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diff --git a/man3/round.3 b/man3/round.3 new file mode 100644 index 000000000..6b376094f --- /dev/null +++ b/man3/round.3 @@ -0,0 +1,69 @@ +.\" Copyright 2001 Andries Brouwer <aeb@cwi.nl>. +.\" +.\" Permission is granted to make and distribute verbatim copies of this +.\" manual provided the copyright notice and this permission notice are +.\" preserved on all copies. +.\" +.\" Permission is granted to copy and distribute modified versions of this +.\" manual under the conditions for verbatim copying, provided that the +.\" entire resulting derived work is distributed under the terms of a +.\" permission notice identical to this one. +.\" +.\" Since the Linux kernel and libraries are constantly changing, this +.\" manual page may be incorrect or out-of-date. The author(s) assume no +.\" responsibility for errors or omissions, or for damages resulting from +.\" the use of the information contained herein. The author(s) may not +.\" have taken the same level of care in the production of this manual, +.\" which is licensed free of charge, as they might when working +.\" professionally. +.\" +.\" Formatted or processed versions of this manual, if unaccompanied by +.\" the source, must acknowledge the copyright and authors of this work. +.\" +.TH ROUND 3 2001-05-31 "" "Linux Programmer's Manual" +.SH NAME +round, roundf, roundl \- round to nearest integer, away from zero +.SH SYNOPSIS +.nf +.B #include <math.h> +.sp +.BI "double round(double " x ); +.br +.BI "float roundf(float " x ); +.br +.BI "long double roundl(long double " x ); +.fi +.sp +Link with \-lm. +.SH DESCRIPTION +These functions round \fIx\fP to the nearest integer, but +round halfway cases away from zero (regardless of the current rounding +direction), instead of to the nearest even integer like rint(). +.SH "RETURN VALUE" +The rounded integer value. If \fIx\fP is integral or infinite, +\fIx\fP itself is returned. +.SH ERRORS +No errors other than EDOM and ERANGE can occur. +If \fIx\fP is NaN, then NaN is returned and +.I errno +may be set to EDOM. +.SH NOTES +POSIX 1003.1-2001 contains text about overflow (which might set +.I errno +to ERANGE, or raise an exception). +In practice, the result cannot overflow on any current machine, +so this error-handling stuff is just nonsense. +(More precisely, overflow can happen only when the maximum value +of the exponent is smaller than the number of mantissa bits. +For the IEEE-754 standard 32-bit and 64-bit floating point numbers +the maximum value of the exponent is 128 (resp. 1024), and the number +of mantissa bits is 24 (resp. 53).) +.SH "CONFORMING TO" +C99. +.SH "SEE ALSO" +.BR ceil (3), +.BR floor (3), +.BR lround (3), +.BR nearbyint (3), +.BR rint (3), +.BR trunc (3) |