cos2 (problem 3.4.1)

Percentage Accurate: 50.3% → 99.8%
Time: 11.7s
Alternatives: 10
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 10 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 50.3% 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?

\[\begin{array}{l} \\ \frac{\frac{\sin x}{x} \cdot \tan \left(x \cdot 0.5\right)}{x} \end{array} \]
(FPCore (x) :precision binary64 (/ (* (/ (sin x) x) (tan (* x 0.5))) x))
double code(double x) {
	return ((sin(x) / x) * tan((x * 0.5))) / x;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = ((sin(x) / x) * tan((x * 0.5d0))) / x
end function
public static double code(double x) {
	return ((Math.sin(x) / x) * Math.tan((x * 0.5))) / x;
}
def code(x):
	return ((math.sin(x) / x) * math.tan((x * 0.5))) / x
function code(x)
	return Float64(Float64(Float64(sin(x) / x) * tan(Float64(x * 0.5))) / x)
end
function tmp = code(x)
	tmp = ((sin(x) / x) * tan((x * 0.5))) / x;
end
code[x_] := N[(N[(N[(N[Sin[x], $MachinePrecision] / x), $MachinePrecision] * N[Tan[N[(x * 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{\sin x}{x} \cdot \tan \left(x \cdot 0.5\right)}{x}
\end{array}
Derivation
  1. Initial program 55.0%

    \[\frac{1 - \cos x}{x \cdot x} \]
  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-/.f6480.0

      \[\leadsto \frac{\sin x}{x \cdot x} \cdot \tan \color{blue}{\left(\frac{x}{2}\right)} \]
  4. Applied rewrites80.0%

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{\frac{\sin x}{x} \cdot \tan \left(x \cdot \color{blue}{\frac{1}{2}}\right)}{x} \]
    12. lower-*.f6499.8

      \[\leadsto \frac{\frac{\sin x}{x} \cdot \tan \color{blue}{\left(x \cdot 0.5\right)}}{x} \]
  6. Applied rewrites99.8%

    \[\leadsto \color{blue}{\frac{\frac{\sin x}{x} \cdot \tan \left(x \cdot 0.5\right)}{x}} \]
  7. Add Preprocessing

Alternative 2: 99.3% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \frac{\tan \left(x \cdot 0.5\right)}{x \cdot \frac{x}{\sin x}} \end{array} \]
(FPCore (x) :precision binary64 (/ (tan (* x 0.5)) (* x (/ x (sin x)))))
double code(double x) {
	return tan((x * 0.5)) / (x * (x / sin(x)));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = tan((x * 0.5d0)) / (x * (x / sin(x)))
end function
public static double code(double x) {
	return Math.tan((x * 0.5)) / (x * (x / Math.sin(x)));
}
def code(x):
	return math.tan((x * 0.5)) / (x * (x / math.sin(x)))
function code(x)
	return Float64(tan(Float64(x * 0.5)) / Float64(x * Float64(x / sin(x))))
end
function tmp = code(x)
	tmp = tan((x * 0.5)) / (x * (x / sin(x)));
end
code[x_] := N[(N[Tan[N[(x * 0.5), $MachinePrecision]], $MachinePrecision] / N[(x * N[(x / N[Sin[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\tan \left(x \cdot 0.5\right)}{x \cdot \frac{x}{\sin x}}
\end{array}
Derivation
  1. Initial program 55.0%

    \[\frac{1 - \cos x}{x \cdot x} \]
  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-/.f6480.0

      \[\leadsto \frac{\sin x}{x \cdot x} \cdot \tan \color{blue}{\left(\frac{x}{2}\right)} \]
  4. Applied rewrites80.0%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    \[\leadsto \color{blue}{\frac{\tan \left(x \cdot 0.5\right)}{x \cdot \frac{x}{\sin x}}} \]
  7. Add Preprocessing

Alternative 3: 75.2% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 0.032:\\ \;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, -0.041666666666666664\right), 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{-1}{\frac{x}{\cos x + -1}}}{x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 0.032)
   (fma (* x x) (fma (* x x) 0.001388888888888889 -0.041666666666666664) 0.5)
   (/ (/ -1.0 (/ x (+ (cos x) -1.0))) x)))
double code(double x) {
	double tmp;
	if (x <= 0.032) {
		tmp = fma((x * x), fma((x * x), 0.001388888888888889, -0.041666666666666664), 0.5);
	} else {
		tmp = (-1.0 / (x / (cos(x) + -1.0))) / x;
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= 0.032)
		tmp = fma(Float64(x * x), fma(Float64(x * x), 0.001388888888888889, -0.041666666666666664), 0.5);
	else
		tmp = Float64(Float64(-1.0 / Float64(x / Float64(cos(x) + -1.0))) / x);
	end
	return tmp
end
code[x_] := If[LessEqual[x, 0.032], N[(N[(x * x), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * 0.001388888888888889 + -0.041666666666666664), $MachinePrecision] + 0.5), $MachinePrecision], N[(N[(-1.0 / N[(x / N[(N[Cos[x], $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 0.032:\\
\;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, -0.041666666666666664\right), 0.5\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 0.032000000000000001

    1. Initial program 39.6%

      \[\frac{1 - \cos x}{x \cdot x} \]
    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-*.f6463.4

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, 0.001388888888888889, -0.041666666666666664\right), 0.5\right) \]
    5. Applied rewrites63.4%

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

    if 0.032000000000000001 < x

    1. Initial program 96.7%

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

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

        \[\leadsto \frac{\color{blue}{\frac{\cos x + -1}{x}}}{\mathsf{neg}\left(x\right)} \]
      2. clear-numN/A

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

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x}{\cos x + -1}}}}{\mathsf{neg}\left(x\right)} \]
      4. lower-/.f6499.3

        \[\leadsto \frac{\frac{1}{\color{blue}{\frac{x}{\cos x + -1}}}}{-x} \]
    5. Applied rewrites99.3%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{x}{\cos x + -1}}}}{-x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification73.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 0.032:\\ \;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, -0.041666666666666664\right), 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{-1}{\frac{x}{\cos x + -1}}}{x}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 75.2% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 0.032:\\ \;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, -0.041666666666666664\right), 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\cos x + -1\right) \cdot \frac{\frac{-1}{x}}{x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 0.032)
   (fma (* x x) (fma (* x x) 0.001388888888888889 -0.041666666666666664) 0.5)
   (* (+ (cos x) -1.0) (/ (/ -1.0 x) x))))
double code(double x) {
	double tmp;
	if (x <= 0.032) {
		tmp = fma((x * x), fma((x * x), 0.001388888888888889, -0.041666666666666664), 0.5);
	} else {
		tmp = (cos(x) + -1.0) * ((-1.0 / x) / x);
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= 0.032)
		tmp = fma(Float64(x * x), fma(Float64(x * x), 0.001388888888888889, -0.041666666666666664), 0.5);
	else
		tmp = Float64(Float64(cos(x) + -1.0) * Float64(Float64(-1.0 / x) / x));
	end
	return tmp
end
code[x_] := If[LessEqual[x, 0.032], N[(N[(x * x), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * 0.001388888888888889 + -0.041666666666666664), $MachinePrecision] + 0.5), $MachinePrecision], N[(N[(N[Cos[x], $MachinePrecision] + -1.0), $MachinePrecision] * N[(N[(-1.0 / x), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 0.032:\\
\;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, -0.041666666666666664\right), 0.5\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 0.032000000000000001

    1. Initial program 39.6%

      \[\frac{1 - \cos x}{x \cdot x} \]
    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-*.f6463.4

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, 0.001388888888888889, -0.041666666666666664\right), 0.5\right) \]
    5. Applied rewrites63.4%

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

    if 0.032000000000000001 < x

    1. Initial program 96.7%

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

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

        \[\leadsto \color{blue}{\frac{\frac{\cos x + -1}{x}}{\mathsf{neg}\left(x\right)}} \]
      2. clear-numN/A

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(\frac{\mathsf{neg}\left(-1\right)}{\color{blue}{\mathsf{neg}\left(x\right)}} \cdot \frac{1}{x}\right) \cdot \left(\cos x + -1\right) \]
      12. frac-2negN/A

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

        \[\leadsto \left(\color{blue}{\frac{-1}{x}} \cdot \frac{1}{x}\right) \cdot \left(\cos x + -1\right) \]
      14. lower-/.f6499.2

        \[\leadsto \left(\frac{-1}{x} \cdot \color{blue}{\frac{1}{x}}\right) \cdot \left(\cos x + -1\right) \]
    5. Applied rewrites99.2%

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

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

        \[\leadsto \left(\frac{-1}{x} \cdot \color{blue}{\frac{1}{x}}\right) \cdot \left(\cos x + -1\right) \]
      3. un-div-invN/A

        \[\leadsto \color{blue}{\frac{\frac{-1}{x}}{x}} \cdot \left(\cos x + -1\right) \]
      4. lower-/.f6499.3

        \[\leadsto \color{blue}{\frac{\frac{-1}{x}}{x}} \cdot \left(\cos x + -1\right) \]
    7. Applied rewrites99.3%

      \[\leadsto \color{blue}{\frac{\frac{-1}{x}}{x}} \cdot \left(\cos x + -1\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification73.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 0.032:\\ \;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, -0.041666666666666664\right), 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\cos x + -1\right) \cdot \frac{\frac{-1}{x}}{x}\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 75.2% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 0.032:\\ \;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, -0.041666666666666664\right), 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{1 - \cos x}{x}}{x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 0.032)
   (fma (* x x) (fma (* x x) 0.001388888888888889 -0.041666666666666664) 0.5)
   (/ (/ (- 1.0 (cos x)) x) x)))
double code(double x) {
	double tmp;
	if (x <= 0.032) {
		tmp = fma((x * x), fma((x * x), 0.001388888888888889, -0.041666666666666664), 0.5);
	} else {
		tmp = ((1.0 - cos(x)) / x) / x;
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= 0.032)
		tmp = fma(Float64(x * x), fma(Float64(x * x), 0.001388888888888889, -0.041666666666666664), 0.5);
	else
		tmp = Float64(Float64(Float64(1.0 - cos(x)) / x) / x);
	end
	return tmp
end
code[x_] := If[LessEqual[x, 0.032], N[(N[(x * x), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * 0.001388888888888889 + -0.041666666666666664), $MachinePrecision] + 0.5), $MachinePrecision], N[(N[(N[(1.0 - N[Cos[x], $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision] / x), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 0.032:\\
\;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, -0.041666666666666664\right), 0.5\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 0.032000000000000001

    1. Initial program 39.6%

      \[\frac{1 - \cos x}{x \cdot x} \]
    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-*.f6463.4

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, 0.001388888888888889, -0.041666666666666664\right), 0.5\right) \]
    5. Applied rewrites63.4%

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

    if 0.032000000000000001 < x

    1. Initial program 96.7%

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\frac{\color{blue}{1} + \left(\mathsf{neg}\left(\cos x\right)\right)}{x}}{x} \]
      12. sub-negN/A

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

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

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

        \[\leadsto \frac{\frac{1 - \color{blue}{\cos x}}{x}}{x} \]
      16. lower--.f6499.3

        \[\leadsto \frac{\frac{\color{blue}{1 - \cos x}}{x}}{x} \]
    5. Applied rewrites99.3%

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

Alternative 6: 75.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 0.032:\\ \;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, -0.041666666666666664\right), 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1 - \cos x}{x \cdot x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 0.032)
   (fma (* x x) (fma (* x x) 0.001388888888888889 -0.041666666666666664) 0.5)
   (/ (- 1.0 (cos x)) (* x x))))
double code(double x) {
	double tmp;
	if (x <= 0.032) {
		tmp = fma((x * x), fma((x * x), 0.001388888888888889, -0.041666666666666664), 0.5);
	} else {
		tmp = (1.0 - cos(x)) / (x * x);
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= 0.032)
		tmp = fma(Float64(x * x), fma(Float64(x * x), 0.001388888888888889, -0.041666666666666664), 0.5);
	else
		tmp = Float64(Float64(1.0 - cos(x)) / Float64(x * x));
	end
	return tmp
end
code[x_] := If[LessEqual[x, 0.032], N[(N[(x * x), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * 0.001388888888888889 + -0.041666666666666664), $MachinePrecision] + 0.5), $MachinePrecision], N[(N[(1.0 - N[Cos[x], $MachinePrecision]), $MachinePrecision] / N[(x * x), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 0.032:\\
\;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, -0.041666666666666664\right), 0.5\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 0.032000000000000001

    1. Initial program 39.6%

      \[\frac{1 - \cos x}{x \cdot x} \]
    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-*.f6463.4

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, 0.001388888888888889, -0.041666666666666664\right), 0.5\right) \]
    5. Applied rewrites63.4%

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

    if 0.032000000000000001 < x

    1. Initial program 96.7%

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

Alternative 7: 63.3% accurate, 4.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 7 \cdot 10^{+38}:\\ \;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, -0.041666666666666664\right), 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1 - 1}{x \cdot x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 7e+38)
   (fma (* x x) (fma (* x x) 0.001388888888888889 -0.041666666666666664) 0.5)
   (/ (- 1.0 1.0) (* x x))))
double code(double x) {
	double tmp;
	if (x <= 7e+38) {
		tmp = fma((x * x), fma((x * x), 0.001388888888888889, -0.041666666666666664), 0.5);
	} else {
		tmp = (1.0 - 1.0) / (x * x);
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= 7e+38)
		tmp = fma(Float64(x * x), fma(Float64(x * x), 0.001388888888888889, -0.041666666666666664), 0.5);
	else
		tmp = Float64(Float64(1.0 - 1.0) / Float64(x * x));
	end
	return tmp
end
code[x_] := If[LessEqual[x, 7e+38], N[(N[(x * x), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * 0.001388888888888889 + -0.041666666666666664), $MachinePrecision] + 0.5), $MachinePrecision], N[(N[(1.0 - 1.0), $MachinePrecision] / N[(x * x), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 7 \cdot 10^{+38}:\\
\;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, -0.041666666666666664\right), 0.5\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 7.00000000000000003e38

    1. Initial program 41.1%

      \[\frac{1 - \cos x}{x \cdot x} \]
    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-*.f6462.0

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, 0.001388888888888889, -0.041666666666666664\right), 0.5\right) \]
    5. Applied rewrites62.0%

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

    if 7.00000000000000003e38 < x

    1. Initial program 96.4%

      \[\frac{1 - \cos x}{x \cdot x} \]
    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 rewrites56.1%

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

    Alternative 8: 62.9% accurate, 4.6× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 3.5:\\ \;\;\;\;\mathsf{fma}\left(-0.041666666666666664, x \cdot x, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1 - 1}{x \cdot x}\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (<= x 3.5)
       (fma -0.041666666666666664 (* x x) 0.5)
       (/ (- 1.0 1.0) (* x x))))
    double code(double x) {
    	double tmp;
    	if (x <= 3.5) {
    		tmp = fma(-0.041666666666666664, (x * x), 0.5);
    	} else {
    		tmp = (1.0 - 1.0) / (x * x);
    	}
    	return tmp;
    }
    
    function code(x)
    	tmp = 0.0
    	if (x <= 3.5)
    		tmp = fma(-0.041666666666666664, Float64(x * x), 0.5);
    	else
    		tmp = Float64(Float64(1.0 - 1.0) / Float64(x * x));
    	end
    	return tmp
    end
    
    code[x_] := If[LessEqual[x, 3.5], N[(-0.041666666666666664 * N[(x * x), $MachinePrecision] + 0.5), $MachinePrecision], N[(N[(1.0 - 1.0), $MachinePrecision] / N[(x * x), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq 3.5:\\
    \;\;\;\;\mathsf{fma}\left(-0.041666666666666664, x \cdot x, 0.5\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\frac{1 - 1}{x \cdot x}\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if x < 3.5

      1. Initial program 39.6%

        \[\frac{1 - \cos x}{x \cdot x} \]
      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-*.f6463.1

          \[\leadsto \mathsf{fma}\left(-0.041666666666666664, \color{blue}{x \cdot x}, 0.5\right) \]
      5. Applied rewrites63.1%

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

      if 3.5 < x

      1. Initial program 96.7%

        \[\frac{1 - \cos x}{x \cdot x} \]
      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 rewrites52.3%

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

      Alternative 9: 78.6% accurate, 5.2× speedup?

      \[\begin{array}{l} \\ \frac{1}{\mathsf{fma}\left(x, x \cdot 0.16666666666666666, 2\right)} \end{array} \]
      (FPCore (x) :precision binary64 (/ 1.0 (fma x (* x 0.16666666666666666) 2.0)))
      double code(double x) {
      	return 1.0 / fma(x, (x * 0.16666666666666666), 2.0);
      }
      
      function code(x)
      	return Float64(1.0 / fma(x, Float64(x * 0.16666666666666666), 2.0))
      end
      
      code[x_] := N[(1.0 / N[(x * N[(x * 0.16666666666666666), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \frac{1}{\mathsf{fma}\left(x, x \cdot 0.16666666666666666, 2\right)}
      \end{array}
      
      Derivation
      1. Initial program 55.0%

        \[\frac{1 - \cos x}{x \cdot x} \]
      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. frac-subN/A

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

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

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

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

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

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

          \[\leadsto \frac{1}{\frac{x \cdot \left(x \cdot \color{blue}{\left(x \cdot x\right)}\right)}{1 \cdot \left(x \cdot x\right) - \left(x \cdot x\right) \cdot \cos x}} \]
        11. cube-unmultN/A

          \[\leadsto \frac{1}{\frac{x \cdot \color{blue}{{x}^{3}}}{1 \cdot \left(x \cdot x\right) - \left(x \cdot x\right) \cdot \cos x}} \]
        12. lower-*.f64N/A

          \[\leadsto \frac{1}{\frac{\color{blue}{x \cdot {x}^{3}}}{1 \cdot \left(x \cdot x\right) - \left(x \cdot x\right) \cdot \cos x}} \]
        13. cube-unmultN/A

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

          \[\leadsto \frac{1}{\frac{x \cdot \left(x \cdot \color{blue}{\left(x \cdot x\right)}\right)}{1 \cdot \left(x \cdot x\right) - \left(x \cdot x\right) \cdot \cos x}} \]
        15. lower-*.f64N/A

          \[\leadsto \frac{1}{\frac{x \cdot \color{blue}{\left(x \cdot \left(x \cdot x\right)\right)}}{1 \cdot \left(x \cdot x\right) - \left(x \cdot x\right) \cdot \cos x}} \]
        16. *-lft-identityN/A

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

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

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

          \[\leadsto \frac{1}{\frac{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}{x \cdot x - \color{blue}{x \cdot \left(x \cdot \cos x\right)}}} \]
        20. lower-*.f64N/A

          \[\leadsto \frac{1}{\frac{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}{x \cdot x - \color{blue}{x \cdot \left(x \cdot \cos x\right)}}} \]
        21. lower-*.f6417.3

          \[\leadsto \frac{1}{\frac{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}{x \cdot x - x \cdot \color{blue}{\left(x \cdot \cos x\right)}}} \]
      4. Applied rewrites17.3%

        \[\leadsto \color{blue}{\frac{1}{\frac{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}{x \cdot x - x \cdot \left(x \cdot \cos x\right)}}} \]
      5. Taylor expanded in x around 0

        \[\leadsto \frac{1}{\color{blue}{2 + \frac{1}{6} \cdot {x}^{2}}} \]
      6. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto \frac{1}{\color{blue}{\frac{1}{6} \cdot {x}^{2} + 2}} \]
        2. unpow2N/A

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

          \[\leadsto \frac{1}{\color{blue}{\left(\frac{1}{6} \cdot x\right) \cdot x} + 2} \]
        4. *-commutativeN/A

          \[\leadsto \frac{1}{\color{blue}{x \cdot \left(\frac{1}{6} \cdot x\right)} + 2} \]
        5. lower-fma.f64N/A

          \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left(x, \frac{1}{6} \cdot x, 2\right)}} \]
        6. *-commutativeN/A

          \[\leadsto \frac{1}{\mathsf{fma}\left(x, \color{blue}{x \cdot \frac{1}{6}}, 2\right)} \]
        7. lower-*.f6476.3

          \[\leadsto \frac{1}{\mathsf{fma}\left(x, \color{blue}{x \cdot 0.16666666666666666}, 2\right)} \]
      7. Applied rewrites76.3%

        \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left(x, x \cdot 0.16666666666666666, 2\right)}} \]
      8. Add Preprocessing

      Alternative 10: 52.1% accurate, 120.0× speedup?

      \[\begin{array}{l} \\ 0.5 \end{array} \]
      (FPCore (x) :precision binary64 0.5)
      double code(double x) {
      	return 0.5;
      }
      
      real(8) function code(x)
          real(8), intent (in) :: x
          code = 0.5d0
      end function
      
      public static double code(double x) {
      	return 0.5;
      }
      
      def code(x):
      	return 0.5
      
      function code(x)
      	return 0.5
      end
      
      function tmp = code(x)
      	tmp = 0.5;
      end
      
      code[x_] := 0.5
      
      \begin{array}{l}
      
      \\
      0.5
      \end{array}
      
      Derivation
      1. Initial program 55.0%

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

        \[\leadsto \color{blue}{\frac{1}{2}} \]
      4. Step-by-step derivation
        1. Applied rewrites47.4%

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

        Reproduce

        ?
        herbie shell --seed 2024219 
        (FPCore (x)
          :name "cos2 (problem 3.4.1)"
          :precision binary64
          (/ (- 1.0 (cos x)) (* x x)))