src/util/hei_bit_string.cpp - openbmc/openpower-libhei - Gitiles

 /** @file hei_bit_string.cpp
  *  @brief BitString and BitStringBuffer class definitions
  */

 #include <util/hei_bit_string.hpp>

 #include <hei_user_defines.hpp>

 #include <algorithm>

 namespace libhei
 {

 //##############################################################################
 //                             BitString class
 //##############################################################################

 // number of bits in a uint64_t
 constexpr uint64_t BitString::UINT64_BIT_LEN = sizeof(uint64_t) * 8;
 // number of bits in a uint8_t
 constexpr uint64_t BitString::UINT8_BIT_LEN = sizeof(uint8_t) * 8;

 //------------------------------------------------------------------------------

 uint64_t BitString::getFieldRight( uint64_t i_pos, uint64_t i_len ) const
 {
     HEI_ASSERT( nullptr != getBufAddr() );      // must to have a valid address
     HEI_ASSERT( 0 < i_len );                    // must have at least one bit
     HEI_ASSERT( i_len <= UINT64_BIT_LEN );      // i_len length must be valid
     HEI_ASSERT( i_pos + i_len <= getBitLen() ); // field must be within range

     // Get the relative address of this byte and the relative starting position
     // within the byte.
     uint64_t relPos = 0;
     uint8_t * relAddr = getRelativePosition( relPos, i_pos );

     // Get the length of the target bit field within this byte and the length of
     // the bit field for any remaining bits.
     uint64_t bf_len     = i_len;
     uint64_t remain_len = 0;
     if ( UINT8_BIT_LEN < relPos + i_len )
     {
         // The target bit field crosses a byte boundary. So truncate the bit
         // length for this byte and update the remaining length.
         bf_len     = UINT8_BIT_LEN - relPos;
         remain_len = i_len - bf_len;
     }

     // Get the target bit field within this byte (right justified).
     uint8_t bf = *relAddr;
     bf <<= relPos;                 // Mask off uneeded bits on the left side.
     bf >>= UINT8_BIT_LEN - bf_len; // Right justify the value.

     // Check for any remaining bits after this target byte.
     if ( 0 != remain_len )
     {
         // Recursively call this function on the remaining bits and push them
         // into the right side of the return value.
         uint64_t val = static_cast<uint64_t>(bf) << remain_len;
         return val | getFieldRight( i_pos + bf_len, remain_len );
     }

     // Nothing more to do. Simply return this bit field.
     return bf;
 }

 //------------------------------------------------------------------------------

 void BitString::setFieldLeft( uint64_t i_pos, uint64_t i_len, uint64_t i_val )
 {
     HEI_ASSERT( nullptr != getBufAddr() );      // must to have a valid address
     HEI_ASSERT( 0 < i_len );                    // must have at least one bit
     HEI_ASSERT( i_len <= UINT64_BIT_LEN );      // i_len length must be valid
     HEI_ASSERT( i_pos + i_len <= getBitLen() ); // field must be within range

     // Get the relative address of this byte and the relative starting position
     // within the byte.
     uint64_t relPos = 0;
     uint8_t * relAddr = getRelativePosition( relPos, i_pos );

     // Get the length of the target bit field within this byte and the length of
     // the bit field for any remaining bits.
     uint64_t bf_len     = i_len;
     uint64_t remain_len = 0;
     if ( UINT8_BIT_LEN < relPos + i_len )
     {
         // The target bit field crosses a byte boundary. So truncate the bit
         // length for this byte and update the remaining length.
         bf_len     = UINT8_BIT_LEN - relPos;
         remain_len = i_len - bf_len;
     }

     // It is possible there are bits in this byte on either side of the target
     // bit field that must be preserved. Get the length of each of those bit
     // fields.
     uint64_t bf_l_len = relPos;
     uint64_t bf_r_len = UINT8_BIT_LEN - (bf_l_len + bf_len);

     // Get the target bit field from the left justified inputed value.
     uint8_t bf = (i_val >> (UINT64_BIT_LEN - bf_len)) << bf_r_len;

     // Get the bit fields on either side of the target bit field.
     uint64_t bf_l_shift = UINT8_BIT_LEN - bf_l_len;
     uint64_t bf_r_shift = UINT8_BIT_LEN - bf_r_len;
     uint8_t bf_l = *relAddr; bf_l >>= bf_l_shift; bf_l <<= bf_l_shift;
     uint8_t bf_r = *relAddr; bf_r <<= bf_r_shift; bf_r >>= bf_r_shift;

     // Combine all three parts of the byte and write it out to memory.
     *relAddr = bf_l | bf | bf_r;

     // Check for any remaining bits after this target byte.
     if ( 0 != remain_len )
     {
         // Recursively call this function on the remaining bits.
         setFieldLeft( i_pos + bf_len, remain_len, i_val << bf_len );
     }
 }

 //------------------------------------------------------------------------------

 void BitString::setPattern( uint64_t i_sPos, uint64_t i_sLen,
                             uint64_t i_pattern, uint64_t i_pLen )
 {

     HEI_ASSERT(nullptr != getBufAddr());        // must to have a valid address
     HEI_ASSERT(0 < i_sLen);                     // must have at least one bit
     HEI_ASSERT(i_sPos + i_sLen <= getBitLen()); // field must be within range
     HEI_ASSERT(0 < i_pLen);                     // must have at least one bit
     HEI_ASSERT(i_pLen <= UINT64_BIT_LEN);        // i_pLen length must be valid

     // Get a bit string for the pattern subset (right justified).
     // Note that we cannot use a BitStringBuffer here because this function
     // could be used in the constructor of BitStringBuffer, which could causes
     // an infinite loop.
     uint8_t a[sizeof(i_pattern)] = {};
     BitString bs { sizeof(i_pattern)*8, a };
     bs.setFieldRight(0, i_pLen, i_pattern);

     // Iterate the range in chunks the size of i_pLen.
     uint64_t endPos = i_sPos + i_sLen;
     for ( uint64_t pos = i_sPos; pos < endPos; pos += i_pLen )
     {
         // The true chunk size is either i_pLen or the leftovers at the end.
         uint64_t len = std::min( i_pLen, endPos - pos );

         // Get this chunk's pattern value, truncate (right justified) if needed.
         uint64_t pattern = bs.getFieldRight( 0, len );

         // Set the pattern in this string.
         setFieldRight( pos, len, pattern );
     }
 }

 //------------------------------------------------------------------------------

 void BitString::setString( const BitString & i_sStr, uint64_t i_sPos,
                            uint64_t i_sLen, uint64_t i_dPos )
 {
     // Ensure the source parameters are valid.
     HEI_ASSERT( nullptr != i_sStr.getBufAddr() );
     HEI_ASSERT( 0 < i_sLen ); // at least one bit to copy
     HEI_ASSERT( i_sPos + i_sLen <= i_sStr.getBitLen() );

     // Ensure the destination has at least one bit available to copy.
     HEI_ASSERT( nullptr != getBufAddr() );
     HEI_ASSERT( i_dPos < getBitLen() );

     // If the source length is greater than the destination length than the
     // extra source bits are ignored.
     uint64_t actLen = std::min( i_sLen, getBitLen() - i_dPos );

     // The bit strings may be in overlapping memory spaces. So we need to copy
     // the data in the correct direction to prevent overlapping.
     uint64_t sRelOffset = 0, dRelOffset = 0;
     uint8_t * sRelAddr = i_sStr.getRelativePosition( sRelOffset, i_sPos );
     uint8_t * dRelAddr =        getRelativePosition( dRelOffset, i_dPos );

     // Copy the data.
     if ( (dRelAddr == sRelAddr) && (dRelOffset == sRelOffset) )
     {
         // Do nothing. The source and destination are the same.
     }
     else if ( (dRelAddr < sRelAddr) ||
               ((dRelAddr == sRelAddr) && (dRelOffset < sRelOffset)) )
     {
         // Copy the data forward.
         for ( uint64_t pos = 0; pos < actLen; pos += UINT64_BIT_LEN )
         {
             uint64_t len = std::min( actLen - pos, UINT64_BIT_LEN );

             uint64_t value = i_sStr.getFieldRight( i_sPos + pos, len );
             setFieldRight( i_dPos + pos, len, value );
         }
     }
     else // Copy the data backwards.
     {
         // Get the first position of the last chunk (byte aligned).
         uint64_t lastPos = ((actLen-1) / UINT64_BIT_LEN) * UINT64_BIT_LEN;

         // Start with the last chunk and work backwards.
         for ( int32_t pos = lastPos; 0 <= pos; pos -= UINT64_BIT_LEN )
         {
             uint64_t len = std::min( actLen - pos, UINT64_BIT_LEN );
             uint64_t value = i_sStr.getFieldRight( i_sPos + pos, len );
             setFieldRight( i_dPos + pos, len, value );
         }
     }
 }

 //------------------------------------------------------------------------------

 void BitString::maskString( const BitString & i_mask )
 {
     // Get the length of the smallest string.
     uint64_t actLen = std::min( getBitLen(), i_mask.getBitLen() );

     for ( uint64_t pos = 0; pos < actLen; pos += UINT64_BIT_LEN )
     {
         uint64_t len = std::min( actLen - pos, UINT64_BIT_LEN );

         uint64_t dVal =        getFieldRight( pos, len );
         uint64_t sVal = i_mask.getFieldRight( pos, len );

         setFieldRight( pos, len, dVal & ~sVal );
     }
 }

 //------------------------------------------------------------------------------

 bool BitString::isEqual( const BitString & i_str ) const
 {
     if ( getBitLen() != i_str.getBitLen() )
         return false; // size not equal

     for ( uint64_t pos = 0; pos < getBitLen(); pos += UINT64_BIT_LEN )
     {
         uint64_t len = std::min( getBitLen() - pos, UINT64_BIT_LEN );

         if ( getFieldRight(pos, len) != i_str.getFieldRight(pos, len) )
             return false; // bit strings do not match
     }

     return true; // bit strings match
 }

 //------------------------------------------------------------------------------

 bool BitString::isZero() const
 {
     for ( uint64_t pos = 0; pos < getBitLen(); pos += UINT64_BIT_LEN )
     {
         uint64_t len = std::min( getBitLen() - pos, UINT64_BIT_LEN );

         if ( 0 != getFieldRight(pos, len) )
             return false; // something is non-zero
     }

     return true; // everything was zero
 }

 //------------------------------------------------------------------------------

 uint64_t BitString::getSetCount( uint64_t i_pos, uint64_t i_len ) const
 {
     uint64_t endPos = i_pos + i_len;

     HEI_ASSERT( endPos <= getBitLen() );

     uint64_t count = 0;

     for ( uint64_t i = i_pos; i < endPos; i++ )
     {
         if ( isBitSet(i) ) count++;
     }

     return count;
 }

 //------------------------------------------------------------------------------

 BitStringBuffer BitString::operator~() const
 {
     BitStringBuffer bsb( getBitLen() );

     for ( uint64_t pos = 0; pos < getBitLen(); pos += UINT64_BIT_LEN )
     {
         uint64_t len = std::min( getBitLen() - pos, UINT64_BIT_LEN );

         uint64_t dVal = getFieldRight( pos, len );

         bsb.setFieldRight( pos, len, ~dVal );
     }

     return bsb;
 }

 //------------------------------------------------------------------------------

 BitStringBuffer BitString::operator&( const BitString & i_bs ) const
 {
     // Get the length of the smallest string.
     uint64_t actLen = std::min( getBitLen(), i_bs.getBitLen() );

     BitStringBuffer bsb( actLen );

     for ( uint64_t pos = 0; pos < actLen; pos += UINT64_BIT_LEN )
     {
         uint64_t len = std::min( actLen - pos, UINT64_BIT_LEN );

         uint64_t dVal =      getFieldRight( pos, len );
         uint64_t sVal = i_bs.getFieldRight( pos, len );

         bsb.setFieldRight( pos, len, dVal & sVal );
     }

     return bsb;
 }

 //------------------------------------------------------------------------------

 BitStringBuffer BitString::operator|( const BitString & i_bs ) const
 {
     // Get the length of the smallest string.
     uint64_t actLen = std::min( getBitLen(), i_bs.getBitLen() );

     BitStringBuffer bsb( actLen );

     for ( uint64_t pos = 0; pos < actLen; pos += UINT64_BIT_LEN )
     {
         uint64_t len = std::min( actLen - pos, UINT64_BIT_LEN );

         uint64_t dVal =      getFieldRight( pos, len );
         uint64_t sVal = i_bs.getFieldRight( pos, len );

         bsb.setFieldRight( pos, len, dVal | sVal );
     }

     return bsb;
 }

 //------------------------------------------------------------------------------

 BitStringBuffer BitString::operator>>( uint64_t i_shift ) const
 {
     BitStringBuffer bsb( getBitLen() ); // default all zeros

     if ( i_shift < getBitLen() )
     {
         // bso overlays bsb, containing the shifted offset.
         BitString bso ( bsb.getBitLen() - i_shift, bsb.getBufAddr(), i_shift );

         // Copy this into bso.
         bso.setString( *this );
     }

     return bsb;
 }

 //------------------------------------------------------------------------------

 BitStringBuffer BitString::operator<<( uint64_t i_shift ) const
 {
     BitStringBuffer bsb( getBitLen() ); // default all zeros

     if ( i_shift < getBitLen() )
     {
         // bso overlays *this, containing the shifted offset.
         BitString bso ( this->getBitLen() - i_shift, this->getBufAddr(),
                         i_shift );

         // Copy bso into bsb.
         bsb.setString( bso );
     }

     return bsb;
 }

 //------------------------------------------------------------------------------

 uint8_t * BitString::getRelativePosition( uint64_t & o_relPos,
                                           uint64_t   i_absPos ) const
 {
     HEI_ASSERT( nullptr != getBufAddr() ); // must to have a valid address
     HEI_ASSERT( i_absPos < getBitLen() );  // must be a valid position

     o_relPos = (i_absPos + iv_offset) % UINT8_BIT_LEN;

     return ((uint8_t *)iv_bufAddr + ((i_absPos + iv_offset) / UINT8_BIT_LEN));
 }

 //##############################################################################
 //                          BitStringBuffer class
 //##############################################################################

 BitStringBuffer::BitStringBuffer( uint64_t i_bitLen ) :
     BitString( i_bitLen, nullptr )
 {
     initBuffer();
 }

 //------------------------------------------------------------------------------

 BitStringBuffer::~BitStringBuffer()
 {
     delete [] (uint8_t *)getBufAddr();
 }

 //------------------------------------------------------------------------------

 BitStringBuffer::BitStringBuffer( const BitString & i_bs ) :
     BitString( i_bs.getBitLen(), nullptr )
 {
     initBuffer();
     if ( !i_bs.isZero() ) setString( i_bs );
 }

 //------------------------------------------------------------------------------

 BitStringBuffer::BitStringBuffer( const BitStringBuffer & i_bsb ) :
     BitString( i_bsb.getBitLen(), nullptr )
 {
     initBuffer();
     if ( !i_bsb.isZero() ) setString( i_bsb );
 }

 //------------------------------------------------------------------------------

 BitStringBuffer & BitStringBuffer::operator=( const BitString & i_bs )
 {
     // The initBuffer() function will deallocate the buffer as well, however we
     // also need to deallocate the buffer here before we set the length.
     delete [] (uint8_t *)getBufAddr();
     setBufAddr( nullptr );

     setBitLen( i_bs.getBitLen() );
     initBuffer();
     if ( !i_bs.isZero() ) setString( i_bs );

     return *this;
 }

 //------------------------------------------------------------------------------

 BitStringBuffer & BitStringBuffer::operator=( const BitStringBuffer & i_bsb )
 {
     if ( this != &i_bsb ) // Check for assignment to self
     {
         // The initBuffer() function will deallocate the buffer as well, however
         // we also need to deallocate the buffer here before we set the length.
         delete [] (uint8_t *)getBufAddr();
         setBufAddr( nullptr );

         setBitLen( i_bsb.getBitLen() );
         initBuffer();
         if ( !i_bsb.isZero() ) setString( i_bsb );
     }

     return *this;
 }

 //------------------------------------------------------------------------------

 void BitStringBuffer::initBuffer()
 {
     // Deallocate the current buffer.
     delete [] (uint8_t *)getBufAddr();

     // create new buffer, initialized to 0's
     setBufAddr( new uint8_t[ getMinBytes(getBitLen()) ]() );
 }

 } // end namespace libhei
	/** @file hei_bit_string.cpp
	* @brief BitString and BitStringBuffer class definitions
	*/

	#include <util/hei_bit_string.hpp>

	#include <hei_user_defines.hpp>

	#include <algorithm>

	namespace libhei
	{

	//##############################################################################
	// BitString class
	//##############################################################################

	// number of bits in a uint64_t
	constexpr uint64_t BitString::UINT64_BIT_LEN = sizeof(uint64_t) * 8;
	// number of bits in a uint8_t
	constexpr uint64_t BitString::UINT8_BIT_LEN = sizeof(uint8_t) * 8;

	//------------------------------------------------------------------------------

	uint64_t BitString::getFieldRight( uint64_t i_pos, uint64_t i_len ) const
	{
	HEI_ASSERT( nullptr != getBufAddr() ); // must to have a valid address
	HEI_ASSERT( 0 < i_len ); // must have at least one bit
	HEI_ASSERT( i_len <= UINT64_BIT_LEN ); // i_len length must be valid
	HEI_ASSERT( i_pos + i_len <= getBitLen() ); // field must be within range

	// Get the relative address of this byte and the relative starting position
	// within the byte.
	uint64_t relPos = 0;
	uint8_t * relAddr = getRelativePosition( relPos, i_pos );

	// Get the length of the target bit field within this byte and the length of
	// the bit field for any remaining bits.
	uint64_t bf_len = i_len;
	uint64_t remain_len = 0;
	if ( UINT8_BIT_LEN < relPos + i_len )
	{
	// The target bit field crosses a byte boundary. So truncate the bit
	// length for this byte and update the remaining length.
	bf_len = UINT8_BIT_LEN - relPos;
	remain_len = i_len - bf_len;
	}

	// Get the target bit field within this byte (right justified).
	uint8_t bf = *relAddr;
	bf <<= relPos; // Mask off uneeded bits on the left side.
	bf >>= UINT8_BIT_LEN - bf_len; // Right justify the value.

	// Check for any remaining bits after this target byte.
	if ( 0 != remain_len )
	{
	// Recursively call this function on the remaining bits and push them
	// into the right side of the return value.
	uint64_t val = static_cast<uint64_t>(bf) << remain_len;
	return val \| getFieldRight( i_pos + bf_len, remain_len );
	}

	// Nothing more to do. Simply return this bit field.
	return bf;
	}

	//------------------------------------------------------------------------------

	void BitString::setFieldLeft( uint64_t i_pos, uint64_t i_len, uint64_t i_val )
	{
	HEI_ASSERT( nullptr != getBufAddr() ); // must to have a valid address
	HEI_ASSERT( 0 < i_len ); // must have at least one bit
	HEI_ASSERT( i_len <= UINT64_BIT_LEN ); // i_len length must be valid
	HEI_ASSERT( i_pos + i_len <= getBitLen() ); // field must be within range

	// Get the relative address of this byte and the relative starting position
	// within the byte.
	uint64_t relPos = 0;
	uint8_t * relAddr = getRelativePosition( relPos, i_pos );

	// Get the length of the target bit field within this byte and the length of
	// the bit field for any remaining bits.
	uint64_t bf_len = i_len;
	uint64_t remain_len = 0;
	if ( UINT8_BIT_LEN < relPos + i_len )
	{
	// The target bit field crosses a byte boundary. So truncate the bit
	// length for this byte and update the remaining length.
	bf_len = UINT8_BIT_LEN - relPos;
	remain_len = i_len - bf_len;
	}

	// It is possible there are bits in this byte on either side of the target
	// bit field that must be preserved. Get the length of each of those bit
	// fields.
	uint64_t bf_l_len = relPos;
	uint64_t bf_r_len = UINT8_BIT_LEN - (bf_l_len + bf_len);

	// Get the target bit field from the left justified inputed value.
	uint8_t bf = (i_val >> (UINT64_BIT_LEN - bf_len)) << bf_r_len;

	// Get the bit fields on either side of the target bit field.
	uint64_t bf_l_shift = UINT8_BIT_LEN - bf_l_len;
	uint64_t bf_r_shift = UINT8_BIT_LEN - bf_r_len;
	uint8_t bf_l = *relAddr; bf_l >>= bf_l_shift; bf_l <<= bf_l_shift;
	uint8_t bf_r = *relAddr; bf_r <<= bf_r_shift; bf_r >>= bf_r_shift;

	// Combine all three parts of the byte and write it out to memory.
	*relAddr = bf_l \| bf \| bf_r;

	// Check for any remaining bits after this target byte.
	if ( 0 != remain_len )
	{
	// Recursively call this function on the remaining bits.
	setFieldLeft( i_pos + bf_len, remain_len, i_val << bf_len );
	}
	}

	//------------------------------------------------------------------------------

	void BitString::setPattern( uint64_t i_sPos, uint64_t i_sLen,
	uint64_t i_pattern, uint64_t i_pLen )
	{

	HEI_ASSERT(nullptr != getBufAddr()); // must to have a valid address
	HEI_ASSERT(0 < i_sLen); // must have at least one bit
	HEI_ASSERT(i_sPos + i_sLen <= getBitLen()); // field must be within range
	HEI_ASSERT(0 < i_pLen); // must have at least one bit
	HEI_ASSERT(i_pLen <= UINT64_BIT_LEN); // i_pLen length must be valid

	// Get a bit string for the pattern subset (right justified).
	// Note that we cannot use a BitStringBuffer here because this function
	// could be used in the constructor of BitStringBuffer, which could causes
	// an infinite loop.
	uint8_t a[sizeof(i_pattern)] = {};
	BitString bs { sizeof(i_pattern)*8, a };
	bs.setFieldRight(0, i_pLen, i_pattern);

	// Iterate the range in chunks the size of i_pLen.
	uint64_t endPos = i_sPos + i_sLen;
	for ( uint64_t pos = i_sPos; pos < endPos; pos += i_pLen )
	{
	// The true chunk size is either i_pLen or the leftovers at the end.
	uint64_t len = std::min( i_pLen, endPos - pos );

	// Get this chunk's pattern value, truncate (right justified) if needed.
	uint64_t pattern = bs.getFieldRight( 0, len );

	// Set the pattern in this string.
	setFieldRight( pos, len, pattern );
	}
	}

	//------------------------------------------------------------------------------

	void BitString::setString( const BitString & i_sStr, uint64_t i_sPos,
	uint64_t i_sLen, uint64_t i_dPos )
	{
	// Ensure the source parameters are valid.
	HEI_ASSERT( nullptr != i_sStr.getBufAddr() );
	HEI_ASSERT( 0 < i_sLen ); // at least one bit to copy
	HEI_ASSERT( i_sPos + i_sLen <= i_sStr.getBitLen() );

	// Ensure the destination has at least one bit available to copy.
	HEI_ASSERT( nullptr != getBufAddr() );
	HEI_ASSERT( i_dPos < getBitLen() );

	// If the source length is greater than the destination length than the
	// extra source bits are ignored.
	uint64_t actLen = std::min( i_sLen, getBitLen() - i_dPos );

	// The bit strings may be in overlapping memory spaces. So we need to copy
	// the data in the correct direction to prevent overlapping.
	uint64_t sRelOffset = 0, dRelOffset = 0;
	uint8_t * sRelAddr = i_sStr.getRelativePosition( sRelOffset, i_sPos );
	uint8_t * dRelAddr = getRelativePosition( dRelOffset, i_dPos );

	// Copy the data.
	if ( (dRelAddr == sRelAddr) && (dRelOffset == sRelOffset) )
	{
	// Do nothing. The source and destination are the same.
	}
	else if ( (dRelAddr < sRelAddr) \|\|
	((dRelAddr == sRelAddr) && (dRelOffset < sRelOffset)) )
	{
	// Copy the data forward.
	for ( uint64_t pos = 0; pos < actLen; pos += UINT64_BIT_LEN )
	{
	uint64_t len = std::min( actLen - pos, UINT64_BIT_LEN );

	uint64_t value = i_sStr.getFieldRight( i_sPos + pos, len );
	setFieldRight( i_dPos + pos, len, value );
	}
	}
	else // Copy the data backwards.
	{
	// Get the first position of the last chunk (byte aligned).
	uint64_t lastPos = ((actLen-1) / UINT64_BIT_LEN) * UINT64_BIT_LEN;

	// Start with the last chunk and work backwards.
	for ( int32_t pos = lastPos; 0 <= pos; pos -= UINT64_BIT_LEN )
	{
	uint64_t len = std::min( actLen - pos, UINT64_BIT_LEN );
	uint64_t value = i_sStr.getFieldRight( i_sPos + pos, len );
	setFieldRight( i_dPos + pos, len, value );
	}
	}
	}

	//------------------------------------------------------------------------------

	void BitString::maskString( const BitString & i_mask )
	{
	// Get the length of the smallest string.
	uint64_t actLen = std::min( getBitLen(), i_mask.getBitLen() );

	for ( uint64_t pos = 0; pos < actLen; pos += UINT64_BIT_LEN )
	{
	uint64_t len = std::min( actLen - pos, UINT64_BIT_LEN );

	uint64_t dVal = getFieldRight( pos, len );
	uint64_t sVal = i_mask.getFieldRight( pos, len );

	setFieldRight( pos, len, dVal & ~sVal );
	}
	}

	//------------------------------------------------------------------------------

	bool BitString::isEqual( const BitString & i_str ) const
	{
	if ( getBitLen() != i_str.getBitLen() )
	return false; // size not equal

	for ( uint64_t pos = 0; pos < getBitLen(); pos += UINT64_BIT_LEN )
	{
	uint64_t len = std::min( getBitLen() - pos, UINT64_BIT_LEN );

	if ( getFieldRight(pos, len) != i_str.getFieldRight(pos, len) )
	return false; // bit strings do not match
	}

	return true; // bit strings match
	}

	//------------------------------------------------------------------------------

	bool BitString::isZero() const
	{
	for ( uint64_t pos = 0; pos < getBitLen(); pos += UINT64_BIT_LEN )
	{
	uint64_t len = std::min( getBitLen() - pos, UINT64_BIT_LEN );

	if ( 0 != getFieldRight(pos, len) )
	return false; // something is non-zero
	}

	return true; // everything was zero
	}

	//------------------------------------------------------------------------------

	uint64_t BitString::getSetCount( uint64_t i_pos, uint64_t i_len ) const
	{
	uint64_t endPos = i_pos + i_len;

	HEI_ASSERT( endPos <= getBitLen() );

	uint64_t count = 0;

	for ( uint64_t i = i_pos; i < endPos; i++ )
	{
	if ( isBitSet(i) ) count++;
	}

	return count;
	}

	//------------------------------------------------------------------------------

	BitStringBuffer BitString::operator~() const
	{
	BitStringBuffer bsb( getBitLen() );

	for ( uint64_t pos = 0; pos < getBitLen(); pos += UINT64_BIT_LEN )
	{
	uint64_t len = std::min( getBitLen() - pos, UINT64_BIT_LEN );

	uint64_t dVal = getFieldRight( pos, len );

	bsb.setFieldRight( pos, len, ~dVal );
	}

	return bsb;
	}

	//------------------------------------------------------------------------------

	BitStringBuffer BitString::operator&( const BitString & i_bs ) const
	{
	// Get the length of the smallest string.
	uint64_t actLen = std::min( getBitLen(), i_bs.getBitLen() );

	BitStringBuffer bsb( actLen );

	for ( uint64_t pos = 0; pos < actLen; pos += UINT64_BIT_LEN )
	{
	uint64_t len = std::min( actLen - pos, UINT64_BIT_LEN );

	uint64_t dVal = getFieldRight( pos, len );
	uint64_t sVal = i_bs.getFieldRight( pos, len );

	bsb.setFieldRight( pos, len, dVal & sVal );
	}

	return bsb;
	}

	//------------------------------------------------------------------------------

	BitStringBuffer BitString::operator\|( const BitString & i_bs ) const
	{
	// Get the length of the smallest string.
	uint64_t actLen = std::min( getBitLen(), i_bs.getBitLen() );

	BitStringBuffer bsb( actLen );

	for ( uint64_t pos = 0; pos < actLen; pos += UINT64_BIT_LEN )
	{
	uint64_t len = std::min( actLen - pos, UINT64_BIT_LEN );

	uint64_t dVal = getFieldRight( pos, len );
	uint64_t sVal = i_bs.getFieldRight( pos, len );

	bsb.setFieldRight( pos, len, dVal \| sVal );
	}

	return bsb;
	}

	//------------------------------------------------------------------------------

	BitStringBuffer BitString::operator>>( uint64_t i_shift ) const
	{
	BitStringBuffer bsb( getBitLen() ); // default all zeros

	if ( i_shift < getBitLen() )
	{
	// bso overlays bsb, containing the shifted offset.
	BitString bso ( bsb.getBitLen() - i_shift, bsb.getBufAddr(), i_shift );

	// Copy this into bso.
	bso.setString( *this );
	}

	return bsb;
	}

	//------------------------------------------------------------------------------

	BitStringBuffer BitString::operator<<( uint64_t i_shift ) const
	{
	BitStringBuffer bsb( getBitLen() ); // default all zeros

	if ( i_shift < getBitLen() )
	{
	// bso overlays *this, containing the shifted offset.
	BitString bso ( this->getBitLen() - i_shift, this->getBufAddr(),
	i_shift );

	// Copy bso into bsb.
	bsb.setString( bso );
	}

	return bsb;
	}

	//------------------------------------------------------------------------------

	uint8_t * BitString::getRelativePosition( uint64_t & o_relPos,
	uint64_t i_absPos ) const
	{
	HEI_ASSERT( nullptr != getBufAddr() ); // must to have a valid address
	HEI_ASSERT( i_absPos < getBitLen() ); // must be a valid position

	o_relPos = (i_absPos + iv_offset) % UINT8_BIT_LEN;

	return ((uint8_t *)iv_bufAddr + ((i_absPos + iv_offset) / UINT8_BIT_LEN));
	}

	//##############################################################################
	// BitStringBuffer class
	//##############################################################################

	BitStringBuffer::BitStringBuffer( uint64_t i_bitLen ) :
	BitString( i_bitLen, nullptr )
	{
	initBuffer();
	}

	//------------------------------------------------------------------------------

	BitStringBuffer::~BitStringBuffer()
	{
	delete [] (uint8_t *)getBufAddr();
	}

	//------------------------------------------------------------------------------

	BitStringBuffer::BitStringBuffer( const BitString & i_bs ) :
	BitString( i_bs.getBitLen(), nullptr )
	{
	initBuffer();
	if ( !i_bs.isZero() ) setString( i_bs );
	}

	//------------------------------------------------------------------------------

	BitStringBuffer::BitStringBuffer( const BitStringBuffer & i_bsb ) :
	BitString( i_bsb.getBitLen(), nullptr )
	{
	initBuffer();
	if ( !i_bsb.isZero() ) setString( i_bsb );
	}

	//------------------------------------------------------------------------------

	BitStringBuffer & BitStringBuffer::operator=( const BitString & i_bs )
	{
	// The initBuffer() function will deallocate the buffer as well, however we
	// also need to deallocate the buffer here before we set the length.
	delete [] (uint8_t *)getBufAddr();
	setBufAddr( nullptr );

	setBitLen( i_bs.getBitLen() );
	initBuffer();
	if ( !i_bs.isZero() ) setString( i_bs );

	return *this;
	}

	//------------------------------------------------------------------------------

	BitStringBuffer & BitStringBuffer::operator=( const BitStringBuffer & i_bsb )
	{
	if ( this != &i_bsb ) // Check for assignment to self
	{
	// The initBuffer() function will deallocate the buffer as well, however
	// we also need to deallocate the buffer here before we set the length.
	delete [] (uint8_t *)getBufAddr();
	setBufAddr( nullptr );

	setBitLen( i_bsb.getBitLen() );
	initBuffer();
	if ( !i_bsb.isZero() ) setString( i_bsb );
	}

	return *this;
	}

	//------------------------------------------------------------------------------

	void BitStringBuffer::initBuffer()
	{
	// Deallocate the current buffer.
	delete [] (uint8_t *)getBufAddr();

	// create new buffer, initialized to 0's
	setBufAddr( new uint8_t[ getMinBytes(getBitLen()) ]() );
	}

	} // end namespace libhei