sim/igen/gen-icache.c - binutils-gdb - Git at Google

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

    Copyright 2002-2021 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 <stdlib.h>

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


 static void
 print_icache_function_header (lf *file,
 			      const char *basename,
 			      const char *format_name,
 			      opcode_bits *expanded_bits,
 			      int is_function_definition,
 			      int nr_prefetched_words)
 {
   lf_printf (file, "\n");
   lf_print__function_type_function (file, print_icache_function_type,
 				    "EXTERN_ICACHE", " ");
   print_function_name (file,
 		       basename, format_name, NULL,
 		       expanded_bits, function_name_prefix_icache);
   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");
 }


 void
 print_icache_declaration (lf *file,
 			  insn_entry * insn,
 			  opcode_bits *expanded_bits,
 			  insn_opcodes *opcodes, int nr_prefetched_words)
 {
   print_icache_function_header (file,
 				insn->name,
 				insn->format_name,
 				expanded_bits,
 				0 /* is not function definition */ ,
 				nr_prefetched_words);
 }


 static void
 print_icache_extraction (lf *file,
 			 const char *format_name,
 			 cache_entry_type cache_type,
 			 const char *entry_name,
 			 const char *entry_type,
 			 const char *entry_expression,
 			 char *single_insn_field,
 			 line_ref *line,
 			 insn_field_entry *cur_field,
 			 opcode_bits *expanded_bits,
 			 icache_decl_type what_to_declare,
 			 icache_body_type what_to_do)
 {
   const char *expression;
   opcode_bits *bits;
   char *reason;
   ASSERT (format_name != NULL);
   ASSERT (entry_name != NULL);

   /* figure out exactly what should be going on here */
   switch (cache_type)
     {
     case scratch_value:
       if ((what_to_do & put_values_in_icache)
 	  || what_to_do == do_not_use_icache)
 	{
 	  reason = "scratch";
 	  what_to_do = do_not_use_icache;
 	}
       else
 	return;
       break;
     case compute_value:
       if ((what_to_do & get_values_from_icache)
 	  || what_to_do == do_not_use_icache)
 	{
 	  reason = "compute";
 	  what_to_do = do_not_use_icache;
 	}
       else
 	return;
       break;
     case cache_value:
       if ((what_to_declare != undef_variables)
 	  || !(what_to_do & put_values_in_icache))
 	{
 	  reason = "cache";
 	  what_to_declare = ((what_to_do & put_values_in_icache)
 			     ? declare_variables : what_to_declare);
 	}
       else
 	return;
       break;
     default:
       abort ();			/* Bad switch.  */
     }

   /* For the type, default to a simple unsigned */
   if (entry_type == NULL || strlen (entry_type) == 0)
     entry_type = "unsigned";

   /* look through the set of expanded sub fields to see if this field
      has been given a constant value */
   for (bits = expanded_bits; bits != NULL; bits = bits->next)
     {
       if (bits->field == cur_field)
 	break;
     }

   /* Define a storage area for the cache element */
   switch (what_to_declare)
     {
     case undef_variables:
       /* We've finished with the #define value - destory it */
       lf_indent_suppress (file);
       lf_printf (file, "#undef %s\n", entry_name);
       return;
     case define_variables:
       /* Using direct access for this entry, clear any prior
          definition, then define it */
       lf_indent_suppress (file);
       lf_printf (file, "#undef %s\n", entry_name);
       /* Don't type cast pointer types! */
       lf_indent_suppress (file);
       if (strchr (entry_type, '*') != NULL)
 	lf_printf (file, "#define %s (", entry_name);
       else
 	lf_printf (file, "#define %s ((%s) ", entry_name, entry_type);
       break;
     case declare_variables:
       /* using variables to define the value */
       if (line != NULL)
 	lf_print__line_ref (file, line);
       lf_printf (file, "%s const %s UNUSED = ", entry_type, entry_name);
       break;
     }


   /* define a value for that storage area as determined by what is in
      the cache */
   if (bits != NULL
       && single_insn_field != NULL
       && strcmp (entry_name, single_insn_field) == 0
       && strcmp (entry_name, cur_field->val_string) == 0
       && ((bits->opcode->is_boolean && bits->value == 0)
 	  || (!bits->opcode->is_boolean)))
     {
       /* The cache rule is specifying what to do with a simple
          instruction field.

          Because of instruction expansion, the field is either a
          constant value or equal to the specified constant (boolean
          comparison). (The latter indicated by bits->value == 0).

          The case of a field not being equal to the specified boolean
          value is handled later. */
       expression = "constant field";
       ASSERT (bits->field == cur_field);
       if (bits->opcode->is_boolean)
 	{
 	  ASSERT (bits->value == 0);
 	  lf_printf (file, "%d", bits->opcode->boolean_constant);
 	}
       else if (bits->opcode->last < bits->field->last)
 	{
 	  lf_printf (file, "%d",
 		     bits->value << (bits->field->last - bits->opcode->last));
 	}
       else
 	{
 	  lf_printf (file, "%d", bits->value);
 	}
     }
   else if (bits != NULL
 	   && single_insn_field != NULL
 	   && strncmp (entry_name,
 		       single_insn_field,
 		       strlen (single_insn_field)) == 0
 	   && strncmp (entry_name + strlen (single_insn_field),
 		       "_is_",
 		       strlen ("_is_")) == 0
 	   && ((bits->opcode->is_boolean
 		&& ((unsigned)
 		    atol (entry_name + strlen (single_insn_field) +
 			  strlen ("_is_")) == bits->opcode->boolean_constant))
 	       || (!bits->opcode->is_boolean)))
     {
       /* The cache rule defines an entry for the comparison between a
          single instruction field and a constant.  The value of the
          comparison in someway matches that of the opcode field that
          was made constant through expansion. */
       expression = "constant compare";
       if (bits->opcode->is_boolean)
 	{
 	  lf_printf (file, "%d /* %s == %d */",
 		     bits->value == 0,
 		     single_insn_field, bits->opcode->boolean_constant);
 	}
       else if (bits->opcode->last < bits->field->last)
 	{
 	  lf_printf (file, "%d /* %s == %d */",
 		     (atol
 		      (entry_name + strlen (single_insn_field) +
 		       strlen ("_is_")) ==
 		      (bits->
 		       value << (bits->field->last - bits->opcode->last))),
 		     single_insn_field,
 		     (bits->
 		      value << (bits->field->last - bits->opcode->last)));
 	}
       else
 	{
 	  lf_printf (file, "%d /* %s == %d */",
 		     (atol
 		      (entry_name + strlen (single_insn_field) +
 		       strlen ("_is_")) == bits->value), single_insn_field,
 		     bits->value);
 	}
     }
   else
     {
       /* put the field in the local variable, possibly also enter it
          into the cache */
       expression = "extraction";
       /* handle the cache */
       if ((what_to_do & get_values_from_icache)
 	  || (what_to_do & put_values_in_icache))
 	{
 	  lf_printf (file, "cache_entry->crack.%s.%s",
 		     format_name, entry_name);
 	  if (what_to_do & put_values_in_icache)	/* also put it in the cache? */
 	    {
 	      lf_printf (file, " = ");
 	    }
 	}
       if ((what_to_do & put_values_in_icache)
 	  || what_to_do == do_not_use_icache)
 	{
 	  if (cur_field != NULL)
 	    {
 	      if (entry_expression != NULL && strlen (entry_expression) > 0)
 		error (line,
 		       "Instruction field entry with nonempty expression\n");
 	      if (cur_field->first == 0
 		  && cur_field->last == options.insn_bit_size - 1)
 		lf_printf (file, "(instruction_%d)", cur_field->word_nr);
 	      else if (cur_field->last == options.insn_bit_size - 1)
 		lf_printf (file, "MASKED%d (instruction_%d, %d, %d)",
 			   options.insn_bit_size,
 			   cur_field->word_nr,
 			   i2target (options.hi_bit_nr, cur_field->first),
 			   i2target (options.hi_bit_nr, cur_field->last));
 	      else
 		lf_printf (file, "EXTRACTED%d (instruction_%d, %d, %d)",
 			   options.insn_bit_size,
 			   cur_field->word_nr,
 			   i2target (options.hi_bit_nr, cur_field->first),
 			   i2target (options.hi_bit_nr, cur_field->last));
 	    }
 	  else
 	    {
 	      lf_printf (file, "%s", entry_expression);
 	    }
 	}
     }

   switch (what_to_declare)
     {
     case define_variables:
       lf_printf (file, ")");
       break;
     case undef_variables:
       break;
     case declare_variables:
       lf_printf (file, ";");
       break;
     }

   ASSERT (reason != NULL && expression != NULL);
   lf_printf (file, " /* %s - %s */\n", reason, expression);
 }


 void
 print_icache_body (lf *file,
 		   insn_entry * instruction,
 		   opcode_bits *expanded_bits,
 		   cache_entry *cache_rules,
 		   icache_decl_type what_to_declare,
 		   icache_body_type what_to_do, int nr_prefetched_words)
 {
   /* extract instruction fields */
   lf_printf (file, "/* Extraction: %s\n", instruction->name);
   lf_printf (file, "     ");
   switch (what_to_declare)
     {
     case define_variables:
       lf_printf (file, "#define");
       break;
     case declare_variables:
       lf_printf (file, "declare");
       break;
     case undef_variables:
       lf_printf (file, "#undef");
       break;
     }
   lf_printf (file, " ");
   switch (what_to_do)
     {
     case get_values_from_icache:
       lf_printf (file, "get-values-from-icache");
       break;
     case put_values_in_icache:
       lf_printf (file, "put-values-in-icache");
       break;
     case both_values_and_icache:
       lf_printf (file, "get-values-from-icache|put-values-in-icache");
       break;
     case do_not_use_icache:
       lf_printf (file, "do-not-use-icache");
       break;
     }
   lf_printf (file, "\n     ");
   print_insn_words (file, instruction);
   lf_printf (file, " */\n");

   /* pass zero - fetch from memory any missing instructions.

      Some of the instructions will have already been fetched (in the
      instruction array), others will still need fetching. */
   switch (what_to_do)
     {
     case get_values_from_icache:
       break;
     case put_values_in_icache:
     case both_values_and_icache:
     case do_not_use_icache:
       {
 	int word_nr;
 	switch (what_to_declare)
 	  {
 	  case undef_variables:
 	    break;
 	  case define_variables:
 	  case declare_variables:
 	    for (word_nr = nr_prefetched_words;
 		 word_nr < instruction->nr_words; word_nr++)
 	      {
 		/* FIXME - should be using print_icache_extraction? */
 		lf_printf (file,
 			   "%sinstruction_word instruction_%d UNUSED = ",
 			   options.module.global.prefix.l, word_nr);
 		lf_printf (file, "IMEM%d_IMMED (cia, %d)",
 			   options.insn_bit_size, word_nr);
 		lf_printf (file, ";\n");
 	      }
 	  }
       }
     }

   /* if putting the instruction words in the cache, define references
      for them */
   if (options.gen.insn_in_icache)
     {
       /* FIXME: is the instruction_word type correct? */
       print_icache_extraction (file, instruction->format_name, cache_value, "insn",	/* name */
 			       "instruction_word",	/* type */
 			       "instruction",	/* expression */
 			       NULL,	/* origin */
 			       NULL,	/* line */
 			       NULL, NULL, what_to_declare, what_to_do);
     }
   lf_printf (file, "\n");

   /* pass one - process instruction fields.

      If there is no cache rule, the default is to enter the field into
      the cache */
   {
     insn_word_entry *word;
     for (word = instruction->words; word != NULL; word = word->next)
       {
 	insn_field_entry *cur_field;
 	for (cur_field = word->first;
 	     cur_field->first < options.insn_bit_size;
 	     cur_field = cur_field->next)
 	  {
 	    /* Always expand named fields (even if constant), so
 	       references are valid.  */
 	    if (cur_field->type == insn_field_string)
 	      {
 		cache_entry *cache_rule;
 		cache_entry_type value_type = cache_value;
 		line_ref *value_line = instruction->line;
 		/* check the cache table to see if it contains a rule
 		   overriding the default cache action for an
 		   instruction field */
 		for (cache_rule = cache_rules;
 		     cache_rule != NULL; cache_rule = cache_rule->next)
 		  {
 		    if (filter_is_subset (instruction->field_names,
 					  cache_rule->original_fields)
 			&& strcmp (cache_rule->name,
 				   cur_field->val_string) == 0)
 		      {
 			value_type = cache_rule->entry_type;
 			value_line = cache_rule->line;
 			if (value_type == compute_value)
 			  {
 			    options.warning (cache_rule->line,
 					     "instruction field of type `compute' changed to `cache'\n");
 			    cache_rule->entry_type = cache_value;
 			  }
 			break;
 		      }
 		  }
 		/* Define an entry for the field within the
 		   instruction */
 		print_icache_extraction (file, instruction->format_name, value_type, cur_field->val_string,	/* name */
 					 NULL,	/* type */
 					 NULL,	/* expression */
 					 cur_field->val_string,	/* insn field */
 					 value_line,
 					 cur_field,
 					 expanded_bits,
 					 what_to_declare, what_to_do);
 	      }
 	  }
       }
   }

   /* pass two - any cache fields not processed above */
   {
     cache_entry *cache_rule;
     for (cache_rule = cache_rules;
 	 cache_rule != NULL; cache_rule = cache_rule->next)
       {
 	if (filter_is_subset (instruction->field_names,
 			      cache_rule->original_fields)
 	    && !filter_is_member (instruction->field_names, cache_rule->name))
 	  {
 	    char *single_field =
 	      filter_next (cache_rule->original_fields, "");
 	    if (filter_next (cache_rule->original_fields, single_field) !=
 		NULL)
 	      single_field = NULL;
 	    print_icache_extraction (file, instruction->format_name, cache_rule->entry_type, cache_rule->name, cache_rule->type, cache_rule->expression, single_field, cache_rule->line, NULL,	/* cur_field */
 				     expanded_bits,
 				     what_to_declare, what_to_do);
 	  }
       }
   }

   lf_print__internal_ref (file);
 }


 typedef struct _form_fields form_fields;
 struct _form_fields
 {
   char *name;
   filter *fields;
   form_fields *next;
 };

 static form_fields *
 insn_table_cache_fields (insn_table *isa)
 {
   form_fields *forms = NULL;
   insn_entry *insn;
   for (insn = isa->insns; insn != NULL; insn = insn->next)
     {
       form_fields **form = &forms;
       while (1)
 	{
 	  if (*form == NULL)
 	    {
 	      /* new format name, add it */
 	      form_fields *new_form = ZALLOC (form_fields);
 	      new_form->name = insn->format_name;
 	      filter_add (&new_form->fields, insn->field_names);
 	      *form = new_form;
 	      break;
 	    }
 	  else if (strcmp ((*form)->name, insn->format_name) == 0)
 	    {
 	      /* already present, add field names to the existing list */
 	      filter_add (&(*form)->fields, insn->field_names);
 	      break;
 	    }
 	  form = &(*form)->next;
 	}
     }
   return forms;
 }


 extern void
 print_icache_struct (lf *file, insn_table *isa, cache_entry *cache_rules)
 {
   /* Create a list of all the different instruction formats with their
      corresponding field names. */
   form_fields *formats = insn_table_cache_fields (isa);

   lf_printf (file, "\n");
   lf_printf (file, "#define WITH_%sIDECODE_CACHE_SIZE %d\n",
 	     options.module.global.prefix.u,
 	     (options.gen.icache ? options.gen.icache_size : 0));
   lf_printf (file, "\n");

   /* create an instruction cache if being used */
   if (options.gen.icache)
     {
       lf_printf (file, "typedef struct _%sidecode_cache {\n",
 		 options.module.global.prefix.l);
       lf_indent (file, +2);
       {
 	form_fields *format;
 	lf_printf (file, "unsigned_word address;\n");
 	lf_printf (file, "void *semantic;\n");
 	lf_printf (file, "union {\n");
 	lf_indent (file, +2);
 	for (format = formats; format != NULL; format = format->next)
 	  {
 	    lf_printf (file, "struct {\n");
 	    lf_indent (file, +2);
 	    {
 	      cache_entry *cache_rule;
 	      char *field;
 	      /* space for any instruction words */
 	      if (options.gen.insn_in_icache)
 		lf_printf (file, "instruction_word insn[%d];\n",
 			   isa->max_nr_words);
 	      /* define an entry for any applicable cache rules */
 	      for (cache_rule = cache_rules;
 		   cache_rule != NULL; cache_rule = cache_rule->next)
 		{
 		  /* nb - sort of correct - should really check against
 		     individual instructions */
 		  if (filter_is_subset
 		      (format->fields, cache_rule->original_fields))
 		    {
 		      char *memb;
 		      lf_printf (file, "%s %s;",
 				 (cache_rule->type == NULL
 				  ? "unsigned"
 				  : cache_rule->type), cache_rule->name);
 		      lf_printf (file, " /*");
 		      for (memb =
 			   filter_next (cache_rule->original_fields, "");
 			   memb != NULL;
 			   memb =
 			   filter_next (cache_rule->original_fields, memb))
 			{
 			  lf_printf (file, " %s", memb);
 			}
 		      lf_printf (file, " */\n");
 		    }
 		}
 	      /* define an entry for any fields not covered by a cache rule */
 	      for (field = filter_next (format->fields, "");
 		   field != NULL; field = filter_next (format->fields, field))
 		{
 		  cache_entry *cache_rule;
 		  int found_rule = 0;
 		  for (cache_rule = cache_rules;
 		       cache_rule != NULL; cache_rule = cache_rule->next)
 		    {
 		      if (strcmp (cache_rule->name, field) == 0)
 			{
 			  found_rule = 1;
 			  break;
 			}
 		    }
 		  if (!found_rule)
 		    lf_printf (file, "unsigned %s; /* default */\n", field);
 		}
 	    }
 	    lf_indent (file, -2);
 	    lf_printf (file, "} %s;\n", format->name);
 	  }
 	lf_indent (file, -2);
 	lf_printf (file, "} crack;\n");
       }
       lf_indent (file, -2);
       lf_printf (file, "} %sidecode_cache;\n",
 		 options.module.global.prefix.l);
     }
   else
     {
       /* alernativly, since no cache, emit a dummy definition for
          idecode_cache so that code refering to the type can still compile */
       lf_printf (file, "typedef void %sidecode_cache;\n",
 		 options.module.global.prefix.l);
     }
   lf_printf (file, "\n");
 }


 static void
 print_icache_function (lf *file,
 		       insn_entry * instruction,
 		       opcode_bits *expanded_bits,
 		       insn_opcodes *opcodes,
 		       cache_entry *cache_rules, int nr_prefetched_words)
 {
   int indent;

   /* generate code to enter decoded instruction into the icache */
   lf_printf (file, "\n");
   lf_print__function_type_function (file, print_icache_function_type,
 				    "EXTERN_ICACHE", "\n");
   indent = print_function_name (file,
 				instruction->name,
 				instruction->format_name,
 				NULL,
 				expanded_bits, function_name_prefix_icache);
   indent += lf_printf (file, " ");
   lf_indent (file, +indent);
   lf_printf (file, "(");
   print_icache_function_formal (file, nr_prefetched_words);
   lf_printf (file, ")\n");
   lf_indent (file, -indent);

   /* function header */
   lf_printf (file, "{\n");
   lf_indent (file, +2);

   print_my_defines (file,
 		    instruction->name,
 		    instruction->format_name, expanded_bits);
   print_itrace (file, instruction, 1 /*putting-value-in-cache */ );

   print_idecode_validate (file, instruction, opcodes);

   lf_printf (file, "\n");
   lf_printf (file, "{\n");
   lf_indent (file, +2);
   if (options.gen.semantic_icache)
     lf_printf (file, "unsigned_word nia;\n");
   print_icache_body (file,
 		     instruction,
 		     expanded_bits,
 		     cache_rules,
 		     (options.gen.direct_access
 		      ? define_variables
 		      : declare_variables),
 		     (options.gen.semantic_icache
 		      ? both_values_and_icache
 		      : put_values_in_icache), nr_prefetched_words);

   lf_printf (file, "\n");
   lf_printf (file, "cache_entry->address = cia;\n");
   lf_printf (file, "cache_entry->semantic = ");
   print_function_name (file,
 		       instruction->name,
 		       instruction->format_name,
 		       NULL, expanded_bits, function_name_prefix_semantics);
   lf_printf (file, ";\n");
   lf_printf (file, "\n");

   if (options.gen.semantic_icache)
     {
       lf_printf (file, "/* semantic routine */\n");
       print_semantic_body (file, instruction, expanded_bits, opcodes);
       lf_printf (file, "return nia;\n");
     }

   if (!options.gen.semantic_icache)
     {
       lf_printf (file, "/* return the function proper */\n");
       lf_printf (file, "return ");
       print_function_name (file,
 			   instruction->name,
 			   instruction->format_name,
 			   NULL,
 			   expanded_bits, function_name_prefix_semantics);
       lf_printf (file, ";\n");
     }

   if (options.gen.direct_access)
     {
       print_icache_body (file,
 			 instruction,
 			 expanded_bits,
 			 cache_rules,
 			 undef_variables,
 			 (options.gen.semantic_icache
 			  ? both_values_and_icache
 			  : put_values_in_icache), nr_prefetched_words);
     }

   lf_indent (file, -2);
   lf_printf (file, "}\n");
   lf_indent (file, -2);
   lf_printf (file, "}\n");
 }


 void
 print_icache_definition (lf *file,
 			 insn_entry * insn,
 			 opcode_bits *expanded_bits,
 			 insn_opcodes *opcodes,
 			 cache_entry *cache_rules, int nr_prefetched_words)
 {
   print_icache_function (file,
 			 insn,
 			 expanded_bits,
 			 opcodes, cache_rules, nr_prefetched_words);
 }


 void
 print_icache_internal_function_declaration (lf *file,
 					    function_entry * function,
 					    void *data)
 {
   ASSERT (options.gen.icache);
   if (function->is_internal)
     {
       lf_printf (file, "\n");
       lf_print__function_type_function (file, print_icache_function_type,
 					"INLINE_ICACHE", "\n");
       print_function_name (file,
 			   function->name,
 			   NULL, NULL, NULL, function_name_prefix_icache);
       lf_printf (file, "\n(");
       print_icache_function_formal (file, 0);
       lf_printf (file, ");\n");
     }
 }


 void
 print_icache_internal_function_definition (lf *file,
 					   function_entry * function,
 					   void *data)
 {
   ASSERT (options.gen.icache);
   if (function->is_internal)
     {
       lf_printf (file, "\n");
       lf_print__function_type_function (file, print_icache_function_type,
 					"INLINE_ICACHE", "\n");
       print_function_name (file,
 			   function->name,
 			   NULL, NULL, NULL, function_name_prefix_icache);
       lf_printf (file, "\n(");
       print_icache_function_formal (file, 0);
       lf_printf (file, ")\n");
       lf_printf (file, "{\n");
       lf_indent (file, +2);
       lf_printf (file, "/* semantic routine */\n");
       if (options.gen.semantic_icache)
 	{
 	  lf_print__line_ref (file, function->code->line);
 	  table_print_code (file, function->code);
 	  lf_printf (file,
 		     "error (\"Internal function must longjump\\n\");\n");
 	  lf_printf (file, "return 0;\n");
 	}
       else
 	{
 	  lf_printf (file, "return ");
 	  print_function_name (file,
 			       function->name,
 			       NULL,
 			       NULL, NULL, function_name_prefix_semantics);
 	  lf_printf (file, ";\n");
 	}

       lf_print__internal_ref (file);
       lf_indent (file, -2);
       lf_printf (file, "}\n");
     }
 }
	/* The IGEN simulator generator for GDB, the GNU Debugger.

	Copyright 2002-2021 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 <stdlib.h>

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



	static void
	print_icache_function_header (lf *file,
	const char *basename,
	const char *format_name,
	opcode_bits *expanded_bits,
	int is_function_definition,
	int nr_prefetched_words)
	{
	lf_printf (file, "\n");
	lf_print__function_type_function (file, print_icache_function_type,
	"EXTERN_ICACHE", " ");
	print_function_name (file,
	basename, format_name, NULL,
	expanded_bits, function_name_prefix_icache);
	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");
	}


	void
	print_icache_declaration (lf *file,
	insn_entry * insn,
	opcode_bits *expanded_bits,
	insn_opcodes *opcodes, int nr_prefetched_words)
	{
	print_icache_function_header (file,
	insn->name,
	insn->format_name,
	expanded_bits,
	0 /* is not function definition */ ,
	nr_prefetched_words);
	}



	static void
	print_icache_extraction (lf *file,
	const char *format_name,
	cache_entry_type cache_type,
	const char *entry_name,
	const char *entry_type,
	const char *entry_expression,
	char *single_insn_field,
	line_ref *line,
	insn_field_entry *cur_field,
	opcode_bits *expanded_bits,
	icache_decl_type what_to_declare,
	icache_body_type what_to_do)
	{
	const char *expression;
	opcode_bits *bits;
	char *reason;
	ASSERT (format_name != NULL);
	ASSERT (entry_name != NULL);

	/* figure out exactly what should be going on here */
	switch (cache_type)
	{
	case scratch_value:
	if ((what_to_do & put_values_in_icache)
	\|\| what_to_do == do_not_use_icache)
	{
	reason = "scratch";
	what_to_do = do_not_use_icache;
	}
	else
	return;
	break;
	case compute_value:
	if ((what_to_do & get_values_from_icache)
	\|\| what_to_do == do_not_use_icache)
	{
	reason = "compute";
	what_to_do = do_not_use_icache;
	}
	else
	return;
	break;
	case cache_value:
	if ((what_to_declare != undef_variables)
	\|\| !(what_to_do & put_values_in_icache))
	{
	reason = "cache";
	what_to_declare = ((what_to_do & put_values_in_icache)
	? declare_variables : what_to_declare);
	}
	else
	return;
	break;
	default:
	abort (); /* Bad switch. */
	}

	/* For the type, default to a simple unsigned */
	if (entry_type == NULL \|\| strlen (entry_type) == 0)
	entry_type = "unsigned";

	/* look through the set of expanded sub fields to see if this field
	has been given a constant value */
	for (bits = expanded_bits; bits != NULL; bits = bits->next)
	{
	if (bits->field == cur_field)
	break;
	}

	/* Define a storage area for the cache element */
	switch (what_to_declare)
	{
	case undef_variables:
	/* We've finished with the #define value - destory it */
	lf_indent_suppress (file);
	lf_printf (file, "#undef %s\n", entry_name);
	return;
	case define_variables:
	/* Using direct access for this entry, clear any prior
	definition, then define it */
	lf_indent_suppress (file);
	lf_printf (file, "#undef %s\n", entry_name);
	/* Don't type cast pointer types! */
	lf_indent_suppress (file);
	if (strchr (entry_type, '*') != NULL)
	lf_printf (file, "#define %s (", entry_name);
	else
	lf_printf (file, "#define %s ((%s) ", entry_name, entry_type);
	break;
	case declare_variables:
	/* using variables to define the value */
	if (line != NULL)
	lf_print__line_ref (file, line);
	lf_printf (file, "%s const %s UNUSED = ", entry_type, entry_name);
	break;
	}


	/* define a value for that storage area as determined by what is in
	the cache */
	if (bits != NULL
	&& single_insn_field != NULL
	&& strcmp (entry_name, single_insn_field) == 0
	&& strcmp (entry_name, cur_field->val_string) == 0
	&& ((bits->opcode->is_boolean && bits->value == 0)
	\|\| (!bits->opcode->is_boolean)))
	{
	/* The cache rule is specifying what to do with a simple
	instruction field.

	Because of instruction expansion, the field is either a
	constant value or equal to the specified constant (boolean
	comparison). (The latter indicated by bits->value == 0).

	The case of a field not being equal to the specified boolean
	value is handled later. */
	expression = "constant field";
	ASSERT (bits->field == cur_field);
	if (bits->opcode->is_boolean)
	{
	ASSERT (bits->value == 0);
	lf_printf (file, "%d", bits->opcode->boolean_constant);
	}
	else if (bits->opcode->last < bits->field->last)
	{
	lf_printf (file, "%d",
	bits->value << (bits->field->last - bits->opcode->last));
	}
	else
	{
	lf_printf (file, "%d", bits->value);
	}
	}
	else if (bits != NULL
	&& single_insn_field != NULL
	&& strncmp (entry_name,
	single_insn_field,
	strlen (single_insn_field)) == 0
	&& strncmp (entry_name + strlen (single_insn_field),
	"_is_",
	strlen ("_is_")) == 0
	&& ((bits->opcode->is_boolean
	&& ((unsigned)
	atol (entry_name + strlen (single_insn_field) +
	strlen ("_is_")) == bits->opcode->boolean_constant))
	\|\| (!bits->opcode->is_boolean)))
	{
	/* The cache rule defines an entry for the comparison between a
	single instruction field and a constant. The value of the
	comparison in someway matches that of the opcode field that
	was made constant through expansion. */
	expression = "constant compare";
	if (bits->opcode->is_boolean)
	{
	lf_printf (file, "%d /* %s == %d */",
	bits->value == 0,
	single_insn_field, bits->opcode->boolean_constant);
	}
	else if (bits->opcode->last < bits->field->last)
	{
	lf_printf (file, "%d /* %s == %d */",
	(atol
	(entry_name + strlen (single_insn_field) +
	strlen ("_is_")) ==
	(bits->
	value << (bits->field->last - bits->opcode->last))),
	single_insn_field,
	(bits->
	value << (bits->field->last - bits->opcode->last)));
	}
	else
	{
	lf_printf (file, "%d /* %s == %d */",
	(atol
	(entry_name + strlen (single_insn_field) +
	strlen ("_is_")) == bits->value), single_insn_field,
	bits->value);
	}
	}
	else
	{
	/* put the field in the local variable, possibly also enter it
	into the cache */
	expression = "extraction";
	/* handle the cache */
	if ((what_to_do & get_values_from_icache)
	\|\| (what_to_do & put_values_in_icache))
	{
	lf_printf (file, "cache_entry->crack.%s.%s",
	format_name, entry_name);
	if (what_to_do & put_values_in_icache) /* also put it in the cache? */
	{
	lf_printf (file, " = ");
	}
	}
	if ((what_to_do & put_values_in_icache)
	\|\| what_to_do == do_not_use_icache)
	{
	if (cur_field != NULL)
	{
	if (entry_expression != NULL && strlen (entry_expression) > 0)
	error (line,
	"Instruction field entry with nonempty expression\n");
	if (cur_field->first == 0
	&& cur_field->last == options.insn_bit_size - 1)
	lf_printf (file, "(instruction_%d)", cur_field->word_nr);
	else if (cur_field->last == options.insn_bit_size - 1)
	lf_printf (file, "MASKED%d (instruction_%d, %d, %d)",
	options.insn_bit_size,
	cur_field->word_nr,
	i2target (options.hi_bit_nr, cur_field->first),
	i2target (options.hi_bit_nr, cur_field->last));
	else
	lf_printf (file, "EXTRACTED%d (instruction_%d, %d, %d)",
	options.insn_bit_size,
	cur_field->word_nr,
	i2target (options.hi_bit_nr, cur_field->first),
	i2target (options.hi_bit_nr, cur_field->last));
	}
	else
	{
	lf_printf (file, "%s", entry_expression);
	}
	}
	}

	switch (what_to_declare)
	{
	case define_variables:
	lf_printf (file, ")");
	break;
	case undef_variables:
	break;
	case declare_variables:
	lf_printf (file, ";");
	break;
	}

	ASSERT (reason != NULL && expression != NULL);
	lf_printf (file, " /* %s - %s */\n", reason, expression);
	}


	void
	print_icache_body (lf *file,
	insn_entry * instruction,
	opcode_bits *expanded_bits,
	cache_entry *cache_rules,
	icache_decl_type what_to_declare,
	icache_body_type what_to_do, int nr_prefetched_words)
	{
	/* extract instruction fields */
	lf_printf (file, "/* Extraction: %s\n", instruction->name);
	lf_printf (file, " ");
	switch (what_to_declare)
	{
	case define_variables:
	lf_printf (file, "#define");
	break;
	case declare_variables:
	lf_printf (file, "declare");
	break;
	case undef_variables:
	lf_printf (file, "#undef");
	break;
	}
	lf_printf (file, " ");
	switch (what_to_do)
	{
	case get_values_from_icache:
	lf_printf (file, "get-values-from-icache");
	break;
	case put_values_in_icache:
	lf_printf (file, "put-values-in-icache");
	break;
	case both_values_and_icache:
	lf_printf (file, "get-values-from-icache\|put-values-in-icache");
	break;
	case do_not_use_icache:
	lf_printf (file, "do-not-use-icache");
	break;
	}
	lf_printf (file, "\n ");
	print_insn_words (file, instruction);
	lf_printf (file, " */\n");

	/* pass zero - fetch from memory any missing instructions.

	Some of the instructions will have already been fetched (in the
	instruction array), others will still need fetching. */
	switch (what_to_do)
	{
	case get_values_from_icache:
	break;
	case put_values_in_icache:
	case both_values_and_icache:
	case do_not_use_icache:
	{
	int word_nr;
	switch (what_to_declare)
	{
	case undef_variables:
	break;
	case define_variables:
	case declare_variables:
	for (word_nr = nr_prefetched_words;
	word_nr < instruction->nr_words; word_nr++)
	{
	/* FIXME - should be using print_icache_extraction? */
	lf_printf (file,
	"%sinstruction_word instruction_%d UNUSED = ",
	options.module.global.prefix.l, word_nr);
	lf_printf (file, "IMEM%d_IMMED (cia, %d)",
	options.insn_bit_size, word_nr);
	lf_printf (file, ";\n");
	}
	}
	}
	}

	/* if putting the instruction words in the cache, define references
	for them */
	if (options.gen.insn_in_icache)
	{
	/* FIXME: is the instruction_word type correct? */
	print_icache_extraction (file, instruction->format_name, cache_value, "insn", /* name */
	"instruction_word", /* type */
	"instruction", /* expression */
	NULL, /* origin */
	NULL, /* line */
	NULL, NULL, what_to_declare, what_to_do);
	}
	lf_printf (file, "\n");

	/* pass one - process instruction fields.

	If there is no cache rule, the default is to enter the field into
	the cache */
	{
	insn_word_entry *word;
	for (word = instruction->words; word != NULL; word = word->next)
	{
	insn_field_entry *cur_field;
	for (cur_field = word->first;
	cur_field->first < options.insn_bit_size;
	cur_field = cur_field->next)
	{
	/* Always expand named fields (even if constant), so
	references are valid. */
	if (cur_field->type == insn_field_string)
	{
	cache_entry *cache_rule;
	cache_entry_type value_type = cache_value;
	line_ref *value_line = instruction->line;
	/* check the cache table to see if it contains a rule
	overriding the default cache action for an
	instruction field */
	for (cache_rule = cache_rules;
	cache_rule != NULL; cache_rule = cache_rule->next)
	{
	if (filter_is_subset (instruction->field_names,
	cache_rule->original_fields)
	&& strcmp (cache_rule->name,
	cur_field->val_string) == 0)
	{
	value_type = cache_rule->entry_type;
	value_line = cache_rule->line;
	if (value_type == compute_value)
	{
	options.warning (cache_rule->line,
	"instruction field of type `compute' changed to `cache'\n");
	cache_rule->entry_type = cache_value;
	}
	break;
	}
	}
	/* Define an entry for the field within the
	instruction */
	print_icache_extraction (file, instruction->format_name, value_type, cur_field->val_string, /* name */
	NULL, /* type */
	NULL, /* expression */
	cur_field->val_string, /* insn field */
	value_line,
	cur_field,
	expanded_bits,
	what_to_declare, what_to_do);
	}
	}
	}
	}

	/* pass two - any cache fields not processed above */
	{
	cache_entry *cache_rule;
	for (cache_rule = cache_rules;
	cache_rule != NULL; cache_rule = cache_rule->next)
	{
	if (filter_is_subset (instruction->field_names,
	cache_rule->original_fields)
	&& !filter_is_member (instruction->field_names, cache_rule->name))
	{
	char *single_field =
	filter_next (cache_rule->original_fields, "");
	if (filter_next (cache_rule->original_fields, single_field) !=
	NULL)
	single_field = NULL;
	print_icache_extraction (file, instruction->format_name, cache_rule->entry_type, cache_rule->name, cache_rule->type, cache_rule->expression, single_field, cache_rule->line, NULL, /* cur_field */
	expanded_bits,
	what_to_declare, what_to_do);
	}
	}
	}

	lf_print__internal_ref (file);
	}



	typedef struct _form_fields form_fields;
	struct _form_fields
	{
	char *name;
	filter *fields;
	form_fields *next;
	};

	static form_fields *
	insn_table_cache_fields (insn_table *isa)
	{
	form_fields *forms = NULL;
	insn_entry *insn;
	for (insn = isa->insns; insn != NULL; insn = insn->next)
	{
	form_fields **form = &forms;
	while (1)
	{
	if (*form == NULL)
	{
	/* new format name, add it */
	form_fields *new_form = ZALLOC (form_fields);
	new_form->name = insn->format_name;
	filter_add (&new_form->fields, insn->field_names);
	*form = new_form;
	break;
	}
	else if (strcmp ((*form)->name, insn->format_name) == 0)
	{
	/* already present, add field names to the existing list */
	filter_add (&(*form)->fields, insn->field_names);
	break;
	}
	form = &(*form)->next;
	}
	}
	return forms;
	}



	extern void
	print_icache_struct (lf file, insn_table isa, cache_entry *cache_rules)
	{
	/* Create a list of all the different instruction formats with their
	corresponding field names. */
	form_fields *formats = insn_table_cache_fields (isa);

	lf_printf (file, "\n");
	lf_printf (file, "#define WITH_%sIDECODE_CACHE_SIZE %d\n",
	options.module.global.prefix.u,
	(options.gen.icache ? options.gen.icache_size : 0));
	lf_printf (file, "\n");

	/* create an instruction cache if being used */
	if (options.gen.icache)
	{
	lf_printf (file, "typedef struct _%sidecode_cache {\n",
	options.module.global.prefix.l);
	lf_indent (file, +2);
	{
	form_fields *format;
	lf_printf (file, "unsigned_word address;\n");
	lf_printf (file, "void *semantic;\n");
	lf_printf (file, "union {\n");
	lf_indent (file, +2);
	for (format = formats; format != NULL; format = format->next)
	{
	lf_printf (file, "struct {\n");
	lf_indent (file, +2);
	{
	cache_entry *cache_rule;
	char *field;
	/* space for any instruction words */
	if (options.gen.insn_in_icache)
	lf_printf (file, "instruction_word insn[%d];\n",
	isa->max_nr_words);
	/* define an entry for any applicable cache rules */
	for (cache_rule = cache_rules;
	cache_rule != NULL; cache_rule = cache_rule->next)
	{
	/* nb - sort of correct - should really check against
	individual instructions */
	if (filter_is_subset
	(format->fields, cache_rule->original_fields))
	{
	char *memb;
	lf_printf (file, "%s %s;",
	(cache_rule->type == NULL
	? "unsigned"
	: cache_rule->type), cache_rule->name);
	lf_printf (file, " /*");
	for (memb =
	filter_next (cache_rule->original_fields, "");
	memb != NULL;
	memb =
	filter_next (cache_rule->original_fields, memb))
	{
	lf_printf (file, " %s", memb);
	}
	lf_printf (file, " */\n");
	}
	}
	/* define an entry for any fields not covered by a cache rule */
	for (field = filter_next (format->fields, "");
	field != NULL; field = filter_next (format->fields, field))
	{
	cache_entry *cache_rule;
	int found_rule = 0;
	for (cache_rule = cache_rules;
	cache_rule != NULL; cache_rule = cache_rule->next)
	{
	if (strcmp (cache_rule->name, field) == 0)
	{
	found_rule = 1;
	break;
	}
	}
	if (!found_rule)
	lf_printf (file, "unsigned %s; /* default */\n", field);
	}
	}
	lf_indent (file, -2);
	lf_printf (file, "} %s;\n", format->name);
	}
	lf_indent (file, -2);
	lf_printf (file, "} crack;\n");
	}
	lf_indent (file, -2);
	lf_printf (file, "} %sidecode_cache;\n",
	options.module.global.prefix.l);
	}
	else
	{
	/* alernativly, since no cache, emit a dummy definition for
	idecode_cache so that code refering to the type can still compile */
	lf_printf (file, "typedef void %sidecode_cache;\n",
	options.module.global.prefix.l);
	}
	lf_printf (file, "\n");
	}



	static void
	print_icache_function (lf *file,
	insn_entry * instruction,
	opcode_bits *expanded_bits,
	insn_opcodes *opcodes,
	cache_entry *cache_rules, int nr_prefetched_words)
	{
	int indent;

	/* generate code to enter decoded instruction into the icache */
	lf_printf (file, "\n");
	lf_print__function_type_function (file, print_icache_function_type,
	"EXTERN_ICACHE", "\n");
	indent = print_function_name (file,
	instruction->name,
	instruction->format_name,
	NULL,
	expanded_bits, function_name_prefix_icache);
	indent += lf_printf (file, " ");
	lf_indent (file, +indent);
	lf_printf (file, "(");
	print_icache_function_formal (file, nr_prefetched_words);
	lf_printf (file, ")\n");
	lf_indent (file, -indent);

	/* function header */
	lf_printf (file, "{\n");
	lf_indent (file, +2);

	print_my_defines (file,
	instruction->name,
	instruction->format_name, expanded_bits);
	print_itrace (file, instruction, 1 /putting-value-in-cache / );

	print_idecode_validate (file, instruction, opcodes);

	lf_printf (file, "\n");
	lf_printf (file, "{\n");
	lf_indent (file, +2);
	if (options.gen.semantic_icache)
	lf_printf (file, "unsigned_word nia;\n");
	print_icache_body (file,
	instruction,
	expanded_bits,
	cache_rules,
	(options.gen.direct_access
	? define_variables
	: declare_variables),
	(options.gen.semantic_icache
	? both_values_and_icache
	: put_values_in_icache), nr_prefetched_words);

	lf_printf (file, "\n");
	lf_printf (file, "cache_entry->address = cia;\n");
	lf_printf (file, "cache_entry->semantic = ");
	print_function_name (file,
	instruction->name,
	instruction->format_name,
	NULL, expanded_bits, function_name_prefix_semantics);
	lf_printf (file, ";\n");
	lf_printf (file, "\n");

	if (options.gen.semantic_icache)
	{
	lf_printf (file, "/* semantic routine */\n");
	print_semantic_body (file, instruction, expanded_bits, opcodes);
	lf_printf (file, "return nia;\n");
	}

	if (!options.gen.semantic_icache)
	{
	lf_printf (file, "/* return the function proper */\n");
	lf_printf (file, "return ");
	print_function_name (file,
	instruction->name,
	instruction->format_name,
	NULL,
	expanded_bits, function_name_prefix_semantics);
	lf_printf (file, ";\n");
	}

	if (options.gen.direct_access)
	{
	print_icache_body (file,
	instruction,
	expanded_bits,
	cache_rules,
	undef_variables,
	(options.gen.semantic_icache
	? both_values_and_icache
	: put_values_in_icache), nr_prefetched_words);
	}

	lf_indent (file, -2);
	lf_printf (file, "}\n");
	lf_indent (file, -2);
	lf_printf (file, "}\n");
	}


	void
	print_icache_definition (lf *file,
	insn_entry * insn,
	opcode_bits *expanded_bits,
	insn_opcodes *opcodes,
	cache_entry *cache_rules, int nr_prefetched_words)
	{
	print_icache_function (file,
	insn,
	expanded_bits,
	opcodes, cache_rules, nr_prefetched_words);
	}



	void
	print_icache_internal_function_declaration (lf *file,
	function_entry * function,
	void *data)
	{
	ASSERT (options.gen.icache);
	if (function->is_internal)
	{
	lf_printf (file, "\n");
	lf_print__function_type_function (file, print_icache_function_type,
	"INLINE_ICACHE", "\n");
	print_function_name (file,
	function->name,
	NULL, NULL, NULL, function_name_prefix_icache);
	lf_printf (file, "\n(");
	print_icache_function_formal (file, 0);
	lf_printf (file, ");\n");
	}
	}


	void
	print_icache_internal_function_definition (lf *file,
	function_entry * function,
	void *data)
	{
	ASSERT (options.gen.icache);
	if (function->is_internal)
	{
	lf_printf (file, "\n");
	lf_print__function_type_function (file, print_icache_function_type,
	"INLINE_ICACHE", "\n");
	print_function_name (file,
	function->name,
	NULL, NULL, NULL, function_name_prefix_icache);
	lf_printf (file, "\n(");
	print_icache_function_formal (file, 0);
	lf_printf (file, ")\n");
	lf_printf (file, "{\n");
	lf_indent (file, +2);
	lf_printf (file, "/* semantic routine */\n");
	if (options.gen.semantic_icache)
	{
	lf_print__line_ref (file, function->code->line);
	table_print_code (file, function->code);
	lf_printf (file,
	"error (\"Internal function must longjump\\n\");\n");
	lf_printf (file, "return 0;\n");
	}
	else
	{
	lf_printf (file, "return ");
	print_function_name (file,
	function->name,
	NULL,
	NULL, NULL, function_name_prefix_semantics);
	lf_printf (file, ";\n");
	}

	lf_print__internal_ref (file);
	lf_indent (file, -2);
	lf_printf (file, "}\n");
	}
	}