mirror of
https://github.com/cc65/cc65.git
synced 2024-12-23 19:29:37 +00:00
45 lines
677 B
ArmAsm
45 lines
677 B
ArmAsm
;
|
|
; Piotr Fusik, 15.04.2002
|
|
; originally by Ullrich von Bassewitz
|
|
;
|
|
; Integer compare function - used by the compare operators
|
|
;
|
|
|
|
.export tosicmp
|
|
.importzp sp, sreg
|
|
|
|
|
|
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
|
|
|
|
|