//
// Filename: fibo.nac
// Purpose : N-address code (NAC) implementation for the iterative version of 
//           Fibonacci series computation.
// Author  : Nikolaos Kavvadias (C) 2009, 2010
// Date    : 17-Sep-2009
// Revision: 0.2.0 (17/09/09)
//           Initial version.
// 

//constant u32 0, 1, 2;

procedure fibo(in u32 n, out u32 outp)
{
  localvar u32 res, x;
  localvar u32 f0, f1, f, k;
  
LL0:
  x <= mov n;
  f0 <= ldc 0;
  f1 <= ldc 1;
  res <= mov f0;
  S_EXIT, LL1 <= jmple x, 0;

LL1:
  res <= mov f1;
  S_EXIT, LL2 <= jmpeq x, 1;
  
LL2:
  k <= ldc 2;
  LL3 <= jmpun;
  
LL3:
  f <= add f1, f0;
  f0 <= mov f1;
  f1 <= mov f;
  res <= mov f;
  k <= add k, 1;
  LL3, S_EXIT <= jmple k, x;
  
S_EXIT:
  outp <= mov res;
}