
(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 14.6%
Taylor expanded in x around -inf 51.7%
Taylor expanded in p around -inf 59.7%
neg-mul-159.7%
distribute-frac-neg59.7%
Simplified59.7%
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-unprod52.4%
add-sqr-sqrt100.0%
Applied egg-rr100.0%
Final simplification89.4%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= x -1.5e-35) (/ p_m (- x)) (if (<= x 200000.0) (sqrt 0.5) 1.0)))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if (x <= -1.5e-35) {
tmp = p_m / -x;
} else if (x <= 200000.0) {
tmp = sqrt(0.5);
} 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 <= (-1.5d-35)) then
tmp = p_m / -x
else if (x <= 200000.0d0) then
tmp = sqrt(0.5d0)
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 <= -1.5e-35) {
tmp = p_m / -x;
} else if (x <= 200000.0) {
tmp = Math.sqrt(0.5);
} else {
tmp = 1.0;
}
return tmp;
}
p_m = math.fabs(p) def code(p_m, x): tmp = 0 if x <= -1.5e-35: tmp = p_m / -x elif x <= 200000.0: tmp = math.sqrt(0.5) else: tmp = 1.0 return tmp
p_m = abs(p) function code(p_m, x) tmp = 0.0 if (x <= -1.5e-35) tmp = Float64(p_m / Float64(-x)); elseif (x <= 200000.0) tmp = sqrt(0.5); else tmp = 1.0; end return tmp end
p_m = abs(p); function tmp_2 = code(p_m, x) tmp = 0.0; if (x <= -1.5e-35) tmp = p_m / -x; elseif (x <= 200000.0) tmp = sqrt(0.5); else tmp = 1.0; end tmp_2 = tmp; end
p_m = N[Abs[p], $MachinePrecision] code[p$95$m_, x_] := If[LessEqual[x, -1.5e-35], N[(p$95$m / (-x)), $MachinePrecision], If[LessEqual[x, 200000.0], N[Sqrt[0.5], $MachinePrecision], 1.0]]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.5 \cdot 10^{-35}:\\
\;\;\;\;\frac{p\_m}{-x}\\
\mathbf{elif}\;x \leq 200000:\\
\;\;\;\;\sqrt{0.5}\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if x < -1.49999999999999994e-35Initial program 37.8%
Taylor expanded in x around -inf 39.1%
Taylor expanded in p around -inf 45.9%
neg-mul-145.9%
distribute-frac-neg45.9%
Simplified45.9%
if -1.49999999999999994e-35 < x < 2e5Initial program 90.8%
Taylor expanded in x around 0 73.8%
if 2e5 < x Initial program 100.0%
Taylor expanded in x around inf 74.0%
metadata-eval74.0%
metadata-eval74.0%
Applied egg-rr74.0%
Final simplification65.7%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= x -2.6e-113) (/ p_m (- x)) 1.0))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if (x <= -2.6e-113) {
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 <= (-2.6d-113)) 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 <= -2.6e-113) {
tmp = p_m / -x;
} else {
tmp = 1.0;
}
return tmp;
}
p_m = math.fabs(p) def code(p_m, x): tmp = 0 if x <= -2.6e-113: tmp = p_m / -x else: tmp = 1.0 return tmp
p_m = abs(p) function code(p_m, x) tmp = 0.0 if (x <= -2.6e-113) 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 <= -2.6e-113) 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, -2.6e-113], N[(p$95$m / (-x)), $MachinePrecision], 1.0]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;x \leq -2.6 \cdot 10^{-113}:\\
\;\;\;\;\frac{p\_m}{-x}\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if x < -2.5999999999999999e-113Initial program 46.5%
Taylor expanded in x around -inf 34.2%
Taylor expanded in p around -inf 38.6%
neg-mul-138.6%
distribute-frac-neg38.6%
Simplified38.6%
if -2.5999999999999999e-113 < x Initial program 100.0%
Taylor expanded in x around inf 56.8%
metadata-eval56.8%
metadata-eval56.8%
Applied egg-rr56.8%
Final simplification49.2%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= x -7e+58) 0.0 1.0))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if (x <= -7e+58) {
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 <= (-7d+58)) 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 <= -7e+58) {
tmp = 0.0;
} else {
tmp = 1.0;
}
return tmp;
}
p_m = math.fabs(p) def code(p_m, x): tmp = 0 if x <= -7e+58: tmp = 0.0 else: tmp = 1.0 return tmp
p_m = abs(p) function code(p_m, x) tmp = 0.0 if (x <= -7e+58) 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 <= -7e+58) 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, -7e+58], 0.0, 1.0]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;x \leq -7 \cdot 10^{+58}:\\
\;\;\;\;0\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if x < -6.9999999999999995e58Initial program 34.0%
Taylor expanded in x around -inf 20.2%
metadata-eval20.2%
metadata-eval20.2%
metadata-eval20.2%
pow1/220.2%
metadata-eval20.2%
metadata-eval20.2%
Applied egg-rr20.2%
if -6.9999999999999995e58 < x Initial program 84.6%
Taylor expanded in x around inf 42.3%
metadata-eval42.3%
metadata-eval42.3%
Applied egg-rr42.3%
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 77.7%
Taylor expanded in x around -inf 5.9%
metadata-eval5.9%
metadata-eval5.9%
metadata-eval5.9%
pow1/25.9%
metadata-eval5.9%
metadata-eval5.9%
Applied egg-rr5.9%
(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 2024117
(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))))))))