
(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 (/ (/ (* c a) (- a)) (+ b (sqrt (fma a (* c -3.0) (pow b 2.0))))))
double code(double a, double b, double c) {
return ((c * a) / -a) / (b + sqrt(fma(a, (c * -3.0), pow(b, 2.0))));
}
function code(a, b, c) return Float64(Float64(Float64(c * a) / Float64(-a)) / Float64(b + sqrt(fma(a, Float64(c * -3.0), (b ^ 2.0))))) end
code[a_, b_, c_] := N[(N[(N[(c * a), $MachinePrecision] / (-a)), $MachinePrecision] / N[(b + N[Sqrt[N[(a * N[(c * -3.0), $MachinePrecision] + N[Power[b, 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{c \cdot a}{-a}}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -3, {b}^{2}\right)}}
\end{array}
Initial program 56.2%
Taylor expanded in a around 0 56.2%
*-commutative56.2%
metadata-eval56.2%
distribute-rgt-neg-in56.2%
associate-*r*56.2%
distribute-rgt-neg-in56.2%
distribute-rgt-neg-in56.2%
metadata-eval56.2%
Simplified56.2%
flip-+56.0%
pow256.0%
add-sqr-sqrt57.8%
pow257.8%
pow257.8%
Applied egg-rr57.8%
unpow257.8%
sqr-neg57.8%
unpow257.8%
sub-neg57.8%
+-commutative57.8%
distribute-rgt-neg-in57.8%
distribute-rgt-neg-in57.8%
metadata-eval57.8%
*-commutative57.8%
fma-define57.8%
*-commutative57.8%
sub-neg57.8%
+-commutative57.8%
distribute-rgt-neg-in57.8%
distribute-rgt-neg-in57.8%
metadata-eval57.8%
*-commutative57.8%
fma-define57.8%
*-commutative57.8%
Simplified57.8%
Taylor expanded in b around 0 99.1%
*-commutative99.1%
*-commutative99.1%
Simplified99.1%
div-inv99.1%
associate-*l*99.2%
*-commutative99.2%
Applied egg-rr99.2%
*-commutative99.2%
times-frac99.3%
associate-*r/99.3%
*-lft-identity99.3%
associate-/r*99.5%
*-commutative99.5%
*-commutative99.5%
associate-*r*99.1%
*-commutative99.1%
times-frac99.4%
metadata-eval99.4%
*-commutative99.4%
Simplified99.4%
Final simplification99.4%
(FPCore (a b c) :precision binary64 (/ (/ (* (* c a) 3.0) (- (- b) (sqrt (+ (pow b 2.0) (* a (* c -3.0)))))) (* a 3.0)))
double code(double a, double b, double c) {
return (((c * a) * 3.0) / (-b - sqrt((pow(b, 2.0) + (a * (c * -3.0)))))) / (a * 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 = (((c * a) * 3.0d0) / (-b - sqrt(((b ** 2.0d0) + (a * (c * (-3.0d0))))))) / (a * 3.0d0)
end function
public static double code(double a, double b, double c) {
return (((c * a) * 3.0) / (-b - Math.sqrt((Math.pow(b, 2.0) + (a * (c * -3.0)))))) / (a * 3.0);
}
def code(a, b, c): return (((c * a) * 3.0) / (-b - math.sqrt((math.pow(b, 2.0) + (a * (c * -3.0)))))) / (a * 3.0)
function code(a, b, c) return Float64(Float64(Float64(Float64(c * a) * 3.0) / Float64(Float64(-b) - sqrt(Float64((b ^ 2.0) + Float64(a * Float64(c * -3.0)))))) / Float64(a * 3.0)) end
function tmp = code(a, b, c) tmp = (((c * a) * 3.0) / (-b - sqrt(((b ^ 2.0) + (a * (c * -3.0)))))) / (a * 3.0); end
code[a_, b_, c_] := N[(N[(N[(N[(c * a), $MachinePrecision] * 3.0), $MachinePrecision] / N[((-b) - N[Sqrt[N[(N[Power[b, 2.0], $MachinePrecision] + N[(a * N[(c * -3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 3.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{\left(c \cdot a\right) \cdot 3}{\left(-b\right) - \sqrt{{b}^{2} + a \cdot \left(c \cdot -3\right)}}}{a \cdot 3}
\end{array}
Initial program 56.2%
Taylor expanded in a around 0 56.2%
*-commutative56.2%
metadata-eval56.2%
distribute-rgt-neg-in56.2%
associate-*r*56.2%
distribute-rgt-neg-in56.2%
distribute-rgt-neg-in56.2%
metadata-eval56.2%
Simplified56.2%
flip-+56.0%
pow256.0%
add-sqr-sqrt57.8%
pow257.8%
pow257.8%
Applied egg-rr57.8%
unpow257.8%
sqr-neg57.8%
unpow257.8%
sub-neg57.8%
+-commutative57.8%
distribute-rgt-neg-in57.8%
distribute-rgt-neg-in57.8%
metadata-eval57.8%
*-commutative57.8%
fma-define57.8%
*-commutative57.8%
sub-neg57.8%
+-commutative57.8%
distribute-rgt-neg-in57.8%
distribute-rgt-neg-in57.8%
metadata-eval57.8%
*-commutative57.8%
fma-define57.8%
*-commutative57.8%
Simplified57.8%
Taylor expanded in b around 0 99.1%
*-commutative99.1%
*-commutative99.1%
Simplified99.1%
fma-undefine99.1%
Applied egg-rr99.1%
Final simplification99.1%
(FPCore (a b c) :precision binary64 (if (<= b 28.0) (/ (- (sqrt (fma b b (* a (* c -3.0)))) b) (* a 3.0)) (+ (* -0.5 (/ c b)) (* -0.375 (/ (* a (pow c 2.0)) (pow b 3.0))))))
double code(double a, double b, double c) {
double tmp;
if (b <= 28.0) {
tmp = (sqrt(fma(b, b, (a * (c * -3.0)))) - b) / (a * 3.0);
} else {
tmp = (-0.5 * (c / b)) + (-0.375 * ((a * pow(c, 2.0)) / pow(b, 3.0)));
}
return tmp;
}
function code(a, b, c) tmp = 0.0 if (b <= 28.0) tmp = Float64(Float64(sqrt(fma(b, b, Float64(a * Float64(c * -3.0)))) - b) / Float64(a * 3.0)); else tmp = Float64(Float64(-0.5 * Float64(c / b)) + Float64(-0.375 * Float64(Float64(a * (c ^ 2.0)) / (b ^ 3.0)))); end return tmp end
code[a_, b_, c_] := If[LessEqual[b, 28.0], N[(N[(N[Sqrt[N[(b * b + N[(a * N[(c * -3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 3.0), $MachinePrecision]), $MachinePrecision], N[(N[(-0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision] + N[(-0.375 * N[(N[(a * N[Power[c, 2.0], $MachinePrecision]), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 28:\\
\;\;\;\;\frac{\sqrt{\mathsf{fma}\left(b, b, a \cdot \left(c \cdot -3\right)\right)} - b}{a \cdot 3}\\
\mathbf{else}:\\
\;\;\;\;-0.5 \cdot \frac{c}{b} + -0.375 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}}\\
\end{array}
\end{array}
if b < 28Initial program 81.7%
/-rgt-identity81.7%
metadata-eval81.7%
Simplified81.9%
if 28 < b Initial program 47.7%
Taylor expanded in a around 0 88.1%
Final simplification86.6%
(FPCore (a b c) :precision binary64 (if (<= b 28.0) (/ (- (sqrt (fma b b (* a (* c -3.0)))) b) (* a 3.0)) (* c (- (* -0.375 (* a (/ c (pow b 3.0)))) (/ 0.5 b)))))
double code(double a, double b, double c) {
double tmp;
if (b <= 28.0) {
tmp = (sqrt(fma(b, b, (a * (c * -3.0)))) - b) / (a * 3.0);
} else {
tmp = c * ((-0.375 * (a * (c / pow(b, 3.0)))) - (0.5 / b));
}
return tmp;
}
function code(a, b, c) tmp = 0.0 if (b <= 28.0) tmp = Float64(Float64(sqrt(fma(b, b, Float64(a * Float64(c * -3.0)))) - b) / Float64(a * 3.0)); else tmp = Float64(c * Float64(Float64(-0.375 * Float64(a * Float64(c / (b ^ 3.0)))) - Float64(0.5 / b))); end return tmp end
code[a_, b_, c_] := If[LessEqual[b, 28.0], N[(N[(N[Sqrt[N[(b * b + N[(a * N[(c * -3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 3.0), $MachinePrecision]), $MachinePrecision], N[(c * N[(N[(-0.375 * N[(a * N[(c / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(0.5 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 28:\\
\;\;\;\;\frac{\sqrt{\mathsf{fma}\left(b, b, a \cdot \left(c \cdot -3\right)\right)} - b}{a \cdot 3}\\
\mathbf{else}:\\
\;\;\;\;c \cdot \left(-0.375 \cdot \left(a \cdot \frac{c}{{b}^{3}}\right) - \frac{0.5}{b}\right)\\
\end{array}
\end{array}
if b < 28Initial program 81.7%
/-rgt-identity81.7%
metadata-eval81.7%
Simplified81.9%
if 28 < b Initial program 47.7%
Taylor expanded in c around 0 87.8%
associate-*r/87.9%
Applied egg-rr87.9%
*-commutative87.9%
Simplified87.9%
Taylor expanded in c around 0 87.9%
associate-/l*87.9%
associate-*r/87.9%
metadata-eval87.9%
Simplified87.9%
Final simplification86.4%
(FPCore (a b c) :precision binary64 (if (<= b 28.0) (/ (- (sqrt (- (* b b) (* a (* c 3.0)))) b) (* a 3.0)) (* c (- (* -0.375 (* a (/ c (pow b 3.0)))) (/ 0.5 b)))))
double code(double a, double b, double c) {
double tmp;
if (b <= 28.0) {
tmp = (sqrt(((b * b) - (a * (c * 3.0)))) - b) / (a * 3.0);
} else {
tmp = c * ((-0.375 * (a * (c / pow(b, 3.0)))) - (0.5 / b));
}
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 <= 28.0d0) then
tmp = (sqrt(((b * b) - (a * (c * 3.0d0)))) - b) / (a * 3.0d0)
else
tmp = c * (((-0.375d0) * (a * (c / (b ** 3.0d0)))) - (0.5d0 / b))
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= 28.0) {
tmp = (Math.sqrt(((b * b) - (a * (c * 3.0)))) - b) / (a * 3.0);
} else {
tmp = c * ((-0.375 * (a * (c / Math.pow(b, 3.0)))) - (0.5 / b));
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= 28.0: tmp = (math.sqrt(((b * b) - (a * (c * 3.0)))) - b) / (a * 3.0) else: tmp = c * ((-0.375 * (a * (c / math.pow(b, 3.0)))) - (0.5 / b)) return tmp
function code(a, b, c) tmp = 0.0 if (b <= 28.0) tmp = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(a * Float64(c * 3.0)))) - b) / Float64(a * 3.0)); else tmp = Float64(c * Float64(Float64(-0.375 * Float64(a * Float64(c / (b ^ 3.0)))) - Float64(0.5 / b))); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= 28.0) tmp = (sqrt(((b * b) - (a * (c * 3.0)))) - b) / (a * 3.0); else tmp = c * ((-0.375 * (a * (c / (b ^ 3.0)))) - (0.5 / b)); end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, 28.0], N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(a * N[(c * 3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 3.0), $MachinePrecision]), $MachinePrecision], N[(c * N[(N[(-0.375 * N[(a * N[(c / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(0.5 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 28:\\
\;\;\;\;\frac{\sqrt{b \cdot b - a \cdot \left(c \cdot 3\right)} - b}{a \cdot 3}\\
\mathbf{else}:\\
\;\;\;\;c \cdot \left(-0.375 \cdot \left(a \cdot \frac{c}{{b}^{3}}\right) - \frac{0.5}{b}\right)\\
\end{array}
\end{array}
if b < 28Initial program 81.7%
Taylor expanded in a around 0 81.7%
*-commutative81.7%
metadata-eval81.7%
distribute-rgt-neg-in81.7%
associate-*r*81.8%
distribute-rgt-neg-in81.8%
distribute-rgt-neg-in81.8%
metadata-eval81.8%
Simplified81.8%
if 28 < b Initial program 47.7%
Taylor expanded in c around 0 87.8%
associate-*r/87.9%
Applied egg-rr87.9%
*-commutative87.9%
Simplified87.9%
Taylor expanded in c around 0 87.9%
associate-/l*87.9%
associate-*r/87.9%
metadata-eval87.9%
Simplified87.9%
Final simplification86.4%
(FPCore (a b c) :precision binary64 (* c (- (* -0.375 (* a (/ c (pow b 3.0)))) (/ 0.5 b))))
double code(double a, double b, double c) {
return c * ((-0.375 * (a * (c / pow(b, 3.0)))) - (0.5 / 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 * (((-0.375d0) * (a * (c / (b ** 3.0d0)))) - (0.5d0 / b))
end function
public static double code(double a, double b, double c) {
return c * ((-0.375 * (a * (c / Math.pow(b, 3.0)))) - (0.5 / b));
}
def code(a, b, c): return c * ((-0.375 * (a * (c / math.pow(b, 3.0)))) - (0.5 / b))
function code(a, b, c) return Float64(c * Float64(Float64(-0.375 * Float64(a * Float64(c / (b ^ 3.0)))) - Float64(0.5 / b))) end
function tmp = code(a, b, c) tmp = c * ((-0.375 * (a * (c / (b ^ 3.0)))) - (0.5 / b)); end
code[a_, b_, c_] := N[(c * N[(N[(-0.375 * N[(a * N[(c / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(0.5 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
c \cdot \left(-0.375 \cdot \left(a \cdot \frac{c}{{b}^{3}}\right) - \frac{0.5}{b}\right)
\end{array}
Initial program 56.2%
Taylor expanded in c around 0 80.6%
associate-*r/80.7%
Applied egg-rr80.7%
*-commutative80.7%
Simplified80.7%
Taylor expanded in c around 0 80.8%
associate-/l*80.8%
associate-*r/80.8%
metadata-eval80.8%
Simplified80.8%
(FPCore (a b c) :precision binary64 (/ (* c -0.5) b))
double code(double a, double b, double c) {
return (c * -0.5) / 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 * (-0.5d0)) / b
end function
public static double code(double a, double b, double c) {
return (c * -0.5) / b;
}
def code(a, b, c): return (c * -0.5) / b
function code(a, b, c) return Float64(Float64(c * -0.5) / b) end
function tmp = code(a, b, c) tmp = (c * -0.5) / b; end
code[a_, b_, c_] := N[(N[(c * -0.5), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{c \cdot -0.5}{b}
\end{array}
Initial program 56.2%
Taylor expanded in b around inf 63.7%
associate-*r/63.7%
*-commutative63.7%
Simplified63.7%
herbie shell --seed 2024090
(FPCore (a b c)
:name "Cubic critical, 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) (* (* 3.0 a) c)))) (* 3.0 a)))