Bouland and Aaronson, Equation (26)

Percentage Accurate: 99.9% → 99.9%
Time: 12.1s
Alternatives: 9
Speedup: N/A×

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 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: 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: 99.9% accurate, 3.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \mathsf{fma}\left(a, a, b \cdot b\right)\\ \mathsf{fma}\left(t\_0, t\_0, \mathsf{fma}\left(b, b \cdot 4, -1\right)\right) \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (let* ((t_0 (fma a a (* b b)))) (fma t_0 t_0 (fma b (* b 4.0) -1.0))))
double code(double a, double b) {
	double t_0 = fma(a, a, (b * b));
	return fma(t_0, t_0, fma(b, (b * 4.0), -1.0));
}
function code(a, b)
	t_0 = fma(a, a, Float64(b * b))
	return fma(t_0, t_0, fma(b, Float64(b * 4.0), -1.0))
end
code[a_, b_] := Block[{t$95$0 = N[(a * a + N[(b * b), $MachinePrecision]), $MachinePrecision]}, N[(t$95$0 * t$95$0 + N[(b * N[(b * 4.0), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \mathsf{fma}\left(a, a, b \cdot b\right)\\
\mathsf{fma}\left(t\_0, t\_0, \mathsf{fma}\left(b, b \cdot 4, -1\right)\right)
\end{array}
\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. Step-by-step derivation
    1. lift-*.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(a, a, b \cdot b\right), \color{blue}{\mathsf{fma}\left(a, a, b \cdot b\right)}, 4 \cdot \left(b \cdot b\right) - 1\right) \]
    17. sub-negN/A

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

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

Alternative 2: 51.4% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(b \cdot b\right) \cdot 4\\ \mathbf{if}\;{\left(b \cdot b + a \cdot a\right)}^{2} + t\_0 \leq 5 \cdot 10^{-9}:\\ \;\;\;\;-1\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (let* ((t_0 (* (* b b) 4.0)))
   (if (<= (+ (pow (+ (* b b) (* a a)) 2.0) t_0) 5e-9) -1.0 t_0)))
double code(double a, double b) {
	double t_0 = (b * b) * 4.0;
	double tmp;
	if ((pow(((b * b) + (a * a)), 2.0) + t_0) <= 5e-9) {
		tmp = -1.0;
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (b * b) * 4.0d0
    if (((((b * b) + (a * a)) ** 2.0d0) + t_0) <= 5d-9) then
        tmp = -1.0d0
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double t_0 = (b * b) * 4.0;
	double tmp;
	if ((Math.pow(((b * b) + (a * a)), 2.0) + t_0) <= 5e-9) {
		tmp = -1.0;
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(a, b):
	t_0 = (b * b) * 4.0
	tmp = 0
	if (math.pow(((b * b) + (a * a)), 2.0) + t_0) <= 5e-9:
		tmp = -1.0
	else:
		tmp = t_0
	return tmp
function code(a, b)
	t_0 = Float64(Float64(b * b) * 4.0)
	tmp = 0.0
	if (Float64((Float64(Float64(b * b) + Float64(a * a)) ^ 2.0) + t_0) <= 5e-9)
		tmp = -1.0;
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(a, b)
	t_0 = (b * b) * 4.0;
	tmp = 0.0;
	if (((((b * b) + (a * a)) ^ 2.0) + t_0) <= 5e-9)
		tmp = -1.0;
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[a_, b_] := Block[{t$95$0 = N[(N[(b * b), $MachinePrecision] * 4.0), $MachinePrecision]}, If[LessEqual[N[(N[Power[N[(N[(b * b), $MachinePrecision] + N[(a * a), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision] + t$95$0), $MachinePrecision], 5e-9], -1.0, t$95$0]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(b \cdot b\right) \cdot 4\\
\mathbf{if}\;{\left(b \cdot b + a \cdot a\right)}^{2} + t\_0 \leq 5 \cdot 10^{-9}:\\
\;\;\;\;-1\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (pow.f64 (+.f64 (*.f64 a a) (*.f64 b b)) #s(literal 2 binary64)) (*.f64 #s(literal 4 binary64) (*.f64 b b))) < 5.0000000000000001e-9

    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 b around 0

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

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

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

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

        \[\leadsto \color{blue}{\left(a \cdot a\right)} \cdot {a}^{2} + \left(\mathsf{neg}\left(1\right)\right) \]
      5. associate-*l*N/A

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

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

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

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

        \[\leadsto \mathsf{fma}\left(a, a \cdot \color{blue}{\left(a \cdot a\right)}, \mathsf{neg}\left(1\right)\right) \]
      10. metadata-eval99.7

        \[\leadsto \mathsf{fma}\left(a, a \cdot \left(a \cdot a\right), \color{blue}{-1}\right) \]
    5. Applied rewrites99.7%

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

      \[\leadsto \color{blue}{-1} \]
    7. Step-by-step derivation
      1. Applied rewrites99.0%

        \[\leadsto \color{blue}{-1} \]

      if 5.0000000000000001e-9 < (+.f64 (pow.f64 (+.f64 (*.f64 a a) (*.f64 b b)) #s(literal 2 binary64)) (*.f64 #s(literal 4 binary64) (*.f64 b b)))

      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. sub-negN/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \mathsf{fma}\left(b, b \cdot \color{blue}{\mathsf{fma}\left(b, b, 4\right)}, \mathsf{neg}\left(1\right)\right) \]
        16. metadata-eval59.1

          \[\leadsto \mathsf{fma}\left(b, b \cdot \mathsf{fma}\left(b, b, 4\right), \color{blue}{-1}\right) \]
      5. Applied rewrites59.1%

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

        \[\leadsto \color{blue}{4 \cdot {b}^{2} - 1} \]
      7. Step-by-step derivation
        1. sub-negN/A

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

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

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

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

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

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

          \[\leadsto \mathsf{fma}\left(b, \color{blue}{b \cdot 4}, -1\right) \]
        8. lower-*.f6437.3

          \[\leadsto \mathsf{fma}\left(b, \color{blue}{b \cdot 4}, -1\right) \]
      8. Applied rewrites37.3%

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

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

          \[\leadsto \color{blue}{{b}^{2} \cdot 4} \]
        2. lower-*.f64N/A

          \[\leadsto \color{blue}{{b}^{2} \cdot 4} \]
        3. unpow2N/A

          \[\leadsto \color{blue}{\left(b \cdot b\right)} \cdot 4 \]
        4. lower-*.f6437.9

          \[\leadsto \color{blue}{\left(b \cdot b\right)} \cdot 4 \]
      11. Applied rewrites37.9%

        \[\leadsto \color{blue}{\left(b \cdot b\right) \cdot 4} \]
    8. Recombined 2 regimes into one program.
    9. Final simplification52.2%

      \[\leadsto \begin{array}{l} \mathbf{if}\;{\left(b \cdot b + a \cdot a\right)}^{2} + \left(b \cdot b\right) \cdot 4 \leq 5 \cdot 10^{-9}:\\ \;\;\;\;-1\\ \mathbf{else}:\\ \;\;\;\;\left(b \cdot b\right) \cdot 4\\ \end{array} \]
    10. Add Preprocessing

    Alternative 3: 98.0% accurate, 3.3× speedup?

    \[\begin{array}{l} \\ \mathsf{fma}\left(\mathsf{fma}\left(a, a, b \cdot b\right), b \cdot \mathsf{fma}\left(a, \frac{a}{b}, b\right), -1\right) \end{array} \]
    (FPCore (a b)
     :precision binary64
     (fma (fma a a (* b b)) (* b (fma a (/ a b) b)) -1.0))
    double code(double a, double b) {
    	return fma(fma(a, a, (b * b)), (b * fma(a, (a / b), b)), -1.0);
    }
    
    function code(a, b)
    	return fma(fma(a, a, Float64(b * b)), Float64(b * fma(a, Float64(a / b), b)), -1.0)
    end
    
    code[a_, b_] := N[(N[(a * a + N[(b * b), $MachinePrecision]), $MachinePrecision] * N[(b * N[(a * N[(a / b), $MachinePrecision] + b), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \mathsf{fma}\left(\mathsf{fma}\left(a, a, b \cdot b\right), b \cdot \mathsf{fma}\left(a, \frac{a}{b}, b\right), -1\right)
    \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. Step-by-step derivation
      1. lift-*.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(a, a, b \cdot b\right), \color{blue}{\mathsf{fma}\left(a, a, b \cdot b\right)}, 4 \cdot \left(b \cdot b\right) - 1\right) \]
      17. sub-negN/A

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(a, a, b \cdot b\right), b \cdot \left(b \cdot \mathsf{fma}\left(a, \frac{a}{\color{blue}{b \cdot b}}, 1\right)\right), \mathsf{fma}\left(b, b \cdot 4, -1\right)\right) \]
      11. lower-*.f6482.2

        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(a, a, b \cdot b\right), b \cdot \left(b \cdot \mathsf{fma}\left(a, \frac{a}{\color{blue}{b \cdot b}}, 1\right)\right), \mathsf{fma}\left(b, b \cdot 4, -1\right)\right) \]
    7. Applied rewrites82.2%

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(a, a, b \cdot b\right), b \cdot \left(\color{blue}{a \cdot \frac{a}{b}} + b \cdot 1\right), \mathsf{fma}\left(b, b \cdot 4, -1\right)\right) \]
      10. *-rgt-identityN/A

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

        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(a, a, b \cdot b\right), b \cdot \color{blue}{\mathsf{fma}\left(a, \frac{a}{b}, b\right)}, \mathsf{fma}\left(b, b \cdot 4, -1\right)\right) \]
      12. lower-/.f6499.5

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

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

      \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(a, a, b \cdot b\right), b \cdot \mathsf{fma}\left(a, \frac{a}{b}, b\right), \color{blue}{-1}\right) \]
    12. Step-by-step derivation
      1. Applied rewrites99.5%

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

      Alternative 4: 97.8% accurate, 3.4× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \cdot b \leq 200000000000:\\ \;\;\;\;\mathsf{fma}\left(a, a \cdot \left(a \cdot a\right), -1\right)\\ \mathbf{else}:\\ \;\;\;\;b \cdot \left(b \cdot \mathsf{fma}\left(b, b, \left(a \cdot a\right) \cdot 2\right)\right)\\ \end{array} \end{array} \]
      (FPCore (a b)
       :precision binary64
       (if (<= (* b b) 200000000000.0)
         (fma a (* a (* a a)) -1.0)
         (* b (* b (fma b b (* (* a a) 2.0))))))
      double code(double a, double b) {
      	double tmp;
      	if ((b * b) <= 200000000000.0) {
      		tmp = fma(a, (a * (a * a)), -1.0);
      	} else {
      		tmp = b * (b * fma(b, b, ((a * a) * 2.0)));
      	}
      	return tmp;
      }
      
      function code(a, b)
      	tmp = 0.0
      	if (Float64(b * b) <= 200000000000.0)
      		tmp = fma(a, Float64(a * Float64(a * a)), -1.0);
      	else
      		tmp = Float64(b * Float64(b * fma(b, b, Float64(Float64(a * a) * 2.0))));
      	end
      	return tmp
      end
      
      code[a_, b_] := If[LessEqual[N[(b * b), $MachinePrecision], 200000000000.0], N[(a * N[(a * N[(a * a), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision], N[(b * N[(b * N[(b * b + N[(N[(a * a), $MachinePrecision] * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;b \cdot b \leq 200000000000:\\
      \;\;\;\;\mathsf{fma}\left(a, a \cdot \left(a \cdot a\right), -1\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;b \cdot \left(b \cdot \mathsf{fma}\left(b, b, \left(a \cdot a\right) \cdot 2\right)\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (*.f64 b b) < 2e11

        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 b around 0

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

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

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

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

            \[\leadsto \color{blue}{\left(a \cdot a\right)} \cdot {a}^{2} + \left(\mathsf{neg}\left(1\right)\right) \]
          5. associate-*l*N/A

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

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

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

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

            \[\leadsto \mathsf{fma}\left(a, a \cdot \color{blue}{\left(a \cdot a\right)}, \mathsf{neg}\left(1\right)\right) \]
          10. metadata-eval99.8

            \[\leadsto \mathsf{fma}\left(a, a \cdot \left(a \cdot a\right), \color{blue}{-1}\right) \]
        5. Applied rewrites99.8%

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

        if 2e11 < (*.f64 b b)

        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 b around inf

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

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

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

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

            \[\leadsto b \cdot \left(b \cdot \mathsf{fma}\left(b, b, 2 \cdot \color{blue}{\left(a \cdot a\right)}\right)\right) \]
          3. lower-*.f6499.2

            \[\leadsto b \cdot \left(b \cdot \mathsf{fma}\left(b, b, 2 \cdot \color{blue}{\left(a \cdot a\right)}\right)\right) \]
        7. Applied rewrites99.2%

          \[\leadsto b \cdot \left(b \cdot \mathsf{fma}\left(b, b, \color{blue}{2 \cdot \left(a \cdot a\right)}\right)\right) \]
      3. Recombined 2 regimes into one program.
      4. Final simplification99.5%

        \[\leadsto \begin{array}{l} \mathbf{if}\;b \cdot b \leq 200000000000:\\ \;\;\;\;\mathsf{fma}\left(a, a \cdot \left(a \cdot a\right), -1\right)\\ \mathbf{else}:\\ \;\;\;\;b \cdot \left(b \cdot \mathsf{fma}\left(b, b, \left(a \cdot a\right) \cdot 2\right)\right)\\ \end{array} \]
      5. Add Preprocessing

      Alternative 5: 93.9% accurate, 4.5× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \cdot a \leq 10^{-21}:\\ \;\;\;\;\mathsf{fma}\left(b, b \cdot \mathsf{fma}\left(b, b, 4\right), -1\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a, a \cdot \left(a \cdot a\right), -1\right)\\ \end{array} \end{array} \]
      (FPCore (a b)
       :precision binary64
       (if (<= (* a a) 1e-21)
         (fma b (* b (fma b b 4.0)) -1.0)
         (fma a (* a (* a a)) -1.0)))
      double code(double a, double b) {
      	double tmp;
      	if ((a * a) <= 1e-21) {
      		tmp = fma(b, (b * fma(b, b, 4.0)), -1.0);
      	} else {
      		tmp = fma(a, (a * (a * a)), -1.0);
      	}
      	return tmp;
      }
      
      function code(a, b)
      	tmp = 0.0
      	if (Float64(a * a) <= 1e-21)
      		tmp = fma(b, Float64(b * fma(b, b, 4.0)), -1.0);
      	else
      		tmp = fma(a, Float64(a * Float64(a * a)), -1.0);
      	end
      	return tmp
      end
      
      code[a_, b_] := If[LessEqual[N[(a * a), $MachinePrecision], 1e-21], N[(b * N[(b * N[(b * b + 4.0), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision], N[(a * N[(a * N[(a * a), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;a \cdot a \leq 10^{-21}:\\
      \;\;\;\;\mathsf{fma}\left(b, b \cdot \mathsf{fma}\left(b, b, 4\right), -1\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\mathsf{fma}\left(a, a \cdot \left(a \cdot a\right), -1\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (*.f64 a a) < 9.99999999999999908e-22

        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. sub-negN/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \mathsf{fma}\left(b, b \cdot \color{blue}{\mathsf{fma}\left(b, b, 4\right)}, \mathsf{neg}\left(1\right)\right) \]
          16. metadata-eval99.9

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

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

        if 9.99999999999999908e-22 < (*.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 b around 0

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

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

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

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

            \[\leadsto \color{blue}{\left(a \cdot a\right)} \cdot {a}^{2} + \left(\mathsf{neg}\left(1\right)\right) \]
          5. associate-*l*N/A

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

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

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

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

            \[\leadsto \mathsf{fma}\left(a, a \cdot \color{blue}{\left(a \cdot a\right)}, \mathsf{neg}\left(1\right)\right) \]
          10. metadata-eval94.1

            \[\leadsto \mathsf{fma}\left(a, a \cdot \left(a \cdot a\right), \color{blue}{-1}\right) \]
        5. Applied rewrites94.1%

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

      Alternative 6: 94.3% accurate, 4.7× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \cdot b \leq 200000000000:\\ \;\;\;\;\mathsf{fma}\left(a, a \cdot \left(a \cdot a\right), -1\right)\\ \mathbf{else}:\\ \;\;\;\;b \cdot \left(b \cdot \left(b \cdot b\right)\right)\\ \end{array} \end{array} \]
      (FPCore (a b)
       :precision binary64
       (if (<= (* b b) 200000000000.0)
         (fma a (* a (* a a)) -1.0)
         (* b (* b (* b b)))))
      double code(double a, double b) {
      	double tmp;
      	if ((b * b) <= 200000000000.0) {
      		tmp = fma(a, (a * (a * a)), -1.0);
      	} else {
      		tmp = b * (b * (b * b));
      	}
      	return tmp;
      }
      
      function code(a, b)
      	tmp = 0.0
      	if (Float64(b * b) <= 200000000000.0)
      		tmp = fma(a, Float64(a * Float64(a * a)), -1.0);
      	else
      		tmp = Float64(b * Float64(b * Float64(b * b)));
      	end
      	return tmp
      end
      
      code[a_, b_] := If[LessEqual[N[(b * b), $MachinePrecision], 200000000000.0], N[(a * N[(a * N[(a * a), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision], N[(b * N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;b \cdot b \leq 200000000000:\\
      \;\;\;\;\mathsf{fma}\left(a, a \cdot \left(a \cdot a\right), -1\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;b \cdot \left(b \cdot \left(b \cdot b\right)\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (*.f64 b b) < 2e11

        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 b around 0

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

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

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

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

            \[\leadsto \color{blue}{\left(a \cdot a\right)} \cdot {a}^{2} + \left(\mathsf{neg}\left(1\right)\right) \]
          5. associate-*l*N/A

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

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

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

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

            \[\leadsto \mathsf{fma}\left(a, a \cdot \color{blue}{\left(a \cdot a\right)}, \mathsf{neg}\left(1\right)\right) \]
          10. metadata-eval99.8

            \[\leadsto \mathsf{fma}\left(a, a \cdot \left(a \cdot a\right), \color{blue}{-1}\right) \]
        5. Applied rewrites99.8%

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

        if 2e11 < (*.f64 b b)

        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 b around inf

          \[\leadsto \color{blue}{{b}^{4}} \]
        4. Step-by-step derivation
          1. metadata-evalN/A

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

            \[\leadsto \color{blue}{{b}^{2} \cdot {b}^{2}} \]
          3. unpow2N/A

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

            \[\leadsto \color{blue}{b \cdot \left(b \cdot {b}^{2}\right)} \]
          5. lower-*.f64N/A

            \[\leadsto \color{blue}{b \cdot \left(b \cdot {b}^{2}\right)} \]
          6. lower-*.f64N/A

            \[\leadsto b \cdot \color{blue}{\left(b \cdot {b}^{2}\right)} \]
          7. unpow2N/A

            \[\leadsto b \cdot \left(b \cdot \color{blue}{\left(b \cdot b\right)}\right) \]
          8. lower-*.f6493.6

            \[\leadsto b \cdot \left(b \cdot \color{blue}{\left(b \cdot b\right)}\right) \]
        5. Applied rewrites93.6%

          \[\leadsto \color{blue}{b \cdot \left(b \cdot \left(b \cdot b\right)\right)} \]
      3. Recombined 2 regimes into one program.
      4. Add Preprocessing

      Alternative 7: 82.3% accurate, 4.8× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \cdot a \leq 0.0001:\\ \;\;\;\;\mathsf{fma}\left(b, b \cdot 4, -1\right)\\ \mathbf{else}:\\ \;\;\;\;a \cdot \left(a \cdot \left(a \cdot a\right)\right)\\ \end{array} \end{array} \]
      (FPCore (a b)
       :precision binary64
       (if (<= (* a a) 0.0001) (fma b (* b 4.0) -1.0) (* a (* a (* a a)))))
      double code(double a, double b) {
      	double tmp;
      	if ((a * a) <= 0.0001) {
      		tmp = fma(b, (b * 4.0), -1.0);
      	} else {
      		tmp = a * (a * (a * a));
      	}
      	return tmp;
      }
      
      function code(a, b)
      	tmp = 0.0
      	if (Float64(a * a) <= 0.0001)
      		tmp = fma(b, Float64(b * 4.0), -1.0);
      	else
      		tmp = Float64(a * Float64(a * Float64(a * a)));
      	end
      	return tmp
      end
      
      code[a_, b_] := If[LessEqual[N[(a * a), $MachinePrecision], 0.0001], N[(b * N[(b * 4.0), $MachinePrecision] + -1.0), $MachinePrecision], N[(a * N[(a * N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;a \cdot a \leq 0.0001:\\
      \;\;\;\;\mathsf{fma}\left(b, b \cdot 4, -1\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;a \cdot \left(a \cdot \left(a \cdot a\right)\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (*.f64 a a) < 1.00000000000000005e-4

        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. sub-negN/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \mathsf{fma}\left(b, b \cdot \color{blue}{\mathsf{fma}\left(b, b, 4\right)}, \mathsf{neg}\left(1\right)\right) \]
          16. metadata-eval99.6

            \[\leadsto \mathsf{fma}\left(b, b \cdot \mathsf{fma}\left(b, b, 4\right), \color{blue}{-1}\right) \]
        5. Applied rewrites99.6%

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

          \[\leadsto \color{blue}{4 \cdot {b}^{2} - 1} \]
        7. Step-by-step derivation
          1. sub-negN/A

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

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

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

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

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

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

            \[\leadsto \mathsf{fma}\left(b, \color{blue}{b \cdot 4}, -1\right) \]
          8. lower-*.f6479.5

            \[\leadsto \mathsf{fma}\left(b, \color{blue}{b \cdot 4}, -1\right) \]
        8. Applied rewrites79.5%

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

        if 1.00000000000000005e-4 < (*.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

          \[\leadsto \color{blue}{{a}^{4}} \]
        4. Step-by-step derivation
          1. metadata-evalN/A

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

            \[\leadsto \color{blue}{{a}^{2} \cdot {a}^{2}} \]
          3. unpow2N/A

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

            \[\leadsto \color{blue}{a \cdot \left(a \cdot {a}^{2}\right)} \]
          5. lower-*.f64N/A

            \[\leadsto \color{blue}{a \cdot \left(a \cdot {a}^{2}\right)} \]
          6. lower-*.f64N/A

            \[\leadsto a \cdot \color{blue}{\left(a \cdot {a}^{2}\right)} \]
          7. unpow2N/A

            \[\leadsto a \cdot \left(a \cdot \color{blue}{\left(a \cdot a\right)}\right) \]
          8. lower-*.f6493.5

            \[\leadsto a \cdot \left(a \cdot \color{blue}{\left(a \cdot a\right)}\right) \]
        5. Applied rewrites93.5%

          \[\leadsto \color{blue}{a \cdot \left(a \cdot \left(a \cdot a\right)\right)} \]
      3. Recombined 2 regimes into one program.
      4. Add Preprocessing

      Alternative 8: 51.3% accurate, 10.9× speedup?

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \mathsf{fma}\left(b, b \cdot \color{blue}{\mathsf{fma}\left(b, b, 4\right)}, \mathsf{neg}\left(1\right)\right) \]
        16. metadata-eval68.5

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

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

        \[\leadsto \color{blue}{4 \cdot {b}^{2} - 1} \]
      7. Step-by-step derivation
        1. sub-negN/A

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

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

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

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

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

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

          \[\leadsto \mathsf{fma}\left(b, \color{blue}{b \cdot 4}, -1\right) \]
        8. lower-*.f6451.8

          \[\leadsto \mathsf{fma}\left(b, \color{blue}{b \cdot 4}, -1\right) \]
      8. Applied rewrites51.8%

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

      Alternative 9: 24.9% accurate, 131.0× speedup?

      \[\begin{array}{l} \\ -1 \end{array} \]
      (FPCore (a b) :precision binary64 -1.0)
      double code(double a, double b) {
      	return -1.0;
      }
      
      real(8) function code(a, b)
          real(8), intent (in) :: a
          real(8), intent (in) :: b
          code = -1.0d0
      end function
      
      public static double code(double a, double b) {
      	return -1.0;
      }
      
      def code(a, b):
      	return -1.0
      
      function code(a, b)
      	return -1.0
      end
      
      function tmp = code(a, b)
      	tmp = -1.0;
      end
      
      code[a_, b_] := -1.0
      
      \begin{array}{l}
      
      \\
      -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 b around 0

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

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

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

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

          \[\leadsto \color{blue}{\left(a \cdot a\right)} \cdot {a}^{2} + \left(\mathsf{neg}\left(1\right)\right) \]
        5. associate-*l*N/A

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

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

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

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

          \[\leadsto \mathsf{fma}\left(a, a \cdot \color{blue}{\left(a \cdot a\right)}, \mathsf{neg}\left(1\right)\right) \]
        10. metadata-eval70.2

          \[\leadsto \mathsf{fma}\left(a, a \cdot \left(a \cdot a\right), \color{blue}{-1}\right) \]
      5. Applied rewrites70.2%

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

        \[\leadsto \color{blue}{-1} \]
      7. Step-by-step derivation
        1. Applied rewrites23.8%

          \[\leadsto \color{blue}{-1} \]
        2. Add Preprocessing

        Reproduce

        ?
        herbie shell --seed 2024214 
        (FPCore (a b)
          :name "Bouland and Aaronson, Equation (26)"
          :precision binary64
          (- (+ (pow (+ (* a a) (* b b)) 2.0) (* 4.0 (* b b))) 1.0))