
(FPCore (x)
:precision binary64
(let* ((t_0 (/ 1.0 (fabs x)))
(t_1 (* (* t_0 t_0) t_0))
(t_2 (* (* t_1 t_0) t_0)))
(*
(* (/ 1.0 (sqrt PI)) (exp (* (fabs x) (fabs x))))
(+
(+ (+ t_0 (* (/ 1.0 2.0) t_1)) (* (/ 3.0 4.0) t_2))
(* (/ 15.0 8.0) (* (* t_2 t_0) t_0))))))
double code(double x) {
double t_0 = 1.0 / fabs(x);
double t_1 = (t_0 * t_0) * t_0;
double t_2 = (t_1 * t_0) * t_0;
return ((1.0 / sqrt(((double) M_PI))) * exp((fabs(x) * fabs(x)))) * (((t_0 + ((1.0 / 2.0) * t_1)) + ((3.0 / 4.0) * t_2)) + ((15.0 / 8.0) * ((t_2 * t_0) * t_0)));
}
public static double code(double x) {
double t_0 = 1.0 / Math.abs(x);
double t_1 = (t_0 * t_0) * t_0;
double t_2 = (t_1 * t_0) * t_0;
return ((1.0 / Math.sqrt(Math.PI)) * Math.exp((Math.abs(x) * Math.abs(x)))) * (((t_0 + ((1.0 / 2.0) * t_1)) + ((3.0 / 4.0) * t_2)) + ((15.0 / 8.0) * ((t_2 * t_0) * t_0)));
}
def code(x): t_0 = 1.0 / math.fabs(x) t_1 = (t_0 * t_0) * t_0 t_2 = (t_1 * t_0) * t_0 return ((1.0 / math.sqrt(math.pi)) * math.exp((math.fabs(x) * math.fabs(x)))) * (((t_0 + ((1.0 / 2.0) * t_1)) + ((3.0 / 4.0) * t_2)) + ((15.0 / 8.0) * ((t_2 * t_0) * t_0)))
function code(x) t_0 = Float64(1.0 / abs(x)) t_1 = Float64(Float64(t_0 * t_0) * t_0) t_2 = Float64(Float64(t_1 * t_0) * t_0) return Float64(Float64(Float64(1.0 / sqrt(pi)) * exp(Float64(abs(x) * abs(x)))) * Float64(Float64(Float64(t_0 + Float64(Float64(1.0 / 2.0) * t_1)) + Float64(Float64(3.0 / 4.0) * t_2)) + Float64(Float64(15.0 / 8.0) * Float64(Float64(t_2 * t_0) * t_0)))) end
function tmp = code(x) t_0 = 1.0 / abs(x); t_1 = (t_0 * t_0) * t_0; t_2 = (t_1 * t_0) * t_0; tmp = ((1.0 / sqrt(pi)) * exp((abs(x) * abs(x)))) * (((t_0 + ((1.0 / 2.0) * t_1)) + ((3.0 / 4.0) * t_2)) + ((15.0 / 8.0) * ((t_2 * t_0) * t_0))); end
code[x_] := Block[{t$95$0 = N[(1.0 / N[Abs[x], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(t$95$0 * t$95$0), $MachinePrecision] * t$95$0), $MachinePrecision]}, Block[{t$95$2 = N[(N[(t$95$1 * t$95$0), $MachinePrecision] * t$95$0), $MachinePrecision]}, N[(N[(N[(1.0 / N[Sqrt[Pi], $MachinePrecision]), $MachinePrecision] * N[Exp[N[(N[Abs[x], $MachinePrecision] * N[Abs[x], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(N[(N[(t$95$0 + N[(N[(1.0 / 2.0), $MachinePrecision] * t$95$1), $MachinePrecision]), $MachinePrecision] + N[(N[(3.0 / 4.0), $MachinePrecision] * t$95$2), $MachinePrecision]), $MachinePrecision] + N[(N[(15.0 / 8.0), $MachinePrecision] * N[(N[(t$95$2 * t$95$0), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{1}{\left|x\right|}\\
t_1 := \left(t_0 \cdot t_0\right) \cdot t_0\\
t_2 := \left(t_1 \cdot t_0\right) \cdot t_0\\
\left(\frac{1}{\sqrt{\pi}} \cdot e^{\left|x\right| \cdot \left|x\right|}\right) \cdot \left(\left(\left(t_0 + \frac{1}{2} \cdot t_1\right) + \frac{3}{4} \cdot t_2\right) + \frac{15}{8} \cdot \left(\left(t_2 \cdot t_0\right) \cdot t_0\right)\right)
\end{array}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 2 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x)
:precision binary64
(let* ((t_0 (/ 1.0 (fabs x)))
(t_1 (* (* t_0 t_0) t_0))
(t_2 (* (* t_1 t_0) t_0)))
(*
(* (/ 1.0 (sqrt PI)) (exp (* (fabs x) (fabs x))))
(+
(+ (+ t_0 (* (/ 1.0 2.0) t_1)) (* (/ 3.0 4.0) t_2))
(* (/ 15.0 8.0) (* (* t_2 t_0) t_0))))))
double code(double x) {
double t_0 = 1.0 / fabs(x);
double t_1 = (t_0 * t_0) * t_0;
double t_2 = (t_1 * t_0) * t_0;
return ((1.0 / sqrt(((double) M_PI))) * exp((fabs(x) * fabs(x)))) * (((t_0 + ((1.0 / 2.0) * t_1)) + ((3.0 / 4.0) * t_2)) + ((15.0 / 8.0) * ((t_2 * t_0) * t_0)));
}
public static double code(double x) {
double t_0 = 1.0 / Math.abs(x);
double t_1 = (t_0 * t_0) * t_0;
double t_2 = (t_1 * t_0) * t_0;
return ((1.0 / Math.sqrt(Math.PI)) * Math.exp((Math.abs(x) * Math.abs(x)))) * (((t_0 + ((1.0 / 2.0) * t_1)) + ((3.0 / 4.0) * t_2)) + ((15.0 / 8.0) * ((t_2 * t_0) * t_0)));
}
def code(x): t_0 = 1.0 / math.fabs(x) t_1 = (t_0 * t_0) * t_0 t_2 = (t_1 * t_0) * t_0 return ((1.0 / math.sqrt(math.pi)) * math.exp((math.fabs(x) * math.fabs(x)))) * (((t_0 + ((1.0 / 2.0) * t_1)) + ((3.0 / 4.0) * t_2)) + ((15.0 / 8.0) * ((t_2 * t_0) * t_0)))
function code(x) t_0 = Float64(1.0 / abs(x)) t_1 = Float64(Float64(t_0 * t_0) * t_0) t_2 = Float64(Float64(t_1 * t_0) * t_0) return Float64(Float64(Float64(1.0 / sqrt(pi)) * exp(Float64(abs(x) * abs(x)))) * Float64(Float64(Float64(t_0 + Float64(Float64(1.0 / 2.0) * t_1)) + Float64(Float64(3.0 / 4.0) * t_2)) + Float64(Float64(15.0 / 8.0) * Float64(Float64(t_2 * t_0) * t_0)))) end
function tmp = code(x) t_0 = 1.0 / abs(x); t_1 = (t_0 * t_0) * t_0; t_2 = (t_1 * t_0) * t_0; tmp = ((1.0 / sqrt(pi)) * exp((abs(x) * abs(x)))) * (((t_0 + ((1.0 / 2.0) * t_1)) + ((3.0 / 4.0) * t_2)) + ((15.0 / 8.0) * ((t_2 * t_0) * t_0))); end
code[x_] := Block[{t$95$0 = N[(1.0 / N[Abs[x], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(t$95$0 * t$95$0), $MachinePrecision] * t$95$0), $MachinePrecision]}, Block[{t$95$2 = N[(N[(t$95$1 * t$95$0), $MachinePrecision] * t$95$0), $MachinePrecision]}, N[(N[(N[(1.0 / N[Sqrt[Pi], $MachinePrecision]), $MachinePrecision] * N[Exp[N[(N[Abs[x], $MachinePrecision] * N[Abs[x], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(N[(N[(t$95$0 + N[(N[(1.0 / 2.0), $MachinePrecision] * t$95$1), $MachinePrecision]), $MachinePrecision] + N[(N[(3.0 / 4.0), $MachinePrecision] * t$95$2), $MachinePrecision]), $MachinePrecision] + N[(N[(15.0 / 8.0), $MachinePrecision] * N[(N[(t$95$2 * t$95$0), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{1}{\left|x\right|}\\
t_1 := \left(t_0 \cdot t_0\right) \cdot t_0\\
t_2 := \left(t_1 \cdot t_0\right) \cdot t_0\\
\left(\frac{1}{\sqrt{\pi}} \cdot e^{\left|x\right| \cdot \left|x\right|}\right) \cdot \left(\left(\left(t_0 + \frac{1}{2} \cdot t_1\right) + \frac{3}{4} \cdot t_2\right) + \frac{15}{8} \cdot \left(\left(t_2 \cdot t_0\right) \cdot t_0\right)\right)
\end{array}
\end{array}
(FPCore (x)
:precision binary64
(let* ((t_0 (/ 1.0 (fabs x))))
(*
(* (/ 1.0 (sqrt PI)) (exp (* x x)))
(+
(+ (+ t_0 (* 0.5 (/ (/ 1.0 x) (* x x)))) (* 0.75 (pow x -5.0)))
(* 1.875 (* t_0 (* t_0 (pow (pow x -0.5) 10.0))))))))
double code(double x) {
double t_0 = 1.0 / fabs(x);
return ((1.0 / sqrt(((double) M_PI))) * exp((x * x))) * (((t_0 + (0.5 * ((1.0 / x) / (x * x)))) + (0.75 * pow(x, -5.0))) + (1.875 * (t_0 * (t_0 * pow(pow(x, -0.5), 10.0)))));
}
public static double code(double x) {
double t_0 = 1.0 / Math.abs(x);
return ((1.0 / Math.sqrt(Math.PI)) * Math.exp((x * x))) * (((t_0 + (0.5 * ((1.0 / x) / (x * x)))) + (0.75 * Math.pow(x, -5.0))) + (1.875 * (t_0 * (t_0 * Math.pow(Math.pow(x, -0.5), 10.0)))));
}
def code(x): t_0 = 1.0 / math.fabs(x) return ((1.0 / math.sqrt(math.pi)) * math.exp((x * x))) * (((t_0 + (0.5 * ((1.0 / x) / (x * x)))) + (0.75 * math.pow(x, -5.0))) + (1.875 * (t_0 * (t_0 * math.pow(math.pow(x, -0.5), 10.0)))))
function code(x) t_0 = Float64(1.0 / abs(x)) return Float64(Float64(Float64(1.0 / sqrt(pi)) * exp(Float64(x * x))) * Float64(Float64(Float64(t_0 + Float64(0.5 * Float64(Float64(1.0 / x) / Float64(x * x)))) + Float64(0.75 * (x ^ -5.0))) + Float64(1.875 * Float64(t_0 * Float64(t_0 * ((x ^ -0.5) ^ 10.0)))))) end
function tmp = code(x) t_0 = 1.0 / abs(x); tmp = ((1.0 / sqrt(pi)) * exp((x * x))) * (((t_0 + (0.5 * ((1.0 / x) / (x * x)))) + (0.75 * (x ^ -5.0))) + (1.875 * (t_0 * (t_0 * ((x ^ -0.5) ^ 10.0))))); end
code[x_] := Block[{t$95$0 = N[(1.0 / N[Abs[x], $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(1.0 / N[Sqrt[Pi], $MachinePrecision]), $MachinePrecision] * N[Exp[N[(x * x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(N[(N[(t$95$0 + N[(0.5 * N[(N[(1.0 / x), $MachinePrecision] / N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.75 * N[Power[x, -5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(1.875 * N[(t$95$0 * N[(t$95$0 * N[Power[N[Power[x, -0.5], $MachinePrecision], 10.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{1}{\left|x\right|}\\
\left(\frac{1}{\sqrt{\pi}} \cdot e^{x \cdot x}\right) \cdot \left(\left(\left(t_0 + 0.5 \cdot \frac{\frac{1}{x}}{x \cdot x}\right) + 0.75 \cdot {x}^{-5}\right) + 1.875 \cdot \left(t_0 \cdot \left(t_0 \cdot {\left({x}^{-0.5}\right)}^{10}\right)\right)\right)
\end{array}
\end{array}
Initial program 100.0%
Taylor expanded in x around 0 100.0%
rem-square-sqrt100.0%
fabs-sqr100.0%
rem-square-sqrt100.0%
exp-to-pow100.0%
exp-neg100.0%
distribute-lft-neg-out100.0%
*-commutative100.0%
neg-mul-1100.0%
associate-*r*100.0%
metadata-eval100.0%
log-pow100.0%
rem-exp-log100.0%
Simplified100.0%
associate-*l*100.0%
pow3100.0%
pow2100.0%
pow-prod-up100.0%
add-sqr-sqrt100.0%
pow2100.0%
pow-pow100.0%
inv-pow100.0%
sqrt-pow1100.0%
add-sqr-sqrt100.0%
fabs-sqr100.0%
add-sqr-sqrt100.0%
metadata-eval100.0%
metadata-eval100.0%
metadata-eval100.0%
Applied egg-rr100.0%
un-div-inv100.0%
frac-times100.0%
*-rgt-identity100.0%
add-sqr-sqrt100.0%
fabs-sqr100.0%
add-sqr-sqrt100.0%
pow2100.0%
add-sqr-sqrt100.0%
fabs-sqr100.0%
add-sqr-sqrt100.0%
pow2100.0%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (x)
:precision binary64
(let* ((t_0 (/ 1.0 (fabs x))))
(*
(* (/ 1.0 (sqrt PI)) (exp (* x x)))
(+
(+ (+ t_0 (* 0.5 (/ (/ 1.0 x) (* x x)))) (* 0.75 (pow x -5.0)))
(* 1.875 (* t_0 (pow x -6.0)))))))
double code(double x) {
double t_0 = 1.0 / fabs(x);
return ((1.0 / sqrt(((double) M_PI))) * exp((x * x))) * (((t_0 + (0.5 * ((1.0 / x) / (x * x)))) + (0.75 * pow(x, -5.0))) + (1.875 * (t_0 * pow(x, -6.0))));
}
public static double code(double x) {
double t_0 = 1.0 / Math.abs(x);
return ((1.0 / Math.sqrt(Math.PI)) * Math.exp((x * x))) * (((t_0 + (0.5 * ((1.0 / x) / (x * x)))) + (0.75 * Math.pow(x, -5.0))) + (1.875 * (t_0 * Math.pow(x, -6.0))));
}
def code(x): t_0 = 1.0 / math.fabs(x) return ((1.0 / math.sqrt(math.pi)) * math.exp((x * x))) * (((t_0 + (0.5 * ((1.0 / x) / (x * x)))) + (0.75 * math.pow(x, -5.0))) + (1.875 * (t_0 * math.pow(x, -6.0))))
function code(x) t_0 = Float64(1.0 / abs(x)) return Float64(Float64(Float64(1.0 / sqrt(pi)) * exp(Float64(x * x))) * Float64(Float64(Float64(t_0 + Float64(0.5 * Float64(Float64(1.0 / x) / Float64(x * x)))) + Float64(0.75 * (x ^ -5.0))) + Float64(1.875 * Float64(t_0 * (x ^ -6.0))))) end
function tmp = code(x) t_0 = 1.0 / abs(x); tmp = ((1.0 / sqrt(pi)) * exp((x * x))) * (((t_0 + (0.5 * ((1.0 / x) / (x * x)))) + (0.75 * (x ^ -5.0))) + (1.875 * (t_0 * (x ^ -6.0)))); end
code[x_] := Block[{t$95$0 = N[(1.0 / N[Abs[x], $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(1.0 / N[Sqrt[Pi], $MachinePrecision]), $MachinePrecision] * N[Exp[N[(x * x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(N[(N[(t$95$0 + N[(0.5 * N[(N[(1.0 / x), $MachinePrecision] / N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.75 * N[Power[x, -5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(1.875 * N[(t$95$0 * N[Power[x, -6.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{1}{\left|x\right|}\\
\left(\frac{1}{\sqrt{\pi}} \cdot e^{x \cdot x}\right) \cdot \left(\left(\left(t_0 + 0.5 \cdot \frac{\frac{1}{x}}{x \cdot x}\right) + 0.75 \cdot {x}^{-5}\right) + 1.875 \cdot \left(t_0 \cdot {x}^{-6}\right)\right)
\end{array}
\end{array}
Initial program 100.0%
Taylor expanded in x around 0 100.0%
rem-square-sqrt100.0%
fabs-sqr100.0%
rem-square-sqrt100.0%
exp-to-pow100.0%
exp-neg100.0%
distribute-lft-neg-out100.0%
*-commutative100.0%
neg-mul-1100.0%
associate-*r*100.0%
metadata-eval100.0%
log-pow100.0%
rem-exp-log100.0%
Simplified100.0%
associate-*l*100.0%
pow3100.0%
pow2100.0%
pow-prod-up100.0%
add-sqr-sqrt100.0%
pow2100.0%
pow-pow100.0%
inv-pow100.0%
sqrt-pow1100.0%
add-sqr-sqrt100.0%
fabs-sqr100.0%
add-sqr-sqrt100.0%
metadata-eval100.0%
metadata-eval100.0%
metadata-eval100.0%
Applied egg-rr100.0%
un-div-inv100.0%
frac-times100.0%
*-rgt-identity100.0%
add-sqr-sqrt100.0%
fabs-sqr100.0%
add-sqr-sqrt100.0%
pow2100.0%
add-sqr-sqrt100.0%
fabs-sqr100.0%
add-sqr-sqrt100.0%
pow2100.0%
Applied egg-rr100.0%
Taylor expanded in x around 0 100.0%
*-commutative100.0%
metadata-eval100.0%
pow-plus100.0%
metadata-eval100.0%
pow-sqr100.0%
unpow2100.0%
unpow2100.0%
rem-square-sqrt100.0%
fabs-sqr100.0%
rem-square-sqrt100.0%
associate-*r*100.0%
unpow3100.0%
cube-prod100.0%
associate-/r*100.0%
metadata-eval100.0%
cube-div100.0%
unpow-1100.0%
exp-to-pow100.0%
exp-prod100.0%
associate-*l*100.0%
metadata-eval100.0%
exp-to-pow100.0%
Simplified100.0%
Final simplification100.0%
herbie shell --seed 2023174
(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)))))))