genoutput.c

这是完整的gcc源代码

      predicates[opno] = XSTR (part, 1);
      constraints[opno] = XSTR (part, 2);
      if (XSTR (part, 2) != 0 && *XSTR (part, 2) != 0)
	{
	  op_n_alternatives[opno] = n_occurrences (',', XSTR (part, 2)) + 1;
	  have_constraints = 1;
	}
      address_p[opno] = this_address_p;
      return;
    }

  if (code == MATCH_OPERATOR)
    {
      int opno = XINT (part, 0);
      if (opno > max_opno)
	max_opno = opno;
      if (max_opno >= MAX_MAX_OPERANDS)
	error ("Too many operands (%d) in one instruction pattern.\n",
	       max_opno + 1);
      modes[opno] = GET_MODE (part);
      strict_low[opno] = 0;
      predicates[opno] = XSTR (part, 1);
      constraints[opno] = 0;
      address_p[opno] = 0;
      for (i = 0; i < XVECLEN (part, 2); i++)
	scan_operands (XVECEXP (part, 2, i), 0, 0);
      return;
    }

  if (code == MATCH_DUP)
    {
      ++num_dups;
      return;
    }

  if (code == ADDRESS)
    {
      scan_operands (XEXP (part, 0), 1, 0);
      return;
    }

  if (code == STRICT_LOW_PART)
    {
      scan_operands (XEXP (part, 0), 0, 1);
      return;
    }

  format_ptr = GET_RTX_FORMAT (GET_CODE (part));

  for (i = 0; i < GET_RTX_LENGTH (GET_CODE (part)); i++)
    switch (*format_ptr++)
      {
      case 'e':
	scan_operands (XEXP (part, i), 0, 0);
	break;
      case 'E':
	if (XVEC (part, i) != NULL)
	  for (j = 0; j < XVECLEN (part, i); j++)
	    scan_operands (XVECEXP (part, i, j), 0, 0);
	break;
      }
}

/* Look at a define_insn just read.  Assign its code number.
   Record on insn_data the template and the number of arguments.
   If the insn has a hairy output action, output a function for now.  */

void
gen_insn (insn)
     rtx insn;
{
  register struct data *d = (struct data *) xmalloc (sizeof (struct data));
  register int i;

  d->code_number = next_code_number++;
  if (XSTR (insn, 0)[0])
    d->name = XSTR (insn, 0);
  else
    d->name = 0;

  /* Build up the list in the same order as the insns are seen
     in the machine description.  */
  d->next = 0;
  if (end_of_insn_data)
    end_of_insn_data->next = d;
  else
    insn_data = d;

  end_of_insn_data = d;

  max_opno = -1;
  num_dups = 0;

  mybzero (constraints, sizeof constraints);
  mybzero (op_n_alternatives, sizeof op_n_alternatives);
  mybzero (predicates, sizeof predicates);
  mybzero (address_p, sizeof address_p);
  mybzero (modes, sizeof modes);
  mybzero (strict_low, sizeof strict_low);
  for (i = 0; i < XVECLEN (insn, 1); i++)
    scan_operands (XVECEXP (insn, 1, i), 0, 0);
  d->n_operands = max_opno + 1;
  d->n_dups = num_dups;
  mybcopy (constraints, d->constraints, sizeof constraints);
  mybcopy (op_n_alternatives, d->op_n_alternatives, sizeof op_n_alternatives);
  mybcopy (predicates, d->predicates, sizeof predicates);
  mybcopy (address_p, d->address_p, sizeof address_p);
  mybcopy (modes, d->modes, sizeof modes);
  mybcopy (strict_low, d->strict_low, sizeof strict_low);
  d->machine_info = XSTR (insn, 4);

  /* We need to consider only the instructions whose assembler code template
     starts with a *.  These are the ones where the template is really
     C code to run to decide on a template to use.
     So for all others just return now.  */

  if (XSTR (insn, 3)[0] != '*')
    {
      d->template = XSTR (insn, 3);
      d->outfun = 0;
      return;
    }

  d->template = 0;
  d->outfun = 1;

  printf ("\nstatic char *\n");
  printf ("output_%d (operands, insn)\n", d->code_number);
  printf ("     rtx *operands;\n");
  printf ("     rtx insn;\n");
  printf ("{\n");
  /* The following is done in a funny way to get around problems in
     VAX-11 "C" on VMS.  It is the equivalent of:
		printf ("%s\n", &(XSTR (insn, 3)[1])); */
  {
    register char *cp = &(XSTR (insn, 3)[1]);
    while (*cp) putchar (*cp++);
    putchar ('\n');
  }
  printf ("}\n");
}

/* Look at a define_peephole just read.  Assign its code number.
   Record on insn_data the template and the number of arguments.
   If the insn has a hairy output action, output it now.  */

void
gen_peephole (peep)
     rtx peep;
{
  register struct data *d = (struct data *) xmalloc (sizeof (struct data));
  register int i;

  d->code_number = next_code_number++;
  d->name = 0;

  /* Build up the list in the same order as the insns are seen
     in the machine description.  */
  d->next = 0;
  if (end_of_insn_data)
    end_of_insn_data->next = d;
  else
    insn_data = d;

  end_of_insn_data = d;

  max_opno = -1;
  mybzero (constraints, sizeof constraints);
  mybzero (op_n_alternatives, sizeof op_n_alternatives);

  /* Get the number of operands by scanning all the
     patterns of the peephole optimizer.
     But ignore all the rest of the information thus obtained.  */
  for (i = 0; i < XVECLEN (peep, 0); i++)
    scan_operands (XVECEXP (peep, 0, i), 0, 0);

  d->n_operands = max_opno + 1;
  d->n_dups = 0;
  mybcopy (constraints, d->constraints, sizeof constraints);
  mybcopy (op_n_alternatives, d->op_n_alternatives, sizeof op_n_alternatives);
  mybzero (d->predicates, sizeof predicates);
  mybzero (d->address_p, sizeof address_p);
  mybzero (d->modes, sizeof modes);
  mybzero (d->strict_low, sizeof strict_low);
  d->machine_info = XSTR (peep, 3);

  /* We need to consider only the instructions whose assembler code template
     starts with a *.  These are the ones where the template is really
     C code to run to decide on a template to use.
     So for all others just return now.  */

  if (XSTR (peep, 2)[0] != '*')
    {
      d->template = XSTR (peep, 2);
      d->outfun = 0;
      return;
    }

  d->template = 0;
  d->outfun = 1;

  printf ("\nstatic char *\n");
  printf ("output_%d (operands, insn)\n", d->code_number);
  printf ("     rtx *operands;\n");
  printf ("     rtx insn;\n");
  printf ("{\n");
  printf ("%s\n", &(XSTR (peep, 2)[1]));
  printf ("}\n");
}

/* Process a define_expand just read.  Assign its code number,
   only for the purposes of `insn_gen_function'.  */

void
gen_expand (insn)
     rtx insn;
{
  register struct data *d = (struct data *) xmalloc (sizeof (struct data));
  register int i;

  d->code_number = next_code_number++;
  if (XSTR (insn, 0)[0])
    d->name = XSTR (insn, 0);
  else
    d->name = 0;

  /* Build up the list in the same order as the insns are seen
     in the machine description.  */
  d->next = 0;
  if (end_of_insn_data)
    end_of_insn_data->next = d;
  else
    insn_data = d;

  end_of_insn_data = d;

  max_opno = -1;
  num_dups = 0;

  /* Scan the operands to get the specified predicates and modes,
     since expand_binop needs to know them.  */

  mybzero (predicates, sizeof predicates);
  mybzero (modes, sizeof modes);
  if (XVEC (insn, 1))
    for (i = 0; i < XVECLEN (insn, 1); i++)
      scan_operands (XVECEXP (insn, 1, i), 0, 0);
  d->n_operands = max_opno + 1;
  mybcopy (predicates, d->predicates, sizeof predicates);
  mybcopy (modes, d->modes, sizeof modes);

  mybzero (d->constraints, sizeof constraints);
  mybzero (d->op_n_alternatives, sizeof op_n_alternatives);
  mybzero (d->address_p, sizeof address_p);
  mybzero (d->strict_low, sizeof strict_low);

  d->n_dups = 0;
  d->template = 0;
  d->outfun = 0;
  d->machine_info = 0;
}

int
xmalloc (size)
{
  register int val = malloc (size);

  if (val == 0)
    fatal ("virtual memory exhausted");
  return val;
}

int
xrealloc (ptr, size)
     char *ptr;
     int size;
{
  int result = realloc (ptr, size);
  if (!result)
    fatal ("virtual memory exhausted");
  return result;
}

void
mybzero (b, length)
     register char *b;
     register int length;
{
  while (length-- > 0)
    *b++ = 0;
}

void
mybcopy (b1, b2, length)
     register char *b1;
     register char *b2;
     register int length;
{
  while (length-- > 0)
    *b2++ = *b1++;
}

void
fatal (s, a1, a2)
     char *s;
{
  fprintf (stderr, "genoutput: ");
  fprintf (stderr, s, a1, a2);
  fprintf (stderr, "\n");
  exit (FATAL_EXIT_CODE);
}

/* More 'friendly' abort that prints the line and file.
   config.h can #define abort fancy_abort if you like that sort of thing.  */

void
fancy_abort ()
{
  fatal ("Internal gcc abort.");
}

void
error (s, a1, a2)
     char *s;
{
  fprintf (stderr, "genoutput: ");
  fprintf (stderr, s, a1, a2);
  fprintf (stderr, "\n");
}

int
main (argc, argv)
     int argc;
     char **argv;
{
  rtx desc;
  FILE *infile;
  extern rtx read_rtx ();
  register int c;

  obstack_init (rtl_obstack);

  if (argc <= 1)
    fatal ("No input file name.");

  infile = fopen (argv[1], "r");
  if (infile == 0)
    {
      perror (argv[1]);
      exit (FATAL_EXIT_CODE);
    }

  init_rtl ();

  output_prologue ();
  next_code_number = 0;
  have_constraints = 0;

  /* Read the machine description.  */

  while (1)
    {
      c = read_skip_spaces (infile);
      if (c == EOF)
	break;
      ungetc (c, infile);

      desc = read_rtx (infile);
      if (GET_CODE (desc) == DEFINE_INSN)
	gen_insn (desc);
      if (GET_CODE (desc) == DEFINE_PEEPHOLE)
	gen_peephole (desc);
      if (GET_CODE (desc) == DEFINE_EXPAND)
	gen_expand (desc);
    }

  output_epilogue ();

  fflush (stdout);
  exit (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
}

int
n_occurrences (c, s)
     char c;
     char *s;
{
  int n = 0;
  while (*s)
    n += (*s++ == c);
  return n;
}