Kahan p13 Example 1

Percentage Accurate: 100.0% → 100.0%

Time: 13.8s

Alternatives: 5

Speedup: N/A×

Specification

Math

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{2 \cdot t}{1 + t}\\ t_2 := t\_1 \cdot t\_1\\ \frac{1 + t\_2}{2 + t\_2} \end{array} \end{array} \]

FPCore

(FPCore (t)
 :precision binary64
 (let* ((t_1 (/ (* 2.0 t) (+ 1.0 t))) (t_2 (* t_1 t_1)))
   (/ (+ 1.0 t_2) (+ 2.0 t_2))))

C

double code(double t) {
	double t_1 = (2.0 * t) / (1.0 + t);
	double t_2 = t_1 * t_1;
	return (1.0 + t_2) / (2.0 + t_2);
}

Fortran

real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: t_2
    t_1 = (2.0d0 * t) / (1.0d0 + t)
    t_2 = t_1 * t_1
    code = (1.0d0 + t_2) / (2.0d0 + t_2)
end function

Java

public static double code(double t) {
	double t_1 = (2.0 * t) / (1.0 + t);
	double t_2 = t_1 * t_1;
	return (1.0 + t_2) / (2.0 + t_2);
}

Python

def code(t):
	t_1 = (2.0 * t) / (1.0 + t)
	t_2 = t_1 * t_1
	return (1.0 + t_2) / (2.0 + t_2)

Julia

function code(t)
	t_1 = Float64(Float64(2.0 * t) / Float64(1.0 + t))
	t_2 = Float64(t_1 * t_1)
	return Float64(Float64(1.0 + t_2) / Float64(2.0 + t_2))
end

MATLAB

function tmp = code(t)
	t_1 = (2.0 * t) / (1.0 + t);
	t_2 = t_1 * t_1;
	tmp = (1.0 + t_2) / (2.0 + t_2);
end

Wolfram

code[t_] := Block[{t$95$1 = N[(N[(2.0 * t), $MachinePrecision] / N[(1.0 + t), $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]]]

Initial Program: 100.0% accurate, 1.0× speedup

Math

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{2 \cdot t}{1 + t}\\ t_2 := t\_1 \cdot t\_1\\ \frac{1 + t\_2}{2 + t\_2} \end{array} \end{array} \]

FPCore

(FPCore (t)
 :precision binary64
 (let* ((t_1 (/ (* 2.0 t) (+ 1.0 t))) (t_2 (* t_1 t_1)))
   (/ (+ 1.0 t_2) (+ 2.0 t_2))))

C

double code(double t) {
	double t_1 = (2.0 * t) / (1.0 + t);
	double t_2 = t_1 * t_1;
	return (1.0 + t_2) / (2.0 + t_2);
}

Fortran

real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: t_2
    t_1 = (2.0d0 * t) / (1.0d0 + t)
    t_2 = t_1 * t_1
    code = (1.0d0 + t_2) / (2.0d0 + t_2)
end function

Java

public static double code(double t) {
	double t_1 = (2.0 * t) / (1.0 + t);
	double t_2 = t_1 * t_1;
	return (1.0 + t_2) / (2.0 + t_2);
}

Python

def code(t):
	t_1 = (2.0 * t) / (1.0 + t)
	t_2 = t_1 * t_1
	return (1.0 + t_2) / (2.0 + t_2)

Julia

function code(t)
	t_1 = Float64(Float64(2.0 * t) / Float64(1.0 + t))
	t_2 = Float64(t_1 * t_1)
	return Float64(Float64(1.0 + t_2) / Float64(2.0 + t_2))
end

MATLAB

function tmp = code(t)
	t_1 = (2.0 * t) / (1.0 + t);
	t_2 = t_1 * t_1;
	tmp = (1.0 + t_2) / (2.0 + t_2);
end

Wolfram

code[t_] := Block[{t$95$1 = N[(N[(2.0 * t), $MachinePrecision] / N[(1.0 + t), $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]]]

Alternative 1: 100.0% accurate, 1.1× speedup

Math

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}\\ \frac{1 + t\_1}{t\_1 + 2} \end{array} \end{array} \]

FPCore

(FPCore (t)
 :precision binary64
 (let* ((t_1 (/ (/ (* t 4.0) (/ (+ 1.0 t) t)) (+ 1.0 t))))
   (/ (+ 1.0 t_1) (+ t_1 2.0))))

C

double code(double t) {
	double t_1 = ((t * 4.0) / ((1.0 + t) / t)) / (1.0 + t);
	return (1.0 + t_1) / (t_1 + 2.0);
}

Fortran

real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    t_1 = ((t * 4.0d0) / ((1.0d0 + t) / t)) / (1.0d0 + t)
    code = (1.0d0 + t_1) / (t_1 + 2.0d0)
end function

Java

public static double code(double t) {
	double t_1 = ((t * 4.0) / ((1.0 + t) / t)) / (1.0 + t);
	return (1.0 + t_1) / (t_1 + 2.0);
}

Python

def code(t):
	t_1 = ((t * 4.0) / ((1.0 + t) / t)) / (1.0 + t)
	return (1.0 + t_1) / (t_1 + 2.0)

Julia

function code(t)
	t_1 = Float64(Float64(Float64(t * 4.0) / Float64(Float64(1.0 + t) / t)) / Float64(1.0 + t))
	return Float64(Float64(1.0 + t_1) / Float64(t_1 + 2.0))
end

MATLAB

function tmp = code(t)
	t_1 = ((t * 4.0) / ((1.0 + t) / t)) / (1.0 + t);
	tmp = (1.0 + t_1) / (t_1 + 2.0);
end

Wolfram

code[t_] := Block[{t$95$1 = N[(N[(N[(t * 4.0), $MachinePrecision] / N[(N[(1.0 + t), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision] / N[(1.0 + t), $MachinePrecision]), $MachinePrecision]}, N[(N[(1.0 + t$95$1), $MachinePrecision] / N[(t$95$1 + 2.0), $MachinePrecision]), $MachinePrecision]]

Derivation

1. Initial program 100.0%

   \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
2. Step-by-step derivation

   1. associate-*r/ 100.0%

      \[\leadsto \frac{1 + \color{blue}{\frac{\frac{2 \cdot t}{1 + t} \cdot \left(2 \cdot t\right)}{1 + t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   2. associate-*r* 100.0%

      \[\leadsto \frac{1 + \frac{\color{blue}{\left(\frac{2 \cdot t}{1 + t} \cdot 2\right) \cdot t}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   3. *-commutative 100.0%

      \[\leadsto \frac{1 + \frac{\color{blue}{t \cdot \left(\frac{2 \cdot t}{1 + t} \cdot 2\right)}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   4. associate-/l* 100.0%

      \[\leadsto \frac{1 + \frac{t \cdot \left(\color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot 2\right)}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   5. associate-*l/ 100.0%

      \[\leadsto \frac{1 + \frac{t \cdot \color{blue}{\frac{2 \cdot 2}{\frac{1 + t}{t}}}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   6. associate-*r/ 100.0%

      \[\leadsto \frac{1 + \frac{\color{blue}{\frac{t \cdot \left(2 \cdot 2\right)}{\frac{1 + t}{t}}}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   7. metadata-eval 100.0%

      \[\leadsto \frac{1 + \frac{\frac{t \cdot \color{blue}{4}}{\frac{1 + t}{t}}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   8. associate-*r/ 100.0%

      \[\leadsto \frac{1 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}{2 + \color{blue}{\frac{\frac{2 \cdot t}{1 + t} \cdot \left(2 \cdot t\right)}{1 + t}}} \]

3. Simplified 100.0%

   \[\leadsto \color{blue}{\frac{1 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}{2 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}} \]
4. Add Preprocessing

5. Final simplification 100.0%

   \[\leadsto \frac{1 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}{\frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t} + 2} \]
6. Add Preprocessing

Alternative 2: 97.9% accurate, 1.4× speedup

Math

\[\begin{array}{l} \\ \frac{1 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}{2 + \frac{t \cdot 4}{1 + t}} \end{array} \]

FPCore

(FPCore (t)
 :precision binary64
 (/
  (+ 1.0 (/ (/ (* t 4.0) (/ (+ 1.0 t) t)) (+ 1.0 t)))
  (+ 2.0 (/ (* t 4.0) (+ 1.0 t)))))

C

double code(double t) {
	return (1.0 + (((t * 4.0) / ((1.0 + t) / t)) / (1.0 + t))) / (2.0 + ((t * 4.0) / (1.0 + t)));
}

Fortran

real(8) function code(t)
    real(8), intent (in) :: t
    code = (1.0d0 + (((t * 4.0d0) / ((1.0d0 + t) / t)) / (1.0d0 + t))) / (2.0d0 + ((t * 4.0d0) / (1.0d0 + t)))
end function

Java

public static double code(double t) {
	return (1.0 + (((t * 4.0) / ((1.0 + t) / t)) / (1.0 + t))) / (2.0 + ((t * 4.0) / (1.0 + t)));
}

Python

def code(t):
	return (1.0 + (((t * 4.0) / ((1.0 + t) / t)) / (1.0 + t))) / (2.0 + ((t * 4.0) / (1.0 + t)))

Julia

function code(t)
	return Float64(Float64(1.0 + Float64(Float64(Float64(t * 4.0) / Float64(Float64(1.0 + t) / t)) / Float64(1.0 + t))) / Float64(2.0 + Float64(Float64(t * 4.0) / Float64(1.0 + t))))
end

MATLAB

function tmp = code(t)
	tmp = (1.0 + (((t * 4.0) / ((1.0 + t) / t)) / (1.0 + t))) / (2.0 + ((t * 4.0) / (1.0 + t)));
end

Wolfram

code[t_] := N[(N[(1.0 + N[(N[(N[(t * 4.0), $MachinePrecision] / N[(N[(1.0 + t), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision] / N[(1.0 + t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(2.0 + N[(N[(t * 4.0), $MachinePrecision] / N[(1.0 + t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]

Derivation

1. Initial program 100.0%

   \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
2. Step-by-step derivation

   1. associate-*r/ 100.0%

      \[\leadsto \frac{1 + \color{blue}{\frac{\frac{2 \cdot t}{1 + t} \cdot \left(2 \cdot t\right)}{1 + t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   2. associate-*r* 100.0%

      \[\leadsto \frac{1 + \frac{\color{blue}{\left(\frac{2 \cdot t}{1 + t} \cdot 2\right) \cdot t}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   3. *-commutative 100.0%

      \[\leadsto \frac{1 + \frac{\color{blue}{t \cdot \left(\frac{2 \cdot t}{1 + t} \cdot 2\right)}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   4. associate-/l* 100.0%

      \[\leadsto \frac{1 + \frac{t \cdot \left(\color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot 2\right)}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   5. associate-*l/ 100.0%

      \[\leadsto \frac{1 + \frac{t \cdot \color{blue}{\frac{2 \cdot 2}{\frac{1 + t}{t}}}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   6. associate-*r/ 100.0%

      \[\leadsto \frac{1 + \frac{\color{blue}{\frac{t \cdot \left(2 \cdot 2\right)}{\frac{1 + t}{t}}}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   7. metadata-eval 100.0%

      \[\leadsto \frac{1 + \frac{\frac{t \cdot \color{blue}{4}}{\frac{1 + t}{t}}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   8. associate-*r/ 100.0%

      \[\leadsto \frac{1 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}{2 + \color{blue}{\frac{\frac{2 \cdot t}{1 + t} \cdot \left(2 \cdot t\right)}{1 + t}}} \]

3. Simplified 100.0%

   \[\leadsto \color{blue}{\frac{1 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}{2 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}} \]
4. Add Preprocessing

5. Taylor expanded in t around inf 98.2%

   \[\leadsto \frac{1 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}{2 + \frac{\color{blue}{4 \cdot t}}{1 + t}} \]

6. Final simplification 98.2%

   \[\leadsto \frac{1 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}{2 + \frac{t \cdot 4}{1 + t}} \]
7. Add Preprocessing

Alternative 3: 59.1% accurate, 3.2× speedup

Math

\[\begin{array}{l} \\ \frac{5 - \frac{8}{t}}{6 - \frac{8}{t}} \end{array} \]

FPCore

(FPCore (t) :precision binary64 (/ (- 5.0 (/ 8.0 t)) (- 6.0 (/ 8.0 t))))

C

double code(double t) {
	return (5.0 - (8.0 / t)) / (6.0 - (8.0 / t));
}

Fortran

real(8) function code(t)
    real(8), intent (in) :: t
    code = (5.0d0 - (8.0d0 / t)) / (6.0d0 - (8.0d0 / t))
end function

Java

public static double code(double t) {
	return (5.0 - (8.0 / t)) / (6.0 - (8.0 / t));
}

Python

def code(t):
	return (5.0 - (8.0 / t)) / (6.0 - (8.0 / t))

Julia

function code(t)
	return Float64(Float64(5.0 - Float64(8.0 / t)) / Float64(6.0 - Float64(8.0 / t)))
end

MATLAB

function tmp = code(t)
	tmp = (5.0 - (8.0 / t)) / (6.0 - (8.0 / t));
end

Wolfram

code[t_] := N[(N[(5.0 - N[(8.0 / t), $MachinePrecision]), $MachinePrecision] / N[(6.0 - N[(8.0 / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]

Derivation

1. Initial program 100.0%

   \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
2. Step-by-step derivation

   1. associate-*r/ 100.0%

      \[\leadsto \frac{1 + \color{blue}{\frac{\frac{2 \cdot t}{1 + t} \cdot \left(2 \cdot t\right)}{1 + t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   2. associate-*r* 100.0%

      \[\leadsto \frac{1 + \frac{\color{blue}{\left(\frac{2 \cdot t}{1 + t} \cdot 2\right) \cdot t}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   3. *-commutative 100.0%

      \[\leadsto \frac{1 + \frac{\color{blue}{t \cdot \left(\frac{2 \cdot t}{1 + t} \cdot 2\right)}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   4. associate-/l* 100.0%

      \[\leadsto \frac{1 + \frac{t \cdot \left(\color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot 2\right)}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   5. associate-*l/ 100.0%

      \[\leadsto \frac{1 + \frac{t \cdot \color{blue}{\frac{2 \cdot 2}{\frac{1 + t}{t}}}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   6. associate-*r/ 100.0%

      \[\leadsto \frac{1 + \frac{\color{blue}{\frac{t \cdot \left(2 \cdot 2\right)}{\frac{1 + t}{t}}}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   7. metadata-eval 100.0%

      \[\leadsto \frac{1 + \frac{\frac{t \cdot \color{blue}{4}}{\frac{1 + t}{t}}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   8. associate-*r/ 100.0%

      \[\leadsto \frac{1 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}{2 + \color{blue}{\frac{\frac{2 \cdot t}{1 + t} \cdot \left(2 \cdot t\right)}{1 + t}}} \]

3. Simplified 100.0%

   \[\leadsto \color{blue}{\frac{1 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}{2 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}} \]
4. Add Preprocessing

5. Taylor expanded in t around inf 48.7%

   \[\leadsto \frac{\color{blue}{5 - 8 \cdot \frac{1}{t}}}{2 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}} \]
6. Step-by-step derivation

   1. associate-*r/ 48.7%

      \[\leadsto \frac{5 - \color{blue}{\frac{8 \cdot 1}{t}}}{2 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}} \]

   2. metadata-eval 48.7%

      \[\leadsto \frac{5 - \frac{\color{blue}{8}}{t}}{2 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}} \]

7. Simplified 48.7%

   \[\leadsto \frac{\color{blue}{5 - \frac{8}{t}}}{2 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}} \]

8. Taylor expanded in t around inf 56.9%

   \[\leadsto \frac{5 - \frac{8}{t}}{\color{blue}{6 - 8 \cdot \frac{1}{t}}} \]
9. Step-by-step derivation

   1. associate-*r/ 56.9%

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

   2. metadata-eval 56.9%

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

10. Simplified 56.9%

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

11. Final simplification 56.9%

    \[\leadsto \frac{5 - \frac{8}{t}}{6 - \frac{8}{t}} \]
12. Add Preprocessing

Alternative 4: 59.0% accurate, 35.0× speedup

Math

\[\begin{array}{l} \\ 0.5 \end{array} \]

FPCore

(FPCore (t) :precision binary64 0.5)

C

double code(double t) {
	return 0.5;
}

Fortran

real(8) function code(t)
    real(8), intent (in) :: t
    code = 0.5d0
end function

Java

public static double code(double t) {
	return 0.5;
}

Python

def code(t):
	return 0.5

Julia

function code(t)
	return 0.5
end

MATLAB

function tmp = code(t)
	tmp = 0.5;
end

Wolfram

code[t_] := 0.5

Derivation

1. Initial program 100.0%

   \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
2. Step-by-step derivation

   1. associate-*r/ 100.0%

      \[\leadsto \frac{1 + \color{blue}{\frac{\frac{2 \cdot t}{1 + t} \cdot \left(2 \cdot t\right)}{1 + t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   2. associate-*r* 100.0%

      \[\leadsto \frac{1 + \frac{\color{blue}{\left(\frac{2 \cdot t}{1 + t} \cdot 2\right) \cdot t}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   3. *-commutative 100.0%

      \[\leadsto \frac{1 + \frac{\color{blue}{t \cdot \left(\frac{2 \cdot t}{1 + t} \cdot 2\right)}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   4. associate-/l* 100.0%

      \[\leadsto \frac{1 + \frac{t \cdot \left(\color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot 2\right)}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   5. associate-*l/ 100.0%

      \[\leadsto \frac{1 + \frac{t \cdot \color{blue}{\frac{2 \cdot 2}{\frac{1 + t}{t}}}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   6. associate-*r/ 100.0%

      \[\leadsto \frac{1 + \frac{\color{blue}{\frac{t \cdot \left(2 \cdot 2\right)}{\frac{1 + t}{t}}}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   7. metadata-eval 100.0%

      \[\leadsto \frac{1 + \frac{\frac{t \cdot \color{blue}{4}}{\frac{1 + t}{t}}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   8. associate-*r/ 100.0%

      \[\leadsto \frac{1 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}{2 + \color{blue}{\frac{\frac{2 \cdot t}{1 + t} \cdot \left(2 \cdot t\right)}{1 + t}}} \]

3. Simplified 100.0%

   \[\leadsto \color{blue}{\frac{1 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}{2 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}} \]
4. Add Preprocessing

5. Taylor expanded in t around inf 98.2%

   \[\leadsto \frac{1 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}{2 + \frac{\color{blue}{4 \cdot t}}{1 + t}} \]

6. Taylor expanded in t around 0 61.5%

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

7. Final simplification 61.5%

   \[\leadsto 0.5 \]
8. Add Preprocessing

Alternative 5: 59.1% accurate, 35.0× speedup

Math

\[\begin{array}{l} \\ 0.8333333333333334 \end{array} \]

FPCore

(FPCore (t) :precision binary64 0.8333333333333334)

C

double code(double t) {
	return 0.8333333333333334;
}

Fortran

real(8) function code(t)
    real(8), intent (in) :: t
    code = 0.8333333333333334d0
end function

Java

public static double code(double t) {
	return 0.8333333333333334;
}

Python

def code(t):
	return 0.8333333333333334

Julia

function code(t)
	return 0.8333333333333334
end

MATLAB

function tmp = code(t)
	tmp = 0.8333333333333334;
end

Wolfram

code[t_] := 0.8333333333333334

Derivation

1. Initial program 100.0%

   \[\frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
2. Step-by-step derivation

   1. associate-*r/ 100.0%

      \[\leadsto \frac{1 + \color{blue}{\frac{\frac{2 \cdot t}{1 + t} \cdot \left(2 \cdot t\right)}{1 + t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   2. associate-*r* 100.0%

      \[\leadsto \frac{1 + \frac{\color{blue}{\left(\frac{2 \cdot t}{1 + t} \cdot 2\right) \cdot t}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   3. *-commutative 100.0%

      \[\leadsto \frac{1 + \frac{\color{blue}{t \cdot \left(\frac{2 \cdot t}{1 + t} \cdot 2\right)}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   4. associate-/l* 100.0%

      \[\leadsto \frac{1 + \frac{t \cdot \left(\color{blue}{\frac{2}{\frac{1 + t}{t}}} \cdot 2\right)}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   5. associate-*l/ 100.0%

      \[\leadsto \frac{1 + \frac{t \cdot \color{blue}{\frac{2 \cdot 2}{\frac{1 + t}{t}}}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   6. associate-*r/ 100.0%

      \[\leadsto \frac{1 + \frac{\color{blue}{\frac{t \cdot \left(2 \cdot 2\right)}{\frac{1 + t}{t}}}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   7. metadata-eval 100.0%

      \[\leadsto \frac{1 + \frac{\frac{t \cdot \color{blue}{4}}{\frac{1 + t}{t}}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]

   8. associate-*r/ 100.0%

      \[\leadsto \frac{1 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}{2 + \color{blue}{\frac{\frac{2 \cdot t}{1 + t} \cdot \left(2 \cdot t\right)}{1 + t}}} \]

3. Simplified 100.0%

   \[\leadsto \color{blue}{\frac{1 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}{2 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}} \]
4. Add Preprocessing

5. Taylor expanded in t around inf 98.2%

   \[\leadsto \frac{1 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}{2 + \frac{\color{blue}{4 \cdot t}}{1 + t}} \]

6. Taylor expanded in t around inf 57.1%

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

7. Final simplification 57.1%

   \[\leadsto 0.8333333333333334 \]
8. Add Preprocessing

Reproduce

herbie shell --seed 2024033 
(FPCore (t)
  :name "Kahan p13 Example 1"
  :precision binary64
  (/ (+ 1.0 (* (/ (* 2.0 t) (+ 1.0 t)) (/ (* 2.0 t) (+ 1.0 t)))) (+ 2.0 (* (/ (* 2.0 t) (+ 1.0 t)) (/ (* 2.0 t) (+ 1.0 t))))))