sim/common/cgen-scache.h

   1 /* Simulator header for cgen scache support.
   2    Copyright (C) 1998-2023 Free Software Foundation, Inc.
   3    Contributed by Cygnus Solutions.
   4
   5 This file is part of GDB, the GNU debugger.
   6
   7 This program is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3 of the License, or
  10 (at your option) any later version.
  11
  12 This program is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef CGEN_SCACHE_H
  21 #define CGEN_SCACHE_H
  22
  23 /* When caching bb's, instructions are extracted into "chains".
  24    SCACHE_MAP is a hash table into these chains.  */
  25
  26 typedef struct {
  27   IADDR pc;
  28   SCACHE *sc;
  29 } SCACHE_MAP;
  30
  31 typedef struct cpu_scache {
  32   /* Simulator cache size.  Must be a power of 2.
  33      This is the number of elements in the `cache' member.  */
  34   unsigned int size;
  35 #define CPU_SCACHE_SIZE(cpu) ((cpu) -> cgen_cpu.scache.size)
  36   /* The cache.  */
  37   SCACHE *cache;
  38 #define CPU_SCACHE_CACHE(cpu) ((cpu) -> cgen_cpu.scache.cache)
  39
  40 #if WITH_SCACHE_PBB
  41   /* Number of hash chains.  Must be a power of 2.  */
  42   unsigned int num_hash_chains;
  43 #define CPU_SCACHE_NUM_HASH_CHAINS(cpu) ((cpu) -> cgen_cpu.scache.num_hash_chains)
  44   /* Number of entries in each hash chain.
  45      The hash table is a statically allocated NxM array where
  46      N = num_hash_chains
  47      M = num_hash_chain_entries.  */
  48   unsigned int num_hash_chain_entries;
  49 #define CPU_SCACHE_NUM_HASH_CHAIN_ENTRIES(cpu) ((cpu) -> cgen_cpu.scache.num_hash_chain_entries)
  50   /* Maximum number of instructions in a chain.
  51      ??? This just let's us set a static size of chain_lengths table.
  52      In a simulation that handles more than just the cpu, this might also be
  53      used to keep too many instructions from being executed before checking
  54      for events (or some such).  */
  55   unsigned int max_chain_length;
  56 #define CPU_SCACHE_MAX_CHAIN_LENGTH(cpu) ((cpu) -> cgen_cpu.scache.max_chain_length)
  57   /* Special scache entry for (re)starting bb extraction.  */
  58   SCACHE *pbb_begin;
  59 #define CPU_SCACHE_PBB_BEGIN(cpu) ((cpu) -> cgen_cpu.scache.pbb_begin)
  60   /* Hash table into cached chains.  */
  61   SCACHE_MAP *hash_table;
  62 #define CPU_SCACHE_HASH_TABLE(cpu) ((cpu) -> cgen_cpu.scache.hash_table)
  63   /* Next free entry in cache.  */
  64   SCACHE *next_free;
  65 #define CPU_SCACHE_NEXT_FREE(cpu) ((cpu) -> cgen_cpu.scache.next_free)
  66
  67   /* Kind of branch being taken.
  68      Only used by functional semantics, not switch form.  */
  69   SEM_BRANCH_TYPE pbb_br_type;
  70 #define CPU_PBB_BR_TYPE(cpu) ((cpu) -> cgen_cpu.scache.pbb_br_type)
  71   /* Target's branch address.  */
  72   IADDR pbb_br_npc;
  73 #define CPU_PBB_BR_NPC(cpu) ((cpu) -> cgen_cpu.scache.pbb_br_npc)
  74 #endif /* WITH_SCACHE_PBB */
  75
  76 #if WITH_PROFILE_SCACHE_P
  77   /* Cache hits, misses.  */
  78   unsigned long hits, misses;
  79 #define CPU_SCACHE_HITS(cpu) ((cpu) -> cgen_cpu.scache.hits)
  80 #define CPU_SCACHE_MISSES(cpu) ((cpu) -> cgen_cpu.scache.misses)
  81
  82 #if WITH_SCACHE_PBB
  83   /* Chain length counts.
  84      Each element is a count of the number of chains created with that
  85      length.  */
  86   unsigned long *chain_lengths;
  87 #define CPU_SCACHE_CHAIN_LENGTHS(cpu) ((cpu) -> cgen_cpu.scache.chain_lengths)
  88   /* Number of times cache was flushed due to its being full.  */
  89   unsigned long full_flushes;
  90 #define CPU_SCACHE_FULL_FLUSHES(cpu) ((cpu) -> cgen_cpu.scache.full_flushes)
  91 #endif
  92 #endif
  93 } CPU_SCACHE;
  94
  95 /* Hash a PC value.
  96    This is split into two parts to help with moving as much of the
  97    computation out of the main loop.  */
  98 #define CPU_SCACHE_HASH_MASK(cpu) (CPU_SCACHE_SIZE (cpu) - 1)
  99 #define SCACHE_HASH_PC(pc, mask) \
 100 ((CGEN_MIN_INSN_SIZE == 2 ? ((pc) >> 1) \
 101   : CGEN_MIN_INSN_SIZE == 4 ? ((pc) >> 2) \
 102   : (pc)) \
 103  & (mask))
 104
 105 /* Non-zero if cache is in use.  */
 106 #define USING_SCACHE_P(sd) (STATE_SCACHE_SIZE (sd) > 0)
 107
 108 /* Lookup a PC value in the scache [compilation only].  */
 109 extern SCACHE * scache_lookup (SIM_CPU *, IADDR);
 110 /* Return a pointer to at least N buffers.  */
 111 extern SCACHE *scache_lookup_or_alloc (SIM_CPU *, IADDR, int, SCACHE **);
 112 /* Flush all cpu's scaches.  */
 113 extern void scache_flush (SIM_DESC);
 114 /* Flush a cpu's scache.  */
 115 extern void scache_flush_cpu (SIM_CPU *);
 116 \f
 117 /* Scache profiling support.  */
 118
 119 /* Print summary scache usage information.  */
 120 extern void scache_print_profile (SIM_CPU *cpu, bool verbose);
 121
 122 #if WITH_PROFILE_SCACHE_P
 123
 124 #define PROFILE_COUNT_SCACHE_HIT(cpu) \
 125 do { \
 126   if (CPU_PROFILE_FLAGS (cpu) [PROFILE_SCACHE_IDX]) \
 127     ++ CPU_SCACHE_HITS (cpu); \
 128 } while (0)
 129 #define PROFILE_COUNT_SCACHE_MISS(cpu) \
 130 do { \
 131   if (CPU_PROFILE_FLAGS (cpu) [PROFILE_SCACHE_IDX]) \
 132     ++ CPU_SCACHE_MISSES (cpu); \
 133 } while (0)
 134 #define PROFILE_COUNT_SCACHE_CHAIN_LENGTH(cpu,length) \
 135 do { \
 136   if (CPU_PROFILE_FLAGS (cpu) [PROFILE_SCACHE_IDX]) \
 137     ++ CPU_SCACHE_CHAIN_LENGTHS (cpu) [length]; \
 138 } while (0)
 139 #define PROFILE_COUNT_SCACHE_FULL_FLUSH(cpu) \
 140 do { \
 141   if (CPU_PROFILE_FLAGS (cpu) [PROFILE_SCACHE_IDX]) \
 142     ++ CPU_SCACHE_FULL_FLUSHES (cpu); \
 143 } while (0)
 144
 145 #else
 146
 147 #define PROFILE_COUNT_SCACHE_HIT(cpu)
 148 #define PROFILE_COUNT_SCACHE_MISS(cpu)
 149 #define PROFILE_COUNT_SCACHE_CHAIN_LENGTH(cpu,length)
 150 #define PROFILE_COUNT_SCACHE_FULL_FLUSH(cpu)
 151
 152 #endif
 153
 154 #endif /* CGEN_SCACHE_H */