Trigonometry B

Percentage Accurate: 99.5% → 99.5%
Time: 10.8s
Alternatives: 5
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ \begin{array}{l} t_0 := \tan x \cdot \tan x\\ \frac{1 - t_0}{1 + t_0} \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (* (tan x) (tan x)))) (/ (- 1.0 t_0) (+ 1.0 t_0))))
double code(double x) {
	double t_0 = tan(x) * tan(x);
	return (1.0 - t_0) / (1.0 + t_0);
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    t_0 = tan(x) * tan(x)
    code = (1.0d0 - t_0) / (1.0d0 + t_0)
end function
public static double code(double x) {
	double t_0 = Math.tan(x) * Math.tan(x);
	return (1.0 - t_0) / (1.0 + t_0);
}
def code(x):
	t_0 = math.tan(x) * math.tan(x)
	return (1.0 - t_0) / (1.0 + t_0)
function code(x)
	t_0 = Float64(tan(x) * tan(x))
	return Float64(Float64(1.0 - t_0) / Float64(1.0 + t_0))
end
function tmp = code(x)
	t_0 = tan(x) * tan(x);
	tmp = (1.0 - t_0) / (1.0 + t_0);
end
code[x_] := Block[{t$95$0 = N[(N[Tan[x], $MachinePrecision] * N[Tan[x], $MachinePrecision]), $MachinePrecision]}, N[(N[(1.0 - t$95$0), $MachinePrecision] / N[(1.0 + t$95$0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \tan x \cdot \tan x\\
\frac{1 - t_0}{1 + t_0}
\end{array}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 5 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 99.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \tan x \cdot \tan x\\ \frac{1 - t_0}{1 + t_0} \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (* (tan x) (tan x)))) (/ (- 1.0 t_0) (+ 1.0 t_0))))
double code(double x) {
	double t_0 = tan(x) * tan(x);
	return (1.0 - t_0) / (1.0 + t_0);
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    t_0 = tan(x) * tan(x)
    code = (1.0d0 - t_0) / (1.0d0 + t_0)
end function
public static double code(double x) {
	double t_0 = Math.tan(x) * Math.tan(x);
	return (1.0 - t_0) / (1.0 + t_0);
}
def code(x):
	t_0 = math.tan(x) * math.tan(x)
	return (1.0 - t_0) / (1.0 + t_0)
function code(x)
	t_0 = Float64(tan(x) * tan(x))
	return Float64(Float64(1.0 - t_0) / Float64(1.0 + t_0))
end
function tmp = code(x)
	t_0 = tan(x) * tan(x);
	tmp = (1.0 - t_0) / (1.0 + t_0);
end
code[x_] := Block[{t$95$0 = N[(N[Tan[x], $MachinePrecision] * N[Tan[x], $MachinePrecision]), $MachinePrecision]}, N[(N[(1.0 - t$95$0), $MachinePrecision] / N[(1.0 + t$95$0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \tan x \cdot \tan x\\
\frac{1 - t_0}{1 + t_0}
\end{array}
\end{array}

Alternative 1: 99.5% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \frac{1 - {\tan x}^{2}}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} \end{array} \]
(FPCore (x)
 :precision binary64
 (/ (- 1.0 (pow (tan x) 2.0)) (fma (tan x) (tan x) 1.0)))
double code(double x) {
	return (1.0 - pow(tan(x), 2.0)) / fma(tan(x), tan(x), 1.0);
}
function code(x)
	return Float64(Float64(1.0 - (tan(x) ^ 2.0)) / fma(tan(x), tan(x), 1.0))
end
code[x_] := N[(N[(1.0 - N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision] / N[(N[Tan[x], $MachinePrecision] * N[Tan[x], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1 - {\tan x}^{2}}{\mathsf{fma}\left(\tan x, \tan x, 1\right)}
\end{array}
Derivation
  1. Initial program 99.6%

    \[\frac{1 - \tan x \cdot \tan x}{1 + \tan x \cdot \tan x} \]
  2. Step-by-step derivation
    1. +-commutative99.6%

      \[\leadsto \frac{1 - \tan x \cdot \tan x}{\color{blue}{\tan x \cdot \tan x + 1}} \]
    2. fma-def99.6%

      \[\leadsto \frac{1 - \tan x \cdot \tan x}{\color{blue}{\mathsf{fma}\left(\tan x, \tan x, 1\right)}} \]
  3. Simplified99.6%

    \[\leadsto \color{blue}{\frac{1 - \tan x \cdot \tan x}{\mathsf{fma}\left(\tan x, \tan x, 1\right)}} \]
  4. Step-by-step derivation
    1. add-log-exp98.3%

      \[\leadsto \frac{1 - \color{blue}{\log \left(e^{\tan x \cdot \tan x}\right)}}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} \]
    2. *-un-lft-identity98.3%

      \[\leadsto \frac{1 - \log \color{blue}{\left(1 \cdot e^{\tan x \cdot \tan x}\right)}}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} \]
    3. log-prod98.3%

      \[\leadsto \frac{1 - \color{blue}{\left(\log 1 + \log \left(e^{\tan x \cdot \tan x}\right)\right)}}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} \]
    4. metadata-eval98.3%

      \[\leadsto \frac{1 - \left(\color{blue}{0} + \log \left(e^{\tan x \cdot \tan x}\right)\right)}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} \]
    5. add-log-exp99.6%

      \[\leadsto \frac{1 - \left(0 + \color{blue}{\tan x \cdot \tan x}\right)}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} \]
    6. pow299.6%

      \[\leadsto \frac{1 - \left(0 + \color{blue}{{\tan x}^{2}}\right)}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} \]
  5. Applied egg-rr99.6%

    \[\leadsto \frac{1 - \color{blue}{\left(0 + {\tan x}^{2}\right)}}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} \]
  6. Step-by-step derivation
    1. +-lft-identity99.6%

      \[\leadsto \frac{1 - \color{blue}{{\tan x}^{2}}}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} \]
  7. Simplified99.6%

    \[\leadsto \frac{1 - \color{blue}{{\tan x}^{2}}}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} \]
  8. Final simplification99.6%

    \[\leadsto \frac{1 - {\tan x}^{2}}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} \]

Alternative 2: 57.1% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\tan x \cdot \tan x \leq 1.25:\\ \;\;\;\;\frac{-1}{-1 - {\tan x}^{2}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1 - x \cdot x}{1 + x \cdot x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= (* (tan x) (tan x)) 1.25)
   (/ -1.0 (- -1.0 (pow (tan x) 2.0)))
   (/ (- 1.0 (* x x)) (+ 1.0 (* x x)))))
double code(double x) {
	double tmp;
	if ((tan(x) * tan(x)) <= 1.25) {
		tmp = -1.0 / (-1.0 - pow(tan(x), 2.0));
	} else {
		tmp = (1.0 - (x * x)) / (1.0 + (x * x));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if ((tan(x) * tan(x)) <= 1.25d0) then
        tmp = (-1.0d0) / ((-1.0d0) - (tan(x) ** 2.0d0))
    else
        tmp = (1.0d0 - (x * x)) / (1.0d0 + (x * x))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if ((Math.tan(x) * Math.tan(x)) <= 1.25) {
		tmp = -1.0 / (-1.0 - Math.pow(Math.tan(x), 2.0));
	} else {
		tmp = (1.0 - (x * x)) / (1.0 + (x * x));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if (math.tan(x) * math.tan(x)) <= 1.25:
		tmp = -1.0 / (-1.0 - math.pow(math.tan(x), 2.0))
	else:
		tmp = (1.0 - (x * x)) / (1.0 + (x * x))
	return tmp
function code(x)
	tmp = 0.0
	if (Float64(tan(x) * tan(x)) <= 1.25)
		tmp = Float64(-1.0 / Float64(-1.0 - (tan(x) ^ 2.0)));
	else
		tmp = Float64(Float64(1.0 - Float64(x * x)) / Float64(1.0 + Float64(x * x)));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if ((tan(x) * tan(x)) <= 1.25)
		tmp = -1.0 / (-1.0 - (tan(x) ^ 2.0));
	else
		tmp = (1.0 - (x * x)) / (1.0 + (x * x));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[N[(N[Tan[x], $MachinePrecision] * N[Tan[x], $MachinePrecision]), $MachinePrecision], 1.25], N[(-1.0 / N[(-1.0 - N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 - N[(x * x), $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\tan x \cdot \tan x \leq 1.25:\\
\;\;\;\;\frac{-1}{-1 - {\tan x}^{2}}\\

\mathbf{else}:\\
\;\;\;\;\frac{1 - x \cdot x}{1 + x \cdot x}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (*.f64 (tan.f64 x) (tan.f64 x)) < 1.25

    1. Initial program 99.7%

      \[\frac{1 - \tan x \cdot \tan x}{1 + \tan x \cdot \tan x} \]
    2. Step-by-step derivation
      1. frac-2neg99.7%

        \[\leadsto \color{blue}{\frac{-\left(1 - \tan x \cdot \tan x\right)}{-\left(1 + \tan x \cdot \tan x\right)}} \]
      2. div-inv99.6%

        \[\leadsto \color{blue}{\left(-\left(1 - \tan x \cdot \tan x\right)\right) \cdot \frac{1}{-\left(1 + \tan x \cdot \tan x\right)}} \]
      3. pow299.6%

        \[\leadsto \left(-\left(1 - \color{blue}{{\tan x}^{2}}\right)\right) \cdot \frac{1}{-\left(1 + \tan x \cdot \tan x\right)} \]
      4. +-commutative99.6%

        \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{-\color{blue}{\left(\tan x \cdot \tan x + 1\right)}} \]
      5. distribute-neg-in99.6%

        \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{\color{blue}{\left(-\tan x \cdot \tan x\right) + \left(-1\right)}} \]
      6. neg-mul-199.6%

        \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{\color{blue}{-1 \cdot \left(\tan x \cdot \tan x\right)} + \left(-1\right)} \]
      7. metadata-eval99.6%

        \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{-1 \cdot \left(\tan x \cdot \tan x\right) + \color{blue}{-1}} \]
      8. fma-def99.6%

        \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{\color{blue}{\mathsf{fma}\left(-1, \tan x \cdot \tan x, -1\right)}} \]
      9. pow299.6%

        \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{\mathsf{fma}\left(-1, \color{blue}{{\tan x}^{2}}, -1\right)} \]
    3. Applied egg-rr99.6%

      \[\leadsto \color{blue}{\left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)}} \]
    4. Step-by-step derivation
      1. associate-*r/99.7%

        \[\leadsto \color{blue}{\frac{\left(-\left(1 - {\tan x}^{2}\right)\right) \cdot 1}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)}} \]
      2. *-rgt-identity99.7%

        \[\leadsto \frac{\color{blue}{-\left(1 - {\tan x}^{2}\right)}}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
      3. neg-sub099.7%

        \[\leadsto \frac{\color{blue}{0 - \left(1 - {\tan x}^{2}\right)}}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
      4. associate--r-99.7%

        \[\leadsto \frac{\color{blue}{\left(0 - 1\right) + {\tan x}^{2}}}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
      5. metadata-eval99.7%

        \[\leadsto \frac{\color{blue}{-1} + {\tan x}^{2}}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
      6. fma-udef99.7%

        \[\leadsto \frac{-1 + {\tan x}^{2}}{\color{blue}{-1 \cdot {\tan x}^{2} + -1}} \]
      7. neg-mul-199.7%

        \[\leadsto \frac{-1 + {\tan x}^{2}}{\color{blue}{\left(-{\tan x}^{2}\right)} + -1} \]
      8. +-commutative99.7%

        \[\leadsto \frac{-1 + {\tan x}^{2}}{\color{blue}{-1 + \left(-{\tan x}^{2}\right)}} \]
      9. unsub-neg99.7%

        \[\leadsto \frac{-1 + {\tan x}^{2}}{\color{blue}{-1 - {\tan x}^{2}}} \]
    5. Simplified99.7%

      \[\leadsto \color{blue}{\frac{-1 + {\tan x}^{2}}{-1 - {\tan x}^{2}}} \]
    6. Taylor expanded in x around 0 74.8%

      \[\leadsto \frac{\color{blue}{-1}}{-1 - {\tan x}^{2}} \]

    if 1.25 < (*.f64 (tan.f64 x) (tan.f64 x))

    1. Initial program 99.2%

      \[\frac{1 - \tan x \cdot \tan x}{1 + \tan x \cdot \tan x} \]
    2. Step-by-step derivation
      1. add-cbrt-cube98.7%

        \[\leadsto \frac{1 - \tan x \cdot \tan x}{\color{blue}{\sqrt[3]{\left(\left(1 + \tan x \cdot \tan x\right) \cdot \left(1 + \tan x \cdot \tan x\right)\right) \cdot \left(1 + \tan x \cdot \tan x\right)}}} \]
      2. pow1/398.3%

        \[\leadsto \frac{1 - \tan x \cdot \tan x}{\color{blue}{{\left(\left(\left(1 + \tan x \cdot \tan x\right) \cdot \left(1 + \tan x \cdot \tan x\right)\right) \cdot \left(1 + \tan x \cdot \tan x\right)\right)}^{0.3333333333333333}}} \]
      3. pow398.2%

        \[\leadsto \frac{1 - \tan x \cdot \tan x}{{\color{blue}{\left({\left(1 + \tan x \cdot \tan x\right)}^{3}\right)}}^{0.3333333333333333}} \]
      4. add-sqr-sqrt98.2%

        \[\leadsto \frac{1 - \tan x \cdot \tan x}{{\left({\color{blue}{\left(\sqrt{1 + \tan x \cdot \tan x} \cdot \sqrt{1 + \tan x \cdot \tan x}\right)}}^{3}\right)}^{0.3333333333333333}} \]
      5. pow298.2%

        \[\leadsto \frac{1 - \tan x \cdot \tan x}{{\left({\color{blue}{\left({\left(\sqrt{1 + \tan x \cdot \tan x}\right)}^{2}\right)}}^{3}\right)}^{0.3333333333333333}} \]
      6. pow-pow98.4%

        \[\leadsto \frac{1 - \tan x \cdot \tan x}{{\color{blue}{\left({\left(\sqrt{1 + \tan x \cdot \tan x}\right)}^{\left(2 \cdot 3\right)}\right)}}^{0.3333333333333333}} \]
      7. hypot-1-def98.3%

        \[\leadsto \frac{1 - \tan x \cdot \tan x}{{\left({\color{blue}{\left(\mathsf{hypot}\left(1, \tan x\right)\right)}}^{\left(2 \cdot 3\right)}\right)}^{0.3333333333333333}} \]
      8. metadata-eval98.3%

        \[\leadsto \frac{1 - \tan x \cdot \tan x}{{\left({\left(\mathsf{hypot}\left(1, \tan x\right)\right)}^{\color{blue}{6}}\right)}^{0.3333333333333333}} \]
    3. Applied egg-rr98.3%

      \[\leadsto \frac{1 - \tan x \cdot \tan x}{\color{blue}{{\left({\left(\mathsf{hypot}\left(1, \tan x\right)\right)}^{6}\right)}^{0.3333333333333333}}} \]
    4. Step-by-step derivation
      1. unpow1/398.7%

        \[\leadsto \frac{1 - \tan x \cdot \tan x}{\color{blue}{\sqrt[3]{{\left(\mathsf{hypot}\left(1, \tan x\right)\right)}^{6}}}} \]
    5. Simplified98.7%

      \[\leadsto \frac{1 - \tan x \cdot \tan x}{\color{blue}{\sqrt[3]{{\left(\mathsf{hypot}\left(1, \tan x\right)\right)}^{6}}}} \]
    6. Step-by-step derivation
      1. add-log-exp94.2%

        \[\leadsto \frac{1 - \color{blue}{\log \left(e^{\tan x \cdot \tan x}\right)}}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} \]
      2. *-un-lft-identity94.2%

        \[\leadsto \frac{1 - \log \color{blue}{\left(1 \cdot e^{\tan x \cdot \tan x}\right)}}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} \]
      3. log-prod94.2%

        \[\leadsto \frac{1 - \color{blue}{\left(\log 1 + \log \left(e^{\tan x \cdot \tan x}\right)\right)}}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} \]
      4. metadata-eval94.2%

        \[\leadsto \frac{1 - \left(\color{blue}{0} + \log \left(e^{\tan x \cdot \tan x}\right)\right)}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} \]
      5. add-log-exp99.3%

        \[\leadsto \frac{1 - \left(0 + \color{blue}{\tan x \cdot \tan x}\right)}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} \]
      6. pow299.3%

        \[\leadsto \frac{1 - \left(0 + \color{blue}{{\tan x}^{2}}\right)}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} \]
    7. Applied egg-rr98.7%

      \[\leadsto \frac{1 - \color{blue}{\left(0 + {\tan x}^{2}\right)}}{\sqrt[3]{{\left(\mathsf{hypot}\left(1, \tan x\right)\right)}^{6}}} \]
    8. Step-by-step derivation
      1. +-lft-identity99.3%

        \[\leadsto \frac{1 - \color{blue}{{\tan x}^{2}}}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} \]
    9. Simplified98.7%

      \[\leadsto \frac{1 - \color{blue}{{\tan x}^{2}}}{\sqrt[3]{{\left(\mathsf{hypot}\left(1, \tan x\right)\right)}^{6}}} \]
    10. Taylor expanded in x around 0 4.2%

      \[\leadsto \frac{1 - {\tan x}^{2}}{\color{blue}{1 + {x}^{2}}} \]
    11. Step-by-step derivation
      1. +-commutative4.2%

        \[\leadsto \frac{1 - {\tan x}^{2}}{\color{blue}{{x}^{2} + 1}} \]
      2. unpow24.2%

        \[\leadsto \frac{1 - {\tan x}^{2}}{\color{blue}{x \cdot x} + 1} \]
    12. Simplified4.2%

      \[\leadsto \frac{1 - {\tan x}^{2}}{\color{blue}{x \cdot x + 1}} \]
    13. Taylor expanded in x around 0 8.9%

      \[\leadsto \frac{1 - \color{blue}{{x}^{2}}}{x \cdot x + 1} \]
    14. Step-by-step derivation
      1. unpow28.9%

        \[\leadsto \frac{1 - \color{blue}{x \cdot x}}{x \cdot x + 1} \]
    15. Simplified8.9%

      \[\leadsto \frac{1 - \color{blue}{x \cdot x}}{x \cdot x + 1} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification60.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\tan x \cdot \tan x \leq 1.25:\\ \;\;\;\;\frac{-1}{-1 - {\tan x}^{2}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1 - x \cdot x}{1 + x \cdot x}\\ \end{array} \]

Alternative 3: 99.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := {\tan x}^{2}\\ \frac{t_0 + -1}{-1 - t_0} \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (pow (tan x) 2.0))) (/ (+ t_0 -1.0) (- -1.0 t_0))))
double code(double x) {
	double t_0 = pow(tan(x), 2.0);
	return (t_0 + -1.0) / (-1.0 - t_0);
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    t_0 = tan(x) ** 2.0d0
    code = (t_0 + (-1.0d0)) / ((-1.0d0) - t_0)
end function
public static double code(double x) {
	double t_0 = Math.pow(Math.tan(x), 2.0);
	return (t_0 + -1.0) / (-1.0 - t_0);
}
def code(x):
	t_0 = math.pow(math.tan(x), 2.0)
	return (t_0 + -1.0) / (-1.0 - t_0)
function code(x)
	t_0 = tan(x) ^ 2.0
	return Float64(Float64(t_0 + -1.0) / Float64(-1.0 - t_0))
end
function tmp = code(x)
	t_0 = tan(x) ^ 2.0;
	tmp = (t_0 + -1.0) / (-1.0 - t_0);
end
code[x_] := Block[{t$95$0 = N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]}, N[(N[(t$95$0 + -1.0), $MachinePrecision] / N[(-1.0 - t$95$0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := {\tan x}^{2}\\
\frac{t_0 + -1}{-1 - t_0}
\end{array}
\end{array}
Derivation
  1. Initial program 99.6%

    \[\frac{1 - \tan x \cdot \tan x}{1 + \tan x \cdot \tan x} \]
  2. Step-by-step derivation
    1. frac-2neg99.6%

      \[\leadsto \color{blue}{\frac{-\left(1 - \tan x \cdot \tan x\right)}{-\left(1 + \tan x \cdot \tan x\right)}} \]
    2. div-inv99.5%

      \[\leadsto \color{blue}{\left(-\left(1 - \tan x \cdot \tan x\right)\right) \cdot \frac{1}{-\left(1 + \tan x \cdot \tan x\right)}} \]
    3. pow299.5%

      \[\leadsto \left(-\left(1 - \color{blue}{{\tan x}^{2}}\right)\right) \cdot \frac{1}{-\left(1 + \tan x \cdot \tan x\right)} \]
    4. +-commutative99.5%

      \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{-\color{blue}{\left(\tan x \cdot \tan x + 1\right)}} \]
    5. distribute-neg-in99.5%

      \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{\color{blue}{\left(-\tan x \cdot \tan x\right) + \left(-1\right)}} \]
    6. neg-mul-199.5%

      \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{\color{blue}{-1 \cdot \left(\tan x \cdot \tan x\right)} + \left(-1\right)} \]
    7. metadata-eval99.5%

      \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{-1 \cdot \left(\tan x \cdot \tan x\right) + \color{blue}{-1}} \]
    8. fma-def99.5%

      \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{\color{blue}{\mathsf{fma}\left(-1, \tan x \cdot \tan x, -1\right)}} \]
    9. pow299.5%

      \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{\mathsf{fma}\left(-1, \color{blue}{{\tan x}^{2}}, -1\right)} \]
  3. Applied egg-rr99.5%

    \[\leadsto \color{blue}{\left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)}} \]
  4. Step-by-step derivation
    1. associate-*r/99.6%

      \[\leadsto \color{blue}{\frac{\left(-\left(1 - {\tan x}^{2}\right)\right) \cdot 1}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)}} \]
    2. *-rgt-identity99.6%

      \[\leadsto \frac{\color{blue}{-\left(1 - {\tan x}^{2}\right)}}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
    3. neg-sub099.6%

      \[\leadsto \frac{\color{blue}{0 - \left(1 - {\tan x}^{2}\right)}}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
    4. associate--r-99.6%

      \[\leadsto \frac{\color{blue}{\left(0 - 1\right) + {\tan x}^{2}}}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
    5. metadata-eval99.6%

      \[\leadsto \frac{\color{blue}{-1} + {\tan x}^{2}}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
    6. fma-udef99.6%

      \[\leadsto \frac{-1 + {\tan x}^{2}}{\color{blue}{-1 \cdot {\tan x}^{2} + -1}} \]
    7. neg-mul-199.6%

      \[\leadsto \frac{-1 + {\tan x}^{2}}{\color{blue}{\left(-{\tan x}^{2}\right)} + -1} \]
    8. +-commutative99.6%

      \[\leadsto \frac{-1 + {\tan x}^{2}}{\color{blue}{-1 + \left(-{\tan x}^{2}\right)}} \]
    9. unsub-neg99.6%

      \[\leadsto \frac{-1 + {\tan x}^{2}}{\color{blue}{-1 - {\tan x}^{2}}} \]
  5. Simplified99.6%

    \[\leadsto \color{blue}{\frac{-1 + {\tan x}^{2}}{-1 - {\tan x}^{2}}} \]
  6. Final simplification99.6%

    \[\leadsto \frac{{\tan x}^{2} + -1}{-1 - {\tan x}^{2}} \]

Alternative 4: 58.0% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \frac{1}{1 - {\tan x}^{4}} \end{array} \]
(FPCore (x) :precision binary64 (/ 1.0 (- 1.0 (pow (tan x) 4.0))))
double code(double x) {
	return 1.0 / (1.0 - pow(tan(x), 4.0));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 1.0d0 / (1.0d0 - (tan(x) ** 4.0d0))
end function
public static double code(double x) {
	return 1.0 / (1.0 - Math.pow(Math.tan(x), 4.0));
}
def code(x):
	return 1.0 / (1.0 - math.pow(math.tan(x), 4.0))
function code(x)
	return Float64(1.0 / Float64(1.0 - (tan(x) ^ 4.0)))
end
function tmp = code(x)
	tmp = 1.0 / (1.0 - (tan(x) ^ 4.0));
end
code[x_] := N[(1.0 / N[(1.0 - N[Power[N[Tan[x], $MachinePrecision], 4.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{1 - {\tan x}^{4}}
\end{array}
Derivation
  1. Initial program 99.6%

    \[\frac{1 - \tan x \cdot \tan x}{1 + \tan x \cdot \tan x} \]
  2. Step-by-step derivation
    1. flip-+99.6%

      \[\leadsto \frac{1 - \tan x \cdot \tan x}{\color{blue}{\frac{1 \cdot 1 - \left(\tan x \cdot \tan x\right) \cdot \left(\tan x \cdot \tan x\right)}{1 - \tan x \cdot \tan x}}} \]
    2. associate-/r/99.5%

      \[\leadsto \color{blue}{\frac{1 - \tan x \cdot \tan x}{1 \cdot 1 - \left(\tan x \cdot \tan x\right) \cdot \left(\tan x \cdot \tan x\right)} \cdot \left(1 - \tan x \cdot \tan x\right)} \]
    3. pow299.5%

      \[\leadsto \frac{1 - \color{blue}{{\tan x}^{2}}}{1 \cdot 1 - \left(\tan x \cdot \tan x\right) \cdot \left(\tan x \cdot \tan x\right)} \cdot \left(1 - \tan x \cdot \tan x\right) \]
    4. metadata-eval99.5%

      \[\leadsto \frac{1 - {\tan x}^{2}}{\color{blue}{1} - \left(\tan x \cdot \tan x\right) \cdot \left(\tan x \cdot \tan x\right)} \cdot \left(1 - \tan x \cdot \tan x\right) \]
    5. pow299.5%

      \[\leadsto \frac{1 - {\tan x}^{2}}{1 - \color{blue}{{\tan x}^{2}} \cdot \left(\tan x \cdot \tan x\right)} \cdot \left(1 - \tan x \cdot \tan x\right) \]
    6. pow299.5%

      \[\leadsto \frac{1 - {\tan x}^{2}}{1 - {\tan x}^{2} \cdot \color{blue}{{\tan x}^{2}}} \cdot \left(1 - \tan x \cdot \tan x\right) \]
    7. pow-prod-up99.4%

      \[\leadsto \frac{1 - {\tan x}^{2}}{1 - \color{blue}{{\tan x}^{\left(2 + 2\right)}}} \cdot \left(1 - \tan x \cdot \tan x\right) \]
    8. metadata-eval99.4%

      \[\leadsto \frac{1 - {\tan x}^{2}}{1 - {\tan x}^{\color{blue}{4}}} \cdot \left(1 - \tan x \cdot \tan x\right) \]
    9. pow299.4%

      \[\leadsto \frac{1 - {\tan x}^{2}}{1 - {\tan x}^{4}} \cdot \left(1 - \color{blue}{{\tan x}^{2}}\right) \]
  3. Applied egg-rr99.4%

    \[\leadsto \color{blue}{\frac{1 - {\tan x}^{2}}{1 - {\tan x}^{4}} \cdot \left(1 - {\tan x}^{2}\right)} \]
  4. Step-by-step derivation
    1. associate-*l/99.4%

      \[\leadsto \color{blue}{\frac{\left(1 - {\tan x}^{2}\right) \cdot \left(1 - {\tan x}^{2}\right)}{1 - {\tan x}^{4}}} \]
    2. unpow299.4%

      \[\leadsto \frac{\color{blue}{{\left(1 - {\tan x}^{2}\right)}^{2}}}{1 - {\tan x}^{4}} \]
  5. Simplified99.4%

    \[\leadsto \color{blue}{\frac{{\left(1 - {\tan x}^{2}\right)}^{2}}{1 - {\tan x}^{4}}} \]
  6. Taylor expanded in x around 0 61.3%

    \[\leadsto \frac{{\color{blue}{1}}^{2}}{1 - {\tan x}^{4}} \]
  7. Final simplification61.3%

    \[\leadsto \frac{1}{1 - {\tan x}^{4}} \]

Alternative 5: 54.6% accurate, 411.0× speedup?

\[\begin{array}{l} \\ 1 \end{array} \]
(FPCore (x) :precision binary64 1.0)
double code(double x) {
	return 1.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 1.0d0
end function
public static double code(double x) {
	return 1.0;
}
def code(x):
	return 1.0
function code(x)
	return 1.0
end
function tmp = code(x)
	tmp = 1.0;
end
code[x_] := 1.0
\begin{array}{l}

\\
1
\end{array}
Derivation
  1. Initial program 99.6%

    \[\frac{1 - \tan x \cdot \tan x}{1 + \tan x \cdot \tan x} \]
  2. Step-by-step derivation
    1. frac-2neg99.6%

      \[\leadsto \color{blue}{\frac{-\left(1 - \tan x \cdot \tan x\right)}{-\left(1 + \tan x \cdot \tan x\right)}} \]
    2. div-inv99.5%

      \[\leadsto \color{blue}{\left(-\left(1 - \tan x \cdot \tan x\right)\right) \cdot \frac{1}{-\left(1 + \tan x \cdot \tan x\right)}} \]
    3. pow299.5%

      \[\leadsto \left(-\left(1 - \color{blue}{{\tan x}^{2}}\right)\right) \cdot \frac{1}{-\left(1 + \tan x \cdot \tan x\right)} \]
    4. +-commutative99.5%

      \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{-\color{blue}{\left(\tan x \cdot \tan x + 1\right)}} \]
    5. distribute-neg-in99.5%

      \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{\color{blue}{\left(-\tan x \cdot \tan x\right) + \left(-1\right)}} \]
    6. neg-mul-199.5%

      \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{\color{blue}{-1 \cdot \left(\tan x \cdot \tan x\right)} + \left(-1\right)} \]
    7. metadata-eval99.5%

      \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{-1 \cdot \left(\tan x \cdot \tan x\right) + \color{blue}{-1}} \]
    8. fma-def99.5%

      \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{\color{blue}{\mathsf{fma}\left(-1, \tan x \cdot \tan x, -1\right)}} \]
    9. pow299.5%

      \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{\mathsf{fma}\left(-1, \color{blue}{{\tan x}^{2}}, -1\right)} \]
  3. Applied egg-rr99.5%

    \[\leadsto \color{blue}{\left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)}} \]
  4. Step-by-step derivation
    1. associate-*r/99.6%

      \[\leadsto \color{blue}{\frac{\left(-\left(1 - {\tan x}^{2}\right)\right) \cdot 1}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)}} \]
    2. *-rgt-identity99.6%

      \[\leadsto \frac{\color{blue}{-\left(1 - {\tan x}^{2}\right)}}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
    3. neg-sub099.6%

      \[\leadsto \frac{\color{blue}{0 - \left(1 - {\tan x}^{2}\right)}}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
    4. associate--r-99.6%

      \[\leadsto \frac{\color{blue}{\left(0 - 1\right) + {\tan x}^{2}}}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
    5. metadata-eval99.6%

      \[\leadsto \frac{\color{blue}{-1} + {\tan x}^{2}}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
    6. fma-udef99.6%

      \[\leadsto \frac{-1 + {\tan x}^{2}}{\color{blue}{-1 \cdot {\tan x}^{2} + -1}} \]
    7. neg-mul-199.6%

      \[\leadsto \frac{-1 + {\tan x}^{2}}{\color{blue}{\left(-{\tan x}^{2}\right)} + -1} \]
    8. +-commutative99.6%

      \[\leadsto \frac{-1 + {\tan x}^{2}}{\color{blue}{-1 + \left(-{\tan x}^{2}\right)}} \]
    9. unsub-neg99.6%

      \[\leadsto \frac{-1 + {\tan x}^{2}}{\color{blue}{-1 - {\tan x}^{2}}} \]
  5. Simplified99.6%

    \[\leadsto \color{blue}{\frac{-1 + {\tan x}^{2}}{-1 - {\tan x}^{2}}} \]
  6. Step-by-step derivation
    1. add-cbrt-cube99.4%

      \[\leadsto \frac{-1 + \color{blue}{\sqrt[3]{\left({\tan x}^{2} \cdot {\tan x}^{2}\right) \cdot {\tan x}^{2}}}}{-1 - {\tan x}^{2}} \]
    2. pow399.4%

      \[\leadsto \frac{-1 + \sqrt[3]{\color{blue}{{\left({\tan x}^{2}\right)}^{3}}}}{-1 - {\tan x}^{2}} \]
    3. pow-pow99.4%

      \[\leadsto \frac{-1 + \sqrt[3]{\color{blue}{{\tan x}^{\left(2 \cdot 3\right)}}}}{-1 - {\tan x}^{2}} \]
    4. metadata-eval99.4%

      \[\leadsto \frac{-1 + \sqrt[3]{{\tan x}^{\color{blue}{6}}}}{-1 - {\tan x}^{2}} \]
  7. Applied egg-rr99.4%

    \[\leadsto \frac{-1 + \color{blue}{\sqrt[3]{{\tan x}^{6}}}}{-1 - {\tan x}^{2}} \]
  8. Step-by-step derivation
    1. expm1-log1p-u99.3%

      \[\leadsto \frac{\color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(-1 + \sqrt[3]{{\tan x}^{6}}\right)\right)}}{-1 - {\tan x}^{2}} \]
    2. expm1-udef99.3%

      \[\leadsto \frac{\color{blue}{e^{\mathsf{log1p}\left(-1 + \sqrt[3]{{\tan x}^{6}}\right)} - 1}}{-1 - {\tan x}^{2}} \]
    3. +-commutative99.3%

      \[\leadsto \frac{e^{\mathsf{log1p}\left(\color{blue}{\sqrt[3]{{\tan x}^{6}} + -1}\right)} - 1}{-1 - {\tan x}^{2}} \]
    4. pow1/399.4%

      \[\leadsto \frac{e^{\mathsf{log1p}\left(\color{blue}{{\left({\tan x}^{6}\right)}^{0.3333333333333333}} + -1\right)} - 1}{-1 - {\tan x}^{2}} \]
    5. pow-pow99.4%

      \[\leadsto \frac{e^{\mathsf{log1p}\left(\color{blue}{{\tan x}^{\left(6 \cdot 0.3333333333333333\right)}} + -1\right)} - 1}{-1 - {\tan x}^{2}} \]
    6. metadata-eval99.4%

      \[\leadsto \frac{e^{\mathsf{log1p}\left({\tan x}^{\color{blue}{2}} + -1\right)} - 1}{-1 - {\tan x}^{2}} \]
  9. Applied egg-rr99.4%

    \[\leadsto \frac{\color{blue}{e^{\mathsf{log1p}\left({\tan x}^{2} + -1\right)} - 1}}{-1 - {\tan x}^{2}} \]
  10. Step-by-step derivation
    1. expm1-def99.4%

      \[\leadsto \frac{\color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left({\tan x}^{2} + -1\right)\right)}}{-1 - {\tan x}^{2}} \]
    2. expm1-log1p99.6%

      \[\leadsto \frac{\color{blue}{{\tan x}^{2} + -1}}{-1 - {\tan x}^{2}} \]
    3. unpow299.6%

      \[\leadsto \frac{\color{blue}{\tan x \cdot \tan x} + -1}{-1 - {\tan x}^{2}} \]
    4. fma-udef99.6%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\tan x, \tan x, -1\right)}}{-1 - {\tan x}^{2}} \]
  11. Simplified99.6%

    \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\tan x, \tan x, -1\right)}}{-1 - {\tan x}^{2}} \]
  12. Taylor expanded in x around 0 58.2%

    \[\leadsto \color{blue}{1} \]
  13. Final simplification58.2%

    \[\leadsto 1 \]

Reproduce

?
herbie shell --seed 2023227 
(FPCore (x)
  :name "Trigonometry B"
  :precision binary64
  (/ (- 1.0 (* (tan x) (tan x))) (+ 1.0 (* (tan x) (tan x)))))