/*
* Word Rotation Operations
* (C) 1999-2008 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/

#ifndef BOTAN_WORD_ROTATE_H__
#define BOTAN_WORD_ROTATE_H__

#include <botan/types.h>

namespace Botan {

/**
* Bit rotation left
* @param input the input word
* @param rot the number of bits to rotate
* @return input rotated left by rot bits
*/
template<typename T> inline T rotate_left(T input, size_t rot)
   {
   return (rot == 0) ? input : static_cast<T>((input << rot) | (input >> (8*sizeof(T)-rot)));;
   }

/**
* Bit rotation right
* @param input the input word
* @param rot the number of bits to rotate
* @return input rotated right by rot bits
*/
template<typename T> inline T rotate_right(T input, size_t rot)
   {
   return (rot == 0) ? input : static_cast<T>((input >> rot) | (input << (8*sizeof(T)-rot)));
   }

}

#endif

/*
* Word Rotation Operations
* (C) 1999-2008 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/

#ifndef BOTAN_WORD_ROTATE_H__
#define BOTAN_WORD_ROTATE_H__

#include <botan/types.h>

namespace Botan {

/**
* Bit rotation left
* @param input the input word
* @param rot the number of bits to rotate
* @return input rotated left by rot bits
*/
template<typename T> inline T rotate_left(T input, size_t rot)
   {
   rot %= 8 * sizeof(T);
   return (rot == 0) ? input : static_cast<T>((input << rot) | (input >> (8*sizeof(T)-rot)));;
   }

/**
* Bit rotation right
* @param input the input word
* @param rot the number of bits to rotate
* @return input rotated right by rot bits
*/
template<typename T> inline T rotate_right(T input, size_t rot)
   {
   rot %= 8 * sizeof(T);
   return (rot == 0) ? input : static_cast<T>((input >> rot) | (input << (8*sizeof(T)-rot)));
   }

}

#endif

Allow bit rotation by more than sizeof(T)*8 bits.
Allow bit rotation by more than sizeof(T)*8 bits.

Currently these functions will happily bit shift by >= sizeof(T)*8 bits.
However, this is undefined behavior, and results in unexpected results (0)
on at least one platform I've tested.

With this update, you can expect that rotate_left<uint32_t>(1, 32)==1
and rotate_right<uint32_t>(1, 32)==1.
