43 lines
801 B
ArmAsm
43 lines
801 B
ArmAsm
.define Cmi4
|
|
.sect .text
|
|
.sect .rom
|
|
.sect .data
|
|
.sect .bss
|
|
.sect .text
|
|
|
|
! This subroutine compares on fourbyte integers.
|
|
! If T is pushed first and than S, the routine will return:
|
|
! -1 if S < T,
|
|
! 0 if S = T,
|
|
! 1 if S > T.
|
|
|
|
|
|
Cmi4:
|
|
jsr Sbi4 ! subtract operands (T - S)
|
|
jsr Pop ! get result (lowbyte, lowbyte+1)
|
|
stx ARTH ! store lowbyte
|
|
sta ARTH+1 ! store lowbyte+1
|
|
jsr Pop ! get result (lowbyte+2, lowbyte+3)
|
|
tay ! test lowbyte+3
|
|
bpl 1f ! S >= T
|
|
lda #0FFh ! S < T
|
|
tax ! AX becomes -1
|
|
rts
|
|
1: cmp #0 ! test lowbyte+3 on zero
|
|
bne 2f
|
|
cpx #0 ! test lowbyte+2 on zero
|
|
bne 2f
|
|
lda #0
|
|
cmp ARTH+1 ! test lowbyte+1 on zero
|
|
bne 2f
|
|
cmp ARTH ! test lowbyte on zero
|
|
bne 2f
|
|
lda #0 ! S = T
|
|
tax ! AX becomes 0
|
|
rts
|
|
2: lda #0 ! S > T
|
|
ldx #1 ! AX becomes 1
|
|
rts
|
|
|
|
|