
(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 8 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)))) (sin (* (* 2.0 PI) u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * sinf(((2.0f * ((float) M_PI)) * u2));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * sin(Float32(Float32(Float32(2.0) * Float32(pi)) * u2))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(\left(2 \cdot \pi\right) \cdot u2\right)
\end{array}
Initial program 58.3%
sub-neg58.3%
log1p-define98.3%
Simplified98.3%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.0006699999794363976)
(* (sqrt (- (log1p (- u1)))) (* 2.0 (* PI u2)))
(*
(sin t_0)
(sqrt
(*
u1
(+ 1.0 (* u1 (+ 0.5 (* u1 (- 0.3333333333333333 (* u1 -0.25))))))))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = (2.0f * ((float) M_PI)) * u2;
float tmp;
if (t_0 <= 0.0006699999794363976f) {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (((float) M_PI) * u2));
} else {
tmp = sinf(t_0) * sqrtf((u1 * (1.0f + (u1 * (0.5f + (u1 * (0.3333333333333333f - (u1 * -0.25f))))))));
}
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(0.0006699999794363976)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(Float32(pi) * u2))); else tmp = Float32(sin(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)))))))))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.0006699999794363976:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(\pi \cdot u2\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sin 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)}\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 6.6999998e-4Initial program 61.5%
sub-neg61.5%
log1p-define98.8%
Simplified98.8%
expm1-log1p-u98.8%
*-commutative98.8%
associate-*r*98.8%
Applied egg-rr98.8%
expm1-undefine41.8%
log1p-undefine41.8%
rem-exp-log41.8%
*-commutative41.8%
associate-*r*41.8%
+-commutative41.8%
associate-*r*41.8%
*-commutative41.8%
*-commutative41.8%
Applied egg-rr41.8%
Taylor expanded in u2 around 0 98.8%
if 6.6999998e-4 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 54.5%
Taylor expanded in u1 around 0 93.3%
Final simplification96.3%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.0006699999794363976)
(* (sqrt (- (log1p (- u1)))) (* 2.0 (* PI u2)))
(*
(sin 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 <= 0.0006699999794363976f) {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (((float) M_PI) * u2));
} else {
tmp = sinf(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(0.0006699999794363976)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(Float32(pi) * u2))); else tmp = Float32(sin(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 0.0006699999794363976:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(\pi \cdot u2\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sin 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) < 6.6999998e-4Initial program 61.5%
sub-neg61.5%
log1p-define98.8%
Simplified98.8%
expm1-log1p-u98.8%
*-commutative98.8%
associate-*r*98.8%
Applied egg-rr98.8%
expm1-undefine41.8%
log1p-undefine41.8%
rem-exp-log41.8%
*-commutative41.8%
associate-*r*41.8%
+-commutative41.8%
associate-*r*41.8%
*-commutative41.8%
*-commutative41.8%
Applied egg-rr41.8%
Taylor expanded in u2 around 0 98.8%
if 6.6999998e-4 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 54.5%
Taylor expanded in u1 around 0 91.9%
Final simplification95.6%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.0006699999794363976)
(* (sqrt (- (log1p (- u1)))) (* 2.0 (* PI u2)))
(* (sin 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 <= 0.0006699999794363976f) {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (((float) M_PI) * u2));
} else {
tmp = sinf(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(0.0006699999794363976)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(Float32(pi) * u2))); 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 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.0006699999794363976:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(\pi \cdot u2\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) < 6.6999998e-4Initial program 61.5%
sub-neg61.5%
log1p-define98.8%
Simplified98.8%
expm1-log1p-u98.8%
*-commutative98.8%
associate-*r*98.8%
Applied egg-rr98.8%
expm1-undefine41.8%
log1p-undefine41.8%
rem-exp-log41.8%
*-commutative41.8%
associate-*r*41.8%
+-commutative41.8%
associate-*r*41.8%
*-commutative41.8%
*-commutative41.8%
Applied egg-rr41.8%
Taylor expanded in u2 around 0 98.8%
if 6.6999998e-4 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 54.5%
Taylor expanded in u1 around 0 88.9%
Final simplification94.3%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.00860000029206276)
(* (sqrt (- (log1p (- u1)))) (* 2.0 (* PI u2)))
(* (sin 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 <= 0.00860000029206276f) {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (((float) M_PI) * u2));
} else {
tmp = sinf(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(0.00860000029206276)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(Float32(pi) * u2))); else tmp = Float32(sin(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 0.00860000029206276:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(\pi \cdot u2\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sin t\_0 \cdot \sqrt{u1}\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 0.00860000029Initial program 60.0%
sub-neg60.0%
log1p-define98.7%
Simplified98.7%
expm1-log1p-u98.7%
*-commutative98.7%
associate-*r*98.7%
Applied egg-rr98.7%
expm1-undefine47.9%
log1p-undefine47.9%
rem-exp-log47.9%
*-commutative47.9%
associate-*r*47.9%
+-commutative47.9%
associate-*r*47.9%
*-commutative47.9%
*-commutative47.9%
Applied egg-rr47.9%
Taylor expanded in u2 around 0 96.9%
if 0.00860000029 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 55.2%
sub-neg55.2%
log1p-define97.6%
Simplified97.6%
pow1/297.6%
log1p-undefine55.2%
sub-neg55.2%
pow-to-exp55.1%
add-sqr-sqrt55.2%
sqrt-unprod55.1%
sqr-neg55.1%
sqrt-unprod1.7%
add-sqr-sqrt1.7%
sub-neg1.7%
log1p-undefine-0.0%
add-sqr-sqrt-0.0%
sqrt-unprod74.2%
sqr-neg74.2%
sqrt-unprod74.2%
add-sqr-sqrt74.2%
Applied egg-rr74.2%
Taylor expanded in u1 around 0 77.4%
Final simplification90.1%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* (* 2.0 PI) u2)) (sqrt u1)))
float code(float cosTheta_i, float u1, float u2) {
return sinf(((2.0f * ((float) M_PI)) * u2)) * sqrtf(u1);
}
function code(cosTheta_i, u1, u2) return Float32(sin(Float32(Float32(Float32(2.0) * Float32(pi)) * u2)) * sqrt(u1)) end
function tmp = code(cosTheta_i, u1, u2) tmp = sin(((single(2.0) * single(pi)) * u2)) * sqrt(u1); end
\begin{array}{l}
\\
\sin \left(\left(2 \cdot \pi\right) \cdot u2\right) \cdot \sqrt{u1}
\end{array}
Initial program 58.3%
sub-neg58.3%
log1p-define98.3%
Simplified98.3%
pow1/298.3%
log1p-undefine58.3%
sub-neg58.3%
pow-to-exp58.3%
add-sqr-sqrt58.3%
sqrt-unprod58.3%
sqr-neg58.3%
sqrt-unprod1.6%
add-sqr-sqrt1.6%
sub-neg1.6%
log1p-undefine-0.0%
add-sqr-sqrt-0.0%
sqrt-unprod72.2%
sqr-neg72.2%
sqrt-unprod72.2%
add-sqr-sqrt72.2%
Applied egg-rr72.2%
Taylor expanded in u1 around 0 75.4%
Final simplification75.4%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* PI (* u2 (sqrt (* u1 4.0)))))
float code(float cosTheta_i, float u1, float u2) {
return ((float) M_PI) * (u2 * sqrtf((u1 * 4.0f)));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(pi) * Float32(u2 * sqrt(Float32(u1 * Float32(4.0))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(pi) * (u2 * sqrt((u1 * single(4.0)))); end
\begin{array}{l}
\\
\pi \cdot \left(u2 \cdot \sqrt{u1 \cdot 4}\right)
\end{array}
Initial program 58.3%
Taylor expanded in u1 around 0 -0.0%
associate-*r*-0.0%
unpow2-0.0%
rem-square-sqrt4.0%
*-commutative4.0%
associate-*l*4.0%
*-commutative4.0%
mul-1-neg4.0%
Simplified4.0%
Taylor expanded in u2 around 0 4.6%
associate-*r*4.6%
*-commutative4.6%
*-commutative4.6%
*-commutative4.6%
*-commutative4.6%
Simplified4.6%
pow14.6%
*-commutative4.6%
associate-*l*4.6%
add-sqr-sqrt-0.0%
sqrt-unprod62.8%
swap-sqr62.8%
add-sqr-sqrt62.8%
metadata-eval62.8%
Applied egg-rr62.8%
Simplified62.8%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* 2.0 (* (* PI u2) (sqrt u1))))
float code(float cosTheta_i, float u1, float u2) {
return 2.0f * ((((float) M_PI) * u2) * sqrtf(u1));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(2.0) * Float32(Float32(Float32(pi) * u2) * sqrt(u1))) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(2.0) * ((single(pi) * u2) * sqrt(u1)); end
\begin{array}{l}
\\
2 \cdot \left(\left(\pi \cdot u2\right) \cdot \sqrt{u1}\right)
\end{array}
Initial program 58.3%
Taylor expanded in u1 around 0 -0.0%
associate-*r*-0.0%
unpow2-0.0%
rem-square-sqrt4.0%
*-commutative4.0%
associate-*l*4.0%
*-commutative4.0%
mul-1-neg4.0%
Simplified4.0%
Taylor expanded in u2 around 0 4.6%
associate-*r*4.6%
*-commutative4.6%
*-commutative4.6%
*-commutative4.6%
*-commutative4.6%
Simplified4.6%
pow14.6%
*-commutative4.6%
associate-*l*4.6%
add-sqr-sqrt-0.0%
sqrt-unprod62.8%
swap-sqr62.8%
add-sqr-sqrt62.8%
metadata-eval62.8%
Applied egg-rr62.8%
Simplified62.8%
Taylor expanded in u2 around 0 62.8%
Final simplification62.8%
herbie shell --seed 2024107
(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))))