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

Percentage Accurate: 100.0% → 100.0%
Time: 4.4s
Alternatives: 8
Speedup: 1.0×

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, 0.1× speedup?

\[\begin{array}{l} \\ 0.918938533204673 - \mathsf{fma}\left(y, 0.5 - x, x\right) \end{array} \]
(FPCore (x y) :precision binary64 (- 0.918938533204673 (fma y (- 0.5 x) x)))
double code(double x, double y) {
	return 0.918938533204673 - fma(y, (0.5 - x), x);
}
function code(x, y)
	return Float64(0.918938533204673 - fma(y, Float64(0.5 - x), x))
end
code[x_, y_] := N[(0.918938533204673 - N[(y * N[(0.5 - x), $MachinePrecision] + x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0.918938533204673 - \mathsf{fma}\left(y, 0.5 - x, x\right)
\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. +-commutative100.0%

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

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

      \[\leadsto 0.918938533204673 + \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot \left(y - 1\right)\right)} \]
    4. associate-+r+100.0%

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

      \[\leadsto \color{blue}{\left(0.918938533204673 - y \cdot 0.5\right)} + x \cdot \left(y - 1\right) \]
    6. associate-+l-100.0%

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

      \[\leadsto 0.918938533204673 - \left(y \cdot 0.5 - x \cdot \color{blue}{\left(y + \left(-1\right)\right)}\right) \]
    8. distribute-rgt-in100.0%

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

      \[\leadsto 0.918938533204673 - \left(y \cdot 0.5 - \left(y \cdot x + \color{blue}{-1} \cdot x\right)\right) \]
    10. neg-mul-1100.0%

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

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

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

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

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

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

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

    \[\leadsto \color{blue}{0.918938533204673 - \mathsf{fma}\left(y, 0.5 - x, x\right)} \]
  4. Add Preprocessing
  5. Final simplification100.0%

    \[\leadsto 0.918938533204673 - \mathsf{fma}\left(y, 0.5 - x, x\right) \]
  6. Add Preprocessing

Alternative 2: 73.3% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -9 \cdot 10^{+260}:\\ \;\;\;\;y \cdot -0.5\\ \mathbf{elif}\;y \leq -3.4 \cdot 10^{+246}:\\ \;\;\;\;y \cdot x\\ \mathbf{elif}\;y \leq -1.25 \cdot 10^{+198}:\\ \;\;\;\;y \cdot -0.5\\ \mathbf{elif}\;y \leq -480000:\\ \;\;\;\;y \cdot x\\ \mathbf{elif}\;y \leq 1.85:\\ \;\;\;\;0.918938533204673 - x\\ \mathbf{elif}\;y \leq 1.45 \cdot 10^{+147} \lor \neg \left(y \leq 9 \cdot 10^{+201}\right):\\ \;\;\;\;y \cdot -0.5\\ \mathbf{else}:\\ \;\;\;\;y \cdot x\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= y -9e+260)
   (* y -0.5)
   (if (<= y -3.4e+246)
     (* y x)
     (if (<= y -1.25e+198)
       (* y -0.5)
       (if (<= y -480000.0)
         (* y x)
         (if (<= y 1.85)
           (- 0.918938533204673 x)
           (if (or (<= y 1.45e+147) (not (<= y 9e+201)))
             (* y -0.5)
             (* y x))))))))
double code(double x, double y) {
	double tmp;
	if (y <= -9e+260) {
		tmp = y * -0.5;
	} else if (y <= -3.4e+246) {
		tmp = y * x;
	} else if (y <= -1.25e+198) {
		tmp = y * -0.5;
	} else if (y <= -480000.0) {
		tmp = y * x;
	} else if (y <= 1.85) {
		tmp = 0.918938533204673 - x;
	} else if ((y <= 1.45e+147) || !(y <= 9e+201)) {
		tmp = y * -0.5;
	} else {
		tmp = y * x;
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: tmp
    if (y <= (-9d+260)) then
        tmp = y * (-0.5d0)
    else if (y <= (-3.4d+246)) then
        tmp = y * x
    else if (y <= (-1.25d+198)) then
        tmp = y * (-0.5d0)
    else if (y <= (-480000.0d0)) then
        tmp = y * x
    else if (y <= 1.85d0) then
        tmp = 0.918938533204673d0 - x
    else if ((y <= 1.45d+147) .or. (.not. (y <= 9d+201))) then
        tmp = y * (-0.5d0)
    else
        tmp = y * x
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double tmp;
	if (y <= -9e+260) {
		tmp = y * -0.5;
	} else if (y <= -3.4e+246) {
		tmp = y * x;
	} else if (y <= -1.25e+198) {
		tmp = y * -0.5;
	} else if (y <= -480000.0) {
		tmp = y * x;
	} else if (y <= 1.85) {
		tmp = 0.918938533204673 - x;
	} else if ((y <= 1.45e+147) || !(y <= 9e+201)) {
		tmp = y * -0.5;
	} else {
		tmp = y * x;
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if y <= -9e+260:
		tmp = y * -0.5
	elif y <= -3.4e+246:
		tmp = y * x
	elif y <= -1.25e+198:
		tmp = y * -0.5
	elif y <= -480000.0:
		tmp = y * x
	elif y <= 1.85:
		tmp = 0.918938533204673 - x
	elif (y <= 1.45e+147) or not (y <= 9e+201):
		tmp = y * -0.5
	else:
		tmp = y * x
	return tmp
function code(x, y)
	tmp = 0.0
	if (y <= -9e+260)
		tmp = Float64(y * -0.5);
	elseif (y <= -3.4e+246)
		tmp = Float64(y * x);
	elseif (y <= -1.25e+198)
		tmp = Float64(y * -0.5);
	elseif (y <= -480000.0)
		tmp = Float64(y * x);
	elseif (y <= 1.85)
		tmp = Float64(0.918938533204673 - x);
	elseif ((y <= 1.45e+147) || !(y <= 9e+201))
		tmp = Float64(y * -0.5);
	else
		tmp = Float64(y * x);
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if (y <= -9e+260)
		tmp = y * -0.5;
	elseif (y <= -3.4e+246)
		tmp = y * x;
	elseif (y <= -1.25e+198)
		tmp = y * -0.5;
	elseif (y <= -480000.0)
		tmp = y * x;
	elseif (y <= 1.85)
		tmp = 0.918938533204673 - x;
	elseif ((y <= 1.45e+147) || ~((y <= 9e+201)))
		tmp = y * -0.5;
	else
		tmp = y * x;
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[LessEqual[y, -9e+260], N[(y * -0.5), $MachinePrecision], If[LessEqual[y, -3.4e+246], N[(y * x), $MachinePrecision], If[LessEqual[y, -1.25e+198], N[(y * -0.5), $MachinePrecision], If[LessEqual[y, -480000.0], N[(y * x), $MachinePrecision], If[LessEqual[y, 1.85], N[(0.918938533204673 - x), $MachinePrecision], If[Or[LessEqual[y, 1.45e+147], N[Not[LessEqual[y, 9e+201]], $MachinePrecision]], N[(y * -0.5), $MachinePrecision], N[(y * x), $MachinePrecision]]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -9 \cdot 10^{+260}:\\
\;\;\;\;y \cdot -0.5\\

\mathbf{elif}\;y \leq -3.4 \cdot 10^{+246}:\\
\;\;\;\;y \cdot x\\

\mathbf{elif}\;y \leq -1.25 \cdot 10^{+198}:\\
\;\;\;\;y \cdot -0.5\\

\mathbf{elif}\;y \leq -480000:\\
\;\;\;\;y \cdot x\\

\mathbf{elif}\;y \leq 1.85:\\
\;\;\;\;0.918938533204673 - x\\

\mathbf{elif}\;y \leq 1.45 \cdot 10^{+147} \lor \neg \left(y \leq 9 \cdot 10^{+201}\right):\\
\;\;\;\;y \cdot -0.5\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y < -9.00000000000000045e260 or -3.39999999999999988e246 < y < -1.25000000000000012e198 or 1.8500000000000001 < y < 1.4499999999999999e147 or 9.0000000000000002e201 < 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. 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. Add Preprocessing
    5. Taylor expanded in y around inf 100.0%

      \[\leadsto \color{blue}{y \cdot \left(x - 0.5\right)} \]
    6. Taylor expanded in x around 0 67.8%

      \[\leadsto \color{blue}{-0.5 \cdot y} \]

    if -9.00000000000000045e260 < y < -3.39999999999999988e246 or -1.25000000000000012e198 < y < -4.8e5 or 1.4499999999999999e147 < y < 9.0000000000000002e201

    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. associate-+l-99.9%

        \[\leadsto \color{blue}{x \cdot \left(y - 1\right) - \left(y \cdot 0.5 - 0.918938533204673\right)} \]
      2. sub-neg99.9%

        \[\leadsto x \cdot \color{blue}{\left(y + \left(-1\right)\right)} - \left(y \cdot 0.5 - 0.918938533204673\right) \]
      3. metadata-eval99.9%

        \[\leadsto x \cdot \left(y + \color{blue}{-1}\right) - \left(y \cdot 0.5 - 0.918938533204673\right) \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{x \cdot \left(y + -1\right) - \left(y \cdot 0.5 - 0.918938533204673\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in y around inf 97.9%

      \[\leadsto \color{blue}{y \cdot \left(x - 0.5\right)} \]
    6. Taylor expanded in x around inf 68.7%

      \[\leadsto \color{blue}{x \cdot y} \]
    7. Step-by-step derivation
      1. *-commutative68.7%

        \[\leadsto \color{blue}{y \cdot x} \]
    8. Simplified68.7%

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

    if -4.8e5 < y < 1.8500000000000001

    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. +-commutative100.0%

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

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

        \[\leadsto 0.918938533204673 + \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot \left(y - 1\right)\right)} \]
      4. associate-+r+100.0%

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

        \[\leadsto \color{blue}{\left(0.918938533204673 - y \cdot 0.5\right)} + x \cdot \left(y - 1\right) \]
      6. associate-+l-100.0%

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

        \[\leadsto 0.918938533204673 - \left(y \cdot 0.5 - x \cdot \color{blue}{\left(y + \left(-1\right)\right)}\right) \]
      8. distribute-rgt-in100.0%

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

        \[\leadsto 0.918938533204673 - \left(y \cdot 0.5 - \left(y \cdot x + \color{blue}{-1} \cdot x\right)\right) \]
      10. neg-mul-1100.0%

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

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

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

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

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

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

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

      \[\leadsto \color{blue}{0.918938533204673 - \mathsf{fma}\left(y, 0.5 - x, x\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in y around 0 97.6%

      \[\leadsto 0.918938533204673 - \color{blue}{x} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification82.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -9 \cdot 10^{+260}:\\ \;\;\;\;y \cdot -0.5\\ \mathbf{elif}\;y \leq -3.4 \cdot 10^{+246}:\\ \;\;\;\;y \cdot x\\ \mathbf{elif}\;y \leq -1.25 \cdot 10^{+198}:\\ \;\;\;\;y \cdot -0.5\\ \mathbf{elif}\;y \leq -480000:\\ \;\;\;\;y \cdot x\\ \mathbf{elif}\;y \leq 1.85:\\ \;\;\;\;0.918938533204673 - x\\ \mathbf{elif}\;y \leq 1.45 \cdot 10^{+147} \lor \neg \left(y \leq 9 \cdot 10^{+201}\right):\\ \;\;\;\;y \cdot -0.5\\ \mathbf{else}:\\ \;\;\;\;y \cdot x\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 73.4% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -9.5 \cdot 10^{+258}:\\ \;\;\;\;y \cdot -0.5\\ \mathbf{elif}\;y \leq -3.6 \cdot 10^{+246}:\\ \;\;\;\;y \cdot x\\ \mathbf{elif}\;y \leq -2.25 \cdot 10^{+198}:\\ \;\;\;\;y \cdot -0.5\\ \mathbf{elif}\;y \leq -4 \cdot 10^{-14}:\\ \;\;\;\;x \cdot \left(y + -1\right)\\ \mathbf{elif}\;y \leq 1.85:\\ \;\;\;\;0.918938533204673 - x\\ \mathbf{elif}\;y \leq 1.5 \cdot 10^{+147} \lor \neg \left(y \leq 5.6 \cdot 10^{+200}\right):\\ \;\;\;\;y \cdot -0.5\\ \mathbf{else}:\\ \;\;\;\;y \cdot x\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= y -9.5e+258)
   (* y -0.5)
   (if (<= y -3.6e+246)
     (* y x)
     (if (<= y -2.25e+198)
       (* y -0.5)
       (if (<= y -4e-14)
         (* x (+ y -1.0))
         (if (<= y 1.85)
           (- 0.918938533204673 x)
           (if (or (<= y 1.5e+147) (not (<= y 5.6e+200)))
             (* y -0.5)
             (* y x))))))))
double code(double x, double y) {
	double tmp;
	if (y <= -9.5e+258) {
		tmp = y * -0.5;
	} else if (y <= -3.6e+246) {
		tmp = y * x;
	} else if (y <= -2.25e+198) {
		tmp = y * -0.5;
	} else if (y <= -4e-14) {
		tmp = x * (y + -1.0);
	} else if (y <= 1.85) {
		tmp = 0.918938533204673 - x;
	} else if ((y <= 1.5e+147) || !(y <= 5.6e+200)) {
		tmp = y * -0.5;
	} else {
		tmp = y * x;
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: tmp
    if (y <= (-9.5d+258)) then
        tmp = y * (-0.5d0)
    else if (y <= (-3.6d+246)) then
        tmp = y * x
    else if (y <= (-2.25d+198)) then
        tmp = y * (-0.5d0)
    else if (y <= (-4d-14)) then
        tmp = x * (y + (-1.0d0))
    else if (y <= 1.85d0) then
        tmp = 0.918938533204673d0 - x
    else if ((y <= 1.5d+147) .or. (.not. (y <= 5.6d+200))) then
        tmp = y * (-0.5d0)
    else
        tmp = y * x
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double tmp;
	if (y <= -9.5e+258) {
		tmp = y * -0.5;
	} else if (y <= -3.6e+246) {
		tmp = y * x;
	} else if (y <= -2.25e+198) {
		tmp = y * -0.5;
	} else if (y <= -4e-14) {
		tmp = x * (y + -1.0);
	} else if (y <= 1.85) {
		tmp = 0.918938533204673 - x;
	} else if ((y <= 1.5e+147) || !(y <= 5.6e+200)) {
		tmp = y * -0.5;
	} else {
		tmp = y * x;
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if y <= -9.5e+258:
		tmp = y * -0.5
	elif y <= -3.6e+246:
		tmp = y * x
	elif y <= -2.25e+198:
		tmp = y * -0.5
	elif y <= -4e-14:
		tmp = x * (y + -1.0)
	elif y <= 1.85:
		tmp = 0.918938533204673 - x
	elif (y <= 1.5e+147) or not (y <= 5.6e+200):
		tmp = y * -0.5
	else:
		tmp = y * x
	return tmp
function code(x, y)
	tmp = 0.0
	if (y <= -9.5e+258)
		tmp = Float64(y * -0.5);
	elseif (y <= -3.6e+246)
		tmp = Float64(y * x);
	elseif (y <= -2.25e+198)
		tmp = Float64(y * -0.5);
	elseif (y <= -4e-14)
		tmp = Float64(x * Float64(y + -1.0));
	elseif (y <= 1.85)
		tmp = Float64(0.918938533204673 - x);
	elseif ((y <= 1.5e+147) || !(y <= 5.6e+200))
		tmp = Float64(y * -0.5);
	else
		tmp = Float64(y * x);
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if (y <= -9.5e+258)
		tmp = y * -0.5;
	elseif (y <= -3.6e+246)
		tmp = y * x;
	elseif (y <= -2.25e+198)
		tmp = y * -0.5;
	elseif (y <= -4e-14)
		tmp = x * (y + -1.0);
	elseif (y <= 1.85)
		tmp = 0.918938533204673 - x;
	elseif ((y <= 1.5e+147) || ~((y <= 5.6e+200)))
		tmp = y * -0.5;
	else
		tmp = y * x;
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[LessEqual[y, -9.5e+258], N[(y * -0.5), $MachinePrecision], If[LessEqual[y, -3.6e+246], N[(y * x), $MachinePrecision], If[LessEqual[y, -2.25e+198], N[(y * -0.5), $MachinePrecision], If[LessEqual[y, -4e-14], N[(x * N[(y + -1.0), $MachinePrecision]), $MachinePrecision], If[LessEqual[y, 1.85], N[(0.918938533204673 - x), $MachinePrecision], If[Or[LessEqual[y, 1.5e+147], N[Not[LessEqual[y, 5.6e+200]], $MachinePrecision]], N[(y * -0.5), $MachinePrecision], N[(y * x), $MachinePrecision]]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -9.5 \cdot 10^{+258}:\\
\;\;\;\;y \cdot -0.5\\

\mathbf{elif}\;y \leq -3.6 \cdot 10^{+246}:\\
\;\;\;\;y \cdot x\\

\mathbf{elif}\;y \leq -2.25 \cdot 10^{+198}:\\
\;\;\;\;y \cdot -0.5\\

\mathbf{elif}\;y \leq -4 \cdot 10^{-14}:\\
\;\;\;\;x \cdot \left(y + -1\right)\\

\mathbf{elif}\;y \leq 1.85:\\
\;\;\;\;0.918938533204673 - x\\

\mathbf{elif}\;y \leq 1.5 \cdot 10^{+147} \lor \neg \left(y \leq 5.6 \cdot 10^{+200}\right):\\
\;\;\;\;y \cdot -0.5\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 4 regimes
  2. if y < -9.5e258 or -3.6e246 < y < -2.25000000000000001e198 or 1.8500000000000001 < y < 1.49999999999999997e147 or 5.59999999999999969e200 < 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. 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. Add Preprocessing
    5. Taylor expanded in y around inf 100.0%

      \[\leadsto \color{blue}{y \cdot \left(x - 0.5\right)} \]
    6. Taylor expanded in x around 0 67.8%

      \[\leadsto \color{blue}{-0.5 \cdot y} \]

    if -9.5e258 < y < -3.6e246 or 1.49999999999999997e147 < y < 5.59999999999999969e200

    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. Add Preprocessing
    5. Taylor expanded in y around inf 100.0%

      \[\leadsto \color{blue}{y \cdot \left(x - 0.5\right)} \]
    6. Taylor expanded in x around inf 86.3%

      \[\leadsto \color{blue}{x \cdot y} \]
    7. Step-by-step derivation
      1. *-commutative86.3%

        \[\leadsto \color{blue}{y \cdot x} \]
    8. Simplified86.3%

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

    if -2.25000000000000001e198 < y < -4e-14

    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. associate-+l-99.9%

        \[\leadsto \color{blue}{x \cdot \left(y - 1\right) - \left(y \cdot 0.5 - 0.918938533204673\right)} \]
      2. sub-neg99.9%

        \[\leadsto x \cdot \color{blue}{\left(y + \left(-1\right)\right)} - \left(y \cdot 0.5 - 0.918938533204673\right) \]
      3. metadata-eval99.9%

        \[\leadsto x \cdot \left(y + \color{blue}{-1}\right) - \left(y \cdot 0.5 - 0.918938533204673\right) \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{x \cdot \left(y + -1\right) - \left(y \cdot 0.5 - 0.918938533204673\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 61.6%

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

    if -4e-14 < y < 1.8500000000000001

    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. +-commutative100.0%

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

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

        \[\leadsto 0.918938533204673 + \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot \left(y - 1\right)\right)} \]
      4. associate-+r+100.0%

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

        \[\leadsto \color{blue}{\left(0.918938533204673 - y \cdot 0.5\right)} + x \cdot \left(y - 1\right) \]
      6. associate-+l-100.0%

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

        \[\leadsto 0.918938533204673 - \left(y \cdot 0.5 - x \cdot \color{blue}{\left(y + \left(-1\right)\right)}\right) \]
      8. distribute-rgt-in100.0%

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

        \[\leadsto 0.918938533204673 - \left(y \cdot 0.5 - \left(y \cdot x + \color{blue}{-1} \cdot x\right)\right) \]
      10. neg-mul-1100.0%

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

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

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

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

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

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

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

      \[\leadsto \color{blue}{0.918938533204673 - \mathsf{fma}\left(y, 0.5 - x, x\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in y around 0 99.5%

      \[\leadsto 0.918938533204673 - \color{blue}{x} \]
  3. Recombined 4 regimes into one program.
  4. Final simplification83.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -9.5 \cdot 10^{+258}:\\ \;\;\;\;y \cdot -0.5\\ \mathbf{elif}\;y \leq -3.6 \cdot 10^{+246}:\\ \;\;\;\;y \cdot x\\ \mathbf{elif}\;y \leq -2.25 \cdot 10^{+198}:\\ \;\;\;\;y \cdot -0.5\\ \mathbf{elif}\;y \leq -4 \cdot 10^{-14}:\\ \;\;\;\;x \cdot \left(y + -1\right)\\ \mathbf{elif}\;y \leq 1.85:\\ \;\;\;\;0.918938533204673 - x\\ \mathbf{elif}\;y \leq 1.5 \cdot 10^{+147} \lor \neg \left(y \leq 5.6 \cdot 10^{+200}\right):\\ \;\;\;\;y \cdot -0.5\\ \mathbf{else}:\\ \;\;\;\;y \cdot x\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 97.8% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -1.35:\\ \;\;\;\;y \cdot \left(x - 0.5\right)\\ \mathbf{elif}\;y \leq 1.75:\\ \;\;\;\;0.918938533204673 - x\\ \mathbf{else}:\\ \;\;\;\;y \cdot x + y \cdot -0.5\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= y -1.35)
   (* y (- x 0.5))
   (if (<= y 1.75) (- 0.918938533204673 x) (+ (* y x) (* y -0.5)))))
double code(double x, double y) {
	double tmp;
	if (y <= -1.35) {
		tmp = y * (x - 0.5);
	} else if (y <= 1.75) {
		tmp = 0.918938533204673 - x;
	} else {
		tmp = (y * x) + (y * -0.5);
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: tmp
    if (y <= (-1.35d0)) then
        tmp = y * (x - 0.5d0)
    else if (y <= 1.75d0) then
        tmp = 0.918938533204673d0 - x
    else
        tmp = (y * x) + (y * (-0.5d0))
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double tmp;
	if (y <= -1.35) {
		tmp = y * (x - 0.5);
	} else if (y <= 1.75) {
		tmp = 0.918938533204673 - x;
	} else {
		tmp = (y * x) + (y * -0.5);
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if y <= -1.35:
		tmp = y * (x - 0.5)
	elif y <= 1.75:
		tmp = 0.918938533204673 - x
	else:
		tmp = (y * x) + (y * -0.5)
	return tmp
function code(x, y)
	tmp = 0.0
	if (y <= -1.35)
		tmp = Float64(y * Float64(x - 0.5));
	elseif (y <= 1.75)
		tmp = Float64(0.918938533204673 - x);
	else
		tmp = Float64(Float64(y * x) + Float64(y * -0.5));
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if (y <= -1.35)
		tmp = y * (x - 0.5);
	elseif (y <= 1.75)
		tmp = 0.918938533204673 - x;
	else
		tmp = (y * x) + (y * -0.5);
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[LessEqual[y, -1.35], N[(y * N[(x - 0.5), $MachinePrecision]), $MachinePrecision], If[LessEqual[y, 1.75], N[(0.918938533204673 - x), $MachinePrecision], N[(N[(y * x), $MachinePrecision] + N[(y * -0.5), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -1.35:\\
\;\;\;\;y \cdot \left(x - 0.5\right)\\

\mathbf{elif}\;y \leq 1.75:\\
\;\;\;\;0.918938533204673 - x\\

\mathbf{else}:\\
\;\;\;\;y \cdot x + y \cdot -0.5\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y < -1.3500000000000001

    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. associate-+l-99.9%

        \[\leadsto \color{blue}{x \cdot \left(y - 1\right) - \left(y \cdot 0.5 - 0.918938533204673\right)} \]
      2. sub-neg99.9%

        \[\leadsto x \cdot \color{blue}{\left(y + \left(-1\right)\right)} - \left(y \cdot 0.5 - 0.918938533204673\right) \]
      3. metadata-eval99.9%

        \[\leadsto x \cdot \left(y + \color{blue}{-1}\right) - \left(y \cdot 0.5 - 0.918938533204673\right) \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{x \cdot \left(y + -1\right) - \left(y \cdot 0.5 - 0.918938533204673\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in y around inf 96.2%

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

    if -1.3500000000000001 < y < 1.75

    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. +-commutative100.0%

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

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

        \[\leadsto 0.918938533204673 + \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot \left(y - 1\right)\right)} \]
      4. associate-+r+100.0%

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

        \[\leadsto \color{blue}{\left(0.918938533204673 - y \cdot 0.5\right)} + x \cdot \left(y - 1\right) \]
      6. associate-+l-100.0%

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

        \[\leadsto 0.918938533204673 - \left(y \cdot 0.5 - x \cdot \color{blue}{\left(y + \left(-1\right)\right)}\right) \]
      8. distribute-rgt-in100.0%

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

        \[\leadsto 0.918938533204673 - \left(y \cdot 0.5 - \left(y \cdot x + \color{blue}{-1} \cdot x\right)\right) \]
      10. neg-mul-1100.0%

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

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

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

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

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

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

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

      \[\leadsto \color{blue}{0.918938533204673 - \mathsf{fma}\left(y, 0.5 - x, x\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in y around 0 98.9%

      \[\leadsto 0.918938533204673 - \color{blue}{x} \]

    if 1.75 < 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. 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. Add Preprocessing
    5. Taylor expanded in y around inf 100.0%

      \[\leadsto \color{blue}{y \cdot \left(x - 0.5\right)} \]
    6. Step-by-step derivation
      1. sub-neg100.0%

        \[\leadsto y \cdot \color{blue}{\left(x + \left(-0.5\right)\right)} \]
      2. distribute-lft-in100.0%

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

        \[\leadsto y \cdot x + y \cdot \color{blue}{-0.5} \]
    7. Applied egg-rr100.0%

      \[\leadsto \color{blue}{y \cdot x + y \cdot -0.5} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification98.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -1.35:\\ \;\;\;\;y \cdot \left(x - 0.5\right)\\ \mathbf{elif}\;y \leq 1.75:\\ \;\;\;\;0.918938533204673 - x\\ \mathbf{else}:\\ \;\;\;\;y \cdot x + y \cdot -0.5\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 97.8% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -1.55 \lor \neg \left(y \leq 1.05\right):\\ \;\;\;\;y \cdot \left(x - 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.918938533204673 - x\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (or (<= y -1.55) (not (<= y 1.05)))
   (* y (- x 0.5))
   (- 0.918938533204673 x)))
double code(double x, double y) {
	double tmp;
	if ((y <= -1.55) || !(y <= 1.05)) {
		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 <= (-1.55d0)) .or. (.not. (y <= 1.05d0))) 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 <= -1.55) || !(y <= 1.05)) {
		tmp = y * (x - 0.5);
	} else {
		tmp = 0.918938533204673 - x;
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if (y <= -1.55) or not (y <= 1.05):
		tmp = y * (x - 0.5)
	else:
		tmp = 0.918938533204673 - x
	return tmp
function code(x, y)
	tmp = 0.0
	if ((y <= -1.55) || !(y <= 1.05))
		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 <= -1.55) || ~((y <= 1.05)))
		tmp = y * (x - 0.5);
	else
		tmp = 0.918938533204673 - x;
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[Or[LessEqual[y, -1.55], N[Not[LessEqual[y, 1.05]], $MachinePrecision]], N[(y * N[(x - 0.5), $MachinePrecision]), $MachinePrecision], N[(0.918938533204673 - x), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -1.55 \lor \neg \left(y \leq 1.05\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 < -1.55000000000000004 or 1.05000000000000004 < 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. 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. Add Preprocessing
    5. Taylor expanded in y around inf 98.1%

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

    if -1.55000000000000004 < y < 1.05000000000000004

    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. +-commutative100.0%

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

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

        \[\leadsto 0.918938533204673 + \color{blue}{\left(\left(-y\right) \cdot 0.5 + x \cdot \left(y - 1\right)\right)} \]
      4. associate-+r+100.0%

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

        \[\leadsto \color{blue}{\left(0.918938533204673 - y \cdot 0.5\right)} + x \cdot \left(y - 1\right) \]
      6. associate-+l-100.0%

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

        \[\leadsto 0.918938533204673 - \left(y \cdot 0.5 - x \cdot \color{blue}{\left(y + \left(-1\right)\right)}\right) \]
      8. distribute-rgt-in100.0%

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

        \[\leadsto 0.918938533204673 - \left(y \cdot 0.5 - \left(y \cdot x + \color{blue}{-1} \cdot x\right)\right) \]
      10. neg-mul-1100.0%

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

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

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

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

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

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

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

      \[\leadsto \color{blue}{0.918938533204673 - \mathsf{fma}\left(y, 0.5 - x, x\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in y around 0 98.9%

      \[\leadsto 0.918938533204673 - \color{blue}{x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -1.55 \lor \neg \left(y \leq 1.05\right):\\ \;\;\;\;y \cdot \left(x - 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;0.918938533204673 - x\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 49.5% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -0.5 \lor \neg \left(x \leq 7.2 \cdot 10^{-15}\right):\\ \;\;\;\;y \cdot x\\ \mathbf{else}:\\ \;\;\;\;y \cdot -0.5\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (or (<= x -0.5) (not (<= x 7.2e-15))) (* y x) (* y -0.5)))
double code(double x, double y) {
	double tmp;
	if ((x <= -0.5) || !(x <= 7.2e-15)) {
		tmp = y * x;
	} else {
		tmp = y * -0.5;
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: tmp
    if ((x <= (-0.5d0)) .or. (.not. (x <= 7.2d-15))) then
        tmp = y * x
    else
        tmp = y * (-0.5d0)
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double tmp;
	if ((x <= -0.5) || !(x <= 7.2e-15)) {
		tmp = y * x;
	} else {
		tmp = y * -0.5;
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if (x <= -0.5) or not (x <= 7.2e-15):
		tmp = y * x
	else:
		tmp = y * -0.5
	return tmp
function code(x, y)
	tmp = 0.0
	if ((x <= -0.5) || !(x <= 7.2e-15))
		tmp = Float64(y * x);
	else
		tmp = Float64(y * -0.5);
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if ((x <= -0.5) || ~((x <= 7.2e-15)))
		tmp = y * x;
	else
		tmp = y * -0.5;
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[Or[LessEqual[x, -0.5], N[Not[LessEqual[x, 7.2e-15]], $MachinePrecision]], N[(y * x), $MachinePrecision], N[(y * -0.5), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -0.5 \lor \neg \left(x \leq 7.2 \cdot 10^{-15}\right):\\
\;\;\;\;y \cdot x\\

\mathbf{else}:\\
\;\;\;\;y \cdot -0.5\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -0.5 or 7.2000000000000002e-15 < 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. associate-+l-99.9%

        \[\leadsto \color{blue}{x \cdot \left(y - 1\right) - \left(y \cdot 0.5 - 0.918938533204673\right)} \]
      2. sub-neg99.9%

        \[\leadsto x \cdot \color{blue}{\left(y + \left(-1\right)\right)} - \left(y \cdot 0.5 - 0.918938533204673\right) \]
      3. metadata-eval99.9%

        \[\leadsto x \cdot \left(y + \color{blue}{-1}\right) - \left(y \cdot 0.5 - 0.918938533204673\right) \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{x \cdot \left(y + -1\right) - \left(y \cdot 0.5 - 0.918938533204673\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in y around inf 54.9%

      \[\leadsto \color{blue}{y \cdot \left(x - 0.5\right)} \]
    6. Taylor expanded in x around inf 53.4%

      \[\leadsto \color{blue}{x \cdot y} \]
    7. Step-by-step derivation
      1. *-commutative53.4%

        \[\leadsto \color{blue}{y \cdot x} \]
    8. Simplified53.4%

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

    if -0.5 < x < 7.2000000000000002e-15

    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. Add Preprocessing
    5. Taylor expanded in y around inf 49.2%

      \[\leadsto \color{blue}{y \cdot \left(x - 0.5\right)} \]
    6. Taylor expanded in x around 0 48.9%

      \[\leadsto \color{blue}{-0.5 \cdot y} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification51.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -0.5 \lor \neg \left(x \leq 7.2 \cdot 10^{-15}\right):\\ \;\;\;\;y \cdot x\\ \mathbf{else}:\\ \;\;\;\;y \cdot -0.5\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 100.0% accurate, 1.0× speedup?

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

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

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

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

Alternative 8: 26.5% accurate, 3.7× speedup?

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

\\
y \cdot -0.5
\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. 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. Add Preprocessing
  5. Taylor expanded in y around inf 51.9%

    \[\leadsto \color{blue}{y \cdot \left(x - 0.5\right)} \]
  6. Taylor expanded in x around 0 27.0%

    \[\leadsto \color{blue}{-0.5 \cdot y} \]
  7. Final simplification27.0%

    \[\leadsto y \cdot -0.5 \]
  8. Add Preprocessing

Reproduce

?
herbie shell --seed 2024027 
(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))