
(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 (let* ((t_0 (sqrt (* 2.0 PI)))) (* (sqrt (- (log1p (- u1)))) (sin (* t_0 (* u2 t_0))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = sqrtf((2.0f * ((float) M_PI)));
return sqrtf(-log1pf(-u1)) * sinf((t_0 * (u2 * t_0)));
}
function code(cosTheta_i, u1, u2) t_0 = sqrt(Float32(Float32(2.0) * Float32(pi))) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * sin(Float32(t_0 * Float32(u2 * t_0)))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{2 \cdot \pi}\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(t\_0 \cdot \left(u2 \cdot t\_0\right)\right)
\end{array}
\end{array}
Initial program 55.0%
sub-neg55.0%
log1p-define98.3%
Simplified98.3%
add-exp-log95.1%
*-commutative95.1%
associate-*r*95.1%
Applied egg-rr95.1%
rem-exp-log98.3%
associate-*l*98.3%
add-sqr-sqrt98.3%
associate-*r*98.5%
Applied egg-rr98.5%
Final simplification98.5%
(FPCore (cosTheta_i u1 u2) :precision binary32 (cbrt (* (pow (- (log1p (- u1))) 1.5) (pow (sin (* PI (* u2 2.0))) 3.0))))
float code(float cosTheta_i, float u1, float u2) {
return cbrtf((powf(-log1pf(-u1), 1.5f) * powf(sinf((((float) M_PI) * (u2 * 2.0f))), 3.0f)));
}
function code(cosTheta_i, u1, u2) return cbrt(Float32((Float32(-log1p(Float32(-u1))) ^ Float32(1.5)) * (sin(Float32(Float32(pi) * Float32(u2 * Float32(2.0)))) ^ Float32(3.0)))) end
\begin{array}{l}
\\
\sqrt[3]{{\left(-\mathsf{log1p}\left(-u1\right)\right)}^{1.5} \cdot {\sin \left(\pi \cdot \left(u2 \cdot 2\right)\right)}^{3}}
\end{array}
Initial program 55.0%
sub-neg55.0%
log1p-define98.3%
Simplified98.3%
add-exp-log95.1%
*-commutative95.1%
associate-*r*95.1%
Applied egg-rr95.1%
rem-exp-log98.3%
associate-*l*98.3%
add-cube-cbrt98.3%
associate-*r*98.3%
cbrt-unprod98.3%
*-commutative98.3%
*-commutative98.3%
swap-sqr98.3%
pow298.3%
metadata-eval98.3%
Applied egg-rr98.3%
add-cbrt-cube98.4%
add-cbrt-cube98.4%
cbrt-unprod98.2%
Applied egg-rr98.4%
*-commutative98.4%
unpow298.4%
metadata-eval98.4%
swap-sqr98.4%
unpow398.4%
rem-cbrt-cube98.4%
*-commutative98.4%
associate-*r*98.4%
*-commutative98.4%
associate-*r*98.4%
*-commutative98.4%
Simplified98.4%
Final simplification98.4%
(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 55.0%
sub-neg55.0%
log1p-define98.3%
Simplified98.3%
Final simplification98.3%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* 2.0 PI))))
(if (<= t_0 0.0031999999191612005)
(*
2.0
(*
(sqrt
(*
u1
(+ 1.0 (* u1 (+ 0.5 (* u1 (+ 0.3333333333333333 (* u1 0.25))))))))
(* 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 <= 0.0031999999191612005f) {
tmp = 2.0f * (sqrtf((u1 * (1.0f + (u1 * (0.5f + (u1 * (0.3333333333333333f + (u1 * 0.25f)))))))) * (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(0.0031999999191612005)) tmp = Float32(Float32(2.0) * Float32(sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(u1 * Float32(Float32(0.5) + Float32(u1 * Float32(Float32(0.3333333333333333) + Float32(u1 * Float32(0.25))))))))) * 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
function tmp_2 = code(cosTheta_i, u1, u2) t_0 = u2 * (single(2.0) * single(pi)); tmp = single(0.0); if (t_0 <= single(0.0031999999191612005)) tmp = single(2.0) * (sqrt((u1 * (single(1.0) + (u1 * (single(0.5) + (u1 * (single(0.3333333333333333) + (u1 * single(0.25))))))))) * (u2 * single(pi))); else tmp = sin(t_0) * sqrt((u1 * (single(1.0) + (u1 * single(0.5))))); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := u2 \cdot \left(2 \cdot \pi\right)\\
\mathbf{if}\;t\_0 \leq 0.0031999999191612005:\\
\;\;\;\;2 \cdot \left(\sqrt{u1 \cdot \left(1 + u1 \cdot \left(0.5 + u1 \cdot \left(0.3333333333333333 + u1 \cdot 0.25\right)\right)\right)} \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) < 0.00319999992Initial program 54.1%
Taylor expanded in u1 around 0 95.1%
*-commutative95.1%
Simplified95.1%
Taylor expanded in u2 around 0 94.3%
if 0.00319999992 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 56.7%
Taylor expanded in u1 around 0 87.1%
*-commutative87.1%
Simplified87.1%
Final simplification91.8%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* u2 (* 2.0 PI))) (sqrt (* u1 (+ 1.0 (* u1 (+ 0.5 (* u1 (+ 0.3333333333333333 (* u1 0.25))))))))))
float code(float cosTheta_i, float u1, float u2) {
return sinf((u2 * (2.0f * ((float) M_PI)))) * sqrtf((u1 * (1.0f + (u1 * (0.5f + (u1 * (0.3333333333333333f + (u1 * 0.25f))))))));
}
function code(cosTheta_i, u1, u2) return Float32(sin(Float32(u2 * Float32(Float32(2.0) * Float32(pi)))) * 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
function tmp = code(cosTheta_i, u1, u2) tmp = sin((u2 * (single(2.0) * single(pi)))) * sqrt((u1 * (single(1.0) + (u1 * (single(0.5) + (u1 * (single(0.3333333333333333) + (u1 * single(0.25))))))))); end
\begin{array}{l}
\\
\sin \left(u2 \cdot \left(2 \cdot \pi\right)\right) \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}
Initial program 55.0%
Taylor expanded in u1 around 0 94.3%
*-commutative94.3%
Simplified94.3%
Final simplification94.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* u2 (* 2.0 PI))) (sqrt (* u1 (+ 1.0 (* u1 (+ 0.5 (* u1 0.3333333333333333))))))))
float code(float cosTheta_i, float u1, float u2) {
return sinf((u2 * (2.0f * ((float) M_PI)))) * sqrtf((u1 * (1.0f + (u1 * (0.5f + (u1 * 0.3333333333333333f))))));
}
function code(cosTheta_i, u1, u2) return Float32(sin(Float32(u2 * Float32(Float32(2.0) * Float32(pi)))) * sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(u1 * Float32(Float32(0.5) + Float32(u1 * Float32(0.3333333333333333)))))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sin((u2 * (single(2.0) * single(pi)))) * sqrt((u1 * (single(1.0) + (u1 * (single(0.5) + (u1 * single(0.3333333333333333))))))); end
\begin{array}{l}
\\
\sin \left(u2 \cdot \left(2 \cdot \pi\right)\right) \cdot \sqrt{u1 \cdot \left(1 + u1 \cdot \left(0.5 + u1 \cdot 0.3333333333333333\right)\right)}
\end{array}
Initial program 55.0%
Taylor expanded in u1 around 0 92.5%
*-commutative92.5%
Simplified92.5%
Final simplification92.5%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* 2.0 PI))))
(if (<= t_0 0.006300000008195639)
(*
2.0
(*
(sqrt
(*
u1
(+ 1.0 (* u1 (+ 0.5 (* u1 (+ 0.3333333333333333 (* u1 0.25))))))))
(* 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 <= 0.006300000008195639f) {
tmp = 2.0f * (sqrtf((u1 * (1.0f + (u1 * (0.5f + (u1 * (0.3333333333333333f + (u1 * 0.25f)))))))) * (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(0.006300000008195639)) tmp = Float32(Float32(2.0) * Float32(sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(u1 * Float32(Float32(0.5) + Float32(u1 * Float32(Float32(0.3333333333333333) + Float32(u1 * Float32(0.25))))))))) * Float32(u2 * Float32(pi)))); else tmp = Float32(sin(t_0) * sqrt(u1)); end return tmp end
function tmp_2 = code(cosTheta_i, u1, u2) t_0 = u2 * (single(2.0) * single(pi)); tmp = single(0.0); if (t_0 <= single(0.006300000008195639)) tmp = single(2.0) * (sqrt((u1 * (single(1.0) + (u1 * (single(0.5) + (u1 * (single(0.3333333333333333) + (u1 * single(0.25))))))))) * (u2 * single(pi))); else tmp = sin(t_0) * sqrt(u1); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := u2 \cdot \left(2 \cdot \pi\right)\\
\mathbf{if}\;t\_0 \leq 0.006300000008195639:\\
\;\;\;\;2 \cdot \left(\sqrt{u1 \cdot \left(1 + u1 \cdot \left(0.5 + u1 \cdot \left(0.3333333333333333 + u1 \cdot 0.25\right)\right)\right)} \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) < 0.00630000001Initial program 54.3%
Taylor expanded in u1 around 0 94.7%
*-commutative94.7%
Simplified94.7%
Taylor expanded in u2 around 0 93.4%
if 0.00630000001 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 56.5%
Taylor expanded in u1 around 0 76.2%
Final simplification88.0%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(*
2.0
(*
(sqrt
(* u1 (+ 1.0 (* u1 (+ 0.5 (* u1 (+ 0.3333333333333333 (* u1 0.25))))))))
(* u2 PI))))
float code(float cosTheta_i, float u1, float u2) {
return 2.0f * (sqrtf((u1 * (1.0f + (u1 * (0.5f + (u1 * (0.3333333333333333f + (u1 * 0.25f)))))))) * (u2 * ((float) M_PI)));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(2.0) * Float32(sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(u1 * Float32(Float32(0.5) + Float32(u1 * Float32(Float32(0.3333333333333333) + Float32(u1 * Float32(0.25))))))))) * Float32(u2 * Float32(pi)))) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(2.0) * (sqrt((u1 * (single(1.0) + (u1 * (single(0.5) + (u1 * (single(0.3333333333333333) + (u1 * single(0.25))))))))) * (u2 * single(pi))); end
\begin{array}{l}
\\
2 \cdot \left(\sqrt{u1 \cdot \left(1 + u1 \cdot \left(0.5 + u1 \cdot \left(0.3333333333333333 + u1 \cdot 0.25\right)\right)\right)} \cdot \left(u2 \cdot \pi\right)\right)
\end{array}
Initial program 55.0%
Taylor expanded in u1 around 0 94.3%
*-commutative94.3%
Simplified94.3%
Taylor expanded in u2 around 0 79.3%
Final simplification79.3%
(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 55.0%
Taylor expanded in u1 around 0 77.8%
Taylor expanded in u2 around 0 68.0%
Final simplification68.0%
herbie shell --seed 2024112
(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))))