27 lines
502 B
ArmAsm
27 lines
502 B
ArmAsm
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; Ullrich von Bassewitz, 08.10.1998
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; CC65 runtime: -= operator for ints on the stack
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.export subeq0sp, subeqysp
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.importzp spc
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subeq0sp:
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ldy #0
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subeqysp:
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sec
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eor #$FF
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adc (spc),y
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sta (spc),y
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pha ; Save low byte
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iny
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txa
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eor #$FF
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adc (spc),y
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sta (spc),y
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tax
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pla ; Restore low byte
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rts
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