ORDERED_MASK_COMPARE(3)

NAME

     ordered_mask_compare -- successive comparisons of a pair  of
     words against a series of masks

SYNOPSIS

     #include <soi_fun.h>

     extern int ordered_mask_compare (unsigned int a, unsigned int b,
         int nmasks, ...)

DESCRIPTION

     This function successively masks each of the pair of words a
     and b against a series of nmasks masks.  On encountering the
     first case in which the masked values differ,  the  function
     returns  -1 if the masked value of a is less than that of b,
     1 otherwise.  If all requested comparisons  are  equal,  the
     function returns 0.

     The masked values are compared arithmetically, so  multi-bit
     masks may be used.

EXAMPLES

     #define FRACTION_MISSING (31 << 27)
     #define REALLY_CRUMBY     (1)
     ordered_mask_compare (unsigned int a, unsigned int b, 2,
       REALLY_CRUMBY, FRACTION_MISSING)
     will return the number (-1 or 1) of whichever one of the two
     test  values  has  the  low-order bit clear; if both have it
     clear or set, it will return the number of whichever  has  a
     lower  numeric value in bits 27-31.  If bits 0 and 27-31 are
     identical in the test values, the function returns 0.

FILES

SEE ALSO

DIAGNOSTICS

BUGS

     The comparison words and masks are assumed to be  of  length
     sizeof (int).

AUTHOR

     Rick Bogart

HISTORY

     1998-03-25      SOI Version 2.10