
(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 13 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 (* PI u2))))
(*
(sqrt (- (log1p (- u1))))
(+
(cos (* (* 2.0 PI) u2))
(fma (- t_0) (sin (expm1 (log1p (* PI u2)))) (* t_0 t_0))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = sinf((((float) M_PI) * u2));
return sqrtf(-log1pf(-u1)) * (cosf(((2.0f * ((float) M_PI)) * u2)) + fmaf(-t_0, sinf(expm1f(log1pf((((float) M_PI) * u2)))), (t_0 * t_0)));
}
function code(cosTheta_i, u1, u2) t_0 = sin(Float32(Float32(pi) * u2)) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(cos(Float32(Float32(Float32(2.0) * Float32(pi)) * u2)) + fma(Float32(-t_0), sin(expm1(log1p(Float32(Float32(pi) * u2)))), Float32(t_0 * t_0)))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sin \left(\pi \cdot u2\right)\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(\cos \left(\left(2 \cdot \pi\right) \cdot u2\right) + \mathsf{fma}\left(-t\_0, \sin \left(\mathsf{expm1}\left(\mathsf{log1p}\left(\pi \cdot u2\right)\right)\right), t\_0 \cdot t\_0\right)\right)
\end{array}
\end{array}
Initial program 55.7%
sub-neg55.7%
log1p-define99.1%
Simplified99.1%
associate-*l*99.1%
cos-298.8%
prod-diff98.9%
fmm-def98.8%
cos-299.1%
associate-*l*99.1%
*-commutative99.1%
associate-*l*99.1%
Applied egg-rr99.1%
associate-*r*99.1%
*-commutative99.1%
*-commutative99.1%
*-commutative99.1%
*-commutative99.1%
*-commutative99.1%
Simplified99.1%
expm1-log1p-u99.1%
*-commutative99.1%
Applied egg-rr99.1%
Final simplification99.1%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (sin (* PI u2))))
(*
(sqrt (- (log1p (- u1))))
(+ (cos (* (* 2.0 PI) u2)) (fma (- t_0) t_0 (* t_0 t_0))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = sinf((((float) M_PI) * u2));
return sqrtf(-log1pf(-u1)) * (cosf(((2.0f * ((float) M_PI)) * u2)) + fmaf(-t_0, t_0, (t_0 * t_0)));
}
function code(cosTheta_i, u1, u2) t_0 = sin(Float32(Float32(pi) * u2)) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(cos(Float32(Float32(Float32(2.0) * Float32(pi)) * u2)) + fma(Float32(-t_0), t_0, Float32(t_0 * t_0)))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sin \left(\pi \cdot u2\right)\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(\cos \left(\left(2 \cdot \pi\right) \cdot u2\right) + \mathsf{fma}\left(-t\_0, t\_0, t\_0 \cdot t\_0\right)\right)
\end{array}
\end{array}
Initial program 55.7%
sub-neg55.7%
log1p-define99.1%
Simplified99.1%
associate-*l*99.1%
cos-298.8%
prod-diff98.9%
fmm-def98.8%
cos-299.1%
associate-*l*99.1%
*-commutative99.1%
associate-*l*99.1%
Applied egg-rr99.1%
associate-*r*99.1%
*-commutative99.1%
*-commutative99.1%
*-commutative99.1%
*-commutative99.1%
*-commutative99.1%
Simplified99.1%
Final simplification99.1%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (cos (* (* 2.0 PI) u2))))
(if (<= t_0 0.9999964833259583)
(* t_0 (sqrt (* u1 (+ 1.0 (* u1 0.5)))))
(sqrt (- (log1p (- u1)))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = cosf(((2.0f * ((float) M_PI)) * u2));
float tmp;
if (t_0 <= 0.9999964833259583f) {
tmp = t_0 * sqrtf((u1 * (1.0f + (u1 * 0.5f))));
} else {
tmp = sqrtf(-log1pf(-u1));
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = cos(Float32(Float32(Float32(2.0) * Float32(pi)) * u2)) tmp = Float32(0.0) if (t_0 <= Float32(0.9999964833259583)) tmp = Float32(t_0 * sqrt(Float32(u1 * Float32(Float32(1.0) + 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(\left(2 \cdot \pi\right) \cdot u2\right)\\
\mathbf{if}\;t\_0 \leq 0.9999964833259583:\\
\;\;\;\;t\_0 \cdot \sqrt{u1 \cdot \left(1 + u1 \cdot 0.5\right)}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)}\\
\end{array}
\end{array}
if (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2)) < 0.999996483Initial program 55.3%
Taylor expanded in u1 around 0 88.3%
*-commutative88.3%
Simplified88.3%
if 0.999996483 < (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2)) Initial program 55.9%
sub-neg55.9%
log1p-define99.6%
Simplified99.6%
Taylor expanded in u2 around 0 98.2%
Final simplification95.1%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (cos (* (* 2.0 PI) u2))))
(if (<= t_0 0.9999899864196777)
(* t_0 (sqrt u1))
(sqrt (- (log1p (- u1)))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = cosf(((2.0f * ((float) M_PI)) * u2));
float tmp;
if (t_0 <= 0.9999899864196777f) {
tmp = t_0 * sqrtf(u1);
} else {
tmp = sqrtf(-log1pf(-u1));
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = cos(Float32(Float32(Float32(2.0) * Float32(pi)) * u2)) tmp = Float32(0.0) if (t_0 <= Float32(0.9999899864196777)) tmp = Float32(t_0 * sqrt(u1)); else tmp = sqrt(Float32(-log1p(Float32(-u1)))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \cos \left(\left(2 \cdot \pi\right) \cdot u2\right)\\
\mathbf{if}\;t\_0 \leq 0.9999899864196777:\\
\;\;\;\;t\_0 \cdot \sqrt{u1}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)}\\
\end{array}
\end{array}
if (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2)) < 0.999989986Initial program 54.3%
Taylor expanded in u1 around 0 78.5%
if 0.999989986 < (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2)) Initial program 56.3%
sub-neg56.3%
log1p-define99.5%
Simplified99.5%
Taylor expanded in u2 around 0 97.9%
Final simplification92.2%
(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 55.7%
sub-neg55.7%
log1p-define99.1%
Simplified99.1%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (cos (* (* 2.0 PI) u2)) (sqrt (* u1 (+ 1.0 (* u1 (+ 0.5 (* u1 (+ 0.3333333333333333 (* u1 0.25))))))))))
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 * (0.3333333333333333f + (u1 * 0.25f))))))));
}
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(0.3333333333333333) + Float32(u1 * Float32(0.25)))))))))) 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 * (single(0.3333333333333333) + (u1 * single(0.25))))))))); 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(0.3333333333333333 + u1 \cdot 0.25\right)\right)\right)}
\end{array}
Initial program 55.7%
Taylor expanded in u1 around 0 95.2%
*-commutative95.2%
Simplified95.2%
Final simplification95.2%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (cos (* (* 2.0 PI) u2)) (sqrt (* u1 (+ 1.0 (* u1 (+ 0.5 (* u1 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 * 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(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 * 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 0.3333333333333333\right)\right)}
\end{array}
Initial program 55.7%
Taylor expanded in u1 around 0 93.2%
*-commutative93.2%
Simplified93.2%
Final simplification93.2%
(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 55.7%
sub-neg55.7%
log1p-define99.1%
Simplified99.1%
Taylor expanded in u2 around 0 82.7%
Final simplification82.7%
(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 55.7%
sub-neg55.7%
log1p-define99.1%
Simplified99.1%
Taylor expanded in u2 around 0 82.7%
Taylor expanded in u1 around 0 80.6%
Final simplification80.6%
(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 55.7%
sub-neg55.7%
log1p-define99.1%
Simplified99.1%
Taylor expanded in u2 around 0 82.7%
Taylor expanded in u1 around 0 79.0%
Final simplification79.0%
(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 55.7%
sub-neg55.7%
log1p-define99.1%
Simplified99.1%
Taylor expanded in u2 around 0 82.7%
Taylor expanded in u1 around 0 75.9%
Final simplification75.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (pow u1 0.5))
float code(float cosTheta_i, float u1, float u2) {
return powf(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 = u1 ** 0.5e0
end function
function code(cosTheta_i, u1, u2) return u1 ^ Float32(0.5) end
function tmp = code(cosTheta_i, u1, u2) tmp = u1 ^ single(0.5); end
\begin{array}{l}
\\
{u1}^{0.5}
\end{array}
Initial program 55.7%
sub-neg55.7%
log1p-define99.1%
Simplified99.1%
Taylor expanded in u2 around 0 82.7%
Taylor expanded in u1 around 0 68.1%
*-rgt-identity68.1%
pow1/268.1%
Applied egg-rr68.1%
(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 55.7%
sub-neg55.7%
log1p-define99.1%
Simplified99.1%
Taylor expanded in u2 around 0 82.7%
Taylor expanded in u1 around 0 68.1%
Taylor expanded in u1 around 0 68.1%
herbie shell --seed 2024181
(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))))