cc65/libsrc/runtime/lcmp.s

57 lines
1.2 KiB
ArmAsm

;
; Piotr Fusik, 15.04.2002
; originally by Ullrich von Bassewitz
;
; Long int compare function - used by the compare operators
;
.export toslcmp
.import incsp4
.importzp sp, sreg, ptr1
toslcmp:
sta ptr1
stx ptr1+1 ; EAX now in sreg:ptr1
ldy #$03
lda (sp),y
sec
sbc sreg+1
bne L4
dey
lda (sp),y
cmp sreg
bne L1
dey
lda (sp),y
cmp ptr1+1
bne L1
dey
lda (sp),y
cmp ptr1
L1: php ; Save flags
jsr incsp4 ; Drop TOS
plp ; Restore the flags
beq L2
bcs L3
lda #$FF ; Set the N flag
L2: rts
L3: lda #$01 ; Clear the N flag
rts
L4: bvc L5
eor #$FF ; Fix the N flag if overflow
ora #$01 ; Clear the Z flag
L5: php ; Save flags
jsr incsp4 ; Drop TOS
plp ; Restore flags
rts