
(FPCore (x) :precision binary64 (- (sqrt (+ x 1.0)) (sqrt x)))
double code(double x) {
return sqrt((x + 1.0)) - sqrt(x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = sqrt((x + 1.0d0)) - sqrt(x)
end function
public static double code(double x) {
return Math.sqrt((x + 1.0)) - Math.sqrt(x);
}
def code(x): return math.sqrt((x + 1.0)) - math.sqrt(x)
function code(x) return Float64(sqrt(Float64(x + 1.0)) - sqrt(x)) end
function tmp = code(x) tmp = sqrt((x + 1.0)) - sqrt(x); end
code[x_] := N[(N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\sqrt{x + 1} - \sqrt{x}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (- (sqrt (+ x 1.0)) (sqrt x)))
double code(double x) {
return sqrt((x + 1.0)) - sqrt(x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = sqrt((x + 1.0d0)) - sqrt(x)
end function
public static double code(double x) {
return Math.sqrt((x + 1.0)) - Math.sqrt(x);
}
def code(x): return math.sqrt((x + 1.0)) - math.sqrt(x)
function code(x) return Float64(sqrt(Float64(x + 1.0)) - sqrt(x)) end
function tmp = code(x) tmp = sqrt((x + 1.0)) - sqrt(x); end
code[x_] := N[(N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\sqrt{x + 1} - \sqrt{x}
\end{array}
(FPCore (x) :precision binary64 (/ 1.0 (+ (sqrt x) (sqrt (+ 1.0 x)))))
double code(double x) {
return 1.0 / (sqrt(x) + sqrt((1.0 + x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = 1.0d0 / (sqrt(x) + sqrt((1.0d0 + x)))
end function
public static double code(double x) {
return 1.0 / (Math.sqrt(x) + Math.sqrt((1.0 + x)));
}
def code(x): return 1.0 / (math.sqrt(x) + math.sqrt((1.0 + x)))
function code(x) return Float64(1.0 / Float64(sqrt(x) + sqrt(Float64(1.0 + x)))) end
function tmp = code(x) tmp = 1.0 / (sqrt(x) + sqrt((1.0 + x))); end
code[x_] := N[(1.0 / N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\sqrt{x} + \sqrt{1 + x}}
\end{array}
Initial program 7.1%
flip--7.9%
div-inv7.9%
add-sqr-sqrt8.2%
add-sqr-sqrt9.0%
associate--l+9.0%
Applied egg-rr9.0%
associate-*r/9.0%
*-rgt-identity9.0%
+-commutative9.0%
associate-+l-99.6%
+-inverses99.6%
metadata-eval99.6%
+-commutative99.6%
+-commutative99.6%
Simplified99.6%
(FPCore (x) :precision binary64 (* 0.5 (pow x -0.5)))
double code(double x) {
return 0.5 * pow(x, -0.5);
}
real(8) function code(x)
real(8), intent (in) :: x
code = 0.5d0 * (x ** (-0.5d0))
end function
public static double code(double x) {
return 0.5 * Math.pow(x, -0.5);
}
def code(x): return 0.5 * math.pow(x, -0.5)
function code(x) return Float64(0.5 * (x ^ -0.5)) end
function tmp = code(x) tmp = 0.5 * (x ^ -0.5); end
code[x_] := N[(0.5 * N[Power[x, -0.5], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.5 \cdot {x}^{-0.5}
\end{array}
Initial program 7.1%
flip--7.9%
div-inv7.9%
add-sqr-sqrt8.2%
add-sqr-sqrt9.0%
associate--l+9.0%
Applied egg-rr9.0%
associate-*r/9.0%
*-rgt-identity9.0%
+-commutative9.0%
associate-+l-99.6%
+-inverses99.6%
metadata-eval99.6%
+-commutative99.6%
+-commutative99.6%
Simplified99.6%
Taylor expanded in x around inf 97.5%
unpow-197.5%
metadata-eval97.5%
pow-sqr97.7%
rem-sqrt-square97.7%
rem-square-sqrt97.0%
fabs-sqr97.0%
rem-square-sqrt97.7%
Simplified97.7%
(FPCore (x) :precision binary64 (sqrt (/ 0.25 x)))
double code(double x) {
return sqrt((0.25 / x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = sqrt((0.25d0 / x))
end function
public static double code(double x) {
return Math.sqrt((0.25 / x));
}
def code(x): return math.sqrt((0.25 / x))
function code(x) return sqrt(Float64(0.25 / x)) end
function tmp = code(x) tmp = sqrt((0.25 / x)); end
code[x_] := N[Sqrt[N[(0.25 / x), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{\frac{0.25}{x}}
\end{array}
Initial program 7.1%
Taylor expanded in x around inf 97.5%
add-sqr-sqrt96.9%
sqrt-unprod97.5%
*-commutative97.5%
*-commutative97.5%
swap-sqr97.5%
add-sqr-sqrt97.5%
metadata-eval97.5%
Applied egg-rr97.5%
associate-*l/97.5%
metadata-eval97.5%
Simplified97.5%
(FPCore (x) :precision binary64 (pow x -0.5))
double code(double x) {
return pow(x, -0.5);
}
real(8) function code(x)
real(8), intent (in) :: x
code = x ** (-0.5d0)
end function
public static double code(double x) {
return Math.pow(x, -0.5);
}
def code(x): return math.pow(x, -0.5)
function code(x) return x ^ -0.5 end
function tmp = code(x) tmp = x ^ -0.5; end
code[x_] := N[Power[x, -0.5], $MachinePrecision]
\begin{array}{l}
\\
{x}^{-0.5}
\end{array}
Initial program 7.1%
Taylor expanded in x around 0 1.6%
Taylor expanded in x around inf 1.6%
neg-mul-11.6%
Simplified1.6%
add-sqr-sqrt0.0%
sqrt-unprod5.5%
sqr-neg5.5%
add-exp-log5.5%
add-sqr-sqrt5.5%
add-sqr-sqrt5.5%
sqrt-unprod5.5%
sqr-neg5.5%
sqrt-unprod0.0%
add-sqr-sqrt18.7%
neg-log18.7%
add-exp-log18.7%
inv-pow18.7%
metadata-eval18.7%
pow-prod-up18.7%
sqrt-unprod18.7%
sqrt-pow118.7%
metadata-eval18.7%
sqrt-pow118.7%
metadata-eval18.7%
Applied egg-rr18.7%
pow-sqr18.7%
metadata-eval18.7%
Simplified18.7%
(FPCore (x) :precision binary64 (sqrt x))
double code(double x) {
return sqrt(x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = sqrt(x)
end function
public static double code(double x) {
return Math.sqrt(x);
}
def code(x): return math.sqrt(x)
function code(x) return sqrt(x) end
function tmp = code(x) tmp = sqrt(x); end
code[x_] := N[Sqrt[x], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{x}
\end{array}
Initial program 7.1%
Taylor expanded in x around 0 1.6%
Taylor expanded in x around inf 1.6%
neg-mul-11.6%
Simplified1.6%
neg-sub01.6%
sub-neg1.6%
add-sqr-sqrt0.0%
sqrt-unprod5.5%
sqr-neg5.5%
add-sqr-sqrt5.5%
pow1/25.5%
add-exp-log5.5%
add-sqr-sqrt5.5%
sqrt-unprod5.5%
sqr-neg5.5%
sqrt-unprod0.0%
add-sqr-sqrt18.7%
exp-prod18.7%
distribute-lft-neg-out18.7%
exp-neg18.7%
pow-to-exp18.7%
pow-flip18.7%
metadata-eval18.7%
add-sqr-sqrt18.7%
sqrt-unprod18.7%
Applied egg-rr5.5%
+-lft-identity5.5%
Simplified5.5%
(FPCore (x) :precision binary64 (/ 1.0 (+ (sqrt (+ x 1.0)) (sqrt x))))
double code(double x) {
return 1.0 / (sqrt((x + 1.0)) + sqrt(x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = 1.0d0 / (sqrt((x + 1.0d0)) + sqrt(x))
end function
public static double code(double x) {
return 1.0 / (Math.sqrt((x + 1.0)) + Math.sqrt(x));
}
def code(x): return 1.0 / (math.sqrt((x + 1.0)) + math.sqrt(x))
function code(x) return Float64(1.0 / Float64(sqrt(Float64(x + 1.0)) + sqrt(x))) end
function tmp = code(x) tmp = 1.0 / (sqrt((x + 1.0)) + sqrt(x)); end
code[x_] := N[(1.0 / N[(N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision] + N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\sqrt{x + 1} + \sqrt{x}}
\end{array}
herbie shell --seed 2024146
(FPCore (x)
:name "2sqrt (example 3.1)"
:precision binary64
:pre (and (> x 1.0) (< x 1e+308))
:alt
(! :herbie-platform default (/ 1 (+ (sqrt (+ x 1)) (sqrt x))))
(- (sqrt (+ x 1.0)) (sqrt x)))