
(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 8 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
(/
(* -2.0 (/ (* a c) a))
(+
b
(sqrt
(/
(- (pow b 4.0) (* (pow (* a c) 2.0) 16.0))
(fma (* a c) 4.0 (* b b)))))))
double code(double a, double b, double c) {
return (-2.0 * ((a * c) / a)) / (b + sqrt(((pow(b, 4.0) - (pow((a * c), 2.0) * 16.0)) / fma((a * c), 4.0, (b * b)))));
}
function code(a, b, c) return Float64(Float64(-2.0 * Float64(Float64(a * c) / a)) / Float64(b + sqrt(Float64(Float64((b ^ 4.0) - Float64((Float64(a * c) ^ 2.0) * 16.0)) / fma(Float64(a * c), 4.0, Float64(b * b)))))) end
code[a_, b_, c_] := N[(N[(-2.0 * N[(N[(a * c), $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision] / N[(b + N[Sqrt[N[(N[(N[Power[b, 4.0], $MachinePrecision] - N[(N[Power[N[(a * c), $MachinePrecision], 2.0], $MachinePrecision] * 16.0), $MachinePrecision]), $MachinePrecision] / N[(N[(a * c), $MachinePrecision] * 4.0 + N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-2 \cdot \frac{a \cdot c}{a}}{b + \sqrt{\frac{{b}^{4} - {\left(a \cdot c\right)}^{2} \cdot 16}{\mathsf{fma}\left(a \cdot c, 4, b \cdot b\right)}}}
\end{array}
Initial program 53.9%
Simplified53.9%
*-commutative53.9%
metadata-eval53.9%
distribute-lft-neg-in53.9%
distribute-rgt-neg-in53.9%
*-commutative53.9%
fma-neg53.9%
flip--53.8%
div-sub53.8%
pow253.8%
pow253.8%
pow-prod-up53.5%
metadata-eval53.5%
fma-def53.8%
associate-*l*53.8%
pow253.8%
associate-*l*53.8%
fma-def53.8%
associate-*l*53.8%
Applied egg-rr53.8%
fma-def53.5%
+-commutative53.5%
*-commutative53.5%
fma-def53.5%
*-commutative53.5%
*-commutative53.5%
associate-*l*53.5%
fma-def53.5%
+-commutative53.5%
*-commutative53.5%
fma-def53.5%
Simplified53.5%
flip--53.3%
add-sqr-sqrt53.8%
sub-div53.7%
Applied egg-rr53.7%
Taylor expanded in b around 0 99.3%
*-commutative99.3%
Simplified99.3%
div-inv99.2%
associate-/l*99.2%
+-commutative99.2%
Applied egg-rr99.2%
*-commutative99.2%
associate-/r/99.2%
associate-*l/99.2%
associate-*r*99.2%
times-frac99.2%
*-lft-identity99.2%
associate-/r*99.4%
Simplified99.4%
Final simplification99.4%
(FPCore (a b c) :precision binary64 (/ (/ (* (* a c) -4.0) (+ b (sqrt (fma -4.0 (* a c) (* b b))))) (* a 2.0)))
double code(double a, double b, double c) {
return (((a * c) * -4.0) / (b + sqrt(fma(-4.0, (a * c), (b * b))))) / (a * 2.0);
}
function code(a, b, c) return Float64(Float64(Float64(Float64(a * c) * -4.0) / Float64(b + sqrt(fma(-4.0, Float64(a * c), Float64(b * b))))) / Float64(a * 2.0)) end
code[a_, b_, c_] := N[(N[(N[(N[(a * c), $MachinePrecision] * -4.0), $MachinePrecision] / N[(b + N[Sqrt[N[(-4.0 * N[(a * c), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{\left(a \cdot c\right) \cdot -4}{b + \sqrt{\mathsf{fma}\left(-4, a \cdot c, b \cdot b\right)}}}{a \cdot 2}
\end{array}
Initial program 53.9%
Simplified53.9%
*-commutative53.9%
metadata-eval53.9%
distribute-lft-neg-in53.9%
distribute-rgt-neg-in53.9%
*-commutative53.9%
fma-neg53.9%
flip--53.8%
div-sub53.8%
pow253.8%
pow253.8%
pow-prod-up53.5%
metadata-eval53.5%
fma-def53.8%
associate-*l*53.8%
pow253.8%
associate-*l*53.8%
fma-def53.8%
associate-*l*53.8%
Applied egg-rr53.8%
fma-def53.5%
+-commutative53.5%
*-commutative53.5%
fma-def53.5%
*-commutative53.5%
*-commutative53.5%
associate-*l*53.5%
fma-def53.5%
+-commutative53.5%
*-commutative53.5%
fma-def53.5%
Simplified53.5%
flip--53.3%
add-sqr-sqrt53.8%
sub-div53.7%
Applied egg-rr53.7%
Taylor expanded in b around 0 99.3%
*-commutative99.3%
Simplified99.3%
Taylor expanded in b around 0 99.3%
fma-def99.3%
unpow299.3%
Simplified99.3%
Final simplification99.3%
(FPCore (a b c) :precision binary64 (/ (/ (* (* a c) -4.0) (+ b (sqrt (fma b b (* a (* c -4.0)))))) (* a 2.0)))
double code(double a, double b, double c) {
return (((a * c) * -4.0) / (b + sqrt(fma(b, b, (a * (c * -4.0)))))) / (a * 2.0);
}
function code(a, b, c) return Float64(Float64(Float64(Float64(a * c) * -4.0) / Float64(b + sqrt(fma(b, b, Float64(a * Float64(c * -4.0)))))) / Float64(a * 2.0)) end
code[a_, b_, c_] := N[(N[(N[(N[(a * c), $MachinePrecision] * -4.0), $MachinePrecision] / N[(b + N[Sqrt[N[(b * b + N[(a * N[(c * -4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{\left(a \cdot c\right) \cdot -4}{b + \sqrt{\mathsf{fma}\left(b, b, a \cdot \left(c \cdot -4\right)\right)}}}{a \cdot 2}
\end{array}
Initial program 53.9%
Simplified53.9%
*-commutative53.9%
metadata-eval53.9%
distribute-lft-neg-in53.9%
distribute-rgt-neg-in53.9%
*-commutative53.9%
fma-neg53.9%
flip--53.8%
div-sub53.8%
pow253.8%
pow253.8%
pow-prod-up53.5%
metadata-eval53.5%
fma-def53.8%
associate-*l*53.8%
pow253.8%
associate-*l*53.8%
fma-def53.8%
associate-*l*53.8%
Applied egg-rr53.8%
fma-def53.5%
+-commutative53.5%
*-commutative53.5%
fma-def53.5%
*-commutative53.5%
*-commutative53.5%
associate-*l*53.5%
fma-def53.5%
+-commutative53.5%
*-commutative53.5%
fma-def53.5%
Simplified53.5%
flip--53.3%
add-sqr-sqrt53.8%
sub-div53.7%
Applied egg-rr53.7%
Taylor expanded in b around 0 99.3%
*-commutative99.3%
Simplified99.3%
Taylor expanded in b around 0 99.3%
+-commutative99.3%
unpow299.3%
fma-def99.3%
*-commutative99.3%
associate-*l*99.3%
Simplified99.3%
Final simplification99.3%
(FPCore (a b c) :precision binary64 (if (<= b 12.0) (/ (- (sqrt (fma b b (* c (* a -4.0)))) b) (* a 2.0)) (- (/ (- c) b) (* (/ a (* b (* b b))) (* c c)))))
double code(double a, double b, double c) {
double tmp;
if (b <= 12.0) {
tmp = (sqrt(fma(b, b, (c * (a * -4.0)))) - b) / (a * 2.0);
} else {
tmp = (-c / b) - ((a / (b * (b * b))) * (c * c));
}
return tmp;
}
function code(a, b, c) tmp = 0.0 if (b <= 12.0) tmp = Float64(Float64(sqrt(fma(b, b, Float64(c * Float64(a * -4.0)))) - b) / Float64(a * 2.0)); else tmp = Float64(Float64(Float64(-c) / b) - Float64(Float64(a / Float64(b * Float64(b * b))) * Float64(c * c))); end return tmp end
code[a_, b_, c_] := If[LessEqual[b, 12.0], 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[(N[(a / N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 12:\\
\;\;\;\;\frac{\sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -4\right)\right)} - b}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b} - \frac{a}{b \cdot \left(b \cdot b\right)} \cdot \left(c \cdot c\right)\\
\end{array}
\end{array}
if b < 12Initial program 79.4%
Simplified79.4%
if 12 < b Initial program 47.3%
Taylor expanded in b around inf 86.7%
mul-1-neg86.7%
unsub-neg86.7%
mul-1-neg86.7%
distribute-neg-frac86.7%
associate-/l*86.7%
associate-/r/86.7%
unpow286.7%
Simplified86.7%
unpow386.7%
Applied egg-rr86.7%
Final simplification85.2%
(FPCore (a b c) :precision binary64 (if (<= b 12.0) (/ (- (sqrt (- (* b b) (* (* a c) 4.0))) b) (* a 2.0)) (- (/ (- c) b) (* (/ a (* b (* b b))) (* c c)))))
double code(double a, double b, double c) {
double tmp;
if (b <= 12.0) {
tmp = (sqrt(((b * b) - ((a * c) * 4.0))) - b) / (a * 2.0);
} else {
tmp = (-c / b) - ((a / (b * (b * b))) * (c * c));
}
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 <= 12.0d0) then
tmp = (sqrt(((b * b) - ((a * c) * 4.0d0))) - b) / (a * 2.0d0)
else
tmp = (-c / b) - ((a / (b * (b * b))) * (c * c))
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= 12.0) {
tmp = (Math.sqrt(((b * b) - ((a * c) * 4.0))) - b) / (a * 2.0);
} else {
tmp = (-c / b) - ((a / (b * (b * b))) * (c * c));
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= 12.0: tmp = (math.sqrt(((b * b) - ((a * c) * 4.0))) - b) / (a * 2.0) else: tmp = (-c / b) - ((a / (b * (b * b))) * (c * c)) return tmp
function code(a, b, c) tmp = 0.0 if (b <= 12.0) tmp = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(Float64(a * c) * 4.0))) - b) / Float64(a * 2.0)); else tmp = Float64(Float64(Float64(-c) / b) - Float64(Float64(a / Float64(b * Float64(b * b))) * Float64(c * c))); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= 12.0) tmp = (sqrt(((b * b) - ((a * c) * 4.0))) - b) / (a * 2.0); else tmp = (-c / b) - ((a / (b * (b * b))) * (c * c)); end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, 12.0], N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(a * c), $MachinePrecision] * 4.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[(N[((-c) / b), $MachinePrecision] - N[(N[(a / N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 12:\\
\;\;\;\;\frac{\sqrt{b \cdot b - \left(a \cdot c\right) \cdot 4} - b}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b} - \frac{a}{b \cdot \left(b \cdot b\right)} \cdot \left(c \cdot c\right)\\
\end{array}
\end{array}
if b < 12Initial program 79.4%
Simplified79.4%
*-commutative79.4%
metadata-eval79.4%
distribute-lft-neg-in79.4%
distribute-rgt-neg-in79.4%
*-commutative79.4%
fma-neg79.4%
associate-*l*79.4%
Applied egg-rr79.4%
if 12 < b Initial program 47.3%
Taylor expanded in b around inf 86.7%
mul-1-neg86.7%
unsub-neg86.7%
mul-1-neg86.7%
distribute-neg-frac86.7%
associate-/l*86.7%
associate-/r/86.7%
unpow286.7%
Simplified86.7%
unpow386.7%
Applied egg-rr86.7%
Final simplification85.2%
(FPCore (a b c) :precision binary64 (- (/ (- c) b) (* (/ a (* b (* b b))) (* c c))))
double code(double a, double b, double c) {
return (-c / b) - ((a / (b * (b * b))) * (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 = (-c / b) - ((a / (b * (b * b))) * (c * c))
end function
public static double code(double a, double b, double c) {
return (-c / b) - ((a / (b * (b * b))) * (c * c));
}
def code(a, b, c): return (-c / b) - ((a / (b * (b * b))) * (c * c))
function code(a, b, c) return Float64(Float64(Float64(-c) / b) - Float64(Float64(a / Float64(b * Float64(b * b))) * Float64(c * c))) end
function tmp = code(a, b, c) tmp = (-c / b) - ((a / (b * (b * b))) * (c * c)); end
code[a_, b_, c_] := N[(N[((-c) / b), $MachinePrecision] - N[(N[(a / N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-c}{b} - \frac{a}{b \cdot \left(b \cdot b\right)} \cdot \left(c \cdot c\right)
\end{array}
Initial program 53.9%
Taylor expanded in b around inf 81.4%
mul-1-neg81.4%
unsub-neg81.4%
mul-1-neg81.4%
distribute-neg-frac81.4%
associate-/l*81.4%
associate-/r/81.4%
unpow281.4%
Simplified81.4%
unpow381.4%
Applied egg-rr81.4%
Final simplification81.4%
(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(Float64(-c) / 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 53.9%
Taylor expanded in b around inf 65.4%
mul-1-neg65.4%
distribute-neg-frac65.4%
Simplified65.4%
Final simplification65.4%
(FPCore (a b c) :precision binary64 (/ 0.0 a))
double code(double a, double b, double c) {
return 0.0 / a;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = 0.0d0 / a
end function
public static double code(double a, double b, double c) {
return 0.0 / a;
}
def code(a, b, c): return 0.0 / a
function code(a, b, c) return Float64(0.0 / a) end
function tmp = code(a, b, c) tmp = 0.0 / a; end
code[a_, b_, c_] := N[(0.0 / a), $MachinePrecision]
\begin{array}{l}
\\
\frac{0}{a}
\end{array}
Initial program 53.9%
add-sqr-sqrt53.9%
difference-of-squares53.9%
associate-*l*53.9%
sqrt-prod53.9%
metadata-eval53.9%
associate-*l*53.9%
sqrt-prod53.9%
metadata-eval53.9%
Applied egg-rr53.9%
*-commutative53.9%
cancel-sign-sub-inv53.9%
metadata-eval53.9%
Simplified53.9%
Taylor expanded in b around inf 3.2%
associate-*r/3.2%
distribute-rgt-out3.2%
metadata-eval3.2%
mul0-rgt3.2%
metadata-eval3.2%
Simplified3.2%
Final simplification3.2%
herbie shell --seed 2023285
(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)))