
(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(2.0) * Float32(Float32(pi) * u2)))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(2 \cdot \left(\pi \cdot u2\right)\right)
\end{array}
Initial program 56.3%
sub-neg56.3%
log1p-def98.4%
associate-*l*98.4%
Simplified98.4%
Final simplification98.4%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= (* u2 (* 2.0 PI)) 0.006500000134110451) (* (sqrt (- (log1p (- u1)))) (* PI (* 2.0 u2))) (* (sin (* 2.0 (* PI u2))) (sqrt u1))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if ((u2 * (2.0f * ((float) M_PI))) <= 0.006500000134110451f) {
tmp = sqrtf(-log1pf(-u1)) * (((float) M_PI) * (2.0f * u2));
} else {
tmp = sinf((2.0f * (((float) M_PI) * u2))) * sqrtf(u1);
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (Float32(u2 * Float32(Float32(2.0) * Float32(pi))) <= Float32(0.006500000134110451)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(pi) * Float32(Float32(2.0) * u2))); else tmp = Float32(sin(Float32(Float32(2.0) * Float32(Float32(pi) * u2))) * sqrt(u1)); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u2 \cdot \left(2 \cdot \pi\right) \leq 0.006500000134110451:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(\pi \cdot \left(2 \cdot u2\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sin \left(2 \cdot \left(\pi \cdot u2\right)\right) \cdot \sqrt{u1}\\
\end{array}
\end{array}
if (*.f32 (*.f32 2 (PI.f32)) u2) < 0.00650000013Initial program 58.4%
sub-neg58.4%
log1p-def98.5%
associate-*l*98.5%
Simplified98.5%
add-cbrt-cube98.5%
add-cbrt-cube98.5%
cbrt-unprod98.5%
pow398.5%
pow398.4%
Applied egg-rr98.4%
Taylor expanded in u2 around 0 97.3%
associate-*r*97.3%
*-commutative97.3%
Simplified97.3%
if 0.00650000013 < (*.f32 (*.f32 2 (PI.f32)) u2) Initial program 51.5%
sub-neg51.5%
log1p-def98.0%
associate-*l*98.0%
Simplified98.0%
log1p-udef51.5%
sub-neg51.5%
add-sqr-sqrt51.5%
pow251.5%
Applied egg-rr78.6%
Taylor expanded in u1 around 0 80.5%
Final simplification92.2%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* PI (* 2.0 u2))))
(if (<= u1 0.00800000037997961)
(* (sin t_0) (sqrt (+ u1 (* 0.5 (* u1 u1)))))
(* (sqrt (- (log1p (- u1)))) t_0))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = ((float) M_PI) * (2.0f * u2);
float tmp;
if (u1 <= 0.00800000037997961f) {
tmp = sinf(t_0) * sqrtf((u1 + (0.5f * (u1 * u1))));
} else {
tmp = sqrtf(-log1pf(-u1)) * t_0;
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = Float32(Float32(pi) * Float32(Float32(2.0) * u2)) tmp = Float32(0.0) if (u1 <= Float32(0.00800000037997961)) tmp = Float32(sin(t_0) * sqrt(Float32(u1 + Float32(Float32(0.5) * Float32(u1 * u1))))); else tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * t_0); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \pi \cdot \left(2 \cdot u2\right)\\
\mathbf{if}\;u1 \leq 0.00800000037997961:\\
\;\;\;\;\sin t_0 \cdot \sqrt{u1 + 0.5 \cdot \left(u1 \cdot u1\right)}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot t_0\\
\end{array}
\end{array}
if u1 < 0.00800000038Initial program 45.7%
associate-*r*45.7%
add-cube-cbrt45.7%
pow345.7%
Applied egg-rr45.7%
Taylor expanded in u1 around 0 96.1%
+-commutative96.1%
mul-1-neg96.1%
unsub-neg96.1%
unpow296.1%
associate-*r*96.1%
Simplified96.1%
Taylor expanded in u2 around inf 97.5%
sub-neg97.5%
+-commutative97.5%
remove-double-neg97.5%
distribute-neg-in97.5%
*-commutative97.5%
unpow297.5%
associate-*r*97.5%
sub-neg97.5%
associate-*r*97.5%
*-commutative97.5%
*-commutative97.5%
sub-neg97.5%
associate-*r*97.5%
unpow297.5%
*-commutative97.5%
distribute-neg-in97.5%
Simplified97.5%
if 0.00800000038 < u1 Initial program 95.0%
sub-neg95.0%
log1p-def98.5%
associate-*l*98.5%
Simplified98.5%
add-cbrt-cube98.5%
add-cbrt-cube98.4%
cbrt-unprod98.6%
pow398.6%
pow398.5%
Applied egg-rr98.5%
Taylor expanded in u2 around 0 87.5%
associate-*r*87.5%
*-commutative87.5%
Simplified87.5%
Final simplification95.4%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= u2 0.0010000000474974513) (* (* PI u2) (* 2.0 (sqrt (+ u1 (* 0.5 (* u1 u1)))))) (* (sin (* 2.0 (* PI u2))) (sqrt u1))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if (u2 <= 0.0010000000474974513f) {
tmp = (((float) M_PI) * u2) * (2.0f * sqrtf((u1 + (0.5f * (u1 * u1)))));
} else {
tmp = sinf((2.0f * (((float) M_PI) * u2))) * sqrtf(u1);
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (u2 <= Float32(0.0010000000474974513)) tmp = Float32(Float32(Float32(pi) * u2) * Float32(Float32(2.0) * sqrt(Float32(u1 + Float32(Float32(0.5) * Float32(u1 * u1)))))); else tmp = Float32(sin(Float32(Float32(2.0) * Float32(Float32(pi) * u2))) * sqrt(u1)); end return tmp end
function tmp_2 = code(cosTheta_i, u1, u2) tmp = single(0.0); if (u2 <= single(0.0010000000474974513)) tmp = (single(pi) * u2) * (single(2.0) * sqrt((u1 + (single(0.5) * (u1 * u1))))); else tmp = sin((single(2.0) * (single(pi) * u2))) * sqrt(u1); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u2 \leq 0.0010000000474974513:\\
\;\;\;\;\left(\pi \cdot u2\right) \cdot \left(2 \cdot \sqrt{u1 + 0.5 \cdot \left(u1 \cdot u1\right)}\right)\\
\mathbf{else}:\\
\;\;\;\;\sin \left(2 \cdot \left(\pi \cdot u2\right)\right) \cdot \sqrt{u1}\\
\end{array}
\end{array}
if u2 < 0.00100000005Initial program 58.4%
associate-*r*58.4%
add-cube-cbrt58.4%
pow358.4%
Applied egg-rr58.4%
Taylor expanded in u1 around 0 87.0%
+-commutative87.0%
mul-1-neg87.0%
unsub-neg87.0%
unpow287.0%
associate-*r*87.0%
Simplified87.0%
Taylor expanded in u2 around 0 87.4%
associate-*r*87.4%
cancel-sign-sub-inv87.4%
metadata-eval87.4%
unpow287.4%
*-commutative87.4%
Simplified87.4%
if 0.00100000005 < u2 Initial program 51.5%
sub-neg51.5%
log1p-def98.0%
associate-*l*98.0%
Simplified98.0%
log1p-udef51.5%
sub-neg51.5%
add-sqr-sqrt51.5%
pow251.5%
Applied egg-rr78.6%
Taylor expanded in u1 around 0 80.5%
Final simplification85.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* 2.0 (* PI (* u2 (sqrt (+ u1 (* 0.5 (* u1 u1))))))))
float code(float cosTheta_i, float u1, float u2) {
return 2.0f * (((float) M_PI) * (u2 * sqrtf((u1 + (0.5f * (u1 * u1))))));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(2.0) * Float32(Float32(pi) * Float32(u2 * sqrt(Float32(u1 + Float32(Float32(0.5) * Float32(u1 * u1))))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(2.0) * (single(pi) * (u2 * sqrt((u1 + (single(0.5) * (u1 * u1)))))); end
\begin{array}{l}
\\
2 \cdot \left(\pi \cdot \left(u2 \cdot \sqrt{u1 + 0.5 \cdot \left(u1 \cdot u1\right)}\right)\right)
\end{array}
Initial program 56.3%
associate-*r*56.3%
add-cube-cbrt56.3%
pow356.3%
Applied egg-rr56.3%
Taylor expanded in u1 around 0 87.7%
+-commutative87.7%
mul-1-neg87.7%
unsub-neg87.7%
unpow287.7%
associate-*r*87.7%
Simplified87.7%
Taylor expanded in u2 around 0 74.5%
*-commutative74.5%
*-commutative74.5%
associate-*l*74.5%
cancel-sign-sub-inv74.5%
metadata-eval74.5%
unpow274.5%
Simplified74.5%
Final simplification74.5%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (* PI u2) (* 2.0 (sqrt (+ u1 (* 0.5 (* u1 u1)))))))
float code(float cosTheta_i, float u1, float u2) {
return (((float) M_PI) * u2) * (2.0f * sqrtf((u1 + (0.5f * (u1 * u1)))));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(Float32(pi) * u2) * Float32(Float32(2.0) * sqrt(Float32(u1 + Float32(Float32(0.5) * Float32(u1 * u1)))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = (single(pi) * u2) * (single(2.0) * sqrt((u1 + (single(0.5) * (u1 * u1))))); end
\begin{array}{l}
\\
\left(\pi \cdot u2\right) \cdot \left(2 \cdot \sqrt{u1 + 0.5 \cdot \left(u1 \cdot u1\right)}\right)
\end{array}
Initial program 56.3%
associate-*r*56.3%
add-cube-cbrt56.3%
pow356.3%
Applied egg-rr56.3%
Taylor expanded in u1 around 0 87.7%
+-commutative87.7%
mul-1-neg87.7%
unsub-neg87.7%
unpow287.7%
associate-*r*87.7%
Simplified87.7%
Taylor expanded in u2 around 0 74.5%
associate-*r*74.5%
cancel-sign-sub-inv74.5%
metadata-eval74.5%
unpow274.5%
*-commutative74.5%
Simplified74.5%
Final simplification74.5%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* 2.0 (* PI (sqrt (* u1 (* u2 u2))))))
float code(float cosTheta_i, float u1, float u2) {
return 2.0f * (((float) M_PI) * sqrtf((u1 * (u2 * u2))));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(2.0) * Float32(Float32(pi) * sqrt(Float32(u1 * Float32(u2 * u2))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(2.0) * (single(pi) * sqrt((u1 * (u2 * u2)))); end
\begin{array}{l}
\\
2 \cdot \left(\pi \cdot \sqrt{u1 \cdot \left(u2 \cdot u2\right)}\right)
\end{array}
Initial program 56.3%
Taylor expanded in u1 around 0 77.8%
mul-1-neg77.8%
Simplified77.8%
Taylor expanded in u2 around 0 66.6%
associate-*l*66.7%
Simplified66.7%
Taylor expanded in u2 around 0 66.6%
*-commutative66.6%
associate-*l*66.6%
Simplified66.6%
add-sqr-sqrt66.6%
sqrt-unprod66.6%
*-commutative66.6%
*-commutative66.6%
swap-sqr66.6%
add-sqr-sqrt66.7%
Applied egg-rr66.7%
Final simplification66.7%
(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 56.3%
Taylor expanded in u1 around 0 77.8%
mul-1-neg77.8%
Simplified77.8%
Taylor expanded in u2 around 0 66.6%
associate-*l*66.7%
Simplified66.7%
Final simplification66.7%
(FPCore (cosTheta_i u1 u2) :precision binary32 0.0)
float code(float cosTheta_i, float u1, float u2) {
return 0.0f;
}
real(4) function code(costheta_i, u1, u2)
real(4), intent (in) :: costheta_i
real(4), intent (in) :: u1
real(4), intent (in) :: u2
code = 0.0e0
end function
function code(cosTheta_i, u1, u2) return Float32(0.0) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(0.0); end
\begin{array}{l}
\\
0
\end{array}
Initial program 56.3%
Taylor expanded in u1 around 0 77.8%
mul-1-neg77.8%
Simplified77.8%
associate-*r*77.8%
add-cube-cbrt77.3%
pow377.4%
add-exp-log76.6%
pow-exp76.3%
Applied egg-rr76.3%
Taylor expanded in u2 around 0 7.2%
Final simplification7.2%
herbie shell --seed 2023178
(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))))