diff options
Diffstat (limited to 'drivers/staging/echo')
| -rw-r--r-- | drivers/staging/echo/bit_operations.h | 226 |
1 files changed, 0 insertions, 226 deletions
diff --git a/drivers/staging/echo/bit_operations.h b/drivers/staging/echo/bit_operations.h deleted file mode 100644 index 4c4ccbc97313..000000000000 --- a/drivers/staging/echo/bit_operations.h +++ /dev/null @@ -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 ------------------------------------------------------------*/ |