581c785bf3
I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 7061 files FOO. I then removed trailing white space from math/tgmath.h, support/tst-support-open-dev-null-range.c, and sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following obscure pre-commit check failure diagnostics from Savannah. I don't know why I run into these diagnostics whereas others evidently do not. remote: *** 912-#endif remote: *** 913: remote: *** 914- remote: *** error: lines with trailing whitespace found ... remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
53 lines
2 KiB
C
53 lines
2 KiB
C
/* Compute a product of 1 + (T/X), 1 + (T/(X+1)), ....
|
|
Copyright (C) 2015-2022 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <math.h>
|
|
#include <math_private.h>
|
|
#include <mul_splitl.h>
|
|
|
|
/* Compute the product of 1 + (T / (X + X_EPS)), 1 + (T / (X + X_EPS +
|
|
1)), ..., 1 + (T / (X + X_EPS + N - 1)), minus 1. X is such that
|
|
all the values X + 1, ..., X + N - 1 are exactly representable, and
|
|
X_EPS / X is small enough that factors quadratic in it can be
|
|
neglected. */
|
|
|
|
long double
|
|
__lgamma_productl (long double t, long double x, long double x_eps, int n)
|
|
{
|
|
long double ret = 0, ret_eps = 0;
|
|
for (int i = 0; i < n; i++)
|
|
{
|
|
long double xi = x + i;
|
|
long double quot = t / xi;
|
|
long double mhi, mlo;
|
|
mul_splitl (&mhi, &mlo, quot, xi);
|
|
long double quot_lo = (t - mhi - mlo) / xi - t * x_eps / (xi * xi);
|
|
/* We want (1 + RET + RET_EPS) * (1 + QUOT + QUOT_LO) - 1. */
|
|
long double rhi, rlo;
|
|
mul_splitl (&rhi, &rlo, ret, quot);
|
|
long double rpq = ret + quot;
|
|
long double rpq_eps = (ret - rpq) + quot;
|
|
long double nret = rpq + rhi;
|
|
long double nret_eps = (rpq - nret) + rhi;
|
|
ret_eps += (rpq_eps + nret_eps + rlo + ret_eps * quot
|
|
+ quot_lo + quot_lo * (ret + ret_eps));
|
|
ret = nret;
|
|
}
|
|
return ret + ret_eps;
|
|
}
|