HairBSDF, Mp, lower

Percentage Accurate: 99.6% → 99.7%
Time: 5.1s
Alternatives: 7
Speedup: 1.8×

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)))));
}
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(costheta_i, costheta_o, sintheta_i, sintheta_o, v)
use fmin_fmax_functions
    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}

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: 99.6% 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)))));
}
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(costheta_i, costheta_o, sintheta_i, sintheta_o, v)
use fmin_fmax_functions
    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: 99.7% accurate, 1.4× speedup?

\[\begin{array}{l} \\ e^{\frac{\mathsf{fma}\left(0.6931 - \log \left(v + v\right), v, cosTheta\_O \cdot cosTheta\_i\right) - 1}{v}} \end{array} \]
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
 :precision binary32
 (exp
  (/ (- (fma (- 0.6931 (log (+ v v))) v (* cosTheta_O cosTheta_i)) 1.0) v)))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
	return expf(((fmaf((0.6931f - logf((v + v))), v, (cosTheta_O * cosTheta_i)) - 1.0f) / v));
}
function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
	return exp(Float32(Float32(fma(Float32(Float32(0.6931) - log(Float32(v + v))), v, Float32(cosTheta_O * cosTheta_i)) - Float32(1.0)) / v))
end
\begin{array}{l}

\\
e^{\frac{\mathsf{fma}\left(0.6931 - \log \left(v + v\right), v, cosTheta\_O \cdot cosTheta\_i\right) - 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. Taylor expanded in v around 0

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

      \[\leadsto e^{\frac{\left(cosTheta\_O \cdot cosTheta\_i + v \cdot \left(\frac{6931}{10000} + \left(\log \frac{1}{2} + -1 \cdot \log v\right)\right)\right) - \left(1 + sinTheta\_O \cdot sinTheta\_i\right)}{\color{blue}{v}}} \]
  4. Applied rewrites99.7%

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

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

      \[\leadsto e^{\frac{\mathsf{fma}\left(0.6931 - \log \left(v + v\right), v, cosTheta\_O \cdot cosTheta\_i\right) - 1}{v}} \]
    2. Add Preprocessing

    Alternative 2: 99.7% accurate, 1.4× speedup?

    \[\begin{array}{l} \\ e^{\frac{\mathsf{fma}\left(0.6931 - \log \left(v + v\right), v, \mathsf{fma}\left(cosTheta\_O, cosTheta\_i, -1\right)\right)}{v}} \end{array} \]
    (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
     :precision binary32
     (exp (/ (fma (- 0.6931 (log (+ v v))) v (fma cosTheta_O cosTheta_i -1.0)) v)))
    float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
    	return expf((fmaf((0.6931f - logf((v + v))), v, fmaf(cosTheta_O, cosTheta_i, -1.0f)) / v));
    }
    
    function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
    	return exp(Float32(fma(Float32(Float32(0.6931) - log(Float32(v + v))), v, fma(cosTheta_O, cosTheta_i, Float32(-1.0))) / v))
    end
    
    \begin{array}{l}
    
    \\
    e^{\frac{\mathsf{fma}\left(0.6931 - \log \left(v + v\right), v, \mathsf{fma}\left(cosTheta\_O, cosTheta\_i, -1\right)\right)}{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. Taylor expanded in v around 0

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

        \[\leadsto e^{\frac{\left(cosTheta\_O \cdot cosTheta\_i + v \cdot \left(\frac{6931}{10000} + \left(\log \frac{1}{2} + -1 \cdot \log v\right)\right)\right) - \left(1 + sinTheta\_O \cdot sinTheta\_i\right)}{\color{blue}{v}}} \]
    4. Applied rewrites99.7%

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

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

        \[\leadsto e^{\frac{\mathsf{fma}\left(0.6931 - \log \left(v + v\right), v, cosTheta\_O \cdot cosTheta\_i\right) - 1}{v}} \]
      2. Step-by-step derivation
        1. Applied rewrites99.7%

          \[\leadsto e^{\color{blue}{\frac{\mathsf{fma}\left(0.6931 - \log \left(v + v\right), v, \mathsf{fma}\left(cosTheta\_O, cosTheta\_i, -1\right)\right)}{v}}} \]
        2. Add Preprocessing

        Alternative 3: 99.7% accurate, 1.5× speedup?

        \[\begin{array}{l} \\ e^{\left(0.6931 - \log \left(v + v\right)\right) + \frac{\mathsf{fma}\left(cosTheta\_O, cosTheta\_i, -1\right)}{v}} \end{array} \]
        (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
         :precision binary32
         (exp (+ (- 0.6931 (log (+ v v))) (/ (fma cosTheta_O cosTheta_i -1.0) v))))
        float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
        	return expf(((0.6931f - logf((v + v))) + (fmaf(cosTheta_O, cosTheta_i, -1.0f) / v)));
        }
        
        function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
        	return exp(Float32(Float32(Float32(0.6931) - log(Float32(v + v))) + Float32(fma(cosTheta_O, cosTheta_i, Float32(-1.0)) / v)))
        end
        
        \begin{array}{l}
        
        \\
        e^{\left(0.6931 - \log \left(v + v\right)\right) + \frac{\mathsf{fma}\left(cosTheta\_O, cosTheta\_i, -1\right)}{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. Applied rewrites99.5%

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

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

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

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

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

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

            \[\leadsto e^{\left(\frac{6931}{10000} - \log \left(v + v\right)\right) + \frac{cosTheta\_O \cdot cosTheta\_i - 1}{v}} \]
          6. lift-log.f32N/A

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

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

            \[\leadsto e^{\left(\frac{6931}{10000} - \log \left(v + v\right)\right) + \frac{cosTheta\_O \cdot cosTheta\_i - 1}{v}} \]
          9. negate-subN/A

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

            \[\leadsto e^{\left(\frac{6931}{10000} - \log \left(v + v\right)\right) + \frac{cosTheta\_O \cdot cosTheta\_i + -1}{v}} \]
          11. lower-fma.f3299.7

            \[\leadsto e^{\left(0.6931 - \log \left(v + v\right)\right) + \frac{\mathsf{fma}\left(cosTheta\_O, cosTheta\_i, -1\right)}{v}} \]
        5. Applied rewrites99.7%

          \[\leadsto \color{blue}{e^{\left(0.6931 - \log \left(v + v\right)\right) + \frac{\mathsf{fma}\left(cosTheta\_O, cosTheta\_i, -1\right)}{v}}} \]
        6. Add Preprocessing

        Alternative 4: 99.7% accurate, 1.6× speedup?

        \[\begin{array}{l} \\ e^{\frac{\left(0.6931 - \log \left(v + v\right)\right) \cdot v - 1}{v}} \end{array} \]
        (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
         :precision binary32
         (exp (/ (- (* (- 0.6931 (log (+ v v))) v) 1.0) v)))
        float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
        	return expf(((((0.6931f - logf((v + v))) * v) - 1.0f) / v));
        }
        
        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(costheta_i, costheta_o, sintheta_i, sintheta_o, v)
        use fmin_fmax_functions
            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(((((0.6931e0 - log((v + v))) * v) - 1.0e0) / v))
        end function
        
        function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
        	return exp(Float32(Float32(Float32(Float32(Float32(0.6931) - log(Float32(v + v))) * v) - Float32(1.0)) / v))
        end
        
        function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
        	tmp = exp(((((single(0.6931) - log((v + v))) * v) - single(1.0)) / v));
        end
        
        \begin{array}{l}
        
        \\
        e^{\frac{\left(0.6931 - \log \left(v + v\right)\right) \cdot v - 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. Taylor expanded in v around 0

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

            \[\leadsto e^{\frac{\left(cosTheta\_O \cdot cosTheta\_i + v \cdot \left(\frac{6931}{10000} + \left(\log \frac{1}{2} + -1 \cdot \log v\right)\right)\right) - \left(1 + sinTheta\_O \cdot sinTheta\_i\right)}{\color{blue}{v}}} \]
        4. Applied rewrites99.7%

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

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

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

            \[\leadsto e^{\frac{v \cdot \left(\frac{6931}{10000} - \log \left(2 \cdot v\right)\right) - 1}{v}} \]
          3. Step-by-step derivation
            1. *-commutativeN/A

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

              \[\leadsto e^{\frac{\left(\frac{6931}{10000} - \log \left(2 \cdot v\right)\right) \cdot v - 1}{v}} \]
            3. lower--.f32N/A

              \[\leadsto e^{\frac{\left(\frac{6931}{10000} - \log \left(2 \cdot v\right)\right) \cdot v - 1}{v}} \]
            4. count-2-revN/A

              \[\leadsto e^{\frac{\left(\frac{6931}{10000} - \log \left(v + v\right)\right) \cdot v - 1}{v}} \]
            5. lift-log.f32N/A

              \[\leadsto e^{\frac{\left(\frac{6931}{10000} - \log \left(v + v\right)\right) \cdot v - 1}{v}} \]
            6. lift-+.f3299.7

              \[\leadsto e^{\frac{\left(0.6931 - \log \left(v + v\right)\right) \cdot v - 1}{v}} \]
          4. Applied rewrites99.7%

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

          Alternative 5: 99.7% accurate, 1.6× speedup?

          \[\begin{array}{l} \\ e^{\frac{\mathsf{fma}\left(0.6931 - \log \left(v + v\right), v, -1\right)}{v}} \end{array} \]
          (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
           :precision binary32
           (exp (/ (fma (- 0.6931 (log (+ v v))) v -1.0) v)))
          float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
          	return expf((fmaf((0.6931f - logf((v + v))), v, -1.0f) / v));
          }
          
          function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
          	return exp(Float32(fma(Float32(Float32(0.6931) - log(Float32(v + v))), v, Float32(-1.0)) / v))
          end
          
          \begin{array}{l}
          
          \\
          e^{\frac{\mathsf{fma}\left(0.6931 - \log \left(v + v\right), v, -1\right)}{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. Taylor expanded in v around 0

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

              \[\leadsto e^{\frac{\left(cosTheta\_O \cdot cosTheta\_i + v \cdot \left(\frac{6931}{10000} + \left(\log \frac{1}{2} + -1 \cdot \log v\right)\right)\right) - \left(1 + sinTheta\_O \cdot sinTheta\_i\right)}{\color{blue}{v}}} \]
          4. Applied rewrites99.7%

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

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

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

              \[\leadsto e^{\frac{v \cdot \left(\frac{6931}{10000} - \log \left(2 \cdot v\right)\right) - 1}{v}} \]
            3. Step-by-step derivation
              1. negate-subN/A

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

                \[\leadsto e^{\frac{v \cdot \left(\frac{6931}{10000} - \log \left(2 \cdot v\right)\right) + -1}{v}} \]
              3. *-commutativeN/A

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

                \[\leadsto e^{\frac{\mathsf{fma}\left(\frac{6931}{10000} - \log \left(2 \cdot v\right), v, -1\right)}{v}} \]
              5. lower--.f32N/A

                \[\leadsto e^{\frac{\mathsf{fma}\left(\frac{6931}{10000} - \log \left(2 \cdot v\right), v, -1\right)}{v}} \]
              6. count-2-revN/A

                \[\leadsto e^{\frac{\mathsf{fma}\left(\frac{6931}{10000} - \log \left(v + v\right), v, -1\right)}{v}} \]
              7. lift-log.f32N/A

                \[\leadsto e^{\frac{\mathsf{fma}\left(\frac{6931}{10000} - \log \left(v + v\right), v, -1\right)}{v}} \]
              8. lift-+.f3299.7

                \[\leadsto e^{\frac{\mathsf{fma}\left(0.6931 - \log \left(v + v\right), v, -1\right)}{v}} \]
            4. Applied rewrites99.7%

              \[\leadsto e^{\frac{\mathsf{fma}\left(0.6931 - \log \left(v + v\right), v, -1\right)}{v}} \]
            5. Add Preprocessing

            Alternative 6: 99.7% accurate, 1.8× speedup?

            \[\begin{array}{l} \\ e^{\left(0.6931 - \log \left(v + v\right)\right) - \frac{1}{v}} \end{array} \]
            (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
             :precision binary32
             (exp (- (- 0.6931 (log (+ v v))) (/ 1.0 v))))
            float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
            	return expf(((0.6931f - logf((v + v))) - (1.0f / v)));
            }
            
            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(costheta_i, costheta_o, sintheta_i, sintheta_o, v)
            use fmin_fmax_functions
                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(((0.6931e0 - log((v + v))) - (1.0e0 / v)))
            end function
            
            function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
            	return exp(Float32(Float32(Float32(0.6931) - log(Float32(v + v))) - Float32(Float32(1.0) / v)))
            end
            
            function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
            	tmp = exp(((single(0.6931) - log((v + v))) - (single(1.0) / v)));
            end
            
            \begin{array}{l}
            
            \\
            e^{\left(0.6931 - \log \left(v + v\right)\right) - \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. Taylor expanded in cosTheta_i around 0

              \[\leadsto e^{\color{blue}{\left(\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)\right) - \left(\frac{1}{v} + \frac{sinTheta\_O \cdot sinTheta\_i}{v}\right)}} \]
            3. Step-by-step derivation
              1. lower--.f32N/A

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

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

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

                \[\leadsto e^{\left(\log \left(\frac{\frac{1}{2}}{v}\right) + \frac{6931}{10000}\right) - \left(\frac{1}{v} + \frac{sinTheta\_O \cdot sinTheta\_i}{v}\right)} \]
              5. associate-/r*N/A

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

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

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

                \[\leadsto e^{\left(\left(-\log \left(2 \cdot v\right)\right) + \frac{6931}{10000}\right) - \left(\frac{1}{v} + \frac{sinTheta\_O \cdot sinTheta\_i}{v}\right)} \]
              9. count-2-revN/A

                \[\leadsto e^{\left(\left(-\log \left(v + v\right)\right) + \frac{6931}{10000}\right) - \left(\frac{1}{v} + \frac{sinTheta\_O \cdot sinTheta\_i}{v}\right)} \]
              10. lower-+.f32N/A

                \[\leadsto e^{\left(\left(-\log \left(v + v\right)\right) + \frac{6931}{10000}\right) - \left(\frac{1}{v} + \frac{sinTheta\_O \cdot sinTheta\_i}{v}\right)} \]
              11. div-add-revN/A

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

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

                \[\leadsto e^{\left(\left(-\log \left(v + v\right)\right) + \frac{6931}{10000}\right) - \frac{sinTheta\_O \cdot sinTheta\_i + 1}{v}} \]
              14. lower-fma.f3299.7

                \[\leadsto e^{\left(\left(-\log \left(v + v\right)\right) + 0.6931\right) - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}} \]
            4. Applied rewrites99.7%

              \[\leadsto e^{\color{blue}{\left(\left(-\log \left(v + v\right)\right) + 0.6931\right) - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}}} \]
            5. Taylor expanded in sinTheta_i around 0

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

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

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

                \[\leadsto e^{\left(\frac{6931}{10000} - \log \left(2 \cdot v\right)\right) - \frac{1}{v}} \]
              4. count-2-revN/A

                \[\leadsto e^{\left(\frac{6931}{10000} - \log \left(v + v\right)\right) - \frac{1}{v}} \]
              5. lift-log.f32N/A

                \[\leadsto e^{\left(\frac{6931}{10000} - \log \left(v + v\right)\right) - \frac{1}{v}} \]
              6. lift-+.f32N/A

                \[\leadsto e^{\left(\frac{6931}{10000} - \log \left(v + v\right)\right) - \frac{1}{v}} \]
              7. lower-/.f3299.7

                \[\leadsto e^{\left(0.6931 - \log \left(v + v\right)\right) - \frac{1}{v}} \]
            7. Applied rewrites99.7%

              \[\leadsto e^{\left(0.6931 - \log \left(v + v\right)\right) - \color{blue}{\frac{1}{v}}} \]
            8. Add Preprocessing

            Alternative 7: 97.8% accurate, 3.3× speedup?

            \[\begin{array}{l} \\ e^{\frac{-1}{v}} \end{array} \]
            (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
             :precision binary32
             (exp (/ -1.0 v)))
            float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
            	return expf((-1.0f / v));
            }
            
            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(costheta_i, costheta_o, sintheta_i, sintheta_o, v)
            use fmin_fmax_functions
                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(((-1.0e0) / v))
            end function
            
            function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
            	return exp(Float32(Float32(-1.0) / v))
            end
            
            function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
            	tmp = exp((single(-1.0) / v));
            end
            
            \begin{array}{l}
            
            \\
            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. Taylor expanded in cosTheta_i around 0

              \[\leadsto e^{\color{blue}{\left(\frac{6931}{10000} + \log \left(\frac{\frac{1}{2}}{v}\right)\right) - \left(\frac{1}{v} + \frac{sinTheta\_O \cdot sinTheta\_i}{v}\right)}} \]
            3. Step-by-step derivation
              1. lower--.f32N/A

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

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

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

                \[\leadsto e^{\left(\log \left(\frac{\frac{1}{2}}{v}\right) + \frac{6931}{10000}\right) - \left(\frac{1}{v} + \frac{sinTheta\_O \cdot sinTheta\_i}{v}\right)} \]
              5. associate-/r*N/A

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

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

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

                \[\leadsto e^{\left(\left(-\log \left(2 \cdot v\right)\right) + \frac{6931}{10000}\right) - \left(\frac{1}{v} + \frac{sinTheta\_O \cdot sinTheta\_i}{v}\right)} \]
              9. count-2-revN/A

                \[\leadsto e^{\left(\left(-\log \left(v + v\right)\right) + \frac{6931}{10000}\right) - \left(\frac{1}{v} + \frac{sinTheta\_O \cdot sinTheta\_i}{v}\right)} \]
              10. lower-+.f32N/A

                \[\leadsto e^{\left(\left(-\log \left(v + v\right)\right) + \frac{6931}{10000}\right) - \left(\frac{1}{v} + \frac{sinTheta\_O \cdot sinTheta\_i}{v}\right)} \]
              11. div-add-revN/A

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

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

                \[\leadsto e^{\left(\left(-\log \left(v + v\right)\right) + \frac{6931}{10000}\right) - \frac{sinTheta\_O \cdot sinTheta\_i + 1}{v}} \]
              14. lower-fma.f3299.7

                \[\leadsto e^{\left(\left(-\log \left(v + v\right)\right) + 0.6931\right) - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}} \]
            4. Applied rewrites99.7%

              \[\leadsto e^{\color{blue}{\left(\left(-\log \left(v + v\right)\right) + 0.6931\right) - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}}} \]
            5. Taylor expanded in sinTheta_i around 0

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

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

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

                \[\leadsto e^{\left(\frac{6931}{10000} - \log \left(2 \cdot v\right)\right) - \frac{1}{v}} \]
              4. count-2-revN/A

                \[\leadsto e^{\left(\frac{6931}{10000} - \log \left(v + v\right)\right) - \frac{1}{v}} \]
              5. lift-log.f32N/A

                \[\leadsto e^{\left(\frac{6931}{10000} - \log \left(v + v\right)\right) - \frac{1}{v}} \]
              6. lift-+.f32N/A

                \[\leadsto e^{\left(\frac{6931}{10000} - \log \left(v + v\right)\right) - \frac{1}{v}} \]
              7. lower-/.f3299.7

                \[\leadsto e^{\left(0.6931 - \log \left(v + v\right)\right) - \frac{1}{v}} \]
            7. Applied rewrites99.7%

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

              \[\leadsto e^{\frac{-1}{v}} \]
            9. Step-by-step derivation
              1. lower-/.f3297.8

                \[\leadsto e^{\frac{-1}{v}} \]
            10. Applied rewrites97.8%

              \[\leadsto e^{\frac{-1}{v}} \]
            11. Add Preprocessing

            Reproduce

            ?
            herbie shell --seed 2025119 
            (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))))))