mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 10:49:33 +00:00
Staging: echo: remove bit_operations.h
This file is no longer needed, thanks to the work done by David. Cc: David Rowe <david@rowetel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
parent
196e76e86a
commit
248ed329ac
1 changed files with 0 additions and 226 deletions
|
@ -1,226 +0,0 @@
|
|||
/*
|
||||
* SpanDSP - a series of DSP components for telephony
|
||||
*
|
||||
* bit_operations.h - Various bit level operations, such as bit reversal
|
||||
*
|
||||
* Written by Steve Underwood <steveu@coppice.org>
|
||||
*
|
||||
* Copyright (C) 2006 Steve Underwood
|
||||
*
|
||||
* All rights reserved.
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License version 2, as
|
||||
* published by the Free Software Foundation.
|
||||
*
|
||||
* This program 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 General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program; if not, write to the Free Software
|
||||
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
||||
*/
|
||||
|
||||
/*! \file */
|
||||
|
||||
#if !defined(_BIT_OPERATIONS_H_)
|
||||
#define _BIT_OPERATIONS_H_
|
||||
|
||||
#if defined(__i386__) || defined(__x86_64__)
|
||||
/*! \brief Find the bit position of the highest set bit in a word
|
||||
\param bits The word to be searched
|
||||
\return The bit number of the highest set bit, or -1 if the word is zero. */
|
||||
static inline int top_bit(unsigned int bits)
|
||||
{
|
||||
int res;
|
||||
|
||||
__asm__(" xorl %[res],%[res];\n"
|
||||
" decl %[res];\n"
|
||||
" bsrl %[bits],%[res]\n"
|
||||
:[res] "=&r" (res)
|
||||
:[bits] "rm"(bits)
|
||||
);
|
||||
return res;
|
||||
}
|
||||
|
||||
/*! \brief Find the bit position of the lowest set bit in a word
|
||||
\param bits The word to be searched
|
||||
\return The bit number of the lowest set bit, or -1 if the word is zero. */
|
||||
static inline int bottom_bit(unsigned int bits)
|
||||
{
|
||||
int res;
|
||||
|
||||
__asm__(" xorl %[res],%[res];\n"
|
||||
" decl %[res];\n"
|
||||
" bsfl %[bits],%[res]\n"
|
||||
:[res] "=&r" (res)
|
||||
:[bits] "rm"(bits)
|
||||
);
|
||||
return res;
|
||||
}
|
||||
#else
|
||||
static inline int top_bit(unsigned int bits)
|
||||
{
|
||||
int i;
|
||||
|
||||
if (bits == 0)
|
||||
return -1;
|
||||
i = 0;
|
||||
if (bits & 0xFFFF0000) {
|
||||
bits &= 0xFFFF0000;
|
||||
i += 16;
|
||||
}
|
||||
if (bits & 0xFF00FF00) {
|
||||
bits &= 0xFF00FF00;
|
||||
i += 8;
|
||||
}
|
||||
if (bits & 0xF0F0F0F0) {
|
||||
bits &= 0xF0F0F0F0;
|
||||
i += 4;
|
||||
}
|
||||
if (bits & 0xCCCCCCCC) {
|
||||
bits &= 0xCCCCCCCC;
|
||||
i += 2;
|
||||
}
|
||||
if (bits & 0xAAAAAAAA) {
|
||||
bits &= 0xAAAAAAAA;
|
||||
i += 1;
|
||||
}
|
||||
return i;
|
||||
}
|
||||
|
||||
static inline int bottom_bit(unsigned int bits)
|
||||
{
|
||||
int i;
|
||||
|
||||
if (bits == 0)
|
||||
return -1;
|
||||
i = 32;
|
||||
if (bits & 0x0000FFFF) {
|
||||
bits &= 0x0000FFFF;
|
||||
i -= 16;
|
||||
}
|
||||
if (bits & 0x00FF00FF) {
|
||||
bits &= 0x00FF00FF;
|
||||
i -= 8;
|
||||
}
|
||||
if (bits & 0x0F0F0F0F) {
|
||||
bits &= 0x0F0F0F0F;
|
||||
i -= 4;
|
||||
}
|
||||
if (bits & 0x33333333) {
|
||||
bits &= 0x33333333;
|
||||
i -= 2;
|
||||
}
|
||||
if (bits & 0x55555555) {
|
||||
bits &= 0x55555555;
|
||||
i -= 1;
|
||||
}
|
||||
return i;
|
||||
}
|
||||
#endif
|
||||
|
||||
/*! \brief Bit reverse a byte.
|
||||
\param data The byte to be reversed.
|
||||
\return The bit reversed version of data. */
|
||||
static inline uint8_t bit_reverse8(uint8_t x)
|
||||
{
|
||||
#if defined(__i386__) || defined(__x86_64__)
|
||||
/* If multiply is fast */
|
||||
return ((x * 0x0802U & 0x22110U) | (x * 0x8020U & 0x88440U)) *
|
||||
0x10101U >> 16;
|
||||
#else
|
||||
/* If multiply is slow, but we have a barrel shifter */
|
||||
x = (x >> 4) | (x << 4);
|
||||
x = ((x & 0xCC) >> 2) | ((x & 0x33) << 2);
|
||||
return ((x & 0xAA) >> 1) | ((x & 0x55) << 1);
|
||||
#endif
|
||||
}
|
||||
|
||||
/*! \brief Bit reverse a 16 bit word.
|
||||
\param data The word to be reversed.
|
||||
\return The bit reversed version of data. */
|
||||
uint16_t bit_reverse16(uint16_t data);
|
||||
|
||||
/*! \brief Bit reverse a 32 bit word.
|
||||
\param data The word to be reversed.
|
||||
\return The bit reversed version of data. */
|
||||
uint32_t bit_reverse32(uint32_t data);
|
||||
|
||||
/*! \brief Bit reverse each of the four bytes in a 32 bit word.
|
||||
\param data The word to be reversed.
|
||||
\return The bit reversed version of data. */
|
||||
uint32_t bit_reverse_4bytes(uint32_t data);
|
||||
|
||||
/*! \brief Find the number of set bits in a 32 bit word.
|
||||
\param x The word to be searched.
|
||||
\return The number of set bits. */
|
||||
int one_bits32(uint32_t x);
|
||||
|
||||
/*! \brief Create a mask as wide as the number in a 32 bit word.
|
||||
\param x The word to be searched.
|
||||
\return The mask. */
|
||||
uint32_t make_mask32(uint32_t x);
|
||||
|
||||
/*! \brief Create a mask as wide as the number in a 16 bit word.
|
||||
\param x The word to be searched.
|
||||
\return The mask. */
|
||||
uint16_t make_mask16(uint16_t x);
|
||||
|
||||
/*! \brief Find the least significant one in a word, and return a word
|
||||
with just that bit set.
|
||||
\param x The word to be searched.
|
||||
\return The word with the single set bit. */
|
||||
static inline uint32_t least_significant_one32(uint32_t x)
|
||||
{
|
||||
return x & (-(int32_t) x);
|
||||
}
|
||||
|
||||
/*! \brief Find the most significant one in a word, and return a word
|
||||
with just that bit set.
|
||||
\param x The word to be searched.
|
||||
\return The word with the single set bit. */
|
||||
static inline uint32_t most_significant_one32(uint32_t x)
|
||||
{
|
||||
#if defined(__i386__) || defined(__x86_64__)
|
||||
return 1 << top_bit(x);
|
||||
#else
|
||||
x = make_mask32(x);
|
||||
return x ^ (x >> 1);
|
||||
#endif
|
||||
}
|
||||
|
||||
/*! \brief Find the parity of a byte.
|
||||
\param x The byte to be checked.
|
||||
\return 1 for odd, or 0 for even. */
|
||||
static inline int parity8(uint8_t x)
|
||||
{
|
||||
x = (x ^ (x >> 4)) & 0x0F;
|
||||
return (0x6996 >> x) & 1;
|
||||
}
|
||||
|
||||
/*! \brief Find the parity of a 16 bit word.
|
||||
\param x The word to be checked.
|
||||
\return 1 for odd, or 0 for even. */
|
||||
static inline int parity16(uint16_t x)
|
||||
{
|
||||
x ^= (x >> 8);
|
||||
x = (x ^ (x >> 4)) & 0x0F;
|
||||
return (0x6996 >> x) & 1;
|
||||
}
|
||||
|
||||
/*! \brief Find the parity of a 32 bit word.
|
||||
\param x The word to be checked.
|
||||
\return 1 for odd, or 0 for even. */
|
||||
static inline int parity32(uint32_t x)
|
||||
{
|
||||
x ^= (x >> 16);
|
||||
x ^= (x >> 8);
|
||||
x = (x ^ (x >> 4)) & 0x0F;
|
||||
return (0x6996 >> x) & 1;
|
||||
}
|
||||
|
||||
#endif
|
||||
/*- End of file ------------------------------------------------------------*/
|
Loading…
Reference in a new issue