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37 lines
464 B
ArmAsm
37 lines
464 B
ArmAsm
12 years ago
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; Ullrich von Bassewitz, 08.10.1998
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; CC65 runtime: -= operator for longs on the stack
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;
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.export lsubeq0sp, lsubeqysp
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.importzp sp, sreg
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lsubeq0sp:
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ldy #0
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lsubeqysp:
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sec
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eor #$FF
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adc (sp),y
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sta (sp),y
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pha ; Save low byte
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iny
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txa
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eor #$FF
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adc (sp),y
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sta (sp),y
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tax
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iny
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lda (sp),y
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sbc sreg
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sta (sp),y
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sta sreg
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iny
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lda (sp),y
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sbc sreg+1
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sta (sp),y
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sta sreg+1
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pla
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rts
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