
(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(Float32(2.0) * Float32(pi)) * u2))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(\left(2 \cdot \pi\right) \cdot u2\right)
\end{array}
Initial program 54.7%
sub-neg54.7%
log1p-define98.4%
Simplified98.4%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= u1 0.07999999821186066)
(*
(sin t_0)
(sqrt
(*
u1
(- 1.0 (* u1 (- (* u1 (- (* u1 -0.25) 0.3333333333333333)) 0.5))))))
(* (sqrt (- (log1p (- u1)))) t_0))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = (2.0f * ((float) M_PI)) * u2;
float tmp;
if (u1 <= 0.07999999821186066f) {
tmp = sinf(t_0) * sqrtf((u1 * (1.0f - (u1 * ((u1 * ((u1 * -0.25f) - 0.3333333333333333f)) - 0.5f)))));
} else {
tmp = sqrtf(-log1pf(-u1)) * t_0;
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = Float32(Float32(Float32(2.0) * Float32(pi)) * u2) tmp = Float32(0.0) if (u1 <= Float32(0.07999999821186066)) tmp = Float32(sin(t_0) * sqrt(Float32(u1 * Float32(Float32(1.0) - Float32(u1 * Float32(Float32(u1 * Float32(Float32(u1 * Float32(-0.25)) - Float32(0.3333333333333333))) - Float32(0.5))))))); else tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * t_0); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;u1 \leq 0.07999999821186066:\\
\;\;\;\;\sin t\_0 \cdot \sqrt{u1 \cdot \left(1 - u1 \cdot \left(u1 \cdot \left(u1 \cdot -0.25 - 0.3333333333333333\right) - 0.5\right)\right)}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot t\_0\\
\end{array}
\end{array}
if u1 < 0.0799999982Initial program 50.0%
Taylor expanded in u1 around 0 98.2%
if 0.0799999982 < u1 Initial program 98.6%
sub-neg98.6%
log1p-define98.8%
Simplified98.8%
add-sqr-sqrt98.2%
pow298.2%
associate-*l*98.2%
Applied egg-rr98.2%
sqrt-prod98.1%
unpow-prod-down97.4%
pow297.4%
add-sqr-sqrt98.3%
Applied egg-rr98.3%
Taylor expanded in u2 around 0 90.5%
unpow290.5%
rem-square-sqrt91.0%
Simplified91.0%
Final simplification97.5%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.0003699999942909926)
(* (sqrt (- (log1p (- u1)))) t_0)
(*
(sin t_0)
(sqrt (* u1 (+ 1.0 (* u1 (- 0.5 (* u1 -0.3333333333333333))))))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = (2.0f * ((float) M_PI)) * u2;
float tmp;
if (t_0 <= 0.0003699999942909926f) {
tmp = sqrtf(-log1pf(-u1)) * t_0;
} else {
tmp = sinf(t_0) * sqrtf((u1 * (1.0f + (u1 * (0.5f - (u1 * -0.3333333333333333f))))));
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = Float32(Float32(Float32(2.0) * Float32(pi)) * u2) tmp = Float32(0.0) if (t_0 <= Float32(0.0003699999942909926)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * t_0); else tmp = Float32(sin(t_0) * sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(u1 * Float32(Float32(0.5) - Float32(u1 * Float32(-0.3333333333333333)))))))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.0003699999942909926:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot t\_0\\
\mathbf{else}:\\
\;\;\;\;\sin t\_0 \cdot \sqrt{u1 \cdot \left(1 + u1 \cdot \left(0.5 - u1 \cdot -0.3333333333333333\right)\right)}\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 3.69999994e-4Initial program 56.4%
sub-neg56.4%
log1p-define98.6%
Simplified98.6%
add-sqr-sqrt97.7%
pow297.7%
associate-*l*97.7%
Applied egg-rr97.7%
sqrt-prod97.5%
unpow-prod-down97.5%
pow297.5%
add-sqr-sqrt97.8%
Applied egg-rr97.8%
Taylor expanded in u2 around 0 98.1%
unpow298.1%
rem-square-sqrt98.6%
Simplified98.6%
if 3.69999994e-4 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 52.3%
Taylor expanded in u1 around 0 94.2%
Final simplification96.8%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.0007999999797903001)
(* (sqrt (- (log1p (- u1)))) t_0)
(* (sin t_0) (sqrt (* u1 (- 1.0 (* u1 -0.5))))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = (2.0f * ((float) M_PI)) * u2;
float tmp;
if (t_0 <= 0.0007999999797903001f) {
tmp = sqrtf(-log1pf(-u1)) * t_0;
} else {
tmp = sinf(t_0) * sqrtf((u1 * (1.0f - (u1 * -0.5f))));
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = Float32(Float32(Float32(2.0) * Float32(pi)) * u2) tmp = Float32(0.0) if (t_0 <= Float32(0.0007999999797903001)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * t_0); else tmp = Float32(sin(t_0) * sqrt(Float32(u1 * Float32(Float32(1.0) - Float32(u1 * Float32(-0.5)))))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.0007999999797903001:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot t\_0\\
\mathbf{else}:\\
\;\;\;\;\sin t\_0 \cdot \sqrt{u1 \cdot \left(1 - u1 \cdot -0.5\right)}\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 7.9999998e-4Initial program 55.7%
sub-neg55.7%
log1p-define98.6%
Simplified98.6%
add-sqr-sqrt97.7%
pow297.7%
associate-*l*97.7%
Applied egg-rr97.7%
sqrt-prod97.5%
unpow-prod-down97.6%
pow297.6%
add-sqr-sqrt97.9%
Applied egg-rr97.9%
Taylor expanded in u2 around 0 98.1%
unpow298.1%
rem-square-sqrt98.5%
Simplified98.5%
if 7.9999998e-4 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 53.2%
Taylor expanded in u1 around 0 90.6%
Final simplification95.4%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.014999999664723873)
(* (sqrt (- (log1p (- u1)))) t_0)
(* (sin t_0) (sqrt u1)))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = (2.0f * ((float) M_PI)) * u2;
float tmp;
if (t_0 <= 0.014999999664723873f) {
tmp = sqrtf(-log1pf(-u1)) * t_0;
} else {
tmp = sinf(t_0) * sqrtf(u1);
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = Float32(Float32(Float32(2.0) * Float32(pi)) * u2) tmp = Float32(0.0) if (t_0 <= Float32(0.014999999664723873)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * t_0); else tmp = Float32(sin(t_0) * sqrt(u1)); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.014999999664723873:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot t\_0\\
\mathbf{else}:\\
\;\;\;\;\sin t\_0 \cdot \sqrt{u1}\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 0.0149999997Initial program 54.8%
sub-neg54.8%
log1p-define98.5%
Simplified98.5%
add-sqr-sqrt97.7%
pow297.7%
associate-*l*97.7%
Applied egg-rr97.7%
sqrt-prod97.6%
unpow-prod-down97.6%
pow297.6%
add-sqr-sqrt97.9%
Applied egg-rr97.9%
Taylor expanded in u2 around 0 95.6%
unpow295.6%
rem-square-sqrt95.9%
Simplified95.9%
if 0.0149999997 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 54.4%
sub-neg54.4%
log1p-define98.1%
Simplified98.1%
pow1/298.1%
log1p-undefine54.4%
sub-neg54.4%
pow-to-exp54.4%
add-sqr-sqrt54.4%
sqrt-unprod54.4%
sqr-neg54.4%
sqrt-unprod1.5%
add-sqr-sqrt1.5%
sub-neg1.5%
log1p-undefine-0.0%
add-sqr-sqrt-0.0%
sqrt-unprod76.6%
sqr-neg76.6%
sqrt-unprod76.7%
add-sqr-sqrt76.6%
Applied egg-rr76.6%
Taylor expanded in u1 around 0 80.0%
Final simplification91.8%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* (* 2.0 PI) u2)) (sqrt u1)))
float code(float cosTheta_i, float u1, float u2) {
return sinf(((2.0f * ((float) M_PI)) * u2)) * sqrtf(u1);
}
function code(cosTheta_i, u1, u2) return Float32(sin(Float32(Float32(Float32(2.0) * Float32(pi)) * u2)) * sqrt(u1)) end
function tmp = code(cosTheta_i, u1, u2) tmp = sin(((single(2.0) * single(pi)) * u2)) * sqrt(u1); end
\begin{array}{l}
\\
\sin \left(\left(2 \cdot \pi\right) \cdot u2\right) \cdot \sqrt{u1}
\end{array}
Initial program 54.7%
sub-neg54.7%
log1p-define98.4%
Simplified98.4%
pow1/298.4%
log1p-undefine54.7%
sub-neg54.7%
pow-to-exp54.7%
add-sqr-sqrt54.7%
sqrt-unprod54.7%
sqr-neg54.7%
sqrt-unprod1.9%
add-sqr-sqrt1.9%
sub-neg1.9%
log1p-undefine-0.0%
add-sqr-sqrt-0.0%
sqrt-unprod75.3%
sqr-neg75.3%
sqrt-unprod75.3%
add-sqr-sqrt75.3%
Applied egg-rr75.3%
Taylor expanded in u1 around 0 78.7%
Final simplification78.7%
(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(Float32(2.0) * 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}
\\
\left(2 \cdot \sqrt{u1}\right) \cdot \left(\pi \cdot u2\right)
\end{array}
Initial program 54.7%
Taylor expanded in u1 around 0 -0.0%
associate-*r*-0.0%
unpow2-0.0%
rem-square-sqrt4.0%
*-commutative4.0%
associate-*l*4.0%
*-commutative4.0%
mul-1-neg4.0%
Simplified4.0%
add-cbrt-cube4.0%
add-cbrt-cube4.0%
cbrt-unprod4.0%
pow34.0%
*-commutative4.0%
sqr-neg4.0%
add-sqr-sqrt-0.0%
sqrt-unprod78.6%
sqr-neg78.6%
add-sqr-sqrt78.6%
Applied egg-rr78.7%
Taylor expanded in u2 around 0 69.5%
associate-*r*69.5%
Simplified69.5%
Final simplification69.5%
(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 54.7%
Taylor expanded in u1 around 0 -0.0%
associate-*r*-0.0%
unpow2-0.0%
rem-square-sqrt4.0%
*-commutative4.0%
associate-*l*4.0%
*-commutative4.0%
mul-1-neg4.0%
Simplified4.0%
add-cbrt-cube4.0%
add-cbrt-cube4.0%
cbrt-unprod4.0%
pow34.0%
*-commutative4.0%
sqr-neg4.0%
add-sqr-sqrt-0.0%
sqrt-unprod78.6%
sqr-neg78.6%
add-sqr-sqrt78.6%
Applied egg-rr78.7%
Taylor expanded in u2 around 0 69.5%
associate-*r*69.5%
*-commutative69.5%
*-commutative69.5%
*-commutative69.5%
Simplified69.5%
Final simplification69.5%
(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 54.7%
Taylor expanded in u1 around 0 -0.0%
associate-*r*-0.0%
unpow2-0.0%
rem-square-sqrt4.0%
*-commutative4.0%
associate-*l*4.0%
*-commutative4.0%
mul-1-neg4.0%
Simplified4.0%
Taylor expanded in u2 around 0 4.2%
pow14.2%
*-commutative4.2%
*-commutative4.2%
Applied egg-rr4.2%
Simplified4.2%
herbie shell --seed 2024101
(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))))