* d10v_sim.h (SEXT56): Define.

[deliverable/binutils-gdb.git] / sim / igen / gen.c

/*  This file is part of the program psim.

    Copyright (C) 1994-1997, Andrew Cagney <cagney@highland.com.au>

    This program 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 of the License, or
    (at your option) any later version.

    This program 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 this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 
    */


#include "misc.h"
#include "lf.h"
#include "table.h"
#include "filter.h"

#include "igen.h"
#include "ld-insn.h"
#include "ld-decode.h"
#include "gen.h"

static insn_uint
sub_val (insn_uint val,
	 insn_field_entry *field,
	 int first_pos,
	 int last_pos)
{
  return ((val >> (field->last - last_pos))
	  & (((insn_uint)1 << (last_pos - first_pos + 1)) - 1));
}

static void
update_depth (lf *file,
	      gen_entry *entry,
	      int depth,
	      void *data)
{
  int *max_depth = (int*)data;
  if (*max_depth < depth)
    *max_depth = depth;
}


int
gen_entry_depth (gen_entry *table)
{
  int depth = 0;
  gen_entry_traverse_tree (NULL,
			   table,
			   1,
			   NULL, /*start*/
			   update_depth,
			   NULL, /*end*/
			   &depth); /* data */
  return depth;
}


static void
print_gen_entry_path (line_ref *line,
		      gen_entry *table,
		      error_func *print)
{
  if (table->parent == NULL)
    {
      if (table->top->processor != NULL)
	print (line, "%s", table->top->processor);
      else
	print (line, "");
    }
  else
    {
      print_gen_entry_path (line, table->parent, print);
      print (NULL, ".%d", table->opcode_nr);
    }
}

static void
print_gen_entry_insns (gen_entry *table,
		       error_func *print,
		       char *first_message,
		       char *next_message)
{
  insn_list *i;
  char *message;
  message = first_message;
  for (i = table->insns; i != NULL; i = i->next)
    {
      insn_entry *insn = i->insn;
      print_gen_entry_path (insn->line, table, print);
      print (NULL, ": %s.%s %s\n",
	     insn->format_name,
	     insn->name,
	     message);
      if (next_message != NULL)
	message = next_message;
    }
}


/* same as strcmp */
static int
insn_word_cmp (insn_word_entry *l, insn_word_entry *r)
{
  while (1)
    {
      int bit_nr;
      if (l == NULL && r == NULL)
	return 0; /* all previous fields the same */
      if (l == NULL)
	return -1; /* left shorter than right */
      if (r == NULL)
	return +1; /* left longer than right */
      for (bit_nr = 0;
	   bit_nr < options.insn_bit_size;
	   bit_nr++)
	{
	  if (l->bit[bit_nr]->mask < r->bit[bit_nr]->mask)
	    return -1;
	  if (l->bit[bit_nr]->mask > r->bit[bit_nr]->mask)
	    return 1;
	  if (l->bit[bit_nr]->value < r->bit[bit_nr]->value)
	    return -1;
	  if (l->bit[bit_nr]->value > r->bit[bit_nr]->value)
	    return 1;
	}
      l = l->next;
      r = r->next;
    }
}

static int
opcode_bit_cmp (opcode_bits *l,
		opcode_bits *r)
{
  if (l == NULL && r == NULL)
    return 0; /* all previous bits the same */
  if (l == NULL)
    return -1; /* left shorter than right */
  if (r == NULL)
    return +1; /* left longer than right */
  /* most significant word */
  if (l->field->word_nr < r->field->word_nr)
    return +1; /* left has more significant word */
  if (l->field->word_nr > r->field->word_nr)
    return -1; /* right has more significant word */
  /* most significant bit? */
  if (l->first < r->first)
    return +1; /* left as more significant bit */
  if (l->first > r->first)
    return -1; /* right as more significant bit */
  /* nr bits? */
  if (l->last < r->last)
    return +1; /* left as less bits */
  if (l->last > r->last)
    return -1; /* right as less bits */
  /* value? */
  if (l->value < r->value)
    return -1;
  if (l->value > r->value)
    return 1;
  return 0;
}

static int
opcode_bits_cmp (opcode_bits *l,
		 opcode_bits *r)
{
  while (1)
    {
      int cmp;
      if (l == NULL && r == NULL)
	return 0; /* all previous bits the same */
      cmp = opcode_bit_cmp (l, r);
      if (cmp != 0)
	return cmp;
      l = l->next;
      r = r->next;
    }
}

static opcode_bits *
new_opcode_bits (opcode_bits *old_bits,
		 int value,
		 int first,
		 int last,
		 insn_field_entry *field,
		 opcode_field *opcode)
{
  opcode_bits *new_bits = ZALLOC (opcode_bits);
  new_bits->field = field;
  new_bits->value = value;
  new_bits->first = first;
  new_bits->last = last;
  new_bits->opcode = opcode;
  
  if (old_bits != NULL)
    {
      opcode_bits *new_list;
      opcode_bits **last = &new_list;
      new_list = new_opcode_bits (old_bits->next,
				  old_bits->value,
				  old_bits->first,
				  old_bits->last,
				  old_bits->field,
				  old_bits->opcode);
      while (*last != NULL)
	{
	  int cmp = opcode_bit_cmp (new_bits, *last);
	  if (cmp < 0) /* new < new_list */
	    {
	      break;
	    }
	  if (cmp == 0)
	    {
	      ERROR ("Duplicated insn bits in list");
	    }
	  last = &(*last)->next;
	}
      new_bits->next = *last;
      *last = new_bits;
      return new_list;
    }
  else
    {
      return new_bits;
    }
}




typedef enum {
  merge_duplicate_insns,
  report_duplicate_insns,
} duplicate_insn_actions;

static insn_list *
insn_list_insert (insn_list **cur_insn_ptr,
		  int *nr_insns,
		  insn_entry *insn,
		  opcode_bits *expanded_bits,
		  opcode_field *opcodes,
		  int nr_prefetched_words,
		  duplicate_insn_actions duplicate_action)
{
  /* insert it according to the order of the fields & bits */
  while ((*cur_insn_ptr) != NULL)
    {
      int word_cmp = insn_word_cmp (insn->words,
				    (*cur_insn_ptr)->insn->words);
      if (word_cmp < 0)
	{
	  /* found insertion point - new_insn < cur_insn->next */
	  break;
	}
      else if (word_cmp == 0)
	{
	  /* words same, try for bit fields */
	  int bit_cmp = opcode_bits_cmp (expanded_bits,
					 (*cur_insn_ptr)->expanded_bits);
	  if (bit_cmp < 0)
	    {
	      /* found insertion point - new_insn < cur_insn->next */
	      break;
	    }
	  else if (bit_cmp == 0)
	    {
	      switch (duplicate_action)
		{
		case report_duplicate_insns:
		  /* two instructions with the same constant field
		     values across all words and bits */
		  warning (insn->line,
			   "Location of second (duplicated?) instruction");
		  error ((*cur_insn_ptr)->insn->line,
			 "Two instructions with identical constant fields\n");
		case merge_duplicate_insns:
		  /* Add the opcode path to the instructions list */
		  if (opcodes != NULL)
		    {
		      insn_opcodes **last = &(*cur_insn_ptr)->opcodes;
		      while (*last != NULL)
			{
			  last = &(*last)->next;
			}
		      (*last) = ZALLOC (insn_opcodes);
		      (*last)->opcode = opcodes;
		    }
		  /* Use the larger nr_prefetched_words */
		  if ((*cur_insn_ptr)->nr_prefetched_words < nr_prefetched_words)
		    (*cur_insn_ptr)->nr_prefetched_words = nr_prefetched_words;
		  return (*cur_insn_ptr);
		}
	    }
	}
      /* keep looking - new_insn > cur_insn->next */
      cur_insn_ptr = &(*cur_insn_ptr)->next;
    }
  
  /* create a new list entry and insert it */
  {
    insn_list *new_insn = ZALLOC (insn_list);
    new_insn->insn = insn;
    new_insn->expanded_bits = expanded_bits;
    new_insn->next = (*cur_insn_ptr);
    new_insn->nr_prefetched_words = nr_prefetched_words;
    if (opcodes != NULL)
      {
	new_insn->opcodes = ZALLOC (insn_opcodes);
	new_insn->opcodes->opcode = opcodes;
      }
    (*cur_insn_ptr) = new_insn;
  }
  
  *nr_insns += 1;

  return (*cur_insn_ptr);
}


extern void
gen_entry_traverse_tree (lf *file,
			 gen_entry *table,
			 int depth,
			 gen_entry_handler *start,
			 gen_entry_handler *leaf,
			 gen_entry_handler *end,
			 void *data)
{
  gen_entry *entry;
  
  ASSERT (table != NULL);
  ASSERT (table->opcode != NULL);
  ASSERT (table->nr_entries > 0);
  ASSERT (table->entries != 0);
  
  /* prefix */
  if (start != NULL && depth >= 0)
    {
      start (file, table, depth, data);
    }
  /* infix leaves */
  for (entry = table->entries;
       entry != NULL;
       entry = entry->sibling)
    {
      if (entry->entries != NULL && depth != 0)
	{
	  gen_entry_traverse_tree (file, entry, depth + 1,
				   start, leaf, end, data);
	}
      else if (depth >= 0)
	{
	  if (leaf != NULL)
	    {
	      leaf (file, entry, depth, data);
	    }
	}
    }
  /* postfix */
  if (end != NULL && depth >= 0)
    {
      end (file, table, depth, data);
    }
}



/* create a list element containing a single gen_table entry */

static gen_list *
make_table (insn_table *isa,
	    decode_table *rules,
	    char *processor)
{
  insn_entry *insn;
  gen_list *entry = ZALLOC (gen_list);
  entry->table = ZALLOC (gen_entry);
  entry->table->top = entry;
  entry->processor = processor;
  entry->isa = isa;
  for (insn = isa->insns; insn != NULL; insn = insn->next)
    {
      if (processor == NULL
	  || insn->processors == NULL
	  || filter_is_member (insn->processors, processor))
	{
	  insn_list_insert (&entry->table->insns,
			    &entry->table->nr_insns,
			    insn,
			    NULL, /* expanded_bits - none yet */
			    NULL, /* opcodes - none yet */
			    0, /* nr_prefetched_words - none yet */
			    report_duplicate_insns);
	}
    }
  entry->table->opcode_rule = rules;
  return entry;
}


gen_table *
make_gen_tables (insn_table *isa,
		 decode_table *rules)
{
  gen_table *gen = ZALLOC (gen_table);
  gen->isa = isa;
  gen->rules = rules;
  if (options.gen.multi_sim)
    {
      gen_list **last = &gen->tables;
      char *processor;
      filter *processors;
      if (options.model_filter != NULL)
	processors = options.model_filter;
      else
	processors = isa->model->processors;
      for (processor = filter_next (processors, "");
	   processor != NULL;
	   processor = filter_next (processors, processor))
	{
	  *last = make_table (isa, rules, processor);
	  last = &(*last)->next;
	}
    }
  else
    {
      gen->tables = make_table (isa, rules, NULL);
    }
  return gen;
}
  
  
/****************************************************************/

#if 0
typedef enum {
  field_is_not_constant = 0,
  field_constant_int = 1,
  field_constant_reserved = 2,
  field_constant_string = 3
} constant_field_types;

static constant_field_types
insn_field_is_constant (insn_field *field,
		        decode_table *rule)
{
  switch (field->type)
    {
    case insn_field_int:
      /* field is an integer */
      return field_constant_int;
    case insn_field_reserved:
      /* field is `/' and treating that as a constant */
      if (rule->with_zero_reserved)
	return field_constant_reserved;
      else
	return field_is_not_constant;
    case insn_field_wild:
      return field_is_not_constant; /* never constant */
    case insn_field_string:
      /* field, though variable, is on the list of forced constants */
      if (filter_is_member (rule->constant_field_names, field->val_string))
	return field_constant_string;
      else
	return field_is_not_constant;
    }
  ERROR ("Internal error");
  return field_is_not_constant;
}
#endif


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


/* Is the bit, according to the decode rule, identical across all the
   instructions? */
static int
insns_bit_useless (insn_list *insns,
		   decode_table *rule,
		   int bit_nr)
{
  insn_list *entry;
  int value = -1;
  int is_useless = 1; /* cleared if something actually found */
  for (entry = insns; entry != NULL; entry = entry->next)
    {
      insn_word_entry *word = entry->insn->word[rule->word_nr];
      insn_bit_entry *bit = word->bit[bit_nr];
      switch (bit->field->type)
	{
	case insn_field_wild:
	case insn_field_reserved:
	  /* neither useless or useful - ignore */
	  break;
	case insn_field_int:
	  switch (rule->search)
	    {
	    case decode_find_strings:
	      /* an integer isn't a string */
	      return 1;
	    case decode_find_constants:
	    case decode_find_mixed:
	      /* an integer is useful if its value isn't the same
                 between all instructions? */
	      if (value < 0)
		value = bit->value;
	      else if (value != bit->value)
		is_useless = 0;
	      break;
	    }
	  break;
	case insn_field_string:
	  switch (rule->search)
	    {
	    case decode_find_strings:
	      /* at least one string, keep checking */
	      is_useless = 0;
	      break;
	    case decode_find_constants:
	    case decode_find_mixed:
	      /* a string field forced to constant */
	      if (filter_is_member (rule->constant_field_names,
				    bit->field->val_string))
		is_useless = 0;
	      else if (rule->search == decode_find_constants)
		/* the string field isn't constant */
		return 1;
	      break;
	    }
	}
    }
  return is_useless;
}


/* go through a gen-table's list of instruction formats looking for a
   range of bits that meet the decode table RULEs requirements */

static opcode_field *
gen_entry_find_opcode_field (insn_list *insns,
			     decode_table *rule,
			     int string_only)
{
  opcode_field curr_opcode;
  ASSERT (rule != NULL);

  memset (&curr_opcode, 0, sizeof (curr_opcode));
  curr_opcode.word_nr = rule->word_nr;
  curr_opcode.first = rule->first;
  curr_opcode.last = rule->last;

  /* Try to reduce the size of first..last in accordance with the
     decode rules */

  while (curr_opcode.first <= rule->last)
    {
      if (insns_bit_useless (insns, rule, curr_opcode.first))
	curr_opcode.first ++;
      else
	break;
    }
  while (curr_opcode.last >= rule->first)
    {
      if (insns_bit_useless (insns, rule, curr_opcode.last))
	curr_opcode.last --;
      else
	break;
    }


#if 0
  for (entry = insns; entry != NULL; entry = entry->next)
    {
      insn_word_entry *fields = entry->insn->word[rule->word_nr];
      opcode_field new_opcode;
      
      ASSERT (fields != NULL);
      
      /* find a start point for the opcode field */
      new_opcode.first = rule->first;
      while (new_opcode.first <= rule->last
	     && (!string_only
		 || (insn_field_is_constant(fields->bit[new_opcode.first], rule)
		     != field_constant_string))
	     && (string_only
		 || (insn_field_is_constant(fields->bit[new_opcode.first], rule)
		     == field_is_not_constant)))
	{
	  int new_first = fields->bit[new_opcode.first]->last + 1;
	  ASSERT (new_first > new_opcode.first);
	  new_opcode.first = new_first;
	}
      ASSERT(new_opcode.first > rule->last
	     || (string_only
		 && insn_field_is_constant(fields->bit[new_opcode.first],
					   rule) == field_constant_string)
	     || (!string_only
		 && insn_field_is_constant(fields->bit[new_opcode.first],
					   rule)));
      
      /* find the end point for the opcode field */
      new_opcode.last = rule->last;
      while (new_opcode.last >= rule->first
	     && (!string_only
		 || insn_field_is_constant(fields->bit[new_opcode.last],
					   rule) != field_constant_string)
	     && (string_only
		 || !insn_field_is_constant(fields->bit[new_opcode.last],
					    rule)))
	{
	  int new_last = fields->bit[new_opcode.last]->first - 1;
	  ASSERT (new_last < new_opcode.last);
	  new_opcode.last = new_last;
	}
      ASSERT(new_opcode.last < rule->first
	     || (string_only
		 && insn_field_is_constant(fields->bit[new_opcode.last],
					   rule) == field_constant_string)
	     || (!string_only
		 && insn_field_is_constant(fields->bit[new_opcode.last],
					   rule)));
      
      /* now see if our current opcode needs expanding to include the
	 interesting fields within this instruction */
      if (new_opcode.first <= rule->last
	  && curr_opcode.first > new_opcode.first)
	curr_opcode.first = new_opcode.first;
      if (new_opcode.last >= rule->first
	  && curr_opcode.last < new_opcode.last)
	curr_opcode.last = new_opcode.last;
      
    }
#endif

  /* did the final opcode field end up being empty? */
  if (curr_opcode.first > curr_opcode.last)
    {
      return NULL;
    }
  ASSERT (curr_opcode.last >= rule->first);
  ASSERT (curr_opcode.first <= rule->last);
  ASSERT (curr_opcode.first <= curr_opcode.last);

  /* Ensure that, for the non string only case, the opcode includes
     the range forced_first .. forced_last */
  if (!string_only
      && curr_opcode.first > rule->force_first)
    {
      curr_opcode.first = rule->force_first;
    }
  if (!string_only
      && curr_opcode.last < rule->force_last)
    {
      curr_opcode.last = rule->force_last;
    }

  /* For the string only case, force just the lower bound (so that the
     shift can be eliminated) */
  if (string_only
      && rule->force_last == options.insn_bit_size - 1)
    {
      curr_opcode.last = options.insn_bit_size - 1;
    }

  /* handle any special cases */
  switch (rule->type)
    {
    case normal_decode_rule:
      /* let the above apply */
      curr_opcode.nr_opcodes =
	(1 << (curr_opcode.last - curr_opcode.first + 1));
      break;
    case boolean_rule:
      curr_opcode.is_boolean = 1;
      curr_opcode.boolean_constant = rule->constant;
      curr_opcode.nr_opcodes = 2;
      break;
    }

  {
    opcode_field *new_field = ZALLOC (opcode_field);
    memcpy (new_field, &curr_opcode, sizeof (opcode_field));
    return new_field;
  }
}


static void
gen_entry_insert_insn (gen_entry *table,
		       insn_entry *old_insn,
		       int new_word_nr,
		       int new_nr_prefetched_words,
		       int new_opcode_nr,
		       opcode_bits *new_bits)
{
  gen_entry **entry = &table->entries;
  
  /* find the new table for this entry */
  while ((*entry) != NULL && (*entry)->opcode_nr < new_opcode_nr)
    {
      entry = &(*entry)->sibling;
    }
  
  if ((*entry) == NULL || (*entry)->opcode_nr != new_opcode_nr)
    {
      /* insert the missing entry */
      gen_entry *new_entry = ZALLOC (gen_entry);
      new_entry->sibling = (*entry);
      (*entry) = new_entry;
      table->nr_entries++;
      /* fill it in */
      new_entry->top = table->top;
      new_entry->opcode_nr = new_opcode_nr;
      new_entry->word_nr = new_word_nr;
      new_entry->expanded_bits = new_bits;
      new_entry->opcode_rule = table->opcode_rule->next;
      new_entry->parent = table;
      new_entry->nr_prefetched_words = new_nr_prefetched_words;
    }
  /* ASSERT new_bits == cur_entry bits */
  ASSERT ((*entry) != NULL && (*entry)->opcode_nr == new_opcode_nr);
  insn_list_insert (&(*entry)->insns,
		    &(*entry)->nr_insns,
		    old_insn,
		    NULL, /* expanded_bits - only in final list */
		    NULL, /* opcodes - only in final list */
		    new_nr_prefetched_words, /* for this table */
		    report_duplicate_insns);
}


static void
gen_entry_expand_opcode (gen_entry *table,
			 insn_entry *instruction,
			 int bit_nr,
			 int opcode_nr,
			 opcode_bits *bits)
{
  if (bit_nr > table->opcode->last)
    {
      /* Only include the hardwired bit information with an entry IF
         that entry (and hence its functions) are being duplicated.  */
      if (table->opcode_rule->with_duplicates)
	{
	  gen_entry_insert_insn (table, instruction,
				 table->opcode->word_nr,
				 table->nr_prefetched_words,
				 opcode_nr, bits);
	}
      else
	{
	  gen_entry_insert_insn (table, instruction,
				 table->opcode->word_nr,
				 table->nr_prefetched_words,
				 opcode_nr, NULL);
	}
    }
  else
    {
      insn_word_entry *word = instruction->word[table->opcode->word_nr];
      insn_field_entry *field = word->bit[bit_nr]->field;
      int last_pos = ((field->last < table->opcode->last)
		      ? field->last : table->opcode->last);
      int first_pos = ((field->first > table->opcode->first)
		       ? field->first : table->opcode->first);
      int width = last_pos - first_pos + 1;
      switch (field->type)
	{
	case insn_field_int:
	  {
	    int val;
	    val = sub_val (field->val_int, field, first_pos, last_pos);
	    gen_entry_expand_opcode (table, instruction,
				     last_pos + 1,
				     ((opcode_nr << width) | val),
				     bits);
	    break;
	  }
	default:
	  {
	    if (field->type == insn_field_reserved)
	      gen_entry_expand_opcode (table, instruction,
				       last_pos + 1,
				       ((opcode_nr << width)),
				       bits);
	    else
	      {
		int val;
		int last_val = (table->opcode->is_boolean
				? 2 : (1 << width));
		for (val = 0; val < last_val; val++)
		  {
		    /* check to see if the value has been limited */
		    insn_field_exclusion *exclusion;
		    for (exclusion = field->exclusions;
			 exclusion != NULL;
			 exclusion = exclusion->next)
		      {
			int value = sub_val (exclusion->value, field,
					     first_pos, last_pos);
			if (value == val)
			  break;
		      }
		    if (exclusion == NULL)
		      {
			/* Only add additional hardwired bit
                           information if the entry is not going to
                           later be combined */
			if (table->opcode_rule->with_combine)
			  {
			    gen_entry_expand_opcode (table, instruction,
						     last_pos + 1,
						     ((opcode_nr << width) | val),
						     bits);
			  }
			else
			  {
			    opcode_bits *new_bits = new_opcode_bits (bits, val,
								     first_pos, last_pos,
								     field,
								     table->opcode);
			    gen_entry_expand_opcode (table, instruction,
						     last_pos + 1,
						     ((opcode_nr << width) | val),
						     new_bits);
			  }
		      }
		  }
	      }
	  }
	}
    }
}

static void
gen_entry_insert_expanding (gen_entry *table,
			    insn_entry *instruction)
{
  gen_entry_expand_opcode (table,
			   instruction,
			   table->opcode->first,
			   0,
			   table->expanded_bits);
}


static int
insns_match_format_names (insn_list *insns,
			  filter *format_names)
{
  if (format_names != NULL)
    {
      insn_list *i;
      for (i = insns; i != NULL; i = i->next)
	{
	  if ( i->insn->format_name != NULL
	       && !filter_is_member (format_names, i->insn->format_name))
	    return 0;
	}
    }
  return 1;
}

static int
table_matches_path (gen_entry *table,
		    decode_path_list *paths)
{
  if (paths == NULL)
    return 1;
  while (paths != NULL)
    {
      gen_entry *entry = table;
      decode_path *path = paths->path;
      while (1)
	{
	  if (entry == NULL && path == NULL)
	    return 1;
	  if (entry == NULL || path == NULL)
	    break;
	  if (entry->opcode_nr != path->opcode_nr)
	    break;
	  entry = entry->parent;
	  path = path->parent;
	}
      paths = paths->next;
    }
  return 0;
}


static int
insns_match_conditions (insn_list *insns,
			decode_cond *conditions)
{
  if (conditions != NULL)
    {
      insn_list *i;
      for (i = insns; i != NULL; i = i->next)
	{
	  decode_cond *cond;
	  for (cond = conditions; cond != NULL; cond = cond->next)
	    {
	      int bit_nr;
	      if (i->insn->nr_words <= cond->word_nr)
		return 0;
	      for (bit_nr = 0; bit_nr < options.insn_bit_size; bit_nr++)
		{
		  if (!cond->mask[bit_nr])
		    continue;
		  if (!i->insn->word[cond->word_nr]->bit[bit_nr]->mask)
		    return 0;
		  if ((i->insn->word[cond->word_nr]->bit[bit_nr]->value
		       == cond->value[bit_nr])
		      == !cond->is_equal)
		    return 0;
		}
	    }
	}
    }
  return 1;
}

static int
insns_match_nr_words (insn_list *insns,
		      int nr_words)
{
  insn_list *i;
  for (i = insns; i != NULL; i = i->next)
    {
      if (i->insn->nr_words < nr_words)
	return 0;
    }
  return 1;
}

static int
insn_list_cmp (insn_list *l,
	       insn_list *r)
{
  while (1)
    {
      insn_entry *insn;
      if (l == NULL && r == NULL)
	return 0;
      if (l == NULL)
	return -1;
      if (r == NULL)
	return 1;
      if (l->insn != r->insn)
	return -1; /* somewhat arbitrary at present */
      /* skip this insn */
      insn = l->insn;
      while (l != NULL && l->insn == insn)
	l = l->next;
      while (r != NULL && r->insn == insn)
	r = r->next;
    }
}



static void
gen_entry_expand_insns (gen_entry *table)
{
  decode_table *opcode_rule;

  ASSERT(table->nr_insns >= 1);
  
  /* determine a valid opcode */
  for (opcode_rule = table->opcode_rule;
       opcode_rule != NULL;
       opcode_rule = opcode_rule->next)
    {
      char *discard_reason;
      if (table->top->processor != NULL
	  && opcode_rule->model_names != NULL
	  && !filter_is_member (opcode_rule->model_names,
				table->top->processor))
	{
	  /* the rule isn't applicable to this processor */
	  discard_reason = "wrong model";
	}
      else if (table->nr_insns == 1 && opcode_rule->conditions == NULL)
	{
	  /* for safety, require a pre-codition when attempting to
             apply a rule to a single instruction */
	  discard_reason = "need pre-condition when nr-insn == 1";
	}
      else if (table->nr_insns == 1 && !opcode_rule->with_duplicates)
	{
	  /* Little point in expanding a single instruction when we're
             not duplicating the semantic functions that this table
             calls */
	  discard_reason = "need duplication with nr-insns == 1";
	}
      else if (!insns_match_format_names (table->insns, opcode_rule->format_names))
	{
	  discard_reason = "wrong format name";
	}
      else if (!insns_match_nr_words (table->insns, opcode_rule->word_nr + 1))
	{
	  discard_reason = "wrong nr words";
	}
      else if (!table_matches_path (table, opcode_rule->paths))
	{
	  discard_reason = "path failed";
	}
      else if (!insns_match_conditions (table->insns, opcode_rule->conditions))
	{
	  discard_reason = "condition failed";
	}
      else
	{
	  discard_reason = "no opcode field";
	  table->opcode =
	    gen_entry_find_opcode_field (table->insns,
					 opcode_rule,
					 table->nr_insns == 1/*string-only*/
					 );
	  if (table->opcode != NULL)
	    {
	      table->opcode_rule = opcode_rule;
	      break;
	    }
	}

      if (options.trace.rule_rejection)
	{
	  print_gen_entry_path (opcode_rule->line, table, notify);
	  notify (NULL, ": rule discarded - %s\n", discard_reason);
	}
    }
  
  /* did we find anything */
  if (opcode_rule == NULL)
    {
      /* the decode table failed, this set of instructions haven't
         been uniquely identified */
      if (table->nr_insns > 1)
	{
	  print_gen_entry_insns (table, warning,
				 "was not uniquely decoded",
				 "decodes to the same entry");
	  error (NULL, "");
	}
      return;
    }

  /* Determine the number of words that must have been prefetched for
     this table to function */
  if (table->parent == NULL)
    table->nr_prefetched_words = table->opcode_rule->word_nr + 1;
  else if (table->opcode_rule->word_nr + 1 > table->parent->nr_prefetched_words)
    table->nr_prefetched_words = table->opcode_rule->word_nr + 1;
  else
    table->nr_prefetched_words = table->parent->nr_prefetched_words;

  /* back link what we found to its parent */
  if (table->parent != NULL)
    {
      ASSERT(table->parent->opcode != NULL);
      table->opcode->parent = table->parent->opcode;
    }

  /* expand the raw instructions according to the opcode */
  {
    insn_list *entry;
    for (entry = table->insns; entry != NULL; entry = entry->next)
      {
	gen_entry_insert_expanding (table, entry->insn);
      }
  }

  if (options.trace.rule_selection)
    {
      print_gen_entry_path (table->opcode_rule->line, table, notify);
      notify (NULL,
	      ": decode - word %d, bits [%d..%d] in [%d..%d], opcodes %d, entries %d\n",
	      table->opcode->word_nr,
	      i2target (options.hi_bit_nr, table->opcode->first),
	      i2target (options.hi_bit_nr, table->opcode->last),
	      i2target (options.hi_bit_nr, table->opcode_rule->first),
	      i2target (options.hi_bit_nr, table->opcode_rule->last),
	      table->opcode->nr_opcodes,
	      table->nr_entries);
    }

  /* dump the results */
  if (options.trace.entries)
    {
      gen_entry *entry;
      for (entry = table->entries; entry != NULL; entry = entry->sibling)
	{
	  insn_list *l;
	  print_gen_entry_path (table->opcode_rule->line, entry, notify);
	  notify (NULL, ": %d - entries %d -",
		  entry->opcode_nr,
		  entry->nr_insns);
	  for (l = entry->insns; l != NULL; l = l->next)
	    notify (NULL, " %s.%s", l->insn->format_name, l->insn->name);
	  notify (NULL, "\n");
	}
    }
	
  /* perform a combine pass if needed */
  if (table->opcode_rule->with_combine)
    {
      gen_entry *entry;
      for (entry = table->entries; entry != NULL; entry = entry->sibling)
	{
	  if (entry->combined_parent == NULL)
	    {
	      gen_entry **last = &entry->combined_next;
	      gen_entry *alt;
	      for (alt = entry->sibling; alt != NULL; alt = alt->sibling)
		{
		  if (alt->combined_parent == NULL
		      && insn_list_cmp (entry->insns, alt->insns) == 0)
		    {
		      alt->combined_parent = entry;
		      *last = alt;
		      last = &alt->combined_next;
		    }
		}
	    }
	}
      if (options.trace.combine)
	{
	  int nr_unique = 0;
	  gen_entry *entry;
	  for (entry = table->entries; entry != NULL; entry = entry->sibling)
	    {
	      if (entry->combined_parent == NULL)
		{
		  insn_list *l;
		  gen_entry *duplicate;
		  nr_unique++;
		  print_gen_entry_path (table->opcode_rule->line, entry, notify);
		  for (duplicate = entry->combined_next;
		       duplicate != NULL;
		       duplicate = duplicate->combined_next)
		    {
		      notify (NULL, "+%d", duplicate->opcode_nr);
		    }
		  notify (NULL, ": entries %d -", entry->nr_insns);
		  for (l = entry->insns; l != NULL; l = l->next)
		    {
		      notify (NULL, " %s.%s",
			      l->insn->format_name,
			      l->insn->name);
		    }
		  notify (NULL, "\n");
		}
	    }
	  print_gen_entry_path (table->opcode_rule->line, table, notify);
	  notify (NULL, ": combine - word %d, bits [%d..%d] in [%d..%d], opcodes %d, entries %d, unique %d\n",
		  table->opcode->word_nr,
		  i2target (options.hi_bit_nr, table->opcode->first),
		  i2target (options.hi_bit_nr, table->opcode->last),
		  i2target (options.hi_bit_nr, table->opcode_rule->first),
		  i2target (options.hi_bit_nr, table->opcode_rule->last),
		  table->opcode->nr_opcodes,
		  table->nr_entries,
		  nr_unique);
	}
    }
	
  /* Check that the rule did more than re-arange the order of the
     instructions */
  {
      gen_entry *entry;
      for (entry = table->entries; entry != NULL; entry = entry->sibling)
	{
	  if (entry->combined_parent == NULL)
	    {
	      if (insn_list_cmp (table->insns, entry->insns) == 0)
		{
		  print_gen_entry_path (table->opcode_rule->line, table, warning);
		  warning (NULL, ": Applying rule just copied all instructions\n");
		  print_gen_entry_insns (entry, warning, "Copied", NULL);
		  error (NULL, "");
		}
	    }
	}    
  }

  /* if some form of expanded table, fill in the missing dots */
  switch (table->opcode_rule->gen)
    {
    case padded_switch_gen:
    case array_gen:
    case goto_switch_gen:
      if (!table->opcode->is_boolean)
	{
	  gen_entry **entry = &table->entries;
	  gen_entry *illegals = NULL;
	  gen_entry **last_illegal = &illegals;
	  int opcode_nr = 0;
	  while (opcode_nr < table->opcode->nr_opcodes)
	    {
	      if ((*entry) == NULL || (*entry)->opcode_nr != opcode_nr)
		{
		  /* missing - insert it under our feet at *entry */
		  gen_entry_insert_insn (table,
					 table->top->isa->illegal_insn,
					 table->opcode->word_nr,
					 0, /* nr_prefetched_words == 0 for invalid */
					 opcode_nr, NULL);
		  ASSERT ((*entry) != NULL);
		  ASSERT ((*entry)->opcode_nr == opcode_nr);
		  (*last_illegal) = *entry;
		  (*last_illegal)->combined_parent = illegals;
		  last_illegal = &(*last_illegal)->combined_next;
		}
	      entry = &(*entry)->sibling;
	      opcode_nr++;
	    }
	  /* oops, will have pointed the first illegal insn back to
             its self.  Fix this */
	  if (illegals != NULL)
	    illegals->combined_parent = NULL;
	}
      break;
    case switch_gen:
    case invalid_gen:
      /* ignore */
      break;
    }

  /* and do the same for the newly created sub entries but *only*
     expand entries that haven't been combined. */
  {
    gen_entry *entry;
    for (entry = table->entries; entry != NULL; entry =  entry->sibling)
      {
	if (entry->combined_parent == NULL)
	  {
	    gen_entry_expand_insns (entry);
	  }
      }
  }
}

void
gen_tables_expand_insns (gen_table *gen)
{
  gen_list *entry;
  for (entry = gen->tables; entry != NULL; entry = entry->next)
    {
      gen_entry_expand_insns (entry->table);
    }
}


/* create a list of all the semantic functions that need to be
   generated.  Eliminate any duplicates. Verify that the decode stage
   worked. */

static void
make_gen_semantics_list (lf *file,
			 gen_entry *entry,
			 int depth,
			 void *data)
{
  gen_table *gen = (gen_table*) data;
  insn_list *insn;
  /* Not interested in an entrie that have been combined into some
     other entry at the same level */
  if (entry->combined_parent != NULL)
    return;

  /* a leaf should contain exactly one instruction. If not the decode
     stage failed. */
  ASSERT (entry->nr_insns == 1);

  /* Enter this instruction into the list of semantic functions. */
  insn = insn_list_insert (&gen->semantics, &gen->nr_semantics,
			   entry->insns->insn,
			   entry->expanded_bits,
			   entry->parent->opcode,
			   entry->insns->nr_prefetched_words,
			   merge_duplicate_insns);
  /* point the table entry at the real semantic function */
  ASSERT (insn != NULL);
  entry->insns->semantic = insn;
}


void
gen_tables_expand_semantics (gen_table *gen)
{
  gen_list *entry;
  for (entry = gen->tables; entry != NULL; entry = entry->next)
    {
      gen_entry_traverse_tree (NULL,
			       entry->table,
			       1, /* depth */
			       NULL, /* start-handler */
			       make_gen_semantics_list, /* leaf-handler */
			       NULL, /* end-handler */
			       gen); /* data */
  }
}



#ifdef MAIN


static void
dump_opcode_field (lf *file,
		   char *prefix,
		   opcode_field *field,
		   char *suffix,
		   int levels)
{
  lf_printf (file, "%s(opcode_field *) 0x%lx", prefix, (long) field);
  if (levels && field != NULL) {
    lf_indent (file, +1);
    lf_printf (file, "\n(first %d)", field->first);
    lf_printf (file, "\n(last %d)", field->last);
    lf_printf (file, "\n(nr_opcodes %d)", field->nr_opcodes);
    lf_printf (file, "\n(is_boolean %d)", field->is_boolean);
    lf_printf (file, "\n(boolean_constant %d)", field->boolean_constant);
    dump_opcode_field(file, "\n(parent ", field->parent, ")", levels - 1);
    lf_indent (file, -1);
  }
  lf_printf (file, "%s", suffix);
}


static void
dump_opcode_bits (lf *file,
		  char *prefix,
		  opcode_bits *bits,
		  char *suffix,
		  int levels)
{
  lf_printf (file, "%s(opcode_bits *) 0x%lx", prefix, (long) bits);
  
  if (levels && bits != NULL)
    {
      lf_indent (file, +1);
      lf_printf (file, "\n(value %d)", bits->value);
      dump_opcode_field (file, "\n(opcode ", bits->opcode, ")", 0);
      dump_insn_field (file, "\n(field ", bits->field, ")");
      dump_opcode_bits (file, "\n(next ", bits->next, ")", levels - 1);
      lf_indent (file, -1);
    }
  lf_printf (file, "%s", suffix);
}



static void
dump_insn_list (lf *file,
		char *prefix,
		insn_list *entry,
		char *suffix)
{
  lf_printf (file, "%s(insn_list *) 0x%lx", prefix, (long) entry);

  if (entry != NULL) {
    lf_indent (file, +1);
    dump_insn_entry (file, "\n(insn ", entry->insn, ")");
    lf_printf (file, "\n(next 0x%lx)", (long) entry->next);
    lf_indent (file, -1);
  }
  lf_printf (file, "%s", suffix);
}


static void
dump_insn_word_entry_list_entries (lf *file,
			       char *prefix,
			       insn_list *entry,
			       char *suffix)
{
  lf_printf (file, "%s", prefix);
  while (entry != NULL)
    {
      dump_insn_list (file, "\n(", entry, ")");
      entry = entry->next;
    }
  lf_printf (file, "%s", suffix);
}


static void
dump_gen_entry (lf *file,
		char *prefix,
		gen_entry *table,
		char *suffix,
		int levels)
{

  lf_printf (file, "%s(gen_entry *) 0x%lx", prefix, (long) table);

  if (levels && table != NULL) {

    lf_indent (file, +1);
    lf_printf (file, "\n(opcode_nr %d)", table->opcode_nr);
    lf_printf (file, "\n(word_nr %d)", table->word_nr);
    dump_opcode_bits (file, "\n(expanded_bits ", table->expanded_bits, ")", -1);
    lf_printf (file, "\n(nr_insns %d)", table->nr_insns);
    dump_insn_word_entry_list_entries (file, "\n(insns ", table->insns, ")");
    dump_decode_rule (file, "\n(opcode_rule ", table->opcode_rule, ")");
    dump_opcode_field (file, "\n(opcode ", table->opcode, ")", 0);
    lf_printf (file, "\n(nr_entries %d)", table->nr_entries);
    dump_gen_entry (file, "\n(entries ", table->entries, ")", table->nr_entries);
    dump_gen_entry (file, "\n(sibling ", table->sibling, ")", levels - 1);
    dump_gen_entry (file, "\n(parent ", table->parent, ")", 0);
    lf_indent (file, -1);
  }
  lf_printf (file, "%s", suffix);
}

static void
dump_gen_list (lf *file,
	       char *prefix,
	       gen_list *entry,
	       char *suffix,
	       int levels)
{
  while (entry != NULL)
    {
      lf_printf (file, "%s(gen_list *) 0x%lx", prefix, (long) entry);
      dump_gen_entry (file, "\n(", entry->table, ")", levels);
      lf_printf (file, "\n(next (gen_list *) 0x%lx)", (long) entry->next);
      lf_printf (file, "%s", suffix);
    }
}


static void
dump_gen_table (lf *file,
		char *prefix,
		gen_table *gen,
		char *suffix,
		int levels)
{
  lf_printf (file, "%s(gen_table *) 0x%lx", prefix, (long) gen);
  lf_printf (file, "\n(isa (insn_table *) 0x%lx)", (long) gen->isa);
  lf_printf (file, "\n(rules (decode_table *) 0x%lx)", (long) gen->rules);
  dump_gen_list (file, "\n(", gen->tables, ")", levels);
  lf_printf (file, "%s", suffix);
}


igen_options options;

int
main (int argc,
      char **argv)
{
  decode_table *decode_rules;
  insn_table *instructions;
  gen_table *gen;
  lf *l;

  if (argc != 7)
    error (NULL, "Usage: insn <filter-in> <hi-bit-nr> <insn-bit-size> <widths> <decode-table> <insn-table>\n");

  INIT_OPTIONS (options);

  filter_parse (&options.flags_filter, argv[1]);

  options.hi_bit_nr = a2i(argv[2]);
  options.insn_bit_size = a2i(argv[3]);
  options.insn_specifying_widths = a2i(argv[4]);
  ASSERT(options.hi_bit_nr < options.insn_bit_size);

  instructions = load_insn_table (argv[6], NULL);
  decode_rules = load_decode_table (argv[5]);
  gen = make_gen_tables (instructions, decode_rules);

  gen_tables_expand_insns (gen);

  l = lf_open ("-", "stdout", lf_omit_references, lf_is_text, "tmp-ld-insn");

  dump_gen_table (l, "(", gen, ")\n", -1);
  return 0;
}

#endif