
(FPCore (x y z) :precision binary64 (+ (* x 0.5) (* y (+ (- 1.0 z) (log z)))))
double code(double x, double y, double z) {
return (x * 0.5) + (y * ((1.0 - z) + log(z)));
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = (x * 0.5d0) + (y * ((1.0d0 - z) + log(z)))
end function
public static double code(double x, double y, double z) {
return (x * 0.5) + (y * ((1.0 - z) + Math.log(z)));
}
def code(x, y, z): return (x * 0.5) + (y * ((1.0 - z) + math.log(z)))
function code(x, y, z) return Float64(Float64(x * 0.5) + Float64(y * Float64(Float64(1.0 - z) + log(z)))) end
function tmp = code(x, y, z) tmp = (x * 0.5) + (y * ((1.0 - z) + log(z))); end
code[x_, y_, z_] := N[(N[(x * 0.5), $MachinePrecision] + N[(y * N[(N[(1.0 - z), $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right)
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y z) :precision binary64 (+ (* x 0.5) (* y (+ (- 1.0 z) (log z)))))
double code(double x, double y, double z) {
return (x * 0.5) + (y * ((1.0 - z) + log(z)));
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = (x * 0.5d0) + (y * ((1.0d0 - z) + log(z)))
end function
public static double code(double x, double y, double z) {
return (x * 0.5) + (y * ((1.0 - z) + Math.log(z)));
}
def code(x, y, z): return (x * 0.5) + (y * ((1.0 - z) + math.log(z)))
function code(x, y, z) return Float64(Float64(x * 0.5) + Float64(y * Float64(Float64(1.0 - z) + log(z)))) end
function tmp = code(x, y, z) tmp = (x * 0.5) + (y * ((1.0 - z) + log(z))); end
code[x_, y_, z_] := N[(N[(x * 0.5), $MachinePrecision] + N[(y * N[(N[(1.0 - z), $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right)
\end{array}
(FPCore (x y z) :precision binary64 (fma y (+ (- 1.0 z) (log z)) (* x 0.5)))
double code(double x, double y, double z) {
return fma(y, ((1.0 - z) + log(z)), (x * 0.5));
}
function code(x, y, z) return fma(y, Float64(Float64(1.0 - z) + log(z)), Float64(x * 0.5)) end
code[x_, y_, z_] := N[(y * N[(N[(1.0 - z), $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision] + N[(x * 0.5), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(y, \left(1 - z\right) + \log z, x \cdot 0.5\right)
\end{array}
(FPCore (x y z) :precision binary64 (if (<= z 0.28) (+ (* x 0.5) (* y (+ 1.0 (log z)))) (fma y (- z) (* x 0.5))))
double code(double x, double y, double z) {
double tmp;
if (z <= 0.28) {
tmp = (x * 0.5) + (y * (1.0 + log(z)));
} else {
tmp = fma(y, -z, (x * 0.5));
}
return tmp;
}
function code(x, y, z) tmp = 0.0 if (z <= 0.28) tmp = Float64(Float64(x * 0.5) + Float64(y * Float64(1.0 + log(z)))); else tmp = fma(y, Float64(-z), Float64(x * 0.5)); end return tmp end
code[x_, y_, z_] := If[LessEqual[z, 0.28], N[(N[(x * 0.5), $MachinePrecision] + N[(y * N[(1.0 + N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(y * (-z) + N[(x * 0.5), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq 0.28:\\
\;\;\;\;x \cdot 0.5 + y \cdot \left(1 + \log z\right)\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(y, -z, x \cdot 0.5\right)\\
\end{array}
\end{array}
(FPCore (x y z) :precision binary64 (+ (* x 0.5) (* y (+ (- 1.0 z) (log z)))))
double code(double x, double y, double z) {
return (x * 0.5) + (y * ((1.0 - z) + log(z)));
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = (x * 0.5d0) + (y * ((1.0d0 - z) + log(z)))
end function
public static double code(double x, double y, double z) {
return (x * 0.5) + (y * ((1.0 - z) + Math.log(z)));
}
def code(x, y, z): return (x * 0.5) + (y * ((1.0 - z) + math.log(z)))
function code(x, y, z) return Float64(Float64(x * 0.5) + Float64(y * Float64(Float64(1.0 - z) + log(z)))) end
function tmp = code(x, y, z) tmp = (x * 0.5) + (y * ((1.0 - z) + log(z))); end
code[x_, y_, z_] := N[(N[(x * 0.5), $MachinePrecision] + N[(y * N[(N[(1.0 - z), $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right)
\end{array}
(FPCore (x y z) :precision binary64 (if (<= y -2.85e+144) (- (* x 0.5) (* y z)) (if (<= y -1.8e+114) (+ y (* y (log z))) (fma y (- z) (* x 0.5)))))
double code(double x, double y, double z) {
double tmp;
if (y <= -2.85e+144) {
tmp = (x * 0.5) - (y * z);
} else if (y <= -1.8e+114) {
tmp = y + (y * log(z));
} else {
tmp = fma(y, -z, (x * 0.5));
}
return tmp;
}
function code(x, y, z) tmp = 0.0 if (y <= -2.85e+144) tmp = Float64(Float64(x * 0.5) - Float64(y * z)); elseif (y <= -1.8e+114) tmp = Float64(y + Float64(y * log(z))); else tmp = fma(y, Float64(-z), Float64(x * 0.5)); end return tmp end
code[x_, y_, z_] := If[LessEqual[y, -2.85e+144], N[(N[(x * 0.5), $MachinePrecision] - N[(y * z), $MachinePrecision]), $MachinePrecision], If[LessEqual[y, -1.8e+114], N[(y + N[(y * N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(y * (-z) + N[(x * 0.5), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -2.85 \cdot 10^{+144}:\\
\;\;\;\;x \cdot 0.5 - y \cdot z\\
\mathbf{elif}\;y \leq -1.8 \cdot 10^{+114}:\\
\;\;\;\;y + y \cdot \log z\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(y, -z, x \cdot 0.5\right)\\
\end{array}
\end{array}
(FPCore (x y z) :precision binary64 (if (or (<= y -2.85e+144) (not (<= y -1.8e+114))) (- (* x 0.5) (* y z)) (* y (+ 1.0 (log z)))))
double code(double x, double y, double z) {
double tmp;
if ((y <= -2.85e+144) || !(y <= -1.8e+114)) {
tmp = (x * 0.5) - (y * z);
} else {
tmp = y * (1.0 + log(z));
}
return tmp;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8) :: tmp
if ((y <= (-2.85d+144)) .or. (.not. (y <= (-1.8d+114)))) then
tmp = (x * 0.5d0) - (y * z)
else
tmp = y * (1.0d0 + log(z))
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double tmp;
if ((y <= -2.85e+144) || !(y <= -1.8e+114)) {
tmp = (x * 0.5) - (y * z);
} else {
tmp = y * (1.0 + Math.log(z));
}
return tmp;
}
def code(x, y, z): tmp = 0 if (y <= -2.85e+144) or not (y <= -1.8e+114): tmp = (x * 0.5) - (y * z) else: tmp = y * (1.0 + math.log(z)) return tmp
function code(x, y, z) tmp = 0.0 if ((y <= -2.85e+144) || !(y <= -1.8e+114)) tmp = Float64(Float64(x * 0.5) - Float64(y * z)); else tmp = Float64(y * Float64(1.0 + log(z))); end return tmp end
function tmp_2 = code(x, y, z) tmp = 0.0; if ((y <= -2.85e+144) || ~((y <= -1.8e+114))) tmp = (x * 0.5) - (y * z); else tmp = y * (1.0 + log(z)); end tmp_2 = tmp; end
code[x_, y_, z_] := If[Or[LessEqual[y, -2.85e+144], N[Not[LessEqual[y, -1.8e+114]], $MachinePrecision]], N[(N[(x * 0.5), $MachinePrecision] - N[(y * z), $MachinePrecision]), $MachinePrecision], N[(y * N[(1.0 + N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -2.85 \cdot 10^{+144} \lor \neg \left(y \leq -1.8 \cdot 10^{+114}\right):\\
\;\;\;\;x \cdot 0.5 - y \cdot z\\
\mathbf{else}:\\
\;\;\;\;y \cdot \left(1 + \log z\right)\\
\end{array}
\end{array}
(FPCore (x y z) :precision binary64 (if (or (<= y -8.2e+144) (not (<= y -1.8e+114))) (- (* x 0.5) (* y z)) (+ y (* y (log z)))))
double code(double x, double y, double z) {
double tmp;
if ((y <= -8.2e+144) || !(y <= -1.8e+114)) {
tmp = (x * 0.5) - (y * z);
} else {
tmp = y + (y * log(z));
}
return tmp;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8) :: tmp
if ((y <= (-8.2d+144)) .or. (.not. (y <= (-1.8d+114)))) then
tmp = (x * 0.5d0) - (y * z)
else
tmp = y + (y * log(z))
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double tmp;
if ((y <= -8.2e+144) || !(y <= -1.8e+114)) {
tmp = (x * 0.5) - (y * z);
} else {
tmp = y + (y * Math.log(z));
}
return tmp;
}
def code(x, y, z): tmp = 0 if (y <= -8.2e+144) or not (y <= -1.8e+114): tmp = (x * 0.5) - (y * z) else: tmp = y + (y * math.log(z)) return tmp
function code(x, y, z) tmp = 0.0 if ((y <= -8.2e+144) || !(y <= -1.8e+114)) tmp = Float64(Float64(x * 0.5) - Float64(y * z)); else tmp = Float64(y + Float64(y * log(z))); end return tmp end
function tmp_2 = code(x, y, z) tmp = 0.0; if ((y <= -8.2e+144) || ~((y <= -1.8e+114))) tmp = (x * 0.5) - (y * z); else tmp = y + (y * log(z)); end tmp_2 = tmp; end
code[x_, y_, z_] := If[Or[LessEqual[y, -8.2e+144], N[Not[LessEqual[y, -1.8e+114]], $MachinePrecision]], N[(N[(x * 0.5), $MachinePrecision] - N[(y * z), $MachinePrecision]), $MachinePrecision], N[(y + N[(y * N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -8.2 \cdot 10^{+144} \lor \neg \left(y \leq -1.8 \cdot 10^{+114}\right):\\
\;\;\;\;x \cdot 0.5 - y \cdot z\\
\mathbf{else}:\\
\;\;\;\;y + y \cdot \log z\\
\end{array}
\end{array}
(FPCore (x y z) :precision binary64 (- (* x 0.5) (* y z)))
double code(double x, double y, double z) {
return (x * 0.5) - (y * z);
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = (x * 0.5d0) - (y * z)
end function
public static double code(double x, double y, double z) {
return (x * 0.5) - (y * z);
}
def code(x, y, z): return (x * 0.5) - (y * z)
function code(x, y, z) return Float64(Float64(x * 0.5) - Float64(y * z)) end
function tmp = code(x, y, z) tmp = (x * 0.5) - (y * z); end
code[x_, y_, z_] := N[(N[(x * 0.5), $MachinePrecision] - N[(y * z), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot 0.5 - y \cdot z
\end{array}
(FPCore (x y z) :precision binary64 (* x 0.5))
double code(double x, double y, double z) {
return x * 0.5;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = x * 0.5d0
end function
public static double code(double x, double y, double z) {
return x * 0.5;
}
def code(x, y, z): return x * 0.5
function code(x, y, z) return Float64(x * 0.5) end
function tmp = code(x, y, z) tmp = x * 0.5; end
code[x_, y_, z_] := N[(x * 0.5), $MachinePrecision]
\begin{array}{l}
\\
x \cdot 0.5
\end{array}
(FPCore (x y z) :precision binary64 (- (+ y (* 0.5 x)) (* y (- z (log z)))))
double code(double x, double y, double z) {
return (y + (0.5 * x)) - (y * (z - log(z)));
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = (y + (0.5d0 * x)) - (y * (z - log(z)))
end function
public static double code(double x, double y, double z) {
return (y + (0.5 * x)) - (y * (z - Math.log(z)));
}
def code(x, y, z): return (y + (0.5 * x)) - (y * (z - math.log(z)))
function code(x, y, z) return Float64(Float64(y + Float64(0.5 * x)) - Float64(y * Float64(z - log(z)))) end
function tmp = code(x, y, z) tmp = (y + (0.5 * x)) - (y * (z - log(z))); end
code[x_, y_, z_] := N[(N[(y + N[(0.5 * x), $MachinePrecision]), $MachinePrecision] - N[(y * N[(z - N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(y + 0.5 \cdot x\right) - y \cdot \left(z - \log z\right)
\end{array}
herbie shell --seed 2023343
(FPCore (x y z)
:name "System.Random.MWC.Distributions:gamma from mwc-random-0.13.3.2"
:precision binary64
:herbie-target
(- (+ y (* 0.5 x)) (* y (- z (log z))))
(+ (* x 0.5) (* y (+ (- 1.0 z) (log z)))))