
(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 8 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
(fma
-0.5625
(/ (* (pow c 3.0) (* a a)) (pow b 5.0))
(fma
-0.5
(/ c b)
(+
(* -0.375 (* (/ a (pow b 3.0)) (* c c)))
(* (/ (/ (pow (* c a) 4.0) a) (pow b 7.0)) -1.0546875)))))
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 * ((a / pow(b, 3.0)) * (c * c))) + (((pow((c * a), 4.0) / a) / pow(b, 7.0)) * -1.0546875))));
}
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(Float64(-0.375 * Float64(Float64(a / (b ^ 3.0)) * Float64(c * c))) + Float64(Float64(Float64((Float64(c * a) ^ 4.0) / a) / (b ^ 7.0)) * -1.0546875)))) 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[(N[(-0.375 * N[(N[(a / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision] * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(N[Power[N[(c * a), $MachinePrecision], 4.0], $MachinePrecision] / a), $MachinePrecision] / N[Power[b, 7.0], $MachinePrecision]), $MachinePrecision] * -1.0546875), $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 \left(\frac{a}{{b}^{3}} \cdot \left(c \cdot c\right)\right) + \frac{\frac{{\left(c \cdot a\right)}^{4}}{a}}{{b}^{7}} \cdot -1.0546875\right)\right)
\end{array}
Initial program 33.8%
Taylor expanded in b around inf 94.8%
fma-def94.8%
*-commutative94.8%
unpow294.8%
fma-def94.8%
fma-def94.8%
Simplified94.8%
Taylor expanded in c around 0 94.8%
Simplified94.8%
frac-times94.8%
div-inv94.8%
metadata-eval94.8%
Applied egg-rr94.8%
associate-/r*94.8%
times-frac94.8%
metadata-eval94.8%
associate-/l*94.8%
Simplified94.8%
fma-udef94.8%
associate-/r/94.8%
associate-/r/94.8%
Applied egg-rr94.8%
Final simplification94.8%
(FPCore (a b c) :precision binary64 (fma -0.5 (/ c b) (fma -0.375 (/ a (/ (pow b 3.0) (* c c))) (/ (* (* a a) (* -0.5625 (pow c 3.0))) (pow b 5.0)))))
double code(double a, double b, double c) {
return fma(-0.5, (c / b), fma(-0.375, (a / (pow(b, 3.0) / (c * c))), (((a * a) * (-0.5625 * pow(c, 3.0))) / pow(b, 5.0))));
}
function code(a, b, c) return fma(-0.5, Float64(c / b), fma(-0.375, Float64(a / Float64((b ^ 3.0) / Float64(c * c))), Float64(Float64(Float64(a * a) * Float64(-0.5625 * (c ^ 3.0))) / (b ^ 5.0)))) end
code[a_, b_, c_] := N[(-0.5 * N[(c / b), $MachinePrecision] + N[(-0.375 * N[(a / N[(N[Power[b, 3.0], $MachinePrecision] / N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(a * a), $MachinePrecision] * N[(-0.5625 * N[Power[c, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-0.5, \frac{c}{b}, \mathsf{fma}\left(-0.375, \frac{a}{\frac{{b}^{3}}{c \cdot c}}, \frac{\left(a \cdot a\right) \cdot \left(-0.5625 \cdot {c}^{3}\right)}{{b}^{5}}\right)\right)
\end{array}
Initial program 33.8%
neg-sub033.8%
sqr-neg33.8%
associate-+l-33.8%
sub0-neg33.8%
neg-mul-133.8%
Simplified33.8%
div-inv33.8%
metadata-eval33.8%
*-commutative33.8%
add-exp-log33.7%
Applied egg-rr33.7%
add-exp-log33.8%
div-inv33.8%
*-commutative33.8%
Applied egg-rr33.8%
Taylor expanded in b around inf 93.4%
+-commutative93.4%
associate-+l+93.4%
+-commutative93.4%
fma-def93.4%
+-commutative93.4%
fma-def93.4%
associate-/l*93.4%
unpow293.4%
associate-*r/93.4%
Simplified93.4%
Final simplification93.4%
(FPCore (a b c) :precision binary64 (fma -0.5 (/ c b) (+ (* -0.375 (* (/ a (pow b 3.0)) (* c c))) (/ (* -0.5625 (pow c 3.0)) (/ (pow b 5.0) (* a a))))))
double code(double a, double b, double c) {
return fma(-0.5, (c / b), ((-0.375 * ((a / pow(b, 3.0)) * (c * c))) + ((-0.5625 * pow(c, 3.0)) / (pow(b, 5.0) / (a * a)))));
}
function code(a, b, c) return fma(-0.5, Float64(c / b), Float64(Float64(-0.375 * Float64(Float64(a / (b ^ 3.0)) * Float64(c * c))) + Float64(Float64(-0.5625 * (c ^ 3.0)) / Float64((b ^ 5.0) / Float64(a * a))))) end
code[a_, b_, c_] := N[(-0.5 * N[(c / b), $MachinePrecision] + N[(N[(-0.375 * N[(N[(a / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision] * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(-0.5625 * N[Power[c, 3.0], $MachinePrecision]), $MachinePrecision] / N[(N[Power[b, 5.0], $MachinePrecision] / N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-0.5, \frac{c}{b}, -0.375 \cdot \left(\frac{a}{{b}^{3}} \cdot \left(c \cdot c\right)\right) + \frac{-0.5625 \cdot {c}^{3}}{\frac{{b}^{5}}{a \cdot a}}\right)
\end{array}
Initial program 33.8%
neg-sub033.8%
sqr-neg33.8%
associate-+l-33.8%
sub0-neg33.8%
neg-mul-133.8%
Simplified33.8%
div-inv33.8%
metadata-eval33.8%
*-commutative33.8%
add-exp-log33.7%
Applied egg-rr33.7%
add-exp-log33.8%
div-inv33.8%
*-commutative33.8%
Applied egg-rr33.8%
Taylor expanded in b around inf 93.4%
+-commutative93.4%
associate-+l+93.4%
+-commutative93.4%
fma-def93.4%
+-commutative93.4%
fma-def93.4%
associate-/l*93.4%
unpow293.4%
associate-*r/93.4%
Simplified93.4%
fma-udef93.4%
associate-/r/93.4%
associate-/l*93.4%
Applied egg-rr93.4%
Final simplification93.4%
(FPCore (a b c) :precision binary64 (let* ((t_0 (/ (- (sqrt (- (* b b) (* c (* 3.0 a)))) b) (* 3.0 a)))) (if (<= t_0 -7e-8) t_0 (* -0.5 (/ c 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 <= -7e-8) {
tmp = t_0;
} else {
tmp = -0.5 * (c / 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 <= (-7d-8)) then
tmp = t_0
else
tmp = (-0.5d0) * (c / 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 <= -7e-8) {
tmp = t_0;
} else {
tmp = -0.5 * (c / 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 <= -7e-8: tmp = t_0 else: tmp = -0.5 * (c / 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 <= -7e-8) tmp = t_0; else tmp = Float64(-0.5 * Float64(c / 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 <= -7e-8) tmp = t_0; else tmp = -0.5 * (c / 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, -7e-8], t$95$0, N[(-0.5 * N[(c / b), $MachinePrecision]), $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 -7 \cdot 10^{-8}:\\
\;\;\;\;t_0\\
\mathbf{else}:\\
\;\;\;\;-0.5 \cdot \frac{c}{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)) < -7.00000000000000048e-8Initial program 65.9%
if -7.00000000000000048e-8 < (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 3 a) c)))) (*.f64 3 a)) Initial program 19.0%
Taylor expanded in b around inf 89.9%
Final simplification82.3%
(FPCore (a b c) :precision binary64 (fma -0.375 (* (/ a (pow b 3.0)) (* c c)) (* -0.5 (/ c b))))
double code(double a, double b, double c) {
return fma(-0.375, ((a / pow(b, 3.0)) * (c * c)), (-0.5 * (c / b)));
}
function code(a, b, c) return fma(-0.375, Float64(Float64(a / (b ^ 3.0)) * Float64(c * c)), Float64(-0.5 * Float64(c / b))) end
code[a_, b_, c_] := N[(-0.375 * N[(N[(a / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision] * N[(c * c), $MachinePrecision]), $MachinePrecision] + N[(-0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-0.375, \frac{a}{{b}^{3}} \cdot \left(c \cdot c\right), -0.5 \cdot \frac{c}{b}\right)
\end{array}
Initial program 33.8%
Taylor expanded in b around inf 90.0%
+-commutative90.0%
fma-def90.0%
associate-/l*90.0%
associate-/r/90.0%
unpow290.0%
Simplified90.0%
Final simplification90.0%
(FPCore (a b c) :precision binary64 (/ (+ (* -1.5 (/ a (/ b c))) (* -1.125 (/ a (/ (/ (pow b 3.0) (* c c)) a)))) (* 3.0 a)))
double code(double a, double b, double c) {
return ((-1.5 * (a / (b / c))) + (-1.125 * (a / ((pow(b, 3.0) / (c * c)) / a)))) / (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 = (((-1.5d0) * (a / (b / c))) + ((-1.125d0) * (a / (((b ** 3.0d0) / (c * c)) / a)))) / (3.0d0 * a)
end function
public static double code(double a, double b, double c) {
return ((-1.5 * (a / (b / c))) + (-1.125 * (a / ((Math.pow(b, 3.0) / (c * c)) / a)))) / (3.0 * a);
}
def code(a, b, c): return ((-1.5 * (a / (b / c))) + (-1.125 * (a / ((math.pow(b, 3.0) / (c * c)) / a)))) / (3.0 * a)
function code(a, b, c) return Float64(Float64(Float64(-1.5 * Float64(a / Float64(b / c))) + Float64(-1.125 * Float64(a / Float64(Float64((b ^ 3.0) / Float64(c * c)) / a)))) / Float64(3.0 * a)) end
function tmp = code(a, b, c) tmp = ((-1.5 * (a / (b / c))) + (-1.125 * (a / (((b ^ 3.0) / (c * c)) / a)))) / (3.0 * a); end
code[a_, b_, c_] := N[(N[(N[(-1.5 * N[(a / N[(b / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-1.125 * N[(a / N[(N[(N[Power[b, 3.0], $MachinePrecision] / N[(c * c), $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1.5 \cdot \frac{a}{\frac{b}{c}} + -1.125 \cdot \frac{a}{\frac{\frac{{b}^{3}}{c \cdot c}}{a}}}{3 \cdot a}
\end{array}
Initial program 33.8%
Taylor expanded in b around inf 89.5%
fma-def89.5%
associate-/l*89.5%
associate-/l*89.5%
unpow289.5%
unpow289.5%
Simplified89.5%
fma-udef89.5%
associate-/l*89.5%
Applied egg-rr89.5%
Final simplification89.5%
(FPCore (a b c) :precision binary64 (if (<= b 7.5e-8) (* 0.3333333333333333 (/ (- (sqrt (+ (* b b) (* c (* a -3.0)))) b) a)) (* -0.5 (/ c b))))
double code(double a, double b, double c) {
double tmp;
if (b <= 7.5e-8) {
tmp = 0.3333333333333333 * ((sqrt(((b * b) + (c * (a * -3.0)))) - b) / a);
} else {
tmp = -0.5 * (c / 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) :: tmp
if (b <= 7.5d-8) then
tmp = 0.3333333333333333d0 * ((sqrt(((b * b) + (c * (a * (-3.0d0))))) - b) / a)
else
tmp = (-0.5d0) * (c / b)
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= 7.5e-8) {
tmp = 0.3333333333333333 * ((Math.sqrt(((b * b) + (c * (a * -3.0)))) - b) / a);
} else {
tmp = -0.5 * (c / b);
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= 7.5e-8: tmp = 0.3333333333333333 * ((math.sqrt(((b * b) + (c * (a * -3.0)))) - b) / a) else: tmp = -0.5 * (c / b) return tmp
function code(a, b, c) tmp = 0.0 if (b <= 7.5e-8) tmp = Float64(0.3333333333333333 * Float64(Float64(sqrt(Float64(Float64(b * b) + Float64(c * Float64(a * -3.0)))) - b) / a)); else tmp = Float64(-0.5 * Float64(c / b)); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= 7.5e-8) tmp = 0.3333333333333333 * ((sqrt(((b * b) + (c * (a * -3.0)))) - b) / a); else tmp = -0.5 * (c / b); end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, 7.5e-8], N[(0.3333333333333333 * N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] + N[(c * N[(a * -3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision], N[(-0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 7.5 \cdot 10^{-8}:\\
\;\;\;\;0.3333333333333333 \cdot \frac{\sqrt{b \cdot b + c \cdot \left(a \cdot -3\right)} - b}{a}\\
\mathbf{else}:\\
\;\;\;\;-0.5 \cdot \frac{c}{b}\\
\end{array}
\end{array}
if b < 7.4999999999999997e-8Initial program 80.6%
neg-sub080.6%
sqr-neg80.6%
associate-+l-80.6%
sub0-neg80.6%
neg-mul-180.6%
Simplified80.2%
div-inv80.3%
metadata-eval80.3%
*-commutative80.3%
add-exp-log79.9%
Applied egg-rr79.9%
add-exp-log80.3%
div-inv80.3%
*-commutative80.3%
Applied egg-rr80.3%
un-div-inv80.3%
Applied egg-rr80.3%
*-rgt-identity80.3%
times-frac80.3%
metadata-eval80.3%
*-commutative80.3%
fma-udef80.4%
unpow280.4%
+-commutative80.4%
associate-*r*80.4%
*-commutative80.4%
associate-*l*80.4%
fma-def80.3%
unpow280.3%
Simplified80.3%
fma-udef80.4%
Applied egg-rr80.4%
if 7.4999999999999997e-8 < b Initial program 31.3%
Taylor expanded in b around inf 81.5%
Final simplification81.4%
(FPCore (a b c) :precision binary64 (* -0.5 (/ c b)))
double code(double a, double b, double c) {
return -0.5 * (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 = (-0.5d0) * (c / b)
end function
public static double code(double a, double b, double c) {
return -0.5 * (c / b);
}
def code(a, b, c): return -0.5 * (c / b)
function code(a, b, c) return Float64(-0.5 * Float64(c / b)) end
function tmp = code(a, b, c) tmp = -0.5 * (c / b); end
code[a_, b_, c_] := N[(-0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
-0.5 \cdot \frac{c}{b}
\end{array}
Initial program 33.8%
Taylor expanded in b around inf 79.5%
Final simplification79.5%
herbie shell --seed 2023285
(FPCore (a b c)
:name "Cubic critical, 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) (* (* 3.0 a) c)))) (* 3.0 a)))