boolbv_bswap.cpp

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/*******************************************************************\
 
Module: Bit-blasting of bswap
 
Author: Michael Tautschnig
 
\*******************************************************************/
 
#include "boolbv.h"
 
#include <util/bitvector_expr.h>
 
bvt boolbvt::convert_bswap(const bswap_exprt &expr)
{
  const std::size_t width = boolbv_width(expr.type());
 
  // width must be multiple of bytes
  const std::size_t byte_bits = expr.get_bits_per_byte();
  if(width % byte_bits != 0)
    return conversion_failed(expr);
 
  bvt result = convert_bv(expr.op(), width);
 
  std::size_t dest_base = width;
 
  for(std::size_t src = 0; src < width; ++src)
  {
    std::size_t bit_offset = src % byte_bits;
    if(bit_offset == 0)
      dest_base -= byte_bits;
 
    if(src >= dest_base)
      break;
 
    result[src].swap(result[dest_base + bit_offset]);
  }
 
  return result;
}