Radioactive exchange between two surfaces

Percentage Accurate: 86.0% → 99.8%
Time: 7.5s
Alternatives: 9
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);
}
real(8) function code(x, y)
    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 9 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: 86.0% 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);
}
real(8) function code(x, y)
    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, 4.0× speedup?

\[\begin{array}{l} \\ \frac{y - x}{\frac{\frac{-1}{x + y}}{\mathsf{fma}\left(y, y, x \cdot x\right)}} \end{array} \]
(FPCore (x y)
 :precision binary64
 (/ (- y x) (/ (/ -1.0 (+ x y)) (fma y y (* x x)))))
double code(double x, double y) {
	return (y - x) / ((-1.0 / (x + y)) / fma(y, y, (x * x)));
}
function code(x, y)
	return Float64(Float64(y - x) / Float64(Float64(-1.0 / Float64(x + y)) / fma(y, y, Float64(x * x))))
end
code[x_, y_] := N[(N[(y - x), $MachinePrecision] / N[(N[(-1.0 / N[(x + y), $MachinePrecision]), $MachinePrecision] / N[(y * y + N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{y - x}{\frac{\frac{-1}{x + y}}{\mathsf{fma}\left(y, y, x \cdot x\right)}}
\end{array}
Derivation
  1. Initial program 86.3%

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

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

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

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

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

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

      \[\leadsto \left(\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)\right) \cdot \color{blue}{\left(x + y\right)} \]
    7. flip3-+N/A

      \[\leadsto \left(\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)\right) \cdot \color{blue}{\frac{{x}^{3} + {y}^{3}}{x \cdot x + \left(y \cdot y - x \cdot y\right)}} \]
    8. clear-numN/A

      \[\leadsto \left(\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)\right) \cdot \color{blue}{\frac{1}{\frac{x \cdot x + \left(y \cdot y - x \cdot y\right)}{{x}^{3} + {y}^{3}}}} \]
    9. clear-numN/A

      \[\leadsto \left(\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)\right) \cdot \frac{1}{\color{blue}{\frac{1}{\frac{{x}^{3} + {y}^{3}}{x \cdot x + \left(y \cdot y - x \cdot y\right)}}}} \]
    10. flip3-+N/A

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

      \[\leadsto \left(\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)\right) \cdot \frac{1}{\frac{1}{\color{blue}{x + y}}} \]
    12. un-div-invN/A

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

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

      \[\leadsto \frac{\color{blue}{\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)}}{\frac{1}{x + y}} \]
    15. lower-/.f6499.8

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

    \[\leadsto \color{blue}{\frac{\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)}{\frac{1}{x + y}}} \]
  7. Step-by-step derivation
    1. lift-/.f64N/A

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

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

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

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

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

      \[\leadsto \left(x - y\right) \cdot \frac{1}{\color{blue}{\frac{1}{\left(x + y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)}}} \]
    7. lift-*.f64N/A

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

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

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

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

      \[\leadsto \color{blue}{\frac{\mathsf{neg}\left(\left(x - y\right)\right)}{\mathsf{neg}\left(\frac{1}{\left(x + y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)}\right)}} \]
    12. lift--.f64N/A

      \[\leadsto \frac{\mathsf{neg}\left(\color{blue}{\left(x - y\right)}\right)}{\mathsf{neg}\left(\frac{1}{\left(x + y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)}\right)} \]
    13. sub-negN/A

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

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

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

      \[\leadsto \frac{\color{blue}{y} + \left(\mathsf{neg}\left(x\right)\right)}{\mathsf{neg}\left(\frac{1}{\left(x + y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)}\right)} \]
    17. sub-negN/A

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

      \[\leadsto \frac{\color{blue}{y - x}}{\mathsf{neg}\left(\frac{1}{\left(x + y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)}\right)} \]
    19. lift-/.f64N/A

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

    \[\leadsto \color{blue}{\frac{y - x}{\frac{-1}{\left(y + x\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)}}} \]
  9. Step-by-step derivation
    1. lift-/.f64N/A

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{y - x}{\color{blue}{\frac{\mathsf{neg}\left(\frac{1}{x + y}\right)}{\mathsf{fma}\left(y, y, x \cdot x\right)}}} \]
    11. neg-mul-1N/A

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

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

      \[\leadsto \frac{y - x}{\frac{\color{blue}{\frac{-1}{x + y}}}{\mathsf{fma}\left(y, y, x \cdot x\right)}} \]
    14. lower-/.f6499.8

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

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

Alternative 2: 92.7% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -2 \cdot 10^{-280}:\\ \;\;\;\;\left(\left(\left(-y\right) \cdot y\right) \cdot y\right) \cdot y\\ \mathbf{else}:\\ \;\;\;\;\left(\left(x \cdot x\right) \cdot x\right) \cdot x\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= (- (pow x 4.0) (pow y 4.0)) -2e-280)
   (* (* (* (- y) y) y) y)
   (* (* (* x x) x) x)))
double code(double x, double y) {
	double tmp;
	if ((pow(x, 4.0) - pow(y, 4.0)) <= -2e-280) {
		tmp = ((-y * y) * y) * y;
	} else {
		tmp = ((x * x) * x) * x;
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: tmp
    if (((x ** 4.0d0) - (y ** 4.0d0)) <= (-2d-280)) then
        tmp = ((-y * y) * y) * y
    else
        tmp = ((x * x) * x) * x
    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-280) {
		tmp = ((-y * y) * y) * y;
	} else {
		tmp = ((x * x) * x) * x;
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if (math.pow(x, 4.0) - math.pow(y, 4.0)) <= -2e-280:
		tmp = ((-y * y) * y) * y
	else:
		tmp = ((x * x) * x) * x
	return tmp
function code(x, y)
	tmp = 0.0
	if (Float64((x ^ 4.0) - (y ^ 4.0)) <= -2e-280)
		tmp = Float64(Float64(Float64(Float64(-y) * y) * y) * y);
	else
		tmp = Float64(Float64(Float64(x * x) * x) * x);
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if (((x ^ 4.0) - (y ^ 4.0)) <= -2e-280)
		tmp = ((-y * y) * y) * y;
	else
		tmp = ((x * x) * x) * x;
	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-280], N[(N[(N[((-y) * y), $MachinePrecision] * y), $MachinePrecision] * y), $MachinePrecision], N[(N[(N[(x * x), $MachinePrecision] * x), $MachinePrecision] * x), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;{x}^{4} - {y}^{4} \leq -2 \cdot 10^{-280}:\\
\;\;\;\;\left(\left(\left(-y\right) \cdot y\right) \cdot y\right) \cdot y\\

\mathbf{else}:\\
\;\;\;\;\left(\left(x \cdot x\right) \cdot x\right) \cdot x\\


\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))) < -1.9999999999999999e-280

    1. Initial program 100.0%

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

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

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

        \[\leadsto \color{blue}{\mathsf{neg}\left({y}^{4}\right)} \]
      3. lower-pow.f6499.5

        \[\leadsto -\color{blue}{{y}^{4}} \]
    5. Applied rewrites99.5%

      \[\leadsto \color{blue}{-{y}^{4}} \]
    6. Step-by-step derivation
      1. Applied rewrites99.3%

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

      if -1.9999999999999999e-280 < (-.f64 (pow.f64 x #s(literal 4 binary64)) (pow.f64 y #s(literal 4 binary64)))

      1. Initial program 78.7%

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

        \[\leadsto \color{blue}{{x}^{4}} \]
      4. Step-by-step derivation
        1. lower-pow.f6491.5

          \[\leadsto \color{blue}{{x}^{4}} \]
      5. Applied rewrites91.5%

        \[\leadsto \color{blue}{{x}^{4}} \]
      6. Step-by-step derivation
        1. Applied rewrites91.4%

          \[\leadsto \left(\left(x \cdot x\right) \cdot x\right) \cdot \color{blue}{x} \]
      7. Recombined 2 regimes into one program.
      8. Add Preprocessing

      Alternative 3: 92.7% accurate, 0.9× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -2 \cdot 10^{-280}:\\ \;\;\;\;\left(\left(-y\right) \cdot y\right) \cdot \left(y \cdot y\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(x \cdot x\right) \cdot x\right) \cdot x\\ \end{array} \end{array} \]
      (FPCore (x y)
       :precision binary64
       (if (<= (- (pow x 4.0) (pow y 4.0)) -2e-280)
         (* (* (- y) y) (* y y))
         (* (* (* x x) x) x)))
      double code(double x, double y) {
      	double tmp;
      	if ((pow(x, 4.0) - pow(y, 4.0)) <= -2e-280) {
      		tmp = (-y * y) * (y * y);
      	} else {
      		tmp = ((x * x) * x) * x;
      	}
      	return tmp;
      }
      
      real(8) function code(x, y)
          real(8), intent (in) :: x
          real(8), intent (in) :: y
          real(8) :: tmp
          if (((x ** 4.0d0) - (y ** 4.0d0)) <= (-2d-280)) then
              tmp = (-y * y) * (y * y)
          else
              tmp = ((x * x) * x) * x
          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-280) {
      		tmp = (-y * y) * (y * y);
      	} else {
      		tmp = ((x * x) * x) * x;
      	}
      	return tmp;
      }
      
      def code(x, y):
      	tmp = 0
      	if (math.pow(x, 4.0) - math.pow(y, 4.0)) <= -2e-280:
      		tmp = (-y * y) * (y * y)
      	else:
      		tmp = ((x * x) * x) * x
      	return tmp
      
      function code(x, y)
      	tmp = 0.0
      	if (Float64((x ^ 4.0) - (y ^ 4.0)) <= -2e-280)
      		tmp = Float64(Float64(Float64(-y) * y) * Float64(y * y));
      	else
      		tmp = Float64(Float64(Float64(x * x) * x) * x);
      	end
      	return tmp
      end
      
      function tmp_2 = code(x, y)
      	tmp = 0.0;
      	if (((x ^ 4.0) - (y ^ 4.0)) <= -2e-280)
      		tmp = (-y * y) * (y * y);
      	else
      		tmp = ((x * x) * x) * x;
      	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-280], N[(N[((-y) * y), $MachinePrecision] * N[(y * y), $MachinePrecision]), $MachinePrecision], N[(N[(N[(x * x), $MachinePrecision] * x), $MachinePrecision] * x), $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;{x}^{4} - {y}^{4} \leq -2 \cdot 10^{-280}:\\
      \;\;\;\;\left(\left(-y\right) \cdot y\right) \cdot \left(y \cdot y\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\left(\left(x \cdot x\right) \cdot x\right) \cdot x\\
      
      
      \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))) < -1.9999999999999999e-280

        1. Initial program 100.0%

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

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

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

            \[\leadsto \color{blue}{\mathsf{neg}\left({y}^{4}\right)} \]
          3. lower-pow.f6499.5

            \[\leadsto -\color{blue}{{y}^{4}} \]
        5. Applied rewrites99.5%

          \[\leadsto \color{blue}{-{y}^{4}} \]
        6. Step-by-step derivation
          1. Applied rewrites99.2%

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

          if -1.9999999999999999e-280 < (-.f64 (pow.f64 x #s(literal 4 binary64)) (pow.f64 y #s(literal 4 binary64)))

          1. Initial program 78.7%

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

            \[\leadsto \color{blue}{{x}^{4}} \]
          4. Step-by-step derivation
            1. lower-pow.f6491.5

              \[\leadsto \color{blue}{{x}^{4}} \]
          5. Applied rewrites91.5%

            \[\leadsto \color{blue}{{x}^{4}} \]
          6. Step-by-step derivation
            1. Applied rewrites91.4%

              \[\leadsto \left(\left(x \cdot x\right) \cdot x\right) \cdot \color{blue}{x} \]
          7. Recombined 2 regimes into one program.
          8. Add Preprocessing

          Alternative 4: 99.8% accurate, 4.6× speedup?

          \[\begin{array}{l} \\ \frac{y - x}{\frac{-1}{\mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(x + y\right)}} \end{array} \]
          (FPCore (x y)
           :precision binary64
           (/ (- y x) (/ -1.0 (* (fma y y (* x x)) (+ x y)))))
          double code(double x, double y) {
          	return (y - x) / (-1.0 / (fma(y, y, (x * x)) * (x + y)));
          }
          
          function code(x, y)
          	return Float64(Float64(y - x) / Float64(-1.0 / Float64(fma(y, y, Float64(x * x)) * Float64(x + y))))
          end
          
          code[x_, y_] := N[(N[(y - x), $MachinePrecision] / N[(-1.0 / N[(N[(y * y + N[(x * x), $MachinePrecision]), $MachinePrecision] * N[(x + y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \frac{y - x}{\frac{-1}{\mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(x + y\right)}}
          \end{array}
          
          Derivation
          1. Initial program 86.3%

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

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

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

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

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

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

              \[\leadsto \left(\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)\right) \cdot \color{blue}{\left(x + y\right)} \]
            7. flip3-+N/A

              \[\leadsto \left(\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)\right) \cdot \color{blue}{\frac{{x}^{3} + {y}^{3}}{x \cdot x + \left(y \cdot y - x \cdot y\right)}} \]
            8. clear-numN/A

              \[\leadsto \left(\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)\right) \cdot \color{blue}{\frac{1}{\frac{x \cdot x + \left(y \cdot y - x \cdot y\right)}{{x}^{3} + {y}^{3}}}} \]
            9. clear-numN/A

              \[\leadsto \left(\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)\right) \cdot \frac{1}{\color{blue}{\frac{1}{\frac{{x}^{3} + {y}^{3}}{x \cdot x + \left(y \cdot y - x \cdot y\right)}}}} \]
            10. flip3-+N/A

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

              \[\leadsto \left(\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)\right) \cdot \frac{1}{\frac{1}{\color{blue}{x + y}}} \]
            12. un-div-invN/A

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

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

              \[\leadsto \frac{\color{blue}{\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)}}{\frac{1}{x + y}} \]
            15. lower-/.f6499.8

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

            \[\leadsto \color{blue}{\frac{\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)}{\frac{1}{x + y}}} \]
          7. Step-by-step derivation
            1. lift-/.f64N/A

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

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

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

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

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

              \[\leadsto \left(x - y\right) \cdot \frac{1}{\color{blue}{\frac{1}{\left(x + y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)}}} \]
            7. lift-*.f64N/A

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

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

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

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

              \[\leadsto \color{blue}{\frac{\mathsf{neg}\left(\left(x - y\right)\right)}{\mathsf{neg}\left(\frac{1}{\left(x + y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)}\right)}} \]
            12. lift--.f64N/A

              \[\leadsto \frac{\mathsf{neg}\left(\color{blue}{\left(x - y\right)}\right)}{\mathsf{neg}\left(\frac{1}{\left(x + y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)}\right)} \]
            13. sub-negN/A

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

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

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

              \[\leadsto \frac{\color{blue}{y} + \left(\mathsf{neg}\left(x\right)\right)}{\mathsf{neg}\left(\frac{1}{\left(x + y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)}\right)} \]
            17. sub-negN/A

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

              \[\leadsto \frac{\color{blue}{y - x}}{\mathsf{neg}\left(\frac{1}{\left(x + y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)}\right)} \]
            19. lift-/.f64N/A

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

            \[\leadsto \color{blue}{\frac{y - x}{\frac{-1}{\left(y + x\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)}}} \]
          9. Final simplification99.8%

            \[\leadsto \frac{y - x}{\frac{-1}{\mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(x + y\right)}} \]
          10. Add Preprocessing

          Alternative 5: 99.8% accurate, 4.6× speedup?

          \[\begin{array}{l} \\ \frac{\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)}{\frac{1}{x + y}} \end{array} \]
          (FPCore (x y)
           :precision binary64
           (/ (* (- x y) (fma y y (* x x))) (/ 1.0 (+ x y))))
          double code(double x, double y) {
          	return ((x - y) * fma(y, y, (x * x))) / (1.0 / (x + y));
          }
          
          function code(x, y)
          	return Float64(Float64(Float64(x - y) * fma(y, y, Float64(x * x))) / Float64(1.0 / Float64(x + y)))
          end
          
          code[x_, y_] := N[(N[(N[(x - y), $MachinePrecision] * N[(y * y + N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(1.0 / N[(x + y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \frac{\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)}{\frac{1}{x + y}}
          \end{array}
          
          Derivation
          1. Initial program 86.3%

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

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

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

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

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

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

              \[\leadsto \left(\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)\right) \cdot \color{blue}{\left(x + y\right)} \]
            7. flip3-+N/A

              \[\leadsto \left(\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)\right) \cdot \color{blue}{\frac{{x}^{3} + {y}^{3}}{x \cdot x + \left(y \cdot y - x \cdot y\right)}} \]
            8. clear-numN/A

              \[\leadsto \left(\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)\right) \cdot \color{blue}{\frac{1}{\frac{x \cdot x + \left(y \cdot y - x \cdot y\right)}{{x}^{3} + {y}^{3}}}} \]
            9. clear-numN/A

              \[\leadsto \left(\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)\right) \cdot \frac{1}{\color{blue}{\frac{1}{\frac{{x}^{3} + {y}^{3}}{x \cdot x + \left(y \cdot y - x \cdot y\right)}}}} \]
            10. flip3-+N/A

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

              \[\leadsto \left(\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)\right) \cdot \frac{1}{\frac{1}{\color{blue}{x + y}}} \]
            12. un-div-invN/A

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

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

              \[\leadsto \frac{\color{blue}{\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)}}{\frac{1}{x + y}} \]
            15. lower-/.f6499.8

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

            \[\leadsto \color{blue}{\frac{\left(x - y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)}{\frac{1}{x + y}}} \]
          7. Add Preprocessing

          Alternative 6: 99.8% accurate, 4.6× speedup?

          \[\begin{array}{l} \\ \frac{x - y}{\frac{1}{x + y}} \cdot \mathsf{fma}\left(y, y, x \cdot x\right) \end{array} \]
          (FPCore (x y)
           :precision binary64
           (* (/ (- x y) (/ 1.0 (+ x y))) (fma y y (* x x))))
          double code(double x, double y) {
          	return ((x - y) / (1.0 / (x + y))) * fma(y, y, (x * x));
          }
          
          function code(x, y)
          	return Float64(Float64(Float64(x - y) / Float64(1.0 / Float64(x + y))) * fma(y, y, Float64(x * x)))
          end
          
          code[x_, y_] := N[(N[(N[(x - y), $MachinePrecision] / N[(1.0 / N[(x + y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(y * y + N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \frac{x - y}{\frac{1}{x + y}} \cdot \mathsf{fma}\left(y, y, x \cdot x\right)
          \end{array}
          
          Derivation
          1. Initial program 86.3%

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

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

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

              \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(\left(x - y\right) \cdot \color{blue}{\left(x + y\right)}\right) \]
            4. flip3-+N/A

              \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(\left(x - y\right) \cdot \color{blue}{\frac{{x}^{3} + {y}^{3}}{x \cdot x + \left(y \cdot y - x \cdot y\right)}}\right) \]
            5. clear-numN/A

              \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(\left(x - y\right) \cdot \color{blue}{\frac{1}{\frac{x \cdot x + \left(y \cdot y - x \cdot y\right)}{{x}^{3} + {y}^{3}}}}\right) \]
            6. clear-numN/A

              \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(\left(x - y\right) \cdot \frac{1}{\color{blue}{\frac{1}{\frac{{x}^{3} + {y}^{3}}{x \cdot x + \left(y \cdot y - x \cdot y\right)}}}}\right) \]
            7. flip3-+N/A

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

              \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(\left(x - y\right) \cdot \frac{1}{\frac{1}{\color{blue}{x + y}}}\right) \]
            9. un-div-invN/A

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

              \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \color{blue}{\frac{x - y}{\frac{1}{x + y}}} \]
            11. lower-/.f6499.8

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

            \[\leadsto \mathsf{fma}\left(y, y, x \cdot x\right) \cdot \color{blue}{\frac{x - y}{\frac{1}{x + y}}} \]
          7. Final simplification99.8%

            \[\leadsto \frac{x - y}{\frac{1}{x + y}} \cdot \mathsf{fma}\left(y, y, x \cdot x\right) \]
          8. Add Preprocessing

          Alternative 7: 99.8% accurate, 7.4× speedup?

          \[\begin{array}{l} \\ \left(\left(x - y\right) \cdot \left(x + y\right)\right) \cdot \mathsf{fma}\left(x, x, y \cdot y\right) \end{array} \]
          (FPCore (x y) :precision binary64 (* (* (- x y) (+ x y)) (fma x x (* y y))))
          double code(double x, double y) {
          	return ((x - y) * (x + y)) * fma(x, x, (y * y));
          }
          
          function code(x, y)
          	return Float64(Float64(Float64(x - y) * Float64(x + y)) * fma(x, x, Float64(y * y)))
          end
          
          code[x_, y_] := N[(N[(N[(x - y), $MachinePrecision] * N[(x + y), $MachinePrecision]), $MachinePrecision] * N[(x * x + N[(y * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \left(\left(x - y\right) \cdot \left(x + y\right)\right) \cdot \mathsf{fma}\left(x, x, y \cdot y\right)
          \end{array}
          
          Derivation
          1. Initial program 86.3%

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

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

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

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

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

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

            \[\leadsto \color{blue}{\mathsf{fma}\left(x, x, y \cdot y\right)} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
          7. Final simplification99.8%

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

          Alternative 8: 56.7% accurate, 12.9× speedup?

          \[\begin{array}{l} \\ \left(\left(x \cdot x\right) \cdot x\right) \cdot x \end{array} \]
          (FPCore (x y) :precision binary64 (* (* (* x x) x) x))
          double code(double x, double y) {
          	return ((x * x) * x) * x;
          }
          
          real(8) function code(x, y)
              real(8), intent (in) :: x
              real(8), intent (in) :: y
              code = ((x * x) * x) * x
          end function
          
          public static double code(double x, double y) {
          	return ((x * x) * x) * x;
          }
          
          def code(x, y):
          	return ((x * x) * x) * x
          
          function code(x, y)
          	return Float64(Float64(Float64(x * x) * x) * x)
          end
          
          function tmp = code(x, y)
          	tmp = ((x * x) * x) * x;
          end
          
          code[x_, y_] := N[(N[(N[(x * x), $MachinePrecision] * x), $MachinePrecision] * x), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \left(\left(x \cdot x\right) \cdot x\right) \cdot x
          \end{array}
          
          Derivation
          1. Initial program 86.3%

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

            \[\leadsto \color{blue}{{x}^{4}} \]
          4. Step-by-step derivation
            1. lower-pow.f6459.3

              \[\leadsto \color{blue}{{x}^{4}} \]
          5. Applied rewrites59.3%

            \[\leadsto \color{blue}{{x}^{4}} \]
          6. Step-by-step derivation
            1. Applied rewrites59.2%

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

            Alternative 9: 56.7% accurate, 12.9× speedup?

            \[\begin{array}{l} \\ \left(x \cdot x\right) \cdot \left(x \cdot x\right) \end{array} \]
            (FPCore (x y) :precision binary64 (* (* x x) (* x x)))
            double code(double x, double y) {
            	return (x * x) * (x * x);
            }
            
            real(8) function code(x, y)
                real(8), intent (in) :: x
                real(8), intent (in) :: y
                code = (x * x) * (x * x)
            end function
            
            public static double code(double x, double y) {
            	return (x * x) * (x * x);
            }
            
            def code(x, y):
            	return (x * x) * (x * x)
            
            function code(x, y)
            	return Float64(Float64(x * x) * Float64(x * x))
            end
            
            function tmp = code(x, y)
            	tmp = (x * x) * (x * x);
            end
            
            code[x_, y_] := N[(N[(x * x), $MachinePrecision] * N[(x * x), $MachinePrecision]), $MachinePrecision]
            
            \begin{array}{l}
            
            \\
            \left(x \cdot x\right) \cdot \left(x \cdot x\right)
            \end{array}
            
            Derivation
            1. Initial program 86.3%

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

              \[\leadsto \color{blue}{{x}^{4}} \]
            4. Step-by-step derivation
              1. lower-pow.f6459.3

                \[\leadsto \color{blue}{{x}^{4}} \]
            5. Applied rewrites59.3%

              \[\leadsto \color{blue}{{x}^{4}} \]
            6. Step-by-step derivation
              1. Applied rewrites59.1%

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

              Reproduce

              ?
              herbie shell --seed 2024235 
              (FPCore (x y)
                :name "Radioactive exchange between two surfaces"
                :precision binary64
                (- (pow x 4.0) (pow y 4.0)))