gen-idecode.c

这个是LINUX下的GDB调度工具的源码

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

   Copyright 2002 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 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"

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



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



static void
print_idecode_table (lf *file, 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, 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, gen_entry *entry, int depth, void *data)
{
  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, 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, 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,
			      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, 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, 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, gen_entry *table, const char *result);

static void
print_idecode_switch_start (lf *file, 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, 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 */
      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;