/* Generate code from to output assembler insns as recognized from rtl.
   Copyright (C) 1987, 1988, 1992, 1994, 1995, 1997, 1998, 1999, 2000
   Free Software Foundation, Inc.

This file is part of GNU CC.

GNU CC 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 2, or (at your option)
any later version.

GNU CC 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 GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */


/* This program reads the machine description for the compiler target machine
   and produces a file containing these things:

   1. An array of `struct insn_data', which is indexed by insn code number,
   which contains:

     a. `name' is the name for that pattern.  Nameless patterns are
     given a name.

     b. `output' hold either the output template, an array of output
     templates, or an output function.

     c. `genfun' is the function to generate a body for that pattern,
     given operands as arguments.

     d. `n_operands' is the number of distinct operands in the pattern
     for that insn,

     e. `n_dups' is the number of match_dup's that appear in the insn's
     pattern.  This says how many elements of `recog_data.dup_loc' are
     significant after an insn has been recognized.

     f. `n_alternatives' is the number of alternatives in the constraints
     of each pattern.

     g. `output_format' tells what type of thing `output' is.

     h. `operand' is the base of an array of operand data for the insn.

   2. An array of `struct insn_operand data', used by `operand' above.

     a. `predicate', an int-valued function, is the match_operand predicate
     for this operand.

     b. `constraint' is the constraint for this operand.  This exists
     only if register constraints appear in match_operand rtx's.

     c. `address_p' indicates that the operand appears within ADDRESS
     rtx's.  This exists only if there are *no* register constraints
     in the match_operand rtx's.

     d. `mode' is the machine mode that that operand is supposed to have.

     e. `strict_low', is nonzero for operands contained in a STRICT_LOW_PART.

     f. `eliminable', is nonzero for operands that are matched normally by
     MATCH_OPERAND; it is zero for operands that should not be changed during
     register elimination such as MATCH_OPERATORs.

  The code number of an insn is simply its position in the machine
  description; code numbers are assigned sequentially to entries in
  the description, starting with code number 0.

  Thus, the following entry in the machine description

    (define_insn "clrdf"
      [(set (match_operand:DF 0 "general_operand" "")
	    (const_int 0))]
      ""
      "clrd %0")

  assuming it is the 25th entry present, would cause
  insn_data[24].template to be "clrd %0", and
  insn_data[24].n_operands to be 1.  */

#include "hconfig.h"
#include "system.h"
#include "rtl.h"
#include "errors.h"
#include "gensupport.h"

/* No instruction can have more operands than this.  Sorry for this
   arbitrary limit, but what machine will have an instruction with
   this many operands?  */

#define MAX_MAX_OPERANDS 40

static int n_occurrences		PARAMS ((int, const char *));
static const char *strip_whitespace	PARAMS ((const char *));

/* insns in the machine description are assigned sequential code numbers
   that are used by insn-recog.c (produced by genrecog) to communicate
   to insn-output.c (produced by this program).  */

static int next_code_number;

/* This counts all definitions in the md file,
   for the sake of error messages.  */

static int next_index_number;

/* This counts all operands used in the md file.  The first is null.  */

static int next_operand_number = 1;

/* Record in this chain all information about the operands we will output.  */

struct operand_data
{
  struct operand_data *next;
  int index;
  const char *predicate;
  const char *constraint;
  enum machine_mode mode;
  unsigned char n_alternatives;
  char address_p;
  char strict_low;
  char eliminable;
  char seen;
};

/* Begin with a null operand at index 0.  */

static struct operand_data null_operand =
{
  0, 0, "", "", VOIDmode, 0, 0, 0, 0, 0
};

static struct operand_data *odata = &null_operand;
static struct operand_data **odata_end = &null_operand.next;

/* Must match the constants in recog.h.  */

#define INSN_OUTPUT_FORMAT_NONE         0       /* abort */
#define INSN_OUTPUT_FORMAT_SINGLE       1       /* const char * */
#define INSN_OUTPUT_FORMAT_MULTI        2       /* const char * const * */
#define INSN_OUTPUT_FORMAT_FUNCTION     3       /* const char * (*)(...) */

/* Record in this chain all information that we will output,
   associated with the code number of the insn.  */

struct data
{
  struct data *next;
  const char *name;
  const char *template;
  int code_number;
  int index_number;
  int lineno;
  int n_operands;		/* Number of operands this insn recognizes */
  int n_dups;			/* Number times match_dup appears in pattern */
  int n_alternatives;		/* Number of alternatives in each constraint */
  int operand_number;		/* Operand index in the big array.  */
  int output_format;		/* INSN_OUTPUT_FORMAT_*.  */
  struct operand_data operand[MAX_MAX_OPERANDS];
};

/* This variable points to the first link in the insn chain.  */

static struct data *idata, **idata_end = &idata;

static void output_prologue PARAMS ((void));
static void output_predicate_decls PARAMS ((void));
static void output_operand_data PARAMS ((void));
static void output_insn_data PARAMS ((void));
static void output_get_insn_name PARAMS ((void));
static void scan_operands PARAMS ((struct data *, rtx, int, int));
static int compare_operands PARAMS ((struct operand_data *,
				   struct operand_data *));
static void place_operands PARAMS ((struct data *));
static void process_template PARAMS ((struct data *, const char *));
static void validate_insn_alternatives PARAMS ((struct data *));
static void validate_insn_operands PARAMS ((struct data *));
static void gen_insn PARAMS ((rtx, int));
static void gen_peephole PARAMS ((rtx, int));
static void gen_expand PARAMS ((rtx, int));
static void gen_split PARAMS ((rtx, int));

const char *
get_insn_name (index)
     int index;
{
  static char buf[100];

  struct data *i, *last_named = NULL;
  for (i = idata; i ; i = i->next)
    {
      if (i->index_number == index)
	return i->name;
      if (i->name)
	last_named = i;
    }

  if (last_named)
    sprintf(buf, "%s+%d", last_named->name, index - last_named->index_number);
  else
    sprintf(buf, "insn %d", index);

  return buf;
}

static void
output_prologue ()
{
  printf ("/* Generated automatically by the program `genoutput'\n\
   from the machine description file `md'.  */\n\n");

  printf ("#include \"config.h\"\n");
  printf ("#include \"system.h\"\n");
  printf ("#include \"flags.h\"\n");
  printf ("#include \"ggc.h\"\n");
  printf ("#include \"rtl.h\"\n");
  printf ("#include \"tm_p.h\"\n");
  printf ("#include \"function.h\"\n");
  printf ("#include \"regs.h\"\n");
  printf ("#include \"hard-reg-set.h\"\n");
  printf ("#include \"real.h\"\n");
  printf ("#include \"insn-config.h\"\n\n");
  printf ("#include \"conditions.h\"\n");
  printf ("#include \"insn-attr.h\"\n\n");
  printf ("#include \"recog.h\"\n\n");
  printf ("#include \"toplev.h\"\n");
  printf ("#include \"output.h\"\n");
}


/* We need to define all predicates used.  Keep a list of those we
   have defined so far.  There normally aren't very many predicates
   used, so a linked list should be fast enough.  */
struct predicate { const char *name; struct predicate *next; };

static void
output_predicate_decls ()
{
  struct predicate *predicates = 0;
  register struct operand_data *d;
  struct predicate *p, *next;

  for (d = odata; d; d = d->next)
    if (d->predicate && d->predicate[0])
      {
	for (p = predicates; p; p = p->next)
	  if (strcmp (p->name, d->predicate) == 0)
	    break;

	if (p == 0)
	  {
	    printf ("extern int %s PARAMS ((rtx, enum machine_mode));\n",
		    d->predicate);
	    p = (struct predicate *) xmalloc (sizeof (struct predicate));
	    p->name = d->predicate;
	    p->next = predicates;
	    predicates = p;
	  }
      }

  printf ("\n\n");
  for (p = predicates; p; p = next)
    {
      next = p->next;
      free (p);
    }
}

static void
output_operand_data ()
{
  register struct operand_data *d;

  printf ("\nstatic const struct insn_operand_data operand_data[] = \n{\n");

  for (d = odata; d; d = d->next)
    {
      printf ("  {\n");

      printf ("    %s,\n",
	      d->predicate && d->predicate[0] ? d->predicate : "0");

      printf ("    \"%s\",\n", d->constraint ? d->constraint : "");

      printf ("    %smode,\n", GET_MODE_NAME (d->mode));

      printf ("    %d,\n", d->strict_low);

      printf ("    %d\n", d->eliminable);

      printf("  },\n");
    }
  printf("};\n\n\n");
}

static void
output_insn_data ()
{
  register struct data *d;
  int name_offset = 0;
  int next_name_offset;
  const char * last_name = 0;
  const char * next_name = 0;
  register struct data *n;

  for (n = idata, next_name_offset = 1; n; n = n->next, next_name_offset++)
    if (n->name)
      {
	next_name = n->name;
	break;
      }

  printf ("\nconst struct insn_data insn_data[] = \n{\n");

  for (d = idata; d; d = d->next)
    {
      printf ("  {\n");

      if (d->name)
	{
	  printf ("    \"%s\",\n", d->name);
	  name_offset = 0;
	  last_name = d->name;
	  next_name = 0;
	  for (n = d->next, next_name_offset = 1; n;
	       n = n->next, next_name_offset++)
	    {
	      if (n->name)
		{
		  next_name = n->name;
		  break;
		}
	    }
	}
      else
	{
	  name_offset++;
	  if (next_name && (last_name == 0
			    || name_offset > next_name_offset / 2))
	    printf ("    \"%s-%d\",\n", next_name,
		    next_name_offset - name_offset);
	  else
	    printf ("    \"%s+%d\",\n", last_name, name_offset);
	}

      switch (d->output_format)
	{
	case INSN_OUTPUT_FORMAT_NONE:
	  printf ("    0,\n");
	  break;
	case INSN_OUTPUT_FORMAT_SINGLE:
	  {
	    const char *p = d->template;
	    char prev = 0;
	    
	    printf ("    \"");
	    while (*p)
	      {
		if (*p == '\n' && prev != '\\')
		  printf ("\\n\\\n");
		else
		  putchar (*p);
		prev = *p;
		++p;
	      }
	    printf ("\",\n");
	  }
	  break;
	case INSN_OUTPUT_FORMAT_MULTI:
	case INSN_OUTPUT_FORMAT_FUNCTION:
	  printf ("    (const PTR) output_%d,\n", d->code_number);
	  break;
	default:
	  abort ();
	}

      if (d->name && d->name[0] != '*')
	printf ("    (insn_gen_fn) gen_%s,\n", d->name);
      else
	printf ("    0,\n");

      printf ("    &operand_data[%d],\n", d->operand_number);
      printf ("    %d,\n", d->n_operands);
      printf ("    %d,\n", d->n_dups);
      printf ("    %d,\n", d->n_alternatives);
      printf ("    %d\n", d->output_format);

      printf("  },\n");
    }
  printf ("};\n\n\n");
}

static void
output_get_insn_name ()
{
  printf ("const char *\n");
  printf ("get_insn_name (code)\n");
  printf ("     int code;\n");
  printf ("{\n");
  printf ("  return insn_data[code].name;\n");
  printf ("}\n");
}


/* Stores in max_opno the largest operand number present in `part', if
   that is larger than the previous value of max_opno, and the rest of
   the operand data into `d->operand[i]'.

   THIS_ADDRESS_P is nonzero if the containing rtx was an ADDRESS.
   THIS_STRICT_LOW is nonzero if the containing rtx was a STRICT_LOW_PART.  */

static int max_opno;
static int num_dups;

static void
scan_operands (d, part, this_address_p, this_strict_low)
     struct data *d;
     rtx part;
     int this_address_p;
     int this_strict_low;
{
  register int i, j;
  register const char *format_ptr;
  int opno;

  if (part == 0)
    return;

  switch (GET_CODE (part))
    {
    case MATCH_OPERAND:
      opno = XINT (part, 0);
      if (opno > max_opno)
	max_opno = opno;
      if (max_opno >= MAX_MAX_OPERANDS)
	{
	  message_with_line (d->lineno,
			     "maximum number of operands exceeded");
	  have_error = 1;
	  return;
	}
      if (d->operand[opno].seen)
	{
	  message_with_line (d->lineno,
			     "repeated operand number %d\n", opno);
	  have_error = 1;
	}

      d->operand[opno].seen = 1;
      d->operand[opno].mode = GET_MODE (part);
      d->operand[opno].strict_low = this_strict_low;
      d->operand[opno].predicate = XSTR (part, 1);
      d->operand[opno].constraint = strip_whitespace (XSTR (part, 2));
      d->operand[opno].n_alternatives
	= n_occurrences (',', d->operand[opno].constraint) + 1;
      d->operand[opno].address_p = this_address_p;
      d->operand[opno].eliminable = 1;
      return;

    case MATCH_SCRATCH:
      opno = XINT (part, 0);
      if (opno > max_opno)
	max_opno = opno;
      if (max_opno >= MAX_MAX_OPERANDS)
	{
	  message_with_line (d->lineno,
			     "maximum number of operands exceeded");
	  have_error = 1;
	  return;
	}
      if (d->operand[opno].seen)
	{
	  message_with_line (d->lineno,
			     "repeated operand number %d\n", opno);
	  have_error = 1;
	}

      d->operand[opno].seen = 1;
      d->operand[opno].mode = GET_MODE (part);
      d->operand[opno].strict_low = 0;
      d->operand[opno].predicate = "scratch_operand";
      d->operand[opno].constraint = strip_whitespace (XSTR (part, 1));
      d->operand[opno].n_alternatives
	= n_occurrences (',', d->operand[opno].constraint) + 1;
      d->operand[opno].address_p = 0;
      d->operand[opno].eliminable = 0;
      return;

    case MATCH_OPERATOR:
    case MATCH_PARALLEL:
      opno = XINT (part, 0);
      if (opno > max_opno)
	max_opno = opno;
      if (max_opno >= MAX_MAX_OPERANDS)
	{
	  message_with_line (d->lineno,
			     "maximum number of operands exceeded");
	  have_error = 1;
	  return;
	}
      if (d->operand[opno].seen)
	{
	  message_with_line (d->lineno,
			     "repeated operand number %d\n", opno);
	  have_error = 1;
	}

      d->operand[opno].seen = 1;
      d->operand[opno].mode = GET_MODE (part);
      d->operand[opno].strict_low = 0;
      d->operand[opno].predicate = XSTR (part, 1);
      d->operand[opno].constraint = 0;
      d->operand[opno].address_p = 0;
      d->operand[opno].eliminable = 0;
      for (i = 0; i < XVECLEN (part, 2); i++)
	scan_operands (d, XVECEXP (part, 2, i), 0, 0);
      return;

    case MATCH_DUP:
    case MATCH_OP_DUP:
    case MATCH_PAR_DUP:
      ++num_dups;
      return;

    case ADDRESS:
      scan_operands (d, XEXP (part, 0), 1, 0);
      return;

    case STRICT_LOW_PART:
      scan_operands (d, XEXP (part, 0), 0, 1);
      return;
      
    default:
      break;
    }

  format_ptr = GET_RTX_FORMAT (GET_CODE (part));

  for (i = 0; i < GET_RTX_LENGTH (GET_CODE (part)); i++)
    switch (*format_ptr++)
      {
      case 'e':
      case 'u':
	scan_operands (d, XEXP (part, i), 0, 0);
	break;
      case 'E':
	if (XVEC (part, i) != NULL)
	  for (j = 0; j < XVECLEN (part, i); j++)
	    scan_operands (d, XVECEXP (part, i, j), 0, 0);
	break;
      }
}

/* Compare two operands for content equality.  */

static int
compare_operands (d0, d1)
     struct operand_data *d0, *d1;
{
  const char *p0, *p1;

  p0 = d0->predicate;
  if (!p0)
    p0 = "";
  p1 = d1->predicate;
  if (!p1)
    p1 = "";
  if (strcmp (p0, p1) != 0)
    return 0;

  p0 = d0->constraint;
  if (!p0)
    p0 = "";
  p1 = d1->constraint;
  if (!p1)
    p1 = "";
  if (strcmp (p0, p1) != 0)
    return 0;

  if (d0->mode != d1->mode)
    return 0;

  if (d0->strict_low != d1->strict_low)
    return 0;

  if (d0->eliminable != d1->eliminable)
    return 0;

  return 1;
}

/* Scan the list of operands we've already committed to output and either
   find a subsequence that is the same, or allocate a new one at the end.  */

static void
place_operands (d)
     struct data *d;
{
  struct operand_data *od, *od2;
  int i;

  if (d->n_operands == 0)
    {
      d->operand_number = 0;
      return;
    }

  /* Brute force substring search.  */
  for (od = odata, i = 0; od; od = od->next, i = 0)
    if (compare_operands (od, &d->operand[0]))
      {
	od2 = od->next;
	i = 1;
	while (1)
	  {
	    if (i == d->n_operands)
	      goto full_match;
	    if (od2 == NULL)
	      goto partial_match;
	    if (! compare_operands (od2, &d->operand[i]))
	      break;
	    ++i, od2 = od2->next;
	  }
      }

  /* Either partial match at the end of the list, or no match.  In either
     case, we tack on what operands are remaining to the end of the list.  */
 partial_match:
  d->operand_number = next_operand_number - i;
  for (; i < d->n_operands; ++i)
    {
      od2 = &d->operand[i];
      *odata_end = od2;
      odata_end = &od2->next;
      od2->index = next_operand_number++;
    }
  *odata_end = NULL;
  return;

 full_match:
  d->operand_number = od->index;
  return;
}


/* Process an assembler template from a define_insn or a define_peephole.
   It is either the assembler code template, a list of assembler code
   templates, or C code to generate the assembler code template.  */

static void
process_template (d, template)
    struct data *d;
    const char *template;
{
  register const char *cp;
  register int i;

  /* Templates starting with * contain straight code to be run.  */
  if (template[0] == '*')
    {
      d->template = 0;
      d->output_format = INSN_OUTPUT_FORMAT_FUNCTION;

      printf ("\nstatic const char *output_%d PARAMS ((rtx *, rtx));\n",
	      d->code_number);
      puts ("\nstatic const char *");
      printf ("output_%d (operands, insn)\n", d->code_number);
      puts ("     rtx *operands ATTRIBUTE_UNUSED;");
      puts ("     rtx insn ATTRIBUTE_UNUSED;");
      puts ("{");

      puts (template + 1);
      puts ("}");
    }

  /* If the assembler code template starts with a @ it is a newline-separated
     list of assembler code templates, one for each alternative.  */
  else if (template[0] == '@')
    {
      d->template = 0;
      d->output_format = INSN_OUTPUT_FORMAT_MULTI;

      printf ("\nstatic const char * const output_%d[] = {\n", d->code_number);

      for (i = 0, cp = &template[1]; *cp; )
	{
	  while (*cp == '\n' || *cp == ' ' || *cp== '\t')
	    cp++;

	  printf ("  \"");
	  while (*cp != '\n' && *cp != '\0')
	    {
	      putchar (*cp);
	      cp++;
	    }

	  printf ("\",\n");
	  i++;
	}
      if (i == 1)
	message_with_line (d->lineno,
			   "'@' is redundant for output template with single alternative");
      if (i != d->n_alternatives)
	{
	  message_with_line (d->lineno,
			     "Wrong number of alternatives in the output template");
	  have_error = 1;
	}

      printf ("};\n");
    }
  else
    {
      d->template = template;
      d->output_format = INSN_OUTPUT_FORMAT_SINGLE;
    }
}

/* Check insn D for consistency in number of constraint alternatives.  */

static void
validate_insn_alternatives (d)
     struct data *d;
{
  register int n = 0, start;

  /* Make sure all the operands have the same number of alternatives
     in their constraints.  Let N be that number.  */
  for (start = 0; start < d->n_operands; start++)
    if (d->operand[start].n_alternatives > 0)
      {
	if (n == 0)
	  n = d->operand[start].n_alternatives;
	else if (n != d->operand[start].n_alternatives)
	  {
	    message_with_line (d->lineno,
			       "wrong number of alternatives in operand %d",
			       start);
	    have_error = 1;
	  }
      }

  /* Record the insn's overall number of alternatives.  */
  d->n_alternatives = n;
}

/* Verify that there are no gaps in operand numbers for INSNs.  */

static void
validate_insn_operands (d)
     struct data *d;
{
  int i;

  for (i = 0; i < d->n_operands; ++i)
    if (d->operand[i].seen == 0)
      {
	message_with_line (d->lineno, "missing operand %d", i);
	have_error = 1;
      }
}

/* Look at a define_insn just read.  Assign its code number.  Record
   on idata the template and the number of arguments.  If the insn has
   a hairy output action, output a function for now.  */

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

  d->code_number = next_code_number;
  d->index_number = next_index_number;
  d->lineno = lineno;
  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;
  *idata_end = d;
  idata_end = &d->next;

  max_opno = -1;
  num_dups = 0;
  memset (d->operand, 0, sizeof (d->operand));

  for (i = 0; i < XVECLEN (insn, 1); i++)
    scan_operands (d, XVECEXP (insn, 1, i), 0, 0);

  d->n_operands = max_opno + 1;
  d->n_dups = num_dups;

  validate_insn_operands (d);
  validate_insn_alternatives (d);
  place_operands (d);
  process_template (d, XSTR (insn, 3));
}

/* Look at a define_peephole just read.  Assign its code number.
   Record on idata the template and the number of arguments.
   If the insn has a hairy output action, output it now.  */

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

  d->code_number = next_code_number;
  d->index_number = next_index_number;
  d->lineno = lineno;
  d->name = 0;

  /* Build up the list in the same order as the insns are seen
     in the machine description.  */
  d->next = 0;
  *idata_end = d;
  idata_end = &d->next;

  max_opno = -1;
  num_dups = 0;
  memset (d->operand, 0, sizeof (d->operand));

  /* 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 (d, XVECEXP (peep, 0, i), 0, 0);

  d->n_operands = max_opno + 1;
  d->n_dups = 0;

  validate_insn_alternatives (d);
  place_operands (d);
  process_template (d, XSTR (peep, 2));
}

/* Process a define_expand just read.  Assign its code number,
   only for the purposes of `insn_gen_function'.  */

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

  d->code_number = next_code_number;
  d->index_number = next_index_number;
  d->lineno = lineno;
  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;
  *idata_end = d;
  idata_end = &d->next;

  max_opno = -1;
  num_dups = 0;
  memset (d->operand, 0, sizeof (d->operand));

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

  if (XVEC (insn, 1))
    for (i = 0; i < XVECLEN (insn, 1); i++)
      scan_operands (d, XVECEXP (insn, 1, i), 0, 0);

  d->n_operands = max_opno + 1;
  d->n_dups = num_dups;
  d->template = 0;
  d->output_format = INSN_OUTPUT_FORMAT_NONE;

  validate_insn_alternatives (d);
  place_operands (d);
}

/* Process a define_split just read.  Assign its code number,
   only for reasons of consistency and to simplify genrecog.  */

static void
gen_split (split, lineno)
     rtx split;
     int lineno;
{
  register struct data *d = (struct data *) xmalloc (sizeof (struct data));
  register int i;

  d->code_number = next_code_number;
  d->index_number = next_index_number;
  d->lineno = lineno;
  d->name = 0;

  /* Build up the list in the same order as the insns are seen
     in the machine description.  */
  d->next = 0;
  *idata_end = d;
  idata_end = &d->next;

  max_opno = -1;
  num_dups = 0;
  memset (d->operand, 0, sizeof (d->operand));

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

  d->n_operands = max_opno + 1;
  d->n_dups = 0;
  d->n_alternatives = 0;
  d->template = 0;
  d->output_format = INSN_OUTPUT_FORMAT_NONE;

  place_operands (d);
}

extern int main PARAMS ((int, char **));

int
main (argc, argv)
     int argc;
     char **argv;
{
  rtx desc;

  progname = "genoutput";

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

  if (init_md_reader (argv[1]) != SUCCESS_EXIT_CODE)
    return (FATAL_EXIT_CODE);

  output_prologue ();
  next_code_number = 0;
  next_index_number = 0;

  /* Read the machine description.  */

  while (1)
    {
      int line_no;

      desc = read_md_rtx (&line_no, &next_code_number);
      if (desc == NULL)
	break;

      if (GET_CODE (desc) == DEFINE_INSN)
	gen_insn (desc, line_no);
      if (GET_CODE (desc) == DEFINE_PEEPHOLE)
	gen_peephole (desc, line_no);
      if (GET_CODE (desc) == DEFINE_EXPAND)
	gen_expand (desc, line_no);
      if (GET_CODE (desc) == DEFINE_SPLIT
 	  || GET_CODE (desc) == DEFINE_PEEPHOLE2)
	gen_split (desc, line_no);
      next_index_number++;
    }

  printf("\n\n");
  output_predicate_decls ();
  output_operand_data ();
  output_insn_data ();
  output_get_insn_name ();

  fflush (stdout);
  return (ferror (stdout) != 0 || have_error
	? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
}

/* Return the number of occurrences of character C in string S or
   -1 if S is the null string.  */

static int
n_occurrences (c, s)
     int c;
     const char *s;
{
  int n = 0;

  if (s == 0 || *s == '\0')
    return -1;

  while (*s)
    n += (*s++ == c);

  return n;
}

/* Remove whitespace in `s' by moving up characters until the end.
   Return a new string.  */

static const char *
strip_whitespace (s)
     const char *s;
{
  char *p, *q;
  char ch;

  if (s == 0)
    return 0;

  p = q = xmalloc (strlen (s) + 1);
  while ((ch = *s++) != '\0')
    if (! ISSPACE (ch))
      *p++ = ch;

  *p = '\0';
  return q;
}