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

Percentage Accurate: 100.0% → 100.0%
Time: 7.7s
Alternatives: 10
Speedup: 1.5×

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 10 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. Add Preprocessing
  3. Final simplification100.0%

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

Alternative 2: 49.4% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := x \cdot \left(y + -1\right) - y \cdot 0.5\\ \mathbf{if}\;t\_0 \leq -1000:\\ \;\;\;\;-x\\ \mathbf{elif}\;t\_0 \leq 0.004:\\ \;\;\;\;0.918938533204673\\ \mathbf{else}:\\ \;\;\;\;-x\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (- (* x (+ y -1.0)) (* y 0.5))))
   (if (<= t_0 -1000.0) (- x) (if (<= t_0 0.004) 0.918938533204673 (- x)))))
double code(double x, double y) {
	double t_0 = (x * (y + -1.0)) - (y * 0.5);
	double tmp;
	if (t_0 <= -1000.0) {
		tmp = -x;
	} else if (t_0 <= 0.004) {
		tmp = 0.918938533204673;
	} else {
		tmp = -x;
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (x * (y + (-1.0d0))) - (y * 0.5d0)
    if (t_0 <= (-1000.0d0)) then
        tmp = -x
    else if (t_0 <= 0.004d0) then
        tmp = 0.918938533204673d0
    else
        tmp = -x
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double t_0 = (x * (y + -1.0)) - (y * 0.5);
	double tmp;
	if (t_0 <= -1000.0) {
		tmp = -x;
	} else if (t_0 <= 0.004) {
		tmp = 0.918938533204673;
	} else {
		tmp = -x;
	}
	return tmp;
}
def code(x, y):
	t_0 = (x * (y + -1.0)) - (y * 0.5)
	tmp = 0
	if t_0 <= -1000.0:
		tmp = -x
	elif t_0 <= 0.004:
		tmp = 0.918938533204673
	else:
		tmp = -x
	return tmp
function code(x, y)
	t_0 = Float64(Float64(x * Float64(y + -1.0)) - Float64(y * 0.5))
	tmp = 0.0
	if (t_0 <= -1000.0)
		tmp = Float64(-x);
	elseif (t_0 <= 0.004)
		tmp = 0.918938533204673;
	else
		tmp = Float64(-x);
	end
	return tmp
end
function tmp_2 = code(x, y)
	t_0 = (x * (y + -1.0)) - (y * 0.5);
	tmp = 0.0;
	if (t_0 <= -1000.0)
		tmp = -x;
	elseif (t_0 <= 0.004)
		tmp = 0.918938533204673;
	else
		tmp = -x;
	end
	tmp_2 = tmp;
end
code[x_, y_] := Block[{t$95$0 = N[(N[(x * N[(y + -1.0), $MachinePrecision]), $MachinePrecision] - N[(y * 0.5), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -1000.0], (-x), If[LessEqual[t$95$0, 0.004], 0.918938533204673, (-x)]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := x \cdot \left(y + -1\right) - y \cdot 0.5\\
\mathbf{if}\;t\_0 \leq -1000:\\
\;\;\;\;-x\\

\mathbf{elif}\;t\_0 \leq 0.004:\\
\;\;\;\;0.918938533204673\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (*.f64 x (-.f64 y #s(literal 1 binary64))) (*.f64 y #s(literal 1/2 binary64))) < -1e3 or 0.0040000000000000001 < (-.f64 (*.f64 x (-.f64 y #s(literal 1 binary64))) (*.f64 y #s(literal 1/2 binary64)))

    1. Initial program 100.0%

      \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
    2. Add Preprocessing
    3. Taylor expanded in y around 0

      \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000} + -1 \cdot x} \]
    4. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \frac{918938533204673}{1000000000000000} + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)} \]
      2. unsub-negN/A

        \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000} - x} \]
      3. lower--.f6437.3

        \[\leadsto \color{blue}{0.918938533204673 - x} \]
    5. Applied rewrites37.3%

      \[\leadsto \color{blue}{0.918938533204673 - x} \]
    6. Taylor expanded in x around inf

      \[\leadsto \color{blue}{-1 \cdot x} \]
    7. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \color{blue}{\mathsf{neg}\left(x\right)} \]
      2. lower-neg.f6435.9

        \[\leadsto \color{blue}{-x} \]
    8. Applied rewrites35.9%

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

    if -1e3 < (-.f64 (*.f64 x (-.f64 y #s(literal 1 binary64))) (*.f64 y #s(literal 1/2 binary64))) < 0.0040000000000000001

    1. Initial program 100.0%

      \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
    2. Add Preprocessing
    3. Taylor expanded in y around 0

      \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000} + -1 \cdot x} \]
    4. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \frac{918938533204673}{1000000000000000} + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)} \]
      2. unsub-negN/A

        \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000} - x} \]
      3. lower--.f6499.1

        \[\leadsto \color{blue}{0.918938533204673 - x} \]
    5. Applied rewrites99.1%

      \[\leadsto \color{blue}{0.918938533204673 - x} \]
    6. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000}} \]
    7. Step-by-step derivation
      1. Applied rewrites96.5%

        \[\leadsto \color{blue}{0.918938533204673} \]
    8. Recombined 2 regimes into one program.
    9. Final simplification53.7%

      \[\leadsto \begin{array}{l} \mathbf{if}\;x \cdot \left(y + -1\right) - y \cdot 0.5 \leq -1000:\\ \;\;\;\;-x\\ \mathbf{elif}\;x \cdot \left(y + -1\right) - y \cdot 0.5 \leq 0.004:\\ \;\;\;\;0.918938533204673\\ \mathbf{else}:\\ \;\;\;\;-x\\ \end{array} \]
    10. Add Preprocessing

    Alternative 3: 98.6% accurate, 0.9× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := x \cdot y - x\\ \mathbf{if}\;x \leq -4500000:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x \leq 2.7 \cdot 10^{+14}:\\ \;\;\;\;0.918938533204673 - \mathsf{fma}\left(y, 0.5, x\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
    (FPCore (x y)
     :precision binary64
     (let* ((t_0 (- (* x y) x)))
       (if (<= x -4500000.0)
         t_0
         (if (<= x 2.7e+14) (- 0.918938533204673 (fma y 0.5 x)) t_0))))
    double code(double x, double y) {
    	double t_0 = (x * y) - x;
    	double tmp;
    	if (x <= -4500000.0) {
    		tmp = t_0;
    	} else if (x <= 2.7e+14) {
    		tmp = 0.918938533204673 - fma(y, 0.5, x);
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    function code(x, y)
    	t_0 = Float64(Float64(x * y) - x)
    	tmp = 0.0
    	if (x <= -4500000.0)
    		tmp = t_0;
    	elseif (x <= 2.7e+14)
    		tmp = Float64(0.918938533204673 - fma(y, 0.5, x));
    	else
    		tmp = t_0;
    	end
    	return tmp
    end
    
    code[x_, y_] := Block[{t$95$0 = N[(N[(x * y), $MachinePrecision] - x), $MachinePrecision]}, If[LessEqual[x, -4500000.0], t$95$0, If[LessEqual[x, 2.7e+14], N[(0.918938533204673 - N[(y * 0.5 + x), $MachinePrecision]), $MachinePrecision], t$95$0]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := x \cdot y - x\\
    \mathbf{if}\;x \leq -4500000:\\
    \;\;\;\;t\_0\\
    
    \mathbf{elif}\;x \leq 2.7 \cdot 10^{+14}:\\
    \;\;\;\;0.918938533204673 - \mathsf{fma}\left(y, 0.5, x\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;t\_0\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if x < -4.5e6 or 2.7e14 < x

      1. Initial program 100.0%

        \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
      2. Add Preprocessing
      3. Taylor expanded in x around inf

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

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

          \[\leadsto x \cdot \left(y + \color{blue}{-1}\right) \]
        3. distribute-lft-inN/A

          \[\leadsto \color{blue}{x \cdot y + x \cdot -1} \]
        4. *-commutativeN/A

          \[\leadsto x \cdot y + \color{blue}{-1 \cdot x} \]
        5. mul-1-negN/A

          \[\leadsto x \cdot y + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)} \]
        6. unsub-negN/A

          \[\leadsto \color{blue}{x \cdot y - x} \]
        7. lower--.f64N/A

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

          \[\leadsto \color{blue}{y \cdot x} - x \]
        9. lower-*.f64100.0

          \[\leadsto \color{blue}{y \cdot x} - x \]
      5. Applied rewrites100.0%

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

      if -4.5e6 < x < 2.7e14

      1. Initial program 100.0%

        \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
      2. Add Preprocessing
      3. Taylor expanded in x around 0

        \[\leadsto \color{blue}{\left(\frac{918938533204673}{1000000000000000} + x \cdot \left(y - 1\right)\right) - \frac{1}{2} \cdot y} \]
      4. Applied rewrites100.0%

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

        \[\leadsto \frac{918938533204673}{1000000000000000} - \mathsf{fma}\left(y, \color{blue}{\frac{1}{2}}, x\right) \]
      6. Step-by-step derivation
        1. Applied rewrites97.6%

          \[\leadsto 0.918938533204673 - \mathsf{fma}\left(y, \color{blue}{0.5}, x\right) \]
      7. Recombined 2 regimes into one program.
      8. Final simplification98.7%

        \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -4500000:\\ \;\;\;\;x \cdot y - x\\ \mathbf{elif}\;x \leq 2.7 \cdot 10^{+14}:\\ \;\;\;\;0.918938533204673 - \mathsf{fma}\left(y, 0.5, x\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot y - x\\ \end{array} \]
      9. Add Preprocessing

      Alternative 4: 97.9% accurate, 1.0× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} t_0 := y \cdot \left(x + -0.5\right)\\ \mathbf{if}\;y \leq -1.35:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y \leq 1.05:\\ \;\;\;\;0.918938533204673 - x\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
      (FPCore (x y)
       :precision binary64
       (let* ((t_0 (* y (+ x -0.5))))
         (if (<= y -1.35) t_0 (if (<= y 1.05) (- 0.918938533204673 x) t_0))))
      double code(double x, double y) {
      	double t_0 = y * (x + -0.5);
      	double tmp;
      	if (y <= -1.35) {
      		tmp = t_0;
      	} else if (y <= 1.05) {
      		tmp = 0.918938533204673 - x;
      	} else {
      		tmp = t_0;
      	}
      	return tmp;
      }
      
      real(8) function code(x, y)
          real(8), intent (in) :: x
          real(8), intent (in) :: y
          real(8) :: t_0
          real(8) :: tmp
          t_0 = y * (x + (-0.5d0))
          if (y <= (-1.35d0)) then
              tmp = t_0
          else if (y <= 1.05d0) then
              tmp = 0.918938533204673d0 - x
          else
              tmp = t_0
          end if
          code = tmp
      end function
      
      public static double code(double x, double y) {
      	double t_0 = y * (x + -0.5);
      	double tmp;
      	if (y <= -1.35) {
      		tmp = t_0;
      	} else if (y <= 1.05) {
      		tmp = 0.918938533204673 - x;
      	} else {
      		tmp = t_0;
      	}
      	return tmp;
      }
      
      def code(x, y):
      	t_0 = y * (x + -0.5)
      	tmp = 0
      	if y <= -1.35:
      		tmp = t_0
      	elif y <= 1.05:
      		tmp = 0.918938533204673 - x
      	else:
      		tmp = t_0
      	return tmp
      
      function code(x, y)
      	t_0 = Float64(y * Float64(x + -0.5))
      	tmp = 0.0
      	if (y <= -1.35)
      		tmp = t_0;
      	elseif (y <= 1.05)
      		tmp = Float64(0.918938533204673 - x);
      	else
      		tmp = t_0;
      	end
      	return tmp
      end
      
      function tmp_2 = code(x, y)
      	t_0 = y * (x + -0.5);
      	tmp = 0.0;
      	if (y <= -1.35)
      		tmp = t_0;
      	elseif (y <= 1.05)
      		tmp = 0.918938533204673 - x;
      	else
      		tmp = t_0;
      	end
      	tmp_2 = tmp;
      end
      
      code[x_, y_] := Block[{t$95$0 = N[(y * N[(x + -0.5), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[y, -1.35], t$95$0, If[LessEqual[y, 1.05], N[(0.918938533204673 - x), $MachinePrecision], t$95$0]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      t_0 := y \cdot \left(x + -0.5\right)\\
      \mathbf{if}\;y \leq -1.35:\\
      \;\;\;\;t\_0\\
      
      \mathbf{elif}\;y \leq 1.05:\\
      \;\;\;\;0.918938533204673 - x\\
      
      \mathbf{else}:\\
      \;\;\;\;t\_0\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if y < -1.3500000000000001 or 1.05000000000000004 < y

        1. Initial program 100.0%

          \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
        2. Add Preprocessing
        3. Taylor expanded in y around inf

          \[\leadsto \color{blue}{y \cdot \left(x - \frac{1}{2}\right)} \]
        4. Step-by-step derivation
          1. sub-negN/A

            \[\leadsto y \cdot \color{blue}{\left(x + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)\right)} \]
          2. remove-double-negN/A

            \[\leadsto y \cdot \left(\color{blue}{\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right)} + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)\right) \]
          3. mul-1-negN/A

            \[\leadsto y \cdot \left(\left(\mathsf{neg}\left(\color{blue}{-1 \cdot x}\right)\right) + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)\right) \]
          4. distribute-neg-inN/A

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

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

            \[\leadsto \color{blue}{y \cdot \left(\mathsf{neg}\left(\left(\frac{1}{2} + -1 \cdot x\right)\right)\right)} \]
          7. distribute-neg-inN/A

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

            \[\leadsto y \cdot \left(\color{blue}{\frac{-1}{2}} + \left(\mathsf{neg}\left(-1 \cdot x\right)\right)\right) \]
          9. mul-1-negN/A

            \[\leadsto y \cdot \left(\frac{-1}{2} + \left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right)\right)\right) \]
          10. remove-double-negN/A

            \[\leadsto y \cdot \left(\frac{-1}{2} + \color{blue}{x}\right) \]
          11. lower-+.f6498.1

            \[\leadsto y \cdot \color{blue}{\left(-0.5 + x\right)} \]
        5. Applied rewrites98.1%

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

        if -1.3500000000000001 < y < 1.05000000000000004

        1. Initial program 100.0%

          \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
        2. Add Preprocessing
        3. Taylor expanded in y around 0

          \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000} + -1 \cdot x} \]
        4. Step-by-step derivation
          1. mul-1-negN/A

            \[\leadsto \frac{918938533204673}{1000000000000000} + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)} \]
          2. unsub-negN/A

            \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000} - x} \]
          3. lower--.f6498.2

            \[\leadsto \color{blue}{0.918938533204673 - x} \]
        5. Applied rewrites98.2%

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

        \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -1.35:\\ \;\;\;\;y \cdot \left(x + -0.5\right)\\ \mathbf{elif}\;y \leq 1.05:\\ \;\;\;\;0.918938533204673 - x\\ \mathbf{else}:\\ \;\;\;\;y \cdot \left(x + -0.5\right)\\ \end{array} \]
      5. Add Preprocessing

      Alternative 5: 74.3% accurate, 1.1× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -8.6:\\ \;\;\;\;x \cdot y\\ \mathbf{elif}\;y \leq 0.0148:\\ \;\;\;\;0.918938533204673 - x\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(-0.5, y, 0.918938533204673\right)\\ \end{array} \end{array} \]
      (FPCore (x y)
       :precision binary64
       (if (<= y -8.6)
         (* x y)
         (if (<= y 0.0148) (- 0.918938533204673 x) (fma -0.5 y 0.918938533204673))))
      double code(double x, double y) {
      	double tmp;
      	if (y <= -8.6) {
      		tmp = x * y;
      	} else if (y <= 0.0148) {
      		tmp = 0.918938533204673 - x;
      	} else {
      		tmp = fma(-0.5, y, 0.918938533204673);
      	}
      	return tmp;
      }
      
      function code(x, y)
      	tmp = 0.0
      	if (y <= -8.6)
      		tmp = Float64(x * y);
      	elseif (y <= 0.0148)
      		tmp = Float64(0.918938533204673 - x);
      	else
      		tmp = fma(-0.5, y, 0.918938533204673);
      	end
      	return tmp
      end
      
      code[x_, y_] := If[LessEqual[y, -8.6], N[(x * y), $MachinePrecision], If[LessEqual[y, 0.0148], N[(0.918938533204673 - x), $MachinePrecision], N[(-0.5 * y + 0.918938533204673), $MachinePrecision]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;y \leq -8.6:\\
      \;\;\;\;x \cdot y\\
      
      \mathbf{elif}\;y \leq 0.0148:\\
      \;\;\;\;0.918938533204673 - x\\
      
      \mathbf{else}:\\
      \;\;\;\;\mathsf{fma}\left(-0.5, y, 0.918938533204673\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 3 regimes
      2. if y < -8.59999999999999964

        1. Initial program 100.0%

          \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
        2. Add Preprocessing
        3. Taylor expanded in y around inf

          \[\leadsto \color{blue}{y \cdot \left(x - \frac{1}{2}\right)} \]
        4. Step-by-step derivation
          1. sub-negN/A

            \[\leadsto y \cdot \color{blue}{\left(x + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)\right)} \]
          2. remove-double-negN/A

            \[\leadsto y \cdot \left(\color{blue}{\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right)} + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)\right) \]
          3. mul-1-negN/A

            \[\leadsto y \cdot \left(\left(\mathsf{neg}\left(\color{blue}{-1 \cdot x}\right)\right) + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)\right) \]
          4. distribute-neg-inN/A

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

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

            \[\leadsto \color{blue}{y \cdot \left(\mathsf{neg}\left(\left(\frac{1}{2} + -1 \cdot x\right)\right)\right)} \]
          7. distribute-neg-inN/A

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

            \[\leadsto y \cdot \left(\color{blue}{\frac{-1}{2}} + \left(\mathsf{neg}\left(-1 \cdot x\right)\right)\right) \]
          9. mul-1-negN/A

            \[\leadsto y \cdot \left(\frac{-1}{2} + \left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right)\right)\right) \]
          10. remove-double-negN/A

            \[\leadsto y \cdot \left(\frac{-1}{2} + \color{blue}{x}\right) \]
          11. lower-+.f6498.6

            \[\leadsto y \cdot \color{blue}{\left(-0.5 + x\right)} \]
        5. Applied rewrites98.6%

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

          \[\leadsto \color{blue}{x \cdot y} \]
        7. Step-by-step derivation
          1. lower-*.f6457.3

            \[\leadsto \color{blue}{x \cdot y} \]
        8. Applied rewrites57.3%

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

        if -8.59999999999999964 < y < 0.014800000000000001

        1. Initial program 100.0%

          \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
        2. Add Preprocessing
        3. Taylor expanded in y around 0

          \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000} + -1 \cdot x} \]
        4. Step-by-step derivation
          1. mul-1-negN/A

            \[\leadsto \frac{918938533204673}{1000000000000000} + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)} \]
          2. unsub-negN/A

            \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000} - x} \]
          3. lower--.f6498.2

            \[\leadsto \color{blue}{0.918938533204673 - x} \]
        5. Applied rewrites98.2%

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

        if 0.014800000000000001 < y

        1. Initial program 100.0%

          \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
        2. Add Preprocessing
        3. Taylor expanded in x around 0

          \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000} - \frac{1}{2} \cdot y} \]
        4. Step-by-step derivation
          1. sub-negN/A

            \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000} + \left(\mathsf{neg}\left(\frac{1}{2} \cdot y\right)\right)} \]
          2. +-commutativeN/A

            \[\leadsto \color{blue}{\left(\mathsf{neg}\left(\frac{1}{2} \cdot y\right)\right) + \frac{918938533204673}{1000000000000000}} \]
          3. distribute-lft-neg-inN/A

            \[\leadsto \color{blue}{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot y} + \frac{918938533204673}{1000000000000000} \]
          4. metadata-evalN/A

            \[\leadsto \color{blue}{\frac{-1}{2}} \cdot y + \frac{918938533204673}{1000000000000000} \]
          5. lower-fma.f6451.2

            \[\leadsto \color{blue}{\mathsf{fma}\left(-0.5, y, 0.918938533204673\right)} \]
        5. Applied rewrites51.2%

          \[\leadsto \color{blue}{\mathsf{fma}\left(-0.5, y, 0.918938533204673\right)} \]
      3. Recombined 3 regimes into one program.
      4. Add Preprocessing

      Alternative 6: 74.0% accurate, 1.1× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -8.6:\\ \;\;\;\;x \cdot y\\ \mathbf{elif}\;y \leq 1.82:\\ \;\;\;\;0.918938533204673 - x\\ \mathbf{else}:\\ \;\;\;\;y \cdot -0.5\\ \end{array} \end{array} \]
      (FPCore (x y)
       :precision binary64
       (if (<= y -8.6) (* x y) (if (<= y 1.82) (- 0.918938533204673 x) (* y -0.5))))
      double code(double x, double y) {
      	double tmp;
      	if (y <= -8.6) {
      		tmp = x * y;
      	} else if (y <= 1.82) {
      		tmp = 0.918938533204673 - 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 (y <= (-8.6d0)) then
              tmp = x * y
          else if (y <= 1.82d0) then
              tmp = 0.918938533204673d0 - x
          else
              tmp = y * (-0.5d0)
          end if
          code = tmp
      end function
      
      public static double code(double x, double y) {
      	double tmp;
      	if (y <= -8.6) {
      		tmp = x * y;
      	} else if (y <= 1.82) {
      		tmp = 0.918938533204673 - x;
      	} else {
      		tmp = y * -0.5;
      	}
      	return tmp;
      }
      
      def code(x, y):
      	tmp = 0
      	if y <= -8.6:
      		tmp = x * y
      	elif y <= 1.82:
      		tmp = 0.918938533204673 - x
      	else:
      		tmp = y * -0.5
      	return tmp
      
      function code(x, y)
      	tmp = 0.0
      	if (y <= -8.6)
      		tmp = Float64(x * y);
      	elseif (y <= 1.82)
      		tmp = Float64(0.918938533204673 - x);
      	else
      		tmp = Float64(y * -0.5);
      	end
      	return tmp
      end
      
      function tmp_2 = code(x, y)
      	tmp = 0.0;
      	if (y <= -8.6)
      		tmp = x * y;
      	elseif (y <= 1.82)
      		tmp = 0.918938533204673 - x;
      	else
      		tmp = y * -0.5;
      	end
      	tmp_2 = tmp;
      end
      
      code[x_, y_] := If[LessEqual[y, -8.6], N[(x * y), $MachinePrecision], If[LessEqual[y, 1.82], N[(0.918938533204673 - x), $MachinePrecision], N[(y * -0.5), $MachinePrecision]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;y \leq -8.6:\\
      \;\;\;\;x \cdot y\\
      
      \mathbf{elif}\;y \leq 1.82:\\
      \;\;\;\;0.918938533204673 - x\\
      
      \mathbf{else}:\\
      \;\;\;\;y \cdot -0.5\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 3 regimes
      2. if y < -8.59999999999999964

        1. Initial program 100.0%

          \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
        2. Add Preprocessing
        3. Taylor expanded in y around inf

          \[\leadsto \color{blue}{y \cdot \left(x - \frac{1}{2}\right)} \]
        4. Step-by-step derivation
          1. sub-negN/A

            \[\leadsto y \cdot \color{blue}{\left(x + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)\right)} \]
          2. remove-double-negN/A

            \[\leadsto y \cdot \left(\color{blue}{\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right)} + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)\right) \]
          3. mul-1-negN/A

            \[\leadsto y \cdot \left(\left(\mathsf{neg}\left(\color{blue}{-1 \cdot x}\right)\right) + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)\right) \]
          4. distribute-neg-inN/A

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

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

            \[\leadsto \color{blue}{y \cdot \left(\mathsf{neg}\left(\left(\frac{1}{2} + -1 \cdot x\right)\right)\right)} \]
          7. distribute-neg-inN/A

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

            \[\leadsto y \cdot \left(\color{blue}{\frac{-1}{2}} + \left(\mathsf{neg}\left(-1 \cdot x\right)\right)\right) \]
          9. mul-1-negN/A

            \[\leadsto y \cdot \left(\frac{-1}{2} + \left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right)\right)\right) \]
          10. remove-double-negN/A

            \[\leadsto y \cdot \left(\frac{-1}{2} + \color{blue}{x}\right) \]
          11. lower-+.f6498.6

            \[\leadsto y \cdot \color{blue}{\left(-0.5 + x\right)} \]
        5. Applied rewrites98.6%

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

          \[\leadsto \color{blue}{x \cdot y} \]
        7. Step-by-step derivation
          1. lower-*.f6457.3

            \[\leadsto \color{blue}{x \cdot y} \]
        8. Applied rewrites57.3%

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

        if -8.59999999999999964 < y < 1.82000000000000006

        1. Initial program 100.0%

          \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
        2. Add Preprocessing
        3. Taylor expanded in y around 0

          \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000} + -1 \cdot x} \]
        4. Step-by-step derivation
          1. mul-1-negN/A

            \[\leadsto \frac{918938533204673}{1000000000000000} + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)} \]
          2. unsub-negN/A

            \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000} - x} \]
          3. lower--.f6498.2

            \[\leadsto \color{blue}{0.918938533204673 - x} \]
        5. Applied rewrites98.2%

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

        if 1.82000000000000006 < y

        1. Initial program 100.0%

          \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
        2. Add Preprocessing
        3. Taylor expanded in x around 0

          \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000} - \frac{1}{2} \cdot y} \]
        4. Step-by-step derivation
          1. sub-negN/A

            \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000} + \left(\mathsf{neg}\left(\frac{1}{2} \cdot y\right)\right)} \]
          2. +-commutativeN/A

            \[\leadsto \color{blue}{\left(\mathsf{neg}\left(\frac{1}{2} \cdot y\right)\right) + \frac{918938533204673}{1000000000000000}} \]
          3. distribute-lft-neg-inN/A

            \[\leadsto \color{blue}{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot y} + \frac{918938533204673}{1000000000000000} \]
          4. metadata-evalN/A

            \[\leadsto \color{blue}{\frac{-1}{2}} \cdot y + \frac{918938533204673}{1000000000000000} \]
          5. lower-fma.f6451.2

            \[\leadsto \color{blue}{\mathsf{fma}\left(-0.5, y, 0.918938533204673\right)} \]
        5. Applied rewrites51.2%

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

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

            \[\leadsto \color{blue}{y \cdot \frac{-1}{2}} \]
          2. lower-*.f6449.6

            \[\leadsto \color{blue}{y \cdot -0.5} \]
        8. Applied rewrites49.6%

          \[\leadsto \color{blue}{y \cdot -0.5} \]
      3. Recombined 3 regimes into one program.
      4. Add Preprocessing

      Alternative 7: 73.5% accurate, 1.1× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -8.6:\\ \;\;\;\;x \cdot y\\ \mathbf{elif}\;y \leq 1.05:\\ \;\;\;\;0.918938533204673 - x\\ \mathbf{else}:\\ \;\;\;\;x \cdot y\\ \end{array} \end{array} \]
      (FPCore (x y)
       :precision binary64
       (if (<= y -8.6) (* x y) (if (<= y 1.05) (- 0.918938533204673 x) (* x y))))
      double code(double x, double y) {
      	double tmp;
      	if (y <= -8.6) {
      		tmp = x * y;
      	} else if (y <= 1.05) {
      		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 <= (-8.6d0)) then
              tmp = x * y
          else if (y <= 1.05d0) 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 <= -8.6) {
      		tmp = x * y;
      	} else if (y <= 1.05) {
      		tmp = 0.918938533204673 - x;
      	} else {
      		tmp = x * y;
      	}
      	return tmp;
      }
      
      def code(x, y):
      	tmp = 0
      	if y <= -8.6:
      		tmp = x * y
      	elif y <= 1.05:
      		tmp = 0.918938533204673 - x
      	else:
      		tmp = x * y
      	return tmp
      
      function code(x, y)
      	tmp = 0.0
      	if (y <= -8.6)
      		tmp = Float64(x * y);
      	elseif (y <= 1.05)
      		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 <= -8.6)
      		tmp = x * y;
      	elseif (y <= 1.05)
      		tmp = 0.918938533204673 - x;
      	else
      		tmp = x * y;
      	end
      	tmp_2 = tmp;
      end
      
      code[x_, y_] := If[LessEqual[y, -8.6], N[(x * y), $MachinePrecision], If[LessEqual[y, 1.05], N[(0.918938533204673 - x), $MachinePrecision], N[(x * y), $MachinePrecision]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;y \leq -8.6:\\
      \;\;\;\;x \cdot y\\
      
      \mathbf{elif}\;y \leq 1.05:\\
      \;\;\;\;0.918938533204673 - x\\
      
      \mathbf{else}:\\
      \;\;\;\;x \cdot y\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if y < -8.59999999999999964 or 1.05000000000000004 < y

        1. Initial program 100.0%

          \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
        2. Add Preprocessing
        3. Taylor expanded in y around inf

          \[\leadsto \color{blue}{y \cdot \left(x - \frac{1}{2}\right)} \]
        4. Step-by-step derivation
          1. sub-negN/A

            \[\leadsto y \cdot \color{blue}{\left(x + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)\right)} \]
          2. remove-double-negN/A

            \[\leadsto y \cdot \left(\color{blue}{\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right)} + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)\right) \]
          3. mul-1-negN/A

            \[\leadsto y \cdot \left(\left(\mathsf{neg}\left(\color{blue}{-1 \cdot x}\right)\right) + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)\right) \]
          4. distribute-neg-inN/A

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

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

            \[\leadsto \color{blue}{y \cdot \left(\mathsf{neg}\left(\left(\frac{1}{2} + -1 \cdot x\right)\right)\right)} \]
          7. distribute-neg-inN/A

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

            \[\leadsto y \cdot \left(\color{blue}{\frac{-1}{2}} + \left(\mathsf{neg}\left(-1 \cdot x\right)\right)\right) \]
          9. mul-1-negN/A

            \[\leadsto y \cdot \left(\frac{-1}{2} + \left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right)\right)\right) \]
          10. remove-double-negN/A

            \[\leadsto y \cdot \left(\frac{-1}{2} + \color{blue}{x}\right) \]
          11. lower-+.f6498.1

            \[\leadsto y \cdot \color{blue}{\left(-0.5 + x\right)} \]
        5. Applied rewrites98.1%

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

          \[\leadsto \color{blue}{x \cdot y} \]
        7. Step-by-step derivation
          1. lower-*.f6452.6

            \[\leadsto \color{blue}{x \cdot y} \]
        8. Applied rewrites52.6%

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

        if -8.59999999999999964 < y < 1.05000000000000004

        1. Initial program 100.0%

          \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.918938533204673 \]
        2. Add Preprocessing
        3. Taylor expanded in y around 0

          \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000} + -1 \cdot x} \]
        4. Step-by-step derivation
          1. mul-1-negN/A

            \[\leadsto \frac{918938533204673}{1000000000000000} + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)} \]
          2. unsub-negN/A

            \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000} - x} \]
          3. lower--.f6498.2

            \[\leadsto \color{blue}{0.918938533204673 - x} \]
        5. Applied rewrites98.2%

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

      Alternative 8: 100.0% accurate, 1.5× 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. Add Preprocessing
      3. Taylor expanded in x around 0

        \[\leadsto \color{blue}{\left(\frac{918938533204673}{1000000000000000} + x \cdot \left(y - 1\right)\right) - \frac{1}{2} \cdot y} \]
      4. Applied rewrites100.0%

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

      Alternative 9: 50.6% accurate, 5.0× speedup?

      \[\begin{array}{l} \\ 0.918938533204673 - x \end{array} \]
      (FPCore (x y) :precision binary64 (- 0.918938533204673 x))
      double code(double x, double y) {
      	return 0.918938533204673 - x;
      }
      
      real(8) function code(x, y)
          real(8), intent (in) :: x
          real(8), intent (in) :: y
          code = 0.918938533204673d0 - x
      end function
      
      public static double code(double x, double y) {
      	return 0.918938533204673 - x;
      }
      
      def code(x, y):
      	return 0.918938533204673 - x
      
      function code(x, y)
      	return Float64(0.918938533204673 - x)
      end
      
      function tmp = code(x, y)
      	tmp = 0.918938533204673 - x;
      end
      
      code[x_, y_] := N[(0.918938533204673 - x), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      0.918938533204673 - x
      \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. Taylor expanded in y around 0

        \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000} + -1 \cdot x} \]
      4. Step-by-step derivation
        1. mul-1-negN/A

          \[\leadsto \frac{918938533204673}{1000000000000000} + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)} \]
        2. unsub-negN/A

          \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000} - x} \]
        3. lower--.f6455.4

          \[\leadsto \color{blue}{0.918938533204673 - x} \]
      5. Applied rewrites55.4%

        \[\leadsto \color{blue}{0.918938533204673 - x} \]
      6. Add Preprocessing

      Alternative 10: 26.3% accurate, 20.0× speedup?

      \[\begin{array}{l} \\ 0.918938533204673 \end{array} \]
      (FPCore (x y) :precision binary64 0.918938533204673)
      double code(double x, double y) {
      	return 0.918938533204673;
      }
      
      real(8) function code(x, y)
          real(8), intent (in) :: x
          real(8), intent (in) :: y
          code = 0.918938533204673d0
      end function
      
      public static double code(double x, double y) {
      	return 0.918938533204673;
      }
      
      def code(x, y):
      	return 0.918938533204673
      
      function code(x, y)
      	return 0.918938533204673
      end
      
      function tmp = code(x, y)
      	tmp = 0.918938533204673;
      end
      
      code[x_, y_] := 0.918938533204673
      
      \begin{array}{l}
      
      \\
      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. Add Preprocessing
      3. Taylor expanded in y around 0

        \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000} + -1 \cdot x} \]
      4. Step-by-step derivation
        1. mul-1-negN/A

          \[\leadsto \frac{918938533204673}{1000000000000000} + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)} \]
        2. unsub-negN/A

          \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000} - x} \]
        3. lower--.f6455.4

          \[\leadsto \color{blue}{0.918938533204673 - x} \]
      5. Applied rewrites55.4%

        \[\leadsto \color{blue}{0.918938533204673 - x} \]
      6. Taylor expanded in x around 0

        \[\leadsto \color{blue}{\frac{918938533204673}{1000000000000000}} \]
      7. Step-by-step derivation
        1. Applied rewrites30.0%

          \[\leadsto \color{blue}{0.918938533204673} \]
        2. Add Preprocessing

        Reproduce

        ?
        herbie shell --seed 2024219 
        (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))