text: #ifndef CRYPTOPP_WORDS_H
  #define CRYPTOPP_WORDS_H
  
  #include "misc.h"
  
  NAMESPACE_BEGIN(CryptoPP)
  
  inline unsigned int CountWords(const word *X, unsigned int N)
  {
  	while (N && X[N-1]==0)
  		N--;
  	return N;
  }
  
  inline void SetWords(word *r, word a, unsigned int n)
  {
  	for (unsigned int i=0; i<n; i++)
  		r[i] = a;
  }
  
  inline void CopyWords(word *r, const word *a, unsigned int n)
  {
  	for (unsigned int i=0; i<n; i++)
  		r[i] = a[i];
  }
  
  inline void XorWords(word *r, const word *a, const word *b, unsigned int n)
  {
  	for (unsigned int i=0; i<n; i++)
  		r[i] = a[i] ^ b[i];
  }
  
  inline void XorWords(word *r, const word *a, unsigned int n)
  {
  	for (unsigned int i=0; i<n; i++)
  		r[i] ^= a[i];
  }
  
  inline void AndWords(word *r, const word *a, const word *b, unsigned int n)
  {
  	for (unsigned int i=0; i<n; i++)
  		r[i] = a[i] & b[i];
  }
  
  inline void AndWords(word *r, const word *a, unsigned int n)
  {
  	for (unsigned int i=0; i<n; i++)
  		r[i] &= a[i];
  }
  
  inline word ShiftWordsLeftByBits(word *r, unsigned int n, unsigned int shiftBits)
  {
  	assert (shiftBits<WORD_BITS);
  	word u, carry=0;
  	if (shiftBits)
  		for (unsigned int i=0; i<n; i++)
  		{
  			u = r[i];
  			r[i] = (u << shiftBits) | carry;
  			carry = u >> (WORD_BITS-shiftBits);
  		}
  	return carry;
  }
  
  inline word ShiftWordsRightByBits(word *r, unsigned int n, unsigned int shiftBits)
  {
  	assert (shiftBits<WORD_BITS);
  	word u, carry=0;
  	if (shiftBits)
  		for (int i=n-1; i>=0; i--)
  		{
  			u = r[i];
  			r[i] = (u >> shiftBits) | carry;
  			carry = u << (WORD_BITS-shiftBits);
  		}
  	return carry;
  }
  
  inline void ShiftWordsLeftByWords(word *r, unsigned int n, unsigned int shiftWords)
  {
  	if (n && shiftWords)
  	{
  		for (unsigned i=n-1; i>=shiftWords; i--)
  			r[i] = r[i-shiftWords];
  		SetWords(r, 0, STDMIN(n, shiftWords));
  	}
  }
  
  inline void ShiftWordsRightByWords(word *r, unsigned int n, unsigned int shiftWords)
  {
  	if (n && shiftWords)
  	{
  		for (unsigned i=0; i<n-shiftWords; i++)
  			r[i] = r[i+shiftWords];
  		SetWords(r+n-shiftWords, 0, STDMIN(n, shiftWords));
  	}
  }
  
  NAMESPACE_END
  
  #endif
  