
(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 (log z) y (fma (- 1.0 z) y (* 0.5 x))))
double code(double x, double y, double z) {
return fma(log(z), y, fma((1.0 - z), y, (0.5 * x)));
}
function code(x, y, z) return fma(log(z), y, fma(Float64(1.0 - z), y, Float64(0.5 * x))) end
code[x_, y_, z_] := N[(N[Log[z], $MachinePrecision] * y + N[(N[(1.0 - z), $MachinePrecision] * y + N[(0.5 * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\log z, y, \mathsf{fma}\left(1 - z, y, 0.5 \cdot x\right)\right)
\end{array}
Initial program 99.9%
lift-+.f64N/A
+-commutativeN/A
lift-*.f64N/A
lift-+.f64N/A
+-commutativeN/A
distribute-rgt-inN/A
associate-+l+N/A
lower-fma.f64N/A
lower-fma.f6499.9
lift-*.f64N/A
*-commutativeN/A
lower-*.f6499.9
Applied rewrites99.9%
(FPCore (x y z) :precision binary64 (if (<= (+ (- 1.0 z) (log z)) -40000000000.0) (fma (- z) y (* 0.5 x)) (fma 0.5 x (fma (log z) y y))))
double code(double x, double y, double z) {
double tmp;
if (((1.0 - z) + log(z)) <= -40000000000.0) {
tmp = fma(-z, y, (0.5 * x));
} else {
tmp = fma(0.5, x, fma(log(z), y, y));
}
return tmp;
}
function code(x, y, z) tmp = 0.0 if (Float64(Float64(1.0 - z) + log(z)) <= -40000000000.0) tmp = fma(Float64(-z), y, Float64(0.5 * x)); else tmp = fma(0.5, x, fma(log(z), y, y)); end return tmp end
code[x_, y_, z_] := If[LessEqual[N[(N[(1.0 - z), $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision], -40000000000.0], N[((-z) * y + N[(0.5 * x), $MachinePrecision]), $MachinePrecision], N[(0.5 * x + N[(N[Log[z], $MachinePrecision] * y + y), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\left(1 - z\right) + \log z \leq -40000000000:\\
\;\;\;\;\mathsf{fma}\left(-z, y, 0.5 \cdot x\right)\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(0.5, x, \mathsf{fma}\left(\log z, y, y\right)\right)\\
\end{array}
\end{array}
if (+.f64 (-.f64 #s(literal 1 binary64) z) (log.f64 z)) < -4e10Initial program 100.0%
Taylor expanded in z around inf
mul-1-negN/A
lower-neg.f6499.6
Applied rewrites99.6%
lift-+.f64N/A
+-commutativeN/A
lift-*.f64N/A
*-commutativeN/A
lift-*.f64N/A
*-commutativeN/A
lower-fma.f64N/A
lower-*.f6499.6
Applied rewrites99.6%
if -4e10 < (+.f64 (-.f64 #s(literal 1 binary64) z) (log.f64 z)) Initial program 99.8%
Taylor expanded in z around 0
lower-fma.f64N/A
+-commutativeN/A
distribute-rgt-inN/A
*-lft-identityN/A
lower-fma.f64N/A
lower-log.f6499.3
Applied rewrites99.3%
(FPCore (x y z) :precision binary64 (if (or (<= y -6.4e+86) (not (<= y 3.5e+46))) (fma (- (log z) z) y y) (fma (- z) y (* 0.5 x))))
double code(double x, double y, double z) {
double tmp;
if ((y <= -6.4e+86) || !(y <= 3.5e+46)) {
tmp = fma((log(z) - z), y, y);
} else {
tmp = fma(-z, y, (0.5 * x));
}
return tmp;
}
function code(x, y, z) tmp = 0.0 if ((y <= -6.4e+86) || !(y <= 3.5e+46)) tmp = fma(Float64(log(z) - z), y, y); else tmp = fma(Float64(-z), y, Float64(0.5 * x)); end return tmp end
code[x_, y_, z_] := If[Or[LessEqual[y, -6.4e+86], N[Not[LessEqual[y, 3.5e+46]], $MachinePrecision]], N[(N[(N[Log[z], $MachinePrecision] - z), $MachinePrecision] * y + y), $MachinePrecision], N[((-z) * y + N[(0.5 * x), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -6.4 \cdot 10^{+86} \lor \neg \left(y \leq 3.5 \cdot 10^{+46}\right):\\
\;\;\;\;\mathsf{fma}\left(\log z - z, y, y\right)\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(-z, y, 0.5 \cdot x\right)\\
\end{array}
\end{array}
if y < -6.4000000000000001e86 or 3.49999999999999985e46 < y Initial program 99.8%
Taylor expanded in x around 0
sub-negN/A
associate-+r+N/A
mul-1-negN/A
+-commutativeN/A
distribute-rgt-inN/A
*-lft-identityN/A
lower-fma.f64N/A
mul-1-negN/A
sub-negN/A
lower--.f64N/A
lower-log.f6490.5
Applied rewrites90.5%
if -6.4000000000000001e86 < y < 3.49999999999999985e46Initial program 100.0%
Taylor expanded in z around inf
mul-1-negN/A
lower-neg.f6490.6
Applied rewrites90.6%
lift-+.f64N/A
+-commutativeN/A
lift-*.f64N/A
*-commutativeN/A
lift-*.f64N/A
*-commutativeN/A
lower-fma.f64N/A
lower-*.f6490.6
Applied rewrites90.6%
Final simplification90.6%
(FPCore (x y z) :precision binary64 (if (<= (+ (- 1.0 z) (log z)) -5e+46) (* (- z) y) (* 0.5 x)))
double code(double x, double y, double z) {
double tmp;
if (((1.0 - z) + log(z)) <= -5e+46) {
tmp = -z * y;
} else {
tmp = 0.5 * x;
}
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 (((1.0d0 - z) + log(z)) <= (-5d+46)) then
tmp = -z * y
else
tmp = 0.5d0 * x
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double tmp;
if (((1.0 - z) + Math.log(z)) <= -5e+46) {
tmp = -z * y;
} else {
tmp = 0.5 * x;
}
return tmp;
}
def code(x, y, z): tmp = 0 if ((1.0 - z) + math.log(z)) <= -5e+46: tmp = -z * y else: tmp = 0.5 * x return tmp
function code(x, y, z) tmp = 0.0 if (Float64(Float64(1.0 - z) + log(z)) <= -5e+46) tmp = Float64(Float64(-z) * y); else tmp = Float64(0.5 * x); end return tmp end
function tmp_2 = code(x, y, z) tmp = 0.0; if (((1.0 - z) + log(z)) <= -5e+46) tmp = -z * y; else tmp = 0.5 * x; end tmp_2 = tmp; end
code[x_, y_, z_] := If[LessEqual[N[(N[(1.0 - z), $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision], -5e+46], N[((-z) * y), $MachinePrecision], N[(0.5 * x), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\left(1 - z\right) + \log z \leq -5 \cdot 10^{+46}:\\
\;\;\;\;\left(-z\right) \cdot y\\
\mathbf{else}:\\
\;\;\;\;0.5 \cdot x\\
\end{array}
\end{array}
if (+.f64 (-.f64 #s(literal 1 binary64) z) (log.f64 z)) < -5.0000000000000002e46Initial program 100.0%
Taylor expanded in z around inf
mul-1-negN/A
*-commutativeN/A
distribute-lft-neg-inN/A
lower-*.f64N/A
lower-neg.f6478.4
Applied rewrites78.4%
if -5.0000000000000002e46 < (+.f64 (-.f64 #s(literal 1 binary64) z) (log.f64 z)) Initial program 99.8%
lift-+.f64N/A
+-commutativeN/A
lift-*.f64N/A
lift-+.f64N/A
+-commutativeN/A
distribute-rgt-inN/A
associate-+l+N/A
lower-fma.f64N/A
lower-fma.f6499.8
lift-*.f64N/A
*-commutativeN/A
lower-*.f6499.8
Applied rewrites99.8%
Taylor expanded in x around inf
*-commutativeN/A
lower-*.f64N/A
+-commutativeN/A
*-commutativeN/A
associate-/l*N/A
*-commutativeN/A
associate-/l*N/A
distribute-rgt-outN/A
associate-+r-N/A
+-commutativeN/A
lower-fma.f64N/A
lower-/.f64N/A
lower--.f64N/A
+-commutativeN/A
lower-+.f64N/A
lower-log.f6490.9
Applied rewrites90.9%
Taylor expanded in x around inf
Applied rewrites56.1%
Final simplification66.5%
(FPCore (x y z) :precision binary64 (fma (- (log z) z) y (fma 0.5 x y)))
double code(double x, double y, double z) {
return fma((log(z) - z), y, fma(0.5, x, y));
}
function code(x, y, z) return fma(Float64(log(z) - z), y, fma(0.5, x, y)) end
code[x_, y_, z_] := N[(N[(N[Log[z], $MachinePrecision] - z), $MachinePrecision] * y + N[(0.5 * x + y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\log z - z, y, \mathsf{fma}\left(0.5, x, y\right)\right)
\end{array}
Initial program 99.9%
Taylor expanded in x around 0
sub-negN/A
associate-+r+N/A
mul-1-negN/A
distribute-lft-inN/A
*-rgt-identityN/A
associate-+r+N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
mul-1-negN/A
sub-negN/A
lower--.f64N/A
lower-log.f64N/A
lower-fma.f6499.9
Applied rewrites99.9%
(FPCore (x y z) :precision binary64 (fma (- z) y (* 0.5 x)))
double code(double x, double y, double z) {
return fma(-z, y, (0.5 * x));
}
function code(x, y, z) return fma(Float64(-z), y, Float64(0.5 * x)) end
code[x_, y_, z_] := N[((-z) * y + N[(0.5 * x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-z, y, 0.5 \cdot x\right)
\end{array}
Initial program 99.9%
Taylor expanded in z around inf
mul-1-negN/A
lower-neg.f6478.8
Applied rewrites78.8%
lift-+.f64N/A
+-commutativeN/A
lift-*.f64N/A
*-commutativeN/A
lift-*.f64N/A
*-commutativeN/A
lower-fma.f64N/A
lower-*.f6478.8
Applied rewrites78.8%
(FPCore (x y z) :precision binary64 (* 0.5 x))
double code(double x, double y, double z) {
return 0.5 * x;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = 0.5d0 * x
end function
public static double code(double x, double y, double z) {
return 0.5 * x;
}
def code(x, y, z): return 0.5 * x
function code(x, y, z) return Float64(0.5 * x) end
function tmp = code(x, y, z) tmp = 0.5 * x; end
code[x_, y_, z_] := N[(0.5 * x), $MachinePrecision]
\begin{array}{l}
\\
0.5 \cdot x
\end{array}
Initial program 99.9%
lift-+.f64N/A
+-commutativeN/A
lift-*.f64N/A
lift-+.f64N/A
+-commutativeN/A
distribute-rgt-inN/A
associate-+l+N/A
lower-fma.f64N/A
lower-fma.f6499.9
lift-*.f64N/A
*-commutativeN/A
lower-*.f6499.9
Applied rewrites99.9%
Taylor expanded in x around inf
*-commutativeN/A
lower-*.f64N/A
+-commutativeN/A
*-commutativeN/A
associate-/l*N/A
*-commutativeN/A
associate-/l*N/A
distribute-rgt-outN/A
associate-+r-N/A
+-commutativeN/A
lower-fma.f64N/A
lower-/.f64N/A
lower--.f64N/A
+-commutativeN/A
lower-+.f64N/A
lower-log.f6489.2
Applied rewrites89.2%
Taylor expanded in x around inf
Applied rewrites40.8%
Final simplification40.8%
(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 2024318
(FPCore (x y z)
:name "System.Random.MWC.Distributions:gamma from mwc-random-0.13.3.2"
:precision binary64
:alt
(! :herbie-platform default (- (+ y (* 1/2 x)) (* y (- z (log z)))))
(+ (* x 0.5) (* y (+ (- 1.0 z) (log z)))))