gcc/sched-int.h

   1 /* Instruction scheduling pass.  This file contains definitions used
   2    internally in the scheduler.
   3    Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998,
   4    1999, 2000, 2001 Free Software Foundation, Inc.
   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 /* Pointer to data describing the current DFA state.  */
  24 extern state_t curr_state;
  25
  26 /* Forward declaration.  */
  27 struct ready_list;
  28
  29 /* Describe state of dependencies used during sched_analyze phase.  */
  30 struct deps
  31 {
  32   /* The *_insns and *_mems are paired lists.  Each pending memory operation
  33      will have a pointer to the MEM rtx on one list and a pointer to the
  34      containing insn on the other list in the same place in the list.  */
  35
  36   /* We can't use add_dependence like the old code did, because a single insn
  37      may have multiple memory accesses, and hence needs to be on the list
  38      once for each memory access.  Add_dependence won't let you add an insn
  39      to a list more than once.  */
  40
  41   /* An INSN_LIST containing all insns with pending read operations.  */
  42   rtx pending_read_insns;
  43
  44   /* An EXPR_LIST containing all MEM rtx's which are pending reads.  */
  45   rtx pending_read_mems;
  46
  47   /* An INSN_LIST containing all insns with pending write operations.  */
  48   rtx pending_write_insns;
  49
  50   /* An EXPR_LIST containing all MEM rtx's which are pending writes.  */
  51   rtx pending_write_mems;
  52
  53   /* Indicates the combined length of the two pending lists.  We must prevent
  54      these lists from ever growing too large since the number of dependencies
  55      produced is at least O(N*N), and execution time is at least O(4*N*N), as
  56      a function of the length of these pending lists.  */
  57   int pending_lists_length;
  58
  59   /* Length of the pending memory flush list. Large functions with no
  60      calls may build up extremely large lists.  */
  61   int pending_flush_length;
  62
  63   /* The last insn upon which all memory references must depend.
  64      This is an insn which flushed the pending lists, creating a dependency
  65      between it and all previously pending memory references.  This creates
  66      a barrier (or a checkpoint) which no memory reference is allowed to cross.
  67
  68      This includes all non constant CALL_INSNs.  When we do interprocedural
  69      alias analysis, this restriction can be relaxed.
  70      This may also be an INSN that writes memory if the pending lists grow
  71      too large.  */
  72   rtx last_pending_memory_flush;
  73
  74   /* A list of the last function calls we have seen.  We use a list to
  75      represent last function calls from multiple predecessor blocks.
  76      Used to prevent register lifetimes from expanding unnecessarily.  */
  77   rtx last_function_call;
  78
  79   /* A list of insns which use a pseudo register that does not already
  80      cross a call.  We create dependencies between each of those insn
  81      and the next call insn, to ensure that they won't cross a call after
  82      scheduling is done.  */
  83   rtx sched_before_next_call;
  84
  85   /* Used to keep post-call psuedo/hard reg movements together with
  86      the call.  */
  87   bool in_post_call_group_p;
  88
  89   /* The maximum register number for the following arrays.  Before reload
  90      this is max_reg_num; after reload it is FIRST_PSEUDO_REGISTER.  */
  91   int max_reg;
  92
  93   /* Element N is the next insn that sets (hard or pseudo) register
  94      N within the current basic block; or zero, if there is no
  95      such insn.  Needed for new registers which may be introduced
  96      by splitting insns.  */
  97   struct deps_reg
  98     {
  99       rtx uses;
 100       rtx sets;
 101       rtx clobbers;
 102       int uses_length;
 103       int clobbers_length;
 104     } *reg_last;
 105
 106   /* Element N is set for each register that has any non-zero element
 107      in reg_last[N].{uses,sets,clobbers}.  */
 108   regset_head reg_last_in_use;
 109 };
 110
 111 /* This structure holds some state of the current scheduling pass, and
 112    contains some function pointers that abstract out some of the non-generic
 113    functionality from functions such as schedule_block or schedule_insn.
 114    There is one global variable, current_sched_info, which points to the
 115    sched_info structure currently in use.  */
 116 struct sched_info
 117 {
 118   /* Add all insns that are initially ready to the ready list.  Called once
 119      before scheduling a set of insns.  */
 120   void (*init_ready_list) PARAMS ((struct ready_list *));
 121   /* Called after taking an insn from the ready list.  Returns nonzero if
 122      this insn can be scheduled, nonzero if we should silently discard it.  */
 123   int (*can_schedule_ready_p) PARAMS ((rtx));
 124   /* Return nonzero if there are more insns that should be scheduled.  */
 125   int (*schedule_more_p) PARAMS ((void));
 126   /* Called after an insn has all its dependencies resolved.  Return nonzero
 127      if it should be moved to the ready list or the queue, or zero if we
 128      should silently discard it.  */
 129   int (*new_ready) PARAMS ((rtx));
 130   /* Compare priority of two insns.  Return a positive number if the second
 131      insn is to be preferred for scheduling, and a negative one if the first
 132      is to be preferred.  Zero if they are equally good.  */
 133   int (*rank) PARAMS ((rtx, rtx));
 134   /* Return a string that contains the insn uid and optionally anything else
 135      necessary to identify this insn in an output.  It's valid to use a
 136      static buffer for this.  The ALIGNED parameter should cause the string
 137      to be formatted so that multiple output lines will line up nicely.  */
 138   const char *(*print_insn) PARAMS ((rtx, int));
 139   /* Return nonzero if an insn should be included in priority
 140      calculations.  */
 141   int (*contributes_to_priority) PARAMS ((rtx, rtx));
 142   /* Called when computing dependencies for a JUMP_INSN.  This function
 143      should store the set of registers that must be considered as set by
 144      the jump in the regset.  */
 145   void (*compute_jump_reg_dependencies) PARAMS ((rtx, regset));
 146
 147   /* The boundaries of the set of insns to be scheduled.  */
 148   rtx prev_head, next_tail;
 149
 150   /* Filled in after the schedule is finished; the first and last scheduled
 151      insns.  */
 152   rtx head, tail;
 153
 154   /* If nonzero, enables an additional sanity check in schedule_block.  */
 155   unsigned int queue_must_finish_empty:1;
 156   /* Nonzero if we should use cselib for better alias analysis.  This
 157      must be 0 if the dependency information is used after sched_analyze
 158      has completed, e.g. if we're using it to initialize state for successor
 159      blocks in region scheduling.  */
 160   unsigned int use_cselib:1;
 161 };
 162
 163 extern struct sched_info *current_sched_info;
 164
 165 /* Indexed by INSN_UID, the collection of all data associated with
 166    a single instruction.  */
 167
 168 struct haifa_insn_data
 169 {
 170   /* A list of insns which depend on the instruction.  Unlike LOG_LINKS,
 171      it represents forward dependencies.  */
 172   rtx depend;
 173
 174   /* The line number note in effect for each insn.  For line number
 175      notes, this indicates whether the note may be reused.  */
 176   rtx line_note;
 177
 178   /* Logical uid gives the original ordering of the insns.  */
 179   int luid;
 180
 181   /* A priority for each insn.  */
 182   int priority;
 183
 184   /* The number of incoming edges in the forward dependency graph.
 185      As scheduling proceds, counts are decreased.  An insn moves to
 186      the ready queue when its counter reaches zero.  */
 187   int dep_count;
 188
 189   /* An encoding of the blockage range function.  Both unit and range
 190      are coded.  This member is used only for old pipeline interface.  */
 191   unsigned int blockage;
 192
 193   /* Number of instructions referring to this insn.  */
 194   int ref_count;
 195
 196   /* The minimum clock tick at which the insn becomes ready.  This is
 197      used to note timing constraints for the insns in the pending list.  */
 198   int tick;
 199
 200   short cost;
 201
 202   /* An encoding of the function units used.  This member is used only
 203      for old pipeline interface.  */
 204   short units;
 205
 206   /* This weight is an estimation of the insn's contribution to
 207      register pressure.  */
 208   short reg_weight;
 209
 210   /* Some insns (e.g. call) are not allowed to move across blocks.  */
 211   unsigned int cant_move : 1;
 212
 213   /* Set if there's DEF-USE dependence between some speculatively
 214      moved load insn and this one.  */
 215   unsigned int fed_by_spec_load : 1;
 216   unsigned int is_load_insn : 1;
 217
 218   /* Nonzero if priority has been computed already.  */
 219   unsigned int priority_known : 1;
 220 };
 221
 222 extern struct haifa_insn_data *h_i_d;
 223
 224 /* Accessor macros for h_i_d.  There are more in haifa-sched.c and
 225    sched-rgn.c.  */
 226 #define INSN_DEPEND(INSN)       (h_i_d[INSN_UID (INSN)].depend)
 227 #define INSN_LUID(INSN)         (h_i_d[INSN_UID (INSN)].luid)
 228 #define CANT_MOVE(insn)         (h_i_d[INSN_UID (insn)].cant_move)
 229 #define INSN_DEP_COUNT(INSN)    (h_i_d[INSN_UID (INSN)].dep_count)
 230 #define INSN_PRIORITY(INSN)     (h_i_d[INSN_UID (INSN)].priority)
 231 #define INSN_PRIORITY_KNOWN(INSN) (h_i_d[INSN_UID (INSN)].priority_known)
 232 #define INSN_COST(INSN)         (h_i_d[INSN_UID (INSN)].cost)
 233 #define INSN_UNIT(INSN)         (h_i_d[INSN_UID (INSN)].units)
 234 #define INSN_REG_WEIGHT(INSN)   (h_i_d[INSN_UID (INSN)].reg_weight)
 235
 236 #define INSN_BLOCKAGE(INSN)     (h_i_d[INSN_UID (INSN)].blockage)
 237 #define UNIT_BITS               5
 238 #define BLOCKAGE_MASK           ((1 << BLOCKAGE_BITS) - 1)
 239 #define ENCODE_BLOCKAGE(U, R)                   \
 240   (((U) << BLOCKAGE_BITS                        \
 241     | MIN_BLOCKAGE_COST (R)) << BLOCKAGE_BITS   \
 242    | MAX_BLOCKAGE_COST (R))
 243 #define UNIT_BLOCKED(B)         ((B) >> (2 * BLOCKAGE_BITS))
 244 #define BLOCKAGE_RANGE(B)                                                \
 245   (((((B) >> BLOCKAGE_BITS) & BLOCKAGE_MASK) << (HOST_BITS_PER_INT / 2)) \
 246    | ((B) & BLOCKAGE_MASK))
 247
 248 /* Encodings of the `<name>_unit_blockage_range' function.  */
 249 #define MIN_BLOCKAGE_COST(R) ((R) >> (HOST_BITS_PER_INT / 2))
 250 #define MAX_BLOCKAGE_COST(R) ((R) & ((1 << (HOST_BITS_PER_INT / 2)) - 1))
 251
 252 extern FILE *sched_dump;
 253 extern int sched_verbose;
 254
 255 #ifndef __GNUC__
 256 #define __inline
 257 #endif
 258
 259 #ifndef HAIFA_INLINE
 260 #define HAIFA_INLINE __inline
 261 #endif
 262
 263 /* Functions in sched-vis.c.  */
 264 extern void init_target_units PARAMS ((void));
 265 extern void insn_print_units PARAMS ((rtx));
 266 extern void init_block_visualization PARAMS ((void));
 267 extern void print_block_visualization PARAMS ((const char *));
 268 extern void visualize_scheduled_insns PARAMS ((int));
 269 extern void visualize_no_unit PARAMS ((rtx));
 270 extern void visualize_stall_cycles PARAMS ((int));
 271 extern void visualize_alloc PARAMS ((void));
 272 extern void visualize_free PARAMS ((void));
 273
 274 /* Functions in sched-deps.c.  */
 275 extern void add_dependence PARAMS ((rtx, rtx, enum reg_note));
 276 extern void add_insn_mem_dependence PARAMS ((struct deps *, rtx *, rtx *, rtx,
 277                                              rtx));
 278 extern void sched_analyze PARAMS ((struct deps *, rtx, rtx));
 279 extern void init_deps PARAMS ((struct deps *));
 280 extern void free_deps PARAMS ((struct deps *));
 281 extern void init_deps_global PARAMS ((void));
 282 extern void finish_deps_global PARAMS ((void));
 283 extern void compute_forward_dependences PARAMS ((rtx, rtx));
 284 extern rtx find_insn_list PARAMS ((rtx, rtx));
 285 extern void init_dependency_caches PARAMS ((int));
 286 extern void free_dependency_caches PARAMS ((void));
 287
 288 /* Functions in haifa-sched.c.  */
 289 extern void get_block_head_tail PARAMS ((int, rtx *, rtx *));
 290 extern int no_real_insns_p PARAMS ((rtx, rtx));
 291
 292 extern void rm_line_notes PARAMS ((rtx, rtx));
 293 extern void save_line_notes PARAMS ((int, rtx, rtx));
 294 extern void restore_line_notes PARAMS ((rtx, rtx));
 295 extern void rm_redundant_line_notes PARAMS ((void));
 296 extern void rm_other_notes PARAMS ((rtx, rtx));
 297
 298 extern int insn_issue_delay PARAMS ((rtx));
 299 extern int set_priorities PARAMS ((rtx, rtx));
 300
 301 extern rtx sched_emit_insn PARAMS ((rtx));
 302 extern void schedule_block PARAMS ((int, int));
 303 extern void sched_init PARAMS ((FILE *));
 304 extern void sched_finish PARAMS ((void));
 305
 306 extern void ready_add PARAMS ((struct ready_list *, rtx));
 307
 308 /* The following are exported for the benefit of debugging functions.  It
 309    would be nicer to keep them private to haifa-sched.c.  */
 310 extern int insn_unit PARAMS ((rtx));
 311 extern int insn_cost PARAMS ((rtx, rtx, rtx));
 312 extern rtx get_unit_last_insn PARAMS ((int));
 313 extern int actual_hazard_this_instance PARAMS ((int, int, rtx, int, int));
 314 extern void print_insn PARAMS ((char *, rtx, int));