V3/usr/man/man3/compar.3

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NAME		compar -- default comparison routine for qsort
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SYNOPSIS	jsr pc,compar
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DESCRIPTION	Compar is the default comparison routine
called by qsort and is separated out so that the user can
supply his own comparison.
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The routine is called with the width (in bytes) of
an element in r3 and it compares byte-by-byte the element
pointed to by r0 with the element pointed to by r4.
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Return is via the condition codes,
which are tested by the instructions "blt" and "bgt".
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That is, in the absence of overflow, then the 
condition (r0) < (r4) should leave the Z-bit off and N-bit
on while (r0) > (r4) should leave Z and N off.
Still another way of putting it is that  for elements
of length 1 the instruction

	cmpb	(r0),(r4)

suffices.
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Only r0 is changed by the call.
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FILES		kept in /lib/liba.a
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SEE ALSO	qsort (III)
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DIAGNOSTICS	--
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BUGS		It could be recoded to run faster.