30 lines
500 B
ArmAsm
30 lines
500 B
ArmAsm
.define .cmu
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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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! on entry d0: # bytes in 1 block
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! on exit d0: result
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.cmu:
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move.l (sp)+, d1 ! return address
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move.l sp, a0 ! address of top block
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lea (sp,d0.l), a1 ! address of lower block
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move.l d1,-(sp)
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move.l d0, d1
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asr.l #2, d0
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1:
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cmp.l (a0)+, (a1)+
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bne 2f
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sub.l #1, d0
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bne 1b ! note: on equal carry is set
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2:
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bcc 3f
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neg.l d0 ! less
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3:
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move.l (sp)+,a0
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lea (sp,d1.l*2), sp ! new sp; two blocks popped
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jmp (a0)
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.align 2
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