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1 : : /* Header file for gimple range inference.
2 : : Copyright (C) 2022-2024 Free Software Foundation, Inc.
3 : : Contributed by Andrew MacLeod <amacleod@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 : : #ifndef GCC_GIMPLE_RANGE_SIDE_H
22 : : #define GCC_GIMPLE_RANGE_SIDE_H
23 : :
24 : : // Inferred ranges are ranges which are applied to use operands as a by product
25 : : // of executing an operation.
26 : :
27 : : // This class manages an on-demand summary of inferred ranges for a statement.
28 : : // It can be instantiated as required and provides a list of inferred ranges.
29 : : // New inferred ranges should be added in the constructor of this class.
30 : : //
31 : : // There are 2 main instantiations.
32 : : // gimple_range_infer (gimple *s, range_query *q, bool use_range_ops)
33 : : // S is the statement being queried.
34 : : // Q is a range-query object which is used to resolve any ranges that
35 : : // might be required. This defaults to NULL which maps to the
36 : : // global_range_query, which is what most passes will want.
37 : : // Ranger internally will pass the cache's range-query which is a
38 : : // read-only query and prevents any additional lookup.
39 : : // USE_RANGEOPS is a boolean flag which defaults to false. if TRUE,
40 : : // range-ops is invoked to see if any additional side effects are seen
41 : : // based on the stmt. ie .x = y * 2 will reigster a side effect for Y
42 : : // which is [-INF/2 , +INF/2]. It is not on by default because it
43 : : // is a relatively expensive operation to do on every statement, and
44 : : // ranger will already incorporate that range for Y via GORI most of the
45 : : // time that it matters. Individual passes may have use for it however.
46 : : // PR 113879 is an example where this can be of use.
47 : : //
48 : : // gimple_range_infer (tree name, vrange &r)
49 : : // This instantiation simply create an inferred range record directly.
50 : : // NAME is the SSA_NAME to create the record for
51 : : // R is the range for NAME.
52 : : //
53 : : // Once a gimple_infer_range record has been created, the API is simple:
54 : : // num () - The number of inferred ranges in this record.
55 : : // name (i) - The i'th SSA_NAME in this record.
56 : : // range (i) - The range of the i'th SSA_NAME.
57 : :
58 : 3299227415 : class gimple_infer_range
59 : : {
60 : : public:
61 : : gimple_infer_range (gimple *s, range_query *q = NULL,
62 : : bool use_rangeops = false);
63 : : gimple_infer_range (tree name, vrange &r);
64 : 365787535 : inline unsigned num () const { return num_args; }
65 : 36493309 : inline tree name (unsigned index) const
66 : 36493309 : { gcc_checking_assert (index < num_args); return m_names[index]; }
67 : 39841612 : inline const vrange& range (unsigned index) const
68 : 39841612 : { gcc_checking_assert (index < num_args); return m_ranges[index]; }
69 : : private:
70 : : void add_range (tree name, vrange &range);
71 : : void add_nonzero (tree name);
72 : : void check_assume_func (gcall *call);
73 : : unsigned num_args;
74 : : static const int size_limit = 10;
75 : : tree m_names[size_limit];
76 : : value_range m_ranges[size_limit];
77 : : inline void bump_index () { if (num_args < size_limit - 1) num_args++; }
78 : : friend class non_null_wrapper;
79 : : };
80 : :
81 : : // This is the basic infer oracle API. Default functionaility does nothing.
82 : :
83 : : class infer_range_oracle
84 : : {
85 : : public:
86 : 24573651 : infer_range_oracle () { }
87 : 25131775 : virtual ~infer_range_oracle () { }
88 : 0 : virtual void add_ranges (gimple *, gimple_infer_range &) { }
89 : 0 : virtual bool has_range_p (basic_block, tree = NULL_TREE) { return false; }
90 : 0 : virtual bool maybe_adjust_range (vrange &, tree, basic_block)
91 : 0 : { return false; }
92 : : };
93 : :
94 : : // This class manages a list of inferred ranges for each basic block.
95 : : // As inferences are made, they can be registered to a block and later
96 : : // queried via a DOM search.
97 : : // When DO_SEARCH is TRUE, immediate uses chains are followed the first time
98 : : // a name is referenced and block populated if there are any inferred ranges.
99 : : // range_query Q is the range_query to use for any range lookups. It defaults
100 : : // to NULL which maps to the global_range_query. This is what most passes
101 : : // will want to use. Ranger invokes it with the cache's internal query which
102 : : // can provide better ranges during a DOM walk.
103 : : //
104 : : // add_ranges is used to add inferred range IR assocaited with stmt S.
105 : : // has_range_p is used to check if NAME has an inferred range in block BB.
106 : : // maybe_adjust_range will adjust the range R to incorporate any inferred
107 : : // range NAME may have in block BB. If there are on inferred ranges in
108 : : // block BB, then R will be unchanged, otherwise the ranges are intersected.
109 : :
110 : : class infer_range_manager : public infer_range_oracle
111 : : {
112 : : public:
113 : : infer_range_manager (bool do_search, range_query *q = NULL);
114 : : virtual ~infer_range_manager ();
115 : : virtual void add_ranges (gimple *s, gimple_infer_range &ir);
116 : : virtual bool has_range_p (basic_block bb, tree name = NULL_TREE);
117 : : virtual bool maybe_adjust_range (vrange &r, tree name, basic_block bb);
118 : : private:
119 : : void add_range (tree name, gimple *s, const vrange &r);
120 : : void add_nonzero (tree name, gimple *s);
121 : : class exit_range_head
122 : : {
123 : : public:
124 : : bitmap m_names; // list of names with an outgoing range.
125 : : class exit_range *head;
126 : : int m_num_ranges;
127 : : exit_range *find_ptr (tree name);
128 : : };
129 : : void register_all_uses (tree name);
130 : : vec <exit_range_head> m_on_exit;
131 : : const vrange &get_nonzero (tree name);
132 : : vec <vrange *> m_nonzero;
133 : : bitmap m_seen;
134 : : bitmap_obstack m_bitmaps;
135 : : struct obstack m_list_obstack;
136 : : class vrange_allocator *m_range_allocator;
137 : : range_query *m_query;
138 : : };
139 : : #endif // GCC_GIMPLE_RANGE_SIDE_H
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