| NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | VERSIONS | CONFORMING TO | SEE ALSO | COLOPHON | The Linux Programming Interface |
FMA(3) Linux Programmer's Manual FMA(3)
fma, fmaf, fmal - floating-point multiply and add
#include <math.h>
double fma(double x, double y, double z);
float fmaf(float x, float y, float z);
long double fmal(long double x, long double y, long double z);
Link with -lm.
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
fma(), fmaf(), fmal():
_XOPEN_SOURCE >= 600 || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;
or cc -std=c99
The fma() function computes x * y + z. The result is rounded as one ternary
operation according to the current rounding mode (see fenv(3)).
These functions return the value of x * y + z, rounded as one ternary
operation.
If x or y is a NaN, a NaN is returned.
If x times y is an exact infinity, and z is an infinity with the opposite
sign, a domain error occurs, and a NaN is returned.
If one of x or y is an infinity, the other is 0, and z is not a NaN, a domain
error occurs, and a NaN is returned.
If one of x or y is an infinity, and the other is 0, and z is a NaN, a domain
error occurs, and a NaN is returned.
If x times y is not an infinity times zero (or vice versa), and z is a NaN, a
NaN is returned.
If the result overflows, a range error occurs, and an infinity with the
correct sign is returned.
If the result underflows, a range error occurs, and a signed 0 is returned.
See math_error(7) for information on how to determine whether an error has
occurred when calling these functions.
The following errors can occur:
Domain error: x * y + z, or x * y is invalid and z is not a NaN
An invalid floating-point exception (FE_INVALID) is raised.
Range error: result overflow
An overflow floating-point exception (FE_OVERFLOW) is raised.
Range error: result underflow
An underflow floating-point exception (FE_UNDERFLOW) is raised.
These functions do not set errno.
These functions first appeared in glibc in version 2.1.
C99, POSIX.1-2001.
remainder(3), remquo(3)
This page is part of release 3.32 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can be found
at http://www.kernel.org/doc/man-pages/.
2010-09-20 FMA(3)
HTML rendering created 2010-12-03 by Michael Kerrisk, author of The Linux Programming Interface