sim/common/cgen-scache.h

   1 /* Simulator header for cgen scache support.
   2    Copyright (C) 1998-2020 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 #ifndef WITH_SCACHE
  24 #define WITH_SCACHE 0
  25 #endif
  26
  27 /* When caching bb's, instructions are extracted into "chains".
  28    SCACHE_MAP is a hash table into these chains.  */
  29
  30 typedef struct {
  31   IADDR pc;
  32   SCACHE *sc;
  33 } SCACHE_MAP;
  34
  35 typedef struct cpu_scache {
  36   /* Simulator cache size.  Must be a power of 2.
  37      This is the number of elements in the `cache' member.  */
  38   unsigned int size;
  39 #define CPU_SCACHE_SIZE(cpu) ((cpu) -> cgen_cpu.scache.size)
  40   /* The cache.  */
  41   SCACHE *cache;
  42 #define CPU_SCACHE_CACHE(cpu) ((cpu) -> cgen_cpu.scache.cache)
  43
  44 #if WITH_SCACHE_PBB
  45   /* Number of hash chains.  Must be a power of 2.  */
  46   unsigned int num_hash_chains;
  47 #define CPU_SCACHE_NUM_HASH_CHAINS(cpu) ((cpu) -> cgen_cpu.scache.num_hash_chains)
  48   /* Number of entries in each hash chain.
  49      The hash table is a statically allocated NxM array where
  50      N = num_hash_chains
  51      M = num_hash_chain_entries.  */
  52   unsigned int num_hash_chain_entries;
  53 #define CPU_SCACHE_NUM_HASH_CHAIN_ENTRIES(cpu) ((cpu) -> cgen_cpu.scache.num_hash_chain_entries)
  54   /* Maximum number of instructions in a chain.
  55      ??? This just let's us set a static size of chain_lengths table.
  56      In a simulation that handles more than just the cpu, this might also be
  57      used to keep too many instructions from being executed before checking
  58      for events (or some such).  */
  59   unsigned int max_chain_length;
  60 #define CPU_SCACHE_MAX_CHAIN_LENGTH(cpu) ((cpu) -> cgen_cpu.scache.max_chain_length)
  61   /* Special scache entry for (re)starting bb extraction.  */
  62   SCACHE *pbb_begin;
  63 #define CPU_SCACHE_PBB_BEGIN(cpu) ((cpu) -> cgen_cpu.scache.pbb_begin)
  64   /* Hash table into cached chains.  */
  65   SCACHE_MAP *hash_table;
  66 #define CPU_SCACHE_HASH_TABLE(cpu) ((cpu) -> cgen_cpu.scache.hash_table)
  67   /* Next free entry in cache.  */
  68   SCACHE *next_free;
  69 #define CPU_SCACHE_NEXT_FREE(cpu) ((cpu) -> cgen_cpu.scache.next_free)
  70
  71   /* Kind of branch being taken.
  72      Only used by functional semantics, not switch form.  */
  73   SEM_BRANCH_TYPE pbb_br_type;
  74 #define CPU_PBB_BR_TYPE(cpu) ((cpu) -> cgen_cpu.scache.pbb_br_type)
  75   /* Target's branch address.  */
  76   IADDR pbb_br_npc;
  77 #define CPU_PBB_BR_NPC(cpu) ((cpu) -> cgen_cpu.scache.pbb_br_npc)
  78 #endif /* WITH_SCACHE_PBB */
  79
  80 #if WITH_PROFILE_SCACHE_P
  81   /* Cache hits, misses.  */
  82   unsigned long hits, misses;
  83 #define CPU_SCACHE_HITS(cpu) ((cpu) -> cgen_cpu.scache.hits)
  84 #define CPU_SCACHE_MISSES(cpu) ((cpu) -> cgen_cpu.scache.misses)
  85
  86 #if WITH_SCACHE_PBB
  87   /* Chain length counts.
  88      Each element is a count of the number of chains created with that
  89      length.  */
  90   unsigned long *chain_lengths;
  91 #define CPU_SCACHE_CHAIN_LENGTHS(cpu) ((cpu) -> cgen_cpu.scache.chain_lengths)
  92   /* Number of times cache was flushed due to its being full.  */
  93   unsigned long full_flushes;
  94 #define CPU_SCACHE_FULL_FLUSHES(cpu) ((cpu) -> cgen_cpu.scache.full_flushes)
  95 #endif
  96 #endif
  97 } CPU_SCACHE;
  98
  99 /* Hash a PC value.
 100    This is split into two parts to help with moving as much of the
 101    computation out of the main loop.  */
 102 #define CPU_SCACHE_HASH_MASK(cpu) (CPU_SCACHE_SIZE (cpu) - 1)
 103 #define SCACHE_HASH_PC(pc, mask) \
 104 ((CGEN_MIN_INSN_SIZE == 2 ? ((pc) >> 1) \
 105   : CGEN_MIN_INSN_SIZE == 4 ? ((pc) >> 2) \
 106   : (pc)) \
 107  & (mask))
 108
 109 /* Non-zero if cache is in use.  */
 110 #define USING_SCACHE_P(sd) (STATE_SCACHE_SIZE (sd) > 0)
 111
 112 /* Install the simulator cache into the simulator.  */
 113 MODULE_INSTALL_FN scache_install;
 114
 115 /* Lookup a PC value in the scache [compilation only].  */
 116 extern SCACHE * scache_lookup (SIM_CPU *, IADDR);
 117 /* Return a pointer to at least N buffers.  */
 118 extern SCACHE *scache_lookup_or_alloc (SIM_CPU *, IADDR, int, SCACHE **);
 119 /* Flush all cpu's scaches.  */
 120 extern void scache_flush (SIM_DESC);
 121 /* Flush a cpu's scache.  */
 122 extern void scache_flush_cpu (SIM_CPU *);
 123 \f
 124 /* Scache profiling support.  */
 125
 126 /* Print summary scache usage information.  */
 127 extern void scache_print_profile (SIM_CPU *cpu, int verbose);
 128
 129 #if WITH_PROFILE_SCACHE_P
 130
 131 #define PROFILE_COUNT_SCACHE_HIT(cpu) \
 132 do { \
 133   if (CPU_PROFILE_FLAGS (cpu) [PROFILE_SCACHE_IDX]) \
 134     ++ CPU_SCACHE_HITS (cpu); \
 135 } while (0)
 136 #define PROFILE_COUNT_SCACHE_MISS(cpu) \
 137 do { \
 138   if (CPU_PROFILE_FLAGS (cpu) [PROFILE_SCACHE_IDX]) \
 139     ++ CPU_SCACHE_MISSES (cpu); \
 140 } while (0)
 141 #define PROFILE_COUNT_SCACHE_CHAIN_LENGTH(cpu,length) \
 142 do { \
 143   if (CPU_PROFILE_FLAGS (cpu) [PROFILE_SCACHE_IDX]) \
 144     ++ CPU_SCACHE_CHAIN_LENGTHS (cpu) [length]; \
 145 } while (0)
 146 #define PROFILE_COUNT_SCACHE_FULL_FLUSH(cpu) \
 147 do { \
 148   if (CPU_PROFILE_FLAGS (cpu) [PROFILE_SCACHE_IDX]) \
 149     ++ CPU_SCACHE_FULL_FLUSHES (cpu); \
 150 } while (0)
 151
 152 #else
 153
 154 #define PROFILE_COUNT_SCACHE_HIT(cpu)
 155 #define PROFILE_COUNT_SCACHE_MISS(cpu)
 156 #define PROFILE_COUNT_SCACHE_CHAIN_LENGTH(cpu,length)
 157 #define PROFILE_COUNT_SCACHE_FULL_FLUSH(cpu)
 158
 159 #endif
 160
 161 #endif /* CGEN_SCACHE_H */