glibc/stdlib/drand48-iter.c
Paul Eggert 581c785bf3 Update copyright dates with scripts/update-copyrights
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
2022-01-01 11:40:24 -08:00

56 lines
1.7 KiB
C

/* Copyright (C) 1995-2022 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 <errno.h>
#include <stdlib.h>
#include <limits.h>
#include <stdint.h>
#include <sys/types.h>
/* Global state for non-reentrant functions. */
struct drand48_data __libc_drand48_data;
int
__drand48_iterate (unsigned short int xsubi[3], struct drand48_data *buffer)
{
uint64_t X;
uint64_t result;
/* Initialize buffer, if not yet done. */
if (__glibc_unlikely (!buffer->__init))
{
buffer->__a = 0x5deece66dull;
buffer->__c = 0xb;
buffer->__init = 1;
}
/* Do the real work. We choose a data type which contains at least
48 bits. Because we compute the modulus it does not care how
many bits really are computed. */
X = (uint64_t) xsubi[2] << 32 | (uint32_t) xsubi[1] << 16 | xsubi[0];
result = X * buffer->__a + buffer->__c;
xsubi[0] = result & 0xffff;
xsubi[1] = (result >> 16) & 0xffff;
xsubi[2] = (result >> 32) & 0xffff;
return 0;
}