boolbv_concatenation.cpp

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/*******************************************************************\
 
Module:
 
Author: Daniel Kroening, kroening@kroening.com
 
\*******************************************************************/
 
#include "boolbv.h"
 
#include <util/bitvector_expr.h>
#include <util/invariant.h>
 
bvt boolbvt::convert_concatenation(const concatenation_exprt &expr)
{
  std::size_t width=boolbv_width(expr.type());
 
  const exprt::operandst &operands=expr.operands();
 
  DATA_INVARIANT(
    !operands.empty(), "concatentation shall have at least one operand");
 
  std::size_t offset=width;
  bvt bv;
  bv.resize(width);
 
  for(const auto &operand : operands)
  {
    const bvt &op = convert_bv(operand);
 
    INVARIANT(
      op.size() <= offset,
      "concatentation operand must fit into the result bitvector");
 
    offset-=op.size();
 
    for(std::size_t i=0; i<op.size(); i++)
      bv[offset+i]=op[i];
  }
 
  INVARIANT(
    offset == 0,
    "all bits in the result bitvector must have been filled up by the "
    "concatentation operands");
 
  return bv;
}