gen-idecode.c

这个是LINUX下的GDB调度工具的源码

	  }
	print_function_name (file,
			     entry->insns->insn->name,
			     entry->insns->insn->format_name,
			     NULL,
			     entry->expanded_bits,
			     (options.gen.icache
			      ? function_name_prefix_icache
			      : function_name_prefix_semantics));
	if (options.gen.code == generate_calls)
	  {
	    lf_printf (file, " (");
	    print_semantic_function_actual (file,
					    entry->insns->semantic->
					    nr_prefetched_words);
	    lf_printf (file, ")");
	  }
	lf_printf (file, ";\n");
      }
    else if (entry->opcode_rule->gen == switch_gen
	     || entry->opcode_rule->gen == goto_switch_gen
	     || entry->opcode_rule->gen == padded_switch_gen)
      {
	/* switch calling switch */
	lf_printf (file, "{\n");
	lf_indent (file, +2);
	print_idecode_ifetch (file, entry->parent->nr_prefetched_words,
			      entry->nr_prefetched_words);
	print_idecode_switch (file, entry, result);
	lf_indent (file, -2);
	lf_printf (file, "}\n");
      }
    else
      {
	/* switch looking up a table */
	lf_printf (file, "{\n");
	lf_indent (file, +2);
	print_idecode_ifetch (file, entry->parent->nr_prefetched_words,
			      entry->nr_prefetched_words);
	print_idecode_table (file, entry, result);
	lf_indent (file, -2);
	lf_printf (file, "}\n");
      }
    if (entry->parent->opcode->is_boolean
	|| entry->parent->opcode_rule->gen == switch_gen
	|| entry->parent->opcode_rule->gen == padded_switch_gen)
      {
	lf_printf (file, "break;\n");
      }
    else if (entry->parent->opcode_rule->gen == goto_switch_gen)
      {
	print_goto_switch_break (file, entry);
      }
    else
      {
	ERROR ("bad switch");
      }
  }
  lf_indent (file, -4);
  lf_printf (file, "  }\n");
}


static void
print_idecode_switch_illegal (lf *file, const char *result)
{
  lf_indent (file, +2);
  print_idecode_invalid (file, result, invalid_illegal);
  lf_printf (file, "break;\n");
  lf_indent (file, -2);
}

static void
print_idecode_switch_end (lf *file, gen_entry *table, int depth, void *data)
{
  const char *result = data;
  ASSERT (depth == 0);
  ASSERT (table->opcode_rule->gen == switch_gen
	  || table->opcode_rule->gen == goto_switch_gen
	  || table->opcode_rule->gen == padded_switch_gen);
  ASSERT (table->opcode);

  if (table->opcode->is_boolean)
    {
      lf_printf (file, "}\n");
      lf_indent (file, -2);
    }
  else if (table->opcode_rule->gen == switch_gen
	   || table->opcode_rule->gen == padded_switch_gen)
    {
      lf_printf (file, "default:\n");
      lf_indent (file, +2);
      if (table->nr_entries == table->opcode->nr_opcodes)
	{
	  print_sim_engine_abort (file,
				  "Internal error - bad switch generated");
	  lf_printf (file, "%sNULL_CIA;\n", result);
	  lf_printf (file, "break;\n");
	}
      else
	{
	  print_idecode_switch_illegal (file, result);
	}
      lf_indent (file, -2);
      lf_printf (file, "}\n");
      lf_indent (file, -2);
    }
  else if (table->opcode_rule->gen == goto_switch_gen)
    {
      lf_printf (file, "illegal_");
      lf_print_table_name (file, table);
      lf_printf (file, ":\n");
      print_idecode_invalid (file, result, invalid_illegal);
      lf_printf (file, "break_");
      lf_print_table_name (file, table);
      lf_printf (file, ":;\n");
      if (table->parent != NULL
	  && (table->parent->opcode_rule->gen == switch_gen
	      || table->parent->opcode_rule->gen == goto_switch_gen
	      || table->parent->opcode_rule->gen == padded_switch_gen))
	{
	  lf_indent (file, -2);
	  lf_printf (file, "}\n");
	}
    }
  else
    {
      ERROR ("bad switch");
    }
}


void
print_idecode_switch (lf *file, gen_entry *table, const char *result)
{
  gen_entry_traverse_tree (file, table,
			   0,
			   print_idecode_switch_start,
			   print_idecode_switch_leaf,
			   print_idecode_switch_end, (void *) result);
}


static void
print_idecode_switch_function_header (lf *file,
				      gen_entry *table,
				      int is_function_definition,
				      int nr_prefetched_words)
{
  lf_printf (file, "\n");
  if (options.gen.code == generate_calls)
    {
      lf_printf (file, "static ");
      if (options.gen.icache)
	{
	  lf_printf (file, "idecode_semantic *");
	}
      else
	{
	  lf_printf (file, "unsigned_word");
	}
      if (is_function_definition)
	{
	  lf_printf (file, "\n");
	}
      else
	{
	  lf_printf (file, " ");
	}
      lf_print_table_name (file, table);
      lf_printf (file, "\n(");
      print_icache_function_formal (file, nr_prefetched_words);
      lf_printf (file, ")");
      if (!is_function_definition)
	{
	  lf_printf (file, ";");
	}
      lf_printf (file, "\n");
    }
  if (options.gen.code == generate_jumps && is_function_definition)
    {
      lf_indent (file, -1);
      lf_print_table_name (file, table);
      lf_printf (file, ":\n");
      lf_indent (file, +1);
    }
}


static void
idecode_declare_if_switch (lf *file, gen_entry *table, int depth, void *data)
{
  if ((table->opcode_rule->gen == switch_gen || table->opcode_rule->gen == goto_switch_gen || table->opcode_rule->gen == padded_switch_gen) &&table->parent != NULL	/* don't declare the top one yet */
      && table->parent->opcode_rule->gen == array_gen)
    {
      print_idecode_switch_function_header (file,
					    table,
					    0 /*isnt function definition */ ,
					    0);
    }
}


static void
idecode_expand_if_switch (lf *file, gen_entry *table, int depth, void *data)
{
  if ((table->opcode_rule->gen == switch_gen || table->opcode_rule->gen == goto_switch_gen || table->opcode_rule->gen == padded_switch_gen) &&table->parent != NULL	/* don't expand the top one yet */
      && table->parent->opcode_rule->gen == array_gen)
    {
      print_idecode_switch_function_header (file,
					    table,
					    1 /*is function definition */ ,
					    0);
      if (options.gen.code == generate_calls)
	{
	  lf_printf (file, "{\n");
	  lf_indent (file, +2);
	}
      print_idecode_switch (file, table, "return");
      if (options.gen.code == generate_calls)
	{
	  lf_indent (file, -2);
	  lf_printf (file, "}\n");
	}
    }
}


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


void
print_idecode_lookups (lf *file, gen_entry *table, cache_entry *cache_rules)
{
  int depth;

  /* output switch function declarations where needed by tables */
  gen_entry_traverse_tree (file, table, 1, idecode_declare_if_switch,	/* START */
			   NULL, NULL, NULL);

  /* output tables where needed */
  for (depth = gen_entry_depth (table); depth > 0; depth--)
    {
      gen_entry_traverse_tree (file, table,
			       1 - depth,
			       print_idecode_table_start,
			       print_idecode_table_leaf,
			       print_idecode_table_end, NULL);
    }

  /* output switch functions where needed */
  gen_entry_traverse_tree (file, table, 1, idecode_expand_if_switch,	/* START */
			   NULL, NULL, NULL);
}


void
print_idecode_body (lf *file, gen_entry *table, const char *result)
{
  if (table->opcode_rule->gen == switch_gen
      || table->opcode_rule->gen == goto_switch_gen
      || table->opcode_rule->gen == padded_switch_gen)
    {
      print_idecode_switch (file, table, result);
    }
  else
    {
      print_idecode_table (file, table, result);
    }
}


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

#if 0
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(cpu, nia, was_continuing, 0/*na*/);\n");
    }

  if (!options.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(cpu, nia);\n");
      lf_putstr (file, "    event_queue_process(events);\n");
      lf_putstr (file, "    nia = cpu_get_program_counter(cpu);\n");
      lf_putstr (file, "  }\n");
      lf_putstr (file, "}\n");
    }

  if (options.generate_smp)
    {
      if (is_tail)
	{
	  lf_putstr (file, "cpu_set_program_counter(cpu, 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, "cpu = cpus[current_cpu];\n");
      lf_putstr (file, "nia = cpu_get_program_counter(cpu);\n");
    }

  if (options.gen.icache)
    {
      lf_putstr (file, "cache_entry = cpu_icache_entry(cpu, 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 (!options.gen.icache && is_tail)
    {
      lf_printf (file, "goto idecode;\n");
    }

}
#endif



#if 0
static void
print_jump_insn (lf *file,
		 insn_entry * instruction,
		 insn_bits * expanded_bits,
		 opcode_field *opcodes, cache_entry *cache_rules)
{

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

  /* output the icache entry */
  if (options.gen.icache)
    {
      lf_printf (file, "\n");
      lf_indent (file, -1);
      print_function_name (file,
			   instruction->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, 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->name,
			   expanded_bits, function_name_prefix_semantics);
      lf_printf (file, ";\n");
      if (options.gen.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->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->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,
		     (options.gen.direct_access
		      ? define_variables
		      : declare_variables),
		     (options.gen.icache
		      ? get_values_from_icache : do_not_use_icache));
  print_semantic_body (file, instruction, expanded_bits, opcodes);
  if (options.gen.direct_access)
    print_icache_body (file,
		       instruction,
		       expanded_bits,
		       cache_rules,
		       undef_variables,
		       (options.gen.icache
			? get_values_from_icache : do_not_use_icache));
  print_jump (file, 1 /*is tail */ );
  lf_indent (file, -2);
  lf_printf (file, "}\n");
}
#endif


#if 0
static void
print_jump_definition (lf *file,