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

Percentage Accurate: 71.8% → 99.9%
Time: 8.0s
Alternatives: 13
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))));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x, y)
use fmin_fmax_functions
    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 13 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: 71.8% 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))));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x, y)
use fmin_fmax_functions
    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, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := 1 - \log \left(1 - \frac{x - y}{1 - y}\right)\\ \mathbf{if}\;t\_0 \leq 2:\\ \;\;\;\;t\_0\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{\left(-1 + \frac{\left(x - \frac{\left(1 - \frac{x - 1}{y}\right) - x}{y}\right) - 1}{y}\right) + x}{y}\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (- 1.0 (log (- 1.0 (/ (- x y) (- 1.0 y)))))))
   (if (<= t_0 2.0)
     t_0
     (-
      1.0
      (log
       (/
        (+ (+ -1.0 (/ (- (- x (/ (- (- 1.0 (/ (- x 1.0) y)) x) y)) 1.0) y)) x)
        y))))))
double code(double x, double y) {
	double t_0 = 1.0 - log((1.0 - ((x - y) / (1.0 - y))));
	double tmp;
	if (t_0 <= 2.0) {
		tmp = t_0;
	} else {
		tmp = 1.0 - log((((-1.0 + (((x - (((1.0 - ((x - 1.0) / y)) - x) / y)) - 1.0) / y)) + x) / y));
	}
	return tmp;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x, y)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    real(8) :: tmp
    t_0 = 1.0d0 - log((1.0d0 - ((x - y) / (1.0d0 - y))))
    if (t_0 <= 2.0d0) then
        tmp = t_0
    else
        tmp = 1.0d0 - log(((((-1.0d0) + (((x - (((1.0d0 - ((x - 1.0d0) / y)) - x) / y)) - 1.0d0) / y)) + x) / y))
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double t_0 = 1.0 - Math.log((1.0 - ((x - y) / (1.0 - y))));
	double tmp;
	if (t_0 <= 2.0) {
		tmp = t_0;
	} else {
		tmp = 1.0 - Math.log((((-1.0 + (((x - (((1.0 - ((x - 1.0) / y)) - x) / y)) - 1.0) / y)) + x) / y));
	}
	return tmp;
}
def code(x, y):
	t_0 = 1.0 - math.log((1.0 - ((x - y) / (1.0 - y))))
	tmp = 0
	if t_0 <= 2.0:
		tmp = t_0
	else:
		tmp = 1.0 - math.log((((-1.0 + (((x - (((1.0 - ((x - 1.0) / y)) - x) / y)) - 1.0) / y)) + x) / y))
	return tmp
function code(x, y)
	t_0 = Float64(1.0 - log(Float64(1.0 - Float64(Float64(x - y) / Float64(1.0 - y)))))
	tmp = 0.0
	if (t_0 <= 2.0)
		tmp = t_0;
	else
		tmp = Float64(1.0 - log(Float64(Float64(Float64(-1.0 + Float64(Float64(Float64(x - Float64(Float64(Float64(1.0 - Float64(Float64(x - 1.0) / y)) - x) / y)) - 1.0) / y)) + x) / y)));
	end
	return tmp
end
function tmp_2 = code(x, y)
	t_0 = 1.0 - log((1.0 - ((x - y) / (1.0 - y))));
	tmp = 0.0;
	if (t_0 <= 2.0)
		tmp = t_0;
	else
		tmp = 1.0 - log((((-1.0 + (((x - (((1.0 - ((x - 1.0) / y)) - x) / y)) - 1.0) / y)) + x) / y));
	end
	tmp_2 = tmp;
end
code[x_, y_] := Block[{t$95$0 = N[(1.0 - N[Log[N[(1.0 - N[(N[(x - y), $MachinePrecision] / N[(1.0 - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 2.0], t$95$0, N[(1.0 - N[Log[N[(N[(N[(-1.0 + N[(N[(N[(x - N[(N[(N[(1.0 - N[(N[(x - 1.0), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision] - x), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision] - 1.0), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision] + x), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := 1 - \log \left(1 - \frac{x - y}{1 - y}\right)\\
\mathbf{if}\;t\_0 \leq 2:\\
\;\;\;\;t\_0\\

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


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

    1. Initial program 100.0%

      \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
    2. Add Preprocessing

    if 2 < (-.f64 #s(literal 1 binary64) (log.f64 (-.f64 #s(literal 1 binary64) (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y)))))

    1. Initial program 7.0%

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

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

        \[\leadsto 1 - \log \color{blue}{\left(\mathsf{neg}\left(\frac{\left(1 + -1 \cdot \frac{\left(x + -1 \cdot \frac{1 + \left(-1 \cdot x + -1 \cdot \frac{x - 1}{y}\right)}{y}\right) - 1}{y}\right) - x}{y}\right)\right)} \]
      2. distribute-neg-frac2N/A

        \[\leadsto 1 - \log \color{blue}{\left(\frac{\left(1 + -1 \cdot \frac{\left(x + -1 \cdot \frac{1 + \left(-1 \cdot x + -1 \cdot \frac{x - 1}{y}\right)}{y}\right) - 1}{y}\right) - x}{\mathsf{neg}\left(y\right)}\right)} \]
      3. lower-/.f64N/A

        \[\leadsto 1 - \log \color{blue}{\left(\frac{\left(1 + -1 \cdot \frac{\left(x + -1 \cdot \frac{1 + \left(-1 \cdot x + -1 \cdot \frac{x - 1}{y}\right)}{y}\right) - 1}{y}\right) - x}{\mathsf{neg}\left(y\right)}\right)} \]
    5. Applied rewrites100.0%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;1 - \log \left(1 - \frac{x - y}{1 - y}\right) \leq 2:\\ \;\;\;\;1 - \log \left(1 - \frac{x - y}{1 - y}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{\left(-1 + \frac{\left(x - \frac{\left(1 - \frac{x - 1}{y}\right) - x}{y}\right) - 1}{y}\right) + x}{y}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 98.9% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := 1 - \log \left(1 - \frac{x - y}{1 - y}\right)\\ \mathbf{if}\;t\_0 \leq -5:\\ \;\;\;\;1 - \log \left(\frac{x}{-1 + y}\right)\\ \mathbf{elif}\;t\_0 \leq 2:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(-0.5, y, -1\right), y, 1\right) - \mathsf{log1p}\left(-x\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{-1 + x}{y}\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (- 1.0 (log (- 1.0 (/ (- x y) (- 1.0 y)))))))
   (if (<= t_0 -5.0)
     (- 1.0 (log (/ x (+ -1.0 y))))
     (if (<= t_0 2.0)
       (- (fma (fma -0.5 y -1.0) y 1.0) (log1p (- x)))
       (- 1.0 (log (/ (+ -1.0 x) y)))))))
double code(double x, double y) {
	double t_0 = 1.0 - log((1.0 - ((x - y) / (1.0 - y))));
	double tmp;
	if (t_0 <= -5.0) {
		tmp = 1.0 - log((x / (-1.0 + y)));
	} else if (t_0 <= 2.0) {
		tmp = fma(fma(-0.5, y, -1.0), y, 1.0) - log1p(-x);
	} else {
		tmp = 1.0 - log(((-1.0 + x) / y));
	}
	return tmp;
}
function code(x, y)
	t_0 = Float64(1.0 - log(Float64(1.0 - Float64(Float64(x - y) / Float64(1.0 - y)))))
	tmp = 0.0
	if (t_0 <= -5.0)
		tmp = Float64(1.0 - log(Float64(x / Float64(-1.0 + y))));
	elseif (t_0 <= 2.0)
		tmp = Float64(fma(fma(-0.5, y, -1.0), y, 1.0) - log1p(Float64(-x)));
	else
		tmp = Float64(1.0 - log(Float64(Float64(-1.0 + x) / y)));
	end
	return tmp
end
code[x_, y_] := Block[{t$95$0 = N[(1.0 - N[Log[N[(1.0 - N[(N[(x - y), $MachinePrecision] / N[(1.0 - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -5.0], N[(1.0 - N[Log[N[(x / N[(-1.0 + y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$0, 2.0], N[(N[(N[(-0.5 * y + -1.0), $MachinePrecision] * y + 1.0), $MachinePrecision] - N[Log[1 + (-x)], $MachinePrecision]), $MachinePrecision], N[(1.0 - N[Log[N[(N[(-1.0 + x), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := 1 - \log \left(1 - \frac{x - y}{1 - y}\right)\\
\mathbf{if}\;t\_0 \leq -5:\\
\;\;\;\;1 - \log \left(\frac{x}{-1 + y}\right)\\

\mathbf{elif}\;t\_0 \leq 2:\\
\;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(-0.5, y, -1\right), y, 1\right) - \mathsf{log1p}\left(-x\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (-.f64 #s(literal 1 binary64) (log.f64 (-.f64 #s(literal 1 binary64) (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y))))) < -5

    1. Initial program 100.0%

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

      \[\leadsto 1 - \log \color{blue}{\left(-1 \cdot \frac{x}{1 - y}\right)} \]
    4. Step-by-step derivation
      1. associate-*r/N/A

        \[\leadsto 1 - \log \color{blue}{\left(\frac{-1 \cdot x}{1 - y}\right)} \]
      2. lower-/.f64N/A

        \[\leadsto 1 - \log \color{blue}{\left(\frac{-1 \cdot x}{1 - y}\right)} \]
      3. mul-1-negN/A

        \[\leadsto 1 - \log \left(\frac{\color{blue}{\mathsf{neg}\left(x\right)}}{1 - y}\right) \]
      4. lower-neg.f64N/A

        \[\leadsto 1 - \log \left(\frac{\color{blue}{-x}}{1 - y}\right) \]
      5. lower--.f6498.4

        \[\leadsto 1 - \log \left(\frac{-x}{\color{blue}{1 - y}}\right) \]
    5. Applied rewrites98.4%

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

    if -5 < (-.f64 #s(literal 1 binary64) (log.f64 (-.f64 #s(literal 1 binary64) (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y))))) < 2

    1. Initial program 100.0%

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

      \[\leadsto \color{blue}{\left(1 + y \cdot \left(\frac{-1}{2} \cdot \left(y \cdot \left(-1 \cdot \frac{{\left(1 + -1 \cdot x\right)}^{2}}{{\left(1 - x\right)}^{2}} + 2 \cdot \frac{1 + -1 \cdot x}{1 - x}\right)\right) - \left(-1 \cdot \frac{x}{1 - x} + \frac{1}{1 - x}\right)\right)\right) - \log \left(1 - x\right)} \]
    4. Applied rewrites99.6%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\left(-0.5 \cdot y\right) \cdot \frac{\mathsf{fma}\left(1 - x, 2, \frac{-{\left(1 - x\right)}^{2}}{1 - x}\right)}{1 - x} - \frac{1 - x}{1 - x}, y, 1 - \mathsf{log1p}\left(-x\right)\right)} \]
    5. Applied rewrites99.6%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(-0.5, y, -1\right), y, 1\right) - \mathsf{log1p}\left(-x\right)} \]

    if 2 < (-.f64 #s(literal 1 binary64) (log.f64 (-.f64 #s(literal 1 binary64) (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y)))))

    1. Initial program 7.0%

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

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

        \[\leadsto 1 - \log \color{blue}{\left(\mathsf{neg}\left(\frac{1 + -1 \cdot x}{y}\right)\right)} \]
      2. distribute-neg-fracN/A

        \[\leadsto 1 - \log \color{blue}{\left(\frac{\mathsf{neg}\left(\left(1 + -1 \cdot x\right)\right)}{y}\right)} \]
      3. lower-/.f64N/A

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

        \[\leadsto 1 - \log \left(\frac{\color{blue}{\left(\mathsf{neg}\left(1\right)\right) + \left(\mathsf{neg}\left(-1 \cdot x\right)\right)}}{y}\right) \]
      5. metadata-evalN/A

        \[\leadsto 1 - \log \left(\frac{\color{blue}{-1} + \left(\mathsf{neg}\left(-1 \cdot x\right)\right)}{y}\right) \]
      6. mul-1-negN/A

        \[\leadsto 1 - \log \left(\frac{-1 + \left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right)\right)}{y}\right) \]
      7. remove-double-negN/A

        \[\leadsto 1 - \log \left(\frac{-1 + \color{blue}{x}}{y}\right) \]
      8. lower-+.f6499.0

        \[\leadsto 1 - \log \left(\frac{\color{blue}{-1 + x}}{y}\right) \]
    5. Applied rewrites99.0%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;1 - \log \left(1 - \frac{x - y}{1 - y}\right) \leq -5:\\ \;\;\;\;1 - \log \left(\frac{x}{-1 + y}\right)\\ \mathbf{elif}\;1 - \log \left(1 - \frac{x - y}{1 - y}\right) \leq 2:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(-0.5, y, -1\right), y, 1\right) - \mathsf{log1p}\left(-x\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{-1 + x}{y}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 99.9% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := 1 - \log \left(1 - \frac{x - y}{1 - y}\right)\\ \mathbf{if}\;t\_0 \leq 2:\\ \;\;\;\;t\_0\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{\left(-1 + \frac{\left(x - \frac{1 - x}{y}\right) - 1}{y}\right) + x}{y}\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (- 1.0 (log (- 1.0 (/ (- x y) (- 1.0 y)))))))
   (if (<= t_0 2.0)
     t_0
     (- 1.0 (log (/ (+ (+ -1.0 (/ (- (- x (/ (- 1.0 x) y)) 1.0) y)) x) y))))))
double code(double x, double y) {
	double t_0 = 1.0 - log((1.0 - ((x - y) / (1.0 - y))));
	double tmp;
	if (t_0 <= 2.0) {
		tmp = t_0;
	} else {
		tmp = 1.0 - log((((-1.0 + (((x - ((1.0 - x) / y)) - 1.0) / y)) + x) / y));
	}
	return tmp;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x, y)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    real(8) :: tmp
    t_0 = 1.0d0 - log((1.0d0 - ((x - y) / (1.0d0 - y))))
    if (t_0 <= 2.0d0) then
        tmp = t_0
    else
        tmp = 1.0d0 - log(((((-1.0d0) + (((x - ((1.0d0 - x) / y)) - 1.0d0) / y)) + x) / y))
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double t_0 = 1.0 - Math.log((1.0 - ((x - y) / (1.0 - y))));
	double tmp;
	if (t_0 <= 2.0) {
		tmp = t_0;
	} else {
		tmp = 1.0 - Math.log((((-1.0 + (((x - ((1.0 - x) / y)) - 1.0) / y)) + x) / y));
	}
	return tmp;
}
def code(x, y):
	t_0 = 1.0 - math.log((1.0 - ((x - y) / (1.0 - y))))
	tmp = 0
	if t_0 <= 2.0:
		tmp = t_0
	else:
		tmp = 1.0 - math.log((((-1.0 + (((x - ((1.0 - x) / y)) - 1.0) / y)) + x) / y))
	return tmp
function code(x, y)
	t_0 = Float64(1.0 - log(Float64(1.0 - Float64(Float64(x - y) / Float64(1.0 - y)))))
	tmp = 0.0
	if (t_0 <= 2.0)
		tmp = t_0;
	else
		tmp = Float64(1.0 - log(Float64(Float64(Float64(-1.0 + Float64(Float64(Float64(x - Float64(Float64(1.0 - x) / y)) - 1.0) / y)) + x) / y)));
	end
	return tmp
end
function tmp_2 = code(x, y)
	t_0 = 1.0 - log((1.0 - ((x - y) / (1.0 - y))));
	tmp = 0.0;
	if (t_0 <= 2.0)
		tmp = t_0;
	else
		tmp = 1.0 - log((((-1.0 + (((x - ((1.0 - x) / y)) - 1.0) / y)) + x) / y));
	end
	tmp_2 = tmp;
end
code[x_, y_] := Block[{t$95$0 = N[(1.0 - N[Log[N[(1.0 - N[(N[(x - y), $MachinePrecision] / N[(1.0 - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 2.0], t$95$0, N[(1.0 - N[Log[N[(N[(N[(-1.0 + N[(N[(N[(x - N[(N[(1.0 - x), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision] - 1.0), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision] + x), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := 1 - \log \left(1 - \frac{x - y}{1 - y}\right)\\
\mathbf{if}\;t\_0 \leq 2:\\
\;\;\;\;t\_0\\

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


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

    1. Initial program 100.0%

      \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
    2. Add Preprocessing

    if 2 < (-.f64 #s(literal 1 binary64) (log.f64 (-.f64 #s(literal 1 binary64) (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y)))))

    1. Initial program 7.0%

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

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

        \[\leadsto 1 - \log \color{blue}{\left(\mathsf{neg}\left(\frac{\left(1 + -1 \cdot \frac{\left(x + -1 \cdot \frac{1 + -1 \cdot x}{y}\right) - 1}{y}\right) - x}{y}\right)\right)} \]
      2. distribute-neg-frac2N/A

        \[\leadsto 1 - \log \color{blue}{\left(\frac{\left(1 + -1 \cdot \frac{\left(x + -1 \cdot \frac{1 + -1 \cdot x}{y}\right) - 1}{y}\right) - x}{\mathsf{neg}\left(y\right)}\right)} \]
      3. lower-/.f64N/A

        \[\leadsto 1 - \log \color{blue}{\left(\frac{\left(1 + -1 \cdot \frac{\left(x + -1 \cdot \frac{1 + -1 \cdot x}{y}\right) - 1}{y}\right) - x}{\mathsf{neg}\left(y\right)}\right)} \]
    5. Applied rewrites99.9%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;1 - \log \left(1 - \frac{x - y}{1 - y}\right) \leq 2:\\ \;\;\;\;1 - \log \left(1 - \frac{x - y}{1 - y}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{\left(-1 + \frac{\left(x - \frac{1 - x}{y}\right) - 1}{y}\right) + x}{y}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 99.8% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := 1 - \log \left(1 - \frac{x - y}{1 - y}\right)\\ \mathbf{if}\;t\_0 \leq 20:\\ \;\;\;\;t\_0\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{\left(-1 + \frac{x - 1}{y}\right) + x}{y}\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (- 1.0 (log (- 1.0 (/ (- x y) (- 1.0 y)))))))
   (if (<= t_0 20.0) t_0 (- 1.0 (log (/ (+ (+ -1.0 (/ (- x 1.0) y)) x) y))))))
double code(double x, double y) {
	double t_0 = 1.0 - log((1.0 - ((x - y) / (1.0 - y))));
	double tmp;
	if (t_0 <= 20.0) {
		tmp = t_0;
	} else {
		tmp = 1.0 - log((((-1.0 + ((x - 1.0) / y)) + x) / y));
	}
	return tmp;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x, y)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    real(8) :: tmp
    t_0 = 1.0d0 - log((1.0d0 - ((x - y) / (1.0d0 - y))))
    if (t_0 <= 20.0d0) then
        tmp = t_0
    else
        tmp = 1.0d0 - log(((((-1.0d0) + ((x - 1.0d0) / y)) + x) / y))
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double t_0 = 1.0 - Math.log((1.0 - ((x - y) / (1.0 - y))));
	double tmp;
	if (t_0 <= 20.0) {
		tmp = t_0;
	} else {
		tmp = 1.0 - Math.log((((-1.0 + ((x - 1.0) / y)) + x) / y));
	}
	return tmp;
}
def code(x, y):
	t_0 = 1.0 - math.log((1.0 - ((x - y) / (1.0 - y))))
	tmp = 0
	if t_0 <= 20.0:
		tmp = t_0
	else:
		tmp = 1.0 - math.log((((-1.0 + ((x - 1.0) / y)) + x) / y))
	return tmp
function code(x, y)
	t_0 = Float64(1.0 - log(Float64(1.0 - Float64(Float64(x - y) / Float64(1.0 - y)))))
	tmp = 0.0
	if (t_0 <= 20.0)
		tmp = t_0;
	else
		tmp = Float64(1.0 - log(Float64(Float64(Float64(-1.0 + Float64(Float64(x - 1.0) / y)) + x) / y)));
	end
	return tmp
end
function tmp_2 = code(x, y)
	t_0 = 1.0 - log((1.0 - ((x - y) / (1.0 - y))));
	tmp = 0.0;
	if (t_0 <= 20.0)
		tmp = t_0;
	else
		tmp = 1.0 - log((((-1.0 + ((x - 1.0) / y)) + x) / y));
	end
	tmp_2 = tmp;
end
code[x_, y_] := Block[{t$95$0 = N[(1.0 - N[Log[N[(1.0 - N[(N[(x - y), $MachinePrecision] / N[(1.0 - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 20.0], t$95$0, N[(1.0 - N[Log[N[(N[(N[(-1.0 + N[(N[(x - 1.0), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision] + x), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := 1 - \log \left(1 - \frac{x - y}{1 - y}\right)\\
\mathbf{if}\;t\_0 \leq 20:\\
\;\;\;\;t\_0\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 #s(literal 1 binary64) (log.f64 (-.f64 #s(literal 1 binary64) (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y))))) < 20

    1. Initial program 99.9%

      \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
    2. Add Preprocessing

    if 20 < (-.f64 #s(literal 1 binary64) (log.f64 (-.f64 #s(literal 1 binary64) (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y)))))

    1. Initial program 4.7%

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

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

        \[\leadsto 1 - \log \color{blue}{\left(\mathsf{neg}\left(\frac{\left(1 + -1 \cdot \frac{x - 1}{y}\right) - x}{y}\right)\right)} \]
      2. distribute-neg-frac2N/A

        \[\leadsto 1 - \log \color{blue}{\left(\frac{\left(1 + -1 \cdot \frac{x - 1}{y}\right) - x}{\mathsf{neg}\left(y\right)}\right)} \]
      3. associate--l+N/A

        \[\leadsto 1 - \log \left(\frac{\color{blue}{1 + \left(-1 \cdot \frac{x - 1}{y} - x\right)}}{\mathsf{neg}\left(y\right)}\right) \]
      4. *-lft-identityN/A

        \[\leadsto 1 - \log \left(\frac{1 + \left(-1 \cdot \frac{x - 1}{y} - \color{blue}{1 \cdot x}\right)}{\mathsf{neg}\left(y\right)}\right) \]
      5. metadata-evalN/A

        \[\leadsto 1 - \log \left(\frac{1 + \left(-1 \cdot \frac{x - 1}{y} - \color{blue}{\left(\mathsf{neg}\left(-1\right)\right)} \cdot x\right)}{\mathsf{neg}\left(y\right)}\right) \]
      6. fp-cancel-sign-sub-invN/A

        \[\leadsto 1 - \log \left(\frac{1 + \color{blue}{\left(-1 \cdot \frac{x - 1}{y} + -1 \cdot x\right)}}{\mathsf{neg}\left(y\right)}\right) \]
      7. +-commutativeN/A

        \[\leadsto 1 - \log \left(\frac{1 + \color{blue}{\left(-1 \cdot x + -1 \cdot \frac{x - 1}{y}\right)}}{\mathsf{neg}\left(y\right)}\right) \]
      8. lower-/.f64N/A

        \[\leadsto 1 - \log \color{blue}{\left(\frac{1 + \left(-1 \cdot x + -1 \cdot \frac{x - 1}{y}\right)}{\mathsf{neg}\left(y\right)}\right)} \]
    5. Applied rewrites100.0%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;1 - \log \left(1 - \frac{x - y}{1 - y}\right) \leq 20:\\ \;\;\;\;1 - \log \left(1 - \frac{x - y}{1 - y}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{\left(-1 + \frac{x - 1}{y}\right) + x}{y}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 99.8% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := 1 - \log \left(1 - \frac{x - y}{1 - y}\right)\\ \mathbf{if}\;t\_0 \leq 20:\\ \;\;\;\;t\_0\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{-1 + x}{y}\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (- 1.0 (log (- 1.0 (/ (- x y) (- 1.0 y)))))))
   (if (<= t_0 20.0) t_0 (- 1.0 (log (/ (+ -1.0 x) y))))))
double code(double x, double y) {
	double t_0 = 1.0 - log((1.0 - ((x - y) / (1.0 - y))));
	double tmp;
	if (t_0 <= 20.0) {
		tmp = t_0;
	} else {
		tmp = 1.0 - log(((-1.0 + x) / y));
	}
	return tmp;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x, y)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    real(8) :: tmp
    t_0 = 1.0d0 - log((1.0d0 - ((x - y) / (1.0d0 - y))))
    if (t_0 <= 20.0d0) then
        tmp = t_0
    else
        tmp = 1.0d0 - log((((-1.0d0) + x) / y))
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double t_0 = 1.0 - Math.log((1.0 - ((x - y) / (1.0 - y))));
	double tmp;
	if (t_0 <= 20.0) {
		tmp = t_0;
	} else {
		tmp = 1.0 - Math.log(((-1.0 + x) / y));
	}
	return tmp;
}
def code(x, y):
	t_0 = 1.0 - math.log((1.0 - ((x - y) / (1.0 - y))))
	tmp = 0
	if t_0 <= 20.0:
		tmp = t_0
	else:
		tmp = 1.0 - math.log(((-1.0 + x) / y))
	return tmp
function code(x, y)
	t_0 = Float64(1.0 - log(Float64(1.0 - Float64(Float64(x - y) / Float64(1.0 - y)))))
	tmp = 0.0
	if (t_0 <= 20.0)
		tmp = t_0;
	else
		tmp = Float64(1.0 - log(Float64(Float64(-1.0 + x) / y)));
	end
	return tmp
end
function tmp_2 = code(x, y)
	t_0 = 1.0 - log((1.0 - ((x - y) / (1.0 - y))));
	tmp = 0.0;
	if (t_0 <= 20.0)
		tmp = t_0;
	else
		tmp = 1.0 - log(((-1.0 + x) / y));
	end
	tmp_2 = tmp;
end
code[x_, y_] := Block[{t$95$0 = N[(1.0 - N[Log[N[(1.0 - N[(N[(x - y), $MachinePrecision] / N[(1.0 - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 20.0], t$95$0, N[(1.0 - N[Log[N[(N[(-1.0 + x), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := 1 - \log \left(1 - \frac{x - y}{1 - y}\right)\\
\mathbf{if}\;t\_0 \leq 20:\\
\;\;\;\;t\_0\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 #s(literal 1 binary64) (log.f64 (-.f64 #s(literal 1 binary64) (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y))))) < 20

    1. Initial program 99.9%

      \[1 - \log \left(1 - \frac{x - y}{1 - y}\right) \]
    2. Add Preprocessing

    if 20 < (-.f64 #s(literal 1 binary64) (log.f64 (-.f64 #s(literal 1 binary64) (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y)))))

    1. Initial program 4.7%

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

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

        \[\leadsto 1 - \log \color{blue}{\left(\mathsf{neg}\left(\frac{1 + -1 \cdot x}{y}\right)\right)} \]
      2. distribute-neg-fracN/A

        \[\leadsto 1 - \log \color{blue}{\left(\frac{\mathsf{neg}\left(\left(1 + -1 \cdot x\right)\right)}{y}\right)} \]
      3. lower-/.f64N/A

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

        \[\leadsto 1 - \log \left(\frac{\color{blue}{\left(\mathsf{neg}\left(1\right)\right) + \left(\mathsf{neg}\left(-1 \cdot x\right)\right)}}{y}\right) \]
      5. metadata-evalN/A

        \[\leadsto 1 - \log \left(\frac{\color{blue}{-1} + \left(\mathsf{neg}\left(-1 \cdot x\right)\right)}{y}\right) \]
      6. mul-1-negN/A

        \[\leadsto 1 - \log \left(\frac{-1 + \left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right)\right)}{y}\right) \]
      7. remove-double-negN/A

        \[\leadsto 1 - \log \left(\frac{-1 + \color{blue}{x}}{y}\right) \]
      8. lower-+.f6499.7

        \[\leadsto 1 - \log \left(\frac{\color{blue}{-1 + x}}{y}\right) \]
    5. Applied rewrites99.7%

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

Alternative 6: 98.3% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;1 - \log \left(1 - \frac{x - y}{1 - y}\right) \leq 2:\\ \;\;\;\;1 - \log \left(1 - \frac{x}{1 - y}\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{-1 + x}{y}\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= (- 1.0 (log (- 1.0 (/ (- x y) (- 1.0 y))))) 2.0)
   (- 1.0 (log (- 1.0 (/ x (- 1.0 y)))))
   (- 1.0 (log (/ (+ -1.0 x) y)))))
double code(double x, double y) {
	double tmp;
	if ((1.0 - log((1.0 - ((x - y) / (1.0 - y))))) <= 2.0) {
		tmp = 1.0 - log((1.0 - (x / (1.0 - y))));
	} else {
		tmp = 1.0 - log(((-1.0 + x) / y));
	}
	return tmp;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x, y)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: tmp
    if ((1.0d0 - log((1.0d0 - ((x - y) / (1.0d0 - y))))) <= 2.0d0) then
        tmp = 1.0d0 - log((1.0d0 - (x / (1.0d0 - y))))
    else
        tmp = 1.0d0 - log((((-1.0d0) + x) / y))
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double tmp;
	if ((1.0 - Math.log((1.0 - ((x - y) / (1.0 - y))))) <= 2.0) {
		tmp = 1.0 - Math.log((1.0 - (x / (1.0 - y))));
	} else {
		tmp = 1.0 - Math.log(((-1.0 + x) / y));
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if (1.0 - math.log((1.0 - ((x - y) / (1.0 - y))))) <= 2.0:
		tmp = 1.0 - math.log((1.0 - (x / (1.0 - y))))
	else:
		tmp = 1.0 - math.log(((-1.0 + x) / y))
	return tmp
function code(x, y)
	tmp = 0.0
	if (Float64(1.0 - log(Float64(1.0 - Float64(Float64(x - y) / Float64(1.0 - y))))) <= 2.0)
		tmp = Float64(1.0 - log(Float64(1.0 - Float64(x / Float64(1.0 - y)))));
	else
		tmp = Float64(1.0 - log(Float64(Float64(-1.0 + x) / y)));
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if ((1.0 - log((1.0 - ((x - y) / (1.0 - y))))) <= 2.0)
		tmp = 1.0 - log((1.0 - (x / (1.0 - y))));
	else
		tmp = 1.0 - log(((-1.0 + x) / y));
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[LessEqual[N[(1.0 - N[Log[N[(1.0 - N[(N[(x - y), $MachinePrecision] / N[(1.0 - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], 2.0], N[(1.0 - N[Log[N[(1.0 - N[(x / N[(1.0 - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(1.0 - N[Log[N[(N[(-1.0 + x), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;1 - \log \left(1 - \frac{x - y}{1 - y}\right) \leq 2:\\
\;\;\;\;1 - \log \left(1 - \frac{x}{1 - y}\right)\\

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


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

    1. Initial program 100.0%

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

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

        \[\leadsto 1 - \log \left(1 - \color{blue}{\frac{x}{1 - y}}\right) \]
      2. lower--.f6497.8

        \[\leadsto 1 - \log \left(1 - \frac{x}{\color{blue}{1 - y}}\right) \]
    5. Applied rewrites97.8%

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

    if 2 < (-.f64 #s(literal 1 binary64) (log.f64 (-.f64 #s(literal 1 binary64) (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y)))))

    1. Initial program 7.0%

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

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

        \[\leadsto 1 - \log \color{blue}{\left(\mathsf{neg}\left(\frac{1 + -1 \cdot x}{y}\right)\right)} \]
      2. distribute-neg-fracN/A

        \[\leadsto 1 - \log \color{blue}{\left(\frac{\mathsf{neg}\left(\left(1 + -1 \cdot x\right)\right)}{y}\right)} \]
      3. lower-/.f64N/A

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

        \[\leadsto 1 - \log \left(\frac{\color{blue}{\left(\mathsf{neg}\left(1\right)\right) + \left(\mathsf{neg}\left(-1 \cdot x\right)\right)}}{y}\right) \]
      5. metadata-evalN/A

        \[\leadsto 1 - \log \left(\frac{\color{blue}{-1} + \left(\mathsf{neg}\left(-1 \cdot x\right)\right)}{y}\right) \]
      6. mul-1-negN/A

        \[\leadsto 1 - \log \left(\frac{-1 + \left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right)\right)}{y}\right) \]
      7. remove-double-negN/A

        \[\leadsto 1 - \log \left(\frac{-1 + \color{blue}{x}}{y}\right) \]
      8. lower-+.f6499.0

        \[\leadsto 1 - \log \left(\frac{\color{blue}{-1 + x}}{y}\right) \]
    5. Applied rewrites99.0%

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

Alternative 7: 79.8% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;1 - \log \left(1 - \frac{x - y}{1 - y}\right) \leq 2:\\ \;\;\;\;1 - \mathsf{log1p}\left(-x\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \left(-\log \left(-y\right)\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= (- 1.0 (log (- 1.0 (/ (- x y) (- 1.0 y))))) 2.0)
   (- 1.0 (log1p (- x)))
   (- 1.0 (- (log (- y))))))
double code(double x, double y) {
	double tmp;
	if ((1.0 - log((1.0 - ((x - y) / (1.0 - y))))) <= 2.0) {
		tmp = 1.0 - log1p(-x);
	} else {
		tmp = 1.0 - -log(-y);
	}
	return tmp;
}
public static double code(double x, double y) {
	double tmp;
	if ((1.0 - Math.log((1.0 - ((x - y) / (1.0 - y))))) <= 2.0) {
		tmp = 1.0 - Math.log1p(-x);
	} else {
		tmp = 1.0 - -Math.log(-y);
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if (1.0 - math.log((1.0 - ((x - y) / (1.0 - y))))) <= 2.0:
		tmp = 1.0 - math.log1p(-x)
	else:
		tmp = 1.0 - -math.log(-y)
	return tmp
function code(x, y)
	tmp = 0.0
	if (Float64(1.0 - log(Float64(1.0 - Float64(Float64(x - y) / Float64(1.0 - y))))) <= 2.0)
		tmp = Float64(1.0 - log1p(Float64(-x)));
	else
		tmp = Float64(1.0 - Float64(-log(Float64(-y))));
	end
	return tmp
end
code[x_, y_] := If[LessEqual[N[(1.0 - N[Log[N[(1.0 - N[(N[(x - y), $MachinePrecision] / N[(1.0 - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], 2.0], N[(1.0 - N[Log[1 + (-x)], $MachinePrecision]), $MachinePrecision], N[(1.0 - (-N[Log[(-y)], $MachinePrecision])), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;1 - \log \left(1 - \frac{x - y}{1 - y}\right) \leq 2:\\
\;\;\;\;1 - \mathsf{log1p}\left(-x\right)\\

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


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

    1. Initial program 100.0%

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

      \[\leadsto 1 - \color{blue}{\log \left(1 - x\right)} \]
    4. Step-by-step derivation
      1. *-lft-identityN/A

        \[\leadsto 1 - \log \left(1 - \color{blue}{1 \cdot x}\right) \]
      2. metadata-evalN/A

        \[\leadsto 1 - \log \left(1 - \color{blue}{\left(\mathsf{neg}\left(-1\right)\right)} \cdot x\right) \]
      3. fp-cancel-sign-sub-invN/A

        \[\leadsto 1 - \log \color{blue}{\left(1 + -1 \cdot x\right)} \]
      4. lower-log1p.f64N/A

        \[\leadsto 1 - \color{blue}{\mathsf{log1p}\left(-1 \cdot x\right)} \]
      5. mul-1-negN/A

        \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{\mathsf{neg}\left(x\right)}\right) \]
      6. lower-neg.f6485.0

        \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{-x}\right) \]
    5. Applied rewrites85.0%

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

    if 2 < (-.f64 #s(literal 1 binary64) (log.f64 (-.f64 #s(literal 1 binary64) (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y)))))

    1. Initial program 7.0%

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

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

        \[\leadsto 1 - \color{blue}{\mathsf{log1p}\left(\frac{y}{1 - y}\right)} \]
      2. lower-/.f64N/A

        \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{\frac{y}{1 - y}}\right) \]
      3. lower--.f645.8

        \[\leadsto 1 - \mathsf{log1p}\left(\frac{y}{\color{blue}{1 - y}}\right) \]
    5. Applied rewrites5.8%

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

      \[\leadsto 1 - \log \left(\frac{-1}{y}\right) \]
    7. Step-by-step derivation
      1. Applied rewrites71.0%

        \[\leadsto 1 - \log \left(\frac{-1}{y}\right) \]
      2. Step-by-step derivation
        1. Applied rewrites71.0%

          \[\leadsto 1 - \left(-\log \left(-y\right)\right) \]
      3. Recombined 2 regimes into one program.
      4. Add Preprocessing

      Alternative 8: 98.7% accurate, 1.0× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -1.5:\\ \;\;\;\;1 - \log \left(\frac{-1 + x}{y}\right)\\ \mathbf{elif}\;y \leq 1:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(-0.5, y, -1\right), y, 1\right) - \mathsf{log1p}\left(-x\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\ \end{array} \end{array} \]
      (FPCore (x y)
       :precision binary64
       (if (<= y -1.5)
         (- 1.0 (log (/ (+ -1.0 x) y)))
         (if (<= y 1.0)
           (- (fma (fma -0.5 y -1.0) y 1.0) (log1p (- x)))
           (- 1.0 (log (/ x y))))))
      double code(double x, double y) {
      	double tmp;
      	if (y <= -1.5) {
      		tmp = 1.0 - log(((-1.0 + x) / y));
      	} else if (y <= 1.0) {
      		tmp = fma(fma(-0.5, y, -1.0), y, 1.0) - log1p(-x);
      	} else {
      		tmp = 1.0 - log((x / y));
      	}
      	return tmp;
      }
      
      function code(x, y)
      	tmp = 0.0
      	if (y <= -1.5)
      		tmp = Float64(1.0 - log(Float64(Float64(-1.0 + x) / y)));
      	elseif (y <= 1.0)
      		tmp = Float64(fma(fma(-0.5, y, -1.0), y, 1.0) - log1p(Float64(-x)));
      	else
      		tmp = Float64(1.0 - log(Float64(x / y)));
      	end
      	return tmp
      end
      
      code[x_, y_] := If[LessEqual[y, -1.5], N[(1.0 - N[Log[N[(N[(-1.0 + x), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[y, 1.0], N[(N[(N[(-0.5 * y + -1.0), $MachinePrecision] * y + 1.0), $MachinePrecision] - N[Log[1 + (-x)], $MachinePrecision]), $MachinePrecision], N[(1.0 - N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;y \leq -1.5:\\
      \;\;\;\;1 - \log \left(\frac{-1 + x}{y}\right)\\
      
      \mathbf{elif}\;y \leq 1:\\
      \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(-0.5, y, -1\right), y, 1\right) - \mathsf{log1p}\left(-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 < -1.5

        1. Initial program 20.3%

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

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

            \[\leadsto 1 - \log \color{blue}{\left(\mathsf{neg}\left(\frac{1 + -1 \cdot x}{y}\right)\right)} \]
          2. distribute-neg-fracN/A

            \[\leadsto 1 - \log \color{blue}{\left(\frac{\mathsf{neg}\left(\left(1 + -1 \cdot x\right)\right)}{y}\right)} \]
          3. lower-/.f64N/A

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

            \[\leadsto 1 - \log \left(\frac{\color{blue}{\left(\mathsf{neg}\left(1\right)\right) + \left(\mathsf{neg}\left(-1 \cdot x\right)\right)}}{y}\right) \]
          5. metadata-evalN/A

            \[\leadsto 1 - \log \left(\frac{\color{blue}{-1} + \left(\mathsf{neg}\left(-1 \cdot x\right)\right)}{y}\right) \]
          6. mul-1-negN/A

            \[\leadsto 1 - \log \left(\frac{-1 + \left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right)\right)}{y}\right) \]
          7. remove-double-negN/A

            \[\leadsto 1 - \log \left(\frac{-1 + \color{blue}{x}}{y}\right) \]
          8. lower-+.f6498.9

            \[\leadsto 1 - \log \left(\frac{\color{blue}{-1 + x}}{y}\right) \]
        5. Applied rewrites98.9%

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

        if -1.5 < y < 1

        1. Initial program 100.0%

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

          \[\leadsto \color{blue}{\left(1 + y \cdot \left(\frac{-1}{2} \cdot \left(y \cdot \left(-1 \cdot \frac{{\left(1 + -1 \cdot x\right)}^{2}}{{\left(1 - x\right)}^{2}} + 2 \cdot \frac{1 + -1 \cdot x}{1 - x}\right)\right) - \left(-1 \cdot \frac{x}{1 - x} + \frac{1}{1 - x}\right)\right)\right) - \log \left(1 - x\right)} \]
        4. Applied rewrites87.5%

          \[\leadsto \color{blue}{\mathsf{fma}\left(\left(-0.5 \cdot y\right) \cdot \frac{\mathsf{fma}\left(1 - x, 2, \frac{-{\left(1 - x\right)}^{2}}{1 - x}\right)}{1 - x} - \frac{1 - x}{1 - x}, y, 1 - \mathsf{log1p}\left(-x\right)\right)} \]
        5. Applied rewrites99.2%

          \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(-0.5, y, -1\right), y, 1\right) - \mathsf{log1p}\left(-x\right)} \]

        if 1 < y

        1. Initial program 49.9%

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

          \[\leadsto 1 - \log \color{blue}{\left(-1 \cdot \frac{x}{1 - y}\right)} \]
        4. Step-by-step derivation
          1. associate-*r/N/A

            \[\leadsto 1 - \log \color{blue}{\left(\frac{-1 \cdot x}{1 - y}\right)} \]
          2. lower-/.f64N/A

            \[\leadsto 1 - \log \color{blue}{\left(\frac{-1 \cdot x}{1 - y}\right)} \]
          3. mul-1-negN/A

            \[\leadsto 1 - \log \left(\frac{\color{blue}{\mathsf{neg}\left(x\right)}}{1 - y}\right) \]
          4. lower-neg.f64N/A

            \[\leadsto 1 - \log \left(\frac{\color{blue}{-x}}{1 - y}\right) \]
          5. lower--.f6499.2

            \[\leadsto 1 - \log \left(\frac{-x}{\color{blue}{1 - y}}\right) \]
        5. Applied rewrites99.2%

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

          \[\leadsto 1 - \log \left(\frac{x}{\color{blue}{y}}\right) \]
        7. Step-by-step derivation
          1. Applied rewrites96.2%

            \[\leadsto 1 - \log \left(\frac{x}{\color{blue}{y}}\right) \]
        8. Recombined 3 regimes into one program.
        9. Add Preprocessing

        Alternative 9: 89.7% accurate, 1.0× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -3.1:\\ \;\;\;\;1 - \left(-\log \left(-y\right)\right)\\ \mathbf{elif}\;y \leq 1:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(-0.5, y, -1\right), y, 1\right) - \mathsf{log1p}\left(-x\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\ \end{array} \end{array} \]
        (FPCore (x y)
         :precision binary64
         (if (<= y -3.1)
           (- 1.0 (- (log (- y))))
           (if (<= y 1.0)
             (- (fma (fma -0.5 y -1.0) y 1.0) (log1p (- x)))
             (- 1.0 (log (/ x y))))))
        double code(double x, double y) {
        	double tmp;
        	if (y <= -3.1) {
        		tmp = 1.0 - -log(-y);
        	} else if (y <= 1.0) {
        		tmp = fma(fma(-0.5, y, -1.0), y, 1.0) - log1p(-x);
        	} else {
        		tmp = 1.0 - log((x / y));
        	}
        	return tmp;
        }
        
        function code(x, y)
        	tmp = 0.0
        	if (y <= -3.1)
        		tmp = Float64(1.0 - Float64(-log(Float64(-y))));
        	elseif (y <= 1.0)
        		tmp = Float64(fma(fma(-0.5, y, -1.0), y, 1.0) - log1p(Float64(-x)));
        	else
        		tmp = Float64(1.0 - log(Float64(x / y)));
        	end
        	return tmp
        end
        
        code[x_, y_] := If[LessEqual[y, -3.1], N[(1.0 - (-N[Log[(-y)], $MachinePrecision])), $MachinePrecision], If[LessEqual[y, 1.0], N[(N[(N[(-0.5 * y + -1.0), $MachinePrecision] * y + 1.0), $MachinePrecision] - N[Log[1 + (-x)], $MachinePrecision]), $MachinePrecision], N[(1.0 - N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;y \leq -3.1:\\
        \;\;\;\;1 - \left(-\log \left(-y\right)\right)\\
        
        \mathbf{elif}\;y \leq 1:\\
        \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(-0.5, y, -1\right), y, 1\right) - \mathsf{log1p}\left(-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 < -3.10000000000000009

          1. Initial program 20.3%

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

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

              \[\leadsto 1 - \color{blue}{\mathsf{log1p}\left(\frac{y}{1 - y}\right)} \]
            2. lower-/.f64N/A

              \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{\frac{y}{1 - y}}\right) \]
            3. lower--.f645.7

              \[\leadsto 1 - \mathsf{log1p}\left(\frac{y}{\color{blue}{1 - y}}\right) \]
          5. Applied rewrites5.7%

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

            \[\leadsto 1 - \log \left(\frac{-1}{y}\right) \]
          7. Step-by-step derivation
            1. Applied rewrites76.0%

              \[\leadsto 1 - \log \left(\frac{-1}{y}\right) \]
            2. Step-by-step derivation
              1. Applied rewrites76.0%

                \[\leadsto 1 - \left(-\log \left(-y\right)\right) \]

              if -3.10000000000000009 < y < 1

              1. Initial program 100.0%

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

                \[\leadsto \color{blue}{\left(1 + y \cdot \left(\frac{-1}{2} \cdot \left(y \cdot \left(-1 \cdot \frac{{\left(1 + -1 \cdot x\right)}^{2}}{{\left(1 - x\right)}^{2}} + 2 \cdot \frac{1 + -1 \cdot x}{1 - x}\right)\right) - \left(-1 \cdot \frac{x}{1 - x} + \frac{1}{1 - x}\right)\right)\right) - \log \left(1 - x\right)} \]
              4. Applied rewrites87.5%

                \[\leadsto \color{blue}{\mathsf{fma}\left(\left(-0.5 \cdot y\right) \cdot \frac{\mathsf{fma}\left(1 - x, 2, \frac{-{\left(1 - x\right)}^{2}}{1 - x}\right)}{1 - x} - \frac{1 - x}{1 - x}, y, 1 - \mathsf{log1p}\left(-x\right)\right)} \]
              5. Applied rewrites99.2%

                \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(-0.5, y, -1\right), y, 1\right) - \mathsf{log1p}\left(-x\right)} \]

              if 1 < y

              1. Initial program 49.9%

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

                \[\leadsto 1 - \log \color{blue}{\left(-1 \cdot \frac{x}{1 - y}\right)} \]
              4. Step-by-step derivation
                1. associate-*r/N/A

                  \[\leadsto 1 - \log \color{blue}{\left(\frac{-1 \cdot x}{1 - y}\right)} \]
                2. lower-/.f64N/A

                  \[\leadsto 1 - \log \color{blue}{\left(\frac{-1 \cdot x}{1 - y}\right)} \]
                3. mul-1-negN/A

                  \[\leadsto 1 - \log \left(\frac{\color{blue}{\mathsf{neg}\left(x\right)}}{1 - y}\right) \]
                4. lower-neg.f64N/A

                  \[\leadsto 1 - \log \left(\frac{\color{blue}{-x}}{1 - y}\right) \]
                5. lower--.f6499.2

                  \[\leadsto 1 - \log \left(\frac{-x}{\color{blue}{1 - y}}\right) \]
              5. Applied rewrites99.2%

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

                \[\leadsto 1 - \log \left(\frac{x}{\color{blue}{y}}\right) \]
              7. Step-by-step derivation
                1. Applied rewrites96.2%

                  \[\leadsto 1 - \log \left(\frac{x}{\color{blue}{y}}\right) \]
              8. Recombined 3 regimes into one program.
              9. Add Preprocessing

              Alternative 10: 89.4% accurate, 1.0× speedup?

              \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -1:\\ \;\;\;\;1 - \left(-\log \left(-y\right)\right)\\ \mathbf{elif}\;y \leq 1:\\ \;\;\;\;1 - \log \left(\left(y - -1\right) \cdot \left(1 - x\right)\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\ \end{array} \end{array} \]
              (FPCore (x y)
               :precision binary64
               (if (<= y -1.0)
                 (- 1.0 (- (log (- y))))
                 (if (<= y 1.0)
                   (- 1.0 (log (* (- y -1.0) (- 1.0 x))))
                   (- 1.0 (log (/ x y))))))
              double code(double x, double y) {
              	double tmp;
              	if (y <= -1.0) {
              		tmp = 1.0 - -log(-y);
              	} else if (y <= 1.0) {
              		tmp = 1.0 - log(((y - -1.0) * (1.0 - x)));
              	} else {
              		tmp = 1.0 - log((x / y));
              	}
              	return tmp;
              }
              
              module fmin_fmax_functions
                  implicit none
                  private
                  public fmax
                  public fmin
              
                  interface fmax
                      module procedure fmax88
                      module procedure fmax44
                      module procedure fmax84
                      module procedure fmax48
                  end interface
                  interface fmin
                      module procedure fmin88
                      module procedure fmin44
                      module procedure fmin84
                      module procedure fmin48
                  end interface
              contains
                  real(8) function fmax88(x, y) result (res)
                      real(8), intent (in) :: x
                      real(8), intent (in) :: y
                      res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                  end function
                  real(4) function fmax44(x, y) result (res)
                      real(4), intent (in) :: x
                      real(4), intent (in) :: y
                      res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                  end function
                  real(8) function fmax84(x, y) result(res)
                      real(8), intent (in) :: x
                      real(4), intent (in) :: y
                      res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                  end function
                  real(8) function fmax48(x, y) result(res)
                      real(4), intent (in) :: x
                      real(8), intent (in) :: y
                      res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                  end function
                  real(8) function fmin88(x, y) result (res)
                      real(8), intent (in) :: x
                      real(8), intent (in) :: y
                      res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                  end function
                  real(4) function fmin44(x, y) result (res)
                      real(4), intent (in) :: x
                      real(4), intent (in) :: y
                      res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                  end function
                  real(8) function fmin84(x, y) result(res)
                      real(8), intent (in) :: x
                      real(4), intent (in) :: y
                      res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                  end function
                  real(8) function fmin48(x, y) result(res)
                      real(4), intent (in) :: x
                      real(8), intent (in) :: y
                      res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                  end function
              end module
              
              real(8) function code(x, y)
              use fmin_fmax_functions
                  real(8), intent (in) :: x
                  real(8), intent (in) :: y
                  real(8) :: tmp
                  if (y <= (-1.0d0)) then
                      tmp = 1.0d0 - -log(-y)
                  else if (y <= 1.0d0) then
                      tmp = 1.0d0 - log(((y - (-1.0d0)) * (1.0d0 - x)))
                  else
                      tmp = 1.0d0 - log((x / y))
                  end if
                  code = tmp
              end function
              
              public static double code(double x, double y) {
              	double tmp;
              	if (y <= -1.0) {
              		tmp = 1.0 - -Math.log(-y);
              	} else if (y <= 1.0) {
              		tmp = 1.0 - Math.log(((y - -1.0) * (1.0 - x)));
              	} else {
              		tmp = 1.0 - Math.log((x / y));
              	}
              	return tmp;
              }
              
              def code(x, y):
              	tmp = 0
              	if y <= -1.0:
              		tmp = 1.0 - -math.log(-y)
              	elif y <= 1.0:
              		tmp = 1.0 - math.log(((y - -1.0) * (1.0 - x)))
              	else:
              		tmp = 1.0 - math.log((x / y))
              	return tmp
              
              function code(x, y)
              	tmp = 0.0
              	if (y <= -1.0)
              		tmp = Float64(1.0 - Float64(-log(Float64(-y))));
              	elseif (y <= 1.0)
              		tmp = Float64(1.0 - log(Float64(Float64(y - -1.0) * Float64(1.0 - x))));
              	else
              		tmp = Float64(1.0 - log(Float64(x / y)));
              	end
              	return tmp
              end
              
              function tmp_2 = code(x, y)
              	tmp = 0.0;
              	if (y <= -1.0)
              		tmp = 1.0 - -log(-y);
              	elseif (y <= 1.0)
              		tmp = 1.0 - log(((y - -1.0) * (1.0 - x)));
              	else
              		tmp = 1.0 - log((x / y));
              	end
              	tmp_2 = tmp;
              end
              
              code[x_, y_] := If[LessEqual[y, -1.0], N[(1.0 - (-N[Log[(-y)], $MachinePrecision])), $MachinePrecision], If[LessEqual[y, 1.0], N[(1.0 - N[Log[N[(N[(y - -1.0), $MachinePrecision] * N[(1.0 - x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(1.0 - N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]]
              
              \begin{array}{l}
              
              \\
              \begin{array}{l}
              \mathbf{if}\;y \leq -1:\\
              \;\;\;\;1 - \left(-\log \left(-y\right)\right)\\
              
              \mathbf{elif}\;y \leq 1:\\
              \;\;\;\;1 - \log \left(\left(y - -1\right) \cdot \left(1 - x\right)\right)\\
              
              \mathbf{else}:\\
              \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\
              
              
              \end{array}
              \end{array}
              
              Derivation
              1. Split input into 3 regimes
              2. if y < -1

                1. Initial program 20.3%

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

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

                    \[\leadsto 1 - \color{blue}{\mathsf{log1p}\left(\frac{y}{1 - y}\right)} \]
                  2. lower-/.f64N/A

                    \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{\frac{y}{1 - y}}\right) \]
                  3. lower--.f645.7

                    \[\leadsto 1 - \mathsf{log1p}\left(\frac{y}{\color{blue}{1 - y}}\right) \]
                5. Applied rewrites5.7%

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

                  \[\leadsto 1 - \log \left(\frac{-1}{y}\right) \]
                7. Step-by-step derivation
                  1. Applied rewrites76.0%

                    \[\leadsto 1 - \log \left(\frac{-1}{y}\right) \]
                  2. Step-by-step derivation
                    1. Applied rewrites76.0%

                      \[\leadsto 1 - \left(-\log \left(-y\right)\right) \]

                    if -1 < y < 1

                    1. Initial program 100.0%

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

                      \[\leadsto 1 - \log \color{blue}{\left(\left(1 + y \cdot \left(1 + -1 \cdot x\right)\right) - x\right)} \]
                    4. Step-by-step derivation
                      1. +-commutativeN/A

                        \[\leadsto 1 - \log \left(\color{blue}{\left(y \cdot \left(1 + -1 \cdot x\right) + 1\right)} - x\right) \]
                      2. associate--l+N/A

                        \[\leadsto 1 - \log \color{blue}{\left(y \cdot \left(1 + -1 \cdot x\right) + \left(1 - x\right)\right)} \]
                      3. *-lft-identityN/A

                        \[\leadsto 1 - \log \left(y \cdot \left(1 + -1 \cdot x\right) + \left(1 - \color{blue}{1 \cdot x}\right)\right) \]
                      4. metadata-evalN/A

                        \[\leadsto 1 - \log \left(y \cdot \left(1 + -1 \cdot x\right) + \left(1 - \color{blue}{\left(\mathsf{neg}\left(-1\right)\right)} \cdot x\right)\right) \]
                      5. fp-cancel-sign-sub-invN/A

                        \[\leadsto 1 - \log \left(y \cdot \left(1 + -1 \cdot x\right) + \color{blue}{\left(1 + -1 \cdot x\right)}\right) \]
                      6. +-commutativeN/A

                        \[\leadsto 1 - \log \color{blue}{\left(\left(1 + -1 \cdot x\right) + y \cdot \left(1 + -1 \cdot x\right)\right)} \]
                      7. distribute-rgt1-inN/A

                        \[\leadsto 1 - \log \color{blue}{\left(\left(y + 1\right) \cdot \left(1 + -1 \cdot x\right)\right)} \]
                      8. lower-*.f64N/A

                        \[\leadsto 1 - \log \color{blue}{\left(\left(y + 1\right) \cdot \left(1 + -1 \cdot x\right)\right)} \]
                      9. lower-+.f64N/A

                        \[\leadsto 1 - \log \left(\color{blue}{\left(y + 1\right)} \cdot \left(1 + -1 \cdot x\right)\right) \]
                      10. fp-cancel-sign-sub-invN/A

                        \[\leadsto 1 - \log \left(\left(y + 1\right) \cdot \color{blue}{\left(1 - \left(\mathsf{neg}\left(-1\right)\right) \cdot x\right)}\right) \]
                      11. metadata-evalN/A

                        \[\leadsto 1 - \log \left(\left(y + 1\right) \cdot \left(1 - \color{blue}{1} \cdot x\right)\right) \]
                      12. *-lft-identityN/A

                        \[\leadsto 1 - \log \left(\left(y + 1\right) \cdot \left(1 - \color{blue}{x}\right)\right) \]
                      13. lower--.f6498.5

                        \[\leadsto 1 - \log \left(\left(y + 1\right) \cdot \color{blue}{\left(1 - x\right)}\right) \]
                    5. Applied rewrites98.5%

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

                    if 1 < y

                    1. Initial program 49.9%

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

                      \[\leadsto 1 - \log \color{blue}{\left(-1 \cdot \frac{x}{1 - y}\right)} \]
                    4. Step-by-step derivation
                      1. associate-*r/N/A

                        \[\leadsto 1 - \log \color{blue}{\left(\frac{-1 \cdot x}{1 - y}\right)} \]
                      2. lower-/.f64N/A

                        \[\leadsto 1 - \log \color{blue}{\left(\frac{-1 \cdot x}{1 - y}\right)} \]
                      3. mul-1-negN/A

                        \[\leadsto 1 - \log \left(\frac{\color{blue}{\mathsf{neg}\left(x\right)}}{1 - y}\right) \]
                      4. lower-neg.f64N/A

                        \[\leadsto 1 - \log \left(\frac{\color{blue}{-x}}{1 - y}\right) \]
                      5. lower--.f6499.2

                        \[\leadsto 1 - \log \left(\frac{-x}{\color{blue}{1 - y}}\right) \]
                    5. Applied rewrites99.2%

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

                      \[\leadsto 1 - \log \left(\frac{x}{\color{blue}{y}}\right) \]
                    7. Step-by-step derivation
                      1. Applied rewrites96.2%

                        \[\leadsto 1 - \log \left(\frac{x}{\color{blue}{y}}\right) \]
                    8. Recombined 3 regimes into one program.
                    9. Final simplification91.7%

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

                    Alternative 11: 88.9% accurate, 1.0× speedup?

                    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -200:\\ \;\;\;\;1 - \left(-\log \left(-y\right)\right)\\ \mathbf{elif}\;y \leq 1:\\ \;\;\;\;1 - \mathsf{log1p}\left(-x\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \log \left(\frac{x}{y}\right)\\ \end{array} \end{array} \]
                    (FPCore (x y)
                     :precision binary64
                     (if (<= y -200.0)
                       (- 1.0 (- (log (- y))))
                       (if (<= y 1.0) (- 1.0 (log1p (- x))) (- 1.0 (log (/ x y))))))
                    double code(double x, double y) {
                    	double tmp;
                    	if (y <= -200.0) {
                    		tmp = 1.0 - -log(-y);
                    	} else if (y <= 1.0) {
                    		tmp = 1.0 - log1p(-x);
                    	} else {
                    		tmp = 1.0 - log((x / y));
                    	}
                    	return tmp;
                    }
                    
                    public static double code(double x, double y) {
                    	double tmp;
                    	if (y <= -200.0) {
                    		tmp = 1.0 - -Math.log(-y);
                    	} else if (y <= 1.0) {
                    		tmp = 1.0 - Math.log1p(-x);
                    	} else {
                    		tmp = 1.0 - Math.log((x / y));
                    	}
                    	return tmp;
                    }
                    
                    def code(x, y):
                    	tmp = 0
                    	if y <= -200.0:
                    		tmp = 1.0 - -math.log(-y)
                    	elif y <= 1.0:
                    		tmp = 1.0 - math.log1p(-x)
                    	else:
                    		tmp = 1.0 - math.log((x / y))
                    	return tmp
                    
                    function code(x, y)
                    	tmp = 0.0
                    	if (y <= -200.0)
                    		tmp = Float64(1.0 - Float64(-log(Float64(-y))));
                    	elseif (y <= 1.0)
                    		tmp = Float64(1.0 - log1p(Float64(-x)));
                    	else
                    		tmp = Float64(1.0 - log(Float64(x / y)));
                    	end
                    	return tmp
                    end
                    
                    code[x_, y_] := If[LessEqual[y, -200.0], N[(1.0 - (-N[Log[(-y)], $MachinePrecision])), $MachinePrecision], If[LessEqual[y, 1.0], N[(1.0 - N[Log[1 + (-x)], $MachinePrecision]), $MachinePrecision], N[(1.0 - N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]]
                    
                    \begin{array}{l}
                    
                    \\
                    \begin{array}{l}
                    \mathbf{if}\;y \leq -200:\\
                    \;\;\;\;1 - \left(-\log \left(-y\right)\right)\\
                    
                    \mathbf{elif}\;y \leq 1:\\
                    \;\;\;\;1 - \mathsf{log1p}\left(-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 < -200

                      1. Initial program 20.3%

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

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

                          \[\leadsto 1 - \color{blue}{\mathsf{log1p}\left(\frac{y}{1 - y}\right)} \]
                        2. lower-/.f64N/A

                          \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{\frac{y}{1 - y}}\right) \]
                        3. lower--.f645.7

                          \[\leadsto 1 - \mathsf{log1p}\left(\frac{y}{\color{blue}{1 - y}}\right) \]
                      5. Applied rewrites5.7%

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

                        \[\leadsto 1 - \log \left(\frac{-1}{y}\right) \]
                      7. Step-by-step derivation
                        1. Applied rewrites76.0%

                          \[\leadsto 1 - \log \left(\frac{-1}{y}\right) \]
                        2. Step-by-step derivation
                          1. Applied rewrites76.0%

                            \[\leadsto 1 - \left(-\log \left(-y\right)\right) \]

                          if -200 < y < 1

                          1. Initial program 100.0%

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

                            \[\leadsto 1 - \color{blue}{\log \left(1 - x\right)} \]
                          4. Step-by-step derivation
                            1. *-lft-identityN/A

                              \[\leadsto 1 - \log \left(1 - \color{blue}{1 \cdot x}\right) \]
                            2. metadata-evalN/A

                              \[\leadsto 1 - \log \left(1 - \color{blue}{\left(\mathsf{neg}\left(-1\right)\right)} \cdot x\right) \]
                            3. fp-cancel-sign-sub-invN/A

                              \[\leadsto 1 - \log \color{blue}{\left(1 + -1 \cdot x\right)} \]
                            4. lower-log1p.f64N/A

                              \[\leadsto 1 - \color{blue}{\mathsf{log1p}\left(-1 \cdot x\right)} \]
                            5. mul-1-negN/A

                              \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{\mathsf{neg}\left(x\right)}\right) \]
                            6. lower-neg.f6497.2

                              \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{-x}\right) \]
                          5. Applied rewrites97.2%

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

                          if 1 < y

                          1. Initial program 49.9%

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

                            \[\leadsto 1 - \log \color{blue}{\left(-1 \cdot \frac{x}{1 - y}\right)} \]
                          4. Step-by-step derivation
                            1. associate-*r/N/A

                              \[\leadsto 1 - \log \color{blue}{\left(\frac{-1 \cdot x}{1 - y}\right)} \]
                            2. lower-/.f64N/A

                              \[\leadsto 1 - \log \color{blue}{\left(\frac{-1 \cdot x}{1 - y}\right)} \]
                            3. mul-1-negN/A

                              \[\leadsto 1 - \log \left(\frac{\color{blue}{\mathsf{neg}\left(x\right)}}{1 - y}\right) \]
                            4. lower-neg.f64N/A

                              \[\leadsto 1 - \log \left(\frac{\color{blue}{-x}}{1 - y}\right) \]
                            5. lower--.f6499.2

                              \[\leadsto 1 - \log \left(\frac{-x}{\color{blue}{1 - y}}\right) \]
                          5. Applied rewrites99.2%

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

                            \[\leadsto 1 - \log \left(\frac{x}{\color{blue}{y}}\right) \]
                          7. Step-by-step derivation
                            1. Applied rewrites96.2%

                              \[\leadsto 1 - \log \left(\frac{x}{\color{blue}{y}}\right) \]
                          8. Recombined 3 regimes into one program.
                          9. Add Preprocessing

                          Alternative 12: 62.2% accurate, 1.2× speedup?

                          \[\begin{array}{l} \\ 1 - \mathsf{log1p}\left(-x\right) \end{array} \]
                          (FPCore (x y) :precision binary64 (- 1.0 (log1p (- x))))
                          double code(double x, double y) {
                          	return 1.0 - log1p(-x);
                          }
                          
                          public static double code(double x, double y) {
                          	return 1.0 - Math.log1p(-x);
                          }
                          
                          def code(x, y):
                          	return 1.0 - math.log1p(-x)
                          
                          function code(x, y)
                          	return Float64(1.0 - log1p(Float64(-x)))
                          end
                          
                          code[x_, y_] := N[(1.0 - N[Log[1 + (-x)], $MachinePrecision]), $MachinePrecision]
                          
                          \begin{array}{l}
                          
                          \\
                          1 - \mathsf{log1p}\left(-x\right)
                          \end{array}
                          
                          Derivation
                          1. Initial program 71.3%

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

                            \[\leadsto 1 - \color{blue}{\log \left(1 - x\right)} \]
                          4. Step-by-step derivation
                            1. *-lft-identityN/A

                              \[\leadsto 1 - \log \left(1 - \color{blue}{1 \cdot x}\right) \]
                            2. metadata-evalN/A

                              \[\leadsto 1 - \log \left(1 - \color{blue}{\left(\mathsf{neg}\left(-1\right)\right)} \cdot x\right) \]
                            3. fp-cancel-sign-sub-invN/A

                              \[\leadsto 1 - \log \color{blue}{\left(1 + -1 \cdot x\right)} \]
                            4. lower-log1p.f64N/A

                              \[\leadsto 1 - \color{blue}{\mathsf{log1p}\left(-1 \cdot x\right)} \]
                            5. mul-1-negN/A

                              \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{\mathsf{neg}\left(x\right)}\right) \]
                            6. lower-neg.f6461.9

                              \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{-x}\right) \]
                          5. Applied rewrites61.9%

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

                          Alternative 13: 43.0% accurate, 20.7× speedup?

                          \[\begin{array}{l} \\ 1 - \left(-x\right) \end{array} \]
                          (FPCore (x y) :precision binary64 (- 1.0 (- x)))
                          double code(double x, double y) {
                          	return 1.0 - -x;
                          }
                          
                          module fmin_fmax_functions
                              implicit none
                              private
                              public fmax
                              public fmin
                          
                              interface fmax
                                  module procedure fmax88
                                  module procedure fmax44
                                  module procedure fmax84
                                  module procedure fmax48
                              end interface
                              interface fmin
                                  module procedure fmin88
                                  module procedure fmin44
                                  module procedure fmin84
                                  module procedure fmin48
                              end interface
                          contains
                              real(8) function fmax88(x, y) result (res)
                                  real(8), intent (in) :: x
                                  real(8), intent (in) :: y
                                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                              end function
                              real(4) function fmax44(x, y) result (res)
                                  real(4), intent (in) :: x
                                  real(4), intent (in) :: y
                                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                              end function
                              real(8) function fmax84(x, y) result(res)
                                  real(8), intent (in) :: x
                                  real(4), intent (in) :: y
                                  res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                              end function
                              real(8) function fmax48(x, y) result(res)
                                  real(4), intent (in) :: x
                                  real(8), intent (in) :: y
                                  res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                              end function
                              real(8) function fmin88(x, y) result (res)
                                  real(8), intent (in) :: x
                                  real(8), intent (in) :: y
                                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                              end function
                              real(4) function fmin44(x, y) result (res)
                                  real(4), intent (in) :: x
                                  real(4), intent (in) :: y
                                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                              end function
                              real(8) function fmin84(x, y) result(res)
                                  real(8), intent (in) :: x
                                  real(4), intent (in) :: y
                                  res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                              end function
                              real(8) function fmin48(x, y) result(res)
                                  real(4), intent (in) :: x
                                  real(8), intent (in) :: y
                                  res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                              end function
                          end module
                          
                          real(8) function code(x, y)
                          use fmin_fmax_functions
                              real(8), intent (in) :: x
                              real(8), intent (in) :: y
                              code = 1.0d0 - -x
                          end function
                          
                          public static double code(double x, double y) {
                          	return 1.0 - -x;
                          }
                          
                          def code(x, y):
                          	return 1.0 - -x
                          
                          function code(x, y)
                          	return Float64(1.0 - Float64(-x))
                          end
                          
                          function tmp = code(x, y)
                          	tmp = 1.0 - -x;
                          end
                          
                          code[x_, y_] := N[(1.0 - (-x)), $MachinePrecision]
                          
                          \begin{array}{l}
                          
                          \\
                          1 - \left(-x\right)
                          \end{array}
                          
                          Derivation
                          1. Initial program 71.3%

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

                            \[\leadsto 1 - \color{blue}{\log \left(1 - x\right)} \]
                          4. Step-by-step derivation
                            1. *-lft-identityN/A

                              \[\leadsto 1 - \log \left(1 - \color{blue}{1 \cdot x}\right) \]
                            2. metadata-evalN/A

                              \[\leadsto 1 - \log \left(1 - \color{blue}{\left(\mathsf{neg}\left(-1\right)\right)} \cdot x\right) \]
                            3. fp-cancel-sign-sub-invN/A

                              \[\leadsto 1 - \log \color{blue}{\left(1 + -1 \cdot x\right)} \]
                            4. lower-log1p.f64N/A

                              \[\leadsto 1 - \color{blue}{\mathsf{log1p}\left(-1 \cdot x\right)} \]
                            5. mul-1-negN/A

                              \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{\mathsf{neg}\left(x\right)}\right) \]
                            6. lower-neg.f6461.9

                              \[\leadsto 1 - \mathsf{log1p}\left(\color{blue}{-x}\right) \]
                          5. Applied rewrites61.9%

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

                            \[\leadsto 1 - -1 \cdot \color{blue}{x} \]
                          7. Step-by-step derivation
                            1. Applied rewrites47.3%

                              \[\leadsto 1 - \left(-x\right) \]
                            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;
                            }
                            
                            module fmin_fmax_functions
                                implicit none
                                private
                                public fmax
                                public fmin
                            
                                interface fmax
                                    module procedure fmax88
                                    module procedure fmax44
                                    module procedure fmax84
                                    module procedure fmax48
                                end interface
                                interface fmin
                                    module procedure fmin88
                                    module procedure fmin44
                                    module procedure fmin84
                                    module procedure fmin48
                                end interface
                            contains
                                real(8) function fmax88(x, y) result (res)
                                    real(8), intent (in) :: x
                                    real(8), intent (in) :: y
                                    res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                end function
                                real(4) function fmax44(x, y) result (res)
                                    real(4), intent (in) :: x
                                    real(4), intent (in) :: y
                                    res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                end function
                                real(8) function fmax84(x, y) result(res)
                                    real(8), intent (in) :: x
                                    real(4), intent (in) :: y
                                    res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                                end function
                                real(8) function fmax48(x, y) result(res)
                                    real(4), intent (in) :: x
                                    real(8), intent (in) :: y
                                    res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                                end function
                                real(8) function fmin88(x, y) result (res)
                                    real(8), intent (in) :: x
                                    real(8), intent (in) :: y
                                    res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                end function
                                real(4) function fmin44(x, y) result (res)
                                    real(4), intent (in) :: x
                                    real(4), intent (in) :: y
                                    res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                end function
                                real(8) function fmin84(x, y) result(res)
                                    real(8), intent (in) :: x
                                    real(4), intent (in) :: y
                                    res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                                end function
                                real(8) function fmin48(x, y) result(res)
                                    real(4), intent (in) :: x
                                    real(8), intent (in) :: y
                                    res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                                end function
                            end module
                            
                            real(8) function code(x, y)
                            use fmin_fmax_functions
                                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 2025008 
                            (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))))))