xref: /netbsd-src/external/gpl3/gdb/dist/sim/common/cgen-scache.h (revision 0d3e0572e40d81edb4fdbff937458d47b685c34c)
1 /* Simulator header for cgen scache support.
2    Copyright (C) 1998-2024 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 
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 */
155