
(FPCore (v t) :precision binary64 (/ (- 1.0 (* 5.0 (* v v))) (* (* (* PI t) (sqrt (* 2.0 (- 1.0 (* 3.0 (* v v)))))) (- 1.0 (* v v)))))
double code(double v, double t) {
return (1.0 - (5.0 * (v * v))) / (((((double) M_PI) * t) * sqrt((2.0 * (1.0 - (3.0 * (v * v)))))) * (1.0 - (v * v)));
}
public static double code(double v, double t) {
return (1.0 - (5.0 * (v * v))) / (((Math.PI * t) * Math.sqrt((2.0 * (1.0 - (3.0 * (v * v)))))) * (1.0 - (v * v)));
}
def code(v, t): return (1.0 - (5.0 * (v * v))) / (((math.pi * t) * math.sqrt((2.0 * (1.0 - (3.0 * (v * v)))))) * (1.0 - (v * v)))
function code(v, t) return Float64(Float64(1.0 - Float64(5.0 * Float64(v * v))) / Float64(Float64(Float64(pi * t) * sqrt(Float64(2.0 * Float64(1.0 - Float64(3.0 * Float64(v * v)))))) * Float64(1.0 - Float64(v * v)))) end
function tmp = code(v, t) tmp = (1.0 - (5.0 * (v * v))) / (((pi * t) * sqrt((2.0 * (1.0 - (3.0 * (v * v)))))) * (1.0 - (v * v))); end
code[v_, t_] := N[(N[(1.0 - N[(5.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(N[(Pi * t), $MachinePrecision] * N[Sqrt[N[(2.0 * N[(1.0 - N[(3.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1 - 5 \cdot \left(v \cdot v\right)}{\left(\left(\pi \cdot t\right) \cdot \sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)}\right) \cdot \left(1 - v \cdot v\right)}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 3 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (v t) :precision binary64 (/ (- 1.0 (* 5.0 (* v v))) (* (* (* PI t) (sqrt (* 2.0 (- 1.0 (* 3.0 (* v v)))))) (- 1.0 (* v v)))))
double code(double v, double t) {
return (1.0 - (5.0 * (v * v))) / (((((double) M_PI) * t) * sqrt((2.0 * (1.0 - (3.0 * (v * v)))))) * (1.0 - (v * v)));
}
public static double code(double v, double t) {
return (1.0 - (5.0 * (v * v))) / (((Math.PI * t) * Math.sqrt((2.0 * (1.0 - (3.0 * (v * v)))))) * (1.0 - (v * v)));
}
def code(v, t): return (1.0 - (5.0 * (v * v))) / (((math.pi * t) * math.sqrt((2.0 * (1.0 - (3.0 * (v * v)))))) * (1.0 - (v * v)))
function code(v, t) return Float64(Float64(1.0 - Float64(5.0 * Float64(v * v))) / Float64(Float64(Float64(pi * t) * sqrt(Float64(2.0 * Float64(1.0 - Float64(3.0 * Float64(v * v)))))) * Float64(1.0 - Float64(v * v)))) end
function tmp = code(v, t) tmp = (1.0 - (5.0 * (v * v))) / (((pi * t) * sqrt((2.0 * (1.0 - (3.0 * (v * v)))))) * (1.0 - (v * v))); end
code[v_, t_] := N[(N[(1.0 - N[(5.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(N[(Pi * t), $MachinePrecision] * N[Sqrt[N[(2.0 * N[(1.0 - N[(3.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1 - 5 \cdot \left(v \cdot v\right)}{\left(\left(\pi \cdot t\right) \cdot \sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)}\right) \cdot \left(1 - v \cdot v\right)}
\end{array}
(FPCore (v t) :precision binary64 (/ (- 1.0 (* 5.0 (* v v))) (* (* PI (* t (sqrt (* (fma -3.0 (* v v) 1.0) 2.0)))) (- 1.0 (* v v)))))
double code(double v, double t) {
return (1.0 - (5.0 * (v * v))) / ((((double) M_PI) * (t * sqrt((fma(-3.0, (v * v), 1.0) * 2.0)))) * (1.0 - (v * v)));
}
function code(v, t) return Float64(Float64(1.0 - Float64(5.0 * Float64(v * v))) / Float64(Float64(pi * Float64(t * sqrt(Float64(fma(-3.0, Float64(v * v), 1.0) * 2.0)))) * Float64(1.0 - Float64(v * v)))) end
code[v_, t_] := N[(N[(1.0 - N[(5.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(Pi * N[(t * N[Sqrt[N[(N[(-3.0 * N[(v * v), $MachinePrecision] + 1.0), $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1 - 5 \cdot \left(v \cdot v\right)}{\left(\pi \cdot \left(t \cdot \sqrt{\mathsf{fma}\left(-3, v \cdot v, 1\right) \cdot 2}\right)\right) \cdot \left(1 - v \cdot v\right)}
\end{array}
Initial program 99.3%
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
lift-sqrt.f64N/A
lift-*.f64N/A
lift--.f64N/A
lift-*.f64N/A
lift-*.f64N/A
associate-*l*N/A
lower-*.f64N/A
lift-PI.f64N/A
lower-*.f64N/A
lower-sqrt.f64N/A
*-commutativeN/A
lower-*.f64N/A
Applied rewrites99.4%
(FPCore (v t) :precision binary64 (/ (- 1.0 (* 5.0 (exp (* (log v) 2.0)))) (* (* (* PI t) (sqrt (* 2.0 (- 1.0 (* 3.0 (* v v)))))) (- 1.0 (* v v)))))
double code(double v, double t) {
return (1.0 - (5.0 * exp((log(v) * 2.0)))) / (((((double) M_PI) * t) * sqrt((2.0 * (1.0 - (3.0 * (v * v)))))) * (1.0 - (v * v)));
}
public static double code(double v, double t) {
return (1.0 - (5.0 * Math.exp((Math.log(v) * 2.0)))) / (((Math.PI * t) * Math.sqrt((2.0 * (1.0 - (3.0 * (v * v)))))) * (1.0 - (v * v)));
}
def code(v, t): return (1.0 - (5.0 * math.exp((math.log(v) * 2.0)))) / (((math.pi * t) * math.sqrt((2.0 * (1.0 - (3.0 * (v * v)))))) * (1.0 - (v * v)))
function code(v, t) return Float64(Float64(1.0 - Float64(5.0 * exp(Float64(log(v) * 2.0)))) / Float64(Float64(Float64(pi * t) * sqrt(Float64(2.0 * Float64(1.0 - Float64(3.0 * Float64(v * v)))))) * Float64(1.0 - Float64(v * v)))) end
function tmp = code(v, t) tmp = (1.0 - (5.0 * exp((log(v) * 2.0)))) / (((pi * t) * sqrt((2.0 * (1.0 - (3.0 * (v * v)))))) * (1.0 - (v * v))); end
code[v_, t_] := N[(N[(1.0 - N[(5.0 * N[Exp[N[(N[Log[v], $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(N[(Pi * t), $MachinePrecision] * N[Sqrt[N[(2.0 * N[(1.0 - N[(3.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1 - 5 \cdot e^{\log v \cdot 2}}{\left(\left(\pi \cdot t\right) \cdot \sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)}\right) \cdot \left(1 - v \cdot v\right)}
\end{array}
Initial program 99.3%
lift-*.f64N/A
pow2N/A
pow-to-expN/A
lower-exp.f64N/A
lower-*.f64N/A
lower-log.f6449.2
Applied rewrites49.2%
(FPCore (v t) :precision binary64 (/ (fma (/ (/ (* v v) PI) (sqrt 2.0)) -2.5 (pow (* (sqrt 2.0) PI) -1.0)) t))
double code(double v, double t) {
return fma((((v * v) / ((double) M_PI)) / sqrt(2.0)), -2.5, pow((sqrt(2.0) * ((double) M_PI)), -1.0)) / t;
}
function code(v, t) return Float64(fma(Float64(Float64(Float64(v * v) / pi) / sqrt(2.0)), -2.5, (Float64(sqrt(2.0) * pi) ^ -1.0)) / t) end
code[v_, t_] := N[(N[(N[(N[(N[(v * v), $MachinePrecision] / Pi), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * -2.5 + N[Power[N[(N[Sqrt[2.0], $MachinePrecision] * Pi), $MachinePrecision], -1.0], $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\frac{\frac{v \cdot v}{\pi}}{\sqrt{2}}, -2.5, {\left(\sqrt{2} \cdot \pi\right)}^{-1}\right)}{t}
\end{array}
Initial program 99.3%
Taylor expanded in v around 0
*-commutativeN/A
lower-fma.f64N/A
associate-/r*N/A
lower-/.f64N/A
lower-/.f64N/A
pow2N/A
lift-*.f64N/A
*-commutativeN/A
lower-*.f64N/A
lower-sqrt.f64N/A
lift-PI.f64N/A
inv-powN/A
lower-pow.f64N/A
Applied rewrites98.3%
Taylor expanded in t around 0
lower-/.f64N/A
Applied rewrites98.6%
herbie shell --seed 2025057
(FPCore (v t)
:name "Falkner and Boettcher, Equation (20:1,3)"
:precision binary64
(/ (- 1.0 (* 5.0 (* v v))) (* (* (* PI t) (sqrt (* 2.0 (- 1.0 (* 3.0 (* v v)))))) (- 1.0 (* v v)))))