Logarithmic Transform

Percentage Accurate: 41.5% → 99.3%
Time: 28.9s
Alternatives: 9
Speedup: 19.8×

Specification

?
\[\begin{array}{l} \\ c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \end{array} \]
(FPCore (c x y)
 :precision binary64
 (* c (log (+ 1.0 (* (- (pow (E) x) 1.0) y)))))
\begin{array}{l}

\\
c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot 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 9 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: 41.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \end{array} \]
(FPCore (c x y)
 :precision binary64
 (* c (log (+ 1.0 (* (- (pow (E) x) 1.0) y)))))
\begin{array}{l}

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

Alternative 1: 99.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -2.05 \cdot 10^{-16} \lor \neg \left(y \leq 3 \cdot 10^{-31}\right):\\ \;\;\;\;\mathsf{log1p}\left(\mathsf{expm1}\left(x\right) \cdot y\right) \cdot c\\ \mathbf{else}:\\ \;\;\;\;\left(c \cdot y\right) \cdot \mathsf{expm1}\left(x\right)\\ \end{array} \end{array} \]
(FPCore (c x y)
 :precision binary64
 (if (or (<= y -2.05e-16) (not (<= y 3e-31)))
   (* (log1p (* (expm1 x) y)) c)
   (* (* c y) (expm1 x))))
double code(double c, double x, double y) {
	double tmp;
	if ((y <= -2.05e-16) || !(y <= 3e-31)) {
		tmp = log1p((expm1(x) * y)) * c;
	} else {
		tmp = (c * y) * expm1(x);
	}
	return tmp;
}
public static double code(double c, double x, double y) {
	double tmp;
	if ((y <= -2.05e-16) || !(y <= 3e-31)) {
		tmp = Math.log1p((Math.expm1(x) * y)) * c;
	} else {
		tmp = (c * y) * Math.expm1(x);
	}
	return tmp;
}
def code(c, x, y):
	tmp = 0
	if (y <= -2.05e-16) or not (y <= 3e-31):
		tmp = math.log1p((math.expm1(x) * y)) * c
	else:
		tmp = (c * y) * math.expm1(x)
	return tmp
function code(c, x, y)
	tmp = 0.0
	if ((y <= -2.05e-16) || !(y <= 3e-31))
		tmp = Float64(log1p(Float64(expm1(x) * y)) * c);
	else
		tmp = Float64(Float64(c * y) * expm1(x));
	end
	return tmp
end
code[c_, x_, y_] := If[Or[LessEqual[y, -2.05e-16], N[Not[LessEqual[y, 3e-31]], $MachinePrecision]], N[(N[Log[1 + N[(N[(Exp[x] - 1), $MachinePrecision] * y), $MachinePrecision]], $MachinePrecision] * c), $MachinePrecision], N[(N[(c * y), $MachinePrecision] * N[(Exp[x] - 1), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -2.05 \cdot 10^{-16} \lor \neg \left(y \leq 3 \cdot 10^{-31}\right):\\
\;\;\;\;\mathsf{log1p}\left(\mathsf{expm1}\left(x\right) \cdot y\right) \cdot c\\

\mathbf{else}:\\
\;\;\;\;\left(c \cdot y\right) \cdot \mathsf{expm1}\left(x\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < -2.05000000000000003e-16 or 2.99999999999999981e-31 < y

    1. Initial program 40.7%

      \[c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. *-commutativeN/A

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

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

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

        \[\leadsto \color{blue}{\mathsf{log1p}\left(y \cdot \left({\mathsf{E}\left(\right)}^{x} - 1\right)\right)} \cdot c \]
      5. lower-*.f64N/A

        \[\leadsto \mathsf{log1p}\left(\color{blue}{y \cdot \left({\mathsf{E}\left(\right)}^{x} - 1\right)}\right) \cdot c \]
      6. pow-to-expN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\color{blue}{e^{\log \mathsf{E}\left(\right) \cdot x}} - 1\right)\right) \cdot c \]
      7. log-EN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(e^{\color{blue}{1} \cdot x} - 1\right)\right) \cdot c \]
      8. *-commutativeN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(e^{\color{blue}{x \cdot 1}} - 1\right)\right) \cdot c \]
      9. lower-expm1.f64N/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(x \cdot 1\right)}\right) \cdot c \]
      10. lower-*.f6498.7

        \[\leadsto \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(\color{blue}{x \cdot 1}\right)\right) \cdot c \]
    4. Applied rewrites98.7%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(x \cdot 1\right)\right) \cdot c} \]
    5. Step-by-step derivation
      1. *-commutativeN/A

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

        \[\leadsto \log \left(1 + y \cdot \left(e^{\color{blue}{\log \mathsf{E}\left(\right)} \cdot x} - 1\right)\right) \cdot c \]
      3. pow-to-expN/A

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

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

        \[\leadsto \color{blue}{\log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \cdot c} \]
    6. Applied rewrites98.7%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(\mathsf{expm1}\left(x\right) \cdot y\right) \cdot c} \]

    if -2.05000000000000003e-16 < y < 2.99999999999999981e-31

    1. Initial program 43.1%

      \[c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \]
    2. Add Preprocessing
    3. Taylor expanded in y around 0

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

        \[\leadsto \left(c \cdot y\right) \cdot \color{blue}{\left({\mathsf{E}\left(\right)}^{x} - 1\right)} \]
      2. lower-*.f64N/A

        \[\leadsto \left(c \cdot y\right) \cdot \color{blue}{\left({\mathsf{E}\left(\right)}^{x} - 1\right)} \]
      3. lower-*.f64N/A

        \[\leadsto \left(c \cdot y\right) \cdot \left(\color{blue}{{\mathsf{E}\left(\right)}^{x}} - 1\right) \]
      4. pow-to-expN/A

        \[\leadsto \left(c \cdot y\right) \cdot \left(e^{\log \mathsf{E}\left(\right) \cdot x} - 1\right) \]
      5. log-EN/A

        \[\leadsto \left(c \cdot y\right) \cdot \left(e^{1 \cdot x} - 1\right) \]
      6. *-commutativeN/A

        \[\leadsto \left(c \cdot y\right) \cdot \left(e^{x \cdot 1} - 1\right) \]
      7. lower-expm1.f64N/A

        \[\leadsto \left(c \cdot y\right) \cdot \mathsf{expm1}\left(x \cdot 1\right) \]
      8. lower-*.f6499.9

        \[\leadsto \left(c \cdot y\right) \cdot \mathsf{expm1}\left(x \cdot 1\right) \]
    5. Applied rewrites99.9%

      \[\leadsto \color{blue}{\left(c \cdot y\right) \cdot \mathsf{expm1}\left(x \cdot 1\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -2.05 \cdot 10^{-16} \lor \neg \left(y \leq 3 \cdot 10^{-31}\right):\\ \;\;\;\;\mathsf{log1p}\left(\mathsf{expm1}\left(x\right) \cdot y\right) \cdot c\\ \mathbf{else}:\\ \;\;\;\;\left(c \cdot y\right) \cdot \mathsf{expm1}\left(x\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 83.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;{\mathsf{E}\left(\right)}^{x} - 1 \leq -2 \cdot 10^{-8}:\\ \;\;\;\;\left(\mathsf{expm1}\left(x\right) \cdot y\right) \cdot c\\ \mathbf{else}:\\ \;\;\;\;\mathsf{log1p}\left(y \cdot x\right) \cdot c\\ \end{array} \end{array} \]
(FPCore (c x y)
 :precision binary64
 (if (<= (- (pow (E) x) 1.0) -2e-8)
   (* (* (expm1 x) y) c)
   (* (log1p (* y x)) c)))
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;{\mathsf{E}\left(\right)}^{x} - 1 \leq -2 \cdot 10^{-8}:\\
\;\;\;\;\left(\mathsf{expm1}\left(x\right) \cdot y\right) \cdot c\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (pow.f64 (E.f64) x) #s(literal 1 binary64)) < -2e-8

    1. Initial program 50.7%

      \[c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. *-commutativeN/A

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

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

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

        \[\leadsto \color{blue}{\mathsf{log1p}\left(y \cdot \left({\mathsf{E}\left(\right)}^{x} - 1\right)\right)} \cdot c \]
      5. lower-*.f64N/A

        \[\leadsto \mathsf{log1p}\left(\color{blue}{y \cdot \left({\mathsf{E}\left(\right)}^{x} - 1\right)}\right) \cdot c \]
      6. pow-to-expN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\color{blue}{e^{\log \mathsf{E}\left(\right) \cdot x}} - 1\right)\right) \cdot c \]
      7. log-EN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(e^{\color{blue}{1} \cdot x} - 1\right)\right) \cdot c \]
      8. *-commutativeN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(e^{\color{blue}{x \cdot 1}} - 1\right)\right) \cdot c \]
      9. lower-expm1.f64N/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(x \cdot 1\right)}\right) \cdot c \]
      10. lower-*.f6499.7

        \[\leadsto \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(\color{blue}{x \cdot 1}\right)\right) \cdot c \]
    4. Applied rewrites99.7%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(x \cdot 1\right)\right) \cdot c} \]
    5. Taylor expanded in y around 0

      \[\leadsto \color{blue}{\left(y \cdot \left(e^{x} - 1\right)\right)} \cdot c \]
    6. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \left(y \cdot \left(e^{x} - 1\right)\right) \cdot c \]
      2. *-commutativeN/A

        \[\leadsto \left(y \cdot \left(e^{x} - 1\right)\right) \cdot c \]
      3. log-EN/A

        \[\leadsto \left(y \cdot \left(e^{x} - 1\right)\right) \cdot c \]
      4. pow-to-expN/A

        \[\leadsto \left(y \cdot \left(e^{x} - 1\right)\right) \cdot c \]
      5. *-commutativeN/A

        \[\leadsto \left(\left(e^{x} - 1\right) \cdot \color{blue}{y}\right) \cdot c \]
      6. *-rgt-identityN/A

        \[\leadsto \left(\left(e^{x \cdot 1} - 1\right) \cdot y\right) \cdot c \]
      7. *-commutativeN/A

        \[\leadsto \left(\left(e^{1 \cdot x} - 1\right) \cdot y\right) \cdot c \]
      8. log-EN/A

        \[\leadsto \left(\left(e^{\log \mathsf{E}\left(\right) \cdot x} - 1\right) \cdot y\right) \cdot c \]
      9. pow-to-expN/A

        \[\leadsto \left(\left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \cdot c \]
      10. lower-*.f64N/A

        \[\leadsto \left(\left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot \color{blue}{y}\right) \cdot c \]
      11. pow-to-expN/A

        \[\leadsto \left(\left(e^{\log \mathsf{E}\left(\right) \cdot x} - 1\right) \cdot y\right) \cdot c \]
      12. log-EN/A

        \[\leadsto \left(\left(e^{1 \cdot x} - 1\right) \cdot y\right) \cdot c \]
      13. *-commutativeN/A

        \[\leadsto \left(\left(e^{x \cdot 1} - 1\right) \cdot y\right) \cdot c \]
      14. *-rgt-identityN/A

        \[\leadsto \left(\left(e^{x} - 1\right) \cdot y\right) \cdot c \]
      15. lower-expm1.f6465.6

        \[\leadsto \left(\mathsf{expm1}\left(x\right) \cdot y\right) \cdot c \]
    7. Applied rewrites65.6%

      \[\leadsto \color{blue}{\left(\mathsf{expm1}\left(x\right) \cdot y\right)} \cdot c \]

    if -2e-8 < (-.f64 (pow.f64 (E.f64) x) #s(literal 1 binary64))

    1. Initial program 37.6%

      \[c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. *-commutativeN/A

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

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

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

        \[\leadsto \color{blue}{\mathsf{log1p}\left(y \cdot \left({\mathsf{E}\left(\right)}^{x} - 1\right)\right)} \cdot c \]
      5. lower-*.f64N/A

        \[\leadsto \mathsf{log1p}\left(\color{blue}{y \cdot \left({\mathsf{E}\left(\right)}^{x} - 1\right)}\right) \cdot c \]
      6. pow-to-expN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\color{blue}{e^{\log \mathsf{E}\left(\right) \cdot x}} - 1\right)\right) \cdot c \]
      7. log-EN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(e^{\color{blue}{1} \cdot x} - 1\right)\right) \cdot c \]
      8. *-commutativeN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(e^{\color{blue}{x \cdot 1}} - 1\right)\right) \cdot c \]
      9. lower-expm1.f64N/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(x \cdot 1\right)}\right) \cdot c \]
      10. lower-*.f6489.2

        \[\leadsto \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(\color{blue}{x \cdot 1}\right)\right) \cdot c \]
    4. Applied rewrites89.2%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(x \cdot 1\right)\right) \cdot c} \]
    5. Taylor expanded in x around 0

      \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{x}\right) \cdot c \]
    6. Step-by-step derivation
      1. *-commutative88.6

        \[\leadsto \mathsf{log1p}\left(y \cdot x\right) \cdot c \]
      2. log-E88.6

        \[\leadsto \mathsf{log1p}\left(y \cdot x\right) \cdot c \]
      3. pow-to-exp88.6

        \[\leadsto \mathsf{log1p}\left(y \cdot x\right) \cdot c \]
    7. Applied rewrites88.6%

      \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{x}\right) \cdot c \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 3: 89.8% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -190:\\ \;\;\;\;\mathsf{log1p}\left(y \cdot x\right) \cdot c\\ \mathbf{elif}\;y \leq 5.2 \cdot 10^{+42}:\\ \;\;\;\;\left(c \cdot y\right) \cdot \mathsf{expm1}\left(x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{log1p}\left(\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.041666666666666664, x, 0.16666666666666666\right), x, 0.5\right), x, 1\right) \cdot x\right) \cdot y\right) \cdot c\\ \end{array} \end{array} \]
(FPCore (c x y)
 :precision binary64
 (if (<= y -190.0)
   (* (log1p (* y x)) c)
   (if (<= y 5.2e+42)
     (* (* c y) (expm1 x))
     (*
      (log1p
       (*
        (*
         (fma
          (fma (fma 0.041666666666666664 x 0.16666666666666666) x 0.5)
          x
          1.0)
         x)
        y))
      c))))
double code(double c, double x, double y) {
	double tmp;
	if (y <= -190.0) {
		tmp = log1p((y * x)) * c;
	} else if (y <= 5.2e+42) {
		tmp = (c * y) * expm1(x);
	} else {
		tmp = log1p(((fma(fma(fma(0.041666666666666664, x, 0.16666666666666666), x, 0.5), x, 1.0) * x) * y)) * c;
	}
	return tmp;
}
function code(c, x, y)
	tmp = 0.0
	if (y <= -190.0)
		tmp = Float64(log1p(Float64(y * x)) * c);
	elseif (y <= 5.2e+42)
		tmp = Float64(Float64(c * y) * expm1(x));
	else
		tmp = Float64(log1p(Float64(Float64(fma(fma(fma(0.041666666666666664, x, 0.16666666666666666), x, 0.5), x, 1.0) * x) * y)) * c);
	end
	return tmp
end
code[c_, x_, y_] := If[LessEqual[y, -190.0], N[(N[Log[1 + N[(y * x), $MachinePrecision]], $MachinePrecision] * c), $MachinePrecision], If[LessEqual[y, 5.2e+42], N[(N[(c * y), $MachinePrecision] * N[(Exp[x] - 1), $MachinePrecision]), $MachinePrecision], N[(N[Log[1 + N[(N[(N[(N[(N[(0.041666666666666664 * x + 0.16666666666666666), $MachinePrecision] * x + 0.5), $MachinePrecision] * x + 1.0), $MachinePrecision] * x), $MachinePrecision] * y), $MachinePrecision]], $MachinePrecision] * c), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -190:\\
\;\;\;\;\mathsf{log1p}\left(y \cdot x\right) \cdot c\\

\mathbf{elif}\;y \leq 5.2 \cdot 10^{+42}:\\
\;\;\;\;\left(c \cdot y\right) \cdot \mathsf{expm1}\left(x\right)\\

\mathbf{else}:\\
\;\;\;\;\mathsf{log1p}\left(\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.041666666666666664, x, 0.16666666666666666\right), x, 0.5\right), x, 1\right) \cdot x\right) \cdot y\right) \cdot c\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y < -190

    1. Initial program 52.6%

      \[c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. *-commutativeN/A

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

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

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

        \[\leadsto \color{blue}{\mathsf{log1p}\left(y \cdot \left({\mathsf{E}\left(\right)}^{x} - 1\right)\right)} \cdot c \]
      5. lower-*.f64N/A

        \[\leadsto \mathsf{log1p}\left(\color{blue}{y \cdot \left({\mathsf{E}\left(\right)}^{x} - 1\right)}\right) \cdot c \]
      6. pow-to-expN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\color{blue}{e^{\log \mathsf{E}\left(\right) \cdot x}} - 1\right)\right) \cdot c \]
      7. log-EN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(e^{\color{blue}{1} \cdot x} - 1\right)\right) \cdot c \]
      8. *-commutativeN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(e^{\color{blue}{x \cdot 1}} - 1\right)\right) \cdot c \]
      9. lower-expm1.f64N/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(x \cdot 1\right)}\right) \cdot c \]
      10. lower-*.f6499.6

        \[\leadsto \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(\color{blue}{x \cdot 1}\right)\right) \cdot c \]
    4. Applied rewrites99.6%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(x \cdot 1\right)\right) \cdot c} \]
    5. Taylor expanded in x around 0

      \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{x}\right) \cdot c \]
    6. Step-by-step derivation
      1. *-commutative61.9

        \[\leadsto \mathsf{log1p}\left(y \cdot x\right) \cdot c \]
      2. log-E61.9

        \[\leadsto \mathsf{log1p}\left(y \cdot x\right) \cdot c \]
      3. pow-to-exp61.9

        \[\leadsto \mathsf{log1p}\left(y \cdot x\right) \cdot c \]
    7. Applied rewrites61.9%

      \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{x}\right) \cdot c \]

    if -190 < y < 5.1999999999999998e42

    1. Initial program 42.2%

      \[c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \]
    2. Add Preprocessing
    3. Taylor expanded in y around 0

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

        \[\leadsto \left(c \cdot y\right) \cdot \color{blue}{\left({\mathsf{E}\left(\right)}^{x} - 1\right)} \]
      2. lower-*.f64N/A

        \[\leadsto \left(c \cdot y\right) \cdot \color{blue}{\left({\mathsf{E}\left(\right)}^{x} - 1\right)} \]
      3. lower-*.f64N/A

        \[\leadsto \left(c \cdot y\right) \cdot \left(\color{blue}{{\mathsf{E}\left(\right)}^{x}} - 1\right) \]
      4. pow-to-expN/A

        \[\leadsto \left(c \cdot y\right) \cdot \left(e^{\log \mathsf{E}\left(\right) \cdot x} - 1\right) \]
      5. log-EN/A

        \[\leadsto \left(c \cdot y\right) \cdot \left(e^{1 \cdot x} - 1\right) \]
      6. *-commutativeN/A

        \[\leadsto \left(c \cdot y\right) \cdot \left(e^{x \cdot 1} - 1\right) \]
      7. lower-expm1.f64N/A

        \[\leadsto \left(c \cdot y\right) \cdot \mathsf{expm1}\left(x \cdot 1\right) \]
      8. lower-*.f6497.2

        \[\leadsto \left(c \cdot y\right) \cdot \mathsf{expm1}\left(x \cdot 1\right) \]
    5. Applied rewrites97.2%

      \[\leadsto \color{blue}{\left(c \cdot y\right) \cdot \mathsf{expm1}\left(x \cdot 1\right)} \]

    if 5.1999999999999998e42 < y

    1. Initial program 20.4%

      \[c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto c \cdot \log \left(1 + \color{blue}{\left(x \cdot \left(\log \mathsf{E}\left(\right) + x \cdot \left(\frac{1}{2} \cdot {\log \mathsf{E}\left(\right)}^{2} + x \cdot \left(\frac{1}{24} \cdot \left(x \cdot {\log \mathsf{E}\left(\right)}^{4}\right) + \frac{1}{6} \cdot {\log \mathsf{E}\left(\right)}^{3}\right)\right)\right)\right)} \cdot y\right) \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto c \cdot \log \left(1 + \left(\left(\log \mathsf{E}\left(\right) + x \cdot \left(\frac{1}{2} \cdot {\log \mathsf{E}\left(\right)}^{2} + x \cdot \left(\frac{1}{24} \cdot \left(x \cdot {\log \mathsf{E}\left(\right)}^{4}\right) + \frac{1}{6} \cdot {\log \mathsf{E}\left(\right)}^{3}\right)\right)\right) \cdot \color{blue}{x}\right) \cdot y\right) \]
      2. lower-*.f64N/A

        \[\leadsto c \cdot \log \left(1 + \left(\left(\log \mathsf{E}\left(\right) + x \cdot \left(\frac{1}{2} \cdot {\log \mathsf{E}\left(\right)}^{2} + x \cdot \left(\frac{1}{24} \cdot \left(x \cdot {\log \mathsf{E}\left(\right)}^{4}\right) + \frac{1}{6} \cdot {\log \mathsf{E}\left(\right)}^{3}\right)\right)\right) \cdot \color{blue}{x}\right) \cdot y\right) \]
    5. Applied rewrites57.4%

      \[\leadsto c \cdot \log \left(1 + \color{blue}{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.041666666666666664 \cdot x, 1, 0.16666666666666666\right), x, 0.5\right), x, 1\right) \cdot x\right)} \cdot y\right) \]
    6. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \color{blue}{\log \left(1 + \left(\left(\left(\left(\left(\frac{1}{24} \cdot x\right) \cdot 1 + \frac{1}{6}\right) \cdot x + \frac{1}{2}\right) \cdot x + 1\right) \cdot x\right) \cdot y\right) \cdot c} \]
      2. lower-*.f64N/A

        \[\leadsto \color{blue}{\log \left(1 + \left(\left(\left(\left(\left(\frac{1}{24} \cdot x\right) \cdot 1 + \frac{1}{6}\right) \cdot x + \frac{1}{2}\right) \cdot x + 1\right) \cdot x\right) \cdot y\right) \cdot c} \]
    7. Applied rewrites95.6%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.041666666666666664, x, 0.16666666666666666\right), x, 0.5\right), x, 1\right) \cdot x\right) \cdot y\right) \cdot c} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification88.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -190:\\ \;\;\;\;\mathsf{log1p}\left(y \cdot x\right) \cdot c\\ \mathbf{elif}\;y \leq 5.2 \cdot 10^{+42}:\\ \;\;\;\;\left(c \cdot y\right) \cdot \mathsf{expm1}\left(x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{log1p}\left(\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.041666666666666664, x, 0.16666666666666666\right), x, 0.5\right), x, 1\right) \cdot x\right) \cdot y\right) \cdot c\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 89.8% accurate, 1.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -190:\\ \;\;\;\;\mathsf{log1p}\left(y \cdot x\right) \cdot c\\ \mathbf{elif}\;y \leq 5.2 \cdot 10^{+42}:\\ \;\;\;\;\left(c \cdot y\right) \cdot \mathsf{expm1}\left(x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{log1p}\left(y \cdot \left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, x, 0.5\right), x, 1\right) \cdot x\right)\right) \cdot c\\ \end{array} \end{array} \]
(FPCore (c x y)
 :precision binary64
 (if (<= y -190.0)
   (* (log1p (* y x)) c)
   (if (<= y 5.2e+42)
     (* (* c y) (expm1 x))
     (* (log1p (* y (* (fma (fma 0.16666666666666666 x 0.5) x 1.0) x))) c))))
double code(double c, double x, double y) {
	double tmp;
	if (y <= -190.0) {
		tmp = log1p((y * x)) * c;
	} else if (y <= 5.2e+42) {
		tmp = (c * y) * expm1(x);
	} else {
		tmp = log1p((y * (fma(fma(0.16666666666666666, x, 0.5), x, 1.0) * x))) * c;
	}
	return tmp;
}
function code(c, x, y)
	tmp = 0.0
	if (y <= -190.0)
		tmp = Float64(log1p(Float64(y * x)) * c);
	elseif (y <= 5.2e+42)
		tmp = Float64(Float64(c * y) * expm1(x));
	else
		tmp = Float64(log1p(Float64(y * Float64(fma(fma(0.16666666666666666, x, 0.5), x, 1.0) * x))) * c);
	end
	return tmp
end
code[c_, x_, y_] := If[LessEqual[y, -190.0], N[(N[Log[1 + N[(y * x), $MachinePrecision]], $MachinePrecision] * c), $MachinePrecision], If[LessEqual[y, 5.2e+42], N[(N[(c * y), $MachinePrecision] * N[(Exp[x] - 1), $MachinePrecision]), $MachinePrecision], N[(N[Log[1 + N[(y * N[(N[(N[(0.16666666666666666 * x + 0.5), $MachinePrecision] * x + 1.0), $MachinePrecision] * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * c), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -190:\\
\;\;\;\;\mathsf{log1p}\left(y \cdot x\right) \cdot c\\

\mathbf{elif}\;y \leq 5.2 \cdot 10^{+42}:\\
\;\;\;\;\left(c \cdot y\right) \cdot \mathsf{expm1}\left(x\right)\\

\mathbf{else}:\\
\;\;\;\;\mathsf{log1p}\left(y \cdot \left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, x, 0.5\right), x, 1\right) \cdot x\right)\right) \cdot c\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y < -190

    1. Initial program 52.6%

      \[c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. *-commutativeN/A

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

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

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

        \[\leadsto \color{blue}{\mathsf{log1p}\left(y \cdot \left({\mathsf{E}\left(\right)}^{x} - 1\right)\right)} \cdot c \]
      5. lower-*.f64N/A

        \[\leadsto \mathsf{log1p}\left(\color{blue}{y \cdot \left({\mathsf{E}\left(\right)}^{x} - 1\right)}\right) \cdot c \]
      6. pow-to-expN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\color{blue}{e^{\log \mathsf{E}\left(\right) \cdot x}} - 1\right)\right) \cdot c \]
      7. log-EN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(e^{\color{blue}{1} \cdot x} - 1\right)\right) \cdot c \]
      8. *-commutativeN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(e^{\color{blue}{x \cdot 1}} - 1\right)\right) \cdot c \]
      9. lower-expm1.f64N/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(x \cdot 1\right)}\right) \cdot c \]
      10. lower-*.f6499.6

        \[\leadsto \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(\color{blue}{x \cdot 1}\right)\right) \cdot c \]
    4. Applied rewrites99.6%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(x \cdot 1\right)\right) \cdot c} \]
    5. Taylor expanded in x around 0

      \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{x}\right) \cdot c \]
    6. Step-by-step derivation
      1. *-commutative61.9

        \[\leadsto \mathsf{log1p}\left(y \cdot x\right) \cdot c \]
      2. log-E61.9

        \[\leadsto \mathsf{log1p}\left(y \cdot x\right) \cdot c \]
      3. pow-to-exp61.9

        \[\leadsto \mathsf{log1p}\left(y \cdot x\right) \cdot c \]
    7. Applied rewrites61.9%

      \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{x}\right) \cdot c \]

    if -190 < y < 5.1999999999999998e42

    1. Initial program 42.2%

      \[c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \]
    2. Add Preprocessing
    3. Taylor expanded in y around 0

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

        \[\leadsto \left(c \cdot y\right) \cdot \color{blue}{\left({\mathsf{E}\left(\right)}^{x} - 1\right)} \]
      2. lower-*.f64N/A

        \[\leadsto \left(c \cdot y\right) \cdot \color{blue}{\left({\mathsf{E}\left(\right)}^{x} - 1\right)} \]
      3. lower-*.f64N/A

        \[\leadsto \left(c \cdot y\right) \cdot \left(\color{blue}{{\mathsf{E}\left(\right)}^{x}} - 1\right) \]
      4. pow-to-expN/A

        \[\leadsto \left(c \cdot y\right) \cdot \left(e^{\log \mathsf{E}\left(\right) \cdot x} - 1\right) \]
      5. log-EN/A

        \[\leadsto \left(c \cdot y\right) \cdot \left(e^{1 \cdot x} - 1\right) \]
      6. *-commutativeN/A

        \[\leadsto \left(c \cdot y\right) \cdot \left(e^{x \cdot 1} - 1\right) \]
      7. lower-expm1.f64N/A

        \[\leadsto \left(c \cdot y\right) \cdot \mathsf{expm1}\left(x \cdot 1\right) \]
      8. lower-*.f6497.2

        \[\leadsto \left(c \cdot y\right) \cdot \mathsf{expm1}\left(x \cdot 1\right) \]
    5. Applied rewrites97.2%

      \[\leadsto \color{blue}{\left(c \cdot y\right) \cdot \mathsf{expm1}\left(x \cdot 1\right)} \]

    if 5.1999999999999998e42 < y

    1. Initial program 20.4%

      \[c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. *-commutativeN/A

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

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

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

        \[\leadsto \color{blue}{\mathsf{log1p}\left(y \cdot \left({\mathsf{E}\left(\right)}^{x} - 1\right)\right)} \cdot c \]
      5. lower-*.f64N/A

        \[\leadsto \mathsf{log1p}\left(\color{blue}{y \cdot \left({\mathsf{E}\left(\right)}^{x} - 1\right)}\right) \cdot c \]
      6. pow-to-expN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\color{blue}{e^{\log \mathsf{E}\left(\right) \cdot x}} - 1\right)\right) \cdot c \]
      7. log-EN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(e^{\color{blue}{1} \cdot x} - 1\right)\right) \cdot c \]
      8. *-commutativeN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(e^{\color{blue}{x \cdot 1}} - 1\right)\right) \cdot c \]
      9. lower-expm1.f64N/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(x \cdot 1\right)}\right) \cdot c \]
      10. lower-*.f6496.4

        \[\leadsto \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(\color{blue}{x \cdot 1}\right)\right) \cdot c \]
    4. Applied rewrites96.4%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(x \cdot 1\right)\right) \cdot c} \]
    5. Taylor expanded in x around 0

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

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(x \cdot \left(1 + x \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot x\right)\right)\right)\right) \cdot c \]
      2. log-EN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(x \cdot \left(1 + x \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot x\right)\right)\right)\right) \cdot c \]
      3. pow-to-expN/A

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

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\left(1 + x \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot x\right)\right) \cdot \color{blue}{x}\right)\right) \cdot c \]
      5. metadata-evalN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\left(1 + x \cdot \left(\frac{1}{2} \cdot 1 + \frac{1}{6} \cdot x\right)\right) \cdot x\right)\right) \cdot c \]
      6. metadata-evalN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\left(1 + x \cdot \left(\frac{1}{2} \cdot {1}^{2} + \frac{1}{6} \cdot x\right)\right) \cdot x\right)\right) \cdot c \]
      7. log-EN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\left(1 + x \cdot \left(\frac{1}{2} \cdot {\log \mathsf{E}\left(\right)}^{2} + \frac{1}{6} \cdot x\right)\right) \cdot x\right)\right) \cdot c \]
      8. *-rgt-identityN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\left(1 + x \cdot \left(\frac{1}{2} \cdot {\log \mathsf{E}\left(\right)}^{2} + \frac{1}{6} \cdot \left(x \cdot 1\right)\right)\right) \cdot x\right)\right) \cdot c \]
      9. metadata-evalN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\left(1 + x \cdot \left(\frac{1}{2} \cdot {\log \mathsf{E}\left(\right)}^{2} + \frac{1}{6} \cdot \left(x \cdot {1}^{3}\right)\right)\right) \cdot x\right)\right) \cdot c \]
      10. log-EN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\left(1 + x \cdot \left(\frac{1}{2} \cdot {\log \mathsf{E}\left(\right)}^{2} + \frac{1}{6} \cdot \left(x \cdot {\log \mathsf{E}\left(\right)}^{3}\right)\right)\right) \cdot x\right)\right) \cdot c \]
      11. +-commutativeN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\left(1 + x \cdot \left(\frac{1}{6} \cdot \left(x \cdot {\log \mathsf{E}\left(\right)}^{3}\right) + \frac{1}{2} \cdot {\log \mathsf{E}\left(\right)}^{2}\right)\right) \cdot x\right)\right) \cdot c \]
      12. log-EN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\left(\log \mathsf{E}\left(\right) + x \cdot \left(\frac{1}{6} \cdot \left(x \cdot {\log \mathsf{E}\left(\right)}^{3}\right) + \frac{1}{2} \cdot {\log \mathsf{E}\left(\right)}^{2}\right)\right) \cdot x\right)\right) \cdot c \]
      13. lower-*.f64N/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\left(\log \mathsf{E}\left(\right) + x \cdot \left(\frac{1}{6} \cdot \left(x \cdot {\log \mathsf{E}\left(\right)}^{3}\right) + \frac{1}{2} \cdot {\log \mathsf{E}\left(\right)}^{2}\right)\right) \cdot \color{blue}{x}\right)\right) \cdot c \]
    7. Applied rewrites95.3%

      \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, x, 0.5\right), x, 1\right) \cdot x\right)}\right) \cdot c \]
  3. Recombined 3 regimes into one program.
  4. Final simplification88.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -190:\\ \;\;\;\;\mathsf{log1p}\left(y \cdot x\right) \cdot c\\ \mathbf{elif}\;y \leq 5.2 \cdot 10^{+42}:\\ \;\;\;\;\left(c \cdot y\right) \cdot \mathsf{expm1}\left(x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{log1p}\left(y \cdot \left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, x, 0.5\right), x, 1\right) \cdot x\right)\right) \cdot c\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 89.8% accurate, 1.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -190:\\ \;\;\;\;\mathsf{log1p}\left(y \cdot x\right) \cdot c\\ \mathbf{elif}\;y \leq 5.2 \cdot 10^{+42}:\\ \;\;\;\;\left(c \cdot y\right) \cdot \mathsf{expm1}\left(x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{log1p}\left(y \cdot \left(\mathsf{fma}\left(0.5, x, 1\right) \cdot x\right)\right) \cdot c\\ \end{array} \end{array} \]
(FPCore (c x y)
 :precision binary64
 (if (<= y -190.0)
   (* (log1p (* y x)) c)
   (if (<= y 5.2e+42)
     (* (* c y) (expm1 x))
     (* (log1p (* y (* (fma 0.5 x 1.0) x))) c))))
double code(double c, double x, double y) {
	double tmp;
	if (y <= -190.0) {
		tmp = log1p((y * x)) * c;
	} else if (y <= 5.2e+42) {
		tmp = (c * y) * expm1(x);
	} else {
		tmp = log1p((y * (fma(0.5, x, 1.0) * x))) * c;
	}
	return tmp;
}
function code(c, x, y)
	tmp = 0.0
	if (y <= -190.0)
		tmp = Float64(log1p(Float64(y * x)) * c);
	elseif (y <= 5.2e+42)
		tmp = Float64(Float64(c * y) * expm1(x));
	else
		tmp = Float64(log1p(Float64(y * Float64(fma(0.5, x, 1.0) * x))) * c);
	end
	return tmp
end
code[c_, x_, y_] := If[LessEqual[y, -190.0], N[(N[Log[1 + N[(y * x), $MachinePrecision]], $MachinePrecision] * c), $MachinePrecision], If[LessEqual[y, 5.2e+42], N[(N[(c * y), $MachinePrecision] * N[(Exp[x] - 1), $MachinePrecision]), $MachinePrecision], N[(N[Log[1 + N[(y * N[(N[(0.5 * x + 1.0), $MachinePrecision] * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * c), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -190:\\
\;\;\;\;\mathsf{log1p}\left(y \cdot x\right) \cdot c\\

\mathbf{elif}\;y \leq 5.2 \cdot 10^{+42}:\\
\;\;\;\;\left(c \cdot y\right) \cdot \mathsf{expm1}\left(x\right)\\

\mathbf{else}:\\
\;\;\;\;\mathsf{log1p}\left(y \cdot \left(\mathsf{fma}\left(0.5, x, 1\right) \cdot x\right)\right) \cdot c\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y < -190

    1. Initial program 52.6%

      \[c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. *-commutativeN/A

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

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

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

        \[\leadsto \color{blue}{\mathsf{log1p}\left(y \cdot \left({\mathsf{E}\left(\right)}^{x} - 1\right)\right)} \cdot c \]
      5. lower-*.f64N/A

        \[\leadsto \mathsf{log1p}\left(\color{blue}{y \cdot \left({\mathsf{E}\left(\right)}^{x} - 1\right)}\right) \cdot c \]
      6. pow-to-expN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\color{blue}{e^{\log \mathsf{E}\left(\right) \cdot x}} - 1\right)\right) \cdot c \]
      7. log-EN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(e^{\color{blue}{1} \cdot x} - 1\right)\right) \cdot c \]
      8. *-commutativeN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(e^{\color{blue}{x \cdot 1}} - 1\right)\right) \cdot c \]
      9. lower-expm1.f64N/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(x \cdot 1\right)}\right) \cdot c \]
      10. lower-*.f6499.6

        \[\leadsto \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(\color{blue}{x \cdot 1}\right)\right) \cdot c \]
    4. Applied rewrites99.6%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(x \cdot 1\right)\right) \cdot c} \]
    5. Taylor expanded in x around 0

      \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{x}\right) \cdot c \]
    6. Step-by-step derivation
      1. *-commutative61.9

        \[\leadsto \mathsf{log1p}\left(y \cdot x\right) \cdot c \]
      2. log-E61.9

        \[\leadsto \mathsf{log1p}\left(y \cdot x\right) \cdot c \]
      3. pow-to-exp61.9

        \[\leadsto \mathsf{log1p}\left(y \cdot x\right) \cdot c \]
    7. Applied rewrites61.9%

      \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{x}\right) \cdot c \]

    if -190 < y < 5.1999999999999998e42

    1. Initial program 42.2%

      \[c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \]
    2. Add Preprocessing
    3. Taylor expanded in y around 0

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

        \[\leadsto \left(c \cdot y\right) \cdot \color{blue}{\left({\mathsf{E}\left(\right)}^{x} - 1\right)} \]
      2. lower-*.f64N/A

        \[\leadsto \left(c \cdot y\right) \cdot \color{blue}{\left({\mathsf{E}\left(\right)}^{x} - 1\right)} \]
      3. lower-*.f64N/A

        \[\leadsto \left(c \cdot y\right) \cdot \left(\color{blue}{{\mathsf{E}\left(\right)}^{x}} - 1\right) \]
      4. pow-to-expN/A

        \[\leadsto \left(c \cdot y\right) \cdot \left(e^{\log \mathsf{E}\left(\right) \cdot x} - 1\right) \]
      5. log-EN/A

        \[\leadsto \left(c \cdot y\right) \cdot \left(e^{1 \cdot x} - 1\right) \]
      6. *-commutativeN/A

        \[\leadsto \left(c \cdot y\right) \cdot \left(e^{x \cdot 1} - 1\right) \]
      7. lower-expm1.f64N/A

        \[\leadsto \left(c \cdot y\right) \cdot \mathsf{expm1}\left(x \cdot 1\right) \]
      8. lower-*.f6497.2

        \[\leadsto \left(c \cdot y\right) \cdot \mathsf{expm1}\left(x \cdot 1\right) \]
    5. Applied rewrites97.2%

      \[\leadsto \color{blue}{\left(c \cdot y\right) \cdot \mathsf{expm1}\left(x \cdot 1\right)} \]

    if 5.1999999999999998e42 < y

    1. Initial program 20.4%

      \[c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. *-commutativeN/A

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

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

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

        \[\leadsto \color{blue}{\mathsf{log1p}\left(y \cdot \left({\mathsf{E}\left(\right)}^{x} - 1\right)\right)} \cdot c \]
      5. lower-*.f64N/A

        \[\leadsto \mathsf{log1p}\left(\color{blue}{y \cdot \left({\mathsf{E}\left(\right)}^{x} - 1\right)}\right) \cdot c \]
      6. pow-to-expN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\color{blue}{e^{\log \mathsf{E}\left(\right) \cdot x}} - 1\right)\right) \cdot c \]
      7. log-EN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(e^{\color{blue}{1} \cdot x} - 1\right)\right) \cdot c \]
      8. *-commutativeN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(e^{\color{blue}{x \cdot 1}} - 1\right)\right) \cdot c \]
      9. lower-expm1.f64N/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(x \cdot 1\right)}\right) \cdot c \]
      10. lower-*.f6496.4

        \[\leadsto \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(\color{blue}{x \cdot 1}\right)\right) \cdot c \]
    4. Applied rewrites96.4%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(x \cdot 1\right)\right) \cdot c} \]
    5. Taylor expanded in x around 0

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

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(x \cdot \left(1 + \frac{1}{2} \cdot x\right)\right)\right) \cdot c \]
      2. log-EN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(x \cdot \left(1 + \frac{1}{2} \cdot x\right)\right)\right) \cdot c \]
      3. pow-to-expN/A

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

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

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\left(1 + \frac{1}{2} \cdot x\right) \cdot \color{blue}{x}\right)\right) \cdot c \]
      6. +-commutativeN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\left(\frac{1}{2} \cdot x + 1\right) \cdot x\right)\right) \cdot c \]
      7. lower-fma.f6495.0

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\mathsf{fma}\left(0.5, x, 1\right) \cdot x\right)\right) \cdot c \]
    7. Applied rewrites95.0%

      \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{\left(\mathsf{fma}\left(0.5, x, 1\right) \cdot x\right)}\right) \cdot c \]
  3. Recombined 3 regimes into one program.
  4. Final simplification88.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -190:\\ \;\;\;\;\mathsf{log1p}\left(y \cdot x\right) \cdot c\\ \mathbf{elif}\;y \leq 5.2 \cdot 10^{+42}:\\ \;\;\;\;\left(c \cdot y\right) \cdot \mathsf{expm1}\left(x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{log1p}\left(y \cdot \left(\mathsf{fma}\left(0.5, x, 1\right) \cdot x\right)\right) \cdot c\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 89.7% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -190 \lor \neg \left(y \leq 5.2 \cdot 10^{+42}\right):\\ \;\;\;\;\mathsf{log1p}\left(y \cdot x\right) \cdot c\\ \mathbf{else}:\\ \;\;\;\;\left(c \cdot y\right) \cdot \mathsf{expm1}\left(x\right)\\ \end{array} \end{array} \]
(FPCore (c x y)
 :precision binary64
 (if (or (<= y -190.0) (not (<= y 5.2e+42)))
   (* (log1p (* y x)) c)
   (* (* c y) (expm1 x))))
double code(double c, double x, double y) {
	double tmp;
	if ((y <= -190.0) || !(y <= 5.2e+42)) {
		tmp = log1p((y * x)) * c;
	} else {
		tmp = (c * y) * expm1(x);
	}
	return tmp;
}
public static double code(double c, double x, double y) {
	double tmp;
	if ((y <= -190.0) || !(y <= 5.2e+42)) {
		tmp = Math.log1p((y * x)) * c;
	} else {
		tmp = (c * y) * Math.expm1(x);
	}
	return tmp;
}
def code(c, x, y):
	tmp = 0
	if (y <= -190.0) or not (y <= 5.2e+42):
		tmp = math.log1p((y * x)) * c
	else:
		tmp = (c * y) * math.expm1(x)
	return tmp
function code(c, x, y)
	tmp = 0.0
	if ((y <= -190.0) || !(y <= 5.2e+42))
		tmp = Float64(log1p(Float64(y * x)) * c);
	else
		tmp = Float64(Float64(c * y) * expm1(x));
	end
	return tmp
end
code[c_, x_, y_] := If[Or[LessEqual[y, -190.0], N[Not[LessEqual[y, 5.2e+42]], $MachinePrecision]], N[(N[Log[1 + N[(y * x), $MachinePrecision]], $MachinePrecision] * c), $MachinePrecision], N[(N[(c * y), $MachinePrecision] * N[(Exp[x] - 1), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -190 \lor \neg \left(y \leq 5.2 \cdot 10^{+42}\right):\\
\;\;\;\;\mathsf{log1p}\left(y \cdot x\right) \cdot c\\

\mathbf{else}:\\
\;\;\;\;\left(c \cdot y\right) \cdot \mathsf{expm1}\left(x\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < -190 or 5.1999999999999998e42 < y

    1. Initial program 41.7%

      \[c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. *-commutativeN/A

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

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

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

        \[\leadsto \color{blue}{\mathsf{log1p}\left(y \cdot \left({\mathsf{E}\left(\right)}^{x} - 1\right)\right)} \cdot c \]
      5. lower-*.f64N/A

        \[\leadsto \mathsf{log1p}\left(\color{blue}{y \cdot \left({\mathsf{E}\left(\right)}^{x} - 1\right)}\right) \cdot c \]
      6. pow-to-expN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\color{blue}{e^{\log \mathsf{E}\left(\right) \cdot x}} - 1\right)\right) \cdot c \]
      7. log-EN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(e^{\color{blue}{1} \cdot x} - 1\right)\right) \cdot c \]
      8. *-commutativeN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(e^{\color{blue}{x \cdot 1}} - 1\right)\right) \cdot c \]
      9. lower-expm1.f64N/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(x \cdot 1\right)}\right) \cdot c \]
      10. lower-*.f6498.5

        \[\leadsto \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(\color{blue}{x \cdot 1}\right)\right) \cdot c \]
    4. Applied rewrites98.5%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(x \cdot 1\right)\right) \cdot c} \]
    5. Taylor expanded in x around 0

      \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{x}\right) \cdot c \]
    6. Step-by-step derivation
      1. *-commutative72.9

        \[\leadsto \mathsf{log1p}\left(y \cdot x\right) \cdot c \]
      2. log-E72.9

        \[\leadsto \mathsf{log1p}\left(y \cdot x\right) \cdot c \]
      3. pow-to-exp72.9

        \[\leadsto \mathsf{log1p}\left(y \cdot x\right) \cdot c \]
    7. Applied rewrites72.9%

      \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{x}\right) \cdot c \]

    if -190 < y < 5.1999999999999998e42

    1. Initial program 42.2%

      \[c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \]
    2. Add Preprocessing
    3. Taylor expanded in y around 0

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

        \[\leadsto \left(c \cdot y\right) \cdot \color{blue}{\left({\mathsf{E}\left(\right)}^{x} - 1\right)} \]
      2. lower-*.f64N/A

        \[\leadsto \left(c \cdot y\right) \cdot \color{blue}{\left({\mathsf{E}\left(\right)}^{x} - 1\right)} \]
      3. lower-*.f64N/A

        \[\leadsto \left(c \cdot y\right) \cdot \left(\color{blue}{{\mathsf{E}\left(\right)}^{x}} - 1\right) \]
      4. pow-to-expN/A

        \[\leadsto \left(c \cdot y\right) \cdot \left(e^{\log \mathsf{E}\left(\right) \cdot x} - 1\right) \]
      5. log-EN/A

        \[\leadsto \left(c \cdot y\right) \cdot \left(e^{1 \cdot x} - 1\right) \]
      6. *-commutativeN/A

        \[\leadsto \left(c \cdot y\right) \cdot \left(e^{x \cdot 1} - 1\right) \]
      7. lower-expm1.f64N/A

        \[\leadsto \left(c \cdot y\right) \cdot \mathsf{expm1}\left(x \cdot 1\right) \]
      8. lower-*.f6497.2

        \[\leadsto \left(c \cdot y\right) \cdot \mathsf{expm1}\left(x \cdot 1\right) \]
    5. Applied rewrites97.2%

      \[\leadsto \color{blue}{\left(c \cdot y\right) \cdot \mathsf{expm1}\left(x \cdot 1\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification88.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -190 \lor \neg \left(y \leq 5.2 \cdot 10^{+42}\right):\\ \;\;\;\;\mathsf{log1p}\left(y \cdot x\right) \cdot c\\ \mathbf{else}:\\ \;\;\;\;\left(c \cdot y\right) \cdot \mathsf{expm1}\left(x\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 76.9% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -4 \cdot 10^{-18}:\\ \;\;\;\;\left(\mathsf{expm1}\left(x\right) \cdot y\right) \cdot c\\ \mathbf{else}:\\ \;\;\;\;\left(\mathsf{fma}\left(0.5 \cdot c, x, c\right) \cdot y\right) \cdot x\\ \end{array} \end{array} \]
(FPCore (c x y)
 :precision binary64
 (if (<= x -4e-18) (* (* (expm1 x) y) c) (* (* (fma (* 0.5 c) x c) y) x)))
double code(double c, double x, double y) {
	double tmp;
	if (x <= -4e-18) {
		tmp = (expm1(x) * y) * c;
	} else {
		tmp = (fma((0.5 * c), x, c) * y) * x;
	}
	return tmp;
}
function code(c, x, y)
	tmp = 0.0
	if (x <= -4e-18)
		tmp = Float64(Float64(expm1(x) * y) * c);
	else
		tmp = Float64(Float64(fma(Float64(0.5 * c), x, c) * y) * x);
	end
	return tmp
end
code[c_, x_, y_] := If[LessEqual[x, -4e-18], N[(N[(N[(Exp[x] - 1), $MachinePrecision] * y), $MachinePrecision] * c), $MachinePrecision], N[(N[(N[(N[(0.5 * c), $MachinePrecision] * x + c), $MachinePrecision] * y), $MachinePrecision] * x), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -4 \cdot 10^{-18}:\\
\;\;\;\;\left(\mathsf{expm1}\left(x\right) \cdot y\right) \cdot c\\

\mathbf{else}:\\
\;\;\;\;\left(\mathsf{fma}\left(0.5 \cdot c, x, c\right) \cdot y\right) \cdot x\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -4.0000000000000003e-18

    1. Initial program 50.2%

      \[c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. *-commutativeN/A

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

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

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

        \[\leadsto \color{blue}{\mathsf{log1p}\left(y \cdot \left({\mathsf{E}\left(\right)}^{x} - 1\right)\right)} \cdot c \]
      5. lower-*.f64N/A

        \[\leadsto \mathsf{log1p}\left(\color{blue}{y \cdot \left({\mathsf{E}\left(\right)}^{x} - 1\right)}\right) \cdot c \]
      6. pow-to-expN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(\color{blue}{e^{\log \mathsf{E}\left(\right) \cdot x}} - 1\right)\right) \cdot c \]
      7. log-EN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(e^{\color{blue}{1} \cdot x} - 1\right)\right) \cdot c \]
      8. *-commutativeN/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \left(e^{\color{blue}{x \cdot 1}} - 1\right)\right) \cdot c \]
      9. lower-expm1.f64N/A

        \[\leadsto \mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(x \cdot 1\right)}\right) \cdot c \]
      10. lower-*.f6499.8

        \[\leadsto \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(\color{blue}{x \cdot 1}\right)\right) \cdot c \]
    4. Applied rewrites99.8%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(x \cdot 1\right)\right) \cdot c} \]
    5. Taylor expanded in y around 0

      \[\leadsto \color{blue}{\left(y \cdot \left(e^{x} - 1\right)\right)} \cdot c \]
    6. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \left(y \cdot \left(e^{x} - 1\right)\right) \cdot c \]
      2. *-commutativeN/A

        \[\leadsto \left(y \cdot \left(e^{x} - 1\right)\right) \cdot c \]
      3. log-EN/A

        \[\leadsto \left(y \cdot \left(e^{x} - 1\right)\right) \cdot c \]
      4. pow-to-expN/A

        \[\leadsto \left(y \cdot \left(e^{x} - 1\right)\right) \cdot c \]
      5. *-commutativeN/A

        \[\leadsto \left(\left(e^{x} - 1\right) \cdot \color{blue}{y}\right) \cdot c \]
      6. *-rgt-identityN/A

        \[\leadsto \left(\left(e^{x \cdot 1} - 1\right) \cdot y\right) \cdot c \]
      7. *-commutativeN/A

        \[\leadsto \left(\left(e^{1 \cdot x} - 1\right) \cdot y\right) \cdot c \]
      8. log-EN/A

        \[\leadsto \left(\left(e^{\log \mathsf{E}\left(\right) \cdot x} - 1\right) \cdot y\right) \cdot c \]
      9. pow-to-expN/A

        \[\leadsto \left(\left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \cdot c \]
      10. lower-*.f64N/A

        \[\leadsto \left(\left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot \color{blue}{y}\right) \cdot c \]
      11. pow-to-expN/A

        \[\leadsto \left(\left(e^{\log \mathsf{E}\left(\right) \cdot x} - 1\right) \cdot y\right) \cdot c \]
      12. log-EN/A

        \[\leadsto \left(\left(e^{1 \cdot x} - 1\right) \cdot y\right) \cdot c \]
      13. *-commutativeN/A

        \[\leadsto \left(\left(e^{x \cdot 1} - 1\right) \cdot y\right) \cdot c \]
      14. *-rgt-identityN/A

        \[\leadsto \left(\left(e^{x} - 1\right) \cdot y\right) \cdot c \]
      15. lower-expm1.f6464.4

        \[\leadsto \left(\mathsf{expm1}\left(x\right) \cdot y\right) \cdot c \]
    7. Applied rewrites64.4%

      \[\leadsto \color{blue}{\left(\mathsf{expm1}\left(x\right) \cdot y\right)} \cdot c \]

    if -4.0000000000000003e-18 < x

    1. Initial program 37.6%

      \[c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{x \cdot \left(\frac{1}{2} \cdot \left(c \cdot \left(x \cdot \left(-1 \cdot \left({y}^{2} \cdot {\log \mathsf{E}\left(\right)}^{2}\right) + y \cdot {\log \mathsf{E}\left(\right)}^{2}\right)\right)\right) + c \cdot \left(y \cdot \log \mathsf{E}\left(\right)\right)\right)} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

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

        \[\leadsto \left(\frac{1}{2} \cdot \left(c \cdot \left(x \cdot \left(-1 \cdot \left({y}^{2} \cdot {\log \mathsf{E}\left(\right)}^{2}\right) + y \cdot {\log \mathsf{E}\left(\right)}^{2}\right)\right)\right) + c \cdot \left(y \cdot \log \mathsf{E}\left(\right)\right)\right) \cdot \color{blue}{x} \]
    5. Applied rewrites76.6%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.5 \cdot c, \mathsf{fma}\left(y, 1, -\left(y \cdot y\right) \cdot 1\right) \cdot x, \left(c \cdot y\right) \cdot 1\right) \cdot x} \]
    6. Taylor expanded in y around 0

      \[\leadsto \left(y \cdot \left(c + \frac{1}{2} \cdot \left(c \cdot x\right)\right)\right) \cdot x \]
    7. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \left(\left(c + \frac{1}{2} \cdot \left(c \cdot x\right)\right) \cdot y\right) \cdot x \]
      2. lower-*.f64N/A

        \[\leadsto \left(\left(c + \frac{1}{2} \cdot \left(c \cdot x\right)\right) \cdot y\right) \cdot x \]
      3. +-commutativeN/A

        \[\leadsto \left(\left(\frac{1}{2} \cdot \left(c \cdot x\right) + c\right) \cdot y\right) \cdot x \]
      4. associate-*r*N/A

        \[\leadsto \left(\left(\left(\frac{1}{2} \cdot c\right) \cdot x + c\right) \cdot y\right) \cdot x \]
      5. lower-fma.f64N/A

        \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2} \cdot c, x, c\right) \cdot y\right) \cdot x \]
      6. lower-*.f6481.1

        \[\leadsto \left(\mathsf{fma}\left(0.5 \cdot c, x, c\right) \cdot y\right) \cdot x \]
    8. Applied rewrites81.1%

      \[\leadsto \left(\mathsf{fma}\left(0.5 \cdot c, x, c\right) \cdot y\right) \cdot x \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 8: 63.3% accurate, 12.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;c \leq 1.56 \cdot 10^{+88}:\\ \;\;\;\;\left(c \cdot y\right) \cdot x\\ \mathbf{else}:\\ \;\;\;\;\left(c \cdot x\right) \cdot y\\ \end{array} \end{array} \]
(FPCore (c x y)
 :precision binary64
 (if (<= c 1.56e+88) (* (* c y) x) (* (* c x) y)))
double code(double c, double x, double y) {
	double tmp;
	if (c <= 1.56e+88) {
		tmp = (c * y) * x;
	} else {
		tmp = (c * 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(c, x, y)
use fmin_fmax_functions
    real(8), intent (in) :: c
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: tmp
    if (c <= 1.56d+88) then
        tmp = (c * y) * x
    else
        tmp = (c * x) * y
    end if
    code = tmp
end function
public static double code(double c, double x, double y) {
	double tmp;
	if (c <= 1.56e+88) {
		tmp = (c * y) * x;
	} else {
		tmp = (c * x) * y;
	}
	return tmp;
}
def code(c, x, y):
	tmp = 0
	if c <= 1.56e+88:
		tmp = (c * y) * x
	else:
		tmp = (c * x) * y
	return tmp
function code(c, x, y)
	tmp = 0.0
	if (c <= 1.56e+88)
		tmp = Float64(Float64(c * y) * x);
	else
		tmp = Float64(Float64(c * x) * y);
	end
	return tmp
end
function tmp_2 = code(c, x, y)
	tmp = 0.0;
	if (c <= 1.56e+88)
		tmp = (c * y) * x;
	else
		tmp = (c * x) * y;
	end
	tmp_2 = tmp;
end
code[c_, x_, y_] := If[LessEqual[c, 1.56e+88], N[(N[(c * y), $MachinePrecision] * x), $MachinePrecision], N[(N[(c * x), $MachinePrecision] * y), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;c \leq 1.56 \cdot 10^{+88}:\\
\;\;\;\;\left(c \cdot y\right) \cdot x\\

\mathbf{else}:\\
\;\;\;\;\left(c \cdot x\right) \cdot y\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if c < 1.56000000000000008e88

    1. Initial program 46.3%

      \[c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{x \cdot \left(\frac{1}{2} \cdot \left(c \cdot \left(x \cdot \left(-1 \cdot \left({y}^{2} \cdot {\log \mathsf{E}\left(\right)}^{2}\right) + y \cdot {\log \mathsf{E}\left(\right)}^{2}\right)\right)\right) + c \cdot \left(y \cdot \log \mathsf{E}\left(\right)\right)\right)} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

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

        \[\leadsto \left(\frac{1}{2} \cdot \left(c \cdot \left(x \cdot \left(-1 \cdot \left({y}^{2} \cdot {\log \mathsf{E}\left(\right)}^{2}\right) + y \cdot {\log \mathsf{E}\left(\right)}^{2}\right)\right)\right) + c \cdot \left(y \cdot \log \mathsf{E}\left(\right)\right)\right) \cdot \color{blue}{x} \]
    5. Applied rewrites51.6%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.5 \cdot c, \mathsf{fma}\left(y, 1, -\left(y \cdot y\right) \cdot 1\right) \cdot x, \left(c \cdot y\right) \cdot 1\right) \cdot x} \]
    6. Taylor expanded in x around 0

      \[\leadsto \left(c \cdot y\right) \cdot x \]
    7. Step-by-step derivation
      1. lower-*.f6457.6

        \[\leadsto \left(c \cdot y\right) \cdot x \]
    8. Applied rewrites57.6%

      \[\leadsto \left(c \cdot y\right) \cdot x \]

    if 1.56000000000000008e88 < c

    1. Initial program 23.5%

      \[c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

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

        \[\leadsto \left(c \cdot x\right) \cdot \color{blue}{\left(y \cdot \log \mathsf{E}\left(\right)\right)} \]
      2. log-EN/A

        \[\leadsto \left(c \cdot x\right) \cdot \left(y \cdot 1\right) \]
      3. lower-*.f64N/A

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

        \[\leadsto \left(c \cdot x\right) \cdot \left(\color{blue}{y} \cdot 1\right) \]
      5. lower-*.f6462.7

        \[\leadsto \left(c \cdot x\right) \cdot \left(y \cdot \color{blue}{1}\right) \]
    5. Applied rewrites62.7%

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

        \[\leadsto \left(c \cdot x\right) \cdot y \]
      2. lower-*.f64N/A

        \[\leadsto \left(c \cdot x\right) \cdot \color{blue}{y} \]
      3. lower-*.f6462.7

        \[\leadsto \left(c \cdot x\right) \cdot y \]
    7. Applied rewrites62.7%

      \[\leadsto \left(c \cdot x\right) \cdot \color{blue}{y} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 9: 61.9% accurate, 19.8× speedup?

\[\begin{array}{l} \\ \left(c \cdot y\right) \cdot x \end{array} \]
(FPCore (c x y) :precision binary64 (* (* c y) x))
double code(double c, double x, double y) {
	return (c * y) * 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(c, x, y)
use fmin_fmax_functions
    real(8), intent (in) :: c
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = (c * y) * x
end function
public static double code(double c, double x, double y) {
	return (c * y) * x;
}
def code(c, x, y):
	return (c * y) * x
function code(c, x, y)
	return Float64(Float64(c * y) * x)
end
function tmp = code(c, x, y)
	tmp = (c * y) * x;
end
code[c_, x_, y_] := N[(N[(c * y), $MachinePrecision] * x), $MachinePrecision]
\begin{array}{l}

\\
\left(c \cdot y\right) \cdot x
\end{array}
Derivation
  1. Initial program 42.0%

    \[c \cdot \log \left(1 + \left({\mathsf{E}\left(\right)}^{x} - 1\right) \cdot y\right) \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0

    \[\leadsto \color{blue}{x \cdot \left(\frac{1}{2} \cdot \left(c \cdot \left(x \cdot \left(-1 \cdot \left({y}^{2} \cdot {\log \mathsf{E}\left(\right)}^{2}\right) + y \cdot {\log \mathsf{E}\left(\right)}^{2}\right)\right)\right) + c \cdot \left(y \cdot \log \mathsf{E}\left(\right)\right)\right)} \]
  4. Step-by-step derivation
    1. *-commutativeN/A

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

      \[\leadsto \left(\frac{1}{2} \cdot \left(c \cdot \left(x \cdot \left(-1 \cdot \left({y}^{2} \cdot {\log \mathsf{E}\left(\right)}^{2}\right) + y \cdot {\log \mathsf{E}\left(\right)}^{2}\right)\right)\right) + c \cdot \left(y \cdot \log \mathsf{E}\left(\right)\right)\right) \cdot \color{blue}{x} \]
  5. Applied rewrites52.1%

    \[\leadsto \color{blue}{\mathsf{fma}\left(0.5 \cdot c, \mathsf{fma}\left(y, 1, -\left(y \cdot y\right) \cdot 1\right) \cdot x, \left(c \cdot y\right) \cdot 1\right) \cdot x} \]
  6. Taylor expanded in x around 0

    \[\leadsto \left(c \cdot y\right) \cdot x \]
  7. Step-by-step derivation
    1. lower-*.f6457.5

      \[\leadsto \left(c \cdot y\right) \cdot x \]
  8. Applied rewrites57.5%

    \[\leadsto \left(c \cdot y\right) \cdot x \]
  9. Add Preprocessing

Developer Target 1: 93.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ c \cdot \mathsf{log1p}\left(\mathsf{expm1}\left(x\right) \cdot y\right) \end{array} \]
(FPCore (c x y) :precision binary64 (* c (log1p (* (expm1 x) y))))
double code(double c, double x, double y) {
	return c * log1p((expm1(x) * y));
}
public static double code(double c, double x, double y) {
	return c * Math.log1p((Math.expm1(x) * y));
}
def code(c, x, y):
	return c * math.log1p((math.expm1(x) * y))
function code(c, x, y)
	return Float64(c * log1p(Float64(expm1(x) * y)))
end
code[c_, x_, y_] := N[(c * N[Log[1 + N[(N[(Exp[x] - 1), $MachinePrecision] * y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
c \cdot \mathsf{log1p}\left(\mathsf{expm1}\left(x\right) \cdot y\right)
\end{array}

Reproduce

?
herbie shell --seed 2025044 
(FPCore (c x y)
  :name "Logarithmic Transform"
  :precision binary64

  :alt
  (* c (log1p (* (expm1 x) y)))

  (* c (log (+ 1.0 (* (- (pow (E) x) 1.0) y)))))