
(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
(fma
(fma
(fma
(* -0.25 a)
(* (/ 20.0 b) (/ (pow c 4.0) (pow b 6.0)))
(/ (* -2.0 (pow c 3.0)) (pow b 5.0)))
a
(* (/ c (pow b 3.0)) (- c)))
a
(/ (- c) b)))
double code(double a, double b, double c) {
return fma(fma(fma((-0.25 * a), ((20.0 / b) * (pow(c, 4.0) / pow(b, 6.0))), ((-2.0 * pow(c, 3.0)) / pow(b, 5.0))), a, ((c / pow(b, 3.0)) * -c)), a, (-c / b));
}
function code(a, b, c) return fma(fma(fma(Float64(-0.25 * a), Float64(Float64(20.0 / b) * Float64((c ^ 4.0) / (b ^ 6.0))), Float64(Float64(-2.0 * (c ^ 3.0)) / (b ^ 5.0))), a, Float64(Float64(c / (b ^ 3.0)) * Float64(-c))), a, Float64(Float64(-c) / b)) end
code[a_, b_, c_] := N[(N[(N[(N[(-0.25 * a), $MachinePrecision] * N[(N[(20.0 / b), $MachinePrecision] * N[(N[Power[c, 4.0], $MachinePrecision] / N[Power[b, 6.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(-2.0 * N[Power[c, 3.0], $MachinePrecision]), $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * a + N[(N[(c / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision] * (-c)), $MachinePrecision]), $MachinePrecision] * a + N[((-c) / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.25 \cdot a, \frac{20}{b} \cdot \frac{{c}^{4}}{{b}^{6}}, \frac{-2 \cdot {c}^{3}}{{b}^{5}}\right), a, \frac{c}{{b}^{3}} \cdot \left(-c\right)\right), a, \frac{-c}{b}\right)
\end{array}
Initial program 18.6%
Taylor expanded in a around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
Applied rewrites97.9%
Final simplification97.9%
(FPCore (a b c)
:precision binary64
(fma
(/
(fma
(* (* a a) -5.0)
(pow c 4.0)
(* (* b b) (* (* c c) (fma (- b) b (* (* c a) -2.0)))))
(pow b 7.0))
a
(/ (- c) b)))
double code(double a, double b, double c) {
return fma((fma(((a * a) * -5.0), pow(c, 4.0), ((b * b) * ((c * c) * fma(-b, b, ((c * a) * -2.0))))) / pow(b, 7.0)), a, (-c / b));
}
function code(a, b, c) return fma(Float64(fma(Float64(Float64(a * a) * -5.0), (c ^ 4.0), Float64(Float64(b * b) * Float64(Float64(c * c) * fma(Float64(-b), b, Float64(Float64(c * a) * -2.0))))) / (b ^ 7.0)), a, Float64(Float64(-c) / b)) end
code[a_, b_, c_] := N[(N[(N[(N[(N[(a * a), $MachinePrecision] * -5.0), $MachinePrecision] * N[Power[c, 4.0], $MachinePrecision] + N[(N[(b * b), $MachinePrecision] * N[(N[(c * c), $MachinePrecision] * N[((-b) * b + N[(N[(c * a), $MachinePrecision] * -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Power[b, 7.0], $MachinePrecision]), $MachinePrecision] * a + N[((-c) / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -5, {c}^{4}, \left(b \cdot b\right) \cdot \left(\left(c \cdot c\right) \cdot \mathsf{fma}\left(-b, b, \left(c \cdot a\right) \cdot -2\right)\right)\right)}{{b}^{7}}, a, \frac{-c}{b}\right)
\end{array}
Initial program 18.6%
Taylor expanded in a around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
Applied rewrites97.9%
Taylor expanded in b around 0
Applied rewrites97.9%
Taylor expanded in b around 0
Applied rewrites97.9%
Taylor expanded in c around 0
Applied rewrites97.9%
Final simplification97.9%
(FPCore (a b c) :precision binary64 (fma (* (fma (* (/ c (pow b 5.0)) a) -2.0 (/ -1.0 (pow b 3.0))) (* c c)) a (/ (- c) b)))
double code(double a, double b, double c) {
return fma((fma(((c / pow(b, 5.0)) * a), -2.0, (-1.0 / pow(b, 3.0))) * (c * c)), a, (-c / b));
}
function code(a, b, c) return fma(Float64(fma(Float64(Float64(c / (b ^ 5.0)) * a), -2.0, Float64(-1.0 / (b ^ 3.0))) * Float64(c * c)), a, Float64(Float64(-c) / b)) end
code[a_, b_, c_] := N[(N[(N[(N[(N[(c / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision] * a), $MachinePrecision] * -2.0 + N[(-1.0 / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(c * c), $MachinePrecision]), $MachinePrecision] * a + N[((-c) / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\mathsf{fma}\left(\frac{c}{{b}^{5}} \cdot a, -2, \frac{-1}{{b}^{3}}\right) \cdot \left(c \cdot c\right), a, \frac{-c}{b}\right)
\end{array}
Initial program 18.6%
Taylor expanded in a around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
Applied rewrites97.9%
Taylor expanded in b around 0
Applied rewrites97.9%
Taylor expanded in c around 0
Applied rewrites96.9%
Final simplification96.9%
(FPCore (a b c) :precision binary64 (* (fma (/ (fma (* (- a) b) b (* (* (* a a) c) -2.0)) (pow b 5.0)) c (/ -1.0 b)) c))
double code(double a, double b, double c) {
return fma((fma((-a * b), b, (((a * a) * c) * -2.0)) / pow(b, 5.0)), c, (-1.0 / b)) * c;
}
function code(a, b, c) return Float64(fma(Float64(fma(Float64(Float64(-a) * b), b, Float64(Float64(Float64(a * a) * c) * -2.0)) / (b ^ 5.0)), c, Float64(-1.0 / b)) * c) end
code[a_, b_, c_] := N[(N[(N[(N[(N[((-a) * b), $MachinePrecision] * b + N[(N[(N[(a * a), $MachinePrecision] * c), $MachinePrecision] * -2.0), $MachinePrecision]), $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision] * c + N[(-1.0 / b), $MachinePrecision]), $MachinePrecision] * c), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\frac{\mathsf{fma}\left(\left(-a\right) \cdot b, b, \left(\left(a \cdot a\right) \cdot c\right) \cdot -2\right)}{{b}^{5}}, c, \frac{-1}{b}\right) \cdot c
\end{array}
Initial program 18.6%
Taylor expanded in c around 0
*-commutativeN/A
lower-*.f64N/A
Applied rewrites96.7%
Taylor expanded in b around 0
Applied rewrites96.7%
(FPCore (a b c) :precision binary64 (* (/ (fma (* (* c c) -2.0) (* a a) (* (* (- b) b) (fma a c (* b b)))) (pow b 5.0)) c))
double code(double a, double b, double c) {
return (fma(((c * c) * -2.0), (a * a), ((-b * b) * fma(a, c, (b * b)))) / pow(b, 5.0)) * c;
}
function code(a, b, c) return Float64(Float64(fma(Float64(Float64(c * c) * -2.0), Float64(a * a), Float64(Float64(Float64(-b) * b) * fma(a, c, Float64(b * b)))) / (b ^ 5.0)) * c) end
code[a_, b_, c_] := N[(N[(N[(N[(N[(c * c), $MachinePrecision] * -2.0), $MachinePrecision] * N[(a * a), $MachinePrecision] + N[(N[((-b) * b), $MachinePrecision] * N[(a * c + N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision] * c), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\left(c \cdot c\right) \cdot -2, a \cdot a, \left(\left(-b\right) \cdot b\right) \cdot \mathsf{fma}\left(a, c, b \cdot b\right)\right)}{{b}^{5}} \cdot c
\end{array}
Initial program 18.6%
Taylor expanded in c around 0
*-commutativeN/A
lower-*.f64N/A
Applied rewrites96.7%
Taylor expanded in b around 0
Applied rewrites96.2%
Final simplification96.2%
(FPCore (a b c) :precision binary64 (/ (fma (* c c) (/ a (* b b)) c) (- b)))
double code(double a, double b, double c) {
return fma((c * c), (a / (b * b)), c) / -b;
}
function code(a, b, c) return Float64(fma(Float64(c * c), Float64(a / Float64(b * b)), c) / Float64(-b)) end
code[a_, b_, c_] := N[(N[(N[(c * c), $MachinePrecision] * N[(a / N[(b * b), $MachinePrecision]), $MachinePrecision] + c), $MachinePrecision] / (-b)), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(c \cdot c, \frac{a}{b \cdot b}, c\right)}{-b}
\end{array}
Initial program 18.6%
Taylor expanded in a around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
Applied rewrites97.9%
Taylor expanded in b around inf
distribute-lft-outN/A
associate-*r/N/A
mul-1-negN/A
distribute-neg-frac2N/A
lower-/.f64N/A
+-commutativeN/A
*-commutativeN/A
unpow2N/A
times-fracN/A
lower-fma.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f64N/A
lower-/.f64N/A
lower-neg.f6495.1
Applied rewrites95.1%
Applied rewrites95.1%
(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 18.6%
Taylor expanded in c around 0
associate-*r/N/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6489.7
Applied rewrites89.7%
herbie shell --seed 2024242
(FPCore (a b c)
:name "Quadratic roots, 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) (* (* 4.0 a) c)))) (* 2.0 a)))