Kahan p13 Example 2

Percentage Accurate: 99.9% → 100.0%
Time: 26.7s
Alternatives: 8
Speedup: 1.9×

Specification

?
\[\begin{array}{l} \\ \begin{array}{l} t_1 := 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\\ t_2 := t_1 \cdot t_1\\ \frac{1 + t_2}{2 + t_2} \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (- 2.0 (/ (/ 2.0 t) (+ 1.0 (/ 1.0 t))))) (t_2 (* t_1 t_1)))
   (/ (+ 1.0 t_2) (+ 2.0 t_2))))
double code(double t) {
	double t_1 = 2.0 - ((2.0 / t) / (1.0 + (1.0 / t)));
	double t_2 = t_1 * t_1;
	return (1.0 + t_2) / (2.0 + t_2);
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: t_2
    t_1 = 2.0d0 - ((2.0d0 / t) / (1.0d0 + (1.0d0 / t)))
    t_2 = t_1 * t_1
    code = (1.0d0 + t_2) / (2.0d0 + t_2)
end function
public static double code(double t) {
	double t_1 = 2.0 - ((2.0 / t) / (1.0 + (1.0 / t)));
	double t_2 = t_1 * t_1;
	return (1.0 + t_2) / (2.0 + t_2);
}
def code(t):
	t_1 = 2.0 - ((2.0 / t) / (1.0 + (1.0 / t)))
	t_2 = t_1 * t_1
	return (1.0 + t_2) / (2.0 + t_2)
function code(t)
	t_1 = Float64(2.0 - Float64(Float64(2.0 / t) / Float64(1.0 + Float64(1.0 / t))))
	t_2 = Float64(t_1 * t_1)
	return Float64(Float64(1.0 + t_2) / Float64(2.0 + t_2))
end
function tmp = code(t)
	t_1 = 2.0 - ((2.0 / t) / (1.0 + (1.0 / t)));
	t_2 = t_1 * t_1;
	tmp = (1.0 + t_2) / (2.0 + t_2);
end
code[t_] := Block[{t$95$1 = N[(2.0 - N[(N[(2.0 / t), $MachinePrecision] / N[(1.0 + N[(1.0 / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(t$95$1 * t$95$1), $MachinePrecision]}, N[(N[(1.0 + t$95$2), $MachinePrecision] / N[(2.0 + t$95$2), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\\
t_2 := t_1 \cdot t_1\\
\frac{1 + t_2}{2 + t_2}
\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 8 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: 99.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\\ t_2 := t_1 \cdot t_1\\ \frac{1 + t_2}{2 + t_2} \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (- 2.0 (/ (/ 2.0 t) (+ 1.0 (/ 1.0 t))))) (t_2 (* t_1 t_1)))
   (/ (+ 1.0 t_2) (+ 2.0 t_2))))
double code(double t) {
	double t_1 = 2.0 - ((2.0 / t) / (1.0 + (1.0 / t)));
	double t_2 = t_1 * t_1;
	return (1.0 + t_2) / (2.0 + t_2);
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: t_2
    t_1 = 2.0d0 - ((2.0d0 / t) / (1.0d0 + (1.0d0 / t)))
    t_2 = t_1 * t_1
    code = (1.0d0 + t_2) / (2.0d0 + t_2)
end function
public static double code(double t) {
	double t_1 = 2.0 - ((2.0 / t) / (1.0 + (1.0 / t)));
	double t_2 = t_1 * t_1;
	return (1.0 + t_2) / (2.0 + t_2);
}
def code(t):
	t_1 = 2.0 - ((2.0 / t) / (1.0 + (1.0 / t)))
	t_2 = t_1 * t_1
	return (1.0 + t_2) / (2.0 + t_2)
function code(t)
	t_1 = Float64(2.0 - Float64(Float64(2.0 / t) / Float64(1.0 + Float64(1.0 / t))))
	t_2 = Float64(t_1 * t_1)
	return Float64(Float64(1.0 + t_2) / Float64(2.0 + t_2))
end
function tmp = code(t)
	t_1 = 2.0 - ((2.0 / t) / (1.0 + (1.0 / t)));
	t_2 = t_1 * t_1;
	tmp = (1.0 + t_2) / (2.0 + t_2);
end
code[t_] := Block[{t$95$1 = N[(2.0 - N[(N[(2.0 / t), $MachinePrecision] / N[(1.0 + N[(1.0 / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(t$95$1 * t$95$1), $MachinePrecision]}, N[(N[(1.0 + t$95$2), $MachinePrecision] / N[(2.0 + t$95$2), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := 2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\\
t_2 := t_1 \cdot t_1\\
\frac{1 + t_2}{2 + t_2}
\end{array}
\end{array}

Alternative 1: 100.0% accurate, 1.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{-2}{1 + t}\\ t_2 := t_1 \cdot \left(t_1 - -4\right)\\ \frac{5 + t_2}{t_2 + 6} \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (/ -2.0 (+ 1.0 t))) (t_2 (* t_1 (- t_1 -4.0))))
   (/ (+ 5.0 t_2) (+ t_2 6.0))))
double code(double t) {
	double t_1 = -2.0 / (1.0 + t);
	double t_2 = t_1 * (t_1 - -4.0);
	return (5.0 + t_2) / (t_2 + 6.0);
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: t_2
    t_1 = (-2.0d0) / (1.0d0 + t)
    t_2 = t_1 * (t_1 - (-4.0d0))
    code = (5.0d0 + t_2) / (t_2 + 6.0d0)
end function
public static double code(double t) {
	double t_1 = -2.0 / (1.0 + t);
	double t_2 = t_1 * (t_1 - -4.0);
	return (5.0 + t_2) / (t_2 + 6.0);
}
def code(t):
	t_1 = -2.0 / (1.0 + t)
	t_2 = t_1 * (t_1 - -4.0)
	return (5.0 + t_2) / (t_2 + 6.0)
function code(t)
	t_1 = Float64(-2.0 / Float64(1.0 + t))
	t_2 = Float64(t_1 * Float64(t_1 - -4.0))
	return Float64(Float64(5.0 + t_2) / Float64(t_2 + 6.0))
end
function tmp = code(t)
	t_1 = -2.0 / (1.0 + t);
	t_2 = t_1 * (t_1 - -4.0);
	tmp = (5.0 + t_2) / (t_2 + 6.0);
end
code[t_] := Block[{t$95$1 = N[(-2.0 / N[(1.0 + t), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(t$95$1 * N[(t$95$1 - -4.0), $MachinePrecision]), $MachinePrecision]}, N[(N[(5.0 + t$95$2), $MachinePrecision] / N[(t$95$2 + 6.0), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{-2}{1 + t}\\
t_2 := t_1 \cdot \left(t_1 - -4\right)\\
\frac{5 + t_2}{t_2 + 6}
\end{array}
\end{array}
Derivation
  1. Initial program 99.6%

    \[\frac{1 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
  2. Simplified100.0%

    \[\leadsto \color{blue}{\frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}} \]
  3. Add Preprocessing
  4. Final simplification100.0%

    \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right) + 6} \]
  5. Add Preprocessing

Alternative 2: 100.0% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{-2}{1 + t}\\ \frac{5 + t_1 \cdot \left(t_1 - -4\right)}{6 + \frac{\frac{4}{1 + t} + -8}{1 + t}} \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (/ -2.0 (+ 1.0 t))))
   (/
    (+ 5.0 (* t_1 (- t_1 -4.0)))
    (+ 6.0 (/ (+ (/ 4.0 (+ 1.0 t)) -8.0) (+ 1.0 t))))))
double code(double t) {
	double t_1 = -2.0 / (1.0 + t);
	return (5.0 + (t_1 * (t_1 - -4.0))) / (6.0 + (((4.0 / (1.0 + t)) + -8.0) / (1.0 + t)));
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    t_1 = (-2.0d0) / (1.0d0 + t)
    code = (5.0d0 + (t_1 * (t_1 - (-4.0d0)))) / (6.0d0 + (((4.0d0 / (1.0d0 + t)) + (-8.0d0)) / (1.0d0 + t)))
end function
public static double code(double t) {
	double t_1 = -2.0 / (1.0 + t);
	return (5.0 + (t_1 * (t_1 - -4.0))) / (6.0 + (((4.0 / (1.0 + t)) + -8.0) / (1.0 + t)));
}
def code(t):
	t_1 = -2.0 / (1.0 + t)
	return (5.0 + (t_1 * (t_1 - -4.0))) / (6.0 + (((4.0 / (1.0 + t)) + -8.0) / (1.0 + t)))
function code(t)
	t_1 = Float64(-2.0 / Float64(1.0 + t))
	return Float64(Float64(5.0 + Float64(t_1 * Float64(t_1 - -4.0))) / Float64(6.0 + Float64(Float64(Float64(4.0 / Float64(1.0 + t)) + -8.0) / Float64(1.0 + t))))
end
function tmp = code(t)
	t_1 = -2.0 / (1.0 + t);
	tmp = (5.0 + (t_1 * (t_1 - -4.0))) / (6.0 + (((4.0 / (1.0 + t)) + -8.0) / (1.0 + t)));
end
code[t_] := Block[{t$95$1 = N[(-2.0 / N[(1.0 + t), $MachinePrecision]), $MachinePrecision]}, N[(N[(5.0 + N[(t$95$1 * N[(t$95$1 - -4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(6.0 + N[(N[(N[(4.0 / N[(1.0 + t), $MachinePrecision]), $MachinePrecision] + -8.0), $MachinePrecision] / N[(1.0 + t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{-2}{1 + t}\\
\frac{5 + t_1 \cdot \left(t_1 - -4\right)}{6 + \frac{\frac{4}{1 + t} + -8}{1 + t}}
\end{array}
\end{array}
Derivation
  1. Initial program 99.6%

    \[\frac{1 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
  2. Simplified100.0%

    \[\leadsto \color{blue}{\frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}} \]
  3. Add Preprocessing
  4. Step-by-step derivation
    1. add-log-exp100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\log \left(e^{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}\right)}} \]
    2. *-un-lft-identity100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \log \color{blue}{\left(1 \cdot e^{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}\right)}} \]
    3. log-prod100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\left(\log 1 + \log \left(e^{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}\right)\right)}} \]
    4. metadata-eval100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(\color{blue}{0} + \log \left(e^{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}\right)\right)} \]
    5. associate-*l/100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \log \left(e^{\color{blue}{\frac{-2 \cdot \left(\frac{-2}{1 + t} - -4\right)}{1 + t}}}\right)\right)} \]
    6. add-log-exp100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \color{blue}{\frac{-2 \cdot \left(\frac{-2}{1 + t} - -4\right)}{1 + t}}\right)} \]
    7. sub-neg100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{-2 \cdot \color{blue}{\left(\frac{-2}{1 + t} + \left(--4\right)\right)}}{1 + t}\right)} \]
    8. distribute-lft-in100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{\color{blue}{-2 \cdot \frac{-2}{1 + t} + -2 \cdot \left(--4\right)}}{1 + t}\right)} \]
    9. metadata-eval100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{-2 \cdot \frac{-2}{1 + t} + -2 \cdot \color{blue}{4}}{1 + t}\right)} \]
    10. metadata-eval100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{-2 \cdot \frac{-2}{1 + t} + \color{blue}{-8}}{1 + t}\right)} \]
    11. metadata-eval100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{-2 \cdot \frac{-2}{1 + t} + \color{blue}{{-2}^{3}}}{1 + t}\right)} \]
    12. fma-def100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{\color{blue}{\mathsf{fma}\left(-2, \frac{-2}{1 + t}, {-2}^{3}\right)}}{1 + t}\right)} \]
    13. metadata-eval100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{\mathsf{fma}\left(-2, \frac{-2}{1 + t}, \color{blue}{-8}\right)}{1 + t}\right)} \]
  5. Applied egg-rr100.0%

    \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\left(0 + \frac{\mathsf{fma}\left(-2, \frac{-2}{1 + t}, -8\right)}{1 + t}\right)}} \]
  6. Step-by-step derivation
    1. +-lft-identity100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\frac{\mathsf{fma}\left(-2, \frac{-2}{1 + t}, -8\right)}{1 + t}}} \]
    2. fma-udef100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\color{blue}{-2 \cdot \frac{-2}{1 + t} + -8}}{1 + t}} \]
    3. associate-*r/100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\color{blue}{\frac{-2 \cdot -2}{1 + t}} + -8}{1 + t}} \]
    4. metadata-eval100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\frac{\color{blue}{4}}{1 + t} + -8}{1 + t}} \]
    5. +-commutative100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\frac{4}{\color{blue}{t + 1}} + -8}{1 + t}} \]
    6. +-commutative100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\frac{4}{t + 1} + -8}{\color{blue}{t + 1}}} \]
  7. Simplified100.0%

    \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\frac{\frac{4}{t + 1} + -8}{t + 1}}} \]
  8. Final simplification100.0%

    \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\frac{4}{1 + t} + -8}{1 + t}} \]
  9. Add Preprocessing

Alternative 3: 99.0% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{-8 + \frac{4}{t}}{1 + t}\\ \mathbf{if}\;t \leq -0.42:\\ \;\;\;\;\frac{5 + t_1}{6 + t_1}\\ \mathbf{elif}\;t \leq 2:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{5 - \frac{8}{t}}{6 + \frac{-8}{t}}\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (/ (+ -8.0 (/ 4.0 t)) (+ 1.0 t))))
   (if (<= t -0.42)
     (/ (+ 5.0 t_1) (+ 6.0 t_1))
     (if (<= t 2.0) 0.5 (/ (- 5.0 (/ 8.0 t)) (+ 6.0 (/ -8.0 t)))))))
double code(double t) {
	double t_1 = (-8.0 + (4.0 / t)) / (1.0 + t);
	double tmp;
	if (t <= -0.42) {
		tmp = (5.0 + t_1) / (6.0 + t_1);
	} else if (t <= 2.0) {
		tmp = 0.5;
	} else {
		tmp = (5.0 - (8.0 / t)) / (6.0 + (-8.0 / t));
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: tmp
    t_1 = ((-8.0d0) + (4.0d0 / t)) / (1.0d0 + t)
    if (t <= (-0.42d0)) then
        tmp = (5.0d0 + t_1) / (6.0d0 + t_1)
    else if (t <= 2.0d0) then
        tmp = 0.5d0
    else
        tmp = (5.0d0 - (8.0d0 / t)) / (6.0d0 + ((-8.0d0) / t))
    end if
    code = tmp
end function
public static double code(double t) {
	double t_1 = (-8.0 + (4.0 / t)) / (1.0 + t);
	double tmp;
	if (t <= -0.42) {
		tmp = (5.0 + t_1) / (6.0 + t_1);
	} else if (t <= 2.0) {
		tmp = 0.5;
	} else {
		tmp = (5.0 - (8.0 / t)) / (6.0 + (-8.0 / t));
	}
	return tmp;
}
def code(t):
	t_1 = (-8.0 + (4.0 / t)) / (1.0 + t)
	tmp = 0
	if t <= -0.42:
		tmp = (5.0 + t_1) / (6.0 + t_1)
	elif t <= 2.0:
		tmp = 0.5
	else:
		tmp = (5.0 - (8.0 / t)) / (6.0 + (-8.0 / t))
	return tmp
function code(t)
	t_1 = Float64(Float64(-8.0 + Float64(4.0 / t)) / Float64(1.0 + t))
	tmp = 0.0
	if (t <= -0.42)
		tmp = Float64(Float64(5.0 + t_1) / Float64(6.0 + t_1));
	elseif (t <= 2.0)
		tmp = 0.5;
	else
		tmp = Float64(Float64(5.0 - Float64(8.0 / t)) / Float64(6.0 + Float64(-8.0 / t)));
	end
	return tmp
end
function tmp_2 = code(t)
	t_1 = (-8.0 + (4.0 / t)) / (1.0 + t);
	tmp = 0.0;
	if (t <= -0.42)
		tmp = (5.0 + t_1) / (6.0 + t_1);
	elseif (t <= 2.0)
		tmp = 0.5;
	else
		tmp = (5.0 - (8.0 / t)) / (6.0 + (-8.0 / t));
	end
	tmp_2 = tmp;
end
code[t_] := Block[{t$95$1 = N[(N[(-8.0 + N[(4.0 / t), $MachinePrecision]), $MachinePrecision] / N[(1.0 + t), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t, -0.42], N[(N[(5.0 + t$95$1), $MachinePrecision] / N[(6.0 + t$95$1), $MachinePrecision]), $MachinePrecision], If[LessEqual[t, 2.0], 0.5, N[(N[(5.0 - N[(8.0 / t), $MachinePrecision]), $MachinePrecision] / N[(6.0 + N[(-8.0 / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{-8 + \frac{4}{t}}{1 + t}\\
\mathbf{if}\;t \leq -0.42:\\
\;\;\;\;\frac{5 + t_1}{6 + t_1}\\

\mathbf{elif}\;t \leq 2:\\
\;\;\;\;0.5\\

\mathbf{else}:\\
\;\;\;\;\frac{5 - \frac{8}{t}}{6 + \frac{-8}{t}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if t < -0.419999999999999984

    1. Initial program 100.0%

      \[\frac{1 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{\frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}} \]
    3. Add Preprocessing
    4. Step-by-step derivation
      1. add-log-exp100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\log \left(e^{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}\right)}} \]
      2. *-un-lft-identity100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \log \color{blue}{\left(1 \cdot e^{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}\right)}} \]
      3. log-prod100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\left(\log 1 + \log \left(e^{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}\right)\right)}} \]
      4. metadata-eval100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(\color{blue}{0} + \log \left(e^{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}\right)\right)} \]
      5. associate-*l/100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \log \left(e^{\color{blue}{\frac{-2 \cdot \left(\frac{-2}{1 + t} - -4\right)}{1 + t}}}\right)\right)} \]
      6. add-log-exp100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \color{blue}{\frac{-2 \cdot \left(\frac{-2}{1 + t} - -4\right)}{1 + t}}\right)} \]
      7. sub-neg100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{-2 \cdot \color{blue}{\left(\frac{-2}{1 + t} + \left(--4\right)\right)}}{1 + t}\right)} \]
      8. distribute-lft-in100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{\color{blue}{-2 \cdot \frac{-2}{1 + t} + -2 \cdot \left(--4\right)}}{1 + t}\right)} \]
      9. metadata-eval100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{-2 \cdot \frac{-2}{1 + t} + -2 \cdot \color{blue}{4}}{1 + t}\right)} \]
      10. metadata-eval100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{-2 \cdot \frac{-2}{1 + t} + \color{blue}{-8}}{1 + t}\right)} \]
      11. metadata-eval100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{-2 \cdot \frac{-2}{1 + t} + \color{blue}{{-2}^{3}}}{1 + t}\right)} \]
      12. fma-def100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{\color{blue}{\mathsf{fma}\left(-2, \frac{-2}{1 + t}, {-2}^{3}\right)}}{1 + t}\right)} \]
      13. metadata-eval100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{\mathsf{fma}\left(-2, \frac{-2}{1 + t}, \color{blue}{-8}\right)}{1 + t}\right)} \]
    5. Applied egg-rr100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\left(0 + \frac{\mathsf{fma}\left(-2, \frac{-2}{1 + t}, -8\right)}{1 + t}\right)}} \]
    6. Step-by-step derivation
      1. +-lft-identity100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\frac{\mathsf{fma}\left(-2, \frac{-2}{1 + t}, -8\right)}{1 + t}}} \]
      2. fma-udef100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\color{blue}{-2 \cdot \frac{-2}{1 + t} + -8}}{1 + t}} \]
      3. associate-*r/100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\color{blue}{\frac{-2 \cdot -2}{1 + t}} + -8}{1 + t}} \]
      4. metadata-eval100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\frac{\color{blue}{4}}{1 + t} + -8}{1 + t}} \]
      5. +-commutative100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\frac{4}{\color{blue}{t + 1}} + -8}{1 + t}} \]
      6. +-commutative100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\frac{4}{t + 1} + -8}{\color{blue}{t + 1}}} \]
    7. Simplified100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\frac{\frac{4}{t + 1} + -8}{t + 1}}} \]
    8. Step-by-step derivation
      1. add-log-exp100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\log \left(e^{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}\right)}} \]
      2. *-un-lft-identity100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \log \color{blue}{\left(1 \cdot e^{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}\right)}} \]
      3. log-prod100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\left(\log 1 + \log \left(e^{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}\right)\right)}} \]
      4. metadata-eval100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(\color{blue}{0} + \log \left(e^{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}\right)\right)} \]
      5. associate-*l/100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \log \left(e^{\color{blue}{\frac{-2 \cdot \left(\frac{-2}{1 + t} - -4\right)}{1 + t}}}\right)\right)} \]
      6. add-log-exp100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \color{blue}{\frac{-2 \cdot \left(\frac{-2}{1 + t} - -4\right)}{1 + t}}\right)} \]
      7. sub-neg100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{-2 \cdot \color{blue}{\left(\frac{-2}{1 + t} + \left(--4\right)\right)}}{1 + t}\right)} \]
      8. distribute-lft-in100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{\color{blue}{-2 \cdot \frac{-2}{1 + t} + -2 \cdot \left(--4\right)}}{1 + t}\right)} \]
      9. metadata-eval100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{-2 \cdot \frac{-2}{1 + t} + -2 \cdot \color{blue}{4}}{1 + t}\right)} \]
      10. metadata-eval100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{-2 \cdot \frac{-2}{1 + t} + \color{blue}{-8}}{1 + t}\right)} \]
      11. metadata-eval100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{-2 \cdot \frac{-2}{1 + t} + \color{blue}{{-2}^{3}}}{1 + t}\right)} \]
      12. fma-def100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{\color{blue}{\mathsf{fma}\left(-2, \frac{-2}{1 + t}, {-2}^{3}\right)}}{1 + t}\right)} \]
      13. metadata-eval100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{\mathsf{fma}\left(-2, \frac{-2}{1 + t}, \color{blue}{-8}\right)}{1 + t}\right)} \]
    9. Applied egg-rr100.0%

      \[\leadsto \frac{5 + \color{blue}{\left(0 + \frac{\mathsf{fma}\left(-2, \frac{-2}{1 + t}, -8\right)}{1 + t}\right)}}{6 + \frac{\frac{4}{t + 1} + -8}{t + 1}} \]
    10. Step-by-step derivation
      1. +-lft-identity100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\frac{\mathsf{fma}\left(-2, \frac{-2}{1 + t}, -8\right)}{1 + t}}} \]
      2. fma-udef100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\color{blue}{-2 \cdot \frac{-2}{1 + t} + -8}}{1 + t}} \]
      3. associate-*r/100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\color{blue}{\frac{-2 \cdot -2}{1 + t}} + -8}{1 + t}} \]
      4. metadata-eval100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\frac{\color{blue}{4}}{1 + t} + -8}{1 + t}} \]
      5. +-commutative100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\frac{4}{\color{blue}{t + 1}} + -8}{1 + t}} \]
      6. +-commutative100.0%

        \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\frac{4}{t + 1} + -8}{\color{blue}{t + 1}}} \]
    11. Simplified100.0%

      \[\leadsto \frac{5 + \color{blue}{\frac{\frac{4}{t + 1} + -8}{t + 1}}}{6 + \frac{\frac{4}{t + 1} + -8}{t + 1}} \]
    12. Taylor expanded in t around inf 97.0%

      \[\leadsto \frac{5 + \frac{\frac{4}{t + 1} + -8}{t + 1}}{6 + \frac{\color{blue}{\frac{4}{t}} + -8}{t + 1}} \]
    13. Taylor expanded in t around inf 97.5%

      \[\leadsto \frac{5 + \frac{\color{blue}{4 \cdot \frac{1}{t} - 8}}{t + 1}}{6 + \frac{\frac{4}{t} + -8}{t + 1}} \]
    14. Step-by-step derivation
      1. sub-neg97.5%

        \[\leadsto \frac{5 + \frac{\color{blue}{4 \cdot \frac{1}{t} + \left(-8\right)}}{t + 1}}{6 + \frac{\frac{4}{t} + -8}{t + 1}} \]
      2. associate-*r/97.5%

        \[\leadsto \frac{5 + \frac{\color{blue}{\frac{4 \cdot 1}{t}} + \left(-8\right)}{t + 1}}{6 + \frac{\frac{4}{t} + -8}{t + 1}} \]
      3. metadata-eval97.5%

        \[\leadsto \frac{5 + \frac{\frac{\color{blue}{4}}{t} + \left(-8\right)}{t + 1}}{6 + \frac{\frac{4}{t} + -8}{t + 1}} \]
      4. metadata-eval97.5%

        \[\leadsto \frac{5 + \frac{\frac{4}{t} + \color{blue}{-8}}{t + 1}}{6 + \frac{\frac{4}{t} + -8}{t + 1}} \]
    15. Simplified97.5%

      \[\leadsto \frac{5 + \frac{\color{blue}{\frac{4}{t} + -8}}{t + 1}}{6 + \frac{\frac{4}{t} + -8}{t + 1}} \]

    if -0.419999999999999984 < t < 2

    1. Initial program 99.2%

      \[\frac{1 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{\frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around 0 98.8%

      \[\leadsto \frac{\color{blue}{1}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
    5. Taylor expanded in t around 0 98.9%

      \[\leadsto \color{blue}{0.5} \]

    if 2 < t

    1. Initial program 100.0%

      \[\frac{1 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{\frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around inf 100.0%

      \[\leadsto \frac{\color{blue}{5 - 8 \cdot \frac{1}{t}}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
    5. Step-by-step derivation
      1. associate-*r/100.0%

        \[\leadsto \frac{5 - \color{blue}{\frac{8 \cdot 1}{t}}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
      2. metadata-eval100.0%

        \[\leadsto \frac{5 - \frac{\color{blue}{8}}{t}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
    6. Simplified100.0%

      \[\leadsto \frac{\color{blue}{5 - \frac{8}{t}}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
    7. Taylor expanded in t around inf 100.0%

      \[\leadsto \frac{5 - \frac{8}{t}}{6 + \color{blue}{\frac{-8}{t}}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification98.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -0.42:\\ \;\;\;\;\frac{5 + \frac{-8 + \frac{4}{t}}{1 + t}}{6 + \frac{-8 + \frac{4}{t}}{1 + t}}\\ \mathbf{elif}\;t \leq 2:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{5 - \frac{8}{t}}{6 + \frac{-8}{t}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 100.0% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{\frac{4}{1 + t} + -8}{1 + t}\\ \frac{5 + t_1}{6 + t_1} \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (/ (+ (/ 4.0 (+ 1.0 t)) -8.0) (+ 1.0 t))))
   (/ (+ 5.0 t_1) (+ 6.0 t_1))))
double code(double t) {
	double t_1 = ((4.0 / (1.0 + t)) + -8.0) / (1.0 + t);
	return (5.0 + t_1) / (6.0 + t_1);
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    t_1 = ((4.0d0 / (1.0d0 + t)) + (-8.0d0)) / (1.0d0 + t)
    code = (5.0d0 + t_1) / (6.0d0 + t_1)
end function
public static double code(double t) {
	double t_1 = ((4.0 / (1.0 + t)) + -8.0) / (1.0 + t);
	return (5.0 + t_1) / (6.0 + t_1);
}
def code(t):
	t_1 = ((4.0 / (1.0 + t)) + -8.0) / (1.0 + t)
	return (5.0 + t_1) / (6.0 + t_1)
function code(t)
	t_1 = Float64(Float64(Float64(4.0 / Float64(1.0 + t)) + -8.0) / Float64(1.0 + t))
	return Float64(Float64(5.0 + t_1) / Float64(6.0 + t_1))
end
function tmp = code(t)
	t_1 = ((4.0 / (1.0 + t)) + -8.0) / (1.0 + t);
	tmp = (5.0 + t_1) / (6.0 + t_1);
end
code[t_] := Block[{t$95$1 = N[(N[(N[(4.0 / N[(1.0 + t), $MachinePrecision]), $MachinePrecision] + -8.0), $MachinePrecision] / N[(1.0 + t), $MachinePrecision]), $MachinePrecision]}, N[(N[(5.0 + t$95$1), $MachinePrecision] / N[(6.0 + t$95$1), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{\frac{4}{1 + t} + -8}{1 + t}\\
\frac{5 + t_1}{6 + t_1}
\end{array}
\end{array}
Derivation
  1. Initial program 99.6%

    \[\frac{1 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
  2. Simplified100.0%

    \[\leadsto \color{blue}{\frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}} \]
  3. Add Preprocessing
  4. Step-by-step derivation
    1. add-log-exp100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\log \left(e^{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}\right)}} \]
    2. *-un-lft-identity100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \log \color{blue}{\left(1 \cdot e^{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}\right)}} \]
    3. log-prod100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\left(\log 1 + \log \left(e^{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}\right)\right)}} \]
    4. metadata-eval100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(\color{blue}{0} + \log \left(e^{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}\right)\right)} \]
    5. associate-*l/100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \log \left(e^{\color{blue}{\frac{-2 \cdot \left(\frac{-2}{1 + t} - -4\right)}{1 + t}}}\right)\right)} \]
    6. add-log-exp100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \color{blue}{\frac{-2 \cdot \left(\frac{-2}{1 + t} - -4\right)}{1 + t}}\right)} \]
    7. sub-neg100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{-2 \cdot \color{blue}{\left(\frac{-2}{1 + t} + \left(--4\right)\right)}}{1 + t}\right)} \]
    8. distribute-lft-in100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{\color{blue}{-2 \cdot \frac{-2}{1 + t} + -2 \cdot \left(--4\right)}}{1 + t}\right)} \]
    9. metadata-eval100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{-2 \cdot \frac{-2}{1 + t} + -2 \cdot \color{blue}{4}}{1 + t}\right)} \]
    10. metadata-eval100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{-2 \cdot \frac{-2}{1 + t} + \color{blue}{-8}}{1 + t}\right)} \]
    11. metadata-eval100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{-2 \cdot \frac{-2}{1 + t} + \color{blue}{{-2}^{3}}}{1 + t}\right)} \]
    12. fma-def100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{\color{blue}{\mathsf{fma}\left(-2, \frac{-2}{1 + t}, {-2}^{3}\right)}}{1 + t}\right)} \]
    13. metadata-eval100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{\mathsf{fma}\left(-2, \frac{-2}{1 + t}, \color{blue}{-8}\right)}{1 + t}\right)} \]
  5. Applied egg-rr100.0%

    \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\left(0 + \frac{\mathsf{fma}\left(-2, \frac{-2}{1 + t}, -8\right)}{1 + t}\right)}} \]
  6. Step-by-step derivation
    1. +-lft-identity100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\frac{\mathsf{fma}\left(-2, \frac{-2}{1 + t}, -8\right)}{1 + t}}} \]
    2. fma-udef100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\color{blue}{-2 \cdot \frac{-2}{1 + t} + -8}}{1 + t}} \]
    3. associate-*r/100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\color{blue}{\frac{-2 \cdot -2}{1 + t}} + -8}{1 + t}} \]
    4. metadata-eval100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\frac{\color{blue}{4}}{1 + t} + -8}{1 + t}} \]
    5. +-commutative100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\frac{4}{\color{blue}{t + 1}} + -8}{1 + t}} \]
    6. +-commutative100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\frac{4}{t + 1} + -8}{\color{blue}{t + 1}}} \]
  7. Simplified100.0%

    \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\frac{\frac{4}{t + 1} + -8}{t + 1}}} \]
  8. Step-by-step derivation
    1. add-log-exp100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\log \left(e^{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}\right)}} \]
    2. *-un-lft-identity100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \log \color{blue}{\left(1 \cdot e^{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}\right)}} \]
    3. log-prod100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\left(\log 1 + \log \left(e^{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}\right)\right)}} \]
    4. metadata-eval100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(\color{blue}{0} + \log \left(e^{\frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}\right)\right)} \]
    5. associate-*l/100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \log \left(e^{\color{blue}{\frac{-2 \cdot \left(\frac{-2}{1 + t} - -4\right)}{1 + t}}}\right)\right)} \]
    6. add-log-exp100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \color{blue}{\frac{-2 \cdot \left(\frac{-2}{1 + t} - -4\right)}{1 + t}}\right)} \]
    7. sub-neg100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{-2 \cdot \color{blue}{\left(\frac{-2}{1 + t} + \left(--4\right)\right)}}{1 + t}\right)} \]
    8. distribute-lft-in100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{\color{blue}{-2 \cdot \frac{-2}{1 + t} + -2 \cdot \left(--4\right)}}{1 + t}\right)} \]
    9. metadata-eval100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{-2 \cdot \frac{-2}{1 + t} + -2 \cdot \color{blue}{4}}{1 + t}\right)} \]
    10. metadata-eval100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{-2 \cdot \frac{-2}{1 + t} + \color{blue}{-8}}{1 + t}\right)} \]
    11. metadata-eval100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{-2 \cdot \frac{-2}{1 + t} + \color{blue}{{-2}^{3}}}{1 + t}\right)} \]
    12. fma-def100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{\color{blue}{\mathsf{fma}\left(-2, \frac{-2}{1 + t}, {-2}^{3}\right)}}{1 + t}\right)} \]
    13. metadata-eval100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \left(0 + \frac{\mathsf{fma}\left(-2, \frac{-2}{1 + t}, \color{blue}{-8}\right)}{1 + t}\right)} \]
  9. Applied egg-rr100.0%

    \[\leadsto \frac{5 + \color{blue}{\left(0 + \frac{\mathsf{fma}\left(-2, \frac{-2}{1 + t}, -8\right)}{1 + t}\right)}}{6 + \frac{\frac{4}{t + 1} + -8}{t + 1}} \]
  10. Step-by-step derivation
    1. +-lft-identity100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \color{blue}{\frac{\mathsf{fma}\left(-2, \frac{-2}{1 + t}, -8\right)}{1 + t}}} \]
    2. fma-udef100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\color{blue}{-2 \cdot \frac{-2}{1 + t} + -8}}{1 + t}} \]
    3. associate-*r/100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\color{blue}{\frac{-2 \cdot -2}{1 + t}} + -8}{1 + t}} \]
    4. metadata-eval100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\frac{\color{blue}{4}}{1 + t} + -8}{1 + t}} \]
    5. +-commutative100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\frac{4}{\color{blue}{t + 1}} + -8}{1 + t}} \]
    6. +-commutative100.0%

      \[\leadsto \frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{\frac{4}{t + 1} + -8}{\color{blue}{t + 1}}} \]
  11. Simplified100.0%

    \[\leadsto \frac{5 + \color{blue}{\frac{\frac{4}{t + 1} + -8}{t + 1}}}{6 + \frac{\frac{4}{t + 1} + -8}{t + 1}} \]
  12. Final simplification100.0%

    \[\leadsto \frac{5 + \frac{\frac{4}{1 + t} + -8}{1 + t}}{6 + \frac{\frac{4}{1 + t} + -8}{1 + t}} \]
  13. Add Preprocessing

Alternative 5: 99.0% accurate, 2.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq -0.49:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\ \mathbf{elif}\;t \leq 2:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{5 - \frac{8}{t}}{6 + \frac{-8}{t}}\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (<= t -0.49)
   (- 0.8333333333333334 (/ 0.2222222222222222 t))
   (if (<= t 2.0) 0.5 (/ (- 5.0 (/ 8.0 t)) (+ 6.0 (/ -8.0 t))))))
double code(double t) {
	double tmp;
	if (t <= -0.49) {
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	} else if (t <= 2.0) {
		tmp = 0.5;
	} else {
		tmp = (5.0 - (8.0 / t)) / (6.0 + (-8.0 / t));
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: tmp
    if (t <= (-0.49d0)) then
        tmp = 0.8333333333333334d0 - (0.2222222222222222d0 / t)
    else if (t <= 2.0d0) then
        tmp = 0.5d0
    else
        tmp = (5.0d0 - (8.0d0 / t)) / (6.0d0 + ((-8.0d0) / t))
    end if
    code = tmp
end function
public static double code(double t) {
	double tmp;
	if (t <= -0.49) {
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	} else if (t <= 2.0) {
		tmp = 0.5;
	} else {
		tmp = (5.0 - (8.0 / t)) / (6.0 + (-8.0 / t));
	}
	return tmp;
}
def code(t):
	tmp = 0
	if t <= -0.49:
		tmp = 0.8333333333333334 - (0.2222222222222222 / t)
	elif t <= 2.0:
		tmp = 0.5
	else:
		tmp = (5.0 - (8.0 / t)) / (6.0 + (-8.0 / t))
	return tmp
function code(t)
	tmp = 0.0
	if (t <= -0.49)
		tmp = Float64(0.8333333333333334 - Float64(0.2222222222222222 / t));
	elseif (t <= 2.0)
		tmp = 0.5;
	else
		tmp = Float64(Float64(5.0 - Float64(8.0 / t)) / Float64(6.0 + Float64(-8.0 / t)));
	end
	return tmp
end
function tmp_2 = code(t)
	tmp = 0.0;
	if (t <= -0.49)
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	elseif (t <= 2.0)
		tmp = 0.5;
	else
		tmp = (5.0 - (8.0 / t)) / (6.0 + (-8.0 / t));
	end
	tmp_2 = tmp;
end
code[t_] := If[LessEqual[t, -0.49], N[(0.8333333333333334 - N[(0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision], If[LessEqual[t, 2.0], 0.5, N[(N[(5.0 - N[(8.0 / t), $MachinePrecision]), $MachinePrecision] / N[(6.0 + N[(-8.0 / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.49:\\
\;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\

\mathbf{elif}\;t \leq 2:\\
\;\;\;\;0.5\\

\mathbf{else}:\\
\;\;\;\;\frac{5 - \frac{8}{t}}{6 + \frac{-8}{t}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if t < -0.48999999999999999

    1. Initial program 100.0%

      \[\frac{1 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{\frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around inf 96.8%

      \[\leadsto \frac{\color{blue}{5 - 8 \cdot \frac{1}{t}}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
    5. Step-by-step derivation
      1. associate-*r/96.8%

        \[\leadsto \frac{5 - \color{blue}{\frac{8 \cdot 1}{t}}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
      2. metadata-eval96.8%

        \[\leadsto \frac{5 - \frac{\color{blue}{8}}{t}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
    6. Simplified96.8%

      \[\leadsto \frac{\color{blue}{5 - \frac{8}{t}}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
    7. Taylor expanded in t around inf 97.1%

      \[\leadsto \color{blue}{0.8333333333333334 - 0.2222222222222222 \cdot \frac{1}{t}} \]
    8. Step-by-step derivation
      1. associate-*r/97.1%

        \[\leadsto 0.8333333333333334 - \color{blue}{\frac{0.2222222222222222 \cdot 1}{t}} \]
      2. metadata-eval97.1%

        \[\leadsto 0.8333333333333334 - \frac{\color{blue}{0.2222222222222222}}{t} \]
    9. Simplified97.1%

      \[\leadsto \color{blue}{0.8333333333333334 - \frac{0.2222222222222222}{t}} \]

    if -0.48999999999999999 < t < 2

    1. Initial program 99.2%

      \[\frac{1 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{\frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around 0 98.8%

      \[\leadsto \frac{\color{blue}{1}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
    5. Taylor expanded in t around 0 98.9%

      \[\leadsto \color{blue}{0.5} \]

    if 2 < t

    1. Initial program 100.0%

      \[\frac{1 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{\frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around inf 100.0%

      \[\leadsto \frac{\color{blue}{5 - 8 \cdot \frac{1}{t}}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
    5. Step-by-step derivation
      1. associate-*r/100.0%

        \[\leadsto \frac{5 - \color{blue}{\frac{8 \cdot 1}{t}}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
      2. metadata-eval100.0%

        \[\leadsto \frac{5 - \frac{\color{blue}{8}}{t}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
    6. Simplified100.0%

      \[\leadsto \frac{\color{blue}{5 - \frac{8}{t}}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
    7. Taylor expanded in t around inf 100.0%

      \[\leadsto \frac{5 - \frac{8}{t}}{6 + \color{blue}{\frac{-8}{t}}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification98.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -0.49:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\ \mathbf{elif}\;t \leq 2:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{5 - \frac{8}{t}}{6 + \frac{-8}{t}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 99.0% accurate, 3.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq -0.49 \lor \neg \left(t \leq 0.68\right):\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\ \mathbf{else}:\\ \;\;\;\;0.5\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (or (<= t -0.49) (not (<= t 0.68)))
   (- 0.8333333333333334 (/ 0.2222222222222222 t))
   0.5))
double code(double t) {
	double tmp;
	if ((t <= -0.49) || !(t <= 0.68)) {
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	} else {
		tmp = 0.5;
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: tmp
    if ((t <= (-0.49d0)) .or. (.not. (t <= 0.68d0))) then
        tmp = 0.8333333333333334d0 - (0.2222222222222222d0 / t)
    else
        tmp = 0.5d0
    end if
    code = tmp
end function
public static double code(double t) {
	double tmp;
	if ((t <= -0.49) || !(t <= 0.68)) {
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	} else {
		tmp = 0.5;
	}
	return tmp;
}
def code(t):
	tmp = 0
	if (t <= -0.49) or not (t <= 0.68):
		tmp = 0.8333333333333334 - (0.2222222222222222 / t)
	else:
		tmp = 0.5
	return tmp
function code(t)
	tmp = 0.0
	if ((t <= -0.49) || !(t <= 0.68))
		tmp = Float64(0.8333333333333334 - Float64(0.2222222222222222 / t));
	else
		tmp = 0.5;
	end
	return tmp
end
function tmp_2 = code(t)
	tmp = 0.0;
	if ((t <= -0.49) || ~((t <= 0.68)))
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	else
		tmp = 0.5;
	end
	tmp_2 = tmp;
end
code[t_] := If[Or[LessEqual[t, -0.49], N[Not[LessEqual[t, 0.68]], $MachinePrecision]], N[(0.8333333333333334 - N[(0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision], 0.5]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.49 \lor \neg \left(t \leq 0.68\right):\\
\;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\

\mathbf{else}:\\
\;\;\;\;0.5\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < -0.48999999999999999 or 0.680000000000000049 < t

    1. Initial program 100.0%

      \[\frac{1 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{\frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around inf 98.5%

      \[\leadsto \frac{\color{blue}{5 - 8 \cdot \frac{1}{t}}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
    5. Step-by-step derivation
      1. associate-*r/98.5%

        \[\leadsto \frac{5 - \color{blue}{\frac{8 \cdot 1}{t}}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
      2. metadata-eval98.5%

        \[\leadsto \frac{5 - \frac{\color{blue}{8}}{t}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
    6. Simplified98.5%

      \[\leadsto \frac{\color{blue}{5 - \frac{8}{t}}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
    7. Taylor expanded in t around inf 98.7%

      \[\leadsto \color{blue}{0.8333333333333334 - 0.2222222222222222 \cdot \frac{1}{t}} \]
    8. Step-by-step derivation
      1. associate-*r/98.7%

        \[\leadsto 0.8333333333333334 - \color{blue}{\frac{0.2222222222222222 \cdot 1}{t}} \]
      2. metadata-eval98.7%

        \[\leadsto 0.8333333333333334 - \frac{\color{blue}{0.2222222222222222}}{t} \]
    9. Simplified98.7%

      \[\leadsto \color{blue}{0.8333333333333334 - \frac{0.2222222222222222}{t}} \]

    if -0.48999999999999999 < t < 0.680000000000000049

    1. Initial program 99.2%

      \[\frac{1 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{\frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around 0 98.8%

      \[\leadsto \frac{\color{blue}{1}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
    5. Taylor expanded in t around 0 98.9%

      \[\leadsto \color{blue}{0.5} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -0.49 \lor \neg \left(t \leq 0.68\right):\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\ \mathbf{else}:\\ \;\;\;\;0.5\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 98.5% accurate, 4.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq -0.34:\\ \;\;\;\;0.8333333333333334\\ \mathbf{elif}\;t \leq 1:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (<= t -0.34) 0.8333333333333334 (if (<= t 1.0) 0.5 0.8333333333333334)))
double code(double t) {
	double tmp;
	if (t <= -0.34) {
		tmp = 0.8333333333333334;
	} else if (t <= 1.0) {
		tmp = 0.5;
	} else {
		tmp = 0.8333333333333334;
	}
	return tmp;
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: tmp
    if (t <= (-0.34d0)) then
        tmp = 0.8333333333333334d0
    else if (t <= 1.0d0) then
        tmp = 0.5d0
    else
        tmp = 0.8333333333333334d0
    end if
    code = tmp
end function
public static double code(double t) {
	double tmp;
	if (t <= -0.34) {
		tmp = 0.8333333333333334;
	} else if (t <= 1.0) {
		tmp = 0.5;
	} else {
		tmp = 0.8333333333333334;
	}
	return tmp;
}
def code(t):
	tmp = 0
	if t <= -0.34:
		tmp = 0.8333333333333334
	elif t <= 1.0:
		tmp = 0.5
	else:
		tmp = 0.8333333333333334
	return tmp
function code(t)
	tmp = 0.0
	if (t <= -0.34)
		tmp = 0.8333333333333334;
	elseif (t <= 1.0)
		tmp = 0.5;
	else
		tmp = 0.8333333333333334;
	end
	return tmp
end
function tmp_2 = code(t)
	tmp = 0.0;
	if (t <= -0.34)
		tmp = 0.8333333333333334;
	elseif (t <= 1.0)
		tmp = 0.5;
	else
		tmp = 0.8333333333333334;
	end
	tmp_2 = tmp;
end
code[t_] := If[LessEqual[t, -0.34], 0.8333333333333334, If[LessEqual[t, 1.0], 0.5, 0.8333333333333334]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.34:\\
\;\;\;\;0.8333333333333334\\

\mathbf{elif}\;t \leq 1:\\
\;\;\;\;0.5\\

\mathbf{else}:\\
\;\;\;\;0.8333333333333334\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < -0.340000000000000024 or 1 < t

    1. Initial program 100.0%

      \[\frac{1 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{\frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around inf 98.5%

      \[\leadsto \frac{\color{blue}{5 - 8 \cdot \frac{1}{t}}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
    5. Step-by-step derivation
      1. associate-*r/98.5%

        \[\leadsto \frac{5 - \color{blue}{\frac{8 \cdot 1}{t}}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
      2. metadata-eval98.5%

        \[\leadsto \frac{5 - \frac{\color{blue}{8}}{t}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
    6. Simplified98.5%

      \[\leadsto \frac{\color{blue}{5 - \frac{8}{t}}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
    7. Taylor expanded in t around inf 98.0%

      \[\leadsto \color{blue}{0.8333333333333334} \]

    if -0.340000000000000024 < t < 1

    1. Initial program 99.2%

      \[\frac{1 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{\frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around 0 98.8%

      \[\leadsto \frac{\color{blue}{1}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
    5. Taylor expanded in t around 0 98.9%

      \[\leadsto \color{blue}{0.5} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -0.34:\\ \;\;\;\;0.8333333333333334\\ \mathbf{elif}\;t \leq 1:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334\\ \end{array} \]
  5. Add Preprocessing

Alternative 8: 58.3% accurate, 51.0× speedup?

\[\begin{array}{l} \\ 0.5 \end{array} \]
(FPCore (t) :precision binary64 0.5)
double code(double t) {
	return 0.5;
}
real(8) function code(t)
    real(8), intent (in) :: t
    code = 0.5d0
end function
public static double code(double t) {
	return 0.5;
}
def code(t):
	return 0.5
function code(t)
	return 0.5
end
function tmp = code(t)
	tmp = 0.5;
end
code[t_] := 0.5
\begin{array}{l}

\\
0.5
\end{array}
Derivation
  1. Initial program 99.6%

    \[\frac{1 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)} \]
  2. Simplified100.0%

    \[\leadsto \color{blue}{\frac{5 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)}} \]
  3. Add Preprocessing
  4. Taylor expanded in t around 0 55.9%

    \[\leadsto \frac{\color{blue}{1}}{6 + \frac{-2}{1 + t} \cdot \left(\frac{-2}{1 + t} - -4\right)} \]
  5. Taylor expanded in t around 0 57.4%

    \[\leadsto \color{blue}{0.5} \]
  6. Final simplification57.4%

    \[\leadsto 0.5 \]
  7. Add Preprocessing

Reproduce

?
herbie shell --seed 2024024 
(FPCore (t)
  :name "Kahan p13 Example 2"
  :precision binary64
  (/ (+ 1.0 (* (- 2.0 (/ (/ 2.0 t) (+ 1.0 (/ 1.0 t)))) (- 2.0 (/ (/ 2.0 t) (+ 1.0 (/ 1.0 t)))))) (+ 2.0 (* (- 2.0 (/ (/ 2.0 t) (+ 1.0 (/ 1.0 t)))) (- 2.0 (/ (/ 2.0 t) (+ 1.0 (/ 1.0 t))))))))