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);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
These functions compute
z. The result is rounded as one ternary operation according to the current rounding mode (see fenv(3)).
These functions return the value of
z, rounded as one ternary operation.
y is a NaN, a NaN is returned.
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
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
y is an infinity, and the other is 0, and
z is a NaN, a domain error occurs, and a NaN is returned.
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:
yis invalid and
zis not a NaN
An 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
These functions first appeared in glibc in version 2.1.
C99, POSIX.1-2001, POSIX.1-2008.
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