Toniolo and Linder, Equation (3a)

Percentage Accurate: 98.7% → 98.9%
Time: 5.7s
Alternatives: 4
Speedup: 1.5×

Specification

?
\[\begin{array}{l} \\ \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \end{array} \]
(FPCore (l Om kx ky)
 :precision binary64
 (sqrt
  (*
   (/ 1.0 2.0)
   (+
    1.0
    (/
     1.0
     (sqrt
      (+
       1.0
       (*
        (pow (/ (* 2.0 l) Om) 2.0)
        (+ (pow (sin kx) 2.0) (pow (sin ky) 2.0))))))))))
double code(double l, double Om, double kx, double ky) {
	return sqrt(((1.0 / 2.0) * (1.0 + (1.0 / sqrt((1.0 + (pow(((2.0 * l) / Om), 2.0) * (pow(sin(kx), 2.0) + pow(sin(ky), 2.0)))))))));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(l, om, kx, ky)
use fmin_fmax_functions
    real(8), intent (in) :: l
    real(8), intent (in) :: om
    real(8), intent (in) :: kx
    real(8), intent (in) :: ky
    code = sqrt(((1.0d0 / 2.0d0) * (1.0d0 + (1.0d0 / sqrt((1.0d0 + ((((2.0d0 * l) / om) ** 2.0d0) * ((sin(kx) ** 2.0d0) + (sin(ky) ** 2.0d0)))))))))
end function
public static double code(double l, double Om, double kx, double ky) {
	return Math.sqrt(((1.0 / 2.0) * (1.0 + (1.0 / Math.sqrt((1.0 + (Math.pow(((2.0 * l) / Om), 2.0) * (Math.pow(Math.sin(kx), 2.0) + Math.pow(Math.sin(ky), 2.0)))))))));
}
def code(l, Om, kx, ky):
	return math.sqrt(((1.0 / 2.0) * (1.0 + (1.0 / math.sqrt((1.0 + (math.pow(((2.0 * l) / Om), 2.0) * (math.pow(math.sin(kx), 2.0) + math.pow(math.sin(ky), 2.0)))))))))
function code(l, Om, kx, ky)
	return sqrt(Float64(Float64(1.0 / 2.0) * Float64(1.0 + Float64(1.0 / sqrt(Float64(1.0 + Float64((Float64(Float64(2.0 * l) / Om) ^ 2.0) * Float64((sin(kx) ^ 2.0) + (sin(ky) ^ 2.0)))))))))
end
function tmp = code(l, Om, kx, ky)
	tmp = sqrt(((1.0 / 2.0) * (1.0 + (1.0 / sqrt((1.0 + ((((2.0 * l) / Om) ^ 2.0) * ((sin(kx) ^ 2.0) + (sin(ky) ^ 2.0)))))))));
end
code[l_, Om_, kx_, ky_] := N[Sqrt[N[(N[(1.0 / 2.0), $MachinePrecision] * N[(1.0 + N[(1.0 / N[Sqrt[N[(1.0 + N[(N[Power[N[(N[(2.0 * l), $MachinePrecision] / Om), $MachinePrecision], 2.0], $MachinePrecision] * N[(N[Power[N[Sin[kx], $MachinePrecision], 2.0], $MachinePrecision] + N[Power[N[Sin[ky], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 4 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 98.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \end{array} \]
(FPCore (l Om kx ky)
 :precision binary64
 (sqrt
  (*
   (/ 1.0 2.0)
   (+
    1.0
    (/
     1.0
     (sqrt
      (+
       1.0
       (*
        (pow (/ (* 2.0 l) Om) 2.0)
        (+ (pow (sin kx) 2.0) (pow (sin ky) 2.0))))))))))
double code(double l, double Om, double kx, double ky) {
	return sqrt(((1.0 / 2.0) * (1.0 + (1.0 / sqrt((1.0 + (pow(((2.0 * l) / Om), 2.0) * (pow(sin(kx), 2.0) + pow(sin(ky), 2.0)))))))));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(l, om, kx, ky)
use fmin_fmax_functions
    real(8), intent (in) :: l
    real(8), intent (in) :: om
    real(8), intent (in) :: kx
    real(8), intent (in) :: ky
    code = sqrt(((1.0d0 / 2.0d0) * (1.0d0 + (1.0d0 / sqrt((1.0d0 + ((((2.0d0 * l) / om) ** 2.0d0) * ((sin(kx) ** 2.0d0) + (sin(ky) ** 2.0d0)))))))))
end function
public static double code(double l, double Om, double kx, double ky) {
	return Math.sqrt(((1.0 / 2.0) * (1.0 + (1.0 / Math.sqrt((1.0 + (Math.pow(((2.0 * l) / Om), 2.0) * (Math.pow(Math.sin(kx), 2.0) + Math.pow(Math.sin(ky), 2.0)))))))));
}
def code(l, Om, kx, ky):
	return math.sqrt(((1.0 / 2.0) * (1.0 + (1.0 / math.sqrt((1.0 + (math.pow(((2.0 * l) / Om), 2.0) * (math.pow(math.sin(kx), 2.0) + math.pow(math.sin(ky), 2.0)))))))))
function code(l, Om, kx, ky)
	return sqrt(Float64(Float64(1.0 / 2.0) * Float64(1.0 + Float64(1.0 / sqrt(Float64(1.0 + Float64((Float64(Float64(2.0 * l) / Om) ^ 2.0) * Float64((sin(kx) ^ 2.0) + (sin(ky) ^ 2.0)))))))))
end
function tmp = code(l, Om, kx, ky)
	tmp = sqrt(((1.0 / 2.0) * (1.0 + (1.0 / sqrt((1.0 + ((((2.0 * l) / Om) ^ 2.0) * ((sin(kx) ^ 2.0) + (sin(ky) ^ 2.0)))))))));
end
code[l_, Om_, kx_, ky_] := N[Sqrt[N[(N[(1.0 / 2.0), $MachinePrecision] * N[(1.0 + N[(1.0 / N[Sqrt[N[(1.0 + N[(N[Power[N[(N[(2.0 * l), $MachinePrecision] / Om), $MachinePrecision], 2.0], $MachinePrecision] * N[(N[Power[N[Sin[kx], $MachinePrecision], 2.0], $MachinePrecision] + N[Power[N[Sin[ky], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)}
\end{array}

Alternative 1: 98.9% accurate, 1.5× speedup?

\[\begin{array}{l} kx_m = \left|kx\right| \\ ky_m = \left|ky\right| \\ [l, Om, kx_m, ky_m] = \mathsf{sort}([l, Om, kx_m, ky_m])\\ \\ \begin{array}{l} \mathbf{if}\;ky\_m \leq 5 \cdot 10^{-165}:\\ \;\;\;\;\sqrt{0.5 \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{\left(ky\_m \cdot \ell\right) \cdot \left(ky\_m \cdot \ell\right)}{Om \cdot Om}, 4, 1\right)}}\right)}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot {\sin ky\_m}^{2}}}\right)}\\ \end{array} \end{array} \]
kx_m = (fabs.f64 kx)
ky_m = (fabs.f64 ky)
NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
(FPCore (l Om kx_m ky_m)
 :precision binary64
 (if (<= ky_m 5e-165)
   (sqrt
    (*
     0.5
     (+
      1.0
      (/ 1.0 (sqrt (fma (/ (* (* ky_m l) (* ky_m l)) (* Om Om)) 4.0 1.0))))))
   (sqrt
    (*
     (/ 1.0 2.0)
     (+
      1.0
      (/
       1.0
       (sqrt (+ 1.0 (* (pow (/ (* 2.0 l) Om) 2.0) (pow (sin ky_m) 2.0))))))))))
kx_m = fabs(kx);
ky_m = fabs(ky);
assert(l < Om && Om < kx_m && kx_m < ky_m);
double code(double l, double Om, double kx_m, double ky_m) {
	double tmp;
	if (ky_m <= 5e-165) {
		tmp = sqrt((0.5 * (1.0 + (1.0 / sqrt(fma((((ky_m * l) * (ky_m * l)) / (Om * Om)), 4.0, 1.0))))));
	} else {
		tmp = sqrt(((1.0 / 2.0) * (1.0 + (1.0 / sqrt((1.0 + (pow(((2.0 * l) / Om), 2.0) * pow(sin(ky_m), 2.0))))))));
	}
	return tmp;
}
kx_m = abs(kx)
ky_m = abs(ky)
l, Om, kx_m, ky_m = sort([l, Om, kx_m, ky_m])
function code(l, Om, kx_m, ky_m)
	tmp = 0.0
	if (ky_m <= 5e-165)
		tmp = sqrt(Float64(0.5 * Float64(1.0 + Float64(1.0 / sqrt(fma(Float64(Float64(Float64(ky_m * l) * Float64(ky_m * l)) / Float64(Om * Om)), 4.0, 1.0))))));
	else
		tmp = sqrt(Float64(Float64(1.0 / 2.0) * Float64(1.0 + Float64(1.0 / sqrt(Float64(1.0 + Float64((Float64(Float64(2.0 * l) / Om) ^ 2.0) * (sin(ky_m) ^ 2.0))))))));
	end
	return tmp
end
kx_m = N[Abs[kx], $MachinePrecision]
ky_m = N[Abs[ky], $MachinePrecision]
NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
code[l_, Om_, kx$95$m_, ky$95$m_] := If[LessEqual[ky$95$m, 5e-165], N[Sqrt[N[(0.5 * N[(1.0 + N[(1.0 / N[Sqrt[N[(N[(N[(N[(ky$95$m * l), $MachinePrecision] * N[(ky$95$m * l), $MachinePrecision]), $MachinePrecision] / N[(Om * Om), $MachinePrecision]), $MachinePrecision] * 4.0 + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], N[Sqrt[N[(N[(1.0 / 2.0), $MachinePrecision] * N[(1.0 + N[(1.0 / N[Sqrt[N[(1.0 + N[(N[Power[N[(N[(2.0 * l), $MachinePrecision] / Om), $MachinePrecision], 2.0], $MachinePrecision] * N[Power[N[Sin[ky$95$m], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}
kx_m = \left|kx\right|
\\
ky_m = \left|ky\right|
\\
[l, Om, kx_m, ky_m] = \mathsf{sort}([l, Om, kx_m, ky_m])\\
\\
\begin{array}{l}
\mathbf{if}\;ky\_m \leq 5 \cdot 10^{-165}:\\
\;\;\;\;\sqrt{0.5 \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{\left(ky\_m \cdot \ell\right) \cdot \left(ky\_m \cdot \ell\right)}{Om \cdot Om}, 4, 1\right)}}\right)}\\

\mathbf{else}:\\
\;\;\;\;\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot {\sin ky\_m}^{2}}}\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if ky < 4.99999999999999981e-165

    1. Initial program 97.6%

      \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in kx around 0

      \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\color{blue}{1 + 4 \cdot \frac{{\ell}^{2} \cdot {\sin ky}^{2}}{{Om}^{2}}}}}\right)} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{4 \cdot \frac{{\ell}^{2} \cdot {\sin ky}^{2}}{{Om}^{2}} + \color{blue}{1}}}\right)} \]
      2. *-commutativeN/A

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\frac{{\ell}^{2} \cdot {\sin ky}^{2}}{{Om}^{2}} \cdot 4 + 1}}\right)} \]
      3. lower-fma.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{{\ell}^{2} \cdot {\sin ky}^{2}}{{Om}^{2}}, \color{blue}{4}, 1\right)}}\right)} \]
      4. lower-/.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{{\ell}^{2} \cdot {\sin ky}^{2}}{{Om}^{2}}, 4, 1\right)}}\right)} \]
      5. pow-prod-downN/A

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{{\left(\ell \cdot \sin ky\right)}^{2}}{{Om}^{2}}, 4, 1\right)}}\right)} \]
      6. lower-pow.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{{\left(\ell \cdot \sin ky\right)}^{2}}{{Om}^{2}}, 4, 1\right)}}\right)} \]
      7. lower-*.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{{\left(\ell \cdot \sin ky\right)}^{2}}{{Om}^{2}}, 4, 1\right)}}\right)} \]
      8. lift-sin.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{{\left(\ell \cdot \sin ky\right)}^{2}}{{Om}^{2}}, 4, 1\right)}}\right)} \]
      9. unpow2N/A

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{{\left(\ell \cdot \sin ky\right)}^{2}}{Om \cdot Om}, 4, 1\right)}}\right)} \]
      10. lower-*.f6487.9

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{{\left(\ell \cdot \sin ky\right)}^{2}}{Om \cdot Om}, 4, 1\right)}}\right)} \]
    5. Applied rewrites87.9%

      \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\color{blue}{\mathsf{fma}\left(\frac{{\left(\ell \cdot \sin ky\right)}^{2}}{Om \cdot Om}, 4, 1\right)}}}\right)} \]
    6. Taylor expanded in ky around 0

      \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{{\left(\ell \cdot ky\right)}^{2}}{Om \cdot Om}, 4, 1\right)}}\right)} \]
    7. Step-by-step derivation
      1. Applied rewrites79.6%

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{{\left(\ell \cdot ky\right)}^{2}}{Om \cdot Om}, 4, 1\right)}}\right)} \]
      2. Step-by-step derivation
        1. lift-pow.f64N/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{{\left(\ell \cdot ky\right)}^{2}}{Om \cdot Om}, 4, 1\right)}}\right)} \]
        2. unpow2N/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{\left(\ell \cdot ky\right) \cdot \left(\ell \cdot ky\right)}{Om \cdot Om}, 4, 1\right)}}\right)} \]
        3. lower-*.f6479.6

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{\left(\ell \cdot ky\right) \cdot \left(\ell \cdot ky\right)}{Om \cdot Om}, 4, 1\right)}}\right)} \]
        4. lift-*.f64N/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{\left(\ell \cdot ky\right) \cdot \left(\ell \cdot ky\right)}{Om \cdot Om}, 4, 1\right)}}\right)} \]
        5. *-commutativeN/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{\left(ky \cdot \ell\right) \cdot \left(\ell \cdot ky\right)}{Om \cdot Om}, 4, 1\right)}}\right)} \]
        6. lower-*.f6479.6

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{\left(ky \cdot \ell\right) \cdot \left(\ell \cdot ky\right)}{Om \cdot Om}, 4, 1\right)}}\right)} \]
        7. lift-*.f64N/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{\left(ky \cdot \ell\right) \cdot \left(\ell \cdot ky\right)}{Om \cdot Om}, 4, 1\right)}}\right)} \]
        8. *-commutativeN/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{\left(ky \cdot \ell\right) \cdot \left(ky \cdot \ell\right)}{Om \cdot Om}, 4, 1\right)}}\right)} \]
        9. lower-*.f6479.6

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{\left(ky \cdot \ell\right) \cdot \left(ky \cdot \ell\right)}{Om \cdot Om}, 4, 1\right)}}\right)} \]
      3. Applied rewrites79.6%

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{\left(ky \cdot \ell\right) \cdot \left(ky \cdot \ell\right)}{Om \cdot Om}, 4, 1\right)}}\right)} \]
      4. Step-by-step derivation
        1. lift-/.f64N/A

          \[\leadsto \sqrt{\color{blue}{\frac{1}{2}} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{\left(ky \cdot \ell\right) \cdot \left(ky \cdot \ell\right)}{Om \cdot Om}, 4, 1\right)}}\right)} \]
        2. metadata-eval79.6

          \[\leadsto \sqrt{\color{blue}{0.5} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{\left(ky \cdot \ell\right) \cdot \left(ky \cdot \ell\right)}{Om \cdot Om}, 4, 1\right)}}\right)} \]
      5. Applied rewrites79.6%

        \[\leadsto \sqrt{\color{blue}{0.5} \cdot \left(1 + \frac{1}{\sqrt{\mathsf{fma}\left(\frac{\left(ky \cdot \ell\right) \cdot \left(ky \cdot \ell\right)}{Om \cdot Om}, 4, 1\right)}}\right)} \]

      if 4.99999999999999981e-165 < ky

      1. Initial program 100.0%

        \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
      2. Add Preprocessing
      3. Taylor expanded in kx around 0

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \color{blue}{{\sin ky}^{2}}}}\right)} \]
      4. Step-by-step derivation
        1. lift-sin.f64N/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot {\sin ky}^{2}}}\right)} \]
        2. lift-pow.f6497.5

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot {\sin ky}^{\color{blue}{2}}}}\right)} \]
      5. Applied rewrites97.5%

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \color{blue}{{\sin ky}^{2}}}}\right)} \]
    8. Recombined 2 regimes into one program.
    9. Add Preprocessing

    Alternative 2: 98.8% accurate, 0.8× speedup?

    \[\begin{array}{l} kx_m = \left|kx\right| \\ ky_m = \left|ky\right| \\ [l, Om, kx_m, ky_m] = \mathsf{sort}([l, Om, kx_m, ky_m])\\ \\ \begin{array}{l} t_0 := \frac{\ell \cdot 2}{Om}\\ \mathbf{if}\;\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx\_m}^{2} + {\sin ky\_m}^{2}\right)} \leq 500:\\ \;\;\;\;\sqrt{0.5 \cdot \left(1 + \frac{1}{\sqrt{1 + \left(t\_0 \cdot t\_0\right) \cdot \left(0.5 - 0.5 \cdot \cos \left(2 \cdot ky\_m\right)\right)}}\right)}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{0.5}\\ \end{array} \end{array} \]
    kx_m = (fabs.f64 kx)
    ky_m = (fabs.f64 ky)
    NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
    (FPCore (l Om kx_m ky_m)
     :precision binary64
     (let* ((t_0 (/ (* l 2.0) Om)))
       (if (<=
            (sqrt
             (+
              1.0
              (*
               (pow (/ (* 2.0 l) Om) 2.0)
               (+ (pow (sin kx_m) 2.0) (pow (sin ky_m) 2.0)))))
            500.0)
         (sqrt
          (*
           0.5
           (+
            1.0
            (/
             1.0
             (sqrt (+ 1.0 (* (* t_0 t_0) (- 0.5 (* 0.5 (cos (* 2.0 ky_m)))))))))))
         (sqrt 0.5))))
    kx_m = fabs(kx);
    ky_m = fabs(ky);
    assert(l < Om && Om < kx_m && kx_m < ky_m);
    double code(double l, double Om, double kx_m, double ky_m) {
    	double t_0 = (l * 2.0) / Om;
    	double tmp;
    	if (sqrt((1.0 + (pow(((2.0 * l) / Om), 2.0) * (pow(sin(kx_m), 2.0) + pow(sin(ky_m), 2.0))))) <= 500.0) {
    		tmp = sqrt((0.5 * (1.0 + (1.0 / sqrt((1.0 + ((t_0 * t_0) * (0.5 - (0.5 * cos((2.0 * ky_m)))))))))));
    	} else {
    		tmp = sqrt(0.5);
    	}
    	return tmp;
    }
    
    kx_m =     private
    ky_m =     private
    NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
    module fmin_fmax_functions
        implicit none
        private
        public fmax
        public fmin
    
        interface fmax
            module procedure fmax88
            module procedure fmax44
            module procedure fmax84
            module procedure fmax48
        end interface
        interface fmin
            module procedure fmin88
            module procedure fmin44
            module procedure fmin84
            module procedure fmin48
        end interface
    contains
        real(8) function fmax88(x, y) result (res)
            real(8), intent (in) :: x
            real(8), intent (in) :: y
            res = merge(y, merge(x, max(x, y), y /= y), x /= x)
        end function
        real(4) function fmax44(x, y) result (res)
            real(4), intent (in) :: x
            real(4), intent (in) :: y
            res = merge(y, merge(x, max(x, y), y /= y), x /= x)
        end function
        real(8) function fmax84(x, y) result(res)
            real(8), intent (in) :: x
            real(4), intent (in) :: y
            res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
        end function
        real(8) function fmax48(x, y) result(res)
            real(4), intent (in) :: x
            real(8), intent (in) :: y
            res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
        end function
        real(8) function fmin88(x, y) result (res)
            real(8), intent (in) :: x
            real(8), intent (in) :: y
            res = merge(y, merge(x, min(x, y), y /= y), x /= x)
        end function
        real(4) function fmin44(x, y) result (res)
            real(4), intent (in) :: x
            real(4), intent (in) :: y
            res = merge(y, merge(x, min(x, y), y /= y), x /= x)
        end function
        real(8) function fmin84(x, y) result(res)
            real(8), intent (in) :: x
            real(4), intent (in) :: y
            res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
        end function
        real(8) function fmin48(x, y) result(res)
            real(4), intent (in) :: x
            real(8), intent (in) :: y
            res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
        end function
    end module
    
    real(8) function code(l, om, kx_m, ky_m)
    use fmin_fmax_functions
        real(8), intent (in) :: l
        real(8), intent (in) :: om
        real(8), intent (in) :: kx_m
        real(8), intent (in) :: ky_m
        real(8) :: t_0
        real(8) :: tmp
        t_0 = (l * 2.0d0) / om
        if (sqrt((1.0d0 + ((((2.0d0 * l) / om) ** 2.0d0) * ((sin(kx_m) ** 2.0d0) + (sin(ky_m) ** 2.0d0))))) <= 500.0d0) then
            tmp = sqrt((0.5d0 * (1.0d0 + (1.0d0 / sqrt((1.0d0 + ((t_0 * t_0) * (0.5d0 - (0.5d0 * cos((2.0d0 * ky_m)))))))))))
        else
            tmp = sqrt(0.5d0)
        end if
        code = tmp
    end function
    
    kx_m = Math.abs(kx);
    ky_m = Math.abs(ky);
    assert l < Om && Om < kx_m && kx_m < ky_m;
    public static double code(double l, double Om, double kx_m, double ky_m) {
    	double t_0 = (l * 2.0) / Om;
    	double tmp;
    	if (Math.sqrt((1.0 + (Math.pow(((2.0 * l) / Om), 2.0) * (Math.pow(Math.sin(kx_m), 2.0) + Math.pow(Math.sin(ky_m), 2.0))))) <= 500.0) {
    		tmp = Math.sqrt((0.5 * (1.0 + (1.0 / Math.sqrt((1.0 + ((t_0 * t_0) * (0.5 - (0.5 * Math.cos((2.0 * ky_m)))))))))));
    	} else {
    		tmp = Math.sqrt(0.5);
    	}
    	return tmp;
    }
    
    kx_m = math.fabs(kx)
    ky_m = math.fabs(ky)
    [l, Om, kx_m, ky_m] = sort([l, Om, kx_m, ky_m])
    def code(l, Om, kx_m, ky_m):
    	t_0 = (l * 2.0) / Om
    	tmp = 0
    	if math.sqrt((1.0 + (math.pow(((2.0 * l) / Om), 2.0) * (math.pow(math.sin(kx_m), 2.0) + math.pow(math.sin(ky_m), 2.0))))) <= 500.0:
    		tmp = math.sqrt((0.5 * (1.0 + (1.0 / math.sqrt((1.0 + ((t_0 * t_0) * (0.5 - (0.5 * math.cos((2.0 * ky_m)))))))))))
    	else:
    		tmp = math.sqrt(0.5)
    	return tmp
    
    kx_m = abs(kx)
    ky_m = abs(ky)
    l, Om, kx_m, ky_m = sort([l, Om, kx_m, ky_m])
    function code(l, Om, kx_m, ky_m)
    	t_0 = Float64(Float64(l * 2.0) / Om)
    	tmp = 0.0
    	if (sqrt(Float64(1.0 + Float64((Float64(Float64(2.0 * l) / Om) ^ 2.0) * Float64((sin(kx_m) ^ 2.0) + (sin(ky_m) ^ 2.0))))) <= 500.0)
    		tmp = sqrt(Float64(0.5 * Float64(1.0 + Float64(1.0 / sqrt(Float64(1.0 + Float64(Float64(t_0 * t_0) * Float64(0.5 - Float64(0.5 * cos(Float64(2.0 * ky_m)))))))))));
    	else
    		tmp = sqrt(0.5);
    	end
    	return tmp
    end
    
    kx_m = abs(kx);
    ky_m = abs(ky);
    l, Om, kx_m, ky_m = num2cell(sort([l, Om, kx_m, ky_m])){:}
    function tmp_2 = code(l, Om, kx_m, ky_m)
    	t_0 = (l * 2.0) / Om;
    	tmp = 0.0;
    	if (sqrt((1.0 + ((((2.0 * l) / Om) ^ 2.0) * ((sin(kx_m) ^ 2.0) + (sin(ky_m) ^ 2.0))))) <= 500.0)
    		tmp = sqrt((0.5 * (1.0 + (1.0 / sqrt((1.0 + ((t_0 * t_0) * (0.5 - (0.5 * cos((2.0 * ky_m)))))))))));
    	else
    		tmp = sqrt(0.5);
    	end
    	tmp_2 = tmp;
    end
    
    kx_m = N[Abs[kx], $MachinePrecision]
    ky_m = N[Abs[ky], $MachinePrecision]
    NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
    code[l_, Om_, kx$95$m_, ky$95$m_] := Block[{t$95$0 = N[(N[(l * 2.0), $MachinePrecision] / Om), $MachinePrecision]}, If[LessEqual[N[Sqrt[N[(1.0 + N[(N[Power[N[(N[(2.0 * l), $MachinePrecision] / Om), $MachinePrecision], 2.0], $MachinePrecision] * N[(N[Power[N[Sin[kx$95$m], $MachinePrecision], 2.0], $MachinePrecision] + N[Power[N[Sin[ky$95$m], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], 500.0], N[Sqrt[N[(0.5 * N[(1.0 + N[(1.0 / N[Sqrt[N[(1.0 + N[(N[(t$95$0 * t$95$0), $MachinePrecision] * N[(0.5 - N[(0.5 * N[Cos[N[(2.0 * ky$95$m), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], N[Sqrt[0.5], $MachinePrecision]]]
    
    \begin{array}{l}
    kx_m = \left|kx\right|
    \\
    ky_m = \left|ky\right|
    \\
    [l, Om, kx_m, ky_m] = \mathsf{sort}([l, Om, kx_m, ky_m])\\
    \\
    \begin{array}{l}
    t_0 := \frac{\ell \cdot 2}{Om}\\
    \mathbf{if}\;\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx\_m}^{2} + {\sin ky\_m}^{2}\right)} \leq 500:\\
    \;\;\;\;\sqrt{0.5 \cdot \left(1 + \frac{1}{\sqrt{1 + \left(t\_0 \cdot t\_0\right) \cdot \left(0.5 - 0.5 \cdot \cos \left(2 \cdot ky\_m\right)\right)}}\right)}\\
    
    \mathbf{else}:\\
    \;\;\;\;\sqrt{0.5}\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (sqrt.f64 (+.f64 #s(literal 1 binary64) (*.f64 (pow.f64 (/.f64 (*.f64 #s(literal 2 binary64) l) Om) #s(literal 2 binary64)) (+.f64 (pow.f64 (sin.f64 kx) #s(literal 2 binary64)) (pow.f64 (sin.f64 ky) #s(literal 2 binary64)))))) < 500

      1. Initial program 100.0%

        \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
      2. Add Preprocessing
      3. Taylor expanded in kx around 0

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \color{blue}{{\sin ky}^{2}}}}\right)} \]
      4. Step-by-step derivation
        1. lift-sin.f64N/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot {\sin ky}^{2}}}\right)} \]
        2. lift-pow.f6498.5

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot {\sin ky}^{\color{blue}{2}}}}\right)} \]
      5. Applied rewrites98.5%

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \color{blue}{{\sin ky}^{2}}}}\right)} \]
      6. Step-by-step derivation
        1. lift-pow.f64N/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot {\sin ky}^{\color{blue}{2}}}}\right)} \]
        2. lift-sin.f64N/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot {\sin ky}^{2}}}\right)} \]
        3. unpow2N/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left(\sin ky \cdot \color{blue}{\sin ky}\right)}}\right)} \]
        4. sqr-sin-aN/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left(\frac{1}{2} - \color{blue}{\frac{1}{2} \cdot \cos \left(2 \cdot ky\right)}\right)}}\right)} \]
        5. metadata-evalN/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left(\frac{1}{2} - \color{blue}{\frac{1}{2}} \cdot \cos \left(2 \cdot ky\right)\right)}}\right)} \]
        6. lower--.f64N/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left(\frac{1}{2} - \color{blue}{\frac{1}{2} \cdot \cos \left(2 \cdot ky\right)}\right)}}\right)} \]
        7. metadata-evalN/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left(\frac{1}{2} - \color{blue}{\frac{1}{2}} \cdot \cos \left(2 \cdot ky\right)\right)}}\right)} \]
        8. metadata-evalN/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \color{blue}{\left(2 \cdot ky\right)}\right)}}\right)} \]
        9. lower-*.f64N/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \color{blue}{\cos \left(2 \cdot ky\right)}\right)}}\right)} \]
        10. metadata-evalN/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \color{blue}{\left(2 \cdot ky\right)}\right)}}\right)} \]
        11. lower-cos.f64N/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}}\right)} \]
        12. lower-*.f6498.1

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left(0.5 - 0.5 \cdot \cos \left(2 \cdot ky\right)\right)}}\right)} \]
      7. Applied rewrites98.1%

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left(0.5 - \color{blue}{0.5 \cdot \cos \left(2 \cdot ky\right)}\right)}}\right)} \]
      8. Step-by-step derivation
        1. lift-pow.f64N/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + \color{blue}{{\left(\frac{2 \cdot \ell}{Om}\right)}^{2}} \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}}\right)} \]
        2. lift-*.f64N/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{\color{blue}{2 \cdot \ell}}{Om}\right)}^{2} \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}}\right)} \]
        3. lift-/.f64N/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\color{blue}{\left(\frac{2 \cdot \ell}{Om}\right)}}^{2} \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}}\right)} \]
        4. unpow2N/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + \color{blue}{\left(\frac{2 \cdot \ell}{Om} \cdot \frac{2 \cdot \ell}{Om}\right)} \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}}\right)} \]
        5. lower-*.f64N/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + \color{blue}{\left(\frac{2 \cdot \ell}{Om} \cdot \frac{2 \cdot \ell}{Om}\right)} \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}}\right)} \]
        6. lift-/.f64N/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + \left(\color{blue}{\frac{2 \cdot \ell}{Om}} \cdot \frac{2 \cdot \ell}{Om}\right) \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}}\right)} \]
        7. *-commutativeN/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + \left(\frac{\color{blue}{\ell \cdot 2}}{Om} \cdot \frac{2 \cdot \ell}{Om}\right) \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}}\right)} \]
        8. lower-*.f64N/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + \left(\frac{\color{blue}{\ell \cdot 2}}{Om} \cdot \frac{2 \cdot \ell}{Om}\right) \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}}\right)} \]
        9. lift-/.f64N/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + \left(\frac{\ell \cdot 2}{Om} \cdot \color{blue}{\frac{2 \cdot \ell}{Om}}\right) \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}}\right)} \]
        10. *-commutativeN/A

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + \left(\frac{\ell \cdot 2}{Om} \cdot \frac{\color{blue}{\ell \cdot 2}}{Om}\right) \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}}\right)} \]
        11. lower-*.f6498.1

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + \left(\frac{\ell \cdot 2}{Om} \cdot \frac{\color{blue}{\ell \cdot 2}}{Om}\right) \cdot \left(0.5 - 0.5 \cdot \cos \left(2 \cdot ky\right)\right)}}\right)} \]
      9. Applied rewrites98.1%

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + \color{blue}{\left(\frac{\ell \cdot 2}{Om} \cdot \frac{\ell \cdot 2}{Om}\right)} \cdot \left(0.5 - 0.5 \cdot \cos \left(2 \cdot ky\right)\right)}}\right)} \]
      10. Step-by-step derivation
        1. lift-/.f64N/A

          \[\leadsto \sqrt{\color{blue}{\frac{1}{2}} \cdot \left(1 + \frac{1}{\sqrt{1 + \left(\frac{\ell \cdot 2}{Om} \cdot \frac{\ell \cdot 2}{Om}\right) \cdot \left(\frac{1}{2} - \frac{1}{2} \cdot \cos \left(2 \cdot ky\right)\right)}}\right)} \]
        2. metadata-eval98.1

          \[\leadsto \sqrt{\color{blue}{0.5} \cdot \left(1 + \frac{1}{\sqrt{1 + \left(\frac{\ell \cdot 2}{Om} \cdot \frac{\ell \cdot 2}{Om}\right) \cdot \left(0.5 - 0.5 \cdot \cos \left(2 \cdot ky\right)\right)}}\right)} \]
      11. Applied rewrites98.1%

        \[\leadsto \sqrt{\color{blue}{0.5} \cdot \left(1 + \frac{1}{\sqrt{1 + \left(\frac{\ell \cdot 2}{Om} \cdot \frac{\ell \cdot 2}{Om}\right) \cdot \left(0.5 - 0.5 \cdot \cos \left(2 \cdot ky\right)\right)}}\right)} \]

      if 500 < (sqrt.f64 (+.f64 #s(literal 1 binary64) (*.f64 (pow.f64 (/.f64 (*.f64 #s(literal 2 binary64) l) Om) #s(literal 2 binary64)) (+.f64 (pow.f64 (sin.f64 kx) #s(literal 2 binary64)) (pow.f64 (sin.f64 ky) #s(literal 2 binary64))))))

      1. Initial program 96.6%

        \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
      2. Add Preprocessing
      3. Taylor expanded in l around inf

        \[\leadsto \sqrt{\color{blue}{\frac{1}{2}}} \]
      4. Step-by-step derivation
        1. Applied rewrites100.0%

          \[\leadsto \sqrt{\color{blue}{0.5}} \]
      5. Recombined 2 regimes into one program.
      6. Add Preprocessing

      Alternative 3: 98.4% accurate, 1.0× speedup?

      \[\begin{array}{l} kx_m = \left|kx\right| \\ ky_m = \left|ky\right| \\ [l, Om, kx_m, ky_m] = \mathsf{sort}([l, Om, kx_m, ky_m])\\ \\ \begin{array}{l} \mathbf{if}\;\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx\_m}^{2} + {\sin ky\_m}^{2}\right)} \leq 2:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;\sqrt{0.5}\\ \end{array} \end{array} \]
      kx_m = (fabs.f64 kx)
      ky_m = (fabs.f64 ky)
      NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
      (FPCore (l Om kx_m ky_m)
       :precision binary64
       (if (<=
            (sqrt
             (+
              1.0
              (*
               (pow (/ (* 2.0 l) Om) 2.0)
               (+ (pow (sin kx_m) 2.0) (pow (sin ky_m) 2.0)))))
            2.0)
         1.0
         (sqrt 0.5)))
      kx_m = fabs(kx);
      ky_m = fabs(ky);
      assert(l < Om && Om < kx_m && kx_m < ky_m);
      double code(double l, double Om, double kx_m, double ky_m) {
      	double tmp;
      	if (sqrt((1.0 + (pow(((2.0 * l) / Om), 2.0) * (pow(sin(kx_m), 2.0) + pow(sin(ky_m), 2.0))))) <= 2.0) {
      		tmp = 1.0;
      	} else {
      		tmp = sqrt(0.5);
      	}
      	return tmp;
      }
      
      kx_m =     private
      ky_m =     private
      NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
      module fmin_fmax_functions
          implicit none
          private
          public fmax
          public fmin
      
          interface fmax
              module procedure fmax88
              module procedure fmax44
              module procedure fmax84
              module procedure fmax48
          end interface
          interface fmin
              module procedure fmin88
              module procedure fmin44
              module procedure fmin84
              module procedure fmin48
          end interface
      contains
          real(8) function fmax88(x, y) result (res)
              real(8), intent (in) :: x
              real(8), intent (in) :: y
              res = merge(y, merge(x, max(x, y), y /= y), x /= x)
          end function
          real(4) function fmax44(x, y) result (res)
              real(4), intent (in) :: x
              real(4), intent (in) :: y
              res = merge(y, merge(x, max(x, y), y /= y), x /= x)
          end function
          real(8) function fmax84(x, y) result(res)
              real(8), intent (in) :: x
              real(4), intent (in) :: y
              res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
          end function
          real(8) function fmax48(x, y) result(res)
              real(4), intent (in) :: x
              real(8), intent (in) :: y
              res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
          end function
          real(8) function fmin88(x, y) result (res)
              real(8), intent (in) :: x
              real(8), intent (in) :: y
              res = merge(y, merge(x, min(x, y), y /= y), x /= x)
          end function
          real(4) function fmin44(x, y) result (res)
              real(4), intent (in) :: x
              real(4), intent (in) :: y
              res = merge(y, merge(x, min(x, y), y /= y), x /= x)
          end function
          real(8) function fmin84(x, y) result(res)
              real(8), intent (in) :: x
              real(4), intent (in) :: y
              res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
          end function
          real(8) function fmin48(x, y) result(res)
              real(4), intent (in) :: x
              real(8), intent (in) :: y
              res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
          end function
      end module
      
      real(8) function code(l, om, kx_m, ky_m)
      use fmin_fmax_functions
          real(8), intent (in) :: l
          real(8), intent (in) :: om
          real(8), intent (in) :: kx_m
          real(8), intent (in) :: ky_m
          real(8) :: tmp
          if (sqrt((1.0d0 + ((((2.0d0 * l) / om) ** 2.0d0) * ((sin(kx_m) ** 2.0d0) + (sin(ky_m) ** 2.0d0))))) <= 2.0d0) then
              tmp = 1.0d0
          else
              tmp = sqrt(0.5d0)
          end if
          code = tmp
      end function
      
      kx_m = Math.abs(kx);
      ky_m = Math.abs(ky);
      assert l < Om && Om < kx_m && kx_m < ky_m;
      public static double code(double l, double Om, double kx_m, double ky_m) {
      	double tmp;
      	if (Math.sqrt((1.0 + (Math.pow(((2.0 * l) / Om), 2.0) * (Math.pow(Math.sin(kx_m), 2.0) + Math.pow(Math.sin(ky_m), 2.0))))) <= 2.0) {
      		tmp = 1.0;
      	} else {
      		tmp = Math.sqrt(0.5);
      	}
      	return tmp;
      }
      
      kx_m = math.fabs(kx)
      ky_m = math.fabs(ky)
      [l, Om, kx_m, ky_m] = sort([l, Om, kx_m, ky_m])
      def code(l, Om, kx_m, ky_m):
      	tmp = 0
      	if math.sqrt((1.0 + (math.pow(((2.0 * l) / Om), 2.0) * (math.pow(math.sin(kx_m), 2.0) + math.pow(math.sin(ky_m), 2.0))))) <= 2.0:
      		tmp = 1.0
      	else:
      		tmp = math.sqrt(0.5)
      	return tmp
      
      kx_m = abs(kx)
      ky_m = abs(ky)
      l, Om, kx_m, ky_m = sort([l, Om, kx_m, ky_m])
      function code(l, Om, kx_m, ky_m)
      	tmp = 0.0
      	if (sqrt(Float64(1.0 + Float64((Float64(Float64(2.0 * l) / Om) ^ 2.0) * Float64((sin(kx_m) ^ 2.0) + (sin(ky_m) ^ 2.0))))) <= 2.0)
      		tmp = 1.0;
      	else
      		tmp = sqrt(0.5);
      	end
      	return tmp
      end
      
      kx_m = abs(kx);
      ky_m = abs(ky);
      l, Om, kx_m, ky_m = num2cell(sort([l, Om, kx_m, ky_m])){:}
      function tmp_2 = code(l, Om, kx_m, ky_m)
      	tmp = 0.0;
      	if (sqrt((1.0 + ((((2.0 * l) / Om) ^ 2.0) * ((sin(kx_m) ^ 2.0) + (sin(ky_m) ^ 2.0))))) <= 2.0)
      		tmp = 1.0;
      	else
      		tmp = sqrt(0.5);
      	end
      	tmp_2 = tmp;
      end
      
      kx_m = N[Abs[kx], $MachinePrecision]
      ky_m = N[Abs[ky], $MachinePrecision]
      NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
      code[l_, Om_, kx$95$m_, ky$95$m_] := If[LessEqual[N[Sqrt[N[(1.0 + N[(N[Power[N[(N[(2.0 * l), $MachinePrecision] / Om), $MachinePrecision], 2.0], $MachinePrecision] * N[(N[Power[N[Sin[kx$95$m], $MachinePrecision], 2.0], $MachinePrecision] + N[Power[N[Sin[ky$95$m], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], 2.0], 1.0, N[Sqrt[0.5], $MachinePrecision]]
      
      \begin{array}{l}
      kx_m = \left|kx\right|
      \\
      ky_m = \left|ky\right|
      \\
      [l, Om, kx_m, ky_m] = \mathsf{sort}([l, Om, kx_m, ky_m])\\
      \\
      \begin{array}{l}
      \mathbf{if}\;\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx\_m}^{2} + {\sin ky\_m}^{2}\right)} \leq 2:\\
      \;\;\;\;1\\
      
      \mathbf{else}:\\
      \;\;\;\;\sqrt{0.5}\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (sqrt.f64 (+.f64 #s(literal 1 binary64) (*.f64 (pow.f64 (/.f64 (*.f64 #s(literal 2 binary64) l) Om) #s(literal 2 binary64)) (+.f64 (pow.f64 (sin.f64 kx) #s(literal 2 binary64)) (pow.f64 (sin.f64 ky) #s(literal 2 binary64)))))) < 2

        1. Initial program 100.0%

          \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
        2. Add Preprocessing
        3. Taylor expanded in l around 0

          \[\leadsto \color{blue}{\sqrt{\frac{1}{2}} \cdot \sqrt{2}} \]
        4. Step-by-step derivation
          1. metadata-evalN/A

            \[\leadsto \sqrt{\frac{1}{2}} \cdot \sqrt{2} \]
          2. sqrt-unprodN/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot 2} \]
          3. metadata-evalN/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot 2} \]
          4. metadata-evalN/A

            \[\leadsto \sqrt{1} \]
          5. metadata-eval98.6

            \[\leadsto 1 \]
        5. Applied rewrites98.6%

          \[\leadsto \color{blue}{1} \]

        if 2 < (sqrt.f64 (+.f64 #s(literal 1 binary64) (*.f64 (pow.f64 (/.f64 (*.f64 #s(literal 2 binary64) l) Om) #s(literal 2 binary64)) (+.f64 (pow.f64 (sin.f64 kx) #s(literal 2 binary64)) (pow.f64 (sin.f64 ky) #s(literal 2 binary64))))))

        1. Initial program 96.6%

          \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
        2. Add Preprocessing
        3. Taylor expanded in l around inf

          \[\leadsto \sqrt{\color{blue}{\frac{1}{2}}} \]
        4. Step-by-step derivation
          1. Applied rewrites99.4%

            \[\leadsto \sqrt{\color{blue}{0.5}} \]
        5. Recombined 2 regimes into one program.
        6. Add Preprocessing

        Alternative 4: 61.8% accurate, 581.0× speedup?

        \[\begin{array}{l} kx_m = \left|kx\right| \\ ky_m = \left|ky\right| \\ [l, Om, kx_m, ky_m] = \mathsf{sort}([l, Om, kx_m, ky_m])\\ \\ 1 \end{array} \]
        kx_m = (fabs.f64 kx)
        ky_m = (fabs.f64 ky)
        NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
        (FPCore (l Om kx_m ky_m) :precision binary64 1.0)
        kx_m = fabs(kx);
        ky_m = fabs(ky);
        assert(l < Om && Om < kx_m && kx_m < ky_m);
        double code(double l, double Om, double kx_m, double ky_m) {
        	return 1.0;
        }
        
        kx_m =     private
        ky_m =     private
        NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
        module fmin_fmax_functions
            implicit none
            private
            public fmax
            public fmin
        
            interface fmax
                module procedure fmax88
                module procedure fmax44
                module procedure fmax84
                module procedure fmax48
            end interface
            interface fmin
                module procedure fmin88
                module procedure fmin44
                module procedure fmin84
                module procedure fmin48
            end interface
        contains
            real(8) function fmax88(x, y) result (res)
                real(8), intent (in) :: x
                real(8), intent (in) :: y
                res = merge(y, merge(x, max(x, y), y /= y), x /= x)
            end function
            real(4) function fmax44(x, y) result (res)
                real(4), intent (in) :: x
                real(4), intent (in) :: y
                res = merge(y, merge(x, max(x, y), y /= y), x /= x)
            end function
            real(8) function fmax84(x, y) result(res)
                real(8), intent (in) :: x
                real(4), intent (in) :: y
                res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
            end function
            real(8) function fmax48(x, y) result(res)
                real(4), intent (in) :: x
                real(8), intent (in) :: y
                res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
            end function
            real(8) function fmin88(x, y) result (res)
                real(8), intent (in) :: x
                real(8), intent (in) :: y
                res = merge(y, merge(x, min(x, y), y /= y), x /= x)
            end function
            real(4) function fmin44(x, y) result (res)
                real(4), intent (in) :: x
                real(4), intent (in) :: y
                res = merge(y, merge(x, min(x, y), y /= y), x /= x)
            end function
            real(8) function fmin84(x, y) result(res)
                real(8), intent (in) :: x
                real(4), intent (in) :: y
                res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
            end function
            real(8) function fmin48(x, y) result(res)
                real(4), intent (in) :: x
                real(8), intent (in) :: y
                res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
            end function
        end module
        
        real(8) function code(l, om, kx_m, ky_m)
        use fmin_fmax_functions
            real(8), intent (in) :: l
            real(8), intent (in) :: om
            real(8), intent (in) :: kx_m
            real(8), intent (in) :: ky_m
            code = 1.0d0
        end function
        
        kx_m = Math.abs(kx);
        ky_m = Math.abs(ky);
        assert l < Om && Om < kx_m && kx_m < ky_m;
        public static double code(double l, double Om, double kx_m, double ky_m) {
        	return 1.0;
        }
        
        kx_m = math.fabs(kx)
        ky_m = math.fabs(ky)
        [l, Om, kx_m, ky_m] = sort([l, Om, kx_m, ky_m])
        def code(l, Om, kx_m, ky_m):
        	return 1.0
        
        kx_m = abs(kx)
        ky_m = abs(ky)
        l, Om, kx_m, ky_m = sort([l, Om, kx_m, ky_m])
        function code(l, Om, kx_m, ky_m)
        	return 1.0
        end
        
        kx_m = abs(kx);
        ky_m = abs(ky);
        l, Om, kx_m, ky_m = num2cell(sort([l, Om, kx_m, ky_m])){:}
        function tmp = code(l, Om, kx_m, ky_m)
        	tmp = 1.0;
        end
        
        kx_m = N[Abs[kx], $MachinePrecision]
        ky_m = N[Abs[ky], $MachinePrecision]
        NOTE: l, Om, kx_m, and ky_m should be sorted in increasing order before calling this function.
        code[l_, Om_, kx$95$m_, ky$95$m_] := 1.0
        
        \begin{array}{l}
        kx_m = \left|kx\right|
        \\
        ky_m = \left|ky\right|
        \\
        [l, Om, kx_m, ky_m] = \mathsf{sort}([l, Om, kx_m, ky_m])\\
        \\
        1
        \end{array}
        
        Derivation
        1. Initial program 98.4%

          \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
        2. Add Preprocessing
        3. Taylor expanded in l around 0

          \[\leadsto \color{blue}{\sqrt{\frac{1}{2}} \cdot \sqrt{2}} \]
        4. Step-by-step derivation
          1. metadata-evalN/A

            \[\leadsto \sqrt{\frac{1}{2}} \cdot \sqrt{2} \]
          2. sqrt-unprodN/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot 2} \]
          3. metadata-evalN/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot 2} \]
          4. metadata-evalN/A

            \[\leadsto \sqrt{1} \]
          5. metadata-eval62.7

            \[\leadsto 1 \]
        5. Applied rewrites62.7%

          \[\leadsto \color{blue}{1} \]
        6. Add Preprocessing

        Reproduce

        ?
        herbie shell --seed 2025037 
        (FPCore (l Om kx ky)
          :name "Toniolo and Linder, Equation (3a)"
          :precision binary64
          (sqrt (* (/ 1.0 2.0) (+ 1.0 (/ 1.0 (sqrt (+ 1.0 (* (pow (/ (* 2.0 l) Om) 2.0) (+ (pow (sin kx) 2.0) (pow (sin ky) 2.0))))))))))