Beckmann Sample, normalization factor

Percentage Accurate: 97.8% → 97.2%
Time: 15.7s
Alternatives: 11
Speedup: 1.0×

Specification

?
\[\left(0 < cosTheta \land cosTheta < 0.9999\right) \land \left(-1 < c \land c < 1\right)\]
\[\begin{array}{l} \\ \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \end{array} \]
(FPCore (cosTheta c)
 :precision binary32
 (/
  1.0
  (+
   (+ 1.0 c)
   (*
    (* (/ 1.0 (sqrt PI)) (/ (sqrt (- (- 1.0 cosTheta) cosTheta)) cosTheta))
    (exp (* (- cosTheta) cosTheta))))))
float code(float cosTheta, float c) {
	return 1.0f / ((1.0f + c) + (((1.0f / sqrtf(((float) M_PI))) * (sqrtf(((1.0f - cosTheta) - cosTheta)) / cosTheta)) * expf((-cosTheta * cosTheta))));
}
function code(cosTheta, c)
	return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(Float32(Float32(1.0) / sqrt(Float32(pi))) * Float32(sqrt(Float32(Float32(Float32(1.0) - cosTheta) - cosTheta)) / cosTheta)) * exp(Float32(Float32(-cosTheta) * cosTheta)))))
end
function tmp = code(cosTheta, c)
	tmp = single(1.0) / ((single(1.0) + c) + (((single(1.0) / sqrt(single(pi))) * (sqrt(((single(1.0) - cosTheta) - cosTheta)) / cosTheta)) * exp((-cosTheta * cosTheta))));
end
\begin{array}{l}

\\
\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}}
\end{array}

Sampling outcomes in binary32 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 11 alternatives:

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

Initial Program: 97.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \end{array} \]
(FPCore (cosTheta c)
 :precision binary32
 (/
  1.0
  (+
   (+ 1.0 c)
   (*
    (* (/ 1.0 (sqrt PI)) (/ (sqrt (- (- 1.0 cosTheta) cosTheta)) cosTheta))
    (exp (* (- cosTheta) cosTheta))))))
float code(float cosTheta, float c) {
	return 1.0f / ((1.0f + c) + (((1.0f / sqrtf(((float) M_PI))) * (sqrtf(((1.0f - cosTheta) - cosTheta)) / cosTheta)) * expf((-cosTheta * cosTheta))));
}
function code(cosTheta, c)
	return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(Float32(Float32(1.0) / sqrt(Float32(pi))) * Float32(sqrt(Float32(Float32(Float32(1.0) - cosTheta) - cosTheta)) / cosTheta)) * exp(Float32(Float32(-cosTheta) * cosTheta)))))
end
function tmp = code(cosTheta, c)
	tmp = single(1.0) / ((single(1.0) + c) + (((single(1.0) / sqrt(single(pi))) * (sqrt(((single(1.0) - cosTheta) - cosTheta)) / cosTheta)) * exp((-cosTheta * cosTheta))));
end
\begin{array}{l}

\\
\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}}
\end{array}

Alternative 1: 97.2% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sqrt{\frac{1}{\pi}}\\ t_1 := t_0 - c\\ t_2 := 1 - t_1\\ t_3 := \sqrt{{\pi}^{3}}\\ t_4 := t_0 \cdot -1.5\\ t_5 := \mathsf{fma}\left(\pi, t_4, {t_2}^{2} \cdot \left(-t_3\right)\right)\\ \left(\left(cosTheta \cdot \sqrt{\pi} + {cosTheta}^{4} \cdot \left(t_5 \cdot \left(\sqrt{\pi} \cdot t_2\right) + \left(t_2 \cdot \left(t_4 \cdot t_3\right) - 0.5 \cdot \left(\pi \cdot t_0\right)\right)\right)\right) - t_5 \cdot {cosTheta}^{3}\right) + \pi \cdot \left({cosTheta}^{2} \cdot \left(-1 + t_1\right)\right) \end{array} \end{array} \]
(FPCore (cosTheta c)
 :precision binary32
 (let* ((t_0 (sqrt (/ 1.0 PI)))
        (t_1 (- t_0 c))
        (t_2 (- 1.0 t_1))
        (t_3 (sqrt (pow PI 3.0)))
        (t_4 (* t_0 -1.5))
        (t_5 (fma PI t_4 (* (pow t_2 2.0) (- t_3)))))
   (+
    (-
     (+
      (* cosTheta (sqrt PI))
      (*
       (pow cosTheta 4.0)
       (+
        (* t_5 (* (sqrt PI) t_2))
        (- (* t_2 (* t_4 t_3)) (* 0.5 (* PI t_0))))))
     (* t_5 (pow cosTheta 3.0)))
    (* PI (* (pow cosTheta 2.0) (+ -1.0 t_1))))))
float code(float cosTheta, float c) {
	float t_0 = sqrtf((1.0f / ((float) M_PI)));
	float t_1 = t_0 - c;
	float t_2 = 1.0f - t_1;
	float t_3 = sqrtf(powf(((float) M_PI), 3.0f));
	float t_4 = t_0 * -1.5f;
	float t_5 = fmaf(((float) M_PI), t_4, (powf(t_2, 2.0f) * -t_3));
	return (((cosTheta * sqrtf(((float) M_PI))) + (powf(cosTheta, 4.0f) * ((t_5 * (sqrtf(((float) M_PI)) * t_2)) + ((t_2 * (t_4 * t_3)) - (0.5f * (((float) M_PI) * t_0)))))) - (t_5 * powf(cosTheta, 3.0f))) + (((float) M_PI) * (powf(cosTheta, 2.0f) * (-1.0f + t_1)));
}
function code(cosTheta, c)
	t_0 = sqrt(Float32(Float32(1.0) / Float32(pi)))
	t_1 = Float32(t_0 - c)
	t_2 = Float32(Float32(1.0) - t_1)
	t_3 = sqrt((Float32(pi) ^ Float32(3.0)))
	t_4 = Float32(t_0 * Float32(-1.5))
	t_5 = fma(Float32(pi), t_4, Float32((t_2 ^ Float32(2.0)) * Float32(-t_3)))
	return Float32(Float32(Float32(Float32(cosTheta * sqrt(Float32(pi))) + Float32((cosTheta ^ Float32(4.0)) * Float32(Float32(t_5 * Float32(sqrt(Float32(pi)) * t_2)) + Float32(Float32(t_2 * Float32(t_4 * t_3)) - Float32(Float32(0.5) * Float32(Float32(pi) * t_0)))))) - Float32(t_5 * (cosTheta ^ Float32(3.0)))) + Float32(Float32(pi) * Float32((cosTheta ^ Float32(2.0)) * Float32(Float32(-1.0) + t_1))))
end
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sqrt{\frac{1}{\pi}}\\
t_1 := t_0 - c\\
t_2 := 1 - t_1\\
t_3 := \sqrt{{\pi}^{3}}\\
t_4 := t_0 \cdot -1.5\\
t_5 := \mathsf{fma}\left(\pi, t_4, {t_2}^{2} \cdot \left(-t_3\right)\right)\\
\left(\left(cosTheta \cdot \sqrt{\pi} + {cosTheta}^{4} \cdot \left(t_5 \cdot \left(\sqrt{\pi} \cdot t_2\right) + \left(t_2 \cdot \left(t_4 \cdot t_3\right) - 0.5 \cdot \left(\pi \cdot t_0\right)\right)\right)\right) - t_5 \cdot {cosTheta}^{3}\right) + \pi \cdot \left({cosTheta}^{2} \cdot \left(-1 + t_1\right)\right)
\end{array}
\end{array}
Derivation
  1. Initial program 96.9%

    \[\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  2. Step-by-step derivation
    1. +-commutative96.9%

      \[\leadsto \frac{1}{\color{blue}{\left(c + 1\right)} + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    2. associate-+l+96.9%

      \[\leadsto \frac{1}{\color{blue}{c + \left(1 + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)}} \]
    3. *-commutative96.9%

      \[\leadsto \frac{1}{c + \left(1 + \color{blue}{\left(\frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{1}{\sqrt{\pi}}\right)} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)} \]
    4. associate-*l*96.9%

      \[\leadsto \frac{1}{c + \left(1 + \color{blue}{\frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \left(\frac{1}{\sqrt{\pi}} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)}\right)} \]
    5. /-rgt-identity96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \left(\color{blue}{\frac{\frac{1}{\sqrt{\pi}}}{1}} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)\right)} \]
    6. associate-/r/96.8%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \color{blue}{\frac{\frac{1}{\sqrt{\pi}}}{\frac{1}{e^{\left(-cosTheta\right) \cdot cosTheta}}}}\right)} \]
    7. exp-neg96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{\frac{1}{\sqrt{\pi}}}{\color{blue}{e^{-\left(-cosTheta\right) \cdot cosTheta}}}\right)} \]
    8. distribute-rgt-neg-out96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{\frac{1}{\sqrt{\pi}}}{e^{\color{blue}{\left(-cosTheta\right) \cdot \left(-cosTheta\right)}}}\right)} \]
  3. Simplified97.7%

    \[\leadsto \color{blue}{\frac{1}{c + \left(1 + \frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{\sqrt{\pi} \cdot cosTheta}}{{\left(e^{cosTheta}\right)}^{cosTheta}}\right)}} \]
  4. Taylor expanded in cosTheta around 0 97.8%

    \[\leadsto \color{blue}{-1 \cdot \left({cosTheta}^{2} \cdot \left(\pi \cdot \left(1 + \left(c + -1 \cdot \sqrt{\frac{1}{\pi}}\right)\right)\right)\right) + \left(-1 \cdot \left({cosTheta}^{3} \cdot \left(-1 \cdot \left(\sqrt{{\pi}^{3}} \cdot {\left(1 + \left(c + -1 \cdot \sqrt{\frac{1}{\pi}}\right)\right)}^{2}\right) + \pi \cdot \left(-1 \cdot \sqrt{\frac{1}{\pi}} + -0.5 \cdot \sqrt{\frac{1}{\pi}}\right)\right)\right) + \left(-1 \cdot \left({cosTheta}^{4} \cdot \left(-1 \cdot \left(\sqrt{\pi} \cdot \left(\left(1 + \left(c + -1 \cdot \sqrt{\frac{1}{\pi}}\right)\right) \cdot \left(-1 \cdot \left(\sqrt{{\pi}^{3}} \cdot {\left(1 + \left(c + -1 \cdot \sqrt{\frac{1}{\pi}}\right)\right)}^{2}\right) + \pi \cdot \left(-1 \cdot \sqrt{\frac{1}{\pi}} + -0.5 \cdot \sqrt{\frac{1}{\pi}}\right)\right)\right)\right) + \left(-1 \cdot \left(\sqrt{{\pi}^{3}} \cdot \left(\left(1 + \left(c + -1 \cdot \sqrt{\frac{1}{\pi}}\right)\right) \cdot \left(-1 \cdot \sqrt{\frac{1}{\pi}} + -0.5 \cdot \sqrt{\frac{1}{\pi}}\right)\right)\right) + \pi \cdot \left(\sqrt{\frac{1}{\pi}} + -0.5 \cdot \sqrt{\frac{1}{\pi}}\right)\right)\right)\right) + cosTheta \cdot \sqrt{\pi}\right)\right)} \]
  5. Simplified97.8%

    \[\leadsto \color{blue}{\left(\left(cosTheta \cdot \sqrt{\pi} - {cosTheta}^{4} \cdot \left(\left(0.5 \cdot \left(\pi \cdot \sqrt{\frac{1}{\pi}}\right) - \left(1 + \left(c - \sqrt{\frac{1}{\pi}}\right)\right) \cdot \left(\left(\sqrt{\frac{1}{\pi}} \cdot -1.5\right) \cdot \sqrt{{\pi}^{3}}\right)\right) - \mathsf{fma}\left(\pi, \sqrt{\frac{1}{\pi}} \cdot -1.5, {\left(1 + \left(c - \sqrt{\frac{1}{\pi}}\right)\right)}^{2} \cdot \left(-\sqrt{{\pi}^{3}}\right)\right) \cdot \left(\sqrt{\pi} \cdot \left(1 + \left(c - \sqrt{\frac{1}{\pi}}\right)\right)\right)\right)\right) - {cosTheta}^{3} \cdot \mathsf{fma}\left(\pi, \sqrt{\frac{1}{\pi}} \cdot -1.5, {\left(1 + \left(c - \sqrt{\frac{1}{\pi}}\right)\right)}^{2} \cdot \left(-\sqrt{{\pi}^{3}}\right)\right)\right) - \pi \cdot \left(\left(1 + \left(c - \sqrt{\frac{1}{\pi}}\right)\right) \cdot {cosTheta}^{2}\right)} \]
  6. Final simplification97.8%

    \[\leadsto \left(\left(cosTheta \cdot \sqrt{\pi} + {cosTheta}^{4} \cdot \left(\mathsf{fma}\left(\pi, \sqrt{\frac{1}{\pi}} \cdot -1.5, {\left(1 - \left(\sqrt{\frac{1}{\pi}} - c\right)\right)}^{2} \cdot \left(-\sqrt{{\pi}^{3}}\right)\right) \cdot \left(\sqrt{\pi} \cdot \left(1 - \left(\sqrt{\frac{1}{\pi}} - c\right)\right)\right) + \left(\left(1 - \left(\sqrt{\frac{1}{\pi}} - c\right)\right) \cdot \left(\left(\sqrt{\frac{1}{\pi}} \cdot -1.5\right) \cdot \sqrt{{\pi}^{3}}\right) - 0.5 \cdot \left(\pi \cdot \sqrt{\frac{1}{\pi}}\right)\right)\right)\right) - \mathsf{fma}\left(\pi, \sqrt{\frac{1}{\pi}} \cdot -1.5, {\left(1 - \left(\sqrt{\frac{1}{\pi}} - c\right)\right)}^{2} \cdot \left(-\sqrt{{\pi}^{3}}\right)\right) \cdot {cosTheta}^{3}\right) + \pi \cdot \left({cosTheta}^{2} \cdot \left(-1 + \left(\sqrt{\frac{1}{\pi}} - c\right)\right)\right) \]

Alternative 2: 98.5% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \frac{1}{c + \left(1 + \frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta \cdot \sqrt{\pi}}}{{\left(e^{cosTheta}\right)}^{cosTheta}}\right)} \end{array} \]
(FPCore (cosTheta c)
 :precision binary32
 (/
  1.0
  (+
   c
   (+
    1.0
    (/
     (/ (sqrt (+ 1.0 (* cosTheta -2.0))) (* cosTheta (sqrt PI)))
     (pow (exp cosTheta) cosTheta))))))
float code(float cosTheta, float c) {
	return 1.0f / (c + (1.0f + ((sqrtf((1.0f + (cosTheta * -2.0f))) / (cosTheta * sqrtf(((float) M_PI)))) / powf(expf(cosTheta), cosTheta))));
}
function code(cosTheta, c)
	return Float32(Float32(1.0) / Float32(c + Float32(Float32(1.0) + Float32(Float32(sqrt(Float32(Float32(1.0) + Float32(cosTheta * Float32(-2.0)))) / Float32(cosTheta * sqrt(Float32(pi)))) / (exp(cosTheta) ^ cosTheta)))))
end
function tmp = code(cosTheta, c)
	tmp = single(1.0) / (c + (single(1.0) + ((sqrt((single(1.0) + (cosTheta * single(-2.0)))) / (cosTheta * sqrt(single(pi)))) / (exp(cosTheta) ^ cosTheta))));
end
\begin{array}{l}

\\
\frac{1}{c + \left(1 + \frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta \cdot \sqrt{\pi}}}{{\left(e^{cosTheta}\right)}^{cosTheta}}\right)}
\end{array}
Derivation
  1. Initial program 96.9%

    \[\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  2. Step-by-step derivation
    1. +-commutative96.9%

      \[\leadsto \frac{1}{\color{blue}{\left(c + 1\right)} + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    2. associate-+l+96.9%

      \[\leadsto \frac{1}{\color{blue}{c + \left(1 + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)}} \]
    3. *-commutative96.9%

      \[\leadsto \frac{1}{c + \left(1 + \color{blue}{\left(\frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{1}{\sqrt{\pi}}\right)} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)} \]
    4. associate-*l*96.9%

      \[\leadsto \frac{1}{c + \left(1 + \color{blue}{\frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \left(\frac{1}{\sqrt{\pi}} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)}\right)} \]
    5. /-rgt-identity96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \left(\color{blue}{\frac{\frac{1}{\sqrt{\pi}}}{1}} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)\right)} \]
    6. associate-/r/96.8%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \color{blue}{\frac{\frac{1}{\sqrt{\pi}}}{\frac{1}{e^{\left(-cosTheta\right) \cdot cosTheta}}}}\right)} \]
    7. exp-neg96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{\frac{1}{\sqrt{\pi}}}{\color{blue}{e^{-\left(-cosTheta\right) \cdot cosTheta}}}\right)} \]
    8. distribute-rgt-neg-out96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{\frac{1}{\sqrt{\pi}}}{e^{\color{blue}{\left(-cosTheta\right) \cdot \left(-cosTheta\right)}}}\right)} \]
  3. Simplified97.7%

    \[\leadsto \color{blue}{\frac{1}{c + \left(1 + \frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{\sqrt{\pi} \cdot cosTheta}}{{\left(e^{cosTheta}\right)}^{cosTheta}}\right)}} \]
  4. Final simplification97.7%

    \[\leadsto \frac{1}{c + \left(1 + \frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta \cdot \sqrt{\pi}}}{{\left(e^{cosTheta}\right)}^{cosTheta}}\right)} \]

Alternative 3: 97.7% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \frac{1}{1 + \frac{\sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}}{cosTheta \cdot e^{{cosTheta}^{2}}}} \end{array} \]
(FPCore (cosTheta c)
 :precision binary32
 (/
  1.0
  (+
   1.0
   (/
    (sqrt (/ (fma cosTheta -2.0 1.0) PI))
    (* cosTheta (exp (pow cosTheta 2.0)))))))
float code(float cosTheta, float c) {
	return 1.0f / (1.0f + (sqrtf((fmaf(cosTheta, -2.0f, 1.0f) / ((float) M_PI))) / (cosTheta * expf(powf(cosTheta, 2.0f)))));
}
function code(cosTheta, c)
	return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(sqrt(Float32(fma(cosTheta, Float32(-2.0), Float32(1.0)) / Float32(pi))) / Float32(cosTheta * exp((cosTheta ^ Float32(2.0)))))))
end
\begin{array}{l}

\\
\frac{1}{1 + \frac{\sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}}{cosTheta \cdot e^{{cosTheta}^{2}}}}
\end{array}
Derivation
  1. Initial program 96.9%

    \[\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  2. Step-by-step derivation
    1. +-commutative96.9%

      \[\leadsto \frac{1}{\color{blue}{\left(c + 1\right)} + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    2. associate-+l+96.9%

      \[\leadsto \frac{1}{\color{blue}{c + \left(1 + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)}} \]
    3. *-commutative96.9%

      \[\leadsto \frac{1}{c + \left(1 + \color{blue}{\left(\frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{1}{\sqrt{\pi}}\right)} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)} \]
    4. associate-*l*96.9%

      \[\leadsto \frac{1}{c + \left(1 + \color{blue}{\frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \left(\frac{1}{\sqrt{\pi}} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)}\right)} \]
    5. /-rgt-identity96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \left(\color{blue}{\frac{\frac{1}{\sqrt{\pi}}}{1}} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)\right)} \]
    6. associate-/r/96.8%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \color{blue}{\frac{\frac{1}{\sqrt{\pi}}}{\frac{1}{e^{\left(-cosTheta\right) \cdot cosTheta}}}}\right)} \]
    7. exp-neg96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{\frac{1}{\sqrt{\pi}}}{\color{blue}{e^{-\left(-cosTheta\right) \cdot cosTheta}}}\right)} \]
    8. distribute-rgt-neg-out96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{\frac{1}{\sqrt{\pi}}}{e^{\color{blue}{\left(-cosTheta\right) \cdot \left(-cosTheta\right)}}}\right)} \]
  3. Simplified97.7%

    \[\leadsto \color{blue}{\frac{1}{c + \left(1 + \frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{\sqrt{\pi} \cdot cosTheta}}{{\left(e^{cosTheta}\right)}^{cosTheta}}\right)}} \]
  4. Taylor expanded in c around 0 96.8%

    \[\leadsto \color{blue}{\frac{1}{1 + \frac{1}{cosTheta \cdot e^{{cosTheta}^{2}}} \cdot \sqrt{\frac{1 + -2 \cdot cosTheta}{\pi}}}} \]
  5. Step-by-step derivation
    1. +-commutative96.8%

      \[\leadsto \frac{1}{1 + \frac{1}{cosTheta \cdot e^{{cosTheta}^{2}}} \cdot \sqrt{\frac{\color{blue}{-2 \cdot cosTheta + 1}}{\pi}}} \]
    2. *-commutative96.8%

      \[\leadsto \frac{1}{1 + \frac{1}{cosTheta \cdot e^{{cosTheta}^{2}}} \cdot \sqrt{\frac{\color{blue}{cosTheta \cdot -2} + 1}{\pi}}} \]
    3. fma-udef96.8%

      \[\leadsto \frac{1}{1 + \frac{1}{cosTheta \cdot e^{{cosTheta}^{2}}} \cdot \sqrt{\frac{\color{blue}{\mathsf{fma}\left(cosTheta, -2, 1\right)}}{\pi}}} \]
    4. associate-*l/97.2%

      \[\leadsto \frac{1}{1 + \color{blue}{\frac{1 \cdot \sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}}{cosTheta \cdot e^{{cosTheta}^{2}}}}} \]
    5. *-lft-identity97.2%

      \[\leadsto \frac{1}{1 + \frac{\color{blue}{\sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}}}{cosTheta \cdot e^{{cosTheta}^{2}}}} \]
  6. Simplified97.2%

    \[\leadsto \color{blue}{\frac{1}{1 + \frac{\sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}}{cosTheta \cdot e^{{cosTheta}^{2}}}}} \]
  7. Final simplification97.2%

    \[\leadsto \frac{1}{1 + \frac{\sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}}{cosTheta \cdot e^{{cosTheta}^{2}}}} \]

Alternative 4: 97.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{1}{1 + \left(c + \frac{e^{-{cosTheta}^{2}}}{cosTheta} \cdot \sqrt{\frac{1 + cosTheta \cdot -2}{\pi}}\right)} \end{array} \]
(FPCore (cosTheta c)
 :precision binary32
 (/
  1.0
  (+
   1.0
   (+
    c
    (*
     (/ (exp (- (pow cosTheta 2.0))) cosTheta)
     (sqrt (/ (+ 1.0 (* cosTheta -2.0)) PI)))))))
float code(float cosTheta, float c) {
	return 1.0f / (1.0f + (c + ((expf(-powf(cosTheta, 2.0f)) / cosTheta) * sqrtf(((1.0f + (cosTheta * -2.0f)) / ((float) M_PI))))));
}
function code(cosTheta, c)
	return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(Float32(exp(Float32(-(cosTheta ^ Float32(2.0)))) / cosTheta) * sqrt(Float32(Float32(Float32(1.0) + Float32(cosTheta * Float32(-2.0))) / Float32(pi)))))))
end
function tmp = code(cosTheta, c)
	tmp = single(1.0) / (single(1.0) + (c + ((exp(-(cosTheta ^ single(2.0))) / cosTheta) * sqrt(((single(1.0) + (cosTheta * single(-2.0))) / single(pi))))));
end
\begin{array}{l}

\\
\frac{1}{1 + \left(c + \frac{e^{-{cosTheta}^{2}}}{cosTheta} \cdot \sqrt{\frac{1 + cosTheta \cdot -2}{\pi}}\right)}
\end{array}
Derivation
  1. Initial program 96.9%

    \[\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  2. Step-by-step derivation
    1. +-commutative96.9%

      \[\leadsto \frac{1}{\color{blue}{\left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta} + \left(1 + c\right)}} \]
    2. fma-def96.9%

      \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)}} \]
  3. Simplified97.4%

    \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)}} \]
  4. Taylor expanded in c around 0 97.0%

    \[\leadsto \frac{1}{\color{blue}{1 + \left(c + \frac{e^{-1 \cdot {cosTheta}^{2}}}{cosTheta} \cdot \sqrt{\frac{1 + -2 \cdot cosTheta}{\pi}}\right)}} \]
  5. Final simplification97.0%

    \[\leadsto \frac{1}{1 + \left(c + \frac{e^{-{cosTheta}^{2}}}{cosTheta} \cdot \sqrt{\frac{1 + cosTheta \cdot -2}{\pi}}\right)} \]

Alternative 5: 97.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{1}{1 + \sqrt{\frac{1 + cosTheta \cdot -2}{\pi}} \cdot \frac{1}{cosTheta \cdot e^{{cosTheta}^{2}}}} \end{array} \]
(FPCore (cosTheta c)
 :precision binary32
 (/
  1.0
  (+
   1.0
   (*
    (sqrt (/ (+ 1.0 (* cosTheta -2.0)) PI))
    (/ 1.0 (* cosTheta (exp (pow cosTheta 2.0))))))))
float code(float cosTheta, float c) {
	return 1.0f / (1.0f + (sqrtf(((1.0f + (cosTheta * -2.0f)) / ((float) M_PI))) * (1.0f / (cosTheta * expf(powf(cosTheta, 2.0f))))));
}
function code(cosTheta, c)
	return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(sqrt(Float32(Float32(Float32(1.0) + Float32(cosTheta * Float32(-2.0))) / Float32(pi))) * Float32(Float32(1.0) / Float32(cosTheta * exp((cosTheta ^ Float32(2.0))))))))
end
function tmp = code(cosTheta, c)
	tmp = single(1.0) / (single(1.0) + (sqrt(((single(1.0) + (cosTheta * single(-2.0))) / single(pi))) * (single(1.0) / (cosTheta * exp((cosTheta ^ single(2.0)))))));
end
\begin{array}{l}

\\
\frac{1}{1 + \sqrt{\frac{1 + cosTheta \cdot -2}{\pi}} \cdot \frac{1}{cosTheta \cdot e^{{cosTheta}^{2}}}}
\end{array}
Derivation
  1. Initial program 96.9%

    \[\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  2. Step-by-step derivation
    1. +-commutative96.9%

      \[\leadsto \frac{1}{\color{blue}{\left(c + 1\right)} + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    2. associate-+l+96.9%

      \[\leadsto \frac{1}{\color{blue}{c + \left(1 + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)}} \]
    3. *-commutative96.9%

      \[\leadsto \frac{1}{c + \left(1 + \color{blue}{\left(\frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{1}{\sqrt{\pi}}\right)} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)} \]
    4. associate-*l*96.9%

      \[\leadsto \frac{1}{c + \left(1 + \color{blue}{\frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \left(\frac{1}{\sqrt{\pi}} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)}\right)} \]
    5. /-rgt-identity96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \left(\color{blue}{\frac{\frac{1}{\sqrt{\pi}}}{1}} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)\right)} \]
    6. associate-/r/96.8%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \color{blue}{\frac{\frac{1}{\sqrt{\pi}}}{\frac{1}{e^{\left(-cosTheta\right) \cdot cosTheta}}}}\right)} \]
    7. exp-neg96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{\frac{1}{\sqrt{\pi}}}{\color{blue}{e^{-\left(-cosTheta\right) \cdot cosTheta}}}\right)} \]
    8. distribute-rgt-neg-out96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{\frac{1}{\sqrt{\pi}}}{e^{\color{blue}{\left(-cosTheta\right) \cdot \left(-cosTheta\right)}}}\right)} \]
  3. Simplified97.7%

    \[\leadsto \color{blue}{\frac{1}{c + \left(1 + \frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{\sqrt{\pi} \cdot cosTheta}}{{\left(e^{cosTheta}\right)}^{cosTheta}}\right)}} \]
  4. Taylor expanded in c around 0 96.8%

    \[\leadsto \color{blue}{\frac{1}{1 + \frac{1}{cosTheta \cdot e^{{cosTheta}^{2}}} \cdot \sqrt{\frac{1 + -2 \cdot cosTheta}{\pi}}}} \]
  5. Final simplification96.8%

    \[\leadsto \frac{1}{1 + \sqrt{\frac{1 + cosTheta \cdot -2}{\pi}} \cdot \frac{1}{cosTheta \cdot e^{{cosTheta}^{2}}}} \]

Alternative 6: 95.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{1}{c + \left(1 + \frac{\frac{1 - cosTheta}{cosTheta \cdot \sqrt{\pi}}}{{\left(e^{cosTheta}\right)}^{cosTheta}}\right)} \end{array} \]
(FPCore (cosTheta c)
 :precision binary32
 (/
  1.0
  (+
   c
   (+
    1.0
    (/
     (/ (- 1.0 cosTheta) (* cosTheta (sqrt PI)))
     (pow (exp cosTheta) cosTheta))))))
float code(float cosTheta, float c) {
	return 1.0f / (c + (1.0f + (((1.0f - cosTheta) / (cosTheta * sqrtf(((float) M_PI)))) / powf(expf(cosTheta), cosTheta))));
}
function code(cosTheta, c)
	return Float32(Float32(1.0) / Float32(c + Float32(Float32(1.0) + Float32(Float32(Float32(Float32(1.0) - cosTheta) / Float32(cosTheta * sqrt(Float32(pi)))) / (exp(cosTheta) ^ cosTheta)))))
end
function tmp = code(cosTheta, c)
	tmp = single(1.0) / (c + (single(1.0) + (((single(1.0) - cosTheta) / (cosTheta * sqrt(single(pi)))) / (exp(cosTheta) ^ cosTheta))));
end
\begin{array}{l}

\\
\frac{1}{c + \left(1 + \frac{\frac{1 - cosTheta}{cosTheta \cdot \sqrt{\pi}}}{{\left(e^{cosTheta}\right)}^{cosTheta}}\right)}
\end{array}
Derivation
  1. Initial program 96.9%

    \[\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  2. Step-by-step derivation
    1. +-commutative96.9%

      \[\leadsto \frac{1}{\color{blue}{\left(c + 1\right)} + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    2. associate-+l+96.9%

      \[\leadsto \frac{1}{\color{blue}{c + \left(1 + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)}} \]
    3. *-commutative96.9%

      \[\leadsto \frac{1}{c + \left(1 + \color{blue}{\left(\frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{1}{\sqrt{\pi}}\right)} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)} \]
    4. associate-*l*96.9%

      \[\leadsto \frac{1}{c + \left(1 + \color{blue}{\frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \left(\frac{1}{\sqrt{\pi}} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)}\right)} \]
    5. /-rgt-identity96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \left(\color{blue}{\frac{\frac{1}{\sqrt{\pi}}}{1}} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)\right)} \]
    6. associate-/r/96.8%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \color{blue}{\frac{\frac{1}{\sqrt{\pi}}}{\frac{1}{e^{\left(-cosTheta\right) \cdot cosTheta}}}}\right)} \]
    7. exp-neg96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{\frac{1}{\sqrt{\pi}}}{\color{blue}{e^{-\left(-cosTheta\right) \cdot cosTheta}}}\right)} \]
    8. distribute-rgt-neg-out96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{\frac{1}{\sqrt{\pi}}}{e^{\color{blue}{\left(-cosTheta\right) \cdot \left(-cosTheta\right)}}}\right)} \]
  3. Simplified97.7%

    \[\leadsto \color{blue}{\frac{1}{c + \left(1 + \frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{\sqrt{\pi} \cdot cosTheta}}{{\left(e^{cosTheta}\right)}^{cosTheta}}\right)}} \]
  4. Taylor expanded in cosTheta around 0 95.4%

    \[\leadsto \frac{1}{c + \left(1 + \frac{\frac{\color{blue}{1 + -1 \cdot cosTheta}}{\sqrt{\pi} \cdot cosTheta}}{{\left(e^{cosTheta}\right)}^{cosTheta}}\right)} \]
  5. Step-by-step derivation
    1. mul-1-neg95.4%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\frac{1 + \color{blue}{\left(-cosTheta\right)}}{\sqrt{\pi} \cdot cosTheta}}{{\left(e^{cosTheta}\right)}^{cosTheta}}\right)} \]
    2. unsub-neg95.4%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\frac{\color{blue}{1 - cosTheta}}{\sqrt{\pi} \cdot cosTheta}}{{\left(e^{cosTheta}\right)}^{cosTheta}}\right)} \]
  6. Simplified95.4%

    \[\leadsto \frac{1}{c + \left(1 + \frac{\frac{\color{blue}{1 - cosTheta}}{\sqrt{\pi} \cdot cosTheta}}{{\left(e^{cosTheta}\right)}^{cosTheta}}\right)} \]
  7. Final simplification95.4%

    \[\leadsto \frac{1}{c + \left(1 + \frac{\frac{1 - cosTheta}{cosTheta \cdot \sqrt{\pi}}}{{\left(e^{cosTheta}\right)}^{cosTheta}}\right)} \]

Alternative 7: 95.1% accurate, 1.3× speedup?

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

\\
\frac{1}{c + \left(1 + \left(\sqrt{\frac{1}{\pi}} \cdot \left(1 - {cosTheta}^{2}\right)\right) \cdot \left(-1 + \frac{1}{cosTheta}\right)\right)}
\end{array}
Derivation
  1. Initial program 96.9%

    \[\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  2. Step-by-step derivation
    1. +-commutative96.9%

      \[\leadsto \frac{1}{\color{blue}{\left(c + 1\right)} + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    2. associate-+l+96.9%

      \[\leadsto \frac{1}{\color{blue}{c + \left(1 + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)}} \]
    3. *-commutative96.9%

      \[\leadsto \frac{1}{c + \left(1 + \color{blue}{\left(\frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{1}{\sqrt{\pi}}\right)} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)} \]
    4. associate-*l*96.9%

      \[\leadsto \frac{1}{c + \left(1 + \color{blue}{\frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \left(\frac{1}{\sqrt{\pi}} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)}\right)} \]
    5. /-rgt-identity96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \left(\color{blue}{\frac{\frac{1}{\sqrt{\pi}}}{1}} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)\right)} \]
    6. associate-/r/96.8%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \color{blue}{\frac{\frac{1}{\sqrt{\pi}}}{\frac{1}{e^{\left(-cosTheta\right) \cdot cosTheta}}}}\right)} \]
    7. exp-neg96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{\frac{1}{\sqrt{\pi}}}{\color{blue}{e^{-\left(-cosTheta\right) \cdot cosTheta}}}\right)} \]
    8. distribute-rgt-neg-out96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{\frac{1}{\sqrt{\pi}}}{e^{\color{blue}{\left(-cosTheta\right) \cdot \left(-cosTheta\right)}}}\right)} \]
  3. Simplified97.7%

    \[\leadsto \color{blue}{\frac{1}{c + \left(1 + \frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{\sqrt{\pi} \cdot cosTheta}}{{\left(e^{cosTheta}\right)}^{cosTheta}}\right)}} \]
  4. Taylor expanded in cosTheta around 0 94.6%

    \[\leadsto \frac{1}{c + \left(1 + \frac{\color{blue}{-1 \cdot \sqrt{\frac{1}{\pi}} + \frac{1}{cosTheta} \cdot \sqrt{\frac{1}{\pi}}}}{{\left(e^{cosTheta}\right)}^{cosTheta}}\right)} \]
  5. Step-by-step derivation
    1. distribute-rgt-out94.6%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\color{blue}{\sqrt{\frac{1}{\pi}} \cdot \left(-1 + \frac{1}{cosTheta}\right)}}{{\left(e^{cosTheta}\right)}^{cosTheta}}\right)} \]
  6. Simplified94.6%

    \[\leadsto \frac{1}{c + \left(1 + \frac{\color{blue}{\sqrt{\frac{1}{\pi}} \cdot \left(-1 + \frac{1}{cosTheta}\right)}}{{\left(e^{cosTheta}\right)}^{cosTheta}}\right)} \]
  7. Step-by-step derivation
    1. *-un-lft-identity94.6%

      \[\leadsto \frac{1}{c + \left(1 + \color{blue}{1 \cdot \frac{\sqrt{\frac{1}{\pi}} \cdot \left(-1 + \frac{1}{cosTheta}\right)}{{\left(e^{cosTheta}\right)}^{cosTheta}}}\right)} \]
    2. associate-/l*94.4%

      \[\leadsto \frac{1}{c + \left(1 + 1 \cdot \color{blue}{\frac{\sqrt{\frac{1}{\pi}}}{\frac{{\left(e^{cosTheta}\right)}^{cosTheta}}{-1 + \frac{1}{cosTheta}}}}\right)} \]
    3. pow1/294.4%

      \[\leadsto \frac{1}{c + \left(1 + 1 \cdot \frac{\color{blue}{{\left(\frac{1}{\pi}\right)}^{0.5}}}{\frac{{\left(e^{cosTheta}\right)}^{cosTheta}}{-1 + \frac{1}{cosTheta}}}\right)} \]
    4. inv-pow94.4%

      \[\leadsto \frac{1}{c + \left(1 + 1 \cdot \frac{{\color{blue}{\left({\pi}^{-1}\right)}}^{0.5}}{\frac{{\left(e^{cosTheta}\right)}^{cosTheta}}{-1 + \frac{1}{cosTheta}}}\right)} \]
    5. pow-pow94.4%

      \[\leadsto \frac{1}{c + \left(1 + 1 \cdot \frac{\color{blue}{{\pi}^{\left(-1 \cdot 0.5\right)}}}{\frac{{\left(e^{cosTheta}\right)}^{cosTheta}}{-1 + \frac{1}{cosTheta}}}\right)} \]
    6. metadata-eval94.4%

      \[\leadsto \frac{1}{c + \left(1 + 1 \cdot \frac{{\pi}^{\color{blue}{-0.5}}}{\frac{{\left(e^{cosTheta}\right)}^{cosTheta}}{-1 + \frac{1}{cosTheta}}}\right)} \]
    7. pow-exp94.4%

      \[\leadsto \frac{1}{c + \left(1 + 1 \cdot \frac{{\pi}^{-0.5}}{\frac{\color{blue}{e^{cosTheta \cdot cosTheta}}}{-1 + \frac{1}{cosTheta}}}\right)} \]
    8. unpow294.4%

      \[\leadsto \frac{1}{c + \left(1 + 1 \cdot \frac{{\pi}^{-0.5}}{\frac{e^{\color{blue}{{cosTheta}^{2}}}}{-1 + \frac{1}{cosTheta}}}\right)} \]
  8. Applied egg-rr94.4%

    \[\leadsto \frac{1}{c + \left(1 + \color{blue}{1 \cdot \frac{{\pi}^{-0.5}}{\frac{e^{{cosTheta}^{2}}}{-1 + \frac{1}{cosTheta}}}}\right)} \]
  9. Step-by-step derivation
    1. *-lft-identity94.4%

      \[\leadsto \frac{1}{c + \left(1 + \color{blue}{\frac{{\pi}^{-0.5}}{\frac{e^{{cosTheta}^{2}}}{-1 + \frac{1}{cosTheta}}}}\right)} \]
    2. associate-/r/94.5%

      \[\leadsto \frac{1}{c + \left(1 + \color{blue}{\frac{{\pi}^{-0.5}}{e^{{cosTheta}^{2}}} \cdot \left(-1 + \frac{1}{cosTheta}\right)}\right)} \]
  10. Simplified94.5%

    \[\leadsto \frac{1}{c + \left(1 + \color{blue}{\frac{{\pi}^{-0.5}}{e^{{cosTheta}^{2}}} \cdot \left(-1 + \frac{1}{cosTheta}\right)}\right)} \]
  11. Taylor expanded in cosTheta around 0 94.5%

    \[\leadsto \frac{1}{c + \left(1 + \color{blue}{\left(\sqrt{\frac{1}{\pi}} + -1 \cdot \left({cosTheta}^{2} \cdot \sqrt{\frac{1}{\pi}}\right)\right)} \cdot \left(-1 + \frac{1}{cosTheta}\right)\right)} \]
  12. Step-by-step derivation
    1. associate-*r*94.5%

      \[\leadsto \frac{1}{c + \left(1 + \left(\sqrt{\frac{1}{\pi}} + \color{blue}{\left(-1 \cdot {cosTheta}^{2}\right) \cdot \sqrt{\frac{1}{\pi}}}\right) \cdot \left(-1 + \frac{1}{cosTheta}\right)\right)} \]
    2. neg-mul-194.5%

      \[\leadsto \frac{1}{c + \left(1 + \left(\sqrt{\frac{1}{\pi}} + \color{blue}{\left(-{cosTheta}^{2}\right)} \cdot \sqrt{\frac{1}{\pi}}\right) \cdot \left(-1 + \frac{1}{cosTheta}\right)\right)} \]
    3. distribute-rgt1-in94.5%

      \[\leadsto \frac{1}{c + \left(1 + \color{blue}{\left(\left(\left(-{cosTheta}^{2}\right) + 1\right) \cdot \sqrt{\frac{1}{\pi}}\right)} \cdot \left(-1 + \frac{1}{cosTheta}\right)\right)} \]
  13. Simplified94.5%

    \[\leadsto \frac{1}{c + \left(1 + \color{blue}{\left(\left(\left(-{cosTheta}^{2}\right) + 1\right) \cdot \sqrt{\frac{1}{\pi}}\right)} \cdot \left(-1 + \frac{1}{cosTheta}\right)\right)} \]
  14. Final simplification94.5%

    \[\leadsto \frac{1}{c + \left(1 + \left(\sqrt{\frac{1}{\pi}} \cdot \left(1 - {cosTheta}^{2}\right)\right) \cdot \left(-1 + \frac{1}{cosTheta}\right)\right)} \]

Alternative 8: 94.6% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \frac{1}{1 + \sqrt{\frac{1}{\pi}} \cdot \left(-1 + \frac{1}{cosTheta}\right)} \end{array} \]
(FPCore (cosTheta c)
 :precision binary32
 (/ 1.0 (+ 1.0 (* (sqrt (/ 1.0 PI)) (+ -1.0 (/ 1.0 cosTheta))))))
float code(float cosTheta, float c) {
	return 1.0f / (1.0f + (sqrtf((1.0f / ((float) M_PI))) * (-1.0f + (1.0f / cosTheta))));
}
function code(cosTheta, c)
	return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(sqrt(Float32(Float32(1.0) / Float32(pi))) * Float32(Float32(-1.0) + Float32(Float32(1.0) / cosTheta)))))
end
function tmp = code(cosTheta, c)
	tmp = single(1.0) / (single(1.0) + (sqrt((single(1.0) / single(pi))) * (single(-1.0) + (single(1.0) / cosTheta))));
end
\begin{array}{l}

\\
\frac{1}{1 + \sqrt{\frac{1}{\pi}} \cdot \left(-1 + \frac{1}{cosTheta}\right)}
\end{array}
Derivation
  1. Initial program 96.9%

    \[\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  2. Taylor expanded in c around 0 96.8%

    \[\leadsto \color{blue}{\frac{1}{1 + \frac{e^{-1 \cdot {cosTheta}^{2}}}{cosTheta} \cdot \sqrt{\frac{1 - 2 \cdot cosTheta}{\pi}}}} \]
  3. Taylor expanded in cosTheta around 0 94.1%

    \[\leadsto \frac{1}{1 + \color{blue}{\left(-1 \cdot \sqrt{\frac{1}{\pi}} + \frac{1}{cosTheta} \cdot \sqrt{\frac{1}{\pi}}\right)}} \]
  4. Step-by-step derivation
    1. distribute-rgt-out94.1%

      \[\leadsto \frac{1}{1 + \color{blue}{\sqrt{\frac{1}{\pi}} \cdot \left(-1 + \frac{1}{cosTheta}\right)}} \]
  5. Simplified94.1%

    \[\leadsto \frac{1}{1 + \color{blue}{\sqrt{\frac{1}{\pi}} \cdot \left(-1 + \frac{1}{cosTheta}\right)}} \]
  6. Final simplification94.1%

    \[\leadsto \frac{1}{1 + \sqrt{\frac{1}{\pi}} \cdot \left(-1 + \frac{1}{cosTheta}\right)} \]

Alternative 9: 94.7% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \frac{1}{1 + \frac{\sqrt{\frac{1}{\pi}} \cdot \left(1 - cosTheta\right)}{cosTheta}} \end{array} \]
(FPCore (cosTheta c)
 :precision binary32
 (/ 1.0 (+ 1.0 (/ (* (sqrt (/ 1.0 PI)) (- 1.0 cosTheta)) cosTheta))))
float code(float cosTheta, float c) {
	return 1.0f / (1.0f + ((sqrtf((1.0f / ((float) M_PI))) * (1.0f - cosTheta)) / cosTheta));
}
function code(cosTheta, c)
	return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(Float32(sqrt(Float32(Float32(1.0) / Float32(pi))) * Float32(Float32(1.0) - cosTheta)) / cosTheta)))
end
function tmp = code(cosTheta, c)
	tmp = single(1.0) / (single(1.0) + ((sqrt((single(1.0) / single(pi))) * (single(1.0) - cosTheta)) / cosTheta));
end
\begin{array}{l}

\\
\frac{1}{1 + \frac{\sqrt{\frac{1}{\pi}} \cdot \left(1 - cosTheta\right)}{cosTheta}}
\end{array}
Derivation
  1. Initial program 96.9%

    \[\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  2. Taylor expanded in c around 0 96.8%

    \[\leadsto \color{blue}{\frac{1}{1 + \frac{e^{-1 \cdot {cosTheta}^{2}}}{cosTheta} \cdot \sqrt{\frac{1 - 2 \cdot cosTheta}{\pi}}}} \]
  3. Step-by-step derivation
    1. associate-*l/97.2%

      \[\leadsto \frac{1}{1 + \color{blue}{\frac{e^{-1 \cdot {cosTheta}^{2}} \cdot \sqrt{\frac{1 - 2 \cdot cosTheta}{\pi}}}{cosTheta}}} \]
    2. mul-1-neg97.2%

      \[\leadsto \frac{1}{1 + \frac{e^{\color{blue}{-{cosTheta}^{2}}} \cdot \sqrt{\frac{1 - 2 \cdot cosTheta}{\pi}}}{cosTheta}} \]
    3. cancel-sign-sub-inv97.2%

      \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\frac{\color{blue}{1 + \left(-2\right) \cdot cosTheta}}{\pi}}}{cosTheta}} \]
    4. metadata-eval97.2%

      \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\frac{1 + \color{blue}{-2} \cdot cosTheta}{\pi}}}{cosTheta}} \]
    5. *-commutative97.2%

      \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\frac{1 + \color{blue}{cosTheta \cdot -2}}{\pi}}}{cosTheta}} \]
    6. +-commutative97.2%

      \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\frac{\color{blue}{cosTheta \cdot -2 + 1}}{\pi}}}{cosTheta}} \]
    7. fma-def97.2%

      \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\frac{\color{blue}{\mathsf{fma}\left(cosTheta, -2, 1\right)}}{\pi}}}{cosTheta}} \]
  4. Applied egg-rr97.2%

    \[\leadsto \frac{1}{1 + \color{blue}{\frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}}{cosTheta}}} \]
  5. Taylor expanded in cosTheta around 0 94.5%

    \[\leadsto \frac{1}{1 + \frac{\color{blue}{\sqrt{\frac{1}{\pi}} + -1 \cdot \left(cosTheta \cdot \sqrt{\frac{1}{\pi}}\right)}}{cosTheta}} \]
  6. Step-by-step derivation
    1. associate-*r*94.5%

      \[\leadsto \frac{1}{1 + \frac{\sqrt{\frac{1}{\pi}} + \color{blue}{\left(-1 \cdot cosTheta\right) \cdot \sqrt{\frac{1}{\pi}}}}{cosTheta}} \]
    2. distribute-rgt1-in94.5%

      \[\leadsto \frac{1}{1 + \frac{\color{blue}{\left(-1 \cdot cosTheta + 1\right) \cdot \sqrt{\frac{1}{\pi}}}}{cosTheta}} \]
    3. mul-1-neg94.5%

      \[\leadsto \frac{1}{1 + \frac{\left(\color{blue}{\left(-cosTheta\right)} + 1\right) \cdot \sqrt{\frac{1}{\pi}}}{cosTheta}} \]
  7. Simplified94.5%

    \[\leadsto \frac{1}{1 + \frac{\color{blue}{\left(\left(-cosTheta\right) + 1\right) \cdot \sqrt{\frac{1}{\pi}}}}{cosTheta}} \]
  8. Final simplification94.5%

    \[\leadsto \frac{1}{1 + \frac{\sqrt{\frac{1}{\pi}} \cdot \left(1 - cosTheta\right)}{cosTheta}} \]

Alternative 10: 92.5% accurate, 2.1× speedup?

\[\begin{array}{l} \\ cosTheta \cdot \sqrt{\pi} \end{array} \]
(FPCore (cosTheta c) :precision binary32 (* cosTheta (sqrt PI)))
float code(float cosTheta, float c) {
	return cosTheta * sqrtf(((float) M_PI));
}
function code(cosTheta, c)
	return Float32(cosTheta * sqrt(Float32(pi)))
end
function tmp = code(cosTheta, c)
	tmp = cosTheta * sqrt(single(pi));
end
\begin{array}{l}

\\
cosTheta \cdot \sqrt{\pi}
\end{array}
Derivation
  1. Initial program 96.9%

    \[\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  2. Step-by-step derivation
    1. +-commutative96.9%

      \[\leadsto \frac{1}{\color{blue}{\left(c + 1\right)} + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    2. associate-+l+96.9%

      \[\leadsto \frac{1}{\color{blue}{c + \left(1 + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)}} \]
    3. *-commutative96.9%

      \[\leadsto \frac{1}{c + \left(1 + \color{blue}{\left(\frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{1}{\sqrt{\pi}}\right)} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)} \]
    4. associate-*l*96.9%

      \[\leadsto \frac{1}{c + \left(1 + \color{blue}{\frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \left(\frac{1}{\sqrt{\pi}} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)}\right)} \]
    5. /-rgt-identity96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \left(\color{blue}{\frac{\frac{1}{\sqrt{\pi}}}{1}} \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)\right)} \]
    6. associate-/r/96.8%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \color{blue}{\frac{\frac{1}{\sqrt{\pi}}}{\frac{1}{e^{\left(-cosTheta\right) \cdot cosTheta}}}}\right)} \]
    7. exp-neg96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{\frac{1}{\sqrt{\pi}}}{\color{blue}{e^{-\left(-cosTheta\right) \cdot cosTheta}}}\right)} \]
    8. distribute-rgt-neg-out96.9%

      \[\leadsto \frac{1}{c + \left(1 + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta} \cdot \frac{\frac{1}{\sqrt{\pi}}}{e^{\color{blue}{\left(-cosTheta\right) \cdot \left(-cosTheta\right)}}}\right)} \]
  3. Simplified97.7%

    \[\leadsto \color{blue}{\frac{1}{c + \left(1 + \frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{\sqrt{\pi} \cdot cosTheta}}{{\left(e^{cosTheta}\right)}^{cosTheta}}\right)}} \]
  4. Taylor expanded in cosTheta around 0 92.3%

    \[\leadsto \color{blue}{cosTheta \cdot \sqrt{\pi}} \]
  5. Final simplification92.3%

    \[\leadsto cosTheta \cdot \sqrt{\pi} \]

Alternative 11: 10.9% accurate, 421.0× speedup?

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

\\
1
\end{array}
Derivation
  1. Initial program 96.9%

    \[\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  2. Taylor expanded in c around 0 96.8%

    \[\leadsto \color{blue}{\frac{1}{1 + \frac{e^{-1 \cdot {cosTheta}^{2}}}{cosTheta} \cdot \sqrt{\frac{1 - 2 \cdot cosTheta}{\pi}}}} \]
  3. Taylor expanded in cosTheta around inf 10.8%

    \[\leadsto \color{blue}{1} \]
  4. Final simplification10.8%

    \[\leadsto 1 \]

Reproduce

?
herbie shell --seed 2023310 
(FPCore (cosTheta c)
  :name "Beckmann Sample, normalization factor"
  :precision binary32
  :pre (and (and (< 0.0 cosTheta) (< cosTheta 0.9999)) (and (< -1.0 c) (< c 1.0)))
  (/ 1.0 (+ (+ 1.0 c) (* (* (/ 1.0 (sqrt PI)) (/ (sqrt (- (- 1.0 cosTheta) cosTheta)) cosTheta)) (exp (* (- cosTheta) cosTheta))))))