
(FPCore (x) :precision binary64 (sqrt (* 2.0 (* x x))))
double code(double x) {
return sqrt((2.0 * (x * x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = sqrt((2.0d0 * (x * x)))
end function
public static double code(double x) {
return Math.sqrt((2.0 * (x * x)));
}
def code(x): return math.sqrt((2.0 * (x * x)))
function code(x) return sqrt(Float64(2.0 * Float64(x * x))) end
function tmp = code(x) tmp = sqrt((2.0 * (x * x))); end
code[x_] := N[Sqrt[N[(2.0 * N[(x * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{2 \cdot \left(x \cdot x\right)}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 4 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (sqrt (* 2.0 (* x x))))
double code(double x) {
return sqrt((2.0 * (x * x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = sqrt((2.0d0 * (x * x)))
end function
public static double code(double x) {
return Math.sqrt((2.0 * (x * x)));
}
def code(x): return math.sqrt((2.0 * (x * x)))
function code(x) return sqrt(Float64(2.0 * Float64(x * x))) end
function tmp = code(x) tmp = sqrt((2.0 * (x * x))); end
code[x_] := N[Sqrt[N[(2.0 * N[(x * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{2 \cdot \left(x \cdot x\right)}
\end{array}
(FPCore (x) :precision binary64 (hypot x x))
double code(double x) {
return hypot(x, x);
}
public static double code(double x) {
return Math.hypot(x, x);
}
def code(x): return math.hypot(x, x)
function code(x) return hypot(x, x) end
function tmp = code(x) tmp = hypot(x, x); end
code[x_] := N[Sqrt[x ^ 2 + x ^ 2], $MachinePrecision]
\begin{array}{l}
\\
\mathsf{hypot}\left(x, x\right)
\end{array}
Initial program 55.7%
Taylor expanded in x around 0 51.5%
rem-square-sqrt50.3%
fabs-sqr50.3%
rem-square-sqrt99.2%
rem-sqrt-square55.5%
swap-sqr55.3%
unpow255.3%
rem-square-sqrt55.7%
*-commutative55.7%
count-255.7%
unpow255.7%
unpow255.7%
hypot-define100.0%
Simplified100.0%
(FPCore (x) :precision binary64 (* x (* x 2.0)))
double code(double x) {
return x * (x * 2.0);
}
real(8) function code(x)
real(8), intent (in) :: x
code = x * (x * 2.0d0)
end function
public static double code(double x) {
return x * (x * 2.0);
}
def code(x): return x * (x * 2.0)
function code(x) return Float64(x * Float64(x * 2.0)) end
function tmp = code(x) tmp = x * (x * 2.0); end
code[x_] := N[(x * N[(x * 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot \left(x \cdot 2\right)
\end{array}
Initial program 55.7%
Taylor expanded in x around 0 51.5%
rem-square-sqrt50.3%
fabs-sqr50.3%
rem-square-sqrt99.2%
rem-sqrt-square55.5%
swap-sqr55.3%
unpow255.3%
rem-square-sqrt55.7%
*-commutative55.7%
count-255.7%
unpow255.7%
unpow255.7%
hypot-define100.0%
Simplified100.0%
hypot-undefine55.7%
flip-+0.0%
+-inverses0.0%
metadata-eval0.0%
+-inverses0.0%
+-inverses0.0%
+-inverses0.0%
metadata-eval0.0%
+-inverses0.0%
+-inverses0.0%
frac-times0.0%
flip-+0.0%
flip-+6.4%
sqrt-unprod6.7%
add-sqr-sqrt6.7%
count-26.7%
associate-*r*6.7%
Applied egg-rr6.7%
Final simplification6.7%
(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 55.7%
sqrt-prod55.5%
sqrt-prod50.3%
add-sqr-sqrt51.5%
Applied egg-rr51.5%
Taylor expanded in x around 0 51.5%
Simplified11.1%
Applied egg-rr3.7%
(FPCore (x) :precision binary64 -2.0)
double code(double x) {
return -2.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = -2.0d0
end function
public static double code(double x) {
return -2.0;
}
def code(x): return -2.0
function code(x) return -2.0 end
function tmp = code(x) tmp = -2.0; end
code[x_] := -2.0
\begin{array}{l}
\\
-2
\end{array}
Initial program 55.7%
sqrt-prod55.5%
sqrt-prod50.3%
add-sqr-sqrt51.5%
Applied egg-rr51.5%
add-sqr-sqrt50.3%
sqrt-unprod55.5%
sqrt-prod55.7%
count-255.7%
flip-+0.0%
+-inverses0.0%
metadata-eval0.0%
+-inverses0.0%
+-inverses0.0%
+-inverses0.0%
metadata-eval0.0%
+-inverses0.0%
+-inverses0.0%
frac-times0.0%
flip-+0.0%
flip-+6.4%
sqrt-unprod6.7%
Applied egg-rr6.7%
Simplified1.7%
herbie shell --seed 2024110
(FPCore (x)
:name "sqrt C (should all be same)"
:precision binary64
(sqrt (* 2.0 (* x x))))