gen-idecode.c

这个是LINUX下的GDB调度工具的源码

    lf_putstr(file, "\n");

    lf_putstr(file, "\n");
    lf_putstr(file, "/* now add restart target as ready to run */\n");
    lf_putstr(file, "psim_set_halt_and_restart(system, &halt, &restart);\n");
    lf_putstr(file, "if (setjmp(restart)) {\n");
    lf_putstr(file, "  if (WITH_EVENTS) {\n");
    lf_putstr(file, "    /* when restart, cpu must have been last, clock next */\n");
    lf_putstr(file, "    if (event_queue_tick(events)) {\n");
    lf_putstr(file, "      event_queue_process(events);\n");
    lf_putstr(file, "    }\n");
    lf_putstr(file, "  }\n");
    lf_putstr(file, "}\n");

    lf_putstr(file, "\n");
    lf_putstr(file, "/* prime the main loop */\n");
    lf_putstr(file, "processor = processors[0];\n");
    lf_putstr(file, "cia = cpu_get_program_counter(processor);\n");

    lf_putstr(file, "\n");
    lf_putstr(file, "while (1) {\n");
    lf_indent(file, +2);

    if (!(code & generate_with_icache)) {
      lf_putstr(file, "instruction_word instruction =\n");
      lf_putstr(file, "  vm_instruction_map_read(cpu_instruction_map(processor), processor, cia);\n");
      lf_putstr(file, "\n");
      print_idecode_body(file, table, "cia =");;
    }

    if ((code & generate_with_icache)) {
      lf_putstr(file, "idecode_cache *cache_entry =\n");
      lf_putstr(file, "  cpu_icache_entry(processor, cia);\n");
      lf_putstr(file, "if (cache_entry->address == cia) {\n");
      lf_putstr(file, "  /* cache hit */\n");
      lf_putstr(file, "  idecode_semantic *const semantic = cache_entry->semantic;\n");
      lf_putstr(file, "  cia = semantic(processor, cache_entry, cia);\n");
      /* tail */
      if (can_stop) {
	lf_putstr(file, "if (keep_running != NULL && !*keep_running)\n");
	lf_putstr(file, "  cpu_halt(processor, cia, was_continuing, 0/*ignore*/);\n");
      }
      lf_putstr(file, "}\n");
      lf_putstr(file, "else {\n");
      lf_putstr(file, "  /* cache miss */\n");
      if (!(code & generate_with_semantic_icache)) {
	lf_indent(file, +2);
	lf_putstr(file, "idecode_semantic *semantic;\n");
	lf_indent(file, -2);
      }
      lf_putstr(file, "  instruction_word instruction =\n");
      lf_putstr(file, "    vm_instruction_map_read(cpu_instruction_map(processor), processor, cia);\n");
      lf_putstr(file, "  if (WITH_MON != 0)\n");
      lf_putstr(file, "    mon_event(mon_event_icache_miss, processor, cia);\n");
      if ((code & generate_with_semantic_icache)) {
	lf_putstr(file, "{\n");
	lf_indent(file, +2);
	print_idecode_body(file, table, "cia =");
	lf_indent(file, -2);
	lf_putstr(file, "}\n");
      }
      else {
	print_idecode_body(file, table, "semantic =");
	lf_putstr(file, "  cia = semantic(processor, cache_entry, cia);\n");
      }
      lf_putstr(file, "}\n");
    }

    /* events */
    lf_putstr(file, "\n");
    lf_putstr(file, "/* process any events */\n");
    lf_putstr(file, "if (WITH_EVENTS) {\n");
    lf_putstr(file, "  if (event_queue_tick(events)) {\n");
    lf_putstr(file, "    cpu_set_program_counter(processor, cia);\n");
    lf_putstr(file, "    event_queue_process(events);\n");
    lf_putstr(file, "    cia = cpu_get_program_counter(processor);\n");
    lf_putstr(file, "  }\n");
    lf_putstr(file, "}\n");

    /* tail */
    if (can_stop) {
      lf_putstr(file, "\n");
      lf_putstr(file, "/* abort if necessary */\n");
      lf_putstr(file, "if (keep_running != NULL && !*keep_running)\n");
      lf_putstr(file, "  cpu_halt(processor, cia, was_continuing, 0/*not important*/);\n");
    }

    lf_indent(file, -2);
    lf_putstr(file, "}\n");
  }
    
  if (generate_smp) {

    lf_putstr(file, "\n\
/* CASE 2: SMP (With or without ICACHE)\n\
\n\
   The complexity here comes from needing to correctly restart the\n\
   system when it is aborted.  In particular if cpu0 requests a\n\
   restart, the next cpu is still cpu1.  Cpu0 being restarted after\n\
   all the other CPU's and the event queue have been processed */");

    lf_putstr(file, "\n");

    lf_putstr(file, "\n");
    lf_putstr(file, "/* now establish the restart target */\n");
    lf_putstr(file, "psim_set_halt_and_restart(system, &halt, &restart);\n");
    lf_putstr(file, "if (setjmp(restart)) {\n");
    lf_putstr(file, "  current_cpu = psim_last_cpu(system);\n");
    lf_putstr(file, "  ASSERT(current_cpu >= 0 && current_cpu < nr_cpus);\n");
    lf_putstr(file, "}\n");
    lf_putstr(file, "else {\n");
    lf_putstr(file, "  current_cpu = last_cpu;\n");
    lf_putstr(file, "  ASSERT(current_cpu >= -1 && current_cpu < nr_cpus);\n");
    lf_putstr(file, "}\n");
    

    lf_putstr(file, "\n");
    lf_putstr(file, "while (1) {\n");
    lf_indent(file, +2);

    lf_putstr(file, "\n");
    lf_putstr(file, "if (WITH_EVENTS) {\n");
    lf_putstr(file, "  current_cpu += 1;\n");
    lf_putstr(file, "  if (current_cpu == nr_cpus) {\n");
    lf_putstr(file, "    if (event_queue_tick(events)) {\n");
    lf_putstr(file, "      event_queue_process(events);\n");
    lf_putstr(file, "    }\n");
    lf_putstr(file, "    current_cpu = 0;\n");
    lf_putstr(file, "  }\n");
    lf_putstr(file, "}\n");
    lf_putstr(file, "else {\n");
    lf_putstr(file, "  current_cpu = (current_cpu + 1) % nr_cpus;\n");
    lf_putstr(file, "}\n");

    lf_putstr(file, "\n");
    lf_putstr(file, "{\n");
    lf_indent(file, +2);
    lf_putstr(file, "cpu *processor = processors[current_cpu];\n");
    lf_putstr(file, "unsigned_word cia =\n");
    lf_putstr(file, "  cpu_get_program_counter(processor);\n");

    if (!(code & generate_with_icache)) {
      lf_putstr(file, "instruction_word instruction =\n");
      lf_putstr(file, "  vm_instruction_map_read(cpu_instruction_map(processor), processor, cia);\n");
      print_idecode_body(file, table, "cia =");
      if (can_stop) {
	lf_putstr(file, "if (keep_running != NULL && !*keep_running)\n");
	lf_putstr(file, "  cpu_halt(processor, cia, was_continuing, 0/*ignore*/);\n");
      }
      lf_putstr(file, "cpu_set_program_counter(processor, cia);\n");
    }

    if ((code & generate_with_icache)) {
      lf_putstr(file, "idecode_cache *cache_entry =\n");
      lf_putstr(file, "  cpu_icache_entry(processor, cia);\n");
      lf_putstr(file, "\n");
      lf_putstr(file, "if (cache_entry->address == cia) {\n");
      {
	lf_indent(file, +2);
	lf_putstr(file, "\n");
	lf_putstr(file, "/* cache hit */\n");
	lf_putstr(file, "idecode_semantic *semantic = cache_entry->semantic;\n");
	lf_putstr(file, "cia = semantic(processor, cache_entry, cia);\n");
	/* tail */
	if (can_stop) {
	  lf_putstr(file, "if (keep_running != NULL && !*keep_running)\n");
	  lf_putstr(file, "  cpu_halt(processor, cia, was_continuing, 0/*ignore-signal*/);\n");
	}
	lf_putstr(file, "cpu_set_program_counter(processor, cia);\n");
	lf_putstr(file, "\n");
	lf_indent(file, -2);
      }
      lf_putstr(file, "}\n");
      lf_putstr(file, "else {\n");
      {
	lf_indent(file, +2);
	lf_putstr(file, "\n");
	lf_putstr(file, "/* cache miss */\n");
	if (!(code & generate_with_semantic_icache)) {
	  lf_putstr(file, "idecode_semantic *semantic;\n");
	}
	lf_putstr(file, "instruction_word instruction =\n");
	lf_putstr(file, "  vm_instruction_map_read(cpu_instruction_map(processor), processor, cia);\n");
	lf_putstr(file, "if (WITH_MON != 0)\n");
	lf_putstr(file, "  mon_event(mon_event_icache_miss, processors[current_cpu], cia);\n");
	if ((code & generate_with_semantic_icache)) {
	  lf_putstr(file, "{\n");
	  lf_indent(file, +2);
	  print_idecode_body(file, table, "cia =");
	  lf_indent(file, -2);
	  lf_putstr(file, "}\n");
	}
	else {
	  print_idecode_body(file, table, "semantic = ");
	  lf_putstr(file, "cia = semantic(processor, cache_entry, cia);\n");
	}
	/* tail */
	if (can_stop) {
	  lf_putstr(file, "if (keep_running != NULL && !*keep_running)\n");
	  lf_putstr(file, "  cpu_halt(processor, cia, was_continuing, 0/*ignore-signal*/);\n");
	}
	lf_putstr(file, "cpu_set_program_counter(processor, cia);\n");
	lf_putstr(file, "\n");
	lf_indent(file, -2);
      }
      lf_putstr(file, "}\n");
    }

    /* close */
    lf_indent(file, -2);
    lf_putstr(file, "}\n");

    /* tail */
    lf_indent(file, -2);
    lf_putstr(file, "}\n");
  }


  lf_indent(file, -2);
  lf_putstr(file, "}\n");
}


/****************************************************************/

static void
print_jump(lf *file,
	   int is_tail)
{
  if (is_tail) {
    lf_putstr(file, "if (keep_running != NULL && !*keep_running)\n");
    lf_putstr(file, "  cpu_halt(processor, nia, was_continuing, 0/*na*/);\n");
  }
  
  if (!generate_smp) {
    lf_putstr(file, "if (WITH_EVENTS) {\n");
    lf_putstr(file, "  if (event_queue_tick(events)) {\n");
    lf_putstr(file, "    cpu_set_program_counter(processor, nia);\n");
    lf_putstr(file, "    event_queue_process(events);\n");
    lf_putstr(file, "    nia = cpu_get_program_counter(processor);\n");
    lf_putstr(file, "  }\n");
    lf_putstr(file, "}\n");
  }

  if (generate_smp) {
    if (is_tail)
      lf_putstr(file, "cpu_set_program_counter(processor, nia);\n");
    lf_putstr(file, "if (WITH_EVENTS) {\n");
    lf_putstr(file, "  current_cpu += 1;\n");
    lf_putstr(file, "  if (current_cpu >= nr_cpus) {\n");
    lf_putstr(file, "    if (event_queue_tick(events)) {\n");
    lf_putstr(file, "      event_queue_process(events);\n");
    lf_putstr(file, "    }\n");
    lf_putstr(file, "    current_cpu = 0;\n");
    lf_putstr(file, "  }\n");
    lf_putstr(file, "}\n");
    lf_putstr(file, "else {\n");
    lf_putstr(file, "  current_cpu = (current_cpu + 1) % nr_cpus;\n");
    lf_putstr(file, "}\n");
    lf_putstr(file, "processor = processors[current_cpu];\n");
    lf_putstr(file, "nia = cpu_get_program_counter(processor);\n");
  }

  if ((code & generate_with_icache)) {
    lf_putstr(file, "cache_entry = cpu_icache_entry(processor, nia);\n");
    lf_putstr(file, "if (cache_entry->address == nia) {\n");
    lf_putstr(file, "  /* cache hit */\n");
    lf_putstr(file, "  goto *cache_entry->semantic;\n");
    lf_putstr(file, "}\n");
    if (is_tail) {
      lf_putstr(file, "goto cache_miss;\n");
    }
  }

  if (!(code & generate_with_icache) && is_tail) {
    lf_printf(file, "goto idecode;\n");
  }

}





static void
print_jump_insn(lf *file,
		insn *instruction,
		insn_bits *expanded_bits,
		opcode_field *opcodes,
		cache_table *cache_rules)
{

  /* what we are for the moment */
  lf_printf(file, "\n");
  print_my_defines(file, expanded_bits, instruction->file_entry);

  /* output the icache entry */
  if ((code & generate_with_icache)) {
    lf_printf(file, "\n");
    lf_indent(file, -1);
    print_function_name(file,
			instruction->file_entry->fields[insn_name],
			expanded_bits,
			function_name_prefix_icache);
    lf_printf(file, ":\n");
    lf_indent(file, +1);
    lf_printf(file, "{\n");
    lf_indent(file, +2);
    lf_putstr(file, "const unsigned_word cia = nia;\n");
    print_itrace(file, instruction->file_entry, 1/*putting-value-in-cache*/);
    print_idecode_validate(file, instruction, opcodes);
    lf_printf(file, "\n");
    lf_printf(file, "{\n");
    lf_indent(file, +2);
    print_icache_body(file,
		      instruction,
		      expanded_bits,
		      cache_rules,
		      0, /*use_defines*/
		      put_values_in_icache);
    lf_printf(file, "cache_entry->address = nia;\n");
    lf_printf(file, "cache_entry->semantic = &&");
    print_function_name(file,
			instruction->file_entry->fields[insn_name],
			expanded_bits,
			function_name_prefix_semantics);
    lf_printf(file, ";\n");
    if ((code & generate_with_semantic_icache)) {
      print_semantic_body(file,
			  instruction,
			  expanded_bits,
			  opcodes);
      print_jump(file, 1/*is-tail*/);
    }
    else {
      lf_printf(file, "/* goto ");
      print_function_name(file,
			  instruction->file_entry->fields[insn_name],
			  expanded_bits,
			  function_name_prefix_semantics);
      lf_printf(file, "; */\n");
    }
    lf_indent(file, -2);
    lf_putstr(file, "}\n");
    lf_indent(file, -2);
    lf_printf(file, "}\n");
  }

  /* print the semantics */
  lf_printf(file, "\n");
  lf_indent(file, -1);
  print_function_name(file,
		      instruction->file_entry->fields[insn_name],
		      expanded_bits,
		      function_name_prefix_semantics);
  lf_printf(file, ":\n");
  lf_indent(file, +1);
  lf_printf(file, "{\n");
  lf_indent(file, +2);
  lf_putstr(file, "const unsigned_word cia = nia;\n");
  print_icache_body(file,
		    instruction,
		    expanded_bits,
		    cache_rules,
		    ((code & generate_with_direct_access)
		     ? define_variables
		     : declare_variables),
		    ((code & generate_with_icache)
		     ? get_values_from_icache
		     : do_not_use_icache));
  print_semantic_body(file,
		      instruction,
		      expanded_bits,
		      opcodes);
  if (code & generate_with_direct_access)
    print_icache_body(file,
		      instruction,
		      expanded_bits,
		      cache_rules,
		      undef_variables,
		      ((code & generate_with_icache)
		       ? get_values_from_icache
		       : do_not_use_icache));
  print_jump(file, 1/*is tail*/);
  lf_indent(file, -2);
  lf_printf(file, "}\n");
}