
(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 8 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 c (* a 3.0) 0.0) (* (* a (- 3.0)) (+ b (sqrt (- (pow b 2.0) (* c (* a 3.0))))))))
double code(double a, double b, double c) {
return fma(c, (a * 3.0), 0.0) / ((a * -3.0) * (b + sqrt((pow(b, 2.0) - (c * (a * 3.0))))));
}
function code(a, b, c) return Float64(fma(c, Float64(a * 3.0), 0.0) / Float64(Float64(a * Float64(-3.0)) * Float64(b + sqrt(Float64((b ^ 2.0) - Float64(c * Float64(a * 3.0))))))) end
code[a_, b_, c_] := N[(N[(c * N[(a * 3.0), $MachinePrecision] + 0.0), $MachinePrecision] / N[(N[(a * (-3.0)), $MachinePrecision] * N[(b + N[Sqrt[N[(N[Power[b, 2.0], $MachinePrecision] - N[(c * N[(a * 3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(c, a \cdot 3, 0\right)}{\left(a \cdot \left(-3\right)\right) \cdot \left(b + \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}\right)}
\end{array}
Initial program 57.0%
expm1-log1p-u56.9%
expm1-undefine55.2%
Applied egg-rr55.2%
flip-+54.8%
pow254.8%
add-sqr-sqrt56.2%
pow256.2%
expm1-define57.7%
expm1-log1p-u57.7%
*-commutative57.7%
pow257.7%
expm1-define58.2%
expm1-log1p-u58.2%
*-commutative58.2%
Applied egg-rr58.2%
associate--r-99.3%
unpow299.1%
sqr-neg99.1%
unpow299.3%
*-commutative99.3%
*-commutative99.3%
Simplified99.3%
*-un-lft-identity99.3%
associate-/l/99.3%
+-commutative99.3%
*-commutative99.3%
fma-define99.3%
*-commutative99.3%
+-inverses99.3%
*-commutative99.3%
Applied egg-rr99.3%
Final simplification99.3%
(FPCore (a b c) :precision binary64 (/ (/ (* c (* a (- 3.0))) (+ b (sqrt (- (pow b 2.0) (* c (* a 3.0)))))) (* a 3.0)))
double code(double a, double b, double c) {
return ((c * (a * -3.0)) / (b + sqrt((pow(b, 2.0) - (c * (a * 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) - (c * (a * 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) - (c * (a * 3.0)))))) / (a * 3.0);
}
def code(a, b, c): return ((c * (a * -3.0)) / (b + math.sqrt((math.pow(b, 2.0) - (c * (a * 3.0)))))) / (a * 3.0)
function code(a, b, c) return Float64(Float64(Float64(c * Float64(a * Float64(-3.0))) / Float64(b + sqrt(Float64((b ^ 2.0) - Float64(c * Float64(a * 3.0)))))) / Float64(a * 3.0)) end
function tmp = code(a, b, c) tmp = ((c * (a * -3.0)) / (b + sqrt(((b ^ 2.0) - (c * (a * 3.0)))))) / (a * 3.0); end
code[a_, b_, c_] := N[(N[(N[(c * N[(a * (-3.0)), $MachinePrecision]), $MachinePrecision] / N[(b + N[Sqrt[N[(N[Power[b, 2.0], $MachinePrecision] - N[(c * N[(a * 3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 3.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{c \cdot \left(a \cdot \left(-3\right)\right)}{b + \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}{a \cdot 3}
\end{array}
Initial program 57.0%
expm1-log1p-u56.9%
expm1-undefine55.2%
Applied egg-rr55.2%
flip-+54.8%
pow254.8%
add-sqr-sqrt56.2%
pow256.2%
expm1-define57.7%
expm1-log1p-u57.7%
*-commutative57.7%
pow257.7%
expm1-define58.2%
expm1-log1p-u58.2%
*-commutative58.2%
Applied egg-rr58.2%
associate--r-99.3%
unpow299.1%
sqr-neg99.1%
unpow299.3%
*-commutative99.3%
*-commutative99.3%
Simplified99.3%
Taylor expanded in b around 0 99.3%
Final simplification99.3%
(FPCore (a b c) :precision binary64 (if (<= b 250.0) (/ (- (sqrt (fma b b (* a (* c -3.0)))) b) (* a 3.0)) (/ (fma -0.5 c (* -0.375 (* a (pow (/ c b) 2.0)))) b)))
double code(double a, double b, double c) {
double tmp;
if (b <= 250.0) {
tmp = (sqrt(fma(b, b, (a * (c * -3.0)))) - b) / (a * 3.0);
} else {
tmp = fma(-0.5, c, (-0.375 * (a * pow((c / b), 2.0)))) / b;
}
return tmp;
}
function code(a, b, c) tmp = 0.0 if (b <= 250.0) tmp = Float64(Float64(sqrt(fma(b, b, Float64(a * Float64(c * -3.0)))) - b) / Float64(a * 3.0)); else tmp = Float64(fma(-0.5, c, Float64(-0.375 * Float64(a * (Float64(c / b) ^ 2.0)))) / b); end return tmp end
code[a_, b_, c_] := If[LessEqual[b, 250.0], 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 * c + N[(-0.375 * N[(a * N[Power[N[(c / b), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 250:\\
\;\;\;\;\frac{\sqrt{\mathsf{fma}\left(b, b, a \cdot \left(c \cdot -3\right)\right)} - b}{a \cdot 3}\\
\mathbf{else}:\\
\;\;\;\;\frac{\mathsf{fma}\left(-0.5, c, -0.375 \cdot \left(a \cdot {\left(\frac{c}{b}\right)}^{2}\right)\right)}{b}\\
\end{array}
\end{array}
if b < 250Initial program 78.2%
Simplified78.3%
if 250 < b Initial program 42.9%
Taylor expanded in c around 0 88.4%
Taylor expanded in c around inf 88.3%
Taylor expanded in b around inf 88.9%
fma-define88.9%
associate-/l*88.9%
unpow288.9%
unpow288.9%
times-frac88.9%
unpow288.9%
Simplified88.9%
Final simplification84.7%
(FPCore (a b c) :precision binary64 (if (<= b 250.0) (/ (- (sqrt (- (* b b) (* c (* a 3.0)))) b) (* a 3.0)) (/ (fma -0.5 c (* -0.375 (* a (pow (/ c b) 2.0)))) b)))
double code(double a, double b, double c) {
double tmp;
if (b <= 250.0) {
tmp = (sqrt(((b * b) - (c * (a * 3.0)))) - b) / (a * 3.0);
} else {
tmp = fma(-0.5, c, (-0.375 * (a * pow((c / b), 2.0)))) / b;
}
return tmp;
}
function code(a, b, c) tmp = 0.0 if (b <= 250.0) tmp = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 3.0)))) - b) / Float64(a * 3.0)); else tmp = Float64(fma(-0.5, c, Float64(-0.375 * Float64(a * (Float64(c / b) ^ 2.0)))) / b); end return tmp end
code[a_, b_, c_] := If[LessEqual[b, 250.0], N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(a * 3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 3.0), $MachinePrecision]), $MachinePrecision], N[(N[(-0.5 * c + N[(-0.375 * N[(a * N[Power[N[(c / b), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 250:\\
\;\;\;\;\frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 3\right)} - b}{a \cdot 3}\\
\mathbf{else}:\\
\;\;\;\;\frac{\mathsf{fma}\left(-0.5, c, -0.375 \cdot \left(a \cdot {\left(\frac{c}{b}\right)}^{2}\right)\right)}{b}\\
\end{array}
\end{array}
if b < 250Initial program 78.2%
if 250 < b Initial program 42.9%
Taylor expanded in c around 0 88.4%
Taylor expanded in c around inf 88.3%
Taylor expanded in b around inf 88.9%
fma-define88.9%
associate-/l*88.9%
unpow288.9%
unpow288.9%
times-frac88.9%
unpow288.9%
Simplified88.9%
Final simplification84.6%
(FPCore (a b c) :precision binary64 (if (<= b 250.0) (/ (- (sqrt (- (* b b) (* c (* a 3.0)))) b) (* a 3.0)) (* c (+ (/ (* -0.375 (* c a)) (pow b 3.0)) (/ -0.5 b)))))
double code(double a, double b, double c) {
double tmp;
if (b <= 250.0) {
tmp = (sqrt(((b * b) - (c * (a * 3.0)))) - b) / (a * 3.0);
} else {
tmp = c * (((-0.375 * (c * a)) / 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 <= 250.0d0) then
tmp = (sqrt(((b * b) - (c * (a * 3.0d0)))) - b) / (a * 3.0d0)
else
tmp = c * ((((-0.375d0) * (c * a)) / (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 <= 250.0) {
tmp = (Math.sqrt(((b * b) - (c * (a * 3.0)))) - b) / (a * 3.0);
} else {
tmp = c * (((-0.375 * (c * a)) / Math.pow(b, 3.0)) + (-0.5 / b));
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= 250.0: tmp = (math.sqrt(((b * b) - (c * (a * 3.0)))) - b) / (a * 3.0) else: tmp = c * (((-0.375 * (c * a)) / math.pow(b, 3.0)) + (-0.5 / b)) return tmp
function code(a, b, c) tmp = 0.0 if (b <= 250.0) tmp = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 3.0)))) - b) / Float64(a * 3.0)); else tmp = Float64(c * Float64(Float64(Float64(-0.375 * Float64(c * a)) / (b ^ 3.0)) + Float64(-0.5 / b))); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= 250.0) tmp = (sqrt(((b * b) - (c * (a * 3.0)))) - b) / (a * 3.0); else tmp = c * (((-0.375 * (c * a)) / (b ^ 3.0)) + (-0.5 / b)); end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, 250.0], N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(a * 3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 3.0), $MachinePrecision]), $MachinePrecision], N[(c * N[(N[(N[(-0.375 * N[(c * a), $MachinePrecision]), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision] + N[(-0.5 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 250:\\
\;\;\;\;\frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 3\right)} - b}{a \cdot 3}\\
\mathbf{else}:\\
\;\;\;\;c \cdot \left(\frac{-0.375 \cdot \left(c \cdot a\right)}{{b}^{3}} + \frac{-0.5}{b}\right)\\
\end{array}
\end{array}
if b < 250Initial program 78.2%
if 250 < b Initial program 42.9%
Taylor expanded in c around 0 88.4%
Taylor expanded in c around inf 88.3%
Taylor expanded in c around 0 88.7%
cancel-sign-sub-inv88.7%
associate-*r/88.7%
metadata-eval88.7%
associate-*r/88.7%
metadata-eval88.7%
Simplified88.7%
Final simplification84.5%
(FPCore (a b c) :precision binary64 (* c (+ (/ (* -0.375 (* c a)) (pow b 3.0)) (/ -0.5 b))))
double code(double a, double b, double c) {
return c * (((-0.375 * (c * a)) / 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) * (c * a)) / (b ** 3.0d0)) + ((-0.5d0) / b))
end function
public static double code(double a, double b, double c) {
return c * (((-0.375 * (c * a)) / Math.pow(b, 3.0)) + (-0.5 / b));
}
def code(a, b, c): return c * (((-0.375 * (c * a)) / math.pow(b, 3.0)) + (-0.5 / b))
function code(a, b, c) return Float64(c * Float64(Float64(Float64(-0.375 * Float64(c * a)) / (b ^ 3.0)) + Float64(-0.5 / b))) end
function tmp = code(a, b, c) tmp = c * (((-0.375 * (c * a)) / (b ^ 3.0)) + (-0.5 / b)); end
code[a_, b_, c_] := N[(c * N[(N[(N[(-0.375 * N[(c * a), $MachinePrecision]), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision] + N[(-0.5 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
c \cdot \left(\frac{-0.375 \cdot \left(c \cdot a\right)}{{b}^{3}} + \frac{-0.5}{b}\right)
\end{array}
Initial program 57.0%
Taylor expanded in c around 0 78.5%
Taylor expanded in c around inf 78.4%
Taylor expanded in c around 0 78.7%
cancel-sign-sub-inv78.7%
associate-*r/78.7%
metadata-eval78.7%
associate-*r/78.7%
metadata-eval78.7%
Simplified78.7%
Final simplification78.7%
(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 57.0%
Taylor expanded in b around inf 62.9%
associate-*r/62.9%
*-commutative62.9%
Simplified62.9%
(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(c * Float64(-0.5 / b)) end
function tmp = code(a, b, c) tmp = c * (-0.5 / b); end
code[a_, b_, c_] := N[(c * N[(-0.5 / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
c \cdot \frac{-0.5}{b}
\end{array}
Initial program 57.0%
Taylor expanded in b around inf 62.9%
associate-*r/62.9%
*-commutative62.9%
Simplified62.9%
Taylor expanded in c around 0 62.9%
associate-*r/62.9%
*-commutative62.9%
associate-*r/62.8%
Simplified62.8%
herbie shell --seed 2024131
(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)))