
(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 (fma c (* a -3.0) (* b b))))))
double code(double a, double b, double c) {
return (fma(c, (a * -3.0), 0.0) / (a * 3.0)) / (b + sqrt(fma(c, (a * -3.0), (b * b))));
}
function code(a, b, c) return Float64(Float64(fma(c, Float64(a * -3.0), 0.0) / Float64(a * 3.0)) / Float64(b + sqrt(fma(c, Float64(a * -3.0), Float64(b * b))))) end
code[a_, b_, c_] := N[(N[(N[(c * N[(a * -3.0), $MachinePrecision] + 0.0), $MachinePrecision] / N[(a * 3.0), $MachinePrecision]), $MachinePrecision] / N[(b + N[Sqrt[N[(c * N[(a * -3.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{\mathsf{fma}\left(c, a \cdot -3, 0\right)}{a \cdot 3}}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -3, b \cdot b\right)}}
\end{array}
Initial program 18.0%
+-commutativeN/A
unsub-negN/A
div-subN/A
--lowering--.f64N/A
Applied egg-rr17.7%
associate-/r*N/A
associate-/r*N/A
sub-divN/A
/-lowering-/.f64N/A
Applied egg-rr17.7%
Applied egg-rr99.7%
(FPCore (a b c) :precision binary64 (/ (fma c (* a -3.0) 0.0) (* (* a 3.0) (+ b (sqrt (fma c (* a -3.0) (* b b)))))))
double code(double a, double b, double c) {
return fma(c, (a * -3.0), 0.0) / ((a * 3.0) * (b + sqrt(fma(c, (a * -3.0), (b * b)))));
}
function code(a, b, c) return Float64(fma(c, Float64(a * -3.0), 0.0) / Float64(Float64(a * 3.0) * Float64(b + sqrt(fma(c, Float64(a * -3.0), Float64(b * b)))))) 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[(c * N[(a * -3.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(c, a \cdot -3, 0\right)}{\left(a \cdot 3\right) \cdot \left(b + \sqrt{\mathsf{fma}\left(c, a \cdot -3, b \cdot b\right)}\right)}
\end{array}
Initial program 18.0%
+-commutativeN/A
unsub-negN/A
div-subN/A
--lowering--.f64N/A
Applied egg-rr17.7%
associate-/r*N/A
associate-/r*N/A
sub-divN/A
/-lowering-/.f64N/A
Applied egg-rr17.7%
Applied egg-rr99.4%
Final simplification99.4%
(FPCore (a b c) :precision binary64 (fma (/ (* (* c c) -0.375) (* b (* b b))) a (/ c (* b -2.0))))
double code(double a, double b, double c) {
return fma((((c * c) * -0.375) / (b * (b * b))), a, (c / (b * -2.0)));
}
function code(a, b, c) return fma(Float64(Float64(Float64(c * c) * -0.375) / Float64(b * Float64(b * b))), a, Float64(c / Float64(b * -2.0))) end
code[a_, b_, c_] := N[(N[(N[(N[(c * c), $MachinePrecision] * -0.375), $MachinePrecision] / N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * a + N[(c / N[(b * -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\frac{\left(c \cdot c\right) \cdot -0.375}{b \cdot \left(b \cdot b\right)}, a, \frac{c}{b \cdot -2}\right)
\end{array}
Initial program 18.0%
Taylor expanded in c around 0
sub-negN/A
distribute-lft-inN/A
associate-*r/N/A
associate-*r*N/A
associate-*l/N/A
associate-*r/N/A
distribute-lft-inN/A
*-lowering-*.f64N/A
associate-*r/N/A
associate-*l/N/A
associate-*r*N/A
associate-*r/N/A
*-commutativeN/A
associate-/l*N/A
associate-*l*N/A
Simplified94.8%
distribute-rgt-inN/A
*-commutativeN/A
*-commutativeN/A
associate-*r*N/A
associate-*l/N/A
associate-/l*N/A
associate-*l*N/A
associate-*l/N/A
associate-*r/N/A
accelerator-lowering-fma.f64N/A
/-lowering-/.f64N/A
*-lowering-*.f64N/A
*-lowering-*.f64N/A
*-lowering-*.f64N/A
*-lowering-*.f64N/A
*-commutativeN/A
associate-*l/N/A
associate-*r/N/A
clear-numN/A
un-div-invN/A
Applied egg-rr95.2%
(FPCore (a b c) :precision binary64 (/ (fma a (/ (* (* c c) -0.375) (* b b)) (* c -0.5)) b))
double code(double a, double b, double c) {
return fma(a, (((c * c) * -0.375) / (b * b)), (c * -0.5)) / b;
}
function code(a, b, c) return Float64(fma(a, Float64(Float64(Float64(c * c) * -0.375) / Float64(b * b)), Float64(c * -0.5)) / b) end
code[a_, b_, c_] := N[(N[(a * N[(N[(N[(c * c), $MachinePrecision] * -0.375), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + N[(c * -0.5), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(a, \frac{\left(c \cdot c\right) \cdot -0.375}{b \cdot b}, c \cdot -0.5\right)}{b}
\end{array}
Initial program 18.0%
Taylor expanded in b around inf
/-lowering-/.f64N/A
Simplified95.2%
(FPCore (a b c) :precision binary64 (* c (fma a (* -0.375 (/ c (* b (* b b)))) (/ -0.5 b))))
double code(double a, double b, double c) {
return c * fma(a, (-0.375 * (c / (b * (b * b)))), (-0.5 / b));
}
function code(a, b, c) return Float64(c * fma(a, Float64(-0.375 * Float64(c / Float64(b * Float64(b * b)))), Float64(-0.5 / b))) end
code[a_, b_, c_] := N[(c * N[(a * N[(-0.375 * N[(c / N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-0.5 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
c \cdot \mathsf{fma}\left(a, -0.375 \cdot \frac{c}{b \cdot \left(b \cdot b\right)}, \frac{-0.5}{b}\right)
\end{array}
Initial program 18.0%
Taylor expanded in c around 0
sub-negN/A
distribute-lft-inN/A
associate-*r/N/A
associate-*r*N/A
associate-*l/N/A
associate-*r/N/A
distribute-lft-inN/A
*-lowering-*.f64N/A
associate-*r/N/A
associate-*l/N/A
associate-*r*N/A
associate-*r/N/A
*-commutativeN/A
associate-/l*N/A
associate-*l*N/A
Simplified94.8%
Final simplification94.8%
(FPCore (a b c) :precision binary64 (* c (/ (fma a (* -0.375 (/ c (* b b))) -0.5) b)))
double code(double a, double b, double c) {
return c * (fma(a, (-0.375 * (c / (b * b))), -0.5) / b);
}
function code(a, b, c) return Float64(c * Float64(fma(a, Float64(-0.375 * Float64(c / Float64(b * b))), -0.5) / b)) end
code[a_, b_, c_] := N[(c * N[(N[(a * N[(-0.375 * N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -0.5), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
c \cdot \frac{\mathsf{fma}\left(a, -0.375 \cdot \frac{c}{b \cdot b}, -0.5\right)}{b}
\end{array}
Initial program 18.0%
Taylor expanded in c around 0
sub-negN/A
distribute-lft-inN/A
associate-*r/N/A
associate-*r*N/A
associate-*l/N/A
associate-*r/N/A
distribute-lft-inN/A
*-lowering-*.f64N/A
associate-*r/N/A
associate-*l/N/A
associate-*r*N/A
associate-*r/N/A
*-commutativeN/A
associate-/l*N/A
associate-*l*N/A
Simplified94.8%
Taylor expanded in b around inf
/-lowering-/.f64N/A
sub-negN/A
*-commutativeN/A
associate-/l*N/A
associate-*l*N/A
metadata-evalN/A
accelerator-lowering-fma.f64N/A
*-lowering-*.f64N/A
/-lowering-/.f64N/A
unpow2N/A
*-lowering-*.f6494.8
Simplified94.8%
Final simplification94.8%
(FPCore (a b c) :precision binary64 (* -0.5 (/ c b)))
double code(double a, double b, double c) {
return -0.5 * (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 = (-0.5d0) * (c / b)
end function
public static double code(double a, double b, double c) {
return -0.5 * (c / b);
}
def code(a, b, c): return -0.5 * (c / b)
function code(a, b, c) return Float64(-0.5 * Float64(c / b)) end
function tmp = code(a, b, c) tmp = -0.5 * (c / b); end
code[a_, b_, c_] := N[(-0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
-0.5 \cdot \frac{c}{b}
\end{array}
Initial program 18.0%
Taylor expanded in b around inf
*-lowering-*.f64N/A
/-lowering-/.f6490.2
Simplified90.2%
(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 18.0%
+-commutativeN/A
unsub-negN/A
div-subN/A
--lowering--.f64N/A
Applied egg-rr17.7%
sub-negN/A
frac-2negN/A
div-invN/A
accelerator-lowering-fma.f64N/A
Applied egg-rr19.3%
Taylor expanded in c around 0
distribute-rgt-outN/A
metadata-evalN/A
mul0-rgt3.3
Simplified3.3%
herbie shell --seed 2024198
(FPCore (a b c)
:name "Cubic critical, wide range"
:precision binary64
:pre (and (and (and (< 4.930380657631324e-32 a) (< a 2.028240960365167e+31)) (and (< 4.930380657631324e-32 b) (< b 2.028240960365167e+31))) (and (< 4.930380657631324e-32 c) (< c 2.028240960365167e+31)))
(/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)))