
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log (- 1.0 u1)))) (cos (* (* 2.0 PI) u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-logf((1.0f - u1))) * cosf(((2.0f * ((float) M_PI)) * u2));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log(Float32(Float32(1.0) - u1)))) * cos(Float32(Float32(Float32(2.0) * Float32(pi)) * u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-log((single(1.0) - u1))) * cos(((single(2.0) * single(pi)) * u2)); end
\begin{array}{l}
\\
\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \pi\right) \cdot u2\right)
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log (- 1.0 u1)))) (cos (* (* 2.0 PI) u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-logf((1.0f - u1))) * cosf(((2.0f * ((float) M_PI)) * u2));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log(Float32(Float32(1.0) - u1)))) * cos(Float32(Float32(Float32(2.0) * Float32(pi)) * u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-log((single(1.0) - u1))) * cos(((single(2.0) * single(pi)) * u2)); end
\begin{array}{l}
\\
\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \pi\right) \cdot u2\right)
\end{array}
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) (cos (* 2.0 (* PI u2)))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * cosf((2.0f * (((float) M_PI) * u2)));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * cos(Float32(Float32(2.0) * Float32(Float32(pi) * u2)))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \cos \left(2 \cdot \left(\pi \cdot u2\right)\right)
\end{array}
Initial program 60.4%
sub-neg60.4%
log1p-def99.1%
associate-*l*99.1%
Simplified99.1%
Final simplification99.1%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (cos (* u2 (* 2.0 PI)))))
(if (<= t_0 0.9999977350234985)
(* t_0 (sqrt (- u1 (* u1 (* u1 -0.5)))))
(sqrt (- (log1p (- u1)))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = cosf((u2 * (2.0f * ((float) M_PI))));
float tmp;
if (t_0 <= 0.9999977350234985f) {
tmp = t_0 * sqrtf((u1 - (u1 * (u1 * -0.5f))));
} else {
tmp = sqrtf(-log1pf(-u1));
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = cos(Float32(u2 * Float32(Float32(2.0) * Float32(pi)))) tmp = Float32(0.0) if (t_0 <= Float32(0.9999977350234985)) tmp = Float32(t_0 * sqrt(Float32(u1 - Float32(u1 * Float32(u1 * Float32(-0.5)))))); else tmp = sqrt(Float32(-log1p(Float32(-u1)))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \cos \left(u2 \cdot \left(2 \cdot \pi\right)\right)\\
\mathbf{if}\;t_0 \leq 0.9999977350234985:\\
\;\;\;\;t_0 \cdot \sqrt{u1 - u1 \cdot \left(u1 \cdot -0.5\right)}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)}\\
\end{array}
\end{array}
if (cos.f32 (*.f32 (*.f32 2 (PI.f32)) u2)) < 0.999997735Initial program 52.4%
Taylor expanded in u1 around 0 88.0%
+-commutative49.4%
mul-1-neg49.4%
unsub-neg49.4%
unpow249.4%
associate-*r*49.4%
Simplified88.0%
if 0.999997735 < (cos.f32 (*.f32 (*.f32 2 (PI.f32)) u2)) Initial program 64.4%
sub-neg64.4%
log1p-def99.6%
associate-*l*99.6%
Simplified99.6%
add-log-exp99.6%
log-pow99.6%
Applied egg-rr99.6%
Taylor expanded in u2 around 0 98.6%
Final simplification95.1%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= (cos (* u2 (* 2.0 PI))) 0.9999935030937195) (* (cos (* PI (* 2.0 u2))) (sqrt u1)) (sqrt (+ (log1p (fma u1 u1 u1)) (* u1 (* u1 u1))))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if (cosf((u2 * (2.0f * ((float) M_PI)))) <= 0.9999935030937195f) {
tmp = cosf((((float) M_PI) * (2.0f * u2))) * sqrtf(u1);
} else {
tmp = sqrtf((log1pf(fmaf(u1, u1, u1)) + (u1 * (u1 * u1))));
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (cos(Float32(u2 * Float32(Float32(2.0) * Float32(pi)))) <= Float32(0.9999935030937195)) tmp = Float32(cos(Float32(Float32(pi) * Float32(Float32(2.0) * u2))) * sqrt(u1)); else tmp = sqrt(Float32(log1p(fma(u1, u1, u1)) + Float32(u1 * Float32(u1 * u1)))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\cos \left(u2 \cdot \left(2 \cdot \pi\right)\right) \leq 0.9999935030937195:\\
\;\;\;\;\cos \left(\pi \cdot \left(2 \cdot u2\right)\right) \cdot \sqrt{u1}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\mathsf{log1p}\left(\mathsf{fma}\left(u1, u1, u1\right)\right) + u1 \cdot \left(u1 \cdot u1\right)}\\
\end{array}
\end{array}
if (cos.f32 (*.f32 (*.f32 2 (PI.f32)) u2)) < 0.999993503Initial program 52.4%
add-cube-cbrt52.4%
pow352.4%
Applied egg-rr76.7%
Taylor expanded in u1 around 0 78.7%
pow-base-178.7%
associate-*r*78.7%
*-lft-identity78.7%
*-commutative78.7%
*-commutative78.7%
associate-*r*78.7%
*-commutative78.7%
Simplified78.7%
if 0.999993503 < (cos.f32 (*.f32 (*.f32 2 (PI.f32)) u2)) Initial program 63.6%
Taylor expanded in u2 around 0 63.2%
flip3--60.4%
div-inv60.4%
log-prod60.3%
metadata-eval60.3%
pow360.3%
sub-neg60.3%
distribute-rgt-neg-out60.3%
add-sqr-sqrt-0.0%
sqrt-unprod46.3%
sqr-neg46.3%
sqrt-unprod46.3%
add-sqr-sqrt46.3%
log1p-udef44.9%
pow344.9%
metadata-eval44.9%
*-un-lft-identity44.9%
fma-def44.9%
Applied egg-rr44.9%
log-div45.2%
metadata-eval45.2%
log1p-def81.0%
neg-sub081.0%
sub-neg81.0%
Simplified81.0%
Taylor expanded in u1 around 0 80.9%
unpow380.9%
add-sqr-sqrt80.9%
sqrt-unprod80.9%
sqr-neg80.9%
sqrt-unprod-0.0%
add-sqr-sqrt92.1%
neg-mul-192.1%
associate-*r*92.1%
Applied egg-rr92.1%
*-commutative92.1%
associate-*l*92.1%
*-commutative92.1%
mul-1-neg92.1%
Simplified92.1%
Final simplification88.2%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= (- 1.0 u1) 0.996999979019165) (sqrt (- (log (- 1.0 u1)))) (* (cos (* u2 (* 2.0 PI))) (sqrt (- u1 (* u1 (* u1 -0.5)))))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if ((1.0f - u1) <= 0.996999979019165f) {
tmp = sqrtf(-logf((1.0f - u1)));
} else {
tmp = cosf((u2 * (2.0f * ((float) M_PI)))) * sqrtf((u1 - (u1 * (u1 * -0.5f))));
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (Float32(Float32(1.0) - u1) <= Float32(0.996999979019165)) tmp = sqrt(Float32(-log(Float32(Float32(1.0) - u1)))); else tmp = Float32(cos(Float32(u2 * Float32(Float32(2.0) * Float32(pi)))) * sqrt(Float32(u1 - Float32(u1 * Float32(u1 * Float32(-0.5)))))); end return tmp end
function tmp_2 = code(cosTheta_i, u1, u2) tmp = single(0.0); if ((single(1.0) - u1) <= single(0.996999979019165)) tmp = sqrt(-log((single(1.0) - u1))); else tmp = cos((u2 * (single(2.0) * single(pi)))) * sqrt((u1 - (u1 * (u1 * single(-0.5))))); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u1 \leq 0.996999979019165:\\
\;\;\;\;\sqrt{-\log \left(1 - u1\right)}\\
\mathbf{else}:\\
\;\;\;\;\cos \left(u2 \cdot \left(2 \cdot \pi\right)\right) \cdot \sqrt{u1 - u1 \cdot \left(u1 \cdot -0.5\right)}\\
\end{array}
\end{array}
if (-.f32 1 u1) < 0.996999979Initial program 95.1%
Taylor expanded in u2 around 0 83.9%
if 0.996999979 < (-.f32 1 u1) Initial program 44.7%
Taylor expanded in u1 around 0 98.6%
+-commutative80.6%
mul-1-neg80.6%
unsub-neg80.6%
unpow280.6%
associate-*r*80.6%
Simplified98.6%
Final simplification94.0%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= (- 1.0 u1) 0.9980599880218506) (sqrt (- (log (- 1.0 u1)))) (* (cos (* PI (* 2.0 u2))) (sqrt u1))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if ((1.0f - u1) <= 0.9980599880218506f) {
tmp = sqrtf(-logf((1.0f - u1)));
} else {
tmp = cosf((((float) M_PI) * (2.0f * u2))) * sqrtf(u1);
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (Float32(Float32(1.0) - u1) <= Float32(0.9980599880218506)) tmp = sqrt(Float32(-log(Float32(Float32(1.0) - u1)))); else tmp = Float32(cos(Float32(Float32(pi) * Float32(Float32(2.0) * u2))) * sqrt(u1)); end return tmp end
function tmp_2 = code(cosTheta_i, u1, u2) tmp = single(0.0); if ((single(1.0) - u1) <= single(0.9980599880218506)) tmp = sqrt(-log((single(1.0) - u1))); else tmp = cos((single(pi) * (single(2.0) * u2))) * sqrt(u1); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u1 \leq 0.9980599880218506:\\
\;\;\;\;\sqrt{-\log \left(1 - u1\right)}\\
\mathbf{else}:\\
\;\;\;\;\cos \left(\pi \cdot \left(2 \cdot u2\right)\right) \cdot \sqrt{u1}\\
\end{array}
\end{array}
if (-.f32 1 u1) < 0.998059988Initial program 94.6%
Taylor expanded in u2 around 0 83.5%
if 0.998059988 < (-.f32 1 u1) Initial program 43.5%
add-cube-cbrt43.4%
pow343.5%
Applied egg-rr86.7%
Taylor expanded in u1 around 0 88.9%
pow-base-188.9%
associate-*r*88.9%
*-lft-identity88.9%
*-commutative88.9%
*-commutative88.9%
associate-*r*88.9%
*-commutative88.9%
Simplified88.9%
Final simplification87.1%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= (- 1.0 u1) 0.996999979019165) (sqrt (- (log (- 1.0 u1)))) (sqrt (- u1 (* u1 (* u1 -0.5))))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if ((1.0f - u1) <= 0.996999979019165f) {
tmp = sqrtf(-logf((1.0f - u1)));
} else {
tmp = sqrtf((u1 - (u1 * (u1 * -0.5f))));
}
return tmp;
}
real(4) function code(costheta_i, u1, u2)
real(4), intent (in) :: costheta_i
real(4), intent (in) :: u1
real(4), intent (in) :: u2
real(4) :: tmp
if ((1.0e0 - u1) <= 0.996999979019165e0) then
tmp = sqrt(-log((1.0e0 - u1)))
else
tmp = sqrt((u1 - (u1 * (u1 * (-0.5e0)))))
end if
code = tmp
end function
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (Float32(Float32(1.0) - u1) <= Float32(0.996999979019165)) tmp = sqrt(Float32(-log(Float32(Float32(1.0) - u1)))); else tmp = sqrt(Float32(u1 - Float32(u1 * Float32(u1 * Float32(-0.5))))); end return tmp end
function tmp_2 = code(cosTheta_i, u1, u2) tmp = single(0.0); if ((single(1.0) - u1) <= single(0.996999979019165)) tmp = sqrt(-log((single(1.0) - u1))); else tmp = sqrt((u1 - (u1 * (u1 * single(-0.5))))); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u1 \leq 0.996999979019165:\\
\;\;\;\;\sqrt{-\log \left(1 - u1\right)}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1 - u1 \cdot \left(u1 \cdot -0.5\right)}\\
\end{array}
\end{array}
if (-.f32 1 u1) < 0.996999979Initial program 95.1%
Taylor expanded in u2 around 0 83.9%
if 0.996999979 < (-.f32 1 u1) Initial program 44.7%
Taylor expanded in u2 around 0 40.6%
Taylor expanded in u1 around 0 80.6%
+-commutative80.6%
mul-1-neg80.6%
unsub-neg80.6%
unpow280.6%
associate-*r*80.6%
Simplified80.6%
Final simplification81.6%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (- u1 (* u1 (* u1 -0.5)))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((u1 - (u1 * (u1 * -0.5f))));
}
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 = sqrt((u1 - (u1 * (u1 * (-0.5e0)))))
end function
function code(cosTheta_i, u1, u2) return sqrt(Float32(u1 - Float32(u1 * Float32(u1 * Float32(-0.5))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt((u1 - (u1 * (u1 * single(-0.5))))); end
\begin{array}{l}
\\
\sqrt{u1 - u1 \cdot \left(u1 \cdot -0.5\right)}
\end{array}
Initial program 60.4%
Taylor expanded in u2 around 0 54.1%
Taylor expanded in u1 around 0 72.9%
+-commutative72.9%
mul-1-neg72.9%
unsub-neg72.9%
unpow272.9%
associate-*r*72.9%
Simplified72.9%
Final simplification72.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt u1))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(u1);
}
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 = sqrt(u1)
end function
function code(cosTheta_i, u1, u2) return sqrt(u1) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(u1); end
\begin{array}{l}
\\
\sqrt{u1}
\end{array}
Initial program 60.4%
add-cube-cbrt60.3%
pow360.3%
Applied egg-rr71.9%
Taylor expanded in u2 around 0 38.1%
Taylor expanded in u1 around 0 64.0%
Final simplification64.0%
herbie shell --seed 2023207
(FPCore (cosTheta_i u1 u2)
:name "Beckmann Sample, near normal, slope_x"
: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)))) (cos (* (* 2.0 PI) u2))))