Migdal et al, Equation (64)

Percentage Accurate: 99.6% → 99.6%
Time: 4.0s
Alternatives: 8
Speedup: 1.8×

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));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

real(8) function code(a1, a2, th)
use fmin_fmax_functions
    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}

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 8 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: 99.6% 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));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

real(8) function code(a1, a2, th)
use fmin_fmax_functions
    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, 1.7× speedup?

\[\begin{array}{l} \\ \left(\sqrt{2} \cdot \left(\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \cos th\right)\right) \cdot 0.5 \end{array} \]
(FPCore (a1 a2 th)
 :precision binary64
 (* (* (sqrt 2.0) (* (fma a2 a2 (* a1 a1)) (cos th))) 0.5))
double code(double a1, double a2, double th) {
	return (sqrt(2.0) * (fma(a2, a2, (a1 * a1)) * cos(th))) * 0.5;
}
function code(a1, a2, th)
	return Float64(Float64(sqrt(2.0) * Float64(fma(a2, a2, Float64(a1 * a1)) * cos(th))) * 0.5)
end
code[a1_, a2_, th_] := N[(N[(N[Sqrt[2.0], $MachinePrecision] * N[(N[(a2 * a2 + N[(a1 * a1), $MachinePrecision]), $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision]
\begin{array}{l}

\\
\left(\sqrt{2} \cdot \left(\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \cos th\right)\right) \cdot 0.5
\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. 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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \left(\left(\cos th \cdot \left(a2 \cdot a2\right)\right) \cdot \sqrt{2} + \left(\cos th \cdot \left(a1 \cdot a1\right)\right) \cdot \sqrt{2}\right) \cdot \color{blue}{\frac{1}{2}} \]
  3. Applied rewrites99.6%

    \[\leadsto \color{blue}{\left(\sqrt{2} \cdot \left(\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \cos th\right)\right) \cdot 0.5} \]
  4. Add Preprocessing

Alternative 2: 99.6% accurate, 1.7× speedup?

\[\begin{array}{l} \\ \left(\left(\sqrt{2} \cdot \cos th\right) \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot 0.5 \end{array} \]
(FPCore (a1 a2 th)
 :precision binary64
 (* (* (* (sqrt 2.0) (cos th)) (fma a2 a2 (* a1 a1))) 0.5))
double code(double a1, double a2, double th) {
	return ((sqrt(2.0) * cos(th)) * fma(a2, a2, (a1 * a1))) * 0.5;
}
function code(a1, a2, th)
	return Float64(Float64(Float64(sqrt(2.0) * cos(th)) * fma(a2, a2, Float64(a1 * a1))) * 0.5)
end
code[a1_, a2_, th_] := N[(N[(N[(N[Sqrt[2.0], $MachinePrecision] * N[Cos[th], $MachinePrecision]), $MachinePrecision] * N[(a2 * a2 + N[(a1 * a1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision]
\begin{array}{l}

\\
\left(\left(\sqrt{2} \cdot \cos th\right) \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot 0.5
\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. 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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \left(\left(\cos th \cdot \left(a2 \cdot a2\right)\right) \cdot \sqrt{2} + \left(\cos th \cdot \left(a1 \cdot a1\right)\right) \cdot \sqrt{2}\right) \cdot \color{blue}{\frac{1}{2}} \]
  3. Applied rewrites99.6%

    \[\leadsto \color{blue}{\left(\sqrt{2} \cdot \left(\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \cos th\right)\right) \cdot 0.5} \]
  4. Step-by-step derivation
    1. lift-*.f64N/A

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

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

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

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

      \[\leadsto \color{blue}{\left(\left(\sqrt{2} \cdot \cos th\right) \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right)} \cdot \frac{1}{2} \]
    6. lower-*.f6499.6

      \[\leadsto \left(\color{blue}{\left(\sqrt{2} \cdot \cos th\right)} \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot 0.5 \]
  5. Applied rewrites99.6%

    \[\leadsto \color{blue}{\left(\left(\sqrt{2} \cdot \cos th\right) \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot 0.5} \]
  6. Add Preprocessing

Alternative 3: 99.6% accurate, 1.8× speedup?

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

\\
\cos th \cdot \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. 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. associate-*l/N/A

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

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

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

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

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

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

      \[\leadsto \cos th \cdot \frac{\color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}}{\sqrt{2}} \]
  3. Applied rewrites99.6%

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

Alternative 4: 77.6% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{\cos th}{\sqrt{2}}\\ t_2 := \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\\ \mathbf{if}\;t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right) \leq -5 \cdot 10^{-256}:\\ \;\;\;\;\left(\left(\mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot t\_2\right) \cdot \sqrt{2}\right) \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{1 \cdot t\_2}{\sqrt{2}}\\ \end{array} \end{array} \]
(FPCore (a1 a2 th)
 :precision binary64
 (let* ((t_1 (/ (cos th) (sqrt 2.0))) (t_2 (fma a2 a2 (* a1 a1))))
   (if (<= (+ (* t_1 (* a1 a1)) (* t_1 (* a2 a2))) -5e-256)
     (* (* (* (fma (* th th) -0.5 1.0) t_2) (sqrt 2.0)) 0.5)
     (/ (* 1.0 t_2) (sqrt 2.0)))))
double code(double a1, double a2, double th) {
	double t_1 = cos(th) / sqrt(2.0);
	double t_2 = fma(a2, a2, (a1 * a1));
	double tmp;
	if (((t_1 * (a1 * a1)) + (t_1 * (a2 * a2))) <= -5e-256) {
		tmp = ((fma((th * th), -0.5, 1.0) * t_2) * sqrt(2.0)) * 0.5;
	} else {
		tmp = (1.0 * t_2) / sqrt(2.0);
	}
	return tmp;
}
function code(a1, a2, th)
	t_1 = Float64(cos(th) / sqrt(2.0))
	t_2 = fma(a2, a2, Float64(a1 * a1))
	tmp = 0.0
	if (Float64(Float64(t_1 * Float64(a1 * a1)) + Float64(t_1 * Float64(a2 * a2))) <= -5e-256)
		tmp = Float64(Float64(Float64(fma(Float64(th * th), -0.5, 1.0) * t_2) * sqrt(2.0)) * 0.5);
	else
		tmp = Float64(Float64(1.0 * t_2) / 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]}, Block[{t$95$2 = N[(a2 * a2 + N[(a1 * a1), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(t$95$1 * N[(a1 * a1), $MachinePrecision]), $MachinePrecision] + N[(t$95$1 * N[(a2 * a2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -5e-256], N[(N[(N[(N[(N[(th * th), $MachinePrecision] * -0.5 + 1.0), $MachinePrecision] * t$95$2), $MachinePrecision] * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision], N[(N[(1.0 * t$95$2), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{\cos th}{\sqrt{2}}\\
t_2 := \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\\
\mathbf{if}\;t\_1 \cdot \left(a1 \cdot a1\right) + t\_1 \cdot \left(a2 \cdot a2\right) \leq -5 \cdot 10^{-256}:\\
\;\;\;\;\left(\left(\mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot t\_2\right) \cdot \sqrt{2}\right) \cdot 0.5\\

\mathbf{else}:\\
\;\;\;\;\frac{1 \cdot t\_2}{\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))) < -5e-256

    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. 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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(\left(\cos th \cdot \left(a2 \cdot a2\right)\right) \cdot \sqrt{2} + \left(\cos th \cdot \left(a1 \cdot a1\right)\right) \cdot \sqrt{2}\right) \cdot \color{blue}{\frac{1}{2}} \]
    3. Applied rewrites99.6%

      \[\leadsto \color{blue}{\left(\sqrt{2} \cdot \left(\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \cos th\right)\right) \cdot 0.5} \]
    4. Step-by-step derivation
      1. lift-*.f64N/A

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

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

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

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

        \[\leadsto \color{blue}{\left(\left(\sqrt{2} \cdot \cos th\right) \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right)} \cdot \frac{1}{2} \]
      6. lower-*.f6499.6

        \[\leadsto \left(\color{blue}{\left(\sqrt{2} \cdot \cos th\right)} \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot 0.5 \]
    5. Applied rewrites99.6%

      \[\leadsto \color{blue}{\left(\left(\sqrt{2} \cdot \cos th\right) \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot 0.5} \]
    6. Taylor expanded in th around 0

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

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

        \[\leadsto \left(\left(\sqrt{2} \cdot \left(1 + \frac{-1}{2} \cdot \color{blue}{{th}^{2}}\right)\right) \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot \frac{1}{2} \]
      3. lower-pow.f6462.9

        \[\leadsto \left(\left(\sqrt{2} \cdot \left(1 + -0.5 \cdot {th}^{\color{blue}{2}}\right)\right) \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot 0.5 \]
    8. Applied rewrites62.9%

      \[\leadsto \left(\left(\sqrt{2} \cdot \color{blue}{\left(1 + -0.5 \cdot {th}^{2}\right)}\right) \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot 0.5 \]
    9. Step-by-step derivation
      1. lift-*.f64N/A

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

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

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

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

        \[\leadsto \color{blue}{\left(\left(\left(1 + \frac{-1}{2} \cdot {th}^{2}\right) \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot \sqrt{2}\right)} \cdot \frac{1}{2} \]
      6. lower-*.f6462.9

        \[\leadsto \left(\color{blue}{\left(\left(1 + -0.5 \cdot {th}^{2}\right) \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right)} \cdot \sqrt{2}\right) \cdot 0.5 \]
      7. lift-+.f64N/A

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

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

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

        \[\leadsto \left(\left(\left({th}^{2} \cdot \frac{-1}{2} + 1\right) \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot \sqrt{2}\right) \cdot \frac{1}{2} \]
      11. lower-fma.f6462.9

        \[\leadsto \left(\left(\mathsf{fma}\left({th}^{2}, \color{blue}{-0.5}, 1\right) \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot \sqrt{2}\right) \cdot 0.5 \]
      12. lift-pow.f64N/A

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

        \[\leadsto \left(\left(\mathsf{fma}\left(th \cdot th, \frac{-1}{2}, 1\right) \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot \sqrt{2}\right) \cdot \frac{1}{2} \]
      14. lower-*.f6462.9

        \[\leadsto \left(\left(\mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot \sqrt{2}\right) \cdot 0.5 \]
    10. Applied rewrites62.9%

      \[\leadsto \color{blue}{\left(\left(\mathsf{fma}\left(th \cdot th, -0.5, 1\right) \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot \sqrt{2}\right)} \cdot 0.5 \]

    if -5e-256 < (+.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. Taylor expanded in th around 0

      \[\leadsto \frac{\color{blue}{1}}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
    3. Step-by-step derivation
      1. Applied rewrites82.4%

        \[\leadsto \frac{\color{blue}{1}}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      2. Taylor expanded in th around 0

        \[\leadsto \frac{1}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\color{blue}{1}}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      3. Step-by-step derivation
        1. Applied rewrites66.3%

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

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

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

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

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

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

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

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

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

            \[\leadsto \color{blue}{\frac{1 \cdot \left(a1 \cdot a1\right) + 1 \cdot \left(a2 \cdot a2\right)}{\sqrt{2}}} \]
          10. distribute-lft-outN/A

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

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

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

            \[\leadsto \frac{1 \cdot \color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}}{\sqrt{2}} \]
          14. lower-*.f6466.4

            \[\leadsto \frac{\color{blue}{1 \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}}{\sqrt{2}} \]
        3. Applied rewrites66.4%

          \[\leadsto \color{blue}{\frac{1 \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}}} \]
      4. Recombined 2 regimes into one program.
      5. Add Preprocessing

      Alternative 5: 66.4% accurate, 5.3× speedup?

      \[\begin{array}{l} \\ \frac{1 \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}{\sqrt{2}} \end{array} \]
      (FPCore (a1 a2 th)
       :precision binary64
       (/ (* 1.0 (fma a2 a2 (* a1 a1))) (sqrt 2.0)))
      double code(double a1, double a2, double th) {
      	return (1.0 * fma(a2, a2, (a1 * a1))) / sqrt(2.0);
      }
      
      function code(a1, a2, th)
      	return Float64(Float64(1.0 * fma(a2, a2, Float64(a1 * a1))) / sqrt(2.0))
      end
      
      code[a1_, a2_, th_] := N[(N[(1.0 * N[(a2 * a2 + N[(a1 * a1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \frac{1 \cdot \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. Taylor expanded in th around 0

        \[\leadsto \frac{\color{blue}{1}}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
      3. Step-by-step derivation
        1. Applied rewrites82.4%

          \[\leadsto \frac{\color{blue}{1}}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
        2. Taylor expanded in th around 0

          \[\leadsto \frac{1}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\color{blue}{1}}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
        3. Step-by-step derivation
          1. Applied rewrites66.3%

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

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

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

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

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

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

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

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

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

              \[\leadsto \color{blue}{\frac{1 \cdot \left(a1 \cdot a1\right) + 1 \cdot \left(a2 \cdot a2\right)}{\sqrt{2}}} \]
            10. distribute-lft-outN/A

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

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

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

              \[\leadsto \frac{1 \cdot \color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}}{\sqrt{2}} \]
            14. lower-*.f6466.4

              \[\leadsto \frac{\color{blue}{1 \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)}}{\sqrt{2}} \]
          3. Applied rewrites66.4%

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

          Alternative 6: 66.4% accurate, 5.4× speedup?

          \[\begin{array}{l} \\ \left(\sqrt{2} \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot 0.5 \end{array} \]
          (FPCore (a1 a2 th)
           :precision binary64
           (* (* (sqrt 2.0) (fma a2 a2 (* a1 a1))) 0.5))
          double code(double a1, double a2, double th) {
          	return (sqrt(2.0) * fma(a2, a2, (a1 * a1))) * 0.5;
          }
          
          function code(a1, a2, th)
          	return Float64(Float64(sqrt(2.0) * fma(a2, a2, Float64(a1 * a1))) * 0.5)
          end
          
          code[a1_, a2_, th_] := N[(N[(N[Sqrt[2.0], $MachinePrecision] * N[(a2 * a2 + N[(a1 * a1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \left(\sqrt{2} \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot 0.5
          \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. 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

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

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \left(\left(\cos th \cdot \left(a2 \cdot a2\right)\right) \cdot \sqrt{2} + \left(\cos th \cdot \left(a1 \cdot a1\right)\right) \cdot \sqrt{2}\right) \cdot \color{blue}{\frac{1}{2}} \]
          3. Applied rewrites99.6%

            \[\leadsto \color{blue}{\left(\sqrt{2} \cdot \left(\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \cos th\right)\right) \cdot 0.5} \]
          4. Step-by-step derivation
            1. lift-*.f64N/A

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

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

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

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

              \[\leadsto \color{blue}{\left(\left(\sqrt{2} \cdot \cos th\right) \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right)} \cdot \frac{1}{2} \]
            6. lower-*.f6499.6

              \[\leadsto \left(\color{blue}{\left(\sqrt{2} \cdot \cos th\right)} \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot 0.5 \]
          5. Applied rewrites99.6%

            \[\leadsto \color{blue}{\left(\left(\sqrt{2} \cdot \cos th\right) \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot 0.5} \]
          6. Taylor expanded in th around 0

            \[\leadsto \left(\color{blue}{\sqrt{2}} \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot \frac{1}{2} \]
          7. Step-by-step derivation
            1. lower-sqrt.f6466.4

              \[\leadsto \left(\sqrt{2} \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot 0.5 \]
          8. Applied rewrites66.4%

            \[\leadsto \left(\color{blue}{\sqrt{2}} \cdot \mathsf{fma}\left(a2, a2, a1 \cdot a1\right)\right) \cdot 0.5 \]
          9. Add Preprocessing

          Alternative 7: 40.6% accurate, 7.4× speedup?

          \[\begin{array}{l} \\ \frac{1 \cdot \left(a2 \cdot a2\right)}{\sqrt{2}} \end{array} \]
          (FPCore (a1 a2 th) :precision binary64 (/ (* 1.0 (* a2 a2)) (sqrt 2.0)))
          double code(double a1, double a2, double th) {
          	return (1.0 * (a2 * a2)) / sqrt(2.0);
          }
          
          module fmin_fmax_functions
              implicit none
              private
              public fmax
              public fmin
          
              interface fmax
                  module procedure fmax88
                  module procedure fmax44
                  module procedure fmax84
                  module procedure fmax48
              end interface
              interface fmin
                  module procedure fmin88
                  module procedure fmin44
                  module procedure fmin84
                  module procedure fmin48
              end interface
          contains
              real(8) function fmax88(x, y) result (res)
                  real(8), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
              end function
              real(4) function fmax44(x, y) result (res)
                  real(4), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
              end function
              real(8) function fmax84(x, y) result(res)
                  real(8), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
              end function
              real(8) function fmax48(x, y) result(res)
                  real(4), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
              end function
              real(8) function fmin88(x, y) result (res)
                  real(8), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
              end function
              real(4) function fmin44(x, y) result (res)
                  real(4), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
              end function
              real(8) function fmin84(x, y) result(res)
                  real(8), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
              end function
              real(8) function fmin48(x, y) result(res)
                  real(4), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
              end function
          end module
          
          real(8) function code(a1, a2, th)
          use fmin_fmax_functions
              real(8), intent (in) :: a1
              real(8), intent (in) :: a2
              real(8), intent (in) :: th
              code = (1.0d0 * (a2 * a2)) / sqrt(2.0d0)
          end function
          
          public static double code(double a1, double a2, double th) {
          	return (1.0 * (a2 * a2)) / Math.sqrt(2.0);
          }
          
          def code(a1, a2, th):
          	return (1.0 * (a2 * a2)) / math.sqrt(2.0)
          
          function code(a1, a2, th)
          	return Float64(Float64(1.0 * Float64(a2 * a2)) / sqrt(2.0))
          end
          
          function tmp = code(a1, a2, th)
          	tmp = (1.0 * (a2 * a2)) / sqrt(2.0);
          end
          
          code[a1_, a2_, th_] := N[(N[(1.0 * N[(a2 * a2), $MachinePrecision]), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \frac{1 \cdot \left(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. Taylor expanded in th around 0

            \[\leadsto \frac{\color{blue}{1}}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
          3. Step-by-step derivation
            1. Applied rewrites82.4%

              \[\leadsto \frac{\color{blue}{1}}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
            2. Taylor expanded in th around 0

              \[\leadsto \frac{1}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\color{blue}{1}}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
            3. Step-by-step derivation
              1. Applied rewrites66.3%

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

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

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

                  \[\leadsto \frac{1}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
                4. distribute-lft-outN/A

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

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

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

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

                  \[\leadsto \color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \frac{1}{\sqrt{2}}} \]
                9. lower-*.f6466.3

                  \[\leadsto \color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \frac{1}{\sqrt{2}}} \]
              3. Applied rewrites66.3%

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

                \[\leadsto \color{blue}{{a2}^{2}} \cdot \frac{1}{\sqrt{2}} \]
              5. Step-by-step derivation
                1. lower-pow.f6440.5

                  \[\leadsto {a2}^{\color{blue}{2}} \cdot \frac{1}{\sqrt{2}} \]
              6. Applied rewrites40.5%

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

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

                  \[\leadsto {a2}^{2} \cdot \color{blue}{\frac{1}{\sqrt{2}}} \]
                3. associate-*r/N/A

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

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

                  \[\leadsto \frac{\color{blue}{1 \cdot {a2}^{2}}}{\sqrt{2}} \]
                6. lower-*.f6440.6

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

                  \[\leadsto \frac{1 \cdot {a2}^{\color{blue}{2}}}{\sqrt{2}} \]
                8. pow2N/A

                  \[\leadsto \frac{1 \cdot \left(a2 \cdot \color{blue}{a2}\right)}{\sqrt{2}} \]
                9. lift-*.f6440.6

                  \[\leadsto \frac{1 \cdot \left(a2 \cdot \color{blue}{a2}\right)}{\sqrt{2}} \]
              8. Applied rewrites40.6%

                \[\leadsto \color{blue}{\frac{1 \cdot \left(a2 \cdot a2\right)}{\sqrt{2}}} \]
              9. Add Preprocessing

              Alternative 8: 40.5% accurate, 7.4× speedup?

              \[\begin{array}{l} \\ \frac{1}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \end{array} \]
              (FPCore (a1 a2 th) :precision binary64 (* (/ 1.0 (sqrt 2.0)) (* a2 a2)))
              double code(double a1, double a2, double th) {
              	return (1.0 / sqrt(2.0)) * (a2 * a2);
              }
              
              module fmin_fmax_functions
                  implicit none
                  private
                  public fmax
                  public fmin
              
                  interface fmax
                      module procedure fmax88
                      module procedure fmax44
                      module procedure fmax84
                      module procedure fmax48
                  end interface
                  interface fmin
                      module procedure fmin88
                      module procedure fmin44
                      module procedure fmin84
                      module procedure fmin48
                  end interface
              contains
                  real(8) function fmax88(x, y) result (res)
                      real(8), intent (in) :: x
                      real(8), intent (in) :: y
                      res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                  end function
                  real(4) function fmax44(x, y) result (res)
                      real(4), intent (in) :: x
                      real(4), intent (in) :: y
                      res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                  end function
                  real(8) function fmax84(x, y) result(res)
                      real(8), intent (in) :: x
                      real(4), intent (in) :: y
                      res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                  end function
                  real(8) function fmax48(x, y) result(res)
                      real(4), intent (in) :: x
                      real(8), intent (in) :: y
                      res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                  end function
                  real(8) function fmin88(x, y) result (res)
                      real(8), intent (in) :: x
                      real(8), intent (in) :: y
                      res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                  end function
                  real(4) function fmin44(x, y) result (res)
                      real(4), intent (in) :: x
                      real(4), intent (in) :: y
                      res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                  end function
                  real(8) function fmin84(x, y) result(res)
                      real(8), intent (in) :: x
                      real(4), intent (in) :: y
                      res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                  end function
                  real(8) function fmin48(x, y) result(res)
                      real(4), intent (in) :: x
                      real(8), intent (in) :: y
                      res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                  end function
              end module
              
              real(8) function code(a1, a2, th)
              use fmin_fmax_functions
                  real(8), intent (in) :: a1
                  real(8), intent (in) :: a2
                  real(8), intent (in) :: th
                  code = (1.0d0 / sqrt(2.0d0)) * (a2 * a2)
              end function
              
              public static double code(double a1, double a2, double th) {
              	return (1.0 / Math.sqrt(2.0)) * (a2 * a2);
              }
              
              def code(a1, a2, th):
              	return (1.0 / math.sqrt(2.0)) * (a2 * a2)
              
              function code(a1, a2, th)
              	return Float64(Float64(1.0 / sqrt(2.0)) * Float64(a2 * a2))
              end
              
              function tmp = code(a1, a2, th)
              	tmp = (1.0 / sqrt(2.0)) * (a2 * a2);
              end
              
              code[a1_, a2_, th_] := N[(N[(1.0 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[(a2 * a2), $MachinePrecision]), $MachinePrecision]
              
              \begin{array}{l}
              
              \\
              \frac{1}{\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. Taylor expanded in th around 0

                \[\leadsto \frac{\color{blue}{1}}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
              3. Step-by-step derivation
                1. Applied rewrites82.4%

                  \[\leadsto \frac{\color{blue}{1}}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
                2. Taylor expanded in th around 0

                  \[\leadsto \frac{1}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\color{blue}{1}}{\sqrt{2}} \cdot \left(a2 \cdot a2\right) \]
                3. Step-by-step derivation
                  1. Applied rewrites66.3%

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

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

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

                      \[\leadsto \frac{1}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
                    4. distribute-lft-outN/A

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

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

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

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

                      \[\leadsto \color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \frac{1}{\sqrt{2}}} \]
                    9. lower-*.f6466.3

                      \[\leadsto \color{blue}{\mathsf{fma}\left(a2, a2, a1 \cdot a1\right) \cdot \frac{1}{\sqrt{2}}} \]
                  3. Applied rewrites66.3%

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

                    \[\leadsto \color{blue}{{a2}^{2}} \cdot \frac{1}{\sqrt{2}} \]
                  5. Step-by-step derivation
                    1. lower-pow.f6440.5

                      \[\leadsto {a2}^{\color{blue}{2}} \cdot \frac{1}{\sqrt{2}} \]
                  6. Applied rewrites40.5%

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

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

                      \[\leadsto \color{blue}{\frac{1}{\sqrt{2}} \cdot {a2}^{2}} \]
                    3. lower-*.f6440.5

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

                      \[\leadsto \frac{1}{\sqrt{2}} \cdot {a2}^{\color{blue}{2}} \]
                    5. pow2N/A

                      \[\leadsto \frac{1}{\sqrt{2}} \cdot \left(a2 \cdot \color{blue}{a2}\right) \]
                    6. lift-*.f6440.5

                      \[\leadsto \frac{1}{\sqrt{2}} \cdot \left(a2 \cdot \color{blue}{a2}\right) \]
                  8. Applied rewrites40.5%

                    \[\leadsto \color{blue}{\frac{1}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)} \]
                  9. Add Preprocessing

                  Reproduce

                  ?
                  herbie shell --seed 2025159 
                  (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))))