gcc/df.h

   1 /* Form lists of pseudo register references for autoinc optimization
   2    for GNU compiler.  This is part of flow optimization.
   3    Copyright (C) 1999, 2000, 2001, 2003, 2004 Free Software Foundation, Inc.
   4    Contributed by Michael P. Hayes (m.hayes@elec.canterbury.ac.nz)
   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 2, 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 COPYING.  If not, write to the Free
  20 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  21 02111-1307, USA.  */
  22
  23 #ifndef GCC_DF_H
  24 #define GCC_DF_H
  25
  26 #include "bitmap.h"
  27 #include "basic-block.h"
  28
  29 #define DF_RD           1       /* Reaching definitions.  */
  30 #define DF_RU           2       /* Reaching uses.  */
  31 #define DF_LR           4       /* Live registers.  */
  32 #define DF_DU_CHAIN     8       /* Def-use chain.  */
  33 #define DF_UD_CHAIN     16      /* Use-def chain.  */
  34 #define DF_REG_INFO     32      /* Register info.  */
  35 #define DF_RD_CHAIN     64      /* Reg-def chain.  */
  36 #define DF_RU_CHAIN     128     /* Reg-use chain.  */
  37 #define DF_ALL          255
  38 #define DF_HARD_REGS    1024    /* Mark hard registers.  */
  39 #define DF_EQUIV_NOTES  2048    /* Mark uses present in EQUIV/EQUAL notes.  */
  40
  41 enum df_ref_type {DF_REF_REG_DEF, DF_REF_REG_USE, DF_REF_REG_MEM_LOAD,
  42                   DF_REF_REG_MEM_STORE};
  43
  44 #define DF_REF_TYPE_NAMES {"def", "use", "mem load", "mem store"}
  45
  46 /* Link on a def-use or use-def chain.  */
  47 struct df_link
  48 {
  49   struct df_link *next;
  50   struct ref *ref;
  51 };
  52
  53 enum df_ref_flags
  54   {
  55     /* Read-modify-write refs generate both a use and a def and
  56        these are marked with this flag to show that they are not
  57        independent.  */
  58     DF_REF_READ_WRITE = 1,
  59
  60     /* This flag is set on register references inside a subreg on
  61        machines which have CANNOT_CHANGE_MODE_CLASS.
  62        Note, that this flag can also be set on df_refs representing
  63        the REG itself (i.e., one might not see the subreg anymore).
  64        Also note, that this flag is set also for hardreg refs, i.e.,
  65        you must check yourself if it's a pseudo.  */
  66     DF_REF_MODE_CHANGE = 2,
  67
  68     /* This flag is set, if we stripped the subreg from the reference.
  69        In this case we must make conservative guesses, at what the
  70        outer mode was.  */
  71     DF_REF_STRIPPED = 4,
  72
  73     /* This flag is set during register allocation if it's okay for
  74     the reference's INSN to have one of its operands replaced with a
  75     memory reference.  */
  76     DF_REF_MEM_OK = 8
  77   };
  78
  79
  80 /* Define a register reference structure.  One of these is allocated
  81    for every register reference (use or def).  Note some register
  82    references (e.g., post_inc, subreg) generate both a def and a use.  */
  83 struct ref
  84 {
  85   rtx reg;                      /* The register referenced.  */
  86   rtx insn;                     /* Insn containing ref.  */
  87   rtx *loc;                     /* The location of the reg.  */
  88   struct df_link *chain;        /* Head of def-use or use-def chain.  */
  89   unsigned int id;              /* Ref index.  */
  90   enum df_ref_type type;        /* Type of ref.  */
  91   enum df_ref_flags flags;      /* Various flags.  */
  92   void *data;                   /* The data assigned to it by user.  */
  93 };
  94
  95
  96 /* One of these structures is allocated for every insn.  */
  97 struct insn_info
  98 {
  99   struct df_link *defs;         /* Head of insn-def chain.  */
 100   struct df_link *uses;         /* Head of insn-use chain.  */
 101   /* ???? The following luid field should be considered private so that
 102      we can change it on the fly to accommodate new insns?  */
 103   int luid;                     /* Logical UID.  */
 104 };
 105
 106
 107 /* One of these structures is allocated for every reg.  */
 108 struct reg_info
 109 {
 110   struct df_link *defs;         /* Head of reg-def chain.  */
 111   struct df_link *uses;         /* Head of reg-use chain.  */
 112   int lifetime;
 113   int n_defs;
 114   int n_uses;
 115 };
 116
 117
 118 /* One of these structures is allocated for every basic block.  */
 119 struct bb_info
 120 {
 121   /* Reaching def bitmaps have def_id elements.  */
 122   bitmap rd_kill;
 123   bitmap rd_gen;
 124   bitmap rd_in;
 125   bitmap rd_out;
 126   /* Reaching use bitmaps have use_id elements.  */
 127   bitmap ru_kill;
 128   bitmap ru_gen;
 129   bitmap ru_in;
 130   bitmap ru_out;
 131   /* Live variable bitmaps have n_regs elements.  */
 132   bitmap lr_def;
 133   bitmap lr_use;
 134   bitmap lr_in;
 135   bitmap lr_out;
 136   int rd_valid;
 137   int ru_valid;
 138   int lr_valid;
 139 };
 140
 141
 142 struct df
 143 {
 144   int flags;                    /* Indicates what's recorded.  */
 145   struct bb_info *bbs;          /* Basic block table.  */
 146   struct ref **defs;            /* Def table, indexed by def_id.  */
 147   struct ref **uses;            /* Use table, indexed by use_id.  */
 148   struct ref **reg_def_last;    /* Indexed by regno.  */
 149   struct reg_info *regs;        /* Regs table, index by regno.  */
 150   unsigned int reg_size;        /* Size of regs table.  */
 151   struct insn_info *insns;      /* Insn table, indexed by insn UID.  */
 152   unsigned int insn_size;       /* Size of insn table.  */
 153   unsigned int def_id;          /* Next def ID.  */
 154   unsigned int def_size;        /* Size of def table.  */
 155   unsigned int n_defs;          /* Size of def bitmaps.  */
 156   unsigned int use_id;          /* Next use ID.  */
 157   unsigned int use_size;        /* Size of use table.  */
 158   unsigned int n_uses;          /* Size of use bitmaps.  */
 159   unsigned int n_bbs;           /* Number of basic blocks.  */
 160   unsigned int n_regs;          /* Number of regs.  */
 161   unsigned int def_id_save;     /* Saved next def ID.  */
 162   unsigned int use_id_save;     /* Saved next use ID.  */
 163   bitmap insns_modified;        /* Insns that (may) have changed.  */
 164   bitmap bbs_modified;          /* Blocks that (may) have changed.  */
 165   bitmap all_blocks;            /* All blocks in CFG.  */
 166   int *dfs_order;               /* DFS order -> block number.  */
 167   int *rc_order;                /* Reverse completion order -> block number.  */
 168   int *rts_order;               /* Reverse top sort order -> block number.  */
 169   int *inverse_rc_map;          /* Block number -> reverse completion order.  */
 170   int *inverse_dfs_map;         /* Block number -> DFS order.  */
 171   int *inverse_rts_map;         /* Block number -> reverse top-sort order.  */
 172 };
 173
 174
 175 struct df_map
 176 {
 177   rtx old;
 178   rtx new;
 179 };
 180
 181
 182 #define DF_BB_INFO(REFS, BB) (&REFS->bbs[(BB)->index])
 183
 184
 185 /* Macros to access the elements within the ref structure.  */
 186
 187 #define DF_REF_REAL_REG(REF) (GET_CODE ((REF)->reg) == SUBREG \
 188                                 ? SUBREG_REG ((REF)->reg) : ((REF)->reg))
 189 #define DF_REF_REGNO(REF) REGNO (DF_REF_REAL_REG (REF))
 190 #define DF_REF_REAL_LOC(REF) (GET_CODE ((REF)->reg) == SUBREG \
 191                                 ? &SUBREG_REG ((REF)->reg) : ((REF)->loc))
 192 #define DF_REF_REG(REF) ((REF)->reg)
 193 #define DF_REF_LOC(REF) ((REF)->loc)
 194 #define DF_REF_BB(REF) (BLOCK_FOR_INSN ((REF)->insn))
 195 #define DF_REF_BBNO(REF) (BLOCK_FOR_INSN ((REF)->insn)->index)
 196 #define DF_REF_INSN(REF) ((REF)->insn)
 197 #define DF_REF_INSN_UID(REF) (INSN_UID ((REF)->insn))
 198 #define DF_REF_TYPE(REF) ((REF)->type)
 199 #define DF_REF_CHAIN(REF) ((REF)->chain)
 200 #define DF_REF_ID(REF) ((REF)->id)
 201 #define DF_REF_FLAGS(REF) ((REF)->flags)
 202 #define DF_REF_DATA(REF) ((REF)->data)
 203
 204 /* Macros to determine the reference type.  */
 205
 206 #define DF_REF_REG_DEF_P(REF) (DF_REF_TYPE (REF) == DF_REF_REG_DEF)
 207 #define DF_REF_REG_USE_P(REF) ((REF) && ! DF_REF_REG_DEF_P (REF))
 208 #define DF_REF_REG_MEM_STORE_P(REF) (DF_REF_TYPE (REF) == DF_REF_REG_MEM_STORE)
 209 #define DF_REF_REG_MEM_LOAD_P(REF) (DF_REF_TYPE (REF) == DF_REF_REG_MEM_LOAD)
 210 #define DF_REF_REG_MEM_P(REF) (DF_REF_REG_MEM_STORE_P (REF) \
 211                                || DF_REF_REG_MEM_LOAD_P (REF))
 212
 213
 214 /* Macros to access the elements within the reg_info structure table.  */
 215
 216 #define DF_REGNO_FIRST_DEF(DF, REGNUM) \
 217 ((DF)->regs[REGNUM].defs ? (DF)->regs[REGNUM].defs->ref : 0)
 218 #define DF_REGNO_LAST_USE(DF, REGNUM) \
 219 ((DF)->regs[REGNUM].uses ? (DF)->regs[REGNUM].uses->ref : 0)
 220
 221 #define DF_REGNO_FIRST_BB(DF, REGNUM) \
 222 (DF_REGNO_FIRST_DEF (DF, REGNUM) \
 223 ? DF_REF_BB (DF_REGNO_FIRST_DEF (DF, REGNUM)) : 0)
 224 #define DF_REGNO_LAST_BB(DF, REGNUM) \
 225 (DF_REGNO_LAST_USE (DF, REGNUM) \
 226 ? DF_REF_BB (DF_REGNO_LAST_USE (DF, REGNUM)) : 0)
 227
 228
 229 /* Macros to access the elements within the insn_info structure table.  */
 230
 231 #define DF_INSN_LUID(DF, INSN) ((DF)->insns[INSN_UID (INSN)].luid)
 232 #define DF_INSN_DEFS(DF, INSN) ((DF)->insns[INSN_UID (INSN)].defs)
 233 #define DF_INSN_USES(DF, INSN) ((DF)->insns[INSN_UID (INSN)].uses)
 234
 235
 236 /* Functions to build and analyze dataflow information.  */
 237
 238 extern struct df *df_init (void);
 239
 240 extern int df_analyze (struct df *, bitmap, int);
 241 extern void df_analyze_subcfg (struct df *, bitmap, int);
 242
 243 extern void df_finish (struct df *);
 244
 245 extern void df_dump (struct df *, int, FILE *);
 246
 247
 248 /* Functions to modify insns.  */
 249
 250 extern void df_insn_modify (struct df *, basic_block, rtx);
 251
 252 extern rtx df_insn_delete (struct df *, basic_block, rtx);
 253
 254 extern rtx df_pattern_emit_before (struct df *, rtx, basic_block, rtx);
 255
 256 extern rtx df_jump_pattern_emit_after (struct df *, rtx, basic_block, rtx);
 257
 258 extern rtx df_pattern_emit_after (struct df *, rtx, basic_block, rtx);
 259
 260 extern rtx df_insn_move_before (struct df *, basic_block, rtx, basic_block,
 261                                 rtx);
 262
 263 extern int df_reg_replace (struct df *, bitmap, rtx, rtx);
 264
 265 extern int df_ref_reg_replace (struct df *, struct ref *, rtx, rtx);
 266
 267 extern int df_ref_remove (struct df *, struct ref *);
 268
 269 extern int df_insn_mem_replace (struct df *, basic_block, rtx, rtx, rtx);
 270
 271 extern struct ref *df_bb_def_use_swap (struct df *, basic_block, rtx, rtx,
 272                                        unsigned int);
 273
 274
 275 /* Functions to query dataflow information.  */
 276
 277 extern basic_block df_regno_bb (struct df *, unsigned int);
 278
 279 extern int df_reg_lifetime (struct df *, rtx);
 280
 281 extern int df_reg_global_p (struct df *, rtx);
 282
 283 extern int df_insn_regno_def_p (struct df *, basic_block, rtx, unsigned int);
 284
 285 extern int df_insn_dominates_all_uses_p (struct df *, basic_block, rtx);
 286
 287 extern int df_insn_dominates_uses_p (struct df *, basic_block, rtx, bitmap);
 288
 289 extern int df_bb_reg_live_start_p (struct df *, basic_block, rtx);
 290
 291 extern int df_bb_reg_live_end_p (struct df *, basic_block, rtx);
 292
 293 extern int df_bb_regs_lives_compare (struct df *, basic_block, rtx, rtx);
 294
 295 extern rtx df_bb_single_def_use_insn_find (struct df *, basic_block, rtx,
 296                                            rtx);
 297 extern struct ref *df_bb_regno_last_use_find (struct df *, basic_block, unsigned int);
 298
 299 extern struct ref *df_bb_regno_first_def_find (struct df *, basic_block, unsigned int);
 300
 301 extern struct ref *df_bb_regno_last_def_find (struct df *, basic_block, unsigned int);
 302
 303 extern struct ref *df_find_def (struct df *, rtx, rtx);
 304
 305 extern int df_reg_used (struct df *, rtx, rtx);
 306
 307 /* Functions for debugging from GDB.  */
 308
 309 extern void debug_df_insn (rtx);
 310
 311 extern void debug_df_regno (unsigned int);
 312
 313 extern void debug_df_reg (rtx);
 314
 315 extern void debug_df_defno (unsigned int);
 316
 317 extern void debug_df_useno (unsigned int);
 318
 319 extern void debug_df_ref (struct ref *);
 320
 321 extern void debug_df_chain (struct df_link *);
 322
 323 extern void df_insn_debug (struct df *, rtx, FILE *);
 324
 325 extern void df_insn_debug_regno (struct df *, rtx, FILE *);
 326
 327
 328 /* Meet over any path (UNION) or meet over all paths (INTERSECTION).  */
 329 enum df_confluence_op
 330   {
 331     DF_UNION,
 332     DF_INTERSECTION
 333   };
 334
 335
 336 /* Dataflow direction.  */
 337 enum df_flow_dir
 338   {
 339     DF_FORWARD,
 340     DF_BACKWARD
 341   };
 342
 343
 344 typedef void (*transfer_function) (int, int *, void *, void *,
 345                                    void *, void *, void *);
 346
 347 /* The description of a dataflow problem to solve.  */
 348
 349 enum set_representation
 350 {
 351   SR_SBITMAP,           /* Represent sets by bitmaps.  */
 352   SR_BITMAP             /* Represent sets by sbitmaps.  */
 353 };
 354
 355 struct dataflow
 356 {
 357   enum set_representation repr;         /* The way the sets are represented.  */
 358
 359   /* The following arrays are indexed by block indices, so they must always
 360      be large enough even if we restrict ourselves just to a subset of cfg.  */
 361   void **gen, **kill;                   /* Gen and kill sets.  */
 362   void **in, **out;                     /* Results.  */
 363
 364   enum df_flow_dir dir;                 /* Dataflow direction.  */
 365   enum df_confluence_op conf_op;        /* Confluence operator.  */
 366   unsigned n_blocks;                    /* Number of basic blocks in the
 367                                            order.  */
 368   int *order;                           /* The list of basic blocks to work
 369                                            with, in the order they should
 370                                            be processed in.  */
 371   transfer_function transfun;           /* The transfer function.  */
 372   void *data;                           /* Data used by the transfer
 373                                            function.  */
 374 };
 375
 376 extern void iterative_dataflow (struct dataflow *);
 377 extern bool read_modify_subreg_p (rtx);
 378
 379 #endif /* GCC_DF_H */