Numeric.SpecFunctions:logGamma from math-functions-0.1.5.2, A

Percentage Accurate: 100.0% → 100.0%
Time: 4.1s
Alternatives: 8
Speedup: 1.2×

Specification

?
\[\begin{array}{l} \\ \left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \end{array} \]
(FPCore (x y)
 :precision binary64
 (+ (- (* x (- y 1.0)) (* y 0.5)) 0.918938533204673))
double code(double x, double y) {
	return ((x * (y - 1.0)) - (y * 0.5)) + 0.918938533204673;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = ((x * (y - 1.0d0)) - (y * 0.5d0)) + 0.918938533204673d0
end function
public static double code(double x, double y) {
	return ((x * (y - 1.0)) - (y * 0.5)) + 0.918938533204673;
}
def code(x, y):
	return ((x * (y - 1.0)) - (y * 0.5)) + 0.918938533204673
function code(x, y)
	return Float64(Float64(Float64(x * Float64(y - 1.0)) - Float64(y * 0.5)) + 0.918938533204673)
end
function tmp = code(x, y)
	tmp = ((x * (y - 1.0)) - (y * 0.5)) + 0.918938533204673;
end
code[x_, y_] := N[(N[(N[(x * N[(y - 1.0), $MachinePrecision]), $MachinePrecision] - N[(y * 0.5), $MachinePrecision]), $MachinePrecision] + 0.918938533204673), $MachinePrecision]
\begin{array}{l}

\\
\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673
\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 8 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: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \end{array} \]
(FPCore (x y)
 :precision binary64
 (+ (- (* x (- y 1.0)) (* y 0.5)) 0.918938533204673))
double code(double x, double y) {
	return ((x * (y - 1.0)) - (y * 0.5)) + 0.918938533204673;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = ((x * (y - 1.0d0)) - (y * 0.5d0)) + 0.918938533204673d0
end function
public static double code(double x, double y) {
	return ((x * (y - 1.0)) - (y * 0.5)) + 0.918938533204673;
}
def code(x, y):
	return ((x * (y - 1.0)) - (y * 0.5)) + 0.918938533204673
function code(x, y)
	return Float64(Float64(Float64(x * Float64(y - 1.0)) - Float64(y * 0.5)) + 0.918938533204673)
end
function tmp = code(x, y)
	tmp = ((x * (y - 1.0)) - (y * 0.5)) + 0.918938533204673;
end
code[x_, y_] := N[(N[(N[(x * N[(y - 1.0), $MachinePrecision]), $MachinePrecision] - N[(y * 0.5), $MachinePrecision]), $MachinePrecision] + 0.918938533204673), $MachinePrecision]
\begin{array}{l}

\\
\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673
\end{array}

Alternative 1: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(x \cdot \left(y + -1\right) - y \cdot 0.5\right) + 0.918938533204673 \end{array} \]
(FPCore (x y)
 :precision binary64
 (+ (- (* x (+ y -1.0)) (* y 0.5)) 0.918938533204673))
double code(double x, double y) {
	return ((x * (y + -1.0)) - (y * 0.5)) + 0.918938533204673;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = ((x * (y + (-1.0d0))) - (y * 0.5d0)) + 0.918938533204673d0
end function
public static double code(double x, double y) {
	return ((x * (y + -1.0)) - (y * 0.5)) + 0.918938533204673;
}
def code(x, y):
	return ((x * (y + -1.0)) - (y * 0.5)) + 0.918938533204673
function code(x, y)
	return Float64(Float64(Float64(x * Float64(y + -1.0)) - Float64(y * 0.5)) + 0.918938533204673)
end
function tmp = code(x, y)
	tmp = ((x * (y + -1.0)) - (y * 0.5)) + 0.918938533204673;
end
code[x_, y_] := N[(N[(N[(x * N[(y + -1.0), $MachinePrecision]), $MachinePrecision] - N[(y * 0.5), $MachinePrecision]), $MachinePrecision] + 0.918938533204673), $MachinePrecision]
\begin{array}{l}

\\
\left(x \cdot \left(y + -1\right) - y \cdot 0.5\right) + 0.918938533204673
\end{array}
Derivation
  1. Initial program 100.0%

    \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
  2. Final simplification100.0%

    \[\leadsto \left(x \cdot \left(y + -1\right) - y \cdot 0.5\right) + 0.918938533204673 \]

Alternative 2: 98.4% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -2.3 \cdot 10^{+18}:\\ \;\;\;\;x \cdot \left(y + -1\right)\\ \mathbf{elif}\;x \leq 118000000:\\ \;\;\;\;x \cdot y + \left(0.918938533204673 - y \cdot 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot y - x\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= x -2.3e+18)
   (* x (+ y -1.0))
   (if (<= x 118000000.0)
     (+ (* x y) (- 0.918938533204673 (* y 0.5)))
     (- (* x y) x))))
double code(double x, double y) {
	double tmp;
	if (x <= -2.3e+18) {
		tmp = x * (y + -1.0);
	} else if (x <= 118000000.0) {
		tmp = (x * y) + (0.918938533204673 - (y * 0.5));
	} else {
		tmp = (x * y) - x;
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: tmp
    if (x <= (-2.3d+18)) then
        tmp = x * (y + (-1.0d0))
    else if (x <= 118000000.0d0) then
        tmp = (x * y) + (0.918938533204673d0 - (y * 0.5d0))
    else
        tmp = (x * y) - x
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double tmp;
	if (x <= -2.3e+18) {
		tmp = x * (y + -1.0);
	} else if (x <= 118000000.0) {
		tmp = (x * y) + (0.918938533204673 - (y * 0.5));
	} else {
		tmp = (x * y) - x;
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if x <= -2.3e+18:
		tmp = x * (y + -1.0)
	elif x <= 118000000.0:
		tmp = (x * y) + (0.918938533204673 - (y * 0.5))
	else:
		tmp = (x * y) - x
	return tmp
function code(x, y)
	tmp = 0.0
	if (x <= -2.3e+18)
		tmp = Float64(x * Float64(y + -1.0));
	elseif (x <= 118000000.0)
		tmp = Float64(Float64(x * y) + Float64(0.918938533204673 - Float64(y * 0.5)));
	else
		tmp = Float64(Float64(x * y) - x);
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if (x <= -2.3e+18)
		tmp = x * (y + -1.0);
	elseif (x <= 118000000.0)
		tmp = (x * y) + (0.918938533204673 - (y * 0.5));
	else
		tmp = (x * y) - x;
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[LessEqual[x, -2.3e+18], N[(x * N[(y + -1.0), $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 118000000.0], N[(N[(x * y), $MachinePrecision] + N[(0.918938533204673 - N[(y * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(x * y), $MachinePrecision] - x), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -2.3 \cdot 10^{+18}:\\
\;\;\;\;x \cdot \left(y + -1\right)\\

\mathbf{elif}\;x \leq 118000000:\\
\;\;\;\;x \cdot y + \left(0.918938533204673 - y \cdot 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;x \cdot y - x\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -2.3e18

    1. Initial program 100.0%

      \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
    2. Step-by-step derivation
      1. cancel-sign-sub-inv100.0%

        \[\leadsto \color{blue}{\left(x \cdot \left(y - 1\right) + \left(-y\right) \cdot 0.5\right)} + 0.918938533204673 \]
      2. +-commutative100.0%

        \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot \left(y - 1\right)\right)} + 0.918938533204673 \]
      3. distribute-lft-out--99.9%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y - x \cdot 1\right)}\right) + 0.918938533204673 \]
      4. cancel-sign-sub-inv99.9%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y + \left(-x\right) \cdot 1\right)}\right) + 0.918938533204673 \]
      5. *-rgt-identity99.9%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \left(x \cdot y + \color{blue}{\left(-x\right)}\right)\right) + 0.918938533204673 \]
      6. associate-+r+99.9%

        \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(-x\right)\right)} + 0.918938533204673 \]
      7. associate-+l+99.9%

        \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(\left(-x\right) + 0.918938533204673\right)} \]
      8. +-commutative99.9%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 + \left(-x\right)\right)} \]
      9. unsub-neg99.9%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 - x\right)} \]
      10. associate-+r-99.9%

        \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + 0.918938533204673\right) - x} \]
      11. *-commutative99.9%

        \[\leadsto \left(\left(\left(-y\right) \cdot 0.5 + \color{blue}{y \cdot x}\right) + 0.918938533204673\right) - x \]
      12. distribute-lft-neg-out99.9%

        \[\leadsto \left(\left(\color{blue}{\left(-y \cdot 0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
      13. distribute-rgt-neg-in99.9%

        \[\leadsto \left(\left(\color{blue}{y \cdot \left(-0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
      14. distribute-lft-out99.9%

        \[\leadsto \left(\color{blue}{y \cdot \left(\left(-0.5\right) + x\right)} + 0.918938533204673\right) - x \]
      15. fma-def99.9%

        \[\leadsto \color{blue}{\mathsf{fma}\left(y, \left(-0.5\right) + x, 0.918938533204673\right)} - x \]
      16. +-commutative99.9%

        \[\leadsto \mathsf{fma}\left(y, \color{blue}{x + \left(-0.5\right)}, 0.918938533204673\right) - x \]
      17. sub-neg99.9%

        \[\leadsto \mathsf{fma}\left(y, \color{blue}{x - 0.5}, 0.918938533204673\right) - x \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\mathsf{fma}\left(y, x - 0.5, 0.918938533204673\right) - x} \]
    4. Step-by-step derivation
      1. fma-udef99.9%

        \[\leadsto \color{blue}{\left(y \cdot \left(x - 0.5\right) + 0.918938533204673\right)} - x \]
      2. *-un-lft-identity99.9%

        \[\leadsto \left(y \cdot \color{blue}{\left(1 \cdot \left(x - 0.5\right)\right)} + 0.918938533204673\right) - x \]
      3. *-un-lft-identity99.9%

        \[\leadsto \left(y \cdot \color{blue}{\left(x - 0.5\right)} + 0.918938533204673\right) - x \]
      4. sub-neg99.9%

        \[\leadsto \left(y \cdot \color{blue}{\left(x + \left(-0.5\right)\right)} + 0.918938533204673\right) - x \]
      5. metadata-eval99.9%

        \[\leadsto \left(y \cdot \left(x + \color{blue}{-0.5}\right) + 0.918938533204673\right) - x \]
    5. Applied egg-rr99.9%

      \[\leadsto \color{blue}{\left(y \cdot \left(x + -0.5\right) + 0.918938533204673\right)} - x \]
    6. Taylor expanded in x around inf 100.0%

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

    if -2.3e18 < x < 1.18e8

    1. Initial program 100.0%

      \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
    2. Step-by-step derivation
      1. associate-+l-100.0%

        \[\leadsto \color{blue}{x \cdot \left(y - 1\right) - \left(y \cdot 0.5 - 0.918938533204673\right)} \]
      2. sub-neg100.0%

        \[\leadsto x \cdot \color{blue}{\left(y + \left(-1\right)\right)} - \left(y \cdot 0.5 - 0.918938533204673\right) \]
      3. metadata-eval100.0%

        \[\leadsto x \cdot \left(y + \color{blue}{-1}\right) - \left(y \cdot 0.5 - 0.918938533204673\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{x \cdot \left(y + -1\right) - \left(y \cdot 0.5 - 0.918938533204673\right)} \]
    4. Taylor expanded in y around inf 98.0%

      \[\leadsto \color{blue}{x \cdot y} - \left(y \cdot 0.5 - 0.918938533204673\right) \]

    if 1.18e8 < x

    1. Initial program 99.9%

      \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
    2. Step-by-step derivation
      1. cancel-sign-sub-inv99.9%

        \[\leadsto \color{blue}{\left(x \cdot \left(y - 1\right) + \left(-y\right) \cdot 0.5\right)} + 0.918938533204673 \]
      2. +-commutative99.9%

        \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot \left(y - 1\right)\right)} + 0.918938533204673 \]
      3. distribute-lft-out--100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y - x \cdot 1\right)}\right) + 0.918938533204673 \]
      4. cancel-sign-sub-inv100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y + \left(-x\right) \cdot 1\right)}\right) + 0.918938533204673 \]
      5. *-rgt-identity100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \left(x \cdot y + \color{blue}{\left(-x\right)}\right)\right) + 0.918938533204673 \]
      6. associate-+r+100.0%

        \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(-x\right)\right)} + 0.918938533204673 \]
      7. associate-+l+100.0%

        \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(\left(-x\right) + 0.918938533204673\right)} \]
      8. +-commutative100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 + \left(-x\right)\right)} \]
      9. unsub-neg100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 - x\right)} \]
      10. associate-+r-100.0%

        \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + 0.918938533204673\right) - x} \]
      11. *-commutative100.0%

        \[\leadsto \left(\left(\left(-y\right) \cdot 0.5 + \color{blue}{y \cdot x}\right) + 0.918938533204673\right) - x \]
      12. distribute-lft-neg-out100.0%

        \[\leadsto \left(\left(\color{blue}{\left(-y \cdot 0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
      13. distribute-rgt-neg-in100.0%

        \[\leadsto \left(\left(\color{blue}{y \cdot \left(-0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
      14. distribute-lft-out100.0%

        \[\leadsto \left(\color{blue}{y \cdot \left(\left(-0.5\right) + x\right)} + 0.918938533204673\right) - x \]
      15. fma-def100.0%

        \[\leadsto \color{blue}{\mathsf{fma}\left(y, \left(-0.5\right) + x, 0.918938533204673\right)} - x \]
      16. +-commutative100.0%

        \[\leadsto \mathsf{fma}\left(y, \color{blue}{x + \left(-0.5\right)}, 0.918938533204673\right) - x \]
      17. sub-neg100.0%

        \[\leadsto \mathsf{fma}\left(y, \color{blue}{x - 0.5}, 0.918938533204673\right) - x \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(y, x - 0.5, 0.918938533204673\right) - x} \]
    4. Step-by-step derivation
      1. fma-udef100.0%

        \[\leadsto \color{blue}{\left(y \cdot \left(x - 0.5\right) + 0.918938533204673\right)} - x \]
      2. *-un-lft-identity100.0%

        \[\leadsto \left(y \cdot \color{blue}{\left(1 \cdot \left(x - 0.5\right)\right)} + 0.918938533204673\right) - x \]
      3. *-un-lft-identity100.0%

        \[\leadsto \left(y \cdot \color{blue}{\left(x - 0.5\right)} + 0.918938533204673\right) - x \]
      4. sub-neg100.0%

        \[\leadsto \left(y \cdot \color{blue}{\left(x + \left(-0.5\right)\right)} + 0.918938533204673\right) - x \]
      5. metadata-eval100.0%

        \[\leadsto \left(y \cdot \left(x + \color{blue}{-0.5}\right) + 0.918938533204673\right) - x \]
    5. Applied egg-rr100.0%

      \[\leadsto \color{blue}{\left(y \cdot \left(x + -0.5\right) + 0.918938533204673\right)} - x \]
    6. Taylor expanded in x around inf 99.3%

      \[\leadsto \color{blue}{x \cdot \left(y - 1\right)} \]
    7. Step-by-step derivation
      1. sub-neg99.3%

        \[\leadsto x \cdot \color{blue}{\left(y + \left(-1\right)\right)} \]
      2. metadata-eval99.3%

        \[\leadsto x \cdot \left(y + \color{blue}{-1}\right) \]
      3. distribute-rgt-in99.3%

        \[\leadsto \color{blue}{y \cdot x + -1 \cdot x} \]
      4. neg-mul-199.3%

        \[\leadsto y \cdot x + \color{blue}{\left(-x\right)} \]
      5. sub-neg99.3%

        \[\leadsto \color{blue}{y \cdot x - x} \]
    8. Simplified99.3%

      \[\leadsto \color{blue}{y \cdot x - x} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification98.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -2.3 \cdot 10^{+18}:\\ \;\;\;\;x \cdot \left(y + -1\right)\\ \mathbf{elif}\;x \leq 118000000:\\ \;\;\;\;x \cdot y + \left(0.918938533204673 - y \cdot 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot y - x\\ \end{array} \]

Alternative 3: 74.2% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1700000 \lor \neg \left(x \leq 10400\right):\\ \;\;\;\;x \cdot \left(y + -1\right)\\ \mathbf{else}:\\ \;\;\;\;0.918938533204673 - x\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (or (<= x -1700000.0) (not (<= x 10400.0)))
   (* x (+ y -1.0))
   (- 0.918938533204673 x)))
double code(double x, double y) {
	double tmp;
	if ((x <= -1700000.0) || !(x <= 10400.0)) {
		tmp = x * (y + -1.0);
	} else {
		tmp = 0.918938533204673 - x;
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: tmp
    if ((x <= (-1700000.0d0)) .or. (.not. (x <= 10400.0d0))) then
        tmp = x * (y + (-1.0d0))
    else
        tmp = 0.918938533204673d0 - x
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double tmp;
	if ((x <= -1700000.0) || !(x <= 10400.0)) {
		tmp = x * (y + -1.0);
	} else {
		tmp = 0.918938533204673 - x;
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if (x <= -1700000.0) or not (x <= 10400.0):
		tmp = x * (y + -1.0)
	else:
		tmp = 0.918938533204673 - x
	return tmp
function code(x, y)
	tmp = 0.0
	if ((x <= -1700000.0) || !(x <= 10400.0))
		tmp = Float64(x * Float64(y + -1.0));
	else
		tmp = Float64(0.918938533204673 - x);
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if ((x <= -1700000.0) || ~((x <= 10400.0)))
		tmp = x * (y + -1.0);
	else
		tmp = 0.918938533204673 - x;
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[Or[LessEqual[x, -1700000.0], N[Not[LessEqual[x, 10400.0]], $MachinePrecision]], N[(x * N[(y + -1.0), $MachinePrecision]), $MachinePrecision], N[(0.918938533204673 - x), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1700000 \lor \neg \left(x \leq 10400\right):\\
\;\;\;\;x \cdot \left(y + -1\right)\\

\mathbf{else}:\\
\;\;\;\;0.918938533204673 - x\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1.7e6 or 10400 < x

    1. Initial program 100.0%

      \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
    2. Step-by-step derivation
      1. cancel-sign-sub-inv100.0%

        \[\leadsto \color{blue}{\left(x \cdot \left(y - 1\right) + \left(-y\right) \cdot 0.5\right)} + 0.918938533204673 \]
      2. +-commutative100.0%

        \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot \left(y - 1\right)\right)} + 0.918938533204673 \]
      3. distribute-lft-out--100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y - x \cdot 1\right)}\right) + 0.918938533204673 \]
      4. cancel-sign-sub-inv100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y + \left(-x\right) \cdot 1\right)}\right) + 0.918938533204673 \]
      5. *-rgt-identity100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \left(x \cdot y + \color{blue}{\left(-x\right)}\right)\right) + 0.918938533204673 \]
      6. associate-+r+100.0%

        \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(-x\right)\right)} + 0.918938533204673 \]
      7. associate-+l+100.0%

        \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(\left(-x\right) + 0.918938533204673\right)} \]
      8. +-commutative100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 + \left(-x\right)\right)} \]
      9. unsub-neg100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 - x\right)} \]
      10. associate-+r-100.0%

        \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + 0.918938533204673\right) - x} \]
      11. *-commutative100.0%

        \[\leadsto \left(\left(\left(-y\right) \cdot 0.5 + \color{blue}{y \cdot x}\right) + 0.918938533204673\right) - x \]
      12. distribute-lft-neg-out100.0%

        \[\leadsto \left(\left(\color{blue}{\left(-y \cdot 0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
      13. distribute-rgt-neg-in100.0%

        \[\leadsto \left(\left(\color{blue}{y \cdot \left(-0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
      14. distribute-lft-out100.0%

        \[\leadsto \left(\color{blue}{y \cdot \left(\left(-0.5\right) + x\right)} + 0.918938533204673\right) - x \]
      15. fma-def100.0%

        \[\leadsto \color{blue}{\mathsf{fma}\left(y, \left(-0.5\right) + x, 0.918938533204673\right)} - x \]
      16. +-commutative100.0%

        \[\leadsto \mathsf{fma}\left(y, \color{blue}{x + \left(-0.5\right)}, 0.918938533204673\right) - x \]
      17. sub-neg100.0%

        \[\leadsto \mathsf{fma}\left(y, \color{blue}{x - 0.5}, 0.918938533204673\right) - x \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(y, x - 0.5, 0.918938533204673\right) - x} \]
    4. Step-by-step derivation
      1. fma-udef100.0%

        \[\leadsto \color{blue}{\left(y \cdot \left(x - 0.5\right) + 0.918938533204673\right)} - x \]
      2. *-un-lft-identity100.0%

        \[\leadsto \left(y \cdot \color{blue}{\left(1 \cdot \left(x - 0.5\right)\right)} + 0.918938533204673\right) - x \]
      3. *-un-lft-identity100.0%

        \[\leadsto \left(y \cdot \color{blue}{\left(x - 0.5\right)} + 0.918938533204673\right) - x \]
      4. sub-neg100.0%

        \[\leadsto \left(y \cdot \color{blue}{\left(x + \left(-0.5\right)\right)} + 0.918938533204673\right) - x \]
      5. metadata-eval100.0%

        \[\leadsto \left(y \cdot \left(x + \color{blue}{-0.5}\right) + 0.918938533204673\right) - x \]
    5. Applied egg-rr100.0%

      \[\leadsto \color{blue}{\left(y \cdot \left(x + -0.5\right) + 0.918938533204673\right)} - x \]
    6. Taylor expanded in x around inf 98.5%

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

    if -1.7e6 < x < 10400

    1. Initial program 100.0%

      \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
    2. Step-by-step derivation
      1. cancel-sign-sub-inv100.0%

        \[\leadsto \color{blue}{\left(x \cdot \left(y - 1\right) + \left(-y\right) \cdot 0.5\right)} + 0.918938533204673 \]
      2. +-commutative100.0%

        \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot \left(y - 1\right)\right)} + 0.918938533204673 \]
      3. distribute-lft-out--100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y - x \cdot 1\right)}\right) + 0.918938533204673 \]
      4. cancel-sign-sub-inv100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y + \left(-x\right) \cdot 1\right)}\right) + 0.918938533204673 \]
      5. *-rgt-identity100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \left(x \cdot y + \color{blue}{\left(-x\right)}\right)\right) + 0.918938533204673 \]
      6. associate-+r+100.0%

        \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(-x\right)\right)} + 0.918938533204673 \]
      7. associate-+l+100.0%

        \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(\left(-x\right) + 0.918938533204673\right)} \]
      8. +-commutative100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 + \left(-x\right)\right)} \]
      9. unsub-neg100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 - x\right)} \]
      10. associate-+r-100.0%

        \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + 0.918938533204673\right) - x} \]
      11. *-commutative100.0%

        \[\leadsto \left(\left(\left(-y\right) \cdot 0.5 + \color{blue}{y \cdot x}\right) + 0.918938533204673\right) - x \]
      12. distribute-lft-neg-out100.0%

        \[\leadsto \left(\left(\color{blue}{\left(-y \cdot 0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
      13. distribute-rgt-neg-in100.0%

        \[\leadsto \left(\left(\color{blue}{y \cdot \left(-0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
      14. distribute-lft-out100.0%

        \[\leadsto \left(\color{blue}{y \cdot \left(\left(-0.5\right) + x\right)} + 0.918938533204673\right) - x \]
      15. fma-def100.0%

        \[\leadsto \color{blue}{\mathsf{fma}\left(y, \left(-0.5\right) + x, 0.918938533204673\right)} - x \]
      16. +-commutative100.0%

        \[\leadsto \mathsf{fma}\left(y, \color{blue}{x + \left(-0.5\right)}, 0.918938533204673\right) - x \]
      17. sub-neg100.0%

        \[\leadsto \mathsf{fma}\left(y, \color{blue}{x - 0.5}, 0.918938533204673\right) - x \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(y, x - 0.5, 0.918938533204673\right) - x} \]
    4. Taylor expanded in y around 0 53.4%

      \[\leadsto \color{blue}{0.918938533204673 - x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification75.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1700000 \lor \neg \left(x \leq 10400\right):\\ \;\;\;\;x \cdot \left(y + -1\right)\\ \mathbf{else}:\\ \;\;\;\;0.918938533204673 - x\\ \end{array} \]

Alternative 4: 98.1% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -1.4 \lor \neg \left(y \leq 1.8\right):\\ \;\;\;\;y \cdot \left(x - 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.918938533204673 - x\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (or (<= y -1.4) (not (<= y 1.8)))
   (* y (- x 0.5))
   (- 0.918938533204673 x)))
double code(double x, double y) {
	double tmp;
	if ((y <= -1.4) || !(y <= 1.8)) {
		tmp = y * (x - 0.5);
	} else {
		tmp = 0.918938533204673 - x;
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: tmp
    if ((y <= (-1.4d0)) .or. (.not. (y <= 1.8d0))) then
        tmp = y * (x - 0.5d0)
    else
        tmp = 0.918938533204673d0 - x
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double tmp;
	if ((y <= -1.4) || !(y <= 1.8)) {
		tmp = y * (x - 0.5);
	} else {
		tmp = 0.918938533204673 - x;
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if (y <= -1.4) or not (y <= 1.8):
		tmp = y * (x - 0.5)
	else:
		tmp = 0.918938533204673 - x
	return tmp
function code(x, y)
	tmp = 0.0
	if ((y <= -1.4) || !(y <= 1.8))
		tmp = Float64(y * Float64(x - 0.5));
	else
		tmp = Float64(0.918938533204673 - x);
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if ((y <= -1.4) || ~((y <= 1.8)))
		tmp = y * (x - 0.5);
	else
		tmp = 0.918938533204673 - x;
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[Or[LessEqual[y, -1.4], N[Not[LessEqual[y, 1.8]], $MachinePrecision]], N[(y * N[(x - 0.5), $MachinePrecision]), $MachinePrecision], N[(0.918938533204673 - x), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -1.4 \lor \neg \left(y \leq 1.8\right):\\
\;\;\;\;y \cdot \left(x - 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;0.918938533204673 - x\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < -1.3999999999999999 or 1.80000000000000004 < y

    1. Initial program 100.0%

      \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
    2. Step-by-step derivation
      1. cancel-sign-sub-inv100.0%

        \[\leadsto \color{blue}{\left(x \cdot \left(y - 1\right) + \left(-y\right) \cdot 0.5\right)} + 0.918938533204673 \]
      2. +-commutative100.0%

        \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot \left(y - 1\right)\right)} + 0.918938533204673 \]
      3. distribute-lft-out--100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y - x \cdot 1\right)}\right) + 0.918938533204673 \]
      4. cancel-sign-sub-inv100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y + \left(-x\right) \cdot 1\right)}\right) + 0.918938533204673 \]
      5. *-rgt-identity100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \left(x \cdot y + \color{blue}{\left(-x\right)}\right)\right) + 0.918938533204673 \]
      6. associate-+r+100.0%

        \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(-x\right)\right)} + 0.918938533204673 \]
      7. associate-+l+100.0%

        \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(\left(-x\right) + 0.918938533204673\right)} \]
      8. +-commutative100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 + \left(-x\right)\right)} \]
      9. unsub-neg100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 - x\right)} \]
      10. associate-+r-100.0%

        \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + 0.918938533204673\right) - x} \]
      11. *-commutative100.0%

        \[\leadsto \left(\left(\left(-y\right) \cdot 0.5 + \color{blue}{y \cdot x}\right) + 0.918938533204673\right) - x \]
      12. distribute-lft-neg-out100.0%

        \[\leadsto \left(\left(\color{blue}{\left(-y \cdot 0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
      13. distribute-rgt-neg-in100.0%

        \[\leadsto \left(\left(\color{blue}{y \cdot \left(-0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
      14. distribute-lft-out99.9%

        \[\leadsto \left(\color{blue}{y \cdot \left(\left(-0.5\right) + x\right)} + 0.918938533204673\right) - x \]
      15. fma-def99.9%

        \[\leadsto \color{blue}{\mathsf{fma}\left(y, \left(-0.5\right) + x, 0.918938533204673\right)} - x \]
      16. +-commutative99.9%

        \[\leadsto \mathsf{fma}\left(y, \color{blue}{x + \left(-0.5\right)}, 0.918938533204673\right) - x \]
      17. sub-neg99.9%

        \[\leadsto \mathsf{fma}\left(y, \color{blue}{x - 0.5}, 0.918938533204673\right) - x \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\mathsf{fma}\left(y, x - 0.5, 0.918938533204673\right) - x} \]
    4. Taylor expanded in y around inf 98.3%

      \[\leadsto \color{blue}{y \cdot \left(x - 0.5\right)} \]

    if -1.3999999999999999 < y < 1.80000000000000004

    1. Initial program 100.0%

      \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
    2. Step-by-step derivation
      1. cancel-sign-sub-inv100.0%

        \[\leadsto \color{blue}{\left(x \cdot \left(y - 1\right) + \left(-y\right) \cdot 0.5\right)} + 0.918938533204673 \]
      2. +-commutative100.0%

        \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot \left(y - 1\right)\right)} + 0.918938533204673 \]
      3. distribute-lft-out--100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y - x \cdot 1\right)}\right) + 0.918938533204673 \]
      4. cancel-sign-sub-inv100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y + \left(-x\right) \cdot 1\right)}\right) + 0.918938533204673 \]
      5. *-rgt-identity100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \left(x \cdot y + \color{blue}{\left(-x\right)}\right)\right) + 0.918938533204673 \]
      6. associate-+r+100.0%

        \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(-x\right)\right)} + 0.918938533204673 \]
      7. associate-+l+100.0%

        \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(\left(-x\right) + 0.918938533204673\right)} \]
      8. +-commutative100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 + \left(-x\right)\right)} \]
      9. unsub-neg100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 - x\right)} \]
      10. associate-+r-100.0%

        \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + 0.918938533204673\right) - x} \]
      11. *-commutative100.0%

        \[\leadsto \left(\left(\left(-y\right) \cdot 0.5 + \color{blue}{y \cdot x}\right) + 0.918938533204673\right) - x \]
      12. distribute-lft-neg-out100.0%

        \[\leadsto \left(\left(\color{blue}{\left(-y \cdot 0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
      13. distribute-rgt-neg-in100.0%

        \[\leadsto \left(\left(\color{blue}{y \cdot \left(-0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
      14. distribute-lft-out100.0%

        \[\leadsto \left(\color{blue}{y \cdot \left(\left(-0.5\right) + x\right)} + 0.918938533204673\right) - x \]
      15. fma-def100.0%

        \[\leadsto \color{blue}{\mathsf{fma}\left(y, \left(-0.5\right) + x, 0.918938533204673\right)} - x \]
      16. +-commutative100.0%

        \[\leadsto \mathsf{fma}\left(y, \color{blue}{x + \left(-0.5\right)}, 0.918938533204673\right) - x \]
      17. sub-neg100.0%

        \[\leadsto \mathsf{fma}\left(y, \color{blue}{x - 0.5}, 0.918938533204673\right) - x \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(y, x - 0.5, 0.918938533204673\right) - x} \]
    4. Taylor expanded in y around 0 98.0%

      \[\leadsto \color{blue}{0.918938533204673 - x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -1.4 \lor \neg \left(y \leq 1.8\right):\\ \;\;\;\;y \cdot \left(x - 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.918938533204673 - x\\ \end{array} \]

Alternative 5: 100.0% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \left(0.918938533204673 + y \cdot \left(x + -0.5\right)\right) - x \end{array} \]
(FPCore (x y) :precision binary64 (- (+ 0.918938533204673 (* y (+ x -0.5))) x))
double code(double x, double y) {
	return (0.918938533204673 + (y * (x + -0.5))) - x;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = (0.918938533204673d0 + (y * (x + (-0.5d0)))) - x
end function
public static double code(double x, double y) {
	return (0.918938533204673 + (y * (x + -0.5))) - x;
}
def code(x, y):
	return (0.918938533204673 + (y * (x + -0.5))) - x
function code(x, y)
	return Float64(Float64(0.918938533204673 + Float64(y * Float64(x + -0.5))) - x)
end
function tmp = code(x, y)
	tmp = (0.918938533204673 + (y * (x + -0.5))) - x;
end
code[x_, y_] := N[(N[(0.918938533204673 + N[(y * N[(x + -0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - x), $MachinePrecision]
\begin{array}{l}

\\
\left(0.918938533204673 + y \cdot \left(x + -0.5\right)\right) - x
\end{array}
Derivation
  1. Initial program 100.0%

    \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
  2. Step-by-step derivation
    1. cancel-sign-sub-inv100.0%

      \[\leadsto \color{blue}{\left(x \cdot \left(y - 1\right) + \left(-y\right) \cdot 0.5\right)} + 0.918938533204673 \]
    2. +-commutative100.0%

      \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot \left(y - 1\right)\right)} + 0.918938533204673 \]
    3. distribute-lft-out--100.0%

      \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y - x \cdot 1\right)}\right) + 0.918938533204673 \]
    4. cancel-sign-sub-inv100.0%

      \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y + \left(-x\right) \cdot 1\right)}\right) + 0.918938533204673 \]
    5. *-rgt-identity100.0%

      \[\leadsto \left(\left(-y\right) \cdot 0.5 + \left(x \cdot y + \color{blue}{\left(-x\right)}\right)\right) + 0.918938533204673 \]
    6. associate-+r+100.0%

      \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(-x\right)\right)} + 0.918938533204673 \]
    7. associate-+l+100.0%

      \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(\left(-x\right) + 0.918938533204673\right)} \]
    8. +-commutative100.0%

      \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 + \left(-x\right)\right)} \]
    9. unsub-neg100.0%

      \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 - x\right)} \]
    10. associate-+r-100.0%

      \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + 0.918938533204673\right) - x} \]
    11. *-commutative100.0%

      \[\leadsto \left(\left(\left(-y\right) \cdot 0.5 + \color{blue}{y \cdot x}\right) + 0.918938533204673\right) - x \]
    12. distribute-lft-neg-out100.0%

      \[\leadsto \left(\left(\color{blue}{\left(-y \cdot 0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
    13. distribute-rgt-neg-in100.0%

      \[\leadsto \left(\left(\color{blue}{y \cdot \left(-0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
    14. distribute-lft-out100.0%

      \[\leadsto \left(\color{blue}{y \cdot \left(\left(-0.5\right) + x\right)} + 0.918938533204673\right) - x \]
    15. fma-def100.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(y, \left(-0.5\right) + x, 0.918938533204673\right)} - x \]
    16. +-commutative100.0%

      \[\leadsto \mathsf{fma}\left(y, \color{blue}{x + \left(-0.5\right)}, 0.918938533204673\right) - x \]
    17. sub-neg100.0%

      \[\leadsto \mathsf{fma}\left(y, \color{blue}{x - 0.5}, 0.918938533204673\right) - x \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\mathsf{fma}\left(y, x - 0.5, 0.918938533204673\right) - x} \]
  4. Step-by-step derivation
    1. fma-udef100.0%

      \[\leadsto \color{blue}{\left(y \cdot \left(x - 0.5\right) + 0.918938533204673\right)} - x \]
    2. *-un-lft-identity100.0%

      \[\leadsto \left(y \cdot \color{blue}{\left(1 \cdot \left(x - 0.5\right)\right)} + 0.918938533204673\right) - x \]
    3. *-un-lft-identity100.0%

      \[\leadsto \left(y \cdot \color{blue}{\left(x - 0.5\right)} + 0.918938533204673\right) - x \]
    4. sub-neg100.0%

      \[\leadsto \left(y \cdot \color{blue}{\left(x + \left(-0.5\right)\right)} + 0.918938533204673\right) - x \]
    5. metadata-eval100.0%

      \[\leadsto \left(y \cdot \left(x + \color{blue}{-0.5}\right) + 0.918938533204673\right) - x \]
  5. Applied egg-rr100.0%

    \[\leadsto \color{blue}{\left(y \cdot \left(x + -0.5\right) + 0.918938533204673\right)} - x \]
  6. Final simplification100.0%

    \[\leadsto \left(0.918938533204673 + y \cdot \left(x + -0.5\right)\right) - x \]

Alternative 6: 49.4% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -1:\\ \;\;\;\;x \cdot y\\ \mathbf{elif}\;y \leq 1:\\ \;\;\;\;-x\\ \mathbf{else}:\\ \;\;\;\;x \cdot y\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= y -1.0) (* x y) (if (<= y 1.0) (- x) (* x y))))
double code(double x, double y) {
	double tmp;
	if (y <= -1.0) {
		tmp = x * y;
	} else if (y <= 1.0) {
		tmp = -x;
	} else {
		tmp = x * y;
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: tmp
    if (y <= (-1.0d0)) then
        tmp = x * y
    else if (y <= 1.0d0) then
        tmp = -x
    else
        tmp = x * y
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double tmp;
	if (y <= -1.0) {
		tmp = x * y;
	} else if (y <= 1.0) {
		tmp = -x;
	} else {
		tmp = x * y;
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if y <= -1.0:
		tmp = x * y
	elif y <= 1.0:
		tmp = -x
	else:
		tmp = x * y
	return tmp
function code(x, y)
	tmp = 0.0
	if (y <= -1.0)
		tmp = Float64(x * y);
	elseif (y <= 1.0)
		tmp = Float64(-x);
	else
		tmp = Float64(x * y);
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if (y <= -1.0)
		tmp = x * y;
	elseif (y <= 1.0)
		tmp = -x;
	else
		tmp = x * y;
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[LessEqual[y, -1.0], N[(x * y), $MachinePrecision], If[LessEqual[y, 1.0], (-x), N[(x * y), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -1:\\
\;\;\;\;x \cdot y\\

\mathbf{elif}\;y \leq 1:\\
\;\;\;\;-x\\

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


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

    1. Initial program 100.0%

      \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
    2. Step-by-step derivation
      1. cancel-sign-sub-inv100.0%

        \[\leadsto \color{blue}{\left(x \cdot \left(y - 1\right) + \left(-y\right) \cdot 0.5\right)} + 0.918938533204673 \]
      2. +-commutative100.0%

        \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot \left(y - 1\right)\right)} + 0.918938533204673 \]
      3. distribute-lft-out--100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y - x \cdot 1\right)}\right) + 0.918938533204673 \]
      4. cancel-sign-sub-inv100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y + \left(-x\right) \cdot 1\right)}\right) + 0.918938533204673 \]
      5. *-rgt-identity100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \left(x \cdot y + \color{blue}{\left(-x\right)}\right)\right) + 0.918938533204673 \]
      6. associate-+r+100.0%

        \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(-x\right)\right)} + 0.918938533204673 \]
      7. associate-+l+100.0%

        \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(\left(-x\right) + 0.918938533204673\right)} \]
      8. +-commutative100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 + \left(-x\right)\right)} \]
      9. unsub-neg100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 - x\right)} \]
      10. associate-+r-100.0%

        \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + 0.918938533204673\right) - x} \]
      11. *-commutative100.0%

        \[\leadsto \left(\left(\left(-y\right) \cdot 0.5 + \color{blue}{y \cdot x}\right) + 0.918938533204673\right) - x \]
      12. distribute-lft-neg-out100.0%

        \[\leadsto \left(\left(\color{blue}{\left(-y \cdot 0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
      13. distribute-rgt-neg-in100.0%

        \[\leadsto \left(\left(\color{blue}{y \cdot \left(-0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
      14. distribute-lft-out99.9%

        \[\leadsto \left(\color{blue}{y \cdot \left(\left(-0.5\right) + x\right)} + 0.918938533204673\right) - x \]
      15. fma-def99.9%

        \[\leadsto \color{blue}{\mathsf{fma}\left(y, \left(-0.5\right) + x, 0.918938533204673\right)} - x \]
      16. +-commutative99.9%

        \[\leadsto \mathsf{fma}\left(y, \color{blue}{x + \left(-0.5\right)}, 0.918938533204673\right) - x \]
      17. sub-neg99.9%

        \[\leadsto \mathsf{fma}\left(y, \color{blue}{x - 0.5}, 0.918938533204673\right) - x \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\mathsf{fma}\left(y, x - 0.5, 0.918938533204673\right) - x} \]
    4. Step-by-step derivation
      1. fma-udef99.9%

        \[\leadsto \color{blue}{\left(y \cdot \left(x - 0.5\right) + 0.918938533204673\right)} - x \]
      2. *-un-lft-identity99.9%

        \[\leadsto \left(y \cdot \color{blue}{\left(1 \cdot \left(x - 0.5\right)\right)} + 0.918938533204673\right) - x \]
      3. *-un-lft-identity99.9%

        \[\leadsto \left(y \cdot \color{blue}{\left(x - 0.5\right)} + 0.918938533204673\right) - x \]
      4. sub-neg99.9%

        \[\leadsto \left(y \cdot \color{blue}{\left(x + \left(-0.5\right)\right)} + 0.918938533204673\right) - x \]
      5. metadata-eval99.9%

        \[\leadsto \left(y \cdot \left(x + \color{blue}{-0.5}\right) + 0.918938533204673\right) - x \]
    5. Applied egg-rr99.9%

      \[\leadsto \color{blue}{\left(y \cdot \left(x + -0.5\right) + 0.918938533204673\right)} - x \]
    6. Taylor expanded in x around inf 51.7%

      \[\leadsto \color{blue}{x \cdot \left(y - 1\right)} \]
    7. Taylor expanded in y around inf 50.9%

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

    if -1 < y < 1

    1. Initial program 100.0%

      \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
    2. Step-by-step derivation
      1. cancel-sign-sub-inv100.0%

        \[\leadsto \color{blue}{\left(x \cdot \left(y - 1\right) + \left(-y\right) \cdot 0.5\right)} + 0.918938533204673 \]
      2. +-commutative100.0%

        \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot \left(y - 1\right)\right)} + 0.918938533204673 \]
      3. distribute-lft-out--100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y - x \cdot 1\right)}\right) + 0.918938533204673 \]
      4. cancel-sign-sub-inv100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y + \left(-x\right) \cdot 1\right)}\right) + 0.918938533204673 \]
      5. *-rgt-identity100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \left(x \cdot y + \color{blue}{\left(-x\right)}\right)\right) + 0.918938533204673 \]
      6. associate-+r+100.0%

        \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(-x\right)\right)} + 0.918938533204673 \]
      7. associate-+l+100.0%

        \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(\left(-x\right) + 0.918938533204673\right)} \]
      8. +-commutative100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 + \left(-x\right)\right)} \]
      9. unsub-neg100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 - x\right)} \]
      10. associate-+r-100.0%

        \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + 0.918938533204673\right) - x} \]
      11. *-commutative100.0%

        \[\leadsto \left(\left(\left(-y\right) \cdot 0.5 + \color{blue}{y \cdot x}\right) + 0.918938533204673\right) - x \]
      12. distribute-lft-neg-out100.0%

        \[\leadsto \left(\left(\color{blue}{\left(-y \cdot 0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
      13. distribute-rgt-neg-in100.0%

        \[\leadsto \left(\left(\color{blue}{y \cdot \left(-0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
      14. distribute-lft-out100.0%

        \[\leadsto \left(\color{blue}{y \cdot \left(\left(-0.5\right) + x\right)} + 0.918938533204673\right) - x \]
      15. fma-def100.0%

        \[\leadsto \color{blue}{\mathsf{fma}\left(y, \left(-0.5\right) + x, 0.918938533204673\right)} - x \]
      16. +-commutative100.0%

        \[\leadsto \mathsf{fma}\left(y, \color{blue}{x + \left(-0.5\right)}, 0.918938533204673\right) - x \]
      17. sub-neg100.0%

        \[\leadsto \mathsf{fma}\left(y, \color{blue}{x - 0.5}, 0.918938533204673\right) - x \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(y, x - 0.5, 0.918938533204673\right) - x} \]
    4. Step-by-step derivation
      1. fma-udef100.0%

        \[\leadsto \color{blue}{\left(y \cdot \left(x - 0.5\right) + 0.918938533204673\right)} - x \]
      2. *-un-lft-identity100.0%

        \[\leadsto \left(y \cdot \color{blue}{\left(1 \cdot \left(x - 0.5\right)\right)} + 0.918938533204673\right) - x \]
      3. *-un-lft-identity100.0%

        \[\leadsto \left(y \cdot \color{blue}{\left(x - 0.5\right)} + 0.918938533204673\right) - x \]
      4. sub-neg100.0%

        \[\leadsto \left(y \cdot \color{blue}{\left(x + \left(-0.5\right)\right)} + 0.918938533204673\right) - x \]
      5. metadata-eval100.0%

        \[\leadsto \left(y \cdot \left(x + \color{blue}{-0.5}\right) + 0.918938533204673\right) - x \]
    5. Applied egg-rr100.0%

      \[\leadsto \color{blue}{\left(y \cdot \left(x + -0.5\right) + 0.918938533204673\right)} - x \]
    6. Taylor expanded in x around inf 47.5%

      \[\leadsto \color{blue}{x \cdot \left(y - 1\right)} \]
    7. Taylor expanded in y around 0 46.0%

      \[\leadsto \color{blue}{-1 \cdot x} \]
    8. Step-by-step derivation
      1. neg-mul-146.0%

        \[\leadsto \color{blue}{-x} \]
    9. Simplified46.0%

      \[\leadsto \color{blue}{-x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification48.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -1:\\ \;\;\;\;x \cdot y\\ \mathbf{elif}\;y \leq 1:\\ \;\;\;\;-x\\ \mathbf{else}:\\ \;\;\;\;x \cdot y\\ \end{array} \]

Alternative 7: 73.6% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -50:\\ \;\;\;\;x \cdot y\\ \mathbf{elif}\;y \leq 1.1:\\ \;\;\;\;0.918938533204673 - x\\ \mathbf{else}:\\ \;\;\;\;x \cdot y\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= y -50.0) (* x y) (if (<= y 1.1) (- 0.918938533204673 x) (* x y))))
double code(double x, double y) {
	double tmp;
	if (y <= -50.0) {
		tmp = x * y;
	} else if (y <= 1.1) {
		tmp = 0.918938533204673 - x;
	} else {
		tmp = x * y;
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: tmp
    if (y <= (-50.0d0)) then
        tmp = x * y
    else if (y <= 1.1d0) then
        tmp = 0.918938533204673d0 - x
    else
        tmp = x * y
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double tmp;
	if (y <= -50.0) {
		tmp = x * y;
	} else if (y <= 1.1) {
		tmp = 0.918938533204673 - x;
	} else {
		tmp = x * y;
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if y <= -50.0:
		tmp = x * y
	elif y <= 1.1:
		tmp = 0.918938533204673 - x
	else:
		tmp = x * y
	return tmp
function code(x, y)
	tmp = 0.0
	if (y <= -50.0)
		tmp = Float64(x * y);
	elseif (y <= 1.1)
		tmp = Float64(0.918938533204673 - x);
	else
		tmp = Float64(x * y);
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if (y <= -50.0)
		tmp = x * y;
	elseif (y <= 1.1)
		tmp = 0.918938533204673 - x;
	else
		tmp = x * y;
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[LessEqual[y, -50.0], N[(x * y), $MachinePrecision], If[LessEqual[y, 1.1], N[(0.918938533204673 - x), $MachinePrecision], N[(x * y), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -50:\\
\;\;\;\;x \cdot y\\

\mathbf{elif}\;y \leq 1.1:\\
\;\;\;\;0.918938533204673 - x\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < -50 or 1.1000000000000001 < y

    1. Initial program 100.0%

      \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
    2. Step-by-step derivation
      1. cancel-sign-sub-inv100.0%

        \[\leadsto \color{blue}{\left(x \cdot \left(y - 1\right) + \left(-y\right) \cdot 0.5\right)} + 0.918938533204673 \]
      2. +-commutative100.0%

        \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot \left(y - 1\right)\right)} + 0.918938533204673 \]
      3. distribute-lft-out--100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y - x \cdot 1\right)}\right) + 0.918938533204673 \]
      4. cancel-sign-sub-inv100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y + \left(-x\right) \cdot 1\right)}\right) + 0.918938533204673 \]
      5. *-rgt-identity100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \left(x \cdot y + \color{blue}{\left(-x\right)}\right)\right) + 0.918938533204673 \]
      6. associate-+r+100.0%

        \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(-x\right)\right)} + 0.918938533204673 \]
      7. associate-+l+100.0%

        \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(\left(-x\right) + 0.918938533204673\right)} \]
      8. +-commutative100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 + \left(-x\right)\right)} \]
      9. unsub-neg100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 - x\right)} \]
      10. associate-+r-100.0%

        \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + 0.918938533204673\right) - x} \]
      11. *-commutative100.0%

        \[\leadsto \left(\left(\left(-y\right) \cdot 0.5 + \color{blue}{y \cdot x}\right) + 0.918938533204673\right) - x \]
      12. distribute-lft-neg-out100.0%

        \[\leadsto \left(\left(\color{blue}{\left(-y \cdot 0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
      13. distribute-rgt-neg-in100.0%

        \[\leadsto \left(\left(\color{blue}{y \cdot \left(-0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
      14. distribute-lft-out99.9%

        \[\leadsto \left(\color{blue}{y \cdot \left(\left(-0.5\right) + x\right)} + 0.918938533204673\right) - x \]
      15. fma-def99.9%

        \[\leadsto \color{blue}{\mathsf{fma}\left(y, \left(-0.5\right) + x, 0.918938533204673\right)} - x \]
      16. +-commutative99.9%

        \[\leadsto \mathsf{fma}\left(y, \color{blue}{x + \left(-0.5\right)}, 0.918938533204673\right) - x \]
      17. sub-neg99.9%

        \[\leadsto \mathsf{fma}\left(y, \color{blue}{x - 0.5}, 0.918938533204673\right) - x \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\mathsf{fma}\left(y, x - 0.5, 0.918938533204673\right) - x} \]
    4. Step-by-step derivation
      1. fma-udef99.9%

        \[\leadsto \color{blue}{\left(y \cdot \left(x - 0.5\right) + 0.918938533204673\right)} - x \]
      2. *-un-lft-identity99.9%

        \[\leadsto \left(y \cdot \color{blue}{\left(1 \cdot \left(x - 0.5\right)\right)} + 0.918938533204673\right) - x \]
      3. *-un-lft-identity99.9%

        \[\leadsto \left(y \cdot \color{blue}{\left(x - 0.5\right)} + 0.918938533204673\right) - x \]
      4. sub-neg99.9%

        \[\leadsto \left(y \cdot \color{blue}{\left(x + \left(-0.5\right)\right)} + 0.918938533204673\right) - x \]
      5. metadata-eval99.9%

        \[\leadsto \left(y \cdot \left(x + \color{blue}{-0.5}\right) + 0.918938533204673\right) - x \]
    5. Applied egg-rr99.9%

      \[\leadsto \color{blue}{\left(y \cdot \left(x + -0.5\right) + 0.918938533204673\right)} - x \]
    6. Taylor expanded in x around inf 51.7%

      \[\leadsto \color{blue}{x \cdot \left(y - 1\right)} \]
    7. Taylor expanded in y around inf 50.9%

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

    if -50 < y < 1.1000000000000001

    1. Initial program 100.0%

      \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
    2. Step-by-step derivation
      1. cancel-sign-sub-inv100.0%

        \[\leadsto \color{blue}{\left(x \cdot \left(y - 1\right) + \left(-y\right) \cdot 0.5\right)} + 0.918938533204673 \]
      2. +-commutative100.0%

        \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot \left(y - 1\right)\right)} + 0.918938533204673 \]
      3. distribute-lft-out--100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y - x \cdot 1\right)}\right) + 0.918938533204673 \]
      4. cancel-sign-sub-inv100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y + \left(-x\right) \cdot 1\right)}\right) + 0.918938533204673 \]
      5. *-rgt-identity100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + \left(x \cdot y + \color{blue}{\left(-x\right)}\right)\right) + 0.918938533204673 \]
      6. associate-+r+100.0%

        \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(-x\right)\right)} + 0.918938533204673 \]
      7. associate-+l+100.0%

        \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(\left(-x\right) + 0.918938533204673\right)} \]
      8. +-commutative100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 + \left(-x\right)\right)} \]
      9. unsub-neg100.0%

        \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 - x\right)} \]
      10. associate-+r-100.0%

        \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + 0.918938533204673\right) - x} \]
      11. *-commutative100.0%

        \[\leadsto \left(\left(\left(-y\right) \cdot 0.5 + \color{blue}{y \cdot x}\right) + 0.918938533204673\right) - x \]
      12. distribute-lft-neg-out100.0%

        \[\leadsto \left(\left(\color{blue}{\left(-y \cdot 0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
      13. distribute-rgt-neg-in100.0%

        \[\leadsto \left(\left(\color{blue}{y \cdot \left(-0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
      14. distribute-lft-out100.0%

        \[\leadsto \left(\color{blue}{y \cdot \left(\left(-0.5\right) + x\right)} + 0.918938533204673\right) - x \]
      15. fma-def100.0%

        \[\leadsto \color{blue}{\mathsf{fma}\left(y, \left(-0.5\right) + x, 0.918938533204673\right)} - x \]
      16. +-commutative100.0%

        \[\leadsto \mathsf{fma}\left(y, \color{blue}{x + \left(-0.5\right)}, 0.918938533204673\right) - x \]
      17. sub-neg100.0%

        \[\leadsto \mathsf{fma}\left(y, \color{blue}{x - 0.5}, 0.918938533204673\right) - x \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(y, x - 0.5, 0.918938533204673\right) - x} \]
    4. Taylor expanded in y around 0 98.0%

      \[\leadsto \color{blue}{0.918938533204673 - x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification74.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -50:\\ \;\;\;\;x \cdot y\\ \mathbf{elif}\;y \leq 1.1:\\ \;\;\;\;0.918938533204673 - x\\ \mathbf{else}:\\ \;\;\;\;x \cdot y\\ \end{array} \]

Alternative 8: 26.4% accurate, 5.5× speedup?

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

\\
-x
\end{array}
Derivation
  1. Initial program 100.0%

    \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
  2. Step-by-step derivation
    1. cancel-sign-sub-inv100.0%

      \[\leadsto \color{blue}{\left(x \cdot \left(y - 1\right) + \left(-y\right) \cdot 0.5\right)} + 0.918938533204673 \]
    2. +-commutative100.0%

      \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot \left(y - 1\right)\right)} + 0.918938533204673 \]
    3. distribute-lft-out--100.0%

      \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y - x \cdot 1\right)}\right) + 0.918938533204673 \]
    4. cancel-sign-sub-inv100.0%

      \[\leadsto \left(\left(-y\right) \cdot 0.5 + \color{blue}{\left(x \cdot y + \left(-x\right) \cdot 1\right)}\right) + 0.918938533204673 \]
    5. *-rgt-identity100.0%

      \[\leadsto \left(\left(-y\right) \cdot 0.5 + \left(x \cdot y + \color{blue}{\left(-x\right)}\right)\right) + 0.918938533204673 \]
    6. associate-+r+100.0%

      \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(-x\right)\right)} + 0.918938533204673 \]
    7. associate-+l+100.0%

      \[\leadsto \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \left(\left(-x\right) + 0.918938533204673\right)} \]
    8. +-commutative100.0%

      \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 + \left(-x\right)\right)} \]
    9. unsub-neg100.0%

      \[\leadsto \left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + \color{blue}{\left(0.918938533204673 - x\right)} \]
    10. associate-+r-100.0%

      \[\leadsto \color{blue}{\left(\left(\left(-y\right) \cdot 0.5 + x \cdot y\right) + 0.918938533204673\right) - x} \]
    11. *-commutative100.0%

      \[\leadsto \left(\left(\left(-y\right) \cdot 0.5 + \color{blue}{y \cdot x}\right) + 0.918938533204673\right) - x \]
    12. distribute-lft-neg-out100.0%

      \[\leadsto \left(\left(\color{blue}{\left(-y \cdot 0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
    13. distribute-rgt-neg-in100.0%

      \[\leadsto \left(\left(\color{blue}{y \cdot \left(-0.5\right)} + y \cdot x\right) + 0.918938533204673\right) - x \]
    14. distribute-lft-out100.0%

      \[\leadsto \left(\color{blue}{y \cdot \left(\left(-0.5\right) + x\right)} + 0.918938533204673\right) - x \]
    15. fma-def100.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(y, \left(-0.5\right) + x, 0.918938533204673\right)} - x \]
    16. +-commutative100.0%

      \[\leadsto \mathsf{fma}\left(y, \color{blue}{x + \left(-0.5\right)}, 0.918938533204673\right) - x \]
    17. sub-neg100.0%

      \[\leadsto \mathsf{fma}\left(y, \color{blue}{x - 0.5}, 0.918938533204673\right) - x \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\mathsf{fma}\left(y, x - 0.5, 0.918938533204673\right) - x} \]
  4. Step-by-step derivation
    1. fma-udef100.0%

      \[\leadsto \color{blue}{\left(y \cdot \left(x - 0.5\right) + 0.918938533204673\right)} - x \]
    2. *-un-lft-identity100.0%

      \[\leadsto \left(y \cdot \color{blue}{\left(1 \cdot \left(x - 0.5\right)\right)} + 0.918938533204673\right) - x \]
    3. *-un-lft-identity100.0%

      \[\leadsto \left(y \cdot \color{blue}{\left(x - 0.5\right)} + 0.918938533204673\right) - x \]
    4. sub-neg100.0%

      \[\leadsto \left(y \cdot \color{blue}{\left(x + \left(-0.5\right)\right)} + 0.918938533204673\right) - x \]
    5. metadata-eval100.0%

      \[\leadsto \left(y \cdot \left(x + \color{blue}{-0.5}\right) + 0.918938533204673\right) - x \]
  5. Applied egg-rr100.0%

    \[\leadsto \color{blue}{\left(y \cdot \left(x + -0.5\right) + 0.918938533204673\right)} - x \]
  6. Taylor expanded in x around inf 49.7%

    \[\leadsto \color{blue}{x \cdot \left(y - 1\right)} \]
  7. Taylor expanded in y around 0 24.1%

    \[\leadsto \color{blue}{-1 \cdot x} \]
  8. Step-by-step derivation
    1. neg-mul-124.1%

      \[\leadsto \color{blue}{-x} \]
  9. Simplified24.1%

    \[\leadsto \color{blue}{-x} \]
  10. Final simplification24.1%

    \[\leadsto -x \]

Reproduce

?
herbie shell --seed 2023271 
(FPCore (x y)
  :name "Numeric.SpecFunctions:logGamma from math-functions-0.1.5.2, A"
  :precision binary64
  (+ (- (* x (- y 1.0)) (* y 0.5)) 0.918938533204673))