
(FPCore (p x) :precision binary64 (sqrt (* 0.5 (+ 1.0 (/ x (sqrt (+ (* (* 4.0 p) p) (* x x))))))))
double code(double p, double x) {
return sqrt((0.5 * (1.0 + (x / sqrt((((4.0 * p) * p) + (x * x)))))));
}
real(8) function code(p, x)
real(8), intent (in) :: p
real(8), intent (in) :: x
code = sqrt((0.5d0 * (1.0d0 + (x / sqrt((((4.0d0 * p) * p) + (x * x)))))))
end function
public static double code(double p, double x) {
return Math.sqrt((0.5 * (1.0 + (x / Math.sqrt((((4.0 * p) * p) + (x * x)))))));
}
def code(p, x): return math.sqrt((0.5 * (1.0 + (x / math.sqrt((((4.0 * p) * p) + (x * x)))))))
function code(p, x) return sqrt(Float64(0.5 * Float64(1.0 + Float64(x / sqrt(Float64(Float64(Float64(4.0 * p) * p) + Float64(x * x))))))) end
function tmp = code(p, x) tmp = sqrt((0.5 * (1.0 + (x / sqrt((((4.0 * p) * p) + (x * x))))))); end
code[p_, x_] := N[Sqrt[N[(0.5 * N[(1.0 + N[(x / N[Sqrt[N[(N[(N[(4.0 * p), $MachinePrecision] * p), $MachinePrecision] + N[(x * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{0.5 \cdot \left(1 + \frac{x}{\sqrt{\left(4 \cdot p\right) \cdot p + x \cdot x}}\right)}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (p x) :precision binary64 (sqrt (* 0.5 (+ 1.0 (/ x (sqrt (+ (* (* 4.0 p) p) (* x x))))))))
double code(double p, double x) {
return sqrt((0.5 * (1.0 + (x / sqrt((((4.0 * p) * p) + (x * x)))))));
}
real(8) function code(p, x)
real(8), intent (in) :: p
real(8), intent (in) :: x
code = sqrt((0.5d0 * (1.0d0 + (x / sqrt((((4.0d0 * p) * p) + (x * x)))))))
end function
public static double code(double p, double x) {
return Math.sqrt((0.5 * (1.0 + (x / Math.sqrt((((4.0 * p) * p) + (x * x)))))));
}
def code(p, x): return math.sqrt((0.5 * (1.0 + (x / math.sqrt((((4.0 * p) * p) + (x * x)))))))
function code(p, x) return sqrt(Float64(0.5 * Float64(1.0 + Float64(x / sqrt(Float64(Float64(Float64(4.0 * p) * p) + Float64(x * x))))))) end
function tmp = code(p, x) tmp = sqrt((0.5 * (1.0 + (x / sqrt((((4.0 * p) * p) + (x * x))))))); end
code[p_, x_] := N[Sqrt[N[(0.5 * N[(1.0 + N[(x / N[Sqrt[N[(N[(N[(4.0 * p), $MachinePrecision] * p), $MachinePrecision] + N[(x * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{0.5 \cdot \left(1 + \frac{x}{\sqrt{\left(4 \cdot p\right) \cdot p + x \cdot x}}\right)}
\end{array}
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= (/ x (sqrt (+ (* p_m (* 4.0 p_m)) (* x x)))) -0.5) (/ p_m (- x)) (sqrt (* 0.5 (+ 1.0 (/ x (hypot (* p_m 2.0) x)))))))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if ((x / sqrt(((p_m * (4.0 * p_m)) + (x * x)))) <= -0.5) {
tmp = p_m / -x;
} else {
tmp = sqrt((0.5 * (1.0 + (x / hypot((p_m * 2.0), x)))));
}
return tmp;
}
p_m = Math.abs(p);
public static double code(double p_m, double x) {
double tmp;
if ((x / Math.sqrt(((p_m * (4.0 * p_m)) + (x * x)))) <= -0.5) {
tmp = p_m / -x;
} else {
tmp = Math.sqrt((0.5 * (1.0 + (x / Math.hypot((p_m * 2.0), x)))));
}
return tmp;
}
p_m = math.fabs(p) def code(p_m, x): tmp = 0 if (x / math.sqrt(((p_m * (4.0 * p_m)) + (x * x)))) <= -0.5: tmp = p_m / -x else: tmp = math.sqrt((0.5 * (1.0 + (x / math.hypot((p_m * 2.0), x))))) return tmp
p_m = abs(p) function code(p_m, x) tmp = 0.0 if (Float64(x / sqrt(Float64(Float64(p_m * Float64(4.0 * p_m)) + Float64(x * x)))) <= -0.5) tmp = Float64(p_m / Float64(-x)); else tmp = sqrt(Float64(0.5 * Float64(1.0 + Float64(x / hypot(Float64(p_m * 2.0), x))))); end return tmp end
p_m = abs(p); function tmp_2 = code(p_m, x) tmp = 0.0; if ((x / sqrt(((p_m * (4.0 * p_m)) + (x * x)))) <= -0.5) tmp = p_m / -x; else tmp = sqrt((0.5 * (1.0 + (x / hypot((p_m * 2.0), x))))); end tmp_2 = tmp; end
p_m = N[Abs[p], $MachinePrecision] code[p$95$m_, x_] := If[LessEqual[N[(x / N[Sqrt[N[(N[(p$95$m * N[(4.0 * p$95$m), $MachinePrecision]), $MachinePrecision] + N[(x * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], -0.5], N[(p$95$m / (-x)), $MachinePrecision], N[Sqrt[N[(0.5 * N[(1.0 + N[(x / N[Sqrt[N[(p$95$m * 2.0), $MachinePrecision] ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;\frac{x}{\sqrt{p\_m \cdot \left(4 \cdot p\_m\right) + x \cdot x}} \leq -0.5:\\
\;\;\;\;\frac{p\_m}{-x}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{0.5 \cdot \left(1 + \frac{x}{\mathsf{hypot}\left(p\_m \cdot 2, x\right)}\right)}\\
\end{array}
\end{array}
if (/.f64 x (sqrt.f64 (+.f64 (*.f64 (*.f64 #s(literal 4 binary64) p) p) (*.f64 x x)))) < -0.5Initial program 16.1%
Taylor expanded in x around -inf 38.5%
associate-*r/38.5%
Simplified38.5%
Applied egg-rr60.2%
if -0.5 < (/.f64 x (sqrt.f64 (+.f64 (*.f64 (*.f64 #s(literal 4 binary64) p) p) (*.f64 x x)))) Initial program 100.0%
add-sqr-sqrt100.0%
hypot-define100.0%
associate-*l*100.0%
sqrt-prod100.0%
metadata-eval100.0%
sqrt-unprod48.4%
add-sqr-sqrt100.0%
Applied egg-rr100.0%
Final simplification90.1%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= p_m 2.25e-279) 1.0 (if (<= p_m 2e-212) (/ p_m (- x)) (if (<= p_m 9.5e-14) 1.0 (sqrt 0.5)))))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if (p_m <= 2.25e-279) {
tmp = 1.0;
} else if (p_m <= 2e-212) {
tmp = p_m / -x;
} else if (p_m <= 9.5e-14) {
tmp = 1.0;
} else {
tmp = sqrt(0.5);
}
return tmp;
}
p_m = abs(p)
real(8) function code(p_m, x)
real(8), intent (in) :: p_m
real(8), intent (in) :: x
real(8) :: tmp
if (p_m <= 2.25d-279) then
tmp = 1.0d0
else if (p_m <= 2d-212) then
tmp = p_m / -x
else if (p_m <= 9.5d-14) then
tmp = 1.0d0
else
tmp = sqrt(0.5d0)
end if
code = tmp
end function
p_m = Math.abs(p);
public static double code(double p_m, double x) {
double tmp;
if (p_m <= 2.25e-279) {
tmp = 1.0;
} else if (p_m <= 2e-212) {
tmp = p_m / -x;
} else if (p_m <= 9.5e-14) {
tmp = 1.0;
} else {
tmp = Math.sqrt(0.5);
}
return tmp;
}
p_m = math.fabs(p) def code(p_m, x): tmp = 0 if p_m <= 2.25e-279: tmp = 1.0 elif p_m <= 2e-212: tmp = p_m / -x elif p_m <= 9.5e-14: tmp = 1.0 else: tmp = math.sqrt(0.5) return tmp
p_m = abs(p) function code(p_m, x) tmp = 0.0 if (p_m <= 2.25e-279) tmp = 1.0; elseif (p_m <= 2e-212) tmp = Float64(p_m / Float64(-x)); elseif (p_m <= 9.5e-14) tmp = 1.0; else tmp = sqrt(0.5); end return tmp end
p_m = abs(p); function tmp_2 = code(p_m, x) tmp = 0.0; if (p_m <= 2.25e-279) tmp = 1.0; elseif (p_m <= 2e-212) tmp = p_m / -x; elseif (p_m <= 9.5e-14) tmp = 1.0; else tmp = sqrt(0.5); end tmp_2 = tmp; end
p_m = N[Abs[p], $MachinePrecision] code[p$95$m_, x_] := If[LessEqual[p$95$m, 2.25e-279], 1.0, If[LessEqual[p$95$m, 2e-212], N[(p$95$m / (-x)), $MachinePrecision], If[LessEqual[p$95$m, 9.5e-14], 1.0, N[Sqrt[0.5], $MachinePrecision]]]]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;p\_m \leq 2.25 \cdot 10^{-279}:\\
\;\;\;\;1\\
\mathbf{elif}\;p\_m \leq 2 \cdot 10^{-212}:\\
\;\;\;\;\frac{p\_m}{-x}\\
\mathbf{elif}\;p\_m \leq 9.5 \cdot 10^{-14}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;\sqrt{0.5}\\
\end{array}
\end{array}
if p < 2.24999999999999998e-279 or 1.99999999999999991e-212 < p < 9.4999999999999999e-14Initial program 76.7%
add-sqr-sqrt76.7%
hypot-define76.7%
associate-*l*76.7%
sqrt-prod76.7%
metadata-eval76.7%
sqrt-unprod21.1%
add-sqr-sqrt76.7%
Applied egg-rr76.7%
Taylor expanded in x around inf 38.5%
mul-1-neg38.5%
unpow238.5%
associate-/l/38.5%
unpow238.5%
associate-*l/38.5%
associate-/l*38.5%
unpow238.5%
unsub-neg38.5%
unpow238.5%
*-lft-identity38.5%
associate-*l/38.5%
associate-/r/38.5%
unpow-138.5%
*-lft-identity38.5%
associate-*l/38.5%
associate-/r/38.5%
unpow-138.5%
pow-sqr38.5%
metadata-eval38.5%
Simplified38.5%
Taylor expanded in x around inf 45.6%
if 2.24999999999999998e-279 < p < 1.99999999999999991e-212Initial program 53.1%
Taylor expanded in x around -inf 27.6%
associate-*r/27.6%
Simplified27.6%
Applied egg-rr74.3%
if 9.4999999999999999e-14 < p Initial program 96.4%
Taylor expanded in x around 0 93.5%
Final simplification57.7%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= x -3.4e-146) (/ p_m (- x)) 1.0))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if (x <= -3.4e-146) {
tmp = p_m / -x;
} else {
tmp = 1.0;
}
return tmp;
}
p_m = abs(p)
real(8) function code(p_m, x)
real(8), intent (in) :: p_m
real(8), intent (in) :: x
real(8) :: tmp
if (x <= (-3.4d-146)) then
tmp = p_m / -x
else
tmp = 1.0d0
end if
code = tmp
end function
p_m = Math.abs(p);
public static double code(double p_m, double x) {
double tmp;
if (x <= -3.4e-146) {
tmp = p_m / -x;
} else {
tmp = 1.0;
}
return tmp;
}
p_m = math.fabs(p) def code(p_m, x): tmp = 0 if x <= -3.4e-146: tmp = p_m / -x else: tmp = 1.0 return tmp
p_m = abs(p) function code(p_m, x) tmp = 0.0 if (x <= -3.4e-146) tmp = Float64(p_m / Float64(-x)); else tmp = 1.0; end return tmp end
p_m = abs(p); function tmp_2 = code(p_m, x) tmp = 0.0; if (x <= -3.4e-146) tmp = p_m / -x; else tmp = 1.0; end tmp_2 = tmp; end
p_m = N[Abs[p], $MachinePrecision] code[p$95$m_, x_] := If[LessEqual[x, -3.4e-146], N[(p$95$m / (-x)), $MachinePrecision], 1.0]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;x \leq -3.4 \cdot 10^{-146}:\\
\;\;\;\;\frac{p\_m}{-x}\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if x < -3.4000000000000001e-146Initial program 53.7%
Taylor expanded in x around -inf 23.4%
associate-*r/23.4%
Simplified23.4%
Applied egg-rr34.6%
if -3.4000000000000001e-146 < x Initial program 100.0%
add-sqr-sqrt100.0%
hypot-define100.0%
associate-*l*100.0%
sqrt-prod100.0%
metadata-eval100.0%
sqrt-unprod50.7%
add-sqr-sqrt100.0%
Applied egg-rr100.0%
Taylor expanded in x around inf 53.6%
mul-1-neg53.6%
unpow253.6%
associate-/l/53.6%
unpow253.6%
associate-*l/53.6%
associate-/l*53.6%
unpow253.6%
unsub-neg53.6%
unpow253.6%
*-lft-identity53.6%
associate-*l/53.6%
associate-/r/53.6%
unpow-153.6%
*-lft-identity53.6%
associate-*l/53.6%
associate-/r/53.6%
unpow-153.6%
pow-sqr53.6%
metadata-eval53.6%
Simplified53.6%
Taylor expanded in x around inf 62.6%
Final simplification49.9%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= x -2.5e+65) 0.0 1.0))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if (x <= -2.5e+65) {
tmp = 0.0;
} else {
tmp = 1.0;
}
return tmp;
}
p_m = abs(p)
real(8) function code(p_m, x)
real(8), intent (in) :: p_m
real(8), intent (in) :: x
real(8) :: tmp
if (x <= (-2.5d+65)) then
tmp = 0.0d0
else
tmp = 1.0d0
end if
code = tmp
end function
p_m = Math.abs(p);
public static double code(double p_m, double x) {
double tmp;
if (x <= -2.5e+65) {
tmp = 0.0;
} else {
tmp = 1.0;
}
return tmp;
}
p_m = math.fabs(p) def code(p_m, x): tmp = 0 if x <= -2.5e+65: tmp = 0.0 else: tmp = 1.0 return tmp
p_m = abs(p) function code(p_m, x) tmp = 0.0 if (x <= -2.5e+65) tmp = 0.0; else tmp = 1.0; end return tmp end
p_m = abs(p); function tmp_2 = code(p_m, x) tmp = 0.0; if (x <= -2.5e+65) tmp = 0.0; else tmp = 1.0; end tmp_2 = tmp; end
p_m = N[Abs[p], $MachinePrecision] code[p$95$m_, x_] := If[LessEqual[x, -2.5e+65], 0.0, 1.0]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;x \leq -2.5 \cdot 10^{+65}:\\
\;\;\;\;0\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if x < -2.49999999999999986e65Initial program 58.2%
Taylor expanded in x around -inf 27.1%
metadata-eval27.1%
metadata-eval27.1%
metadata-eval27.1%
pow1/227.1%
metadata-eval27.1%
metadata-eval27.1%
Applied egg-rr27.1%
if -2.49999999999999986e65 < x Initial program 81.6%
add-sqr-sqrt81.6%
hypot-define81.6%
associate-*l*81.6%
sqrt-prod81.6%
metadata-eval81.6%
sqrt-unprod39.4%
add-sqr-sqrt81.6%
Applied egg-rr81.6%
Taylor expanded in x around inf 34.1%
mul-1-neg34.1%
unpow234.1%
associate-/l/34.1%
unpow234.1%
associate-*l/34.1%
associate-/l*34.1%
unpow234.1%
unsub-neg34.1%
unpow234.1%
*-lft-identity34.1%
associate-*l/34.1%
associate-/r/34.1%
unpow-134.1%
*-lft-identity34.1%
associate-*l/34.1%
associate-/r/34.1%
unpow-134.1%
pow-sqr34.1%
metadata-eval34.1%
Simplified34.1%
Taylor expanded in x around inf 43.3%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 0.0)
p_m = fabs(p);
double code(double p_m, double x) {
return 0.0;
}
p_m = abs(p)
real(8) function code(p_m, x)
real(8), intent (in) :: p_m
real(8), intent (in) :: x
code = 0.0d0
end function
p_m = Math.abs(p);
public static double code(double p_m, double x) {
return 0.0;
}
p_m = math.fabs(p) def code(p_m, x): return 0.0
p_m = abs(p) function code(p_m, x) return 0.0 end
p_m = abs(p); function tmp = code(p_m, x) tmp = 0.0; end
p_m = N[Abs[p], $MachinePrecision] code[p$95$m_, x_] := 0.0
\begin{array}{l}
p_m = \left|p\right|
\\
0
\end{array}
Initial program 79.0%
Taylor expanded in x around -inf 6.1%
metadata-eval6.1%
metadata-eval6.1%
metadata-eval6.1%
pow1/26.1%
metadata-eval6.1%
metadata-eval6.1%
Applied egg-rr6.1%
(FPCore (p x) :precision binary64 (sqrt (+ 0.5 (/ (copysign 0.5 x) (hypot 1.0 (/ (* 2.0 p) x))))))
double code(double p, double x) {
return sqrt((0.5 + (copysign(0.5, x) / hypot(1.0, ((2.0 * p) / x)))));
}
public static double code(double p, double x) {
return Math.sqrt((0.5 + (Math.copySign(0.5, x) / Math.hypot(1.0, ((2.0 * p) / x)))));
}
def code(p, x): return math.sqrt((0.5 + (math.copysign(0.5, x) / math.hypot(1.0, ((2.0 * p) / x)))))
function code(p, x) return sqrt(Float64(0.5 + Float64(copysign(0.5, x) / hypot(1.0, Float64(Float64(2.0 * p) / x))))) end
function tmp = code(p, x) tmp = sqrt((0.5 + ((sign(x) * abs(0.5)) / hypot(1.0, ((2.0 * p) / x))))); end
code[p_, x_] := N[Sqrt[N[(0.5 + N[(N[With[{TMP1 = Abs[0.5], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision] / N[Sqrt[1.0 ^ 2 + N[(N[(2.0 * p), $MachinePrecision] / x), $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{0.5 + \frac{\mathsf{copysign}\left(0.5, x\right)}{\mathsf{hypot}\left(1, \frac{2 \cdot p}{x}\right)}}
\end{array}
herbie shell --seed 2024152
(FPCore (p x)
:name "Given's Rotation SVD example"
:precision binary64
:pre (and (< 1e-150 (fabs x)) (< (fabs x) 1e+150))
:alt
(! :herbie-platform default (sqrt (+ 1/2 (/ (copysign 1/2 x) (hypot 1 (/ (* 2 p) x))))))
(sqrt (* 0.5 (+ 1.0 (/ x (sqrt (+ (* (* 4.0 p) p) (* x x))))))))