| Alternative 1 | |
|---|---|
| Accuracy | 88.7% |
| Cost | 38052 |

(FPCore (a b c) :precision binary64 (if (>= b 0.0) (/ (* 2.0 c) (- (- b) (sqrt (- (* b b) (* (* 4.0 a) c))))) (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a))))
(FPCore (a b c)
:precision binary64
(let* ((t_0 (/ (* 2.0 c) (- (- b) b)))
(t_1 (sqrt (fma b b (* c (* a -4.0)))))
(t_2 (- (/ c b) (/ b a)))
(t_3 (sqrt (- (* b b) (* c (* 4.0 a)))))
(t_4
(if (>= b 0.0) (/ (* 2.0 c) (- (- b) t_3)) (/ (- t_3 b) (* 2.0 a)))))
(if (<= t_4 (- INFINITY))
(if (>= b 0.0) (/ b a) t_2)
(if (<= t_4 -2e-210)
(if (>= b 0.0) (/ 2.0 (/ (- (- b) t_1) c)) (/ (- t_1 b) (* 2.0 a)))
(if (<= t_4 1e-216)
(if (>= b 0.0) t_0 (/ (- (- (/ 2.0 (/ b (* c a))) b) b) (* 2.0 a)))
(if (<= t_4 1e+237) t_4 (if (>= b 0.0) t_0 t_2)))))))double code(double a, double b, double c) {
double tmp;
if (b >= 0.0) {
tmp = (2.0 * c) / (-b - sqrt(((b * b) - ((4.0 * a) * c))));
} else {
tmp = (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
}
return tmp;
}
double code(double a, double b, double c) {
double t_0 = (2.0 * c) / (-b - b);
double t_1 = sqrt(fma(b, b, (c * (a * -4.0))));
double t_2 = (c / b) - (b / a);
double t_3 = sqrt(((b * b) - (c * (4.0 * a))));
double tmp;
if (b >= 0.0) {
tmp = (2.0 * c) / (-b - t_3);
} else {
tmp = (t_3 - b) / (2.0 * a);
}
double t_4 = tmp;
double tmp_2;
if (t_4 <= -((double) INFINITY)) {
double tmp_3;
if (b >= 0.0) {
tmp_3 = b / a;
} else {
tmp_3 = t_2;
}
tmp_2 = tmp_3;
} else if (t_4 <= -2e-210) {
double tmp_4;
if (b >= 0.0) {
tmp_4 = 2.0 / ((-b - t_1) / c);
} else {
tmp_4 = (t_1 - b) / (2.0 * a);
}
tmp_2 = tmp_4;
} else if (t_4 <= 1e-216) {
double tmp_5;
if (b >= 0.0) {
tmp_5 = t_0;
} else {
tmp_5 = (((2.0 / (b / (c * a))) - b) - b) / (2.0 * a);
}
tmp_2 = tmp_5;
} else if (t_4 <= 1e+237) {
tmp_2 = t_4;
} else if (b >= 0.0) {
tmp_2 = t_0;
} else {
tmp_2 = t_2;
}
return tmp_2;
}
function code(a, b, c) tmp = 0.0 if (b >= 0.0) tmp = Float64(Float64(2.0 * c) / Float64(Float64(-b) - sqrt(Float64(Float64(b * b) - Float64(Float64(4.0 * a) * c))))); else tmp = Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(4.0 * a) * c)))) / Float64(2.0 * a)); end return tmp end
function code(a, b, c) t_0 = Float64(Float64(2.0 * c) / Float64(Float64(-b) - b)) t_1 = sqrt(fma(b, b, Float64(c * Float64(a * -4.0)))) t_2 = Float64(Float64(c / b) - Float64(b / a)) t_3 = sqrt(Float64(Float64(b * b) - Float64(c * Float64(4.0 * a)))) tmp = 0.0 if (b >= 0.0) tmp = Float64(Float64(2.0 * c) / Float64(Float64(-b) - t_3)); else tmp = Float64(Float64(t_3 - b) / Float64(2.0 * a)); end t_4 = tmp tmp_2 = 0.0 if (t_4 <= Float64(-Inf)) tmp_3 = 0.0 if (b >= 0.0) tmp_3 = Float64(b / a); else tmp_3 = t_2; end tmp_2 = tmp_3; elseif (t_4 <= -2e-210) tmp_4 = 0.0 if (b >= 0.0) tmp_4 = Float64(2.0 / Float64(Float64(Float64(-b) - t_1) / c)); else tmp_4 = Float64(Float64(t_1 - b) / Float64(2.0 * a)); end tmp_2 = tmp_4; elseif (t_4 <= 1e-216) tmp_5 = 0.0 if (b >= 0.0) tmp_5 = t_0; else tmp_5 = Float64(Float64(Float64(Float64(2.0 / Float64(b / Float64(c * a))) - b) - b) / Float64(2.0 * a)); end tmp_2 = tmp_5; elseif (t_4 <= 1e+237) tmp_2 = t_4; elseif (b >= 0.0) tmp_2 = t_0; else tmp_2 = t_2; end return tmp_2 end
code[a_, b_, c_] := If[GreaterEqual[b, 0.0], N[(N[(2.0 * c), $MachinePrecision] / N[((-b) - N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(4.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 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_] := Block[{t$95$0 = N[(N[(2.0 * c), $MachinePrecision] / N[((-b) - b), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[Sqrt[N[(b * b + N[(c * N[(a * -4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$2 = N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(4.0 * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$4 = If[GreaterEqual[b, 0.0], N[(N[(2.0 * c), $MachinePrecision] / N[((-b) - t$95$3), $MachinePrecision]), $MachinePrecision], N[(N[(t$95$3 - b), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]]}, If[LessEqual[t$95$4, (-Infinity)], If[GreaterEqual[b, 0.0], N[(b / a), $MachinePrecision], t$95$2], If[LessEqual[t$95$4, -2e-210], If[GreaterEqual[b, 0.0], N[(2.0 / N[(N[((-b) - t$95$1), $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision], N[(N[(t$95$1 - b), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]], If[LessEqual[t$95$4, 1e-216], If[GreaterEqual[b, 0.0], t$95$0, N[(N[(N[(N[(2.0 / N[(b / N[(c * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - b), $MachinePrecision] - b), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]], If[LessEqual[t$95$4, 1e+237], t$95$4, If[GreaterEqual[b, 0.0], t$95$0, t$95$2]]]]]]]]]]
\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}\\
\mathbf{else}:\\
\;\;\;\;\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a}\\
\end{array}
\begin{array}{l}
t_0 := \frac{2 \cdot c}{\left(-b\right) - b}\\
t_1 := \sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -4\right)\right)}\\
t_2 := \frac{c}{b} - \frac{b}{a}\\
t_3 := \sqrt{b \cdot b - c \cdot \left(4 \cdot a\right)}\\
t_4 := \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) - t_3}\\
\mathbf{else}:\\
\;\;\;\;\frac{t_3 - b}{2 \cdot a}\\
\end{array}\\
\mathbf{if}\;t_4 \leq -\infty:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{b}{a}\\
\mathbf{else}:\\
\;\;\;\;t_2\\
\end{array}\\
\mathbf{elif}\;t_4 \leq -2 \cdot 10^{-210}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2}{\frac{\left(-b\right) - t_1}{c}}\\
\mathbf{else}:\\
\;\;\;\;\frac{t_1 - b}{2 \cdot a}\\
\end{array}\\
\mathbf{elif}\;t_4 \leq 10^{-216}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;t_0\\
\mathbf{else}:\\
\;\;\;\;\frac{\left(\frac{2}{\frac{b}{c \cdot a}} - b\right) - b}{2 \cdot a}\\
\end{array}\\
\mathbf{elif}\;t_4 \leq 10^{+237}:\\
\;\;\;\;t_4\\
\mathbf{elif}\;b \geq 0:\\
\;\;\;\;t_0\\
\mathbf{else}:\\
\;\;\;\;t_2\\
\end{array}
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
if (if (>=.f64 b 0) (/.f64 (*.f64 2 c) (-.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 4 a) c))))) (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 4 a) c)))) (*.f64 2 a))) < -inf.0Initial program 49.8%
Simplified49.8%
[Start]49.8 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}\\
\mathbf{else}:\\
\;\;\;\;\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a}\\
\end{array}
\] |
|---|
Taylor expanded in b around inf 49.8%
Simplified49.8%
[Start]49.8 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2}{-2 \cdot \frac{b}{c} + 2 \cdot \frac{a}{b}}\\
\mathbf{else}:\\
\;\;\;\;\frac{\sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -4\right)\right)} - b}{2 \cdot a}\\
\end{array}
\] |
|---|---|
fma-def [=>]49.8 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2}{\color{blue}{\mathsf{fma}\left(-2, \frac{b}{c}, 2 \cdot \frac{a}{b}\right)}}\\
\mathbf{else}:\\
\;\;\;\;\frac{\sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -4\right)\right)} - b}{2 \cdot a}\\
\end{array}
\] |
Taylor expanded in b around -inf 81.6%
Simplified86.2%
[Start]81.6 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2}{\mathsf{fma}\left(-2, \frac{b}{c}, 2 \cdot \frac{a}{b}\right)}\\
\mathbf{else}:\\
\;\;\;\;\frac{\left(2 \cdot \frac{c \cdot a}{b} + -1 \cdot b\right) - b}{2 \cdot a}\\
\end{array}
\] |
|---|---|
fma-def [=>]81.6 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2}{\mathsf{fma}\left(-2, \frac{b}{c}, 2 \cdot \frac{a}{b}\right)}\\
\mathbf{else}:\\
\;\;\;\;\frac{\mathsf{fma}\left(2, \frac{c \cdot a}{b}, -1 \cdot b\right) - b}{2 \cdot a}\\
\end{array}
\] |
associate-/l* [=>]86.2 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2}{\mathsf{fma}\left(-2, \frac{b}{c}, 2 \cdot \frac{a}{b}\right)}\\
\mathbf{else}:\\
\;\;\;\;\frac{\mathsf{fma}\left(2, \frac{c}{\frac{b}{a}}, -1 \cdot b\right) - b}{2 \cdot a}\\
\end{array}
\] |
mul-1-neg [=>]86.2 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2}{\mathsf{fma}\left(-2, \frac{b}{c}, 2 \cdot \frac{a}{b}\right)}\\
\mathbf{else}:\\
\;\;\;\;\frac{\mathsf{fma}\left(2, \frac{c}{\frac{b}{a}}, -b\right) - b}{2 \cdot a}\\
\end{array}
\] |
Taylor expanded in b around 0 86.2%
Taylor expanded in c around 0 86.3%
Simplified86.3%
[Start]86.3 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{b} + -1 \cdot \frac{b}{a}\\
\end{array}
\] |
|---|---|
mul-1-neg [=>]86.3 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{b}{a}\\
\mathbf{else}:\\
\;\;\;\;\color{blue}{\frac{c}{b} + \left(-\frac{b}{a}\right)}\\
\end{array}
\] |
unsub-neg [=>]86.3 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\end{array}
\] |
if -inf.0 < (if (>=.f64 b 0) (/.f64 (*.f64 2 c) (-.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 4 a) c))))) (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 4 a) c)))) (*.f64 2 a))) < -2.0000000000000001e-210Initial program 95.7%
Simplified95.7%
[Start]95.7 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}\\
\mathbf{else}:\\
\;\;\;\;\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a}\\
\end{array}
\] |
|---|
if -2.0000000000000001e-210 < (if (>=.f64 b 0) (/.f64 (*.f64 2 c) (-.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 4 a) c))))) (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 4 a) c)))) (*.f64 2 a))) < 1e-216Initial program 52.3%
Taylor expanded in b around inf 85.0%
Taylor expanded in b around -inf 85.0%
Simplified85.0%
[Start]85.0 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) - b}\\
\mathbf{else}:\\
\;\;\;\;\frac{\left(-b\right) + \left(2 \cdot \frac{c \cdot a}{b} + -1 \cdot b\right)}{2 \cdot a}\\
\end{array}
\] |
|---|---|
mul-1-neg [=>]85.0 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) - b}\\
\mathbf{else}:\\
\;\;\;\;\frac{\left(-b\right) + \left(2 \cdot \frac{c \cdot a}{b} + \left(-b\right)\right)}{2 \cdot a}\\
\end{array}
\] |
unsub-neg [=>]85.0 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) - b}\\
\mathbf{else}:\\
\;\;\;\;\frac{\left(-b\right) + \left(2 \cdot \frac{c \cdot a}{b} - b\right)}{2 \cdot a}\\
\end{array}
\] |
associate-*r/ [=>]85.0 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) - b}\\
\mathbf{else}:\\
\;\;\;\;\frac{\left(-b\right) + \left(\frac{2 \cdot \left(c \cdot a\right)}{b} - b\right)}{2 \cdot a}\\
\end{array}
\] |
*-commutative [<=]85.0 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) - b}\\
\mathbf{else}:\\
\;\;\;\;\frac{\left(-b\right) + \left(\frac{2 \cdot \left(a \cdot c\right)}{b} - b\right)}{2 \cdot a}\\
\end{array}
\] |
associate-/l* [=>]85.0 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) - b}\\
\mathbf{else}:\\
\;\;\;\;\frac{\left(-b\right) + \left(\frac{2}{\frac{b}{a \cdot c}} - b\right)}{2 \cdot a}\\
\end{array}
\] |
*-commutative [=>]85.0 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) - b}\\
\mathbf{else}:\\
\;\;\;\;\frac{\left(-b\right) + \left(\frac{2}{\frac{b}{c \cdot a}} - b\right)}{2 \cdot a}\\
\end{array}
\] |
if 1e-216 < (if (>=.f64 b 0) (/.f64 (*.f64 2 c) (-.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 4 a) c))))) (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 4 a) c)))) (*.f64 2 a))) < 9.9999999999999994e236Initial program 94.5%
if 9.9999999999999994e236 < (if (>=.f64 b 0) (/.f64 (*.f64 2 c) (-.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 4 a) c))))) (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 4 a) c)))) (*.f64 2 a))) Initial program 42.0%
Taylor expanded in b around inf 44.6%
Taylor expanded in b around -inf 85.0%
Simplified85.0%
[Start]85.0 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) - b}\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{b} + -1 \cdot \frac{b}{a}\\
\end{array}
\] |
|---|---|
mul-1-neg [=>]85.0 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) - b}\\
\mathbf{else}:\\
\;\;\;\;\color{blue}{\frac{c}{b} + \left(-\frac{b}{a}\right)}\\
\end{array}
\] |
unsub-neg [=>]85.0 | \[ \begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) - b}\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\end{array}
\] |
Final simplification90.6%
| Alternative 1 | |
|---|---|
| Accuracy | 88.7% |
| Cost | 38052 |
| Alternative 2 | |
|---|---|
| Accuracy | 79.2% |
| Cost | 7624 |
| Alternative 3 | |
|---|---|
| Accuracy | 74.8% |
| Cost | 7368 |
| Alternative 4 | |
|---|---|
| Accuracy | 68.0% |
| Cost | 644 |
| Alternative 5 | |
|---|---|
| Accuracy | 36.0% |
| Cost | 580 |
| Alternative 6 | |
|---|---|
| Accuracy | 35.8% |
| Cost | 388 |
| Alternative 7 | |
|---|---|
| Accuracy | 3.7% |
| Cost | 324 |
herbie shell --seed 2023160
(FPCore (a b c)
:name "jeff quadratic root 2"
:precision binary64
(if (>= b 0.0) (/ (* 2.0 c) (- (- b) (sqrt (- (* b b) (* (* 4.0 a) c))))) (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a))))