
(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
-0.5625
(/ (pow c 3.0) (/ (pow b 5.0) (* a a)))
(fma
-0.5
(/ c b)
(fma
-0.375
(/ a (/ (pow b 3.0) (* c c)))
(/ (* -1.0546875 (pow (* c a) 4.0)) (* a (pow b 7.0)))))))
double code(double a, double b, double c) {
return fma(-0.5625, (pow(c, 3.0) / (pow(b, 5.0) / (a * a))), fma(-0.5, (c / b), fma(-0.375, (a / (pow(b, 3.0) / (c * c))), ((-1.0546875 * pow((c * a), 4.0)) / (a * pow(b, 7.0))))));
}
function code(a, b, c) return fma(-0.5625, Float64((c ^ 3.0) / Float64((b ^ 5.0) / Float64(a * a))), fma(-0.5, Float64(c / b), fma(-0.375, Float64(a / Float64((b ^ 3.0) / Float64(c * c))), Float64(Float64(-1.0546875 * (Float64(c * a) ^ 4.0)) / Float64(a * (b ^ 7.0)))))) 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[(-0.5 * N[(c / b), $MachinePrecision] + N[(-0.375 * N[(a / N[(N[Power[b, 3.0], $MachinePrecision] / N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(-1.0546875 * N[Power[N[(c * a), $MachinePrecision], 4.0], $MachinePrecision]), $MachinePrecision] / N[(a * N[Power[b, 7.0], $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(-0.5, \frac{c}{b}, \mathsf{fma}\left(-0.375, \frac{a}{\frac{{b}^{3}}{c \cdot c}}, \frac{-1.0546875 \cdot {\left(c \cdot a\right)}^{4}}{a \cdot {b}^{7}}\right)\right)\right)
\end{array}
Initial program 14.6%
neg-sub014.6%
sqr-neg14.6%
associate-+l-14.6%
sub0-neg14.6%
neg-mul-114.6%
Simplified14.7%
add-exp-log14.6%
Applied egg-rr14.6%
Taylor expanded in b around inf 98.8%
Simplified98.8%
expm1-log1p-u97.9%
expm1-udef97.6%
associate-/r/97.6%
Applied egg-rr97.6%
expm1-def97.9%
expm1-log1p98.8%
associate-*l/98.8%
*-commutative98.8%
associate-*r*98.8%
metadata-eval98.8%
Simplified98.8%
Final simplification98.8%
(FPCore (a b c)
:precision binary64
(fma
-0.5625
(* (pow c 3.0) (/ (* a a) (pow b 5.0)))
(fma
c
(/ -0.5 b)
(fma
-0.375
(* (* c c) (/ a (pow b 3.0)))
(/ (* -1.0546875 (pow (* c a) 4.0)) (* a (pow b 7.0)))))))
double code(double a, double b, double c) {
return fma(-0.5625, (pow(c, 3.0) * ((a * a) / pow(b, 5.0))), fma(c, (-0.5 / b), fma(-0.375, ((c * c) * (a / pow(b, 3.0))), ((-1.0546875 * pow((c * a), 4.0)) / (a * pow(b, 7.0))))));
}
function code(a, b, c) return fma(-0.5625, Float64((c ^ 3.0) * Float64(Float64(a * a) / (b ^ 5.0))), fma(c, Float64(-0.5 / b), fma(-0.375, Float64(Float64(c * c) * Float64(a / (b ^ 3.0))), Float64(Float64(-1.0546875 * (Float64(c * a) ^ 4.0)) / Float64(a * (b ^ 7.0)))))) end
code[a_, b_, c_] := N[(-0.5625 * N[(N[Power[c, 3.0], $MachinePrecision] * N[(N[(a * a), $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(c * N[(-0.5 / b), $MachinePrecision] + N[(-0.375 * N[(N[(c * c), $MachinePrecision] * N[(a / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(-1.0546875 * N[Power[N[(c * a), $MachinePrecision], 4.0], $MachinePrecision]), $MachinePrecision] / N[(a * N[Power[b, 7.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-0.5625, {c}^{3} \cdot \frac{a \cdot a}{{b}^{5}}, \mathsf{fma}\left(c, \frac{-0.5}{b}, \mathsf{fma}\left(-0.375, \left(c \cdot c\right) \cdot \frac{a}{{b}^{3}}, \frac{-1.0546875 \cdot {\left(c \cdot a\right)}^{4}}{a \cdot {b}^{7}}\right)\right)\right)
\end{array}
Initial program 14.6%
neg-sub014.6%
sqr-neg14.6%
associate-+l-14.6%
sub0-neg14.6%
neg-mul-114.6%
Simplified14.7%
add-exp-log14.6%
Applied egg-rr14.6%
add-exp-log14.7%
div-inv14.7%
div-inv14.7%
metadata-eval14.7%
Applied egg-rr14.7%
Taylor expanded in b around inf 98.8%
Simplified98.5%
Final simplification98.5%
(FPCore (a b c) :precision binary64 (fma -0.5625 (* (pow c 3.0) (/ (* a a) (pow b 5.0))) (fma -0.375 (/ (* c c) (/ (pow b 3.0) a)) (/ -0.5 (/ b c)))))
double code(double a, double b, double c) {
return fma(-0.5625, (pow(c, 3.0) * ((a * a) / pow(b, 5.0))), fma(-0.375, ((c * c) / (pow(b, 3.0) / a)), (-0.5 / (b / c))));
}
function code(a, b, c) return fma(-0.5625, Float64((c ^ 3.0) * Float64(Float64(a * a) / (b ^ 5.0))), fma(-0.375, Float64(Float64(c * c) / Float64((b ^ 3.0) / a)), Float64(-0.5 / Float64(b / c)))) end
code[a_, b_, c_] := N[(-0.5625 * N[(N[Power[c, 3.0], $MachinePrecision] * N[(N[(a * a), $MachinePrecision] / N[Power[b, 5.0], $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[(b / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-0.5625, {c}^{3} \cdot \frac{a \cdot a}{{b}^{5}}, \mathsf{fma}\left(-0.375, \frac{c \cdot c}{\frac{{b}^{3}}{a}}, \frac{-0.5}{\frac{b}{c}}\right)\right)
\end{array}
Initial program 14.6%
neg-sub014.6%
sqr-neg14.6%
associate-+l-14.6%
sub0-neg14.6%
neg-mul-114.6%
Simplified14.7%
add-exp-log14.6%
Applied egg-rr14.6%
Taylor expanded in b around inf 98.3%
fma-def98.3%
associate-/l*98.3%
associate-/r/98.3%
unpow298.3%
+-commutative98.3%
fma-def98.3%
unpow298.3%
*-commutative98.3%
associate-/l*98.3%
associate-*r/98.3%
associate-/l*97.9%
Simplified97.9%
Final simplification97.9%
(FPCore (a b c) :precision binary64 (fma -0.5625 (* (pow c 3.0) (/ (* a a) (pow b 5.0))) (fma c (/ -0.5 b) (* -0.375 (* (* c c) (/ a (pow b 3.0)))))))
double code(double a, double b, double c) {
return fma(-0.5625, (pow(c, 3.0) * ((a * a) / pow(b, 5.0))), fma(c, (-0.5 / b), (-0.375 * ((c * c) * (a / pow(b, 3.0))))));
}
function code(a, b, c) return fma(-0.5625, Float64((c ^ 3.0) * Float64(Float64(a * a) / (b ^ 5.0))), fma(c, Float64(-0.5 / b), Float64(-0.375 * Float64(Float64(c * c) * Float64(a / (b ^ 3.0)))))) end
code[a_, b_, c_] := N[(-0.5625 * N[(N[Power[c, 3.0], $MachinePrecision] * N[(N[(a * a), $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(c * N[(-0.5 / b), $MachinePrecision] + N[(-0.375 * N[(N[(c * c), $MachinePrecision] * N[(a / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-0.5625, {c}^{3} \cdot \frac{a \cdot a}{{b}^{5}}, \mathsf{fma}\left(c, \frac{-0.5}{b}, -0.375 \cdot \left(\left(c \cdot c\right) \cdot \frac{a}{{b}^{3}}\right)\right)\right)
\end{array}
Initial program 14.6%
neg-sub014.6%
sqr-neg14.6%
associate-+l-14.6%
sub0-neg14.6%
neg-mul-114.6%
Simplified14.7%
add-exp-log14.6%
Applied egg-rr14.6%
add-exp-log14.7%
div-inv14.7%
div-inv14.7%
metadata-eval14.7%
Applied egg-rr14.7%
Taylor expanded in b around inf 98.3%
fma-def98.3%
associate-/l*98.3%
associate-/r/98.3%
unpow298.3%
associate-*r/98.3%
associate-*l/98.0%
*-commutative98.0%
fma-def98.0%
associate-/l*98.0%
associate-/r/98.0%
unpow298.0%
Simplified98.0%
Final simplification98.0%
(FPCore (a b c) :precision binary64 (fma -0.5625 (/ (* (pow c 3.0) (* a a)) (pow b 5.0)) (fma -0.5 (/ c b) (* -0.375 (/ a (/ (pow b 3.0) (* c c)))))))
double code(double a, double b, double c) {
return fma(-0.5625, ((pow(c, 3.0) * (a * a)) / pow(b, 5.0)), fma(-0.5, (c / b), (-0.375 * (a / (pow(b, 3.0) / (c * c))))));
}
function code(a, b, c) return fma(-0.5625, Float64(Float64((c ^ 3.0) * Float64(a * a)) / (b ^ 5.0)), fma(-0.5, Float64(c / b), Float64(-0.375 * Float64(a / Float64((b ^ 3.0) / Float64(c * c)))))) end
code[a_, b_, c_] := N[(-0.5625 * N[(N[(N[Power[c, 3.0], $MachinePrecision] * N[(a * a), $MachinePrecision]), $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision] + N[(-0.5 * N[(c / b), $MachinePrecision] + N[(-0.375 * N[(a / N[(N[Power[b, 3.0], $MachinePrecision] / N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-0.5625, \frac{{c}^{3} \cdot \left(a \cdot a\right)}{{b}^{5}}, \mathsf{fma}\left(-0.5, \frac{c}{b}, -0.375 \cdot \frac{a}{\frac{{b}^{3}}{c \cdot c}}\right)\right)
\end{array}
Initial program 14.6%
Taylor expanded in b around inf 98.3%
fma-def98.3%
*-commutative98.3%
unpow298.3%
fma-def98.3%
associate-/l*98.3%
unpow298.3%
Simplified98.3%
Final simplification98.3%
(FPCore (a b c) :precision binary64 (+ (* -0.5 (/ c b)) (/ (* a -0.375) (/ (pow b 3.0) (* c c)))))
double code(double a, double b, double c) {
return (-0.5 * (c / b)) + ((a * -0.375) / (pow(b, 3.0) / (c * c)));
}
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)) + ((a * (-0.375d0)) / ((b ** 3.0d0) / (c * c)))
end function
public static double code(double a, double b, double c) {
return (-0.5 * (c / b)) + ((a * -0.375) / (Math.pow(b, 3.0) / (c * c)));
}
def code(a, b, c): return (-0.5 * (c / b)) + ((a * -0.375) / (math.pow(b, 3.0) / (c * c)))
function code(a, b, c) return Float64(Float64(-0.5 * Float64(c / b)) + Float64(Float64(a * -0.375) / Float64((b ^ 3.0) / Float64(c * c)))) end
function tmp = code(a, b, c) tmp = (-0.5 * (c / b)) + ((a * -0.375) / ((b ^ 3.0) / (c * c))); end
code[a_, b_, c_] := N[(N[(-0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision] + N[(N[(a * -0.375), $MachinePrecision] / N[(N[Power[b, 3.0], $MachinePrecision] / N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
-0.5 \cdot \frac{c}{b} + \frac{a \cdot -0.375}{\frac{{b}^{3}}{c \cdot c}}
\end{array}
Initial program 14.6%
Taylor expanded in b around inf 97.0%
fma-def97.0%
associate-*r/97.0%
associate-*r*97.0%
unpow297.0%
Simplified97.0%
fma-udef97.0%
associate-/l*97.0%
*-commutative97.0%
Applied egg-rr97.0%
Final simplification97.0%
(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 14.6%
Taylor expanded in b around inf 92.8%
Final simplification92.8%
herbie shell --seed 2023291
(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)))