Trowbridge-Reitz Sample, sample surface normal, cosTheta

Percentage Accurate: 99.4% → 99.7%
Time: 14.4s
Alternatives: 7
Speedup: 1.7×

Specification

?
\[\left(\left(\left(2.328306437 \cdot 10^{-10} \leq u0 \land u0 \leq 1\right) \land \left(2.328306437 \cdot 10^{-10} \leq u1 \land u1 \leq 0.5\right)\right) \land \left(0.0001 \leq alphax \land alphax \leq 1\right)\right) \land \left(0.0001 \leq alphay \land alphay \leq 1\right)\]
\[\begin{array}{l} t_0 := \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)\\ t_1 := \sin t\_0\\ t_2 := \cos t\_0\\ \frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{t\_2 \cdot t\_2}{alphax \cdot alphax} + \frac{t\_1 \cdot t\_1}{alphay \cdot alphay}} \cdot u0}{1 - u0}}} \end{array} \]
(FPCore (u0 u1 alphax alphay)
  :precision binary32
  (let* ((t_0
        (atan
         (*
          (/ alphay alphax)
          (tan (+ (* (* 2.0 PI) u1) (* 0.5 PI))))))
       (t_1 (sin t_0))
       (t_2 (cos t_0)))
  (/
   1.0
   (sqrt
    (+
     1.0
     (/
      (*
       (/
        1.0
        (+
         (/ (* t_2 t_2) (* alphax alphax))
         (/ (* t_1 t_1) (* alphay alphay))))
       u0)
      (- 1.0 u0)))))))
float code(float u0, float u1, float alphax, float alphay) {
	float t_0 = atanf(((alphay / alphax) * tanf((((2.0f * ((float) M_PI)) * u1) + (0.5f * ((float) M_PI))))));
	float t_1 = sinf(t_0);
	float t_2 = cosf(t_0);
	return 1.0f / sqrtf((1.0f + (((1.0f / (((t_2 * t_2) / (alphax * alphax)) + ((t_1 * t_1) / (alphay * alphay)))) * u0) / (1.0f - u0))));
}
function code(u0, u1, alphax, alphay)
	t_0 = atan(Float32(Float32(alphay / alphax) * tan(Float32(Float32(Float32(Float32(2.0) * Float32(pi)) * u1) + Float32(Float32(0.5) * Float32(pi))))))
	t_1 = sin(t_0)
	t_2 = cos(t_0)
	return Float32(Float32(1.0) / sqrt(Float32(Float32(1.0) + Float32(Float32(Float32(Float32(1.0) / Float32(Float32(Float32(t_2 * t_2) / Float32(alphax * alphax)) + Float32(Float32(t_1 * t_1) / Float32(alphay * alphay)))) * u0) / Float32(Float32(1.0) - u0)))))
end
function tmp = code(u0, u1, alphax, alphay)
	t_0 = atan(((alphay / alphax) * tan((((single(2.0) * single(pi)) * u1) + (single(0.5) * single(pi))))));
	t_1 = sin(t_0);
	t_2 = cos(t_0);
	tmp = single(1.0) / sqrt((single(1.0) + (((single(1.0) / (((t_2 * t_2) / (alphax * alphax)) + ((t_1 * t_1) / (alphay * alphay)))) * u0) / (single(1.0) - u0))));
end
\begin{array}{l}
t_0 := \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)\\
t_1 := \sin t\_0\\
t_2 := \cos t\_0\\
\frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{t\_2 \cdot t\_2}{alphax \cdot alphax} + \frac{t\_1 \cdot t\_1}{alphay \cdot alphay}} \cdot u0}{1 - u0}}}
\end{array}

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 7 alternatives:

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

Initial Program: 99.4% accurate, 1.0× speedup?

\[\begin{array}{l} t_0 := \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)\\ t_1 := \sin t\_0\\ t_2 := \cos t\_0\\ \frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{t\_2 \cdot t\_2}{alphax \cdot alphax} + \frac{t\_1 \cdot t\_1}{alphay \cdot alphay}} \cdot u0}{1 - u0}}} \end{array} \]
(FPCore (u0 u1 alphax alphay)
  :precision binary32
  (let* ((t_0
        (atan
         (*
          (/ alphay alphax)
          (tan (+ (* (* 2.0 PI) u1) (* 0.5 PI))))))
       (t_1 (sin t_0))
       (t_2 (cos t_0)))
  (/
   1.0
   (sqrt
    (+
     1.0
     (/
      (*
       (/
        1.0
        (+
         (/ (* t_2 t_2) (* alphax alphax))
         (/ (* t_1 t_1) (* alphay alphay))))
       u0)
      (- 1.0 u0)))))))
float code(float u0, float u1, float alphax, float alphay) {
	float t_0 = atanf(((alphay / alphax) * tanf((((2.0f * ((float) M_PI)) * u1) + (0.5f * ((float) M_PI))))));
	float t_1 = sinf(t_0);
	float t_2 = cosf(t_0);
	return 1.0f / sqrtf((1.0f + (((1.0f / (((t_2 * t_2) / (alphax * alphax)) + ((t_1 * t_1) / (alphay * alphay)))) * u0) / (1.0f - u0))));
}
function code(u0, u1, alphax, alphay)
	t_0 = atan(Float32(Float32(alphay / alphax) * tan(Float32(Float32(Float32(Float32(2.0) * Float32(pi)) * u1) + Float32(Float32(0.5) * Float32(pi))))))
	t_1 = sin(t_0)
	t_2 = cos(t_0)
	return Float32(Float32(1.0) / sqrt(Float32(Float32(1.0) + Float32(Float32(Float32(Float32(1.0) / Float32(Float32(Float32(t_2 * t_2) / Float32(alphax * alphax)) + Float32(Float32(t_1 * t_1) / Float32(alphay * alphay)))) * u0) / Float32(Float32(1.0) - u0)))))
end
function tmp = code(u0, u1, alphax, alphay)
	t_0 = atan(((alphay / alphax) * tan((((single(2.0) * single(pi)) * u1) + (single(0.5) * single(pi))))));
	t_1 = sin(t_0);
	t_2 = cos(t_0);
	tmp = single(1.0) / sqrt((single(1.0) + (((single(1.0) / (((t_2 * t_2) / (alphax * alphax)) + ((t_1 * t_1) / (alphay * alphay)))) * u0) / (single(1.0) - u0))));
end
\begin{array}{l}
t_0 := \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)\\
t_1 := \sin t\_0\\
t_2 := \cos t\_0\\
\frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{t\_2 \cdot t\_2}{alphax \cdot alphax} + \frac{t\_1 \cdot t\_1}{alphay \cdot alphay}} \cdot u0}{1 - u0}}}
\end{array}

Alternative 1: 99.7% accurate, 1.6× speedup?

\[\begin{array}{l} t_0 := 2 \cdot \left(alphay \cdot alphay\right)\\ {\left(\frac{u0}{\left(\frac{t\_0 - \cos \left(\tan^{-1} \left(\tan \left(u1 \cdot 6.2831854820251465 - \pi \cdot -0.5\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right) \cdot t\_0}{4 \cdot \left(\left(alphay \cdot alphay\right) \cdot \left(alphay \cdot alphay\right)\right)} + \frac{\cos \left(\tan^{-1} \left(\tan \left(u1 \cdot 6.2831854820251465 - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right) - -1}{2 \cdot \left(alphax \cdot alphax\right)}\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5} \end{array} \]
(FPCore (u0 u1 alphax alphay)
  :precision binary32
  (let* ((t_0 (* 2.0 (* alphay alphay))))
  (pow
   (-
    (/
     u0
     (*
      (+
       (/
        (-
         t_0
         (*
          (cos
           (*
            (atan
             (*
              (tan (- (* u1 6.2831854820251465) (* PI -0.5)))
              (/ alphay alphax)))
            2.0))
          t_0))
        (* 4.0 (* (* alphay alphay) (* alphay alphay))))
       (/
        (-
         (cos
          (*
           (atan
            (*
             (tan (- (* u1 6.2831854820251465) (* -0.5 PI)))
             (/ alphay alphax)))
           2.0))
         -1.0)
        (* 2.0 (* alphax alphax))))
      (- 1.0 u0)))
    -1.0)
   -0.5)))
float code(float u0, float u1, float alphax, float alphay) {
	float t_0 = 2.0f * (alphay * alphay);
	return powf(((u0 / ((((t_0 - (cosf((atanf((tanf(((u1 * 6.2831854820251465f) - (((float) M_PI) * -0.5f))) * (alphay / alphax))) * 2.0f)) * t_0)) / (4.0f * ((alphay * alphay) * (alphay * alphay)))) + ((cosf((atanf((tanf(((u1 * 6.2831854820251465f) - (-0.5f * ((float) M_PI)))) * (alphay / alphax))) * 2.0f)) - -1.0f) / (2.0f * (alphax * alphax)))) * (1.0f - u0))) - -1.0f), -0.5f);
}
function code(u0, u1, alphax, alphay)
	t_0 = Float32(Float32(2.0) * Float32(alphay * alphay))
	return Float32(Float32(u0 / Float32(Float32(Float32(Float32(t_0 - Float32(cos(Float32(atan(Float32(tan(Float32(Float32(u1 * Float32(6.2831854820251465)) - Float32(Float32(pi) * Float32(-0.5)))) * Float32(alphay / alphax))) * Float32(2.0))) * t_0)) / Float32(Float32(4.0) * Float32(Float32(alphay * alphay) * Float32(alphay * alphay)))) + Float32(Float32(cos(Float32(atan(Float32(tan(Float32(Float32(u1 * Float32(6.2831854820251465)) - Float32(Float32(-0.5) * Float32(pi)))) * Float32(alphay / alphax))) * Float32(2.0))) - Float32(-1.0)) / Float32(Float32(2.0) * Float32(alphax * alphax)))) * Float32(Float32(1.0) - u0))) - Float32(-1.0)) ^ Float32(-0.5)
end
function tmp = code(u0, u1, alphax, alphay)
	t_0 = single(2.0) * (alphay * alphay);
	tmp = ((u0 / ((((t_0 - (cos((atan((tan(((u1 * single(6.2831854820251465)) - (single(pi) * single(-0.5)))) * (alphay / alphax))) * single(2.0))) * t_0)) / (single(4.0) * ((alphay * alphay) * (alphay * alphay)))) + ((cos((atan((tan(((u1 * single(6.2831854820251465)) - (single(-0.5) * single(pi)))) * (alphay / alphax))) * single(2.0))) - single(-1.0)) / (single(2.0) * (alphax * alphax)))) * (single(1.0) - u0))) - single(-1.0)) ^ single(-0.5);
end
\begin{array}{l}
t_0 := 2 \cdot \left(alphay \cdot alphay\right)\\
{\left(\frac{u0}{\left(\frac{t\_0 - \cos \left(\tan^{-1} \left(\tan \left(u1 \cdot 6.2831854820251465 - \pi \cdot -0.5\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right) \cdot t\_0}{4 \cdot \left(\left(alphay \cdot alphay\right) \cdot \left(alphay \cdot alphay\right)\right)} + \frac{\cos \left(\tan^{-1} \left(\tan \left(u1 \cdot 6.2831854820251465 - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right) - -1}{2 \cdot \left(alphax \cdot alphax\right)}\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5}
\end{array}
Derivation
  1. Initial program 99.4%

    \[\frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphax \cdot alphax} + \frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphay \cdot alphay}} \cdot u0}{1 - u0}}} \]
  2. Applied rewrites99.7%

    \[\leadsto \color{blue}{{\left(\frac{u0}{\left(\frac{1 - \cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right)}{2 \cdot \left(alphay \cdot alphay\right)} + \frac{\cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right) - -1}{2 \cdot \left(alphax \cdot alphax\right)}\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5}} \]
  3. Applied rewrites99.7%

    \[\leadsto {\left(\frac{u0}{\left(\color{blue}{\frac{1 \cdot \left(\left(alphay \cdot alphay\right) \cdot 2\right) - \left(\left(alphay \cdot alphay\right) \cdot 2\right) \cdot \cos \left(\tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(\pi + \pi\right) \cdot u1 - -0.5 \cdot \pi\right)\right) \cdot -2\right)}{\left(\left(alphay \cdot alphay\right) \cdot 2\right) \cdot \left(\left(alphay \cdot alphay\right) \cdot 2\right)}} + \frac{\cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right) - -1}{2 \cdot \left(alphax \cdot alphax\right)}\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5} \]
  4. Applied rewrites99.7%

    \[\leadsto {\left(\frac{u0}{\left(\color{blue}{\frac{2 \cdot \left(alphay \cdot alphay\right) - \cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - \pi \cdot -0.5\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right) \cdot \left(2 \cdot \left(alphay \cdot alphay\right)\right)}{4 \cdot \left(\left(alphay \cdot alphay\right) \cdot \left(alphay \cdot alphay\right)\right)}} + \frac{\cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right) - -1}{2 \cdot \left(alphax \cdot alphax\right)}\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5} \]
  5. Evaluated real constant99.7%

    \[\leadsto {\left(\frac{u0}{\left(\frac{2 \cdot \left(alphay \cdot alphay\right) - \cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \color{blue}{6.2831854820251465} - \pi \cdot -0.5\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right) \cdot \left(2 \cdot \left(alphay \cdot alphay\right)\right)}{4 \cdot \left(\left(alphay \cdot alphay\right) \cdot \left(alphay \cdot alphay\right)\right)} + \frac{\cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right) - -1}{2 \cdot \left(alphax \cdot alphax\right)}\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5} \]
  6. Evaluated real constant99.7%

    \[\leadsto {\left(\frac{u0}{\left(\frac{2 \cdot \left(alphay \cdot alphay\right) - \cos \left(\tan^{-1} \left(\tan \left(u1 \cdot 6.2831854820251465 - \pi \cdot -0.5\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right) \cdot \left(2 \cdot \left(alphay \cdot alphay\right)\right)}{4 \cdot \left(\left(alphay \cdot alphay\right) \cdot \left(alphay \cdot alphay\right)\right)} + \frac{\cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \color{blue}{6.2831854820251465} - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right) - -1}{2 \cdot \left(alphax \cdot alphax\right)}\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5} \]
  7. Add Preprocessing

Alternative 2: 99.7% accurate, 1.7× speedup?

\[\begin{array}{l} t_0 := \cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -1.5707963705062866\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right)\\ {\left(\frac{u0}{\left(\frac{1 - t\_0}{2 \cdot \left(alphay \cdot alphay\right)} + \frac{t\_0 - -1}{2 \cdot \left(alphax \cdot alphax\right)}\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5} \end{array} \]
(FPCore (u0 u1 alphax alphay)
  :precision binary32
  (let* ((t_0
        (cos
         (*
          (atan
           (*
            (tan (- (* u1 (+ PI PI)) -1.5707963705062866))
            (/ alphay alphax)))
          2.0))))
  (pow
   (-
    (/
     u0
     (*
      (+
       (/ (- 1.0 t_0) (* 2.0 (* alphay alphay)))
       (/ (- t_0 -1.0) (* 2.0 (* alphax alphax))))
      (- 1.0 u0)))
    -1.0)
   -0.5)))
float code(float u0, float u1, float alphax, float alphay) {
	float t_0 = cosf((atanf((tanf(((u1 * (((float) M_PI) + ((float) M_PI))) - -1.5707963705062866f)) * (alphay / alphax))) * 2.0f));
	return powf(((u0 / ((((1.0f - t_0) / (2.0f * (alphay * alphay))) + ((t_0 - -1.0f) / (2.0f * (alphax * alphax)))) * (1.0f - u0))) - -1.0f), -0.5f);
}
function code(u0, u1, alphax, alphay)
	t_0 = cos(Float32(atan(Float32(tan(Float32(Float32(u1 * Float32(Float32(pi) + Float32(pi))) - Float32(-1.5707963705062866))) * Float32(alphay / alphax))) * Float32(2.0)))
	return Float32(Float32(u0 / Float32(Float32(Float32(Float32(Float32(1.0) - t_0) / Float32(Float32(2.0) * Float32(alphay * alphay))) + Float32(Float32(t_0 - Float32(-1.0)) / Float32(Float32(2.0) * Float32(alphax * alphax)))) * Float32(Float32(1.0) - u0))) - Float32(-1.0)) ^ Float32(-0.5)
end
function tmp = code(u0, u1, alphax, alphay)
	t_0 = cos((atan((tan(((u1 * (single(pi) + single(pi))) - single(-1.5707963705062866))) * (alphay / alphax))) * single(2.0)));
	tmp = ((u0 / ((((single(1.0) - t_0) / (single(2.0) * (alphay * alphay))) + ((t_0 - single(-1.0)) / (single(2.0) * (alphax * alphax)))) * (single(1.0) - u0))) - single(-1.0)) ^ single(-0.5);
end
\begin{array}{l}
t_0 := \cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -1.5707963705062866\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right)\\
{\left(\frac{u0}{\left(\frac{1 - t\_0}{2 \cdot \left(alphay \cdot alphay\right)} + \frac{t\_0 - -1}{2 \cdot \left(alphax \cdot alphax\right)}\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5}
\end{array}
Derivation
  1. Initial program 99.4%

    \[\frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphax \cdot alphax} + \frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphay \cdot alphay}} \cdot u0}{1 - u0}}} \]
  2. Applied rewrites99.7%

    \[\leadsto \color{blue}{{\left(\frac{u0}{\left(\frac{1 - \cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right)}{2 \cdot \left(alphay \cdot alphay\right)} + \frac{\cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right) - -1}{2 \cdot \left(alphax \cdot alphax\right)}\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5}} \]
  3. Evaluated real constant99.7%

    \[\leadsto {\left(\frac{u0}{\left(\frac{1 - \cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - \color{blue}{-1.5707963705062866}\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right)}{2 \cdot \left(alphay \cdot alphay\right)} + \frac{\cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right) - -1}{2 \cdot \left(alphax \cdot alphax\right)}\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5} \]
  4. Evaluated real constant99.7%

    \[\leadsto {\left(\frac{u0}{\left(\frac{1 - \cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -1.5707963705062866\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right)}{2 \cdot \left(alphay \cdot alphay\right)} + \frac{\cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - \color{blue}{-1.5707963705062866}\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right) - -1}{2 \cdot \left(alphax \cdot alphax\right)}\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5} \]
  5. Add Preprocessing

Alternative 3: 99.2% accurate, 1.9× speedup?

\[\begin{array}{l} t_0 := \cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right)\\ \frac{1}{\sqrt{\frac{u0}{\left(\frac{1 - t\_0}{2 \cdot \left(alphay \cdot alphay\right)} + \frac{t\_0 - -1}{2 \cdot \left(alphax \cdot alphax\right)}\right) \cdot \left(1 - u0\right)} - -1}} \end{array} \]
(FPCore (u0 u1 alphax alphay)
  :precision binary32
  (let* ((t_0
        (cos
         (*
          (atan
           (*
            (tan (- (* u1 (+ PI PI)) (* -0.5 PI)))
            (/ alphay alphax)))
          2.0))))
  (/
   1.0
   (sqrt
    (-
     (/
      u0
      (*
       (+
        (/ (- 1.0 t_0) (* 2.0 (* alphay alphay)))
        (/ (- t_0 -1.0) (* 2.0 (* alphax alphax))))
       (- 1.0 u0)))
     -1.0)))))
float code(float u0, float u1, float alphax, float alphay) {
	float t_0 = cosf((atanf((tanf(((u1 * (((float) M_PI) + ((float) M_PI))) - (-0.5f * ((float) M_PI)))) * (alphay / alphax))) * 2.0f));
	return 1.0f / sqrtf(((u0 / ((((1.0f - t_0) / (2.0f * (alphay * alphay))) + ((t_0 - -1.0f) / (2.0f * (alphax * alphax)))) * (1.0f - u0))) - -1.0f));
}
function code(u0, u1, alphax, alphay)
	t_0 = cos(Float32(atan(Float32(tan(Float32(Float32(u1 * Float32(Float32(pi) + Float32(pi))) - Float32(Float32(-0.5) * Float32(pi)))) * Float32(alphay / alphax))) * Float32(2.0)))
	return Float32(Float32(1.0) / sqrt(Float32(Float32(u0 / Float32(Float32(Float32(Float32(Float32(1.0) - t_0) / Float32(Float32(2.0) * Float32(alphay * alphay))) + Float32(Float32(t_0 - Float32(-1.0)) / Float32(Float32(2.0) * Float32(alphax * alphax)))) * Float32(Float32(1.0) - u0))) - Float32(-1.0))))
end
function tmp = code(u0, u1, alphax, alphay)
	t_0 = cos((atan((tan(((u1 * (single(pi) + single(pi))) - (single(-0.5) * single(pi)))) * (alphay / alphax))) * single(2.0)));
	tmp = single(1.0) / sqrt(((u0 / ((((single(1.0) - t_0) / (single(2.0) * (alphay * alphay))) + ((t_0 - single(-1.0)) / (single(2.0) * (alphax * alphax)))) * (single(1.0) - u0))) - single(-1.0)));
end
\begin{array}{l}
t_0 := \cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right)\\
\frac{1}{\sqrt{\frac{u0}{\left(\frac{1 - t\_0}{2 \cdot \left(alphay \cdot alphay\right)} + \frac{t\_0 - -1}{2 \cdot \left(alphax \cdot alphax\right)}\right) \cdot \left(1 - u0\right)} - -1}}
\end{array}
Derivation
  1. Initial program 99.4%

    \[\frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphax \cdot alphax} + \frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphay \cdot alphay}} \cdot u0}{1 - u0}}} \]
  2. Applied rewrites99.2%

    \[\leadsto \frac{1}{\sqrt{\color{blue}{\frac{u0}{\left(\frac{1 - \cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right)}{2 \cdot \left(alphay \cdot alphay\right)} + \frac{\cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right) - -1}{2 \cdot \left(alphax \cdot alphax\right)}\right) \cdot \left(1 - u0\right)} - -1}}} \]
  3. Add Preprocessing

Alternative 4: 98.2% accurate, 3.0× speedup?

\[{\left(\frac{\left(alphay \cdot alphay\right) \cdot u0}{\left(0.5 - 0.5 \cdot \cos \left(\tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(\pi + \pi\right) \cdot u1 - -1.5707963705062866\right)\right) \cdot -2\right)\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5} \]
(FPCore (u0 u1 alphax alphay)
  :precision binary32
  (pow
 (-
  (/
   (* (* alphay alphay) u0)
   (*
    (-
     0.5
     (*
      0.5
      (cos
       (*
        (atan
         (*
          (/ alphay alphax)
          (tan (- (* (+ PI PI) u1) -1.5707963705062866))))
        -2.0))))
    (- 1.0 u0)))
  -1.0)
 -0.5))
float code(float u0, float u1, float alphax, float alphay) {
	return powf(((((alphay * alphay) * u0) / ((0.5f - (0.5f * cosf((atanf(((alphay / alphax) * tanf((((((float) M_PI) + ((float) M_PI)) * u1) - -1.5707963705062866f)))) * -2.0f)))) * (1.0f - u0))) - -1.0f), -0.5f);
}
function code(u0, u1, alphax, alphay)
	return Float32(Float32(Float32(Float32(alphay * alphay) * u0) / Float32(Float32(Float32(0.5) - Float32(Float32(0.5) * cos(Float32(atan(Float32(Float32(alphay / alphax) * tan(Float32(Float32(Float32(Float32(pi) + Float32(pi)) * u1) - Float32(-1.5707963705062866))))) * Float32(-2.0))))) * Float32(Float32(1.0) - u0))) - Float32(-1.0)) ^ Float32(-0.5)
end
function tmp = code(u0, u1, alphax, alphay)
	tmp = ((((alphay * alphay) * u0) / ((single(0.5) - (single(0.5) * cos((atan(((alphay / alphax) * tan((((single(pi) + single(pi)) * u1) - single(-1.5707963705062866))))) * single(-2.0))))) * (single(1.0) - u0))) - single(-1.0)) ^ single(-0.5);
end
{\left(\frac{\left(alphay \cdot alphay\right) \cdot u0}{\left(0.5 - 0.5 \cdot \cos \left(\tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(\pi + \pi\right) \cdot u1 - -1.5707963705062866\right)\right) \cdot -2\right)\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5}
Derivation
  1. Initial program 99.4%

    \[\frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphax \cdot alphax} + \frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphay \cdot alphay}} \cdot u0}{1 - u0}}} \]
  2. Taylor expanded in alphax around inf

    \[\leadsto \frac{1}{\sqrt{1 + \color{blue}{\frac{{alphay}^{2} \cdot u0}{{\sin \tan^{-1} \left(\frac{alphay \cdot \sin \left(\frac{1}{2} \cdot \pi + 2 \cdot \left(u1 \cdot \pi\right)\right)}{alphax \cdot \cos \left(\frac{1}{2} \cdot \pi + 2 \cdot \left(u1 \cdot \pi\right)\right)}\right)}^{2} \cdot \left(1 - u0\right)}}}} \]
  3. Step-by-step derivation
    1. lower-/.f32N/A

      \[\leadsto \frac{1}{\sqrt{1 + \frac{{alphay}^{2} \cdot u0}{\color{blue}{{\sin \tan^{-1} \left(\frac{alphay \cdot \sin \left(\frac{1}{2} \cdot \mathsf{PI}\left(\right) + 2 \cdot \left(u1 \cdot \mathsf{PI}\left(\right)\right)\right)}{alphax \cdot \cos \left(\frac{1}{2} \cdot \mathsf{PI}\left(\right) + 2 \cdot \left(u1 \cdot \mathsf{PI}\left(\right)\right)\right)}\right)}^{2} \cdot \left(1 - u0\right)}}}} \]
  4. Applied rewrites97.8%

    \[\leadsto \frac{1}{\sqrt{1 + \color{blue}{\frac{{alphay}^{2} \cdot u0}{{\sin \tan^{-1} \left(\frac{alphay \cdot \sin \left(0.5 \cdot \pi + 2 \cdot \left(u1 \cdot \pi\right)\right)}{alphax \cdot \cos \left(0.5 \cdot \pi + 2 \cdot \left(u1 \cdot \pi\right)\right)}\right)}^{2} \cdot \left(1 - u0\right)}}}} \]
  5. Applied rewrites98.2%

    \[\leadsto \color{blue}{{\left(\frac{\left(alphay \cdot alphay\right) \cdot u0}{\left(0.5 - 0.5 \cdot \cos \left(\tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(\pi + \pi\right) \cdot u1 - -0.5 \cdot \pi\right)\right) \cdot -2\right)\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5}} \]
  6. Evaluated real constant98.2%

    \[\leadsto {\left(\frac{\left(alphay \cdot alphay\right) \cdot u0}{\left(0.5 - 0.5 \cdot \cos \left(\tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(\pi + \pi\right) \cdot u1 - -1.5707963705062866\right)\right) \cdot -2\right)\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5} \]
  7. Add Preprocessing

Alternative 5: 98.2% accurate, 3.1× speedup?

\[{\left(\frac{\left(alphay \cdot alphay\right) \cdot u0}{\left(0.5 - 0.5 \cdot \cos \left(\tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan 1.5707963705062866\right) \cdot -2\right)\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5} \]
(FPCore (u0 u1 alphax alphay)
  :precision binary32
  (pow
 (-
  (/
   (* (* alphay alphay) u0)
   (*
    (-
     0.5
     (*
      0.5
      (cos
       (*
        (atan (* (/ alphay alphax) (tan 1.5707963705062866)))
        -2.0))))
    (- 1.0 u0)))
  -1.0)
 -0.5))
float code(float u0, float u1, float alphax, float alphay) {
	return powf(((((alphay * alphay) * u0) / ((0.5f - (0.5f * cosf((atanf(((alphay / alphax) * tanf(1.5707963705062866f))) * -2.0f)))) * (1.0f - u0))) - -1.0f), -0.5f);
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(4) function code(u0, u1, alphax, alphay)
use fmin_fmax_functions
    real(4), intent (in) :: u0
    real(4), intent (in) :: u1
    real(4), intent (in) :: alphax
    real(4), intent (in) :: alphay
    code = ((((alphay * alphay) * u0) / ((0.5e0 - (0.5e0 * cos((atan(((alphay / alphax) * tan(1.5707963705062866e0))) * (-2.0e0))))) * (1.0e0 - u0))) - (-1.0e0)) ** (-0.5e0)
end function
function code(u0, u1, alphax, alphay)
	return Float32(Float32(Float32(Float32(alphay * alphay) * u0) / Float32(Float32(Float32(0.5) - Float32(Float32(0.5) * cos(Float32(atan(Float32(Float32(alphay / alphax) * tan(Float32(1.5707963705062866)))) * Float32(-2.0))))) * Float32(Float32(1.0) - u0))) - Float32(-1.0)) ^ Float32(-0.5)
end
function tmp = code(u0, u1, alphax, alphay)
	tmp = ((((alphay * alphay) * u0) / ((single(0.5) - (single(0.5) * cos((atan(((alphay / alphax) * tan(single(1.5707963705062866)))) * single(-2.0))))) * (single(1.0) - u0))) - single(-1.0)) ^ single(-0.5);
end
{\left(\frac{\left(alphay \cdot alphay\right) \cdot u0}{\left(0.5 - 0.5 \cdot \cos \left(\tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan 1.5707963705062866\right) \cdot -2\right)\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5}
Derivation
  1. Initial program 99.4%

    \[\frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphax \cdot alphax} + \frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphay \cdot alphay}} \cdot u0}{1 - u0}}} \]
  2. Taylor expanded in alphax around inf

    \[\leadsto \frac{1}{\sqrt{1 + \color{blue}{\frac{{alphay}^{2} \cdot u0}{{\sin \tan^{-1} \left(\frac{alphay \cdot \sin \left(\frac{1}{2} \cdot \pi + 2 \cdot \left(u1 \cdot \pi\right)\right)}{alphax \cdot \cos \left(\frac{1}{2} \cdot \pi + 2 \cdot \left(u1 \cdot \pi\right)\right)}\right)}^{2} \cdot \left(1 - u0\right)}}}} \]
  3. Step-by-step derivation
    1. lower-/.f32N/A

      \[\leadsto \frac{1}{\sqrt{1 + \frac{{alphay}^{2} \cdot u0}{\color{blue}{{\sin \tan^{-1} \left(\frac{alphay \cdot \sin \left(\frac{1}{2} \cdot \mathsf{PI}\left(\right) + 2 \cdot \left(u1 \cdot \mathsf{PI}\left(\right)\right)\right)}{alphax \cdot \cos \left(\frac{1}{2} \cdot \mathsf{PI}\left(\right) + 2 \cdot \left(u1 \cdot \mathsf{PI}\left(\right)\right)\right)}\right)}^{2} \cdot \left(1 - u0\right)}}}} \]
  4. Applied rewrites97.8%

    \[\leadsto \frac{1}{\sqrt{1 + \color{blue}{\frac{{alphay}^{2} \cdot u0}{{\sin \tan^{-1} \left(\frac{alphay \cdot \sin \left(0.5 \cdot \pi + 2 \cdot \left(u1 \cdot \pi\right)\right)}{alphax \cdot \cos \left(0.5 \cdot \pi + 2 \cdot \left(u1 \cdot \pi\right)\right)}\right)}^{2} \cdot \left(1 - u0\right)}}}} \]
  5. Applied rewrites98.2%

    \[\leadsto \color{blue}{{\left(\frac{\left(alphay \cdot alphay\right) \cdot u0}{\left(0.5 - 0.5 \cdot \cos \left(\tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(\pi + \pi\right) \cdot u1 - -0.5 \cdot \pi\right)\right) \cdot -2\right)\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5}} \]
  6. Taylor expanded in u1 around 0

    \[\leadsto {\left(\frac{\left(alphay \cdot alphay\right) \cdot u0}{\left(0.5 - 0.5 \cdot \cos \left(\tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\frac{1}{2} \cdot \pi\right)\right) \cdot -2\right)\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5} \]
  7. Step-by-step derivation
    1. lower-*.f32N/A

      \[\leadsto {\left(\frac{\left(alphay \cdot alphay\right) \cdot u0}{\left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(\tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)\right) \cdot -2\right)\right) \cdot \left(1 - u0\right)} - -1\right)}^{\frac{-1}{2}} \]
    2. lower-PI.f3298.2%

      \[\leadsto {\left(\frac{\left(alphay \cdot alphay\right) \cdot u0}{\left(0.5 - 0.5 \cdot \cos \left(\tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(0.5 \cdot \pi\right)\right) \cdot -2\right)\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5} \]
  8. Applied rewrites98.2%

    \[\leadsto {\left(\frac{\left(alphay \cdot alphay\right) \cdot u0}{\left(0.5 - 0.5 \cdot \cos \left(\tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(0.5 \cdot \pi\right)\right) \cdot -2\right)\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5} \]
  9. Evaluated real constant98.2%

    \[\leadsto {\left(\frac{\left(alphay \cdot alphay\right) \cdot u0}{\left(0.5 - 0.5 \cdot \cos \left(\tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan 1.5707963705062866\right) \cdot -2\right)\right) \cdot \left(1 - u0\right)} - -1\right)}^{-0.5} \]
  10. Add Preprocessing

Alternative 6: 97.8% accurate, 3.6× speedup?

\[\frac{1}{\sqrt{\frac{\left(alphay \cdot alphay\right) \cdot u0}{\left(0.5 - 0.5 \cdot \cos \left(\tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(\pi + \pi\right) \cdot u1 - -0.5 \cdot \pi\right)\right) \cdot -2\right)\right) \cdot \left(1 - u0\right)} - -1}} \]
(FPCore (u0 u1 alphax alphay)
  :precision binary32
  (/
 1.0
 (sqrt
  (-
   (/
    (* (* alphay alphay) u0)
    (*
     (-
      0.5
      (*
       0.5
       (cos
        (*
         (atan
          (*
           (/ alphay alphax)
           (tan (- (* (+ PI PI) u1) (* -0.5 PI)))))
         -2.0))))
     (- 1.0 u0)))
   -1.0))))
float code(float u0, float u1, float alphax, float alphay) {
	return 1.0f / sqrtf(((((alphay * alphay) * u0) / ((0.5f - (0.5f * cosf((atanf(((alphay / alphax) * tanf((((((float) M_PI) + ((float) M_PI)) * u1) - (-0.5f * ((float) M_PI)))))) * -2.0f)))) * (1.0f - u0))) - -1.0f));
}
function code(u0, u1, alphax, alphay)
	return Float32(Float32(1.0) / sqrt(Float32(Float32(Float32(Float32(alphay * alphay) * u0) / Float32(Float32(Float32(0.5) - Float32(Float32(0.5) * cos(Float32(atan(Float32(Float32(alphay / alphax) * tan(Float32(Float32(Float32(Float32(pi) + Float32(pi)) * u1) - Float32(Float32(-0.5) * Float32(pi)))))) * Float32(-2.0))))) * Float32(Float32(1.0) - u0))) - Float32(-1.0))))
end
function tmp = code(u0, u1, alphax, alphay)
	tmp = single(1.0) / sqrt(((((alphay * alphay) * u0) / ((single(0.5) - (single(0.5) * cos((atan(((alphay / alphax) * tan((((single(pi) + single(pi)) * u1) - (single(-0.5) * single(pi)))))) * single(-2.0))))) * (single(1.0) - u0))) - single(-1.0)));
end
\frac{1}{\sqrt{\frac{\left(alphay \cdot alphay\right) \cdot u0}{\left(0.5 - 0.5 \cdot \cos \left(\tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(\pi + \pi\right) \cdot u1 - -0.5 \cdot \pi\right)\right) \cdot -2\right)\right) \cdot \left(1 - u0\right)} - -1}}
Derivation
  1. Initial program 99.4%

    \[\frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphax \cdot alphax} + \frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphay \cdot alphay}} \cdot u0}{1 - u0}}} \]
  2. Taylor expanded in alphax around inf

    \[\leadsto \frac{1}{\sqrt{1 + \color{blue}{\frac{{alphay}^{2} \cdot u0}{{\sin \tan^{-1} \left(\frac{alphay \cdot \sin \left(\frac{1}{2} \cdot \pi + 2 \cdot \left(u1 \cdot \pi\right)\right)}{alphax \cdot \cos \left(\frac{1}{2} \cdot \pi + 2 \cdot \left(u1 \cdot \pi\right)\right)}\right)}^{2} \cdot \left(1 - u0\right)}}}} \]
  3. Step-by-step derivation
    1. lower-/.f32N/A

      \[\leadsto \frac{1}{\sqrt{1 + \frac{{alphay}^{2} \cdot u0}{\color{blue}{{\sin \tan^{-1} \left(\frac{alphay \cdot \sin \left(\frac{1}{2} \cdot \mathsf{PI}\left(\right) + 2 \cdot \left(u1 \cdot \mathsf{PI}\left(\right)\right)\right)}{alphax \cdot \cos \left(\frac{1}{2} \cdot \mathsf{PI}\left(\right) + 2 \cdot \left(u1 \cdot \mathsf{PI}\left(\right)\right)\right)}\right)}^{2} \cdot \left(1 - u0\right)}}}} \]
  4. Applied rewrites97.8%

    \[\leadsto \frac{1}{\sqrt{1 + \color{blue}{\frac{{alphay}^{2} \cdot u0}{{\sin \tan^{-1} \left(\frac{alphay \cdot \sin \left(0.5 \cdot \pi + 2 \cdot \left(u1 \cdot \pi\right)\right)}{alphax \cdot \cos \left(0.5 \cdot \pi + 2 \cdot \left(u1 \cdot \pi\right)\right)}\right)}^{2} \cdot \left(1 - u0\right)}}}} \]
  5. Applied rewrites97.8%

    \[\leadsto \frac{1}{\sqrt{\color{blue}{\frac{\left(alphay \cdot alphay\right) \cdot u0}{\left(0.5 - 0.5 \cdot \cos \left(\tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(\pi + \pi\right) \cdot u1 - -0.5 \cdot \pi\right)\right) \cdot -2\right)\right) \cdot \left(1 - u0\right)} - -1}}} \]
  6. Add Preprocessing

Alternative 7: 91.5% accurate, 32.6× speedup?

\[\frac{1}{\sqrt{-1 \cdot \frac{1 - u0}{u0 - 1}}} \]
(FPCore (u0 u1 alphax alphay)
  :precision binary32
  (/ 1.0 (sqrt (* -1.0 (/ (- 1.0 u0) (- u0 1.0))))))
float code(float u0, float u1, float alphax, float alphay) {
	return 1.0f / sqrtf((-1.0f * ((1.0f - u0) / (u0 - 1.0f))));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(4) function code(u0, u1, alphax, alphay)
use fmin_fmax_functions
    real(4), intent (in) :: u0
    real(4), intent (in) :: u1
    real(4), intent (in) :: alphax
    real(4), intent (in) :: alphay
    code = 1.0e0 / sqrt(((-1.0e0) * ((1.0e0 - u0) / (u0 - 1.0e0))))
end function
function code(u0, u1, alphax, alphay)
	return Float32(Float32(1.0) / sqrt(Float32(Float32(-1.0) * Float32(Float32(Float32(1.0) - u0) / Float32(u0 - Float32(1.0))))))
end
function tmp = code(u0, u1, alphax, alphay)
	tmp = single(1.0) / sqrt((single(-1.0) * ((single(1.0) - u0) / (u0 - single(1.0)))));
end
\frac{1}{\sqrt{-1 \cdot \frac{1 - u0}{u0 - 1}}}
Derivation
  1. Initial program 99.4%

    \[\frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphax \cdot alphax} + \frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphay \cdot alphay}} \cdot u0}{1 - u0}}} \]
  2. Applied rewrites99.3%

    \[\leadsto \frac{1}{\sqrt{1 + \frac{\frac{1}{\color{blue}{\frac{1 - \cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right)}{2 \cdot \left(alphay \cdot alphay\right)} - \frac{-1}{\sqrt{{\left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right)}^{2} + 1}} \cdot \frac{1}{\sqrt{{\left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right)}^{2} + 1} \cdot \left(alphax \cdot alphax\right)}}} \cdot u0}{1 - u0}}} \]
  3. Taylor expanded in alphax around inf

    \[\leadsto \frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{1 - \cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right)}{2 \cdot \left(alphay \cdot alphay\right)} - \color{blue}{-1} \cdot \frac{1}{\sqrt{{\left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right)}^{2} + 1} \cdot \left(alphax \cdot alphax\right)}} \cdot u0}{1 - u0}}} \]
  4. Step-by-step derivation
    1. Applied rewrites96.9%

      \[\leadsto \frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{1 - \cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right)}{2 \cdot \left(alphay \cdot alphay\right)} - \color{blue}{-1} \cdot \frac{1}{\sqrt{{\left(\tan \left(u1 \cdot \left(\pi + \pi\right) - -0.5 \cdot \pi\right) \cdot \frac{alphay}{alphax}\right)}^{2} + 1} \cdot \left(alphax \cdot alphax\right)}} \cdot u0}{1 - u0}}} \]
    2. Applied rewrites96.7%

      \[\leadsto \frac{1}{\sqrt{\color{blue}{\left(1 \cdot \left(1 - u0\right) + \frac{u0}{\frac{1 - \cos \left(\tan^{-1} \left(\tan \left(u1 \cdot \left(\pi + \pi\right) - \pi \cdot -0.5\right) \cdot \frac{alphay}{alphax}\right) \cdot 2\right)}{2 \cdot \left(alphay \cdot alphay\right)} - \frac{-1}{\sqrt{{\left(\tan \left(u1 \cdot \left(\pi + \pi\right) - \pi \cdot -0.5\right) \cdot \frac{alphay}{alphax}\right)}^{2} - -1} \cdot \left(alphax \cdot alphax\right)}}\right) \cdot \frac{-1}{u0 - 1}}}} \]
    3. Taylor expanded in alphay around 0

      \[\leadsto \frac{1}{\sqrt{\color{blue}{-1 \cdot \frac{1 - u0}{u0 - 1}}}} \]
    4. Step-by-step derivation
      1. lower-*.f32N/A

        \[\leadsto \frac{1}{\sqrt{-1 \cdot \color{blue}{\frac{1 - u0}{u0 - 1}}}} \]
      2. lower-/.f32N/A

        \[\leadsto \frac{1}{\sqrt{-1 \cdot \frac{1 - u0}{\color{blue}{u0 - 1}}}} \]
      3. lower--.f32N/A

        \[\leadsto \frac{1}{\sqrt{-1 \cdot \frac{1 - u0}{\color{blue}{u0} - 1}}} \]
      4. lower--.f3291.5%

        \[\leadsto \frac{1}{\sqrt{-1 \cdot \frac{1 - u0}{u0 - \color{blue}{1}}}} \]
    5. Applied rewrites91.5%

      \[\leadsto \frac{1}{\sqrt{\color{blue}{-1 \cdot \frac{1 - u0}{u0 - 1}}}} \]
    6. Add Preprocessing

    Reproduce

    ?
    herbie shell --seed 2025258 
    (FPCore (u0 u1 alphax alphay)
      :name "Trowbridge-Reitz Sample, sample surface normal, cosTheta"
      :precision binary32
      :pre (and (and (and (and (<= 2.328306437e-10 u0) (<= u0 1.0)) (and (<= 2.328306437e-10 u1) (<= u1 0.5))) (and (<= 0.0001 alphax) (<= alphax 1.0))) (and (<= 0.0001 alphay) (<= alphay 1.0)))
      (/ 1.0 (sqrt (+ 1.0 (/ (* (/ 1.0 (+ (/ (* (cos (atan (* (/ alphay alphax) (tan (+ (* (* 2.0 PI) u1) (* 0.5 PI)))))) (cos (atan (* (/ alphay alphax) (tan (+ (* (* 2.0 PI) u1) (* 0.5 PI))))))) (* alphax alphax)) (/ (* (sin (atan (* (/ alphay alphax) (tan (+ (* (* 2.0 PI) u1) (* 0.5 PI)))))) (sin (atan (* (/ alphay alphax) (tan (+ (* (* 2.0 PI) u1) (* 0.5 PI))))))) (* alphay alphay)))) u0) (- 1.0 u0))))))