Linear.Projection:perspective from linear-1.19.1.3, B

Percentage Accurate: 76.7% → 99.8%
Time: 7.5s
Alternatives: 6
Speedup: 0.7×

Specification

?
\[\begin{array}{l} \\ \frac{\left(x \cdot 2\right) \cdot y}{x - y} \end{array} \]
(FPCore (x y) :precision binary64 (/ (* (* x 2.0) y) (- x y)))
double code(double x, double y) {
	return ((x * 2.0) * y) / (x - y);
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = ((x * 2.0d0) * y) / (x - y)
end function
public static double code(double x, double y) {
	return ((x * 2.0) * y) / (x - y);
}
def code(x, y):
	return ((x * 2.0) * y) / (x - y)
function code(x, y)
	return Float64(Float64(Float64(x * 2.0) * y) / Float64(x - y))
end
function tmp = code(x, y)
	tmp = ((x * 2.0) * y) / (x - y);
end
code[x_, y_] := N[(N[(N[(x * 2.0), $MachinePrecision] * y), $MachinePrecision] / N[(x - y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\left(x \cdot 2\right) \cdot y}{x - 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 6 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: 76.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{\left(x \cdot 2\right) \cdot y}{x - y} \end{array} \]
(FPCore (x y) :precision binary64 (/ (* (* x 2.0) y) (- x y)))
double code(double x, double y) {
	return ((x * 2.0) * y) / (x - y);
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = ((x * 2.0d0) * y) / (x - y)
end function
public static double code(double x, double y) {
	return ((x * 2.0) * y) / (x - y);
}
def code(x, y):
	return ((x * 2.0) * y) / (x - y)
function code(x, y)
	return Float64(Float64(Float64(x * 2.0) * y) / Float64(x - y))
end
function tmp = code(x, y)
	tmp = ((x * 2.0) * y) / (x - y);
end
code[x_, y_] := N[(N[(N[(x * 2.0), $MachinePrecision] * y), $MachinePrecision] / N[(x - y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\left(x \cdot 2\right) \cdot y}{x - y}
\end{array}

Alternative 1: 99.8% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(2 \cdot x\right) \cdot \frac{y}{x - y}\\ \mathbf{if}\;y \leq -6 \cdot 10^{-28}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y \leq 4.9 \cdot 10^{-11}:\\ \;\;\;\;\left(\frac{-2}{y - x} \cdot x\right) \cdot y\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (* (* 2.0 x) (/ y (- x y)))))
   (if (<= y -6e-28)
     t_0
     (if (<= y 4.9e-11) (* (* (/ -2.0 (- y x)) x) y) t_0))))
double code(double x, double y) {
	double t_0 = (2.0 * x) * (y / (x - y));
	double tmp;
	if (y <= -6e-28) {
		tmp = t_0;
	} else if (y <= 4.9e-11) {
		tmp = ((-2.0 / (y - x)) * x) * y;
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (2.0d0 * x) * (y / (x - y))
    if (y <= (-6d-28)) then
        tmp = t_0
    else if (y <= 4.9d-11) then
        tmp = (((-2.0d0) / (y - x)) * x) * y
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double t_0 = (2.0 * x) * (y / (x - y));
	double tmp;
	if (y <= -6e-28) {
		tmp = t_0;
	} else if (y <= 4.9e-11) {
		tmp = ((-2.0 / (y - x)) * x) * y;
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x, y):
	t_0 = (2.0 * x) * (y / (x - y))
	tmp = 0
	if y <= -6e-28:
		tmp = t_0
	elif y <= 4.9e-11:
		tmp = ((-2.0 / (y - x)) * x) * y
	else:
		tmp = t_0
	return tmp
function code(x, y)
	t_0 = Float64(Float64(2.0 * x) * Float64(y / Float64(x - y)))
	tmp = 0.0
	if (y <= -6e-28)
		tmp = t_0;
	elseif (y <= 4.9e-11)
		tmp = Float64(Float64(Float64(-2.0 / Float64(y - x)) * x) * y);
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x, y)
	t_0 = (2.0 * x) * (y / (x - y));
	tmp = 0.0;
	if (y <= -6e-28)
		tmp = t_0;
	elseif (y <= 4.9e-11)
		tmp = ((-2.0 / (y - x)) * x) * y;
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_, y_] := Block[{t$95$0 = N[(N[(2.0 * x), $MachinePrecision] * N[(y / N[(x - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[y, -6e-28], t$95$0, If[LessEqual[y, 4.9e-11], N[(N[(N[(-2.0 / N[(y - x), $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision] * y), $MachinePrecision], t$95$0]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(2 \cdot x\right) \cdot \frac{y}{x - y}\\
\mathbf{if}\;y \leq -6 \cdot 10^{-28}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;y \leq 4.9 \cdot 10^{-11}:\\
\;\;\;\;\left(\frac{-2}{y - x} \cdot x\right) \cdot y\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < -6.00000000000000005e-28 or 4.8999999999999999e-11 < y

    1. Initial program 78.4%

      \[\frac{\left(x \cdot 2\right) \cdot y}{x - y} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-/.f64N/A

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

        \[\leadsto \frac{\color{blue}{\left(x \cdot 2\right) \cdot y}}{x - y} \]
      3. associate-/l*N/A

        \[\leadsto \color{blue}{\left(x \cdot 2\right) \cdot \frac{y}{x - y}} \]
      4. *-commutativeN/A

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

        \[\leadsto \color{blue}{\frac{y}{x - y} \cdot \left(x \cdot 2\right)} \]
      6. lower-/.f6499.9

        \[\leadsto \color{blue}{\frac{y}{x - y}} \cdot \left(x \cdot 2\right) \]
      7. lift-*.f64N/A

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

        \[\leadsto \frac{y}{x - y} \cdot \color{blue}{\left(2 \cdot x\right)} \]
      9. lower-*.f6499.9

        \[\leadsto \frac{y}{x - y} \cdot \color{blue}{\left(2 \cdot x\right)} \]
    4. Applied rewrites99.9%

      \[\leadsto \color{blue}{\frac{y}{x - y} \cdot \left(2 \cdot x\right)} \]

    if -6.00000000000000005e-28 < y < 4.8999999999999999e-11

    1. Initial program 76.9%

      \[\frac{\left(x \cdot 2\right) \cdot y}{x - y} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-/.f64N/A

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

        \[\leadsto \frac{\color{blue}{\left(x \cdot 2\right) \cdot y}}{x - y} \]
      3. associate-/l*N/A

        \[\leadsto \color{blue}{\left(x \cdot 2\right) \cdot \frac{y}{x - y}} \]
      4. *-commutativeN/A

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

        \[\leadsto \color{blue}{\frac{y}{x - y} \cdot \left(x \cdot 2\right)} \]
      6. lower-/.f6475.7

        \[\leadsto \color{blue}{\frac{y}{x - y}} \cdot \left(x \cdot 2\right) \]
      7. lift-*.f64N/A

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

        \[\leadsto \frac{y}{x - y} \cdot \color{blue}{\left(2 \cdot x\right)} \]
      9. lower-*.f6475.7

        \[\leadsto \frac{y}{x - y} \cdot \color{blue}{\left(2 \cdot x\right)} \]
    4. Applied rewrites75.7%

      \[\leadsto \color{blue}{\frac{y}{x - y} \cdot \left(2 \cdot x\right)} \]
    5. Step-by-step derivation
      1. lift-*.f64N/A

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

        \[\leadsto \color{blue}{\frac{y}{x - y}} \cdot \left(2 \cdot x\right) \]
      3. associate-*l/N/A

        \[\leadsto \color{blue}{\frac{y \cdot \left(2 \cdot x\right)}{x - y}} \]
      4. lift-*.f64N/A

        \[\leadsto \frac{y \cdot \color{blue}{\left(2 \cdot x\right)}}{x - y} \]
      5. *-commutativeN/A

        \[\leadsto \frac{y \cdot \color{blue}{\left(x \cdot 2\right)}}{x - y} \]
      6. associate-*r*N/A

        \[\leadsto \frac{\color{blue}{\left(y \cdot x\right) \cdot 2}}{x - y} \]
      7. lift-*.f64N/A

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

        \[\leadsto \frac{\left(y \cdot x\right) \cdot 2}{\color{blue}{x - y}} \]
      9. sub-negN/A

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

        \[\leadsto \frac{\left(y \cdot x\right) \cdot 2}{\color{blue}{\left(\mathsf{neg}\left(y\right)\right) + x}} \]
      11. remove-double-negN/A

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

        \[\leadsto \frac{\left(y \cdot x\right) \cdot 2}{\color{blue}{\mathsf{neg}\left(\left(y + \left(\mathsf{neg}\left(x\right)\right)\right)\right)}} \]
      13. sub-negN/A

        \[\leadsto \frac{\left(y \cdot x\right) \cdot 2}{\mathsf{neg}\left(\color{blue}{\left(y - x\right)}\right)} \]
      14. lift--.f64N/A

        \[\leadsto \frac{\left(y \cdot x\right) \cdot 2}{\mathsf{neg}\left(\color{blue}{\left(y - x\right)}\right)} \]
      15. associate-*r/N/A

        \[\leadsto \color{blue}{\left(y \cdot x\right) \cdot \frac{2}{\mathsf{neg}\left(\left(y - x\right)\right)}} \]
      16. metadata-evalN/A

        \[\leadsto \left(y \cdot x\right) \cdot \frac{\color{blue}{\mathsf{neg}\left(-2\right)}}{\mathsf{neg}\left(\left(y - x\right)\right)} \]
      17. frac-2negN/A

        \[\leadsto \left(y \cdot x\right) \cdot \color{blue}{\frac{-2}{y - x}} \]
      18. lift-*.f64N/A

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

        \[\leadsto \left(y \cdot x\right) \cdot \color{blue}{\frac{-2}{y - x}} \]
      20. associate-*l*N/A

        \[\leadsto \color{blue}{y \cdot \left(x \cdot \frac{-2}{y - x}\right)} \]
      21. *-commutativeN/A

        \[\leadsto \color{blue}{\left(x \cdot \frac{-2}{y - x}\right) \cdot y} \]
    6. Applied rewrites99.8%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -6 \cdot 10^{-28}:\\ \;\;\;\;\left(2 \cdot x\right) \cdot \frac{y}{x - y}\\ \mathbf{elif}\;y \leq 4.9 \cdot 10^{-11}:\\ \;\;\;\;\left(\frac{-2}{y - x} \cdot x\right) \cdot y\\ \mathbf{else}:\\ \;\;\;\;\left(2 \cdot x\right) \cdot \frac{y}{x - y}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 97.4% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{-2}{y - x}\\ t_1 := \left(t\_0 \cdot x\right) \cdot y\\ t_2 := \frac{\left(2 \cdot x\right) \cdot y}{x - y}\\ t_3 := \left(x \cdot y\right) \cdot t\_0\\ \mathbf{if}\;t\_2 \leq -1.12 \cdot 10^{-27}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;t\_2 \leq -1 \cdot 10^{-280}:\\ \;\;\;\;t\_3\\ \mathbf{elif}\;t\_2 \leq 0:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;t\_2 \leq 5 \cdot 10^{-106}:\\ \;\;\;\;t\_3\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (/ -2.0 (- y x)))
        (t_1 (* (* t_0 x) y))
        (t_2 (/ (* (* 2.0 x) y) (- x y)))
        (t_3 (* (* x y) t_0)))
   (if (<= t_2 -1.12e-27)
     t_1
     (if (<= t_2 -1e-280)
       t_3
       (if (<= t_2 0.0) t_1 (if (<= t_2 5e-106) t_3 t_1))))))
double code(double x, double y) {
	double t_0 = -2.0 / (y - x);
	double t_1 = (t_0 * x) * y;
	double t_2 = ((2.0 * x) * y) / (x - y);
	double t_3 = (x * y) * t_0;
	double tmp;
	if (t_2 <= -1.12e-27) {
		tmp = t_1;
	} else if (t_2 <= -1e-280) {
		tmp = t_3;
	} else if (t_2 <= 0.0) {
		tmp = t_1;
	} else if (t_2 <= 5e-106) {
		tmp = t_3;
	} else {
		tmp = t_1;
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: t_2
    real(8) :: t_3
    real(8) :: tmp
    t_0 = (-2.0d0) / (y - x)
    t_1 = (t_0 * x) * y
    t_2 = ((2.0d0 * x) * y) / (x - y)
    t_3 = (x * y) * t_0
    if (t_2 <= (-1.12d-27)) then
        tmp = t_1
    else if (t_2 <= (-1d-280)) then
        tmp = t_3
    else if (t_2 <= 0.0d0) then
        tmp = t_1
    else if (t_2 <= 5d-106) then
        tmp = t_3
    else
        tmp = t_1
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double t_0 = -2.0 / (y - x);
	double t_1 = (t_0 * x) * y;
	double t_2 = ((2.0 * x) * y) / (x - y);
	double t_3 = (x * y) * t_0;
	double tmp;
	if (t_2 <= -1.12e-27) {
		tmp = t_1;
	} else if (t_2 <= -1e-280) {
		tmp = t_3;
	} else if (t_2 <= 0.0) {
		tmp = t_1;
	} else if (t_2 <= 5e-106) {
		tmp = t_3;
	} else {
		tmp = t_1;
	}
	return tmp;
}
def code(x, y):
	t_0 = -2.0 / (y - x)
	t_1 = (t_0 * x) * y
	t_2 = ((2.0 * x) * y) / (x - y)
	t_3 = (x * y) * t_0
	tmp = 0
	if t_2 <= -1.12e-27:
		tmp = t_1
	elif t_2 <= -1e-280:
		tmp = t_3
	elif t_2 <= 0.0:
		tmp = t_1
	elif t_2 <= 5e-106:
		tmp = t_3
	else:
		tmp = t_1
	return tmp
function code(x, y)
	t_0 = Float64(-2.0 / Float64(y - x))
	t_1 = Float64(Float64(t_0 * x) * y)
	t_2 = Float64(Float64(Float64(2.0 * x) * y) / Float64(x - y))
	t_3 = Float64(Float64(x * y) * t_0)
	tmp = 0.0
	if (t_2 <= -1.12e-27)
		tmp = t_1;
	elseif (t_2 <= -1e-280)
		tmp = t_3;
	elseif (t_2 <= 0.0)
		tmp = t_1;
	elseif (t_2 <= 5e-106)
		tmp = t_3;
	else
		tmp = t_1;
	end
	return tmp
end
function tmp_2 = code(x, y)
	t_0 = -2.0 / (y - x);
	t_1 = (t_0 * x) * y;
	t_2 = ((2.0 * x) * y) / (x - y);
	t_3 = (x * y) * t_0;
	tmp = 0.0;
	if (t_2 <= -1.12e-27)
		tmp = t_1;
	elseif (t_2 <= -1e-280)
		tmp = t_3;
	elseif (t_2 <= 0.0)
		tmp = t_1;
	elseif (t_2 <= 5e-106)
		tmp = t_3;
	else
		tmp = t_1;
	end
	tmp_2 = tmp;
end
code[x_, y_] := Block[{t$95$0 = N[(-2.0 / N[(y - x), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(t$95$0 * x), $MachinePrecision] * y), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(2.0 * x), $MachinePrecision] * y), $MachinePrecision] / N[(x - y), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(N[(x * y), $MachinePrecision] * t$95$0), $MachinePrecision]}, If[LessEqual[t$95$2, -1.12e-27], t$95$1, If[LessEqual[t$95$2, -1e-280], t$95$3, If[LessEqual[t$95$2, 0.0], t$95$1, If[LessEqual[t$95$2, 5e-106], t$95$3, t$95$1]]]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{-2}{y - x}\\
t_1 := \left(t\_0 \cdot x\right) \cdot y\\
t_2 := \frac{\left(2 \cdot x\right) \cdot y}{x - y}\\
t_3 := \left(x \cdot y\right) \cdot t\_0\\
\mathbf{if}\;t\_2 \leq -1.12 \cdot 10^{-27}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;t\_2 \leq -1 \cdot 10^{-280}:\\
\;\;\;\;t\_3\\

\mathbf{elif}\;t\_2 \leq 0:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;t\_2 \leq 5 \cdot 10^{-106}:\\
\;\;\;\;t\_3\\

\mathbf{else}:\\
\;\;\;\;t\_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (*.f64 (*.f64 x #s(literal 2 binary64)) y) (-.f64 x y)) < -1.1199999999999999e-27 or -9.9999999999999996e-281 < (/.f64 (*.f64 (*.f64 x #s(literal 2 binary64)) y) (-.f64 x y)) < 0.0 or 4.99999999999999983e-106 < (/.f64 (*.f64 (*.f64 x #s(literal 2 binary64)) y) (-.f64 x y))

    1. Initial program 55.8%

      \[\frac{\left(x \cdot 2\right) \cdot y}{x - y} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-/.f64N/A

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

        \[\leadsto \frac{\color{blue}{\left(x \cdot 2\right) \cdot y}}{x - y} \]
      3. associate-/l*N/A

        \[\leadsto \color{blue}{\left(x \cdot 2\right) \cdot \frac{y}{x - y}} \]
      4. *-commutativeN/A

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

        \[\leadsto \color{blue}{\frac{y}{x - y} \cdot \left(x \cdot 2\right)} \]
      6. lower-/.f6497.6

        \[\leadsto \color{blue}{\frac{y}{x - y}} \cdot \left(x \cdot 2\right) \]
      7. lift-*.f64N/A

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

        \[\leadsto \frac{y}{x - y} \cdot \color{blue}{\left(2 \cdot x\right)} \]
      9. lower-*.f6497.6

        \[\leadsto \frac{y}{x - y} \cdot \color{blue}{\left(2 \cdot x\right)} \]
    4. Applied rewrites97.6%

      \[\leadsto \color{blue}{\frac{y}{x - y} \cdot \left(2 \cdot x\right)} \]
    5. Step-by-step derivation
      1. lift-*.f64N/A

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

        \[\leadsto \color{blue}{\frac{y}{x - y}} \cdot \left(2 \cdot x\right) \]
      3. associate-*l/N/A

        \[\leadsto \color{blue}{\frac{y \cdot \left(2 \cdot x\right)}{x - y}} \]
      4. lift-*.f64N/A

        \[\leadsto \frac{y \cdot \color{blue}{\left(2 \cdot x\right)}}{x - y} \]
      5. *-commutativeN/A

        \[\leadsto \frac{y \cdot \color{blue}{\left(x \cdot 2\right)}}{x - y} \]
      6. associate-*r*N/A

        \[\leadsto \frac{\color{blue}{\left(y \cdot x\right) \cdot 2}}{x - y} \]
      7. lift-*.f64N/A

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

        \[\leadsto \frac{\left(y \cdot x\right) \cdot 2}{\color{blue}{x - y}} \]
      9. sub-negN/A

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

        \[\leadsto \frac{\left(y \cdot x\right) \cdot 2}{\color{blue}{\left(\mathsf{neg}\left(y\right)\right) + x}} \]
      11. remove-double-negN/A

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

        \[\leadsto \frac{\left(y \cdot x\right) \cdot 2}{\color{blue}{\mathsf{neg}\left(\left(y + \left(\mathsf{neg}\left(x\right)\right)\right)\right)}} \]
      13. sub-negN/A

        \[\leadsto \frac{\left(y \cdot x\right) \cdot 2}{\mathsf{neg}\left(\color{blue}{\left(y - x\right)}\right)} \]
      14. lift--.f64N/A

        \[\leadsto \frac{\left(y \cdot x\right) \cdot 2}{\mathsf{neg}\left(\color{blue}{\left(y - x\right)}\right)} \]
      15. associate-*r/N/A

        \[\leadsto \color{blue}{\left(y \cdot x\right) \cdot \frac{2}{\mathsf{neg}\left(\left(y - x\right)\right)}} \]
      16. metadata-evalN/A

        \[\leadsto \left(y \cdot x\right) \cdot \frac{\color{blue}{\mathsf{neg}\left(-2\right)}}{\mathsf{neg}\left(\left(y - x\right)\right)} \]
      17. frac-2negN/A

        \[\leadsto \left(y \cdot x\right) \cdot \color{blue}{\frac{-2}{y - x}} \]
      18. lift-*.f64N/A

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

        \[\leadsto \left(y \cdot x\right) \cdot \color{blue}{\frac{-2}{y - x}} \]
      20. associate-*l*N/A

        \[\leadsto \color{blue}{y \cdot \left(x \cdot \frac{-2}{y - x}\right)} \]
      21. *-commutativeN/A

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

      \[\leadsto \color{blue}{\left(\frac{-2}{y - x} \cdot x\right) \cdot y} \]

    if -1.1199999999999999e-27 < (/.f64 (*.f64 (*.f64 x #s(literal 2 binary64)) y) (-.f64 x y)) < -9.9999999999999996e-281 or 0.0 < (/.f64 (*.f64 (*.f64 x #s(literal 2 binary64)) y) (-.f64 x y)) < 4.99999999999999983e-106

    1. Initial program 98.7%

      \[\frac{\left(x \cdot 2\right) \cdot y}{x - y} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-/.f64N/A

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

        \[\leadsto \frac{\color{blue}{\left(x \cdot 2\right) \cdot y}}{x - y} \]
      3. *-commutativeN/A

        \[\leadsto \frac{\color{blue}{y \cdot \left(x \cdot 2\right)}}{x - y} \]
      4. lift-*.f64N/A

        \[\leadsto \frac{y \cdot \color{blue}{\left(x \cdot 2\right)}}{x - y} \]
      5. associate-*r*N/A

        \[\leadsto \frac{\color{blue}{\left(y \cdot x\right) \cdot 2}}{x - y} \]
      6. *-commutativeN/A

        \[\leadsto \frac{\color{blue}{\left(x \cdot y\right)} \cdot 2}{x - y} \]
      7. associate-/l*N/A

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

        \[\leadsto \color{blue}{\left(x \cdot y\right) \cdot \frac{2}{x - y}} \]
      9. *-commutativeN/A

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

        \[\leadsto \color{blue}{\left(y \cdot x\right)} \cdot \frac{2}{x - y} \]
      11. frac-2negN/A

        \[\leadsto \left(y \cdot x\right) \cdot \color{blue}{\frac{\mathsf{neg}\left(2\right)}{\mathsf{neg}\left(\left(x - y\right)\right)}} \]
      12. metadata-evalN/A

        \[\leadsto \left(y \cdot x\right) \cdot \frac{\color{blue}{-2}}{\mathsf{neg}\left(\left(x - y\right)\right)} \]
      13. metadata-evalN/A

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

        \[\leadsto \left(y \cdot x\right) \cdot \color{blue}{\frac{\frac{2}{-1}}{\mathsf{neg}\left(\left(x - y\right)\right)}} \]
      15. metadata-evalN/A

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

        \[\leadsto \left(y \cdot x\right) \cdot \frac{-2}{\color{blue}{0 - \left(x - y\right)}} \]
      17. lift--.f64N/A

        \[\leadsto \left(y \cdot x\right) \cdot \frac{-2}{0 - \color{blue}{\left(x - y\right)}} \]
      18. sub-negN/A

        \[\leadsto \left(y \cdot x\right) \cdot \frac{-2}{0 - \color{blue}{\left(x + \left(\mathsf{neg}\left(y\right)\right)\right)}} \]
      19. +-commutativeN/A

        \[\leadsto \left(y \cdot x\right) \cdot \frac{-2}{0 - \color{blue}{\left(\left(\mathsf{neg}\left(y\right)\right) + x\right)}} \]
      20. associate--r+N/A

        \[\leadsto \left(y \cdot x\right) \cdot \frac{-2}{\color{blue}{\left(0 - \left(\mathsf{neg}\left(y\right)\right)\right) - x}} \]
      21. neg-sub0N/A

        \[\leadsto \left(y \cdot x\right) \cdot \frac{-2}{\color{blue}{\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(y\right)\right)\right)\right)} - x} \]
      22. remove-double-negN/A

        \[\leadsto \left(y \cdot x\right) \cdot \frac{-2}{\color{blue}{y} - x} \]
      23. lower--.f6498.4

        \[\leadsto \left(y \cdot x\right) \cdot \frac{-2}{\color{blue}{y - x}} \]
    4. Applied rewrites98.4%

      \[\leadsto \color{blue}{\left(y \cdot x\right) \cdot \frac{-2}{y - x}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\left(2 \cdot x\right) \cdot y}{x - y} \leq -1.12 \cdot 10^{-27}:\\ \;\;\;\;\left(\frac{-2}{y - x} \cdot x\right) \cdot y\\ \mathbf{elif}\;\frac{\left(2 \cdot x\right) \cdot y}{x - y} \leq -1 \cdot 10^{-280}:\\ \;\;\;\;\left(x \cdot y\right) \cdot \frac{-2}{y - x}\\ \mathbf{elif}\;\frac{\left(2 \cdot x\right) \cdot y}{x - y} \leq 0:\\ \;\;\;\;\left(\frac{-2}{y - x} \cdot x\right) \cdot y\\ \mathbf{elif}\;\frac{\left(2 \cdot x\right) \cdot y}{x - y} \leq 5 \cdot 10^{-106}:\\ \;\;\;\;\left(x \cdot y\right) \cdot \frac{-2}{y - x}\\ \mathbf{else}:\\ \;\;\;\;\left(\frac{-2}{y - x} \cdot x\right) \cdot y\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 84.1% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(x \cdot y\right) \cdot \frac{-2}{y - x}\\ t_1 := \frac{\left(2 \cdot x\right) \cdot y}{x - y}\\ \mathbf{if}\;t\_1 \leq -\infty:\\ \;\;\;\;2 \cdot y\\ \mathbf{elif}\;t\_1 \leq -5 \cdot 10^{-295}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_1 \leq 10^{-307}:\\ \;\;\;\;-2 \cdot x\\ \mathbf{elif}\;t\_1 \leq 2 \cdot 10^{+29}:\\ \;\;\;\;t\_0\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{x}{y}, x, x\right) \cdot -2\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (* (* x y) (/ -2.0 (- y x)))) (t_1 (/ (* (* 2.0 x) y) (- x y))))
   (if (<= t_1 (- INFINITY))
     (* 2.0 y)
     (if (<= t_1 -5e-295)
       t_0
       (if (<= t_1 1e-307)
         (* -2.0 x)
         (if (<= t_1 2e+29) t_0 (* (fma (/ x y) x x) -2.0)))))))
double code(double x, double y) {
	double t_0 = (x * y) * (-2.0 / (y - x));
	double t_1 = ((2.0 * x) * y) / (x - y);
	double tmp;
	if (t_1 <= -((double) INFINITY)) {
		tmp = 2.0 * y;
	} else if (t_1 <= -5e-295) {
		tmp = t_0;
	} else if (t_1 <= 1e-307) {
		tmp = -2.0 * x;
	} else if (t_1 <= 2e+29) {
		tmp = t_0;
	} else {
		tmp = fma((x / y), x, x) * -2.0;
	}
	return tmp;
}
function code(x, y)
	t_0 = Float64(Float64(x * y) * Float64(-2.0 / Float64(y - x)))
	t_1 = Float64(Float64(Float64(2.0 * x) * y) / Float64(x - y))
	tmp = 0.0
	if (t_1 <= Float64(-Inf))
		tmp = Float64(2.0 * y);
	elseif (t_1 <= -5e-295)
		tmp = t_0;
	elseif (t_1 <= 1e-307)
		tmp = Float64(-2.0 * x);
	elseif (t_1 <= 2e+29)
		tmp = t_0;
	else
		tmp = Float64(fma(Float64(x / y), x, x) * -2.0);
	end
	return tmp
end
code[x_, y_] := Block[{t$95$0 = N[(N[(x * y), $MachinePrecision] * N[(-2.0 / N[(y - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(2.0 * x), $MachinePrecision] * y), $MachinePrecision] / N[(x - y), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, (-Infinity)], N[(2.0 * y), $MachinePrecision], If[LessEqual[t$95$1, -5e-295], t$95$0, If[LessEqual[t$95$1, 1e-307], N[(-2.0 * x), $MachinePrecision], If[LessEqual[t$95$1, 2e+29], t$95$0, N[(N[(N[(x / y), $MachinePrecision] * x + x), $MachinePrecision] * -2.0), $MachinePrecision]]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(x \cdot y\right) \cdot \frac{-2}{y - x}\\
t_1 := \frac{\left(2 \cdot x\right) \cdot y}{x - y}\\
\mathbf{if}\;t\_1 \leq -\infty:\\
\;\;\;\;2 \cdot y\\

\mathbf{elif}\;t\_1 \leq -5 \cdot 10^{-295}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;t\_1 \leq 10^{-307}:\\
\;\;\;\;-2 \cdot x\\

\mathbf{elif}\;t\_1 \leq 2 \cdot 10^{+29}:\\
\;\;\;\;t\_0\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\frac{x}{y}, x, x\right) \cdot -2\\


\end{array}
\end{array}
Derivation
  1. Split input into 4 regimes
  2. if (/.f64 (*.f64 (*.f64 x #s(literal 2 binary64)) y) (-.f64 x y)) < -inf.0

    1. Initial program 5.1%

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

      \[\leadsto \color{blue}{2 \cdot y} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \color{blue}{y \cdot 2} \]
      2. lower-*.f6457.7

        \[\leadsto \color{blue}{y \cdot 2} \]
    5. Applied rewrites57.7%

      \[\leadsto \color{blue}{y \cdot 2} \]

    if -inf.0 < (/.f64 (*.f64 (*.f64 x #s(literal 2 binary64)) y) (-.f64 x y)) < -5.00000000000000008e-295 or 9.99999999999999909e-308 < (/.f64 (*.f64 (*.f64 x #s(literal 2 binary64)) y) (-.f64 x y)) < 1.99999999999999983e29

    1. Initial program 99.1%

      \[\frac{\left(x \cdot 2\right) \cdot y}{x - y} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-/.f64N/A

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

        \[\leadsto \frac{\color{blue}{\left(x \cdot 2\right) \cdot y}}{x - y} \]
      3. *-commutativeN/A

        \[\leadsto \frac{\color{blue}{y \cdot \left(x \cdot 2\right)}}{x - y} \]
      4. lift-*.f64N/A

        \[\leadsto \frac{y \cdot \color{blue}{\left(x \cdot 2\right)}}{x - y} \]
      5. associate-*r*N/A

        \[\leadsto \frac{\color{blue}{\left(y \cdot x\right) \cdot 2}}{x - y} \]
      6. *-commutativeN/A

        \[\leadsto \frac{\color{blue}{\left(x \cdot y\right)} \cdot 2}{x - y} \]
      7. associate-/l*N/A

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

        \[\leadsto \color{blue}{\left(x \cdot y\right) \cdot \frac{2}{x - y}} \]
      9. *-commutativeN/A

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

        \[\leadsto \color{blue}{\left(y \cdot x\right)} \cdot \frac{2}{x - y} \]
      11. frac-2negN/A

        \[\leadsto \left(y \cdot x\right) \cdot \color{blue}{\frac{\mathsf{neg}\left(2\right)}{\mathsf{neg}\left(\left(x - y\right)\right)}} \]
      12. metadata-evalN/A

        \[\leadsto \left(y \cdot x\right) \cdot \frac{\color{blue}{-2}}{\mathsf{neg}\left(\left(x - y\right)\right)} \]
      13. metadata-evalN/A

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

        \[\leadsto \left(y \cdot x\right) \cdot \color{blue}{\frac{\frac{2}{-1}}{\mathsf{neg}\left(\left(x - y\right)\right)}} \]
      15. metadata-evalN/A

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

        \[\leadsto \left(y \cdot x\right) \cdot \frac{-2}{\color{blue}{0 - \left(x - y\right)}} \]
      17. lift--.f64N/A

        \[\leadsto \left(y \cdot x\right) \cdot \frac{-2}{0 - \color{blue}{\left(x - y\right)}} \]
      18. sub-negN/A

        \[\leadsto \left(y \cdot x\right) \cdot \frac{-2}{0 - \color{blue}{\left(x + \left(\mathsf{neg}\left(y\right)\right)\right)}} \]
      19. +-commutativeN/A

        \[\leadsto \left(y \cdot x\right) \cdot \frac{-2}{0 - \color{blue}{\left(\left(\mathsf{neg}\left(y\right)\right) + x\right)}} \]
      20. associate--r+N/A

        \[\leadsto \left(y \cdot x\right) \cdot \frac{-2}{\color{blue}{\left(0 - \left(\mathsf{neg}\left(y\right)\right)\right) - x}} \]
      21. neg-sub0N/A

        \[\leadsto \left(y \cdot x\right) \cdot \frac{-2}{\color{blue}{\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(y\right)\right)\right)\right)} - x} \]
      22. remove-double-negN/A

        \[\leadsto \left(y \cdot x\right) \cdot \frac{-2}{\color{blue}{y} - x} \]
      23. lower--.f6498.8

        \[\leadsto \left(y \cdot x\right) \cdot \frac{-2}{\color{blue}{y - x}} \]
    4. Applied rewrites98.8%

      \[\leadsto \color{blue}{\left(y \cdot x\right) \cdot \frac{-2}{y - x}} \]

    if -5.00000000000000008e-295 < (/.f64 (*.f64 (*.f64 x #s(literal 2 binary64)) y) (-.f64 x y)) < 9.99999999999999909e-308

    1. Initial program 14.1%

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

      \[\leadsto \color{blue}{-2 \cdot x} \]
    4. Step-by-step derivation
      1. lower-*.f6457.4

        \[\leadsto \color{blue}{-2 \cdot x} \]
    5. Applied rewrites57.4%

      \[\leadsto \color{blue}{-2 \cdot x} \]

    if 1.99999999999999983e29 < (/.f64 (*.f64 (*.f64 x #s(literal 2 binary64)) y) (-.f64 x y))

    1. Initial program 30.3%

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

      \[\leadsto \color{blue}{-2 \cdot x + -2 \cdot \frac{{x}^{2}}{y}} \]
    4. Step-by-step derivation
      1. distribute-lft-outN/A

        \[\leadsto \color{blue}{-2 \cdot \left(x + \frac{{x}^{2}}{y}\right)} \]
      2. *-commutativeN/A

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

        \[\leadsto \color{blue}{\left(x + \frac{{x}^{2}}{y}\right) \cdot -2} \]
      4. +-commutativeN/A

        \[\leadsto \color{blue}{\left(\frac{{x}^{2}}{y} + x\right)} \cdot -2 \]
      5. unpow2N/A

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

        \[\leadsto \left(\color{blue}{x \cdot \frac{x}{y}} + x\right) \cdot -2 \]
      7. *-commutativeN/A

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

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{x}{y}, x, x\right)} \cdot -2 \]
      9. lower-/.f6470.3

        \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{x}{y}}, x, x\right) \cdot -2 \]
    5. Applied rewrites70.3%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{x}{y}, x, x\right) \cdot -2} \]
  3. Recombined 4 regimes into one program.
  4. Final simplification89.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\left(2 \cdot x\right) \cdot y}{x - y} \leq -\infty:\\ \;\;\;\;2 \cdot y\\ \mathbf{elif}\;\frac{\left(2 \cdot x\right) \cdot y}{x - y} \leq -5 \cdot 10^{-295}:\\ \;\;\;\;\left(x \cdot y\right) \cdot \frac{-2}{y - x}\\ \mathbf{elif}\;\frac{\left(2 \cdot x\right) \cdot y}{x - y} \leq 10^{-307}:\\ \;\;\;\;-2 \cdot x\\ \mathbf{elif}\;\frac{\left(2 \cdot x\right) \cdot y}{x - y} \leq 2 \cdot 10^{+29}:\\ \;\;\;\;\left(x \cdot y\right) \cdot \frac{-2}{y - x}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{x}{y}, x, x\right) \cdot -2\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 75.0% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.4 \cdot 10^{-45}:\\ \;\;\;\;2 \cdot y\\ \mathbf{elif}\;x \leq 1.7 \cdot 10^{+27}:\\ \;\;\;\;\mathsf{fma}\left(\frac{x}{y}, x, x\right) \cdot -2\\ \mathbf{else}:\\ \;\;\;\;2 \cdot y\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= x -1.4e-45)
   (* 2.0 y)
   (if (<= x 1.7e+27) (* (fma (/ x y) x x) -2.0) (* 2.0 y))))
double code(double x, double y) {
	double tmp;
	if (x <= -1.4e-45) {
		tmp = 2.0 * y;
	} else if (x <= 1.7e+27) {
		tmp = fma((x / y), x, x) * -2.0;
	} else {
		tmp = 2.0 * y;
	}
	return tmp;
}
function code(x, y)
	tmp = 0.0
	if (x <= -1.4e-45)
		tmp = Float64(2.0 * y);
	elseif (x <= 1.7e+27)
		tmp = Float64(fma(Float64(x / y), x, x) * -2.0);
	else
		tmp = Float64(2.0 * y);
	end
	return tmp
end
code[x_, y_] := If[LessEqual[x, -1.4e-45], N[(2.0 * y), $MachinePrecision], If[LessEqual[x, 1.7e+27], N[(N[(N[(x / y), $MachinePrecision] * x + x), $MachinePrecision] * -2.0), $MachinePrecision], N[(2.0 * y), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.4 \cdot 10^{-45}:\\
\;\;\;\;2 \cdot y\\

\mathbf{elif}\;x \leq 1.7 \cdot 10^{+27}:\\
\;\;\;\;\mathsf{fma}\left(\frac{x}{y}, x, x\right) \cdot -2\\

\mathbf{else}:\\
\;\;\;\;2 \cdot y\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1.4000000000000001e-45 or 1.7e27 < x

    1. Initial program 75.3%

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

      \[\leadsto \color{blue}{2 \cdot y} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \color{blue}{y \cdot 2} \]
      2. lower-*.f6475.4

        \[\leadsto \color{blue}{y \cdot 2} \]
    5. Applied rewrites75.4%

      \[\leadsto \color{blue}{y \cdot 2} \]

    if -1.4000000000000001e-45 < x < 1.7e27

    1. Initial program 80.0%

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

      \[\leadsto \color{blue}{-2 \cdot x + -2 \cdot \frac{{x}^{2}}{y}} \]
    4. Step-by-step derivation
      1. distribute-lft-outN/A

        \[\leadsto \color{blue}{-2 \cdot \left(x + \frac{{x}^{2}}{y}\right)} \]
      2. *-commutativeN/A

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

        \[\leadsto \color{blue}{\left(x + \frac{{x}^{2}}{y}\right) \cdot -2} \]
      4. +-commutativeN/A

        \[\leadsto \color{blue}{\left(\frac{{x}^{2}}{y} + x\right)} \cdot -2 \]
      5. unpow2N/A

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

        \[\leadsto \left(\color{blue}{x \cdot \frac{x}{y}} + x\right) \cdot -2 \]
      7. *-commutativeN/A

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

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{x}{y}, x, x\right)} \cdot -2 \]
      9. lower-/.f6482.2

        \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{x}{y}}, x, x\right) \cdot -2 \]
    5. Applied rewrites82.2%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{x}{y}, x, x\right) \cdot -2} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification78.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.4 \cdot 10^{-45}:\\ \;\;\;\;2 \cdot y\\ \mathbf{elif}\;x \leq 1.7 \cdot 10^{+27}:\\ \;\;\;\;\mathsf{fma}\left(\frac{x}{y}, x, x\right) \cdot -2\\ \mathbf{else}:\\ \;\;\;\;2 \cdot y\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 75.0% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -2 \cdot 10^{-45}:\\ \;\;\;\;2 \cdot y\\ \mathbf{elif}\;x \leq 1.7 \cdot 10^{+27}:\\ \;\;\;\;-2 \cdot x\\ \mathbf{else}:\\ \;\;\;\;2 \cdot y\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= x -2e-45) (* 2.0 y) (if (<= x 1.7e+27) (* -2.0 x) (* 2.0 y))))
double code(double x, double y) {
	double tmp;
	if (x <= -2e-45) {
		tmp = 2.0 * y;
	} else if (x <= 1.7e+27) {
		tmp = -2.0 * x;
	} else {
		tmp = 2.0 * y;
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: tmp
    if (x <= (-2d-45)) then
        tmp = 2.0d0 * y
    else if (x <= 1.7d+27) then
        tmp = (-2.0d0) * x
    else
        tmp = 2.0d0 * y
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double tmp;
	if (x <= -2e-45) {
		tmp = 2.0 * y;
	} else if (x <= 1.7e+27) {
		tmp = -2.0 * x;
	} else {
		tmp = 2.0 * y;
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if x <= -2e-45:
		tmp = 2.0 * y
	elif x <= 1.7e+27:
		tmp = -2.0 * x
	else:
		tmp = 2.0 * y
	return tmp
function code(x, y)
	tmp = 0.0
	if (x <= -2e-45)
		tmp = Float64(2.0 * y);
	elseif (x <= 1.7e+27)
		tmp = Float64(-2.0 * x);
	else
		tmp = Float64(2.0 * y);
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if (x <= -2e-45)
		tmp = 2.0 * y;
	elseif (x <= 1.7e+27)
		tmp = -2.0 * x;
	else
		tmp = 2.0 * y;
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[LessEqual[x, -2e-45], N[(2.0 * y), $MachinePrecision], If[LessEqual[x, 1.7e+27], N[(-2.0 * x), $MachinePrecision], N[(2.0 * y), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -2 \cdot 10^{-45}:\\
\;\;\;\;2 \cdot y\\

\mathbf{elif}\;x \leq 1.7 \cdot 10^{+27}:\\
\;\;\;\;-2 \cdot x\\

\mathbf{else}:\\
\;\;\;\;2 \cdot y\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1.99999999999999997e-45 or 1.7e27 < x

    1. Initial program 75.3%

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

      \[\leadsto \color{blue}{2 \cdot y} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \color{blue}{y \cdot 2} \]
      2. lower-*.f6475.4

        \[\leadsto \color{blue}{y \cdot 2} \]
    5. Applied rewrites75.4%

      \[\leadsto \color{blue}{y \cdot 2} \]

    if -1.99999999999999997e-45 < x < 1.7e27

    1. Initial program 80.0%

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

      \[\leadsto \color{blue}{-2 \cdot x} \]
    4. Step-by-step derivation
      1. lower-*.f6482.2

        \[\leadsto \color{blue}{-2 \cdot x} \]
    5. Applied rewrites82.2%

      \[\leadsto \color{blue}{-2 \cdot x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification78.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -2 \cdot 10^{-45}:\\ \;\;\;\;2 \cdot y\\ \mathbf{elif}\;x \leq 1.7 \cdot 10^{+27}:\\ \;\;\;\;-2 \cdot x\\ \mathbf{else}:\\ \;\;\;\;2 \cdot y\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 50.5% accurate, 4.2× speedup?

\[\begin{array}{l} \\ -2 \cdot x \end{array} \]
(FPCore (x y) :precision binary64 (* -2.0 x))
double code(double x, double y) {
	return -2.0 * x;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = (-2.0d0) * x
end function
public static double code(double x, double y) {
	return -2.0 * x;
}
def code(x, y):
	return -2.0 * x
function code(x, y)
	return Float64(-2.0 * x)
end
function tmp = code(x, y)
	tmp = -2.0 * x;
end
code[x_, y_] := N[(-2.0 * x), $MachinePrecision]
\begin{array}{l}

\\
-2 \cdot x
\end{array}
Derivation
  1. Initial program 77.7%

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

    \[\leadsto \color{blue}{-2 \cdot x} \]
  4. Step-by-step derivation
    1. lower-*.f6454.8

      \[\leadsto \color{blue}{-2 \cdot x} \]
  5. Applied rewrites54.8%

    \[\leadsto \color{blue}{-2 \cdot x} \]
  6. Add Preprocessing

Developer Target 1: 99.4% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{2 \cdot x}{x - y} \cdot y\\ \mathbf{if}\;x < -1.7210442634149447 \cdot 10^{+81}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x < 83645045635564430:\\ \;\;\;\;\frac{x \cdot 2}{\frac{x - y}{y}}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (* (/ (* 2.0 x) (- x y)) y)))
   (if (< x -1.7210442634149447e+81)
     t_0
     (if (< x 83645045635564430.0) (/ (* x 2.0) (/ (- x y) y)) t_0))))
double code(double x, double y) {
	double t_0 = ((2.0 * x) / (x - y)) * y;
	double tmp;
	if (x < -1.7210442634149447e+81) {
		tmp = t_0;
	} else if (x < 83645045635564430.0) {
		tmp = (x * 2.0) / ((x - y) / y);
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    real(8) :: tmp
    t_0 = ((2.0d0 * x) / (x - y)) * y
    if (x < (-1.7210442634149447d+81)) then
        tmp = t_0
    else if (x < 83645045635564430.0d0) then
        tmp = (x * 2.0d0) / ((x - y) / y)
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double t_0 = ((2.0 * x) / (x - y)) * y;
	double tmp;
	if (x < -1.7210442634149447e+81) {
		tmp = t_0;
	} else if (x < 83645045635564430.0) {
		tmp = (x * 2.0) / ((x - y) / y);
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x, y):
	t_0 = ((2.0 * x) / (x - y)) * y
	tmp = 0
	if x < -1.7210442634149447e+81:
		tmp = t_0
	elif x < 83645045635564430.0:
		tmp = (x * 2.0) / ((x - y) / y)
	else:
		tmp = t_0
	return tmp
function code(x, y)
	t_0 = Float64(Float64(Float64(2.0 * x) / Float64(x - y)) * y)
	tmp = 0.0
	if (x < -1.7210442634149447e+81)
		tmp = t_0;
	elseif (x < 83645045635564430.0)
		tmp = Float64(Float64(x * 2.0) / Float64(Float64(x - y) / y));
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x, y)
	t_0 = ((2.0 * x) / (x - y)) * y;
	tmp = 0.0;
	if (x < -1.7210442634149447e+81)
		tmp = t_0;
	elseif (x < 83645045635564430.0)
		tmp = (x * 2.0) / ((x - y) / y);
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_, y_] := Block[{t$95$0 = N[(N[(N[(2.0 * x), $MachinePrecision] / N[(x - y), $MachinePrecision]), $MachinePrecision] * y), $MachinePrecision]}, If[Less[x, -1.7210442634149447e+81], t$95$0, If[Less[x, 83645045635564430.0], N[(N[(x * 2.0), $MachinePrecision] / N[(N[(x - y), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision], t$95$0]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{2 \cdot x}{x - y} \cdot y\\
\mathbf{if}\;x < -1.7210442634149447 \cdot 10^{+81}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;x < 83645045635564430:\\
\;\;\;\;\frac{x \cdot 2}{\frac{x - y}{y}}\\

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


\end{array}
\end{array}

Reproduce

?
herbie shell --seed 2024277 
(FPCore (x y)
  :name "Linear.Projection:perspective from linear-1.19.1.3, B"
  :precision binary64

  :alt
  (! :herbie-platform default (if (< x -1721044263414944700000000000000000000000000000000000000000000000000000000000000000) (* (/ (* 2 x) (- x y)) y) (if (< x 83645045635564430) (/ (* x 2) (/ (- x y) y)) (* (/ (* 2 x) (- x y)) y))))

  (/ (* (* x 2.0) y) (- x y)))