89 lines
2.2 KiB
C++
89 lines
2.2 KiB
C++
/*
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* Copyright (C) OpenTX
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*
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* Based on code named
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* th9x - http://code.google.com/p/th9x
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* er9x - http://code.google.com/p/er9x
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* gruvin9x - http://code.google.com/p/gruvin9x
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*
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* This file is based on work published at http://www.coranac.com/documents/working-with-bits-and-bitfields
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*
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* License GPLv2: http://www.gnu.org/licenses/gpl-2.0.html
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#ifndef BITFIELD_H
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#define BITFIELD_H
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#include <inttypes.h>
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// A set of bitfield handling macros
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template <typename T>
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inline T bfBit(uint8_t n)
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{
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return T(1) << n;
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}
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#define BFBIT_SET(y, mask) ( y |= (mask) )
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#define BFBIT_CLEAR(y, mask) ( y &= ~(mask) )
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#define BFBIT_FLIP(y, mask) ( y ^= (mask) )
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#define BF_SINGLE_BIT_SET(y, i) BFBIT_SET(y, bfBit(i))
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//! Create a bitmask of length 'len'.
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template <typename T>
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inline T bfBitmask(uint8_t len)
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{
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return bfBit<T>(len) - 1;
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}
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//! Create a bitfield mask of length 'len' starting at bit 'start'.
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template <typename T>
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inline T bfMask(uint8_t start, uint8_t len)
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{
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return bfBitmask<T>(len) << start;
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}
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//! Prepare a bitmask for insertion or combining.
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template <typename T>
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inline T bfPrep(T x, uint8_t start, uint8_t len)
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{
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return (x & bfBitmask<T>(len)) << start;
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}
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//! Extract a bitfield of length 'len' starting at bit 'start' from 'y'.
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template <typename T>
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inline T bfGet(T y, uint8_t start, uint8_t len)
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{
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return ((y)>>(start)) & bfBitmask<T>(len);
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}
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//! Insert 'len' bits of 'x 'into 'y', starting at bit 'start' from 'y'.
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template <class T>
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inline T bfSet(T to, T from, uint8_t start, uint8_t len)
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{
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return (to & ~bfMask<T>(start, len)) | bfPrep<T>(from, start, len);
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}
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template <class T>
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inline T bfBitGet(T y, T mask)
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{
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return (y & mask);
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}
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template <class T>
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inline T bfSingleBitGet(T y, uint8_t i)
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{
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return bfBitGet(y, bfBit<T>(i));
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}
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#endif //BITFIELD_H
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