
(FPCore (x y) :precision binary64 (* 0.5 (- (* x x) y)))
double code(double x, double y) {
return 0.5 * ((x * x) - y);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = 0.5d0 * ((x * x) - y)
end function
public static double code(double x, double y) {
return 0.5 * ((x * x) - y);
}
def code(x, y): return 0.5 * ((x * x) - y)
function code(x, y) return Float64(0.5 * Float64(Float64(x * x) - y)) end
function tmp = code(x, y) tmp = 0.5 * ((x * x) - y); end
code[x_, y_] := N[(0.5 * N[(N[(x * x), $MachinePrecision] - y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.5 \cdot \left(x \cdot x - y\right)
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y) :precision binary64 (* 0.5 (- (* x x) y)))
double code(double x, double y) {
return 0.5 * ((x * x) - y);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = 0.5d0 * ((x * x) - y)
end function
public static double code(double x, double y) {
return 0.5 * ((x * x) - y);
}
def code(x, y): return 0.5 * ((x * x) - y)
function code(x, y) return Float64(0.5 * Float64(Float64(x * x) - y)) end
function tmp = code(x, y) tmp = 0.5 * ((x * x) - y); end
code[x_, y_] := N[(0.5 * N[(N[(x * x), $MachinePrecision] - y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.5 \cdot \left(x \cdot x - y\right)
\end{array}
(FPCore (x y) :precision binary64 (fma (* x 0.5) x (* y -0.5)))
double code(double x, double y) {
return fma((x * 0.5), x, (y * -0.5));
}
function code(x, y) return fma(Float64(x * 0.5), x, Float64(y * -0.5)) end
code[x_, y_] := N[(N[(x * 0.5), $MachinePrecision] * x + N[(y * -0.5), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(x \cdot 0.5, x, y \cdot -0.5\right)
\end{array}
Initial program 99.7%
lift-*.f64N/A
lift--.f64N/A
sub-negN/A
distribute-lft-inN/A
lift-*.f64N/A
sqr-neg-revN/A
associate-*r*N/A
neg-mul-1N/A
metadata-evalN/A
unpow1N/A
unpow-prod-downN/A
neg-mul-1N/A
metadata-evalN/A
sqrt-pow1N/A
pow2N/A
sqr-neg-revN/A
sqrt-prodN/A
rem-square-sqrtN/A
*-commutativeN/A
lower-fma.f64N/A
Applied rewrites100.0%
Final simplification100.0%
(FPCore (x y) :precision binary64 (if (<= (* x x) 2e+39) (* y -0.5) (* (* x 0.5) x)))
double code(double x, double y) {
double tmp;
if ((x * x) <= 2e+39) {
tmp = y * -0.5;
} else {
tmp = (x * 0.5) * x;
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if ((x * x) <= 2d+39) then
tmp = y * (-0.5d0)
else
tmp = (x * 0.5d0) * x
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if ((x * x) <= 2e+39) {
tmp = y * -0.5;
} else {
tmp = (x * 0.5) * x;
}
return tmp;
}
def code(x, y): tmp = 0 if (x * x) <= 2e+39: tmp = y * -0.5 else: tmp = (x * 0.5) * x return tmp
function code(x, y) tmp = 0.0 if (Float64(x * x) <= 2e+39) tmp = Float64(y * -0.5); else tmp = Float64(Float64(x * 0.5) * x); end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if ((x * x) <= 2e+39) tmp = y * -0.5; else tmp = (x * 0.5) * x; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[N[(x * x), $MachinePrecision], 2e+39], N[(y * -0.5), $MachinePrecision], N[(N[(x * 0.5), $MachinePrecision] * x), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \cdot x \leq 2 \cdot 10^{+39}:\\
\;\;\;\;y \cdot -0.5\\
\mathbf{else}:\\
\;\;\;\;\left(x \cdot 0.5\right) \cdot x\\
\end{array}
\end{array}
if (*.f64 x x) < 1.99999999999999988e39Initial program 100.0%
Taylor expanded in x around 0
lower-*.f6485.8
Applied rewrites85.8%
if 1.99999999999999988e39 < (*.f64 x x) Initial program 99.3%
Taylor expanded in x around inf
*-commutativeN/A
lower-*.f64N/A
unpow2N/A
lower-*.f6492.2
Applied rewrites92.2%
Applied rewrites92.9%
Final simplification89.0%
(FPCore (x y) :precision binary64 (* (fma x x (- y)) 0.5))
double code(double x, double y) {
return fma(x, x, -y) * 0.5;
}
function code(x, y) return Float64(fma(x, x, Float64(-y)) * 0.5) end
code[x_, y_] := N[(N[(x * x + (-y)), $MachinePrecision] * 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(x, x, -y\right) \cdot 0.5
\end{array}
Initial program 99.7%
lift--.f64N/A
sub-negN/A
lift-*.f64N/A
lower-fma.f64N/A
lower-neg.f6499.7
Applied rewrites99.7%
Final simplification99.7%
(FPCore (x y) :precision binary64 (* (- (* x x) y) 0.5))
double code(double x, double y) {
return ((x * x) - y) * 0.5;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = ((x * x) - y) * 0.5d0
end function
public static double code(double x, double y) {
return ((x * x) - y) * 0.5;
}
def code(x, y): return ((x * x) - y) * 0.5
function code(x, y) return Float64(Float64(Float64(x * x) - y) * 0.5) end
function tmp = code(x, y) tmp = ((x * x) - y) * 0.5; end
code[x_, y_] := N[(N[(N[(x * x), $MachinePrecision] - y), $MachinePrecision] * 0.5), $MachinePrecision]
\begin{array}{l}
\\
\left(x \cdot x - y\right) \cdot 0.5
\end{array}
Initial program 99.7%
Final simplification99.7%
(FPCore (x y) :precision binary64 (* y -0.5))
double code(double x, double y) {
return y * -0.5;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = y * (-0.5d0)
end function
public static double code(double x, double y) {
return y * -0.5;
}
def code(x, y): return y * -0.5
function code(x, y) return Float64(y * -0.5) end
function tmp = code(x, y) tmp = y * -0.5; end
code[x_, y_] := N[(y * -0.5), $MachinePrecision]
\begin{array}{l}
\\
y \cdot -0.5
\end{array}
Initial program 99.7%
Taylor expanded in x around 0
lower-*.f6451.2
Applied rewrites51.2%
Final simplification51.2%
herbie shell --seed 2024298
(FPCore (x y)
:name "System.Random.MWC.Distributions:standard from mwc-random-0.13.3.2"
:precision binary64
(* 0.5 (- (* x x) y)))