1 /* Adjust alignment for local variable.
2    Copyright (C) 2020-2022 Free Software Foundation, Inc.
3    Contributed by Kito Cheng <kito.cheng@sifive.com>
4 
5 This file is part of GCC.
6 
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
11 
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15 for more details.
16 
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3.  If not see
19 <http://www.gnu.org/licenses/>.  */
20 
21 #include "config.h"
22 #include "system.h"
23 #include "coretypes.h"
24 #include "backend.h"
25 #include "target.h"
26 #include "tree.h"
27 #include "tree-pass.h"
28 #include "memmodel.h"
29 #include "tm_p.h"
30 
31 namespace {
32 
33 const pass_data pass_data_adjust_alignment =
34 {
35   GIMPLE_PASS, /* type */
36   "adjust_alignment", /* name */
37   OPTGROUP_NONE, /* optinfo_flags */
38   TV_NONE, /* tv_id */
39   0, /* properties_required */
40   0, /* properties_provided */
41   0, /* properties_destroyed */
42   0, /* todo_flags_start */
43   0, /* todo_flags_finish */
44 };
45 
46 class pass_adjust_alignment : public gimple_opt_pass
47 {
48 public:
pass_adjust_alignment(gcc::context * ctxt)49   pass_adjust_alignment (gcc::context *ctxt)
50     : gimple_opt_pass (pass_data_adjust_alignment, ctxt)
51   {}
52 
53   virtual unsigned int execute (function *);
54 }; // class pass_adjust_alignment
55 
56 } // anon namespace
57 
58 /* Entry point to adjust_alignment pass.  */
59 unsigned int
execute(function * fun)60 pass_adjust_alignment::execute (function *fun)
61 {
62   size_t i;
63   tree var;
64 
65   FOR_EACH_LOCAL_DECL (fun, i, var)
66     {
67       /* Don't adjust aligment for static local var and hard register var.  */
68       if (is_global_var (var) || DECL_HARD_REGISTER (var))
69 	continue;
70 
71       unsigned align = LOCAL_DECL_ALIGNMENT (var);
72 
73       /* Make sure alignment only increase.  */
74       gcc_assert (align >= DECL_ALIGN (var));
75 
76       SET_DECL_ALIGN (var, align);
77     }
78   return 0;
79 }
80 
81 gimple_opt_pass *
make_pass_adjust_alignment(gcc::context * ctxt)82 make_pass_adjust_alignment (gcc::context *ctxt)
83 {
84   return new pass_adjust_alignment (ctxt);
85 }
86