
(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 c (* a -4.0) 0.0) (* a 2.0)) (+ b (sqrt (fma c (* a -4.0) (* b b))))))
double code(double a, double b, double c) {
return (fma(c, (a * -4.0), 0.0) / (a * 2.0)) / (b + sqrt(fma(c, (a * -4.0), (b * b))));
}
function code(a, b, c) return Float64(Float64(fma(c, Float64(a * -4.0), 0.0) / Float64(a * 2.0)) / Float64(b + sqrt(fma(c, Float64(a * -4.0), Float64(b * b))))) end
code[a_, b_, c_] := N[(N[(N[(c * N[(a * -4.0), $MachinePrecision] + 0.0), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision] / N[(b + N[Sqrt[N[(c * N[(a * -4.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{\mathsf{fma}\left(c, a \cdot -4, 0\right)}{a \cdot 2}}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}
\end{array}
Initial program 19.2%
+-commutativeN/A
unsub-negN/A
--lowering--.f64N/A
sqrt-lowering-sqrt.f64N/A
sub-negN/A
accelerator-lowering-fma.f64N/A
*-commutativeN/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
*-commutativeN/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
metadata-eval19.2
Applied egg-rr19.2%
flip--N/A
/-lowering-/.f64N/A
rem-square-sqrtN/A
--lowering--.f64N/A
+-commutativeN/A
accelerator-lowering-fma.f64N/A
*-lowering-*.f64N/A
*-lowering-*.f64N/A
*-lowering-*.f64N/A
+-commutativeN/A
+-lowering-+.f64N/A
sqrt-lowering-sqrt.f64N/A
+-commutativeN/A
accelerator-lowering-fma.f64N/A
*-lowering-*.f64N/A
*-lowering-*.f6419.4
Applied egg-rr19.4%
associate-/l/N/A
associate-/r*N/A
/-lowering-/.f64N/A
/-lowering-/.f64N/A
associate--l+N/A
+-inversesN/A
accelerator-lowering-fma.f64N/A
*-lowering-*.f64N/A
*-commutativeN/A
*-lowering-*.f64N/A
+-lowering-+.f64N/A
sqrt-lowering-sqrt.f64N/A
accelerator-lowering-fma.f64N/A
*-lowering-*.f64N/A
*-lowering-*.f6499.8
Applied egg-rr99.8%
(FPCore (a b c) :precision binary64 (/ (/ (* -4.0 (* c a)) (+ b (sqrt (fma c (* a -4.0) (* b b))))) (* a 2.0)))
double code(double a, double b, double c) {
return ((-4.0 * (c * a)) / (b + sqrt(fma(c, (a * -4.0), (b * b))))) / (a * 2.0);
}
function code(a, b, c) return Float64(Float64(Float64(-4.0 * Float64(c * a)) / Float64(b + sqrt(fma(c, Float64(a * -4.0), Float64(b * b))))) / Float64(a * 2.0)) end
code[a_, b_, c_] := N[(N[(N[(-4.0 * N[(c * a), $MachinePrecision]), $MachinePrecision] / N[(b + N[Sqrt[N[(c * N[(a * -4.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{-4 \cdot \left(c \cdot a\right)}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}}{a \cdot 2}
\end{array}
Initial program 19.2%
+-commutativeN/A
unsub-negN/A
--lowering--.f64N/A
sqrt-lowering-sqrt.f64N/A
sub-negN/A
accelerator-lowering-fma.f64N/A
*-commutativeN/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
*-commutativeN/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
metadata-eval19.2
Applied egg-rr19.2%
flip--N/A
/-lowering-/.f64N/A
rem-square-sqrtN/A
--lowering--.f64N/A
+-commutativeN/A
accelerator-lowering-fma.f64N/A
*-lowering-*.f64N/A
*-lowering-*.f64N/A
*-lowering-*.f64N/A
+-commutativeN/A
+-lowering-+.f64N/A
sqrt-lowering-sqrt.f64N/A
+-commutativeN/A
accelerator-lowering-fma.f64N/A
*-lowering-*.f64N/A
*-lowering-*.f6419.4
Applied egg-rr19.4%
Taylor expanded in c around 0
*-commutativeN/A
*-lowering-*.f64N/A
*-lowering-*.f6499.5
Simplified99.5%
Final simplification99.5%
(FPCore (a b c) :precision binary64 (/ (fma c (* a -4.0) 0.0) (* a (* 2.0 (+ b (sqrt (fma c (* a -4.0) (* b b))))))))
double code(double a, double b, double c) {
return fma(c, (a * -4.0), 0.0) / (a * (2.0 * (b + sqrt(fma(c, (a * -4.0), (b * b))))));
}
function code(a, b, c) return Float64(fma(c, Float64(a * -4.0), 0.0) / Float64(a * Float64(2.0 * Float64(b + sqrt(fma(c, Float64(a * -4.0), Float64(b * b))))))) end
code[a_, b_, c_] := N[(N[(c * N[(a * -4.0), $MachinePrecision] + 0.0), $MachinePrecision] / N[(a * N[(2.0 * N[(b + N[Sqrt[N[(c * N[(a * -4.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(c, a \cdot -4, 0\right)}{a \cdot \left(2 \cdot \left(b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}\right)\right)}
\end{array}
Initial program 19.2%
+-commutativeN/A
unsub-negN/A
--lowering--.f64N/A
sqrt-lowering-sqrt.f64N/A
sub-negN/A
accelerator-lowering-fma.f64N/A
*-commutativeN/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
*-commutativeN/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
metadata-eval19.2
Applied egg-rr19.2%
flip--N/A
/-lowering-/.f64N/A
rem-square-sqrtN/A
--lowering--.f64N/A
+-commutativeN/A
accelerator-lowering-fma.f64N/A
*-lowering-*.f64N/A
*-lowering-*.f64N/A
*-lowering-*.f64N/A
+-commutativeN/A
+-lowering-+.f64N/A
sqrt-lowering-sqrt.f64N/A
+-commutativeN/A
accelerator-lowering-fma.f64N/A
*-lowering-*.f64N/A
*-lowering-*.f6419.4
Applied egg-rr19.4%
associate-/l/N/A
/-lowering-/.f64N/A
associate--l+N/A
+-inversesN/A
accelerator-lowering-fma.f64N/A
*-lowering-*.f64N/A
*-commutativeN/A
associate-*l*N/A
*-lowering-*.f64N/A
*-lowering-*.f64N/A
+-lowering-+.f64N/A
sqrt-lowering-sqrt.f64N/A
accelerator-lowering-fma.f64N/A
*-lowering-*.f64N/A
*-lowering-*.f6499.4
Applied egg-rr99.4%
(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 19.2%
Taylor expanded in b around inf
distribute-lft-outN/A
associate-/l*N/A
mul-1-negN/A
neg-lowering-neg.f64N/A
/-lowering-/.f64N/A
+-commutativeN/A
*-commutativeN/A
associate-/l*N/A
accelerator-lowering-fma.f64N/A
unpow2N/A
*-lowering-*.f64N/A
/-lowering-/.f64N/A
unpow2N/A
*-lowering-*.f6495.0
Simplified95.0%
Final simplification95.0%
(FPCore (a b c) :precision binary64 (* c (/ (fma a c (* b b)) (* b (* b (- b))))))
double code(double a, double b, double c) {
return c * (fma(a, c, (b * b)) / (b * (b * -b)));
}
function code(a, b, c) return Float64(c * Float64(fma(a, c, Float64(b * b)) / Float64(b * Float64(b * Float64(-b))))) end
code[a_, b_, c_] := N[(c * N[(N[(a * c + N[(b * b), $MachinePrecision]), $MachinePrecision] / N[(b * N[(b * (-b)), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
c \cdot \frac{\mathsf{fma}\left(a, c, b \cdot b\right)}{b \cdot \left(b \cdot \left(-b\right)\right)}
\end{array}
Initial program 19.2%
Taylor expanded in a around 0
Simplified98.2%
Taylor expanded in c around 0
*-lowering-*.f64N/A
sub-negN/A
mul-1-negN/A
associate-/l*N/A
distribute-lft-neg-inN/A
neg-mul-1N/A
accelerator-lowering-fma.f64N/A
neg-mul-1N/A
neg-lowering-neg.f64N/A
/-lowering-/.f64N/A
cube-multN/A
unpow2N/A
*-lowering-*.f64N/A
unpow2N/A
*-lowering-*.f64N/A
distribute-neg-fracN/A
metadata-evalN/A
/-lowering-/.f6494.7
Simplified94.7%
Taylor expanded in b around 0
/-lowering-/.f64N/A
distribute-lft-outN/A
mul-1-negN/A
neg-lowering-neg.f64N/A
accelerator-lowering-fma.f64N/A
unpow2N/A
*-lowering-*.f64N/A
cube-multN/A
unpow2N/A
*-lowering-*.f64N/A
unpow2N/A
*-lowering-*.f6494.6
Simplified94.6%
Final simplification94.6%
(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(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 19.2%
Taylor expanded in b around inf
mul-1-negN/A
distribute-neg-frac2N/A
/-lowering-/.f64N/A
neg-lowering-neg.f6489.3
Simplified89.3%
Final simplification89.3%
(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 19.2%
+-commutativeN/A
unsub-negN/A
--lowering--.f64N/A
sqrt-lowering-sqrt.f64N/A
sub-negN/A
accelerator-lowering-fma.f64N/A
*-commutativeN/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
*-commutativeN/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
metadata-eval19.2
Applied egg-rr19.2%
sub-negN/A
+-commutativeN/A
neg-sub0N/A
flip--N/A
metadata-evalN/A
neg-sub0N/A
pow1/2N/A
metadata-evalN/A
metadata-evalN/A
pow-plusN/A
pow-flipN/A
pow1/2N/A
associate-/r/N/A
frac-addN/A
Applied egg-rr20.3%
Taylor expanded in c around 0
associate-*r/N/A
distribute-rgt1-inN/A
metadata-evalN/A
mul0-lftN/A
metadata-evalN/A
/-lowering-/.f643.3
Simplified3.3%
herbie shell --seed 2024204
(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)))