
(FPCore (a b) :precision binary64 (sqrt (fabs (/ (- (* a a) (* b b)) (* a a)))))
double code(double a, double b) {
return sqrt(fabs((((a * a) - (b * b)) / (a * a))));
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
code = sqrt(abs((((a * a) - (b * b)) / (a * a))))
end function
public static double code(double a, double b) {
return Math.sqrt(Math.abs((((a * a) - (b * b)) / (a * a))));
}
def code(a, b): return math.sqrt(math.fabs((((a * a) - (b * b)) / (a * a))))
function code(a, b) return sqrt(abs(Float64(Float64(Float64(a * a) - Float64(b * b)) / Float64(a * a)))) end
function tmp = code(a, b) tmp = sqrt(abs((((a * a) - (b * b)) / (a * a)))); end
code[a_, b_] := N[Sqrt[N[Abs[N[(N[(N[(a * a), $MachinePrecision] - N[(b * b), $MachinePrecision]), $MachinePrecision] / N[(a * a), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{\left|\frac{a \cdot a - b \cdot b}{a \cdot a}\right|}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 3 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (a b) :precision binary64 (sqrt (fabs (/ (- (* a a) (* b b)) (* a a)))))
double code(double a, double b) {
return sqrt(fabs((((a * a) - (b * b)) / (a * a))));
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
code = sqrt(abs((((a * a) - (b * b)) / (a * a))))
end function
public static double code(double a, double b) {
return Math.sqrt(Math.abs((((a * a) - (b * b)) / (a * a))));
}
def code(a, b): return math.sqrt(math.fabs((((a * a) - (b * b)) / (a * a))))
function code(a, b) return sqrt(abs(Float64(Float64(Float64(a * a) - Float64(b * b)) / Float64(a * a)))) end
function tmp = code(a, b) tmp = sqrt(abs((((a * a) - (b * b)) / (a * a)))); end
code[a_, b_] := N[Sqrt[N[Abs[N[(N[(N[(a * a), $MachinePrecision] - N[(b * b), $MachinePrecision]), $MachinePrecision] / N[(a * a), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{\left|\frac{a \cdot a - b \cdot b}{a \cdot a}\right|}
\end{array}
(FPCore (a b) :precision binary64 (pow (- 1.0 (/ (/ b a) (/ a b))) 0.5))
double code(double a, double b) {
return pow((1.0 - ((b / a) / (a / b))), 0.5);
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
code = (1.0d0 - ((b / a) / (a / b))) ** 0.5d0
end function
public static double code(double a, double b) {
return Math.pow((1.0 - ((b / a) / (a / b))), 0.5);
}
def code(a, b): return math.pow((1.0 - ((b / a) / (a / b))), 0.5)
function code(a, b) return Float64(1.0 - Float64(Float64(b / a) / Float64(a / b))) ^ 0.5 end
function tmp = code(a, b) tmp = (1.0 - ((b / a) / (a / b))) ^ 0.5; end
code[a_, b_] := N[Power[N[(1.0 - N[(N[(b / a), $MachinePrecision] / N[(a / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 0.5], $MachinePrecision]
\begin{array}{l}
\\
{\left(1 - \frac{\frac{b}{a}}{\frac{a}{b}}\right)}^{0.5}
\end{array}
Initial program 79.6%
sqr-neg79.6%
fabs-div79.6%
sqr-neg79.6%
fabs-sub79.6%
sqr-neg79.6%
distribute-rgt-neg-out79.6%
fabs-neg79.6%
fabs-div79.6%
cancel-sign-sub-inv79.6%
+-commutative79.6%
sqr-neg79.6%
cancel-sign-sub-inv79.6%
Simplified80.3%
associate-*r/79.6%
frac-times100.0%
clear-num100.0%
un-div-inv100.0%
Applied egg-rr100.0%
pow1/2100.0%
add-sqr-sqrt100.0%
fabs-sqr100.0%
add-sqr-sqrt100.0%
div-inv100.0%
clear-num100.0%
pow2100.0%
Applied egg-rr100.0%
unpow2100.0%
clear-num100.0%
un-div-inv100.0%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (a b) :precision binary64 (fma -0.5 (/ (/ b a) (/ a b)) 1.0))
double code(double a, double b) {
return fma(-0.5, ((b / a) / (a / b)), 1.0);
}
function code(a, b) return fma(-0.5, Float64(Float64(b / a) / Float64(a / b)), 1.0) end
code[a_, b_] := N[(-0.5 * N[(N[(b / a), $MachinePrecision] / N[(a / b), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-0.5, \frac{\frac{b}{a}}{\frac{a}{b}}, 1\right)
\end{array}
Initial program 79.6%
sqr-neg79.6%
fabs-div79.6%
sqr-neg79.6%
fabs-sub79.6%
sqr-neg79.6%
distribute-rgt-neg-out79.6%
fabs-neg79.6%
fabs-div79.6%
cancel-sign-sub-inv79.6%
+-commutative79.6%
sqr-neg79.6%
cancel-sign-sub-inv79.6%
Simplified80.3%
associate-*r/79.6%
frac-times100.0%
clear-num100.0%
un-div-inv100.0%
Applied egg-rr100.0%
pow1/2100.0%
add-sqr-sqrt100.0%
fabs-sqr100.0%
add-sqr-sqrt100.0%
div-inv100.0%
clear-num100.0%
pow2100.0%
Applied egg-rr100.0%
Taylor expanded in b around 0 78.9%
+-commutative78.9%
fma-define78.9%
unpow278.9%
unpow278.9%
times-frac99.2%
unpow299.2%
Simplified99.2%
unpow2100.0%
clear-num100.0%
un-div-inv100.0%
Applied egg-rr99.2%
Final simplification99.2%
(FPCore (a b) :precision binary64 1.0)
double code(double a, double b) {
return 1.0;
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
code = 1.0d0
end function
public static double code(double a, double b) {
return 1.0;
}
def code(a, b): return 1.0
function code(a, b) return 1.0 end
function tmp = code(a, b) tmp = 1.0; end
code[a_, b_] := 1.0
\begin{array}{l}
\\
1
\end{array}
Initial program 79.6%
sqr-neg79.6%
fabs-div79.6%
sqr-neg79.6%
fabs-sub79.6%
sqr-neg79.6%
distribute-rgt-neg-out79.6%
fabs-neg79.6%
fabs-div79.6%
cancel-sign-sub-inv79.6%
+-commutative79.6%
sqr-neg79.6%
cancel-sign-sub-inv79.6%
Simplified80.3%
associate-*r/79.6%
frac-times100.0%
clear-num100.0%
un-div-inv100.0%
Applied egg-rr100.0%
pow1/2100.0%
add-sqr-sqrt100.0%
fabs-sqr100.0%
add-sqr-sqrt100.0%
div-inv100.0%
clear-num100.0%
pow2100.0%
Applied egg-rr100.0%
Taylor expanded in b around 0 98.7%
Final simplification98.7%
herbie shell --seed 2024080
(FPCore (a b)
:name "Eccentricity of an ellipse"
:precision binary64
:pre (and (and (<= 0.0 b) (<= b a)) (<= a 1.0))
(sqrt (fabs (/ (- (* a a) (* b b)) (* a a)))))