ack/mach/m68k4/libem/cmu.s

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ArmAsm
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.define .cmu
.sect .text
.sect .rom
.sect .data
.sect .bss
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.sect .text
! on entry d0: # bytes of 1 block
! on exit d0: result
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.cmu:
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move.l (sp)+, d2 ! return address
move.l sp, a0 ! address of top block
lea 0(sp, d0.l), a1 ! address of lower block
move.l d0, d1
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
bne 1b ! note: on equal carry is set
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2:
bcc 3f
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neg.l d0 ! less
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3:
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asl.l #1, d1
add.l d1, sp ! new sp; two blocks popped
move.l d2, -(sp)
rts
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.align 2