cos2 (problem 3.4.1)

Percentage Accurate: 50.7% → 99.8%
Time: 10.7s
Alternatives: 12
Speedup: 120.0×

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);
}
real(8) function code(x)
    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}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 12 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: 50.7% 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);
}
real(8) function code(x)
    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: 99.8% accurate, 0.5× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 4 \cdot 10^{-7}:\\ \;\;\;\;\mathsf{fma}\left(-0.041666666666666664, x\_m \cdot x\_m, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\sin x\_m \cdot \tan \left(x\_m \cdot 0.5\right)}{x\_m}}{x\_m}\\ \end{array} \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m)
 :precision binary64
 (if (<= x_m 4e-7)
   (fma -0.041666666666666664 (* x_m x_m) 0.5)
   (/ (/ (* (sin x_m) (tan (* x_m 0.5))) x_m) x_m)))
x_m = fabs(x);
double code(double x_m) {
	double tmp;
	if (x_m <= 4e-7) {
		tmp = fma(-0.041666666666666664, (x_m * x_m), 0.5);
	} else {
		tmp = ((sin(x_m) * tan((x_m * 0.5))) / x_m) / x_m;
	}
	return tmp;
}
x_m = abs(x)
function code(x_m)
	tmp = 0.0
	if (x_m <= 4e-7)
		tmp = fma(-0.041666666666666664, Float64(x_m * x_m), 0.5);
	else
		tmp = Float64(Float64(Float64(sin(x_m) * tan(Float64(x_m * 0.5))) / x_m) / x_m);
	end
	return tmp
end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := If[LessEqual[x$95$m, 4e-7], N[(-0.041666666666666664 * N[(x$95$m * x$95$m), $MachinePrecision] + 0.5), $MachinePrecision], N[(N[(N[(N[Sin[x$95$m], $MachinePrecision] * N[Tan[N[(x$95$m * 0.5), $MachinePrecision]], $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 4 \cdot 10^{-7}:\\
\;\;\;\;\mathsf{fma}\left(-0.041666666666666664, x\_m \cdot x\_m, 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{\frac{\sin x\_m \cdot \tan \left(x\_m \cdot 0.5\right)}{x\_m}}{x\_m}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 3.9999999999999998e-7

    1. Initial program 30.3%

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

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

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

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{-1}{24}, {x}^{2}, \frac{1}{2}\right)} \]
      3. unpow2N/A

        \[\leadsto \mathsf{fma}\left(\frac{-1}{24}, \color{blue}{x \cdot x}, \frac{1}{2}\right) \]
      4. lower-*.f6471.4

        \[\leadsto \mathsf{fma}\left(-0.041666666666666664, \color{blue}{x \cdot x}, 0.5\right) \]
    5. Applied rewrites71.4%

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

    if 3.9999999999999998e-7 < x

    1. Initial program 98.3%

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

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

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

        \[\leadsto \frac{\color{blue}{\frac{1 \cdot 1 - \cos x \cdot \cos x}{1 + \cos x}}}{x \cdot x} \]
      4. associate-/l/N/A

        \[\leadsto \color{blue}{\frac{1 \cdot 1 - \cos x \cdot \cos x}{\left(x \cdot x\right) \cdot \left(1 + \cos x\right)}} \]
      5. metadata-evalN/A

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

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

        \[\leadsto \frac{1 - \cos x \cdot \color{blue}{\cos x}}{\left(x \cdot x\right) \cdot \left(1 + \cos x\right)} \]
      8. 1-sub-cosN/A

        \[\leadsto \frac{\color{blue}{\sin x \cdot \sin x}}{\left(x \cdot x\right) \cdot \left(1 + \cos x\right)} \]
      9. times-fracN/A

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

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

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

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

        \[\leadsto \frac{\sin x}{x \cdot x} \cdot \frac{\sin x}{1 + \color{blue}{\cos x}} \]
      14. hang-0p-tanN/A

        \[\leadsto \frac{\sin x}{x \cdot x} \cdot \color{blue}{\tan \left(\frac{x}{2}\right)} \]
      15. lower-tan.f64N/A

        \[\leadsto \frac{\sin x}{x \cdot x} \cdot \color{blue}{\tan \left(\frac{x}{2}\right)} \]
      16. lower-/.f6499.6

        \[\leadsto \frac{\sin x}{x \cdot x} \cdot \tan \color{blue}{\left(\frac{x}{2}\right)} \]
    4. Applied rewrites99.6%

      \[\leadsto \color{blue}{\frac{\sin x}{x \cdot x} \cdot \tan \left(\frac{x}{2}\right)} \]
    5. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \color{blue}{\frac{\sin x}{x \cdot x} \cdot \tan \left(\frac{x}{2}\right)} \]
      2. lift-/.f64N/A

        \[\leadsto \color{blue}{\frac{\sin x}{x \cdot x}} \cdot \tan \left(\frac{x}{2}\right) \]
      3. associate-*l/N/A

        \[\leadsto \color{blue}{\frac{\sin x \cdot \tan \left(\frac{x}{2}\right)}{x \cdot x}} \]
      4. lift-*.f64N/A

        \[\leadsto \frac{\sin x \cdot \tan \left(\frac{x}{2}\right)}{\color{blue}{x \cdot x}} \]
      5. associate-/r*N/A

        \[\leadsto \color{blue}{\frac{\frac{\sin x \cdot \tan \left(\frac{x}{2}\right)}{x}}{x}} \]
      6. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{\frac{\sin x \cdot \tan \left(\frac{x}{2}\right)}{x}}{x}} \]
      7. lower-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\sin x \cdot \tan \left(\frac{x}{2}\right)}{x}}}{x} \]
      8. lower-*.f6499.7

        \[\leadsto \frac{\frac{\color{blue}{\sin x \cdot \tan \left(\frac{x}{2}\right)}}{x}}{x} \]
      9. lift-/.f64N/A

        \[\leadsto \frac{\frac{\sin x \cdot \tan \color{blue}{\left(\frac{x}{2}\right)}}{x}}{x} \]
      10. div-invN/A

        \[\leadsto \frac{\frac{\sin x \cdot \tan \color{blue}{\left(x \cdot \frac{1}{2}\right)}}{x}}{x} \]
      11. metadata-evalN/A

        \[\leadsto \frac{\frac{\sin x \cdot \tan \left(x \cdot \color{blue}{\frac{1}{2}}\right)}{x}}{x} \]
      12. lower-*.f6499.7

        \[\leadsto \frac{\frac{\sin x \cdot \tan \color{blue}{\left(x \cdot 0.5\right)}}{x}}{x} \]
    6. Applied rewrites99.7%

      \[\leadsto \color{blue}{\frac{\frac{\sin x \cdot \tan \left(x \cdot 0.5\right)}{x}}{x}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 2: 99.1% accurate, 0.5× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \sin x\_m \cdot \frac{1}{x\_m \cdot \frac{x\_m}{\tan \left(x\_m \cdot 0.5\right)}} \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m)
 :precision binary64
 (* (sin x_m) (/ 1.0 (* x_m (/ x_m (tan (* x_m 0.5)))))))
x_m = fabs(x);
double code(double x_m) {
	return sin(x_m) * (1.0 / (x_m * (x_m / tan((x_m * 0.5)))));
}
x_m = abs(x)
real(8) function code(x_m)
    real(8), intent (in) :: x_m
    code = sin(x_m) * (1.0d0 / (x_m * (x_m / tan((x_m * 0.5d0)))))
end function
x_m = Math.abs(x);
public static double code(double x_m) {
	return Math.sin(x_m) * (1.0 / (x_m * (x_m / Math.tan((x_m * 0.5)))));
}
x_m = math.fabs(x)
def code(x_m):
	return math.sin(x_m) * (1.0 / (x_m * (x_m / math.tan((x_m * 0.5)))))
x_m = abs(x)
function code(x_m)
	return Float64(sin(x_m) * Float64(1.0 / Float64(x_m * Float64(x_m / tan(Float64(x_m * 0.5))))))
end
x_m = abs(x);
function tmp = code(x_m)
	tmp = sin(x_m) * (1.0 / (x_m * (x_m / tan((x_m * 0.5)))));
end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := N[(N[Sin[x$95$m], $MachinePrecision] * N[(1.0 / N[(x$95$m * N[(x$95$m / N[Tan[N[(x$95$m * 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|

\\
\sin x\_m \cdot \frac{1}{x\_m \cdot \frac{x\_m}{\tan \left(x\_m \cdot 0.5\right)}}
\end{array}
Derivation
  1. Initial program 48.4%

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

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

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

      \[\leadsto \frac{\color{blue}{\frac{1 \cdot 1 - \cos x \cdot \cos x}{1 + \cos x}}}{x \cdot x} \]
    4. associate-/l/N/A

      \[\leadsto \color{blue}{\frac{1 \cdot 1 - \cos x \cdot \cos x}{\left(x \cdot x\right) \cdot \left(1 + \cos x\right)}} \]
    5. metadata-evalN/A

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

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

      \[\leadsto \frac{1 - \cos x \cdot \color{blue}{\cos x}}{\left(x \cdot x\right) \cdot \left(1 + \cos x\right)} \]
    8. 1-sub-cosN/A

      \[\leadsto \frac{\color{blue}{\sin x \cdot \sin x}}{\left(x \cdot x\right) \cdot \left(1 + \cos x\right)} \]
    9. times-fracN/A

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

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

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

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

      \[\leadsto \frac{\sin x}{x \cdot x} \cdot \frac{\sin x}{1 + \color{blue}{\cos x}} \]
    14. hang-0p-tanN/A

      \[\leadsto \frac{\sin x}{x \cdot x} \cdot \color{blue}{\tan \left(\frac{x}{2}\right)} \]
    15. lower-tan.f64N/A

      \[\leadsto \frac{\sin x}{x \cdot x} \cdot \color{blue}{\tan \left(\frac{x}{2}\right)} \]
    16. lower-/.f6471.9

      \[\leadsto \frac{\sin x}{x \cdot x} \cdot \tan \color{blue}{\left(\frac{x}{2}\right)} \]
  4. Applied rewrites71.9%

    \[\leadsto \color{blue}{\frac{\sin x}{x \cdot x} \cdot \tan \left(\frac{x}{2}\right)} \]
  5. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \color{blue}{\frac{\sin x}{x \cdot x} \cdot \tan \left(\frac{x}{2}\right)} \]
    2. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{\sin x}{x \cdot x}} \cdot \tan \left(\frac{x}{2}\right) \]
    3. associate-*l/N/A

      \[\leadsto \color{blue}{\frac{\sin x \cdot \tan \left(\frac{x}{2}\right)}{x \cdot x}} \]
    4. associate-/l*N/A

      \[\leadsto \color{blue}{\sin x \cdot \frac{\tan \left(\frac{x}{2}\right)}{x \cdot x}} \]
    5. lower-*.f64N/A

      \[\leadsto \color{blue}{\sin x \cdot \frac{\tan \left(\frac{x}{2}\right)}{x \cdot x}} \]
    6. lower-/.f6471.9

      \[\leadsto \sin x \cdot \color{blue}{\frac{\tan \left(\frac{x}{2}\right)}{x \cdot x}} \]
    7. lift-/.f64N/A

      \[\leadsto \sin x \cdot \frac{\tan \color{blue}{\left(\frac{x}{2}\right)}}{x \cdot x} \]
    8. div-invN/A

      \[\leadsto \sin x \cdot \frac{\tan \color{blue}{\left(x \cdot \frac{1}{2}\right)}}{x \cdot x} \]
    9. metadata-evalN/A

      \[\leadsto \sin x \cdot \frac{\tan \left(x \cdot \color{blue}{\frac{1}{2}}\right)}{x \cdot x} \]
    10. lower-*.f6471.9

      \[\leadsto \sin x \cdot \frac{\tan \color{blue}{\left(x \cdot 0.5\right)}}{x \cdot x} \]
  6. Applied rewrites71.9%

    \[\leadsto \color{blue}{\sin x \cdot \frac{\tan \left(x \cdot 0.5\right)}{x \cdot x}} \]
  7. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \sin x \cdot \color{blue}{\frac{\tan \left(x \cdot \frac{1}{2}\right)}{x \cdot x}} \]
    2. clear-numN/A

      \[\leadsto \sin x \cdot \color{blue}{\frac{1}{\frac{x \cdot x}{\tan \left(x \cdot \frac{1}{2}\right)}}} \]
    3. lower-/.f64N/A

      \[\leadsto \sin x \cdot \color{blue}{\frac{1}{\frac{x \cdot x}{\tan \left(x \cdot \frac{1}{2}\right)}}} \]
    4. lower-/.f6471.9

      \[\leadsto \sin x \cdot \frac{1}{\color{blue}{\frac{x \cdot x}{\tan \left(x \cdot 0.5\right)}}} \]
  8. Applied rewrites71.9%

    \[\leadsto \sin x \cdot \color{blue}{\frac{1}{\frac{x \cdot x}{\tan \left(x \cdot 0.5\right)}}} \]
  9. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \sin x \cdot \frac{1}{\color{blue}{\frac{x \cdot x}{\tan \left(x \cdot \frac{1}{2}\right)}}} \]
    2. lift-*.f64N/A

      \[\leadsto \sin x \cdot \frac{1}{\frac{\color{blue}{x \cdot x}}{\tan \left(x \cdot \frac{1}{2}\right)}} \]
    3. associate-/l*N/A

      \[\leadsto \sin x \cdot \frac{1}{\color{blue}{x \cdot \frac{x}{\tan \left(x \cdot \frac{1}{2}\right)}}} \]
    4. *-commutativeN/A

      \[\leadsto \sin x \cdot \frac{1}{\color{blue}{\frac{x}{\tan \left(x \cdot \frac{1}{2}\right)} \cdot x}} \]
    5. lower-*.f64N/A

      \[\leadsto \sin x \cdot \frac{1}{\color{blue}{\frac{x}{\tan \left(x \cdot \frac{1}{2}\right)} \cdot x}} \]
    6. lower-/.f6499.7

      \[\leadsto \sin x \cdot \frac{1}{\color{blue}{\frac{x}{\tan \left(x \cdot 0.5\right)}} \cdot x} \]
  10. Applied rewrites99.7%

    \[\leadsto \sin x \cdot \frac{1}{\color{blue}{\frac{x}{\tan \left(x \cdot 0.5\right)} \cdot x}} \]
  11. Final simplification99.7%

    \[\leadsto \sin x \cdot \frac{1}{x \cdot \frac{x}{\tan \left(x \cdot 0.5\right)}} \]
  12. Add Preprocessing

Alternative 3: 99.2% accurate, 0.5× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 2 \cdot 10^{-6}:\\ \;\;\;\;\mathsf{fma}\left(-0.041666666666666664, x\_m \cdot x\_m, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\sin x\_m \cdot \frac{\tan \left(x\_m \cdot 0.5\right)}{x\_m \cdot x\_m}\\ \end{array} \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m)
 :precision binary64
 (if (<= x_m 2e-6)
   (fma -0.041666666666666664 (* x_m x_m) 0.5)
   (* (sin x_m) (/ (tan (* x_m 0.5)) (* x_m x_m)))))
x_m = fabs(x);
double code(double x_m) {
	double tmp;
	if (x_m <= 2e-6) {
		tmp = fma(-0.041666666666666664, (x_m * x_m), 0.5);
	} else {
		tmp = sin(x_m) * (tan((x_m * 0.5)) / (x_m * x_m));
	}
	return tmp;
}
x_m = abs(x)
function code(x_m)
	tmp = 0.0
	if (x_m <= 2e-6)
		tmp = fma(-0.041666666666666664, Float64(x_m * x_m), 0.5);
	else
		tmp = Float64(sin(x_m) * Float64(tan(Float64(x_m * 0.5)) / Float64(x_m * x_m)));
	end
	return tmp
end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := If[LessEqual[x$95$m, 2e-6], N[(-0.041666666666666664 * N[(x$95$m * x$95$m), $MachinePrecision] + 0.5), $MachinePrecision], N[(N[Sin[x$95$m], $MachinePrecision] * N[(N[Tan[N[(x$95$m * 0.5), $MachinePrecision]], $MachinePrecision] / N[(x$95$m * x$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
x_m = \left|x\right|

\\
\begin{array}{l}
\mathbf{if}\;x\_m \leq 2 \cdot 10^{-6}:\\
\;\;\;\;\mathsf{fma}\left(-0.041666666666666664, x\_m \cdot x\_m, 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;\sin x\_m \cdot \frac{\tan \left(x\_m \cdot 0.5\right)}{x\_m \cdot x\_m}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.99999999999999991e-6

    1. Initial program 30.4%

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

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

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

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{-1}{24}, {x}^{2}, \frac{1}{2}\right)} \]
      3. unpow2N/A

        \[\leadsto \mathsf{fma}\left(\frac{-1}{24}, \color{blue}{x \cdot x}, \frac{1}{2}\right) \]
      4. lower-*.f6471.5

        \[\leadsto \mathsf{fma}\left(-0.041666666666666664, \color{blue}{x \cdot x}, 0.5\right) \]
    5. Applied rewrites71.5%

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

    if 1.99999999999999991e-6 < x

    1. Initial program 99.1%

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

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

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

        \[\leadsto \frac{\color{blue}{\frac{1 \cdot 1 - \cos x \cdot \cos x}{1 + \cos x}}}{x \cdot x} \]
      4. associate-/l/N/A

        \[\leadsto \color{blue}{\frac{1 \cdot 1 - \cos x \cdot \cos x}{\left(x \cdot x\right) \cdot \left(1 + \cos x\right)}} \]
      5. metadata-evalN/A

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

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

        \[\leadsto \frac{1 - \cos x \cdot \color{blue}{\cos x}}{\left(x \cdot x\right) \cdot \left(1 + \cos x\right)} \]
      8. 1-sub-cosN/A

        \[\leadsto \frac{\color{blue}{\sin x \cdot \sin x}}{\left(x \cdot x\right) \cdot \left(1 + \cos x\right)} \]
      9. times-fracN/A

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

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

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

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

        \[\leadsto \frac{\sin x}{x \cdot x} \cdot \frac{\sin x}{1 + \color{blue}{\cos x}} \]
      14. hang-0p-tanN/A

        \[\leadsto \frac{\sin x}{x \cdot x} \cdot \color{blue}{\tan \left(\frac{x}{2}\right)} \]
      15. lower-tan.f64N/A

        \[\leadsto \frac{\sin x}{x \cdot x} \cdot \color{blue}{\tan \left(\frac{x}{2}\right)} \]
      16. lower-/.f6499.6

        \[\leadsto \frac{\sin x}{x \cdot x} \cdot \tan \color{blue}{\left(\frac{x}{2}\right)} \]
    4. Applied rewrites99.6%

      \[\leadsto \color{blue}{\frac{\sin x}{x \cdot x} \cdot \tan \left(\frac{x}{2}\right)} \]
    5. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \color{blue}{\frac{\sin x}{x \cdot x} \cdot \tan \left(\frac{x}{2}\right)} \]
      2. lift-/.f64N/A

        \[\leadsto \color{blue}{\frac{\sin x}{x \cdot x}} \cdot \tan \left(\frac{x}{2}\right) \]
      3. associate-*l/N/A

        \[\leadsto \color{blue}{\frac{\sin x \cdot \tan \left(\frac{x}{2}\right)}{x \cdot x}} \]
      4. associate-/l*N/A

        \[\leadsto \color{blue}{\sin x \cdot \frac{\tan \left(\frac{x}{2}\right)}{x \cdot x}} \]
      5. lower-*.f64N/A

        \[\leadsto \color{blue}{\sin x \cdot \frac{\tan \left(\frac{x}{2}\right)}{x \cdot x}} \]
      6. lower-/.f6499.7

        \[\leadsto \sin x \cdot \color{blue}{\frac{\tan \left(\frac{x}{2}\right)}{x \cdot x}} \]
      7. lift-/.f64N/A

        \[\leadsto \sin x \cdot \frac{\tan \color{blue}{\left(\frac{x}{2}\right)}}{x \cdot x} \]
      8. div-invN/A

        \[\leadsto \sin x \cdot \frac{\tan \color{blue}{\left(x \cdot \frac{1}{2}\right)}}{x \cdot x} \]
      9. metadata-evalN/A

        \[\leadsto \sin x \cdot \frac{\tan \left(x \cdot \color{blue}{\frac{1}{2}}\right)}{x \cdot x} \]
      10. lower-*.f6499.7

        \[\leadsto \sin x \cdot \frac{\tan \color{blue}{\left(x \cdot 0.5\right)}}{x \cdot x} \]
    6. Applied rewrites99.7%

      \[\leadsto \color{blue}{\sin x \cdot \frac{\tan \left(x \cdot 0.5\right)}{x \cdot x}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 4: 99.6% accurate, 0.8× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 0.0052:\\ \;\;\;\;\mathsf{fma}\left(-0.041666666666666664, x\_m \cdot x\_m, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{1}{x\_m}}{\frac{x\_m}{1 - \cos x\_m}}\\ \end{array} \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m)
 :precision binary64
 (if (<= x_m 0.0052)
   (fma -0.041666666666666664 (* x_m x_m) 0.5)
   (/ (/ 1.0 x_m) (/ x_m (- 1.0 (cos x_m))))))
x_m = fabs(x);
double code(double x_m) {
	double tmp;
	if (x_m <= 0.0052) {
		tmp = fma(-0.041666666666666664, (x_m * x_m), 0.5);
	} else {
		tmp = (1.0 / x_m) / (x_m / (1.0 - cos(x_m)));
	}
	return tmp;
}
x_m = abs(x)
function code(x_m)
	tmp = 0.0
	if (x_m <= 0.0052)
		tmp = fma(-0.041666666666666664, Float64(x_m * x_m), 0.5);
	else
		tmp = Float64(Float64(1.0 / x_m) / Float64(x_m / Float64(1.0 - cos(x_m))));
	end
	return tmp
end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := If[LessEqual[x$95$m, 0.0052], N[(-0.041666666666666664 * N[(x$95$m * x$95$m), $MachinePrecision] + 0.5), $MachinePrecision], N[(N[(1.0 / x$95$m), $MachinePrecision] / N[(x$95$m / N[(1.0 - N[Cos[x$95$m], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
x_m = \left|x\right|

\\
\begin{array}{l}
\mathbf{if}\;x\_m \leq 0.0052:\\
\;\;\;\;\mathsf{fma}\left(-0.041666666666666664, x\_m \cdot x\_m, 0.5\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 0.0051999999999999998

    1. Initial program 30.4%

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

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

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

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{-1}{24}, {x}^{2}, \frac{1}{2}\right)} \]
      3. unpow2N/A

        \[\leadsto \mathsf{fma}\left(\frac{-1}{24}, \color{blue}{x \cdot x}, \frac{1}{2}\right) \]
      4. lower-*.f6471.5

        \[\leadsto \mathsf{fma}\left(-0.041666666666666664, \color{blue}{x \cdot x}, 0.5\right) \]
    5. Applied rewrites71.5%

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

    if 0.0051999999999999998 < x

    1. Initial program 99.1%

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

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

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

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

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

        \[\leadsto \color{blue}{\frac{1}{x \cdot x}} - \frac{\cos x}{x \cdot x} \]
      6. lower-/.f6499.1

        \[\leadsto \frac{1}{x \cdot x} - \color{blue}{\frac{\cos x}{x \cdot x}} \]
    4. Applied rewrites99.1%

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\frac{1 - \color{blue}{\cos x}}{x}}{x} \]
      11. lower--.f6499.2

        \[\leadsto \frac{\frac{\color{blue}{1 - \cos x}}{x}}{x} \]
    6. Applied rewrites99.2%

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

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

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

        \[\leadsto \color{blue}{\frac{1 - \cos x}{x}} \cdot \frac{1}{x} \]
      4. clear-numN/A

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

        \[\leadsto \color{blue}{\frac{1 \cdot \frac{1}{x}}{\frac{x}{1 - \cos x}}} \]
      6. div-invN/A

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

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

        \[\leadsto \frac{\color{blue}{\frac{1}{x}}}{\frac{x}{1 - \cos x}} \]
      9. lower-/.f6499.2

        \[\leadsto \frac{\frac{1}{x}}{\color{blue}{\frac{x}{1 - \cos x}}} \]
    8. Applied rewrites99.2%

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

Alternative 5: 99.6% accurate, 0.9× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 0.0052:\\ \;\;\;\;\mathsf{fma}\left(-0.041666666666666664, x\_m \cdot x\_m, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{1 - \cos x\_m}{x\_m}}{x\_m}\\ \end{array} \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m)
 :precision binary64
 (if (<= x_m 0.0052)
   (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 <= 0.0052) {
		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 <= 0.0052)
		tmp = fma(-0.041666666666666664, Float64(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, 0.0052], N[(-0.041666666666666664 * N[(x$95$m * x$95$m), $MachinePrecision] + 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 0.0052:\\
\;\;\;\;\mathsf{fma}\left(-0.041666666666666664, x\_m \cdot 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 < 0.0051999999999999998

    1. Initial program 30.4%

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

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

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

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{-1}{24}, {x}^{2}, \frac{1}{2}\right)} \]
      3. unpow2N/A

        \[\leadsto \mathsf{fma}\left(\frac{-1}{24}, \color{blue}{x \cdot x}, \frac{1}{2}\right) \]
      4. lower-*.f6471.5

        \[\leadsto \mathsf{fma}\left(-0.041666666666666664, \color{blue}{x \cdot x}, 0.5\right) \]
    5. Applied rewrites71.5%

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

    if 0.0051999999999999998 < x

    1. Initial program 99.1%

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

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

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

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

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

        \[\leadsto \color{blue}{\frac{1}{x \cdot x}} - \frac{\cos x}{x \cdot x} \]
      6. lower-/.f6499.1

        \[\leadsto \frac{1}{x \cdot x} - \color{blue}{\frac{\cos x}{x \cdot x}} \]
    4. Applied rewrites99.1%

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\frac{1 - \color{blue}{\cos x}}{x}}{x} \]
      11. lower--.f6499.2

        \[\leadsto \frac{\frac{\color{blue}{1 - \cos x}}{x}}{x} \]
    6. Applied rewrites99.2%

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

Alternative 6: 99.0% accurate, 0.9× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 0.0052:\\ \;\;\;\;\mathsf{fma}\left(-0.041666666666666664, x\_m \cdot x\_m, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{-1}{x\_m \cdot x\_m} \cdot \left(\cos x\_m + -1\right)\\ \end{array} \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m)
 :precision binary64
 (if (<= x_m 0.0052)
   (fma -0.041666666666666664 (* x_m x_m) 0.5)
   (* (/ -1.0 (* x_m x_m)) (+ (cos x_m) -1.0))))
x_m = fabs(x);
double code(double x_m) {
	double tmp;
	if (x_m <= 0.0052) {
		tmp = fma(-0.041666666666666664, (x_m * x_m), 0.5);
	} else {
		tmp = (-1.0 / (x_m * x_m)) * (cos(x_m) + -1.0);
	}
	return tmp;
}
x_m = abs(x)
function code(x_m)
	tmp = 0.0
	if (x_m <= 0.0052)
		tmp = fma(-0.041666666666666664, Float64(x_m * x_m), 0.5);
	else
		tmp = Float64(Float64(-1.0 / Float64(x_m * x_m)) * Float64(cos(x_m) + -1.0));
	end
	return tmp
end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := If[LessEqual[x$95$m, 0.0052], N[(-0.041666666666666664 * N[(x$95$m * x$95$m), $MachinePrecision] + 0.5), $MachinePrecision], N[(N[(-1.0 / N[(x$95$m * x$95$m), $MachinePrecision]), $MachinePrecision] * N[(N[Cos[x$95$m], $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
x_m = \left|x\right|

\\
\begin{array}{l}
\mathbf{if}\;x\_m \leq 0.0052:\\
\;\;\;\;\mathsf{fma}\left(-0.041666666666666664, x\_m \cdot x\_m, 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{-1}{x\_m \cdot x\_m} \cdot \left(\cos x\_m + -1\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 0.0051999999999999998

    1. Initial program 30.4%

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

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

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

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{-1}{24}, {x}^{2}, \frac{1}{2}\right)} \]
      3. unpow2N/A

        \[\leadsto \mathsf{fma}\left(\frac{-1}{24}, \color{blue}{x \cdot x}, \frac{1}{2}\right) \]
      4. lower-*.f6471.5

        \[\leadsto \mathsf{fma}\left(-0.041666666666666664, \color{blue}{x \cdot x}, 0.5\right) \]
    5. Applied rewrites71.5%

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

    if 0.0051999999999999998 < x

    1. Initial program 99.1%

      \[\frac{1 - \cos x}{x \cdot x} \]
    2. Add Preprocessing
    3. Applied rewrites99.2%

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

Alternative 7: 99.0% accurate, 1.0× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 0.0052:\\ \;\;\;\;\mathsf{fma}\left(-0.041666666666666664, x\_m \cdot x\_m, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1 - \cos x\_m}{x\_m \cdot x\_m}\\ \end{array} \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m)
 :precision binary64
 (if (<= x_m 0.0052)
   (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 <= 0.0052) {
		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 <= 0.0052)
		tmp = fma(-0.041666666666666664, Float64(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, 0.0052], N[(-0.041666666666666664 * N[(x$95$m * x$95$m), $MachinePrecision] + 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 0.0052:\\
\;\;\;\;\mathsf{fma}\left(-0.041666666666666664, x\_m \cdot 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 < 0.0051999999999999998

    1. Initial program 30.4%

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

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

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

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{-1}{24}, {x}^{2}, \frac{1}{2}\right)} \]
      3. unpow2N/A

        \[\leadsto \mathsf{fma}\left(\frac{-1}{24}, \color{blue}{x \cdot x}, \frac{1}{2}\right) \]
      4. lower-*.f6471.5

        \[\leadsto \mathsf{fma}\left(-0.041666666666666664, \color{blue}{x \cdot x}, 0.5\right) \]
    5. Applied rewrites71.5%

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

    if 0.0051999999999999998 < x

    1. Initial program 99.1%

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

Alternative 8: 76.2% accurate, 2.3× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 4.6:\\ \;\;\;\;\mathsf{fma}\left(x\_m \cdot x\_m, \mathsf{fma}\left(x\_m, x\_m \cdot \mathsf{fma}\left(x\_m, x\_m \cdot -2.48015873015873 \cdot 10^{-5}, 0.001388888888888889\right), -0.041666666666666664\right), 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{1}{x\_m}, \frac{1}{x\_m}, \frac{1}{x\_m \cdot \left(-x\_m\right)}\right)\\ \end{array} \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m)
 :precision binary64
 (if (<= x_m 4.6)
   (fma
    (* x_m x_m)
    (fma
     x_m
     (* x_m (fma x_m (* x_m -2.48015873015873e-5) 0.001388888888888889))
     -0.041666666666666664)
    0.5)
   (fma (/ 1.0 x_m) (/ 1.0 x_m) (/ 1.0 (* x_m (- x_m))))))
x_m = fabs(x);
double code(double x_m) {
	double tmp;
	if (x_m <= 4.6) {
		tmp = fma((x_m * x_m), fma(x_m, (x_m * fma(x_m, (x_m * -2.48015873015873e-5), 0.001388888888888889)), -0.041666666666666664), 0.5);
	} else {
		tmp = fma((1.0 / x_m), (1.0 / x_m), (1.0 / (x_m * -x_m)));
	}
	return tmp;
}
x_m = abs(x)
function code(x_m)
	tmp = 0.0
	if (x_m <= 4.6)
		tmp = fma(Float64(x_m * x_m), fma(x_m, Float64(x_m * fma(x_m, Float64(x_m * -2.48015873015873e-5), 0.001388888888888889)), -0.041666666666666664), 0.5);
	else
		tmp = fma(Float64(1.0 / x_m), Float64(1.0 / x_m), Float64(1.0 / Float64(x_m * Float64(-x_m))));
	end
	return tmp
end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := If[LessEqual[x$95$m, 4.6], N[(N[(x$95$m * x$95$m), $MachinePrecision] * N[(x$95$m * N[(x$95$m * N[(x$95$m * N[(x$95$m * -2.48015873015873e-5), $MachinePrecision] + 0.001388888888888889), $MachinePrecision]), $MachinePrecision] + -0.041666666666666664), $MachinePrecision] + 0.5), $MachinePrecision], N[(N[(1.0 / x$95$m), $MachinePrecision] * N[(1.0 / x$95$m), $MachinePrecision] + N[(1.0 / N[(x$95$m * (-x$95$m)), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
x_m = \left|x\right|

\\
\begin{array}{l}
\mathbf{if}\;x\_m \leq 4.6:\\
\;\;\;\;\mathsf{fma}\left(x\_m \cdot x\_m, \mathsf{fma}\left(x\_m, x\_m \cdot \mathsf{fma}\left(x\_m, x\_m \cdot -2.48015873015873 \cdot 10^{-5}, 0.001388888888888889\right), -0.041666666666666664\right), 0.5\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 4.5999999999999996

    1. Initial program 30.8%

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

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

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

        \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{2}, {x}^{2} \cdot \left(\frac{1}{720} + \frac{-1}{40320} \cdot {x}^{2}\right) - \frac{1}{24}, \frac{1}{2}\right)} \]
    5. Applied rewrites71.4%

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

    if 4.5999999999999996 < x

    1. Initial program 99.1%

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

      \[\leadsto \frac{1 - \color{blue}{1}}{x \cdot x} \]
    4. Step-by-step derivation
      1. Applied rewrites62.8%

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

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

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

          \[\leadsto \color{blue}{\frac{1}{x \cdot x} - \frac{1}{x \cdot x}} \]
        4. sub-negN/A

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

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

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

          \[\leadsto \frac{\color{blue}{\frac{1}{x}}}{x} + \left(\mathsf{neg}\left(\frac{1}{x \cdot x}\right)\right) \]
        8. div-invN/A

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

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

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

          \[\leadsto \mathsf{fma}\left(\frac{1}{x}, \frac{1}{x}, \color{blue}{\mathsf{neg}\left(\frac{1}{x \cdot x}\right)}\right) \]
        12. lower-/.f6463.7

          \[\leadsto \mathsf{fma}\left(\frac{1}{x}, \frac{1}{x}, -\color{blue}{\frac{1}{x \cdot x}}\right) \]
      3. Applied rewrites63.7%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{1}{x}, \frac{1}{x}, -\frac{1}{x \cdot x}\right)} \]
    5. Recombined 2 regimes into one program.
    6. Final simplification69.4%

      \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 4.6:\\ \;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, x \cdot -2.48015873015873 \cdot 10^{-5}, 0.001388888888888889\right), -0.041666666666666664\right), 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{1}{x}, \frac{1}{x}, \frac{1}{x \cdot \left(-x\right)}\right)\\ \end{array} \]
    7. Add Preprocessing

    Alternative 9: 76.0% accurate, 2.9× speedup?

    \[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 6.6 \cdot 10^{+38}:\\ \;\;\;\;\mathsf{fma}\left(x\_m \cdot x\_m, \mathsf{fma}\left(x\_m \cdot x\_m, 0.001388888888888889, -0.041666666666666664\right), 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1 - x\_m \cdot \frac{1}{x\_m}}{x\_m \cdot x\_m}\\ \end{array} \end{array} \]
    x_m = (fabs.f64 x)
    (FPCore (x_m)
     :precision binary64
     (if (<= x_m 6.6e+38)
       (fma
        (* x_m x_m)
        (fma (* x_m x_m) 0.001388888888888889 -0.041666666666666664)
        0.5)
       (/ (- 1.0 (* x_m (/ 1.0 x_m))) (* x_m x_m))))
    x_m = fabs(x);
    double code(double x_m) {
    	double tmp;
    	if (x_m <= 6.6e+38) {
    		tmp = fma((x_m * x_m), fma((x_m * x_m), 0.001388888888888889, -0.041666666666666664), 0.5);
    	} else {
    		tmp = (1.0 - (x_m * (1.0 / x_m))) / (x_m * x_m);
    	}
    	return tmp;
    }
    
    x_m = abs(x)
    function code(x_m)
    	tmp = 0.0
    	if (x_m <= 6.6e+38)
    		tmp = fma(Float64(x_m * x_m), fma(Float64(x_m * x_m), 0.001388888888888889, -0.041666666666666664), 0.5);
    	else
    		tmp = Float64(Float64(1.0 - Float64(x_m * Float64(1.0 / 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, 6.6e+38], N[(N[(x$95$m * x$95$m), $MachinePrecision] * N[(N[(x$95$m * x$95$m), $MachinePrecision] * 0.001388888888888889 + -0.041666666666666664), $MachinePrecision] + 0.5), $MachinePrecision], N[(N[(1.0 - N[(x$95$m * N[(1.0 / x$95$m), $MachinePrecision]), $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 6.6 \cdot 10^{+38}:\\
    \;\;\;\;\mathsf{fma}\left(x\_m \cdot x\_m, \mathsf{fma}\left(x\_m \cdot x\_m, 0.001388888888888889, -0.041666666666666664\right), 0.5\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\frac{1 - x\_m \cdot \frac{1}{x\_m}}{x\_m \cdot x\_m}\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if x < 6.5999999999999998e38

      1. Initial program 33.1%

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

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

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

          \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{1}{720} \cdot {x}^{2} - \frac{1}{24}, \frac{1}{2}\right)} \]
        3. unpow2N/A

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

          \[\leadsto \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{720} \cdot {x}^{2} - \frac{1}{24}, \frac{1}{2}\right) \]
        5. sub-negN/A

          \[\leadsto \mathsf{fma}\left(x \cdot x, \color{blue}{\frac{1}{720} \cdot {x}^{2} + \left(\mathsf{neg}\left(\frac{1}{24}\right)\right)}, \frac{1}{2}\right) \]
        6. metadata-evalN/A

          \[\leadsto \mathsf{fma}\left(x \cdot x, \frac{1}{720} \cdot {x}^{2} + \color{blue}{\frac{-1}{24}}, \frac{1}{2}\right) \]
        7. *-commutativeN/A

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

          \[\leadsto \mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{1}{720}, \frac{-1}{24}\right)}, \frac{1}{2}\right) \]
        9. unpow2N/A

          \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{720}, \frac{-1}{24}\right), \frac{1}{2}\right) \]
        10. lower-*.f6469.2

          \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, 0.001388888888888889, -0.041666666666666664\right), 0.5\right) \]
      5. Applied rewrites69.2%

        \[\leadsto \color{blue}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, -0.041666666666666664\right), 0.5\right)} \]

      if 6.5999999999999998e38 < x

      1. Initial program 99.4%

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

        \[\leadsto \frac{1 - \color{blue}{1}}{x \cdot x} \]
      4. Step-by-step derivation
        1. Applied rewrites69.9%

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

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

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

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

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

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

            \[\leadsto \frac{\color{blue}{\frac{1}{x}} - \frac{1}{x}}{x} \]
          7. sub-divN/A

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

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

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

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

            \[\leadsto \frac{\color{blue}{\frac{1}{x}} \cdot x - x \cdot \frac{1}{x}}{x \cdot x} \]
          12. inv-powN/A

            \[\leadsto \frac{\color{blue}{{x}^{-1}} \cdot x - x \cdot \frac{1}{x}}{x \cdot x} \]
          13. pow-plusN/A

            \[\leadsto \frac{\color{blue}{{x}^{\left(-1 + 1\right)}} - x \cdot \frac{1}{x}}{x \cdot x} \]
          14. metadata-evalN/A

            \[\leadsto \frac{{x}^{\color{blue}{0}} - x \cdot \frac{1}{x}}{x \cdot x} \]
          15. metadata-evalN/A

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

            \[\leadsto \frac{\color{blue}{1 - x \cdot \frac{1}{x}}}{x \cdot x} \]
          17. lower-*.f64N/A

            \[\leadsto \frac{1 - \color{blue}{x \cdot \frac{1}{x}}}{x \cdot x} \]
          18. lower-/.f6470.0

            \[\leadsto \frac{1 - x \cdot \color{blue}{\frac{1}{x}}}{x \cdot x} \]
        3. Applied rewrites70.0%

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

      Alternative 10: 75.9% accurate, 4.1× speedup?

      \[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 6.6 \cdot 10^{+38}:\\ \;\;\;\;\mathsf{fma}\left(x\_m \cdot x\_m, \mathsf{fma}\left(x\_m \cdot x\_m, 0.001388888888888889, -0.041666666666666664\right), 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1 - 1}{x\_m \cdot x\_m}\\ \end{array} \end{array} \]
      x_m = (fabs.f64 x)
      (FPCore (x_m)
       :precision binary64
       (if (<= x_m 6.6e+38)
         (fma
          (* x_m x_m)
          (fma (* x_m x_m) 0.001388888888888889 -0.041666666666666664)
          0.5)
         (/ (- 1.0 1.0) (* x_m x_m))))
      x_m = fabs(x);
      double code(double x_m) {
      	double tmp;
      	if (x_m <= 6.6e+38) {
      		tmp = fma((x_m * x_m), fma((x_m * x_m), 0.001388888888888889, -0.041666666666666664), 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 <= 6.6e+38)
      		tmp = fma(Float64(x_m * x_m), fma(Float64(x_m * x_m), 0.001388888888888889, -0.041666666666666664), 0.5);
      	else
      		tmp = Float64(Float64(1.0 - 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, 6.6e+38], N[(N[(x$95$m * x$95$m), $MachinePrecision] * N[(N[(x$95$m * x$95$m), $MachinePrecision] * 0.001388888888888889 + -0.041666666666666664), $MachinePrecision] + 0.5), $MachinePrecision], 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 6.6 \cdot 10^{+38}:\\
      \;\;\;\;\mathsf{fma}\left(x\_m \cdot x\_m, \mathsf{fma}\left(x\_m \cdot x\_m, 0.001388888888888889, -0.041666666666666664\right), 0.5\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\frac{1 - 1}{x\_m \cdot x\_m}\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if x < 6.5999999999999998e38

        1. Initial program 33.1%

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

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

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

            \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{1}{720} \cdot {x}^{2} - \frac{1}{24}, \frac{1}{2}\right)} \]
          3. unpow2N/A

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

            \[\leadsto \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{720} \cdot {x}^{2} - \frac{1}{24}, \frac{1}{2}\right) \]
          5. sub-negN/A

            \[\leadsto \mathsf{fma}\left(x \cdot x, \color{blue}{\frac{1}{720} \cdot {x}^{2} + \left(\mathsf{neg}\left(\frac{1}{24}\right)\right)}, \frac{1}{2}\right) \]
          6. metadata-evalN/A

            \[\leadsto \mathsf{fma}\left(x \cdot x, \frac{1}{720} \cdot {x}^{2} + \color{blue}{\frac{-1}{24}}, \frac{1}{2}\right) \]
          7. *-commutativeN/A

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

            \[\leadsto \mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{1}{720}, \frac{-1}{24}\right)}, \frac{1}{2}\right) \]
          9. unpow2N/A

            \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{720}, \frac{-1}{24}\right), \frac{1}{2}\right) \]
          10. lower-*.f6469.2

            \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, 0.001388888888888889, -0.041666666666666664\right), 0.5\right) \]
        5. Applied rewrites69.2%

          \[\leadsto \color{blue}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, -0.041666666666666664\right), 0.5\right)} \]

        if 6.5999999999999998e38 < x

        1. Initial program 99.4%

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

          \[\leadsto \frac{1 - \color{blue}{1}}{x \cdot x} \]
        4. Step-by-step derivation
          1. Applied rewrites69.9%

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

        Alternative 11: 75.7% accurate, 4.6× speedup?

        \[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 6 \cdot 10^{+76}:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{1 - 1}{x\_m \cdot x\_m}\\ \end{array} \end{array} \]
        x_m = (fabs.f64 x)
        (FPCore (x_m)
         :precision binary64
         (if (<= x_m 6e+76) 0.5 (/ (- 1.0 1.0) (* x_m x_m))))
        x_m = fabs(x);
        double code(double x_m) {
        	double tmp;
        	if (x_m <= 6e+76) {
        		tmp = 0.5;
        	} else {
        		tmp = (1.0 - 1.0) / (x_m * x_m);
        	}
        	return tmp;
        }
        
        x_m = abs(x)
        real(8) function code(x_m)
            real(8), intent (in) :: x_m
            real(8) :: tmp
            if (x_m <= 6d+76) 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 <= 6e+76) {
        		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 <= 6e+76:
        		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 <= 6e+76)
        		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 <= 6e+76)
        		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, 6e+76], 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 6 \cdot 10^{+76}:\\
        \;\;\;\;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 < 5.9999999999999996e76

          1. Initial program 35.0%

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

            \[\leadsto \color{blue}{\frac{1}{2}} \]
          4. Step-by-step derivation
            1. Applied rewrites67.6%

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

            if 5.9999999999999996e76 < x

            1. Initial program 99.5%

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

              \[\leadsto \frac{1 - \color{blue}{1}}{x \cdot x} \]
            4. Step-by-step derivation
              1. Applied rewrites77.3%

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

            Alternative 12: 51.6% accurate, 120.0× 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 = abs(x)
            real(8) function code(x_m)
                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 48.4%

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

              \[\leadsto \color{blue}{\frac{1}{2}} \]
            4. Step-by-step derivation
              1. Applied rewrites54.3%

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

              Reproduce

              ?
              herbie shell --seed 2024222 
              (FPCore (x)
                :name "cos2 (problem 3.4.1)"
                :precision binary64
                (/ (- 1.0 (cos x)) (* x x)))