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


 #include <prdfBitString.H>

 #include <prdfAssert.h>

 #include <algorithm>

 namespace libhei
 {

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

 const uint32_t BitString::CPU_WORD_BIT_LEN = sizeof(CPU_WORD) * 8;

 const CPU_WORD BitString::CPU_WORD_MASK = static_cast<CPU_WORD>(-1);

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

 CPU_WORD BitString::getField( uint32_t i_pos, uint32_t i_len ) const
 {
     PRDF_ASSERT( nullptr != getBufAddr() );      // must to have a valid address
     PRDF_ASSERT( 0 < i_len );                    // must have at least one bit
     PRDF_ASSERT( i_len <= CPU_WORD_BIT_LEN );    // i_len length must be valid
     PRDF_ASSERT( i_pos + i_len <= getBitLen() ); // field must be within range

     // The returned value.
     CPU_WORD o_val = 0;

     // Get the relative address and position of the field.
     uint32_t relPos = 0;
     CPU_WORD * relAddr = getRelativePosition( relPos, i_pos );

     // The return value may cross two CPU_WORD addresses. Get length of each
     // chunk, mask to clear the right-handed bits, and the shift value to make
     // each chunk left-justified.
     uint32_t len0 = i_len, len1 = 0;
     if ( CPU_WORD_BIT_LEN < relPos + i_len )
     {
         len0 = CPU_WORD_BIT_LEN - relPos;
         len1 = i_len - len0;
     }

     CPU_WORD mask0 = CPU_WORD_MASK << (CPU_WORD_BIT_LEN - len0);
     CPU_WORD mask1 = CPU_WORD_MASK << (CPU_WORD_BIT_LEN - len1);

     uint32_t shift0 = relPos;
     uint32_t shift1 = CPU_WORD_BIT_LEN - relPos;

     // Get first half of the value.
     o_val = (*relAddr << shift0) & mask0;

     // Get the second half of the value, if needed
     if ( CPU_WORD_BIT_LEN < relPos + i_len )
     {
         ++relAddr;
         o_val |= (*relAddr & mask1) >> shift1;
     }

     return o_val;
 }

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

 void BitString::setField( uint32_t i_pos, uint32_t i_len, CPU_WORD i_val )
 {
     PRDF_ASSERT( nullptr != getBufAddr() );      // must to have a valid address
     PRDF_ASSERT( 0 < i_len );                    // must have at least one bit
     PRDF_ASSERT( i_len <= CPU_WORD_BIT_LEN );    // i_len length must be valid
     PRDF_ASSERT( i_pos + i_len <= getBitLen() ); // field must be within range

     // Get the relative address and position of the field.
     uint32_t relPos = 0;
     CPU_WORD * relAddr = getRelativePosition( relPos, i_pos );

     // The value is left-justified. Ignore all other bits.
     CPU_WORD mask = CPU_WORD_MASK << (CPU_WORD_BIT_LEN - i_len);
     CPU_WORD val  = i_val & mask;

     // Set first half of the value.
     *relAddr &= ~(mask >> relPos); // Clear field
     *relAddr |=  (val  >> relPos); // Set field

     // Get the second half of the value, if needed
     if ( CPU_WORD_BIT_LEN < relPos + i_len )
     {
         relAddr++;
         *relAddr &= ~(mask << (CPU_WORD_BIT_LEN - relPos)); // Clear field
         *relAddr |=  (val  << (CPU_WORD_BIT_LEN - relPos)); // Set field
     }
 }

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

 void BitString::setPattern( uint32_t i_sPos, uint32_t i_sLen,
                             CPU_WORD i_pattern, uint32_t i_pLen )
 {
     PRDF_ASSERT(nullptr != getBufAddr());        // must to have a valid address
     PRDF_ASSERT(0 < i_sLen);                     // must have at least one bit
     PRDF_ASSERT(i_sPos + i_sLen <= getBitLen()); // field must be within range
     PRDF_ASSERT(0 < i_pLen);                     // must have at least one bit
     PRDF_ASSERT(i_pLen <= CPU_WORD_BIT_LEN);     // i_pLen length must be valid

     // Get a bit string for the pattern subset (right justified).
     BitString bso ( i_pLen, &i_pattern, CPU_WORD_BIT_LEN - i_pLen );

     // Iterate the range in chunks the size of i_pLen.
     uint32_t endPos = i_sPos + i_sLen;
     for ( uint32_t pos = i_sPos; pos < endPos; pos += i_pLen )
     {
         // The true chunk size is either i_pLen or the leftovers at the end.
         uint32_t len = std::min( i_pLen, endPos - pos );

         // Get this chunk's pattern value, truncate (left justified) if needed.
         CPU_WORD pattern = bso.getField( 0, len );

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

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

 void BitString::setString( const BitString & i_sStr, uint32_t i_sPos,
                            uint32_t i_sLen, uint32_t i_dPos )
 {
     // Ensure the source parameters are valid.
     PRDF_ASSERT( nullptr != i_sStr.getBufAddr() );
     PRDF_ASSERT( 0 < i_sLen ); // at least one bit to copy
     PRDF_ASSERT( i_sPos + i_sLen <= i_sStr.getBitLen() );

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

     // If the source length is greater than the destination length than the
     // extra source bits are ignored.
     uint32_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.
     uint32_t sRelOffset = 0, dRelOffset = 0;
     CPU_WORD * sRelAddr = i_sStr.getRelativePosition( sRelOffset, i_sPos );
     CPU_WORD * 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 ( uint32_t pos = 0; pos < actLen; pos += CPU_WORD_BIT_LEN )
         {
             uint32_t len = std::min( actLen - pos, CPU_WORD_BIT_LEN );

             CPU_WORD value = i_sStr.getField( i_sPos + pos, len );
             setField( i_dPos + pos, len, value );
         }
     }
     else // Copy the data backwards.
     {
         // Get the first position of the last chunk (CPU_WORD aligned).
         uint32_t lastPos = ((actLen-1) / CPU_WORD_BIT_LEN) * CPU_WORD_BIT_LEN;

         // Start with the last chunk and work backwards.
         for ( int32_t pos = lastPos; 0 <= pos; pos -= CPU_WORD_BIT_LEN )
         {
             uint32_t len = std::min( actLen - pos, CPU_WORD_BIT_LEN );

             CPU_WORD value = i_sStr.getField( i_sPos + pos, len );
             setField( i_dPos + pos, len, value );
         }
     }
 }

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

 void BitString::maskString( const BitString & i_mask )
 {
     // Get the length of the smallest string.
     uint32_t actLen = std::min( getBitLen(), i_mask.getBitLen() );

     for ( uint32_t pos = 0; pos < actLen; pos += CPU_WORD_BIT_LEN )
     {
         uint32_t len = std::min( actLen - pos, CPU_WORD_BIT_LEN );

         CPU_WORD dVal =        getField( pos, len );
         CPU_WORD sVal = i_mask.getField( pos, len );

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

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

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

     for ( uint32_t pos = 0; pos < getBitLen(); pos += CPU_WORD_BIT_LEN )
     {
         uint32_t len = std::min( getBitLen() - pos, CPU_WORD_BIT_LEN );

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

     return true; // bit strings match
 }

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

 bool BitString::isZero() const
 {
     for ( uint32_t pos = 0; pos < getBitLen(); pos += CPU_WORD_BIT_LEN )
     {
         uint32_t len = std::min( getBitLen() - pos, CPU_WORD_BIT_LEN );

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

     return true; // everything was zero
 }

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

 uint32_t BitString::getSetCount( uint32_t i_pos, uint32_t i_len ) const
 {
     uint32_t endPos = i_pos + i_len;

     PRDF_ASSERT( endPos <= getBitLen() );

     uint32_t count = 0;

     for ( uint32_t i = i_pos; i < endPos; i++ )
     {
         if ( isBitSet(i) ) count++;
     }

     return count;
 }

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

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

     for ( uint32_t pos = 0; pos < getBitLen(); pos += CPU_WORD_BIT_LEN )
     {
         uint32_t len = std::min( getBitLen() - pos, CPU_WORD_BIT_LEN );

         CPU_WORD dVal = getField( pos, len );

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

     return bsb;
 }

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

 BitStringBuffer BitString::operator&( const BitString & i_bs ) const
 {
     // Get the length of the smallest string.
     uint32_t actLen = std::min( getBitLen(), i_bs.getBitLen() );

     BitStringBuffer bsb( actLen );

     for ( uint32_t pos = 0; pos < actLen; pos += CPU_WORD_BIT_LEN )
     {
         uint32_t len = std::min( actLen - pos, CPU_WORD_BIT_LEN );

         CPU_WORD dVal =      getField( pos, len );
         CPU_WORD sVal = i_bs.getField( pos, len );

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

     return bsb;
 }

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

 BitStringBuffer BitString::operator|( const BitString & i_bs ) const
 {
     // Get the length of the smallest string.
     uint32_t actLen = std::min( getBitLen(), i_bs.getBitLen() );

     BitStringBuffer bsb( actLen );

     for ( uint32_t pos = 0; pos < actLen; pos += CPU_WORD_BIT_LEN )
     {
         uint32_t len = std::min( actLen - pos, CPU_WORD_BIT_LEN );

         CPU_WORD dVal =      getField( pos, len );
         CPU_WORD sVal = i_bs.getField( pos, len );

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

     return bsb;
 }

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

 BitStringBuffer BitString::operator>>( uint32_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<<( uint32_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;
 }

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

 CPU_WORD * BitString::getRelativePosition( uint32_t & o_relPos,
                                            uint32_t   i_absPos ) const
 {
     PRDF_ASSERT( nullptr != getBufAddr() ); // must to have a valid address
     PRDF_ASSERT( i_absPos < getBitLen() );  // must be a valid position

     o_relPos = (i_absPos + iv_offset) % CPU_WORD_BIT_LEN;

     return iv_bufAddr + ((i_absPos + iv_offset) / CPU_WORD_BIT_LEN);
 }

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

 BitStringBuffer::BitStringBuffer( uint32_t i_bitLen ) :
     BitString( i_bitLen, nullptr )
 {
     initBuffer();
 }

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

 BitStringBuffer::~BitStringBuffer()
 {
     delete [] 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 [] 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 [] 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 [] getBufAddr();

     // Allocate the new buffer.
     setBufAddr( new CPU_WORD[ getNumCpuWords(getBitLen()) ] );

     // Clear the new buffer.
     if ( !isZero() ) clearAll();
 }

 } // end namespace libhei

	#include <prdfBitString.H>

	#include <prdfAssert.h>

	#include <algorithm>

	namespace libhei
	{

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

	const uint32_t BitString::CPU_WORD_BIT_LEN = sizeof(CPU_WORD) * 8;

	const CPU_WORD BitString::CPU_WORD_MASK = static_cast<CPU_WORD>(-1);

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

	CPU_WORD BitString::getField( uint32_t i_pos, uint32_t i_len ) const
	{
	PRDF_ASSERT( nullptr != getBufAddr() ); // must to have a valid address
	PRDF_ASSERT( 0 < i_len ); // must have at least one bit
	PRDF_ASSERT( i_len <= CPU_WORD_BIT_LEN ); // i_len length must be valid
	PRDF_ASSERT( i_pos + i_len <= getBitLen() ); // field must be within range

	// The returned value.
	CPU_WORD o_val = 0;

	// Get the relative address and position of the field.
	uint32_t relPos = 0;
	CPU_WORD * relAddr = getRelativePosition( relPos, i_pos );

	// The return value may cross two CPU_WORD addresses. Get length of each
	// chunk, mask to clear the right-handed bits, and the shift value to make
	// each chunk left-justified.
	uint32_t len0 = i_len, len1 = 0;
	if ( CPU_WORD_BIT_LEN < relPos + i_len )
	{
	len0 = CPU_WORD_BIT_LEN - relPos;
	len1 = i_len - len0;
	}

	CPU_WORD mask0 = CPU_WORD_MASK << (CPU_WORD_BIT_LEN - len0);
	CPU_WORD mask1 = CPU_WORD_MASK << (CPU_WORD_BIT_LEN - len1);

	uint32_t shift0 = relPos;
	uint32_t shift1 = CPU_WORD_BIT_LEN - relPos;

	// Get first half of the value.
	o_val = (*relAddr << shift0) & mask0;

	// Get the second half of the value, if needed
	if ( CPU_WORD_BIT_LEN < relPos + i_len )
	{
	++relAddr;
	o_val \|= (*relAddr & mask1) >> shift1;
	}

	return o_val;
	}

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

	void BitString::setField( uint32_t i_pos, uint32_t i_len, CPU_WORD i_val )
	{
	PRDF_ASSERT( nullptr != getBufAddr() ); // must to have a valid address
	PRDF_ASSERT( 0 < i_len ); // must have at least one bit
	PRDF_ASSERT( i_len <= CPU_WORD_BIT_LEN ); // i_len length must be valid
	PRDF_ASSERT( i_pos + i_len <= getBitLen() ); // field must be within range

	// Get the relative address and position of the field.
	uint32_t relPos = 0;
	CPU_WORD * relAddr = getRelativePosition( relPos, i_pos );

	// The value is left-justified. Ignore all other bits.
	CPU_WORD mask = CPU_WORD_MASK << (CPU_WORD_BIT_LEN - i_len);
	CPU_WORD val = i_val & mask;

	// Set first half of the value.
	*relAddr &= ~(mask >> relPos); // Clear field
	*relAddr \|= (val >> relPos); // Set field

	// Get the second half of the value, if needed
	if ( CPU_WORD_BIT_LEN < relPos + i_len )
	{
	relAddr++;
	*relAddr &= ~(mask << (CPU_WORD_BIT_LEN - relPos)); // Clear field
	*relAddr \|= (val << (CPU_WORD_BIT_LEN - relPos)); // Set field
	}
	}

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

	void BitString::setPattern( uint32_t i_sPos, uint32_t i_sLen,
	CPU_WORD i_pattern, uint32_t i_pLen )
	{
	PRDF_ASSERT(nullptr != getBufAddr()); // must to have a valid address
	PRDF_ASSERT(0 < i_sLen); // must have at least one bit
	PRDF_ASSERT(i_sPos + i_sLen <= getBitLen()); // field must be within range
	PRDF_ASSERT(0 < i_pLen); // must have at least one bit
	PRDF_ASSERT(i_pLen <= CPU_WORD_BIT_LEN); // i_pLen length must be valid

	// Get a bit string for the pattern subset (right justified).
	BitString bso ( i_pLen, &i_pattern, CPU_WORD_BIT_LEN - i_pLen );

	// Iterate the range in chunks the size of i_pLen.
	uint32_t endPos = i_sPos + i_sLen;
	for ( uint32_t pos = i_sPos; pos < endPos; pos += i_pLen )
	{
	// The true chunk size is either i_pLen or the leftovers at the end.
	uint32_t len = std::min( i_pLen, endPos - pos );

	// Get this chunk's pattern value, truncate (left justified) if needed.
	CPU_WORD pattern = bso.getField( 0, len );

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

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

	void BitString::setString( const BitString & i_sStr, uint32_t i_sPos,
	uint32_t i_sLen, uint32_t i_dPos )
	{
	// Ensure the source parameters are valid.
	PRDF_ASSERT( nullptr != i_sStr.getBufAddr() );
	PRDF_ASSERT( 0 < i_sLen ); // at least one bit to copy
	PRDF_ASSERT( i_sPos + i_sLen <= i_sStr.getBitLen() );

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

	// If the source length is greater than the destination length than the
	// extra source bits are ignored.
	uint32_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.
	uint32_t sRelOffset = 0, dRelOffset = 0;
	CPU_WORD * sRelAddr = i_sStr.getRelativePosition( sRelOffset, i_sPos );
	CPU_WORD * 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 ( uint32_t pos = 0; pos < actLen; pos += CPU_WORD_BIT_LEN )
	{
	uint32_t len = std::min( actLen - pos, CPU_WORD_BIT_LEN );

	CPU_WORD value = i_sStr.getField( i_sPos + pos, len );
	setField( i_dPos + pos, len, value );
	}
	}
	else // Copy the data backwards.
	{
	// Get the first position of the last chunk (CPU_WORD aligned).
	uint32_t lastPos = ((actLen-1) / CPU_WORD_BIT_LEN) * CPU_WORD_BIT_LEN;

	// Start with the last chunk and work backwards.
	for ( int32_t pos = lastPos; 0 <= pos; pos -= CPU_WORD_BIT_LEN )
	{
	uint32_t len = std::min( actLen - pos, CPU_WORD_BIT_LEN );

	CPU_WORD value = i_sStr.getField( i_sPos + pos, len );
	setField( i_dPos + pos, len, value );
	}
	}
	}

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

	void BitString::maskString( const BitString & i_mask )
	{
	// Get the length of the smallest string.
	uint32_t actLen = std::min( getBitLen(), i_mask.getBitLen() );

	for ( uint32_t pos = 0; pos < actLen; pos += CPU_WORD_BIT_LEN )
	{
	uint32_t len = std::min( actLen - pos, CPU_WORD_BIT_LEN );

	CPU_WORD dVal = getField( pos, len );
	CPU_WORD sVal = i_mask.getField( pos, len );

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

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

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

	for ( uint32_t pos = 0; pos < getBitLen(); pos += CPU_WORD_BIT_LEN )
	{
	uint32_t len = std::min( getBitLen() - pos, CPU_WORD_BIT_LEN );

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

	return true; // bit strings match
	}

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

	bool BitString::isZero() const
	{
	for ( uint32_t pos = 0; pos < getBitLen(); pos += CPU_WORD_BIT_LEN )
	{
	uint32_t len = std::min( getBitLen() - pos, CPU_WORD_BIT_LEN );

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

	return true; // everything was zero
	}

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

	uint32_t BitString::getSetCount( uint32_t i_pos, uint32_t i_len ) const
	{
	uint32_t endPos = i_pos + i_len;

	PRDF_ASSERT( endPos <= getBitLen() );

	uint32_t count = 0;

	for ( uint32_t i = i_pos; i < endPos; i++ )
	{
	if ( isBitSet(i) ) count++;
	}

	return count;
	}

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

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

	for ( uint32_t pos = 0; pos < getBitLen(); pos += CPU_WORD_BIT_LEN )
	{
	uint32_t len = std::min( getBitLen() - pos, CPU_WORD_BIT_LEN );

	CPU_WORD dVal = getField( pos, len );

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

	return bsb;
	}

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

	BitStringBuffer BitString::operator&( const BitString & i_bs ) const
	{
	// Get the length of the smallest string.
	uint32_t actLen = std::min( getBitLen(), i_bs.getBitLen() );

	BitStringBuffer bsb( actLen );

	for ( uint32_t pos = 0; pos < actLen; pos += CPU_WORD_BIT_LEN )
	{
	uint32_t len = std::min( actLen - pos, CPU_WORD_BIT_LEN );

	CPU_WORD dVal = getField( pos, len );
	CPU_WORD sVal = i_bs.getField( pos, len );

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

	return bsb;
	}

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

	BitStringBuffer BitString::operator\|( const BitString & i_bs ) const
	{
	// Get the length of the smallest string.
	uint32_t actLen = std::min( getBitLen(), i_bs.getBitLen() );

	BitStringBuffer bsb( actLen );

	for ( uint32_t pos = 0; pos < actLen; pos += CPU_WORD_BIT_LEN )
	{
	uint32_t len = std::min( actLen - pos, CPU_WORD_BIT_LEN );

	CPU_WORD dVal = getField( pos, len );
	CPU_WORD sVal = i_bs.getField( pos, len );

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

	return bsb;
	}

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

	BitStringBuffer BitString::operator>>( uint32_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<<( uint32_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;
	}

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

	CPU_WORD * BitString::getRelativePosition( uint32_t & o_relPos,
	uint32_t i_absPos ) const
	{
	PRDF_ASSERT( nullptr != getBufAddr() ); // must to have a valid address
	PRDF_ASSERT( i_absPos < getBitLen() ); // must be a valid position

	o_relPos = (i_absPos + iv_offset) % CPU_WORD_BIT_LEN;

	return iv_bufAddr + ((i_absPos + iv_offset) / CPU_WORD_BIT_LEN);
	}

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

	BitStringBuffer::BitStringBuffer( uint32_t i_bitLen ) :
	BitString( i_bitLen, nullptr )
	{
	initBuffer();
	}

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

	BitStringBuffer::~BitStringBuffer()
	{
	delete [] 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 [] 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 [] 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 [] getBufAddr();

	// Allocate the new buffer.
	setBufAddr( new CPU_WORD[ getNumCpuWords(getBitLen()) ] );

	// Clear the new buffer.
	if ( !isZero() ) clearAll();
	}

	} // end namespace libhei