
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log (- 1.0 u1)))) (sin (* (* 2.0 PI) u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-logf((1.0f - u1))) * sinf(((2.0f * ((float) M_PI)) * u2));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log(Float32(Float32(1.0) - u1)))) * sin(Float32(Float32(Float32(2.0) * Float32(pi)) * u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-log((single(1.0) - u1))) * sin(((single(2.0) * single(pi)) * u2)); end
\begin{array}{l}
\\
\sqrt{-\log \left(1 - u1\right)} \cdot \sin \left(\left(2 \cdot \pi\right) \cdot u2\right)
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 10 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log (- 1.0 u1)))) (sin (* (* 2.0 PI) u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-logf((1.0f - u1))) * sinf(((2.0f * ((float) M_PI)) * u2));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log(Float32(Float32(1.0) - u1)))) * sin(Float32(Float32(Float32(2.0) * Float32(pi)) * u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-log((single(1.0) - u1))) * sin(((single(2.0) * single(pi)) * u2)); end
\begin{array}{l}
\\
\sqrt{-\log \left(1 - u1\right)} \cdot \sin \left(\left(2 \cdot \pi\right) \cdot u2\right)
\end{array}
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) (expm1 (log1p (sin (* (* u2 2.0) PI))))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * expm1f(log1pf(sinf(((u2 * 2.0f) * ((float) M_PI)))));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * expm1(log1p(sin(Float32(Float32(u2 * Float32(2.0)) * Float32(pi)))))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \mathsf{expm1}\left(\mathsf{log1p}\left(\sin \left(\left(u2 \cdot 2\right) \cdot \pi\right)\right)\right)
\end{array}
Initial program 60.7%
sub-neg60.7%
log1p-define98.4%
Simplified98.4%
expm1-log1p-u98.4%
*-commutative98.4%
associate-*r*98.4%
Applied egg-rr98.4%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) (sin (* u2 (* 2.0 PI)))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * sinf((u2 * (2.0f * ((float) M_PI))));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * sin(Float32(u2 * Float32(Float32(2.0) * Float32(pi))))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(u2 \cdot \left(2 \cdot \pi\right)\right)
\end{array}
Initial program 60.7%
sub-neg60.7%
log1p-define98.4%
Simplified98.4%
Final simplification98.4%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(if (<= (- 1.0 u1) 0.9686499834060669)
(* (sqrt (- (log1p (- u1)))) (* 2.0 (* u2 PI)))
(*
(sin (* u2 (* 2.0 PI)))
(sqrt (* u1 (+ 1.0 (* u1 (+ 0.5 (* u1 0.3333333333333333)))))))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if ((1.0f - u1) <= 0.9686499834060669f) {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (u2 * ((float) M_PI)));
} else {
tmp = sinf((u2 * (2.0f * ((float) M_PI)))) * sqrtf((u1 * (1.0f + (u1 * (0.5f + (u1 * 0.3333333333333333f))))));
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (Float32(Float32(1.0) - u1) <= Float32(0.9686499834060669)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(u2 * Float32(pi)))); else tmp = Float32(sin(Float32(u2 * Float32(Float32(2.0) * Float32(pi)))) * 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}
\mathbf{if}\;1 - u1 \leq 0.9686499834060669:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(u2 \cdot \pi\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sin \left(u2 \cdot \left(2 \cdot \pi\right)\right) \cdot \sqrt{u1 \cdot \left(1 + u1 \cdot \left(0.5 + u1 \cdot 0.3333333333333333\right)\right)}\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u1) < 0.968649983Initial program 97.6%
sub-neg97.6%
log1p-define98.5%
Simplified98.5%
add-cbrt-cube98.5%
add-cbrt-cube98.4%
cbrt-unprod98.4%
pow398.4%
pow398.3%
Applied egg-rr98.3%
Taylor expanded in u2 around 0 81.3%
if 0.968649983 < (-.f32 #s(literal 1 binary32) u1) Initial program 54.0%
Taylor expanded in u1 around 0 97.9%
*-commutative97.9%
Simplified97.9%
Final simplification95.4%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* 2.0 PI))))
(if (<= t_0 0.0035000001080334187)
(* (sqrt (- (log1p (- u1)))) (* 2.0 (* u2 PI)))
(* (sin t_0) (sqrt (* u1 (+ 1.0 (* u1 0.5))))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = u2 * (2.0f * ((float) M_PI));
float tmp;
if (t_0 <= 0.0035000001080334187f) {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (u2 * ((float) M_PI)));
} else {
tmp = sinf(t_0) * sqrtf((u1 * (1.0f + (u1 * 0.5f))));
}
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(0.0035000001080334187)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(u2 * Float32(pi)))); else tmp = Float32(sin(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(2 \cdot \pi\right)\\
\mathbf{if}\;t\_0 \leq 0.0035000001080334187:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(u2 \cdot \pi\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sin 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) < 0.00350000011Initial program 57.8%
sub-neg57.8%
log1p-define98.6%
Simplified98.6%
add-cbrt-cube98.6%
add-cbrt-cube98.6%
cbrt-unprod98.7%
pow398.7%
pow398.6%
Applied egg-rr98.6%
Taylor expanded in u2 around 0 97.6%
if 0.00350000011 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 66.8%
Taylor expanded in u1 around 0 84.9%
*-commutative84.9%
Simplified84.9%
Final simplification93.5%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* u2 (* 2.0 PI))) (sqrt (* u1 (+ 1.0 (* u1 (+ 0.5 (* u1 (+ 0.3333333333333333 (* u1 0.25))))))))))
float code(float cosTheta_i, float u1, float u2) {
return sinf((u2 * (2.0f * ((float) M_PI)))) * sqrtf((u1 * (1.0f + (u1 * (0.5f + (u1 * (0.3333333333333333f + (u1 * 0.25f))))))));
}
function code(cosTheta_i, u1, u2) return Float32(sin(Float32(u2 * Float32(Float32(2.0) * Float32(pi)))) * 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 = sin((u2 * (single(2.0) * single(pi)))) * sqrt((u1 * (single(1.0) + (u1 * (single(0.5) + (u1 * (single(0.3333333333333333) + (u1 * single(0.25))))))))); end
\begin{array}{l}
\\
\sin \left(u2 \cdot \left(2 \cdot \pi\right)\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 60.7%
Taylor expanded in u1 around 0 94.0%
*-commutative94.0%
Simplified94.0%
Final simplification94.0%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* 2.0 PI))))
(if (<= t_0 0.01600000075995922)
(* (sqrt (- (log1p (- u1)))) (* 2.0 (* u2 PI)))
(* (sin 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 <= 0.01600000075995922f) {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (u2 * ((float) M_PI)));
} else {
tmp = sinf(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(0.01600000075995922)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(u2 * Float32(pi)))); else tmp = Float32(sin(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 0.01600000075995922:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(u2 \cdot \pi\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sin t\_0 \cdot \sqrt{u1}\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 0.0160000008Initial program 59.8%
sub-neg59.8%
log1p-define98.6%
Simplified98.6%
add-cbrt-cube98.6%
add-cbrt-cube98.6%
cbrt-unprod98.6%
pow398.6%
pow398.5%
Applied egg-rr98.5%
Taylor expanded in u2 around 0 95.5%
if 0.0160000008 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 63.6%
Taylor expanded in u1 around 0 73.4%
Final simplification90.2%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* 2.0 PI))))
(if (<= t_0 0.01600000075995922)
(* 2.0 (* (* u2 PI) (sqrt (* u1 (+ 1.0 (* u1 0.5))))))
(* (sin 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 <= 0.01600000075995922f) {
tmp = 2.0f * ((u2 * ((float) M_PI)) * sqrtf((u1 * (1.0f + (u1 * 0.5f)))));
} else {
tmp = sinf(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(0.01600000075995922)) tmp = Float32(Float32(2.0) * Float32(Float32(u2 * Float32(pi)) * sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(u1 * Float32(0.5))))))); else tmp = Float32(sin(t_0) * sqrt(u1)); end return tmp end
function tmp_2 = code(cosTheta_i, u1, u2) t_0 = u2 * (single(2.0) * single(pi)); tmp = single(0.0); if (t_0 <= single(0.01600000075995922)) tmp = single(2.0) * ((u2 * single(pi)) * sqrt((u1 * (single(1.0) + (u1 * single(0.5)))))); else tmp = sin(t_0) * sqrt(u1); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := u2 \cdot \left(2 \cdot \pi\right)\\
\mathbf{if}\;t\_0 \leq 0.01600000075995922:\\
\;\;\;\;2 \cdot \left(\left(u2 \cdot \pi\right) \cdot \sqrt{u1 \cdot \left(1 + u1 \cdot 0.5\right)}\right)\\
\mathbf{else}:\\
\;\;\;\;\sin t\_0 \cdot \sqrt{u1}\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 0.0160000008Initial program 59.8%
sub-neg59.8%
log1p-define98.6%
Simplified98.6%
expm1-log1p-u98.6%
*-commutative98.6%
associate-*r*98.6%
Applied egg-rr98.6%
Taylor expanded in u1 around 0 89.0%
*-commutative89.0%
Simplified89.0%
Taylor expanded in u2 around 0 87.4%
if 0.0160000008 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 63.6%
Taylor expanded in u1 around 0 73.4%
Final simplification84.0%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* 2.0 (* (* u2 PI) (sqrt (* u1 (+ 1.0 (* u1 0.5)))))))
float code(float cosTheta_i, float u1, float u2) {
return 2.0f * ((u2 * ((float) M_PI)) * sqrtf((u1 * (1.0f + (u1 * 0.5f)))));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(2.0) * Float32(Float32(u2 * Float32(pi)) * sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(u1 * Float32(0.5))))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(2.0) * ((u2 * single(pi)) * sqrt((u1 * (single(1.0) + (u1 * single(0.5)))))); end
\begin{array}{l}
\\
2 \cdot \left(\left(u2 \cdot \pi\right) \cdot \sqrt{u1 \cdot \left(1 + u1 \cdot 0.5\right)}\right)
\end{array}
Initial program 60.7%
sub-neg60.7%
log1p-define98.4%
Simplified98.4%
expm1-log1p-u98.4%
*-commutative98.4%
associate-*r*98.4%
Applied egg-rr98.4%
Taylor expanded in u1 around 0 88.3%
*-commutative88.3%
Simplified88.3%
Taylor expanded in u2 around 0 77.1%
Final simplification77.1%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* 2.0 (* (* u2 PI) (sqrt u1))))
float code(float cosTheta_i, float u1, float u2) {
return 2.0f * ((u2 * ((float) M_PI)) * sqrtf(u1));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(2.0) * Float32(Float32(u2 * Float32(pi)) * sqrt(u1))) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(2.0) * ((u2 * single(pi)) * sqrt(u1)); end
\begin{array}{l}
\\
2 \cdot \left(\left(u2 \cdot \pi\right) \cdot \sqrt{u1}\right)
\end{array}
Initial program 60.7%
Taylor expanded in u1 around 0 75.6%
Taylor expanded in u2 around 0 68.1%
Final simplification68.1%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* 2.0 (* u2 (* PI (sqrt u1)))))
float code(float cosTheta_i, float u1, float u2) {
return 2.0f * (u2 * (((float) M_PI) * sqrtf(u1)));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(2.0) * Float32(u2 * Float32(Float32(pi) * sqrt(u1)))) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(2.0) * (u2 * (single(pi) * sqrt(u1))); end
\begin{array}{l}
\\
2 \cdot \left(u2 \cdot \left(\pi \cdot \sqrt{u1}\right)\right)
\end{array}
Initial program 60.7%
sub-neg60.7%
log1p-define98.4%
Simplified98.4%
log1p-undefine60.7%
sub-neg60.7%
add-sqr-sqrt60.6%
pow260.6%
Applied egg-rr73.2%
Taylor expanded in u2 around 0 40.6%
associate-*l*40.6%
log1p-define66.1%
Simplified66.1%
Taylor expanded in u1 around 0 68.1%
Final simplification68.1%
herbie shell --seed 2024137
(FPCore (cosTheta_i u1 u2)
:name "Beckmann Sample, near normal, slope_y"
: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)))) (sin (* (* 2.0 PI) u2))))