
(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 18 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 (* (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}
Initial program 98.3%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(if (<= (* 6.28318530718 u2) 1.0)
(*
(sqrt (* (/ u1 (- 1.0 (* u1 u1))) (+ u1 1.0)))
(*
u2
(fma
(* u2 u2)
(fma
(* u2 u2)
(fma (* u2 u2) -76.70585975309672 81.6052492761019)
-41.341702240407926)
6.28318530718)))
(* (sin (* 6.28318530718 u2)) (sqrt (fma u1 (fma u1 u1 u1) u1)))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if ((6.28318530718f * u2) <= 1.0f) {
tmp = sqrtf(((u1 / (1.0f - (u1 * u1))) * (u1 + 1.0f))) * (u2 * fmaf((u2 * u2), fmaf((u2 * u2), fmaf((u2 * u2), -76.70585975309672f, 81.6052492761019f), -41.341702240407926f), 6.28318530718f));
} else {
tmp = sinf((6.28318530718f * u2)) * sqrtf(fmaf(u1, fmaf(u1, u1, u1), u1));
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (Float32(Float32(6.28318530718) * u2) <= Float32(1.0)) tmp = Float32(sqrt(Float32(Float32(u1 / Float32(Float32(1.0) - Float32(u1 * u1))) * Float32(u1 + Float32(1.0)))) * Float32(u2 * fma(Float32(u2 * u2), fma(Float32(u2 * u2), fma(Float32(u2 * u2), Float32(-76.70585975309672), Float32(81.6052492761019)), Float32(-41.341702240407926)), Float32(6.28318530718)))); else tmp = Float32(sin(Float32(Float32(6.28318530718) * u2)) * sqrt(fma(u1, fma(u1, u1, u1), u1))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;6.28318530718 \cdot u2 \leq 1:\\
\;\;\;\;\sqrt{\frac{u1}{1 - u1 \cdot u1} \cdot \left(u1 + 1\right)} \cdot \left(u2 \cdot \mathsf{fma}\left(u2 \cdot u2, \mathsf{fma}\left(u2 \cdot u2, \mathsf{fma}\left(u2 \cdot u2, -76.70585975309672, 81.6052492761019\right), -41.341702240407926\right), 6.28318530718\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sin \left(6.28318530718 \cdot u2\right) \cdot \sqrt{\mathsf{fma}\left(u1, \mathsf{fma}\left(u1, u1, u1\right), u1\right)}\\
\end{array}
\end{array}
if (*.f32 #s(literal 314159265359/50000000000 binary32) u2) < 1Initial program 98.5%
Taylor expanded in u2 around 0
lower-*.f32N/A
+-commutativeN/A
unpow2N/A
associate-*l*N/A
*-commutativeN/A
lower-fma.f32N/A
*-commutativeN/A
lower-*.f32N/A
sub-negN/A
unpow2N/A
associate-*r*N/A
*-commutativeN/A
metadata-evalN/A
lower-fma.f32N/A
*-commutativeN/A
lower-*.f3297.4
Applied rewrites97.4%
Taylor expanded in u2 around 0
lower-*.f32N/A
+-commutativeN/A
lower-fma.f32N/A
unpow2N/A
lower-*.f32N/A
sub-negN/A
metadata-evalN/A
lower-fma.f32N/A
unpow2N/A
lower-*.f32N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f32N/A
unpow2N/A
lower-*.f3298.4
Applied rewrites98.4%
lift-/.f32N/A
lift--.f32N/A
flip--N/A
associate-/r/N/A
lower-*.f32N/A
lower-/.f32N/A
metadata-evalN/A
lift-*.f32N/A
lower--.f32N/A
lower-+.f3298.3
Applied rewrites98.3%
if 1 < (*.f32 #s(literal 314159265359/50000000000 binary32) u2) Initial program 96.4%
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.f3288.1
Applied rewrites88.1%
Final simplification97.5%
herbie shell --seed 2024228
(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))))