
(FPCore (f) :precision binary64 (let* ((t_0 (* (/ PI 4.0) f)) (t_1 (exp t_0)) (t_2 (exp (- t_0)))) (- (* (/ 1.0 (/ PI 4.0)) (log (/ (+ t_1 t_2) (- t_1 t_2)))))))
double code(double f) {
double t_0 = (((double) M_PI) / 4.0) * f;
double t_1 = exp(t_0);
double t_2 = exp(-t_0);
return -((1.0 / (((double) M_PI) / 4.0)) * log(((t_1 + t_2) / (t_1 - t_2))));
}
public static double code(double f) {
double t_0 = (Math.PI / 4.0) * f;
double t_1 = Math.exp(t_0);
double t_2 = Math.exp(-t_0);
return -((1.0 / (Math.PI / 4.0)) * Math.log(((t_1 + t_2) / (t_1 - t_2))));
}
def code(f): t_0 = (math.pi / 4.0) * f t_1 = math.exp(t_0) t_2 = math.exp(-t_0) return -((1.0 / (math.pi / 4.0)) * math.log(((t_1 + t_2) / (t_1 - t_2))))
function code(f) t_0 = Float64(Float64(pi / 4.0) * f) t_1 = exp(t_0) t_2 = exp(Float64(-t_0)) return Float64(-Float64(Float64(1.0 / Float64(pi / 4.0)) * log(Float64(Float64(t_1 + t_2) / Float64(t_1 - t_2))))) end
function tmp = code(f) t_0 = (pi / 4.0) * f; t_1 = exp(t_0); t_2 = exp(-t_0); tmp = -((1.0 / (pi / 4.0)) * log(((t_1 + t_2) / (t_1 - t_2)))); end
code[f_] := Block[{t$95$0 = N[(N[(Pi / 4.0), $MachinePrecision] * f), $MachinePrecision]}, Block[{t$95$1 = N[Exp[t$95$0], $MachinePrecision]}, Block[{t$95$2 = N[Exp[(-t$95$0)], $MachinePrecision]}, (-N[(N[(1.0 / N[(Pi / 4.0), $MachinePrecision]), $MachinePrecision] * N[Log[N[(N[(t$95$1 + t$95$2), $MachinePrecision] / N[(t$95$1 - t$95$2), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision])]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{\pi}{4} \cdot f\\
t_1 := e^{t\_0}\\
t_2 := e^{-t\_0}\\
-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{t\_1 + t\_2}{t\_1 - t\_2}\right)
\end{array}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 7 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (f) :precision binary64 (let* ((t_0 (* (/ PI 4.0) f)) (t_1 (exp t_0)) (t_2 (exp (- t_0)))) (- (* (/ 1.0 (/ PI 4.0)) (log (/ (+ t_1 t_2) (- t_1 t_2)))))))
double code(double f) {
double t_0 = (((double) M_PI) / 4.0) * f;
double t_1 = exp(t_0);
double t_2 = exp(-t_0);
return -((1.0 / (((double) M_PI) / 4.0)) * log(((t_1 + t_2) / (t_1 - t_2))));
}
public static double code(double f) {
double t_0 = (Math.PI / 4.0) * f;
double t_1 = Math.exp(t_0);
double t_2 = Math.exp(-t_0);
return -((1.0 / (Math.PI / 4.0)) * Math.log(((t_1 + t_2) / (t_1 - t_2))));
}
def code(f): t_0 = (math.pi / 4.0) * f t_1 = math.exp(t_0) t_2 = math.exp(-t_0) return -((1.0 / (math.pi / 4.0)) * math.log(((t_1 + t_2) / (t_1 - t_2))))
function code(f) t_0 = Float64(Float64(pi / 4.0) * f) t_1 = exp(t_0) t_2 = exp(Float64(-t_0)) return Float64(-Float64(Float64(1.0 / Float64(pi / 4.0)) * log(Float64(Float64(t_1 + t_2) / Float64(t_1 - t_2))))) end
function tmp = code(f) t_0 = (pi / 4.0) * f; t_1 = exp(t_0); t_2 = exp(-t_0); tmp = -((1.0 / (pi / 4.0)) * log(((t_1 + t_2) / (t_1 - t_2)))); end
code[f_] := Block[{t$95$0 = N[(N[(Pi / 4.0), $MachinePrecision] * f), $MachinePrecision]}, Block[{t$95$1 = N[Exp[t$95$0], $MachinePrecision]}, Block[{t$95$2 = N[Exp[(-t$95$0)], $MachinePrecision]}, (-N[(N[(1.0 / N[(Pi / 4.0), $MachinePrecision]), $MachinePrecision] * N[Log[N[(N[(t$95$1 + t$95$2), $MachinePrecision] / N[(t$95$1 - t$95$2), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision])]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{\pi}{4} \cdot f\\
t_1 := e^{t\_0}\\
t_2 := e^{-t\_0}\\
-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{t\_1 + t\_2}{t\_1 - t\_2}\right)
\end{array}
\end{array}
(FPCore (f)
:precision binary64
(/
(log
(/
(* 2.0 (cosh (* (* PI 0.25) f)))
(fma
f
(* PI 0.5)
(fma
(pow f 3.0)
(* (pow PI 3.0) 0.005208333333333333)
(* (pow (* PI f) 5.0) 1.6276041666666666e-5)))))
(* PI (- 0.25))))
double code(double f) {
return log(((2.0 * cosh(((((double) M_PI) * 0.25) * f))) / fma(f, (((double) M_PI) * 0.5), fma(pow(f, 3.0), (pow(((double) M_PI), 3.0) * 0.005208333333333333), (pow((((double) M_PI) * f), 5.0) * 1.6276041666666666e-5))))) / (((double) M_PI) * -0.25);
}
function code(f) return Float64(log(Float64(Float64(2.0 * cosh(Float64(Float64(pi * 0.25) * f))) / fma(f, Float64(pi * 0.5), fma((f ^ 3.0), Float64((pi ^ 3.0) * 0.005208333333333333), Float64((Float64(pi * f) ^ 5.0) * 1.6276041666666666e-5))))) / Float64(pi * Float64(-0.25))) end
code[f_] := N[(N[Log[N[(N[(2.0 * N[Cosh[N[(N[(Pi * 0.25), $MachinePrecision] * f), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(f * N[(Pi * 0.5), $MachinePrecision] + N[(N[Power[f, 3.0], $MachinePrecision] * N[(N[Power[Pi, 3.0], $MachinePrecision] * 0.005208333333333333), $MachinePrecision] + N[(N[Power[N[(Pi * f), $MachinePrecision], 5.0], $MachinePrecision] * 1.6276041666666666e-5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / N[(Pi * (-0.25)), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\log \left(\frac{2 \cdot \cosh \left(\left(\pi \cdot 0.25\right) \cdot f\right)}{\mathsf{fma}\left(f, \pi \cdot 0.5, \mathsf{fma}\left({f}^{3}, {\pi}^{3} \cdot 0.005208333333333333, {\left(\pi \cdot f\right)}^{5} \cdot 1.6276041666666666 \cdot 10^{-5}\right)\right)}\right)}{\pi \cdot \left(-0.25\right)}
\end{array}
Initial program 6.9%
Taylor expanded in f around 0 94.7%
fma-define94.7%
distribute-rgt-out--94.7%
metadata-eval94.7%
fma-define94.7%
distribute-rgt-out--94.7%
metadata-eval94.7%
distribute-rgt-out--94.7%
metadata-eval94.7%
Simplified94.7%
div-inv94.7%
log-prod94.8%
cosh-undef94.8%
div-inv94.8%
metadata-eval94.8%
Applied egg-rr94.8%
log-rec94.8%
sub-neg94.8%
log-div94.7%
associate-*l*94.7%
*-commutative94.7%
Simplified94.7%
associate-*l/94.8%
*-un-lft-identity94.8%
associate-*r*94.8%
div-inv94.8%
metadata-eval94.8%
Applied egg-rr94.8%
Final simplification94.8%
(FPCore (f) :precision binary64 (+ (* 2.0 (* (pow f 2.0) (- (* PI 0.020833333333333332) (* PI 0.0625)))) (* 4.0 (/ (- (log f) (log (/ 4.0 PI))) PI))))
double code(double f) {
return (2.0 * (pow(f, 2.0) * ((((double) M_PI) * 0.020833333333333332) - (((double) M_PI) * 0.0625)))) + (4.0 * ((log(f) - log((4.0 / ((double) M_PI)))) / ((double) M_PI)));
}
public static double code(double f) {
return (2.0 * (Math.pow(f, 2.0) * ((Math.PI * 0.020833333333333332) - (Math.PI * 0.0625)))) + (4.0 * ((Math.log(f) - Math.log((4.0 / Math.PI))) / Math.PI));
}
def code(f): return (2.0 * (math.pow(f, 2.0) * ((math.pi * 0.020833333333333332) - (math.pi * 0.0625)))) + (4.0 * ((math.log(f) - math.log((4.0 / math.pi))) / math.pi))
function code(f) return Float64(Float64(2.0 * Float64((f ^ 2.0) * Float64(Float64(pi * 0.020833333333333332) - Float64(pi * 0.0625)))) + Float64(4.0 * Float64(Float64(log(f) - log(Float64(4.0 / pi))) / pi))) end
function tmp = code(f) tmp = (2.0 * ((f ^ 2.0) * ((pi * 0.020833333333333332) - (pi * 0.0625)))) + (4.0 * ((log(f) - log((4.0 / pi))) / pi)); end
code[f_] := N[(N[(2.0 * N[(N[Power[f, 2.0], $MachinePrecision] * N[(N[(Pi * 0.020833333333333332), $MachinePrecision] - N[(Pi * 0.0625), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(4.0 * N[(N[(N[Log[f], $MachinePrecision] - N[Log[N[(4.0 / Pi), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / Pi), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
2 \cdot \left({f}^{2} \cdot \left(\pi \cdot 0.020833333333333332 - \pi \cdot 0.0625\right)\right) + 4 \cdot \frac{\log f - \log \left(\frac{4}{\pi}\right)}{\pi}
\end{array}
Initial program 6.9%
Taylor expanded in f around 0 94.7%
fma-define94.7%
distribute-rgt-out--94.7%
metadata-eval94.7%
fma-define94.7%
distribute-rgt-out--94.7%
metadata-eval94.7%
distribute-rgt-out--94.7%
metadata-eval94.7%
Simplified94.7%
div-inv94.7%
log-prod94.8%
cosh-undef94.8%
div-inv94.8%
metadata-eval94.8%
Applied egg-rr94.8%
log-rec94.8%
sub-neg94.8%
log-div94.7%
associate-*l*94.7%
*-commutative94.7%
Simplified94.7%
Taylor expanded in f around 0 94.7%
Final simplification94.7%
(FPCore (f) :precision binary64 (- (fma 4.0 (/ (log (/ 4.0 (* PI f))) PI) (* (pow f 2.0) (* 2.0 (* PI 0.041666666666666664))))))
double code(double f) {
return -fma(4.0, (log((4.0 / (((double) M_PI) * f))) / ((double) M_PI)), (pow(f, 2.0) * (2.0 * (((double) M_PI) * 0.041666666666666664))));
}
function code(f) return Float64(-fma(4.0, Float64(log(Float64(4.0 / Float64(pi * f))) / pi), Float64((f ^ 2.0) * Float64(2.0 * Float64(pi * 0.041666666666666664))))) end
code[f_] := (-N[(4.0 * N[(N[Log[N[(4.0 / N[(Pi * f), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / Pi), $MachinePrecision] + N[(N[Power[f, 2.0], $MachinePrecision] * N[(2.0 * N[(Pi * 0.041666666666666664), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision])
\begin{array}{l}
\\
-\mathsf{fma}\left(4, \frac{\log \left(\frac{4}{\pi \cdot f}\right)}{\pi}, {f}^{2} \cdot \left(2 \cdot \left(\pi \cdot 0.041666666666666664\right)\right)\right)
\end{array}
Initial program 6.9%
Taylor expanded in f around 0 94.7%
fma-define94.7%
distribute-rgt-out--94.7%
metadata-eval94.7%
fma-define94.7%
distribute-rgt-out--94.7%
metadata-eval94.7%
distribute-rgt-out--94.7%
metadata-eval94.7%
Simplified94.7%
div-inv94.7%
log-prod94.8%
cosh-undef94.8%
div-inv94.8%
metadata-eval94.8%
Applied egg-rr94.8%
log-rec94.8%
sub-neg94.8%
log-div94.7%
associate-*l*94.7%
*-commutative94.7%
Simplified94.7%
Taylor expanded in f around 0 94.7%
+-commutative94.7%
mul-1-neg94.7%
log-rec94.7%
+-commutative94.7%
fma-define94.7%
Simplified94.6%
Final simplification94.6%
(FPCore (f) :precision binary64 (* (/ (- (log (/ 2.0 (* PI 0.5))) (log f)) PI) -4.0))
double code(double f) {
return ((log((2.0 / (((double) M_PI) * 0.5))) - log(f)) / ((double) M_PI)) * -4.0;
}
public static double code(double f) {
return ((Math.log((2.0 / (Math.PI * 0.5))) - Math.log(f)) / Math.PI) * -4.0;
}
def code(f): return ((math.log((2.0 / (math.pi * 0.5))) - math.log(f)) / math.pi) * -4.0
function code(f) return Float64(Float64(Float64(log(Float64(2.0 / Float64(pi * 0.5))) - log(f)) / pi) * -4.0) end
function tmp = code(f) tmp = ((log((2.0 / (pi * 0.5))) - log(f)) / pi) * -4.0; end
code[f_] := N[(N[(N[(N[Log[N[(2.0 / N[(Pi * 0.5), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - N[Log[f], $MachinePrecision]), $MachinePrecision] / Pi), $MachinePrecision] * -4.0), $MachinePrecision]
\begin{array}{l}
\\
\frac{\log \left(\frac{2}{\pi \cdot 0.5}\right) - \log f}{\pi} \cdot -4
\end{array}
Initial program 6.9%
*-commutative6.9%
distribute-rgt-neg-in6.9%
Simplified6.8%
Taylor expanded in f around 0 94.2%
*-commutative94.2%
mul-1-neg94.2%
unsub-neg94.2%
distribute-rgt-out--94.2%
metadata-eval94.2%
Simplified94.2%
Final simplification94.2%
(FPCore (f) :precision binary64 (* (log (+ (* 0.125 (* PI f)) (* 4.0 (/ 1.0 (* PI f))))) (/ -1.0 (/ PI 4.0))))
double code(double f) {
return log(((0.125 * (((double) M_PI) * f)) + (4.0 * (1.0 / (((double) M_PI) * f))))) * (-1.0 / (((double) M_PI) / 4.0));
}
public static double code(double f) {
return Math.log(((0.125 * (Math.PI * f)) + (4.0 * (1.0 / (Math.PI * f))))) * (-1.0 / (Math.PI / 4.0));
}
def code(f): return math.log(((0.125 * (math.pi * f)) + (4.0 * (1.0 / (math.pi * f))))) * (-1.0 / (math.pi / 4.0))
function code(f) return Float64(log(Float64(Float64(0.125 * Float64(pi * f)) + Float64(4.0 * Float64(1.0 / Float64(pi * f))))) * Float64(-1.0 / Float64(pi / 4.0))) end
function tmp = code(f) tmp = log(((0.125 * (pi * f)) + (4.0 * (1.0 / (pi * f))))) * (-1.0 / (pi / 4.0)); end
code[f_] := N[(N[Log[N[(N[(0.125 * N[(Pi * f), $MachinePrecision]), $MachinePrecision] + N[(4.0 * N[(1.0 / N[(Pi * f), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[(-1.0 / N[(Pi / 4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\log \left(0.125 \cdot \left(\pi \cdot f\right) + 4 \cdot \frac{1}{\pi \cdot f}\right) \cdot \frac{-1}{\frac{\pi}{4}}
\end{array}
Initial program 6.9%
Taylor expanded in f around 0 94.1%
distribute-rgt-out--94.1%
metadata-eval94.1%
Simplified94.1%
Taylor expanded in f around 0 94.2%
Final simplification94.2%
(FPCore (f) :precision binary64 (* -4.0 (/ (log (/ (/ 4.0 f) PI)) PI)))
double code(double f) {
return -4.0 * (log(((4.0 / f) / ((double) M_PI))) / ((double) M_PI));
}
public static double code(double f) {
return -4.0 * (Math.log(((4.0 / f) / Math.PI)) / Math.PI);
}
def code(f): return -4.0 * (math.log(((4.0 / f) / math.pi)) / math.pi)
function code(f) return Float64(-4.0 * Float64(log(Float64(Float64(4.0 / f) / pi)) / pi)) end
function tmp = code(f) tmp = -4.0 * (log(((4.0 / f) / pi)) / pi); end
code[f_] := N[(-4.0 * N[(N[Log[N[(N[(4.0 / f), $MachinePrecision] / Pi), $MachinePrecision]], $MachinePrecision] / Pi), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
-4 \cdot \frac{\log \left(\frac{\frac{4}{f}}{\pi}\right)}{\pi}
\end{array}
Initial program 6.9%
*-commutative6.9%
distribute-rgt-neg-in6.9%
Simplified6.8%
Taylor expanded in f around 0 94.2%
*-commutative94.2%
mul-1-neg94.2%
unsub-neg94.2%
distribute-rgt-out--94.2%
metadata-eval94.2%
Simplified94.2%
Taylor expanded in f around 0 94.2%
div-sub94.0%
metadata-eval94.0%
associate-/r*94.0%
*-commutative94.0%
div-sub94.2%
log-div94.1%
associate-/l/94.1%
associate-*r*94.1%
*-commutative94.1%
associate-/r*94.1%
metadata-eval94.1%
*-commutative94.1%
associate-/r*94.1%
Simplified94.1%
Taylor expanded in f around 0 94.1%
associate-/r*94.1%
Simplified94.1%
Final simplification94.1%
(FPCore (f) :precision binary64 (* (/ (log 0.0) PI) (- 4.0)))
double code(double f) {
return (log(0.0) / ((double) M_PI)) * -4.0;
}
public static double code(double f) {
return (Math.log(0.0) / Math.PI) * -4.0;
}
def code(f): return (math.log(0.0) / math.pi) * -4.0
function code(f) return Float64(Float64(log(0.0) / pi) * Float64(-4.0)) end
function tmp = code(f) tmp = (log(0.0) / pi) * -4.0; end
code[f_] := N[(N[(N[Log[0.0], $MachinePrecision] / Pi), $MachinePrecision] * (-4.0)), $MachinePrecision]
\begin{array}{l}
\\
\frac{\log 0}{\pi} \cdot \left(-4\right)
\end{array}
Initial program 6.9%
Taylor expanded in f around 0 94.0%
Taylor expanded in f around inf 0.7%
distribute-rgt-out0.7%
distribute-rgt-out--0.7%
metadata-eval0.7%
metadata-eval0.7%
mul0-rgt0.7%
Simplified0.7%
Final simplification0.7%
herbie shell --seed 2024045
(FPCore (f)
:name "VandenBroeck and Keller, Equation (20)"
:precision binary64
(- (* (/ 1.0 (/ PI 4.0)) (log (/ (+ (exp (* (/ PI 4.0) f)) (exp (- (* (/ PI 4.0) f)))) (- (exp (* (/ PI 4.0) f)) (exp (- (* (/ PI 4.0) f)))))))))