Migdal et al, Equation (64)

Percentage Accurate: 99.5% → 99.6%
Time: 10.8s
Alternatives: 10
Speedup: 1.9×

Specification

?
\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{\cos th}{\sqrt{2}}\\ t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right) \end{array} \end{array} \]
(FPCore (a1 a2 th)
 :precision binary64
 (let* ((t_1 (/ (cos th) (sqrt 2.0))))
   (+ (* t_1 (* a1 a1)) (* t_1 (* a2 a2)))))
double code(double a1, double a2, double th) {
	double t_1 = cos(th) / sqrt(2.0);
	return (t_1 * (a1 * a1)) + (t_1 * (a2 * a2));
}
real(8) function code(a1, a2, th)
    real(8), intent (in) :: a1
    real(8), intent (in) :: a2
    real(8), intent (in) :: th
    real(8) :: t_1
    t_1 = cos(th) / sqrt(2.0d0)
    code = (t_1 * (a1 * a1)) + (t_1 * (a2 * a2))
end function
public static double code(double a1, double a2, double th) {
	double t_1 = Math.cos(th) / Math.sqrt(2.0);
	return (t_1 * (a1 * a1)) + (t_1 * (a2 * a2));
}
def code(a1, a2, th):
	t_1 = math.cos(th) / math.sqrt(2.0)
	return (t_1 * (a1 * a1)) + (t_1 * (a2 * a2))
function code(a1, a2, th)
	t_1 = Float64(cos(th) / sqrt(2.0))
	return Float64(Float64(t_1 * Float64(a1 * a1)) + Float64(t_1 * Float64(a2 * a2)))
end
function tmp = code(a1, a2, th)
	t_1 = cos(th) / sqrt(2.0);
	tmp = (t_1 * (a1 * a1)) + (t_1 * (a2 * a2));
end
code[a1_, a2_, th_] := Block[{t$95$1 = N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]}, N[(N[(t$95$1 * N[(a1 * a1), $MachinePrecision]), $MachinePrecision] + N[(t$95$1 * N[(a2 * a2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{\cos th}{\sqrt{2}}\\
t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right)
\end{array}
\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 10 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: 99.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{\cos th}{\sqrt{2}}\\ t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right) \end{array} \end{array} \]
(FPCore (a1 a2 th)
 :precision binary64
 (let* ((t_1 (/ (cos th) (sqrt 2.0))))
   (+ (* t_1 (* a1 a1)) (* t_1 (* a2 a2)))))
double code(double a1, double a2, double th) {
	double t_1 = cos(th) / sqrt(2.0);
	return (t_1 * (a1 * a1)) + (t_1 * (a2 * a2));
}
real(8) function code(a1, a2, th)
    real(8), intent (in) :: a1
    real(8), intent (in) :: a2
    real(8), intent (in) :: th
    real(8) :: t_1
    t_1 = cos(th) / sqrt(2.0d0)
    code = (t_1 * (a1 * a1)) + (t_1 * (a2 * a2))
end function
public static double code(double a1, double a2, double th) {
	double t_1 = Math.cos(th) / Math.sqrt(2.0);
	return (t_1 * (a1 * a1)) + (t_1 * (a2 * a2));
}
def code(a1, a2, th):
	t_1 = math.cos(th) / math.sqrt(2.0)
	return (t_1 * (a1 * a1)) + (t_1 * (a2 * a2))
function code(a1, a2, th)
	t_1 = Float64(cos(th) / sqrt(2.0))
	return Float64(Float64(t_1 * Float64(a1 * a1)) + Float64(t_1 * Float64(a2 * a2)))
end
function tmp = code(a1, a2, th)
	t_1 = cos(th) / sqrt(2.0);
	tmp = (t_1 * (a1 * a1)) + (t_1 * (a2 * a2));
end
code[a1_, a2_, th_] := Block[{t$95$1 = N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]}, N[(N[(t$95$1 * N[(a1 * a1), $MachinePrecision]), $MachinePrecision] + N[(t$95$1 * N[(a2 * a2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{\cos th}{\sqrt{2}}\\
t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right)
\end{array}
\end{array}

Alternative 1: 99.6% accurate, 1.8× speedup?

\[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \frac{\mathsf{fma}\left(a2, a2, a1\_m \cdot a1\_m\right)}{\frac{\sqrt{2}}{\cos th}} \end{array} \]
a1_m = (fabs.f64 a1)
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
(FPCore (a1_m a2 th)
 :precision binary64
 (/ (fma a2 a2 (* a1_m a1_m)) (/ (sqrt 2.0) (cos th))))
a1_m = fabs(a1);
assert(a1_m < a2 && a2 < th);
double code(double a1_m, double a2, double th) {
	return fma(a2, a2, (a1_m * a1_m)) / (sqrt(2.0) / cos(th));
}
a1_m = abs(a1)
a1_m, a2, th = sort([a1_m, a2, th])
function code(a1_m, a2, th)
	return Float64(fma(a2, a2, Float64(a1_m * a1_m)) / Float64(sqrt(2.0) / cos(th)))
end
a1_m = N[Abs[a1], $MachinePrecision]
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
code[a1$95$m_, a2_, th_] := N[(N[(a2 * a2 + N[(a1$95$m * a1$95$m), $MachinePrecision]), $MachinePrecision] / N[(N[Sqrt[2.0], $MachinePrecision] / N[Cos[th], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
a1_m = \left|a1\right|
\\
[a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
\\
\frac{\mathsf{fma}\left(a2, a2, a1\_m \cdot a1\_m\right)}{\frac{\sqrt{2}}{\cos th}}
\end{array}
Derivation
  1. Initial program 99.6%

    \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-cos.f64N/A

      \[\leadsto \frac{\color{blue}{\cos th}}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    2. lift-sqrt.f64N/A

      \[\leadsto \frac{\cos th}{\color{blue}{\sqrt{2}}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    3. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    4. lift-*.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \color{blue}{\left(a1 \cdot a1\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    5. lift-cos.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\color{blue}{\cos th}}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    6. lift-sqrt.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\color{blue}{\sqrt{2}}} \cdot \left(a2 \cdot a2\right) \]
    7. lift-/.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a2 \cdot a2\right) \]
    8. lift-*.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \color{blue}{\left(a2 \cdot a2\right)} \]
    9. distribute-lft-outN/A

      \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
    10. *-commutativeN/A

      \[\leadsto \color{blue}{\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \frac{\cos th}{\sqrt{2}}} \]
    11. lift-/.f64N/A

      \[\leadsto \left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \color{blue}{\frac{\cos th}{\sqrt{2}}} \]
    12. clear-numN/A

      \[\leadsto \left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \color{blue}{\frac{1}{\frac{\sqrt{2}}{\cos th}}} \]
    13. un-div-invN/A

      \[\leadsto \color{blue}{\frac{a1 \cdot a1 + a2 \cdot a2}{\frac{\sqrt{2}}{\cos th}}} \]
    14. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{a1 \cdot a1 + a2 \cdot a2}{\frac{\sqrt{2}}{\cos th}}} \]
    15. lift-*.f64N/A

      \[\leadsto \frac{\color{blue}{a1 \cdot a1} + a2 \cdot a2}{\frac{\sqrt{2}}{\cos th}} \]
    16. lower-fma.f64N/A

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}}{\frac{\sqrt{2}}{\cos th}} \]
    17. lower-/.f6499.6

      \[\leadsto \frac{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}{\color{blue}{\frac{\sqrt{2}}{\cos th}}} \]
  4. Applied egg-rr99.6%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}{\frac{\sqrt{2}}{\cos th}}} \]
  5. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \frac{a1 \cdot a1 + \color{blue}{a2 \cdot a2}}{\frac{\sqrt{2}}{\cos th}} \]
    2. lift-*.f64N/A

      \[\leadsto \frac{\color{blue}{a1 \cdot a1} + a2 \cdot a2}{\frac{\sqrt{2}}{\cos th}} \]
    3. +-commutativeN/A

      \[\leadsto \frac{\color{blue}{a2 \cdot a2 + a1 \cdot a1}}{\frac{\sqrt{2}}{\cos th}} \]
    4. lift-*.f64N/A

      \[\leadsto \frac{\color{blue}{a2 \cdot a2} + a1 \cdot a1}{\frac{\sqrt{2}}{\cos th}} \]
    5. lower-fma.f6499.6

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}}{\frac{\sqrt{2}}{\cos th}} \]
  6. Applied egg-rr99.6%

    \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}}{\frac{\sqrt{2}}{\cos th}} \]
  7. Add Preprocessing

Alternative 2: 76.0% accurate, 0.8× speedup?

\[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \begin{array}{l} t_1 := \frac{\cos th}{\sqrt{2}}\\ \mathbf{if}\;\left(a1\_m \cdot a1\_m\right) \cdot t\_1 + \left(a2 \cdot a2\right) \cdot t\_1 \leq -1 \cdot 10^{-306}:\\ \;\;\;\;\left(a2 \cdot a2\right) \cdot \mathsf{fma}\left(a1\_m, \frac{a1\_m}{a2 \cdot \left(a2 \cdot \sqrt{2}\right)}, \frac{-1}{\sqrt{2}}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(a1\_m, a1\_m, a2 \cdot a2\right)}{\sqrt{2}}\\ \end{array} \end{array} \]
a1_m = (fabs.f64 a1)
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
(FPCore (a1_m a2 th)
 :precision binary64
 (let* ((t_1 (/ (cos th) (sqrt 2.0))))
   (if (<= (+ (* (* a1_m a1_m) t_1) (* (* a2 a2) t_1)) -1e-306)
     (*
      (* a2 a2)
      (fma a1_m (/ a1_m (* a2 (* a2 (sqrt 2.0)))) (/ -1.0 (sqrt 2.0))))
     (/ (fma a1_m a1_m (* a2 a2)) (sqrt 2.0)))))
a1_m = fabs(a1);
assert(a1_m < a2 && a2 < th);
double code(double a1_m, double a2, double th) {
	double t_1 = cos(th) / sqrt(2.0);
	double tmp;
	if ((((a1_m * a1_m) * t_1) + ((a2 * a2) * t_1)) <= -1e-306) {
		tmp = (a2 * a2) * fma(a1_m, (a1_m / (a2 * (a2 * sqrt(2.0)))), (-1.0 / sqrt(2.0)));
	} else {
		tmp = fma(a1_m, a1_m, (a2 * a2)) / sqrt(2.0);
	}
	return tmp;
}
a1_m = abs(a1)
a1_m, a2, th = sort([a1_m, a2, th])
function code(a1_m, a2, th)
	t_1 = Float64(cos(th) / sqrt(2.0))
	tmp = 0.0
	if (Float64(Float64(Float64(a1_m * a1_m) * t_1) + Float64(Float64(a2 * a2) * t_1)) <= -1e-306)
		tmp = Float64(Float64(a2 * a2) * fma(a1_m, Float64(a1_m / Float64(a2 * Float64(a2 * sqrt(2.0)))), Float64(-1.0 / sqrt(2.0))));
	else
		tmp = Float64(fma(a1_m, a1_m, Float64(a2 * a2)) / sqrt(2.0));
	end
	return tmp
end
a1_m = N[Abs[a1], $MachinePrecision]
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
code[a1$95$m_, a2_, th_] := Block[{t$95$1 = N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(N[(a1$95$m * a1$95$m), $MachinePrecision] * t$95$1), $MachinePrecision] + N[(N[(a2 * a2), $MachinePrecision] * t$95$1), $MachinePrecision]), $MachinePrecision], -1e-306], N[(N[(a2 * a2), $MachinePrecision] * N[(a1$95$m * N[(a1$95$m / N[(a2 * N[(a2 * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-1.0 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(a1$95$m * a1$95$m + N[(a2 * a2), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
a1_m = \left|a1\right|
\\
[a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
\\
\begin{array}{l}
t_1 := \frac{\cos th}{\sqrt{2}}\\
\mathbf{if}\;\left(a1\_m \cdot a1\_m\right) \cdot t\_1 + \left(a2 \cdot a2\right) \cdot t\_1 \leq -1 \cdot 10^{-306}:\\
\;\;\;\;\left(a2 \cdot a2\right) \cdot \mathsf{fma}\left(a1\_m, \frac{a1\_m}{a2 \cdot \left(a2 \cdot \sqrt{2}\right)}, \frac{-1}{\sqrt{2}}\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{\mathsf{fma}\left(a1\_m, a1\_m, a2 \cdot a2\right)}{\sqrt{2}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a1 a1)) (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a2 a2))) < -1.00000000000000003e-306

    1. Initial program 99.5%

      \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    2. Add Preprocessing
    3. Taylor expanded in th around 0

      \[\leadsto \color{blue}{\frac{{a1}^{3}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}}} \]
    4. Step-by-step derivation
      1. cube-multN/A

        \[\leadsto \frac{\color{blue}{a1 \cdot \left(a1 \cdot a1\right)}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}} \]
      2. unpow2N/A

        \[\leadsto \frac{a1 \cdot \color{blue}{{a1}^{2}}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}} \]
      3. associate-/l*N/A

        \[\leadsto \color{blue}{a1 \cdot \frac{{a1}^{2}}{\sqrt{2}}} + \frac{{a2}^{3}}{\sqrt{2}} \]
      4. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(a1, \frac{{a1}^{2}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right)} \]
      5. lower-/.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \color{blue}{\frac{{a1}^{2}}{\sqrt{2}}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
      6. unpow2N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{\color{blue}{a1 \cdot a1}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
      7. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{\color{blue}{a1 \cdot a1}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
      8. lower-sqrt.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\color{blue}{\sqrt{2}}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
      9. lower-/.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \color{blue}{\frac{{a2}^{3}}{\sqrt{2}}}\right) \]
      10. cube-multN/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{\color{blue}{a2 \cdot \left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
      11. unpow2N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{{a2}^{2}}}{\sqrt{2}}\right) \]
      12. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{\color{blue}{a2 \cdot {a2}^{2}}}{\sqrt{2}}\right) \]
      13. unpow2N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{\left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
      14. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{\left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
      15. lower-sqrt.f6428.7

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \left(a2 \cdot a2\right)}{\color{blue}{\sqrt{2}}}\right) \]
    5. Simplified28.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \left(a2 \cdot a2\right)}{\sqrt{2}}\right)} \]
    6. Taylor expanded in a2 around -inf

      \[\leadsto \color{blue}{{a2}^{2} \cdot \left(\frac{{a1}^{2}}{{a2}^{2} \cdot \sqrt{2}} - \frac{1}{\sqrt{2}}\right)} \]
    7. Step-by-step derivation
      1. lower-*.f64N/A

        \[\leadsto \color{blue}{{a2}^{2} \cdot \left(\frac{{a1}^{2}}{{a2}^{2} \cdot \sqrt{2}} - \frac{1}{\sqrt{2}}\right)} \]
      2. unpow2N/A

        \[\leadsto \color{blue}{\left(a2 \cdot a2\right)} \cdot \left(\frac{{a1}^{2}}{{a2}^{2} \cdot \sqrt{2}} - \frac{1}{\sqrt{2}}\right) \]
      3. lower-*.f64N/A

        \[\leadsto \color{blue}{\left(a2 \cdot a2\right)} \cdot \left(\frac{{a1}^{2}}{{a2}^{2} \cdot \sqrt{2}} - \frac{1}{\sqrt{2}}\right) \]
      4. sub-negN/A

        \[\leadsto \left(a2 \cdot a2\right) \cdot \color{blue}{\left(\frac{{a1}^{2}}{{a2}^{2} \cdot \sqrt{2}} + \left(\mathsf{neg}\left(\frac{1}{\sqrt{2}}\right)\right)\right)} \]
      5. unpow2N/A

        \[\leadsto \left(a2 \cdot a2\right) \cdot \left(\frac{\color{blue}{a1 \cdot a1}}{{a2}^{2} \cdot \sqrt{2}} + \left(\mathsf{neg}\left(\frac{1}{\sqrt{2}}\right)\right)\right) \]
      6. associate-/l*N/A

        \[\leadsto \left(a2 \cdot a2\right) \cdot \left(\color{blue}{a1 \cdot \frac{a1}{{a2}^{2} \cdot \sqrt{2}}} + \left(\mathsf{neg}\left(\frac{1}{\sqrt{2}}\right)\right)\right) \]
      7. distribute-neg-fracN/A

        \[\leadsto \left(a2 \cdot a2\right) \cdot \left(a1 \cdot \frac{a1}{{a2}^{2} \cdot \sqrt{2}} + \color{blue}{\frac{\mathsf{neg}\left(1\right)}{\sqrt{2}}}\right) \]
      8. metadata-evalN/A

        \[\leadsto \left(a2 \cdot a2\right) \cdot \left(a1 \cdot \frac{a1}{{a2}^{2} \cdot \sqrt{2}} + \frac{\color{blue}{-1}}{\sqrt{2}}\right) \]
      9. lower-fma.f64N/A

        \[\leadsto \left(a2 \cdot a2\right) \cdot \color{blue}{\mathsf{fma}\left(a1, \frac{a1}{{a2}^{2} \cdot \sqrt{2}}, \frac{-1}{\sqrt{2}}\right)} \]
      10. lower-/.f64N/A

        \[\leadsto \left(a2 \cdot a2\right) \cdot \mathsf{fma}\left(a1, \color{blue}{\frac{a1}{{a2}^{2} \cdot \sqrt{2}}}, \frac{-1}{\sqrt{2}}\right) \]
      11. unpow2N/A

        \[\leadsto \left(a2 \cdot a2\right) \cdot \mathsf{fma}\left(a1, \frac{a1}{\color{blue}{\left(a2 \cdot a2\right)} \cdot \sqrt{2}}, \frac{-1}{\sqrt{2}}\right) \]
      12. associate-*l*N/A

        \[\leadsto \left(a2 \cdot a2\right) \cdot \mathsf{fma}\left(a1, \frac{a1}{\color{blue}{a2 \cdot \left(a2 \cdot \sqrt{2}\right)}}, \frac{-1}{\sqrt{2}}\right) \]
      13. lower-*.f64N/A

        \[\leadsto \left(a2 \cdot a2\right) \cdot \mathsf{fma}\left(a1, \frac{a1}{\color{blue}{a2 \cdot \left(a2 \cdot \sqrt{2}\right)}}, \frac{-1}{\sqrt{2}}\right) \]
      14. lower-*.f64N/A

        \[\leadsto \left(a2 \cdot a2\right) \cdot \mathsf{fma}\left(a1, \frac{a1}{a2 \cdot \color{blue}{\left(a2 \cdot \sqrt{2}\right)}}, \frac{-1}{\sqrt{2}}\right) \]
      15. lower-sqrt.f64N/A

        \[\leadsto \left(a2 \cdot a2\right) \cdot \mathsf{fma}\left(a1, \frac{a1}{a2 \cdot \left(a2 \cdot \color{blue}{\sqrt{2}}\right)}, \frac{-1}{\sqrt{2}}\right) \]
      16. lower-/.f64N/A

        \[\leadsto \left(a2 \cdot a2\right) \cdot \mathsf{fma}\left(a1, \frac{a1}{a2 \cdot \left(a2 \cdot \sqrt{2}\right)}, \color{blue}{\frac{-1}{\sqrt{2}}}\right) \]
      17. lower-sqrt.f6427.2

        \[\leadsto \left(a2 \cdot a2\right) \cdot \mathsf{fma}\left(a1, \frac{a1}{a2 \cdot \left(a2 \cdot \sqrt{2}\right)}, \frac{-1}{\color{blue}{\sqrt{2}}}\right) \]
    8. Simplified27.2%

      \[\leadsto \color{blue}{\left(a2 \cdot a2\right) \cdot \mathsf{fma}\left(a1, \frac{a1}{a2 \cdot \left(a2 \cdot \sqrt{2}\right)}, \frac{-1}{\sqrt{2}}\right)} \]

    if -1.00000000000000003e-306 < (+.f64 (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a1 a1)) (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a2 a2)))

    1. Initial program 99.6%

      \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-cos.f64N/A

        \[\leadsto \frac{\color{blue}{\cos th}}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      2. lift-sqrt.f64N/A

        \[\leadsto \frac{\cos th}{\color{blue}{\sqrt{2}}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      3. lift-/.f64N/A

        \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      4. lift-*.f64N/A

        \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \color{blue}{\left(a1 \cdot a1\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      5. lift-cos.f64N/A

        \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\color{blue}{\cos th}}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      6. lift-sqrt.f64N/A

        \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\color{blue}{\sqrt{2}}} \cdot \left(a2 \cdot a2\right) \]
      7. lift-/.f64N/A

        \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a2 \cdot a2\right) \]
      8. lift-*.f64N/A

        \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \color{blue}{\left(a2 \cdot a2\right)} \]
      9. distribute-lft-outN/A

        \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
      10. *-commutativeN/A

        \[\leadsto \color{blue}{\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \frac{\cos th}{\sqrt{2}}} \]
      11. lift-/.f64N/A

        \[\leadsto \left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \color{blue}{\frac{\cos th}{\sqrt{2}}} \]
      12. clear-numN/A

        \[\leadsto \left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \color{blue}{\frac{1}{\frac{\sqrt{2}}{\cos th}}} \]
      13. un-div-invN/A

        \[\leadsto \color{blue}{\frac{a1 \cdot a1 + a2 \cdot a2}{\frac{\sqrt{2}}{\cos th}}} \]
      14. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{a1 \cdot a1 + a2 \cdot a2}{\frac{\sqrt{2}}{\cos th}}} \]
      15. lift-*.f64N/A

        \[\leadsto \frac{\color{blue}{a1 \cdot a1} + a2 \cdot a2}{\frac{\sqrt{2}}{\cos th}} \]
      16. lower-fma.f64N/A

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}}{\frac{\sqrt{2}}{\cos th}} \]
      17. lower-/.f6499.7

        \[\leadsto \frac{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}{\color{blue}{\frac{\sqrt{2}}{\cos th}}} \]
    4. Applied egg-rr99.7%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}{\frac{\sqrt{2}}{\cos th}}} \]
    5. Taylor expanded in th around 0

      \[\leadsto \frac{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}{\color{blue}{\sqrt{2}}} \]
    6. Step-by-step derivation
      1. lower-sqrt.f6484.5

        \[\leadsto \frac{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}{\color{blue}{\sqrt{2}}} \]
    7. Simplified84.5%

      \[\leadsto \frac{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}{\color{blue}{\sqrt{2}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification67.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(a1 \cdot a1\right) \cdot \frac{\cos th}{\sqrt{2}} + \left(a2 \cdot a2\right) \cdot \frac{\cos th}{\sqrt{2}} \leq -1 \cdot 10^{-306}:\\ \;\;\;\;\left(a2 \cdot a2\right) \cdot \mathsf{fma}\left(a1, \frac{a1}{a2 \cdot \left(a2 \cdot \sqrt{2}\right)}, \frac{-1}{\sqrt{2}}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}{\sqrt{2}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 76.2% accurate, 0.9× speedup?

\[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \begin{array}{l} t_1 := \frac{\cos th}{\sqrt{2}}\\ \mathbf{if}\;\left(a1\_m \cdot a1\_m\right) \cdot t\_1 + \left(a2 \cdot a2\right) \cdot t\_1 \leq -1 \cdot 10^{-306}:\\ \;\;\;\;-\frac{a2 \cdot a2}{\sqrt{2}}\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(a1\_m, a1\_m, a2 \cdot a2\right)}{\sqrt{2}}\\ \end{array} \end{array} \]
a1_m = (fabs.f64 a1)
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
(FPCore (a1_m a2 th)
 :precision binary64
 (let* ((t_1 (/ (cos th) (sqrt 2.0))))
   (if (<= (+ (* (* a1_m a1_m) t_1) (* (* a2 a2) t_1)) -1e-306)
     (- (/ (* a2 a2) (sqrt 2.0)))
     (/ (fma a1_m a1_m (* a2 a2)) (sqrt 2.0)))))
a1_m = fabs(a1);
assert(a1_m < a2 && a2 < th);
double code(double a1_m, double a2, double th) {
	double t_1 = cos(th) / sqrt(2.0);
	double tmp;
	if ((((a1_m * a1_m) * t_1) + ((a2 * a2) * t_1)) <= -1e-306) {
		tmp = -((a2 * a2) / sqrt(2.0));
	} else {
		tmp = fma(a1_m, a1_m, (a2 * a2)) / sqrt(2.0);
	}
	return tmp;
}
a1_m = abs(a1)
a1_m, a2, th = sort([a1_m, a2, th])
function code(a1_m, a2, th)
	t_1 = Float64(cos(th) / sqrt(2.0))
	tmp = 0.0
	if (Float64(Float64(Float64(a1_m * a1_m) * t_1) + Float64(Float64(a2 * a2) * t_1)) <= -1e-306)
		tmp = Float64(-Float64(Float64(a2 * a2) / sqrt(2.0)));
	else
		tmp = Float64(fma(a1_m, a1_m, Float64(a2 * a2)) / sqrt(2.0));
	end
	return tmp
end
a1_m = N[Abs[a1], $MachinePrecision]
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
code[a1$95$m_, a2_, th_] := Block[{t$95$1 = N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(N[(a1$95$m * a1$95$m), $MachinePrecision] * t$95$1), $MachinePrecision] + N[(N[(a2 * a2), $MachinePrecision] * t$95$1), $MachinePrecision]), $MachinePrecision], -1e-306], (-N[(N[(a2 * a2), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), N[(N[(a1$95$m * a1$95$m + N[(a2 * a2), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
a1_m = \left|a1\right|
\\
[a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
\\
\begin{array}{l}
t_1 := \frac{\cos th}{\sqrt{2}}\\
\mathbf{if}\;\left(a1\_m \cdot a1\_m\right) \cdot t\_1 + \left(a2 \cdot a2\right) \cdot t\_1 \leq -1 \cdot 10^{-306}:\\
\;\;\;\;-\frac{a2 \cdot a2}{\sqrt{2}}\\

\mathbf{else}:\\
\;\;\;\;\frac{\mathsf{fma}\left(a1\_m, a1\_m, a2 \cdot a2\right)}{\sqrt{2}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a1 a1)) (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a2 a2))) < -1.00000000000000003e-306

    1. Initial program 99.5%

      \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    2. Add Preprocessing
    3. Taylor expanded in th around 0

      \[\leadsto \color{blue}{\frac{{a1}^{3}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}}} \]
    4. Step-by-step derivation
      1. cube-multN/A

        \[\leadsto \frac{\color{blue}{a1 \cdot \left(a1 \cdot a1\right)}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}} \]
      2. unpow2N/A

        \[\leadsto \frac{a1 \cdot \color{blue}{{a1}^{2}}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}} \]
      3. associate-/l*N/A

        \[\leadsto \color{blue}{a1 \cdot \frac{{a1}^{2}}{\sqrt{2}}} + \frac{{a2}^{3}}{\sqrt{2}} \]
      4. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(a1, \frac{{a1}^{2}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right)} \]
      5. lower-/.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \color{blue}{\frac{{a1}^{2}}{\sqrt{2}}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
      6. unpow2N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{\color{blue}{a1 \cdot a1}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
      7. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{\color{blue}{a1 \cdot a1}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
      8. lower-sqrt.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\color{blue}{\sqrt{2}}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
      9. lower-/.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \color{blue}{\frac{{a2}^{3}}{\sqrt{2}}}\right) \]
      10. cube-multN/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{\color{blue}{a2 \cdot \left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
      11. unpow2N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{{a2}^{2}}}{\sqrt{2}}\right) \]
      12. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{\color{blue}{a2 \cdot {a2}^{2}}}{\sqrt{2}}\right) \]
      13. unpow2N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{\left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
      14. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{\left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
      15. lower-sqrt.f6428.7

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \left(a2 \cdot a2\right)}{\color{blue}{\sqrt{2}}}\right) \]
    5. Simplified28.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \left(a2 \cdot a2\right)}{\sqrt{2}}\right)} \]
    6. Taylor expanded in a2 around -inf

      \[\leadsto \color{blue}{-1 \cdot \frac{{a2}^{2}}{\sqrt{2}}} \]
    7. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \color{blue}{\mathsf{neg}\left(\frac{{a2}^{2}}{\sqrt{2}}\right)} \]
      2. distribute-neg-frac2N/A

        \[\leadsto \color{blue}{\frac{{a2}^{2}}{\mathsf{neg}\left(\sqrt{2}\right)}} \]
      3. mul-1-negN/A

        \[\leadsto \frac{{a2}^{2}}{\color{blue}{-1 \cdot \sqrt{2}}} \]
      4. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{{a2}^{2}}{-1 \cdot \sqrt{2}}} \]
      5. unpow2N/A

        \[\leadsto \frac{\color{blue}{a2 \cdot a2}}{-1 \cdot \sqrt{2}} \]
      6. lower-*.f64N/A

        \[\leadsto \frac{\color{blue}{a2 \cdot a2}}{-1 \cdot \sqrt{2}} \]
      7. mul-1-negN/A

        \[\leadsto \frac{a2 \cdot a2}{\color{blue}{\mathsf{neg}\left(\sqrt{2}\right)}} \]
      8. lower-neg.f64N/A

        \[\leadsto \frac{a2 \cdot a2}{\color{blue}{\mathsf{neg}\left(\sqrt{2}\right)}} \]
      9. lower-sqrt.f6428.7

        \[\leadsto \frac{a2 \cdot a2}{-\color{blue}{\sqrt{2}}} \]
    8. Simplified28.7%

      \[\leadsto \color{blue}{\frac{a2 \cdot a2}{-\sqrt{2}}} \]

    if -1.00000000000000003e-306 < (+.f64 (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a1 a1)) (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a2 a2)))

    1. Initial program 99.6%

      \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-cos.f64N/A

        \[\leadsto \frac{\color{blue}{\cos th}}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      2. lift-sqrt.f64N/A

        \[\leadsto \frac{\cos th}{\color{blue}{\sqrt{2}}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      3. lift-/.f64N/A

        \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      4. lift-*.f64N/A

        \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \color{blue}{\left(a1 \cdot a1\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      5. lift-cos.f64N/A

        \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\color{blue}{\cos th}}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      6. lift-sqrt.f64N/A

        \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\color{blue}{\sqrt{2}}} \cdot \left(a2 \cdot a2\right) \]
      7. lift-/.f64N/A

        \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a2 \cdot a2\right) \]
      8. lift-*.f64N/A

        \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \color{blue}{\left(a2 \cdot a2\right)} \]
      9. distribute-lft-outN/A

        \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
      10. *-commutativeN/A

        \[\leadsto \color{blue}{\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \frac{\cos th}{\sqrt{2}}} \]
      11. lift-/.f64N/A

        \[\leadsto \left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \color{blue}{\frac{\cos th}{\sqrt{2}}} \]
      12. clear-numN/A

        \[\leadsto \left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \color{blue}{\frac{1}{\frac{\sqrt{2}}{\cos th}}} \]
      13. un-div-invN/A

        \[\leadsto \color{blue}{\frac{a1 \cdot a1 + a2 \cdot a2}{\frac{\sqrt{2}}{\cos th}}} \]
      14. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{a1 \cdot a1 + a2 \cdot a2}{\frac{\sqrt{2}}{\cos th}}} \]
      15. lift-*.f64N/A

        \[\leadsto \frac{\color{blue}{a1 \cdot a1} + a2 \cdot a2}{\frac{\sqrt{2}}{\cos th}} \]
      16. lower-fma.f64N/A

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}}{\frac{\sqrt{2}}{\cos th}} \]
      17. lower-/.f6499.7

        \[\leadsto \frac{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}{\color{blue}{\frac{\sqrt{2}}{\cos th}}} \]
    4. Applied egg-rr99.7%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}{\frac{\sqrt{2}}{\cos th}}} \]
    5. Taylor expanded in th around 0

      \[\leadsto \frac{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}{\color{blue}{\sqrt{2}}} \]
    6. Step-by-step derivation
      1. lower-sqrt.f6484.5

        \[\leadsto \frac{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}{\color{blue}{\sqrt{2}}} \]
    7. Simplified84.5%

      \[\leadsto \frac{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}{\color{blue}{\sqrt{2}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification67.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(a1 \cdot a1\right) \cdot \frac{\cos th}{\sqrt{2}} + \left(a2 \cdot a2\right) \cdot \frac{\cos th}{\sqrt{2}} \leq -1 \cdot 10^{-306}:\\ \;\;\;\;-\frac{a2 \cdot a2}{\sqrt{2}}\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}{\sqrt{2}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 62.2% accurate, 0.9× speedup?

\[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \begin{array}{l} t_1 := \frac{a2 \cdot a2}{\sqrt{2}}\\ t_2 := \frac{\cos th}{\sqrt{2}}\\ \mathbf{if}\;\left(a1\_m \cdot a1\_m\right) \cdot t\_2 + \left(a2 \cdot a2\right) \cdot t\_2 \leq -1 \cdot 10^{-306}:\\ \;\;\;\;-t\_1\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
a1_m = (fabs.f64 a1)
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
(FPCore (a1_m a2 th)
 :precision binary64
 (let* ((t_1 (/ (* a2 a2) (sqrt 2.0))) (t_2 (/ (cos th) (sqrt 2.0))))
   (if (<= (+ (* (* a1_m a1_m) t_2) (* (* a2 a2) t_2)) -1e-306) (- t_1) t_1)))
a1_m = fabs(a1);
assert(a1_m < a2 && a2 < th);
double code(double a1_m, double a2, double th) {
	double t_1 = (a2 * a2) / sqrt(2.0);
	double t_2 = cos(th) / sqrt(2.0);
	double tmp;
	if ((((a1_m * a1_m) * t_2) + ((a2 * a2) * t_2)) <= -1e-306) {
		tmp = -t_1;
	} else {
		tmp = t_1;
	}
	return tmp;
}
a1_m = abs(a1)
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
real(8) function code(a1_m, a2, th)
    real(8), intent (in) :: a1_m
    real(8), intent (in) :: a2
    real(8), intent (in) :: th
    real(8) :: t_1
    real(8) :: t_2
    real(8) :: tmp
    t_1 = (a2 * a2) / sqrt(2.0d0)
    t_2 = cos(th) / sqrt(2.0d0)
    if ((((a1_m * a1_m) * t_2) + ((a2 * a2) * t_2)) <= (-1d-306)) then
        tmp = -t_1
    else
        tmp = t_1
    end if
    code = tmp
end function
a1_m = Math.abs(a1);
assert a1_m < a2 && a2 < th;
public static double code(double a1_m, double a2, double th) {
	double t_1 = (a2 * a2) / Math.sqrt(2.0);
	double t_2 = Math.cos(th) / Math.sqrt(2.0);
	double tmp;
	if ((((a1_m * a1_m) * t_2) + ((a2 * a2) * t_2)) <= -1e-306) {
		tmp = -t_1;
	} else {
		tmp = t_1;
	}
	return tmp;
}
a1_m = math.fabs(a1)
[a1_m, a2, th] = sort([a1_m, a2, th])
def code(a1_m, a2, th):
	t_1 = (a2 * a2) / math.sqrt(2.0)
	t_2 = math.cos(th) / math.sqrt(2.0)
	tmp = 0
	if (((a1_m * a1_m) * t_2) + ((a2 * a2) * t_2)) <= -1e-306:
		tmp = -t_1
	else:
		tmp = t_1
	return tmp
a1_m = abs(a1)
a1_m, a2, th = sort([a1_m, a2, th])
function code(a1_m, a2, th)
	t_1 = Float64(Float64(a2 * a2) / sqrt(2.0))
	t_2 = Float64(cos(th) / sqrt(2.0))
	tmp = 0.0
	if (Float64(Float64(Float64(a1_m * a1_m) * t_2) + Float64(Float64(a2 * a2) * t_2)) <= -1e-306)
		tmp = Float64(-t_1);
	else
		tmp = t_1;
	end
	return tmp
end
a1_m = abs(a1);
a1_m, a2, th = num2cell(sort([a1_m, a2, th])){:}
function tmp_2 = code(a1_m, a2, th)
	t_1 = (a2 * a2) / sqrt(2.0);
	t_2 = cos(th) / sqrt(2.0);
	tmp = 0.0;
	if ((((a1_m * a1_m) * t_2) + ((a2 * a2) * t_2)) <= -1e-306)
		tmp = -t_1;
	else
		tmp = t_1;
	end
	tmp_2 = tmp;
end
a1_m = N[Abs[a1], $MachinePrecision]
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
code[a1$95$m_, a2_, th_] := Block[{t$95$1 = N[(N[(a2 * a2), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(N[(a1$95$m * a1$95$m), $MachinePrecision] * t$95$2), $MachinePrecision] + N[(N[(a2 * a2), $MachinePrecision] * t$95$2), $MachinePrecision]), $MachinePrecision], -1e-306], (-t$95$1), t$95$1]]]
\begin{array}{l}
a1_m = \left|a1\right|
\\
[a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
\\
\begin{array}{l}
t_1 := \frac{a2 \cdot a2}{\sqrt{2}}\\
t_2 := \frac{\cos th}{\sqrt{2}}\\
\mathbf{if}\;\left(a1\_m \cdot a1\_m\right) \cdot t\_2 + \left(a2 \cdot a2\right) \cdot t\_2 \leq -1 \cdot 10^{-306}:\\
\;\;\;\;-t\_1\\

\mathbf{else}:\\
\;\;\;\;t\_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a1 a1)) (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a2 a2))) < -1.00000000000000003e-306

    1. Initial program 99.5%

      \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    2. Add Preprocessing
    3. Taylor expanded in th around 0

      \[\leadsto \color{blue}{\frac{{a1}^{3}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}}} \]
    4. Step-by-step derivation
      1. cube-multN/A

        \[\leadsto \frac{\color{blue}{a1 \cdot \left(a1 \cdot a1\right)}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}} \]
      2. unpow2N/A

        \[\leadsto \frac{a1 \cdot \color{blue}{{a1}^{2}}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}} \]
      3. associate-/l*N/A

        \[\leadsto \color{blue}{a1 \cdot \frac{{a1}^{2}}{\sqrt{2}}} + \frac{{a2}^{3}}{\sqrt{2}} \]
      4. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(a1, \frac{{a1}^{2}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right)} \]
      5. lower-/.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \color{blue}{\frac{{a1}^{2}}{\sqrt{2}}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
      6. unpow2N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{\color{blue}{a1 \cdot a1}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
      7. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{\color{blue}{a1 \cdot a1}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
      8. lower-sqrt.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\color{blue}{\sqrt{2}}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
      9. lower-/.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \color{blue}{\frac{{a2}^{3}}{\sqrt{2}}}\right) \]
      10. cube-multN/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{\color{blue}{a2 \cdot \left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
      11. unpow2N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{{a2}^{2}}}{\sqrt{2}}\right) \]
      12. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{\color{blue}{a2 \cdot {a2}^{2}}}{\sqrt{2}}\right) \]
      13. unpow2N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{\left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
      14. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{\left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
      15. lower-sqrt.f6428.7

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \left(a2 \cdot a2\right)}{\color{blue}{\sqrt{2}}}\right) \]
    5. Simplified28.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \left(a2 \cdot a2\right)}{\sqrt{2}}\right)} \]
    6. Taylor expanded in a2 around -inf

      \[\leadsto \color{blue}{-1 \cdot \frac{{a2}^{2}}{\sqrt{2}}} \]
    7. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \color{blue}{\mathsf{neg}\left(\frac{{a2}^{2}}{\sqrt{2}}\right)} \]
      2. distribute-neg-frac2N/A

        \[\leadsto \color{blue}{\frac{{a2}^{2}}{\mathsf{neg}\left(\sqrt{2}\right)}} \]
      3. mul-1-negN/A

        \[\leadsto \frac{{a2}^{2}}{\color{blue}{-1 \cdot \sqrt{2}}} \]
      4. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{{a2}^{2}}{-1 \cdot \sqrt{2}}} \]
      5. unpow2N/A

        \[\leadsto \frac{\color{blue}{a2 \cdot a2}}{-1 \cdot \sqrt{2}} \]
      6. lower-*.f64N/A

        \[\leadsto \frac{\color{blue}{a2 \cdot a2}}{-1 \cdot \sqrt{2}} \]
      7. mul-1-negN/A

        \[\leadsto \frac{a2 \cdot a2}{\color{blue}{\mathsf{neg}\left(\sqrt{2}\right)}} \]
      8. lower-neg.f64N/A

        \[\leadsto \frac{a2 \cdot a2}{\color{blue}{\mathsf{neg}\left(\sqrt{2}\right)}} \]
      9. lower-sqrt.f6428.7

        \[\leadsto \frac{a2 \cdot a2}{-\color{blue}{\sqrt{2}}} \]
    8. Simplified28.7%

      \[\leadsto \color{blue}{\frac{a2 \cdot a2}{-\sqrt{2}}} \]

    if -1.00000000000000003e-306 < (+.f64 (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a1 a1)) (*.f64 (/.f64 (cos.f64 th) (sqrt.f64 #s(literal 2 binary64))) (*.f64 a2 a2)))

    1. Initial program 99.6%

      \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    2. Add Preprocessing
    3. Taylor expanded in th around 0

      \[\leadsto \color{blue}{\frac{{a1}^{3}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}}} \]
    4. Step-by-step derivation
      1. cube-multN/A

        \[\leadsto \frac{\color{blue}{a1 \cdot \left(a1 \cdot a1\right)}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}} \]
      2. unpow2N/A

        \[\leadsto \frac{a1 \cdot \color{blue}{{a1}^{2}}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}} \]
      3. associate-/l*N/A

        \[\leadsto \color{blue}{a1 \cdot \frac{{a1}^{2}}{\sqrt{2}}} + \frac{{a2}^{3}}{\sqrt{2}} \]
      4. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(a1, \frac{{a1}^{2}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right)} \]
      5. lower-/.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \color{blue}{\frac{{a1}^{2}}{\sqrt{2}}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
      6. unpow2N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{\color{blue}{a1 \cdot a1}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
      7. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{\color{blue}{a1 \cdot a1}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
      8. lower-sqrt.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\color{blue}{\sqrt{2}}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
      9. lower-/.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \color{blue}{\frac{{a2}^{3}}{\sqrt{2}}}\right) \]
      10. cube-multN/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{\color{blue}{a2 \cdot \left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
      11. unpow2N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{{a2}^{2}}}{\sqrt{2}}\right) \]
      12. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{\color{blue}{a2 \cdot {a2}^{2}}}{\sqrt{2}}\right) \]
      13. unpow2N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{\left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
      14. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{\left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
      15. lower-sqrt.f6432.6

        \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \left(a2 \cdot a2\right)}{\color{blue}{\sqrt{2}}}\right) \]
    5. Simplified32.6%

      \[\leadsto \color{blue}{\mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \left(a2 \cdot a2\right)}{\sqrt{2}}\right)} \]
    6. Taylor expanded in a1 around 0

      \[\leadsto \color{blue}{\frac{{a2}^{2}}{\sqrt{2}}} \]
    7. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{{a2}^{2}}{\sqrt{2}}} \]
      2. unpow2N/A

        \[\leadsto \frac{\color{blue}{a2 \cdot a2}}{\sqrt{2}} \]
      3. lower-*.f64N/A

        \[\leadsto \frac{\color{blue}{a2 \cdot a2}}{\sqrt{2}} \]
      4. lower-sqrt.f6452.0

        \[\leadsto \frac{a2 \cdot a2}{\color{blue}{\sqrt{2}}} \]
    8. Simplified52.0%

      \[\leadsto \color{blue}{\frac{a2 \cdot a2}{\sqrt{2}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification45.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(a1 \cdot a1\right) \cdot \frac{\cos th}{\sqrt{2}} + \left(a2 \cdot a2\right) \cdot \frac{\cos th}{\sqrt{2}} \leq -1 \cdot 10^{-306}:\\ \;\;\;\;-\frac{a2 \cdot a2}{\sqrt{2}}\\ \mathbf{else}:\\ \;\;\;\;\frac{a2 \cdot a2}{\sqrt{2}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 99.6% accurate, 1.8× speedup?

\[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \frac{\mathsf{fma}\left(a1\_m, a1\_m, a2 \cdot a2\right)}{\frac{\sqrt{2}}{\cos th}} \end{array} \]
a1_m = (fabs.f64 a1)
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
(FPCore (a1_m a2 th)
 :precision binary64
 (/ (fma a1_m a1_m (* a2 a2)) (/ (sqrt 2.0) (cos th))))
a1_m = fabs(a1);
assert(a1_m < a2 && a2 < th);
double code(double a1_m, double a2, double th) {
	return fma(a1_m, a1_m, (a2 * a2)) / (sqrt(2.0) / cos(th));
}
a1_m = abs(a1)
a1_m, a2, th = sort([a1_m, a2, th])
function code(a1_m, a2, th)
	return Float64(fma(a1_m, a1_m, Float64(a2 * a2)) / Float64(sqrt(2.0) / cos(th)))
end
a1_m = N[Abs[a1], $MachinePrecision]
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
code[a1$95$m_, a2_, th_] := N[(N[(a1$95$m * a1$95$m + N[(a2 * a2), $MachinePrecision]), $MachinePrecision] / N[(N[Sqrt[2.0], $MachinePrecision] / N[Cos[th], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
a1_m = \left|a1\right|
\\
[a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
\\
\frac{\mathsf{fma}\left(a1\_m, a1\_m, a2 \cdot a2\right)}{\frac{\sqrt{2}}{\cos th}}
\end{array}
Derivation
  1. Initial program 99.6%

    \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-cos.f64N/A

      \[\leadsto \frac{\color{blue}{\cos th}}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    2. lift-sqrt.f64N/A

      \[\leadsto \frac{\cos th}{\color{blue}{\sqrt{2}}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    3. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    4. lift-*.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \color{blue}{\left(a1 \cdot a1\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    5. lift-cos.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\color{blue}{\cos th}}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    6. lift-sqrt.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\color{blue}{\sqrt{2}}} \cdot \left(a2 \cdot a2\right) \]
    7. lift-/.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a2 \cdot a2\right) \]
    8. lift-*.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \color{blue}{\left(a2 \cdot a2\right)} \]
    9. distribute-lft-outN/A

      \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
    10. *-commutativeN/A

      \[\leadsto \color{blue}{\left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \frac{\cos th}{\sqrt{2}}} \]
    11. lift-/.f64N/A

      \[\leadsto \left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \color{blue}{\frac{\cos th}{\sqrt{2}}} \]
    12. clear-numN/A

      \[\leadsto \left(a1 \cdot a1 + a2 \cdot a2\right) \cdot \color{blue}{\frac{1}{\frac{\sqrt{2}}{\cos th}}} \]
    13. un-div-invN/A

      \[\leadsto \color{blue}{\frac{a1 \cdot a1 + a2 \cdot a2}{\frac{\sqrt{2}}{\cos th}}} \]
    14. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{a1 \cdot a1 + a2 \cdot a2}{\frac{\sqrt{2}}{\cos th}}} \]
    15. lift-*.f64N/A

      \[\leadsto \frac{\color{blue}{a1 \cdot a1} + a2 \cdot a2}{\frac{\sqrt{2}}{\cos th}} \]
    16. lower-fma.f64N/A

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}}{\frac{\sqrt{2}}{\cos th}} \]
    17. lower-/.f6499.6

      \[\leadsto \frac{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}{\color{blue}{\frac{\sqrt{2}}{\cos th}}} \]
  4. Applied egg-rr99.6%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}{\frac{\sqrt{2}}{\cos th}}} \]
  5. Add Preprocessing

Alternative 6: 99.6% accurate, 1.9× speedup?

\[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \cos th \cdot \frac{\mathsf{fma}\left(a1\_m, a1\_m, a2 \cdot a2\right)}{\sqrt{2}} \end{array} \]
a1_m = (fabs.f64 a1)
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
(FPCore (a1_m a2 th)
 :precision binary64
 (* (cos th) (/ (fma a1_m a1_m (* a2 a2)) (sqrt 2.0))))
a1_m = fabs(a1);
assert(a1_m < a2 && a2 < th);
double code(double a1_m, double a2, double th) {
	return cos(th) * (fma(a1_m, a1_m, (a2 * a2)) / sqrt(2.0));
}
a1_m = abs(a1)
a1_m, a2, th = sort([a1_m, a2, th])
function code(a1_m, a2, th)
	return Float64(cos(th) * Float64(fma(a1_m, a1_m, Float64(a2 * a2)) / sqrt(2.0)))
end
a1_m = N[Abs[a1], $MachinePrecision]
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
code[a1$95$m_, a2_, th_] := N[(N[Cos[th], $MachinePrecision] * N[(N[(a1$95$m * a1$95$m + N[(a2 * a2), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
a1_m = \left|a1\right|
\\
[a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
\\
\cos th \cdot \frac{\mathsf{fma}\left(a1\_m, a1\_m, a2 \cdot a2\right)}{\sqrt{2}}
\end{array}
Derivation
  1. Initial program 99.6%

    \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-cos.f64N/A

      \[\leadsto \frac{\color{blue}{\cos th}}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    2. lift-sqrt.f64N/A

      \[\leadsto \frac{\cos th}{\color{blue}{\sqrt{2}}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    3. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    4. lift-*.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \color{blue}{\left(a1 \cdot a1\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    5. lift-cos.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\color{blue}{\cos th}}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    6. lift-sqrt.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\color{blue}{\sqrt{2}}} \cdot \left(a2 \cdot a2\right) \]
    7. lift-/.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a2 \cdot a2\right) \]
    8. lift-*.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \color{blue}{\left(a2 \cdot a2\right)} \]
    9. distribute-lft-outN/A

      \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
    10. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
    11. div-invN/A

      \[\leadsto \color{blue}{\left(\cos th \cdot \frac{1}{\sqrt{2}}\right)} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
    12. associate-*l*N/A

      \[\leadsto \color{blue}{\cos th \cdot \left(\frac{1}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
    13. *-commutativeN/A

      \[\leadsto \color{blue}{\left(\frac{1}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \cdot \cos th} \]
    14. lower-*.f64N/A

      \[\leadsto \color{blue}{\left(\frac{1}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \cdot \cos th} \]
  4. Applied egg-rr99.6%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}{\sqrt{2}} \cdot \cos th} \]
  5. Final simplification99.6%

    \[\leadsto \cos th \cdot \frac{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}{\sqrt{2}} \]
  6. Add Preprocessing

Alternative 7: 77.5% accurate, 2.0× speedup?

\[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \cos th \cdot \frac{a2 \cdot a2}{\sqrt{2}} \end{array} \]
a1_m = (fabs.f64 a1)
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
(FPCore (a1_m a2 th) :precision binary64 (* (cos th) (/ (* a2 a2) (sqrt 2.0))))
a1_m = fabs(a1);
assert(a1_m < a2 && a2 < th);
double code(double a1_m, double a2, double th) {
	return cos(th) * ((a2 * a2) / sqrt(2.0));
}
a1_m = abs(a1)
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
real(8) function code(a1_m, a2, th)
    real(8), intent (in) :: a1_m
    real(8), intent (in) :: a2
    real(8), intent (in) :: th
    code = cos(th) * ((a2 * a2) / sqrt(2.0d0))
end function
a1_m = Math.abs(a1);
assert a1_m < a2 && a2 < th;
public static double code(double a1_m, double a2, double th) {
	return Math.cos(th) * ((a2 * a2) / Math.sqrt(2.0));
}
a1_m = math.fabs(a1)
[a1_m, a2, th] = sort([a1_m, a2, th])
def code(a1_m, a2, th):
	return math.cos(th) * ((a2 * a2) / math.sqrt(2.0))
a1_m = abs(a1)
a1_m, a2, th = sort([a1_m, a2, th])
function code(a1_m, a2, th)
	return Float64(cos(th) * Float64(Float64(a2 * a2) / sqrt(2.0)))
end
a1_m = abs(a1);
a1_m, a2, th = num2cell(sort([a1_m, a2, th])){:}
function tmp = code(a1_m, a2, th)
	tmp = cos(th) * ((a2 * a2) / sqrt(2.0));
end
a1_m = N[Abs[a1], $MachinePrecision]
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
code[a1$95$m_, a2_, th_] := N[(N[Cos[th], $MachinePrecision] * N[(N[(a2 * a2), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
a1_m = \left|a1\right|
\\
[a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
\\
\cos th \cdot \frac{a2 \cdot a2}{\sqrt{2}}
\end{array}
Derivation
  1. Initial program 99.6%

    \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-cos.f64N/A

      \[\leadsto \frac{\color{blue}{\cos th}}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    2. lift-sqrt.f64N/A

      \[\leadsto \frac{\cos th}{\color{blue}{\sqrt{2}}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    3. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    4. lift-*.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \color{blue}{\left(a1 \cdot a1\right)} + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    5. lift-cos.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\color{blue}{\cos th}}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    6. lift-sqrt.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\color{blue}{\sqrt{2}}} \cdot \left(a2 \cdot a2\right) \]
    7. lift-/.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a2 \cdot a2\right) \]
    8. lift-*.f64N/A

      \[\leadsto \frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \color{blue}{\left(a2 \cdot a2\right)} \]
    9. distribute-lft-outN/A

      \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)} \]
    10. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{\cos th}{\sqrt{2}}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
    11. div-invN/A

      \[\leadsto \color{blue}{\left(\cos th \cdot \frac{1}{\sqrt{2}}\right)} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right) \]
    12. associate-*l*N/A

      \[\leadsto \color{blue}{\cos th \cdot \left(\frac{1}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right)} \]
    13. *-commutativeN/A

      \[\leadsto \color{blue}{\left(\frac{1}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \cdot \cos th} \]
    14. lower-*.f64N/A

      \[\leadsto \color{blue}{\left(\frac{1}{\sqrt{2}} \cdot \left(a1 \cdot a1 + a2 \cdot a2\right)\right) \cdot \cos th} \]
  4. Applied egg-rr99.6%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(a1, a1, a2 \cdot a2\right)}{\sqrt{2}} \cdot \cos th} \]
  5. Taylor expanded in a1 around 0

    \[\leadsto \frac{\color{blue}{{a2}^{2}}}{\sqrt{2}} \cdot \cos th \]
  6. Step-by-step derivation
    1. unpow2N/A

      \[\leadsto \frac{\color{blue}{a2 \cdot a2}}{\sqrt{2}} \cdot \cos th \]
    2. lower-*.f6456.9

      \[\leadsto \frac{\color{blue}{a2 \cdot a2}}{\sqrt{2}} \cdot \cos th \]
  7. Simplified56.9%

    \[\leadsto \frac{\color{blue}{a2 \cdot a2}}{\sqrt{2}} \cdot \cos th \]
  8. Final simplification56.9%

    \[\leadsto \cos th \cdot \frac{a2 \cdot a2}{\sqrt{2}} \]
  9. Add Preprocessing

Alternative 8: 51.8% accurate, 9.9× speedup?

\[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \frac{a2 \cdot a2}{\sqrt{2}} \end{array} \]
a1_m = (fabs.f64 a1)
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
(FPCore (a1_m a2 th) :precision binary64 (/ (* a2 a2) (sqrt 2.0)))
a1_m = fabs(a1);
assert(a1_m < a2 && a2 < th);
double code(double a1_m, double a2, double th) {
	return (a2 * a2) / sqrt(2.0);
}
a1_m = abs(a1)
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
real(8) function code(a1_m, a2, th)
    real(8), intent (in) :: a1_m
    real(8), intent (in) :: a2
    real(8), intent (in) :: th
    code = (a2 * a2) / sqrt(2.0d0)
end function
a1_m = Math.abs(a1);
assert a1_m < a2 && a2 < th;
public static double code(double a1_m, double a2, double th) {
	return (a2 * a2) / Math.sqrt(2.0);
}
a1_m = math.fabs(a1)
[a1_m, a2, th] = sort([a1_m, a2, th])
def code(a1_m, a2, th):
	return (a2 * a2) / math.sqrt(2.0)
a1_m = abs(a1)
a1_m, a2, th = sort([a1_m, a2, th])
function code(a1_m, a2, th)
	return Float64(Float64(a2 * a2) / sqrt(2.0))
end
a1_m = abs(a1);
a1_m, a2, th = num2cell(sort([a1_m, a2, th])){:}
function tmp = code(a1_m, a2, th)
	tmp = (a2 * a2) / sqrt(2.0);
end
a1_m = N[Abs[a1], $MachinePrecision]
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
code[a1$95$m_, a2_, th_] := N[(N[(a2 * a2), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
a1_m = \left|a1\right|
\\
[a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
\\
\frac{a2 \cdot a2}{\sqrt{2}}
\end{array}
Derivation
  1. Initial program 99.6%

    \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
  2. Add Preprocessing
  3. Taylor expanded in th around 0

    \[\leadsto \color{blue}{\frac{{a1}^{3}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}}} \]
  4. Step-by-step derivation
    1. cube-multN/A

      \[\leadsto \frac{\color{blue}{a1 \cdot \left(a1 \cdot a1\right)}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}} \]
    2. unpow2N/A

      \[\leadsto \frac{a1 \cdot \color{blue}{{a1}^{2}}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}} \]
    3. associate-/l*N/A

      \[\leadsto \color{blue}{a1 \cdot \frac{{a1}^{2}}{\sqrt{2}}} + \frac{{a2}^{3}}{\sqrt{2}} \]
    4. lower-fma.f64N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(a1, \frac{{a1}^{2}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right)} \]
    5. lower-/.f64N/A

      \[\leadsto \mathsf{fma}\left(a1, \color{blue}{\frac{{a1}^{2}}{\sqrt{2}}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
    6. unpow2N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{\color{blue}{a1 \cdot a1}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
    7. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{\color{blue}{a1 \cdot a1}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
    8. lower-sqrt.f64N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\color{blue}{\sqrt{2}}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
    9. lower-/.f64N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \color{blue}{\frac{{a2}^{3}}{\sqrt{2}}}\right) \]
    10. cube-multN/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{\color{blue}{a2 \cdot \left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
    11. unpow2N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{{a2}^{2}}}{\sqrt{2}}\right) \]
    12. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{\color{blue}{a2 \cdot {a2}^{2}}}{\sqrt{2}}\right) \]
    13. unpow2N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{\left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
    14. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{\left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
    15. lower-sqrt.f6431.4

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \left(a2 \cdot a2\right)}{\color{blue}{\sqrt{2}}}\right) \]
  5. Simplified31.4%

    \[\leadsto \color{blue}{\mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \left(a2 \cdot a2\right)}{\sqrt{2}}\right)} \]
  6. Taylor expanded in a1 around 0

    \[\leadsto \color{blue}{\frac{{a2}^{2}}{\sqrt{2}}} \]
  7. Step-by-step derivation
    1. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{{a2}^{2}}{\sqrt{2}}} \]
    2. unpow2N/A

      \[\leadsto \frac{\color{blue}{a2 \cdot a2}}{\sqrt{2}} \]
    3. lower-*.f64N/A

      \[\leadsto \frac{\color{blue}{a2 \cdot a2}}{\sqrt{2}} \]
    4. lower-sqrt.f6436.9

      \[\leadsto \frac{a2 \cdot a2}{\color{blue}{\sqrt{2}}} \]
  8. Simplified36.9%

    \[\leadsto \color{blue}{\frac{a2 \cdot a2}{\sqrt{2}}} \]
  9. Add Preprocessing

Alternative 9: 51.8% accurate, 9.9× speedup?

\[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ a2 \cdot \frac{a2}{\sqrt{2}} \end{array} \]
a1_m = (fabs.f64 a1)
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
(FPCore (a1_m a2 th) :precision binary64 (* a2 (/ a2 (sqrt 2.0))))
a1_m = fabs(a1);
assert(a1_m < a2 && a2 < th);
double code(double a1_m, double a2, double th) {
	return a2 * (a2 / sqrt(2.0));
}
a1_m = abs(a1)
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
real(8) function code(a1_m, a2, th)
    real(8), intent (in) :: a1_m
    real(8), intent (in) :: a2
    real(8), intent (in) :: th
    code = a2 * (a2 / sqrt(2.0d0))
end function
a1_m = Math.abs(a1);
assert a1_m < a2 && a2 < th;
public static double code(double a1_m, double a2, double th) {
	return a2 * (a2 / Math.sqrt(2.0));
}
a1_m = math.fabs(a1)
[a1_m, a2, th] = sort([a1_m, a2, th])
def code(a1_m, a2, th):
	return a2 * (a2 / math.sqrt(2.0))
a1_m = abs(a1)
a1_m, a2, th = sort([a1_m, a2, th])
function code(a1_m, a2, th)
	return Float64(a2 * Float64(a2 / sqrt(2.0)))
end
a1_m = abs(a1);
a1_m, a2, th = num2cell(sort([a1_m, a2, th])){:}
function tmp = code(a1_m, a2, th)
	tmp = a2 * (a2 / sqrt(2.0));
end
a1_m = N[Abs[a1], $MachinePrecision]
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
code[a1$95$m_, a2_, th_] := N[(a2 * N[(a2 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
a1_m = \left|a1\right|
\\
[a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
\\
a2 \cdot \frac{a2}{\sqrt{2}}
\end{array}
Derivation
  1. Initial program 99.6%

    \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
  2. Add Preprocessing
  3. Taylor expanded in th around 0

    \[\leadsto \color{blue}{\frac{{a1}^{3}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}}} \]
  4. Step-by-step derivation
    1. cube-multN/A

      \[\leadsto \frac{\color{blue}{a1 \cdot \left(a1 \cdot a1\right)}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}} \]
    2. unpow2N/A

      \[\leadsto \frac{a1 \cdot \color{blue}{{a1}^{2}}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}} \]
    3. associate-/l*N/A

      \[\leadsto \color{blue}{a1 \cdot \frac{{a1}^{2}}{\sqrt{2}}} + \frac{{a2}^{3}}{\sqrt{2}} \]
    4. lower-fma.f64N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(a1, \frac{{a1}^{2}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right)} \]
    5. lower-/.f64N/A

      \[\leadsto \mathsf{fma}\left(a1, \color{blue}{\frac{{a1}^{2}}{\sqrt{2}}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
    6. unpow2N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{\color{blue}{a1 \cdot a1}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
    7. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{\color{blue}{a1 \cdot a1}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
    8. lower-sqrt.f64N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\color{blue}{\sqrt{2}}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
    9. lower-/.f64N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \color{blue}{\frac{{a2}^{3}}{\sqrt{2}}}\right) \]
    10. cube-multN/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{\color{blue}{a2 \cdot \left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
    11. unpow2N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{{a2}^{2}}}{\sqrt{2}}\right) \]
    12. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{\color{blue}{a2 \cdot {a2}^{2}}}{\sqrt{2}}\right) \]
    13. unpow2N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{\left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
    14. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{\left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
    15. lower-sqrt.f6431.4

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \left(a2 \cdot a2\right)}{\color{blue}{\sqrt{2}}}\right) \]
  5. Simplified31.4%

    \[\leadsto \color{blue}{\mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \left(a2 \cdot a2\right)}{\sqrt{2}}\right)} \]
  6. Taylor expanded in a1 around -inf

    \[\leadsto \color{blue}{{a1}^{2} \cdot \left(\frac{{a2}^{2}}{{a1}^{2} \cdot \sqrt{2}} - \frac{1}{\sqrt{2}}\right)} \]
  7. Step-by-step derivation
    1. lower-*.f64N/A

      \[\leadsto \color{blue}{{a1}^{2} \cdot \left(\frac{{a2}^{2}}{{a1}^{2} \cdot \sqrt{2}} - \frac{1}{\sqrt{2}}\right)} \]
    2. unpow2N/A

      \[\leadsto \color{blue}{\left(a1 \cdot a1\right)} \cdot \left(\frac{{a2}^{2}}{{a1}^{2} \cdot \sqrt{2}} - \frac{1}{\sqrt{2}}\right) \]
    3. lower-*.f64N/A

      \[\leadsto \color{blue}{\left(a1 \cdot a1\right)} \cdot \left(\frac{{a2}^{2}}{{a1}^{2} \cdot \sqrt{2}} - \frac{1}{\sqrt{2}}\right) \]
    4. sub-negN/A

      \[\leadsto \left(a1 \cdot a1\right) \cdot \color{blue}{\left(\frac{{a2}^{2}}{{a1}^{2} \cdot \sqrt{2}} + \left(\mathsf{neg}\left(\frac{1}{\sqrt{2}}\right)\right)\right)} \]
    5. unpow2N/A

      \[\leadsto \left(a1 \cdot a1\right) \cdot \left(\frac{\color{blue}{a2 \cdot a2}}{{a1}^{2} \cdot \sqrt{2}} + \left(\mathsf{neg}\left(\frac{1}{\sqrt{2}}\right)\right)\right) \]
    6. associate-/l*N/A

      \[\leadsto \left(a1 \cdot a1\right) \cdot \left(\color{blue}{a2 \cdot \frac{a2}{{a1}^{2} \cdot \sqrt{2}}} + \left(\mathsf{neg}\left(\frac{1}{\sqrt{2}}\right)\right)\right) \]
    7. distribute-neg-fracN/A

      \[\leadsto \left(a1 \cdot a1\right) \cdot \left(a2 \cdot \frac{a2}{{a1}^{2} \cdot \sqrt{2}} + \color{blue}{\frac{\mathsf{neg}\left(1\right)}{\sqrt{2}}}\right) \]
    8. metadata-evalN/A

      \[\leadsto \left(a1 \cdot a1\right) \cdot \left(a2 \cdot \frac{a2}{{a1}^{2} \cdot \sqrt{2}} + \frac{\color{blue}{-1}}{\sqrt{2}}\right) \]
    9. lower-fma.f64N/A

      \[\leadsto \left(a1 \cdot a1\right) \cdot \color{blue}{\mathsf{fma}\left(a2, \frac{a2}{{a1}^{2} \cdot \sqrt{2}}, \frac{-1}{\sqrt{2}}\right)} \]
    10. lower-/.f64N/A

      \[\leadsto \left(a1 \cdot a1\right) \cdot \mathsf{fma}\left(a2, \color{blue}{\frac{a2}{{a1}^{2} \cdot \sqrt{2}}}, \frac{-1}{\sqrt{2}}\right) \]
    11. *-commutativeN/A

      \[\leadsto \left(a1 \cdot a1\right) \cdot \mathsf{fma}\left(a2, \frac{a2}{\color{blue}{\sqrt{2} \cdot {a1}^{2}}}, \frac{-1}{\sqrt{2}}\right) \]
    12. lower-*.f64N/A

      \[\leadsto \left(a1 \cdot a1\right) \cdot \mathsf{fma}\left(a2, \frac{a2}{\color{blue}{\sqrt{2} \cdot {a1}^{2}}}, \frac{-1}{\sqrt{2}}\right) \]
    13. lower-sqrt.f64N/A

      \[\leadsto \left(a1 \cdot a1\right) \cdot \mathsf{fma}\left(a2, \frac{a2}{\color{blue}{\sqrt{2}} \cdot {a1}^{2}}, \frac{-1}{\sqrt{2}}\right) \]
    14. unpow2N/A

      \[\leadsto \left(a1 \cdot a1\right) \cdot \mathsf{fma}\left(a2, \frac{a2}{\sqrt{2} \cdot \color{blue}{\left(a1 \cdot a1\right)}}, \frac{-1}{\sqrt{2}}\right) \]
    15. lower-*.f64N/A

      \[\leadsto \left(a1 \cdot a1\right) \cdot \mathsf{fma}\left(a2, \frac{a2}{\sqrt{2} \cdot \color{blue}{\left(a1 \cdot a1\right)}}, \frac{-1}{\sqrt{2}}\right) \]
    16. lower-/.f64N/A

      \[\leadsto \left(a1 \cdot a1\right) \cdot \mathsf{fma}\left(a2, \frac{a2}{\sqrt{2} \cdot \left(a1 \cdot a1\right)}, \color{blue}{\frac{-1}{\sqrt{2}}}\right) \]
    17. lower-sqrt.f6423.5

      \[\leadsto \left(a1 \cdot a1\right) \cdot \mathsf{fma}\left(a2, \frac{a2}{\sqrt{2} \cdot \left(a1 \cdot a1\right)}, \frac{-1}{\color{blue}{\sqrt{2}}}\right) \]
  8. Simplified23.5%

    \[\leadsto \color{blue}{\left(a1 \cdot a1\right) \cdot \mathsf{fma}\left(a2, \frac{a2}{\sqrt{2} \cdot \left(a1 \cdot a1\right)}, \frac{-1}{\sqrt{2}}\right)} \]
  9. Taylor expanded in a1 around 0

    \[\leadsto \color{blue}{\frac{{a2}^{2}}{\sqrt{2}}} \]
  10. Step-by-step derivation
    1. unpow2N/A

      \[\leadsto \frac{\color{blue}{a2 \cdot a2}}{\sqrt{2}} \]
    2. associate-/l*N/A

      \[\leadsto \color{blue}{a2 \cdot \frac{a2}{\sqrt{2}}} \]
    3. lower-*.f64N/A

      \[\leadsto \color{blue}{a2 \cdot \frac{a2}{\sqrt{2}}} \]
    4. lower-/.f64N/A

      \[\leadsto a2 \cdot \color{blue}{\frac{a2}{\sqrt{2}}} \]
    5. lower-sqrt.f6437.0

      \[\leadsto a2 \cdot \frac{a2}{\color{blue}{\sqrt{2}}} \]
  11. Simplified37.0%

    \[\leadsto \color{blue}{a2 \cdot \frac{a2}{\sqrt{2}}} \]
  12. Add Preprocessing

Alternative 10: 3.2% accurate, 12.1× speedup?

\[\begin{array}{l} a1_m = \left|a1\right| \\ [a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\ \\ \frac{a1\_m}{\sqrt{2}} \end{array} \]
a1_m = (fabs.f64 a1)
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
(FPCore (a1_m a2 th) :precision binary64 (/ a1_m (sqrt 2.0)))
a1_m = fabs(a1);
assert(a1_m < a2 && a2 < th);
double code(double a1_m, double a2, double th) {
	return a1_m / sqrt(2.0);
}
a1_m = abs(a1)
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
real(8) function code(a1_m, a2, th)
    real(8), intent (in) :: a1_m
    real(8), intent (in) :: a2
    real(8), intent (in) :: th
    code = a1_m / sqrt(2.0d0)
end function
a1_m = Math.abs(a1);
assert a1_m < a2 && a2 < th;
public static double code(double a1_m, double a2, double th) {
	return a1_m / Math.sqrt(2.0);
}
a1_m = math.fabs(a1)
[a1_m, a2, th] = sort([a1_m, a2, th])
def code(a1_m, a2, th):
	return a1_m / math.sqrt(2.0)
a1_m = abs(a1)
a1_m, a2, th = sort([a1_m, a2, th])
function code(a1_m, a2, th)
	return Float64(a1_m / sqrt(2.0))
end
a1_m = abs(a1);
a1_m, a2, th = num2cell(sort([a1_m, a2, th])){:}
function tmp = code(a1_m, a2, th)
	tmp = a1_m / sqrt(2.0);
end
a1_m = N[Abs[a1], $MachinePrecision]
NOTE: a1_m, a2, and th should be sorted in increasing order before calling this function.
code[a1$95$m_, a2_, th_] := N[(a1$95$m / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
a1_m = \left|a1\right|
\\
[a1_m, a2, th] = \mathsf{sort}([a1_m, a2, th])\\
\\
\frac{a1\_m}{\sqrt{2}}
\end{array}
Derivation
  1. Initial program 99.6%

    \[\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
  2. Add Preprocessing
  3. Taylor expanded in th around 0

    \[\leadsto \color{blue}{\frac{{a1}^{3}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}}} \]
  4. Step-by-step derivation
    1. cube-multN/A

      \[\leadsto \frac{\color{blue}{a1 \cdot \left(a1 \cdot a1\right)}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}} \]
    2. unpow2N/A

      \[\leadsto \frac{a1 \cdot \color{blue}{{a1}^{2}}}{\sqrt{2}} + \frac{{a2}^{3}}{\sqrt{2}} \]
    3. associate-/l*N/A

      \[\leadsto \color{blue}{a1 \cdot \frac{{a1}^{2}}{\sqrt{2}}} + \frac{{a2}^{3}}{\sqrt{2}} \]
    4. lower-fma.f64N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(a1, \frac{{a1}^{2}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right)} \]
    5. lower-/.f64N/A

      \[\leadsto \mathsf{fma}\left(a1, \color{blue}{\frac{{a1}^{2}}{\sqrt{2}}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
    6. unpow2N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{\color{blue}{a1 \cdot a1}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
    7. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{\color{blue}{a1 \cdot a1}}{\sqrt{2}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
    8. lower-sqrt.f64N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\color{blue}{\sqrt{2}}}, \frac{{a2}^{3}}{\sqrt{2}}\right) \]
    9. lower-/.f64N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \color{blue}{\frac{{a2}^{3}}{\sqrt{2}}}\right) \]
    10. cube-multN/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{\color{blue}{a2 \cdot \left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
    11. unpow2N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{{a2}^{2}}}{\sqrt{2}}\right) \]
    12. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{\color{blue}{a2 \cdot {a2}^{2}}}{\sqrt{2}}\right) \]
    13. unpow2N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{\left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
    14. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \color{blue}{\left(a2 \cdot a2\right)}}{\sqrt{2}}\right) \]
    15. lower-sqrt.f6431.4

      \[\leadsto \mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \left(a2 \cdot a2\right)}{\color{blue}{\sqrt{2}}}\right) \]
  5. Simplified31.4%

    \[\leadsto \color{blue}{\mathsf{fma}\left(a1, \frac{a1 \cdot a1}{\sqrt{2}}, \frac{a2 \cdot \left(a2 \cdot a2\right)}{\sqrt{2}}\right)} \]
  6. Taylor expanded in a2 around 0

    \[\leadsto \color{blue}{\frac{{a1}^{2}}{\sqrt{2}}} \]
  7. Step-by-step derivation
    1. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{{a1}^{2}}{\sqrt{2}}} \]
    2. unpow2N/A

      \[\leadsto \frac{\color{blue}{a1 \cdot a1}}{\sqrt{2}} \]
    3. lower-*.f64N/A

      \[\leadsto \frac{\color{blue}{a1 \cdot a1}}{\sqrt{2}} \]
    4. lower-sqrt.f6436.6

      \[\leadsto \frac{a1 \cdot a1}{\color{blue}{\sqrt{2}}} \]
  8. Simplified36.6%

    \[\leadsto \color{blue}{\frac{a1 \cdot a1}{\sqrt{2}}} \]
  9. Taylor expanded in a1 around 0

    \[\leadsto \color{blue}{\frac{a1}{\sqrt{2}}} \]
  10. Step-by-step derivation
    1. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{a1}{\sqrt{2}}} \]
    2. lower-sqrt.f643.6

      \[\leadsto \frac{a1}{\color{blue}{\sqrt{2}}} \]
  11. Simplified3.6%

    \[\leadsto \color{blue}{\frac{a1}{\sqrt{2}}} \]
  12. Add Preprocessing

Reproduce

?
herbie shell --seed 2024214 
(FPCore (a1 a2 th)
  :name "Migdal et al, Equation (64)"
  :precision binary64
  (+ (* (/ (cos th) (sqrt 2.0)) (* a1 a1)) (* (/ (cos th) (sqrt 2.0)) (* a2 a2))))