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ROUNDUP(9)		   Kernel Developer's Manual		    ROUNDUP(9)

NAME
       roundup -- macros for counting and rounding

SYNOPSIS
       #include	<sys/param.h>

       size
       howmany(x, size);

       size
       roundup(x, size);

       size
       rounddown(x, size);

       size
       roundup2(x, size);

       int
       powerof2(x);

DESCRIPTION
       The  roundup() and rounddown() macros return an integer from rounding x
       up and down, respectively, to the next size.  The  howmany()  macro  in
       turn reveals how	many times size	fits into x, rounding the residual up.

       The  roundup2() macro also rounds up, but with the assumption that size
       is a power of two.  If x	is indeed a power of two, powerof2() return 1.

RETURN VALUES
       The return value	is an integer from the respective operation.  If x  is
       0, all macros except powerof2() return 0.  The behavior is undefined if
       size is 0.

EXAMPLES
       The following example rounds the	variable rx to a 32-bit	boundary:

	     uint16_t rx;

	     ...

	     rx	= roundup2(rx, sizeof(uint32_t));

SEE ALSO
       ilog2(3), param(3), imax(9)

CAVEATS
       All  described macros make no assumptions about the type	of the parame-
       ters.  These are	implicitly assumed to be unsigned integers.

NetBSD 8.0			 June 1, 2011			    ROUNDUP(9)

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<https://man.freebsd.org/cgi/man.cgi?query=roundup&sektion=9&manpath=NetBSD+8.0>

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