
(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
(let* ((t_0 (sin (* u2 PI))))
(*
(sqrt (- (log1p (- u1))))
(+
(cos (* u2 (* 2.0 PI)))
(-
(+
0.5
(* (cos (pow (pow (* PI (* u2 2.0)) 3.0) 0.3333333333333333)) -0.5))
(* t_0 t_0))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = sinf((u2 * ((float) M_PI)));
return sqrtf(-log1pf(-u1)) * (cosf((u2 * (2.0f * ((float) M_PI)))) + ((0.5f + (cosf(powf(powf((((float) M_PI) * (u2 * 2.0f)), 3.0f), 0.3333333333333333f)) * -0.5f)) - (t_0 * t_0)));
}
function code(cosTheta_i, u1, u2) t_0 = sin(Float32(u2 * Float32(pi))) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(cos(Float32(u2 * Float32(Float32(2.0) * Float32(pi)))) + Float32(Float32(Float32(0.5) + Float32(cos(((Float32(Float32(pi) * Float32(u2 * Float32(2.0))) ^ Float32(3.0)) ^ Float32(0.3333333333333333))) * Float32(-0.5))) - Float32(t_0 * t_0)))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sin \left(u2 \cdot \pi\right)\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(\cos \left(u2 \cdot \left(2 \cdot \pi\right)\right) + \left(\left(0.5 + \cos \left({\left({\left(\pi \cdot \left(u2 \cdot 2\right)\right)}^{3}\right)}^{0.3333333333333333}\right) \cdot -0.5\right) - t\_0 \cdot t\_0\right)\right)
\end{array}
\end{array}
Initial program 56.4%
sub-neg56.4%
log1p-define98.9%
Simplified98.9%
associate-*l*98.9%
cos-298.9%
prod-diff98.9%
fma-neg98.8%
cos-298.9%
associate-*l*98.9%
*-commutative98.9%
associate-*l*98.9%
sqr-sin-a99.0%
associate-*l*99.0%
Applied egg-rr99.0%
*-commutative99.0%
*-commutative99.0%
associate-*l*99.0%
fma-undefine99.0%
+-commutative99.0%
distribute-lft-neg-out99.0%
unsub-neg99.0%
Simplified99.0%
add-cbrt-cube99.0%
pow1/399.1%
pow399.1%
*-commutative99.1%
*-commutative99.1%
associate-*r*99.1%
*-commutative99.1%
Applied egg-rr99.1%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (cos (* u2 (* 2.0 PI)))))
(*
(sqrt (- (log1p (- u1))))
(+
t_0
(-
(+ 0.5 (* t_0 -0.5))
(* (sin (* u2 PI)) (sin (log (+ 1.0 (expm1 (* u2 PI)))))))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = cosf((u2 * (2.0f * ((float) M_PI))));
return sqrtf(-log1pf(-u1)) * (t_0 + ((0.5f + (t_0 * -0.5f)) - (sinf((u2 * ((float) M_PI))) * sinf(logf((1.0f + expm1f((u2 * ((float) M_PI)))))))));
}
function code(cosTheta_i, u1, u2) t_0 = cos(Float32(u2 * Float32(Float32(2.0) * Float32(pi)))) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(t_0 + Float32(Float32(Float32(0.5) + Float32(t_0 * Float32(-0.5))) - Float32(sin(Float32(u2 * Float32(pi))) * sin(log(Float32(Float32(1.0) + expm1(Float32(u2 * Float32(pi)))))))))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \cos \left(u2 \cdot \left(2 \cdot \pi\right)\right)\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(t\_0 + \left(\left(0.5 + t\_0 \cdot -0.5\right) - \sin \left(u2 \cdot \pi\right) \cdot \sin \log \left(1 + \mathsf{expm1}\left(u2 \cdot \pi\right)\right)\right)\right)
\end{array}
\end{array}
Initial program 56.4%
sub-neg56.4%
log1p-define98.9%
Simplified98.9%
associate-*l*98.9%
cos-298.9%
prod-diff98.9%
fma-neg98.8%
cos-298.9%
associate-*l*98.9%
*-commutative98.9%
associate-*l*98.9%
sqr-sin-a99.0%
associate-*l*99.0%
Applied egg-rr99.0%
*-commutative99.0%
*-commutative99.0%
associate-*l*99.0%
fma-undefine99.0%
+-commutative99.0%
distribute-lft-neg-out99.0%
unsub-neg99.0%
Simplified99.0%
log1p-expm1-u99.0%
log1p-undefine99.0%
Applied egg-rr99.0%
(FPCore (cosTheta_i u1 u2) :precision binary32 (let* ((t_0 (sin (* u2 PI))) (t_1 (cos (* u2 (* 2.0 PI))))) (* (sqrt (- (log1p (- u1)))) (+ t_1 (- (+ 0.5 (* t_1 -0.5)) (* t_0 t_0))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = sinf((u2 * ((float) M_PI)));
float t_1 = cosf((u2 * (2.0f * ((float) M_PI))));
return sqrtf(-log1pf(-u1)) * (t_1 + ((0.5f + (t_1 * -0.5f)) - (t_0 * t_0)));
}
function code(cosTheta_i, u1, u2) t_0 = sin(Float32(u2 * Float32(pi))) t_1 = cos(Float32(u2 * Float32(Float32(2.0) * Float32(pi)))) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(t_1 + Float32(Float32(Float32(0.5) + Float32(t_1 * Float32(-0.5))) - Float32(t_0 * t_0)))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sin \left(u2 \cdot \pi\right)\\
t_1 := \cos \left(u2 \cdot \left(2 \cdot \pi\right)\right)\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(t\_1 + \left(\left(0.5 + t\_1 \cdot -0.5\right) - t\_0 \cdot t\_0\right)\right)
\end{array}
\end{array}
Initial program 56.4%
sub-neg56.4%
log1p-define98.9%
Simplified98.9%
associate-*l*98.9%
cos-298.9%
prod-diff98.9%
fma-neg98.8%
cos-298.9%
associate-*l*98.9%
*-commutative98.9%
associate-*l*98.9%
sqr-sin-a99.0%
associate-*l*99.0%
Applied egg-rr99.0%
*-commutative99.0%
*-commutative99.0%
associate-*l*99.0%
fma-undefine99.0%
+-commutative99.0%
distribute-lft-neg-out99.0%
unsub-neg99.0%
Simplified99.0%
(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 56.4%
sub-neg56.4%
log1p-define98.9%
Simplified98.9%
add-cbrt-cube98.9%
add-cbrt-cube98.9%
cbrt-unprod98.9%
pow398.9%
pow398.9%
Applied egg-rr98.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) (cos (* u2 (* 2.0 PI)))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * cosf((u2 * (2.0f * ((float) M_PI))));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * cos(Float32(u2 * Float32(Float32(2.0) * Float32(pi))))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \cos \left(u2 \cdot \left(2 \cdot \pi\right)\right)
\end{array}
Initial program 56.4%
sub-neg56.4%
log1p-define98.9%
Simplified98.9%
Final simplification98.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= (* u2 (* 2.0 PI)) 0.0010000000474974513) (sqrt (- (log1p (- u1)))) (* (sqrt (* u1 (- 1.0 (* u1 -0.5)))) (cos (* PI (* u2 2.0))))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if ((u2 * (2.0f * ((float) M_PI))) <= 0.0010000000474974513f) {
tmp = sqrtf(-log1pf(-u1));
} else {
tmp = sqrtf((u1 * (1.0f - (u1 * -0.5f)))) * cosf((((float) M_PI) * (u2 * 2.0f)));
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (Float32(u2 * Float32(Float32(2.0) * Float32(pi))) <= Float32(0.0010000000474974513)) tmp = sqrt(Float32(-log1p(Float32(-u1)))); else tmp = Float32(sqrt(Float32(u1 * Float32(Float32(1.0) - Float32(u1 * Float32(-0.5))))) * cos(Float32(Float32(pi) * Float32(u2 * Float32(2.0))))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u2 \cdot \left(2 \cdot \pi\right) \leq 0.0010000000474974513:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1 \cdot \left(1 - u1 \cdot -0.5\right)} \cdot \cos \left(\pi \cdot \left(u2 \cdot 2\right)\right)\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 0.00100000005Initial program 57.1%
sub-neg57.1%
log1p-define99.5%
Simplified99.5%
Taylor expanded in u2 around 0 99.2%
if 0.00100000005 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 55.4%
sub-neg55.4%
log1p-define98.1%
Simplified98.1%
add-log-exp97.7%
*-commutative97.7%
associate-*l*97.7%
Applied egg-rr97.7%
Taylor expanded in u1 around 0 88.6%
rem-log-exp88.8%
*-commutative88.8%
Applied egg-rr88.8%
Final simplification95.0%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* 2.0 PI))))
(if (<= t_0 0.0022499999031424522)
(sqrt (- (log1p (- u1))))
(* (cos 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 <= 0.0022499999031424522f) {
tmp = sqrtf(-log1pf(-u1));
} else {
tmp = cosf(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(0.0022499999031424522)) 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 := u2 \cdot \left(2 \cdot \pi\right)\\
\mathbf{if}\;t\_0 \leq 0.0022499999031424522:\\
\;\;\;\;\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) < 0.0022499999Initial program 58.0%
sub-neg58.0%
log1p-define99.4%
Simplified99.4%
Taylor expanded in u2 around 0 98.3%
if 0.0022499999 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 53.5%
sub-neg53.5%
log1p-define98.0%
Simplified98.0%
add-sqr-sqrt97.1%
pow297.1%
pow1/297.1%
sqrt-pow197.1%
add-sqr-sqrt97.1%
sqrt-unprod97.1%
sqr-neg97.1%
sqrt-unprod-0.0%
add-sqr-sqrt-0.0%
add-sqr-sqrt-0.0%
sqrt-unprod76.3%
sqr-neg76.3%
sqrt-unprod76.4%
add-sqr-sqrt76.3%
metadata-eval76.3%
Applied egg-rr76.3%
Taylor expanded in u1 around 0 78.6%
Final simplification91.3%
(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 56.4%
sub-neg56.4%
log1p-define98.9%
Simplified98.9%
Taylor expanded in u2 around 0 79.7%
Final simplification79.7%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (* u1 (+ 1.0 (* u1 (+ 0.5 (* u1 (- 0.3333333333333333 (* u1 -0.25)))))))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((u1 * (1.0f + (u1 * (0.5f + (u1 * (0.3333333333333333f - (u1 * -0.25f))))))));
}
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 - (u1 * (-0.25e0)))))))))
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(0.3333333333333333) - Float32(u1 * Float32(-0.25))))))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt((u1 * (single(1.0) + (u1 * (single(0.5) + (u1 * (single(0.3333333333333333) - (u1 * single(-0.25))))))))); end
\begin{array}{l}
\\
\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 56.4%
sub-neg56.4%
log1p-define98.9%
Simplified98.9%
Taylor expanded in u2 around 0 79.7%
Taylor expanded in u1 around 0 76.4%
Final simplification76.4%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (* u1 (- 1.0 (* u1 (- (* u1 -0.3333333333333333) 0.5))))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((u1 * (1.0f - (u1 * ((u1 * -0.3333333333333333f) - 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 * ((u1 * (-0.3333333333333333e0)) - 0.5e0)))))
end function
function code(cosTheta_i, u1, u2) return sqrt(Float32(u1 * Float32(Float32(1.0) - Float32(u1 * Float32(Float32(u1 * Float32(-0.3333333333333333)) - Float32(0.5)))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt((u1 * (single(1.0) - (u1 * ((u1 * single(-0.3333333333333333)) - single(0.5)))))); end
\begin{array}{l}
\\
\sqrt{u1 \cdot \left(1 - u1 \cdot \left(u1 \cdot -0.3333333333333333 - 0.5\right)\right)}
\end{array}
Initial program 56.4%
sub-neg56.4%
log1p-define98.9%
Simplified98.9%
Taylor expanded in u2 around 0 79.7%
Taylor expanded in u1 around 0 75.1%
Final simplification75.1%
(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 56.4%
sub-neg56.4%
log1p-define98.9%
Simplified98.9%
Taylor expanded in u2 around 0 79.7%
Taylor expanded in u1 around 0 72.3%
Final simplification72.3%
(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 56.4%
sub-neg56.4%
log1p-define98.9%
Simplified98.9%
Taylor expanded in u2 around 0 79.7%
add-cbrt-cube79.7%
pow1/377.6%
Applied egg-rr62.2%
Taylor expanded in u1 around 0 64.7%
Final simplification64.7%
herbie shell --seed 2024088
(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))))