\left(\frac{1}{\sqrt{\pi}} \cdot e^{\left|x\right| \cdot \left|x\right|}\right) \cdot \left(\left(\left(\frac{1}{\left|x\right|} + \frac{1}{2} \cdot \left(\left(\frac{1}{\left|x\right|} \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right)\right) + \frac{3}{4} \cdot \left(\left(\left(\left(\frac{1}{\left|x\right|} \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right)\right) + \frac{15}{8} \cdot \left(\left(\left(\left(\left(\left(\frac{1}{\left|x\right|} \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right)\right)\left(\frac{1}{\sqrt{\pi}} \cdot {\left(e^{\left|x\right|}\right)}^{\left(\left|x\right|\right)}\right) \cdot \left(\left(\left(\frac{1}{\left|x\right|} + \frac{1}{2} \cdot \left(\frac{1}{\left|x\right|} \cdot \left(\frac{1}{\left|x\right|} \cdot \frac{1}{\left|x\right|}\right)\right)\right) + \frac{3}{4} \cdot \left(\frac{1}{\left|x\right|} \cdot \left(\frac{1}{\left|x\right|} \cdot \left(\frac{1}{\left|x\right|} \cdot \frac{1}{{\left(\left|x\right|\right)}^{2}}\right)\right)\right)\right) + \frac{15}{8} \cdot \left(\frac{1}{\left|x\right|} \cdot \left(\frac{1}{\left|x\right|} \cdot \left(\frac{1}{\left|x\right|} \cdot \left(\frac{1}{\left|x\right|} \cdot \left(\frac{1}{\left|x\right|} \cdot \left(\frac{\sqrt{1}}{\sqrt{\left|x\right|}} \cdot {\left({\left(\frac{\sqrt{1}}{\sqrt{\left|x\right|}}\right)}^{\left(\sqrt[3]{3} \cdot \sqrt[3]{3}\right)}\right)}^{\left(\sqrt[3]{3}\right)}\right)\right)\right)\right)\right)\right)\right)(FPCore (x)
:precision binary64
(*
(* (/ 1.0 (sqrt PI)) (exp (* (fabs x) (fabs x))))
(+
(+
(+
(/ 1.0 (fabs x))
(*
(/ 1.0 2.0)
(* (* (/ 1.0 (fabs x)) (/ 1.0 (fabs x))) (/ 1.0 (fabs x)))))
(*
(/ 3.0 4.0)
(*
(*
(* (* (/ 1.0 (fabs x)) (/ 1.0 (fabs x))) (/ 1.0 (fabs x)))
(/ 1.0 (fabs x)))
(/ 1.0 (fabs x)))))
(*
(/ 15.0 8.0)
(*
(*
(*
(*
(* (* (/ 1.0 (fabs x)) (/ 1.0 (fabs x))) (/ 1.0 (fabs x)))
(/ 1.0 (fabs x)))
(/ 1.0 (fabs x)))
(/ 1.0 (fabs x)))
(/ 1.0 (fabs x)))))))(FPCore (x)
:precision binary64
(*
(* (/ 1.0 (sqrt PI)) (pow (exp (fabs x)) (fabs x)))
(+
(+
(+
(/ 1.0 (fabs x))
(*
(/ 1.0 2.0)
(* (/ 1.0 (fabs x)) (* (/ 1.0 (fabs x)) (/ 1.0 (fabs x))))))
(*
(/ 3.0 4.0)
(*
(/ 1.0 (fabs x))
(* (/ 1.0 (fabs x)) (* (/ 1.0 (fabs x)) (/ 1.0 (pow (fabs x) 2.0)))))))
(*
(/ 15.0 8.0)
(*
(/ 1.0 (fabs x))
(*
(/ 1.0 (fabs x))
(*
(/ 1.0 (fabs x))
(*
(/ 1.0 (fabs x))
(*
(/ 1.0 (fabs x))
(*
(/ (sqrt 1.0) (sqrt (fabs x)))
(pow
(pow (/ (sqrt 1.0) (sqrt (fabs x))) (* (cbrt 3.0) (cbrt 3.0)))
(cbrt 3.0))))))))))))double code(double x) {
return ((double) (((double) ((1.0 / ((double) sqrt(((double) M_PI)))) * ((double) exp(((double) (((double) fabs(x)) * ((double) fabs(x)))))))) * ((double) (((double) (((double) ((1.0 / ((double) fabs(x))) + ((double) ((1.0 / 2.0) * ((double) (((double) ((1.0 / ((double) fabs(x))) * (1.0 / ((double) fabs(x))))) * (1.0 / ((double) fabs(x))))))))) + ((double) ((3.0 / 4.0) * ((double) (((double) (((double) (((double) ((1.0 / ((double) fabs(x))) * (1.0 / ((double) fabs(x))))) * (1.0 / ((double) fabs(x))))) * (1.0 / ((double) fabs(x))))) * (1.0 / ((double) fabs(x))))))))) + ((double) ((15.0 / 8.0) * ((double) (((double) (((double) (((double) (((double) (((double) ((1.0 / ((double) fabs(x))) * (1.0 / ((double) fabs(x))))) * (1.0 / ((double) fabs(x))))) * (1.0 / ((double) fabs(x))))) * (1.0 / ((double) fabs(x))))) * (1.0 / ((double) fabs(x))))) * (1.0 / ((double) fabs(x)))))))))));
}
double code(double x) {
return ((double) (((double) ((1.0 / ((double) sqrt(((double) M_PI)))) * ((double) pow(((double) exp(((double) fabs(x)))), ((double) fabs(x)))))) * ((double) (((double) (((double) ((1.0 / ((double) fabs(x))) + ((double) ((1.0 / 2.0) * ((double) ((1.0 / ((double) fabs(x))) * ((double) ((1.0 / ((double) fabs(x))) * (1.0 / ((double) fabs(x))))))))))) + ((double) ((3.0 / 4.0) * ((double) ((1.0 / ((double) fabs(x))) * ((double) ((1.0 / ((double) fabs(x))) * ((double) ((1.0 / ((double) fabs(x))) * (1.0 / ((double) pow(((double) fabs(x)), 2.0))))))))))))) + ((double) ((15.0 / 8.0) * ((double) ((1.0 / ((double) fabs(x))) * ((double) ((1.0 / ((double) fabs(x))) * ((double) ((1.0 / ((double) fabs(x))) * ((double) ((1.0 / ((double) fabs(x))) * ((double) ((1.0 / ((double) fabs(x))) * ((double) ((((double) sqrt(1.0)) / ((double) sqrt(((double) fabs(x))))) * ((double) pow(((double) pow((((double) sqrt(1.0)) / ((double) sqrt(((double) fabs(x))))), ((double) (((double) cbrt(3.0)) * ((double) cbrt(3.0)))))), ((double) cbrt(3.0))))))))))))))))))))));
}



Bits error versus x
Results
Initial program 2.8
rmApplied add-log-exp_binary642.8
Applied exp-to-pow_binary641.4
rmApplied add-sqr-sqrt_binary641.4
Applied add-sqr-sqrt_binary641.4
Applied times-frac_binary641.4
Applied associate-*r*_binary641.4
Simplified1.4
Taylor expanded around 0 1.4
rmApplied add-cube-cbrt_binary641.4
Applied pow-unpow_binary641.4
Final simplification1.4
herbie shell --seed 2020210
(FPCore (x)
:name "Jmat.Real.erfi, branch x greater than or equal to 5"
:precision binary64
:pre (>= x 0.5)
(* (* (/ 1.0 (sqrt PI)) (exp (* (fabs x) (fabs x)))) (+ (+ (+ (/ 1.0 (fabs x)) (* (/ 1.0 2.0) (* (* (/ 1.0 (fabs x)) (/ 1.0 (fabs x))) (/ 1.0 (fabs x))))) (* (/ 3.0 4.0) (* (* (* (* (/ 1.0 (fabs x)) (/ 1.0 (fabs x))) (/ 1.0 (fabs x))) (/ 1.0 (fabs x))) (/ 1.0 (fabs x))))) (* (/ 15.0 8.0) (* (* (* (* (* (* (/ 1.0 (fabs x)) (/ 1.0 (fabs x))) (/ 1.0 (fabs x))) (/ 1.0 (fabs x))) (/ 1.0 (fabs x))) (/ 1.0 (fabs x))) (/ 1.0 (fabs x)))))))