expq3 (problem 3.4.2)

Percentage Accurate: 6.3% → 99.9%
Time: 17.9s
Alternatives: 8
Speedup: 107.0×

Specification

?
\[-1 < \varepsilon \land \varepsilon < 1\]
\[\begin{array}{l} \\ \frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\left(e^{a \cdot \varepsilon} - 1\right) \cdot \left(e^{b \cdot \varepsilon} - 1\right)} \end{array} \]
(FPCore (a b eps)
 :precision binary64
 (/
  (* eps (- (exp (* (+ a b) eps)) 1.0))
  (* (- (exp (* a eps)) 1.0) (- (exp (* b eps)) 1.0))))
double code(double a, double b, double eps) {
	return (eps * (exp(((a + b) * eps)) - 1.0)) / ((exp((a * eps)) - 1.0) * (exp((b * eps)) - 1.0));
}
real(8) function code(a, b, eps)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: eps
    code = (eps * (exp(((a + b) * eps)) - 1.0d0)) / ((exp((a * eps)) - 1.0d0) * (exp((b * eps)) - 1.0d0))
end function
public static double code(double a, double b, double eps) {
	return (eps * (Math.exp(((a + b) * eps)) - 1.0)) / ((Math.exp((a * eps)) - 1.0) * (Math.exp((b * eps)) - 1.0));
}
def code(a, b, eps):
	return (eps * (math.exp(((a + b) * eps)) - 1.0)) / ((math.exp((a * eps)) - 1.0) * (math.exp((b * eps)) - 1.0))
function code(a, b, eps)
	return Float64(Float64(eps * Float64(exp(Float64(Float64(a + b) * eps)) - 1.0)) / Float64(Float64(exp(Float64(a * eps)) - 1.0) * Float64(exp(Float64(b * eps)) - 1.0)))
end
function tmp = code(a, b, eps)
	tmp = (eps * (exp(((a + b) * eps)) - 1.0)) / ((exp((a * eps)) - 1.0) * (exp((b * eps)) - 1.0));
end
code[a_, b_, eps_] := N[(N[(eps * N[(N[Exp[N[(N[(a + b), $MachinePrecision] * eps), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision] / N[(N[(N[Exp[N[(a * eps), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision] * N[(N[Exp[N[(b * eps), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\left(e^{a \cdot \varepsilon} - 1\right) \cdot \left(e^{b \cdot \varepsilon} - 1\right)}
\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: 6.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\left(e^{a \cdot \varepsilon} - 1\right) \cdot \left(e^{b \cdot \varepsilon} - 1\right)} \end{array} \]
(FPCore (a b eps)
 :precision binary64
 (/
  (* eps (- (exp (* (+ a b) eps)) 1.0))
  (* (- (exp (* a eps)) 1.0) (- (exp (* b eps)) 1.0))))
double code(double a, double b, double eps) {
	return (eps * (exp(((a + b) * eps)) - 1.0)) / ((exp((a * eps)) - 1.0) * (exp((b * eps)) - 1.0));
}
real(8) function code(a, b, eps)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: eps
    code = (eps * (exp(((a + b) * eps)) - 1.0d0)) / ((exp((a * eps)) - 1.0d0) * (exp((b * eps)) - 1.0d0))
end function
public static double code(double a, double b, double eps) {
	return (eps * (Math.exp(((a + b) * eps)) - 1.0)) / ((Math.exp((a * eps)) - 1.0) * (Math.exp((b * eps)) - 1.0));
}
def code(a, b, eps):
	return (eps * (math.exp(((a + b) * eps)) - 1.0)) / ((math.exp((a * eps)) - 1.0) * (math.exp((b * eps)) - 1.0))
function code(a, b, eps)
	return Float64(Float64(eps * Float64(exp(Float64(Float64(a + b) * eps)) - 1.0)) / Float64(Float64(exp(Float64(a * eps)) - 1.0) * Float64(exp(Float64(b * eps)) - 1.0)))
end
function tmp = code(a, b, eps)
	tmp = (eps * (exp(((a + b) * eps)) - 1.0)) / ((exp((a * eps)) - 1.0) * (exp((b * eps)) - 1.0));
end
code[a_, b_, eps_] := N[(N[(eps * N[(N[Exp[N[(N[(a + b), $MachinePrecision] * eps), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision] / N[(N[(N[Exp[N[(a * eps), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision] * N[(N[Exp[N[(b * eps), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\left(e^{a \cdot \varepsilon} - 1\right) \cdot \left(e^{b \cdot \varepsilon} - 1\right)}
\end{array}

Alternative 1: 99.9% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \varepsilon \cdot \left(a + b\right)\\ t_1 := \frac{\varepsilon \cdot \left(e^{t_0} + -1\right)}{\left(e^{\varepsilon \cdot a} + -1\right) \cdot \left(e^{\varepsilon \cdot b} + -1\right)}\\ \mathbf{if}\;t_1 \leq -\infty \lor \neg \left(t_1 \leq 0.002\right):\\ \;\;\;\;\frac{1}{a} + \frac{1}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)} \cdot \frac{\mathsf{expm1}\left(t_0\right)}{\mathsf{expm1}\left(\varepsilon \cdot a\right)}\\ \end{array} \end{array} \]
(FPCore (a b eps)
 :precision binary64
 (let* ((t_0 (* eps (+ a b)))
        (t_1
         (/
          (* eps (+ (exp t_0) -1.0))
          (* (+ (exp (* eps a)) -1.0) (+ (exp (* eps b)) -1.0)))))
   (if (or (<= t_1 (- INFINITY)) (not (<= t_1 0.002)))
     (+ (/ 1.0 a) (/ 1.0 b))
     (* (/ eps (expm1 (* eps b))) (/ (expm1 t_0) (expm1 (* eps a)))))))
double code(double a, double b, double eps) {
	double t_0 = eps * (a + b);
	double t_1 = (eps * (exp(t_0) + -1.0)) / ((exp((eps * a)) + -1.0) * (exp((eps * b)) + -1.0));
	double tmp;
	if ((t_1 <= -((double) INFINITY)) || !(t_1 <= 0.002)) {
		tmp = (1.0 / a) + (1.0 / b);
	} else {
		tmp = (eps / expm1((eps * b))) * (expm1(t_0) / expm1((eps * a)));
	}
	return tmp;
}
public static double code(double a, double b, double eps) {
	double t_0 = eps * (a + b);
	double t_1 = (eps * (Math.exp(t_0) + -1.0)) / ((Math.exp((eps * a)) + -1.0) * (Math.exp((eps * b)) + -1.0));
	double tmp;
	if ((t_1 <= -Double.POSITIVE_INFINITY) || !(t_1 <= 0.002)) {
		tmp = (1.0 / a) + (1.0 / b);
	} else {
		tmp = (eps / Math.expm1((eps * b))) * (Math.expm1(t_0) / Math.expm1((eps * a)));
	}
	return tmp;
}
def code(a, b, eps):
	t_0 = eps * (a + b)
	t_1 = (eps * (math.exp(t_0) + -1.0)) / ((math.exp((eps * a)) + -1.0) * (math.exp((eps * b)) + -1.0))
	tmp = 0
	if (t_1 <= -math.inf) or not (t_1 <= 0.002):
		tmp = (1.0 / a) + (1.0 / b)
	else:
		tmp = (eps / math.expm1((eps * b))) * (math.expm1(t_0) / math.expm1((eps * a)))
	return tmp
function code(a, b, eps)
	t_0 = Float64(eps * Float64(a + b))
	t_1 = Float64(Float64(eps * Float64(exp(t_0) + -1.0)) / Float64(Float64(exp(Float64(eps * a)) + -1.0) * Float64(exp(Float64(eps * b)) + -1.0)))
	tmp = 0.0
	if ((t_1 <= Float64(-Inf)) || !(t_1 <= 0.002))
		tmp = Float64(Float64(1.0 / a) + Float64(1.0 / b));
	else
		tmp = Float64(Float64(eps / expm1(Float64(eps * b))) * Float64(expm1(t_0) / expm1(Float64(eps * a))));
	end
	return tmp
end
code[a_, b_, eps_] := Block[{t$95$0 = N[(eps * N[(a + b), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(eps * N[(N[Exp[t$95$0], $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision] / N[(N[(N[Exp[N[(eps * a), $MachinePrecision]], $MachinePrecision] + -1.0), $MachinePrecision] * N[(N[Exp[N[(eps * b), $MachinePrecision]], $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[Or[LessEqual[t$95$1, (-Infinity)], N[Not[LessEqual[t$95$1, 0.002]], $MachinePrecision]], N[(N[(1.0 / a), $MachinePrecision] + N[(1.0 / b), $MachinePrecision]), $MachinePrecision], N[(N[(eps / N[(Exp[N[(eps * b), $MachinePrecision]] - 1), $MachinePrecision]), $MachinePrecision] * N[(N[(Exp[t$95$0] - 1), $MachinePrecision] / N[(Exp[N[(eps * a), $MachinePrecision]] - 1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \varepsilon \cdot \left(a + b\right)\\
t_1 := \frac{\varepsilon \cdot \left(e^{t_0} + -1\right)}{\left(e^{\varepsilon \cdot a} + -1\right) \cdot \left(e^{\varepsilon \cdot b} + -1\right)}\\
\mathbf{if}\;t_1 \leq -\infty \lor \neg \left(t_1 \leq 0.002\right):\\
\;\;\;\;\frac{1}{a} + \frac{1}{b}\\

\mathbf{else}:\\
\;\;\;\;\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)} \cdot \frac{\mathsf{expm1}\left(t_0\right)}{\mathsf{expm1}\left(\varepsilon \cdot a\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (*.f64 eps (-.f64 (exp.f64 (*.f64 (+.f64 a b) eps)) 1)) (*.f64 (-.f64 (exp.f64 (*.f64 a eps)) 1) (-.f64 (exp.f64 (*.f64 b eps)) 1))) < -inf.0 or 2e-3 < (/.f64 (*.f64 eps (-.f64 (exp.f64 (*.f64 (+.f64 a b) eps)) 1)) (*.f64 (-.f64 (exp.f64 (*.f64 a eps)) 1) (-.f64 (exp.f64 (*.f64 b eps)) 1)))

    1. Initial program 0.5%

      \[\frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\left(e^{a \cdot \varepsilon} - 1\right) \cdot \left(e^{b \cdot \varepsilon} - 1\right)} \]
    2. Step-by-step derivation
      1. *-commutative0.5%

        \[\leadsto \frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\color{blue}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
      2. associate-*l/0.5%

        \[\leadsto \color{blue}{\frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)} \]
      3. *-commutative0.5%

        \[\leadsto \color{blue}{\left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right) \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
      4. expm1-def2.5%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\left(a + b\right) \cdot \varepsilon\right)} \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \]
      5. *-commutative2.5%

        \[\leadsto \mathsf{expm1}\left(\color{blue}{\varepsilon \cdot \left(a + b\right)}\right) \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \]
      6. associate-/r*2.5%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \color{blue}{\frac{\frac{\varepsilon}{e^{b \cdot \varepsilon} - 1}}{e^{a \cdot \varepsilon} - 1}} \]
      7. expm1-def9.4%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\color{blue}{\mathsf{expm1}\left(b \cdot \varepsilon\right)}}}{e^{a \cdot \varepsilon} - 1} \]
      8. *-commutative9.4%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot b}\right)}}{e^{a \cdot \varepsilon} - 1} \]
      9. expm1-def44.5%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\color{blue}{\mathsf{expm1}\left(a \cdot \varepsilon\right)}} \]
      10. *-commutative44.5%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot a}\right)} \]
    3. Simplified44.5%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\varepsilon \cdot a\right)}} \]
    4. Taylor expanded in eps around 0 77.8%

      \[\leadsto \color{blue}{\frac{a + b}{a \cdot b}} \]
    5. Taylor expanded in a around 0 100.0%

      \[\leadsto \color{blue}{\frac{1}{a} + \frac{1}{b}} \]

    if -inf.0 < (/.f64 (*.f64 eps (-.f64 (exp.f64 (*.f64 (+.f64 a b) eps)) 1)) (*.f64 (-.f64 (exp.f64 (*.f64 a eps)) 1) (-.f64 (exp.f64 (*.f64 b eps)) 1))) < 2e-3

    1. Initial program 88.2%

      \[\frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\left(e^{a \cdot \varepsilon} - 1\right) \cdot \left(e^{b \cdot \varepsilon} - 1\right)} \]
    2. Step-by-step derivation
      1. *-commutative88.2%

        \[\leadsto \frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\color{blue}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
      2. times-frac88.2%

        \[\leadsto \color{blue}{\frac{\varepsilon}{e^{b \cdot \varepsilon} - 1} \cdot \frac{e^{\left(a + b\right) \cdot \varepsilon} - 1}{e^{a \cdot \varepsilon} - 1}} \]
      3. +-commutative88.2%

        \[\leadsto \frac{\varepsilon}{e^{b \cdot \varepsilon} - 1} \cdot \frac{e^{\color{blue}{\left(b + a\right)} \cdot \varepsilon} - 1}{e^{a \cdot \varepsilon} - 1} \]
      4. expm1-def92.9%

        \[\leadsto \frac{\varepsilon}{\color{blue}{\mathsf{expm1}\left(b \cdot \varepsilon\right)}} \cdot \frac{e^{\left(b + a\right) \cdot \varepsilon} - 1}{e^{a \cdot \varepsilon} - 1} \]
      5. *-commutative92.9%

        \[\leadsto \frac{\varepsilon}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot b}\right)} \cdot \frac{e^{\left(b + a\right) \cdot \varepsilon} - 1}{e^{a \cdot \varepsilon} - 1} \]
      6. expm1-def93.0%

        \[\leadsto \frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)} \cdot \frac{\color{blue}{\mathsf{expm1}\left(\left(b + a\right) \cdot \varepsilon\right)}}{e^{a \cdot \varepsilon} - 1} \]
      7. +-commutative93.0%

        \[\leadsto \frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)} \cdot \frac{\mathsf{expm1}\left(\color{blue}{\left(a + b\right)} \cdot \varepsilon\right)}{e^{a \cdot \varepsilon} - 1} \]
      8. *-commutative93.0%

        \[\leadsto \frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)} \cdot \frac{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot \left(a + b\right)}\right)}{e^{a \cdot \varepsilon} - 1} \]
      9. expm1-def99.9%

        \[\leadsto \frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)} \cdot \frac{\mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right)}{\color{blue}{\mathsf{expm1}\left(a \cdot \varepsilon\right)}} \]
      10. *-commutative99.9%

        \[\leadsto \frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)} \cdot \frac{\mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right)}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot a}\right)} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)} \cdot \frac{\mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right)}{\mathsf{expm1}\left(\varepsilon \cdot a\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification100.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\varepsilon \cdot \left(e^{\varepsilon \cdot \left(a + b\right)} + -1\right)}{\left(e^{\varepsilon \cdot a} + -1\right) \cdot \left(e^{\varepsilon \cdot b} + -1\right)} \leq -\infty \lor \neg \left(\frac{\varepsilon \cdot \left(e^{\varepsilon \cdot \left(a + b\right)} + -1\right)}{\left(e^{\varepsilon \cdot a} + -1\right) \cdot \left(e^{\varepsilon \cdot b} + -1\right)} \leq 0.002\right):\\ \;\;\;\;\frac{1}{a} + \frac{1}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)} \cdot \frac{\mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right)}{\mathsf{expm1}\left(\varepsilon \cdot a\right)}\\ \end{array} \]

Alternative 2: 93.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -1.5 \cdot 10^{+277} \lor \neg \left(a \leq 3.1 \cdot 10^{+109}\right):\\ \;\;\;\;\mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\varepsilon \cdot a\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{a} + \frac{1}{b}\\ \end{array} \end{array} \]
(FPCore (a b eps)
 :precision binary64
 (if (or (<= a -1.5e+277) (not (<= a 3.1e+109)))
   (* (expm1 (* eps (+ a b))) (/ (/ eps (expm1 (* eps b))) (expm1 (* eps a))))
   (+ (/ 1.0 a) (/ 1.0 b))))
double code(double a, double b, double eps) {
	double tmp;
	if ((a <= -1.5e+277) || !(a <= 3.1e+109)) {
		tmp = expm1((eps * (a + b))) * ((eps / expm1((eps * b))) / expm1((eps * a)));
	} else {
		tmp = (1.0 / a) + (1.0 / b);
	}
	return tmp;
}
public static double code(double a, double b, double eps) {
	double tmp;
	if ((a <= -1.5e+277) || !(a <= 3.1e+109)) {
		tmp = Math.expm1((eps * (a + b))) * ((eps / Math.expm1((eps * b))) / Math.expm1((eps * a)));
	} else {
		tmp = (1.0 / a) + (1.0 / b);
	}
	return tmp;
}
def code(a, b, eps):
	tmp = 0
	if (a <= -1.5e+277) or not (a <= 3.1e+109):
		tmp = math.expm1((eps * (a + b))) * ((eps / math.expm1((eps * b))) / math.expm1((eps * a)))
	else:
		tmp = (1.0 / a) + (1.0 / b)
	return tmp
function code(a, b, eps)
	tmp = 0.0
	if ((a <= -1.5e+277) || !(a <= 3.1e+109))
		tmp = Float64(expm1(Float64(eps * Float64(a + b))) * Float64(Float64(eps / expm1(Float64(eps * b))) / expm1(Float64(eps * a))));
	else
		tmp = Float64(Float64(1.0 / a) + Float64(1.0 / b));
	end
	return tmp
end
code[a_, b_, eps_] := If[Or[LessEqual[a, -1.5e+277], N[Not[LessEqual[a, 3.1e+109]], $MachinePrecision]], N[(N[(Exp[N[(eps * N[(a + b), $MachinePrecision]), $MachinePrecision]] - 1), $MachinePrecision] * N[(N[(eps / N[(Exp[N[(eps * b), $MachinePrecision]] - 1), $MachinePrecision]), $MachinePrecision] / N[(Exp[N[(eps * a), $MachinePrecision]] - 1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 / a), $MachinePrecision] + N[(1.0 / b), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \leq -1.5 \cdot 10^{+277} \lor \neg \left(a \leq 3.1 \cdot 10^{+109}\right):\\
\;\;\;\;\mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\varepsilon \cdot a\right)}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{a} + \frac{1}{b}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if a < -1.49999999999999991e277 or 3.09999999999999992e109 < a

    1. Initial program 30.5%

      \[\frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\left(e^{a \cdot \varepsilon} - 1\right) \cdot \left(e^{b \cdot \varepsilon} - 1\right)} \]
    2. Step-by-step derivation
      1. *-commutative30.5%

        \[\leadsto \frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\color{blue}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
      2. associate-*l/30.5%

        \[\leadsto \color{blue}{\frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)} \]
      3. *-commutative30.5%

        \[\leadsto \color{blue}{\left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right) \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
      4. expm1-def31.2%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\left(a + b\right) \cdot \varepsilon\right)} \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \]
      5. *-commutative31.2%

        \[\leadsto \mathsf{expm1}\left(\color{blue}{\varepsilon \cdot \left(a + b\right)}\right) \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \]
      6. associate-/r*31.2%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \color{blue}{\frac{\frac{\varepsilon}{e^{b \cdot \varepsilon} - 1}}{e^{a \cdot \varepsilon} - 1}} \]
      7. expm1-def54.5%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\color{blue}{\mathsf{expm1}\left(b \cdot \varepsilon\right)}}}{e^{a \cdot \varepsilon} - 1} \]
      8. *-commutative54.5%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot b}\right)}}{e^{a \cdot \varepsilon} - 1} \]
      9. expm1-def78.3%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\color{blue}{\mathsf{expm1}\left(a \cdot \varepsilon\right)}} \]
      10. *-commutative78.3%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot a}\right)} \]
    3. Simplified78.3%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\varepsilon \cdot a\right)}} \]

    if -1.49999999999999991e277 < a < 3.09999999999999992e109

    1. Initial program 3.0%

      \[\frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\left(e^{a \cdot \varepsilon} - 1\right) \cdot \left(e^{b \cdot \varepsilon} - 1\right)} \]
    2. Step-by-step derivation
      1. *-commutative3.0%

        \[\leadsto \frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\color{blue}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
      2. associate-*l/3.0%

        \[\leadsto \color{blue}{\frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)} \]
      3. *-commutative3.0%

        \[\leadsto \color{blue}{\left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right) \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
      4. expm1-def5.1%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\left(a + b\right) \cdot \varepsilon\right)} \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \]
      5. *-commutative5.1%

        \[\leadsto \mathsf{expm1}\left(\color{blue}{\varepsilon \cdot \left(a + b\right)}\right) \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \]
      6. associate-/r*5.1%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \color{blue}{\frac{\frac{\varepsilon}{e^{b \cdot \varepsilon} - 1}}{e^{a \cdot \varepsilon} - 1}} \]
      7. expm1-def8.5%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\color{blue}{\mathsf{expm1}\left(b \cdot \varepsilon\right)}}}{e^{a \cdot \varepsilon} - 1} \]
      8. *-commutative8.5%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot b}\right)}}{e^{a \cdot \varepsilon} - 1} \]
      9. expm1-def43.1%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\color{blue}{\mathsf{expm1}\left(a \cdot \varepsilon\right)}} \]
      10. *-commutative43.1%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot a}\right)} \]
    3. Simplified43.1%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\varepsilon \cdot a\right)}} \]
    4. Taylor expanded in eps around 0 75.9%

      \[\leadsto \color{blue}{\frac{a + b}{a \cdot b}} \]
    5. Taylor expanded in a around 0 97.6%

      \[\leadsto \color{blue}{\frac{1}{a} + \frac{1}{b}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification94.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -1.5 \cdot 10^{+277} \lor \neg \left(a \leq 3.1 \cdot 10^{+109}\right):\\ \;\;\;\;\mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\varepsilon \cdot a\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{a} + \frac{1}{b}\\ \end{array} \]

Alternative 3: 94.0% accurate, 2.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\varepsilon \leq 5.3 \cdot 10^{-51}:\\ \;\;\;\;\frac{1}{a} + \frac{1}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)} \cdot \frac{a + b}{a}\\ \end{array} \end{array} \]
(FPCore (a b eps)
 :precision binary64
 (if (<= eps 5.3e-51)
   (+ (/ 1.0 a) (/ 1.0 b))
   (* (/ eps (expm1 (* eps b))) (/ (+ a b) a))))
double code(double a, double b, double eps) {
	double tmp;
	if (eps <= 5.3e-51) {
		tmp = (1.0 / a) + (1.0 / b);
	} else {
		tmp = (eps / expm1((eps * b))) * ((a + b) / a);
	}
	return tmp;
}
public static double code(double a, double b, double eps) {
	double tmp;
	if (eps <= 5.3e-51) {
		tmp = (1.0 / a) + (1.0 / b);
	} else {
		tmp = (eps / Math.expm1((eps * b))) * ((a + b) / a);
	}
	return tmp;
}
def code(a, b, eps):
	tmp = 0
	if eps <= 5.3e-51:
		tmp = (1.0 / a) + (1.0 / b)
	else:
		tmp = (eps / math.expm1((eps * b))) * ((a + b) / a)
	return tmp
function code(a, b, eps)
	tmp = 0.0
	if (eps <= 5.3e-51)
		tmp = Float64(Float64(1.0 / a) + Float64(1.0 / b));
	else
		tmp = Float64(Float64(eps / expm1(Float64(eps * b))) * Float64(Float64(a + b) / a));
	end
	return tmp
end
code[a_, b_, eps_] := If[LessEqual[eps, 5.3e-51], N[(N[(1.0 / a), $MachinePrecision] + N[(1.0 / b), $MachinePrecision]), $MachinePrecision], N[(N[(eps / N[(Exp[N[(eps * b), $MachinePrecision]] - 1), $MachinePrecision]), $MachinePrecision] * N[(N[(a + b), $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\varepsilon \leq 5.3 \cdot 10^{-51}:\\
\;\;\;\;\frac{1}{a} + \frac{1}{b}\\

\mathbf{else}:\\
\;\;\;\;\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)} \cdot \frac{a + b}{a}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if eps < 5.29999999999999974e-51

    1. Initial program 6.1%

      \[\frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\left(e^{a \cdot \varepsilon} - 1\right) \cdot \left(e^{b \cdot \varepsilon} - 1\right)} \]
    2. Step-by-step derivation
      1. *-commutative6.1%

        \[\leadsto \frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\color{blue}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
      2. associate-*l/6.1%

        \[\leadsto \color{blue}{\frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)} \]
      3. *-commutative6.1%

        \[\leadsto \color{blue}{\left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right) \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
      4. expm1-def8.0%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\left(a + b\right) \cdot \varepsilon\right)} \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \]
      5. *-commutative8.0%

        \[\leadsto \mathsf{expm1}\left(\color{blue}{\varepsilon \cdot \left(a + b\right)}\right) \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \]
      6. associate-/r*8.0%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \color{blue}{\frac{\frac{\varepsilon}{e^{b \cdot \varepsilon} - 1}}{e^{a \cdot \varepsilon} - 1}} \]
      7. expm1-def14.6%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\color{blue}{\mathsf{expm1}\left(b \cdot \varepsilon\right)}}}{e^{a \cdot \varepsilon} - 1} \]
      8. *-commutative14.6%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot b}\right)}}{e^{a \cdot \varepsilon} - 1} \]
      9. expm1-def46.2%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\color{blue}{\mathsf{expm1}\left(a \cdot \varepsilon\right)}} \]
      10. *-commutative46.2%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot a}\right)} \]
    3. Simplified46.2%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\varepsilon \cdot a\right)}} \]
    4. Taylor expanded in eps around 0 74.8%

      \[\leadsto \color{blue}{\frac{a + b}{a \cdot b}} \]
    5. Taylor expanded in a around 0 95.1%

      \[\leadsto \color{blue}{\frac{1}{a} + \frac{1}{b}} \]

    if 5.29999999999999974e-51 < eps

    1. Initial program 23.7%

      \[\frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\left(e^{a \cdot \varepsilon} - 1\right) \cdot \left(e^{b \cdot \varepsilon} - 1\right)} \]
    2. Step-by-step derivation
      1. *-commutative23.7%

        \[\leadsto \frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\color{blue}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
      2. times-frac23.7%

        \[\leadsto \color{blue}{\frac{\varepsilon}{e^{b \cdot \varepsilon} - 1} \cdot \frac{e^{\left(a + b\right) \cdot \varepsilon} - 1}{e^{a \cdot \varepsilon} - 1}} \]
      3. +-commutative23.7%

        \[\leadsto \frac{\varepsilon}{e^{b \cdot \varepsilon} - 1} \cdot \frac{e^{\color{blue}{\left(b + a\right)} \cdot \varepsilon} - 1}{e^{a \cdot \varepsilon} - 1} \]
      4. expm1-def32.4%

        \[\leadsto \frac{\varepsilon}{\color{blue}{\mathsf{expm1}\left(b \cdot \varepsilon\right)}} \cdot \frac{e^{\left(b + a\right) \cdot \varepsilon} - 1}{e^{a \cdot \varepsilon} - 1} \]
      5. *-commutative32.4%

        \[\leadsto \frac{\varepsilon}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot b}\right)} \cdot \frac{e^{\left(b + a\right) \cdot \varepsilon} - 1}{e^{a \cdot \varepsilon} - 1} \]
      6. expm1-def34.2%

        \[\leadsto \frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)} \cdot \frac{\color{blue}{\mathsf{expm1}\left(\left(b + a\right) \cdot \varepsilon\right)}}{e^{a \cdot \varepsilon} - 1} \]
      7. +-commutative34.2%

        \[\leadsto \frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)} \cdot \frac{\mathsf{expm1}\left(\color{blue}{\left(a + b\right)} \cdot \varepsilon\right)}{e^{a \cdot \varepsilon} - 1} \]
      8. *-commutative34.2%

        \[\leadsto \frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)} \cdot \frac{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot \left(a + b\right)}\right)}{e^{a \cdot \varepsilon} - 1} \]
      9. expm1-def95.7%

        \[\leadsto \frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)} \cdot \frac{\mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right)}{\color{blue}{\mathsf{expm1}\left(a \cdot \varepsilon\right)}} \]
      10. *-commutative95.7%

        \[\leadsto \frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)} \cdot \frac{\mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right)}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot a}\right)} \]
    3. Simplified95.7%

      \[\leadsto \color{blue}{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)} \cdot \frac{\mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right)}{\mathsf{expm1}\left(\varepsilon \cdot a\right)}} \]
    4. Taylor expanded in eps around 0 69.1%

      \[\leadsto \frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)} \cdot \color{blue}{\frac{a + b}{a}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification92.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \leq 5.3 \cdot 10^{-51}:\\ \;\;\;\;\frac{1}{a} + \frac{1}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)} \cdot \frac{a + b}{a}\\ \end{array} \]

Alternative 4: 57.8% accurate, 34.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 1.3 \cdot 10^{-149} \lor \neg \left(b \leq 1.6 \cdot 10^{-55}\right) \land b \leq 1.6 \cdot 10^{-28}:\\ \;\;\;\;\frac{1}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{a}\\ \end{array} \end{array} \]
(FPCore (a b eps)
 :precision binary64
 (if (or (<= b 1.3e-149) (and (not (<= b 1.6e-55)) (<= b 1.6e-28)))
   (/ 1.0 b)
   (/ 1.0 a)))
double code(double a, double b, double eps) {
	double tmp;
	if ((b <= 1.3e-149) || (!(b <= 1.6e-55) && (b <= 1.6e-28))) {
		tmp = 1.0 / b;
	} else {
		tmp = 1.0 / a;
	}
	return tmp;
}
real(8) function code(a, b, eps)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: eps
    real(8) :: tmp
    if ((b <= 1.3d-149) .or. (.not. (b <= 1.6d-55)) .and. (b <= 1.6d-28)) then
        tmp = 1.0d0 / b
    else
        tmp = 1.0d0 / a
    end if
    code = tmp
end function
public static double code(double a, double b, double eps) {
	double tmp;
	if ((b <= 1.3e-149) || (!(b <= 1.6e-55) && (b <= 1.6e-28))) {
		tmp = 1.0 / b;
	} else {
		tmp = 1.0 / a;
	}
	return tmp;
}
def code(a, b, eps):
	tmp = 0
	if (b <= 1.3e-149) or (not (b <= 1.6e-55) and (b <= 1.6e-28)):
		tmp = 1.0 / b
	else:
		tmp = 1.0 / a
	return tmp
function code(a, b, eps)
	tmp = 0.0
	if ((b <= 1.3e-149) || (!(b <= 1.6e-55) && (b <= 1.6e-28)))
		tmp = Float64(1.0 / b);
	else
		tmp = Float64(1.0 / a);
	end
	return tmp
end
function tmp_2 = code(a, b, eps)
	tmp = 0.0;
	if ((b <= 1.3e-149) || (~((b <= 1.6e-55)) && (b <= 1.6e-28)))
		tmp = 1.0 / b;
	else
		tmp = 1.0 / a;
	end
	tmp_2 = tmp;
end
code[a_, b_, eps_] := If[Or[LessEqual[b, 1.3e-149], And[N[Not[LessEqual[b, 1.6e-55]], $MachinePrecision], LessEqual[b, 1.6e-28]]], N[(1.0 / b), $MachinePrecision], N[(1.0 / a), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq 1.3 \cdot 10^{-149} \lor \neg \left(b \leq 1.6 \cdot 10^{-55}\right) \land b \leq 1.6 \cdot 10^{-28}:\\
\;\;\;\;\frac{1}{b}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{a}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < 1.29999999999999999e-149 or 1.6000000000000001e-55 < b < 1.59999999999999991e-28

    1. Initial program 6.9%

      \[\frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\left(e^{a \cdot \varepsilon} - 1\right) \cdot \left(e^{b \cdot \varepsilon} - 1\right)} \]
    2. Step-by-step derivation
      1. *-commutative6.9%

        \[\leadsto \frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\color{blue}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
      2. associate-*l/6.9%

        \[\leadsto \color{blue}{\frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)} \]
      3. *-commutative6.9%

        \[\leadsto \color{blue}{\left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right) \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
      4. expm1-def8.8%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\left(a + b\right) \cdot \varepsilon\right)} \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \]
      5. *-commutative8.8%

        \[\leadsto \mathsf{expm1}\left(\color{blue}{\varepsilon \cdot \left(a + b\right)}\right) \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \]
      6. associate-/r*8.8%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \color{blue}{\frac{\frac{\varepsilon}{e^{b \cdot \varepsilon} - 1}}{e^{a \cdot \varepsilon} - 1}} \]
      7. expm1-def16.4%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\color{blue}{\mathsf{expm1}\left(b \cdot \varepsilon\right)}}}{e^{a \cdot \varepsilon} - 1} \]
      8. *-commutative16.4%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot b}\right)}}{e^{a \cdot \varepsilon} - 1} \]
      9. expm1-def43.0%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\color{blue}{\mathsf{expm1}\left(a \cdot \varepsilon\right)}} \]
      10. *-commutative43.0%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot a}\right)} \]
    3. Simplified43.0%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\varepsilon \cdot a\right)}} \]
    4. Taylor expanded in b around 0 54.3%

      \[\leadsto \color{blue}{\frac{1}{b}} \]

    if 1.29999999999999999e-149 < b < 1.6000000000000001e-55 or 1.59999999999999991e-28 < b

    1. Initial program 9.2%

      \[\frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\left(e^{a \cdot \varepsilon} - 1\right) \cdot \left(e^{b \cdot \varepsilon} - 1\right)} \]
    2. Step-by-step derivation
      1. *-commutative9.2%

        \[\leadsto \frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\color{blue}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
      2. associate-*l/9.2%

        \[\leadsto \color{blue}{\frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)} \]
      3. *-commutative9.2%

        \[\leadsto \color{blue}{\left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right) \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
      4. expm1-def10.9%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\left(a + b\right) \cdot \varepsilon\right)} \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \]
      5. *-commutative10.9%

        \[\leadsto \mathsf{expm1}\left(\color{blue}{\varepsilon \cdot \left(a + b\right)}\right) \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \]
      6. associate-/r*10.9%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \color{blue}{\frac{\frac{\varepsilon}{e^{b \cdot \varepsilon} - 1}}{e^{a \cdot \varepsilon} - 1}} \]
      7. expm1-def16.0%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\color{blue}{\mathsf{expm1}\left(b \cdot \varepsilon\right)}}}{e^{a \cdot \varepsilon} - 1} \]
      8. *-commutative16.0%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot b}\right)}}{e^{a \cdot \varepsilon} - 1} \]
      9. expm1-def61.5%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\color{blue}{\mathsf{expm1}\left(a \cdot \varepsilon\right)}} \]
      10. *-commutative61.5%

        \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot a}\right)} \]
    3. Simplified61.5%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\varepsilon \cdot a\right)}} \]
    4. Taylor expanded in a around 0 73.5%

      \[\leadsto \color{blue}{\frac{1}{a}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification60.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 1.3 \cdot 10^{-149} \lor \neg \left(b \leq 1.6 \cdot 10^{-55}\right) \land b \leq 1.6 \cdot 10^{-28}:\\ \;\;\;\;\frac{1}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{a}\\ \end{array} \]

Alternative 5: 94.8% accurate, 45.9× speedup?

\[\begin{array}{l} \\ \frac{1}{a} + \frac{1}{b} \end{array} \]
(FPCore (a b eps) :precision binary64 (+ (/ 1.0 a) (/ 1.0 b)))
double code(double a, double b, double eps) {
	return (1.0 / a) + (1.0 / b);
}
real(8) function code(a, b, eps)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: eps
    code = (1.0d0 / a) + (1.0d0 / b)
end function
public static double code(double a, double b, double eps) {
	return (1.0 / a) + (1.0 / b);
}
def code(a, b, eps):
	return (1.0 / a) + (1.0 / b)
function code(a, b, eps)
	return Float64(Float64(1.0 / a) + Float64(1.0 / b))
end
function tmp = code(a, b, eps)
	tmp = (1.0 / a) + (1.0 / b);
end
code[a_, b_, eps_] := N[(N[(1.0 / a), $MachinePrecision] + N[(1.0 / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{a} + \frac{1}{b}
\end{array}
Derivation
  1. Initial program 7.7%

    \[\frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\left(e^{a \cdot \varepsilon} - 1\right) \cdot \left(e^{b \cdot \varepsilon} - 1\right)} \]
  2. Step-by-step derivation
    1. *-commutative7.7%

      \[\leadsto \frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\color{blue}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
    2. associate-*l/7.7%

      \[\leadsto \color{blue}{\frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)} \]
    3. *-commutative7.7%

      \[\leadsto \color{blue}{\left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right) \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
    4. expm1-def9.5%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\left(a + b\right) \cdot \varepsilon\right)} \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \]
    5. *-commutative9.5%

      \[\leadsto \mathsf{expm1}\left(\color{blue}{\varepsilon \cdot \left(a + b\right)}\right) \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \]
    6. associate-/r*9.5%

      \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \color{blue}{\frac{\frac{\varepsilon}{e^{b \cdot \varepsilon} - 1}}{e^{a \cdot \varepsilon} - 1}} \]
    7. expm1-def16.3%

      \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\color{blue}{\mathsf{expm1}\left(b \cdot \varepsilon\right)}}}{e^{a \cdot \varepsilon} - 1} \]
    8. *-commutative16.3%

      \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot b}\right)}}{e^{a \cdot \varepsilon} - 1} \]
    9. expm1-def49.0%

      \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\color{blue}{\mathsf{expm1}\left(a \cdot \varepsilon\right)}} \]
    10. *-commutative49.0%

      \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot a}\right)} \]
  3. Simplified49.0%

    \[\leadsto \color{blue}{\mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\varepsilon \cdot a\right)}} \]
  4. Taylor expanded in eps around 0 73.7%

    \[\leadsto \color{blue}{\frac{a + b}{a \cdot b}} \]
  5. Taylor expanded in a around 0 93.6%

    \[\leadsto \color{blue}{\frac{1}{a} + \frac{1}{b}} \]
  6. Final simplification93.6%

    \[\leadsto \frac{1}{a} + \frac{1}{b} \]

Alternative 6: 47.8% accurate, 107.0× speedup?

\[\begin{array}{l} \\ \frac{1}{a} \end{array} \]
(FPCore (a b eps) :precision binary64 (/ 1.0 a))
double code(double a, double b, double eps) {
	return 1.0 / a;
}
real(8) function code(a, b, eps)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: eps
    code = 1.0d0 / a
end function
public static double code(double a, double b, double eps) {
	return 1.0 / a;
}
def code(a, b, eps):
	return 1.0 / a
function code(a, b, eps)
	return Float64(1.0 / a)
end
function tmp = code(a, b, eps)
	tmp = 1.0 / a;
end
code[a_, b_, eps_] := N[(1.0 / a), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{a}
\end{array}
Derivation
  1. Initial program 7.7%

    \[\frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\left(e^{a \cdot \varepsilon} - 1\right) \cdot \left(e^{b \cdot \varepsilon} - 1\right)} \]
  2. Step-by-step derivation
    1. *-commutative7.7%

      \[\leadsto \frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\color{blue}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
    2. associate-*l/7.7%

      \[\leadsto \color{blue}{\frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)} \]
    3. *-commutative7.7%

      \[\leadsto \color{blue}{\left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right) \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
    4. expm1-def9.5%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\left(a + b\right) \cdot \varepsilon\right)} \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \]
    5. *-commutative9.5%

      \[\leadsto \mathsf{expm1}\left(\color{blue}{\varepsilon \cdot \left(a + b\right)}\right) \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \]
    6. associate-/r*9.5%

      \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \color{blue}{\frac{\frac{\varepsilon}{e^{b \cdot \varepsilon} - 1}}{e^{a \cdot \varepsilon} - 1}} \]
    7. expm1-def16.3%

      \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\color{blue}{\mathsf{expm1}\left(b \cdot \varepsilon\right)}}}{e^{a \cdot \varepsilon} - 1} \]
    8. *-commutative16.3%

      \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot b}\right)}}{e^{a \cdot \varepsilon} - 1} \]
    9. expm1-def49.0%

      \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\color{blue}{\mathsf{expm1}\left(a \cdot \varepsilon\right)}} \]
    10. *-commutative49.0%

      \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot a}\right)} \]
  3. Simplified49.0%

    \[\leadsto \color{blue}{\mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\varepsilon \cdot a\right)}} \]
  4. Taylor expanded in a around 0 51.6%

    \[\leadsto \color{blue}{\frac{1}{a}} \]
  5. Final simplification51.6%

    \[\leadsto \frac{1}{a} \]

Alternative 7: 3.3% accurate, 321.0× speedup?

\[\begin{array}{l} \\ 1 \end{array} \]
(FPCore (a b eps) :precision binary64 1.0)
double code(double a, double b, double eps) {
	return 1.0;
}
real(8) function code(a, b, eps)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: eps
    code = 1.0d0
end function
public static double code(double a, double b, double eps) {
	return 1.0;
}
def code(a, b, eps):
	return 1.0
function code(a, b, eps)
	return 1.0
end
function tmp = code(a, b, eps)
	tmp = 1.0;
end
code[a_, b_, eps_] := 1.0
\begin{array}{l}

\\
1
\end{array}
Derivation
  1. Initial program 7.7%

    \[\frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\left(e^{a \cdot \varepsilon} - 1\right) \cdot \left(e^{b \cdot \varepsilon} - 1\right)} \]
  2. Step-by-step derivation
    1. *-commutative7.7%

      \[\leadsto \frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\color{blue}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
    2. associate-*l/7.7%

      \[\leadsto \color{blue}{\frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)} \]
    3. *-commutative7.7%

      \[\leadsto \color{blue}{\left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right) \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
    4. expm1-def9.5%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\left(a + b\right) \cdot \varepsilon\right)} \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \]
    5. *-commutative9.5%

      \[\leadsto \mathsf{expm1}\left(\color{blue}{\varepsilon \cdot \left(a + b\right)}\right) \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \]
    6. associate-/r*9.5%

      \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \color{blue}{\frac{\frac{\varepsilon}{e^{b \cdot \varepsilon} - 1}}{e^{a \cdot \varepsilon} - 1}} \]
    7. expm1-def16.3%

      \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\color{blue}{\mathsf{expm1}\left(b \cdot \varepsilon\right)}}}{e^{a \cdot \varepsilon} - 1} \]
    8. *-commutative16.3%

      \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot b}\right)}}{e^{a \cdot \varepsilon} - 1} \]
    9. expm1-def49.0%

      \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\color{blue}{\mathsf{expm1}\left(a \cdot \varepsilon\right)}} \]
    10. *-commutative49.0%

      \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot a}\right)} \]
  3. Simplified49.0%

    \[\leadsto \color{blue}{\mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\varepsilon \cdot a\right)}} \]
  4. Taylor expanded in eps around 0 73.7%

    \[\leadsto \color{blue}{\frac{a + b}{a \cdot b}} \]
  5. Step-by-step derivation
    1. add-exp-log35.2%

      \[\leadsto \color{blue}{e^{\log \left(\frac{a + b}{a \cdot b}\right)}} \]
  6. Applied egg-rr35.2%

    \[\leadsto \color{blue}{e^{\log \left(\frac{a + b}{a \cdot b}\right)}} \]
  7. Taylor expanded in a around 0 25.3%

    \[\leadsto e^{\color{blue}{-1 \cdot \log a}} \]
  8. Step-by-step derivation
    1. neg-mul-125.3%

      \[\leadsto e^{\color{blue}{-\log a}} \]
  9. Simplified25.3%

    \[\leadsto e^{\color{blue}{-\log a}} \]
  10. Step-by-step derivation
    1. exp-neg25.3%

      \[\leadsto \color{blue}{\frac{1}{e^{\log a}}} \]
    2. add-exp-log51.6%

      \[\leadsto \frac{1}{\color{blue}{a}} \]
    3. add-sqr-sqrt27.4%

      \[\leadsto \frac{1}{\color{blue}{\sqrt{a} \cdot \sqrt{a}}} \]
    4. associate-/r*27.4%

      \[\leadsto \color{blue}{\frac{\frac{1}{\sqrt{a}}}{\sqrt{a}}} \]
    5. metadata-eval27.4%

      \[\leadsto \frac{\frac{\color{blue}{\sqrt{1}}}{\sqrt{a}}}{\sqrt{a}} \]
    6. sqrt-div27.4%

      \[\leadsto \frac{\color{blue}{\sqrt{\frac{1}{a}}}}{\sqrt{a}} \]
    7. add-exp-log25.7%

      \[\leadsto \frac{\sqrt{\frac{1}{\color{blue}{e^{\log a}}}}}{\sqrt{a}} \]
    8. exp-neg25.7%

      \[\leadsto \frac{\sqrt{\color{blue}{e^{-\log a}}}}{\sqrt{a}} \]
    9. add-sqr-sqrt19.6%

      \[\leadsto \frac{\sqrt{e^{\color{blue}{\sqrt{-\log a} \cdot \sqrt{-\log a}}}}}{\sqrt{a}} \]
    10. sqrt-unprod21.0%

      \[\leadsto \frac{\sqrt{e^{\color{blue}{\sqrt{\left(-\log a\right) \cdot \left(-\log a\right)}}}}}{\sqrt{a}} \]
    11. sqr-neg21.0%

      \[\leadsto \frac{\sqrt{e^{\sqrt{\color{blue}{\log a \cdot \log a}}}}}{\sqrt{a}} \]
    12. sqrt-unprod1.1%

      \[\leadsto \frac{\sqrt{e^{\color{blue}{\sqrt{\log a} \cdot \sqrt{\log a}}}}}{\sqrt{a}} \]
    13. add-sqr-sqrt2.3%

      \[\leadsto \frac{\sqrt{e^{\color{blue}{\log a}}}}{\sqrt{a}} \]
    14. add-exp-log2.3%

      \[\leadsto \frac{\sqrt{\color{blue}{a}}}{\sqrt{a}} \]
  11. Applied egg-rr2.3%

    \[\leadsto \color{blue}{\frac{\sqrt{a}}{\sqrt{a}}} \]
  12. Step-by-step derivation
    1. *-inverses3.2%

      \[\leadsto \color{blue}{1} \]
  13. Simplified3.2%

    \[\leadsto \color{blue}{1} \]
  14. Final simplification3.2%

    \[\leadsto 1 \]

Alternative 8: 3.3% accurate, 321.0× speedup?

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

\\
a
\end{array}
Derivation
  1. Initial program 7.7%

    \[\frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\left(e^{a \cdot \varepsilon} - 1\right) \cdot \left(e^{b \cdot \varepsilon} - 1\right)} \]
  2. Step-by-step derivation
    1. *-commutative7.7%

      \[\leadsto \frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\color{blue}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
    2. associate-*l/7.7%

      \[\leadsto \color{blue}{\frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)} \]
    3. *-commutative7.7%

      \[\leadsto \color{blue}{\left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right) \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)}} \]
    4. expm1-def9.5%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\left(a + b\right) \cdot \varepsilon\right)} \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \]
    5. *-commutative9.5%

      \[\leadsto \mathsf{expm1}\left(\color{blue}{\varepsilon \cdot \left(a + b\right)}\right) \cdot \frac{\varepsilon}{\left(e^{b \cdot \varepsilon} - 1\right) \cdot \left(e^{a \cdot \varepsilon} - 1\right)} \]
    6. associate-/r*9.5%

      \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \color{blue}{\frac{\frac{\varepsilon}{e^{b \cdot \varepsilon} - 1}}{e^{a \cdot \varepsilon} - 1}} \]
    7. expm1-def16.3%

      \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\color{blue}{\mathsf{expm1}\left(b \cdot \varepsilon\right)}}}{e^{a \cdot \varepsilon} - 1} \]
    8. *-commutative16.3%

      \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot b}\right)}}{e^{a \cdot \varepsilon} - 1} \]
    9. expm1-def49.0%

      \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\color{blue}{\mathsf{expm1}\left(a \cdot \varepsilon\right)}} \]
    10. *-commutative49.0%

      \[\leadsto \mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\color{blue}{\varepsilon \cdot a}\right)} \]
  3. Simplified49.0%

    \[\leadsto \color{blue}{\mathsf{expm1}\left(\varepsilon \cdot \left(a + b\right)\right) \cdot \frac{\frac{\varepsilon}{\mathsf{expm1}\left(\varepsilon \cdot b\right)}}{\mathsf{expm1}\left(\varepsilon \cdot a\right)}} \]
  4. Taylor expanded in eps around 0 73.7%

    \[\leadsto \color{blue}{\frac{a + b}{a \cdot b}} \]
  5. Step-by-step derivation
    1. add-exp-log35.2%

      \[\leadsto \color{blue}{e^{\log \left(\frac{a + b}{a \cdot b}\right)}} \]
  6. Applied egg-rr35.2%

    \[\leadsto \color{blue}{e^{\log \left(\frac{a + b}{a \cdot b}\right)}} \]
  7. Taylor expanded in a around 0 25.3%

    \[\leadsto e^{\color{blue}{-1 \cdot \log a}} \]
  8. Step-by-step derivation
    1. neg-mul-125.3%

      \[\leadsto e^{\color{blue}{-\log a}} \]
  9. Simplified25.3%

    \[\leadsto e^{\color{blue}{-\log a}} \]
  10. Step-by-step derivation
    1. add-sqr-sqrt19.3%

      \[\leadsto e^{\color{blue}{\sqrt{-\log a} \cdot \sqrt{-\log a}}} \]
    2. sqrt-unprod20.5%

      \[\leadsto e^{\color{blue}{\sqrt{\left(-\log a\right) \cdot \left(-\log a\right)}}} \]
    3. sqr-neg20.5%

      \[\leadsto e^{\sqrt{\color{blue}{\log a \cdot \log a}}} \]
    4. sqrt-unprod0.9%

      \[\leadsto e^{\color{blue}{\sqrt{\log a} \cdot \sqrt{\log a}}} \]
    5. add-sqr-sqrt1.8%

      \[\leadsto e^{\color{blue}{\log a}} \]
    6. add-exp-log3.4%

      \[\leadsto \color{blue}{a} \]
    7. expm1-log1p-u2.7%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(a\right)\right)} \]
    8. expm1-udef2.2%

      \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(a\right)} - 1} \]
  11. Applied egg-rr2.2%

    \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(a\right)} - 1} \]
  12. Step-by-step derivation
    1. expm1-def2.7%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(a\right)\right)} \]
    2. expm1-log1p3.4%

      \[\leadsto \color{blue}{a} \]
  13. Simplified3.4%

    \[\leadsto \color{blue}{a} \]
  14. Final simplification3.4%

    \[\leadsto a \]

Developer target: 78.4% accurate, 45.9× speedup?

\[\begin{array}{l} \\ \frac{a + b}{a \cdot b} \end{array} \]
(FPCore (a b eps) :precision binary64 (/ (+ a b) (* a b)))
double code(double a, double b, double eps) {
	return (a + b) / (a * b);
}
real(8) function code(a, b, eps)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: eps
    code = (a + b) / (a * b)
end function
public static double code(double a, double b, double eps) {
	return (a + b) / (a * b);
}
def code(a, b, eps):
	return (a + b) / (a * b)
function code(a, b, eps)
	return Float64(Float64(a + b) / Float64(a * b))
end
function tmp = code(a, b, eps)
	tmp = (a + b) / (a * b);
end
code[a_, b_, eps_] := N[(N[(a + b), $MachinePrecision] / N[(a * b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{a + b}{a \cdot b}
\end{array}

Reproduce

?
herbie shell --seed 2023280 
(FPCore (a b eps)
  :name "expq3 (problem 3.4.2)"
  :precision binary64
  :pre (and (< -1.0 eps) (< eps 1.0))

  :herbie-target
  (/ (+ a b) (* a b))

  (/ (* eps (- (exp (* (+ a b) eps)) 1.0)) (* (- (exp (* a eps)) 1.0) (- (exp (* b eps)) 1.0))))