
(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 7 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 (* (/ c (pow b 3.0)) -0.5)))
(/
-1.0
(-
(/ b c)
(*
a
(fma
a
(*
-2.0
(+
t_0
(*
a
(-
(fma
-0.125
(* b (/ (* (/ (pow c 4.0) (pow b 6.0)) 20.0) (pow c 2.0)))
(/ (pow c 2.0) (pow b 5.0)))
(* c (/ t_0 (pow b 2.0)))))))
(/ 1.0 b)))))))
double code(double a, double b, double c) {
double t_0 = (c / pow(b, 3.0)) * -0.5;
return -1.0 / ((b / c) - (a * fma(a, (-2.0 * (t_0 + (a * (fma(-0.125, (b * (((pow(c, 4.0) / pow(b, 6.0)) * 20.0) / pow(c, 2.0))), (pow(c, 2.0) / pow(b, 5.0))) - (c * (t_0 / pow(b, 2.0))))))), (1.0 / b))));
}
function code(a, b, c) t_0 = Float64(Float64(c / (b ^ 3.0)) * -0.5) return Float64(-1.0 / Float64(Float64(b / c) - Float64(a * fma(a, Float64(-2.0 * Float64(t_0 + Float64(a * Float64(fma(-0.125, Float64(b * Float64(Float64(Float64((c ^ 4.0) / (b ^ 6.0)) * 20.0) / (c ^ 2.0))), Float64((c ^ 2.0) / (b ^ 5.0))) - Float64(c * Float64(t_0 / (b ^ 2.0))))))), Float64(1.0 / b))))) end
code[a_, b_, c_] := Block[{t$95$0 = N[(N[(c / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision] * -0.5), $MachinePrecision]}, N[(-1.0 / N[(N[(b / c), $MachinePrecision] - N[(a * N[(a * N[(-2.0 * N[(t$95$0 + N[(a * N[(N[(-0.125 * N[(b * N[(N[(N[(N[Power[c, 4.0], $MachinePrecision] / N[Power[b, 6.0], $MachinePrecision]), $MachinePrecision] * 20.0), $MachinePrecision] / N[Power[c, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[Power[c, 2.0], $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(c * N[(t$95$0 / N[Power[b, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(1.0 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{c}{{b}^{3}} \cdot -0.5\\
\frac{-1}{\frac{b}{c} - a \cdot \mathsf{fma}\left(a, -2 \cdot \left(t\_0 + a \cdot \left(\mathsf{fma}\left(-0.125, b \cdot \frac{\frac{{c}^{4}}{{b}^{6}} \cdot 20}{{c}^{2}}, \frac{{c}^{2}}{{b}^{5}}\right) - c \cdot \frac{t\_0}{{b}^{2}}\right)\right), \frac{1}{b}\right)}
\end{array}
\end{array}
Initial program 55.1%
*-commutative55.1%
+-commutative55.1%
sqr-neg55.1%
unsub-neg55.1%
sqr-neg55.1%
fma-neg55.2%
distribute-lft-neg-in55.2%
*-commutative55.2%
*-commutative55.2%
distribute-rgt-neg-in55.2%
metadata-eval55.2%
Simplified55.2%
Taylor expanded in a around inf 55.0%
clear-num55.0%
inv-pow55.0%
*-commutative55.0%
fma-define55.0%
Applied egg-rr55.0%
unpow-155.0%
associate-/l*55.0%
Simplified55.0%
Taylor expanded in a around 0 92.1%
Simplified92.1%
Final simplification92.1%
(FPCore (a b c)
:precision binary64
(-
(*
(pow c 4.0)
(-
(* -5.0 (/ (pow a 3.0) (pow b 7.0)))
(/ (+ (* 2.0 (/ (pow a 2.0) (pow b 5.0))) (/ a (* c (pow b 3.0)))) c)))
(/ c b)))
double code(double a, double b, double c) {
return (pow(c, 4.0) * ((-5.0 * (pow(a, 3.0) / pow(b, 7.0))) - (((2.0 * (pow(a, 2.0) / pow(b, 5.0))) + (a / (c * pow(b, 3.0)))) / c))) - (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 ** 4.0d0) * (((-5.0d0) * ((a ** 3.0d0) / (b ** 7.0d0))) - (((2.0d0 * ((a ** 2.0d0) / (b ** 5.0d0))) + (a / (c * (b ** 3.0d0)))) / c))) - (c / b)
end function
public static double code(double a, double b, double c) {
return (Math.pow(c, 4.0) * ((-5.0 * (Math.pow(a, 3.0) / Math.pow(b, 7.0))) - (((2.0 * (Math.pow(a, 2.0) / Math.pow(b, 5.0))) + (a / (c * Math.pow(b, 3.0)))) / c))) - (c / b);
}
def code(a, b, c): return (math.pow(c, 4.0) * ((-5.0 * (math.pow(a, 3.0) / math.pow(b, 7.0))) - (((2.0 * (math.pow(a, 2.0) / math.pow(b, 5.0))) + (a / (c * math.pow(b, 3.0)))) / c))) - (c / b)
function code(a, b, c) return Float64(Float64((c ^ 4.0) * Float64(Float64(-5.0 * Float64((a ^ 3.0) / (b ^ 7.0))) - Float64(Float64(Float64(2.0 * Float64((a ^ 2.0) / (b ^ 5.0))) + Float64(a / Float64(c * (b ^ 3.0)))) / c))) - Float64(c / b)) end
function tmp = code(a, b, c) tmp = ((c ^ 4.0) * ((-5.0 * ((a ^ 3.0) / (b ^ 7.0))) - (((2.0 * ((a ^ 2.0) / (b ^ 5.0))) + (a / (c * (b ^ 3.0)))) / c))) - (c / b); end
code[a_, b_, c_] := N[(N[(N[Power[c, 4.0], $MachinePrecision] * N[(N[(-5.0 * N[(N[Power[a, 3.0], $MachinePrecision] / N[Power[b, 7.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(N[(N[(2.0 * N[(N[Power[a, 2.0], $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(a / N[(c * N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(c / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
{c}^{4} \cdot \left(-5 \cdot \frac{{a}^{3}}{{b}^{7}} - \frac{2 \cdot \frac{{a}^{2}}{{b}^{5}} + \frac{a}{c \cdot {b}^{3}}}{c}\right) - \frac{c}{b}
\end{array}
Initial program 55.1%
*-commutative55.1%
Simplified55.1%
Taylor expanded in a around 0 91.8%
Taylor expanded in c around -inf 91.8%
Final simplification91.8%
(FPCore (a b c) :precision binary64 (/ 1.0 (/ (- (* c (fma -2.0 (* c (* -0.5 (/ (pow a 2.0) (pow b 3.0)))) (/ a b))) b) c)))
double code(double a, double b, double c) {
return 1.0 / (((c * fma(-2.0, (c * (-0.5 * (pow(a, 2.0) / pow(b, 3.0)))), (a / b))) - b) / c);
}
function code(a, b, c) return Float64(1.0 / Float64(Float64(Float64(c * fma(-2.0, Float64(c * Float64(-0.5 * Float64((a ^ 2.0) / (b ^ 3.0)))), Float64(a / b))) - b) / c)) end
code[a_, b_, c_] := N[(1.0 / N[(N[(N[(c * N[(-2.0 * N[(c * N[(-0.5 * N[(N[Power[a, 2.0], $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(a / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - b), $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\frac{c \cdot \mathsf{fma}\left(-2, c \cdot \left(-0.5 \cdot \frac{{a}^{2}}{{b}^{3}}\right), \frac{a}{b}\right) - b}{c}}
\end{array}
Initial program 55.1%
*-commutative55.1%
+-commutative55.1%
sqr-neg55.1%
unsub-neg55.1%
sqr-neg55.1%
fma-neg55.2%
distribute-lft-neg-in55.2%
*-commutative55.2%
*-commutative55.2%
distribute-rgt-neg-in55.2%
metadata-eval55.2%
Simplified55.2%
Taylor expanded in a around inf 55.0%
clear-num55.0%
inv-pow55.0%
*-commutative55.0%
fma-define55.0%
Applied egg-rr55.0%
unpow-155.0%
associate-/l*55.0%
Simplified55.0%
Taylor expanded in c around 0 89.0%
neg-mul-189.0%
+-commutative89.0%
unsub-neg89.0%
fma-define89.0%
distribute-rgt-out89.0%
metadata-eval89.0%
Simplified89.0%
Final simplification89.0%
(FPCore (a b c) :precision binary64 (/ -1.0 (* a (/ (+ (/ b c) (* a (- (/ -1.0 b) (* a (/ c (pow b 3.0)))))) a))))
double code(double a, double b, double c) {
return -1.0 / (a * (((b / c) + (a * ((-1.0 / b) - (a * (c / pow(b, 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 = (-1.0d0) / (a * (((b / c) + (a * (((-1.0d0) / b) - (a * (c / (b ** 3.0d0)))))) / a))
end function
public static double code(double a, double b, double c) {
return -1.0 / (a * (((b / c) + (a * ((-1.0 / b) - (a * (c / Math.pow(b, 3.0)))))) / a));
}
def code(a, b, c): return -1.0 / (a * (((b / c) + (a * ((-1.0 / b) - (a * (c / math.pow(b, 3.0)))))) / a))
function code(a, b, c) return Float64(-1.0 / Float64(a * Float64(Float64(Float64(b / c) + Float64(a * Float64(Float64(-1.0 / b) - Float64(a * Float64(c / (b ^ 3.0)))))) / a))) end
function tmp = code(a, b, c) tmp = -1.0 / (a * (((b / c) + (a * ((-1.0 / b) - (a * (c / (b ^ 3.0)))))) / a)); end
code[a_, b_, c_] := N[(-1.0 / N[(a * N[(N[(N[(b / c), $MachinePrecision] + N[(a * N[(N[(-1.0 / b), $MachinePrecision] - N[(a * N[(c / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1}{a \cdot \frac{\frac{b}{c} + a \cdot \left(\frac{-1}{b} - a \cdot \frac{c}{{b}^{3}}\right)}{a}}
\end{array}
Initial program 55.1%
*-commutative55.1%
+-commutative55.1%
sqr-neg55.1%
unsub-neg55.1%
sqr-neg55.1%
fma-neg55.2%
distribute-lft-neg-in55.2%
*-commutative55.2%
*-commutative55.2%
distribute-rgt-neg-in55.2%
metadata-eval55.2%
Simplified55.2%
Taylor expanded in a around inf 55.0%
clear-num55.0%
inv-pow55.0%
*-commutative55.0%
fma-define55.0%
Applied egg-rr55.0%
unpow-155.0%
associate-/l*55.0%
Simplified55.0%
Taylor expanded in a around 0 89.0%
Simplified89.0%
Final simplification89.0%
(FPCore (a b c) :precision binary64 (if (<= b 140.0) (/ (- (sqrt (- (* b b) (* c (* a 4.0)))) b) (* a 2.0)) (/ -1.0 (- (/ b c) (/ a b)))))
double code(double a, double b, double c) {
double tmp;
if (b <= 140.0) {
tmp = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
} else {
tmp = -1.0 / ((b / c) - (a / 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 <= 140.0d0) then
tmp = (sqrt(((b * b) - (c * (a * 4.0d0)))) - b) / (a * 2.0d0)
else
tmp = (-1.0d0) / ((b / c) - (a / b))
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= 140.0) {
tmp = (Math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
} else {
tmp = -1.0 / ((b / c) - (a / b));
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= 140.0: tmp = (math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0) else: tmp = -1.0 / ((b / c) - (a / b)) return tmp
function code(a, b, c) tmp = 0.0 if (b <= 140.0) tmp = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 4.0)))) - b) / Float64(a * 2.0)); else tmp = Float64(-1.0 / Float64(Float64(b / c) - Float64(a / b))); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= 140.0) tmp = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0); else tmp = -1.0 / ((b / c) - (a / b)); end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, 140.0], 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], N[(-1.0 / N[(N[(b / c), $MachinePrecision] - N[(a / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 140:\\
\;\;\;\;\frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{-1}{\frac{b}{c} - \frac{a}{b}}\\
\end{array}
\end{array}
if b < 140Initial program 77.8%
if 140 < b Initial program 46.1%
*-commutative46.1%
+-commutative46.1%
sqr-neg46.1%
unsub-neg46.1%
sqr-neg46.1%
fma-neg46.1%
distribute-lft-neg-in46.1%
*-commutative46.1%
*-commutative46.1%
distribute-rgt-neg-in46.1%
metadata-eval46.1%
Simplified46.1%
Taylor expanded in a around inf 46.0%
clear-num46.0%
inv-pow46.0%
*-commutative46.0%
fma-define46.0%
Applied egg-rr46.0%
unpow-146.0%
associate-/l*46.0%
Simplified46.0%
Taylor expanded in a around 0 88.8%
neg-mul-188.8%
distribute-frac-neg288.8%
+-commutative88.8%
distribute-frac-neg288.8%
unsub-neg88.8%
Simplified88.8%
Final simplification85.6%
(FPCore (a b c) :precision binary64 (/ -1.0 (- (/ b c) (/ a b))))
double code(double a, double b, double c) {
return -1.0 / ((b / c) - (a / b));
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = (-1.0d0) / ((b / c) - (a / b))
end function
public static double code(double a, double b, double c) {
return -1.0 / ((b / c) - (a / b));
}
def code(a, b, c): return -1.0 / ((b / c) - (a / b))
function code(a, b, c) return Float64(-1.0 / Float64(Float64(b / c) - Float64(a / b))) end
function tmp = code(a, b, c) tmp = -1.0 / ((b / c) - (a / b)); end
code[a_, b_, c_] := N[(-1.0 / N[(N[(b / c), $MachinePrecision] - N[(a / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1}{\frac{b}{c} - \frac{a}{b}}
\end{array}
Initial program 55.1%
*-commutative55.1%
+-commutative55.1%
sqr-neg55.1%
unsub-neg55.1%
sqr-neg55.1%
fma-neg55.2%
distribute-lft-neg-in55.2%
*-commutative55.2%
*-commutative55.2%
distribute-rgt-neg-in55.2%
metadata-eval55.2%
Simplified55.2%
Taylor expanded in a around inf 55.0%
clear-num55.0%
inv-pow55.0%
*-commutative55.0%
fma-define55.0%
Applied egg-rr55.0%
unpow-155.0%
associate-/l*55.0%
Simplified55.0%
Taylor expanded in a around 0 82.7%
neg-mul-182.7%
distribute-frac-neg282.7%
+-commutative82.7%
distribute-frac-neg282.7%
unsub-neg82.7%
Simplified82.7%
Final simplification82.7%
(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 55.1%
*-commutative55.1%
Simplified55.1%
Taylor expanded in b around inf 64.5%
associate-*r/64.5%
mul-1-neg64.5%
Simplified64.5%
Final simplification64.5%
herbie shell --seed 2024137
(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)))