Lanczos kernel

Percentage Accurate: 98.0% → 98.0%
Time: 6.6s
Alternatives: 7
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 7 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 98.0%

    \[\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)} \]
  2. Add Preprocessing
  3. Final simplification98.0%

    \[\leadsto \frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\mathsf{PI}\left(\right) \cdot x} \cdot \frac{\sin \left(\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\right)}{\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau} \]
  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 98.0%

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

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

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

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

      \[\leadsto \frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \color{blue}{\left(\frac{1}{x \cdot \mathsf{PI}\left(\right)} \cdot \sin \left(x \cdot \mathsf{PI}\left(\right)\right)\right)} \]
    5. lower-/.f3297.7

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

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

      \[\leadsto \frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \left(\frac{1}{\color{blue}{\mathsf{PI}\left(\right) \cdot x}} \cdot \sin \left(x \cdot \mathsf{PI}\left(\right)\right)\right) \]
    8. lower-*.f3297.7

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

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

      \[\leadsto \frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \left(\frac{1}{\mathsf{PI}\left(\right) \cdot x} \cdot \sin \color{blue}{\left(\mathsf{PI}\left(\right) \cdot x\right)}\right) \]
    11. lower-*.f3297.7

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{1 \cdot \sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\mathsf{PI}\left(\right) \cdot x} \cdot \frac{\sin \left(tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)\right)}{\color{blue}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau}} \]
  6. Applied rewrites97.8%

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

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

Alternative 3: 71.0% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \mathsf{PI}\left(\right) \cdot x\\ t_2 := t\_1 \cdot tau\\ \frac{1}{\frac{\left(\frac{t\_2}{\sin t\_2} \cdot x\right) \cdot \mathsf{PI}\left(\right)}{t\_1}} \end{array} \end{array} \]
(FPCore (x tau)
 :precision binary32
 (let* ((t_1 (* (PI) x)) (t_2 (* t_1 tau)))
   (/ 1.0 (/ (* (* (/ t_2 (sin t_2)) x) (PI)) t_1))))
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \mathsf{PI}\left(\right) \cdot x\\
t_2 := t\_1 \cdot tau\\
\frac{1}{\frac{\left(\frac{t\_2}{\sin t\_2} \cdot x\right) \cdot \mathsf{PI}\left(\right)}{t\_1}}
\end{array}
\end{array}
Derivation
  1. Initial program 98.0%

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

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

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

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

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

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

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

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

      \[\leadsto \frac{\frac{\color{blue}{\mathsf{PI}\left(\right) \cdot x}}{x} \cdot \frac{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)}}{\mathsf{PI}\left(\right)} \]
    3. lower-PI.f3269.2

      \[\leadsto \frac{\frac{\color{blue}{\mathsf{PI}\left(\right)} \cdot x}{x} \cdot \frac{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)}}{\mathsf{PI}\left(\right)} \]
  7. Applied rewrites69.2%

    \[\leadsto \frac{\frac{\color{blue}{\mathsf{PI}\left(\right) \cdot x}}{x} \cdot \frac{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)}}{\mathsf{PI}\left(\right)} \]
  8. Applied rewrites69.0%

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

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

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

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

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

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

      \[\leadsto \frac{1}{\color{blue}{\frac{\frac{-x}{\frac{\sin \left(\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\right)}{\left(\left(-tau\right) \cdot \mathsf{PI}\left(\right)\right) \cdot x}} \cdot \mathsf{PI}\left(\right)}{\mathsf{PI}\left(\right) \cdot x}}} \]
  10. Applied rewrites69.4%

    \[\leadsto \frac{1}{\color{blue}{\frac{\left(\frac{tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)}{\sin \left(tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)\right)} \cdot x\right) \cdot \mathsf{PI}\left(\right)}{x \cdot \mathsf{PI}\left(\right)}}} \]
  11. Final simplification69.4%

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

Alternative 4: 71.0% accurate, 1.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \mathsf{PI}\left(\right) \cdot x\\ t_2 := t\_1 \cdot tau\\ \frac{t\_1 \cdot \sin t\_2}{t\_2 \cdot t\_1} \end{array} \end{array} \]
(FPCore (x tau)
 :precision binary32
 (let* ((t_1 (* (PI) x)) (t_2 (* t_1 tau))) (/ (* t_1 (sin t_2)) (* 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{t\_1 \cdot \sin t\_2}{t\_2 \cdot t\_1}
\end{array}
\end{array}
Derivation
  1. Initial program 98.0%

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

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

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

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

      \[\leadsto \frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \color{blue}{\left(\frac{1}{x \cdot \mathsf{PI}\left(\right)} \cdot \sin \left(x \cdot \mathsf{PI}\left(\right)\right)\right)} \]
    5. lower-/.f3297.7

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

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

      \[\leadsto \frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \left(\frac{1}{\color{blue}{\mathsf{PI}\left(\right) \cdot x}} \cdot \sin \left(x \cdot \mathsf{PI}\left(\right)\right)\right) \]
    8. lower-*.f3297.7

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

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

      \[\leadsto \frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \left(\frac{1}{\mathsf{PI}\left(\right) \cdot x} \cdot \sin \color{blue}{\left(\mathsf{PI}\left(\right) \cdot x\right)}\right) \]
    11. lower-*.f3297.7

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{1 \cdot \sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\mathsf{PI}\left(\right) \cdot x} \cdot \frac{\sin \left(tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)\right)}{\color{blue}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau}} \]
  6. Applied rewrites97.8%

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

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

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

      \[\leadsto \frac{\color{blue}{\left(\mathsf{PI}\left(\right) \cdot x\right)} \cdot \sin \left(\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\right)}{\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot \left(\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\right)} \]
    3. lower-PI.f3269.3

      \[\leadsto \frac{\left(\color{blue}{\mathsf{PI}\left(\right)} \cdot x\right) \cdot \sin \left(\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\right)}{\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot \left(\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\right)} \]
  9. Applied rewrites69.3%

    \[\leadsto \frac{\color{blue}{\left(\mathsf{PI}\left(\right) \cdot x\right)} \cdot \sin \left(\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\right)}{\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot \left(\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\right)} \]
  10. Final simplification69.3%

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

Alternative 5: 64.5% accurate, 1.9× speedup?

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

\\
\begin{array}{l}
t_1 := \mathsf{PI}\left(\right) \cdot x\\
\frac{1}{\frac{t\_1}{\sin t\_1}}
\end{array}
\end{array}
Derivation
  1. Initial program 98.0%

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

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

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

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

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

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

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

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

      \[\leadsto \frac{\frac{\color{blue}{\mathsf{PI}\left(\right) \cdot x}}{x} \cdot \frac{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)}}{\mathsf{PI}\left(\right)} \]
    3. lower-PI.f3269.2

      \[\leadsto \frac{\frac{\color{blue}{\mathsf{PI}\left(\right)} \cdot x}{x} \cdot \frac{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)}}{\mathsf{PI}\left(\right)} \]
  7. Applied rewrites69.2%

    \[\leadsto \frac{\frac{\color{blue}{\mathsf{PI}\left(\right) \cdot x}}{x} \cdot \frac{\sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)}}{\mathsf{PI}\left(\right)} \]
  8. Applied rewrites69.0%

    \[\leadsto \color{blue}{\frac{1}{\frac{\left(-x\right) \cdot \mathsf{PI}\left(\right)}{\frac{\sin \left(\left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\right)}{\left(\left(-tau\right) \cdot \mathsf{PI}\left(\right)\right) \cdot x} \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)}}} \]
  9. Taylor expanded in tau around 0

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

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

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

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

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

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

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

      \[\leadsto \frac{1}{\frac{\mathsf{PI}\left(\right) \cdot x}{\sin \color{blue}{\left(\mathsf{PI}\left(\right) \cdot x\right)}}} \]
    8. lower-PI.f3263.0

      \[\leadsto \frac{1}{\frac{\mathsf{PI}\left(\right) \cdot x}{\sin \left(\color{blue}{\mathsf{PI}\left(\right)} \cdot x\right)}} \]
  11. Applied rewrites63.0%

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

Alternative 6: 64.4% accurate, 2.1× speedup?

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

\\
\begin{array}{l}
t_1 := \mathsf{PI}\left(\right) \cdot x\\
\frac{\sin t\_1}{t\_1}
\end{array}
\end{array}
Derivation
  1. Initial program 98.0%

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

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

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

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

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

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

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

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

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right) \cdot \sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{tau} \cdot \frac{\frac{1}{x \cdot \mathsf{PI}\left(\right)}}{x \cdot \mathsf{PI}\left(\right)}} \]
  4. Applied rewrites97.2%

    \[\leadsto \color{blue}{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right) \cdot \sin \left(tau \cdot \left(\mathsf{PI}\left(\right) \cdot x\right)\right)}{tau} \cdot \frac{\frac{1}{\mathsf{PI}\left(\right) \cdot x}}{\mathsf{PI}\left(\right) \cdot x}} \]
  5. Taylor expanded in x around 0

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

      \[\leadsto \color{blue}{\left({\mathsf{PI}\left(\right)}^{2} \cdot {x}^{2}\right)} \cdot \frac{\frac{1}{\mathsf{PI}\left(\right) \cdot x}}{\mathsf{PI}\left(\right) \cdot x} \]
    2. unpow2N/A

      \[\leadsto \left({\mathsf{PI}\left(\right)}^{2} \cdot \color{blue}{\left(x \cdot x\right)}\right) \cdot \frac{\frac{1}{\mathsf{PI}\left(\right) \cdot x}}{\mathsf{PI}\left(\right) \cdot x} \]
    3. associate-*r*N/A

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

      \[\leadsto \left(\color{blue}{\left(x \cdot {\mathsf{PI}\left(\right)}^{2}\right)} \cdot x\right) \cdot \frac{\frac{1}{\mathsf{PI}\left(\right) \cdot x}}{\mathsf{PI}\left(\right) \cdot x} \]
    5. lower-*.f32N/A

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

      \[\leadsto \left(\color{blue}{\left({\mathsf{PI}\left(\right)}^{2} \cdot x\right)} \cdot x\right) \cdot \frac{\frac{1}{\mathsf{PI}\left(\right) \cdot x}}{\mathsf{PI}\left(\right) \cdot x} \]
    7. lower-*.f32N/A

      \[\leadsto \left(\color{blue}{\left({\mathsf{PI}\left(\right)}^{2} \cdot x\right)} \cdot x\right) \cdot \frac{\frac{1}{\mathsf{PI}\left(\right) \cdot x}}{\mathsf{PI}\left(\right) \cdot x} \]
    8. unpow2N/A

      \[\leadsto \left(\left(\color{blue}{\left(\mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right)\right)} \cdot x\right) \cdot x\right) \cdot \frac{\frac{1}{\mathsf{PI}\left(\right) \cdot x}}{\mathsf{PI}\left(\right) \cdot x} \]
    9. lower-*.f32N/A

      \[\leadsto \left(\left(\color{blue}{\left(\mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right)\right)} \cdot x\right) \cdot x\right) \cdot \frac{\frac{1}{\mathsf{PI}\left(\right) \cdot x}}{\mathsf{PI}\left(\right) \cdot x} \]
    10. lower-PI.f32N/A

      \[\leadsto \left(\left(\left(\color{blue}{\mathsf{PI}\left(\right)} \cdot \mathsf{PI}\left(\right)\right) \cdot x\right) \cdot x\right) \cdot \frac{\frac{1}{\mathsf{PI}\left(\right) \cdot x}}{\mathsf{PI}\left(\right) \cdot x} \]
    11. lower-PI.f3261.8

      \[\leadsto \left(\left(\left(\mathsf{PI}\left(\right) \cdot \color{blue}{\mathsf{PI}\left(\right)}\right) \cdot x\right) \cdot x\right) \cdot \frac{\frac{1}{\mathsf{PI}\left(\right) \cdot x}}{\mathsf{PI}\left(\right) \cdot x} \]
  7. Applied rewrites61.8%

    \[\leadsto \color{blue}{\left(\left(\left(\mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right)\right) \cdot x\right) \cdot x\right)} \cdot \frac{\frac{1}{\mathsf{PI}\left(\right) \cdot x}}{\mathsf{PI}\left(\right) \cdot x} \]
  8. Step-by-step derivation
    1. Applied rewrites61.8%

      \[\leadsto \left(\mathsf{PI}\left(\right) \cdot \color{blue}{\left(\mathsf{PI}\left(\right) \cdot \left(x \cdot x\right)\right)}\right) \cdot \frac{\frac{1}{\mathsf{PI}\left(\right) \cdot x}}{\mathsf{PI}\left(\right) \cdot x} \]
    2. Taylor expanded in tau around 0

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

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

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

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

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

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

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

        \[\leadsto \frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\color{blue}{\mathsf{PI}\left(\right) \cdot x}} \]
      8. lower-PI.f3263.0

        \[\leadsto \frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\color{blue}{\mathsf{PI}\left(\right)} \cdot x} \]
    4. Applied rewrites63.0%

      \[\leadsto \color{blue}{\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\mathsf{PI}\left(\right) \cdot x}} \]
    5. Add Preprocessing

    Alternative 7: 63.6% 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 98.0%

      \[\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{x \cdot \mathsf{PI}\left(\right)} \]
    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 2024332 
      (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)))))