From 464df1d5e5ab1322e2dd0a7796939fff1aeefa9a Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 17:49:25 +0200 Subject: Adding upstream version 1.47.0. Signed-off-by: Daniel Baumann --- lib/ext2fs/bitops.c | 148 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 148 insertions(+) create mode 100644 lib/ext2fs/bitops.c (limited to 'lib/ext2fs/bitops.c') diff --git a/lib/ext2fs/bitops.c b/lib/ext2fs/bitops.c new file mode 100644 index 0000000..ce2acc4 --- /dev/null +++ b/lib/ext2fs/bitops.c @@ -0,0 +1,148 @@ +/* + * bitops.c --- Bitmap frobbing code. See bitops.h for the inlined + * routines. + * + * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o. + * + * %Begin-Header% + * This file may be redistributed under the terms of the GNU Library + * General Public License, version 2. + * %End-Header% + */ + +#include "config.h" +#include +#if HAVE_SYS_TYPES_H +#include +#endif + +#include "ext2_fs.h" +#include "ext2fs.h" + +/* + * C language bitmap functions written by Theodore Ts'o, 9/26/92. + * Modified by Pete A. Zaitcev 7/14/95 to be portable to big endian + * systems, as well as non-32 bit systems. + */ + +int ext2fs_set_bit(unsigned int nr,void * addr) +{ + int mask, retval; + unsigned char *ADDR = (unsigned char *) addr; + + ADDR += nr >> 3; + mask = 1 << (nr & 0x07); + retval = mask & *ADDR; + *ADDR |= mask; + return retval; +} + +int ext2fs_clear_bit(unsigned int nr, void * addr) +{ + int mask, retval; + unsigned char *ADDR = (unsigned char *) addr; + + ADDR += nr >> 3; + mask = 1 << (nr & 0x07); + retval = mask & *ADDR; + *ADDR &= ~mask; + return retval; +} + +int ext2fs_test_bit(unsigned int nr, const void * addr) +{ + int mask; + const unsigned char *ADDR = (const unsigned char *) addr; + + ADDR += nr >> 3; + mask = 1 << (nr & 0x07); + return (mask & *ADDR); +} + +void ext2fs_warn_bitmap(errcode_t errcode, unsigned long arg, + const char *description) +{ +#ifndef OMIT_COM_ERR + if (description) + com_err(0, errcode, "#%lu for %s", arg, description); + else + com_err(0, errcode, "#%lu", arg); +#endif +} + +/* Bitmap functions that take a 64-bit offset */ + +int ext2fs_set_bit64(__u64 nr, void * addr) +{ + int mask, retval; + unsigned char *ADDR = (unsigned char *) addr; + + ADDR += nr >> 3; + mask = 1 << (nr & 0x07); + retval = mask & *ADDR; + *ADDR |= mask; + return retval; +} + +int ext2fs_clear_bit64(__u64 nr, void * addr) +{ + int mask, retval; + unsigned char *ADDR = (unsigned char *) addr; + + ADDR += nr >> 3; + mask = 1 << (nr & 0x07); + retval = mask & *ADDR; + *ADDR &= ~mask; + return retval; +} + +int ext2fs_test_bit64(__u64 nr, const void * addr) +{ + int mask; + const unsigned char *ADDR = (const unsigned char *) addr; + + ADDR += nr >> 3; + mask = 1 << (nr & 0x07); + return (mask & *ADDR); +} + +static unsigned int popcount8(unsigned int w) +{ + unsigned int res = w - ((w >> 1) & 0x55); + res = (res & 0x33) + ((res >> 2) & 0x33); + return (res + (res >> 4)) & 0x0F; +} + +static unsigned int popcount32(unsigned int w) +{ + unsigned int res = w - ((w >> 1) & 0x55555555); + res = (res & 0x33333333) + ((res >> 2) & 0x33333333); + res = (res + (res >> 4)) & 0x0F0F0F0F; + res = res + (res >> 8); + return (res + (res >> 16)) & 0x000000FF; +} + +unsigned int ext2fs_bitcount(const void *addr, unsigned int nbytes) +{ + const unsigned char *cp = addr; + const __u32 *p; + unsigned int res = 0; + + while (((((uintptr_t) cp) & 3) != 0) && (nbytes > 0)) { + res += popcount8(*cp++); + nbytes--; + } + p = (const __u32 *) cp; + + while (nbytes > 4) { + res += popcount32(*p++); + nbytes -= 4; + } + cp = (const unsigned char *) p; + + while (nbytes > 0) { + res += popcount8(*cp++); + nbytes--; + } + return res; +} -- cgit v1.2.3