Bouland and Aaronson, Equation (26)

Percentage Accurate: 99.9% → 99.9%
Time: 7.4s
Alternatives: 6
Speedup: 1.0×

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 6 alternatives:

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

Initial Program: 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, 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}
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. Add Preprocessing

Alternative 2: 98.3% accurate, 2.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \cdot b \leq 0.01:\\ \;\;\;\;\mathsf{fma}\left(b \cdot b, 4, \left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a - 1\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\mathsf{fma}\left(b, b, \mathsf{fma}\left(a \cdot a, 2, 4\right)\right) \cdot b\right) \cdot b - 1\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= (* b b) 0.01)
   (fma (* b b) 4.0 (- (* (* (fma (* b b) 2.0 (* a a)) a) a) 1.0))
   (- (* (* (fma b b (fma (* a a) 2.0 4.0)) b) b) 1.0)))
double code(double a, double b) {
	double tmp;
	if ((b * b) <= 0.01) {
		tmp = fma((b * b), 4.0, (((fma((b * b), 2.0, (a * a)) * a) * a) - 1.0));
	} else {
		tmp = ((fma(b, b, fma((a * a), 2.0, 4.0)) * b) * b) - 1.0;
	}
	return tmp;
}
function code(a, b)
	tmp = 0.0
	if (Float64(b * b) <= 0.01)
		tmp = fma(Float64(b * b), 4.0, Float64(Float64(Float64(fma(Float64(b * b), 2.0, Float64(a * a)) * a) * a) - 1.0));
	else
		tmp = Float64(Float64(Float64(fma(b, b, fma(Float64(a * a), 2.0, 4.0)) * b) * b) - 1.0);
	end
	return tmp
end
code[a_, b_] := If[LessEqual[N[(b * b), $MachinePrecision], 0.01], N[(N[(b * b), $MachinePrecision] * 4.0 + N[(N[(N[(N[(N[(b * b), $MachinePrecision] * 2.0 + N[(a * a), $MachinePrecision]), $MachinePrecision] * a), $MachinePrecision] * a), $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[(b * b + N[(N[(a * a), $MachinePrecision] * 2.0 + 4.0), $MachinePrecision]), $MachinePrecision] * b), $MachinePrecision] * b), $MachinePrecision] - 1.0), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \cdot b \leq 0.01:\\
\;\;\;\;\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)\\

\mathbf{else}:\\
\;\;\;\;\left(\mathsf{fma}\left(b, b, \mathsf{fma}\left(a \cdot a, 2, 4\right)\right) \cdot b\right) \cdot b - 1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (*.f64 b b) < 0.0100000000000000002

    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

      \[\leadsto \left(\color{blue}{\left(2 \cdot \left({a}^{2} \cdot {b}^{2}\right) + {a}^{4}\right)} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    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-*.f6499.8

        \[\leadsto \left(\left(\mathsf{fma}\left(b \cdot b, 2, \color{blue}{a \cdot a}\right) \cdot a\right) \cdot a + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    5. Applied rewrites99.8%

      \[\leadsto \left(\color{blue}{\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a} + 4 \cdot \left(b \cdot b\right)\right) - 1 \]
    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--.f6499.8

        \[\leadsto \mathsf{fma}\left(b \cdot b, 4, \color{blue}{\left(\mathsf{fma}\left(b \cdot b, 2, a \cdot a\right) \cdot a\right) \cdot a - 1}\right) \]
    7. Applied rewrites99.8%

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

    if 0.0100000000000000002 < (*.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

      \[\leadsto \color{blue}{\left(2 \cdot \left({a}^{2} \cdot {b}^{2}\right) + \left(4 \cdot {b}^{2} + {b}^{4}\right)\right)} - 1 \]
    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 rewrites97.8%

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

Alternative 3: 98.1% accurate, 3.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \cdot b \leq 0.01:\\ \;\;\;\;\left(a \cdot a\right) \cdot \left(a \cdot a\right) - 1\\ \mathbf{else}:\\ \;\;\;\;\left(\mathsf{fma}\left(b, b, \mathsf{fma}\left(a \cdot a, 2, 4\right)\right) \cdot b\right) \cdot b - 1\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= (* b b) 0.01)
   (- (* (* a a) (* a a)) 1.0)
   (- (* (* (fma b b (fma (* a a) 2.0 4.0)) b) b) 1.0)))
double code(double a, double b) {
	double tmp;
	if ((b * b) <= 0.01) {
		tmp = ((a * a) * (a * a)) - 1.0;
	} else {
		tmp = ((fma(b, b, fma((a * a), 2.0, 4.0)) * b) * b) - 1.0;
	}
	return tmp;
}
function code(a, b)
	tmp = 0.0
	if (Float64(b * b) <= 0.01)
		tmp = Float64(Float64(Float64(a * a) * Float64(a * a)) - 1.0);
	else
		tmp = Float64(Float64(Float64(fma(b, b, fma(Float64(a * a), 2.0, 4.0)) * b) * b) - 1.0);
	end
	return tmp
end
code[a_, b_] := If[LessEqual[N[(b * b), $MachinePrecision], 0.01], N[(N[(N[(a * a), $MachinePrecision] * N[(a * a), $MachinePrecision]), $MachinePrecision] - 1.0), $MachinePrecision], N[(N[(N[(N[(b * b + N[(N[(a * a), $MachinePrecision] * 2.0 + 4.0), $MachinePrecision]), $MachinePrecision] * b), $MachinePrecision] * b), $MachinePrecision] - 1.0), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \cdot b \leq 0.01:\\
\;\;\;\;\left(a \cdot a\right) \cdot \left(a \cdot a\right) - 1\\

\mathbf{else}:\\
\;\;\;\;\left(\mathsf{fma}\left(b, b, \mathsf{fma}\left(a \cdot a, 2, 4\right)\right) \cdot b\right) \cdot b - 1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (*.f64 b b) < 0.0100000000000000002

    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.f6499.6

        \[\leadsto \color{blue}{{a}^{4}} - 1 \]
    5. Applied rewrites99.6%

      \[\leadsto \color{blue}{{a}^{4}} - 1 \]
    6. Step-by-step derivation
      1. Applied rewrites99.5%

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

      if 0.0100000000000000002 < (*.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

        \[\leadsto \color{blue}{\left(2 \cdot \left({a}^{2} \cdot {b}^{2}\right) + \left(4 \cdot {b}^{2} + {b}^{4}\right)\right)} - 1 \]
      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 rewrites97.8%

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

    Alternative 4: 94.2% accurate, 4.2× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \cdot b \leq 0.01:\\ \;\;\;\;\left(a \cdot a\right) \cdot \left(a \cdot a\right) - 1\\ \mathbf{else}:\\ \;\;\;\;\left(\mathsf{fma}\left(b, b, 4\right) \cdot b\right) \cdot b - 1\\ \end{array} \end{array} \]
    (FPCore (a b)
     :precision binary64
     (if (<= (* b b) 0.01)
       (- (* (* a a) (* a a)) 1.0)
       (- (* (* (fma b b 4.0) b) b) 1.0)))
    double code(double a, double b) {
    	double tmp;
    	if ((b * b) <= 0.01) {
    		tmp = ((a * a) * (a * a)) - 1.0;
    	} else {
    		tmp = ((fma(b, b, 4.0) * b) * b) - 1.0;
    	}
    	return tmp;
    }
    
    function code(a, b)
    	tmp = 0.0
    	if (Float64(b * b) <= 0.01)
    		tmp = Float64(Float64(Float64(a * a) * Float64(a * a)) - 1.0);
    	else
    		tmp = Float64(Float64(Float64(fma(b, b, 4.0) * b) * b) - 1.0);
    	end
    	return tmp
    end
    
    code[a_, b_] := If[LessEqual[N[(b * b), $MachinePrecision], 0.01], N[(N[(N[(a * a), $MachinePrecision] * N[(a * a), $MachinePrecision]), $MachinePrecision] - 1.0), $MachinePrecision], N[(N[(N[(N[(b * b + 4.0), $MachinePrecision] * b), $MachinePrecision] * b), $MachinePrecision] - 1.0), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;b \cdot b \leq 0.01:\\
    \;\;\;\;\left(a \cdot a\right) \cdot \left(a \cdot a\right) - 1\\
    
    \mathbf{else}:\\
    \;\;\;\;\left(\mathsf{fma}\left(b, b, 4\right) \cdot b\right) \cdot b - 1\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (*.f64 b b) < 0.0100000000000000002

      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.f6499.6

          \[\leadsto \color{blue}{{a}^{4}} - 1 \]
      5. Applied rewrites99.6%

        \[\leadsto \color{blue}{{a}^{4}} - 1 \]
      6. Step-by-step derivation
        1. Applied rewrites99.5%

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

        if 0.0100000000000000002 < (*.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

          \[\leadsto \color{blue}{\left(2 \cdot \left({a}^{2} \cdot {b}^{2}\right) + \left(4 \cdot {b}^{2} + {b}^{4}\right)\right)} - 1 \]
        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 rewrites97.8%

          \[\leadsto \color{blue}{\left(\mathsf{fma}\left(b, b, \mathsf{fma}\left(a \cdot a, 2, 4\right)\right) \cdot b\right) \cdot b} - 1 \]
        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 rewrites89.7%

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

        Alternative 5: 84.3% accurate, 4.4× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \cdot b \leq 2.2 \cdot 10^{+306}:\\ \;\;\;\;\left(a \cdot a\right) \cdot \left(a \cdot a\right) - 1\\ \mathbf{else}:\\ \;\;\;\;\left(b \cdot b\right) \cdot 4 - 1\\ \end{array} \end{array} \]
        (FPCore (a b)
         :precision binary64
         (if (<= (* b b) 2.2e+306)
           (- (* (* a a) (* a a)) 1.0)
           (- (* (* b b) 4.0) 1.0)))
        double code(double a, double b) {
        	double tmp;
        	if ((b * b) <= 2.2e+306) {
        		tmp = ((a * a) * (a * a)) - 1.0;
        	} else {
        		tmp = ((b * b) * 4.0) - 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) <= 2.2d+306) then
                tmp = ((a * a) * (a * a)) - 1.0d0
            else
                tmp = ((b * b) * 4.0d0) - 1.0d0
            end if
            code = tmp
        end function
        
        public static double code(double a, double b) {
        	double tmp;
        	if ((b * b) <= 2.2e+306) {
        		tmp = ((a * a) * (a * a)) - 1.0;
        	} else {
        		tmp = ((b * b) * 4.0) - 1.0;
        	}
        	return tmp;
        }
        
        def code(a, b):
        	tmp = 0
        	if (b * b) <= 2.2e+306:
        		tmp = ((a * a) * (a * a)) - 1.0
        	else:
        		tmp = ((b * b) * 4.0) - 1.0
        	return tmp
        
        function code(a, b)
        	tmp = 0.0
        	if (Float64(b * b) <= 2.2e+306)
        		tmp = Float64(Float64(Float64(a * a) * Float64(a * a)) - 1.0);
        	else
        		tmp = Float64(Float64(Float64(b * b) * 4.0) - 1.0);
        	end
        	return tmp
        end
        
        function tmp_2 = code(a, b)
        	tmp = 0.0;
        	if ((b * b) <= 2.2e+306)
        		tmp = ((a * a) * (a * a)) - 1.0;
        	else
        		tmp = ((b * b) * 4.0) - 1.0;
        	end
        	tmp_2 = tmp;
        end
        
        code[a_, b_] := If[LessEqual[N[(b * b), $MachinePrecision], 2.2e+306], N[(N[(N[(a * a), $MachinePrecision] * N[(a * a), $MachinePrecision]), $MachinePrecision] - 1.0), $MachinePrecision], N[(N[(N[(b * b), $MachinePrecision] * 4.0), $MachinePrecision] - 1.0), $MachinePrecision]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;b \cdot b \leq 2.2 \cdot 10^{+306}:\\
        \;\;\;\;\left(a \cdot a\right) \cdot \left(a \cdot a\right) - 1\\
        
        \mathbf{else}:\\
        \;\;\;\;\left(b \cdot b\right) \cdot 4 - 1\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if (*.f64 b b) < 2.2e306

          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.f6480.7

              \[\leadsto \color{blue}{{a}^{4}} - 1 \]
          5. Applied rewrites80.7%

            \[\leadsto \color{blue}{{a}^{4}} - 1 \]
          6. Step-by-step derivation
            1. Applied rewrites80.7%

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

            if 2.2e306 < (*.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 rewrites97.4%

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

            Alternative 6: 50.2% accurate, 9.4× speedup?

            \[\begin{array}{l} \\ \left(b \cdot b\right) \cdot 4 - 1 \end{array} \]
            (FPCore (a b) :precision binary64 (- (* (* b b) 4.0) 1.0))
            double code(double a, double b) {
            	return ((b * b) * 4.0) - 1.0;
            }
            
            real(8) function code(a, b)
                real(8), intent (in) :: a
                real(8), intent (in) :: b
                code = ((b * b) * 4.0d0) - 1.0d0
            end function
            
            public static double code(double a, double b) {
            	return ((b * b) * 4.0) - 1.0;
            }
            
            def code(a, b):
            	return ((b * b) * 4.0) - 1.0
            
            function code(a, b)
            	return Float64(Float64(Float64(b * b) * 4.0) - 1.0)
            end
            
            function tmp = code(a, b)
            	tmp = ((b * b) * 4.0) - 1.0;
            end
            
            code[a_, b_] := N[(N[(N[(b * b), $MachinePrecision] * 4.0), $MachinePrecision] - 1.0), $MachinePrecision]
            
            \begin{array}{l}
            
            \\
            \left(b \cdot b\right) \cdot 4 - 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.f6469.8

                \[\leadsto \mathsf{fma}\left(b \cdot b, 4, \color{blue}{{b}^{4}}\right) - 1 \]
            5. Applied rewrites69.8%

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

              \[\leadsto 4 \cdot \color{blue}{{b}^{2}} - 1 \]
            7. Step-by-step derivation
              1. Applied rewrites50.5%

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

              Reproduce

              ?
              herbie shell --seed 2024337 
              (FPCore (a b)
                :name "Bouland and Aaronson, Equation (26)"
                :precision binary64
                (- (+ (pow (+ (* a a) (* b b)) 2.0) (* 4.0 (* b b))) 1.0))