expq2 (section 3.11)

Percentage Accurate: 37.5% → 100.0%
Time: 7.6s
Alternatives: 10
Speedup: 68.3×

Specification

?
\[710 > x\]
\[\begin{array}{l} \\ \frac{e^{x}}{e^{x} - 1} \end{array} \]
(FPCore (x) :precision binary64 (/ (exp x) (- (exp x) 1.0)))
double code(double x) {
	return exp(x) / (exp(x) - 1.0);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = exp(x) / (exp(x) - 1.0d0)
end function
public static double code(double x) {
	return Math.exp(x) / (Math.exp(x) - 1.0);
}
def code(x):
	return math.exp(x) / (math.exp(x) - 1.0)
function code(x)
	return Float64(exp(x) / Float64(exp(x) - 1.0))
end
function tmp = code(x)
	tmp = exp(x) / (exp(x) - 1.0);
end
code[x_] := N[(N[Exp[x], $MachinePrecision] / N[(N[Exp[x], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{e^{x}}{e^{x} - 1}
\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 10 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: 37.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{e^{x}}{e^{x} - 1} \end{array} \]
(FPCore (x) :precision binary64 (/ (exp x) (- (exp x) 1.0)))
double code(double x) {
	return exp(x) / (exp(x) - 1.0);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = exp(x) / (exp(x) - 1.0d0)
end function
public static double code(double x) {
	return Math.exp(x) / (Math.exp(x) - 1.0);
}
def code(x):
	return math.exp(x) / (math.exp(x) - 1.0)
function code(x)
	return Float64(exp(x) / Float64(exp(x) - 1.0))
end
function tmp = code(x)
	tmp = exp(x) / (exp(x) - 1.0);
end
code[x_] := N[(N[Exp[x], $MachinePrecision] / N[(N[Exp[x], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{e^{x}}{e^{x} - 1}
\end{array}

Alternative 1: 100.0% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \frac{-1}{\mathsf{expm1}\left(-x\right)} \end{array} \]
(FPCore (x) :precision binary64 (/ -1.0 (expm1 (- x))))
double code(double x) {
	return -1.0 / expm1(-x);
}
public static double code(double x) {
	return -1.0 / Math.expm1(-x);
}
def code(x):
	return -1.0 / math.expm1(-x)
function code(x)
	return Float64(-1.0 / expm1(Float64(-x)))
end
code[x_] := N[(-1.0 / N[(Exp[(-x)] - 1), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-1}{\mathsf{expm1}\left(-x\right)}
\end{array}
Derivation
  1. Initial program 35.7%

    \[\frac{e^{x}}{e^{x} - 1} \]
  2. Step-by-step derivation
    1. sub-neg35.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} + \left(-1\right)}} \]
    2. +-commutative35.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{\left(-1\right) + e^{x}}} \]
    3. rgt-mult-inverse4.5%

      \[\leadsto \frac{e^{x}}{\left(-\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}\right) + e^{x}} \]
    4. exp-neg4.5%

      \[\leadsto \frac{e^{x}}{\left(-e^{x} \cdot \color{blue}{e^{-x}}\right) + e^{x}} \]
    5. distribute-rgt-neg-out4.5%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(-e^{-x}\right)} + e^{x}} \]
    6. *-rgt-identity4.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(-e^{-x}\right) + \color{blue}{e^{x} \cdot 1}} \]
    7. distribute-lft-in4.5%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(\left(-e^{-x}\right) + 1\right)}} \]
    8. neg-sub04.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(\color{blue}{\left(0 - e^{-x}\right)} + 1\right)} \]
    9. associate-+l-4.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(0 - \left(e^{-x} - 1\right)\right)}} \]
    10. neg-sub04.1%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(-\left(e^{-x} - 1\right)\right)}} \]
    11. associate-/r*4.1%

      \[\leadsto \color{blue}{\frac{\frac{e^{x}}{e^{x}}}{-\left(e^{-x} - 1\right)}} \]
    12. *-rgt-identity4.1%

      \[\leadsto \frac{\frac{\color{blue}{e^{x} \cdot 1}}{e^{x}}}{-\left(e^{-x} - 1\right)} \]
    13. associate-*r/4.1%

      \[\leadsto \frac{\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}}{-\left(e^{-x} - 1\right)} \]
    14. rgt-mult-inverse35.3%

      \[\leadsto \frac{\color{blue}{1}}{-\left(e^{-x} - 1\right)} \]
    15. distribute-frac-neg235.3%

      \[\leadsto \color{blue}{-\frac{1}{e^{-x} - 1}} \]
    16. distribute-neg-frac35.3%

      \[\leadsto \color{blue}{\frac{-1}{e^{-x} - 1}} \]
    17. metadata-eval35.3%

      \[\leadsto \frac{\color{blue}{-1}}{e^{-x} - 1} \]
    18. expm1-define100.0%

      \[\leadsto \frac{-1}{\color{blue}{\mathsf{expm1}\left(-x\right)}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{-1}{\mathsf{expm1}\left(-x\right)}} \]
  4. Add Preprocessing
  5. Add Preprocessing

Alternative 2: 98.0% accurate, 2.0× speedup?

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

\\
\frac{e^{x}}{x}
\end{array}
Derivation
  1. Initial program 35.7%

    \[\frac{e^{x}}{e^{x} - 1} \]
  2. Step-by-step derivation
    1. expm1-define100.0%

      \[\leadsto \frac{e^{x}}{\color{blue}{\mathsf{expm1}\left(x\right)}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{e^{x}}{\mathsf{expm1}\left(x\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 98.3%

    \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
  6. Add Preprocessing

Alternative 3: 91.2% accurate, 12.1× speedup?

\[\begin{array}{l} \\ \frac{-1}{x \cdot \left(x \cdot \left(0.5 + x \cdot \left(x \cdot 0.041666666666666664 - 0.16666666666666666\right)\right) + -1\right)} \end{array} \]
(FPCore (x)
 :precision binary64
 (/
  -1.0
  (*
   x
   (+
    (* x (+ 0.5 (* x (- (* x 0.041666666666666664) 0.16666666666666666))))
    -1.0))))
double code(double x) {
	return -1.0 / (x * ((x * (0.5 + (x * ((x * 0.041666666666666664) - 0.16666666666666666)))) + -1.0));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (-1.0d0) / (x * ((x * (0.5d0 + (x * ((x * 0.041666666666666664d0) - 0.16666666666666666d0)))) + (-1.0d0)))
end function
public static double code(double x) {
	return -1.0 / (x * ((x * (0.5 + (x * ((x * 0.041666666666666664) - 0.16666666666666666)))) + -1.0));
}
def code(x):
	return -1.0 / (x * ((x * (0.5 + (x * ((x * 0.041666666666666664) - 0.16666666666666666)))) + -1.0))
function code(x)
	return Float64(-1.0 / Float64(x * Float64(Float64(x * Float64(0.5 + Float64(x * Float64(Float64(x * 0.041666666666666664) - 0.16666666666666666)))) + -1.0)))
end
function tmp = code(x)
	tmp = -1.0 / (x * ((x * (0.5 + (x * ((x * 0.041666666666666664) - 0.16666666666666666)))) + -1.0));
end
code[x_] := N[(-1.0 / N[(x * N[(N[(x * N[(0.5 + N[(x * N[(N[(x * 0.041666666666666664), $MachinePrecision] - 0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-1}{x \cdot \left(x \cdot \left(0.5 + x \cdot \left(x \cdot 0.041666666666666664 - 0.16666666666666666\right)\right) + -1\right)}
\end{array}
Derivation
  1. Initial program 35.7%

    \[\frac{e^{x}}{e^{x} - 1} \]
  2. Step-by-step derivation
    1. sub-neg35.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} + \left(-1\right)}} \]
    2. +-commutative35.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{\left(-1\right) + e^{x}}} \]
    3. rgt-mult-inverse4.5%

      \[\leadsto \frac{e^{x}}{\left(-\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}\right) + e^{x}} \]
    4. exp-neg4.5%

      \[\leadsto \frac{e^{x}}{\left(-e^{x} \cdot \color{blue}{e^{-x}}\right) + e^{x}} \]
    5. distribute-rgt-neg-out4.5%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(-e^{-x}\right)} + e^{x}} \]
    6. *-rgt-identity4.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(-e^{-x}\right) + \color{blue}{e^{x} \cdot 1}} \]
    7. distribute-lft-in4.5%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(\left(-e^{-x}\right) + 1\right)}} \]
    8. neg-sub04.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(\color{blue}{\left(0 - e^{-x}\right)} + 1\right)} \]
    9. associate-+l-4.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(0 - \left(e^{-x} - 1\right)\right)}} \]
    10. neg-sub04.1%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(-\left(e^{-x} - 1\right)\right)}} \]
    11. associate-/r*4.1%

      \[\leadsto \color{blue}{\frac{\frac{e^{x}}{e^{x}}}{-\left(e^{-x} - 1\right)}} \]
    12. *-rgt-identity4.1%

      \[\leadsto \frac{\frac{\color{blue}{e^{x} \cdot 1}}{e^{x}}}{-\left(e^{-x} - 1\right)} \]
    13. associate-*r/4.1%

      \[\leadsto \frac{\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}}{-\left(e^{-x} - 1\right)} \]
    14. rgt-mult-inverse35.3%

      \[\leadsto \frac{\color{blue}{1}}{-\left(e^{-x} - 1\right)} \]
    15. distribute-frac-neg235.3%

      \[\leadsto \color{blue}{-\frac{1}{e^{-x} - 1}} \]
    16. distribute-neg-frac35.3%

      \[\leadsto \color{blue}{\frac{-1}{e^{-x} - 1}} \]
    17. metadata-eval35.3%

      \[\leadsto \frac{\color{blue}{-1}}{e^{-x} - 1} \]
    18. expm1-define100.0%

      \[\leadsto \frac{-1}{\color{blue}{\mathsf{expm1}\left(-x\right)}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{-1}{\mathsf{expm1}\left(-x\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 90.6%

    \[\leadsto \frac{-1}{\color{blue}{x \cdot \left(x \cdot \left(0.5 + x \cdot \left(0.041666666666666664 \cdot x - 0.16666666666666666\right)\right) - 1\right)}} \]
  6. Final simplification90.6%

    \[\leadsto \frac{-1}{x \cdot \left(x \cdot \left(0.5 + x \cdot \left(x \cdot 0.041666666666666664 - 0.16666666666666666\right)\right) + -1\right)} \]
  7. Add Preprocessing

Alternative 4: 90.8% accurate, 13.7× speedup?

\[\begin{array}{l} \\ \frac{-1}{x \cdot \left(x \cdot \left(0.5 + x \cdot \left(x \cdot 0.041666666666666664\right)\right) + -1\right)} \end{array} \]
(FPCore (x)
 :precision binary64
 (/ -1.0 (* x (+ (* x (+ 0.5 (* x (* x 0.041666666666666664)))) -1.0))))
double code(double x) {
	return -1.0 / (x * ((x * (0.5 + (x * (x * 0.041666666666666664)))) + -1.0));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (-1.0d0) / (x * ((x * (0.5d0 + (x * (x * 0.041666666666666664d0)))) + (-1.0d0)))
end function
public static double code(double x) {
	return -1.0 / (x * ((x * (0.5 + (x * (x * 0.041666666666666664)))) + -1.0));
}
def code(x):
	return -1.0 / (x * ((x * (0.5 + (x * (x * 0.041666666666666664)))) + -1.0))
function code(x)
	return Float64(-1.0 / Float64(x * Float64(Float64(x * Float64(0.5 + Float64(x * Float64(x * 0.041666666666666664)))) + -1.0)))
end
function tmp = code(x)
	tmp = -1.0 / (x * ((x * (0.5 + (x * (x * 0.041666666666666664)))) + -1.0));
end
code[x_] := N[(-1.0 / N[(x * N[(N[(x * N[(0.5 + N[(x * N[(x * 0.041666666666666664), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-1}{x \cdot \left(x \cdot \left(0.5 + x \cdot \left(x \cdot 0.041666666666666664\right)\right) + -1\right)}
\end{array}
Derivation
  1. Initial program 35.7%

    \[\frac{e^{x}}{e^{x} - 1} \]
  2. Step-by-step derivation
    1. sub-neg35.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} + \left(-1\right)}} \]
    2. +-commutative35.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{\left(-1\right) + e^{x}}} \]
    3. rgt-mult-inverse4.5%

      \[\leadsto \frac{e^{x}}{\left(-\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}\right) + e^{x}} \]
    4. exp-neg4.5%

      \[\leadsto \frac{e^{x}}{\left(-e^{x} \cdot \color{blue}{e^{-x}}\right) + e^{x}} \]
    5. distribute-rgt-neg-out4.5%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(-e^{-x}\right)} + e^{x}} \]
    6. *-rgt-identity4.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(-e^{-x}\right) + \color{blue}{e^{x} \cdot 1}} \]
    7. distribute-lft-in4.5%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(\left(-e^{-x}\right) + 1\right)}} \]
    8. neg-sub04.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(\color{blue}{\left(0 - e^{-x}\right)} + 1\right)} \]
    9. associate-+l-4.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(0 - \left(e^{-x} - 1\right)\right)}} \]
    10. neg-sub04.1%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(-\left(e^{-x} - 1\right)\right)}} \]
    11. associate-/r*4.1%

      \[\leadsto \color{blue}{\frac{\frac{e^{x}}{e^{x}}}{-\left(e^{-x} - 1\right)}} \]
    12. *-rgt-identity4.1%

      \[\leadsto \frac{\frac{\color{blue}{e^{x} \cdot 1}}{e^{x}}}{-\left(e^{-x} - 1\right)} \]
    13. associate-*r/4.1%

      \[\leadsto \frac{\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}}{-\left(e^{-x} - 1\right)} \]
    14. rgt-mult-inverse35.3%

      \[\leadsto \frac{\color{blue}{1}}{-\left(e^{-x} - 1\right)} \]
    15. distribute-frac-neg235.3%

      \[\leadsto \color{blue}{-\frac{1}{e^{-x} - 1}} \]
    16. distribute-neg-frac35.3%

      \[\leadsto \color{blue}{\frac{-1}{e^{-x} - 1}} \]
    17. metadata-eval35.3%

      \[\leadsto \frac{\color{blue}{-1}}{e^{-x} - 1} \]
    18. expm1-define100.0%

      \[\leadsto \frac{-1}{\color{blue}{\mathsf{expm1}\left(-x\right)}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{-1}{\mathsf{expm1}\left(-x\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 90.6%

    \[\leadsto \frac{-1}{\color{blue}{x \cdot \left(x \cdot \left(0.5 + x \cdot \left(0.041666666666666664 \cdot x - 0.16666666666666666\right)\right) - 1\right)}} \]
  6. Taylor expanded in x around inf 90.4%

    \[\leadsto \frac{-1}{x \cdot \left(x \cdot \left(0.5 + x \cdot \color{blue}{\left(0.041666666666666664 \cdot x\right)}\right) - 1\right)} \]
  7. Step-by-step derivation
    1. *-commutative90.4%

      \[\leadsto \frac{-1}{x \cdot \left(x \cdot \left(0.5 + x \cdot \color{blue}{\left(x \cdot 0.041666666666666664\right)}\right) - 1\right)} \]
  8. Simplified90.4%

    \[\leadsto \frac{-1}{x \cdot \left(x \cdot \left(0.5 + x \cdot \color{blue}{\left(x \cdot 0.041666666666666664\right)}\right) - 1\right)} \]
  9. Final simplification90.4%

    \[\leadsto \frac{-1}{x \cdot \left(x \cdot \left(0.5 + x \cdot \left(x \cdot 0.041666666666666664\right)\right) + -1\right)} \]
  10. Add Preprocessing

Alternative 5: 88.6% accurate, 15.8× speedup?

\[\begin{array}{l} \\ \frac{-1}{x \cdot \left(x \cdot \left(0.5 + x \cdot -0.16666666666666666\right) + -1\right)} \end{array} \]
(FPCore (x)
 :precision binary64
 (/ -1.0 (* x (+ (* x (+ 0.5 (* x -0.16666666666666666))) -1.0))))
double code(double x) {
	return -1.0 / (x * ((x * (0.5 + (x * -0.16666666666666666))) + -1.0));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (-1.0d0) / (x * ((x * (0.5d0 + (x * (-0.16666666666666666d0)))) + (-1.0d0)))
end function
public static double code(double x) {
	return -1.0 / (x * ((x * (0.5 + (x * -0.16666666666666666))) + -1.0));
}
def code(x):
	return -1.0 / (x * ((x * (0.5 + (x * -0.16666666666666666))) + -1.0))
function code(x)
	return Float64(-1.0 / Float64(x * Float64(Float64(x * Float64(0.5 + Float64(x * -0.16666666666666666))) + -1.0)))
end
function tmp = code(x)
	tmp = -1.0 / (x * ((x * (0.5 + (x * -0.16666666666666666))) + -1.0));
end
code[x_] := N[(-1.0 / N[(x * N[(N[(x * N[(0.5 + N[(x * -0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-1}{x \cdot \left(x \cdot \left(0.5 + x \cdot -0.16666666666666666\right) + -1\right)}
\end{array}
Derivation
  1. Initial program 35.7%

    \[\frac{e^{x}}{e^{x} - 1} \]
  2. Step-by-step derivation
    1. sub-neg35.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} + \left(-1\right)}} \]
    2. +-commutative35.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{\left(-1\right) + e^{x}}} \]
    3. rgt-mult-inverse4.5%

      \[\leadsto \frac{e^{x}}{\left(-\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}\right) + e^{x}} \]
    4. exp-neg4.5%

      \[\leadsto \frac{e^{x}}{\left(-e^{x} \cdot \color{blue}{e^{-x}}\right) + e^{x}} \]
    5. distribute-rgt-neg-out4.5%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(-e^{-x}\right)} + e^{x}} \]
    6. *-rgt-identity4.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(-e^{-x}\right) + \color{blue}{e^{x} \cdot 1}} \]
    7. distribute-lft-in4.5%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(\left(-e^{-x}\right) + 1\right)}} \]
    8. neg-sub04.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(\color{blue}{\left(0 - e^{-x}\right)} + 1\right)} \]
    9. associate-+l-4.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(0 - \left(e^{-x} - 1\right)\right)}} \]
    10. neg-sub04.1%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(-\left(e^{-x} - 1\right)\right)}} \]
    11. associate-/r*4.1%

      \[\leadsto \color{blue}{\frac{\frac{e^{x}}{e^{x}}}{-\left(e^{-x} - 1\right)}} \]
    12. *-rgt-identity4.1%

      \[\leadsto \frac{\frac{\color{blue}{e^{x} \cdot 1}}{e^{x}}}{-\left(e^{-x} - 1\right)} \]
    13. associate-*r/4.1%

      \[\leadsto \frac{\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}}{-\left(e^{-x} - 1\right)} \]
    14. rgt-mult-inverse35.3%

      \[\leadsto \frac{\color{blue}{1}}{-\left(e^{-x} - 1\right)} \]
    15. distribute-frac-neg235.3%

      \[\leadsto \color{blue}{-\frac{1}{e^{-x} - 1}} \]
    16. distribute-neg-frac35.3%

      \[\leadsto \color{blue}{\frac{-1}{e^{-x} - 1}} \]
    17. metadata-eval35.3%

      \[\leadsto \frac{\color{blue}{-1}}{e^{-x} - 1} \]
    18. expm1-define100.0%

      \[\leadsto \frac{-1}{\color{blue}{\mathsf{expm1}\left(-x\right)}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{-1}{\mathsf{expm1}\left(-x\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 88.3%

    \[\leadsto \frac{-1}{\color{blue}{x \cdot \left(x \cdot \left(0.5 + -0.16666666666666666 \cdot x\right) - 1\right)}} \]
  6. Final simplification88.3%

    \[\leadsto \frac{-1}{x \cdot \left(x \cdot \left(0.5 + x \cdot -0.16666666666666666\right) + -1\right)} \]
  7. Add Preprocessing

Alternative 6: 83.1% accurate, 22.8× speedup?

\[\begin{array}{l} \\ \frac{-1}{x \cdot \left(x \cdot 0.5 + -1\right)} \end{array} \]
(FPCore (x) :precision binary64 (/ -1.0 (* x (+ (* x 0.5) -1.0))))
double code(double x) {
	return -1.0 / (x * ((x * 0.5) + -1.0));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (-1.0d0) / (x * ((x * 0.5d0) + (-1.0d0)))
end function
public static double code(double x) {
	return -1.0 / (x * ((x * 0.5) + -1.0));
}
def code(x):
	return -1.0 / (x * ((x * 0.5) + -1.0))
function code(x)
	return Float64(-1.0 / Float64(x * Float64(Float64(x * 0.5) + -1.0)))
end
function tmp = code(x)
	tmp = -1.0 / (x * ((x * 0.5) + -1.0));
end
code[x_] := N[(-1.0 / N[(x * N[(N[(x * 0.5), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-1}{x \cdot \left(x \cdot 0.5 + -1\right)}
\end{array}
Derivation
  1. Initial program 35.7%

    \[\frac{e^{x}}{e^{x} - 1} \]
  2. Step-by-step derivation
    1. sub-neg35.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} + \left(-1\right)}} \]
    2. +-commutative35.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{\left(-1\right) + e^{x}}} \]
    3. rgt-mult-inverse4.5%

      \[\leadsto \frac{e^{x}}{\left(-\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}\right) + e^{x}} \]
    4. exp-neg4.5%

      \[\leadsto \frac{e^{x}}{\left(-e^{x} \cdot \color{blue}{e^{-x}}\right) + e^{x}} \]
    5. distribute-rgt-neg-out4.5%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(-e^{-x}\right)} + e^{x}} \]
    6. *-rgt-identity4.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(-e^{-x}\right) + \color{blue}{e^{x} \cdot 1}} \]
    7. distribute-lft-in4.5%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(\left(-e^{-x}\right) + 1\right)}} \]
    8. neg-sub04.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(\color{blue}{\left(0 - e^{-x}\right)} + 1\right)} \]
    9. associate-+l-4.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(0 - \left(e^{-x} - 1\right)\right)}} \]
    10. neg-sub04.1%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(-\left(e^{-x} - 1\right)\right)}} \]
    11. associate-/r*4.1%

      \[\leadsto \color{blue}{\frac{\frac{e^{x}}{e^{x}}}{-\left(e^{-x} - 1\right)}} \]
    12. *-rgt-identity4.1%

      \[\leadsto \frac{\frac{\color{blue}{e^{x} \cdot 1}}{e^{x}}}{-\left(e^{-x} - 1\right)} \]
    13. associate-*r/4.1%

      \[\leadsto \frac{\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}}{-\left(e^{-x} - 1\right)} \]
    14. rgt-mult-inverse35.3%

      \[\leadsto \frac{\color{blue}{1}}{-\left(e^{-x} - 1\right)} \]
    15. distribute-frac-neg235.3%

      \[\leadsto \color{blue}{-\frac{1}{e^{-x} - 1}} \]
    16. distribute-neg-frac35.3%

      \[\leadsto \color{blue}{\frac{-1}{e^{-x} - 1}} \]
    17. metadata-eval35.3%

      \[\leadsto \frac{\color{blue}{-1}}{e^{-x} - 1} \]
    18. expm1-define100.0%

      \[\leadsto \frac{-1}{\color{blue}{\mathsf{expm1}\left(-x\right)}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{-1}{\mathsf{expm1}\left(-x\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 82.2%

    \[\leadsto \frac{-1}{\color{blue}{x \cdot \left(0.5 \cdot x - 1\right)}} \]
  6. Final simplification82.2%

    \[\leadsto \frac{-1}{x \cdot \left(x \cdot 0.5 + -1\right)} \]
  7. Add Preprocessing

Alternative 7: 67.2% accurate, 22.8× speedup?

\[\begin{array}{l} \\ x \cdot 0.08333333333333333 + \left(0.5 + \frac{1}{x}\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (+ (* x 0.08333333333333333) (+ 0.5 (/ 1.0 x))))
double code(double x) {
	return (x * 0.08333333333333333) + (0.5 + (1.0 / x));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (x * 0.08333333333333333d0) + (0.5d0 + (1.0d0 / x))
end function
public static double code(double x) {
	return (x * 0.08333333333333333) + (0.5 + (1.0 / x));
}
def code(x):
	return (x * 0.08333333333333333) + (0.5 + (1.0 / x))
function code(x)
	return Float64(Float64(x * 0.08333333333333333) + Float64(0.5 + Float64(1.0 / x)))
end
function tmp = code(x)
	tmp = (x * 0.08333333333333333) + (0.5 + (1.0 / x));
end
code[x_] := N[(N[(x * 0.08333333333333333), $MachinePrecision] + N[(0.5 + N[(1.0 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x \cdot 0.08333333333333333 + \left(0.5 + \frac{1}{x}\right)
\end{array}
Derivation
  1. Initial program 35.7%

    \[\frac{e^{x}}{e^{x} - 1} \]
  2. Step-by-step derivation
    1. sub-neg35.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} + \left(-1\right)}} \]
    2. +-commutative35.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{\left(-1\right) + e^{x}}} \]
    3. rgt-mult-inverse4.5%

      \[\leadsto \frac{e^{x}}{\left(-\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}\right) + e^{x}} \]
    4. exp-neg4.5%

      \[\leadsto \frac{e^{x}}{\left(-e^{x} \cdot \color{blue}{e^{-x}}\right) + e^{x}} \]
    5. distribute-rgt-neg-out4.5%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(-e^{-x}\right)} + e^{x}} \]
    6. *-rgt-identity4.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(-e^{-x}\right) + \color{blue}{e^{x} \cdot 1}} \]
    7. distribute-lft-in4.5%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(\left(-e^{-x}\right) + 1\right)}} \]
    8. neg-sub04.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(\color{blue}{\left(0 - e^{-x}\right)} + 1\right)} \]
    9. associate-+l-4.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(0 - \left(e^{-x} - 1\right)\right)}} \]
    10. neg-sub04.1%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(-\left(e^{-x} - 1\right)\right)}} \]
    11. associate-/r*4.1%

      \[\leadsto \color{blue}{\frac{\frac{e^{x}}{e^{x}}}{-\left(e^{-x} - 1\right)}} \]
    12. *-rgt-identity4.1%

      \[\leadsto \frac{\frac{\color{blue}{e^{x} \cdot 1}}{e^{x}}}{-\left(e^{-x} - 1\right)} \]
    13. associate-*r/4.1%

      \[\leadsto \frac{\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}}{-\left(e^{-x} - 1\right)} \]
    14. rgt-mult-inverse35.3%

      \[\leadsto \frac{\color{blue}{1}}{-\left(e^{-x} - 1\right)} \]
    15. distribute-frac-neg235.3%

      \[\leadsto \color{blue}{-\frac{1}{e^{-x} - 1}} \]
    16. distribute-neg-frac35.3%

      \[\leadsto \color{blue}{\frac{-1}{e^{-x} - 1}} \]
    17. metadata-eval35.3%

      \[\leadsto \frac{\color{blue}{-1}}{e^{-x} - 1} \]
    18. expm1-define100.0%

      \[\leadsto \frac{-1}{\color{blue}{\mathsf{expm1}\left(-x\right)}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{-1}{\mathsf{expm1}\left(-x\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 68.6%

    \[\leadsto \color{blue}{\frac{1 + x \cdot \left(0.5 + 0.08333333333333333 \cdot x\right)}{x}} \]
  6. Step-by-step derivation
    1. *-commutative68.6%

      \[\leadsto \frac{1 + x \cdot \left(0.5 + \color{blue}{x \cdot 0.08333333333333333}\right)}{x} \]
  7. Simplified68.6%

    \[\leadsto \color{blue}{\frac{1 + x \cdot \left(0.5 + x \cdot 0.08333333333333333\right)}{x}} \]
  8. Taylor expanded in x around -inf 37.2%

    \[\leadsto \color{blue}{-1 \cdot \left(x \cdot \left(-1 \cdot \frac{0.5 + \frac{1}{x}}{x} - 0.08333333333333333\right)\right)} \]
  9. Step-by-step derivation
    1. mul-1-neg37.2%

      \[\leadsto \color{blue}{-x \cdot \left(-1 \cdot \frac{0.5 + \frac{1}{x}}{x} - 0.08333333333333333\right)} \]
    2. distribute-rgt-neg-in37.2%

      \[\leadsto \color{blue}{x \cdot \left(-\left(-1 \cdot \frac{0.5 + \frac{1}{x}}{x} - 0.08333333333333333\right)\right)} \]
    3. sub-neg37.2%

      \[\leadsto x \cdot \left(-\color{blue}{\left(-1 \cdot \frac{0.5 + \frac{1}{x}}{x} + \left(-0.08333333333333333\right)\right)}\right) \]
    4. associate-*r/37.2%

      \[\leadsto x \cdot \left(-\left(\color{blue}{\frac{-1 \cdot \left(0.5 + \frac{1}{x}\right)}{x}} + \left(-0.08333333333333333\right)\right)\right) \]
    5. distribute-lft-in37.2%

      \[\leadsto x \cdot \left(-\left(\frac{\color{blue}{-1 \cdot 0.5 + -1 \cdot \frac{1}{x}}}{x} + \left(-0.08333333333333333\right)\right)\right) \]
    6. metadata-eval37.2%

      \[\leadsto x \cdot \left(-\left(\frac{\color{blue}{-0.5} + -1 \cdot \frac{1}{x}}{x} + \left(-0.08333333333333333\right)\right)\right) \]
    7. associate-*r/37.2%

      \[\leadsto x \cdot \left(-\left(\frac{-0.5 + \color{blue}{\frac{-1 \cdot 1}{x}}}{x} + \left(-0.08333333333333333\right)\right)\right) \]
    8. metadata-eval37.2%

      \[\leadsto x \cdot \left(-\left(\frac{-0.5 + \frac{\color{blue}{-1}}{x}}{x} + \left(-0.08333333333333333\right)\right)\right) \]
    9. metadata-eval37.2%

      \[\leadsto x \cdot \left(-\left(\frac{-0.5 + \frac{-1}{x}}{x} + \color{blue}{-0.08333333333333333}\right)\right) \]
  10. Simplified37.2%

    \[\leadsto \color{blue}{x \cdot \left(-\left(\frac{-0.5 + \frac{-1}{x}}{x} + -0.08333333333333333\right)\right)} \]
  11. Step-by-step derivation
    1. distribute-neg-in37.2%

      \[\leadsto x \cdot \color{blue}{\left(\left(-\frac{-0.5 + \frac{-1}{x}}{x}\right) + \left(--0.08333333333333333\right)\right)} \]
    2. div-inv37.1%

      \[\leadsto x \cdot \left(\left(-\color{blue}{\left(-0.5 + \frac{-1}{x}\right) \cdot \frac{1}{x}}\right) + \left(--0.08333333333333333\right)\right) \]
    3. distribute-rgt-neg-in37.1%

      \[\leadsto x \cdot \left(\color{blue}{\left(-0.5 + \frac{-1}{x}\right) \cdot \left(-\frac{1}{x}\right)} + \left(--0.08333333333333333\right)\right) \]
    4. mul-1-neg37.1%

      \[\leadsto x \cdot \left(\left(-0.5 + \frac{-1}{x}\right) \cdot \color{blue}{\left(-1 \cdot \frac{1}{x}\right)} + \left(--0.08333333333333333\right)\right) \]
    5. div-inv37.1%

      \[\leadsto x \cdot \left(\left(-0.5 + \frac{-1}{x}\right) \cdot \color{blue}{\frac{-1}{x}} + \left(--0.08333333333333333\right)\right) \]
    6. add-sqr-sqrt16.5%

      \[\leadsto x \cdot \left(\left(-0.5 + \frac{-1}{x}\right) \cdot \color{blue}{\left(\sqrt{\frac{-1}{x}} \cdot \sqrt{\frac{-1}{x}}\right)} + \left(--0.08333333333333333\right)\right) \]
    7. sqrt-unprod16.8%

      \[\leadsto x \cdot \left(\left(-0.5 + \frac{-1}{x}\right) \cdot \color{blue}{\sqrt{\frac{-1}{x} \cdot \frac{-1}{x}}} + \left(--0.08333333333333333\right)\right) \]
    8. frac-times16.7%

      \[\leadsto x \cdot \left(\left(-0.5 + \frac{-1}{x}\right) \cdot \sqrt{\color{blue}{\frac{-1 \cdot -1}{x \cdot x}}} + \left(--0.08333333333333333\right)\right) \]
    9. metadata-eval16.7%

      \[\leadsto x \cdot \left(\left(-0.5 + \frac{-1}{x}\right) \cdot \sqrt{\frac{\color{blue}{1}}{x \cdot x}} + \left(--0.08333333333333333\right)\right) \]
    10. metadata-eval16.7%

      \[\leadsto x \cdot \left(\left(-0.5 + \frac{-1}{x}\right) \cdot \sqrt{\frac{\color{blue}{1 \cdot 1}}{x \cdot x}} + \left(--0.08333333333333333\right)\right) \]
    11. frac-times16.8%

      \[\leadsto x \cdot \left(\left(-0.5 + \frac{-1}{x}\right) \cdot \sqrt{\color{blue}{\frac{1}{x} \cdot \frac{1}{x}}} + \left(--0.08333333333333333\right)\right) \]
    12. sqrt-unprod0.2%

      \[\leadsto x \cdot \left(\left(-0.5 + \frac{-1}{x}\right) \cdot \color{blue}{\left(\sqrt{\frac{1}{x}} \cdot \sqrt{\frac{1}{x}}\right)} + \left(--0.08333333333333333\right)\right) \]
    13. add-sqr-sqrt1.2%

      \[\leadsto x \cdot \left(\left(-0.5 + \frac{-1}{x}\right) \cdot \color{blue}{\frac{1}{x}} + \left(--0.08333333333333333\right)\right) \]
    14. div-inv1.2%

      \[\leadsto x \cdot \left(\color{blue}{\frac{-0.5 + \frac{-1}{x}}{x}} + \left(--0.08333333333333333\right)\right) \]
    15. sub-neg1.2%

      \[\leadsto x \cdot \color{blue}{\left(\frac{-0.5 + \frac{-1}{x}}{x} - -0.08333333333333333\right)} \]
  12. Applied egg-rr37.2%

    \[\leadsto x \cdot \color{blue}{\left(\frac{0.5 + \frac{1}{x}}{x} - -0.08333333333333333\right)} \]
  13. Step-by-step derivation
    1. pow137.2%

      \[\leadsto \color{blue}{{\left(x \cdot \left(\frac{0.5 + \frac{1}{x}}{x} - -0.08333333333333333\right)\right)}^{1}} \]
    2. sub-neg37.2%

      \[\leadsto {\left(x \cdot \color{blue}{\left(\frac{0.5 + \frac{1}{x}}{x} + \left(--0.08333333333333333\right)\right)}\right)}^{1} \]
    3. metadata-eval37.2%

      \[\leadsto {\left(x \cdot \left(\frac{0.5 + \frac{1}{x}}{x} + \color{blue}{0.08333333333333333}\right)\right)}^{1} \]
  14. Applied egg-rr37.2%

    \[\leadsto \color{blue}{{\left(x \cdot \left(\frac{0.5 + \frac{1}{x}}{x} + 0.08333333333333333\right)\right)}^{1}} \]
  15. Step-by-step derivation
    1. unpow137.2%

      \[\leadsto \color{blue}{x \cdot \left(\frac{0.5 + \frac{1}{x}}{x} + 0.08333333333333333\right)} \]
    2. +-commutative37.2%

      \[\leadsto x \cdot \color{blue}{\left(0.08333333333333333 + \frac{0.5 + \frac{1}{x}}{x}\right)} \]
    3. distribute-lft-in37.2%

      \[\leadsto \color{blue}{x \cdot 0.08333333333333333 + x \cdot \frac{0.5 + \frac{1}{x}}{x}} \]
    4. *-lft-identity37.2%

      \[\leadsto x \cdot 0.08333333333333333 + x \cdot \frac{\color{blue}{1 \cdot \left(0.5 + \frac{1}{x}\right)}}{x} \]
    5. associate-*l/37.1%

      \[\leadsto x \cdot 0.08333333333333333 + x \cdot \color{blue}{\left(\frac{1}{x} \cdot \left(0.5 + \frac{1}{x}\right)\right)} \]
    6. associate-*r*68.4%

      \[\leadsto x \cdot 0.08333333333333333 + \color{blue}{\left(x \cdot \frac{1}{x}\right) \cdot \left(0.5 + \frac{1}{x}\right)} \]
    7. rgt-mult-inverse68.6%

      \[\leadsto x \cdot 0.08333333333333333 + \color{blue}{1} \cdot \left(0.5 + \frac{1}{x}\right) \]
    8. *-lft-identity68.6%

      \[\leadsto x \cdot 0.08333333333333333 + \color{blue}{\left(0.5 + \frac{1}{x}\right)} \]
  16. Simplified68.6%

    \[\leadsto \color{blue}{x \cdot 0.08333333333333333 + \left(0.5 + \frac{1}{x}\right)} \]
  17. Add Preprocessing

Alternative 8: 67.0% accurate, 41.0× speedup?

\[\begin{array}{l} \\ 0.5 + \frac{1}{x} \end{array} \]
(FPCore (x) :precision binary64 (+ 0.5 (/ 1.0 x)))
double code(double x) {
	return 0.5 + (1.0 / x);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 0.5d0 + (1.0d0 / x)
end function
public static double code(double x) {
	return 0.5 + (1.0 / x);
}
def code(x):
	return 0.5 + (1.0 / x)
function code(x)
	return Float64(0.5 + Float64(1.0 / x))
end
function tmp = code(x)
	tmp = 0.5 + (1.0 / x);
end
code[x_] := N[(0.5 + N[(1.0 / x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0.5 + \frac{1}{x}
\end{array}
Derivation
  1. Initial program 35.7%

    \[\frac{e^{x}}{e^{x} - 1} \]
  2. Step-by-step derivation
    1. sub-neg35.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} + \left(-1\right)}} \]
    2. +-commutative35.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{\left(-1\right) + e^{x}}} \]
    3. rgt-mult-inverse4.5%

      \[\leadsto \frac{e^{x}}{\left(-\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}\right) + e^{x}} \]
    4. exp-neg4.5%

      \[\leadsto \frac{e^{x}}{\left(-e^{x} \cdot \color{blue}{e^{-x}}\right) + e^{x}} \]
    5. distribute-rgt-neg-out4.5%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(-e^{-x}\right)} + e^{x}} \]
    6. *-rgt-identity4.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(-e^{-x}\right) + \color{blue}{e^{x} \cdot 1}} \]
    7. distribute-lft-in4.5%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(\left(-e^{-x}\right) + 1\right)}} \]
    8. neg-sub04.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(\color{blue}{\left(0 - e^{-x}\right)} + 1\right)} \]
    9. associate-+l-4.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(0 - \left(e^{-x} - 1\right)\right)}} \]
    10. neg-sub04.1%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(-\left(e^{-x} - 1\right)\right)}} \]
    11. associate-/r*4.1%

      \[\leadsto \color{blue}{\frac{\frac{e^{x}}{e^{x}}}{-\left(e^{-x} - 1\right)}} \]
    12. *-rgt-identity4.1%

      \[\leadsto \frac{\frac{\color{blue}{e^{x} \cdot 1}}{e^{x}}}{-\left(e^{-x} - 1\right)} \]
    13. associate-*r/4.1%

      \[\leadsto \frac{\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}}{-\left(e^{-x} - 1\right)} \]
    14. rgt-mult-inverse35.3%

      \[\leadsto \frac{\color{blue}{1}}{-\left(e^{-x} - 1\right)} \]
    15. distribute-frac-neg235.3%

      \[\leadsto \color{blue}{-\frac{1}{e^{-x} - 1}} \]
    16. distribute-neg-frac35.3%

      \[\leadsto \color{blue}{\frac{-1}{e^{-x} - 1}} \]
    17. metadata-eval35.3%

      \[\leadsto \frac{\color{blue}{-1}}{e^{-x} - 1} \]
    18. expm1-define100.0%

      \[\leadsto \frac{-1}{\color{blue}{\mathsf{expm1}\left(-x\right)}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{-1}{\mathsf{expm1}\left(-x\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 68.6%

    \[\leadsto \color{blue}{\frac{1 + 0.5 \cdot x}{x}} \]
  6. Step-by-step derivation
    1. *-commutative68.6%

      \[\leadsto \frac{1 + \color{blue}{x \cdot 0.5}}{x} \]
  7. Simplified68.6%

    \[\leadsto \color{blue}{\frac{1 + x \cdot 0.5}{x}} \]
  8. Taylor expanded in x around 0 68.6%

    \[\leadsto \color{blue}{\frac{1 + 0.5 \cdot x}{x}} \]
  9. Step-by-step derivation
    1. +-commutative68.6%

      \[\leadsto \frac{\color{blue}{0.5 \cdot x + 1}}{x} \]
    2. *-commutative68.6%

      \[\leadsto \frac{\color{blue}{x \cdot 0.5} + 1}{x} \]
    3. fma-undefine68.6%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, 0.5, 1\right)}}{x} \]
    4. *-lft-identity68.6%

      \[\leadsto \frac{\color{blue}{1 \cdot \mathsf{fma}\left(x, 0.5, 1\right)}}{x} \]
    5. associate-*l/68.6%

      \[\leadsto \color{blue}{\frac{1}{x} \cdot \mathsf{fma}\left(x, 0.5, 1\right)} \]
    6. fma-undefine68.6%

      \[\leadsto \frac{1}{x} \cdot \color{blue}{\left(x \cdot 0.5 + 1\right)} \]
    7. distribute-rgt-in68.6%

      \[\leadsto \color{blue}{\left(x \cdot 0.5\right) \cdot \frac{1}{x} + 1 \cdot \frac{1}{x}} \]
    8. associate-*r*68.6%

      \[\leadsto \color{blue}{x \cdot \left(0.5 \cdot \frac{1}{x}\right)} + 1 \cdot \frac{1}{x} \]
    9. *-commutative68.6%

      \[\leadsto x \cdot \color{blue}{\left(\frac{1}{x} \cdot 0.5\right)} + 1 \cdot \frac{1}{x} \]
    10. associate-*r*68.6%

      \[\leadsto \color{blue}{\left(x \cdot \frac{1}{x}\right) \cdot 0.5} + 1 \cdot \frac{1}{x} \]
    11. rgt-mult-inverse68.6%

      \[\leadsto \color{blue}{1} \cdot 0.5 + 1 \cdot \frac{1}{x} \]
    12. metadata-eval68.6%

      \[\leadsto \color{blue}{0.5} + 1 \cdot \frac{1}{x} \]
    13. *-lft-identity68.6%

      \[\leadsto 0.5 + \color{blue}{\frac{1}{x}} \]
    14. +-commutative68.6%

      \[\leadsto \color{blue}{\frac{1}{x} + 0.5} \]
  10. Simplified68.6%

    \[\leadsto \color{blue}{\frac{1}{x} + 0.5} \]
  11. Final simplification68.6%

    \[\leadsto 0.5 + \frac{1}{x} \]
  12. Add Preprocessing

Alternative 9: 67.0% accurate, 68.3× speedup?

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

\\
\frac{1}{x}
\end{array}
Derivation
  1. Initial program 35.7%

    \[\frac{e^{x}}{e^{x} - 1} \]
  2. Step-by-step derivation
    1. sub-neg35.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} + \left(-1\right)}} \]
    2. +-commutative35.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{\left(-1\right) + e^{x}}} \]
    3. rgt-mult-inverse4.5%

      \[\leadsto \frac{e^{x}}{\left(-\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}\right) + e^{x}} \]
    4. exp-neg4.5%

      \[\leadsto \frac{e^{x}}{\left(-e^{x} \cdot \color{blue}{e^{-x}}\right) + e^{x}} \]
    5. distribute-rgt-neg-out4.5%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(-e^{-x}\right)} + e^{x}} \]
    6. *-rgt-identity4.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(-e^{-x}\right) + \color{blue}{e^{x} \cdot 1}} \]
    7. distribute-lft-in4.5%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(\left(-e^{-x}\right) + 1\right)}} \]
    8. neg-sub04.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(\color{blue}{\left(0 - e^{-x}\right)} + 1\right)} \]
    9. associate-+l-4.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(0 - \left(e^{-x} - 1\right)\right)}} \]
    10. neg-sub04.1%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(-\left(e^{-x} - 1\right)\right)}} \]
    11. associate-/r*4.1%

      \[\leadsto \color{blue}{\frac{\frac{e^{x}}{e^{x}}}{-\left(e^{-x} - 1\right)}} \]
    12. *-rgt-identity4.1%

      \[\leadsto \frac{\frac{\color{blue}{e^{x} \cdot 1}}{e^{x}}}{-\left(e^{-x} - 1\right)} \]
    13. associate-*r/4.1%

      \[\leadsto \frac{\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}}{-\left(e^{-x} - 1\right)} \]
    14. rgt-mult-inverse35.3%

      \[\leadsto \frac{\color{blue}{1}}{-\left(e^{-x} - 1\right)} \]
    15. distribute-frac-neg235.3%

      \[\leadsto \color{blue}{-\frac{1}{e^{-x} - 1}} \]
    16. distribute-neg-frac35.3%

      \[\leadsto \color{blue}{\frac{-1}{e^{-x} - 1}} \]
    17. metadata-eval35.3%

      \[\leadsto \frac{\color{blue}{-1}}{e^{-x} - 1} \]
    18. expm1-define100.0%

      \[\leadsto \frac{-1}{\color{blue}{\mathsf{expm1}\left(-x\right)}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{-1}{\mathsf{expm1}\left(-x\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 68.6%

    \[\leadsto \color{blue}{\frac{1}{x}} \]
  6. Add Preprocessing

Alternative 10: 3.3% accurate, 205.0× speedup?

\[\begin{array}{l} \\ 0.5 \end{array} \]
(FPCore (x) :precision binary64 0.5)
double code(double x) {
	return 0.5;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 0.5d0
end function
public static double code(double x) {
	return 0.5;
}
def code(x):
	return 0.5
function code(x)
	return 0.5
end
function tmp = code(x)
	tmp = 0.5;
end
code[x_] := 0.5
\begin{array}{l}

\\
0.5
\end{array}
Derivation
  1. Initial program 35.7%

    \[\frac{e^{x}}{e^{x} - 1} \]
  2. Step-by-step derivation
    1. sub-neg35.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} + \left(-1\right)}} \]
    2. +-commutative35.7%

      \[\leadsto \frac{e^{x}}{\color{blue}{\left(-1\right) + e^{x}}} \]
    3. rgt-mult-inverse4.5%

      \[\leadsto \frac{e^{x}}{\left(-\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}\right) + e^{x}} \]
    4. exp-neg4.5%

      \[\leadsto \frac{e^{x}}{\left(-e^{x} \cdot \color{blue}{e^{-x}}\right) + e^{x}} \]
    5. distribute-rgt-neg-out4.5%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(-e^{-x}\right)} + e^{x}} \]
    6. *-rgt-identity4.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(-e^{-x}\right) + \color{blue}{e^{x} \cdot 1}} \]
    7. distribute-lft-in4.5%

      \[\leadsto \frac{e^{x}}{\color{blue}{e^{x} \cdot \left(\left(-e^{-x}\right) + 1\right)}} \]
    8. neg-sub04.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \left(\color{blue}{\left(0 - e^{-x}\right)} + 1\right)} \]
    9. associate-+l-4.5%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(0 - \left(e^{-x} - 1\right)\right)}} \]
    10. neg-sub04.1%

      \[\leadsto \frac{e^{x}}{e^{x} \cdot \color{blue}{\left(-\left(e^{-x} - 1\right)\right)}} \]
    11. associate-/r*4.1%

      \[\leadsto \color{blue}{\frac{\frac{e^{x}}{e^{x}}}{-\left(e^{-x} - 1\right)}} \]
    12. *-rgt-identity4.1%

      \[\leadsto \frac{\frac{\color{blue}{e^{x} \cdot 1}}{e^{x}}}{-\left(e^{-x} - 1\right)} \]
    13. associate-*r/4.1%

      \[\leadsto \frac{\color{blue}{e^{x} \cdot \frac{1}{e^{x}}}}{-\left(e^{-x} - 1\right)} \]
    14. rgt-mult-inverse35.3%

      \[\leadsto \frac{\color{blue}{1}}{-\left(e^{-x} - 1\right)} \]
    15. distribute-frac-neg235.3%

      \[\leadsto \color{blue}{-\frac{1}{e^{-x} - 1}} \]
    16. distribute-neg-frac35.3%

      \[\leadsto \color{blue}{\frac{-1}{e^{-x} - 1}} \]
    17. metadata-eval35.3%

      \[\leadsto \frac{\color{blue}{-1}}{e^{-x} - 1} \]
    18. expm1-define100.0%

      \[\leadsto \frac{-1}{\color{blue}{\mathsf{expm1}\left(-x\right)}} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{-1}{\mathsf{expm1}\left(-x\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 68.6%

    \[\leadsto \color{blue}{\frac{1 + 0.5 \cdot x}{x}} \]
  6. Step-by-step derivation
    1. *-commutative68.6%

      \[\leadsto \frac{1 + \color{blue}{x \cdot 0.5}}{x} \]
  7. Simplified68.6%

    \[\leadsto \color{blue}{\frac{1 + x \cdot 0.5}{x}} \]
  8. Taylor expanded in x around inf 3.3%

    \[\leadsto \color{blue}{0.5} \]
  9. Add Preprocessing

Developer Target 1: 100.0% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \frac{-1}{\mathsf{expm1}\left(-x\right)} \end{array} \]
(FPCore (x) :precision binary64 (/ (- 1.0) (expm1 (- x))))
double code(double x) {
	return -1.0 / expm1(-x);
}
public static double code(double x) {
	return -1.0 / Math.expm1(-x);
}
def code(x):
	return -1.0 / math.expm1(-x)
function code(x)
	return Float64(Float64(-1.0) / expm1(Float64(-x)))
end
code[x_] := N[((-1.0) / N[(Exp[(-x)] - 1), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-1}{\mathsf{expm1}\left(-x\right)}
\end{array}

Reproduce

?
herbie shell --seed 2024136 
(FPCore (x)
  :name "expq2 (section 3.11)"
  :precision binary64
  :pre (> 710.0 x)

  :alt
  (! :herbie-platform default (/ (- 1) (expm1 (- x))))

  (/ (exp x) (- (exp x) 1.0)))