Beckmann Sample, near normal, slope_x

Percentage Accurate: 57.5% → 97.7%
Time: 10.0s
Alternatives: 10
Speedup: 11.6×

Specification

?
\[\left(\left(cosTheta\_i > 0.9999 \land cosTheta\_i \leq 1\right) \land \left(2.328306437 \cdot 10^{-10} \leq u1 \land u1 \leq 1\right)\right) \land \left(2.328306437 \cdot 10^{-10} \leq u2 \land u2 \leq 1\right)\]
\[\begin{array}{l} \\ \sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \end{array} \]
(FPCore (cosTheta_i u1 u2)
 :precision binary32
 (* (sqrt (- (log (- 1.0 u1)))) (cos (* (* 2.0 (PI)) u2))))
\begin{array}{l}

\\
\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\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 10 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: 57.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \end{array} \]
(FPCore (cosTheta_i u1 u2)
 :precision binary32
 (* (sqrt (- (log (- 1.0 u1)))) (cos (* (* 2.0 (PI)) u2))))
\begin{array}{l}

\\
\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)
\end{array}

Alternative 1: 97.7% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sqrt[3]{\mathsf{PI}\left(\right)}\\ \mathbf{if}\;1 - u1 \leq 0.9943000078201294:\\ \;\;\;\;\cos \left(\left({t\_0}^{2} \cdot \left(2 \cdot u2\right)\right) \cdot t\_0\right) \cdot \sqrt{-\log \left(1 - u1\right)}\\ \mathbf{else}:\\ \;\;\;\;\cos \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right) \cdot \sqrt{-\frac{1 \cdot u1}{-1 - -0.5 \cdot u1}}\\ \end{array} \end{array} \]
(FPCore (cosTheta_i u1 u2)
 :precision binary32
 (let* ((t_0 (cbrt (PI))))
   (if (<= (- 1.0 u1) 0.9943000078201294)
     (* (cos (* (* (pow t_0 2.0) (* 2.0 u2)) t_0)) (sqrt (- (log (- 1.0 u1)))))
     (*
      (cos (* (* (PI) 2.0) u2))
      (sqrt (- (/ (* 1.0 u1) (- -1.0 (* -0.5 u1)))))))))
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sqrt[3]{\mathsf{PI}\left(\right)}\\
\mathbf{if}\;1 - u1 \leq 0.9943000078201294:\\
\;\;\;\;\cos \left(\left({t\_0}^{2} \cdot \left(2 \cdot u2\right)\right) \cdot t\_0\right) \cdot \sqrt{-\log \left(1 - u1\right)}\\

\mathbf{else}:\\
\;\;\;\;\cos \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right) \cdot \sqrt{-\frac{1 \cdot u1}{-1 - -0.5 \cdot u1}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f32 #s(literal 1 binary32) u1) < 0.994300008

    1. Initial program 96.3%

      \[\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-*.f32N/A

        \[\leadsto \sqrt{-\log \left(1 - u1\right)} \cdot \cos \color{blue}{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)} \]
      2. *-commutativeN/A

        \[\leadsto \sqrt{-\log \left(1 - u1\right)} \cdot \cos \color{blue}{\left(u2 \cdot \left(2 \cdot \mathsf{PI}\left(\right)\right)\right)} \]
      3. lift-*.f32N/A

        \[\leadsto \sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(u2 \cdot \color{blue}{\left(2 \cdot \mathsf{PI}\left(\right)\right)}\right) \]
      4. associate-*r*N/A

        \[\leadsto \sqrt{-\log \left(1 - u1\right)} \cdot \cos \color{blue}{\left(\left(u2 \cdot 2\right) \cdot \mathsf{PI}\left(\right)\right)} \]
      5. lift-PI.f32N/A

        \[\leadsto \sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(u2 \cdot 2\right) \cdot \color{blue}{\mathsf{PI}\left(\right)}\right) \]
      6. add-cube-cbrtN/A

        \[\leadsto \sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(u2 \cdot 2\right) \cdot \color{blue}{\left(\left(\sqrt[3]{\mathsf{PI}\left(\right)} \cdot \sqrt[3]{\mathsf{PI}\left(\right)}\right) \cdot \sqrt[3]{\mathsf{PI}\left(\right)}\right)}\right) \]
      7. associate-*r*N/A

        \[\leadsto \sqrt{-\log \left(1 - u1\right)} \cdot \cos \color{blue}{\left(\left(\left(u2 \cdot 2\right) \cdot \left(\sqrt[3]{\mathsf{PI}\left(\right)} \cdot \sqrt[3]{\mathsf{PI}\left(\right)}\right)\right) \cdot \sqrt[3]{\mathsf{PI}\left(\right)}\right)} \]
      8. lower-*.f32N/A

        \[\leadsto \sqrt{-\log \left(1 - u1\right)} \cdot \cos \color{blue}{\left(\left(\left(u2 \cdot 2\right) \cdot \left(\sqrt[3]{\mathsf{PI}\left(\right)} \cdot \sqrt[3]{\mathsf{PI}\left(\right)}\right)\right) \cdot \sqrt[3]{\mathsf{PI}\left(\right)}\right)} \]
      9. lower-*.f32N/A

        \[\leadsto \sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\color{blue}{\left(\left(u2 \cdot 2\right) \cdot \left(\sqrt[3]{\mathsf{PI}\left(\right)} \cdot \sqrt[3]{\mathsf{PI}\left(\right)}\right)\right)} \cdot \sqrt[3]{\mathsf{PI}\left(\right)}\right) \]
      10. lower-*.f32N/A

        \[\leadsto \sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(\color{blue}{\left(u2 \cdot 2\right)} \cdot \left(\sqrt[3]{\mathsf{PI}\left(\right)} \cdot \sqrt[3]{\mathsf{PI}\left(\right)}\right)\right) \cdot \sqrt[3]{\mathsf{PI}\left(\right)}\right) \]
      11. pow2N/A

        \[\leadsto \sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(\left(u2 \cdot 2\right) \cdot \color{blue}{{\left(\sqrt[3]{\mathsf{PI}\left(\right)}\right)}^{2}}\right) \cdot \sqrt[3]{\mathsf{PI}\left(\right)}\right) \]
      12. lower-pow.f32N/A

        \[\leadsto \sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(\left(u2 \cdot 2\right) \cdot \color{blue}{{\left(\sqrt[3]{\mathsf{PI}\left(\right)}\right)}^{2}}\right) \cdot \sqrt[3]{\mathsf{PI}\left(\right)}\right) \]
      13. lift-PI.f32N/A

        \[\leadsto \sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(\left(u2 \cdot 2\right) \cdot {\left(\sqrt[3]{\color{blue}{\mathsf{PI}\left(\right)}}\right)}^{2}\right) \cdot \sqrt[3]{\mathsf{PI}\left(\right)}\right) \]
      14. lower-cbrt.f32N/A

        \[\leadsto \sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(\left(u2 \cdot 2\right) \cdot {\color{blue}{\left(\sqrt[3]{\mathsf{PI}\left(\right)}\right)}}^{2}\right) \cdot \sqrt[3]{\mathsf{PI}\left(\right)}\right) \]
      15. lift-PI.f32N/A

        \[\leadsto \sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(\left(u2 \cdot 2\right) \cdot {\left(\sqrt[3]{\mathsf{PI}\left(\right)}\right)}^{2}\right) \cdot \sqrt[3]{\color{blue}{\mathsf{PI}\left(\right)}}\right) \]
      16. lower-cbrt.f3296.3

        \[\leadsto \sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(\left(u2 \cdot 2\right) \cdot {\left(\sqrt[3]{\mathsf{PI}\left(\right)}\right)}^{2}\right) \cdot \color{blue}{\sqrt[3]{\mathsf{PI}\left(\right)}}\right) \]
    4. Applied rewrites96.3%

      \[\leadsto \sqrt{-\log \left(1 - u1\right)} \cdot \cos \color{blue}{\left(\left(\left(u2 \cdot 2\right) \cdot {\left(\sqrt[3]{\mathsf{PI}\left(\right)}\right)}^{2}\right) \cdot \sqrt[3]{\mathsf{PI}\left(\right)}\right)} \]

    if 0.994300008 < (-.f32 #s(literal 1 binary32) u1)

    1. Initial program 44.5%

      \[\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
    2. Add Preprocessing
    3. Taylor expanded in u1 around 0

      \[\leadsto \sqrt{-\color{blue}{u1 \cdot \left(\frac{-1}{2} \cdot u1 - 1\right)}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \sqrt{-\color{blue}{\left(\frac{-1}{2} \cdot u1 - 1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
      2. lower-*.f32N/A

        \[\leadsto \sqrt{-\color{blue}{\left(\frac{-1}{2} \cdot u1 - 1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
      3. sub-negN/A

        \[\leadsto \sqrt{-\color{blue}{\left(\frac{-1}{2} \cdot u1 + \left(\mathsf{neg}\left(1\right)\right)\right)} \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
      4. metadata-evalN/A

        \[\leadsto \sqrt{-\left(\frac{-1}{2} \cdot u1 + \color{blue}{-1}\right) \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
      5. lower-fma.f3269.2

        \[\leadsto \sqrt{-\color{blue}{\mathsf{fma}\left(-0.5, u1, -1\right)} \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
    5. Applied rewrites69.5%

      \[\leadsto \sqrt{-\color{blue}{\mathsf{fma}\left(-0.5, u1, -1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
    6. Step-by-step derivation
      1. Applied rewrites98.0%

        \[\leadsto \sqrt{-\frac{\left(1 - \left(u1 \cdot u1\right) \cdot 0.25\right) \cdot u1}{\color{blue}{-1 - -0.5 \cdot u1}}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
      2. Taylor expanded in u1 around 0

        \[\leadsto \sqrt{-\frac{1 \cdot u1}{-1 - \frac{-1}{2} \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
      3. Step-by-step derivation
        1. Applied rewrites98.5%

          \[\leadsto \sqrt{-\frac{1 \cdot u1}{-1 - -0.5 \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
      4. Recombined 2 regimes into one program.
      5. Final simplification98.0%

        \[\leadsto \begin{array}{l} \mathbf{if}\;1 - u1 \leq 0.9943000078201294:\\ \;\;\;\;\cos \left(\left({\left(\sqrt[3]{\mathsf{PI}\left(\right)}\right)}^{2} \cdot \left(2 \cdot u2\right)\right) \cdot \sqrt[3]{\mathsf{PI}\left(\right)}\right) \cdot \sqrt{-\log \left(1 - u1\right)}\\ \mathbf{else}:\\ \;\;\;\;\cos \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right) \cdot \sqrt{-\frac{1 \cdot u1}{-1 - -0.5 \cdot u1}}\\ \end{array} \]
      6. Add Preprocessing

      Alternative 2: 83.7% accurate, 1.0× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right)\\ \mathbf{if}\;t\_0 \leq 0.9999899864196777:\\ \;\;\;\;\sqrt{u1} \cdot t\_0\\ \mathbf{else}:\\ \;\;\;\;1 \cdot \sqrt{-\frac{\left(1 - \left(u1 \cdot u1\right) \cdot 0.25\right) \cdot u1}{-1 - -0.5 \cdot u1}}\\ \end{array} \end{array} \]
      (FPCore (cosTheta_i u1 u2)
       :precision binary32
       (let* ((t_0 (cos (* (* (PI) 2.0) u2))))
         (if (<= t_0 0.9999899864196777)
           (* (sqrt u1) t_0)
           (*
            1.0
            (sqrt (- (/ (* (- 1.0 (* (* u1 u1) 0.25)) u1) (- -1.0 (* -0.5 u1)))))))))
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      t_0 := \cos \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right)\\
      \mathbf{if}\;t\_0 \leq 0.9999899864196777:\\
      \;\;\;\;\sqrt{u1} \cdot t\_0\\
      
      \mathbf{else}:\\
      \;\;\;\;1 \cdot \sqrt{-\frac{\left(1 - \left(u1 \cdot u1\right) \cdot 0.25\right) \cdot u1}{-1 - -0.5 \cdot u1}}\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2)) < 0.999989986

        1. Initial program 58.1%

          \[\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
        2. Add Preprocessing
        3. Applied rewrites10.8%

          \[\leadsto \color{blue}{{\left({\left(\mathsf{log1p}\left(u1\right)\right)}^{0.25}\right)}^{2}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
        4. Taylor expanded in u1 around 0

          \[\leadsto \color{blue}{\sqrt{u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
        5. Step-by-step derivation
          1. lower-sqrt.f3277.5

            \[\leadsto \color{blue}{\sqrt{u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
        6. Applied rewrites77.5%

          \[\leadsto \color{blue}{\sqrt{u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]

        if 0.999989986 < (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2))

        1. Initial program 56.6%

          \[\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
        2. Add Preprocessing
        3. Taylor expanded in u1 around 0

          \[\leadsto \sqrt{-\color{blue}{u1 \cdot \left(\frac{-1}{2} \cdot u1 - 1\right)}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
        4. Step-by-step derivation
          1. *-commutativeN/A

            \[\leadsto \sqrt{-\color{blue}{\left(\frac{-1}{2} \cdot u1 - 1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
          2. lower-*.f32N/A

            \[\leadsto \sqrt{-\color{blue}{\left(\frac{-1}{2} \cdot u1 - 1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
          3. sub-negN/A

            \[\leadsto \sqrt{-\color{blue}{\left(\frac{-1}{2} \cdot u1 + \left(\mathsf{neg}\left(1\right)\right)\right)} \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
          4. metadata-evalN/A

            \[\leadsto \sqrt{-\left(\frac{-1}{2} \cdot u1 + \color{blue}{-1}\right) \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
          5. lower-fma.f3276.1

            \[\leadsto \sqrt{-\color{blue}{\mathsf{fma}\left(-0.5, u1, -1\right)} \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
        5. Applied rewrites75.8%

          \[\leadsto \sqrt{-\color{blue}{\mathsf{fma}\left(-0.5, u1, -1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
        6. Step-by-step derivation
          1. Applied rewrites87.2%

            \[\leadsto \sqrt{-\frac{\left(1 - \left(u1 \cdot u1\right) \cdot 0.25\right) \cdot u1}{\color{blue}{-1 - -0.5 \cdot u1}}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
          2. Taylor expanded in u2 around 0

            \[\leadsto \sqrt{-\frac{\left(1 - \left(u1 \cdot u1\right) \cdot \frac{1}{4}\right) \cdot u1}{-1 - \frac{-1}{2} \cdot u1}} \cdot \color{blue}{1} \]
          3. Step-by-step derivation
            1. Applied rewrites86.1%

              \[\leadsto \sqrt{-\frac{\left(1 - \left(u1 \cdot u1\right) \cdot 0.25\right) \cdot u1}{-1 - -0.5 \cdot u1}} \cdot \color{blue}{1} \]
          4. Recombined 2 regimes into one program.
          5. Final simplification83.5%

            \[\leadsto \begin{array}{l} \mathbf{if}\;\cos \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right) \leq 0.9999899864196777:\\ \;\;\;\;\sqrt{u1} \cdot \cos \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right)\\ \mathbf{else}:\\ \;\;\;\;1 \cdot \sqrt{-\frac{\left(1 - \left(u1 \cdot u1\right) \cdot 0.25\right) \cdot u1}{-1 - -0.5 \cdot u1}}\\ \end{array} \]
          6. Add Preprocessing

          Alternative 3: 97.7% accurate, 1.0× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right)\\ \mathbf{if}\;1 - u1 \leq 0.9943000078201294:\\ \;\;\;\;t\_0 \cdot \sqrt{-\log \left(1 - u1\right)}\\ \mathbf{else}:\\ \;\;\;\;t\_0 \cdot \sqrt{-\frac{1 \cdot u1}{-1 - -0.5 \cdot u1}}\\ \end{array} \end{array} \]
          (FPCore (cosTheta_i u1 u2)
           :precision binary32
           (let* ((t_0 (cos (* (* (PI) 2.0) u2))))
             (if (<= (- 1.0 u1) 0.9943000078201294)
               (* t_0 (sqrt (- (log (- 1.0 u1)))))
               (* t_0 (sqrt (- (/ (* 1.0 u1) (- -1.0 (* -0.5 u1)))))))))
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          t_0 := \cos \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right)\\
          \mathbf{if}\;1 - u1 \leq 0.9943000078201294:\\
          \;\;\;\;t\_0 \cdot \sqrt{-\log \left(1 - u1\right)}\\
          
          \mathbf{else}:\\
          \;\;\;\;t\_0 \cdot \sqrt{-\frac{1 \cdot u1}{-1 - -0.5 \cdot u1}}\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 2 regimes
          2. if (-.f32 #s(literal 1 binary32) u1) < 0.994300008

            1. Initial program 96.3%

              \[\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
            2. Add Preprocessing

            if 0.994300008 < (-.f32 #s(literal 1 binary32) u1)

            1. Initial program 44.5%

              \[\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
            2. Add Preprocessing
            3. Taylor expanded in u1 around 0

              \[\leadsto \sqrt{-\color{blue}{u1 \cdot \left(\frac{-1}{2} \cdot u1 - 1\right)}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
            4. Step-by-step derivation
              1. *-commutativeN/A

                \[\leadsto \sqrt{-\color{blue}{\left(\frac{-1}{2} \cdot u1 - 1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
              2. lower-*.f32N/A

                \[\leadsto \sqrt{-\color{blue}{\left(\frac{-1}{2} \cdot u1 - 1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
              3. sub-negN/A

                \[\leadsto \sqrt{-\color{blue}{\left(\frac{-1}{2} \cdot u1 + \left(\mathsf{neg}\left(1\right)\right)\right)} \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
              4. metadata-evalN/A

                \[\leadsto \sqrt{-\left(\frac{-1}{2} \cdot u1 + \color{blue}{-1}\right) \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
              5. lower-fma.f3269.7

                \[\leadsto \sqrt{-\color{blue}{\mathsf{fma}\left(-0.5, u1, -1\right)} \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
            5. Applied rewrites69.0%

              \[\leadsto \sqrt{-\color{blue}{\mathsf{fma}\left(-0.5, u1, -1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
            6. Step-by-step derivation
              1. Applied rewrites98.0%

                \[\leadsto \sqrt{-\frac{\left(1 - \left(u1 \cdot u1\right) \cdot 0.25\right) \cdot u1}{\color{blue}{-1 - -0.5 \cdot u1}}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
              2. Taylor expanded in u1 around 0

                \[\leadsto \sqrt{-\frac{1 \cdot u1}{-1 - \frac{-1}{2} \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
              3. Step-by-step derivation
                1. Applied rewrites98.5%

                  \[\leadsto \sqrt{-\frac{1 \cdot u1}{-1 - -0.5 \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
              4. Recombined 2 regimes into one program.
              5. Final simplification98.0%

                \[\leadsto \begin{array}{l} \mathbf{if}\;1 - u1 \leq 0.9943000078201294:\\ \;\;\;\;\cos \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right) \cdot \sqrt{-\log \left(1 - u1\right)}\\ \mathbf{else}:\\ \;\;\;\;\cos \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right) \cdot \sqrt{-\frac{1 \cdot u1}{-1 - -0.5 \cdot u1}}\\ \end{array} \]
              6. Add Preprocessing

              Alternative 4: 90.0% accurate, 1.5× speedup?

              \[\begin{array}{l} \\ \cos \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right) \cdot \sqrt{-\frac{1 \cdot u1}{-1 - -0.5 \cdot u1}} \end{array} \]
              (FPCore (cosTheta_i u1 u2)
               :precision binary32
               (* (cos (* (* (PI) 2.0) u2)) (sqrt (- (/ (* 1.0 u1) (- -1.0 (* -0.5 u1)))))))
              \begin{array}{l}
              
              \\
              \cos \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right) \cdot \sqrt{-\frac{1 \cdot u1}{-1 - -0.5 \cdot u1}}
              \end{array}
              
              Derivation
              1. Initial program 57.0%

                \[\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
              2. Add Preprocessing
              3. Taylor expanded in u1 around 0

                \[\leadsto \sqrt{-\color{blue}{u1 \cdot \left(\frac{-1}{2} \cdot u1 - 1\right)}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
              4. Step-by-step derivation
                1. *-commutativeN/A

                  \[\leadsto \sqrt{-\color{blue}{\left(\frac{-1}{2} \cdot u1 - 1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                2. lower-*.f32N/A

                  \[\leadsto \sqrt{-\color{blue}{\left(\frac{-1}{2} \cdot u1 - 1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                3. sub-negN/A

                  \[\leadsto \sqrt{-\color{blue}{\left(\frac{-1}{2} \cdot u1 + \left(\mathsf{neg}\left(1\right)\right)\right)} \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                4. metadata-evalN/A

                  \[\leadsto \sqrt{-\left(\frac{-1}{2} \cdot u1 + \color{blue}{-1}\right) \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                5. lower-fma.f3260.9

                  \[\leadsto \sqrt{-\color{blue}{\mathsf{fma}\left(-0.5, u1, -1\right)} \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
              5. Applied rewrites60.6%

                \[\leadsto \sqrt{-\color{blue}{\mathsf{fma}\left(-0.5, u1, -1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
              6. Step-by-step derivation
                1. Applied rewrites87.9%

                  \[\leadsto \sqrt{-\frac{\left(1 - \left(u1 \cdot u1\right) \cdot 0.25\right) \cdot u1}{\color{blue}{-1 - -0.5 \cdot u1}}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                2. Taylor expanded in u1 around 0

                  \[\leadsto \sqrt{-\frac{1 \cdot u1}{-1 - \frac{-1}{2} \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                3. Step-by-step derivation
                  1. Applied rewrites89.7%

                    \[\leadsto \sqrt{-\frac{1 \cdot u1}{-1 - -0.5 \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                  2. Final simplification89.7%

                    \[\leadsto \cos \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right) \cdot \sqrt{-\frac{1 \cdot u1}{-1 - -0.5 \cdot u1}} \]
                  3. Add Preprocessing

                  Alternative 5: 88.3% accurate, 1.7× speedup?

                  \[\begin{array}{l} \\ \sqrt{\left(0.5 \cdot u1\right) \cdot u1 + u1} \cdot \cos \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right) \end{array} \]
                  (FPCore (cosTheta_i u1 u2)
                   :precision binary32
                   (* (sqrt (+ (* (* 0.5 u1) u1) u1)) (cos (* (* (PI) 2.0) u2))))
                  \begin{array}{l}
                  
                  \\
                  \sqrt{\left(0.5 \cdot u1\right) \cdot u1 + u1} \cdot \cos \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right)
                  \end{array}
                  
                  Derivation
                  1. Initial program 57.0%

                    \[\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                  2. Add Preprocessing
                  3. Taylor expanded in u1 around 0

                    \[\leadsto \sqrt{-\color{blue}{-1 \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                  4. Step-by-step derivation
                    1. mul-1-negN/A

                      \[\leadsto \sqrt{-\color{blue}{\left(\mathsf{neg}\left(u1\right)\right)}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                    2. lower-neg.f3276.5

                      \[\leadsto \sqrt{-\color{blue}{\left(-u1\right)}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                  5. Applied rewrites76.5%

                    \[\leadsto \sqrt{-\color{blue}{\left(-u1\right)}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                  6. Taylor expanded in u1 around 0

                    \[\leadsto \sqrt{\color{blue}{u1 \cdot \left(1 + \frac{1}{2} \cdot u1\right)}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                  7. Step-by-step derivation
                    1. *-commutativeN/A

                      \[\leadsto \sqrt{\color{blue}{\left(1 + \frac{1}{2} \cdot u1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                    2. lft-mult-inverseN/A

                      \[\leadsto \sqrt{\left(\color{blue}{\frac{1}{u1} \cdot u1} + \frac{1}{2} \cdot u1\right) \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                    3. distribute-rgt-inN/A

                      \[\leadsto \sqrt{\color{blue}{\left(u1 \cdot \left(\frac{1}{u1} + \frac{1}{2}\right)\right)} \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                    4. +-commutativeN/A

                      \[\leadsto \sqrt{\left(u1 \cdot \color{blue}{\left(\frac{1}{2} + \frac{1}{u1}\right)}\right) \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                    5. lower-*.f32N/A

                      \[\leadsto \sqrt{\color{blue}{\left(u1 \cdot \left(\frac{1}{2} + \frac{1}{u1}\right)\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                    6. distribute-rgt-inN/A

                      \[\leadsto \sqrt{\color{blue}{\left(\frac{1}{2} \cdot u1 + \frac{1}{u1} \cdot u1\right)} \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                    7. lft-mult-inverseN/A

                      \[\leadsto \sqrt{\left(\frac{1}{2} \cdot u1 + \color{blue}{1}\right) \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                    8. lower-fma.f3261.9

                      \[\leadsto \sqrt{\color{blue}{\mathsf{fma}\left(0.5, u1, 1\right)} \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                  8. Applied rewrites61.2%

                    \[\leadsto \sqrt{\color{blue}{\mathsf{fma}\left(0.5, u1, 1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                  9. Step-by-step derivation
                    1. Applied rewrites87.9%

                      \[\leadsto \sqrt{\left(0.5 \cdot u1\right) \cdot u1 + \color{blue}{u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                    2. Final simplification87.9%

                      \[\leadsto \sqrt{\left(0.5 \cdot u1\right) \cdot u1 + u1} \cdot \cos \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right) \]
                    3. Add Preprocessing

                    Alternative 6: 88.2% accurate, 1.7× speedup?

                    \[\begin{array}{l} \\ \sqrt{\left(1 - -0.5 \cdot u1\right) \cdot u1} \cdot \cos \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right) \end{array} \]
                    (FPCore (cosTheta_i u1 u2)
                     :precision binary32
                     (* (sqrt (* (- 1.0 (* -0.5 u1)) u1)) (cos (* (* (PI) 2.0) u2))))
                    \begin{array}{l}
                    
                    \\
                    \sqrt{\left(1 - -0.5 \cdot u1\right) \cdot u1} \cdot \cos \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right)
                    \end{array}
                    
                    Derivation
                    1. Initial program 57.0%

                      \[\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                    2. Add Preprocessing
                    3. Taylor expanded in u1 around 0

                      \[\leadsto \sqrt{-\color{blue}{-1 \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                    4. Step-by-step derivation
                      1. mul-1-negN/A

                        \[\leadsto \sqrt{-\color{blue}{\left(\mathsf{neg}\left(u1\right)\right)}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                      2. lower-neg.f3276.5

                        \[\leadsto \sqrt{-\color{blue}{\left(-u1\right)}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                    5. Applied rewrites76.5%

                      \[\leadsto \sqrt{-\color{blue}{\left(-u1\right)}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                    6. Taylor expanded in u1 around 0

                      \[\leadsto \sqrt{\color{blue}{u1 \cdot \left(1 + \frac{1}{2} \cdot u1\right)}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                    7. Step-by-step derivation
                      1. *-commutativeN/A

                        \[\leadsto \sqrt{\color{blue}{\left(1 + \frac{1}{2} \cdot u1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                      2. lft-mult-inverseN/A

                        \[\leadsto \sqrt{\left(\color{blue}{\frac{1}{u1} \cdot u1} + \frac{1}{2} \cdot u1\right) \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                      3. distribute-rgt-inN/A

                        \[\leadsto \sqrt{\color{blue}{\left(u1 \cdot \left(\frac{1}{u1} + \frac{1}{2}\right)\right)} \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                      4. +-commutativeN/A

                        \[\leadsto \sqrt{\left(u1 \cdot \color{blue}{\left(\frac{1}{2} + \frac{1}{u1}\right)}\right) \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                      5. lower-*.f32N/A

                        \[\leadsto \sqrt{\color{blue}{\left(u1 \cdot \left(\frac{1}{2} + \frac{1}{u1}\right)\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                      6. distribute-rgt-inN/A

                        \[\leadsto \sqrt{\color{blue}{\left(\frac{1}{2} \cdot u1 + \frac{1}{u1} \cdot u1\right)} \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                      7. lft-mult-inverseN/A

                        \[\leadsto \sqrt{\left(\frac{1}{2} \cdot u1 + \color{blue}{1}\right) \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                      8. lower-fma.f3261.2

                        \[\leadsto \sqrt{\color{blue}{\mathsf{fma}\left(0.5, u1, 1\right)} \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                    8. Applied rewrites61.6%

                      \[\leadsto \sqrt{\color{blue}{\mathsf{fma}\left(0.5, u1, 1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                    9. Step-by-step derivation
                      1. Applied rewrites87.8%

                        \[\leadsto \sqrt{\left(1 - u1 \cdot -0.5\right) \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                      2. Final simplification87.8%

                        \[\leadsto \sqrt{\left(1 - -0.5 \cdot u1\right) \cdot u1} \cdot \cos \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right) \]
                      3. Add Preprocessing

                      Alternative 7: 72.4% accurate, 4.2× speedup?

                      \[\begin{array}{l} \\ 1 \cdot \sqrt{-\frac{\left(1 - \left(u1 \cdot u1\right) \cdot 0.25\right) \cdot u1}{-1 - -0.5 \cdot u1}} \end{array} \]
                      (FPCore (cosTheta_i u1 u2)
                       :precision binary32
                       (* 1.0 (sqrt (- (/ (* (- 1.0 (* (* u1 u1) 0.25)) u1) (- -1.0 (* -0.5 u1)))))))
                      float code(float cosTheta_i, float u1, float u2) {
                      	return 1.0f * sqrtf(-(((1.0f - ((u1 * u1) * 0.25f)) * u1) / (-1.0f - (-0.5f * u1))));
                      }
                      
                      real(4) function code(costheta_i, u1, u2)
                          real(4), intent (in) :: costheta_i
                          real(4), intent (in) :: u1
                          real(4), intent (in) :: u2
                          code = 1.0e0 * sqrt(-(((1.0e0 - ((u1 * u1) * 0.25e0)) * u1) / ((-1.0e0) - ((-0.5e0) * u1))))
                      end function
                      
                      function code(cosTheta_i, u1, u2)
                      	return Float32(Float32(1.0) * sqrt(Float32(-Float32(Float32(Float32(Float32(1.0) - Float32(Float32(u1 * u1) * Float32(0.25))) * u1) / Float32(Float32(-1.0) - Float32(Float32(-0.5) * u1))))))
                      end
                      
                      function tmp = code(cosTheta_i, u1, u2)
                      	tmp = single(1.0) * sqrt(-(((single(1.0) - ((u1 * u1) * single(0.25))) * u1) / (single(-1.0) - (single(-0.5) * u1))));
                      end
                      
                      \begin{array}{l}
                      
                      \\
                      1 \cdot \sqrt{-\frac{\left(1 - \left(u1 \cdot u1\right) \cdot 0.25\right) \cdot u1}{-1 - -0.5 \cdot u1}}
                      \end{array}
                      
                      Derivation
                      1. Initial program 57.0%

                        \[\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                      2. Add Preprocessing
                      3. Taylor expanded in u1 around 0

                        \[\leadsto \sqrt{-\color{blue}{u1 \cdot \left(\frac{-1}{2} \cdot u1 - 1\right)}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                      4. Step-by-step derivation
                        1. *-commutativeN/A

                          \[\leadsto \sqrt{-\color{blue}{\left(\frac{-1}{2} \cdot u1 - 1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                        2. lower-*.f32N/A

                          \[\leadsto \sqrt{-\color{blue}{\left(\frac{-1}{2} \cdot u1 - 1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                        3. sub-negN/A

                          \[\leadsto \sqrt{-\color{blue}{\left(\frac{-1}{2} \cdot u1 + \left(\mathsf{neg}\left(1\right)\right)\right)} \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                        4. metadata-evalN/A

                          \[\leadsto \sqrt{-\left(\frac{-1}{2} \cdot u1 + \color{blue}{-1}\right) \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                        5. lower-fma.f3260.8

                          \[\leadsto \sqrt{-\color{blue}{\mathsf{fma}\left(-0.5, u1, -1\right)} \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                      5. Applied rewrites61.0%

                        \[\leadsto \sqrt{-\color{blue}{\mathsf{fma}\left(-0.5, u1, -1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                      6. Step-by-step derivation
                        1. Applied rewrites87.9%

                          \[\leadsto \sqrt{-\frac{\left(1 - \left(u1 \cdot u1\right) \cdot 0.25\right) \cdot u1}{\color{blue}{-1 - -0.5 \cdot u1}}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                        2. Taylor expanded in u2 around 0

                          \[\leadsto \sqrt{-\frac{\left(1 - \left(u1 \cdot u1\right) \cdot \frac{1}{4}\right) \cdot u1}{-1 - \frac{-1}{2} \cdot u1}} \cdot \color{blue}{1} \]
                        3. Step-by-step derivation
                          1. Applied rewrites73.4%

                            \[\leadsto \sqrt{-\frac{\left(1 - \left(u1 \cdot u1\right) \cdot 0.25\right) \cdot u1}{-1 - -0.5 \cdot u1}} \cdot \color{blue}{1} \]
                          2. Final simplification73.4%

                            \[\leadsto 1 \cdot \sqrt{-\frac{\left(1 - \left(u1 \cdot u1\right) \cdot 0.25\right) \cdot u1}{-1 - -0.5 \cdot u1}} \]
                          3. Add Preprocessing

                          Alternative 8: 72.4% accurate, 7.5× speedup?

                          \[\begin{array}{l} \\ \sqrt{-\left(-0.5 \cdot u1 - 1\right) \cdot u1} \cdot 1 \end{array} \]
                          (FPCore (cosTheta_i u1 u2)
                           :precision binary32
                           (* (sqrt (- (* (- (* -0.5 u1) 1.0) u1))) 1.0))
                          float code(float cosTheta_i, float u1, float u2) {
                          	return sqrtf(-(((-0.5f * u1) - 1.0f) * u1)) * 1.0f;
                          }
                          
                          real(4) function code(costheta_i, u1, u2)
                              real(4), intent (in) :: costheta_i
                              real(4), intent (in) :: u1
                              real(4), intent (in) :: u2
                              code = sqrt(-((((-0.5e0) * u1) - 1.0e0) * u1)) * 1.0e0
                          end function
                          
                          function code(cosTheta_i, u1, u2)
                          	return Float32(sqrt(Float32(-Float32(Float32(Float32(Float32(-0.5) * u1) - Float32(1.0)) * u1))) * Float32(1.0))
                          end
                          
                          function tmp = code(cosTheta_i, u1, u2)
                          	tmp = sqrt(-(((single(-0.5) * u1) - single(1.0)) * u1)) * single(1.0);
                          end
                          
                          \begin{array}{l}
                          
                          \\
                          \sqrt{-\left(-0.5 \cdot u1 - 1\right) \cdot u1} \cdot 1
                          \end{array}
                          
                          Derivation
                          1. Initial program 57.0%

                            \[\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                          2. Add Preprocessing
                          3. Taylor expanded in u1 around 0

                            \[\leadsto \sqrt{-\color{blue}{u1 \cdot \left(\frac{-1}{2} \cdot u1 - 1\right)}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                          4. Step-by-step derivation
                            1. *-commutativeN/A

                              \[\leadsto \sqrt{-\color{blue}{\left(\frac{-1}{2} \cdot u1 - 1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                            2. lower-*.f32N/A

                              \[\leadsto \sqrt{-\color{blue}{\left(\frac{-1}{2} \cdot u1 - 1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                            3. sub-negN/A

                              \[\leadsto \sqrt{-\color{blue}{\left(\frac{-1}{2} \cdot u1 + \left(\mathsf{neg}\left(1\right)\right)\right)} \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                            4. metadata-evalN/A

                              \[\leadsto \sqrt{-\left(\frac{-1}{2} \cdot u1 + \color{blue}{-1}\right) \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                            5. lower-fma.f3260.4

                              \[\leadsto \sqrt{-\color{blue}{\mathsf{fma}\left(-0.5, u1, -1\right)} \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                          5. Applied rewrites60.4%

                            \[\leadsto \sqrt{-\color{blue}{\mathsf{fma}\left(-0.5, u1, -1\right) \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                          6. Step-by-step derivation
                            1. Applied rewrites87.8%

                              \[\leadsto \sqrt{-\left(-0.5 \cdot u1 - 1\right) \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                            2. Taylor expanded in u2 around 0

                              \[\leadsto \sqrt{-\left(\frac{-1}{2} \cdot u1 - 1\right) \cdot u1} \cdot \color{blue}{1} \]
                            3. Step-by-step derivation
                              1. Applied rewrites73.3%

                                \[\leadsto \sqrt{-\left(-0.5 \cdot u1 - 1\right) \cdot u1} \cdot \color{blue}{1} \]
                              2. Add Preprocessing

                              Alternative 9: 64.5% accurate, 11.6× speedup?

                              \[\begin{array}{l} \\ \sqrt{-\left(-u1\right)} \cdot 1 \end{array} \]
                              (FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (- u1))) 1.0))
                              float code(float cosTheta_i, float u1, float u2) {
                              	return sqrtf(-(-u1)) * 1.0f;
                              }
                              
                              real(4) function code(costheta_i, u1, u2)
                                  real(4), intent (in) :: costheta_i
                                  real(4), intent (in) :: u1
                                  real(4), intent (in) :: u2
                                  code = sqrt(-(-u1)) * 1.0e0
                              end function
                              
                              function code(cosTheta_i, u1, u2)
                              	return Float32(sqrt(Float32(-Float32(-u1))) * Float32(1.0))
                              end
                              
                              function tmp = code(cosTheta_i, u1, u2)
                              	tmp = sqrt(-(-u1)) * single(1.0);
                              end
                              
                              \begin{array}{l}
                              
                              \\
                              \sqrt{-\left(-u1\right)} \cdot 1
                              \end{array}
                              
                              Derivation
                              1. Initial program 57.0%

                                \[\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                              2. Add Preprocessing
                              3. Taylor expanded in u1 around 0

                                \[\leadsto \sqrt{-\color{blue}{-1 \cdot u1}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                              4. Step-by-step derivation
                                1. mul-1-negN/A

                                  \[\leadsto \sqrt{-\color{blue}{\left(\mathsf{neg}\left(u1\right)\right)}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                                2. lower-neg.f3276.5

                                  \[\leadsto \sqrt{-\color{blue}{\left(-u1\right)}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                              5. Applied rewrites76.5%

                                \[\leadsto \sqrt{-\color{blue}{\left(-u1\right)}} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                              6. Taylor expanded in u2 around 0

                                \[\leadsto \sqrt{-\left(-u1\right)} \cdot \color{blue}{1} \]
                              7. Step-by-step derivation
                                1. Applied rewrites65.8%

                                  \[\leadsto \sqrt{-\left(-u1\right)} \cdot \color{blue}{1} \]
                                2. Add Preprocessing

                                Alternative 10: 5.0% accurate, 12.8× speedup?

                                \[\begin{array}{l} \\ \left(-\sqrt{u1}\right) \cdot 1 \end{array} \]
                                (FPCore (cosTheta_i u1 u2) :precision binary32 (* (- (sqrt u1)) 1.0))
                                float code(float cosTheta_i, float u1, float u2) {
                                	return -sqrtf(u1) * 1.0f;
                                }
                                
                                real(4) function code(costheta_i, u1, u2)
                                    real(4), intent (in) :: costheta_i
                                    real(4), intent (in) :: u1
                                    real(4), intent (in) :: u2
                                    code = -sqrt(u1) * 1.0e0
                                end function
                                
                                function code(cosTheta_i, u1, u2)
                                	return Float32(Float32(-sqrt(u1)) * Float32(1.0))
                                end
                                
                                function tmp = code(cosTheta_i, u1, u2)
                                	tmp = -sqrt(u1) * single(1.0);
                                end
                                
                                \begin{array}{l}
                                
                                \\
                                \left(-\sqrt{u1}\right) \cdot 1
                                \end{array}
                                
                                Derivation
                                1. Initial program 57.0%

                                  \[\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                                2. Add Preprocessing
                                3. Taylor expanded in u1 around 0

                                  \[\leadsto \color{blue}{\left(\sqrt{u1} \cdot {\left(\sqrt{-1}\right)}^{2}\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                                4. Step-by-step derivation
                                  1. *-commutativeN/A

                                    \[\leadsto \color{blue}{\left({\left(\sqrt{-1}\right)}^{2} \cdot \sqrt{u1}\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                                  2. unpow2N/A

                                    \[\leadsto \left(\color{blue}{\left(\sqrt{-1} \cdot \sqrt{-1}\right)} \cdot \sqrt{u1}\right) \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                                  3. rem-square-sqrtN/A

                                    \[\leadsto \left(\color{blue}{-1} \cdot \sqrt{u1}\right) \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                                  4. mul-1-negN/A

                                    \[\leadsto \color{blue}{\left(\mathsf{neg}\left(\sqrt{u1}\right)\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                                  5. lower-neg.f32N/A

                                    \[\leadsto \color{blue}{\left(-\sqrt{u1}\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                                  6. lower-sqrt.f323.5

                                    \[\leadsto \left(-\color{blue}{\sqrt{u1}}\right) \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                                5. Applied rewrites3.5%

                                  \[\leadsto \color{blue}{\left(-\sqrt{u1}\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \]
                                6. Taylor expanded in u2 around 0

                                  \[\leadsto \left(-\sqrt{u1}\right) \cdot \color{blue}{1} \]
                                7. Step-by-step derivation
                                  1. Applied rewrites4.9%

                                    \[\leadsto \left(-\sqrt{u1}\right) \cdot \color{blue}{1} \]
                                  2. Add Preprocessing

                                  Reproduce

                                  ?
                                  herbie shell --seed 2024267 
                                  (FPCore (cosTheta_i u1 u2)
                                    :name "Beckmann Sample, near normal, slope_x"
                                    :precision binary32
                                    :pre (and (and (and (> cosTheta_i 0.9999) (<= cosTheta_i 1.0)) (and (<= 2.328306437e-10 u1) (<= u1 1.0))) (and (<= 2.328306437e-10 u2) (<= u2 1.0)))
                                    (* (sqrt (- (log (- 1.0 u1)))) (cos (* (* 2.0 (PI)) u2))))