Bouland and Aaronson, Equation (26)

Percentage Accurate: 99.9% → 100.0%
Time: 8.4s
Alternatives: 7
Speedup: 2.2×

Specification

?
\[\begin{array}{l} \\ \left({\left(a \cdot a + b \cdot b\right)}^{2} + 4 \cdot \left(b \cdot b\right)\right) - 1 \end{array} \]
(FPCore (a b)
 :precision binary64
 (- (+ (pow (+ (* a a) (* b b)) 2.0) (* 4.0 (* b b))) 1.0))
double code(double a, double b) {
	return (pow(((a * a) + (b * b)), 2.0) + (4.0 * (b * b))) - 1.0;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = ((((a * a) + (b * b)) ** 2.0d0) + (4.0d0 * (b * b))) - 1.0d0
end function
public static double code(double a, double b) {
	return (Math.pow(((a * a) + (b * b)), 2.0) + (4.0 * (b * b))) - 1.0;
}
def code(a, b):
	return (math.pow(((a * a) + (b * b)), 2.0) + (4.0 * (b * b))) - 1.0
function code(a, b)
	return Float64(Float64((Float64(Float64(a * a) + Float64(b * b)) ^ 2.0) + Float64(4.0 * Float64(b * b))) - 1.0)
end
function tmp = code(a, b)
	tmp = ((((a * a) + (b * b)) ^ 2.0) + (4.0 * (b * b))) - 1.0;
end
code[a_, b_] := N[(N[(N[Power[N[(N[(a * a), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision] + N[(4.0 * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - 1.0), $MachinePrecision]
\begin{array}{l}

\\
\left({\left(a \cdot a + b \cdot b\right)}^{2} + 4 \cdot \left(b \cdot b\right)\right) - 1
\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 7 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: 99.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left({\left(a \cdot a + b \cdot b\right)}^{2} + 4 \cdot \left(b \cdot b\right)\right) - 1 \end{array} \]
(FPCore (a b)
 :precision binary64
 (- (+ (pow (+ (* a a) (* b b)) 2.0) (* 4.0 (* b b))) 1.0))
double code(double a, double b) {
	return (pow(((a * a) + (b * b)), 2.0) + (4.0 * (b * b))) - 1.0;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = ((((a * a) + (b * b)) ** 2.0d0) + (4.0d0 * (b * b))) - 1.0d0
end function
public static double code(double a, double b) {
	return (Math.pow(((a * a) + (b * b)), 2.0) + (4.0 * (b * b))) - 1.0;
}
def code(a, b):
	return (math.pow(((a * a) + (b * b)), 2.0) + (4.0 * (b * b))) - 1.0
function code(a, b)
	return Float64(Float64((Float64(Float64(a * a) + Float64(b * b)) ^ 2.0) + Float64(4.0 * Float64(b * b))) - 1.0)
end
function tmp = code(a, b)
	tmp = ((((a * a) + (b * b)) ^ 2.0) + (4.0 * (b * b))) - 1.0;
end
code[a_, b_] := N[(N[(N[Power[N[(N[(a * a), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision] + N[(4.0 * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - 1.0), $MachinePrecision]
\begin{array}{l}

\\
\left({\left(a \cdot a + b \cdot b\right)}^{2} + 4 \cdot \left(b \cdot b\right)\right) - 1
\end{array}

Alternative 1: 100.0% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \left(4 \cdot \left(b \cdot b\right) + \mathsf{fma}\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a, a, {b}^{4}\right)\right) - 1 \end{array} \]
(FPCore (a b)
 :precision binary64
 (-
  (+ (* 4.0 (* b b)) (fma (* (fma (* b b) 2.0 (* a a)) a) a (pow b 4.0)))
  1.0))
double code(double a, double b) {
	return ((4.0 * (b * b)) + fma((fma((b * b), 2.0, (a * a)) * a), a, pow(b, 4.0))) - 1.0;
}
function code(a, b)
	return Float64(Float64(Float64(4.0 * Float64(b * b)) + fma(Float64(fma(Float64(b * b), 2.0, Float64(a * a)) * a), a, (b ^ 4.0))) - 1.0)
end
code[a_, b_] := N[(N[(N[(4.0 * N[(b * b), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(N[(b * b), $MachinePrecision] * 2.0 + N[(a * a), $MachinePrecision]), $MachinePrecision] * a), $MachinePrecision] * a + N[Power[b, 4.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - 1.0), $MachinePrecision]
\begin{array}{l}

\\
\left(4 \cdot \left(b \cdot b\right) + \mathsf{fma}\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a, a, {b}^{4}\right)\right) - 1
\end{array}
Derivation
  1. Initial program 99.9%

    \[\left({\left(a \cdot a + b \cdot b\right)}^{2} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
  2. Add Preprocessing
  3. Taylor expanded in a around 0

    \[\leadsto \left(\color{blue}{\left({a}^{2} \cdot \left(2 \cdot {b}^{2} + {a}^{2}\right) + {b}^{4}\right)} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
  4. Step-by-step derivation
    1. *-commutativeN/A

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

      \[\leadsto \left(\left(\left(2 \cdot {b}^{2} + {a}^{2}\right) \cdot \color{blue}{\left(a \cdot a\right)} + {b}^{4}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    3. associate-*r*N/A

      \[\leadsto \left(\left(\color{blue}{\left(\left(2 \cdot {b}^{2} + {a}^{2}\right) \cdot a\right) \cdot a} + {b}^{4}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    4. lower-fma.f64N/A

      \[\leadsto \left(\color{blue}{\mathsf{fma}\left(\left(2 \cdot {b}^{2} + {a}^{2}\right) \cdot a, a, {b}^{4}\right)} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    5. lower-*.f64N/A

      \[\leadsto \left(\mathsf{fma}\left(\color{blue}{\left(2 \cdot {b}^{2} + {a}^{2}\right) \cdot a}, a, {b}^{4}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    6. *-commutativeN/A

      \[\leadsto \left(\mathsf{fma}\left(\left(\color{blue}{{b}^{2} \cdot 2} + {a}^{2}\right) \cdot a, a, {b}^{4}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    7. lower-fma.f64N/A

      \[\leadsto \left(\mathsf{fma}\left(\color{blue}{\mathsf{fma}\left({b}^{2}, 2, {a}^{2}\right)} \cdot a, a, {b}^{4}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    8. unpow2N/A

      \[\leadsto \left(\mathsf{fma}\left(\mathsf{fma}\left(\color{blue}{b \cdot b}, 2, {a}^{2}\right) \cdot a, a, {b}^{4}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    9. lower-*.f64N/A

      \[\leadsto \left(\mathsf{fma}\left(\mathsf{fma}\left(\color{blue}{b \cdot b}, 2, {a}^{2}\right) \cdot a, a, {b}^{4}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    10. unpow2N/A

      \[\leadsto \left(\mathsf{fma}\left(\mathsf{fma}\left(b \cdot b, 2, \color{blue}{a \cdot a}\right) \cdot a, a, {b}^{4}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    11. lower-*.f64N/A

      \[\leadsto \left(\mathsf{fma}\left(\mathsf{fma}\left(b \cdot b, 2, \color{blue}{a \cdot a}\right) \cdot a, a, {b}^{4}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    12. lower-pow.f6499.9

      \[\leadsto \left(\mathsf{fma}\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a, a, \color{blue}{{b}^{4}}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
  5. Applied rewrites99.9%

    \[\leadsto \left(\color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a, a, {b}^{4}\right)} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
  6. Final simplification99.9%

    \[\leadsto \left(4 \cdot \left(b \cdot b\right) + \mathsf{fma}\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a, a, {b}^{4}\right)\right) - 1 \]
  7. Add Preprocessing

Alternative 2: 99.9% accurate, 2.2× speedup?

\[\begin{array}{l} \\ \left(\mathsf{fma}\left(b \cdot b, b \cdot b, \left(\mathsf{fma}\left(2, b \cdot b, a \cdot a\right) \cdot a\right) \cdot a\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \end{array} \]
(FPCore (a b)
 :precision binary64
 (-
  (+
   (fma (* b b) (* b b) (* (* (fma 2.0 (* b b) (* a a)) a) a))
   (* 4.0 (* b b)))
  1.0))
double code(double a, double b) {
	return (fma((b * b), (b * b), ((fma(2.0, (b * b), (a * a)) * a) * a)) + (4.0 * (b * b))) - 1.0;
}
function code(a, b)
	return Float64(Float64(fma(Float64(b * b), Float64(b * b), Float64(Float64(fma(2.0, Float64(b * b), Float64(a * a)) * a) * a)) + Float64(4.0 * Float64(b * b))) - 1.0)
end
code[a_, b_] := N[(N[(N[(N[(b * b), $MachinePrecision] * N[(b * b), $MachinePrecision] + N[(N[(N[(2.0 * N[(b * b), $MachinePrecision] + N[(a * a), $MachinePrecision]), $MachinePrecision] * a), $MachinePrecision] * a), $MachinePrecision]), $MachinePrecision] + N[(4.0 * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - 1.0), $MachinePrecision]
\begin{array}{l}

\\
\left(\mathsf{fma}\left(b \cdot b, b \cdot b, \left(\mathsf{fma}\left(2, b \cdot b, a \cdot a\right) \cdot a\right) \cdot a\right) + 4 \cdot \left(b \cdot b\right)\right) - 1
\end{array}
Derivation
  1. Initial program 99.9%

    \[\left({\left(a \cdot a + b \cdot b\right)}^{2} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
  2. Add Preprocessing
  3. Taylor expanded in a around 0

    \[\leadsto \left(\color{blue}{\left({a}^{2} \cdot \left(2 \cdot {b}^{2} + {a}^{2}\right) + {b}^{4}\right)} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
  4. Step-by-step derivation
    1. *-commutativeN/A

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

      \[\leadsto \left(\left(\left(2 \cdot {b}^{2} + {a}^{2}\right) \cdot \color{blue}{\left(a \cdot a\right)} + {b}^{4}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    3. associate-*r*N/A

      \[\leadsto \left(\left(\color{blue}{\left(\left(2 \cdot {b}^{2} + {a}^{2}\right) \cdot a\right) \cdot a} + {b}^{4}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    4. lower-fma.f64N/A

      \[\leadsto \left(\color{blue}{\mathsf{fma}\left(\left(2 \cdot {b}^{2} + {a}^{2}\right) \cdot a, a, {b}^{4}\right)} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    5. lower-*.f64N/A

      \[\leadsto \left(\mathsf{fma}\left(\color{blue}{\left(2 \cdot {b}^{2} + {a}^{2}\right) \cdot a}, a, {b}^{4}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    6. *-commutativeN/A

      \[\leadsto \left(\mathsf{fma}\left(\left(\color{blue}{{b}^{2} \cdot 2} + {a}^{2}\right) \cdot a, a, {b}^{4}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    7. lower-fma.f64N/A

      \[\leadsto \left(\mathsf{fma}\left(\color{blue}{\mathsf{fma}\left({b}^{2}, 2, {a}^{2}\right)} \cdot a, a, {b}^{4}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    8. unpow2N/A

      \[\leadsto \left(\mathsf{fma}\left(\mathsf{fma}\left(\color{blue}{b \cdot b}, 2, {a}^{2}\right) \cdot a, a, {b}^{4}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    9. lower-*.f64N/A

      \[\leadsto \left(\mathsf{fma}\left(\mathsf{fma}\left(\color{blue}{b \cdot b}, 2, {a}^{2}\right) \cdot a, a, {b}^{4}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    10. unpow2N/A

      \[\leadsto \left(\mathsf{fma}\left(\mathsf{fma}\left(b \cdot b, 2, \color{blue}{a \cdot a}\right) \cdot a, a, {b}^{4}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    11. lower-*.f64N/A

      \[\leadsto \left(\mathsf{fma}\left(\mathsf{fma}\left(b \cdot b, 2, \color{blue}{a \cdot a}\right) \cdot a, a, {b}^{4}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    12. lower-pow.f6499.9

      \[\leadsto \left(\mathsf{fma}\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a, a, \color{blue}{{b}^{4}}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
  5. Applied rewrites99.9%

    \[\leadsto \left(\color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a, a, {b}^{4}\right)} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
  6. Step-by-step derivation
    1. Applied rewrites99.9%

      \[\leadsto \left(\mathsf{fma}\left(b \cdot b, \color{blue}{b \cdot b}, \left(\mathsf{fma}\left(2, b \cdot b, a \cdot a\right) \cdot a\right) \cdot a\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    2. Add Preprocessing

    Alternative 3: 98.1% accurate, 2.5× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \cdot a \leq 5 \cdot 10^{-23}:\\ \;\;\;\;\left(\mathsf{fma}\left(b, b, 4\right) \cdot b\right) \cdot b - 1\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(b \cdot b, 4, \left(\mathsf{fma}\left(2, b \cdot b, a \cdot a\right) \cdot a\right) \cdot a - 1\right)\\ \end{array} \end{array} \]
    (FPCore (a b)
     :precision binary64
     (if (<= (* a a) 5e-23)
       (- (* (* (fma b b 4.0) b) b) 1.0)
       (fma (* b b) 4.0 (- (* (* (fma 2.0 (* b b) (* a a)) a) a) 1.0))))
    double code(double a, double b) {
    	double tmp;
    	if ((a * a) <= 5e-23) {
    		tmp = ((fma(b, b, 4.0) * b) * b) - 1.0;
    	} else {
    		tmp = fma((b * b), 4.0, (((fma(2.0, (b * b), (a * a)) * a) * a) - 1.0));
    	}
    	return tmp;
    }
    
    function code(a, b)
    	tmp = 0.0
    	if (Float64(a * a) <= 5e-23)
    		tmp = Float64(Float64(Float64(fma(b, b, 4.0) * b) * b) - 1.0);
    	else
    		tmp = fma(Float64(b * b), 4.0, Float64(Float64(Float64(fma(2.0, Float64(b * b), Float64(a * a)) * a) * a) - 1.0));
    	end
    	return tmp
    end
    
    code[a_, b_] := If[LessEqual[N[(a * a), $MachinePrecision], 5e-23], N[(N[(N[(N[(b * b + 4.0), $MachinePrecision] * b), $MachinePrecision] * b), $MachinePrecision] - 1.0), $MachinePrecision], N[(N[(b * b), $MachinePrecision] * 4.0 + N[(N[(N[(N[(2.0 * N[(b * b), $MachinePrecision] + N[(a * a), $MachinePrecision]), $MachinePrecision] * a), $MachinePrecision] * a), $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;a \cdot a \leq 5 \cdot 10^{-23}:\\
    \;\;\;\;\left(\mathsf{fma}\left(b, b, 4\right) \cdot b\right) \cdot b - 1\\
    
    \mathbf{else}:\\
    \;\;\;\;\mathsf{fma}\left(b \cdot b, 4, \left(\mathsf{fma}\left(2, b \cdot b, a \cdot a\right) \cdot a\right) \cdot a - 1\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (*.f64 a a) < 5.0000000000000002e-23

      1. Initial program 99.9%

        \[\left({\left(a \cdot a + b \cdot b\right)}^{2} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
      2. Add Preprocessing
      3. Taylor expanded in a around 0

        \[\leadsto \color{blue}{\left(2 \cdot \left({a}^{2} \cdot {b}^{2}\right) + \left(4 \cdot {b}^{2} + {b}^{4}\right)\right)} - 1 \]
      4. Step-by-step derivation
        1. associate-+r+N/A

          \[\leadsto \color{blue}{\left(\left(2 \cdot \left({a}^{2} \cdot {b}^{2}\right) + 4 \cdot {b}^{2}\right) + {b}^{4}\right)} - 1 \]
        2. associate-*r*N/A

          \[\leadsto \left(\left(\color{blue}{\left(2 \cdot {a}^{2}\right) \cdot {b}^{2}} + 4 \cdot {b}^{2}\right) + {b}^{4}\right) - 1 \]
        3. distribute-rgt-inN/A

          \[\leadsto \left(\color{blue}{{b}^{2} \cdot \left(2 \cdot {a}^{2} + 4\right)} + {b}^{4}\right) - 1 \]
        4. +-commutativeN/A

          \[\leadsto \left({b}^{2} \cdot \color{blue}{\left(4 + 2 \cdot {a}^{2}\right)} + {b}^{4}\right) - 1 \]
        5. metadata-evalN/A

          \[\leadsto \left({b}^{2} \cdot \left(4 + 2 \cdot {a}^{2}\right) + {b}^{\color{blue}{\left(2 \cdot 2\right)}}\right) - 1 \]
        6. pow-sqrN/A

          \[\leadsto \left({b}^{2} \cdot \left(4 + 2 \cdot {a}^{2}\right) + \color{blue}{{b}^{2} \cdot {b}^{2}}\right) - 1 \]
        7. distribute-lft-inN/A

          \[\leadsto \color{blue}{{b}^{2} \cdot \left(\left(4 + 2 \cdot {a}^{2}\right) + {b}^{2}\right)} - 1 \]
        8. associate-+r+N/A

          \[\leadsto {b}^{2} \cdot \color{blue}{\left(4 + \left(2 \cdot {a}^{2} + {b}^{2}\right)\right)} - 1 \]
        9. *-commutativeN/A

          \[\leadsto \color{blue}{\left(4 + \left(2 \cdot {a}^{2} + {b}^{2}\right)\right) \cdot {b}^{2}} - 1 \]
        10. unpow2N/A

          \[\leadsto \left(4 + \left(2 \cdot {a}^{2} + {b}^{2}\right)\right) \cdot \color{blue}{\left(b \cdot b\right)} - 1 \]
        11. associate-*r*N/A

          \[\leadsto \color{blue}{\left(\left(4 + \left(2 \cdot {a}^{2} + {b}^{2}\right)\right) \cdot b\right) \cdot b} - 1 \]
        12. lower-*.f64N/A

          \[\leadsto \color{blue}{\left(\left(4 + \left(2 \cdot {a}^{2} + {b}^{2}\right)\right) \cdot b\right) \cdot b} - 1 \]
      5. Applied rewrites99.9%

        \[\leadsto \color{blue}{\left(\mathsf{fma}\left(b, b, \mathsf{fma}\left(a \cdot a, 2, 4\right)\right) \cdot b\right) \cdot b} - 1 \]
      6. Taylor expanded in a around 0

        \[\leadsto \left(b \cdot \left(4 + {b}^{2}\right)\right) \cdot b - 1 \]
      7. Step-by-step derivation
        1. Applied rewrites99.9%

          \[\leadsto \left(\mathsf{fma}\left(b, b, 4\right) \cdot b\right) \cdot b - 1 \]

        if 5.0000000000000002e-23 < (*.f64 a a)

        1. Initial program 99.8%

          \[\left({\left(a \cdot a + b \cdot b\right)}^{2} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
        2. Add Preprocessing
        3. Taylor expanded in b around 0

          \[\leadsto \left(\color{blue}{\left(2 \cdot \left({a}^{2} \cdot {b}^{2}\right) + {a}^{4}\right)} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
        4. Step-by-step derivation
          1. metadata-evalN/A

            \[\leadsto \left(\left(2 \cdot \left({a}^{2} \cdot {b}^{2}\right) + {a}^{\color{blue}{\left(2 \cdot 2\right)}}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
          2. pow-sqrN/A

            \[\leadsto \left(\left(2 \cdot \left({a}^{2} \cdot {b}^{2}\right) + \color{blue}{{a}^{2} \cdot {a}^{2}}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
          3. count-2-revN/A

            \[\leadsto \left(\left(\color{blue}{\left({a}^{2} \cdot {b}^{2} + {a}^{2} \cdot {b}^{2}\right)} + {a}^{2} \cdot {a}^{2}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
          4. distribute-lft-inN/A

            \[\leadsto \left(\left(\color{blue}{{a}^{2} \cdot \left({b}^{2} + {b}^{2}\right)} + {a}^{2} \cdot {a}^{2}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
          5. count-2-revN/A

            \[\leadsto \left(\left({a}^{2} \cdot \color{blue}{\left(2 \cdot {b}^{2}\right)} + {a}^{2} \cdot {a}^{2}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
          6. distribute-lft-inN/A

            \[\leadsto \left(\color{blue}{{a}^{2} \cdot \left(2 \cdot {b}^{2} + {a}^{2}\right)} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
          7. *-commutativeN/A

            \[\leadsto \left(\color{blue}{\left(2 \cdot {b}^{2} + {a}^{2}\right) \cdot {a}^{2}} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
          8. unpow2N/A

            \[\leadsto \left(\left(2 \cdot {b}^{2} + {a}^{2}\right) \cdot \color{blue}{\left(a \cdot a\right)} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
          9. associate-*r*N/A

            \[\leadsto \left(\color{blue}{\left(\left(2 \cdot {b}^{2} + {a}^{2}\right) \cdot a\right) \cdot a} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
          10. lower-*.f64N/A

            \[\leadsto \left(\color{blue}{\left(\left(2 \cdot {b}^{2} + {a}^{2}\right) \cdot a\right) \cdot a} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
          11. lower-*.f64N/A

            \[\leadsto \left(\color{blue}{\left(\left(2 \cdot {b}^{2} + {a}^{2}\right) \cdot a\right)} \cdot a + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
          12. *-commutativeN/A

            \[\leadsto \left(\left(\left(\color{blue}{{b}^{2} \cdot 2} + {a}^{2}\right) \cdot a\right) \cdot a + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
          13. lower-fma.f64N/A

            \[\leadsto \left(\left(\color{blue}{\mathsf{fma}\left({b}^{2}, 2, {a}^{2}\right)} \cdot a\right) \cdot a + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
          14. unpow2N/A

            \[\leadsto \left(\left(\mathsf{fma}\left(\color{blue}{b \cdot b}, 2, {a}^{2}\right) \cdot a\right) \cdot a + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
          15. lower-*.f64N/A

            \[\leadsto \left(\left(\mathsf{fma}\left(\color{blue}{b \cdot b}, 2, {a}^{2}\right) \cdot a\right) \cdot a + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
          16. unpow2N/A

            \[\leadsto \left(\left(\mathsf{fma}\left(b \cdot b, 2, \color{blue}{a \cdot a}\right) \cdot a\right) \cdot a + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
          17. lower-*.f6497.1

            \[\leadsto \left(\left(\mathsf{fma}\left(b \cdot b, 2, \color{blue}{a \cdot a}\right) \cdot a\right) \cdot a + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
        5. Applied rewrites97.1%

          \[\leadsto \left(\color{blue}{\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
        6. Step-by-step derivation
          1. lift--.f64N/A

            \[\leadsto \color{blue}{\left(\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a + 4 \cdot \left(b \cdot b\right)\right) - 1} \]
          2. lift-+.f64N/A

            \[\leadsto \color{blue}{\left(\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a + 4 \cdot \left(b \cdot b\right)\right)} - 1 \]
          3. +-commutativeN/A

            \[\leadsto \color{blue}{\left(4 \cdot \left(b \cdot b\right) + \left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a\right)} - 1 \]
          4. associate--l+N/A

            \[\leadsto \color{blue}{4 \cdot \left(b \cdot b\right) + \left(\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a - 1\right)} \]
          5. lift-*.f64N/A

            \[\leadsto \color{blue}{4 \cdot \left(b \cdot b\right)} + \left(\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a - 1\right) \]
          6. *-commutativeN/A

            \[\leadsto \color{blue}{\left(b \cdot b\right) \cdot 4} + \left(\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a - 1\right) \]
          7. lower-fma.f64N/A

            \[\leadsto \color{blue}{\mathsf{fma}\left(b \cdot b, 4, \left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a - 1\right)} \]
          8. lower--.f6497.1

            \[\leadsto \mathsf{fma}\left(b \cdot b, 4, \color{blue}{\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a - 1}\right) \]
        7. Applied rewrites97.1%

          \[\leadsto \color{blue}{\mathsf{fma}\left(b \cdot b, 4, \left(\mathsf{fma}\left(2, b \cdot b, a \cdot a\right) \cdot a\right) \cdot a - 1\right)} \]
      8. Recombined 2 regimes into one program.
      9. Add Preprocessing

      Alternative 4: 97.5% accurate, 3.2× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \cdot a \leq 5 \cdot 10^{-23}:\\ \;\;\;\;\left(\mathsf{fma}\left(b, b, 4\right) \cdot b\right) \cdot b - 1\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(b \cdot b, 4, \left(\left(a \cdot a\right) \cdot a\right) \cdot a - 1\right)\\ \end{array} \end{array} \]
      (FPCore (a b)
       :precision binary64
       (if (<= (* a a) 5e-23)
         (- (* (* (fma b b 4.0) b) b) 1.0)
         (fma (* b b) 4.0 (- (* (* (* a a) a) a) 1.0))))
      double code(double a, double b) {
      	double tmp;
      	if ((a * a) <= 5e-23) {
      		tmp = ((fma(b, b, 4.0) * b) * b) - 1.0;
      	} else {
      		tmp = fma((b * b), 4.0, ((((a * a) * a) * a) - 1.0));
      	}
      	return tmp;
      }
      
      function code(a, b)
      	tmp = 0.0
      	if (Float64(a * a) <= 5e-23)
      		tmp = Float64(Float64(Float64(fma(b, b, 4.0) * b) * b) - 1.0);
      	else
      		tmp = fma(Float64(b * b), 4.0, Float64(Float64(Float64(Float64(a * a) * a) * a) - 1.0));
      	end
      	return tmp
      end
      
      code[a_, b_] := If[LessEqual[N[(a * a), $MachinePrecision], 5e-23], N[(N[(N[(N[(b * b + 4.0), $MachinePrecision] * b), $MachinePrecision] * b), $MachinePrecision] - 1.0), $MachinePrecision], N[(N[(b * b), $MachinePrecision] * 4.0 + N[(N[(N[(N[(a * a), $MachinePrecision] * a), $MachinePrecision] * a), $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;a \cdot a \leq 5 \cdot 10^{-23}:\\
      \;\;\;\;\left(\mathsf{fma}\left(b, b, 4\right) \cdot b\right) \cdot b - 1\\
      
      \mathbf{else}:\\
      \;\;\;\;\mathsf{fma}\left(b \cdot b, 4, \left(\left(a \cdot a\right) \cdot a\right) \cdot a - 1\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (*.f64 a a) < 5.0000000000000002e-23

        1. Initial program 99.9%

          \[\left({\left(a \cdot a + b \cdot b\right)}^{2} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
        2. Add Preprocessing
        3. Taylor expanded in a around 0

          \[\leadsto \color{blue}{\left(2 \cdot \left({a}^{2} \cdot {b}^{2}\right) + \left(4 \cdot {b}^{2} + {b}^{4}\right)\right)} - 1 \]
        4. Step-by-step derivation
          1. associate-+r+N/A

            \[\leadsto \color{blue}{\left(\left(2 \cdot \left({a}^{2} \cdot {b}^{2}\right) + 4 \cdot {b}^{2}\right) + {b}^{4}\right)} - 1 \]
          2. associate-*r*N/A

            \[\leadsto \left(\left(\color{blue}{\left(2 \cdot {a}^{2}\right) \cdot {b}^{2}} + 4 \cdot {b}^{2}\right) + {b}^{4}\right) - 1 \]
          3. distribute-rgt-inN/A

            \[\leadsto \left(\color{blue}{{b}^{2} \cdot \left(2 \cdot {a}^{2} + 4\right)} + {b}^{4}\right) - 1 \]
          4. +-commutativeN/A

            \[\leadsto \left({b}^{2} \cdot \color{blue}{\left(4 + 2 \cdot {a}^{2}\right)} + {b}^{4}\right) - 1 \]
          5. metadata-evalN/A

            \[\leadsto \left({b}^{2} \cdot \left(4 + 2 \cdot {a}^{2}\right) + {b}^{\color{blue}{\left(2 \cdot 2\right)}}\right) - 1 \]
          6. pow-sqrN/A

            \[\leadsto \left({b}^{2} \cdot \left(4 + 2 \cdot {a}^{2}\right) + \color{blue}{{b}^{2} \cdot {b}^{2}}\right) - 1 \]
          7. distribute-lft-inN/A

            \[\leadsto \color{blue}{{b}^{2} \cdot \left(\left(4 + 2 \cdot {a}^{2}\right) + {b}^{2}\right)} - 1 \]
          8. associate-+r+N/A

            \[\leadsto {b}^{2} \cdot \color{blue}{\left(4 + \left(2 \cdot {a}^{2} + {b}^{2}\right)\right)} - 1 \]
          9. *-commutativeN/A

            \[\leadsto \color{blue}{\left(4 + \left(2 \cdot {a}^{2} + {b}^{2}\right)\right) \cdot {b}^{2}} - 1 \]
          10. unpow2N/A

            \[\leadsto \left(4 + \left(2 \cdot {a}^{2} + {b}^{2}\right)\right) \cdot \color{blue}{\left(b \cdot b\right)} - 1 \]
          11. associate-*r*N/A

            \[\leadsto \color{blue}{\left(\left(4 + \left(2 \cdot {a}^{2} + {b}^{2}\right)\right) \cdot b\right) \cdot b} - 1 \]
          12. lower-*.f64N/A

            \[\leadsto \color{blue}{\left(\left(4 + \left(2 \cdot {a}^{2} + {b}^{2}\right)\right) \cdot b\right) \cdot b} - 1 \]
        5. Applied rewrites99.9%

          \[\leadsto \color{blue}{\left(\mathsf{fma}\left(b, b, \mathsf{fma}\left(a \cdot a, 2, 4\right)\right) \cdot b\right) \cdot b} - 1 \]
        6. Taylor expanded in a around 0

          \[\leadsto \left(b \cdot \left(4 + {b}^{2}\right)\right) \cdot b - 1 \]
        7. Step-by-step derivation
          1. Applied rewrites99.9%

            \[\leadsto \left(\mathsf{fma}\left(b, b, 4\right) \cdot b\right) \cdot b - 1 \]

          if 5.0000000000000002e-23 < (*.f64 a a)

          1. Initial program 99.8%

            \[\left({\left(a \cdot a + b \cdot b\right)}^{2} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
          2. Add Preprocessing
          3. Taylor expanded in b around 0

            \[\leadsto \left(\color{blue}{\left(2 \cdot \left({a}^{2} \cdot {b}^{2}\right) + {a}^{4}\right)} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
          4. Step-by-step derivation
            1. metadata-evalN/A

              \[\leadsto \left(\left(2 \cdot \left({a}^{2} \cdot {b}^{2}\right) + {a}^{\color{blue}{\left(2 \cdot 2\right)}}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
            2. pow-sqrN/A

              \[\leadsto \left(\left(2 \cdot \left({a}^{2} \cdot {b}^{2}\right) + \color{blue}{{a}^{2} \cdot {a}^{2}}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
            3. count-2-revN/A

              \[\leadsto \left(\left(\color{blue}{\left({a}^{2} \cdot {b}^{2} + {a}^{2} \cdot {b}^{2}\right)} + {a}^{2} \cdot {a}^{2}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
            4. distribute-lft-inN/A

              \[\leadsto \left(\left(\color{blue}{{a}^{2} \cdot \left({b}^{2} + {b}^{2}\right)} + {a}^{2} \cdot {a}^{2}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
            5. count-2-revN/A

              \[\leadsto \left(\left({a}^{2} \cdot \color{blue}{\left(2 \cdot {b}^{2}\right)} + {a}^{2} \cdot {a}^{2}\right) + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
            6. distribute-lft-inN/A

              \[\leadsto \left(\color{blue}{{a}^{2} \cdot \left(2 \cdot {b}^{2} + {a}^{2}\right)} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
            7. *-commutativeN/A

              \[\leadsto \left(\color{blue}{\left(2 \cdot {b}^{2} + {a}^{2}\right) \cdot {a}^{2}} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
            8. unpow2N/A

              \[\leadsto \left(\left(2 \cdot {b}^{2} + {a}^{2}\right) \cdot \color{blue}{\left(a \cdot a\right)} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
            9. associate-*r*N/A

              \[\leadsto \left(\color{blue}{\left(\left(2 \cdot {b}^{2} + {a}^{2}\right) \cdot a\right) \cdot a} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
            10. lower-*.f64N/A

              \[\leadsto \left(\color{blue}{\left(\left(2 \cdot {b}^{2} + {a}^{2}\right) \cdot a\right) \cdot a} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
            11. lower-*.f64N/A

              \[\leadsto \left(\color{blue}{\left(\left(2 \cdot {b}^{2} + {a}^{2}\right) \cdot a\right)} \cdot a + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
            12. *-commutativeN/A

              \[\leadsto \left(\left(\left(\color{blue}{{b}^{2} \cdot 2} + {a}^{2}\right) \cdot a\right) \cdot a + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
            13. lower-fma.f64N/A

              \[\leadsto \left(\left(\color{blue}{\mathsf{fma}\left({b}^{2}, 2, {a}^{2}\right)} \cdot a\right) \cdot a + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
            14. unpow2N/A

              \[\leadsto \left(\left(\mathsf{fma}\left(\color{blue}{b \cdot b}, 2, {a}^{2}\right) \cdot a\right) \cdot a + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
            15. lower-*.f64N/A

              \[\leadsto \left(\left(\mathsf{fma}\left(\color{blue}{b \cdot b}, 2, {a}^{2}\right) \cdot a\right) \cdot a + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
            16. unpow2N/A

              \[\leadsto \left(\left(\mathsf{fma}\left(b \cdot b, 2, \color{blue}{a \cdot a}\right) \cdot a\right) \cdot a + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
            17. lower-*.f6497.1

              \[\leadsto \left(\left(\mathsf{fma}\left(b \cdot b, 2, \color{blue}{a \cdot a}\right) \cdot a\right) \cdot a + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
          5. Applied rewrites97.1%

            \[\leadsto \left(\color{blue}{\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
          6. Step-by-step derivation
            1. lift--.f64N/A

              \[\leadsto \color{blue}{\left(\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a + 4 \cdot \left(b \cdot b\right)\right) - 1} \]
            2. lift-+.f64N/A

              \[\leadsto \color{blue}{\left(\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a + 4 \cdot \left(b \cdot b\right)\right)} - 1 \]
            3. +-commutativeN/A

              \[\leadsto \color{blue}{\left(4 \cdot \left(b \cdot b\right) + \left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a\right)} - 1 \]
            4. associate--l+N/A

              \[\leadsto \color{blue}{4 \cdot \left(b \cdot b\right) + \left(\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a - 1\right)} \]
            5. lift-*.f64N/A

              \[\leadsto \color{blue}{4 \cdot \left(b \cdot b\right)} + \left(\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a - 1\right) \]
            6. *-commutativeN/A

              \[\leadsto \color{blue}{\left(b \cdot b\right) \cdot 4} + \left(\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a - 1\right) \]
            7. lower-fma.f64N/A

              \[\leadsto \color{blue}{\mathsf{fma}\left(b \cdot b, 4, \left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a - 1\right)} \]
            8. lower--.f6497.1

              \[\leadsto \mathsf{fma}\left(b \cdot b, 4, \color{blue}{\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a - 1}\right) \]
          7. Applied rewrites97.1%

            \[\leadsto \color{blue}{\mathsf{fma}\left(b \cdot b, 4, \left(\mathsf{fma}\left(2, b \cdot b, a \cdot a\right) \cdot a\right) \cdot a - 1\right)} \]
          8. Taylor expanded in a around inf

            \[\leadsto \mathsf{fma}\left(b \cdot b, 4, \left({a}^{2} \cdot a\right) \cdot a - 1\right) \]
          9. Step-by-step derivation
            1. Applied rewrites96.2%

              \[\leadsto \mathsf{fma}\left(b \cdot b, 4, \left(\left(a \cdot a\right) \cdot a\right) \cdot a - 1\right) \]
          10. Recombined 2 regimes into one program.
          11. Add Preprocessing

          Alternative 5: 94.0% accurate, 4.2× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \cdot a \leq 1.1 \cdot 10^{+81}:\\ \;\;\;\;\left(\mathsf{fma}\left(b, b, 4\right) \cdot b\right) \cdot b - 1\\ \mathbf{else}:\\ \;\;\;\;\left(a \cdot a\right) \cdot \left(a \cdot a\right) - 1\\ \end{array} \end{array} \]
          (FPCore (a b)
           :precision binary64
           (if (<= (* a a) 1.1e+81)
             (- (* (* (fma b b 4.0) b) b) 1.0)
             (- (* (* a a) (* a a)) 1.0)))
          double code(double a, double b) {
          	double tmp;
          	if ((a * a) <= 1.1e+81) {
          		tmp = ((fma(b, b, 4.0) * b) * b) - 1.0;
          	} else {
          		tmp = ((a * a) * (a * a)) - 1.0;
          	}
          	return tmp;
          }
          
          function code(a, b)
          	tmp = 0.0
          	if (Float64(a * a) <= 1.1e+81)
          		tmp = Float64(Float64(Float64(fma(b, b, 4.0) * b) * b) - 1.0);
          	else
          		tmp = Float64(Float64(Float64(a * a) * Float64(a * a)) - 1.0);
          	end
          	return tmp
          end
          
          code[a_, b_] := If[LessEqual[N[(a * a), $MachinePrecision], 1.1e+81], N[(N[(N[(N[(b * b + 4.0), $MachinePrecision] * b), $MachinePrecision] * b), $MachinePrecision] - 1.0), $MachinePrecision], N[(N[(N[(a * a), $MachinePrecision] * N[(a * a), $MachinePrecision]), $MachinePrecision] - 1.0), $MachinePrecision]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          \mathbf{if}\;a \cdot a \leq 1.1 \cdot 10^{+81}:\\
          \;\;\;\;\left(\mathsf{fma}\left(b, b, 4\right) \cdot b\right) \cdot b - 1\\
          
          \mathbf{else}:\\
          \;\;\;\;\left(a \cdot a\right) \cdot \left(a \cdot a\right) - 1\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 2 regimes
          2. if (*.f64 a a) < 1.09999999999999993e81

            1. Initial program 99.9%

              \[\left({\left(a \cdot a + b \cdot b\right)}^{2} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
            2. Add Preprocessing
            3. Taylor expanded in a around 0

              \[\leadsto \color{blue}{\left(2 \cdot \left({a}^{2} \cdot {b}^{2}\right) + \left(4 \cdot {b}^{2} + {b}^{4}\right)\right)} - 1 \]
            4. Step-by-step derivation
              1. associate-+r+N/A

                \[\leadsto \color{blue}{\left(\left(2 \cdot \left({a}^{2} \cdot {b}^{2}\right) + 4 \cdot {b}^{2}\right) + {b}^{4}\right)} - 1 \]
              2. associate-*r*N/A

                \[\leadsto \left(\left(\color{blue}{\left(2 \cdot {a}^{2}\right) \cdot {b}^{2}} + 4 \cdot {b}^{2}\right) + {b}^{4}\right) - 1 \]
              3. distribute-rgt-inN/A

                \[\leadsto \left(\color{blue}{{b}^{2} \cdot \left(2 \cdot {a}^{2} + 4\right)} + {b}^{4}\right) - 1 \]
              4. +-commutativeN/A

                \[\leadsto \left({b}^{2} \cdot \color{blue}{\left(4 + 2 \cdot {a}^{2}\right)} + {b}^{4}\right) - 1 \]
              5. metadata-evalN/A

                \[\leadsto \left({b}^{2} \cdot \left(4 + 2 \cdot {a}^{2}\right) + {b}^{\color{blue}{\left(2 \cdot 2\right)}}\right) - 1 \]
              6. pow-sqrN/A

                \[\leadsto \left({b}^{2} \cdot \left(4 + 2 \cdot {a}^{2}\right) + \color{blue}{{b}^{2} \cdot {b}^{2}}\right) - 1 \]
              7. distribute-lft-inN/A

                \[\leadsto \color{blue}{{b}^{2} \cdot \left(\left(4 + 2 \cdot {a}^{2}\right) + {b}^{2}\right)} - 1 \]
              8. associate-+r+N/A

                \[\leadsto {b}^{2} \cdot \color{blue}{\left(4 + \left(2 \cdot {a}^{2} + {b}^{2}\right)\right)} - 1 \]
              9. *-commutativeN/A

                \[\leadsto \color{blue}{\left(4 + \left(2 \cdot {a}^{2} + {b}^{2}\right)\right) \cdot {b}^{2}} - 1 \]
              10. unpow2N/A

                \[\leadsto \left(4 + \left(2 \cdot {a}^{2} + {b}^{2}\right)\right) \cdot \color{blue}{\left(b \cdot b\right)} - 1 \]
              11. associate-*r*N/A

                \[\leadsto \color{blue}{\left(\left(4 + \left(2 \cdot {a}^{2} + {b}^{2}\right)\right) \cdot b\right) \cdot b} - 1 \]
              12. lower-*.f64N/A

                \[\leadsto \color{blue}{\left(\left(4 + \left(2 \cdot {a}^{2} + {b}^{2}\right)\right) \cdot b\right) \cdot b} - 1 \]
            5. Applied rewrites95.6%

              \[\leadsto \color{blue}{\left(\mathsf{fma}\left(b, b, \mathsf{fma}\left(a \cdot a, 2, 4\right)\right) \cdot b\right) \cdot b} - 1 \]
            6. Taylor expanded in a around 0

              \[\leadsto \left(b \cdot \left(4 + {b}^{2}\right)\right) \cdot b - 1 \]
            7. Step-by-step derivation
              1. Applied rewrites95.5%

                \[\leadsto \left(\mathsf{fma}\left(b, b, 4\right) \cdot b\right) \cdot b - 1 \]

              if 1.09999999999999993e81 < (*.f64 a a)

              1. Initial program 99.9%

                \[\left({\left(a \cdot a + b \cdot b\right)}^{2} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
              2. Add Preprocessing
              3. Taylor expanded in a around inf

                \[\leadsto \color{blue}{{a}^{4}} - 1 \]
              4. Step-by-step derivation
                1. lower-pow.f6496.3

                  \[\leadsto \color{blue}{{a}^{4}} - 1 \]
              5. Applied rewrites96.3%

                \[\leadsto \color{blue}{{a}^{4}} - 1 \]
              6. Step-by-step derivation
                1. Applied rewrites96.2%

                  \[\leadsto \left(a \cdot a\right) \cdot \color{blue}{\left(a \cdot a\right)} - 1 \]
              7. Recombined 2 regimes into one program.
              8. Add Preprocessing

              Alternative 6: 85.2% accurate, 4.4× speedup?

              \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \cdot b \leq 4.5 \cdot 10^{+307}:\\ \;\;\;\;\left(a \cdot a\right) \cdot \left(a \cdot a\right) - 1\\ \mathbf{else}:\\ \;\;\;\;4 \cdot \left(b \cdot b\right) - 1\\ \end{array} \end{array} \]
              (FPCore (a b)
               :precision binary64
               (if (<= (* b b) 4.5e+307)
                 (- (* (* a a) (* a a)) 1.0)
                 (- (* 4.0 (* b b)) 1.0)))
              double code(double a, double b) {
              	double tmp;
              	if ((b * b) <= 4.5e+307) {
              		tmp = ((a * a) * (a * a)) - 1.0;
              	} else {
              		tmp = (4.0 * (b * b)) - 1.0;
              	}
              	return tmp;
              }
              
              real(8) function code(a, b)
                  real(8), intent (in) :: a
                  real(8), intent (in) :: b
                  real(8) :: tmp
                  if ((b * b) <= 4.5d+307) then
                      tmp = ((a * a) * (a * a)) - 1.0d0
                  else
                      tmp = (4.0d0 * (b * b)) - 1.0d0
                  end if
                  code = tmp
              end function
              
              public static double code(double a, double b) {
              	double tmp;
              	if ((b * b) <= 4.5e+307) {
              		tmp = ((a * a) * (a * a)) - 1.0;
              	} else {
              		tmp = (4.0 * (b * b)) - 1.0;
              	}
              	return tmp;
              }
              
              def code(a, b):
              	tmp = 0
              	if (b * b) <= 4.5e+307:
              		tmp = ((a * a) * (a * a)) - 1.0
              	else:
              		tmp = (4.0 * (b * b)) - 1.0
              	return tmp
              
              function code(a, b)
              	tmp = 0.0
              	if (Float64(b * b) <= 4.5e+307)
              		tmp = Float64(Float64(Float64(a * a) * Float64(a * a)) - 1.0);
              	else
              		tmp = Float64(Float64(4.0 * Float64(b * b)) - 1.0);
              	end
              	return tmp
              end
              
              function tmp_2 = code(a, b)
              	tmp = 0.0;
              	if ((b * b) <= 4.5e+307)
              		tmp = ((a * a) * (a * a)) - 1.0;
              	else
              		tmp = (4.0 * (b * b)) - 1.0;
              	end
              	tmp_2 = tmp;
              end
              
              code[a_, b_] := If[LessEqual[N[(b * b), $MachinePrecision], 4.5e+307], N[(N[(N[(a * a), $MachinePrecision] * N[(a * a), $MachinePrecision]), $MachinePrecision] - 1.0), $MachinePrecision], N[(N[(4.0 * N[(b * b), $MachinePrecision]), $MachinePrecision] - 1.0), $MachinePrecision]]
              
              \begin{array}{l}
              
              \\
              \begin{array}{l}
              \mathbf{if}\;b \cdot b \leq 4.5 \cdot 10^{+307}:\\
              \;\;\;\;\left(a \cdot a\right) \cdot \left(a \cdot a\right) - 1\\
              
              \mathbf{else}:\\
              \;\;\;\;4 \cdot \left(b \cdot b\right) - 1\\
              
              
              \end{array}
              \end{array}
              
              Derivation
              1. Split input into 2 regimes
              2. if (*.f64 b b) < 4.50000000000000025e307

                1. Initial program 99.8%

                  \[\left({\left(a \cdot a + b \cdot b\right)}^{2} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
                2. Add Preprocessing
                3. Taylor expanded in a around inf

                  \[\leadsto \color{blue}{{a}^{4}} - 1 \]
                4. Step-by-step derivation
                  1. lower-pow.f6485.6

                    \[\leadsto \color{blue}{{a}^{4}} - 1 \]
                5. Applied rewrites85.6%

                  \[\leadsto \color{blue}{{a}^{4}} - 1 \]
                6. Step-by-step derivation
                  1. Applied rewrites85.4%

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

                  if 4.50000000000000025e307 < (*.f64 b b)

                  1. Initial program 100.0%

                    \[\left({\left(a \cdot a + b \cdot b\right)}^{2} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
                  2. Add Preprocessing
                  3. Taylor expanded in a around 0

                    \[\leadsto \color{blue}{\left(4 \cdot {b}^{2} + {b}^{4}\right)} - 1 \]
                  4. Step-by-step derivation
                    1. *-commutativeN/A

                      \[\leadsto \left(\color{blue}{{b}^{2} \cdot 4} + {b}^{4}\right) - 1 \]
                    2. lower-fma.f64N/A

                      \[\leadsto \color{blue}{\mathsf{fma}\left({b}^{2}, 4, {b}^{4}\right)} - 1 \]
                    3. unpow2N/A

                      \[\leadsto \mathsf{fma}\left(\color{blue}{b \cdot b}, 4, {b}^{4}\right) - 1 \]
                    4. lower-*.f64N/A

                      \[\leadsto \mathsf{fma}\left(\color{blue}{b \cdot b}, 4, {b}^{4}\right) - 1 \]
                    5. lower-pow.f64100.0

                      \[\leadsto \mathsf{fma}\left(b \cdot b, 4, \color{blue}{{b}^{4}}\right) - 1 \]
                  5. Applied rewrites100.0%

                    \[\leadsto \color{blue}{\mathsf{fma}\left(b \cdot b, 4, {b}^{4}\right)} - 1 \]
                  6. Taylor expanded in b around 0

                    \[\leadsto 4 \cdot \color{blue}{{b}^{2}} - 1 \]
                  7. Step-by-step derivation
                    1. Applied rewrites100.0%

                      \[\leadsto \left(b \cdot b\right) \cdot \color{blue}{4} - 1 \]
                  8. Recombined 2 regimes into one program.
                  9. Final simplification90.1%

                    \[\leadsto \begin{array}{l} \mathbf{if}\;b \cdot b \leq 4.5 \cdot 10^{+307}:\\ \;\;\;\;\left(a \cdot a\right) \cdot \left(a \cdot a\right) - 1\\ \mathbf{else}:\\ \;\;\;\;4 \cdot \left(b \cdot b\right) - 1\\ \end{array} \]
                  10. Add Preprocessing

                  Alternative 7: 52.5% accurate, 9.4× speedup?

                  \[\begin{array}{l} \\ 4 \cdot \left(b \cdot b\right) - 1 \end{array} \]
                  (FPCore (a b) :precision binary64 (- (* 4.0 (* b b)) 1.0))
                  double code(double a, double b) {
                  	return (4.0 * (b * b)) - 1.0;
                  }
                  
                  real(8) function code(a, b)
                      real(8), intent (in) :: a
                      real(8), intent (in) :: b
                      code = (4.0d0 * (b * b)) - 1.0d0
                  end function
                  
                  public static double code(double a, double b) {
                  	return (4.0 * (b * b)) - 1.0;
                  }
                  
                  def code(a, b):
                  	return (4.0 * (b * b)) - 1.0
                  
                  function code(a, b)
                  	return Float64(Float64(4.0 * Float64(b * b)) - 1.0)
                  end
                  
                  function tmp = code(a, b)
                  	tmp = (4.0 * (b * b)) - 1.0;
                  end
                  
                  code[a_, b_] := N[(N[(4.0 * N[(b * b), $MachinePrecision]), $MachinePrecision] - 1.0), $MachinePrecision]
                  
                  \begin{array}{l}
                  
                  \\
                  4 \cdot \left(b \cdot b\right) - 1
                  \end{array}
                  
                  Derivation
                  1. Initial program 99.9%

                    \[\left({\left(a \cdot a + b \cdot b\right)}^{2} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
                  2. Add Preprocessing
                  3. Taylor expanded in a around 0

                    \[\leadsto \color{blue}{\left(4 \cdot {b}^{2} + {b}^{4}\right)} - 1 \]
                  4. Step-by-step derivation
                    1. *-commutativeN/A

                      \[\leadsto \left(\color{blue}{{b}^{2} \cdot 4} + {b}^{4}\right) - 1 \]
                    2. lower-fma.f64N/A

                      \[\leadsto \color{blue}{\mathsf{fma}\left({b}^{2}, 4, {b}^{4}\right)} - 1 \]
                    3. unpow2N/A

                      \[\leadsto \mathsf{fma}\left(\color{blue}{b \cdot b}, 4, {b}^{4}\right) - 1 \]
                    4. lower-*.f64N/A

                      \[\leadsto \mathsf{fma}\left(\color{blue}{b \cdot b}, 4, {b}^{4}\right) - 1 \]
                    5. lower-pow.f6468.5

                      \[\leadsto \mathsf{fma}\left(b \cdot b, 4, \color{blue}{{b}^{4}}\right) - 1 \]
                  5. Applied rewrites68.5%

                    \[\leadsto \color{blue}{\mathsf{fma}\left(b \cdot b, 4, {b}^{4}\right)} - 1 \]
                  6. Taylor expanded in b around 0

                    \[\leadsto 4 \cdot \color{blue}{{b}^{2}} - 1 \]
                  7. Step-by-step derivation
                    1. Applied rewrites56.4%

                      \[\leadsto \left(b \cdot b\right) \cdot \color{blue}{4} - 1 \]
                    2. Final simplification56.4%

                      \[\leadsto 4 \cdot \left(b \cdot b\right) - 1 \]
                    3. Add Preprocessing

                    Reproduce

                    ?
                    herbie shell --seed 2024297 
                    (FPCore (a b)
                      :name "Bouland and Aaronson, Equation (26)"
                      :precision binary64
                      (- (+ (pow (+ (* a a) (* b b)) 2.0) (* 4.0 (* b b))) 1.0))