
(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 (/ (/ (- (* 0.0 (+ b b)) (* c (* a 4.0))) (+ b (sqrt (fma b b (* (* c a) -4.0))))) (* a 2.0)))
double code(double a, double b, double c) {
return (((0.0 * (b + b)) - (c * (a * 4.0))) / (b + sqrt(fma(b, b, ((c * a) * -4.0))))) / (a * 2.0);
}
function code(a, b, c) return Float64(Float64(Float64(Float64(0.0 * Float64(b + b)) - Float64(c * Float64(a * 4.0))) / Float64(b + sqrt(fma(b, b, Float64(Float64(c * a) * -4.0))))) / Float64(a * 2.0)) end
code[a_, b_, c_] := N[(N[(N[(N[(0.0 * N[(b + b), $MachinePrecision]), $MachinePrecision] - N[(c * N[(a * 4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b + N[Sqrt[N[(b * b + N[(N[(c * a), $MachinePrecision] * -4.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{0 \cdot \left(b + b\right) - c \cdot \left(a \cdot 4\right)}{b + \sqrt{\mathsf{fma}\left(b, b, \left(c \cdot a\right) \cdot -4\right)}}}{a \cdot 2}
\end{array}
Initial program 54.6%
*-commutative54.6%
Simplified54.6%
add-cube-cbrt52.5%
pow352.5%
cbrt-prod51.6%
pow251.6%
Applied egg-rr51.6%
flip-+51.6%
pow251.6%
add-sqr-sqrt51.8%
pow-pow51.7%
pow1/352.4%
pow-pow56.3%
metadata-eval56.3%
metadata-eval56.3%
*-commutative56.3%
*-commutative56.3%
Applied egg-rr56.3%
associate--r-99.3%
unpow299.3%
unpow299.3%
difference-of-squares99.3%
remove-double-neg99.3%
distribute-neg-in99.3%
*-lft-identity99.3%
neg-mul-199.3%
distribute-rgt-in99.3%
metadata-eval99.3%
distribute-lft-neg-in99.3%
mul0-rgt99.3%
unpow299.3%
fma-neg99.3%
associate-*r*99.3%
*-commutative99.3%
distribute-rgt-neg-in99.3%
Simplified99.3%
Final simplification99.3%
(FPCore (a b c) :precision binary64 (if (<= b 24.0) (/ (- (sqrt (fma b b (* c (* a -4.0)))) b) (* a 2.0)) (/ (/ 1.0 b) (+ (/ a (pow b 2.0)) (/ -1.0 c)))))
double code(double a, double b, double c) {
double tmp;
if (b <= 24.0) {
tmp = (sqrt(fma(b, b, (c * (a * -4.0)))) - b) / (a * 2.0);
} else {
tmp = (1.0 / b) / ((a / pow(b, 2.0)) + (-1.0 / c));
}
return tmp;
}
function code(a, b, c) tmp = 0.0 if (b <= 24.0) tmp = Float64(Float64(sqrt(fma(b, b, Float64(c * Float64(a * -4.0)))) - b) / Float64(a * 2.0)); else tmp = Float64(Float64(1.0 / b) / Float64(Float64(a / (b ^ 2.0)) + Float64(-1.0 / c))); end return tmp end
code[a_, b_, c_] := If[LessEqual[b, 24.0], N[(N[(N[Sqrt[N[(b * b + N[(c * N[(a * -4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 / b), $MachinePrecision] / N[(N[(a / N[Power[b, 2.0], $MachinePrecision]), $MachinePrecision] + N[(-1.0 / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 24:\\
\;\;\;\;\frac{\sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -4\right)\right)} - b}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{\frac{1}{b}}{\frac{a}{{b}^{2}} + \frac{-1}{c}}\\
\end{array}
\end{array}
if b < 24Initial program 80.0%
*-commutative80.0%
+-commutative80.0%
sqr-neg80.0%
unsub-neg80.0%
sqr-neg80.0%
fma-neg80.1%
distribute-lft-neg-in80.1%
*-commutative80.1%
*-commutative80.1%
distribute-rgt-neg-in80.1%
metadata-eval80.1%
Simplified80.1%
if 24 < b Initial program 44.8%
*-commutative44.8%
Simplified44.8%
Taylor expanded in b around inf 88.4%
mul-1-neg88.4%
unsub-neg88.4%
mul-1-neg88.4%
associate-/l*88.4%
Simplified88.4%
clear-num88.2%
inv-pow88.2%
div-inv88.2%
pow-flip88.2%
metadata-eval88.2%
Applied egg-rr88.2%
Taylor expanded in b around inf 88.7%
*-un-lft-identity88.7%
unpow-188.7%
Applied egg-rr88.7%
*-lft-identity88.7%
associate-/r*88.8%
sub-neg88.8%
distribute-neg-frac88.8%
metadata-eval88.8%
Simplified88.8%
(FPCore (a b c) :precision binary64 (if (<= b 4.8) (/ (- (sqrt (- (* b b) (* c (* a 4.0)))) b) (* a 2.0)) (/ (/ 1.0 b) (+ (/ a (pow b 2.0)) (/ -1.0 c)))))
double code(double a, double b, double c) {
double tmp;
if (b <= 4.8) {
tmp = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
} else {
tmp = (1.0 / b) / ((a / pow(b, 2.0)) + (-1.0 / c));
}
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 <= 4.8d0) then
tmp = (sqrt(((b * b) - (c * (a * 4.0d0)))) - b) / (a * 2.0d0)
else
tmp = (1.0d0 / b) / ((a / (b ** 2.0d0)) + ((-1.0d0) / c))
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= 4.8) {
tmp = (Math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
} else {
tmp = (1.0 / b) / ((a / Math.pow(b, 2.0)) + (-1.0 / c));
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= 4.8: tmp = (math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0) else: tmp = (1.0 / b) / ((a / math.pow(b, 2.0)) + (-1.0 / c)) return tmp
function code(a, b, c) tmp = 0.0 if (b <= 4.8) tmp = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 4.0)))) - b) / Float64(a * 2.0)); else tmp = Float64(Float64(1.0 / b) / Float64(Float64(a / (b ^ 2.0)) + Float64(-1.0 / c))); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= 4.8) tmp = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0); else tmp = (1.0 / b) / ((a / (b ^ 2.0)) + (-1.0 / c)); end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, 4.8], 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[(N[(1.0 / b), $MachinePrecision] / N[(N[(a / N[Power[b, 2.0], $MachinePrecision]), $MachinePrecision] + N[(-1.0 / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 4.8:\\
\;\;\;\;\frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{\frac{1}{b}}{\frac{a}{{b}^{2}} + \frac{-1}{c}}\\
\end{array}
\end{array}
if b < 4.79999999999999982Initial program 81.4%
if 4.79999999999999982 < b Initial program 46.5%
*-commutative46.5%
Simplified46.5%
Taylor expanded in b around inf 87.5%
mul-1-neg87.5%
unsub-neg87.5%
mul-1-neg87.5%
associate-/l*87.5%
Simplified87.5%
clear-num87.3%
inv-pow87.3%
div-inv87.3%
pow-flip87.3%
metadata-eval87.3%
Applied egg-rr87.3%
Taylor expanded in b around inf 87.8%
*-un-lft-identity87.8%
unpow-187.8%
Applied egg-rr87.8%
*-lft-identity87.8%
associate-/r*87.9%
sub-neg87.9%
distribute-neg-frac87.9%
metadata-eval87.9%
Simplified87.9%
Final simplification86.4%
(FPCore (a b c) :precision binary64 (/ (/ 1.0 b) (+ (/ a (pow b 2.0)) (/ -1.0 c))))
double code(double a, double b, double c) {
return (1.0 / b) / ((a / pow(b, 2.0)) + (-1.0 / c));
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = (1.0d0 / b) / ((a / (b ** 2.0d0)) + ((-1.0d0) / c))
end function
public static double code(double a, double b, double c) {
return (1.0 / b) / ((a / Math.pow(b, 2.0)) + (-1.0 / c));
}
def code(a, b, c): return (1.0 / b) / ((a / math.pow(b, 2.0)) + (-1.0 / c))
function code(a, b, c) return Float64(Float64(1.0 / b) / Float64(Float64(a / (b ^ 2.0)) + Float64(-1.0 / c))) end
function tmp = code(a, b, c) tmp = (1.0 / b) / ((a / (b ^ 2.0)) + (-1.0 / c)); end
code[a_, b_, c_] := N[(N[(1.0 / b), $MachinePrecision] / N[(N[(a / N[Power[b, 2.0], $MachinePrecision]), $MachinePrecision] + N[(-1.0 / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{1}{b}}{\frac{a}{{b}^{2}} + \frac{-1}{c}}
\end{array}
Initial program 54.6%
*-commutative54.6%
Simplified54.6%
Taylor expanded in b around inf 81.3%
mul-1-neg81.3%
unsub-neg81.3%
mul-1-neg81.3%
associate-/l*81.3%
Simplified81.3%
clear-num81.1%
inv-pow81.1%
div-inv81.1%
pow-flip81.1%
metadata-eval81.1%
Applied egg-rr81.1%
Taylor expanded in b around inf 81.8%
*-un-lft-identity81.8%
unpow-181.8%
Applied egg-rr81.8%
*-lft-identity81.8%
associate-/r*81.9%
sub-neg81.9%
distribute-neg-frac81.9%
metadata-eval81.9%
Simplified81.9%
(FPCore (a b c) :precision binary64 (pow (- (/ a b) (/ b c)) -1.0))
double code(double a, double b, double c) {
return pow(((a / b) - (b / c)), -1.0);
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = ((a / b) - (b / c)) ** (-1.0d0)
end function
public static double code(double a, double b, double c) {
return Math.pow(((a / b) - (b / c)), -1.0);
}
def code(a, b, c): return math.pow(((a / b) - (b / c)), -1.0)
function code(a, b, c) return Float64(Float64(a / b) - Float64(b / c)) ^ -1.0 end
function tmp = code(a, b, c) tmp = ((a / b) - (b / c)) ^ -1.0; end
code[a_, b_, c_] := N[Power[N[(N[(a / b), $MachinePrecision] - N[(b / c), $MachinePrecision]), $MachinePrecision], -1.0], $MachinePrecision]
\begin{array}{l}
\\
{\left(\frac{a}{b} - \frac{b}{c}\right)}^{-1}
\end{array}
Initial program 54.6%
*-commutative54.6%
Simplified54.6%
Taylor expanded in b around inf 81.3%
mul-1-neg81.3%
unsub-neg81.3%
mul-1-neg81.3%
associate-/l*81.3%
Simplified81.3%
clear-num81.1%
inv-pow81.1%
div-inv81.1%
pow-flip81.1%
metadata-eval81.1%
Applied egg-rr81.1%
Taylor expanded in a around 0 81.9%
+-commutative81.9%
mul-1-neg81.9%
unsub-neg81.9%
Simplified81.9%
(FPCore (a b c) :precision binary64 (/ c (- b)))
double code(double a, double b, double c) {
return c / -b;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = c / -b
end function
public static double code(double a, double b, double c) {
return c / -b;
}
def code(a, b, c): return c / -b
function code(a, b, c) return Float64(c / Float64(-b)) end
function tmp = code(a, b, c) tmp = c / -b; end
code[a_, b_, c_] := N[(c / (-b)), $MachinePrecision]
\begin{array}{l}
\\
\frac{c}{-b}
\end{array}
Initial program 54.6%
*-commutative54.6%
Simplified54.6%
Taylor expanded in b around inf 64.5%
associate-*r/64.5%
mul-1-neg64.5%
Simplified64.5%
Final simplification64.5%
(FPCore (a b c) :precision binary64 0.0)
double code(double a, double b, double c) {
return 0.0;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = 0.0d0
end function
public static double code(double a, double b, double c) {
return 0.0;
}
def code(a, b, c): return 0.0
function code(a, b, c) return 0.0 end
function tmp = code(a, b, c) tmp = 0.0; end
code[a_, b_, c_] := 0.0
\begin{array}{l}
\\
0
\end{array}
Initial program 54.6%
*-commutative54.6%
Simplified54.6%
Taylor expanded in b around inf 64.5%
associate-*r/64.5%
mul-1-neg64.5%
Simplified64.5%
div-inv64.4%
Applied egg-rr64.4%
expm1-log1p-u56.1%
expm1-undefine42.4%
distribute-lft-neg-out42.4%
div-inv42.4%
Applied egg-rr42.4%
sub-neg42.4%
log1p-undefine42.4%
rem-exp-log50.7%
unsub-neg50.7%
metadata-eval50.7%
Simplified50.7%
Taylor expanded in c around 0 3.2%
Final simplification3.2%
herbie shell --seed 2024114
(FPCore (a b c)
:name "Quadratic roots, narrow range"
:precision binary64
:pre (and (and (and (< 1.0536712127723509e-8 a) (< a 94906265.62425156)) (and (< 1.0536712127723509e-8 b) (< b 94906265.62425156))) (and (< 1.0536712127723509e-8 c) (< c 94906265.62425156)))
(/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))