ack/mach/6500/libem/tgt.s
1987-01-30 18:41:42 +00:00

27 lines
353 B
ArmAsm

.define Tgt
.sect .text
.sect .rom
.sect .data
.sect .bss
.sect .text
! This subroutine tests if the value in registerpair AX is
! greater than zero.
! The value returned is in AX.
Tgt:
tay
bpl 1f ! A >= 0
3: lda #0 ! AX <= 0
tax
rts
1: beq 1f ! A = 0
2: lda #0 ! AX > 0
ldx #1
rts
1: txa
bne 2b ! X > 0
beq 3b ! X = 0