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 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   /* Element N is the next insn that sets (hard or pseudo) register
  82      N within the current basic block; or zero, if there is no
  83      such insn.  Needed for new registers which may be introduced
  84      by splitting insns.  */
  85   rtx *reg_last_uses;
  86   rtx *reg_last_sets;
  87   rtx *reg_last_clobbers;
  88 };
  89
  90 /* This structure holds some state of the current scheduling pass, and
  91    contains some function pointers that abstract out some of the non-generic
  92    functionality from functions such as schedule_block or schedule_insn.
  93    There is one global variable, current_sched_info, which points to the
  94    sched_info structure currently in use.  */
  95 struct sched_info
  96 {
  97   /* Add all insns that are initially ready to the ready list.  Called once
  98      before scheduling a set of insns.  */
  99   void (*init_ready_list) PARAMS ((struct ready_list *));
 100   /* Called after taking an insn from the ready list.  Returns nonzero if
 101      this insn can be scheduled, nonzero if we should silently discard it.  */
 102   int (*can_schedule_ready_p) PARAMS ((rtx));
 103   /* Return nonzero if there are more insns that should be scheduled.  */
 104   int (*schedule_more_p) PARAMS ((void));
 105   /* Called after an insn has all its dependencies resolved.  Return nonzero
 106      if it should be moved to the ready list or the queue, or zero if we
 107      should silently discard it.  */
 108   int (*new_ready) PARAMS ((rtx));
 109   /* Compare priority of two insns.  Return a positive number if the second
 110      insn is to be preferred for scheduling, and a negative one if the first
 111      is to be preferred.  Zero if they are equally good.  */
 112   int (*rank) PARAMS ((rtx, rtx));
 113   /* Return a string that contains the insn uid and optionally anything else
 114      necessary to identify this insn in an output.  It's valid to use a
 115      static buffer for this.  The ALIGNED parameter should cause the string
 116      to be formatted so that multiple output lines will line up nicely.  */
 117   const char *(*print_insn) PARAMS ((rtx, int));
 118
 119   /* The boundaries of the set of insns to be scheduled.  */
 120   rtx prev_head, next_tail;
 121
 122   /* Filled in after the schedule is finished; the first and last scheduled
 123      insns.  */
 124   rtx head, tail;
 125
 126   /* If nonzero, enables an additional sanity check in schedule_block.  */
 127   int queue_must_finish_empty;
 128 };
 129
 130 extern struct sched_info *current_sched_info;
 131
 132 /* Indexed by INSN_UID, the collection of all data associated with
 133    a single instruction.  */
 134
 135 struct haifa_insn_data
 136 {
 137   /* A list of insns which depend on the instruction.  Unlike LOG_LINKS,
 138      it represents forward dependancies.  */
 139   rtx depend;
 140
 141   /* The line number note in effect for each insn.  For line number
 142      notes, this indicates whether the note may be reused.  */
 143   rtx line_note;
 144
 145   /* Logical uid gives the original ordering of the insns.  */
 146   int luid;
 147
 148   /* A priority for each insn.  */
 149   int priority;
 150
 151   /* The number of incoming edges in the forward dependency graph.
 152      As scheduling proceds, counts are decreased.  An insn moves to
 153      the ready queue when its counter reaches zero.  */
 154   int dep_count;
 155
 156   /* An encoding of the blockage range function.  Both unit and range
 157      are coded.  */
 158   unsigned int blockage;
 159
 160   /* Number of instructions referring to this insn.  */
 161   int ref_count;
 162
 163   /* The minimum clock tick at which the insn becomes ready.  This is
 164      used to note timing constraints for the insns in the pending list.  */
 165   int tick;
 166
 167   short cost;
 168
 169   /* An encoding of the function units used.  */
 170   short units;
 171
 172   /* This weight is an estimation of the insn's contribution to
 173      register pressure.  */
 174   short reg_weight;
 175
 176   /* Some insns (e.g. call) are not allowed to move across blocks.  */
 177   unsigned int cant_move : 1;
 178
 179   /* Set if there's DEF-USE dependance between some speculatively
 180      moved load insn and this one.  */
 181   unsigned int fed_by_spec_load : 1;
 182   unsigned int is_load_insn : 1;
 183 };
 184
 185 extern struct haifa_insn_data *h_i_d;
 186
 187 /* Accessor macros for h_i_d.  There are more in haifa-sched.c.  */
 188 #define INSN_DEPEND(INSN)       (h_i_d[INSN_UID (INSN)].depend)
 189 #define INSN_LUID(INSN)         (h_i_d[INSN_UID (INSN)].luid)
 190 #define CANT_MOVE(insn)         (h_i_d[INSN_UID (insn)].cant_move)
 191 #define INSN_DEP_COUNT(INSN)    (h_i_d[INSN_UID (INSN)].dep_count)
 192
 193 extern FILE *sched_dump;
 194
 195 #ifndef __GNUC__
 196 #define __inline
 197 #endif
 198
 199 #ifndef HAIFA_INLINE
 200 #define HAIFA_INLINE __inline
 201 #endif
 202
 203 /* Functions in sched-vis.c.  */
 204 extern void init_target_units PARAMS ((void));
 205 extern void insn_print_units PARAMS ((rtx));
 206 extern void init_block_visualization PARAMS ((void));
 207 extern void print_block_visualization PARAMS ((const char *));
 208 extern void visualize_scheduled_insns PARAMS ((int));
 209 extern void visualize_no_unit PARAMS ((rtx));
 210 extern void visualize_stall_cycles PARAMS ((int));
 211 extern void visualize_alloc PARAMS ((void));
 212 extern void visualize_free PARAMS ((void));
 213
 214 /* Functions in sched-deps.c.  */
 215 extern void add_dependence PARAMS ((rtx, rtx, enum reg_note));
 216 extern void add_insn_mem_dependence PARAMS ((struct deps *, rtx *, rtx *, rtx,
 217                                              rtx));
 218 extern void sched_analyze PARAMS ((struct deps *, rtx, rtx));
 219 extern void init_deps PARAMS ((struct deps *));
 220 extern void free_deps PARAMS ((struct deps *));
 221 extern void init_deps_global PARAMS ((void));
 222 extern void finish_deps_global PARAMS ((void));
 223 extern void compute_forward_dependences PARAMS ((rtx, rtx));
 224 extern int find_insn_mem_list PARAMS ((rtx, rtx, rtx, rtx));
 225 extern rtx find_insn_list PARAMS ((rtx, rtx));
 226 extern void init_dependency_caches PARAMS ((int));
 227 extern void free_dependency_caches PARAMS ((void));
 228
 229 /* Functions in haifa-sched.c.  */
 230 extern int insn_unit PARAMS ((rtx));
 231 extern rtx get_unit_last_insn PARAMS ((int));
 232 extern int actual_hazard_this_instance PARAMS ((int, int, rtx, int, int));
 233