
(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 7 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}
Initial program 99.9%
+-commutative99.9%
fma-def99.9%
Simplified99.9%
Final simplification99.9%
(FPCore (x y z) :precision binary64 (if (<= (* x 0.5) -1e-234) (- (* x 0.5) (* y z)) (if (<= (* x 0.5) 2e-236) (* y (+ 1.0 (log z))) (fma y (- z) (* x 0.5)))))
double code(double x, double y, double z) {
double tmp;
if ((x * 0.5) <= -1e-234) {
tmp = (x * 0.5) - (y * z);
} else if ((x * 0.5) <= 2e-236) {
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 (Float64(x * 0.5) <= -1e-234) tmp = Float64(Float64(x * 0.5) - Float64(y * z)); elseif (Float64(x * 0.5) <= 2e-236) 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[N[(x * 0.5), $MachinePrecision], -1e-234], N[(N[(x * 0.5), $MachinePrecision] - N[(y * z), $MachinePrecision]), $MachinePrecision], If[LessEqual[N[(x * 0.5), $MachinePrecision], 2e-236], 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}\;x \cdot 0.5 \leq -1 \cdot 10^{-234}:\\
\;\;\;\;x \cdot 0.5 - y \cdot z\\
\mathbf{elif}\;x \cdot 0.5 \leq 2 \cdot 10^{-236}:\\
\;\;\;\;y \cdot \left(1 + \log z\right)\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(y, -z, x \cdot 0.5\right)\\
\end{array}
\end{array}
if (*.f64 x 1/2) < -9.9999999999999996e-235Initial program 99.8%
distribute-rgt-in99.8%
+-commutative99.8%
add-cube-cbrt99.6%
associate-*l*99.6%
fma-def99.6%
pow299.6%
*-commutative99.6%
Applied egg-rr99.6%
Taylor expanded in z around inf 75.6%
associate-*r*75.6%
neg-mul-175.6%
Simplified75.6%
distribute-lft-neg-out75.6%
unsub-neg75.6%
Applied egg-rr75.6%
if -9.9999999999999996e-235 < (*.f64 x 1/2) < 2.0000000000000001e-236Initial program 99.9%
Taylor expanded in z around 0 65.9%
Taylor expanded in x around 0 65.9%
if 2.0000000000000001e-236 < (*.f64 x 1/2) Initial program 99.9%
+-commutative99.9%
fma-def100.0%
Simplified100.0%
Taylor expanded in z around inf 82.5%
mul-1-neg82.5%
Simplified82.5%
Final simplification77.0%
(FPCore (x y z) :precision binary64 (if (or (<= (* x 0.5) -1e-234) (not (<= (* x 0.5) 2e-236))) (- (* x 0.5) (* y z)) (* y (+ 1.0 (log z)))))
double code(double x, double y, double z) {
double tmp;
if (((x * 0.5) <= -1e-234) || !((x * 0.5) <= 2e-236)) {
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 (((x * 0.5d0) <= (-1d-234)) .or. (.not. ((x * 0.5d0) <= 2d-236))) 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 (((x * 0.5) <= -1e-234) || !((x * 0.5) <= 2e-236)) {
tmp = (x * 0.5) - (y * z);
} else {
tmp = y * (1.0 + Math.log(z));
}
return tmp;
}
def code(x, y, z): tmp = 0 if ((x * 0.5) <= -1e-234) or not ((x * 0.5) <= 2e-236): 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 ((Float64(x * 0.5) <= -1e-234) || !(Float64(x * 0.5) <= 2e-236)) 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 (((x * 0.5) <= -1e-234) || ~(((x * 0.5) <= 2e-236))) 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[N[(x * 0.5), $MachinePrecision], -1e-234], N[Not[LessEqual[N[(x * 0.5), $MachinePrecision], 2e-236]], $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}\;x \cdot 0.5 \leq -1 \cdot 10^{-234} \lor \neg \left(x \cdot 0.5 \leq 2 \cdot 10^{-236}\right):\\
\;\;\;\;x \cdot 0.5 - y \cdot z\\
\mathbf{else}:\\
\;\;\;\;y \cdot \left(1 + \log z\right)\\
\end{array}
\end{array}
if (*.f64 x 1/2) < -9.9999999999999996e-235 or 2.0000000000000001e-236 < (*.f64 x 1/2) Initial program 99.9%
distribute-rgt-in99.9%
+-commutative99.9%
add-cube-cbrt99.6%
associate-*l*99.6%
fma-def99.6%
pow299.6%
*-commutative99.6%
Applied egg-rr99.6%
Taylor expanded in z around inf 78.5%
associate-*r*78.5%
neg-mul-178.5%
Simplified78.5%
distribute-lft-neg-out78.5%
unsub-neg78.5%
Applied egg-rr78.5%
if -9.9999999999999996e-235 < (*.f64 x 1/2) < 2.0000000000000001e-236Initial program 99.9%
Taylor expanded in z around 0 65.9%
Taylor expanded in x around 0 65.9%
Final simplification77.0%
(FPCore (x y z) :precision binary64 (if (<= z 0.0068) (+ (* 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 <= 0.0068) {
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 <= 0.0068) 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, 0.0068], 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 0.0068:\\
\;\;\;\;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}
if z < 0.00679999999999999962Initial program 99.8%
Taylor expanded in z around 0 99.6%
if 0.00679999999999999962 < z Initial program 100.0%
+-commutative100.0%
fma-def100.0%
Simplified100.0%
Taylor expanded in z around inf 97.8%
mul-1-neg97.8%
Simplified97.8%
Final simplification98.7%
(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}
Initial program 99.9%
Final simplification99.9%
(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}
Initial program 99.9%
distribute-rgt-in99.4%
+-commutative99.4%
add-cube-cbrt99.1%
associate-*l*99.1%
fma-def99.5%
pow299.5%
*-commutative99.5%
Applied egg-rr99.5%
Taylor expanded in z around inf 73.1%
associate-*r*73.1%
neg-mul-173.1%
Simplified73.1%
distribute-lft-neg-out73.1%
unsub-neg73.1%
Applied egg-rr73.1%
Final simplification73.1%
(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}
Initial program 99.9%
Taylor expanded in x around inf 42.6%
Final simplification42.6%
(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 2024021
(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)))))