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 #define DF_RD            1      /* Reaching definitions.  */
  24 #define DF_RU            2      /* Reaching uses.  */
  25 #define DF_LR            4      /* Live registers.  */
  26 #define DF_DU_CHAIN      8      /* Def-use chain.  */
  27 #define DF_UD_CHAIN     16      /* Use-def chain.  */
  28 #define DF_REG_INFO     32      /* Register info.  */
  29 #define DF_RD_CHAIN     64      /* Reg-def chain.  */
  30 #define DF_RU_CHAIN    128      /* Reg-use chain.  */
  31 #define DF_ALL         255
  32 #define DF_HARD_REGS  1024      /* Mark hard registers.  */
  33 #define DF_EQUIV_NOTES 2048     /* Mark uses present in EQUIV/EQUAL notes.  */
  34 #define DF_FOR_REGALLOC 4096    /* If called for the register allocator.  */
  35
  36 enum df_ref_type {DF_REF_REG_DEF, DF_REF_REG_USE, DF_REF_REG_MEM_LOAD,
  37                   DF_REF_REG_MEM_STORE};
  38
  39 #define DF_REF_TYPE_NAMES {"def", "use", "mem load", "mem store"}
  40
  41 /* Link on a def-use or use-def chain.  */
  42 struct df_link
  43 {
  44   struct df_link *next;
  45   struct ref *ref;
  46 };
  47
  48 enum df_ref_flags
  49   {
  50     /* Read-modify-write refs generate both a use and a def and
  51        these are marked with this flag to show that they are not
  52        independent.  */
  53     DF_REF_READ_WRITE = 1,
  54
  55     /* This flag is set on register references inside a subreg on
  56        machines which have CANNOT_CHANGE_MODE_CLASS.
  57        Note, that this flag can also be set on df_refs representing
  58        the REG itself (i.e., one might not see the subreg anymore).
  59        Also note, that this flag is set also for hardreg refs, i.e.,
  60        you must check yourself if it's a pseudo.  */
  61     DF_REF_MODE_CHANGE = 2,
  62
  63     /* This flag is set, if we stripped the subreg from the reference.
  64        In this case we must make conservative guesses, at what the
  65        outer mode was.  */
  66     DF_REF_STRIPPED = 4,
  67
  68     /* This flag is set during register allocation if it's okay for
  69     the reference's INSN to have one of its operands replaced with a
  70     memory reference.  */
  71     DF_REF_MEM_OK = 8
  72   };
  73
  74
  75 /* Define a register reference structure.  One of these is allocated
  76    for every register reference (use or def).  Note some register
  77    references (e.g., post_inc, subreg) generate both a def and a use.  */
  78 struct ref
  79 {
  80   rtx reg;                      /* The register referenced.  */
  81   rtx insn;                     /* Insn containing ref.  */
  82   rtx *loc;                     /* The location of the reg.  */
  83   struct df_link *chain;        /* Head of def-use or use-def chain.  */
  84   unsigned int id;              /* Ref index.  */
  85   enum df_ref_type type;        /* Type of ref.  */
  86   enum df_ref_flags flags;      /* Various flags.  */
  87 };
  88
  89
  90 /* One of these structures is allocated for every insn.  */
  91 struct insn_info
  92 {
  93   struct df_link *defs;         /* Head of insn-def chain.  */
  94   struct df_link *uses;         /* Head of insn-use chain.  */
  95   /* ???? The following luid field should be considered private so that
  96      we can change it on the fly to accommodate new insns?  */
  97   int luid;                     /* Logical UID.  */
  98 };
  99
 100
 101 /* One of these structures is allocated for every reg.  */
 102 struct reg_info
 103 {
 104   struct df_link *defs;         /* Head of reg-def chain.  */
 105   struct df_link *uses;         /* Head of reg-use chain.  */
 106   int lifetime;
 107   int n_defs;
 108   int n_uses;
 109 };
 110
 111
 112 /* One of these structures is allocated for every basic block.  */
 113 struct bb_info
 114 {
 115   /* Reaching def bitmaps have def_id elements.  */
 116   bitmap rd_kill;
 117   bitmap rd_gen;
 118   bitmap rd_in;
 119   bitmap rd_out;
 120   /* Reaching use bitmaps have use_id elements.  */
 121   bitmap ru_kill;
 122   bitmap ru_gen;
 123   bitmap ru_in;
 124   bitmap ru_out;
 125   /* Live variable bitmaps have n_regs elements.  */
 126   bitmap lr_def;
 127   bitmap lr_use;
 128   bitmap lr_in;
 129   bitmap lr_out;
 130   int rd_valid;
 131   int ru_valid;
 132   int lr_valid;
 133 };
 134
 135
 136 struct df
 137 {
 138   int flags;                    /* Indicates what's recorded.  */
 139   struct bb_info *bbs;          /* Basic block table.  */
 140   struct ref **defs;            /* Def table, indexed by def_id.  */
 141   struct ref **uses;            /* Use table, indexed by use_id.  */
 142   struct ref **reg_def_last;    /* Indexed by regno.  */
 143   struct reg_info *regs;        /* Regs table, index by regno.  */
 144   unsigned int reg_size;        /* Size of regs table.  */
 145   struct insn_info *insns;      /* Insn table, indexed by insn UID.  */
 146   unsigned int insn_size;       /* Size of insn table.  */
 147   unsigned int def_id;          /* Next def ID.  */
 148   unsigned int def_size;        /* Size of def table.  */
 149   unsigned int n_defs;          /* Size of def bitmaps.  */
 150   unsigned int use_id;          /* Next use ID.  */
 151   unsigned int use_size;        /* Size of use table.  */
 152   unsigned int n_uses;          /* Size of use bitmaps.  */
 153   unsigned int n_bbs;           /* Number of basic blocks.  */
 154   unsigned int n_regs;          /* Number of regs.  */
 155   unsigned int def_id_save;     /* Saved next def ID.  */
 156   unsigned int use_id_save;     /* Saved next use ID.  */
 157   bitmap insns_modified;        /* Insns that (may) have changed.  */
 158   bitmap bbs_modified;          /* Blocks that (may) have changed.  */
 159   bitmap all_blocks;            /* All blocks in CFG.  */
 160   /* The sbitmap vector of dominators or NULL if not computed.
 161      Ideally, this should be a pointer to a CFG object.  */
 162   sbitmap *dom;
 163   int *dfs_order;               /* DFS order -> block number.  */
 164   int *rc_order;                /* Reverse completion order -> block number.  */
 165   int *rts_order;               /* Reverse top sort order -> block number.  */
 166   int *inverse_rc_map;          /* Block number -> reverse completion order.  */
 167   int *inverse_dfs_map;         /* Block number -> DFS order.  */
 168   int *inverse_rts_map;         /* Block number -> reverse top-sort order.  */
 169 };
 170
 171
 172 struct df_map
 173 {
 174   rtx old;
 175   rtx new;
 176 };
 177
 178
 179 #define DF_BB_INFO(REFS, BB) (&REFS->bbs[(BB)->index])
 180
 181
 182 /* Macros to access the elements within the ref structure.  */
 183
 184 #define DF_REF_REAL_REG(REF) (GET_CODE ((REF)->reg) == SUBREG \
 185                                 ? SUBREG_REG ((REF)->reg) : ((REF)->reg))
 186 #define DF_REF_REGNO(REF) REGNO (DF_REF_REAL_REG (REF))
 187 #define DF_REF_REAL_LOC(REF) (GET_CODE ((REF)->reg) == SUBREG \
 188                                 ? &SUBREG_REG ((REF)->reg) : ((REF)->loc))
 189 #define DF_REF_REG(REF) ((REF)->reg)
 190 #define DF_REF_LOC(REF) ((REF)->loc)
 191 #define DF_REF_BB(REF) (BLOCK_FOR_INSN ((REF)->insn))
 192 #define DF_REF_BBNO(REF) (BLOCK_FOR_INSN ((REF)->insn)->index)
 193 #define DF_REF_INSN(REF) ((REF)->insn)
 194 #define DF_REF_INSN_UID(REF) (INSN_UID ((REF)->insn))
 195 #define DF_REF_TYPE(REF) ((REF)->type)
 196 #define DF_REF_CHAIN(REF) ((REF)->chain)
 197 #define DF_REF_ID(REF) ((REF)->id)
 198 #define DF_REF_FLAGS(REF) ((REF)->flags)
 199
 200 /* Macros to determine the reference type.  */
 201
 202 #define DF_REF_REG_DEF_P(REF) (DF_REF_TYPE (REF) == DF_REF_REG_DEF)
 203 #define DF_REF_REG_USE_P(REF) ((REF) && ! DF_REF_REG_DEF_P (REF))
 204 #define DF_REF_REG_MEM_STORE_P(REF) (DF_REF_TYPE (REF) == DF_REF_REG_MEM_STORE)
 205 #define DF_REF_REG_MEM_LOAD_P(REF) (DF_REF_TYPE (REF) == DF_REF_REG_MEM_LOAD)
 206 #define DF_REF_REG_MEM_P(REF) (DF_REF_REG_MEM_STORE_P (REF) \
 207                                || DF_REF_REG_MEM_LOAD_P (REF))
 208
 209
 210 /* Macros to access the elements within the reg_info structure table.  */
 211
 212 #define DF_REGNO_FIRST_DEF(DF, REGNUM) \
 213 ((DF)->regs[REGNUM].defs ? (DF)->regs[REGNUM].defs->ref : 0)
 214 #define DF_REGNO_LAST_USE(DF, REGNUM) \
 215 ((DF)->regs[REGNUM].uses ? (DF)->regs[REGNUM].uses->ref : 0)
 216
 217 #define DF_REGNO_FIRST_BB(DF, REGNUM) \
 218 (DF_REGNO_FIRST_DEF (DF, REGNUM) \
 219 ? DF_REF_BB (DF_REGNO_FIRST_DEF (DF, REGNUM)) : 0)
 220 #define DF_REGNO_LAST_BB(DF, REGNUM) \
 221 (DF_REGNO_LAST_USE (DF, REGNUM) \
 222 ? DF_REF_BB (DF_REGNO_LAST_USE (DF, REGNUM)) : 0)
 223
 224
 225 /* Macros to access the elements within the insn_info structure table.  */
 226
 227 #define DF_INSN_LUID(DF, INSN) ((DF)->insns[INSN_UID (INSN)].luid)
 228 #define DF_INSN_DEFS(DF, INSN) ((DF)->insns[INSN_UID (INSN)].defs)
 229 #define DF_INSN_USES(DF, INSN) ((DF)->insns[INSN_UID (INSN)].uses)
 230
 231
 232 /* Functions to build and analyse dataflow information.  */
 233
 234 extern struct df *df_init (void);
 235
 236 extern int df_analyze (struct df *, bitmap, int);
 237
 238 extern void df_finish (struct df *);
 239
 240 extern void df_dump (struct df *, int, FILE *);
 241
 242
 243 /* Functions to modify insns.  */
 244
 245 extern void df_insn_modify (struct df *, basic_block, rtx);
 246
 247 extern rtx df_insn_delete (struct df *, basic_block, rtx);
 248
 249 extern rtx df_pattern_emit_before (struct df *, rtx, basic_block, rtx);
 250
 251 extern rtx df_jump_pattern_emit_after (struct df *, rtx, basic_block, rtx);
 252
 253 extern rtx df_pattern_emit_after (struct df *, rtx, basic_block, rtx);
 254
 255 extern rtx df_insn_move_before (struct df *, basic_block, rtx, basic_block,
 256                                 rtx);
 257
 258 extern int df_reg_replace (struct df *, bitmap, rtx, rtx);
 259
 260 extern int df_ref_reg_replace (struct df *, struct ref *, rtx, rtx);
 261
 262 extern int df_ref_remove (struct df *, struct ref *);
 263
 264 extern int df_insn_reg_replace (struct df *, basic_block, rtx, rtx, rtx);
 265
 266 extern int df_insn_mem_replace (struct df *, basic_block, rtx, rtx, rtx);
 267
 268 extern struct ref *df_bb_def_use_swap (struct df *, basic_block, rtx, rtx,
 269                                        unsigned int);
 270
 271
 272 /* Functions to query dataflow information.  */
 273
 274 extern basic_block df_regno_bb (struct df *, unsigned int);
 275
 276 extern int df_reg_lifetime (struct df *, rtx);
 277
 278 extern int df_reg_global_p (struct df *, rtx);
 279
 280 extern int df_insn_regno_def_p (struct df *, basic_block, rtx, unsigned int);
 281
 282 extern int df_insn_dominates_all_uses_p (struct df *, basic_block, rtx);
 283
 284 extern int df_insn_dominates_uses_p (struct df *, basic_block, rtx, bitmap);
 285
 286 extern int df_bb_reg_live_start_p (struct df *, basic_block, rtx);
 287
 288 extern int df_bb_reg_live_end_p (struct df *, basic_block, rtx);
 289
 290 extern int df_bb_regs_lives_compare (struct df *, basic_block, rtx, rtx);
 291
 292 extern rtx df_bb_single_def_use_insn_find (struct df *, basic_block, rtx,
 293                                            rtx);
 294
 295
 296 /* Functions for debugging from GDB.  */
 297
 298 extern void debug_df_insn (rtx);
 299
 300 extern void debug_df_regno (unsigned int);
 301
 302 extern void debug_df_reg (rtx);
 303
 304 extern void debug_df_defno (unsigned int);
 305
 306 extern void debug_df_useno (unsigned int);
 307
 308 extern void debug_df_ref (struct ref *);
 309
 310 extern void debug_df_chain (struct df_link *);
 311
 312 extern void df_insn_debug (struct df *, rtx, FILE *);
 313
 314 extern void df_insn_debug_regno (struct df *, rtx, FILE *);
 315
 316
 317 /* Meet over any path (UNION) or meet over all paths (INTERSECTION).  */
 318 enum df_confluence_op
 319   {
 320     DF_UNION,
 321     DF_INTERSECTION
 322   };
 323
 324
 325 /* Dataflow direction.  */
 326 enum df_flow_dir
 327   {
 328     DF_FORWARD,
 329     DF_BACKWARD
 330   };
 331
 332
 333 typedef void (*transfer_function_sbitmap) (int, int *, sbitmap, sbitmap,
 334                                            sbitmap, sbitmap, void *);
 335
 336 typedef void (*transfer_function_bitmap) (int, int *, bitmap, bitmap,
 337                                           bitmap, bitmap, void *);
 338
 339 extern void iterative_dataflow_sbitmap (sbitmap *, sbitmap *, sbitmap *,
 340                                         sbitmap *, bitmap, enum df_flow_dir,
 341                                         enum df_confluence_op,
 342                                         transfer_function_sbitmap,
 343                                         int *, void *);
 344
 345 extern void iterative_dataflow_bitmap (bitmap *, bitmap *, bitmap *,
 346                                        bitmap *, bitmap,
 347                                        enum df_flow_dir,
 348                                        enum df_confluence_op,
 349                                        transfer_function_bitmap,
 350                                        int *, void *);
 351 extern bool read_modify_subreg_p (rtx);