
(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 4 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 (+ 1.0 x)) (sqrt x))))
double code(double x) {
return 1.0 / (sqrt((1.0 + x)) + sqrt(x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = 1.0d0 / (sqrt((1.0d0 + x)) + sqrt(x))
end function
public static double code(double x) {
return 1.0 / (Math.sqrt((1.0 + x)) + Math.sqrt(x));
}
def code(x): return 1.0 / (math.sqrt((1.0 + x)) + math.sqrt(x))
function code(x) return Float64(1.0 / Float64(sqrt(Float64(1.0 + x)) + sqrt(x))) end
function tmp = code(x) tmp = 1.0 / (sqrt((1.0 + x)) + sqrt(x)); end
code[x_] := N[(1.0 / N[(N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision] + N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\sqrt{1 + x} + \sqrt{x}}
\end{array}
Initial program 7.1%
flip--7.8%
div-inv7.8%
add-sqr-sqrt8.2%
add-sqr-sqrt9.8%
associate--l+9.8%
Applied egg-rr9.8%
associate-*r/9.8%
*-rgt-identity9.8%
associate-+r-9.8%
remove-double-neg9.8%
sub-neg9.8%
div-sub7.2%
rem-square-sqrt7.0%
sqr-neg7.0%
div-sub8.2%
+-commutative8.2%
sqr-neg8.2%
rem-square-sqrt9.8%
associate--l+99.6%
+-inverses99.6%
metadata-eval99.6%
sub-neg99.6%
Simplified99.6%
Final simplification99.6%
(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--7.8%
div-inv7.8%
add-sqr-sqrt8.2%
add-sqr-sqrt9.8%
associate--l+9.8%
Applied egg-rr9.8%
associate-*r/9.8%
*-rgt-identity9.8%
associate-+r-9.8%
remove-double-neg9.8%
sub-neg9.8%
div-sub7.2%
rem-square-sqrt7.0%
sqr-neg7.0%
div-sub8.2%
+-commutative8.2%
sqr-neg8.2%
rem-square-sqrt9.8%
associate--l+99.6%
+-inverses99.6%
metadata-eval99.6%
sub-neg99.6%
Simplified99.6%
flip3-+67.1%
associate-/r/67.0%
sqrt-pow266.9%
metadata-eval66.9%
sqrt-pow266.8%
metadata-eval66.8%
add-sqr-sqrt67.1%
add-sqr-sqrt66.8%
associate-+r-66.8%
sqrt-unprod47.5%
Applied egg-rr47.5%
associate-*l/47.6%
*-lft-identity47.6%
associate-+l+47.6%
associate--l+47.6%
count-247.6%
*-commutative47.6%
Simplified47.6%
Taylor expanded in x around inf 65.1%
Taylor expanded in x around inf 97.8%
unpow-197.8%
sqr-pow98.0%
metadata-eval98.0%
metadata-eval98.0%
rem-sqrt-square98.0%
rem-square-sqrt97.2%
fabs-sqr97.2%
rem-square-sqrt98.0%
Simplified98.0%
Final simplification98.0%
(FPCore (x) :precision binary64 0.0)
double code(double x) {
return 0.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = 0.0d0
end function
public static double code(double x) {
return 0.0;
}
def code(x): return 0.0
function code(x) return 0.0 end
function tmp = code(x) tmp = 0.0; end
code[x_] := 0.0
\begin{array}{l}
\\
0
\end{array}
Initial program 7.1%
Taylor expanded in x around inf 3.8%
Final simplification3.8%
(FPCore (x) :precision binary64 1.0)
double code(double x) {
return 1.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = 1.0d0
end function
public static double code(double x) {
return 1.0;
}
def code(x): return 1.0
function code(x) return 1.0 end
function tmp = code(x) tmp = 1.0; end
code[x_] := 1.0
\begin{array}{l}
\\
1
\end{array}
Initial program 7.1%
Taylor expanded in x around 0 6.9%
Final simplification6.9%
(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 2024048
(FPCore (x)
:name "2sqrt (example 3.1)"
:precision binary64
:pre (and (> x 1.0) (< x 1e+308))
:alt
(/ 1.0 (+ (sqrt (+ x 1.0)) (sqrt x)))
(- (sqrt (+ x 1.0)) (sqrt x)))