
(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 5 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
(let* ((t_0 (* a (* c 4.0))))
(/
(/
(fma (* -4.0 a) c 0.0)
(+ b (sqrt (/ (- (pow b 4.0) (pow t_0 2.0)) (fma b b t_0)))))
(* a 2.0))))
double code(double a, double b, double c) {
double t_0 = a * (c * 4.0);
return (fma((-4.0 * a), c, 0.0) / (b + sqrt(((pow(b, 4.0) - pow(t_0, 2.0)) / fma(b, b, t_0))))) / (a * 2.0);
}
function code(a, b, c) t_0 = Float64(a * Float64(c * 4.0)) return Float64(Float64(fma(Float64(-4.0 * a), c, 0.0) / Float64(b + sqrt(Float64(Float64((b ^ 4.0) - (t_0 ^ 2.0)) / fma(b, b, t_0))))) / Float64(a * 2.0)) end
code[a_, b_, c_] := Block[{t$95$0 = N[(a * N[(c * 4.0), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(N[(-4.0 * a), $MachinePrecision] * c + 0.0), $MachinePrecision] / N[(b + N[Sqrt[N[(N[(N[Power[b, 4.0], $MachinePrecision] - N[Power[t$95$0, 2.0], $MachinePrecision]), $MachinePrecision] / N[(b * b + t$95$0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := a \cdot \left(c \cdot 4\right)\\
\frac{\frac{\mathsf{fma}\left(-4 \cdot a, c, 0\right)}{b + \sqrt{\frac{{b}^{4} - {t\_0}^{2}}{\mathsf{fma}\left(b, b, t\_0\right)}}}}{a \cdot 2}
\end{array}
\end{array}
Initial program 32.9%
*-commutative32.9%
+-commutative32.9%
sqr-neg32.9%
unsub-neg32.9%
sqr-neg32.9%
fma-neg33.0%
distribute-lft-neg-in33.0%
*-commutative33.0%
*-commutative33.0%
distribute-rgt-neg-in33.0%
metadata-eval33.0%
Simplified33.0%
*-commutative33.0%
metadata-eval33.0%
distribute-lft-neg-in33.0%
distribute-rgt-neg-in33.0%
*-commutative33.0%
fma-neg32.9%
flip--32.8%
div-sub32.8%
pow232.8%
pow232.8%
pow-prod-up32.8%
metadata-eval32.8%
fma-define32.9%
associate-*l*32.9%
pow232.9%
associate-*l*32.9%
fma-define32.9%
associate-*l*32.9%
Applied egg-rr32.9%
flip--32.8%
Applied egg-rr33.9%
metadata-eval33.9%
unpow233.9%
swap-sqr33.9%
unpow233.9%
associate-*r*33.9%
*-commutative33.9%
associate-*l*33.9%
associate-*r*33.9%
*-commutative33.9%
associate-*l*33.9%
+-commutative33.9%
Simplified33.9%
Taylor expanded in a around inf 99.3%
associate-*r*99.3%
fma-define99.3%
distribute-lft1-in99.3%
metadata-eval99.3%
mul0-lft99.3%
metadata-eval99.3%
Simplified99.3%
Final simplification99.3%
(FPCore (a b c) :precision binary64 (- (* -2.0 (/ (* (pow a 2.0) (pow c 3.0)) (pow b 5.0))) (+ (/ c b) (/ (* a (pow c 2.0)) (pow b 3.0)))))
double code(double a, double b, double c) {
return (-2.0 * ((pow(a, 2.0) * pow(c, 3.0)) / pow(b, 5.0))) - ((c / b) + ((a * pow(c, 2.0)) / pow(b, 3.0)));
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = ((-2.0d0) * (((a ** 2.0d0) * (c ** 3.0d0)) / (b ** 5.0d0))) - ((c / b) + ((a * (c ** 2.0d0)) / (b ** 3.0d0)))
end function
public static double code(double a, double b, double c) {
return (-2.0 * ((Math.pow(a, 2.0) * Math.pow(c, 3.0)) / Math.pow(b, 5.0))) - ((c / b) + ((a * Math.pow(c, 2.0)) / Math.pow(b, 3.0)));
}
def code(a, b, c): return (-2.0 * ((math.pow(a, 2.0) * math.pow(c, 3.0)) / math.pow(b, 5.0))) - ((c / b) + ((a * math.pow(c, 2.0)) / math.pow(b, 3.0)))
function code(a, b, c) return Float64(Float64(-2.0 * Float64(Float64((a ^ 2.0) * (c ^ 3.0)) / (b ^ 5.0))) - Float64(Float64(c / b) + Float64(Float64(a * (c ^ 2.0)) / (b ^ 3.0)))) end
function tmp = code(a, b, c) tmp = (-2.0 * (((a ^ 2.0) * (c ^ 3.0)) / (b ^ 5.0))) - ((c / b) + ((a * (c ^ 2.0)) / (b ^ 3.0))); end
code[a_, b_, c_] := N[(N[(-2.0 * N[(N[(N[Power[a, 2.0], $MachinePrecision] * N[Power[c, 3.0], $MachinePrecision]), $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(N[(c / b), $MachinePrecision] + N[(N[(a * N[Power[c, 2.0], $MachinePrecision]), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
-2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} - \left(\frac{c}{b} + \frac{a \cdot {c}^{2}}{{b}^{3}}\right)
\end{array}
Initial program 32.9%
*-commutative32.9%
Simplified32.9%
Taylor expanded in b around inf 93.3%
Final simplification93.3%
(FPCore (a b c) :precision binary64 (let* ((t_0 (/ (- (sqrt (- (* b b) (* c (* a 4.0)))) b) (* a 2.0)))) (if (<= t_0 -0.0002) t_0 (/ c (- b)))))
double code(double a, double b, double c) {
double t_0 = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
double tmp;
if (t_0 <= -0.0002) {
tmp = t_0;
} else {
tmp = 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 * (a * 4.0d0)))) - b) / (a * 2.0d0)
if (t_0 <= (-0.0002d0)) then
tmp = t_0
else
tmp = 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 * (a * 4.0)))) - b) / (a * 2.0);
double tmp;
if (t_0 <= -0.0002) {
tmp = t_0;
} else {
tmp = c / -b;
}
return tmp;
}
def code(a, b, c): t_0 = (math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0) tmp = 0 if t_0 <= -0.0002: tmp = t_0 else: tmp = c / -b return tmp
function code(a, b, c) t_0 = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 4.0)))) - b) / Float64(a * 2.0)) tmp = 0.0 if (t_0 <= -0.0002) tmp = t_0; else tmp = Float64(c / Float64(-b)); end return tmp end
function tmp_2 = code(a, b, c) t_0 = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0); tmp = 0.0; if (t_0 <= -0.0002) tmp = t_0; else tmp = 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[(a * 4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -0.0002], t$95$0, N[(c / (-b)), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2}\\
\mathbf{if}\;t\_0 \leq -0.0002:\\
\;\;\;\;t\_0\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{-b}\\
\end{array}
\end{array}
if (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 4 a) c)))) (*.f64 2 a)) < -2.0000000000000001e-4Initial program 71.4%
if -2.0000000000000001e-4 < (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 4 a) c)))) (*.f64 2 a)) Initial program 20.3%
*-commutative20.3%
Simplified20.3%
Taylor expanded in b around inf 89.3%
mul-1-neg89.3%
distribute-neg-frac289.3%
Simplified89.3%
Final simplification84.9%
(FPCore (a b c) :precision binary64 (- (/ c (- b)) (* (pow c 2.0) (/ a (pow b 3.0)))))
double code(double a, double b, double c) {
return (c / -b) - (pow(c, 2.0) * (a / pow(b, 3.0)));
}
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) - ((c ** 2.0d0) * (a / (b ** 3.0d0)))
end function
public static double code(double a, double b, double c) {
return (c / -b) - (Math.pow(c, 2.0) * (a / Math.pow(b, 3.0)));
}
def code(a, b, c): return (c / -b) - (math.pow(c, 2.0) * (a / math.pow(b, 3.0)))
function code(a, b, c) return Float64(Float64(c / Float64(-b)) - Float64((c ^ 2.0) * Float64(a / (b ^ 3.0)))) end
function tmp = code(a, b, c) tmp = (c / -b) - ((c ^ 2.0) * (a / (b ^ 3.0))); end
code[a_, b_, c_] := N[(N[(c / (-b)), $MachinePrecision] - N[(N[Power[c, 2.0], $MachinePrecision] * N[(a / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{c}{-b} - {c}^{2} \cdot \frac{a}{{b}^{3}}
\end{array}
Initial program 32.9%
*-commutative32.9%
Simplified32.9%
Taylor expanded in b around inf 89.3%
distribute-lft-out89.3%
associate-/l*89.5%
associate-/l*89.5%
Simplified89.5%
Taylor expanded in a around 0 89.6%
mul-1-neg89.6%
unsub-neg89.6%
mul-1-neg89.6%
distribute-neg-frac289.6%
*-commutative89.6%
associate-/l*89.6%
Simplified89.6%
Final simplification89.6%
(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(c / Float64(-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 32.9%
*-commutative32.9%
Simplified32.9%
Taylor expanded in b around inf 79.9%
mul-1-neg79.9%
distribute-neg-frac279.9%
Simplified79.9%
Final simplification79.9%
herbie shell --seed 2024046
(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)))