1 /* Header file for the GIMPLE fold_using_range interface.
2    Copyright (C) 2019-2021 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_FOLD_H
23 #define GCC_GIMPLE_RANGE_FOLD_H
24 
25 // This file is the main include point for gimple range folding.
26 // These routines will fold stmt S into the result irange R.
27 // Any ssa_names on the stmt will be calculated using the range_query
28 // parameter via a call to range_of_expr.
29 // If no range_query is provided, current global range info will be used.
30 // The second variation specifies an edge, and stmt S is recalculated as if
31 // it appeared on that edge.
32 
33 // Fold stmt S into range R using range query Q.
34 bool fold_range (irange &r, gimple *s, range_query *q = NULL);
35 // Recalculate stmt S into R using range query Q as if it were on edge ON_EDGE.
36 bool fold_range (irange &r, gimple *s, edge on_edge, range_query *q = NULL);
37 
38 // These routines the operands to be specified when manually folding.
39 // Any excess queries will be drawn from the current range_query.
40 bool fold_range (irange &r, gimple *s, irange &r1);
41 bool fold_range (irange &r, gimple *s, irange &r1, irange &r2);
42 bool fold_range (irange &r, gimple *s, unsigned num_elements, irange *vector);
43 
44 // Return the range_operator pointer for this statement.  This routine
45 // can also be used to gate whether a routine is range-ops enabled.
46 
47 static inline range_operator *
gimple_range_handler(const gimple * s)48 gimple_range_handler (const gimple *s)
49 {
50   if (const gassign *ass = dyn_cast<const gassign *> (s))
51     return range_op_handler (gimple_assign_rhs_code (ass),
52 			     TREE_TYPE (gimple_assign_lhs (ass)));
53   if (const gcond *cond = dyn_cast<const gcond *> (s))
54     return range_op_handler (gimple_cond_code (cond),
55 			     TREE_TYPE (gimple_cond_lhs (cond)));
56   return NULL;
57 }
58 
59 // Return the type of range which statement S calculates.  If the type is
60 // unsupported or no type can be determined, return NULL_TREE.
61 
62 static inline tree
gimple_range_type(const gimple * s)63 gimple_range_type (const gimple *s)
64 {
65   tree lhs = gimple_get_lhs (s);
66   tree type = NULL_TREE;
67   if (lhs)
68     type = TREE_TYPE (lhs);
69   else
70     {
71       enum gimple_code code = gimple_code (s);
72       if (code == GIMPLE_COND)
73 	type = boolean_type_node;
74       else if (code == GIMPLE_PHI)
75 	type = TREE_TYPE (gimple_phi_result (s));
76       else if (code == GIMPLE_CALL)
77 	{
78 	  type = gimple_call_fntype (s);
79 	  // If it has a type, get the return type.
80 	  if (type)
81 	    type = TREE_TYPE (type);
82 	}
83     }
84   if (irange::supports_type_p (type))
85     return type;
86   return NULL_TREE;
87 }
88 
89 // Return EXP if it is an SSA_NAME with a type supported by gimple ranges.
90 
91 static inline tree
gimple_range_ssa_p(tree exp)92 gimple_range_ssa_p (tree exp)
93 {
94   if (exp && TREE_CODE (exp) == SSA_NAME &&
95       !SSA_NAME_IS_VIRTUAL_OPERAND (exp) &&
96       !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (exp) &&
97       irange::supports_type_p (TREE_TYPE (exp)))
98     return exp;
99   return NULL_TREE;
100 }
101 
102 // Return true if TYPE1 and TYPE2 are compatible range types.
103 
104 static inline bool
range_compatible_p(tree type1,tree type2)105 range_compatible_p (tree type1, tree type2)
106 {
107   // types_compatible_p requires conversion in both directions to be useless.
108   // GIMPLE only requires a cast one way in order to be compatible.
109   // Ranges really only need the sign and precision to be the same.
110   return (TYPE_PRECISION (type1) == TYPE_PRECISION (type2)
111 	  && TYPE_SIGN (type1) == TYPE_SIGN (type2));
112 }
113 
114 
115 // Source of all operands for fold_using_range and gori_compute.
116 // It abstracts out the source of an operand so it can come from a stmt or
117 // and edge or anywhere a derived class of fur_source wants.
118 // The default simply picks up ranges from the current range_query.
119 
120 class fur_source
121 {
122 public:
123   fur_source (range_query *q = NULL);
query()124   inline range_query *query () { return m_query; }
gori()125   inline class gori_compute *gori () { return m_gori; };
126   virtual bool get_operand (irange &r, tree expr);
127   virtual bool get_phi_operand (irange &r, tree expr, edge e);
128   virtual relation_kind query_relation (tree op1, tree op2);
129   virtual void register_relation (gimple *stmt, relation_kind k, tree op1,
130 				  tree op2);
131   virtual void register_relation (edge e, relation_kind k, tree op1,
132 				  tree op2);
133   void register_outgoing_edges (gcond *, irange &lhs_range, edge e0, edge e1);
134 protected:
135   range_query *m_query;
136   gori_compute *m_gori;
137 };
138 
139 // fur_stmt is the specification for drawing an operand from range_query Q
140 // via a range_of_Expr call on stmt S.
141 
142 class fur_stmt : public fur_source
143 {
144 public:
145   fur_stmt (gimple *s, range_query *q = NULL);
146   virtual bool get_operand (irange &r, tree expr) OVERRIDE;
147   virtual bool get_phi_operand (irange &r, tree expr, edge e) OVERRIDE;
148   virtual relation_kind query_relation (tree op1, tree op2) OVERRIDE;
149 private:
150   gimple *m_stmt;
151 };
152 
153 // This version of fur_source will pick a range from a stmt, and also register
154 // dependencies via a gori_compute object.  This is mostly an internal API.
155 
156 class fur_depend : public fur_stmt
157 {
158 public:
159   fur_depend (gimple *s, gori_compute *gori, range_query *q = NULL);
160   virtual void register_relation (gimple *stmt, relation_kind k, tree op1,
161 				  tree op2) OVERRIDE;
162   virtual void register_relation (edge e, relation_kind k, tree op1,
163 				  tree op2) OVERRIDE;
164 protected:
165   relation_oracle *m_oracle;
166 };
167 
168 extern tree gimple_range_operand1 (const gimple *s);
169 extern tree gimple_range_operand2 (const gimple *s);
170 
171 // This class uses ranges to fold a gimple statement producinf a range for
172 // the LHS.  The source of all operands is supplied via the fur_source class
173 // which provides a range_query as well as a source location and any other
174 // required information.
175 
176 class fold_using_range
177 {
178 public:
179   bool fold_stmt (irange &r, gimple *s, class fur_source &src,
180 		  tree name = NULL_TREE);
181 protected:
182   bool range_of_range_op (irange &r, gimple *s, fur_source &src);
183   bool range_of_call (irange &r, gcall *call, fur_source &src);
184   bool range_of_cond_expr (irange &r, gassign* cond, fur_source &src);
185   bool range_of_address (irange &r, gimple *s, fur_source &src);
186   bool range_of_builtin_call (irange &r, gcall *call, fur_source &src);
187   void range_of_builtin_ubsan_call (irange &r, gcall *call, tree_code code,
188 				    fur_source &src);
189   bool range_of_phi (irange &r, gphi *phi, fur_source &src);
190   void range_of_ssa_name_with_loop_info (irange &, tree, class loop *, gphi *,
191 					 fur_source &src);
192   void relation_fold_and_or (irange& lhs_range, gimple *s, fur_source &src);
193 };
194 #endif // GCC_GIMPLE_RANGE_FOLD_H
195