[thirdparty/man-pages.git] / man / man3 / roundup.3

.\" Copyright (C) 2023 Alejandro Colomar <alx@kernel.org>
.\"
.\" SPDX-License-Identifier: Linux-man-pages-copyleft
.\"
.TH roundup 3 (date) "Linux man-pages (unreleased)"
.SH NAME
roundup \- round up in steps
.SH LIBRARY
Standard C library
.RI ( libc )
.SH SYNOPSIS
.nf
.B #include <sys/param.h>
.P
.BI roundup( x ", " step );
.fi
.SH DESCRIPTION
This macro rounds
.I x
to the nearest multiple of
.I step
that is not less than
.IR x .
.P
It is typically used for
rounding up a pointer to align it or
increasing a buffer to be allocated.
.P
This API is not designed to be generic,
and doesn't work in some cases
that are not important for the typical use cases described above.
See CAVEATS.
.SH RETURN VALUE
This macro returns the rounded value.
.SH STANDARDS
None.
.SH CAVEATS
The arguments may be evaluated more than once.
.P
.I x
should be nonnegative,
and
.I step
should be positive.
.P
If
.I x + step
would overflow or wrap around,
the behavior is undefined.
.SH SEE ALSO
.BR ceil (3),
.BR floor (3),
.BR lrint (3),
.BR rint (3),
.BR lround (3),
.BR round (3)
Commit	Line	Data
87a31c30 AC	1	.\" Copyright (C) 2023 Alejandro Colomar <alx@kernel.org>
	2	.\"
	3	.\" SPDX-License-Identifier: Linux-man-pages-copyleft
	4	.\"
	5	.TH roundup 3 (date) "Linux man-pages (unreleased)"
	6	.SH NAME
	7	roundup \- round up in steps
	8	.SH LIBRARY
	9	Standard C library
	10	.RI ( libc )
	11	.SH SYNOPSIS
	12	.nf
	13	.B #include <sys/param.h>
c6d039a3	14	.P
87a31c30 AC	15	.BI roundup( x ", " step );
	16	.fi
	17	.SH DESCRIPTION
	18	This macro rounds
	19	.I x
	20	to the nearest multiple of
	21	.I step
	22	that is not less than
	23	.IR x .
c6d039a3	24	.P
87a31c30 AC	25	It is typically used for
	26	rounding up a pointer to align it or
	27	increasing a buffer to be allocated.
c6d039a3	28	.P
87a31c30 AC	29	This API is not designed to be generic,
	30	and doesn't work in some cases
	31	that are not important for the typical use cases described above.
	32	See CAVEATS.
	33	.SH RETURN VALUE
	34	This macro returns the rounded value.
	35	.SH STANDARDS
4131356c	36	None.
87a31c30 AC	37	.SH CAVEATS
87a31c30 AC	38	The arguments may be evaluated more than once.
c6d039a3	39	.P
87a31c30 AC	40	.I x
	41	should be nonnegative,
	42	and
	43	.I step
	44	should be positive.
c6d039a3	45	.P
87a31c30 AC	46	If
	47	.I x + step
	48	would overflow or wrap around,
	49	the behavior is undefined.
	50	.SH SEE ALSO
	51	.BR ceil (3),
	52	.BR floor (3),
	53	.BR lrint (3),
	54	.BR rint (3),
	55	.BR lround (3),
	56	.BR round (3)