
(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 (/ (* c -2.0) (+ b (sqrt (+ (* b b) (* a (* c -4.0)))))))
double code(double a, double b, double c) {
return (c * -2.0) / (b + sqrt(((b * b) + (a * (c * -4.0)))));
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = (c * (-2.0d0)) / (b + sqrt(((b * b) + (a * (c * (-4.0d0))))))
end function
public static double code(double a, double b, double c) {
return (c * -2.0) / (b + Math.sqrt(((b * b) + (a * (c * -4.0)))));
}
def code(a, b, c): return (c * -2.0) / (b + math.sqrt(((b * b) + (a * (c * -4.0)))))
function code(a, b, c) return Float64(Float64(c * -2.0) / Float64(b + sqrt(Float64(Float64(b * b) + Float64(a * Float64(c * -4.0)))))) end
function tmp = code(a, b, c) tmp = (c * -2.0) / (b + sqrt(((b * b) + (a * (c * -4.0))))); end
code[a_, b_, c_] := N[(N[(c * -2.0), $MachinePrecision] / N[(b + N[Sqrt[N[(N[(b * b), $MachinePrecision] + N[(a * N[(c * -4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{c \cdot -2}{b + \sqrt{b \cdot b + a \cdot \left(c \cdot -4\right)}}
\end{array}
Initial program 54.1%
/-lowering-/.f64N/A
+-commutativeN/A
unsub-negN/A
--lowering--.f64N/A
sqrt-lowering-sqrt.f64N/A
sub-negN/A
+-lowering-+.f64N/A
*-lowering-*.f64N/A
*-commutativeN/A
associate-*l*N/A
distribute-rgt-neg-inN/A
*-commutativeN/A
*-lowering-*.f64N/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
metadata-evalN/A
*-commutativeN/A
Simplified54.1%
div-invN/A
flip--N/A
associate-*l/N/A
/-lowering-/.f64N/A
Applied egg-rr55.7%
Taylor expanded in b around 0
*-commutativeN/A
*-lowering-*.f6499.5%
Simplified99.5%
(FPCore (a b c)
:precision binary64
(if (<= b 4.0)
(* (/ 0.5 a) (- (sqrt (+ (* b b) (* a (* c -4.0)))) b))
(/
1.0
(-
(* a (+ (/ 1.0 b) (* (* -2.0 a) (* (/ c (* b (* b b))) -0.5))))
(/ b c)))))
double code(double a, double b, double c) {
double tmp;
if (b <= 4.0) {
tmp = (0.5 / a) * (sqrt(((b * b) + (a * (c * -4.0)))) - b);
} else {
tmp = 1.0 / ((a * ((1.0 / b) + ((-2.0 * a) * ((c / (b * (b * b))) * -0.5)))) - (b / 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 (b <= 4.0d0) then
tmp = (0.5d0 / a) * (sqrt(((b * b) + (a * (c * (-4.0d0))))) - b)
else
tmp = 1.0d0 / ((a * ((1.0d0 / b) + (((-2.0d0) * a) * ((c / (b * (b * b))) * (-0.5d0))))) - (b / c))
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= 4.0) {
tmp = (0.5 / a) * (Math.sqrt(((b * b) + (a * (c * -4.0)))) - b);
} else {
tmp = 1.0 / ((a * ((1.0 / b) + ((-2.0 * a) * ((c / (b * (b * b))) * -0.5)))) - (b / c));
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= 4.0: tmp = (0.5 / a) * (math.sqrt(((b * b) + (a * (c * -4.0)))) - b) else: tmp = 1.0 / ((a * ((1.0 / b) + ((-2.0 * a) * ((c / (b * (b * b))) * -0.5)))) - (b / c)) return tmp
function code(a, b, c) tmp = 0.0 if (b <= 4.0) tmp = Float64(Float64(0.5 / a) * Float64(sqrt(Float64(Float64(b * b) + Float64(a * Float64(c * -4.0)))) - b)); else tmp = Float64(1.0 / Float64(Float64(a * Float64(Float64(1.0 / b) + Float64(Float64(-2.0 * a) * Float64(Float64(c / Float64(b * Float64(b * b))) * -0.5)))) - Float64(b / c))); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= 4.0) tmp = (0.5 / a) * (sqrt(((b * b) + (a * (c * -4.0)))) - b); else tmp = 1.0 / ((a * ((1.0 / b) + ((-2.0 * a) * ((c / (b * (b * b))) * -0.5)))) - (b / c)); end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, 4.0], N[(N[(0.5 / a), $MachinePrecision] * N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] + N[(a * N[(c * -4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[(a * N[(N[(1.0 / b), $MachinePrecision] + N[(N[(-2.0 * a), $MachinePrecision] * N[(N[(c / N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(b / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 4:\\
\;\;\;\;\frac{0.5}{a} \cdot \left(\sqrt{b \cdot b + a \cdot \left(c \cdot -4\right)} - b\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{a \cdot \left(\frac{1}{b} + \left(-2 \cdot a\right) \cdot \left(\frac{c}{b \cdot \left(b \cdot b\right)} \cdot -0.5\right)\right) - \frac{b}{c}}\\
\end{array}
\end{array}
if b < 4Initial program 81.2%
/-lowering-/.f64N/A
+-commutativeN/A
unsub-negN/A
--lowering--.f64N/A
sqrt-lowering-sqrt.f64N/A
sub-negN/A
+-lowering-+.f64N/A
*-lowering-*.f64N/A
*-commutativeN/A
associate-*l*N/A
distribute-rgt-neg-inN/A
*-commutativeN/A
*-lowering-*.f64N/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
metadata-evalN/A
*-commutativeN/A
Simplified81.2%
clear-numN/A
associate-/r/N/A
*-lowering-*.f64N/A
*-commutativeN/A
associate-/r*N/A
metadata-evalN/A
/-lowering-/.f64N/A
--lowering--.f64N/A
sqrt-lowering-sqrt.f64N/A
+-lowering-+.f64N/A
*-lowering-*.f64N/A
*-lowering-*.f64N/A
*-lowering-*.f6481.2%
Applied egg-rr81.2%
if 4 < b Initial program 47.9%
/-lowering-/.f64N/A
+-commutativeN/A
unsub-negN/A
--lowering--.f64N/A
sqrt-lowering-sqrt.f64N/A
sub-negN/A
+-lowering-+.f64N/A
*-lowering-*.f64N/A
*-commutativeN/A
associate-*l*N/A
distribute-rgt-neg-inN/A
*-commutativeN/A
*-lowering-*.f64N/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
metadata-evalN/A
*-commutativeN/A
Simplified47.9%
flip-+N/A
fmm-defN/A
*-commutativeN/A
clear-numN/A
sqrt-divN/A
metadata-evalN/A
/-lowering-/.f64N/A
sqrt-lowering-sqrt.f64N/A
Applied egg-rr47.6%
associate-/r*N/A
clear-numN/A
/-lowering-/.f64N/A
/-lowering-/.f64N/A
/-lowering-/.f64N/A
Applied egg-rr47.9%
Taylor expanded in a around 0
+-commutativeN/A
mul-1-negN/A
unsub-negN/A
--lowering--.f64N/A
Simplified92.8%
Final simplification90.6%
(FPCore (a b c) :precision binary64 (/ 1.0 (- (* a (+ (/ 1.0 b) (* (* -2.0 a) (* (/ c (* b (* b b))) -0.5)))) (/ b c))))
double code(double a, double b, double c) {
return 1.0 / ((a * ((1.0 / b) + ((-2.0 * a) * ((c / (b * (b * b))) * -0.5)))) - (b / c));
}
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 * ((1.0d0 / b) + (((-2.0d0) * a) * ((c / (b * (b * b))) * (-0.5d0))))) - (b / c))
end function
public static double code(double a, double b, double c) {
return 1.0 / ((a * ((1.0 / b) + ((-2.0 * a) * ((c / (b * (b * b))) * -0.5)))) - (b / c));
}
def code(a, b, c): return 1.0 / ((a * ((1.0 / b) + ((-2.0 * a) * ((c / (b * (b * b))) * -0.5)))) - (b / c))
function code(a, b, c) return Float64(1.0 / Float64(Float64(a * Float64(Float64(1.0 / b) + Float64(Float64(-2.0 * a) * Float64(Float64(c / Float64(b * Float64(b * b))) * -0.5)))) - Float64(b / c))) end
function tmp = code(a, b, c) tmp = 1.0 / ((a * ((1.0 / b) + ((-2.0 * a) * ((c / (b * (b * b))) * -0.5)))) - (b / c)); end
code[a_, b_, c_] := N[(1.0 / N[(N[(a * N[(N[(1.0 / b), $MachinePrecision] + N[(N[(-2.0 * a), $MachinePrecision] * N[(N[(c / N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(b / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{a \cdot \left(\frac{1}{b} + \left(-2 \cdot a\right) \cdot \left(\frac{c}{b \cdot \left(b \cdot b\right)} \cdot -0.5\right)\right) - \frac{b}{c}}
\end{array}
Initial program 54.1%
/-lowering-/.f64N/A
+-commutativeN/A
unsub-negN/A
--lowering--.f64N/A
sqrt-lowering-sqrt.f64N/A
sub-negN/A
+-lowering-+.f64N/A
*-lowering-*.f64N/A
*-commutativeN/A
associate-*l*N/A
distribute-rgt-neg-inN/A
*-commutativeN/A
*-lowering-*.f64N/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
metadata-evalN/A
*-commutativeN/A
Simplified54.1%
flip-+N/A
fmm-defN/A
*-commutativeN/A
clear-numN/A
sqrt-divN/A
metadata-evalN/A
/-lowering-/.f64N/A
sqrt-lowering-sqrt.f64N/A
Applied egg-rr53.8%
associate-/r*N/A
clear-numN/A
/-lowering-/.f64N/A
/-lowering-/.f64N/A
/-lowering-/.f64N/A
Applied egg-rr54.1%
Taylor expanded in a around 0
+-commutativeN/A
mul-1-negN/A
unsub-negN/A
--lowering--.f64N/A
Simplified88.6%
Final simplification88.6%
(FPCore (a b c) :precision binary64 (/ 1.0 (- (/ a b) (/ b c))))
double code(double a, double b, double c) {
return 1.0 / ((a / b) - (b / c));
}
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) - (b / c))
end function
public static double code(double a, double b, double c) {
return 1.0 / ((a / b) - (b / c));
}
def code(a, b, c): return 1.0 / ((a / b) - (b / c))
function code(a, b, c) return Float64(1.0 / Float64(Float64(a / b) - Float64(b / c))) end
function tmp = code(a, b, c) tmp = 1.0 / ((a / b) - (b / c)); end
code[a_, b_, c_] := N[(1.0 / N[(N[(a / b), $MachinePrecision] - N[(b / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\frac{a}{b} - \frac{b}{c}}
\end{array}
Initial program 54.1%
/-lowering-/.f64N/A
+-commutativeN/A
unsub-negN/A
--lowering--.f64N/A
sqrt-lowering-sqrt.f64N/A
sub-negN/A
+-lowering-+.f64N/A
*-lowering-*.f64N/A
*-commutativeN/A
associate-*l*N/A
distribute-rgt-neg-inN/A
*-commutativeN/A
*-lowering-*.f64N/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
metadata-evalN/A
*-commutativeN/A
Simplified54.1%
flip-+N/A
fmm-defN/A
*-commutativeN/A
clear-numN/A
sqrt-divN/A
metadata-evalN/A
/-lowering-/.f64N/A
sqrt-lowering-sqrt.f64N/A
Applied egg-rr53.8%
associate-/r*N/A
clear-numN/A
/-lowering-/.f64N/A
/-lowering-/.f64N/A
/-lowering-/.f64N/A
Applied egg-rr54.1%
Taylor expanded in a around 0
+-commutativeN/A
mul-1-negN/A
unsub-negN/A
--lowering--.f64N/A
/-lowering-/.f64N/A
/-lowering-/.f6483.0%
Simplified83.0%
(FPCore (a b c) :precision binary64 (/ c (- 0.0 b)))
double code(double a, double b, double c) {
return c / (0.0 - 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 / (0.0d0 - b)
end function
public static double code(double a, double b, double c) {
return c / (0.0 - b);
}
def code(a, b, c): return c / (0.0 - b)
function code(a, b, c) return Float64(c / Float64(0.0 - b)) end
function tmp = code(a, b, c) tmp = c / (0.0 - b); end
code[a_, b_, c_] := N[(c / N[(0.0 - b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{c}{0 - b}
\end{array}
Initial program 54.1%
/-lowering-/.f64N/A
+-commutativeN/A
unsub-negN/A
--lowering--.f64N/A
sqrt-lowering-sqrt.f64N/A
sub-negN/A
+-lowering-+.f64N/A
*-lowering-*.f64N/A
*-commutativeN/A
associate-*l*N/A
distribute-rgt-neg-inN/A
*-commutativeN/A
*-lowering-*.f64N/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
metadata-evalN/A
*-commutativeN/A
Simplified54.1%
flip-+N/A
fmm-defN/A
*-commutativeN/A
clear-numN/A
sqrt-divN/A
metadata-evalN/A
/-lowering-/.f64N/A
sqrt-lowering-sqrt.f64N/A
Applied egg-rr53.8%
Taylor expanded in b around inf
associate-*r/N/A
/-lowering-/.f64N/A
mul-1-negN/A
neg-lowering-neg.f6465.5%
Simplified65.5%
Final simplification65.5%
(FPCore (a b c) :precision binary64 (- 0.0 (/ b a)))
double code(double a, double b, double c) {
return 0.0 - (b / 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 - (b / a)
end function
public static double code(double a, double b, double c) {
return 0.0 - (b / a);
}
def code(a, b, c): return 0.0 - (b / a)
function code(a, b, c) return Float64(0.0 - Float64(b / a)) end
function tmp = code(a, b, c) tmp = 0.0 - (b / a); end
code[a_, b_, c_] := N[(0.0 - N[(b / a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0 - \frac{b}{a}
\end{array}
Initial program 54.1%
/-lowering-/.f64N/A
+-commutativeN/A
unsub-negN/A
--lowering--.f64N/A
sqrt-lowering-sqrt.f64N/A
sub-negN/A
+-lowering-+.f64N/A
*-lowering-*.f64N/A
*-commutativeN/A
associate-*l*N/A
distribute-rgt-neg-inN/A
*-commutativeN/A
*-lowering-*.f64N/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
metadata-evalN/A
*-commutativeN/A
Simplified54.1%
Taylor expanded in b around -inf
mul-1-negN/A
distribute-neg-frac2N/A
mul-1-negN/A
/-lowering-/.f64N/A
mul-1-negN/A
neg-lowering-neg.f6411.5%
Simplified11.5%
Final simplification11.5%
herbie shell --seed 2024163
(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)))