Logistic regression 2

Percentage Accurate: 99.1% → 99.1%
Time: 16.0s
Alternatives: 12
Speedup: 1.0×

Specification

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

\\
\log \left(1 + e^{x}\right) - x \cdot y
\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 12 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: 99.1% accurate, 1.0× speedup?

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

\\
\log \left(1 + e^{x}\right) - x \cdot y
\end{array}

Alternative 1: 99.1% accurate, 1.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.6:\\ \;\;\;\;0 - y \cdot x\\ \mathbf{else}:\\ \;\;\;\;\mathsf{log1p}\left(1 + x \cdot \left(1 + x \cdot \left(0.5 + x \cdot 0.16666666666666666\right)\right)\right) - y \cdot x\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= x -1.6)
   (- 0.0 (* y x))
   (-
    (log1p (+ 1.0 (* x (+ 1.0 (* x (+ 0.5 (* x 0.16666666666666666)))))))
    (* y x))))
double code(double x, double y) {
	double tmp;
	if (x <= -1.6) {
		tmp = 0.0 - (y * x);
	} else {
		tmp = log1p((1.0 + (x * (1.0 + (x * (0.5 + (x * 0.16666666666666666))))))) - (y * x);
	}
	return tmp;
}
public static double code(double x, double y) {
	double tmp;
	if (x <= -1.6) {
		tmp = 0.0 - (y * x);
	} else {
		tmp = Math.log1p((1.0 + (x * (1.0 + (x * (0.5 + (x * 0.16666666666666666))))))) - (y * x);
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if x <= -1.6:
		tmp = 0.0 - (y * x)
	else:
		tmp = math.log1p((1.0 + (x * (1.0 + (x * (0.5 + (x * 0.16666666666666666))))))) - (y * x)
	return tmp
function code(x, y)
	tmp = 0.0
	if (x <= -1.6)
		tmp = Float64(0.0 - Float64(y * x));
	else
		tmp = Float64(log1p(Float64(1.0 + Float64(x * Float64(1.0 + Float64(x * Float64(0.5 + Float64(x * 0.16666666666666666))))))) - Float64(y * x));
	end
	return tmp
end
code[x_, y_] := If[LessEqual[x, -1.6], N[(0.0 - N[(y * x), $MachinePrecision]), $MachinePrecision], N[(N[Log[1 + N[(1.0 + N[(x * N[(1.0 + N[(x * N[(0.5 + N[(x * 0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - N[(y * x), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.6:\\
\;\;\;\;0 - y \cdot x\\

\mathbf{else}:\\
\;\;\;\;\mathsf{log1p}\left(1 + x \cdot \left(1 + x \cdot \left(0.5 + x \cdot 0.16666666666666666\right)\right)\right) - y \cdot x\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1.6000000000000001

    1. Initial program 100.0%

      \[\log \left(1 + e^{x}\right) - x \cdot y \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
      3. exp-lowering-exp.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
      4. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf

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

        \[\leadsto \mathsf{neg}\left(x \cdot y\right) \]
      2. neg-sub0N/A

        \[\leadsto 0 - \color{blue}{x \cdot y} \]
      3. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(0, \color{blue}{\left(x \cdot y\right)}\right) \]
      4. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{\_.f64}\left(0, \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    7. Simplified100.0%

      \[\leadsto \color{blue}{0 - x \cdot y} \]
    8. Step-by-step derivation
      1. sub0-negN/A

        \[\leadsto \mathsf{neg}\left(x \cdot y\right) \]
      2. neg-lowering-neg.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\left(x \cdot y\right)\right) \]
      3. *-commutativeN/A

        \[\leadsto \mathsf{neg.f64}\left(\left(y \cdot x\right)\right) \]
      4. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{*.f64}\left(y, x\right)\right) \]
    9. Applied egg-rr100.0%

      \[\leadsto \color{blue}{-y \cdot x} \]

    if -1.6000000000000001 < x

    1. Initial program 99.4%

      \[\log \left(1 + e^{x}\right) - x \cdot y \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
      3. exp-lowering-exp.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
      4. *-lowering-*.f6499.4%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    3. Simplified99.4%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0

      \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\color{blue}{\left(1 + x \cdot \left(1 + x \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot x\right)\right)\right)}\right), \mathsf{*.f64}\left(x, y\right)\right) \]
    6. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{+.f64}\left(1, \left(x \cdot \left(1 + x \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot x\right)\right)\right)\right)\right), \mathsf{*.f64}\left(x, y\right)\right) \]
      2. *-lowering-*.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \left(1 + x \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot x\right)\right)\right)\right)\right), \mathsf{*.f64}\left(x, y\right)\right) \]
      3. +-lowering-+.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \left(x \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot x\right)\right)\right)\right)\right)\right), \mathsf{*.f64}\left(x, y\right)\right) \]
      4. *-lowering-*.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \left(\frac{1}{2} + \frac{1}{6} \cdot x\right)\right)\right)\right)\right)\right), \mathsf{*.f64}\left(x, y\right)\right) \]
      5. +-lowering-+.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{1}{6} \cdot x\right)\right)\right)\right)\right)\right)\right), \mathsf{*.f64}\left(x, y\right)\right) \]
      6. *-commutativeN/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \left(x \cdot \frac{1}{6}\right)\right)\right)\right)\right)\right)\right), \mathsf{*.f64}\left(x, y\right)\right) \]
      7. *-lowering-*.f6499.5%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(x, \frac{1}{6}\right)\right)\right)\right)\right)\right)\right), \mathsf{*.f64}\left(x, y\right)\right) \]
    7. Simplified99.5%

      \[\leadsto \mathsf{log1p}\left(\color{blue}{1 + x \cdot \left(1 + x \cdot \left(0.5 + x \cdot 0.16666666666666666\right)\right)}\right) - x \cdot y \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.6:\\ \;\;\;\;0 - y \cdot x\\ \mathbf{else}:\\ \;\;\;\;\mathsf{log1p}\left(1 + x \cdot \left(1 + x \cdot \left(0.5 + x \cdot 0.16666666666666666\right)\right)\right) - y \cdot x\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 99.2% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(0 - y, x, \mathsf{log1p}\left(e^{x}\right)\right) \end{array} \]
(FPCore (x y) :precision binary64 (fma (- 0.0 y) x (log1p (exp x))))
double code(double x, double y) {
	return fma((0.0 - y), x, log1p(exp(x)));
}
function code(x, y)
	return fma(Float64(0.0 - y), x, log1p(exp(x)))
end
code[x_, y_] := N[(N[(0.0 - y), $MachinePrecision] * x + N[Log[1 + N[Exp[x], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(0 - y, x, \mathsf{log1p}\left(e^{x}\right)\right)
\end{array}
Derivation
  1. Initial program 99.6%

    \[\log \left(1 + e^{x}\right) - x \cdot y \]
  2. Step-by-step derivation
    1. --lowering--.f64N/A

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

      \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
    3. exp-lowering-exp.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
    4. *-lowering-*.f6499.6%

      \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
  3. Simplified99.6%

    \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. sub-negN/A

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

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

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

      \[\leadsto \left(\mathsf{neg}\left(y\right)\right) \cdot x + \log \color{blue}{\left(1 + e^{x}\right)} \]
    5. accelerator-lowering-fma.f64N/A

      \[\leadsto \mathsf{fma.f64}\left(\left(\mathsf{neg}\left(y\right)\right), \color{blue}{x}, \log \left(1 + e^{x}\right)\right) \]
    6. neg-sub0N/A

      \[\leadsto \mathsf{fma.f64}\left(\left(0 - y\right), x, \log \left(1 + e^{x}\right)\right) \]
    7. --lowering--.f64N/A

      \[\leadsto \mathsf{fma.f64}\left(\mathsf{\_.f64}\left(0, y\right), x, \log \left(1 + e^{x}\right)\right) \]
    8. accelerator-lowering-log1p.f64N/A

      \[\leadsto \mathsf{fma.f64}\left(\mathsf{\_.f64}\left(0, y\right), x, \mathsf{log1p.f64}\left(\left(e^{x}\right)\right)\right) \]
    9. exp-lowering-exp.f6499.6%

      \[\leadsto \mathsf{fma.f64}\left(\mathsf{\_.f64}\left(0, y\right), x, \mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right)\right) \]
  6. Applied egg-rr99.6%

    \[\leadsto \color{blue}{\mathsf{fma}\left(0 - y, x, \mathsf{log1p}\left(e^{x}\right)\right)} \]
  7. Add Preprocessing

Alternative 3: 99.2% accurate, 1.0× speedup?

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

\\
\mathsf{log1p}\left(e^{x}\right) - y \cdot x
\end{array}
Derivation
  1. Initial program 99.6%

    \[\log \left(1 + e^{x}\right) - x \cdot y \]
  2. Step-by-step derivation
    1. --lowering--.f64N/A

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

      \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
    3. exp-lowering-exp.f64N/A

      \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
    4. *-lowering-*.f6499.6%

      \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
  3. Simplified99.6%

    \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
  4. Add Preprocessing
  5. Final simplification99.6%

    \[\leadsto \mathsf{log1p}\left(e^{x}\right) - y \cdot x \]
  6. Add Preprocessing

Alternative 4: 98.4% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -5 \cdot 10^{+15}:\\ \;\;\;\;0 - y \cdot x\\ \mathbf{else}:\\ \;\;\;\;\left(\log 2 + x \cdot 0.5\right) + x \cdot \left(x \cdot 0.125 - y\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= x -5e+15)
   (- 0.0 (* y x))
   (+ (+ (log 2.0) (* x 0.5)) (* x (- (* x 0.125) y)))))
double code(double x, double y) {
	double tmp;
	if (x <= -5e+15) {
		tmp = 0.0 - (y * x);
	} else {
		tmp = (log(2.0) + (x * 0.5)) + (x * ((x * 0.125) - y));
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: tmp
    if (x <= (-5d+15)) then
        tmp = 0.0d0 - (y * x)
    else
        tmp = (log(2.0d0) + (x * 0.5d0)) + (x * ((x * 0.125d0) - y))
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double tmp;
	if (x <= -5e+15) {
		tmp = 0.0 - (y * x);
	} else {
		tmp = (Math.log(2.0) + (x * 0.5)) + (x * ((x * 0.125) - y));
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if x <= -5e+15:
		tmp = 0.0 - (y * x)
	else:
		tmp = (math.log(2.0) + (x * 0.5)) + (x * ((x * 0.125) - y))
	return tmp
function code(x, y)
	tmp = 0.0
	if (x <= -5e+15)
		tmp = Float64(0.0 - Float64(y * x));
	else
		tmp = Float64(Float64(log(2.0) + Float64(x * 0.5)) + Float64(x * Float64(Float64(x * 0.125) - y)));
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if (x <= -5e+15)
		tmp = 0.0 - (y * x);
	else
		tmp = (log(2.0) + (x * 0.5)) + (x * ((x * 0.125) - y));
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[LessEqual[x, -5e+15], N[(0.0 - N[(y * x), $MachinePrecision]), $MachinePrecision], N[(N[(N[Log[2.0], $MachinePrecision] + N[(x * 0.5), $MachinePrecision]), $MachinePrecision] + N[(x * N[(N[(x * 0.125), $MachinePrecision] - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -5 \cdot 10^{+15}:\\
\;\;\;\;0 - y \cdot x\\

\mathbf{else}:\\
\;\;\;\;\left(\log 2 + x \cdot 0.5\right) + x \cdot \left(x \cdot 0.125 - y\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -5e15

    1. Initial program 100.0%

      \[\log \left(1 + e^{x}\right) - x \cdot y \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
      3. exp-lowering-exp.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
      4. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf

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

        \[\leadsto \mathsf{neg}\left(x \cdot y\right) \]
      2. neg-sub0N/A

        \[\leadsto 0 - \color{blue}{x \cdot y} \]
      3. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(0, \color{blue}{\left(x \cdot y\right)}\right) \]
      4. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{\_.f64}\left(0, \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    7. Simplified100.0%

      \[\leadsto \color{blue}{0 - x \cdot y} \]
    8. Step-by-step derivation
      1. sub0-negN/A

        \[\leadsto \mathsf{neg}\left(x \cdot y\right) \]
      2. neg-lowering-neg.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\left(x \cdot y\right)\right) \]
      3. *-commutativeN/A

        \[\leadsto \mathsf{neg.f64}\left(\left(y \cdot x\right)\right) \]
      4. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{*.f64}\left(y, x\right)\right) \]
    9. Applied egg-rr100.0%

      \[\leadsto \color{blue}{-y \cdot x} \]

    if -5e15 < x

    1. Initial program 99.4%

      \[\log \left(1 + e^{x}\right) - x \cdot y \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
      3. exp-lowering-exp.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
      4. *-lowering-*.f6499.4%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    3. Simplified99.4%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\log 2 + x \cdot \left(\left(\frac{1}{2} + \frac{1}{8} \cdot x\right) - y\right)} \]
    6. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\log 2, \color{blue}{\left(x \cdot \left(\left(\frac{1}{2} + \frac{1}{8} \cdot x\right) - y\right)\right)}\right) \]
      2. log-lowering-log.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \left(\color{blue}{x} \cdot \left(\left(\frac{1}{2} + \frac{1}{8} \cdot x\right) - y\right)\right)\right) \]
      3. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \color{blue}{\left(\left(\frac{1}{2} + \frac{1}{8} \cdot x\right) - y\right)}\right)\right) \]
      4. associate--l+N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \left(\frac{1}{2} + \color{blue}{\left(\frac{1}{8} \cdot x - y\right)}\right)\right)\right) \]
      5. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \color{blue}{\left(\frac{1}{8} \cdot x - y\right)}\right)\right)\right) \]
      6. --lowering--.f64N/A

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

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{\_.f64}\left(\left(x \cdot \frac{1}{8}\right), y\right)\right)\right)\right) \]
      8. *-lowering-*.f6499.5%

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(x, \frac{1}{8}\right), y\right)\right)\right)\right) \]
    7. Simplified99.5%

      \[\leadsto \color{blue}{\log 2 + x \cdot \left(0.5 + \left(x \cdot 0.125 - y\right)\right)} \]
    8. Step-by-step derivation
      1. metadata-evalN/A

        \[\leadsto \log \left(1 + 1\right) + x \cdot \left(\frac{1}{2} + \left(x \cdot \frac{1}{8} - y\right)\right) \]
      2. distribute-rgt-inN/A

        \[\leadsto \log \left(1 + 1\right) + \left(\frac{1}{2} \cdot x + \color{blue}{\left(x \cdot \frac{1}{8} - y\right) \cdot x}\right) \]
      3. associate-+r+N/A

        \[\leadsto \left(\log \left(1 + 1\right) + \frac{1}{2} \cdot x\right) + \color{blue}{\left(x \cdot \frac{1}{8} - y\right) \cdot x} \]
      4. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\left(\log \left(1 + 1\right) + \frac{1}{2} \cdot x\right), \color{blue}{\left(\left(x \cdot \frac{1}{8} - y\right) \cdot x\right)}\right) \]
      5. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{+.f64}\left(\log \left(1 + 1\right), \left(\frac{1}{2} \cdot x\right)\right), \left(\color{blue}{\left(x \cdot \frac{1}{8} - y\right)} \cdot x\right)\right) \]
      6. log-lowering-log.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{+.f64}\left(\mathsf{log.f64}\left(\left(1 + 1\right)\right), \left(\frac{1}{2} \cdot x\right)\right), \left(\left(\color{blue}{x \cdot \frac{1}{8}} - y\right) \cdot x\right)\right) \]
      7. metadata-evalN/A

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

        \[\leadsto \mathsf{+.f64}\left(\mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \left(x \cdot \frac{1}{2}\right)\right), \left(\left(x \cdot \frac{1}{8} - \color{blue}{y}\right) \cdot x\right)\right) \]
      9. *-lowering-*.f64N/A

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

        \[\leadsto \mathsf{+.f64}\left(\mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \frac{1}{2}\right)\right), \left(x \cdot \color{blue}{\left(x \cdot \frac{1}{8} - y\right)}\right)\right) \]
      11. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \frac{1}{2}\right)\right), \mathsf{*.f64}\left(x, \color{blue}{\left(x \cdot \frac{1}{8} - y\right)}\right)\right) \]
      12. --lowering--.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \frac{1}{2}\right)\right), \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\left(x \cdot \frac{1}{8}\right), \color{blue}{y}\right)\right)\right) \]
      13. *-lowering-*.f6499.5%

        \[\leadsto \mathsf{+.f64}\left(\mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \frac{1}{2}\right)\right), \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(x, \frac{1}{8}\right), y\right)\right)\right) \]
    9. Applied egg-rr99.5%

      \[\leadsto \color{blue}{\left(\log 2 + x \cdot 0.5\right) + x \cdot \left(x \cdot 0.125 - y\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -5 \cdot 10^{+15}:\\ \;\;\;\;0 - y \cdot x\\ \mathbf{else}:\\ \;\;\;\;\left(\log 2 + x \cdot 0.5\right) + x \cdot \left(x \cdot 0.125 - y\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 98.4% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -5 \cdot 10^{+15}:\\ \;\;\;\;0 - y \cdot x\\ \mathbf{else}:\\ \;\;\;\;\log 2 + x \cdot \left(0.5 + \left(x \cdot 0.125 - y\right)\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= x -5e+15)
   (- 0.0 (* y x))
   (+ (log 2.0) (* x (+ 0.5 (- (* x 0.125) y))))))
double code(double x, double y) {
	double tmp;
	if (x <= -5e+15) {
		tmp = 0.0 - (y * x);
	} else {
		tmp = log(2.0) + (x * (0.5 + ((x * 0.125) - y)));
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: tmp
    if (x <= (-5d+15)) then
        tmp = 0.0d0 - (y * x)
    else
        tmp = log(2.0d0) + (x * (0.5d0 + ((x * 0.125d0) - y)))
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double tmp;
	if (x <= -5e+15) {
		tmp = 0.0 - (y * x);
	} else {
		tmp = Math.log(2.0) + (x * (0.5 + ((x * 0.125) - y)));
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if x <= -5e+15:
		tmp = 0.0 - (y * x)
	else:
		tmp = math.log(2.0) + (x * (0.5 + ((x * 0.125) - y)))
	return tmp
function code(x, y)
	tmp = 0.0
	if (x <= -5e+15)
		tmp = Float64(0.0 - Float64(y * x));
	else
		tmp = Float64(log(2.0) + Float64(x * Float64(0.5 + Float64(Float64(x * 0.125) - y))));
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if (x <= -5e+15)
		tmp = 0.0 - (y * x);
	else
		tmp = log(2.0) + (x * (0.5 + ((x * 0.125) - y)));
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[LessEqual[x, -5e+15], N[(0.0 - N[(y * x), $MachinePrecision]), $MachinePrecision], N[(N[Log[2.0], $MachinePrecision] + N[(x * N[(0.5 + N[(N[(x * 0.125), $MachinePrecision] - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -5 \cdot 10^{+15}:\\
\;\;\;\;0 - y \cdot x\\

\mathbf{else}:\\
\;\;\;\;\log 2 + x \cdot \left(0.5 + \left(x \cdot 0.125 - y\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -5e15

    1. Initial program 100.0%

      \[\log \left(1 + e^{x}\right) - x \cdot y \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
      3. exp-lowering-exp.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
      4. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf

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

        \[\leadsto \mathsf{neg}\left(x \cdot y\right) \]
      2. neg-sub0N/A

        \[\leadsto 0 - \color{blue}{x \cdot y} \]
      3. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(0, \color{blue}{\left(x \cdot y\right)}\right) \]
      4. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{\_.f64}\left(0, \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    7. Simplified100.0%

      \[\leadsto \color{blue}{0 - x \cdot y} \]
    8. Step-by-step derivation
      1. sub0-negN/A

        \[\leadsto \mathsf{neg}\left(x \cdot y\right) \]
      2. neg-lowering-neg.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\left(x \cdot y\right)\right) \]
      3. *-commutativeN/A

        \[\leadsto \mathsf{neg.f64}\left(\left(y \cdot x\right)\right) \]
      4. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{*.f64}\left(y, x\right)\right) \]
    9. Applied egg-rr100.0%

      \[\leadsto \color{blue}{-y \cdot x} \]

    if -5e15 < x

    1. Initial program 99.4%

      \[\log \left(1 + e^{x}\right) - x \cdot y \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
      3. exp-lowering-exp.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
      4. *-lowering-*.f6499.4%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    3. Simplified99.4%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\log 2 + x \cdot \left(\left(\frac{1}{2} + \frac{1}{8} \cdot x\right) - y\right)} \]
    6. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\log 2, \color{blue}{\left(x \cdot \left(\left(\frac{1}{2} + \frac{1}{8} \cdot x\right) - y\right)\right)}\right) \]
      2. log-lowering-log.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \left(\color{blue}{x} \cdot \left(\left(\frac{1}{2} + \frac{1}{8} \cdot x\right) - y\right)\right)\right) \]
      3. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \color{blue}{\left(\left(\frac{1}{2} + \frac{1}{8} \cdot x\right) - y\right)}\right)\right) \]
      4. associate--l+N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \left(\frac{1}{2} + \color{blue}{\left(\frac{1}{8} \cdot x - y\right)}\right)\right)\right) \]
      5. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \color{blue}{\left(\frac{1}{8} \cdot x - y\right)}\right)\right)\right) \]
      6. --lowering--.f64N/A

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

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{\_.f64}\left(\left(x \cdot \frac{1}{8}\right), y\right)\right)\right)\right) \]
      8. *-lowering-*.f6499.5%

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(x, \frac{1}{8}\right), y\right)\right)\right)\right) \]
    7. Simplified99.5%

      \[\leadsto \color{blue}{\log 2 + x \cdot \left(0.5 + \left(x \cdot 0.125 - y\right)\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -5 \cdot 10^{+15}:\\ \;\;\;\;0 - y \cdot x\\ \mathbf{else}:\\ \;\;\;\;\log 2 + x \cdot \left(0.5 + \left(x \cdot 0.125 - y\right)\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 81.5% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := 0 - y \cdot x\\ \mathbf{if}\;x \leq -1.25 \cdot 10^{-98}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x \leq 280:\\ \;\;\;\;\log 2 + x \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (- 0.0 (* y x))))
   (if (<= x -1.25e-98) t_0 (if (<= x 280.0) (+ (log 2.0) (* x 0.5)) t_0))))
double code(double x, double y) {
	double t_0 = 0.0 - (y * x);
	double tmp;
	if (x <= -1.25e-98) {
		tmp = t_0;
	} else if (x <= 280.0) {
		tmp = log(2.0) + (x * 0.5);
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    real(8) :: tmp
    t_0 = 0.0d0 - (y * x)
    if (x <= (-1.25d-98)) then
        tmp = t_0
    else if (x <= 280.0d0) then
        tmp = log(2.0d0) + (x * 0.5d0)
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double t_0 = 0.0 - (y * x);
	double tmp;
	if (x <= -1.25e-98) {
		tmp = t_0;
	} else if (x <= 280.0) {
		tmp = Math.log(2.0) + (x * 0.5);
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x, y):
	t_0 = 0.0 - (y * x)
	tmp = 0
	if x <= -1.25e-98:
		tmp = t_0
	elif x <= 280.0:
		tmp = math.log(2.0) + (x * 0.5)
	else:
		tmp = t_0
	return tmp
function code(x, y)
	t_0 = Float64(0.0 - Float64(y * x))
	tmp = 0.0
	if (x <= -1.25e-98)
		tmp = t_0;
	elseif (x <= 280.0)
		tmp = Float64(log(2.0) + Float64(x * 0.5));
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x, y)
	t_0 = 0.0 - (y * x);
	tmp = 0.0;
	if (x <= -1.25e-98)
		tmp = t_0;
	elseif (x <= 280.0)
		tmp = log(2.0) + (x * 0.5);
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_, y_] := Block[{t$95$0 = N[(0.0 - N[(y * x), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[x, -1.25e-98], t$95$0, If[LessEqual[x, 280.0], N[(N[Log[2.0], $MachinePrecision] + N[(x * 0.5), $MachinePrecision]), $MachinePrecision], t$95$0]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := 0 - y \cdot x\\
\mathbf{if}\;x \leq -1.25 \cdot 10^{-98}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;x \leq 280:\\
\;\;\;\;\log 2 + x \cdot 0.5\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1.25000000000000005e-98 or 280 < x

    1. Initial program 99.1%

      \[\log \left(1 + e^{x}\right) - x \cdot y \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
      3. exp-lowering-exp.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
      4. *-lowering-*.f6499.1%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    3. Simplified99.1%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf

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

        \[\leadsto \mathsf{neg}\left(x \cdot y\right) \]
      2. neg-sub0N/A

        \[\leadsto 0 - \color{blue}{x \cdot y} \]
      3. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(0, \color{blue}{\left(x \cdot y\right)}\right) \]
      4. *-lowering-*.f6492.2%

        \[\leadsto \mathsf{\_.f64}\left(0, \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    7. Simplified92.2%

      \[\leadsto \color{blue}{0 - x \cdot y} \]
    8. Step-by-step derivation
      1. sub0-negN/A

        \[\leadsto \mathsf{neg}\left(x \cdot y\right) \]
      2. neg-lowering-neg.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\left(x \cdot y\right)\right) \]
      3. *-commutativeN/A

        \[\leadsto \mathsf{neg.f64}\left(\left(y \cdot x\right)\right) \]
      4. *-lowering-*.f6492.2%

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{*.f64}\left(y, x\right)\right) \]
    9. Applied egg-rr92.2%

      \[\leadsto \color{blue}{-y \cdot x} \]

    if -1.25000000000000005e-98 < x < 280

    1. Initial program 99.9%

      \[\log \left(1 + e^{x}\right) - x \cdot y \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
      3. exp-lowering-exp.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
      4. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
    4. Add Preprocessing
    5. Taylor expanded in y around 0

      \[\leadsto \color{blue}{\log \left(1 + e^{x}\right)} \]
    6. Step-by-step derivation
      1. accelerator-lowering-log1p.f64N/A

        \[\leadsto \mathsf{log1p.f64}\left(\left(e^{x}\right)\right) \]
      2. exp-lowering-exp.f6484.3%

        \[\leadsto \mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right) \]
    7. Simplified84.3%

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

      \[\leadsto \color{blue}{\log 2 + \frac{1}{2} \cdot x} \]
    9. Step-by-step derivation
      1. +-lowering-+.f64N/A

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

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

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \left(x \cdot \color{blue}{\frac{1}{2}}\right)\right) \]
      4. *-lowering-*.f6483.5%

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \color{blue}{\frac{1}{2}}\right)\right) \]
    10. Simplified83.5%

      \[\leadsto \color{blue}{\log 2 + x \cdot 0.5} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification87.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.25 \cdot 10^{-98}:\\ \;\;\;\;0 - y \cdot x\\ \mathbf{elif}\;x \leq 280:\\ \;\;\;\;\log 2 + x \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;0 - y \cdot x\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 81.8% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -6.8 \cdot 10^{-99}:\\ \;\;\;\;0 - y \cdot x\\ \mathbf{elif}\;x \leq 0.00016:\\ \;\;\;\;\mathsf{log1p}\left(x + 1\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(\left(0.5 - x \cdot -0.125\right) - y\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= x -6.8e-99)
   (- 0.0 (* y x))
   (if (<= x 0.00016) (log1p (+ x 1.0)) (* x (- (- 0.5 (* x -0.125)) y)))))
double code(double x, double y) {
	double tmp;
	if (x <= -6.8e-99) {
		tmp = 0.0 - (y * x);
	} else if (x <= 0.00016) {
		tmp = log1p((x + 1.0));
	} else {
		tmp = x * ((0.5 - (x * -0.125)) - y);
	}
	return tmp;
}
public static double code(double x, double y) {
	double tmp;
	if (x <= -6.8e-99) {
		tmp = 0.0 - (y * x);
	} else if (x <= 0.00016) {
		tmp = Math.log1p((x + 1.0));
	} else {
		tmp = x * ((0.5 - (x * -0.125)) - y);
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if x <= -6.8e-99:
		tmp = 0.0 - (y * x)
	elif x <= 0.00016:
		tmp = math.log1p((x + 1.0))
	else:
		tmp = x * ((0.5 - (x * -0.125)) - y)
	return tmp
function code(x, y)
	tmp = 0.0
	if (x <= -6.8e-99)
		tmp = Float64(0.0 - Float64(y * x));
	elseif (x <= 0.00016)
		tmp = log1p(Float64(x + 1.0));
	else
		tmp = Float64(x * Float64(Float64(0.5 - Float64(x * -0.125)) - y));
	end
	return tmp
end
code[x_, y_] := If[LessEqual[x, -6.8e-99], N[(0.0 - N[(y * x), $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 0.00016], N[Log[1 + N[(x + 1.0), $MachinePrecision]], $MachinePrecision], N[(x * N[(N[(0.5 - N[(x * -0.125), $MachinePrecision]), $MachinePrecision] - y), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -6.8 \cdot 10^{-99}:\\
\;\;\;\;0 - y \cdot x\\

\mathbf{elif}\;x \leq 0.00016:\\
\;\;\;\;\mathsf{log1p}\left(x + 1\right)\\

\mathbf{else}:\\
\;\;\;\;x \cdot \left(\left(0.5 - x \cdot -0.125\right) - y\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -6.80000000000000014e-99

    1. Initial program 100.0%

      \[\log \left(1 + e^{x}\right) - x \cdot y \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
      3. exp-lowering-exp.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
      4. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf

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

        \[\leadsto \mathsf{neg}\left(x \cdot y\right) \]
      2. neg-sub0N/A

        \[\leadsto 0 - \color{blue}{x \cdot y} \]
      3. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(0, \color{blue}{\left(x \cdot y\right)}\right) \]
      4. *-lowering-*.f6491.2%

        \[\leadsto \mathsf{\_.f64}\left(0, \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    7. Simplified91.2%

      \[\leadsto \color{blue}{0 - x \cdot y} \]
    8. Step-by-step derivation
      1. sub0-negN/A

        \[\leadsto \mathsf{neg}\left(x \cdot y\right) \]
      2. neg-lowering-neg.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\left(x \cdot y\right)\right) \]
      3. *-commutativeN/A

        \[\leadsto \mathsf{neg.f64}\left(\left(y \cdot x\right)\right) \]
      4. *-lowering-*.f6491.2%

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{*.f64}\left(y, x\right)\right) \]
    9. Applied egg-rr91.2%

      \[\leadsto \color{blue}{-y \cdot x} \]

    if -6.80000000000000014e-99 < x < 1.60000000000000013e-4

    1. Initial program 99.9%

      \[\log \left(1 + e^{x}\right) - x \cdot y \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
      3. exp-lowering-exp.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
      4. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
    4. Add Preprocessing
    5. Taylor expanded in y around 0

      \[\leadsto \color{blue}{\log \left(1 + e^{x}\right)} \]
    6. Step-by-step derivation
      1. accelerator-lowering-log1p.f64N/A

        \[\leadsto \mathsf{log1p.f64}\left(\left(e^{x}\right)\right) \]
      2. exp-lowering-exp.f6484.2%

        \[\leadsto \mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right) \]
    7. Simplified84.2%

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

      \[\leadsto \mathsf{log1p.f64}\left(\color{blue}{\left(1 + x\right)}\right) \]
    9. Step-by-step derivation
      1. +-lowering-+.f6483.9%

        \[\leadsto \mathsf{log1p.f64}\left(\mathsf{+.f64}\left(1, x\right)\right) \]
    10. Simplified83.9%

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

    if 1.60000000000000013e-4 < x

    1. Initial program 92.9%

      \[\log \left(1 + e^{x}\right) - x \cdot y \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
      3. exp-lowering-exp.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
      4. *-lowering-*.f6492.9%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    3. Simplified92.9%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\log 2 + x \cdot \left(\left(\frac{1}{2} + \frac{1}{8} \cdot x\right) - y\right)} \]
    6. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\log 2, \color{blue}{\left(x \cdot \left(\left(\frac{1}{2} + \frac{1}{8} \cdot x\right) - y\right)\right)}\right) \]
      2. log-lowering-log.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \left(\color{blue}{x} \cdot \left(\left(\frac{1}{2} + \frac{1}{8} \cdot x\right) - y\right)\right)\right) \]
      3. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \color{blue}{\left(\left(\frac{1}{2} + \frac{1}{8} \cdot x\right) - y\right)}\right)\right) \]
      4. associate--l+N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \left(\frac{1}{2} + \color{blue}{\left(\frac{1}{8} \cdot x - y\right)}\right)\right)\right) \]
      5. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \color{blue}{\left(\frac{1}{8} \cdot x - y\right)}\right)\right)\right) \]
      6. --lowering--.f64N/A

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

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{\_.f64}\left(\left(x \cdot \frac{1}{8}\right), y\right)\right)\right)\right) \]
      8. *-lowering-*.f6493.9%

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(x, \frac{1}{8}\right), y\right)\right)\right)\right) \]
    7. Simplified93.9%

      \[\leadsto \color{blue}{\log 2 + x \cdot \left(0.5 + \left(x \cdot 0.125 - y\right)\right)} \]
    8. Taylor expanded in x around inf

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(\left(\frac{1}{8} + \frac{1}{2} \cdot \frac{1}{x}\right) - \frac{y}{x}\right)} \]
    9. Simplified93.9%

      \[\leadsto \color{blue}{x \cdot \left(\left(0.5 - x \cdot -0.125\right) - y\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification87.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -6.8 \cdot 10^{-99}:\\ \;\;\;\;0 - y \cdot x\\ \mathbf{elif}\;x \leq 0.00016:\\ \;\;\;\;\mathsf{log1p}\left(x + 1\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(\left(0.5 - x \cdot -0.125\right) - y\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 8: 97.6% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -4.9 \cdot 10^{+29}:\\ \;\;\;\;0 - y \cdot x\\ \mathbf{else}:\\ \;\;\;\;\log 2 + x \cdot \left(0.5 - y\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= x -4.9e+29) (- 0.0 (* y x)) (+ (log 2.0) (* x (- 0.5 y)))))
double code(double x, double y) {
	double tmp;
	if (x <= -4.9e+29) {
		tmp = 0.0 - (y * x);
	} else {
		tmp = log(2.0) + (x * (0.5 - y));
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: tmp
    if (x <= (-4.9d+29)) then
        tmp = 0.0d0 - (y * x)
    else
        tmp = log(2.0d0) + (x * (0.5d0 - y))
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double tmp;
	if (x <= -4.9e+29) {
		tmp = 0.0 - (y * x);
	} else {
		tmp = Math.log(2.0) + (x * (0.5 - y));
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if x <= -4.9e+29:
		tmp = 0.0 - (y * x)
	else:
		tmp = math.log(2.0) + (x * (0.5 - y))
	return tmp
function code(x, y)
	tmp = 0.0
	if (x <= -4.9e+29)
		tmp = Float64(0.0 - Float64(y * x));
	else
		tmp = Float64(log(2.0) + Float64(x * Float64(0.5 - y)));
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if (x <= -4.9e+29)
		tmp = 0.0 - (y * x);
	else
		tmp = log(2.0) + (x * (0.5 - y));
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[LessEqual[x, -4.9e+29], N[(0.0 - N[(y * x), $MachinePrecision]), $MachinePrecision], N[(N[Log[2.0], $MachinePrecision] + N[(x * N[(0.5 - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -4.9 \cdot 10^{+29}:\\
\;\;\;\;0 - y \cdot x\\

\mathbf{else}:\\
\;\;\;\;\log 2 + x \cdot \left(0.5 - y\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -4.9000000000000001e29

    1. Initial program 100.0%

      \[\log \left(1 + e^{x}\right) - x \cdot y \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
      3. exp-lowering-exp.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
      4. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf

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

        \[\leadsto \mathsf{neg}\left(x \cdot y\right) \]
      2. neg-sub0N/A

        \[\leadsto 0 - \color{blue}{x \cdot y} \]
      3. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(0, \color{blue}{\left(x \cdot y\right)}\right) \]
      4. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{\_.f64}\left(0, \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    7. Simplified100.0%

      \[\leadsto \color{blue}{0 - x \cdot y} \]
    8. Step-by-step derivation
      1. sub0-negN/A

        \[\leadsto \mathsf{neg}\left(x \cdot y\right) \]
      2. neg-lowering-neg.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\left(x \cdot y\right)\right) \]
      3. *-commutativeN/A

        \[\leadsto \mathsf{neg.f64}\left(\left(y \cdot x\right)\right) \]
      4. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{*.f64}\left(y, x\right)\right) \]
    9. Applied egg-rr100.0%

      \[\leadsto \color{blue}{-y \cdot x} \]

    if -4.9000000000000001e29 < x

    1. Initial program 99.4%

      \[\log \left(1 + e^{x}\right) - x \cdot y \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
      3. exp-lowering-exp.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
      4. *-lowering-*.f6499.4%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    3. Simplified99.4%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\log 2 + x \cdot \left(\frac{1}{2} - y\right)} \]
    6. Step-by-step derivation
      1. +-lowering-+.f64N/A

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

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

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \color{blue}{\left(\frac{1}{2} - y\right)}\right)\right) \]
      4. --lowering--.f6499.4%

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\frac{1}{2}, \color{blue}{y}\right)\right)\right) \]
    7. Simplified99.4%

      \[\leadsto \color{blue}{\log 2 + x \cdot \left(0.5 - y\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -4.9 \cdot 10^{+29}:\\ \;\;\;\;0 - y \cdot x\\ \mathbf{else}:\\ \;\;\;\;\log 2 + x \cdot \left(0.5 - y\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 9: 81.6% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.15 \cdot 10^{-98}:\\ \;\;\;\;0 - y \cdot x\\ \mathbf{elif}\;x \leq 4.6 \cdot 10^{-5}:\\ \;\;\;\;\log 2\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(\left(0.5 - x \cdot -0.125\right) - y\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= x -1.15e-98)
   (- 0.0 (* y x))
   (if (<= x 4.6e-5) (log 2.0) (* x (- (- 0.5 (* x -0.125)) y)))))
double code(double x, double y) {
	double tmp;
	if (x <= -1.15e-98) {
		tmp = 0.0 - (y * x);
	} else if (x <= 4.6e-5) {
		tmp = log(2.0);
	} else {
		tmp = x * ((0.5 - (x * -0.125)) - y);
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: tmp
    if (x <= (-1.15d-98)) then
        tmp = 0.0d0 - (y * x)
    else if (x <= 4.6d-5) then
        tmp = log(2.0d0)
    else
        tmp = x * ((0.5d0 - (x * (-0.125d0))) - y)
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double tmp;
	if (x <= -1.15e-98) {
		tmp = 0.0 - (y * x);
	} else if (x <= 4.6e-5) {
		tmp = Math.log(2.0);
	} else {
		tmp = x * ((0.5 - (x * -0.125)) - y);
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if x <= -1.15e-98:
		tmp = 0.0 - (y * x)
	elif x <= 4.6e-5:
		tmp = math.log(2.0)
	else:
		tmp = x * ((0.5 - (x * -0.125)) - y)
	return tmp
function code(x, y)
	tmp = 0.0
	if (x <= -1.15e-98)
		tmp = Float64(0.0 - Float64(y * x));
	elseif (x <= 4.6e-5)
		tmp = log(2.0);
	else
		tmp = Float64(x * Float64(Float64(0.5 - Float64(x * -0.125)) - y));
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if (x <= -1.15e-98)
		tmp = 0.0 - (y * x);
	elseif (x <= 4.6e-5)
		tmp = log(2.0);
	else
		tmp = x * ((0.5 - (x * -0.125)) - y);
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[LessEqual[x, -1.15e-98], N[(0.0 - N[(y * x), $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 4.6e-5], N[Log[2.0], $MachinePrecision], N[(x * N[(N[(0.5 - N[(x * -0.125), $MachinePrecision]), $MachinePrecision] - y), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.15 \cdot 10^{-98}:\\
\;\;\;\;0 - y \cdot x\\

\mathbf{elif}\;x \leq 4.6 \cdot 10^{-5}:\\
\;\;\;\;\log 2\\

\mathbf{else}:\\
\;\;\;\;x \cdot \left(\left(0.5 - x \cdot -0.125\right) - y\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -1.15e-98

    1. Initial program 100.0%

      \[\log \left(1 + e^{x}\right) - x \cdot y \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
      3. exp-lowering-exp.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
      4. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf

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

        \[\leadsto \mathsf{neg}\left(x \cdot y\right) \]
      2. neg-sub0N/A

        \[\leadsto 0 - \color{blue}{x \cdot y} \]
      3. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(0, \color{blue}{\left(x \cdot y\right)}\right) \]
      4. *-lowering-*.f6491.2%

        \[\leadsto \mathsf{\_.f64}\left(0, \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    7. Simplified91.2%

      \[\leadsto \color{blue}{0 - x \cdot y} \]
    8. Step-by-step derivation
      1. sub0-negN/A

        \[\leadsto \mathsf{neg}\left(x \cdot y\right) \]
      2. neg-lowering-neg.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\left(x \cdot y\right)\right) \]
      3. *-commutativeN/A

        \[\leadsto \mathsf{neg.f64}\left(\left(y \cdot x\right)\right) \]
      4. *-lowering-*.f6491.2%

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{*.f64}\left(y, x\right)\right) \]
    9. Applied egg-rr91.2%

      \[\leadsto \color{blue}{-y \cdot x} \]

    if -1.15e-98 < x < 4.6e-5

    1. Initial program 99.9%

      \[\log \left(1 + e^{x}\right) - x \cdot y \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
      3. exp-lowering-exp.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
      4. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\log 2} \]
    6. Step-by-step derivation
      1. log-lowering-log.f6483.7%

        \[\leadsto \mathsf{log.f64}\left(2\right) \]
    7. Simplified83.7%

      \[\leadsto \color{blue}{\log 2} \]

    if 4.6e-5 < x

    1. Initial program 92.9%

      \[\log \left(1 + e^{x}\right) - x \cdot y \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
      3. exp-lowering-exp.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
      4. *-lowering-*.f6492.9%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    3. Simplified92.9%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\log 2 + x \cdot \left(\left(\frac{1}{2} + \frac{1}{8} \cdot x\right) - y\right)} \]
    6. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\log 2, \color{blue}{\left(x \cdot \left(\left(\frac{1}{2} + \frac{1}{8} \cdot x\right) - y\right)\right)}\right) \]
      2. log-lowering-log.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \left(\color{blue}{x} \cdot \left(\left(\frac{1}{2} + \frac{1}{8} \cdot x\right) - y\right)\right)\right) \]
      3. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \color{blue}{\left(\left(\frac{1}{2} + \frac{1}{8} \cdot x\right) - y\right)}\right)\right) \]
      4. associate--l+N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \left(\frac{1}{2} + \color{blue}{\left(\frac{1}{8} \cdot x - y\right)}\right)\right)\right) \]
      5. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \color{blue}{\left(\frac{1}{8} \cdot x - y\right)}\right)\right)\right) \]
      6. --lowering--.f64N/A

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

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{\_.f64}\left(\left(x \cdot \frac{1}{8}\right), y\right)\right)\right)\right) \]
      8. *-lowering-*.f6493.9%

        \[\leadsto \mathsf{+.f64}\left(\mathsf{log.f64}\left(2\right), \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{\_.f64}\left(\mathsf{*.f64}\left(x, \frac{1}{8}\right), y\right)\right)\right)\right) \]
    7. Simplified93.9%

      \[\leadsto \color{blue}{\log 2 + x \cdot \left(0.5 + \left(x \cdot 0.125 - y\right)\right)} \]
    8. Taylor expanded in x around inf

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(\left(\frac{1}{8} + \frac{1}{2} \cdot \frac{1}{x}\right) - \frac{y}{x}\right)} \]
    9. Simplified93.9%

      \[\leadsto \color{blue}{x \cdot \left(\left(0.5 - x \cdot -0.125\right) - y\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification87.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.15 \cdot 10^{-98}:\\ \;\;\;\;0 - y \cdot x\\ \mathbf{elif}\;x \leq 4.6 \cdot 10^{-5}:\\ \;\;\;\;\log 2\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(\left(0.5 - x \cdot -0.125\right) - y\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 10: 97.3% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -4.9 \cdot 10^{+29}:\\ \;\;\;\;0 - y \cdot x\\ \mathbf{else}:\\ \;\;\;\;\mathsf{log1p}\left(1\right) - y \cdot x\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= x -4.9e+29) (- 0.0 (* y x)) (- (log1p 1.0) (* y x))))
double code(double x, double y) {
	double tmp;
	if (x <= -4.9e+29) {
		tmp = 0.0 - (y * x);
	} else {
		tmp = log1p(1.0) - (y * x);
	}
	return tmp;
}
public static double code(double x, double y) {
	double tmp;
	if (x <= -4.9e+29) {
		tmp = 0.0 - (y * x);
	} else {
		tmp = Math.log1p(1.0) - (y * x);
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if x <= -4.9e+29:
		tmp = 0.0 - (y * x)
	else:
		tmp = math.log1p(1.0) - (y * x)
	return tmp
function code(x, y)
	tmp = 0.0
	if (x <= -4.9e+29)
		tmp = Float64(0.0 - Float64(y * x));
	else
		tmp = Float64(log1p(1.0) - Float64(y * x));
	end
	return tmp
end
code[x_, y_] := If[LessEqual[x, -4.9e+29], N[(0.0 - N[(y * x), $MachinePrecision]), $MachinePrecision], N[(N[Log[1 + 1.0], $MachinePrecision] - N[(y * x), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -4.9 \cdot 10^{+29}:\\
\;\;\;\;0 - y \cdot x\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -4.9000000000000001e29

    1. Initial program 100.0%

      \[\log \left(1 + e^{x}\right) - x \cdot y \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
      3. exp-lowering-exp.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
      4. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf

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

        \[\leadsto \mathsf{neg}\left(x \cdot y\right) \]
      2. neg-sub0N/A

        \[\leadsto 0 - \color{blue}{x \cdot y} \]
      3. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(0, \color{blue}{\left(x \cdot y\right)}\right) \]
      4. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{\_.f64}\left(0, \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    7. Simplified100.0%

      \[\leadsto \color{blue}{0 - x \cdot y} \]
    8. Step-by-step derivation
      1. sub0-negN/A

        \[\leadsto \mathsf{neg}\left(x \cdot y\right) \]
      2. neg-lowering-neg.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\left(x \cdot y\right)\right) \]
      3. *-commutativeN/A

        \[\leadsto \mathsf{neg.f64}\left(\left(y \cdot x\right)\right) \]
      4. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{*.f64}\left(y, x\right)\right) \]
    9. Applied egg-rr100.0%

      \[\leadsto \color{blue}{-y \cdot x} \]

    if -4.9000000000000001e29 < x

    1. Initial program 99.4%

      \[\log \left(1 + e^{x}\right) - x \cdot y \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
      3. exp-lowering-exp.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
      4. *-lowering-*.f6499.4%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    3. Simplified99.4%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0

      \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\color{blue}{1}\right), \mathsf{*.f64}\left(x, y\right)\right) \]
    6. Step-by-step derivation
      1. Simplified99.0%

        \[\leadsto \mathsf{log1p}\left(\color{blue}{1}\right) - x \cdot y \]
    7. Recombined 2 regimes into one program.
    8. Final simplification99.3%

      \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -4.9 \cdot 10^{+29}:\\ \;\;\;\;0 - y \cdot x\\ \mathbf{else}:\\ \;\;\;\;\mathsf{log1p}\left(1\right) - y \cdot x\\ \end{array} \]
    9. Add Preprocessing

    Alternative 11: 53.5% accurate, 41.4× speedup?

    \[\begin{array}{l} \\ 0 - y \cdot x \end{array} \]
    (FPCore (x y) :precision binary64 (- 0.0 (* y x)))
    double code(double x, double y) {
    	return 0.0 - (y * x);
    }
    
    real(8) function code(x, y)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        code = 0.0d0 - (y * x)
    end function
    
    public static double code(double x, double y) {
    	return 0.0 - (y * x);
    }
    
    def code(x, y):
    	return 0.0 - (y * x)
    
    function code(x, y)
    	return Float64(0.0 - Float64(y * x))
    end
    
    function tmp = code(x, y)
    	tmp = 0.0 - (y * x);
    end
    
    code[x_, y_] := N[(0.0 - N[(y * x), $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    0 - y \cdot x
    \end{array}
    
    Derivation
    1. Initial program 99.6%

      \[\log \left(1 + e^{x}\right) - x \cdot y \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
      3. exp-lowering-exp.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
      4. *-lowering-*.f6499.6%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    3. Simplified99.6%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf

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

        \[\leadsto \mathsf{neg}\left(x \cdot y\right) \]
      2. neg-sub0N/A

        \[\leadsto 0 - \color{blue}{x \cdot y} \]
      3. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(0, \color{blue}{\left(x \cdot y\right)}\right) \]
      4. *-lowering-*.f6448.7%

        \[\leadsto \mathsf{\_.f64}\left(0, \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    7. Simplified48.7%

      \[\leadsto \color{blue}{0 - x \cdot y} \]
    8. Step-by-step derivation
      1. sub0-negN/A

        \[\leadsto \mathsf{neg}\left(x \cdot y\right) \]
      2. neg-lowering-neg.f64N/A

        \[\leadsto \mathsf{neg.f64}\left(\left(x \cdot y\right)\right) \]
      3. *-commutativeN/A

        \[\leadsto \mathsf{neg.f64}\left(\left(y \cdot x\right)\right) \]
      4. *-lowering-*.f6448.7%

        \[\leadsto \mathsf{neg.f64}\left(\mathsf{*.f64}\left(y, x\right)\right) \]
    9. Applied egg-rr48.7%

      \[\leadsto \color{blue}{-y \cdot x} \]
    10. Final simplification48.7%

      \[\leadsto 0 - y \cdot x \]
    11. Add Preprocessing

    Alternative 12: 2.2% accurate, 69.0× speedup?

    \[\begin{array}{l} \\ y \cdot x \end{array} \]
    (FPCore (x y) :precision binary64 (* y x))
    double code(double x, double y) {
    	return y * x;
    }
    
    real(8) function code(x, y)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        code = y * x
    end function
    
    public static double code(double x, double y) {
    	return y * x;
    }
    
    def code(x, y):
    	return y * x
    
    function code(x, y)
    	return Float64(y * x)
    end
    
    function tmp = code(x, y)
    	tmp = y * x;
    end
    
    code[x_, y_] := N[(y * x), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    y \cdot x
    \end{array}
    
    Derivation
    1. Initial program 99.6%

      \[\log \left(1 + e^{x}\right) - x \cdot y \]
    2. Step-by-step derivation
      1. --lowering--.f64N/A

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\left(e^{x}\right)\right), \left(\color{blue}{x} \cdot y\right)\right) \]
      3. exp-lowering-exp.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \left(x \cdot y\right)\right) \]
      4. *-lowering-*.f6499.6%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{log1p.f64}\left(\mathsf{exp.f64}\left(x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    3. Simplified99.6%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(e^{x}\right) - x \cdot y} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf

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

        \[\leadsto \mathsf{neg}\left(x \cdot y\right) \]
      2. neg-sub0N/A

        \[\leadsto 0 - \color{blue}{x \cdot y} \]
      3. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(0, \color{blue}{\left(x \cdot y\right)}\right) \]
      4. *-lowering-*.f6448.7%

        \[\leadsto \mathsf{\_.f64}\left(0, \mathsf{*.f64}\left(x, \color{blue}{y}\right)\right) \]
    7. Simplified48.7%

      \[\leadsto \color{blue}{0 - x \cdot y} \]
    8. Step-by-step derivation
      1. sub0-negN/A

        \[\leadsto \mathsf{neg}\left(x \cdot y\right) \]
      2. +-lft-identityN/A

        \[\leadsto \mathsf{neg}\left(\left(0 + x \cdot y\right)\right) \]
      3. flip3-+N/A

        \[\leadsto \mathsf{neg}\left(\frac{{0}^{3} + {\left(x \cdot y\right)}^{3}}{0 \cdot 0 + \left(\left(x \cdot y\right) \cdot \left(x \cdot y\right) - 0 \cdot \left(x \cdot y\right)\right)}\right) \]
      4. metadata-evalN/A

        \[\leadsto \mathsf{neg}\left(\frac{0 + {\left(x \cdot y\right)}^{3}}{0 \cdot 0 + \left(\left(x \cdot y\right) \cdot \left(x \cdot y\right) - 0 \cdot \left(x \cdot y\right)\right)}\right) \]
      5. +-lft-identityN/A

        \[\leadsto \mathsf{neg}\left(\frac{{\left(x \cdot y\right)}^{3}}{0 \cdot 0 + \left(\left(x \cdot y\right) \cdot \left(x \cdot y\right) - 0 \cdot \left(x \cdot y\right)\right)}\right) \]
      6. distribute-neg-fracN/A

        \[\leadsto \frac{\mathsf{neg}\left({\left(x \cdot y\right)}^{3}\right)}{\color{blue}{0 \cdot 0 + \left(\left(x \cdot y\right) \cdot \left(x \cdot y\right) - 0 \cdot \left(x \cdot y\right)\right)}} \]
      7. cube-negN/A

        \[\leadsto \frac{{\left(\mathsf{neg}\left(x \cdot y\right)\right)}^{3}}{\color{blue}{0 \cdot 0} + \left(\left(x \cdot y\right) \cdot \left(x \cdot y\right) - 0 \cdot \left(x \cdot y\right)\right)} \]
      8. sqr-powN/A

        \[\leadsto \frac{{\left(\mathsf{neg}\left(x \cdot y\right)\right)}^{\left(\frac{3}{2}\right)} \cdot {\left(\mathsf{neg}\left(x \cdot y\right)\right)}^{\left(\frac{3}{2}\right)}}{\color{blue}{0 \cdot 0} + \left(\left(x \cdot y\right) \cdot \left(x \cdot y\right) - 0 \cdot \left(x \cdot y\right)\right)} \]
      9. pow-prod-downN/A

        \[\leadsto \frac{{\left(\left(\mathsf{neg}\left(x \cdot y\right)\right) \cdot \left(\mathsf{neg}\left(x \cdot y\right)\right)\right)}^{\left(\frac{3}{2}\right)}}{\color{blue}{0 \cdot 0} + \left(\left(x \cdot y\right) \cdot \left(x \cdot y\right) - 0 \cdot \left(x \cdot y\right)\right)} \]
      10. sqr-negN/A

        \[\leadsto \frac{{\left(\left(x \cdot y\right) \cdot \left(x \cdot y\right)\right)}^{\left(\frac{3}{2}\right)}}{\color{blue}{0} \cdot 0 + \left(\left(x \cdot y\right) \cdot \left(x \cdot y\right) - 0 \cdot \left(x \cdot y\right)\right)} \]
      11. pow-prod-downN/A

        \[\leadsto \frac{{\left(x \cdot y\right)}^{\left(\frac{3}{2}\right)} \cdot {\left(x \cdot y\right)}^{\left(\frac{3}{2}\right)}}{\color{blue}{0 \cdot 0} + \left(\left(x \cdot y\right) \cdot \left(x \cdot y\right) - 0 \cdot \left(x \cdot y\right)\right)} \]
      12. sqr-powN/A

        \[\leadsto \frac{{\left(x \cdot y\right)}^{3}}{\color{blue}{0 \cdot 0} + \left(\left(x \cdot y\right) \cdot \left(x \cdot y\right) - 0 \cdot \left(x \cdot y\right)\right)} \]
      13. +-lft-identityN/A

        \[\leadsto \frac{0 + {\left(x \cdot y\right)}^{3}}{\color{blue}{0 \cdot 0} + \left(\left(x \cdot y\right) \cdot \left(x \cdot y\right) - 0 \cdot \left(x \cdot y\right)\right)} \]
      14. metadata-evalN/A

        \[\leadsto \frac{{0}^{3} + {\left(x \cdot y\right)}^{3}}{\color{blue}{0} \cdot 0 + \left(\left(x \cdot y\right) \cdot \left(x \cdot y\right) - 0 \cdot \left(x \cdot y\right)\right)} \]
      15. flip3-+N/A

        \[\leadsto 0 + \color{blue}{x \cdot y} \]
      16. +-lft-identityN/A

        \[\leadsto x \cdot \color{blue}{y} \]
      17. *-commutativeN/A

        \[\leadsto y \cdot \color{blue}{x} \]
      18. *-lowering-*.f642.2%

        \[\leadsto \mathsf{*.f64}\left(y, \color{blue}{x}\right) \]
    9. Applied egg-rr2.2%

      \[\leadsto \color{blue}{y \cdot x} \]
    10. Add Preprocessing

    Developer Target 1: 99.9% accurate, 1.0× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 0:\\ \;\;\;\;\log \left(1 + e^{x}\right) - x \cdot y\\ \mathbf{else}:\\ \;\;\;\;\log \left(1 + e^{-x}\right) - \left(-x\right) \cdot \left(1 - y\right)\\ \end{array} \end{array} \]
    (FPCore (x y)
     :precision binary64
     (if (<= x 0.0)
       (- (log (+ 1.0 (exp x))) (* x y))
       (- (log (+ 1.0 (exp (- x)))) (* (- x) (- 1.0 y)))))
    double code(double x, double y) {
    	double tmp;
    	if (x <= 0.0) {
    		tmp = log((1.0 + exp(x))) - (x * y);
    	} else {
    		tmp = log((1.0 + exp(-x))) - (-x * (1.0 - y));
    	}
    	return tmp;
    }
    
    real(8) function code(x, y)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        real(8) :: tmp
        if (x <= 0.0d0) then
            tmp = log((1.0d0 + exp(x))) - (x * y)
        else
            tmp = log((1.0d0 + exp(-x))) - (-x * (1.0d0 - y))
        end if
        code = tmp
    end function
    
    public static double code(double x, double y) {
    	double tmp;
    	if (x <= 0.0) {
    		tmp = Math.log((1.0 + Math.exp(x))) - (x * y);
    	} else {
    		tmp = Math.log((1.0 + Math.exp(-x))) - (-x * (1.0 - y));
    	}
    	return tmp;
    }
    
    def code(x, y):
    	tmp = 0
    	if x <= 0.0:
    		tmp = math.log((1.0 + math.exp(x))) - (x * y)
    	else:
    		tmp = math.log((1.0 + math.exp(-x))) - (-x * (1.0 - y))
    	return tmp
    
    function code(x, y)
    	tmp = 0.0
    	if (x <= 0.0)
    		tmp = Float64(log(Float64(1.0 + exp(x))) - Float64(x * y));
    	else
    		tmp = Float64(log(Float64(1.0 + exp(Float64(-x)))) - Float64(Float64(-x) * Float64(1.0 - y)));
    	end
    	return tmp
    end
    
    function tmp_2 = code(x, y)
    	tmp = 0.0;
    	if (x <= 0.0)
    		tmp = log((1.0 + exp(x))) - (x * y);
    	else
    		tmp = log((1.0 + exp(-x))) - (-x * (1.0 - y));
    	end
    	tmp_2 = tmp;
    end
    
    code[x_, y_] := If[LessEqual[x, 0.0], N[(N[Log[N[(1.0 + N[Exp[x], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - N[(x * y), $MachinePrecision]), $MachinePrecision], N[(N[Log[N[(1.0 + N[Exp[(-x)], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - N[((-x) * N[(1.0 - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq 0:\\
    \;\;\;\;\log \left(1 + e^{x}\right) - x \cdot y\\
    
    \mathbf{else}:\\
    \;\;\;\;\log \left(1 + e^{-x}\right) - \left(-x\right) \cdot \left(1 - y\right)\\
    
    
    \end{array}
    \end{array}
    

    Reproduce

    ?
    herbie shell --seed 2024184 
    (FPCore (x y)
      :name "Logistic regression 2"
      :precision binary64
    
      :alt
      (! :herbie-platform default (if (<= x 0) (- (log (+ 1 (exp x))) (* x y)) (- (log (+ 1 (exp (- x)))) (* (- x) (- 1 y)))))
    
      (- (log (+ 1.0 (exp x))) (* x y)))