Hyperbolic sine

Percentage Accurate: 54.4% → 99.7%
Time: 5.2s
Alternatives: 8
Speedup: 18.7×

Specification

?
\[\begin{array}{l} \\ \frac{e^{x} - e^{-x}}{2} \end{array} \]
(FPCore (x) :precision binary64 (/ (- (exp x) (exp (- x))) 2.0))
double code(double x) {
	return (exp(x) - exp(-x)) / 2.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (exp(x) - exp(-x)) / 2.0d0
end function
public static double code(double x) {
	return (Math.exp(x) - Math.exp(-x)) / 2.0;
}
def code(x):
	return (math.exp(x) - math.exp(-x)) / 2.0
function code(x)
	return Float64(Float64(exp(x) - exp(Float64(-x))) / 2.0)
end
function tmp = code(x)
	tmp = (exp(x) - exp(-x)) / 2.0;
end
code[x_] := N[(N[(N[Exp[x], $MachinePrecision] - N[Exp[(-x)], $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision]
\begin{array}{l}

\\
\frac{e^{x} - e^{-x}}{2}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 8 alternatives:

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

Initial Program: 54.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{e^{x} - e^{-x}}{2} \end{array} \]
(FPCore (x) :precision binary64 (/ (- (exp x) (exp (- x))) 2.0))
double code(double x) {
	return (exp(x) - exp(-x)) / 2.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (exp(x) - exp(-x)) / 2.0d0
end function
public static double code(double x) {
	return (Math.exp(x) - Math.exp(-x)) / 2.0;
}
def code(x):
	return (math.exp(x) - math.exp(-x)) / 2.0
function code(x)
	return Float64(Float64(exp(x) - exp(Float64(-x))) / 2.0)
end
function tmp = code(x)
	tmp = (exp(x) - exp(-x)) / 2.0;
end
code[x_] := N[(N[(N[Exp[x], $MachinePrecision] - N[Exp[(-x)], $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision]
\begin{array}{l}

\\
\frac{e^{x} - e^{-x}}{2}
\end{array}

Alternative 1: 99.7% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := e^{x} - e^{-x}\\ \mathbf{if}\;t_0 \leq -\infty \lor \neg \left(t_0 \leq 2 \cdot 10^{-5}\right):\\ \;\;\;\;\frac{t_0}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{x \cdot 2 + 0.3333333333333333 \cdot \left(x \cdot \left(x \cdot x\right)\right)}{2}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (- (exp x) (exp (- x)))))
   (if (or (<= t_0 (- INFINITY)) (not (<= t_0 2e-5)))
     (/ t_0 2.0)
     (/ (+ (* x 2.0) (* 0.3333333333333333 (* x (* x x)))) 2.0))))
double code(double x) {
	double t_0 = exp(x) - exp(-x);
	double tmp;
	if ((t_0 <= -((double) INFINITY)) || !(t_0 <= 2e-5)) {
		tmp = t_0 / 2.0;
	} else {
		tmp = ((x * 2.0) + (0.3333333333333333 * (x * (x * x)))) / 2.0;
	}
	return tmp;
}
public static double code(double x) {
	double t_0 = Math.exp(x) - Math.exp(-x);
	double tmp;
	if ((t_0 <= -Double.POSITIVE_INFINITY) || !(t_0 <= 2e-5)) {
		tmp = t_0 / 2.0;
	} else {
		tmp = ((x * 2.0) + (0.3333333333333333 * (x * (x * x)))) / 2.0;
	}
	return tmp;
}
def code(x):
	t_0 = math.exp(x) - math.exp(-x)
	tmp = 0
	if (t_0 <= -math.inf) or not (t_0 <= 2e-5):
		tmp = t_0 / 2.0
	else:
		tmp = ((x * 2.0) + (0.3333333333333333 * (x * (x * x)))) / 2.0
	return tmp
function code(x)
	t_0 = Float64(exp(x) - exp(Float64(-x)))
	tmp = 0.0
	if ((t_0 <= Float64(-Inf)) || !(t_0 <= 2e-5))
		tmp = Float64(t_0 / 2.0);
	else
		tmp = Float64(Float64(Float64(x * 2.0) + Float64(0.3333333333333333 * Float64(x * Float64(x * x)))) / 2.0);
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = exp(x) - exp(-x);
	tmp = 0.0;
	if ((t_0 <= -Inf) || ~((t_0 <= 2e-5)))
		tmp = t_0 / 2.0;
	else
		tmp = ((x * 2.0) + (0.3333333333333333 * (x * (x * x)))) / 2.0;
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(N[Exp[x], $MachinePrecision] - N[Exp[(-x)], $MachinePrecision]), $MachinePrecision]}, If[Or[LessEqual[t$95$0, (-Infinity)], N[Not[LessEqual[t$95$0, 2e-5]], $MachinePrecision]], N[(t$95$0 / 2.0), $MachinePrecision], N[(N[(N[(x * 2.0), $MachinePrecision] + N[(0.3333333333333333 * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := e^{x} - e^{-x}\\
\mathbf{if}\;t_0 \leq -\infty \lor \neg \left(t_0 \leq 2 \cdot 10^{-5}\right):\\
\;\;\;\;\frac{t_0}{2}\\

\mathbf{else}:\\
\;\;\;\;\frac{x \cdot 2 + 0.3333333333333333 \cdot \left(x \cdot \left(x \cdot x\right)\right)}{2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (exp.f64 x) (exp.f64 (neg.f64 x))) < -inf.0 or 2.00000000000000016e-5 < (-.f64 (exp.f64 x) (exp.f64 (neg.f64 x)))

    1. Initial program 100.0%

      \[\frac{e^{x} - e^{-x}}{2} \]

    if -inf.0 < (-.f64 (exp.f64 x) (exp.f64 (neg.f64 x))) < 2.00000000000000016e-5

    1. Initial program 6.4%

      \[\frac{e^{x} - e^{-x}}{2} \]
    2. Taylor expanded in x around 0 100.0%

      \[\leadsto \frac{\color{blue}{2 \cdot x + 0.3333333333333333 \cdot {x}^{3}}}{2} \]
    3. Step-by-step derivation
      1. unpow3100.0%

        \[\leadsto \frac{2 \cdot x + 0.3333333333333333 \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot x\right)}}{2} \]
    4. Applied egg-rr100.0%

      \[\leadsto \frac{2 \cdot x + 0.3333333333333333 \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot x\right)}}{2} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification100.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;e^{x} - e^{-x} \leq -\infty \lor \neg \left(e^{x} - e^{-x} \leq 2 \cdot 10^{-5}\right):\\ \;\;\;\;\frac{e^{x} - e^{-x}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{x \cdot 2 + 0.3333333333333333 \cdot \left(x \cdot \left(x \cdot x\right)\right)}{2}\\ \end{array} \]

Alternative 2: 88.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 200000:\\ \;\;\;\;\frac{x \cdot 2 + 0.3333333333333333 \cdot \left(x \cdot \left(x \cdot x\right)\right)}{2}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{{x}^{6} \cdot 0.027777777777777776}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 200000.0)
   (/ (+ (* x 2.0) (* 0.3333333333333333 (* x (* x x)))) 2.0)
   (sqrt (* (pow x 6.0) 0.027777777777777776))))
double code(double x) {
	double tmp;
	if (x <= 200000.0) {
		tmp = ((x * 2.0) + (0.3333333333333333 * (x * (x * x)))) / 2.0;
	} else {
		tmp = sqrt((pow(x, 6.0) * 0.027777777777777776));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 200000.0d0) then
        tmp = ((x * 2.0d0) + (0.3333333333333333d0 * (x * (x * x)))) / 2.0d0
    else
        tmp = sqrt(((x ** 6.0d0) * 0.027777777777777776d0))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 200000.0) {
		tmp = ((x * 2.0) + (0.3333333333333333 * (x * (x * x)))) / 2.0;
	} else {
		tmp = Math.sqrt((Math.pow(x, 6.0) * 0.027777777777777776));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 200000.0:
		tmp = ((x * 2.0) + (0.3333333333333333 * (x * (x * x)))) / 2.0
	else:
		tmp = math.sqrt((math.pow(x, 6.0) * 0.027777777777777776))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 200000.0)
		tmp = Float64(Float64(Float64(x * 2.0) + Float64(0.3333333333333333 * Float64(x * Float64(x * x)))) / 2.0);
	else
		tmp = sqrt(Float64((x ^ 6.0) * 0.027777777777777776));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 200000.0)
		tmp = ((x * 2.0) + (0.3333333333333333 * (x * (x * x)))) / 2.0;
	else
		tmp = sqrt(((x ^ 6.0) * 0.027777777777777776));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 200000.0], N[(N[(N[(x * 2.0), $MachinePrecision] + N[(0.3333333333333333 * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision], N[Sqrt[N[(N[Power[x, 6.0], $MachinePrecision] * 0.027777777777777776), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 200000:\\
\;\;\;\;\frac{x \cdot 2 + 0.3333333333333333 \cdot \left(x \cdot \left(x \cdot x\right)\right)}{2}\\

\mathbf{else}:\\
\;\;\;\;\sqrt{{x}^{6} \cdot 0.027777777777777776}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 2e5

    1. Initial program 30.0%

      \[\frac{e^{x} - e^{-x}}{2} \]
    2. Taylor expanded in x around 0 89.8%

      \[\leadsto \frac{\color{blue}{2 \cdot x + 0.3333333333333333 \cdot {x}^{3}}}{2} \]
    3. Step-by-step derivation
      1. unpow389.8%

        \[\leadsto \frac{2 \cdot x + 0.3333333333333333 \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot x\right)}}{2} \]
    4. Applied egg-rr89.8%

      \[\leadsto \frac{2 \cdot x + 0.3333333333333333 \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot x\right)}}{2} \]

    if 2e5 < x

    1. Initial program 100.0%

      \[\frac{e^{x} - e^{-x}}{2} \]
    2. Taylor expanded in x around 0 75.6%

      \[\leadsto \frac{\color{blue}{2 \cdot x + 0.3333333333333333 \cdot {x}^{3}}}{2} \]
    3. Step-by-step derivation
      1. unpow375.6%

        \[\leadsto \frac{2 \cdot x + 0.3333333333333333 \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot x\right)}}{2} \]
      2. associate-*r*75.6%

        \[\leadsto \frac{2 \cdot x + \color{blue}{\left(0.3333333333333333 \cdot \left(x \cdot x\right)\right) \cdot x}}{2} \]
      3. distribute-rgt-out75.6%

        \[\leadsto \frac{\color{blue}{x \cdot \left(2 + 0.3333333333333333 \cdot \left(x \cdot x\right)\right)}}{2} \]
      4. *-commutative75.6%

        \[\leadsto \frac{x \cdot \left(2 + \color{blue}{\left(x \cdot x\right) \cdot 0.3333333333333333}\right)}{2} \]
      5. +-commutative75.6%

        \[\leadsto \frac{x \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot 0.3333333333333333 + 2\right)}}{2} \]
      6. associate-*l*75.6%

        \[\leadsto \frac{x \cdot \left(\color{blue}{x \cdot \left(x \cdot 0.3333333333333333\right)} + 2\right)}{2} \]
      7. fma-def75.6%

        \[\leadsto \frac{x \cdot \color{blue}{\mathsf{fma}\left(x, x \cdot 0.3333333333333333, 2\right)}}{2} \]
    4. Simplified75.6%

      \[\leadsto \frac{\color{blue}{x \cdot \mathsf{fma}\left(x, x \cdot 0.3333333333333333, 2\right)}}{2} \]
    5. Taylor expanded in x around inf 75.6%

      \[\leadsto \frac{x \cdot \color{blue}{\left(0.3333333333333333 \cdot {x}^{2}\right)}}{2} \]
    6. Step-by-step derivation
      1. unpow275.6%

        \[\leadsto \frac{x \cdot \left(0.3333333333333333 \cdot \color{blue}{\left(x \cdot x\right)}\right)}{2} \]
      2. *-commutative75.6%

        \[\leadsto \frac{x \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot 0.3333333333333333\right)}}{2} \]
      3. associate-*r*75.6%

        \[\leadsto \frac{x \cdot \color{blue}{\left(x \cdot \left(x \cdot 0.3333333333333333\right)\right)}}{2} \]
    7. Simplified75.6%

      \[\leadsto \frac{x \cdot \color{blue}{\left(x \cdot \left(x \cdot 0.3333333333333333\right)\right)}}{2} \]
    8. Step-by-step derivation
      1. add-sqr-sqrt75.6%

        \[\leadsto \color{blue}{\sqrt{\frac{x \cdot \left(x \cdot \left(x \cdot 0.3333333333333333\right)\right)}{2}} \cdot \sqrt{\frac{x \cdot \left(x \cdot \left(x \cdot 0.3333333333333333\right)\right)}{2}}} \]
      2. sqrt-unprod88.3%

        \[\leadsto \color{blue}{\sqrt{\frac{x \cdot \left(x \cdot \left(x \cdot 0.3333333333333333\right)\right)}{2} \cdot \frac{x \cdot \left(x \cdot \left(x \cdot 0.3333333333333333\right)\right)}{2}}} \]
      3. div-inv88.3%

        \[\leadsto \sqrt{\color{blue}{\left(\left(x \cdot \left(x \cdot \left(x \cdot 0.3333333333333333\right)\right)\right) \cdot \frac{1}{2}\right)} \cdot \frac{x \cdot \left(x \cdot \left(x \cdot 0.3333333333333333\right)\right)}{2}} \]
      4. div-inv88.3%

        \[\leadsto \sqrt{\left(\left(x \cdot \left(x \cdot \left(x \cdot 0.3333333333333333\right)\right)\right) \cdot \frac{1}{2}\right) \cdot \color{blue}{\left(\left(x \cdot \left(x \cdot \left(x \cdot 0.3333333333333333\right)\right)\right) \cdot \frac{1}{2}\right)}} \]
      5. swap-sqr88.3%

        \[\leadsto \sqrt{\color{blue}{\left(\left(x \cdot \left(x \cdot \left(x \cdot 0.3333333333333333\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(x \cdot 0.3333333333333333\right)\right)\right)\right) \cdot \left(\frac{1}{2} \cdot \frac{1}{2}\right)}} \]
      6. associate-*r*88.3%

        \[\leadsto \sqrt{\left(\color{blue}{\left(\left(x \cdot x\right) \cdot \left(x \cdot 0.3333333333333333\right)\right)} \cdot \left(x \cdot \left(x \cdot \left(x \cdot 0.3333333333333333\right)\right)\right)\right) \cdot \left(\frac{1}{2} \cdot \frac{1}{2}\right)} \]
      7. associate-*r*88.3%

        \[\leadsto \sqrt{\left(\color{blue}{\left(\left(\left(x \cdot x\right) \cdot x\right) \cdot 0.3333333333333333\right)} \cdot \left(x \cdot \left(x \cdot \left(x \cdot 0.3333333333333333\right)\right)\right)\right) \cdot \left(\frac{1}{2} \cdot \frac{1}{2}\right)} \]
      8. associate-*r*88.3%

        \[\leadsto \sqrt{\left(\left(\left(\left(x \cdot x\right) \cdot x\right) \cdot 0.3333333333333333\right) \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot \left(x \cdot 0.3333333333333333\right)\right)}\right) \cdot \left(\frac{1}{2} \cdot \frac{1}{2}\right)} \]
      9. associate-*r*88.3%

        \[\leadsto \sqrt{\left(\left(\left(\left(x \cdot x\right) \cdot x\right) \cdot 0.3333333333333333\right) \cdot \color{blue}{\left(\left(\left(x \cdot x\right) \cdot x\right) \cdot 0.3333333333333333\right)}\right) \cdot \left(\frac{1}{2} \cdot \frac{1}{2}\right)} \]
      10. swap-sqr88.3%

        \[\leadsto \sqrt{\color{blue}{\left(\left(\left(\left(x \cdot x\right) \cdot x\right) \cdot \left(\left(x \cdot x\right) \cdot x\right)\right) \cdot \left(0.3333333333333333 \cdot 0.3333333333333333\right)\right)} \cdot \left(\frac{1}{2} \cdot \frac{1}{2}\right)} \]
      11. pow388.3%

        \[\leadsto \sqrt{\left(\left(\color{blue}{{x}^{3}} \cdot \left(\left(x \cdot x\right) \cdot x\right)\right) \cdot \left(0.3333333333333333 \cdot 0.3333333333333333\right)\right) \cdot \left(\frac{1}{2} \cdot \frac{1}{2}\right)} \]
      12. pow388.3%

        \[\leadsto \sqrt{\left(\left({x}^{3} \cdot \color{blue}{{x}^{3}}\right) \cdot \left(0.3333333333333333 \cdot 0.3333333333333333\right)\right) \cdot \left(\frac{1}{2} \cdot \frac{1}{2}\right)} \]
      13. pow-prod-up88.3%

        \[\leadsto \sqrt{\left(\color{blue}{{x}^{\left(3 + 3\right)}} \cdot \left(0.3333333333333333 \cdot 0.3333333333333333\right)\right) \cdot \left(\frac{1}{2} \cdot \frac{1}{2}\right)} \]
      14. metadata-eval88.3%

        \[\leadsto \sqrt{\left({x}^{\color{blue}{6}} \cdot \left(0.3333333333333333 \cdot 0.3333333333333333\right)\right) \cdot \left(\frac{1}{2} \cdot \frac{1}{2}\right)} \]
      15. metadata-eval88.3%

        \[\leadsto \sqrt{\left({x}^{6} \cdot \color{blue}{0.1111111111111111}\right) \cdot \left(\frac{1}{2} \cdot \frac{1}{2}\right)} \]
      16. metadata-eval88.3%

        \[\leadsto \sqrt{\left({x}^{6} \cdot 0.1111111111111111\right) \cdot \left(\color{blue}{0.5} \cdot \frac{1}{2}\right)} \]
      17. metadata-eval88.3%

        \[\leadsto \sqrt{\left({x}^{6} \cdot 0.1111111111111111\right) \cdot \left(0.5 \cdot \color{blue}{0.5}\right)} \]
      18. metadata-eval88.3%

        \[\leadsto \sqrt{\left({x}^{6} \cdot 0.1111111111111111\right) \cdot \color{blue}{0.25}} \]
    9. Applied egg-rr88.3%

      \[\leadsto \color{blue}{\sqrt{\left({x}^{6} \cdot 0.1111111111111111\right) \cdot 0.25}} \]
    10. Step-by-step derivation
      1. associate-*l*88.3%

        \[\leadsto \sqrt{\color{blue}{{x}^{6} \cdot \left(0.1111111111111111 \cdot 0.25\right)}} \]
      2. metadata-eval88.3%

        \[\leadsto \sqrt{{x}^{6} \cdot \color{blue}{0.027777777777777776}} \]
    11. Simplified88.3%

      \[\leadsto \color{blue}{\sqrt{{x}^{6} \cdot 0.027777777777777776}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification89.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 200000:\\ \;\;\;\;\frac{x \cdot 2 + 0.3333333333333333 \cdot \left(x \cdot \left(x \cdot x\right)\right)}{2}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{{x}^{6} \cdot 0.027777777777777776}\\ \end{array} \]

Alternative 3: 84.5% accurate, 15.8× speedup?

\[\begin{array}{l} \\ \frac{x \cdot 2 + 0.3333333333333333 \cdot \left(x \cdot \left(x \cdot x\right)\right)}{2} \end{array} \]
(FPCore (x)
 :precision binary64
 (/ (+ (* x 2.0) (* 0.3333333333333333 (* x (* x x)))) 2.0))
double code(double x) {
	return ((x * 2.0) + (0.3333333333333333 * (x * (x * x)))) / 2.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = ((x * 2.0d0) + (0.3333333333333333d0 * (x * (x * x)))) / 2.0d0
end function
public static double code(double x) {
	return ((x * 2.0) + (0.3333333333333333 * (x * (x * x)))) / 2.0;
}
def code(x):
	return ((x * 2.0) + (0.3333333333333333 * (x * (x * x)))) / 2.0
function code(x)
	return Float64(Float64(Float64(x * 2.0) + Float64(0.3333333333333333 * Float64(x * Float64(x * x)))) / 2.0)
end
function tmp = code(x)
	tmp = ((x * 2.0) + (0.3333333333333333 * (x * (x * x)))) / 2.0;
end
code[x_] := N[(N[(N[(x * 2.0), $MachinePrecision] + N[(0.3333333333333333 * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision]
\begin{array}{l}

\\
\frac{x \cdot 2 + 0.3333333333333333 \cdot \left(x \cdot \left(x \cdot x\right)\right)}{2}
\end{array}
Derivation
  1. Initial program 48.1%

    \[\frac{e^{x} - e^{-x}}{2} \]
  2. Taylor expanded in x around 0 86.2%

    \[\leadsto \frac{\color{blue}{2 \cdot x + 0.3333333333333333 \cdot {x}^{3}}}{2} \]
  3. Step-by-step derivation
    1. unpow386.2%

      \[\leadsto \frac{2 \cdot x + 0.3333333333333333 \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot x\right)}}{2} \]
  4. Applied egg-rr86.2%

    \[\leadsto \frac{2 \cdot x + 0.3333333333333333 \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot x\right)}}{2} \]
  5. Final simplification86.2%

    \[\leadsto \frac{x \cdot 2 + 0.3333333333333333 \cdot \left(x \cdot \left(x \cdot x\right)\right)}{2} \]

Alternative 4: 84.1% accurate, 18.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -2.4 \lor \neg \left(x \leq 2.5\right):\\ \;\;\;\;x \cdot \left(x \cdot \left(x \cdot 0.16666666666666666\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{x \cdot 2}{2}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (or (<= x -2.4) (not (<= x 2.5)))
   (* x (* x (* x 0.16666666666666666)))
   (/ (* x 2.0) 2.0)))
double code(double x) {
	double tmp;
	if ((x <= -2.4) || !(x <= 2.5)) {
		tmp = x * (x * (x * 0.16666666666666666));
	} else {
		tmp = (x * 2.0) / 2.0;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if ((x <= (-2.4d0)) .or. (.not. (x <= 2.5d0))) then
        tmp = x * (x * (x * 0.16666666666666666d0))
    else
        tmp = (x * 2.0d0) / 2.0d0
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if ((x <= -2.4) || !(x <= 2.5)) {
		tmp = x * (x * (x * 0.16666666666666666));
	} else {
		tmp = (x * 2.0) / 2.0;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if (x <= -2.4) or not (x <= 2.5):
		tmp = x * (x * (x * 0.16666666666666666))
	else:
		tmp = (x * 2.0) / 2.0
	return tmp
function code(x)
	tmp = 0.0
	if ((x <= -2.4) || !(x <= 2.5))
		tmp = Float64(x * Float64(x * Float64(x * 0.16666666666666666)));
	else
		tmp = Float64(Float64(x * 2.0) / 2.0);
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if ((x <= -2.4) || ~((x <= 2.5)))
		tmp = x * (x * (x * 0.16666666666666666));
	else
		tmp = (x * 2.0) / 2.0;
	end
	tmp_2 = tmp;
end
code[x_] := If[Or[LessEqual[x, -2.4], N[Not[LessEqual[x, 2.5]], $MachinePrecision]], N[(x * N[(x * N[(x * 0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(x * 2.0), $MachinePrecision] / 2.0), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -2.4 \lor \neg \left(x \leq 2.5\right):\\
\;\;\;\;x \cdot \left(x \cdot \left(x \cdot 0.16666666666666666\right)\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{x \cdot 2}{2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -2.39999999999999991 or 2.5 < x

    1. Initial program 100.0%

      \[\frac{e^{x} - e^{-x}}{2} \]
    2. Taylor expanded in x around 0 69.2%

      \[\leadsto \frac{\color{blue}{2 \cdot x + 0.3333333333333333 \cdot {x}^{3}}}{2} \]
    3. Step-by-step derivation
      1. unpow369.2%

        \[\leadsto \frac{2 \cdot x + 0.3333333333333333 \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot x\right)}}{2} \]
      2. associate-*r*69.2%

        \[\leadsto \frac{2 \cdot x + \color{blue}{\left(0.3333333333333333 \cdot \left(x \cdot x\right)\right) \cdot x}}{2} \]
      3. distribute-rgt-out69.2%

        \[\leadsto \frac{\color{blue}{x \cdot \left(2 + 0.3333333333333333 \cdot \left(x \cdot x\right)\right)}}{2} \]
      4. *-commutative69.2%

        \[\leadsto \frac{x \cdot \left(2 + \color{blue}{\left(x \cdot x\right) \cdot 0.3333333333333333}\right)}{2} \]
      5. +-commutative69.2%

        \[\leadsto \frac{x \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot 0.3333333333333333 + 2\right)}}{2} \]
      6. associate-*l*69.2%

        \[\leadsto \frac{x \cdot \left(\color{blue}{x \cdot \left(x \cdot 0.3333333333333333\right)} + 2\right)}{2} \]
      7. fma-def69.2%

        \[\leadsto \frac{x \cdot \color{blue}{\mathsf{fma}\left(x, x \cdot 0.3333333333333333, 2\right)}}{2} \]
    4. Simplified69.2%

      \[\leadsto \frac{\color{blue}{x \cdot \mathsf{fma}\left(x, x \cdot 0.3333333333333333, 2\right)}}{2} \]
    5. Taylor expanded in x around inf 69.2%

      \[\leadsto \frac{x \cdot \color{blue}{\left(0.3333333333333333 \cdot {x}^{2}\right)}}{2} \]
    6. Step-by-step derivation
      1. unpow269.2%

        \[\leadsto \frac{x \cdot \left(0.3333333333333333 \cdot \color{blue}{\left(x \cdot x\right)}\right)}{2} \]
      2. *-commutative69.2%

        \[\leadsto \frac{x \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot 0.3333333333333333\right)}}{2} \]
      3. associate-*r*69.2%

        \[\leadsto \frac{x \cdot \color{blue}{\left(x \cdot \left(x \cdot 0.3333333333333333\right)\right)}}{2} \]
    7. Simplified69.2%

      \[\leadsto \frac{x \cdot \color{blue}{\left(x \cdot \left(x \cdot 0.3333333333333333\right)\right)}}{2} \]
    8. Step-by-step derivation
      1. associate-/l*69.2%

        \[\leadsto \color{blue}{\frac{x}{\frac{2}{x \cdot \left(x \cdot 0.3333333333333333\right)}}} \]
      2. div-inv69.2%

        \[\leadsto \color{blue}{x \cdot \frac{1}{\frac{2}{x \cdot \left(x \cdot 0.3333333333333333\right)}}} \]
      3. associate-*r*69.2%

        \[\leadsto x \cdot \frac{1}{\frac{2}{\color{blue}{\left(x \cdot x\right) \cdot 0.3333333333333333}}} \]
      4. *-commutative69.2%

        \[\leadsto x \cdot \frac{1}{\frac{2}{\color{blue}{0.3333333333333333 \cdot \left(x \cdot x\right)}}} \]
    9. Applied egg-rr69.2%

      \[\leadsto \color{blue}{x \cdot \frac{1}{\frac{2}{0.3333333333333333 \cdot \left(x \cdot x\right)}}} \]
    10. Taylor expanded in x around 0 69.2%

      \[\leadsto x \cdot \color{blue}{\left(0.16666666666666666 \cdot {x}^{2}\right)} \]
    11. Step-by-step derivation
      1. unpow269.2%

        \[\leadsto x \cdot \left(0.16666666666666666 \cdot \color{blue}{\left(x \cdot x\right)}\right) \]
      2. *-commutative69.2%

        \[\leadsto x \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot 0.16666666666666666\right)} \]
      3. associate-*l*69.2%

        \[\leadsto x \cdot \color{blue}{\left(x \cdot \left(x \cdot 0.16666666666666666\right)\right)} \]
    12. Simplified69.2%

      \[\leadsto x \cdot \color{blue}{\left(x \cdot \left(x \cdot 0.16666666666666666\right)\right)} \]

    if -2.39999999999999991 < x < 2.5

    1. Initial program 7.1%

      \[\frac{e^{x} - e^{-x}}{2} \]
    2. Taylor expanded in x around 0 99.3%

      \[\leadsto \frac{\color{blue}{2 \cdot x}}{2} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification86.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -2.4 \lor \neg \left(x \leq 2.5\right):\\ \;\;\;\;x \cdot \left(x \cdot \left(x \cdot 0.16666666666666666\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{x \cdot 2}{2}\\ \end{array} \]

Alternative 5: 84.4% accurate, 18.7× speedup?

\[\begin{array}{l} \\ \frac{x \cdot \left(2 + x \cdot \left(x \cdot 0.3333333333333333\right)\right)}{2} \end{array} \]
(FPCore (x)
 :precision binary64
 (/ (* x (+ 2.0 (* x (* x 0.3333333333333333)))) 2.0))
double code(double x) {
	return (x * (2.0 + (x * (x * 0.3333333333333333)))) / 2.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (x * (2.0d0 + (x * (x * 0.3333333333333333d0)))) / 2.0d0
end function
public static double code(double x) {
	return (x * (2.0 + (x * (x * 0.3333333333333333)))) / 2.0;
}
def code(x):
	return (x * (2.0 + (x * (x * 0.3333333333333333)))) / 2.0
function code(x)
	return Float64(Float64(x * Float64(2.0 + Float64(x * Float64(x * 0.3333333333333333)))) / 2.0)
end
function tmp = code(x)
	tmp = (x * (2.0 + (x * (x * 0.3333333333333333)))) / 2.0;
end
code[x_] := N[(N[(x * N[(2.0 + N[(x * N[(x * 0.3333333333333333), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision]
\begin{array}{l}

\\
\frac{x \cdot \left(2 + x \cdot \left(x \cdot 0.3333333333333333\right)\right)}{2}
\end{array}
Derivation
  1. Initial program 48.1%

    \[\frac{e^{x} - e^{-x}}{2} \]
  2. Taylor expanded in x around 0 86.2%

    \[\leadsto \frac{\color{blue}{2 \cdot x + 0.3333333333333333 \cdot {x}^{3}}}{2} \]
  3. Step-by-step derivation
    1. unpow386.2%

      \[\leadsto \frac{2 \cdot x + 0.3333333333333333 \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot x\right)}}{2} \]
    2. associate-*r*86.2%

      \[\leadsto \frac{2 \cdot x + \color{blue}{\left(0.3333333333333333 \cdot \left(x \cdot x\right)\right) \cdot x}}{2} \]
    3. distribute-rgt-out86.1%

      \[\leadsto \frac{\color{blue}{x \cdot \left(2 + 0.3333333333333333 \cdot \left(x \cdot x\right)\right)}}{2} \]
    4. *-commutative86.1%

      \[\leadsto \frac{x \cdot \left(2 + \color{blue}{\left(x \cdot x\right) \cdot 0.3333333333333333}\right)}{2} \]
    5. +-commutative86.1%

      \[\leadsto \frac{x \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot 0.3333333333333333 + 2\right)}}{2} \]
    6. associate-*l*86.1%

      \[\leadsto \frac{x \cdot \left(\color{blue}{x \cdot \left(x \cdot 0.3333333333333333\right)} + 2\right)}{2} \]
    7. fma-def86.1%

      \[\leadsto \frac{x \cdot \color{blue}{\mathsf{fma}\left(x, x \cdot 0.3333333333333333, 2\right)}}{2} \]
  4. Simplified86.1%

    \[\leadsto \frac{\color{blue}{x \cdot \mathsf{fma}\left(x, x \cdot 0.3333333333333333, 2\right)}}{2} \]
  5. Step-by-step derivation
    1. fma-udef86.1%

      \[\leadsto \frac{x \cdot \color{blue}{\left(x \cdot \left(x \cdot 0.3333333333333333\right) + 2\right)}}{2} \]
    2. *-commutative86.1%

      \[\leadsto \frac{x \cdot \left(x \cdot \color{blue}{\left(0.3333333333333333 \cdot x\right)} + 2\right)}{2} \]
  6. Applied egg-rr86.1%

    \[\leadsto \frac{x \cdot \color{blue}{\left(x \cdot \left(0.3333333333333333 \cdot x\right) + 2\right)}}{2} \]
  7. Final simplification86.1%

    \[\leadsto \frac{x \cdot \left(2 + x \cdot \left(x \cdot 0.3333333333333333\right)\right)}{2} \]

Alternative 6: 52.2% accurate, 41.2× speedup?

\[\begin{array}{l} \\ \frac{x \cdot 2}{2} \end{array} \]
(FPCore (x) :precision binary64 (/ (* x 2.0) 2.0))
double code(double x) {
	return (x * 2.0) / 2.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (x * 2.0d0) / 2.0d0
end function
public static double code(double x) {
	return (x * 2.0) / 2.0;
}
def code(x):
	return (x * 2.0) / 2.0
function code(x)
	return Float64(Float64(x * 2.0) / 2.0)
end
function tmp = code(x)
	tmp = (x * 2.0) / 2.0;
end
code[x_] := N[(N[(x * 2.0), $MachinePrecision] / 2.0), $MachinePrecision]
\begin{array}{l}

\\
\frac{x \cdot 2}{2}
\end{array}
Derivation
  1. Initial program 48.1%

    \[\frac{e^{x} - e^{-x}}{2} \]
  2. Taylor expanded in x around 0 58.0%

    \[\leadsto \frac{\color{blue}{2 \cdot x}}{2} \]
  3. Final simplification58.0%

    \[\leadsto \frac{x \cdot 2}{2} \]

Alternative 7: 2.9% accurate, 206.0× speedup?

\[\begin{array}{l} \\ -1 \end{array} \]
(FPCore (x) :precision binary64 -1.0)
double code(double x) {
	return -1.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = -1.0d0
end function
public static double code(double x) {
	return -1.0;
}
def code(x):
	return -1.0
function code(x)
	return -1.0
end
function tmp = code(x)
	tmp = -1.0;
end
code[x_] := -1.0
\begin{array}{l}

\\
-1
\end{array}
Derivation
  1. Initial program 48.1%

    \[\frac{e^{x} - e^{-x}}{2} \]
  2. Applied egg-rr2.9%

    \[\leadsto \frac{\color{blue}{-2}}{2} \]
  3. Final simplification2.9%

    \[\leadsto -1 \]

Alternative 8: 3.5% accurate, 206.0× speedup?

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

\\
0
\end{array}
Derivation
  1. Initial program 48.1%

    \[\frac{e^{x} - e^{-x}}{2} \]
  2. Applied egg-rr3.7%

    \[\leadsto \frac{\color{blue}{0}}{2} \]
  3. Final simplification3.7%

    \[\leadsto 0 \]

Reproduce

?
herbie shell --seed 2023217 
(FPCore (x)
  :name "Hyperbolic sine"
  :precision binary64
  (/ (- (exp x) (exp (- x))) 2.0))