
(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 11 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 (* (+ 1.0 (+ -1.0 (cos (* u2 (* PI 2.0))))) (sqrt (- (log1p (- u1))))))
float code(float cosTheta_i, float u1, float u2) {
return (1.0f + (-1.0f + cosf((u2 * (((float) M_PI) * 2.0f))))) * sqrtf(-log1pf(-u1));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(Float32(1.0) + Float32(Float32(-1.0) + cos(Float32(u2 * Float32(Float32(pi) * Float32(2.0)))))) * sqrt(Float32(-log1p(Float32(-u1))))) end
\begin{array}{l}
\\
\left(1 + \left(-1 + \cos \left(u2 \cdot \left(\pi \cdot 2\right)\right)\right)\right) \cdot \sqrt{-\mathsf{log1p}\left(-u1\right)}
\end{array}
Initial program 56.5%
sub-neg56.5%
log1p-define99.2%
Simplified99.2%
add-log-exp97.4%
associate-*l*97.4%
Applied egg-rr97.4%
expm1-log1p-u99.0%
rem-log-exp99.1%
*-commutative99.1%
associate-*l*99.1%
Applied egg-rr99.1%
expm1-undefine99.0%
sub-neg99.0%
log1p-expm1-u99.0%
log1p-undefine99.0%
rem-exp-log99.0%
expm1-log1p-u99.0%
metadata-eval99.0%
Applied egg-rr99.0%
associate-+l+99.2%
associate-*r*99.2%
*-commutative99.2%
associate-*r*99.2%
Simplified99.2%
Final simplification99.2%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (cos (* u2 (* PI 2.0)))))
(if (<= t_0 0.9999995231628418)
(*
t_0
(sqrt
(*
u1
(+ 1.0 (* u1 (+ 0.5 (* u1 (- 0.3333333333333333 (* u1 -0.25)))))))))
(sqrt (- (log1p (- u1)))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = cosf((u2 * (((float) M_PI) * 2.0f)));
float tmp;
if (t_0 <= 0.9999995231628418f) {
tmp = t_0 * sqrtf((u1 * (1.0f + (u1 * (0.5f + (u1 * (0.3333333333333333f - (u1 * -0.25f))))))));
} else {
tmp = sqrtf(-log1pf(-u1));
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = cos(Float32(u2 * Float32(Float32(pi) * Float32(2.0)))) tmp = Float32(0.0) if (t_0 <= Float32(0.9999995231628418)) tmp = Float32(t_0 * sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(u1 * Float32(Float32(0.5) + Float32(u1 * Float32(Float32(0.3333333333333333) - Float32(u1 * Float32(-0.25)))))))))); else tmp = sqrt(Float32(-log1p(Float32(-u1)))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \cos \left(u2 \cdot \left(\pi \cdot 2\right)\right)\\
\mathbf{if}\;t\_0 \leq 0.9999995231628418:\\
\;\;\;\;t\_0 \cdot \sqrt{u1 \cdot \left(1 + u1 \cdot \left(0.5 + u1 \cdot \left(0.3333333333333333 - u1 \cdot -0.25\right)\right)\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)) < 0.999999523Initial program 53.3%
Taylor expanded in u1 around 0 93.7%
if 0.999999523 < (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2)) Initial program 58.2%
sub-neg58.2%
log1p-define99.6%
Simplified99.6%
Taylor expanded in u2 around 0 99.3%
Final simplification97.4%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (cos (* u2 (* PI 2.0)))))
(if (<= t_0 0.9999988079071045)
(* t_0 (sqrt u1))
(sqrt (- (log1p (- u1)))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = cosf((u2 * (((float) M_PI) * 2.0f)));
float tmp;
if (t_0 <= 0.9999988079071045f) {
tmp = t_0 * sqrtf(u1);
} else {
tmp = sqrtf(-log1pf(-u1));
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = cos(Float32(u2 * Float32(Float32(pi) * Float32(2.0)))) tmp = Float32(0.0) if (t_0 <= Float32(0.9999988079071045)) 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(u2 \cdot \left(\pi \cdot 2\right)\right)\\
\mathbf{if}\;t\_0 \leq 0.9999988079071045:\\
\;\;\;\;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)) < 0.999998808Initial program 51.9%
add-sqr-sqrt51.9%
pow251.9%
pow1/251.9%
sqrt-pow152.0%
add-sqr-sqrt52.0%
sqrt-unprod52.0%
sqr-neg52.0%
sqrt-unprod2.1%
add-sqr-sqrt2.1%
sub-neg2.1%
log1p-undefine-0.0%
add-sqr-sqrt-0.0%
sqrt-unprod76.2%
sqr-neg76.2%
sqrt-unprod76.0%
add-sqr-sqrt76.2%
metadata-eval76.2%
Applied egg-rr76.2%
Taylor expanded in u1 around 0 78.2%
if 0.999998808 < (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2)) Initial program 58.5%
sub-neg58.5%
log1p-define99.6%
Simplified99.6%
Taylor expanded in u2 around 0 98.7%
Final simplification92.5%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (cos (* u2 (* PI 2.0))) (sqrt (- (log1p (- u1))))))
float code(float cosTheta_i, float u1, float u2) {
return cosf((u2 * (((float) M_PI) * 2.0f))) * sqrtf(-log1pf(-u1));
}
function code(cosTheta_i, u1, u2) return Float32(cos(Float32(u2 * Float32(Float32(pi) * Float32(2.0)))) * sqrt(Float32(-log1p(Float32(-u1))))) end
\begin{array}{l}
\\
\cos \left(u2 \cdot \left(\pi \cdot 2\right)\right) \cdot \sqrt{-\mathsf{log1p}\left(-u1\right)}
\end{array}
Initial program 56.5%
sub-neg56.5%
log1p-define99.2%
Simplified99.2%
Final simplification99.2%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* PI 2.0))))
(if (<= t_0 0.0009500000160187483)
(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 = u2 * (((float) M_PI) * 2.0f);
float tmp;
if (t_0 <= 0.0009500000160187483f) {
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(u2 * Float32(Float32(pi) * Float32(2.0))) tmp = Float32(0.0) if (t_0 <= Float32(0.0009500000160187483)) 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 := u2 \cdot \left(\pi \cdot 2\right)\\
\mathbf{if}\;t\_0 \leq 0.0009500000160187483:\\
\;\;\;\;\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) < 9.50000016e-4Initial program 58.2%
sub-neg58.2%
log1p-define99.6%
Simplified99.6%
Taylor expanded in u2 around 0 99.3%
if 9.50000016e-4 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 53.3%
Taylor expanded in u1 around 0 91.8%
Final simplification96.7%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* PI 2.0))))
(if (<= t_0 0.0009500000160187483)
(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 = u2 * (((float) M_PI) * 2.0f);
float tmp;
if (t_0 <= 0.0009500000160187483f) {
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(u2 * Float32(Float32(pi) * Float32(2.0))) tmp = Float32(0.0) if (t_0 <= Float32(0.0009500000160187483)) 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 := u2 \cdot \left(\pi \cdot 2\right)\\
\mathbf{if}\;t\_0 \leq 0.0009500000160187483:\\
\;\;\;\;\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) < 9.50000016e-4Initial program 58.2%
sub-neg58.2%
log1p-define99.6%
Simplified99.6%
Taylor expanded in u2 around 0 99.3%
if 9.50000016e-4 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 53.3%
Taylor expanded in u1 around 0 88.8%
Final simplification95.7%
(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 56.5%
sub-neg56.5%
log1p-define99.2%
Simplified99.2%
Taylor expanded in u2 around 0 83.6%
Final simplification83.6%
(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 56.5%
sub-neg56.5%
log1p-define99.2%
Simplified99.2%
Taylor expanded in u2 around 0 83.6%
Taylor expanded in u1 around 0 79.5%
Final simplification79.5%
(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 56.5%
sub-neg56.5%
log1p-define99.2%
Simplified99.2%
Taylor expanded in u2 around 0 83.6%
Taylor expanded in u1 around 0 78.2%
Final simplification78.2%
(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 56.5%
sub-neg56.5%
log1p-define99.2%
Simplified99.2%
Taylor expanded in u2 around 0 83.6%
Taylor expanded in u1 around 0 75.1%
Final simplification75.1%
(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 56.5%
add-sqr-sqrt56.5%
pow256.5%
pow1/256.5%
sqrt-pow156.5%
add-sqr-sqrt56.5%
sqrt-unprod56.5%
sqr-neg56.5%
sqrt-unprod1.7%
add-sqr-sqrt1.7%
sub-neg1.7%
log1p-undefine-0.0%
add-sqr-sqrt-0.0%
sqrt-unprod74.1%
sqr-neg74.1%
sqrt-unprod74.0%
add-sqr-sqrt74.1%
metadata-eval74.1%
Applied egg-rr74.1%
Taylor expanded in u1 around 0 76.4%
Taylor expanded in u2 around 0 66.6%
Final simplification66.6%
herbie shell --seed 2024075
(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))))