
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (/ u1 (- 1.0 u1))) (cos (* 6.28318530718 u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((u1 / (1.0f - u1))) * cosf((6.28318530718f * u2));
}
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))) * cos((6.28318530718e0 * u2))
end function
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(u1 / Float32(Float32(1.0) - u1))) * cos(Float32(Float32(6.28318530718) * u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt((u1 / (single(1.0) - u1))) * cos((single(6.28318530718) * u2)); end
\begin{array}{l}
\\
\sqrt{\frac{u1}{1 - u1}} \cdot \cos \left(6.28318530718 \cdot u2\right)
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (/ u1 (- 1.0 u1))) (cos (* 6.28318530718 u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((u1 / (1.0f - u1))) * cosf((6.28318530718f * u2));
}
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))) * cos((6.28318530718e0 * u2))
end function
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(u1 / Float32(Float32(1.0) - u1))) * cos(Float32(Float32(6.28318530718) * u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt((u1 / (single(1.0) - u1))) * cos((single(6.28318530718) * u2)); end
\begin{array}{l}
\\
\sqrt{\frac{u1}{1 - u1}} \cdot \cos \left(6.28318530718 \cdot u2\right)
\end{array}
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (/ u1 (- 1.0 u1))) (cos (* 6.28318530718 u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((u1 / (1.0f - u1))) * cosf((6.28318530718f * u2));
}
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))) * cos((6.28318530718e0 * u2))
end function
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(u1 / Float32(Float32(1.0) - u1))) * cos(Float32(Float32(6.28318530718) * u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt((u1 / (single(1.0) - u1))) * cos((single(6.28318530718) * u2)); end
\begin{array}{l}
\\
\sqrt{\frac{u1}{1 - u1}} \cdot \cos \left(6.28318530718 \cdot u2\right)
\end{array}
Initial program 98.9%
Final simplification98.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= (* 6.28318530718 u2) 0.005499999970197678) (sqrt (/ u1 (- 1.0 u1))) (* (cos (* 6.28318530718 u2)) (sqrt u1))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if ((6.28318530718f * u2) <= 0.005499999970197678f) {
tmp = sqrtf((u1 / (1.0f - u1)));
} else {
tmp = cosf((6.28318530718f * u2)) * sqrtf(u1);
}
return tmp;
}
real(4) function code(costheta_i, u1, u2)
real(4), intent (in) :: costheta_i
real(4), intent (in) :: u1
real(4), intent (in) :: u2
real(4) :: tmp
if ((6.28318530718e0 * u2) <= 0.005499999970197678e0) then
tmp = sqrt((u1 / (1.0e0 - u1)))
else
tmp = cos((6.28318530718e0 * u2)) * sqrt(u1)
end if
code = tmp
end function
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (Float32(Float32(6.28318530718) * u2) <= Float32(0.005499999970197678)) tmp = sqrt(Float32(u1 / Float32(Float32(1.0) - u1))); else tmp = Float32(cos(Float32(Float32(6.28318530718) * u2)) * sqrt(u1)); end return tmp end
function tmp_2 = code(cosTheta_i, u1, u2) tmp = single(0.0); if ((single(6.28318530718) * u2) <= single(0.005499999970197678)) tmp = sqrt((u1 / (single(1.0) - u1))); else tmp = cos((single(6.28318530718) * u2)) * sqrt(u1); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;6.28318530718 \cdot u2 \leq 0.005499999970197678:\\
\;\;\;\;\sqrt{\frac{u1}{1 - u1}}\\
\mathbf{else}:\\
\;\;\;\;\cos \left(6.28318530718 \cdot u2\right) \cdot \sqrt{u1}\\
\end{array}
\end{array}
if (*.f32 314159265359/50000000000 u2) < 0.00549999997Initial program 99.4%
Taylor expanded in u2 around 0 96.8%
if 0.00549999997 < (*.f32 314159265359/50000000000 u2) Initial program 97.9%
Taylor expanded in u1 around 0 74.0%
Final simplification88.6%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (* u1 (+ u1 1.0))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((u1 * (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((u1 * (u1 + 1.0e0)))
end function
function code(cosTheta_i, u1, u2) return sqrt(Float32(u1 * Float32(u1 + Float32(1.0)))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt((u1 * (u1 + single(1.0)))); end
\begin{array}{l}
\\
\sqrt{u1 \cdot \left(u1 + 1\right)}
\end{array}
Initial program 98.9%
Taylor expanded in u2 around 0 76.5%
clear-num76.5%
associate-/r/76.5%
Applied egg-rr76.5%
Taylor expanded in u1 around 0 67.7%
+-commutative67.7%
Simplified67.7%
Final simplification67.7%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (/ u1 (- 1.0 u1))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((u1 / (1.0f - 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 / (1.0e0 - u1)))
end function
function code(cosTheta_i, u1, u2) return sqrt(Float32(u1 / Float32(Float32(1.0) - u1))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt((u1 / (single(1.0) - u1))); end
\begin{array}{l}
\\
\sqrt{\frac{u1}{1 - u1}}
\end{array}
Initial program 98.9%
Taylor expanded in u2 around 0 76.5%
Final simplification76.5%
(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 98.9%
Taylor expanded in u2 around 0 76.5%
Taylor expanded in u1 around 0 59.8%
Final simplification59.8%
herbie shell --seed 2024021
(FPCore (cosTheta_i u1 u2)
:name "Trowbridge-Reitz 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 (/ u1 (- 1.0 u1))) (cos (* 6.28318530718 u2))))