diff options
Diffstat (limited to 'lib/util/roundup.c')
-rw-r--r-- | lib/util/roundup.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/lib/util/roundup.c b/lib/util/roundup.c new file mode 100644 index 0000000..0e7e8fd --- /dev/null +++ b/lib/util/roundup.c @@ -0,0 +1,48 @@ +/* + * SPDX-License-Identifier: ISC + * + * Copyright (c) 2019-2020 Todd C. Miller <Todd.Miller@sudo.ws> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +/* + * This is an open source non-commercial project. Dear PVS-Studio, please check it. + * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com + */ + +#include <config.h> + +#include "sudo_compat.h" +#include "sudo_debug.h" +#include "sudo_util.h" + +/* + * Round 32-bit unsigned length to the next highest power of two. + * Always returns at least 64. + * Algorithm from bit twiddling hacks. + */ +unsigned int +sudo_pow2_roundup_v1(unsigned int len) +{ + if (len < 64) + return 64; + len--; + len |= len >> 1; + len |= len >> 2; + len |= len >> 4; + len |= len >> 8; + len |= len >> 16; + len++; + return len; +} |