
(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:
Herbie found 14 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(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}
(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}
Initial program 99.0%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (sqrt (/ u1 (- 1.0 u1)))) (t_1 (cos (* 6.28318530718 u2))))
(if (<= (* t_0 t_1) 0.08500000089406967)
(* t_1 (sqrt (fma u1 (fma u1 u1 u1) u1)))
(fma
(* t_0 (* u2 u2))
(fma
(* u2 u2)
(fma (* u2 u2) -85.45681720672748 64.93939402268539)
-19.739208802181317)
t_0))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = sqrtf((u1 / (1.0f - u1)));
float t_1 = cosf((6.28318530718f * u2));
float tmp;
if ((t_0 * t_1) <= 0.08500000089406967f) {
tmp = t_1 * sqrtf(fmaf(u1, fmaf(u1, u1, u1), u1));
} else {
tmp = fmaf((t_0 * (u2 * u2)), fmaf((u2 * u2), fmaf((u2 * u2), -85.45681720672748f, 64.93939402268539f), -19.739208802181317f), t_0);
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = sqrt(Float32(u1 / Float32(Float32(1.0) - u1))) t_1 = cos(Float32(Float32(6.28318530718) * u2)) tmp = Float32(0.0) if (Float32(t_0 * t_1) <= Float32(0.08500000089406967)) tmp = Float32(t_1 * sqrt(fma(u1, fma(u1, u1, u1), u1))); else tmp = fma(Float32(t_0 * Float32(u2 * u2)), fma(Float32(u2 * u2), fma(Float32(u2 * u2), Float32(-85.45681720672748), Float32(64.93939402268539)), Float32(-19.739208802181317)), t_0); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{\frac{u1}{1 - u1}}\\
t_1 := \cos \left(6.28318530718 \cdot u2\right)\\
\mathbf{if}\;t\_0 \cdot t\_1 \leq 0.08500000089406967:\\
\;\;\;\;t\_1 \cdot \sqrt{\mathsf{fma}\left(u1, \mathsf{fma}\left(u1, u1, u1\right), u1\right)}\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(t\_0 \cdot \left(u2 \cdot u2\right), \mathsf{fma}\left(u2 \cdot u2, \mathsf{fma}\left(u2 \cdot u2, -85.45681720672748, 64.93939402268539\right), -19.739208802181317\right), t\_0\right)\\
\end{array}
\end{array}
if (*.f32 (sqrt.f32 (/.f32 u1 (-.f32 #s(literal 1 binary32) u1))) (cos.f32 (*.f32 #s(literal 314159265359/50000000000 binary32) u2))) < 0.0850000009Initial program 99.0%
Taylor expanded in u1 around 0
+-commutativeN/A
distribute-lft-inN/A
*-rgt-identityN/A
lower-fma.f32N/A
+-commutativeN/A
distribute-lft-inN/A
*-rgt-identityN/A
lower-fma.f3298.5
Applied rewrites98.5%
if 0.0850000009 < (*.f32 (sqrt.f32 (/.f32 u1 (-.f32 #s(literal 1 binary32) u1))) (cos.f32 (*.f32 #s(literal 314159265359/50000000000 binary32) u2))) Initial program 99.2%
Taylor expanded in u2 around 0
Applied rewrites97.2%
Final simplification98.2%
herbie shell --seed 2024223
(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))))