HairBSDF, Mp, lower

Percentage Accurate: 99.6% → 99.7%
Time: 4.7s
Alternatives: 12
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}

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 12 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, 1.1× speedup?

\[\begin{array}{l} \\ e^{\frac{\mathsf{fma}\left(\log \left(\frac{0.5}{v}\right) + 0.6931, v, cosTheta\_O \cdot cosTheta\_i\right) - \mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}} \end{array} \]
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
 :precision binary32
 (exp
  (/
   (-
    (fma (+ (log (/ 0.5 v)) 0.6931) v (* cosTheta_O cosTheta_i))
    (fma sinTheta_O sinTheta_i 1.0))
   v)))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
	return expf(((fmaf((logf((0.5f / v)) + 0.6931f), v, (cosTheta_O * cosTheta_i)) - fmaf(sinTheta_O, sinTheta_i, 1.0f)) / v));
}
function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
	return exp(Float32(Float32(fma(Float32(log(Float32(Float32(0.5) / v)) + Float32(0.6931)), v, Float32(cosTheta_O * cosTheta_i)) - fma(sinTheta_O, sinTheta_i, Float32(1.0))) / v))
end
\begin{array}{l}

\\
e^{\frac{\mathsf{fma}\left(\log \left(\frac{0.5}{v}\right) + 0.6931, v, cosTheta\_O \cdot cosTheta\_i\right) - \mathsf{fma}\left(sinTheta\_O, sinTheta\_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. Add Preprocessing
  3. Taylor expanded in v around 0

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

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

    \[\leadsto e^{\color{blue}{\frac{\mathsf{fma}\left(\log \left(\frac{0.5}{v}\right) + 0.6931, v, cosTheta\_O \cdot cosTheta\_i\right) - \mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}}} \]
  6. Add Preprocessing

Alternative 2: 99.6% accurate, 1.2× speedup?

\[\begin{array}{l} \\ e^{\left(\log \left(\frac{0.5}{v}\right) + 0.6931\right) - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}} \end{array} \]
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
 :precision binary32
 (exp (- (+ (log (/ 0.5 v)) 0.6931) (/ (fma sinTheta_O sinTheta_i 1.0) v))))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
	return expf(((logf((0.5f / v)) + 0.6931f) - (fmaf(sinTheta_O, sinTheta_i, 1.0f) / v)));
}
function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
	return exp(Float32(Float32(log(Float32(Float32(0.5) / v)) + Float32(0.6931)) - Float32(fma(sinTheta_O, sinTheta_i, Float32(1.0)) / v)))
end
\begin{array}{l}

\\
e^{\left(\log \left(\frac{0.5}{v}\right) + 0.6931\right) - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_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. Add Preprocessing
  3. Taylor expanded in cosTheta_i around 0

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

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

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

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

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

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

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

      \[\leadsto e^{\left(\log \left(\frac{\frac{1}{2}}{v}\right) + \frac{6931}{10000}\right) - \frac{sinTheta\_O \cdot sinTheta\_i + 1}{v}} \]
    13. lower-fma.f3299.6

      \[\leadsto e^{\left(\log \left(\frac{0.5}{v}\right) + 0.6931\right) - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}} \]
  5. Applied rewrites99.6%

    \[\leadsto e^{\color{blue}{\left(\log \left(\frac{0.5}{v}\right) + 0.6931\right) - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}}} \]
  6. Add Preprocessing

Alternative 3: 99.6% accurate, 1.7× speedup?

\[\begin{array}{l} \\ \frac{0.5}{v} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i - sinTheta\_O \cdot sinTheta\_i}{v} - \left(\frac{1}{v} - 0.6931\right)} \end{array} \]
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
 :precision binary32
 (*
  (/ 0.5 v)
  (exp
   (-
    (/ (- (* cosTheta_O cosTheta_i) (* sinTheta_O sinTheta_i)) v)
    (- (/ 1.0 v) 0.6931)))))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
	return (0.5f / v) * expf(((((cosTheta_O * cosTheta_i) - (sinTheta_O * sinTheta_i)) / v) - ((1.0f / v) - 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 = (0.5e0 / v) * exp(((((costheta_o * costheta_i) - (sintheta_o * sintheta_i)) / v) - ((1.0e0 / v) - 0.6931e0)))
end function
function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
	return Float32(Float32(Float32(0.5) / v) * exp(Float32(Float32(Float32(Float32(cosTheta_O * cosTheta_i) - Float32(sinTheta_O * sinTheta_i)) / v) - Float32(Float32(Float32(1.0) / v) - Float32(0.6931)))))
end
function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
	tmp = (single(0.5) / v) * exp(((((cosTheta_O * cosTheta_i) - (sinTheta_O * sinTheta_i)) / v) - ((single(1.0) / v) - single(0.6931))));
end
\begin{array}{l}

\\
\frac{0.5}{v} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i - sinTheta\_O \cdot sinTheta\_i}{v} - \left(\frac{1}{v} - 0.6931\right)}
\end{array}
Derivation
  1. Initial program 99.6%

    \[e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)} \]
  2. Add Preprocessing
  3. Applied rewrites99.6%

    \[\leadsto \color{blue}{\frac{0.5}{v} \cdot e^{\frac{cosTheta\_O \cdot cosTheta\_i - \mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v} + 0.6931}} \]
  4. Step-by-step derivation
    1. lift-+.f32N/A

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{\frac{1}{2}}{v} \cdot e^{\color{blue}{\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \left(\frac{1}{v} - \frac{6931}{10000}\right)}} \]
  5. Applied rewrites99.6%

    \[\leadsto \frac{0.5}{v} \cdot e^{\color{blue}{\frac{cosTheta\_O \cdot cosTheta\_i - sinTheta\_O \cdot sinTheta\_i}{v} - \left(\frac{1}{v} - 0.6931\right)}} \]
  6. Add Preprocessing

Alternative 4: 99.7% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \frac{e^{0.6931 - \left(\frac{sinTheta\_O \cdot sinTheta\_i}{v} + \frac{1}{v}\right)}}{v} \cdot 0.5 \end{array} \]
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
 :precision binary32
 (* (/ (exp (- 0.6931 (+ (/ (* sinTheta_O sinTheta_i) v) (/ 1.0 v)))) v) 0.5))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
	return (expf((0.6931f - (((sinTheta_O * sinTheta_i) / v) + (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((0.6931e0 - (((sintheta_o * sintheta_i) / v) + (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(0.6931) - Float32(Float32(Float32(sinTheta_O * sinTheta_i) / v) + 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(0.6931) - (((sinTheta_O * sinTheta_i) / v) + (single(1.0) / v)))) / v) * single(0.5);
end
\begin{array}{l}

\\
\frac{e^{0.6931 - \left(\frac{sinTheta\_O \cdot sinTheta\_i}{v} + \frac{1}{v}\right)}}{v} \cdot 0.5
\end{array}
Derivation
  1. Initial program 99.6%

    \[e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)} \]
  2. Add Preprocessing
  3. Applied rewrites99.6%

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

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

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

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

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

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

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

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

      \[\leadsto \frac{e^{\frac{6931}{10000} - \frac{sinTheta\_O \cdot sinTheta\_i + 1}{v}}}{v} \cdot \frac{1}{2} \]
    8. lift-fma.f32N/A

      \[\leadsto \frac{e^{\frac{6931}{10000} - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}}}{v} \cdot \frac{1}{2} \]
    9. lift-/.f3299.7

      \[\leadsto \frac{e^{0.6931 - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}}}{v} \cdot 0.5 \]
  6. Applied rewrites99.7%

    \[\leadsto \color{blue}{\frac{e^{0.6931 - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}}}{v} \cdot 0.5} \]
  7. Step-by-step derivation
    1. lift-/.f32N/A

      \[\leadsto \frac{e^{\frac{6931}{10000} - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}}}{v} \cdot \frac{1}{2} \]
    2. lift-fma.f32N/A

      \[\leadsto \frac{e^{\frac{6931}{10000} - \frac{sinTheta\_O \cdot sinTheta\_i + 1}{v}}}{v} \cdot \frac{1}{2} \]
    3. div-addN/A

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

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

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

      \[\leadsto \frac{e^{\frac{6931}{10000} - \left(\frac{sinTheta\_O \cdot sinTheta\_i}{v} + \frac{1}{v}\right)}}{v} \cdot \frac{1}{2} \]
    7. lift-/.f3299.7

      \[\leadsto \frac{e^{0.6931 - \left(\frac{sinTheta\_O \cdot sinTheta\_i}{v} + \frac{1}{v}\right)}}{v} \cdot 0.5 \]
  8. Applied rewrites99.7%

    \[\leadsto \frac{e^{0.6931 - \left(\frac{sinTheta\_O \cdot sinTheta\_i}{v} + \frac{1}{v}\right)}}{v} \cdot 0.5 \]
  9. Add Preprocessing

Alternative 5: 99.6% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \frac{0.5}{v} \cdot e^{0.6931 - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}} \end{array} \]
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
 :precision binary32
 (* (/ 0.5 v) (exp (- 0.6931 (/ (fma sinTheta_O sinTheta_i 1.0) v)))))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
	return (0.5f / v) * expf((0.6931f - (fmaf(sinTheta_O, sinTheta_i, 1.0f) / v)));
}
function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
	return Float32(Float32(Float32(0.5) / v) * exp(Float32(Float32(0.6931) - Float32(fma(sinTheta_O, sinTheta_i, Float32(1.0)) / v))))
end
\begin{array}{l}

\\
\frac{0.5}{v} \cdot e^{0.6931 - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_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. Add Preprocessing
  3. Applied rewrites99.6%

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

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

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

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

      \[\leadsto \frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000} - \frac{sinTheta\_O \cdot sinTheta\_i + 1}{\color{blue}{v}}} \]
    4. lift-fma.f32N/A

      \[\leadsto \frac{\frac{1}{2}}{v} \cdot e^{\frac{6931}{10000} - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}} \]
    5. lift-/.f3299.6

      \[\leadsto \frac{0.5}{v} \cdot e^{0.6931 - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{\color{blue}{v}}} \]
  6. Applied rewrites99.6%

    \[\leadsto \frac{0.5}{v} \cdot e^{\color{blue}{0.6931 - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}}} \]
  7. Add Preprocessing

Alternative 6: 99.7% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \frac{e^{0.6931 - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}}}{v} \cdot 0.5 \end{array} \]
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
 :precision binary32
 (* (/ (exp (- 0.6931 (/ (fma sinTheta_O sinTheta_i 1.0) v))) v) 0.5))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
	return (expf((0.6931f - (fmaf(sinTheta_O, sinTheta_i, 1.0f) / v))) / v) * 0.5f;
}
function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
	return Float32(Float32(exp(Float32(Float32(0.6931) - Float32(fma(sinTheta_O, sinTheta_i, Float32(1.0)) / v))) / v) * Float32(0.5))
end
\begin{array}{l}

\\
\frac{e^{0.6931 - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}}}{v} \cdot 0.5
\end{array}
Derivation
  1. Initial program 99.6%

    \[e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)} \]
  2. Add Preprocessing
  3. Applied rewrites99.6%

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

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

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

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

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

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

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

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

      \[\leadsto \frac{e^{\frac{6931}{10000} - \frac{sinTheta\_O \cdot sinTheta\_i + 1}{v}}}{v} \cdot \frac{1}{2} \]
    8. lift-fma.f32N/A

      \[\leadsto \frac{e^{\frac{6931}{10000} - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}}}{v} \cdot \frac{1}{2} \]
    9. lift-/.f3299.7

      \[\leadsto \frac{e^{0.6931 - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}}}{v} \cdot 0.5 \]
  6. Applied rewrites99.7%

    \[\leadsto \color{blue}{\frac{e^{0.6931 - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}}}{v} \cdot 0.5} \]
  7. Add Preprocessing

Alternative 7: 99.7% accurate, 2.1× speedup?

\[\begin{array}{l} \\ \frac{e^{0.6931 - \frac{1}{v}}}{v} \cdot 0.5 \end{array} \]
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
 :precision binary32
 (* (/ (exp (- 0.6931 (/ 1.0 v))) v) 0.5))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
	return (expf((0.6931f - (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((0.6931e0 - (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(0.6931) - 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(0.6931) - (single(1.0) / v))) / v) * single(0.5);
end
\begin{array}{l}

\\
\frac{e^{0.6931 - \frac{1}{v}}}{v} \cdot 0.5
\end{array}
Derivation
  1. Initial program 99.6%

    \[e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)} \]
  2. Add Preprocessing
  3. Applied rewrites99.6%

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

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

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

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

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

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

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

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

      \[\leadsto \frac{e^{\frac{6931}{10000} - \frac{sinTheta\_O \cdot sinTheta\_i + 1}{v}}}{v} \cdot \frac{1}{2} \]
    8. lift-fma.f32N/A

      \[\leadsto \frac{e^{\frac{6931}{10000} - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}}}{v} \cdot \frac{1}{2} \]
    9. lift-/.f3299.7

      \[\leadsto \frac{e^{0.6931 - \frac{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}}}{v} \cdot 0.5 \]
  6. Applied rewrites99.7%

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

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

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

    Alternative 8: 18.6% accurate, 2.1× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;sinTheta\_i \cdot sinTheta\_O \leq 1.0000000359391298 \cdot 10^{-36}:\\ \;\;\;\;e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v}}\\ \mathbf{else}:\\ \;\;\;\;e^{-sinTheta\_O \cdot \frac{sinTheta\_i}{v}}\\ \end{array} \end{array} \]
    (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
     :precision binary32
     (if (<= (* sinTheta_i sinTheta_O) 1.0000000359391298e-36)
       (exp (/ (* cosTheta_O cosTheta_i) v))
       (exp (- (* sinTheta_O (/ sinTheta_i v))))))
    float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
    	float tmp;
    	if ((sinTheta_i * sinTheta_O) <= 1.0000000359391298e-36f) {
    		tmp = expf(((cosTheta_O * cosTheta_i) / v));
    	} else {
    		tmp = expf(-(sinTheta_O * (sinTheta_i / v)));
    	}
    	return tmp;
    }
    
    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) :: tmp
        if ((sintheta_i * sintheta_o) <= 1.0000000359391298e-36) then
            tmp = exp(((costheta_o * costheta_i) / v))
        else
            tmp = exp(-(sintheta_o * (sintheta_i / v)))
        end if
        code = tmp
    end function
    
    function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
    	tmp = Float32(0.0)
    	if (Float32(sinTheta_i * sinTheta_O) <= Float32(1.0000000359391298e-36))
    		tmp = exp(Float32(Float32(cosTheta_O * cosTheta_i) / v));
    	else
    		tmp = exp(Float32(-Float32(sinTheta_O * Float32(sinTheta_i / v))));
    	end
    	return tmp
    end
    
    function tmp_2 = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
    	tmp = single(0.0);
    	if ((sinTheta_i * sinTheta_O) <= single(1.0000000359391298e-36))
    		tmp = exp(((cosTheta_O * cosTheta_i) / v));
    	else
    		tmp = exp(-(sinTheta_O * (sinTheta_i / v)));
    	end
    	tmp_2 = tmp;
    end
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;sinTheta\_i \cdot sinTheta\_O \leq 1.0000000359391298 \cdot 10^{-36}:\\
    \;\;\;\;e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v}}\\
    
    \mathbf{else}:\\
    \;\;\;\;e^{-sinTheta\_O \cdot \frac{sinTheta\_i}{v}}\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (*.f32 sinTheta_i sinTheta_O) < 1.00000004e-36

      1. Initial program 99.7%

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

        \[\leadsto e^{\color{blue}{\frac{cosTheta\_O \cdot cosTheta\_i}{v}}} \]
      4. Step-by-step derivation
        1. lower-/.f32N/A

          \[\leadsto e^{\frac{cosTheta\_O \cdot cosTheta\_i}{\color{blue}{v}}} \]
        2. lower-*.f3213.2

          \[\leadsto e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v}} \]
      5. Applied rewrites13.2%

        \[\leadsto e^{\color{blue}{\frac{cosTheta\_O \cdot cosTheta\_i}{v}}} \]

      if 1.00000004e-36 < (*.f32 sinTheta_i sinTheta_O)

      1. Initial program 99.6%

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

        \[\leadsto e^{\color{blue}{-1 \cdot \frac{sinTheta\_O \cdot sinTheta\_i}{v}}} \]
      4. Step-by-step derivation
        1. mul-1-negN/A

          \[\leadsto e^{\mathsf{neg}\left(\frac{sinTheta\_O \cdot sinTheta\_i}{v}\right)} \]
        2. lower-neg.f32N/A

          \[\leadsto e^{-\frac{sinTheta\_O \cdot sinTheta\_i}{v}} \]
        3. lower-/.f32N/A

          \[\leadsto e^{-\frac{sinTheta\_O \cdot sinTheta\_i}{v}} \]
        4. lower-*.f3237.9

          \[\leadsto e^{-\frac{sinTheta\_O \cdot sinTheta\_i}{v}} \]
      5. Applied rewrites37.9%

        \[\leadsto e^{\color{blue}{-\frac{sinTheta\_O \cdot sinTheta\_i}{v}}} \]
      6. Step-by-step derivation
        1. lift-*.f32N/A

          \[\leadsto e^{-\frac{sinTheta\_O \cdot sinTheta\_i}{v}} \]
        2. lift-/.f32N/A

          \[\leadsto e^{-\frac{sinTheta\_O \cdot sinTheta\_i}{v}} \]
        3. associate-/l*N/A

          \[\leadsto e^{-sinTheta\_O \cdot \frac{sinTheta\_i}{v}} \]
        4. lower-*.f32N/A

          \[\leadsto e^{-sinTheta\_O \cdot \frac{sinTheta\_i}{v}} \]
        5. lower-/.f3237.9

          \[\leadsto e^{-sinTheta\_O \cdot \frac{sinTheta\_i}{v}} \]
      7. Applied rewrites37.9%

        \[\leadsto e^{-sinTheta\_O \cdot \frac{sinTheta\_i}{v}} \]
    3. Recombined 2 regimes into one program.
    4. Add Preprocessing

    Alternative 9: 97.7% accurate, 2.2× speedup?

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

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

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

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

        \[\leadsto e^{\frac{cosTheta\_O \cdot cosTheta\_i - \left(1 + sinTheta\_O \cdot sinTheta\_i\right)}{v}} \]
      4. +-commutativeN/A

        \[\leadsto e^{\frac{cosTheta\_O \cdot cosTheta\_i - \left(sinTheta\_O \cdot sinTheta\_i + 1\right)}{v}} \]
      5. lower-fma.f3297.7

        \[\leadsto e^{\frac{cosTheta\_O \cdot cosTheta\_i - \mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}{v}} \]
    5. Applied rewrites97.7%

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

    Alternative 10: 13.2% accurate, 2.3× speedup?

    \[\begin{array}{l} \\ e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v}} \end{array} \]
    (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
     :precision binary32
     (exp (/ (* cosTheta_O cosTheta_i) v)))
    float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
    	return expf(((cosTheta_O * cosTheta_i) / 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_o * costheta_i) / v))
    end function
    
    function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
    	return exp(Float32(Float32(cosTheta_O * cosTheta_i) / v))
    end
    
    function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
    	tmp = exp(((cosTheta_O * cosTheta_i) / v));
    end
    
    \begin{array}{l}
    
    \\
    e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v}}
    \end{array}
    
    Derivation
    1. Initial program 99.6%

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

      \[\leadsto e^{\color{blue}{\frac{cosTheta\_O \cdot cosTheta\_i}{v}}} \]
    4. Step-by-step derivation
      1. lower-/.f32N/A

        \[\leadsto e^{\frac{cosTheta\_O \cdot cosTheta\_i}{\color{blue}{v}}} \]
      2. lower-*.f3213.2

        \[\leadsto e^{\frac{cosTheta\_O \cdot cosTheta\_i}{v}} \]
    5. Applied rewrites13.2%

      \[\leadsto e^{\color{blue}{\frac{cosTheta\_O \cdot cosTheta\_i}{v}}} \]
    6. Add Preprocessing

    Alternative 11: 4.6% accurate, 2.3× speedup?

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

      \[e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)} \]
    2. Add Preprocessing
    3. Applied rewrites99.6%

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

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{e^{\frac{6931}{10000}}}{v}} \]
    5. Step-by-step derivation
      1. *-commutativeN/A

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

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

        \[\leadsto \frac{e^{\frac{6931}{10000}}}{v} \cdot \frac{1}{2} \]
      4. lift-exp.f324.6

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

      \[\leadsto \color{blue}{\frac{e^{0.6931}}{v} \cdot 0.5} \]
    7. Add Preprocessing

    Alternative 12: 4.6% accurate, 2.3× speedup?

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

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

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

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

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

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

        \[\leadsto e^{\frac{6931}{10000}} \cdot e^{\log \frac{1}{2} - 1 \cdot \log v} \]
      6. log-pow-revN/A

        \[\leadsto e^{\frac{6931}{10000}} \cdot e^{\log \frac{1}{2} - \log \left({v}^{1}\right)} \]
      7. unpow1N/A

        \[\leadsto e^{\frac{6931}{10000}} \cdot e^{\log \frac{1}{2} - \log v} \]
      8. log-divN/A

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

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

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

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

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

        \[\leadsto e^{\frac{6931}{10000}} \cdot \frac{\color{blue}{1}}{2 \cdot v} \]
      14. associate-/r*N/A

        \[\leadsto e^{\frac{6931}{10000}} \cdot \frac{\frac{1}{2}}{\color{blue}{v}} \]
      15. metadata-evalN/A

        \[\leadsto e^{\frac{6931}{10000}} \cdot \frac{\frac{1}{2}}{v} \]
      16. lower-/.f324.6

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

      \[\leadsto \color{blue}{e^{0.6931} \cdot \frac{0.5}{v}} \]
    6. Add Preprocessing

    Reproduce

    ?
    herbie shell --seed 2025087 
    (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))))))