std::fma

From cppreference.com
 
 
 
Common mathematical functions
Functions
Basic operations
remainder (C++11)
remquo (C++11)
fma (C++11)
fmax (C++11)
fmin (C++11)
fdim (C++11)
nan
nanf
nanl
(C++11)
(C++11)
(C++11)
Exponential functions
exp
exp2 (C++11)
expm1 (C++11)
log
log10
log1p (C++11)
log2 (C++11)
Power functions
sqrt
cbrt (C++11)
hypot (C++11)
pow
Trigonometric and hyperbolic functions
sinh
cosh
tanh
asinh (C++11)
acosh (C++11)
atanh (C++11)
Error and gamma functions
erf (C++11)
erfc (C++11)
lgamma (C++11)
tgamma (C++11)
Nearest integer floating point operations
ceil
floor
round
lround
llround
(C++11)
(C++11)
(C++11)
trunc (C++11)
nearbyint (C++11)
rint
lrint
llrint
(C++11)
(C++11)
(C++11)
Floating point manipulation functions
ldexp
scalbn
scalbln
(C++11)
(C++11)
ilogb (C++11)
logb (C++11)
frexp
modf
nextafter
nexttoward
(C++11)
(C++11)
copysign (C++11)
Classification/Comparison
fpclassify (C++11)
isfinite (C++11)
isinf (C++11)
isnan (C++11)
isnormal (C++11)
signbit (C++11)
isgreater (C++11)
isgreaterequal (C++11)
isless (C++11)
islessequal (C++11)
islessgreater (C++11)
isunordered (C++11)
Macro constants
FP_NORMAL
FP_SUBNORMAL
FP_ZERO
FP_INFINITE
FP_NAN
(C++11)
(C++11)
(C++11)
(C++11)
(C++11)
 
Defined in header <cmath>
float       fma( float x, float y, float z );
(1) (since C++11)
double      fma( double x, double y, double z );
(2) (since C++11)
long double fma( long double x, long double y, long double z );
(3) (since C++11)
Promoted    fma( Arithmetic x, Arithmetic y, Arithmetic z );
(4) (since C++11)
#define FP_FAST_FMA  /* implementation-defined */
(5) (since C++11)
#define FP_FAST_FMAF /* implementation-defined */
(6) (since C++11)
#define FP_FAST_FMAL /* implementation-defined */
(7) (since C++11)

The fma functions compute (x*y) + z, rounded as one ternary operation, according to the rounding mode characterized by the value of FLT_ROUNDS.

4) If any argument has integral type, it is cast to double. If any other argument is long double, then the return type is long double, otherwise it is double.

5-7) If the macro constants FP_FAST_FMAF, FP_FAST_FMA, or FP_FAST_FMAL are defined, the function std::fma evaluates faster than the expression x*y+z for float, double, and long double arguments, respectively. If defined, these macros evaluate to integer 1.

[edit] Parameters

x, y, z - floating point values

[edit] Return value

(x*y) + z, rounded as one ternary operation

[edit] See also

(C++11)
signed remainder of the division operation
(function)
(C++11)
signed remainder as well as the three last bits of the division operation
(function)