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); |
![]() |
Note | |||
|---|---|---|---|---|
|
![]() |
Note |
|---|---|
|
Link with |
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:
x * y + z, or x * y is invalid and z is not a NaNAn invalid floating-point exception (FE_INVALID) is raised.
An overflow floating-point exception (FE_OVERFLOW) is raised.
An underflow floating-point exception (FE_UNDERFLOW) is raised.
These functions do not set errno.
This page is part of release 3.33 of the Linux man-pages project. A
description of the project, and information about reporting
bugs, can be found at http://man7.org/linux/man-pages/.
|
Copyright 2002 Walter Harms (walter.harmsinformatik.uni-oldenburg.de) and Copyright 2008, Linux Foundation, written by Michael Kerrisk <mtk.manpagesgmail.com> Distributed under GPL, 2002-07-27 Walter Harms Modified 2004-11-15, Added further text on FLT_ROUNDS as suggested by AEB and Fabian Kreutz |