
(FPCore (x) :precision binary64 (- (cbrt (+ x 1.0)) (cbrt x)))
double code(double x) {
return cbrt((x + 1.0)) - cbrt(x);
}
public static double code(double x) {
return Math.cbrt((x + 1.0)) - Math.cbrt(x);
}
function code(x) return Float64(cbrt(Float64(x + 1.0)) - cbrt(x)) end
code[x_] := N[(N[Power[N[(x + 1.0), $MachinePrecision], 1/3], $MachinePrecision] - N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\sqrt[3]{x + 1} - \sqrt[3]{x}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 4 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (- (cbrt (+ x 1.0)) (cbrt x)))
double code(double x) {
return cbrt((x + 1.0)) - cbrt(x);
}
public static double code(double x) {
return Math.cbrt((x + 1.0)) - Math.cbrt(x);
}
function code(x) return Float64(cbrt(Float64(x + 1.0)) - cbrt(x)) end
code[x_] := N[(N[Power[N[(x + 1.0), $MachinePrecision], 1/3], $MachinePrecision] - N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\sqrt[3]{x + 1} - \sqrt[3]{x}
\end{array}
(FPCore (x) :precision binary64 (* (/ (cbrt x) x) 0.3333333333333333))
double code(double x) {
return (cbrt(x) / x) * 0.3333333333333333;
}
public static double code(double x) {
return (Math.cbrt(x) / x) * 0.3333333333333333;
}
function code(x) return Float64(Float64(cbrt(x) / x) * 0.3333333333333333) end
code[x_] := N[(N[(N[Power[x, 1/3], $MachinePrecision] / x), $MachinePrecision] * 0.3333333333333333), $MachinePrecision]
\begin{array}{l}
\\
\frac{\sqrt[3]{x}}{x} \cdot 0.3333333333333333
\end{array}
Initial program 5.3%
Taylor expanded in x around inf
*-lowering-*.f64N/A
metadata-evalN/A
associate-*r/N/A
cbrt-lowering-cbrt.f64N/A
associate-*r/N/A
metadata-evalN/A
/-lowering-/.f64N/A
unpow2N/A
*-lowering-*.f6448.1%
Simplified48.1%
*-commutativeN/A
*-lowering-*.f64N/A
cbrt-divN/A
metadata-evalN/A
pow1/3N/A
pow-flipN/A
pow2N/A
pow-powN/A
pow-lowering-pow.f64N/A
metadata-evalN/A
metadata-eval89.8%
Applied egg-rr89.8%
metadata-evalN/A
metadata-evalN/A
pow-powN/A
inv-powN/A
pow-powN/A
pow2N/A
un-div-invN/A
frac-2negN/A
pow1/3N/A
cbrt-undivN/A
clear-numN/A
inv-powN/A
pow-to-expN/A
exp-lowering-exp.f64N/A
cbrt-undivN/A
frac-2negN/A
div-invN/A
remove-double-divN/A
cbrt-unprodN/A
*-lowering-*.f64N/A
Applied egg-rr90.4%
exp-to-powN/A
inv-powN/A
metadata-evalN/A
metadata-evalN/A
pow-divN/A
pow2N/A
pow-powN/A
pow1/3N/A
clear-numN/A
associate-/r*N/A
div-invN/A
pow1/3N/A
pow-powN/A
inv-powN/A
pow-prod-upN/A
metadata-evalN/A
metadata-evalN/A
metadata-evalN/A
/-lowering-/.f64N/A
metadata-evalN/A
unpow1/3N/A
cbrt-lowering-cbrt.f6498.5%
Applied egg-rr98.5%
(FPCore (x) :precision binary64 (* (cbrt x) (/ 0.3333333333333333 x)))
double code(double x) {
return cbrt(x) * (0.3333333333333333 / x);
}
public static double code(double x) {
return Math.cbrt(x) * (0.3333333333333333 / x);
}
function code(x) return Float64(cbrt(x) * Float64(0.3333333333333333 / x)) end
code[x_] := N[(N[Power[x, 1/3], $MachinePrecision] * N[(0.3333333333333333 / x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\sqrt[3]{x} \cdot \frac{0.3333333333333333}{x}
\end{array}
Initial program 5.3%
Taylor expanded in x around inf
*-lowering-*.f64N/A
metadata-evalN/A
associate-*r/N/A
cbrt-lowering-cbrt.f64N/A
associate-*r/N/A
metadata-evalN/A
/-lowering-/.f64N/A
unpow2N/A
*-lowering-*.f6448.1%
Simplified48.1%
associate-/r*N/A
frac-2negN/A
cbrt-divN/A
/-lowering-/.f64N/A
cbrt-lowering-cbrt.f64N/A
neg-lowering-neg.f64N/A
/-lowering-/.f64N/A
cbrt-lowering-cbrt.f64N/A
neg-lowering-neg.f6497.8%
Applied egg-rr97.8%
inv-powN/A
rem-cube-cbrtN/A
sqr-powN/A
unpow-prod-downN/A
*-lowering-*.f64N/A
pow-lowering-pow.f64N/A
pow1/3N/A
pow-powN/A
metadata-evalN/A
metadata-evalN/A
metadata-evalN/A
metadata-evalN/A
pow-lowering-pow.f64N/A
metadata-evalN/A
metadata-evalN/A
pow-lowering-pow.f64N/A
Applied egg-rr97.8%
cbrt-undivN/A
pow1/3N/A
frac-2negN/A
div-invN/A
pow-prod-upN/A
pow-powN/A
metadata-evalN/A
metadata-evalN/A
inv-powN/A
unpow-prod-downN/A
unpow-prod-downN/A
pow-prod-upN/A
pow-powN/A
metadata-evalN/A
metadata-evalN/A
metadata-evalN/A
metadata-evalN/A
pow-divN/A
pow-powN/A
pow1/3N/A
pow2N/A
div-invN/A
Applied egg-rr98.4%
Final simplification98.4%
(FPCore (x) :precision binary64 (* 0.3333333333333333 (pow x -0.6666666666666666)))
double code(double x) {
return 0.3333333333333333 * pow(x, -0.6666666666666666);
}
real(8) function code(x)
real(8), intent (in) :: x
code = 0.3333333333333333d0 * (x ** (-0.6666666666666666d0))
end function
public static double code(double x) {
return 0.3333333333333333 * Math.pow(x, -0.6666666666666666);
}
def code(x): return 0.3333333333333333 * math.pow(x, -0.6666666666666666)
function code(x) return Float64(0.3333333333333333 * (x ^ -0.6666666666666666)) end
function tmp = code(x) tmp = 0.3333333333333333 * (x ^ -0.6666666666666666); end
code[x_] := N[(0.3333333333333333 * N[Power[x, -0.6666666666666666], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.3333333333333333 \cdot {x}^{-0.6666666666666666}
\end{array}
Initial program 5.3%
Taylor expanded in x around inf
*-lowering-*.f64N/A
metadata-evalN/A
associate-*r/N/A
cbrt-lowering-cbrt.f64N/A
associate-*r/N/A
metadata-evalN/A
/-lowering-/.f64N/A
unpow2N/A
*-lowering-*.f6448.1%
Simplified48.1%
*-commutativeN/A
*-lowering-*.f64N/A
cbrt-divN/A
metadata-evalN/A
pow1/3N/A
pow-flipN/A
pow2N/A
pow-powN/A
pow-lowering-pow.f64N/A
metadata-evalN/A
metadata-eval89.8%
Applied egg-rr89.8%
Final simplification89.8%
(FPCore (x) :precision binary64 (- 1.0 (cbrt x)))
double code(double x) {
return 1.0 - cbrt(x);
}
public static double code(double x) {
return 1.0 - Math.cbrt(x);
}
function code(x) return Float64(1.0 - cbrt(x)) end
code[x_] := N[(1.0 - N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
1 - \sqrt[3]{x}
\end{array}
Initial program 5.3%
Taylor expanded in x around 0
--lowering--.f64N/A
cbrt-lowering-cbrt.f641.8%
Simplified1.8%
(FPCore (x) :precision binary64 (let* ((t_0 (cbrt (+ x 1.0)))) (/ 1.0 (+ (+ (* t_0 t_0) (* (cbrt x) t_0)) (* (cbrt x) (cbrt x))))))
double code(double x) {
double t_0 = cbrt((x + 1.0));
return 1.0 / (((t_0 * t_0) + (cbrt(x) * t_0)) + (cbrt(x) * cbrt(x)));
}
public static double code(double x) {
double t_0 = Math.cbrt((x + 1.0));
return 1.0 / (((t_0 * t_0) + (Math.cbrt(x) * t_0)) + (Math.cbrt(x) * Math.cbrt(x)));
}
function code(x) t_0 = cbrt(Float64(x + 1.0)) return Float64(1.0 / Float64(Float64(Float64(t_0 * t_0) + Float64(cbrt(x) * t_0)) + Float64(cbrt(x) * cbrt(x)))) end
code[x_] := Block[{t$95$0 = N[Power[N[(x + 1.0), $MachinePrecision], 1/3], $MachinePrecision]}, N[(1.0 / N[(N[(N[(t$95$0 * t$95$0), $MachinePrecision] + N[(N[Power[x, 1/3], $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision] + N[(N[Power[x, 1/3], $MachinePrecision] * N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt[3]{x + 1}\\
\frac{1}{\left(t\_0 \cdot t\_0 + \sqrt[3]{x} \cdot t\_0\right) + \sqrt[3]{x} \cdot \sqrt[3]{x}}
\end{array}
\end{array}
herbie shell --seed 2024140
(FPCore (x)
:name "2cbrt (problem 3.3.4)"
:precision binary64
:pre (and (> x 1.0) (< x 1e+308))
:alt
(! :herbie-platform default (/ 1 (+ (* (cbrt (+ x 1)) (cbrt (+ x 1))) (* (cbrt x) (cbrt (+ x 1))) (* (cbrt x) (cbrt x)))))
(- (cbrt (+ x 1.0)) (cbrt x)))