Radioactive exchange between two surfaces

Percentage Accurate: 85.9% → 99.8%
Time: 6.0s
Alternatives: 6
Speedup: 7.4×

Specification

?
\[\begin{array}{l} \\ {x}^{4} - {y}^{4} \end{array} \]
(FPCore (x y) :precision binary64 (- (pow x 4.0) (pow y 4.0)))
double code(double x, double y) {
	return pow(x, 4.0) - pow(y, 4.0);
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x, y)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = (x ** 4.0d0) - (y ** 4.0d0)
end function
public static double code(double x, double y) {
	return Math.pow(x, 4.0) - Math.pow(y, 4.0);
}
def code(x, y):
	return math.pow(x, 4.0) - math.pow(y, 4.0)
function code(x, y)
	return Float64((x ^ 4.0) - (y ^ 4.0))
end
function tmp = code(x, y)
	tmp = (x ^ 4.0) - (y ^ 4.0);
end
code[x_, y_] := N[(N[Power[x, 4.0], $MachinePrecision] - N[Power[y, 4.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
{x}^{4} - {y}^{4}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 6 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 85.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ {x}^{4} - {y}^{4} \end{array} \]
(FPCore (x y) :precision binary64 (- (pow x 4.0) (pow y 4.0)))
double code(double x, double y) {
	return pow(x, 4.0) - pow(y, 4.0);
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x, y)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = (x ** 4.0d0) - (y ** 4.0d0)
end function
public static double code(double x, double y) {
	return Math.pow(x, 4.0) - Math.pow(y, 4.0);
}
def code(x, y):
	return math.pow(x, 4.0) - math.pow(y, 4.0)
function code(x, y)
	return Float64((x ^ 4.0) - (y ^ 4.0))
end
function tmp = code(x, y)
	tmp = (x ^ 4.0) - (y ^ 4.0);
end
code[x_, y_] := N[(N[Power[x, 4.0], $MachinePrecision] - N[Power[y, 4.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
{x}^{4} - {y}^{4}
\end{array}

Alternative 1: 99.8% accurate, 7.4× speedup?

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

\\
\mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)
\end{array}
Derivation
  1. Initial program 85.9%

    \[{x}^{4} - {y}^{4} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift--.f64N/A

      \[\leadsto \color{blue}{{x}^{4} - {y}^{4}} \]
    2. lift-pow.f64N/A

      \[\leadsto \color{blue}{{x}^{4}} - {y}^{4} \]
    3. sqr-powN/A

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

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

      \[\leadsto {x}^{\left(\frac{4}{2}\right)} \cdot {x}^{\left(\frac{4}{2}\right)} - \color{blue}{{y}^{\left(\frac{4}{2}\right)} \cdot {y}^{\left(\frac{4}{2}\right)}} \]
    6. difference-of-squaresN/A

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

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

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

      \[\leadsto \left({y}^{\color{blue}{2}} + {x}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
    10. unpow2N/A

      \[\leadsto \left(\color{blue}{y \cdot y} + {x}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
    11. lower-fma.f64N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(y, y, {x}^{\left(\frac{4}{2}\right)}\right)} \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
    12. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left(y, y, {x}^{\color{blue}{2}}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
    13. unpow2N/A

      \[\leadsto \mathsf{fma}\left(y, y, \color{blue}{x \cdot x}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
    14. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(y, y, \color{blue}{x \cdot x}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
    15. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left({x}^{\color{blue}{2}} - {y}^{\left(\frac{4}{2}\right)}\right) \]
    16. unpow2N/A

      \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(\color{blue}{x \cdot x} - {y}^{\left(\frac{4}{2}\right)}\right) \]
    17. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(x \cdot x - {y}^{\color{blue}{2}}\right) \]
    18. unpow2N/A

      \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(x \cdot x - \color{blue}{y \cdot y}\right) \]
    19. difference-of-squaresN/A

      \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
    20. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
    21. lower-+.f64N/A

      \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(\color{blue}{\left(x + y\right)} \cdot \left(x - y\right)\right) \]
    22. lower--.f6499.8

      \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(\left(x + y\right) \cdot \color{blue}{\left(x - y\right)}\right) \]
  4. Applied rewrites99.8%

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

Alternative 2: 99.6% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -2 \cdot 10^{-311}:\\ \;\;\;\;y \cdot \left(y \cdot \left(\left(-y\right) \cdot y\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(1 \cdot \left(x \cdot x\right)\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= (- (pow x 4.0) (pow y 4.0)) -2e-311)
   (* y (* y (* (- y) y)))
   (* (* 1.0 (* x x)) (* (+ x y) (- x y)))))
double code(double x, double y) {
	double tmp;
	if ((pow(x, 4.0) - pow(y, 4.0)) <= -2e-311) {
		tmp = y * (y * (-y * y));
	} else {
		tmp = (1.0 * (x * x)) * ((x + y) * (x - y));
	}
	return tmp;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x, y)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: tmp
    if (((x ** 4.0d0) - (y ** 4.0d0)) <= (-2d-311)) then
        tmp = y * (y * (-y * y))
    else
        tmp = (1.0d0 * (x * x)) * ((x + y) * (x - y))
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double tmp;
	if ((Math.pow(x, 4.0) - Math.pow(y, 4.0)) <= -2e-311) {
		tmp = y * (y * (-y * y));
	} else {
		tmp = (1.0 * (x * x)) * ((x + y) * (x - y));
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if (math.pow(x, 4.0) - math.pow(y, 4.0)) <= -2e-311:
		tmp = y * (y * (-y * y))
	else:
		tmp = (1.0 * (x * x)) * ((x + y) * (x - y))
	return tmp
function code(x, y)
	tmp = 0.0
	if (Float64((x ^ 4.0) - (y ^ 4.0)) <= -2e-311)
		tmp = Float64(y * Float64(y * Float64(Float64(-y) * y)));
	else
		tmp = Float64(Float64(1.0 * Float64(x * x)) * Float64(Float64(x + y) * Float64(x - y)));
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if (((x ^ 4.0) - (y ^ 4.0)) <= -2e-311)
		tmp = y * (y * (-y * y));
	else
		tmp = (1.0 * (x * x)) * ((x + y) * (x - y));
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[LessEqual[N[(N[Power[x, 4.0], $MachinePrecision] - N[Power[y, 4.0], $MachinePrecision]), $MachinePrecision], -2e-311], N[(y * N[(y * N[((-y) * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 * N[(x * x), $MachinePrecision]), $MachinePrecision] * N[(N[(x + y), $MachinePrecision] * N[(x - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;{x}^{4} - {y}^{4} \leq -2 \cdot 10^{-311}:\\
\;\;\;\;y \cdot \left(y \cdot \left(\left(-y\right) \cdot y\right)\right)\\

\mathbf{else}:\\
\;\;\;\;\left(1 \cdot \left(x \cdot x\right)\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (pow.f64 x #s(literal 4 binary64)) (pow.f64 y #s(literal 4 binary64))) < -1.9999999999999e-311

    1. Initial program 100.0%

      \[{x}^{4} - {y}^{4} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{-1 \cdot {y}^{4}} \]
    4. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \color{blue}{\mathsf{neg}\left({y}^{4}\right)} \]
      2. lower-neg.f64N/A

        \[\leadsto \color{blue}{-{y}^{4}} \]
      3. lower-pow.f64100.0

        \[\leadsto -\color{blue}{{y}^{4}} \]
    5. Applied rewrites100.0%

      \[\leadsto \color{blue}{-{y}^{4}} \]
    6. Step-by-step derivation
      1. Applied rewrites99.7%

        \[\leadsto \left(\left(-y\right) \cdot y\right) \cdot \color{blue}{\left(y \cdot y\right)} \]
      2. Step-by-step derivation
        1. Applied rewrites99.7%

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

        if -1.9999999999999e-311 < (-.f64 (pow.f64 x #s(literal 4 binary64)) (pow.f64 y #s(literal 4 binary64)))

        1. Initial program 76.9%

          \[{x}^{4} - {y}^{4} \]
        2. Add Preprocessing
        3. Step-by-step derivation
          1. lift--.f64N/A

            \[\leadsto \color{blue}{{x}^{4} - {y}^{4}} \]
          2. lift-pow.f64N/A

            \[\leadsto \color{blue}{{x}^{4}} - {y}^{4} \]
          3. sqr-powN/A

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

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

            \[\leadsto {x}^{\left(\frac{4}{2}\right)} \cdot {x}^{\left(\frac{4}{2}\right)} - \color{blue}{{y}^{\left(\frac{4}{2}\right)} \cdot {y}^{\left(\frac{4}{2}\right)}} \]
          6. difference-of-squaresN/A

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

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

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

            \[\leadsto \left({y}^{\color{blue}{2}} + {x}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
          10. unpow2N/A

            \[\leadsto \left(\color{blue}{y \cdot y} + {x}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
          11. lower-fma.f64N/A

            \[\leadsto \color{blue}{\mathsf{fma}\left(y, y, {x}^{\left(\frac{4}{2}\right)}\right)} \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
          12. metadata-evalN/A

            \[\leadsto \mathsf{fma}\left(y, y, {x}^{\color{blue}{2}}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
          13. unpow2N/A

            \[\leadsto \mathsf{fma}\left(y, y, \color{blue}{x \cdot x}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
          14. lower-*.f64N/A

            \[\leadsto \mathsf{fma}\left(y, y, \color{blue}{x \cdot x}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
          15. metadata-evalN/A

            \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left({x}^{\color{blue}{2}} - {y}^{\left(\frac{4}{2}\right)}\right) \]
          16. unpow2N/A

            \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(\color{blue}{x \cdot x} - {y}^{\left(\frac{4}{2}\right)}\right) \]
          17. metadata-evalN/A

            \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(x \cdot x - {y}^{\color{blue}{2}}\right) \]
          18. unpow2N/A

            \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(x \cdot x - \color{blue}{y \cdot y}\right) \]
          19. difference-of-squaresN/A

            \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
          20. lower-*.f64N/A

            \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
          21. lower-+.f64N/A

            \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(\color{blue}{\left(x + y\right)} \cdot \left(x - y\right)\right) \]
          22. lower--.f6499.9

            \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(\left(x + y\right) \cdot \color{blue}{\left(x - y\right)}\right) \]
        4. Applied rewrites99.9%

          \[\leadsto \color{blue}{\mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
        5. Applied rewrites99.9%

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

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

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

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

            \[\leadsto \left(\color{blue}{\left(\frac{{y}^{2}}{{x}^{2}} + 1\right)} \cdot {x}^{2}\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
          4. unpow2N/A

            \[\leadsto \left(\left(\frac{\color{blue}{y \cdot y}}{{x}^{2}} + 1\right) \cdot {x}^{2}\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
          5. unpow2N/A

            \[\leadsto \left(\left(\frac{y \cdot y}{\color{blue}{x \cdot x}} + 1\right) \cdot {x}^{2}\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
          6. times-fracN/A

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

            \[\leadsto \left(\color{blue}{\mathsf{fma}\left(\frac{y}{x}, \frac{y}{x}, 1\right)} \cdot {x}^{2}\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
          8. lower-/.f64N/A

            \[\leadsto \left(\mathsf{fma}\left(\color{blue}{\frac{y}{x}}, \frac{y}{x}, 1\right) \cdot {x}^{2}\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
          9. lower-/.f64N/A

            \[\leadsto \left(\mathsf{fma}\left(\frac{y}{x}, \color{blue}{\frac{y}{x}}, 1\right) \cdot {x}^{2}\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
          10. unpow2N/A

            \[\leadsto \left(\mathsf{fma}\left(\frac{y}{x}, \frac{y}{x}, 1\right) \cdot \color{blue}{\left(x \cdot x\right)}\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
          11. lower-*.f6499.9

            \[\leadsto \left(\mathsf{fma}\left(\frac{y}{x}, \frac{y}{x}, 1\right) \cdot \color{blue}{\left(x \cdot x\right)}\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
        8. Applied rewrites99.9%

          \[\leadsto \color{blue}{\left(\mathsf{fma}\left(\frac{y}{x}, \frac{y}{x}, 1\right) \cdot \left(x \cdot x\right)\right)} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
        9. Taylor expanded in x around inf

          \[\leadsto \left(1 \cdot \left(\color{blue}{x} \cdot x\right)\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
        10. Step-by-step derivation
          1. Applied rewrites99.5%

            \[\leadsto \left(1 \cdot \left(\color{blue}{x} \cdot x\right)\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
        11. Recombined 2 regimes into one program.
        12. Final simplification99.6%

          \[\leadsto \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -2 \cdot 10^{-311}:\\ \;\;\;\;y \cdot \left(y \cdot \left(\left(-y\right) \cdot y\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(1 \cdot \left(x \cdot x\right)\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)\\ \end{array} \]
        13. Add Preprocessing

        Alternative 3: 92.4% accurate, 0.9× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -2 \cdot 10^{-311}:\\ \;\;\;\;y \cdot \left(y \cdot \left(\left(-y\right) \cdot y\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(x \cdot x\right)\\ \end{array} \end{array} \]
        (FPCore (x y)
         :precision binary64
         (if (<= (- (pow x 4.0) (pow y 4.0)) -2e-311)
           (* y (* y (* (- y) y)))
           (* (fma y y (* x x)) (* x x))))
        double code(double x, double y) {
        	double tmp;
        	if ((pow(x, 4.0) - pow(y, 4.0)) <= -2e-311) {
        		tmp = y * (y * (-y * y));
        	} else {
        		tmp = fma(y, y, (x * x)) * (x * x);
        	}
        	return tmp;
        }
        
        function code(x, y)
        	tmp = 0.0
        	if (Float64((x ^ 4.0) - (y ^ 4.0)) <= -2e-311)
        		tmp = Float64(y * Float64(y * Float64(Float64(-y) * y)));
        	else
        		tmp = Float64(fma(y, y, Float64(x * x)) * Float64(x * x));
        	end
        	return tmp
        end
        
        code[x_, y_] := If[LessEqual[N[(N[Power[x, 4.0], $MachinePrecision] - N[Power[y, 4.0], $MachinePrecision]), $MachinePrecision], -2e-311], N[(y * N[(y * N[((-y) * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(y * y + N[(x * x), $MachinePrecision]), $MachinePrecision] * N[(x * x), $MachinePrecision]), $MachinePrecision]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;{x}^{4} - {y}^{4} \leq -2 \cdot 10^{-311}:\\
        \;\;\;\;y \cdot \left(y \cdot \left(\left(-y\right) \cdot y\right)\right)\\
        
        \mathbf{else}:\\
        \;\;\;\;\mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(x \cdot x\right)\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if (-.f64 (pow.f64 x #s(literal 4 binary64)) (pow.f64 y #s(literal 4 binary64))) < -1.9999999999999e-311

          1. Initial program 100.0%

            \[{x}^{4} - {y}^{4} \]
          2. Add Preprocessing
          3. Taylor expanded in x around 0

            \[\leadsto \color{blue}{-1 \cdot {y}^{4}} \]
          4. Step-by-step derivation
            1. mul-1-negN/A

              \[\leadsto \color{blue}{\mathsf{neg}\left({y}^{4}\right)} \]
            2. lower-neg.f64N/A

              \[\leadsto \color{blue}{-{y}^{4}} \]
            3. lower-pow.f64100.0

              \[\leadsto -\color{blue}{{y}^{4}} \]
          5. Applied rewrites100.0%

            \[\leadsto \color{blue}{-{y}^{4}} \]
          6. Step-by-step derivation
            1. Applied rewrites99.7%

              \[\leadsto \left(\left(-y\right) \cdot y\right) \cdot \color{blue}{\left(y \cdot y\right)} \]
            2. Step-by-step derivation
              1. Applied rewrites99.7%

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

              if -1.9999999999999e-311 < (-.f64 (pow.f64 x #s(literal 4 binary64)) (pow.f64 y #s(literal 4 binary64)))

              1. Initial program 76.9%

                \[{x}^{4} - {y}^{4} \]
              2. Add Preprocessing
              3. Step-by-step derivation
                1. lift--.f64N/A

                  \[\leadsto \color{blue}{{x}^{4} - {y}^{4}} \]
                2. lift-pow.f64N/A

                  \[\leadsto \color{blue}{{x}^{4}} - {y}^{4} \]
                3. sqr-powN/A

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

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

                  \[\leadsto {x}^{\left(\frac{4}{2}\right)} \cdot {x}^{\left(\frac{4}{2}\right)} - \color{blue}{{y}^{\left(\frac{4}{2}\right)} \cdot {y}^{\left(\frac{4}{2}\right)}} \]
                6. difference-of-squaresN/A

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

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

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

                  \[\leadsto \left({y}^{\color{blue}{2}} + {x}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
                10. unpow2N/A

                  \[\leadsto \left(\color{blue}{y \cdot y} + {x}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
                11. lower-fma.f64N/A

                  \[\leadsto \color{blue}{\mathsf{fma}\left(y, y, {x}^{\left(\frac{4}{2}\right)}\right)} \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
                12. metadata-evalN/A

                  \[\leadsto \mathsf{fma}\left(y, y, {x}^{\color{blue}{2}}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
                13. unpow2N/A

                  \[\leadsto \mathsf{fma}\left(y, y, \color{blue}{x \cdot x}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
                14. lower-*.f64N/A

                  \[\leadsto \mathsf{fma}\left(y, y, \color{blue}{x \cdot x}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
                15. metadata-evalN/A

                  \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left({x}^{\color{blue}{2}} - {y}^{\left(\frac{4}{2}\right)}\right) \]
                16. unpow2N/A

                  \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(\color{blue}{x \cdot x} - {y}^{\left(\frac{4}{2}\right)}\right) \]
                17. metadata-evalN/A

                  \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(x \cdot x - {y}^{\color{blue}{2}}\right) \]
                18. unpow2N/A

                  \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(x \cdot x - \color{blue}{y \cdot y}\right) \]
                19. difference-of-squaresN/A

                  \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
                20. lower-*.f64N/A

                  \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
                21. lower-+.f64N/A

                  \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(\color{blue}{\left(x + y\right)} \cdot \left(x - y\right)\right) \]
                22. lower--.f6499.9

                  \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(\left(x + y\right) \cdot \color{blue}{\left(x - y\right)}\right) \]
              4. Applied rewrites99.9%

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

                \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \color{blue}{\left({x}^{2} \cdot \left(1 + \left(-1 \cdot \frac{y}{x} + \frac{y}{x}\right)\right)\right)} \]
              6. Step-by-step derivation
                1. unpow2N/A

                  \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot \left(1 + \left(-1 \cdot \frac{y}{x} + \frac{y}{x}\right)\right)\right) \]
                2. associate-*l*N/A

                  \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \color{blue}{\left(x \cdot \left(x \cdot \left(1 + \left(-1 \cdot \frac{y}{x} + \frac{y}{x}\right)\right)\right)\right)} \]
                3. distribute-lft1-inN/A

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

                  \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(x \cdot \left(x \cdot \left(1 + \color{blue}{0} \cdot \frac{y}{x}\right)\right)\right) \]
                5. mul0-lftN/A

                  \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(x \cdot \left(x \cdot \left(1 + \color{blue}{0}\right)\right)\right) \]
                6. metadata-evalN/A

                  \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(x \cdot \left(x \cdot \color{blue}{1}\right)\right) \]
                7. *-rgt-identityN/A

                  \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(x \cdot \color{blue}{x}\right) \]
                8. lower-*.f6488.6

                  \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
              7. Applied rewrites88.6%

                \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
            3. Recombined 2 regimes into one program.
            4. Final simplification93.0%

              \[\leadsto \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -2 \cdot 10^{-311}:\\ \;\;\;\;y \cdot \left(y \cdot \left(\left(-y\right) \cdot y\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(x \cdot x\right)\\ \end{array} \]
            5. Add Preprocessing

            Alternative 4: 60.7% accurate, 6.9× speedup?

            \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.3 \cdot 10^{+170} \lor \neg \left(x \leq 1.85 \cdot 10^{+161}\right):\\ \;\;\;\;\left(y \cdot y\right) \cdot \left(y \cdot y\right)\\ \mathbf{else}:\\ \;\;\;\;y \cdot \left(y \cdot \left(\left(-y\right) \cdot y\right)\right)\\ \end{array} \end{array} \]
            (FPCore (x y)
             :precision binary64
             (if (or (<= x -1.3e+170) (not (<= x 1.85e+161)))
               (* (* y y) (* y y))
               (* y (* y (* (- y) y)))))
            double code(double x, double y) {
            	double tmp;
            	if ((x <= -1.3e+170) || !(x <= 1.85e+161)) {
            		tmp = (y * y) * (y * y);
            	} else {
            		tmp = y * (y * (-y * y));
            	}
            	return tmp;
            }
            
            module fmin_fmax_functions
                implicit none
                private
                public fmax
                public fmin
            
                interface fmax
                    module procedure fmax88
                    module procedure fmax44
                    module procedure fmax84
                    module procedure fmax48
                end interface
                interface fmin
                    module procedure fmin88
                    module procedure fmin44
                    module procedure fmin84
                    module procedure fmin48
                end interface
            contains
                real(8) function fmax88(x, y) result (res)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                end function
                real(4) function fmax44(x, y) result (res)
                    real(4), intent (in) :: x
                    real(4), intent (in) :: y
                    res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                end function
                real(8) function fmax84(x, y) result(res)
                    real(8), intent (in) :: x
                    real(4), intent (in) :: y
                    res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                end function
                real(8) function fmax48(x, y) result(res)
                    real(4), intent (in) :: x
                    real(8), intent (in) :: y
                    res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                end function
                real(8) function fmin88(x, y) result (res)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                end function
                real(4) function fmin44(x, y) result (res)
                    real(4), intent (in) :: x
                    real(4), intent (in) :: y
                    res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                end function
                real(8) function fmin84(x, y) result(res)
                    real(8), intent (in) :: x
                    real(4), intent (in) :: y
                    res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                end function
                real(8) function fmin48(x, y) result(res)
                    real(4), intent (in) :: x
                    real(8), intent (in) :: y
                    res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                end function
            end module
            
            real(8) function code(x, y)
            use fmin_fmax_functions
                real(8), intent (in) :: x
                real(8), intent (in) :: y
                real(8) :: tmp
                if ((x <= (-1.3d+170)) .or. (.not. (x <= 1.85d+161))) then
                    tmp = (y * y) * (y * y)
                else
                    tmp = y * (y * (-y * y))
                end if
                code = tmp
            end function
            
            public static double code(double x, double y) {
            	double tmp;
            	if ((x <= -1.3e+170) || !(x <= 1.85e+161)) {
            		tmp = (y * y) * (y * y);
            	} else {
            		tmp = y * (y * (-y * y));
            	}
            	return tmp;
            }
            
            def code(x, y):
            	tmp = 0
            	if (x <= -1.3e+170) or not (x <= 1.85e+161):
            		tmp = (y * y) * (y * y)
            	else:
            		tmp = y * (y * (-y * y))
            	return tmp
            
            function code(x, y)
            	tmp = 0.0
            	if ((x <= -1.3e+170) || !(x <= 1.85e+161))
            		tmp = Float64(Float64(y * y) * Float64(y * y));
            	else
            		tmp = Float64(y * Float64(y * Float64(Float64(-y) * y)));
            	end
            	return tmp
            end
            
            function tmp_2 = code(x, y)
            	tmp = 0.0;
            	if ((x <= -1.3e+170) || ~((x <= 1.85e+161)))
            		tmp = (y * y) * (y * y);
            	else
            		tmp = y * (y * (-y * y));
            	end
            	tmp_2 = tmp;
            end
            
            code[x_, y_] := If[Or[LessEqual[x, -1.3e+170], N[Not[LessEqual[x, 1.85e+161]], $MachinePrecision]], N[(N[(y * y), $MachinePrecision] * N[(y * y), $MachinePrecision]), $MachinePrecision], N[(y * N[(y * N[((-y) * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
            
            \begin{array}{l}
            
            \\
            \begin{array}{l}
            \mathbf{if}\;x \leq -1.3 \cdot 10^{+170} \lor \neg \left(x \leq 1.85 \cdot 10^{+161}\right):\\
            \;\;\;\;\left(y \cdot y\right) \cdot \left(y \cdot y\right)\\
            
            \mathbf{else}:\\
            \;\;\;\;y \cdot \left(y \cdot \left(\left(-y\right) \cdot y\right)\right)\\
            
            
            \end{array}
            \end{array}
            
            Derivation
            1. Split input into 2 regimes
            2. if x < -1.2999999999999999e170 or 1.8499999999999999e161 < x

              1. Initial program 52.0%

                \[{x}^{4} - {y}^{4} \]
              2. Add Preprocessing
              3. Taylor expanded in x around 0

                \[\leadsto \color{blue}{-1 \cdot {y}^{4}} \]
              4. Step-by-step derivation
                1. mul-1-negN/A

                  \[\leadsto \color{blue}{\mathsf{neg}\left({y}^{4}\right)} \]
                2. lower-neg.f64N/A

                  \[\leadsto \color{blue}{-{y}^{4}} \]
                3. lower-pow.f6410.6

                  \[\leadsto -\color{blue}{{y}^{4}} \]
              5. Applied rewrites10.6%

                \[\leadsto \color{blue}{-{y}^{4}} \]
              6. Step-by-step derivation
                1. Applied rewrites39.5%

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

                if -1.2999999999999999e170 < x < 1.8499999999999999e161

                1. Initial program 94.2%

                  \[{x}^{4} - {y}^{4} \]
                2. Add Preprocessing
                3. Taylor expanded in x around 0

                  \[\leadsto \color{blue}{-1 \cdot {y}^{4}} \]
                4. Step-by-step derivation
                  1. mul-1-negN/A

                    \[\leadsto \color{blue}{\mathsf{neg}\left({y}^{4}\right)} \]
                  2. lower-neg.f64N/A

                    \[\leadsto \color{blue}{-{y}^{4}} \]
                  3. lower-pow.f6475.1

                    \[\leadsto -\color{blue}{{y}^{4}} \]
                5. Applied rewrites75.1%

                  \[\leadsto \color{blue}{-{y}^{4}} \]
                6. Step-by-step derivation
                  1. Applied rewrites75.0%

                    \[\leadsto \left(\left(-y\right) \cdot y\right) \cdot \color{blue}{\left(y \cdot y\right)} \]
                  2. Step-by-step derivation
                    1. Applied rewrites75.0%

                      \[\leadsto \left(-y\right) \cdot \color{blue}{\left(\left(-y\right) \cdot \left(\left(-y\right) \cdot y\right)\right)} \]
                  3. Recombined 2 regimes into one program.
                  4. Final simplification68.0%

                    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.3 \cdot 10^{+170} \lor \neg \left(x \leq 1.85 \cdot 10^{+161}\right):\\ \;\;\;\;\left(y \cdot y\right) \cdot \left(y \cdot y\right)\\ \mathbf{else}:\\ \;\;\;\;y \cdot \left(y \cdot \left(\left(-y\right) \cdot y\right)\right)\\ \end{array} \]
                  5. Add Preprocessing

                  Alternative 5: 60.7% accurate, 6.9× speedup?

                  \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.3 \cdot 10^{+170} \lor \neg \left(x \leq 1.85 \cdot 10^{+161}\right):\\ \;\;\;\;\left(y \cdot y\right) \cdot \left(y \cdot y\right)\\ \mathbf{else}:\\ \;\;\;\;\left(y \cdot y\right) \cdot \left(\left(-y\right) \cdot y\right)\\ \end{array} \end{array} \]
                  (FPCore (x y)
                   :precision binary64
                   (if (or (<= x -1.3e+170) (not (<= x 1.85e+161)))
                     (* (* y y) (* y y))
                     (* (* y y) (* (- y) y))))
                  double code(double x, double y) {
                  	double tmp;
                  	if ((x <= -1.3e+170) || !(x <= 1.85e+161)) {
                  		tmp = (y * y) * (y * y);
                  	} else {
                  		tmp = (y * y) * (-y * y);
                  	}
                  	return tmp;
                  }
                  
                  module fmin_fmax_functions
                      implicit none
                      private
                      public fmax
                      public fmin
                  
                      interface fmax
                          module procedure fmax88
                          module procedure fmax44
                          module procedure fmax84
                          module procedure fmax48
                      end interface
                      interface fmin
                          module procedure fmin88
                          module procedure fmin44
                          module procedure fmin84
                          module procedure fmin48
                      end interface
                  contains
                      real(8) function fmax88(x, y) result (res)
                          real(8), intent (in) :: x
                          real(8), intent (in) :: y
                          res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                      end function
                      real(4) function fmax44(x, y) result (res)
                          real(4), intent (in) :: x
                          real(4), intent (in) :: y
                          res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                      end function
                      real(8) function fmax84(x, y) result(res)
                          real(8), intent (in) :: x
                          real(4), intent (in) :: y
                          res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                      end function
                      real(8) function fmax48(x, y) result(res)
                          real(4), intent (in) :: x
                          real(8), intent (in) :: y
                          res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                      end function
                      real(8) function fmin88(x, y) result (res)
                          real(8), intent (in) :: x
                          real(8), intent (in) :: y
                          res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                      end function
                      real(4) function fmin44(x, y) result (res)
                          real(4), intent (in) :: x
                          real(4), intent (in) :: y
                          res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                      end function
                      real(8) function fmin84(x, y) result(res)
                          real(8), intent (in) :: x
                          real(4), intent (in) :: y
                          res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                      end function
                      real(8) function fmin48(x, y) result(res)
                          real(4), intent (in) :: x
                          real(8), intent (in) :: y
                          res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                      end function
                  end module
                  
                  real(8) function code(x, y)
                  use fmin_fmax_functions
                      real(8), intent (in) :: x
                      real(8), intent (in) :: y
                      real(8) :: tmp
                      if ((x <= (-1.3d+170)) .or. (.not. (x <= 1.85d+161))) then
                          tmp = (y * y) * (y * y)
                      else
                          tmp = (y * y) * (-y * y)
                      end if
                      code = tmp
                  end function
                  
                  public static double code(double x, double y) {
                  	double tmp;
                  	if ((x <= -1.3e+170) || !(x <= 1.85e+161)) {
                  		tmp = (y * y) * (y * y);
                  	} else {
                  		tmp = (y * y) * (-y * y);
                  	}
                  	return tmp;
                  }
                  
                  def code(x, y):
                  	tmp = 0
                  	if (x <= -1.3e+170) or not (x <= 1.85e+161):
                  		tmp = (y * y) * (y * y)
                  	else:
                  		tmp = (y * y) * (-y * y)
                  	return tmp
                  
                  function code(x, y)
                  	tmp = 0.0
                  	if ((x <= -1.3e+170) || !(x <= 1.85e+161))
                  		tmp = Float64(Float64(y * y) * Float64(y * y));
                  	else
                  		tmp = Float64(Float64(y * y) * Float64(Float64(-y) * y));
                  	end
                  	return tmp
                  end
                  
                  function tmp_2 = code(x, y)
                  	tmp = 0.0;
                  	if ((x <= -1.3e+170) || ~((x <= 1.85e+161)))
                  		tmp = (y * y) * (y * y);
                  	else
                  		tmp = (y * y) * (-y * y);
                  	end
                  	tmp_2 = tmp;
                  end
                  
                  code[x_, y_] := If[Or[LessEqual[x, -1.3e+170], N[Not[LessEqual[x, 1.85e+161]], $MachinePrecision]], N[(N[(y * y), $MachinePrecision] * N[(y * y), $MachinePrecision]), $MachinePrecision], N[(N[(y * y), $MachinePrecision] * N[((-y) * y), $MachinePrecision]), $MachinePrecision]]
                  
                  \begin{array}{l}
                  
                  \\
                  \begin{array}{l}
                  \mathbf{if}\;x \leq -1.3 \cdot 10^{+170} \lor \neg \left(x \leq 1.85 \cdot 10^{+161}\right):\\
                  \;\;\;\;\left(y \cdot y\right) \cdot \left(y \cdot y\right)\\
                  
                  \mathbf{else}:\\
                  \;\;\;\;\left(y \cdot y\right) \cdot \left(\left(-y\right) \cdot y\right)\\
                  
                  
                  \end{array}
                  \end{array}
                  
                  Derivation
                  1. Split input into 2 regimes
                  2. if x < -1.2999999999999999e170 or 1.8499999999999999e161 < x

                    1. Initial program 52.0%

                      \[{x}^{4} - {y}^{4} \]
                    2. Add Preprocessing
                    3. Taylor expanded in x around 0

                      \[\leadsto \color{blue}{-1 \cdot {y}^{4}} \]
                    4. Step-by-step derivation
                      1. mul-1-negN/A

                        \[\leadsto \color{blue}{\mathsf{neg}\left({y}^{4}\right)} \]
                      2. lower-neg.f64N/A

                        \[\leadsto \color{blue}{-{y}^{4}} \]
                      3. lower-pow.f6410.6

                        \[\leadsto -\color{blue}{{y}^{4}} \]
                    5. Applied rewrites10.6%

                      \[\leadsto \color{blue}{-{y}^{4}} \]
                    6. Step-by-step derivation
                      1. Applied rewrites39.5%

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

                      if -1.2999999999999999e170 < x < 1.8499999999999999e161

                      1. Initial program 94.2%

                        \[{x}^{4} - {y}^{4} \]
                      2. Add Preprocessing
                      3. Taylor expanded in x around 0

                        \[\leadsto \color{blue}{-1 \cdot {y}^{4}} \]
                      4. Step-by-step derivation
                        1. mul-1-negN/A

                          \[\leadsto \color{blue}{\mathsf{neg}\left({y}^{4}\right)} \]
                        2. lower-neg.f64N/A

                          \[\leadsto \color{blue}{-{y}^{4}} \]
                        3. lower-pow.f6475.1

                          \[\leadsto -\color{blue}{{y}^{4}} \]
                      5. Applied rewrites75.1%

                        \[\leadsto \color{blue}{-{y}^{4}} \]
                      6. Step-by-step derivation
                        1. Applied rewrites75.0%

                          \[\leadsto \left(\left(-y\right) \cdot y\right) \cdot \color{blue}{\left(y \cdot y\right)} \]
                      7. Recombined 2 regimes into one program.
                      8. Final simplification68.0%

                        \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.3 \cdot 10^{+170} \lor \neg \left(x \leq 1.85 \cdot 10^{+161}\right):\\ \;\;\;\;\left(y \cdot y\right) \cdot \left(y \cdot y\right)\\ \mathbf{else}:\\ \;\;\;\;\left(y \cdot y\right) \cdot \left(\left(-y\right) \cdot y\right)\\ \end{array} \]
                      9. Add Preprocessing

                      Alternative 6: 22.4% accurate, 12.9× speedup?

                      \[\begin{array}{l} \\ \left(y \cdot y\right) \cdot \left(y \cdot y\right) \end{array} \]
                      (FPCore (x y) :precision binary64 (* (* y y) (* y y)))
                      double code(double x, double y) {
                      	return (y * y) * (y * y);
                      }
                      
                      module fmin_fmax_functions
                          implicit none
                          private
                          public fmax
                          public fmin
                      
                          interface fmax
                              module procedure fmax88
                              module procedure fmax44
                              module procedure fmax84
                              module procedure fmax48
                          end interface
                          interface fmin
                              module procedure fmin88
                              module procedure fmin44
                              module procedure fmin84
                              module procedure fmin48
                          end interface
                      contains
                          real(8) function fmax88(x, y) result (res)
                              real(8), intent (in) :: x
                              real(8), intent (in) :: y
                              res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                          end function
                          real(4) function fmax44(x, y) result (res)
                              real(4), intent (in) :: x
                              real(4), intent (in) :: y
                              res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                          end function
                          real(8) function fmax84(x, y) result(res)
                              real(8), intent (in) :: x
                              real(4), intent (in) :: y
                              res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                          end function
                          real(8) function fmax48(x, y) result(res)
                              real(4), intent (in) :: x
                              real(8), intent (in) :: y
                              res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                          end function
                          real(8) function fmin88(x, y) result (res)
                              real(8), intent (in) :: x
                              real(8), intent (in) :: y
                              res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                          end function
                          real(4) function fmin44(x, y) result (res)
                              real(4), intent (in) :: x
                              real(4), intent (in) :: y
                              res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                          end function
                          real(8) function fmin84(x, y) result(res)
                              real(8), intent (in) :: x
                              real(4), intent (in) :: y
                              res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                          end function
                          real(8) function fmin48(x, y) result(res)
                              real(4), intent (in) :: x
                              real(8), intent (in) :: y
                              res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                          end function
                      end module
                      
                      real(8) function code(x, y)
                      use fmin_fmax_functions
                          real(8), intent (in) :: x
                          real(8), intent (in) :: y
                          code = (y * y) * (y * y)
                      end function
                      
                      public static double code(double x, double y) {
                      	return (y * y) * (y * y);
                      }
                      
                      def code(x, y):
                      	return (y * y) * (y * y)
                      
                      function code(x, y)
                      	return Float64(Float64(y * y) * Float64(y * y))
                      end
                      
                      function tmp = code(x, y)
                      	tmp = (y * y) * (y * y);
                      end
                      
                      code[x_, y_] := N[(N[(y * y), $MachinePrecision] * N[(y * y), $MachinePrecision]), $MachinePrecision]
                      
                      \begin{array}{l}
                      
                      \\
                      \left(y \cdot y\right) \cdot \left(y \cdot y\right)
                      \end{array}
                      
                      Derivation
                      1. Initial program 85.9%

                        \[{x}^{4} - {y}^{4} \]
                      2. Add Preprocessing
                      3. Taylor expanded in x around 0

                        \[\leadsto \color{blue}{-1 \cdot {y}^{4}} \]
                      4. Step-by-step derivation
                        1. mul-1-negN/A

                          \[\leadsto \color{blue}{\mathsf{neg}\left({y}^{4}\right)} \]
                        2. lower-neg.f64N/A

                          \[\leadsto \color{blue}{-{y}^{4}} \]
                        3. lower-pow.f6462.5

                          \[\leadsto -\color{blue}{{y}^{4}} \]
                      5. Applied rewrites62.5%

                        \[\leadsto \color{blue}{-{y}^{4}} \]
                      6. Step-by-step derivation
                        1. Applied rewrites25.0%

                          \[\leadsto \left(y \cdot y\right) \cdot \color{blue}{\left(y \cdot y\right)} \]
                        2. Add Preprocessing

                        Reproduce

                        ?
                        herbie shell --seed 2024350 
                        (FPCore (x y)
                          :name "Radioactive exchange between two surfaces"
                          :precision binary64
                          (- (pow x 4.0) (pow y 4.0)))