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, 2005, 2006
   4    Free Software Foundation, Inc.
   5    Originally contributed by Michael P. Hayes
   6              (m.hayes@elec.canterbury.ac.nz, mhayes@redhat.com)
   7    Major rewrite contributed by Danny Berlin (dberlin@dberlin.org)
   8              and Kenneth Zadeck (zadeck@naturalbridge.com).
   9
  10 This file is part of GCC.
  11
  12 GCC is free software; you can redistribute it and/or modify it under
  13 the terms of the GNU General Public License as published by the Free
  14 Software Foundation; either version 2, or (at your option) any later
  15 version.
  16
  17 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  18 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  19 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  20 for more details.
  21
  22 You should have received a copy of the GNU General Public License
  23 along with GCC; see the file COPYING.  If not, write to the Free
  24 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
  25 02110-1301, USA.  */
  26
  27 #ifndef GCC_DF_H
  28 #define GCC_DF_H
  29
  30 #include "bitmap.h"
  31 #include "basic-block.h"
  32 #include "alloc-pool.h"
  33
  34 struct dataflow;
  35 struct df;
  36 struct df_problem;
  37 struct df_link;
  38
  39 /* Data flow problems.  All problems must have a unique here.  */
  40 /* Scanning is not really a dataflow problem, but it is useful to have
  41    the basic block functions in the vector so that things get done in
  42    a uniform manner.  */
  43 #define DF_SCAN  0
  44 #define DF_RU    1      /* Reaching Uses. */
  45 #define DF_RD    2      /* Reaching Defs. */
  46 #define DF_LR    3      /* Live Registers. */
  47 #define DF_UR    4      /* Uninitialized Registers. */
  48 #define DF_UREC  5      /* Uninitialized Registers with Early Clobber. */
  49 #define DF_CHAIN 6      /* Def-Use and/or Use-Def Chains. */
  50 #define DF_RI    7      /* Register Info. */
  51 #define DF_LAST_PROBLEM_PLUS1 (DF_RI + 1)
  52
  53
  54 /* Dataflow direction.  */
  55 enum df_flow_dir
  56   {
  57     DF_NONE,
  58     DF_FORWARD,
  59     DF_BACKWARD
  60   };
  61
  62
  63 /* The first of these is a set of a register.  The remaining three are
  64    all uses of a register (the mem_load and mem_store relate to how
  65    the register as an addressing operand).  */
  66 enum df_ref_type {DF_REF_REG_DEF, DF_REF_REG_USE, DF_REF_REG_MEM_LOAD,
  67                   DF_REF_REG_MEM_STORE};
  68
  69 #define DF_REF_TYPE_NAMES {"def", "use", "mem load", "mem store"}
  70
  71 enum df_ref_flags
  72   {
  73     /* Read-modify-write refs generate both a use and a def and
  74        these are marked with this flag to show that they are not
  75        independent.  */
  76     DF_REF_READ_WRITE = 1,
  77
  78     /* This flag is set, if we stripped the subreg from the reference.
  79        In this case we must make conservative guesses, at what the
  80        outer mode was.  */
  81     DF_REF_STRIPPED = 2,
  82
  83     /* If this flag is set, this is not a real definition/use, but an
  84        artificial one created to model always live registers, eh uses, etc.  */
  85     DF_REF_ARTIFICIAL = 4,
  86
  87
  88     /* If this flag is set for an artificial use or def, that ref
  89        logically happens at the top of the block.  If it is not set
  90        for an artificial use or def, that ref logically happens at the
  91        bottom of the block.  This is never set for regular refs.  */
  92     DF_REF_AT_TOP = 8,
  93
  94     /* This flag is set if the use is inside a REG_EQUAL note.  */
  95     DF_REF_IN_NOTE = 16,
  96
  97     /* This flag is set if this ref, generally a def, may clobber the
  98        referenced register.  This is generally only set for hard
  99        registers that cross a call site.  With better information
 100        about calls, some of these could be changed in the future to
 101        DF_REF_MUST_CLOBBER.  */
 102     DF_REF_MAY_CLOBBER = 32,
 103
 104     /* This flag is set if this ref, generally a def, is a real
 105        clobber. This is not currently set for registers live across a
 106        call because that clobbering may or may not happen.
 107
 108        Most of the uses of this are with sets that have a
 109        GET_CODE(..)==CLOBBER.  Note that this is set even if the
 110        clobber is to a subreg.  So in order to tell if the clobber
 111        wipes out the entire register, it is necessary to also check
 112        the DF_REF_PARTIAL flag.  */
 113     DF_REF_MUST_CLOBBER = 64,
 114
 115     /* This bit is true if this ref is part of a multiword hardreg.  */
 116     DF_REF_MW_HARDREG = 128,
 117
 118     /* This flag is set if this ref is a partial use or def of the
 119        associated register.  */
 120     DF_REF_PARTIAL = 256
 121   };
 122
 123
 124 /* Function prototypes added to df_problem instance.  */
 125
 126 /* Allocate the problem specific data.  */
 127 typedef void (*df_alloc_function) (struct dataflow *, bitmap, bitmap);
 128
 129 /* This function is called if the problem has global data that needs
 130    to be cleared when ever the set of blocks changes.  The bitmap
 131    contains the set of blocks that may require special attention.
 132    This call is only made if some of the blocks are going to change.
 133    If everything is to be deleted, the wholesale deletion mechanisms
 134    apply. */
 135 typedef void (*df_reset_function) (struct dataflow *, bitmap);
 136
 137 /* Free the basic block info.  Called from the block reordering code
 138    to get rid of the blocks that have been squished down.   */
 139 typedef void (*df_free_bb_function) (struct dataflow *, basic_block, void *);
 140
 141 /* Local compute function.  */
 142 typedef void (*df_local_compute_function) (struct dataflow *, bitmap, bitmap);
 143
 144 /* Init the solution specific data.  */
 145 typedef void (*df_init_function) (struct dataflow *, bitmap);
 146
 147 /* Iterative dataflow function.  */
 148 typedef void (*df_dataflow_function) (struct dataflow *, bitmap, bitmap,
 149                                    int *, int, bool);
 150
 151 /* Confluence operator for blocks with 0 out (or in) edges.  */
 152 typedef void (*df_confluence_function_0) (struct dataflow *, basic_block);
 153
 154 /* Confluence operator for blocks with 1 or more out (or in) edges.  */
 155 typedef void (*df_confluence_function_n) (struct dataflow *, edge);
 156
 157 /* Transfer function for blocks.  */
 158 typedef bool (*df_transfer_function) (struct dataflow *, int);
 159
 160 /* Function to massage the information after the problem solving.  */
 161 typedef void (*df_finalizer_function) (struct dataflow*, bitmap);
 162
 163 /* Function to free all of the problem specific datastructures.  */
 164 typedef void (*df_free_function) (struct dataflow *);
 165
 166 /* Function to dump results to FILE.  */
 167 typedef void (*df_dump_problem_function) (struct dataflow *, FILE *);
 168
 169 /* Function to add problem a dataflow problem that must be solved
 170    before this problem can be solved.  */
 171 typedef struct dataflow * (*df_dependent_problem_function) (struct df *, int);
 172
 173 /* The static description of a dataflow problem to solve.  See above
 174    typedefs for doc for the function fields.  */
 175
 176 struct df_problem {
 177   /* The unique id of the problem.  This is used it index into
 178      df->defined_problems to make accessing the problem data easy.  */
 179   unsigned int id;
 180   enum df_flow_dir dir;                 /* Dataflow direction.  */
 181   df_alloc_function alloc_fun;
 182   df_reset_function reset_fun;
 183   df_free_bb_function free_bb_fun;
 184   df_local_compute_function local_compute_fun;
 185   df_init_function init_fun;
 186   df_dataflow_function dataflow_fun;
 187   df_confluence_function_0 con_fun_0;
 188   df_confluence_function_n con_fun_n;
 189   df_transfer_function trans_fun;
 190   df_finalizer_function finalize_fun;
 191   df_free_function free_fun;
 192   df_dump_problem_function dump_fun;
 193   df_dependent_problem_function dependent_problem_fun;
 194
 195   /* Flags can be changed after analysis starts.  */
 196   int changeable_flags;
 197 };
 198
 199
 200 /* The specific instance of the problem to solve.  */
 201 struct dataflow
 202 {
 203   struct df *df;                        /* Instance of df we are working in.  */
 204   struct df_problem *problem;           /* The problem to be solved.  */
 205
 206   /* Communication between iterative_dataflow and hybrid_search. */
 207   sbitmap visited, pending, considered;
 208
 209   /* Array indexed by bb->index, that contains basic block problem and
 210      solution specific information.  */
 211   void **block_info;
 212   unsigned int block_info_size;
 213
 214   /* The pool to allocate the block_info from. */
 215   alloc_pool block_pool;
 216
 217   /* Problem specific control information.  */
 218
 219   /* Scanning flags.  */
 220 #define DF_HARD_REGS         1  /* Mark hard registers.  */
 221 #define DF_EQUIV_NOTES       2  /* Mark uses present in EQUIV/EQUAL notes.  */
 222 #define DF_SUBREGS           4  /* Return subregs rather than the inner reg.  */
 223   /* Flags that control the building of chains.  */
 224 #define DF_DU_CHAIN          1    /* Build DU chains.  */
 225 #define DF_UD_CHAIN          2    /* Build UD chains.  */
 226   /* Flag to control the building of register info.  */
 227 #define DF_RI_LIFE           1    /* Build register info.  */
 228
 229   int flags;
 230
 231   /* Other problem specific data that is not on a per basic block
 232      basis.  The structure is generally defined privately for the
 233      problem.  The exception being the scanning problem where it is
 234      fully public.  */
 235   void *problem_data;
 236 };
 237
 238
 239 /* The set of multiword hardregs used as operands to this
 240    instruction. These are factored into individual uses and defs but
 241    the aggregate is still needed to service the REG_DEAD and
 242    REG_UNUSED notes.  */
 243 struct df_mw_hardreg
 244 {
 245   rtx mw_reg;                   /* The multiword hardreg.  */
 246   enum df_ref_type type;        /* Used to see if the ref is read or write.  */
 247   enum df_ref_flags flags;      /* Various flags.  */
 248   struct df_link *regs;         /* The individual regs that make up
 249                                    this hardreg.  */
 250   struct df_mw_hardreg *next;   /* The next mw_hardreg in this insn.  */
 251 };
 252
 253
 254 /* One of these structures is allocated for every insn.  */
 255 struct df_insn_info
 256 {
 257   struct df_ref *defs;          /* Head of insn-def chain.  */
 258   struct df_ref *uses;          /* Head of insn-use chain.  */
 259   struct df_mw_hardreg *mw_hardregs;
 260   /* ???? The following luid field should be considered private so that
 261      we can change it on the fly to accommodate new insns?  */
 262   int luid;                     /* Logical UID.  */
 263   bool contains_asm;            /* Contains an asm instruction.  */
 264 };
 265
 266
 267 /* Two of these structures are allocated for every pseudo reg, one for
 268    the uses and one for the defs.  */
 269 struct df_reg_info
 270 {
 271   struct df_ref *reg_chain;     /* Head of reg-use or def chain.  */
 272   unsigned int begin;           /* First def_index for this pseudo.  */
 273   unsigned int n_refs;          /* Number of refs or defs for this pseudo.  */
 274 };
 275
 276 /* Define a register reference structure.  One of these is allocated
 277    for every register reference (use or def).  Note some register
 278    references (e.g., post_inc, subreg) generate both a def and a use.  */
 279 struct df_ref
 280 {
 281   rtx reg;                      /* The register referenced.  */
 282   unsigned int regno;           /* The register number referenced.  */
 283   basic_block bb;               /* Basic block containing the instruction. */
 284
 285   /* Insn containing ref. This will be null if this is an artificial
 286      reference.  */
 287   rtx insn;
 288   rtx *loc;                     /* The location of the reg.  */
 289   struct df_link *chain;        /* Head of def-use, use-def.  */
 290   unsigned int id;              /* Location in table.  */
 291   enum df_ref_type type;        /* Type of ref.  */
 292   enum df_ref_flags flags;      /* Various flags.  */
 293
 294   /* For each regno, there are two chains of refs, one for the uses
 295      and one for the defs.  These chains go thru the refs themselves
 296      rather than using an external structure.  */
 297   struct df_ref *next_reg;     /* Next ref with same regno and type.  */
 298   struct df_ref *prev_reg;     /* Prev ref with same regno and type.  */
 299
 300   /* Each insn has two lists, one for the uses and one for the
 301      defs. This is the next field in either of these chains. */
 302   struct df_ref *next_ref;
 303   void *data;                   /* The data assigned to it by user.  */
 304 };
 305
 306 /* These links are used for two purposes:
 307    1) def-use or use-def chains.
 308    2) Multiword hard registers that underly a single hardware register.  */
 309 struct df_link
 310 {
 311   struct df_ref *ref;
 312   struct df_link *next;
 313 };
 314
 315 /* Two of these structures are allocated, one for the uses and one for
 316    the defs.  */
 317 struct df_ref_info
 318 {
 319   struct df_reg_info **regs;    /* Array indexed by pseudo regno. */
 320   unsigned int regs_size;       /* Size of currently allocated regs table.  */
 321   unsigned int regs_inited;     /* Number of regs with reg_infos allocated.  */
 322   struct df_ref **refs;         /* Ref table, indexed by id.  */
 323   unsigned int refs_size;       /* Size of currently allocated refs table.  */
 324   unsigned int bitmap_size;     /* Number of refs seen.  */
 325
 326   /* True if refs table is organized so that every reference for a
 327      pseudo is contiguous.  */
 328   bool refs_organized;
 329   /* True if the next refs should be added immediately or false to
 330      defer to later to reorganize the table.  */
 331   bool add_refs_inline;
 332 };
 333
 334 \f
 335 /*----------------------------------------------------------------------------
 336    Problem data for the scanning dataflow problem.  Unlike the other
 337    dataflow problems, the problem data for scanning is fully exposed and
 338    used by owners of the problem.
 339 ----------------------------------------------------------------------------*/
 340
 341 struct df
 342 {
 343
 344   /* The set of problems to be solved is stored in two arrays.  In
 345      PROBLEMS_IN_ORDER, the problems are stored in the order that they
 346      are solved.  This is an internally dense array that may have
 347      nulls at the end of it.  In PROBLEMS_BY_INDEX, the problem is
 348      stored by the value in df_problem.id.  These are used to access
 349      the problem local data without having to search the first
 350      array.  */
 351
 352   struct dataflow *problems_in_order [DF_LAST_PROBLEM_PLUS1];
 353   struct dataflow *problems_by_index [DF_LAST_PROBLEM_PLUS1];
 354   int num_problems_defined;
 355
 356   /* Set after calls to df_scan_blocks, this contains all of the
 357      blocks that higher level problems must rescan before solving the
 358      dataflow equations.  If this is NULL, the blocks_to_analyze is
 359      used. */
 360   bitmap blocks_to_scan;
 361
 362   /* If not NULL, the subset of blocks of the program to be considered
 363      for analysis.  */
 364   bitmap blocks_to_analyze;
 365
 366   /* The following information is really the problem data for the
 367      scanning instance but it is used too often by the other problems
 368      to keep getting it from there.  */
 369   struct df_ref_info def_info;   /* Def info.  */
 370   struct df_ref_info use_info;   /* Use info.  */
 371   struct df_insn_info **insns;   /* Insn table, indexed by insn UID.  */
 372   unsigned int insns_size;       /* Size of insn table.  */
 373   bitmap hardware_regs_used;     /* The set of hardware registers used.  */
 374   bitmap entry_block_defs;       /* The set of hardware registers live on entry to the function.  */
 375   bitmap exit_block_uses;        /* The set of hardware registers used in exit block.  */
 376 };
 377
 378 #define DF_SCAN_BB_INFO(DF, BB) (df_scan_get_bb_info((DF)->problems_by_index[DF_SCAN],(BB)->index))
 379 #define DF_RU_BB_INFO(DF, BB) (df_ru_get_bb_info((DF)->problems_by_index[DF_RU],(BB)->index))
 380 #define DF_RD_BB_INFO(DF, BB) (df_rd_get_bb_info((DF)->problems_by_index[DF_RD],(BB)->index))
 381 #define DF_LR_BB_INFO(DF, BB) (df_lr_get_bb_info((DF)->problems_by_index[DF_LR],(BB)->index))
 382 #define DF_UR_BB_INFO(DF, BB) (df_ur_get_bb_info((DF)->problems_by_index[DF_UR],(BB)->index))
 383 #define DF_UREC_BB_INFO(DF, BB) (df_urec_get_bb_info((DF)->problems_by_index[DF_UREC],(BB)->index))
 384
 385 /* Most transformations that wish to use live register analysis will
 386    use these macros.  The DF_UPWARD_LIVE* macros are only half of the
 387    solution.  */
 388 #define DF_LIVE_IN(DF, BB) (DF_UR_BB_INFO(DF, BB)->in)
 389 #define DF_LIVE_OUT(DF, BB) (DF_UR_BB_INFO(DF, BB)->out)
 390
 391
 392 /* Live in for register allocation also takes into account several other factors.  */
 393 #define DF_RA_LIVE_IN(DF, BB) (DF_UREC_BB_INFO(DF, BB)->in)
 394 #define DF_RA_LIVE_OUT(DF, BB) (DF_UREC_BB_INFO(DF, BB)->out)
 395
 396 /* These macros are currently used by only reg-stack since it is not
 397    tolerant of uninitialized variables.  This intolerance should be
 398    fixed because it causes other problems.  */
 399 #define DF_UPWARD_LIVE_IN(DF, BB) (DF_LR_BB_INFO(DF, BB)->in)
 400 #define DF_UPWARD_LIVE_OUT(DF, BB) (DF_LR_BB_INFO(DF, BB)->out)
 401
 402
 403 /* Macros to access the elements within the ref structure.  */
 404
 405
 406 #define DF_REF_REAL_REG(REF) (GET_CODE ((REF)->reg) == SUBREG \
 407                                 ? SUBREG_REG ((REF)->reg) : ((REF)->reg))
 408 #define DF_REF_REGNO(REF) ((REF)->regno)
 409 #define DF_REF_REAL_LOC(REF) (GET_CODE ((REF)->reg) == SUBREG \
 410                                 ? &SUBREG_REG ((REF)->reg) : ((REF)->loc))
 411 #define DF_REF_REG(REF) ((REF)->reg)
 412 #define DF_REF_LOC(REF) ((REF)->loc)
 413 #define DF_REF_BB(REF) ((REF)->bb)
 414 #define DF_REF_BBNO(REF) (DF_REF_BB (REF)->index)
 415 #define DF_REF_INSN(REF) ((REF)->insn)
 416 #define DF_REF_INSN_UID(REF) (INSN_UID ((REF)->insn))
 417 #define DF_REF_TYPE(REF) ((REF)->type)
 418 #define DF_REF_CHAIN(REF) ((REF)->chain)
 419 #define DF_REF_ID(REF) ((REF)->id)
 420 #define DF_REF_FLAGS(REF) ((REF)->flags)
 421 #define DF_REF_NEXT_REG(REF) ((REF)->next_reg)
 422 #define DF_REF_PREV_REG(REF) ((REF)->prev_reg)
 423 #define DF_REF_NEXT_REF(REF) ((REF)->next_ref)
 424 #define DF_REF_DATA(REF) ((REF)->data)
 425
 426 /* Macros to determine the reference type.  */
 427
 428 #define DF_REF_REG_DEF_P(REF) (DF_REF_TYPE (REF) == DF_REF_REG_DEF)
 429 #define DF_REF_REG_USE_P(REF) ((REF) && !DF_REF_REG_DEF_P (REF))
 430 #define DF_REF_REG_MEM_STORE_P(REF) (DF_REF_TYPE (REF) == DF_REF_REG_MEM_STORE)
 431 #define DF_REF_REG_MEM_LOAD_P(REF) (DF_REF_TYPE (REF) == DF_REF_REG_MEM_LOAD)
 432 #define DF_REF_REG_MEM_P(REF) (DF_REF_REG_MEM_STORE_P (REF) \
 433                                || DF_REF_REG_MEM_LOAD_P (REF))
 434
 435 /* Macros to get the refs out of def_info or use_info refs table.  */
 436 #define DF_DEFS_SIZE(DF) ((DF)->def_info.bitmap_size)
 437 #define DF_DEFS_GET(DF,ID) ((DF)->def_info.refs[(ID)])
 438 #define DF_DEFS_SET(DF,ID,VAL) ((DF)->def_info.refs[(ID)]=(VAL))
 439 #define DF_USES_SIZE(DF) ((DF)->use_info.bitmap_size)
 440 #define DF_USES_GET(DF,ID) ((DF)->use_info.refs[(ID)])
 441 #define DF_USES_SET(DF,ID,VAL) ((DF)->use_info.refs[(ID)]=(VAL))
 442
 443 /* Macros to access the register information from scan dataflow record.  */
 444
 445 #define DF_REG_SIZE(DF) ((DF)->def_info.regs_inited)
 446 #define DF_REG_DEF_GET(DF, REG) ((DF)->def_info.regs[(REG)])
 447 #define DF_REG_DEF_SET(DF, REG, VAL) ((DF)->def_info.regs[(REG)]=(VAL))
 448 #define DF_REG_DEF_COUNT(DF, REG) ((DF)->def_info.regs[(REG)]->n_refs)
 449 #define DF_REG_USE_GET(DF, REG) ((DF)->use_info.regs[(REG)])
 450 #define DF_REG_USE_SET(DF, REG, VAL) ((DF)->use_info.regs[(REG)]=(VAL))
 451 #define DF_REG_USE_COUNT(DF, REG) ((DF)->use_info.regs[(REG)]->n_refs)
 452
 453 /* Macros to access the elements within the reg_info structure table.  */
 454
 455 #define DF_REGNO_FIRST_DEF(DF, REGNUM) \
 456 (DF_REG_DEF_GET(DF, REGNUM) ? DF_REG_DEF_GET(DF, REGNUM) : 0)
 457 #define DF_REGNO_LAST_USE(DF, REGNUM) \
 458 (DF_REG_USE_GET(DF, REGNUM) ? DF_REG_USE_GET(DF, REGNUM) : 0)
 459
 460 /* Macros to access the elements within the insn_info structure table.  */
 461
 462 #define DF_INSN_SIZE(DF) ((DF)->insns_size)
 463 #define DF_INSN_GET(DF,INSN) ((DF)->insns[(INSN_UID(INSN))])
 464 #define DF_INSN_SET(DF,INSN,VAL) ((DF)->insns[(INSN_UID (INSN))]=(VAL))
 465 #define DF_INSN_CONTAINS_ASM(DF, INSN) (DF_INSN_GET(DF,INSN)->contains_asm)
 466 #define DF_INSN_LUID(DF, INSN) (DF_INSN_GET(DF,INSN)->luid)
 467 #define DF_INSN_DEFS(DF, INSN) (DF_INSN_GET(DF,INSN)->defs)
 468 #define DF_INSN_USES(DF, INSN) (DF_INSN_GET(DF,INSN)->uses)
 469
 470 #define DF_INSN_UID_GET(DF,UID) ((DF)->insns[(UID)])
 471 #define DF_INSN_UID_LUID(DF, INSN) (DF_INSN_UID_GET(DF,INSN)->luid)
 472 #define DF_INSN_UID_DEFS(DF, INSN) (DF_INSN_UID_GET(DF,INSN)->defs)
 473 #define DF_INSN_UID_USES(DF, INSN) (DF_INSN_UID_GET(DF,INSN)->uses)
 474 #define DF_INSN_UID_MWS(DF, INSN) (DF_INSN_UID_GET(DF,INSN)->mw_hardregs)
 475
 476 /* This is a bitmap copy of regs_invalidated_by_call so that we can
 477    easily add it into bitmaps, etc. */
 478
 479 extern bitmap df_invalidated_by_call;
 480
 481
 482 /* One of these structures is allocated for every basic block.  */
 483 struct df_scan_bb_info
 484 {
 485   /* Defs at the start of a basic block that is the target of an
 486      exception edge.  */
 487   struct df_ref *artificial_defs;
 488
 489   /* Uses of hard registers that are live at every block.  */
 490   struct df_ref *artificial_uses;
 491 };
 492
 493
 494 /* Reaching uses.  All bitmaps are indexed by the id field of the ref
 495    except sparse_kill (see below).  */
 496 struct df_ru_bb_info
 497 {
 498   /* Local sets to describe the basic blocks.  */
 499   /* The kill set is the set of uses that are killed in this block.
 500      However, if the number of uses for this register is greater than
 501      DF_SPARSE_THRESHOLD, the sparse_kill is used instead. In
 502      sparse_kill, each register gets a slot and a 1 in this bitvector
 503      means that all of the uses of that register are killed.  This is
 504      a very useful efficiency hack in that it keeps from having push
 505      around big groups of 1s.  This is implemented by the
 506      bitmap_clear_range call.  */
 507
 508   bitmap kill;
 509   bitmap sparse_kill;
 510   bitmap gen;   /* The set of uses generated in this block.  */
 511
 512   /* The results of the dataflow problem.  */
 513   bitmap in;    /* At the top of the block.  */
 514   bitmap out;   /* At the bottom of the block.  */
 515 };
 516
 517
 518 /* Reaching definitions.  All bitmaps are indexed by the id field of
 519    the ref except sparse_kill (see above).  */
 520 struct df_rd_bb_info
 521 {
 522   /* Local sets to describe the basic blocks.  See the note in the RU
 523      datastructures for kill and sparse_kill.  */
 524   bitmap kill;
 525   bitmap sparse_kill;
 526   bitmap gen;   /* The set of defs generated in this block.  */
 527
 528   /* The results of the dataflow problem.  */
 529   bitmap in;    /* At the top of the block.  */
 530   bitmap out;   /* At the bottom of the block.  */
 531 };
 532
 533
 534 /* Live registers.  All bitmaps are referenced by the register number.  */
 535 struct df_lr_bb_info
 536 {
 537   /* Local sets to describe the basic blocks.  */
 538   bitmap def;   /* The set of registers set in this block.  */
 539   bitmap use;   /* The set of registers used in this block.  */
 540
 541   /* The results of the dataflow problem.  */
 542   bitmap in;    /* At the top of the block.  */
 543   bitmap out;   /* At the bottom of the block.  */
 544 };
 545
 546
 547 /* Uninitialized registers.  All bitmaps are referenced by the register number.  */
 548 struct df_ur_bb_info
 549 {
 550   /* Local sets to describe the basic blocks.  */
 551   bitmap kill;  /* The set of registers unset in this block.  Calls,
 552                    for instance, unset registers.  */
 553   bitmap gen;   /* The set of registers set in this block.  */
 554
 555   /* The results of the dataflow problem.  */
 556   bitmap in;    /* At the top of the block.  */
 557   bitmap out;   /* At the bottom of the block.  */
 558 };
 559
 560 /* Uninitialized registers.  All bitmaps are referenced by the register number.  */
 561 struct df_urec_bb_info
 562 {
 563   /* Local sets to describe the basic blocks.  */
 564   bitmap earlyclobber;  /* The set of registers that are referenced
 565                            with an early clobber mode.  */
 566   /* Kill and gen are defined as in the UR problem.  */
 567   bitmap kill;
 568   bitmap gen;
 569
 570   /* The results of the dataflow problem.  */
 571   bitmap in;    /* At the top of the block.  */
 572   bitmap out;   /* At the bottom of the block.  */
 573 };
 574
 575
 576 #define df_finish(df) {df_finish1(df); df=NULL;}
 577
 578 /* Functions defined in df-core.c.  */
 579
 580 extern struct df *df_init (int);
 581 extern struct dataflow *df_add_problem (struct df *, struct df_problem *, int);
 582 extern int df_set_flags (struct dataflow *, int);
 583 extern int df_clear_flags (struct dataflow *, int);
 584 extern void df_set_blocks (struct df*, bitmap);
 585 extern void df_delete_basic_block (struct df *, int);
 586 extern void df_finish1 (struct df *);
 587 extern void df_analyze_problem (struct dataflow *, bitmap, bitmap, bitmap, int *, int, bool);
 588 extern void df_analyze (struct df *);
 589 extern void df_compact_blocks (struct df *);
 590 extern void df_bb_replace (struct df *, int, basic_block);
 591 extern struct df_ref *df_bb_regno_last_use_find (struct df *, basic_block, unsigned int);
 592 extern struct df_ref *df_bb_regno_first_def_find (struct df *, basic_block, unsigned int);
 593 extern struct df_ref *df_bb_regno_last_def_find (struct df *, basic_block, unsigned int);
 594 extern bool df_insn_regno_def_p (struct df *, rtx, unsigned int);
 595 extern struct df_ref *df_find_def (struct df *, rtx, rtx);
 596 extern bool df_reg_defined (struct df *, rtx, rtx);
 597 extern struct df_ref *df_find_use (struct df *, rtx, rtx);
 598 extern bool df_reg_used (struct df *, rtx, rtx);
 599 extern void df_iterative_dataflow (struct dataflow *, bitmap, bitmap, int *, int, bool);
 600 extern void df_dump (struct df *, FILE *);
 601 extern void df_refs_chain_dump (struct df_ref *, bool, FILE *);
 602 extern void df_regs_chain_dump (struct df *, struct df_ref *,  FILE *);
 603 extern void df_insn_debug (struct df *, rtx, bool, FILE *);
 604 extern void df_insn_debug_regno (struct df *, rtx, FILE *);
 605 extern void df_regno_debug (struct df *, unsigned int, FILE *);
 606 extern void df_ref_debug (struct df_ref *, FILE *);
 607 extern void debug_df_insn (rtx);
 608 extern void debug_df_regno (unsigned int);
 609 extern void debug_df_reg (rtx);
 610 extern void debug_df_defno (unsigned int);
 611 extern void debug_df_useno (unsigned int);
 612 extern void debug_df_ref (struct df_ref *);
 613 extern void debug_df_chain (struct df_link *);
 614 /* An instance of df that can be shared between passes.  */
 615 extern struct df *shared_df;
 616
 617
 618 /* Functions defined in df-problems.c. */
 619
 620 extern struct df_link *df_chain_create (struct dataflow *, struct df_ref *, struct df_ref *);
 621 extern void df_chain_unlink (struct dataflow *, struct df_ref *, struct df_link *);
 622 extern void df_chain_copy (struct dataflow *, struct df_ref *, struct df_link *);
 623 extern bitmap df_get_live_in (struct df *, basic_block);
 624 extern bitmap df_get_live_out (struct df *, basic_block);
 625 extern void df_grow_bb_info (struct dataflow *);
 626 extern void df_chain_dump (struct df_link *, FILE *);
 627 extern void df_print_bb_index (basic_block bb, FILE *file);
 628 extern struct dataflow *df_ru_add_problem (struct df *, int);
 629 extern struct df_ru_bb_info *df_ru_get_bb_info (struct dataflow *, unsigned int);
 630 extern struct dataflow *df_rd_add_problem (struct df *, int);
 631 extern struct df_rd_bb_info *df_rd_get_bb_info (struct dataflow *, unsigned int);
 632 extern struct dataflow *df_lr_add_problem (struct df *, int);
 633 extern struct df_lr_bb_info *df_lr_get_bb_info (struct dataflow *, unsigned int);
 634 extern struct dataflow *df_ur_add_problem (struct df *, int);
 635 extern struct df_ur_bb_info *df_ur_get_bb_info (struct dataflow *, unsigned int);
 636 extern struct dataflow *df_urec_add_problem (struct df *, int);
 637 extern struct df_urec_bb_info *df_urec_get_bb_info (struct dataflow *, unsigned int);
 638 extern struct dataflow *df_chain_add_problem (struct df *, int);
 639 extern struct dataflow *df_ri_add_problem (struct df *, int);
 640
 641
 642 /* Functions defined in df-scan.c.  */
 643
 644 extern struct df_scan_bb_info *df_scan_get_bb_info (struct dataflow *, unsigned int);
 645 extern struct dataflow *df_scan_add_problem (struct df *, int);
 646 extern void df_rescan_blocks (struct df *, bitmap);
 647 extern struct df_ref *df_ref_create (struct df *, rtx, rtx *, rtx,basic_block,enum df_ref_type, enum df_ref_flags);
 648 extern struct df_ref *df_get_artificial_defs (struct df *, unsigned int);
 649 extern struct df_ref *df_get_artificial_uses (struct df *, unsigned int);
 650 extern void df_reg_chain_create (struct df_reg_info *, struct df_ref *);
 651 extern struct df_ref *df_reg_chain_unlink (struct dataflow *, struct df_ref *);
 652 extern void df_ref_remove (struct df *, struct df_ref *);
 653 extern void df_insn_refs_delete (struct dataflow *, rtx);
 654 extern void df_bb_refs_delete (struct dataflow *, int);
 655 extern void df_refs_delete (struct dataflow *, bitmap);
 656 extern void df_reorganize_refs (struct df_ref_info *);
 657 extern void df_hard_reg_init (void);
 658 extern bool df_read_modify_subreg_p (rtx);
 659
 660
 661 /* web */
 662
 663 /* This entry is allocated for each reference in the insn stream.  */
 664 struct web_entry
 665 {
 666   /* Pointer to the parent in the union/find tree.  */
 667   struct web_entry *pred;
 668   /* Newly assigned register to the entry.  Set only for roots.  */
 669   rtx reg;
 670   void* extra_info;
 671 };
 672
 673 extern struct web_entry *unionfind_root (struct web_entry *);
 674 extern bool unionfind_union (struct web_entry *, struct web_entry *);
 675 extern void union_defs (struct df *, struct df_ref *,
 676                         struct web_entry *, struct web_entry *,
 677                         bool (*fun) (struct web_entry *, struct web_entry *));
 678
 679
 680 #endif /* GCC_DF_H */