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 GNU CC.
   7
   8 GNU CC is free software; you can redistribute it and/or modify it
   9 under the terms of the GNU General Public License as published by the
  10 Free Software Foundation; either version 2, or (at your option) any
  11 later version.
  12
  13 GNU CC is distributed in the hope that it will be useful, but WITHOUT
  14 ANY 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 GNU CC; see the file COPYING.  If not, write to the Free
  20 the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  21 02111-1307, USA.  */
  22
  23 /* Forward declaration.  */
  24 struct ready_list;
  25
  26 /* Describe state of dependencies used during sched_analyze phase.  */
  27 struct deps
  28 {
  29   /* The *_insns and *_mems are paired lists.  Each pending memory operation
  30      will have a pointer to the MEM rtx on one list and a pointer to the
  31      containing insn on the other list in the same place in the list.  */
  32
  33   /* We can't use add_dependence like the old code did, because a single insn
  34      may have multiple memory accesses, and hence needs to be on the list
  35      once for each memory access.  Add_dependence won't let you add an insn
  36      to a list more than once.  */
  37
  38   /* An INSN_LIST containing all insns with pending read operations.  */
  39   rtx pending_read_insns;
  40
  41   /* An EXPR_LIST containing all MEM rtx's which are pending reads.  */
  42   rtx pending_read_mems;
  43
  44   /* An INSN_LIST containing all insns with pending write operations.  */
  45   rtx pending_write_insns;
  46
  47   /* An EXPR_LIST containing all MEM rtx's which are pending writes.  */
  48   rtx pending_write_mems;
  49
  50   /* Indicates the combined length of the two pending lists.  We must prevent
  51      these lists from ever growing too large since the number of dependencies
  52      produced is at least O(N*N), and execution time is at least O(4*N*N), as
  53      a function of the length of these pending lists.  */
  54   int pending_lists_length;
  55
  56   /* The last insn upon which all memory references must depend.
  57      This is an insn which flushed the pending lists, creating a dependency
  58      between it and all previously pending memory references.  This creates
  59      a barrier (or a checkpoint) which no memory reference is allowed to cross.
  60
  61      This includes all non constant CALL_INSNs.  When we do interprocedural
  62      alias analysis, this restriction can be relaxed.
  63      This may also be an INSN that writes memory if the pending lists grow
  64      too large.  */
  65   rtx last_pending_memory_flush;
  66
  67   /* The last function call we have seen.  All hard regs, and, of course,
  68      the last function call, must depend on this.  */
  69   rtx last_function_call;
  70
  71   /* Used to keep post-call psuedo/hard reg movements together with
  72      the call.  */
  73   int in_post_call_group_p;
  74
  75   /* The LOG_LINKS field of this is a list of insns which use a pseudo
  76      register that does not already cross a call.  We create
  77      dependencies between each of those insn and the next call insn,
  78      to ensure that they won't cross a call after scheduling is done.  */
  79   rtx sched_before_next_call;
  80
  81   /* The maximum register number for the following arrays.  Before reload
  82      this is max_reg_num; after reload it is FIRST_PSEUDO_REGISTER.  */
  83   int max_reg;
  84
  85   /* Element N is the next insn that sets (hard or pseudo) register
  86      N within the current basic block; or zero, if there is no
  87      such insn.  Needed for new registers which may be introduced
  88      by splitting insns.  */
  89   struct deps_reg
  90     {
  91       rtx uses;
  92       rtx sets;
  93       rtx clobbers;
  94     } *reg_last;
  95
  96   /* Element N is set for each register that has any non-zero element
  97      in reg_last[N].{uses,sets,clobbers}.  */
  98   regset_head reg_last_in_use;
  99 };
 100
 101 /* This structure holds some state of the current scheduling pass, and
 102    contains some function pointers that abstract out some of the non-generic
 103    functionality from functions such as schedule_block or schedule_insn.
 104    There is one global variable, current_sched_info, which points to the
 105    sched_info structure currently in use.  */
 106 struct sched_info
 107 {
 108   /* Add all insns that are initially ready to the ready list.  Called once
 109      before scheduling a set of insns.  */
 110   void (*init_ready_list) PARAMS ((struct ready_list *));
 111   /* Called after taking an insn from the ready list.  Returns nonzero if
 112      this insn can be scheduled, nonzero if we should silently discard it.  */
 113   int (*can_schedule_ready_p) PARAMS ((rtx));
 114   /* Return nonzero if there are more insns that should be scheduled.  */
 115   int (*schedule_more_p) PARAMS ((void));
 116   /* Called after an insn has all its dependencies resolved.  Return nonzero
 117      if it should be moved to the ready list or the queue, or zero if we
 118      should silently discard it.  */
 119   int (*new_ready) PARAMS ((rtx));
 120   /* Compare priority of two insns.  Return a positive number if the second
 121      insn is to be preferred for scheduling, and a negative one if the first
 122      is to be preferred.  Zero if they are equally good.  */
 123   int (*rank) PARAMS ((rtx, rtx));
 124   /* Return a string that contains the insn uid and optionally anything else
 125      necessary to identify this insn in an output.  It's valid to use a
 126      static buffer for this.  The ALIGNED parameter should cause the string
 127      to be formatted so that multiple output lines will line up nicely.  */
 128   const char *(*print_insn) PARAMS ((rtx, int));
 129   /* Return nonzero if an insn should be included in priority
 130      calculations.  */
 131   int (*contributes_to_priority) PARAMS ((rtx, rtx));
 132   /* Called when computing dependencies for a JUMP_INSN.  This function
 133      should store the set of registers that must be considered as set by
 134      the jump in the regset.  */
 135   void (*compute_jump_reg_dependencies) PARAMS ((rtx, regset));
 136
 137   /* The boundaries of the set of insns to be scheduled.  */
 138   rtx prev_head, next_tail;
 139
 140   /* Filled in after the schedule is finished; the first and last scheduled
 141      insns.  */
 142   rtx head, tail;
 143
 144   /* If nonzero, enables an additional sanity check in schedule_block.  */
 145   int queue_must_finish_empty;
 146 };
 147
 148 extern struct sched_info *current_sched_info;
 149
 150 /* Indexed by INSN_UID, the collection of all data associated with
 151    a single instruction.  */
 152
 153 struct haifa_insn_data
 154 {
 155   /* A list of insns which depend on the instruction.  Unlike LOG_LINKS,
 156      it represents forward dependancies.  */
 157   rtx depend;
 158
 159   /* The line number note in effect for each insn.  For line number
 160      notes, this indicates whether the note may be reused.  */
 161   rtx line_note;
 162
 163   /* Logical uid gives the original ordering of the insns.  */
 164   int luid;
 165
 166   /* A priority for each insn.  */
 167   int priority;
 168
 169   /* The number of incoming edges in the forward dependency graph.
 170      As scheduling proceds, counts are decreased.  An insn moves to
 171      the ready queue when its counter reaches zero.  */
 172   int dep_count;
 173
 174   /* An encoding of the blockage range function.  Both unit and range
 175      are coded.  */
 176   unsigned int blockage;
 177
 178   /* Number of instructions referring to this insn.  */
 179   int ref_count;
 180
 181   /* The minimum clock tick at which the insn becomes ready.  This is
 182      used to note timing constraints for the insns in the pending list.  */
 183   int tick;
 184
 185   short cost;
 186
 187   /* An encoding of the function units used.  */
 188   short units;
 189
 190   /* This weight is an estimation of the insn's contribution to
 191      register pressure.  */
 192   short reg_weight;
 193
 194   /* Some insns (e.g. call) are not allowed to move across blocks.  */
 195   unsigned int cant_move : 1;
 196
 197   /* Set if there's DEF-USE dependance between some speculatively
 198      moved load insn and this one.  */
 199   unsigned int fed_by_spec_load : 1;
 200   unsigned int is_load_insn : 1;
 201
 202   /* Nonzero if priority has been computed already.  */
 203   unsigned int priority_known : 1;
 204 };
 205
 206 extern struct haifa_insn_data *h_i_d;
 207
 208 /* Accessor macros for h_i_d.  There are more in haifa-sched.c and
 209    sched-rgn.c.  */
 210 #define INSN_DEPEND(INSN)       (h_i_d[INSN_UID (INSN)].depend)
 211 #define INSN_LUID(INSN)         (h_i_d[INSN_UID (INSN)].luid)
 212 #define CANT_MOVE(insn)         (h_i_d[INSN_UID (insn)].cant_move)
 213 #define INSN_DEP_COUNT(INSN)    (h_i_d[INSN_UID (INSN)].dep_count)
 214 #define INSN_PRIORITY(INSN)     (h_i_d[INSN_UID (INSN)].priority)
 215 #define INSN_PRIORITY_KNOWN(INSN) (h_i_d[INSN_UID (INSN)].priority_known)
 216 #define INSN_COST(INSN)         (h_i_d[INSN_UID (INSN)].cost)
 217 #define INSN_UNIT(INSN)         (h_i_d[INSN_UID (INSN)].units)
 218 #define INSN_REG_WEIGHT(INSN)   (h_i_d[INSN_UID (INSN)].reg_weight)
 219
 220 #define INSN_BLOCKAGE(INSN)     (h_i_d[INSN_UID (INSN)].blockage)
 221 #define UNIT_BITS               5
 222 #define BLOCKAGE_MASK           ((1 << BLOCKAGE_BITS) - 1)
 223 #define ENCODE_BLOCKAGE(U, R)                   \
 224   (((U) << BLOCKAGE_BITS                        \
 225     | MIN_BLOCKAGE_COST (R)) << BLOCKAGE_BITS   \
 226    | MAX_BLOCKAGE_COST (R))
 227 #define UNIT_BLOCKED(B)         ((B) >> (2 * BLOCKAGE_BITS))
 228 #define BLOCKAGE_RANGE(B)                                                \
 229   (((((B) >> BLOCKAGE_BITS) & BLOCKAGE_MASK) << (HOST_BITS_PER_INT / 2)) \
 230    | ((B) & BLOCKAGE_MASK))
 231
 232 /* Encodings of the `<name>_unit_blockage_range' function.  */
 233 #define MIN_BLOCKAGE_COST(R) ((R) >> (HOST_BITS_PER_INT / 2))
 234 #define MAX_BLOCKAGE_COST(R) ((R) & ((1 << (HOST_BITS_PER_INT / 2)) - 1))
 235
 236 extern FILE *sched_dump;
 237 extern int sched_verbose;
 238
 239 #ifndef __GNUC__
 240 #define __inline
 241 #endif
 242
 243 #ifndef HAIFA_INLINE
 244 #define HAIFA_INLINE __inline
 245 #endif
 246
 247 /* Functions in sched-vis.c.  */
 248 extern void init_target_units PARAMS ((void));
 249 extern void insn_print_units PARAMS ((rtx));
 250 extern void init_block_visualization PARAMS ((void));
 251 extern void print_block_visualization PARAMS ((const char *));
 252 extern void visualize_scheduled_insns PARAMS ((int));
 253 extern void visualize_no_unit PARAMS ((rtx));
 254 extern void visualize_stall_cycles PARAMS ((int));
 255 extern void visualize_alloc PARAMS ((void));
 256 extern void visualize_free PARAMS ((void));
 257
 258 /* Functions in sched-deps.c.  */
 259 extern void add_dependence PARAMS ((rtx, rtx, enum reg_note));
 260 extern void add_insn_mem_dependence PARAMS ((struct deps *, rtx *, rtx *, rtx,
 261                                              rtx));
 262 extern void sched_analyze PARAMS ((struct deps *, rtx, rtx));
 263 extern void init_deps PARAMS ((struct deps *));
 264 extern void free_deps PARAMS ((struct deps *));
 265 extern void init_deps_global PARAMS ((void));
 266 extern void finish_deps_global PARAMS ((void));
 267 extern void compute_forward_dependences PARAMS ((rtx, rtx));
 268 extern int find_insn_mem_list PARAMS ((rtx, rtx, rtx, rtx));
 269 extern rtx find_insn_list PARAMS ((rtx, rtx));
 270 extern void init_dependency_caches PARAMS ((int));
 271 extern void free_dependency_caches PARAMS ((void));
 272
 273 /* Functions in haifa-sched.c.  */
 274 extern void get_block_head_tail PARAMS ((int, rtx *, rtx *));
 275 extern int no_real_insns_p PARAMS ((rtx, rtx));
 276
 277 extern void rm_line_notes PARAMS ((rtx, rtx));
 278 extern void save_line_notes PARAMS ((int, rtx, rtx));
 279 extern void restore_line_notes PARAMS ((rtx, rtx));
 280 extern void rm_redundant_line_notes PARAMS ((void));
 281 extern void rm_other_notes PARAMS ((rtx, rtx));
 282
 283 extern int insn_issue_delay PARAMS ((rtx));
 284 extern int set_priorities PARAMS ((rtx, rtx));
 285
 286 extern void schedule_block PARAMS ((int, int));
 287 extern void sched_init PARAMS ((FILE *));
 288 extern void sched_finish PARAMS ((void));
 289
 290 extern void ready_add PARAMS ((struct ready_list *, rtx));
 291
 292 /* The following are exported for the benefit of debugging functions.  It
 293    would be nicer to keep them private to haifa-sched.c.  */
 294 extern int insn_unit PARAMS ((rtx));
 295 extern int insn_cost PARAMS ((rtx, rtx, rtx));
 296 extern rtx get_unit_last_insn PARAMS ((int));
 297 extern int actual_hazard_this_instance PARAMS ((int, int, rtx, int, int));
 298