00
sta sreg+1
L1: lda ptr4+1 ; Is the right operand nagative?
sta tmp2 ; Remember the sign for later
bpl L2 ; Jump if not
clc ; Make it positive
lda ptr3
eor #$FF
adc #$01
sta ptr3
lda ptr3+1
eor #$FF
adc #$00
sta ptr3+1
lda ptr4
eor #$FF
adc #$00
sta ptr4
lda ptr4+1
eor #$FF
adc #$00
sta ptr4+1
L2: rts
|
