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   /* 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   int queue_must_finish_empty;
 150 };
 151
 152 extern struct sched_info *current_sched_info;
 153
 154 /* Indexed by INSN_UID, the collection of all data associated with
 155    a single instruction.  */
 156
 157 struct haifa_insn_data
 158 {
 159   /* A list of insns which depend on the instruction.  Unlike LOG_LINKS,
 160      it represents forward dependancies.  */
 161   rtx depend;
 162
 163   /* The line number note in effect for each insn.  For line number
 164      notes, this indicates whether the note may be reused.  */
 165   rtx line_note;
 166
 167   /* Logical uid gives the original ordering of the insns.  */
 168   int luid;
 169
 170   /* A priority for each insn.  */
 171   int priority;
 172
 173   /* The number of incoming edges in the forward dependency graph.
 174      As scheduling proceds, counts are decreased.  An insn moves to
 175      the ready queue when its counter reaches zero.  */
 176   int dep_count;
 177
 178   /* An encoding of the blockage range function.  Both unit and range
 179      are coded.  */
 180   unsigned int blockage;
 181
 182   /* Number of instructions referring to this insn.  */
 183   int ref_count;
 184
 185   /* The minimum clock tick at which the insn becomes ready.  This is
 186      used to note timing constraints for the insns in the pending list.  */
 187   int tick;
 188
 189   short cost;
 190
 191   /* An encoding of the function units used.  */
 192   short units;
 193
 194   /* This weight is an estimation of the insn's contribution to
 195      register pressure.  */
 196   short reg_weight;
 197
 198   /* Some insns (e.g. call) are not allowed to move across blocks.  */
 199   unsigned int cant_move : 1;
 200
 201   /* Set if there's DEF-USE dependance between some speculatively
 202      moved load insn and this one.  */
 203   unsigned int fed_by_spec_load : 1;
 204   unsigned int is_load_insn : 1;
 205
 206   /* Nonzero if priority has been computed already.  */
 207   unsigned int priority_known : 1;
 208 };
 209
 210 extern struct haifa_insn_data *h_i_d;
 211
 212 /* Accessor macros for h_i_d.  There are more in haifa-sched.c and
 213    sched-rgn.c.  */
 214 #define INSN_DEPEND(INSN)       (h_i_d[INSN_UID (INSN)].depend)
 215 #define INSN_LUID(INSN)         (h_i_d[INSN_UID (INSN)].luid)
 216 #define CANT_MOVE(insn)         (h_i_d[INSN_UID (insn)].cant_move)
 217 #define INSN_DEP_COUNT(INSN)    (h_i_d[INSN_UID (INSN)].dep_count)
 218 #define INSN_PRIORITY(INSN)     (h_i_d[INSN_UID (INSN)].priority)
 219 #define INSN_PRIORITY_KNOWN(INSN) (h_i_d[INSN_UID (INSN)].priority_known)
 220 #define INSN_COST(INSN)         (h_i_d[INSN_UID (INSN)].cost)
 221 #define INSN_UNIT(INSN)         (h_i_d[INSN_UID (INSN)].units)
 222 #define INSN_REG_WEIGHT(INSN)   (h_i_d[INSN_UID (INSN)].reg_weight)
 223
 224 #define INSN_BLOCKAGE(INSN)     (h_i_d[INSN_UID (INSN)].blockage)
 225 #define UNIT_BITS               5
 226 #define BLOCKAGE_MASK           ((1 << BLOCKAGE_BITS) - 1)
 227 #define ENCODE_BLOCKAGE(U, R)                   \
 228   (((U) << BLOCKAGE_BITS                        \
 229     | MIN_BLOCKAGE_COST (R)) << BLOCKAGE_BITS   \
 230    | MAX_BLOCKAGE_COST (R))
 231 #define UNIT_BLOCKED(B)         ((B) >> (2 * BLOCKAGE_BITS))
 232 #define BLOCKAGE_RANGE(B)                                                \
 233   (((((B) >> BLOCKAGE_BITS) & BLOCKAGE_MASK) << (HOST_BITS_PER_INT / 2)) \
 234    | ((B) & BLOCKAGE_MASK))
 235
 236 /* Encodings of the `<name>_unit_blockage_range' function.  */
 237 #define MIN_BLOCKAGE_COST(R) ((R) >> (HOST_BITS_PER_INT / 2))
 238 #define MAX_BLOCKAGE_COST(R) ((R) & ((1 << (HOST_BITS_PER_INT / 2)) - 1))
 239
 240 extern FILE *sched_dump;
 241 extern int sched_verbose;
 242
 243 #ifndef __GNUC__
 244 #define __inline
 245 #endif
 246
 247 #ifndef HAIFA_INLINE
 248 #define HAIFA_INLINE __inline
 249 #endif
 250
 251 /* Functions in sched-vis.c.  */
 252 extern void init_target_units PARAMS ((void));
 253 extern void insn_print_units PARAMS ((rtx));
 254 extern void init_block_visualization PARAMS ((void));
 255 extern void print_block_visualization PARAMS ((const char *));
 256 extern void visualize_scheduled_insns PARAMS ((int));
 257 extern void visualize_no_unit PARAMS ((rtx));
 258 extern void visualize_stall_cycles PARAMS ((int));
 259 extern void visualize_alloc PARAMS ((void));
 260 extern void visualize_free PARAMS ((void));
 261
 262 /* Functions in sched-deps.c.  */
 263 extern void add_dependence PARAMS ((rtx, rtx, enum reg_note));
 264 extern void add_insn_mem_dependence PARAMS ((struct deps *, rtx *, rtx *, rtx,
 265                                              rtx));
 266 extern void sched_analyze PARAMS ((struct deps *, rtx, rtx));
 267 extern void init_deps PARAMS ((struct deps *));
 268 extern void free_deps PARAMS ((struct deps *));
 269 extern void init_deps_global PARAMS ((void));
 270 extern void finish_deps_global PARAMS ((void));
 271 extern void compute_forward_dependences PARAMS ((rtx, rtx));
 272 extern int find_insn_mem_list PARAMS ((rtx, rtx, rtx, rtx));
 273 extern rtx find_insn_list PARAMS ((rtx, rtx));
 274 extern void init_dependency_caches PARAMS ((int));
 275 extern void free_dependency_caches PARAMS ((void));
 276
 277 /* Functions in haifa-sched.c.  */
 278 extern void get_block_head_tail PARAMS ((int, rtx *, rtx *));
 279 extern int no_real_insns_p PARAMS ((rtx, rtx));
 280
 281 extern void rm_line_notes PARAMS ((rtx, rtx));
 282 extern void save_line_notes PARAMS ((int, rtx, rtx));
 283 extern void restore_line_notes PARAMS ((rtx, rtx));
 284 extern void rm_redundant_line_notes PARAMS ((void));
 285 extern void rm_other_notes PARAMS ((rtx, rtx));
 286
 287 extern int insn_issue_delay PARAMS ((rtx));
 288 extern int set_priorities PARAMS ((rtx, rtx));
 289
 290 extern void schedule_block PARAMS ((int, int));
 291 extern void sched_init PARAMS ((FILE *));
 292 extern void sched_finish PARAMS ((void));
 293
 294 extern void ready_add PARAMS ((struct ready_list *, rtx));
 295
 296 /* The following are exported for the benefit of debugging functions.  It
 297    would be nicer to keep them private to haifa-sched.c.  */
 298 extern int insn_unit PARAMS ((rtx));
 299 extern int insn_cost PARAMS ((rtx, rtx, rtx));
 300 extern rtx get_unit_last_insn PARAMS ((int));
 301 extern int actual_hazard_this_instance PARAMS ((int, int, rtx, int, int));
 302