cos2 (problem 3.4.1)

Percentage Accurate: 50.8% → 99.6%
Time: 2.9s
Alternatives: 8
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);
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

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

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

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 8 alternatives:

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

Initial Program: 50.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{1 - \cos x}{x \cdot x} \end{array} \]
(FPCore (x) :precision binary64 (/ (- 1.0 (cos x)) (* x x)))
double code(double x) {
	return (1.0 - cos(x)) / (x * x);
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

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

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

Alternative 1: 99.6% accurate, 0.9× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 0.096:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-2.48015873015873 \cdot 10^{-5}, x\_m \cdot x\_m, 0.001388888888888889\right), x\_m \cdot x\_m, -0.041666666666666664\right), x\_m \cdot x\_m, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{-1 + \cos x\_m}{x\_m} \cdot \frac{-1}{x\_m}\\ \end{array} \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m)
 :precision binary64
 (if (<= x_m 0.096)
   (fma
    (fma
     (fma -2.48015873015873e-5 (* x_m x_m) 0.001388888888888889)
     (* x_m x_m)
     -0.041666666666666664)
    (* x_m x_m)
    0.5)
   (* (/ (+ -1.0 (cos x_m)) x_m) (/ -1.0 x_m))))
x_m = fabs(x);
double code(double x_m) {
	double tmp;
	if (x_m <= 0.096) {
		tmp = fma(fma(fma(-2.48015873015873e-5, (x_m * x_m), 0.001388888888888889), (x_m * x_m), -0.041666666666666664), (x_m * x_m), 0.5);
	} else {
		tmp = ((-1.0 + cos(x_m)) / x_m) * (-1.0 / x_m);
	}
	return tmp;
}
x_m = abs(x)
function code(x_m)
	tmp = 0.0
	if (x_m <= 0.096)
		tmp = fma(fma(fma(-2.48015873015873e-5, Float64(x_m * x_m), 0.001388888888888889), Float64(x_m * x_m), -0.041666666666666664), Float64(x_m * x_m), 0.5);
	else
		tmp = Float64(Float64(Float64(-1.0 + cos(x_m)) / x_m) * Float64(-1.0 / x_m));
	end
	return tmp
end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := If[LessEqual[x$95$m, 0.096], N[(N[(N[(-2.48015873015873e-5 * N[(x$95$m * x$95$m), $MachinePrecision] + 0.001388888888888889), $MachinePrecision] * N[(x$95$m * x$95$m), $MachinePrecision] + -0.041666666666666664), $MachinePrecision] * 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] * N[(-1.0 / x$95$m), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
x_m = \left|x\right|

\\
\begin{array}{l}
\mathbf{if}\;x\_m \leq 0.096:\\
\;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-2.48015873015873 \cdot 10^{-5}, x\_m \cdot x\_m, 0.001388888888888889\right), x\_m \cdot x\_m, -0.041666666666666664\right), x\_m \cdot x\_m, 0.5\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 0.096000000000000002

    1. Initial program 32.3%

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

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

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

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

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

        \[\leadsto \frac{\color{blue}{\frac{1 \cdot 1 - \cos x \cdot \cos x}{1 + \cos x}}}{x \cdot x} \]
      6. pow2N/A

        \[\leadsto \frac{\frac{1 \cdot 1 - \cos x \cdot \cos x}{1 + \cos x}}{\color{blue}{{x}^{2}}} \]
      7. associate-/l/N/A

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

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

        \[\leadsto \frac{\color{blue}{1} - \cos x \cdot \cos x}{\left(1 + \cos x\right) \cdot {x}^{2}} \]
      10. 1-sub-cosN/A

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

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

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

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

        \[\leadsto \frac{\sin x \cdot \sin x}{\color{blue}{\left(1 + \cos x\right) \cdot {x}^{2}}} \]
      15. +-commutativeN/A

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

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

        \[\leadsto \frac{\sin x \cdot \sin x}{\left(\color{blue}{\cos x} + 1\right) \cdot {x}^{2}} \]
      18. pow2N/A

        \[\leadsto \frac{\sin x \cdot \sin x}{\left(\cos x + 1\right) \cdot \color{blue}{\left(x \cdot x\right)}} \]
      19. lift-*.f6463.5

        \[\leadsto \frac{\sin x \cdot \sin x}{\left(\cos x + 1\right) \cdot \color{blue}{\left(x \cdot x\right)}} \]
    4. Applied rewrites63.5%

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

      \[\leadsto \color{blue}{\frac{1}{2} + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{1}{720} + \frac{-1}{40320} \cdot {x}^{2}\right) - \frac{1}{24}\right)} \]
    6. Applied rewrites70.6%

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

    if 0.096000000000000002 < x

    1. Initial program 97.4%

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

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

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

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

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

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

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

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

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

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

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

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

Alternative 2: 99.7% accurate, 0.5× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \frac{\frac{\sin x\_m}{x\_m}}{x\_m} \cdot \tan \left(0.5 \cdot x\_m\right) \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m)
 :precision binary64
 (* (/ (/ (sin x_m) x_m) x_m) (tan (* 0.5 x_m))))
x_m = fabs(x);
double code(double x_m) {
	return ((sin(x_m) / x_m) / x_m) * tan((0.5 * x_m));
}
x_m =     private
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

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

\\
\frac{\frac{\sin x\_m}{x\_m}}{x\_m} \cdot \tan \left(0.5 \cdot x\_m\right)
\end{array}
Derivation
  1. Initial program 49.1%

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

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

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

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

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

      \[\leadsto \frac{\color{blue}{\frac{1 \cdot 1 - \cos x \cdot \cos x}{1 + \cos x}}}{x \cdot x} \]
    6. pow2N/A

      \[\leadsto \frac{\frac{1 \cdot 1 - \cos x \cdot \cos x}{1 + \cos x}}{\color{blue}{{x}^{2}}} \]
    7. associate-/l/N/A

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

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

      \[\leadsto \frac{\color{blue}{1} - \cos x \cdot \cos x}{\left(1 + \cos x\right) \cdot {x}^{2}} \]
    10. 1-sub-cosN/A

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

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

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

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

      \[\leadsto \frac{\sin x \cdot \sin x}{\color{blue}{\left(1 + \cos x\right) \cdot {x}^{2}}} \]
    15. +-commutativeN/A

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

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

      \[\leadsto \frac{\sin x \cdot \sin x}{\left(\color{blue}{\cos x} + 1\right) \cdot {x}^{2}} \]
    18. pow2N/A

      \[\leadsto \frac{\sin x \cdot \sin x}{\left(\cos x + 1\right) \cdot \color{blue}{\left(x \cdot x\right)}} \]
    19. lift-*.f6472.2

      \[\leadsto \frac{\sin x \cdot \sin x}{\left(\cos x + 1\right) \cdot \color{blue}{\left(x \cdot x\right)}} \]
  4. Applied rewrites72.2%

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

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

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

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

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

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

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

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

      \[\leadsto \frac{\sin x \cdot \sin x}{\left(\cos x + 1\right) \cdot \color{blue}{\left(x \cdot x\right)}} \]
    9. pow2N/A

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

      \[\leadsto \frac{\sin x \cdot \sin x}{\color{blue}{{x}^{2} \cdot \left(\cos x + 1\right)}} \]
    11. +-commutativeN/A

      \[\leadsto \frac{\sin x \cdot \sin x}{{x}^{2} \cdot \color{blue}{\left(1 + \cos x\right)}} \]
    12. pow2N/A

      \[\leadsto \frac{\color{blue}{{\sin x}^{2}}}{{x}^{2} \cdot \left(1 + \cos x\right)} \]
    13. pow2N/A

      \[\leadsto \frac{\color{blue}{\sin x \cdot \sin x}}{{x}^{2} \cdot \left(1 + \cos x\right)} \]
    14. +-commutativeN/A

      \[\leadsto \frac{\sin x \cdot \sin x}{{x}^{2} \cdot \color{blue}{\left(\cos x + 1\right)}} \]
    15. times-fracN/A

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

      \[\leadsto \color{blue}{\frac{\sin x}{{x}^{2}} \cdot \frac{\sin x}{\cos x + 1}} \]
  6. Applied rewrites99.3%

    \[\leadsto \color{blue}{\frac{\frac{\sin x}{x}}{x} \cdot \tan \left(\frac{x}{2}\right)} \]
  7. Taylor expanded in x around 0

    \[\leadsto \frac{\frac{\sin x}{x}}{x} \cdot \tan \color{blue}{\left(\frac{1}{2} \cdot x\right)} \]
  8. Step-by-step derivation
    1. lower-*.f6499.3

      \[\leadsto \frac{\frac{\sin x}{x}}{x} \cdot \tan \left(0.5 \cdot \color{blue}{x}\right) \]
  9. Applied rewrites99.3%

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

Alternative 3: 99.7% accurate, 0.9× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 0.096:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-2.48015873015873 \cdot 10^{-5}, x\_m \cdot x\_m, 0.001388888888888889\right), x\_m \cdot x\_m, -0.041666666666666664\right), x\_m \cdot x\_m, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{1 - \cos x\_m}{x\_m}}{x\_m}\\ \end{array} \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m)
 :precision binary64
 (if (<= x_m 0.096)
   (fma
    (fma
     (fma -2.48015873015873e-5 (* x_m x_m) 0.001388888888888889)
     (* x_m x_m)
     -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 <= 0.096) {
		tmp = fma(fma(fma(-2.48015873015873e-5, (x_m * x_m), 0.001388888888888889), (x_m * x_m), -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 <= 0.096)
		tmp = fma(fma(fma(-2.48015873015873e-5, Float64(x_m * x_m), 0.001388888888888889), Float64(x_m * x_m), -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, 0.096], N[(N[(N[(-2.48015873015873e-5 * N[(x$95$m * x$95$m), $MachinePrecision] + 0.001388888888888889), $MachinePrecision] * N[(x$95$m * x$95$m), $MachinePrecision] + -0.041666666666666664), $MachinePrecision] * 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 0.096:\\
\;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-2.48015873015873 \cdot 10^{-5}, x\_m \cdot x\_m, 0.001388888888888889\right), x\_m \cdot x\_m, -0.041666666666666664\right), 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 < 0.096000000000000002

    1. Initial program 32.3%

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

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

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

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

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

        \[\leadsto \frac{\color{blue}{\frac{1 \cdot 1 - \cos x \cdot \cos x}{1 + \cos x}}}{x \cdot x} \]
      6. pow2N/A

        \[\leadsto \frac{\frac{1 \cdot 1 - \cos x \cdot \cos x}{1 + \cos x}}{\color{blue}{{x}^{2}}} \]
      7. associate-/l/N/A

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

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

        \[\leadsto \frac{\color{blue}{1} - \cos x \cdot \cos x}{\left(1 + \cos x\right) \cdot {x}^{2}} \]
      10. 1-sub-cosN/A

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

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

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

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

        \[\leadsto \frac{\sin x \cdot \sin x}{\color{blue}{\left(1 + \cos x\right) \cdot {x}^{2}}} \]
      15. +-commutativeN/A

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

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

        \[\leadsto \frac{\sin x \cdot \sin x}{\left(\color{blue}{\cos x} + 1\right) \cdot {x}^{2}} \]
      18. pow2N/A

        \[\leadsto \frac{\sin x \cdot \sin x}{\left(\cos x + 1\right) \cdot \color{blue}{\left(x \cdot x\right)}} \]
      19. lift-*.f6463.5

        \[\leadsto \frac{\sin x \cdot \sin x}{\left(\cos x + 1\right) \cdot \color{blue}{\left(x \cdot x\right)}} \]
    4. Applied rewrites63.5%

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

      \[\leadsto \color{blue}{\frac{1}{2} + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{1}{720} + \frac{-1}{40320} \cdot {x}^{2}\right) - \frac{1}{24}\right)} \]
    6. Applied rewrites70.6%

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

    if 0.096000000000000002 < x

    1. Initial program 97.4%

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

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

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

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

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

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

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

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

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

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

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

Alternative 4: 99.2% accurate, 1.0× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 0.096:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-2.48015873015873 \cdot 10^{-5}, x\_m \cdot x\_m, 0.001388888888888889\right), x\_m \cdot x\_m, -0.041666666666666664\right), x\_m \cdot x\_m, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1 - \cos x\_m}{x\_m \cdot x\_m}\\ \end{array} \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m)
 :precision binary64
 (if (<= x_m 0.096)
   (fma
    (fma
     (fma -2.48015873015873e-5 (* x_m x_m) 0.001388888888888889)
     (* x_m x_m)
     -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 <= 0.096) {
		tmp = fma(fma(fma(-2.48015873015873e-5, (x_m * x_m), 0.001388888888888889), (x_m * x_m), -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 <= 0.096)
		tmp = fma(fma(fma(-2.48015873015873e-5, Float64(x_m * x_m), 0.001388888888888889), Float64(x_m * x_m), -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, 0.096], N[(N[(N[(-2.48015873015873e-5 * N[(x$95$m * x$95$m), $MachinePrecision] + 0.001388888888888889), $MachinePrecision] * N[(x$95$m * x$95$m), $MachinePrecision] + -0.041666666666666664), $MachinePrecision] * 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 0.096:\\
\;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-2.48015873015873 \cdot 10^{-5}, x\_m \cdot x\_m, 0.001388888888888889\right), x\_m \cdot x\_m, -0.041666666666666664\right), 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 < 0.096000000000000002

    1. Initial program 32.3%

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

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

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

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

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

        \[\leadsto \frac{\color{blue}{\frac{1 \cdot 1 - \cos x \cdot \cos x}{1 + \cos x}}}{x \cdot x} \]
      6. pow2N/A

        \[\leadsto \frac{\frac{1 \cdot 1 - \cos x \cdot \cos x}{1 + \cos x}}{\color{blue}{{x}^{2}}} \]
      7. associate-/l/N/A

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

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

        \[\leadsto \frac{\color{blue}{1} - \cos x \cdot \cos x}{\left(1 + \cos x\right) \cdot {x}^{2}} \]
      10. 1-sub-cosN/A

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

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

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

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

        \[\leadsto \frac{\sin x \cdot \sin x}{\color{blue}{\left(1 + \cos x\right) \cdot {x}^{2}}} \]
      15. +-commutativeN/A

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

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

        \[\leadsto \frac{\sin x \cdot \sin x}{\left(\color{blue}{\cos x} + 1\right) \cdot {x}^{2}} \]
      18. pow2N/A

        \[\leadsto \frac{\sin x \cdot \sin x}{\left(\cos x + 1\right) \cdot \color{blue}{\left(x \cdot x\right)}} \]
      19. lift-*.f6463.5

        \[\leadsto \frac{\sin x \cdot \sin x}{\left(\cos x + 1\right) \cdot \color{blue}{\left(x \cdot x\right)}} \]
    4. Applied rewrites63.5%

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

      \[\leadsto \color{blue}{\frac{1}{2} + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{1}{720} + \frac{-1}{40320} \cdot {x}^{2}\right) - \frac{1}{24}\right)} \]
    6. Applied rewrites70.6%

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

    if 0.096000000000000002 < x

    1. Initial program 97.4%

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

Alternative 5: 76.4% accurate, 3.0× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 4.5:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-2.48015873015873 \cdot 10^{-5}, x\_m \cdot x\_m, 0.001388888888888889\right), x\_m \cdot x\_m, -0.041666666666666664\right), x\_m \cdot x\_m, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1 - 1}{x\_m \cdot x\_m}\\ \end{array} \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m)
 :precision binary64
 (if (<= x_m 4.5)
   (fma
    (fma
     (fma -2.48015873015873e-5 (* x_m x_m) 0.001388888888888889)
     (* x_m x_m)
     -0.041666666666666664)
    (* x_m x_m)
    0.5)
   (/ (- 1.0 1.0) (* x_m x_m))))
x_m = fabs(x);
double code(double x_m) {
	double tmp;
	if (x_m <= 4.5) {
		tmp = fma(fma(fma(-2.48015873015873e-5, (x_m * x_m), 0.001388888888888889), (x_m * x_m), -0.041666666666666664), (x_m * x_m), 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 <= 4.5)
		tmp = fma(fma(fma(-2.48015873015873e-5, Float64(x_m * x_m), 0.001388888888888889), Float64(x_m * x_m), -0.041666666666666664), Float64(x_m * x_m), 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, 4.5], N[(N[(N[(-2.48015873015873e-5 * N[(x$95$m * x$95$m), $MachinePrecision] + 0.001388888888888889), $MachinePrecision] * N[(x$95$m * x$95$m), $MachinePrecision] + -0.041666666666666664), $MachinePrecision] * N[(x$95$m * x$95$m), $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 4.5:\\
\;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-2.48015873015873 \cdot 10^{-5}, x\_m \cdot x\_m, 0.001388888888888889\right), x\_m \cdot x\_m, -0.041666666666666664\right), x\_m \cdot x\_m, 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 < 4.5

    1. Initial program 32.6%

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

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

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

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

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

        \[\leadsto \frac{\color{blue}{\frac{1 \cdot 1 - \cos x \cdot \cos x}{1 + \cos x}}}{x \cdot x} \]
      6. pow2N/A

        \[\leadsto \frac{\frac{1 \cdot 1 - \cos x \cdot \cos x}{1 + \cos x}}{\color{blue}{{x}^{2}}} \]
      7. associate-/l/N/A

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

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

        \[\leadsto \frac{\color{blue}{1} - \cos x \cdot \cos x}{\left(1 + \cos x\right) \cdot {x}^{2}} \]
      10. 1-sub-cosN/A

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

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

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

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

        \[\leadsto \frac{\sin x \cdot \sin x}{\color{blue}{\left(1 + \cos x\right) \cdot {x}^{2}}} \]
      15. +-commutativeN/A

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

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

        \[\leadsto \frac{\sin x \cdot \sin x}{\left(\color{blue}{\cos x} + 1\right) \cdot {x}^{2}} \]
      18. pow2N/A

        \[\leadsto \frac{\sin x \cdot \sin x}{\left(\cos x + 1\right) \cdot \color{blue}{\left(x \cdot x\right)}} \]
      19. lift-*.f6463.7

        \[\leadsto \frac{\sin x \cdot \sin x}{\left(\cos x + 1\right) \cdot \color{blue}{\left(x \cdot x\right)}} \]
    4. Applied rewrites63.7%

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

      \[\leadsto \color{blue}{\frac{1}{2} + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{1}{720} + \frac{-1}{40320} \cdot {x}^{2}\right) - \frac{1}{24}\right)} \]
    6. Applied rewrites70.6%

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

    if 4.5 < x

    1. Initial program 97.4%

      \[\frac{1 - \cos x}{x \cdot x} \]
    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 6: 76.5% accurate, 4.1× speedup?

    \[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 5 \cdot 10^{+38}:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(x\_m \cdot x\_m, 0.001388888888888889, -0.041666666666666664\right) \cdot x\_m, x\_m, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1 - 1}{x\_m \cdot x\_m}\\ \end{array} \end{array} \]
    x_m = (fabs.f64 x)
    (FPCore (x_m)
     :precision binary64
     (if (<= x_m 5e+38)
       (fma
        (* (fma (* x_m x_m) 0.001388888888888889 -0.041666666666666664) x_m)
        x_m
        0.5)
       (/ (- 1.0 1.0) (* x_m x_m))))
    x_m = fabs(x);
    double code(double x_m) {
    	double tmp;
    	if (x_m <= 5e+38) {
    		tmp = fma((fma((x_m * x_m), 0.001388888888888889, -0.041666666666666664) * x_m), x_m, 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 <= 5e+38)
    		tmp = fma(Float64(fma(Float64(x_m * x_m), 0.001388888888888889, -0.041666666666666664) * x_m), x_m, 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, 5e+38], N[(N[(N[(N[(x$95$m * x$95$m), $MachinePrecision] * 0.001388888888888889 + -0.041666666666666664), $MachinePrecision] * x$95$m), $MachinePrecision] * x$95$m + 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 5 \cdot 10^{+38}:\\
    \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(x\_m \cdot x\_m, 0.001388888888888889, -0.041666666666666664\right) \cdot x\_m, x\_m, 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 < 4.9999999999999997e38

      1. Initial program 33.9%

        \[\frac{1 - \cos x}{x \cdot x} \]
      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

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

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

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

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

          \[\leadsto \mathsf{fma}\left(\frac{1}{720} \cdot {x}^{2} - \frac{1}{24}, {x}^{2}, \frac{1}{2}\right) \]
        6. pow2N/A

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

          \[\leadsto \mathsf{fma}\left(\frac{1}{720} \cdot \left(x \cdot x\right) - \frac{1}{24}, {x}^{2}, \frac{1}{2}\right) \]
        8. pow2N/A

          \[\leadsto \mathsf{fma}\left(\frac{1}{720} \cdot \left(x \cdot x\right) - \frac{1}{24}, x \cdot \color{blue}{x}, \frac{1}{2}\right) \]
        9. lift-*.f6469.3

          \[\leadsto \mathsf{fma}\left(0.001388888888888889 \cdot \left(x \cdot x\right) - 0.041666666666666664, x \cdot \color{blue}{x}, 0.5\right) \]
      5. Applied rewrites69.3%

        \[\leadsto \color{blue}{\mathsf{fma}\left(0.001388888888888889 \cdot \left(x \cdot x\right) - 0.041666666666666664, x \cdot x, 0.5\right)} \]
      6. Step-by-step derivation
        1. Applied rewrites69.3%

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

        if 4.9999999999999997e38 < x

        1. Initial program 97.5%

          \[\frac{1 - \cos x}{x \cdot x} \]
        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 rewrites59.5%

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

        Alternative 7: 76.2% accurate, 4.6× speedup?

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

          1. Initial program 32.6%

            \[\frac{1 - \cos x}{x \cdot x} \]
          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

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

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

              \[\leadsto \mathsf{fma}\left({x}^{2}, \color{blue}{\frac{-1}{24}}, \frac{1}{2}\right) \]
            4. pow2N/A

              \[\leadsto \mathsf{fma}\left(x \cdot x, \frac{-1}{24}, \frac{1}{2}\right) \]
            5. lift-*.f6470.0

              \[\leadsto \mathsf{fma}\left(x \cdot x, -0.041666666666666664, 0.5\right) \]
          5. Applied rewrites70.0%

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

          if 3.5 < x

          1. Initial program 97.4%

            \[\frac{1 - \cos x}{x \cdot x} \]
          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. Final simplification66.5%

            \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 3.5:\\ \;\;\;\;\mathsf{fma}\left(x \cdot x, -0.041666666666666664, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1 - 1}{x \cdot x}\\ \end{array} \]
          7. Add Preprocessing

          Alternative 8: 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 =     private
          module fmin_fmax_functions
              implicit none
              private
              public fmax
              public fmin
          
              interface fmax
                  module procedure fmax88
                  module procedure fmax44
                  module procedure fmax84
                  module procedure fmax48
              end interface
              interface fmin
                  module procedure fmin88
                  module procedure fmin44
                  module procedure fmin84
                  module procedure fmin48
              end interface
          contains
              real(8) function fmax88(x, y) result (res)
                  real(8), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
              end function
              real(4) function fmax44(x, y) result (res)
                  real(4), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
              end function
              real(8) function fmax84(x, y) result(res)
                  real(8), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
              end function
              real(8) function fmax48(x, y) result(res)
                  real(4), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
              end function
              real(8) function fmin88(x, y) result (res)
                  real(8), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
              end function
              real(4) function fmin44(x, y) result (res)
                  real(4), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
              end function
              real(8) function fmin84(x, y) result(res)
                  real(8), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
              end function
              real(8) function fmin48(x, y) result(res)
                  real(4), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
              end function
          end module
          
          real(8) function code(x_m)
          use fmin_fmax_functions
              real(8), intent (in) :: x_m
              code = 0.5d0
          end function
          
          x_m = Math.abs(x);
          public static double code(double x_m) {
          	return 0.5;
          }
          
          x_m = math.fabs(x)
          def code(x_m):
          	return 0.5
          
          x_m = abs(x)
          function code(x_m)
          	return 0.5
          end
          
          x_m = abs(x);
          function tmp = code(x_m)
          	tmp = 0.5;
          end
          
          x_m = N[Abs[x], $MachinePrecision]
          code[x$95$m_] := 0.5
          
          \begin{array}{l}
          x_m = \left|x\right|
          
          \\
          0.5
          \end{array}
          
          Derivation
          1. Initial program 49.1%

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

            \[\leadsto \color{blue}{\frac{1}{2}} \]
          4. Step-by-step derivation
            1. Applied rewrites53.4%

              \[\leadsto \color{blue}{0.5} \]
            2. Final simplification53.4%

              \[\leadsto 0.5 \]
            3. Add Preprocessing

            Reproduce

            ?
            herbie shell --seed 2025083 
            (FPCore (x)
              :name "cos2 (problem 3.4.1)"
              :precision binary64
              (/ (- 1.0 (cos x)) (* x x)))