Lanczos kernel

Percentage Accurate: 97.9% → 97.8%
Time: 4.1s
Alternatives: 11
Speedup: N/A×

Specification

?
\[\left(10^{-5} \leq x \land x \leq 1\right) \land \left(1 \leq tau \land tau \leq 5\right)\]
\[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(x \cdot \pi\right) \cdot tau\\ \frac{\sin t\_1}{t\_1} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \end{array} \end{array} \]
(FPCore (x tau)
 :precision binary32
 (let* ((t_1 (* (* x PI) tau)))
   (* (/ (sin t_1) t_1) (/ (sin (* x PI)) (* x PI)))))
float code(float x, float tau) {
	float t_1 = (x * ((float) M_PI)) * tau;
	return (sinf(t_1) / t_1) * (sinf((x * ((float) M_PI))) / (x * ((float) M_PI)));
}
function code(x, tau)
	t_1 = Float32(Float32(x * Float32(pi)) * tau)
	return Float32(Float32(sin(t_1) / t_1) * Float32(sin(Float32(x * Float32(pi))) / Float32(x * Float32(pi))))
end
function tmp = code(x, tau)
	t_1 = (x * single(pi)) * tau;
	tmp = (sin(t_1) / t_1) * (sin((x * single(pi))) / (x * single(pi)));
end
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \left(x \cdot \pi\right) \cdot tau\\
\frac{\sin t\_1}{t\_1} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}
\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 11 alternatives:

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

Initial Program: 97.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(x \cdot \pi\right) \cdot tau\\ \frac{\sin t\_1}{t\_1} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \end{array} \end{array} \]
(FPCore (x tau)
 :precision binary32
 (let* ((t_1 (* (* x PI) tau)))
   (* (/ (sin t_1) t_1) (/ (sin (* x PI)) (* x PI)))))
float code(float x, float tau) {
	float t_1 = (x * ((float) M_PI)) * tau;
	return (sinf(t_1) / t_1) * (sinf((x * ((float) M_PI))) / (x * ((float) M_PI)));
}
function code(x, tau)
	t_1 = Float32(Float32(x * Float32(pi)) * tau)
	return Float32(Float32(sin(t_1) / t_1) * Float32(sin(Float32(x * Float32(pi))) / Float32(x * Float32(pi))))
end
function tmp = code(x, tau)
	t_1 = (x * single(pi)) * tau;
	tmp = (sin(t_1) / t_1) * (sin((x * single(pi))) / (x * single(pi)));
end
\begin{array}{l}

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

Alternative 1: 97.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(tau \cdot x\right) \cdot \pi\\ \frac{\frac{\sin t\_1}{t\_1} \cdot \sin \left(\pi \cdot x\right)}{\pi \cdot x} \end{array} \end{array} \]
(FPCore (x tau)
 :precision binary32
 (let* ((t_1 (* (* tau x) PI)))
   (/ (* (/ (sin t_1) t_1) (sin (* PI x))) (* PI x))))
float code(float x, float tau) {
	float t_1 = (tau * x) * ((float) M_PI);
	return ((sinf(t_1) / t_1) * sinf((((float) M_PI) * x))) / (((float) M_PI) * x);
}
function code(x, tau)
	t_1 = Float32(Float32(tau * x) * Float32(pi))
	return Float32(Float32(Float32(sin(t_1) / t_1) * sin(Float32(Float32(pi) * x))) / Float32(Float32(pi) * x))
end
function tmp = code(x, tau)
	t_1 = (tau * x) * single(pi);
	tmp = ((sin(t_1) / t_1) * sin((single(pi) * x))) / (single(pi) * x);
end
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \left(tau \cdot x\right) \cdot \pi\\
\frac{\frac{\sin t\_1}{t\_1} \cdot \sin \left(\pi \cdot x\right)}{\pi \cdot x}
\end{array}
\end{array}
Derivation
  1. Initial program 97.3%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Alternative 2: 97.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(x \cdot tau\right) \cdot \pi\\ \frac{\sin t\_1 \cdot \frac{\sin \left(\pi \cdot x\right)}{t\_1}}{\pi \cdot x} \end{array} \end{array} \]
(FPCore (x tau)
 :precision binary32
 (let* ((t_1 (* (* x tau) PI)))
   (/ (* (sin t_1) (/ (sin (* PI x)) t_1)) (* PI x))))
float code(float x, float tau) {
	float t_1 = (x * tau) * ((float) M_PI);
	return (sinf(t_1) * (sinf((((float) M_PI) * x)) / t_1)) / (((float) M_PI) * x);
}
function code(x, tau)
	t_1 = Float32(Float32(x * tau) * Float32(pi))
	return Float32(Float32(sin(t_1) * Float32(sin(Float32(Float32(pi) * x)) / t_1)) / Float32(Float32(pi) * x))
end
function tmp = code(x, tau)
	t_1 = (x * tau) * single(pi);
	tmp = (sin(t_1) * (sin((single(pi) * x)) / t_1)) / (single(pi) * x);
end
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \left(x \cdot tau\right) \cdot \pi\\
\frac{\sin t\_1 \cdot \frac{\sin \left(\pi \cdot x\right)}{t\_1}}{\pi \cdot x}
\end{array}
\end{array}
Derivation
  1. Initial program 97.3%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    \[\leadsto \frac{\color{blue}{\sin \left(\left(x \cdot tau\right) \cdot \pi\right) \cdot \frac{\sin \left(\pi \cdot x\right)}{\left(x \cdot tau\right) \cdot \pi}}}{\pi \cdot x} \]
  7. Add Preprocessing

Alternative 3: 97.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(tau \cdot x\right) \cdot \pi\\ \frac{\sin \left(\pi \cdot x\right) \cdot \sin t\_1}{t\_1 \cdot \left(\pi \cdot x\right)} \end{array} \end{array} \]
(FPCore (x tau)
 :precision binary32
 (let* ((t_1 (* (* tau x) PI)))
   (/ (* (sin (* PI x)) (sin t_1)) (* t_1 (* PI x)))))
float code(float x, float tau) {
	float t_1 = (tau * x) * ((float) M_PI);
	return (sinf((((float) M_PI) * x)) * sinf(t_1)) / (t_1 * (((float) M_PI) * x));
}
function code(x, tau)
	t_1 = Float32(Float32(tau * x) * Float32(pi))
	return Float32(Float32(sin(Float32(Float32(pi) * x)) * sin(t_1)) / Float32(t_1 * Float32(Float32(pi) * x)))
end
function tmp = code(x, tau)
	t_1 = (tau * x) * single(pi);
	tmp = (sin((single(pi) * x)) * sin(t_1)) / (t_1 * (single(pi) * x));
end
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \left(tau \cdot x\right) \cdot \pi\\
\frac{\sin \left(\pi \cdot x\right) \cdot \sin t\_1}{t\_1 \cdot \left(\pi \cdot x\right)}
\end{array}
\end{array}
Derivation
  1. Initial program 97.3%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Alternative 4: 97.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(tau \cdot x\right) \cdot \pi\\ \sin t\_1 \cdot \frac{\sin \left(\pi \cdot x\right)}{\left(t\_1 \cdot \pi\right) \cdot x} \end{array} \end{array} \]
(FPCore (x tau)
 :precision binary32
 (let* ((t_1 (* (* tau x) PI)))
   (* (sin t_1) (/ (sin (* PI x)) (* (* t_1 PI) x)))))
float code(float x, float tau) {
	float t_1 = (tau * x) * ((float) M_PI);
	return sinf(t_1) * (sinf((((float) M_PI) * x)) / ((t_1 * ((float) M_PI)) * x));
}
function code(x, tau)
	t_1 = Float32(Float32(tau * x) * Float32(pi))
	return Float32(sin(t_1) * Float32(sin(Float32(Float32(pi) * x)) / Float32(Float32(t_1 * Float32(pi)) * x)))
end
function tmp = code(x, tau)
	t_1 = (tau * x) * single(pi);
	tmp = sin(t_1) * (sin((single(pi) * x)) / ((t_1 * single(pi)) * x));
end
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \left(tau \cdot x\right) \cdot \pi\\
\sin t\_1 \cdot \frac{\sin \left(\pi \cdot x\right)}{\left(t\_1 \cdot \pi\right) \cdot x}
\end{array}
\end{array}
Derivation
  1. Initial program 97.3%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{\sin \left(\left(x \cdot tau\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\left(\left(x \cdot tau\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \color{blue}{\left(\mathsf{PI}\left(\right) \cdot x\right)}} \]
  8. Applied rewrites96.8%

    \[\leadsto \color{blue}{\sin \left(\left(tau \cdot x\right) \cdot \pi\right) \cdot \frac{\sin \left(\pi \cdot x\right)}{\left(\left(\left(tau \cdot x\right) \cdot \pi\right) \cdot \pi\right) \cdot x}} \]
  9. Add Preprocessing

Alternative 5: 85.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(x \cdot \pi\right) \cdot tau\\ \frac{\sin t\_1}{t\_1} \cdot \mathsf{fma}\left({\left(\pi \cdot x\right)}^{2}, -0.16666666666666666, 1\right) \end{array} \end{array} \]
(FPCore (x tau)
 :precision binary32
 (let* ((t_1 (* (* x PI) tau)))
   (* (/ (sin t_1) t_1) (fma (pow (* PI x) 2.0) -0.16666666666666666 1.0))))
float code(float x, float tau) {
	float t_1 = (x * ((float) M_PI)) * tau;
	return (sinf(t_1) / t_1) * fmaf(powf((((float) M_PI) * x), 2.0f), -0.16666666666666666f, 1.0f);
}
function code(x, tau)
	t_1 = Float32(Float32(x * Float32(pi)) * tau)
	return Float32(Float32(sin(t_1) / t_1) * fma((Float32(Float32(pi) * x) ^ Float32(2.0)), Float32(-0.16666666666666666), Float32(1.0)))
end
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \left(x \cdot \pi\right) \cdot tau\\
\frac{\sin t\_1}{t\_1} \cdot \mathsf{fma}\left({\left(\pi \cdot x\right)}^{2}, -0.16666666666666666, 1\right)
\end{array}
\end{array}
Derivation
  1. Initial program 97.3%

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

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

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

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

      \[\leadsto \frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \mathsf{fma}\left({x}^{2} \cdot {\mathsf{PI}\left(\right)}^{2}, \color{blue}{\frac{-1}{6}}, 1\right) \]
    4. pow-prod-downN/A

      \[\leadsto \frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \mathsf{fma}\left({\left(x \cdot \mathsf{PI}\left(\right)\right)}^{2}, \frac{-1}{6}, 1\right) \]
    5. lower-pow.f32N/A

      \[\leadsto \frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \mathsf{fma}\left({\left(x \cdot \mathsf{PI}\left(\right)\right)}^{2}, \frac{-1}{6}, 1\right) \]
    6. *-commutativeN/A

      \[\leadsto \frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \mathsf{fma}\left({\left(\mathsf{PI}\left(\right) \cdot x\right)}^{2}, \frac{-1}{6}, 1\right) \]
    7. lower-*.f32N/A

      \[\leadsto \frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \mathsf{fma}\left({\left(\mathsf{PI}\left(\right) \cdot x\right)}^{2}, \frac{-1}{6}, 1\right) \]
    8. lift-PI.f3283.6

      \[\leadsto \frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \mathsf{fma}\left({\left(\pi \cdot x\right)}^{2}, -0.16666666666666666, 1\right) \]
  5. Applied rewrites83.6%

    \[\leadsto \frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \color{blue}{\mathsf{fma}\left({\left(\pi \cdot x\right)}^{2}, -0.16666666666666666, 1\right)} \]
  6. Add Preprocessing

Alternative 6: 79.9% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left({\left(x \cdot \left(\pi \cdot tau\right)\right)}^{2}, -0.16666666666666666, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \end{array} \]
(FPCore (x tau)
 :precision binary32
 (*
  (fma (pow (* x (* PI tau)) 2.0) -0.16666666666666666 1.0)
  (/ (sin (* x PI)) (* x PI))))
float code(float x, float tau) {
	return fmaf(powf((x * (((float) M_PI) * tau)), 2.0f), -0.16666666666666666f, 1.0f) * (sinf((x * ((float) M_PI))) / (x * ((float) M_PI)));
}
function code(x, tau)
	return Float32(fma((Float32(x * Float32(Float32(pi) * tau)) ^ Float32(2.0)), Float32(-0.16666666666666666), Float32(1.0)) * Float32(sin(Float32(x * Float32(pi))) / Float32(x * Float32(pi))))
end
\begin{array}{l}

\\
\mathsf{fma}\left({\left(x \cdot \left(\pi \cdot tau\right)\right)}^{2}, -0.16666666666666666, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}
\end{array}
Derivation
  1. Initial program 97.3%

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

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

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

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

      \[\leadsto \mathsf{fma}\left({tau}^{2} \cdot \left({x}^{2} \cdot {\mathsf{PI}\left(\right)}^{2}\right), \color{blue}{\frac{-1}{6}}, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  5. Applied rewrites77.3%

    \[\leadsto \color{blue}{\mathsf{fma}\left({\left(\left(tau \cdot x\right) \cdot \pi\right)}^{2}, -0.16666666666666666, 1\right)} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  6. Step-by-step derivation
    1. lift-*.f32N/A

      \[\leadsto \mathsf{fma}\left({\left(\left(tau \cdot x\right) \cdot \pi\right)}^{2}, \frac{-1}{6}, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    2. lift-PI.f32N/A

      \[\leadsto \mathsf{fma}\left({\left(\left(tau \cdot x\right) \cdot \mathsf{PI}\left(\right)\right)}^{2}, \frac{-1}{6}, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    3. lift-*.f32N/A

      \[\leadsto \mathsf{fma}\left({\left(\left(tau \cdot x\right) \cdot \mathsf{PI}\left(\right)\right)}^{2}, \frac{-1}{6}, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    4. associate-*r*N/A

      \[\leadsto \mathsf{fma}\left({\left(tau \cdot \left(x \cdot \mathsf{PI}\left(\right)\right)\right)}^{2}, \frac{-1}{6}, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    5. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left({\left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}^{2}, \frac{-1}{6}, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    6. associate-*l*N/A

      \[\leadsto \mathsf{fma}\left({\left(x \cdot \left(\mathsf{PI}\left(\right) \cdot tau\right)\right)}^{2}, \frac{-1}{6}, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    7. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left({\left(x \cdot \left(tau \cdot \mathsf{PI}\left(\right)\right)\right)}^{2}, \frac{-1}{6}, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    8. lower-*.f32N/A

      \[\leadsto \mathsf{fma}\left({\left(x \cdot \left(tau \cdot \mathsf{PI}\left(\right)\right)\right)}^{2}, \frac{-1}{6}, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    9. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left({\left(x \cdot \left(\mathsf{PI}\left(\right) \cdot tau\right)\right)}^{2}, \frac{-1}{6}, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    10. lower-*.f32N/A

      \[\leadsto \mathsf{fma}\left({\left(x \cdot \left(\mathsf{PI}\left(\right) \cdot tau\right)\right)}^{2}, \frac{-1}{6}, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    11. lift-PI.f3277.3

      \[\leadsto \mathsf{fma}\left({\left(x \cdot \left(\pi \cdot tau\right)\right)}^{2}, -0.16666666666666666, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  7. Applied rewrites77.3%

    \[\leadsto \mathsf{fma}\left({\left(x \cdot \left(\pi \cdot tau\right)\right)}^{2}, -0.16666666666666666, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  8. Add Preprocessing

Alternative 7: 79.9% accurate, 1.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(x \cdot tau\right) \cdot \pi\\ \mathsf{fma}\left(t\_1 \cdot t\_1, -0.16666666666666666, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \end{array} \end{array} \]
(FPCore (x tau)
 :precision binary32
 (let* ((t_1 (* (* x tau) PI)))
   (* (fma (* t_1 t_1) -0.16666666666666666 1.0) (/ (sin (* x PI)) (* x PI)))))
float code(float x, float tau) {
	float t_1 = (x * tau) * ((float) M_PI);
	return fmaf((t_1 * t_1), -0.16666666666666666f, 1.0f) * (sinf((x * ((float) M_PI))) / (x * ((float) M_PI)));
}
function code(x, tau)
	t_1 = Float32(Float32(x * tau) * Float32(pi))
	return Float32(fma(Float32(t_1 * t_1), Float32(-0.16666666666666666), Float32(1.0)) * Float32(sin(Float32(x * Float32(pi))) / Float32(x * Float32(pi))))
end
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \left(x \cdot tau\right) \cdot \pi\\
\mathsf{fma}\left(t\_1 \cdot t\_1, -0.16666666666666666, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}
\end{array}
\end{array}
Derivation
  1. Initial program 97.3%

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

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

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

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

      \[\leadsto \mathsf{fma}\left({tau}^{2} \cdot \left({x}^{2} \cdot {\mathsf{PI}\left(\right)}^{2}\right), \color{blue}{\frac{-1}{6}}, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  5. Applied rewrites77.3%

    \[\leadsto \color{blue}{\mathsf{fma}\left({\left(\left(tau \cdot x\right) \cdot \pi\right)}^{2}, -0.16666666666666666, 1\right)} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  6. Step-by-step derivation
    1. lift-pow.f32N/A

      \[\leadsto \mathsf{fma}\left({\left(\left(tau \cdot x\right) \cdot \pi\right)}^{2}, \frac{-1}{6}, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    2. unpow2N/A

      \[\leadsto \mathsf{fma}\left(\left(\left(tau \cdot x\right) \cdot \pi\right) \cdot \left(\left(tau \cdot x\right) \cdot \pi\right), \frac{-1}{6}, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    3. lower-*.f3277.3

      \[\leadsto \mathsf{fma}\left(\left(\left(tau \cdot x\right) \cdot \pi\right) \cdot \left(\left(tau \cdot x\right) \cdot \pi\right), -0.16666666666666666, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    4. lift-*.f32N/A

      \[\leadsto \mathsf{fma}\left(\left(\left(tau \cdot x\right) \cdot \pi\right) \cdot \left(\left(tau \cdot x\right) \cdot \pi\right), \frac{-1}{6}, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    5. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left(\left(\left(x \cdot tau\right) \cdot \pi\right) \cdot \left(\left(tau \cdot x\right) \cdot \pi\right), \frac{-1}{6}, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    6. lower-*.f3277.3

      \[\leadsto \mathsf{fma}\left(\left(\left(x \cdot tau\right) \cdot \pi\right) \cdot \left(\left(tau \cdot x\right) \cdot \pi\right), -0.16666666666666666, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    7. lift-*.f32N/A

      \[\leadsto \mathsf{fma}\left(\left(\left(x \cdot tau\right) \cdot \pi\right) \cdot \left(\left(tau \cdot x\right) \cdot \pi\right), \frac{-1}{6}, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    8. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left(\left(\left(x \cdot tau\right) \cdot \pi\right) \cdot \left(\left(x \cdot tau\right) \cdot \pi\right), \frac{-1}{6}, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    9. lower-*.f3277.3

      \[\leadsto \mathsf{fma}\left(\left(\left(x \cdot tau\right) \cdot \pi\right) \cdot \left(\left(x \cdot tau\right) \cdot \pi\right), -0.16666666666666666, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  7. Applied rewrites77.3%

    \[\leadsto \mathsf{fma}\left(\left(\left(x \cdot tau\right) \cdot \pi\right) \cdot \left(\left(x \cdot tau\right) \cdot \pi\right), -0.16666666666666666, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  8. Add Preprocessing

Alternative 8: 79.2% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(-0.16666666666666666 \cdot \left({\left(\pi \cdot tau\right)}^{2} + \pi \cdot \pi\right), x \cdot x, 1\right) \end{array} \]
(FPCore (x tau)
 :precision binary32
 (fma (* -0.16666666666666666 (+ (pow (* PI tau) 2.0) (* PI PI))) (* x x) 1.0))
float code(float x, float tau) {
	return fmaf((-0.16666666666666666f * (powf((((float) M_PI) * tau), 2.0f) + (((float) M_PI) * ((float) M_PI)))), (x * x), 1.0f);
}
function code(x, tau)
	return fma(Float32(Float32(-0.16666666666666666) * Float32((Float32(Float32(pi) * tau) ^ Float32(2.0)) + Float32(Float32(pi) * Float32(pi)))), Float32(x * x), Float32(1.0))
end
\begin{array}{l}

\\
\mathsf{fma}\left(-0.16666666666666666 \cdot \left({\left(\pi \cdot tau\right)}^{2} + \pi \cdot \pi\right), x \cdot x, 1\right)
\end{array}
Derivation
  1. Initial program 97.3%

    \[\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  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

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

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

      \[\leadsto \mathsf{fma}\left(\frac{-1}{6} \cdot \left({tau}^{2} \cdot {\mathsf{PI}\left(\right)}^{2}\right) + \frac{-1}{6} \cdot {\mathsf{PI}\left(\right)}^{2}, \color{blue}{{x}^{2}}, 1\right) \]
  5. Applied rewrites76.6%

    \[\leadsto \color{blue}{\mathsf{fma}\left(-0.16666666666666666 \cdot \left({\left(\pi \cdot tau\right)}^{2} + \pi \cdot \pi\right), x \cdot x, 1\right)} \]
  6. Add Preprocessing

Alternative 9: 70.2% accurate, 2.1× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left({\left(\left(tau \cdot x\right) \cdot \pi\right)}^{2}, -0.16666666666666666, 1\right) \cdot 1 \end{array} \]
(FPCore (x tau)
 :precision binary32
 (* (fma (pow (* (* tau x) PI) 2.0) -0.16666666666666666 1.0) 1.0))
float code(float x, float tau) {
	return fmaf(powf(((tau * x) * ((float) M_PI)), 2.0f), -0.16666666666666666f, 1.0f) * 1.0f;
}
function code(x, tau)
	return Float32(fma((Float32(Float32(tau * x) * Float32(pi)) ^ Float32(2.0)), Float32(-0.16666666666666666), Float32(1.0)) * Float32(1.0))
end
\begin{array}{l}

\\
\mathsf{fma}\left({\left(\left(tau \cdot x\right) \cdot \pi\right)}^{2}, -0.16666666666666666, 1\right) \cdot 1
\end{array}
Derivation
  1. Initial program 97.3%

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

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

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

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

      \[\leadsto \mathsf{fma}\left({tau}^{2} \cdot \left({x}^{2} \cdot {\mathsf{PI}\left(\right)}^{2}\right), \color{blue}{\frac{-1}{6}}, 1\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  5. Applied rewrites77.3%

    \[\leadsto \color{blue}{\mathsf{fma}\left({\left(\left(tau \cdot x\right) \cdot \pi\right)}^{2}, -0.16666666666666666, 1\right)} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  6. Taylor expanded in x around 0

    \[\leadsto \mathsf{fma}\left({\left(\left(tau \cdot x\right) \cdot \pi\right)}^{2}, \frac{-1}{6}, 1\right) \cdot \color{blue}{1} \]
  7. Step-by-step derivation
    1. Applied rewrites66.9%

      \[\leadsto \mathsf{fma}\left({\left(\left(tau \cdot x\right) \cdot \pi\right)}^{2}, -0.16666666666666666, 1\right) \cdot \color{blue}{1} \]
    2. Add Preprocessing

    Alternative 10: 64.6% accurate, 2.1× speedup?

    \[\begin{array}{l} \\ \frac{\sin \left(\pi \cdot x\right)}{\pi \cdot x} \end{array} \]
    (FPCore (x tau) :precision binary32 (/ (sin (* PI x)) (* PI x)))
    float code(float x, float tau) {
    	return sinf((((float) M_PI) * x)) / (((float) M_PI) * x);
    }
    
    function code(x, tau)
    	return Float32(sin(Float32(Float32(pi) * x)) / Float32(Float32(pi) * x))
    end
    
    function tmp = code(x, tau)
    	tmp = sin((single(pi) * x)) / (single(pi) * x);
    end
    
    \begin{array}{l}
    
    \\
    \frac{\sin \left(\pi \cdot x\right)}{\pi \cdot x}
    \end{array}
    
    Derivation
    1. Initial program 97.3%

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\sin \left(\pi \cdot x\right)}{\mathsf{PI}\left(\right) \cdot \color{blue}{x}} \]
      8. lift-PI.f3261.9

        \[\leadsto \frac{\sin \left(\pi \cdot x\right)}{\pi \cdot x} \]
    5. Applied rewrites61.9%

      \[\leadsto \color{blue}{\frac{\sin \left(\pi \cdot x\right)}{\pi \cdot x}} \]
    6. Add Preprocessing

    Alternative 11: 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;
    }
    
    module fmin_fmax_functions
        implicit none
        private
        public fmax
        public fmin
    
        interface fmax
            module procedure fmax88
            module procedure fmax44
            module procedure fmax84
            module procedure fmax48
        end interface
        interface fmin
            module procedure fmin88
            module procedure fmin44
            module procedure fmin84
            module procedure fmin48
        end interface
    contains
        real(8) function fmax88(x, y) result (res)
            real(8), intent (in) :: x
            real(8), intent (in) :: y
            res = merge(y, merge(x, max(x, y), y /= y), x /= x)
        end function
        real(4) function fmax44(x, y) result (res)
            real(4), intent (in) :: x
            real(4), intent (in) :: y
            res = merge(y, merge(x, max(x, y), y /= y), x /= x)
        end function
        real(8) function fmax84(x, y) result(res)
            real(8), intent (in) :: x
            real(4), intent (in) :: y
            res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
        end function
        real(8) function fmax48(x, y) result(res)
            real(4), intent (in) :: x
            real(8), intent (in) :: y
            res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
        end function
        real(8) function fmin88(x, y) result (res)
            real(8), intent (in) :: x
            real(8), intent (in) :: y
            res = merge(y, merge(x, min(x, y), y /= y), x /= x)
        end function
        real(4) function fmin44(x, y) result (res)
            real(4), intent (in) :: x
            real(4), intent (in) :: y
            res = merge(y, merge(x, min(x, y), y /= y), x /= x)
        end function
        real(8) function fmin84(x, y) result(res)
            real(8), intent (in) :: x
            real(4), intent (in) :: y
            res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
        end function
        real(8) function fmin48(x, y) result(res)
            real(4), intent (in) :: x
            real(8), intent (in) :: y
            res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
        end function
    end module
    
    real(4) function code(x, tau)
    use fmin_fmax_functions
        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 97.3%

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

      \[\leadsto \color{blue}{1} \]
    4. Step-by-step derivation
      1. Applied rewrites61.1%

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

      Reproduce

      ?
      herbie shell --seed 2025064 
      (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))))