
(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 -9e-115)
(* -0.5 (/ c b_2))
(if (<= b_2 1.25e+22)
(/ (- (- b_2) (sqrt (- (* b_2 b_2) (* c a)))) a)
(+ (* -2.0 (/ b_2 a)) (* (/ c b_2) 0.5)))))
double code(double a, double b_2, double c) {
double tmp;
if (b_2 <= -9e-115) {
tmp = -0.5 * (c / b_2);
} else if (b_2 <= 1.25e+22) {
tmp = (-b_2 - sqrt(((b_2 * b_2) - (c * a)))) / a;
} else {
tmp = (-2.0 * (b_2 / a)) + ((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 <= (-9d-115)) then
tmp = (-0.5d0) * (c / b_2)
else if (b_2 <= 1.25d+22) then
tmp = (-b_2 - sqrt(((b_2 * b_2) - (c * a)))) / a
else
tmp = ((-2.0d0) * (b_2 / a)) + ((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 <= -9e-115) {
tmp = -0.5 * (c / b_2);
} else if (b_2 <= 1.25e+22) {
tmp = (-b_2 - Math.sqrt(((b_2 * b_2) - (c * a)))) / a;
} else {
tmp = (-2.0 * (b_2 / a)) + ((c / b_2) * 0.5);
}
return tmp;
}
def code(a, b_2, c): tmp = 0 if b_2 <= -9e-115: tmp = -0.5 * (c / b_2) elif b_2 <= 1.25e+22: tmp = (-b_2 - math.sqrt(((b_2 * b_2) - (c * a)))) / a else: tmp = (-2.0 * (b_2 / a)) + ((c / b_2) * 0.5) return tmp
function code(a, b_2, c) tmp = 0.0 if (b_2 <= -9e-115) tmp = Float64(-0.5 * Float64(c / b_2)); elseif (b_2 <= 1.25e+22) tmp = Float64(Float64(Float64(-b_2) - sqrt(Float64(Float64(b_2 * b_2) - Float64(c * a)))) / a); else tmp = Float64(Float64(-2.0 * Float64(b_2 / a)) + 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 <= -9e-115) tmp = -0.5 * (c / b_2); elseif (b_2 <= 1.25e+22) tmp = (-b_2 - sqrt(((b_2 * b_2) - (c * a)))) / a; else tmp = (-2.0 * (b_2 / a)) + ((c / b_2) * 0.5); end tmp_2 = tmp; end
code[a_, b$95$2_, c_] := If[LessEqual[b$95$2, -9e-115], N[(-0.5 * N[(c / b$95$2), $MachinePrecision]), $MachinePrecision], If[LessEqual[b$95$2, 1.25e+22], N[(N[((-b$95$2) - N[Sqrt[N[(N[(b$95$2 * b$95$2), $MachinePrecision] - N[(c * a), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision], N[(N[(-2.0 * N[(b$95$2 / a), $MachinePrecision]), $MachinePrecision] + N[(N[(c / b$95$2), $MachinePrecision] * 0.5), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b_2 \leq -9 \cdot 10^{-115}:\\
\;\;\;\;-0.5 \cdot \frac{c}{b_2}\\
\mathbf{elif}\;b_2 \leq 1.25 \cdot 10^{+22}:\\
\;\;\;\;\frac{\left(-b_2\right) - \sqrt{b_2 \cdot b_2 - c \cdot a}}{a}\\
\mathbf{else}:\\
\;\;\;\;-2 \cdot \frac{b_2}{a} + \frac{c}{b_2} \cdot 0.5\\
\end{array}
\end{array}
if b_2 < -9.00000000000000046e-115Initial program 20.2%
Taylor expanded in b_2 around -inf 86.5%
if -9.00000000000000046e-115 < b_2 < 1.2499999999999999e22Initial program 86.7%
if 1.2499999999999999e22 < b_2 Initial program 62.8%
Taylor expanded in b_2 around inf 96.6%
Final simplification89.8%
(FPCore (a b_2 c)
:precision binary64
(if (<= b_2 -3.5e-106)
(* -0.5 (/ c b_2))
(if (<= b_2 1.95e-88)
(/ (- (- b_2) (sqrt (* a (- c)))) a)
(* -2.0 (/ b_2 a)))))
double code(double a, double b_2, double c) {
double tmp;
if (b_2 <= -3.5e-106) {
tmp = -0.5 * (c / b_2);
} else if (b_2 <= 1.95e-88) {
tmp = (-b_2 - sqrt((a * -c))) / a;
} else {
tmp = -2.0 * (b_2 / a);
}
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 <= (-3.5d-106)) then
tmp = (-0.5d0) * (c / b_2)
else if (b_2 <= 1.95d-88) then
tmp = (-b_2 - sqrt((a * -c))) / a
else
tmp = (-2.0d0) * (b_2 / a)
end if
code = tmp
end function
public static double code(double a, double b_2, double c) {
double tmp;
if (b_2 <= -3.5e-106) {
tmp = -0.5 * (c / b_2);
} else if (b_2 <= 1.95e-88) {
tmp = (-b_2 - Math.sqrt((a * -c))) / a;
} else {
tmp = -2.0 * (b_2 / a);
}
return tmp;
}
def code(a, b_2, c): tmp = 0 if b_2 <= -3.5e-106: tmp = -0.5 * (c / b_2) elif b_2 <= 1.95e-88: tmp = (-b_2 - math.sqrt((a * -c))) / a else: tmp = -2.0 * (b_2 / a) return tmp
function code(a, b_2, c) tmp = 0.0 if (b_2 <= -3.5e-106) tmp = Float64(-0.5 * Float64(c / b_2)); elseif (b_2 <= 1.95e-88) tmp = Float64(Float64(Float64(-b_2) - sqrt(Float64(a * Float64(-c)))) / a); else tmp = Float64(-2.0 * Float64(b_2 / a)); end return tmp end
function tmp_2 = code(a, b_2, c) tmp = 0.0; if (b_2 <= -3.5e-106) tmp = -0.5 * (c / b_2); elseif (b_2 <= 1.95e-88) tmp = (-b_2 - sqrt((a * -c))) / a; else tmp = -2.0 * (b_2 / a); end tmp_2 = tmp; end
code[a_, b$95$2_, c_] := If[LessEqual[b$95$2, -3.5e-106], N[(-0.5 * N[(c / b$95$2), $MachinePrecision]), $MachinePrecision], If[LessEqual[b$95$2, 1.95e-88], N[(N[((-b$95$2) - N[Sqrt[N[(a * (-c)), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision], N[(-2.0 * N[(b$95$2 / a), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b_2 \leq -3.5 \cdot 10^{-106}:\\
\;\;\;\;-0.5 \cdot \frac{c}{b_2}\\
\mathbf{elif}\;b_2 \leq 1.95 \cdot 10^{-88}:\\
\;\;\;\;\frac{\left(-b_2\right) - \sqrt{a \cdot \left(-c\right)}}{a}\\
\mathbf{else}:\\
\;\;\;\;-2 \cdot \frac{b_2}{a}\\
\end{array}
\end{array}
if b_2 < -3.5e-106Initial program 20.5%
Taylor expanded in b_2 around -inf 87.6%
if -3.5e-106 < b_2 < 1.94999999999999996e-88Initial program 83.7%
Taylor expanded in b_2 around 0 82.5%
associate-*r*82.5%
neg-mul-182.5%
Simplified82.5%
if 1.94999999999999996e-88 < b_2 Initial program 68.9%
Taylor expanded in b_2 around inf 90.7%
Final simplification87.2%
(FPCore (a b_2 c) :precision binary64 (if (<= b_2 -4.9e-296) (* -0.5 (/ c b_2)) (* -2.0 (/ b_2 a))))
double code(double a, double b_2, double c) {
double tmp;
if (b_2 <= -4.9e-296) {
tmp = -0.5 * (c / b_2);
} else {
tmp = -2.0 * (b_2 / a);
}
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 <= (-4.9d-296)) then
tmp = (-0.5d0) * (c / b_2)
else
tmp = (-2.0d0) * (b_2 / a)
end if
code = tmp
end function
public static double code(double a, double b_2, double c) {
double tmp;
if (b_2 <= -4.9e-296) {
tmp = -0.5 * (c / b_2);
} else {
tmp = -2.0 * (b_2 / a);
}
return tmp;
}
def code(a, b_2, c): tmp = 0 if b_2 <= -4.9e-296: tmp = -0.5 * (c / b_2) else: tmp = -2.0 * (b_2 / a) return tmp
function code(a, b_2, c) tmp = 0.0 if (b_2 <= -4.9e-296) tmp = Float64(-0.5 * Float64(c / b_2)); else tmp = Float64(-2.0 * Float64(b_2 / a)); end return tmp end
function tmp_2 = code(a, b_2, c) tmp = 0.0; if (b_2 <= -4.9e-296) tmp = -0.5 * (c / b_2); else tmp = -2.0 * (b_2 / a); end tmp_2 = tmp; end
code[a_, b$95$2_, c_] := If[LessEqual[b$95$2, -4.9e-296], N[(-0.5 * N[(c / b$95$2), $MachinePrecision]), $MachinePrecision], N[(-2.0 * N[(b$95$2 / a), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b_2 \leq -4.9 \cdot 10^{-296}:\\
\;\;\;\;-0.5 \cdot \frac{c}{b_2}\\
\mathbf{else}:\\
\;\;\;\;-2 \cdot \frac{b_2}{a}\\
\end{array}
\end{array}
if b_2 < -4.8999999999999998e-296Initial program 40.3%
Taylor expanded in b_2 around -inf 63.2%
if -4.8999999999999998e-296 < b_2 Initial program 74.0%
Taylor expanded in b_2 around inf 67.4%
Final simplification65.6%
(FPCore (a b_2 c) :precision binary64 (* -2.0 (/ b_2 a)))
double code(double a, double b_2, double c) {
return -2.0 * (b_2 / 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 = (-2.0d0) * (b_2 / a)
end function
public static double code(double a, double b_2, double c) {
return -2.0 * (b_2 / a);
}
def code(a, b_2, c): return -2.0 * (b_2 / a)
function code(a, b_2, c) return Float64(-2.0 * Float64(b_2 / a)) end
function tmp = code(a, b_2, c) tmp = -2.0 * (b_2 / a); end
code[a_, b$95$2_, c_] := N[(-2.0 * N[(b$95$2 / a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
-2 \cdot \frac{b_2}{a}
\end{array}
Initial program 59.0%
Taylor expanded in b_2 around inf 38.6%
Final simplification38.6%
(FPCore (a b_2 c) :precision binary64 (/ (- b_2) a))
double code(double a, double b_2, double c) {
return -b_2 / 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 / a
end function
public static double code(double a, double b_2, double c) {
return -b_2 / a;
}
def code(a, b_2, c): return -b_2 / a
function code(a, b_2, c) return Float64(Float64(-b_2) / a) end
function tmp = code(a, b_2, c) tmp = -b_2 / a; end
code[a_, b$95$2_, c_] := N[((-b$95$2) / a), $MachinePrecision]
\begin{array}{l}
\\
\frac{-b_2}{a}
\end{array}
Initial program 59.0%
Taylor expanded in b_2 around 0 38.0%
associate-*r*38.0%
neg-mul-138.0%
Simplified38.0%
Taylor expanded in b_2 around inf 15.4%
associate-*r/15.4%
mul-1-neg15.4%
Simplified15.4%
Final simplification15.4%
(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) (/ c (- t_1 b_2)) (/ (+ b_2 t_1) (- a)))))
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 = c / (t_1 - b_2);
} else {
tmp_1 = (b_2 + t_1) / -a;
}
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 = c / (t_1 - b_2);
} else {
tmp_1 = (b_2 + t_1) / -a;
}
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 = c / (t_1 - b_2) else: tmp_1 = (b_2 + t_1) / -a 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(c / Float64(t_1 - b_2)); else tmp_1 = Float64(Float64(b_2 + t_1) / Float64(-a)); 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 = c / (t_1 - b_2); else tmp_2 = (b_2 + t_1) / -a; 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[(c / N[(t$95$1 - b$95$2), $MachinePrecision]), $MachinePrecision], N[(N[(b$95$2 + t$95$1), $MachinePrecision] / (-a)), $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{c}{t_1 - b_2}\\
\mathbf{else}:\\
\;\;\;\;\frac{b_2 + t_1}{-a}\\
\end{array}
\end{array}
herbie shell --seed 2023336
(FPCore (a b_2 c)
:name "quad2m (problem 3.2.1, negative)"
:precision binary64
:herbie-expected 10
:herbie-target
(if (< b_2 0.0) (/ c (- (if (== (copysign a c) a) (* (sqrt (- (fabs b_2) (* (sqrt (fabs a)) (sqrt (fabs c))))) (sqrt (+ (fabs b_2) (* (sqrt (fabs a)) (sqrt (fabs c)))))) (hypot b_2 (* (sqrt (fabs a)) (sqrt (fabs c))))) b_2)) (/ (+ b_2 (if (== (copysign a c) a) (* (sqrt (- (fabs b_2) (* (sqrt (fabs a)) (sqrt (fabs c))))) (sqrt (+ (fabs b_2) (* (sqrt (fabs a)) (sqrt (fabs c)))))) (hypot b_2 (* (sqrt (fabs a)) (sqrt (fabs c)))))) (- a)))
(/ (- (- b_2) (sqrt (- (* b_2 b_2) (* a c)))) a))