
(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 (/ c (/ (+ b (cbrt (pow (fma b b (* c (* a -4.0))) 1.5))) (/ (* a -2.0) a))))
double code(double a, double b, double c) {
return c / ((b + cbrt(pow(fma(b, b, (c * (a * -4.0))), 1.5))) / ((a * -2.0) / a));
}
function code(a, b, c) return Float64(c / Float64(Float64(b + cbrt((fma(b, b, Float64(c * Float64(a * -4.0))) ^ 1.5))) / Float64(Float64(a * -2.0) / a))) end
code[a_, b_, c_] := N[(c / N[(N[(b + N[Power[N[Power[N[(b * b + N[(c * N[(a * -4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1.5], $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision] / N[(N[(a * -2.0), $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{c}{\frac{b + \sqrt[3]{{\left(\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -4\right)\right)\right)}^{1.5}}}{\frac{a \cdot -2}{a}}}
\end{array}
Initial program 18.3%
/-rgt-identity18.3%
metadata-eval18.3%
associate-/l*18.3%
associate-*r/18.3%
+-commutative18.3%
unsub-neg18.3%
fma-neg18.4%
associate-*l*18.4%
*-commutative18.4%
distribute-rgt-neg-in18.4%
metadata-eval18.4%
associate-/r*18.4%
metadata-eval18.4%
metadata-eval18.4%
Simplified18.4%
fma-udef18.3%
*-commutative18.3%
metadata-eval18.3%
cancel-sign-sub-inv18.3%
associate-*l*18.3%
add-cbrt-cube18.4%
pow318.5%
sqrt-pow218.3%
associate-*l*18.3%
cancel-sign-sub-inv18.3%
metadata-eval18.3%
*-commutative18.3%
fma-udef18.4%
associate-*l*18.4%
metadata-eval18.4%
Applied egg-rr18.4%
flip--18.3%
Applied egg-rr18.3%
fma-neg19.4%
+-commutative19.4%
Simplified19.4%
Taylor expanded in b around 0 0.0%
unpow20.0%
rem-square-sqrt99.1%
Simplified99.1%
expm1-log1p-u82.5%
expm1-udef19.1%
frac-times19.1%
associate-*r*19.1%
*-commutative19.1%
associate-*r*19.1%
Applied egg-rr19.1%
expm1-def82.5%
expm1-log1p99.2%
times-frac99.1%
associate-*l/99.3%
associate-*l*99.4%
associate-/l*99.4%
associate-*r/99.5%
associate-*l*99.5%
metadata-eval99.5%
Simplified99.5%
Final simplification99.5%
(FPCore (a b c) :precision binary64 (- (- (/ (* -2.0 (* c (* (* c c) (* a a)))) (pow b 5.0)) (/ c b)) (/ (* c c) (/ (pow b 3.0) a))))
double code(double a, double b, double c) {
return (((-2.0 * (c * ((c * c) * (a * a)))) / pow(b, 5.0)) - (c / b)) - ((c * 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 = ((((-2.0d0) * (c * ((c * c) * (a * a)))) / (b ** 5.0d0)) - (c / b)) - ((c * c) / ((b ** 3.0d0) / a))
end function
public static double code(double a, double b, double c) {
return (((-2.0 * (c * ((c * c) * (a * a)))) / Math.pow(b, 5.0)) - (c / b)) - ((c * c) / (Math.pow(b, 3.0) / a));
}
def code(a, b, c): return (((-2.0 * (c * ((c * c) * (a * a)))) / math.pow(b, 5.0)) - (c / b)) - ((c * c) / (math.pow(b, 3.0) / a))
function code(a, b, c) return Float64(Float64(Float64(Float64(-2.0 * Float64(c * Float64(Float64(c * c) * Float64(a * a)))) / (b ^ 5.0)) - Float64(c / b)) - Float64(Float64(c * c) / Float64((b ^ 3.0) / a))) end
function tmp = code(a, b, c) tmp = (((-2.0 * (c * ((c * c) * (a * a)))) / (b ^ 5.0)) - (c / b)) - ((c * c) / ((b ^ 3.0) / a)); end
code[a_, b_, c_] := N[(N[(N[(N[(-2.0 * N[(c * N[(N[(c * c), $MachinePrecision] * N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision] - N[(c / b), $MachinePrecision]), $MachinePrecision] - N[(N[(c * c), $MachinePrecision] / N[(N[Power[b, 3.0], $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(\frac{-2 \cdot \left(c \cdot \left(\left(c \cdot c\right) \cdot \left(a \cdot a\right)\right)\right)}{{b}^{5}} - \frac{c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}}
\end{array}
Initial program 18.3%
/-rgt-identity18.3%
metadata-eval18.3%
associate-/l*18.3%
associate-*r/18.3%
+-commutative18.3%
unsub-neg18.3%
fma-neg18.4%
associate-*l*18.4%
*-commutative18.4%
distribute-rgt-neg-in18.4%
metadata-eval18.4%
associate-/r*18.4%
metadata-eval18.4%
metadata-eval18.4%
Simplified18.4%
Taylor expanded in b around inf 97.6%
+-commutative97.6%
mul-1-neg97.6%
unsub-neg97.6%
Simplified97.6%
unpow-prod-down97.6%
pow297.6%
pow297.6%
Applied egg-rr97.6%
Final simplification97.6%
(FPCore (a b c) :precision binary64 (- (- (/ c b)) (/ (* c c) (/ (pow b 3.0) a))))
double code(double a, double b, double c) {
return -(c / b) - ((c * 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 = -(c / b) - ((c * c) / ((b ** 3.0d0) / a))
end function
public static double code(double a, double b, double c) {
return -(c / b) - ((c * c) / (Math.pow(b, 3.0) / a));
}
def code(a, b, c): return -(c / b) - ((c * c) / (math.pow(b, 3.0) / a))
function code(a, b, c) return Float64(Float64(-Float64(c / b)) - Float64(Float64(c * c) / Float64((b ^ 3.0) / a))) end
function tmp = code(a, b, c) tmp = -(c / b) - ((c * c) / ((b ^ 3.0) / a)); end
code[a_, b_, c_] := N[((-N[(c / b), $MachinePrecision]) - N[(N[(c * c), $MachinePrecision] / N[(N[Power[b, 3.0], $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(-\frac{c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}}
\end{array}
Initial program 18.3%
/-rgt-identity18.3%
metadata-eval18.3%
associate-/l*18.3%
associate-*r/18.3%
+-commutative18.3%
unsub-neg18.3%
fma-neg18.4%
associate-*l*18.4%
*-commutative18.4%
distribute-rgt-neg-in18.4%
metadata-eval18.4%
associate-/r*18.4%
metadata-eval18.4%
metadata-eval18.4%
Simplified18.4%
Taylor expanded in b around inf 95.8%
+-commutative95.8%
mul-1-neg95.8%
unsub-neg95.8%
mul-1-neg95.8%
associate-/l*95.8%
unpow295.8%
Simplified95.8%
Final simplification95.8%
(FPCore (a b c) :precision binary64 (* (/ (* c (* a -4.0)) (+ b (+ b (* -2.0 (/ (* c a) b))))) (/ 0.5 a)))
double code(double a, double b, double c) {
return ((c * (a * -4.0)) / (b + (b + (-2.0 * ((c * a) / b))))) * (0.5 / a);
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = ((c * (a * (-4.0d0))) / (b + (b + ((-2.0d0) * ((c * a) / b))))) * (0.5d0 / a)
end function
public static double code(double a, double b, double c) {
return ((c * (a * -4.0)) / (b + (b + (-2.0 * ((c * a) / b))))) * (0.5 / a);
}
def code(a, b, c): return ((c * (a * -4.0)) / (b + (b + (-2.0 * ((c * a) / b))))) * (0.5 / a)
function code(a, b, c) return Float64(Float64(Float64(c * Float64(a * -4.0)) / Float64(b + Float64(b + Float64(-2.0 * Float64(Float64(c * a) / b))))) * Float64(0.5 / a)) end
function tmp = code(a, b, c) tmp = ((c * (a * -4.0)) / (b + (b + (-2.0 * ((c * a) / b))))) * (0.5 / a); end
code[a_, b_, c_] := N[(N[(N[(c * N[(a * -4.0), $MachinePrecision]), $MachinePrecision] / N[(b + N[(b + N[(-2.0 * N[(N[(c * a), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(0.5 / a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{c \cdot \left(a \cdot -4\right)}{b + \left(b + -2 \cdot \frac{c \cdot a}{b}\right)} \cdot \frac{0.5}{a}
\end{array}
Initial program 18.3%
/-rgt-identity18.3%
metadata-eval18.3%
associate-/l*18.3%
associate-*r/18.3%
+-commutative18.3%
unsub-neg18.3%
fma-neg18.4%
associate-*l*18.4%
*-commutative18.4%
distribute-rgt-neg-in18.4%
metadata-eval18.4%
associate-/r*18.4%
metadata-eval18.4%
metadata-eval18.4%
Simplified18.4%
fma-udef18.3%
*-commutative18.3%
metadata-eval18.3%
cancel-sign-sub-inv18.3%
associate-*l*18.3%
add-cbrt-cube18.4%
pow318.5%
sqrt-pow218.3%
associate-*l*18.3%
cancel-sign-sub-inv18.3%
metadata-eval18.3%
*-commutative18.3%
fma-udef18.4%
associate-*l*18.4%
metadata-eval18.4%
Applied egg-rr18.4%
flip--18.3%
Applied egg-rr18.3%
fma-neg19.4%
+-commutative19.4%
Simplified19.4%
Taylor expanded in b around 0 0.0%
unpow20.0%
rem-square-sqrt99.1%
Simplified99.1%
Taylor expanded in b around inf 95.4%
Final simplification95.4%
(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 18.3%
/-rgt-identity18.3%
metadata-eval18.3%
associate-/l*18.3%
associate-*r/18.3%
+-commutative18.3%
unsub-neg18.3%
fma-neg18.4%
associate-*l*18.4%
*-commutative18.4%
distribute-rgt-neg-in18.4%
metadata-eval18.4%
associate-/r*18.4%
metadata-eval18.4%
metadata-eval18.4%
Simplified18.4%
Taylor expanded in b around inf 90.1%
mul-1-neg90.1%
Simplified90.1%
Final simplification90.1%
herbie shell --seed 2023238
(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)))