gcc/ipa-prop.h

   1 /* Interprocedural analyses.
   2    Copyright (C) 2005, 2007 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef IPA_PROP_H
  21 #define IPA_PROP_H
  22
  23 #include "tree.h"
  24
  25 /* The following definitions and interfaces are used by
  26    interprocedural analyses.  */
  27
  28 /* A jump function for a callsite represents the values passed as actual
  29    arguments of the callsite. There are three main types of values :
  30    Formal - the caller's formal parameter is passed as an actual argument.
  31    Constant - a constant is passed as an actual argument.
  32    Unknown - neither of the above.
  33    Integer and real constants are represented as IPA_CONST and Fortran
  34    constants are represented as IPA_CONST_REF.  */
  35 enum jump_func_type
  36 {
  37   IPA_UNKNOWN,
  38   IPA_CONST,
  39   IPA_CONST_REF,
  40   IPA_PASS_THROUGH
  41 };
  42
  43 /* All formal parameters in the program have a lattice associated with it
  44    computed by the interprocedural stage of IPCP.
  45    There are three main values of the lattice:
  46    TOP - unknown.
  47    BOTTOM - non constant.
  48    CONSTANT_TYPE - constant value.
  49    Cval of formal f will have a constant value if all callsites to this
  50    function have the same constant value passed to f.
  51    Integer and real constants are represented as IPA_CONST and Fortran
  52    constants are represented as IPA_CONST_REF.  */
  53 enum ipa_lattice_type
  54 {
  55   IPA_BOTTOM,
  56   IPA_CONST_VALUE,
  57   IPA_CONST_VALUE_REF,
  58   IPA_TOP
  59 };
  60
  61 /* Represents a value of a jump function.
  62    value represents a constant.
  63    formal_id is used only in jump function context and represents
  64    pass-through parameter (the formal of caller is passed as argument).  */
  65 union jump_func_value
  66 {
  67   unsigned int formal_id;
  68   tree constant;
  69 };
  70
  71 /* A jump function for a callsite represents the values passed as actual
  72    arguments of the callsite. See enum jump_func_type for the various
  73    types of jump functions supported.  */
  74 struct ipa_jump_func
  75 {
  76   enum jump_func_type type;
  77   union jump_func_value value;
  78 };
  79
  80 /* All formal parameters in the program have a cval computed by
  81    the interprocedural stage of IPCP. See enum ipa_lattice_type for
  82    the various types of lattices supported */
  83 struct ipcp_lattice
  84 {
  85   enum ipa_lattice_type type;
  86   tree constant;
  87 };
  88
  89 /* Represent which DECL tree (or reference to such tree)
  90    will be replaced by another tree while versioning.  */
  91 struct ipa_replace_map
  92 {
  93   /* The tree that will be replaced.  */
  94   tree old_tree;
  95   /* The new (replacing) tree.  */
  96   tree new_tree;
  97   /* True when a substitution should be done, false otherwise.  */
  98   bool replace_p;
  99   /* True when we replace a reference to old_tree.  */
 100   bool ref_p;
 101 };
 102
 103 /* Return the field in cgraph_node/cgraph_edge struct that points
 104    to ipa_node_params/ipa_edge_args struct.  */
 105 #define IPA_NODE_REF(MT) ((struct ipa_node_params *)(MT)->aux)
 106 #define IPA_EDGE_REF(EDGE) ((struct ipa_edge_args *)(EDGE)->aux)
 107 /* This macro checks validity of index returned by
 108    ipa_get_param_decl_index function.  */
 109 #define IS_VALID_JUMP_FUNC_INDEX(I) ((I) != -1)
 110
 111 /* ipa_node_params stores information related to formal parameters of functions
 112    and some other information for interprocedural passes that operate on
 113    parameters (such as ipa-cp).  */
 114
 115 struct ipa_node_params
 116 {
 117   /* Number of formal parameters of this function.  When set to 0,
 118      this functions's parameters would not be analyzed by the different
 119      stages of IPA CP.  */
 120   int param_count;
 121   /* Array of lattices.  */
 122   struct ipcp_lattice *ipcp_lattices;
 123   /* Mapping each parameter to its PARM_DECL tree.  */
 124   tree *param_decls;
 125   /* Indicating which parameter is modified in its function.  */
 126   bool *modified_flags;
 127   /* Only for versioned nodes this field would not be NULL,
 128      it points to the node that IPA cp cloned from.  */
 129   struct cgraph_node *ipcp_orig_node;
 130   /* Meaningful only for original functions.  Expresses the
 131      ratio between the direct calls and sum of all invocations of
 132      this function (given by profiling info).  It is used to calculate
 133      the profiling information of the original function and the versioned
 134      one.  */
 135   gcov_type count_scale;
 136
 137   /* Whether this fynction is called with variable number of actual
 138      arguments.  */
 139   unsigned called_with_var_arguments : 1;
 140 };
 141
 142 /* ipa_node_params access functions.  Please use these to access fields that
 143    are or will be shared among various passes.  */
 144
 145 /* Set the number of formal parameters. */
 146 static inline void
 147 ipa_set_param_count (struct ipa_node_params *info, int count)
 148 {
 149   info->param_count = count;
 150 }
 151
 152 /* Return the number of formal parameters. */
 153 static inline int
 154 ipa_get_param_count (struct ipa_node_params *info)
 155 {
 156   return info->param_count;
 157 }
 158
 159 /* Returns the declaration of ith param of the corresponding node.  Note there
 160    is no setter function as this array is built just once using
 161    ipa_create_param_decls_array. */
 162 static inline tree
 163 ipa_get_ith_param (struct ipa_node_params *info, int i)
 164 {
 165   return info->param_decls[i];
 166 }
 167
 168 /* Returns the modification flag corresponding o the ith paramterer.  Note
 169    there is no setter method as the goal is to set all flags when building the
 170    array in ipa_detect_param_modifications.  */
 171 static inline bool
 172 ipa_is_ith_param_modified (struct ipa_node_params *info, int i)
 173 {
 174   return info->modified_flags[i];
 175 }
 176
 177 /* Flag this node as having callers with variable number of arguments.  */
 178 static inline void
 179 ipa_set_called_with_variable_arg (struct ipa_node_params *info)
 180 {
 181   info->called_with_var_arguments = 1;
 182 }
 183
 184 /* Have we detected this node was called with variable number of arguments? */
 185 static inline bool
 186 ipa_is_called_with_var_arguments (struct ipa_node_params *info)
 187 {
 188   return info->called_with_var_arguments;
 189 }
 190
 191
 192
 193 /* ipa_edge_args stores information related to a callsite and particularly
 194    its arguments. It is pointed to by a field in the
 195    callsite's corresponding cgraph_edge.  */
 196 struct ipa_edge_args
 197 {
 198   /* Number of actual arguments in this callsite.  When set to 0,
 199      this callsite's parameters would not be analyzed by the different
 200      stages of IPA CP.  */
 201   int argument_count;
 202   /* Array of the callsite's jump function of each parameter.  */
 203   struct ipa_jump_func *jump_functions;
 204 };
 205
 206 /* ipa_edge_args access functions.  Please use these to access fields that
 207    are or will be shared among various passes.  */
 208
 209 /* Set the number of actual arguments. */
 210 static inline void
 211 ipa_set_cs_argument_count (struct ipa_edge_args *args, int count)
 212 {
 213   args->argument_count = count;
 214 }
 215
 216 /* Return the number of actual arguments. */
 217 static inline int
 218 ipa_get_cs_argument_count (struct ipa_edge_args *args)
 219 {
 220   return args->argument_count;
 221 }
 222
 223 /* Returns a pointer to the jump function for the ith argument.  Please note
 224    there is no setter function as jump functions are all set up in
 225    ipa_compute_jump_functions. */
 226 static inline struct ipa_jump_func *
 227 ipa_get_ith_jump_func (struct ipa_edge_args *args, int i)
 228 {
 229   return &args->jump_functions[i];
 230 }
 231
 232 /* A function list element.  It is used to create a temporary worklist used in
 233    the propagation stage of IPCP. (can be used for more IPA optimizations)  */
 234 struct ipa_func_list
 235 {
 236   struct cgraph_node *node;
 237   struct ipa_func_list *next;
 238 };
 239
 240 /* ipa_func_list interface.  */
 241 struct ipa_func_list *ipa_init_func_list (void);
 242 void ipa_push_func_to_list (struct ipa_func_list **, struct cgraph_node *);
 243 struct cgraph_node *ipa_pop_func_from_list (struct ipa_func_list **);
 244
 245 /* Callsite related calculations.  */
 246 void ipa_compute_jump_functions (struct cgraph_edge *);
 247 void ipa_count_arguments (struct cgraph_edge *);
 248
 249 /* Function parameters related computations.  */
 250 void ipa_count_formal_params (struct cgraph_node *);
 251 void ipa_create_param_decls_array (struct cgraph_node *);
 252 void ipa_detect_param_modifications (struct cgraph_node *);
 253
 254 /* Creating and freeing ipa_node_params and ipa_edge_args.  */
 255 void ipa_create_node_params (struct cgraph_node *);
 256 void ipa_free_all_node_params (void);
 257 void ipa_create_all_node_params (void);
 258 void ipa_create_all_edge_args (void);
 259 void ipa_free_all_edge_args (void);
 260
 261 /* Debugging interface.  */
 262 void ipa_print_all_tree_maps (FILE *);
 263 void ipa_print_all_params_modified (FILE *);
 264
 265 #endif /* IPA_PROP_H */