HairBSDF, Mp, lower

Percentage Accurate: 99.5% → 99.3%
Time: 12.8s
Alternatives: 6
Speedup: 2.1×

Specification

?
\[\left(\left(\left(\left(-1 \leq cosTheta\_i \land cosTheta\_i \leq 1\right) \land \left(-1 \leq cosTheta\_O \land cosTheta\_O \leq 1\right)\right) \land \left(-1 \leq sinTheta\_i \land sinTheta\_i \leq 1\right)\right) \land \left(-1 \leq sinTheta\_O \land sinTheta\_O \leq 1\right)\right) \land \left(-1.5707964 \leq v \land v \leq 0.1\right)\]
\[\begin{array}{l} \\ e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)} \end{array} \]
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
 :precision binary32
 (exp
  (+
   (+
    (-
     (- (/ (* cosTheta_i cosTheta_O) v) (/ (* sinTheta_i sinTheta_O) v))
     (/ 1.0 v))
    0.6931)
   (log (/ 1.0 (* 2.0 v))))))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
	return expf(((((((cosTheta_i * cosTheta_O) / v) - ((sinTheta_i * sinTheta_O) / v)) - (1.0f / v)) + 0.6931f) + logf((1.0f / (2.0f * v)))));
}
real(4) function code(costheta_i, costheta_o, sintheta_i, sintheta_o, v)
    real(4), intent (in) :: costheta_i
    real(4), intent (in) :: costheta_o
    real(4), intent (in) :: sintheta_i
    real(4), intent (in) :: sintheta_o
    real(4), intent (in) :: v
    code = exp(((((((costheta_i * costheta_o) / v) - ((sintheta_i * sintheta_o) / v)) - (1.0e0 / v)) + 0.6931e0) + log((1.0e0 / (2.0e0 * v)))))
end function
function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
	return exp(Float32(Float32(Float32(Float32(Float32(Float32(cosTheta_i * cosTheta_O) / v) - Float32(Float32(sinTheta_i * sinTheta_O) / v)) - Float32(Float32(1.0) / v)) + Float32(0.6931)) + log(Float32(Float32(1.0) / Float32(Float32(2.0) * v)))))
end
function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
	tmp = exp(((((((cosTheta_i * cosTheta_O) / v) - ((sinTheta_i * sinTheta_O) / v)) - (single(1.0) / v)) + single(0.6931)) + log((single(1.0) / (single(2.0) * v)))));
end
\begin{array}{l}

\\
e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)}
\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 6 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: 99.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)} \end{array} \]
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
 :precision binary32
 (exp
  (+
   (+
    (-
     (- (/ (* cosTheta_i cosTheta_O) v) (/ (* sinTheta_i sinTheta_O) v))
     (/ 1.0 v))
    0.6931)
   (log (/ 1.0 (* 2.0 v))))))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
	return expf(((((((cosTheta_i * cosTheta_O) / v) - ((sinTheta_i * sinTheta_O) / v)) - (1.0f / v)) + 0.6931f) + logf((1.0f / (2.0f * v)))));
}
real(4) function code(costheta_i, costheta_o, sintheta_i, sintheta_o, v)
    real(4), intent (in) :: costheta_i
    real(4), intent (in) :: costheta_o
    real(4), intent (in) :: sintheta_i
    real(4), intent (in) :: sintheta_o
    real(4), intent (in) :: v
    code = exp(((((((costheta_i * costheta_o) / v) - ((sintheta_i * sintheta_o) / v)) - (1.0e0 / v)) + 0.6931e0) + log((1.0e0 / (2.0e0 * v)))))
end function
function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
	return exp(Float32(Float32(Float32(Float32(Float32(Float32(cosTheta_i * cosTheta_O) / v) - Float32(Float32(sinTheta_i * sinTheta_O) / v)) - Float32(Float32(1.0) / v)) + Float32(0.6931)) + log(Float32(Float32(1.0) / Float32(Float32(2.0) * v)))))
end
function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
	tmp = exp(((((((cosTheta_i * cosTheta_O) / v) - ((sinTheta_i * sinTheta_O) / v)) - (single(1.0) / v)) + single(0.6931)) + log((single(1.0) / (single(2.0) * v)))));
end
\begin{array}{l}

\\
e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)}
\end{array}

Alternative 1: 99.3% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := 0.6931 - \frac{-1}{v}\\ 0.5 \cdot \frac{\frac{e^{\frac{0.48038761}{t\_0}}}{{\left(e^{1}\right)}^{\left(\frac{{v}^{-2}}{t\_0}\right)}}}{v} \end{array} \end{array} \]
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
 :precision binary32
 (let* ((t_0 (- 0.6931 (/ -1.0 v))))
   (*
    0.5
    (/ (/ (exp (/ 0.48038761 t_0)) (pow (exp 1.0) (/ (pow v -2.0) t_0))) v))))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
	float t_0 = 0.6931f - (-1.0f / v);
	return 0.5f * ((expf((0.48038761f / t_0)) / powf(expf(1.0f), (powf(v, -2.0f) / t_0))) / v);
}
real(4) function code(costheta_i, costheta_o, sintheta_i, sintheta_o, v)
    real(4), intent (in) :: costheta_i
    real(4), intent (in) :: costheta_o
    real(4), intent (in) :: sintheta_i
    real(4), intent (in) :: sintheta_o
    real(4), intent (in) :: v
    real(4) :: t_0
    t_0 = 0.6931e0 - ((-1.0e0) / v)
    code = 0.5e0 * ((exp((0.48038761e0 / t_0)) / (exp(1.0e0) ** ((v ** (-2.0e0)) / t_0))) / v)
end function
function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
	t_0 = Float32(Float32(0.6931) - Float32(Float32(-1.0) / v))
	return Float32(Float32(0.5) * Float32(Float32(exp(Float32(Float32(0.48038761) / t_0)) / (exp(Float32(1.0)) ^ Float32((v ^ Float32(-2.0)) / t_0))) / v))
end
function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
	t_0 = single(0.6931) - (single(-1.0) / v);
	tmp = single(0.5) * ((exp((single(0.48038761) / t_0)) / (exp(single(1.0)) ^ ((v ^ single(-2.0)) / t_0))) / v);
end
\begin{array}{l}

\\
\begin{array}{l}
t_0 := 0.6931 - \frac{-1}{v}\\
0.5 \cdot \frac{\frac{e^{\frac{0.48038761}{t\_0}}}{{\left(e^{1}\right)}^{\left(\frac{{v}^{-2}}{t\_0}\right)}}}{v}
\end{array}
\end{array}
Derivation
  1. Initial program 99.6%

    \[e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)} \]
  2. Add Preprocessing
  3. Taylor expanded in sinTheta_i around 0

    \[\leadsto \color{blue}{e^{\left(\frac{6931}{10000} + \left(\log \left(\frac{\frac{1}{2}}{v}\right) + \frac{cosTheta\_O \cdot cosTheta\_i}{v}\right)\right) - \frac{1}{v}}} \]
  4. Step-by-step derivation
    1. associate-+r+N/A

      \[\leadsto e^{\color{blue}{\left(\left(\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)\right) + \frac{cosTheta\_O \cdot cosTheta\_i}{v}\right)} - \frac{1}{v}} \]
    2. associate--l+N/A

      \[\leadsto e^{\color{blue}{\left(\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)\right) + \left(\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}\right)}} \]
    3. exp-sumN/A

      \[\leadsto \color{blue}{e^{\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}}} \]
    4. lower-*.f32N/A

      \[\leadsto \color{blue}{e^{\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}}} \]
    5. +-commutativeN/A

      \[\leadsto e^{\color{blue}{\log \left(\frac{\frac{1}{2}}{v}\right) + \frac{6931}{10000}}} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
    6. exp-sumN/A

      \[\leadsto \color{blue}{\left(e^{\log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{6931}{10000}}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
    7. lower-*.f32N/A

      \[\leadsto \color{blue}{\left(e^{\log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{6931}{10000}}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
    8. rem-exp-logN/A

      \[\leadsto \left(\color{blue}{\frac{\frac{1}{2}}{v}} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
    9. lower-/.f32N/A

      \[\leadsto \left(\color{blue}{\frac{\frac{1}{2}}{v}} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
    10. lower-exp.f32N/A

      \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot \color{blue}{e^{\frac{6931}{10000}}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
    11. lower-exp.f32N/A

      \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot \color{blue}{e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}}} \]
    12. div-subN/A

      \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\color{blue}{\frac{cosTheta\_O \cdot cosTheta\_i - 1}{v}}} \]
    13. lower-/.f32N/A

      \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\color{blue}{\frac{cosTheta\_O \cdot cosTheta\_i - 1}{v}}} \]
    14. sub-negN/A

      \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{\color{blue}{cosTheta\_O \cdot cosTheta\_i + \left(\mathsf{neg}\left(1\right)\right)}}{v}} \]
    15. metadata-evalN/A

      \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i + \color{blue}{-1}}{v}} \]
    16. lower-fma.f3240.4

      \[\leadsto \left(\frac{0.5}{v} \cdot e^{0.6931}\right) \cdot e^{\frac{\color{blue}{\mathsf{fma}\left(cosTheta\_O, cosTheta\_i, -1\right)}}{v}} \]
  5. Applied rewrites40.4%

    \[\leadsto \color{blue}{\left(\frac{0.5}{v} \cdot e^{0.6931}\right) \cdot e^{\frac{\mathsf{fma}\left(cosTheta\_O, cosTheta\_i, -1\right)}{v}}} \]
  6. Taylor expanded in cosTheta_i around 0

    \[\leadsto \frac{1}{2} \cdot \color{blue}{\frac{e^{\frac{6931}{10000}} \cdot e^{\frac{-1}{v}}}{v}} \]
  7. Step-by-step derivation
    1. Applied rewrites99.6%

      \[\leadsto 0.5 \cdot \color{blue}{\frac{e^{0.6931 + \frac{-1}{v}}}{v}} \]
    2. Step-by-step derivation
      1. Applied rewrites99.6%

        \[\leadsto 0.5 \cdot \frac{\frac{e^{\frac{0.48038761}{0.6931 - \frac{-1}{v}}}}{e^{\frac{{v}^{-2}}{0.6931 - \frac{-1}{v}}}}}{v} \]
      2. Step-by-step derivation
        1. Applied rewrites99.7%

          \[\leadsto 0.5 \cdot \frac{\frac{e^{\frac{0.48038761}{0.6931 - \frac{-1}{v}}}}{{\left(e^{1}\right)}^{\left(\frac{{v}^{-2}}{0.6931 - \frac{-1}{v}}\right)}}}{v} \]
        2. Add Preprocessing

        Alternative 2: 99.7% accurate, 1.2× speedup?

        \[\begin{array}{l} \\ 0.5 \cdot e^{\left(\frac{-1}{v} + 0.6931\right) - \log v} \end{array} \]
        (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
         :precision binary32
         (* 0.5 (exp (- (+ (/ -1.0 v) 0.6931) (log v)))))
        float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
        	return 0.5f * expf((((-1.0f / v) + 0.6931f) - logf(v)));
        }
        
        real(4) function code(costheta_i, costheta_o, sintheta_i, sintheta_o, v)
            real(4), intent (in) :: costheta_i
            real(4), intent (in) :: costheta_o
            real(4), intent (in) :: sintheta_i
            real(4), intent (in) :: sintheta_o
            real(4), intent (in) :: v
            code = 0.5e0 * exp(((((-1.0e0) / v) + 0.6931e0) - log(v)))
        end function
        
        function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
        	return Float32(Float32(0.5) * exp(Float32(Float32(Float32(Float32(-1.0) / v) + Float32(0.6931)) - log(v))))
        end
        
        function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
        	tmp = single(0.5) * exp((((single(-1.0) / v) + single(0.6931)) - log(v)));
        end
        
        \begin{array}{l}
        
        \\
        0.5 \cdot e^{\left(\frac{-1}{v} + 0.6931\right) - \log v}
        \end{array}
        
        Derivation
        1. Initial program 99.6%

          \[e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)} \]
        2. Add Preprocessing
        3. Taylor expanded in sinTheta_i around 0

          \[\leadsto \color{blue}{e^{\left(\frac{6931}{10000} + \left(\log \left(\frac{\frac{1}{2}}{v}\right) + \frac{cosTheta\_O \cdot cosTheta\_i}{v}\right)\right) - \frac{1}{v}}} \]
        4. Step-by-step derivation
          1. associate-+r+N/A

            \[\leadsto e^{\color{blue}{\left(\left(\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)\right) + \frac{cosTheta\_O \cdot cosTheta\_i}{v}\right)} - \frac{1}{v}} \]
          2. associate--l+N/A

            \[\leadsto e^{\color{blue}{\left(\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)\right) + \left(\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}\right)}} \]
          3. exp-sumN/A

            \[\leadsto \color{blue}{e^{\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}}} \]
          4. lower-*.f32N/A

            \[\leadsto \color{blue}{e^{\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}}} \]
          5. +-commutativeN/A

            \[\leadsto e^{\color{blue}{\log \left(\frac{\frac{1}{2}}{v}\right) + \frac{6931}{10000}}} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
          6. exp-sumN/A

            \[\leadsto \color{blue}{\left(e^{\log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{6931}{10000}}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
          7. lower-*.f32N/A

            \[\leadsto \color{blue}{\left(e^{\log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{6931}{10000}}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
          8. rem-exp-logN/A

            \[\leadsto \left(\color{blue}{\frac{\frac{1}{2}}{v}} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
          9. lower-/.f32N/A

            \[\leadsto \left(\color{blue}{\frac{\frac{1}{2}}{v}} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
          10. lower-exp.f32N/A

            \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot \color{blue}{e^{\frac{6931}{10000}}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
          11. lower-exp.f32N/A

            \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot \color{blue}{e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}}} \]
          12. div-subN/A

            \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\color{blue}{\frac{cosTheta\_O \cdot cosTheta\_i - 1}{v}}} \]
          13. lower-/.f32N/A

            \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\color{blue}{\frac{cosTheta\_O \cdot cosTheta\_i - 1}{v}}} \]
          14. sub-negN/A

            \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{\color{blue}{cosTheta\_O \cdot cosTheta\_i + \left(\mathsf{neg}\left(1\right)\right)}}{v}} \]
          15. metadata-evalN/A

            \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i + \color{blue}{-1}}{v}} \]
          16. lower-fma.f3240.8

            \[\leadsto \left(\frac{0.5}{v} \cdot e^{0.6931}\right) \cdot e^{\frac{\color{blue}{\mathsf{fma}\left(cosTheta\_O, cosTheta\_i, -1\right)}}{v}} \]
        5. Applied rewrites40.7%

          \[\leadsto \color{blue}{\left(\frac{0.5}{v} \cdot e^{0.6931}\right) \cdot e^{\frac{\mathsf{fma}\left(cosTheta\_O, cosTheta\_i, -1\right)}{v}}} \]
        6. Taylor expanded in cosTheta_i around 0

          \[\leadsto \frac{1}{2} \cdot \color{blue}{\frac{e^{\frac{6931}{10000}} \cdot e^{\frac{-1}{v}}}{v}} \]
        7. Step-by-step derivation
          1. Applied rewrites99.6%

            \[\leadsto 0.5 \cdot \color{blue}{\frac{e^{0.6931 + \frac{-1}{v}}}{v}} \]
          2. Step-by-step derivation
            1. Applied rewrites99.7%

              \[\leadsto 0.5 \cdot e^{\left(\frac{-1}{v} + 0.6931\right) - \log v} \]
            2. Add Preprocessing

            Alternative 3: 99.5% accurate, 2.1× speedup?

            \[\begin{array}{l} \\ \frac{0.5}{v} \cdot e^{\frac{-1}{v} + 0.6931} \end{array} \]
            (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
             :precision binary32
             (* (/ 0.5 v) (exp (+ (/ -1.0 v) 0.6931))))
            float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
            	return (0.5f / v) * expf(((-1.0f / v) + 0.6931f));
            }
            
            real(4) function code(costheta_i, costheta_o, sintheta_i, sintheta_o, v)
                real(4), intent (in) :: costheta_i
                real(4), intent (in) :: costheta_o
                real(4), intent (in) :: sintheta_i
                real(4), intent (in) :: sintheta_o
                real(4), intent (in) :: v
                code = (0.5e0 / v) * exp((((-1.0e0) / v) + 0.6931e0))
            end function
            
            function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
            	return Float32(Float32(Float32(0.5) / v) * exp(Float32(Float32(Float32(-1.0) / v) + Float32(0.6931))))
            end
            
            function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
            	tmp = (single(0.5) / v) * exp(((single(-1.0) / v) + single(0.6931)));
            end
            
            \begin{array}{l}
            
            \\
            \frac{0.5}{v} \cdot e^{\frac{-1}{v} + 0.6931}
            \end{array}
            
            Derivation
            1. Initial program 99.6%

              \[e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)} \]
            2. Add Preprocessing
            3. Taylor expanded in sinTheta_i around 0

              \[\leadsto \color{blue}{e^{\left(\frac{6931}{10000} + \left(\log \left(\frac{\frac{1}{2}}{v}\right) + \frac{cosTheta\_O \cdot cosTheta\_i}{v}\right)\right) - \frac{1}{v}}} \]
            4. Step-by-step derivation
              1. associate-+r+N/A

                \[\leadsto e^{\color{blue}{\left(\left(\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)\right) + \frac{cosTheta\_O \cdot cosTheta\_i}{v}\right)} - \frac{1}{v}} \]
              2. associate--l+N/A

                \[\leadsto e^{\color{blue}{\left(\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)\right) + \left(\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}\right)}} \]
              3. exp-sumN/A

                \[\leadsto \color{blue}{e^{\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}}} \]
              4. lower-*.f32N/A

                \[\leadsto \color{blue}{e^{\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}}} \]
              5. +-commutativeN/A

                \[\leadsto e^{\color{blue}{\log \left(\frac{\frac{1}{2}}{v}\right) + \frac{6931}{10000}}} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
              6. exp-sumN/A

                \[\leadsto \color{blue}{\left(e^{\log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{6931}{10000}}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
              7. lower-*.f32N/A

                \[\leadsto \color{blue}{\left(e^{\log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{6931}{10000}}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
              8. rem-exp-logN/A

                \[\leadsto \left(\color{blue}{\frac{\frac{1}{2}}{v}} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
              9. lower-/.f32N/A

                \[\leadsto \left(\color{blue}{\frac{\frac{1}{2}}{v}} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
              10. lower-exp.f32N/A

                \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot \color{blue}{e^{\frac{6931}{10000}}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
              11. lower-exp.f32N/A

                \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot \color{blue}{e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}}} \]
              12. div-subN/A

                \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\color{blue}{\frac{cosTheta\_O \cdot cosTheta\_i - 1}{v}}} \]
              13. lower-/.f32N/A

                \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\color{blue}{\frac{cosTheta\_O \cdot cosTheta\_i - 1}{v}}} \]
              14. sub-negN/A

                \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{\color{blue}{cosTheta\_O \cdot cosTheta\_i + \left(\mathsf{neg}\left(1\right)\right)}}{v}} \]
              15. metadata-evalN/A

                \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i + \color{blue}{-1}}{v}} \]
              16. lower-fma.f3240.8

                \[\leadsto \left(\frac{0.5}{v} \cdot e^{0.6931}\right) \cdot e^{\frac{\color{blue}{\mathsf{fma}\left(cosTheta\_O, cosTheta\_i, -1\right)}}{v}} \]
            5. Applied rewrites40.8%

              \[\leadsto \color{blue}{\left(\frac{0.5}{v} \cdot e^{0.6931}\right) \cdot e^{\frac{\mathsf{fma}\left(cosTheta\_O, cosTheta\_i, -1\right)}{v}}} \]
            6. Taylor expanded in cosTheta_i around 0

              \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{-1}{v}} \]
            7. Step-by-step derivation
              1. Applied rewrites99.6%

                \[\leadsto \left(\frac{0.5}{v} \cdot e^{0.6931}\right) \cdot e^{\frac{-1}{v}} \]
              2. Step-by-step derivation
                1. Applied rewrites99.6%

                  \[\leadsto \frac{0.5}{v} \cdot \color{blue}{e^{\frac{-1}{v} + 0.6931}} \]
                2. Add Preprocessing

                Alternative 4: 99.7% accurate, 2.1× speedup?

                \[\begin{array}{l} \\ 0.5 \cdot \frac{e^{0.6931 + \frac{-1}{v}}}{v} \end{array} \]
                (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
                 :precision binary32
                 (* 0.5 (/ (exp (+ 0.6931 (/ -1.0 v))) v)))
                float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
                	return 0.5f * (expf((0.6931f + (-1.0f / v))) / v);
                }
                
                real(4) function code(costheta_i, costheta_o, sintheta_i, sintheta_o, v)
                    real(4), intent (in) :: costheta_i
                    real(4), intent (in) :: costheta_o
                    real(4), intent (in) :: sintheta_i
                    real(4), intent (in) :: sintheta_o
                    real(4), intent (in) :: v
                    code = 0.5e0 * (exp((0.6931e0 + ((-1.0e0) / v))) / v)
                end function
                
                function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
                	return Float32(Float32(0.5) * Float32(exp(Float32(Float32(0.6931) + Float32(Float32(-1.0) / v))) / v))
                end
                
                function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
                	tmp = single(0.5) * (exp((single(0.6931) + (single(-1.0) / v))) / v);
                end
                
                \begin{array}{l}
                
                \\
                0.5 \cdot \frac{e^{0.6931 + \frac{-1}{v}}}{v}
                \end{array}
                
                Derivation
                1. Initial program 99.6%

                  \[e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)} \]
                2. Add Preprocessing
                3. Taylor expanded in sinTheta_i around 0

                  \[\leadsto \color{blue}{e^{\left(\frac{6931}{10000} + \left(\log \left(\frac{\frac{1}{2}}{v}\right) + \frac{cosTheta\_O \cdot cosTheta\_i}{v}\right)\right) - \frac{1}{v}}} \]
                4. Step-by-step derivation
                  1. associate-+r+N/A

                    \[\leadsto e^{\color{blue}{\left(\left(\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)\right) + \frac{cosTheta\_O \cdot cosTheta\_i}{v}\right)} - \frac{1}{v}} \]
                  2. associate--l+N/A

                    \[\leadsto e^{\color{blue}{\left(\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)\right) + \left(\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}\right)}} \]
                  3. exp-sumN/A

                    \[\leadsto \color{blue}{e^{\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}}} \]
                  4. lower-*.f32N/A

                    \[\leadsto \color{blue}{e^{\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}}} \]
                  5. +-commutativeN/A

                    \[\leadsto e^{\color{blue}{\log \left(\frac{\frac{1}{2}}{v}\right) + \frac{6931}{10000}}} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
                  6. exp-sumN/A

                    \[\leadsto \color{blue}{\left(e^{\log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{6931}{10000}}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
                  7. lower-*.f32N/A

                    \[\leadsto \color{blue}{\left(e^{\log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{6931}{10000}}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
                  8. rem-exp-logN/A

                    \[\leadsto \left(\color{blue}{\frac{\frac{1}{2}}{v}} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
                  9. lower-/.f32N/A

                    \[\leadsto \left(\color{blue}{\frac{\frac{1}{2}}{v}} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
                  10. lower-exp.f32N/A

                    \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot \color{blue}{e^{\frac{6931}{10000}}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
                  11. lower-exp.f32N/A

                    \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot \color{blue}{e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}}} \]
                  12. div-subN/A

                    \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\color{blue}{\frac{cosTheta\_O \cdot cosTheta\_i - 1}{v}}} \]
                  13. lower-/.f32N/A

                    \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\color{blue}{\frac{cosTheta\_O \cdot cosTheta\_i - 1}{v}}} \]
                  14. sub-negN/A

                    \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{\color{blue}{cosTheta\_O \cdot cosTheta\_i + \left(\mathsf{neg}\left(1\right)\right)}}{v}} \]
                  15. metadata-evalN/A

                    \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i + \color{blue}{-1}}{v}} \]
                  16. lower-fma.f3240.4

                    \[\leadsto \left(\frac{0.5}{v} \cdot e^{0.6931}\right) \cdot e^{\frac{\color{blue}{\mathsf{fma}\left(cosTheta\_O, cosTheta\_i, -1\right)}}{v}} \]
                5. Applied rewrites40.8%

                  \[\leadsto \color{blue}{\left(\frac{0.5}{v} \cdot e^{0.6931}\right) \cdot e^{\frac{\mathsf{fma}\left(cosTheta\_O, cosTheta\_i, -1\right)}{v}}} \]
                6. Taylor expanded in cosTheta_i around 0

                  \[\leadsto \frac{1}{2} \cdot \color{blue}{\frac{e^{\frac{6931}{10000}} \cdot e^{\frac{-1}{v}}}{v}} \]
                7. Step-by-step derivation
                  1. Applied rewrites99.6%

                    \[\leadsto 0.5 \cdot \color{blue}{\frac{e^{0.6931 + \frac{-1}{v}}}{v}} \]
                  2. Add Preprocessing

                  Alternative 5: 98.2% accurate, 2.1× speedup?

                  \[\begin{array}{l} \\ 0.5 \cdot \frac{e^{\frac{-1}{v}}}{v} \end{array} \]
                  (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
                   :precision binary32
                   (* 0.5 (/ (exp (/ -1.0 v)) v)))
                  float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
                  	return 0.5f * (expf((-1.0f / v)) / v);
                  }
                  
                  real(4) function code(costheta_i, costheta_o, sintheta_i, sintheta_o, v)
                      real(4), intent (in) :: costheta_i
                      real(4), intent (in) :: costheta_o
                      real(4), intent (in) :: sintheta_i
                      real(4), intent (in) :: sintheta_o
                      real(4), intent (in) :: v
                      code = 0.5e0 * (exp(((-1.0e0) / v)) / v)
                  end function
                  
                  function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
                  	return Float32(Float32(0.5) * Float32(exp(Float32(Float32(-1.0) / v)) / v))
                  end
                  
                  function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
                  	tmp = single(0.5) * (exp((single(-1.0) / v)) / v);
                  end
                  
                  \begin{array}{l}
                  
                  \\
                  0.5 \cdot \frac{e^{\frac{-1}{v}}}{v}
                  \end{array}
                  
                  Derivation
                  1. Initial program 99.6%

                    \[e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)} \]
                  2. Add Preprocessing
                  3. Taylor expanded in sinTheta_i around 0

                    \[\leadsto \color{blue}{e^{\left(\frac{6931}{10000} + \left(\log \left(\frac{\frac{1}{2}}{v}\right) + \frac{cosTheta\_O \cdot cosTheta\_i}{v}\right)\right) - \frac{1}{v}}} \]
                  4. Step-by-step derivation
                    1. associate-+r+N/A

                      \[\leadsto e^{\color{blue}{\left(\left(\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)\right) + \frac{cosTheta\_O \cdot cosTheta\_i}{v}\right)} - \frac{1}{v}} \]
                    2. associate--l+N/A

                      \[\leadsto e^{\color{blue}{\left(\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)\right) + \left(\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}\right)}} \]
                    3. exp-sumN/A

                      \[\leadsto \color{blue}{e^{\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}}} \]
                    4. lower-*.f32N/A

                      \[\leadsto \color{blue}{e^{\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}}} \]
                    5. +-commutativeN/A

                      \[\leadsto e^{\color{blue}{\log \left(\frac{\frac{1}{2}}{v}\right) + \frac{6931}{10000}}} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
                    6. exp-sumN/A

                      \[\leadsto \color{blue}{\left(e^{\log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{6931}{10000}}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
                    7. lower-*.f32N/A

                      \[\leadsto \color{blue}{\left(e^{\log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{6931}{10000}}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
                    8. rem-exp-logN/A

                      \[\leadsto \left(\color{blue}{\frac{\frac{1}{2}}{v}} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
                    9. lower-/.f32N/A

                      \[\leadsto \left(\color{blue}{\frac{\frac{1}{2}}{v}} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
                    10. lower-exp.f32N/A

                      \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot \color{blue}{e^{\frac{6931}{10000}}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
                    11. lower-exp.f32N/A

                      \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot \color{blue}{e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}}} \]
                    12. div-subN/A

                      \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\color{blue}{\frac{cosTheta\_O \cdot cosTheta\_i - 1}{v}}} \]
                    13. lower-/.f32N/A

                      \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\color{blue}{\frac{cosTheta\_O \cdot cosTheta\_i - 1}{v}}} \]
                    14. sub-negN/A

                      \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{\color{blue}{cosTheta\_O \cdot cosTheta\_i + \left(\mathsf{neg}\left(1\right)\right)}}{v}} \]
                    15. metadata-evalN/A

                      \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i + \color{blue}{-1}}{v}} \]
                    16. lower-fma.f3240.4

                      \[\leadsto \left(\frac{0.5}{v} \cdot e^{0.6931}\right) \cdot e^{\frac{\color{blue}{\mathsf{fma}\left(cosTheta\_O, cosTheta\_i, -1\right)}}{v}} \]
                  5. Applied rewrites40.8%

                    \[\leadsto \color{blue}{\left(\frac{0.5}{v} \cdot e^{0.6931}\right) \cdot e^{\frac{\mathsf{fma}\left(cosTheta\_O, cosTheta\_i, -1\right)}{v}}} \]
                  6. Taylor expanded in cosTheta_i around 0

                    \[\leadsto \frac{1}{2} \cdot \color{blue}{\frac{e^{\frac{6931}{10000}} \cdot e^{\frac{-1}{v}}}{v}} \]
                  7. Step-by-step derivation
                    1. Applied rewrites99.6%

                      \[\leadsto 0.5 \cdot \color{blue}{\frac{e^{0.6931 + \frac{-1}{v}}}{v}} \]
                    2. Taylor expanded in v around 0

                      \[\leadsto \frac{1}{2} \cdot \frac{e^{\frac{-1}{v}}}{v} \]
                    3. Step-by-step derivation
                      1. Applied rewrites97.5%

                        \[\leadsto 0.5 \cdot \frac{e^{\frac{-1}{v}}}{v} \]
                      2. Add Preprocessing

                      Alternative 6: 98.0% accurate, 2.3× speedup?

                      \[\begin{array}{l} \\ 0.5 \cdot e^{\frac{-1}{v}} \end{array} \]
                      (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
                       :precision binary32
                       (* 0.5 (exp (/ -1.0 v))))
                      float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
                      	return 0.5f * expf((-1.0f / v));
                      }
                      
                      real(4) function code(costheta_i, costheta_o, sintheta_i, sintheta_o, v)
                          real(4), intent (in) :: costheta_i
                          real(4), intent (in) :: costheta_o
                          real(4), intent (in) :: sintheta_i
                          real(4), intent (in) :: sintheta_o
                          real(4), intent (in) :: v
                          code = 0.5e0 * exp(((-1.0e0) / v))
                      end function
                      
                      function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
                      	return Float32(Float32(0.5) * exp(Float32(Float32(-1.0) / v)))
                      end
                      
                      function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
                      	tmp = single(0.5) * exp((single(-1.0) / v));
                      end
                      
                      \begin{array}{l}
                      
                      \\
                      0.5 \cdot e^{\frac{-1}{v}}
                      \end{array}
                      
                      Derivation
                      1. Initial program 99.6%

                        \[e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)} \]
                      2. Add Preprocessing
                      3. Taylor expanded in sinTheta_i around 0

                        \[\leadsto \color{blue}{e^{\left(\frac{6931}{10000} + \left(\log \left(\frac{\frac{1}{2}}{v}\right) + \frac{cosTheta\_O \cdot cosTheta\_i}{v}\right)\right) - \frac{1}{v}}} \]
                      4. Step-by-step derivation
                        1. associate-+r+N/A

                          \[\leadsto e^{\color{blue}{\left(\left(\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)\right) + \frac{cosTheta\_O \cdot cosTheta\_i}{v}\right)} - \frac{1}{v}} \]
                        2. associate--l+N/A

                          \[\leadsto e^{\color{blue}{\left(\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)\right) + \left(\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}\right)}} \]
                        3. exp-sumN/A

                          \[\leadsto \color{blue}{e^{\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}}} \]
                        4. lower-*.f32N/A

                          \[\leadsto \color{blue}{e^{\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}}} \]
                        5. +-commutativeN/A

                          \[\leadsto e^{\color{blue}{\log \left(\frac{\frac{1}{2}}{v}\right) + \frac{6931}{10000}}} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
                        6. exp-sumN/A

                          \[\leadsto \color{blue}{\left(e^{\log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{6931}{10000}}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
                        7. lower-*.f32N/A

                          \[\leadsto \color{blue}{\left(e^{\log \left(\frac{\frac{1}{2}}{v}\right)} \cdot e^{\frac{6931}{10000}}\right)} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
                        8. rem-exp-logN/A

                          \[\leadsto \left(\color{blue}{\frac{\frac{1}{2}}{v}} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
                        9. lower-/.f32N/A

                          \[\leadsto \left(\color{blue}{\frac{\frac{1}{2}}{v}} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
                        10. lower-exp.f32N/A

                          \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot \color{blue}{e^{\frac{6931}{10000}}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
                        11. lower-exp.f32N/A

                          \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot \color{blue}{e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}}} \]
                        12. div-subN/A

                          \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\color{blue}{\frac{cosTheta\_O \cdot cosTheta\_i - 1}{v}}} \]
                        13. lower-/.f32N/A

                          \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\color{blue}{\frac{cosTheta\_O \cdot cosTheta\_i - 1}{v}}} \]
                        14. sub-negN/A

                          \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{\color{blue}{cosTheta\_O \cdot cosTheta\_i + \left(\mathsf{neg}\left(1\right)\right)}}{v}} \]
                        15. metadata-evalN/A

                          \[\leadsto \left(\frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i + \color{blue}{-1}}{v}} \]
                        16. lower-fma.f3240.8

                          \[\leadsto \left(\frac{0.5}{v} \cdot e^{0.6931}\right) \cdot e^{\frac{\color{blue}{\mathsf{fma}\left(cosTheta\_O, cosTheta\_i, -1\right)}}{v}} \]
                      5. Applied rewrites41.2%

                        \[\leadsto \color{blue}{\left(\frac{0.5}{v} \cdot e^{0.6931}\right) \cdot e^{\frac{\mathsf{fma}\left(cosTheta\_O, cosTheta\_i, -1\right)}{v}}} \]
                      6. Taylor expanded in cosTheta_i around 0

                        \[\leadsto \frac{1}{2} \cdot \color{blue}{\frac{e^{\frac{6931}{10000}} \cdot e^{\frac{-1}{v}}}{v}} \]
                      7. Step-by-step derivation
                        1. Applied rewrites99.6%

                          \[\leadsto 0.5 \cdot \color{blue}{\frac{e^{0.6931 + \frac{-1}{v}}}{v}} \]
                        2. Step-by-step derivation
                          1. Applied rewrites99.7%

                            \[\leadsto 0.5 \cdot e^{\left(\frac{-1}{v} + 0.6931\right) - \log v} \]
                          2. Taylor expanded in v around 0

                            \[\leadsto \frac{1}{2} \cdot e^{\frac{-1}{v}} \]
                          3. Step-by-step derivation
                            1. Applied rewrites97.2%

                              \[\leadsto 0.5 \cdot e^{\frac{-1}{v}} \]
                            2. Add Preprocessing

                            Reproduce

                            ?
                            herbie shell --seed 2024302 
                            (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
                              :name "HairBSDF, Mp, lower"
                              :precision binary32
                              :pre (and (and (and (and (and (<= -1.0 cosTheta_i) (<= cosTheta_i 1.0)) (and (<= -1.0 cosTheta_O) (<= cosTheta_O 1.0))) (and (<= -1.0 sinTheta_i) (<= sinTheta_i 1.0))) (and (<= -1.0 sinTheta_O) (<= sinTheta_O 1.0))) (and (<= -1.5707964 v) (<= v 0.1)))
                              (exp (+ (+ (- (- (/ (* cosTheta_i cosTheta_O) v) (/ (* sinTheta_i sinTheta_O) v)) (/ 1.0 v)) 0.6931) (log (/ 1.0 (* 2.0 v))))))