C++ CHREC_VARIABLE函数代码示例

tree 
reset_evolution_in_loop (unsigned loop_num,
			 tree chrec, 
			 tree new_evol)
{
  struct loop *loop = get_loop (loop_num);

  if (POINTER_TYPE_P (chrec_type (chrec)))
    gcc_assert (sizetype == chrec_type (new_evol));
  else
    gcc_assert (chrec_type (chrec) == chrec_type (new_evol));

  if (TREE_CODE (chrec) == POLYNOMIAL_CHREC
      && flow_loop_nested_p (loop, get_chrec_loop (chrec)))
    {
      tree left = reset_evolution_in_loop (loop_num, CHREC_LEFT (chrec),
					   new_evol);
      tree right = reset_evolution_in_loop (loop_num, CHREC_RIGHT (chrec),
					    new_evol);
      return build3 (POLYNOMIAL_CHREC, TREE_TYPE (left),
		     build_int_cst (NULL_TREE, CHREC_VARIABLE (chrec)),
		     left, right);
    }

  while (TREE_CODE (chrec) == POLYNOMIAL_CHREC
	 && CHREC_VARIABLE (chrec) == loop_num)
    chrec = CHREC_LEFT (chrec);
  
  return build_polynomial_chrec (loop_num, chrec, new_evol);
}

static inline tree 
chrec_fold_poly_cst (enum tree_code code, 
		     tree type, 
		     tree poly, 
		     tree cst)
{
  gcc_assert (poly);
  gcc_assert (cst);
  gcc_assert (TREE_CODE (poly) == POLYNOMIAL_CHREC);
  gcc_assert (!is_not_constant_evolution (cst));
  
  switch (code)
    {
    case PLUS_EXPR:
      return build_polynomial_chrec 
	(CHREC_VARIABLE (poly), 
	 chrec_fold_plus (type, CHREC_LEFT (poly), cst),
	 CHREC_RIGHT (poly));
      
    case MINUS_EXPR:
      return build_polynomial_chrec 
	(CHREC_VARIABLE (poly), 
	 chrec_fold_minus (type, CHREC_LEFT (poly), cst),
	 CHREC_RIGHT (poly));
      
    case MULT_EXPR:
      return build_polynomial_chrec 
	(CHREC_VARIABLE (poly), 
	 chrec_fold_multiply (type, CHREC_LEFT (poly), cst),
	 chrec_fold_multiply (type, CHREC_RIGHT (poly), cst));
      
    default:
      return chrec_dont_know;
    }
}

bool
eq_evolutions_p (const_tree chrec0, const_tree chrec1)
{
  if (chrec0 == NULL_TREE
      || chrec1 == NULL_TREE
      || TREE_CODE (chrec0) != TREE_CODE (chrec1))
    return false;

  if (chrec0 == chrec1)
    return true;

  switch (TREE_CODE (chrec0))
    {
    case INTEGER_CST:
      return operand_equal_p (chrec0, chrec1, 0);

    case POLYNOMIAL_CHREC:
      return (CHREC_VARIABLE (chrec0) == CHREC_VARIABLE (chrec1)
	      && eq_evolutions_p (CHREC_LEFT (chrec0), CHREC_LEFT (chrec1))
	      && eq_evolutions_p (CHREC_RIGHT (chrec0), CHREC_RIGHT (chrec1)));

    case PLUS_EXPR:
    case MULT_EXPR:
    case MINUS_EXPR:
    case POINTER_PLUS_EXPR:
      return eq_evolutions_p (TREE_OPERAND (chrec0, 0),
			      TREE_OPERAND (chrec1, 0))
	  && eq_evolutions_p (TREE_OPERAND (chrec0, 1),
			      TREE_OPERAND (chrec1, 1));

    default:
      return false;
    }
}

static inline tree
chrec_fold_multiply_poly_poly (tree type,
			       tree poly0,
			       tree poly1)
{
  tree t0, t1, t2;
  int var;
  struct loop *loop0 = get_chrec_loop (poly0);
  struct loop *loop1 = get_chrec_loop (poly1);

  gcc_assert (poly0);
  gcc_assert (poly1);
  gcc_assert (TREE_CODE (poly0) == POLYNOMIAL_CHREC);
  gcc_assert (TREE_CODE (poly1) == POLYNOMIAL_CHREC);
  gcc_checking_assert (useless_type_conversion_p (type, chrec_type (poly0))
		       && useless_type_conversion_p (type, chrec_type (poly1)));

  /* {a, +, b}_1 * {c, +, d}_2  ->  {c*{a, +, b}_1, +, d}_2,
     {a, +, b}_2 * {c, +, d}_1  ->  {a*{c, +, d}_1, +, b}_2,
     {a, +, b}_x * {c, +, d}_x  ->  {a*c, +, a*d + b*c + b*d, +, 2*b*d}_x.  */
  if (flow_loop_nested_p (loop0, loop1))
    /* poly0 is a constant wrt. poly1.  */
    return build_polynomial_chrec
      (CHREC_VARIABLE (poly1),
       chrec_fold_multiply (type, CHREC_LEFT (poly1), poly0),
       CHREC_RIGHT (poly1));

  if (flow_loop_nested_p (loop1, loop0))
    /* poly1 is a constant wrt. poly0.  */
    return build_polynomial_chrec
      (CHREC_VARIABLE (poly0),
       chrec_fold_multiply (type, CHREC_LEFT (poly0), poly1),
       CHREC_RIGHT (poly0));

  gcc_assert (loop0 == loop1);

  /* poly0 and poly1 are two polynomials in the same variable,
     {a, +, b}_x * {c, +, d}_x  ->  {a*c, +, a*d + b*c + b*d, +, 2*b*d}_x.  */

  /* "a*c".  */
  t0 = chrec_fold_multiply (type, CHREC_LEFT (poly0), CHREC_LEFT (poly1));

  /* "a*d + b*c".  */
  t1 = chrec_fold_multiply (type, CHREC_LEFT (poly0), CHREC_RIGHT (poly1));
  t1 = chrec_fold_plus (type, t1, chrec_fold_multiply (type,
						       CHREC_RIGHT (poly0),
						       CHREC_LEFT (poly1)));
  /* "b*d".  */
  t2 = chrec_fold_multiply (type, CHREC_RIGHT (poly0), CHREC_RIGHT (poly1));
  /* "a*d + b*c + b*d".  */
  t1 = chrec_fold_plus (type, t1, t2);
  /* "2*b*d".  */
  t2 = chrec_fold_multiply (type, SCALAR_FLOAT_TYPE_P (type)
			    ? build_real (type, dconst2)
			    : build_int_cst (type, 2), t2);

  var = CHREC_VARIABLE (poly0);
  return build_polynomial_chrec (var, t0,
				 build_polynomial_chrec (var, t1, t2));
}

static tree
chrec_component_in_loop_num (tree chrec,
			     unsigned loop_num,
			     bool right)
{
  tree component;
  struct loop *loop = get_loop (cfun, loop_num), *chloop;

  if (automatically_generated_chrec_p (chrec))
    return chrec;

  switch (TREE_CODE (chrec))
    {
    case POLYNOMIAL_CHREC:
      chloop = get_chrec_loop (chrec);

      if (chloop == loop)
	{
	  if (right)
	    component = CHREC_RIGHT (chrec);
	  else
	    component = CHREC_LEFT (chrec);

	  if (TREE_CODE (CHREC_LEFT (chrec)) != POLYNOMIAL_CHREC
	      || CHREC_VARIABLE (CHREC_LEFT (chrec)) != CHREC_VARIABLE (chrec))
	    return component;

	  else
	    return build_polynomial_chrec
	      (loop_num,
	       chrec_component_in_loop_num (CHREC_LEFT (chrec),
					    loop_num,
					    right),
	       component);
	}

      else if (flow_loop_nested_p (chloop, loop))
	/* There is no evolution part in this loop.  */
	return NULL_TREE;

      else
	{
	  gcc_assert (flow_loop_nested_p (loop, chloop));
	  return chrec_component_in_loop_num (CHREC_LEFT (chrec),
					      loop_num,
					      right);
	}

     default:
      if (right)
	return NULL_TREE;
      else
	return chrec;
    }
}

tree
chrec_fold_multiply (tree type, 
		     tree op0,
		     tree op1)
{
  if (automatically_generated_chrec_p (op0)
      || automatically_generated_chrec_p (op1))
    return chrec_fold_automatically_generated_operands (op0, op1);
  
  switch (TREE_CODE (op0))
    {
    case POLYNOMIAL_CHREC:
      switch (TREE_CODE (op1))
	{
	case POLYNOMIAL_CHREC:
	  return chrec_fold_multiply_poly_poly (type, op0, op1);
	  
	default:
	  if (integer_onep (op1))
	    return op0;
	  if (integer_zerop (op1))
	    return build_int_cst (type, 0);
	  
	  return build_polynomial_chrec 
	    (CHREC_VARIABLE (op0), 
	     chrec_fold_multiply (type, CHREC_LEFT (op0), op1),
	     chrec_fold_multiply (type, CHREC_RIGHT (op0), op1));
	}
      
    default:
      if (integer_onep (op0))
	return op1;
      
      if (integer_zerop (op0))
    	return build_int_cst (type, 0);
      
      switch (TREE_CODE (op1))
	{
	case POLYNOMIAL_CHREC:
	  return build_polynomial_chrec 
	    (CHREC_VARIABLE (op1), 
	     chrec_fold_multiply (type, CHREC_LEFT (op1), op0),
	     chrec_fold_multiply (type, CHREC_RIGHT (op1), op0));
	  
	default:
	  if (integer_onep (op1))
	    return op0;
	  if (integer_zerop (op1))
	    return build_int_cst (type, 0);
	  return fold_build2 (MULT_EXPR, type, op0, op1);
	}
    }
}

bool
is_multivariate_chrec (const_tree chrec)
{
  if (chrec == NULL_TREE)
    return false;

  if (TREE_CODE (chrec) == POLYNOMIAL_CHREC)
    return (is_multivariate_chrec_rec (CHREC_LEFT (chrec),
				       CHREC_VARIABLE (chrec))
	    || is_multivariate_chrec_rec (CHREC_RIGHT (chrec),
					  CHREC_VARIABLE (chrec)));
  else
    return false;
}

tree
chrec_convert_aggressive (tree type, tree chrec)
{
  tree inner_type, left, right, lc, rc, rtype;

  if (automatically_generated_chrec_p (chrec)
      || TREE_CODE (chrec) != POLYNOMIAL_CHREC)
    return NULL_TREE;

  inner_type = TREE_TYPE (chrec);
  if (TYPE_PRECISION (type) > TYPE_PRECISION (inner_type))
    return NULL_TREE;

  /* If we cannot perform arithmetic in TYPE, avoid creating an scev.  */
  if (avoid_arithmetics_in_type_p (type))
    return NULL_TREE;

  rtype = POINTER_TYPE_P (type) ? sizetype : type;

  left = CHREC_LEFT (chrec);
  right = CHREC_RIGHT (chrec);
  lc = chrec_convert_aggressive (type, left);
  if (!lc)
    lc = chrec_convert (type, left, NULL);
  rc = chrec_convert_aggressive (rtype, right);
  if (!rc)
    rc = chrec_convert (rtype, right, NULL);
 
  return build_polynomial_chrec (CHREC_VARIABLE (chrec), lc, rc);
}

bool
evolution_function_is_univariate_p (const_tree chrec)
{
  if (chrec == NULL_TREE)
    return true;

  switch (TREE_CODE (chrec))
    {
    case POLYNOMIAL_CHREC:
      switch (TREE_CODE (CHREC_LEFT (chrec)))
	{
	case POLYNOMIAL_CHREC:
	  if (CHREC_VARIABLE (chrec) != CHREC_VARIABLE (CHREC_LEFT (chrec)))
	    return false;
	  if (!evolution_function_is_univariate_p (CHREC_LEFT (chrec)))
	    return false;
	  break;

	default:
	  if (tree_contains_chrecs (CHREC_LEFT (chrec), NULL))
	    return false;
	  break;
	}

      switch (TREE_CODE (CHREC_RIGHT (chrec)))
	{
	case POLYNOMIAL_CHREC:
	  if (CHREC_VARIABLE (chrec) != CHREC_VARIABLE (CHREC_RIGHT (chrec)))
	    return false;
	  if (!evolution_function_is_univariate_p (CHREC_RIGHT (chrec)))
	    return false;
	  break;

	default:
	  if (tree_contains_chrecs (CHREC_RIGHT (chrec), NULL))
	    return false;
	  break;
	}

    default:
      return true;
    }
}

tree 
reset_evolution_in_loop (unsigned loop_num,
			 tree chrec, 
			 tree new_evol)
{
  if (TREE_CODE (chrec) == POLYNOMIAL_CHREC
      && CHREC_VARIABLE (chrec) > loop_num)
    return build2
      (TREE_CODE (chrec), 
       build_int_cst (NULL_TREE, CHREC_VARIABLE (chrec)), 
       reset_evolution_in_loop (loop_num, CHREC_LEFT (chrec), new_evol), 
       reset_evolution_in_loop (loop_num, CHREC_RIGHT (chrec), new_evol));
  
  while (TREE_CODE (chrec) == POLYNOMIAL_CHREC
	 && CHREC_VARIABLE (chrec) == loop_num)
    chrec = CHREC_LEFT (chrec);
  
  return build_polynomial_chrec (loop_num, chrec, new_evol);
}

bool
evolution_function_is_affine_multivariate_p (const_tree chrec, int loopnum)
{
  if (chrec == NULL_TREE)
    return false;

  switch (TREE_CODE (chrec))
    {
    case POLYNOMIAL_CHREC:
      if (evolution_function_is_invariant_rec_p (CHREC_LEFT (chrec), loopnum))
	{
	  if (evolution_function_is_invariant_rec_p (CHREC_RIGHT (chrec), loopnum))
	    return true;
	  else
	    {
	      if (TREE_CODE (CHREC_RIGHT (chrec)) == POLYNOMIAL_CHREC
		  && CHREC_VARIABLE (CHREC_RIGHT (chrec))
		     != CHREC_VARIABLE (chrec)
		  && evolution_function_is_affine_multivariate_p
		  (CHREC_RIGHT (chrec), loopnum))
		return true;
	      else
		return false;
	    }
	}
      else
	{
	  if (evolution_function_is_invariant_rec_p (CHREC_RIGHT (chrec), loopnum)
	      && TREE_CODE (CHREC_LEFT (chrec)) == POLYNOMIAL_CHREC
	      && CHREC_VARIABLE (CHREC_LEFT (chrec)) != CHREC_VARIABLE (chrec)
	      && evolution_function_is_affine_multivariate_p
	      (CHREC_LEFT (chrec), loopnum))
	    return true;
	  else
	    return false;
	}

    default:
      return false;
    }
}

tree 
chrec_convert (tree type, 
	       tree chrec)
{
  tree ct;
  
  if (automatically_generated_chrec_p (chrec))
    return chrec;
  
  ct = chrec_type (chrec);
  if (ct == type)
    return chrec;

  if (TYPE_PRECISION (ct) < TYPE_PRECISION (type))
    return count_ev_in_wider_type (type, chrec);

  switch (TREE_CODE (chrec))
    {
    case POLYNOMIAL_CHREC:
      return build_polynomial_chrec (CHREC_VARIABLE (chrec),
				     chrec_convert (type,
						    CHREC_LEFT (chrec)),
				     chrec_convert (type,
						    CHREC_RIGHT (chrec)));

    default:
      {
	tree res = fold_convert (type, chrec);

	/* Don't propagate overflows.  */
	TREE_OVERFLOW (res) = 0;
	if (CONSTANT_CLASS_P (res))
	  TREE_CONSTANT_OVERFLOW (res) = 0;

	/* But reject constants that don't fit in their type after conversion.
	   This can happen if TYPE_MIN_VALUE or TYPE_MAX_VALUE are not the
	   natural values associated with TYPE_PRECISION and TYPE_UNSIGNED,
	   and can cause problems later when computing niters of loops.  Note
	   that we don't do the check before converting because we don't want
	   to reject conversions of negative chrecs to unsigned types.  */
	if (TREE_CODE (res) == INTEGER_CST
	    && TREE_CODE (type) == INTEGER_TYPE
	    && !int_fits_type_p (res, type))
	  res = chrec_dont_know;

	return res;
      }
    }
}

unsigned
nb_vars_in_chrec (tree chrec)
{
  if (chrec == NULL_TREE)
    return 0;

  switch (TREE_CODE (chrec))
    {
    case POLYNOMIAL_CHREC:
      return 1 + nb_vars_in_chrec
	(initial_condition_in_loop_num (chrec, CHREC_VARIABLE (chrec)));

    default:
      return 0;
    }
}

static bool
is_multivariate_chrec_rec (const_tree chrec, unsigned int rec_var)
{
  if (chrec == NULL_TREE)
    return false;

  if (TREE_CODE (chrec) == POLYNOMIAL_CHREC)
    {
      if (CHREC_VARIABLE (chrec) != rec_var)
	return true;
      else
	return (is_multivariate_chrec_rec (CHREC_LEFT (chrec), rec_var)
		|| is_multivariate_chrec_rec (CHREC_RIGHT (chrec), rec_var));
    }
  else
    return false;
}

tree
chrec_convert_aggressive (tree type, tree chrec, bool *fold_conversions)
{
  tree inner_type, left, right, lc, rc, rtype;

  gcc_assert (fold_conversions != NULL);

  if (automatically_generated_chrec_p (chrec)
      || TREE_CODE (chrec) != POLYNOMIAL_CHREC)
    return NULL_TREE;

  inner_type = TREE_TYPE (chrec);
  if (TYPE_PRECISION (type) > TYPE_PRECISION (inner_type))
    return NULL_TREE;

  if (useless_type_conversion_p (type, inner_type))
    return NULL_TREE;

  if (!*fold_conversions && evolution_function_is_affine_p (chrec))
    {
      tree base, step;
      struct loop *loop;

      loop = get_chrec_loop (chrec);
      base = CHREC_LEFT (chrec);
      step = CHREC_RIGHT (chrec);
      if (convert_affine_scev (loop, type, &base, &step, NULL, true))
	return build_polynomial_chrec (loop->num, base, step);
    }
  rtype = POINTER_TYPE_P (type) ? sizetype : type;

  left = CHREC_LEFT (chrec);
  right = CHREC_RIGHT (chrec);
  lc = chrec_convert_aggressive (type, left, fold_conversions);
  if (!lc)
    lc = chrec_convert (type, left, NULL);
  rc = chrec_convert_aggressive (rtype, right, fold_conversions);
  if (!rc)
    rc = chrec_convert (rtype, right, NULL);

  *fold_conversions = true;

  return build_polynomial_chrec (CHREC_VARIABLE (chrec), lc, rc);
}