Kahan p13 Example 1

Percentage Accurate: 100.0% → 100.0%
Time: 12.8s
Alternatives: 10
Speedup: 1.0×

Specification

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

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 10 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: 100.0% accurate, 1.0× speedup?

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

Alternative 1: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{2 \cdot t}{t + 1}\\ t_2 := t\_1 \cdot t\_1\\ \frac{t\_2 + 1}{2 + t\_2} \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (/ (* 2.0 t) (+ t 1.0))) (t_2 (* t_1 t_1)))
   (/ (+ t_2 1.0) (+ 2.0 t_2))))
double code(double t) {
	double t_1 = (2.0 * t) / (t + 1.0);
	double t_2 = t_1 * t_1;
	return (t_2 + 1.0) / (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 * t) / (t + 1.0d0)
    t_2 = t_1 * t_1
    code = (t_2 + 1.0d0) / (2.0d0 + t_2)
end function
public static double code(double t) {
	double t_1 = (2.0 * t) / (t + 1.0);
	double t_2 = t_1 * t_1;
	return (t_2 + 1.0) / (2.0 + t_2);
}
def code(t):
	t_1 = (2.0 * t) / (t + 1.0)
	t_2 = t_1 * t_1
	return (t_2 + 1.0) / (2.0 + t_2)
function code(t)
	t_1 = Float64(Float64(2.0 * t) / Float64(t + 1.0))
	t_2 = Float64(t_1 * t_1)
	return Float64(Float64(t_2 + 1.0) / Float64(2.0 + t_2))
end
function tmp = code(t)
	t_1 = (2.0 * t) / (t + 1.0);
	t_2 = t_1 * t_1;
	tmp = (t_2 + 1.0) / (2.0 + t_2);
end
code[t_] := Block[{t$95$1 = N[(N[(2.0 * t), $MachinePrecision] / N[(t + 1.0), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(t$95$1 * t$95$1), $MachinePrecision]}, N[(N[(t$95$2 + 1.0), $MachinePrecision] / N[(2.0 + t$95$2), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{2 \cdot t}{t + 1}\\
t_2 := t\_1 \cdot t\_1\\
\frac{t\_2 + 1}{2 + t\_2}
\end{array}
\end{array}
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. Add Preprocessing
  3. Final simplification100.0%

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

Alternative 2: 99.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{t \cdot \left(t \cdot 4\right)}{\left(t + 1\right) \cdot \left(t + 1\right)}\\ \mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 1.999999999:\\ \;\;\;\;\frac{t\_1 + 1}{2 + t\_1}\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 + \frac{\mathsf{fma}\left(t, -0.2222222222222222, 0.037037037037037035\right)}{t \cdot t}\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (/ (* t (* t 4.0)) (* (+ t 1.0) (+ t 1.0)))))
   (if (<= (/ (* 2.0 t) (+ t 1.0)) 1.999999999)
     (/ (+ t_1 1.0) (+ 2.0 t_1))
     (+
      0.8333333333333334
      (/ (fma t -0.2222222222222222 0.037037037037037035) (* t t))))))
double code(double t) {
	double t_1 = (t * (t * 4.0)) / ((t + 1.0) * (t + 1.0));
	double tmp;
	if (((2.0 * t) / (t + 1.0)) <= 1.999999999) {
		tmp = (t_1 + 1.0) / (2.0 + t_1);
	} else {
		tmp = 0.8333333333333334 + (fma(t, -0.2222222222222222, 0.037037037037037035) / (t * t));
	}
	return tmp;
}
function code(t)
	t_1 = Float64(Float64(t * Float64(t * 4.0)) / Float64(Float64(t + 1.0) * Float64(t + 1.0)))
	tmp = 0.0
	if (Float64(Float64(2.0 * t) / Float64(t + 1.0)) <= 1.999999999)
		tmp = Float64(Float64(t_1 + 1.0) / Float64(2.0 + t_1));
	else
		tmp = Float64(0.8333333333333334 + Float64(fma(t, -0.2222222222222222, 0.037037037037037035) / Float64(t * t)));
	end
	return tmp
end
code[t_] := Block[{t$95$1 = N[(N[(t * N[(t * 4.0), $MachinePrecision]), $MachinePrecision] / N[(N[(t + 1.0), $MachinePrecision] * N[(t + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(2.0 * t), $MachinePrecision] / N[(t + 1.0), $MachinePrecision]), $MachinePrecision], 1.999999999], N[(N[(t$95$1 + 1.0), $MachinePrecision] / N[(2.0 + t$95$1), $MachinePrecision]), $MachinePrecision], N[(0.8333333333333334 + N[(N[(t * -0.2222222222222222 + 0.037037037037037035), $MachinePrecision] / N[(t * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{t \cdot \left(t \cdot 4\right)}{\left(t + 1\right) \cdot \left(t + 1\right)}\\
\mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 1.999999999:\\
\;\;\;\;\frac{t\_1 + 1}{2 + t\_1}\\

\mathbf{else}:\\
\;\;\;\;0.8333333333333334 + \frac{\mathsf{fma}\left(t, -0.2222222222222222, 0.037037037037037035\right)}{t \cdot t}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (*.f64 #s(literal 2 binary64) t) (+.f64 #s(literal 1 binary64) t)) < 1.9999999989999999

    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. Add Preprocessing
    3. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{\color{blue}{1 + t}} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      2. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{\color{blue}{2 \cdot t}}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      3. frac-2negN/A

        \[\leadsto \frac{1 + \color{blue}{\frac{\mathsf{neg}\left(2 \cdot t\right)}{\mathsf{neg}\left(\left(1 + t\right)\right)}} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      4. lift-+.f64N/A

        \[\leadsto \frac{1 + \frac{\mathsf{neg}\left(2 \cdot t\right)}{\mathsf{neg}\left(\left(1 + t\right)\right)} \cdot \frac{2 \cdot t}{\color{blue}{1 + t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      5. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{\mathsf{neg}\left(2 \cdot t\right)}{\mathsf{neg}\left(\left(1 + t\right)\right)} \cdot \frac{\color{blue}{2 \cdot t}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      6. frac-2negN/A

        \[\leadsto \frac{1 + \color{blue}{\frac{2 \cdot t}{1 + t}} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      7. lift-/.f64N/A

        \[\leadsto \frac{1 + \color{blue}{\frac{2 \cdot t}{1 + t}} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      8. lift-/.f64N/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2 \cdot t}{1 + t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      9. lift-*.f64N/A

        \[\leadsto \frac{1 + \color{blue}{\frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      10. lift-+.f64N/A

        \[\leadsto \frac{\color{blue}{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      11. lift-+.f64N/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{\color{blue}{1 + t}} \cdot \frac{2 \cdot t}{1 + t}} \]
      12. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{\color{blue}{2 \cdot t}}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      13. frac-2negN/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \color{blue}{\frac{\mathsf{neg}\left(2 \cdot t\right)}{\mathsf{neg}\left(\left(1 + t\right)\right)}} \cdot \frac{2 \cdot t}{1 + t}} \]
    4. Applied rewrites100.0%

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

    if 1.9999999989999999 < (/.f64 (*.f64 #s(literal 2 binary64) t) (+.f64 #s(literal 1 binary64) t))

    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. Add Preprocessing
    3. Taylor expanded in t around inf

      \[\leadsto \color{blue}{\left(\frac{5}{6} + \frac{\frac{1}{27}}{{t}^{2}}\right) - \frac{2}{9} \cdot \frac{1}{t}} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \color{blue}{\left(\frac{\frac{1}{27}}{{t}^{2}} + \frac{5}{6}\right)} - \frac{2}{9} \cdot \frac{1}{t} \]
      2. associate--l+N/A

        \[\leadsto \color{blue}{\frac{\frac{1}{27}}{{t}^{2}} + \left(\frac{5}{6} - \frac{2}{9} \cdot \frac{1}{t}\right)} \]
      3. +-commutativeN/A

        \[\leadsto \color{blue}{\left(\frac{5}{6} - \frac{2}{9} \cdot \frac{1}{t}\right) + \frac{\frac{1}{27}}{{t}^{2}}} \]
      4. associate--r-N/A

        \[\leadsto \color{blue}{\frac{5}{6} - \left(\frac{2}{9} \cdot \frac{1}{t} - \frac{\frac{1}{27}}{{t}^{2}}\right)} \]
      5. associate-*r/N/A

        \[\leadsto \frac{5}{6} - \left(\color{blue}{\frac{\frac{2}{9} \cdot 1}{t}} - \frac{\frac{1}{27}}{{t}^{2}}\right) \]
      6. metadata-evalN/A

        \[\leadsto \frac{5}{6} - \left(\frac{\color{blue}{\frac{2}{9}}}{t} - \frac{\frac{1}{27}}{{t}^{2}}\right) \]
      7. unpow2N/A

        \[\leadsto \frac{5}{6} - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27}}{\color{blue}{t \cdot t}}\right) \]
      8. associate-/r*N/A

        \[\leadsto \frac{5}{6} - \left(\frac{\frac{2}{9}}{t} - \color{blue}{\frac{\frac{\frac{1}{27}}{t}}{t}}\right) \]
      9. metadata-evalN/A

        \[\leadsto \frac{5}{6} - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{\color{blue}{\frac{1}{27} \cdot 1}}{t}}{t}\right) \]
      10. associate-*r/N/A

        \[\leadsto \frac{5}{6} - \left(\frac{\frac{2}{9}}{t} - \frac{\color{blue}{\frac{1}{27} \cdot \frac{1}{t}}}{t}\right) \]
      11. div-subN/A

        \[\leadsto \frac{5}{6} - \color{blue}{\frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{t}} \]
      12. unsub-negN/A

        \[\leadsto \color{blue}{\frac{5}{6} + \left(\mathsf{neg}\left(\frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{t}\right)\right)} \]
      13. mul-1-negN/A

        \[\leadsto \frac{5}{6} + \color{blue}{-1 \cdot \frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{t}} \]
      14. lower-+.f64N/A

        \[\leadsto \color{blue}{\frac{5}{6} + -1 \cdot \frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{t}} \]
      15. associate-*r/N/A

        \[\leadsto \frac{5}{6} + \color{blue}{\frac{-1 \cdot \left(\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}\right)}{t}} \]
    5. Applied rewrites100.0%

      \[\leadsto \color{blue}{0.8333333333333334 + \frac{\frac{0.037037037037037035}{t} + -0.2222222222222222}{t}} \]
    6. Taylor expanded in t around 0

      \[\leadsto \frac{5}{6} + \color{blue}{\frac{\frac{1}{27} + \frac{-2}{9} \cdot t}{{t}^{2}}} \]
    7. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \frac{5}{6} + \color{blue}{\frac{\frac{1}{27} + \frac{-2}{9} \cdot t}{{t}^{2}}} \]
      2. +-commutativeN/A

        \[\leadsto \frac{5}{6} + \frac{\color{blue}{\frac{-2}{9} \cdot t + \frac{1}{27}}}{{t}^{2}} \]
      3. *-commutativeN/A

        \[\leadsto \frac{5}{6} + \frac{\color{blue}{t \cdot \frac{-2}{9}} + \frac{1}{27}}{{t}^{2}} \]
      4. lower-fma.f64N/A

        \[\leadsto \frac{5}{6} + \frac{\color{blue}{\mathsf{fma}\left(t, \frac{-2}{9}, \frac{1}{27}\right)}}{{t}^{2}} \]
      5. unpow2N/A

        \[\leadsto \frac{5}{6} + \frac{\mathsf{fma}\left(t, \frac{-2}{9}, \frac{1}{27}\right)}{\color{blue}{t \cdot t}} \]
      6. lower-*.f64100.0

        \[\leadsto 0.8333333333333334 + \frac{\mathsf{fma}\left(t, -0.2222222222222222, 0.037037037037037035\right)}{\color{blue}{t \cdot t}} \]
    8. Applied rewrites100.0%

      \[\leadsto 0.8333333333333334 + \color{blue}{\frac{\mathsf{fma}\left(t, -0.2222222222222222, 0.037037037037037035\right)}{t \cdot t}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification100.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 1.999999999:\\ \;\;\;\;\frac{\frac{t \cdot \left(t \cdot 4\right)}{\left(t + 1\right) \cdot \left(t + 1\right)} + 1}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(t + 1\right) \cdot \left(t + 1\right)}}\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 + \frac{\mathsf{fma}\left(t, -0.2222222222222222, 0.037037037037037035\right)}{t \cdot t}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 99.9% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{t}{\mathsf{fma}\left(t, 2 + t, 1\right)}\\ \mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 1.9999999999519582:\\ \;\;\;\;\frac{\mathsf{fma}\left(t \cdot 4, t\_1, 1\right)}{\mathsf{fma}\left(t \cdot 4, t\_1, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 + \frac{\mathsf{fma}\left(t, -0.2222222222222222, 0.037037037037037035\right)}{t \cdot t}\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (/ t (fma t (+ 2.0 t) 1.0))))
   (if (<= (/ (* 2.0 t) (+ t 1.0)) 1.9999999999519582)
     (/ (fma (* t 4.0) t_1 1.0) (fma (* t 4.0) t_1 2.0))
     (+
      0.8333333333333334
      (/ (fma t -0.2222222222222222 0.037037037037037035) (* t t))))))
double code(double t) {
	double t_1 = t / fma(t, (2.0 + t), 1.0);
	double tmp;
	if (((2.0 * t) / (t + 1.0)) <= 1.9999999999519582) {
		tmp = fma((t * 4.0), t_1, 1.0) / fma((t * 4.0), t_1, 2.0);
	} else {
		tmp = 0.8333333333333334 + (fma(t, -0.2222222222222222, 0.037037037037037035) / (t * t));
	}
	return tmp;
}
function code(t)
	t_1 = Float64(t / fma(t, Float64(2.0 + t), 1.0))
	tmp = 0.0
	if (Float64(Float64(2.0 * t) / Float64(t + 1.0)) <= 1.9999999999519582)
		tmp = Float64(fma(Float64(t * 4.0), t_1, 1.0) / fma(Float64(t * 4.0), t_1, 2.0));
	else
		tmp = Float64(0.8333333333333334 + Float64(fma(t, -0.2222222222222222, 0.037037037037037035) / Float64(t * t)));
	end
	return tmp
end
code[t_] := Block[{t$95$1 = N[(t / N[(t * N[(2.0 + t), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(2.0 * t), $MachinePrecision] / N[(t + 1.0), $MachinePrecision]), $MachinePrecision], 1.9999999999519582], N[(N[(N[(t * 4.0), $MachinePrecision] * t$95$1 + 1.0), $MachinePrecision] / N[(N[(t * 4.0), $MachinePrecision] * t$95$1 + 2.0), $MachinePrecision]), $MachinePrecision], N[(0.8333333333333334 + N[(N[(t * -0.2222222222222222 + 0.037037037037037035), $MachinePrecision] / N[(t * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{t}{\mathsf{fma}\left(t, 2 + t, 1\right)}\\
\mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 1.9999999999519582:\\
\;\;\;\;\frac{\mathsf{fma}\left(t \cdot 4, t\_1, 1\right)}{\mathsf{fma}\left(t \cdot 4, t\_1, 2\right)}\\

\mathbf{else}:\\
\;\;\;\;0.8333333333333334 + \frac{\mathsf{fma}\left(t, -0.2222222222222222, 0.037037037037037035\right)}{t \cdot t}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (*.f64 #s(literal 2 binary64) t) (+.f64 #s(literal 1 binary64) t)) < 1.99999999995195821

    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. Add Preprocessing
    3. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{\color{blue}{1 + t}} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      2. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{\color{blue}{2 \cdot t}}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      3. frac-2negN/A

        \[\leadsto \frac{1 + \color{blue}{\frac{\mathsf{neg}\left(2 \cdot t\right)}{\mathsf{neg}\left(\left(1 + t\right)\right)}} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      4. lift-+.f64N/A

        \[\leadsto \frac{1 + \frac{\mathsf{neg}\left(2 \cdot t\right)}{\mathsf{neg}\left(\left(1 + t\right)\right)} \cdot \frac{2 \cdot t}{\color{blue}{1 + t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      5. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{\mathsf{neg}\left(2 \cdot t\right)}{\mathsf{neg}\left(\left(1 + t\right)\right)} \cdot \frac{\color{blue}{2 \cdot t}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      6. frac-2negN/A

        \[\leadsto \frac{1 + \color{blue}{\frac{2 \cdot t}{1 + t}} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      7. lift-/.f64N/A

        \[\leadsto \frac{1 + \color{blue}{\frac{2 \cdot t}{1 + t}} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      8. lift-/.f64N/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2 \cdot t}{1 + t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      9. lift-*.f64N/A

        \[\leadsto \frac{1 + \color{blue}{\frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      10. lift-+.f64N/A

        \[\leadsto \frac{\color{blue}{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      11. lift-+.f64N/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{\color{blue}{1 + t}} \cdot \frac{2 \cdot t}{1 + t}} \]
      12. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{\color{blue}{2 \cdot t}}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      13. frac-2negN/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \color{blue}{\frac{\mathsf{neg}\left(2 \cdot t\right)}{\mathsf{neg}\left(\left(1 + t\right)\right)}} \cdot \frac{2 \cdot t}{1 + t}} \]
    4. Applied rewrites100.0%

      \[\leadsto \color{blue}{\frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}} \]
    5. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \color{blue}{\left(t \cdot 4\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}} \]
      2. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{\color{blue}{t \cdot \left(t \cdot 4\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}} \]
      3. lift-+.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\color{blue}{\left(1 + t\right)} \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}} \]
      4. lift-+.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \color{blue}{\left(1 + t\right)}}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}} \]
      5. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\color{blue}{\left(1 + t\right) \cdot \left(1 + t\right)}}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}} \]
      6. lift-/.f64N/A

        \[\leadsto \frac{1 + \color{blue}{\frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}} \]
      7. lift-+.f64N/A

        \[\leadsto \frac{\color{blue}{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}} \]
      8. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \color{blue}{\left(t \cdot 4\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}} \]
      9. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{\color{blue}{t \cdot \left(t \cdot 4\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}} \]
      10. lift-+.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\color{blue}{\left(1 + t\right)} \cdot \left(1 + t\right)}} \]
      11. lift-+.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \color{blue}{\left(1 + t\right)}}} \]
      12. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\color{blue}{\left(1 + t\right) \cdot \left(1 + t\right)}}} \]
      13. lift-/.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \color{blue}{\frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}} \]
      14. lift-+.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{\color{blue}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}} \]
    6. Applied rewrites100.0%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)}} \]
    7. Taylor expanded in t around 0

      \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{1 + t \cdot \left(2 + t\right)}}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
    8. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{t \cdot \left(2 + t\right) + 1}}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      2. metadata-evalN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \left(\color{blue}{2 \cdot 1} + t\right) + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      3. lft-mult-inverseN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \left(2 \cdot \color{blue}{\left(\frac{1}{t} \cdot t\right)} + t\right) + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      4. associate-*l*N/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \left(\color{blue}{\left(2 \cdot \frac{1}{t}\right) \cdot t} + t\right) + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      5. *-commutativeN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \left(\color{blue}{t \cdot \left(2 \cdot \frac{1}{t}\right)} + t\right) + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      6. *-rgt-identityN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \left(t \cdot \left(2 \cdot \frac{1}{t}\right) + \color{blue}{t \cdot 1}\right) + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      7. distribute-lft-inN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \color{blue}{\left(t \cdot \left(2 \cdot \frac{1}{t} + 1\right)\right)} + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      8. +-commutativeN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \left(t \cdot \color{blue}{\left(1 + 2 \cdot \frac{1}{t}\right)}\right) + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      9. associate-*l*N/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{\left(t \cdot t\right) \cdot \left(1 + 2 \cdot \frac{1}{t}\right)} + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      10. unpow2N/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{{t}^{2}} \cdot \left(1 + 2 \cdot \frac{1}{t}\right) + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      11. *-commutativeN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{\left(1 + 2 \cdot \frac{1}{t}\right) \cdot {t}^{2}} + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      12. unpow2N/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + 2 \cdot \frac{1}{t}\right) \cdot \color{blue}{\left(t \cdot t\right)} + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      13. associate-*r*N/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{\left(\left(1 + 2 \cdot \frac{1}{t}\right) \cdot t\right) \cdot t} + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      14. *-commutativeN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{t \cdot \left(\left(1 + 2 \cdot \frac{1}{t}\right) \cdot t\right)} + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      15. lower-fma.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{\mathsf{fma}\left(t, \left(1 + 2 \cdot \frac{1}{t}\right) \cdot t, 1\right)}}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
    9. Applied rewrites100.0%

      \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{\mathsf{fma}\left(t, 2 + t, 1\right)}}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
    10. Taylor expanded in t around 0

      \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\mathsf{fma}\left(t, 2 + t, 1\right)}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{1 + t \cdot \left(2 + t\right)}}, 2\right)} \]
    11. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\mathsf{fma}\left(t, 2 + t, 1\right)}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{t \cdot \left(2 + t\right) + 1}}, 2\right)} \]
      2. metadata-evalN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\mathsf{fma}\left(t, 2 + t, 1\right)}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \left(\color{blue}{2 \cdot 1} + t\right) + 1}, 2\right)} \]
      3. lft-mult-inverseN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\mathsf{fma}\left(t, 2 + t, 1\right)}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \left(2 \cdot \color{blue}{\left(\frac{1}{t} \cdot t\right)} + t\right) + 1}, 2\right)} \]
      4. associate-*l*N/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\mathsf{fma}\left(t, 2 + t, 1\right)}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \left(\color{blue}{\left(2 \cdot \frac{1}{t}\right) \cdot t} + t\right) + 1}, 2\right)} \]
      5. *-commutativeN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\mathsf{fma}\left(t, 2 + t, 1\right)}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \left(\color{blue}{t \cdot \left(2 \cdot \frac{1}{t}\right)} + t\right) + 1}, 2\right)} \]
      6. *-rgt-identityN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\mathsf{fma}\left(t, 2 + t, 1\right)}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \left(t \cdot \left(2 \cdot \frac{1}{t}\right) + \color{blue}{t \cdot 1}\right) + 1}, 2\right)} \]
      7. distribute-lft-inN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\mathsf{fma}\left(t, 2 + t, 1\right)}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \color{blue}{\left(t \cdot \left(2 \cdot \frac{1}{t} + 1\right)\right)} + 1}, 2\right)} \]
      8. +-commutativeN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\mathsf{fma}\left(t, 2 + t, 1\right)}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \left(t \cdot \color{blue}{\left(1 + 2 \cdot \frac{1}{t}\right)}\right) + 1}, 2\right)} \]
      9. associate-*l*N/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\mathsf{fma}\left(t, 2 + t, 1\right)}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{\left(t \cdot t\right) \cdot \left(1 + 2 \cdot \frac{1}{t}\right)} + 1}, 2\right)} \]
      10. unpow2N/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\mathsf{fma}\left(t, 2 + t, 1\right)}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{{t}^{2}} \cdot \left(1 + 2 \cdot \frac{1}{t}\right) + 1}, 2\right)} \]
      11. *-commutativeN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\mathsf{fma}\left(t, 2 + t, 1\right)}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{\left(1 + 2 \cdot \frac{1}{t}\right) \cdot {t}^{2}} + 1}, 2\right)} \]
      12. unpow2N/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\mathsf{fma}\left(t, 2 + t, 1\right)}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + 2 \cdot \frac{1}{t}\right) \cdot \color{blue}{\left(t \cdot t\right)} + 1}, 2\right)} \]
      13. associate-*r*N/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\mathsf{fma}\left(t, 2 + t, 1\right)}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{\left(\left(1 + 2 \cdot \frac{1}{t}\right) \cdot t\right) \cdot t} + 1}, 2\right)} \]
      14. *-commutativeN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\mathsf{fma}\left(t, 2 + t, 1\right)}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{t \cdot \left(\left(1 + 2 \cdot \frac{1}{t}\right) \cdot t\right)} + 1}, 2\right)} \]
      15. lower-fma.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\mathsf{fma}\left(t, 2 + t, 1\right)}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{\mathsf{fma}\left(t, \left(1 + 2 \cdot \frac{1}{t}\right) \cdot t, 1\right)}}, 2\right)} \]
    12. Applied rewrites100.0%

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

    if 1.99999999995195821 < (/.f64 (*.f64 #s(literal 2 binary64) t) (+.f64 #s(literal 1 binary64) t))

    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. Add Preprocessing
    3. Taylor expanded in t around inf

      \[\leadsto \color{blue}{\left(\frac{5}{6} + \frac{\frac{1}{27}}{{t}^{2}}\right) - \frac{2}{9} \cdot \frac{1}{t}} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \color{blue}{\left(\frac{\frac{1}{27}}{{t}^{2}} + \frac{5}{6}\right)} - \frac{2}{9} \cdot \frac{1}{t} \]
      2. associate--l+N/A

        \[\leadsto \color{blue}{\frac{\frac{1}{27}}{{t}^{2}} + \left(\frac{5}{6} - \frac{2}{9} \cdot \frac{1}{t}\right)} \]
      3. +-commutativeN/A

        \[\leadsto \color{blue}{\left(\frac{5}{6} - \frac{2}{9} \cdot \frac{1}{t}\right) + \frac{\frac{1}{27}}{{t}^{2}}} \]
      4. associate--r-N/A

        \[\leadsto \color{blue}{\frac{5}{6} - \left(\frac{2}{9} \cdot \frac{1}{t} - \frac{\frac{1}{27}}{{t}^{2}}\right)} \]
      5. associate-*r/N/A

        \[\leadsto \frac{5}{6} - \left(\color{blue}{\frac{\frac{2}{9} \cdot 1}{t}} - \frac{\frac{1}{27}}{{t}^{2}}\right) \]
      6. metadata-evalN/A

        \[\leadsto \frac{5}{6} - \left(\frac{\color{blue}{\frac{2}{9}}}{t} - \frac{\frac{1}{27}}{{t}^{2}}\right) \]
      7. unpow2N/A

        \[\leadsto \frac{5}{6} - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27}}{\color{blue}{t \cdot t}}\right) \]
      8. associate-/r*N/A

        \[\leadsto \frac{5}{6} - \left(\frac{\frac{2}{9}}{t} - \color{blue}{\frac{\frac{\frac{1}{27}}{t}}{t}}\right) \]
      9. metadata-evalN/A

        \[\leadsto \frac{5}{6} - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{\color{blue}{\frac{1}{27} \cdot 1}}{t}}{t}\right) \]
      10. associate-*r/N/A

        \[\leadsto \frac{5}{6} - \left(\frac{\frac{2}{9}}{t} - \frac{\color{blue}{\frac{1}{27} \cdot \frac{1}{t}}}{t}\right) \]
      11. div-subN/A

        \[\leadsto \frac{5}{6} - \color{blue}{\frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{t}} \]
      12. unsub-negN/A

        \[\leadsto \color{blue}{\frac{5}{6} + \left(\mathsf{neg}\left(\frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{t}\right)\right)} \]
      13. mul-1-negN/A

        \[\leadsto \frac{5}{6} + \color{blue}{-1 \cdot \frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{t}} \]
      14. lower-+.f64N/A

        \[\leadsto \color{blue}{\frac{5}{6} + -1 \cdot \frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{t}} \]
      15. associate-*r/N/A

        \[\leadsto \frac{5}{6} + \color{blue}{\frac{-1 \cdot \left(\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}\right)}{t}} \]
    5. Applied rewrites100.0%

      \[\leadsto \color{blue}{0.8333333333333334 + \frac{\frac{0.037037037037037035}{t} + -0.2222222222222222}{t}} \]
    6. Taylor expanded in t around 0

      \[\leadsto \frac{5}{6} + \color{blue}{\frac{\frac{1}{27} + \frac{-2}{9} \cdot t}{{t}^{2}}} \]
    7. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \frac{5}{6} + \color{blue}{\frac{\frac{1}{27} + \frac{-2}{9} \cdot t}{{t}^{2}}} \]
      2. +-commutativeN/A

        \[\leadsto \frac{5}{6} + \frac{\color{blue}{\frac{-2}{9} \cdot t + \frac{1}{27}}}{{t}^{2}} \]
      3. *-commutativeN/A

        \[\leadsto \frac{5}{6} + \frac{\color{blue}{t \cdot \frac{-2}{9}} + \frac{1}{27}}{{t}^{2}} \]
      4. lower-fma.f64N/A

        \[\leadsto \frac{5}{6} + \frac{\color{blue}{\mathsf{fma}\left(t, \frac{-2}{9}, \frac{1}{27}\right)}}{{t}^{2}} \]
      5. unpow2N/A

        \[\leadsto \frac{5}{6} + \frac{\mathsf{fma}\left(t, \frac{-2}{9}, \frac{1}{27}\right)}{\color{blue}{t \cdot t}} \]
      6. lower-*.f64100.0

        \[\leadsto 0.8333333333333334 + \frac{\mathsf{fma}\left(t, -0.2222222222222222, 0.037037037037037035\right)}{\color{blue}{t \cdot t}} \]
    8. Applied rewrites100.0%

      \[\leadsto 0.8333333333333334 + \color{blue}{\frac{\mathsf{fma}\left(t, -0.2222222222222222, 0.037037037037037035\right)}{t \cdot t}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification100.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 1.9999999999519582:\\ \;\;\;\;\frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\mathsf{fma}\left(t, 2 + t, 1\right)}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\mathsf{fma}\left(t, 2 + t, 1\right)}, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 + \frac{\mathsf{fma}\left(t, -0.2222222222222222, 0.037037037037037035\right)}{t \cdot t}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 99.1% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 10^{-5}:\\ \;\;\;\;\mathsf{fma}\left(t, t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{0.04938271604938271}{t \cdot \left(t \cdot t\right)} + \left(\frac{\mathsf{fma}\left(t, -0.2222222222222222, 0.037037037037037035\right)}{t \cdot t} - -0.8333333333333334\right)\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (<= (/ (* 2.0 t) (+ t 1.0)) 1e-5)
   (fma t t 0.5)
   (+
    (/ 0.04938271604938271 (* t (* t t)))
    (-
     (/ (fma t -0.2222222222222222 0.037037037037037035) (* t t))
     -0.8333333333333334))))
double code(double t) {
	double tmp;
	if (((2.0 * t) / (t + 1.0)) <= 1e-5) {
		tmp = fma(t, t, 0.5);
	} else {
		tmp = (0.04938271604938271 / (t * (t * t))) + ((fma(t, -0.2222222222222222, 0.037037037037037035) / (t * t)) - -0.8333333333333334);
	}
	return tmp;
}
function code(t)
	tmp = 0.0
	if (Float64(Float64(2.0 * t) / Float64(t + 1.0)) <= 1e-5)
		tmp = fma(t, t, 0.5);
	else
		tmp = Float64(Float64(0.04938271604938271 / Float64(t * Float64(t * t))) + Float64(Float64(fma(t, -0.2222222222222222, 0.037037037037037035) / Float64(t * t)) - -0.8333333333333334));
	end
	return tmp
end
code[t_] := If[LessEqual[N[(N[(2.0 * t), $MachinePrecision] / N[(t + 1.0), $MachinePrecision]), $MachinePrecision], 1e-5], N[(t * t + 0.5), $MachinePrecision], N[(N[(0.04938271604938271 / N[(t * N[(t * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(t * -0.2222222222222222 + 0.037037037037037035), $MachinePrecision] / N[(t * t), $MachinePrecision]), $MachinePrecision] - -0.8333333333333334), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 10^{-5}:\\
\;\;\;\;\mathsf{fma}\left(t, t, 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{0.04938271604938271}{t \cdot \left(t \cdot t\right)} + \left(\frac{\mathsf{fma}\left(t, -0.2222222222222222, 0.037037037037037035\right)}{t \cdot t} - -0.8333333333333334\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (*.f64 #s(literal 2 binary64) t) (+.f64 #s(literal 1 binary64) t)) < 1.00000000000000008e-5

    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. Add Preprocessing
    3. Taylor expanded in t around 0

      \[\leadsto \color{blue}{\frac{1}{2} + {t}^{2}} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \color{blue}{{t}^{2} + \frac{1}{2}} \]
      2. unpow2N/A

        \[\leadsto \color{blue}{t \cdot t} + \frac{1}{2} \]
      3. lower-fma.f64100.0

        \[\leadsto \color{blue}{\mathsf{fma}\left(t, t, 0.5\right)} \]
    5. Applied rewrites100.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(t, t, 0.5\right)} \]

    if 1.00000000000000008e-5 < (/.f64 (*.f64 #s(literal 2 binary64) t) (+.f64 #s(literal 1 binary64) t))

    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. Add Preprocessing
    3. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{\color{blue}{1 + t}} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      2. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{\color{blue}{2 \cdot t}}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      3. frac-2negN/A

        \[\leadsto \frac{1 + \color{blue}{\frac{\mathsf{neg}\left(2 \cdot t\right)}{\mathsf{neg}\left(\left(1 + t\right)\right)}} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      4. lift-+.f64N/A

        \[\leadsto \frac{1 + \frac{\mathsf{neg}\left(2 \cdot t\right)}{\mathsf{neg}\left(\left(1 + t\right)\right)} \cdot \frac{2 \cdot t}{\color{blue}{1 + t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      5. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{\mathsf{neg}\left(2 \cdot t\right)}{\mathsf{neg}\left(\left(1 + t\right)\right)} \cdot \frac{\color{blue}{2 \cdot t}}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      6. frac-2negN/A

        \[\leadsto \frac{1 + \color{blue}{\frac{2 \cdot t}{1 + t}} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      7. lift-/.f64N/A

        \[\leadsto \frac{1 + \color{blue}{\frac{2 \cdot t}{1 + t}} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      8. lift-/.f64N/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \color{blue}{\frac{2 \cdot t}{1 + t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      9. lift-*.f64N/A

        \[\leadsto \frac{1 + \color{blue}{\frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      10. lift-+.f64N/A

        \[\leadsto \frac{\color{blue}{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      11. lift-+.f64N/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{2 \cdot t}{\color{blue}{1 + t}} \cdot \frac{2 \cdot t}{1 + t}} \]
      12. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \frac{\color{blue}{2 \cdot t}}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      13. frac-2negN/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \color{blue}{\frac{\mathsf{neg}\left(2 \cdot t\right)}{\mathsf{neg}\left(\left(1 + t\right)\right)}} \cdot \frac{2 \cdot t}{1 + t}} \]
    4. Applied rewrites50.3%

      \[\leadsto \color{blue}{\frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}} \]
    5. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \color{blue}{\left(t \cdot 4\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}} \]
      2. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{\color{blue}{t \cdot \left(t \cdot 4\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}} \]
      3. lift-+.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\color{blue}{\left(1 + t\right)} \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}} \]
      4. lift-+.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \color{blue}{\left(1 + t\right)}}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}} \]
      5. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\color{blue}{\left(1 + t\right) \cdot \left(1 + t\right)}}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}} \]
      6. lift-/.f64N/A

        \[\leadsto \frac{1 + \color{blue}{\frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}} \]
      7. lift-+.f64N/A

        \[\leadsto \frac{\color{blue}{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}} \]
      8. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \color{blue}{\left(t \cdot 4\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}} \]
      9. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{\color{blue}{t \cdot \left(t \cdot 4\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)}} \]
      10. lift-+.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\color{blue}{\left(1 + t\right)} \cdot \left(1 + t\right)}} \]
      11. lift-+.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \color{blue}{\left(1 + t\right)}}} \]
      12. lift-*.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\color{blue}{\left(1 + t\right) \cdot \left(1 + t\right)}}} \]
      13. lift-/.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{2 + \color{blue}{\frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}} \]
      14. lift-+.f64N/A

        \[\leadsto \frac{1 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}{\color{blue}{2 + \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}}} \]
    6. Applied rewrites60.0%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)}} \]
    7. Taylor expanded in t around 0

      \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{1 + t \cdot \left(2 + t\right)}}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
    8. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{t \cdot \left(2 + t\right) + 1}}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      2. metadata-evalN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \left(\color{blue}{2 \cdot 1} + t\right) + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      3. lft-mult-inverseN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \left(2 \cdot \color{blue}{\left(\frac{1}{t} \cdot t\right)} + t\right) + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      4. associate-*l*N/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \left(\color{blue}{\left(2 \cdot \frac{1}{t}\right) \cdot t} + t\right) + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      5. *-commutativeN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \left(\color{blue}{t \cdot \left(2 \cdot \frac{1}{t}\right)} + t\right) + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      6. *-rgt-identityN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \left(t \cdot \left(2 \cdot \frac{1}{t}\right) + \color{blue}{t \cdot 1}\right) + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      7. distribute-lft-inN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \color{blue}{\left(t \cdot \left(2 \cdot \frac{1}{t} + 1\right)\right)} + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      8. +-commutativeN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{t \cdot \left(t \cdot \color{blue}{\left(1 + 2 \cdot \frac{1}{t}\right)}\right) + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      9. associate-*l*N/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{\left(t \cdot t\right) \cdot \left(1 + 2 \cdot \frac{1}{t}\right)} + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      10. unpow2N/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{{t}^{2}} \cdot \left(1 + 2 \cdot \frac{1}{t}\right) + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      11. *-commutativeN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{\left(1 + 2 \cdot \frac{1}{t}\right) \cdot {t}^{2}} + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      12. unpow2N/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + 2 \cdot \frac{1}{t}\right) \cdot \color{blue}{\left(t \cdot t\right)} + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      13. associate-*r*N/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{\left(\left(1 + 2 \cdot \frac{1}{t}\right) \cdot t\right) \cdot t} + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      14. *-commutativeN/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{t \cdot \left(\left(1 + 2 \cdot \frac{1}{t}\right) \cdot t\right)} + 1}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
      15. lower-fma.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{\mathsf{fma}\left(t, \left(1 + 2 \cdot \frac{1}{t}\right) \cdot t, 1\right)}}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
    9. Applied rewrites60.0%

      \[\leadsto \frac{\mathsf{fma}\left(t \cdot 4, \frac{t}{\color{blue}{\mathsf{fma}\left(t, 2 + t, 1\right)}}, 1\right)}{\mathsf{fma}\left(t \cdot 4, \frac{t}{\left(1 + t\right) \cdot \left(1 + t\right)}, 2\right)} \]
    10. Taylor expanded in t around inf

      \[\leadsto \color{blue}{\left(\frac{5}{6} + \left(\frac{\frac{1}{27}}{{t}^{2}} + \frac{4}{81} \cdot \frac{1}{{t}^{3}}\right)\right) - \frac{2}{9} \cdot \frac{1}{t}} \]
    11. Applied rewrites99.6%

      \[\leadsto \color{blue}{\frac{0.04938271604938271}{t \cdot \left(t \cdot t\right)} - \left(-0.8333333333333334 - \frac{\mathsf{fma}\left(t, -0.2222222222222222, 0.037037037037037035\right)}{t \cdot t}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 10^{-5}:\\ \;\;\;\;\mathsf{fma}\left(t, t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{0.04938271604938271}{t \cdot \left(t \cdot t\right)} + \left(\frac{\mathsf{fma}\left(t, -0.2222222222222222, 0.037037037037037035\right)}{t \cdot t} - -0.8333333333333334\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 99.1% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 10^{-5}:\\ \;\;\;\;\mathsf{fma}\left(t, t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 + \frac{-0.2222222222222222 + \frac{\frac{0.04938271604938271}{t} - -0.037037037037037035}{t}}{t}\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (<= (/ (* 2.0 t) (+ t 1.0)) 1e-5)
   (fma t t 0.5)
   (+
    0.8333333333333334
    (/
     (+
      -0.2222222222222222
      (/ (- (/ 0.04938271604938271 t) -0.037037037037037035) t))
     t))))
double code(double t) {
	double tmp;
	if (((2.0 * t) / (t + 1.0)) <= 1e-5) {
		tmp = fma(t, t, 0.5);
	} else {
		tmp = 0.8333333333333334 + ((-0.2222222222222222 + (((0.04938271604938271 / t) - -0.037037037037037035) / t)) / t);
	}
	return tmp;
}
function code(t)
	tmp = 0.0
	if (Float64(Float64(2.0 * t) / Float64(t + 1.0)) <= 1e-5)
		tmp = fma(t, t, 0.5);
	else
		tmp = Float64(0.8333333333333334 + Float64(Float64(-0.2222222222222222 + Float64(Float64(Float64(0.04938271604938271 / t) - -0.037037037037037035) / t)) / t));
	end
	return tmp
end
code[t_] := If[LessEqual[N[(N[(2.0 * t), $MachinePrecision] / N[(t + 1.0), $MachinePrecision]), $MachinePrecision], 1e-5], N[(t * t + 0.5), $MachinePrecision], N[(0.8333333333333334 + N[(N[(-0.2222222222222222 + N[(N[(N[(0.04938271604938271 / t), $MachinePrecision] - -0.037037037037037035), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 10^{-5}:\\
\;\;\;\;\mathsf{fma}\left(t, t, 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;0.8333333333333334 + \frac{-0.2222222222222222 + \frac{\frac{0.04938271604938271}{t} - -0.037037037037037035}{t}}{t}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (*.f64 #s(literal 2 binary64) t) (+.f64 #s(literal 1 binary64) t)) < 1.00000000000000008e-5

    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. Add Preprocessing
    3. Taylor expanded in t around 0

      \[\leadsto \color{blue}{\frac{1}{2} + {t}^{2}} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \color{blue}{{t}^{2} + \frac{1}{2}} \]
      2. unpow2N/A

        \[\leadsto \color{blue}{t \cdot t} + \frac{1}{2} \]
      3. lower-fma.f64100.0

        \[\leadsto \color{blue}{\mathsf{fma}\left(t, t, 0.5\right)} \]
    5. Applied rewrites100.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(t, t, 0.5\right)} \]

    if 1.00000000000000008e-5 < (/.f64 (*.f64 #s(literal 2 binary64) t) (+.f64 #s(literal 1 binary64) t))

    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. Add Preprocessing
    3. Taylor expanded in t around inf

      \[\leadsto \color{blue}{\left(\frac{5}{6} + \left(\frac{\frac{1}{27}}{{t}^{2}} + \frac{4}{81} \cdot \frac{1}{{t}^{3}}\right)\right) - \frac{2}{9} \cdot \frac{1}{t}} \]
    4. Applied rewrites99.6%

      \[\leadsto \color{blue}{0.8333333333333334 + \frac{-0.2222222222222222 - \frac{-0.037037037037037035 - \frac{0.04938271604938271}{t}}{t}}{t}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 10^{-5}:\\ \;\;\;\;\mathsf{fma}\left(t, t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 + \frac{-0.2222222222222222 + \frac{\frac{0.04938271604938271}{t} - -0.037037037037037035}{t}}{t}\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 99.1% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 10^{-5}:\\ \;\;\;\;\mathsf{fma}\left(t, t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 + \frac{\mathsf{fma}\left(t, -0.2222222222222222, 0.037037037037037035\right)}{t \cdot t}\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (<= (/ (* 2.0 t) (+ t 1.0)) 1e-5)
   (fma t t 0.5)
   (+
    0.8333333333333334
    (/ (fma t -0.2222222222222222 0.037037037037037035) (* t t)))))
double code(double t) {
	double tmp;
	if (((2.0 * t) / (t + 1.0)) <= 1e-5) {
		tmp = fma(t, t, 0.5);
	} else {
		tmp = 0.8333333333333334 + (fma(t, -0.2222222222222222, 0.037037037037037035) / (t * t));
	}
	return tmp;
}
function code(t)
	tmp = 0.0
	if (Float64(Float64(2.0 * t) / Float64(t + 1.0)) <= 1e-5)
		tmp = fma(t, t, 0.5);
	else
		tmp = Float64(0.8333333333333334 + Float64(fma(t, -0.2222222222222222, 0.037037037037037035) / Float64(t * t)));
	end
	return tmp
end
code[t_] := If[LessEqual[N[(N[(2.0 * t), $MachinePrecision] / N[(t + 1.0), $MachinePrecision]), $MachinePrecision], 1e-5], N[(t * t + 0.5), $MachinePrecision], N[(0.8333333333333334 + N[(N[(t * -0.2222222222222222 + 0.037037037037037035), $MachinePrecision] / N[(t * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 10^{-5}:\\
\;\;\;\;\mathsf{fma}\left(t, t, 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;0.8333333333333334 + \frac{\mathsf{fma}\left(t, -0.2222222222222222, 0.037037037037037035\right)}{t \cdot t}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (*.f64 #s(literal 2 binary64) t) (+.f64 #s(literal 1 binary64) t)) < 1.00000000000000008e-5

    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. Add Preprocessing
    3. Taylor expanded in t around 0

      \[\leadsto \color{blue}{\frac{1}{2} + {t}^{2}} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \color{blue}{{t}^{2} + \frac{1}{2}} \]
      2. unpow2N/A

        \[\leadsto \color{blue}{t \cdot t} + \frac{1}{2} \]
      3. lower-fma.f64100.0

        \[\leadsto \color{blue}{\mathsf{fma}\left(t, t, 0.5\right)} \]
    5. Applied rewrites100.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(t, t, 0.5\right)} \]

    if 1.00000000000000008e-5 < (/.f64 (*.f64 #s(literal 2 binary64) t) (+.f64 #s(literal 1 binary64) t))

    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. Add Preprocessing
    3. Taylor expanded in t around inf

      \[\leadsto \color{blue}{\left(\frac{5}{6} + \frac{\frac{1}{27}}{{t}^{2}}\right) - \frac{2}{9} \cdot \frac{1}{t}} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \color{blue}{\left(\frac{\frac{1}{27}}{{t}^{2}} + \frac{5}{6}\right)} - \frac{2}{9} \cdot \frac{1}{t} \]
      2. associate--l+N/A

        \[\leadsto \color{blue}{\frac{\frac{1}{27}}{{t}^{2}} + \left(\frac{5}{6} - \frac{2}{9} \cdot \frac{1}{t}\right)} \]
      3. +-commutativeN/A

        \[\leadsto \color{blue}{\left(\frac{5}{6} - \frac{2}{9} \cdot \frac{1}{t}\right) + \frac{\frac{1}{27}}{{t}^{2}}} \]
      4. associate--r-N/A

        \[\leadsto \color{blue}{\frac{5}{6} - \left(\frac{2}{9} \cdot \frac{1}{t} - \frac{\frac{1}{27}}{{t}^{2}}\right)} \]
      5. associate-*r/N/A

        \[\leadsto \frac{5}{6} - \left(\color{blue}{\frac{\frac{2}{9} \cdot 1}{t}} - \frac{\frac{1}{27}}{{t}^{2}}\right) \]
      6. metadata-evalN/A

        \[\leadsto \frac{5}{6} - \left(\frac{\color{blue}{\frac{2}{9}}}{t} - \frac{\frac{1}{27}}{{t}^{2}}\right) \]
      7. unpow2N/A

        \[\leadsto \frac{5}{6} - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{1}{27}}{\color{blue}{t \cdot t}}\right) \]
      8. associate-/r*N/A

        \[\leadsto \frac{5}{6} - \left(\frac{\frac{2}{9}}{t} - \color{blue}{\frac{\frac{\frac{1}{27}}{t}}{t}}\right) \]
      9. metadata-evalN/A

        \[\leadsto \frac{5}{6} - \left(\frac{\frac{2}{9}}{t} - \frac{\frac{\color{blue}{\frac{1}{27} \cdot 1}}{t}}{t}\right) \]
      10. associate-*r/N/A

        \[\leadsto \frac{5}{6} - \left(\frac{\frac{2}{9}}{t} - \frac{\color{blue}{\frac{1}{27} \cdot \frac{1}{t}}}{t}\right) \]
      11. div-subN/A

        \[\leadsto \frac{5}{6} - \color{blue}{\frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{t}} \]
      12. unsub-negN/A

        \[\leadsto \color{blue}{\frac{5}{6} + \left(\mathsf{neg}\left(\frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{t}\right)\right)} \]
      13. mul-1-negN/A

        \[\leadsto \frac{5}{6} + \color{blue}{-1 \cdot \frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{t}} \]
      14. lower-+.f64N/A

        \[\leadsto \color{blue}{\frac{5}{6} + -1 \cdot \frac{\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}}{t}} \]
      15. associate-*r/N/A

        \[\leadsto \frac{5}{6} + \color{blue}{\frac{-1 \cdot \left(\frac{2}{9} - \frac{1}{27} \cdot \frac{1}{t}\right)}{t}} \]
    5. Applied rewrites99.6%

      \[\leadsto \color{blue}{0.8333333333333334 + \frac{\frac{0.037037037037037035}{t} + -0.2222222222222222}{t}} \]
    6. Taylor expanded in t around 0

      \[\leadsto \frac{5}{6} + \color{blue}{\frac{\frac{1}{27} + \frac{-2}{9} \cdot t}{{t}^{2}}} \]
    7. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \frac{5}{6} + \color{blue}{\frac{\frac{1}{27} + \frac{-2}{9} \cdot t}{{t}^{2}}} \]
      2. +-commutativeN/A

        \[\leadsto \frac{5}{6} + \frac{\color{blue}{\frac{-2}{9} \cdot t + \frac{1}{27}}}{{t}^{2}} \]
      3. *-commutativeN/A

        \[\leadsto \frac{5}{6} + \frac{\color{blue}{t \cdot \frac{-2}{9}} + \frac{1}{27}}{{t}^{2}} \]
      4. lower-fma.f64N/A

        \[\leadsto \frac{5}{6} + \frac{\color{blue}{\mathsf{fma}\left(t, \frac{-2}{9}, \frac{1}{27}\right)}}{{t}^{2}} \]
      5. unpow2N/A

        \[\leadsto \frac{5}{6} + \frac{\mathsf{fma}\left(t, \frac{-2}{9}, \frac{1}{27}\right)}{\color{blue}{t \cdot t}} \]
      6. lower-*.f6499.6

        \[\leadsto 0.8333333333333334 + \frac{\mathsf{fma}\left(t, -0.2222222222222222, 0.037037037037037035\right)}{\color{blue}{t \cdot t}} \]
    8. Applied rewrites99.6%

      \[\leadsto 0.8333333333333334 + \color{blue}{\frac{\mathsf{fma}\left(t, -0.2222222222222222, 0.037037037037037035\right)}{t \cdot t}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 10^{-5}:\\ \;\;\;\;\mathsf{fma}\left(t, t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 + \frac{\mathsf{fma}\left(t, -0.2222222222222222, 0.037037037037037035\right)}{t \cdot t}\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 98.9% accurate, 2.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 10^{-5}:\\ \;\;\;\;\mathsf{fma}\left(t, t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 + \frac{-0.2222222222222222}{t}\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (<= (/ (* 2.0 t) (+ t 1.0)) 1e-5)
   (fma t t 0.5)
   (+ 0.8333333333333334 (/ -0.2222222222222222 t))))
double code(double t) {
	double tmp;
	if (((2.0 * t) / (t + 1.0)) <= 1e-5) {
		tmp = fma(t, t, 0.5);
	} else {
		tmp = 0.8333333333333334 + (-0.2222222222222222 / t);
	}
	return tmp;
}
function code(t)
	tmp = 0.0
	if (Float64(Float64(2.0 * t) / Float64(t + 1.0)) <= 1e-5)
		tmp = fma(t, t, 0.5);
	else
		tmp = Float64(0.8333333333333334 + Float64(-0.2222222222222222 / t));
	end
	return tmp
end
code[t_] := If[LessEqual[N[(N[(2.0 * t), $MachinePrecision] / N[(t + 1.0), $MachinePrecision]), $MachinePrecision], 1e-5], N[(t * t + 0.5), $MachinePrecision], N[(0.8333333333333334 + N[(-0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 10^{-5}:\\
\;\;\;\;\mathsf{fma}\left(t, t, 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;0.8333333333333334 + \frac{-0.2222222222222222}{t}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (*.f64 #s(literal 2 binary64) t) (+.f64 #s(literal 1 binary64) t)) < 1.00000000000000008e-5

    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. Add Preprocessing
    3. Taylor expanded in t around 0

      \[\leadsto \color{blue}{\frac{1}{2} + {t}^{2}} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \color{blue}{{t}^{2} + \frac{1}{2}} \]
      2. unpow2N/A

        \[\leadsto \color{blue}{t \cdot t} + \frac{1}{2} \]
      3. lower-fma.f64100.0

        \[\leadsto \color{blue}{\mathsf{fma}\left(t, t, 0.5\right)} \]
    5. Applied rewrites100.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(t, t, 0.5\right)} \]

    if 1.00000000000000008e-5 < (/.f64 (*.f64 #s(literal 2 binary64) t) (+.f64 #s(literal 1 binary64) t))

    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. Add Preprocessing
    3. Taylor expanded in t around inf

      \[\leadsto \color{blue}{\frac{5}{6} - \frac{2}{9} \cdot \frac{1}{t}} \]
    4. Step-by-step derivation
      1. sub-negN/A

        \[\leadsto \color{blue}{\frac{5}{6} + \left(\mathsf{neg}\left(\frac{2}{9} \cdot \frac{1}{t}\right)\right)} \]
      2. lower-+.f64N/A

        \[\leadsto \color{blue}{\frac{5}{6} + \left(\mathsf{neg}\left(\frac{2}{9} \cdot \frac{1}{t}\right)\right)} \]
      3. associate-*r/N/A

        \[\leadsto \frac{5}{6} + \left(\mathsf{neg}\left(\color{blue}{\frac{\frac{2}{9} \cdot 1}{t}}\right)\right) \]
      4. metadata-evalN/A

        \[\leadsto \frac{5}{6} + \left(\mathsf{neg}\left(\frac{\color{blue}{\frac{2}{9}}}{t}\right)\right) \]
      5. distribute-neg-fracN/A

        \[\leadsto \frac{5}{6} + \color{blue}{\frac{\mathsf{neg}\left(\frac{2}{9}\right)}{t}} \]
      6. lower-/.f64N/A

        \[\leadsto \frac{5}{6} + \color{blue}{\frac{\mathsf{neg}\left(\frac{2}{9}\right)}{t}} \]
      7. metadata-eval99.3

        \[\leadsto 0.8333333333333334 + \frac{\color{blue}{-0.2222222222222222}}{t} \]
    5. Applied rewrites99.3%

      \[\leadsto \color{blue}{0.8333333333333334 + \frac{-0.2222222222222222}{t}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 10^{-5}:\\ \;\;\;\;\mathsf{fma}\left(t, t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 + \frac{-0.2222222222222222}{t}\\ \end{array} \]
  5. Add Preprocessing

Alternative 8: 98.5% accurate, 3.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 10^{-5}:\\ \;\;\;\;\mathsf{fma}\left(t, t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (<= (/ (* 2.0 t) (+ t 1.0)) 1e-5) (fma t t 0.5) 0.8333333333333334))
double code(double t) {
	double tmp;
	if (((2.0 * t) / (t + 1.0)) <= 1e-5) {
		tmp = fma(t, t, 0.5);
	} else {
		tmp = 0.8333333333333334;
	}
	return tmp;
}
function code(t)
	tmp = 0.0
	if (Float64(Float64(2.0 * t) / Float64(t + 1.0)) <= 1e-5)
		tmp = fma(t, t, 0.5);
	else
		tmp = 0.8333333333333334;
	end
	return tmp
end
code[t_] := If[LessEqual[N[(N[(2.0 * t), $MachinePrecision] / N[(t + 1.0), $MachinePrecision]), $MachinePrecision], 1e-5], N[(t * t + 0.5), $MachinePrecision], 0.8333333333333334]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 10^{-5}:\\
\;\;\;\;\mathsf{fma}\left(t, t, 0.5\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (*.f64 #s(literal 2 binary64) t) (+.f64 #s(literal 1 binary64) t)) < 1.00000000000000008e-5

    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. Add Preprocessing
    3. Taylor expanded in t around 0

      \[\leadsto \color{blue}{\frac{1}{2} + {t}^{2}} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \color{blue}{{t}^{2} + \frac{1}{2}} \]
      2. unpow2N/A

        \[\leadsto \color{blue}{t \cdot t} + \frac{1}{2} \]
      3. lower-fma.f64100.0

        \[\leadsto \color{blue}{\mathsf{fma}\left(t, t, 0.5\right)} \]
    5. Applied rewrites100.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(t, t, 0.5\right)} \]

    if 1.00000000000000008e-5 < (/.f64 (*.f64 #s(literal 2 binary64) t) (+.f64 #s(literal 1 binary64) t))

    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. Add Preprocessing
    3. Taylor expanded in t around inf

      \[\leadsto \color{blue}{\frac{5}{6}} \]
    4. Step-by-step derivation
      1. Applied rewrites97.6%

        \[\leadsto \color{blue}{0.8333333333333334} \]
    5. Recombined 2 regimes into one program.
    6. Final simplification98.7%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 10^{-5}:\\ \;\;\;\;\mathsf{fma}\left(t, t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334\\ \end{array} \]
    7. Add Preprocessing

    Alternative 9: 98.5% accurate, 4.0× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 1:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334\\ \end{array} \end{array} \]
    (FPCore (t)
     :precision binary64
     (if (<= (/ (* 2.0 t) (+ t 1.0)) 1.0) 0.5 0.8333333333333334))
    double code(double t) {
    	double tmp;
    	if (((2.0 * t) / (t + 1.0)) <= 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 (((2.0d0 * t) / (t + 1.0d0)) <= 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 (((2.0 * t) / (t + 1.0)) <= 1.0) {
    		tmp = 0.5;
    	} else {
    		tmp = 0.8333333333333334;
    	}
    	return tmp;
    }
    
    def code(t):
    	tmp = 0
    	if ((2.0 * t) / (t + 1.0)) <= 1.0:
    		tmp = 0.5
    	else:
    		tmp = 0.8333333333333334
    	return tmp
    
    function code(t)
    	tmp = 0.0
    	if (Float64(Float64(2.0 * t) / Float64(t + 1.0)) <= 1.0)
    		tmp = 0.5;
    	else
    		tmp = 0.8333333333333334;
    	end
    	return tmp
    end
    
    function tmp_2 = code(t)
    	tmp = 0.0;
    	if (((2.0 * t) / (t + 1.0)) <= 1.0)
    		tmp = 0.5;
    	else
    		tmp = 0.8333333333333334;
    	end
    	tmp_2 = tmp;
    end
    
    code[t_] := If[LessEqual[N[(N[(2.0 * t), $MachinePrecision] / N[(t + 1.0), $MachinePrecision]), $MachinePrecision], 1.0], 0.5, 0.8333333333333334]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 1:\\
    \;\;\;\;0.5\\
    
    \mathbf{else}:\\
    \;\;\;\;0.8333333333333334\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (/.f64 (*.f64 #s(literal 2 binary64) t) (+.f64 #s(literal 1 binary64) t)) < 1

      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. Add Preprocessing
      3. Taylor expanded in t around 0

        \[\leadsto \color{blue}{\frac{1}{2}} \]
      4. Step-by-step derivation
        1. Applied rewrites99.8%

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

        if 1 < (/.f64 (*.f64 #s(literal 2 binary64) t) (+.f64 #s(literal 1 binary64) t))

        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. Add Preprocessing
        3. Taylor expanded in t around inf

          \[\leadsto \color{blue}{\frac{5}{6}} \]
        4. Step-by-step derivation
          1. Applied rewrites97.6%

            \[\leadsto \color{blue}{0.8333333333333334} \]
        5. Recombined 2 regimes into one program.
        6. Final simplification98.6%

          \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{2 \cdot t}{t + 1} \leq 1:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334\\ \end{array} \]
        7. Add Preprocessing

        Alternative 10: 59.6% accurate, 104.0× 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 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. Add Preprocessing
        3. Taylor expanded in t around 0

          \[\leadsto \color{blue}{\frac{1}{2}} \]
        4. Step-by-step derivation
          1. Applied rewrites56.3%

            \[\leadsto \color{blue}{0.5} \]
          2. Add Preprocessing

          Reproduce

          ?
          herbie shell --seed 2024219 
          (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))))))