
(FPCore (a b_2 c) :precision binary64 (/ (+ (- b_2) (sqrt (- (* b_2 b_2) (* a c)))) a))
double code(double a, double b_2, double c) {
return (-b_2 + sqrt(((b_2 * b_2) - (a * c)))) / a;
}
real(8) function code(a, b_2, c)
real(8), intent (in) :: a
real(8), intent (in) :: b_2
real(8), intent (in) :: c
code = (-b_2 + sqrt(((b_2 * b_2) - (a * c)))) / a
end function
public static double code(double a, double b_2, double c) {
return (-b_2 + Math.sqrt(((b_2 * b_2) - (a * c)))) / a;
}
def code(a, b_2, c): return (-b_2 + math.sqrt(((b_2 * b_2) - (a * c)))) / a
function code(a, b_2, c) return Float64(Float64(Float64(-b_2) + sqrt(Float64(Float64(b_2 * b_2) - Float64(a * c)))) / a) end
function tmp = code(a, b_2, c) tmp = (-b_2 + sqrt(((b_2 * b_2) - (a * c)))) / a; end
code[a_, b$95$2_, c_] := N[(N[((-b$95$2) + N[Sqrt[N[(N[(b$95$2 * b$95$2), $MachinePrecision] - N[(a * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\_2\right) + \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (a b_2 c) :precision binary64 (/ (+ (- b_2) (sqrt (- (* b_2 b_2) (* a c)))) a))
double code(double a, double b_2, double c) {
return (-b_2 + sqrt(((b_2 * b_2) - (a * c)))) / a;
}
real(8) function code(a, b_2, c)
real(8), intent (in) :: a
real(8), intent (in) :: b_2
real(8), intent (in) :: c
code = (-b_2 + sqrt(((b_2 * b_2) - (a * c)))) / a
end function
public static double code(double a, double b_2, double c) {
return (-b_2 + Math.sqrt(((b_2 * b_2) - (a * c)))) / a;
}
def code(a, b_2, c): return (-b_2 + math.sqrt(((b_2 * b_2) - (a * c)))) / a
function code(a, b_2, c) return Float64(Float64(Float64(-b_2) + sqrt(Float64(Float64(b_2 * b_2) - Float64(a * c)))) / a) end
function tmp = code(a, b_2, c) tmp = (-b_2 + sqrt(((b_2 * b_2) - (a * c)))) / a; end
code[a_, b$95$2_, c_] := N[(N[((-b$95$2) + N[Sqrt[N[(N[(b$95$2 * b$95$2), $MachinePrecision] - N[(a * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\_2\right) + \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a}
\end{array}
(FPCore (a b_2 c)
:precision binary64
(if (<= b_2 -4.6e+51)
(* (/ b_2 a) -2.0)
(if (<= b_2 5.8e-106)
(/ (- (sqrt (fma b_2 b_2 (* (- a) c))) b_2) a)
(/ (* -0.5 c) b_2))))
double code(double a, double b_2, double c) {
double tmp;
if (b_2 <= -4.6e+51) {
tmp = (b_2 / a) * -2.0;
} else if (b_2 <= 5.8e-106) {
tmp = (sqrt(fma(b_2, b_2, (-a * c))) - b_2) / a;
} else {
tmp = (-0.5 * c) / b_2;
}
return tmp;
}
function code(a, b_2, c) tmp = 0.0 if (b_2 <= -4.6e+51) tmp = Float64(Float64(b_2 / a) * -2.0); elseif (b_2 <= 5.8e-106) tmp = Float64(Float64(sqrt(fma(b_2, b_2, Float64(Float64(-a) * c))) - b_2) / a); else tmp = Float64(Float64(-0.5 * c) / b_2); end return tmp end
code[a_, b$95$2_, c_] := If[LessEqual[b$95$2, -4.6e+51], N[(N[(b$95$2 / a), $MachinePrecision] * -2.0), $MachinePrecision], If[LessEqual[b$95$2, 5.8e-106], N[(N[(N[Sqrt[N[(b$95$2 * b$95$2 + N[((-a) * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b$95$2), $MachinePrecision] / a), $MachinePrecision], N[(N[(-0.5 * c), $MachinePrecision] / b$95$2), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b\_2 \leq -4.6 \cdot 10^{+51}:\\
\;\;\;\;\frac{b\_2}{a} \cdot -2\\
\mathbf{elif}\;b\_2 \leq 5.8 \cdot 10^{-106}:\\
\;\;\;\;\frac{\sqrt{\mathsf{fma}\left(b\_2, b\_2, \left(-a\right) \cdot c\right)} - b\_2}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-0.5 \cdot c}{b\_2}\\
\end{array}
\end{array}
if b_2 < -4.6000000000000001e51Initial program 63.6%
Taylor expanded in b_2 around -inf
lower-*.f64N/A
lower-/.f6494.8
Applied rewrites94.8%
if -4.6000000000000001e51 < b_2 < 5.8000000000000001e-106Initial program 80.0%
lift--.f64N/A
sub-negN/A
lift-*.f64N/A
lower-fma.f64N/A
lift-*.f64N/A
distribute-lft-neg-inN/A
lower-*.f64N/A
lower-neg.f6480.0
Applied rewrites80.0%
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6480.0
lift-*.f64N/A
*-commutativeN/A
lower-*.f6480.0
Applied rewrites80.0%
if 5.8000000000000001e-106 < b_2 Initial program 20.2%
Taylor expanded in b_2 around inf
lower-/.f64N/A
+-commutativeN/A
associate-*r/N/A
unpow2N/A
times-fracN/A
lower-fma.f64N/A
lower-/.f64N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f6466.8
Applied rewrites66.8%
Taylor expanded in a around 0
Applied rewrites82.6%
Final simplification85.1%
(FPCore (a b_2 c) :precision binary64 (if (<= b_2 -8.5e-67) (* (/ b_2 a) -2.0) (if (<= b_2 5.8e-106) (/ (- (sqrt (* (- a) c)) b_2) a) (/ (* -0.5 c) b_2))))
double code(double a, double b_2, double c) {
double tmp;
if (b_2 <= -8.5e-67) {
tmp = (b_2 / a) * -2.0;
} else if (b_2 <= 5.8e-106) {
tmp = (sqrt((-a * c)) - b_2) / a;
} else {
tmp = (-0.5 * c) / b_2;
}
return tmp;
}
real(8) function code(a, b_2, c)
real(8), intent (in) :: a
real(8), intent (in) :: b_2
real(8), intent (in) :: c
real(8) :: tmp
if (b_2 <= (-8.5d-67)) then
tmp = (b_2 / a) * (-2.0d0)
else if (b_2 <= 5.8d-106) then
tmp = (sqrt((-a * c)) - b_2) / a
else
tmp = ((-0.5d0) * c) / b_2
end if
code = tmp
end function
public static double code(double a, double b_2, double c) {
double tmp;
if (b_2 <= -8.5e-67) {
tmp = (b_2 / a) * -2.0;
} else if (b_2 <= 5.8e-106) {
tmp = (Math.sqrt((-a * c)) - b_2) / a;
} else {
tmp = (-0.5 * c) / b_2;
}
return tmp;
}
def code(a, b_2, c): tmp = 0 if b_2 <= -8.5e-67: tmp = (b_2 / a) * -2.0 elif b_2 <= 5.8e-106: tmp = (math.sqrt((-a * c)) - b_2) / a else: tmp = (-0.5 * c) / b_2 return tmp
function code(a, b_2, c) tmp = 0.0 if (b_2 <= -8.5e-67) tmp = Float64(Float64(b_2 / a) * -2.0); elseif (b_2 <= 5.8e-106) tmp = Float64(Float64(sqrt(Float64(Float64(-a) * c)) - b_2) / a); else tmp = Float64(Float64(-0.5 * c) / b_2); end return tmp end
function tmp_2 = code(a, b_2, c) tmp = 0.0; if (b_2 <= -8.5e-67) tmp = (b_2 / a) * -2.0; elseif (b_2 <= 5.8e-106) tmp = (sqrt((-a * c)) - b_2) / a; else tmp = (-0.5 * c) / b_2; end tmp_2 = tmp; end
code[a_, b$95$2_, c_] := If[LessEqual[b$95$2, -8.5e-67], N[(N[(b$95$2 / a), $MachinePrecision] * -2.0), $MachinePrecision], If[LessEqual[b$95$2, 5.8e-106], N[(N[(N[Sqrt[N[((-a) * c), $MachinePrecision]], $MachinePrecision] - b$95$2), $MachinePrecision] / a), $MachinePrecision], N[(N[(-0.5 * c), $MachinePrecision] / b$95$2), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b\_2 \leq -8.5 \cdot 10^{-67}:\\
\;\;\;\;\frac{b\_2}{a} \cdot -2\\
\mathbf{elif}\;b\_2 \leq 5.8 \cdot 10^{-106}:\\
\;\;\;\;\frac{\sqrt{\left(-a\right) \cdot c} - b\_2}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-0.5 \cdot c}{b\_2}\\
\end{array}
\end{array}
if b_2 < -8.49999999999999993e-67Initial program 71.8%
Taylor expanded in b_2 around -inf
lower-*.f64N/A
lower-/.f6492.6
Applied rewrites92.6%
if -8.49999999999999993e-67 < b_2 < 5.8000000000000001e-106Initial program 73.0%
Taylor expanded in a around inf
associate-*r*N/A
lower-*.f64N/A
mul-1-negN/A
lower-neg.f6466.2
Applied rewrites66.2%
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6466.2
Applied rewrites66.2%
if 5.8000000000000001e-106 < b_2 Initial program 20.2%
Taylor expanded in b_2 around inf
lower-/.f64N/A
+-commutativeN/A
associate-*r/N/A
unpow2N/A
times-fracN/A
lower-fma.f64N/A
lower-/.f64N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f6466.8
Applied rewrites66.8%
Taylor expanded in a around 0
Applied rewrites82.6%
Final simplification82.3%
(FPCore (a b_2 c) :precision binary64 (if (<= b_2 2.8e-308) (* (/ b_2 a) -2.0) (/ (* -0.5 c) b_2)))
double code(double a, double b_2, double c) {
double tmp;
if (b_2 <= 2.8e-308) {
tmp = (b_2 / a) * -2.0;
} else {
tmp = (-0.5 * c) / b_2;
}
return tmp;
}
real(8) function code(a, b_2, c)
real(8), intent (in) :: a
real(8), intent (in) :: b_2
real(8), intent (in) :: c
real(8) :: tmp
if (b_2 <= 2.8d-308) then
tmp = (b_2 / a) * (-2.0d0)
else
tmp = ((-0.5d0) * c) / b_2
end if
code = tmp
end function
public static double code(double a, double b_2, double c) {
double tmp;
if (b_2 <= 2.8e-308) {
tmp = (b_2 / a) * -2.0;
} else {
tmp = (-0.5 * c) / b_2;
}
return tmp;
}
def code(a, b_2, c): tmp = 0 if b_2 <= 2.8e-308: tmp = (b_2 / a) * -2.0 else: tmp = (-0.5 * c) / b_2 return tmp
function code(a, b_2, c) tmp = 0.0 if (b_2 <= 2.8e-308) tmp = Float64(Float64(b_2 / a) * -2.0); else tmp = Float64(Float64(-0.5 * c) / b_2); end return tmp end
function tmp_2 = code(a, b_2, c) tmp = 0.0; if (b_2 <= 2.8e-308) tmp = (b_2 / a) * -2.0; else tmp = (-0.5 * c) / b_2; end tmp_2 = tmp; end
code[a_, b$95$2_, c_] := If[LessEqual[b$95$2, 2.8e-308], N[(N[(b$95$2 / a), $MachinePrecision] * -2.0), $MachinePrecision], N[(N[(-0.5 * c), $MachinePrecision] / b$95$2), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b\_2 \leq 2.8 \cdot 10^{-308}:\\
\;\;\;\;\frac{b\_2}{a} \cdot -2\\
\mathbf{else}:\\
\;\;\;\;\frac{-0.5 \cdot c}{b\_2}\\
\end{array}
\end{array}
if b_2 < 2.79999999999999984e-308Initial program 74.3%
Taylor expanded in b_2 around -inf
lower-*.f64N/A
lower-/.f6472.9
Applied rewrites72.9%
if 2.79999999999999984e-308 < b_2 Initial program 28.3%
Taylor expanded in b_2 around inf
lower-/.f64N/A
+-commutativeN/A
associate-*r/N/A
unpow2N/A
times-fracN/A
lower-fma.f64N/A
lower-/.f64N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f6455.7
Applied rewrites55.7%
Taylor expanded in a around 0
Applied rewrites68.9%
Final simplification70.9%
(FPCore (a b_2 c) :precision binary64 (if (<= b_2 2.8e-308) (* (/ b_2 a) -2.0) (* (/ c b_2) -0.5)))
double code(double a, double b_2, double c) {
double tmp;
if (b_2 <= 2.8e-308) {
tmp = (b_2 / a) * -2.0;
} else {
tmp = (c / b_2) * -0.5;
}
return tmp;
}
real(8) function code(a, b_2, c)
real(8), intent (in) :: a
real(8), intent (in) :: b_2
real(8), intent (in) :: c
real(8) :: tmp
if (b_2 <= 2.8d-308) then
tmp = (b_2 / a) * (-2.0d0)
else
tmp = (c / b_2) * (-0.5d0)
end if
code = tmp
end function
public static double code(double a, double b_2, double c) {
double tmp;
if (b_2 <= 2.8e-308) {
tmp = (b_2 / a) * -2.0;
} else {
tmp = (c / b_2) * -0.5;
}
return tmp;
}
def code(a, b_2, c): tmp = 0 if b_2 <= 2.8e-308: tmp = (b_2 / a) * -2.0 else: tmp = (c / b_2) * -0.5 return tmp
function code(a, b_2, c) tmp = 0.0 if (b_2 <= 2.8e-308) tmp = Float64(Float64(b_2 / a) * -2.0); else tmp = Float64(Float64(c / b_2) * -0.5); end return tmp end
function tmp_2 = code(a, b_2, c) tmp = 0.0; if (b_2 <= 2.8e-308) tmp = (b_2 / a) * -2.0; else tmp = (c / b_2) * -0.5; end tmp_2 = tmp; end
code[a_, b$95$2_, c_] := If[LessEqual[b$95$2, 2.8e-308], N[(N[(b$95$2 / a), $MachinePrecision] * -2.0), $MachinePrecision], N[(N[(c / b$95$2), $MachinePrecision] * -0.5), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b\_2 \leq 2.8 \cdot 10^{-308}:\\
\;\;\;\;\frac{b\_2}{a} \cdot -2\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{b\_2} \cdot -0.5\\
\end{array}
\end{array}
if b_2 < 2.79999999999999984e-308Initial program 74.3%
Taylor expanded in b_2 around -inf
lower-*.f64N/A
lower-/.f6472.9
Applied rewrites72.9%
if 2.79999999999999984e-308 < b_2 Initial program 28.3%
Taylor expanded in a around 0
*-commutativeN/A
lower-*.f64N/A
lower-/.f6468.9
Applied rewrites68.9%
Final simplification70.9%
(FPCore (a b_2 c) :precision binary64 (* (/ b_2 a) -2.0))
double code(double a, double b_2, double c) {
return (b_2 / a) * -2.0;
}
real(8) function code(a, b_2, c)
real(8), intent (in) :: a
real(8), intent (in) :: b_2
real(8), intent (in) :: c
code = (b_2 / a) * (-2.0d0)
end function
public static double code(double a, double b_2, double c) {
return (b_2 / a) * -2.0;
}
def code(a, b_2, c): return (b_2 / a) * -2.0
function code(a, b_2, c) return Float64(Float64(b_2 / a) * -2.0) end
function tmp = code(a, b_2, c) tmp = (b_2 / a) * -2.0; end
code[a_, b$95$2_, c_] := N[(N[(b$95$2 / a), $MachinePrecision] * -2.0), $MachinePrecision]
\begin{array}{l}
\\
\frac{b\_2}{a} \cdot -2
\end{array}
Initial program 51.1%
Taylor expanded in b_2 around -inf
lower-*.f64N/A
lower-/.f6437.5
Applied rewrites37.5%
Final simplification37.5%
(FPCore (a b_2 c)
:precision binary64
(let* ((t_0 (* (sqrt (fabs a)) (sqrt (fabs c))))
(t_1
(if (== (copysign a c) a)
(* (sqrt (- (fabs b_2) t_0)) (sqrt (+ (fabs b_2) t_0)))
(hypot b_2 t_0))))
(if (< b_2 0.0) (/ (- t_1 b_2) a) (/ (- c) (+ b_2 t_1)))))
double code(double a, double b_2, double c) {
double t_0 = sqrt(fabs(a)) * sqrt(fabs(c));
double tmp;
if (copysign(a, c) == a) {
tmp = sqrt((fabs(b_2) - t_0)) * sqrt((fabs(b_2) + t_0));
} else {
tmp = hypot(b_2, t_0);
}
double t_1 = tmp;
double tmp_1;
if (b_2 < 0.0) {
tmp_1 = (t_1 - b_2) / a;
} else {
tmp_1 = -c / (b_2 + t_1);
}
return tmp_1;
}
public static double code(double a, double b_2, double c) {
double t_0 = Math.sqrt(Math.abs(a)) * Math.sqrt(Math.abs(c));
double tmp;
if (Math.copySign(a, c) == a) {
tmp = Math.sqrt((Math.abs(b_2) - t_0)) * Math.sqrt((Math.abs(b_2) + t_0));
} else {
tmp = Math.hypot(b_2, t_0);
}
double t_1 = tmp;
double tmp_1;
if (b_2 < 0.0) {
tmp_1 = (t_1 - b_2) / a;
} else {
tmp_1 = -c / (b_2 + t_1);
}
return tmp_1;
}
def code(a, b_2, c): t_0 = math.sqrt(math.fabs(a)) * math.sqrt(math.fabs(c)) tmp = 0 if math.copysign(a, c) == a: tmp = math.sqrt((math.fabs(b_2) - t_0)) * math.sqrt((math.fabs(b_2) + t_0)) else: tmp = math.hypot(b_2, t_0) t_1 = tmp tmp_1 = 0 if b_2 < 0.0: tmp_1 = (t_1 - b_2) / a else: tmp_1 = -c / (b_2 + t_1) return tmp_1
function code(a, b_2, c) t_0 = Float64(sqrt(abs(a)) * sqrt(abs(c))) tmp = 0.0 if (copysign(a, c) == a) tmp = Float64(sqrt(Float64(abs(b_2) - t_0)) * sqrt(Float64(abs(b_2) + t_0))); else tmp = hypot(b_2, t_0); end t_1 = tmp tmp_1 = 0.0 if (b_2 < 0.0) tmp_1 = Float64(Float64(t_1 - b_2) / a); else tmp_1 = Float64(Float64(-c) / Float64(b_2 + t_1)); end return tmp_1 end
function tmp_3 = code(a, b_2, c) t_0 = sqrt(abs(a)) * sqrt(abs(c)); tmp = 0.0; if ((sign(c) * abs(a)) == a) tmp = sqrt((abs(b_2) - t_0)) * sqrt((abs(b_2) + t_0)); else tmp = hypot(b_2, t_0); end t_1 = tmp; tmp_2 = 0.0; if (b_2 < 0.0) tmp_2 = (t_1 - b_2) / a; else tmp_2 = -c / (b_2 + t_1); end tmp_3 = tmp_2; end
code[a_, b$95$2_, c_] := Block[{t$95$0 = N[(N[Sqrt[N[Abs[a], $MachinePrecision]], $MachinePrecision] * N[Sqrt[N[Abs[c], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = If[Equal[N[With[{TMP1 = Abs[a], TMP2 = Sign[c]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], a], N[(N[Sqrt[N[(N[Abs[b$95$2], $MachinePrecision] - t$95$0), $MachinePrecision]], $MachinePrecision] * N[Sqrt[N[(N[Abs[b$95$2], $MachinePrecision] + t$95$0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[Sqrt[b$95$2 ^ 2 + t$95$0 ^ 2], $MachinePrecision]]}, If[Less[b$95$2, 0.0], N[(N[(t$95$1 - b$95$2), $MachinePrecision] / a), $MachinePrecision], N[((-c) / N[(b$95$2 + t$95$1), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{\left|a\right|} \cdot \sqrt{\left|c\right|}\\
t_1 := \begin{array}{l}
\mathbf{if}\;\mathsf{copysign}\left(a, c\right) = a:\\
\;\;\;\;\sqrt{\left|b\_2\right| - t\_0} \cdot \sqrt{\left|b\_2\right| + t\_0}\\
\mathbf{else}:\\
\;\;\;\;\mathsf{hypot}\left(b\_2, t\_0\right)\\
\end{array}\\
\mathbf{if}\;b\_2 < 0:\\
\;\;\;\;\frac{t\_1 - b\_2}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b\_2 + t\_1}\\
\end{array}
\end{array}
herbie shell --seed 2024250
(FPCore (a b_2 c)
:name "quad2p (problem 3.2.1, positive)"
:precision binary64
:herbie-expected 10
:alt
(! :herbie-platform default (let ((sqtD (let ((x (* (sqrt (fabs a)) (sqrt (fabs c))))) (if (== (copysign a c) a) (* (sqrt (- (fabs b_2) x)) (sqrt (+ (fabs b_2) x))) (hypot b_2 x))))) (if (< b_2 0) (/ (- sqtD b_2) a) (/ (- c) (+ b_2 sqtD)))))
(/ (+ (- b_2) (sqrt (- (* b_2 b_2) (* a c)))) a))