sched-int.h revision 102780
1212525Simp/* Instruction scheduling pass. This file contains definitions used 2212525Simp internally in the scheduler. 3212525Simp Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 4212525Simp 1999, 2000, 2001 Free Software Foundation, Inc. 5212525Simp 6212525SimpThis file is part of GCC. 7 8GCC is free software; you can redistribute it and/or modify it under 9the terms of the GNU General Public License as published by the Free 10Software Foundation; either version 2, or (at your option) any later 11version. 12 13GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14WARRANTY; without even the implied warranty of MERCHANTABILITY or 15FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16for more details. 17 18You should have received a copy of the GNU General Public License 19along with GCC; see the file COPYING. If not, write to the Free 20Software Foundation, 59 Temple Place - Suite 330, Boston, MA 2102111-1307, USA. */ 22 23/* Forward declaration. */ 24struct ready_list; 25 26/* Describe state of dependencies used during sched_analyze phase. */ 27struct 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 /* A list of the last function calls we have seen. We use a list to 72 represent last function calls from multiple predecessor blocks. 73 Used to prevent register lifetimes from expanding unnecessarily. */ 74 rtx last_function_call; 75 76 /* A list of insns which use a pseudo register that does not already 77 cross a call. We create dependencies between each of those insn 78 and the next call insn, to ensure that they won't cross a call after 79 scheduling is done. */ 80 rtx sched_before_next_call; 81 82 /* Used to keep post-call psuedo/hard reg movements together with 83 the call. */ 84 bool in_post_call_group_p; 85 86 /* Set to the tail insn of the outermost libcall block. 87 88 When nonzero, we will mark each insn processed by sched_analyze_insn 89 with SCHED_GROUP_P to ensure libcalls are scheduled as a unit. */ 90 rtx libcall_block_tail_insn; 91 92 /* The maximum register number for the following arrays. Before reload 93 this is max_reg_num; after reload it is FIRST_PSEUDO_REGISTER. */ 94 int max_reg; 95 96 /* Element N is the next insn that sets (hard or pseudo) register 97 N within the current basic block; or zero, if there is no 98 such insn. Needed for new registers which may be introduced 99 by splitting insns. */ 100 struct deps_reg 101 { 102 rtx uses; 103 rtx sets; 104 rtx clobbers; 105 int uses_length; 106 int clobbers_length; 107 } *reg_last; 108 109 /* Element N is set for each register that has any non-zero element 110 in reg_last[N].{uses,sets,clobbers}. */ 111 regset_head reg_last_in_use; 112}; 113 114/* This structure holds some state of the current scheduling pass, and 115 contains some function pointers that abstract out some of the non-generic 116 functionality from functions such as schedule_block or schedule_insn. 117 There is one global variable, current_sched_info, which points to the 118 sched_info structure currently in use. */ 119struct sched_info 120{ 121 /* Add all insns that are initially ready to the ready list. Called once 122 before scheduling a set of insns. */ 123 void (*init_ready_list) PARAMS ((struct ready_list *)); 124 /* Called after taking an insn from the ready list. Returns nonzero if 125 this insn can be scheduled, nonzero if we should silently discard it. */ 126 int (*can_schedule_ready_p) PARAMS ((rtx)); 127 /* Return nonzero if there are more insns that should be scheduled. */ 128 int (*schedule_more_p) PARAMS ((void)); 129 /* Called after an insn has all its dependencies resolved. Return nonzero 130 if it should be moved to the ready list or the queue, or zero if we 131 should silently discard it. */ 132 int (*new_ready) PARAMS ((rtx)); 133 /* Compare priority of two insns. Return a positive number if the second 134 insn is to be preferred for scheduling, and a negative one if the first 135 is to be preferred. Zero if they are equally good. */ 136 int (*rank) PARAMS ((rtx, rtx)); 137 /* Return a string that contains the insn uid and optionally anything else 138 necessary to identify this insn in an output. It's valid to use a 139 static buffer for this. The ALIGNED parameter should cause the string 140 to be formatted so that multiple output lines will line up nicely. */ 141 const char *(*print_insn) PARAMS ((rtx, int)); 142 /* Return nonzero if an insn should be included in priority 143 calculations. */ 144 int (*contributes_to_priority) PARAMS ((rtx, rtx)); 145 /* Called when computing dependencies for a JUMP_INSN. This function 146 should store the set of registers that must be considered as set by 147 the jump in the regset. */ 148 void (*compute_jump_reg_dependencies) PARAMS ((rtx, regset)); 149 150 /* The boundaries of the set of insns to be scheduled. */ 151 rtx prev_head, next_tail; 152 153 /* Filled in after the schedule is finished; the first and last scheduled 154 insns. */ 155 rtx head, tail; 156 157 /* If nonzero, enables an additional sanity check in schedule_block. */ 158 unsigned int queue_must_finish_empty:1; 159 /* Nonzero if we should use cselib for better alias analysis. This 160 must be 0 if the dependency information is used after sched_analyze 161 has completed, e.g. if we're using it to initialize state for successor 162 blocks in region scheduling. */ 163 unsigned int use_cselib:1; 164}; 165 166extern struct sched_info *current_sched_info; 167 168/* Indexed by INSN_UID, the collection of all data associated with 169 a single instruction. */ 170 171struct haifa_insn_data 172{ 173 /* A list of insns which depend on the instruction. Unlike LOG_LINKS, 174 it represents forward dependencies. */ 175 rtx depend; 176 177 /* The line number note in effect for each insn. For line number 178 notes, this indicates whether the note may be reused. */ 179 rtx line_note; 180 181 /* Logical uid gives the original ordering of the insns. */ 182 int luid; 183 184 /* A priority for each insn. */ 185 int priority; 186 187 /* The number of incoming edges in the forward dependency graph. 188 As scheduling proceds, counts are decreased. An insn moves to 189 the ready queue when its counter reaches zero. */ 190 int dep_count; 191 192 /* An encoding of the blockage range function. Both unit and range 193 are coded. */ 194 unsigned int blockage; 195 196 /* Number of instructions referring to this insn. */ 197 int ref_count; 198 199 /* The minimum clock tick at which the insn becomes ready. This is 200 used to note timing constraints for the insns in the pending list. */ 201 int tick; 202 203 short cost; 204 205 /* An encoding of the function units used. */ 206 short units; 207 208 /* This weight is an estimation of the insn's contribution to 209 register pressure. */ 210 short reg_weight; 211 212 /* Some insns (e.g. call) are not allowed to move across blocks. */ 213 unsigned int cant_move : 1; 214 215 /* Set if there's DEF-USE dependence between some speculatively 216 moved load insn and this one. */ 217 unsigned int fed_by_spec_load : 1; 218 unsigned int is_load_insn : 1; 219 220 /* Nonzero if priority has been computed already. */ 221 unsigned int priority_known : 1; 222}; 223 224extern struct haifa_insn_data *h_i_d; 225 226/* Accessor macros for h_i_d. There are more in haifa-sched.c and 227 sched-rgn.c. */ 228#define INSN_DEPEND(INSN) (h_i_d[INSN_UID (INSN)].depend) 229#define INSN_LUID(INSN) (h_i_d[INSN_UID (INSN)].luid) 230#define CANT_MOVE(insn) (h_i_d[INSN_UID (insn)].cant_move) 231#define INSN_DEP_COUNT(INSN) (h_i_d[INSN_UID (INSN)].dep_count) 232#define INSN_PRIORITY(INSN) (h_i_d[INSN_UID (INSN)].priority) 233#define INSN_PRIORITY_KNOWN(INSN) (h_i_d[INSN_UID (INSN)].priority_known) 234#define INSN_COST(INSN) (h_i_d[INSN_UID (INSN)].cost) 235#define INSN_UNIT(INSN) (h_i_d[INSN_UID (INSN)].units) 236#define INSN_REG_WEIGHT(INSN) (h_i_d[INSN_UID (INSN)].reg_weight) 237 238#define INSN_BLOCKAGE(INSN) (h_i_d[INSN_UID (INSN)].blockage) 239#define UNIT_BITS 5 240#define BLOCKAGE_MASK ((1 << BLOCKAGE_BITS) - 1) 241#define ENCODE_BLOCKAGE(U, R) \ 242 (((U) << BLOCKAGE_BITS \ 243 | MIN_BLOCKAGE_COST (R)) << BLOCKAGE_BITS \ 244 | MAX_BLOCKAGE_COST (R)) 245#define UNIT_BLOCKED(B) ((B) >> (2 * BLOCKAGE_BITS)) 246#define BLOCKAGE_RANGE(B) \ 247 (((((B) >> BLOCKAGE_BITS) & BLOCKAGE_MASK) << (HOST_BITS_PER_INT / 2)) \ 248 | ((B) & BLOCKAGE_MASK)) 249 250/* Encodings of the `<name>_unit_blockage_range' function. */ 251#define MIN_BLOCKAGE_COST(R) ((R) >> (HOST_BITS_PER_INT / 2)) 252#define MAX_BLOCKAGE_COST(R) ((R) & ((1 << (HOST_BITS_PER_INT / 2)) - 1)) 253 254extern FILE *sched_dump; 255extern int sched_verbose; 256 257#ifndef __GNUC__ 258#define __inline 259#endif 260 261#ifndef HAIFA_INLINE 262#define HAIFA_INLINE __inline 263#endif 264 265/* Functions in sched-vis.c. */ 266extern void init_target_units PARAMS ((void)); 267extern void insn_print_units PARAMS ((rtx)); 268extern void init_block_visualization PARAMS ((void)); 269extern void print_block_visualization PARAMS ((const char *)); 270extern void visualize_scheduled_insns PARAMS ((int)); 271extern void visualize_no_unit PARAMS ((rtx)); 272extern void visualize_stall_cycles PARAMS ((int)); 273extern void visualize_alloc PARAMS ((void)); 274extern void visualize_free PARAMS ((void)); 275 276/* Functions in sched-deps.c. */ 277extern void add_dependence PARAMS ((rtx, rtx, enum reg_note)); 278extern void add_insn_mem_dependence PARAMS ((struct deps *, rtx *, rtx *, rtx, 279 rtx)); 280extern void sched_analyze PARAMS ((struct deps *, rtx, rtx)); 281extern void init_deps PARAMS ((struct deps *)); 282extern void free_deps PARAMS ((struct deps *)); 283extern void init_deps_global PARAMS ((void)); 284extern void finish_deps_global PARAMS ((void)); 285extern void compute_forward_dependences PARAMS ((rtx, rtx)); 286extern rtx find_insn_list PARAMS ((rtx, rtx)); 287extern void init_dependency_caches PARAMS ((int)); 288extern void free_dependency_caches PARAMS ((void)); 289 290/* Functions in haifa-sched.c. */ 291extern void get_block_head_tail PARAMS ((int, rtx *, rtx *)); 292extern int no_real_insns_p PARAMS ((rtx, rtx)); 293 294extern void rm_line_notes PARAMS ((rtx, rtx)); 295extern void save_line_notes PARAMS ((int, rtx, rtx)); 296extern void restore_line_notes PARAMS ((rtx, rtx)); 297extern void rm_redundant_line_notes PARAMS ((void)); 298extern void rm_other_notes PARAMS ((rtx, rtx)); 299 300extern int insn_issue_delay PARAMS ((rtx)); 301extern int set_priorities PARAMS ((rtx, rtx)); 302 303extern rtx sched_emit_insn PARAMS ((rtx)); 304extern void schedule_block PARAMS ((int, int)); 305extern void sched_init PARAMS ((FILE *)); 306extern void sched_finish PARAMS ((void)); 307 308extern void ready_add PARAMS ((struct ready_list *, rtx)); 309 310/* The following are exported for the benefit of debugging functions. It 311 would be nicer to keep them private to haifa-sched.c. */ 312extern int insn_unit PARAMS ((rtx)); 313extern int insn_cost PARAMS ((rtx, rtx, rtx)); 314extern rtx get_unit_last_insn PARAMS ((int)); 315extern int actual_hazard_this_instance PARAMS ((int, int, rtx, int, int)); 316 317