25 lines
344 B
ArmAsm
25 lines
344 B
ArmAsm
.define Ngi2
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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 negates the integer in registerpair AX.
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! The negation is a one's complement plus one.
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Ngi2:
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eor #0FFh ! one's complement A
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tay
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txa
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eor #0FFh ! one's complement X
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tax
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inx ! increment X
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bne 1f
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iny ! increment A if neccesairy
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1: tya
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rts
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