2sin (example 3.3)

Percentage Accurate: 41.9% → 99.6%
Time: 14.9s
Alternatives: 9
Speedup: 2.0×

Specification

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

\\
\sin \left(x + \varepsilon\right) - \sin 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 9 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: 41.9% accurate, 1.0× speedup?

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

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

Alternative 1: 99.6% accurate, 0.5× speedup?

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

\\
\sin \varepsilon \cdot \left(\cos x - \tan \left(\varepsilon \cdot 0.5\right) \cdot \sin x\right)
\end{array}
Derivation
  1. Initial program 44.8%

    \[\sin \left(x + \varepsilon\right) - \sin x \]
  2. Step-by-step derivation
    1. sin-sum71.0%

      \[\leadsto \color{blue}{\left(\sin x \cdot \cos \varepsilon + \cos x \cdot \sin \varepsilon\right)} - \sin x \]
    2. associate--l+71.0%

      \[\leadsto \color{blue}{\sin x \cdot \cos \varepsilon + \left(\cos x \cdot \sin \varepsilon - \sin x\right)} \]
  3. Applied egg-rr71.0%

    \[\leadsto \color{blue}{\sin x \cdot \cos \varepsilon + \left(\cos x \cdot \sin \varepsilon - \sin x\right)} \]
  4. Step-by-step derivation
    1. +-commutative71.0%

      \[\leadsto \color{blue}{\left(\cos x \cdot \sin \varepsilon - \sin x\right) + \sin x \cdot \cos \varepsilon} \]
    2. associate-+l-99.3%

      \[\leadsto \color{blue}{\cos x \cdot \sin \varepsilon - \left(\sin x - \sin x \cdot \cos \varepsilon\right)} \]
    3. *-commutative99.3%

      \[\leadsto \color{blue}{\sin \varepsilon \cdot \cos x} - \left(\sin x - \sin x \cdot \cos \varepsilon\right) \]
    4. *-rgt-identity99.3%

      \[\leadsto \sin \varepsilon \cdot \cos x - \left(\color{blue}{\sin x \cdot 1} - \sin x \cdot \cos \varepsilon\right) \]
    5. distribute-lft-out--99.4%

      \[\leadsto \sin \varepsilon \cdot \cos x - \color{blue}{\sin x \cdot \left(1 - \cos \varepsilon\right)} \]
  5. Simplified99.4%

    \[\leadsto \color{blue}{\sin \varepsilon \cdot \cos x - \sin x \cdot \left(1 - \cos \varepsilon\right)} \]
  6. Step-by-step derivation
    1. flip--99.3%

      \[\leadsto \sin \varepsilon \cdot \cos x - \sin x \cdot \color{blue}{\frac{1 \cdot 1 - \cos \varepsilon \cdot \cos \varepsilon}{1 + \cos \varepsilon}} \]
    2. div-inv99.3%

      \[\leadsto \sin \varepsilon \cdot \cos x - \sin x \cdot \color{blue}{\left(\left(1 \cdot 1 - \cos \varepsilon \cdot \cos \varepsilon\right) \cdot \frac{1}{1 + \cos \varepsilon}\right)} \]
    3. metadata-eval99.3%

      \[\leadsto \sin \varepsilon \cdot \cos x - \sin x \cdot \left(\left(\color{blue}{1} - \cos \varepsilon \cdot \cos \varepsilon\right) \cdot \frac{1}{1 + \cos \varepsilon}\right) \]
    4. 1-sub-cos99.6%

      \[\leadsto \sin \varepsilon \cdot \cos x - \sin x \cdot \left(\color{blue}{\left(\sin \varepsilon \cdot \sin \varepsilon\right)} \cdot \frac{1}{1 + \cos \varepsilon}\right) \]
    5. pow299.6%

      \[\leadsto \sin \varepsilon \cdot \cos x - \sin x \cdot \left(\color{blue}{{\sin \varepsilon}^{2}} \cdot \frac{1}{1 + \cos \varepsilon}\right) \]
  7. Applied egg-rr99.6%

    \[\leadsto \sin \varepsilon \cdot \cos x - \sin x \cdot \color{blue}{\left({\sin \varepsilon}^{2} \cdot \frac{1}{1 + \cos \varepsilon}\right)} \]
  8. Step-by-step derivation
    1. associate-*r/99.6%

      \[\leadsto \sin \varepsilon \cdot \cos x - \sin x \cdot \color{blue}{\frac{{\sin \varepsilon}^{2} \cdot 1}{1 + \cos \varepsilon}} \]
    2. *-rgt-identity99.6%

      \[\leadsto \sin \varepsilon \cdot \cos x - \sin x \cdot \frac{\color{blue}{{\sin \varepsilon}^{2}}}{1 + \cos \varepsilon} \]
  9. Simplified99.6%

    \[\leadsto \sin \varepsilon \cdot \cos x - \sin x \cdot \color{blue}{\frac{{\sin \varepsilon}^{2}}{1 + \cos \varepsilon}} \]
  10. Taylor expanded in x around inf 99.6%

    \[\leadsto \sin \varepsilon \cdot \cos x - \color{blue}{\frac{{\sin \varepsilon}^{2} \cdot \sin x}{1 + \cos \varepsilon}} \]
  11. Step-by-step derivation
    1. *-commutative99.6%

      \[\leadsto \sin \varepsilon \cdot \cos x - \frac{\color{blue}{\sin x \cdot {\sin \varepsilon}^{2}}}{1 + \cos \varepsilon} \]
    2. *-lft-identity99.6%

      \[\leadsto \sin \varepsilon \cdot \cos x - \frac{\sin x \cdot {\sin \varepsilon}^{2}}{\color{blue}{1 \cdot \left(1 + \cos \varepsilon\right)}} \]
    3. times-frac99.6%

      \[\leadsto \sin \varepsilon \cdot \cos x - \color{blue}{\frac{\sin x}{1} \cdot \frac{{\sin \varepsilon}^{2}}{1 + \cos \varepsilon}} \]
    4. /-rgt-identity99.6%

      \[\leadsto \sin \varepsilon \cdot \cos x - \color{blue}{\sin x} \cdot \frac{{\sin \varepsilon}^{2}}{1 + \cos \varepsilon} \]
    5. unpow299.6%

      \[\leadsto \sin \varepsilon \cdot \cos x - \sin x \cdot \frac{\color{blue}{\sin \varepsilon \cdot \sin \varepsilon}}{1 + \cos \varepsilon} \]
    6. associate-*r/99.6%

      \[\leadsto \sin \varepsilon \cdot \cos x - \sin x \cdot \color{blue}{\left(\sin \varepsilon \cdot \frac{\sin \varepsilon}{1 + \cos \varepsilon}\right)} \]
    7. hang-0p-tan99.7%

      \[\leadsto \sin \varepsilon \cdot \cos x - \sin x \cdot \left(\sin \varepsilon \cdot \color{blue}{\tan \left(\frac{\varepsilon}{2}\right)}\right) \]
  12. Simplified99.7%

    \[\leadsto \sin \varepsilon \cdot \cos x - \color{blue}{\sin x \cdot \left(\sin \varepsilon \cdot \tan \left(\frac{\varepsilon}{2}\right)\right)} \]
  13. Step-by-step derivation
    1. sub-neg99.7%

      \[\leadsto \color{blue}{\sin \varepsilon \cdot \cos x + \left(-\sin x \cdot \left(\sin \varepsilon \cdot \tan \left(\frac{\varepsilon}{2}\right)\right)\right)} \]
    2. *-commutative99.7%

      \[\leadsto \sin \varepsilon \cdot \cos x + \left(-\color{blue}{\left(\sin \varepsilon \cdot \tan \left(\frac{\varepsilon}{2}\right)\right) \cdot \sin x}\right) \]
    3. distribute-rgt-neg-in99.7%

      \[\leadsto \sin \varepsilon \cdot \cos x + \color{blue}{\left(\sin \varepsilon \cdot \tan \left(\frac{\varepsilon}{2}\right)\right) \cdot \left(-\sin x\right)} \]
    4. div-inv99.7%

      \[\leadsto \sin \varepsilon \cdot \cos x + \left(\sin \varepsilon \cdot \tan \color{blue}{\left(\varepsilon \cdot \frac{1}{2}\right)}\right) \cdot \left(-\sin x\right) \]
    5. metadata-eval99.7%

      \[\leadsto \sin \varepsilon \cdot \cos x + \left(\sin \varepsilon \cdot \tan \left(\varepsilon \cdot \color{blue}{0.5}\right)\right) \cdot \left(-\sin x\right) \]
  14. Applied egg-rr99.7%

    \[\leadsto \color{blue}{\sin \varepsilon \cdot \cos x + \left(\sin \varepsilon \cdot \tan \left(\varepsilon \cdot 0.5\right)\right) \cdot \left(-\sin x\right)} \]
  15. Step-by-step derivation
    1. associate-*l*99.7%

      \[\leadsto \sin \varepsilon \cdot \cos x + \color{blue}{\sin \varepsilon \cdot \left(\tan \left(\varepsilon \cdot 0.5\right) \cdot \left(-\sin x\right)\right)} \]
    2. distribute-lft-out99.7%

      \[\leadsto \color{blue}{\sin \varepsilon \cdot \left(\cos x + \tan \left(\varepsilon \cdot 0.5\right) \cdot \left(-\sin x\right)\right)} \]
  16. Simplified99.7%

    \[\leadsto \color{blue}{\sin \varepsilon \cdot \left(\cos x + \tan \left(\varepsilon \cdot 0.5\right) \cdot \left(-\sin x\right)\right)} \]
  17. Final simplification99.7%

    \[\leadsto \sin \varepsilon \cdot \left(\cos x - \tan \left(\varepsilon \cdot 0.5\right) \cdot \sin x\right) \]

Alternative 2: 76.2% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sin \left(\varepsilon + x\right)\\ t_1 := t_0 - \sin x\\ \mathbf{if}\;t_1 \leq -0.005:\\ \;\;\;\;\sin \varepsilon\\ \mathbf{elif}\;t_1 \leq 2 \cdot 10^{-19}:\\ \;\;\;\;\cos x \cdot \left(2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left|t_0\right|\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (sin (+ eps x))) (t_1 (- t_0 (sin x))))
   (if (<= t_1 -0.005)
     (sin eps)
     (if (<= t_1 2e-19) (* (cos x) (* 2.0 (sin (* eps 0.5)))) (fabs t_0)))))
double code(double x, double eps) {
	double t_0 = sin((eps + x));
	double t_1 = t_0 - sin(x);
	double tmp;
	if (t_1 <= -0.005) {
		tmp = sin(eps);
	} else if (t_1 <= 2e-19) {
		tmp = cos(x) * (2.0 * sin((eps * 0.5)));
	} else {
		tmp = fabs(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 = sin((eps + x))
    t_1 = t_0 - sin(x)
    if (t_1 <= (-0.005d0)) then
        tmp = sin(eps)
    else if (t_1 <= 2d-19) then
        tmp = cos(x) * (2.0d0 * sin((eps * 0.5d0)))
    else
        tmp = abs(t_0)
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double t_0 = Math.sin((eps + x));
	double t_1 = t_0 - Math.sin(x);
	double tmp;
	if (t_1 <= -0.005) {
		tmp = Math.sin(eps);
	} else if (t_1 <= 2e-19) {
		tmp = Math.cos(x) * (2.0 * Math.sin((eps * 0.5)));
	} else {
		tmp = Math.abs(t_0);
	}
	return tmp;
}
def code(x, eps):
	t_0 = math.sin((eps + x))
	t_1 = t_0 - math.sin(x)
	tmp = 0
	if t_1 <= -0.005:
		tmp = math.sin(eps)
	elif t_1 <= 2e-19:
		tmp = math.cos(x) * (2.0 * math.sin((eps * 0.5)))
	else:
		tmp = math.fabs(t_0)
	return tmp
function code(x, eps)
	t_0 = sin(Float64(eps + x))
	t_1 = Float64(t_0 - sin(x))
	tmp = 0.0
	if (t_1 <= -0.005)
		tmp = sin(eps);
	elseif (t_1 <= 2e-19)
		tmp = Float64(cos(x) * Float64(2.0 * sin(Float64(eps * 0.5))));
	else
		tmp = abs(t_0);
	end
	return tmp
end
function tmp_2 = code(x, eps)
	t_0 = sin((eps + x));
	t_1 = t_0 - sin(x);
	tmp = 0.0;
	if (t_1 <= -0.005)
		tmp = sin(eps);
	elseif (t_1 <= 2e-19)
		tmp = cos(x) * (2.0 * sin((eps * 0.5)));
	else
		tmp = abs(t_0);
	end
	tmp_2 = tmp;
end
code[x_, eps_] := Block[{t$95$0 = N[Sin[N[(eps + x), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(t$95$0 - N[Sin[x], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, -0.005], N[Sin[eps], $MachinePrecision], If[LessEqual[t$95$1, 2e-19], N[(N[Cos[x], $MachinePrecision] * N[(2.0 * N[Sin[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[Abs[t$95$0], $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sin \left(\varepsilon + x\right)\\
t_1 := t_0 - \sin x\\
\mathbf{if}\;t_1 \leq -0.005:\\
\;\;\;\;\sin \varepsilon\\

\mathbf{elif}\;t_1 \leq 2 \cdot 10^{-19}:\\
\;\;\;\;\cos x \cdot \left(2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)\\

\mathbf{else}:\\
\;\;\;\;\left|t_0\right|\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (-.f64 (sin.f64 (+.f64 x eps)) (sin.f64 x)) < -0.0050000000000000001

    1. Initial program 63.1%

      \[\sin \left(x + \varepsilon\right) - \sin x \]
    2. Taylor expanded in x around 0 63.7%

      \[\leadsto \color{blue}{\sin \varepsilon} \]

    if -0.0050000000000000001 < (-.f64 (sin.f64 (+.f64 x eps)) (sin.f64 x)) < 2e-19

    1. Initial program 29.6%

      \[\sin \left(x + \varepsilon\right) - \sin x \]
    2. Step-by-step derivation
      1. diff-sin29.6%

        \[\leadsto \color{blue}{2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \cos \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
      2. div-inv29.6%

        \[\leadsto 2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \cos \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      3. associate--l+29.6%

        \[\leadsto 2 \cdot \left(\sin \left(\color{blue}{\left(x + \left(\varepsilon - x\right)\right)} \cdot \frac{1}{2}\right) \cdot \cos \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      4. metadata-eval29.6%

        \[\leadsto 2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot \color{blue}{0.5}\right) \cdot \cos \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
      5. div-inv29.6%

        \[\leadsto 2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \cos \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
      6. +-commutative29.6%

        \[\leadsto 2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \cos \left(\left(\color{blue}{\left(\varepsilon + x\right)} + x\right) \cdot \frac{1}{2}\right)\right) \]
      7. associate-+l+29.6%

        \[\leadsto 2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \cos \left(\color{blue}{\left(\varepsilon + \left(x + x\right)\right)} \cdot \frac{1}{2}\right)\right) \]
      8. metadata-eval29.6%

        \[\leadsto 2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \cos \left(\left(\varepsilon + \left(x + x\right)\right) \cdot \color{blue}{0.5}\right)\right) \]
    3. Applied egg-rr29.6%

      \[\leadsto \color{blue}{2 \cdot \left(\sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right) \cdot \cos \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)\right)} \]
    4. Step-by-step derivation
      1. associate-*r*29.6%

        \[\leadsto \color{blue}{\left(2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \cdot \cos \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right)} \]
      2. *-commutative29.6%

        \[\leadsto \color{blue}{\cos \left(\left(\varepsilon + \left(x + x\right)\right) \cdot 0.5\right) \cdot \left(2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right)} \]
      3. *-commutative29.6%

        \[\leadsto \cos \color{blue}{\left(0.5 \cdot \left(\varepsilon + \left(x + x\right)\right)\right)} \cdot \left(2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      4. +-commutative29.6%

        \[\leadsto \cos \left(0.5 \cdot \color{blue}{\left(\left(x + x\right) + \varepsilon\right)}\right) \cdot \left(2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      5. count-229.6%

        \[\leadsto \cos \left(0.5 \cdot \left(\color{blue}{2 \cdot x} + \varepsilon\right)\right) \cdot \left(2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      6. fma-def29.6%

        \[\leadsto \cos \left(0.5 \cdot \color{blue}{\mathsf{fma}\left(2, x, \varepsilon\right)}\right) \cdot \left(2 \cdot \sin \left(\left(x + \left(\varepsilon - x\right)\right) \cdot 0.5\right)\right) \]
      7. sub-neg29.6%

        \[\leadsto \cos \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(2 \cdot \sin \left(\left(x + \color{blue}{\left(\varepsilon + \left(-x\right)\right)}\right) \cdot 0.5\right)\right) \]
      8. mul-1-neg29.6%

        \[\leadsto \cos \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(2 \cdot \sin \left(\left(x + \left(\varepsilon + \color{blue}{-1 \cdot x}\right)\right) \cdot 0.5\right)\right) \]
      9. +-commutative29.6%

        \[\leadsto \cos \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(2 \cdot \sin \left(\left(x + \color{blue}{\left(-1 \cdot x + \varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      10. associate-+r+81.2%

        \[\leadsto \cos \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(2 \cdot \sin \left(\color{blue}{\left(\left(x + -1 \cdot x\right) + \varepsilon\right)} \cdot 0.5\right)\right) \]
      11. mul-1-neg81.2%

        \[\leadsto \cos \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(2 \cdot \sin \left(\left(\left(x + \color{blue}{\left(-x\right)}\right) + \varepsilon\right) \cdot 0.5\right)\right) \]
      12. sub-neg81.2%

        \[\leadsto \cos \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(2 \cdot \sin \left(\left(\color{blue}{\left(x - x\right)} + \varepsilon\right) \cdot 0.5\right)\right) \]
      13. +-inverses81.2%

        \[\leadsto \cos \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(2 \cdot \sin \left(\left(\color{blue}{0} + \varepsilon\right) \cdot 0.5\right)\right) \]
      14. remove-double-neg81.2%

        \[\leadsto \cos \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(2 \cdot \sin \left(\left(0 + \color{blue}{\left(-\left(-\varepsilon\right)\right)}\right) \cdot 0.5\right)\right) \]
      15. mul-1-neg81.2%

        \[\leadsto \cos \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(2 \cdot \sin \left(\left(0 + \left(-\color{blue}{-1 \cdot \varepsilon}\right)\right) \cdot 0.5\right)\right) \]
      16. sub-neg81.2%

        \[\leadsto \cos \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(2 \cdot \sin \left(\color{blue}{\left(0 - -1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      17. neg-sub081.2%

        \[\leadsto \cos \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(2 \cdot \sin \left(\color{blue}{\left(--1 \cdot \varepsilon\right)} \cdot 0.5\right)\right) \]
      18. mul-1-neg81.2%

        \[\leadsto \cos \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(2 \cdot \sin \left(\left(-\color{blue}{\left(-\varepsilon\right)}\right) \cdot 0.5\right)\right) \]
      19. remove-double-neg81.2%

        \[\leadsto \cos \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(2 \cdot \sin \left(\color{blue}{\varepsilon} \cdot 0.5\right)\right) \]
    5. Simplified81.2%

      \[\leadsto \color{blue}{\cos \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right) \cdot \left(2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)} \]
    6. Taylor expanded in eps around 0 81.2%

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

    if 2e-19 < (-.f64 (sin.f64 (+.f64 x eps)) (sin.f64 x))

    1. Initial program 67.7%

      \[\sin \left(x + \varepsilon\right) - \sin x \]
    2. Step-by-step derivation
      1. add-cube-cbrt66.2%

        \[\leadsto \color{blue}{\left(\sqrt[3]{\sin \left(x + \varepsilon\right)} \cdot \sqrt[3]{\sin \left(x + \varepsilon\right)}\right) \cdot \sqrt[3]{\sin \left(x + \varepsilon\right)}} - \sin x \]
      2. pow366.2%

        \[\leadsto \color{blue}{{\left(\sqrt[3]{\sin \left(x + \varepsilon\right)}\right)}^{3}} - \sin x \]
    3. Applied egg-rr66.2%

      \[\leadsto \color{blue}{{\left(\sqrt[3]{\sin \left(x + \varepsilon\right)}\right)}^{3}} - \sin x \]
    4. Step-by-step derivation
      1. rem-cube-cbrt67.7%

        \[\leadsto \color{blue}{\sin \left(x + \varepsilon\right)} - \sin x \]
      2. add-sqr-sqrt65.1%

        \[\leadsto \color{blue}{\sqrt{\sin \left(x + \varepsilon\right)} \cdot \sqrt{\sin \left(x + \varepsilon\right)}} - \sin x \]
      3. sqrt-unprod67.8%

        \[\leadsto \color{blue}{\sqrt{\sin \left(x + \varepsilon\right) \cdot \sin \left(x + \varepsilon\right)}} - \sin x \]
      4. pow267.8%

        \[\leadsto \sqrt{\color{blue}{{\sin \left(x + \varepsilon\right)}^{2}}} - \sin x \]
      5. +-commutative67.8%

        \[\leadsto \sqrt{{\sin \color{blue}{\left(\varepsilon + x\right)}}^{2}} - \sin x \]
    5. Applied egg-rr67.8%

      \[\leadsto \color{blue}{\sqrt{{\sin \left(\varepsilon + x\right)}^{2}}} - \sin x \]
    6. Step-by-step derivation
      1. unpow267.8%

        \[\leadsto \sqrt{\color{blue}{\sin \left(\varepsilon + x\right) \cdot \sin \left(\varepsilon + x\right)}} - \sin x \]
      2. rem-sqrt-square67.8%

        \[\leadsto \color{blue}{\left|\sin \left(\varepsilon + x\right)\right|} - \sin x \]
    7. Simplified67.8%

      \[\leadsto \color{blue}{\left|\sin \left(\varepsilon + x\right)\right|} - \sin x \]
    8. Taylor expanded in x around 0 67.8%

      \[\leadsto \color{blue}{\left|\sin \left(\varepsilon + x\right)\right|} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification74.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\sin \left(\varepsilon + x\right) - \sin x \leq -0.005:\\ \;\;\;\;\sin \varepsilon\\ \mathbf{elif}\;\sin \left(\varepsilon + x\right) - \sin x \leq 2 \cdot 10^{-19}:\\ \;\;\;\;\cos x \cdot \left(2 \cdot \sin \left(\varepsilon \cdot 0.5\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left|\sin \left(\varepsilon + x\right)\right|\\ \end{array} \]

Alternative 3: 99.4% accurate, 0.5× speedup?

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

\\
\sin \varepsilon \cdot \cos x - \sin x \cdot \left(1 - \cos \varepsilon\right)
\end{array}
Derivation
  1. Initial program 44.8%

    \[\sin \left(x + \varepsilon\right) - \sin x \]
  2. Step-by-step derivation
    1. sin-sum71.0%

      \[\leadsto \color{blue}{\left(\sin x \cdot \cos \varepsilon + \cos x \cdot \sin \varepsilon\right)} - \sin x \]
    2. associate--l+71.0%

      \[\leadsto \color{blue}{\sin x \cdot \cos \varepsilon + \left(\cos x \cdot \sin \varepsilon - \sin x\right)} \]
  3. Applied egg-rr71.0%

    \[\leadsto \color{blue}{\sin x \cdot \cos \varepsilon + \left(\cos x \cdot \sin \varepsilon - \sin x\right)} \]
  4. Step-by-step derivation
    1. +-commutative71.0%

      \[\leadsto \color{blue}{\left(\cos x \cdot \sin \varepsilon - \sin x\right) + \sin x \cdot \cos \varepsilon} \]
    2. associate-+l-99.3%

      \[\leadsto \color{blue}{\cos x \cdot \sin \varepsilon - \left(\sin x - \sin x \cdot \cos \varepsilon\right)} \]
    3. *-commutative99.3%

      \[\leadsto \color{blue}{\sin \varepsilon \cdot \cos x} - \left(\sin x - \sin x \cdot \cos \varepsilon\right) \]
    4. *-rgt-identity99.3%

      \[\leadsto \sin \varepsilon \cdot \cos x - \left(\color{blue}{\sin x \cdot 1} - \sin x \cdot \cos \varepsilon\right) \]
    5. distribute-lft-out--99.4%

      \[\leadsto \sin \varepsilon \cdot \cos x - \color{blue}{\sin x \cdot \left(1 - \cos \varepsilon\right)} \]
  5. Simplified99.4%

    \[\leadsto \color{blue}{\sin \varepsilon \cdot \cos x - \sin x \cdot \left(1 - \cos \varepsilon\right)} \]
  6. Final simplification99.4%

    \[\leadsto \sin \varepsilon \cdot \cos x - \sin x \cdot \left(1 - \cos \varepsilon\right) \]

Alternative 4: 76.0% accurate, 0.9× speedup?

\[\begin{array}{l} \\ 2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \cos \left(0.5 \cdot \left(x + \left(\varepsilon + x\right)\right)\right)\right) \end{array} \]
(FPCore (x eps)
 :precision binary64
 (* 2.0 (* (sin (* 0.5 (+ eps (- x x)))) (cos (* 0.5 (+ x (+ eps x)))))))
double code(double x, double eps) {
	return 2.0 * (sin((0.5 * (eps + (x - x)))) * cos((0.5 * (x + (eps + x)))));
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = 2.0d0 * (sin((0.5d0 * (eps + (x - x)))) * cos((0.5d0 * (x + (eps + x)))))
end function
public static double code(double x, double eps) {
	return 2.0 * (Math.sin((0.5 * (eps + (x - x)))) * Math.cos((0.5 * (x + (eps + x)))));
}
def code(x, eps):
	return 2.0 * (math.sin((0.5 * (eps + (x - x)))) * math.cos((0.5 * (x + (eps + x)))))
function code(x, eps)
	return Float64(2.0 * Float64(sin(Float64(0.5 * Float64(eps + Float64(x - x)))) * cos(Float64(0.5 * Float64(x + Float64(eps + x))))))
end
function tmp = code(x, eps)
	tmp = 2.0 * (sin((0.5 * (eps + (x - x)))) * cos((0.5 * (x + (eps + x)))));
end
code[x_, eps_] := N[(2.0 * N[(N[Sin[N[(0.5 * N[(eps + N[(x - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[Cos[N[(0.5 * N[(x + N[(eps + x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \cos \left(0.5 \cdot \left(x + \left(\varepsilon + x\right)\right)\right)\right)
\end{array}
Derivation
  1. Initial program 44.8%

    \[\sin \left(x + \varepsilon\right) - \sin x \]
  2. Step-by-step derivation
    1. add-sqr-sqrt22.2%

      \[\leadsto \color{blue}{\sqrt{\sin \left(x + \varepsilon\right) - \sin x} \cdot \sqrt{\sin \left(x + \varepsilon\right) - \sin x}} \]
    2. sqrt-unprod22.0%

      \[\leadsto \color{blue}{\sqrt{\left(\sin \left(x + \varepsilon\right) - \sin x\right) \cdot \left(\sin \left(x + \varepsilon\right) - \sin x\right)}} \]
    3. pow222.0%

      \[\leadsto \sqrt{\color{blue}{{\left(\sin \left(x + \varepsilon\right) - \sin x\right)}^{2}}} \]
  3. Applied egg-rr22.0%

    \[\leadsto \color{blue}{\sqrt{{\left(\sin \left(x + \varepsilon\right) - \sin x\right)}^{2}}} \]
  4. Step-by-step derivation
    1. sqrt-pow144.8%

      \[\leadsto \color{blue}{{\left(\sin \left(x + \varepsilon\right) - \sin x\right)}^{\left(\frac{2}{2}\right)}} \]
    2. metadata-eval44.8%

      \[\leadsto {\left(\sin \left(x + \varepsilon\right) - \sin x\right)}^{\color{blue}{1}} \]
    3. pow144.8%

      \[\leadsto \color{blue}{\sin \left(x + \varepsilon\right) - \sin x} \]
    4. diff-sin44.2%

      \[\leadsto \color{blue}{2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \cos \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
    5. div-inv44.2%

      \[\leadsto 2 \cdot \left(\sin \color{blue}{\left(\left(\left(x + \varepsilon\right) - x\right) \cdot \frac{1}{2}\right)} \cdot \cos \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
    6. +-commutative44.2%

      \[\leadsto 2 \cdot \left(\sin \left(\left(\color{blue}{\left(\varepsilon + x\right)} - x\right) \cdot \frac{1}{2}\right) \cdot \cos \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
    7. metadata-eval44.2%

      \[\leadsto 2 \cdot \left(\sin \left(\left(\left(\varepsilon + x\right) - x\right) \cdot \color{blue}{0.5}\right) \cdot \cos \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
    8. div-inv44.2%

      \[\leadsto 2 \cdot \left(\sin \left(\left(\left(\varepsilon + x\right) - x\right) \cdot 0.5\right) \cdot \cos \color{blue}{\left(\left(\left(x + \varepsilon\right) + x\right) \cdot \frac{1}{2}\right)}\right) \]
    9. +-commutative44.2%

      \[\leadsto 2 \cdot \left(\sin \left(\left(\left(\varepsilon + x\right) - x\right) \cdot 0.5\right) \cdot \cos \left(\left(\color{blue}{\left(\varepsilon + x\right)} + x\right) \cdot \frac{1}{2}\right)\right) \]
    10. metadata-eval44.2%

      \[\leadsto 2 \cdot \left(\sin \left(\left(\left(\varepsilon + x\right) - x\right) \cdot 0.5\right) \cdot \cos \left(\left(\left(\varepsilon + x\right) + x\right) \cdot \color{blue}{0.5}\right)\right) \]
  5. Applied egg-rr44.2%

    \[\leadsto \color{blue}{2 \cdot \left(\sin \left(\left(\left(\varepsilon + x\right) - x\right) \cdot 0.5\right) \cdot \cos \left(\left(\left(\varepsilon + x\right) + x\right) \cdot 0.5\right)\right)} \]
  6. Step-by-step derivation
    1. *-commutative44.2%

      \[\leadsto 2 \cdot \left(\sin \color{blue}{\left(0.5 \cdot \left(\left(\varepsilon + x\right) - x\right)\right)} \cdot \cos \left(\left(\left(\varepsilon + x\right) + x\right) \cdot 0.5\right)\right) \]
    2. associate--l+74.2%

      \[\leadsto 2 \cdot \left(\sin \left(0.5 \cdot \color{blue}{\left(\varepsilon + \left(x - x\right)\right)}\right) \cdot \cos \left(\left(\left(\varepsilon + x\right) + x\right) \cdot 0.5\right)\right) \]
    3. *-commutative74.2%

      \[\leadsto 2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \cos \color{blue}{\left(0.5 \cdot \left(\left(\varepsilon + x\right) + x\right)\right)}\right) \]
    4. +-commutative74.2%

      \[\leadsto 2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \cos \left(0.5 \cdot \color{blue}{\left(x + \left(\varepsilon + x\right)\right)}\right)\right) \]
  7. Simplified74.2%

    \[\leadsto \color{blue}{2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \cos \left(0.5 \cdot \left(x + \left(\varepsilon + x\right)\right)\right)\right)} \]
  8. Final simplification74.2%

    \[\leadsto 2 \cdot \left(\sin \left(0.5 \cdot \left(\varepsilon + \left(x - x\right)\right)\right) \cdot \cos \left(0.5 \cdot \left(x + \left(\varepsilon + x\right)\right)\right)\right) \]

Alternative 5: 76.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(2 \cdot \sin \left(\frac{\varepsilon}{2}\right)\right) \cdot \cos \left(\frac{\varepsilon + x \cdot 2}{2}\right) \end{array} \]
(FPCore (x eps)
 :precision binary64
 (* (* 2.0 (sin (/ eps 2.0))) (cos (/ (+ eps (* x 2.0)) 2.0))))
double code(double x, double eps) {
	return (2.0 * sin((eps / 2.0))) * cos(((eps + (x * 2.0)) / 2.0));
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = (2.0d0 * sin((eps / 2.0d0))) * cos(((eps + (x * 2.0d0)) / 2.0d0))
end function
public static double code(double x, double eps) {
	return (2.0 * Math.sin((eps / 2.0))) * Math.cos(((eps + (x * 2.0)) / 2.0));
}
def code(x, eps):
	return (2.0 * math.sin((eps / 2.0))) * math.cos(((eps + (x * 2.0)) / 2.0))
function code(x, eps)
	return Float64(Float64(2.0 * sin(Float64(eps / 2.0))) * cos(Float64(Float64(eps + Float64(x * 2.0)) / 2.0)))
end
function tmp = code(x, eps)
	tmp = (2.0 * sin((eps / 2.0))) * cos(((eps + (x * 2.0)) / 2.0));
end
code[x_, eps_] := N[(N[(2.0 * N[Sin[N[(eps / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[Cos[N[(N[(eps + N[(x * 2.0), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(2 \cdot \sin \left(\frac{\varepsilon}{2}\right)\right) \cdot \cos \left(\frac{\varepsilon + x \cdot 2}{2}\right)
\end{array}
Derivation
  1. Initial program 44.8%

    \[\sin \left(x + \varepsilon\right) - \sin x \]
  2. Step-by-step derivation
    1. add-cube-cbrt43.6%

      \[\leadsto \color{blue}{\left(\sqrt[3]{\sin \left(x + \varepsilon\right)} \cdot \sqrt[3]{\sin \left(x + \varepsilon\right)}\right) \cdot \sqrt[3]{\sin \left(x + \varepsilon\right)}} - \sin x \]
    2. pow343.5%

      \[\leadsto \color{blue}{{\left(\sqrt[3]{\sin \left(x + \varepsilon\right)}\right)}^{3}} - \sin x \]
  3. Applied egg-rr43.5%

    \[\leadsto \color{blue}{{\left(\sqrt[3]{\sin \left(x + \varepsilon\right)}\right)}^{3}} - \sin x \]
  4. Step-by-step derivation
    1. rem-cube-cbrt44.8%

      \[\leadsto \color{blue}{\sin \left(x + \varepsilon\right)} - \sin x \]
    2. diff-sin44.2%

      \[\leadsto \color{blue}{2 \cdot \left(\sin \left(\frac{\left(x + \varepsilon\right) - x}{2}\right) \cdot \cos \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right)} \]
    3. +-commutative44.2%

      \[\leadsto 2 \cdot \left(\sin \left(\frac{\color{blue}{\left(\varepsilon + x\right)} - x}{2}\right) \cdot \cos \left(\frac{\left(x + \varepsilon\right) + x}{2}\right)\right) \]
    4. +-commutative44.2%

      \[\leadsto 2 \cdot \left(\sin \left(\frac{\left(\varepsilon + x\right) - x}{2}\right) \cdot \cos \left(\frac{\color{blue}{\left(\varepsilon + x\right)} + x}{2}\right)\right) \]
  5. Applied egg-rr44.2%

    \[\leadsto \color{blue}{2 \cdot \left(\sin \left(\frac{\left(\varepsilon + x\right) - x}{2}\right) \cdot \cos \left(\frac{\left(\varepsilon + x\right) + x}{2}\right)\right)} \]
  6. Step-by-step derivation
    1. associate-*r*44.2%

      \[\leadsto \color{blue}{\left(2 \cdot \sin \left(\frac{\left(\varepsilon + x\right) - x}{2}\right)\right) \cdot \cos \left(\frac{\left(\varepsilon + x\right) + x}{2}\right)} \]
    2. associate--l+74.2%

      \[\leadsto \left(2 \cdot \sin \left(\frac{\color{blue}{\varepsilon + \left(x - x\right)}}{2}\right)\right) \cdot \cos \left(\frac{\left(\varepsilon + x\right) + x}{2}\right) \]
    3. +-inverses74.2%

      \[\leadsto \left(2 \cdot \sin \left(\frac{\varepsilon + \color{blue}{0}}{2}\right)\right) \cdot \cos \left(\frac{\left(\varepsilon + x\right) + x}{2}\right) \]
    4. associate-+l+74.1%

      \[\leadsto \left(2 \cdot \sin \left(\frac{\varepsilon + 0}{2}\right)\right) \cdot \cos \left(\frac{\color{blue}{\varepsilon + \left(x + x\right)}}{2}\right) \]
    5. count-274.1%

      \[\leadsto \left(2 \cdot \sin \left(\frac{\varepsilon + 0}{2}\right)\right) \cdot \cos \left(\frac{\varepsilon + \color{blue}{2 \cdot x}}{2}\right) \]
  7. Simplified74.1%

    \[\leadsto \color{blue}{\left(2 \cdot \sin \left(\frac{\varepsilon + 0}{2}\right)\right) \cdot \cos \left(\frac{\varepsilon + 2 \cdot x}{2}\right)} \]
  8. Final simplification74.1%

    \[\leadsto \left(2 \cdot \sin \left(\frac{\varepsilon}{2}\right)\right) \cdot \cos \left(\frac{\varepsilon + x \cdot 2}{2}\right) \]

Alternative 6: 75.9% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.76 \lor \neg \left(\varepsilon \leq 4.5 \cdot 10^{-6}\right):\\ \;\;\;\;\sin \varepsilon\\ \mathbf{else}:\\ \;\;\;\;\varepsilon \cdot \cos x\\ \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (if (or (<= eps -0.76) (not (<= eps 4.5e-6))) (sin eps) (* eps (cos x))))
double code(double x, double eps) {
	double tmp;
	if ((eps <= -0.76) || !(eps <= 4.5e-6)) {
		tmp = sin(eps);
	} else {
		tmp = eps * cos(x);
	}
	return tmp;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: tmp
    if ((eps <= (-0.76d0)) .or. (.not. (eps <= 4.5d-6))) then
        tmp = sin(eps)
    else
        tmp = eps * cos(x)
    end if
    code = tmp
end function
public static double code(double x, double eps) {
	double tmp;
	if ((eps <= -0.76) || !(eps <= 4.5e-6)) {
		tmp = Math.sin(eps);
	} else {
		tmp = eps * Math.cos(x);
	}
	return tmp;
}
def code(x, eps):
	tmp = 0
	if (eps <= -0.76) or not (eps <= 4.5e-6):
		tmp = math.sin(eps)
	else:
		tmp = eps * math.cos(x)
	return tmp
function code(x, eps)
	tmp = 0.0
	if ((eps <= -0.76) || !(eps <= 4.5e-6))
		tmp = sin(eps);
	else
		tmp = Float64(eps * cos(x));
	end
	return tmp
end
function tmp_2 = code(x, eps)
	tmp = 0.0;
	if ((eps <= -0.76) || ~((eps <= 4.5e-6)))
		tmp = sin(eps);
	else
		tmp = eps * cos(x);
	end
	tmp_2 = tmp;
end
code[x_, eps_] := If[Or[LessEqual[eps, -0.76], N[Not[LessEqual[eps, 4.5e-6]], $MachinePrecision]], N[Sin[eps], $MachinePrecision], N[(eps * N[Cos[x], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\varepsilon \leq -0.76 \lor \neg \left(\varepsilon \leq 4.5 \cdot 10^{-6}\right):\\
\;\;\;\;\sin \varepsilon\\

\mathbf{else}:\\
\;\;\;\;\varepsilon \cdot \cos x\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if eps < -0.76000000000000001 or 4.50000000000000011e-6 < eps

    1. Initial program 52.3%

      \[\sin \left(x + \varepsilon\right) - \sin x \]
    2. Taylor expanded in x around 0 53.2%

      \[\leadsto \color{blue}{\sin \varepsilon} \]

    if -0.76000000000000001 < eps < 4.50000000000000011e-6

    1. Initial program 36.0%

      \[\sin \left(x + \varepsilon\right) - \sin x \]
    2. Taylor expanded in eps around 0 98.5%

      \[\leadsto \color{blue}{\varepsilon \cdot \cos x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification74.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq -0.76 \lor \neg \left(\varepsilon \leq 4.5 \cdot 10^{-6}\right):\\ \;\;\;\;\sin \varepsilon\\ \mathbf{else}:\\ \;\;\;\;\varepsilon \cdot \cos x\\ \end{array} \]

Alternative 7: 54.8% accurate, 2.0× speedup?

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

\\
\sin \varepsilon
\end{array}
Derivation
  1. Initial program 44.8%

    \[\sin \left(x + \varepsilon\right) - \sin x \]
  2. Taylor expanded in x around 0 55.6%

    \[\leadsto \color{blue}{\sin \varepsilon} \]
  3. Final simplification55.6%

    \[\leadsto \sin \varepsilon \]

Alternative 8: 4.2% accurate, 205.0× speedup?

\[\begin{array}{l} \\ 0 \end{array} \]
(FPCore (x eps) :precision binary64 0.0)
double code(double x, double eps) {
	return 0.0;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = 0.0d0
end function
public static double code(double x, double eps) {
	return 0.0;
}
def code(x, eps):
	return 0.0
function code(x, eps)
	return 0.0
end
function tmp = code(x, eps)
	tmp = 0.0;
end
code[x_, eps_] := 0.0
\begin{array}{l}

\\
0
\end{array}
Derivation
  1. Initial program 44.8%

    \[\sin \left(x + \varepsilon\right) - \sin x \]
  2. Step-by-step derivation
    1. add-cube-cbrt43.6%

      \[\leadsto \color{blue}{\left(\sqrt[3]{\sin \left(x + \varepsilon\right)} \cdot \sqrt[3]{\sin \left(x + \varepsilon\right)}\right) \cdot \sqrt[3]{\sin \left(x + \varepsilon\right)}} - \sin x \]
    2. pow343.5%

      \[\leadsto \color{blue}{{\left(\sqrt[3]{\sin \left(x + \varepsilon\right)}\right)}^{3}} - \sin x \]
  3. Applied egg-rr43.5%

    \[\leadsto \color{blue}{{\left(\sqrt[3]{\sin \left(x + \varepsilon\right)}\right)}^{3}} - \sin x \]
  4. Taylor expanded in eps around 0 4.1%

    \[\leadsto \color{blue}{{1}^{0.3333333333333333} \cdot \sin x - \sin x} \]
  5. Step-by-step derivation
    1. pow-base-14.1%

      \[\leadsto \color{blue}{1} \cdot \sin x - \sin x \]
    2. *-lft-identity4.1%

      \[\leadsto \color{blue}{\sin x} - \sin x \]
    3. +-inverses4.1%

      \[\leadsto \color{blue}{0} \]
  6. Simplified4.1%

    \[\leadsto \color{blue}{0} \]
  7. Final simplification4.1%

    \[\leadsto 0 \]

Alternative 9: 29.0% accurate, 205.0× speedup?

\[\begin{array}{l} \\ \varepsilon \end{array} \]
(FPCore (x eps) :precision binary64 eps)
double code(double x, double eps) {
	return eps;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = eps
end function
public static double code(double x, double eps) {
	return eps;
}
def code(x, eps):
	return eps
function code(x, eps)
	return eps
end
function tmp = code(x, eps)
	tmp = eps;
end
code[x_, eps_] := eps
\begin{array}{l}

\\
\varepsilon
\end{array}
Derivation
  1. Initial program 44.8%

    \[\sin \left(x + \varepsilon\right) - \sin x \]
  2. Taylor expanded in eps around 0 47.5%

    \[\leadsto \color{blue}{\varepsilon \cdot \cos x} \]
  3. Taylor expanded in x around 0 29.0%

    \[\leadsto \color{blue}{\varepsilon} \]
  4. Final simplification29.0%

    \[\leadsto \varepsilon \]

Developer target: 99.4% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(\cos x, \sin \varepsilon, \sin x \cdot \left(\cos \varepsilon - 1\right)\right) \end{array} \]
(FPCore (x eps)
 :precision binary64
 (fma (cos x) (sin eps) (* (sin x) (- (cos eps) 1.0))))
double code(double x, double eps) {
	return fma(cos(x), sin(eps), (sin(x) * (cos(eps) - 1.0)));
}
function code(x, eps)
	return fma(cos(x), sin(eps), Float64(sin(x) * Float64(cos(eps) - 1.0)))
end
code[x_, eps_] := N[(N[Cos[x], $MachinePrecision] * N[Sin[eps], $MachinePrecision] + N[(N[Sin[x], $MachinePrecision] * N[(N[Cos[eps], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(\cos x, \sin \varepsilon, \sin x \cdot \left(\cos \varepsilon - 1\right)\right)
\end{array}

Reproduce

?
herbie shell --seed 2023301 
(FPCore (x eps)
  :name "2sin (example 3.3)"
  :precision binary64

  :herbie-target
  (fma (cos x) (sin eps) (* (sin x) (- (cos eps) 1.0)))

  (- (sin (+ x eps)) (sin x)))