
(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 6 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 (let* ((t_0 (* (* a c) -4.0))) (/ (/ t_0 (+ b (sqrt (fma b b t_0)))) (* a 2.0))))
double code(double a, double b, double c) {
double t_0 = (a * c) * -4.0;
return (t_0 / (b + sqrt(fma(b, b, t_0)))) / (a * 2.0);
}
function code(a, b, c) t_0 = Float64(Float64(a * c) * -4.0) return Float64(Float64(t_0 / Float64(b + sqrt(fma(b, b, t_0)))) / Float64(a * 2.0)) end
code[a_, b_, c_] := Block[{t$95$0 = N[(N[(a * c), $MachinePrecision] * -4.0), $MachinePrecision]}, N[(N[(t$95$0 / N[(b + N[Sqrt[N[(b * b + t$95$0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(a \cdot c\right) \cdot -4\\
\frac{\frac{t\_0}{b + \sqrt{\mathsf{fma}\left(b, b, t\_0\right)}}}{a \cdot 2}
\end{array}
\end{array}
Initial program 57.8%
*-commutative57.8%
Simplified57.8%
expm1-log1p-u57.7%
expm1-undefine55.1%
associate-*l*55.1%
Applied egg-rr55.1%
expm1-define57.7%
associate-*r*57.7%
*-commutative57.7%
Simplified57.7%
+-commutative57.7%
flip-+57.4%
add-sqr-sqrt58.9%
pow258.9%
expm1-log1p-u59.0%
associate-*l*59.0%
sqr-neg59.0%
pow259.0%
add-sqr-sqrt0.0%
sqrt-unprod1.4%
sqr-neg1.4%
sqrt-prod1.6%
add-sqr-sqrt1.4%
unsub-neg1.4%
Applied egg-rr59.0%
sub-neg59.0%
+-commutative59.0%
neg-sub059.0%
associate--r-59.0%
associate-+l-99.4%
+-inverses99.4%
+-lft-identity99.4%
neg-sub099.4%
*-commutative99.4%
associate-*r*99.4%
distribute-rgt-neg-in99.4%
metadata-eval99.4%
unpow299.4%
fma-neg99.4%
*-commutative99.4%
Simplified99.4%
(FPCore (a b c) :precision binary64 (if (<= b 90.0) (/ (- (sqrt (fma b b (* c (* a -4.0)))) b) (* a 2.0)) (- (/ c (- b)) (* a (/ (pow c 2.0) (pow b 3.0))))))
double code(double a, double b, double c) {
double tmp;
if (b <= 90.0) {
tmp = (sqrt(fma(b, b, (c * (a * -4.0)))) - b) / (a * 2.0);
} else {
tmp = (c / -b) - (a * (pow(c, 2.0) / pow(b, 3.0)));
}
return tmp;
}
function code(a, b, c) tmp = 0.0 if (b <= 90.0) tmp = Float64(Float64(sqrt(fma(b, b, Float64(c * Float64(a * -4.0)))) - b) / Float64(a * 2.0)); else tmp = Float64(Float64(c / Float64(-b)) - Float64(a * Float64((c ^ 2.0) / (b ^ 3.0)))); end return tmp end
code[a_, b_, c_] := If[LessEqual[b, 90.0], N[(N[(N[Sqrt[N[(b * b + N[(c * N[(a * -4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[(N[(c / (-b)), $MachinePrecision] - N[(a * N[(N[Power[c, 2.0], $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 90:\\
\;\;\;\;\frac{\sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -4\right)\right)} - b}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{-b} - a \cdot \frac{{c}^{2}}{{b}^{3}}\\
\end{array}
\end{array}
if b < 90Initial program 81.2%
*-commutative81.2%
+-commutative81.2%
sqr-neg81.2%
unsub-neg81.2%
sqr-neg81.2%
fma-neg81.2%
distribute-lft-neg-in81.2%
*-commutative81.2%
*-commutative81.2%
distribute-rgt-neg-in81.2%
metadata-eval81.2%
Simplified81.2%
if 90 < b Initial program 47.6%
*-commutative47.6%
Simplified47.6%
Taylor expanded in a around 0 89.2%
mul-1-neg89.2%
unsub-neg89.2%
mul-1-neg89.2%
distribute-neg-frac289.2%
associate-/l*89.2%
Simplified89.2%
(FPCore (a b c) :precision binary64 (if (<= b 90.0) (/ (- (sqrt (- (* b b) (* c (* a 4.0)))) b) (* a 2.0)) (- (/ c (- b)) (* a (/ (pow c 2.0) (pow b 3.0))))))
double code(double a, double b, double c) {
double tmp;
if (b <= 90.0) {
tmp = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
} else {
tmp = (c / -b) - (a * (pow(c, 2.0) / pow(b, 3.0)));
}
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 <= 90.0d0) then
tmp = (sqrt(((b * b) - (c * (a * 4.0d0)))) - b) / (a * 2.0d0)
else
tmp = (c / -b) - (a * ((c ** 2.0d0) / (b ** 3.0d0)))
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= 90.0) {
tmp = (Math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
} else {
tmp = (c / -b) - (a * (Math.pow(c, 2.0) / Math.pow(b, 3.0)));
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= 90.0: tmp = (math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0) else: tmp = (c / -b) - (a * (math.pow(c, 2.0) / math.pow(b, 3.0))) return tmp
function code(a, b, c) tmp = 0.0 if (b <= 90.0) tmp = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 4.0)))) - b) / Float64(a * 2.0)); else tmp = Float64(Float64(c / Float64(-b)) - Float64(a * Float64((c ^ 2.0) / (b ^ 3.0)))); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= 90.0) tmp = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0); else tmp = (c / -b) - (a * ((c ^ 2.0) / (b ^ 3.0))); end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, 90.0], N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(a * 4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[(N[(c / (-b)), $MachinePrecision] - N[(a * N[(N[Power[c, 2.0], $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 90:\\
\;\;\;\;\frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{-b} - a \cdot \frac{{c}^{2}}{{b}^{3}}\\
\end{array}
\end{array}
if b < 90Initial program 81.2%
if 90 < b Initial program 47.6%
*-commutative47.6%
Simplified47.6%
Taylor expanded in a around 0 89.2%
mul-1-neg89.2%
unsub-neg89.2%
mul-1-neg89.2%
distribute-neg-frac289.2%
associate-/l*89.2%
Simplified89.2%
Final simplification86.8%
(FPCore (a b c) :precision binary64 (if (<= b 90.0) (/ (- (sqrt (- (* b b) (* c (* a 4.0)))) b) (* a 2.0)) (* c (- (/ -1.0 b) (* a (/ c (pow b 3.0)))))))
double code(double a, double b, double c) {
double tmp;
if (b <= 90.0) {
tmp = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
} else {
tmp = c * ((-1.0 / b) - (a * (c / pow(b, 3.0))));
}
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 <= 90.0d0) then
tmp = (sqrt(((b * b) - (c * (a * 4.0d0)))) - b) / (a * 2.0d0)
else
tmp = c * (((-1.0d0) / b) - (a * (c / (b ** 3.0d0))))
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= 90.0) {
tmp = (Math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
} else {
tmp = c * ((-1.0 / b) - (a * (c / Math.pow(b, 3.0))));
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= 90.0: tmp = (math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0) else: tmp = c * ((-1.0 / b) - (a * (c / math.pow(b, 3.0)))) return tmp
function code(a, b, c) tmp = 0.0 if (b <= 90.0) tmp = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 4.0)))) - b) / Float64(a * 2.0)); else tmp = Float64(c * Float64(Float64(-1.0 / b) - Float64(a * Float64(c / (b ^ 3.0))))); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= 90.0) tmp = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0); else tmp = c * ((-1.0 / b) - (a * (c / (b ^ 3.0)))); end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, 90.0], N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(a * 4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[(c * N[(N[(-1.0 / b), $MachinePrecision] - N[(a * N[(c / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 90:\\
\;\;\;\;\frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;c \cdot \left(\frac{-1}{b} - a \cdot \frac{c}{{b}^{3}}\right)\\
\end{array}
\end{array}
if b < 90Initial program 81.2%
if 90 < b Initial program 47.6%
*-commutative47.6%
Simplified47.6%
Taylor expanded in a around inf 47.5%
Taylor expanded in b around inf 89.0%
distribute-lft-out89.0%
associate-/l*89.0%
fma-define89.1%
unpow289.1%
unpow289.1%
swap-sqr89.1%
unpow289.1%
Simplified89.1%
Taylor expanded in c around 0 89.1%
sub-neg89.1%
mul-1-neg89.1%
associate-/l*89.1%
distribute-rgt-neg-in89.1%
mul-1-neg89.1%
distribute-neg-frac89.1%
metadata-eval89.1%
+-commutative89.1%
mul-1-neg89.1%
distribute-rgt-neg-in89.1%
associate-/l*89.1%
unsub-neg89.1%
associate-/l*89.1%
Simplified89.1%
Final simplification86.7%
(FPCore (a b c) :precision binary64 (* c (- (/ -1.0 b) (* a (/ c (pow b 3.0))))))
double code(double a, double b, double c) {
return c * ((-1.0 / b) - (a * (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 = c * (((-1.0d0) / b) - (a * (c / (b ** 3.0d0))))
end function
public static double code(double a, double b, double c) {
return c * ((-1.0 / b) - (a * (c / Math.pow(b, 3.0))));
}
def code(a, b, c): return c * ((-1.0 / b) - (a * (c / math.pow(b, 3.0))))
function code(a, b, c) return Float64(c * Float64(Float64(-1.0 / b) - Float64(a * Float64(c / (b ^ 3.0))))) end
function tmp = code(a, b, c) tmp = c * ((-1.0 / b) - (a * (c / (b ^ 3.0)))); end
code[a_, b_, c_] := N[(c * N[(N[(-1.0 / b), $MachinePrecision] - N[(a * N[(c / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
c \cdot \left(\frac{-1}{b} - a \cdot \frac{c}{{b}^{3}}\right)
\end{array}
Initial program 57.8%
*-commutative57.8%
Simplified57.8%
Taylor expanded in a around inf 57.5%
Taylor expanded in b around inf 80.4%
distribute-lft-out80.4%
associate-/l*80.4%
fma-define80.5%
unpow280.5%
unpow280.5%
swap-sqr80.5%
unpow280.5%
Simplified80.5%
Taylor expanded in c around 0 80.5%
sub-neg80.5%
mul-1-neg80.5%
associate-/l*80.5%
distribute-rgt-neg-in80.5%
mul-1-neg80.5%
distribute-neg-frac80.5%
metadata-eval80.5%
+-commutative80.5%
mul-1-neg80.5%
distribute-rgt-neg-in80.5%
associate-/l*80.5%
unsub-neg80.5%
associate-/l*80.5%
Simplified80.5%
(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(c / Float64(-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 57.8%
*-commutative57.8%
Simplified57.8%
Taylor expanded in b around inf 63.1%
associate-*r/63.1%
mul-1-neg63.1%
Simplified63.1%
Final simplification63.1%
herbie shell --seed 2024111
(FPCore (a b c)
:name "Quadratic roots, 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) (* (* 4.0 a) c)))) (* 2.0 a)))