35 lines
531 B
ArmAsm
35 lines
531 B
ArmAsm
.define Cmu2
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.sect .text
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.sect .rom
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.sect .data
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.sect .bss
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.sect .text
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! This subroutine compares two unsigned twobyte integers.
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! If T is the first pushed and than S, the routine will return:
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! -1 if S < T,
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! 0 if S = T,
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! 1 if S > T.
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Cmu2:
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stx EXG ! S (lowbyte)
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sta EXG+1 ! S (highbyte)
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jsr Pop ! get T
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cmp EXG+1
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beq 2f ! S (highbyte) = T (highbyte)
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bcc 1f
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4: lda #0 ! S > T
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ldx #1
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rts
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1: lda #0xFF ! S < T
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tax
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rts
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2: cpx EXG
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bne 3f
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lda #0 ! S = T
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tax
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rts
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3: bcc 1b
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bcs 4b
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