
(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 6 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 -8.2e+45)
(- (/ c b) (/ b a))
(if (<= b 1.9e-126)
(/ (- (sqrt (- (* b b) (* c (* a 4.0)))) b) (* a 2.0))
(/ (- c) b))))
double code(double a, double b, double c) {
double tmp;
if (b <= -8.2e+45) {
tmp = (c / b) - (b / a);
} else if (b <= 1.9e-126) {
tmp = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
} 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 <= (-8.2d+45)) then
tmp = (c / b) - (b / a)
else if (b <= 1.9d-126) then
tmp = (sqrt(((b * b) - (c * (a * 4.0d0)))) - b) / (a * 2.0d0)
else
tmp = -c / b
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -8.2e+45) {
tmp = (c / b) - (b / a);
} else if (b <= 1.9e-126) {
tmp = (Math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -8.2e+45: tmp = (c / b) - (b / a) elif b <= 1.9e-126: tmp = (math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0) else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -8.2e+45) tmp = Float64(Float64(c / b) - Float64(b / a)); elseif (b <= 1.9e-126) tmp = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 4.0)))) - b) / Float64(a * 2.0)); else tmp = Float64(Float64(-c) / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -8.2e+45) tmp = (c / b) - (b / a); elseif (b <= 1.9e-126) tmp = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0); else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -8.2e+45], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 1.9e-126], N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(a * 4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[((-c) / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -8.2 \cdot 10^{+45}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{elif}\;b \leq 1.9 \cdot 10^{-126}:\\
\;\;\;\;\frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
if b < -8.20000000000000025e45Initial program 55.0%
neg-sub055.0%
associate-+l-55.0%
sub0-neg55.0%
neg-mul-155.0%
associate-*l/54.9%
*-commutative54.9%
associate-/r*54.9%
/-rgt-identity54.9%
metadata-eval54.9%
Simplified55.2%
Taylor expanded in b around -inf 96.5%
mul-1-neg96.5%
unsub-neg96.5%
Simplified96.5%
if -8.20000000000000025e45 < b < 1.8999999999999999e-126Initial program 84.9%
if 1.8999999999999999e-126 < b Initial program 21.4%
neg-sub021.4%
associate-+l-21.4%
sub0-neg21.4%
neg-mul-121.4%
associate-*l/21.4%
*-commutative21.4%
associate-/r*21.4%
/-rgt-identity21.4%
metadata-eval21.4%
Simplified21.4%
Taylor expanded in b around inf 84.7%
mul-1-neg84.7%
distribute-neg-frac84.7%
Simplified84.7%
Final simplification88.5%
(FPCore (a b c)
:precision binary64
(if (<= b -2.05e-72)
(- (/ c b) (/ b a))
(if (<= b 5e-127)
(* -0.5 (/ (- b (sqrt (* a (* c -4.0)))) a))
(/ (- c) b))))
double code(double a, double b, double c) {
double tmp;
if (b <= -2.05e-72) {
tmp = (c / b) - (b / a);
} else if (b <= 5e-127) {
tmp = -0.5 * ((b - sqrt((a * (c * -4.0)))) / 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 <= (-2.05d-72)) then
tmp = (c / b) - (b / a)
else if (b <= 5d-127) then
tmp = (-0.5d0) * ((b - sqrt((a * (c * (-4.0d0))))) / 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 <= -2.05e-72) {
tmp = (c / b) - (b / a);
} else if (b <= 5e-127) {
tmp = -0.5 * ((b - Math.sqrt((a * (c * -4.0)))) / a);
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -2.05e-72: tmp = (c / b) - (b / a) elif b <= 5e-127: tmp = -0.5 * ((b - math.sqrt((a * (c * -4.0)))) / a) else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -2.05e-72) tmp = Float64(Float64(c / b) - Float64(b / a)); elseif (b <= 5e-127) tmp = Float64(-0.5 * Float64(Float64(b - sqrt(Float64(a * Float64(c * -4.0)))) / a)); else tmp = Float64(Float64(-c) / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -2.05e-72) tmp = (c / b) - (b / a); elseif (b <= 5e-127) tmp = -0.5 * ((b - sqrt((a * (c * -4.0)))) / a); else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -2.05e-72], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 5e-127], N[(-0.5 * N[(N[(b - N[Sqrt[N[(a * N[(c * -4.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision], N[((-c) / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -2.05 \cdot 10^{-72}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{elif}\;b \leq 5 \cdot 10^{-127}:\\
\;\;\;\;-0.5 \cdot \frac{b - \sqrt{a \cdot \left(c \cdot -4\right)}}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
if b < -2.05000000000000002e-72Initial program 64.4%
neg-sub064.4%
associate-+l-64.4%
sub0-neg64.4%
neg-mul-164.4%
associate-*l/64.3%
*-commutative64.3%
associate-/r*64.3%
/-rgt-identity64.3%
metadata-eval64.3%
Simplified64.5%
Taylor expanded in b around -inf 91.3%
mul-1-neg91.3%
unsub-neg91.3%
Simplified91.3%
if -2.05000000000000002e-72 < b < 4.9999999999999997e-127Initial program 81.6%
neg-sub081.6%
associate-+l-81.6%
sub0-neg81.6%
neg-mul-181.6%
associate-*l/81.6%
*-commutative81.6%
associate-/r*81.6%
/-rgt-identity81.6%
metadata-eval81.6%
Simplified81.6%
fma-udef81.6%
*-commutative81.6%
associate-*r*81.6%
metadata-eval81.6%
distribute-rgt-neg-in81.6%
*-commutative81.6%
distribute-lft-neg-in81.6%
+-commutative81.6%
sub-neg81.6%
add-sqr-sqrt81.0%
pow281.0%
Applied egg-rr81.1%
Taylor expanded in a around inf 39.2%
Simplified75.6%
if 4.9999999999999997e-127 < b Initial program 21.4%
neg-sub021.4%
associate-+l-21.4%
sub0-neg21.4%
neg-mul-121.4%
associate-*l/21.4%
*-commutative21.4%
associate-/r*21.4%
/-rgt-identity21.4%
metadata-eval21.4%
Simplified21.4%
Taylor expanded in b around inf 84.7%
mul-1-neg84.7%
distribute-neg-frac84.7%
Simplified84.7%
Final simplification85.2%
(FPCore (a b c) :precision binary64 (if (<= b -2e-310) (- (/ c b) (/ b a)) (/ (- c) b)))
double code(double a, double b, double c) {
double tmp;
if (b <= -2e-310) {
tmp = (c / b) - (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 <= (-2d-310)) then
tmp = (c / b) - (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 <= -2e-310) {
tmp = (c / b) - (b / a);
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -2e-310: tmp = (c / b) - (b / a) else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -2e-310) tmp = Float64(Float64(c / b) - 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 <= -2e-310) tmp = (c / b) - (b / a); else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -2e-310], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], N[((-c) / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -2 \cdot 10^{-310}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
if b < -1.999999999999994e-310Initial program 70.0%
neg-sub070.0%
associate-+l-70.0%
sub0-neg70.0%
neg-mul-170.0%
associate-*l/69.9%
*-commutative69.9%
associate-/r*69.9%
/-rgt-identity69.9%
metadata-eval69.9%
Simplified70.0%
Taylor expanded in b around -inf 71.6%
mul-1-neg71.6%
unsub-neg71.6%
Simplified71.6%
if -1.999999999999994e-310 < b Initial program 34.5%
neg-sub034.5%
associate-+l-34.5%
sub0-neg34.5%
neg-mul-134.5%
associate-*l/34.4%
*-commutative34.4%
associate-/r*34.4%
/-rgt-identity34.4%
metadata-eval34.4%
Simplified34.4%
Taylor expanded in b around inf 66.2%
mul-1-neg66.2%
distribute-neg-frac66.2%
Simplified66.2%
Final simplification69.3%
(FPCore (a b c) :precision binary64 (if (<= b -2e-310) (/ (- b) a) (/ (- c) b)))
double code(double a, double b, double c) {
double tmp;
if (b <= -2e-310) {
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 <= (-2d-310)) 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 <= -2e-310) {
tmp = -b / a;
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -2e-310: tmp = -b / a else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -2e-310) 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 <= -2e-310) tmp = -b / a; else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -2e-310], N[((-b) / a), $MachinePrecision], N[((-c) / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -2 \cdot 10^{-310}:\\
\;\;\;\;\frac{-b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
if b < -1.999999999999994e-310Initial program 70.0%
neg-sub070.0%
associate-+l-70.0%
sub0-neg70.0%
neg-mul-170.0%
associate-*l/69.9%
*-commutative69.9%
associate-/r*69.9%
/-rgt-identity69.9%
metadata-eval69.9%
Simplified70.0%
Taylor expanded in b around -inf 71.4%
associate-*r/71.4%
mul-1-neg71.4%
Simplified71.4%
if -1.999999999999994e-310 < b Initial program 34.5%
neg-sub034.5%
associate-+l-34.5%
sub0-neg34.5%
neg-mul-134.5%
associate-*l/34.4%
*-commutative34.4%
associate-/r*34.4%
/-rgt-identity34.4%
metadata-eval34.4%
Simplified34.4%
Taylor expanded in b around inf 66.2%
mul-1-neg66.2%
distribute-neg-frac66.2%
Simplified66.2%
Final simplification69.2%
(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(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 54.9%
neg-sub054.9%
associate-+l-54.9%
sub0-neg54.9%
neg-mul-154.9%
associate-*l/54.8%
*-commutative54.8%
associate-/r*54.8%
/-rgt-identity54.8%
metadata-eval54.8%
Simplified54.8%
Taylor expanded in b around -inf 42.2%
associate-*r/42.2%
mul-1-neg42.2%
Simplified42.2%
Final simplification42.2%
(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 54.9%
neg-sub054.9%
associate-+l-54.9%
sub0-neg54.9%
neg-mul-154.9%
associate-*l/54.8%
*-commutative54.8%
associate-/r*54.8%
/-rgt-identity54.8%
metadata-eval54.8%
Simplified54.8%
associate-*r/54.9%
clear-num54.9%
Applied egg-rr54.9%
Taylor expanded in a around 0 29.7%
mul-1-neg29.7%
unsub-neg29.7%
Simplified29.7%
Taylor expanded in a around inf 2.4%
Final simplification2.4%
herbie shell --seed 2023187
(FPCore (a b c)
:name "Quadratic roots, full range"
:precision binary64
(/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))