
(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 12 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 (cbrt (* (pow (* 2.0 PI) 3.0) (pow u2 3.0))))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * cosf(cbrtf((powf((2.0f * ((float) M_PI)), 3.0f) * powf(u2, 3.0f))));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * cos(cbrt(Float32((Float32(Float32(2.0) * Float32(pi)) ^ Float32(3.0)) * (u2 ^ Float32(3.0)))))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \cos \left(\sqrt[3]{{\left(2 \cdot \pi\right)}^{3} \cdot {u2}^{3}}\right)
\end{array}
Initial program 57.6%
sub-neg57.6%
log1p-define99.1%
Simplified99.1%
add-cbrt-cube99.1%
add-cbrt-cube99.1%
cbrt-unprod99.2%
pow399.2%
pow399.2%
Applied egg-rr99.2%
Final simplification99.2%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) (cos (log (+ 1.0 (expm1 (* 2.0 (* PI u2))))))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * cosf(logf((1.0f + expm1f((2.0f * (((float) M_PI) * u2))))));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * cos(log(Float32(Float32(1.0) + expm1(Float32(Float32(2.0) * Float32(Float32(pi) * u2))))))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \cos \log \left(1 + \mathsf{expm1}\left(2 \cdot \left(\pi \cdot u2\right)\right)\right)
\end{array}
Initial program 57.6%
sub-neg57.6%
log1p-define99.1%
Simplified99.1%
log1p-expm1-u99.1%
log1p-undefine99.2%
associate-*l*99.2%
Applied egg-rr99.2%
Final simplification99.2%
(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(Float32(2.0) * Float32(pi)) * u2))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \cos \left(\left(2 \cdot \pi\right) \cdot u2\right)
\end{array}
Initial program 57.6%
sub-neg57.6%
log1p-define99.1%
Simplified99.1%
Final simplification99.1%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.001500000013038516)
(sqrt (- (log1p (- u1))))
(*
(cos t_0)
(sqrt (* u1 (+ 1.0 (* u1 (- 0.5 (* u1 -0.3333333333333333))))))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = (2.0f * ((float) M_PI)) * u2;
float tmp;
if (t_0 <= 0.001500000013038516f) {
tmp = sqrtf(-log1pf(-u1));
} else {
tmp = cosf(t_0) * sqrtf((u1 * (1.0f + (u1 * (0.5f - (u1 * -0.3333333333333333f))))));
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = Float32(Float32(Float32(2.0) * Float32(pi)) * u2) tmp = Float32(0.0) if (t_0 <= Float32(0.001500000013038516)) tmp = sqrt(Float32(-log1p(Float32(-u1)))); else tmp = Float32(cos(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 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.001500000013038516:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)}\\
\mathbf{else}:\\
\;\;\;\;\cos 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) < 0.00150000001Initial program 55.8%
sub-neg55.8%
log1p-define99.7%
Simplified99.7%
Taylor expanded in u2 around 0 99.3%
if 0.00150000001 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 60.6%
Taylor expanded in u1 around 0 92.6%
Final simplification96.8%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.0020000000949949026)
(sqrt (- (log1p (- u1))))
(* (cos t_0) (sqrt (* u1 (- 1.0 (* u1 -0.5))))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = (2.0f * ((float) M_PI)) * u2;
float tmp;
if (t_0 <= 0.0020000000949949026f) {
tmp = sqrtf(-log1pf(-u1));
} else {
tmp = cosf(t_0) * sqrtf((u1 * (1.0f - (u1 * -0.5f))));
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = Float32(Float32(Float32(2.0) * Float32(pi)) * u2) tmp = Float32(0.0) if (t_0 <= Float32(0.0020000000949949026)) tmp = sqrt(Float32(-log1p(Float32(-u1)))); else tmp = Float32(cos(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 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.0020000000949949026:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)}\\
\mathbf{else}:\\
\;\;\;\;\cos 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) < 0.00200000009Initial program 56.2%
sub-neg56.2%
log1p-define99.7%
Simplified99.7%
Taylor expanded in u2 around 0 99.2%
if 0.00200000009 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 60.0%
Taylor expanded in u1 around 0 88.8%
Final simplification95.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (cos (* (* 2.0 PI) u2)) (sqrt (* u1 (+ 1.0 (* u1 (- 0.5 (* u1 (- (* u1 -0.25) 0.3333333333333333)))))))))
float code(float cosTheta_i, float u1, float u2) {
return cosf(((2.0f * ((float) M_PI)) * u2)) * sqrtf((u1 * (1.0f + (u1 * (0.5f - (u1 * ((u1 * -0.25f) - 0.3333333333333333f)))))));
}
function code(cosTheta_i, u1, u2) return Float32(cos(Float32(Float32(Float32(2.0) * Float32(pi)) * u2)) * sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(u1 * Float32(Float32(0.5) - Float32(u1 * Float32(Float32(u1 * Float32(-0.25)) - Float32(0.3333333333333333))))))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = cos(((single(2.0) * single(pi)) * u2)) * sqrt((u1 * (single(1.0) + (u1 * (single(0.5) - (u1 * ((u1 * single(-0.25)) - single(0.3333333333333333)))))))); end
\begin{array}{l}
\\
\cos \left(\left(2 \cdot \pi\right) \cdot u2\right) \cdot \sqrt{u1 \cdot \left(1 + u1 \cdot \left(0.5 - u1 \cdot \left(u1 \cdot -0.25 - 0.3333333333333333\right)\right)\right)}
\end{array}
Initial program 57.6%
Taylor expanded in u1 around 0 95.0%
Final simplification95.0%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.0020000000949949026)
(sqrt (- (log1p (- u1))))
(* (cos t_0) (sqrt u1)))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = (2.0f * ((float) M_PI)) * u2;
float tmp;
if (t_0 <= 0.0020000000949949026f) {
tmp = sqrtf(-log1pf(-u1));
} else {
tmp = cosf(t_0) * sqrtf(u1);
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = Float32(Float32(Float32(2.0) * Float32(pi)) * u2) tmp = Float32(0.0) if (t_0 <= Float32(0.0020000000949949026)) tmp = sqrt(Float32(-log1p(Float32(-u1)))); else tmp = Float32(cos(t_0) * sqrt(u1)); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.0020000000949949026:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)}\\
\mathbf{else}:\\
\;\;\;\;\cos t\_0 \cdot \sqrt{u1}\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 0.00200000009Initial program 56.2%
sub-neg56.2%
log1p-define99.7%
Simplified99.7%
Taylor expanded in u2 around 0 99.2%
if 0.00200000009 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 60.0%
add-cube-cbrt59.7%
pow359.9%
Applied egg-rr73.9%
Taylor expanded in u1 around 0 76.4%
*-commutative76.4%
associate-*r*76.4%
rem-square-sqrt76.5%
unpow276.5%
unpow276.5%
rem-square-sqrt76.4%
associate-*r*76.4%
*-commutative76.4%
*-commutative76.4%
associate-*r*76.4%
Simplified76.4%
Final simplification90.7%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (- (log1p (- u1)))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1));
}
function code(cosTheta_i, u1, u2) return sqrt(Float32(-log1p(Float32(-u1)))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)}
\end{array}
Initial program 57.6%
sub-neg57.6%
log1p-define99.1%
Simplified99.1%
Taylor expanded in u2 around 0 80.3%
Final simplification80.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (* u1 (+ 1.0 (* u1 (- 0.5 (* u1 (- (* u1 -0.25) 0.3333333333333333))))))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((u1 * (1.0f + (u1 * (0.5f - (u1 * ((u1 * -0.25f) - 0.3333333333333333f)))))));
}
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 * (1.0e0 + (u1 * (0.5e0 - (u1 * ((u1 * (-0.25e0)) - 0.3333333333333333e0)))))))
end function
function code(cosTheta_i, u1, u2) return sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(u1 * Float32(Float32(0.5) - Float32(u1 * Float32(Float32(u1 * Float32(-0.25)) - Float32(0.3333333333333333)))))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt((u1 * (single(1.0) + (u1 * (single(0.5) - (u1 * ((u1 * single(-0.25)) - single(0.3333333333333333)))))))); end
\begin{array}{l}
\\
\sqrt{u1 \cdot \left(1 + u1 \cdot \left(0.5 - u1 \cdot \left(u1 \cdot -0.25 - 0.3333333333333333\right)\right)\right)}
\end{array}
Initial program 57.6%
sub-neg57.6%
log1p-define99.1%
Simplified99.1%
Taylor expanded in u2 around 0 80.3%
Taylor expanded in u1 around 0 77.3%
Final simplification77.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (* u1 (+ 1.0 (* u1 (- 0.5 (* u1 -0.3333333333333333)))))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((u1 * (1.0f + (u1 * (0.5f - (u1 * -0.3333333333333333f))))));
}
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 * (1.0e0 + (u1 * (0.5e0 - (u1 * (-0.3333333333333333e0)))))))
end function
function code(cosTheta_i, u1, u2) return 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 = sqrt((u1 * (single(1.0) + (u1 * (single(0.5) - (u1 * single(-0.3333333333333333))))))); end
\begin{array}{l}
\\
\sqrt{u1 \cdot \left(1 + u1 \cdot \left(0.5 - u1 \cdot -0.3333333333333333\right)\right)}
\end{array}
Initial program 57.6%
sub-neg57.6%
log1p-define99.1%
Simplified99.1%
Taylor expanded in u2 around 0 80.3%
Taylor expanded in u1 around 0 76.1%
Final simplification76.1%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (* u1 (- 1.0 (* u1 -0.5)))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((u1 * (1.0f - (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 * (1.0e0 - (u1 * (-0.5e0)))))
end function
function code(cosTheta_i, u1, u2) return sqrt(Float32(u1 * Float32(Float32(1.0) - Float32(u1 * Float32(-0.5))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt((u1 * (single(1.0) - (u1 * single(-0.5))))); end
\begin{array}{l}
\\
\sqrt{u1 \cdot \left(1 - u1 \cdot -0.5\right)}
\end{array}
Initial program 57.6%
sub-neg57.6%
log1p-define99.1%
Simplified99.1%
Taylor expanded in u2 around 0 80.3%
Taylor expanded in u1 around 0 73.9%
Final simplification73.9%
(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 57.6%
add-cube-cbrt57.4%
pow357.5%
Applied egg-rr75.2%
Taylor expanded in u1 around 0 77.8%
*-commutative77.8%
associate-*r*77.8%
rem-square-sqrt77.9%
unpow277.9%
unpow277.9%
rem-square-sqrt77.8%
associate-*r*77.8%
*-commutative77.8%
*-commutative77.8%
associate-*r*77.8%
Simplified77.8%
Taylor expanded in u2 around 0 66.6%
Final simplification66.6%
herbie shell --seed 2024076
(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))))