1 /* Header file for gimple range GORI structures.
2 Copyright (C) 2017-2023 Free Software Foundation, Inc.
3 Contributed by Andrew MacLeod <amacleod@redhat.com>
4 and Aldy Hernandez <aldyh@redhat.com>.
5
6 This file is part of GCC.
7
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
12
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
21
22 #ifndef GCC_GIMPLE_RANGE_GORI_H
23 #define GCC_GIMPLE_RANGE_GORI_H
24
25 // RANGE_DEF_CHAIN is used to determine which SSA names in a block can
26 // have range information calculated for them, and what the
27 // dependencies on each other are.
28
29 class range_def_chain
30 {
31 public:
32 range_def_chain ();
33 ~range_def_chain ();
34 tree depend1 (tree name) const;
35 tree depend2 (tree name) const;
36 bool in_chain_p (tree name, tree def);
37 bool chain_import_p (tree name, tree import);
38 void register_dependency (tree name, tree ssa1, basic_block bb = NULL);
39 void dump (FILE *f, basic_block bb, const char *prefix = NULL);
40 protected:
41 bool has_def_chain (tree name);
42 bool def_chain_in_bitmap_p (tree name, bitmap b);
43 void add_def_chain_to_bitmap (bitmap b, tree name);
44 bitmap get_def_chain (tree name);
45 bitmap get_imports (tree name);
46 bitmap_obstack m_bitmaps;
47 private:
48 struct rdc {
49 tree ssa1; // First direct dependency
50 tree ssa2; // Second direct dependency
51 bitmap bm; // All dependencies
52 bitmap m_import;
53 };
54 vec<rdc> m_def_chain; // SSA_NAME : def chain components.
55 void set_import (struct rdc &data, tree imp, bitmap b);
56 int m_logical_depth;
57 };
58
59 // Return the first direct dependency for NAME, if there is one.
60 // Direct dependencies are those which occur on the definition statement.
61 // Only the first 2 such names are cached.
62
63 inline tree
64 range_def_chain::depend1 (tree name) const
65 {
66 unsigned v = SSA_NAME_VERSION (name);
67 if (v >= m_def_chain.length ())
68 return NULL_TREE;
69 return m_def_chain[v].ssa1;
70 }
71
72 // Return the second direct dependency for NAME, if there is one.
73
74 inline tree
75 range_def_chain::depend2 (tree name) const
76 {
77 unsigned v = SSA_NAME_VERSION (name);
78 if (v >= m_def_chain.length ())
79 return NULL_TREE;
80 return m_def_chain[v].ssa2;
81 }
82
83 // GORI_MAP is used to accumulate what SSA names in a block can
84 // generate range information, and provides tools for the block ranger
85 // to enable it to efficiently calculate these ranges.
86
87 class gori_map : public range_def_chain
88 {
89 public:
90 gori_map ();
91 ~gori_map ();
92
93 bool is_export_p (tree name, basic_block bb = NULL);
94 bool is_import_p (tree name, basic_block bb);
95 bitmap exports (basic_block bb);
96 bitmap imports (basic_block bb);
97 void set_range_invariant (tree name, bool invariant = true);
98
99 void dump (FILE *f);
100 void dump (FILE *f, basic_block bb, bool verbose = true);
101 private:
102 vec<bitmap> m_outgoing; // BB: Outgoing ranges calculable on edges
103 vec<bitmap> m_incoming; // BB: Incoming ranges which can affect exports.
104 bitmap m_maybe_variant; // Names which might have outgoing ranges.
105 void maybe_add_gori (tree name, basic_block bb);
106 void calculate_gori (basic_block bb);
107 };
108
109
110 // This class is used to determine which SSA_NAMES can have ranges
111 // calculated for them on outgoing edges from basic blocks. This represents
112 // ONLY the effect of the basic block edge->src on a range.
113 //
114 // There are 2 primary entry points:
115 //
116 // has_edge_range_p (tree name, edge e)
117 // returns true if the outgoing edge *may* be able to produce range
118 // information for ssa_name NAME on edge E.
119 // FALSE is returned if this edge does not affect the range of NAME.
120 // if no edge is specified, return TRUE if name may have a value calculated
121 // on *ANY* edge that has been seen. FALSE indicates that the global value
122 // is applicable everywhere that has been processed.
123 //
124 // outgoing_edge_range_p (vrange &range, edge e, tree name)
125 // Actually does the calculation of RANGE for name on E
126 // This represents application of whatever static range effect edge E
127 // may have on NAME, not any cumulative effect.
128
129 // There are also some internal APIs
130 //
131 // ssa_range_in_bb () is an internal routine which is used to start any
132 // calculation chain using SSA_NAMES which come from outside the block. ie
133 // a_2 = b_4 - 8
134 // if (a_2 < 30)
135 // on the true edge, a_2 is known to be [0, 29]
136 // b_4 can be calculated as [8, 37]
137 // during this calculation, b_4 is considered an "import" and ssa_range_in_bb
138 // is queried for a starting range which is used in the calculation.
139 // A default value of VARYING provides the raw static info for the edge.
140 //
141 // If there is any known range for b_4 coming into this block, it can refine
142 // the results. This allows for cascading results to be propagated.
143 // if b_4 is [100, 200] on entry to the block, feeds into the calculation
144 // of a_2 = [92, 192], and finally on the true edge the range would be
145 // an empty range [] because it is not possible for the true edge to be taken.
146 //
147 // expr_range_in_bb is simply a wrapper which calls ssa_range_in_bb for
148 // SSA_NAMES and otherwise simply calculates the range of the expression.
149 //
150 // The constructor takes a flag value to use on edges to check for the
151 // NON_EXECUTABLE_EDGE property. The zero default means no flag is checked.
152 // All value requests from NON_EXECUTABLE_EDGE edges are returned UNDEFINED.
153 //
154 // The remaining routines are internal use only.
155
156 class value_relation;
157
158 class gori_compute : public gori_map
159 {
160 public:
161 gori_compute (int not_executable_flag = 0);
162 bool outgoing_edge_range_p (vrange &r, edge e, tree name, range_query &q);
163 bool condexpr_adjust (vrange &r1, vrange &r2, gimple *s, tree cond, tree op1,
164 tree op2, fur_source &src);
165 bool has_edge_range_p (tree name, basic_block bb = NULL);
166 bool has_edge_range_p (tree name, edge e);
167 void dump (FILE *f);
168 bool compute_operand_range (vrange &r, gimple *stmt, const vrange &lhs,
169 tree name, class fur_source &src,
170 value_relation *rel = NULL);
171 private:
172 bool refine_using_relation (tree op1, vrange &op1_range,
173 tree op2, vrange &op2_range,
174 fur_source &src, relation_kind k);
175 bool may_recompute_p (tree name, edge e, int depth = -1);
176 bool may_recompute_p (tree name, basic_block bb = NULL, int depth = -1);
177 bool compute_operand_range_switch (vrange &r, gswitch *s, const vrange &lhs,
178 tree name, fur_source &src);
179 bool compute_operand1_range (vrange &r, gimple_range_op_handler &handler,
180 const vrange &lhs, tree name, fur_source &src,
181 value_relation *rel = NULL);
182 bool compute_operand2_range (vrange &r, gimple_range_op_handler &handler,
183 const vrange &lhs, tree name, fur_source &src,
184 value_relation *rel = NULL);
185 bool compute_operand1_and_operand2_range (vrange &r,
186 gimple_range_op_handler &handler,
187 const vrange &lhs, tree name,
188 fur_source &src,
189 value_relation *rel = NULL);
190 void compute_logical_operands (vrange &true_range, vrange &false_range,
191 gimple_range_op_handler &handler,
192 const irange &lhs, tree name, fur_source &src,
193 tree op, bool op_in_chain);
194 bool logical_combine (vrange &r, enum tree_code code, const irange &lhs,
195 const vrange &op1_true, const vrange &op1_false,
196 const vrange &op2_true, const vrange &op2_false);
197 int_range<2> m_bool_zero; // Boolean false cached.
198 int_range<2> m_bool_one; // Boolean true cached.
199
200 gimple_outgoing_range outgoing; // Edge values for COND_EXPR & SWITCH_EXPR.
201 range_tracer tracer;
202 int m_not_executable_flag;
203 };
204
205 // For each name that is an import into BB's exports..
206 #define FOR_EACH_GORI_IMPORT_NAME(gori, bb, name) \
207 for (gori_export_iterator iter ((gori).imports ((bb))); \
208 ((name) = iter.get_name ()); \
209 iter.next ())
210
211 // For each name possibly exported from block BB.
212 #define FOR_EACH_GORI_EXPORT_NAME(gori, bb, name) \
213 for (gori_export_iterator iter ((gori).exports ((bb))); \
214 ((name) = iter.get_name ()); \
215 iter.next ())
216
217 // Used to assist with iterating over the GORI export list in various ways
218 class gori_export_iterator {
219 public:
220 gori_export_iterator (bitmap b);
221 void next ();
222 tree get_name ();
223 protected:
224 bitmap bm;
225 bitmap_iterator bi;
226 unsigned y;
227 };
228
229 #endif // GCC_GIMPLE_RANGE_GORI_H