1 | /* Lower and optimize address expressions. |
2 | Copyright (C) 2015-2023 Free Software Foundation, Inc. |
3 | Contributed by Marek Polacek <polacek@redhat.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 "alias.h" |
25 | #include "predict.h" |
26 | #include "tm.h" |
27 | #include "function.h" |
28 | #include "dominance.h" |
29 | #include "cfg.h" |
30 | #include "basic-block.h" |
31 | #include "tree-ssa-alias.h" |
32 | #include "symtab.h" |
33 | #include "tree.h" |
34 | #include "stringpool.h" |
35 | #include "tree-vrp.h" |
36 | #include "tree-ssanames.h" |
37 | #include "fold-const.h" |
38 | #include "gimple-expr.h" |
39 | #include "gimple.h" |
40 | #include "gimplify.h" |
41 | #include "gimple-iterator.h" |
42 | #include "gimplify-me.h" |
43 | #include "tree-pass.h" |
44 | |
45 | |
46 | namespace { |
47 | |
48 | const pass_data pass_data_laddress = |
49 | { |
50 | .type: GIMPLE_PASS, /* type */ |
51 | .name: "laddress" , /* name */ |
52 | .optinfo_flags: OPTGROUP_NONE, /* optinfo_flags */ |
53 | .tv_id: TV_GIMPLE_LADDRESS, /* tv_id */ |
54 | .properties_required: ( PROP_cfg | PROP_ssa ), /* properties_required */ |
55 | .properties_provided: 0, /* properties_provided */ |
56 | .properties_destroyed: 0, /* properties_destroyed */ |
57 | .todo_flags_start: 0, /* todo_flags_start */ |
58 | .todo_flags_finish: 0, /* todo_flags_finish */ |
59 | }; |
60 | |
61 | class pass_laddress : public gimple_opt_pass |
62 | { |
63 | public: |
64 | pass_laddress (gcc::context *ctxt) |
65 | : gimple_opt_pass (pass_data_laddress, ctxt) |
66 | {} |
67 | |
68 | /* opt_pass methods: */ |
69 | opt_pass * clone () final override { return new pass_laddress (m_ctxt); } |
70 | bool gate (function *) final override { return optimize != 0; } |
71 | unsigned int execute (function *) final override; |
72 | |
73 | }; // class pass_laddress |
74 | |
75 | unsigned int |
76 | pass_laddress::execute (function *fun) |
77 | { |
78 | basic_block bb; |
79 | |
80 | FOR_EACH_BB_FN (bb, fun) |
81 | { |
82 | for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (i: gsi);) |
83 | { |
84 | gimple *stmt = gsi_stmt (i: gsi); |
85 | if (!is_gimple_assign (gs: stmt) |
86 | || gimple_assign_rhs_code (gs: stmt) != ADDR_EXPR |
87 | || is_gimple_invariant_address (gimple_assign_rhs1 (gs: stmt))) |
88 | { |
89 | gsi_next (i: &gsi); |
90 | continue; |
91 | } |
92 | |
93 | /* Lower ADDR_EXPR assignments: |
94 | _4 = &b[i_9]; |
95 | into |
96 | _1 = (sizetype) i_9; |
97 | _7 = _1 * 4; |
98 | _4 = &b + _7; |
99 | This ought to aid the vectorizer and expose CSE opportunities. |
100 | */ |
101 | |
102 | tree expr = gimple_assign_rhs1 (gs: stmt); |
103 | poly_int64 bitsize, bitpos; |
104 | tree base, offset; |
105 | machine_mode mode; |
106 | int volatilep = 0, reversep, unsignedp = 0; |
107 | base = get_inner_reference (TREE_OPERAND (expr, 0), &bitsize, |
108 | &bitpos, &offset, &mode, &unsignedp, |
109 | &reversep, &volatilep); |
110 | gcc_assert (base != NULL_TREE); |
111 | poly_int64 bytepos = exact_div (a: bitpos, BITS_PER_UNIT); |
112 | if (offset != NULL_TREE) |
113 | { |
114 | if (maybe_ne (a: bytepos, b: 0)) |
115 | offset = size_binop (PLUS_EXPR, offset, size_int (bytepos)); |
116 | offset = force_gimple_operand_gsi (&gsi, offset, true, NULL, |
117 | true, GSI_SAME_STMT); |
118 | base = build_fold_addr_expr (base); |
119 | base = force_gimple_operand_gsi (&gsi, base, true, NULL, |
120 | true, GSI_SAME_STMT); |
121 | gimple *g = gimple_build_assign (gimple_assign_lhs (gs: stmt), |
122 | POINTER_PLUS_EXPR, base, offset); |
123 | gsi_replace (&gsi, g, false); |
124 | } |
125 | gsi_next (i: &gsi); |
126 | } |
127 | } |
128 | |
129 | return 0; |
130 | } |
131 | |
132 | } // anon namespace |
133 | |
134 | gimple_opt_pass * |
135 | make_pass_laddress (gcc::context *ctxt) |
136 | { |
137 | return new pass_laddress (ctxt); |
138 | } |
139 | |