xref: /src/external/gpl3/gdb.old/dist/sim/igen/gen-idecode.c

/* The IGEN simulator generator for GDB, the GNU Debugger.

   Copyright 2002-2024 Free Software Foundation, Inc.

   Contributed by Andrew Cagney.

   This file is part of GDB.

   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 3 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, see <http://www.gnu.org/licenses/>.  */


#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"

#include "gen-idecode.h"
#include "gen-icache.h"
#include "gen-semantics.h"



static void
lf_print_opcodes (lf *file, const gen_entry *table)
{
  if (table !=NULL)
    {
      while (1)
	{
	  ASSERT (table->opcode != NULL);
	  lf_printf (file, "_%d_%d",
		     table->opcode->first, table->opcode->last);
	  if (table->parent == NULL)
	    break;
	  lf_printf (file, "__%d", table->opcode_nr);
	  table = table->parent;
	}
    }
}




static void
print_idecode_ifetch (lf *file,
		      int previous_nr_prefetched_words,
		      int current_nr_prefetched_words)
{
  int word_nr;
  for (word_nr = previous_nr_prefetched_words;
       word_nr < current_nr_prefetched_words; word_nr++)
    {
      lf_printf (file,
		 "instruction_word instruction_%d = IMEM%d_IMMED (cia, %d);\n",
		 word_nr, options.insn_bit_size, word_nr);

    }
}



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


static void
lf_print_table_name (lf *file, const gen_entry *table)
{
  lf_printf (file, "idecode_table");
  lf_print_opcodes (file, table);
}



static void
print_idecode_table (lf *file, const gen_entry *entry, const char *result)
{
  lf_printf (file, "/* prime the search */\n");
  lf_printf (file, "idecode_table_entry *table = ");
  lf_print_table_name (file, entry);
  lf_printf (file, ";\n");
  lf_printf (file, "int opcode = EXTRACTED%d (instruction, %d, %d);\n",
	     options.insn_bit_size,
	     i2target (options.hi_bit_nr, entry->opcode->first),
	     i2target (options.hi_bit_nr, entry->opcode->last));
  lf_printf (file, "idecode_table_entry *table_entry = table + opcode;\n");

  lf_printf (file, "\n");
  lf_printf (file, "/* iterate until a leaf */\n");
  lf_printf (file, "while (1) {\n");
  lf_printf (file, "  signed shift = table_entry->shift;\n");
  lf_printf (file, "if (shift == function_entry) break;\n");
  lf_printf (file, "  if (shift >= 0) {\n");
  lf_printf (file, "    table = ((idecode_table_entry*)\n");
  lf_printf (file, "             table_entry->function_or_table);\n");
  lf_printf (file, "    opcode = ((instruction & table_entry->mask)\n");
  lf_printf (file, "              >> shift);\n");
  lf_printf (file, "    table_entry = table + opcode;\n");
  lf_printf (file, "  }\n");
  lf_printf (file, "  else {\n");
  lf_printf (file, "    /* must be a boolean */\n");
  lf_printf (file, "    ASSERT(table_entry->shift == boolean_entry);\n");
  lf_printf (file, "    opcode = ((instruction & table_entry->mask)\n");
  lf_printf (file, "              != table_entry->value);\n");
  lf_printf (file, "    table = ((idecode_table_entry*)\n");
  lf_printf (file, "             table_entry->function_or_table);\n");
  lf_printf (file, "    table_entry = table + opcode;\n");
  lf_printf (file, "  }\n");
  lf_printf (file, "}\n");

  lf_printf (file, "\n");
  lf_printf (file, "/* call the leaf code */\n");
  if (options.gen.code == generate_jumps)
    {
      lf_printf (file, "goto *table_entry->function_or_table;\n");
    }
  else
    {
      lf_printf (file, "%s ", result);
      if (options.gen.icache)
	{
	  lf_printf (file,
		     "(((idecode_icache*)table_entry->function_or_table)\n");
	  lf_printf (file, "  (");
	  print_icache_function_actual (file, 1);
	  lf_printf (file, "));\n");
	}
      else
	{
	  lf_printf (file,
		     "((idecode_semantic*)table_entry->function_or_table)\n");
	  lf_printf (file, "  (");
	  print_semantic_function_actual (file, 1);
	  lf_printf (file, ");\n");
	}
    }
}


static void
print_idecode_table_start (lf *file,
			   const gen_entry *table, int depth, void *data)
{
  ASSERT (depth == 0);
  /* start of the table */
  if (table->opcode_rule->gen == array_gen)
    {
      lf_printf (file, "\n");
      lf_printf (file, "static idecode_table_entry ");
      lf_print_table_name (file, table);
      lf_printf (file, "[] = {\n");
    }
}

static void
print_idecode_table_leaf (lf *file,
			  const gen_entry *entry, int depth, void *data)
{
  const gen_entry *master_entry;
  ASSERT (entry->parent != NULL);
  ASSERT (depth == 0);
  if (entry->combined_parent == NULL)
    master_entry = entry;
  else
    master_entry = entry->combined_parent;

  /* add an entry to the table */
  if (entry->parent->opcode_rule->gen == array_gen)
    {
      lf_printf (file, "  /*%d*/ { ", entry->opcode_nr);
      if (entry->opcode == NULL)
	{
	  ASSERT (entry->nr_insns == 1);
	  /* table leaf entry */
	  lf_printf (file, "function_entry, 0, 0, ");
	  if (options.gen.code == generate_jumps)
	    {
	      lf_printf (file, "&&");
	    }
	  print_function_name (file,
			       entry->insns->insn->name,
			       entry->insns->insn->format_name,
			       NULL,
			       master_entry->expanded_bits,
			       (options.gen.icache
				? function_name_prefix_icache
				: function_name_prefix_semantics));
	}
      else if (entry->opcode_rule->gen == switch_gen
	       || entry->opcode_rule->gen == goto_switch_gen
	       || entry->opcode_rule->gen == padded_switch_gen)
	{
	  /* table calling switch statement */
	  lf_printf (file, "function_entry, 0, 0, ");
	  if (options.gen.code == generate_jumps)
	    {
	      lf_printf (file, "&&");
	    }
	  lf_print_table_name (file, entry);
	}
      else if (entry->opcode->is_boolean)
	{
	  /* table `calling' boolean table */
	  lf_printf (file, "boolean_entry, ");
	  lf_printf (file, "MASK32(%d, %d), ",
		     i2target (options.hi_bit_nr, entry->opcode->first),
		     i2target (options.hi_bit_nr, entry->opcode->last));
	  lf_printf (file, "INSERTED32(%d, %d, %d), ",
		     entry->opcode->boolean_constant,
		     i2target (options.hi_bit_nr, entry->opcode->first),
		     i2target (options.hi_bit_nr, entry->opcode->last));
	  lf_print_table_name (file, entry);
	}
      else
	{
	  /* table `calling' another table */
	  lf_printf (file, "%d, ",
		     options.insn_bit_size - entry->opcode->last - 1);
	  lf_printf (file, "MASK%d(%d,%d), ", options.insn_bit_size,
		     i2target (options.hi_bit_nr, entry->opcode->first),
		     i2target (options.hi_bit_nr, entry->opcode->last));
	  lf_printf (file, "0, ");
	  lf_print_table_name (file, entry);
	}
      lf_printf (file, " },\n");
    }
}

static void
print_idecode_table_end (lf *file,
			 const gen_entry *table, int depth, void *data)
{
  ASSERT (depth == 0);
  if (table->opcode_rule->gen == array_gen)
    {
      lf_printf (file, "};\n");
    }
}

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


static void
print_goto_switch_name (lf *file, const gen_entry *entry)
{
  lf_printf (file, "case_");
  if (entry->opcode == NULL)
    {
      print_function_name (file,
			   entry->insns->insn->name,
			   entry->insns->insn->format_name,
			   NULL,
			   entry->expanded_bits,
			   (options.gen.icache
			    ? function_name_prefix_icache
			    : function_name_prefix_semantics));
    }
  else
    {
      lf_print_table_name (file, entry);
    }
}

static void
print_goto_switch_table_leaf (lf *file,
			      const gen_entry *entry, int depth, void *data)
{
  ASSERT (entry->parent != NULL);
  ASSERT (depth == 0);
  ASSERT (entry->parent->opcode_rule->gen == goto_switch_gen);
  ASSERT (entry->parent->opcode);

  lf_printf (file, "/* %d */ &&", entry->opcode_nr);
  if (entry->combined_parent != NULL)
    print_goto_switch_name (file, entry->combined_parent);
  else
    print_goto_switch_name (file, entry);
  lf_printf (file, ",\n");
}

static void
print_goto_switch_break (lf *file, const gen_entry *entry)
{
  lf_printf (file, "goto break_");
  lf_print_table_name (file, entry->parent);
  lf_printf (file, ";\n");
}


static void
print_goto_switch_table (lf *file, const gen_entry *table)
{
  lf_printf (file, "const static void *");
  lf_print_table_name (file, table);
  lf_printf (file, "[] = {\n");
  lf_indent (file, +2);
  gen_entry_traverse_tree (file, table, 0, NULL /*start */ ,
			   print_goto_switch_table_leaf, NULL /*end */ ,
			   NULL /*data */ );
  lf_indent (file, -2);
  lf_printf (file, "};\n");
}


void print_idecode_switch
  (lf *file, const gen_entry *table, const char *result);

static void
print_idecode_switch_start (lf *file,
			    const gen_entry *table, int depth, void *data)
{
  /* const char *result = data; */
  ASSERT (depth == 0);
  ASSERT (table->opcode_rule->gen == switch_gen
	  || table->opcode_rule->gen == goto_switch_gen
	  || table->opcode_rule->gen == padded_switch_gen);

  if (table->opcode->is_boolean
      || table->opcode_rule->gen == switch_gen
      || table->opcode_rule->gen == padded_switch_gen)
    {
      lf_printf (file, "switch (EXTRACTED%d (instruction_%d, %d, %d))\n",
		 options.insn_bit_size,
		 table->opcode_rule->word_nr,
		 i2target (options.hi_bit_nr, table->opcode->first),
		 i2target (options.hi_bit_nr, table->opcode->last));
      lf_indent (file, +2);
      lf_printf (file, "{\n");
    }
  else if (table->opcode_rule->gen == goto_switch_gen)
    {
      if (table->parent != NULL
	  && (table->parent->opcode_rule->gen == switch_gen
	      || table->parent->opcode_rule->gen == goto_switch_gen
	      || table->parent->opcode_rule->gen == padded_switch_gen))
	{
	  lf_printf (file, "{\n");
	  lf_indent (file, +2);
	}
      print_goto_switch_table (file, table);
      lf_printf (file, "ASSERT (EXTRACTED%d (instruction_%d, %d, %d)\n",
		 options.insn_bit_size,
		 table->opcode->word_nr,
		 i2target (options.hi_bit_nr, table->opcode->first),
		 i2target (options.hi_bit_nr, table->opcode->last));
      lf_printf (file, "        < (sizeof (");
      lf_print_table_name (file, table);
      lf_printf (file, ") / sizeof(void*)));\n");
      lf_printf (file, "goto *");
      lf_print_table_name (file, table);
      lf_printf (file, "[EXTRACTED%d (instruction_%d, %d, %d)];\n",
		 options.insn_bit_size,
		 table->opcode->word_nr,
		 i2target (options.hi_bit_nr, table->opcode->first),
		 i2target (options.hi_bit_nr, table->opcode->last));
    }
  else
    {
      ASSERT ("bad switch" == NULL);
    }
}


static void
print_idecode_switch_leaf (lf *file,
			   const gen_entry *entry, int depth, void *data)
{
  const char *result = data;
  ASSERT (entry->parent != NULL);
  ASSERT (depth == 0);
  ASSERT (entry->parent->opcode_rule->gen == switch_gen
	  || entry->parent->opcode_rule->gen == goto_switch_gen
	  || entry->parent->opcode_rule->gen == padded_switch_gen);
  ASSERT (entry->parent->opcode);

  /* skip over any instructions combined into another entry */
  if (entry->combined_parent != NULL)
    return;

  if (entry->parent->opcode->is_boolean && entry->opcode_nr == 0)
    {
      /* case: boolean false target */
      lf_printf (file, "case %d:\n", entry->parent->opcode->boolean_constant);
    }
  else if (entry->parent->opcode->is_boolean && entry->opcode_nr != 0)
    {
      /* case: boolean true case */
      lf_printf (file, "default:\n");
    }
  else if (entry->parent->opcode_rule->gen == switch_gen
	   || entry->parent->opcode_rule->gen == padded_switch_gen)
    {
      /* case: <opcode-nr> - switch */
      const gen_entry *cob;
      for (cob = entry; cob != NULL; cob = cob->combined_next)
	lf_printf (file, "case %d:\n", cob->opcode_nr);
    }
  else if (entry->parent->opcode_rule->gen == goto_switch_gen)
    {
      /* case: <opcode-nr> - goto-switch */
      print_goto_switch_name (file, entry);
      lf_printf (file, ":\n");
    }
  else
    {
      ERROR ("bad switch");
    }
  lf_printf (file, "  {\n");
  lf_indent (file, +4);
  {
    if (entry->opcode == NULL)
      {
	/* switch calling leaf */
	ASSERT (entry->nr_insns == 1);
	print_idecode_ifetch (file, entry->nr_prefetched_words,
			      entry->insns->semantic->nr_prefetched_words);
	switch (options.gen.code)
	  {
	  case generate_jumps:
	    lf_printf (file, "goto ");
	    break;
	  case generate_calls:
	    lf_printf (file, "%s", result);
	    break;
	  }
	print_function_name (file,
			     entry->insns->insn->name,
			     entry->insns->insn->format_name,
			     NULL,
			     entry->expanded_bits,
			     (options.gen.icache
			      ? function_name_prefix_icache
			      : function_name_prefix_semantics));
	if (options.gen.code == generate_calls)
	  {
	    lf_printf (file, " (");
	    print_semantic_function_actual (file,
					    entry->insns->semantic->
					    nr_prefetched_words);
	    lf_printf (file, ")");
	  }
	lf_printf (file, ";\n");
      }
    else if (entry->opcode_rule->gen == switch_gen
	     || entry->opcode_rule->gen == goto_switch_gen
	     || entry->opcode_rule->gen == padded_switch_gen)
      {
	/* switch calling switch */
	lf_printf (file, "{\n");
	lf_indent (file, +2);
	print_idecode_ifetch (file, entry->parent->nr_prefetched_words,
			      entry->nr_prefetched_words);
	print_idecode_switch (file, entry, result);
	lf_indent (file, -2);
	lf_printf (file, "}\n");
      }
    else
      {
	/* switch looking up a table */
	lf_printf (file, "{\n");
	lf_indent (file, +2);
	print_idecode_ifetch (file, entry->parent->nr_prefetched_words,
			      entry->nr_prefetched_words);
	print_idecode_table (file, entry, result);
	lf_indent (file, -2);
	lf_printf (file, "}\n");
      }
    if (entry->parent->opcode->is_boolean
	|| entry->parent->opcode_rule->gen == switch_gen
	|| entry->parent->opcode_rule->gen == padded_switch_gen)
      {
	lf_printf (file, "break;\n");
      }
    else if (entry->parent->opcode_rule->gen == goto_switch_gen)
      {
	print_goto_switch_break (file, entry);
      }
    else
      {
	ERROR ("bad switch");
      }
  }
  lf_indent (file, -4);
  lf_printf (file, "  }\n");
}


static void
print_idecode_switch_illegal (lf *file, const char *result)
{
  lf_indent (file, +2);
  print_idecode_invalid (file, result, invalid_illegal);
  lf_printf (file, "break;\n");
  lf_indent (file, -2);
}

static void
print_idecode_switch_end (lf *file,
			  const gen_entry *table, int depth, void *data)
{
  const char *result = data;
  ASSERT (depth == 0);
  ASSERT (table->opcode_rule->gen == switch_gen
	  || table->opcode_rule->gen == goto_switch_gen
	  || table->opcode_rule->gen == padded_switch_gen);
  ASSERT (table->opcode);

  if (table->opcode->is_boolean)
    {
      lf_printf (file, "}\n");
      lf_indent (file, -2);
    }
  else if (table->opcode_rule->gen == switch_gen
	   || table->opcode_rule->gen == padded_switch_gen)
    {
      lf_printf (file, "default:\n");
      lf_indent (file, +2);
      if (table->nr_entries == table->opcode->nr_opcodes)
	{
	  print_sim_engine_abort (file,
				  "Internal error - bad switch generated");
	  lf_printf (file, "%sNULL_CIA;\n", result);
	  lf_printf (file, "break;\n");
	}
      else
	{
	  print_idecode_switch_illegal (file, result);
	}
      lf_indent (file, -2);
      lf_printf (file, "}\n");
      lf_indent (file, -2);
    }
  else if (table->opcode_rule->gen == goto_switch_gen)
    {
      lf_printf (file, "illegal_");
      lf_print_table_name (file, table);
      lf_printf (file, ":\n");
      print_idecode_invalid (file, result, invalid_illegal);
      lf_printf (file, "break_");
      lf_print_table_name (file, table);
      lf_printf (file, ":;\n");
      if (table->parent != NULL
	  && (table->parent->opcode_rule->gen == switch_gen
	      || table->parent->opcode_rule->gen == goto_switch_gen
	      || table->parent->opcode_rule->gen == padded_switch_gen))
	{
	  lf_indent (file, -2);
	  lf_printf (file, "}\n");
	}
    }
  else
    {
      ERROR ("bad switch");
    }
}


void
print_idecode_switch (lf *file, const gen_entry *table, const char *result)
{
  gen_entry_traverse_tree (file, table,
			   0,
			   print_idecode_switch_start,
			   print_idecode_switch_leaf,
			   print_idecode_switch_end, (void *) result);
}


static void
print_idecode_switch_function_header (lf *file,
				      const gen_entry *table,
				      int is_function_definition,
				      int nr_prefetched_words)
{
  lf_printf (file, "\n");
  if (options.gen.code == generate_calls)
    {
      lf_printf (file, "static ");
      if (options.gen.icache)
	{
	  lf_printf (file, "idecode_semantic *");
	}
      else
	{
	  lf_printf (file, "unsigned_word");
	}
      if (is_function_definition)
	{
	  lf_printf (file, "\n");
	}
      else
	{
	  lf_printf (file, " ");
	}
      lf_print_table_name (file, table);
      lf_printf (file, "\n(");
      print_icache_function_formal (file, nr_prefetched_words);
      lf_printf (file, ")");
      if (!is_function_definition)
	{
	  lf_printf (file, ";");
	}
      lf_printf (file, "\n");
    }
  if (options.gen.code == generate_jumps && is_function_definition)
    {
      lf_indent (file, -1);
      lf_print_table_name (file, table);
      lf_printf (file, ":\n");
      lf_indent (file, +1);
    }
}


static void
idecode_declare_if_switch (lf *file,
			   const gen_entry *table, int depth, void *data)
{
  if ((table->opcode_rule->gen == switch_gen || table->opcode_rule->gen == goto_switch_gen || table->opcode_rule->gen == padded_switch_gen) &&table->parent != NULL	/* don't declare the top one yet */
      && table->parent->opcode_rule->gen == array_gen)
    {
      print_idecode_switch_function_header (file,
					    table,
					    0 /*isnt function definition */ ,
					    0);
    }
}


static void
idecode_expand_if_switch (lf *file,
			  const gen_entry *table, int depth, void *data)
{
  if ((table->opcode_rule->gen == switch_gen || table->opcode_rule->gen == goto_switch_gen || table->opcode_rule->gen == padded_switch_gen) &&table->parent != NULL	/* don't expand the top one yet */
      && table->parent->opcode_rule->gen == array_gen)
    {
      print_idecode_switch_function_header (file,
					    table,
					    1 /*is function definition */ ,
					    0);
      if (options.gen.code == generate_calls)
	{
	  lf_printf (file, "{\n");
	  lf_indent (file, +2);
	}
      print_idecode_switch (file, table, "return");
      if (options.gen.code == generate_calls)
	{
	  lf_indent (file, -2);
	  lf_printf (file, "}\n");
	}
    }
}


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


void
print_idecode_lookups (lf *file,
		       const gen_entry *table,
		       cache_entry *cache_rules)
{
  int depth;

  /* output switch function declarations where needed by tables */
  gen_entry_traverse_tree (file, table, 1, idecode_declare_if_switch,	/* START */
			   NULL, NULL, NULL);

  /* output tables where needed */
  for (depth = gen_entry_depth (table); depth > 0; depth--)
    {
      gen_entry_traverse_tree (file, table,
			       1 - depth,
			       print_idecode_table_start,
			       print_idecode_table_leaf,
			       print_idecode_table_end, NULL);
    }

  /* output switch functions where needed */
  gen_entry_traverse_tree (file, table, 1, idecode_expand_if_switch,	/* START */
			   NULL, NULL, NULL);
}


void
print_idecode_body (lf *file, const gen_entry *table, const char *result)
{
  if (table->opcode_rule->gen == switch_gen
      || table->opcode_rule->gen == goto_switch_gen
      || table->opcode_rule->gen == padded_switch_gen)
    {
      print_idecode_switch (file, table, result);
    }
  else
    {
      print_idecode_table (file, table, result);
    }
}


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

/* Output code to do any final checks on the decoded instruction.
   This includes things like verifying any on decoded fields have the
   correct value and checking that (for floating point) floating point
   hardware isn't disabled */

void
print_idecode_validate (lf *file,
			const insn_entry *instruction,
			const insn_opcodes *opcode_paths)
{
  /* Validate: unchecked instruction fields

     If any constant fields in the instruction were not checked by the
     idecode tables, output code to check that they have the correct
     value here */
  {
    int nr_checks = 0;
    int word_nr;
    lf_printf (file, "\n");
    lf_indent_suppress (file);
    lf_printf (file, "#if defined (WITH_RESERVED_BITS)\n");
    lf_printf (file, "/* validate: ");
    print_insn_words (file, instruction);
    lf_printf (file, " */\n");
    for (word_nr = 0; word_nr < instruction->nr_words; word_nr++)
      {
	insn_uint check_mask = 0;
	insn_uint check_val = 0;
	insn_word_entry *word = instruction->word[word_nr];
	int bit_nr;

	/* form check_mask/check_val containing what needs to be checked
	   in the instruction */
	for (bit_nr = 0; bit_nr < options.insn_bit_size; bit_nr++)
	  {
	    insn_bit_entry *bit = word->bit[bit_nr];
	    insn_field_entry *field = bit->field;

	    /* Make space for the next bit */
	    check_mask <<= 1;
	    check_val <<= 1;

	    /* Only need to validate constant (and reserved)
	       bits. Skip any others */
	    if (field->type != insn_field_int
		&& field->type != insn_field_reserved
		/* Consider a named field equal to a value to be just as
		   constant as an integer field.  */
		&& (field->type != insn_field_string
		    || field->conditions == NULL
		    || field->conditions->test != insn_field_cond_eq
		    || field->conditions->type != insn_field_cond_value))
	      continue;

	    /* Look through the list of opcode paths that lead to this
	       instruction.  See if any have failed to check the
	       relevant bit */
	    if (opcode_paths != NULL)
	      {
		const insn_opcodes *entry;
		for (entry = opcode_paths; entry != NULL; entry = entry->next)
		  {
		    opcode_field *opcode;
		    for (opcode = entry->opcode;
			 opcode != NULL; opcode = opcode->parent)
		      {
			if (opcode->word_nr == word_nr
			    && opcode->first <= bit_nr
			    && opcode->last >= bit_nr)
			  /* we've decoded on this bit */
			  break;
		      }
		    if (opcode == NULL)
		      /* the bit wasn't decoded on */
		      break;
		  }
		if (entry == NULL)
		  /* all the opcode paths decoded on BIT_NR, no need
		     to check it */
		  continue;
	      }

	    check_mask |= 1;
	    check_val |= bit->value;
	  }

	/* if any bits not checked by opcode tables, output code to check them */
	if (check_mask)
	  {
	    if (nr_checks == 0)
	      {
		lf_printf (file, "if (WITH_RESERVED_BITS)\n");
		lf_printf (file, "  {\n");
		lf_indent (file, +4);
	      }
	    nr_checks++;
	    if (options.insn_bit_size > 32)
	      {
		lf_printf (file, "if ((instruction_%d\n", word_nr);
		lf_printf (file, "     & UNSIGNED64 (0x%08lx%08lx))\n",
			   (unsigned long) (check_mask >> 32),
			   (unsigned long) (check_mask));
		lf_printf (file, "    != UNSIGNED64 (0x%08lx%08lx))\n",
			   (unsigned long) (check_val >> 32),
			   (unsigned long) (check_val));
	      }
	    else
	      {
		lf_printf (file,
			   "if ((instruction_%d & 0x%08lx) != 0x%08lx)\n",
			   word_nr, (unsigned long) (check_mask),
			   (unsigned long) (check_val));
	      }
	    lf_indent (file, +2);
	    print_idecode_invalid (file, "return", invalid_illegal);
	    lf_indent (file, -2);
	  }
      }
    if (nr_checks > 0)
      {
	lf_indent (file, -4);
	lf_printf (file, "  }\n");
      }
    lf_indent_suppress (file);
    lf_printf (file, "#endif\n");
  }

  /* Validate: Floating Point hardware

     If the simulator is being built with out floating point hardware
     (different to it being disabled in the MSR) then floating point
     instructions are invalid */
  {
    if (filter_is_member (instruction->flags, "f"))
      {
	lf_printf (file, "\n");
	lf_indent_suppress (file);
	lf_printf (file, "#if defined(CURRENT_FLOATING_POINT)\n");
	lf_printf (file, "/* Validate: FP hardware exists */\n");
	lf_printf (file,
		   "if (CURRENT_FLOATING_POINT != HARD_FLOATING_POINT) {\n");
	lf_indent (file, +2);
	print_idecode_invalid (file, "return", invalid_illegal);
	lf_indent (file, -2);
	lf_printf (file, "}\n");
	lf_indent_suppress (file);
	lf_printf (file, "#endif\n");
      }
  }

  /* Validate: Floating Point available

     If floating point is not available, we enter a floating point
     unavailable interrupt into the cache instead of the instruction
     proper.

     The PowerPC spec requires a CSI after MSR[FP] is changed and when
     ever a CSI occures we flush the instruction cache. */

  {
    if (filter_is_member (instruction->flags, "f"))
      {
	lf_printf (file, "\n");
	lf_indent_suppress (file);
	lf_printf (file, "#if defined(IS_FP_AVAILABLE)\n");
	lf_printf (file, "/* Validate: FP available according to cpu */\n");
	lf_printf (file, "if (!IS_FP_AVAILABLE) {\n");
	lf_indent (file, +2);
	print_idecode_invalid (file, "return", invalid_fp_unavailable);
	lf_indent (file, -2);
	lf_printf (file, "}\n");
	lf_indent_suppress (file);
	lf_printf (file, "#endif\n");
      }
  }

  /* Validate: Validate Instruction in correct slot

     Some architectures place restrictions on the slot that an
     instruction can be issued in */

  {
    if (filter_is_member (instruction->options, "s")
	|| options.gen.slot_verification)
      {
	lf_printf (file, "\n");
	lf_indent_suppress (file);
	lf_printf (file, "#if defined(IS_WRONG_SLOT)\n");
	lf_printf (file,
		   "/* Validate: Instruction issued in correct slot */\n");
	lf_printf (file, "if (IS_WRONG_SLOT) {\n");
	lf_indent (file, +2);
	print_idecode_invalid (file, "return", invalid_wrong_slot);
	lf_indent (file, -2);
	lf_printf (file, "}\n");
	lf_indent_suppress (file);
	lf_printf (file, "#endif\n");
      }
  }

}


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


void
print_idecode_issue_function_header (lf *file,
				     const char *processor,
				     function_decl_type decl_type,
				     int nr_prefetched_words)
{
  int indent;
  lf_printf (file, "\n");
  switch (decl_type)
    {
    case is_function_declaration:
      lf_print__function_type_function (file, print_semantic_function_type,
					"INLINE_IDECODE", " ");
      break;
    case is_function_definition:
      lf_print__function_type_function (file, print_semantic_function_type,
					"INLINE_IDECODE", "\n");
      break;
    case is_function_variable:
      if (lf_get_file_type (file) == lf_is_h)
	lf_printf (file, "extern ");
      print_semantic_function_type (file);
      lf_printf (file, " (*");
      break;
    }
  indent = print_function_name (file,
				"issue",
				NULL,
				processor,
				NULL, function_name_prefix_idecode);
  switch (decl_type)
    {
    case is_function_definition:
      indent += lf_printf (file, " (");
      break;
    case is_function_declaration:
      lf_putstr (file, "\n(");
      indent = 1;
      break;
    case is_function_variable:
      lf_putstr (file, ")\n(");
      indent = 1;
      break;
    }
  lf_indent (file, +indent);
  print_semantic_function_formal (file, nr_prefetched_words);
  lf_putstr (file, ")");
  lf_indent (file, -indent);
  switch (decl_type)
    {
    case is_function_definition:
      lf_printf (file, "\n");
      break;
    case is_function_declaration:
    case is_function_variable:
      lf_putstr (file, ";\n");
      break;
    }
}



void
print_idecode_globals (lf *file)
{
  lf_printf (file, "enum {\n");
  lf_printf (file, "  /* greater or equal to zero => table */\n");
  lf_printf (file, "  function_entry = -1,\n");
  lf_printf (file, "  boolean_entry = -2,\n");
  lf_printf (file, "};\n");
  lf_printf (file, "\n");
  lf_printf (file, "typedef struct _idecode_table_entry {\n");
  lf_printf (file, "  int shift;\n");
  lf_printf (file, "  uint%d_t mask;\n", options.insn_bit_size);
  lf_printf (file, "  uint%d_t value;\n", options.insn_bit_size);
  lf_printf (file, "  void *function_or_table;\n");
  lf_printf (file, "} idecode_table_entry;\n");
}