
(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 9 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 (or (<= y -2.7e+91) (not (<= y 2.8e+97))) (* y (- (+ 1.0 (log z)) z)) (- (* x 0.5) (* y z))))
double code(double x, double y, double z) {
double tmp;
if ((y <= -2.7e+91) || !(y <= 2.8e+97)) {
tmp = y * ((1.0 + log(z)) - z);
} else {
tmp = (x * 0.5) - (y * 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 <= (-2.7d+91)) .or. (.not. (y <= 2.8d+97))) then
tmp = y * ((1.0d0 + log(z)) - z)
else
tmp = (x * 0.5d0) - (y * z)
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double tmp;
if ((y <= -2.7e+91) || !(y <= 2.8e+97)) {
tmp = y * ((1.0 + Math.log(z)) - z);
} else {
tmp = (x * 0.5) - (y * z);
}
return tmp;
}
def code(x, y, z): tmp = 0 if (y <= -2.7e+91) or not (y <= 2.8e+97): tmp = y * ((1.0 + math.log(z)) - z) else: tmp = (x * 0.5) - (y * z) return tmp
function code(x, y, z) tmp = 0.0 if ((y <= -2.7e+91) || !(y <= 2.8e+97)) tmp = Float64(y * Float64(Float64(1.0 + log(z)) - z)); else tmp = Float64(Float64(x * 0.5) - Float64(y * z)); end return tmp end
function tmp_2 = code(x, y, z) tmp = 0.0; if ((y <= -2.7e+91) || ~((y <= 2.8e+97))) tmp = y * ((1.0 + log(z)) - z); else tmp = (x * 0.5) - (y * z); end tmp_2 = tmp; end
code[x_, y_, z_] := If[Or[LessEqual[y, -2.7e+91], N[Not[LessEqual[y, 2.8e+97]], $MachinePrecision]], N[(y * N[(N[(1.0 + N[Log[z], $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]), $MachinePrecision], N[(N[(x * 0.5), $MachinePrecision] - N[(y * z), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -2.7 \cdot 10^{+91} \lor \neg \left(y \leq 2.8 \cdot 10^{+97}\right):\\
\;\;\;\;y \cdot \left(\left(1 + \log z\right) - z\right)\\
\mathbf{else}:\\
\;\;\;\;x \cdot 0.5 - y \cdot z\\
\end{array}
\end{array}
(FPCore (x y z) :precision binary64 (if (<= z 2.1e-5) (+ (* 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 <= 2.1e-5) {
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 <= 2.1e-5) 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, 2.1e-5], 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 2.1 \cdot 10^{-5}:\\
\;\;\;\;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 -9e+264) (* y (+ 1.0 (log z))) (fma y (- z) (* x 0.5))))
double code(double x, double y, double z) {
double tmp;
if (y <= -9e+264) {
tmp = y * (1.0 + log(z));
} else {
tmp = fma(y, -z, (x * 0.5));
}
return tmp;
}
function code(x, y, z) tmp = 0.0 if (y <= -9e+264) tmp = 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[y, -9e+264], N[(y * N[(1.0 + 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 -9 \cdot 10^{+264}:\\
\;\;\;\;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 (if (<= y -2e+264) (* y (+ 1.0 (log z))) (- (* x 0.5) (* y z))))
double code(double x, double y, double z) {
double tmp;
if (y <= -2e+264) {
tmp = y * (1.0 + log(z));
} else {
tmp = (x * 0.5) - (y * 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 <= (-2d+264)) then
tmp = y * (1.0d0 + log(z))
else
tmp = (x * 0.5d0) - (y * z)
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double tmp;
if (y <= -2e+264) {
tmp = y * (1.0 + Math.log(z));
} else {
tmp = (x * 0.5) - (y * z);
}
return tmp;
}
def code(x, y, z): tmp = 0 if y <= -2e+264: tmp = y * (1.0 + math.log(z)) else: tmp = (x * 0.5) - (y * z) return tmp
function code(x, y, z) tmp = 0.0 if (y <= -2e+264) tmp = Float64(y * Float64(1.0 + log(z))); else tmp = Float64(Float64(x * 0.5) - Float64(y * z)); end return tmp end
function tmp_2 = code(x, y, z) tmp = 0.0; if (y <= -2e+264) tmp = y * (1.0 + log(z)); else tmp = (x * 0.5) - (y * z); end tmp_2 = tmp; end
code[x_, y_, z_] := If[LessEqual[y, -2e+264], N[(y * N[(1.0 + N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(x * 0.5), $MachinePrecision] - N[(y * z), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -2 \cdot 10^{+264}:\\
\;\;\;\;y \cdot \left(1 + \log z\right)\\
\mathbf{else}:\\
\;\;\;\;x \cdot 0.5 - y \cdot z\\
\end{array}
\end{array}
(FPCore (x y z)
:precision binary64
(if (or (<= z 4.3e+27)
(and (not (<= z 3.45e+87))
(or (<= z 3.8e+103)
(and (not (<= z 5.8e+137)) (<= z 1.52e+171)))))
(* x 0.5)
(* z (- y))))
double code(double x, double y, double z) {
double tmp;
if ((z <= 4.3e+27) || (!(z <= 3.45e+87) && ((z <= 3.8e+103) || (!(z <= 5.8e+137) && (z <= 1.52e+171))))) {
tmp = x * 0.5;
} else {
tmp = z * -y;
}
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 ((z <= 4.3d+27) .or. (.not. (z <= 3.45d+87)) .and. (z <= 3.8d+103) .or. (.not. (z <= 5.8d+137)) .and. (z <= 1.52d+171)) then
tmp = x * 0.5d0
else
tmp = z * -y
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double tmp;
if ((z <= 4.3e+27) || (!(z <= 3.45e+87) && ((z <= 3.8e+103) || (!(z <= 5.8e+137) && (z <= 1.52e+171))))) {
tmp = x * 0.5;
} else {
tmp = z * -y;
}
return tmp;
}
def code(x, y, z): tmp = 0 if (z <= 4.3e+27) or (not (z <= 3.45e+87) and ((z <= 3.8e+103) or (not (z <= 5.8e+137) and (z <= 1.52e+171)))): tmp = x * 0.5 else: tmp = z * -y return tmp
function code(x, y, z) tmp = 0.0 if ((z <= 4.3e+27) || (!(z <= 3.45e+87) && ((z <= 3.8e+103) || (!(z <= 5.8e+137) && (z <= 1.52e+171))))) tmp = Float64(x * 0.5); else tmp = Float64(z * Float64(-y)); end return tmp end
function tmp_2 = code(x, y, z) tmp = 0.0; if ((z <= 4.3e+27) || (~((z <= 3.45e+87)) && ((z <= 3.8e+103) || (~((z <= 5.8e+137)) && (z <= 1.52e+171))))) tmp = x * 0.5; else tmp = z * -y; end tmp_2 = tmp; end
code[x_, y_, z_] := If[Or[LessEqual[z, 4.3e+27], And[N[Not[LessEqual[z, 3.45e+87]], $MachinePrecision], Or[LessEqual[z, 3.8e+103], And[N[Not[LessEqual[z, 5.8e+137]], $MachinePrecision], LessEqual[z, 1.52e+171]]]]], N[(x * 0.5), $MachinePrecision], N[(z * (-y)), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq 4.3 \cdot 10^{+27} \lor \neg \left(z \leq 3.45 \cdot 10^{+87}\right) \land \left(z \leq 3.8 \cdot 10^{+103} \lor \neg \left(z \leq 5.8 \cdot 10^{+137}\right) \land z \leq 1.52 \cdot 10^{+171}\right):\\
\;\;\;\;x \cdot 0.5\\
\mathbf{else}:\\
\;\;\;\;z \cdot \left(-y\right)\\
\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 2023348
(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)))))