path: root/contrib/gcc/genoutput.c

/* Generate code from to output assembler insns as recognized from rtl.
   Copyright (C) 1987, 88, 92, 94-95, 97-98, 1999 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 strings `insn_template' which is indexed by insn code number
   and contains the template for output of that insn,

   2. An array of functions `insn_outfun' which, indexed by the insn code
   number, gives the function that returns a template to use for output of
   that insn.  This is used only in the cases where the template is not
   constant.  These cases are specified by a * or @ at the beginning of the
   template string in the machine description.  They are identified for the
   sake of other parts of the compiler by a zero element in `insn_template'.
  
   3. An array of functions `insn_gen_function' which, indexed
   by insn code number, gives the function to generate a body
   for that pattern, given operands as arguments.

   4. An array of strings `insn_name' which, indexed by insn code number,
   gives the name for that pattern.  Nameless patterns are given a name.

   5. An array of ints `insn_n_operands' which is indexed by insn code number
   and contains the number of distinct operands in the pattern for that insn,

   6. An array of ints `insn_n_dups' which is indexed by insn code number
   and contains the number of match_dup's that appear in the insn's pattern.
   This says how many elements of `recog_dup_loc' are significant
   after an insn has been recognized.

   7. An array of arrays of operand constraint strings,
   `insn_operand_constraint',
   indexed first by insn code number and second by operand number,
   containing the constraint for that operand.

   This array is generated only if register constraints appear in 
   match_operand rtx's.

   8. An array of arrays of chars which indicate which operands of
   which insn patterns appear within ADDRESS rtx's.  This array is
   called `insn_operand_address_p' and is generated only if there
   are *no* register constraints in the match_operand rtx's.

   9. An array of arrays of machine modes, `insn_operand_mode',
   indexed first by insn code number and second by operand number,
   containing the machine mode that that operand is supposed to have.
   Also `insn_operand_strict_low', which is nonzero for operands
   contained in a STRICT_LOW_PART.

   10. An array of arrays of int-valued functions, `insn_operand_predicate',
   indexed first by insn code number and second by operand number,
   containing the match_operand predicate for this operand.

   11. An array of ints, `insn_n_alternatives', that gives the number
   of alternatives in the constraints of each pattern.

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_template[24] to be "clrd %0", and insn_n_operands[24] to be 1.
It would not make an case in output_insn_hairy because the template
given in the entry is a constant (it does not start with `*').  */

#include "hconfig.h"
#include "system.h"
#include "rtl.h"
#include "obstack.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 struct obstack obstack;
struct obstack *rtl_obstack = &obstack;

#define obstack_chunk_alloc xmalloc
#define obstack_chunk_free free

void fatal PVPROTO ((const char *, ...))
  ATTRIBUTE_PRINTF_1 ATTRIBUTE_NORETURN;
void fancy_abort PROTO((void)) ATTRIBUTE_NORETURN;
static void error PVPROTO ((const char *, ...)) ATTRIBUTE_PRINTF_1;
static int n_occurrences PROTO((int, char *));

/* Define this so we can link with print-rtl.o to get debug_rtx function.  */
char **insn_name_ptr = 0;

/* 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;

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

struct data
{
  int code_number;
  int index_number;
  char *name;
  char *template;		/* string such as "movl %1,%0" */
  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 */
  struct data *next;
  char *constraints[MAX_MAX_OPERANDS];
  /* Number of alternatives in constraints of operand N.  */
  int op_n_alternatives[MAX_MAX_OPERANDS];
  char *predicates[MAX_MAX_OPERANDS];
  char address_p[MAX_MAX_OPERANDS];
  enum machine_mode modes[MAX_MAX_OPERANDS];
  char strict_low[MAX_MAX_OPERANDS];
  char outfun;			/* Nonzero means this has an output function */
};

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

struct data *insn_data;

/* Pointer to the last link in the chain, so new elements
   can be added at the end.  */

struct data *end_of_insn_data;

/* Nonzero if any match_operand has a constraint string;
   implies that REGISTER_CONSTRAINTS will be defined
   for this machine description.  */

int have_constraints;

/* Nonzero if some error has occurred.  We will make all errors fatal, but
   might as well continue until we see all of them.  */

static int have_error;

static char * name_for_index PROTO((int));
static void output_prologue PROTO((void));
static void output_epilogue PROTO((void));
static void scan_operands PROTO((rtx, int, int));
static void process_template PROTO((struct data *, char *));
static void validate_insn_alternatives PROTO((struct data *));
static void gen_insn PROTO((rtx));
static void gen_peephole PROTO((rtx));
static void gen_expand PROTO((rtx));
static void gen_split PROTO((rtx));
static int n_occurrences PROTO((int, char *));

static char *
name_for_index (index)
     int index;
{
  static char buf[100];

  struct data *i, *last_named = NULL;
  for (i = insn_data; 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 \"rtl.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-flags.h\"\n");
  printf ("#include \"insn-attr.h\"\n\n");
  printf ("#include \"insn-codes.h\"\n\n");
  printf ("#include \"recog.h\"\n\n");

  printf ("#include \"output.h\"\n");
}

static void
output_epilogue ()
{
  register struct data *d;

  printf ("\nconst char * const insn_template[] =\n  {\n");
  for (d = insn_data; d; d = d->next)
    {
      if (d->template)
	printf ("    \"%s\",\n", d->template);
      else
	printf ("    0,\n");
    }
  printf ("  };\n");

  printf ("\nconst char *(*const insn_outfun[])() =\n  {\n");
  for (d = insn_data; d; d = d->next)
    {
      if (d->outfun)
	printf ("    output_%d,\n", d->code_number);
      else
	printf ("    0,\n");
    }
  printf ("  };\n");

  printf ("\nrtx (*const insn_gen_function[]) () =\n  {\n");
  for (d = insn_data; d; d = d->next)
    {
      if (d->name && d->name[0] != '*')
	printf ("    gen_%s,\n", d->name);
      else
	printf ("    0,\n");
    }
  printf ("  };\n");

  printf ("\nconst char *insn_name[] =\n  {\n");
  {
    int offset = 0;
    int next;
    char * last_name = 0;
    char * next_name = 0;
    register struct data *n;

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

    for (d = insn_data; d; d = d->next)
      {
	if (d->name)
	  {
	    printf ("    \"%s\",\n", d->name);
	    offset = 0;
	    last_name = d->name;
	    next_name = 0;
	    for (n = d->next, next = 1; n; n = n->next, next++)
	      if (n->name)
		{
		  next_name = n->name;
		  break;
		}
	  }
	else
	  {
	    offset++;
	    if (next_name && (last_name == 0 || offset > next / 2))
	      printf ("    \"%s-%d\",\n", next_name, next - offset);
	    else
	      printf ("    \"%s+%d\",\n", last_name, offset);
	  }
      }
  }
  printf ("  };\n");
  printf ("const char **insn_name_ptr = insn_name;\n");

  printf ("\nconst int insn_n_operands[] =\n  {\n");
  for (d = insn_data; d; d = d->next)
    printf ("    %d,\n", d->n_operands);
  printf ("  };\n");

  printf ("\nconst int insn_n_dups[] =\n  {\n");
  for (d = insn_data; d; d = d->next)
    printf ("    %d,\n", d->n_dups);
  printf ("  };\n");

  if (have_constraints)
    {
      printf ("\nconst char *const insn_operand_constraint[][MAX_RECOG_OPERANDS] =\n  {\n");
      for (d = insn_data; d; d = d->next)
	{
	  register int i;
	  printf ("    {");
	  for (i = 0; i < d->n_operands; i++)
	    {
	      if (d->constraints[i] == 0)
		printf (" \"\",");
	      else
		printf (" \"%s\",", d->constraints[i]);
	    }
	  if (d->n_operands == 0)
	    printf (" 0");
	  printf (" },\n");
	}
      printf ("  };\n");
    }
  else
    {
      printf ("\nconst char insn_operand_address_p[][MAX_RECOG_OPERANDS] =\n  {\n");
      for (d = insn_data; d; d = d->next)
	{
	  register int i;
	  printf ("    {");
	  for (i = 0; i < d->n_operands; i++)
	    printf (" %d,", d->address_p[i]);
	  if (d->n_operands == 0)
	    printf (" 0");
	  printf (" },\n");
	}
      printf ("  };\n");
    }

  printf ("\nconst enum machine_mode insn_operand_mode[][MAX_RECOG_OPERANDS] =\n  {\n");
  for (d = insn_data; d; d = d->next)
    {
      register int i;
      printf ("    {");
      for (i = 0; i < d->n_operands; i++)
	printf (" %smode,", GET_MODE_NAME (d->modes[i]));
      if (d->n_operands == 0)
	printf (" VOIDmode");
      printf (" },\n");
    }
  printf ("  };\n");

  printf ("\nconst char insn_operand_strict_low[][MAX_RECOG_OPERANDS] =\n  {\n");
  for (d = insn_data; d; d = d->next)
    {
      register int i;
      printf ("    {");
      for (i = 0; i < d->n_operands; i++)
	printf (" %d,", d->strict_low[i]);
      if (d->n_operands == 0)
	printf (" 0");
      printf (" },\n");
    }
  printf ("  };\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 { char *name; struct predicate *next; } *predicates = 0;
    struct predicate *p;
    int i;

    printf ("\n");
    for (d = insn_data; d; d = d->next)
      for (i = 0; i < d->n_operands; i++)
	if (d->predicates[i] && d->predicates[i][0])
	  {
	    for (p = predicates; p; p = p->next)
	      if (! strcmp (p->name, d->predicates[i]))
		break;

	    if (p == 0)
	      {
		printf ("extern int %s ();\n", d->predicates[i]);
		p = (struct predicate *) alloca (sizeof (struct predicate));
		p->name = d->predicates[i];
		p->next = predicates;
		predicates = p;
	      }
	  }
    
    printf ("\nint (*const insn_operand_predicate[][MAX_RECOG_OPERANDS])() =\n  {\n");
    for (d = insn_data; d; d = d->next)
      {
	printf ("    {");
	for (i = 0; i < d->n_operands; i++)
	  printf (" %s,", ((d->predicates[i] && d->predicates[i][0])
			   ? d->predicates[i] : "0"));
	if (d->n_operands == 0)
	  printf (" 0");
	printf (" },\n");
      }
    printf ("  };\n");
  }

  printf ("\nconst int insn_n_alternatives[] =\n  {\n");
  for (d = insn_data; d; d = d->next)
    printf ("    %d,\n", d->n_alternatives);
  printf("  };\n");
}

/* scan_operands (X) stores in max_opno the largest operand
   number present in X, if that is larger than the previous
   value of max_opno.  It stores all the constraints in `constraints'
   and all the machine modes in `modes'.

   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 char *constraints[MAX_MAX_OPERANDS];
static int op_n_alternatives[MAX_MAX_OPERANDS];
static const char *predicates[MAX_MAX_OPERANDS];
static char address_p[MAX_MAX_OPERANDS];
static enum machine_mode modes[MAX_MAX_OPERANDS];
static char strict_low[MAX_MAX_OPERANDS];
static char seen[MAX_MAX_OPERANDS];

static void
scan_operands (part, this_address_p, this_strict_low)
     rtx part;
     int this_address_p;
     int this_strict_low;
{
  register int i, j;
  register 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)
	{
	  error ("Too many operands (%d) in definition %s.\n",
		 max_opno + 1, name_for_index (next_index_number));
	  return;
	}
      if (seen[opno])
	error ("Definition %s specified operand number %d more than once.\n",
	       name_for_index (next_index_number), opno);
      seen[opno] = 1;
      modes[opno] = GET_MODE (part);
      strict_low[opno] = this_strict_low;
      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;

    case MATCH_SCRATCH:
      opno = XINT (part, 0);
      if (opno > max_opno)
	max_opno = opno;
      if (max_opno >= MAX_MAX_OPERANDS)
	{
	  error ("Too many operands (%d) in definition %s.\n",
		 max_opno + 1, name_for_index (next_index_number));
	  return;
	}
      if (seen[opno])
	error ("Definition %s specified operand number %d more than once.\n",
	       name_for_index (next_index_number), opno);
      seen[opno] = 1;
      modes[opno] = GET_MODE (part);
      strict_low[opno] = 0;
      predicates[opno] = "scratch_operand";
      constraints[opno] = XSTR (part, 1);
      if (XSTR (part, 1) != 0 && *XSTR (part, 1) != 0)
	{
	  op_n_alternatives[opno] = n_occurrences (',', XSTR (part, 1)) + 1;
	  have_constraints = 1;
	}
      address_p[opno] = 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)
	{
	  error ("Too many operands (%d) in definition %s.\n",
		 max_opno + 1, name_for_index (next_index_number));
	  return;
	}
      if (seen[opno])
	error ("Definition %s specified operand number %d more than once.\n",
	       name_for_index (next_index_number), opno);
      seen[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;

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

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

    case STRICT_LOW_PART:
      scan_operands (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 (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;
      }
}

/* 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;
    char *template;
{
  register char *cp;
  register int i;

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

  if (template[0] != '*' && template[0] != '@')
    {
      d->template = template;
      d->outfun = 0;
      return;
    }

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

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

  /* If the assembler code template starts with a @ it is a newline-separated
     list of assembler code templates, one for each alternative.  So produce
     a routine to select the correct one.  */

  if (template[0] == '@')
    {

      printf ("  static const char *const strings_%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++;
	}

      printf ("  };\n");
      printf ("  return strings_%d[which_alternative];\n", d->code_number);

      if (i != d->n_alternatives)
	fatal ("Insn pattern %d has %d alternatives but %d assembler choices",
	       d->index_number, d->n_alternatives, i);

    }
  else
    {
       /* 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", &template[1])); */
      cp = &template[1];
      while (*cp)
	{
	  putchar (*cp);
	  cp++;
	}
      putchar ('\n');
    }

  printf ("}\n");
}

/* 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->op_n_alternatives[start] > 0)
      {
	if (n == 0)
	  n = d->op_n_alternatives[start];
	else if (n != d->op_n_alternatives[start])
	  error ("wrong number of alternatives in operand %d of insn %s",
		 start, name_for_index (d->index_number));
      }
  /* Record the insn's overall number of alternatives.  */
  d->n_alternatives = n;
}

/* 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.  */

static 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++;
  d->index_number = next_index_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;

  memset (constraints, 0, sizeof constraints);
  memset (op_n_alternatives, 0, sizeof op_n_alternatives);
  memset (predicates, 0, sizeof predicates);
  memset (address_p, 0, sizeof address_p);
  memset (modes, 0, sizeof modes);
  memset (strict_low, 0, sizeof strict_low);
  memset (seen, 0, sizeof seen);

  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;

  memcpy (d->constraints, constraints, sizeof constraints);
  memcpy (d->op_n_alternatives, op_n_alternatives, sizeof op_n_alternatives);
  memcpy (d->predicates, predicates, sizeof predicates);
  memcpy (d->address_p, address_p, sizeof address_p);
  memcpy (d->modes, modes, sizeof modes);
  memcpy (d->strict_low, strict_low, sizeof strict_low);

  validate_insn_alternatives (d);
  process_template (d, XSTR (insn, 3));
}

/* 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.  */

static 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->index_number = next_index_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;
  memset (constraints, 0, sizeof constraints);
  memset (op_n_alternatives, 0, sizeof op_n_alternatives);
  memset (predicates, 0, sizeof predicates);
  memset (address_p, 0, sizeof address_p);
  memset (modes, 0, sizeof modes);
  memset (strict_low, 0, sizeof strict_low);
  memset (seen, 0, sizeof seen);

  /* 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;

  memcpy (d->constraints, constraints, sizeof constraints);
  memcpy (d->op_n_alternatives, op_n_alternatives, sizeof op_n_alternatives);
  memset (d->predicates, 0, sizeof predicates);
  memset (d->address_p, 0, sizeof address_p);
  memset (d->modes, 0, sizeof modes);
  memset (d->strict_low, 0, sizeof strict_low);

  validate_insn_alternatives (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)
     rtx insn;
{
  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;
  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.  */

  memset (constraints, 0, sizeof constraints);
  memset (op_n_alternatives, 0, sizeof op_n_alternatives);
  memset (predicates, 0, sizeof predicates);
  memset (address_p, 0, sizeof address_p);
  memset (modes, 0, sizeof modes);
  memset (strict_low, 0, sizeof strict_low);
  memset (seen, 0, sizeof seen);

  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;
  d->n_dups = num_dups;

  memcpy (d->constraints, constraints, sizeof constraints);
  memcpy (d->op_n_alternatives, op_n_alternatives, sizeof op_n_alternatives);
  memcpy (d->predicates, predicates, sizeof predicates);
  memcpy (d->address_p, address_p, sizeof address_p);
  memcpy (d->modes, modes, sizeof modes);
  memcpy (d->strict_low, strict_low, sizeof strict_low);

  d->template = 0;
  d->outfun = 0;
  validate_insn_alternatives (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)
     rtx split;
{
  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->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;

  memset (constraints, 0, sizeof constraints);
  memset (op_n_alternatives, 0, sizeof op_n_alternatives);
  memset (predicates, 0, sizeof predicates);
  memset (address_p, 0, sizeof address_p);
  memset (modes, 0, sizeof modes);
  memset (strict_low, 0, sizeof strict_low);
  memset (seen, 0, sizeof seen);

  /* 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 (XVECEXP (split, 0, i), 0, 0);

  d->n_operands = max_opno + 1;

  memset (d->constraints, 0, sizeof constraints);
  memset (d->op_n_alternatives, 0, sizeof op_n_alternatives);
  memset (d->predicates, 0, sizeof predicates);
  memset (d->address_p, 0, sizeof address_p);
  memset (d->modes, 0, sizeof modes);
  memset (d->strict_low, 0, sizeof strict_low);

  d->n_dups = 0;
  d->n_alternatives = 0;
  d->template = 0;
  d->outfun = 0;
}

PTR
xmalloc (size)
  size_t size;
{
  register PTR val = (PTR) malloc (size);

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

PTR
xrealloc (old, size)
  PTR old;
  size_t size;
{
  register PTR ptr;
  if (old)
    ptr = (PTR) realloc (old, size);
  else
    ptr = (PTR) malloc (size);
  if (!ptr)
    fatal ("virtual memory exhausted");
  return ptr;
}

void
fatal VPROTO ((const char *format, ...))
{
#ifndef ANSI_PROTOTYPES
  const char *format;
#endif
  va_list ap;

  VA_START (ap, format);

#ifndef ANSI_PROTOTYPES
  format = va_arg (ap, const char *);
#endif

  fprintf (stderr, "genoutput: ");
  vfprintf (stderr, format, ap);
  va_end (ap);
  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.");
}

static void
error VPROTO ((const char *format, ...))
{
#ifndef ANSI_PROTOTYPES
  const char *format;
#endif
  va_list ap;

  VA_START (ap, format);

#ifndef ANSI_PROTOTYPES
  format = va_arg (ap, const char *);
#endif

  fprintf (stderr, "genoutput: ");
  vfprintf (stderr, format, ap);
  va_end (ap);
  fprintf (stderr, "\n");

  have_error = 1;
}

int
main (argc, argv)
     int argc;
     char **argv;
{
  rtx desc;
  FILE *infile;
  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;
  next_index_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);
      if (GET_CODE (desc) == DEFINE_SPLIT)
	gen_split (desc);
      next_index_number++;
    }

  output_epilogue ();

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

  /* NOTREACHED */
  return 0;
}

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