1 - \left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-0.284496736 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(1.421413741 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-1.453152027 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}\sqrt[3]{1 - \frac{\sqrt[3]{{\left(0.254829592 + \frac{-0.284496736 + \frac{1.421413741 + \frac{\frac{1.061405429}{1 + 0.3275911 \cdot \left|x\right|} + -1.453152027}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}\right)}^{3}}}{\left(1 + 0.3275911 \cdot \left|x\right|\right) \cdot e^{x \cdot x}}} \cdot \left(\sqrt[3]{1 - \frac{\sqrt[3]{{\left(0.254829592 + \frac{-0.284496736 + \frac{1.421413741 + \frac{\frac{1.061405429}{1 + 0.3275911 \cdot \left|x\right|} + -1.453152027}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}\right)}^{3}}}{\left(1 + 0.3275911 \cdot \left|x\right|\right) \cdot e^{x \cdot x}}} \cdot \sqrt[3]{1 - \frac{\sqrt[3]{{\left(0.254829592 + \frac{-0.284496736 + \frac{1.421413741 + \frac{\frac{1.061405429}{1 + 0.3275911 \cdot \left|x\right|} + -1.453152027}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}\right)}^{3}}}{\left(1 + 0.3275911 \cdot \left|x\right|\right) \cdot e^{x \cdot x}}}\right)(FPCore (x)
:precision binary64
(-
1.0
(*
(*
(/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
(+
0.254829592
(*
(/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
(+
-0.284496736
(*
(/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
(+
1.421413741
(*
(/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
(+
-1.453152027
(* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) 1.061405429)))))))))
(exp (- (* (fabs x) (fabs x)))))))(FPCore (x)
:precision binary64
(*
(cbrt
(-
1.0
(/
(cbrt
(pow
(+
0.254829592
(/
(+
-0.284496736
(/
(+
1.421413741
(/
(+ (/ 1.061405429 (+ 1.0 (* 0.3275911 (fabs x)))) -1.453152027)
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
3.0))
(* (+ 1.0 (* 0.3275911 (fabs x))) (exp (* x x))))))
(*
(cbrt
(-
1.0
(/
(cbrt
(pow
(+
0.254829592
(/
(+
-0.284496736
(/
(+
1.421413741
(/
(+ (/ 1.061405429 (+ 1.0 (* 0.3275911 (fabs x)))) -1.453152027)
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
3.0))
(* (+ 1.0 (* 0.3275911 (fabs x))) (exp (* x x))))))
(cbrt
(-
1.0
(/
(cbrt
(pow
(+
0.254829592
(/
(+
-0.284496736
(/
(+
1.421413741
(/
(+ (/ 1.061405429 (+ 1.0 (* 0.3275911 (fabs x)))) -1.453152027)
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
3.0))
(* (+ 1.0 (* 0.3275911 (fabs x))) (exp (* x x)))))))))double code(double x) {
return 1.0 - (((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (0.254829592 + ((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (-0.284496736 + ((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (1.421413741 + ((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (-1.453152027 + ((1.0 / (1.0 + (0.3275911 * fabs(x)))) * 1.061405429))))))))) * exp(-(fabs(x) * fabs(x))));
}
double code(double x) {
return cbrt(1.0 - (cbrt(pow((0.254829592 + ((-0.284496736 + ((1.421413741 + (((1.061405429 / (1.0 + (0.3275911 * fabs(x)))) + -1.453152027) / (1.0 + (0.3275911 * fabs(x))))) / (1.0 + (0.3275911 * fabs(x))))) / (1.0 + (0.3275911 * fabs(x))))), 3.0)) / ((1.0 + (0.3275911 * fabs(x))) * exp(x * x)))) * (cbrt(1.0 - (cbrt(pow((0.254829592 + ((-0.284496736 + ((1.421413741 + (((1.061405429 / (1.0 + (0.3275911 * fabs(x)))) + -1.453152027) / (1.0 + (0.3275911 * fabs(x))))) / (1.0 + (0.3275911 * fabs(x))))) / (1.0 + (0.3275911 * fabs(x))))), 3.0)) / ((1.0 + (0.3275911 * fabs(x))) * exp(x * x)))) * cbrt(1.0 - (cbrt(pow((0.254829592 + ((-0.284496736 + ((1.421413741 + (((1.061405429 / (1.0 + (0.3275911 * fabs(x)))) + -1.453152027) / (1.0 + (0.3275911 * fabs(x))))) / (1.0 + (0.3275911 * fabs(x))))) / (1.0 + (0.3275911 * fabs(x))))), 3.0)) / ((1.0 + (0.3275911 * fabs(x))) * exp(x * x)))));
}



Bits error versus x
Results
Initial program 13.9
Simplified13.9
rmApplied add-cbrt-cube_binary6413.9
Simplified13.9
rmApplied add-cube-cbrt_binary6413.9
Final simplification13.9
herbie shell --seed 2021118
(FPCore (x)
:name "Jmat.Real.erf"
:precision binary64
(- 1.0 (* (* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) (+ 0.254829592 (* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) (+ -0.284496736 (* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) (+ 1.421413741 (* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) (+ -1.453152027 (* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) 1.061405429))))))))) (exp (- (* (fabs x) (fabs x)))))))