| Alternative 1 | |
|---|---|
| Accuracy | 99.2% |
| Cost | 14400 |

(FPCore (a b c) :precision binary64 (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))
(FPCore (a b c) :precision binary64 (* (/ (+ (* 0.0 (* b b)) (* (* c a) -4.0)) (+ b (sqrt (fma c (* a -4.0) (* b b))))) (/ 0.5 a)))
double code(double a, double b, double c) {
return (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
}
double code(double a, double b, double c) {
return (((0.0 * (b * b)) + ((c * a) * -4.0)) / (b + sqrt(fma(c, (a * -4.0), (b * b))))) * (0.5 / 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 code(a, b, c) return Float64(Float64(Float64(Float64(0.0 * Float64(b * b)) + Float64(Float64(c * a) * -4.0)) / Float64(b + sqrt(fma(c, Float64(a * -4.0), Float64(b * b))))) * Float64(0.5 / 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]
code[a_, b_, c_] := N[(N[(N[(N[(0.0 * N[(b * b), $MachinePrecision]), $MachinePrecision] + N[(N[(c * a), $MachinePrecision] * -4.0), $MachinePrecision]), $MachinePrecision] / N[(b + N[Sqrt[N[(c * N[(a * -4.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(0.5 / a), $MachinePrecision]), $MachinePrecision]
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a}
\frac{0 \cdot \left(b \cdot b\right) + \left(c \cdot a\right) \cdot -4}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} \cdot \frac{0.5}{a}
Herbie found 6 alternatives:
| Alternative | Accuracy | Speedup |
|---|
Initial program 30.6%
Simplified30.6%
[Start]30.6% | \[ \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a}
\] |
|---|---|
/-rgt-identity [<=]30.6% | \[ \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{\frac{2 \cdot a}{1}}}
\] |
metadata-eval [<=]30.6% | \[ \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\frac{2 \cdot a}{\color{blue}{--1}}}
\] |
associate-/l* [<=]30.6% | \[ \color{blue}{\frac{\left(\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}\right) \cdot \left(--1\right)}{2 \cdot a}}
\] |
associate-*r/ [<=]30.6% | \[ \color{blue}{\left(\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}\right) \cdot \frac{--1}{2 \cdot a}}
\] |
+-commutative [=>]30.6% | \[ \color{blue}{\left(\sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c} + \left(-b\right)\right)} \cdot \frac{--1}{2 \cdot a}
\] |
unsub-neg [=>]30.6% | \[ \color{blue}{\left(\sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c} - b\right)} \cdot \frac{--1}{2 \cdot a}
\] |
fma-neg [=>]30.6% | \[ \left(\sqrt{\color{blue}{\mathsf{fma}\left(b, b, -\left(4 \cdot a\right) \cdot c\right)}} - b\right) \cdot \frac{--1}{2 \cdot a}
\] |
associate-*l* [=>]30.6% | \[ \left(\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{4 \cdot \left(a \cdot c\right)}\right)} - b\right) \cdot \frac{--1}{2 \cdot a}
\] |
*-commutative [=>]30.6% | \[ \left(\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(a \cdot c\right) \cdot 4}\right)} - b\right) \cdot \frac{--1}{2 \cdot a}
\] |
distribute-rgt-neg-in [=>]30.6% | \[ \left(\sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(a \cdot c\right) \cdot \left(-4\right)}\right)} - b\right) \cdot \frac{--1}{2 \cdot a}
\] |
metadata-eval [=>]30.6% | \[ \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot \color{blue}{-4}\right)} - b\right) \cdot \frac{--1}{2 \cdot a}
\] |
associate-/r* [=>]30.6% | \[ \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \color{blue}{\frac{\frac{--1}{2}}{a}}
\] |
metadata-eval [=>]30.6% | \[ \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \frac{\frac{\color{blue}{1}}{2}}{a}
\] |
metadata-eval [=>]30.6% | \[ \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \frac{\color{blue}{0.5}}{a}
\] |
Applied egg-rr30.7%
[Start]30.6% | \[ \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \frac{0.5}{a}
\] |
|---|---|
fma-udef [=>]30.6% | \[ \left(\sqrt{\color{blue}{b \cdot b + \left(a \cdot c\right) \cdot -4}} - b\right) \cdot \frac{0.5}{a}
\] |
*-commutative [=>]30.6% | \[ \left(\sqrt{b \cdot b + \color{blue}{-4 \cdot \left(a \cdot c\right)}} - b\right) \cdot \frac{0.5}{a}
\] |
metadata-eval [<=]30.6% | \[ \left(\sqrt{b \cdot b + \color{blue}{\left(-4\right)} \cdot \left(a \cdot c\right)} - b\right) \cdot \frac{0.5}{a}
\] |
cancel-sign-sub-inv [<=]30.6% | \[ \left(\sqrt{\color{blue}{b \cdot b - 4 \cdot \left(a \cdot c\right)}} - b\right) \cdot \frac{0.5}{a}
\] |
associate-*l* [<=]30.6% | \[ \left(\sqrt{b \cdot b - \color{blue}{\left(4 \cdot a\right) \cdot c}} - b\right) \cdot \frac{0.5}{a}
\] |
*-un-lft-identity [=>]30.6% | \[ \left(\sqrt{b \cdot b - \color{blue}{1 \cdot \left(\left(4 \cdot a\right) \cdot c\right)}} - b\right) \cdot \frac{0.5}{a}
\] |
prod-diff [=>]30.6% | \[ \left(\sqrt{\color{blue}{\mathsf{fma}\left(b, b, -\left(\left(4 \cdot a\right) \cdot c\right) \cdot 1\right) + \mathsf{fma}\left(-\left(4 \cdot a\right) \cdot c, 1, \left(\left(4 \cdot a\right) \cdot c\right) \cdot 1\right)}} - b\right) \cdot \frac{0.5}{a}
\] |
Simplified30.5%
[Start]30.7% | \[ \left(\sqrt{\mathsf{fma}\left(b, b, -\left(a \cdot \left(c \cdot -4\right)\right) \cdot 1\right) + \mathsf{fma}\left(a \cdot \left(c \cdot -4\right), 1, \left(a \cdot \left(c \cdot -4\right)\right) \cdot 1\right)} - b\right) \cdot \frac{0.5}{a}
\] |
|---|---|
+-commutative [=>]30.7% | \[ \left(\sqrt{\color{blue}{\mathsf{fma}\left(a \cdot \left(c \cdot -4\right), 1, \left(a \cdot \left(c \cdot -4\right)\right) \cdot 1\right) + \mathsf{fma}\left(b, b, -\left(a \cdot \left(c \cdot -4\right)\right) \cdot 1\right)}} - b\right) \cdot \frac{0.5}{a}
\] |
fma-udef [=>]30.7% | \[ \left(\sqrt{\color{blue}{\left(\left(a \cdot \left(c \cdot -4\right)\right) \cdot 1 + \left(a \cdot \left(c \cdot -4\right)\right) \cdot 1\right)} + \mathsf{fma}\left(b, b, -\left(a \cdot \left(c \cdot -4\right)\right) \cdot 1\right)} - b\right) \cdot \frac{0.5}{a}
\] |
*-rgt-identity [=>]30.7% | \[ \left(\sqrt{\left(\color{blue}{a \cdot \left(c \cdot -4\right)} + \left(a \cdot \left(c \cdot -4\right)\right) \cdot 1\right) + \mathsf{fma}\left(b, b, -\left(a \cdot \left(c \cdot -4\right)\right) \cdot 1\right)} - b\right) \cdot \frac{0.5}{a}
\] |
*-rgt-identity [=>]30.7% | \[ \left(\sqrt{\left(a \cdot \left(c \cdot -4\right) + \color{blue}{a \cdot \left(c \cdot -4\right)}\right) + \mathsf{fma}\left(b, b, -\left(a \cdot \left(c \cdot -4\right)\right) \cdot 1\right)} - b\right) \cdot \frac{0.5}{a}
\] |
count-2 [=>]30.7% | \[ \left(\sqrt{\color{blue}{2 \cdot \left(a \cdot \left(c \cdot -4\right)\right)} + \mathsf{fma}\left(b, b, -\left(a \cdot \left(c \cdot -4\right)\right) \cdot 1\right)} - b\right) \cdot \frac{0.5}{a}
\] |
*-commutative [=>]30.7% | \[ \left(\sqrt{2 \cdot \color{blue}{\left(\left(c \cdot -4\right) \cdot a\right)} + \mathsf{fma}\left(b, b, -\left(a \cdot \left(c \cdot -4\right)\right) \cdot 1\right)} - b\right) \cdot \frac{0.5}{a}
\] |
*-commutative [=>]30.7% | \[ \left(\sqrt{2 \cdot \left(\color{blue}{\left(-4 \cdot c\right)} \cdot a\right) + \mathsf{fma}\left(b, b, -\left(a \cdot \left(c \cdot -4\right)\right) \cdot 1\right)} - b\right) \cdot \frac{0.5}{a}
\] |
associate-*r* [<=]30.7% | \[ \left(\sqrt{2 \cdot \color{blue}{\left(-4 \cdot \left(c \cdot a\right)\right)} + \mathsf{fma}\left(b, b, -\left(a \cdot \left(c \cdot -4\right)\right) \cdot 1\right)} - b\right) \cdot \frac{0.5}{a}
\] |
*-rgt-identity [=>]30.7% | \[ \left(\sqrt{2 \cdot \left(-4 \cdot \left(c \cdot a\right)\right) + \mathsf{fma}\left(b, b, -\color{blue}{a \cdot \left(c \cdot -4\right)}\right)} - b\right) \cdot \frac{0.5}{a}
\] |
fma-neg [<=]30.5% | \[ \left(\sqrt{2 \cdot \left(-4 \cdot \left(c \cdot a\right)\right) + \color{blue}{\left(b \cdot b - a \cdot \left(c \cdot -4\right)\right)}} - b\right) \cdot \frac{0.5}{a}
\] |
*-commutative [=>]30.5% | \[ \left(\sqrt{2 \cdot \left(-4 \cdot \left(c \cdot a\right)\right) + \left(b \cdot b - \color{blue}{\left(c \cdot -4\right) \cdot a}\right)} - b\right) \cdot \frac{0.5}{a}
\] |
*-commutative [=>]30.5% | \[ \left(\sqrt{2 \cdot \left(-4 \cdot \left(c \cdot a\right)\right) + \left(b \cdot b - \color{blue}{\left(-4 \cdot c\right)} \cdot a\right)} - b\right) \cdot \frac{0.5}{a}
\] |
associate-*r* [<=]30.5% | \[ \left(\sqrt{2 \cdot \left(-4 \cdot \left(c \cdot a\right)\right) + \left(b \cdot b - \color{blue}{-4 \cdot \left(c \cdot a\right)}\right)} - b\right) \cdot \frac{0.5}{a}
\] |
Applied egg-rr31.3%
[Start]30.5% | \[ \left(\sqrt{2 \cdot \left(-4 \cdot \left(c \cdot a\right)\right) + \left(b \cdot b - -4 \cdot \left(c \cdot a\right)\right)} - b\right) \cdot \frac{0.5}{a}
\] |
|---|---|
flip-- [=>]30.3% | \[ \color{blue}{\frac{\sqrt{2 \cdot \left(-4 \cdot \left(c \cdot a\right)\right) + \left(b \cdot b - -4 \cdot \left(c \cdot a\right)\right)} \cdot \sqrt{2 \cdot \left(-4 \cdot \left(c \cdot a\right)\right) + \left(b \cdot b - -4 \cdot \left(c \cdot a\right)\right)} - b \cdot b}{\sqrt{2 \cdot \left(-4 \cdot \left(c \cdot a\right)\right) + \left(b \cdot b - -4 \cdot \left(c \cdot a\right)\right)} + b}} \cdot \frac{0.5}{a}
\] |
add-sqr-sqrt [<=]31.3% | \[ \frac{\color{blue}{\left(2 \cdot \left(-4 \cdot \left(c \cdot a\right)\right) + \left(b \cdot b - -4 \cdot \left(c \cdot a\right)\right)\right)} - b \cdot b}{\sqrt{2 \cdot \left(-4 \cdot \left(c \cdot a\right)\right) + \left(b \cdot b - -4 \cdot \left(c \cdot a\right)\right)} + b} \cdot \frac{0.5}{a}
\] |
associate-*r* [=>]31.3% | \[ \frac{\left(\color{blue}{\left(2 \cdot -4\right) \cdot \left(c \cdot a\right)} + \left(b \cdot b - -4 \cdot \left(c \cdot a\right)\right)\right) - b \cdot b}{\sqrt{2 \cdot \left(-4 \cdot \left(c \cdot a\right)\right) + \left(b \cdot b - -4 \cdot \left(c \cdot a\right)\right)} + b} \cdot \frac{0.5}{a}
\] |
metadata-eval [=>]31.3% | \[ \frac{\left(\color{blue}{-8} \cdot \left(c \cdot a\right) + \left(b \cdot b - -4 \cdot \left(c \cdot a\right)\right)\right) - b \cdot b}{\sqrt{2 \cdot \left(-4 \cdot \left(c \cdot a\right)\right) + \left(b \cdot b - -4 \cdot \left(c \cdot a\right)\right)} + b} \cdot \frac{0.5}{a}
\] |
cancel-sign-sub-inv [=>]31.3% | \[ \frac{\left(-8 \cdot \left(c \cdot a\right) + \color{blue}{\left(b \cdot b + \left(--4\right) \cdot \left(c \cdot a\right)\right)}\right) - b \cdot b}{\sqrt{2 \cdot \left(-4 \cdot \left(c \cdot a\right)\right) + \left(b \cdot b - -4 \cdot \left(c \cdot a\right)\right)} + b} \cdot \frac{0.5}{a}
\] |
metadata-eval [=>]31.3% | \[ \frac{\left(-8 \cdot \left(c \cdot a\right) + \left(b \cdot b + \color{blue}{4} \cdot \left(c \cdot a\right)\right)\right) - b \cdot b}{\sqrt{2 \cdot \left(-4 \cdot \left(c \cdot a\right)\right) + \left(b \cdot b - -4 \cdot \left(c \cdot a\right)\right)} + b} \cdot \frac{0.5}{a}
\] |
Simplified31.5%
[Start]31.3% | \[ \frac{\left(-8 \cdot \left(c \cdot a\right) + \left(b \cdot b + 4 \cdot \left(c \cdot a\right)\right)\right) - b \cdot b}{\sqrt{-8 \cdot \left(c \cdot a\right) + \left(b \cdot b + 4 \cdot \left(c \cdot a\right)\right)} + b} \cdot \frac{0.5}{a}
\] |
|---|
Applied egg-rr31.5%
[Start]31.5% | \[ \frac{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right) - b \cdot b}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} \cdot \frac{0.5}{a}
\] |
|---|---|
sub-neg [=>]31.5% | \[ \frac{\color{blue}{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right) + \left(-b \cdot b\right)}}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} \cdot \frac{0.5}{a}
\] |
*-commutative [=>]31.5% | \[ \frac{\mathsf{fma}\left(c, \color{blue}{-4 \cdot a}, b \cdot b\right) + \left(-b \cdot b\right)}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} \cdot \frac{0.5}{a}
\] |
Simplified99.3%
[Start]31.5% | \[ \frac{\mathsf{fma}\left(c, -4 \cdot a, b \cdot b\right) + \left(-b \cdot b\right)}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} \cdot \frac{0.5}{a}
\] |
|---|---|
+-commutative [=>]31.5% | \[ \frac{\color{blue}{\left(-b \cdot b\right) + \mathsf{fma}\left(c, -4 \cdot a, b \cdot b\right)}}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} \cdot \frac{0.5}{a}
\] |
fma-def [<=]31.5% | \[ \frac{\left(-b \cdot b\right) + \color{blue}{\left(c \cdot \left(-4 \cdot a\right) + b \cdot b\right)}}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} \cdot \frac{0.5}{a}
\] |
+-commutative [=>]31.5% | \[ \frac{\left(-b \cdot b\right) + \color{blue}{\left(b \cdot b + c \cdot \left(-4 \cdot a\right)\right)}}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} \cdot \frac{0.5}{a}
\] |
associate-+r+ [=>]99.3% | \[ \frac{\color{blue}{\left(\left(-b \cdot b\right) + b \cdot b\right) + c \cdot \left(-4 \cdot a\right)}}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} \cdot \frac{0.5}{a}
\] |
neg-mul-1 [=>]99.3% | \[ \frac{\left(\color{blue}{-1 \cdot \left(b \cdot b\right)} + b \cdot b\right) + c \cdot \left(-4 \cdot a\right)}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} \cdot \frac{0.5}{a}
\] |
distribute-lft1-in [=>]99.3% | \[ \frac{\color{blue}{\left(-1 + 1\right) \cdot \left(b \cdot b\right)} + c \cdot \left(-4 \cdot a\right)}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} \cdot \frac{0.5}{a}
\] |
metadata-eval [=>]99.3% | \[ \frac{\color{blue}{0} \cdot \left(b \cdot b\right) + c \cdot \left(-4 \cdot a\right)}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} \cdot \frac{0.5}{a}
\] |
associate-*r* [=>]99.3% | \[ \frac{0 \cdot \left(b \cdot b\right) + \color{blue}{\left(c \cdot -4\right) \cdot a}}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} \cdot \frac{0.5}{a}
\] |
rem-square-sqrt [<=]0.0% | \[ \frac{0 \cdot \left(b \cdot b\right) + \left(c \cdot \color{blue}{\left(\sqrt{-4} \cdot \sqrt{-4}\right)}\right) \cdot a}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} \cdot \frac{0.5}{a}
\] |
unpow2 [<=]0.0% | \[ \frac{0 \cdot \left(b \cdot b\right) + \left(c \cdot \color{blue}{{\left(\sqrt{-4}\right)}^{2}}\right) \cdot a}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} \cdot \frac{0.5}{a}
\] |
*-commutative [=>]0.0% | \[ \frac{0 \cdot \left(b \cdot b\right) + \color{blue}{\left({\left(\sqrt{-4}\right)}^{2} \cdot c\right)} \cdot a}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} \cdot \frac{0.5}{a}
\] |
unpow2 [=>]0.0% | \[ \frac{0 \cdot \left(b \cdot b\right) + \left(\color{blue}{\left(\sqrt{-4} \cdot \sqrt{-4}\right)} \cdot c\right) \cdot a}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} \cdot \frac{0.5}{a}
\] |
rem-square-sqrt [=>]99.3% | \[ \frac{0 \cdot \left(b \cdot b\right) + \left(\color{blue}{-4} \cdot c\right) \cdot a}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} \cdot \frac{0.5}{a}
\] |
associate-*r* [<=]99.3% | \[ \frac{0 \cdot \left(b \cdot b\right) + \color{blue}{-4 \cdot \left(c \cdot a\right)}}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} \cdot \frac{0.5}{a}
\] |
*-commutative [=>]99.3% | \[ \frac{0 \cdot \left(b \cdot b\right) + \color{blue}{\left(c \cdot a\right) \cdot -4}}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}} \cdot \frac{0.5}{a}
\] |
Final simplification99.3%
| Alternative 1 | |
|---|---|
| Accuracy | 99.2% |
| Cost | 14400 |
| Alternative 2 | |
|---|---|
| Accuracy | 90.9% |
| Cost | 16452 |
| Alternative 3 | |
|---|---|
| Accuracy | 90.8% |
| Cost | 14788 |
| Alternative 4 | |
|---|---|
| Accuracy | 90.7% |
| Cost | 7232 |
| Alternative 5 | |
|---|---|
| Accuracy | 90.7% |
| Cost | 1344 |
| Alternative 6 | |
|---|---|
| Accuracy | 81.0% |
| Cost | 256 |
herbie shell --seed 2023165
(FPCore (a b c)
:name "Quadratic roots, medium range"
:precision binary64
:pre (and (and (and (< 1.1102230246251565e-16 a) (< a 9007199254740992.0)) (and (< 1.1102230246251565e-16 b) (< b 9007199254740992.0))) (and (< 1.1102230246251565e-16 c) (< c 9007199254740992.0)))
(/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))