
(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 7 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
(if (<= b -6.5e+152)
(/ (- b) a)
(if (<= b 2.4e-45)
(/ (- (sqrt (- (* b b) (* (* a 4.0) c))) b) (* 2.0 a))
(/ (- c) b))))
double code(double a, double b, double c) {
double tmp;
if (b <= -6.5e+152) {
tmp = -b / a;
} else if (b <= 2.4e-45) {
tmp = (sqrt(((b * b) - ((a * 4.0) * c))) - b) / (2.0 * a);
} else {
tmp = -c / 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 <= (-6.5d+152)) then
tmp = -b / a
else if (b <= 2.4d-45) then
tmp = (sqrt(((b * b) - ((a * 4.0d0) * c))) - b) / (2.0d0 * a)
else
tmp = -c / b
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -6.5e+152) {
tmp = -b / a;
} else if (b <= 2.4e-45) {
tmp = (Math.sqrt(((b * b) - ((a * 4.0) * c))) - b) / (2.0 * a);
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -6.5e+152: tmp = -b / a elif b <= 2.4e-45: tmp = (math.sqrt(((b * b) - ((a * 4.0) * c))) - b) / (2.0 * a) else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -6.5e+152) tmp = Float64(Float64(-b) / a); elseif (b <= 2.4e-45) tmp = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(Float64(a * 4.0) * c))) - b) / Float64(2.0 * a)); else tmp = Float64(Float64(-c) / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -6.5e+152) tmp = -b / a; elseif (b <= 2.4e-45) tmp = (sqrt(((b * b) - ((a * 4.0) * c))) - b) / (2.0 * a); else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -6.5e+152], N[((-b) / a), $MachinePrecision], If[LessEqual[b, 2.4e-45], 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], N[((-c) / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -6.5 \cdot 10^{+152}:\\
\;\;\;\;\frac{-b}{a}\\
\mathbf{elif}\;b \leq 2.4 \cdot 10^{-45}:\\
\;\;\;\;\frac{\sqrt{b \cdot b - \left(a \cdot 4\right) \cdot c} - b}{2 \cdot a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
if b < -6.4999999999999997e152Initial program 29.0%
Taylor expanded in b around -inf
associate-*r/N/A
mul-1-negN/A
lower-/.f64N/A
lower-neg.f6495.4
Applied rewrites95.4%
if -6.4999999999999997e152 < b < 2.3999999999999999e-45Initial program 83.9%
if 2.3999999999999999e-45 < b Initial program 17.1%
Taylor expanded in c around 0
associate-*r/N/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6487.0
Applied rewrites87.0%
Final simplification86.7%
(FPCore (a b c)
:precision binary64
(if (<= b -2.6e+75)
(fma (/ c (* b b)) b (/ (- b) a))
(if (<= b 2.4e-45)
(* (- (sqrt (fma (* -4.0 c) a (* b b))) b) (/ 0.5 a))
(/ (- c) b))))
double code(double a, double b, double c) {
double tmp;
if (b <= -2.6e+75) {
tmp = fma((c / (b * b)), b, (-b / a));
} else if (b <= 2.4e-45) {
tmp = (sqrt(fma((-4.0 * c), a, (b * b))) - b) * (0.5 / a);
} else {
tmp = -c / b;
}
return tmp;
}
function code(a, b, c) tmp = 0.0 if (b <= -2.6e+75) tmp = fma(Float64(c / Float64(b * b)), b, Float64(Float64(-b) / a)); elseif (b <= 2.4e-45) tmp = Float64(Float64(sqrt(fma(Float64(-4.0 * c), a, Float64(b * b))) - b) * Float64(0.5 / a)); else tmp = Float64(Float64(-c) / b); end return tmp end
code[a_, b_, c_] := If[LessEqual[b, -2.6e+75], N[(N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision] * b + N[((-b) / a), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 2.4e-45], N[(N[(N[Sqrt[N[(N[(-4.0 * c), $MachinePrecision] * a + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] * N[(0.5 / a), $MachinePrecision]), $MachinePrecision], N[((-c) / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -2.6 \cdot 10^{+75}:\\
\;\;\;\;\mathsf{fma}\left(\frac{c}{b \cdot b}, b, \frac{-b}{a}\right)\\
\mathbf{elif}\;b \leq 2.4 \cdot 10^{-45}:\\
\;\;\;\;\left(\sqrt{\mathsf{fma}\left(-4 \cdot c, a, b \cdot b\right)} - b\right) \cdot \frac{0.5}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
if b < -2.59999999999999985e75Initial program 54.6%
Taylor expanded in b around -inf
mul-1-negN/A
distribute-rgt-inN/A
distribute-neg-inN/A
mul-1-negN/A
distribute-lft-neg-outN/A
remove-double-negN/A
associate-*l/N/A
*-lft-identityN/A
lower-fma.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f64N/A
distribute-frac-negN/A
lower-/.f64N/A
lower-neg.f6497.0
Applied rewrites97.0%
if -2.59999999999999985e75 < b < 2.3999999999999999e-45Initial program 80.7%
lift-/.f64N/A
clear-numN/A
associate-/r/N/A
lower-*.f64N/A
lift-*.f64N/A
associate-/r*N/A
metadata-evalN/A
lower-/.f6480.4
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6480.4
Applied rewrites80.4%
if 2.3999999999999999e-45 < b Initial program 17.1%
Taylor expanded in c around 0
associate-*r/N/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6487.0
Applied rewrites87.0%
Final simplification86.5%
(FPCore (a b c)
:precision binary64
(if (<= b -1.95e-57)
(fma (/ c (* b b)) b (/ (- b) a))
(if (<= b 2.4e-45)
(/ (- (sqrt (* (* c a) -4.0)) b) (* 2.0 a))
(/ (- c) b))))
double code(double a, double b, double c) {
double tmp;
if (b <= -1.95e-57) {
tmp = fma((c / (b * b)), b, (-b / a));
} else if (b <= 2.4e-45) {
tmp = (sqrt(((c * a) * -4.0)) - b) / (2.0 * a);
} else {
tmp = -c / b;
}
return tmp;
}
function code(a, b, c) tmp = 0.0 if (b <= -1.95e-57) tmp = fma(Float64(c / Float64(b * b)), b, Float64(Float64(-b) / a)); elseif (b <= 2.4e-45) tmp = Float64(Float64(sqrt(Float64(Float64(c * a) * -4.0)) - b) / Float64(2.0 * a)); else tmp = Float64(Float64(-c) / b); end return tmp end
code[a_, b_, c_] := If[LessEqual[b, -1.95e-57], N[(N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision] * b + N[((-b) / a), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 2.4e-45], N[(N[(N[Sqrt[N[(N[(c * a), $MachinePrecision] * -4.0), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision], N[((-c) / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -1.95 \cdot 10^{-57}:\\
\;\;\;\;\mathsf{fma}\left(\frac{c}{b \cdot b}, b, \frac{-b}{a}\right)\\
\mathbf{elif}\;b \leq 2.4 \cdot 10^{-45}:\\
\;\;\;\;\frac{\sqrt{\left(c \cdot a\right) \cdot -4} - b}{2 \cdot a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
if b < -1.95000000000000003e-57Initial program 68.5%
Taylor expanded in b around -inf
mul-1-negN/A
distribute-rgt-inN/A
distribute-neg-inN/A
mul-1-negN/A
distribute-lft-neg-outN/A
remove-double-negN/A
associate-*l/N/A
*-lft-identityN/A
lower-fma.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f64N/A
distribute-frac-negN/A
lower-/.f64N/A
lower-neg.f6490.2
Applied rewrites90.2%
if -1.95000000000000003e-57 < b < 2.3999999999999999e-45Initial program 74.9%
Taylor expanded in c around inf
lower-*.f64N/A
*-commutativeN/A
lower-*.f6467.9
Applied rewrites67.9%
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6467.9
Applied rewrites67.9%
if 2.3999999999999999e-45 < b Initial program 17.1%
Taylor expanded in c around 0
associate-*r/N/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6487.0
Applied rewrites87.0%
(FPCore (a b c)
:precision binary64
(if (<= b -3.2e-58)
(fma (/ c (* b b)) b (/ (- b) a))
(if (<= b 2.4e-45)
(* (- (sqrt (* (* -4.0 c) a)) b) (/ 0.5 a))
(/ (- c) b))))
double code(double a, double b, double c) {
double tmp;
if (b <= -3.2e-58) {
tmp = fma((c / (b * b)), b, (-b / a));
} else if (b <= 2.4e-45) {
tmp = (sqrt(((-4.0 * c) * a)) - b) * (0.5 / a);
} else {
tmp = -c / b;
}
return tmp;
}
function code(a, b, c) tmp = 0.0 if (b <= -3.2e-58) tmp = fma(Float64(c / Float64(b * b)), b, Float64(Float64(-b) / a)); elseif (b <= 2.4e-45) tmp = Float64(Float64(sqrt(Float64(Float64(-4.0 * c) * a)) - b) * Float64(0.5 / a)); else tmp = Float64(Float64(-c) / b); end return tmp end
code[a_, b_, c_] := If[LessEqual[b, -3.2e-58], N[(N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision] * b + N[((-b) / a), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 2.4e-45], N[(N[(N[Sqrt[N[(N[(-4.0 * c), $MachinePrecision] * a), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] * N[(0.5 / a), $MachinePrecision]), $MachinePrecision], N[((-c) / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -3.2 \cdot 10^{-58}:\\
\;\;\;\;\mathsf{fma}\left(\frac{c}{b \cdot b}, b, \frac{-b}{a}\right)\\
\mathbf{elif}\;b \leq 2.4 \cdot 10^{-45}:\\
\;\;\;\;\left(\sqrt{\left(-4 \cdot c\right) \cdot a} - b\right) \cdot \frac{0.5}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
if b < -3.2000000000000001e-58Initial program 68.5%
Taylor expanded in b around -inf
mul-1-negN/A
distribute-rgt-inN/A
distribute-neg-inN/A
mul-1-negN/A
distribute-lft-neg-outN/A
remove-double-negN/A
associate-*l/N/A
*-lft-identityN/A
lower-fma.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f64N/A
distribute-frac-negN/A
lower-/.f64N/A
lower-neg.f6490.2
Applied rewrites90.2%
if -3.2000000000000001e-58 < b < 2.3999999999999999e-45Initial program 74.9%
lift-/.f64N/A
clear-numN/A
associate-/r/N/A
lower-*.f64N/A
lift-*.f64N/A
associate-/r*N/A
metadata-evalN/A
lower-/.f6474.7
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6474.7
Applied rewrites74.7%
Taylor expanded in c around inf
*-commutativeN/A
rem-square-sqrtN/A
unpow2N/A
associate-*r*N/A
*-commutativeN/A
*-commutativeN/A
unpow2N/A
rem-square-sqrtN/A
lower-*.f64N/A
lower-*.f6467.7
Applied rewrites67.7%
if 2.3999999999999999e-45 < b Initial program 17.1%
Taylor expanded in c around 0
associate-*r/N/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6487.0
Applied rewrites87.0%
Final simplification82.4%
(FPCore (a b c) :precision binary64 (if (<= b 8e-295) (/ (- b) a) (/ (- c) b)))
double code(double a, double b, double c) {
double tmp;
if (b <= 8e-295) {
tmp = -b / a;
} else {
tmp = -c / 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 <= 8d-295) then
tmp = -b / a
else
tmp = -c / b
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= 8e-295) {
tmp = -b / a;
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= 8e-295: tmp = -b / a else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= 8e-295) tmp = Float64(Float64(-b) / a); else tmp = Float64(Float64(-c) / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= 8e-295) tmp = -b / a; else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, 8e-295], N[((-b) / a), $MachinePrecision], N[((-c) / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 8 \cdot 10^{-295}:\\
\;\;\;\;\frac{-b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
if b < 8.00000000000000048e-295Initial program 71.8%
Taylor expanded in b around -inf
associate-*r/N/A
mul-1-negN/A
lower-/.f64N/A
lower-neg.f6471.1
Applied rewrites71.1%
if 8.00000000000000048e-295 < b Initial program 34.3%
Taylor expanded in c around 0
associate-*r/N/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6465.0
Applied rewrites65.0%
(FPCore (a b c) :precision binary64 (/ (- b) a))
double code(double a, double b, double c) {
return -b / 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 / a
end function
public static double code(double a, double b, double c) {
return -b / a;
}
def code(a, b, c): return -b / a
function code(a, b, c) return Float64(Float64(-b) / a) end
function tmp = code(a, b, c) tmp = -b / a; end
code[a_, b_, c_] := N[((-b) / a), $MachinePrecision]
\begin{array}{l}
\\
\frac{-b}{a}
\end{array}
Initial program 53.4%
Taylor expanded in b around -inf
associate-*r/N/A
mul-1-negN/A
lower-/.f64N/A
lower-neg.f6437.2
Applied rewrites37.2%
(FPCore (a b c) :precision binary64 (/ b a))
double code(double a, double b, double c) {
return b / 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 / a
end function
public static double code(double a, double b, double c) {
return b / a;
}
def code(a, b, c): return b / a
function code(a, b, c) return Float64(b / a) end
function tmp = code(a, b, c) tmp = b / a; end
code[a_, b_, c_] := N[(b / a), $MachinePrecision]
\begin{array}{l}
\\
\frac{b}{a}
\end{array}
Initial program 53.4%
Taylor expanded in b around -inf
associate-*r/N/A
mul-1-negN/A
lower-/.f64N/A
lower-neg.f6437.2
Applied rewrites37.2%
Applied rewrites26.8%
Applied rewrites2.7%
herbie shell --seed 2024235
(FPCore (a b c)
:name "Quadratic roots, full range"
:precision binary64
(/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))