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 #define DF_FOR_REGALLOC 4096    /* If called for the register allocator.  */
  41
  42 enum df_ref_type {DF_REF_REG_DEF, DF_REF_REG_USE, DF_REF_REG_MEM_LOAD,
  43                   DF_REF_REG_MEM_STORE};
  44
  45 #define DF_REF_TYPE_NAMES {"def", "use", "mem load", "mem store"}
  46
  47 /* Link on a def-use or use-def chain.  */
  48 struct df_link
  49 {
  50   struct df_link *next;
  51   struct ref *ref;
  52 };
  53
  54 enum df_ref_flags
  55   {
  56     /* Read-modify-write refs generate both a use and a def and
  57        these are marked with this flag to show that they are not
  58        independent.  */
  59     DF_REF_READ_WRITE = 1,
  60
  61     /* This flag is set on register references inside a subreg on
  62        machines which have CANNOT_CHANGE_MODE_CLASS.
  63        Note, that this flag can also be set on df_refs representing
  64        the REG itself (i.e., one might not see the subreg anymore).
  65        Also note, that this flag is set also for hardreg refs, i.e.,
  66        you must check yourself if it's a pseudo.  */
  67     DF_REF_MODE_CHANGE = 2,
  68
  69     /* This flag is set, if we stripped the subreg from the reference.
  70        In this case we must make conservative guesses, at what the
  71        outer mode was.  */
  72     DF_REF_STRIPPED = 4,
  73
  74     /* This flag is set during register allocation if it's okay for
  75     the reference's INSN to have one of its operands replaced with a
  76     memory reference.  */
  77     DF_REF_MEM_OK = 8
  78   };
  79
  80
  81 /* Define a register reference structure.  One of these is allocated
  82    for every register reference (use or def).  Note some register
  83    references (e.g., post_inc, subreg) generate both a def and a use.  */
  84 struct ref
  85 {
  86   rtx reg;                      /* The register referenced.  */
  87   rtx insn;                     /* Insn containing ref.  */
  88   rtx *loc;                     /* The location of the reg.  */
  89   struct df_link *chain;        /* Head of def-use or use-def chain.  */
  90   unsigned int id;              /* Ref index.  */
  91   enum df_ref_type type;        /* Type of ref.  */
  92   enum df_ref_flags flags;      /* Various flags.  */
  93   void *data;                   /* The data assigned to it by user.  */
  94 };
  95
  96
  97 /* One of these structures is allocated for every insn.  */
  98 struct insn_info
  99 {
 100   struct df_link *defs;         /* Head of insn-def chain.  */
 101   struct df_link *uses;         /* Head of insn-use chain.  */
 102   /* ???? The following luid field should be considered private so that
 103      we can change it on the fly to accommodate new insns?  */
 104   int luid;                     /* Logical UID.  */
 105 };
 106
 107
 108 /* One of these structures is allocated for every reg.  */
 109 struct reg_info
 110 {
 111   struct df_link *defs;         /* Head of reg-def chain.  */
 112   struct df_link *uses;         /* Head of reg-use chain.  */
 113   int lifetime;
 114   int n_defs;
 115   int n_uses;
 116 };
 117
 118
 119 /* One of these structures is allocated for every basic block.  */
 120 struct bb_info
 121 {
 122   /* Reaching def bitmaps have def_id elements.  */
 123   bitmap rd_kill;
 124   bitmap rd_gen;
 125   bitmap rd_in;
 126   bitmap rd_out;
 127   /* Reaching use bitmaps have use_id elements.  */
 128   bitmap ru_kill;
 129   bitmap ru_gen;
 130   bitmap ru_in;
 131   bitmap ru_out;
 132   /* Live variable bitmaps have n_regs elements.  */
 133   bitmap lr_def;
 134   bitmap lr_use;
 135   bitmap lr_in;
 136   bitmap lr_out;
 137   int rd_valid;
 138   int ru_valid;
 139   int lr_valid;
 140 };
 141
 142
 143 struct df
 144 {
 145   int flags;                    /* Indicates what's recorded.  */
 146   struct bb_info *bbs;          /* Basic block table.  */
 147   struct ref **defs;            /* Def table, indexed by def_id.  */
 148   struct ref **uses;            /* Use table, indexed by use_id.  */
 149   struct ref **reg_def_last;    /* Indexed by regno.  */
 150   struct reg_info *regs;        /* Regs table, index by regno.  */
 151   unsigned int reg_size;        /* Size of regs table.  */
 152   struct insn_info *insns;      /* Insn table, indexed by insn UID.  */
 153   unsigned int insn_size;       /* Size of insn table.  */
 154   unsigned int def_id;          /* Next def ID.  */
 155   unsigned int def_size;        /* Size of def table.  */
 156   unsigned int n_defs;          /* Size of def bitmaps.  */
 157   unsigned int use_id;          /* Next use ID.  */
 158   unsigned int use_size;        /* Size of use table.  */
 159   unsigned int n_uses;          /* Size of use bitmaps.  */
 160   unsigned int n_bbs;           /* Number of basic blocks.  */
 161   unsigned int n_regs;          /* Number of regs.  */
 162   unsigned int def_id_save;     /* Saved next def ID.  */
 163   unsigned int use_id_save;     /* Saved next use ID.  */
 164   bitmap insns_modified;        /* Insns that (may) have changed.  */
 165   bitmap bbs_modified;          /* Blocks that (may) have changed.  */
 166   bitmap all_blocks;            /* All blocks in CFG.  */
 167   int *dfs_order;               /* DFS order -> block number.  */
 168   int *rc_order;                /* Reverse completion order -> block number.  */
 169   int *rts_order;               /* Reverse top sort order -> block number.  */
 170   int *inverse_rc_map;          /* Block number -> reverse completion order.  */
 171   int *inverse_dfs_map;         /* Block number -> DFS order.  */
 172   int *inverse_rts_map;         /* Block number -> reverse top-sort order.  */
 173 };
 174
 175
 176 struct df_map
 177 {
 178   rtx old;
 179   rtx new;
 180 };
 181
 182
 183 #define DF_BB_INFO(REFS, BB) (&REFS->bbs[(BB)->index])
 184
 185
 186 /* Macros to access the elements within the ref structure.  */
 187
 188 #define DF_REF_REAL_REG(REF) (GET_CODE ((REF)->reg) == SUBREG \
 189                                 ? SUBREG_REG ((REF)->reg) : ((REF)->reg))
 190 #define DF_REF_REGNO(REF) REGNO (DF_REF_REAL_REG (REF))
 191 #define DF_REF_REAL_LOC(REF) (GET_CODE ((REF)->reg) == SUBREG \
 192                                 ? &SUBREG_REG ((REF)->reg) : ((REF)->loc))
 193 #define DF_REF_REG(REF) ((REF)->reg)
 194 #define DF_REF_LOC(REF) ((REF)->loc)
 195 #define DF_REF_BB(REF) (BLOCK_FOR_INSN ((REF)->insn))
 196 #define DF_REF_BBNO(REF) (BLOCK_FOR_INSN ((REF)->insn)->index)
 197 #define DF_REF_INSN(REF) ((REF)->insn)
 198 #define DF_REF_INSN_UID(REF) (INSN_UID ((REF)->insn))
 199 #define DF_REF_TYPE(REF) ((REF)->type)
 200 #define DF_REF_CHAIN(REF) ((REF)->chain)
 201 #define DF_REF_ID(REF) ((REF)->id)
 202 #define DF_REF_FLAGS(REF) ((REF)->flags)
 203 #define DF_REF_DATA(REF) ((REF)->data)
 204
 205 /* Macros to determine the reference type.  */
 206
 207 #define DF_REF_REG_DEF_P(REF) (DF_REF_TYPE (REF) == DF_REF_REG_DEF)
 208 #define DF_REF_REG_USE_P(REF) ((REF) && ! DF_REF_REG_DEF_P (REF))
 209 #define DF_REF_REG_MEM_STORE_P(REF) (DF_REF_TYPE (REF) == DF_REF_REG_MEM_STORE)
 210 #define DF_REF_REG_MEM_LOAD_P(REF) (DF_REF_TYPE (REF) == DF_REF_REG_MEM_LOAD)
 211 #define DF_REF_REG_MEM_P(REF) (DF_REF_REG_MEM_STORE_P (REF) \
 212                                || DF_REF_REG_MEM_LOAD_P (REF))
 213
 214
 215 /* Macros to access the elements within the reg_info structure table.  */
 216
 217 #define DF_REGNO_FIRST_DEF(DF, REGNUM) \
 218 ((DF)->regs[REGNUM].defs ? (DF)->regs[REGNUM].defs->ref : 0)
 219 #define DF_REGNO_LAST_USE(DF, REGNUM) \
 220 ((DF)->regs[REGNUM].uses ? (DF)->regs[REGNUM].uses->ref : 0)
 221
 222 #define DF_REGNO_FIRST_BB(DF, REGNUM) \
 223 (DF_REGNO_FIRST_DEF (DF, REGNUM) \
 224 ? DF_REF_BB (DF_REGNO_FIRST_DEF (DF, REGNUM)) : 0)
 225 #define DF_REGNO_LAST_BB(DF, REGNUM) \
 226 (DF_REGNO_LAST_USE (DF, REGNUM) \
 227 ? DF_REF_BB (DF_REGNO_LAST_USE (DF, REGNUM)) : 0)
 228
 229
 230 /* Macros to access the elements within the insn_info structure table.  */
 231
 232 #define DF_INSN_LUID(DF, INSN) ((DF)->insns[INSN_UID (INSN)].luid)
 233 #define DF_INSN_DEFS(DF, INSN) ((DF)->insns[INSN_UID (INSN)].defs)
 234 #define DF_INSN_USES(DF, INSN) ((DF)->insns[INSN_UID (INSN)].uses)
 235
 236
 237 /* Functions to build and analyze dataflow information.  */
 238
 239 extern struct df *df_init (void);
 240
 241 extern int df_analyze (struct df *, bitmap, int);
 242 extern void df_analyze_subcfg (struct df *, bitmap, int);
 243
 244 extern void df_finish (struct df *);
 245
 246 extern void df_dump (struct df *, int, FILE *);
 247
 248
 249 /* Functions to modify insns.  */
 250
 251 extern void df_insn_modify (struct df *, basic_block, rtx);
 252
 253 extern rtx df_insn_delete (struct df *, basic_block, rtx);
 254
 255 extern rtx df_pattern_emit_before (struct df *, rtx, basic_block, rtx);
 256
 257 extern rtx df_jump_pattern_emit_after (struct df *, rtx, basic_block, rtx);
 258
 259 extern rtx df_pattern_emit_after (struct df *, rtx, basic_block, rtx);
 260
 261 extern rtx df_insn_move_before (struct df *, basic_block, rtx, basic_block,
 262                                 rtx);
 263
 264 extern int df_reg_replace (struct df *, bitmap, rtx, rtx);
 265
 266 extern int df_ref_reg_replace (struct df *, struct ref *, rtx, rtx);
 267
 268 extern int df_ref_remove (struct df *, struct ref *);
 269
 270 extern int df_insn_mem_replace (struct df *, basic_block, rtx, rtx, rtx);
 271
 272 extern struct ref *df_bb_def_use_swap (struct df *, basic_block, rtx, rtx,
 273                                        unsigned int);
 274
 275
 276 /* Functions to query dataflow information.  */
 277
 278 extern basic_block df_regno_bb (struct df *, unsigned int);
 279
 280 extern int df_reg_lifetime (struct df *, rtx);
 281
 282 extern int df_reg_global_p (struct df *, rtx);
 283
 284 extern int df_insn_regno_def_p (struct df *, basic_block, rtx, unsigned int);
 285
 286 extern int df_insn_dominates_all_uses_p (struct df *, basic_block, rtx);
 287
 288 extern int df_insn_dominates_uses_p (struct df *, basic_block, rtx, bitmap);
 289
 290 extern int df_bb_reg_live_start_p (struct df *, basic_block, rtx);
 291
 292 extern int df_bb_reg_live_end_p (struct df *, basic_block, rtx);
 293
 294 extern int df_bb_regs_lives_compare (struct df *, basic_block, rtx, rtx);
 295
 296 extern rtx df_bb_single_def_use_insn_find (struct df *, basic_block, rtx,
 297                                            rtx);
 298 extern struct ref *df_bb_regno_last_use_find (struct df *, basic_block, unsigned int);
 299
 300 extern struct ref *df_bb_regno_first_def_find (struct df *, basic_block, unsigned int);
 301
 302 extern struct ref *df_bb_regno_last_def_find (struct df *, basic_block, unsigned int);
 303
 304 extern struct ref *df_find_def (struct df *, rtx, rtx);
 305
 306 extern int df_reg_used (struct df *, rtx, rtx);
 307
 308 /* Functions for debugging from GDB.  */
 309
 310 extern void debug_df_insn (rtx);
 311
 312 extern void debug_df_regno (unsigned int);
 313
 314 extern void debug_df_reg (rtx);
 315
 316 extern void debug_df_defno (unsigned int);
 317
 318 extern void debug_df_useno (unsigned int);
 319
 320 extern void debug_df_ref (struct ref *);
 321
 322 extern void debug_df_chain (struct df_link *);
 323
 324 extern void df_insn_debug (struct df *, rtx, FILE *);
 325
 326 extern void df_insn_debug_regno (struct df *, rtx, FILE *);
 327
 328
 329 /* Meet over any path (UNION) or meet over all paths (INTERSECTION).  */
 330 enum df_confluence_op
 331   {
 332     DF_UNION,
 333     DF_INTERSECTION
 334   };
 335
 336
 337 /* Dataflow direction.  */
 338 enum df_flow_dir
 339   {
 340     DF_FORWARD,
 341     DF_BACKWARD
 342   };
 343
 344
 345 typedef void (*transfer_function) (int, int *, void *, void *,
 346                                    void *, void *, void *);
 347
 348 /* The description of a dataflow problem to solve.  */
 349
 350 enum set_representation
 351 {
 352   SR_SBITMAP,           /* Represent sets by bitmaps.  */
 353   SR_BITMAP             /* Represent sets by sbitmaps.  */
 354 };
 355
 356 struct dataflow
 357 {
 358   enum set_representation repr;         /* The way the sets are represented.  */
 359
 360   /* The following arrays are indexed by block indices, so they must always
 361      be large enough even if we restrict ourselves just to a subset of cfg.  */
 362   void **gen, **kill;                   /* Gen and kill sets.  */
 363   void **in, **out;                     /* Results.  */
 364
 365   enum df_flow_dir dir;                 /* Dataflow direction.  */
 366   enum df_confluence_op conf_op;        /* Confluence operator.  */
 367   unsigned n_blocks;                    /* Number of basic blocks in the
 368                                            order.  */
 369   int *order;                           /* The list of basic blocks to work
 370                                            with, in the order they should
 371                                            be processed in.  */
 372   transfer_function transfun;           /* The transfer function.  */
 373   void *data;                           /* Data used by the transfer
 374                                            function.  */
 375 };
 376
 377 extern void iterative_dataflow (struct dataflow *);
 378 extern bool read_modify_subreg_p (rtx);
 379
 380 #endif /* GCC_DF_H */