C++ CONSTANT_CLASS_P函数代码示例

tree
gimple_simplify (enum tree_code code, tree type,
		 tree op0, tree op1,
		 gimple_seq *seq, tree (*valueize)(tree))
{
  if (constant_for_folding (op0) && constant_for_folding (op1))
    {
      tree res = const_binop (code, type, op0, op1);
      if (res != NULL_TREE
	  && CONSTANT_CLASS_P (res))
	return res;
    }

  /* Canonicalize operand order both for matching and fallback stmt
     generation.  */
  if ((commutative_tree_code (code)
       || TREE_CODE_CLASS (code) == tcc_comparison)
      && tree_swap_operands_p (op0, op1, false))
    {
      tree tem = op0;
      op0 = op1;
      op1 = tem;
      if (TREE_CODE_CLASS (code) == tcc_comparison)
	code = swap_tree_comparison (code);
    }

  code_helper rcode;
  tree ops[3] = {};
  if (!gimple_simplify (&rcode, ops, seq, valueize,
			code, type, op0, op1))
    return NULL_TREE;
  return maybe_push_res_to_seq (rcode, type, ops, seq);
}

static inline bool
constant_for_folding (tree t)
{
  return (CONSTANT_CLASS_P (t)
	  /* The following is only interesting to string builtins.  */
	  || (TREE_CODE (t) == ADDR_EXPR
	      && TREE_CODE (TREE_OPERAND (t, 0)) == STRING_CST));
}

bool
is_gimple_mem_ref_addr (tree t)
{
  return (is_gimple_reg (t)
	  || TREE_CODE (t) == INTEGER_CST
	  || (TREE_CODE (t) == ADDR_EXPR
	      && (CONSTANT_CLASS_P (TREE_OPERAND (t, 0))
		  || decl_address_invariant_p (TREE_OPERAND (t, 0)))));
}

static bool
ptr_deref_may_alias_decl_p (tree ptr, tree decl)
{
  struct ptr_info_def *pi;

  gcc_assert ((TREE_CODE (ptr) == SSA_NAME
	       || TREE_CODE (ptr) == ADDR_EXPR
	       || TREE_CODE (ptr) == INTEGER_CST)
	      && (TREE_CODE (decl) == VAR_DECL
		  || TREE_CODE (decl) == PARM_DECL
		  || TREE_CODE (decl) == RESULT_DECL));

  /* Non-aliased variables can not be pointed to.  */
  if (!may_be_aliased (decl))
    return false;

  /* ADDR_EXPR pointers either just offset another pointer or directly
     specify the pointed-to set.  */
  if (TREE_CODE (ptr) == ADDR_EXPR)
    {
      tree base = get_base_address (TREE_OPERAND (ptr, 0));
      if (base
	  && INDIRECT_REF_P (base))
	ptr = TREE_OPERAND (base, 0);
      else if (base
	       && SSA_VAR_P (base))
	return operand_equal_p (base, decl, 0);
      else if (base
	       && CONSTANT_CLASS_P (base))
	return false;
      else
	return true;
    }

  /* We can end up with dereferencing constant pointers.
     Just bail out in this case.  */
  if (TREE_CODE (ptr) == INTEGER_CST)
    return true;

  /* If we do not have useful points-to information for this pointer
     we cannot disambiguate anything else.  */
  pi = SSA_NAME_PTR_INFO (ptr);
  if (!pi)
    return true;

  /* If the decl can be used as a restrict tag and we have a restrict
     pointer and that pointers points-to set doesn't contain this decl
     then they can't alias.  */
  if (DECL_RESTRICTED_P (decl)
      && TYPE_RESTRICT (TREE_TYPE (ptr))
      && pi->pt.vars_contains_restrict)
    return bitmap_bit_p (pi->pt.vars, DECL_UID (decl));

  return pt_solution_includes (&pi->pt, decl);
}

bool
gimple_resimplify3 (gimple_seq *seq,
		    code_helper *res_code, tree type, tree *res_ops,
		    tree (*valueize)(tree))
{
  if (constant_for_folding (res_ops[0]) && constant_for_folding (res_ops[1])
      && constant_for_folding (res_ops[2]))
    {
      tree tem = NULL_TREE;
      if (res_code->is_tree_code ())
	tem = fold_ternary/*_to_constant*/ (*res_code, type, res_ops[0],
					    res_ops[1], res_ops[2]);
      else
	tem = fold_const_call (combined_fn (*res_code), type,
			       res_ops[0], res_ops[1], res_ops[2]);
      if (tem != NULL_TREE
	  && CONSTANT_CLASS_P (tem))
	{
	  if (TREE_OVERFLOW_P (tem))
	    tem = drop_tree_overflow (tem);
	  res_ops[0] = tem;
	  res_ops[1] = NULL_TREE;
	  res_ops[2] = NULL_TREE;
	  *res_code = TREE_CODE (res_ops[0]);
	  return true;
	}
    }

  /* Canonicalize operand order.  */
  bool canonicalized = false;
  if (res_code->is_tree_code ()
      && commutative_ternary_tree_code (*res_code)
      && tree_swap_operands_p (res_ops[0], res_ops[1]))
    {
      std::swap (res_ops[0], res_ops[1]);
      canonicalized = true;
    }

  code_helper res_code2;
  tree res_ops2[3] = {};
  if (gimple_simplify (&res_code2, res_ops2, seq, valueize,
		       *res_code, type,
		       res_ops[0], res_ops[1], res_ops[2]))
    {
      *res_code = res_code2;
      res_ops[0] = res_ops2[0];
      res_ops[1] = res_ops2[1];
      res_ops[2] = res_ops2[2];
      return true;
    }

  return canonicalized;
}

bool
is_gimple_ip_invariant_address (const_tree t)
{
  const_tree op;

  if (TREE_CODE (t) != ADDR_EXPR)
    return false;

  op = strip_invariant_refs (TREE_OPERAND (t, 0));
  if (!op)
    return false;

  if (TREE_CODE (op) == MEM_REF)
    {
      const_tree op0 = TREE_OPERAND (op, 0);
      return (TREE_CODE (op0) == ADDR_EXPR
	      && (CONSTANT_CLASS_P (TREE_OPERAND (op0, 0))
		  || decl_address_ip_invariant_p (TREE_OPERAND (op0, 0))));
    }

  return CONSTANT_CLASS_P (op) || decl_address_ip_invariant_p (op);
}

static bool
gimple_resimplify1 (gimple_seq *seq,
		    code_helper *res_code, tree type, tree *res_ops,
		    tree (*valueize)(tree))
{
  if (constant_for_folding (res_ops[0]))
    {
      tree tem = NULL_TREE;
      if (res_code->is_tree_code ())
	tem = const_unop (*res_code, type, res_ops[0]);
      else
	{
	  tree decl = builtin_decl_implicit (*res_code);
	  if (decl)
	    {
	      tem = fold_builtin_n (UNKNOWN_LOCATION, decl, res_ops, 1, false);
	      if (tem)
		{
		  /* fold_builtin_n wraps the result inside a NOP_EXPR.  */
		  STRIP_NOPS (tem);
		  tem = fold_convert (type, tem);
		}
	    }
	}
      if (tem != NULL_TREE
	  && CONSTANT_CLASS_P (tem))
	{
	  res_ops[0] = tem;
	  res_ops[1] = NULL_TREE;
	  res_ops[2] = NULL_TREE;
	  *res_code = TREE_CODE (res_ops[0]);
	  return true;
	}
    }

  code_helper res_code2;
  tree res_ops2[3] = {};
  if (gimple_simplify (&res_code2, res_ops2, seq, valueize,
		       *res_code, type, res_ops[0]))
    {
      *res_code = res_code2;
      res_ops[0] = res_ops2[0];
      res_ops[1] = res_ops2[1];
      res_ops[2] = res_ops2[2];
      return true;
    }

  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;
      }
    }
}

static tree
fold_const_reduction (tree type, tree arg, tree_code code)
{
  unsigned HOST_WIDE_INT nelts;
  if (TREE_CODE (arg) != VECTOR_CST
      || !VECTOR_CST_NELTS (arg).is_constant (&nelts))
    return NULL_TREE;

  tree res = VECTOR_CST_ELT (arg, 0);
  for (unsigned HOST_WIDE_INT i = 1; i < nelts; i++)
    {
      res = const_binop (code, type, res, VECTOR_CST_ELT (arg, i));
      if (res == NULL_TREE || !CONSTANT_CLASS_P (res))
	return NULL_TREE;
    }
  return res;
}

static tree
fold_const_fold_left (tree type, tree arg0, tree arg1, tree_code code)
{
  if (TREE_CODE (arg1) != VECTOR_CST)
    return NULL_TREE;

  unsigned HOST_WIDE_INT nelts;
  if (!VECTOR_CST_NELTS (arg1).is_constant (&nelts))
    return NULL_TREE;

  for (unsigned HOST_WIDE_INT i = 0; i < nelts; i++)
    {
      arg0 = const_binop (code, type, arg0, VECTOR_CST_ELT (arg1, i));
      if (arg0 == NULL_TREE || !CONSTANT_CLASS_P (arg0))
	return NULL_TREE;
    }
  return arg0;
}

static bool
constant_after_peeling (tree op, gimple *stmt, struct loop *loop)
{
  affine_iv iv;

  if (is_gimple_min_invariant (op))
    return true;

  /* We can still fold accesses to constant arrays when index is known.  */
  if (TREE_CODE (op) != SSA_NAME)
    {
      tree base = op;

      /* First make fast look if we see constant array inside.  */
      while (handled_component_p (base))
	base = TREE_OPERAND (base, 0);
      if ((DECL_P (base)
	   && ctor_for_folding (base) != error_mark_node)
	  || CONSTANT_CLASS_P (base))
	{
	  /* If so, see if we understand all the indices.  */
	  base = op;
	  while (handled_component_p (base))
	    {
	      if (TREE_CODE (base) == ARRAY_REF
		  && !constant_after_peeling (TREE_OPERAND (base, 1), stmt, loop))
		return false;
	      base = TREE_OPERAND (base, 0);
	    }
	  return true;
	}
      return false;
    }

  /* Induction variables are constants.  */
  if (!simple_iv (loop, loop_containing_stmt (stmt), op, &iv, false))
    return false;
  if (!is_gimple_min_invariant (iv.base))
    return false;
  if (!is_gimple_min_invariant (iv.step))
    return false;
  return true;
}

tree
gimple_simplify (enum built_in_function fn, tree type,
		 tree arg0,
		 gimple_seq *seq, tree (*valueize)(tree))
{
  if (constant_for_folding (arg0))
    {
      tree res = fold_const_call (as_combined_fn (fn), type, arg0);
      if (res && CONSTANT_CLASS_P (res))
	return res;
    }

  code_helper rcode;
  tree ops[3] = {};
  if (!gimple_simplify (&rcode, ops, seq, valueize,
			as_combined_fn (fn), type, arg0))
    return NULL_TREE;
  return maybe_push_res_to_seq (rcode, type, ops, seq);
}

bool
gimple_resimplify1 (gimple_seq *seq,
		    code_helper *res_code, tree type, tree *res_ops,
		    tree (*valueize)(tree))
{
  if (constant_for_folding (res_ops[0]))
    {
      tree tem = NULL_TREE;
      if (res_code->is_tree_code ())
	tem = const_unop (*res_code, type, res_ops[0]);
      else
	tem = fold_const_call (combined_fn (*res_code), type, res_ops[0]);
      if (tem != NULL_TREE
	  && CONSTANT_CLASS_P (tem))
	{
	  if (TREE_OVERFLOW_P (tem))
	    tem = drop_tree_overflow (tem);
	  res_ops[0] = tem;
	  res_ops[1] = NULL_TREE;
	  res_ops[2] = NULL_TREE;
	  *res_code = TREE_CODE (res_ops[0]);
	  return true;
	}
    }

  code_helper res_code2;
  tree res_ops2[3] = {};
  if (gimple_simplify (&res_code2, res_ops2, seq, valueize,
		       *res_code, type, res_ops[0]))
    {
      *res_code = res_code2;
      res_ops[0] = res_ops2[0];
      res_ops[1] = res_ops2[1];
      res_ops[2] = res_ops2[2];
      return true;
    }

  return false;
}

bool
is_gimple_address (const_tree t)
{
  tree op;

  if (TREE_CODE (t) != ADDR_EXPR)
    return false;

  op = TREE_OPERAND (t, 0);
  while (handled_component_p (op))
    {
      if ((TREE_CODE (op) == ARRAY_REF
	   || TREE_CODE (op) == ARRAY_RANGE_REF)
	  && !is_gimple_val (TREE_OPERAND (op, 1)))
	    return false;

      op = TREE_OPERAND (op, 0);
    }

  if (CONSTANT_CLASS_P (op) || TREE_CODE (op) == MEM_REF)
    return true;

  switch (TREE_CODE (op))
    {
    case PARM_DECL:
    case RESULT_DECL:
    case LABEL_DECL:
    case FUNCTION_DECL:
    case VAR_DECL:
    case CONST_DECL:
      return true;

    default:
      return false;
    }
}

static bool
gimple_resimplify3 (gimple_seq *seq,
		    code_helper *res_code, tree type, tree *res_ops,
		    tree (*valueize)(tree))
{
  if (constant_for_folding (res_ops[0]) && constant_for_folding (res_ops[1])
      && constant_for_folding (res_ops[2]))
    {
      tree tem = NULL_TREE;
      if (res_code->is_tree_code ())
	tem = fold_ternary/*_to_constant*/ (*res_code, type, res_ops[0],
					    res_ops[1], res_ops[2]);
      else
	{
	  tree decl = builtin_decl_implicit (*res_code);
	  if (decl)
	    {
	      tem = fold_builtin_n (UNKNOWN_LOCATION, decl, res_ops, 3, false);
	      if (tem)
		{
		  /* fold_builtin_n wraps the result inside a NOP_EXPR.  */
		  STRIP_NOPS (tem);
		  tem = fold_convert (type, tem);
		}
	    }
	}
      if (tem != NULL_TREE
	  && CONSTANT_CLASS_P (tem))
	{
	  res_ops[0] = tem;
	  res_ops[1] = NULL_TREE;
	  res_ops[2] = NULL_TREE;
	  *res_code = TREE_CODE (res_ops[0]);
	  return true;
	}
    }

  /* Canonicalize operand order.  */
  bool canonicalized = false;
  if (res_code->is_tree_code ()
      && commutative_ternary_tree_code (*res_code)
      && tree_swap_operands_p (res_ops[0], res_ops[1], false))
    {
      tree tem = res_ops[0];
      res_ops[0] = res_ops[1];
      res_ops[1] = tem;
      canonicalized = true;
    }

  code_helper res_code2;
  tree res_ops2[3] = {};
  if (gimple_simplify (&res_code2, res_ops2, seq, valueize,
		       *res_code, type,
		       res_ops[0], res_ops[1], res_ops[2]))
    {
      *res_code = res_code2;
      res_ops[0] = res_ops2[0];
      res_ops[1] = res_ops2[1];
      res_ops[2] = res_ops2[2];
      return true;
    }

  return canonicalized;
}