
(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%
Final simplification99.9%
(FPCore (x y z) :precision binary64 (if (or (<= y -1.7e+59) (not (<= y 1.75e-22))) (* y (- (+ 1.0 (log z)) z)) (fma y (- z) (* x 0.5))))
double code(double x, double y, double z) {
double tmp;
if ((y <= -1.7e+59) || !(y <= 1.75e-22)) {
tmp = y * ((1.0 + log(z)) - z);
} else {
tmp = fma(y, -z, (x * 0.5));
}
return tmp;
}
function code(x, y, z) tmp = 0.0 if ((y <= -1.7e+59) || !(y <= 1.75e-22)) tmp = Float64(y * Float64(Float64(1.0 + log(z)) - z)); else tmp = fma(y, Float64(-z), Float64(x * 0.5)); end return tmp end
code[x_, y_, z_] := If[Or[LessEqual[y, -1.7e+59], N[Not[LessEqual[y, 1.75e-22]], $MachinePrecision]], N[(y * N[(N[(1.0 + N[Log[z], $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]), $MachinePrecision], N[(y * (-z) + N[(x * 0.5), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -1.7 \cdot 10^{+59} \lor \neg \left(y \leq 1.75 \cdot 10^{-22}\right):\\
\;\;\;\;y \cdot \left(\left(1 + \log z\right) - z\right)\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(y, -z, x \cdot 0.5\right)\\
\end{array}
\end{array}
if y < -1.70000000000000003e59 or 1.75000000000000003e-22 < y Initial program 99.9%
Taylor expanded in x around inf 77.3%
associate-/l*77.2%
+-commutative77.2%
associate--l+77.2%
Simplified77.2%
Taylor expanded in x around 0 88.5%
if -1.70000000000000003e59 < y < 1.75000000000000003e-22Initial program 99.9%
+-commutative99.9%
fma-define99.9%
Simplified99.9%
Taylor expanded in z around inf 85.7%
mul-1-neg85.7%
Simplified85.7%
Final simplification86.9%
(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}
if z < 0.28000000000000003Initial program 99.8%
Taylor expanded in z around 0 98.1%
if 0.28000000000000003 < z Initial program 99.9%
+-commutative99.9%
fma-define100.0%
Simplified100.0%
Taylor expanded in z around inf 98.7%
mul-1-neg98.7%
Simplified98.7%
Final simplification98.4%
(FPCore (x y z) :precision binary64 (if (<= y -4e+227) (+ y (* y (log z))) (fma y (- z) (* x 0.5))))
double code(double x, double y, double z) {
double tmp;
if (y <= -4e+227) {
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 <= -4e+227) 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, -4e+227], 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 -4 \cdot 10^{+227}:\\
\;\;\;\;y + y \cdot \log z\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(y, -z, x \cdot 0.5\right)\\
\end{array}
\end{array}
if y < -4.0000000000000004e227Initial program 99.8%
distribute-rgt-in99.5%
fma-define99.5%
*-commutative99.5%
Applied egg-rr99.5%
Taylor expanded in x around 0 99.5%
Taylor expanded in z around 0 67.7%
if -4.0000000000000004e227 < y Initial program 99.9%
+-commutative99.9%
fma-define99.9%
Simplified99.9%
Taylor expanded in z around inf 77.8%
mul-1-neg77.8%
Simplified77.8%
Final simplification77.1%
(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 (if (<= y -4.8e+228) (+ y (* y (log z))) (- (* x 0.5) (* y z))))
double code(double x, double y, double z) {
double tmp;
if (y <= -4.8e+228) {
tmp = y + (y * 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 <= (-4.8d+228)) then
tmp = y + (y * 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 <= -4.8e+228) {
tmp = y + (y * Math.log(z));
} else {
tmp = (x * 0.5) - (y * z);
}
return tmp;
}
def code(x, y, z): tmp = 0 if y <= -4.8e+228: tmp = y + (y * math.log(z)) else: tmp = (x * 0.5) - (y * z) return tmp
function code(x, y, z) tmp = 0.0 if (y <= -4.8e+228) tmp = Float64(y + Float64(y * 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 <= -4.8e+228) tmp = y + (y * log(z)); else tmp = (x * 0.5) - (y * z); end tmp_2 = tmp; end
code[x_, y_, z_] := If[LessEqual[y, -4.8e+228], N[(y + N[(y * 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 -4.8 \cdot 10^{+228}:\\
\;\;\;\;y + y \cdot \log z\\
\mathbf{else}:\\
\;\;\;\;x \cdot 0.5 - y \cdot z\\
\end{array}
\end{array}
if y < -4.79999999999999977e228Initial program 99.8%
distribute-rgt-in99.5%
fma-define99.5%
*-commutative99.5%
Applied egg-rr99.5%
Taylor expanded in x around 0 99.5%
Taylor expanded in z around 0 67.7%
if -4.79999999999999977e228 < y Initial program 99.9%
Taylor expanded in z around inf 77.8%
associate-*r*77.8%
mul-1-neg77.8%
Simplified77.8%
distribute-lft-neg-out77.8%
unsub-neg77.8%
Applied egg-rr77.8%
Final simplification77.0%
(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 74.4%
associate-*r*74.4%
mul-1-neg74.4%
Simplified74.4%
distribute-lft-neg-out74.4%
unsub-neg74.4%
Applied egg-rr74.4%
Final simplification74.4%
(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 35.9%
Final simplification35.9%
(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 2024050
(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)))))