
(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 6 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)))) -1.0) (/ (- p_m) x) (sqrt (+ 0.5 (* 0.5 (/ x (hypot x (* p_m 2.0))))))))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if ((x / sqrt(((p_m * (4.0 * p_m)) + (x * x)))) <= -1.0) {
tmp = -p_m / x;
} else {
tmp = sqrt((0.5 + (0.5 * (x / hypot(x, (p_m * 2.0))))));
}
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)))) <= -1.0) {
tmp = -p_m / x;
} else {
tmp = Math.sqrt((0.5 + (0.5 * (x / Math.hypot(x, (p_m * 2.0))))));
}
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)))) <= -1.0: tmp = -p_m / x else: tmp = math.sqrt((0.5 + (0.5 * (x / math.hypot(x, (p_m * 2.0)))))) 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)))) <= -1.0) tmp = Float64(Float64(-p_m) / x); else tmp = sqrt(Float64(0.5 + Float64(0.5 * Float64(x / hypot(x, Float64(p_m * 2.0)))))); 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)))) <= -1.0) tmp = -p_m / x; else tmp = sqrt((0.5 + (0.5 * (x / hypot(x, (p_m * 2.0)))))); 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], -1.0], N[((-p$95$m) / x), $MachinePrecision], N[Sqrt[N[(0.5 + N[(0.5 * N[(x / N[Sqrt[x ^ 2 + N[(p$95$m * 2.0), $MachinePrecision] ^ 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 -1:\\
\;\;\;\;\frac{-p_m}{x}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{0.5 + 0.5 \cdot \frac{x}{\mathsf{hypot}\left(x, p_m \cdot 2\right)}}\\
\end{array}
\end{array}
p_m = (fabs.f64 p)
(FPCore (p_m x)
:precision binary64
(let* ((t_0 (/ (- p_m) x)) (t_1 (+ 1.0 (* -0.5 (* p_m (* x (* x p_m)))))))
(if (<= p_m 2.05e-241)
t_1
(if (<= p_m 3.6e-217)
t_0
(if (<= p_m 2.8e-194)
t_1
(if (<= p_m 3.4e-131)
t_0
(if (<= p_m 2.5e-38)
(+ 1.0 (* -0.5 (/ (* x p_m) (/ x p_m))))
(sqrt 0.5))))))))p_m = fabs(p);
double code(double p_m, double x) {
double t_0 = -p_m / x;
double t_1 = 1.0 + (-0.5 * (p_m * (x * (x * p_m))));
double tmp;
if (p_m <= 2.05e-241) {
tmp = t_1;
} else if (p_m <= 3.6e-217) {
tmp = t_0;
} else if (p_m <= 2.8e-194) {
tmp = t_1;
} else if (p_m <= 3.4e-131) {
tmp = t_0;
} else if (p_m <= 2.5e-38) {
tmp = 1.0 + (-0.5 * ((x * p_m) / (x / p_m)));
} 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) :: t_0
real(8) :: t_1
real(8) :: tmp
t_0 = -p_m / x
t_1 = 1.0d0 + ((-0.5d0) * (p_m * (x * (x * p_m))))
if (p_m <= 2.05d-241) then
tmp = t_1
else if (p_m <= 3.6d-217) then
tmp = t_0
else if (p_m <= 2.8d-194) then
tmp = t_1
else if (p_m <= 3.4d-131) then
tmp = t_0
else if (p_m <= 2.5d-38) then
tmp = 1.0d0 + ((-0.5d0) * ((x * p_m) / (x / p_m)))
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 t_0 = -p_m / x;
double t_1 = 1.0 + (-0.5 * (p_m * (x * (x * p_m))));
double tmp;
if (p_m <= 2.05e-241) {
tmp = t_1;
} else if (p_m <= 3.6e-217) {
tmp = t_0;
} else if (p_m <= 2.8e-194) {
tmp = t_1;
} else if (p_m <= 3.4e-131) {
tmp = t_0;
} else if (p_m <= 2.5e-38) {
tmp = 1.0 + (-0.5 * ((x * p_m) / (x / p_m)));
} else {
tmp = Math.sqrt(0.5);
}
return tmp;
}
p_m = math.fabs(p) def code(p_m, x): t_0 = -p_m / x t_1 = 1.0 + (-0.5 * (p_m * (x * (x * p_m)))) tmp = 0 if p_m <= 2.05e-241: tmp = t_1 elif p_m <= 3.6e-217: tmp = t_0 elif p_m <= 2.8e-194: tmp = t_1 elif p_m <= 3.4e-131: tmp = t_0 elif p_m <= 2.5e-38: tmp = 1.0 + (-0.5 * ((x * p_m) / (x / p_m))) else: tmp = math.sqrt(0.5) return tmp
p_m = abs(p) function code(p_m, x) t_0 = Float64(Float64(-p_m) / x) t_1 = Float64(1.0 + Float64(-0.5 * Float64(p_m * Float64(x * Float64(x * p_m))))) tmp = 0.0 if (p_m <= 2.05e-241) tmp = t_1; elseif (p_m <= 3.6e-217) tmp = t_0; elseif (p_m <= 2.8e-194) tmp = t_1; elseif (p_m <= 3.4e-131) tmp = t_0; elseif (p_m <= 2.5e-38) tmp = Float64(1.0 + Float64(-0.5 * Float64(Float64(x * p_m) / Float64(x / p_m)))); else tmp = sqrt(0.5); end return tmp end
p_m = abs(p); function tmp_2 = code(p_m, x) t_0 = -p_m / x; t_1 = 1.0 + (-0.5 * (p_m * (x * (x * p_m)))); tmp = 0.0; if (p_m <= 2.05e-241) tmp = t_1; elseif (p_m <= 3.6e-217) tmp = t_0; elseif (p_m <= 2.8e-194) tmp = t_1; elseif (p_m <= 3.4e-131) tmp = t_0; elseif (p_m <= 2.5e-38) tmp = 1.0 + (-0.5 * ((x * p_m) / (x / p_m))); else tmp = sqrt(0.5); end tmp_2 = tmp; end
p_m = N[Abs[p], $MachinePrecision]
code[p$95$m_, x_] := Block[{t$95$0 = N[((-p$95$m) / x), $MachinePrecision]}, Block[{t$95$1 = N[(1.0 + N[(-0.5 * N[(p$95$m * N[(x * N[(x * p$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[p$95$m, 2.05e-241], t$95$1, If[LessEqual[p$95$m, 3.6e-217], t$95$0, If[LessEqual[p$95$m, 2.8e-194], t$95$1, If[LessEqual[p$95$m, 3.4e-131], t$95$0, If[LessEqual[p$95$m, 2.5e-38], N[(1.0 + N[(-0.5 * N[(N[(x * p$95$m), $MachinePrecision] / N[(x / p$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[Sqrt[0.5], $MachinePrecision]]]]]]]]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
t_0 := \frac{-p_m}{x}\\
t_1 := 1 + -0.5 \cdot \left(p_m \cdot \left(x \cdot \left(x \cdot p_m\right)\right)\right)\\
\mathbf{if}\;p_m \leq 2.05 \cdot 10^{-241}:\\
\;\;\;\;t_1\\
\mathbf{elif}\;p_m \leq 3.6 \cdot 10^{-217}:\\
\;\;\;\;t_0\\
\mathbf{elif}\;p_m \leq 2.8 \cdot 10^{-194}:\\
\;\;\;\;t_1\\
\mathbf{elif}\;p_m \leq 3.4 \cdot 10^{-131}:\\
\;\;\;\;t_0\\
\mathbf{elif}\;p_m \leq 2.5 \cdot 10^{-38}:\\
\;\;\;\;1 + -0.5 \cdot \frac{x \cdot p_m}{\frac{x}{p_m}}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{0.5}\\
\end{array}
\end{array}
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= x -5e-149) (/ (- p_m) x) (+ 1.0 (* -0.5 (* p_m (* x (* x p_m)))))))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if (x <= -5e-149) {
tmp = -p_m / x;
} else {
tmp = 1.0 + (-0.5 * (p_m * (x * (x * p_m))));
}
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 <= (-5d-149)) then
tmp = -p_m / x
else
tmp = 1.0d0 + ((-0.5d0) * (p_m * (x * (x * p_m))))
end if
code = tmp
end function
p_m = Math.abs(p);
public static double code(double p_m, double x) {
double tmp;
if (x <= -5e-149) {
tmp = -p_m / x;
} else {
tmp = 1.0 + (-0.5 * (p_m * (x * (x * p_m))));
}
return tmp;
}
p_m = math.fabs(p) def code(p_m, x): tmp = 0 if x <= -5e-149: tmp = -p_m / x else: tmp = 1.0 + (-0.5 * (p_m * (x * (x * p_m)))) return tmp
p_m = abs(p) function code(p_m, x) tmp = 0.0 if (x <= -5e-149) tmp = Float64(Float64(-p_m) / x); else tmp = Float64(1.0 + Float64(-0.5 * Float64(p_m * Float64(x * Float64(x * p_m))))); end return tmp end
p_m = abs(p); function tmp_2 = code(p_m, x) tmp = 0.0; if (x <= -5e-149) tmp = -p_m / x; else tmp = 1.0 + (-0.5 * (p_m * (x * (x * p_m)))); end tmp_2 = tmp; end
p_m = N[Abs[p], $MachinePrecision] code[p$95$m_, x_] := If[LessEqual[x, -5e-149], N[((-p$95$m) / x), $MachinePrecision], N[(1.0 + N[(-0.5 * N[(p$95$m * N[(x * N[(x * p$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;x \leq -5 \cdot 10^{-149}:\\
\;\;\;\;\frac{-p_m}{x}\\
\mathbf{else}:\\
\;\;\;\;1 + -0.5 \cdot \left(p_m \cdot \left(x \cdot \left(x \cdot p_m\right)\right)\right)\\
\end{array}
\end{array}
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= x -7.8e-266) (/ (- p_m) x) (+ 1.0 (* -0.5 (/ (* x p_m) (/ x p_m))))))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if (x <= -7.8e-266) {
tmp = -p_m / x;
} else {
tmp = 1.0 + (-0.5 * ((x * p_m) / (x / p_m)));
}
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 <= (-7.8d-266)) then
tmp = -p_m / x
else
tmp = 1.0d0 + ((-0.5d0) * ((x * p_m) / (x / p_m)))
end if
code = tmp
end function
p_m = Math.abs(p);
public static double code(double p_m, double x) {
double tmp;
if (x <= -7.8e-266) {
tmp = -p_m / x;
} else {
tmp = 1.0 + (-0.5 * ((x * p_m) / (x / p_m)));
}
return tmp;
}
p_m = math.fabs(p) def code(p_m, x): tmp = 0 if x <= -7.8e-266: tmp = -p_m / x else: tmp = 1.0 + (-0.5 * ((x * p_m) / (x / p_m))) return tmp
p_m = abs(p) function code(p_m, x) tmp = 0.0 if (x <= -7.8e-266) tmp = Float64(Float64(-p_m) / x); else tmp = Float64(1.0 + Float64(-0.5 * Float64(Float64(x * p_m) / Float64(x / p_m)))); end return tmp end
p_m = abs(p); function tmp_2 = code(p_m, x) tmp = 0.0; if (x <= -7.8e-266) tmp = -p_m / x; else tmp = 1.0 + (-0.5 * ((x * p_m) / (x / p_m))); end tmp_2 = tmp; end
p_m = N[Abs[p], $MachinePrecision] code[p$95$m_, x_] := If[LessEqual[x, -7.8e-266], N[((-p$95$m) / x), $MachinePrecision], N[(1.0 + N[(-0.5 * N[(N[(x * p$95$m), $MachinePrecision] / N[(x / p$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;x \leq -7.8 \cdot 10^{-266}:\\
\;\;\;\;\frac{-p_m}{x}\\
\mathbf{else}:\\
\;\;\;\;1 + -0.5 \cdot \frac{x \cdot p_m}{\frac{x}{p_m}}\\
\end{array}
\end{array}
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= x -5e-149) (/ (- p_m) x) p_m))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if (x <= -5e-149) {
tmp = -p_m / x;
} else {
tmp = p_m;
}
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 <= (-5d-149)) then
tmp = -p_m / x
else
tmp = p_m
end if
code = tmp
end function
p_m = Math.abs(p);
public static double code(double p_m, double x) {
double tmp;
if (x <= -5e-149) {
tmp = -p_m / x;
} else {
tmp = p_m;
}
return tmp;
}
p_m = math.fabs(p) def code(p_m, x): tmp = 0 if x <= -5e-149: tmp = -p_m / x else: tmp = p_m return tmp
p_m = abs(p) function code(p_m, x) tmp = 0.0 if (x <= -5e-149) tmp = Float64(Float64(-p_m) / x); else tmp = p_m; end return tmp end
p_m = abs(p); function tmp_2 = code(p_m, x) tmp = 0.0; if (x <= -5e-149) tmp = -p_m / x; else tmp = p_m; end tmp_2 = tmp; end
p_m = N[Abs[p], $MachinePrecision] code[p$95$m_, x_] := If[LessEqual[x, -5e-149], N[((-p$95$m) / x), $MachinePrecision], p$95$m]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;x \leq -5 \cdot 10^{-149}:\\
\;\;\;\;\frac{-p_m}{x}\\
\mathbf{else}:\\
\;\;\;\;p_m\\
\end{array}
\end{array}
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 p_m)
p_m = fabs(p);
double code(double p_m, double x) {
return p_m;
}
p_m = abs(p)
real(8) function code(p_m, x)
real(8), intent (in) :: p_m
real(8), intent (in) :: x
code = p_m
end function
p_m = Math.abs(p);
public static double code(double p_m, double x) {
return p_m;
}
p_m = math.fabs(p) def code(p_m, x): return p_m
p_m = abs(p) function code(p_m, x) return p_m end
p_m = abs(p); function tmp = code(p_m, x) tmp = p_m; end
p_m = N[Abs[p], $MachinePrecision] code[p$95$m_, x_] := p$95$m
\begin{array}{l}
p_m = \left|p\right|
\\
p_m
\end{array}
(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 2024006
(FPCore (p x)
:name "Given's Rotation SVD example"
:precision binary64
:pre (and (< 1e-150 (fabs x)) (< (fabs x) 1e+150))
:herbie-target
(sqrt (+ 0.5 (/ (copysign 0.5 x) (hypot 1.0 (/ (* 2.0 p) x)))))
(sqrt (* 0.5 (+ 1.0 (/ x (sqrt (+ (* (* 4.0 p) p) (* x x))))))))