FMA(3)

NAME
fma - multiply and add, then round

SYNOPSIS
#include <math.h>
double
fma(double x, double y, double z);
long double
fmal(long double x, long double y, long double z);
float
fmaf(float x, float y, float z);

DESCRIPTION
The fma() functions compute (x*y)+z, rounded as one ternary operation: they compute the value (as if) to infinite precision and round once to the result format, according to the current rounding mode.

SPECIAL VALUES
fma(x, y, z) returns a NaN and optionally raises the "invalid" floating-point exception if one of x and y is infinite, the other is 0, and z is a NaN.

fma(x, y, z) returns a NaN and raises the "invalid" floating-point exception if one of x and y is infinite, the other is 0, and z is not NaN.

fma(x, y, z) returns a NaN and raises the "invalid" floating-point exception if x times y is an exact infinity, and z is also an infinity but with the opposite sign.

SEE ALSO
fdim(3), fmax(3), fmin(3)

STANDARDS
The fma() functions conform to ISO/IEC 9899:2011.