
(FPCore (a b c) :precision binary64 (/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)))
double code(double a, double b, double c) {
return (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (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 = (-b + sqrt(((b * b) - ((3.0d0 * a) * c)))) / (3.0d0 * a)
end function
public static double code(double a, double b, double c) {
return (-b + Math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
}
def code(a, b, c): return (-b + math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a)
function code(a, b, c) return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(3.0 * a) * c)))) / Float64(3.0 * a)) end
function tmp = code(a, b, c) tmp = (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a); end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(3.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \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) (* (* 3.0 a) c)))) (* 3.0 a)))
double code(double a, double b, double c) {
return (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (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 = (-b + sqrt(((b * b) - ((3.0d0 * a) * c)))) / (3.0d0 * a)
end function
public static double code(double a, double b, double c) {
return (-b + Math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
}
def code(a, b, c): return (-b + math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a)
function code(a, b, c) return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(3.0 * a) * c)))) / Float64(3.0 * a)) end
function tmp = code(a, b, c) tmp = (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a); end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(3.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a}
\end{array}
(FPCore (a b c)
:precision binary64
(fma
-1.125
(* (* c (/ c (pow b 3.0))) (* a 0.3333333333333333))
(fma
-0.5
(/ c b)
(fma
-1.6875
(* (/ (pow c 3.0) (pow b 5.0)) (* a (* a 0.3333333333333333)))
(/
(* -0.16666666666666666 (* (pow (* c a) 4.0) 6.328125))
(* a (pow b 7.0)))))))
double code(double a, double b, double c) {
return fma(-1.125, ((c * (c / pow(b, 3.0))) * (a * 0.3333333333333333)), fma(-0.5, (c / b), fma(-1.6875, ((pow(c, 3.0) / pow(b, 5.0)) * (a * (a * 0.3333333333333333))), ((-0.16666666666666666 * (pow((c * a), 4.0) * 6.328125)) / (a * pow(b, 7.0))))));
}
function code(a, b, c) return fma(-1.125, Float64(Float64(c * Float64(c / (b ^ 3.0))) * Float64(a * 0.3333333333333333)), fma(-0.5, Float64(c / b), fma(-1.6875, Float64(Float64((c ^ 3.0) / (b ^ 5.0)) * Float64(a * Float64(a * 0.3333333333333333))), Float64(Float64(-0.16666666666666666 * Float64((Float64(c * a) ^ 4.0) * 6.328125)) / Float64(a * (b ^ 7.0)))))) end
code[a_, b_, c_] := N[(-1.125 * N[(N[(c * N[(c / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(a * 0.3333333333333333), $MachinePrecision]), $MachinePrecision] + N[(-0.5 * N[(c / b), $MachinePrecision] + N[(-1.6875 * N[(N[(N[Power[c, 3.0], $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision] * N[(a * N[(a * 0.3333333333333333), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(-0.16666666666666666 * N[(N[Power[N[(c * a), $MachinePrecision], 4.0], $MachinePrecision] * 6.328125), $MachinePrecision]), $MachinePrecision] / N[(a * N[Power[b, 7.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-1.125, \left(c \cdot \frac{c}{{b}^{3}}\right) \cdot \left(a \cdot 0.3333333333333333\right), \mathsf{fma}\left(-0.5, \frac{c}{b}, \mathsf{fma}\left(-1.6875, \frac{{c}^{3}}{{b}^{5}} \cdot \left(a \cdot \left(a \cdot 0.3333333333333333\right)\right), \frac{-0.16666666666666666 \cdot \left({\left(c \cdot a\right)}^{4} \cdot 6.328125\right)}{a \cdot {b}^{7}}\right)\right)\right)
\end{array}
Initial program 17.4%
neg-sub017.4%
associate-+l-17.4%
sub0-neg17.4%
neg-mul-117.4%
associate-*r/17.4%
*-commutative17.4%
metadata-eval17.4%
metadata-eval17.4%
times-frac17.4%
*-commutative17.4%
times-frac17.4%
Simplified17.4%
add-sqr-sqrt17.4%
pow217.4%
Applied egg-rr17.4%
Taylor expanded in b around inf 97.6%
Simplified98.2%
Taylor expanded in c around 0 98.2%
+-commutative98.2%
distribute-rgt-out98.2%
associate-*r*98.2%
metadata-eval98.2%
pow-sqr98.2%
metadata-eval98.2%
pow-sqr98.2%
swap-sqr98.2%
unpow298.2%
unpow298.2%
swap-sqr98.2%
unpow298.2%
unpow298.2%
swap-sqr98.2%
unpow298.2%
unpow298.2%
pow-sqr98.2%
metadata-eval98.2%
metadata-eval98.2%
Simplified98.2%
Final simplification98.2%
(FPCore (a b c) :precision binary64 (fma -0.5625 (/ (pow c 3.0) (/ (pow b 5.0) (* a a))) (fma -0.16666666666666666 (* (/ (pow (* c a) 4.0) a) (/ 6.328125 (pow b 7.0))) (fma -0.5 (/ c b) (* -0.375 (/ (* c c) (/ (pow b 3.0) a)))))))
double code(double a, double b, double c) {
return fma(-0.5625, (pow(c, 3.0) / (pow(b, 5.0) / (a * a))), fma(-0.16666666666666666, ((pow((c * a), 4.0) / a) * (6.328125 / pow(b, 7.0))), fma(-0.5, (c / b), (-0.375 * ((c * c) / (pow(b, 3.0) / a))))));
}
function code(a, b, c) return fma(-0.5625, Float64((c ^ 3.0) / Float64((b ^ 5.0) / Float64(a * a))), fma(-0.16666666666666666, Float64(Float64((Float64(c * a) ^ 4.0) / a) * Float64(6.328125 / (b ^ 7.0))), fma(-0.5, Float64(c / b), Float64(-0.375 * Float64(Float64(c * c) / Float64((b ^ 3.0) / a)))))) end
code[a_, b_, c_] := N[(-0.5625 * N[(N[Power[c, 3.0], $MachinePrecision] / N[(N[Power[b, 5.0], $MachinePrecision] / N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-0.16666666666666666 * N[(N[(N[Power[N[(c * a), $MachinePrecision], 4.0], $MachinePrecision] / a), $MachinePrecision] * N[(6.328125 / N[Power[b, 7.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-0.5 * N[(c / b), $MachinePrecision] + N[(-0.375 * N[(N[(c * c), $MachinePrecision] / N[(N[Power[b, 3.0], $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-0.5625, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \mathsf{fma}\left(-0.16666666666666666, \frac{{\left(c \cdot a\right)}^{4}}{a} \cdot \frac{6.328125}{{b}^{7}}, \mathsf{fma}\left(-0.5, \frac{c}{b}, -0.375 \cdot \frac{c \cdot c}{\frac{{b}^{3}}{a}}\right)\right)\right)
\end{array}
Initial program 17.4%
/-rgt-identity17.4%
metadata-eval17.4%
associate-/l*17.4%
associate-*r/17.4%
*-commutative17.4%
associate-*l/17.4%
associate-*r/17.4%
metadata-eval17.4%
metadata-eval17.4%
times-frac17.4%
neg-mul-117.4%
distribute-rgt-neg-in17.4%
times-frac17.4%
metadata-eval17.4%
neg-mul-117.4%
Simplified17.4%
Taylor expanded in b around inf 98.2%
fma-def98.2%
associate-/l*98.2%
unpow298.2%
fma-def98.2%
Simplified98.2%
Taylor expanded in c around 0 98.2%
distribute-rgt-out98.2%
associate-*r*98.2%
times-frac98.2%
Simplified98.2%
Final simplification98.2%
(FPCore (a b c) :precision binary64 (fma -0.5625 (* (/ (pow c 3.0) (pow b 5.0)) (* a a)) (fma c (/ -0.5 b) (* -0.375 (* c (* (/ c (pow b 3.0)) a))))))
double code(double a, double b, double c) {
return fma(-0.5625, ((pow(c, 3.0) / pow(b, 5.0)) * (a * a)), fma(c, (-0.5 / b), (-0.375 * (c * ((c / pow(b, 3.0)) * a)))));
}
function code(a, b, c) return fma(-0.5625, Float64(Float64((c ^ 3.0) / (b ^ 5.0)) * Float64(a * a)), fma(c, Float64(-0.5 / b), Float64(-0.375 * Float64(c * Float64(Float64(c / (b ^ 3.0)) * a))))) end
code[a_, b_, c_] := N[(-0.5625 * N[(N[(N[Power[c, 3.0], $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision] * N[(a * a), $MachinePrecision]), $MachinePrecision] + N[(c * N[(-0.5 / b), $MachinePrecision] + N[(-0.375 * N[(c * N[(N[(c / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision] * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-0.5625, \frac{{c}^{3}}{{b}^{5}} \cdot \left(a \cdot a\right), \mathsf{fma}\left(c, \frac{-0.5}{b}, -0.375 \cdot \left(c \cdot \left(\frac{c}{{b}^{3}} \cdot a\right)\right)\right)\right)
\end{array}
Initial program 17.4%
/-rgt-identity17.4%
metadata-eval17.4%
associate-/l*17.4%
associate-*r/17.4%
*-commutative17.4%
associate-*l/17.4%
associate-*r/17.4%
metadata-eval17.4%
metadata-eval17.4%
times-frac17.4%
neg-mul-117.4%
distribute-rgt-neg-in17.4%
times-frac17.4%
metadata-eval17.4%
neg-mul-117.4%
Simplified17.4%
Taylor expanded in b around inf 96.8%
fma-def96.8%
associate-/l*96.8%
fma-def96.9%
associate-*r/96.9%
associate-*r*96.9%
unpow296.9%
unpow296.9%
Simplified96.9%
add-log-exp21.9%
associate-/r/21.9%
associate-/l*21.8%
associate-*l*21.8%
Applied egg-rr21.8%
Taylor expanded in c around 0 97.6%
fma-def97.6%
associate-/l*97.6%
associate-/r/97.6%
unpow297.6%
associate-*r/97.6%
*-commutative97.6%
associate-*r/97.3%
fma-def97.3%
associate-*l/97.3%
unpow297.3%
associate-*r/97.3%
*-commutative97.3%
associate-*r*97.3%
*-commutative97.3%
associate-*l*97.3%
Simplified97.3%
Final simplification97.3%
(FPCore (a b c) :precision binary64 (fma -0.5625 (/ (pow c 3.0) (/ (pow b 5.0) (* a a))) (fma -0.375 (/ (* c c) (/ (pow b 3.0) a)) (* -0.5 (/ c b)))))
double code(double a, double b, double c) {
return fma(-0.5625, (pow(c, 3.0) / (pow(b, 5.0) / (a * a))), fma(-0.375, ((c * c) / (pow(b, 3.0) / a)), (-0.5 * (c / b))));
}
function code(a, b, c) return fma(-0.5625, Float64((c ^ 3.0) / Float64((b ^ 5.0) / Float64(a * a))), fma(-0.375, Float64(Float64(c * c) / Float64((b ^ 3.0) / a)), Float64(-0.5 * Float64(c / b)))) end
code[a_, b_, c_] := N[(-0.5625 * N[(N[Power[c, 3.0], $MachinePrecision] / N[(N[Power[b, 5.0], $MachinePrecision] / N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-0.375 * N[(N[(c * c), $MachinePrecision] / N[(N[Power[b, 3.0], $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision] + N[(-0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-0.5625, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \mathsf{fma}\left(-0.375, \frac{c \cdot c}{\frac{{b}^{3}}{a}}, -0.5 \cdot \frac{c}{b}\right)\right)
\end{array}
Initial program 17.4%
/-rgt-identity17.4%
metadata-eval17.4%
associate-/l*17.4%
associate-*r/17.4%
*-commutative17.4%
associate-*l/17.4%
associate-*r/17.4%
metadata-eval17.4%
metadata-eval17.4%
times-frac17.4%
neg-mul-117.4%
distribute-rgt-neg-in17.4%
times-frac17.4%
metadata-eval17.4%
neg-mul-117.4%
Simplified17.4%
Taylor expanded in b around inf 97.6%
fma-def97.6%
associate-/l*97.6%
unpow297.6%
+-commutative97.6%
fma-def97.6%
associate-/l*97.6%
unpow297.6%
Simplified97.6%
Final simplification97.6%
(FPCore (a b c) :precision binary64 (* (/ -0.3333333333333333 a) (fma 1.6875 (/ (pow (* c a) 3.0) (pow b 5.0)) (* (/ c (/ b a)) (+ (/ (* a (* c 1.125)) (* b b)) 1.5)))))
double code(double a, double b, double c) {
return (-0.3333333333333333 / a) * fma(1.6875, (pow((c * a), 3.0) / pow(b, 5.0)), ((c / (b / a)) * (((a * (c * 1.125)) / (b * b)) + 1.5)));
}
function code(a, b, c) return Float64(Float64(-0.3333333333333333 / a) * fma(1.6875, Float64((Float64(c * a) ^ 3.0) / (b ^ 5.0)), Float64(Float64(c / Float64(b / a)) * Float64(Float64(Float64(a * Float64(c * 1.125)) / Float64(b * b)) + 1.5)))) end
code[a_, b_, c_] := N[(N[(-0.3333333333333333 / a), $MachinePrecision] * N[(1.6875 * N[(N[Power[N[(c * a), $MachinePrecision], 3.0], $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision] + N[(N[(c / N[(b / a), $MachinePrecision]), $MachinePrecision] * N[(N[(N[(a * N[(c * 1.125), $MachinePrecision]), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + 1.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-0.3333333333333333}{a} \cdot \mathsf{fma}\left(1.6875, \frac{{\left(c \cdot a\right)}^{3}}{{b}^{5}}, \frac{c}{\frac{b}{a}} \cdot \left(\frac{a \cdot \left(c \cdot 1.125\right)}{b \cdot b} + 1.5\right)\right)
\end{array}
Initial program 17.4%
/-rgt-identity17.4%
metadata-eval17.4%
associate-/l*17.4%
associate-*r/17.4%
*-commutative17.4%
associate-*l/17.4%
associate-*r/17.4%
metadata-eval17.4%
metadata-eval17.4%
times-frac17.4%
neg-mul-117.4%
distribute-rgt-neg-in17.4%
times-frac17.4%
metadata-eval17.4%
neg-mul-117.4%
Simplified17.4%
Taylor expanded in b around inf 96.8%
fma-def96.8%
associate-/l*96.8%
fma-def96.9%
associate-*r/96.9%
associate-*r*96.9%
unpow296.9%
unpow296.9%
Simplified96.9%
add-log-exp21.9%
associate-/r/21.9%
associate-/l*21.8%
associate-*l*21.8%
Applied egg-rr21.8%
add-log-exp96.9%
associate-/r/97.0%
associate-/l*97.0%
unswap-sqr97.0%
Applied egg-rr97.0%
associate-*r/97.2%
associate-/l*97.0%
associate-/r/97.0%
associate-*l/97.0%
cube-prod97.0%
fma-udef96.9%
+-commutative96.9%
Simplified96.8%
Final simplification96.8%
(FPCore (a b c) :precision binary64 (+ (* -0.5 (/ c b)) (* -0.375 (* a (/ (* c c) (pow b 3.0))))))
double code(double a, double b, double c) {
return (-0.5 * (c / b)) + (-0.375 * (a * ((c * c) / pow(b, 3.0))));
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = ((-0.5d0) * (c / b)) + ((-0.375d0) * (a * ((c * c) / (b ** 3.0d0))))
end function
public static double code(double a, double b, double c) {
return (-0.5 * (c / b)) + (-0.375 * (a * ((c * c) / Math.pow(b, 3.0))));
}
def code(a, b, c): return (-0.5 * (c / b)) + (-0.375 * (a * ((c * c) / math.pow(b, 3.0))))
function code(a, b, c) return Float64(Float64(-0.5 * Float64(c / b)) + Float64(-0.375 * Float64(a * Float64(Float64(c * c) / (b ^ 3.0))))) end
function tmp = code(a, b, c) tmp = (-0.5 * (c / b)) + (-0.375 * (a * ((c * c) / (b ^ 3.0)))); end
code[a_, b_, c_] := N[(N[(-0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision] + N[(-0.375 * N[(a * N[(N[(c * c), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
-0.5 \cdot \frac{c}{b} + -0.375 \cdot \left(a \cdot \frac{c \cdot c}{{b}^{3}}\right)
\end{array}
Initial program 17.4%
/-rgt-identity17.4%
metadata-eval17.4%
associate-/l*17.4%
associate-*r/17.4%
*-commutative17.4%
associate-*l/17.4%
associate-*r/17.4%
metadata-eval17.4%
metadata-eval17.4%
times-frac17.4%
neg-mul-117.4%
distribute-rgt-neg-in17.4%
times-frac17.4%
metadata-eval17.4%
neg-mul-117.4%
Simplified17.4%
Taylor expanded in b around inf 96.0%
+-commutative96.0%
fma-def96.0%
associate-/l*96.0%
unpow296.0%
Simplified96.0%
fma-udef96.0%
associate-/r/96.0%
Applied egg-rr96.0%
Final simplification96.0%
(FPCore (a b c) :precision binary64 (* -0.5 (/ c b)))
double code(double a, double b, double c) {
return -0.5 * (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 = (-0.5d0) * (c / b)
end function
public static double code(double a, double b, double c) {
return -0.5 * (c / b);
}
def code(a, b, c): return -0.5 * (c / b)
function code(a, b, c) return Float64(-0.5 * Float64(c / b)) end
function tmp = code(a, b, c) tmp = -0.5 * (c / b); end
code[a_, b_, c_] := N[(-0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
-0.5 \cdot \frac{c}{b}
\end{array}
Initial program 17.4%
/-rgt-identity17.4%
metadata-eval17.4%
associate-/l*17.4%
associate-*r/17.4%
*-commutative17.4%
associate-*l/17.4%
associate-*r/17.4%
metadata-eval17.4%
metadata-eval17.4%
times-frac17.4%
neg-mul-117.4%
distribute-rgt-neg-in17.4%
times-frac17.4%
metadata-eval17.4%
neg-mul-117.4%
Simplified17.4%
Taylor expanded in b around inf 91.3%
Final simplification91.3%
herbie shell --seed 2023194
(FPCore (a b c)
:name "Cubic critical, 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) (* (* 3.0 a) c)))) (* 3.0 a)))