Lanczos kernel

Percentage Accurate: 97.9% → 97.9%
Time: 24.9s
Alternatives: 19
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 19 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: 97.9% accurate, 1.0× speedup?

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

\\
\begin{array}{l}
t_1 := \pi \cdot \left(x \cdot tau\right)\\
\frac{\sin t_1}{t_1} \cdot \frac{\sin \left(\pi \cdot x\right)}{\pi \cdot x}
\end{array}
\end{array}
Derivation
  1. Initial program 97.9%

    \[\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  2. Step-by-step derivation
    1. *-commutative97.9%

      \[\leadsto \frac{\sin \left(\color{blue}{\left(\pi \cdot x\right)} \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    2. associate-*l*97.4%

      \[\leadsto \frac{\sin \color{blue}{\left(\pi \cdot \left(x \cdot tau\right)\right)}}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    3. *-commutative97.4%

      \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\color{blue}{\left(\pi \cdot x\right)} \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    4. associate-*l*98.0%

      \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\color{blue}{\pi \cdot \left(x \cdot tau\right)}} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  3. Simplified98.0%

    \[\leadsto \color{blue}{\frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\pi \cdot \left(x \cdot tau\right)} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}} \]
  4. Final simplification98.0%

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

Alternative 2: 97.6% accurate, 1.0× speedup?

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

\\
\begin{array}{l}
t_1 := x \cdot \left(\pi \cdot tau\right)\\
\frac{\sin t_1}{\pi \cdot x} \cdot \frac{\sin \left(\pi \cdot x\right)}{t_1}
\end{array}
\end{array}
Derivation
  1. Initial program 97.9%

    \[\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  2. Step-by-step derivation
    1. associate-*l/97.9%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{\left(x \cdot \pi\right) \cdot tau}} \]
    2. times-frac97.4%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau}} \]
    3. associate-*l*97.0%

      \[\leadsto \frac{\sin \color{blue}{\left(x \cdot \left(\pi \cdot tau\right)\right)}}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau} \]
    4. associate-/l/97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{tau \cdot \left(x \cdot \pi\right)}} \]
    5. *-commutative97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{\left(x \cdot \pi\right) \cdot tau}} \]
    6. associate-*l*97.6%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{x \cdot \left(\pi \cdot tau\right)}} \]
  3. Simplified97.6%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}} \]
  4. Final simplification97.6%

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

Alternative 3: 97.1% accurate, 1.0× speedup?

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

\\
\frac{\sin \left(\pi \cdot x\right)}{tau} \cdot \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{{\left(\pi \cdot x\right)}^{2}}
\end{array}
Derivation
  1. Initial program 97.9%

    \[\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  2. Step-by-step derivation
    1. associate-*l/97.9%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{\left(x \cdot \pi\right) \cdot tau}} \]
    2. times-frac97.4%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau}} \]
    3. associate-*l*97.0%

      \[\leadsto \frac{\sin \color{blue}{\left(x \cdot \left(\pi \cdot tau\right)\right)}}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau} \]
    4. associate-/l/97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{tau \cdot \left(x \cdot \pi\right)}} \]
    5. *-commutative97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{\left(x \cdot \pi\right) \cdot tau}} \]
    6. associate-*l*97.6%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{x \cdot \left(\pi \cdot tau\right)}} \]
  3. Simplified97.6%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}} \]
  4. Step-by-step derivation
    1. *-commutative97.6%

      \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)} \cdot \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi}} \]
    2. clear-num97.7%

      \[\leadsto \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)} \cdot \color{blue}{\frac{1}{\frac{x \cdot \pi}{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}}} \]
    3. un-div-inv97.8%

      \[\leadsto \color{blue}{\frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}}{\frac{x \cdot \pi}{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}}} \]
    4. associate-/l*97.2%

      \[\leadsto \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}}{\color{blue}{\frac{x}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\pi}}}} \]
  5. Applied egg-rr97.2%

    \[\leadsto \color{blue}{\frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}}{\frac{x}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\pi}}}} \]
  6. Taylor expanded in x around inf 96.9%

    \[\leadsto \color{blue}{\frac{\sin \left(tau \cdot \left(x \cdot \pi\right)\right) \cdot \sin \left(x \cdot \pi\right)}{tau \cdot \left({x}^{2} \cdot {\pi}^{2}\right)}} \]
  7. Step-by-step derivation
    1. *-commutative96.9%

      \[\leadsto \frac{\color{blue}{\sin \left(x \cdot \pi\right) \cdot \sin \left(tau \cdot \left(x \cdot \pi\right)\right)}}{tau \cdot \left({x}^{2} \cdot {\pi}^{2}\right)} \]
    2. *-commutative96.9%

      \[\leadsto \frac{\sin \left(x \cdot \pi\right) \cdot \sin \color{blue}{\left(\left(x \cdot \pi\right) \cdot tau\right)}}{tau \cdot \left({x}^{2} \cdot {\pi}^{2}\right)} \]
    3. associate-*r*97.1%

      \[\leadsto \frac{\sin \left(x \cdot \pi\right) \cdot \sin \color{blue}{\left(x \cdot \left(\pi \cdot tau\right)\right)}}{tau \cdot \left({x}^{2} \cdot {\pi}^{2}\right)} \]
    4. unpow297.1%

      \[\leadsto \frac{\sin \left(x \cdot \pi\right) \cdot \sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{tau \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot {\pi}^{2}\right)} \]
    5. unpow297.1%

      \[\leadsto \frac{\sin \left(x \cdot \pi\right) \cdot \sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{tau \cdot \left(\left(x \cdot x\right) \cdot \color{blue}{\left(\pi \cdot \pi\right)}\right)} \]
    6. swap-sqr97.4%

      \[\leadsto \frac{\sin \left(x \cdot \pi\right) \cdot \sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{tau \cdot \color{blue}{\left(\left(x \cdot \pi\right) \cdot \left(x \cdot \pi\right)\right)}} \]
    7. unpow297.4%

      \[\leadsto \frac{\sin \left(x \cdot \pi\right) \cdot \sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{tau \cdot \color{blue}{{\left(x \cdot \pi\right)}^{2}}} \]
    8. times-frac97.3%

      \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{tau} \cdot \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{{\left(x \cdot \pi\right)}^{2}}} \]
  8. Simplified97.3%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{tau} \cdot \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{{\left(x \cdot \pi\right)}^{2}}} \]
  9. Final simplification97.3%

    \[\leadsto \frac{\sin \left(\pi \cdot x\right)}{tau} \cdot \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{{\left(\pi \cdot x\right)}^{2}} \]

Alternative 4: 97.1% accurate, 1.0× speedup?

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

\\
\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{tau} \cdot \frac{\sin \left(\pi \cdot x\right)}{{\left(\pi \cdot x\right)}^{2}}
\end{array}
Derivation
  1. Initial program 97.9%

    \[\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  2. Step-by-step derivation
    1. associate-*l/97.9%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{\left(x \cdot \pi\right) \cdot tau}} \]
    2. times-frac97.4%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau}} \]
    3. associate-*l*97.0%

      \[\leadsto \frac{\sin \color{blue}{\left(x \cdot \left(\pi \cdot tau\right)\right)}}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau} \]
    4. associate-/l/97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{tau \cdot \left(x \cdot \pi\right)}} \]
    5. *-commutative97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{\left(x \cdot \pi\right) \cdot tau}} \]
    6. associate-*l*97.6%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{x \cdot \left(\pi \cdot tau\right)}} \]
  3. Simplified97.6%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}} \]
  4. Step-by-step derivation
    1. add-log-exp97.0%

      \[\leadsto \color{blue}{\log \left(e^{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}}\right)} \]
    2. frac-times97.1%

      \[\leadsto \log \left(e^{\color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right) \cdot \sin \left(x \cdot \pi\right)}{\left(x \cdot \pi\right) \cdot \left(x \cdot \left(\pi \cdot tau\right)\right)}}}\right) \]
    3. associate-/l*97.0%

      \[\leadsto \log \left(e^{\color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\frac{\left(x \cdot \pi\right) \cdot \left(x \cdot \left(\pi \cdot tau\right)\right)}{\sin \left(x \cdot \pi\right)}}}}\right) \]
    4. associate-*r*96.7%

      \[\leadsto \log \left(e^{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\frac{\left(x \cdot \pi\right) \cdot \color{blue}{\left(\left(x \cdot \pi\right) \cdot tau\right)}}{\sin \left(x \cdot \pi\right)}}}\right) \]
    5. associate-*r*96.7%

      \[\leadsto \log \left(e^{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\frac{\color{blue}{\left(\left(x \cdot \pi\right) \cdot \left(x \cdot \pi\right)\right) \cdot tau}}{\sin \left(x \cdot \pi\right)}}}\right) \]
    6. pow296.7%

      \[\leadsto \log \left(e^{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\frac{\color{blue}{{\left(x \cdot \pi\right)}^{2}} \cdot tau}{\sin \left(x \cdot \pi\right)}}}\right) \]
  5. Applied egg-rr96.7%

    \[\leadsto \color{blue}{\log \left(e^{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\frac{{\left(x \cdot \pi\right)}^{2} \cdot tau}{\sin \left(x \cdot \pi\right)}}}\right)} \]
  6. Step-by-step derivation
    1. add-log-exp97.1%

      \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\frac{{\left(x \cdot \pi\right)}^{2} \cdot tau}{\sin \left(x \cdot \pi\right)}}} \]
    2. associate-/r/97.2%

      \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{{\left(x \cdot \pi\right)}^{2} \cdot tau} \cdot \sin \left(x \cdot \pi\right)} \]
    3. *-commutative97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\color{blue}{tau \cdot {\left(x \cdot \pi\right)}^{2}}} \cdot \sin \left(x \cdot \pi\right) \]
    4. associate-*l/97.4%

      \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right) \cdot \sin \left(x \cdot \pi\right)}{tau \cdot {\left(x \cdot \pi\right)}^{2}}} \]
    5. times-frac97.3%

      \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{{\left(x \cdot \pi\right)}^{2}}} \]
  7. Applied egg-rr97.3%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{{\left(x \cdot \pi\right)}^{2}}} \]
  8. Final simplification97.3%

    \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{tau} \cdot \frac{\sin \left(\pi \cdot x\right)}{{\left(\pi \cdot x\right)}^{2}} \]

Alternative 5: 97.4% accurate, 1.0× speedup?

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

\\
\sin \left(\pi \cdot x\right) \cdot \frac{\frac{\sin \left(tau \cdot \left(\pi \cdot x\right)\right)}{{\left(\pi \cdot x\right)}^{2}}}{tau}
\end{array}
Derivation
  1. Initial program 97.9%

    \[\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  2. Step-by-step derivation
    1. associate-*l/97.9%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{\left(x \cdot \pi\right) \cdot tau}} \]
    2. times-frac97.4%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau}} \]
    3. associate-*l*97.0%

      \[\leadsto \frac{\sin \color{blue}{\left(x \cdot \left(\pi \cdot tau\right)\right)}}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau} \]
    4. associate-/l/97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{tau \cdot \left(x \cdot \pi\right)}} \]
    5. *-commutative97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{\left(x \cdot \pi\right) \cdot tau}} \]
    6. associate-*l*97.6%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{x \cdot \left(\pi \cdot tau\right)}} \]
  3. Simplified97.6%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}} \]
  4. Step-by-step derivation
    1. add-cube-cbrt97.1%

      \[\leadsto \color{blue}{\left(\sqrt[3]{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}} \cdot \sqrt[3]{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}}\right) \cdot \sqrt[3]{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}}} \]
    2. pow397.2%

      \[\leadsto \color{blue}{{\left(\sqrt[3]{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}}\right)}^{3}} \]
  5. Applied egg-rr96.9%

    \[\leadsto \color{blue}{{\left(\sqrt[3]{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\frac{{\left(x \cdot \pi\right)}^{2} \cdot tau}{\sin \left(x \cdot \pi\right)}}}\right)}^{3}} \]
  6. Step-by-step derivation
    1. rem-cube-cbrt97.1%

      \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\frac{{\left(x \cdot \pi\right)}^{2} \cdot tau}{\sin \left(x \cdot \pi\right)}}} \]
    2. associate-/r/97.2%

      \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{{\left(x \cdot \pi\right)}^{2} \cdot tau} \cdot \sin \left(x \cdot \pi\right)} \]
    3. *-commutative97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\color{blue}{tau \cdot {\left(x \cdot \pi\right)}^{2}}} \cdot \sin \left(x \cdot \pi\right) \]
  7. Applied egg-rr97.2%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{tau \cdot {\left(x \cdot \pi\right)}^{2}} \cdot \sin \left(x \cdot \pi\right)} \]
  8. Taylor expanded in x around inf 97.0%

    \[\leadsto \color{blue}{\frac{\sin \left(tau \cdot \left(x \cdot \pi\right)\right)}{tau \cdot \left({x}^{2} \cdot {\pi}^{2}\right)}} \cdot \sin \left(x \cdot \pi\right) \]
  9. Step-by-step derivation
    1. *-commutative97.0%

      \[\leadsto \frac{\sin \color{blue}{\left(\left(x \cdot \pi\right) \cdot tau\right)}}{tau \cdot \left({x}^{2} \cdot {\pi}^{2}\right)} \cdot \sin \left(x \cdot \pi\right) \]
    2. associate-*r*97.2%

      \[\leadsto \frac{\sin \color{blue}{\left(x \cdot \left(\pi \cdot tau\right)\right)}}{tau \cdot \left({x}^{2} \cdot {\pi}^{2}\right)} \cdot \sin \left(x \cdot \pi\right) \]
    3. *-commutative97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\color{blue}{\left({x}^{2} \cdot {\pi}^{2}\right) \cdot tau}} \cdot \sin \left(x \cdot \pi\right) \]
    4. unpow297.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\left(\color{blue}{\left(x \cdot x\right)} \cdot {\pi}^{2}\right) \cdot tau} \cdot \sin \left(x \cdot \pi\right) \]
    5. unpow297.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\left(\left(x \cdot x\right) \cdot \color{blue}{\left(\pi \cdot \pi\right)}\right) \cdot tau} \cdot \sin \left(x \cdot \pi\right) \]
    6. swap-sqr97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\color{blue}{\left(\left(x \cdot \pi\right) \cdot \left(x \cdot \pi\right)\right)} \cdot tau} \cdot \sin \left(x \cdot \pi\right) \]
    7. unpow297.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\color{blue}{{\left(x \cdot \pi\right)}^{2}} \cdot tau} \cdot \sin \left(x \cdot \pi\right) \]
    8. associate-/r*97.2%

      \[\leadsto \color{blue}{\frac{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{{\left(x \cdot \pi\right)}^{2}}}{tau}} \cdot \sin \left(x \cdot \pi\right) \]
    9. associate-*r*97.3%

      \[\leadsto \frac{\frac{\sin \color{blue}{\left(\left(x \cdot \pi\right) \cdot tau\right)}}{{\left(x \cdot \pi\right)}^{2}}}{tau} \cdot \sin \left(x \cdot \pi\right) \]
    10. *-commutative97.3%

      \[\leadsto \frac{\frac{\sin \color{blue}{\left(tau \cdot \left(x \cdot \pi\right)\right)}}{{\left(x \cdot \pi\right)}^{2}}}{tau} \cdot \sin \left(x \cdot \pi\right) \]
  10. Simplified97.3%

    \[\leadsto \color{blue}{\frac{\frac{\sin \left(tau \cdot \left(x \cdot \pi\right)\right)}{{\left(x \cdot \pi\right)}^{2}}}{tau}} \cdot \sin \left(x \cdot \pi\right) \]
  11. Final simplification97.3%

    \[\leadsto \sin \left(\pi \cdot x\right) \cdot \frac{\frac{\sin \left(tau \cdot \left(\pi \cdot x\right)\right)}{{\left(\pi \cdot x\right)}^{2}}}{tau} \]

Alternative 6: 97.1% accurate, 1.0× speedup?

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

\\
\frac{\sin \left(\pi \cdot x\right) \cdot \sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{tau \cdot {\left(\pi \cdot x\right)}^{2}}
\end{array}
Derivation
  1. Initial program 97.9%

    \[\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  2. Step-by-step derivation
    1. associate-*l/97.9%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{\left(x \cdot \pi\right) \cdot tau}} \]
    2. times-frac97.4%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau}} \]
    3. associate-*l*97.0%

      \[\leadsto \frac{\sin \color{blue}{\left(x \cdot \left(\pi \cdot tau\right)\right)}}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau} \]
    4. associate-/l/97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{tau \cdot \left(x \cdot \pi\right)}} \]
    5. *-commutative97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{\left(x \cdot \pi\right) \cdot tau}} \]
    6. associate-*l*97.6%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{x \cdot \left(\pi \cdot tau\right)}} \]
  3. Simplified97.6%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}} \]
  4. Step-by-step derivation
    1. frac-times97.9%

      \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right) \cdot \sin \left(x \cdot \pi\right)}{\left(x \cdot \pi\right) \cdot \left(x \cdot \left(\pi \cdot tau\right)\right)}} \]
    2. associate-*r*97.4%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right) \cdot \sin \left(x \cdot \pi\right)}{\left(x \cdot \pi\right) \cdot \color{blue}{\left(\left(x \cdot \pi\right) \cdot tau\right)}} \]
    3. associate-*r*97.4%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right) \cdot \sin \left(x \cdot \pi\right)}{\color{blue}{\left(\left(x \cdot \pi\right) \cdot \left(x \cdot \pi\right)\right) \cdot tau}} \]
    4. pow297.4%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right) \cdot \sin \left(x \cdot \pi\right)}{\color{blue}{{\left(x \cdot \pi\right)}^{2}} \cdot tau} \]
  5. Applied egg-rr97.4%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right) \cdot \sin \left(x \cdot \pi\right)}{{\left(x \cdot \pi\right)}^{2} \cdot tau}} \]
  6. Final simplification97.4%

    \[\leadsto \frac{\sin \left(\pi \cdot x\right) \cdot \sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{tau \cdot {\left(\pi \cdot x\right)}^{2}} \]

Alternative 7: 79.3% accurate, 1.2× speedup?

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

\\
\frac{\sin \left(\pi \cdot x\right)}{\pi \cdot x} \cdot \left(1 + {\left(\pi \cdot x\right)}^{2} \cdot \left(-0.16666666666666666 \cdot \left(tau \cdot tau\right)\right)\right)
\end{array}
Derivation
  1. Initial program 97.9%

    \[\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  2. Step-by-step derivation
    1. *-commutative97.9%

      \[\leadsto \frac{\sin \left(\color{blue}{\left(\pi \cdot x\right)} \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    2. associate-*l*97.4%

      \[\leadsto \frac{\sin \color{blue}{\left(\pi \cdot \left(x \cdot tau\right)\right)}}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    3. *-commutative97.4%

      \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\color{blue}{\left(\pi \cdot x\right)} \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    4. associate-*l*98.0%

      \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\color{blue}{\pi \cdot \left(x \cdot tau\right)}} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  3. Simplified98.0%

    \[\leadsto \color{blue}{\frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\pi \cdot \left(x \cdot tau\right)} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}} \]
  4. Taylor expanded in x around 0 80.5%

    \[\leadsto \color{blue}{\left(1 + -0.16666666666666666 \cdot \left({tau}^{2} \cdot \left({x}^{2} \cdot {\pi}^{2}\right)\right)\right)} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  5. Step-by-step derivation
    1. unpow280.5%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\color{blue}{\left(tau \cdot tau\right)} \cdot \left({x}^{2} \cdot {\pi}^{2}\right)\right)\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    2. unpow280.5%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\left(tau \cdot tau\right) \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot {\pi}^{2}\right)\right)\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  6. Simplified80.5%

    \[\leadsto \color{blue}{\left(1 + -0.16666666666666666 \cdot \left(\left(tau \cdot tau\right) \cdot \left(\left(x \cdot x\right) \cdot {\pi}^{2}\right)\right)\right)} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  7. Taylor expanded in tau around 0 80.5%

    \[\leadsto \left(1 + \color{blue}{-0.16666666666666666 \cdot \left({tau}^{2} \cdot \left({x}^{2} \cdot {\pi}^{2}\right)\right)}\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  8. Step-by-step derivation
    1. unpow280.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left({tau}^{2} \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot {\pi}^{2}\right)\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    2. unpow280.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left({tau}^{2} \cdot \left(\left(x \cdot x\right) \cdot \color{blue}{\left(\pi \cdot \pi\right)}\right)\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    3. swap-sqr80.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left({tau}^{2} \cdot \color{blue}{\left(\left(x \cdot \pi\right) \cdot \left(x \cdot \pi\right)\right)}\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    4. unpow280.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left({tau}^{2} \cdot \color{blue}{{\left(x \cdot \pi\right)}^{2}}\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    5. associate-*r*80.2%

      \[\leadsto \left(1 + \color{blue}{\left(-0.16666666666666666 \cdot {tau}^{2}\right) \cdot {\left(x \cdot \pi\right)}^{2}}\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    6. unpow280.2%

      \[\leadsto \left(1 + \left(-0.16666666666666666 \cdot \color{blue}{\left(tau \cdot tau\right)}\right) \cdot {\left(x \cdot \pi\right)}^{2}\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
  9. Simplified80.5%

    \[\leadsto \left(1 + \color{blue}{\left(-0.16666666666666666 \cdot \left(tau \cdot tau\right)\right) \cdot {\left(x \cdot \pi\right)}^{2}}\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  10. Final simplification80.5%

    \[\leadsto \frac{\sin \left(\pi \cdot x\right)}{\pi \cdot x} \cdot \left(1 + {\left(\pi \cdot x\right)}^{2} \cdot \left(-0.16666666666666666 \cdot \left(tau \cdot tau\right)\right)\right) \]

Alternative 8: 85.1% accurate, 1.2× speedup?

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

\\
\begin{array}{l}
t_1 := \pi \cdot \left(x \cdot tau\right)\\
\frac{\sin t_1}{t_1} \cdot \left(1 + {\left(\pi \cdot x\right)}^{2} \cdot -0.16666666666666666\right)
\end{array}
\end{array}
Derivation
  1. Initial program 97.9%

    \[\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  2. Step-by-step derivation
    1. *-commutative97.9%

      \[\leadsto \frac{\sin \left(\color{blue}{\left(\pi \cdot x\right)} \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    2. associate-*l*97.4%

      \[\leadsto \frac{\sin \color{blue}{\left(\pi \cdot \left(x \cdot tau\right)\right)}}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    3. *-commutative97.4%

      \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\color{blue}{\left(\pi \cdot x\right)} \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    4. associate-*l*98.0%

      \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\color{blue}{\pi \cdot \left(x \cdot tau\right)}} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  3. Simplified98.0%

    \[\leadsto \color{blue}{\frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\pi \cdot \left(x \cdot tau\right)} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}} \]
  4. Step-by-step derivation
    1. add-sqr-sqrt97.8%

      \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\pi \cdot \left(x \cdot tau\right)} \cdot \color{blue}{\left(\sqrt{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}} \cdot \sqrt{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}\right)} \]
    2. pow297.8%

      \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\pi \cdot \left(x \cdot tau\right)} \cdot \color{blue}{{\left(\sqrt{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}\right)}^{2}} \]
  5. Applied egg-rr97.8%

    \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\pi \cdot \left(x \cdot tau\right)} \cdot \color{blue}{{\left(\sqrt{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}\right)}^{2}} \]
  6. Taylor expanded in x around 0 85.9%

    \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\pi \cdot \left(x \cdot tau\right)} \cdot \color{blue}{\left(1 + -0.16666666666666666 \cdot \left({x}^{2} \cdot {\pi}^{2}\right)\right)} \]
  7. Step-by-step derivation
    1. unpow285.9%

      \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\pi \cdot \left(x \cdot tau\right)} \cdot \left(1 + -0.16666666666666666 \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot {\pi}^{2}\right)\right) \]
    2. unpow285.9%

      \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\pi \cdot \left(x \cdot tau\right)} \cdot \left(1 + -0.16666666666666666 \cdot \left(\left(x \cdot x\right) \cdot \color{blue}{\left(\pi \cdot \pi\right)}\right)\right) \]
    3. swap-sqr85.9%

      \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\pi \cdot \left(x \cdot tau\right)} \cdot \left(1 + -0.16666666666666666 \cdot \color{blue}{\left(\left(x \cdot \pi\right) \cdot \left(x \cdot \pi\right)\right)}\right) \]
    4. unpow285.9%

      \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\pi \cdot \left(x \cdot tau\right)} \cdot \left(1 + -0.16666666666666666 \cdot \color{blue}{{\left(x \cdot \pi\right)}^{2}}\right) \]
  8. Simplified85.9%

    \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\pi \cdot \left(x \cdot tau\right)} \cdot \color{blue}{\left(1 + -0.16666666666666666 \cdot {\left(x \cdot \pi\right)}^{2}\right)} \]
  9. Final simplification85.9%

    \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\pi \cdot \left(x \cdot tau\right)} \cdot \left(1 + {\left(\pi \cdot x\right)}^{2} \cdot -0.16666666666666666\right) \]

Alternative 9: 79.3% accurate, 1.2× speedup?

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

\\
\frac{\sin \left(\pi \cdot x\right)}{\pi \cdot x} \cdot \left(1 + -0.16666666666666666 \cdot {\left(x \cdot \left(\pi \cdot tau\right)\right)}^{2}\right)
\end{array}
Derivation
  1. Initial program 97.9%

    \[\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  2. Step-by-step derivation
    1. *-commutative97.9%

      \[\leadsto \frac{\sin \left(\color{blue}{\left(\pi \cdot x\right)} \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    2. associate-*l*97.4%

      \[\leadsto \frac{\sin \color{blue}{\left(\pi \cdot \left(x \cdot tau\right)\right)}}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    3. *-commutative97.4%

      \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\color{blue}{\left(\pi \cdot x\right)} \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    4. associate-*l*98.0%

      \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\color{blue}{\pi \cdot \left(x \cdot tau\right)}} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  3. Simplified98.0%

    \[\leadsto \color{blue}{\frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\pi \cdot \left(x \cdot tau\right)} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}} \]
  4. Taylor expanded in x around 0 80.5%

    \[\leadsto \color{blue}{\left(1 + -0.16666666666666666 \cdot \left({tau}^{2} \cdot \left({x}^{2} \cdot {\pi}^{2}\right)\right)\right)} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  5. Step-by-step derivation
    1. unpow280.5%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\color{blue}{\left(tau \cdot tau\right)} \cdot \left({x}^{2} \cdot {\pi}^{2}\right)\right)\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    2. unpow280.5%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\left(tau \cdot tau\right) \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot {\pi}^{2}\right)\right)\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  6. Simplified80.5%

    \[\leadsto \color{blue}{\left(1 + -0.16666666666666666 \cdot \left(\left(tau \cdot tau\right) \cdot \left(\left(x \cdot x\right) \cdot {\pi}^{2}\right)\right)\right)} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  7. Taylor expanded in tau around 0 80.5%

    \[\leadsto \left(1 + \color{blue}{-0.16666666666666666 \cdot \left({tau}^{2} \cdot \left({x}^{2} \cdot {\pi}^{2}\right)\right)}\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  8. Step-by-step derivation
    1. unpow280.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\color{blue}{\left(tau \cdot tau\right)} \cdot \left({x}^{2} \cdot {\pi}^{2}\right)\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    2. unpow280.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\left(tau \cdot tau\right) \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot {\pi}^{2}\right)\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    3. unpow280.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\left(tau \cdot tau\right) \cdot \left(\left(x \cdot x\right) \cdot \color{blue}{\left(\pi \cdot \pi\right)}\right)\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    4. swap-sqr80.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\left(tau \cdot tau\right) \cdot \color{blue}{\left(\left(x \cdot \pi\right) \cdot \left(x \cdot \pi\right)\right)}\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    5. swap-sqr80.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \color{blue}{\left(\left(tau \cdot \left(x \cdot \pi\right)\right) \cdot \left(tau \cdot \left(x \cdot \pi\right)\right)\right)}\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    6. *-commutative80.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\color{blue}{\left(\left(x \cdot \pi\right) \cdot tau\right)} \cdot \left(tau \cdot \left(x \cdot \pi\right)\right)\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    7. associate-*r*80.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\color{blue}{\left(x \cdot \left(\pi \cdot tau\right)\right)} \cdot \left(tau \cdot \left(x \cdot \pi\right)\right)\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    8. *-commutative80.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\left(x \cdot \left(\pi \cdot tau\right)\right) \cdot \color{blue}{\left(\left(x \cdot \pi\right) \cdot tau\right)}\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    9. associate-*r*80.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\left(x \cdot \left(\pi \cdot tau\right)\right) \cdot \color{blue}{\left(x \cdot \left(\pi \cdot tau\right)\right)}\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    10. unpow280.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \color{blue}{{\left(x \cdot \left(\pi \cdot tau\right)\right)}^{2}}\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
  9. Simplified80.5%

    \[\leadsto \left(1 + \color{blue}{-0.16666666666666666 \cdot {\left(x \cdot \left(\pi \cdot tau\right)\right)}^{2}}\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  10. Final simplification80.5%

    \[\leadsto \frac{\sin \left(\pi \cdot x\right)}{\pi \cdot x} \cdot \left(1 + -0.16666666666666666 \cdot {\left(x \cdot \left(\pi \cdot tau\right)\right)}^{2}\right) \]

Alternative 10: 79.1% accurate, 1.2× speedup?

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

\\
\sin \left(\pi \cdot x\right) \cdot \mathsf{fma}\left(-0.16666666666666666, \pi \cdot \left(x \cdot \left(tau \cdot tau\right)\right), \frac{1}{\pi \cdot x}\right)
\end{array}
Derivation
  1. Initial program 97.9%

    \[\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  2. Step-by-step derivation
    1. associate-*l/97.9%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{\left(x \cdot \pi\right) \cdot tau}} \]
    2. times-frac97.4%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau}} \]
    3. associate-*l*97.0%

      \[\leadsto \frac{\sin \color{blue}{\left(x \cdot \left(\pi \cdot tau\right)\right)}}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau} \]
    4. associate-/l/97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{tau \cdot \left(x \cdot \pi\right)}} \]
    5. *-commutative97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{\left(x \cdot \pi\right) \cdot tau}} \]
    6. associate-*l*97.6%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{x \cdot \left(\pi \cdot tau\right)}} \]
  3. Simplified97.6%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}} \]
  4. Step-by-step derivation
    1. add-cube-cbrt97.1%

      \[\leadsto \color{blue}{\left(\sqrt[3]{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}} \cdot \sqrt[3]{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}}\right) \cdot \sqrt[3]{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}}} \]
    2. pow397.2%

      \[\leadsto \color{blue}{{\left(\sqrt[3]{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}}\right)}^{3}} \]
  5. Applied egg-rr96.9%

    \[\leadsto \color{blue}{{\left(\sqrt[3]{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\frac{{\left(x \cdot \pi\right)}^{2} \cdot tau}{\sin \left(x \cdot \pi\right)}}}\right)}^{3}} \]
  6. Step-by-step derivation
    1. rem-cube-cbrt97.1%

      \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\frac{{\left(x \cdot \pi\right)}^{2} \cdot tau}{\sin \left(x \cdot \pi\right)}}} \]
    2. associate-/r/97.2%

      \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{{\left(x \cdot \pi\right)}^{2} \cdot tau} \cdot \sin \left(x \cdot \pi\right)} \]
    3. *-commutative97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\color{blue}{tau \cdot {\left(x \cdot \pi\right)}^{2}}} \cdot \sin \left(x \cdot \pi\right) \]
  7. Applied egg-rr97.2%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{tau \cdot {\left(x \cdot \pi\right)}^{2}} \cdot \sin \left(x \cdot \pi\right)} \]
  8. Taylor expanded in x around 0 80.4%

    \[\leadsto \color{blue}{\left(-0.16666666666666666 \cdot \left({tau}^{2} \cdot \left(x \cdot \pi\right)\right) + \frac{1}{x \cdot \pi}\right)} \cdot \sin \left(x \cdot \pi\right) \]
  9. Step-by-step derivation
    1. fma-def80.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(-0.16666666666666666, {tau}^{2} \cdot \left(x \cdot \pi\right), \frac{1}{x \cdot \pi}\right)} \cdot \sin \left(x \cdot \pi\right) \]
    2. associate-*r*80.4%

      \[\leadsto \mathsf{fma}\left(-0.16666666666666666, \color{blue}{\left({tau}^{2} \cdot x\right) \cdot \pi}, \frac{1}{x \cdot \pi}\right) \cdot \sin \left(x \cdot \pi\right) \]
    3. unpow280.4%

      \[\leadsto \mathsf{fma}\left(-0.16666666666666666, \left(\color{blue}{\left(tau \cdot tau\right)} \cdot x\right) \cdot \pi, \frac{1}{x \cdot \pi}\right) \cdot \sin \left(x \cdot \pi\right) \]
  10. Simplified80.4%

    \[\leadsto \color{blue}{\mathsf{fma}\left(-0.16666666666666666, \left(\left(tau \cdot tau\right) \cdot x\right) \cdot \pi, \frac{1}{x \cdot \pi}\right)} \cdot \sin \left(x \cdot \pi\right) \]
  11. Final simplification80.4%

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

Alternative 11: 79.2% accurate, 1.5× speedup?

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

\\
\left(1 + {\left(\pi \cdot x\right)}^{2} \cdot \left(-0.16666666666666666 \cdot \left(tau \cdot tau\right)\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right)
\end{array}
Derivation
  1. Initial program 97.9%

    \[\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  2. Step-by-step derivation
    1. *-commutative97.9%

      \[\leadsto \frac{\sin \left(\color{blue}{\left(\pi \cdot x\right)} \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    2. associate-*l*97.4%

      \[\leadsto \frac{\sin \color{blue}{\left(\pi \cdot \left(x \cdot tau\right)\right)}}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    3. *-commutative97.4%

      \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\color{blue}{\left(\pi \cdot x\right)} \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    4. associate-*l*98.0%

      \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\color{blue}{\pi \cdot \left(x \cdot tau\right)}} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  3. Simplified98.0%

    \[\leadsto \color{blue}{\frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\pi \cdot \left(x \cdot tau\right)} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}} \]
  4. Taylor expanded in x around 0 80.5%

    \[\leadsto \color{blue}{\left(1 + -0.16666666666666666 \cdot \left({tau}^{2} \cdot \left({x}^{2} \cdot {\pi}^{2}\right)\right)\right)} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  5. Step-by-step derivation
    1. unpow280.5%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\color{blue}{\left(tau \cdot tau\right)} \cdot \left({x}^{2} \cdot {\pi}^{2}\right)\right)\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    2. unpow280.5%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\left(tau \cdot tau\right) \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot {\pi}^{2}\right)\right)\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  6. Simplified80.5%

    \[\leadsto \color{blue}{\left(1 + -0.16666666666666666 \cdot \left(\left(tau \cdot tau\right) \cdot \left(\left(x \cdot x\right) \cdot {\pi}^{2}\right)\right)\right)} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  7. Taylor expanded in x around 0 80.2%

    \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\left(tau \cdot tau\right) \cdot \left(\left(x \cdot x\right) \cdot {\pi}^{2}\right)\right)\right) \cdot \color{blue}{\left(1 + -0.16666666666666666 \cdot \left({x}^{2} \cdot {\pi}^{2}\right)\right)} \]
  8. Step-by-step derivation
    1. associate-*r*65.5%

      \[\leadsto 1 + \color{blue}{\left(-0.16666666666666666 \cdot {x}^{2}\right) \cdot {\pi}^{2}} \]
    2. unpow265.5%

      \[\leadsto 1 + \left(-0.16666666666666666 \cdot \color{blue}{\left(x \cdot x\right)}\right) \cdot {\pi}^{2} \]
  9. Simplified80.2%

    \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\left(tau \cdot tau\right) \cdot \left(\left(x \cdot x\right) \cdot {\pi}^{2}\right)\right)\right) \cdot \color{blue}{\left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right)} \]
  10. Taylor expanded in tau around 0 80.2%

    \[\leadsto \left(1 + \color{blue}{-0.16666666666666666 \cdot \left({tau}^{2} \cdot \left({x}^{2} \cdot {\pi}^{2}\right)\right)}\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
  11. Step-by-step derivation
    1. unpow280.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left({tau}^{2} \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot {\pi}^{2}\right)\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    2. unpow280.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left({tau}^{2} \cdot \left(\left(x \cdot x\right) \cdot \color{blue}{\left(\pi \cdot \pi\right)}\right)\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    3. swap-sqr80.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left({tau}^{2} \cdot \color{blue}{\left(\left(x \cdot \pi\right) \cdot \left(x \cdot \pi\right)\right)}\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    4. unpow280.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left({tau}^{2} \cdot \color{blue}{{\left(x \cdot \pi\right)}^{2}}\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    5. associate-*r*80.2%

      \[\leadsto \left(1 + \color{blue}{\left(-0.16666666666666666 \cdot {tau}^{2}\right) \cdot {\left(x \cdot \pi\right)}^{2}}\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    6. unpow280.2%

      \[\leadsto \left(1 + \left(-0.16666666666666666 \cdot \color{blue}{\left(tau \cdot tau\right)}\right) \cdot {\left(x \cdot \pi\right)}^{2}\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
  12. Simplified80.2%

    \[\leadsto \left(1 + \color{blue}{\left(-0.16666666666666666 \cdot \left(tau \cdot tau\right)\right) \cdot {\left(x \cdot \pi\right)}^{2}}\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
  13. Final simplification80.2%

    \[\leadsto \left(1 + {\left(\pi \cdot x\right)}^{2} \cdot \left(-0.16666666666666666 \cdot \left(tau \cdot tau\right)\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]

Alternative 12: 79.2% accurate, 1.5× speedup?

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

\\
\left(1 + -0.16666666666666666 \cdot {\left(x \cdot \left(\pi \cdot tau\right)\right)}^{2}\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right)
\end{array}
Derivation
  1. Initial program 97.9%

    \[\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  2. Step-by-step derivation
    1. *-commutative97.9%

      \[\leadsto \frac{\sin \left(\color{blue}{\left(\pi \cdot x\right)} \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    2. associate-*l*97.4%

      \[\leadsto \frac{\sin \color{blue}{\left(\pi \cdot \left(x \cdot tau\right)\right)}}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    3. *-commutative97.4%

      \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\color{blue}{\left(\pi \cdot x\right)} \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    4. associate-*l*98.0%

      \[\leadsto \frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\color{blue}{\pi \cdot \left(x \cdot tau\right)}} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  3. Simplified98.0%

    \[\leadsto \color{blue}{\frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{\pi \cdot \left(x \cdot tau\right)} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}} \]
  4. Taylor expanded in x around 0 80.5%

    \[\leadsto \color{blue}{\left(1 + -0.16666666666666666 \cdot \left({tau}^{2} \cdot \left({x}^{2} \cdot {\pi}^{2}\right)\right)\right)} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  5. Step-by-step derivation
    1. unpow280.5%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\color{blue}{\left(tau \cdot tau\right)} \cdot \left({x}^{2} \cdot {\pi}^{2}\right)\right)\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
    2. unpow280.5%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\left(tau \cdot tau\right) \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot {\pi}^{2}\right)\right)\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  6. Simplified80.5%

    \[\leadsto \color{blue}{\left(1 + -0.16666666666666666 \cdot \left(\left(tau \cdot tau\right) \cdot \left(\left(x \cdot x\right) \cdot {\pi}^{2}\right)\right)\right)} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  7. Taylor expanded in x around 0 80.2%

    \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\left(tau \cdot tau\right) \cdot \left(\left(x \cdot x\right) \cdot {\pi}^{2}\right)\right)\right) \cdot \color{blue}{\left(1 + -0.16666666666666666 \cdot \left({x}^{2} \cdot {\pi}^{2}\right)\right)} \]
  8. Step-by-step derivation
    1. associate-*r*65.5%

      \[\leadsto 1 + \color{blue}{\left(-0.16666666666666666 \cdot {x}^{2}\right) \cdot {\pi}^{2}} \]
    2. unpow265.5%

      \[\leadsto 1 + \left(-0.16666666666666666 \cdot \color{blue}{\left(x \cdot x\right)}\right) \cdot {\pi}^{2} \]
  9. Simplified80.2%

    \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\left(tau \cdot tau\right) \cdot \left(\left(x \cdot x\right) \cdot {\pi}^{2}\right)\right)\right) \cdot \color{blue}{\left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right)} \]
  10. Taylor expanded in tau around 0 80.2%

    \[\leadsto \left(1 + \color{blue}{-0.16666666666666666 \cdot \left({tau}^{2} \cdot \left({x}^{2} \cdot {\pi}^{2}\right)\right)}\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
  11. Step-by-step derivation
    1. unpow280.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\color{blue}{\left(tau \cdot tau\right)} \cdot \left({x}^{2} \cdot {\pi}^{2}\right)\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    2. unpow280.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\left(tau \cdot tau\right) \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot {\pi}^{2}\right)\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    3. unpow280.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\left(tau \cdot tau\right) \cdot \left(\left(x \cdot x\right) \cdot \color{blue}{\left(\pi \cdot \pi\right)}\right)\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    4. swap-sqr80.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\left(tau \cdot tau\right) \cdot \color{blue}{\left(\left(x \cdot \pi\right) \cdot \left(x \cdot \pi\right)\right)}\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    5. swap-sqr80.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \color{blue}{\left(\left(tau \cdot \left(x \cdot \pi\right)\right) \cdot \left(tau \cdot \left(x \cdot \pi\right)\right)\right)}\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    6. *-commutative80.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\color{blue}{\left(\left(x \cdot \pi\right) \cdot tau\right)} \cdot \left(tau \cdot \left(x \cdot \pi\right)\right)\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    7. associate-*r*80.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\color{blue}{\left(x \cdot \left(\pi \cdot tau\right)\right)} \cdot \left(tau \cdot \left(x \cdot \pi\right)\right)\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    8. *-commutative80.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\left(x \cdot \left(\pi \cdot tau\right)\right) \cdot \color{blue}{\left(\left(x \cdot \pi\right) \cdot tau\right)}\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    9. associate-*r*80.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \left(\left(x \cdot \left(\pi \cdot tau\right)\right) \cdot \color{blue}{\left(x \cdot \left(\pi \cdot tau\right)\right)}\right)\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
    10. unpow280.2%

      \[\leadsto \left(1 + -0.16666666666666666 \cdot \color{blue}{{\left(x \cdot \left(\pi \cdot tau\right)\right)}^{2}}\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
  12. Simplified80.2%

    \[\leadsto \left(1 + \color{blue}{-0.16666666666666666 \cdot {\left(x \cdot \left(\pi \cdot tau\right)\right)}^{2}}\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]
  13. Final simplification80.2%

    \[\leadsto \left(1 + -0.16666666666666666 \cdot {\left(x \cdot \left(\pi \cdot tau\right)\right)}^{2}\right) \cdot \left(1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}\right) \]

Alternative 13: 78.5% accurate, 2.0× speedup?

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

\\
1 + -0.16666666666666666 \cdot \left({\left(\pi \cdot x\right)}^{2} \cdot \mathsf{fma}\left(tau, tau, 1\right)\right)
\end{array}
Derivation
  1. Initial program 97.9%

    \[\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  2. Step-by-step derivation
    1. associate-*l/97.9%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{\left(x \cdot \pi\right) \cdot tau}} \]
    2. times-frac97.4%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau}} \]
    3. associate-*l*97.0%

      \[\leadsto \frac{\sin \color{blue}{\left(x \cdot \left(\pi \cdot tau\right)\right)}}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau} \]
    4. associate-/l/97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{tau \cdot \left(x \cdot \pi\right)}} \]
    5. *-commutative97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{\left(x \cdot \pi\right) \cdot tau}} \]
    6. associate-*l*97.6%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{x \cdot \left(\pi \cdot tau\right)}} \]
  3. Simplified97.6%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}} \]
  4. Step-by-step derivation
    1. *-commutative97.6%

      \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)} \cdot \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi}} \]
    2. associate-/r*97.4%

      \[\leadsto \color{blue}{\frac{\frac{\sin \left(x \cdot \pi\right)}{x}}{\pi \cdot tau}} \cdot \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \]
    3. frac-times97.6%

      \[\leadsto \color{blue}{\frac{\frac{\sin \left(x \cdot \pi\right)}{x} \cdot \sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\left(\pi \cdot tau\right) \cdot \left(x \cdot \pi\right)}} \]
  5. Applied egg-rr97.6%

    \[\leadsto \color{blue}{\frac{\frac{\sin \left(x \cdot \pi\right)}{x} \cdot \sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\left(\pi \cdot tau\right) \cdot \left(x \cdot \pi\right)}} \]
  6. Step-by-step derivation
    1. add-log-exp97.6%

      \[\leadsto \frac{\color{blue}{\log \left(e^{\frac{\sin \left(x \cdot \pi\right)}{x}}\right)} \cdot \sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\left(\pi \cdot tau\right) \cdot \left(x \cdot \pi\right)} \]
  7. Applied egg-rr97.6%

    \[\leadsto \frac{\color{blue}{\log \left(e^{\frac{\sin \left(x \cdot \pi\right)}{x}}\right)} \cdot \sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\left(\pi \cdot tau\right) \cdot \left(x \cdot \pi\right)} \]
  8. Taylor expanded in x around 0 79.8%

    \[\leadsto \color{blue}{1 + {x}^{2} \cdot \left(-0.16666666666666666 \cdot \left({tau}^{2} \cdot {\pi}^{2}\right) + -0.16666666666666666 \cdot {\pi}^{2}\right)} \]
  9. Step-by-step derivation
    1. *-commutative79.8%

      \[\leadsto 1 + \color{blue}{\left(-0.16666666666666666 \cdot \left({tau}^{2} \cdot {\pi}^{2}\right) + -0.16666666666666666 \cdot {\pi}^{2}\right) \cdot {x}^{2}} \]
    2. distribute-lft-out79.8%

      \[\leadsto 1 + \color{blue}{\left(-0.16666666666666666 \cdot \left({tau}^{2} \cdot {\pi}^{2} + {\pi}^{2}\right)\right)} \cdot {x}^{2} \]
    3. associate-*r*79.8%

      \[\leadsto 1 + \color{blue}{-0.16666666666666666 \cdot \left(\left({tau}^{2} \cdot {\pi}^{2} + {\pi}^{2}\right) \cdot {x}^{2}\right)} \]
    4. distribute-lft1-in79.8%

      \[\leadsto 1 + -0.16666666666666666 \cdot \left(\color{blue}{\left(\left({tau}^{2} + 1\right) \cdot {\pi}^{2}\right)} \cdot {x}^{2}\right) \]
    5. associate-*l*79.8%

      \[\leadsto 1 + -0.16666666666666666 \cdot \color{blue}{\left(\left({tau}^{2} + 1\right) \cdot \left({\pi}^{2} \cdot {x}^{2}\right)\right)} \]
    6. unpow279.8%

      \[\leadsto 1 + -0.16666666666666666 \cdot \left(\left(\color{blue}{tau \cdot tau} + 1\right) \cdot \left({\pi}^{2} \cdot {x}^{2}\right)\right) \]
    7. fma-def79.8%

      \[\leadsto 1 + -0.16666666666666666 \cdot \left(\color{blue}{\mathsf{fma}\left(tau, tau, 1\right)} \cdot \left({\pi}^{2} \cdot {x}^{2}\right)\right) \]
    8. *-commutative79.8%

      \[\leadsto 1 + -0.16666666666666666 \cdot \left(\mathsf{fma}\left(tau, tau, 1\right) \cdot \color{blue}{\left({x}^{2} \cdot {\pi}^{2}\right)}\right) \]
    9. unpow279.8%

      \[\leadsto 1 + -0.16666666666666666 \cdot \left(\mathsf{fma}\left(tau, tau, 1\right) \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot {\pi}^{2}\right)\right) \]
    10. unpow279.8%

      \[\leadsto 1 + -0.16666666666666666 \cdot \left(\mathsf{fma}\left(tau, tau, 1\right) \cdot \left(\left(x \cdot x\right) \cdot \color{blue}{\left(\pi \cdot \pi\right)}\right)\right) \]
    11. swap-sqr79.8%

      \[\leadsto 1 + -0.16666666666666666 \cdot \left(\mathsf{fma}\left(tau, tau, 1\right) \cdot \color{blue}{\left(\left(x \cdot \pi\right) \cdot \left(x \cdot \pi\right)\right)}\right) \]
    12. unpow279.8%

      \[\leadsto 1 + -0.16666666666666666 \cdot \left(\mathsf{fma}\left(tau, tau, 1\right) \cdot \color{blue}{{\left(x \cdot \pi\right)}^{2}}\right) \]
    13. *-commutative79.8%

      \[\leadsto 1 + -0.16666666666666666 \cdot \left(\mathsf{fma}\left(tau, tau, 1\right) \cdot {\color{blue}{\left(\pi \cdot x\right)}}^{2}\right) \]
  10. Simplified79.8%

    \[\leadsto \color{blue}{1 + -0.16666666666666666 \cdot \left(\mathsf{fma}\left(tau, tau, 1\right) \cdot {\left(\pi \cdot x\right)}^{2}\right)} \]
  11. Final simplification79.8%

    \[\leadsto 1 + -0.16666666666666666 \cdot \left({\left(\pi \cdot x\right)}^{2} \cdot \mathsf{fma}\left(tau, tau, 1\right)\right) \]

Alternative 14: 78.5% accurate, 2.9× speedup?

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

\\
1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot \left({\pi}^{2} \cdot \left(1 + tau \cdot tau\right)\right)
\end{array}
Derivation
  1. Initial program 97.9%

    \[\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  2. Step-by-step derivation
    1. associate-*l/97.9%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{\left(x \cdot \pi\right) \cdot tau}} \]
    2. times-frac97.4%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau}} \]
    3. associate-*l*97.0%

      \[\leadsto \frac{\sin \color{blue}{\left(x \cdot \left(\pi \cdot tau\right)\right)}}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau} \]
    4. associate-/l/97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{tau \cdot \left(x \cdot \pi\right)}} \]
    5. *-commutative97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{\left(x \cdot \pi\right) \cdot tau}} \]
    6. associate-*l*97.6%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{x \cdot \left(\pi \cdot tau\right)}} \]
  3. Simplified97.6%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}} \]
  4. Step-by-step derivation
    1. *-commutative97.6%

      \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)} \cdot \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi}} \]
    2. clear-num97.7%

      \[\leadsto \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)} \cdot \color{blue}{\frac{1}{\frac{x \cdot \pi}{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}}} \]
    3. un-div-inv97.8%

      \[\leadsto \color{blue}{\frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}}{\frac{x \cdot \pi}{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}}} \]
    4. associate-/l*97.2%

      \[\leadsto \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}}{\color{blue}{\frac{x}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\pi}}}} \]
  5. Applied egg-rr97.2%

    \[\leadsto \color{blue}{\frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}}{\frac{x}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\pi}}}} \]
  6. Taylor expanded in x around 0 79.8%

    \[\leadsto \color{blue}{1 + {x}^{2} \cdot \left(-0.16666666666666666 \cdot \left({tau}^{2} \cdot {\pi}^{2}\right) + -0.16666666666666666 \cdot {\pi}^{2}\right)} \]
  7. Step-by-step derivation
    1. unpow279.8%

      \[\leadsto 1 + \color{blue}{\left(x \cdot x\right)} \cdot \left(-0.16666666666666666 \cdot \left({tau}^{2} \cdot {\pi}^{2}\right) + -0.16666666666666666 \cdot {\pi}^{2}\right) \]
    2. distribute-lft-out79.8%

      \[\leadsto 1 + \left(x \cdot x\right) \cdot \color{blue}{\left(-0.16666666666666666 \cdot \left({tau}^{2} \cdot {\pi}^{2} + {\pi}^{2}\right)\right)} \]
    3. *-commutative79.8%

      \[\leadsto 1 + \left(x \cdot x\right) \cdot \left(-0.16666666666666666 \cdot \left(\color{blue}{{\pi}^{2} \cdot {tau}^{2}} + {\pi}^{2}\right)\right) \]
    4. unpow279.8%

      \[\leadsto 1 + \left(x \cdot x\right) \cdot \left(-0.16666666666666666 \cdot \left({\pi}^{2} \cdot \color{blue}{\left(tau \cdot tau\right)} + {\pi}^{2}\right)\right) \]
  8. Simplified79.8%

    \[\leadsto \color{blue}{1 + \left(x \cdot x\right) \cdot \left(-0.16666666666666666 \cdot \left({\pi}^{2} \cdot \left(tau \cdot tau\right) + {\pi}^{2}\right)\right)} \]
  9. Taylor expanded in x around 0 79.8%

    \[\leadsto 1 + \color{blue}{-0.16666666666666666 \cdot \left({x}^{2} \cdot \left({tau}^{2} \cdot {\pi}^{2} + {\pi}^{2}\right)\right)} \]
  10. Step-by-step derivation
    1. associate-*r*79.8%

      \[\leadsto 1 + \color{blue}{\left(-0.16666666666666666 \cdot {x}^{2}\right) \cdot \left({tau}^{2} \cdot {\pi}^{2} + {\pi}^{2}\right)} \]
    2. unpow279.8%

      \[\leadsto 1 + \left(-0.16666666666666666 \cdot \color{blue}{\left(x \cdot x\right)}\right) \cdot \left({tau}^{2} \cdot {\pi}^{2} + {\pi}^{2}\right) \]
    3. distribute-lft1-in79.8%

      \[\leadsto 1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot \color{blue}{\left(\left({tau}^{2} + 1\right) \cdot {\pi}^{2}\right)} \]
    4. unpow279.8%

      \[\leadsto 1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot \left(\left(\color{blue}{tau \cdot tau} + 1\right) \cdot {\pi}^{2}\right) \]
  11. Simplified79.8%

    \[\leadsto 1 + \color{blue}{\left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot \left(\left(tau \cdot tau + 1\right) \cdot {\pi}^{2}\right)} \]
  12. Final simplification79.8%

    \[\leadsto 1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot \left({\pi}^{2} \cdot \left(1 + tau \cdot tau\right)\right) \]

Alternative 15: 69.6% accurate, 2.9× speedup?

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

\\
1 + \left(x \cdot x\right) \cdot \left(-0.16666666666666666 \cdot {\left(\pi \cdot tau\right)}^{2}\right)
\end{array}
Derivation
  1. Initial program 97.9%

    \[\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  2. Step-by-step derivation
    1. associate-*l/97.9%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{\left(x \cdot \pi\right) \cdot tau}} \]
    2. times-frac97.4%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau}} \]
    3. associate-*l*97.0%

      \[\leadsto \frac{\sin \color{blue}{\left(x \cdot \left(\pi \cdot tau\right)\right)}}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau} \]
    4. associate-/l/97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{tau \cdot \left(x \cdot \pi\right)}} \]
    5. *-commutative97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{\left(x \cdot \pi\right) \cdot tau}} \]
    6. associate-*l*97.6%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{x \cdot \left(\pi \cdot tau\right)}} \]
  3. Simplified97.6%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}} \]
  4. Step-by-step derivation
    1. *-commutative97.6%

      \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)} \cdot \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi}} \]
    2. clear-num97.7%

      \[\leadsto \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)} \cdot \color{blue}{\frac{1}{\frac{x \cdot \pi}{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}}} \]
    3. un-div-inv97.8%

      \[\leadsto \color{blue}{\frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}}{\frac{x \cdot \pi}{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}}} \]
    4. associate-/l*97.2%

      \[\leadsto \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}}{\color{blue}{\frac{x}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\pi}}}} \]
  5. Applied egg-rr97.2%

    \[\leadsto \color{blue}{\frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}}{\frac{x}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\pi}}}} \]
  6. Taylor expanded in x around 0 79.8%

    \[\leadsto \color{blue}{1 + {x}^{2} \cdot \left(-0.16666666666666666 \cdot \left({tau}^{2} \cdot {\pi}^{2}\right) + -0.16666666666666666 \cdot {\pi}^{2}\right)} \]
  7. Step-by-step derivation
    1. unpow279.8%

      \[\leadsto 1 + \color{blue}{\left(x \cdot x\right)} \cdot \left(-0.16666666666666666 \cdot \left({tau}^{2} \cdot {\pi}^{2}\right) + -0.16666666666666666 \cdot {\pi}^{2}\right) \]
    2. distribute-lft-out79.8%

      \[\leadsto 1 + \left(x \cdot x\right) \cdot \color{blue}{\left(-0.16666666666666666 \cdot \left({tau}^{2} \cdot {\pi}^{2} + {\pi}^{2}\right)\right)} \]
    3. *-commutative79.8%

      \[\leadsto 1 + \left(x \cdot x\right) \cdot \left(-0.16666666666666666 \cdot \left(\color{blue}{{\pi}^{2} \cdot {tau}^{2}} + {\pi}^{2}\right)\right) \]
    4. unpow279.8%

      \[\leadsto 1 + \left(x \cdot x\right) \cdot \left(-0.16666666666666666 \cdot \left({\pi}^{2} \cdot \color{blue}{\left(tau \cdot tau\right)} + {\pi}^{2}\right)\right) \]
  8. Simplified79.8%

    \[\leadsto \color{blue}{1 + \left(x \cdot x\right) \cdot \left(-0.16666666666666666 \cdot \left({\pi}^{2} \cdot \left(tau \cdot tau\right) + {\pi}^{2}\right)\right)} \]
  9. Taylor expanded in tau around inf 70.6%

    \[\leadsto 1 + \left(x \cdot x\right) \cdot \color{blue}{\left(-0.16666666666666666 \cdot \left({tau}^{2} \cdot {\pi}^{2}\right)\right)} \]
  10. Step-by-step derivation
    1. *-commutative70.6%

      \[\leadsto 1 + \left(x \cdot x\right) \cdot \left(-0.16666666666666666 \cdot \color{blue}{\left({\pi}^{2} \cdot {tau}^{2}\right)}\right) \]
    2. unpow270.6%

      \[\leadsto 1 + \left(x \cdot x\right) \cdot \left(-0.16666666666666666 \cdot \left(\color{blue}{\left(\pi \cdot \pi\right)} \cdot {tau}^{2}\right)\right) \]
    3. unpow270.6%

      \[\leadsto 1 + \left(x \cdot x\right) \cdot \left(-0.16666666666666666 \cdot \left(\left(\pi \cdot \pi\right) \cdot \color{blue}{\left(tau \cdot tau\right)}\right)\right) \]
    4. swap-sqr70.6%

      \[\leadsto 1 + \left(x \cdot x\right) \cdot \left(-0.16666666666666666 \cdot \color{blue}{\left(\left(\pi \cdot tau\right) \cdot \left(\pi \cdot tau\right)\right)}\right) \]
    5. unpow270.6%

      \[\leadsto 1 + \left(x \cdot x\right) \cdot \left(-0.16666666666666666 \cdot \color{blue}{{\left(\pi \cdot tau\right)}^{2}}\right) \]
  11. Simplified70.6%

    \[\leadsto 1 + \left(x \cdot x\right) \cdot \color{blue}{\left(-0.16666666666666666 \cdot {\left(\pi \cdot tau\right)}^{2}\right)} \]
  12. Final simplification70.6%

    \[\leadsto 1 + \left(x \cdot x\right) \cdot \left(-0.16666666666666666 \cdot {\left(\pi \cdot tau\right)}^{2}\right) \]

Alternative 16: 69.6% accurate, 2.9× speedup?

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

\\
1 + {\left(\pi \cdot x\right)}^{2} \cdot \left(-0.16666666666666666 \cdot \left(tau \cdot tau\right)\right)
\end{array}
Derivation
  1. Initial program 97.9%

    \[\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  2. Step-by-step derivation
    1. associate-*l/97.9%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{\left(x \cdot \pi\right) \cdot tau}} \]
    2. times-frac97.4%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau}} \]
    3. associate-*l*97.0%

      \[\leadsto \frac{\sin \color{blue}{\left(x \cdot \left(\pi \cdot tau\right)\right)}}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau} \]
    4. associate-/l/97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{tau \cdot \left(x \cdot \pi\right)}} \]
    5. *-commutative97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{\left(x \cdot \pi\right) \cdot tau}} \]
    6. associate-*l*97.6%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{x \cdot \left(\pi \cdot tau\right)}} \]
  3. Simplified97.6%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}} \]
  4. Step-by-step derivation
    1. *-commutative97.6%

      \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)} \cdot \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi}} \]
    2. clear-num97.7%

      \[\leadsto \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)} \cdot \color{blue}{\frac{1}{\frac{x \cdot \pi}{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}}} \]
    3. un-div-inv97.8%

      \[\leadsto \color{blue}{\frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}}{\frac{x \cdot \pi}{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}}} \]
    4. associate-/l*97.2%

      \[\leadsto \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}}{\color{blue}{\frac{x}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\pi}}}} \]
  5. Applied egg-rr97.2%

    \[\leadsto \color{blue}{\frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}}{\frac{x}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\pi}}}} \]
  6. Taylor expanded in x around 0 79.8%

    \[\leadsto \color{blue}{1 + {x}^{2} \cdot \left(-0.16666666666666666 \cdot \left({tau}^{2} \cdot {\pi}^{2}\right) + -0.16666666666666666 \cdot {\pi}^{2}\right)} \]
  7. Step-by-step derivation
    1. unpow279.8%

      \[\leadsto 1 + \color{blue}{\left(x \cdot x\right)} \cdot \left(-0.16666666666666666 \cdot \left({tau}^{2} \cdot {\pi}^{2}\right) + -0.16666666666666666 \cdot {\pi}^{2}\right) \]
    2. distribute-lft-out79.8%

      \[\leadsto 1 + \left(x \cdot x\right) \cdot \color{blue}{\left(-0.16666666666666666 \cdot \left({tau}^{2} \cdot {\pi}^{2} + {\pi}^{2}\right)\right)} \]
    3. *-commutative79.8%

      \[\leadsto 1 + \left(x \cdot x\right) \cdot \left(-0.16666666666666666 \cdot \left(\color{blue}{{\pi}^{2} \cdot {tau}^{2}} + {\pi}^{2}\right)\right) \]
    4. unpow279.8%

      \[\leadsto 1 + \left(x \cdot x\right) \cdot \left(-0.16666666666666666 \cdot \left({\pi}^{2} \cdot \color{blue}{\left(tau \cdot tau\right)} + {\pi}^{2}\right)\right) \]
  8. Simplified79.8%

    \[\leadsto \color{blue}{1 + \left(x \cdot x\right) \cdot \left(-0.16666666666666666 \cdot \left({\pi}^{2} \cdot \left(tau \cdot tau\right) + {\pi}^{2}\right)\right)} \]
  9. Taylor expanded in tau around inf 70.6%

    \[\leadsto 1 + \color{blue}{-0.16666666666666666 \cdot \left({tau}^{2} \cdot \left({x}^{2} \cdot {\pi}^{2}\right)\right)} \]
  10. Step-by-step derivation
    1. associate-*r*70.6%

      \[\leadsto 1 + \color{blue}{\left(-0.16666666666666666 \cdot {tau}^{2}\right) \cdot \left({x}^{2} \cdot {\pi}^{2}\right)} \]
    2. *-commutative70.6%

      \[\leadsto 1 + \color{blue}{\left({x}^{2} \cdot {\pi}^{2}\right) \cdot \left(-0.16666666666666666 \cdot {tau}^{2}\right)} \]
    3. unpow270.6%

      \[\leadsto 1 + \left({x}^{2} \cdot \color{blue}{\left(\pi \cdot \pi\right)}\right) \cdot \left(-0.16666666666666666 \cdot {tau}^{2}\right) \]
    4. unpow270.6%

      \[\leadsto 1 + \left(\color{blue}{\left(x \cdot x\right)} \cdot \left(\pi \cdot \pi\right)\right) \cdot \left(-0.16666666666666666 \cdot {tau}^{2}\right) \]
    5. swap-sqr70.6%

      \[\leadsto 1 + \color{blue}{\left(\left(x \cdot \pi\right) \cdot \left(x \cdot \pi\right)\right)} \cdot \left(-0.16666666666666666 \cdot {tau}^{2}\right) \]
    6. unpow270.6%

      \[\leadsto 1 + \color{blue}{{\left(x \cdot \pi\right)}^{2}} \cdot \left(-0.16666666666666666 \cdot {tau}^{2}\right) \]
    7. *-commutative70.6%

      \[\leadsto 1 + {\color{blue}{\left(\pi \cdot x\right)}}^{2} \cdot \left(-0.16666666666666666 \cdot {tau}^{2}\right) \]
    8. unpow270.6%

      \[\leadsto 1 + {\left(\pi \cdot x\right)}^{2} \cdot \left(-0.16666666666666666 \cdot \color{blue}{\left(tau \cdot tau\right)}\right) \]
  11. Simplified70.6%

    \[\leadsto 1 + \color{blue}{{\left(\pi \cdot x\right)}^{2} \cdot \left(-0.16666666666666666 \cdot \left(tau \cdot tau\right)\right)} \]
  12. Final simplification70.6%

    \[\leadsto 1 + {\left(\pi \cdot x\right)}^{2} \cdot \left(-0.16666666666666666 \cdot \left(tau \cdot tau\right)\right) \]

Alternative 17: 64.2% accurate, 2.9× speedup?

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

\\
1 + -0.16666666666666666 \cdot \left(\left(x \cdot x\right) \cdot {\pi}^{2}\right)
\end{array}
Derivation
  1. Initial program 97.9%

    \[\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  2. Step-by-step derivation
    1. associate-*l/97.9%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{\left(x \cdot \pi\right) \cdot tau}} \]
    2. times-frac97.4%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau}} \]
    3. associate-*l*97.0%

      \[\leadsto \frac{\sin \color{blue}{\left(x \cdot \left(\pi \cdot tau\right)\right)}}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau} \]
    4. associate-/l/97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{tau \cdot \left(x \cdot \pi\right)}} \]
    5. *-commutative97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{\left(x \cdot \pi\right) \cdot tau}} \]
    6. associate-*l*97.6%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{x \cdot \left(\pi \cdot tau\right)}} \]
  3. Simplified97.6%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}} \]
  4. Taylor expanded in tau around 0 65.0%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}} \]
  5. Taylor expanded in x around 0 65.5%

    \[\leadsto \color{blue}{1 + -0.16666666666666666 \cdot \left({x}^{2} \cdot {\pi}^{2}\right)} \]
  6. Step-by-step derivation
    1. associate-*r*65.5%

      \[\leadsto 1 + \color{blue}{\left(-0.16666666666666666 \cdot {x}^{2}\right) \cdot {\pi}^{2}} \]
    2. unpow265.5%

      \[\leadsto 1 + \left(-0.16666666666666666 \cdot \color{blue}{\left(x \cdot x\right)}\right) \cdot {\pi}^{2} \]
  7. Simplified65.5%

    \[\leadsto \color{blue}{1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}} \]
  8. Taylor expanded in x around 0 65.5%

    \[\leadsto 1 + \color{blue}{-0.16666666666666666 \cdot \left({x}^{2} \cdot {\pi}^{2}\right)} \]
  9. Step-by-step derivation
    1. *-commutative65.5%

      \[\leadsto 1 + -0.16666666666666666 \cdot \color{blue}{\left({\pi}^{2} \cdot {x}^{2}\right)} \]
    2. unpow265.5%

      \[\leadsto 1 + -0.16666666666666666 \cdot \left({\pi}^{2} \cdot \color{blue}{\left(x \cdot x\right)}\right) \]
  10. Simplified65.5%

    \[\leadsto 1 + \color{blue}{-0.16666666666666666 \cdot \left({\pi}^{2} \cdot \left(x \cdot x\right)\right)} \]
  11. Final simplification65.5%

    \[\leadsto 1 + -0.16666666666666666 \cdot \left(\left(x \cdot x\right) \cdot {\pi}^{2}\right) \]

Alternative 18: 64.2% accurate, 3.0× speedup?

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

\\
1 + {\left(\pi \cdot x\right)}^{2} \cdot -0.16666666666666666
\end{array}
Derivation
  1. Initial program 97.9%

    \[\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  2. Step-by-step derivation
    1. associate-*l/97.9%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{\left(x \cdot \pi\right) \cdot tau}} \]
    2. times-frac97.4%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau}} \]
    3. associate-*l*97.0%

      \[\leadsto \frac{\sin \color{blue}{\left(x \cdot \left(\pi \cdot tau\right)\right)}}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau} \]
    4. associate-/l/97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{tau \cdot \left(x \cdot \pi\right)}} \]
    5. *-commutative97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{\left(x \cdot \pi\right) \cdot tau}} \]
    6. associate-*l*97.6%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{x \cdot \left(\pi \cdot tau\right)}} \]
  3. Simplified97.6%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}} \]
  4. Taylor expanded in tau around 0 65.0%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}} \]
  5. Taylor expanded in x around 0 65.5%

    \[\leadsto \color{blue}{1 + -0.16666666666666666 \cdot \left({x}^{2} \cdot {\pi}^{2}\right)} \]
  6. Step-by-step derivation
    1. associate-*r*65.5%

      \[\leadsto 1 + \color{blue}{\left(-0.16666666666666666 \cdot {x}^{2}\right) \cdot {\pi}^{2}} \]
    2. unpow265.5%

      \[\leadsto 1 + \left(-0.16666666666666666 \cdot \color{blue}{\left(x \cdot x\right)}\right) \cdot {\pi}^{2} \]
  7. Simplified65.5%

    \[\leadsto \color{blue}{1 + \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot {\pi}^{2}} \]
  8. Taylor expanded in x around 0 65.5%

    \[\leadsto 1 + \color{blue}{-0.16666666666666666 \cdot \left({x}^{2} \cdot {\pi}^{2}\right)} \]
  9. Step-by-step derivation
    1. unpow265.5%

      \[\leadsto 1 + -0.16666666666666666 \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot {\pi}^{2}\right) \]
    2. unpow265.5%

      \[\leadsto 1 + -0.16666666666666666 \cdot \left(\left(x \cdot x\right) \cdot \color{blue}{\left(\pi \cdot \pi\right)}\right) \]
    3. swap-sqr65.5%

      \[\leadsto 1 + -0.16666666666666666 \cdot \color{blue}{\left(\left(x \cdot \pi\right) \cdot \left(x \cdot \pi\right)\right)} \]
    4. unpow265.5%

      \[\leadsto 1 + -0.16666666666666666 \cdot \color{blue}{{\left(x \cdot \pi\right)}^{2}} \]
  10. Simplified65.5%

    \[\leadsto 1 + \color{blue}{-0.16666666666666666 \cdot {\left(x \cdot \pi\right)}^{2}} \]
  11. Final simplification65.5%

    \[\leadsto 1 + {\left(\pi \cdot x\right)}^{2} \cdot -0.16666666666666666 \]

Alternative 19: 63.3% accurate, 615.0× speedup?

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

\\
1
\end{array}
Derivation
  1. Initial program 97.9%

    \[\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{\left(x \cdot \pi\right) \cdot tau} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \]
  2. Step-by-step derivation
    1. associate-*l/97.9%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{\left(x \cdot \pi\right) \cdot tau}} \]
    2. times-frac97.4%

      \[\leadsto \color{blue}{\frac{\sin \left(\left(x \cdot \pi\right) \cdot tau\right)}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau}} \]
    3. associate-*l*97.0%

      \[\leadsto \frac{\sin \color{blue}{\left(x \cdot \left(\pi \cdot tau\right)\right)}}{x \cdot \pi} \cdot \frac{\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}}{tau} \]
    4. associate-/l/97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \color{blue}{\frac{\sin \left(x \cdot \pi\right)}{tau \cdot \left(x \cdot \pi\right)}} \]
    5. *-commutative97.2%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{\left(x \cdot \pi\right) \cdot tau}} \]
    6. associate-*l*97.6%

      \[\leadsto \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{\color{blue}{x \cdot \left(\pi \cdot tau\right)}} \]
  3. Simplified97.6%

    \[\leadsto \color{blue}{\frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot tau\right)}} \]
  4. Taylor expanded in x around 0 64.2%

    \[\leadsto \color{blue}{1} \]
  5. Final simplification64.2%

    \[\leadsto 1 \]

Reproduce

?
herbie shell --seed 2023275 
(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))))