1 /* Header file for routines that straddle the border between GIMPLE and
2    SSA in gimple.
3    Copyright (C) 2009-2020 Free Software Foundation, Inc.
4 
5 This file is part of GCC.
6 
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
10 any later version.
11 
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 GNU General Public License 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_SSA_H
22 #define GCC_GIMPLE_SSA_H
23 
24 #include "tree-ssa-operands.h"
25 
26 /* This structure is used to map a gimple statement to a label,
27    or list of labels to represent transaction restart.  */
28 
29 struct GTY((for_user)) tm_restart_node {
30   gimple *stmt;
31   tree label_or_list;
32 };
33 
34 /* Hasher for tm_restart_node.  */
35 
36 struct tm_restart_hasher : ggc_ptr_hash<tm_restart_node>
37 {
hashtm_restart_hasher38   static hashval_t hash (tm_restart_node *n) { return htab_hash_pointer (n); }
39 
40   static bool
equaltm_restart_hasher41   equal (tm_restart_node *a, tm_restart_node *b)
42   {
43     return a == b;
44   }
45 };
46 
47 extern void gt_ggc_mx (gimple *&);
48 extern void gt_pch_nx (gimple *&);
49 
50 struct ssa_name_hasher : ggc_ptr_hash<tree_node>
51 {
52   /* Hash a tree in a uid_decl_map.  */
53 
54   static hashval_t
hashssa_name_hasher55   hash (tree item)
56   {
57     return item->ssa_name.var->decl_minimal.uid;
58   }
59 
60   /* Return true if the DECL_UID in both trees are equal.  */
61 
62   static bool
equalssa_name_hasher63   equal (tree a, tree b)
64 {
65   return (a->ssa_name.var->decl_minimal.uid == b->ssa_name.var->decl_minimal.uid);
66 }
67 };
68 
69 /* Gimple dataflow datastructure. All publicly available fields shall have
70    gimple_ accessor defined, all publicly modifiable fields should have
71    gimple_set accessor.  */
72 struct GTY(()) gimple_df {
73   /* Array of all SSA_NAMEs used in the function.  */
74   vec<tree, va_gc> *ssa_names;
75 
76   /* Artificial variable used for the virtual operand FUD chain.  */
77   tree vop;
78 
79   /* The PTA solution for the ESCAPED artificial variable.  */
80   struct pt_solution escaped;
81 
82   /* A map of decls to artificial ssa-names that point to the partition
83      of the decl.  */
84   hash_map<tree, tree> * GTY((skip(""))) decls_to_pointers;
85 
86   /* Free list of SSA_NAMEs.  */
87   vec<tree, va_gc> *free_ssanames;
88 
89   /* Queue of SSA_NAMEs to be freed at the next opportunity.  */
90   vec<tree, va_gc> *free_ssanames_queue;
91 
92   /* Hashtable holding definition for symbol.  If this field is not NULL, it
93      means that the first reference to this variable in the function is a
94      USE or a VUSE.  In those cases, the SSA renamer creates an SSA name
95      for this variable with an empty defining statement.  */
96   hash_table<ssa_name_hasher> *default_defs;
97 
98   /* True if there are any symbols that need to be renamed.  */
99   unsigned int ssa_renaming_needed : 1;
100 
101   /* True if all virtual operands need to be renamed.  */
102   unsigned int rename_vops : 1;
103 
104   /* True if the code is in ssa form.  */
105   unsigned int in_ssa_p : 1;
106 
107   /* True if IPA points-to information was computed for this function.  */
108   unsigned int ipa_pta : 1;
109 
110   struct ssa_operands ssa_operands;
111 
112   /* Map gimple stmt to tree label (or list of labels) for transaction
113      restart and abort.  */
114   hash_table<tm_restart_hasher> *tm_restart;
115 };
116 
117 
118 /* Return true when gimple SSA form was built.
119    gimple_in_ssa_p is queried by gimplifier in various early stages before SSA
120    infrastructure is initialized.  Check for presence of the datastructures
121    at first place.  */
122 static inline bool
gimple_in_ssa_p(const struct function * fun)123 gimple_in_ssa_p (const struct function *fun)
124 {
125   return fun && fun->gimple_df && fun->gimple_df->in_ssa_p;
126 }
127 
128 /* Artificial variable used for the virtual operand FUD chain.  */
129 static inline tree
gimple_vop(const struct function * fun)130 gimple_vop (const struct function *fun)
131 {
132   gcc_checking_assert (fun && fun->gimple_df);
133   return fun->gimple_df->vop;
134 }
135 
136 /* Return the set of VUSE operand for statement G.  */
137 
138 static inline use_operand_p
gimple_vuse_op(const gimple * g)139 gimple_vuse_op (const gimple *g)
140 {
141   struct use_optype_d *ops;
142   const gimple_statement_with_memory_ops *mem_ops_stmt =
143      dyn_cast <const gimple_statement_with_memory_ops *> (g);
144   if (!mem_ops_stmt)
145     return NULL_USE_OPERAND_P;
146   ops = mem_ops_stmt->use_ops;
147   if (ops
148       && USE_OP_PTR (ops)->use == &mem_ops_stmt->vuse)
149     return USE_OP_PTR (ops);
150   return NULL_USE_OPERAND_P;
151 }
152 
153 /* Return the set of VDEF operand for statement G.  */
154 
155 static inline def_operand_p
gimple_vdef_op(gimple * g)156 gimple_vdef_op (gimple *g)
157 {
158   gimple_statement_with_memory_ops *mem_ops_stmt =
159      dyn_cast <gimple_statement_with_memory_ops *> (g);
160   if (!mem_ops_stmt)
161     return NULL_DEF_OPERAND_P;
162   if (mem_ops_stmt->vdef)
163     return &mem_ops_stmt->vdef;
164   return NULL_DEF_OPERAND_P;
165 }
166 
167 /* Mark statement S as modified, and update it.  */
168 
169 static inline void
update_stmt(gimple * s)170 update_stmt (gimple *s)
171 {
172   if (gimple_has_ops (s))
173     {
174       gimple_set_modified (s, true);
175       update_stmt_operands (cfun, s);
176     }
177 }
178 
179 /* Update statement S if it has been optimized.  */
180 
181 static inline void
update_stmt_if_modified(gimple * s)182 update_stmt_if_modified (gimple *s)
183 {
184   if (gimple_modified_p (s))
185     update_stmt_operands (cfun, s);
186 }
187 
188 /* Mark statement S as modified, and update it.  */
189 
190 static inline void
update_stmt_fn(struct function * fn,gimple * s)191 update_stmt_fn (struct function *fn, gimple *s)
192 {
193   if (gimple_has_ops (s))
194     {
195       gimple_set_modified (s, true);
196       update_stmt_operands (fn, s);
197     }
198 }
199 
200 
201 #endif /* GCC_GIMPLE_SSA_H */
202