
(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 6.0%
flip--6.3%
div-inv6.3%
add-sqr-sqrt6.5%
add-sqr-sqrt8.0%
associate--l+8.0%
Applied egg-rr8.0%
associate-*r/8.0%
*-rgt-identity8.0%
+-commutative8.0%
associate-+l-99.6%
div-sub99.6%
+-inverses99.6%
div099.6%
--rgt-identity99.6%
+-commutative99.6%
Simplified99.6%
Final simplification99.6%
(FPCore (x) :precision binary64 (* (pow x -0.5) 0.5))
double code(double x) {
return pow(x, -0.5) * 0.5;
}
real(8) function code(x)
real(8), intent (in) :: x
code = (x ** (-0.5d0)) * 0.5d0
end function
public static double code(double x) {
return Math.pow(x, -0.5) * 0.5;
}
def code(x): return math.pow(x, -0.5) * 0.5
function code(x) return Float64((x ^ -0.5) * 0.5) end
function tmp = code(x) tmp = (x ^ -0.5) * 0.5; end
code[x_] := N[(N[Power[x, -0.5], $MachinePrecision] * 0.5), $MachinePrecision]
\begin{array}{l}
\\
{x}^{-0.5} \cdot 0.5
\end{array}
Initial program 6.0%
flip--6.3%
div-inv6.3%
add-sqr-sqrt6.5%
add-sqr-sqrt8.0%
associate--l+8.0%
Applied egg-rr8.0%
associate-*r/8.0%
*-rgt-identity8.0%
+-commutative8.0%
associate-+l-99.6%
div-sub99.6%
+-inverses99.6%
div099.6%
--rgt-identity99.6%
+-commutative99.6%
Simplified99.6%
Taylor expanded in x around inf 98.5%
*-commutative98.5%
unpow1/298.5%
rem-exp-log91.3%
exp-neg91.3%
exp-prod91.3%
distribute-lft-neg-out91.3%
distribute-rgt-neg-in91.3%
metadata-eval91.3%
exp-to-pow98.7%
Simplified98.7%
Final simplification98.7%
(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 6.0%
flip--6.3%
div-inv6.3%
add-sqr-sqrt6.5%
add-sqr-sqrt8.0%
associate--l+8.0%
Applied egg-rr8.0%
associate-*r/8.0%
*-rgt-identity8.0%
+-commutative8.0%
associate-+l-99.6%
div-sub99.6%
+-inverses99.6%
div099.6%
--rgt-identity99.6%
+-commutative99.6%
Simplified99.6%
Taylor expanded in x around inf 98.3%
add-sqr-sqrt97.8%
sqrt-unprod98.3%
associate-/r*98.3%
metadata-eval98.3%
associate-/r*98.3%
metadata-eval98.3%
frac-times98.2%
metadata-eval98.2%
add-sqr-sqrt98.5%
Applied egg-rr98.5%
Final simplification98.5%
(FPCore (x) :precision binary64 0.5)
double code(double x) {
return 0.5;
}
real(8) function code(x)
real(8), intent (in) :: x
code = 0.5d0
end function
public static double code(double x) {
return 0.5;
}
def code(x): return 0.5
function code(x) return 0.5 end
function tmp = code(x) tmp = 0.5; end
code[x_] := 0.5
\begin{array}{l}
\\
0.5
\end{array}
Initial program 6.0%
flip--6.3%
div-inv6.3%
add-sqr-sqrt6.5%
add-sqr-sqrt8.0%
associate--l+8.0%
Applied egg-rr8.0%
associate-*r/8.0%
*-rgt-identity8.0%
+-commutative8.0%
associate-+l-99.6%
div-sub99.6%
+-inverses99.6%
div099.6%
--rgt-identity99.6%
+-commutative99.6%
Simplified99.6%
Taylor expanded in x around inf 98.3%
add-sqr-sqrt97.8%
sqrt-unprod98.3%
associate-/r*98.3%
metadata-eval98.3%
associate-/r*98.3%
metadata-eval98.3%
frac-times98.2%
metadata-eval98.2%
add-sqr-sqrt98.5%
Applied egg-rr98.5%
Applied egg-rr6.9%
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 2024080
(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)))