Lanczos kernel

Percentage Accurate: 98.0% → 98.0%
Time: 11.2s
Alternatives: 9
Speedup: 1.0×

Specification

?
\[\left(10^{-5} \leq x \land x \leq 1\right) \land \left(1 \leq tau \land tau \leq 5\right)\]
\[\begin{array}{l} \\ \begin{array}{l} t_1 := x \cdot \mathsf{PI}\left(\right)\\ t_2 := t\_1 \cdot tau\\ \frac{\sin t\_2}{t\_2} \cdot \frac{\sin t\_1}{t\_1} \end{array} \end{array} \]
(FPCore (x tau)
 :precision binary32
 (let* ((t_1 (* x (PI))) (t_2 (* t_1 tau)))
   (* (/ (sin t_2) t_2) (/ (sin t_1) t_1))))
\begin{array}{l}

\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
t_2 := t\_1 \cdot tau\\
\frac{\sin t\_2}{t\_2} \cdot \frac{\sin t\_1}{t\_1}
\end{array}
\end{array}

Sampling outcomes in binary32 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 9 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: 98.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := x \cdot \mathsf{PI}\left(\right)\\ t_2 := t\_1 \cdot tau\\ \frac{\sin t\_2}{t\_2} \cdot \frac{\sin t\_1}{t\_1} \end{array} \end{array} \]
(FPCore (x tau)
 :precision binary32
 (let* ((t_1 (* x (PI))) (t_2 (* t_1 tau)))
   (* (/ (sin t_2) t_2) (/ (sin t_1) t_1))))
\begin{array}{l}

\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
t_2 := t\_1 \cdot tau\\
\frac{\sin t\_2}{t\_2} \cdot \frac{\sin t\_1}{t\_1}
\end{array}
\end{array}

Alternative 1: 98.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \mathsf{PI}\left(\right) \cdot x\\ t_2 := t\_1 \cdot tau\\ \frac{\sin t\_1}{t\_1} \cdot \frac{\sin t\_2}{t\_2} \end{array} \end{array} \]
(FPCore (x tau)
 :precision binary32
 (let* ((t_1 (* (PI) x)) (t_2 (* t_1 tau)))
   (* (/ (sin t_1) t_1) (/ (sin t_2) t_2))))
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \mathsf{PI}\left(\right) \cdot x\\
t_2 := t\_1 \cdot tau\\
\frac{\sin t\_1}{t\_1} \cdot \frac{\sin t\_2}{t\_2}
\end{array}
\end{array}
Derivation
  1. Initial program 97.7%

    \[\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)} \]
  2. Add Preprocessing
  3. Final simplification97.7%

    \[\leadsto \frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\mathsf{PI}\left(\right) \cdot x} \cdot \frac{\sin \left(\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\right)}{\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau} \]
  4. Add Preprocessing

Alternative 2: 97.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \mathsf{PI}\left(\right) \cdot x\\ t_2 := t\_1 \cdot tau\\ \frac{\sin t\_2 \cdot \sin t\_1}{t\_2 \cdot t\_1} \end{array} \end{array} \]
(FPCore (x tau)
 :precision binary32
 (let* ((t_1 (* (PI) x)) (t_2 (* t_1 tau)))
   (/ (* (sin t_2) (sin t_1)) (* t_2 t_1))))
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \mathsf{PI}\left(\right) \cdot x\\
t_2 := t\_1 \cdot tau\\
\frac{\sin t\_2 \cdot \sin t\_1}{t\_2 \cdot t\_1}
\end{array}
\end{array}
Derivation
  1. Initial program 97.7%

    \[\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-*.f32N/A

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)}} \]
    2. lift-/.f32N/A

      \[\leadsto \frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \color{blue}{\frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)}} \]
    3. associate-*r/N/A

      \[\leadsto \color{blue}{\frac{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)}} \]
    4. lower-/.f32N/A

      \[\leadsto \color{blue}{\frac{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)}} \]
  4. Applied rewrites97.5%

    \[\leadsto \color{blue}{\frac{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\mathsf{PI}\left(\right) \cdot x}} \]
  5. Step-by-step derivation
    1. lift-/.f32N/A

      \[\leadsto \color{blue}{\frac{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\mathsf{PI}\left(\right) \cdot x}} \]
    2. lift-*.f32N/A

      \[\leadsto \frac{\color{blue}{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}}{\mathsf{PI}\left(\right) \cdot x} \]
    3. *-commutativeN/A

      \[\leadsto \frac{\color{blue}{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right) \cdot \frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)}}}{\mathsf{PI}\left(\right) \cdot x} \]
    4. associate-*l/N/A

      \[\leadsto \color{blue}{\frac{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\mathsf{PI}\left(\right) \cdot x} \cdot \frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)}} \]
    5. lift-/.f32N/A

      \[\leadsto \frac{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\mathsf{PI}\left(\right) \cdot x} \cdot \color{blue}{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)}} \]
    6. clear-numN/A

      \[\leadsto \color{blue}{\frac{1}{\frac{\mathsf{PI}\left(\right) \cdot x}{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}}} \cdot \frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)} \]
    7. frac-timesN/A

      \[\leadsto \color{blue}{\frac{1 \cdot \sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\frac{\mathsf{PI}\left(\right) \cdot x}{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)} \cdot \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}} \]
    8. *-lft-identityN/A

      \[\leadsto \frac{\color{blue}{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}}{\frac{\mathsf{PI}\left(\right) \cdot x}{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)} \cdot \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)} \]
    9. lower-/.f32N/A

      \[\leadsto \color{blue}{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\frac{\mathsf{PI}\left(\right) \cdot x}{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)} \cdot \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}} \]
  6. Applied rewrites97.6%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{\frac{x \cdot \mathsf{PI}\left(\right)}{\sin \left(tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)\right)} \cdot \left(tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)\right)}} \]
  7. Step-by-step derivation
    1. lift-/.f32N/A

      \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{\frac{x \cdot \mathsf{PI}\left(\right)}{\sin \left(tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)\right)} \cdot \left(tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)\right)}} \]
    2. lift-*.f32N/A

      \[\leadsto \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{\color{blue}{\frac{x \cdot \mathsf{PI}\left(\right)}{\sin \left(tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)\right)} \cdot \left(tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)\right)}} \]
    3. associate-/r*N/A

      \[\leadsto \color{blue}{\frac{\frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{\frac{x \cdot \mathsf{PI}\left(\right)}{\sin \left(tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)\right)}}}{tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)}} \]
    4. div-invN/A

      \[\leadsto \frac{\color{blue}{\sin \left(x \cdot \mathsf{PI}\left(\right)\right) \cdot \frac{1}{\frac{x \cdot \mathsf{PI}\left(\right)}{\sin \left(tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)\right)}}}}{tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)} \]
    5. lift-/.f32N/A

      \[\leadsto \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right) \cdot \frac{1}{\color{blue}{\frac{x \cdot \mathsf{PI}\left(\right)}{\sin \left(tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)\right)}}}}{tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)} \]
    6. clear-numN/A

      \[\leadsto \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right) \cdot \color{blue}{\frac{\sin \left(tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)\right)}{x \cdot \mathsf{PI}\left(\right)}}}{tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)} \]
    7. lift-*.f32N/A

      \[\leadsto \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right) \cdot \frac{\sin \left(tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)\right)}{x \cdot \mathsf{PI}\left(\right)}}{\color{blue}{tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)}} \]
    8. *-commutativeN/A

      \[\leadsto \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right) \cdot \frac{\sin \left(tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)\right)}{x \cdot \mathsf{PI}\left(\right)}}{\color{blue}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau}} \]
    9. frac-timesN/A

      \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)} \cdot \frac{\frac{\sin \left(tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)\right)}{x \cdot \mathsf{PI}\left(\right)}}{tau}} \]
  8. Applied rewrites97.6%

    \[\leadsto \color{blue}{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right) \cdot \left(-\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)\right)}{\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot \left(\left(-tau\right) \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}} \]
  9. Final simplification97.6%

    \[\leadsto \frac{\sin \left(\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\right) \cdot \sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\left(\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\right) \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)} \]
  10. Add Preprocessing

Alternative 3: 97.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \mathsf{PI}\left(\right) \cdot x\\ t_2 := t\_1 \cdot tau\\ \frac{\sin t\_2 \cdot \sin t\_1}{\left(t\_2 \cdot \mathsf{PI}\left(\right)\right) \cdot x} \end{array} \end{array} \]
(FPCore (x tau)
 :precision binary32
 (let* ((t_1 (* (PI) x)) (t_2 (* t_1 tau)))
   (/ (* (sin t_2) (sin t_1)) (* (* t_2 (PI)) x))))
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \mathsf{PI}\left(\right) \cdot x\\
t_2 := t\_1 \cdot tau\\
\frac{\sin t\_2 \cdot \sin t\_1}{\left(t\_2 \cdot \mathsf{PI}\left(\right)\right) \cdot x}
\end{array}
\end{array}
Derivation
  1. Initial program 97.7%

    \[\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-*.f32N/A

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)}} \]
    2. lift-/.f32N/A

      \[\leadsto \frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \color{blue}{\frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)}} \]
    3. associate-*r/N/A

      \[\leadsto \color{blue}{\frac{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)}} \]
    4. lower-/.f32N/A

      \[\leadsto \color{blue}{\frac{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)}} \]
  4. Applied rewrites97.5%

    \[\leadsto \color{blue}{\frac{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\mathsf{PI}\left(\right) \cdot x}} \]
  5. Step-by-step derivation
    1. lift-/.f32N/A

      \[\leadsto \color{blue}{\frac{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\mathsf{PI}\left(\right) \cdot x}} \]
    2. lift-*.f32N/A

      \[\leadsto \frac{\color{blue}{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}}{\mathsf{PI}\left(\right) \cdot x} \]
    3. *-commutativeN/A

      \[\leadsto \frac{\color{blue}{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right) \cdot \frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)}}}{\mathsf{PI}\left(\right) \cdot x} \]
    4. associate-*l/N/A

      \[\leadsto \color{blue}{\frac{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\mathsf{PI}\left(\right) \cdot x} \cdot \frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)}} \]
    5. lift-/.f32N/A

      \[\leadsto \frac{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\mathsf{PI}\left(\right) \cdot x} \cdot \color{blue}{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)}} \]
    6. clear-numN/A

      \[\leadsto \color{blue}{\frac{1}{\frac{\mathsf{PI}\left(\right) \cdot x}{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}}} \cdot \frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)} \]
    7. frac-timesN/A

      \[\leadsto \color{blue}{\frac{1 \cdot \sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\frac{\mathsf{PI}\left(\right) \cdot x}{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)} \cdot \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}} \]
    8. *-lft-identityN/A

      \[\leadsto \frac{\color{blue}{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}}{\frac{\mathsf{PI}\left(\right) \cdot x}{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)} \cdot \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)} \]
    9. lower-/.f32N/A

      \[\leadsto \color{blue}{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\frac{\mathsf{PI}\left(\right) \cdot x}{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)} \cdot \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}} \]
  6. Applied rewrites97.6%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{\frac{x \cdot \mathsf{PI}\left(\right)}{\sin \left(tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)\right)} \cdot \left(tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)\right)}} \]
  7. Applied rewrites97.1%

    \[\leadsto \color{blue}{\frac{\left(-\sin \left(\mathsf{PI}\left(\right) \cdot x\right)\right) \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\left(-x\right) \cdot \left(\left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right) \cdot \mathsf{PI}\left(\right)\right)}} \]
  8. Final simplification97.1%

    \[\leadsto \frac{\sin \left(\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\right) \cdot \sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\left(\left(\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\right) \cdot \mathsf{PI}\left(\right)\right) \cdot x} \]
  9. Add Preprocessing

Alternative 4: 71.2% accurate, 1.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \mathsf{PI}\left(\right) \cdot x\\ t_2 := t\_1 \cdot tau\\ t_3 := \sqrt{\mathsf{PI}\left(\right)}\\ \frac{\frac{\frac{\frac{t\_1}{t\_2} \cdot \sin t\_2}{x}}{t\_3}}{t\_3} \end{array} \end{array} \]
(FPCore (x tau)
 :precision binary32
 (let* ((t_1 (* (PI) x)) (t_2 (* t_1 tau)) (t_3 (sqrt (PI))))
   (/ (/ (/ (* (/ t_1 t_2) (sin t_2)) x) t_3) t_3)))
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \mathsf{PI}\left(\right) \cdot x\\
t_2 := t\_1 \cdot tau\\
t_3 := \sqrt{\mathsf{PI}\left(\right)}\\
\frac{\frac{\frac{\frac{t\_1}{t\_2} \cdot \sin t\_2}{x}}{t\_3}}{t\_3}
\end{array}
\end{array}
Derivation
  1. Initial program 97.7%

    \[\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-*.f32N/A

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)}} \]
    2. lift-/.f32N/A

      \[\leadsto \frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \color{blue}{\frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)}} \]
    3. associate-*r/N/A

      \[\leadsto \color{blue}{\frac{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)}} \]
    4. lift-*.f32N/A

      \[\leadsto \frac{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{\color{blue}{x \cdot \mathsf{PI}\left(\right)}} \]
    5. lift-PI.f32N/A

      \[\leadsto \frac{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \color{blue}{\mathsf{PI}\left(\right)}} \]
    6. add-sqr-sqrtN/A

      \[\leadsto \frac{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \color{blue}{\left(\sqrt{\mathsf{PI}\left(\right)} \cdot \sqrt{\mathsf{PI}\left(\right)}\right)}} \]
    7. associate-*r*N/A

      \[\leadsto \frac{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{\color{blue}{\left(x \cdot \sqrt{\mathsf{PI}\left(\right)}\right) \cdot \sqrt{\mathsf{PI}\left(\right)}}} \]
    8. associate-/r*N/A

      \[\leadsto \color{blue}{\frac{\frac{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \sqrt{\mathsf{PI}\left(\right)}}}{\sqrt{\mathsf{PI}\left(\right)}}} \]
    9. lower-/.f32N/A

      \[\leadsto \color{blue}{\frac{\frac{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \sqrt{\mathsf{PI}\left(\right)}}}{\sqrt{\mathsf{PI}\left(\right)}}} \]
  4. Applied rewrites97.1%

    \[\leadsto \color{blue}{\frac{\frac{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\sqrt{\mathsf{PI}\left(\right)} \cdot x}}{\sqrt{\mathsf{PI}\left(\right)}}} \]
  5. Step-by-step derivation
    1. lift-*.f32N/A

      \[\leadsto \frac{\frac{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\color{blue}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)}} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\sqrt{\mathsf{PI}\left(\right)} \cdot x}}{\sqrt{\mathsf{PI}\left(\right)}} \]
    2. lift-*.f32N/A

      \[\leadsto \frac{\frac{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{tau \cdot \color{blue}{\left(\mathsf{PI}\left(\right) \cdot x\right)}} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\sqrt{\mathsf{PI}\left(\right)} \cdot x}}{\sqrt{\mathsf{PI}\left(\right)}} \]
    3. associate-*r*N/A

      \[\leadsto \frac{\frac{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\color{blue}{\left(tau \cdot \mathsf{PI}\left(\right)\right) \cdot x}} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\sqrt{\mathsf{PI}\left(\right)} \cdot x}}{\sqrt{\mathsf{PI}\left(\right)}} \]
    4. lift-*.f32N/A

      \[\leadsto \frac{\frac{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\color{blue}{\left(tau \cdot \mathsf{PI}\left(\right)\right)} \cdot x} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\sqrt{\mathsf{PI}\left(\right)} \cdot x}}{\sqrt{\mathsf{PI}\left(\right)}} \]
    5. lower-*.f3296.6

      \[\leadsto \frac{\frac{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\color{blue}{\left(tau \cdot \mathsf{PI}\left(\right)\right) \cdot x}} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\sqrt{\mathsf{PI}\left(\right)} \cdot x}}{\sqrt{\mathsf{PI}\left(\right)}} \]
  6. Applied rewrites96.6%

    \[\leadsto \frac{\frac{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\color{blue}{\left(tau \cdot \mathsf{PI}\left(\right)\right) \cdot x}} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\sqrt{\mathsf{PI}\left(\right)} \cdot x}}{\sqrt{\mathsf{PI}\left(\right)}} \]
  7. Taylor expanded in x around 0

    \[\leadsto \frac{\frac{\frac{\color{blue}{x \cdot \mathsf{PI}\left(\right)}}{\left(tau \cdot \mathsf{PI}\left(\right)\right) \cdot x} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\sqrt{\mathsf{PI}\left(\right)} \cdot x}}{\sqrt{\mathsf{PI}\left(\right)}} \]
  8. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \frac{\frac{\frac{\color{blue}{\mathsf{PI}\left(\right) \cdot x}}{\left(tau \cdot \mathsf{PI}\left(\right)\right) \cdot x} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\sqrt{\mathsf{PI}\left(\right)} \cdot x}}{\sqrt{\mathsf{PI}\left(\right)}} \]
    2. lower-*.f32N/A

      \[\leadsto \frac{\frac{\frac{\color{blue}{\mathsf{PI}\left(\right) \cdot x}}{\left(tau \cdot \mathsf{PI}\left(\right)\right) \cdot x} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\sqrt{\mathsf{PI}\left(\right)} \cdot x}}{\sqrt{\mathsf{PI}\left(\right)}} \]
    3. lower-PI.f3270.0

      \[\leadsto \frac{\frac{\frac{\color{blue}{\mathsf{PI}\left(\right)} \cdot x}{\left(tau \cdot \mathsf{PI}\left(\right)\right) \cdot x} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\sqrt{\mathsf{PI}\left(\right)} \cdot x}}{\sqrt{\mathsf{PI}\left(\right)}} \]
  9. Applied rewrites70.0%

    \[\leadsto \frac{\frac{\frac{\color{blue}{\mathsf{PI}\left(\right) \cdot x}}{\left(tau \cdot \mathsf{PI}\left(\right)\right) \cdot x} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\sqrt{\mathsf{PI}\left(\right)} \cdot x}}{\sqrt{\mathsf{PI}\left(\right)}} \]
  10. Step-by-step derivation
    1. lift-/.f32N/A

      \[\leadsto \frac{\color{blue}{\frac{\frac{\mathsf{PI}\left(\right) \cdot x}{\left(tau \cdot \mathsf{PI}\left(\right)\right) \cdot x} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\sqrt{\mathsf{PI}\left(\right)} \cdot x}}}{\sqrt{\mathsf{PI}\left(\right)}} \]
    2. lift-*.f32N/A

      \[\leadsto \frac{\frac{\frac{\mathsf{PI}\left(\right) \cdot x}{\left(tau \cdot \mathsf{PI}\left(\right)\right) \cdot x} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\color{blue}{\sqrt{\mathsf{PI}\left(\right)} \cdot x}}}{\sqrt{\mathsf{PI}\left(\right)}} \]
    3. *-commutativeN/A

      \[\leadsto \frac{\frac{\frac{\mathsf{PI}\left(\right) \cdot x}{\left(tau \cdot \mathsf{PI}\left(\right)\right) \cdot x} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\color{blue}{x \cdot \sqrt{\mathsf{PI}\left(\right)}}}}{\sqrt{\mathsf{PI}\left(\right)}} \]
    4. associate-/r*N/A

      \[\leadsto \frac{\color{blue}{\frac{\frac{\frac{\mathsf{PI}\left(\right) \cdot x}{\left(tau \cdot \mathsf{PI}\left(\right)\right) \cdot x} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{x}}{\sqrt{\mathsf{PI}\left(\right)}}}}{\sqrt{\mathsf{PI}\left(\right)}} \]
    5. lower-/.f32N/A

      \[\leadsto \frac{\color{blue}{\frac{\frac{\frac{\mathsf{PI}\left(\right) \cdot x}{\left(tau \cdot \mathsf{PI}\left(\right)\right) \cdot x} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{x}}{\sqrt{\mathsf{PI}\left(\right)}}}}{\sqrt{\mathsf{PI}\left(\right)}} \]
  11. Applied rewrites70.3%

    \[\leadsto \frac{\color{blue}{\frac{\frac{\frac{\mathsf{PI}\left(\right) \cdot x}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{x}}{\sqrt{\mathsf{PI}\left(\right)}}}}{\sqrt{\mathsf{PI}\left(\right)}} \]
  12. Final simplification70.3%

    \[\leadsto \frac{\frac{\frac{\frac{\mathsf{PI}\left(\right) \cdot x}{\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau} \cdot \sin \left(\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\right)}{x}}{\sqrt{\mathsf{PI}\left(\right)}}}{\sqrt{\mathsf{PI}\left(\right)}} \]
  13. Add Preprocessing

Alternative 5: 71.3% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\\ \frac{1}{\frac{t\_1}{\sin t\_1}} \end{array} \end{array} \]
(FPCore (x tau)
 :precision binary32
 (let* ((t_1 (* (* (PI) x) tau))) (/ 1.0 (/ t_1 (sin t_1)))))
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\\
\frac{1}{\frac{t\_1}{\sin t\_1}}
\end{array}
\end{array}
Derivation
  1. Initial program 97.7%

    \[\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-*.f32N/A

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)}} \]
    2. *-commutativeN/A

      \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)} \cdot \frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau}} \]
    3. lift-/.f32N/A

      \[\leadsto \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)} \cdot \color{blue}{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau}} \]
    4. clear-numN/A

      \[\leadsto \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)} \cdot \color{blue}{\frac{1}{\frac{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau}{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}}} \]
    5. un-div-invN/A

      \[\leadsto \color{blue}{\frac{\frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)}}{\frac{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau}{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}}} \]
    6. lower-/.f32N/A

      \[\leadsto \color{blue}{\frac{\frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)}}{\frac{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau}{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}}} \]
    7. lift-*.f32N/A

      \[\leadsto \frac{\frac{\sin \color{blue}{\left(x \cdot \mathsf{PI}\left(\right)\right)}}{x \cdot \mathsf{PI}\left(\right)}}{\frac{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau}{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}} \]
    8. *-commutativeN/A

      \[\leadsto \frac{\frac{\sin \color{blue}{\left(\mathsf{PI}\left(\right) \cdot x\right)}}{x \cdot \mathsf{PI}\left(\right)}}{\frac{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau}{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}} \]
    9. lower-*.f32N/A

      \[\leadsto \frac{\frac{\sin \color{blue}{\left(\mathsf{PI}\left(\right) \cdot x\right)}}{x \cdot \mathsf{PI}\left(\right)}}{\frac{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau}{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}} \]
    10. lift-*.f32N/A

      \[\leadsto \frac{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\color{blue}{x \cdot \mathsf{PI}\left(\right)}}}{\frac{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau}{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}} \]
    11. *-commutativeN/A

      \[\leadsto \frac{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\color{blue}{\mathsf{PI}\left(\right) \cdot x}}}{\frac{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau}{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}} \]
    12. lower-*.f32N/A

      \[\leadsto \frac{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\color{blue}{\mathsf{PI}\left(\right) \cdot x}}}{\frac{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau}{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}} \]
    13. lower-/.f3297.6

      \[\leadsto \frac{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\mathsf{PI}\left(\right) \cdot x}}{\color{blue}{\frac{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau}{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}}} \]
  4. Applied rewrites97.6%

    \[\leadsto \color{blue}{\frac{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\mathsf{PI}\left(\right) \cdot x}}{\frac{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)}{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}}} \]
  5. Taylor expanded in x around 0

    \[\leadsto \frac{\color{blue}{1}}{\frac{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)}{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}} \]
  6. Step-by-step derivation
    1. Applied rewrites70.2%

      \[\leadsto \frac{\color{blue}{1}}{\frac{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)}{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}} \]
    2. Final simplification70.2%

      \[\leadsto \frac{1}{\frac{\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau}{\sin \left(\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\right)}} \]
    3. Add Preprocessing

    Alternative 6: 71.3% accurate, 1.8× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\\ \frac{\mathsf{PI}\left(\right) \cdot \sin t\_1}{t\_1 \cdot \mathsf{PI}\left(\right)} \end{array} \end{array} \]
    (FPCore (x tau)
     :precision binary32
     (let* ((t_1 (* (* (PI) x) tau))) (/ (* (PI) (sin t_1)) (* t_1 (PI)))))
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_1 := \left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\\
    \frac{\mathsf{PI}\left(\right) \cdot \sin t\_1}{t\_1 \cdot \mathsf{PI}\left(\right)}
    \end{array}
    \end{array}
    
    Derivation
    1. Initial program 97.7%

      \[\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-*.f32N/A

        \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)}} \]
      2. lift-/.f32N/A

        \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau}} \cdot \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)} \]
      3. lift-/.f32N/A

        \[\leadsto \frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \color{blue}{\frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)}} \]
      4. lift-*.f32N/A

        \[\leadsto \frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{\color{blue}{x \cdot \mathsf{PI}\left(\right)}} \]
      5. associate-/r*N/A

        \[\leadsto \frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \color{blue}{\frac{\frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x}}{\mathsf{PI}\left(\right)}} \]
      6. frac-timesN/A

        \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right) \cdot \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x}}{\left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right) \cdot \mathsf{PI}\left(\right)}} \]
      7. lower-/.f32N/A

        \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right) \cdot \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x}}{\left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right) \cdot \mathsf{PI}\left(\right)}} \]
    4. Applied rewrites97.4%

      \[\leadsto \color{blue}{\frac{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{x} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right) \cdot \mathsf{PI}\left(\right)}} \]
    5. Taylor expanded in x around 0

      \[\leadsto \frac{\color{blue}{\mathsf{PI}\left(\right)} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right) \cdot \mathsf{PI}\left(\right)} \]
    6. Step-by-step derivation
      1. lower-PI.f3270.2

        \[\leadsto \frac{\color{blue}{\mathsf{PI}\left(\right)} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right) \cdot \mathsf{PI}\left(\right)} \]
    7. Applied rewrites70.2%

      \[\leadsto \frac{\color{blue}{\mathsf{PI}\left(\right)} \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{\left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right) \cdot \mathsf{PI}\left(\right)} \]
    8. Final simplification70.2%

      \[\leadsto \frac{\mathsf{PI}\left(\right) \cdot \sin \left(\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\right)}{\left(\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\right) \cdot \mathsf{PI}\left(\right)} \]
    9. Add Preprocessing

    Alternative 7: 71.3% accurate, 1.9× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\\ 1 \cdot \frac{\sin t\_1}{t\_1} \end{array} \end{array} \]
    (FPCore (x tau)
     :precision binary32
     (let* ((t_1 (* (* (PI) x) tau))) (* 1.0 (/ (sin t_1) t_1))))
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_1 := \left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\\
    1 \cdot \frac{\sin t\_1}{t\_1}
    \end{array}
    \end{array}
    
    Derivation
    1. Initial program 97.7%

      \[\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \color{blue}{1} \]
    4. Step-by-step derivation
      1. Applied rewrites70.2%

        \[\leadsto \frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \color{blue}{1} \]
      2. Final simplification70.2%

        \[\leadsto 1 \cdot \frac{\sin \left(\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\right)}{\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau} \]
      3. Add Preprocessing

      Alternative 8: 64.8% accurate, 2.2× speedup?

      \[\begin{array}{l} \\ {\left(\mathsf{PI}\left(\right) \cdot x\right)}^{2} \cdot -0.16666666666666666 + 1 \end{array} \]
      (FPCore (x tau)
       :precision binary32
       (+ (* (pow (* (PI) x) 2.0) -0.16666666666666666) 1.0))
      \begin{array}{l}
      
      \\
      {\left(\mathsf{PI}\left(\right) \cdot x\right)}^{2} \cdot -0.16666666666666666 + 1
      \end{array}
      
      Derivation
      1. Initial program 97.7%

        \[\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)} \]
      2. Add Preprocessing
      3. Taylor expanded in x around 0

        \[\leadsto \color{blue}{1 + {x}^{2} \cdot \left(\frac{-1}{6} \cdot \left({tau}^{2} \cdot {\mathsf{PI}\left(\right)}^{2}\right) + \frac{-1}{6} \cdot {\mathsf{PI}\left(\right)}^{2}\right)} \]
      4. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto \color{blue}{{x}^{2} \cdot \left(\frac{-1}{6} \cdot \left({tau}^{2} \cdot {\mathsf{PI}\left(\right)}^{2}\right) + \frac{-1}{6} \cdot {\mathsf{PI}\left(\right)}^{2}\right) + 1} \]
        2. *-commutativeN/A

          \[\leadsto \color{blue}{\left(\frac{-1}{6} \cdot \left({tau}^{2} \cdot {\mathsf{PI}\left(\right)}^{2}\right) + \frac{-1}{6} \cdot {\mathsf{PI}\left(\right)}^{2}\right) \cdot {x}^{2}} + 1 \]
        3. lower-fma.f32N/A

          \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{-1}{6} \cdot \left({tau}^{2} \cdot {\mathsf{PI}\left(\right)}^{2}\right) + \frac{-1}{6} \cdot {\mathsf{PI}\left(\right)}^{2}, {x}^{2}, 1\right)} \]
      5. Applied rewrites61.9%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(tau, tau, 1\right) \cdot \left(\left(\mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right)\right) \cdot -0.16666666666666666\right), x \cdot x, 1\right)} \]
      6. Taylor expanded in tau around 0

        \[\leadsto 1 + \color{blue}{\frac{-1}{6} \cdot \left({x}^{2} \cdot {\mathsf{PI}\left(\right)}^{2}\right)} \]
      7. Step-by-step derivation
        1. Applied rewrites61.9%

          \[\leadsto \mathsf{fma}\left(\left(\left(-0.16666666666666666 \cdot x\right) \cdot x\right) \cdot \mathsf{PI}\left(\right), \color{blue}{\mathsf{PI}\left(\right)}, 1\right) \]
        2. Step-by-step derivation
          1. Applied rewrites63.1%

            \[\leadsto -0.16666666666666666 \cdot {\left(\mathsf{PI}\left(\right) \cdot x\right)}^{2} + 1 \]
          2. Final simplification63.1%

            \[\leadsto {\left(\mathsf{PI}\left(\right) \cdot x\right)}^{2} \cdot -0.16666666666666666 + 1 \]
          3. Add Preprocessing

          Alternative 9: 63.9% accurate, 258.0× speedup?

          \[\begin{array}{l} \\ 1 \end{array} \]
          (FPCore (x tau) :precision binary32 1.0)
          float code(float x, float tau) {
          	return 1.0f;
          }
          
          real(4) function code(x, tau)
              real(4), intent (in) :: x
              real(4), intent (in) :: tau
              code = 1.0e0
          end function
          
          function code(x, tau)
          	return Float32(1.0)
          end
          
          function tmp = code(x, tau)
          	tmp = single(1.0);
          end
          
          \begin{array}{l}
          
          \\
          1
          \end{array}
          
          Derivation
          1. Initial program 97.7%

            \[\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)} \]
          2. Add Preprocessing
          3. Taylor expanded in x around 0

            \[\leadsto \color{blue}{1} \]
          4. Step-by-step derivation
            1. Applied rewrites62.2%

              \[\leadsto \color{blue}{1} \]
            2. Add Preprocessing

            Reproduce

            ?
            herbie shell --seed 2024264 
            (FPCore (x tau)
              :name "Lanczos kernel"
              :precision binary32
              :pre (and (and (<= 1e-5 x) (<= x 1.0)) (and (<= 1.0 tau) (<= tau 5.0)))
              (* (/ (sin (* (* x (PI)) tau)) (* (* x (PI)) tau)) (/ (sin (* x (PI))) (* x (PI)))))