Initial creation of sourceware repositorygdb-4_18-branchpoint

1 files changed, 1765 insertions, 0 deletions

diff --git a/sim/igen/gen.c b/sim/igen/gen.c
new file mode 100644
index 0000000..de88619
--- /dev/null
+++ b/sim/igen/gen.c
@@ -0,0 +1,1765 @@
+/*  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,
+	 int val_last_pos,
+	 int first_pos,
+	 int last_pos)
+{
+  return ((val >> (val_last_pos - 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->model != NULL)
+	print (line, "%s", table->top->model->name);
+      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_field_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]->field->type != insn_field_string)
+	    continue;
+	  if (r->bit[bit_nr]->field->type != insn_field_string)
+	    continue;
+	  if (l->bit[bit_nr]->field->conditions == NULL)
+	    continue;
+	  if (r->bit[bit_nr]->field->conditions == NULL)
+	    continue;
+	  if (0)
+	    printf ("%s%s%s VS %s%s%s\n",
+		    l->bit[bit_nr]->field->val_string,
+		    l->bit[bit_nr]->field->conditions->test == insn_field_cond_eq ? "=" : "!",
+		    l->bit[bit_nr]->field->conditions->string,	
+		    r->bit[bit_nr]->field->val_string,
+		    r->bit[bit_nr]->field->conditions->test == insn_field_cond_eq ? "=" : "!",
+		    r->bit[bit_nr]->field->conditions->string);
+	  if (l->bit[bit_nr]->field->conditions->test == insn_field_cond_eq
+	      && r->bit[bit_nr]->field->conditions->test == insn_field_cond_eq)
+	    {
+	      if (l->bit[bit_nr]->field->conditions->type == insn_field_cond_field
+		  && r->bit[bit_nr]->field->conditions->type == insn_field_cond_field)
+		/* somewhat arbitrary */
+		{
+		  int cmp = strcmp (l->bit[bit_nr]->field->conditions->string,
+				    r->bit[bit_nr]->field->conditions->string);
+		  if (cmp != 0)
+		    return cmp;
+		  else
+		    continue;
+		}
+	      if (l->bit[bit_nr]->field->conditions->type == insn_field_cond_field)
+		return +1;
+	      if (r->bit[bit_nr]->field->conditions->type == insn_field_cond_field)
+		return -1;
+	      /* The case of both fields having constant values should have
+		 already have been handled because such fields are converted
+		 into normal constant fields. */
+	      continue;
+	    }
+	  if (l->bit[bit_nr]->field->conditions->test == insn_field_cond_eq)
+	    return +1; /* left = only */
+	  if (r->bit[bit_nr]->field->conditions->test == insn_field_cond_eq)
+	    return -1; /* right = only */
+	  /* FIXME: Need to some what arbitrarily order conditional lists */
+	  continue;
+	}
+      l = l->next;
+      r = r->next;
+    }
+}
+
+/* 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;
+    }
+}
+
+/* same as strcmp */
+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;
+}
+
+
+/* same as strcmp */
+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;
+    }
+}
+
+/* same as strcmp */
+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 */
+  for (; (*cur_insn_ptr) != NULL; cur_insn_ptr = &(*cur_insn_ptr)->next)
+    {
+      int cmp;
+
+      /* key#1 sort according to the constant fields of each instruction */
+      cmp = insn_word_cmp (insn->words, (*cur_insn_ptr)->insn->words);
+      if (cmp < 0)
+	break;
+      else if (cmp > 0)
+	continue;
+
+      /* key#2 sort according to the expanded bits of each instruction */
+      cmp = opcode_bits_cmp (expanded_bits, (*cur_insn_ptr)->expanded_bits);
+      if (cmp < 0)
+	break;
+      else if (cmp > 0)
+	continue;
+
+      /* key#3 sort according to the non-constant fields of each instruction */
+      cmp = insn_field_cmp (insn->words, (*cur_insn_ptr)->insn->words);
+      if (cmp < 0)
+	break;
+      else if (cmp > 0)
+	continue;
+
+      /* duplicate keys, report problem */
+      switch (duplicate_action)
+	{
+	case report_duplicate_insns:
+	  /* It would appear that we have two instructions with the
+	     same constant field values across all words and bits.
+	     This error can also occure when insn_field_cmp() is
+	     failing to differentiate between two instructions that
+	     differ only in their conditional fields. */
+	  warning (insn->line,
+		   "Two instructions with identical constant fields\n");
+	  error ((*cur_insn_ptr)->insn->line,
+		 "Location of duplicate instruction\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);
+	}
+
+    }
+  
+  /* 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,
+	    model_entry *model)
+{
+  insn_entry *insn;
+  gen_list *entry = ZALLOC (gen_list);
+  entry->table = ZALLOC (gen_entry);
+  entry->table->top = entry;
+  entry->model = model;
+  entry->isa = isa;
+  for (insn = isa->insns; insn != NULL; insn = insn->next)
+    {
+      if (model == NULL
+	  || insn->processors == NULL
+	  || filter_is_member (insn->processors, model->name))
+	{
+	  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;
+      model_entry *model;
+      filter *processors;
+      if (options.model_filter != NULL)
+	processors = options.model_filter;
+      else
+	processors = isa->model->processors;
+      for (model = isa->model->models;
+	   model != NULL;
+	   model = model->next)
+	{
+	  if (filter_is_member (processors, model->name))
+	    {
+	      *last = make_table (isa, rules, model);
+	      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 */
+
+  /* check the instructions for some constant value in at least one of
+     the bit fields */
+  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_invalid:
+	  ASSERT (0);
+	  break;
+	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.  The first time through the
+                 value is saved, the second time through (if the
+                 values differ) it is marked as useful. */
+	      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:
+	      if (filter_is_member (rule->constant_field_names,
+				    bit->field->val_string))
+		/* a string field forced to constant? */
+		is_useless = 0;
+	      else if (rule->search == decode_find_constants)
+		/* the string field isn't constant */
+		return 1;
+	      break;
+	    }
+	}
+    }
+
+  /* Given only one constant value has been found, check through all
+     the instructions to see if at least one conditional makes it
+     usefull */
+  if (value >= 0 && is_useless)
+    {
+      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_invalid:
+	      ASSERT (0);
+	      break;
+	    case insn_field_wild:
+	    case insn_field_reserved:
+	    case insn_field_int:
+	      /* already processed */
+	      break;
+	    case insn_field_string:
+	      switch (rule->search)
+		{
+		case decode_find_strings:
+		case decode_find_constants:
+		  /* already processed */
+		  break;
+		case decode_find_mixed:
+		  /* string field with conditions.  If this condition
+                     eliminates the value then the compare is useful */
+		  if (bit->field->conditions != NULL)
+		    {
+		      insn_field_cond *condition;
+		      int shift = bit->field->last - bit_nr;
+		      for (condition = bit->field->conditions;
+			   condition != NULL;
+			   condition = condition->next)
+			{
+			  switch (condition->type)
+			    {
+			    case insn_field_cond_value:
+			      switch (condition->test)
+				{
+				case insn_field_cond_ne:
+				  if (((condition->value >> shift) & 1)
+				      == (unsigned) value)
+				    /* conditional field excludes the
+                                       current value */
+				    is_useless = 0;
+				  break;
+				case insn_field_cond_eq:
+				  if (((condition->value >> shift) & 1)
+				      != (unsigned) value)
+				    /* conditional field requires the
+                                       current value */
+				    is_useless = 0;
+				  break;
+				}
+			      break;
+			    case insn_field_cond_field:
+			      /* are these handled separatly? */
+			      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 (options.trace.insn_expansion)
+	{
+	  print_gen_entry_path (table->opcode_rule->line, table, notify);
+	  notify (NULL, ": insert %d - %s.%s%s\n",
+		  opcode_nr,
+		  instruction->format_name,
+		  instruction->name,
+		  (table->opcode_rule->with_duplicates ? " (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->last,
+			   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 precluded
+                       (by a conditional) in some way */
+		    int is_precluded;
+		    insn_field_cond *condition;
+		    for (condition = field->conditions, is_precluded = 0;
+			 condition != NULL && !is_precluded;
+			 condition = condition->next)
+		      {
+			switch (condition->type)
+			  {
+			  case insn_field_cond_value:
+			    {
+			      int value = sub_val (condition->value, field->last,
+						   first_pos, last_pos);
+			      switch (condition->test)
+				{
+				case insn_field_cond_ne:
+				  if (value == val)
+				    is_precluded = 1;
+				  break;
+				case insn_field_cond_eq:
+				  if (value != val)
+				    is_precluded = 1;
+				  break;
+				}
+			      break;
+			    }
+			  case insn_field_cond_field:
+			    {
+			      int value;
+			      opcode_bits *bit;
+			      gen_entry *t;
+			      /* Try to find a value for the
+                                 conditional by looking back through
+                                 the previously defined bits for one
+                                 that covers the designated
+                                 conditional field */
+			      for (bit = bits;
+				   bit != NULL;
+				   bit = bit->next)
+				{
+				  if (bit->field->word_nr == condition->field->word_nr
+				      && bit->first <= condition->field->first
+				      && bit->last >= condition->field->last)
+				    {
+				      /* the bit field fully specified
+					 the conditional field's value */
+				      value = sub_val (bit->value, bit->last,
+						       condition->field->first,
+						       condition->field->last);
+				    }
+				}
+			      /* Try to find a value by looking
+                                 through this and previous tables */
+			      if (bit == NULL)
+				{
+				  for (t = table;
+				       t->parent != NULL;
+				       t = t->parent)
+				    {
+				      if (t->parent->opcode->word_nr == condition->field->word_nr
+					  && t->parent->opcode->first <= condition->field->first
+					  && t->parent->opcode->last >= condition->field->last)
+					{
+					  /* the table entry fully
+                                             specified the condition
+                                             field's value */
+					  /* extract the field's value
+                                             from the opcode */
+					  value = sub_val (t->opcode_nr, t->parent->opcode->last,
+							   condition->field->first, condition->field->last);
+					  /* this is a requirement of
+                                             a conditonal field
+                                             refering to another field */
+					  ASSERT ((condition->field->first - condition->field->last)
+						  == (first_pos - last_pos));
+printf ("value=%d, opcode_nr=%d, last=%d, [%d..%d]\n",
+	value, t->opcode_nr, t->parent->opcode->last, condition->field->first, condition->field->last);
+					}
+				    }
+				}
+			      if (bit == NULL && t == NULL)
+				error (instruction->line,
+				       "Conditional `%s' of field `%s' isn't expanded",
+				       condition->string, field->val_string);
+			      switch (condition->test)
+				{
+				case insn_field_cond_ne:
+				  if (value == val)
+				    is_precluded = 1;
+				  break;
+				case insn_field_cond_eq:
+				  if (value != val)
+				    is_precluded = 1;
+				  break;
+				}
+			      break;
+			    }
+			  }
+		      }
+		    if (!is_precluded)
+		      {
+			/* 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->model != NULL
+	  && opcode_rule->model_names != NULL
+	  && !filter_is_member (opcode_rule->model_names,
+				table->top->model->name))
+	{
+	  /* 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;
+    }
+
+  /* report the rule being used to expand the instructions */
+  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);
+    }
+
+  /* expand the raw instructions according to the opcode */
+  {
+    insn_list *entry;
+    for (entry = table->insns; entry != NULL; entry = entry->next)
+      {
+	if (options.trace.insn_expansion)
+	  {
+	    print_gen_entry_path (table->opcode_rule->line, table, notify);
+	    notify (NULL, ": expand - %s.%s\n",
+		    entry->insn->format_name,
+		    entry->insn->name);
+	  }
+	gen_entry_insert_expanding (table, entry->insn);
+      }
+  }
+
+  /* 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