writecode.c

这个是LINUX下的GDB调度工具的源码

/* generate instructions for Z8KSIM

   Copyright 1992, 1993, 2002 Free Software Foundation, Inc.

This file is part of Z8KSIM

Z8KSIM 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, or (at your option)
any later version.

Z8KSIM 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 Z8KZIM; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

/* This program generates the code which emulates each of the z8k
   instructions

   code goes into three files, tc-gen1.h, tc-gen2.h and tc-gen3.h.
   which file being made depends upon the options

   -1  tc-gen1.h contains the fully expanded code for some selected
       opcodes, (those in the quick.c list)

   -2   tc-gen2.h contains a list of pointers to functions, one for each
   opcode.  It points to functions in tc-gen3.h and tc-gen1.h
   depending upon quick.c

   -3   tc-gen3.h contains all the opcodes in unexpanded form.

   -b3   tc-genb3.h same as -3 but for long pointers

   */

/* steve chamberlain
   [e-mail] */

#include "config.h"

#include <ansidecl.h>
#include <stdio.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#else
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
#endif

#define NICENAMES

#define DEFINE_TABLE
#include "../opcodes/z8k-opc.h"

#define NOPS 500

struct opcode_value
{
  int n;
  struct opcode_value *next;
};

#define NICENAMES
int BIG;

static char *reg_names[] =
{"bad", "src", "dst", "aux_a", "aux_b", "aux_r", "aux_x"};

#define IS_DST(x) ((x & 0xf) == 2)
#define IS_SRC(x) ((x & 0xf)==1)
#define SIZE_ADDRESS (BIG ? 8 : 4)	/* number of nibbles in a ptr*/

static int file;

static int nibs = 0;

static char *current_size;
static char *current_name;
static char current_word0[40];
static char current_byte0[40];
static char current_byte1[40];
static int indent;
static char *p;
static char *d;

struct opcode_value *list[NOPS];

static opcode_entry_type *
lookup_inst (what)
     int what;
{
  static short *z8k_inv_list = NULL;
  const nr_z8k_inv_list_elements = 1 << 16;
  if (z8k_inv_list == NULL)
    {
      /* Initialize the list to 0xff == -1 */
      z8k_inv_list = calloc (nr_z8k_inv_list_elements, sizeof (short));
      memset (z8k_inv_list, 0xff, nr_z8k_inv_list_elements * sizeof (short));
    }
  /* Entry empty? Fill it in.  */
  if (z8k_inv_list[what] == -1)
    {

      int nibl_index;
      int nibl_matched;
      unsigned short instr_nibl;
      unsigned short tabl_datum, datum_class, datum_value;
      char instr_nibbles[8];

      opcode_entry_type *ptr = z8k_table;

      nibl_matched = 0;

      instr_nibbles[3] = (what >> 0) & 0xf;
      instr_nibbles[2] = (what >> 4) & 0xf;
      instr_nibbles[1] = (what >> 8) & 0xf;
      instr_nibbles[0] = (what >> 12) & 0xf;

      /* Assume it won't be found.  */
      z8k_inv_list[what] = -2;

      while (ptr->name)
	{
	  nibl_matched = 1;
	  for (nibl_index = 0; nibl_index < 4 && nibl_matched; nibl_index++)
	    {
	      instr_nibl = instr_nibbles[nibl_index];

	      tabl_datum = ptr->byte_info[nibl_index];
	      datum_class = tabl_datum & CLASS_MASK;
	      datum_value = ~CLASS_MASK & tabl_datum;

	      switch (datum_class)
		{
		case CLASS_BIT_1OR2:
		  if (datum_value != (instr_nibl & ~0x2))
		    nibl_matched = 0;
		  break;

		case CLASS_IGNORE:
		  break;
		case CLASS_BIT:
		  if (datum_value != instr_nibl)
		    nibl_matched = 0;
		  break;
		case CLASS_00II:
		  if (!((~instr_nibl) & 0x4))
		    nibl_matched = 0;
		  break;
		case CLASS_01II:
		  if (!(instr_nibl & 0x4))
		    nibl_matched = 0;
		  break;
		case CLASS_0CCC:
		  if (!((~instr_nibl) & 0x8))
		    nibl_matched = 0;
		  break;
		case CLASS_1CCC:
		  if (!(instr_nibl & 0x8))
		    nibl_matched = 0;
		  break;
		case CLASS_0DISP7:
		  if (!((~instr_nibl) & 0x8))
		    nibl_matched = 0;
		  nibl_index += 1;
		  break;
		case CLASS_1DISP7:
		  if (!(instr_nibl & 0x8))
		    nibl_matched = 0;
		  nibl_index += 1;
		  break;
		case CLASS_REGN0:
		  if (instr_nibl == 0)
		    nibl_matched = 0;
		  break;
		default:
		  break;
		}
	    }
	  if (nibl_matched)
	    {
	      z8k_inv_list[what] = ptr->idx;
	      break; /* while */
	    }
	  ptr++;
	}
    }
  if (z8k_inv_list[what] >= 0)
    return z8k_table + z8k_inv_list[what];
  return 0;
}

static char *
insn_4 (n)
     int n;
{
  switch (n)
    {
    case 1:
      return "((iwords_0>>8) & 0xf)";
    case 2:
      return "((ibytes_1 >> 4) & 0xf)";
    case 3:
      return "((ibytes_1) & 0xf)";
    case 4:
      return "((ibytes_2>>4) & 0xf)";
    case 5:
      return "((ibytes_2) & 0xf)";
    case 6:
      return "((ibytes_3 >> 4) & 0xf)";
    case 7:
      return "((ibytes_3) & 0xf)";
    default:
      return "****";
    }
}

char *
ptr_mode ()
{
  if (BIG)
    {
      return "ptr_long";
    }
  return "word";
}

static
char *
ptr_size ()
{
  if (BIG)
    return "4";
  return "2";
}

static char *
reg_n (x)
     unsigned int x;
{
  return reg_names[x & 0xf];
}

char *
stack_ptr ()
{
  return BIG ? "14" : "15";
}

char *
mem ()
{
#if 0
  return BIG ? "segmem" : "unsegmem";
#else
  return "mem";
#endif
}

int
match (a)
     char *a;
{
  if (strncmp (p, a, strlen (a)) == 0)
    {
      p += strlen (a);
      return 1;
    }
  return 0;
}

static
void
sub (y)
     char *y;
{
  sprintf (d, "%s", y);
  d += strlen (d);
}

static char *
insn_16 (n)
     int n;
{
  switch (n)
    {
    case 0:
      return "(iwords_0)";
    case 4:
      return "(iwords_1)";
    case 8:
      return "(iwords_2)";
    case 12:
      return "(iwords_3)";
    default:
      return "****";
    }
}

static
char *
insn_32 (n)
     int n;
{
  switch (n)
    {
    case 0:
      return "((iwords_0<<16) | (iwords_1))";
    case 4:
      return "((iwords_1<<16) | (iwords_2))";
    case 8:
      return "((iwords_2<<16) | (iwords_3))";
    default:
      return "****";
    }
}

static char *
size_name (x)
     int x;
{
  switch (x)
    {
    case 8:
      return "byte";
    case 16:
      return "word";
    case 32:
      return "long";
    case 64:
      return "quad";
    }
  return "!!";
}

/*VARARGS*/
void
emit (string, a1, a2, a3, a4, a5)
     char *string;
     char* a1;
     char* a2;
     char* a3;
     char* a4;
     char* a5;
{
  int indent_inc = 0;
  int indent_dec = 0;
  int i;
  char buffer[1000];

  d = buffer;
  p = string;

  while (*p)
    {
      if (match ("<fop>"))
	{
	  if (BIG)
	    {
	      sub ("bfop");
	    }
	  else
	    {
	      sub ("sfop");
	    }
	}
      else if (match ("<iptr>"))
	{
	  if (BIG)
	    {
	      switch (nibs)
		{
		case 4:
		  sub ("(((iwords_1 << 8) | (iwords_2)) & 0x7fffff)");
		  break;
		default:
		  sub ("fail(context,124)");
		  break;
		}
	    }
	  else
	    {
	      switch (nibs)
		{
		case 4:
		  sub ("iwords_1");
		  break;
		default:
		  sub ("fail(context,123)");
		  break;
		}
	    }
	}
      else if (match ("<name>"))
	{
	  sub (current_name);
	}
      else if (match ("<size>"))
	{
	  sub (current_size);
	}
      else if (match ("<insn_4>"))
	{
	  sub (insn_4 (nibs));
	}
      else if (match ("<insn_16>"))
	{
	  sub (insn_16 (nibs));
	}
      else if (match ("<insn_32>"))
	{
	  sub (insn_32 (nibs));
	}
      else if (match ("iwords_0"))
	{
	  sub (current_word0);
	}
      else if (match ("ibytes_0"))
	{
	  sub (current_byte0);
	}
      else if (match ("<ibytes_1>"))
	{
	  sub (current_byte1);
	}
      else if (match ("<next_size>"))
	{
	  if (strcmp (current_size, "word") == 0)
	    sub ("long");
	  if (strcmp (current_size, "byte") == 0)
	    sub ("word");
	  else if (strcmp (current_size, "long") == 0)
	    sub ("quad");
	  else
	    abort ();
	}
      else if (match ("<addr_type>"))
	{
	  if (BIG)
	    sub ("unsigned long");
	  else
	    sub ("unsigned short");
	}

      else if (match ("<c_size>"))
	{
	  if (strcmp (current_size, "word") == 0)
	    sub ("short");
	  else if (strcmp (current_size, "byte") == 0)
	    sub ("char");
	  else if (strcmp (current_size, "long") == 0)
	    sub ("long");
	  else
	    abort ();
	}

      else if (match ("<pc>"))
	{
	  sub ("pc");
	}
      else if (match ("<mem>"))
	{
	  sub (mem ());
	}
      else if (match ("<sp>"))
	{
	  sub (stack_ptr ());
	}
      else if (match ("<ptr_size>"))
	{
	  sub (ptr_size ());
	}
      else if (match ("<ptr_mode>"))
	{
	  sub (ptr_mode ());
	}
      else if (match ("<insn_8>"))
	{
	  switch (nibs)
	    {
	    case 2:
	      sub ("(iwords_0&0xff)");
	      break;
	    case 4:
	      sub ("(iwords_1>>8)");
	      break;
	    case 6:
	      sub ("(iwords_1&0xff)");
	      break;
	    case 8:
	      sub ("(iwords_2>>8)");
	      break;
	    case 12:
	      sub ("(/* WHO */iwords_3&0xff)");
	      break;
	    default:
	      abort ();
	    }
	}
      else
	{
	  if (*p == '{')
	    indent_inc++;
	  if (*p == '}')
	    indent_dec++;
	  *d++ = *p;
	  p++;
	}
    }
  *d++ = 0;
  indent -= indent_dec;
  for (i = 0; i < indent; i++)
    printf ("\t");
  indent += indent_inc;
  printf (buffer, a1, a2, a3, a4, a5);

}

/* fetch the lvalues of the operands */
void
info_args (p)
     opcode_entry_type *p;
{
  unsigned int *s;

  int done_one_imm8 = 0;

  /* int done_read = 4;*/
  s = p->byte_info;
  nibs = 0;
  while (*s)
    {
      switch (*s & CLASS_MASK)
	{
	case CLASS_BIT_1OR2:
	  emit ("register unsigned int imm_src=(<insn_4>& 2)?2:1;\n");
	  break;
	case CLASS_IGNORE:
	case CLASS_BIT:
	  /* Just ignore these, we've already decoded this bit */
	  nibs++;
	  break;
	case CLASS_REGN0:
	case CLASS_REG:
	  /* this nibble tells us which register to use as an arg,
	     if we've already gobbled the nibble we know what to use */
	  {
	    int regname = *s & 0xf;

	    emit ("register unsigned int reg_%s=<insn_4>;\n",
		  reg_names[regname]);

	    nibs++;
	  }
	  break;
	case CLASS_ADDRESS:
	  emit ("register unsigned base_%s=<iptr>;\n", reg_n (*s));

	  nibs += SIZE_ADDRESS;

	  break;
	case CLASS_01II:
	case CLASS_00II:
	  emit ("register unsigned int imm_src=<insn_4>&0x2;\n");
	  nibs++;
	  break;
	case CLASS_FLAGS:
		emit ("register unsigned int imm_src=<insn_4>;\n");
		nibs++;
break;	  
	case CLASS_IMM:
	  /* Work out the size of the think to fetch */

	  {
	    switch (*s & ~CLASS_MASK)
	      {
	      case ARG_IMM16:
		emit ("register unsigned imm_src=<insn_16>;\n");
		nibs += 4;
		break;
	      case ARG_IMM32:
		emit ("register unsigned int imm_src= %s;\n", insn_32 (nibs));
		nibs += 8;
		break;
	      case ARG_IMM4:
		emit ("register unsigned int imm_src=<insn_4>;\n");
		nibs++;
		break;
	      case ARG_NIM4:
		emit ("register unsigned int imm_src = - <insn_4>;\n");
		nibs++;
		break;
	      case ARG_IMM2:
		emit ("register unsigned int imm_src=<insn_4> & 0x2;\n");
		nibs++;
		break;

	      case ARG_IMM4M1:
		emit ("register unsigned int imm_src=(<insn_4> + 1);\n");
		nibs++;
		break;
	      case ARG_IMM_1:
		emit ("register unsigned int imm_src=1;\n");
		break;
	      case ARG_IMM_2:
		emit ("register unsigned int imm_src=2;\n");
		break;
	      case ARG_NIM8:
		emit ("register unsigned int imm_src=-<insn_8>;\n");
		nibs += 2;
		break;
	      case ARG_IMM8:
		if (!done_one_imm8)
		  {
		    emit ("register unsigned int imm_src=<insn_8>;\n");
		    nibs += 2;
		    done_one_imm8 = 1;
		  }
		break;
	      default:
		emit ("register int fail%d=fail(context,1);\n", nibs);
		break;
	      }
	    break;

	case CLASS_DISP8:
	    /* We can't use `(char)' since char might be unsigned.
	       We can't use `(signed char)' because the compiler might be K&R.
	       This seems safe, since it only assumes that bytes are 8
	       bits.  */
	    emit ("register unsigned int oplval_dst=((ibytes_1 << (sizeof (int) * 8 - 8)) >> (sizeof (int) * 8 - 9)) + pc;\n");
#if 0
	    /* Original code: fails if characters are unsigned.  */
	    emit ("register unsigned int oplval_dst=(((char)ibytes_1)<<1) + pc;\n");
#endif
	    nibs += 2;
	    break;
	case CLASS_CC:
	    emit ("register unsigned int op_cc=<insn_4>;\n");
	    nibs++;
	    break;
	default: