cos2 (problem 3.4.1)

Percentage Accurate: 50.5% → 99.7%
Time: 3.2s
Alternatives: 7
Speedup: 41.8×

Specification

?
\[\begin{array}{l} \\ \frac{1 - \cos x}{x \cdot x} \end{array} \]
(FPCore (x) :precision binary64 (/ (- 1.0 (cos x)) (* x x)))
double code(double x) {
	return (1.0 - cos(x)) / (x * x);
}
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(x)
use fmin_fmax_functions
    real(8), intent (in) :: x
    code = (1.0d0 - cos(x)) / (x * x)
end function
public static double code(double x) {
	return (1.0 - Math.cos(x)) / (x * x);
}
def code(x):
	return (1.0 - math.cos(x)) / (x * x)
function code(x)
	return Float64(Float64(1.0 - cos(x)) / Float64(x * x))
end
function tmp = code(x)
	tmp = (1.0 - cos(x)) / (x * x);
end
code[x_] := N[(N[(1.0 - N[Cos[x], $MachinePrecision]), $MachinePrecision] / N[(x * x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1 - \cos x}{x \cdot x}
\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 7 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: 50.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{1 - \cos x}{x \cdot x} \end{array} \]
(FPCore (x) :precision binary64 (/ (- 1.0 (cos x)) (* x x)))
double code(double x) {
	return (1.0 - cos(x)) / (x * x);
}
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(x)
use fmin_fmax_functions
    real(8), intent (in) :: x
    code = (1.0d0 - cos(x)) / (x * x)
end function
public static double code(double x) {
	return (1.0 - Math.cos(x)) / (x * x);
}
def code(x):
	return (1.0 - math.cos(x)) / (x * x)
function code(x)
	return Float64(Float64(1.0 - cos(x)) / Float64(x * x))
end
function tmp = code(x)
	tmp = (1.0 - cos(x)) / (x * x);
end
code[x_] := N[(N[(1.0 - N[Cos[x], $MachinePrecision]), $MachinePrecision] / N[(x * x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1 - \cos x}{x \cdot x}
\end{array}

Alternative 1: 99.7% accurate, 0.6× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 0.102:\\ \;\;\;\;0.5 + {x\_m}^{2} \cdot \left({x\_m}^{2} \cdot \left(0.001388888888888889 + -2.48015873015873 \cdot 10^{-5} \cdot {x\_m}^{2}\right) - 0.041666666666666664\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(\frac{-1}{x\_m}, \cos x\_m, \frac{1}{x\_m}\right)}{x\_m}\\ \end{array} \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m)
 :precision binary64
 (if (<= x_m 0.102)
   (+
    0.5
    (*
     (pow x_m 2.0)
     (-
      (*
       (pow x_m 2.0)
       (+ 0.001388888888888889 (* -2.48015873015873e-5 (pow x_m 2.0))))
      0.041666666666666664)))
   (/ (fma (/ -1.0 x_m) (cos x_m) (/ 1.0 x_m)) x_m)))
x_m = fabs(x);
double code(double x_m) {
	double tmp;
	if (x_m <= 0.102) {
		tmp = 0.5 + (pow(x_m, 2.0) * ((pow(x_m, 2.0) * (0.001388888888888889 + (-2.48015873015873e-5 * pow(x_m, 2.0)))) - 0.041666666666666664));
	} else {
		tmp = fma((-1.0 / x_m), cos(x_m), (1.0 / x_m)) / x_m;
	}
	return tmp;
}
x_m = abs(x)
function code(x_m)
	tmp = 0.0
	if (x_m <= 0.102)
		tmp = Float64(0.5 + Float64((x_m ^ 2.0) * Float64(Float64((x_m ^ 2.0) * Float64(0.001388888888888889 + Float64(-2.48015873015873e-5 * (x_m ^ 2.0)))) - 0.041666666666666664)));
	else
		tmp = Float64(fma(Float64(-1.0 / x_m), cos(x_m), Float64(1.0 / x_m)) / x_m);
	end
	return tmp
end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := If[LessEqual[x$95$m, 0.102], N[(0.5 + N[(N[Power[x$95$m, 2.0], $MachinePrecision] * N[(N[(N[Power[x$95$m, 2.0], $MachinePrecision] * N[(0.001388888888888889 + N[(-2.48015873015873e-5 * N[Power[x$95$m, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - 0.041666666666666664), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[(-1.0 / x$95$m), $MachinePrecision] * N[Cos[x$95$m], $MachinePrecision] + N[(1.0 / x$95$m), $MachinePrecision]), $MachinePrecision] / x$95$m), $MachinePrecision]]
\begin{array}{l}
x_m = \left|x\right|

\\
\begin{array}{l}
\mathbf{if}\;x\_m \leq 0.102:\\
\;\;\;\;0.5 + {x\_m}^{2} \cdot \left({x\_m}^{2} \cdot \left(0.001388888888888889 + -2.48015873015873 \cdot 10^{-5} \cdot {x\_m}^{2}\right) - 0.041666666666666664\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{\mathsf{fma}\left(\frac{-1}{x\_m}, \cos x\_m, \frac{1}{x\_m}\right)}{x\_m}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 0.101999999999999993

    1. Initial program 50.5%

      \[\frac{1 - \cos x}{x \cdot x} \]
    2. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\frac{1}{2} + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{1}{720} + \frac{-1}{40320} \cdot {x}^{2}\right) - \frac{1}{24}\right)} \]
    3. Step-by-step derivation
      1. lower-+.f64N/A

        \[\leadsto \frac{1}{2} + \color{blue}{{x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{1}{720} + \frac{-1}{40320} \cdot {x}^{2}\right) - \frac{1}{24}\right)} \]
      2. lower-*.f64N/A

        \[\leadsto \frac{1}{2} + {x}^{2} \cdot \color{blue}{\left({x}^{2} \cdot \left(\frac{1}{720} + \frac{-1}{40320} \cdot {x}^{2}\right) - \frac{1}{24}\right)} \]
      3. lower-pow.f64N/A

        \[\leadsto \frac{1}{2} + {x}^{2} \cdot \left(\color{blue}{{x}^{2} \cdot \left(\frac{1}{720} + \frac{-1}{40320} \cdot {x}^{2}\right)} - \frac{1}{24}\right) \]
      4. lower--.f64N/A

        \[\leadsto \frac{1}{2} + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{1}{720} + \frac{-1}{40320} \cdot {x}^{2}\right) - \color{blue}{\frac{1}{24}}\right) \]
      5. lower-*.f64N/A

        \[\leadsto \frac{1}{2} + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{1}{720} + \frac{-1}{40320} \cdot {x}^{2}\right) - \frac{1}{24}\right) \]
      6. lower-pow.f64N/A

        \[\leadsto \frac{1}{2} + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{1}{720} + \frac{-1}{40320} \cdot {x}^{2}\right) - \frac{1}{24}\right) \]
      7. lower-+.f64N/A

        \[\leadsto \frac{1}{2} + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{1}{720} + \frac{-1}{40320} \cdot {x}^{2}\right) - \frac{1}{24}\right) \]
      8. lower-*.f64N/A

        \[\leadsto \frac{1}{2} + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{1}{720} + \frac{-1}{40320} \cdot {x}^{2}\right) - \frac{1}{24}\right) \]
      9. lower-pow.f6451.2

        \[\leadsto 0.5 + {x}^{2} \cdot \left({x}^{2} \cdot \left(0.001388888888888889 + -2.48015873015873 \cdot 10^{-5} \cdot {x}^{2}\right) - 0.041666666666666664\right) \]
    4. Applied rewrites51.2%

      \[\leadsto \color{blue}{0.5 + {x}^{2} \cdot \left({x}^{2} \cdot \left(0.001388888888888889 + -2.48015873015873 \cdot 10^{-5} \cdot {x}^{2}\right) - 0.041666666666666664\right)} \]

    if 0.101999999999999993 < x

    1. Initial program 50.5%

      \[\frac{1 - \cos x}{x \cdot x} \]
    2. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \color{blue}{\frac{1 - \cos x}{x \cdot x}} \]
      2. lift-*.f64N/A

        \[\leadsto \frac{1 - \cos x}{\color{blue}{x \cdot x}} \]
      3. associate-/r*N/A

        \[\leadsto \color{blue}{\frac{\frac{1 - \cos x}{x}}{x}} \]
      4. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{\frac{1 - \cos x}{x}}{x}} \]
      5. lower-/.f6451.6

        \[\leadsto \frac{\color{blue}{\frac{1 - \cos x}{x}}}{x} \]
    3. Applied rewrites51.6%

      \[\leadsto \color{blue}{\frac{\frac{1 - \cos x}{x}}{x}} \]
    4. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{1 - \cos x}{x}}}{x} \]
      2. lift--.f64N/A

        \[\leadsto \frac{\frac{\color{blue}{1 - \cos x}}{x}}{x} \]
      3. div-subN/A

        \[\leadsto \frac{\color{blue}{\frac{1}{x} - \frac{\cos x}{x}}}{x} \]
      4. lower--.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{1}{x} - \frac{\cos x}{x}}}{x} \]
      5. lower-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{1}{x}} - \frac{\cos x}{x}}{x} \]
      6. lower-/.f6451.5

        \[\leadsto \frac{\frac{1}{x} - \color{blue}{\frac{\cos x}{x}}}{x} \]
    5. Applied rewrites51.5%

      \[\leadsto \frac{\color{blue}{\frac{1}{x} - \frac{\cos x}{x}}}{x} \]
    6. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \frac{\frac{1}{x} - \color{blue}{\frac{\cos x}{x}}}{x} \]
      2. mult-flipN/A

        \[\leadsto \frac{\frac{1}{x} - \color{blue}{\cos x \cdot \frac{1}{x}}}{x} \]
      3. lift-/.f64N/A

        \[\leadsto \frac{\frac{1}{x} - \cos x \cdot \color{blue}{\frac{1}{x}}}{x} \]
      4. lower-*.f6451.5

        \[\leadsto \frac{\frac{1}{x} - \color{blue}{\cos x \cdot \frac{1}{x}}}{x} \]
    7. Applied rewrites51.5%

      \[\leadsto \frac{\frac{1}{x} - \color{blue}{\cos x \cdot \frac{1}{x}}}{x} \]
    8. Step-by-step derivation
      1. lift--.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{1}{x} - \cos x \cdot \frac{1}{x}}}{x} \]
      2. sub-flipN/A

        \[\leadsto \frac{\color{blue}{\frac{1}{x} + \left(\mathsf{neg}\left(\cos x \cdot \frac{1}{x}\right)\right)}}{x} \]
      3. lift-*.f64N/A

        \[\leadsto \frac{\frac{1}{x} + \left(\mathsf{neg}\left(\color{blue}{\cos x \cdot \frac{1}{x}}\right)\right)}{x} \]
      4. lift-/.f64N/A

        \[\leadsto \frac{\frac{1}{x} + \left(\mathsf{neg}\left(\cos x \cdot \color{blue}{\frac{1}{x}}\right)\right)}{x} \]
      5. mult-flip-revN/A

        \[\leadsto \frac{\frac{1}{x} + \left(\mathsf{neg}\left(\color{blue}{\frac{\cos x}{x}}\right)\right)}{x} \]
      6. distribute-frac-neg2N/A

        \[\leadsto \frac{\frac{1}{x} + \color{blue}{\frac{\cos x}{\mathsf{neg}\left(x\right)}}}{x} \]
      7. lift-neg.f64N/A

        \[\leadsto \frac{\frac{1}{x} + \frac{\cos x}{\color{blue}{-x}}}{x} \]
      8. lift-/.f64N/A

        \[\leadsto \frac{\frac{1}{x} + \color{blue}{\frac{\cos x}{-x}}}{x} \]
      9. +-commutativeN/A

        \[\leadsto \frac{\color{blue}{\frac{\cos x}{-x} + \frac{1}{x}}}{x} \]
      10. lift-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\cos x}{-x}} + \frac{1}{x}}{x} \]
      11. mult-flipN/A

        \[\leadsto \frac{\color{blue}{\cos x \cdot \frac{1}{-x}} + \frac{1}{x}}{x} \]
      12. *-commutativeN/A

        \[\leadsto \frac{\color{blue}{\frac{1}{-x} \cdot \cos x} + \frac{1}{x}}{x} \]
      13. lower-fma.f64N/A

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\frac{1}{-x}, \cos x, \frac{1}{x}\right)}}{x} \]
      14. frac-2negN/A

        \[\leadsto \frac{\mathsf{fma}\left(\color{blue}{\frac{\mathsf{neg}\left(1\right)}{\mathsf{neg}\left(\left(-x\right)\right)}}, \cos x, \frac{1}{x}\right)}{x} \]
      15. metadata-evalN/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\color{blue}{-1}}{\mathsf{neg}\left(\left(-x\right)\right)}, \cos x, \frac{1}{x}\right)}{x} \]
      16. lift-neg.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{-1}{\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right)}, \cos x, \frac{1}{x}\right)}{x} \]
      17. remove-double-negN/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{-1}{\color{blue}{x}}, \cos x, \frac{1}{x}\right)}{x} \]
      18. lower-/.f6451.6

        \[\leadsto \frac{\mathsf{fma}\left(\color{blue}{\frac{-1}{x}}, \cos x, \frac{1}{x}\right)}{x} \]
    9. Applied rewrites51.6%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\frac{-1}{x}, \cos x, \frac{1}{x}\right)}}{x} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 2: 99.6% accurate, 0.8× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 0.0055:\\ \;\;\;\;\mathsf{fma}\left(-0.041666666666666664 \cdot x\_m, x\_m, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(\frac{-1}{x\_m}, \cos x\_m, \frac{1}{x\_m}\right)}{x\_m}\\ \end{array} \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m)
 :precision binary64
 (if (<= x_m 0.0055)
   (fma (* -0.041666666666666664 x_m) x_m 0.5)
   (/ (fma (/ -1.0 x_m) (cos x_m) (/ 1.0 x_m)) x_m)))
x_m = fabs(x);
double code(double x_m) {
	double tmp;
	if (x_m <= 0.0055) {
		tmp = fma((-0.041666666666666664 * x_m), x_m, 0.5);
	} else {
		tmp = fma((-1.0 / x_m), cos(x_m), (1.0 / x_m)) / x_m;
	}
	return tmp;
}
x_m = abs(x)
function code(x_m)
	tmp = 0.0
	if (x_m <= 0.0055)
		tmp = fma(Float64(-0.041666666666666664 * x_m), x_m, 0.5);
	else
		tmp = Float64(fma(Float64(-1.0 / x_m), cos(x_m), Float64(1.0 / x_m)) / x_m);
	end
	return tmp
end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := If[LessEqual[x$95$m, 0.0055], N[(N[(-0.041666666666666664 * x$95$m), $MachinePrecision] * x$95$m + 0.5), $MachinePrecision], N[(N[(N[(-1.0 / x$95$m), $MachinePrecision] * N[Cos[x$95$m], $MachinePrecision] + N[(1.0 / x$95$m), $MachinePrecision]), $MachinePrecision] / x$95$m), $MachinePrecision]]
\begin{array}{l}
x_m = \left|x\right|

\\
\begin{array}{l}
\mathbf{if}\;x\_m \leq 0.0055:\\
\;\;\;\;\mathsf{fma}\left(-0.041666666666666664 \cdot x\_m, x\_m, 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{\mathsf{fma}\left(\frac{-1}{x\_m}, \cos x\_m, \frac{1}{x\_m}\right)}{x\_m}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 0.0054999999999999997

    1. Initial program 50.5%

      \[\frac{1 - \cos x}{x \cdot x} \]
    2. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\frac{1}{2} + \frac{-1}{24} \cdot {x}^{2}} \]
    3. Step-by-step derivation
      1. lower-+.f64N/A

        \[\leadsto \frac{1}{2} + \color{blue}{\frac{-1}{24} \cdot {x}^{2}} \]
      2. lower-*.f64N/A

        \[\leadsto \frac{1}{2} + \frac{-1}{24} \cdot \color{blue}{{x}^{2}} \]
      3. lower-pow.f6451.1

        \[\leadsto 0.5 + -0.041666666666666664 \cdot {x}^{\color{blue}{2}} \]
    4. Applied rewrites51.1%

      \[\leadsto \color{blue}{0.5 + -0.041666666666666664 \cdot {x}^{2}} \]
    5. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \frac{1}{2} + \color{blue}{\frac{-1}{24} \cdot {x}^{2}} \]
      2. +-commutativeN/A

        \[\leadsto \frac{-1}{24} \cdot {x}^{2} + \color{blue}{\frac{1}{2}} \]
      3. lift-*.f64N/A

        \[\leadsto \frac{-1}{24} \cdot {x}^{2} + \frac{1}{2} \]
      4. lift-pow.f64N/A

        \[\leadsto \frac{-1}{24} \cdot {x}^{2} + \frac{1}{2} \]
      5. pow2N/A

        \[\leadsto \frac{-1}{24} \cdot \left(x \cdot x\right) + \frac{1}{2} \]
      6. associate-*r*N/A

        \[\leadsto \left(\frac{-1}{24} \cdot x\right) \cdot x + \frac{1}{2} \]
      7. lower-fma.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{-1}{24} \cdot x, \color{blue}{x}, \frac{1}{2}\right) \]
      8. lower-*.f6451.1

        \[\leadsto \mathsf{fma}\left(-0.041666666666666664 \cdot x, x, 0.5\right) \]
    6. Applied rewrites51.1%

      \[\leadsto \color{blue}{\mathsf{fma}\left(-0.041666666666666664 \cdot x, x, 0.5\right)} \]

    if 0.0054999999999999997 < x

    1. Initial program 50.5%

      \[\frac{1 - \cos x}{x \cdot x} \]
    2. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \color{blue}{\frac{1 - \cos x}{x \cdot x}} \]
      2. lift-*.f64N/A

        \[\leadsto \frac{1 - \cos x}{\color{blue}{x \cdot x}} \]
      3. associate-/r*N/A

        \[\leadsto \color{blue}{\frac{\frac{1 - \cos x}{x}}{x}} \]
      4. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{\frac{1 - \cos x}{x}}{x}} \]
      5. lower-/.f6451.6

        \[\leadsto \frac{\color{blue}{\frac{1 - \cos x}{x}}}{x} \]
    3. Applied rewrites51.6%

      \[\leadsto \color{blue}{\frac{\frac{1 - \cos x}{x}}{x}} \]
    4. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{1 - \cos x}{x}}}{x} \]
      2. lift--.f64N/A

        \[\leadsto \frac{\frac{\color{blue}{1 - \cos x}}{x}}{x} \]
      3. div-subN/A

        \[\leadsto \frac{\color{blue}{\frac{1}{x} - \frac{\cos x}{x}}}{x} \]
      4. lower--.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{1}{x} - \frac{\cos x}{x}}}{x} \]
      5. lower-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{1}{x}} - \frac{\cos x}{x}}{x} \]
      6. lower-/.f6451.5

        \[\leadsto \frac{\frac{1}{x} - \color{blue}{\frac{\cos x}{x}}}{x} \]
    5. Applied rewrites51.5%

      \[\leadsto \frac{\color{blue}{\frac{1}{x} - \frac{\cos x}{x}}}{x} \]
    6. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \frac{\frac{1}{x} - \color{blue}{\frac{\cos x}{x}}}{x} \]
      2. mult-flipN/A

        \[\leadsto \frac{\frac{1}{x} - \color{blue}{\cos x \cdot \frac{1}{x}}}{x} \]
      3. lift-/.f64N/A

        \[\leadsto \frac{\frac{1}{x} - \cos x \cdot \color{blue}{\frac{1}{x}}}{x} \]
      4. lower-*.f6451.5

        \[\leadsto \frac{\frac{1}{x} - \color{blue}{\cos x \cdot \frac{1}{x}}}{x} \]
    7. Applied rewrites51.5%

      \[\leadsto \frac{\frac{1}{x} - \color{blue}{\cos x \cdot \frac{1}{x}}}{x} \]
    8. Step-by-step derivation
      1. lift--.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{1}{x} - \cos x \cdot \frac{1}{x}}}{x} \]
      2. sub-flipN/A

        \[\leadsto \frac{\color{blue}{\frac{1}{x} + \left(\mathsf{neg}\left(\cos x \cdot \frac{1}{x}\right)\right)}}{x} \]
      3. lift-*.f64N/A

        \[\leadsto \frac{\frac{1}{x} + \left(\mathsf{neg}\left(\color{blue}{\cos x \cdot \frac{1}{x}}\right)\right)}{x} \]
      4. lift-/.f64N/A

        \[\leadsto \frac{\frac{1}{x} + \left(\mathsf{neg}\left(\cos x \cdot \color{blue}{\frac{1}{x}}\right)\right)}{x} \]
      5. mult-flip-revN/A

        \[\leadsto \frac{\frac{1}{x} + \left(\mathsf{neg}\left(\color{blue}{\frac{\cos x}{x}}\right)\right)}{x} \]
      6. distribute-frac-neg2N/A

        \[\leadsto \frac{\frac{1}{x} + \color{blue}{\frac{\cos x}{\mathsf{neg}\left(x\right)}}}{x} \]
      7. lift-neg.f64N/A

        \[\leadsto \frac{\frac{1}{x} + \frac{\cos x}{\color{blue}{-x}}}{x} \]
      8. lift-/.f64N/A

        \[\leadsto \frac{\frac{1}{x} + \color{blue}{\frac{\cos x}{-x}}}{x} \]
      9. +-commutativeN/A

        \[\leadsto \frac{\color{blue}{\frac{\cos x}{-x} + \frac{1}{x}}}{x} \]
      10. lift-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\cos x}{-x}} + \frac{1}{x}}{x} \]
      11. mult-flipN/A

        \[\leadsto \frac{\color{blue}{\cos x \cdot \frac{1}{-x}} + \frac{1}{x}}{x} \]
      12. *-commutativeN/A

        \[\leadsto \frac{\color{blue}{\frac{1}{-x} \cdot \cos x} + \frac{1}{x}}{x} \]
      13. lower-fma.f64N/A

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\frac{1}{-x}, \cos x, \frac{1}{x}\right)}}{x} \]
      14. frac-2negN/A

        \[\leadsto \frac{\mathsf{fma}\left(\color{blue}{\frac{\mathsf{neg}\left(1\right)}{\mathsf{neg}\left(\left(-x\right)\right)}}, \cos x, \frac{1}{x}\right)}{x} \]
      15. metadata-evalN/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\color{blue}{-1}}{\mathsf{neg}\left(\left(-x\right)\right)}, \cos x, \frac{1}{x}\right)}{x} \]
      16. lift-neg.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{-1}{\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right)}, \cos x, \frac{1}{x}\right)}{x} \]
      17. remove-double-negN/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{-1}{\color{blue}{x}}, \cos x, \frac{1}{x}\right)}{x} \]
      18. lower-/.f6451.6

        \[\leadsto \frac{\mathsf{fma}\left(\color{blue}{\frac{-1}{x}}, \cos x, \frac{1}{x}\right)}{x} \]
    9. Applied rewrites51.6%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\frac{-1}{x}, \cos x, \frac{1}{x}\right)}}{x} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 3: 99.6% accurate, 0.9× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 0.0055:\\ \;\;\;\;\mathsf{fma}\left(-0.041666666666666664 \cdot x\_m, x\_m, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{1 - \cos x\_m}{x\_m}}{x\_m}\\ \end{array} \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m)
 :precision binary64
 (if (<= x_m 0.0055)
   (fma (* -0.041666666666666664 x_m) x_m 0.5)
   (/ (/ (- 1.0 (cos x_m)) x_m) x_m)))
x_m = fabs(x);
double code(double x_m) {
	double tmp;
	if (x_m <= 0.0055) {
		tmp = fma((-0.041666666666666664 * x_m), x_m, 0.5);
	} else {
		tmp = ((1.0 - cos(x_m)) / x_m) / x_m;
	}
	return tmp;
}
x_m = abs(x)
function code(x_m)
	tmp = 0.0
	if (x_m <= 0.0055)
		tmp = fma(Float64(-0.041666666666666664 * x_m), x_m, 0.5);
	else
		tmp = Float64(Float64(Float64(1.0 - cos(x_m)) / x_m) / x_m);
	end
	return tmp
end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := If[LessEqual[x$95$m, 0.0055], N[(N[(-0.041666666666666664 * x$95$m), $MachinePrecision] * x$95$m + 0.5), $MachinePrecision], N[(N[(N[(1.0 - N[Cos[x$95$m], $MachinePrecision]), $MachinePrecision] / x$95$m), $MachinePrecision] / x$95$m), $MachinePrecision]]
\begin{array}{l}
x_m = \left|x\right|

\\
\begin{array}{l}
\mathbf{if}\;x\_m \leq 0.0055:\\
\;\;\;\;\mathsf{fma}\left(-0.041666666666666664 \cdot x\_m, x\_m, 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{\frac{1 - \cos x\_m}{x\_m}}{x\_m}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 0.0054999999999999997

    1. Initial program 50.5%

      \[\frac{1 - \cos x}{x \cdot x} \]
    2. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\frac{1}{2} + \frac{-1}{24} \cdot {x}^{2}} \]
    3. Step-by-step derivation
      1. lower-+.f64N/A

        \[\leadsto \frac{1}{2} + \color{blue}{\frac{-1}{24} \cdot {x}^{2}} \]
      2. lower-*.f64N/A

        \[\leadsto \frac{1}{2} + \frac{-1}{24} \cdot \color{blue}{{x}^{2}} \]
      3. lower-pow.f6451.1

        \[\leadsto 0.5 + -0.041666666666666664 \cdot {x}^{\color{blue}{2}} \]
    4. Applied rewrites51.1%

      \[\leadsto \color{blue}{0.5 + -0.041666666666666664 \cdot {x}^{2}} \]
    5. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \frac{1}{2} + \color{blue}{\frac{-1}{24} \cdot {x}^{2}} \]
      2. +-commutativeN/A

        \[\leadsto \frac{-1}{24} \cdot {x}^{2} + \color{blue}{\frac{1}{2}} \]
      3. lift-*.f64N/A

        \[\leadsto \frac{-1}{24} \cdot {x}^{2} + \frac{1}{2} \]
      4. lift-pow.f64N/A

        \[\leadsto \frac{-1}{24} \cdot {x}^{2} + \frac{1}{2} \]
      5. pow2N/A

        \[\leadsto \frac{-1}{24} \cdot \left(x \cdot x\right) + \frac{1}{2} \]
      6. associate-*r*N/A

        \[\leadsto \left(\frac{-1}{24} \cdot x\right) \cdot x + \frac{1}{2} \]
      7. lower-fma.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{-1}{24} \cdot x, \color{blue}{x}, \frac{1}{2}\right) \]
      8. lower-*.f6451.1

        \[\leadsto \mathsf{fma}\left(-0.041666666666666664 \cdot x, x, 0.5\right) \]
    6. Applied rewrites51.1%

      \[\leadsto \color{blue}{\mathsf{fma}\left(-0.041666666666666664 \cdot x, x, 0.5\right)} \]

    if 0.0054999999999999997 < x

    1. Initial program 50.5%

      \[\frac{1 - \cos x}{x \cdot x} \]
    2. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \color{blue}{\frac{1 - \cos x}{x \cdot x}} \]
      2. lift-*.f64N/A

        \[\leadsto \frac{1 - \cos x}{\color{blue}{x \cdot x}} \]
      3. associate-/r*N/A

        \[\leadsto \color{blue}{\frac{\frac{1 - \cos x}{x}}{x}} \]
      4. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{\frac{1 - \cos x}{x}}{x}} \]
      5. lower-/.f6451.6

        \[\leadsto \frac{\color{blue}{\frac{1 - \cos x}{x}}}{x} \]
    3. Applied rewrites51.6%

      \[\leadsto \color{blue}{\frac{\frac{1 - \cos x}{x}}{x}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 4: 99.2% accurate, 0.9× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 0.0055:\\ \;\;\;\;\mathsf{fma}\left(-0.041666666666666664 \cdot x\_m, x\_m, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1 - \cos x\_m}{x\_m \cdot x\_m}\\ \end{array} \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m)
 :precision binary64
 (if (<= x_m 0.0055)
   (fma (* -0.041666666666666664 x_m) x_m 0.5)
   (/ (- 1.0 (cos x_m)) (* x_m x_m))))
x_m = fabs(x);
double code(double x_m) {
	double tmp;
	if (x_m <= 0.0055) {
		tmp = fma((-0.041666666666666664 * x_m), x_m, 0.5);
	} else {
		tmp = (1.0 - cos(x_m)) / (x_m * x_m);
	}
	return tmp;
}
x_m = abs(x)
function code(x_m)
	tmp = 0.0
	if (x_m <= 0.0055)
		tmp = fma(Float64(-0.041666666666666664 * x_m), x_m, 0.5);
	else
		tmp = Float64(Float64(1.0 - cos(x_m)) / Float64(x_m * x_m));
	end
	return tmp
end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := If[LessEqual[x$95$m, 0.0055], N[(N[(-0.041666666666666664 * x$95$m), $MachinePrecision] * x$95$m + 0.5), $MachinePrecision], N[(N[(1.0 - N[Cos[x$95$m], $MachinePrecision]), $MachinePrecision] / N[(x$95$m * x$95$m), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
x_m = \left|x\right|

\\
\begin{array}{l}
\mathbf{if}\;x\_m \leq 0.0055:\\
\;\;\;\;\mathsf{fma}\left(-0.041666666666666664 \cdot x\_m, x\_m, 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{1 - \cos x\_m}{x\_m \cdot x\_m}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 0.0054999999999999997

    1. Initial program 50.5%

      \[\frac{1 - \cos x}{x \cdot x} \]
    2. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\frac{1}{2} + \frac{-1}{24} \cdot {x}^{2}} \]
    3. Step-by-step derivation
      1. lower-+.f64N/A

        \[\leadsto \frac{1}{2} + \color{blue}{\frac{-1}{24} \cdot {x}^{2}} \]
      2. lower-*.f64N/A

        \[\leadsto \frac{1}{2} + \frac{-1}{24} \cdot \color{blue}{{x}^{2}} \]
      3. lower-pow.f6451.1

        \[\leadsto 0.5 + -0.041666666666666664 \cdot {x}^{\color{blue}{2}} \]
    4. Applied rewrites51.1%

      \[\leadsto \color{blue}{0.5 + -0.041666666666666664 \cdot {x}^{2}} \]
    5. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \frac{1}{2} + \color{blue}{\frac{-1}{24} \cdot {x}^{2}} \]
      2. +-commutativeN/A

        \[\leadsto \frac{-1}{24} \cdot {x}^{2} + \color{blue}{\frac{1}{2}} \]
      3. lift-*.f64N/A

        \[\leadsto \frac{-1}{24} \cdot {x}^{2} + \frac{1}{2} \]
      4. lift-pow.f64N/A

        \[\leadsto \frac{-1}{24} \cdot {x}^{2} + \frac{1}{2} \]
      5. pow2N/A

        \[\leadsto \frac{-1}{24} \cdot \left(x \cdot x\right) + \frac{1}{2} \]
      6. associate-*r*N/A

        \[\leadsto \left(\frac{-1}{24} \cdot x\right) \cdot x + \frac{1}{2} \]
      7. lower-fma.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{-1}{24} \cdot x, \color{blue}{x}, \frac{1}{2}\right) \]
      8. lower-*.f6451.1

        \[\leadsto \mathsf{fma}\left(-0.041666666666666664 \cdot x, x, 0.5\right) \]
    6. Applied rewrites51.1%

      \[\leadsto \color{blue}{\mathsf{fma}\left(-0.041666666666666664 \cdot x, x, 0.5\right)} \]

    if 0.0054999999999999997 < x

    1. Initial program 50.5%

      \[\frac{1 - \cos x}{x \cdot x} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 5: 77.4% accurate, 1.9× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 3.5:\\ \;\;\;\;\mathsf{fma}\left(-0.041666666666666664 \cdot x\_m, x\_m, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\mathsf{fma}\left(\frac{1}{x\_m}, -x\_m, 1\right)}{-x\_m}}{x\_m}\\ \end{array} \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m)
 :precision binary64
 (if (<= x_m 3.5)
   (fma (* -0.041666666666666664 x_m) x_m 0.5)
   (/ (/ (fma (/ 1.0 x_m) (- x_m) 1.0) (- x_m)) x_m)))
x_m = fabs(x);
double code(double x_m) {
	double tmp;
	if (x_m <= 3.5) {
		tmp = fma((-0.041666666666666664 * x_m), x_m, 0.5);
	} else {
		tmp = (fma((1.0 / x_m), -x_m, 1.0) / -x_m) / x_m;
	}
	return tmp;
}
x_m = abs(x)
function code(x_m)
	tmp = 0.0
	if (x_m <= 3.5)
		tmp = fma(Float64(-0.041666666666666664 * x_m), x_m, 0.5);
	else
		tmp = Float64(Float64(fma(Float64(1.0 / x_m), Float64(-x_m), 1.0) / Float64(-x_m)) / x_m);
	end
	return tmp
end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := If[LessEqual[x$95$m, 3.5], N[(N[(-0.041666666666666664 * x$95$m), $MachinePrecision] * x$95$m + 0.5), $MachinePrecision], N[(N[(N[(N[(1.0 / x$95$m), $MachinePrecision] * (-x$95$m) + 1.0), $MachinePrecision] / (-x$95$m)), $MachinePrecision] / x$95$m), $MachinePrecision]]
\begin{array}{l}
x_m = \left|x\right|

\\
\begin{array}{l}
\mathbf{if}\;x\_m \leq 3.5:\\
\;\;\;\;\mathsf{fma}\left(-0.041666666666666664 \cdot x\_m, x\_m, 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{\frac{\mathsf{fma}\left(\frac{1}{x\_m}, -x\_m, 1\right)}{-x\_m}}{x\_m}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 3.5

    1. Initial program 50.5%

      \[\frac{1 - \cos x}{x \cdot x} \]
    2. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\frac{1}{2} + \frac{-1}{24} \cdot {x}^{2}} \]
    3. Step-by-step derivation
      1. lower-+.f64N/A

        \[\leadsto \frac{1}{2} + \color{blue}{\frac{-1}{24} \cdot {x}^{2}} \]
      2. lower-*.f64N/A

        \[\leadsto \frac{1}{2} + \frac{-1}{24} \cdot \color{blue}{{x}^{2}} \]
      3. lower-pow.f6451.1

        \[\leadsto 0.5 + -0.041666666666666664 \cdot {x}^{\color{blue}{2}} \]
    4. Applied rewrites51.1%

      \[\leadsto \color{blue}{0.5 + -0.041666666666666664 \cdot {x}^{2}} \]
    5. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \frac{1}{2} + \color{blue}{\frac{-1}{24} \cdot {x}^{2}} \]
      2. +-commutativeN/A

        \[\leadsto \frac{-1}{24} \cdot {x}^{2} + \color{blue}{\frac{1}{2}} \]
      3. lift-*.f64N/A

        \[\leadsto \frac{-1}{24} \cdot {x}^{2} + \frac{1}{2} \]
      4. lift-pow.f64N/A

        \[\leadsto \frac{-1}{24} \cdot {x}^{2} + \frac{1}{2} \]
      5. pow2N/A

        \[\leadsto \frac{-1}{24} \cdot \left(x \cdot x\right) + \frac{1}{2} \]
      6. associate-*r*N/A

        \[\leadsto \left(\frac{-1}{24} \cdot x\right) \cdot x + \frac{1}{2} \]
      7. lower-fma.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{-1}{24} \cdot x, \color{blue}{x}, \frac{1}{2}\right) \]
      8. lower-*.f6451.1

        \[\leadsto \mathsf{fma}\left(-0.041666666666666664 \cdot x, x, 0.5\right) \]
    6. Applied rewrites51.1%

      \[\leadsto \color{blue}{\mathsf{fma}\left(-0.041666666666666664 \cdot x, x, 0.5\right)} \]

    if 3.5 < x

    1. Initial program 50.5%

      \[\frac{1 - \cos x}{x \cdot x} \]
    2. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \color{blue}{\frac{1 - \cos x}{x \cdot x}} \]
      2. lift-*.f64N/A

        \[\leadsto \frac{1 - \cos x}{\color{blue}{x \cdot x}} \]
      3. associate-/r*N/A

        \[\leadsto \color{blue}{\frac{\frac{1 - \cos x}{x}}{x}} \]
      4. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{\frac{1 - \cos x}{x}}{x}} \]
      5. lower-/.f6451.6

        \[\leadsto \frac{\color{blue}{\frac{1 - \cos x}{x}}}{x} \]
    3. Applied rewrites51.6%

      \[\leadsto \color{blue}{\frac{\frac{1 - \cos x}{x}}{x}} \]
    4. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{1 - \cos x}{x}}}{x} \]
      2. lift--.f64N/A

        \[\leadsto \frac{\frac{\color{blue}{1 - \cos x}}{x}}{x} \]
      3. div-subN/A

        \[\leadsto \frac{\color{blue}{\frac{1}{x} - \frac{\cos x}{x}}}{x} \]
      4. lower--.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{1}{x} - \frac{\cos x}{x}}}{x} \]
      5. lower-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{1}{x}} - \frac{\cos x}{x}}{x} \]
      6. lower-/.f6451.5

        \[\leadsto \frac{\frac{1}{x} - \color{blue}{\frac{\cos x}{x}}}{x} \]
    5. Applied rewrites51.5%

      \[\leadsto \frac{\color{blue}{\frac{1}{x} - \frac{\cos x}{x}}}{x} \]
    6. Applied rewrites51.2%

      \[\leadsto \frac{\color{blue}{\frac{\mathsf{fma}\left(\frac{1}{x}, -x, \cos x\right)}{-x}}}{x} \]
    7. Taylor expanded in x around 0

      \[\leadsto \frac{\frac{\mathsf{fma}\left(\frac{1}{x}, -x, \color{blue}{1}\right)}{-x}}{x} \]
    8. Step-by-step derivation
      1. Applied rewrites28.4%

        \[\leadsto \frac{\frac{\mathsf{fma}\left(\frac{1}{x}, -x, \color{blue}{1}\right)}{-x}}{x} \]
    9. Recombined 2 regimes into one program.
    10. Add Preprocessing

    Alternative 6: 77.1% accurate, 3.0× speedup?

    \[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 1.22 \cdot 10^{+77}:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{1 - 1}{x\_m \cdot x\_m}\\ \end{array} \end{array} \]
    x_m = (fabs.f64 x)
    (FPCore (x_m)
     :precision binary64
     (if (<= x_m 1.22e+77) 0.5 (/ (- 1.0 1.0) (* x_m x_m))))
    x_m = fabs(x);
    double code(double x_m) {
    	double tmp;
    	if (x_m <= 1.22e+77) {
    		tmp = 0.5;
    	} else {
    		tmp = (1.0 - 1.0) / (x_m * x_m);
    	}
    	return tmp;
    }
    
    x_m =     private
    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(x_m)
    use fmin_fmax_functions
        real(8), intent (in) :: x_m
        real(8) :: tmp
        if (x_m <= 1.22d+77) then
            tmp = 0.5d0
        else
            tmp = (1.0d0 - 1.0d0) / (x_m * x_m)
        end if
        code = tmp
    end function
    
    x_m = Math.abs(x);
    public static double code(double x_m) {
    	double tmp;
    	if (x_m <= 1.22e+77) {
    		tmp = 0.5;
    	} else {
    		tmp = (1.0 - 1.0) / (x_m * x_m);
    	}
    	return tmp;
    }
    
    x_m = math.fabs(x)
    def code(x_m):
    	tmp = 0
    	if x_m <= 1.22e+77:
    		tmp = 0.5
    	else:
    		tmp = (1.0 - 1.0) / (x_m * x_m)
    	return tmp
    
    x_m = abs(x)
    function code(x_m)
    	tmp = 0.0
    	if (x_m <= 1.22e+77)
    		tmp = 0.5;
    	else
    		tmp = Float64(Float64(1.0 - 1.0) / Float64(x_m * x_m));
    	end
    	return tmp
    end
    
    x_m = abs(x);
    function tmp_2 = code(x_m)
    	tmp = 0.0;
    	if (x_m <= 1.22e+77)
    		tmp = 0.5;
    	else
    		tmp = (1.0 - 1.0) / (x_m * x_m);
    	end
    	tmp_2 = tmp;
    end
    
    x_m = N[Abs[x], $MachinePrecision]
    code[x$95$m_] := If[LessEqual[x$95$m, 1.22e+77], 0.5, N[(N[(1.0 - 1.0), $MachinePrecision] / N[(x$95$m * x$95$m), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    x_m = \left|x\right|
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x\_m \leq 1.22 \cdot 10^{+77}:\\
    \;\;\;\;0.5\\
    
    \mathbf{else}:\\
    \;\;\;\;\frac{1 - 1}{x\_m \cdot x\_m}\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if x < 1.22000000000000012e77

      1. Initial program 50.5%

        \[\frac{1 - \cos x}{x \cdot x} \]
      2. Taylor expanded in x around 0

        \[\leadsto \color{blue}{\frac{1}{2}} \]
      3. Step-by-step derivation
        1. Applied rewrites52.1%

          \[\leadsto \color{blue}{0.5} \]

        if 1.22000000000000012e77 < x

        1. Initial program 50.5%

          \[\frac{1 - \cos x}{x \cdot x} \]
        2. Taylor expanded in x around 0

          \[\leadsto \frac{1 - \color{blue}{1}}{x \cdot x} \]
        3. Step-by-step derivation
          1. Applied rewrites27.6%

            \[\leadsto \frac{1 - \color{blue}{1}}{x \cdot x} \]
        4. Recombined 2 regimes into one program.
        5. Add Preprocessing

        Alternative 7: 52.1% accurate, 41.8× speedup?

        \[\begin{array}{l} x_m = \left|x\right| \\ 0.5 \end{array} \]
        x_m = (fabs.f64 x)
        (FPCore (x_m) :precision binary64 0.5)
        x_m = fabs(x);
        double code(double x_m) {
        	return 0.5;
        }
        
        x_m =     private
        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(x_m)
        use fmin_fmax_functions
            real(8), intent (in) :: x_m
            code = 0.5d0
        end function
        
        x_m = Math.abs(x);
        public static double code(double x_m) {
        	return 0.5;
        }
        
        x_m = math.fabs(x)
        def code(x_m):
        	return 0.5
        
        x_m = abs(x)
        function code(x_m)
        	return 0.5
        end
        
        x_m = abs(x);
        function tmp = code(x_m)
        	tmp = 0.5;
        end
        
        x_m = N[Abs[x], $MachinePrecision]
        code[x$95$m_] := 0.5
        
        \begin{array}{l}
        x_m = \left|x\right|
        
        \\
        0.5
        \end{array}
        
        Derivation
        1. Initial program 50.5%

          \[\frac{1 - \cos x}{x \cdot x} \]
        2. Taylor expanded in x around 0

          \[\leadsto \color{blue}{\frac{1}{2}} \]
        3. Step-by-step derivation
          1. Applied rewrites52.1%

            \[\leadsto \color{blue}{0.5} \]
          2. Add Preprocessing

          Reproduce

          ?
          herbie shell --seed 2025142 
          (FPCore (x)
            :name "cos2 (problem 3.4.1)"
            :precision binary64
            (/ (- 1.0 (cos x)) (* x x)))