Guardian Native C Library Calls Reference Manual (G06.28+, H06.04+)

Guardian Native C Library Calls (f)
floor(3)
NAME
floor - Rounds floating-point numbers to floating-point integers
LIBRARY
G-series native Guardian processes: $SYSTEM.SYSnn.ZCRESRL
G-series native OSS processes: /G/system/sysnn/zcresrl
H-series native Guardian processes: $SYSTEM.ZDLLnnn.ZCREDLL
H-series OSS processes: /G/system/zdllnnn/zcredll
SYNOPSIS
#include <math.h>
double floor(
double x);
PARAMETERS
x Specifies the double value to be rounded.
DESCRIPTION
The floor() function returns the largest floating-point integer not greater than the x parameter.
NOTES
This function supports both IEEE Std 754-1985 floating-point and Tandem floating-point values
in the native environment. IEEE values can include NaN and infinity, and the sign of 0.0 (zero)
can be either positive or negative. Refer to the fp_class(3) reference page for a description of
IEEE value classes.
Guardian functions are available to convert between floating-point formats. Refer to the Guar-
dian Programmer’s Guide for a discussion of floating-point conversions.
RETURN VALUES
Upon successful completion, the floor() function returns the largest integral value not greater
than x.
For IEEE floating-point values, if the value of x is NaN, NaN is returned. If the value of x is
positive infinity, positive infinity is returned. If the value of x is negative infinity, negative
infinity is returned.
ERRORS
No error values are returned. This function does not set errno.
RELATED INFORMATION
Functions: abs(3), ceil(3), fabs(3), fmod(3), fp_class(3), isnan(3).
STANDARDS CONFORMANCE
For IEEE floating-point data, errno is not set to [EDOM] when the value of x is NaN.
The floor() does not cause overflow, so -HUGE_VAL is not returned and errno is not set to
[ERANGE].
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