
(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 12 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 (* (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 55.8%
sub-neg55.8%
log1p-define99.0%
Simplified99.0%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.0014199999859556556)
(* (sqrt (- (log1p (- u1)))) 1.0)
(*
(sqrt
(-
(*
u1
(- (* u1 (- (* u1 (- (* -0.25 u1) 0.3333333333333333)) 0.5)) 1.0))))
(cos t_0)))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = (2.0f * ((float) M_PI)) * u2;
float tmp;
if (t_0 <= 0.0014199999859556556f) {
tmp = sqrtf(-log1pf(-u1)) * 1.0f;
} else {
tmp = sqrtf(-(u1 * ((u1 * ((u1 * ((-0.25f * u1) - 0.3333333333333333f)) - 0.5f)) - 1.0f))) * cosf(t_0);
}
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(0.0014199999859556556)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(1.0)); else tmp = Float32(sqrt(Float32(-Float32(u1 * Float32(Float32(u1 * Float32(Float32(u1 * Float32(Float32(Float32(-0.25) * u1) - Float32(0.3333333333333333))) - Float32(0.5))) - Float32(1.0))))) * cos(t_0)); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.0014199999859556556:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot 1\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-u1 \cdot \left(u1 \cdot \left(u1 \cdot \left(-0.25 \cdot u1 - 0.3333333333333333\right) - 0.5\right) - 1\right)} \cdot \cos t\_0\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 0.00141999999Initial program 59.4%
sub-neg59.4%
log1p-define99.6%
Simplified99.6%
Taylor expanded in u2 around 0 99.2%
if 0.00141999999 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 50.2%
Taylor expanded in u1 around 0 93.1%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.0014199999859556556)
(* (sqrt (- (log1p (- u1)))) 1.0)
(*
(sqrt (- (* u1 (- (* u1 (- (* -0.3333333333333333 u1) 0.5)) 1.0))))
(cos t_0)))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = (2.0f * ((float) M_PI)) * u2;
float tmp;
if (t_0 <= 0.0014199999859556556f) {
tmp = sqrtf(-log1pf(-u1)) * 1.0f;
} else {
tmp = sqrtf(-(u1 * ((u1 * ((-0.3333333333333333f * u1) - 0.5f)) - 1.0f))) * cosf(t_0);
}
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(0.0014199999859556556)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(1.0)); else tmp = Float32(sqrt(Float32(-Float32(u1 * Float32(Float32(u1 * Float32(Float32(Float32(-0.3333333333333333) * u1) - Float32(0.5))) - Float32(1.0))))) * cos(t_0)); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.0014199999859556556:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot 1\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-u1 \cdot \left(u1 \cdot \left(-0.3333333333333333 \cdot u1 - 0.5\right) - 1\right)} \cdot \cos t\_0\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 0.00141999999Initial program 59.4%
sub-neg59.4%
log1p-define99.6%
Simplified99.6%
Taylor expanded in u2 around 0 99.2%
if 0.00141999999 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 50.2%
Taylor expanded in u1 around 0 91.8%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.0014199999859556556)
(* (sqrt (- (log1p (- u1)))) 1.0)
(* (sqrt (- (* u1 (- (* -0.5 u1) 1.0)))) (cos t_0)))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = (2.0f * ((float) M_PI)) * u2;
float tmp;
if (t_0 <= 0.0014199999859556556f) {
tmp = sqrtf(-log1pf(-u1)) * 1.0f;
} else {
tmp = sqrtf(-(u1 * ((-0.5f * u1) - 1.0f))) * cosf(t_0);
}
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(0.0014199999859556556)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(1.0)); else tmp = Float32(sqrt(Float32(-Float32(u1 * Float32(Float32(Float32(-0.5) * u1) - Float32(1.0))))) * cos(t_0)); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.0014199999859556556:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot 1\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-u1 \cdot \left(-0.5 \cdot u1 - 1\right)} \cdot \cos t\_0\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 0.00141999999Initial program 59.4%
sub-neg59.4%
log1p-define99.6%
Simplified99.6%
Taylor expanded in u2 around 0 99.2%
if 0.00141999999 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 50.2%
Taylor expanded in u1 around 0 89.5%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.0035000001080334187)
(* (sqrt (- (log1p (- u1)))) 1.0)
(* (sqrt u1) (cos t_0)))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = (2.0f * ((float) M_PI)) * u2;
float tmp;
if (t_0 <= 0.0035000001080334187f) {
tmp = sqrtf(-log1pf(-u1)) * 1.0f;
} else {
tmp = sqrtf(u1) * cosf(t_0);
}
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(0.0035000001080334187)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(1.0)); else tmp = Float32(sqrt(u1) * cos(t_0)); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.0035000001080334187:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot 1\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1} \cdot \cos t\_0\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 0.00350000011Initial program 58.7%
sub-neg58.7%
log1p-define99.6%
Simplified99.6%
Taylor expanded in u2 around 0 98.0%
if 0.00350000011 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 50.1%
sub-neg50.1%
log1p-define97.9%
Simplified97.9%
neg-mul-197.9%
log1p-undefine50.1%
sub-neg50.1%
neg-mul-150.1%
pow1/250.1%
add-sqr-sqrt50.1%
sqrt-unprod50.1%
sqr-neg50.1%
sqrt-unprod2.0%
add-sqr-sqrt2.0%
sub-neg2.0%
log1p-undefine-0.0%
add-sqr-sqrt-0.0%
sqrt-unprod79.3%
sqr-neg79.3%
sqrt-unprod79.4%
add-sqr-sqrt79.3%
Applied egg-rr79.3%
Taylor expanded in u1 around 0 81.0%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) 1.0))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * 1.0f;
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(1.0)) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot 1
\end{array}
Initial program 55.8%
sub-neg55.8%
log1p-define99.0%
Simplified99.0%
Taylor expanded in u2 around 0 80.3%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(*
(sqrt
(-
(* u1 (- (* u1 (- (* u1 (- (* -0.25 u1) 0.3333333333333333)) 0.5)) 1.0))))
1.0))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-(u1 * ((u1 * ((u1 * ((-0.25f * u1) - 0.3333333333333333f)) - 0.5f)) - 1.0f))) * 1.0f;
}
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 * ((u1 * ((u1 * (((-0.25e0) * u1) - 0.3333333333333333e0)) - 0.5e0)) - 1.0e0))) * 1.0e0
end function
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-Float32(u1 * Float32(Float32(u1 * Float32(Float32(u1 * Float32(Float32(Float32(-0.25) * u1) - Float32(0.3333333333333333))) - Float32(0.5))) - Float32(1.0))))) * Float32(1.0)) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-(u1 * ((u1 * ((u1 * ((single(-0.25) * u1) - single(0.3333333333333333))) - single(0.5))) - single(1.0)))) * single(1.0); end
\begin{array}{l}
\\
\sqrt{-u1 \cdot \left(u1 \cdot \left(u1 \cdot \left(-0.25 \cdot u1 - 0.3333333333333333\right) - 0.5\right) - 1\right)} \cdot 1
\end{array}
Initial program 55.8%
sub-neg55.8%
log1p-define99.0%
Simplified99.0%
Taylor expanded in u2 around 0 80.3%
Taylor expanded in u1 around 0 76.0%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (* u1 (- (* u1 (- (* -0.3333333333333333 u1) 0.5)) 1.0)))) 1.0))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-(u1 * ((u1 * ((-0.3333333333333333f * u1) - 0.5f)) - 1.0f))) * 1.0f;
}
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 * ((u1 * (((-0.3333333333333333e0) * u1) - 0.5e0)) - 1.0e0))) * 1.0e0
end function
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-Float32(u1 * Float32(Float32(u1 * Float32(Float32(Float32(-0.3333333333333333) * u1) - Float32(0.5))) - Float32(1.0))))) * Float32(1.0)) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-(u1 * ((u1 * ((single(-0.3333333333333333) * u1) - single(0.5))) - single(1.0)))) * single(1.0); end
\begin{array}{l}
\\
\sqrt{-u1 \cdot \left(u1 \cdot \left(-0.3333333333333333 \cdot u1 - 0.5\right) - 1\right)} \cdot 1
\end{array}
Initial program 55.8%
sub-neg55.8%
log1p-define99.0%
Simplified99.0%
Taylor expanded in u2 around 0 80.3%
Taylor expanded in u1 around 0 74.6%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (+ (* u1 (* u1 -0.5)) (* u1 -1.0)))) 1.0))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-((u1 * (u1 * -0.5f)) + (u1 * -1.0f))) * 1.0f;
}
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 * (u1 * (-0.5e0))) + (u1 * (-1.0e0)))) * 1.0e0
end function
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-Float32(Float32(u1 * Float32(u1 * Float32(-0.5))) + Float32(u1 * Float32(-1.0))))) * Float32(1.0)) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-((u1 * (u1 * single(-0.5))) + (u1 * single(-1.0)))) * single(1.0); end
\begin{array}{l}
\\
\sqrt{-\left(u1 \cdot \left(u1 \cdot -0.5\right) + u1 \cdot -1\right)} \cdot 1
\end{array}
Initial program 55.8%
sub-neg55.8%
log1p-define99.0%
Simplified99.0%
Taylor expanded in u2 around 0 80.3%
Taylor expanded in u1 around 0 71.8%
add-sqr-sqrt71.8%
sqrt-unprod71.8%
sqr-neg71.8%
sqrt-unprod-0.0%
add-sqr-sqrt-0.0%
sub-neg-0.0%
distribute-lft-in-0.0%
add-sqr-sqrt-0.0%
sqrt-unprod-0.0%
sqr-neg-0.0%
sqrt-unprod-0.0%
add-sqr-sqrt-0.0%
*-commutative-0.0%
add-sqr-sqrt-0.0%
sqrt-unprod71.9%
sqr-neg71.9%
sqrt-unprod71.8%
add-sqr-sqrt71.9%
metadata-eval71.9%
Applied egg-rr71.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (* u1 (- (* -0.5 u1) 1.0)))) 1.0))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-(u1 * ((-0.5f * u1) - 1.0f))) * 1.0f;
}
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 * (((-0.5e0) * u1) - 1.0e0))) * 1.0e0
end function
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-Float32(u1 * Float32(Float32(Float32(-0.5) * u1) - Float32(1.0))))) * Float32(1.0)) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-(u1 * ((single(-0.5) * u1) - single(1.0)))) * single(1.0); end
\begin{array}{l}
\\
\sqrt{-u1 \cdot \left(-0.5 \cdot u1 - 1\right)} \cdot 1
\end{array}
Initial program 55.8%
sub-neg55.8%
log1p-define99.0%
Simplified99.0%
Taylor expanded in u2 around 0 80.3%
Taylor expanded in u1 around 0 71.8%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (* -1.0 u1))) 1.0))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-(-1.0f * u1)) * 1.0f;
}
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(-((-1.0e0) * u1)) * 1.0e0
end function
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-Float32(Float32(-1.0) * u1))) * Float32(1.0)) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-(single(-1.0) * u1)) * single(1.0); end
\begin{array}{l}
\\
\sqrt{--1 \cdot u1} \cdot 1
\end{array}
Initial program 55.8%
sub-neg55.8%
log1p-define99.0%
Simplified99.0%
Taylor expanded in u2 around 0 80.3%
Taylor expanded in u1 around 0 63.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (* u1 (sqrt 0.5)) 1.0))
float code(float cosTheta_i, float u1, float u2) {
return (u1 * sqrtf(0.5f)) * 1.0f;
}
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 * sqrt(0.5e0)) * 1.0e0
end function
function code(cosTheta_i, u1, u2) return Float32(Float32(u1 * sqrt(Float32(0.5))) * Float32(1.0)) end
function tmp = code(cosTheta_i, u1, u2) tmp = (u1 * sqrt(single(0.5))) * single(1.0); end
\begin{array}{l}
\\
\left(u1 \cdot \sqrt{0.5}\right) \cdot 1
\end{array}
Initial program 55.8%
sub-neg55.8%
log1p-define99.0%
Simplified99.0%
Taylor expanded in u2 around 0 80.3%
Taylor expanded in u1 around 0 71.8%
Taylor expanded in u1 around inf 18.9%
herbie shell --seed 2024077 -o generate:simplify
(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))))