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
|
;
; Piotr Fusik, 15.04.2002
; originally by Ullrich von Bassewitz
;
; Integer compare function - used by the compare operators
;
.export tosicmp, tosicmp0
.importzp sp, sreg
tosicmp0:
ldx #$00
tosicmp:
sta sreg
stx sreg+1 ; Save ax
ldy #$00
lda (sp),y ; Get low byte
tax
inc sp ; 5
bne @L1 ; 3
inc sp+1 ; (5)
@L1:
lda (sp),y ; Get high byte
inc sp ; 5
bne @L2 ; 3
inc sp+1 ; (5)
; Do the compare.
@L2: sec
sbc sreg+1 ; Compare high byte
bne @L4
cpx sreg ; Compare low byte
beq @L3
adc #$FF ; If the C flag is set then clear the N flag
ora #$01 ; else set the N flag
@L3: rts
@L4: bvc @L3
eor #$FF ; Fix the N flag if overflow
ora #$01 ; Clear the Z flag
rts
|
