2cos (problem 3.3.5)

Percentage Accurate: 38.0% → 99.1%
Time: 16.6s
Alternatives: 14
Speedup: 1.8×

Specification

?
\[\begin{array}{l} \\ \cos \left(x + \varepsilon\right) - \cos x \end{array} \]
(FPCore (x eps) :precision binary64 (- (cos (+ x eps)) (cos x)))
double code(double x, double eps) {
	return cos((x + eps)) - cos(x);
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = cos((x + eps)) - cos(x)
end function
public static double code(double x, double eps) {
	return Math.cos((x + eps)) - Math.cos(x);
}
def code(x, eps):
	return math.cos((x + eps)) - math.cos(x)
function code(x, eps)
	return Float64(cos(Float64(x + eps)) - cos(x))
end
function tmp = code(x, eps)
	tmp = cos((x + eps)) - cos(x);
end
code[x_, eps_] := N[(N[Cos[N[(x + eps), $MachinePrecision]], $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\cos \left(x + \varepsilon\right) - \cos 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 14 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: 38.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \cos \left(x + \varepsilon\right) - \cos x \end{array} \]
(FPCore (x eps) :precision binary64 (- (cos (+ x eps)) (cos x)))
double code(double x, double eps) {
	return cos((x + eps)) - cos(x);
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = cos((x + eps)) - cos(x)
end function
public static double code(double x, double eps) {
	return Math.cos((x + eps)) - Math.cos(x);
}
def code(x, eps):
	return math.cos((x + eps)) - math.cos(x)
function code(x, eps)
	return Float64(cos(Float64(x + eps)) - cos(x))
end
function tmp = code(x, eps)
	tmp = cos((x + eps)) - cos(x);
end
code[x_, eps_] := N[(N[Cos[N[(x + eps), $MachinePrecision]], $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\cos \left(x + \varepsilon\right) - \cos x
\end{array}

Alternative 1: 99.1% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.000175 \lor \neg \left(\varepsilon \leq 0.00019\right):\\ \;\;\;\;\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\cos x\right) - \sin x \cdot \sin \varepsilon\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\sin x \cdot \left(-0.125 \cdot {\varepsilon}^{2} + 1\right) + \cos x \cdot \left(\varepsilon \cdot 0.5\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (or (<= eps -0.000175) (not (<= eps 0.00019)))
   (fma (cos x) (cos eps) (- (- (cos x)) (* (sin x) (sin eps))))
   (*
    (+ (* (sin x) (+ (* -0.125 (pow eps 2.0)) 1.0)) (* (cos x) (* eps 0.5)))
    (* -2.0 (sin (* eps 0.5))))))
double code(double x, double eps) {
	double tmp;
	if ((eps <= -0.000175) || !(eps <= 0.00019)) {
		tmp = fma(cos(x), cos(eps), (-cos(x) - (sin(x) * sin(eps))));
	} else {
		tmp = ((sin(x) * ((-0.125 * pow(eps, 2.0)) + 1.0)) + (cos(x) * (eps * 0.5))) * (-2.0 * sin((eps * 0.5)));
	}
	return tmp;
}
function code(x, eps)
	tmp = 0.0
	if ((eps <= -0.000175) || !(eps <= 0.00019))
		tmp = fma(cos(x), cos(eps), Float64(Float64(-cos(x)) - Float64(sin(x) * sin(eps))));
	else
		tmp = Float64(Float64(Float64(sin(x) * Float64(Float64(-0.125 * (eps ^ 2.0)) + 1.0)) + Float64(cos(x) * Float64(eps * 0.5))) * Float64(-2.0 * sin(Float64(eps * 0.5))));
	end
	return tmp
end
code[x_, eps_] := If[Or[LessEqual[eps, -0.000175], N[Not[LessEqual[eps, 0.00019]], $MachinePrecision]], N[(N[Cos[x], $MachinePrecision] * N[Cos[eps], $MachinePrecision] + N[((-N[Cos[x], $MachinePrecision]) - N[(N[Sin[x], $MachinePrecision] * N[Sin[eps], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[Sin[x], $MachinePrecision] * N[(N[(-0.125 * N[Power[eps, 2.0], $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision] + N[(N[Cos[x], $MachinePrecision] * N[(eps * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(-2.0 * N[Sin[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\varepsilon \leq -0.000175 \lor \neg \left(\varepsilon \leq 0.00019\right):\\
\;\;\;\;\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\cos x\right) - \sin x \cdot \sin \varepsilon\right)\\

\mathbf{else}:\\
\;\;\;\;\left(\sin x \cdot \left(-0.125 \cdot {\varepsilon}^{2} + 1\right) + \cos x \cdot \left(\varepsilon \cdot 0.5\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if eps < -1.74999999999999998e-4 or 1.9000000000000001e-4 < eps

    1. Initial program 59.7%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. sub-neg59.7%

        \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right) + \left(-\cos x\right)} \]
      2. cos-sum98.3%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} + \left(-\cos x\right) \]
      3. associate-+l-98.4%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right)} \]
      4. fma-neg98.4%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, -\left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right)\right)} \]
    4. Applied egg-rr98.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, -\left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right)\right)} \]
    5. Step-by-step derivation
      1. sub-neg98.4%

        \[\leadsto \mathsf{fma}\left(\cos x, \cos \varepsilon, -\color{blue}{\left(\sin x \cdot \sin \varepsilon + \left(-\left(-\cos x\right)\right)\right)}\right) \]
      2. remove-double-neg98.4%

        \[\leadsto \mathsf{fma}\left(\cos x, \cos \varepsilon, -\left(\sin x \cdot \sin \varepsilon + \color{blue}{\cos x}\right)\right) \]
    6. Applied egg-rr98.4%

      \[\leadsto \mathsf{fma}\left(\cos x, \cos \varepsilon, -\color{blue}{\left(\sin x \cdot \sin \varepsilon + \cos x\right)}\right) \]

    if -1.74999999999999998e-4 < eps < 1.9000000000000001e-4

    1. Initial program 26.3%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. diff-cos42.0%

        \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
      2. div-inv42.0%

        \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      3. associate--l+42.0%

        \[\leadsto -2 \cdot \left(\sin \left(\color{blue}{\left(x + \left(\varepsilon - x\right)\right)} \cdot \frac{1}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      4. metadata-eval42.0%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot \color{blue}{0.5}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      5. div-inv42.0%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
      6. +-commutative42.0%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\color{blue}{\left(\varepsilon + x\right)} + x\right) \cdot \frac{1}{2}\right)\right) \]
      7. associate-+l+42.0%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\color{blue}{\left(\varepsilon + \left(x + x\right)\right)} \cdot \frac{1}{2}\right)\right) \]
      8. metadata-eval42.0%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
    4. Applied egg-rr42.0%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)\right)} \]
    5. Step-by-step derivation
      1. associate-*r*42.0%

        \[\leadsto \color{blue}{\left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)} \]
      2. *-commutative42.0%

        \[\leadsto \color{blue}{\sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right)} \]
      3. *-commutative42.0%

        \[\leadsto \sin \color{blue}{\left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)} \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      4. +-commutative42.0%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      5. count-242.0%

        \[\leadsto \sin \left(0.5 \cdot \left(\color{blue}{2 \cdot x} + \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      6. fma-def42.0%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\mathsf{fma}\left(2, x, \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      7. sub-neg42.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(\varepsilon + \left(-x\right)\right)}\right) \cdot 0.5\right)\right) \]
      8. mul-1-neg42.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon + \color{blue}{-1 \cdot x}\right)\right) \cdot 0.5\right)\right) \]
      9. +-commutative42.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(-1 \cdot x + \varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      10. associate-+r+99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(\left(x + -1 \cdot x\right) + \varepsilon\right)} \cdot 0.5\right)\right) \]
      11. mul-1-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\left(x + \color{blue}{\left(-x\right)}\right) + \varepsilon\right) \cdot 0.5\right)\right) \]
      12. sub-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{\left(x - x\right)} + \varepsilon\right) \cdot 0.5\right)\right) \]
      13. +-inverses99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{0} + \varepsilon\right) \cdot 0.5\right)\right) \]
      14. remove-double-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \color{blue}{\left(-\left(-\varepsilon\right)\right)}\right) \cdot 0.5\right)\right) \]
      15. mul-1-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \left(-\color{blue}{-1 \cdot \varepsilon}\right)\right) \cdot 0.5\right)\right) \]
      16. sub-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(0 - -1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      17. neg-sub099.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(--1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      18. mul-1-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(-\color{blue}{\left(-\varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      19. remove-double-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\varepsilon} \cdot 0.5\right)\right) \]
    6. Simplified99.2%

      \[\leadsto \color{blue}{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)} \]
    7. Taylor expanded in eps around 0 99.8%

      \[\leadsto \color{blue}{\left(\sin x + \left(-0.125 \cdot \left({\varepsilon}^{2} \cdot \sin x\right) + 0.5 \cdot \left(\varepsilon \cdot \cos x\right)\right)\right)} \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
    8. Step-by-step derivation
      1. associate-+r+99.8%

        \[\leadsto \color{blue}{\left(\left(\sin x + -0.125 \cdot \left({\varepsilon}^{2} \cdot \sin x\right)\right) + 0.5 \cdot \left(\varepsilon \cdot \cos x\right)\right)} \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
      2. associate-*r*99.8%

        \[\leadsto \left(\left(\sin x + \color{blue}{\left(-0.125 \cdot {\varepsilon}^{2}\right) \cdot \sin x}\right) + 0.5 \cdot \left(\varepsilon \cdot \cos x\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
      3. distribute-rgt1-in99.8%

        \[\leadsto \left(\color{blue}{\left(-0.125 \cdot {\varepsilon}^{2} + 1\right) \cdot \sin x} + 0.5 \cdot \left(\varepsilon \cdot \cos x\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
      4. associate-*r*99.8%

        \[\leadsto \left(\left(-0.125 \cdot {\varepsilon}^{2} + 1\right) \cdot \sin x + \color{blue}{\left(0.5 \cdot \varepsilon\right) \cdot \cos x}\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
    9. Simplified99.8%

      \[\leadsto \color{blue}{\left(\left(-0.125 \cdot {\varepsilon}^{2} + 1\right) \cdot \sin x + \left(0.5 \cdot \varepsilon\right) \cdot \cos x\right)} \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.000175 \lor \neg \left(\varepsilon \leq 0.00019\right):\\ \;\;\;\;\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\cos x\right) - \sin x \cdot \sin \varepsilon\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\sin x \cdot \left(-0.125 \cdot {\varepsilon}^{2} + 1\right) + \cos x \cdot \left(\varepsilon \cdot 0.5\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 99.1% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.00021:\\ \;\;\;\;\cos x \cdot \cos \varepsilon - \left(\cos x + \sin x \cdot \sin \varepsilon\right)\\ \mathbf{elif}\;\varepsilon \leq 0.00018:\\ \;\;\;\;\left(\sin x \cdot \left(-0.125 \cdot {\varepsilon}^{2} + 1\right) + \cos x \cdot \left(\varepsilon \cdot 0.5\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\cos x, \cos \varepsilon, \sin x \cdot \left(-\sin \varepsilon\right)\right) - \cos x\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (<= eps -0.00021)
   (- (* (cos x) (cos eps)) (+ (cos x) (* (sin x) (sin eps))))
   (if (<= eps 0.00018)
     (*
      (+ (* (sin x) (+ (* -0.125 (pow eps 2.0)) 1.0)) (* (cos x) (* eps 0.5)))
      (* -2.0 (sin (* eps 0.5))))
     (- (fma (cos x) (cos eps) (* (sin x) (- (sin eps)))) (cos x)))))
double code(double x, double eps) {
	double tmp;
	if (eps <= -0.00021) {
		tmp = (cos(x) * cos(eps)) - (cos(x) + (sin(x) * sin(eps)));
	} else if (eps <= 0.00018) {
		tmp = ((sin(x) * ((-0.125 * pow(eps, 2.0)) + 1.0)) + (cos(x) * (eps * 0.5))) * (-2.0 * sin((eps * 0.5)));
	} else {
		tmp = fma(cos(x), cos(eps), (sin(x) * -sin(eps))) - cos(x);
	}
	return tmp;
}
function code(x, eps)
	tmp = 0.0
	if (eps <= -0.00021)
		tmp = Float64(Float64(cos(x) * cos(eps)) - Float64(cos(x) + Float64(sin(x) * sin(eps))));
	elseif (eps <= 0.00018)
		tmp = Float64(Float64(Float64(sin(x) * Float64(Float64(-0.125 * (eps ^ 2.0)) + 1.0)) + Float64(cos(x) * Float64(eps * 0.5))) * Float64(-2.0 * sin(Float64(eps * 0.5))));
	else
		tmp = Float64(fma(cos(x), cos(eps), Float64(sin(x) * Float64(-sin(eps)))) - cos(x));
	end
	return tmp
end
code[x_, eps_] := If[LessEqual[eps, -0.00021], N[(N[(N[Cos[x], $MachinePrecision] * N[Cos[eps], $MachinePrecision]), $MachinePrecision] - N[(N[Cos[x], $MachinePrecision] + N[(N[Sin[x], $MachinePrecision] * N[Sin[eps], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[eps, 0.00018], N[(N[(N[(N[Sin[x], $MachinePrecision] * N[(N[(-0.125 * N[Power[eps, 2.0], $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision] + N[(N[Cos[x], $MachinePrecision] * N[(eps * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(-2.0 * N[Sin[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[Cos[x], $MachinePrecision] * N[Cos[eps], $MachinePrecision] + N[(N[Sin[x], $MachinePrecision] * (-N[Sin[eps], $MachinePrecision])), $MachinePrecision]), $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\varepsilon \leq -0.00021:\\
\;\;\;\;\cos x \cdot \cos \varepsilon - \left(\cos x + \sin x \cdot \sin \varepsilon\right)\\

\mathbf{elif}\;\varepsilon \leq 0.00018:\\
\;\;\;\;\left(\sin x \cdot \left(-0.125 \cdot {\varepsilon}^{2} + 1\right) + \cos x \cdot \left(\varepsilon \cdot 0.5\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\cos x, \cos \varepsilon, \sin x \cdot \left(-\sin \varepsilon\right)\right) - \cos x\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if eps < -2.1000000000000001e-4

    1. Initial program 56.1%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. sub-neg56.1%

        \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right) + \left(-\cos x\right)} \]
      2. cos-sum98.0%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} + \left(-\cos x\right) \]
      3. associate-+l-98.1%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right)} \]
      4. fma-neg98.2%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, -\left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right)\right)} \]
    4. Applied egg-rr98.2%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, -\left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right)\right)} \]
    5. Taylor expanded in x around inf 98.1%

      \[\leadsto \color{blue}{\cos \varepsilon \cdot \cos x - \left(\cos x + \sin \varepsilon \cdot \sin x\right)} \]

    if -2.1000000000000001e-4 < eps < 1.80000000000000011e-4

    1. Initial program 26.3%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. diff-cos42.0%

        \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
      2. div-inv42.0%

        \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      3. associate--l+42.0%

        \[\leadsto -2 \cdot \left(\sin \left(\color{blue}{\left(x + \left(\varepsilon - x\right)\right)} \cdot \frac{1}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      4. metadata-eval42.0%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot \color{blue}{0.5}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      5. div-inv42.0%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
      6. +-commutative42.0%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\color{blue}{\left(\varepsilon + x\right)} + x\right) \cdot \frac{1}{2}\right)\right) \]
      7. associate-+l+42.0%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\color{blue}{\left(\varepsilon + \left(x + x\right)\right)} \cdot \frac{1}{2}\right)\right) \]
      8. metadata-eval42.0%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
    4. Applied egg-rr42.0%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)\right)} \]
    5. Step-by-step derivation
      1. associate-*r*42.0%

        \[\leadsto \color{blue}{\left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)} \]
      2. *-commutative42.0%

        \[\leadsto \color{blue}{\sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right)} \]
      3. *-commutative42.0%

        \[\leadsto \sin \color{blue}{\left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)} \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      4. +-commutative42.0%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      5. count-242.0%

        \[\leadsto \sin \left(0.5 \cdot \left(\color{blue}{2 \cdot x} + \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      6. fma-def42.0%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\mathsf{fma}\left(2, x, \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      7. sub-neg42.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(\varepsilon + \left(-x\right)\right)}\right) \cdot 0.5\right)\right) \]
      8. mul-1-neg42.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon + \color{blue}{-1 \cdot x}\right)\right) \cdot 0.5\right)\right) \]
      9. +-commutative42.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(-1 \cdot x + \varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      10. associate-+r+99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(\left(x + -1 \cdot x\right) + \varepsilon\right)} \cdot 0.5\right)\right) \]
      11. mul-1-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\left(x + \color{blue}{\left(-x\right)}\right) + \varepsilon\right) \cdot 0.5\right)\right) \]
      12. sub-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{\left(x - x\right)} + \varepsilon\right) \cdot 0.5\right)\right) \]
      13. +-inverses99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{0} + \varepsilon\right) \cdot 0.5\right)\right) \]
      14. remove-double-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \color{blue}{\left(-\left(-\varepsilon\right)\right)}\right) \cdot 0.5\right)\right) \]
      15. mul-1-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \left(-\color{blue}{-1 \cdot \varepsilon}\right)\right) \cdot 0.5\right)\right) \]
      16. sub-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(0 - -1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      17. neg-sub099.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(--1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      18. mul-1-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(-\color{blue}{\left(-\varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      19. remove-double-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\varepsilon} \cdot 0.5\right)\right) \]
    6. Simplified99.2%

      \[\leadsto \color{blue}{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)} \]
    7. Taylor expanded in eps around 0 99.8%

      \[\leadsto \color{blue}{\left(\sin x + \left(-0.125 \cdot \left({\varepsilon}^{2} \cdot \sin x\right) + 0.5 \cdot \left(\varepsilon \cdot \cos x\right)\right)\right)} \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
    8. Step-by-step derivation
      1. associate-+r+99.8%

        \[\leadsto \color{blue}{\left(\left(\sin x + -0.125 \cdot \left({\varepsilon}^{2} \cdot \sin x\right)\right) + 0.5 \cdot \left(\varepsilon \cdot \cos x\right)\right)} \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
      2. associate-*r*99.8%

        \[\leadsto \left(\left(\sin x + \color{blue}{\left(-0.125 \cdot {\varepsilon}^{2}\right) \cdot \sin x}\right) + 0.5 \cdot \left(\varepsilon \cdot \cos x\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
      3. distribute-rgt1-in99.8%

        \[\leadsto \left(\color{blue}{\left(-0.125 \cdot {\varepsilon}^{2} + 1\right) \cdot \sin x} + 0.5 \cdot \left(\varepsilon \cdot \cos x\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
      4. associate-*r*99.8%

        \[\leadsto \left(\left(-0.125 \cdot {\varepsilon}^{2} + 1\right) \cdot \sin x + \color{blue}{\left(0.5 \cdot \varepsilon\right) \cdot \cos x}\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
    9. Simplified99.8%

      \[\leadsto \color{blue}{\left(\left(-0.125 \cdot {\varepsilon}^{2} + 1\right) \cdot \sin x + \left(0.5 \cdot \varepsilon\right) \cdot \cos x\right)} \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]

    if 1.80000000000000011e-4 < eps

    1. Initial program 63.1%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. cos-sum98.7%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \]
      2. cancel-sign-sub-inv98.7%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon + \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
      3. fma-def98.7%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
    4. Applied egg-rr98.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, \left(-\sin x\right) \cdot \sin \varepsilon\right)} - \cos x \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.00021:\\ \;\;\;\;\cos x \cdot \cos \varepsilon - \left(\cos x + \sin x \cdot \sin \varepsilon\right)\\ \mathbf{elif}\;\varepsilon \leq 0.00018:\\ \;\;\;\;\left(\sin x \cdot \left(-0.125 \cdot {\varepsilon}^{2} + 1\right) + \cos x \cdot \left(\varepsilon \cdot 0.5\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\cos x, \cos \varepsilon, \sin x \cdot \left(-\sin \varepsilon\right)\right) - \cos x\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 99.1% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.00021 \lor \neg \left(\varepsilon \leq 0.000195\right):\\ \;\;\;\;\cos x \cdot \cos \varepsilon - \left(\cos x + \sin x \cdot \sin \varepsilon\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\sin x \cdot \left(-0.125 \cdot {\varepsilon}^{2} + 1\right) + \cos x \cdot \left(\varepsilon \cdot 0.5\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (or (<= eps -0.00021) (not (<= eps 0.000195)))
   (- (* (cos x) (cos eps)) (+ (cos x) (* (sin x) (sin eps))))
   (*
    (+ (* (sin x) (+ (* -0.125 (pow eps 2.0)) 1.0)) (* (cos x) (* eps 0.5)))
    (* -2.0 (sin (* eps 0.5))))))
double code(double x, double eps) {
	double tmp;
	if ((eps <= -0.00021) || !(eps <= 0.000195)) {
		tmp = (cos(x) * cos(eps)) - (cos(x) + (sin(x) * sin(eps)));
	} else {
		tmp = ((sin(x) * ((-0.125 * pow(eps, 2.0)) + 1.0)) + (cos(x) * (eps * 0.5))) * (-2.0 * sin((eps * 0.5)));
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if ((eps <= (-0.00021d0)) .or. (.not. (eps <= 0.000195d0))) then
        tmp = (cos(x) * cos(eps)) - (cos(x) + (sin(x) * sin(eps)))
    else
        tmp = ((sin(x) * (((-0.125d0) * (eps ** 2.0d0)) + 1.0d0)) + (cos(x) * (eps * 0.5d0))) * ((-2.0d0) * sin((eps * 0.5d0)))
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if ((eps <= -0.00021) || !(eps <= 0.000195)) {
		tmp = (Math.cos(x) * Math.cos(eps)) - (Math.cos(x) + (Math.sin(x) * Math.sin(eps)));
	} else {
		tmp = ((Math.sin(x) * ((-0.125 * Math.pow(eps, 2.0)) + 1.0)) + (Math.cos(x) * (eps * 0.5))) * (-2.0 * Math.sin((eps * 0.5)));
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if (eps <= -0.00021) or not (eps <= 0.000195):
		tmp = (math.cos(x) * math.cos(eps)) - (math.cos(x) + (math.sin(x) * math.sin(eps)))
	else:
		tmp = ((math.sin(x) * ((-0.125 * math.pow(eps, 2.0)) + 1.0)) + (math.cos(x) * (eps * 0.5))) * (-2.0 * math.sin((eps * 0.5)))
	return tmp
function code(x, eps)
	tmp = 0.0
	if ((eps <= -0.00021) || !(eps <= 0.000195))
		tmp = Float64(Float64(cos(x) * cos(eps)) - Float64(cos(x) + Float64(sin(x) * sin(eps))));
	else
		tmp = Float64(Float64(Float64(sin(x) * Float64(Float64(-0.125 * (eps ^ 2.0)) + 1.0)) + Float64(cos(x) * Float64(eps * 0.5))) * Float64(-2.0 * sin(Float64(eps * 0.5))));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if ((eps <= -0.00021) || ~((eps <= 0.000195)))
		tmp = (cos(x) * cos(eps)) - (cos(x) + (sin(x) * sin(eps)));
	else
		tmp = ((sin(x) * ((-0.125 * (eps ^ 2.0)) + 1.0)) + (cos(x) * (eps * 0.5))) * (-2.0 * sin((eps * 0.5)));
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[Or[LessEqual[eps, -0.00021], N[Not[LessEqual[eps, 0.000195]], $MachinePrecision]], N[(N[(N[Cos[x], $MachinePrecision] * N[Cos[eps], $MachinePrecision]), $MachinePrecision] - N[(N[Cos[x], $MachinePrecision] + N[(N[Sin[x], $MachinePrecision] * N[Sin[eps], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[Sin[x], $MachinePrecision] * N[(N[(-0.125 * N[Power[eps, 2.0], $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision] + N[(N[Cos[x], $MachinePrecision] * N[(eps * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(-2.0 * N[Sin[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\varepsilon \leq -0.00021 \lor \neg \left(\varepsilon \leq 0.000195\right):\\
\;\;\;\;\cos x \cdot \cos \varepsilon - \left(\cos x + \sin x \cdot \sin \varepsilon\right)\\

\mathbf{else}:\\
\;\;\;\;\left(\sin x \cdot \left(-0.125 \cdot {\varepsilon}^{2} + 1\right) + \cos x \cdot \left(\varepsilon \cdot 0.5\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if eps < -2.1000000000000001e-4 or 1.94999999999999996e-4 < eps

    1. Initial program 59.7%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. sub-neg59.7%

        \[\leadsto \color{blue}{\cos \left(x + \varepsilon\right) + \left(-\cos x\right)} \]
      2. cos-sum98.3%

        \[\leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} + \left(-\cos x\right) \]
      3. associate-+l-98.4%

        \[\leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right)} \]
      4. fma-neg98.4%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, -\left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right)\right)} \]
    4. Applied egg-rr98.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\cos x, \cos \varepsilon, -\left(\sin x \cdot \sin \varepsilon - \left(-\cos x\right)\right)\right)} \]
    5. Taylor expanded in x around inf 98.4%

      \[\leadsto \color{blue}{\cos \varepsilon \cdot \cos x - \left(\cos x + \sin \varepsilon \cdot \sin x\right)} \]

    if -2.1000000000000001e-4 < eps < 1.94999999999999996e-4

    1. Initial program 26.3%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. diff-cos42.0%

        \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
      2. div-inv42.0%

        \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      3. associate--l+42.0%

        \[\leadsto -2 \cdot \left(\sin \left(\color{blue}{\left(x + \left(\varepsilon - x\right)\right)} \cdot \frac{1}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      4. metadata-eval42.0%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot \color{blue}{0.5}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      5. div-inv42.0%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
      6. +-commutative42.0%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\color{blue}{\left(\varepsilon + x\right)} + x\right) \cdot \frac{1}{2}\right)\right) \]
      7. associate-+l+42.0%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\color{blue}{\left(\varepsilon + \left(x + x\right)\right)} \cdot \frac{1}{2}\right)\right) \]
      8. metadata-eval42.0%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
    4. Applied egg-rr42.0%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)\right)} \]
    5. Step-by-step derivation
      1. associate-*r*42.0%

        \[\leadsto \color{blue}{\left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)} \]
      2. *-commutative42.0%

        \[\leadsto \color{blue}{\sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right)} \]
      3. *-commutative42.0%

        \[\leadsto \sin \color{blue}{\left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)} \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      4. +-commutative42.0%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      5. count-242.0%

        \[\leadsto \sin \left(0.5 \cdot \left(\color{blue}{2 \cdot x} + \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      6. fma-def42.0%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\mathsf{fma}\left(2, x, \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      7. sub-neg42.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(\varepsilon + \left(-x\right)\right)}\right) \cdot 0.5\right)\right) \]
      8. mul-1-neg42.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon + \color{blue}{-1 \cdot x}\right)\right) \cdot 0.5\right)\right) \]
      9. +-commutative42.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(-1 \cdot x + \varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      10. associate-+r+99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(\left(x + -1 \cdot x\right) + \varepsilon\right)} \cdot 0.5\right)\right) \]
      11. mul-1-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\left(x + \color{blue}{\left(-x\right)}\right) + \varepsilon\right) \cdot 0.5\right)\right) \]
      12. sub-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{\left(x - x\right)} + \varepsilon\right) \cdot 0.5\right)\right) \]
      13. +-inverses99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{0} + \varepsilon\right) \cdot 0.5\right)\right) \]
      14. remove-double-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \color{blue}{\left(-\left(-\varepsilon\right)\right)}\right) \cdot 0.5\right)\right) \]
      15. mul-1-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \left(-\color{blue}{-1 \cdot \varepsilon}\right)\right) \cdot 0.5\right)\right) \]
      16. sub-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(0 - -1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      17. neg-sub099.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(--1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      18. mul-1-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(-\color{blue}{\left(-\varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      19. remove-double-neg99.2%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\varepsilon} \cdot 0.5\right)\right) \]
    6. Simplified99.2%

      \[\leadsto \color{blue}{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)} \]
    7. Taylor expanded in eps around 0 99.8%

      \[\leadsto \color{blue}{\left(\sin x + \left(-0.125 \cdot \left({\varepsilon}^{2} \cdot \sin x\right) + 0.5 \cdot \left(\varepsilon \cdot \cos x\right)\right)\right)} \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
    8. Step-by-step derivation
      1. associate-+r+99.8%

        \[\leadsto \color{blue}{\left(\left(\sin x + -0.125 \cdot \left({\varepsilon}^{2} \cdot \sin x\right)\right) + 0.5 \cdot \left(\varepsilon \cdot \cos x\right)\right)} \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
      2. associate-*r*99.8%

        \[\leadsto \left(\left(\sin x + \color{blue}{\left(-0.125 \cdot {\varepsilon}^{2}\right) \cdot \sin x}\right) + 0.5 \cdot \left(\varepsilon \cdot \cos x\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
      3. distribute-rgt1-in99.8%

        \[\leadsto \left(\color{blue}{\left(-0.125 \cdot {\varepsilon}^{2} + 1\right) \cdot \sin x} + 0.5 \cdot \left(\varepsilon \cdot \cos x\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
      4. associate-*r*99.8%

        \[\leadsto \left(\left(-0.125 \cdot {\varepsilon}^{2} + 1\right) \cdot \sin x + \color{blue}{\left(0.5 \cdot \varepsilon\right) \cdot \cos x}\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
    9. Simplified99.8%

      \[\leadsto \color{blue}{\left(\left(-0.125 \cdot {\varepsilon}^{2} + 1\right) \cdot \sin x + \left(0.5 \cdot \varepsilon\right) \cdot \cos x\right)} \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.00021 \lor \neg \left(\varepsilon \leq 0.000195\right):\\ \;\;\;\;\cos x \cdot \cos \varepsilon - \left(\cos x + \sin x \cdot \sin \varepsilon\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\sin x \cdot \left(-0.125 \cdot {\varepsilon}^{2} + 1\right) + \cos x \cdot \left(\varepsilon \cdot 0.5\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 75.4% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\cos \left(\varepsilon + x\right) - \cos x \leq -4 \cdot 10^{-5}:\\ \;\;\;\;-2 \cdot {\sin \left(\varepsilon \cdot 0.5\right)}^{2}\\ \mathbf{else}:\\ \;\;\;\;\cos x \cdot \left({\varepsilon}^{2} \cdot -0.5\right) - \varepsilon \cdot \sin x\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (<= (- (cos (+ eps x)) (cos x)) -4e-5)
   (* -2.0 (pow (sin (* eps 0.5)) 2.0))
   (- (* (cos x) (* (pow eps 2.0) -0.5)) (* eps (sin x)))))
double code(double x, double eps) {
	double tmp;
	if ((cos((eps + x)) - cos(x)) <= -4e-5) {
		tmp = -2.0 * pow(sin((eps * 0.5)), 2.0);
	} else {
		tmp = (cos(x) * (pow(eps, 2.0) * -0.5)) - (eps * sin(x));
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if ((cos((eps + x)) - cos(x)) <= (-4d-5)) then
        tmp = (-2.0d0) * (sin((eps * 0.5d0)) ** 2.0d0)
    else
        tmp = (cos(x) * ((eps ** 2.0d0) * (-0.5d0))) - (eps * sin(x))
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if ((Math.cos((eps + x)) - Math.cos(x)) <= -4e-5) {
		tmp = -2.0 * Math.pow(Math.sin((eps * 0.5)), 2.0);
	} else {
		tmp = (Math.cos(x) * (Math.pow(eps, 2.0) * -0.5)) - (eps * Math.sin(x));
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if (math.cos((eps + x)) - math.cos(x)) <= -4e-5:
		tmp = -2.0 * math.pow(math.sin((eps * 0.5)), 2.0)
	else:
		tmp = (math.cos(x) * (math.pow(eps, 2.0) * -0.5)) - (eps * math.sin(x))
	return tmp
function code(x, eps)
	tmp = 0.0
	if (Float64(cos(Float64(eps + x)) - cos(x)) <= -4e-5)
		tmp = Float64(-2.0 * (sin(Float64(eps * 0.5)) ^ 2.0));
	else
		tmp = Float64(Float64(cos(x) * Float64((eps ^ 2.0) * -0.5)) - Float64(eps * sin(x)));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if ((cos((eps + x)) - cos(x)) <= -4e-5)
		tmp = -2.0 * (sin((eps * 0.5)) ^ 2.0);
	else
		tmp = (cos(x) * ((eps ^ 2.0) * -0.5)) - (eps * sin(x));
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[LessEqual[N[(N[Cos[N[(eps + x), $MachinePrecision]], $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision], -4e-5], N[(-2.0 * N[Power[N[Sin[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision], N[(N[(N[Cos[x], $MachinePrecision] * N[(N[Power[eps, 2.0], $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision] - N[(eps * N[Sin[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\cos \left(\varepsilon + x\right) - \cos x \leq -4 \cdot 10^{-5}:\\
\;\;\;\;-2 \cdot {\sin \left(\varepsilon \cdot 0.5\right)}^{2}\\

\mathbf{else}:\\
\;\;\;\;\cos x \cdot \left({\varepsilon}^{2} \cdot -0.5\right) - \varepsilon \cdot \sin x\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (cos.f64 (+.f64 x eps)) (cos.f64 x)) < -4.00000000000000033e-5

    1. Initial program 83.8%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. diff-cos84.1%

        \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
      2. div-inv84.1%

        \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      3. associate--l+84.1%

        \[\leadsto -2 \cdot \left(\sin \left(\color{blue}{\left(x + \left(\varepsilon - x\right)\right)} \cdot \frac{1}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      4. metadata-eval84.1%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot \color{blue}{0.5}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      5. div-inv84.1%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
      6. +-commutative84.1%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\color{blue}{\left(\varepsilon + x\right)} + x\right) \cdot \frac{1}{2}\right)\right) \]
      7. associate-+l+84.1%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\color{blue}{\left(\varepsilon + \left(x + x\right)\right)} \cdot \frac{1}{2}\right)\right) \]
      8. metadata-eval84.1%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
    4. Applied egg-rr84.1%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)\right)} \]
    5. Step-by-step derivation
      1. associate-*r*84.1%

        \[\leadsto \color{blue}{\left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)} \]
      2. *-commutative84.1%

        \[\leadsto \color{blue}{\sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right)} \]
      3. *-commutative84.1%

        \[\leadsto \sin \color{blue}{\left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)} \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      4. +-commutative84.1%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      5. count-284.1%

        \[\leadsto \sin \left(0.5 \cdot \left(\color{blue}{2 \cdot x} + \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      6. fma-def84.1%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\mathsf{fma}\left(2, x, \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      7. sub-neg84.1%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(\varepsilon + \left(-x\right)\right)}\right) \cdot 0.5\right)\right) \]
      8. mul-1-neg84.1%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon + \color{blue}{-1 \cdot x}\right)\right) \cdot 0.5\right)\right) \]
      9. +-commutative84.1%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(-1 \cdot x + \varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      10. associate-+r+84.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(\left(x + -1 \cdot x\right) + \varepsilon\right)} \cdot 0.5\right)\right) \]
      11. mul-1-neg84.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\left(x + \color{blue}{\left(-x\right)}\right) + \varepsilon\right) \cdot 0.5\right)\right) \]
      12. sub-neg84.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{\left(x - x\right)} + \varepsilon\right) \cdot 0.5\right)\right) \]
      13. +-inverses84.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{0} + \varepsilon\right) \cdot 0.5\right)\right) \]
      14. remove-double-neg84.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \color{blue}{\left(-\left(-\varepsilon\right)\right)}\right) \cdot 0.5\right)\right) \]
      15. mul-1-neg84.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \left(-\color{blue}{-1 \cdot \varepsilon}\right)\right) \cdot 0.5\right)\right) \]
      16. sub-neg84.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(0 - -1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      17. neg-sub084.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(--1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      18. mul-1-neg84.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(-\color{blue}{\left(-\varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      19. remove-double-neg84.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\varepsilon} \cdot 0.5\right)\right) \]
    6. Simplified84.0%

      \[\leadsto \color{blue}{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)} \]
    7. Taylor expanded in x around 0 84.5%

      \[\leadsto \color{blue}{-2 \cdot {\sin \left(0.5 \cdot \varepsilon\right)}^{2}} \]

    if -4.00000000000000033e-5 < (-.f64 (cos.f64 (+.f64 x eps)) (cos.f64 x))

    1. Initial program 21.1%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in eps around 0 75.8%

      \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right) + -0.5 \cdot \left({\varepsilon}^{2} \cdot \cos x\right)} \]
    4. Step-by-step derivation
      1. +-commutative75.8%

        \[\leadsto \color{blue}{-0.5 \cdot \left({\varepsilon}^{2} \cdot \cos x\right) + -1 \cdot \left(\varepsilon \cdot \sin x\right)} \]
      2. mul-1-neg75.8%

        \[\leadsto -0.5 \cdot \left({\varepsilon}^{2} \cdot \cos x\right) + \color{blue}{\left(-\varepsilon \cdot \sin x\right)} \]
      3. unsub-neg75.8%

        \[\leadsto \color{blue}{-0.5 \cdot \left({\varepsilon}^{2} \cdot \cos x\right) - \varepsilon \cdot \sin x} \]
      4. associate-*r*75.8%

        \[\leadsto \color{blue}{\left(-0.5 \cdot {\varepsilon}^{2}\right) \cdot \cos x} - \varepsilon \cdot \sin x \]
      5. *-commutative75.8%

        \[\leadsto \color{blue}{\cos x \cdot \left(-0.5 \cdot {\varepsilon}^{2}\right)} - \varepsilon \cdot \sin x \]
    5. Simplified75.8%

      \[\leadsto \color{blue}{\cos x \cdot \left(-0.5 \cdot {\varepsilon}^{2}\right) - \varepsilon \cdot \sin x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification78.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\cos \left(\varepsilon + x\right) - \cos x \leq -4 \cdot 10^{-5}:\\ \;\;\;\;-2 \cdot {\sin \left(\varepsilon \cdot 0.5\right)}^{2}\\ \mathbf{else}:\\ \;\;\;\;\cos x \cdot \left({\varepsilon}^{2} \cdot -0.5\right) - \varepsilon \cdot \sin x\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 75.2% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\cos \left(\varepsilon + x\right) - \cos x \leq -4 \cdot 10^{-5}:\\ \;\;\;\;-2 \cdot {\sin \left(\varepsilon \cdot 0.5\right)}^{2}\\ \mathbf{else}:\\ \;\;\;\;\varepsilon \cdot \left(-\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)\right)\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (<= (- (cos (+ eps x)) (cos x)) -4e-5)
   (* -2.0 (pow (sin (* eps 0.5)) 2.0))
   (* eps (- (sin (* 0.5 (fma 2.0 x eps)))))))
double code(double x, double eps) {
	double tmp;
	if ((cos((eps + x)) - cos(x)) <= -4e-5) {
		tmp = -2.0 * pow(sin((eps * 0.5)), 2.0);
	} else {
		tmp = eps * -sin((0.5 * fma(2.0, x, eps)));
	}
	return tmp;
}
function code(x, eps)
	tmp = 0.0
	if (Float64(cos(Float64(eps + x)) - cos(x)) <= -4e-5)
		tmp = Float64(-2.0 * (sin(Float64(eps * 0.5)) ^ 2.0));
	else
		tmp = Float64(eps * Float64(-sin(Float64(0.5 * fma(2.0, x, eps)))));
	end
	return tmp
end
code[x_, eps_] := If[LessEqual[N[(N[Cos[N[(eps + x), $MachinePrecision]], $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision], -4e-5], N[(-2.0 * N[Power[N[Sin[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision], N[(eps * (-N[Sin[N[(0.5 * N[(2.0 * x + eps), $MachinePrecision]), $MachinePrecision]], $MachinePrecision])), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\cos \left(\varepsilon + x\right) - \cos x \leq -4 \cdot 10^{-5}:\\
\;\;\;\;-2 \cdot {\sin \left(\varepsilon \cdot 0.5\right)}^{2}\\

\mathbf{else}:\\
\;\;\;\;\varepsilon \cdot \left(-\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (cos.f64 (+.f64 x eps)) (cos.f64 x)) < -4.00000000000000033e-5

    1. Initial program 83.8%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. diff-cos84.1%

        \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
      2. div-inv84.1%

        \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      3. associate--l+84.1%

        \[\leadsto -2 \cdot \left(\sin \left(\color{blue}{\left(x + \left(\varepsilon - x\right)\right)} \cdot \frac{1}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      4. metadata-eval84.1%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot \color{blue}{0.5}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      5. div-inv84.1%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
      6. +-commutative84.1%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\color{blue}{\left(\varepsilon + x\right)} + x\right) \cdot \frac{1}{2}\right)\right) \]
      7. associate-+l+84.1%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\color{blue}{\left(\varepsilon + \left(x + x\right)\right)} \cdot \frac{1}{2}\right)\right) \]
      8. metadata-eval84.1%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
    4. Applied egg-rr84.1%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)\right)} \]
    5. Step-by-step derivation
      1. associate-*r*84.1%

        \[\leadsto \color{blue}{\left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)} \]
      2. *-commutative84.1%

        \[\leadsto \color{blue}{\sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right)} \]
      3. *-commutative84.1%

        \[\leadsto \sin \color{blue}{\left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)} \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      4. +-commutative84.1%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      5. count-284.1%

        \[\leadsto \sin \left(0.5 \cdot \left(\color{blue}{2 \cdot x} + \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      6. fma-def84.1%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\mathsf{fma}\left(2, x, \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      7. sub-neg84.1%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(\varepsilon + \left(-x\right)\right)}\right) \cdot 0.5\right)\right) \]
      8. mul-1-neg84.1%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon + \color{blue}{-1 \cdot x}\right)\right) \cdot 0.5\right)\right) \]
      9. +-commutative84.1%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(-1 \cdot x + \varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      10. associate-+r+84.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(\left(x + -1 \cdot x\right) + \varepsilon\right)} \cdot 0.5\right)\right) \]
      11. mul-1-neg84.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\left(x + \color{blue}{\left(-x\right)}\right) + \varepsilon\right) \cdot 0.5\right)\right) \]
      12. sub-neg84.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{\left(x - x\right)} + \varepsilon\right) \cdot 0.5\right)\right) \]
      13. +-inverses84.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{0} + \varepsilon\right) \cdot 0.5\right)\right) \]
      14. remove-double-neg84.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \color{blue}{\left(-\left(-\varepsilon\right)\right)}\right) \cdot 0.5\right)\right) \]
      15. mul-1-neg84.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \left(-\color{blue}{-1 \cdot \varepsilon}\right)\right) \cdot 0.5\right)\right) \]
      16. sub-neg84.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(0 - -1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      17. neg-sub084.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(--1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      18. mul-1-neg84.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(-\color{blue}{\left(-\varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      19. remove-double-neg84.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\varepsilon} \cdot 0.5\right)\right) \]
    6. Simplified84.0%

      \[\leadsto \color{blue}{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)} \]
    7. Taylor expanded in x around 0 84.5%

      \[\leadsto \color{blue}{-2 \cdot {\sin \left(0.5 \cdot \varepsilon\right)}^{2}} \]

    if -4.00000000000000033e-5 < (-.f64 (cos.f64 (+.f64 x eps)) (cos.f64 x))

    1. Initial program 21.1%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. diff-cos33.1%

        \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
      2. div-inv33.1%

        \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      3. associate--l+33.1%

        \[\leadsto -2 \cdot \left(\sin \left(\color{blue}{\left(x + \left(\varepsilon - x\right)\right)} \cdot \frac{1}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      4. metadata-eval33.1%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot \color{blue}{0.5}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      5. div-inv33.1%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
      6. +-commutative33.1%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\color{blue}{\left(\varepsilon + x\right)} + x\right) \cdot \frac{1}{2}\right)\right) \]
      7. associate-+l+33.1%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\color{blue}{\left(\varepsilon + \left(x + x\right)\right)} \cdot \frac{1}{2}\right)\right) \]
      8. metadata-eval33.1%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
    4. Applied egg-rr33.1%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)\right)} \]
    5. Step-by-step derivation
      1. associate-*r*33.1%

        \[\leadsto \color{blue}{\left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)} \]
      2. *-commutative33.1%

        \[\leadsto \color{blue}{\sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right)} \]
      3. *-commutative33.1%

        \[\leadsto \sin \color{blue}{\left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)} \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      4. +-commutative33.1%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      5. count-233.1%

        \[\leadsto \sin \left(0.5 \cdot \left(\color{blue}{2 \cdot x} + \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      6. fma-def33.1%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\mathsf{fma}\left(2, x, \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      7. sub-neg33.1%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(\varepsilon + \left(-x\right)\right)}\right) \cdot 0.5\right)\right) \]
      8. mul-1-neg33.1%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon + \color{blue}{-1 \cdot x}\right)\right) \cdot 0.5\right)\right) \]
      9. +-commutative33.1%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(-1 \cdot x + \varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      10. associate-+r+76.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(\left(x + -1 \cdot x\right) + \varepsilon\right)} \cdot 0.5\right)\right) \]
      11. mul-1-neg76.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\left(x + \color{blue}{\left(-x\right)}\right) + \varepsilon\right) \cdot 0.5\right)\right) \]
      12. sub-neg76.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{\left(x - x\right)} + \varepsilon\right) \cdot 0.5\right)\right) \]
      13. +-inverses76.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{0} + \varepsilon\right) \cdot 0.5\right)\right) \]
      14. remove-double-neg76.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \color{blue}{\left(-\left(-\varepsilon\right)\right)}\right) \cdot 0.5\right)\right) \]
      15. mul-1-neg76.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \left(-\color{blue}{-1 \cdot \varepsilon}\right)\right) \cdot 0.5\right)\right) \]
      16. sub-neg76.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(0 - -1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      17. neg-sub076.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(--1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      18. mul-1-neg76.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(-\color{blue}{\left(-\varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      19. remove-double-neg76.6%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\varepsilon} \cdot 0.5\right)\right) \]
    6. Simplified76.6%

      \[\leadsto \color{blue}{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)} \]
    7. Step-by-step derivation
      1. add-sqr-sqrt40.2%

        \[\leadsto \color{blue}{\left(\sqrt{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)} \cdot \sqrt{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)}\right)} \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
      2. sqrt-unprod50.2%

        \[\leadsto \color{blue}{\sqrt{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)}} \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
      3. pow250.2%

        \[\leadsto \sqrt{\color{blue}{{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)}^{2}}} \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
    8. Applied egg-rr50.2%

      \[\leadsto \color{blue}{\sqrt{{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)}^{2}}} \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
    9. Step-by-step derivation
      1. unpow250.2%

        \[\leadsto \sqrt{\color{blue}{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)}} \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
      2. rem-sqrt-square50.2%

        \[\leadsto \color{blue}{\left|\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)\right|} \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
    10. Simplified50.2%

      \[\leadsto \color{blue}{\left|\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)\right|} \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]
    11. Taylor expanded in eps around 0 48.2%

      \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot \left|\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)\right|\right)} \]
    12. Step-by-step derivation
      1. mul-1-neg48.2%

        \[\leadsto \color{blue}{-\varepsilon \cdot \left|\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)\right|} \]
      2. rem-square-sqrt39.5%

        \[\leadsto -\varepsilon \cdot \left|\color{blue}{\sqrt{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)} \cdot \sqrt{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)}}\right| \]
      3. fabs-sqr39.5%

        \[\leadsto -\varepsilon \cdot \color{blue}{\left(\sqrt{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)} \cdot \sqrt{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)}\right)} \]
      4. rem-square-sqrt75.2%

        \[\leadsto -\varepsilon \cdot \color{blue}{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)} \]
      5. distribute-rgt-neg-in75.2%

        \[\leadsto \color{blue}{\varepsilon \cdot \left(-\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)\right)} \]
    13. Simplified75.2%

      \[\leadsto \color{blue}{\varepsilon \cdot \left(-\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification78.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\cos \left(\varepsilon + x\right) - \cos x \leq -4 \cdot 10^{-5}:\\ \;\;\;\;-2 \cdot {\sin \left(\varepsilon \cdot 0.5\right)}^{2}\\ \mathbf{else}:\\ \;\;\;\;\varepsilon \cdot \left(-\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 66.2% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos \left(\varepsilon + x\right) - \cos x\\ \mathbf{if}\;t_0 \leq -4 \cdot 10^{-5}:\\ \;\;\;\;t_0\\ \mathbf{else}:\\ \;\;\;\;-\varepsilon \cdot \sin x\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (- (cos (+ eps x)) (cos x))))
   (if (<= t_0 -4e-5) t_0 (- (* eps (sin x))))))
double code(double x, double eps) {
	double t_0 = cos((eps + x)) - cos(x);
	double tmp;
	if (t_0 <= -4e-5) {
		tmp = t_0;
	} else {
		tmp = -(eps * sin(x));
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: t_0
    real(8) :: tmp
    t_0 = cos((eps + x)) - cos(x)
    if (t_0 <= (-4d-5)) then
        tmp = t_0
    else
        tmp = -(eps * sin(x))
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double t_0 = Math.cos((eps + x)) - Math.cos(x);
	double tmp;
	if (t_0 <= -4e-5) {
		tmp = t_0;
	} else {
		tmp = -(eps * Math.sin(x));
	}
	return tmp;
}
def code(x, eps):
	t_0 = math.cos((eps + x)) - math.cos(x)
	tmp = 0
	if t_0 <= -4e-5:
		tmp = t_0
	else:
		tmp = -(eps * math.sin(x))
	return tmp
function code(x, eps)
	t_0 = Float64(cos(Float64(eps + x)) - cos(x))
	tmp = 0.0
	if (t_0 <= -4e-5)
		tmp = t_0;
	else
		tmp = Float64(-Float64(eps * sin(x)));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	t_0 = cos((eps + x)) - cos(x);
	tmp = 0.0;
	if (t_0 <= -4e-5)
		tmp = t_0;
	else
		tmp = -(eps * sin(x));
	end
	tmp_2 = tmp;
end
code[x_, eps_] := Block[{t$95$0 = N[(N[Cos[N[(eps + x), $MachinePrecision]], $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -4e-5], t$95$0, (-N[(eps * N[Sin[x], $MachinePrecision]), $MachinePrecision])]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \cos \left(\varepsilon + x\right) - \cos x\\
\mathbf{if}\;t_0 \leq -4 \cdot 10^{-5}:\\
\;\;\;\;t_0\\

\mathbf{else}:\\
\;\;\;\;-\varepsilon \cdot \sin x\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (cos.f64 (+.f64 x eps)) (cos.f64 x)) < -4.00000000000000033e-5

    1. Initial program 83.8%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing

    if -4.00000000000000033e-5 < (-.f64 (cos.f64 (+.f64 x eps)) (cos.f64 x))

    1. Initial program 21.1%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in eps around 0 63.7%

      \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right)} \]
    4. Step-by-step derivation
      1. mul-1-neg63.7%

        \[\leadsto \color{blue}{-\varepsilon \cdot \sin x} \]
      2. *-commutative63.7%

        \[\leadsto -\color{blue}{\sin x \cdot \varepsilon} \]
      3. distribute-rgt-neg-in63.7%

        \[\leadsto \color{blue}{\sin x \cdot \left(-\varepsilon\right)} \]
    5. Simplified63.7%

      \[\leadsto \color{blue}{\sin x \cdot \left(-\varepsilon\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification70.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\cos \left(\varepsilon + x\right) - \cos x \leq -4 \cdot 10^{-5}:\\ \;\;\;\;\cos \left(\varepsilon + x\right) - \cos x\\ \mathbf{else}:\\ \;\;\;\;-\varepsilon \cdot \sin x\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 76.7% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \cdot \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \end{array} \]
(FPCore (x eps)
 :precision binary64
 (* (* -2.0 (sin (* eps 0.5))) (sin (* 0.5 (fma 2.0 x eps)))))
double code(double x, double eps) {
	return (-2.0 * sin((eps * 0.5))) * sin((0.5 * fma(2.0, x, eps)));
}
function code(x, eps)
	return Float64(Float64(-2.0 * sin(Float64(eps * 0.5))) * sin(Float64(0.5 * fma(2.0, x, eps))))
end
code[x_, eps_] := N[(N[(-2.0 * N[Sin[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[Sin[N[(0.5 * N[(2.0 * x + eps), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \cdot \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)
\end{array}
Derivation
  1. Initial program 43.6%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. diff-cos51.4%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
    2. div-inv51.4%

      \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
    3. associate--l+51.4%

      \[\leadsto -2 \cdot \left(\sin \left(\color{blue}{\left(x + \left(\varepsilon - x\right)\right)} \cdot \frac{1}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
    4. metadata-eval51.4%

      \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot \color{blue}{0.5}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
    5. div-inv51.4%

      \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
    6. +-commutative51.4%

      \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\color{blue}{\left(\varepsilon + x\right)} + x\right) \cdot \frac{1}{2}\right)\right) \]
    7. associate-+l+51.4%

      \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\color{blue}{\left(\varepsilon + \left(x + x\right)\right)} \cdot \frac{1}{2}\right)\right) \]
    8. metadata-eval51.4%

      \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
  4. Applied egg-rr51.4%

    \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)\right)} \]
  5. Step-by-step derivation
    1. associate-*r*51.4%

      \[\leadsto \color{blue}{\left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)} \]
    2. *-commutative51.4%

      \[\leadsto \color{blue}{\sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right)} \]
    3. *-commutative51.4%

      \[\leadsto \sin \color{blue}{\left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)} \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
    4. +-commutative51.4%

      \[\leadsto \sin \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
    5. count-251.4%

      \[\leadsto \sin \left(0.5 \cdot \left(\color{blue}{2 \cdot x} + \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
    6. fma-def51.4%

      \[\leadsto \sin \left(0.5 \cdot \color{blue}{\mathsf{fma}\left(2, x, \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
    7. sub-neg51.4%

      \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(\varepsilon + \left(-x\right)\right)}\right) \cdot 0.5\right)\right) \]
    8. mul-1-neg51.4%

      \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon + \color{blue}{-1 \cdot x}\right)\right) \cdot 0.5\right)\right) \]
    9. +-commutative51.4%

      \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(-1 \cdot x + \varepsilon\right)}\right) \cdot 0.5\right)\right) \]
    10. associate-+r+79.3%

      \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(\left(x + -1 \cdot x\right) + \varepsilon\right)} \cdot 0.5\right)\right) \]
    11. mul-1-neg79.3%

      \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\left(x + \color{blue}{\left(-x\right)}\right) + \varepsilon\right) \cdot 0.5\right)\right) \]
    12. sub-neg79.3%

      \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{\left(x - x\right)} + \varepsilon\right) \cdot 0.5\right)\right) \]
    13. +-inverses79.3%

      \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{0} + \varepsilon\right) \cdot 0.5\right)\right) \]
    14. remove-double-neg79.3%

      \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \color{blue}{\left(-\left(-\varepsilon\right)\right)}\right) \cdot 0.5\right)\right) \]
    15. mul-1-neg79.3%

      \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \left(-\color{blue}{-1 \cdot \varepsilon}\right)\right) \cdot 0.5\right)\right) \]
    16. sub-neg79.3%

      \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(0 - -1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
    17. neg-sub079.3%

      \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(--1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
    18. mul-1-neg79.3%

      \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(-\color{blue}{\left(-\varepsilon\right)}\right) \cdot 0.5\right)\right) \]
    19. remove-double-neg79.3%

      \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\varepsilon} \cdot 0.5\right)\right) \]
  6. Simplified79.3%

    \[\leadsto \color{blue}{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)} \]
  7. Final simplification79.3%

    \[\leadsto \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \cdot \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \]
  8. Add Preprocessing

Alternative 8: 70.2% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sin \left(\varepsilon \cdot 0.5\right)\\ \mathbf{if}\;x \leq -4 \cdot 10^{-11} \lor \neg \left(x \leq 1.8 \cdot 10^{-51}\right):\\ \;\;\;\;\sin x \cdot \left(-2 \cdot t_0\right)\\ \mathbf{else}:\\ \;\;\;\;-2 \cdot {t_0}^{2}\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (sin (* eps 0.5))))
   (if (or (<= x -4e-11) (not (<= x 1.8e-51)))
     (* (sin x) (* -2.0 t_0))
     (* -2.0 (pow t_0 2.0)))))
double code(double x, double eps) {
	double t_0 = sin((eps * 0.5));
	double tmp;
	if ((x <= -4e-11) || !(x <= 1.8e-51)) {
		tmp = sin(x) * (-2.0 * t_0);
	} else {
		tmp = -2.0 * pow(t_0, 2.0);
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: t_0
    real(8) :: tmp
    t_0 = sin((eps * 0.5d0))
    if ((x <= (-4d-11)) .or. (.not. (x <= 1.8d-51))) then
        tmp = sin(x) * ((-2.0d0) * t_0)
    else
        tmp = (-2.0d0) * (t_0 ** 2.0d0)
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double t_0 = Math.sin((eps * 0.5));
	double tmp;
	if ((x <= -4e-11) || !(x <= 1.8e-51)) {
		tmp = Math.sin(x) * (-2.0 * t_0);
	} else {
		tmp = -2.0 * Math.pow(t_0, 2.0);
	}
	return tmp;
}
def code(x, eps):
	t_0 = math.sin((eps * 0.5))
	tmp = 0
	if (x <= -4e-11) or not (x <= 1.8e-51):
		tmp = math.sin(x) * (-2.0 * t_0)
	else:
		tmp = -2.0 * math.pow(t_0, 2.0)
	return tmp
function code(x, eps)
	t_0 = sin(Float64(eps * 0.5))
	tmp = 0.0
	if ((x <= -4e-11) || !(x <= 1.8e-51))
		tmp = Float64(sin(x) * Float64(-2.0 * t_0));
	else
		tmp = Float64(-2.0 * (t_0 ^ 2.0));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	t_0 = sin((eps * 0.5));
	tmp = 0.0;
	if ((x <= -4e-11) || ~((x <= 1.8e-51)))
		tmp = sin(x) * (-2.0 * t_0);
	else
		tmp = -2.0 * (t_0 ^ 2.0);
	end
	tmp_2 = tmp;
end
code[x_, eps_] := Block[{t$95$0 = N[Sin[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision]}, If[Or[LessEqual[x, -4e-11], N[Not[LessEqual[x, 1.8e-51]], $MachinePrecision]], N[(N[Sin[x], $MachinePrecision] * N[(-2.0 * t$95$0), $MachinePrecision]), $MachinePrecision], N[(-2.0 * N[Power[t$95$0, 2.0], $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sin \left(\varepsilon \cdot 0.5\right)\\
\mathbf{if}\;x \leq -4 \cdot 10^{-11} \lor \neg \left(x \leq 1.8 \cdot 10^{-51}\right):\\
\;\;\;\;\sin x \cdot \left(-2 \cdot t_0\right)\\

\mathbf{else}:\\
\;\;\;\;-2 \cdot {t_0}^{2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -3.99999999999999976e-11 or 1.8e-51 < x

    1. Initial program 9.5%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. diff-cos9.5%

        \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
      2. div-inv9.5%

        \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      3. associate--l+9.5%

        \[\leadsto -2 \cdot \left(\sin \left(\color{blue}{\left(x + \left(\varepsilon - x\right)\right)} \cdot \frac{1}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      4. metadata-eval9.5%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot \color{blue}{0.5}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      5. div-inv9.5%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
      6. +-commutative9.5%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\color{blue}{\left(\varepsilon + x\right)} + x\right) \cdot \frac{1}{2}\right)\right) \]
      7. associate-+l+9.5%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\color{blue}{\left(\varepsilon + \left(x + x\right)\right)} \cdot \frac{1}{2}\right)\right) \]
      8. metadata-eval9.5%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
    4. Applied egg-rr9.5%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)\right)} \]
    5. Step-by-step derivation
      1. associate-*r*9.5%

        \[\leadsto \color{blue}{\left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)} \]
      2. *-commutative9.5%

        \[\leadsto \color{blue}{\sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right)} \]
      3. *-commutative9.5%

        \[\leadsto \sin \color{blue}{\left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)} \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      4. +-commutative9.5%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      5. count-29.5%

        \[\leadsto \sin \left(0.5 \cdot \left(\color{blue}{2 \cdot x} + \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      6. fma-def9.5%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\mathsf{fma}\left(2, x, \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      7. sub-neg9.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(\varepsilon + \left(-x\right)\right)}\right) \cdot 0.5\right)\right) \]
      8. mul-1-neg9.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon + \color{blue}{-1 \cdot x}\right)\right) \cdot 0.5\right)\right) \]
      9. +-commutative9.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(-1 \cdot x + \varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      10. associate-+r+60.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(\left(x + -1 \cdot x\right) + \varepsilon\right)} \cdot 0.5\right)\right) \]
      11. mul-1-neg60.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\left(x + \color{blue}{\left(-x\right)}\right) + \varepsilon\right) \cdot 0.5\right)\right) \]
      12. sub-neg60.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{\left(x - x\right)} + \varepsilon\right) \cdot 0.5\right)\right) \]
      13. +-inverses60.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{0} + \varepsilon\right) \cdot 0.5\right)\right) \]
      14. remove-double-neg60.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \color{blue}{\left(-\left(-\varepsilon\right)\right)}\right) \cdot 0.5\right)\right) \]
      15. mul-1-neg60.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \left(-\color{blue}{-1 \cdot \varepsilon}\right)\right) \cdot 0.5\right)\right) \]
      16. sub-neg60.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(0 - -1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      17. neg-sub060.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(--1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      18. mul-1-neg60.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(-\color{blue}{\left(-\varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      19. remove-double-neg60.0%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\varepsilon} \cdot 0.5\right)\right) \]
    6. Simplified60.0%

      \[\leadsto \color{blue}{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)} \]
    7. Taylor expanded in eps around 0 57.4%

      \[\leadsto \color{blue}{\sin x} \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \]

    if -3.99999999999999976e-11 < x < 1.8e-51

    1. Initial program 79.4%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. diff-cos95.3%

        \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
      2. div-inv95.3%

        \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      3. associate--l+95.3%

        \[\leadsto -2 \cdot \left(\sin \left(\color{blue}{\left(x + \left(\varepsilon - x\right)\right)} \cdot \frac{1}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      4. metadata-eval95.3%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot \color{blue}{0.5}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      5. div-inv95.3%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
      6. +-commutative95.3%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\color{blue}{\left(\varepsilon + x\right)} + x\right) \cdot \frac{1}{2}\right)\right) \]
      7. associate-+l+95.3%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\color{blue}{\left(\varepsilon + \left(x + x\right)\right)} \cdot \frac{1}{2}\right)\right) \]
      8. metadata-eval95.3%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
    4. Applied egg-rr95.3%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)\right)} \]
    5. Step-by-step derivation
      1. associate-*r*95.3%

        \[\leadsto \color{blue}{\left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)} \]
      2. *-commutative95.3%

        \[\leadsto \color{blue}{\sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right)} \]
      3. *-commutative95.3%

        \[\leadsto \sin \color{blue}{\left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)} \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      4. +-commutative95.3%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      5. count-295.3%

        \[\leadsto \sin \left(0.5 \cdot \left(\color{blue}{2 \cdot x} + \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      6. fma-def95.3%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\mathsf{fma}\left(2, x, \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      7. sub-neg95.3%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(\varepsilon + \left(-x\right)\right)}\right) \cdot 0.5\right)\right) \]
      8. mul-1-neg95.3%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon + \color{blue}{-1 \cdot x}\right)\right) \cdot 0.5\right)\right) \]
      9. +-commutative95.3%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(-1 \cdot x + \varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      10. associate-+r+99.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(\left(x + -1 \cdot x\right) + \varepsilon\right)} \cdot 0.5\right)\right) \]
      11. mul-1-neg99.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\left(x + \color{blue}{\left(-x\right)}\right) + \varepsilon\right) \cdot 0.5\right)\right) \]
      12. sub-neg99.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{\left(x - x\right)} + \varepsilon\right) \cdot 0.5\right)\right) \]
      13. +-inverses99.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{0} + \varepsilon\right) \cdot 0.5\right)\right) \]
      14. remove-double-neg99.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \color{blue}{\left(-\left(-\varepsilon\right)\right)}\right) \cdot 0.5\right)\right) \]
      15. mul-1-neg99.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \left(-\color{blue}{-1 \cdot \varepsilon}\right)\right) \cdot 0.5\right)\right) \]
      16. sub-neg99.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(0 - -1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      17. neg-sub099.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(--1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      18. mul-1-neg99.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(-\color{blue}{\left(-\varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      19. remove-double-neg99.5%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\varepsilon} \cdot 0.5\right)\right) \]
    6. Simplified99.5%

      \[\leadsto \color{blue}{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)} \]
    7. Taylor expanded in x around 0 94.3%

      \[\leadsto \color{blue}{-2 \cdot {\sin \left(0.5 \cdot \varepsilon\right)}^{2}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification75.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -4 \cdot 10^{-11} \lor \neg \left(x \leq 1.8 \cdot 10^{-51}\right):\\ \;\;\;\;\sin x \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)\\ \mathbf{else}:\\ \;\;\;\;-2 \cdot {\sin \left(\varepsilon \cdot 0.5\right)}^{2}\\ \end{array} \]
  5. Add Preprocessing

Alternative 9: 67.9% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.023:\\ \;\;\;\;\cos \varepsilon - \cos x\\ \mathbf{elif}\;\varepsilon \leq 1.75 \cdot 10^{-47}:\\ \;\;\;\;-\varepsilon \cdot \sin x\\ \mathbf{else}:\\ \;\;\;\;-2 \cdot {\sin \left(\varepsilon \cdot 0.5\right)}^{2}\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (<= eps -0.023)
   (- (cos eps) (cos x))
   (if (<= eps 1.75e-47)
     (- (* eps (sin x)))
     (* -2.0 (pow (sin (* eps 0.5)) 2.0)))))
double code(double x, double eps) {
	double tmp;
	if (eps <= -0.023) {
		tmp = cos(eps) - cos(x);
	} else if (eps <= 1.75e-47) {
		tmp = -(eps * sin(x));
	} else {
		tmp = -2.0 * pow(sin((eps * 0.5)), 2.0);
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if (eps <= (-0.023d0)) then
        tmp = cos(eps) - cos(x)
    else if (eps <= 1.75d-47) then
        tmp = -(eps * sin(x))
    else
        tmp = (-2.0d0) * (sin((eps * 0.5d0)) ** 2.0d0)
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if (eps <= -0.023) {
		tmp = Math.cos(eps) - Math.cos(x);
	} else if (eps <= 1.75e-47) {
		tmp = -(eps * Math.sin(x));
	} else {
		tmp = -2.0 * Math.pow(Math.sin((eps * 0.5)), 2.0);
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if eps <= -0.023:
		tmp = math.cos(eps) - math.cos(x)
	elif eps <= 1.75e-47:
		tmp = -(eps * math.sin(x))
	else:
		tmp = -2.0 * math.pow(math.sin((eps * 0.5)), 2.0)
	return tmp
function code(x, eps)
	tmp = 0.0
	if (eps <= -0.023)
		tmp = Float64(cos(eps) - cos(x));
	elseif (eps <= 1.75e-47)
		tmp = Float64(-Float64(eps * sin(x)));
	else
		tmp = Float64(-2.0 * (sin(Float64(eps * 0.5)) ^ 2.0));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if (eps <= -0.023)
		tmp = cos(eps) - cos(x);
	elseif (eps <= 1.75e-47)
		tmp = -(eps * sin(x));
	else
		tmp = -2.0 * (sin((eps * 0.5)) ^ 2.0);
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[LessEqual[eps, -0.023], N[(N[Cos[eps], $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision], If[LessEqual[eps, 1.75e-47], (-N[(eps * N[Sin[x], $MachinePrecision]), $MachinePrecision]), N[(-2.0 * N[Power[N[Sin[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\varepsilon \leq -0.023:\\
\;\;\;\;\cos \varepsilon - \cos x\\

\mathbf{elif}\;\varepsilon \leq 1.75 \cdot 10^{-47}:\\
\;\;\;\;-\varepsilon \cdot \sin x\\

\mathbf{else}:\\
\;\;\;\;-2 \cdot {\sin \left(\varepsilon \cdot 0.5\right)}^{2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if eps < -0.023

    1. Initial program 57.0%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 58.8%

      \[\leadsto \color{blue}{\cos \varepsilon} - \cos x \]

    if -0.023 < eps < 1.7499999999999999e-47

    1. Initial program 27.9%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in eps around 0 87.4%

      \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right)} \]
    4. Step-by-step derivation
      1. mul-1-neg87.4%

        \[\leadsto \color{blue}{-\varepsilon \cdot \sin x} \]
      2. *-commutative87.4%

        \[\leadsto -\color{blue}{\sin x \cdot \varepsilon} \]
      3. distribute-rgt-neg-in87.4%

        \[\leadsto \color{blue}{\sin x \cdot \left(-\varepsilon\right)} \]
    5. Simplified87.4%

      \[\leadsto \color{blue}{\sin x \cdot \left(-\varepsilon\right)} \]

    if 1.7499999999999999e-47 < eps

    1. Initial program 56.1%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. diff-cos64.4%

        \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
      2. div-inv64.4%

        \[\leadsto -2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      3. associate--l+64.4%

        \[\leadsto -2 \cdot \left(\sin \left(\color{blue}{\left(x + \left(\varepsilon - x\right)\right)} \cdot \frac{1}{2}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      4. metadata-eval64.4%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot \color{blue}{0.5}\right) \cdot \sin \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      5. div-inv64.4%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
      6. +-commutative64.4%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\color{blue}{\left(\varepsilon + x\right)} + x\right) \cdot \frac{1}{2}\right)\right) \]
      7. associate-+l+64.4%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\color{blue}{\left(\varepsilon + \left(x + x\right)\right)} \cdot \frac{1}{2}\right)\right) \]
      8. metadata-eval64.4%

        \[\leadsto -2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
    4. Applied egg-rr64.4%

      \[\leadsto \color{blue}{-2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)\right)} \]
    5. Step-by-step derivation
      1. associate-*r*64.4%

        \[\leadsto \color{blue}{\left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \cdot \sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)} \]
      2. *-commutative64.4%

        \[\leadsto \color{blue}{\sin \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right)} \]
      3. *-commutative64.4%

        \[\leadsto \sin \color{blue}{\left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)} \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      4. +-commutative64.4%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      5. count-264.4%

        \[\leadsto \sin \left(0.5 \cdot \left(\color{blue}{2 \cdot x} + \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      6. fma-def64.4%

        \[\leadsto \sin \left(0.5 \cdot \color{blue}{\mathsf{fma}\left(2, x, \varepsilon\right)}\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      7. sub-neg64.4%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(\varepsilon + \left(-x\right)\right)}\right) \cdot 0.5\right)\right) \]
      8. mul-1-neg64.4%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \left(\varepsilon + \color{blue}{-1 \cdot x}\right)\right) \cdot 0.5\right)\right) \]
      9. +-commutative64.4%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(x + \color{blue}{\left(-1 \cdot x + \varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      10. associate-+r+68.1%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(\left(x + -1 \cdot x\right) + \varepsilon\right)} \cdot 0.5\right)\right) \]
      11. mul-1-neg68.1%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\left(x + \color{blue}{\left(-x\right)}\right) + \varepsilon\right) \cdot 0.5\right)\right) \]
      12. sub-neg68.1%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{\left(x - x\right)} + \varepsilon\right) \cdot 0.5\right)\right) \]
      13. +-inverses68.1%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(\color{blue}{0} + \varepsilon\right) \cdot 0.5\right)\right) \]
      14. remove-double-neg68.1%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \color{blue}{\left(-\left(-\varepsilon\right)\right)}\right) \cdot 0.5\right)\right) \]
      15. mul-1-neg68.1%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(0 + \left(-\color{blue}{-1 \cdot \varepsilon}\right)\right) \cdot 0.5\right)\right) \]
      16. sub-neg68.1%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(0 - -1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      17. neg-sub068.1%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\left(--1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      18. mul-1-neg68.1%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\left(-\color{blue}{\left(-\varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      19. remove-double-neg68.1%

        \[\leadsto \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\color{blue}{\varepsilon} \cdot 0.5\right)\right) \]
    6. Simplified68.1%

      \[\leadsto \color{blue}{\sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(-2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)} \]
    7. Taylor expanded in x around 0 66.4%

      \[\leadsto \color{blue}{-2 \cdot {\sin \left(0.5 \cdot \varepsilon\right)}^{2}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification73.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.023:\\ \;\;\;\;\cos \varepsilon - \cos x\\ \mathbf{elif}\;\varepsilon \leq 1.75 \cdot 10^{-47}:\\ \;\;\;\;-\varepsilon \cdot \sin x\\ \mathbf{else}:\\ \;\;\;\;-2 \cdot {\sin \left(\varepsilon \cdot 0.5\right)}^{2}\\ \end{array} \]
  5. Add Preprocessing

Alternative 10: 67.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.023:\\ \;\;\;\;\cos \varepsilon - \cos x\\ \mathbf{elif}\;\varepsilon \leq 2.3 \cdot 10^{-6}:\\ \;\;\;\;-\varepsilon \cdot \sin x\\ \mathbf{else}:\\ \;\;\;\;\cos \varepsilon + -1\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (<= eps -0.023)
   (- (cos eps) (cos x))
   (if (<= eps 2.3e-6) (- (* eps (sin x))) (+ (cos eps) -1.0))))
double code(double x, double eps) {
	double tmp;
	if (eps <= -0.023) {
		tmp = cos(eps) - cos(x);
	} else if (eps <= 2.3e-6) {
		tmp = -(eps * sin(x));
	} else {
		tmp = cos(eps) + -1.0;
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if (eps <= (-0.023d0)) then
        tmp = cos(eps) - cos(x)
    else if (eps <= 2.3d-6) then
        tmp = -(eps * sin(x))
    else
        tmp = cos(eps) + (-1.0d0)
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if (eps <= -0.023) {
		tmp = Math.cos(eps) - Math.cos(x);
	} else if (eps <= 2.3e-6) {
		tmp = -(eps * Math.sin(x));
	} else {
		tmp = Math.cos(eps) + -1.0;
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if eps <= -0.023:
		tmp = math.cos(eps) - math.cos(x)
	elif eps <= 2.3e-6:
		tmp = -(eps * math.sin(x))
	else:
		tmp = math.cos(eps) + -1.0
	return tmp
function code(x, eps)
	tmp = 0.0
	if (eps <= -0.023)
		tmp = Float64(cos(eps) - cos(x));
	elseif (eps <= 2.3e-6)
		tmp = Float64(-Float64(eps * sin(x)));
	else
		tmp = Float64(cos(eps) + -1.0);
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if (eps <= -0.023)
		tmp = cos(eps) - cos(x);
	elseif (eps <= 2.3e-6)
		tmp = -(eps * sin(x));
	else
		tmp = cos(eps) + -1.0;
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[LessEqual[eps, -0.023], N[(N[Cos[eps], $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision], If[LessEqual[eps, 2.3e-6], (-N[(eps * N[Sin[x], $MachinePrecision]), $MachinePrecision]), N[(N[Cos[eps], $MachinePrecision] + -1.0), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\varepsilon \leq -0.023:\\
\;\;\;\;\cos \varepsilon - \cos x\\

\mathbf{elif}\;\varepsilon \leq 2.3 \cdot 10^{-6}:\\
\;\;\;\;-\varepsilon \cdot \sin x\\

\mathbf{else}:\\
\;\;\;\;\cos \varepsilon + -1\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if eps < -0.023

    1. Initial program 57.0%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 58.8%

      \[\leadsto \color{blue}{\cos \varepsilon} - \cos x \]

    if -0.023 < eps < 2.3e-6

    1. Initial program 26.1%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in eps around 0 83.3%

      \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right)} \]
    4. Step-by-step derivation
      1. mul-1-neg83.3%

        \[\leadsto \color{blue}{-\varepsilon \cdot \sin x} \]
      2. *-commutative83.3%

        \[\leadsto -\color{blue}{\sin x \cdot \varepsilon} \]
      3. distribute-rgt-neg-in83.3%

        \[\leadsto \color{blue}{\sin x \cdot \left(-\varepsilon\right)} \]
    5. Simplified83.3%

      \[\leadsto \color{blue}{\sin x \cdot \left(-\varepsilon\right)} \]

    if 2.3e-6 < eps

    1. Initial program 63.1%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 65.7%

      \[\leadsto \color{blue}{\cos \varepsilon - 1} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification72.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.023:\\ \;\;\;\;\cos \varepsilon - \cos x\\ \mathbf{elif}\;\varepsilon \leq 2.3 \cdot 10^{-6}:\\ \;\;\;\;-\varepsilon \cdot \sin x\\ \mathbf{else}:\\ \;\;\;\;\cos \varepsilon + -1\\ \end{array} \]
  5. Add Preprocessing

Alternative 11: 49.2% accurate, 1.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos \varepsilon + -1\\ t_1 := -0.5 \cdot \left(\varepsilon \cdot \varepsilon\right)\\ \mathbf{if}\;\varepsilon \leq -0.023:\\ \;\;\;\;t_0\\ \mathbf{elif}\;\varepsilon \leq -2.1 \cdot 10^{-150}:\\ \;\;\;\;t_1\\ \mathbf{elif}\;\varepsilon \leq 1.45 \cdot 10^{-148}:\\ \;\;\;\;\varepsilon \cdot \left(-x\right)\\ \mathbf{elif}\;\varepsilon \leq 0.00017:\\ \;\;\;\;t_1\\ \mathbf{else}:\\ \;\;\;\;t_0\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (+ (cos eps) -1.0)) (t_1 (* -0.5 (* eps eps))))
   (if (<= eps -0.023)
     t_0
     (if (<= eps -2.1e-150)
       t_1
       (if (<= eps 1.45e-148) (* eps (- x)) (if (<= eps 0.00017) t_1 t_0))))))
double code(double x, double eps) {
	double t_0 = cos(eps) + -1.0;
	double t_1 = -0.5 * (eps * eps);
	double tmp;
	if (eps <= -0.023) {
		tmp = t_0;
	} else if (eps <= -2.1e-150) {
		tmp = t_1;
	} else if (eps <= 1.45e-148) {
		tmp = eps * -x;
	} else if (eps <= 0.00017) {
		tmp = t_1;
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = cos(eps) + (-1.0d0)
    t_1 = (-0.5d0) * (eps * eps)
    if (eps <= (-0.023d0)) then
        tmp = t_0
    else if (eps <= (-2.1d-150)) then
        tmp = t_1
    else if (eps <= 1.45d-148) then
        tmp = eps * -x
    else if (eps <= 0.00017d0) then
        tmp = t_1
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double t_0 = Math.cos(eps) + -1.0;
	double t_1 = -0.5 * (eps * eps);
	double tmp;
	if (eps <= -0.023) {
		tmp = t_0;
	} else if (eps <= -2.1e-150) {
		tmp = t_1;
	} else if (eps <= 1.45e-148) {
		tmp = eps * -x;
	} else if (eps <= 0.00017) {
		tmp = t_1;
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x, eps):
	t_0 = math.cos(eps) + -1.0
	t_1 = -0.5 * (eps * eps)
	tmp = 0
	if eps <= -0.023:
		tmp = t_0
	elif eps <= -2.1e-150:
		tmp = t_1
	elif eps <= 1.45e-148:
		tmp = eps * -x
	elif eps <= 0.00017:
		tmp = t_1
	else:
		tmp = t_0
	return tmp
function code(x, eps)
	t_0 = Float64(cos(eps) + -1.0)
	t_1 = Float64(-0.5 * Float64(eps * eps))
	tmp = 0.0
	if (eps <= -0.023)
		tmp = t_0;
	elseif (eps <= -2.1e-150)
		tmp = t_1;
	elseif (eps <= 1.45e-148)
		tmp = Float64(eps * Float64(-x));
	elseif (eps <= 0.00017)
		tmp = t_1;
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x, eps)
	t_0 = cos(eps) + -1.0;
	t_1 = -0.5 * (eps * eps);
	tmp = 0.0;
	if (eps <= -0.023)
		tmp = t_0;
	elseif (eps <= -2.1e-150)
		tmp = t_1;
	elseif (eps <= 1.45e-148)
		tmp = eps * -x;
	elseif (eps <= 0.00017)
		tmp = t_1;
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_, eps_] := Block[{t$95$0 = N[(N[Cos[eps], $MachinePrecision] + -1.0), $MachinePrecision]}, Block[{t$95$1 = N[(-0.5 * N[(eps * eps), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[eps, -0.023], t$95$0, If[LessEqual[eps, -2.1e-150], t$95$1, If[LessEqual[eps, 1.45e-148], N[(eps * (-x)), $MachinePrecision], If[LessEqual[eps, 0.00017], t$95$1, t$95$0]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \cos \varepsilon + -1\\
t_1 := -0.5 \cdot \left(\varepsilon \cdot \varepsilon\right)\\
\mathbf{if}\;\varepsilon \leq -0.023:\\
\;\;\;\;t_0\\

\mathbf{elif}\;\varepsilon \leq -2.1 \cdot 10^{-150}:\\
\;\;\;\;t_1\\

\mathbf{elif}\;\varepsilon \leq 1.45 \cdot 10^{-148}:\\
\;\;\;\;\varepsilon \cdot \left(-x\right)\\

\mathbf{elif}\;\varepsilon \leq 0.00017:\\
\;\;\;\;t_1\\

\mathbf{else}:\\
\;\;\;\;t_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if eps < -0.023 or 1.7e-4 < eps

    1. Initial program 60.1%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 61.8%

      \[\leadsto \color{blue}{\cos \varepsilon - 1} \]

    if -0.023 < eps < -2.1000000000000001e-150 or 1.4499999999999999e-148 < eps < 1.7e-4

    1. Initial program 4.2%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 4.6%

      \[\leadsto \color{blue}{\cos \varepsilon - 1} \]
    4. Taylor expanded in eps around 0 38.1%

      \[\leadsto \color{blue}{-0.5 \cdot {\varepsilon}^{2}} \]
    5. Step-by-step derivation
      1. unpow238.1%

        \[\leadsto -0.5 \cdot \color{blue}{\left(\varepsilon \cdot \varepsilon\right)} \]
    6. Applied egg-rr38.1%

      \[\leadsto -0.5 \cdot \color{blue}{\left(\varepsilon \cdot \varepsilon\right)} \]

    if -2.1000000000000001e-150 < eps < 1.4499999999999999e-148

    1. Initial program 43.5%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in eps around 0 43.5%

      \[\leadsto \color{blue}{\left(\cos x + -1 \cdot \left(\varepsilon \cdot \sin x\right)\right)} - \cos x \]
    4. Step-by-step derivation
      1. mul-1-neg43.5%

        \[\leadsto \left(\cos x + \color{blue}{\left(-\varepsilon \cdot \sin x\right)}\right) - \cos x \]
      2. unsub-neg43.5%

        \[\leadsto \color{blue}{\left(\cos x - \varepsilon \cdot \sin x\right)} - \cos x \]
    5. Simplified43.5%

      \[\leadsto \color{blue}{\left(\cos x - \varepsilon \cdot \sin x\right)} - \cos x \]
    6. Taylor expanded in x around 0 53.9%

      \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot x\right)} \]
    7. Step-by-step derivation
      1. associate-*r*53.9%

        \[\leadsto \color{blue}{\left(-1 \cdot \varepsilon\right) \cdot x} \]
      2. neg-mul-153.9%

        \[\leadsto \color{blue}{\left(-\varepsilon\right)} \cdot x \]
    8. Simplified53.9%

      \[\leadsto \color{blue}{\left(-\varepsilon\right) \cdot x} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification54.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.023:\\ \;\;\;\;\cos \varepsilon + -1\\ \mathbf{elif}\;\varepsilon \leq -2.1 \cdot 10^{-150}:\\ \;\;\;\;-0.5 \cdot \left(\varepsilon \cdot \varepsilon\right)\\ \mathbf{elif}\;\varepsilon \leq 1.45 \cdot 10^{-148}:\\ \;\;\;\;\varepsilon \cdot \left(-x\right)\\ \mathbf{elif}\;\varepsilon \leq 0.00017:\\ \;\;\;\;-0.5 \cdot \left(\varepsilon \cdot \varepsilon\right)\\ \mathbf{else}:\\ \;\;\;\;\cos \varepsilon + -1\\ \end{array} \]
  5. Add Preprocessing

Alternative 12: 67.4% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.023 \lor \neg \left(\varepsilon \leq 2.4 \cdot 10^{-6}\right):\\ \;\;\;\;\cos \varepsilon + -1\\ \mathbf{else}:\\ \;\;\;\;-\varepsilon \cdot \sin x\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (or (<= eps -0.023) (not (<= eps 2.4e-6)))
   (+ (cos eps) -1.0)
   (- (* eps (sin x)))))
double code(double x, double eps) {
	double tmp;
	if ((eps <= -0.023) || !(eps <= 2.4e-6)) {
		tmp = cos(eps) + -1.0;
	} else {
		tmp = -(eps * sin(x));
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if ((eps <= (-0.023d0)) .or. (.not. (eps <= 2.4d-6))) then
        tmp = cos(eps) + (-1.0d0)
    else
        tmp = -(eps * sin(x))
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if ((eps <= -0.023) || !(eps <= 2.4e-6)) {
		tmp = Math.cos(eps) + -1.0;
	} else {
		tmp = -(eps * Math.sin(x));
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if (eps <= -0.023) or not (eps <= 2.4e-6):
		tmp = math.cos(eps) + -1.0
	else:
		tmp = -(eps * math.sin(x))
	return tmp
function code(x, eps)
	tmp = 0.0
	if ((eps <= -0.023) || !(eps <= 2.4e-6))
		tmp = Float64(cos(eps) + -1.0);
	else
		tmp = Float64(-Float64(eps * sin(x)));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if ((eps <= -0.023) || ~((eps <= 2.4e-6)))
		tmp = cos(eps) + -1.0;
	else
		tmp = -(eps * sin(x));
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[Or[LessEqual[eps, -0.023], N[Not[LessEqual[eps, 2.4e-6]], $MachinePrecision]], N[(N[Cos[eps], $MachinePrecision] + -1.0), $MachinePrecision], (-N[(eps * N[Sin[x], $MachinePrecision]), $MachinePrecision])]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\varepsilon \leq -0.023 \lor \neg \left(\varepsilon \leq 2.4 \cdot 10^{-6}\right):\\
\;\;\;\;\cos \varepsilon + -1\\

\mathbf{else}:\\
\;\;\;\;-\varepsilon \cdot \sin x\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if eps < -0.023 or 2.3999999999999999e-6 < eps

    1. Initial program 60.1%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 61.8%

      \[\leadsto \color{blue}{\cos \varepsilon - 1} \]

    if -0.023 < eps < 2.3999999999999999e-6

    1. Initial program 26.1%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in eps around 0 83.3%

      \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot \sin x\right)} \]
    4. Step-by-step derivation
      1. mul-1-neg83.3%

        \[\leadsto \color{blue}{-\varepsilon \cdot \sin x} \]
      2. *-commutative83.3%

        \[\leadsto -\color{blue}{\sin x \cdot \varepsilon} \]
      3. distribute-rgt-neg-in83.3%

        \[\leadsto \color{blue}{\sin x \cdot \left(-\varepsilon\right)} \]
    5. Simplified83.3%

      \[\leadsto \color{blue}{\sin x \cdot \left(-\varepsilon\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification72.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.023 \lor \neg \left(\varepsilon \leq 2.4 \cdot 10^{-6}\right):\\ \;\;\;\;\cos \varepsilon + -1\\ \mathbf{else}:\\ \;\;\;\;-\varepsilon \cdot \sin x\\ \end{array} \]
  5. Add Preprocessing

Alternative 13: 22.7% accurate, 20.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 2.25 \cdot 10^{-75}:\\ \;\;\;\;-0.5 \cdot \left(\varepsilon \cdot \varepsilon\right)\\ \mathbf{else}:\\ \;\;\;\;\varepsilon \cdot \left(-x\right)\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (<= x 2.25e-75) (* -0.5 (* eps eps)) (* eps (- x))))
double code(double x, double eps) {
	double tmp;
	if (x <= 2.25e-75) {
		tmp = -0.5 * (eps * eps);
	} else {
		tmp = eps * -x;
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if (x <= 2.25d-75) then
        tmp = (-0.5d0) * (eps * eps)
    else
        tmp = eps * -x
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if (x <= 2.25e-75) {
		tmp = -0.5 * (eps * eps);
	} else {
		tmp = eps * -x;
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if x <= 2.25e-75:
		tmp = -0.5 * (eps * eps)
	else:
		tmp = eps * -x
	return tmp
function code(x, eps)
	tmp = 0.0
	if (x <= 2.25e-75)
		tmp = Float64(-0.5 * Float64(eps * eps));
	else
		tmp = Float64(eps * Float64(-x));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if (x <= 2.25e-75)
		tmp = -0.5 * (eps * eps);
	else
		tmp = eps * -x;
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[LessEqual[x, 2.25e-75], N[(-0.5 * N[(eps * eps), $MachinePrecision]), $MachinePrecision], N[(eps * (-x)), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 2.25 \cdot 10^{-75}:\\
\;\;\;\;-0.5 \cdot \left(\varepsilon \cdot \varepsilon\right)\\

\mathbf{else}:\\
\;\;\;\;\varepsilon \cdot \left(-x\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 2.2500000000000002e-75

    1. Initial program 56.2%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 57.1%

      \[\leadsto \color{blue}{\cos \varepsilon - 1} \]
    4. Taylor expanded in eps around 0 28.9%

      \[\leadsto \color{blue}{-0.5 \cdot {\varepsilon}^{2}} \]
    5. Step-by-step derivation
      1. unpow228.9%

        \[\leadsto -0.5 \cdot \color{blue}{\left(\varepsilon \cdot \varepsilon\right)} \]
    6. Applied egg-rr28.9%

      \[\leadsto -0.5 \cdot \color{blue}{\left(\varepsilon \cdot \varepsilon\right)} \]

    if 2.2500000000000002e-75 < x

    1. Initial program 13.2%

      \[\cos \left(x + \varepsilon\right) - \cos x \]
    2. Add Preprocessing
    3. Taylor expanded in eps around 0 5.7%

      \[\leadsto \color{blue}{\left(\cos x + -1 \cdot \left(\varepsilon \cdot \sin x\right)\right)} - \cos x \]
    4. Step-by-step derivation
      1. mul-1-neg5.7%

        \[\leadsto \left(\cos x + \color{blue}{\left(-\varepsilon \cdot \sin x\right)}\right) - \cos x \]
      2. unsub-neg5.7%

        \[\leadsto \color{blue}{\left(\cos x - \varepsilon \cdot \sin x\right)} - \cos x \]
    5. Simplified5.7%

      \[\leadsto \color{blue}{\left(\cos x - \varepsilon \cdot \sin x\right)} - \cos x \]
    6. Taylor expanded in x around 0 12.4%

      \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot x\right)} \]
    7. Step-by-step derivation
      1. associate-*r*12.4%

        \[\leadsto \color{blue}{\left(-1 \cdot \varepsilon\right) \cdot x} \]
      2. neg-mul-112.4%

        \[\leadsto \color{blue}{\left(-\varepsilon\right)} \cdot x \]
    8. Simplified12.4%

      \[\leadsto \color{blue}{\left(-\varepsilon\right) \cdot x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification24.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 2.25 \cdot 10^{-75}:\\ \;\;\;\;-0.5 \cdot \left(\varepsilon \cdot \varepsilon\right)\\ \mathbf{else}:\\ \;\;\;\;\varepsilon \cdot \left(-x\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 14: 18.0% accurate, 51.3× speedup?

\[\begin{array}{l} \\ \varepsilon \cdot \left(-x\right) \end{array} \]
(FPCore (x eps) :precision binary64 (* eps (- x)))
double code(double x, double eps) {
	return eps * -x;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = eps * -x
end function
public static double code(double x, double eps) {
	return eps * -x;
}
def code(x, eps):
	return eps * -x
function code(x, eps)
	return Float64(eps * Float64(-x))
end
function tmp = code(x, eps)
	tmp = eps * -x;
end
code[x_, eps_] := N[(eps * (-x)), $MachinePrecision]
\begin{array}{l}

\\
\varepsilon \cdot \left(-x\right)
\end{array}
Derivation
  1. Initial program 43.6%

    \[\cos \left(x + \varepsilon\right) - \cos x \]
  2. Add Preprocessing
  3. Taylor expanded in eps around 0 15.0%

    \[\leadsto \color{blue}{\left(\cos x + -1 \cdot \left(\varepsilon \cdot \sin x\right)\right)} - \cos x \]
  4. Step-by-step derivation
    1. mul-1-neg15.0%

      \[\leadsto \left(\cos x + \color{blue}{\left(-\varepsilon \cdot \sin x\right)}\right) - \cos x \]
    2. unsub-neg15.0%

      \[\leadsto \color{blue}{\left(\cos x - \varepsilon \cdot \sin x\right)} - \cos x \]
  5. Simplified15.0%

    \[\leadsto \color{blue}{\left(\cos x - \varepsilon \cdot \sin x\right)} - \cos x \]
  6. Taylor expanded in x around 0 18.9%

    \[\leadsto \color{blue}{-1 \cdot \left(\varepsilon \cdot x\right)} \]
  7. Step-by-step derivation
    1. associate-*r*18.9%

      \[\leadsto \color{blue}{\left(-1 \cdot \varepsilon\right) \cdot x} \]
    2. neg-mul-118.9%

      \[\leadsto \color{blue}{\left(-\varepsilon\right)} \cdot x \]
  8. Simplified18.9%

    \[\leadsto \color{blue}{\left(-\varepsilon\right) \cdot x} \]
  9. Final simplification18.9%

    \[\leadsto \varepsilon \cdot \left(-x\right) \]
  10. Add Preprocessing

Reproduce

?
herbie shell --seed 2024020 
(FPCore (x eps)
  :name "2cos (problem 3.3.5)"
  :precision binary64
  (- (cos (+ x eps)) (cos x)))