
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (/ u1 (- 1.0 u1))) (sin (* 6.28318530718 u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((u1 / (1.0f - u1))) * sinf((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))) * sin((6.28318530718e0 * u2))
end function
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(u1 / Float32(Float32(1.0) - u1))) * sin(Float32(Float32(6.28318530718) * u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt((u1 / (single(1.0) - u1))) * sin((single(6.28318530718) * u2)); end
\begin{array}{l}
\\
\sqrt{\frac{u1}{1 - u1}} \cdot \sin \left(6.28318530718 \cdot u2\right)
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 17 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (/ u1 (- 1.0 u1))) (sin (* 6.28318530718 u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((u1 / (1.0f - u1))) * sinf((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))) * sin((6.28318530718e0 * u2))
end function
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(u1 / Float32(Float32(1.0) - u1))) * sin(Float32(Float32(6.28318530718) * u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt((u1 / (single(1.0) - u1))) * sin((single(6.28318530718) * u2)); end
\begin{array}{l}
\\
\sqrt{\frac{u1}{1 - u1}} \cdot \sin \left(6.28318530718 \cdot u2\right)
\end{array}
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* u2 6.28318530718)) (sqrt (/ u1 (- 1.0 u1)))))
float code(float cosTheta_i, float u1, float u2) {
return sinf((u2 * 6.28318530718f)) * 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 = sin((u2 * 6.28318530718e0)) * sqrt((u1 / (1.0e0 - u1)))
end function
function code(cosTheta_i, u1, u2) return Float32(sin(Float32(u2 * Float32(6.28318530718))) * sqrt(Float32(u1 / Float32(Float32(1.0) - u1)))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sin((u2 * single(6.28318530718))) * sqrt((u1 / (single(1.0) - u1))); end
\begin{array}{l}
\\
\sin \left(u2 \cdot 6.28318530718\right) \cdot \sqrt{\frac{u1}{1 - u1}}
\end{array}
Initial program 98.4%
Final simplification98.4%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (sqrt (/ u1 (- 1.0 u1)))))
(if (<= (* u2 6.28318530718) 0.6499999761581421)
(*
(fma
t_0
(fma (* -41.341702240407926 u2) u2 6.28318530718)
(*
(* (fma (* -76.70585975309672 u2) u2 81.6052492761019) t_0)
(* (* u2 u2) (* u2 u2))))
u2)
(* (sqrt (fma (fma u1 u1 u1) u1 u1)) (sin (* u2 6.28318530718))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = sqrtf((u1 / (1.0f - u1)));
float tmp;
if ((u2 * 6.28318530718f) <= 0.6499999761581421f) {
tmp = fmaf(t_0, fmaf((-41.341702240407926f * u2), u2, 6.28318530718f), ((fmaf((-76.70585975309672f * u2), u2, 81.6052492761019f) * t_0) * ((u2 * u2) * (u2 * u2)))) * u2;
} else {
tmp = sqrtf(fmaf(fmaf(u1, u1, u1), u1, u1)) * sinf((u2 * 6.28318530718f));
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = sqrt(Float32(u1 / Float32(Float32(1.0) - u1))) tmp = Float32(0.0) if (Float32(u2 * Float32(6.28318530718)) <= Float32(0.6499999761581421)) tmp = Float32(fma(t_0, fma(Float32(Float32(-41.341702240407926) * u2), u2, Float32(6.28318530718)), Float32(Float32(fma(Float32(Float32(-76.70585975309672) * u2), u2, Float32(81.6052492761019)) * t_0) * Float32(Float32(u2 * u2) * Float32(u2 * u2)))) * u2); else tmp = Float32(sqrt(fma(fma(u1, u1, u1), u1, u1)) * sin(Float32(u2 * Float32(6.28318530718)))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{\frac{u1}{1 - u1}}\\
\mathbf{if}\;u2 \cdot 6.28318530718 \leq 0.6499999761581421:\\
\;\;\;\;\mathsf{fma}\left(t\_0, \mathsf{fma}\left(-41.341702240407926 \cdot u2, u2, 6.28318530718\right), \left(\mathsf{fma}\left(-76.70585975309672 \cdot u2, u2, 81.6052492761019\right) \cdot t\_0\right) \cdot \left(\left(u2 \cdot u2\right) \cdot \left(u2 \cdot u2\right)\right)\right) \cdot u2\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\mathsf{fma}\left(\mathsf{fma}\left(u1, u1, u1\right), u1, u1\right)} \cdot \sin \left(u2 \cdot 6.28318530718\right)\\
\end{array}
\end{array}
if (*.f32 #s(literal 314159265359/50000000000 binary32) u2) < 0.649999976Initial program 98.5%
Taylor expanded in u2 around 0
*-commutativeN/A
lower-*.f3288.4
Applied rewrites88.4%
lift-*.f32N/A
lift-sqrt.f32N/A
lift-/.f32N/A
sqrt-divN/A
lift-sqrt.f32N/A
associate-*l/N/A
lower-/.f32N/A
lower-*.f32N/A
lower-sqrt.f3288.2
Applied rewrites88.2%
Taylor expanded in u2 around 0
Applied rewrites98.5%
if 0.649999976 < (*.f32 #s(literal 314159265359/50000000000 binary32) u2) Initial program 97.0%
Taylor expanded in u1 around 0
*-commutativeN/A
+-commutativeN/A
distribute-lft1-inN/A
lower-fma.f32N/A
+-commutativeN/A
distribute-lft-inN/A
*-rgt-identityN/A
lower-fma.f3288.3
Applied rewrites88.3%
Final simplification97.4%
herbie shell --seed 2024230
(FPCore (cosTheta_i u1 u2)
:name "Trowbridge-Reitz Sample, near normal, slope_y"
: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))) (sin (* 6.28318530718 u2))))