Quadratic roots, wide range

Percentage Accurate: 17.9% → 99.5%
Time: 13.5s
Alternatives: 7
Speedup: 3.6×

Specification

?
\[\left(\left(4.930380657631324 \cdot 10^{-32} < a \land a < 2.028240960365167 \cdot 10^{+31}\right) \land \left(4.930380657631324 \cdot 10^{-32} < b \land b < 2.028240960365167 \cdot 10^{+31}\right)\right) \land \left(4.930380657631324 \cdot 10^{-32} < c \land c < 2.028240960365167 \cdot 10^{+31}\right)\]
\[\begin{array}{l} \\ \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))
double code(double a, double b, double c) {
	return (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = (-b + sqrt(((b * b) - ((4.0d0 * a) * c)))) / (2.0d0 * a)
end function
public static double code(double a, double b, double c) {
	return (-b + Math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
}
def code(a, b, c):
	return (-b + math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a)
function code(a, b, c)
	return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(4.0 * a) * c)))) / Float64(2.0 * a))
end
function tmp = code(a, b, c)
	tmp = (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(4.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 7 alternatives:

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

Initial Program: 17.9% accurate, 1.0× speedup?

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

\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a}
\end{array}

Alternative 1: 99.5% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \frac{\frac{0.5}{a} \cdot \left(a \cdot \left(c \cdot -4\right)\right)}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/ (* (/ 0.5 a) (* a (* c -4.0))) (+ b (sqrt (fma a (* c -4.0) (* b b))))))
double code(double a, double b, double c) {
	return ((0.5 / a) * (a * (c * -4.0))) / (b + sqrt(fma(a, (c * -4.0), (b * b))));
}
function code(a, b, c)
	return Float64(Float64(Float64(0.5 / a) * Float64(a * Float64(c * -4.0))) / Float64(b + sqrt(fma(a, Float64(c * -4.0), Float64(b * b)))))
end
code[a_, b_, c_] := N[(N[(N[(0.5 / a), $MachinePrecision] * N[(a * N[(c * -4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b + N[Sqrt[N[(a * N[(c * -4.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{0.5}{a} \cdot \left(a \cdot \left(c \cdot -4\right)\right)}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}}
\end{array}
Derivation
  1. Initial program 15.6%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Add Preprocessing
  3. Applied rewrites15.6%

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

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

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

      \[\leadsto \frac{\frac{b \cdot b}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}}{a \cdot 2} - \color{blue}{\frac{\frac{\mathsf{fma}\left(b, b, a \cdot \left(4 \cdot c\right)\right)}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}}{a \cdot 2}} \]
    4. sub-divN/A

      \[\leadsto \color{blue}{\frac{\frac{b \cdot b}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} - \frac{\mathsf{fma}\left(b, b, a \cdot \left(4 \cdot c\right)\right)}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}}{a \cdot 2}} \]
    5. clear-numN/A

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

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

      \[\leadsto \frac{1}{\color{blue}{\frac{a \cdot 2}{\frac{b \cdot b}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} - \frac{\mathsf{fma}\left(b, b, a \cdot \left(4 \cdot c\right)\right)}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}}}} \]
  5. Applied rewrites16.1%

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

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

      \[\leadsto \frac{1}{\frac{a \cdot 2}{\frac{\color{blue}{\left(a \cdot c\right) \cdot -4}}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}}} \]
    2. rem-square-sqrtN/A

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

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

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

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

      \[\leadsto \frac{1}{\frac{a \cdot 2}{\frac{a \cdot \left(c \cdot \color{blue}{\left(\sqrt{-4} \cdot \sqrt{-4}\right)}\right)}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}}} \]
    7. rem-square-sqrtN/A

      \[\leadsto \frac{1}{\frac{a \cdot 2}{\frac{a \cdot \left(c \cdot \color{blue}{-4}\right)}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}}} \]
    8. lower-*.f6499.3

      \[\leadsto \frac{1}{\frac{a \cdot 2}{\frac{a \cdot \color{blue}{\left(c \cdot -4\right)}}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}}} \]
  8. Applied rewrites99.3%

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

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

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

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

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

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

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

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

    \[\leadsto \color{blue}{\frac{\frac{0.5}{a} \cdot \left(a \cdot \left(c \cdot -4\right)\right)}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}}} \]
  11. Add Preprocessing

Alternative 2: 99.4% accurate, 0.8× speedup?

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

\\
\frac{-4 \cdot \left(a \cdot c\right)}{a \cdot \left(2 \cdot \left(b + \sqrt{\mathsf{fma}\left(-4, a \cdot c, b \cdot b\right)}\right)\right)}
\end{array}
Derivation
  1. Initial program 15.6%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Add Preprocessing
  3. Applied rewrites15.6%

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

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

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

      \[\leadsto \frac{\frac{b \cdot b}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}}{a \cdot 2} - \color{blue}{\frac{\frac{\mathsf{fma}\left(b, b, a \cdot \left(4 \cdot c\right)\right)}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}}{a \cdot 2}} \]
    4. sub-divN/A

      \[\leadsto \color{blue}{\frac{\frac{b \cdot b}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} - \frac{\mathsf{fma}\left(b, b, a \cdot \left(4 \cdot c\right)\right)}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}}{a \cdot 2}} \]
    5. clear-numN/A

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

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

      \[\leadsto \frac{1}{\color{blue}{\frac{a \cdot 2}{\frac{b \cdot b}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} - \frac{\mathsf{fma}\left(b, b, a \cdot \left(4 \cdot c\right)\right)}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}}}} \]
  5. Applied rewrites16.1%

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

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

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

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

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

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

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

      \[\leadsto \frac{b \cdot b - \mathsf{fma}\left(c, 4 \cdot a, b \cdot b\right)}{\color{blue}{\left(b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}\right) \cdot \left(a \cdot 2\right)}} \]
    8. lower-/.f6416.0

      \[\leadsto \color{blue}{\frac{b \cdot b - \mathsf{fma}\left(c, 4 \cdot a, b \cdot b\right)}{\left(b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}\right) \cdot \left(a \cdot 2\right)}} \]
  7. Applied rewrites16.0%

    \[\leadsto \color{blue}{\frac{b \cdot b - \mathsf{fma}\left(c, a \cdot 4, b \cdot b\right)}{a \cdot \left(2 \cdot \left(b + \sqrt{\mathsf{fma}\left(-4, c \cdot a, b \cdot b\right)}\right)\right)}} \]
  8. Taylor expanded in b around 0

    \[\leadsto \frac{\color{blue}{-4 \cdot \left(a \cdot c\right)}}{a \cdot \left(2 \cdot \left(b + \sqrt{\mathsf{fma}\left(-4, c \cdot a, b \cdot b\right)}\right)\right)} \]
  9. Step-by-step derivation
    1. lower-*.f64N/A

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

      \[\leadsto \frac{-4 \cdot \color{blue}{\left(c \cdot a\right)}}{a \cdot \left(2 \cdot \left(b + \sqrt{\mathsf{fma}\left(-4, c \cdot a, b \cdot b\right)}\right)\right)} \]
    3. lower-*.f6499.5

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

    \[\leadsto \frac{\color{blue}{-4 \cdot \left(c \cdot a\right)}}{a \cdot \left(2 \cdot \left(b + \sqrt{\mathsf{fma}\left(-4, c \cdot a, b \cdot b\right)}\right)\right)} \]
  11. Final simplification99.5%

    \[\leadsto \frac{-4 \cdot \left(a \cdot c\right)}{a \cdot \left(2 \cdot \left(b + \sqrt{\mathsf{fma}\left(-4, a \cdot c, b \cdot b\right)}\right)\right)} \]
  12. Add Preprocessing

Alternative 3: 95.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{c}{-b} - \frac{a \cdot \left(c \cdot c\right)}{b \cdot \left(b \cdot b\right)} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (- (/ c (- b)) (/ (* a (* c c)) (* b (* b b)))))
double code(double a, double b, double c) {
	return (c / -b) - ((a * (c * c)) / (b * (b * b)));
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = (c / -b) - ((a * (c * c)) / (b * (b * b)))
end function
public static double code(double a, double b, double c) {
	return (c / -b) - ((a * (c * c)) / (b * (b * b)));
}
def code(a, b, c):
	return (c / -b) - ((a * (c * c)) / (b * (b * b)))
function code(a, b, c)
	return Float64(Float64(c / Float64(-b)) - Float64(Float64(a * Float64(c * c)) / Float64(b * Float64(b * b))))
end
function tmp = code(a, b, c)
	tmp = (c / -b) - ((a * (c * c)) / (b * (b * b)));
end
code[a_, b_, c_] := N[(N[(c / (-b)), $MachinePrecision] - N[(N[(a * N[(c * c), $MachinePrecision]), $MachinePrecision] / N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{c}{-b} - \frac{a \cdot \left(c \cdot c\right)}{b \cdot \left(b \cdot b\right)}
\end{array}
Derivation
  1. Initial program 15.6%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-sqrt.f64N/A

      \[\leadsto \frac{\left(\mathsf{neg}\left(b\right)\right) + \color{blue}{\sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}}{2 \cdot a} \]
    2. lift--.f64N/A

      \[\leadsto \frac{\left(\mathsf{neg}\left(b\right)\right) + \sqrt{\color{blue}{b \cdot b - \left(4 \cdot a\right) \cdot c}}}{2 \cdot a} \]
    3. flip--N/A

      \[\leadsto \frac{\left(\mathsf{neg}\left(b\right)\right) + \sqrt{\color{blue}{\frac{\left(b \cdot b\right) \cdot \left(b \cdot b\right) - \left(\left(4 \cdot a\right) \cdot c\right) \cdot \left(\left(4 \cdot a\right) \cdot c\right)}{b \cdot b + \left(4 \cdot a\right) \cdot c}}}}{2 \cdot a} \]
    4. clear-numN/A

      \[\leadsto \frac{\left(\mathsf{neg}\left(b\right)\right) + \sqrt{\color{blue}{\frac{1}{\frac{b \cdot b + \left(4 \cdot a\right) \cdot c}{\left(b \cdot b\right) \cdot \left(b \cdot b\right) - \left(\left(4 \cdot a\right) \cdot c\right) \cdot \left(\left(4 \cdot a\right) \cdot c\right)}}}}}{2 \cdot a} \]
    5. sqrt-divN/A

      \[\leadsto \frac{\left(\mathsf{neg}\left(b\right)\right) + \color{blue}{\frac{\sqrt{1}}{\sqrt{\frac{b \cdot b + \left(4 \cdot a\right) \cdot c}{\left(b \cdot b\right) \cdot \left(b \cdot b\right) - \left(\left(4 \cdot a\right) \cdot c\right) \cdot \left(\left(4 \cdot a\right) \cdot c\right)}}}}}{2 \cdot a} \]
    6. metadata-evalN/A

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

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

      \[\leadsto \frac{\left(\mathsf{neg}\left(b\right)\right) + \frac{1}{\color{blue}{\sqrt{\frac{b \cdot b + \left(4 \cdot a\right) \cdot c}{\left(b \cdot b\right) \cdot \left(b \cdot b\right) - \left(\left(4 \cdot a\right) \cdot c\right) \cdot \left(\left(4 \cdot a\right) \cdot c\right)}}}}}{2 \cdot a} \]
    9. clear-numN/A

      \[\leadsto \frac{\left(\mathsf{neg}\left(b\right)\right) + \frac{1}{\sqrt{\color{blue}{\frac{1}{\frac{\left(b \cdot b\right) \cdot \left(b \cdot b\right) - \left(\left(4 \cdot a\right) \cdot c\right) \cdot \left(\left(4 \cdot a\right) \cdot c\right)}{b \cdot b + \left(4 \cdot a\right) \cdot c}}}}}}{2 \cdot a} \]
    10. flip--N/A

      \[\leadsto \frac{\left(\mathsf{neg}\left(b\right)\right) + \frac{1}{\sqrt{\frac{1}{\color{blue}{b \cdot b - \left(4 \cdot a\right) \cdot c}}}}}{2 \cdot a} \]
    11. lift--.f64N/A

      \[\leadsto \frac{\left(\mathsf{neg}\left(b\right)\right) + \frac{1}{\sqrt{\frac{1}{\color{blue}{b \cdot b - \left(4 \cdot a\right) \cdot c}}}}}{2 \cdot a} \]
  4. Applied rewrites16.0%

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

    \[\leadsto \color{blue}{-1 \cdot \frac{c}{b} + -1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}}} \]
  6. Step-by-step derivation
    1. mul-1-negN/A

      \[\leadsto -1 \cdot \frac{c}{b} + \color{blue}{\left(\mathsf{neg}\left(\frac{a \cdot {c}^{2}}{{b}^{3}}\right)\right)} \]
    2. unsub-negN/A

      \[\leadsto \color{blue}{-1 \cdot \frac{c}{b} - \frac{a \cdot {c}^{2}}{{b}^{3}}} \]
    3. lower--.f64N/A

      \[\leadsto \color{blue}{-1 \cdot \frac{c}{b} - \frac{a \cdot {c}^{2}}{{b}^{3}}} \]
    4. associate-*r/N/A

      \[\leadsto \color{blue}{\frac{-1 \cdot c}{b}} - \frac{a \cdot {c}^{2}}{{b}^{3}} \]
    5. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{-1 \cdot c}{b}} - \frac{a \cdot {c}^{2}}{{b}^{3}} \]
    6. mul-1-negN/A

      \[\leadsto \frac{\color{blue}{\mathsf{neg}\left(c\right)}}{b} - \frac{a \cdot {c}^{2}}{{b}^{3}} \]
    7. lower-neg.f64N/A

      \[\leadsto \frac{\color{blue}{\mathsf{neg}\left(c\right)}}{b} - \frac{a \cdot {c}^{2}}{{b}^{3}} \]
    8. lower-/.f64N/A

      \[\leadsto \frac{\mathsf{neg}\left(c\right)}{b} - \color{blue}{\frac{a \cdot {c}^{2}}{{b}^{3}}} \]
    9. lower-*.f64N/A

      \[\leadsto \frac{\mathsf{neg}\left(c\right)}{b} - \frac{\color{blue}{a \cdot {c}^{2}}}{{b}^{3}} \]
    10. unpow2N/A

      \[\leadsto \frac{\mathsf{neg}\left(c\right)}{b} - \frac{a \cdot \color{blue}{\left(c \cdot c\right)}}{{b}^{3}} \]
    11. lower-*.f64N/A

      \[\leadsto \frac{\mathsf{neg}\left(c\right)}{b} - \frac{a \cdot \color{blue}{\left(c \cdot c\right)}}{{b}^{3}} \]
    12. cube-multN/A

      \[\leadsto \frac{\mathsf{neg}\left(c\right)}{b} - \frac{a \cdot \left(c \cdot c\right)}{\color{blue}{b \cdot \left(b \cdot b\right)}} \]
    13. unpow2N/A

      \[\leadsto \frac{\mathsf{neg}\left(c\right)}{b} - \frac{a \cdot \left(c \cdot c\right)}{b \cdot \color{blue}{{b}^{2}}} \]
    14. lower-*.f64N/A

      \[\leadsto \frac{\mathsf{neg}\left(c\right)}{b} - \frac{a \cdot \left(c \cdot c\right)}{\color{blue}{b \cdot {b}^{2}}} \]
    15. unpow2N/A

      \[\leadsto \frac{\mathsf{neg}\left(c\right)}{b} - \frac{a \cdot \left(c \cdot c\right)}{b \cdot \color{blue}{\left(b \cdot b\right)}} \]
    16. lower-*.f6495.1

      \[\leadsto \frac{-c}{b} - \frac{a \cdot \left(c \cdot c\right)}{b \cdot \color{blue}{\left(b \cdot b\right)}} \]
  7. Applied rewrites95.1%

    \[\leadsto \color{blue}{\frac{-c}{b} - \frac{a \cdot \left(c \cdot c\right)}{b \cdot \left(b \cdot b\right)}} \]
  8. Final simplification95.1%

    \[\leadsto \frac{c}{-b} - \frac{a \cdot \left(c \cdot c\right)}{b \cdot \left(b \cdot b\right)} \]
  9. Add Preprocessing

Alternative 4: 95.4% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \frac{\mathsf{fma}\left(c \cdot c, \frac{a}{b \cdot b}, c\right)}{-b} \end{array} \]
(FPCore (a b c) :precision binary64 (/ (fma (* c c) (/ a (* b b)) c) (- b)))
double code(double a, double b, double c) {
	return fma((c * c), (a / (b * b)), c) / -b;
}
function code(a, b, c)
	return Float64(fma(Float64(c * c), Float64(a / Float64(b * b)), c) / Float64(-b))
end
code[a_, b_, c_] := N[(N[(N[(c * c), $MachinePrecision] * N[(a / N[(b * b), $MachinePrecision]), $MachinePrecision] + c), $MachinePrecision] / (-b)), $MachinePrecision]
\begin{array}{l}

\\
\frac{\mathsf{fma}\left(c \cdot c, \frac{a}{b \cdot b}, c\right)}{-b}
\end{array}
Derivation
  1. Initial program 15.6%

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

    \[\leadsto \color{blue}{\frac{-1 \cdot c + -1 \cdot \frac{a \cdot {c}^{2}}{{b}^{2}}}{b}} \]
  4. Step-by-step derivation
    1. distribute-lft-outN/A

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

      \[\leadsto \color{blue}{-1 \cdot \frac{c + \frac{a \cdot {c}^{2}}{{b}^{2}}}{b}} \]
    3. mul-1-negN/A

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

      \[\leadsto \color{blue}{\mathsf{neg}\left(\frac{c + \frac{a \cdot {c}^{2}}{{b}^{2}}}{b}\right)} \]
    5. lower-/.f64N/A

      \[\leadsto \mathsf{neg}\left(\color{blue}{\frac{c + \frac{a \cdot {c}^{2}}{{b}^{2}}}{b}}\right) \]
    6. +-commutativeN/A

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

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

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

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

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

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

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

      \[\leadsto \mathsf{neg}\left(\frac{\mathsf{fma}\left(c \cdot c, \frac{a}{\color{blue}{b \cdot b}}, c\right)}{b}\right) \]
    14. lower-*.f6495.1

      \[\leadsto -\frac{\mathsf{fma}\left(c \cdot c, \frac{a}{\color{blue}{b \cdot b}}, c\right)}{b} \]
  5. Applied rewrites95.1%

    \[\leadsto \color{blue}{-\frac{\mathsf{fma}\left(c \cdot c, \frac{a}{b \cdot b}, c\right)}{b}} \]
  6. Final simplification95.1%

    \[\leadsto \frac{\mathsf{fma}\left(c \cdot c, \frac{a}{b \cdot b}, c\right)}{-b} \]
  7. Add Preprocessing

Alternative 5: 95.2% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \frac{1}{\frac{a}{b} - \frac{b}{c}} \end{array} \]
(FPCore (a b c) :precision binary64 (/ 1.0 (- (/ a b) (/ b c))))
double code(double a, double b, double c) {
	return 1.0 / ((a / b) - (b / c));
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = 1.0d0 / ((a / b) - (b / c))
end function
public static double code(double a, double b, double c) {
	return 1.0 / ((a / b) - (b / c));
}
def code(a, b, c):
	return 1.0 / ((a / b) - (b / c))
function code(a, b, c)
	return Float64(1.0 / Float64(Float64(a / b) - Float64(b / c)))
end
function tmp = code(a, b, c)
	tmp = 1.0 / ((a / b) - (b / c));
end
code[a_, b_, c_] := N[(1.0 / N[(N[(a / b), $MachinePrecision] - N[(b / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{\frac{a}{b} - \frac{b}{c}}
\end{array}
Derivation
  1. Initial program 15.6%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Add Preprocessing
  3. Applied rewrites15.6%

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

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

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

      \[\leadsto \frac{\frac{b \cdot b}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}}{a \cdot 2} - \color{blue}{\frac{\frac{\mathsf{fma}\left(b, b, a \cdot \left(4 \cdot c\right)\right)}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}}{a \cdot 2}} \]
    4. sub-divN/A

      \[\leadsto \color{blue}{\frac{\frac{b \cdot b}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} - \frac{\mathsf{fma}\left(b, b, a \cdot \left(4 \cdot c\right)\right)}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}}{a \cdot 2}} \]
    5. clear-numN/A

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

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

      \[\leadsto \frac{1}{\color{blue}{\frac{a \cdot 2}{\frac{b \cdot b}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} - \frac{\mathsf{fma}\left(b, b, a \cdot \left(4 \cdot c\right)\right)}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}}}} \]
  5. Applied rewrites16.1%

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

    \[\leadsto \frac{1}{\color{blue}{-1 \cdot \frac{b}{c} + \frac{a}{b}}} \]
  7. Step-by-step derivation
    1. +-commutativeN/A

      \[\leadsto \frac{1}{\color{blue}{\frac{a}{b} + -1 \cdot \frac{b}{c}}} \]
    2. mul-1-negN/A

      \[\leadsto \frac{1}{\frac{a}{b} + \color{blue}{\left(\mathsf{neg}\left(\frac{b}{c}\right)\right)}} \]
    3. unsub-negN/A

      \[\leadsto \frac{1}{\color{blue}{\frac{a}{b} - \frac{b}{c}}} \]
    4. lower--.f64N/A

      \[\leadsto \frac{1}{\color{blue}{\frac{a}{b} - \frac{b}{c}}} \]
    5. lower-/.f64N/A

      \[\leadsto \frac{1}{\color{blue}{\frac{a}{b}} - \frac{b}{c}} \]
    6. lower-/.f6494.9

      \[\leadsto \frac{1}{\frac{a}{b} - \color{blue}{\frac{b}{c}}} \]
  8. Applied rewrites94.9%

    \[\leadsto \frac{1}{\color{blue}{\frac{a}{b} - \frac{b}{c}}} \]
  9. Add Preprocessing

Alternative 6: 90.4% accurate, 3.6× speedup?

\[\begin{array}{l} \\ \frac{c}{-b} \end{array} \]
(FPCore (a b c) :precision binary64 (/ c (- b)))
double code(double a, double b, double c) {
	return c / -b;
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = c / -b
end function
public static double code(double a, double b, double c) {
	return c / -b;
}
def code(a, b, c):
	return c / -b
function code(a, b, c)
	return Float64(c / Float64(-b))
end
function tmp = code(a, b, c)
	tmp = c / -b;
end
code[a_, b_, c_] := N[(c / (-b)), $MachinePrecision]
\begin{array}{l}

\\
\frac{c}{-b}
\end{array}
Derivation
  1. Initial program 15.6%

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

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

      \[\leadsto \color{blue}{\mathsf{neg}\left(\frac{c}{b}\right)} \]
    2. distribute-neg-frac2N/A

      \[\leadsto \color{blue}{\frac{c}{\mathsf{neg}\left(b\right)}} \]
    3. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{c}{\mathsf{neg}\left(b\right)}} \]
    4. lower-neg.f6491.6

      \[\leadsto \frac{c}{\color{blue}{-b}} \]
  5. Applied rewrites91.6%

    \[\leadsto \color{blue}{\frac{c}{-b}} \]
  6. Add Preprocessing

Alternative 7: 3.3% accurate, 50.0× speedup?

\[\begin{array}{l} \\ 0 \end{array} \]
(FPCore (a b c) :precision binary64 0.0)
double code(double a, double b, double c) {
	return 0.0;
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = 0.0d0
end function
public static double code(double a, double b, double c) {
	return 0.0;
}
def code(a, b, c):
	return 0.0
function code(a, b, c)
	return 0.0
end
function tmp = code(a, b, c)
	tmp = 0.0;
end
code[a_, b_, c_] := 0.0
\begin{array}{l}

\\
0
\end{array}
Derivation
  1. Initial program 15.6%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Add Preprocessing
  3. Applied rewrites15.6%

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

      \[\leadsto \color{blue}{\frac{\frac{b \cdot b}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}}{a \cdot 2} - \frac{\frac{\mathsf{fma}\left(b, b, a \cdot \left(4 \cdot c\right)\right)}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}}{a \cdot 2}} \]
    2. sub-negN/A

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

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

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

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

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

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

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{b}{a \cdot 2}, \frac{b}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}, \mathsf{neg}\left(\frac{\frac{\mathsf{fma}\left(b, b, a \cdot \left(4 \cdot c\right)\right)}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}}{a \cdot 2}\right)\right)} \]
  5. Applied rewrites16.2%

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

    \[\leadsto \color{blue}{\frac{-1}{4} \cdot \frac{b}{a} + \frac{1}{4} \cdot \frac{b}{a}} \]
  7. Step-by-step derivation
    1. distribute-rgt-outN/A

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

      \[\leadsto \frac{b}{a} \cdot \color{blue}{0} \]
    3. mul0-rgt3.3

      \[\leadsto \color{blue}{0} \]
  8. Applied rewrites3.3%

    \[\leadsto \color{blue}{0} \]
  9. Add Preprocessing

Reproduce

?
herbie shell --seed 2024226 
(FPCore (a b c)
  :name "Quadratic roots, wide range"
  :precision binary64
  :pre (and (and (and (< 4.930380657631324e-32 a) (< a 2.028240960365167e+31)) (and (< 4.930380657631324e-32 b) (< b 2.028240960365167e+31))) (and (< 4.930380657631324e-32 c) (< c 2.028240960365167e+31)))
  (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))