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