
(FPCore (x y z)
:precision binary64
(+
(+ (- (* (- x 0.5) (log x)) x) 0.91893853320467)
(/
(+
(* (- (* (+ y 0.0007936500793651) z) 0.0027777777777778) z)
0.083333333333333)
x)))
double code(double x, double y, double z) {
return ((((x - 0.5) * log(x)) - x) + 0.91893853320467) + ((((((y + 0.0007936500793651) * z) - 0.0027777777777778) * z) + 0.083333333333333) / x);
}
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) * log(x)) - x) + 0.91893853320467d0) + ((((((y + 0.0007936500793651d0) * z) - 0.0027777777777778d0) * z) + 0.083333333333333d0) / x)
end function
public static double code(double x, double y, double z) {
return ((((x - 0.5) * Math.log(x)) - x) + 0.91893853320467) + ((((((y + 0.0007936500793651) * z) - 0.0027777777777778) * z) + 0.083333333333333) / x);
}
def code(x, y, z): return ((((x - 0.5) * math.log(x)) - x) + 0.91893853320467) + ((((((y + 0.0007936500793651) * z) - 0.0027777777777778) * z) + 0.083333333333333) / x)
function code(x, y, z) return Float64(Float64(Float64(Float64(Float64(x - 0.5) * log(x)) - x) + 0.91893853320467) + Float64(Float64(Float64(Float64(Float64(Float64(y + 0.0007936500793651) * z) - 0.0027777777777778) * z) + 0.083333333333333) / x)) end
function tmp = code(x, y, z) tmp = ((((x - 0.5) * log(x)) - x) + 0.91893853320467) + ((((((y + 0.0007936500793651) * z) - 0.0027777777777778) * z) + 0.083333333333333) / x); end
code[x_, y_, z_] := N[(N[(N[(N[(N[(x - 0.5), $MachinePrecision] * N[Log[x], $MachinePrecision]), $MachinePrecision] - x), $MachinePrecision] + 0.91893853320467), $MachinePrecision] + N[(N[(N[(N[(N[(N[(y + 0.0007936500793651), $MachinePrecision] * z), $MachinePrecision] - 0.0027777777777778), $MachinePrecision] * z), $MachinePrecision] + 0.083333333333333), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(\left(\left(x - 0.5\right) \cdot \log x - x\right) + 0.91893853320467\right) + \frac{\left(\left(y + 0.0007936500793651\right) \cdot z - 0.0027777777777778\right) \cdot z + 0.083333333333333}{x}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 22 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y z)
:precision binary64
(+
(+ (- (* (- x 0.5) (log x)) x) 0.91893853320467)
(/
(+
(* (- (* (+ y 0.0007936500793651) z) 0.0027777777777778) z)
0.083333333333333)
x)))
double code(double x, double y, double z) {
return ((((x - 0.5) * log(x)) - x) + 0.91893853320467) + ((((((y + 0.0007936500793651) * z) - 0.0027777777777778) * z) + 0.083333333333333) / x);
}
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) * log(x)) - x) + 0.91893853320467d0) + ((((((y + 0.0007936500793651d0) * z) - 0.0027777777777778d0) * z) + 0.083333333333333d0) / x)
end function
public static double code(double x, double y, double z) {
return ((((x - 0.5) * Math.log(x)) - x) + 0.91893853320467) + ((((((y + 0.0007936500793651) * z) - 0.0027777777777778) * z) + 0.083333333333333) / x);
}
def code(x, y, z): return ((((x - 0.5) * math.log(x)) - x) + 0.91893853320467) + ((((((y + 0.0007936500793651) * z) - 0.0027777777777778) * z) + 0.083333333333333) / x)
function code(x, y, z) return Float64(Float64(Float64(Float64(Float64(x - 0.5) * log(x)) - x) + 0.91893853320467) + Float64(Float64(Float64(Float64(Float64(Float64(y + 0.0007936500793651) * z) - 0.0027777777777778) * z) + 0.083333333333333) / x)) end
function tmp = code(x, y, z) tmp = ((((x - 0.5) * log(x)) - x) + 0.91893853320467) + ((((((y + 0.0007936500793651) * z) - 0.0027777777777778) * z) + 0.083333333333333) / x); end
code[x_, y_, z_] := N[(N[(N[(N[(N[(x - 0.5), $MachinePrecision] * N[Log[x], $MachinePrecision]), $MachinePrecision] - x), $MachinePrecision] + 0.91893853320467), $MachinePrecision] + N[(N[(N[(N[(N[(N[(y + 0.0007936500793651), $MachinePrecision] * z), $MachinePrecision] - 0.0027777777777778), $MachinePrecision] * z), $MachinePrecision] + 0.083333333333333), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(\left(\left(x - 0.5\right) \cdot \log x - x\right) + 0.91893853320467\right) + \frac{\left(\left(y + 0.0007936500793651\right) \cdot z - 0.0027777777777778\right) \cdot z + 0.083333333333333}{x}
\end{array}
(FPCore (x y z)
:precision binary64
(if (<= x 2e+14)
(-
(+
(/
(fma
z
(fma (+ y 0.0007936500793651) z -0.0027777777777778)
0.083333333333333)
x)
(* (log x) (+ x -0.5)))
(+ x -0.91893853320467))
(+ (- (* x (log x)) x) (* z (* z (/ (+ y 0.0007936500793651) x))))))
double code(double x, double y, double z) {
double tmp;
if (x <= 2e+14) {
tmp = ((fma(z, fma((y + 0.0007936500793651), z, -0.0027777777777778), 0.083333333333333) / x) + (log(x) * (x + -0.5))) - (x + -0.91893853320467);
} else {
tmp = ((x * log(x)) - x) + (z * (z * ((y + 0.0007936500793651) / x)));
}
return tmp;
}
function code(x, y, z) tmp = 0.0 if (x <= 2e+14) tmp = Float64(Float64(Float64(fma(z, fma(Float64(y + 0.0007936500793651), z, -0.0027777777777778), 0.083333333333333) / x) + Float64(log(x) * Float64(x + -0.5))) - Float64(x + -0.91893853320467)); else tmp = Float64(Float64(Float64(x * log(x)) - x) + Float64(z * Float64(z * Float64(Float64(y + 0.0007936500793651) / x)))); end return tmp end
code[x_, y_, z_] := If[LessEqual[x, 2e+14], N[(N[(N[(N[(z * N[(N[(y + 0.0007936500793651), $MachinePrecision] * z + -0.0027777777777778), $MachinePrecision] + 0.083333333333333), $MachinePrecision] / x), $MachinePrecision] + N[(N[Log[x], $MachinePrecision] * N[(x + -0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(x + -0.91893853320467), $MachinePrecision]), $MachinePrecision], N[(N[(N[(x * N[Log[x], $MachinePrecision]), $MachinePrecision] - x), $MachinePrecision] + N[(z * N[(z * N[(N[(y + 0.0007936500793651), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq 2 \cdot 10^{+14}:\\
\;\;\;\;\left(\frac{\mathsf{fma}\left(z, \mathsf{fma}\left(y + 0.0007936500793651, z, -0.0027777777777778\right), 0.083333333333333\right)}{x} + \log x \cdot \left(x + -0.5\right)\right) - \left(x + -0.91893853320467\right)\\
\mathbf{else}:\\
\;\;\;\;\left(x \cdot \log x - x\right) + z \cdot \left(z \cdot \frac{y + 0.0007936500793651}{x}\right)\\
\end{array}
\end{array}
if x < 2e14Initial program 99.7%
lift-+.f64N/A
+-commutativeN/A
lift-+.f64N/A
lift--.f64N/A
associate-+l-N/A
associate-+r-N/A
lower--.f64N/A
Applied rewrites99.7%
if 2e14 < x Initial program 89.2%
Taylor expanded in z around inf
associate-/l*N/A
unpow2N/A
associate-*l*N/A
associate-*r/N/A
lower-*.f64N/A
associate-*r/N/A
lower-*.f64N/A
lower-/.f64N/A
lower-+.f6499.6
Applied rewrites99.6%
Taylor expanded in x around inf
sub-negN/A
metadata-evalN/A
distribute-rgt-inN/A
neg-mul-1N/A
unsub-negN/A
lower--.f64N/A
*-commutativeN/A
lower-*.f64N/A
mul-1-negN/A
log-recN/A
remove-double-negN/A
lower-log.f6499.6
Applied rewrites99.6%
Final simplification99.6%
(FPCore (x y z)
:precision binary64
(let* ((t_0
(+
(/
(+
0.083333333333333
(* z (- (* z (+ y 0.0007936500793651)) 0.0027777777777778)))
x)
(+ 0.91893853320467 (- (* (log x) (- x 0.5)) x)))))
(if (<= t_0 -2e+44)
(*
z
(*
z
(/
(+
(+ y (/ 0.083333333333333 (* z z)))
(+ 0.0007936500793651 (/ -0.0027777777777778 z)))
x)))
(if (<= t_0 5e+306)
(+
0.91893853320467
(fma (log x) (+ x -0.5) (- (/ 1.0 (* x 12.000000000000048)) x)))
(* (+ y 0.0007936500793651) (* z (/ z x)))))))
double code(double x, double y, double z) {
double t_0 = ((0.083333333333333 + (z * ((z * (y + 0.0007936500793651)) - 0.0027777777777778))) / x) + (0.91893853320467 + ((log(x) * (x - 0.5)) - x));
double tmp;
if (t_0 <= -2e+44) {
tmp = z * (z * (((y + (0.083333333333333 / (z * z))) + (0.0007936500793651 + (-0.0027777777777778 / z))) / x));
} else if (t_0 <= 5e+306) {
tmp = 0.91893853320467 + fma(log(x), (x + -0.5), ((1.0 / (x * 12.000000000000048)) - x));
} else {
tmp = (y + 0.0007936500793651) * (z * (z / x));
}
return tmp;
}
function code(x, y, z) t_0 = Float64(Float64(Float64(0.083333333333333 + Float64(z * Float64(Float64(z * Float64(y + 0.0007936500793651)) - 0.0027777777777778))) / x) + Float64(0.91893853320467 + Float64(Float64(log(x) * Float64(x - 0.5)) - x))) tmp = 0.0 if (t_0 <= -2e+44) tmp = Float64(z * Float64(z * Float64(Float64(Float64(y + Float64(0.083333333333333 / Float64(z * z))) + Float64(0.0007936500793651 + Float64(-0.0027777777777778 / z))) / x))); elseif (t_0 <= 5e+306) tmp = Float64(0.91893853320467 + fma(log(x), Float64(x + -0.5), Float64(Float64(1.0 / Float64(x * 12.000000000000048)) - x))); else tmp = Float64(Float64(y + 0.0007936500793651) * Float64(z * Float64(z / x))); end return tmp end
code[x_, y_, z_] := Block[{t$95$0 = N[(N[(N[(0.083333333333333 + N[(z * N[(N[(z * N[(y + 0.0007936500793651), $MachinePrecision]), $MachinePrecision] - 0.0027777777777778), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision] + N[(0.91893853320467 + N[(N[(N[Log[x], $MachinePrecision] * N[(x - 0.5), $MachinePrecision]), $MachinePrecision] - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -2e+44], N[(z * N[(z * N[(N[(N[(y + N[(0.083333333333333 / N[(z * z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.0007936500793651 + N[(-0.0027777777777778 / z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$0, 5e+306], N[(0.91893853320467 + N[(N[Log[x], $MachinePrecision] * N[(x + -0.5), $MachinePrecision] + N[(N[(1.0 / N[(x * 12.000000000000048), $MachinePrecision]), $MachinePrecision] - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(y + 0.0007936500793651), $MachinePrecision] * N[(z * N[(z / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{0.083333333333333 + z \cdot \left(z \cdot \left(y + 0.0007936500793651\right) - 0.0027777777777778\right)}{x} + \left(0.91893853320467 + \left(\log x \cdot \left(x - 0.5\right) - x\right)\right)\\
\mathbf{if}\;t\_0 \leq -2 \cdot 10^{+44}:\\
\;\;\;\;z \cdot \left(z \cdot \frac{\left(y + \frac{0.083333333333333}{z \cdot z}\right) + \left(0.0007936500793651 + \frac{-0.0027777777777778}{z}\right)}{x}\right)\\
\mathbf{elif}\;t\_0 \leq 5 \cdot 10^{+306}:\\
\;\;\;\;0.91893853320467 + \mathsf{fma}\left(\log x, x + -0.5, \frac{1}{x \cdot 12.000000000000048} - x\right)\\
\mathbf{else}:\\
\;\;\;\;\left(y + 0.0007936500793651\right) \cdot \left(z \cdot \frac{z}{x}\right)\\
\end{array}
\end{array}
if (+.f64 (+.f64 (-.f64 (*.f64 (-.f64 x #s(literal 1/2 binary64)) (log.f64 x)) x) #s(literal 91893853320467/100000000000000 binary64)) (/.f64 (+.f64 (*.f64 (-.f64 (*.f64 (+.f64 y #s(literal 7936500793651/10000000000000000 binary64)) z) #s(literal 13888888888889/5000000000000000 binary64)) z) #s(literal 83333333333333/1000000000000000 binary64)) x)) < -2.0000000000000002e44Initial program 89.2%
Taylor expanded in z around -inf
Applied rewrites95.2%
Taylor expanded in z around 0
Applied rewrites5.6%
Taylor expanded in x around 0
Applied rewrites90.8%
if -2.0000000000000002e44 < (+.f64 (+.f64 (-.f64 (*.f64 (-.f64 x #s(literal 1/2 binary64)) (log.f64 x)) x) #s(literal 91893853320467/100000000000000 binary64)) (/.f64 (+.f64 (*.f64 (-.f64 (*.f64 (+.f64 y #s(literal 7936500793651/10000000000000000 binary64)) z) #s(literal 13888888888889/5000000000000000 binary64)) z) #s(literal 83333333333333/1000000000000000 binary64)) x)) < 4.99999999999999993e306Initial program 99.4%
Taylor expanded in z around 0
associate--l+N/A
lower-+.f64N/A
+-commutativeN/A
associate--l+N/A
lower-fma.f64N/A
lower-log.f64N/A
sub-negN/A
metadata-evalN/A
+-commutativeN/A
lower-+.f64N/A
lower--.f64N/A
associate-*r/N/A
metadata-evalN/A
lower-/.f6488.0
Applied rewrites88.0%
Applied rewrites88.0%
if 4.99999999999999993e306 < (+.f64 (+.f64 (-.f64 (*.f64 (-.f64 x #s(literal 1/2 binary64)) (log.f64 x)) x) #s(literal 91893853320467/100000000000000 binary64)) (/.f64 (+.f64 (*.f64 (-.f64 (*.f64 (+.f64 y #s(literal 7936500793651/10000000000000000 binary64)) z) #s(literal 13888888888889/5000000000000000 binary64)) z) #s(literal 83333333333333/1000000000000000 binary64)) x)) Initial program 85.1%
lift-+.f64N/A
+-commutativeN/A
lift-+.f64N/A
lift--.f64N/A
associate-+l-N/A
associate-+r-N/A
lower--.f64N/A
Applied rewrites85.1%
Taylor expanded in z around inf
*-commutativeN/A
lower-*.f64N/A
lower-+.f64N/A
associate-*r/N/A
metadata-evalN/A
lower-/.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f6485.0
Applied rewrites85.0%
Taylor expanded in z around inf
distribute-rgt-inN/A
associate-*r/N/A
metadata-evalN/A
associate-*l/N/A
associate-*r/N/A
associate-*l/N/A
associate-/l*N/A
distribute-rgt-outN/A
lower-*.f64N/A
unpow2N/A
associate-/l*N/A
lower-*.f64N/A
lower-/.f64N/A
lower-+.f6489.3
Applied rewrites89.3%
Final simplification88.7%
(FPCore (x y z) :precision binary64 (+ (+ (+ (* (- x 0.5) (log x)) (- 0.91893853320467 x)) (/ 0.083333333333333 x)) (* (/ z x) (- (* z (+ y 0.0007936500793651)) 0.0027777777777778))))
double code(double x, double y, double z) {
return ((((x - 0.5) * log(x)) + (0.91893853320467 - x)) + (0.083333333333333 / x)) + ((z / x) * ((z * (y + 0.0007936500793651)) - 0.0027777777777778));
}
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) * log(x)) + (0.91893853320467d0 - x)) + (0.083333333333333d0 / x)) + ((z / x) * ((z * (y + 0.0007936500793651d0)) - 0.0027777777777778d0))
end function
public static double code(double x, double y, double z) {
return ((((x - 0.5) * Math.log(x)) + (0.91893853320467 - x)) + (0.083333333333333 / x)) + ((z / x) * ((z * (y + 0.0007936500793651)) - 0.0027777777777778));
}
def code(x, y, z): return ((((x - 0.5) * math.log(x)) + (0.91893853320467 - x)) + (0.083333333333333 / x)) + ((z / x) * ((z * (y + 0.0007936500793651)) - 0.0027777777777778))
function code(x, y, z) return Float64(Float64(Float64(Float64(Float64(x - 0.5) * log(x)) + Float64(0.91893853320467 - x)) + Float64(0.083333333333333 / x)) + Float64(Float64(z / x) * Float64(Float64(z * Float64(y + 0.0007936500793651)) - 0.0027777777777778))) end
function tmp = code(x, y, z) tmp = ((((x - 0.5) * log(x)) + (0.91893853320467 - x)) + (0.083333333333333 / x)) + ((z / x) * ((z * (y + 0.0007936500793651)) - 0.0027777777777778)); end
code[x_, y_, z_] := N[(N[(N[(N[(N[(x - 0.5), $MachinePrecision] * N[Log[x], $MachinePrecision]), $MachinePrecision] + N[(0.91893853320467 - x), $MachinePrecision]), $MachinePrecision] + N[(0.083333333333333 / x), $MachinePrecision]), $MachinePrecision] + N[(N[(z / x), $MachinePrecision] * N[(N[(z * N[(y + 0.0007936500793651), $MachinePrecision]), $MachinePrecision] - 0.0027777777777778), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(\left(\left(x - 0.5\right) \cdot \log x + \left(0.91893853320467 - x\right)\right) + \frac{0.083333333333333}{x}\right) + \frac{z}{x} \cdot \left(z \cdot \left(y + 0.0007936500793651\right) - 0.0027777777777778\right)
\end{array}
herbie shell --seed 2024228
(FPCore (x y z)
:name "Numeric.SpecFunctions:$slogFactorial from math-functions-0.1.5.2, B"
:precision binary64
:alt
(! :herbie-platform default (+ (+ (+ (* (- x 1/2) (log x)) (- 91893853320467/100000000000000 x)) (/ 83333333333333/1000000000000000 x)) (* (/ z x) (- (* z (+ y 7936500793651/10000000000000000)) 13888888888889/5000000000000000))))
(+ (+ (- (* (- x 0.5) (log x)) x) 0.91893853320467) (/ (+ (* (- (* (+ y 0.0007936500793651) z) 0.0027777777777778) z) 0.083333333333333) x)))