Kahan p13 Example 1

Percentage Accurate: 99.9% → 99.9%
Time: 8.7s
Alternatives: 11
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 11 alternatives:

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

Initial Program: 99.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{2 \cdot t}{1 + t}\\ t_2 := t\_1 \cdot t\_1\\ \frac{1 + t\_2}{2 + t\_2} \end{array} \end{array} \]
(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: 99.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{t \cdot 2}{-1 - t} \cdot \frac{t \cdot 2}{t - -1}\\ \frac{1 - t\_1}{2 - t\_1} \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (* (/ (* t 2.0) (- -1.0 t)) (/ (* t 2.0) (- t -1.0)))))
   (/ (- 1.0 t_1) (- 2.0 t_1))))
double code(double t) {
	double t_1 = ((t * 2.0) / (-1.0 - t)) * ((t * 2.0) / (t - -1.0));
	return (1.0 - t_1) / (2.0 - t_1);
}
real(8) function code(t)
    real(8), intent (in) :: t
    real(8) :: t_1
    t_1 = ((t * 2.0d0) / ((-1.0d0) - t)) * ((t * 2.0d0) / (t - (-1.0d0)))
    code = (1.0d0 - t_1) / (2.0d0 - t_1)
end function
public static double code(double t) {
	double t_1 = ((t * 2.0) / (-1.0 - t)) * ((t * 2.0) / (t - -1.0));
	return (1.0 - t_1) / (2.0 - t_1);
}
def code(t):
	t_1 = ((t * 2.0) / (-1.0 - t)) * ((t * 2.0) / (t - -1.0))
	return (1.0 - t_1) / (2.0 - t_1)
function code(t)
	t_1 = Float64(Float64(Float64(t * 2.0) / Float64(-1.0 - t)) * Float64(Float64(t * 2.0) / Float64(t - -1.0)))
	return Float64(Float64(1.0 - t_1) / Float64(2.0 - t_1))
end
function tmp = code(t)
	t_1 = ((t * 2.0) / (-1.0 - t)) * ((t * 2.0) / (t - -1.0));
	tmp = (1.0 - t_1) / (2.0 - t_1);
end
code[t_] := Block[{t$95$1 = N[(N[(N[(t * 2.0), $MachinePrecision] / N[(-1.0 - t), $MachinePrecision]), $MachinePrecision] * N[(N[(t * 2.0), $MachinePrecision] / N[(t - -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(N[(1.0 - t$95$1), $MachinePrecision] / N[(2.0 - t$95$1), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{t \cdot 2}{-1 - t} \cdot \frac{t \cdot 2}{t - -1}\\
\frac{1 - t\_1}{2 - t\_1}
\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%

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

Alternative 2: 99.6% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\ \;\;\;\;\frac{\mathsf{fma}\left(\frac{t \cdot t}{t - -1}, \frac{4}{t - -1}, 1\right)}{\frac{-4 \cdot \left(t \cdot t\right)}{\left(-1 - t\right) \cdot \left(t - -1\right)} + 2}\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222 - \frac{0.037037037037037035 + \frac{0.04938271604938271}{t}}{t}}{t}\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (<= (/ (* t 2.0) (- t -1.0)) 0.01)
   (/
    (fma (/ (* t t) (- t -1.0)) (/ 4.0 (- t -1.0)) 1.0)
    (+ (/ (* -4.0 (* t t)) (* (- -1.0 t) (- t -1.0))) 2.0))
   (-
    0.8333333333333334
    (/
     (-
      0.2222222222222222
      (/ (+ 0.037037037037037035 (/ 0.04938271604938271 t)) t))
     t))))
double code(double t) {
	double tmp;
	if (((t * 2.0) / (t - -1.0)) <= 0.01) {
		tmp = fma(((t * t) / (t - -1.0)), (4.0 / (t - -1.0)), 1.0) / (((-4.0 * (t * t)) / ((-1.0 - t) * (t - -1.0))) + 2.0);
	} else {
		tmp = 0.8333333333333334 - ((0.2222222222222222 - ((0.037037037037037035 + (0.04938271604938271 / t)) / t)) / t);
	}
	return tmp;
}
function code(t)
	tmp = 0.0
	if (Float64(Float64(t * 2.0) / Float64(t - -1.0)) <= 0.01)
		tmp = Float64(fma(Float64(Float64(t * t) / Float64(t - -1.0)), Float64(4.0 / Float64(t - -1.0)), 1.0) / Float64(Float64(Float64(-4.0 * Float64(t * t)) / Float64(Float64(-1.0 - t) * Float64(t - -1.0))) + 2.0));
	else
		tmp = Float64(0.8333333333333334 - Float64(Float64(0.2222222222222222 - Float64(Float64(0.037037037037037035 + Float64(0.04938271604938271 / t)) / t)) / t));
	end
	return tmp
end
code[t_] := If[LessEqual[N[(N[(t * 2.0), $MachinePrecision] / N[(t - -1.0), $MachinePrecision]), $MachinePrecision], 0.01], N[(N[(N[(N[(t * t), $MachinePrecision] / N[(t - -1.0), $MachinePrecision]), $MachinePrecision] * N[(4.0 / N[(t - -1.0), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / N[(N[(N[(-4.0 * N[(t * t), $MachinePrecision]), $MachinePrecision] / N[(N[(-1.0 - t), $MachinePrecision] * N[(t - -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], N[(0.8333333333333334 - N[(N[(0.2222222222222222 - N[(N[(0.037037037037037035 + N[(0.04938271604938271 / t), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\
\;\;\;\;\frac{\mathsf{fma}\left(\frac{t \cdot t}{t - -1}, \frac{4}{t - -1}, 1\right)}{\frac{-4 \cdot \left(t \cdot t\right)}{\left(-1 - t\right) \cdot \left(t - -1\right)} + 2}\\

\mathbf{else}:\\
\;\;\;\;0.8333333333333334 - \frac{0.2222222222222222 - \frac{0.037037037037037035 + \frac{0.04938271604938271}{t}}{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)) < 0.0100000000000000002

    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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\frac{\color{blue}{\left(t \cdot t\right) \cdot \left(2 \cdot 2\right)}}{\left(1 + t\right) \cdot \left(1 + t\right)} + 1}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      12. times-fracN/A

        \[\leadsto \frac{\color{blue}{\frac{t \cdot t}{1 + t} \cdot \frac{2 \cdot 2}{1 + t}} + 1}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      13. lower-fma.f64N/A

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

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

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

        \[\leadsto \frac{\mathsf{fma}\left(\frac{t \cdot t}{1 + t}, \color{blue}{\frac{2 \cdot 2}{1 + t}}, 1\right)}{2 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}} \]
      17. metadata-eval100.0

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    if 0.0100000000000000002 < (/.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 rewrites99.9%

      \[\leadsto \color{blue}{0.8333333333333334 - \frac{0.2222222222222222 - \frac{\frac{0.04938271604938271}{t} + 0.037037037037037035}{t}}{t}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification100.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\ \;\;\;\;\frac{\mathsf{fma}\left(\frac{t \cdot t}{t - -1}, \frac{4}{t - -1}, 1\right)}{\frac{-4 \cdot \left(t \cdot t\right)}{\left(-1 - t\right) \cdot \left(t - -1\right)} + 2}\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222 - \frac{0.037037037037037035 + \frac{0.04938271604938271}{t}}{t}}{t}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 99.5% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t\\ \mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\ \;\;\;\;\frac{1 + t\_1}{t\_1 + 2}\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222 - \frac{0.037037037037037035 + \frac{0.04938271604938271}{t}}{t}}{t}\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (let* ((t_1 (* (* (fma (fma (fma -16.0 t 12.0) t -8.0) t 4.0) t) t)))
   (if (<= (/ (* t 2.0) (- t -1.0)) 0.01)
     (/ (+ 1.0 t_1) (+ t_1 2.0))
     (-
      0.8333333333333334
      (/
       (-
        0.2222222222222222
        (/ (+ 0.037037037037037035 (/ 0.04938271604938271 t)) t))
       t)))))
double code(double t) {
	double t_1 = (fma(fma(fma(-16.0, t, 12.0), t, -8.0), t, 4.0) * t) * t;
	double tmp;
	if (((t * 2.0) / (t - -1.0)) <= 0.01) {
		tmp = (1.0 + t_1) / (t_1 + 2.0);
	} else {
		tmp = 0.8333333333333334 - ((0.2222222222222222 - ((0.037037037037037035 + (0.04938271604938271 / t)) / t)) / t);
	}
	return tmp;
}
function code(t)
	t_1 = Float64(Float64(fma(fma(fma(-16.0, t, 12.0), t, -8.0), t, 4.0) * t) * t)
	tmp = 0.0
	if (Float64(Float64(t * 2.0) / Float64(t - -1.0)) <= 0.01)
		tmp = Float64(Float64(1.0 + t_1) / Float64(t_1 + 2.0));
	else
		tmp = Float64(0.8333333333333334 - Float64(Float64(0.2222222222222222 - Float64(Float64(0.037037037037037035 + Float64(0.04938271604938271 / t)) / t)) / t));
	end
	return tmp
end
code[t_] := Block[{t$95$1 = N[(N[(N[(N[(N[(-16.0 * t + 12.0), $MachinePrecision] * t + -8.0), $MachinePrecision] * t + 4.0), $MachinePrecision] * t), $MachinePrecision] * t), $MachinePrecision]}, If[LessEqual[N[(N[(t * 2.0), $MachinePrecision] / N[(t - -1.0), $MachinePrecision]), $MachinePrecision], 0.01], N[(N[(1.0 + t$95$1), $MachinePrecision] / N[(t$95$1 + 2.0), $MachinePrecision]), $MachinePrecision], N[(0.8333333333333334 - N[(N[(0.2222222222222222 - N[(N[(0.037037037037037035 + N[(0.04938271604938271 / t), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t\\
\mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\
\;\;\;\;\frac{1 + t\_1}{t\_1 + 2}\\

\mathbf{else}:\\
\;\;\;\;0.8333333333333334 - \frac{0.2222222222222222 - \frac{0.037037037037037035 + \frac{0.04938271604938271}{t}}{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)) < 0.0100000000000000002

    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

      \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \color{blue}{{t}^{2} \cdot \left(4 + t \cdot \left(t \cdot \left(12 + -16 \cdot t\right) - 8\right)\right)}} \]
    4. Step-by-step derivation
      1. unpow2N/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \color{blue}{\left(t \cdot t\right)} \cdot \left(4 + t \cdot \left(t \cdot \left(12 + -16 \cdot t\right) - 8\right)\right)} \]
      2. associate-*l*N/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \color{blue}{t \cdot \left(t \cdot \left(4 + t \cdot \left(t \cdot \left(12 + -16 \cdot t\right) - 8\right)\right)\right)}} \]
      3. *-commutativeN/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \color{blue}{\left(t \cdot \left(4 + t \cdot \left(t \cdot \left(12 + -16 \cdot t\right) - 8\right)\right)\right) \cdot t}} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \color{blue}{\left(t \cdot \left(4 + t \cdot \left(t \cdot \left(12 + -16 \cdot t\right) - 8\right)\right)\right) \cdot t}} \]
      5. *-commutativeN/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \color{blue}{\left(\left(4 + t \cdot \left(t \cdot \left(12 + -16 \cdot t\right) - 8\right)\right) \cdot t\right)} \cdot t} \]
      6. lower-*.f64N/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \color{blue}{\left(\left(4 + t \cdot \left(t \cdot \left(12 + -16 \cdot t\right) - 8\right)\right) \cdot t\right)} \cdot t} \]
      7. +-commutativeN/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \left(\color{blue}{\left(t \cdot \left(t \cdot \left(12 + -16 \cdot t\right) - 8\right) + 4\right)} \cdot t\right) \cdot t} \]
      8. *-commutativeN/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \left(\left(\color{blue}{\left(t \cdot \left(12 + -16 \cdot t\right) - 8\right) \cdot t} + 4\right) \cdot t\right) \cdot t} \]
      9. lower-fma.f64N/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \left(\color{blue}{\mathsf{fma}\left(t \cdot \left(12 + -16 \cdot t\right) - 8, t, 4\right)} \cdot t\right) \cdot t} \]
      10. sub-negN/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \left(\mathsf{fma}\left(\color{blue}{t \cdot \left(12 + -16 \cdot t\right) + \left(\mathsf{neg}\left(8\right)\right)}, t, 4\right) \cdot t\right) \cdot t} \]
      11. *-commutativeN/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \left(\mathsf{fma}\left(\color{blue}{\left(12 + -16 \cdot t\right) \cdot t} + \left(\mathsf{neg}\left(8\right)\right), t, 4\right) \cdot t\right) \cdot t} \]
      12. metadata-evalN/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \left(\mathsf{fma}\left(\left(12 + -16 \cdot t\right) \cdot t + \color{blue}{-8}, t, 4\right) \cdot t\right) \cdot t} \]
      13. lower-fma.f64N/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \left(\mathsf{fma}\left(\color{blue}{\mathsf{fma}\left(12 + -16 \cdot t, t, -8\right)}, t, 4\right) \cdot t\right) \cdot t} \]
      14. +-commutativeN/A

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\color{blue}{-16 \cdot t + 12}, t, -8\right), t, 4\right) \cdot t\right) \cdot t} \]
      15. lower-fma.f6499.4

        \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\color{blue}{\mathsf{fma}\left(-16, t, 12\right)}, t, -8\right), t, 4\right) \cdot t\right) \cdot t} \]
    5. Applied rewrites99.4%

      \[\leadsto \frac{1 + \frac{2 \cdot t}{1 + t} \cdot \frac{2 \cdot t}{1 + t}}{2 + \color{blue}{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t}} \]
    6. Taylor expanded in t around 0

      \[\leadsto \frac{1 + \color{blue}{{t}^{2} \cdot \left(4 + t \cdot \left(t \cdot \left(12 + -16 \cdot t\right) - 8\right)\right)}}{2 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t} \]
    7. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \frac{1 + \color{blue}{\left(4 + t \cdot \left(t \cdot \left(12 + -16 \cdot t\right) - 8\right)\right) \cdot {t}^{2}}}{2 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t} \]
      2. unpow2N/A

        \[\leadsto \frac{1 + \left(4 + t \cdot \left(t \cdot \left(12 + -16 \cdot t\right) - 8\right)\right) \cdot \color{blue}{\left(t \cdot t\right)}}{2 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t} \]
      3. associate-*r*N/A

        \[\leadsto \frac{1 + \color{blue}{\left(\left(4 + t \cdot \left(t \cdot \left(12 + -16 \cdot t\right) - 8\right)\right) \cdot t\right) \cdot t}}{2 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t} \]
      4. *-commutativeN/A

        \[\leadsto \frac{1 + \color{blue}{\left(t \cdot \left(4 + t \cdot \left(t \cdot \left(12 + -16 \cdot t\right) - 8\right)\right)\right)} \cdot t}{2 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t} \]
      5. lower-*.f64N/A

        \[\leadsto \frac{1 + \color{blue}{\left(t \cdot \left(4 + t \cdot \left(t \cdot \left(12 + -16 \cdot t\right) - 8\right)\right)\right) \cdot t}}{2 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t} \]
      6. *-commutativeN/A

        \[\leadsto \frac{1 + \color{blue}{\left(\left(4 + t \cdot \left(t \cdot \left(12 + -16 \cdot t\right) - 8\right)\right) \cdot t\right)} \cdot t}{2 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t} \]
      7. lower-*.f64N/A

        \[\leadsto \frac{1 + \color{blue}{\left(\left(4 + t \cdot \left(t \cdot \left(12 + -16 \cdot t\right) - 8\right)\right) \cdot t\right)} \cdot t}{2 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t} \]
      8. +-commutativeN/A

        \[\leadsto \frac{1 + \left(\color{blue}{\left(t \cdot \left(t \cdot \left(12 + -16 \cdot t\right) - 8\right) + 4\right)} \cdot t\right) \cdot t}{2 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t} \]
      9. *-commutativeN/A

        \[\leadsto \frac{1 + \left(\left(\color{blue}{\left(t \cdot \left(12 + -16 \cdot t\right) - 8\right) \cdot t} + 4\right) \cdot t\right) \cdot t}{2 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t} \]
      10. lower-fma.f64N/A

        \[\leadsto \frac{1 + \left(\color{blue}{\mathsf{fma}\left(t \cdot \left(12 + -16 \cdot t\right) - 8, t, 4\right)} \cdot t\right) \cdot t}{2 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t} \]
      11. sub-negN/A

        \[\leadsto \frac{1 + \left(\mathsf{fma}\left(\color{blue}{t \cdot \left(12 + -16 \cdot t\right) + \left(\mathsf{neg}\left(8\right)\right)}, t, 4\right) \cdot t\right) \cdot t}{2 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t} \]
      12. *-commutativeN/A

        \[\leadsto \frac{1 + \left(\mathsf{fma}\left(\color{blue}{\left(12 + -16 \cdot t\right) \cdot t} + \left(\mathsf{neg}\left(8\right)\right), t, 4\right) \cdot t\right) \cdot t}{2 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t} \]
      13. metadata-evalN/A

        \[\leadsto \frac{1 + \left(\mathsf{fma}\left(\left(12 + -16 \cdot t\right) \cdot t + \color{blue}{-8}, t, 4\right) \cdot t\right) \cdot t}{2 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t} \]
      14. lower-fma.f64N/A

        \[\leadsto \frac{1 + \left(\mathsf{fma}\left(\color{blue}{\mathsf{fma}\left(12 + -16 \cdot t, t, -8\right)}, t, 4\right) \cdot t\right) \cdot t}{2 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t} \]
      15. +-commutativeN/A

        \[\leadsto \frac{1 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\color{blue}{-16 \cdot t + 12}, t, -8\right), t, 4\right) \cdot t\right) \cdot t}{2 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t} \]
      16. lower-fma.f6499.4

        \[\leadsto \frac{1 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\color{blue}{\mathsf{fma}\left(-16, t, 12\right)}, t, -8\right), t, 4\right) \cdot t\right) \cdot t}{2 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t} \]
    8. Applied rewrites99.4%

      \[\leadsto \frac{1 + \color{blue}{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t}}{2 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t} \]

    if 0.0100000000000000002 < (/.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 rewrites99.9%

      \[\leadsto \color{blue}{0.8333333333333334 - \frac{0.2222222222222222 - \frac{\frac{0.04938271604938271}{t} + 0.037037037037037035}{t}}{t}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\ \;\;\;\;\frac{1 + \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t}{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-16, t, 12\right), t, -8\right), t, 4\right) \cdot t\right) \cdot t + 2}\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222 - \frac{0.037037037037037035 + \frac{0.04938271604938271}{t}}{t}}{t}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 99.5% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(t - 2, t, 1\right), t \cdot t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222 - \frac{0.037037037037037035 + \frac{0.04938271604938271}{t}}{t}}{t}\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (<= (/ (* t 2.0) (- t -1.0)) 0.01)
   (fma (fma (- t 2.0) t 1.0) (* t t) 0.5)
   (-
    0.8333333333333334
    (/
     (-
      0.2222222222222222
      (/ (+ 0.037037037037037035 (/ 0.04938271604938271 t)) t))
     t))))
double code(double t) {
	double tmp;
	if (((t * 2.0) / (t - -1.0)) <= 0.01) {
		tmp = fma(fma((t - 2.0), t, 1.0), (t * t), 0.5);
	} else {
		tmp = 0.8333333333333334 - ((0.2222222222222222 - ((0.037037037037037035 + (0.04938271604938271 / t)) / t)) / t);
	}
	return tmp;
}
function code(t)
	tmp = 0.0
	if (Float64(Float64(t * 2.0) / Float64(t - -1.0)) <= 0.01)
		tmp = fma(fma(Float64(t - 2.0), t, 1.0), Float64(t * t), 0.5);
	else
		tmp = Float64(0.8333333333333334 - Float64(Float64(0.2222222222222222 - Float64(Float64(0.037037037037037035 + Float64(0.04938271604938271 / t)) / t)) / t));
	end
	return tmp
end
code[t_] := If[LessEqual[N[(N[(t * 2.0), $MachinePrecision] / N[(t - -1.0), $MachinePrecision]), $MachinePrecision], 0.01], N[(N[(N[(t - 2.0), $MachinePrecision] * t + 1.0), $MachinePrecision] * N[(t * t), $MachinePrecision] + 0.5), $MachinePrecision], N[(0.8333333333333334 - N[(N[(0.2222222222222222 - N[(N[(0.037037037037037035 + N[(0.04938271604938271 / t), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\
\;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(t - 2, t, 1\right), t \cdot t, 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;0.8333333333333334 - \frac{0.2222222222222222 - \frac{0.037037037037037035 + \frac{0.04938271604938271}{t}}{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)) < 0.0100000000000000002

    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

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(t - 2, t, 1\right), \color{blue}{t \cdot t}, \frac{1}{2}\right) \]
      9. lower-*.f6499.3

        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(t - 2, t, 1\right), \color{blue}{t \cdot t}, 0.5\right) \]
    5. Applied rewrites99.3%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(t - 2, t, 1\right), t \cdot t, 0.5\right)} \]

    if 0.0100000000000000002 < (/.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 rewrites99.9%

      \[\leadsto \color{blue}{0.8333333333333334 - \frac{0.2222222222222222 - \frac{\frac{0.04938271604938271}{t} + 0.037037037037037035}{t}}{t}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(t - 2, t, 1\right), t \cdot t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222 - \frac{0.037037037037037035 + \frac{0.04938271604938271}{t}}{t}}{t}\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 99.4% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(t - 2, t, 1\right), t \cdot t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222 - \frac{0.037037037037037035}{t}}{t}\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (<= (/ (* t 2.0) (- t -1.0)) 0.01)
   (fma (fma (- t 2.0) t 1.0) (* t t) 0.5)
   (-
    0.8333333333333334
    (/ (- 0.2222222222222222 (/ 0.037037037037037035 t)) t))))
double code(double t) {
	double tmp;
	if (((t * 2.0) / (t - -1.0)) <= 0.01) {
		tmp = fma(fma((t - 2.0), t, 1.0), (t * t), 0.5);
	} else {
		tmp = 0.8333333333333334 - ((0.2222222222222222 - (0.037037037037037035 / t)) / t);
	}
	return tmp;
}
function code(t)
	tmp = 0.0
	if (Float64(Float64(t * 2.0) / Float64(t - -1.0)) <= 0.01)
		tmp = fma(fma(Float64(t - 2.0), t, 1.0), Float64(t * t), 0.5);
	else
		tmp = Float64(0.8333333333333334 - Float64(Float64(0.2222222222222222 - Float64(0.037037037037037035 / t)) / t));
	end
	return tmp
end
code[t_] := If[LessEqual[N[(N[(t * 2.0), $MachinePrecision] / N[(t - -1.0), $MachinePrecision]), $MachinePrecision], 0.01], N[(N[(N[(t - 2.0), $MachinePrecision] * t + 1.0), $MachinePrecision] * N[(t * t), $MachinePrecision] + 0.5), $MachinePrecision], N[(0.8333333333333334 - N[(N[(0.2222222222222222 - N[(0.037037037037037035 / t), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\
\;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(t - 2, t, 1\right), t \cdot t, 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;0.8333333333333334 - \frac{0.2222222222222222 - \frac{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)) < 0.0100000000000000002

    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

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(t - 2, t, 1\right), \color{blue}{t \cdot t}, \frac{1}{2}\right) \]
      9. lower-*.f6499.3

        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(t - 2, t, 1\right), \color{blue}{t \cdot t}, 0.5\right) \]
    5. Applied rewrites99.3%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(t - 2, t, 1\right), t \cdot t, 0.5\right)} \]

    if 0.0100000000000000002 < (/.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. lower--.f64N/A

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

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

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

        \[\leadsto \frac{5}{6} - \frac{\frac{2}{9} - \color{blue}{\frac{\frac{1}{27} \cdot 1}{t}}}{t} \]
      16. metadata-evalN/A

        \[\leadsto \frac{5}{6} - \frac{\frac{2}{9} - \frac{\color{blue}{\frac{1}{27}}}{t}}{t} \]
      17. lower-/.f6499.7

        \[\leadsto 0.8333333333333334 - \frac{0.2222222222222222 - \color{blue}{\frac{0.037037037037037035}{t}}}{t} \]
    5. Applied rewrites99.7%

      \[\leadsto \color{blue}{0.8333333333333334 - \frac{0.2222222222222222 - \frac{0.037037037037037035}{t}}{t}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(t - 2, t, 1\right), t \cdot t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222 - \frac{0.037037037037037035}{t}}{t}\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 99.2% accurate, 2.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(t - 2, t, 1\right), t \cdot t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (<= (/ (* t 2.0) (- t -1.0)) 0.01)
   (fma (fma (- t 2.0) t 1.0) (* t t) 0.5)
   (- 0.8333333333333334 (/ 0.2222222222222222 t))))
double code(double t) {
	double tmp;
	if (((t * 2.0) / (t - -1.0)) <= 0.01) {
		tmp = fma(fma((t - 2.0), t, 1.0), (t * t), 0.5);
	} else {
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	}
	return tmp;
}
function code(t)
	tmp = 0.0
	if (Float64(Float64(t * 2.0) / Float64(t - -1.0)) <= 0.01)
		tmp = fma(fma(Float64(t - 2.0), t, 1.0), Float64(t * t), 0.5);
	else
		tmp = Float64(0.8333333333333334 - Float64(0.2222222222222222 / t));
	end
	return tmp
end
code[t_] := If[LessEqual[N[(N[(t * 2.0), $MachinePrecision] / N[(t - -1.0), $MachinePrecision]), $MachinePrecision], 0.01], N[(N[(N[(t - 2.0), $MachinePrecision] * t + 1.0), $MachinePrecision] * N[(t * t), $MachinePrecision] + 0.5), $MachinePrecision], N[(0.8333333333333334 - N[(0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\
\;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(t - 2, t, 1\right), t \cdot 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)) < 0.0100000000000000002

    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

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(t - 2, t, 1\right), \color{blue}{t \cdot t}, \frac{1}{2}\right) \]
      9. lower-*.f6499.3

        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(t - 2, t, 1\right), \color{blue}{t \cdot t}, 0.5\right) \]
    5. Applied rewrites99.3%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(t - 2, t, 1\right), t \cdot t, 0.5\right)} \]

    if 0.0100000000000000002 < (/.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. lower--.f64N/A

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

        \[\leadsto \frac{5}{6} - \color{blue}{\frac{\frac{2}{9} \cdot 1}{t}} \]
      3. metadata-evalN/A

        \[\leadsto \frac{5}{6} - \frac{\color{blue}{\frac{2}{9}}}{t} \]
      4. lower-/.f6499.2

        \[\leadsto 0.8333333333333334 - \color{blue}{\frac{0.2222222222222222}{t}} \]
    5. Applied rewrites99.2%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(t - 2, t, 1\right), t \cdot t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 99.2% accurate, 2.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(-2, t, 1\right), t \cdot t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (<= (/ (* t 2.0) (- t -1.0)) 0.01)
   (fma (fma -2.0 t 1.0) (* t t) 0.5)
   (- 0.8333333333333334 (/ 0.2222222222222222 t))))
double code(double t) {
	double tmp;
	if (((t * 2.0) / (t - -1.0)) <= 0.01) {
		tmp = fma(fma(-2.0, t, 1.0), (t * t), 0.5);
	} else {
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	}
	return tmp;
}
function code(t)
	tmp = 0.0
	if (Float64(Float64(t * 2.0) / Float64(t - -1.0)) <= 0.01)
		tmp = fma(fma(-2.0, t, 1.0), Float64(t * t), 0.5);
	else
		tmp = Float64(0.8333333333333334 - Float64(0.2222222222222222 / t));
	end
	return tmp
end
code[t_] := If[LessEqual[N[(N[(t * 2.0), $MachinePrecision] / N[(t - -1.0), $MachinePrecision]), $MachinePrecision], 0.01], N[(N[(-2.0 * t + 1.0), $MachinePrecision] * N[(t * t), $MachinePrecision] + 0.5), $MachinePrecision], N[(0.8333333333333334 - N[(0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\
\;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(-2, t, 1\right), t \cdot 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)) < 0.0100000000000000002

    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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(-2, t, 1\right), \color{blue}{t \cdot t}, 0.5\right) \]
    5. Applied rewrites99.2%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(-2, t, 1\right), t \cdot t, 0.5\right)} \]

    if 0.0100000000000000002 < (/.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. lower--.f64N/A

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

        \[\leadsto \frac{5}{6} - \color{blue}{\frac{\frac{2}{9} \cdot 1}{t}} \]
      3. metadata-evalN/A

        \[\leadsto \frac{5}{6} - \frac{\color{blue}{\frac{2}{9}}}{t} \]
      4. lower-/.f6499.2

        \[\leadsto 0.8333333333333334 - \color{blue}{\frac{0.2222222222222222}{t}} \]
    5. Applied rewrites99.2%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(-2, t, 1\right), t \cdot t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\ \end{array} \]
  5. Add Preprocessing

Alternative 8: 99.1% accurate, 2.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\ \;\;\;\;\mathsf{fma}\left(t, t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (<= (/ (* t 2.0) (- t -1.0)) 0.01)
   (fma t t 0.5)
   (- 0.8333333333333334 (/ 0.2222222222222222 t))))
double code(double t) {
	double tmp;
	if (((t * 2.0) / (t - -1.0)) <= 0.01) {
		tmp = fma(t, t, 0.5);
	} else {
		tmp = 0.8333333333333334 - (0.2222222222222222 / t);
	}
	return tmp;
}
function code(t)
	tmp = 0.0
	if (Float64(Float64(t * 2.0) / Float64(t - -1.0)) <= 0.01)
		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[(t * 2.0), $MachinePrecision] / N[(t - -1.0), $MachinePrecision]), $MachinePrecision], 0.01], N[(t * t + 0.5), $MachinePrecision], N[(0.8333333333333334 - N[(0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\
\;\;\;\;\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)) < 0.0100000000000000002

    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.f6498.9

        \[\leadsto \color{blue}{\mathsf{fma}\left(t, t, 0.5\right)} \]
    5. Applied rewrites98.9%

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

    if 0.0100000000000000002 < (/.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. lower--.f64N/A

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

        \[\leadsto \frac{5}{6} - \color{blue}{\frac{\frac{2}{9} \cdot 1}{t}} \]
      3. metadata-evalN/A

        \[\leadsto \frac{5}{6} - \frac{\color{blue}{\frac{2}{9}}}{t} \]
      4. lower-/.f6499.2

        \[\leadsto 0.8333333333333334 - \color{blue}{\frac{0.2222222222222222}{t}} \]
    5. Applied rewrites99.2%

      \[\leadsto \color{blue}{0.8333333333333334 - \frac{0.2222222222222222}{t}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\ \;\;\;\;\mathsf{fma}\left(t, t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\ \end{array} \]
  5. Add Preprocessing

Alternative 9: 98.6% accurate, 3.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\ \;\;\;\;\mathsf{fma}\left(t, t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334\\ \end{array} \end{array} \]
(FPCore (t)
 :precision binary64
 (if (<= (/ (* t 2.0) (- t -1.0)) 0.01) (fma t t 0.5) 0.8333333333333334))
double code(double t) {
	double tmp;
	if (((t * 2.0) / (t - -1.0)) <= 0.01) {
		tmp = fma(t, t, 0.5);
	} else {
		tmp = 0.8333333333333334;
	}
	return tmp;
}
function code(t)
	tmp = 0.0
	if (Float64(Float64(t * 2.0) / Float64(t - -1.0)) <= 0.01)
		tmp = fma(t, t, 0.5);
	else
		tmp = 0.8333333333333334;
	end
	return tmp
end
code[t_] := If[LessEqual[N[(N[(t * 2.0), $MachinePrecision] / N[(t - -1.0), $MachinePrecision]), $MachinePrecision], 0.01], N[(t * t + 0.5), $MachinePrecision], 0.8333333333333334]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\
\;\;\;\;\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)) < 0.0100000000000000002

    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.f6498.9

        \[\leadsto \color{blue}{\mathsf{fma}\left(t, t, 0.5\right)} \]
    5. Applied rewrites98.9%

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

    if 0.0100000000000000002 < (/.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 rewrites97.8%

        \[\leadsto \color{blue}{0.8333333333333334} \]
    5. Recombined 2 regimes into one program.
    6. Final simplification98.4%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 0.01:\\ \;\;\;\;\mathsf{fma}\left(t, t, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334\\ \end{array} \]
    7. Add Preprocessing

    Alternative 10: 98.5% accurate, 4.0× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{t \cdot 2}{t - -1} \leq 1:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;0.8333333333333334\\ \end{array} \end{array} \]
    (FPCore (t)
     :precision binary64
     (if (<= (/ (* t 2.0) (- t -1.0)) 1.0) 0.5 0.8333333333333334))
    double code(double t) {
    	double tmp;
    	if (((t * 2.0) / (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 (((t * 2.0d0) / (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 (((t * 2.0) / (t - -1.0)) <= 1.0) {
    		tmp = 0.5;
    	} else {
    		tmp = 0.8333333333333334;
    	}
    	return tmp;
    }
    
    def code(t):
    	tmp = 0
    	if ((t * 2.0) / (t - -1.0)) <= 1.0:
    		tmp = 0.5
    	else:
    		tmp = 0.8333333333333334
    	return tmp
    
    function code(t)
    	tmp = 0.0
    	if (Float64(Float64(t * 2.0) / 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 (((t * 2.0) / (t - -1.0)) <= 1.0)
    		tmp = 0.5;
    	else
    		tmp = 0.8333333333333334;
    	end
    	tmp_2 = tmp;
    end
    
    code[t_] := If[LessEqual[N[(N[(t * 2.0), $MachinePrecision] / N[(t - -1.0), $MachinePrecision]), $MachinePrecision], 1.0], 0.5, 0.8333333333333334]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;\frac{t \cdot 2}{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 rewrites98.6%

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

        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 rewrites97.8%

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

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

        Alternative 11: 58.6% 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 rewrites59.4%

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

          Reproduce

          ?
          herbie shell --seed 2024273 
          (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))))))