\left(0.5 \cdot \cos re\right) \cdot \left(e^{-im} + e^{im}\right)\mathsf{fma}\left(0.5, e^{im}, \frac{0.5}{e^{im}}\right) \cdot \cos redouble code(double re, double im) {
return ((0.5 * cos(re)) * (exp(-im) + exp(im)));
}
double code(double re, double im) {
return (fma(0.5, exp(im), (0.5 / exp(im))) * cos(re));
}



Bits error versus re



Bits error versus im
Results
Initial program 0.0
Simplified0.0
Final simplification0.0
herbie shell --seed 2020105 +o rules:numerics
(FPCore (re im)
:name "math.cos on complex, real part"
:precision binary64
(* (* 0.5 (cos re)) (+ (exp (- im)) (exp im))))