sim/common/cgen-run.c - binutils-gdb - Git at Google

 /* Main simulator loop for CGEN-based simulators.
    Copyright (C) 1998-2023 Free Software Foundation, Inc.
    Contributed by Cygnus Solutions.

 This file is part of GDB, the GNU debugger.

 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 3 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

 /* ??? These are old notes, kept around for now.
    Collecting profile data and tracing slow us down so we don't do them in
    "fast mode".
    There are 6 possibilities on 2 axes:
    - no-scaching, insn-scaching, basic-block-scaching
    - run with full features or run fast
    Supporting all six possibilities in one executable is a bit much but
    supporting full/fast seems reasonable.
    If the scache is configured in it is always used.
    If pbb-scaching is configured in it is always used.
    ??? Sometimes supporting more than one set of semantic functions will make
    the simulator too large - this should be configurable.  Blah blah blah.
    ??? Supporting full/fast can be more modular, blah blah blah.
    When the framework is more modular, this can be.
 */

 /* This must come before any other includes.  */
 #include "defs.h"

 #include "sim-main.h"
 #include "sim-assert.h"
 #include "sim-signal.h"

 #ifndef SIM_ENGINE_PREFIX_HOOK
 #define SIM_ENGINE_PREFIX_HOOK(sd)
 #endif
 #ifndef SIM_ENGINE_POSTFIX_HOOK
 #define SIM_ENGINE_POSTFIX_HOOK(sd)
 #endif

 static sim_event_handler has_stepped;
 static void prime_cpu (SIM_CPU *, int);
 static void engine_run_1 (SIM_DESC, int, int);
 static void engine_run_n (SIM_DESC, int, int, int, int);

 /* If no profiling or tracing has been enabled, run in fast mode.  */
 static int
 cgen_get_fast_p (SIM_DESC sd)
 {
   int i, c;
   int run_fast_p = 1;

   for (c = 0; c < MAX_NR_PROCESSORS; ++c)
     {
       SIM_CPU *cpu = STATE_CPU (sd, c);

       if (PROFILE_ANY_P (cpu) || TRACE_ANY_P (cpu))
 	return 0;
     }

   return 1;
 }

 /* sim_resume for cgen */

 void
 sim_resume (SIM_DESC sd, int step, int siggnal)
 {
   sim_engine *engine = STATE_ENGINE (sd);
   jmp_buf buf;
   int jmpval;
   static int fast_p = -1;

   ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER);

   if (fast_p == -1)
     fast_p = cgen_get_fast_p (sd);

   /* we only want to be single stepping the simulator once */
   if (engine->stepper != NULL)
     {
       sim_events_deschedule (sd, engine->stepper);
       engine->stepper = NULL;
     }
   if (step)
     engine->stepper = sim_events_schedule (sd, 1, has_stepped, sd);

   sim_module_resume (sd);

 #if WITH_SCACHE
   if (USING_SCACHE_P (sd))
     scache_flush (sd);
 #endif

   /* run/resume the simulator */

   sim_engine_set_run_state (sd, sim_running, 0);

   engine->jmpbuf = &buf;
   jmpval = setjmp (buf);
   if (jmpval == sim_engine_start_jmpval
       || jmpval == sim_engine_restart_jmpval)
     {
       int last_cpu_nr = sim_engine_last_cpu_nr (sd);
       int next_cpu_nr = sim_engine_next_cpu_nr (sd);
       int nr_cpus = sim_engine_nr_cpus (sd);
       /* ??? Setting max_insns to 0 allows pbb/jit code to run wild and is
 	 useful if all one wants to do is run a benchmark.  Need some better
 	 way to identify this case.  */
       int max_insns = (step
 		       ? 1
 		       : (nr_cpus == 1
 			  /*&& wip:no-events*/
 			  /* Don't do this if running under gdb, need to
 			     poll ui for events.  */
 			  && STATE_OPEN_KIND (sd) == SIM_OPEN_STANDALONE)
 		       ? 0
 		       : 8); /*FIXME: magic number*/

       sim_events_preprocess (sd, last_cpu_nr >= nr_cpus, next_cpu_nr >= nr_cpus);
       if (next_cpu_nr >= nr_cpus)
 	next_cpu_nr = 0;
       if (nr_cpus == 1)
 	engine_run_1 (sd, max_insns, fast_p);
       else
 	engine_run_n (sd, next_cpu_nr, nr_cpus, max_insns, fast_p);
     }
 #if 1 /*wip*/
   else
     {
       /* Account for the last insn executed.  */
       SIM_CPU *cpu = STATE_CPU (sd, sim_engine_last_cpu_nr (sd));
       ++ CPU_INSN_COUNT (cpu);
       CGEN_TRACE_INSN_FINI (cpu, NULL, 1);
     }
 #endif

   engine->jmpbuf = NULL;

   {
     int i;
     int nr_cpus = sim_engine_nr_cpus (sd);

 #if 0 /*wip,ignore*/
     /* If the loop exits, either we single-stepped or @cpu@_engine_stop
        was called.  */
     if (step)
       sim_engine_set_run_state (sd, sim_stopped, SIM_SIGTRAP);
     else
       sim_engine_set_run_state (sd, pending_reason, pending_sigrc);
 #endif

     for (i = 0; i < nr_cpus; ++i)
       {
 	SIM_CPU *cpu = STATE_CPU (sd, i);

 	PROFILE_TOTAL_INSN_COUNT (CPU_PROFILE_DATA (cpu)) += CPU_INSN_COUNT (cpu);
       }
   }

   sim_module_suspend (sd);
 }

 /* Halt the simulator after just one instruction.  */

 static void
 has_stepped (SIM_DESC sd, void *data)
 {
   ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER);
   sim_engine_halt (sd, NULL, NULL, NULL_CIA, sim_stopped, SIM_SIGTRAP);
 }

 /* Prepare a cpu for running.
    MAX_INSNS is the number of insns to execute per time slice.
    If 0 it means the cpu can run as long as it wants (e.g. until the
    program completes).
    ??? Perhaps this should be an argument to the engine_fn.  */

 static void
 prime_cpu (SIM_CPU *cpu, int max_insns)
 {
   CPU_MAX_SLICE_INSNS (cpu) = max_insns;
   CPU_INSN_COUNT (cpu) = 0;

   /* Initialize the insn descriptor table.
      This has to be done after all initialization so we just defer it to
      here.  */

   if (MACH_PREPARE_RUN (CPU_MACH (cpu)))
     (* MACH_PREPARE_RUN (CPU_MACH (cpu))) (cpu);
 }

 /* Main loop, for 1 cpu.  */

 static void
 engine_run_1 (SIM_DESC sd, int max_insns, int fast_p)
 {
   sim_cpu *cpu = STATE_CPU (sd, 0);
   ENGINE_FN *fn = fast_p ? CPU_FAST_ENGINE_FN (cpu) : CPU_FULL_ENGINE_FN (cpu);

   prime_cpu (cpu, max_insns);

   while (1)
     {
       SIM_ENGINE_PREFIX_HOOK (sd);

       (*fn) (cpu);

       SIM_ENGINE_POSTFIX_HOOK (sd);

       /* process any events */
       if (sim_events_tick (sd))
 	sim_events_process (sd);
     }
 }

 /* Main loop, for multiple cpus.  */

 static void
 engine_run_n (SIM_DESC sd, int next_cpu_nr, int nr_cpus, int max_insns, int fast_p)
 {
   int i;
   /* Ensure that engine_fns is fully initialized, this silences a compiler
      warning when engine_fns is used below.  */
   ENGINE_FN *engine_fns[MAX_NR_PROCESSORS] = {};

   SIM_ASSERT (nr_cpus <= MAX_NR_PROCESSORS);
   SIM_ASSERT (next_cpu_nr >= 0 && next_cpu_nr < nr_cpus);

   for (i = 0; i < nr_cpus; ++i)
     {
       SIM_CPU *cpu = STATE_CPU (sd, i);

       engine_fns[i] = fast_p ? CPU_FAST_ENGINE_FN (cpu) : CPU_FULL_ENGINE_FN (cpu);
       prime_cpu (cpu, max_insns);
     }

   while (1)
     {
       SIM_ENGINE_PREFIX_HOOK (sd);

       /* FIXME: proper cycling of all of them, blah blah blah.  */
       while (next_cpu_nr < nr_cpus)
 	{
 	  SIM_CPU *cpu = STATE_CPU (sd, next_cpu_nr);

 	  (* engine_fns[next_cpu_nr]) (cpu);
 	  ++next_cpu_nr;
 	}

       SIM_ENGINE_POSTFIX_HOOK (sd);

       /* process any events */
       if (sim_events_tick (sd))
 	sim_events_process (sd);
     }
 }
	/* Main simulator loop for CGEN-based simulators.
	Copyright (C) 1998-2023 Free Software Foundation, Inc.
	Contributed by Cygnus Solutions.

	This file is part of GDB, the GNU debugger.

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program. If not, see <http://www.gnu.org/licenses/>. */

	/* ??? These are old notes, kept around for now.
	Collecting profile data and tracing slow us down so we don't do them in
	"fast mode".
	There are 6 possibilities on 2 axes:
	- no-scaching, insn-scaching, basic-block-scaching
	- run with full features or run fast
	Supporting all six possibilities in one executable is a bit much but
	supporting full/fast seems reasonable.
	If the scache is configured in it is always used.
	If pbb-scaching is configured in it is always used.
	??? Sometimes supporting more than one set of semantic functions will make
	the simulator too large - this should be configurable. Blah blah blah.
	??? Supporting full/fast can be more modular, blah blah blah.
	When the framework is more modular, this can be.
	*/

	/* This must come before any other includes. */
	#include "defs.h"

	#include "sim-main.h"
	#include "sim-assert.h"
	#include "sim-signal.h"

	#ifndef SIM_ENGINE_PREFIX_HOOK
	#define SIM_ENGINE_PREFIX_HOOK(sd)
	#endif
	#ifndef SIM_ENGINE_POSTFIX_HOOK
	#define SIM_ENGINE_POSTFIX_HOOK(sd)
	#endif

	static sim_event_handler has_stepped;
	static void prime_cpu (SIM_CPU *, int);
	static void engine_run_1 (SIM_DESC, int, int);
	static void engine_run_n (SIM_DESC, int, int, int, int);

	/* If no profiling or tracing has been enabled, run in fast mode. */
	static int
	cgen_get_fast_p (SIM_DESC sd)
	{
	int i, c;
	int run_fast_p = 1;

	for (c = 0; c < MAX_NR_PROCESSORS; ++c)
	{
	SIM_CPU *cpu = STATE_CPU (sd, c);

	if (PROFILE_ANY_P (cpu) \|\| TRACE_ANY_P (cpu))
	return 0;
	}

	return 1;
	}

	/* sim_resume for cgen */

	void
	sim_resume (SIM_DESC sd, int step, int siggnal)
	{
	sim_engine *engine = STATE_ENGINE (sd);
	jmp_buf buf;
	int jmpval;
	static int fast_p = -1;

	ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER);

	if (fast_p == -1)
	fast_p = cgen_get_fast_p (sd);

	/* we only want to be single stepping the simulator once */
	if (engine->stepper != NULL)
	{
	sim_events_deschedule (sd, engine->stepper);
	engine->stepper = NULL;
	}
	if (step)
	engine->stepper = sim_events_schedule (sd, 1, has_stepped, sd);

	sim_module_resume (sd);

	#if WITH_SCACHE
	if (USING_SCACHE_P (sd))
	scache_flush (sd);
	#endif

	/* run/resume the simulator */

	sim_engine_set_run_state (sd, sim_running, 0);

	engine->jmpbuf = &buf;
	jmpval = setjmp (buf);
	if (jmpval == sim_engine_start_jmpval
	\|\| jmpval == sim_engine_restart_jmpval)
	{
	int last_cpu_nr = sim_engine_last_cpu_nr (sd);
	int next_cpu_nr = sim_engine_next_cpu_nr (sd);
	int nr_cpus = sim_engine_nr_cpus (sd);
	/* ??? Setting max_insns to 0 allows pbb/jit code to run wild and is
	useful if all one wants to do is run a benchmark. Need some better
	way to identify this case. */
	int max_insns = (step
	? 1
	: (nr_cpus == 1
	/&& wip:no-events/
	/* Don't do this if running under gdb, need to
	poll ui for events. */
	&& STATE_OPEN_KIND (sd) == SIM_OPEN_STANDALONE)
	? 0
	: 8); /FIXME: magic number/

	sim_events_preprocess (sd, last_cpu_nr >= nr_cpus, next_cpu_nr >= nr_cpus);
	if (next_cpu_nr >= nr_cpus)
	next_cpu_nr = 0;
	if (nr_cpus == 1)
	engine_run_1 (sd, max_insns, fast_p);
	else
	engine_run_n (sd, next_cpu_nr, nr_cpus, max_insns, fast_p);
	}
	#if 1 /wip/
	else
	{
	/* Account for the last insn executed. */
	SIM_CPU *cpu = STATE_CPU (sd, sim_engine_last_cpu_nr (sd));
	++ CPU_INSN_COUNT (cpu);
	CGEN_TRACE_INSN_FINI (cpu, NULL, 1);
	}
	#endif

	engine->jmpbuf = NULL;

	{
	int i;
	int nr_cpus = sim_engine_nr_cpus (sd);

	#if 0 /wip,ignore/
	/* If the loop exits, either we single-stepped or @cpu@_engine_stop
	was called. */
	if (step)
	sim_engine_set_run_state (sd, sim_stopped, SIM_SIGTRAP);
	else
	sim_engine_set_run_state (sd, pending_reason, pending_sigrc);
	#endif

	for (i = 0; i < nr_cpus; ++i)
	{
	SIM_CPU *cpu = STATE_CPU (sd, i);

	PROFILE_TOTAL_INSN_COUNT (CPU_PROFILE_DATA (cpu)) += CPU_INSN_COUNT (cpu);
	}
	}

	sim_module_suspend (sd);
	}

	/* Halt the simulator after just one instruction. */

	static void
	has_stepped (SIM_DESC sd, void *data)
	{
	ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER);
	sim_engine_halt (sd, NULL, NULL, NULL_CIA, sim_stopped, SIM_SIGTRAP);
	}

	/* Prepare a cpu for running.
	MAX_INSNS is the number of insns to execute per time slice.
	If 0 it means the cpu can run as long as it wants (e.g. until the
	program completes).
	??? Perhaps this should be an argument to the engine_fn. */

	static void
	prime_cpu (SIM_CPU *cpu, int max_insns)
	{
	CPU_MAX_SLICE_INSNS (cpu) = max_insns;
	CPU_INSN_COUNT (cpu) = 0;

	/* Initialize the insn descriptor table.
	This has to be done after all initialization so we just defer it to
	here. */

	if (MACH_PREPARE_RUN (CPU_MACH (cpu)))
	(* MACH_PREPARE_RUN (CPU_MACH (cpu))) (cpu);
	}

	/* Main loop, for 1 cpu. */

	static void
	engine_run_1 (SIM_DESC sd, int max_insns, int fast_p)
	{
	sim_cpu *cpu = STATE_CPU (sd, 0);
	ENGINE_FN *fn = fast_p ? CPU_FAST_ENGINE_FN (cpu) : CPU_FULL_ENGINE_FN (cpu);

	prime_cpu (cpu, max_insns);

	while (1)
	{
	SIM_ENGINE_PREFIX_HOOK (sd);

	(*fn) (cpu);

	SIM_ENGINE_POSTFIX_HOOK (sd);

	/* process any events */
	if (sim_events_tick (sd))
	sim_events_process (sd);
	}
	}

	/* Main loop, for multiple cpus. */

	static void
	engine_run_n (SIM_DESC sd, int next_cpu_nr, int nr_cpus, int max_insns, int fast_p)
	{
	int i;
	/* Ensure that engine_fns is fully initialized, this silences a compiler
	warning when engine_fns is used below. */
	ENGINE_FN *engine_fns[MAX_NR_PROCESSORS] = {};

	SIM_ASSERT (nr_cpus <= MAX_NR_PROCESSORS);
	SIM_ASSERT (next_cpu_nr >= 0 && next_cpu_nr < nr_cpus);

	for (i = 0; i < nr_cpus; ++i)
	{
	SIM_CPU *cpu = STATE_CPU (sd, i);

	engine_fns[i] = fast_p ? CPU_FAST_ENGINE_FN (cpu) : CPU_FULL_ENGINE_FN (cpu);
	prime_cpu (cpu, max_insns);
	}

	while (1)
	{
	SIM_ENGINE_PREFIX_HOOK (sd);

	/* FIXME: proper cycling of all of them, blah blah blah. */
	while (next_cpu_nr < nr_cpus)
	{
	SIM_CPU *cpu = STATE_CPU (sd, next_cpu_nr);

	(* engine_fns[next_cpu_nr]) (cpu);
	++next_cpu_nr;
	}

	SIM_ENGINE_POSTFIX_HOOK (sd);

	/* process any events */
	if (sim_events_tick (sd))
	sim_events_process (sd);
	}
	}