Trigonometry B

Percentage Accurate: 99.5% → 99.5%
Time: 9.9s
Alternatives: 6
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 6 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, 0.7× speedup?

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

\\
\frac{\mathsf{fma}\left(\tan x, -\tan x, 1\right)}{\mathsf{fma}\left(\tan x, \tan x, 1\right)}
\end{array}
Derivation
  1. Initial program 99.5%

    \[\frac{1 - \tan x \cdot \tan x}{1 + \tan x \cdot \tan x} \]
  2. Step-by-step derivation
    1. +-commutative99.5%

      \[\leadsto \frac{1 - \tan x \cdot \tan x}{\color{blue}{\tan x \cdot \tan x + 1}} \]
    2. fma-def99.5%

      \[\leadsto \frac{1 - \tan x \cdot \tan x}{\color{blue}{\mathsf{fma}\left(\tan x, \tan x, 1\right)}} \]
  3. Simplified99.5%

    \[\leadsto \color{blue}{\frac{1 - \tan x \cdot \tan x}{\mathsf{fma}\left(\tan x, \tan x, 1\right)}} \]
  4. Step-by-step derivation
    1. sub-neg99.5%

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

      \[\leadsto \frac{\color{blue}{\left(-\tan x \cdot \tan x\right) + 1}}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} \]
    3. distribute-rgt-neg-in99.5%

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

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

    \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\tan x, -\tan x, 1\right)}}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} \]
  6. Final simplification99.5%

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

Alternative 2: 99.5% accurate, 0.8× speedup?

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

\\
\frac{\mathsf{fma}\left(\tan x, \tan x, -1\right)}{-1 - {\tan x}^{2}}
\end{array}
Derivation
  1. Initial program 99.5%

    \[\frac{1 - \tan x \cdot \tan x}{1 + \tan x \cdot \tan x} \]
  2. Step-by-step derivation
    1. frac-2neg99.5%

      \[\leadsto \color{blue}{\frac{-\left(1 - \tan x \cdot \tan x\right)}{-\left(1 + \tan x \cdot \tan x\right)}} \]
    2. div-inv99.4%

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

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

      \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{-\color{blue}{\left(\tan x \cdot \tan x + 1\right)}} \]
    5. distribute-neg-in99.4%

      \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{\color{blue}{\left(-\tan x \cdot \tan x\right) + \left(-1\right)}} \]
    6. neg-mul-199.4%

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

      \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{-1 \cdot \left(\tan x \cdot \tan x\right) + \color{blue}{-1}} \]
    8. fma-def99.4%

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

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

    \[\leadsto \color{blue}{\left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)}} \]
  4. Step-by-step derivation
    1. associate-*r/99.5%

      \[\leadsto \color{blue}{\frac{\left(-\left(1 - {\tan x}^{2}\right)\right) \cdot 1}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)}} \]
    2. *-rgt-identity99.5%

      \[\leadsto \frac{\color{blue}{-\left(1 - {\tan x}^{2}\right)}}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
    3. neg-sub099.5%

      \[\leadsto \frac{\color{blue}{0 - \left(1 - {\tan x}^{2}\right)}}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
    4. associate--r-99.5%

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

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

      \[\leadsto \frac{\color{blue}{{\tan x}^{2} + -1}}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
    7. unpow299.5%

      \[\leadsto \frac{\color{blue}{\tan x \cdot \tan x} + -1}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
    8. fma-udef99.5%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\tan x, \tan x, -1\right)}}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
    9. fma-udef99.5%

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

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

      \[\leadsto \frac{\mathsf{fma}\left(\tan x, \tan x, -1\right)}{\color{blue}{-1 + \left(-{\tan x}^{2}\right)}} \]
    12. unsub-neg99.5%

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

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\tan x, \tan x, -1\right)}{-1 - {\tan x}^{2}}} \]
  6. Final simplification99.5%

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

Alternative 3: 99.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := {\tan x}^{2}\\ \frac{1 - t_0}{1 + t_0} \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (pow (tan x) 2.0))) (/ (- 1.0 t_0) (+ 1.0 t_0))))
double code(double x) {
	double t_0 = pow(tan(x), 2.0);
	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) ** 2.0d0
    code = (1.0d0 - t_0) / (1.0d0 + t_0)
end function
public static double code(double x) {
	double t_0 = Math.pow(Math.tan(x), 2.0);
	return (1.0 - t_0) / (1.0 + t_0);
}
def code(x):
	t_0 = math.pow(math.tan(x), 2.0)
	return (1.0 - t_0) / (1.0 + t_0)
function code(x)
	t_0 = tan(x) ^ 2.0
	return Float64(Float64(1.0 - t_0) / Float64(1.0 + t_0))
end
function tmp = code(x)
	t_0 = tan(x) ^ 2.0;
	tmp = (1.0 - t_0) / (1.0 + t_0);
end
code[x_] := Block[{t$95$0 = N[Power[N[Tan[x], $MachinePrecision], 2.0], $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}^{2}\\
\frac{1 - t_0}{1 + t_0}
\end{array}
\end{array}
Derivation
  1. Initial program 99.5%

    \[\frac{1 - \tan x \cdot \tan x}{1 + \tan x \cdot \tan x} \]
  2. Step-by-step derivation
    1. pow299.5%

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

      \[\leadsto \frac{1 - {\tan x}^{\color{blue}{\left(6 \cdot 0.3333333333333333\right)}}}{1 + \tan x \cdot \tan x} \]
    3. metadata-eval99.5%

      \[\leadsto \frac{1 - {\tan x}^{\left(\color{blue}{\left(2 \cdot 3\right)} \cdot 0.3333333333333333\right)}}{1 + \tan x \cdot \tan x} \]
    4. pow-pow99.2%

      \[\leadsto \frac{1 - \color{blue}{{\left({\tan x}^{\left(2 \cdot 3\right)}\right)}^{0.3333333333333333}}}{1 + \tan x \cdot \tan x} \]
    5. metadata-eval99.2%

      \[\leadsto \frac{1 - {\left({\tan x}^{\color{blue}{6}}\right)}^{0.3333333333333333}}{1 + \tan x \cdot \tan x} \]
  3. Applied egg-rr99.2%

    \[\leadsto \frac{1 - \color{blue}{{\left({\tan x}^{6}\right)}^{0.3333333333333333}}}{1 + \tan x \cdot \tan x} \]
  4. Step-by-step derivation
    1. pow-pow99.5%

      \[\leadsto \frac{1 - \color{blue}{{\tan x}^{\left(6 \cdot 0.3333333333333333\right)}}}{1 + \tan x \cdot \tan x} \]
    2. metadata-eval99.5%

      \[\leadsto \frac{1 - {\tan x}^{\color{blue}{2}}}{1 + \tan x \cdot \tan x} \]
    3. pow299.5%

      \[\leadsto \frac{1 - \color{blue}{\tan x \cdot \tan x}}{1 + \tan x \cdot \tan x} \]
    4. tan-quot99.4%

      \[\leadsto \frac{1 - \tan x \cdot \color{blue}{\frac{\sin x}{\cos x}}}{1 + \tan x \cdot \tan x} \]
    5. associate-*r/99.4%

      \[\leadsto \frac{1 - \color{blue}{\frac{\tan x \cdot \sin x}{\cos x}}}{1 + \tan x \cdot \tan x} \]
    6. expm1-log1p-u99.2%

      \[\leadsto \frac{1 - \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{\tan x \cdot \sin x}{\cos x}\right)\right)}}{1 + \tan x \cdot \tan x} \]
    7. expm1-udef99.0%

      \[\leadsto \frac{1 - \color{blue}{\left(e^{\mathsf{log1p}\left(\frac{\tan x \cdot \sin x}{\cos x}\right)} - 1\right)}}{1 + \tan x \cdot \tan x} \]
    8. log1p-udef99.1%

      \[\leadsto \frac{1 - \left(e^{\color{blue}{\log \left(1 + \frac{\tan x \cdot \sin x}{\cos x}\right)}} - 1\right)}{1 + \tan x \cdot \tan x} \]
    9. add-exp-log99.3%

      \[\leadsto \frac{1 - \left(\color{blue}{\left(1 + \frac{\tan x \cdot \sin x}{\cos x}\right)} - 1\right)}{1 + \tan x \cdot \tan x} \]
    10. associate-*r/99.3%

      \[\leadsto \frac{1 - \left(\left(1 + \color{blue}{\tan x \cdot \frac{\sin x}{\cos x}}\right) - 1\right)}{1 + \tan x \cdot \tan x} \]
    11. tan-quot99.4%

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

      \[\leadsto \frac{1 - \left(\color{blue}{\left(\tan x \cdot \tan x + 1\right)} - 1\right)}{1 + \tan x \cdot \tan x} \]
    13. fma-udef99.4%

      \[\leadsto \frac{1 - \left(\color{blue}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} - 1\right)}{1 + \tan x \cdot \tan x} \]
  5. Applied egg-rr99.4%

    \[\leadsto \frac{1 - \color{blue}{\left(\mathsf{fma}\left(\tan x, \tan x, 1\right) - 1\right)}}{1 + \tan x \cdot \tan x} \]
  6. Step-by-step derivation
    1. sub-neg99.4%

      \[\leadsto \frac{1 - \color{blue}{\left(\mathsf{fma}\left(\tan x, \tan x, 1\right) + \left(-1\right)\right)}}{1 + \tan x \cdot \tan x} \]
    2. fma-udef99.4%

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

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

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

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

    \[\leadsto \frac{1 - \color{blue}{\left(\left(1 + {\tan x}^{2}\right) + -1\right)}}{1 + \tan x \cdot \tan x} \]
  8. Step-by-step derivation
    1. div-sub99.2%

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

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

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

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

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

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

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

    \[\leadsto \color{blue}{\frac{1}{{\tan x}^{2} + 1} - \frac{-1 + \left({\tan x}^{2} + 1\right)}{{\tan x}^{2} + 1}} \]
  10. Step-by-step derivation
    1. div-sub99.4%

      \[\leadsto \color{blue}{\frac{1 - \left(-1 + \left({\tan x}^{2} + 1\right)\right)}{{\tan x}^{2} + 1}} \]
    2. associate--r+99.4%

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

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

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

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

      \[\leadsto \frac{\color{blue}{1} - {\tan x}^{2}}{{\tan x}^{2} + 1} \]
    7. +-commutative99.5%

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

    \[\leadsto \color{blue}{\frac{1 - {\tan x}^{2}}{1 + {\tan x}^{2}}} \]
  12. Final simplification99.5%

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

Alternative 4: 99.3% accurate, 2.0× speedup?

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

\\
-1 + \frac{2}{1 + {\tan x}^{2}}
\end{array}
Derivation
  1. Initial program 99.5%

    \[\frac{1 - \tan x \cdot \tan x}{1 + \tan x \cdot \tan x} \]
  2. Step-by-step derivation
    1. pow299.5%

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

      \[\leadsto \frac{1 - {\tan x}^{\color{blue}{\left(6 \cdot 0.3333333333333333\right)}}}{1 + \tan x \cdot \tan x} \]
    3. metadata-eval99.5%

      \[\leadsto \frac{1 - {\tan x}^{\left(\color{blue}{\left(2 \cdot 3\right)} \cdot 0.3333333333333333\right)}}{1 + \tan x \cdot \tan x} \]
    4. pow-pow99.2%

      \[\leadsto \frac{1 - \color{blue}{{\left({\tan x}^{\left(2 \cdot 3\right)}\right)}^{0.3333333333333333}}}{1 + \tan x \cdot \tan x} \]
    5. metadata-eval99.2%

      \[\leadsto \frac{1 - {\left({\tan x}^{\color{blue}{6}}\right)}^{0.3333333333333333}}{1 + \tan x \cdot \tan x} \]
  3. Applied egg-rr99.2%

    \[\leadsto \frac{1 - \color{blue}{{\left({\tan x}^{6}\right)}^{0.3333333333333333}}}{1 + \tan x \cdot \tan x} \]
  4. Step-by-step derivation
    1. pow-pow99.5%

      \[\leadsto \frac{1 - \color{blue}{{\tan x}^{\left(6 \cdot 0.3333333333333333\right)}}}{1 + \tan x \cdot \tan x} \]
    2. metadata-eval99.5%

      \[\leadsto \frac{1 - {\tan x}^{\color{blue}{2}}}{1 + \tan x \cdot \tan x} \]
    3. pow299.5%

      \[\leadsto \frac{1 - \color{blue}{\tan x \cdot \tan x}}{1 + \tan x \cdot \tan x} \]
    4. tan-quot99.4%

      \[\leadsto \frac{1 - \tan x \cdot \color{blue}{\frac{\sin x}{\cos x}}}{1 + \tan x \cdot \tan x} \]
    5. associate-*r/99.4%

      \[\leadsto \frac{1 - \color{blue}{\frac{\tan x \cdot \sin x}{\cos x}}}{1 + \tan x \cdot \tan x} \]
    6. expm1-log1p-u99.2%

      \[\leadsto \frac{1 - \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{\tan x \cdot \sin x}{\cos x}\right)\right)}}{1 + \tan x \cdot \tan x} \]
    7. expm1-udef99.0%

      \[\leadsto \frac{1 - \color{blue}{\left(e^{\mathsf{log1p}\left(\frac{\tan x \cdot \sin x}{\cos x}\right)} - 1\right)}}{1 + \tan x \cdot \tan x} \]
    8. log1p-udef99.1%

      \[\leadsto \frac{1 - \left(e^{\color{blue}{\log \left(1 + \frac{\tan x \cdot \sin x}{\cos x}\right)}} - 1\right)}{1 + \tan x \cdot \tan x} \]
    9. add-exp-log99.3%

      \[\leadsto \frac{1 - \left(\color{blue}{\left(1 + \frac{\tan x \cdot \sin x}{\cos x}\right)} - 1\right)}{1 + \tan x \cdot \tan x} \]
    10. associate-*r/99.3%

      \[\leadsto \frac{1 - \left(\left(1 + \color{blue}{\tan x \cdot \frac{\sin x}{\cos x}}\right) - 1\right)}{1 + \tan x \cdot \tan x} \]
    11. tan-quot99.4%

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

      \[\leadsto \frac{1 - \left(\color{blue}{\left(\tan x \cdot \tan x + 1\right)} - 1\right)}{1 + \tan x \cdot \tan x} \]
    13. fma-udef99.4%

      \[\leadsto \frac{1 - \left(\color{blue}{\mathsf{fma}\left(\tan x, \tan x, 1\right)} - 1\right)}{1 + \tan x \cdot \tan x} \]
  5. Applied egg-rr99.4%

    \[\leadsto \frac{1 - \color{blue}{\left(\mathsf{fma}\left(\tan x, \tan x, 1\right) - 1\right)}}{1 + \tan x \cdot \tan x} \]
  6. Step-by-step derivation
    1. sub-neg99.4%

      \[\leadsto \frac{1 - \color{blue}{\left(\mathsf{fma}\left(\tan x, \tan x, 1\right) + \left(-1\right)\right)}}{1 + \tan x \cdot \tan x} \]
    2. fma-udef99.4%

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

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

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

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

    \[\leadsto \frac{1 - \color{blue}{\left(\left(1 + {\tan x}^{2}\right) + -1\right)}}{1 + \tan x \cdot \tan x} \]
  8. Step-by-step derivation
    1. div-sub99.2%

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

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

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

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

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

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

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

    \[\leadsto \color{blue}{\frac{1}{{\tan x}^{2} + 1} - \frac{-1 + \left({\tan x}^{2} + 1\right)}{{\tan x}^{2} + 1}} \]
  10. Step-by-step derivation
    1. div-sub99.4%

      \[\leadsto \color{blue}{\frac{1 - \left(-1 + \left({\tan x}^{2} + 1\right)\right)}{{\tan x}^{2} + 1}} \]
    2. associate--r+99.4%

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

      \[\leadsto \frac{\color{blue}{2} - \left({\tan x}^{2} + 1\right)}{{\tan x}^{2} + 1} \]
    4. div-sub99.3%

      \[\leadsto \color{blue}{\frac{2}{{\tan x}^{2} + 1} - \frac{{\tan x}^{2} + 1}{{\tan x}^{2} + 1}} \]
    5. sub-neg99.3%

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

      \[\leadsto \frac{2}{\color{blue}{1 + {\tan x}^{2}}} + \left(-\frac{{\tan x}^{2} + 1}{{\tan x}^{2} + 1}\right) \]
    7. *-inverses99.3%

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

      \[\leadsto \frac{2}{1 + {\tan x}^{2}} + \color{blue}{-1} \]
  11. Simplified99.3%

    \[\leadsto \color{blue}{\frac{2}{1 + {\tan x}^{2}} + -1} \]
  12. Final simplification99.3%

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

Alternative 5: 55.3% accurate, 2.0× speedup?

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

\\
\frac{-1}{-1 - {\tan x}^{2}}
\end{array}
Derivation
  1. Initial program 99.5%

    \[\frac{1 - \tan x \cdot \tan x}{1 + \tan x \cdot \tan x} \]
  2. Step-by-step derivation
    1. frac-2neg99.5%

      \[\leadsto \color{blue}{\frac{-\left(1 - \tan x \cdot \tan x\right)}{-\left(1 + \tan x \cdot \tan x\right)}} \]
    2. div-inv99.4%

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

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

      \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{-\color{blue}{\left(\tan x \cdot \tan x + 1\right)}} \]
    5. distribute-neg-in99.4%

      \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{\color{blue}{\left(-\tan x \cdot \tan x\right) + \left(-1\right)}} \]
    6. neg-mul-199.4%

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

      \[\leadsto \left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{-1 \cdot \left(\tan x \cdot \tan x\right) + \color{blue}{-1}} \]
    8. fma-def99.4%

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

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

    \[\leadsto \color{blue}{\left(-\left(1 - {\tan x}^{2}\right)\right) \cdot \frac{1}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)}} \]
  4. Step-by-step derivation
    1. associate-*r/99.5%

      \[\leadsto \color{blue}{\frac{\left(-\left(1 - {\tan x}^{2}\right)\right) \cdot 1}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)}} \]
    2. *-rgt-identity99.5%

      \[\leadsto \frac{\color{blue}{-\left(1 - {\tan x}^{2}\right)}}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
    3. neg-sub099.5%

      \[\leadsto \frac{\color{blue}{0 - \left(1 - {\tan x}^{2}\right)}}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
    4. associate--r-99.5%

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

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

      \[\leadsto \frac{\color{blue}{{\tan x}^{2} + -1}}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
    7. unpow299.5%

      \[\leadsto \frac{\color{blue}{\tan x \cdot \tan x} + -1}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
    8. fma-udef99.5%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\tan x, \tan x, -1\right)}}{\mathsf{fma}\left(-1, {\tan x}^{2}, -1\right)} \]
    9. fma-udef99.5%

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

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

      \[\leadsto \frac{\mathsf{fma}\left(\tan x, \tan x, -1\right)}{\color{blue}{-1 + \left(-{\tan x}^{2}\right)}} \]
    12. unsub-neg99.5%

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

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\tan x, \tan x, -1\right)}{-1 - {\tan x}^{2}}} \]
  6. Taylor expanded in x around 0 54.6%

    \[\leadsto \frac{\color{blue}{-1}}{-1 - {\tan x}^{2}} \]
  7. Final simplification54.6%

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

Alternative 6: 54.9% 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 99.5%

    \[\frac{1 - \tan x \cdot \tan x}{1 + \tan x \cdot \tan x} \]
  2. Taylor expanded in x around 0 54.2%

    \[\leadsto \color{blue}{1} \]
  3. Final simplification54.2%

    \[\leadsto 1 \]

Reproduce

?
herbie shell --seed 2023181 
(FPCore (x)
  :name "Trigonometry B"
  :precision binary64
  (/ (- 1.0 (* (tan x) (tan x))) (+ 1.0 (* (tan x) (tan x)))))