
(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 -1.22e+60)
(/ (* b_2 -2.0) a)
(if (<= b_2 1.45e-58)
(/ (- (sqrt (- (* b_2 b_2) (* a c))) b_2) a)
(/ (* c -0.5) b_2))))
double code(double a, double b_2, double c) {
double tmp;
if (b_2 <= -1.22e+60) {
tmp = (b_2 * -2.0) / a;
} else if (b_2 <= 1.45e-58) {
tmp = (sqrt(((b_2 * b_2) - (a * c))) - b_2) / a;
} else {
tmp = (c * -0.5) / 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 <= (-1.22d+60)) then
tmp = (b_2 * (-2.0d0)) / a
else if (b_2 <= 1.45d-58) then
tmp = (sqrt(((b_2 * b_2) - (a * c))) - b_2) / a
else
tmp = (c * (-0.5d0)) / b_2
end if
code = tmp
end function
public static double code(double a, double b_2, double c) {
double tmp;
if (b_2 <= -1.22e+60) {
tmp = (b_2 * -2.0) / a;
} else if (b_2 <= 1.45e-58) {
tmp = (Math.sqrt(((b_2 * b_2) - (a * c))) - b_2) / a;
} else {
tmp = (c * -0.5) / b_2;
}
return tmp;
}
def code(a, b_2, c): tmp = 0 if b_2 <= -1.22e+60: tmp = (b_2 * -2.0) / a elif b_2 <= 1.45e-58: tmp = (math.sqrt(((b_2 * b_2) - (a * c))) - b_2) / a else: tmp = (c * -0.5) / b_2 return tmp
function code(a, b_2, c) tmp = 0.0 if (b_2 <= -1.22e+60) tmp = Float64(Float64(b_2 * -2.0) / a); elseif (b_2 <= 1.45e-58) tmp = Float64(Float64(sqrt(Float64(Float64(b_2 * b_2) - Float64(a * c))) - b_2) / a); else tmp = Float64(Float64(c * -0.5) / b_2); end return tmp end
function tmp_2 = code(a, b_2, c) tmp = 0.0; if (b_2 <= -1.22e+60) tmp = (b_2 * -2.0) / a; elseif (b_2 <= 1.45e-58) tmp = (sqrt(((b_2 * b_2) - (a * c))) - b_2) / a; else tmp = (c * -0.5) / b_2; end tmp_2 = tmp; end
code[a_, b$95$2_, c_] := If[LessEqual[b$95$2, -1.22e+60], N[(N[(b$95$2 * -2.0), $MachinePrecision] / a), $MachinePrecision], If[LessEqual[b$95$2, 1.45e-58], N[(N[(N[Sqrt[N[(N[(b$95$2 * b$95$2), $MachinePrecision] - N[(a * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b$95$2), $MachinePrecision] / a), $MachinePrecision], N[(N[(c * -0.5), $MachinePrecision] / b$95$2), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b\_2 \leq -1.22 \cdot 10^{+60}:\\
\;\;\;\;\frac{b\_2 \cdot -2}{a}\\
\mathbf{elif}\;b\_2 \leq 1.45 \cdot 10^{-58}:\\
\;\;\;\;\frac{\sqrt{b\_2 \cdot b\_2 - a \cdot c} - b\_2}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{c \cdot -0.5}{b\_2}\\
\end{array}
\end{array}
if b_2 < -1.21999999999999995e60Initial program 53.0%
Taylor expanded in b_2 around -inf
*-commutativeN/A
lower-*.f6497.6
Applied rewrites97.6%
if -1.21999999999999995e60 < b_2 < 1.44999999999999995e-58Initial program 79.4%
Applied rewrites34.2%
lift-neg.f64N/A
lift-+.f64N/A
+-commutativeN/A
unsub-negN/A
lower--.f6434.2
Applied rewrites79.4%
if 1.44999999999999995e-58 < b_2 Initial program 17.6%
Taylor expanded in b_2 around inf
associate-*r/N/A
*-commutativeN/A
associate-/l*N/A
metadata-evalN/A
distribute-neg-fracN/A
metadata-evalN/A
associate-*r/N/A
lower-*.f64N/A
associate-*r/N/A
metadata-evalN/A
distribute-neg-fracN/A
metadata-evalN/A
lower-/.f6482.5
Applied rewrites82.5%
Applied rewrites82.8%
Final simplification85.5%
(FPCore (a b_2 c) :precision binary64 (if (<= b_2 -1.9e-68) (/ (* b_2 -2.0) a) (if (<= b_2 7.6e-59) (/ (- (sqrt (- (* a c))) b_2) a) (/ (* c -0.5) b_2))))
double code(double a, double b_2, double c) {
double tmp;
if (b_2 <= -1.9e-68) {
tmp = (b_2 * -2.0) / a;
} else if (b_2 <= 7.6e-59) {
tmp = (sqrt(-(a * c)) - b_2) / a;
} else {
tmp = (c * -0.5) / 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 <= (-1.9d-68)) then
tmp = (b_2 * (-2.0d0)) / a
else if (b_2 <= 7.6d-59) then
tmp = (sqrt(-(a * c)) - b_2) / a
else
tmp = (c * (-0.5d0)) / b_2
end if
code = tmp
end function
public static double code(double a, double b_2, double c) {
double tmp;
if (b_2 <= -1.9e-68) {
tmp = (b_2 * -2.0) / a;
} else if (b_2 <= 7.6e-59) {
tmp = (Math.sqrt(-(a * c)) - b_2) / a;
} else {
tmp = (c * -0.5) / b_2;
}
return tmp;
}
def code(a, b_2, c): tmp = 0 if b_2 <= -1.9e-68: tmp = (b_2 * -2.0) / a elif b_2 <= 7.6e-59: tmp = (math.sqrt(-(a * c)) - b_2) / a else: tmp = (c * -0.5) / b_2 return tmp
function code(a, b_2, c) tmp = 0.0 if (b_2 <= -1.9e-68) tmp = Float64(Float64(b_2 * -2.0) / a); elseif (b_2 <= 7.6e-59) tmp = Float64(Float64(sqrt(Float64(-Float64(a * c))) - b_2) / a); else tmp = Float64(Float64(c * -0.5) / b_2); end return tmp end
function tmp_2 = code(a, b_2, c) tmp = 0.0; if (b_2 <= -1.9e-68) tmp = (b_2 * -2.0) / a; elseif (b_2 <= 7.6e-59) tmp = (sqrt(-(a * c)) - b_2) / a; else tmp = (c * -0.5) / b_2; end tmp_2 = tmp; end
code[a_, b$95$2_, c_] := If[LessEqual[b$95$2, -1.9e-68], N[(N[(b$95$2 * -2.0), $MachinePrecision] / a), $MachinePrecision], If[LessEqual[b$95$2, 7.6e-59], N[(N[(N[Sqrt[(-N[(a * c), $MachinePrecision])], $MachinePrecision] - b$95$2), $MachinePrecision] / a), $MachinePrecision], N[(N[(c * -0.5), $MachinePrecision] / b$95$2), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b\_2 \leq -1.9 \cdot 10^{-68}:\\
\;\;\;\;\frac{b\_2 \cdot -2}{a}\\
\mathbf{elif}\;b\_2 \leq 7.6 \cdot 10^{-59}:\\
\;\;\;\;\frac{\sqrt{-a \cdot c} - b\_2}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{c \cdot -0.5}{b\_2}\\
\end{array}
\end{array}
if b_2 < -1.90000000000000019e-68Initial program 63.1%
Taylor expanded in b_2 around -inf
*-commutativeN/A
lower-*.f6492.1
Applied rewrites92.1%
if -1.90000000000000019e-68 < b_2 < 7.59999999999999966e-59Initial program 73.9%
Taylor expanded in b_2 around 0
mul-1-negN/A
distribute-rgt-neg-inN/A
mul-1-negN/A
lower-*.f64N/A
mul-1-negN/A
lower-neg.f6468.0
Applied rewrites68.0%
if 7.59999999999999966e-59 < b_2 Initial program 17.6%
Taylor expanded in b_2 around inf
associate-*r/N/A
*-commutativeN/A
associate-/l*N/A
metadata-evalN/A
distribute-neg-fracN/A
metadata-evalN/A
associate-*r/N/A
lower-*.f64N/A
associate-*r/N/A
metadata-evalN/A
distribute-neg-fracN/A
metadata-evalN/A
lower-/.f6482.5
Applied rewrites82.5%
Applied rewrites82.8%
Final simplification82.0%
(FPCore (a b_2 c) :precision binary64 (if (<= b_2 9e-306) (/ (* b_2 -2.0) a) (/ (* c -0.5) b_2)))
double code(double a, double b_2, double c) {
double tmp;
if (b_2 <= 9e-306) {
tmp = (b_2 * -2.0) / a;
} else {
tmp = (c * -0.5) / 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 <= 9d-306) then
tmp = (b_2 * (-2.0d0)) / a
else
tmp = (c * (-0.5d0)) / b_2
end if
code = tmp
end function
public static double code(double a, double b_2, double c) {
double tmp;
if (b_2 <= 9e-306) {
tmp = (b_2 * -2.0) / a;
} else {
tmp = (c * -0.5) / b_2;
}
return tmp;
}
def code(a, b_2, c): tmp = 0 if b_2 <= 9e-306: tmp = (b_2 * -2.0) / a else: tmp = (c * -0.5) / b_2 return tmp
function code(a, b_2, c) tmp = 0.0 if (b_2 <= 9e-306) tmp = Float64(Float64(b_2 * -2.0) / a); else tmp = Float64(Float64(c * -0.5) / b_2); end return tmp end
function tmp_2 = code(a, b_2, c) tmp = 0.0; if (b_2 <= 9e-306) tmp = (b_2 * -2.0) / a; else tmp = (c * -0.5) / b_2; end tmp_2 = tmp; end
code[a_, b$95$2_, c_] := If[LessEqual[b$95$2, 9e-306], N[(N[(b$95$2 * -2.0), $MachinePrecision] / a), $MachinePrecision], N[(N[(c * -0.5), $MachinePrecision] / b$95$2), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b\_2 \leq 9 \cdot 10^{-306}:\\
\;\;\;\;\frac{b\_2 \cdot -2}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{c \cdot -0.5}{b\_2}\\
\end{array}
\end{array}
if b_2 < 9.00000000000000009e-306Initial program 68.2%
Taylor expanded in b_2 around -inf
*-commutativeN/A
lower-*.f6470.7
Applied rewrites70.7%
if 9.00000000000000009e-306 < b_2 Initial program 28.0%
Taylor expanded in b_2 around inf
associate-*r/N/A
*-commutativeN/A
associate-/l*N/A
metadata-evalN/A
distribute-neg-fracN/A
metadata-evalN/A
associate-*r/N/A
lower-*.f64N/A
associate-*r/N/A
metadata-evalN/A
distribute-neg-fracN/A
metadata-evalN/A
lower-/.f6468.7
Applied rewrites68.7%
Applied rewrites69.0%
(FPCore (a b_2 c) :precision binary64 (/ (* c -0.5) b_2))
double code(double a, double b_2, double c) {
return (c * -0.5) / b_2;
}
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 = (c * (-0.5d0)) / b_2
end function
public static double code(double a, double b_2, double c) {
return (c * -0.5) / b_2;
}
def code(a, b_2, c): return (c * -0.5) / b_2
function code(a, b_2, c) return Float64(Float64(c * -0.5) / b_2) end
function tmp = code(a, b_2, c) tmp = (c * -0.5) / b_2; end
code[a_, b$95$2_, c_] := N[(N[(c * -0.5), $MachinePrecision] / b$95$2), $MachinePrecision]
\begin{array}{l}
\\
\frac{c \cdot -0.5}{b\_2}
\end{array}
Initial program 46.9%
Taylor expanded in b_2 around inf
associate-*r/N/A
*-commutativeN/A
associate-/l*N/A
metadata-evalN/A
distribute-neg-fracN/A
metadata-evalN/A
associate-*r/N/A
lower-*.f64N/A
associate-*r/N/A
metadata-evalN/A
distribute-neg-fracN/A
metadata-evalN/A
lower-/.f6437.7
Applied rewrites37.7%
Applied rewrites37.8%
(FPCore (a b_2 c) :precision binary64 (* c (/ -0.5 b_2)))
double code(double a, double b_2, double c) {
return c * (-0.5 / b_2);
}
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 = c * ((-0.5d0) / b_2)
end function
public static double code(double a, double b_2, double c) {
return c * (-0.5 / b_2);
}
def code(a, b_2, c): return c * (-0.5 / b_2)
function code(a, b_2, c) return Float64(c * Float64(-0.5 / b_2)) end
function tmp = code(a, b_2, c) tmp = c * (-0.5 / b_2); end
code[a_, b$95$2_, c_] := N[(c * N[(-0.5 / b$95$2), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
c \cdot \frac{-0.5}{b\_2}
\end{array}
Initial program 46.9%
Taylor expanded in b_2 around inf
associate-*r/N/A
*-commutativeN/A
associate-/l*N/A
metadata-evalN/A
distribute-neg-fracN/A
metadata-evalN/A
associate-*r/N/A
lower-*.f64N/A
associate-*r/N/A
metadata-evalN/A
distribute-neg-fracN/A
metadata-evalN/A
lower-/.f6437.7
Applied rewrites37.7%
(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 2024223
(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))