sim/common/cgen-run.c

   1 /* Main simulator loop for CGEN-based simulators.
   2    Copyright (C) 1998 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 2, or (at your option)
  10 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 along
  18 with this program; if not, write to the Free Software Foundation, Inc.,
  19 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  20
  21 /* ??? These are old notes, kept around for now.
  22    Collecting profile data and tracing slow us down so we don't do them in
  23    "fast mode".
  24    There are 6 possibilities on 2 axes:
  25    - no-scaching, insn-scaching, basic-block-scaching
  26    - run with full features or run fast
  27    Supporting all six possibilities in one executable is a bit much but
  28    supporting full/fast seems reasonable.
  29    If the scache is configured in it is always used.
  30    If pbb-scaching is configured in it is always used.
  31    ??? Sometimes supporting more than one set of semantic functions will make
  32    the simulator too large - this should be configurable.  Blah blah blah.
  33    ??? Supporting full/fast can be more modular, blah blah blah.
  34    When the framework is more modular, this can be.
  35 */
  36
  37 #include "sim-main.h"
  38 #include "sim-assert.h"
  39
  40 #ifndef SIM_ENGINE_PREFIX_HOOK
  41 #define SIM_ENGINE_PREFIX_HOOK(sd)
  42 #endif
  43 #ifndef SIM_ENGINE_POSTFIX_HOOK
  44 #define SIM_ENGINE_POSTFIX_HOOK(sd)
  45 #endif
  46
  47 static sim_event_handler has_stepped;
  48 static void prime_cpu (SIM_CPU *, int);
  49 static void engine_run_1 (SIM_DESC, int, int);
  50 static void engine_run_n (SIM_DESC, int, int, int, int);
  51
  52 /* sim_resume for cgen */
  53
  54 void
  55 sim_resume (SIM_DESC sd, int step, int siggnal)
  56 {
  57   sim_engine *engine = STATE_ENGINE (sd);
  58   jmp_buf buf;
  59   int jmpval;
  60
  61   ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER);
  62
  63   /* we only want to be single stepping the simulator once */
  64   if (engine->stepper != NULL)
  65     {
  66       sim_events_deschedule (sd, engine->stepper);
  67       engine->stepper = NULL;
  68     }
  69   if (step)
  70     engine->stepper = sim_events_schedule (sd, 1, has_stepped, sd);
  71
  72   sim_module_resume (sd);
  73
  74 #if WITH_SCACHE
  75   if (USING_SCACHE_P (sd))
  76     scache_flush (sd);
  77 #endif
  78
  79   /* run/resume the simulator */
  80
  81   sim_engine_set_run_state (sd, sim_running, 0);
  82
  83   engine->jmpbuf = &buf;
  84   jmpval = setjmp (buf);
  85   if (jmpval == sim_engine_start_jmpval
  86       || jmpval == sim_engine_restart_jmpval)
  87     {
  88       int last_cpu_nr = sim_engine_last_cpu_nr (sd);
  89       int next_cpu_nr = sim_engine_next_cpu_nr (sd);
  90       int nr_cpus = sim_engine_nr_cpus (sd);
  91       /* ??? Setting max_insns to 0 allows pbb/jit code to run wild and is
  92          useful if all one wants to do is run a benchmark.  Need some better
  93          way to identify this case.  */
  94       int max_insns = (step
  95                        ? 1
  96                        : (nr_cpus == 1 /*&& wip:no-events*/)
  97                        ? 0
  98                        : 4); /*FIXME: magic number*/
  99       int fast_p = STATE_RUN_FAST_P (sd);
 100
 101       sim_events_preprocess (sd, last_cpu_nr >= nr_cpus, next_cpu_nr >= nr_cpus);
 102       if (next_cpu_nr >= nr_cpus)
 103         next_cpu_nr = 0;
 104       if (nr_cpus == 1)
 105         engine_run_1 (sd, max_insns, fast_p);
 106       else
 107         engine_run_n (sd, next_cpu_nr, nr_cpus, max_insns, fast_p);
 108     }
 109 #if 1 /*wip*/
 110   else
 111     {
 112       /* Account for the last insn executed.  */
 113       SIM_CPU *cpu = STATE_CPU (sd, sim_engine_last_cpu_nr (sd));
 114       ++ CPU_INSN_COUNT (cpu);
 115       TRACE_INSN_FINI (cpu, NULL, 1);
 116     }
 117 #endif
 118
 119   engine->jmpbuf = NULL;
 120
 121   {
 122     int i;
 123     int nr_cpus = sim_engine_nr_cpus (sd);
 124
 125 #if 0 /*wip,ignore*/
 126     /* If the loop exits, either we single-stepped or @cpu@_engine_stop
 127        was called.  */
 128     if (step)
 129       sim_engine_set_run_state (sd, sim_stopped, SIM_SIGTRAP);
 130     else
 131       sim_engine_set_run_state (sd, pending_reason, pending_sigrc);
 132 #endif
 133
 134     for (i = 0; i < nr_cpus; ++i)
 135       {
 136         SIM_CPU *cpu = STATE_CPU (sd, i);
 137
 138         PROFILE_TOTAL_INSN_COUNT (CPU_PROFILE_DATA (cpu)) += CPU_INSN_COUNT (cpu);
 139       }
 140   }
 141
 142   sim_module_suspend (sd);
 143 }
 144
 145 /* Halt the simulator after just one instruction.  */
 146
 147 static void
 148 has_stepped (SIM_DESC sd, void *data)
 149 {
 150   ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER);
 151   sim_engine_halt (sd, NULL, NULL, NULL_CIA, sim_stopped, SIM_SIGTRAP);
 152 }
 153
 154 /* Prepare a cpu for running.
 155    MAX_INSNS is the number of insns to execute per time slice.
 156    If 0 it means the cpu can run as long as it wants (e.g. until the
 157    program completes).
 158    ??? Perhaps this should be an argument to the engine_fn.  */
 159
 160 static void
 161 prime_cpu (SIM_CPU *cpu, int max_insns)
 162 {
 163   CPU_MAX_SLICE_INSNS (cpu) = max_insns;
 164   CPU_INSN_COUNT (cpu) = 0;
 165
 166   /* Initialize the insn descriptor table.
 167      This has to be done after all initialization so we just defer it to
 168      here.  */
 169
 170   if (MACH_PREPARE_RUN (CPU_MACH (cpu)))
 171     (* MACH_PREPARE_RUN (CPU_MACH (cpu))) (cpu);
 172 }
 173
 174 /* Main loop, for 1 cpu.  */
 175
 176 static void
 177 engine_run_1 (SIM_DESC sd, int max_insns, int fast_p)
 178 {
 179   sim_cpu *cpu = STATE_CPU (sd, 0);
 180   ENGINE_FN *fn = fast_p ? CPU_FAST_ENGINE_FN (cpu) : CPU_FULL_ENGINE_FN (cpu);
 181
 182   prime_cpu (cpu, max_insns);
 183
 184   while (1)
 185     {
 186       SIM_ENGINE_PREFIX_HOOK (sd);
 187
 188       (*fn) (cpu);
 189
 190       SIM_ENGINE_POSTFIX_HOOK (sd);
 191
 192       /* process any events */
 193       if (sim_events_tick (sd))
 194         sim_events_process (sd);
 195     }
 196 }
 197
 198 /* Main loop, for multiple cpus.  */
 199
 200 static void
 201 engine_run_n (SIM_DESC sd, int next_cpu_nr, int nr_cpus, int max_insns, int fast_p)
 202 {
 203   int i;
 204   ENGINE_FN *engine_fns[MAX_NR_PROCESSORS];
 205
 206   for (i = 0; i < nr_cpus; ++i)
 207     {
 208       SIM_CPU *cpu = STATE_CPU (sd, i);
 209
 210       engine_fns[i] = fast_p ? CPU_FAST_ENGINE_FN (cpu) : CPU_FULL_ENGINE_FN (cpu);
 211       prime_cpu (cpu, max_insns);
 212     }
 213
 214   while (1)
 215     {
 216       SIM_ENGINE_PREFIX_HOOK (sd);
 217
 218       /* FIXME: proper cycling of all of them, blah blah blah.  */
 219       while (next_cpu_nr != nr_cpus)
 220         {
 221           SIM_CPU *cpu = STATE_CPU (sd, next_cpu_nr);
 222
 223           (* engine_fns[next_cpu_nr]) (cpu);
 224           ++next_cpu_nr;
 225         }
 226
 227       SIM_ENGINE_POSTFIX_HOOK (sd);
 228
 229       /* process any events */
 230       if (sim_events_tick (sd))
 231         sim_events_process (sd);
 232     }
 233 }