
(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 10 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 (cbrt (* (pow (sin (* 2.0 (* PI u2))) 3.0) (pow (- (log1p (- u1))) 1.5))))
float code(float cosTheta_i, float u1, float u2) {
return cbrtf((powf(sinf((2.0f * (((float) M_PI) * u2))), 3.0f) * powf(-log1pf(-u1), 1.5f)));
}
function code(cosTheta_i, u1, u2) return cbrt(Float32((sin(Float32(Float32(2.0) * Float32(Float32(pi) * u2))) ^ Float32(3.0)) * (Float32(-log1p(Float32(-u1))) ^ Float32(1.5)))) end
\begin{array}{l}
\\
\sqrt[3]{{\sin \left(2 \cdot \left(\pi \cdot u2\right)\right)}^{3} \cdot {\left(-\mathsf{log1p}\left(-u1\right)\right)}^{1.5}}
\end{array}
Initial program 57.4%
sub-neg57.4%
log1p-define98.5%
Simplified98.5%
add-cbrt-cube98.5%
add-cbrt-cube98.5%
cbrt-unprod98.5%
pow398.5%
pow398.5%
Applied egg-rr98.5%
*-commutative98.5%
pow-prod-down98.5%
associate-*l*98.5%
rem-cbrt-cube98.5%
*-commutative98.5%
associate-*r*98.5%
sin-298.4%
associate-*r*98.4%
*-commutative98.4%
*-commutative98.4%
Applied egg-rr98.4%
*-commutative98.4%
add-cbrt-cube98.3%
add-cbrt-cube98.3%
cbrt-unprod98.3%
Applied egg-rr98.6%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) (sin (* u2 (* 2.0 PI)))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * sinf((u2 * (2.0f * ((float) M_PI))));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * sin(Float32(u2 * Float32(Float32(2.0) * Float32(pi))))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(u2 \cdot \left(2 \cdot \pi\right)\right)
\end{array}
Initial program 57.4%
sub-neg57.4%
log1p-define98.5%
Simplified98.5%
Final simplification98.5%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* 2.0 PI))))
(if (<= t_0 0.0031500000040978193)
(* (sqrt (- (log1p (- u1)))) t_0)
(*
(sin t_0)
(sqrt
(*
u1
(+ 1.0 (* u1 (+ 0.5 (* u1 (- 0.3333333333333333 (* u1 -0.25))))))))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = u2 * (2.0f * ((float) M_PI));
float tmp;
if (t_0 <= 0.0031500000040978193f) {
tmp = sqrtf(-log1pf(-u1)) * t_0;
} else {
tmp = sinf(t_0) * sqrtf((u1 * (1.0f + (u1 * (0.5f + (u1 * (0.3333333333333333f - (u1 * -0.25f))))))));
}
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(0.0031500000040978193)) 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(Float32(0.3333333333333333) - Float32(u1 * Float32(-0.25)))))))))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := u2 \cdot \left(2 \cdot \pi\right)\\
\mathbf{if}\;t\_0 \leq 0.0031500000040978193:\\
\;\;\;\;\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 \left(0.3333333333333333 - u1 \cdot -0.25\right)\right)\right)}\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 0.00315Initial program 59.1%
sub-neg59.1%
log1p-define98.6%
Simplified98.6%
add-cbrt-cube98.6%
add-cbrt-cube98.6%
cbrt-unprod98.7%
pow398.7%
pow398.7%
Applied egg-rr98.7%
Taylor expanded in u2 around 0 98.1%
*-commutative98.1%
associate-*r*98.1%
Simplified98.1%
if 0.00315 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 53.8%
Taylor expanded in u1 around 0 95.6%
Final simplification97.3%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* 2.0 PI))))
(if (<= t_0 0.0031500000040978193)
(* (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 = u2 * (2.0f * ((float) M_PI));
float tmp;
if (t_0 <= 0.0031500000040978193f) {
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(u2 * Float32(Float32(2.0) * Float32(pi))) tmp = Float32(0.0) if (t_0 <= Float32(0.0031500000040978193)) 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 := u2 \cdot \left(2 \cdot \pi\right)\\
\mathbf{if}\;t\_0 \leq 0.0031500000040978193:\\
\;\;\;\;\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) < 0.00315Initial program 59.1%
sub-neg59.1%
log1p-define98.6%
Simplified98.6%
add-cbrt-cube98.6%
add-cbrt-cube98.6%
cbrt-unprod98.7%
pow398.7%
pow398.7%
Applied egg-rr98.7%
Taylor expanded in u2 around 0 98.1%
*-commutative98.1%
associate-*r*98.1%
Simplified98.1%
if 0.00315 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 53.8%
Taylor expanded in u1 around 0 93.2%
Final simplification96.5%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* 2.0 PI))))
(if (<= t_0 0.0044999998062849045)
(* (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 = u2 * (2.0f * ((float) M_PI));
float tmp;
if (t_0 <= 0.0044999998062849045f) {
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(u2 * Float32(Float32(2.0) * Float32(pi))) tmp = Float32(0.0) if (t_0 <= Float32(0.0044999998062849045)) 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 := u2 \cdot \left(2 \cdot \pi\right)\\
\mathbf{if}\;t\_0 \leq 0.0044999998062849045:\\
\;\;\;\;\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) < 0.00449999981Initial program 59.3%
sub-neg59.3%
log1p-define98.6%
Simplified98.6%
add-cbrt-cube98.6%
add-cbrt-cube98.6%
cbrt-unprod98.7%
pow398.7%
pow398.6%
Applied egg-rr98.6%
Taylor expanded in u2 around 0 97.6%
*-commutative97.6%
associate-*r*97.6%
Simplified97.6%
if 0.00449999981 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 52.9%
Taylor expanded in u1 around 0 89.9%
Final simplification95.3%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* 2.0 PI))))
(if (<= t_0 0.004600000102072954)
(* (sqrt (- (log1p (- u1)))) t_0)
(* (sin t_0) (sqrt u1)))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = u2 * (2.0f * ((float) M_PI));
float tmp;
if (t_0 <= 0.004600000102072954f) {
tmp = sqrtf(-log1pf(-u1)) * t_0;
} else {
tmp = sinf(t_0) * sqrtf(u1);
}
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(0.004600000102072954)) 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 := u2 \cdot \left(2 \cdot \pi\right)\\
\mathbf{if}\;t\_0 \leq 0.004600000102072954:\\
\;\;\;\;\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) < 0.0046000001Initial program 59.5%
sub-neg59.5%
log1p-define98.6%
Simplified98.6%
add-cbrt-cube98.6%
add-cbrt-cube98.6%
cbrt-unprod98.7%
pow398.7%
pow398.7%
Applied egg-rr98.7%
Taylor expanded in u2 around 0 97.5%
*-commutative97.5%
associate-*r*97.5%
Simplified97.5%
if 0.0046000001 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 52.3%
Taylor expanded in u1 around 0 -0.0%
associate-*r*-0.0%
unpow2-0.0%
rem-square-sqrt3.6%
*-commutative3.6%
associate-*l*3.6%
*-commutative3.6%
mul-1-neg3.6%
Simplified3.6%
expm1-log1p-u3.6%
expm1-undefine3.6%
*-commutative3.6%
add-sqr-sqrt-0.0%
sqrt-unprod57.8%
sqr-neg57.8%
add-sqr-sqrt57.8%
*-commutative57.8%
Applied egg-rr57.8%
log1p-undefine57.8%
rem-exp-log57.8%
+-commutative57.8%
associate--l+79.6%
*-commutative79.6%
*-commutative79.6%
metadata-eval79.6%
mul0-lft79.6%
distribute-rgt-in79.6%
+-rgt-identity79.6%
*-commutative79.6%
count-279.6%
distribute-rgt-out79.6%
count-279.6%
Simplified79.6%
Final simplification92.2%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* u2 (* 2.0 PI))) (sqrt u1)))
float code(float cosTheta_i, float u1, float u2) {
return sinf((u2 * (2.0f * ((float) M_PI)))) * sqrtf(u1);
}
function code(cosTheta_i, u1, u2) return Float32(sin(Float32(u2 * Float32(Float32(2.0) * Float32(pi)))) * sqrt(u1)) end
function tmp = code(cosTheta_i, u1, u2) tmp = sin((u2 * (single(2.0) * single(pi)))) * sqrt(u1); end
\begin{array}{l}
\\
\sin \left(u2 \cdot \left(2 \cdot \pi\right)\right) \cdot \sqrt{u1}
\end{array}
Initial program 57.4%
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%
expm1-log1p-u4.0%
expm1-undefine5.3%
*-commutative5.3%
add-sqr-sqrt-0.0%
sqrt-unprod30.5%
sqr-neg30.5%
add-sqr-sqrt30.5%
*-commutative30.5%
Applied egg-rr30.5%
log1p-undefine30.5%
rem-exp-log30.5%
+-commutative30.5%
associate--l+76.8%
*-commutative76.8%
*-commutative76.8%
metadata-eval76.8%
mul0-lft76.8%
distribute-rgt-in76.8%
+-rgt-identity76.8%
*-commutative76.8%
count-276.8%
distribute-rgt-out76.8%
count-276.8%
Simplified76.8%
Final simplification76.8%
(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 57.4%
add-sqr-sqrt56.9%
sqrt-unprod56.9%
swap-sqr56.9%
Applied egg-rr73.4%
Taylor expanded in u1 around 0 75.5%
*-commutative75.5%
associate-*r*75.5%
Simplified75.5%
Taylor expanded in u2 around 0 67.6%
Final simplification67.6%
(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 57.4%
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 4.3%
associate-*r*4.3%
Simplified4.3%
Final simplification4.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (* (sqrt u1) (* PI u2)) -2.0))
float code(float cosTheta_i, float u1, float u2) {
return (sqrtf(u1) * (((float) M_PI) * u2)) * -2.0f;
}
function code(cosTheta_i, u1, u2) return Float32(Float32(sqrt(u1) * Float32(Float32(pi) * u2)) * Float32(-2.0)) end
function tmp = code(cosTheta_i, u1, u2) tmp = (sqrt(u1) * (single(pi) * u2)) * single(-2.0); end
\begin{array}{l}
\\
\left(\sqrt{u1} \cdot \left(\pi \cdot u2\right)\right) \cdot -2
\end{array}
Initial program 57.4%
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 4.3%
Final simplification4.3%
herbie shell --seed 2024097
(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))))