
(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 10 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 (fma (fma (/ (- c) (* b b)) (/ c b) (* (* (* (fma -2.0 (* b b) (* (* c a) -5.0)) (pow c 3.0)) (pow b -7.0)) a)) a (/ (- c) b)))
double code(double a, double b, double c) {
return fma(fma((-c / (b * b)), (c / b), (((fma(-2.0, (b * b), ((c * a) * -5.0)) * pow(c, 3.0)) * pow(b, -7.0)) * a)), a, (-c / b));
}
function code(a, b, c) return fma(fma(Float64(Float64(-c) / Float64(b * b)), Float64(c / b), Float64(Float64(Float64(fma(-2.0, Float64(b * b), Float64(Float64(c * a) * -5.0)) * (c ^ 3.0)) * (b ^ -7.0)) * a)), a, Float64(Float64(-c) / b)) end
code[a_, b_, c_] := N[(N[(N[((-c) / N[(b * b), $MachinePrecision]), $MachinePrecision] * N[(c / b), $MachinePrecision] + N[(N[(N[(N[(-2.0 * N[(b * b), $MachinePrecision] + N[(N[(c * a), $MachinePrecision] * -5.0), $MachinePrecision]), $MachinePrecision] * N[Power[c, 3.0], $MachinePrecision]), $MachinePrecision] * N[Power[b, -7.0], $MachinePrecision]), $MachinePrecision] * a), $MachinePrecision]), $MachinePrecision] * a + N[((-c) / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\mathsf{fma}\left(\frac{-c}{b \cdot b}, \frac{c}{b}, \left(\left(\mathsf{fma}\left(-2, b \cdot b, \left(c \cdot a\right) \cdot -5\right) \cdot {c}^{3}\right) \cdot {b}^{-7}\right) \cdot a\right), a, \frac{-c}{b}\right)
\end{array}
Initial program 33.4%
Taylor expanded in a around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
Applied rewrites95.0%
Taylor expanded in b around 0
Applied rewrites95.0%
Taylor expanded in c around 0
Applied rewrites95.0%
Applied rewrites95.0%
Final simplification95.0%
(FPCore (a b c) :precision binary64 (/ (- (/ (* (* (* (* c c) (* c a)) a) -2.0) (pow b 4.0)) (fma (/ c b) (/ (* c a) b) c)) b))
double code(double a, double b, double c) {
return ((((((c * c) * (c * a)) * a) * -2.0) / pow(b, 4.0)) - fma((c / b), ((c * a) / b), c)) / b;
}
function code(a, b, c) return Float64(Float64(Float64(Float64(Float64(Float64(Float64(c * c) * Float64(c * a)) * a) * -2.0) / (b ^ 4.0)) - fma(Float64(c / b), Float64(Float64(c * a) / b), c)) / b) end
code[a_, b_, c_] := N[(N[(N[(N[(N[(N[(N[(c * c), $MachinePrecision] * N[(c * a), $MachinePrecision]), $MachinePrecision] * a), $MachinePrecision] * -2.0), $MachinePrecision] / N[Power[b, 4.0], $MachinePrecision]), $MachinePrecision] - N[(N[(c / b), $MachinePrecision] * N[(N[(c * a), $MachinePrecision] / b), $MachinePrecision] + c), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{\left(\left(\left(c \cdot c\right) \cdot \left(c \cdot a\right)\right) \cdot a\right) \cdot -2}{{b}^{4}} - \mathsf{fma}\left(\frac{c}{b}, \frac{c \cdot a}{b}, c\right)}{b}
\end{array}
Initial program 33.4%
Taylor expanded in b around inf
lower-/.f64N/A
Applied rewrites93.3%
Applied rewrites93.3%
Final simplification93.3%
(FPCore (a b c) :precision binary64 (/ (* (fma (- (/ (* (* (* a a) c) -2.0) (pow b 4.0)) (/ a (* b b))) c -1.0) c) b))
double code(double a, double b, double c) {
return (fma((((((a * a) * c) * -2.0) / pow(b, 4.0)) - (a / (b * b))), c, -1.0) * c) / b;
}
function code(a, b, c) return Float64(Float64(fma(Float64(Float64(Float64(Float64(Float64(a * a) * c) * -2.0) / (b ^ 4.0)) - Float64(a / Float64(b * b))), c, -1.0) * c) / b) end
code[a_, b_, c_] := N[(N[(N[(N[(N[(N[(N[(N[(a * a), $MachinePrecision] * c), $MachinePrecision] * -2.0), $MachinePrecision] / N[Power[b, 4.0], $MachinePrecision]), $MachinePrecision] - N[(a / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * c + -1.0), $MachinePrecision] * c), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\frac{\left(\left(a \cdot a\right) \cdot c\right) \cdot -2}{{b}^{4}} - \frac{a}{b \cdot b}, c, -1\right) \cdot c}{b}
\end{array}
Initial program 33.4%
Taylor expanded in b around inf
lower-/.f64N/A
Applied rewrites93.3%
Taylor expanded in c around 0
Applied rewrites93.2%
Final simplification93.2%
(FPCore (a b c) :precision binary64 (* (fma (/ (fma (* (* a a) -2.0) c (* (* (- b) b) a)) (pow b 5.0)) c (/ -1.0 b)) c))
double code(double a, double b, double c) {
return fma((fma(((a * a) * -2.0), c, ((-b * b) * a)) / pow(b, 5.0)), c, (-1.0 / b)) * c;
}
function code(a, b, c) return Float64(fma(Float64(fma(Float64(Float64(a * a) * -2.0), c, Float64(Float64(Float64(-b) * b) * a)) / (b ^ 5.0)), c, Float64(-1.0 / b)) * c) end
code[a_, b_, c_] := N[(N[(N[(N[(N[(N[(a * a), $MachinePrecision] * -2.0), $MachinePrecision] * c + N[(N[((-b) * b), $MachinePrecision] * a), $MachinePrecision]), $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision] * c + N[(-1.0 / b), $MachinePrecision]), $MachinePrecision] * c), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -2, c, \left(\left(-b\right) \cdot b\right) \cdot a\right)}{{b}^{5}}, c, \frac{-1}{b}\right) \cdot c
\end{array}
Initial program 33.4%
Applied rewrites33.4%
Taylor expanded in c around 0
*-commutativeN/A
lower-*.f64N/A
Applied rewrites93.1%
Taylor expanded in b around 0
Applied rewrites93.1%
Final simplification93.1%
(FPCore (a b c) :precision binary64 (* (/ (fma (* (* a a) -2.0) (* c c) (* (* (- b) b) (fma b b (* c a)))) (pow b 5.0)) c))
double code(double a, double b, double c) {
return (fma(((a * a) * -2.0), (c * c), ((-b * b) * fma(b, b, (c * a)))) / pow(b, 5.0)) * c;
}
function code(a, b, c) return Float64(Float64(fma(Float64(Float64(a * a) * -2.0), Float64(c * c), Float64(Float64(Float64(-b) * b) * fma(b, b, Float64(c * a)))) / (b ^ 5.0)) * c) end
code[a_, b_, c_] := N[(N[(N[(N[(N[(a * a), $MachinePrecision] * -2.0), $MachinePrecision] * N[(c * c), $MachinePrecision] + N[(N[((-b) * b), $MachinePrecision] * N[(b * b + N[(c * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision] * c), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -2, c \cdot c, \left(\left(-b\right) \cdot b\right) \cdot \mathsf{fma}\left(b, b, c \cdot a\right)\right)}{{b}^{5}} \cdot c
\end{array}
Initial program 33.4%
Applied rewrites33.4%
Taylor expanded in c around 0
*-commutativeN/A
lower-*.f64N/A
Applied rewrites93.1%
Taylor expanded in b around 0
Applied rewrites92.7%
Final simplification92.7%
(FPCore (a b c) :precision binary64 (if (<= (/ (- (sqrt (- (* b b) (* (* a 4.0) c))) b) (* 2.0 a)) -5e-6) (/ (- (sqrt (fma (* -4.0 c) a (* b b))) b) (* 2.0 a)) (/ (- c) b)))
double code(double a, double b, double c) {
double tmp;
if (((sqrt(((b * b) - ((a * 4.0) * c))) - b) / (2.0 * a)) <= -5e-6) {
tmp = (sqrt(fma((-4.0 * c), a, (b * b))) - b) / (2.0 * a);
} else {
tmp = -c / b;
}
return tmp;
}
function code(a, b, c) tmp = 0.0 if (Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(Float64(a * 4.0) * c))) - b) / Float64(2.0 * a)) <= -5e-6) tmp = Float64(Float64(sqrt(fma(Float64(-4.0 * c), a, Float64(b * b))) - b) / Float64(2.0 * a)); else tmp = Float64(Float64(-c) / b); end return tmp end
code[a_, b_, c_] := If[LessEqual[N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(a * 4.0), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision], -5e-6], N[(N[(N[Sqrt[N[(N[(-4.0 * c), $MachinePrecision] * a + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision], N[((-c) / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\frac{\sqrt{b \cdot b - \left(a \cdot 4\right) \cdot c} - b}{2 \cdot a} \leq -5 \cdot 10^{-6}:\\
\;\;\;\;\frac{\sqrt{\mathsf{fma}\left(-4 \cdot c, a, b \cdot b\right)} - b}{2 \cdot a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
if (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 #s(literal 4 binary64) a) c)))) (*.f64 #s(literal 2 binary64) a)) < -5.00000000000000041e-6Initial program 65.9%
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6465.9
lift--.f64N/A
sub-negN/A
+-commutativeN/A
lift-*.f64N/A
lift-*.f64N/A
associate-*l*N/A
distribute-lft-neg-inN/A
*-commutativeN/A
associate-*r*N/A
lower-fma.f64N/A
lower-*.f64N/A
metadata-eval65.9
Applied rewrites65.9%
if -5.00000000000000041e-6 < (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 #s(literal 4 binary64) a) c)))) (*.f64 #s(literal 2 binary64) a)) Initial program 20.7%
Taylor expanded in c around 0
associate-*r/N/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6489.3
Applied rewrites89.3%
Final simplification82.7%
(FPCore (a b c) :precision binary64 (if (<= (/ (- (sqrt (- (* b b) (* (* a 4.0) c))) b) (* 2.0 a)) -5e-6) (* (/ 0.5 a) (- (sqrt (fma (* -4.0 c) a (* b b))) b)) (/ (- c) b)))
double code(double a, double b, double c) {
double tmp;
if (((sqrt(((b * b) - ((a * 4.0) * c))) - b) / (2.0 * a)) <= -5e-6) {
tmp = (0.5 / a) * (sqrt(fma((-4.0 * c), a, (b * b))) - b);
} else {
tmp = -c / b;
}
return tmp;
}
function code(a, b, c) tmp = 0.0 if (Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(Float64(a * 4.0) * c))) - b) / Float64(2.0 * a)) <= -5e-6) tmp = Float64(Float64(0.5 / a) * Float64(sqrt(fma(Float64(-4.0 * c), a, Float64(b * b))) - b)); else tmp = Float64(Float64(-c) / b); end return tmp end
code[a_, b_, c_] := If[LessEqual[N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(a * 4.0), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision], -5e-6], N[(N[(0.5 / a), $MachinePrecision] * N[(N[Sqrt[N[(N[(-4.0 * c), $MachinePrecision] * a + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision]), $MachinePrecision], N[((-c) / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\frac{\sqrt{b \cdot b - \left(a \cdot 4\right) \cdot c} - b}{2 \cdot a} \leq -5 \cdot 10^{-6}:\\
\;\;\;\;\frac{0.5}{a} \cdot \left(\sqrt{\mathsf{fma}\left(-4 \cdot c, a, b \cdot b\right)} - b\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
if (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 #s(literal 4 binary64) a) c)))) (*.f64 #s(literal 2 binary64) a)) < -5.00000000000000041e-6Initial program 65.9%
lift-/.f64N/A
clear-numN/A
associate-/r/N/A
lower-*.f64N/A
lift-*.f64N/A
associate-/r*N/A
metadata-evalN/A
lower-/.f6465.9
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6465.9
Applied rewrites65.9%
if -5.00000000000000041e-6 < (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 #s(literal 4 binary64) a) c)))) (*.f64 #s(literal 2 binary64) a)) Initial program 20.7%
Taylor expanded in c around 0
associate-*r/N/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6489.3
Applied rewrites89.3%
Final simplification82.7%
(FPCore (a b c) :precision binary64 (/ (fma (/ c b) (/ (* c a) b) c) (- b)))
double code(double a, double b, double c) {
return fma((c / b), ((c * a) / b), c) / -b;
}
function code(a, b, c) return Float64(fma(Float64(c / b), Float64(Float64(c * a) / b), c) / Float64(-b)) end
code[a_, b_, c_] := N[(N[(N[(c / b), $MachinePrecision] * N[(N[(c * a), $MachinePrecision] / b), $MachinePrecision] + c), $MachinePrecision] / (-b)), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\frac{c}{b}, \frac{c \cdot a}{b}, c\right)}{-b}
\end{array}
Initial program 33.4%
Taylor expanded in b around inf
distribute-lft-outN/A
associate-/l*N/A
mul-1-negN/A
lower-neg.f64N/A
lower-/.f64N/A
+-commutativeN/A
*-commutativeN/A
unpow2N/A
associate-*l*N/A
*-commutativeN/A
unpow2N/A
times-fracN/A
lower-fma.f64N/A
lower-/.f64N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f6490.5
Applied rewrites90.5%
Final simplification90.5%
(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(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 33.4%
Taylor expanded in c around 0
associate-*r/N/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6480.3
Applied rewrites80.3%
(FPCore (a b c) :precision binary64 0.0)
double code(double a, double b, double c) {
return 0.0;
}
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
end function
public static double code(double a, double b, double c) {
return 0.0;
}
def code(a, b, c): return 0.0
function code(a, b, c) return 0.0 end
function tmp = code(a, b, c) tmp = 0.0; end
code[a_, b_, c_] := 0.0
\begin{array}{l}
\\
0
\end{array}
Initial program 33.4%
Applied rewrites33.4%
Applied rewrites32.8%
Taylor expanded in c around 0
distribute-rgt-outN/A
metadata-evalN/A
mul0-rgt3.2
Applied rewrites3.2%
herbie shell --seed 2024264
(FPCore (a b c)
:name "Quadratic roots, medium range"
:precision binary64
:pre (and (and (and (< 1.1102230246251565e-16 a) (< a 9007199254740992.0)) (and (< 1.1102230246251565e-16 b) (< b 9007199254740992.0))) (and (< 1.1102230246251565e-16 c) (< c 9007199254740992.0)))
(/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))