
(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)))) (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 58.7%
sub-neg58.7%
log1p-define98.6%
Simplified98.6%
log1p-expm1-u98.6%
*-commutative98.6%
associate-*r*98.6%
Applied egg-rr98.6%
Final simplification98.6%
(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 58.7%
sub-neg58.7%
log1p-define98.6%
Simplified98.6%
Final simplification98.6%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(if (<= u1 0.054999999701976776)
(*
(sin (* u2 (* 2.0 PI)))
(sqrt
(* u1 (+ 1.0 (* u1 (+ 0.5 (* u1 (- 0.3333333333333333 (* u1 -0.25)))))))))
(* (sqrt (- (log1p (- u1)))) (* 2.0 (* u2 PI)))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if (u1 <= 0.054999999701976776f) {
tmp = sinf((u2 * (2.0f * ((float) M_PI)))) * sqrtf((u1 * (1.0f + (u1 * (0.5f + (u1 * (0.3333333333333333f - (u1 * -0.25f))))))));
} else {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (u2 * ((float) M_PI)));
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (u1 <= Float32(0.054999999701976776)) tmp = 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)))))))))); else tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(u2 * Float32(pi)))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u1 \leq 0.054999999701976776:\\
\;\;\;\;\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)}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(u2 \cdot \pi\right)\right)\\
\end{array}
\end{array}
if u1 < 0.0549999997Initial program 51.8%
Taylor expanded in u1 around 0 98.3%
if 0.0549999997 < u1 Initial program 98.1%
sub-neg98.1%
log1p-define98.9%
Simplified98.9%
log1p-expm1-u98.8%
*-commutative98.8%
associate-*r*98.8%
Applied egg-rr98.8%
log1p-expm1-u98.9%
associate-*l*98.9%
*-commutative98.9%
associate-*l*98.9%
*-commutative98.9%
sin-298.8%
*-commutative98.8%
Applied egg-rr98.8%
Taylor expanded in u2 around 0 84.1%
Final simplification96.2%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(if (<= u1 0.035599999129772186)
(*
(sin (* u2 (* 2.0 PI)))
(sqrt (* u1 (+ 1.0 (* u1 (- 0.5 (* u1 -0.3333333333333333)))))))
(* (sqrt (- (log1p (- u1)))) (* 2.0 (* u2 PI)))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if (u1 <= 0.035599999129772186f) {
tmp = sinf((u2 * (2.0f * ((float) M_PI)))) * sqrtf((u1 * (1.0f + (u1 * (0.5f - (u1 * -0.3333333333333333f))))));
} else {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (u2 * ((float) M_PI)));
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (u1 <= Float32(0.035599999129772186)) tmp = 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)))))))); else tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(u2 * Float32(pi)))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u1 \leq 0.035599999129772186:\\
\;\;\;\;\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)}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(u2 \cdot \pi\right)\right)\\
\end{array}
\end{array}
if u1 < 0.0355999991Initial program 50.2%
Taylor expanded in u1 around 0 97.9%
if 0.0355999991 < u1 Initial program 97.2%
sub-neg97.2%
log1p-define98.9%
Simplified98.9%
log1p-expm1-u98.8%
*-commutative98.8%
associate-*r*98.8%
Applied egg-rr98.8%
log1p-expm1-u98.9%
associate-*l*98.9%
*-commutative98.9%
associate-*l*98.9%
*-commutative98.9%
sin-298.8%
*-commutative98.8%
Applied egg-rr98.8%
Taylor expanded in u2 around 0 85.3%
Final simplification95.7%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* 2.0 PI))))
(if (<= t_0 0.011500000022351742)
(* (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 <= 0.011500000022351742f) {
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(0.011500000022351742)) 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 0.011500000022351742:\\
\;\;\;\;\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) < 0.0115Initial program 59.7%
sub-neg59.7%
log1p-define98.8%
Simplified98.8%
log1p-expm1-u98.8%
*-commutative98.8%
associate-*r*98.8%
Applied egg-rr98.8%
log1p-expm1-u98.8%
associate-*l*98.8%
*-commutative98.8%
associate-*l*98.8%
*-commutative98.8%
sin-298.7%
*-commutative98.7%
Applied egg-rr98.7%
Taylor expanded in u2 around 0 96.1%
if 0.0115 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 56.6%
sub-neg56.6%
log1p-define98.2%
Simplified98.2%
add-cbrt-cube98.2%
pow1/395.4%
Applied egg-rr73.8%
unpow1/375.3%
Simplified75.3%
Taylor expanded in u1 around 0 77.4%
*-commutative77.4%
associate-*l*77.4%
*-commutative77.4%
Simplified77.4%
Final simplification89.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= u1 0.012000000104308128) (* (sin (* u2 (* 2.0 PI))) (sqrt (* u1 (- 1.0 (* u1 -0.5))))) (* (sqrt (- (log1p (- u1)))) (* 2.0 (* u2 PI)))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if (u1 <= 0.012000000104308128f) {
tmp = sinf((u2 * (2.0f * ((float) M_PI)))) * sqrtf((u1 * (1.0f - (u1 * -0.5f))));
} else {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (u2 * ((float) M_PI)));
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (u1 <= Float32(0.012000000104308128)) tmp = Float32(sin(Float32(u2 * Float32(Float32(2.0) * Float32(pi)))) * sqrt(Float32(u1 * Float32(Float32(1.0) - Float32(u1 * Float32(-0.5)))))); else tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(u2 * Float32(pi)))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u1 \leq 0.012000000104308128:\\
\;\;\;\;\sin \left(u2 \cdot \left(2 \cdot \pi\right)\right) \cdot \sqrt{u1 \cdot \left(1 - u1 \cdot -0.5\right)}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(u2 \cdot \pi\right)\right)\\
\end{array}
\end{array}
if u1 < 0.0120000001Initial program 47.7%
Taylor expanded in u1 around 0 97.0%
if 0.0120000001 < u1 Initial program 97.0%
sub-neg97.0%
log1p-define98.9%
Simplified98.9%
log1p-expm1-u98.8%
*-commutative98.8%
associate-*r*98.8%
Applied egg-rr98.8%
log1p-expm1-u98.9%
associate-*l*98.9%
*-commutative98.9%
associate-*l*98.9%
*-commutative98.9%
sin-298.7%
*-commutative98.7%
Applied egg-rr98.7%
Taylor expanded in u2 around 0 84.6%
Final simplification94.3%
(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 58.7%
sub-neg58.7%
log1p-define98.6%
Simplified98.6%
add-cbrt-cube98.6%
pow1/395.8%
Applied egg-rr72.0%
unpow1/373.6%
Simplified73.6%
Taylor expanded in u1 around 0 75.7%
*-commutative75.7%
associate-*l*75.7%
*-commutative75.7%
Simplified75.7%
Final simplification75.7%
(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 58.7%
sub-neg58.7%
log1p-define98.6%
Simplified98.6%
add-cbrt-cube98.6%
pow1/395.8%
Applied egg-rr72.0%
unpow1/373.6%
Simplified73.6%
Taylor expanded in u2 around 0 38.0%
associate-*l*38.0%
log1p-define62.9%
Simplified62.9%
Taylor expanded in u1 around 0 64.5%
Final simplification64.5%
(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 58.7%
sub-neg58.7%
log1p-define98.6%
Simplified98.6%
add-cbrt-cube98.6%
pow1/395.8%
Applied egg-rr72.0%
unpow1/373.6%
Simplified73.6%
Taylor expanded in u2 around 0 38.0%
associate-*l*38.0%
log1p-define62.9%
Simplified62.9%
Taylor expanded in u1 around 0 64.5%
Final simplification64.5%
herbie shell --seed 2024067
(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))))