
(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}
Herbie found 9 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 (* (+ PI PI) u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * sinf(((((float) M_PI) + ((float) M_PI)) * u2));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * sin(Float32(Float32(Float32(pi) + Float32(pi)) * u2))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(\left(\pi + \pi\right) \cdot u2\right)
\end{array}
Initial program 57.9%
lift-log.f32N/A
lift--.f32N/A
sub-flipN/A
lower-log1p.f32N/A
lower-neg.f3298.4
Applied rewrites98.4%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
count-2-revN/A
rem-3cbrt-rftN/A
cbrt-unprodN/A
sqr-abs-revN/A
lift-fabs.f32N/A
lift-fabs.f32N/A
cbrt-unprodN/A
lift-cbrt.f32N/A
lift-cbrt.f32N/A
associate-*l*N/A
lift-cbrt.f32N/A
cbrt-prodN/A
lift-*.f32N/A
lift-cbrt.f32N/A
Applied rewrites98.4%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (log (- 1.0 u1))))
(if (<= t_0 -0.0024999999441206455)
(* (sqrt (- t_0)) (sin (* (+ PI PI) u2)))
(* (sqrt (* (fma 0.5 u1 1.0) u1)) (sin (* u2 (+ PI PI)))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = logf((1.0f - u1));
float tmp;
if (t_0 <= -0.0024999999441206455f) {
tmp = sqrtf(-t_0) * sinf(((((float) M_PI) + ((float) M_PI)) * u2));
} else {
tmp = sqrtf((fmaf(0.5f, u1, 1.0f) * u1)) * sinf((u2 * (((float) M_PI) + ((float) M_PI))));
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = log(Float32(Float32(1.0) - u1)) tmp = Float32(0.0) if (t_0 <= Float32(-0.0024999999441206455)) tmp = Float32(sqrt(Float32(-t_0)) * sin(Float32(Float32(Float32(pi) + Float32(pi)) * u2))); else tmp = Float32(sqrt(Float32(fma(Float32(0.5), u1, Float32(1.0)) * u1)) * sin(Float32(u2 * Float32(Float32(pi) + Float32(pi))))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \log \left(1 - u1\right)\\
\mathbf{if}\;t\_0 \leq -0.0024999999441206455:\\
\;\;\;\;\sqrt{-t\_0} \cdot \sin \left(\left(\pi + \pi\right) \cdot u2\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\mathsf{fma}\left(0.5, u1, 1\right) \cdot u1} \cdot \sin \left(u2 \cdot \left(\pi + \pi\right)\right)\\
\end{array}
\end{array}
if (log.f32 (-.f32 #s(literal 1 binary32) u1)) < -0.00249999994Initial program 57.9%
lift-*.f32N/A
count-2-revN/A
lower-+.f3257.9
Applied rewrites57.9%
if -0.00249999994 < (log.f32 (-.f32 #s(literal 1 binary32) u1)) Initial program 57.9%
Taylor expanded in u1 around 0
lower-*.f32N/A
lower-+.f32N/A
lower-*.f3287.8
Applied rewrites87.8%
lift-*.f32N/A
*-commutativeN/A
lower-*.f3287.8
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
lower-fma.f3287.8
lower-fma.f32N/A
lower-fma.f32N/A
lower-fma.f32N/A
lower-fma.f32N/A
lower-fma.f32N/A
lower-fma.f32N/A
Applied rewrites87.8%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (log (- 1.0 u1))))
(if (<= t_0 -0.004999999888241291)
(*
(sqrt (- t_0))
(fma
PI
u2
(fma
u2
PI
(* (* (* (* (* u2 u2) -1.3333333333333333) u2) PI) (* PI PI)))))
(* (sqrt (* (fma 0.5 u1 1.0) u1)) (sin (* u2 (+ PI PI)))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = logf((1.0f - u1));
float tmp;
if (t_0 <= -0.004999999888241291f) {
tmp = sqrtf(-t_0) * fmaf(((float) M_PI), u2, fmaf(u2, ((float) M_PI), (((((u2 * u2) * -1.3333333333333333f) * u2) * ((float) M_PI)) * (((float) M_PI) * ((float) M_PI)))));
} else {
tmp = sqrtf((fmaf(0.5f, u1, 1.0f) * u1)) * sinf((u2 * (((float) M_PI) + ((float) M_PI))));
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = log(Float32(Float32(1.0) - u1)) tmp = Float32(0.0) if (t_0 <= Float32(-0.004999999888241291)) tmp = Float32(sqrt(Float32(-t_0)) * fma(Float32(pi), u2, fma(u2, Float32(pi), Float32(Float32(Float32(Float32(Float32(u2 * u2) * Float32(-1.3333333333333333)) * u2) * Float32(pi)) * Float32(Float32(pi) * Float32(pi)))))); else tmp = Float32(sqrt(Float32(fma(Float32(0.5), u1, Float32(1.0)) * u1)) * sin(Float32(u2 * Float32(Float32(pi) + Float32(pi))))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \log \left(1 - u1\right)\\
\mathbf{if}\;t\_0 \leq -0.004999999888241291:\\
\;\;\;\;\sqrt{-t\_0} \cdot \mathsf{fma}\left(\pi, u2, \mathsf{fma}\left(u2, \pi, \left(\left(\left(\left(u2 \cdot u2\right) \cdot -1.3333333333333333\right) \cdot u2\right) \cdot \pi\right) \cdot \left(\pi \cdot \pi\right)\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\mathsf{fma}\left(0.5, u1, 1\right) \cdot u1} \cdot \sin \left(u2 \cdot \left(\pi + \pi\right)\right)\\
\end{array}
\end{array}
if (log.f32 (-.f32 #s(literal 1 binary32) u1)) < -0.00499999989Initial program 57.9%
Taylor expanded in u2 around 0
lower-*.f32N/A
lower-fma.f32N/A
lower-*.f32N/A
lower-pow.f32N/A
lower-pow.f32N/A
lower-PI.f32N/A
lower-*.f32N/A
lower-PI.f3253.6
Applied rewrites53.6%
lift-*.f32N/A
lift-fma.f32N/A
+-commutativeN/A
distribute-lft-inN/A
lift-*.f32N/A
count-2-revN/A
distribute-lft-inN/A
associate-+l+N/A
*-commutativeN/A
lower-fma.f32N/A
lower-fma.f32N/A
lift-*.f32N/A
associate-*r*N/A
associate-*r*N/A
Applied rewrites53.6%
if -0.00499999989 < (log.f32 (-.f32 #s(literal 1 binary32) u1)) Initial program 57.9%
Taylor expanded in u1 around 0
lower-*.f32N/A
lower-+.f32N/A
lower-*.f3287.8
Applied rewrites87.8%
lift-*.f32N/A
*-commutativeN/A
lower-*.f3287.8
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
lower-fma.f3287.8
lower-fma.f32N/A
lower-fma.f32N/A
lower-fma.f32N/A
lower-fma.f32N/A
lower-fma.f32N/A
lower-fma.f32N/A
Applied rewrites87.8%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= u2 0.0024999999441206455) (* (sqrt (- (log1p (- u1)))) (* 2.0 (* u2 PI))) (* (sqrt u1) (sin (* (+ PI PI) u2)))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if (u2 <= 0.0024999999441206455f) {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (u2 * ((float) M_PI)));
} else {
tmp = sqrtf(u1) * sinf(((((float) M_PI) + ((float) M_PI)) * u2));
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (u2 <= Float32(0.0024999999441206455)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(u2 * Float32(pi)))); else tmp = Float32(sqrt(u1) * sin(Float32(Float32(Float32(pi) + Float32(pi)) * u2))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u2 \leq 0.0024999999441206455:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(u2 \cdot \pi\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1} \cdot \sin \left(\left(\pi + \pi\right) \cdot u2\right)\\
\end{array}
\end{array}
if u2 < 0.00249999994Initial program 57.9%
lift-log.f32N/A
lift--.f32N/A
sub-flipN/A
lower-log1p.f32N/A
lower-neg.f3298.4
Applied rewrites98.4%
Taylor expanded in u2 around 0
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f3281.6
Applied rewrites81.6%
if 0.00249999994 < u2 Initial program 57.9%
lift-log.f32N/A
lift--.f32N/A
sub-flipN/A
lower-log1p.f32N/A
lower-neg.f3298.4
Applied rewrites98.4%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
count-2-revN/A
rem-3cbrt-rftN/A
cbrt-unprodN/A
sqr-abs-revN/A
lift-fabs.f32N/A
lift-fabs.f32N/A
cbrt-unprodN/A
lift-cbrt.f32N/A
lift-cbrt.f32N/A
associate-*l*N/A
lift-cbrt.f32N/A
cbrt-prodN/A
lift-*.f32N/A
lift-cbrt.f32N/A
Applied rewrites98.4%
Taylor expanded in u1 around 0
Applied rewrites76.4%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) (* 2.0 (* u2 PI))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * (2.0f * (u2 * ((float) M_PI)));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(u2 * Float32(pi)))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(u2 \cdot \pi\right)\right)
\end{array}
Initial program 57.9%
lift-log.f32N/A
lift--.f32N/A
sub-flipN/A
lower-log1p.f32N/A
lower-neg.f3298.4
Applied rewrites98.4%
Taylor expanded in u2 around 0
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f3281.6
Applied rewrites81.6%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= u1 0.002899999963119626) (* (sqrt (* u1 (+ 1.0 (* 0.5 u1)))) (* 2.0 (* u2 PI))) (* (* (sqrt (- (log (- 1.0 u1)))) (+ PI PI)) u2)))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if (u1 <= 0.002899999963119626f) {
tmp = sqrtf((u1 * (1.0f + (0.5f * u1)))) * (2.0f * (u2 * ((float) M_PI)));
} else {
tmp = (sqrtf(-logf((1.0f - u1))) * (((float) M_PI) + ((float) M_PI))) * u2;
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (u1 <= Float32(0.002899999963119626)) tmp = Float32(sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(Float32(0.5) * u1)))) * Float32(Float32(2.0) * Float32(u2 * Float32(pi)))); else tmp = Float32(Float32(sqrt(Float32(-log(Float32(Float32(1.0) - u1)))) * Float32(Float32(pi) + Float32(pi))) * u2); end return tmp end
function tmp_2 = code(cosTheta_i, u1, u2) tmp = single(0.0); if (u1 <= single(0.002899999963119626)) tmp = sqrt((u1 * (single(1.0) + (single(0.5) * u1)))) * (single(2.0) * (u2 * single(pi))); else tmp = (sqrt(-log((single(1.0) - u1))) * (single(pi) + single(pi))) * u2; end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u1 \leq 0.002899999963119626:\\
\;\;\;\;\sqrt{u1 \cdot \left(1 + 0.5 \cdot u1\right)} \cdot \left(2 \cdot \left(u2 \cdot \pi\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\left(\sqrt{-\log \left(1 - u1\right)} \cdot \left(\pi + \pi\right)\right) \cdot u2\\
\end{array}
\end{array}
if u1 < 0.00289999996Initial program 57.9%
Taylor expanded in u1 around 0
lower-*.f32N/A
lower-+.f32N/A
lower-*.f3287.8
Applied rewrites87.8%
Taylor expanded in u2 around 0
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f3274.4
Applied rewrites74.4%
if 0.00289999996 < u1 Initial program 57.9%
Taylor expanded in u2 around 0
lower-*.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-sqrt.f32N/A
lower-neg.f32N/A
lower-log.f32N/A
lower--.f3250.7
Applied rewrites50.7%
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
count-2-revN/A
lift-*.f32N/A
lift-*.f32N/A
distribute-rgt-outN/A
count-2-revN/A
lift-*.f32N/A
lower-*.f3250.7
lift-*.f32N/A
count-2-revN/A
lower-+.f3250.7
Applied rewrites50.7%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (* u1 (+ 1.0 (* 0.5 u1)))) (* 2.0 (* u2 PI))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((u1 * (1.0f + (0.5f * u1)))) * (2.0f * (u2 * ((float) M_PI)));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(Float32(0.5) * u1)))) * Float32(Float32(2.0) * Float32(u2 * Float32(pi)))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt((u1 * (single(1.0) + (single(0.5) * u1)))) * (single(2.0) * (u2 * single(pi))); end
\begin{array}{l}
\\
\sqrt{u1 \cdot \left(1 + 0.5 \cdot u1\right)} \cdot \left(2 \cdot \left(u2 \cdot \pi\right)\right)
\end{array}
Initial program 57.9%
Taylor expanded in u1 around 0
lower-*.f32N/A
lower-+.f32N/A
lower-*.f3287.8
Applied rewrites87.8%
Taylor expanded in u2 around 0
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f3274.4
Applied rewrites74.4%
(FPCore (cosTheta_i u1 u2) :precision binary32 (/ (* (* (* (sqrt u1) PI) u2) 18.0) 9.0))
float code(float cosTheta_i, float u1, float u2) {
return (((sqrtf(u1) * ((float) M_PI)) * u2) * 18.0f) / 9.0f;
}
function code(cosTheta_i, u1, u2) return Float32(Float32(Float32(Float32(sqrt(u1) * Float32(pi)) * u2) * Float32(18.0)) / Float32(9.0)) end
function tmp = code(cosTheta_i, u1, u2) tmp = (((sqrt(u1) * single(pi)) * u2) * single(18.0)) / single(9.0); end
\begin{array}{l}
\\
\frac{\left(\left(\sqrt{u1} \cdot \pi\right) \cdot u2\right) \cdot 18}{9}
\end{array}
Initial program 57.9%
Taylor expanded in u2 around 0
lower-*.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-sqrt.f32N/A
lower-neg.f32N/A
lower-log.f32N/A
lower--.f3250.7
Applied rewrites50.7%
Taylor expanded in u1 around 0
lower-*.f32N/A
lower-PI.f32N/A
lower-sqrt.f3266.5
Applied rewrites66.5%
lift-*.f32N/A
*-commutativeN/A
metadata-evalN/A
metadata-evalN/A
metadata-evalN/A
frac-addN/A
associate-*r/N/A
lower-/.f32N/A
Applied rewrites66.5%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (+ u2 u2) (* (sqrt u1) PI)))
float code(float cosTheta_i, float u1, float u2) {
return (u2 + u2) * (sqrtf(u1) * ((float) M_PI));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(u2 + u2) * Float32(sqrt(u1) * Float32(pi))) end
function tmp = code(cosTheta_i, u1, u2) tmp = (u2 + u2) * (sqrt(u1) * single(pi)); end
\begin{array}{l}
\\
\left(u2 + u2\right) \cdot \left(\sqrt{u1} \cdot \pi\right)
\end{array}
Initial program 57.9%
Taylor expanded in u2 around 0
lower-*.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-sqrt.f32N/A
lower-neg.f32N/A
lower-log.f32N/A
lower--.f3250.7
Applied rewrites50.7%
Taylor expanded in u1 around 0
lower-*.f32N/A
lower-PI.f32N/A
lower-sqrt.f3266.5
Applied rewrites66.5%
lift-*.f32N/A
lift-*.f32N/A
associate-*r*N/A
lower-*.f32N/A
count-2-revN/A
lower-+.f3266.5
lift-*.f32N/A
*-commutativeN/A
lower-*.f3266.5
Applied rewrites66.5%
herbie shell --seed 2025156
(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))))