Beispiel #1
0
static int
forward_propagate_into_cond (gimple_stmt_iterator *gsi_p)
{
  gimple stmt = gsi_stmt (*gsi_p);
  int did_something = 0;

  do {
    tree tmp = NULL_TREE;
    tree cond = gimple_assign_rhs1 (stmt);
    tree name, rhs0 = NULL_TREE, rhs1 = NULL_TREE;
    gimple def_stmt;
    bool single_use0_p = false, single_use1_p = false;

    /* We can do tree combining on SSA_NAME and comparison expressions.  */
    if (COMPARISON_CLASS_P (cond)
	&& TREE_CODE (TREE_OPERAND (cond, 0)) == SSA_NAME)
      {
	/* For comparisons use the first operand, that is likely to
	   simplify comparisons against constants.  */
	name = TREE_OPERAND (cond, 0);
	def_stmt = get_prop_source_stmt (name, false, &single_use0_p);
	if (def_stmt && can_propagate_from (def_stmt))
	  {
	    tree op1 = TREE_OPERAND (cond, 1);
	    rhs0 = rhs_to_tree (TREE_TYPE (op1), def_stmt);
	    tmp = combine_cond_expr_cond (TREE_CODE (cond), boolean_type_node,
					  rhs0, op1, !single_use0_p);
	  }
	/* If that wasn't successful, try the second operand.  */
	if (tmp == NULL_TREE
	    && TREE_CODE (TREE_OPERAND (cond, 1)) == SSA_NAME)
	  {
	    tree op0 = TREE_OPERAND (cond, 0);
	    name = TREE_OPERAND (cond, 1);
	    def_stmt = get_prop_source_stmt (name, false, &single_use1_p);
	    if (!def_stmt || !can_propagate_from (def_stmt))
	      return did_something;

	    rhs1 = rhs_to_tree (TREE_TYPE (op0), def_stmt);
	    tmp = combine_cond_expr_cond (TREE_CODE (cond), boolean_type_node,
					  op0, rhs1, !single_use1_p);
	  }
	/* If that wasn't successful either, try both operands.  */
	if (tmp == NULL_TREE
	    && rhs0 != NULL_TREE
	    && rhs1 != NULL_TREE)
	  tmp = combine_cond_expr_cond (TREE_CODE (cond), boolean_type_node,
					rhs0, fold_convert (TREE_TYPE (rhs0),
							    rhs1),
					!(single_use0_p && single_use1_p));
      }
    else if (TREE_CODE (cond) == SSA_NAME)
      {
	name = cond;
	def_stmt = get_prop_source_stmt (name, true, NULL);
	if (def_stmt || !can_propagate_from (def_stmt))
	  return did_something;

	rhs0 = gimple_assign_rhs1 (def_stmt);
	tmp = combine_cond_expr_cond (NE_EXPR, boolean_type_node, rhs0,
				      build_int_cst (TREE_TYPE (rhs0), 0),
				      false);
      }

    if (tmp)
      {
	if (dump_file && tmp)
	  {
	    fprintf (dump_file, "  Replaced '");
	    print_generic_expr (dump_file, cond, 0);
	    fprintf (dump_file, "' with '");
	    print_generic_expr (dump_file, tmp, 0);
	    fprintf (dump_file, "'\n");
	  }

	gimple_assign_set_rhs_from_tree (gsi_p, unshare_expr (tmp));
	stmt = gsi_stmt (*gsi_p);
	update_stmt (stmt);

	/* Remove defining statements.  */
	remove_prop_source_from_use (name, NULL);

	if (is_gimple_min_invariant (tmp))
	  did_something = 2;
	else if (did_something == 0)
	  did_something = 1;

	/* Continue combining.  */
	continue;
      }

    break;
  } while (1);

  return did_something;
}
static int
forward_propagate_into_gimple_cond (gimple stmt)
{
  int did_something = 0;
  location_t loc = gimple_location (stmt);

  do {
    tree tmp = NULL_TREE;
    tree name, rhs0 = NULL_TREE, rhs1 = NULL_TREE;
    gimple def_stmt;
    bool single_use0_p = false, single_use1_p = false;
    enum tree_code code = gimple_cond_code (stmt);

    /* We can do tree combining on SSA_NAME and comparison expressions.  */
    if (TREE_CODE_CLASS (gimple_cond_code (stmt)) == tcc_comparison
        && TREE_CODE (gimple_cond_lhs (stmt)) == SSA_NAME)
      {
	/* For comparisons use the first operand, that is likely to
	   simplify comparisons against constants.  */
	name = gimple_cond_lhs (stmt);
	def_stmt = get_prop_source_stmt (name, false, &single_use0_p);
	if (def_stmt && can_propagate_from (def_stmt))
	  {
	    tree op1 = gimple_cond_rhs (stmt);
	    rhs0 = rhs_to_tree (TREE_TYPE (op1), def_stmt);
	    tmp = combine_cond_expr_cond (loc, code, boolean_type_node, rhs0,
					  op1, !single_use0_p);
	  }
	/* If that wasn't successful, try the second operand.  */
	if (tmp == NULL_TREE
	    && TREE_CODE (gimple_cond_rhs (stmt)) == SSA_NAME)
	  {
	    tree op0 = gimple_cond_lhs (stmt);
	    name = gimple_cond_rhs (stmt);
	    def_stmt = get_prop_source_stmt (name, false, &single_use1_p);
	    if (!def_stmt || !can_propagate_from (def_stmt))
	      return did_something;

	    rhs1 = rhs_to_tree (TREE_TYPE (op0), def_stmt);
	    tmp = combine_cond_expr_cond (loc, code, boolean_type_node, op0,
					  rhs1, !single_use1_p);
	  }
	/* If that wasn't successful either, try both operands.  */
	if (tmp == NULL_TREE
	    && rhs0 != NULL_TREE
	    && rhs1 != NULL_TREE)
	  tmp = combine_cond_expr_cond (loc, code, boolean_type_node, rhs0,
					fold_convert_loc (loc,
							  TREE_TYPE (rhs0),
							  rhs1),
					!(single_use0_p && single_use1_p));
      }

    if (tmp)
      {
	if (dump_file && tmp)
	  {
            tree cond = build2 (gimple_cond_code (stmt),
				boolean_type_node,
				gimple_cond_lhs (stmt),
				gimple_cond_rhs (stmt));
	    fprintf (dump_file, "  Replaced '");
	    print_generic_expr (dump_file, cond, 0);
	    fprintf (dump_file, "' with '");
	    print_generic_expr (dump_file, tmp, 0);
	    fprintf (dump_file, "'\n");
	  }

        gimple_cond_set_condition_from_tree (stmt, unshare_expr (tmp));
	update_stmt (stmt);

	/* Remove defining statements.  */
	remove_prop_source_from_use (name, NULL);

	if (is_gimple_min_invariant (tmp))
	  did_something = 2;
	else if (did_something == 0)
	  did_something = 1;

	/* Continue combining.  */
	continue;
      }

    break;
  } while (1);

  return did_something;
}