
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log (- 1.0 u1)))) (sin (* (* 2.0 PI) u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-logf((1.0f - u1))) * sinf(((2.0f * ((float) M_PI)) * u2));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log(Float32(Float32(1.0) - u1)))) * sin(Float32(Float32(Float32(2.0) * Float32(pi)) * u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-log((single(1.0) - u1))) * sin(((single(2.0) * single(pi)) * u2)); end
\begin{array}{l}
\\
\sqrt{-\log \left(1 - u1\right)} \cdot \sin \left(\left(2 \cdot \pi\right) \cdot u2\right)
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 9 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log (- 1.0 u1)))) (sin (* (* 2.0 PI) u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-logf((1.0f - u1))) * sinf(((2.0f * ((float) M_PI)) * u2));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log(Float32(Float32(1.0) - u1)))) * sin(Float32(Float32(Float32(2.0) * Float32(pi)) * u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-log((single(1.0) - u1))) * sin(((single(2.0) * single(pi)) * u2)); end
\begin{array}{l}
\\
\sqrt{-\log \left(1 - u1\right)} \cdot \sin \left(\left(2 \cdot \pi\right) \cdot u2\right)
\end{array}
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) (sin (* 2.0 (* PI u2)))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * sinf((2.0f * (((float) M_PI) * u2)));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * sin(Float32(Float32(2.0) * Float32(Float32(pi) * u2)))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(2 \cdot \left(\pi \cdot u2\right)\right)
\end{array}
Initial program 57.0%
sub-neg57.0%
log1p-def98.5%
associate-*l*98.5%
Simplified98.5%
Final simplification98.5%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* 2.0 PI))))
(if (<= t_0 0.0013000000035390258)
(* (sqrt (- (log1p (- u1)))) (* PI (+ u2 u2)))
(* (sqrt (- u1 (* u1 (* u1 -0.5)))) (sin t_0)))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = u2 * (2.0f * ((float) M_PI));
float tmp;
if (t_0 <= 0.0013000000035390258f) {
tmp = sqrtf(-log1pf(-u1)) * (((float) M_PI) * (u2 + u2));
} else {
tmp = sqrtf((u1 - (u1 * (u1 * -0.5f)))) * sinf(t_0);
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = Float32(u2 * Float32(Float32(2.0) * Float32(pi))) tmp = Float32(0.0) if (t_0 <= Float32(0.0013000000035390258)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(pi) * Float32(u2 + u2))); else tmp = Float32(sqrt(Float32(u1 - Float32(u1 * Float32(u1 * Float32(-0.5))))) * sin(t_0)); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := u2 \cdot \left(2 \cdot \pi\right)\\
\mathbf{if}\;t_0 \leq 0.0013000000035390258:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(\pi \cdot \left(u2 + u2\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1 - u1 \cdot \left(u1 \cdot -0.5\right)} \cdot \sin t_0\\
\end{array}
\end{array}
if (*.f32 (*.f32 2 (PI.f32)) u2) < 0.0013Initial program 58.3%
sub-neg58.3%
log1p-def98.7%
associate-*l*98.7%
Simplified98.7%
add-sqr-sqrt98.1%
pow298.1%
Applied egg-rr98.1%
unpow298.1%
add-sqr-sqrt98.7%
add-sqr-sqrt97.8%
associate-*r*97.8%
Applied egg-rr97.8%
Taylor expanded in u2 around 0 98.4%
*-commutative98.4%
count-298.4%
distribute-lft-out98.4%
Simplified98.4%
if 0.0013 < (*.f32 (*.f32 2 (PI.f32)) u2) Initial program 55.2%
Taylor expanded in u1 around 0 90.0%
+-commutative90.0%
mul-1-neg90.0%
unsub-neg90.0%
*-commutative90.0%
unpow290.0%
associate-*l*90.0%
Simplified90.0%
Final simplification94.8%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= (* u2 (* 2.0 PI)) 0.004600000102072954) (* (sqrt (- (log1p (- u1)))) (* PI (+ u2 u2))) (* (sqrt u1) (sin (* 2.0 (* PI u2))))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if ((u2 * (2.0f * ((float) M_PI))) <= 0.004600000102072954f) {
tmp = sqrtf(-log1pf(-u1)) * (((float) M_PI) * (u2 + u2));
} else {
tmp = sqrtf(u1) * sinf((2.0f * (((float) M_PI) * u2)));
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (Float32(u2 * Float32(Float32(2.0) * Float32(pi))) <= Float32(0.004600000102072954)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(pi) * Float32(u2 + u2))); else tmp = Float32(sqrt(u1) * sin(Float32(Float32(2.0) * Float32(Float32(pi) * u2)))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u2 \cdot \left(2 \cdot \pi\right) \leq 0.004600000102072954:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(\pi \cdot \left(u2 + u2\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1} \cdot \sin \left(2 \cdot \left(\pi \cdot u2\right)\right)\\
\end{array}
\end{array}
if (*.f32 (*.f32 2 (PI.f32)) u2) < 0.0046000001Initial program 57.5%
sub-neg57.5%
log1p-def98.6%
associate-*l*98.6%
Simplified98.6%
add-sqr-sqrt98.0%
pow298.0%
Applied egg-rr98.0%
unpow298.0%
add-sqr-sqrt98.6%
add-sqr-sqrt97.8%
associate-*r*97.9%
Applied egg-rr97.9%
Taylor expanded in u2 around 0 97.0%
*-commutative97.0%
count-297.0%
distribute-lft-out97.0%
Simplified97.0%
if 0.0046000001 < (*.f32 (*.f32 2 (PI.f32)) u2) Initial program 55.9%
Taylor expanded in u1 around 0 78.5%
mul-1-neg78.5%
Simplified78.5%
Taylor expanded in u2 around inf 78.5%
Final simplification90.8%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt u1) (sin (* 2.0 (* PI u2)))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(u1) * sinf((2.0f * (((float) M_PI) * u2)));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(u1) * sin(Float32(Float32(2.0) * Float32(Float32(pi) * u2)))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(u1) * sin((single(2.0) * (single(pi) * u2))); end
\begin{array}{l}
\\
\sqrt{u1} \cdot \sin \left(2 \cdot \left(\pi \cdot u2\right)\right)
\end{array}
Initial program 57.0%
Taylor expanded in u1 around 0 77.3%
mul-1-neg77.3%
Simplified77.3%
Taylor expanded in u2 around inf 77.3%
Final simplification77.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* 2.0 (* PI (sqrt (* u2 (* u1 u2))))))
float code(float cosTheta_i, float u1, float u2) {
return 2.0f * (((float) M_PI) * sqrtf((u2 * (u1 * u2))));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(2.0) * Float32(Float32(pi) * sqrt(Float32(u2 * Float32(u1 * u2))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(2.0) * (single(pi) * sqrt((u2 * (u1 * u2)))); end
\begin{array}{l}
\\
2 \cdot \left(\pi \cdot \sqrt{u2 \cdot \left(u1 \cdot u2\right)}\right)
\end{array}
Initial program 57.0%
Taylor expanded in u1 around 0 77.3%
mul-1-neg77.3%
Simplified77.3%
Taylor expanded in u2 around 0 66.3%
associate-*r*66.3%
*-commutative66.3%
*-commutative66.3%
Simplified66.3%
add-sqr-sqrt66.2%
sqrt-unprod66.3%
*-commutative66.3%
*-commutative66.3%
swap-sqr66.2%
add-sqr-sqrt66.3%
Applied egg-rr66.3%
associate-*r*66.3%
*-commutative66.3%
*-commutative66.3%
Simplified66.3%
Final simplification66.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* 2.0 (* u2 (* PI (sqrt u1)))))
float code(float cosTheta_i, float u1, float u2) {
return 2.0f * (u2 * (((float) M_PI) * sqrtf(u1)));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(2.0) * Float32(u2 * Float32(Float32(pi) * sqrt(u1)))) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(2.0) * (u2 * (single(pi) * sqrt(u1))); end
\begin{array}{l}
\\
2 \cdot \left(u2 \cdot \left(\pi \cdot \sqrt{u1}\right)\right)
\end{array}
Initial program 57.0%
Taylor expanded in u1 around 0 77.3%
mul-1-neg77.3%
Simplified77.3%
Taylor expanded in u2 around 0 66.3%
associate-*r*66.3%
*-commutative66.3%
*-commutative66.3%
Simplified66.3%
Taylor expanded in u2 around 0 66.3%
*-commutative66.3%
associate-*r*66.3%
*-commutative66.3%
*-commutative66.3%
Simplified66.3%
Final simplification66.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* 2.0 (* PI (* u2 (sqrt u1)))))
float code(float cosTheta_i, float u1, float u2) {
return 2.0f * (((float) M_PI) * (u2 * sqrtf(u1)));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(2.0) * Float32(Float32(pi) * Float32(u2 * sqrt(u1)))) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(2.0) * (single(pi) * (u2 * sqrt(u1))); end
\begin{array}{l}
\\
2 \cdot \left(\pi \cdot \left(u2 \cdot \sqrt{u1}\right)\right)
\end{array}
Initial program 57.0%
Taylor expanded in u1 around 0 77.3%
mul-1-neg77.3%
Simplified77.3%
Taylor expanded in u2 around 0 66.3%
associate-*r*66.3%
*-commutative66.3%
*-commutative66.3%
Simplified66.3%
Final simplification66.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* 2.0 (* (sqrt u1) (* PI u2))))
float code(float cosTheta_i, float u1, float u2) {
return 2.0f * (sqrtf(u1) * (((float) M_PI) * u2));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(2.0) * Float32(sqrt(u1) * Float32(Float32(pi) * u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(2.0) * (sqrt(u1) * (single(pi) * u2)); end
\begin{array}{l}
\\
2 \cdot \left(\sqrt{u1} \cdot \left(\pi \cdot u2\right)\right)
\end{array}
Initial program 57.0%
Taylor expanded in u1 around 0 77.3%
mul-1-neg77.3%
Simplified77.3%
Taylor expanded in u2 around 0 66.3%
Final simplification66.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (* u1 0.0)))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((u1 * 0.0f));
}
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 * 0.0e0))
end function
function code(cosTheta_i, u1, u2) return sqrt(Float32(u1 * Float32(0.0))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt((u1 * single(0.0))); end
\begin{array}{l}
\\
\sqrt{u1 \cdot 0}
\end{array}
Initial program 57.0%
Taylor expanded in u1 around 0 77.3%
mul-1-neg77.3%
Simplified77.3%
add-sqr-sqrt74.5%
sqrt-unprod74.9%
associate-*r*74.9%
associate-*r*74.9%
swap-sqr74.9%
add-sqr-sqrt74.9%
remove-double-neg74.9%
pow274.9%
Applied egg-rr74.9%
unpow274.9%
sqr-sin-a35.9%
*-commutative35.9%
associate-*r*35.9%
*-commutative35.9%
sqr-sin-a74.9%
sin-mult35.9%
Applied egg-rr35.9%
div-sub35.9%
+-inverses35.9%
cos-035.9%
metadata-eval35.9%
distribute-lft-out35.9%
distribute-lft-out35.9%
metadata-eval35.9%
Simplified35.9%
Taylor expanded in u2 around 0 7.1%
Final simplification7.1%
herbie shell --seed 2023293
(FPCore (cosTheta_i u1 u2)
:name "Beckmann 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 (- (log (- 1.0 u1)))) (sin (* (* 2.0 PI) u2))))