
(FPCore (a b c) :precision binary64 (/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)))
double code(double a, double b, double c) {
return (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * 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) - ((3.0d0 * a) * c)))) / (3.0d0 * a)
end function
public static double code(double a, double b, double c) {
return (-b + Math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
}
def code(a, b, c): return (-b + math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a)
function code(a, b, c) return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(3.0 * a) * c)))) / Float64(3.0 * a)) end
function tmp = code(a, b, c) tmp = (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a); end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(3.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 7 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (a b c) :precision binary64 (/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)))
double code(double a, double b, double c) {
return (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * 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) - ((3.0d0 * a) * c)))) / (3.0d0 * a)
end function
public static double code(double a, double b, double c) {
return (-b + Math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
}
def code(a, b, c): return (-b + math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a)
function code(a, b, c) return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(3.0 * a) * c)))) / Float64(3.0 * a)) end
function tmp = code(a, b, c) tmp = (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a); end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(3.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a}
\end{array}
(FPCore (a b c)
:precision binary64
(let* ((t_0 (* (* c c) (* (* a a) -1.125))))
(fma
-0.5625
(/ (* (pow c 3.0) (* a a)) (pow b 5.0))
(fma
-0.16666666666666666
(/ (+ (* t_0 t_0) (* 5.0625 (pow (* c a) 4.0))) (* a (pow b 7.0)))
(fma -0.5 (/ c b) (* -0.375 (/ (* c c) (/ (pow b 3.0) a))))))))
double code(double a, double b, double c) {
double t_0 = (c * c) * ((a * a) * -1.125);
return fma(-0.5625, ((pow(c, 3.0) * (a * a)) / pow(b, 5.0)), fma(-0.16666666666666666, (((t_0 * t_0) + (5.0625 * pow((c * a), 4.0))) / (a * pow(b, 7.0))), fma(-0.5, (c / b), (-0.375 * ((c * c) / (pow(b, 3.0) / a))))));
}
function code(a, b, c) t_0 = Float64(Float64(c * c) * Float64(Float64(a * a) * -1.125)) return fma(-0.5625, Float64(Float64((c ^ 3.0) * Float64(a * a)) / (b ^ 5.0)), fma(-0.16666666666666666, Float64(Float64(Float64(t_0 * t_0) + Float64(5.0625 * (Float64(c * a) ^ 4.0))) / Float64(a * (b ^ 7.0))), fma(-0.5, Float64(c / b), Float64(-0.375 * Float64(Float64(c * c) / Float64((b ^ 3.0) / a)))))) end
code[a_, b_, c_] := Block[{t$95$0 = N[(N[(c * c), $MachinePrecision] * N[(N[(a * a), $MachinePrecision] * -1.125), $MachinePrecision]), $MachinePrecision]}, N[(-0.5625 * N[(N[(N[Power[c, 3.0], $MachinePrecision] * N[(a * a), $MachinePrecision]), $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision] + N[(-0.16666666666666666 * N[(N[(N[(t$95$0 * t$95$0), $MachinePrecision] + N[(5.0625 * N[Power[N[(c * a), $MachinePrecision], 4.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * N[Power[b, 7.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-0.5 * N[(c / b), $MachinePrecision] + N[(-0.375 * N[(N[(c * c), $MachinePrecision] / N[(N[Power[b, 3.0], $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(c \cdot c\right) \cdot \left(\left(a \cdot a\right) \cdot -1.125\right)\\
\mathsf{fma}\left(-0.5625, \frac{{c}^{3} \cdot \left(a \cdot a\right)}{{b}^{5}}, \mathsf{fma}\left(-0.16666666666666666, \frac{t_0 \cdot t_0 + 5.0625 \cdot {\left(c \cdot a\right)}^{4}}{a \cdot {b}^{7}}, \mathsf{fma}\left(-0.5, \frac{c}{b}, -0.375 \cdot \frac{c \cdot c}{\frac{{b}^{3}}{a}}\right)\right)\right)
\end{array}
\end{array}
Initial program 17.4%
/-rgt-identity17.4%
metadata-eval17.4%
associate-/r/17.4%
metadata-eval17.4%
metadata-eval17.4%
times-frac17.4%
*-commutative17.4%
times-frac17.4%
*-commutative17.4%
associate-/r*17.4%
associate-*l/17.4%
Simplified17.4%
Taylor expanded in b around inf 98.2%
fma-def98.2%
unpow298.2%
fma-def98.2%
Simplified98.2%
pow198.2%
pow-prod-down98.2%
Applied egg-rr98.2%
unpow198.2%
Simplified98.2%
unpow298.2%
associate-*l*98.2%
associate-*l*98.2%
Applied egg-rr98.2%
Final simplification98.2%
(FPCore (a b c) :precision binary64 (fma -0.5625 (/ (* (pow c 3.0) (* a a)) (pow b 5.0)) (fma -0.5 (/ c b) (* -0.375 (/ (* c c) (/ (pow b 3.0) a))))))
double code(double a, double b, double c) {
return fma(-0.5625, ((pow(c, 3.0) * (a * a)) / pow(b, 5.0)), fma(-0.5, (c / b), (-0.375 * ((c * c) / (pow(b, 3.0) / a)))));
}
function code(a, b, c) return fma(-0.5625, Float64(Float64((c ^ 3.0) * Float64(a * a)) / (b ^ 5.0)), fma(-0.5, Float64(c / b), Float64(-0.375 * Float64(Float64(c * c) / Float64((b ^ 3.0) / a))))) end
code[a_, b_, c_] := N[(-0.5625 * N[(N[(N[Power[c, 3.0], $MachinePrecision] * N[(a * a), $MachinePrecision]), $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision] + N[(-0.5 * N[(c / b), $MachinePrecision] + N[(-0.375 * N[(N[(c * c), $MachinePrecision] / N[(N[Power[b, 3.0], $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-0.5625, \frac{{c}^{3} \cdot \left(a \cdot a\right)}{{b}^{5}}, \mathsf{fma}\left(-0.5, \frac{c}{b}, -0.375 \cdot \frac{c \cdot c}{\frac{{b}^{3}}{a}}\right)\right)
\end{array}
Initial program 17.4%
/-rgt-identity17.4%
metadata-eval17.4%
associate-/r/17.4%
metadata-eval17.4%
metadata-eval17.4%
times-frac17.4%
*-commutative17.4%
times-frac17.4%
*-commutative17.4%
associate-/r*17.4%
associate-*l/17.4%
Simplified17.4%
Taylor expanded in b around inf 97.3%
fma-def97.3%
unpow297.3%
fma-def97.3%
associate-/l*97.3%
unpow297.3%
Simplified97.3%
Final simplification97.3%
(FPCore (a b c) :precision binary64 (if (<= (/ (- (sqrt (- (* b b) (* c (* 3.0 a)))) b) (* 3.0 a)) -100.0) (* -0.3333333333333333 (/ (- b (sqrt (fma b b (* a (* c -3.0))))) a)) (/ (* c -0.5) b)))
double code(double a, double b, double c) {
double tmp;
if (((sqrt(((b * b) - (c * (3.0 * a)))) - b) / (3.0 * a)) <= -100.0) {
tmp = -0.3333333333333333 * ((b - sqrt(fma(b, b, (a * (c * -3.0))))) / a);
} else {
tmp = (c * -0.5) / b;
}
return tmp;
}
function code(a, b, c) tmp = 0.0 if (Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(3.0 * a)))) - b) / Float64(3.0 * a)) <= -100.0) tmp = Float64(-0.3333333333333333 * Float64(Float64(b - sqrt(fma(b, b, Float64(a * Float64(c * -3.0))))) / a)); else tmp = Float64(Float64(c * -0.5) / b); end return tmp end
code[a_, b_, c_] := If[LessEqual[N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(3.0 * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision], -100.0], N[(-0.3333333333333333 * N[(N[(b - N[Sqrt[N[(b * b + N[(a * N[(c * -3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision], N[(N[(c * -0.5), $MachinePrecision] / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\frac{\sqrt{b \cdot b - c \cdot \left(3 \cdot a\right)} - b}{3 \cdot a} \leq -100:\\
\;\;\;\;-0.3333333333333333 \cdot \frac{b - \sqrt{\mathsf{fma}\left(b, b, a \cdot \left(c \cdot -3\right)\right)}}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{c \cdot -0.5}{b}\\
\end{array}
\end{array}
if (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 3 a) c)))) (*.f64 3 a)) < -100Initial program 75.3%
/-rgt-identity75.3%
metadata-eval75.3%
associate-/l*75.3%
associate-*r/75.2%
*-commutative75.2%
associate-*l/75.3%
associate-*r/75.3%
metadata-eval75.3%
metadata-eval75.3%
times-frac75.3%
neg-mul-175.3%
distribute-rgt-neg-in75.3%
times-frac75.3%
metadata-eval75.3%
neg-mul-175.3%
Simplified75.7%
if -100 < (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 3 a) c)))) (*.f64 3 a)) Initial program 12.2%
/-rgt-identity12.2%
metadata-eval12.2%
associate-/r/12.2%
metadata-eval12.2%
metadata-eval12.2%
times-frac12.2%
*-commutative12.2%
times-frac12.2%
*-commutative12.2%
associate-/r*12.2%
associate-*l/12.2%
Simplified12.2%
Taylor expanded in b around inf 94.7%
associate-*r/94.7%
Simplified94.7%
Final simplification93.2%
(FPCore (a b c) :precision binary64 (if (<= (/ (- (sqrt (- (* b b) (* c (* 3.0 a)))) b) (* 3.0 a)) -100.0) (/ (* -0.3333333333333333 (- b (sqrt (fma b b (* (* c a) -3.0))))) a) (/ (* c -0.5) b)))
double code(double a, double b, double c) {
double tmp;
if (((sqrt(((b * b) - (c * (3.0 * a)))) - b) / (3.0 * a)) <= -100.0) {
tmp = (-0.3333333333333333 * (b - sqrt(fma(b, b, ((c * a) * -3.0))))) / a;
} else {
tmp = (c * -0.5) / b;
}
return tmp;
}
function code(a, b, c) tmp = 0.0 if (Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(3.0 * a)))) - b) / Float64(3.0 * a)) <= -100.0) tmp = Float64(Float64(-0.3333333333333333 * Float64(b - sqrt(fma(b, b, Float64(Float64(c * a) * -3.0))))) / a); else tmp = Float64(Float64(c * -0.5) / b); end return tmp end
code[a_, b_, c_] := If[LessEqual[N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(3.0 * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision], -100.0], N[(N[(-0.3333333333333333 * N[(b - N[Sqrt[N[(b * b + N[(N[(c * a), $MachinePrecision] * -3.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision], N[(N[(c * -0.5), $MachinePrecision] / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\frac{\sqrt{b \cdot b - c \cdot \left(3 \cdot a\right)} - b}{3 \cdot a} \leq -100:\\
\;\;\;\;\frac{-0.3333333333333333 \cdot \left(b - \sqrt{\mathsf{fma}\left(b, b, \left(c \cdot a\right) \cdot -3\right)}\right)}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{c \cdot -0.5}{b}\\
\end{array}
\end{array}
if (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 3 a) c)))) (*.f64 3 a)) < -100Initial program 75.3%
/-rgt-identity75.3%
metadata-eval75.3%
associate-/r/75.3%
metadata-eval75.3%
metadata-eval75.3%
times-frac75.3%
*-commutative75.3%
times-frac75.2%
*-commutative75.2%
associate-/r*75.3%
associate-*l/75.3%
Simplified75.8%
if -100 < (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 3 a) c)))) (*.f64 3 a)) Initial program 12.2%
/-rgt-identity12.2%
metadata-eval12.2%
associate-/r/12.2%
metadata-eval12.2%
metadata-eval12.2%
times-frac12.2%
*-commutative12.2%
times-frac12.2%
*-commutative12.2%
associate-/r*12.2%
associate-*l/12.2%
Simplified12.2%
Taylor expanded in b around inf 94.7%
associate-*r/94.7%
Simplified94.7%
Final simplification93.2%
(FPCore (a b c) :precision binary64 (let* ((t_0 (/ (- (sqrt (- (* b b) (* c (* 3.0 a)))) b) (* 3.0 a)))) (if (<= t_0 -100.0) t_0 (/ (* c -0.5) b))))
double code(double a, double b, double c) {
double t_0 = (sqrt(((b * b) - (c * (3.0 * a)))) - b) / (3.0 * a);
double tmp;
if (t_0 <= -100.0) {
tmp = t_0;
} else {
tmp = (c * -0.5) / b;
}
return tmp;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
real(8) :: t_0
real(8) :: tmp
t_0 = (sqrt(((b * b) - (c * (3.0d0 * a)))) - b) / (3.0d0 * a)
if (t_0 <= (-100.0d0)) then
tmp = t_0
else
tmp = (c * (-0.5d0)) / b
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double t_0 = (Math.sqrt(((b * b) - (c * (3.0 * a)))) - b) / (3.0 * a);
double tmp;
if (t_0 <= -100.0) {
tmp = t_0;
} else {
tmp = (c * -0.5) / b;
}
return tmp;
}
def code(a, b, c): t_0 = (math.sqrt(((b * b) - (c * (3.0 * a)))) - b) / (3.0 * a) tmp = 0 if t_0 <= -100.0: tmp = t_0 else: tmp = (c * -0.5) / b return tmp
function code(a, b, c) t_0 = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(3.0 * a)))) - b) / Float64(3.0 * a)) tmp = 0.0 if (t_0 <= -100.0) tmp = t_0; else tmp = Float64(Float64(c * -0.5) / b); end return tmp end
function tmp_2 = code(a, b, c) t_0 = (sqrt(((b * b) - (c * (3.0 * a)))) - b) / (3.0 * a); tmp = 0.0; if (t_0 <= -100.0) tmp = t_0; else tmp = (c * -0.5) / b; end tmp_2 = tmp; end
code[a_, b_, c_] := Block[{t$95$0 = N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(3.0 * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -100.0], t$95$0, N[(N[(c * -0.5), $MachinePrecision] / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{\sqrt{b \cdot b - c \cdot \left(3 \cdot a\right)} - b}{3 \cdot a}\\
\mathbf{if}\;t_0 \leq -100:\\
\;\;\;\;t_0\\
\mathbf{else}:\\
\;\;\;\;\frac{c \cdot -0.5}{b}\\
\end{array}
\end{array}
if (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 3 a) c)))) (*.f64 3 a)) < -100Initial program 75.3%
if -100 < (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 3 a) c)))) (*.f64 3 a)) Initial program 12.2%
/-rgt-identity12.2%
metadata-eval12.2%
associate-/r/12.2%
metadata-eval12.2%
metadata-eval12.2%
times-frac12.2%
*-commutative12.2%
times-frac12.2%
*-commutative12.2%
associate-/r*12.2%
associate-*l/12.2%
Simplified12.2%
Taylor expanded in b around inf 94.7%
associate-*r/94.7%
Simplified94.7%
Final simplification93.1%
(FPCore (a b c) :precision binary64 (fma -0.5 (/ c b) (/ (* (* c c) (* a -0.375)) (pow b 3.0))))
double code(double a, double b, double c) {
return fma(-0.5, (c / b), (((c * c) * (a * -0.375)) / pow(b, 3.0)));
}
function code(a, b, c) return fma(-0.5, Float64(c / b), Float64(Float64(Float64(c * c) * Float64(a * -0.375)) / (b ^ 3.0))) end
code[a_, b_, c_] := N[(-0.5 * N[(c / b), $MachinePrecision] + N[(N[(N[(c * c), $MachinePrecision] * N[(a * -0.375), $MachinePrecision]), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-0.5, \frac{c}{b}, \frac{\left(c \cdot c\right) \cdot \left(a \cdot -0.375\right)}{{b}^{3}}\right)
\end{array}
Initial program 17.4%
/-rgt-identity17.4%
metadata-eval17.4%
associate-/r/17.4%
metadata-eval17.4%
metadata-eval17.4%
times-frac17.4%
*-commutative17.4%
times-frac17.4%
*-commutative17.4%
associate-/r*17.4%
associate-*l/17.4%
Simplified17.4%
Taylor expanded in b around inf 95.9%
fma-def95.9%
associate-*r/95.9%
*-commutative95.9%
associate-*r*95.9%
unpow295.9%
Simplified95.9%
Final simplification95.9%
(FPCore (a b c) :precision binary64 (/ (* c -0.5) b))
double code(double a, double b, double c) {
return (c * -0.5) / 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 * (-0.5d0)) / b
end function
public static double code(double a, double b, double c) {
return (c * -0.5) / b;
}
def code(a, b, c): return (c * -0.5) / b
function code(a, b, c) return Float64(Float64(c * -0.5) / b) end
function tmp = code(a, b, c) tmp = (c * -0.5) / b; end
code[a_, b_, c_] := N[(N[(c * -0.5), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{c \cdot -0.5}{b}
\end{array}
Initial program 17.4%
/-rgt-identity17.4%
metadata-eval17.4%
associate-/r/17.4%
metadata-eval17.4%
metadata-eval17.4%
times-frac17.4%
*-commutative17.4%
times-frac17.4%
*-commutative17.4%
associate-/r*17.4%
associate-*l/17.4%
Simplified17.4%
Taylor expanded in b around inf 90.9%
associate-*r/90.9%
Simplified90.9%
Final simplification90.9%
herbie shell --seed 2023203
(FPCore (a b c)
:name "Cubic critical, 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) (* (* 3.0 a) c)))) (* 3.0 a)))