
(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}
Initial program 99.9%
+-commutative99.9%
fma-define99.9%
Simplified99.9%
(FPCore (x y z) :precision binary64 (if (<= z 3.4e-236) (- (* x 0.5) (* y z)) (if (<= z 3.8e-213) (* y (+ 1.0 (log z))) (fma y (- z) (* x 0.5)))))
double code(double x, double y, double z) {
double tmp;
if (z <= 3.4e-236) {
tmp = (x * 0.5) - (y * z);
} else if (z <= 3.8e-213) {
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 (z <= 3.4e-236) tmp = Float64(Float64(x * 0.5) - Float64(y * z)); elseif (z <= 3.8e-213) 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[z, 3.4e-236], N[(N[(x * 0.5), $MachinePrecision] - N[(y * z), $MachinePrecision]), $MachinePrecision], If[LessEqual[z, 3.8e-213], 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}\;z \leq 3.4 \cdot 10^{-236}:\\
\;\;\;\;x \cdot 0.5 - y \cdot z\\
\mathbf{elif}\;z \leq 3.8 \cdot 10^{-213}:\\
\;\;\;\;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 < 3.3999999999999998e-236Initial program 99.9%
Taylor expanded in z around inf 59.7%
associate-*r*59.7%
mul-1-neg59.7%
Simplified59.7%
distribute-lft-neg-out59.7%
unsub-neg59.7%
Applied egg-rr59.7%
if 3.3999999999999998e-236 < z < 3.8e-213Initial program 99.7%
Taylor expanded in z around 0 99.7%
Taylor expanded in x around 0 90.8%
if 3.8e-213 < z Initial program 99.9%
+-commutative99.9%
fma-define99.9%
Simplified99.9%
Taylor expanded in z around inf 81.8%
mul-1-neg81.8%
Simplified81.8%
(FPCore (x y z) :precision binary64 (if (or (<= z 4.4e-236) (not (<= z 4.5e-214))) (- (* x 0.5) (* y z)) (* y (+ 1.0 (log z)))))
double code(double x, double y, double z) {
double tmp;
if ((z <= 4.4e-236) || !(z <= 4.5e-214)) {
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 ((z <= 4.4d-236) .or. (.not. (z <= 4.5d-214))) 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 ((z <= 4.4e-236) || !(z <= 4.5e-214)) {
tmp = (x * 0.5) - (y * z);
} else {
tmp = y * (1.0 + Math.log(z));
}
return tmp;
}
def code(x, y, z): tmp = 0 if (z <= 4.4e-236) or not (z <= 4.5e-214): 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 ((z <= 4.4e-236) || !(z <= 4.5e-214)) 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 ((z <= 4.4e-236) || ~((z <= 4.5e-214))) 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[z, 4.4e-236], N[Not[LessEqual[z, 4.5e-214]], $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}\;z \leq 4.4 \cdot 10^{-236} \lor \neg \left(z \leq 4.5 \cdot 10^{-214}\right):\\
\;\;\;\;x \cdot 0.5 - y \cdot z\\
\mathbf{else}:\\
\;\;\;\;y \cdot \left(1 + \log z\right)\\
\end{array}
\end{array}
if z < 4.39999999999999985e-236Initial program 99.9%
Taylor expanded in z around inf 59.7%
associate-*r*59.7%
mul-1-neg59.7%
Simplified59.7%
distribute-lft-neg-out59.7%
unsub-neg59.7%
Applied egg-rr59.7%
if 4.39999999999999985e-236 < z < 4.5000000000000001e-214Initial program 99.7%
Taylor expanded in z around 0 99.7%
Taylor expanded in x around 0 90.8%
if 4.5000000000000001e-214 < z Initial program 99.9%
Taylor expanded in z around inf 81.8%
associate-*r*81.8%
mul-1-neg81.8%
Simplified81.8%
Final simplification79.3%
(FPCore (x y z) :precision binary64 (if (<= z 2.3) (+ (* 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 <= 2.3) {
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 <= 2.3) 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, 2.3], 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 2.3:\\
\;\;\;\;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 < 2.2999999999999998Initial program 99.8%
Taylor expanded in z around 0 99.7%
if 2.2999999999999998 < z Initial program 100.0%
+-commutative100.0%
fma-define100.0%
Simplified100.0%
Taylor expanded in z around inf 99.6%
mul-1-neg99.6%
Simplified99.6%
(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%
(FPCore (x y z) :precision binary64 (if (<= z 4.4e+23) (* x 0.5) (* y (- z))))
double code(double x, double y, double z) {
double tmp;
if (z <= 4.4e+23) {
tmp = x * 0.5;
} else {
tmp = 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 (z <= 4.4d+23) then
tmp = x * 0.5d0
else
tmp = y * -z
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double tmp;
if (z <= 4.4e+23) {
tmp = x * 0.5;
} else {
tmp = y * -z;
}
return tmp;
}
def code(x, y, z): tmp = 0 if z <= 4.4e+23: tmp = x * 0.5 else: tmp = y * -z return tmp
function code(x, y, z) tmp = 0.0 if (z <= 4.4e+23) tmp = Float64(x * 0.5); else tmp = Float64(y * Float64(-z)); end return tmp end
function tmp_2 = code(x, y, z) tmp = 0.0; if (z <= 4.4e+23) tmp = x * 0.5; else tmp = y * -z; end tmp_2 = tmp; end
code[x_, y_, z_] := If[LessEqual[z, 4.4e+23], N[(x * 0.5), $MachinePrecision], N[(y * (-z)), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq 4.4 \cdot 10^{+23}:\\
\;\;\;\;x \cdot 0.5\\
\mathbf{else}:\\
\;\;\;\;y \cdot \left(-z\right)\\
\end{array}
\end{array}
if z < 4.40000000000000017e23Initial program 99.8%
Taylor expanded in x around inf 56.1%
if 4.40000000000000017e23 < z Initial program 100.0%
Taylor expanded in z around inf 100.0%
associate-*r*100.0%
mul-1-neg100.0%
Simplified100.0%
Taylor expanded in y around inf 89.2%
+-commutative89.2%
mul-1-neg89.2%
unsub-neg89.2%
associate-*r/89.2%
*-commutative89.2%
associate-/l*89.2%
Simplified89.2%
Taylor expanded in x around 0 74.5%
neg-mul-174.5%
Simplified74.5%
Final simplification64.1%
(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%
Taylor expanded in z around inf 75.9%
associate-*r*75.9%
mul-1-neg75.9%
Simplified75.9%
distribute-lft-neg-out75.9%
unsub-neg75.9%
Applied egg-rr75.9%
(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 43.3%
Final simplification43.3%
(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 2024103
(FPCore (x y z)
:name "System.Random.MWC.Distributions:gamma from mwc-random-0.13.3.2"
:precision binary64
:alt
(- (+ y (* 0.5 x)) (* y (- z (log z))))
(+ (* x 0.5) (* y (+ (- 1.0 z) (log z)))))