static void
insert_value_copy_on_edge (edge e, int dest, tree src, source_location locus)
{
  rtx seq, x;
  enum machine_mode dest_mode, src_mode;
  int unsignedp;
  tree var;

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file,
	       "Inserting a value copy on edge BB%d->BB%d : PART.%d = ",
	       e->src->index,
	       e->dest->index, dest);
      print_generic_expr (dump_file, src, TDF_SLIM);
      fprintf (dump_file, "\n");
    }

  gcc_assert (SA.partition_to_pseudo[dest]);

  set_location_for_edge (e);
  /* If a locus is provided, override the default.  */
  if (locus)
    set_curr_insn_source_location (locus);

  start_sequence ();

  var = SSA_NAME_VAR (partition_to_var (SA.map, dest));
  src_mode = TYPE_MODE (TREE_TYPE (src));
  dest_mode = GET_MODE (SA.partition_to_pseudo[dest]);
  gcc_assert (src_mode == TYPE_MODE (TREE_TYPE (var)));
  gcc_assert (!REG_P (SA.partition_to_pseudo[dest])
	      || dest_mode == promote_decl_mode (var, &unsignedp));

  if (src_mode != dest_mode)
    {
      x = expand_expr (src, NULL, src_mode, EXPAND_NORMAL);
      x = convert_modes (dest_mode, src_mode, x, unsignedp);
    }
  else if (src_mode == BLKmode)
    {
      x = SA.partition_to_pseudo[dest];
      store_expr (src, x, 0, false);
    }
  else
    x = expand_expr (src, SA.partition_to_pseudo[dest],
		     dest_mode, EXPAND_NORMAL);

  if (x != SA.partition_to_pseudo[dest])
    emit_move_insn (SA.partition_to_pseudo[dest], x);
  seq = get_insns ();
  end_sequence ();

  insert_insn_on_edge (seq, e);
}

static void
maybe_dump_rtl_for_tree_stmt (tree stmt, rtx since)
{
  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "\n;; ");
      print_generic_expr (dump_file, stmt, TDF_SLIM);
      fprintf (dump_file, "\n");

      print_rtl (dump_file, since ? NEXT_INSN (since) : since);
    }
}

/* Dump ADDR into dump_file.  */
static void
chkp_print_addr (const address_t &addr)
{
    unsigned int n = 0;
    for (n = 0; n < addr.pol.length (); n++)
    {
        if (n > 0)
            fprintf (dump_file, " + ");

        if (addr.pol[n].var == NULL_TREE)
            print_generic_expr (dump_file, addr.pol[n].cst, 0);
        else
        {
            if (TREE_CODE (addr.pol[n].cst) != INTEGER_CST
                    || !integer_onep (addr.pol[n].cst))
            {
                print_generic_expr (dump_file, addr.pol[n].cst, 0);
                fprintf (dump_file, " * ");
            }
            print_generic_expr (dump_file, addr.pol[n].var, 0);
        }
    }
}

void
const_and_copies::record_const_or_copy (tree x, tree y, tree prev_x)
{
  /* Y may be NULL if we are invalidating entries in the table.  */
  if (y && TREE_CODE (y) == SSA_NAME)
    {
      tree tmp = SSA_NAME_VALUE (y);
      y = tmp ? tmp : y;
    }

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "0>>> COPY ");
      print_generic_expr (dump_file, x, 0);
      fprintf (dump_file, " = ");
      print_generic_expr (dump_file, y, 0);
      fprintf (dump_file, "\n");
    }

  set_ssa_name_value (x, y);
  stack.reserve (2);
  stack.quick_push (prev_x);
  stack.quick_push (x);
}

static void
forward_propagate_into_cond (tree cond_expr)
{
  gcc_assert (TREE_CODE (cond_expr) == COND_EXPR);

  while (1)
    {
      tree test_var = NULL_TREE;
      tree cond = COND_EXPR_COND (cond_expr);
      tree new_cond = forward_propagate_into_cond_1 (cond, &test_var);

      /* Return if unsuccessful.  */
      if (new_cond == NULL_TREE)
	break;

      /* Dump details.  */
      if (dump_file && (dump_flags & TDF_DETAILS))
	{
	  fprintf (dump_file, "  Replaced '");
	  print_generic_expr (dump_file, cond, dump_flags);
	  fprintf (dump_file, "' with '");
	  print_generic_expr (dump_file, new_cond, dump_flags);
	  fprintf (dump_file, "'\n");
	}

      COND_EXPR_COND (cond_expr) = new_cond;
      update_stmt (cond_expr);

      if (has_zero_uses (test_var))
	{
	  tree def = SSA_NAME_DEF_STMT (test_var);
	  block_stmt_iterator bsi = bsi_for_stmt (def);
	  bsi_remove (&bsi);
	}
    }
}

/* Find all checks in current function and store info about them
   in check_infos.  */
static void
chkp_gather_checks_info (void)
{
    basic_block bb;
    gimple_stmt_iterator i;

    if (dump_file && (dump_flags & TDF_DETAILS))
        fprintf (dump_file, "Gathering information about checks...\n");

    chkp_init_check_info ();

    FOR_EACH_BB_FN (bb, cfun)
    {
        struct bb_checks *bbc = &check_infos[bb->index];

        if (dump_file && (dump_flags & TDF_DETAILS))
            fprintf (dump_file, "Searching checks in BB%d...\n", bb->index);

        for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i))
        {
            gimple *stmt = gsi_stmt (i);

            if (gimple_code (stmt) != GIMPLE_CALL)
                continue;

            if (gimple_call_fndecl (stmt) == chkp_checkl_fndecl
                    || gimple_call_fndecl (stmt) == chkp_checku_fndecl)
            {
                struct check_info ci;

                chkp_fill_check_info (stmt, &ci);
                bbc->checks.safe_push (ci);

                if (dump_file && (dump_flags & TDF_DETAILS))
                {
                    fprintf (dump_file, "Adding check information:\n");
                    fprintf (dump_file, "  bounds: ");
                    print_generic_expr (dump_file, ci.bounds, 0);
                    fprintf (dump_file, "\n  address: ");
                    chkp_print_addr (ci.addr);
                    fprintf (dump_file, "\n  check: ");
                    print_gimple_stmt (dump_file, stmt, 0, 0);
                }
            }
        }
    }
}

static void
create_canonical_iv (struct loop *loop, edge exit, tree niter)
{
  edge in;
  tree type, var;
  gcond *cond;
  gimple_stmt_iterator incr_at;
  enum tree_code cmp;

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "Added canonical iv to loop %d, ", loop->num);
      print_generic_expr (dump_file, niter, TDF_SLIM);
      fprintf (dump_file, " iterations.\n");
    }

  cond = as_a <gcond *> (last_stmt (exit->src));
  in = EDGE_SUCC (exit->src, 0);
  if (in == exit)
    in = EDGE_SUCC (exit->src, 1);

  /* Note that we do not need to worry about overflows, since
     type of niter is always unsigned and all comparisons are
     just for equality/nonequality -- i.e. everything works
     with a modulo arithmetics.  */

  type = TREE_TYPE (niter);
  niter = fold_build2 (PLUS_EXPR, type,
		       niter,
		       build_int_cst (type, 1));
  incr_at = gsi_last_bb (in->src);
  create_iv (niter,
	     build_int_cst (type, -1),
	     NULL_TREE, loop,
	     &incr_at, false, NULL, &var);

  cmp = (exit->flags & EDGE_TRUE_VALUE) ? EQ_EXPR : NE_EXPR;
  gimple_cond_set_code (cond, cmp);
  gimple_cond_set_lhs (cond, var);
  gimple_cond_set_rhs (cond, build_int_cst (type, 0));
  update_stmt (cond);
}

void print_ssa_operands() {
    tree var;
    ssa_op_iter iter;
    gimple_stmt_iterator gsi;
    basic_block bb;

    fprintf (stdout, "Print all SSA operands\n");
    FOR_ALL_BB_FN(bb, cfun) {
        for (gsi = gsi_start_bb (bb);  !(gsi_end_p (gsi)); gsi_next(&gsi)) {
            gimple *stmt = gsi_stmt(gsi);
            FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_ALL_OPERANDS) {
                print_gimple_stmt(stdout, stmt,1, 1);
                print_generic_expr (stdout, var, TDF_SLIM);
                printf("\n");
                tree ref = get_inner_ref (var);
                if (ref)
                    printf ("Inner reference: %s\n", get_name(ref));
            }
        }
    }

static unsigned int
increase_alignment (void)
{
  struct varpool_node *vnode;

  /* Increase the alignment of all global arrays for vectorization.  */
  for (vnode = varpool_nodes_queue;
       vnode;
       vnode = vnode->next_needed)
    {
      tree vectype, decl = vnode->decl;
      tree t;
      unsigned int alignment;

      t = TREE_TYPE(decl);
      if (TREE_CODE (t) != ARRAY_TYPE)
        continue;
      vectype = get_vectype_for_scalar_type (strip_array_types (t));
      if (!vectype)
        continue;
      alignment = TYPE_ALIGN (vectype);
      if (DECL_ALIGN (decl) >= alignment)
        continue;

      if (vect_can_force_dr_alignment_p (decl, alignment))
        {
          DECL_ALIGN (decl) = TYPE_ALIGN (vectype);
          DECL_USER_ALIGN (decl) = 1;
          if (dump_file)
            {
              fprintf (dump_file, "Increasing alignment of decl: ");
              print_generic_expr (dump_file, decl, TDF_SLIM);
	      fprintf (dump_file, "\n");
            }
        }
    }
  return 0;
}

static bool
verify_def (basic_block bb, basic_block *definition_block, tree ssa_name,
	    tree stmt, bool is_virtual)
{
  if (verify_ssa_name (ssa_name, is_virtual))
    goto err;

  if (definition_block[SSA_NAME_VERSION (ssa_name)])
    {
      error ("SSA_NAME created in two different blocks %i and %i",
	     definition_block[SSA_NAME_VERSION (ssa_name)]->index, bb->index);
      goto err;
    }

  definition_block[SSA_NAME_VERSION (ssa_name)] = bb;

  if (SSA_NAME_DEF_STMT (ssa_name) != stmt)
    {
      error ("SSA_NAME_DEF_STMT is wrong");
      fprintf (stderr, "Expected definition statement:\n");
      print_generic_stmt (stderr, SSA_NAME_DEF_STMT (ssa_name), TDF_VOPS);
      fprintf (stderr, "\nActual definition statement:\n");
      print_generic_stmt (stderr, stmt, TDF_VOPS);
      goto err;
    }

  return false;

err:
  fprintf (stderr, "while verifying SSA_NAME ");
  print_generic_expr (stderr, ssa_name, 0);
  fprintf (stderr, " in statement\n");
  print_generic_stmt (stderr, stmt, TDF_VOPS);

  return true;
}

tree
chrec_apply (unsigned var,
	     tree chrec,
	     tree x)
{
  tree type = chrec_type (chrec);
  tree res = chrec_dont_know;

  if (automatically_generated_chrec_p (chrec)
      || automatically_generated_chrec_p (x)

      /* When the symbols are defined in an outer loop, it is possible
	 to symbolically compute the apply, since the symbols are
	 constants with respect to the varying loop.  */
      || chrec_contains_symbols_defined_in_loop (chrec, var))
    return chrec_dont_know;

  if (dump_file && (dump_flags & TDF_SCEV))
    fprintf (dump_file, "(chrec_apply \n");

  if (TREE_CODE (x) == INTEGER_CST && SCALAR_FLOAT_TYPE_P (type))
    x = build_real_from_int_cst (type, x);

  switch (TREE_CODE (chrec))
    {
    case POLYNOMIAL_CHREC:
      if (evolution_function_is_affine_p (chrec))
	{
	  if (CHREC_VARIABLE (chrec) != var)
	    return build_polynomial_chrec
	      (CHREC_VARIABLE (chrec),
	       chrec_apply (var, CHREC_LEFT (chrec), x),
	       chrec_apply (var, CHREC_RIGHT (chrec), x));

	  /* "{a, +, b} (x)"  ->  "a + b*x".  */
	  x = chrec_convert_rhs (type, x, NULL);
	  res = chrec_fold_multiply (TREE_TYPE (x), CHREC_RIGHT (chrec), x);
	  res = chrec_fold_plus (type, CHREC_LEFT (chrec), res);
	}
      else if (TREE_CODE (x) == INTEGER_CST
	       && tree_int_cst_sgn (x) == 1)
	/* testsuite/.../ssa-chrec-38.c.  */
	res = chrec_evaluate (var, chrec, x, 0);
      else
	res = chrec_dont_know;
      break;

    CASE_CONVERT:
      res = chrec_convert (TREE_TYPE (chrec),
			   chrec_apply (var, TREE_OPERAND (chrec, 0), x),
			   NULL);
      break;

    default:
      res = chrec;
      break;
    }

  if (dump_file && (dump_flags & TDF_SCEV))
    {
      fprintf (dump_file, "  (varying_loop = %d\n", var);
      fprintf (dump_file, ")\n  (chrec = ");
      print_generic_expr (dump_file, chrec, 0);
      fprintf (dump_file, ")\n  (x = ");
      print_generic_expr (dump_file, x, 0);
      fprintf (dump_file, ")\n  (res = ");
      print_generic_expr (dump_file, res, 0);
      fprintf (dump_file, "))\n");
    }

  return res;
}

static bool
copy_rename_partition_coalesce (var_map map, tree var1, tree var2, FILE *debug)
{
  int p1, p2, p3;
  tree root1, root2;
  tree rep1, rep2;
  bool ign1, ign2, abnorm;

  gcc_assert (TREE_CODE (var1) == SSA_NAME);
  gcc_assert (TREE_CODE (var2) == SSA_NAME);

  register_ssa_partition (map, var1);
  register_ssa_partition (map, var2);

  p1 = partition_find (map->var_partition, SSA_NAME_VERSION (var1));
  p2 = partition_find (map->var_partition, SSA_NAME_VERSION (var2));

  if (debug)
    {
      fprintf (debug, "Try : ");
      print_generic_expr (debug, var1, TDF_SLIM);
      fprintf (debug, "(P%d) & ", p1);
      print_generic_expr (debug, var2, TDF_SLIM);
      fprintf (debug, "(P%d)", p2);
    }

  gcc_assert (p1 != NO_PARTITION);
  gcc_assert (p2 != NO_PARTITION);

  if (p1 == p2)
    {
      if (debug)
	fprintf (debug, " : Already coalesced.\n");
      return false;
    }

  rep1 = partition_to_var (map, p1);
  rep2 = partition_to_var (map, p2);
  root1 = SSA_NAME_VAR (rep1);
  root2 = SSA_NAME_VAR (rep2);
  if (!root1 && !root2)
    return false;

  /* Don't coalesce if one of the variables occurs in an abnormal PHI.  */
  abnorm = (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rep1)
	    || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rep2));
  if (abnorm)
    {
      if (debug)
	fprintf (debug, " : Abnormal PHI barrier.  No coalesce.\n");
      return false;
    }

  /* Partitions already have the same root, simply merge them.  */
  if (root1 == root2)
    {
      p1 = partition_union (map->var_partition, p1, p2);
      if (debug)
	fprintf (debug, " : Same root, coalesced --> P%d.\n", p1);
      return false;
    }

  /* Never attempt to coalesce 2 different parameters.  */
  if ((root1 && TREE_CODE (root1) == PARM_DECL)
      && (root2 && TREE_CODE (root2) == PARM_DECL))
    {
      if (debug)
        fprintf (debug, " : 2 different PARM_DECLS. No coalesce.\n");
      return false;
    }

  if ((root1 && TREE_CODE (root1) == RESULT_DECL)
      != (root2 && TREE_CODE (root2) == RESULT_DECL))
    {
      if (debug)
        fprintf (debug, " : One root a RESULT_DECL. No coalesce.\n");
      return false;
    }

  ign1 = !root1 || (TREE_CODE (root1) == VAR_DECL && DECL_IGNORED_P (root1));
  ign2 = !root2 || (TREE_CODE (root2) == VAR_DECL && DECL_IGNORED_P (root2));

  /* Refrain from coalescing user variables, if requested.  */
  if (!ign1 && !ign2)
    {
      if (flag_ssa_coalesce_vars && DECL_FROM_INLINE (root2))
	ign2 = true;
      else if (flag_ssa_coalesce_vars && DECL_FROM_INLINE (root1))
	ign1 = true;
      else if (flag_ssa_coalesce_vars != 2)
	{
	  if (debug)
	    fprintf (debug, " : 2 different USER vars. No coalesce.\n");
	  return false;
	}
      else
	ign2 = true;
    }

  /* If both values have default defs, we can't coalesce.  If only one has a
//.........这里部分代码省略.........

//.........这里部分代码省略.........
	      tree rhs = gimple_assign_rhs1 (stmt);

	      updated |= copy_rename_partition_coalesce (map, lhs, rhs, debug);
	    }
	}
    }

  FOR_EACH_BB (bb)
    {
      /* Treat PHI nodes as copies between the result and each argument.  */
      for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
        {
          size_t i;
	  tree res;

	  phi = gsi_stmt (gsi);
	  res = gimple_phi_result (phi);

	  /* Do not process virtual SSA_NAMES.  */
	  if (virtual_operand_p (res))
	    continue;

	  /* Make sure to only use the same partition for an argument
	     as the result but never the other way around.  */
	  if (SSA_NAME_VAR (res)
	      && !DECL_IGNORED_P (SSA_NAME_VAR (res)))
	    for (i = 0; i < gimple_phi_num_args (phi); i++)
	      {
		tree arg = PHI_ARG_DEF (phi, i);
		if (TREE_CODE (arg) == SSA_NAME)
		  updated |= copy_rename_partition_coalesce (map, res, arg,
							     debug);
	      }
	  /* Else if all arguments are in the same partition try to merge
	     it with the result.  */
	  else
	    {
	      int all_p_same = -1;
	      int p = -1;
	      for (i = 0; i < gimple_phi_num_args (phi); i++)
		{
		  tree arg = PHI_ARG_DEF (phi, i);
		  if (TREE_CODE (arg) != SSA_NAME)
		    {
		      all_p_same = 0;
		      break;
		    }
		  else if (all_p_same == -1)
		    {
		      p = partition_find (map->var_partition,
					  SSA_NAME_VERSION (arg));
		      all_p_same = 1;
		    }
		  else if (all_p_same == 1
			   && p != partition_find (map->var_partition,
						   SSA_NAME_VERSION (arg)))
		    {
		      all_p_same = 0;
		      break;
		    }
		}
	      if (all_p_same == 1)
		updated |= copy_rename_partition_coalesce (map, res,
							   PHI_ARG_DEF (phi, 0),
							   debug);
	    }
        }
    }

  if (debug)
    dump_var_map (debug, map);

  /* Now one more pass to make all elements of a partition share the same
     root variable.  */

  for (x = 1; x < num_ssa_names; x++)
    {
      part_var = partition_to_var (map, x);
      if (!part_var)
        continue;
      var = ssa_name (x);
      if (SSA_NAME_VAR (var) == SSA_NAME_VAR (part_var))
	continue;
      if (debug)
        {
	  fprintf (debug, "Coalesced ");
	  print_generic_expr (debug, var, TDF_SLIM);
	  fprintf (debug, " to ");
	  print_generic_expr (debug, part_var, TDF_SLIM);
	  fprintf (debug, "\n");
	}
      stats.coalesced++;
      replace_ssa_name_symbol (var, SSA_NAME_VAR (part_var));
    }

  statistics_counter_event (cfun, "copies coalesced",
			    stats.coalesced);
  delete_var_map (map);
  return updated ? TODO_remove_unused_locals : 0;
}

static void
tree_nrv (void)
{
  tree result = DECL_RESULT (current_function_decl);
  tree result_type = TREE_TYPE (result);
  tree found = NULL;
  basic_block bb;
  block_stmt_iterator bsi;
  struct nrv_data data;

  /* If this function does not return an aggregate type in memory, then
     there is nothing to do.  */
  if (!aggregate_value_p (result, current_function_decl))
    return;

  /* Look through each block for assignments to the RESULT_DECL.  */
  FOR_EACH_BB (bb)
    {
      for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
	{
	  tree stmt = bsi_stmt (bsi);
	  tree ret_expr;

	  if (TREE_CODE (stmt) == RETURN_EXPR)
	    {
	      /* In a function with an aggregate return value, the
		 gimplifier has changed all non-empty RETURN_EXPRs to
		 return the RESULT_DECL.  */
	      ret_expr = TREE_OPERAND (stmt, 0);
	      if (ret_expr)
		gcc_assert (ret_expr == result);
	    }
	  else if (TREE_CODE (stmt) == MODIFY_EXPR
		   && TREE_OPERAND (stmt, 0) == result)
	    {
	      ret_expr = TREE_OPERAND (stmt, 1);

	      /* Now verify that this return statement uses the same value
		 as any previously encountered return statement.  */
	      if (found != NULL)
		{
		  /* If we found a return statement using a different variable
		     than previous return statements, then we can not perform
		     NRV optimizations.  */
		  if (found != ret_expr)
		    return;
		}
	      else
		found = ret_expr;

	      /* The returned value must be a local automatic variable of the
		 same type and alignment as the function's result.  */
	      if (TREE_CODE (found) != VAR_DECL
		  || TREE_THIS_VOLATILE (found)
		  || DECL_CONTEXT (found) != current_function_decl
		  || TREE_STATIC (found)
		  || TREE_ADDRESSABLE (found)
		  || DECL_ALIGN (found) > DECL_ALIGN (result)
		  || !lang_hooks.types_compatible_p (TREE_TYPE (found), 
						     result_type))
		return;
	    }
	}
    }

  if (!found)
    return;

  /* If dumping details, then note once and only the NRV replacement.  */
  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "NRV Replaced: ");
      print_generic_expr (dump_file, found, dump_flags);
      fprintf (dump_file, "  with: ");
      print_generic_expr (dump_file, result, dump_flags);
      fprintf (dump_file, "\n");
    }

  /* At this point we know that all the return statements return the
     same local which has suitable attributes for NRV.   Copy debugging
     information from FOUND to RESULT.  */
  DECL_NAME (result) = DECL_NAME (found);
  DECL_SOURCE_LOCATION (result) = DECL_SOURCE_LOCATION (found);
  DECL_ABSTRACT_ORIGIN (result) = DECL_ABSTRACT_ORIGIN (found);
  TREE_ADDRESSABLE (result) = TREE_ADDRESSABLE (found);

  /* Now walk through the function changing all references to VAR to be
     RESULT.  */
  data.var = found;
  data.result = result;
  FOR_EACH_BB (bb)
    {
      for (bsi = bsi_start (bb); !bsi_end_p (bsi); )
	{
	  tree *tp = bsi_stmt_ptr (bsi);
	  /* If this is a copy from VAR to RESULT, remove it.  */
	  if (TREE_CODE (*tp) == MODIFY_EXPR
	      && TREE_OPERAND (*tp, 0) == result
	      && TREE_OPERAND (*tp, 1) == found)
	    bsi_remove (&bsi);
//.........这里部分代码省略.........

static bool
ifcombine_iforif (basic_block inner_cond_bb, basic_block outer_cond_bb)
{
  gimple inner_cond, outer_cond;
  tree name1, name2, bits1, bits2;

  inner_cond = last_stmt (inner_cond_bb);
  if (!inner_cond
      || gimple_code (inner_cond) != GIMPLE_COND)
    return false;

  outer_cond = last_stmt (outer_cond_bb);
  if (!outer_cond
      || gimple_code (outer_cond) != GIMPLE_COND)
    return false;

  /* See if we have two bit tests of the same name in both tests.
     In that case remove the outer test and change the inner one to
     test for name & (bits1 | bits2) != 0.  */
  if (recognize_bits_test (inner_cond, &name1, &bits1)
      && recognize_bits_test (outer_cond, &name2, &bits2))
    {
      gimple_stmt_iterator gsi;
      tree t;

      /* Find the common name which is bit-tested.  */
      if (name1 == name2)
	;
      else if (bits1 == bits2)
	{
	  t = name2;
	  name2 = bits2;
	  bits2 = t;
	  t = name1;
	  name1 = bits1;
	  bits1 = t;
	}
      else if (name1 == bits2)
	{
	  t = name2;
	  name2 = bits2;
	  bits2 = t;
	}
      else if (bits1 == name2)
	{
	  t = name1;
	  name1 = bits1;
	  bits1 = t;
	}
      else
	return false;

      /* As we strip non-widening conversions in finding a common
         name that is tested make sure to end up with an integral
	 type for building the bit operations.  */
      if (TYPE_PRECISION (TREE_TYPE (bits1))
	  >= TYPE_PRECISION (TREE_TYPE (bits2)))
	{
	  bits1 = fold_convert (unsigned_type_for (TREE_TYPE (bits1)), bits1);
	  name1 = fold_convert (TREE_TYPE (bits1), name1);
	  bits2 = fold_convert (unsigned_type_for (TREE_TYPE (bits2)), bits2);
	  bits2 = fold_convert (TREE_TYPE (bits1), bits2);
	}
      else
	{
	  bits2 = fold_convert (unsigned_type_for (TREE_TYPE (bits2)), bits2);
	  name1 = fold_convert (TREE_TYPE (bits2), name1);
	  bits1 = fold_convert (unsigned_type_for (TREE_TYPE (bits1)), bits1);
	  bits1 = fold_convert (TREE_TYPE (bits2), bits1);
	}

      /* Do it.  */
      gsi = gsi_for_stmt (inner_cond);
      t = fold_build2 (BIT_IOR_EXPR, TREE_TYPE (name1), bits1, bits2);
      t = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
				    true, GSI_SAME_STMT);
      t = fold_build2 (BIT_AND_EXPR, TREE_TYPE (name1), name1, t);
      t = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
				    true, GSI_SAME_STMT);
      t = fold_build2 (NE_EXPR, boolean_type_node, t,
		       build_int_cst (TREE_TYPE (t), 0));
      gimple_cond_set_condition_from_tree (inner_cond, t);
      update_stmt (inner_cond);

      /* Leave CFG optimization to cfg_cleanup.  */
      gimple_cond_set_condition_from_tree (outer_cond, boolean_false_node);
      update_stmt (outer_cond);

      if (dump_file)
	{
	  fprintf (dump_file, "optimizing bits or bits test to ");
	  print_generic_expr (dump_file, name1, 0);
	  fprintf (dump_file, " & T != 0\nwith temporary T = ");
	  print_generic_expr (dump_file, bits1, 0);
	  fprintf (dump_file, " | ");
	  print_generic_expr (dump_file, bits2, 0);
	  fprintf (dump_file, "\n");
	}

      return true;
//.........这里部分代码省略.........

unsigned HOST_WIDE_INT
compute_builtin_object_size (tree ptr, int object_size_type)
{
  gcc_assert (object_size_type >= 0 && object_size_type <= 3);

  if (! offset_limit)
    init_offset_limit ();

  if (TREE_CODE (ptr) == ADDR_EXPR)
    return addr_object_size (ptr, object_size_type);
  else if (TREE_CODE (ptr) == CALL_EXPR)
    {
      tree arg = pass_through_call (ptr);

      if (arg)
	return compute_builtin_object_size (arg, object_size_type);
      else
	return alloc_object_size (ptr, object_size_type);
    }
  else if (TREE_CODE (ptr) == SSA_NAME
	   && POINTER_TYPE_P (TREE_TYPE (ptr))
	   && object_sizes[object_size_type] != NULL)
    {
      if (!bitmap_bit_p (computed[object_size_type], SSA_NAME_VERSION (ptr)))
	{
	  struct object_size_info osi;
	  bitmap_iterator bi;
	  unsigned int i;

	  if (dump_file)
	    {
	      fprintf (dump_file, "Computing %s %sobject size for ",
		       (object_size_type & 2) ? "minimum" : "maximum",
		       (object_size_type & 1) ? "sub" : "");
	      print_generic_expr (dump_file, ptr, dump_flags);
	      fprintf (dump_file, ":\n");
	    }

	  osi.visited = BITMAP_ALLOC (NULL);
	  osi.reexamine = BITMAP_ALLOC (NULL);
	  osi.object_size_type = object_size_type;
	  osi.depths = NULL;
	  osi.stack = NULL;
	  osi.tos = NULL;

	  /* First pass: walk UD chains, compute object sizes that
	     can be computed.  osi.reexamine bitmap at the end will
	     contain what variables were found in dependency cycles
	     and therefore need to be reexamined.  */
	  osi.pass = 0;
	  osi.changed = false;
	  collect_object_sizes_for (&osi, ptr);

	  /* Second pass: keep recomputing object sizes of variables
	     that need reexamination, until no object sizes are
	     increased or all object sizes are computed.  */
	  if (! bitmap_empty_p (osi.reexamine))
	    {
	      bitmap reexamine = BITMAP_ALLOC (NULL);

	      /* If looking for minimum instead of maximum object size,
		 detect cases where a pointer is increased in a loop.
		 Although even without this detection pass 2 would eventually
		 terminate, it could take a long time.  If a pointer is
		 increasing this way, we need to assume 0 object size.
		 E.g. p = &buf[0]; while (cond) p = p + 4;  */
	      if (object_size_type & 2)
		{
		  osi.depths = xcalloc (num_ssa_names, sizeof (unsigned int));
		  osi.stack = xmalloc (num_ssa_names * sizeof (unsigned int));
		  osi.tos = osi.stack;
		  osi.pass = 1;
		  /* collect_object_sizes_for is changing
		     osi.reexamine bitmap, so iterate over a copy.  */
		  bitmap_copy (reexamine, osi.reexamine);
		  EXECUTE_IF_SET_IN_BITMAP (reexamine, 0, i, bi)
		    if (bitmap_bit_p (osi.reexamine, i))
		      check_for_plus_in_loops (&osi, ssa_name (i));

		  free (osi.depths);
		  osi.depths = NULL;
		  free (osi.stack);
		  osi.stack = NULL;
		  osi.tos = NULL;
		}

	      do
		{
		  osi.pass = 2;
		  osi.changed = false;
		  /* collect_object_sizes_for is changing
		     osi.reexamine bitmap, so iterate over a copy.  */
		  bitmap_copy (reexamine, osi.reexamine);
		  EXECUTE_IF_SET_IN_BITMAP (reexamine, 0, i, bi)
		    if (bitmap_bit_p (osi.reexamine, i))
		      {
			collect_object_sizes_for (&osi, ssa_name (i));
			if (dump_file && (dump_flags & TDF_DETAILS))
			  {
			    fprintf (dump_file, "Reexamining ");
//.........这里部分代码省略.........

static bool
ifcombine_ifandif (basic_block inner_cond_bb, basic_block outer_cond_bb)
{
  gimple_stmt_iterator gsi;
  gimple inner_cond, outer_cond;
  tree name1, name2, bit1, bit2;

  inner_cond = last_stmt (inner_cond_bb);
  if (!inner_cond
      || gimple_code (inner_cond) != GIMPLE_COND)
    return false;

  outer_cond = last_stmt (outer_cond_bb);
  if (!outer_cond
      || gimple_code (outer_cond) != GIMPLE_COND)
    return false;

  /* See if we test a single bit of the same name in both tests.  In
     that case remove the outer test, merging both else edges,
     and change the inner one to test for
     name & (bit1 | bit2) == (bit1 | bit2).  */
  if (recognize_single_bit_test (inner_cond, &name1, &bit1)
      && recognize_single_bit_test (outer_cond, &name2, &bit2)
      && name1 == name2)
    {
      tree t, t2;

      /* Do it.  */
      gsi = gsi_for_stmt (inner_cond);
      t = fold_build2 (LSHIFT_EXPR, TREE_TYPE (name1),
		       build_int_cst (TREE_TYPE (name1), 1), bit1);
      t2 = fold_build2 (LSHIFT_EXPR, TREE_TYPE (name1),
		        build_int_cst (TREE_TYPE (name1), 1), bit2);
      t = fold_build2 (BIT_IOR_EXPR, TREE_TYPE (name1), t, t2);
      t = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
				    true, GSI_SAME_STMT);
      t2 = fold_build2 (BIT_AND_EXPR, TREE_TYPE (name1), name1, t);
      t2 = force_gimple_operand_gsi (&gsi, t2, true, NULL_TREE,
				     true, GSI_SAME_STMT);
      t = fold_build2 (EQ_EXPR, boolean_type_node, t2, t);
      gimple_cond_set_condition_from_tree (inner_cond, t);
      update_stmt (inner_cond);

      /* Leave CFG optimization to cfg_cleanup.  */
      gimple_cond_set_condition_from_tree (outer_cond, boolean_true_node);
      update_stmt (outer_cond);

      if (dump_file)
	{
	  fprintf (dump_file, "optimizing double bit test to ");
	  print_generic_expr (dump_file, name1, 0);
	  fprintf (dump_file, " & T == T\nwith temporary T = (1 << ");
	  print_generic_expr (dump_file, bit1, 0);
	  fprintf (dump_file, ") | (1 << ");
	  print_generic_expr (dump_file, bit2, 0);
	  fprintf (dump_file, ")\n");
	}

      return true;
    }

  return false;
}

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;
}

static bool
copy_rename_partition_coalesce (var_map map, tree var1, tree var2, FILE *debug)
{
  int p1, p2, p3;
  tree root1, root2;
  tree rep1, rep2;
  bool ign1, ign2, abnorm;

  gcc_assert (TREE_CODE (var1) == SSA_NAME);
  gcc_assert (TREE_CODE (var2) == SSA_NAME);

  register_ssa_partition (map, var1);
  register_ssa_partition (map, var2);

  p1 = partition_find (map->var_partition, SSA_NAME_VERSION (var1));
  p2 = partition_find (map->var_partition, SSA_NAME_VERSION (var2));

  if (debug)
    {
      fprintf (debug, "Try : ");
      print_generic_expr (debug, var1, TDF_SLIM);
      fprintf (debug, "(P%d) & ", p1);
      print_generic_expr (debug, var2, TDF_SLIM);
      fprintf (debug, "(P%d)", p2);
    }

  gcc_assert (p1 != NO_PARTITION);
  gcc_assert (p2 != NO_PARTITION);

  rep1 = partition_to_var (map, p1);
  rep2 = partition_to_var (map, p2);
  root1 = SSA_NAME_VAR (rep1);
  root2 = SSA_NAME_VAR (rep2);

  if (p1 == p2)
    {
      if (debug)
	fprintf (debug, " : Already coalesced.\n");
      return false;
    }

  /* Don't coalesce if one of the variables occurs in an abnormal PHI.  */
  abnorm = (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rep1)
	    || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rep2));
  if (abnorm)
    {
      if (debug)
	fprintf (debug, " : Abnormal PHI barrier.  No coalesce.\n");
      return false;
    }

  /* Partitions already have the same root, simply merge them.  */
  if (root1 == root2)
    {
      p1 = partition_union (map->var_partition, p1, p2);
      if (debug)
	fprintf (debug, " : Same root, coalesced --> P%d.\n", p1);
      return false;
    }

  /* Never attempt to coalesce 2 difference parameters.  */
  if (TREE_CODE (root1) == PARM_DECL && TREE_CODE (root2) == PARM_DECL)
    {
      if (debug)
        fprintf (debug, " : 2 different PARM_DECLS. No coalesce.\n");
      return false;
    }

  if ((TREE_CODE (root1) == RESULT_DECL) != (TREE_CODE (root2) == RESULT_DECL))
    {
      if (debug)
        fprintf (debug, " : One root a RESULT_DECL. No coalesce.\n");
      return false;
    }

  ign1 = TREE_CODE (root1) == VAR_DECL && DECL_IGNORED_P (root1);
  ign2 = TREE_CODE (root2) == VAR_DECL && DECL_IGNORED_P (root2);

  /* Never attempt to coalesce 2 user variables unless one is an inline
     variable.  */
  if (!ign1 && !ign2)
    {
      if (DECL_FROM_INLINE (root2))
        ign2 = true;
      else if (DECL_FROM_INLINE (root1))
	ign1 = true;
      else
	{
	  if (debug)
	    fprintf (debug, " : 2 different USER vars. No coalesce.\n");
	  return false;
	}
    }

  /* If both values have default defs, we can't coalesce.  If only one has a
     tag, make sure that variable is the new root partition.  */
  if (gimple_default_def (cfun, root1))
    {
      if (gimple_default_def (cfun, root2))
	{
//.........这里部分代码省略.........

static unsigned int
rename_ssa_copies (void)
{
  var_map map;
  basic_block bb;
  gimple_stmt_iterator gsi;
  tree var, part_var;
  gimple stmt, phi;
  unsigned x;
  FILE *debug;
  bool updated = false;

  if (dump_file && (dump_flags & TDF_DETAILS))
    debug = dump_file;
  else
    debug = NULL;

  map = init_var_map (num_ssa_names);

  FOR_EACH_BB (bb)
    {
      /* Scan for real copies.  */
      for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
	{
	  stmt = gsi_stmt (gsi);
	  if (gimple_assign_ssa_name_copy_p (stmt))
	    {
	      tree lhs = gimple_assign_lhs (stmt);
	      tree rh