Trowbridge-Reitz Sample, near normal, slope_x

Percentage Accurate: 99.0% → 99.1%
Time: 6.8s
Alternatives: 7
Speedup: 1.0×

Specification

?
\[\left(\left(cosTheta\_i > 0.9999 \land cosTheta\_i \leq 1\right) \land \left(2.328306437 \cdot 10^{-10} \leq u1 \land u1 \leq 1\right)\right) \land \left(2.328306437 \cdot 10^{-10} \leq u2 \land u2 \leq 1\right)\]
\[\begin{array}{l} \\ \sqrt{\frac{u1}{1 - u1}} \cdot \cos \left(6.28318530718 \cdot u2\right) \end{array} \]
(FPCore (cosTheta_i u1 u2)
 :precision binary32
 (* (sqrt (/ u1 (- 1.0 u1))) (cos (* 6.28318530718 u2))))
float code(float cosTheta_i, float u1, float u2) {
	return sqrtf((u1 / (1.0f - u1))) * cosf((6.28318530718f * u2));
}
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 - u1))) * cos((6.28318530718e0 * u2))
end function
function code(cosTheta_i, u1, u2)
	return Float32(sqrt(Float32(u1 / Float32(Float32(1.0) - u1))) * cos(Float32(Float32(6.28318530718) * u2)))
end
function tmp = code(cosTheta_i, u1, u2)
	tmp = sqrt((u1 / (single(1.0) - u1))) * cos((single(6.28318530718) * u2));
end
\begin{array}{l}

\\
\sqrt{\frac{u1}{1 - u1}} \cdot \cos \left(6.28318530718 \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 7 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 99.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \sqrt{\frac{u1}{1 - u1}} \cdot \cos \left(6.28318530718 \cdot u2\right) \end{array} \]
(FPCore (cosTheta_i u1 u2)
 :precision binary32
 (* (sqrt (/ u1 (- 1.0 u1))) (cos (* 6.28318530718 u2))))
float code(float cosTheta_i, float u1, float u2) {
	return sqrtf((u1 / (1.0f - u1))) * cosf((6.28318530718f * u2));
}
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 - u1))) * cos((6.28318530718e0 * u2))
end function
function code(cosTheta_i, u1, u2)
	return Float32(sqrt(Float32(u1 / Float32(Float32(1.0) - u1))) * cos(Float32(Float32(6.28318530718) * u2)))
end
function tmp = code(cosTheta_i, u1, u2)
	tmp = sqrt((u1 / (single(1.0) - u1))) * cos((single(6.28318530718) * u2));
end
\begin{array}{l}

\\
\sqrt{\frac{u1}{1 - u1}} \cdot \cos \left(6.28318530718 \cdot u2\right)
\end{array}

Alternative 1: 99.1% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \sin \left(\mathsf{PI}\left(\right) \cdot 0.5 - 6.28318530718 \cdot u2\right) \cdot \sqrt{\frac{u1}{1 - u1}} \end{array} \]
(FPCore (cosTheta_i u1 u2)
 :precision binary32
 (* (sin (- (* (PI) 0.5) (* 6.28318530718 u2))) (sqrt (/ u1 (- 1.0 u1)))))
\begin{array}{l}

\\
\sin \left(\mathsf{PI}\left(\right) \cdot 0.5 - 6.28318530718 \cdot u2\right) \cdot \sqrt{\frac{u1}{1 - u1}}
\end{array}
Derivation
  1. Initial program 98.7%

    \[\sqrt{\frac{u1}{1 - u1}} \cdot \cos \left(6.28318530718 \cdot u2\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-/.f32N/A

      \[\leadsto \sqrt{\color{blue}{\frac{u1}{1 - u1}}} \cdot \cos \left(\frac{314159265359}{50000000000} \cdot u2\right) \]
    2. clear-numN/A

      \[\leadsto \sqrt{\color{blue}{\frac{1}{\frac{1 - u1}{u1}}}} \cdot \cos \left(\frac{314159265359}{50000000000} \cdot u2\right) \]
    3. associate-/r/N/A

      \[\leadsto \sqrt{\color{blue}{\frac{1}{1 - u1} \cdot u1}} \cdot \cos \left(\frac{314159265359}{50000000000} \cdot u2\right) \]
    4. lower-*.f32N/A

      \[\leadsto \sqrt{\color{blue}{\frac{1}{1 - u1} \cdot u1}} \cdot \cos \left(\frac{314159265359}{50000000000} \cdot u2\right) \]
    5. frac-2negN/A

      \[\leadsto \sqrt{\color{blue}{\frac{\mathsf{neg}\left(1\right)}{\mathsf{neg}\left(\left(1 - u1\right)\right)}} \cdot u1} \cdot \cos \left(\frac{314159265359}{50000000000} \cdot u2\right) \]
    6. metadata-evalN/A

      \[\leadsto \sqrt{\frac{\color{blue}{-1}}{\mathsf{neg}\left(\left(1 - u1\right)\right)} \cdot u1} \cdot \cos \left(\frac{314159265359}{50000000000} \cdot u2\right) \]
    7. lower-/.f32N/A

      \[\leadsto \sqrt{\color{blue}{\frac{-1}{\mathsf{neg}\left(\left(1 - u1\right)\right)}} \cdot u1} \cdot \cos \left(\frac{314159265359}{50000000000} \cdot u2\right) \]
    8. neg-sub0N/A

      \[\leadsto \sqrt{\frac{-1}{\color{blue}{0 - \left(1 - u1\right)}} \cdot u1} \cdot \cos \left(\frac{314159265359}{50000000000} \cdot u2\right) \]
    9. lift--.f32N/A

      \[\leadsto \sqrt{\frac{-1}{0 - \color{blue}{\left(1 - u1\right)}} \cdot u1} \cdot \cos \left(\frac{314159265359}{50000000000} \cdot u2\right) \]
    10. sub-negN/A

      \[\leadsto \sqrt{\frac{-1}{0 - \color{blue}{\left(1 + \left(\mathsf{neg}\left(u1\right)\right)\right)}} \cdot u1} \cdot \cos \left(\frac{314159265359}{50000000000} \cdot u2\right) \]
    11. +-commutativeN/A

      \[\leadsto \sqrt{\frac{-1}{0 - \color{blue}{\left(\left(\mathsf{neg}\left(u1\right)\right) + 1\right)}} \cdot u1} \cdot \cos \left(\frac{314159265359}{50000000000} \cdot u2\right) \]
    12. associate--r+N/A

      \[\leadsto \sqrt{\frac{-1}{\color{blue}{\left(0 - \left(\mathsf{neg}\left(u1\right)\right)\right) - 1}} \cdot u1} \cdot \cos \left(\frac{314159265359}{50000000000} \cdot u2\right) \]
    13. neg-sub0N/A

      \[\leadsto \sqrt{\frac{-1}{\color{blue}{\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(u1\right)\right)\right)\right)} - 1} \cdot u1} \cdot \cos \left(\frac{314159265359}{50000000000} \cdot u2\right) \]
    14. remove-double-negN/A

      \[\leadsto \sqrt{\frac{-1}{\color{blue}{u1} - 1} \cdot u1} \cdot \cos \left(\frac{314159265359}{50000000000} \cdot u2\right) \]
    15. lower--.f3298.6

      \[\leadsto \sqrt{\frac{-1}{\color{blue}{u1 - 1}} \cdot u1} \cdot \cos \left(6.28318530718 \cdot u2\right) \]
  4. Applied rewrites98.6%

    \[\leadsto \sqrt{\color{blue}{\frac{-1}{u1 - 1} \cdot u1}} \cdot \cos \left(6.28318530718 \cdot u2\right) \]
  5. Step-by-step derivation
    1. lift-cos.f32N/A

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \color{blue}{\cos \left(\frac{314159265359}{50000000000} \cdot u2\right)} \]
    2. cos-neg-revN/A

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \color{blue}{\cos \left(\mathsf{neg}\left(\frac{314159265359}{50000000000} \cdot u2\right)\right)} \]
    3. lift-*.f32N/A

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \cos \left(\mathsf{neg}\left(\color{blue}{\frac{314159265359}{50000000000} \cdot u2}\right)\right) \]
    4. distribute-lft-neg-inN/A

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \cos \color{blue}{\left(\left(\mathsf{neg}\left(\frac{314159265359}{50000000000}\right)\right) \cdot u2\right)} \]
    5. metadata-evalN/A

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \cos \left(\color{blue}{\frac{-314159265359}{50000000000}} \cdot u2\right) \]
    6. lift-*.f32N/A

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \cos \color{blue}{\left(\frac{-314159265359}{50000000000} \cdot u2\right)} \]
    7. lift-cos.f3298.6

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \color{blue}{\cos \left(-6.28318530718 \cdot u2\right)} \]
    8. remove-double-negN/A

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \color{blue}{\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(\cos \left(\frac{-314159265359}{50000000000} \cdot u2\right)\right)\right)\right)\right)} \]
    9. lift-cos.f32N/A

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \left(\mathsf{neg}\left(\left(\mathsf{neg}\left(\color{blue}{\cos \left(\frac{-314159265359}{50000000000} \cdot u2\right)}\right)\right)\right)\right) \]
    10. sin-+PI/2-revN/A

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \left(\mathsf{neg}\left(\left(\mathsf{neg}\left(\color{blue}{\sin \left(\frac{-314159265359}{50000000000} \cdot u2 + \frac{\mathsf{PI}\left(\right)}{2}\right)}\right)\right)\right)\right) \]
    11. sin-neg-revN/A

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \left(\mathsf{neg}\left(\color{blue}{\sin \left(\mathsf{neg}\left(\left(\frac{-314159265359}{50000000000} \cdot u2 + \frac{\mathsf{PI}\left(\right)}{2}\right)\right)\right)}\right)\right) \]
    12. sin-neg-revN/A

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \color{blue}{\sin \left(\mathsf{neg}\left(\left(\mathsf{neg}\left(\left(\frac{-314159265359}{50000000000} \cdot u2 + \frac{\mathsf{PI}\left(\right)}{2}\right)\right)\right)\right)\right)} \]
    13. distribute-neg-inN/A

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \sin \left(\mathsf{neg}\left(\color{blue}{\left(\left(\mathsf{neg}\left(\frac{-314159265359}{50000000000} \cdot u2\right)\right) + \left(\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{2}\right)\right)\right)}\right)\right) \]
    14. lift-*.f32N/A

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \sin \left(\mathsf{neg}\left(\left(\left(\mathsf{neg}\left(\color{blue}{\frac{-314159265359}{50000000000} \cdot u2}\right)\right) + \left(\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{2}\right)\right)\right)\right)\right) \]
    15. distribute-lft-neg-inN/A

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \sin \left(\mathsf{neg}\left(\left(\color{blue}{\left(\mathsf{neg}\left(\frac{-314159265359}{50000000000}\right)\right) \cdot u2} + \left(\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{2}\right)\right)\right)\right)\right) \]
    16. metadata-evalN/A

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \sin \left(\mathsf{neg}\left(\left(\color{blue}{\frac{314159265359}{50000000000}} \cdot u2 + \left(\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{2}\right)\right)\right)\right)\right) \]
    17. lift-*.f32N/A

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \sin \left(\mathsf{neg}\left(\left(\color{blue}{\frac{314159265359}{50000000000} \cdot u2} + \left(\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{2}\right)\right)\right)\right)\right) \]
    18. sub-negN/A

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \sin \left(\mathsf{neg}\left(\color{blue}{\left(\frac{314159265359}{50000000000} \cdot u2 - \frac{\mathsf{PI}\left(\right)}{2}\right)}\right)\right) \]
    19. lower-sin.f32N/A

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \color{blue}{\sin \left(\mathsf{neg}\left(\left(\frac{314159265359}{50000000000} \cdot u2 - \frac{\mathsf{PI}\left(\right)}{2}\right)\right)\right)} \]
    20. lower-neg.f32N/A

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \sin \color{blue}{\left(-\left(\frac{314159265359}{50000000000} \cdot u2 - \frac{\mathsf{PI}\left(\right)}{2}\right)\right)} \]
    21. lower--.f32N/A

      \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \sin \left(-\color{blue}{\left(\frac{314159265359}{50000000000} \cdot u2 - \frac{\mathsf{PI}\left(\right)}{2}\right)}\right) \]
  6. Applied rewrites98.7%

    \[\leadsto \sqrt{\frac{-1}{u1 - 1} \cdot u1} \cdot \color{blue}{\sin \left(-\left(u2 \cdot 6.28318530718 - 0.5 \cdot \mathsf{PI}\left(\right)\right)\right)} \]
  7. Step-by-step derivation
    1. lift-*.f32N/A

      \[\leadsto \sqrt{\color{blue}{\frac{-1}{u1 - 1} \cdot u1}} \cdot \sin \left(-\left(u2 \cdot \frac{314159265359}{50000000000} - \frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)\right) \]
    2. *-commutativeN/A

      \[\leadsto \sqrt{\color{blue}{u1 \cdot \frac{-1}{u1 - 1}}} \cdot \sin \left(-\left(u2 \cdot \frac{314159265359}{50000000000} - \frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)\right) \]
    3. lift-/.f32N/A

      \[\leadsto \sqrt{u1 \cdot \color{blue}{\frac{-1}{u1 - 1}}} \cdot \sin \left(-\left(u2 \cdot \frac{314159265359}{50000000000} - \frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)\right) \]
    4. frac-2negN/A

      \[\leadsto \sqrt{u1 \cdot \color{blue}{\frac{\mathsf{neg}\left(-1\right)}{\mathsf{neg}\left(\left(u1 - 1\right)\right)}}} \cdot \sin \left(-\left(u2 \cdot \frac{314159265359}{50000000000} - \frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)\right) \]
    5. metadata-evalN/A

      \[\leadsto \sqrt{u1 \cdot \frac{\color{blue}{1}}{\mathsf{neg}\left(\left(u1 - 1\right)\right)}} \cdot \sin \left(-\left(u2 \cdot \frac{314159265359}{50000000000} - \frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)\right) \]
    6. un-div-invN/A

      \[\leadsto \sqrt{\color{blue}{\frac{u1}{\mathsf{neg}\left(\left(u1 - 1\right)\right)}}} \cdot \sin \left(-\left(u2 \cdot \frac{314159265359}{50000000000} - \frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)\right) \]
    7. lift--.f32N/A

      \[\leadsto \sqrt{\frac{u1}{\mathsf{neg}\left(\color{blue}{\left(u1 - 1\right)}\right)}} \cdot \sin \left(-\left(u2 \cdot \frac{314159265359}{50000000000} - \frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)\right) \]
    8. sub-negN/A

      \[\leadsto \sqrt{\frac{u1}{\mathsf{neg}\left(\color{blue}{\left(u1 + \left(\mathsf{neg}\left(1\right)\right)\right)}\right)}} \cdot \sin \left(-\left(u2 \cdot \frac{314159265359}{50000000000} - \frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)\right) \]
    9. metadata-evalN/A

      \[\leadsto \sqrt{\frac{u1}{\mathsf{neg}\left(\left(u1 + \color{blue}{-1}\right)\right)}} \cdot \sin \left(-\left(u2 \cdot \frac{314159265359}{50000000000} - \frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)\right) \]
    10. distribute-neg-inN/A

      \[\leadsto \sqrt{\frac{u1}{\color{blue}{\left(\mathsf{neg}\left(u1\right)\right) + \left(\mathsf{neg}\left(-1\right)\right)}}} \cdot \sin \left(-\left(u2 \cdot \frac{314159265359}{50000000000} - \frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)\right) \]
    11. metadata-evalN/A

      \[\leadsto \sqrt{\frac{u1}{\left(\mathsf{neg}\left(u1\right)\right) + \color{blue}{1}}} \cdot \sin \left(-\left(u2 \cdot \frac{314159265359}{50000000000} - \frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)\right) \]
    12. +-commutativeN/A

      \[\leadsto \sqrt{\frac{u1}{\color{blue}{1 + \left(\mathsf{neg}\left(u1\right)\right)}}} \cdot \sin \left(-\left(u2 \cdot \frac{314159265359}{50000000000} - \frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)\right) \]
    13. sub-negN/A

      \[\leadsto \sqrt{\frac{u1}{\color{blue}{1 - u1}}} \cdot \sin \left(-\left(u2 \cdot \frac{314159265359}{50000000000} - \frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)\right) \]
    14. lift--.f32N/A

      \[\leadsto \sqrt{\frac{u1}{\color{blue}{1 - u1}}} \cdot \sin \left(-\left(u2 \cdot \frac{314159265359}{50000000000} - \frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)\right) \]
    15. lower-/.f3298.9

      \[\leadsto \sqrt{\color{blue}{\frac{u1}{1 - u1}}} \cdot \sin \left(-\left(u2 \cdot 6.28318530718 - 0.5 \cdot \mathsf{PI}\left(\right)\right)\right) \]
  8. Applied rewrites98.9%

    \[\leadsto \sqrt{\color{blue}{\frac{u1}{1 - u1}}} \cdot \sin \left(-\left(u2 \cdot 6.28318530718 - 0.5 \cdot \mathsf{PI}\left(\right)\right)\right) \]
  9. Final simplification98.9%

    \[\leadsto \sin \left(\mathsf{PI}\left(\right) \cdot 0.5 - 6.28318530718 \cdot u2\right) \cdot \sqrt{\frac{u1}{1 - u1}} \]
  10. Add Preprocessing

Alternative 2: 90.1% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos \left(6.28318530718 \cdot u2\right)\\ \mathbf{if}\;t\_0 \leq 0.9999399781227112:\\ \;\;\;\;\sqrt{u1} \cdot t\_0\\ \mathbf{else}:\\ \;\;\;\;\sqrt{\frac{u1}{1 - u1}}\\ \end{array} \end{array} \]
(FPCore (cosTheta_i u1 u2)
 :precision binary32
 (let* ((t_0 (cos (* 6.28318530718 u2))))
   (if (<= t_0 0.9999399781227112)
     (* (sqrt u1) t_0)
     (sqrt (/ u1 (- 1.0 u1))))))
float code(float cosTheta_i, float u1, float u2) {
	float t_0 = cosf((6.28318530718f * u2));
	float tmp;
	if (t_0 <= 0.9999399781227112f) {
		tmp = sqrtf(u1) * t_0;
	} else {
		tmp = sqrtf((u1 / (1.0f - u1)));
	}
	return tmp;
}
real(4) function code(costheta_i, u1, u2)
    real(4), intent (in) :: costheta_i
    real(4), intent (in) :: u1
    real(4), intent (in) :: u2
    real(4) :: t_0
    real(4) :: tmp
    t_0 = cos((6.28318530718e0 * u2))
    if (t_0 <= 0.9999399781227112e0) then
        tmp = sqrt(u1) * t_0
    else
        tmp = sqrt((u1 / (1.0e0 - u1)))
    end if
    code = tmp
end function
function code(cosTheta_i, u1, u2)
	t_0 = cos(Float32(Float32(6.28318530718) * u2))
	tmp = Float32(0.0)
	if (t_0 <= Float32(0.9999399781227112))
		tmp = Float32(sqrt(u1) * t_0);
	else
		tmp = sqrt(Float32(u1 / Float32(Float32(1.0) - u1)));
	end
	return tmp
end
function tmp_2 = code(cosTheta_i, u1, u2)
	t_0 = cos((single(6.28318530718) * u2));
	tmp = single(0.0);
	if (t_0 <= single(0.9999399781227112))
		tmp = sqrt(u1) * t_0;
	else
		tmp = sqrt((u1 / (single(1.0) - u1)));
	end
	tmp_2 = tmp;
end
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \cos \left(6.28318530718 \cdot u2\right)\\
\mathbf{if}\;t\_0 \leq 0.9999399781227112:\\
\;\;\;\;\sqrt{u1} \cdot t\_0\\

\mathbf{else}:\\
\;\;\;\;\sqrt{\frac{u1}{1 - u1}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (cos.f32 (*.f32 #s(literal 314159265359/50000000000 binary32) u2)) < 0.999939978

    1. Initial program 97.0%

      \[\sqrt{\frac{u1}{1 - u1}} \cdot \cos \left(6.28318530718 \cdot u2\right) \]
    2. Add Preprocessing
    3. Taylor expanded in u1 around 0

      \[\leadsto \color{blue}{\sqrt{u1} \cdot \cos \left(\frac{314159265359}{50000000000} \cdot u2\right)} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \color{blue}{\cos \left(\frac{314159265359}{50000000000} \cdot u2\right) \cdot \sqrt{u1}} \]
      2. lower-*.f32N/A

        \[\leadsto \color{blue}{\cos \left(\frac{314159265359}{50000000000} \cdot u2\right) \cdot \sqrt{u1}} \]
      3. lower-cos.f32N/A

        \[\leadsto \color{blue}{\cos \left(\frac{314159265359}{50000000000} \cdot u2\right)} \cdot \sqrt{u1} \]
      4. lower-*.f32N/A

        \[\leadsto \cos \color{blue}{\left(\frac{314159265359}{50000000000} \cdot u2\right)} \cdot \sqrt{u1} \]
      5. lower-sqrt.f3274.1

        \[\leadsto \cos \left(6.28318530718 \cdot u2\right) \cdot \color{blue}{\sqrt{u1}} \]
    5. Applied rewrites74.1%

      \[\leadsto \color{blue}{\cos \left(6.28318530718 \cdot u2\right) \cdot \sqrt{u1}} \]

    if 0.999939978 < (cos.f32 (*.f32 #s(literal 314159265359/50000000000 binary32) u2))

    1. Initial program 99.4%

      \[\sqrt{\frac{u1}{1 - u1}} \cdot \cos \left(6.28318530718 \cdot u2\right) \]
    2. Add Preprocessing
    3. Taylor expanded in u2 around 0

      \[\leadsto \color{blue}{\sqrt{\frac{u1}{1 - u1}}} \]
    4. Step-by-step derivation
      1. lower-sqrt.f32N/A

        \[\leadsto \color{blue}{\sqrt{\frac{u1}{1 - u1}}} \]
      2. lower-/.f32N/A

        \[\leadsto \sqrt{\color{blue}{\frac{u1}{1 - u1}}} \]
      3. lower--.f3296.0

        \[\leadsto \sqrt{\frac{u1}{\color{blue}{1 - u1}}} \]
    5. Applied rewrites96.0%

      \[\leadsto \color{blue}{\sqrt{\frac{u1}{1 - u1}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification89.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\cos \left(6.28318530718 \cdot u2\right) \leq 0.9999399781227112:\\ \;\;\;\;\sqrt{u1} \cdot \cos \left(6.28318530718 \cdot u2\right)\\ \mathbf{else}:\\ \;\;\;\;\sqrt{\frac{u1}{1 - u1}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 94.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;6.28318530718 \cdot u2 \leq 0.001500000013038516:\\ \;\;\;\;\sqrt{\frac{u1}{1 - u1}}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{\left(u1 - -1\right) \cdot u1} \cdot \cos \left(6.28318530718 \cdot u2\right)\\ \end{array} \end{array} \]
(FPCore (cosTheta_i u1 u2)
 :precision binary32
 (if (<= (* 6.28318530718 u2) 0.001500000013038516)
   (sqrt (/ u1 (- 1.0 u1)))
   (* (sqrt (* (- u1 -1.0) u1)) (cos (* 6.28318530718 u2)))))
float code(float cosTheta_i, float u1, float u2) {
	float tmp;
	if ((6.28318530718f * u2) <= 0.001500000013038516f) {
		tmp = sqrtf((u1 / (1.0f - u1)));
	} else {
		tmp = sqrtf(((u1 - -1.0f) * u1)) * cosf((6.28318530718f * u2));
	}
	return tmp;
}
real(4) function code(costheta_i, u1, u2)
    real(4), intent (in) :: costheta_i
    real(4), intent (in) :: u1
    real(4), intent (in) :: u2
    real(4) :: tmp
    if ((6.28318530718e0 * u2) <= 0.001500000013038516e0) then
        tmp = sqrt((u1 / (1.0e0 - u1)))
    else
        tmp = sqrt(((u1 - (-1.0e0)) * u1)) * cos((6.28318530718e0 * u2))
    end if
    code = tmp
end function
function code(cosTheta_i, u1, u2)
	tmp = Float32(0.0)
	if (Float32(Float32(6.28318530718) * u2) <= Float32(0.001500000013038516))
		tmp = sqrt(Float32(u1 / Float32(Float32(1.0) - u1)));
	else
		tmp = Float32(sqrt(Float32(Float32(u1 - Float32(-1.0)) * u1)) * cos(Float32(Float32(6.28318530718) * u2)));
	end
	return tmp
end
function tmp_2 = code(cosTheta_i, u1, u2)
	tmp = single(0.0);
	if ((single(6.28318530718) * u2) <= single(0.001500000013038516))
		tmp = sqrt((u1 / (single(1.0) - u1)));
	else
		tmp = sqrt(((u1 - single(-1.0)) * u1)) * cos((single(6.28318530718) * u2));
	end
	tmp_2 = tmp;
end
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;6.28318530718 \cdot u2 \leq 0.001500000013038516:\\
\;\;\;\;\sqrt{\frac{u1}{1 - u1}}\\

\mathbf{else}:\\
\;\;\;\;\sqrt{\left(u1 - -1\right) \cdot u1} \cdot \cos \left(6.28318530718 \cdot u2\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (*.f32 #s(literal 314159265359/50000000000 binary32) u2) < 0.00150000001

    1. Initial program 99.5%

      \[\sqrt{\frac{u1}{1 - u1}} \cdot \cos \left(6.28318530718 \cdot u2\right) \]
    2. Add Preprocessing
    3. Taylor expanded in u2 around 0

      \[\leadsto \color{blue}{\sqrt{\frac{u1}{1 - u1}}} \]
    4. Step-by-step derivation
      1. lower-sqrt.f32N/A

        \[\leadsto \color{blue}{\sqrt{\frac{u1}{1 - u1}}} \]
      2. lower-/.f32N/A

        \[\leadsto \sqrt{\color{blue}{\frac{u1}{1 - u1}}} \]
      3. lower--.f3298.6

        \[\leadsto \sqrt{\frac{u1}{\color{blue}{1 - u1}}} \]
    5. Applied rewrites98.6%

      \[\leadsto \color{blue}{\sqrt{\frac{u1}{1 - u1}}} \]

    if 0.00150000001 < (*.f32 #s(literal 314159265359/50000000000 binary32) u2)

    1. Initial program 97.5%

      \[\sqrt{\frac{u1}{1 - u1}} \cdot \cos \left(6.28318530718 \cdot u2\right) \]
    2. Add Preprocessing
    3. Taylor expanded in u1 around 0

      \[\leadsto \sqrt{\color{blue}{u1 \cdot \left(1 + u1\right)}} \cdot \cos \left(\frac{314159265359}{50000000000} \cdot u2\right) \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \sqrt{\color{blue}{\left(1 + u1\right) \cdot u1}} \cdot \cos \left(\frac{314159265359}{50000000000} \cdot u2\right) \]
      2. lower-*.f32N/A

        \[\leadsto \sqrt{\color{blue}{\left(1 + u1\right) \cdot u1}} \cdot \cos \left(\frac{314159265359}{50000000000} \cdot u2\right) \]
      3. lower-+.f3285.0

        \[\leadsto \sqrt{\color{blue}{\left(1 + u1\right)} \cdot u1} \cdot \cos \left(6.28318530718 \cdot u2\right) \]
    5. Applied rewrites85.0%

      \[\leadsto \sqrt{\color{blue}{\left(1 + u1\right) \cdot u1}} \cdot \cos \left(6.28318530718 \cdot u2\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification93.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;6.28318530718 \cdot u2 \leq 0.001500000013038516:\\ \;\;\;\;\sqrt{\frac{u1}{1 - u1}}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{\left(u1 - -1\right) \cdot u1} \cdot \cos \left(6.28318530718 \cdot u2\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 99.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \cos \left(6.28318530718 \cdot u2\right) \cdot \sqrt{\frac{u1}{1 - u1}} \end{array} \]
(FPCore (cosTheta_i u1 u2)
 :precision binary32
 (* (cos (* 6.28318530718 u2)) (sqrt (/ u1 (- 1.0 u1)))))
float code(float cosTheta_i, float u1, float u2) {
	return cosf((6.28318530718f * u2)) * sqrtf((u1 / (1.0f - 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 = cos((6.28318530718e0 * u2)) * sqrt((u1 / (1.0e0 - u1)))
end function
function code(cosTheta_i, u1, u2)
	return Float32(cos(Float32(Float32(6.28318530718) * u2)) * sqrt(Float32(u1 / Float32(Float32(1.0) - u1))))
end
function tmp = code(cosTheta_i, u1, u2)
	tmp = cos((single(6.28318530718) * u2)) * sqrt((u1 / (single(1.0) - u1)));
end
\begin{array}{l}

\\
\cos \left(6.28318530718 \cdot u2\right) \cdot \sqrt{\frac{u1}{1 - u1}}
\end{array}
Derivation
  1. Initial program 98.7%

    \[\sqrt{\frac{u1}{1 - u1}} \cdot \cos \left(6.28318530718 \cdot u2\right) \]
  2. Add Preprocessing
  3. Final simplification98.7%

    \[\leadsto \cos \left(6.28318530718 \cdot u2\right) \cdot \sqrt{\frac{u1}{1 - u1}} \]
  4. Add Preprocessing

Alternative 5: 80.4% accurate, 5.4× speedup?

\[\begin{array}{l} \\ \sqrt{\frac{u1}{1 - u1}} \end{array} \]
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (/ u1 (- 1.0 u1))))
float code(float cosTheta_i, float u1, float u2) {
	return sqrtf((u1 / (1.0f - 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 = sqrt((u1 / (1.0e0 - u1)))
end function
function code(cosTheta_i, u1, u2)
	return sqrt(Float32(u1 / Float32(Float32(1.0) - u1)))
end
function tmp = code(cosTheta_i, u1, u2)
	tmp = sqrt((u1 / (single(1.0) - u1)));
end
\begin{array}{l}

\\
\sqrt{\frac{u1}{1 - u1}}
\end{array}
Derivation
  1. Initial program 98.7%

    \[\sqrt{\frac{u1}{1 - u1}} \cdot \cos \left(6.28318530718 \cdot u2\right) \]
  2. Add Preprocessing
  3. Taylor expanded in u2 around 0

    \[\leadsto \color{blue}{\sqrt{\frac{u1}{1 - u1}}} \]
  4. Step-by-step derivation
    1. lower-sqrt.f32N/A

      \[\leadsto \color{blue}{\sqrt{\frac{u1}{1 - u1}}} \]
    2. lower-/.f32N/A

      \[\leadsto \sqrt{\color{blue}{\frac{u1}{1 - u1}}} \]
    3. lower--.f3278.0

      \[\leadsto \sqrt{\frac{u1}{\color{blue}{1 - u1}}} \]
  5. Applied rewrites78.0%

    \[\leadsto \color{blue}{\sqrt{\frac{u1}{1 - u1}}} \]
  6. Add Preprocessing

Alternative 6: 71.8% accurate, 7.1× speedup?

\[\begin{array}{l} \\ \sqrt{\left(u1 - -1\right) \cdot u1} \end{array} \]
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (* (- u1 -1.0) u1)))
float code(float cosTheta_i, float u1, float u2) {
	return sqrtf(((u1 - -1.0f) * 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 = sqrt(((u1 - (-1.0e0)) * u1))
end function
function code(cosTheta_i, u1, u2)
	return sqrt(Float32(Float32(u1 - Float32(-1.0)) * u1))
end
function tmp = code(cosTheta_i, u1, u2)
	tmp = sqrt(((u1 - single(-1.0)) * u1));
end
\begin{array}{l}

\\
\sqrt{\left(u1 - -1\right) \cdot u1}
\end{array}
Derivation
  1. Initial program 98.7%

    \[\sqrt{\frac{u1}{1 - u1}} \cdot \cos \left(6.28318530718 \cdot u2\right) \]
  2. Add Preprocessing
  3. Taylor expanded in u2 around 0

    \[\leadsto \color{blue}{\sqrt{\frac{u1}{1 - u1}}} \]
  4. Step-by-step derivation
    1. lower-sqrt.f32N/A

      \[\leadsto \color{blue}{\sqrt{\frac{u1}{1 - u1}}} \]
    2. lower-/.f32N/A

      \[\leadsto \sqrt{\color{blue}{\frac{u1}{1 - u1}}} \]
    3. lower--.f3278.0

      \[\leadsto \sqrt{\frac{u1}{\color{blue}{1 - u1}}} \]
  5. Applied rewrites78.0%

    \[\leadsto \color{blue}{\sqrt{\frac{u1}{1 - u1}}} \]
  6. Taylor expanded in u1 around inf

    \[\leadsto \sqrt{\frac{u1}{u1 \cdot \left(\frac{1}{u1} - 1\right)}} \]
  7. Step-by-step derivation
    1. Applied rewrites77.9%

      \[\leadsto \sqrt{\frac{u1}{\left(\frac{1}{u1} - 1\right) \cdot u1}} \]
    2. Taylor expanded in u1 around 0

      \[\leadsto \sqrt{u1 \cdot \left(1 + u1\right)} \]
    3. Step-by-step derivation
      1. Applied rewrites71.1%

        \[\leadsto \sqrt{\left(1 + u1\right) \cdot u1} \]
      2. Final simplification71.1%

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

      Alternative 7: 63.8% accurate, 12.3× speedup?

      \[\begin{array}{l} \\ \sqrt{u1} \end{array} \]
      (FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt u1))
      float code(float cosTheta_i, float u1, float u2) {
      	return sqrtf(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 = sqrt(u1)
      end function
      
      function code(cosTheta_i, u1, u2)
      	return sqrt(u1)
      end
      
      function tmp = code(cosTheta_i, u1, u2)
      	tmp = sqrt(u1);
      end
      
      \begin{array}{l}
      
      \\
      \sqrt{u1}
      \end{array}
      
      Derivation
      1. Initial program 98.7%

        \[\sqrt{\frac{u1}{1 - u1}} \cdot \cos \left(6.28318530718 \cdot u2\right) \]
      2. Add Preprocessing
      3. Taylor expanded in u2 around 0

        \[\leadsto \color{blue}{\sqrt{\frac{u1}{1 - u1}}} \]
      4. Step-by-step derivation
        1. lower-sqrt.f32N/A

          \[\leadsto \color{blue}{\sqrt{\frac{u1}{1 - u1}}} \]
        2. lower-/.f32N/A

          \[\leadsto \sqrt{\color{blue}{\frac{u1}{1 - u1}}} \]
        3. lower--.f3278.0

          \[\leadsto \sqrt{\frac{u1}{\color{blue}{1 - u1}}} \]
      5. Applied rewrites78.0%

        \[\leadsto \color{blue}{\sqrt{\frac{u1}{1 - u1}}} \]
      6. Taylor expanded in u1 around 0

        \[\leadsto \sqrt{u1} \]
      7. Step-by-step derivation
        1. Applied rewrites63.2%

          \[\leadsto \sqrt{u1} \]
        2. Add Preprocessing

        Reproduce

        ?
        herbie shell --seed 2024312 
        (FPCore (cosTheta_i u1 u2)
          :name "Trowbridge-Reitz 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 (/ u1 (- 1.0 u1))) (cos (* 6.28318530718 u2))))