
(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 (exp (* (log1p (- (pow (/ b a) 2.0))) 0.5)))
double code(double a, double b) {
return exp((log1p(-pow((b / a), 2.0)) * 0.5));
}
public static double code(double a, double b) {
return Math.exp((Math.log1p(-Math.pow((b / a), 2.0)) * 0.5));
}
def code(a, b): return math.exp((math.log1p(-math.pow((b / a), 2.0)) * 0.5))
function code(a, b) return exp(Float64(log1p(Float64(-(Float64(b / a) ^ 2.0))) * 0.5)) end
code[a_, b_] := N[Exp[N[(N[Log[1 + (-N[Power[N[(b / a), $MachinePrecision], 2.0], $MachinePrecision])], $MachinePrecision] * 0.5), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
e^{\mathsf{log1p}\left(-{\left(\frac{b}{a}\right)}^{2}\right) \cdot 0.5}
\end{array}
Initial program 79.7%
sqr-neg79.7%
fabs-div79.7%
sqr-neg79.7%
fabs-sub79.7%
sqr-neg79.7%
distribute-rgt-neg-out79.7%
fabs-neg79.7%
fabs-div79.7%
cancel-sign-sub-inv79.7%
+-commutative79.7%
sqr-neg79.7%
cancel-sign-sub-inv79.7%
Simplified80.3%
pow1/280.3%
pow-to-exp80.3%
add-sqr-sqrt79.7%
fabs-sqr79.7%
add-sqr-sqrt79.7%
sub-neg79.7%
log1p-define79.7%
associate-*r/79.7%
frac-times100.0%
pow2100.0%
Applied egg-rr100.0%
(FPCore (a b) :precision binary64 (sqrt (- 1.0 (/ (/ b a) (/ a b)))))
double code(double a, double b) {
return sqrt((1.0 - ((b / a) / (a / b))));
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
code = sqrt((1.0d0 - ((b / a) / (a / b))))
end function
public static double code(double a, double b) {
return Math.sqrt((1.0 - ((b / a) / (a / b))));
}
def code(a, b): return math.sqrt((1.0 - ((b / a) / (a / b))))
function code(a, b) return sqrt(Float64(1.0 - Float64(Float64(b / a) / Float64(a / b)))) end
function tmp = code(a, b) tmp = sqrt((1.0 - ((b / a) / (a / b)))); end
code[a_, b_] := N[Sqrt[N[(1.0 - N[(N[(b / a), $MachinePrecision] / N[(a / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{1 - \frac{\frac{b}{a}}{\frac{a}{b}}}
\end{array}
Initial program 79.7%
sqr-neg79.7%
fabs-div79.7%
sqr-neg79.7%
fabs-sub79.7%
sqr-neg79.7%
distribute-rgt-neg-out79.7%
fabs-neg79.7%
fabs-div79.7%
cancel-sign-sub-inv79.7%
+-commutative79.7%
sqr-neg79.7%
cancel-sign-sub-inv79.7%
Simplified80.3%
fabs-sub80.3%
sub-neg80.3%
metadata-eval80.3%
associate-*r/79.7%
frac-times100.0%
fma-undefine100.0%
add-exp-log100.0%
add-sqr-sqrt100.0%
log-prod100.0%
Applied egg-rr100.0%
*-commutative100.0%
log1p-undefine100.0%
exp-to-pow100.0%
unpow1/2100.0%
sub-neg100.0%
Simplified100.0%
unpow2100.0%
clear-num100.0%
un-div-inv100.0%
Applied egg-rr100.0%
(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 79.7%
sqr-neg79.7%
fabs-div79.7%
sqr-neg79.7%
fabs-sub79.7%
sqr-neg79.7%
distribute-rgt-neg-out79.7%
fabs-neg79.7%
fabs-div79.7%
cancel-sign-sub-inv79.7%
+-commutative79.7%
sqr-neg79.7%
cancel-sign-sub-inv79.7%
Simplified80.3%
fabs-sub80.3%
sub-neg80.3%
metadata-eval80.3%
associate-*r/79.7%
frac-times100.0%
fma-undefine100.0%
add-exp-log100.0%
add-sqr-sqrt100.0%
log-prod100.0%
Applied egg-rr100.0%
*-commutative100.0%
log1p-undefine100.0%
exp-to-pow100.0%
unpow1/2100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in b around 0 99.2%
herbie shell --seed 2024101
(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)))))