HairBSDF, Mp, lower

Percentage Accurate: 99.6% → 99.8%
Time: 11.1s
Alternatives: 8
Speedup: 1.9×

Specification

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

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

Sampling outcomes in binary32 precision:

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 8 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)))));
}
real(4) function code(costheta_i, costheta_o, sintheta_i, sintheta_o, v)
    real(4), intent (in) :: costheta_i
    real(4), intent (in) :: costheta_o
    real(4), intent (in) :: sintheta_i
    real(4), intent (in) :: sintheta_o
    real(4), intent (in) :: v
    code = exp(((((((costheta_i * costheta_o) / v) - ((sintheta_i * sintheta_o) / v)) - (1.0e0 / v)) + 0.6931e0) + log((1.0e0 / (2.0e0 * v)))))
end function
function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
	return exp(Float32(Float32(Float32(Float32(Float32(Float32(cosTheta_i * cosTheta_O) / v) - Float32(Float32(sinTheta_i * sinTheta_O) / v)) - Float32(Float32(1.0) / v)) + Float32(0.6931)) + log(Float32(Float32(1.0) / Float32(Float32(2.0) * v)))))
end
function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
	tmp = exp(((((((cosTheta_i * cosTheta_O) / v) - ((sinTheta_i * sinTheta_O) / v)) - (single(1.0) / v)) + single(0.6931)) + log((single(1.0) / (single(2.0) * v)))));
end
\begin{array}{l}

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

Alternative 1: 99.8% accurate, 1.1× speedup?

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

\\
e^{\left(\frac{\left(cosTheta\_O \cdot cosTheta\_i - sinTheta\_O \cdot sinTheta\_i\right) \cdot v + v \cdot -1}{v \cdot v} + 0.6931\right) - \log \left(2 \cdot v\right)}
\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--.f32N/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto e^{\left(\frac{\left(cosTheta\_O \cdot cosTheta\_i - sinTheta\_O \cdot sinTheta\_i\right) \cdot \left(-v\right) - v \cdot -1}{v \cdot \left(-v\right)} + \frac{6931}{10000}\right) + \left(\mathsf{neg}\left(\color{blue}{\log \left(2 \cdot v\right)}\right)\right)} \]
    5. lower-neg.f3299.7

      \[\leadsto e^{\left(\frac{\left(cosTheta\_O \cdot cosTheta\_i - sinTheta\_O \cdot sinTheta\_i\right) \cdot \left(-v\right) - v \cdot -1}{v \cdot \left(-v\right)} + 0.6931\right) + \color{blue}{\left(-\log \left(2 \cdot v\right)\right)}} \]
  6. Applied rewrites99.7%

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

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

Alternative 2: 99.8% accurate, 1.2× speedup?

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

\\
e^{\left(0.6931 + \frac{-1}{v}\right) - \log \left(2 \cdot v\right)}
\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-+.f32N/A

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

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

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

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

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

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

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

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

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

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

      \[\leadsto e^{\left(\frac{6931}{10000} + \frac{cosTheta\_i \cdot cosTheta\_O + \color{blue}{-1}}{v}\right) - \log \left(2 \cdot v\right)} \]
    4. lower-fma.f3298.5

      \[\leadsto e^{\left(0.6931 + \frac{\color{blue}{\mathsf{fma}\left(cosTheta\_i, cosTheta\_O, -1\right)}}{v}\right) - \log \left(2 \cdot v\right)} \]
  7. Applied rewrites98.2%

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

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

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

    Alternative 3: 99.8% accurate, 1.9× speedup?

    \[\begin{array}{l} \\ \frac{e^{0.6931 + \frac{\left(cosTheta\_O \cdot cosTheta\_i - sinTheta\_O \cdot sinTheta\_i\right) - 1}{v}}}{2 \cdot v} \end{array} \]
    (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
     :precision binary32
     (/
      (exp
       (+
        0.6931
        (/ (- (- (* cosTheta_O cosTheta_i) (* sinTheta_O sinTheta_i)) 1.0) v)))
      (* 2.0 v)))
    float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
    	return expf((0.6931f + ((((cosTheta_O * cosTheta_i) - (sinTheta_O * sinTheta_i)) - 1.0f) / v))) / (2.0f * v);
    }
    
    real(4) function code(costheta_i, costheta_o, sintheta_i, sintheta_o, v)
        real(4), intent (in) :: costheta_i
        real(4), intent (in) :: costheta_o
        real(4), intent (in) :: sintheta_i
        real(4), intent (in) :: sintheta_o
        real(4), intent (in) :: v
        code = exp((0.6931e0 + ((((costheta_o * costheta_i) - (sintheta_o * sintheta_i)) - 1.0e0) / v))) / (2.0e0 * v)
    end function
    
    function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
    	return Float32(exp(Float32(Float32(0.6931) + Float32(Float32(Float32(Float32(cosTheta_O * cosTheta_i) - Float32(sinTheta_O * sinTheta_i)) - Float32(1.0)) / v))) / Float32(Float32(2.0) * v))
    end
    
    function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
    	tmp = exp((single(0.6931) + ((((cosTheta_O * cosTheta_i) - (sinTheta_O * sinTheta_i)) - single(1.0)) / v))) / (single(2.0) * v);
    end
    
    \begin{array}{l}
    
    \\
    \frac{e^{0.6931 + \frac{\left(cosTheta\_O \cdot cosTheta\_i - sinTheta\_O \cdot sinTheta\_i\right) - 1}{v}}}{2 \cdot 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. Step-by-step derivation
      1. lift-exp.f32N/A

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

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

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

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

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

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

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

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

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

    Alternative 4: 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);
    }
    
    real(4) function code(costheta_i, costheta_o, sintheta_i, sintheta_o, v)
        real(4), intent (in) :: costheta_i
        real(4), intent (in) :: costheta_o
        real(4), intent (in) :: sintheta_i
        real(4), intent (in) :: sintheta_o
        real(4), intent (in) :: v
        code = exp((((-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. Step-by-step derivation
      1. lift-+.f32N/A

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

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

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

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

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

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

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

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

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

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

        \[\leadsto e^{\left(\frac{6931}{10000} + \frac{cosTheta\_i \cdot cosTheta\_O + \color{blue}{-1}}{v}\right) - \log \left(2 \cdot v\right)} \]
      4. lower-fma.f3298.2

        \[\leadsto e^{\left(0.6931 + \frac{\color{blue}{\mathsf{fma}\left(cosTheta\_i, cosTheta\_O, -1\right)}}{v}\right) - \log \left(2 \cdot v\right)} \]
    7. Applied rewrites97.8%

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

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

        \[\leadsto e^{\left(0.6931 + \frac{-1}{v}\right) - \log \left(2 \cdot v\right)} \]
      2. Step-by-step derivation
        1. lift-exp.f32N/A

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

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

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

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

          \[\leadsto \frac{e^{\frac{6931}{10000} + \frac{-1}{v}}}{\color{blue}{2 \cdot v}} \]
        6. div-invN/A

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

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

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

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

          \[\leadsto \color{blue}{e^{\frac{6931}{10000} + \frac{-1}{v}} \cdot \frac{\frac{1}{2}}{v}} \]
      3. Applied rewrites99.2%

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

      Alternative 5: 98.2% accurate, 2.3× speedup?

      \[\begin{array}{l} \\ e^{\frac{-1 - sinTheta\_i \cdot sinTheta\_O}{v}} \end{array} \]
      (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
       :precision binary32
       (exp (/ (- -1.0 (* sinTheta_i sinTheta_O)) v)))
      float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
      	return expf(((-1.0f - (sinTheta_i * sinTheta_O)) / v));
      }
      
      real(4) function code(costheta_i, costheta_o, sintheta_i, sintheta_o, v)
          real(4), intent (in) :: costheta_i
          real(4), intent (in) :: costheta_o
          real(4), intent (in) :: sintheta_i
          real(4), intent (in) :: sintheta_o
          real(4), intent (in) :: v
          code = exp((((-1.0e0) - (sintheta_i * sintheta_o)) / v))
      end function
      
      function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
      	return exp(Float32(Float32(Float32(-1.0) - Float32(sinTheta_i * sinTheta_O)) / v))
      end
      
      function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
      	tmp = exp(((single(-1.0) - (sinTheta_i * sinTheta_O)) / v));
      end
      
      \begin{array}{l}
      
      \\
      e^{\frac{-1 - sinTheta\_i \cdot sinTheta\_O}{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. Step-by-step derivation
        1. lift-+.f32N/A

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

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

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

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

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

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

        \[\leadsto \color{blue}{e^{\left(0.6931 + \frac{\left(cosTheta\_O \cdot cosTheta\_i - sinTheta\_O \cdot sinTheta\_i\right) - 1}{v}\right) - \log \left(2 \cdot v\right)}} \]
      5. Taylor expanded in v around 0

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

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

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

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

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

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

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

          \[\leadsto e^{\frac{\color{blue}{\mathsf{fma}\left(cosTheta\_i, cosTheta\_O, -1\right)} - sinTheta\_O \cdot sinTheta\_i}{v}} \]
        8. *-commutativeN/A

          \[\leadsto e^{\frac{\mathsf{fma}\left(cosTheta\_i, cosTheta\_O, -1\right) - \color{blue}{sinTheta\_i \cdot sinTheta\_O}}{v}} \]
        9. lower-*.f3296.1

          \[\leadsto e^{\frac{\mathsf{fma}\left(cosTheta\_i, cosTheta\_O, -1\right) - \color{blue}{sinTheta\_i \cdot sinTheta\_O}}{v}} \]
      7. Applied rewrites96.1%

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

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

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

        Alternative 6: 98.0% accurate, 2.3× speedup?

        \[\begin{array}{l} \\ e^{\frac{\mathsf{fma}\left(cosTheta\_i, cosTheta\_O, -1\right)}{v}} \end{array} \]
        (FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
         :precision binary32
         (exp (/ (fma cosTheta_i cosTheta_O -1.0) v)))
        float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
        	return expf((fmaf(cosTheta_i, cosTheta_O, -1.0f) / v));
        }
        
        function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
        	return exp(Float32(fma(cosTheta_i, cosTheta_O, Float32(-1.0)) / v))
        end
        
        \begin{array}{l}
        
        \\
        e^{\frac{\mathsf{fma}\left(cosTheta\_i, cosTheta\_O, -1\right)}{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. Step-by-step derivation
          1. lift-+.f32N/A

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

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

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

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

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

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

          \[\leadsto \color{blue}{e^{\left(0.6931 + \frac{\left(cosTheta\_O \cdot cosTheta\_i - sinTheta\_O \cdot sinTheta\_i\right) - 1}{v}\right) - \log \left(2 \cdot v\right)}} \]
        5. Taylor expanded in v around 0

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

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

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

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

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

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

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

            \[\leadsto e^{\frac{\color{blue}{\mathsf{fma}\left(cosTheta\_i, cosTheta\_O, -1\right)} - sinTheta\_O \cdot sinTheta\_i}{v}} \]
          8. *-commutativeN/A

            \[\leadsto e^{\frac{\mathsf{fma}\left(cosTheta\_i, cosTheta\_O, -1\right) - \color{blue}{sinTheta\_i \cdot sinTheta\_O}}{v}} \]
          9. lower-*.f3296.5

            \[\leadsto e^{\frac{\mathsf{fma}\left(cosTheta\_i, cosTheta\_O, -1\right) - \color{blue}{sinTheta\_i \cdot sinTheta\_O}}{v}} \]
        7. Applied rewrites96.5%

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

          \[\leadsto e^{\frac{cosTheta\_O \cdot cosTheta\_i - 1}{\color{blue}{v}}} \]
        9. Step-by-step derivation
          1. Applied rewrites96.1%

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

          Alternative 7: 13.1% accurate, 2.3× speedup?

          \[\begin{array}{l} \\ e^{cosTheta\_O \cdot \frac{cosTheta\_i}{v}} \end{array} \]
          (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)));
          }
          
          real(4) function code(costheta_i, costheta_o, sintheta_i, sintheta_o, v)
              real(4), intent (in) :: costheta_i
              real(4), intent (in) :: costheta_o
              real(4), intent (in) :: sintheta_i
              real(4), intent (in) :: sintheta_o
              real(4), intent (in) :: v
              code = exp((costheta_o * (costheta_i / v)))
          end function
          
          function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v)
          	return exp(Float32(cosTheta_O * Float32(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^{cosTheta\_O \cdot \frac{cosTheta\_i}{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. Step-by-step derivation
            1. lift-+.f32N/A

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

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

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

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

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

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

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

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

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

              \[\leadsto e^{\frac{\color{blue}{cosTheta\_i \cdot cosTheta\_O}}{v}} \]
            3. lower-*.f3213.6

              \[\leadsto e^{\frac{\color{blue}{cosTheta\_i \cdot cosTheta\_O}}{v}} \]
          7. Applied rewrites13.6%

            \[\leadsto e^{\color{blue}{\frac{cosTheta\_i \cdot cosTheta\_O}{v}}} \]
          8. Step-by-step derivation
            1. Applied rewrites13.6%

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

            Alternative 8: 4.6% accurate, 2.3× speedup?

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

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

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

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

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

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

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

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

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

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

                \[\leadsto \left(\color{blue}{e^{\frac{6931}{10000}}} \cdot \frac{-1}{2}\right) \cdot \left(\mathsf{neg}\left(\frac{1}{v}\right)\right) \]
              11. distribute-neg-fracN/A

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

                \[\leadsto \left(e^{\frac{6931}{10000}} \cdot \frac{-1}{2}\right) \cdot \frac{\color{blue}{-1}}{v} \]
              13. lower-/.f324.7

                \[\leadsto \left(e^{0.6931} \cdot -0.5\right) \cdot \color{blue}{\frac{-1}{v}} \]
            5. Applied rewrites4.7%

              \[\leadsto \color{blue}{\left(e^{0.6931} \cdot -0.5\right) \cdot \frac{-1}{v}} \]
            6. Step-by-step derivation
              1. Applied rewrites4.7%

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

              Reproduce

              ?
              herbie shell --seed 2024303 
              (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))))))