
(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:
Herbie found 6 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(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}
(FPCore (a b c)
:precision binary64
(/
(* -2.0 (/ (* c a) a))
(+
b
(sqrt
(/ (fma (pow (* c a) 2.0) -16.0 (pow b 4.0)) (fma b b (* c (* a 4.0))))))))
double code(double a, double b, double c) {
return (-2.0 * ((c * a) / a)) / (b + sqrt((fma(pow((c * a), 2.0), -16.0, pow(b, 4.0)) / fma(b, b, (c * (a * 4.0))))));
}
function code(a, b, c) return Float64(Float64(-2.0 * Float64(Float64(c * a) / a)) / Float64(b + sqrt(Float64(fma((Float64(c * a) ^ 2.0), -16.0, (b ^ 4.0)) / fma(b, b, Float64(c * Float64(a * 4.0))))))) end
code[a_, b_, c_] := N[(N[(-2.0 * N[(N[(c * a), $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision] / N[(b + N[Sqrt[N[(N[(N[Power[N[(c * a), $MachinePrecision], 2.0], $MachinePrecision] * -16.0 + N[Power[b, 4.0], $MachinePrecision]), $MachinePrecision] / N[(b * b + N[(c * N[(a * 4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-2 \cdot \frac{c \cdot a}{a}}{b + \sqrt{\frac{\mathsf{fma}\left({\left(c \cdot a\right)}^{2}, -16, {b}^{4}\right)}{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot 4\right)\right)}}}
\end{array}
Initial program 58.2%
Simplified58.3%
*-commutative58.3%
metadata-eval58.3%
distribute-lft-neg-in58.3%
distribute-rgt-neg-in58.3%
*-commutative58.3%
fma-neg58.2%
flip--58.0%
div-sub58.0%
pow258.0%
pow258.0%
pow-prod-up58.0%
metadata-eval58.0%
fma-def58.2%
associate-*l*58.2%
pow258.2%
associate-*l*58.2%
fma-def58.2%
associate-*l*58.2%
Applied egg-rr58.2%
flip--58.0%
Applied egg-rr58.9%
Taylor expanded in b around 0 99.3%
*-commutative99.3%
Simplified99.3%
div-inv99.3%
Applied egg-rr99.3%
associate-*l/99.4%
associate-*r/99.5%
*-rgt-identity99.5%
associate-*r*99.5%
*-commutative99.5%
*-commutative99.5%
times-frac99.5%
metadata-eval99.5%
*-commutative99.5%
associate-*r*99.5%
+-commutative99.5%
fma-def99.5%
associate-*r*99.5%
*-commutative99.5%
associate-*l*99.5%
Simplified99.5%
Final simplification99.5%
(FPCore (a b c) :precision binary64 (if (<= (/ (- (sqrt (- (* b b) (* c (* a 4.0)))) b) (* a 2.0)) -0.0062) (/ (- (sqrt (- (* b b) (* (* c a) 4.0))) b) (* a 2.0)) (- (/ (- c) b) (* a (/ c (/ (pow b 3.0) c))))))
double code(double a, double b, double c) {
double tmp;
if (((sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0)) <= -0.0062) {
tmp = (sqrt(((b * b) - ((c * a) * 4.0))) - b) / (a * 2.0);
} else {
tmp = (-c / b) - (a * (c / (pow(b, 3.0) / c)));
}
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 (((sqrt(((b * b) - (c * (a * 4.0d0)))) - b) / (a * 2.0d0)) <= (-0.0062d0)) then
tmp = (sqrt(((b * b) - ((c * a) * 4.0d0))) - b) / (a * 2.0d0)
else
tmp = (-c / b) - (a * (c / ((b ** 3.0d0) / c)))
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (((Math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0)) <= -0.0062) {
tmp = (Math.sqrt(((b * b) - ((c * a) * 4.0))) - b) / (a * 2.0);
} else {
tmp = (-c / b) - (a * (c / (Math.pow(b, 3.0) / c)));
}
return tmp;
}
def code(a, b, c): tmp = 0 if ((math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0)) <= -0.0062: tmp = (math.sqrt(((b * b) - ((c * a) * 4.0))) - b) / (a * 2.0) else: tmp = (-c / b) - (a * (c / (math.pow(b, 3.0) / c))) return tmp
function code(a, b, c) tmp = 0.0 if (Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 4.0)))) - b) / Float64(a * 2.0)) <= -0.0062) tmp = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(Float64(c * a) * 4.0))) - b) / Float64(a * 2.0)); else tmp = Float64(Float64(Float64(-c) / b) - Float64(a * Float64(c / Float64((b ^ 3.0) / c)))); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (((sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0)) <= -0.0062) tmp = (sqrt(((b * b) - ((c * a) * 4.0))) - b) / (a * 2.0); else tmp = (-c / b) - (a * (c / ((b ^ 3.0) / c))); end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(a * 4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], -0.0062], N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(c * a), $MachinePrecision] * 4.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[(N[((-c) / b), $MachinePrecision] - N[(a * N[(c / N[(N[Power[b, 3.0], $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2} \leq -0.0062:\\
\;\;\;\;\frac{\sqrt{b \cdot b - \left(c \cdot a\right) \cdot 4} - b}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b} - a \cdot \frac{c}{\frac{{b}^{3}}{c}}\\
\end{array}
\end{array}
if (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 4 a) c)))) (*.f64 2 a)) < -0.00619999999999999978Initial program 80.2%
Simplified80.5%
*-commutative80.5%
metadata-eval80.5%
distribute-lft-neg-in80.5%
distribute-rgt-neg-in80.5%
*-commutative80.5%
fma-neg80.2%
associate-*l*80.2%
Applied egg-rr80.2%
if -0.00619999999999999978 < (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 4 a) c)))) (*.f64 2 a)) Initial program 47.4%
Taylor expanded in b around inf 87.2%
+-commutative87.2%
mul-1-neg87.2%
unsub-neg87.2%
mul-1-neg87.2%
distribute-neg-frac87.2%
associate-/l*87.2%
associate-/r/87.2%
unpow287.2%
associate-/l*87.2%
Simplified87.2%
Final simplification84.9%
(FPCore (a b c) :precision binary64 (let* ((t_0 (* (* c a) -4.0))) (/ (/ t_0 (+ b (sqrt (+ t_0 (* b b))))) (* a 2.0))))
double code(double a, double b, double c) {
double t_0 = (c * a) * -4.0;
return (t_0 / (b + sqrt((t_0 + (b * b))))) / (a * 2.0);
}
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
t_0 = (c * a) * (-4.0d0)
code = (t_0 / (b + sqrt((t_0 + (b * b))))) / (a * 2.0d0)
end function
public static double code(double a, double b, double c) {
double t_0 = (c * a) * -4.0;
return (t_0 / (b + Math.sqrt((t_0 + (b * b))))) / (a * 2.0);
}
def code(a, b, c): t_0 = (c * a) * -4.0 return (t_0 / (b + math.sqrt((t_0 + (b * b))))) / (a * 2.0)
function code(a, b, c) t_0 = Float64(Float64(c * a) * -4.0) return Float64(Float64(t_0 / Float64(b + sqrt(Float64(t_0 + Float64(b * b))))) / Float64(a * 2.0)) end
function tmp = code(a, b, c) t_0 = (c * a) * -4.0; tmp = (t_0 / (b + sqrt((t_0 + (b * b))))) / (a * 2.0); end
code[a_, b_, c_] := Block[{t$95$0 = N[(N[(c * a), $MachinePrecision] * -4.0), $MachinePrecision]}, N[(N[(t$95$0 / N[(b + N[Sqrt[N[(t$95$0 + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(c \cdot a\right) \cdot -4\\
\frac{\frac{t_0}{b + \sqrt{t_0 + b \cdot b}}}{a \cdot 2}
\end{array}
\end{array}
Initial program 58.2%
Simplified58.3%
*-commutative58.3%
metadata-eval58.3%
distribute-lft-neg-in58.3%
distribute-rgt-neg-in58.3%
*-commutative58.3%
fma-neg58.2%
flip--58.0%
div-sub58.0%
pow258.0%
pow258.0%
pow-prod-up58.0%
metadata-eval58.0%
fma-def58.2%
associate-*l*58.2%
pow258.2%
associate-*l*58.2%
fma-def58.2%
associate-*l*58.2%
Applied egg-rr58.2%
flip--58.0%
Applied egg-rr58.9%
Taylor expanded in b around 0 99.3%
*-commutative99.3%
Simplified99.3%
Taylor expanded in b around 0 99.3%
unpow299.3%
*-commutative99.3%
Simplified99.3%
Final simplification99.3%
(FPCore (a b c) :precision binary64 (- (/ (- c) b) (* a (/ c (/ (pow b 3.0) c)))))
double code(double a, double b, double c) {
return (-c / b) - (a * (c / (pow(b, 3.0) / c)));
}
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) - (a * (c / ((b ** 3.0d0) / c)))
end function
public static double code(double a, double b, double c) {
return (-c / b) - (a * (c / (Math.pow(b, 3.0) / c)));
}
def code(a, b, c): return (-c / b) - (a * (c / (math.pow(b, 3.0) / c)))
function code(a, b, c) return Float64(Float64(Float64(-c) / b) - Float64(a * Float64(c / Float64((b ^ 3.0) / c)))) end
function tmp = code(a, b, c) tmp = (-c / b) - (a * (c / ((b ^ 3.0) / c))); end
code[a_, b_, c_] := N[(N[((-c) / b), $MachinePrecision] - N[(a * N[(c / N[(N[Power[b, 3.0], $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-c}{b} - a \cdot \frac{c}{\frac{{b}^{3}}{c}}
\end{array}
Initial program 58.2%
Taylor expanded in b around inf 78.8%
+-commutative78.8%
mul-1-neg78.8%
unsub-neg78.8%
mul-1-neg78.8%
distribute-neg-frac78.8%
associate-/l*78.8%
associate-/r/78.8%
unpow278.8%
associate-/l*78.8%
Simplified78.8%
Final simplification78.8%
(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}
Initial program 58.2%
Taylor expanded in b around inf 61.6%
mul-1-neg61.6%
distribute-neg-frac61.6%
Simplified61.6%
Final simplification61.6%
(FPCore (a b c) :precision binary64 (/ 0.0 a))
double code(double a, double b, double c) {
return 0.0 / a;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = 0.0d0 / a
end function
public static double code(double a, double b, double c) {
return 0.0 / a;
}
def code(a, b, c): return 0.0 / a
function code(a, b, c) return Float64(0.0 / a) end
function tmp = code(a, b, c) tmp = 0.0 / a; end
code[a_, b_, c_] := N[(0.0 / a), $MachinePrecision]
\begin{array}{l}
\\
\frac{0}{a}
\end{array}
Initial program 58.2%
add-sqr-sqrt58.2%
difference-of-squares58.3%
associate-*l*58.3%
sqrt-prod58.3%
metadata-eval58.3%
associate-*l*58.3%
sqrt-prod58.3%
metadata-eval58.3%
Applied egg-rr58.3%
*-commutative58.3%
*-commutative58.3%
cancel-sign-sub-inv58.3%
metadata-eval58.3%
*-commutative58.3%
Simplified58.3%
Taylor expanded in b around inf 3.2%
associate-*r/3.2%
distribute-rgt-out3.2%
*-commutative3.2%
metadata-eval3.2%
mul0-rgt3.2%
metadata-eval3.2%
Simplified3.2%
Final simplification3.2%
herbie shell --seed 2023268
(FPCore (a b c)
:name "Quadratic roots, narrow range"
:precision binary64
:pre (and (and (and (< 1.0536712127723509e-8 a) (< a 94906265.62425156)) (and (< 1.0536712127723509e-8 b) (< b 94906265.62425156))) (and (< 1.0536712127723509e-8 c) (< c 94906265.62425156)))
(/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))