# floor

FLOOR(3) Linux Programmer's Manual FLOOR(3)
NAME
floor, floorf, floorl - largest integral value not greater than argu-
ment
SYNOPSIS
#include <math.h>
double floor(double x);
float floorf(float x);
long double floorl(long double x);
DESCRIPTION
These functions round x down to the nearest integer.
RETURN VALUE
The rounded integer value. If x is integral or infinite, x itself is
returned.
ERRORS
No errors other than EDOM and ERANGE can occur. If x is NaN, then NaN
is returned and errno may be set to EDOM.
NOTES
SUSv2 and POSIX 1003.1-2001 contain text about overflow (which might
set 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 max-
imum 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).)
CONFORMING TO
The floor() function conforms to SVID 3, POSIX, BSD 4.3, ISO 9899. The
other functions are from C99.
SEE ALSO
ceil(3), lrint(3), nearbyint(3), rint(3), round(3), trunc(3)
2001-05-31 FLOOR(3)