
(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 (* (sqrt (- (log1p (- u1)))) (log1p (expm1 (sin (* (* u2 2.0) PI))))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * log1pf(expm1f(sinf(((u2 * 2.0f) * ((float) M_PI)))));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * log1p(expm1(sin(Float32(Float32(u2 * Float32(2.0)) * Float32(pi)))))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \mathsf{log1p}\left(\mathsf{expm1}\left(\sin \left(\left(u2 \cdot 2\right) \cdot \pi\right)\right)\right)
\end{array}
Initial program 56.9%
sub-neg56.9%
log1p-define98.5%
Simplified98.5%
log1p-expm1-u98.5%
*-commutative98.5%
associate-*r*98.5%
Applied egg-rr98.5%
Final simplification98.5%
(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 56.9%
sub-neg56.9%
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 0.0009500000160187483)
(* (sqrt (- (log1p (- u1)))) (* 2.0 (* u2 PI)))
(*
(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 <= 0.0009500000160187483f) {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (u2 * ((float) M_PI)));
} 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(0.0009500000160187483)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(u2 * Float32(pi)))); 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 0.0009500000160187483:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(u2 \cdot \pi\right)\right)\\
\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) < 9.50000016e-4Initial program 58.6%
sub-neg58.6%
log1p-define98.7%
Simplified98.7%
log1p-expm1-u98.7%
*-commutative98.7%
associate-*r*98.7%
Applied egg-rr98.7%
log1p-expm1-u98.7%
associate-*l*98.7%
*-commutative98.7%
associate-*l*98.7%
*-commutative98.7%
sin-298.7%
*-commutative98.7%
Applied egg-rr98.7%
Taylor expanded in u2 around 0 98.6%
if 9.50000016e-4 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 53.8%
Taylor expanded in u1 around 0 93.7%
Final simplification96.9%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* 2.0 PI))))
(if (<= t_0 0.0009500000160187483)
(* (sqrt (- (log1p (- u1)))) (* 2.0 (* u2 PI)))
(*
(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 <= 0.0009500000160187483f) {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (u2 * ((float) M_PI)));
} 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(0.0009500000160187483)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(u2 * Float32(pi)))); 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 0.0009500000160187483:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(u2 \cdot \pi\right)\right)\\
\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) < 9.50000016e-4Initial program 58.6%
sub-neg58.6%
log1p-define98.7%
Simplified98.7%
log1p-expm1-u98.7%
*-commutative98.7%
associate-*r*98.7%
Applied egg-rr98.7%
log1p-expm1-u98.7%
associate-*l*98.7%
*-commutative98.7%
associate-*l*98.7%
*-commutative98.7%
sin-298.7%
*-commutative98.7%
Applied egg-rr98.7%
Taylor expanded in u2 around 0 98.6%
if 9.50000016e-4 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 53.8%
Taylor expanded in u1 around 0 91.8%
Final simplification96.2%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* 2.0 PI))))
(if (<= t_0 0.0009500000160187483)
(* (sqrt (- (log1p (- u1)))) (* 2.0 (* u2 PI)))
(* (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 <= 0.0009500000160187483f) {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (u2 * ((float) M_PI)));
} 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(0.0009500000160187483)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(u2 * Float32(pi)))); 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 0.0009500000160187483:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(u2 \cdot \pi\right)\right)\\
\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) < 9.50000016e-4Initial program 58.6%
sub-neg58.6%
log1p-define98.7%
Simplified98.7%
log1p-expm1-u98.7%
*-commutative98.7%
associate-*r*98.7%
Applied egg-rr98.7%
log1p-expm1-u98.7%
associate-*l*98.7%
*-commutative98.7%
associate-*l*98.7%
*-commutative98.7%
sin-298.7%
*-commutative98.7%
Applied egg-rr98.7%
Taylor expanded in u2 around 0 98.6%
if 9.50000016e-4 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 53.8%
Taylor expanded in u1 around 0 88.7%
Final simplification95.2%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* 2.0 PI))))
(if (<= t_0 0.007000000216066837)
(* (sqrt (- (log1p (- u1)))) (* 2.0 (* u2 PI)))
(* (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 <= 0.007000000216066837f) {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (u2 * ((float) M_PI)));
} 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(0.007000000216066837)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(u2 * Float32(pi)))); 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 0.007000000216066837:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(u2 \cdot \pi\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sin t\_0 \cdot \sqrt{u1}\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 0.00700000022Initial program 58.0%
sub-neg58.0%
log1p-define98.7%
Simplified98.7%
log1p-expm1-u98.7%
*-commutative98.7%
associate-*r*98.7%
Applied egg-rr98.7%
log1p-expm1-u98.7%
associate-*l*98.7%
*-commutative98.7%
associate-*l*98.7%
*-commutative98.7%
sin-298.6%
*-commutative98.6%
Applied egg-rr98.6%
Taylor expanded in u2 around 0 97.4%
if 0.00700000022 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 53.6%
sub-neg53.6%
log1p-define97.9%
Simplified97.9%
add-cbrt-cube97.8%
pow1/395.1%
Applied egg-rr73.3%
unpow1/374.9%
Simplified74.9%
Taylor expanded in u1 around 0 76.7%
*-commutative76.7%
associate-*l*76.7%
*-commutative76.7%
Simplified76.7%
Final simplification92.3%
(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 56.9%
sub-neg56.9%
log1p-define98.5%
Simplified98.5%
add-cbrt-cube98.5%
pow1/395.8%
Applied egg-rr72.5%
unpow1/374.4%
Simplified74.4%
Taylor expanded in u1 around 0 76.4%
*-commutative76.4%
associate-*l*76.4%
*-commutative76.4%
Simplified76.4%
Final simplification76.4%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (* (* u2 PI) (sqrt u1)) -2.0))
float code(float cosTheta_i, float u1, float u2) {
return ((u2 * ((float) M_PI)) * sqrtf(u1)) * -2.0f;
}
function code(cosTheta_i, u1, u2) return Float32(Float32(Float32(u2 * Float32(pi)) * sqrt(u1)) * Float32(-2.0)) end
function tmp = code(cosTheta_i, u1, u2) tmp = ((u2 * single(pi)) * sqrt(u1)) * single(-2.0); end
\begin{array}{l}
\\
\left(\left(u2 \cdot \pi\right) \cdot \sqrt{u1}\right) \cdot -2
\end{array}
Initial program 56.9%
Taylor expanded in u1 around 0 -0.0%
associate-*r*-0.0%
unpow2-0.0%
rem-square-sqrt4.1%
*-commutative4.1%
associate-*l*4.1%
*-commutative4.1%
mul-1-neg4.1%
Simplified4.1%
Taylor expanded in u2 around 0 4.4%
Final simplification4.4%
(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 56.9%
sub-neg56.9%
log1p-define98.5%
Simplified98.5%
add-cbrt-cube98.5%
pow1/395.8%
Applied egg-rr72.5%
Taylor expanded in u2 around 0 36.9%
Simplified66.8%
Taylor expanded in u1 around 0 68.3%
Final simplification68.3%
(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(Float32(u2 * 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(\left(u2 \cdot \pi\right) \cdot \sqrt{u1}\right)
\end{array}
Initial program 56.9%
sub-neg56.9%
log1p-define98.5%
Simplified98.5%
add-cbrt-cube98.5%
pow1/395.8%
Applied egg-rr72.5%
Taylor expanded in u2 around 0 36.9%
Simplified66.8%
Taylor expanded in u1 around 0 68.3%
Final simplification68.3%
herbie shell --seed 2024075
(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))))