Numeric.SpecFunctions:invIncompleteGamma from math-functions-0.1.5.2, B

Percentage Accurate: 72.8% → 99.9%
Time: 12.0s
Alternatives: 10
Speedup: 1.0×

Specification

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

\\
1 - \log \left(1 - \frac{x - y}{1 - y}\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 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: 72.8% accurate, 1.0× speedup?

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

\\
1 - \log \left(1 - \frac{x - y}{1 - y}\right)
\end{array}

Alternative 1: 99.9% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{x - y}{1 - y} \leq 0.4:\\ \;\;\;\;1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{\left(x + -1\right) + \frac{\left(x + -1\right) + \frac{-1 + \left(x + \frac{x + -1}{y}\right)}{y}}{y}}{y}\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= (/ (- x y) (- 1.0 y)) 0.4)
   (- 1.0 (log1p (/ (- x y) (+ y -1.0))))
   (-
    1.0
    (log
     (/
      (+ (+ x -1.0) (/ (+ (+ x -1.0) (/ (+ -1.0 (+ x (/ (+ x -1.0) y))) y)) y))
      y)))))
double code(double x, double y) {
	double tmp;
	if (((x - y) / (1.0 - y)) <= 0.4) {
		tmp = 1.0 - log1p(((x - y) / (y + -1.0)));
	} else {
		tmp = 1.0 - log((((x + -1.0) + (((x + -1.0) + ((-1.0 + (x + ((x + -1.0) / y))) / y)) / y)) / y));
	}
	return tmp;
}
public static double code(double x, double y) {
	double tmp;
	if (((x - y) / (1.0 - y)) <= 0.4) {
		tmp = 1.0 - Math.log1p(((x - y) / (y + -1.0)));
	} else {
		tmp = 1.0 - Math.log((((x + -1.0) + (((x + -1.0) + ((-1.0 + (x + ((x + -1.0) / y))) / y)) / y)) / y));
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if ((x - y) / (1.0 - y)) <= 0.4:
		tmp = 1.0 - math.log1p(((x - y) / (y + -1.0)))
	else:
		tmp = 1.0 - math.log((((x + -1.0) + (((x + -1.0) + ((-1.0 + (x + ((x + -1.0) / y))) / y)) / y)) / y))
	return tmp
function code(x, y)
	tmp = 0.0
	if (Float64(Float64(x - y) / Float64(1.0 - y)) <= 0.4)
		tmp = Float64(1.0 - log1p(Float64(Float64(x - y) / Float64(y + -1.0))));
	else
		tmp = Float64(1.0 - log(Float64(Float64(Float64(x + -1.0) + Float64(Float64(Float64(x + -1.0) + Float64(Float64(-1.0 + Float64(x + Float64(Float64(x + -1.0) / y))) / y)) / y)) / y)));
	end
	return tmp
end
code[x_, y_] := If[LessEqual[N[(N[(x - y), $MachinePrecision] / N[(1.0 - y), $MachinePrecision]), $MachinePrecision], 0.4], N[(1.0 - N[Log[1 + N[(N[(x - y), $MachinePrecision] / N[(y + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(1.0 - N[Log[N[(N[(N[(x + -1.0), $MachinePrecision] + N[(N[(N[(x + -1.0), $MachinePrecision] + N[(N[(-1.0 + N[(x + N[(N[(x + -1.0), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{x - y}{1 - y} \leq 0.4:\\
\;\;\;\;1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)\\

\mathbf{else}:\\
\;\;\;\;1 - \log \left(\frac{\left(x + -1\right) + \frac{\left(x + -1\right) + \frac{-1 + \left(x + \frac{x + -1}{y}\right)}{y}}{y}}{y}\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y)) < 0.40000000000000002

    1. Initial program 100.0%

      \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      2. accelerator-lowering-log1p.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      3. distribute-neg-frac2N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
      4. /-lowering-/.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
      5. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
      6. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 + \left(\mathsf{neg}\left(y\right)\right)\right)\right)\right)\right)\right)\right) \]
      7. +-commutativeN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(\left(\mathsf{neg}\left(y\right)\right) + 1\right)\right)\right)\right)\right)\right) \]
      8. distribute-neg-inN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(y\right)\right)\right)\right) + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
      9. remove-double-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
      10. metadata-evalN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
      11. +-lowering-+.f64100.0%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
    4. Applied egg-rr100.0%

      \[\leadsto 1 - \color{blue}{\mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]

    if 0.40000000000000002 < (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y))

    1. Initial program 7.2%

      \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in y around -inf

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\color{blue}{\left(-1 \cdot \frac{\left(1 + -1 \cdot \frac{\left(x + -1 \cdot \frac{1 + \left(-1 \cdot x + -1 \cdot \frac{x - 1}{y}\right)}{y}\right) - 1}{y}\right) - x}{y}\right)}\right)\right) \]
    4. Simplified100.0%

      \[\leadsto 1 - \log \color{blue}{\left(\frac{\frac{\frac{-1 + \left(x + \frac{-1 + x}{y}\right)}{y} + \left(-1 + x\right)}{y} + \left(-1 + x\right)}{y}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification100.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x - y}{1 - y} \leq 0.4:\\ \;\;\;\;1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{\left(x + -1\right) + \frac{\left(x + -1\right) + \frac{-1 + \left(x + \frac{x + -1}{y}\right)}{y}}{y}}{y}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 99.9% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{x - y}{1 - y} \leq 0.9999:\\ \;\;\;\;1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{-1 + \left(x + \frac{x + -1}{y}\right)}{y}\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= (/ (- x y) (- 1.0 y)) 0.9999)
   (- 1.0 (log1p (/ (- x y) (+ y -1.0))))
   (- 1.0 (log (/ (+ -1.0 (+ x (/ (+ x -1.0) y))) y)))))
double code(double x, double y) {
	double tmp;
	if (((x - y) / (1.0 - y)) <= 0.9999) {
		tmp = 1.0 - log1p(((x - y) / (y + -1.0)));
	} else {
		tmp = 1.0 - log(((-1.0 + (x + ((x + -1.0) / y))) / y));
	}
	return tmp;
}
public static double code(double x, double y) {
	double tmp;
	if (((x - y) / (1.0 - y)) <= 0.9999) {
		tmp = 1.0 - Math.log1p(((x - y) / (y + -1.0)));
	} else {
		tmp = 1.0 - Math.log(((-1.0 + (x + ((x + -1.0) / y))) / y));
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if ((x - y) / (1.0 - y)) <= 0.9999:
		tmp = 1.0 - math.log1p(((x - y) / (y + -1.0)))
	else:
		tmp = 1.0 - math.log(((-1.0 + (x + ((x + -1.0) / y))) / y))
	return tmp
function code(x, y)
	tmp = 0.0
	if (Float64(Float64(x - y) / Float64(1.0 - y)) <= 0.9999)
		tmp = Float64(1.0 - log1p(Float64(Float64(x - y) / Float64(y + -1.0))));
	else
		tmp = Float64(1.0 - log(Float64(Float64(-1.0 + Float64(x + Float64(Float64(x + -1.0) / y))) / y)));
	end
	return tmp
end
code[x_, y_] := If[LessEqual[N[(N[(x - y), $MachinePrecision] / N[(1.0 - y), $MachinePrecision]), $MachinePrecision], 0.9999], N[(1.0 - N[Log[1 + N[(N[(x - y), $MachinePrecision] / N[(y + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(1.0 - N[Log[N[(N[(-1.0 + N[(x + N[(N[(x + -1.0), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{x - y}{1 - y} \leq 0.9999:\\
\;\;\;\;1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)\\

\mathbf{else}:\\
\;\;\;\;1 - \log \left(\frac{-1 + \left(x + \frac{x + -1}{y}\right)}{y}\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y)) < 0.99990000000000001

    1. Initial program 99.9%

      \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      2. accelerator-lowering-log1p.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      3. distribute-neg-frac2N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
      4. /-lowering-/.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
      5. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
      6. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 + \left(\mathsf{neg}\left(y\right)\right)\right)\right)\right)\right)\right)\right) \]
      7. +-commutativeN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(\left(\mathsf{neg}\left(y\right)\right) + 1\right)\right)\right)\right)\right)\right) \]
      8. distribute-neg-inN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(y\right)\right)\right)\right) + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
      9. remove-double-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
      10. metadata-evalN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
      11. +-lowering-+.f6499.9%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
    4. Applied egg-rr99.9%

      \[\leadsto 1 - \color{blue}{\mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]

    if 0.99990000000000001 < (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y))

    1. Initial program 5.1%

      \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in y around -inf

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\color{blue}{\left(-1 \cdot \frac{\left(1 + -1 \cdot \frac{x - 1}{y}\right) - x}{y}\right)}\right)\right) \]
    4. Step-by-step derivation
      1. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(-1 \cdot \frac{\left(1 + -1 \cdot \frac{x - 1}{y}\right) + \left(\mathsf{neg}\left(x\right)\right)}{y}\right)\right)\right) \]
      2. mul-1-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(-1 \cdot \frac{\left(1 + -1 \cdot \frac{x - 1}{y}\right) + -1 \cdot x}{y}\right)\right)\right) \]
      3. associate-+r+N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(-1 \cdot \frac{1 + \left(-1 \cdot \frac{x - 1}{y} + -1 \cdot x\right)}{y}\right)\right)\right) \]
      4. +-commutativeN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(-1 \cdot \frac{1 + \left(-1 \cdot x + -1 \cdot \frac{x - 1}{y}\right)}{y}\right)\right)\right) \]
      5. associate-*r/N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{-1 \cdot \left(1 + \left(-1 \cdot x + -1 \cdot \frac{x - 1}{y}\right)\right)}{y}\right)\right)\right) \]
    5. Simplified100.0%

      \[\leadsto 1 - \log \color{blue}{\left(\frac{-1 + \left(x + \frac{-1 + x}{y}\right)}{y}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x - y}{1 - y} \leq 0.9999:\\ \;\;\;\;1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{-1 + \left(x + \frac{x + -1}{y}\right)}{y}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 99.8% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{x - y}{1 - y} \leq 0.9999:\\ \;\;\;\;1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{x + -1}{y}\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= (/ (- x y) (- 1.0 y)) 0.9999)
   (- 1.0 (log1p (/ (- x y) (+ y -1.0))))
   (- 1.0 (log (/ (+ x -1.0) y)))))
double code(double x, double y) {
	double tmp;
	if (((x - y) / (1.0 - y)) <= 0.9999) {
		tmp = 1.0 - log1p(((x - y) / (y + -1.0)));
	} else {
		tmp = 1.0 - log(((x + -1.0) / y));
	}
	return tmp;
}
public static double code(double x, double y) {
	double tmp;
	if (((x - y) / (1.0 - y)) <= 0.9999) {
		tmp = 1.0 - Math.log1p(((x - y) / (y + -1.0)));
	} else {
		tmp = 1.0 - Math.log(((x + -1.0) / y));
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if ((x - y) / (1.0 - y)) <= 0.9999:
		tmp = 1.0 - math.log1p(((x - y) / (y + -1.0)))
	else:
		tmp = 1.0 - math.log(((x + -1.0) / y))
	return tmp
function code(x, y)
	tmp = 0.0
	if (Float64(Float64(x - y) / Float64(1.0 - y)) <= 0.9999)
		tmp = Float64(1.0 - log1p(Float64(Float64(x - y) / Float64(y + -1.0))));
	else
		tmp = Float64(1.0 - log(Float64(Float64(x + -1.0) / y)));
	end
	return tmp
end
code[x_, y_] := If[LessEqual[N[(N[(x - y), $MachinePrecision] / N[(1.0 - y), $MachinePrecision]), $MachinePrecision], 0.9999], N[(1.0 - N[Log[1 + N[(N[(x - y), $MachinePrecision] / N[(y + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(1.0 - N[Log[N[(N[(x + -1.0), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{x - y}{1 - y} \leq 0.9999:\\
\;\;\;\;1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)\\

\mathbf{else}:\\
\;\;\;\;1 - \log \left(\frac{x + -1}{y}\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y)) < 0.99990000000000001

    1. Initial program 99.9%

      \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      2. accelerator-lowering-log1p.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      3. distribute-neg-frac2N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
      4. /-lowering-/.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
      5. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
      6. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 + \left(\mathsf{neg}\left(y\right)\right)\right)\right)\right)\right)\right)\right) \]
      7. +-commutativeN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(\left(\mathsf{neg}\left(y\right)\right) + 1\right)\right)\right)\right)\right)\right) \]
      8. distribute-neg-inN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(y\right)\right)\right)\right) + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
      9. remove-double-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
      10. metadata-evalN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
      11. +-lowering-+.f6499.9%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
    4. Applied egg-rr99.9%

      \[\leadsto 1 - \color{blue}{\mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]

    if 0.99990000000000001 < (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y))

    1. Initial program 5.1%

      \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in y around inf

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\color{blue}{\left(-1 \cdot \frac{1 + -1 \cdot x}{y}\right)}\right)\right) \]
    4. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\mathsf{neg}\left(\frac{1 + -1 \cdot x}{y}\right)\right)\right)\right) \]
      2. distribute-frac-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{\mathsf{neg}\left(\left(1 + -1 \cdot x\right)\right)}{y}\right)\right)\right) \]
      3. +-commutativeN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{\mathsf{neg}\left(\left(-1 \cdot x + 1\right)\right)}{y}\right)\right)\right) \]
      4. distribute-neg-inN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{\left(\mathsf{neg}\left(-1 \cdot x\right)\right) + \left(\mathsf{neg}\left(1\right)\right)}{y}\right)\right)\right) \]
      5. mul-1-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right) + \left(\mathsf{neg}\left(1\right)\right)}{y}\right)\right)\right) \]
      6. remove-double-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x + \left(\mathsf{neg}\left(1\right)\right)}{y}\right)\right)\right) \]
      7. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x - 1}{y}\right)\right)\right) \]
      8. /-lowering-/.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(\left(x - 1\right), y\right)\right)\right) \]
      9. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(\left(x + \left(\mathsf{neg}\left(1\right)\right)\right), y\right)\right)\right) \]
      10. metadata-evalN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(\left(x + -1\right), y\right)\right)\right) \]
      11. +-commutativeN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(\left(-1 + x\right), y\right)\right)\right) \]
      12. +-lowering-+.f6499.9%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(\mathsf{+.f64}\left(-1, x\right), y\right)\right)\right) \]
    5. Simplified99.9%

      \[\leadsto 1 - \log \color{blue}{\left(\frac{-1 + x}{y}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x - y}{1 - y} \leq 0.9999:\\ \;\;\;\;1 - \mathsf{log1p}\left(\frac{x - y}{y + -1}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{x + -1}{y}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 98.0% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := 1 - \log \left(\frac{x + -1}{y}\right)\\ \mathbf{if}\;y \leq -1:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y \leq 1:\\ \;\;\;\;1 - \mathsf{log1p}\left(0 - x\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (- 1.0 (log (/ (+ x -1.0) y)))))
   (if (<= y -1.0) t_0 (if (<= y 1.0) (- 1.0 (log1p (- 0.0 x))) t_0))))
double code(double x, double y) {
	double t_0 = 1.0 - log(((x + -1.0) / y));
	double tmp;
	if (y <= -1.0) {
		tmp = t_0;
	} else if (y <= 1.0) {
		tmp = 1.0 - log1p((0.0 - x));
	} else {
		tmp = t_0;
	}
	return tmp;
}
public static double code(double x, double y) {
	double t_0 = 1.0 - Math.log(((x + -1.0) / y));
	double tmp;
	if (y <= -1.0) {
		tmp = t_0;
	} else if (y <= 1.0) {
		tmp = 1.0 - Math.log1p((0.0 - x));
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x, y):
	t_0 = 1.0 - math.log(((x + -1.0) / y))
	tmp = 0
	if y <= -1.0:
		tmp = t_0
	elif y <= 1.0:
		tmp = 1.0 - math.log1p((0.0 - x))
	else:
		tmp = t_0
	return tmp
function code(x, y)
	t_0 = Float64(1.0 - log(Float64(Float64(x + -1.0) / y)))
	tmp = 0.0
	if (y <= -1.0)
		tmp = t_0;
	elseif (y <= 1.0)
		tmp = Float64(1.0 - log1p(Float64(0.0 - x)));
	else
		tmp = t_0;
	end
	return tmp
end
code[x_, y_] := Block[{t$95$0 = N[(1.0 - N[Log[N[(N[(x + -1.0), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[y, -1.0], t$95$0, If[LessEqual[y, 1.0], N[(1.0 - N[Log[1 + N[(0.0 - x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], t$95$0]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := 1 - \log \left(\frac{x + -1}{y}\right)\\
\mathbf{if}\;y \leq -1:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;y \leq 1:\\
\;\;\;\;1 - \mathsf{log1p}\left(0 - x\right)\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


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

    1. Initial program 26.5%

      \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in y around inf

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\color{blue}{\left(-1 \cdot \frac{1 + -1 \cdot x}{y}\right)}\right)\right) \]
    4. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\mathsf{neg}\left(\frac{1 + -1 \cdot x}{y}\right)\right)\right)\right) \]
      2. distribute-frac-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{\mathsf{neg}\left(\left(1 + -1 \cdot x\right)\right)}{y}\right)\right)\right) \]
      3. +-commutativeN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{\mathsf{neg}\left(\left(-1 \cdot x + 1\right)\right)}{y}\right)\right)\right) \]
      4. distribute-neg-inN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{\left(\mathsf{neg}\left(-1 \cdot x\right)\right) + \left(\mathsf{neg}\left(1\right)\right)}{y}\right)\right)\right) \]
      5. mul-1-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right) + \left(\mathsf{neg}\left(1\right)\right)}{y}\right)\right)\right) \]
      6. remove-double-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x + \left(\mathsf{neg}\left(1\right)\right)}{y}\right)\right)\right) \]
      7. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x - 1}{y}\right)\right)\right) \]
      8. /-lowering-/.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(\left(x - 1\right), y\right)\right)\right) \]
      9. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(\left(x + \left(\mathsf{neg}\left(1\right)\right)\right), y\right)\right)\right) \]
      10. metadata-evalN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(\left(x + -1\right), y\right)\right)\right) \]
      11. +-commutativeN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(\left(-1 + x\right), y\right)\right)\right) \]
      12. +-lowering-+.f6499.4%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(\mathsf{+.f64}\left(-1, x\right), y\right)\right)\right) \]
    5. Simplified99.4%

      \[\leadsto 1 - \log \color{blue}{\left(\frac{-1 + x}{y}\right)} \]

    if -1 < y < 1

    1. Initial program 99.9%

      \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      2. accelerator-lowering-log1p.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      3. distribute-neg-frac2N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
      4. /-lowering-/.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
      5. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
      6. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 + \left(\mathsf{neg}\left(y\right)\right)\right)\right)\right)\right)\right)\right) \]
      7. +-commutativeN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(\left(\mathsf{neg}\left(y\right)\right) + 1\right)\right)\right)\right)\right)\right) \]
      8. distribute-neg-inN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(y\right)\right)\right)\right) + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
      9. remove-double-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
      10. metadata-evalN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
      11. +-lowering-+.f64100.0%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
    4. Applied egg-rr100.0%

      \[\leadsto 1 - \color{blue}{\mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
    5. Taylor expanded in y around 0

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\color{blue}{\left(-1 \cdot x\right)}\right)\right) \]
    6. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right) \]
      2. neg-sub0N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(0 - x\right)\right)\right) \]
      3. --lowering--.f6497.9%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{\_.f64}\left(0, x\right)\right)\right) \]
    7. Simplified97.9%

      \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{0 - x}\right) \]
    8. Step-by-step derivation
      1. sub0-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right) \]
      2. neg-lowering-neg.f6497.9%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{neg.f64}\left(x\right)\right)\right) \]
    9. Applied egg-rr97.9%

      \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{-x}\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -1:\\ \;\;\;\;1 - \log \left(\frac{x + -1}{y}\right)\\ \mathbf{elif}\;y \leq 1:\\ \;\;\;\;1 - \mathsf{log1p}\left(0 - x\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{x + -1}{y}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 88.2% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -580:\\ \;\;\;\;1 - \log \left(\frac{-1}{y}\right)\\ \mathbf{elif}\;y \leq 1:\\ \;\;\;\;1 - \mathsf{log1p}\left(0 - x\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= y -580.0)
   (- 1.0 (log (/ -1.0 y)))
   (if (<= y 1.0) (- 1.0 (log1p (- 0.0 x))) (- 1.0 (log (/ x y))))))
double code(double x, double y) {
	double tmp;
	if (y <= -580.0) {
		tmp = 1.0 - log((-1.0 / y));
	} else if (y <= 1.0) {
		tmp = 1.0 - log1p((0.0 - x));
	} else {
		tmp = 1.0 - log((x / y));
	}
	return tmp;
}
public static double code(double x, double y) {
	double tmp;
	if (y <= -580.0) {
		tmp = 1.0 - Math.log((-1.0 / y));
	} else if (y <= 1.0) {
		tmp = 1.0 - Math.log1p((0.0 - x));
	} else {
		tmp = 1.0 - Math.log((x / y));
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if y <= -580.0:
		tmp = 1.0 - math.log((-1.0 / y))
	elif y <= 1.0:
		tmp = 1.0 - math.log1p((0.0 - x))
	else:
		tmp = 1.0 - math.log((x / y))
	return tmp
function code(x, y)
	tmp = 0.0
	if (y <= -580.0)
		tmp = Float64(1.0 - log(Float64(-1.0 / y)));
	elseif (y <= 1.0)
		tmp = Float64(1.0 - log1p(Float64(0.0 - x)));
	else
		tmp = Float64(1.0 - log(Float64(x / y)));
	end
	return tmp
end
code[x_, y_] := If[LessEqual[y, -580.0], N[(1.0 - N[Log[N[(-1.0 / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[y, 1.0], N[(1.0 - N[Log[1 + N[(0.0 - x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(1.0 - N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -580:\\
\;\;\;\;1 - \log \left(\frac{-1}{y}\right)\\

\mathbf{elif}\;y \leq 1:\\
\;\;\;\;1 - \mathsf{log1p}\left(0 - x\right)\\

\mathbf{else}:\\
\;\;\;\;1 - \log \left(\frac{x}{y}\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y < -580

    1. Initial program 22.8%

      \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 + \frac{y}{1 - y}\right)}\right) \]
    4. Step-by-step derivation
      1. accelerator-lowering-log1p.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{y}{1 - y}\right)\right)\right) \]
      2. /-lowering-/.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(y, \left(1 - y\right)\right)\right)\right) \]
      3. --lowering--.f644.3%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(y, \mathsf{\_.f64}\left(1, y\right)\right)\right)\right) \]
    5. Simplified4.3%

      \[\leadsto 1 - \color{blue}{\mathsf{log1p}\left(\frac{y}{1 - y}\right)} \]
    6. Taylor expanded in y around -inf

      \[\leadsto \color{blue}{1 - \log \left(\frac{-1}{y}\right)} \]
    7. Step-by-step derivation
      1. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(\frac{-1}{y}\right)}\right) \]
      2. metadata-evalN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \log \left(\frac{\mathsf{neg}\left(1\right)}{y}\right)\right) \]
      3. distribute-neg-fracN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \log \left(\mathsf{neg}\left(\frac{1}{y}\right)\right)\right) \]
      4. log-lowering-log.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\mathsf{neg}\left(\frac{1}{y}\right)\right)\right)\right) \]
      5. distribute-neg-fracN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{\mathsf{neg}\left(1\right)}{y}\right)\right)\right) \]
      6. metadata-evalN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{-1}{y}\right)\right)\right) \]
      7. /-lowering-/.f6468.8%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(-1, y\right)\right)\right) \]
    8. Simplified68.8%

      \[\leadsto \color{blue}{1 - \log \left(\frac{-1}{y}\right)} \]

    if -580 < y < 1

    1. Initial program 99.9%

      \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      2. accelerator-lowering-log1p.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      3. distribute-neg-frac2N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
      4. /-lowering-/.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
      5. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
      6. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 + \left(\mathsf{neg}\left(y\right)\right)\right)\right)\right)\right)\right)\right) \]
      7. +-commutativeN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(\left(\mathsf{neg}\left(y\right)\right) + 1\right)\right)\right)\right)\right)\right) \]
      8. distribute-neg-inN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(y\right)\right)\right)\right) + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
      9. remove-double-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
      10. metadata-evalN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
      11. +-lowering-+.f64100.0%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
    4. Applied egg-rr100.0%

      \[\leadsto 1 - \color{blue}{\mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
    5. Taylor expanded in y around 0

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\color{blue}{\left(-1 \cdot x\right)}\right)\right) \]
    6. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right) \]
      2. neg-sub0N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(0 - x\right)\right)\right) \]
      3. --lowering--.f6497.9%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{\_.f64}\left(0, x\right)\right)\right) \]
    7. Simplified97.9%

      \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{0 - x}\right) \]
    8. Step-by-step derivation
      1. sub0-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right) \]
      2. neg-lowering-neg.f6497.9%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{neg.f64}\left(x\right)\right)\right) \]
    9. Applied egg-rr97.9%

      \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{-x}\right) \]

    if 1 < y

    1. Initial program 40.7%

      \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\color{blue}{\left(-1 \cdot \frac{x}{1 - y}\right)}\right)\right) \]
    4. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\mathsf{neg}\left(\frac{x}{1 - y}\right)\right)\right)\right) \]
      2. distribute-neg-frac2N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{x}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
      3. /-lowering-/.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
      4. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \left(\mathsf{neg}\left(\left(1 + \left(\mathsf{neg}\left(y\right)\right)\right)\right)\right)\right)\right)\right) \]
      5. mul-1-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \left(\mathsf{neg}\left(\left(1 + -1 \cdot y\right)\right)\right)\right)\right)\right) \]
      6. +-commutativeN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \left(\mathsf{neg}\left(\left(-1 \cdot y + 1\right)\right)\right)\right)\right)\right) \]
      7. distribute-neg-inN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \left(\left(\mathsf{neg}\left(-1 \cdot y\right)\right) + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
      8. mul-1-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \left(\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(y\right)\right)\right)\right) + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
      9. remove-double-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \left(y + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
      10. metadata-evalN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \left(y + -1\right)\right)\right)\right) \]
      11. +-lowering-+.f6491.3%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(x, \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
    5. Simplified91.3%

      \[\leadsto 1 - \log \color{blue}{\left(\frac{x}{y + -1}\right)} \]
    6. Taylor expanded in y around inf

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\color{blue}{\left(\frac{x}{y}\right)}\right)\right) \]
    7. Step-by-step derivation
      1. /-lowering-/.f6491.3%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(x, y\right)\right)\right) \]
    8. Simplified91.3%

      \[\leadsto 1 - \log \color{blue}{\left(\frac{x}{y}\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification88.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -580:\\ \;\;\;\;1 - \log \left(\frac{-1}{y}\right)\\ \mathbf{elif}\;y \leq 1:\\ \;\;\;\;1 - \mathsf{log1p}\left(0 - x\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 78.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -28:\\ \;\;\;\;1 - \log \left(\frac{-1}{y}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \mathsf{log1p}\left(0 - x\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= y -28.0) (- 1.0 (log (/ -1.0 y))) (- 1.0 (log1p (- 0.0 x)))))
double code(double x, double y) {
	double tmp;
	if (y <= -28.0) {
		tmp = 1.0 - log((-1.0 / y));
	} else {
		tmp = 1.0 - log1p((0.0 - x));
	}
	return tmp;
}
public static double code(double x, double y) {
	double tmp;
	if (y <= -28.0) {
		tmp = 1.0 - Math.log((-1.0 / y));
	} else {
		tmp = 1.0 - Math.log1p((0.0 - x));
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if y <= -28.0:
		tmp = 1.0 - math.log((-1.0 / y))
	else:
		tmp = 1.0 - math.log1p((0.0 - x))
	return tmp
function code(x, y)
	tmp = 0.0
	if (y <= -28.0)
		tmp = Float64(1.0 - log(Float64(-1.0 / y)));
	else
		tmp = Float64(1.0 - log1p(Float64(0.0 - x)));
	end
	return tmp
end
code[x_, y_] := If[LessEqual[y, -28.0], N[(1.0 - N[Log[N[(-1.0 / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(1.0 - N[Log[1 + N[(0.0 - x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -28:\\
\;\;\;\;1 - \log \left(\frac{-1}{y}\right)\\

\mathbf{else}:\\
\;\;\;\;1 - \mathsf{log1p}\left(0 - x\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < -28

    1. Initial program 22.8%

      \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 + \frac{y}{1 - y}\right)}\right) \]
    4. Step-by-step derivation
      1. accelerator-lowering-log1p.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{y}{1 - y}\right)\right)\right) \]
      2. /-lowering-/.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(y, \left(1 - y\right)\right)\right)\right) \]
      3. --lowering--.f644.3%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(y, \mathsf{\_.f64}\left(1, y\right)\right)\right)\right) \]
    5. Simplified4.3%

      \[\leadsto 1 - \color{blue}{\mathsf{log1p}\left(\frac{y}{1 - y}\right)} \]
    6. Taylor expanded in y around -inf

      \[\leadsto \color{blue}{1 - \log \left(\frac{-1}{y}\right)} \]
    7. Step-by-step derivation
      1. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(\frac{-1}{y}\right)}\right) \]
      2. metadata-evalN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \log \left(\frac{\mathsf{neg}\left(1\right)}{y}\right)\right) \]
      3. distribute-neg-fracN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \log \left(\mathsf{neg}\left(\frac{1}{y}\right)\right)\right) \]
      4. log-lowering-log.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\mathsf{neg}\left(\frac{1}{y}\right)\right)\right)\right) \]
      5. distribute-neg-fracN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{\mathsf{neg}\left(1\right)}{y}\right)\right)\right) \]
      6. metadata-evalN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\left(\frac{-1}{y}\right)\right)\right) \]
      7. /-lowering-/.f6468.8%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log.f64}\left(\mathsf{/.f64}\left(-1, y\right)\right)\right) \]
    8. Simplified68.8%

      \[\leadsto \color{blue}{1 - \log \left(\frac{-1}{y}\right)} \]

    if -28 < y

    1. Initial program 92.9%

      \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      2. accelerator-lowering-log1p.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
      3. distribute-neg-frac2N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
      4. /-lowering-/.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
      5. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
      6. sub-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 + \left(\mathsf{neg}\left(y\right)\right)\right)\right)\right)\right)\right)\right) \]
      7. +-commutativeN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(\left(\mathsf{neg}\left(y\right)\right) + 1\right)\right)\right)\right)\right)\right) \]
      8. distribute-neg-inN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(y\right)\right)\right)\right) + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
      9. remove-double-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
      10. metadata-evalN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
      11. +-lowering-+.f6492.9%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
    4. Applied egg-rr92.9%

      \[\leadsto 1 - \color{blue}{\mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
    5. Taylor expanded in y around 0

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\color{blue}{\left(-1 \cdot x\right)}\right)\right) \]
    6. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right) \]
      2. neg-sub0N/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(0 - x\right)\right)\right) \]
      3. --lowering--.f6486.2%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{\_.f64}\left(0, x\right)\right)\right) \]
    7. Simplified86.2%

      \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{0 - x}\right) \]
    8. Step-by-step derivation
      1. sub0-negN/A

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right) \]
      2. neg-lowering-neg.f6486.2%

        \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{neg.f64}\left(x\right)\right)\right) \]
    9. Applied egg-rr86.2%

      \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{-x}\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification80.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -28:\\ \;\;\;\;1 - \log \left(\frac{-1}{y}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \mathsf{log1p}\left(0 - x\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 62.7% accurate, 1.1× speedup?

\[\begin{array}{l} \\ 1 - \mathsf{log1p}\left(0 - x\right) \end{array} \]
(FPCore (x y) :precision binary64 (- 1.0 (log1p (- 0.0 x))))
double code(double x, double y) {
	return 1.0 - log1p((0.0 - x));
}
public static double code(double x, double y) {
	return 1.0 - Math.log1p((0.0 - x));
}
def code(x, y):
	return 1.0 - math.log1p((0.0 - x))
function code(x, y)
	return Float64(1.0 - log1p(Float64(0.0 - x)))
end
code[x_, y_] := N[(1.0 - N[Log[1 + N[(0.0 - x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
1 - \mathsf{log1p}\left(0 - x\right)
\end{array}
Derivation
  1. Initial program 71.0%

    \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. sub-negN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
    2. accelerator-lowering-log1p.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
    3. distribute-neg-frac2N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
    4. /-lowering-/.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
    5. --lowering--.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
    6. sub-negN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 + \left(\mathsf{neg}\left(y\right)\right)\right)\right)\right)\right)\right)\right) \]
    7. +-commutativeN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(\left(\mathsf{neg}\left(y\right)\right) + 1\right)\right)\right)\right)\right)\right) \]
    8. distribute-neg-inN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(y\right)\right)\right)\right) + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
    9. remove-double-negN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
    10. metadata-evalN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
    11. +-lowering-+.f6471.0%

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
  4. Applied egg-rr71.0%

    \[\leadsto 1 - \color{blue}{\mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
  5. Taylor expanded in y around 0

    \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\color{blue}{\left(-1 \cdot x\right)}\right)\right) \]
  6. Step-by-step derivation
    1. mul-1-negN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right) \]
    2. neg-sub0N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(0 - x\right)\right)\right) \]
    3. --lowering--.f6463.4%

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{\_.f64}\left(0, x\right)\right)\right) \]
  7. Simplified63.4%

    \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{0 - x}\right) \]
  8. Step-by-step derivation
    1. sub0-negN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right) \]
    2. neg-lowering-neg.f6463.4%

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{neg.f64}\left(x\right)\right)\right) \]
  9. Applied egg-rr63.4%

    \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{-x}\right) \]
  10. Final simplification63.4%

    \[\leadsto 1 - \mathsf{log1p}\left(0 - x\right) \]
  11. Add Preprocessing

Alternative 8: 43.4% accurate, 10.1× speedup?

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

\\
1 + \frac{1}{\frac{-1 - y \cdot -0.5}{y}}
\end{array}
Derivation
  1. Initial program 71.0%

    \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0

    \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 + \frac{y}{1 - y}\right)}\right) \]
  4. Step-by-step derivation
    1. accelerator-lowering-log1p.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{y}{1 - y}\right)\right)\right) \]
    2. /-lowering-/.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(y, \left(1 - y\right)\right)\right)\right) \]
    3. --lowering--.f6439.9%

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(y, \mathsf{\_.f64}\left(1, y\right)\right)\right)\right) \]
  5. Simplified39.9%

    \[\leadsto 1 - \color{blue}{\mathsf{log1p}\left(\frac{y}{1 - y}\right)} \]
  6. Taylor expanded in y around 0

    \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\left(y \cdot \left(1 + \frac{1}{2} \cdot y\right)\right)}\right) \]
  7. Step-by-step derivation
    1. *-lowering-*.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{*.f64}\left(y, \color{blue}{\left(1 + \frac{1}{2} \cdot y\right)}\right)\right) \]
    2. +-lowering-+.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{*.f64}\left(y, \mathsf{+.f64}\left(1, \color{blue}{\left(\frac{1}{2} \cdot y\right)}\right)\right)\right) \]
    3. *-commutativeN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{*.f64}\left(y, \mathsf{+.f64}\left(1, \left(y \cdot \color{blue}{\frac{1}{2}}\right)\right)\right)\right) \]
    4. *-lowering-*.f6438.3%

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{*.f64}\left(y, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(y, \color{blue}{\frac{1}{2}}\right)\right)\right)\right) \]
  8. Simplified38.3%

    \[\leadsto 1 - \color{blue}{y \cdot \left(1 + y \cdot 0.5\right)} \]
  9. Step-by-step derivation
    1. distribute-rgt-inN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \left(1 \cdot y + \color{blue}{\left(y \cdot \frac{1}{2}\right) \cdot y}\right)\right) \]
    2. *-lft-identityN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \left(y + \color{blue}{\left(y \cdot \frac{1}{2}\right)} \cdot y\right)\right) \]
    3. flip-+N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \left(\frac{y \cdot y - \left(\left(y \cdot \frac{1}{2}\right) \cdot y\right) \cdot \left(\left(y \cdot \frac{1}{2}\right) \cdot y\right)}{\color{blue}{y - \left(y \cdot \frac{1}{2}\right) \cdot y}}\right)\right) \]
    4. clear-numN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \left(\frac{1}{\color{blue}{\frac{y - \left(y \cdot \frac{1}{2}\right) \cdot y}{y \cdot y - \left(\left(y \cdot \frac{1}{2}\right) \cdot y\right) \cdot \left(\left(y \cdot \frac{1}{2}\right) \cdot y\right)}}}\right)\right) \]
    5. /-lowering-/.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(1, \color{blue}{\left(\frac{y - \left(y \cdot \frac{1}{2}\right) \cdot y}{y \cdot y - \left(\left(y \cdot \frac{1}{2}\right) \cdot y\right) \cdot \left(\left(y \cdot \frac{1}{2}\right) \cdot y\right)}\right)}\right)\right) \]
    6. /-lowering-/.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\left(y - \left(y \cdot \frac{1}{2}\right) \cdot y\right), \color{blue}{\left(y \cdot y - \left(\left(y \cdot \frac{1}{2}\right) \cdot y\right) \cdot \left(\left(y \cdot \frac{1}{2}\right) \cdot y\right)\right)}\right)\right)\right) \]
    7. --lowering--.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{\_.f64}\left(y, \left(\left(y \cdot \frac{1}{2}\right) \cdot y\right)\right), \left(\color{blue}{y \cdot y} - \left(\left(y \cdot \frac{1}{2}\right) \cdot y\right) \cdot \left(\left(y \cdot \frac{1}{2}\right) \cdot y\right)\right)\right)\right)\right) \]
    8. *-commutativeN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{\_.f64}\left(y, \left(y \cdot \left(y \cdot \frac{1}{2}\right)\right)\right), \left(y \cdot \color{blue}{y} - \left(\left(y \cdot \frac{1}{2}\right) \cdot y\right) \cdot \left(\left(y \cdot \frac{1}{2}\right) \cdot y\right)\right)\right)\right)\right) \]
    9. *-lowering-*.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{\_.f64}\left(y, \mathsf{*.f64}\left(y, \left(y \cdot \frac{1}{2}\right)\right)\right), \left(y \cdot \color{blue}{y} - \left(\left(y \cdot \frac{1}{2}\right) \cdot y\right) \cdot \left(\left(y \cdot \frac{1}{2}\right) \cdot y\right)\right)\right)\right)\right) \]
    10. *-lowering-*.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{\_.f64}\left(y, \mathsf{*.f64}\left(y, \mathsf{*.f64}\left(y, \frac{1}{2}\right)\right)\right), \left(y \cdot y - \left(\left(y \cdot \frac{1}{2}\right) \cdot y\right) \cdot \left(\left(y \cdot \frac{1}{2}\right) \cdot y\right)\right)\right)\right)\right) \]
    11. --lowering--.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{\_.f64}\left(y, \mathsf{*.f64}\left(y, \mathsf{*.f64}\left(y, \frac{1}{2}\right)\right)\right), \mathsf{\_.f64}\left(\left(y \cdot y\right), \color{blue}{\left(\left(\left(y \cdot \frac{1}{2}\right) \cdot y\right) \cdot \left(\left(y \cdot \frac{1}{2}\right) \cdot y\right)\right)}\right)\right)\right)\right) \]
    12. *-lowering-*.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{\_.f64}\left(y, \mathsf{*.f64}\left(y, \mathsf{*.f64}\left(y, \frac{1}{2}\right)\right)\right), \mathsf{\_.f64}\left(\mathsf{*.f64}\left(y, y\right), \left(\color{blue}{\left(\left(y \cdot \frac{1}{2}\right) \cdot y\right)} \cdot \left(\left(y \cdot \frac{1}{2}\right) \cdot y\right)\right)\right)\right)\right)\right) \]
    13. *-lowering-*.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{\_.f64}\left(y, \mathsf{*.f64}\left(y, \mathsf{*.f64}\left(y, \frac{1}{2}\right)\right)\right), \mathsf{\_.f64}\left(\mathsf{*.f64}\left(y, y\right), \mathsf{*.f64}\left(\left(\left(y \cdot \frac{1}{2}\right) \cdot y\right), \color{blue}{\left(\left(y \cdot \frac{1}{2}\right) \cdot y\right)}\right)\right)\right)\right)\right) \]
    14. *-commutativeN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{\_.f64}\left(y, \mathsf{*.f64}\left(y, \mathsf{*.f64}\left(y, \frac{1}{2}\right)\right)\right), \mathsf{\_.f64}\left(\mathsf{*.f64}\left(y, y\right), \mathsf{*.f64}\left(\left(y \cdot \left(y \cdot \frac{1}{2}\right)\right), \left(\color{blue}{\left(y \cdot \frac{1}{2}\right)} \cdot y\right)\right)\right)\right)\right)\right) \]
    15. *-lowering-*.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{\_.f64}\left(y, \mathsf{*.f64}\left(y, \mathsf{*.f64}\left(y, \frac{1}{2}\right)\right)\right), \mathsf{\_.f64}\left(\mathsf{*.f64}\left(y, y\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(y, \left(y \cdot \frac{1}{2}\right)\right), \left(\color{blue}{\left(y \cdot \frac{1}{2}\right)} \cdot y\right)\right)\right)\right)\right)\right) \]
    16. *-lowering-*.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{\_.f64}\left(y, \mathsf{*.f64}\left(y, \mathsf{*.f64}\left(y, \frac{1}{2}\right)\right)\right), \mathsf{\_.f64}\left(\mathsf{*.f64}\left(y, y\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(y, \mathsf{*.f64}\left(y, \frac{1}{2}\right)\right), \left(\left(y \cdot \color{blue}{\frac{1}{2}}\right) \cdot y\right)\right)\right)\right)\right)\right) \]
    17. *-commutativeN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{\_.f64}\left(y, \mathsf{*.f64}\left(y, \mathsf{*.f64}\left(y, \frac{1}{2}\right)\right)\right), \mathsf{\_.f64}\left(\mathsf{*.f64}\left(y, y\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(y, \mathsf{*.f64}\left(y, \frac{1}{2}\right)\right), \left(y \cdot \color{blue}{\left(y \cdot \frac{1}{2}\right)}\right)\right)\right)\right)\right)\right) \]
    18. *-lowering-*.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{\_.f64}\left(y, \mathsf{*.f64}\left(y, \mathsf{*.f64}\left(y, \frac{1}{2}\right)\right)\right), \mathsf{\_.f64}\left(\mathsf{*.f64}\left(y, y\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(y, \mathsf{*.f64}\left(y, \frac{1}{2}\right)\right), \mathsf{*.f64}\left(y, \color{blue}{\left(y \cdot \frac{1}{2}\right)}\right)\right)\right)\right)\right)\right) \]
    19. *-lowering-*.f6438.1%

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{\_.f64}\left(y, \mathsf{*.f64}\left(y, \mathsf{*.f64}\left(y, \frac{1}{2}\right)\right)\right), \mathsf{\_.f64}\left(\mathsf{*.f64}\left(y, y\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(y, \mathsf{*.f64}\left(y, \frac{1}{2}\right)\right), \mathsf{*.f64}\left(y, \mathsf{*.f64}\left(y, \color{blue}{\frac{1}{2}}\right)\right)\right)\right)\right)\right)\right) \]
  10. Applied egg-rr38.1%

    \[\leadsto 1 - \color{blue}{\frac{1}{\frac{y - y \cdot \left(y \cdot 0.5\right)}{y \cdot y - \left(y \cdot \left(y \cdot 0.5\right)\right) \cdot \left(y \cdot \left(y \cdot 0.5\right)\right)}}} \]
  11. Taylor expanded in y around 0

    \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(1, \color{blue}{\left(\frac{1 + \frac{-1}{2} \cdot y}{y}\right)}\right)\right) \]
  12. Step-by-step derivation
    1. /-lowering-/.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\left(1 + \frac{-1}{2} \cdot y\right), \color{blue}{y}\right)\right)\right) \]
    2. +-lowering-+.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{+.f64}\left(1, \left(\frac{-1}{2} \cdot y\right)\right), y\right)\right)\right) \]
    3. *-lowering-*.f6442.5%

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\frac{-1}{2}, y\right)\right), y\right)\right)\right) \]
  13. Simplified42.5%

    \[\leadsto 1 - \frac{1}{\color{blue}{\frac{1 + -0.5 \cdot y}{y}}} \]
  14. Final simplification42.5%

    \[\leadsto 1 + \frac{1}{\frac{-1 - y \cdot -0.5}{y}} \]
  15. Add Preprocessing

Alternative 9: 42.8% accurate, 37.0× speedup?

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

\\
x + 1
\end{array}
Derivation
  1. Initial program 71.0%

    \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. sub-negN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \log \left(1 + \left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
    2. accelerator-lowering-log1p.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(\frac{x - y}{1 - y}\right)\right)\right)\right) \]
    3. distribute-neg-frac2N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{x - y}{\mathsf{neg}\left(\left(1 - y\right)\right)}\right)\right)\right) \]
    4. /-lowering-/.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\left(x - y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
    5. --lowering--.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 - y\right)\right)\right)\right)\right)\right) \]
    6. sub-negN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(1 + \left(\mathsf{neg}\left(y\right)\right)\right)\right)\right)\right)\right)\right) \]
    7. +-commutativeN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\mathsf{neg}\left(\left(\left(\mathsf{neg}\left(y\right)\right) + 1\right)\right)\right)\right)\right)\right) \]
    8. distribute-neg-inN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(y\right)\right)\right)\right) + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
    9. remove-double-negN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + \left(\mathsf{neg}\left(1\right)\right)\right)\right)\right)\right) \]
    10. metadata-evalN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \left(y + -1\right)\right)\right)\right) \]
    11. +-lowering-+.f6471.0%

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(\mathsf{\_.f64}\left(x, y\right), \mathsf{+.f64}\left(y, -1\right)\right)\right)\right) \]
  4. Applied egg-rr71.0%

    \[\leadsto 1 - \color{blue}{\mathsf{log1p}\left(\frac{x - y}{y + -1}\right)} \]
  5. Taylor expanded in y around 0

    \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\color{blue}{\left(-1 \cdot x\right)}\right)\right) \]
  6. Step-by-step derivation
    1. mul-1-negN/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right) \]
    2. neg-sub0N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(0 - x\right)\right)\right) \]
    3. --lowering--.f6463.4%

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{\_.f64}\left(0, x\right)\right)\right) \]
  7. Simplified63.4%

    \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{0 - x}\right) \]
  8. Taylor expanded in x around 0

    \[\leadsto \color{blue}{1 + x} \]
  9. Step-by-step derivation
    1. +-lowering-+.f6442.0%

      \[\leadsto \mathsf{+.f64}\left(1, \color{blue}{x}\right) \]
  10. Simplified42.0%

    \[\leadsto \color{blue}{1 + x} \]
  11. Final simplification42.0%

    \[\leadsto x + 1 \]
  12. Add Preprocessing

Alternative 10: 42.6% accurate, 111.0× speedup?

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

\\
1
\end{array}
Derivation
  1. Initial program 71.0%

    \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0

    \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\log \left(1 + \frac{y}{1 - y}\right)}\right) \]
  4. Step-by-step derivation
    1. accelerator-lowering-log1p.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\left(\frac{y}{1 - y}\right)\right)\right) \]
    2. /-lowering-/.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(y, \left(1 - y\right)\right)\right)\right) \]
    3. --lowering--.f6439.9%

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{log1p.f64}\left(\mathsf{/.f64}\left(y, \mathsf{\_.f64}\left(1, y\right)\right)\right)\right) \]
  5. Simplified39.9%

    \[\leadsto 1 - \color{blue}{\mathsf{log1p}\left(\frac{y}{1 - y}\right)} \]
  6. Taylor expanded in y around 0

    \[\leadsto \color{blue}{1} \]
  7. Step-by-step derivation
    1. Simplified41.7%

      \[\leadsto \color{blue}{1} \]
    2. Add Preprocessing

    Developer Target 1: 99.8% accurate, 0.5× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := 1 - \log \left(\frac{x}{y \cdot y} - \left(\frac{1}{y} - \frac{x}{y}\right)\right)\\ \mathbf{if}\;y < -81284752.61947241:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y < 3.0094271212461764 \cdot 10^{+25}:\\ \;\;\;\;\log \left(\frac{e^{1}}{1 - \frac{x - y}{1 - y}}\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
    (FPCore (x y)
     :precision binary64
     (let* ((t_0 (- 1.0 (log (- (/ x (* y y)) (- (/ 1.0 y) (/ x y)))))))
       (if (< y -81284752.61947241)
         t_0
         (if (< y 3.0094271212461764e+25)
           (log (/ (exp 1.0) (- 1.0 (/ (- x y) (- 1.0 y)))))
           t_0))))
    double code(double x, double y) {
    	double t_0 = 1.0 - log(((x / (y * y)) - ((1.0 / y) - (x / y))));
    	double tmp;
    	if (y < -81284752.61947241) {
    		tmp = t_0;
    	} else if (y < 3.0094271212461764e+25) {
    		tmp = log((exp(1.0) / (1.0 - ((x - y) / (1.0 - y)))));
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    real(8) function code(x, y)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        real(8) :: t_0
        real(8) :: tmp
        t_0 = 1.0d0 - log(((x / (y * y)) - ((1.0d0 / y) - (x / y))))
        if (y < (-81284752.61947241d0)) then
            tmp = t_0
        else if (y < 3.0094271212461764d+25) then
            tmp = log((exp(1.0d0) / (1.0d0 - ((x - y) / (1.0d0 - y)))))
        else
            tmp = t_0
        end if
        code = tmp
    end function
    
    public static double code(double x, double y) {
    	double t_0 = 1.0 - Math.log(((x / (y * y)) - ((1.0 / y) - (x / y))));
    	double tmp;
    	if (y < -81284752.61947241) {
    		tmp = t_0;
    	} else if (y < 3.0094271212461764e+25) {
    		tmp = Math.log((Math.exp(1.0) / (1.0 - ((x - y) / (1.0 - y)))));
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    def code(x, y):
    	t_0 = 1.0 - math.log(((x / (y * y)) - ((1.0 / y) - (x / y))))
    	tmp = 0
    	if y < -81284752.61947241:
    		tmp = t_0
    	elif y < 3.0094271212461764e+25:
    		tmp = math.log((math.exp(1.0) / (1.0 - ((x - y) / (1.0 - y)))))
    	else:
    		tmp = t_0
    	return tmp
    
    function code(x, y)
    	t_0 = Float64(1.0 - log(Float64(Float64(x / Float64(y * y)) - Float64(Float64(1.0 / y) - Float64(x / y)))))
    	tmp = 0.0
    	if (y < -81284752.61947241)
    		tmp = t_0;
    	elseif (y < 3.0094271212461764e+25)
    		tmp = log(Float64(exp(1.0) / Float64(1.0 - Float64(Float64(x - y) / Float64(1.0 - y)))));
    	else
    		tmp = t_0;
    	end
    	return tmp
    end
    
    function tmp_2 = code(x, y)
    	t_0 = 1.0 - log(((x / (y * y)) - ((1.0 / y) - (x / y))));
    	tmp = 0.0;
    	if (y < -81284752.61947241)
    		tmp = t_0;
    	elseif (y < 3.0094271212461764e+25)
    		tmp = log((exp(1.0) / (1.0 - ((x - y) / (1.0 - y)))));
    	else
    		tmp = t_0;
    	end
    	tmp_2 = tmp;
    end
    
    code[x_, y_] := Block[{t$95$0 = N[(1.0 - N[Log[N[(N[(x / N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(N[(1.0 / y), $MachinePrecision] - N[(x / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[Less[y, -81284752.61947241], t$95$0, If[Less[y, 3.0094271212461764e+25], N[Log[N[(N[Exp[1.0], $MachinePrecision] / N[(1.0 - N[(N[(x - y), $MachinePrecision] / N[(1.0 - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], t$95$0]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := 1 - \log \left(\frac{x}{y \cdot y} - \left(\frac{1}{y} - \frac{x}{y}\right)\right)\\
    \mathbf{if}\;y < -81284752.61947241:\\
    \;\;\;\;t\_0\\
    
    \mathbf{elif}\;y < 3.0094271212461764 \cdot 10^{+25}:\\
    \;\;\;\;\log \left(\frac{e^{1}}{1 - \frac{x - y}{1 - y}}\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;t\_0\\
    
    
    \end{array}
    \end{array}
    

    Reproduce

    ?
    herbie shell --seed 2024185 
    (FPCore (x y)
      :name "Numeric.SpecFunctions:invIncompleteGamma from math-functions-0.1.5.2, B"
      :precision binary64
    
      :alt
      (! :herbie-platform default (if (< y -8128475261947241/100000000) (- 1 (log (- (/ x (* y y)) (- (/ 1 y) (/ x y))))) (if (< y 30094271212461764000000000) (log (/ (exp 1) (- 1 (/ (- x y) (- 1 y))))) (- 1 (log (- (/ x (* y y)) (- (/ 1 y) (/ x y))))))))
    
      (- 1.0 (log (- 1.0 (/ (- x y) (- 1.0 y))))))