| 1 | /* Main simulator loop for CGEN-based simulators. |
| 2 | Copyright (C) 1998-2021 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 | /* ??? These are old notes, kept around for now. |
| 21 | Collecting profile data and tracing slow us down so we don't do them in |
| 22 | "fast mode". |
| 23 | There are 6 possibilities on 2 axes: |
| 24 | - no-scaching, insn-scaching, basic-block-scaching |
| 25 | - run with full features or run fast |
| 26 | Supporting all six possibilities in one executable is a bit much but |
| 27 | supporting full/fast seems reasonable. |
| 28 | If the scache is configured in it is always used. |
| 29 | If pbb-scaching is configured in it is always used. |
| 30 | ??? Sometimes supporting more than one set of semantic functions will make |
| 31 | the simulator too large - this should be configurable. Blah blah blah. |
| 32 | ??? Supporting full/fast can be more modular, blah blah blah. |
| 33 | When the framework is more modular, this can be. |
| 34 | */ |
| 35 | |
| 36 | /* This must come before any other includes. */ |
| 37 | #include "defs.h" |
| 38 | |
| 39 | #include "sim-main.h" |
| 40 | #include "sim-assert.h" |
| 41 | #include "sim-signal.h" |
| 42 | |
| 43 | #ifndef SIM_ENGINE_PREFIX_HOOK |
| 44 | #define SIM_ENGINE_PREFIX_HOOK(sd) |
| 45 | #endif |
| 46 | #ifndef SIM_ENGINE_POSTFIX_HOOK |
| 47 | #define SIM_ENGINE_POSTFIX_HOOK(sd) |
| 48 | #endif |
| 49 | |
| 50 | static sim_event_handler has_stepped; |
| 51 | static void prime_cpu (SIM_CPU *, int); |
| 52 | static void engine_run_1 (SIM_DESC, int, int); |
| 53 | static void engine_run_n (SIM_DESC, int, int, int, int); |
| 54 | |
| 55 | /* If no profiling or tracing has been enabled, run in fast mode. */ |
| 56 | static int |
| 57 | cgen_get_fast_p (SIM_DESC sd) |
| 58 | { |
| 59 | int i, c; |
| 60 | int run_fast_p = 1; |
| 61 | |
| 62 | for (c = 0; c < MAX_NR_PROCESSORS; ++c) |
| 63 | { |
| 64 | SIM_CPU *cpu = STATE_CPU (sd, c); |
| 65 | |
| 66 | if (PROFILE_ANY_P (cpu) || TRACE_ANY_P (cpu)) |
| 67 | return 0; |
| 68 | } |
| 69 | |
| 70 | return 1; |
| 71 | } |
| 72 | |
| 73 | /* sim_resume for cgen */ |
| 74 | |
| 75 | void |
| 76 | sim_resume (SIM_DESC sd, int step, int siggnal) |
| 77 | { |
| 78 | sim_engine *engine = STATE_ENGINE (sd); |
| 79 | jmp_buf buf; |
| 80 | int jmpval; |
| 81 | static int fast_p = -1; |
| 82 | |
| 83 | ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER); |
| 84 | |
| 85 | if (fast_p == -1) |
| 86 | fast_p = cgen_get_fast_p (sd); |
| 87 | |
| 88 | /* we only want to be single stepping the simulator once */ |
| 89 | if (engine->stepper != NULL) |
| 90 | { |
| 91 | sim_events_deschedule (sd, engine->stepper); |
| 92 | engine->stepper = NULL; |
| 93 | } |
| 94 | if (step) |
| 95 | engine->stepper = sim_events_schedule (sd, 1, has_stepped, sd); |
| 96 | |
| 97 | sim_module_resume (sd); |
| 98 | |
| 99 | #if WITH_SCACHE |
| 100 | if (USING_SCACHE_P (sd)) |
| 101 | scache_flush (sd); |
| 102 | #endif |
| 103 | |
| 104 | /* run/resume the simulator */ |
| 105 | |
| 106 | sim_engine_set_run_state (sd, sim_running, 0); |
| 107 | |
| 108 | engine->jmpbuf = &buf; |
| 109 | jmpval = setjmp (buf); |
| 110 | if (jmpval == sim_engine_start_jmpval |
| 111 | || jmpval == sim_engine_restart_jmpval) |
| 112 | { |
| 113 | int last_cpu_nr = sim_engine_last_cpu_nr (sd); |
| 114 | int next_cpu_nr = sim_engine_next_cpu_nr (sd); |
| 115 | int nr_cpus = sim_engine_nr_cpus (sd); |
| 116 | /* ??? Setting max_insns to 0 allows pbb/jit code to run wild and is |
| 117 | useful if all one wants to do is run a benchmark. Need some better |
| 118 | way to identify this case. */ |
| 119 | int max_insns = (step |
| 120 | ? 1 |
| 121 | : (nr_cpus == 1 |
| 122 | /*&& wip:no-events*/ |
| 123 | /* Don't do this if running under gdb, need to |
| 124 | poll ui for events. */ |
| 125 | && STATE_OPEN_KIND (sd) == SIM_OPEN_STANDALONE) |
| 126 | ? 0 |
| 127 | : 8); /*FIXME: magic number*/ |
| 128 | |
| 129 | sim_events_preprocess (sd, last_cpu_nr >= nr_cpus, next_cpu_nr >= nr_cpus); |
| 130 | if (next_cpu_nr >= nr_cpus) |
| 131 | next_cpu_nr = 0; |
| 132 | if (nr_cpus == 1) |
| 133 | engine_run_1 (sd, max_insns, fast_p); |
| 134 | else |
| 135 | engine_run_n (sd, next_cpu_nr, nr_cpus, max_insns, fast_p); |
| 136 | } |
| 137 | #if 1 /*wip*/ |
| 138 | else |
| 139 | { |
| 140 | /* Account for the last insn executed. */ |
| 141 | SIM_CPU *cpu = STATE_CPU (sd, sim_engine_last_cpu_nr (sd)); |
| 142 | ++ CPU_INSN_COUNT (cpu); |
| 143 | CGEN_TRACE_INSN_FINI (cpu, NULL, 1); |
| 144 | } |
| 145 | #endif |
| 146 | |
| 147 | engine->jmpbuf = NULL; |
| 148 | |
| 149 | { |
| 150 | int i; |
| 151 | int nr_cpus = sim_engine_nr_cpus (sd); |
| 152 | |
| 153 | #if 0 /*wip,ignore*/ |
| 154 | /* If the loop exits, either we single-stepped or @cpu@_engine_stop |
| 155 | was called. */ |
| 156 | if (step) |
| 157 | sim_engine_set_run_state (sd, sim_stopped, SIM_SIGTRAP); |
| 158 | else |
| 159 | sim_engine_set_run_state (sd, pending_reason, pending_sigrc); |
| 160 | #endif |
| 161 | |
| 162 | for (i = 0; i < nr_cpus; ++i) |
| 163 | { |
| 164 | SIM_CPU *cpu = STATE_CPU (sd, i); |
| 165 | |
| 166 | PROFILE_TOTAL_INSN_COUNT (CPU_PROFILE_DATA (cpu)) += CPU_INSN_COUNT (cpu); |
| 167 | } |
| 168 | } |
| 169 | |
| 170 | sim_module_suspend (sd); |
| 171 | } |
| 172 | |
| 173 | /* Halt the simulator after just one instruction. */ |
| 174 | |
| 175 | static void |
| 176 | has_stepped (SIM_DESC sd, void *data) |
| 177 | { |
| 178 | ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER); |
| 179 | sim_engine_halt (sd, NULL, NULL, NULL_CIA, sim_stopped, SIM_SIGTRAP); |
| 180 | } |
| 181 | |
| 182 | /* Prepare a cpu for running. |
| 183 | MAX_INSNS is the number of insns to execute per time slice. |
| 184 | If 0 it means the cpu can run as long as it wants (e.g. until the |
| 185 | program completes). |
| 186 | ??? Perhaps this should be an argument to the engine_fn. */ |
| 187 | |
| 188 | static void |
| 189 | prime_cpu (SIM_CPU *cpu, int max_insns) |
| 190 | { |
| 191 | CPU_MAX_SLICE_INSNS (cpu) = max_insns; |
| 192 | CPU_INSN_COUNT (cpu) = 0; |
| 193 | |
| 194 | /* Initialize the insn descriptor table. |
| 195 | This has to be done after all initialization so we just defer it to |
| 196 | here. */ |
| 197 | |
| 198 | if (MACH_PREPARE_RUN (CPU_MACH (cpu))) |
| 199 | (* MACH_PREPARE_RUN (CPU_MACH (cpu))) (cpu); |
| 200 | } |
| 201 | |
| 202 | /* Main loop, for 1 cpu. */ |
| 203 | |
| 204 | static void |
| 205 | engine_run_1 (SIM_DESC sd, int max_insns, int fast_p) |
| 206 | { |
| 207 | sim_cpu *cpu = STATE_CPU (sd, 0); |
| 208 | ENGINE_FN *fn = fast_p ? CPU_FAST_ENGINE_FN (cpu) : CPU_FULL_ENGINE_FN (cpu); |
| 209 | |
| 210 | prime_cpu (cpu, max_insns); |
| 211 | |
| 212 | while (1) |
| 213 | { |
| 214 | SIM_ENGINE_PREFIX_HOOK (sd); |
| 215 | |
| 216 | (*fn) (cpu); |
| 217 | |
| 218 | SIM_ENGINE_POSTFIX_HOOK (sd); |
| 219 | |
| 220 | /* process any events */ |
| 221 | if (sim_events_tick (sd)) |
| 222 | sim_events_process (sd); |
| 223 | } |
| 224 | } |
| 225 | |
| 226 | /* Main loop, for multiple cpus. */ |
| 227 | |
| 228 | static void |
| 229 | engine_run_n (SIM_DESC sd, int next_cpu_nr, int nr_cpus, int max_insns, int fast_p) |
| 230 | { |
| 231 | int i; |
| 232 | ENGINE_FN *engine_fns[MAX_NR_PROCESSORS]; |
| 233 | |
| 234 | for (i = 0; i < nr_cpus; ++i) |
| 235 | { |
| 236 | SIM_CPU *cpu = STATE_CPU (sd, i); |
| 237 | |
| 238 | engine_fns[i] = fast_p ? CPU_FAST_ENGINE_FN (cpu) : CPU_FULL_ENGINE_FN (cpu); |
| 239 | prime_cpu (cpu, max_insns); |
| 240 | } |
| 241 | |
| 242 | while (1) |
| 243 | { |
| 244 | SIM_ENGINE_PREFIX_HOOK (sd); |
| 245 | |
| 246 | /* FIXME: proper cycling of all of them, blah blah blah. */ |
| 247 | while (next_cpu_nr != nr_cpus) |
| 248 | { |
| 249 | SIM_CPU *cpu = STATE_CPU (sd, next_cpu_nr); |
| 250 | |
| 251 | (* engine_fns[next_cpu_nr]) (cpu); |
| 252 | ++next_cpu_nr; |
| 253 | } |
| 254 | |
| 255 | SIM_ENGINE_POSTFIX_HOOK (sd); |
| 256 | |
| 257 | /* process any events */ |
| 258 | if (sim_events_tick (sd)) |
| 259 | sim_events_process (sd); |
| 260 | } |
| 261 | } |