HairBSDF, Mp, lower

Percentage Accurate: 99.7% → 99.7%
Time: 10.4s
Alternatives: 7
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)))));
}
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}

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 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: 99.7% 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, 0.6× speedup?

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

\\
\begin{array}{l}
t_0 := \log \left(2 \cdot v\right)\\
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) - \frac{{t\_0}^{2}}{t\_0}}
\end{array}
\end{array}
Derivation
  1. Initial program 99.3%

    \[e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-log.f32N/A

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

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

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

      \[\leadsto e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + \frac{6931}{10000}\right) + \left(\color{blue}{0} - \log \left(2 \cdot v\right)\right)} \]
    5. flip--N/A

      \[\leadsto e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + \frac{6931}{10000}\right) + \color{blue}{\frac{0 \cdot 0 - \log \left(2 \cdot v\right) \cdot \log \left(2 \cdot v\right)}{0 + \log \left(2 \cdot v\right)}}} \]
    6. lower-/.f32N/A

      \[\leadsto e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + \frac{6931}{10000}\right) + \color{blue}{\frac{0 \cdot 0 - \log \left(2 \cdot v\right) \cdot \log \left(2 \cdot v\right)}{0 + \log \left(2 \cdot v\right)}}} \]
  4. Applied rewrites99.7%

    \[\leadsto e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \color{blue}{\frac{0 - {\log \left(2 \cdot v\right)}^{2}}{0 + \log \left(2 \cdot v\right)}}} \]
  5. Final simplification99.7%

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

Alternative 2: 99.7% accurate, 2.1× speedup?

\[\begin{array}{l} \\ \frac{e^{\frac{-1}{v} + 0.6931}}{v} \cdot 0.5 \end{array} \]
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
 :precision binary32
 (* (/ (exp (+ (/ -1.0 v) 0.6931)) v) 0.5))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
	return (expf(((-1.0f / v) + 0.6931f)) / v) * 0.5f;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

real(4) function code(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) + 0.6931e0)) / v) * 0.5e0
end function
function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
	return Float32(Float32(exp(Float32(Float32(Float32(-1.0) / v) + Float32(0.6931))) / v) * Float32(0.5))
end
function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
	tmp = (exp(((single(-1.0) / v) + single(0.6931))) / v) * single(0.5);
end
\begin{array}{l}

\\
\frac{e^{\frac{-1}{v} + 0.6931}}{v} \cdot 0.5
\end{array}
Derivation
  1. Initial program 99.3%

    \[e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)} \]
  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. exp-sumN/A

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

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

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

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

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

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

      \[\leadsto \left(e^{\frac{6931}{10000}} \cdot \color{blue}{e^{\log \frac{1}{2} - \left(\mathsf{neg}\left(-1\right)\right) \cdot \log v}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
    11. fp-cancel-sign-sub-invN/A

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

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

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

      \[\leadsto \color{blue}{e^{\frac{6931}{10000} + \left(\log \frac{1}{2} + \log \left(\frac{1}{v}\right)\right)}} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
  5. Applied rewrites99.3%

    \[\leadsto \color{blue}{\left(\frac{0.5}{v} \cdot e^{0.6931}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i - 1}{v}}} \]
  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 rewrites99.7%

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

    Alternative 3: 99.6% accurate, 2.1× speedup?

    \[\begin{array}{l} \\ e^{\frac{-1}{v} + 0.6931} \cdot \frac{0.5}{v} \end{array} \]
    (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
     :precision binary32
     (* (exp (+ (/ -1.0 v) 0.6931)) (/ 0.5 v)))
    float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
    	return expf(((-1.0f / v) + 0.6931f)) * (0.5f / 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) + 0.6931e0)) * (0.5e0 / v)
    end function
    
    function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
    	return Float32(exp(Float32(Float32(Float32(-1.0) / v) + Float32(0.6931))) * Float32(Float32(0.5) / v))
    end
    
    function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
    	tmp = exp(((single(-1.0) / v) + single(0.6931))) * (single(0.5) / v);
    end
    
    \begin{array}{l}
    
    \\
    e^{\frac{-1}{v} + 0.6931} \cdot \frac{0.5}{v}
    \end{array}
    
    Derivation
    1. Initial program 99.3%

      \[e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)} \]
    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. exp-sumN/A

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

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

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

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

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

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

        \[\leadsto \left(e^{\frac{6931}{10000}} \cdot \color{blue}{e^{\log \frac{1}{2} - \left(\mathsf{neg}\left(-1\right)\right) \cdot \log v}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
      11. fp-cancel-sign-sub-invN/A

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

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

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

        \[\leadsto \color{blue}{e^{\frac{6931}{10000} + \left(\log \frac{1}{2} + \log \left(\frac{1}{v}\right)\right)}} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
    5. Applied rewrites99.3%

      \[\leadsto \color{blue}{\left(\frac{0.5}{v} \cdot e^{0.6931}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i - 1}{v}}} \]
    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 rewrites99.7%

        \[\leadsto \frac{e^{\frac{-1}{v} + 0.6931}}{v} \cdot \color{blue}{0.5} \]
      2. Step-by-step derivation
        1. Applied rewrites99.3%

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

        Alternative 4: 98.1% accurate, 2.1× speedup?

        \[\begin{array}{l} \\ \frac{e^{\frac{-1}{v}}}{v} \cdot 0.5 \end{array} \]
        (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
         :precision binary32
         (* (/ (exp (/ -1.0 v)) v) 0.5))
        float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
        	return (expf((-1.0f / v)) / v) * 0.5f;
        }
        
        module fmin_fmax_functions
            implicit none
            private
            public fmax
            public fmin
        
            interface fmax
                module procedure fmax88
                module procedure fmax44
                module procedure fmax84
                module procedure fmax48
            end interface
            interface fmin
                module procedure fmin88
                module procedure fmin44
                module procedure fmin84
                module procedure fmin48
            end interface
        contains
            real(8) function fmax88(x, y) result (res)
                real(8), intent (in) :: x
                real(8), intent (in) :: y
                res = merge(y, merge(x, max(x, y), y /= y), x /= x)
            end function
            real(4) function fmax44(x, y) result (res)
                real(4), intent (in) :: x
                real(4), intent (in) :: y
                res = merge(y, merge(x, max(x, y), y /= y), x /= x)
            end function
            real(8) function fmax84(x, y) result(res)
                real(8), intent (in) :: x
                real(4), intent (in) :: y
                res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
            end function
            real(8) function fmax48(x, y) result(res)
                real(4), intent (in) :: x
                real(8), intent (in) :: y
                res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
            end function
            real(8) function fmin88(x, y) result (res)
                real(8), intent (in) :: x
                real(8), intent (in) :: y
                res = merge(y, merge(x, min(x, y), y /= y), x /= x)
            end function
            real(4) function fmin44(x, y) result (res)
                real(4), intent (in) :: x
                real(4), intent (in) :: y
                res = merge(y, merge(x, min(x, y), y /= y), x /= x)
            end function
            real(8) function fmin84(x, y) result(res)
                real(8), intent (in) :: x
                real(4), intent (in) :: y
                res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
            end function
            real(8) function fmin48(x, y) result(res)
                real(4), intent (in) :: x
                real(8), intent (in) :: y
                res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
            end function
        end module
        
        real(4) function code(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)) / v) * 0.5e0
        end function
        
        function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
        	return Float32(Float32(exp(Float32(Float32(-1.0) / v)) / v) * Float32(0.5))
        end
        
        function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
        	tmp = (exp((single(-1.0) / v)) / v) * single(0.5);
        end
        
        \begin{array}{l}
        
        \\
        \frac{e^{\frac{-1}{v}}}{v} \cdot 0.5
        \end{array}
        
        Derivation
        1. Initial program 99.3%

          \[e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)} \]
        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. exp-sumN/A

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

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

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

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

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

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

            \[\leadsto \left(e^{\frac{6931}{10000}} \cdot \color{blue}{e^{\log \frac{1}{2} - \left(\mathsf{neg}\left(-1\right)\right) \cdot \log v}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
          11. fp-cancel-sign-sub-invN/A

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

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

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

            \[\leadsto \color{blue}{e^{\frac{6931}{10000} + \left(\log \frac{1}{2} + \log \left(\frac{1}{v}\right)\right)}} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
        5. Applied rewrites99.3%

          \[\leadsto \color{blue}{\left(\frac{0.5}{v} \cdot e^{0.6931}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i - 1}{v}}} \]
        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 rewrites99.7%

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

            \[\leadsto \frac{e^{\frac{-1}{v}}}{v} \cdot \frac{1}{2} \]
          3. Step-by-step derivation
            1. Applied rewrites98.0%

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

            Alternative 5: 97.9% accurate, 2.4× 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 99.3%

              \[e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)} \]
            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. exp-sumN/A

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

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

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

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

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

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

                \[\leadsto \left(e^{\frac{6931}{10000}} \cdot \color{blue}{e^{\log \frac{1}{2} - \left(\mathsf{neg}\left(-1\right)\right) \cdot \log v}}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
              11. fp-cancel-sign-sub-invN/A

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

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

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

                \[\leadsto \color{blue}{e^{\frac{6931}{10000} + \left(\log \frac{1}{2} + \log \left(\frac{1}{v}\right)\right)}} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v} - \frac{1}{v}} \]
            5. Applied rewrites99.3%

              \[\leadsto \color{blue}{\left(\frac{0.5}{v} \cdot e^{0.6931}\right) \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i - 1}{v}}} \]
            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 rewrites99.7%

                \[\leadsto \frac{e^{\frac{-1}{v} + 0.6931}}{v} \cdot \color{blue}{0.5} \]
              2. Step-by-step derivation
                1. Applied rewrites99.3%

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

                  \[\leadsto e^{\frac{-1}{v}} \]
                3. Step-by-step derivation
                  1. Applied rewrites97.8%

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

                  Alternative 6: 10.7% accurate, 2.5× speedup?

                  \[\begin{array}{l} \\ \left(e^{0.6931} \cdot v\right) \cdot 2 \end{array} \]
                  (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
                   :precision binary32
                   (* (* (exp 0.6931) v) 2.0))
                  float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
                  	return (expf(0.6931f) * v) * 2.0f;
                  }
                  
                  module fmin_fmax_functions
                      implicit none
                      private
                      public fmax
                      public fmin
                  
                      interface fmax
                          module procedure fmax88
                          module procedure fmax44
                          module procedure fmax84
                          module procedure fmax48
                      end interface
                      interface fmin
                          module procedure fmin88
                          module procedure fmin44
                          module procedure fmin84
                          module procedure fmin48
                      end interface
                  contains
                      real(8) function fmax88(x, y) result (res)
                          real(8), intent (in) :: x
                          real(8), intent (in) :: y
                          res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                      end function
                      real(4) function fmax44(x, y) result (res)
                          real(4), intent (in) :: x
                          real(4), intent (in) :: y
                          res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                      end function
                      real(8) function fmax84(x, y) result(res)
                          real(8), intent (in) :: x
                          real(4), intent (in) :: y
                          res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                      end function
                      real(8) function fmax48(x, y) result(res)
                          real(4), intent (in) :: x
                          real(8), intent (in) :: y
                          res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                      end function
                      real(8) function fmin88(x, y) result (res)
                          real(8), intent (in) :: x
                          real(8), intent (in) :: y
                          res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                      end function
                      real(4) function fmin44(x, y) result (res)
                          real(4), intent (in) :: x
                          real(4), intent (in) :: y
                          res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                      end function
                      real(8) function fmin84(x, y) result(res)
                          real(8), intent (in) :: x
                          real(4), intent (in) :: y
                          res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                      end function
                      real(8) function fmin48(x, y) result(res)
                          real(4), intent (in) :: x
                          real(8), intent (in) :: y
                          res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                      end function
                  end module
                  
                  real(4) function code(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) * v) * 2.0e0
                  end function
                  
                  function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
                  	return Float32(Float32(exp(Float32(0.6931)) * v) * Float32(2.0))
                  end
                  
                  function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
                  	tmp = (exp(single(0.6931)) * v) * single(2.0);
                  end
                  
                  \begin{array}{l}
                  
                  \\
                  \left(e^{0.6931} \cdot v\right) \cdot 2
                  \end{array}
                  
                  Derivation
                  1. Initial program 99.3%

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

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

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

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

                      \[\leadsto e^{\log \frac{1}{2} + \color{blue}{\left(\mathsf{neg}\left(\log v\right)\right)}} \cdot e^{\frac{6931}{10000}} \]
                    4. mul-1-negN/A

                      \[\leadsto e^{\log \frac{1}{2} + \color{blue}{-1 \cdot \log v}} \cdot e^{\frac{6931}{10000}} \]
                    5. fp-cancel-sign-sub-invN/A

                      \[\leadsto e^{\color{blue}{\log \frac{1}{2} - \left(\mathsf{neg}\left(-1\right)\right) \cdot \log v}} \cdot e^{\frac{6931}{10000}} \]
                    6. exp-diffN/A

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

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

                      \[\leadsto \frac{\frac{1}{2}}{e^{\color{blue}{1} \cdot \log v}} \cdot e^{\frac{6931}{10000}} \]
                    9. *-lft-identityN/A

                      \[\leadsto \frac{\frac{1}{2}}{e^{\color{blue}{\log v}}} \cdot e^{\frac{6931}{10000}} \]
                    10. rem-exp-logN/A

                      \[\leadsto \frac{\frac{1}{2}}{\color{blue}{v}} \cdot e^{\frac{6931}{10000}} \]
                    11. rem-exp-logN/A

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

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

                      \[\leadsto \color{blue}{\frac{\frac{1}{2}}{v}} \cdot e^{\frac{6931}{10000}} \]
                    14. lower-/.f32N/A

                      \[\leadsto \color{blue}{\frac{\frac{1}{2}}{v}} \cdot e^{\frac{6931}{10000}} \]
                    15. lower-exp.f324.6

                      \[\leadsto \frac{0.5}{v} \cdot \color{blue}{e^{0.6931}} \]
                  5. Applied rewrites4.6%

                    \[\leadsto \color{blue}{\frac{0.5}{v} \cdot e^{0.6931}} \]
                  6. Step-by-step derivation
                    1. Applied rewrites10.6%

                      \[\leadsto \left(v + v\right) \cdot e^{\color{blue}{0.6931}} \]
                    2. Step-by-step derivation
                      1. Applied rewrites10.6%

                        \[\leadsto \left(e^{0.6931} \cdot v\right) \cdot \color{blue}{2} \]
                      2. Add Preprocessing

                      Alternative 7: 10.7% accurate, 2.5× speedup?

                      \[\begin{array}{l} \\ \left(v + v\right) \cdot e^{0.6931} \end{array} \]
                      (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
                       :precision binary32
                       (* (+ v v) (exp 0.6931)))
                      float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
                      	return (v + v) * expf(0.6931f);
                      }
                      
                      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 = (v + v) * exp(0.6931e0)
                      end function
                      
                      function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
                      	return Float32(Float32(v + v) * exp(Float32(0.6931)))
                      end
                      
                      function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
                      	tmp = (v + v) * exp(single(0.6931));
                      end
                      
                      \begin{array}{l}
                      
                      \\
                      \left(v + v\right) \cdot e^{0.6931}
                      \end{array}
                      
                      Derivation
                      1. Initial program 99.3%

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

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

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

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

                          \[\leadsto e^{\log \frac{1}{2} + \color{blue}{\left(\mathsf{neg}\left(\log v\right)\right)}} \cdot e^{\frac{6931}{10000}} \]
                        4. mul-1-negN/A

                          \[\leadsto e^{\log \frac{1}{2} + \color{blue}{-1 \cdot \log v}} \cdot e^{\frac{6931}{10000}} \]
                        5. fp-cancel-sign-sub-invN/A

                          \[\leadsto e^{\color{blue}{\log \frac{1}{2} - \left(\mathsf{neg}\left(-1\right)\right) \cdot \log v}} \cdot e^{\frac{6931}{10000}} \]
                        6. exp-diffN/A

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

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

                          \[\leadsto \frac{\frac{1}{2}}{e^{\color{blue}{1} \cdot \log v}} \cdot e^{\frac{6931}{10000}} \]
                        9. *-lft-identityN/A

                          \[\leadsto \frac{\frac{1}{2}}{e^{\color{blue}{\log v}}} \cdot e^{\frac{6931}{10000}} \]
                        10. rem-exp-logN/A

                          \[\leadsto \frac{\frac{1}{2}}{\color{blue}{v}} \cdot e^{\frac{6931}{10000}} \]
                        11. rem-exp-logN/A

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

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

                          \[\leadsto \color{blue}{\frac{\frac{1}{2}}{v}} \cdot e^{\frac{6931}{10000}} \]
                        14. lower-/.f32N/A

                          \[\leadsto \color{blue}{\frac{\frac{1}{2}}{v}} \cdot e^{\frac{6931}{10000}} \]
                        15. lower-exp.f324.6

                          \[\leadsto \frac{0.5}{v} \cdot \color{blue}{e^{0.6931}} \]
                      5. Applied rewrites4.6%

                        \[\leadsto \color{blue}{\frac{0.5}{v} \cdot e^{0.6931}} \]
                      6. Step-by-step derivation
                        1. Applied rewrites10.6%

                          \[\leadsto \left(v + v\right) \cdot e^{\color{blue}{0.6931}} \]
                        2. Add Preprocessing

                        Reproduce

                        ?
                        herbie shell --seed 2024359 
                        (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))))))