gen-idecode.c

这个是LINUX下的GDB调度工具的源码

		       gen_entry *entry,
		       insn_entry * insn, int depth, void *data)
{
  cache_entry *cache_rules = (cache_entry *) data;
  if (options.generate_expanded_instructions)
    {
      ASSERT (entry->nr_insns == 1
	      && entry->opcode == NULL
	      && entry->parent != NULL && entry->parent->opcode != NULL);
      ASSERT (entry->nr_insns == 1
	      && entry->opcode == NULL
	      && entry->parent != NULL
	      && entry->parent->opcode != NULL
	      && entry->parent->opcode_rule != NULL);
      print_jump_insn (file,
		       entry->insns->words[0]->insn,
		       entry->expanded_bits, entry->opcode, cache_rules);
    }
  else
    {
      print_jump_insn (file,
		       instruction->words[0]->insn, NULL, NULL, cache_rules);
    }
}
#endif

#if 0
static void
print_jump_internal_function (lf *file,
			      gen_entry *table,
			      function_entry * function, void *data)
{
  if (function->is_internal)
    {
      lf_printf (file, "\n");
      lf_print__line_ref (file, function->line);
      lf_indent (file, -1);
      print_function_name (file,
			   function->name,
			   NULL,
			   (options.gen.icache
			    ? function_name_prefix_icache
			    : function_name_prefix_semantics));
      lf_printf (file, ":\n");
      lf_indent (file, +1);
      lf_printf (file, "{\n");
      lf_indent (file, +2);
      lf_printf (file, "const unsigned_word cia = nia;\n");
      table_print_code (file, function->code);
      lf_print__internal_ref (file);
      print_sim_engine_abort (file, "Internal function must longjump");
      lf_indent (file, -2);
      lf_printf (file, "}\n");
    }
}
#endif



#if 0
static void
print_jump_until_stop_body (lf *file,
			    insn_table *table, cache_table * cache_rules)
{
  lf_printf (file, "{\n");
  lf_indent (file, +2);
  lf_putstr (file, "jmp_buf halt;\n");
  lf_putstr (file, "jmp_buf restart;\n");
  lf_putstr (file, "sim_cpu *cpu = NULL;\n");
  lf_putstr (file, "unsigned_word nia = -1;\n");
  lf_putstr (file, "instruction_word instruction = 0;\n");
  if ((code & generate_with_icache))
    {
      lf_putstr (file, "idecode_cache *cache_entry = NULL;\n");
    }
  if (generate_smp)
    {
      lf_putstr (file, "int current_cpu = -1;\n");
    }

  /* all the switches and tables - they know about jumping */
  print_idecode_lookups (file, table, cache_rules);

  /* start the simulation up */
  if ((code & generate_with_icache))
    {
      lf_putstr (file, "\n");
      lf_putstr (file, "{\n");
      lf_putstr (file, "  int cpu_nr;\n");
      lf_putstr (file, "  for (cpu_nr = 0; cpu_nr < nr_cpus; cpu_nr++)\n");
      lf_putstr (file, "    cpu_flush_icache(cpus[cpu_nr]);\n");
      lf_putstr (file, "}\n");
    }

  lf_putstr (file, "\n");
  lf_putstr (file, "psim_set_halt_and_restart(system, &halt, &restart);\n");

  lf_putstr (file, "\n");
  lf_putstr (file, "if (setjmp(halt))\n");
  lf_putstr (file, "  return;\n");

  lf_putstr (file, "\n");
  lf_putstr (file, "setjmp(restart);\n");

  lf_putstr (file, "\n");
  if (!generate_smp)
    {
      lf_putstr (file, "cpu = cpus[0];\n");
      lf_putstr (file, "nia = cpu_get_program_counter(cpu);\n");
    }
  else
    {
      lf_putstr (file, "current_cpu = psim_last_cpu(system);\n");
    }

  if (!(code & generate_with_icache))
    {
      lf_printf (file, "\n");
      lf_indent (file, -1);
      lf_printf (file, "idecode:\n");
      lf_indent (file, +1);
    }

  print_jump (file, 0 /*is_tail */ );

  if ((code & generate_with_icache))
    {
      lf_indent (file, -1);
      lf_printf (file, "cache_miss:\n");
      lf_indent (file, +1);
    }

  lf_putstr (file, "instruction\n");
  lf_putstr (file, "  = vm_instruction_map_read(cpu_instruction_map(cpu),\n");
  lf_putstr (file, "                            cpu, nia);\n");
  print_idecode_body (file, table, "/*IGORE*/");

  /* print out a table of all the internals functions */
  insn_table_traverse_function (table,
				file, NULL, print_jump_internal_function);

  /* print out a table of all the instructions */
  if (generate_expanded_instructions)
    insn_table_traverse_tree (table, file, cache_rules, 1, NULL,	/* start */
			      print_jump_definition,	/* leaf */
			      NULL,	/* end */
			      NULL);	/* padding */
  else
    insn_table_traverse_insn (table,
			      file, cache_rules, print_jump_definition);
  lf_indent (file, -2);
  lf_printf (file, "}\n");
}
#endif

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



/* Output code to do any final checks on the decoded instruction.
   This includes things like verifying any on decoded fields have the
   correct value and checking that (for floating point) floating point
   hardware isn't disabled */

void
print_idecode_validate (lf *file,
			insn_entry * instruction, insn_opcodes *opcode_paths)
{
  /* Validate: unchecked instruction fields

     If any constant fields in the instruction were not checked by the
     idecode tables, output code to check that they have the correct
     value here */
  {
    int nr_checks = 0;
    int word_nr;
    lf_printf (file, "\n");
    lf_indent_suppress (file);
    lf_printf (file, "#if defined (WITH_RESERVED_BITS)\n");
    lf_printf (file, "/* validate: ");
    print_insn_words (file, instruction);
    lf_printf (file, " */\n");
    for (word_nr = 0; word_nr < instruction->nr_words; word_nr++)
      {
	insn_uint check_mask = 0;
	insn_uint check_val = 0;
	insn_word_entry *word = instruction->word[word_nr];
	int bit_nr;

	/* form check_mask/check_val containing what needs to be checked
	   in the instruction */
	for (bit_nr = 0; bit_nr < options.insn_bit_size; bit_nr++)
	  {
	    insn_bit_entry *bit = word->bit[bit_nr];
	    insn_field_entry *field = bit->field;

	    /* Make space for the next bit */
	    check_mask <<= 1;
	    check_val <<= 1;

	    /* Only need to validate constant (and reserved)
	       bits. Skip any others */
	    if (field->type != insn_field_int
		&& field->type != insn_field_reserved)
	      continue;

	    /* Look through the list of opcode paths that lead to this
	       instruction.  See if any have failed to check the
	       relevant bit */
	    if (opcode_paths != NULL)
	      {
		insn_opcodes *entry;
		for (entry = opcode_paths; entry != NULL; entry = entry->next)
		  {
		    opcode_field *opcode;
		    for (opcode = entry->opcode;
			 opcode != NULL; opcode = opcode->parent)
		      {
			if (opcode->word_nr == word_nr
			    && opcode->first <= bit_nr
			    && opcode->last >= bit_nr)
			  /* we've decoded on this bit */
			  break;
		      }
		    if (opcode == NULL)
		      /* the bit wasn't decoded on */
		      break;
		  }
		if (entry == NULL)
		  /* all the opcode paths decoded on BIT_NR, no need
		     to check it */
		  continue;
	      }

	    check_mask |= 1;
	    check_val |= bit->value;
	  }

	/* if any bits not checked by opcode tables, output code to check them */
	if (check_mask)
	  {
	    if (nr_checks == 0)
	      {
		lf_printf (file, "if (WITH_RESERVED_BITS)\n");
		lf_printf (file, "  {\n");
		lf_indent (file, +4);
	      }
	    nr_checks++;
	    if (options.insn_bit_size > 32)
	      {
		lf_printf (file, "if ((instruction_%d\n", word_nr);
		lf_printf (file, "     & UNSIGNED64 (0x%08lx%08lx))\n",
			   (unsigned long) (check_mask >> 32),
			   (unsigned long) (check_mask));
		lf_printf (file, "    != UNSIGNED64 (0x%08lx%08lx))\n",
			   (unsigned long) (check_val >> 32),
			   (unsigned long) (check_val));
	      }
	    else
	      {
		lf_printf (file,
			   "if ((instruction_%d & 0x%08lx) != 0x%08lx)\n",
			   word_nr, (unsigned long) (check_mask),
			   (unsigned long) (check_val));
	      }
	    lf_indent (file, +2);
	    print_idecode_invalid (file, "return", invalid_illegal);
	    lf_indent (file, -2);
	  }
      }
    if (nr_checks > 0)
      {
	lf_indent (file, -4);
	lf_printf (file, "  }\n");
      }
    lf_indent_suppress (file);
    lf_printf (file, "#endif\n");
  }

  /* Validate: Floating Point hardware

     If the simulator is being built with out floating point hardware
     (different to it being disabled in the MSR) then floating point
     instructions are invalid */
  {
    if (filter_is_member (instruction->flags, "f"))
      {
	lf_printf (file, "\n");
	lf_indent_suppress (file);
	lf_printf (file, "#if defined(CURRENT_FLOATING_POINT)\n");
	lf_printf (file, "/* Validate: FP hardware exists */\n");
	lf_printf (file,
		   "if (CURRENT_FLOATING_POINT != HARD_FLOATING_POINT) {\n");
	lf_indent (file, +2);
	print_idecode_invalid (file, "return", invalid_illegal);
	lf_indent (file, -2);
	lf_printf (file, "}\n");
	lf_indent_suppress (file);
	lf_printf (file, "#endif\n");
      }
  }

  /* Validate: Floating Point available

     If floating point is not available, we enter a floating point
     unavailable interrupt into the cache instead of the instruction
     proper.

     The PowerPC spec requires a CSI after MSR[FP] is changed and when
     ever a CSI occures we flush the instruction cache. */

  {
    if (filter_is_member (instruction->flags, "f"))
      {
	lf_printf (file, "\n");
	lf_indent_suppress (file);
	lf_printf (file, "#if defined(IS_FP_AVAILABLE)\n");
	lf_printf (file, "/* Validate: FP available according to cpu */\n");
	lf_printf (file, "if (!IS_FP_AVAILABLE) {\n");
	lf_indent (file, +2);
	print_idecode_invalid (file, "return", invalid_fp_unavailable);
	lf_indent (file, -2);
	lf_printf (file, "}\n");
	lf_indent_suppress (file);
	lf_printf (file, "#endif\n");
      }
  }

  /* Validate: Validate Instruction in correct slot

     Some architectures place restrictions on the slot that an
     instruction can be issued in */

  {
    if (filter_is_member (instruction->options, "s")
	|| options.gen.slot_verification)
      {
	lf_printf (file, "\n");
	lf_indent_suppress (file);
	lf_printf (file, "#if defined(IS_WRONG_SLOT)\n");
	lf_printf (file,
		   "/* Validate: Instruction issued in correct slot */\n");
	lf_printf (file, "if (IS_WRONG_SLOT) {\n");
	lf_indent (file, +2);
	print_idecode_invalid (file, "return", invalid_wrong_slot);
	lf_indent (file, -2);
	lf_printf (file, "}\n");
	lf_indent_suppress (file);
	lf_printf (file, "#endif\n");
      }
  }

}


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


void
print_idecode_issue_function_header (lf *file,
				     const char *processor,
				     function_decl_type decl_type,
				     int nr_prefetched_words)
{
  int indent;
  lf_printf (file, "\n");
  switch (decl_type)
    {
    case is_function_declaration:
      lf_print__function_type_function (file, print_semantic_function_type,
					"INLINE_IDECODE", " ");
      break;
    case is_function_definition:
      lf_print__function_type_function (file, print_semantic_function_type,
					"INLINE_IDECODE", "\n");
      break;
    case is_function_variable:
      print_semantic_function_type (file);
      lf_printf (file, " (*");
      break;
    }
  indent = print_function_name (file,
				"issue",
				NULL,
				processor,
				NULL, function_name_prefix_idecode);
  switch (decl_type)
    {
    case is_function_definition:
      indent += lf_printf (file, " (");
      break;
    case is_function_declaration:
      lf_putstr (file, "\n(");
      indent = 1;
      break;
    case is_function_variable:
      lf_putstr (file, ")\n(");
      indent = 1;
      break;
    }
  lf_indent (file, +indent);
  print_semantic_function_formal (file, nr_prefetched_words);
  lf_putstr (file, ")");
  lf_indent (file, -indent);
  switch (decl_type)
    {
    case is_function_definition:
      lf_printf (file, "\n");
      break;
    case is_function_declaration:
    case is_function_variable:
      lf_putstr (file, ";\n");
      break;
    }
}



void
print_idecode_globals (lf *file)
{
  lf_printf (file, "enum {\n");
  lf_printf (file, "  /* greater or equal to zero => table */\n");
  lf_printf (file, "  function_entry = -1,\n");
  lf_printf (file, "  boolean_entry = -2,\n");
  lf_printf (file, "};\n");
  lf_printf (file, "\n");
  lf_printf (file, "typedef struct _idecode_table_entry {\n");
  lf_printf (file, "  int shift;\n");
  lf_printf (file, "  unsigned%d mask;\n", options.insn_bit_size);
  lf_printf (file, "  unsigned%d value;\n", options.insn_bit_size);
  lf_printf (file, "  void *function_or_table;\n");
  lf_printf (file, "} idecode_table_entry;\n");
}