26 lines
335 B
ArmAsm
26 lines
335 B
ArmAsm
.define Teq
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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 test if the value in registerpair AX is zero
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! or nonzero.
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! The returned value, a 1 or a 0, is in AX.
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Teq:
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tay
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beq 1f ! A is zero
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2: lda #0 ! AX is zero
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tax
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rts
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1: txa
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bne 2b ! X is zero
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lda #0 ! AX is nonzero
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ldx #1
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rts
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