Migdal et al, Equation (64)

Percentage Accurate: 99.5% → 99.6%
Time: 6.6s
Alternatives: 11
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 11 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?

\[\begin{array}{l} \\ \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\frac{\sqrt{2}}{\cos th}} \end{array} \]
(FPCore (a1 a2 th)
 :precision binary64
 (/ (fma a2 a2 (* a1 a1)) (/ (sqrt 2.0) (cos th))))
double code(double a1, double a2, double th) {
	return fma(a2, a2, (a1 * a1)) / (sqrt(2.0) / cos(th));
}
function code(a1, a2, th)
	return Float64(fma(a2, a2, Float64(a1 * a1)) / Float64(sqrt(2.0) / cos(th)))
end
code[a1_, a2_, th_] := N[(N[(a2 * a2 + N[(a1 * a1), $MachinePrecision]), $MachinePrecision] / N[(N[Sqrt[2.0], $MachinePrecision] / N[Cos[th], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\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-+.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\frac{\sqrt{2}}{\cos th}}} \]
  4. Applied rewrites99.7%

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

Alternative 2: 75.1% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{a2}{\sqrt{2}} \cdot a2\\ t_2 := \frac{\cos th}{\sqrt{2}}\\ \mathbf{if}\;t\_2 \cdot \left(a1 \cdot a1\right) + t\_2 \cdot \left(a2 \cdot a2\right) \leq -1 \cdot 10^{-192}:\\ \;\;\;\;t\_1 \cdot \mathsf{fma}\left(th \cdot th, -0.5, 1\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{a1}{\sqrt{2}}, a1, t\_1\right)\\ \end{array} \end{array} \]
(FPCore (a1 a2 th)
 :precision binary64
 (let* ((t_1 (* (/ a2 (sqrt 2.0)) a2)) (t_2 (/ (cos th) (sqrt 2.0))))
   (if (<= (+ (* t_2 (* a1 a1)) (* t_2 (* a2 a2))) -1e-192)
     (* t_1 (fma (* th th) -0.5 1.0))
     (fma (/ a1 (sqrt 2.0)) a1 t_1))))
double code(double a1, double a2, double th) {
	double t_1 = (a2 / sqrt(2.0)) * a2;
	double t_2 = cos(th) / sqrt(2.0);
	double tmp;
	if (((t_2 * (a1 * a1)) + (t_2 * (a2 * a2))) <= -1e-192) {
		tmp = t_1 * fma((th * th), -0.5, 1.0);
	} else {
		tmp = fma((a1 / sqrt(2.0)), a1, t_1);
	}
	return tmp;
}
function code(a1, a2, th)
	t_1 = Float64(Float64(a2 / sqrt(2.0)) * a2)
	t_2 = Float64(cos(th) / sqrt(2.0))
	tmp = 0.0
	if (Float64(Float64(t_2 * Float64(a1 * a1)) + Float64(t_2 * Float64(a2 * a2))) <= -1e-192)
		tmp = Float64(t_1 * fma(Float64(th * th), -0.5, 1.0));
	else
		tmp = fma(Float64(a1 / sqrt(2.0)), a1, t_1);
	end
	return tmp
end
code[a1_, a2_, th_] := Block[{t$95$1 = N[(N[(a2 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * a2), $MachinePrecision]}, Block[{t$95$2 = N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(t$95$2 * N[(a1 * a1), $MachinePrecision]), $MachinePrecision] + N[(t$95$2 * N[(a2 * a2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1e-192], N[(t$95$1 * N[(N[(th * th), $MachinePrecision] * -0.5 + 1.0), $MachinePrecision]), $MachinePrecision], N[(N[(a1 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * a1 + t$95$1), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{a2}{\sqrt{2}} \cdot a2\\
t_2 := \frac{\cos th}{\sqrt{2}}\\
\mathbf{if}\;t\_2 \cdot \left(a1 \cdot a1\right) + t\_2 \cdot \left(a2 \cdot a2\right) \leq -1 \cdot 10^{-192}:\\
\;\;\;\;t\_1 \cdot \mathsf{fma}\left(th \cdot th, -0.5, 1\right)\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\frac{a1}{\sqrt{2}}, a1, t\_1\right)\\


\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))) < -1.0000000000000001e-192

    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 a1 around 0

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

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

        \[\leadsto \frac{\cos th \cdot \color{blue}{\left(a2 \cdot a2\right)}}{\sqrt{2}} \]
      3. associate-*r*N/A

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

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

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

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

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

        \[\leadsto \left(\cos th \cdot a2\right) \cdot \color{blue}{\frac{a2}{\sqrt{2}}} \]
      9. lower-sqrt.f6464.1

        \[\leadsto \left(\cos th \cdot a2\right) \cdot \frac{a2}{\color{blue}{\sqrt{2}}} \]
    5. Applied rewrites64.1%

      \[\leadsto \color{blue}{\left(\cos th \cdot a2\right) \cdot \frac{a2}{\sqrt{2}}} \]
    6. Step-by-step derivation
      1. Applied rewrites64.2%

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

        \[\leadsto \frac{-1}{2} \cdot \frac{{a2}^{2} \cdot {th}^{2}}{\sqrt{2}} + \color{blue}{\frac{{a2}^{2}}{\sqrt{2}}} \]
      3. Step-by-step derivation
        1. Applied rewrites31.6%

          \[\leadsto \mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot \color{blue}{\left(\frac{a2}{\sqrt{2}} \cdot a2\right)} \]

        if -1.0000000000000001e-192 < (+.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 99.7%

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

          \[\leadsto \color{blue}{\frac{{a1}^{2}}{\sqrt{2}} + \frac{{a2}^{2}}{\sqrt{2}}} \]
        4. Step-by-step derivation
          1. unpow2N/A

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

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

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

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

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

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

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

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

            \[\leadsto \mathsf{fma}\left(\frac{a1}{\sqrt{2}}, a1, \color{blue}{\frac{a2}{\sqrt{2}}} \cdot a2\right) \]
          10. lower-sqrt.f6485.4

            \[\leadsto \mathsf{fma}\left(\frac{a1}{\sqrt{2}}, a1, \frac{a2}{\color{blue}{\sqrt{2}}} \cdot a2\right) \]
        5. Applied rewrites85.4%

          \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{a1}{\sqrt{2}}, a1, \frac{a2}{\sqrt{2}} \cdot a2\right)} \]
      4. Recombined 2 regimes into one program.
      5. Final simplification72.8%

        \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \leq -1 \cdot 10^{-192}:\\ \;\;\;\;\left(\frac{a2}{\sqrt{2}} \cdot a2\right) \cdot \mathsf{fma}\left(th \cdot th, -0.5, 1\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{a1}{\sqrt{2}}, a1, \frac{a2}{\sqrt{2}} \cdot a2\right)\\ \end{array} \]
      6. Add Preprocessing

      Alternative 3: 75.1% accurate, 0.8× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{\cos th}{\sqrt{2}}\\ \mathbf{if}\;t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right) \leq -1 \cdot 10^{-192}:\\ \;\;\;\;\left(\frac{a2}{\sqrt{2}} \cdot a2\right) \cdot \mathsf{fma}\left(th \cdot th, -0.5, 1\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}}\\ \end{array} \end{array} \]
      (FPCore (a1 a2 th)
       :precision binary64
       (let* ((t_1 (/ (cos th) (sqrt 2.0))))
         (if (<= (+ (* t_1 (* a1 a1)) (* t_1 (* a2 a2))) -1e-192)
           (* (* (/ a2 (sqrt 2.0)) a2) (fma (* th th) -0.5 1.0))
           (/ (fma a2 a2 (* a1 a1)) (sqrt 2.0)))))
      double code(double a1, double a2, double th) {
      	double t_1 = cos(th) / sqrt(2.0);
      	double tmp;
      	if (((t_1 * (a1 * a1)) + (t_1 * (a2 * a2))) <= -1e-192) {
      		tmp = ((a2 / sqrt(2.0)) * a2) * fma((th * th), -0.5, 1.0);
      	} else {
      		tmp = fma(a2, a2, (a1 * a1)) / sqrt(2.0);
      	}
      	return tmp;
      }
      
      function code(a1, a2, th)
      	t_1 = Float64(cos(th) / sqrt(2.0))
      	tmp = 0.0
      	if (Float64(Float64(t_1 * Float64(a1 * a1)) + Float64(t_1 * Float64(a2 * a2))) <= -1e-192)
      		tmp = Float64(Float64(Float64(a2 / sqrt(2.0)) * a2) * fma(Float64(th * th), -0.5, 1.0));
      	else
      		tmp = Float64(fma(a2, a2, Float64(a1 * a1)) / sqrt(2.0));
      	end
      	return tmp
      end
      
      code[a1_, a2_, th_] := Block[{t$95$1 = N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(t$95$1 * N[(a1 * a1), $MachinePrecision]), $MachinePrecision] + N[(t$95$1 * N[(a2 * a2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1e-192], N[(N[(N[(a2 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * a2), $MachinePrecision] * N[(N[(th * th), $MachinePrecision] * -0.5 + 1.0), $MachinePrecision]), $MachinePrecision], N[(N[(a2 * a2 + N[(a1 * a1), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      t_1 := \frac{\cos th}{\sqrt{2}}\\
      \mathbf{if}\;t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right) \leq -1 \cdot 10^{-192}:\\
      \;\;\;\;\left(\frac{a2}{\sqrt{2}} \cdot a2\right) \cdot \mathsf{fma}\left(th \cdot th, -0.5, 1\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\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))) < -1.0000000000000001e-192

        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 a1 around 0

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

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

            \[\leadsto \frac{\cos th \cdot \color{blue}{\left(a2 \cdot a2\right)}}{\sqrt{2}} \]
          3. associate-*r*N/A

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

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

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

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

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

            \[\leadsto \left(\cos th \cdot a2\right) \cdot \color{blue}{\frac{a2}{\sqrt{2}}} \]
          9. lower-sqrt.f6464.1

            \[\leadsto \left(\cos th \cdot a2\right) \cdot \frac{a2}{\color{blue}{\sqrt{2}}} \]
        5. Applied rewrites64.1%

          \[\leadsto \color{blue}{\left(\cos th \cdot a2\right) \cdot \frac{a2}{\sqrt{2}}} \]
        6. Step-by-step derivation
          1. Applied rewrites64.2%

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

            \[\leadsto \frac{-1}{2} \cdot \frac{{a2}^{2} \cdot {th}^{2}}{\sqrt{2}} + \color{blue}{\frac{{a2}^{2}}{\sqrt{2}}} \]
          3. Step-by-step derivation
            1. Applied rewrites31.6%

              \[\leadsto \mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot \color{blue}{\left(\frac{a2}{\sqrt{2}} \cdot a2\right)} \]

            if -1.0000000000000001e-192 < (+.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 99.7%

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

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

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

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

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

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

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

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

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

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

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

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

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

                \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\frac{\sqrt{2}}{\cos th}}} \]
            4. Applied rewrites99.7%

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

              \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
            6. Step-by-step derivation
              1. lower-sqrt.f6485.4

                \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
            7. Applied rewrites85.4%

              \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
          4. Recombined 2 regimes into one program.
          5. Final simplification72.8%

            \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \leq -1 \cdot 10^{-192}:\\ \;\;\;\;\left(\frac{a2}{\sqrt{2}} \cdot a2\right) \cdot \mathsf{fma}\left(th \cdot th, -0.5, 1\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}}\\ \end{array} \]
          6. Add Preprocessing

          Alternative 4: 99.6% accurate, 1.9× speedup?

          \[\begin{array}{l} \\ \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}} \cdot \cos th \end{array} \]
          (FPCore (a1 a2 th)
           :precision binary64
           (* (/ (fma a2 a2 (* a1 a1)) (sqrt 2.0)) (cos th)))
          double code(double a1, double a2, double th) {
          	return (fma(a2, a2, (a1 * a1)) / sqrt(2.0)) * cos(th);
          }
          
          function code(a1, a2, th)
          	return Float64(Float64(fma(a2, a2, Float64(a1 * a1)) / sqrt(2.0)) * cos(th))
          end
          
          code[a1_, a2_, th_] := N[(N[(N[(a2 * a2 + N[(a1 * a1), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}} \cdot \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-+.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \frac{\color{blue}{a2 \cdot a2} + a1 \cdot a1}{\sqrt{2}} \cdot \cos th \]
            15. lower-fma.f6499.7

              \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}}{\sqrt{2}} \cdot \cos th \]
          4. Applied rewrites99.7%

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

          Alternative 5: 57.2% accurate, 2.0× speedup?

          \[\begin{array}{l} \\ \frac{a2 \cdot a2}{\sqrt{2}} \cdot \cos th \end{array} \]
          (FPCore (a1 a2 th) :precision binary64 (* (/ (* a2 a2) (sqrt 2.0)) (cos th)))
          double code(double a1, double a2, double th) {
          	return ((a2 * a2) / sqrt(2.0)) * cos(th);
          }
          
          real(8) function code(a1, a2, th)
              real(8), intent (in) :: a1
              real(8), intent (in) :: a2
              real(8), intent (in) :: th
              code = ((a2 * a2) / sqrt(2.0d0)) * cos(th)
          end function
          
          public static double code(double a1, double a2, double th) {
          	return ((a2 * a2) / Math.sqrt(2.0)) * Math.cos(th);
          }
          
          def code(a1, a2, th):
          	return ((a2 * a2) / math.sqrt(2.0)) * math.cos(th)
          
          function code(a1, a2, th)
          	return Float64(Float64(Float64(a2 * a2) / sqrt(2.0)) * cos(th))
          end
          
          function tmp = code(a1, a2, th)
          	tmp = ((a2 * a2) / sqrt(2.0)) * cos(th);
          end
          
          code[a1_, a2_, th_] := N[(N[(N[(a2 * a2), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \frac{a2 \cdot a2}{\sqrt{2}} \cdot \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-+.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \frac{\color{blue}{a2 \cdot a2} + a1 \cdot a1}{\sqrt{2}} \cdot \cos th \]
            15. lower-fma.f6499.7

              \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}}{\sqrt{2}} \cdot \cos th \]
          4. Applied rewrites99.7%

            \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}} \cdot \cos th} \]
          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-*.f6461.1

              \[\leadsto \frac{\color{blue}{a2 \cdot a2}}{\sqrt{2}} \cdot \cos th \]
          7. Applied rewrites61.1%

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

          Alternative 6: 57.1% accurate, 2.0× speedup?

          \[\begin{array}{l} \\ \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \end{array} \]
          (FPCore (a1 a2 th) :precision binary64 (* (/ (cos th) (sqrt 2.0)) (* a2 a2)))
          double code(double a1, double a2, double th) {
          	return (cos(th) / sqrt(2.0)) * (a2 * a2);
          }
          
          real(8) function code(a1, a2, th)
              real(8), intent (in) :: a1
              real(8), intent (in) :: a2
              real(8), intent (in) :: th
              code = (cos(th) / sqrt(2.0d0)) * (a2 * a2)
          end function
          
          public static double code(double a1, double a2, double th) {
          	return (Math.cos(th) / Math.sqrt(2.0)) * (a2 * a2);
          }
          
          def code(a1, a2, th):
          	return (math.cos(th) / math.sqrt(2.0)) * (a2 * a2)
          
          function code(a1, a2, th)
          	return Float64(Float64(cos(th) / sqrt(2.0)) * Float64(a2 * a2))
          end
          
          function tmp = code(a1, a2, th)
          	tmp = (cos(th) / sqrt(2.0)) * (a2 * a2);
          end
          
          code[a1_, a2_, th_] := N[(N[(N[Cos[th], $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[(a2 * a2), $MachinePrecision]), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)
          \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 a1 around 0

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

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

              \[\leadsto \frac{\cos th \cdot \color{blue}{\left(a2 \cdot a2\right)}}{\sqrt{2}} \]
            3. associate-*r*N/A

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

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

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

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

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

              \[\leadsto \left(\cos th \cdot a2\right) \cdot \color{blue}{\frac{a2}{\sqrt{2}}} \]
            9. lower-sqrt.f6461.0

              \[\leadsto \left(\cos th \cdot a2\right) \cdot \frac{a2}{\color{blue}{\sqrt{2}}} \]
          5. Applied rewrites61.0%

            \[\leadsto \color{blue}{\left(\cos th \cdot a2\right) \cdot \frac{a2}{\sqrt{2}}} \]
          6. Step-by-step derivation
            1. Applied rewrites61.0%

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

            Alternative 7: 57.2% accurate, 2.0× speedup?

            \[\begin{array}{l} \\ \left(\frac{a2}{\sqrt{2}} \cdot \cos th\right) \cdot a2 \end{array} \]
            (FPCore (a1 a2 th) :precision binary64 (* (* (/ a2 (sqrt 2.0)) (cos th)) a2))
            double code(double a1, double a2, double th) {
            	return ((a2 / sqrt(2.0)) * cos(th)) * a2;
            }
            
            real(8) function code(a1, a2, th)
                real(8), intent (in) :: a1
                real(8), intent (in) :: a2
                real(8), intent (in) :: th
                code = ((a2 / sqrt(2.0d0)) * cos(th)) * a2
            end function
            
            public static double code(double a1, double a2, double th) {
            	return ((a2 / Math.sqrt(2.0)) * Math.cos(th)) * a2;
            }
            
            def code(a1, a2, th):
            	return ((a2 / math.sqrt(2.0)) * math.cos(th)) * a2
            
            function code(a1, a2, th)
            	return Float64(Float64(Float64(a2 / sqrt(2.0)) * cos(th)) * a2)
            end
            
            function tmp = code(a1, a2, th)
            	tmp = ((a2 / sqrt(2.0)) * cos(th)) * a2;
            end
            
            code[a1_, a2_, th_] := N[(N[(N[(a2 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision] * a2), $MachinePrecision]
            
            \begin{array}{l}
            
            \\
            \left(\frac{a2}{\sqrt{2}} \cdot \cos th\right) \cdot a2
            \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 a1 around 0

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

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

                \[\leadsto \frac{\cos th \cdot \color{blue}{\left(a2 \cdot a2\right)}}{\sqrt{2}} \]
              3. associate-*r*N/A

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

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

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

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

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

                \[\leadsto \left(\cos th \cdot a2\right) \cdot \color{blue}{\frac{a2}{\sqrt{2}}} \]
              9. lower-sqrt.f6461.0

                \[\leadsto \left(\cos th \cdot a2\right) \cdot \frac{a2}{\color{blue}{\sqrt{2}}} \]
            5. Applied rewrites61.0%

              \[\leadsto \color{blue}{\left(\cos th \cdot a2\right) \cdot \frac{a2}{\sqrt{2}}} \]
            6. Step-by-step derivation
              1. Applied rewrites61.0%

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

              Alternative 8: 57.2% accurate, 2.0× speedup?

              \[\begin{array}{l} \\ \left(\cos th \cdot a2\right) \cdot \frac{a2}{\sqrt{2}} \end{array} \]
              (FPCore (a1 a2 th) :precision binary64 (* (* (cos th) a2) (/ a2 (sqrt 2.0))))
              double code(double a1, double a2, double th) {
              	return (cos(th) * a2) * (a2 / sqrt(2.0));
              }
              
              real(8) function code(a1, a2, th)
                  real(8), intent (in) :: a1
                  real(8), intent (in) :: a2
                  real(8), intent (in) :: th
                  code = (cos(th) * a2) * (a2 / sqrt(2.0d0))
              end function
              
              public static double code(double a1, double a2, double th) {
              	return (Math.cos(th) * a2) * (a2 / Math.sqrt(2.0));
              }
              
              def code(a1, a2, th):
              	return (math.cos(th) * a2) * (a2 / math.sqrt(2.0))
              
              function code(a1, a2, th)
              	return Float64(Float64(cos(th) * a2) * Float64(a2 / sqrt(2.0)))
              end
              
              function tmp = code(a1, a2, th)
              	tmp = (cos(th) * a2) * (a2 / sqrt(2.0));
              end
              
              code[a1_, a2_, th_] := N[(N[(N[Cos[th], $MachinePrecision] * a2), $MachinePrecision] * N[(a2 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
              
              \begin{array}{l}
              
              \\
              \left(\cos th \cdot a2\right) \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 a1 around 0

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

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

                  \[\leadsto \frac{\cos th \cdot \color{blue}{\left(a2 \cdot a2\right)}}{\sqrt{2}} \]
                3. associate-*r*N/A

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

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

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

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

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

                  \[\leadsto \left(\cos th \cdot a2\right) \cdot \color{blue}{\frac{a2}{\sqrt{2}}} \]
                9. lower-sqrt.f6461.0

                  \[\leadsto \left(\cos th \cdot a2\right) \cdot \frac{a2}{\color{blue}{\sqrt{2}}} \]
              5. Applied rewrites61.0%

                \[\leadsto \color{blue}{\left(\cos th \cdot a2\right) \cdot \frac{a2}{\sqrt{2}}} \]
              6. Add Preprocessing

              Alternative 9: 66.3% accurate, 8.1× speedup?

              \[\begin{array}{l} \\ \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}} \end{array} \]
              (FPCore (a1 a2 th) :precision binary64 (/ (fma a2 a2 (* a1 a1)) (sqrt 2.0)))
              double code(double a1, double a2, double th) {
              	return fma(a2, a2, (a1 * a1)) / sqrt(2.0);
              }
              
              function code(a1, a2, th)
              	return Float64(fma(a2, a2, Float64(a1 * a1)) / sqrt(2.0))
              end
              
              code[a1_, a2_, th_] := N[(N[(a2 * a2 + N[(a1 * a1), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]
              
              \begin{array}{l}
              
              \\
              \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\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-+.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

                  \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\frac{\sqrt{2}}{\cos th}}} \]
              4. Applied rewrites99.7%

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

                \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
              6. Step-by-step derivation
                1. lower-sqrt.f6465.6

                  \[\leadsto \frac{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\color{blue}{\sqrt{2}}} \]
              7. Applied rewrites65.6%

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

              Alternative 10: 39.3% accurate, 9.9× speedup?

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

                \[\leadsto \color{blue}{\frac{{a1}^{2}}{\sqrt{2}} + \frac{{a2}^{2}}{\sqrt{2}}} \]
              4. Step-by-step derivation
                1. unpow2N/A

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

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

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

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

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

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

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

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

                  \[\leadsto \mathsf{fma}\left(\frac{a1}{\sqrt{2}}, a1, \color{blue}{\frac{a2}{\sqrt{2}}} \cdot a2\right) \]
                10. lower-sqrt.f6465.6

                  \[\leadsto \mathsf{fma}\left(\frac{a1}{\sqrt{2}}, a1, \frac{a2}{\color{blue}{\sqrt{2}}} \cdot a2\right) \]
              5. Applied rewrites65.6%

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

                \[\leadsto \frac{{a2}^{2}}{\color{blue}{\sqrt{2}}} \]
              7. Step-by-step derivation
                1. Applied rewrites40.1%

                  \[\leadsto a2 \cdot \color{blue}{\frac{a2}{\sqrt{2}}} \]
                2. Final simplification40.1%

                  \[\leadsto \frac{a2}{\sqrt{2}} \cdot a2 \]
                3. Add Preprocessing

                Alternative 11: 40.4% accurate, 9.9× speedup?

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

                  \[\leadsto \color{blue}{\frac{{a1}^{2}}{\sqrt{2}} + \frac{{a2}^{2}}{\sqrt{2}}} \]
                4. Step-by-step derivation
                  1. unpow2N/A

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

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

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

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

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

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

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

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

                    \[\leadsto \mathsf{fma}\left(\frac{a1}{\sqrt{2}}, a1, \color{blue}{\frac{a2}{\sqrt{2}}} \cdot a2\right) \]
                  10. lower-sqrt.f6465.6

                    \[\leadsto \mathsf{fma}\left(\frac{a1}{\sqrt{2}}, a1, \frac{a2}{\color{blue}{\sqrt{2}}} \cdot a2\right) \]
                5. Applied rewrites65.6%

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

                  \[\leadsto \frac{{a1}^{2}}{\color{blue}{\sqrt{2}}} \]
                7. Step-by-step derivation
                  1. Applied rewrites39.2%

                    \[\leadsto a1 \cdot \color{blue}{\frac{a1}{\sqrt{2}}} \]
                  2. Final simplification39.2%

                    \[\leadsto \frac{a1}{\sqrt{2}} \cdot a1 \]
                  3. Add Preprocessing

                  Reproduce

                  ?
                  herbie shell --seed 2024288 
                  (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))))