Quadratic roots, wide range

Percentage Accurate: 17.6% → 97.7%
Time: 11.6s
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: 17.6% 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: 97.7% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(\frac{\mathsf{fma}\left({c}^{4} \cdot -5, a \cdot a, \left(b \cdot b\right) \cdot \left(\left(c \cdot c\right) \cdot \mathsf{fma}\left(-2 \cdot c, a, \left(-b\right) \cdot b\right)\right)\right)}{{b}^{7}}, a, \frac{-c}{b}\right) \end{array} \]
(FPCore (a b c)
 :precision binary64
 (fma
  (/
   (fma
    (* (pow c 4.0) -5.0)
    (* a a)
    (* (* b b) (* (* c c) (fma (* -2.0 c) a (* (- b) b)))))
   (pow b 7.0))
  a
  (/ (- c) b)))
double code(double a, double b, double c) {
	return fma((fma((pow(c, 4.0) * -5.0), (a * a), ((b * b) * ((c * c) * fma((-2.0 * c), a, (-b * b))))) / pow(b, 7.0)), a, (-c / b));
}
function code(a, b, c)
	return fma(Float64(fma(Float64((c ^ 4.0) * -5.0), Float64(a * a), Float64(Float64(b * b) * Float64(Float64(c * c) * fma(Float64(-2.0 * c), a, Float64(Float64(-b) * b))))) / (b ^ 7.0)), a, Float64(Float64(-c) / b))
end
code[a_, b_, c_] := N[(N[(N[(N[(N[Power[c, 4.0], $MachinePrecision] * -5.0), $MachinePrecision] * N[(a * a), $MachinePrecision] + N[(N[(b * b), $MachinePrecision] * N[(N[(c * c), $MachinePrecision] * N[(N[(-2.0 * c), $MachinePrecision] * a + N[((-b) * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Power[b, 7.0], $MachinePrecision]), $MachinePrecision] * a + N[((-c) / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(\frac{\mathsf{fma}\left({c}^{4} \cdot -5, a \cdot a, \left(b \cdot b\right) \cdot \left(\left(c \cdot c\right) \cdot \mathsf{fma}\left(-2 \cdot c, a, \left(-b\right) \cdot b\right)\right)\right)}{{b}^{7}}, a, \frac{-c}{b}\right)
\end{array}
Derivation
  1. Initial program 17.8%

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

    \[\leadsto \color{blue}{-1 \cdot \frac{c}{b} + a \cdot \left(-1 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-2 \cdot \frac{{c}^{3}}{{b}^{5}} + \frac{-1}{4} \cdot \frac{a \cdot \left(4 \cdot \frac{{c}^{4}}{{b}^{6}} + 16 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right)\right)} \]
  4. Step-by-step derivation
    1. +-commutativeN/A

      \[\leadsto \color{blue}{a \cdot \left(-1 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-2 \cdot \frac{{c}^{3}}{{b}^{5}} + \frac{-1}{4} \cdot \frac{a \cdot \left(4 \cdot \frac{{c}^{4}}{{b}^{6}} + 16 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right)\right) + -1 \cdot \frac{c}{b}} \]
    2. *-commutativeN/A

      \[\leadsto \color{blue}{\left(-1 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-2 \cdot \frac{{c}^{3}}{{b}^{5}} + \frac{-1}{4} \cdot \frac{a \cdot \left(4 \cdot \frac{{c}^{4}}{{b}^{6}} + 16 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right)\right) \cdot a} + -1 \cdot \frac{c}{b} \]
    3. lower-fma.f64N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(-1 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-2 \cdot \frac{{c}^{3}}{{b}^{5}} + \frac{-1}{4} \cdot \frac{a \cdot \left(4 \cdot \frac{{c}^{4}}{{b}^{6}} + 16 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right), a, -1 \cdot \frac{c}{b}\right)} \]
  5. Applied rewrites98.9%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.25 \cdot a, \frac{{c}^{4}}{{b}^{6}} \cdot \frac{20}{b}, \frac{{c}^{3} \cdot -2}{{b}^{5}}\right), a, \left(-c\right) \cdot \frac{c}{{b}^{3}}\right), a, \frac{-c}{b}\right)} \]
  6. Taylor expanded in b around 0

    \[\leadsto \mathsf{fma}\left(\frac{-5 \cdot \left({a}^{2} \cdot {c}^{4}\right) + {b}^{2} \cdot \left(-2 \cdot \left(a \cdot {c}^{3}\right) + -1 \cdot \left({b}^{2} \cdot {c}^{2}\right)\right)}{{b}^{7}}, a, \frac{-c}{b}\right) \]
  7. Step-by-step derivation
    1. Applied rewrites98.9%

      \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(-5 \cdot {c}^{4}, a \cdot a, \mathsf{fma}\left(-2 \cdot a, {c}^{3}, \left(\left(-c\right) \cdot c\right) \cdot \left(b \cdot b\right)\right) \cdot \left(b \cdot b\right)\right)}{{b}^{7}}, a, \frac{-c}{b}\right) \]
    2. Taylor expanded in b around 0

      \[\leadsto \mathsf{fma}\left(\frac{-5 \cdot \left({a}^{2} \cdot {c}^{4}\right) + {b}^{2} \cdot \left(-2 \cdot \left(a \cdot {c}^{3}\right) + -1 \cdot \left({b}^{2} \cdot {c}^{2}\right)\right)}{{b}^{7}}, a, \frac{-c}{b}\right) \]
    3. Step-by-step derivation
      1. Applied rewrites98.9%

        \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(-5 \cdot {c}^{4}, a \cdot a, \left(\mathsf{fma}\left(-2 \cdot c, a, \left(-b\right) \cdot b\right) \cdot \left(c \cdot c\right)\right) \cdot \left(b \cdot b\right)\right)}{{b}^{7}}, a, \frac{-c}{b}\right) \]
      2. Final simplification98.9%

        \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left({c}^{4} \cdot -5, a \cdot a, \left(b \cdot b\right) \cdot \left(\left(c \cdot c\right) \cdot \mathsf{fma}\left(-2 \cdot c, a, \left(-b\right) \cdot b\right)\right)\right)}{{b}^{7}}, a, \frac{-c}{b}\right) \]
      3. Add Preprocessing

      Alternative 2: 97.0% accurate, 0.3× speedup?

      \[\begin{array}{l} \\ \mathsf{fma}\left(c, \left(\mathsf{fma}\left(\left(-a\right) \cdot b, b, \left(\left(a \cdot a\right) \cdot c\right) \cdot -2\right) \cdot {b}^{-5}\right) \cdot c, \frac{-c}{b}\right) \end{array} \]
      (FPCore (a b c)
       :precision binary64
       (fma
        c
        (* (* (fma (* (- a) b) b (* (* (* a a) c) -2.0)) (pow b -5.0)) c)
        (/ (- c) b)))
      double code(double a, double b, double c) {
      	return fma(c, ((fma((-a * b), b, (((a * a) * c) * -2.0)) * pow(b, -5.0)) * c), (-c / b));
      }
      
      function code(a, b, c)
      	return fma(c, Float64(Float64(fma(Float64(Float64(-a) * b), b, Float64(Float64(Float64(a * a) * c) * -2.0)) * (b ^ -5.0)) * c), Float64(Float64(-c) / b))
      end
      
      code[a_, b_, c_] := N[(c * N[(N[(N[(N[((-a) * b), $MachinePrecision] * b + N[(N[(N[(a * a), $MachinePrecision] * c), $MachinePrecision] * -2.0), $MachinePrecision]), $MachinePrecision] * N[Power[b, -5.0], $MachinePrecision]), $MachinePrecision] * c), $MachinePrecision] + N[((-c) / b), $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \mathsf{fma}\left(c, \left(\mathsf{fma}\left(\left(-a\right) \cdot b, b, \left(\left(a \cdot a\right) \cdot c\right) \cdot -2\right) \cdot {b}^{-5}\right) \cdot c, \frac{-c}{b}\right)
      \end{array}
      
      Derivation
      1. Initial program 17.8%

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

        \[\leadsto \color{blue}{c \cdot \left(c \cdot \left(-2 \cdot \frac{{a}^{2} \cdot c}{{b}^{5}} + -1 \cdot \frac{a}{{b}^{3}}\right) - \frac{1}{b}\right)} \]
      4. Step-by-step derivation
        1. *-commutativeN/A

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

          \[\leadsto \color{blue}{\left(c \cdot \left(-2 \cdot \frac{{a}^{2} \cdot c}{{b}^{5}} + -1 \cdot \frac{a}{{b}^{3}}\right) - \frac{1}{b}\right) \cdot c} \]
      5. Applied rewrites97.8%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\left(-2 \cdot a\right) \cdot a, \frac{c}{{b}^{5}}, \frac{-a}{{b}^{3}}\right), c, \frac{-1}{b}\right) \cdot c} \]
      6. Taylor expanded in b around 0

        \[\leadsto \mathsf{fma}\left(\frac{-2 \cdot \left({a}^{2} \cdot c\right) + -1 \cdot \left(a \cdot {b}^{2}\right)}{{b}^{5}}, c, \frac{-1}{b}\right) \cdot c \]
      7. Step-by-step derivation
        1. Applied rewrites97.8%

          \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(\left(-a\right) \cdot b, b, \left(\left(a \cdot a\right) \cdot c\right) \cdot -2\right)}{{b}^{5}}, c, \frac{-1}{b}\right) \cdot c \]
        2. Step-by-step derivation
          1. Applied rewrites98.2%

            \[\leadsto \mathsf{fma}\left(c, \color{blue}{\left({b}^{-5} \cdot \mathsf{fma}\left(\left(-a\right) \cdot b, b, \left(\left(a \cdot a\right) \cdot c\right) \cdot -2\right)\right) \cdot c}, \frac{-c}{b}\right) \]
          2. Final simplification98.2%

            \[\leadsto \mathsf{fma}\left(c, \left(\mathsf{fma}\left(\left(-a\right) \cdot b, b, \left(\left(a \cdot a\right) \cdot c\right) \cdot -2\right) \cdot {b}^{-5}\right) \cdot c, \frac{-c}{b}\right) \]
          3. Add Preprocessing

          Alternative 3: 96.6% accurate, 0.3× speedup?

          \[\begin{array}{l} \\ \mathsf{fma}\left(\mathsf{fma}\left(\left(-a\right) \cdot b, b, \left(\left(a \cdot a\right) \cdot c\right) \cdot -2\right) \cdot {b}^{-5}, c, \frac{-1}{b}\right) \cdot c \end{array} \]
          (FPCore (a b c)
           :precision binary64
           (*
            (fma
             (* (fma (* (- a) b) b (* (* (* a a) c) -2.0)) (pow b -5.0))
             c
             (/ -1.0 b))
            c))
          double code(double a, double b, double c) {
          	return fma((fma((-a * b), b, (((a * a) * c) * -2.0)) * pow(b, -5.0)), c, (-1.0 / b)) * c;
          }
          
          function code(a, b, c)
          	return Float64(fma(Float64(fma(Float64(Float64(-a) * b), b, Float64(Float64(Float64(a * a) * c) * -2.0)) * (b ^ -5.0)), c, Float64(-1.0 / b)) * c)
          end
          
          code[a_, b_, c_] := N[(N[(N[(N[(N[((-a) * b), $MachinePrecision] * b + N[(N[(N[(a * a), $MachinePrecision] * c), $MachinePrecision] * -2.0), $MachinePrecision]), $MachinePrecision] * N[Power[b, -5.0], $MachinePrecision]), $MachinePrecision] * c + N[(-1.0 / b), $MachinePrecision]), $MachinePrecision] * c), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \mathsf{fma}\left(\mathsf{fma}\left(\left(-a\right) \cdot b, b, \left(\left(a \cdot a\right) \cdot c\right) \cdot -2\right) \cdot {b}^{-5}, c, \frac{-1}{b}\right) \cdot c
          \end{array}
          
          Derivation
          1. Initial program 17.8%

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

            \[\leadsto \color{blue}{c \cdot \left(c \cdot \left(-2 \cdot \frac{{a}^{2} \cdot c}{{b}^{5}} + -1 \cdot \frac{a}{{b}^{3}}\right) - \frac{1}{b}\right)} \]
          4. Step-by-step derivation
            1. *-commutativeN/A

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

              \[\leadsto \color{blue}{\left(c \cdot \left(-2 \cdot \frac{{a}^{2} \cdot c}{{b}^{5}} + -1 \cdot \frac{a}{{b}^{3}}\right) - \frac{1}{b}\right) \cdot c} \]
          5. Applied rewrites97.8%

            \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\left(-2 \cdot a\right) \cdot a, \frac{c}{{b}^{5}}, \frac{-a}{{b}^{3}}\right), c, \frac{-1}{b}\right) \cdot c} \]
          6. Taylor expanded in b around 0

            \[\leadsto \mathsf{fma}\left(\frac{-2 \cdot \left({a}^{2} \cdot c\right) + -1 \cdot \left(a \cdot {b}^{2}\right)}{{b}^{5}}, c, \frac{-1}{b}\right) \cdot c \]
          7. Step-by-step derivation
            1. Applied rewrites97.8%

              \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(\left(-a\right) \cdot b, b, \left(\left(a \cdot a\right) \cdot c\right) \cdot -2\right)}{{b}^{5}}, c, \frac{-1}{b}\right) \cdot c \]
            2. Step-by-step derivation
              1. Applied rewrites97.8%

                \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\left(-a\right) \cdot b, b, \left(\left(a \cdot a\right) \cdot c\right) \cdot -2\right) \cdot {b}^{-5}, c, \frac{-1}{b}\right) \cdot c \]
              2. Add Preprocessing

              Alternative 4: 95.4% accurate, 0.4× speedup?

              \[\begin{array}{l} \\ -\mathsf{fma}\left(a, \frac{c \cdot c}{{b}^{3}}, \frac{c}{b}\right) \end{array} \]
              (FPCore (a b c)
               :precision binary64
               (- (fma a (/ (* c c) (pow b 3.0)) (/ c b))))
              double code(double a, double b, double c) {
              	return -fma(a, ((c * c) / pow(b, 3.0)), (c / b));
              }
              
              function code(a, b, c)
              	return Float64(-fma(a, Float64(Float64(c * c) / (b ^ 3.0)), Float64(c / b)))
              end
              
              code[a_, b_, c_] := (-N[(a * N[(N[(c * c), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision] + N[(c / b), $MachinePrecision]), $MachinePrecision])
              
              \begin{array}{l}
              
              \\
              -\mathsf{fma}\left(a, \frac{c \cdot c}{{b}^{3}}, \frac{c}{b}\right)
              \end{array}
              
              Derivation
              1. Initial program 17.8%

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

                \[\leadsto \color{blue}{-1 \cdot \frac{c}{b} + a \cdot \left(-1 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-2 \cdot \frac{{c}^{3}}{{b}^{5}} + \frac{-1}{4} \cdot \frac{a \cdot \left(4 \cdot \frac{{c}^{4}}{{b}^{6}} + 16 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right)\right)} \]
              4. Step-by-step derivation
                1. +-commutativeN/A

                  \[\leadsto \color{blue}{a \cdot \left(-1 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-2 \cdot \frac{{c}^{3}}{{b}^{5}} + \frac{-1}{4} \cdot \frac{a \cdot \left(4 \cdot \frac{{c}^{4}}{{b}^{6}} + 16 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right)\right) + -1 \cdot \frac{c}{b}} \]
                2. *-commutativeN/A

                  \[\leadsto \color{blue}{\left(-1 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-2 \cdot \frac{{c}^{3}}{{b}^{5}} + \frac{-1}{4} \cdot \frac{a \cdot \left(4 \cdot \frac{{c}^{4}}{{b}^{6}} + 16 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right)\right) \cdot a} + -1 \cdot \frac{c}{b} \]
                3. lower-fma.f64N/A

                  \[\leadsto \color{blue}{\mathsf{fma}\left(-1 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-2 \cdot \frac{{c}^{3}}{{b}^{5}} + \frac{-1}{4} \cdot \frac{a \cdot \left(4 \cdot \frac{{c}^{4}}{{b}^{6}} + 16 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right), a, -1 \cdot \frac{c}{b}\right)} \]
              5. Applied rewrites98.9%

                \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.25 \cdot a, \frac{{c}^{4}}{{b}^{6}} \cdot \frac{20}{b}, \frac{{c}^{3} \cdot -2}{{b}^{5}}\right), a, \left(-c\right) \cdot \frac{c}{{b}^{3}}\right), a, \frac{-c}{b}\right)} \]
              6. Taylor expanded in b around 0

                \[\leadsto \mathsf{fma}\left(\frac{-5 \cdot \left({a}^{2} \cdot {c}^{4}\right) + {b}^{2} \cdot \left(-2 \cdot \left(a \cdot {c}^{3}\right) + -1 \cdot \left({b}^{2} \cdot {c}^{2}\right)\right)}{{b}^{7}}, a, \frac{-c}{b}\right) \]
              7. Step-by-step derivation
                1. Applied rewrites98.9%

                  \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(-5 \cdot {c}^{4}, a \cdot a, \mathsf{fma}\left(-2 \cdot a, {c}^{3}, \left(\left(-c\right) \cdot c\right) \cdot \left(b \cdot b\right)\right) \cdot \left(b \cdot b\right)\right)}{{b}^{7}}, a, \frac{-c}{b}\right) \]
                2. Taylor expanded in a around 0

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

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

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

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

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

                    \[\leadsto \color{blue}{-\left(\frac{a \cdot {c}^{2}}{{b}^{3}} + \frac{c}{b}\right)} \]
                  6. associate-/l*N/A

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

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

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

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

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

                    \[\leadsto -\mathsf{fma}\left(a, \frac{c \cdot c}{\color{blue}{{b}^{3}}}, \frac{c}{b}\right) \]
                  12. lower-/.f6496.8

                    \[\leadsto -\mathsf{fma}\left(a, \frac{c \cdot c}{{b}^{3}}, \color{blue}{\frac{c}{b}}\right) \]
                4. Applied rewrites96.8%

                  \[\leadsto \color{blue}{-\mathsf{fma}\left(a, \frac{c \cdot c}{{b}^{3}}, \frac{c}{b}\right)} \]
                5. Add Preprocessing

                Alternative 5: 95.4% accurate, 1.2× speedup?

                \[\begin{array}{l} \\ \frac{\mathsf{fma}\left(c, \frac{c \cdot a}{b \cdot b}, c\right)}{-b} \end{array} \]
                (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(c, Float64(Float64(c * a) / Float64(b * b)), c) / Float64(-b))
                end
                
                code[a_, b_, c_] := N[(N[(c * N[(N[(c * a), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + c), $MachinePrecision] / (-b)), $MachinePrecision]
                
                \begin{array}{l}
                
                \\
                \frac{\mathsf{fma}\left(c, \frac{c \cdot a}{b \cdot b}, c\right)}{-b}
                \end{array}
                
                Derivation
                1. Initial program 17.8%

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

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

                    \[\leadsto -\color{blue}{\frac{c + \frac{a \cdot {c}^{2}}{{b}^{2}}}{b}} \]
                  6. +-commutativeN/A

                    \[\leadsto -\frac{\color{blue}{\frac{a \cdot {c}^{2}}{{b}^{2}} + c}}{b} \]
                  7. *-commutativeN/A

                    \[\leadsto -\frac{\frac{\color{blue}{{c}^{2} \cdot a}}{{b}^{2}} + c}{b} \]
                  8. unpow2N/A

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

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

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

                    \[\leadsto -\frac{\frac{c \cdot \left(a \cdot c\right)}{\color{blue}{b \cdot b}} + c}{b} \]
                  12. times-fracN/A

                    \[\leadsto -\frac{\color{blue}{\frac{c}{b} \cdot \frac{a \cdot c}{b}} + c}{b} \]
                  13. lower-fma.f64N/A

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

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

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

                    \[\leadsto -\frac{\mathsf{fma}\left(\frac{c}{b}, \frac{\color{blue}{c \cdot a}}{b}, c\right)}{b} \]
                  17. lower-*.f6496.8

                    \[\leadsto -\frac{\mathsf{fma}\left(\frac{c}{b}, \frac{\color{blue}{c \cdot a}}{b}, c\right)}{b} \]
                5. Applied rewrites96.8%

                  \[\leadsto \color{blue}{-\frac{\mathsf{fma}\left(\frac{c}{b}, \frac{c \cdot a}{b}, c\right)}{b}} \]
                6. Step-by-step derivation
                  1. Applied rewrites96.8%

                    \[\leadsto -\frac{\mathsf{fma}\left(c, \frac{a \cdot c}{b \cdot b}, c\right)}{b} \]
                  2. Final simplification96.8%

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

                  Alternative 6: 90.5% 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(Float64(-c) / 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 17.8%

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

                    \[\leadsto \color{blue}{-1 \cdot \frac{c}{b}} \]
                  4. Step-by-step derivation
                    1. associate-*r/N/A

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

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

                      \[\leadsto \frac{\color{blue}{\mathsf{neg}\left(c\right)}}{b} \]
                    4. lower-neg.f6491.1

                      \[\leadsto \frac{\color{blue}{-c}}{b} \]
                  5. Applied rewrites91.1%

                    \[\leadsto \color{blue}{\frac{-c}{b}} \]
                  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 17.8%

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

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

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

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

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

                      \[\leadsto \frac{\color{blue}{\sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c} - b}}{2 \cdot a} \]
                    6. div-subN/A

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

                      \[\leadsto \color{blue}{\frac{\sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} - \frac{b}{2 \cdot a}} \]
                  4. Applied rewrites17.3%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                      \[\leadsto \mathsf{fma}\left(\frac{\frac{1}{2}}{a}, \sqrt{\mathsf{fma}\left(c \cdot a, -4, b \cdot b\right)}, \mathsf{neg}\left(\color{blue}{\frac{b}{2 \cdot a}}\right)\right) \]
                  6. Applied rewrites18.8%

                    \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{0.5}{a}, \sqrt{\mathsf{fma}\left(c \cdot a, -4, b \cdot b\right)}, \frac{b}{a \cdot -2}\right)} \]
                  7. Taylor expanded in c around 0

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

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

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

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

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

                  Reproduce

                  ?
                  herbie shell --seed 2024276 
                  (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)))