#include <signal.h>
#include "sysdep.h"
#include "bfd.h"

#include "mn10300_sim.h"

host_callback *mn10300_callback;
int mn10300_debug;
static SIM_OPEN_KIND sim_kind;
static char *myname;

static void dispatch PARAMS ((uint32, uint32, int));
static long hash PARAMS ((long));
static void init_system PARAMS ((void));
#define MAX_HASH  127

struct hash_entry
{
  struct hash_entry *next;
  long opcode;
  long mask;
  struct simops *ops;
#ifdef HASH_STAT
  unsigned long count;
#endif
};

static int max_mem = 0;
struct hash_entry hash_table[MAX_HASH+1];


/* This probably doesn't do a very good job at bucket filling, but
   it's simple... */
static INLINE long 
hash(insn)
     long insn;
{
  /* These are one byte insns, we special case these since, in theory,
     they should be the most heavily used.  */
  if ((insn & 0xffffff00) == 0)
    {
      switch (insn & 0xf0)
	{
	  case 0x00:
	    return 0x70;

	  case 0x40:
	    return 0x71;

	  case 0x10:
	    return 0x72;

	  case 0x30:
	    return 0x73;

	  case 0x50:
	    return 0x74;

	  case 0x60:
	    return 0x75;

	  case 0x70:
	    return 0x76;

	  case 0x80:
	    return 0x77;

	  case 0x90:
	    return 0x78;

	  case 0xa0:
	    return 0x79;

	  case 0xb0:
	    return 0x7a;

	  case 0xe0:
	    return 0x7b;

	  default:
	    return 0x7c;
	}
    }

  /* These are two byte insns */
  if ((insn & 0xffff0000) == 0)
    {
      if ((insn & 0xf000) == 0x2000
	  || (insn & 0xf000) == 0x5000)
	return ((insn & 0xfc00) >> 8) & 0x7f;

      if ((insn & 0xf000) == 0x4000)
	return ((insn & 0xf300) >> 8) & 0x7f;

      if ((insn & 0xf000) == 0x8000
	  || (insn & 0xf000) == 0x9000
	  || (insn & 0xf000) == 0xa000
	  || (insn & 0xf000) == 0xb000)
	return ((insn & 0xf000) >> 8) & 0x7f;

      if ((insn & 0xff00) == 0xf000
	  || (insn & 0xff00) == 0xf100
	  || (insn & 0xff00) == 0xf200
	  || (insn & 0xff00) == 0xf500
	  || (insn & 0xff00) == 0xf600)
	return ((insn & 0xfff0) >> 4) & 0x7f;
 
      if ((insn & 0xf000) == 0xc000)
	return ((insn & 0xff00) >> 8) & 0x7f;

      return ((insn & 0xffc0) >> 6) & 0x7f;
    }

  /* These are three byte insns.  */
  if ((insn & 0xff000000) == 0)
    {
      if ((insn & 0xf00000) == 0x000000)
	return ((insn & 0xf30000) >> 16) & 0x7f;

      if ((insn & 0xf00000) == 0x200000
	  || (insn & 0xf00000) == 0x300000)
	return ((insn & 0xfc0000) >> 16) & 0x7f;

      if ((insn & 0xff0000) == 0xf80000)
	return ((insn & 0xfff000) >> 12) & 0x7f;

      if ((insn & 0xff0000) == 0xf90000)
	return ((insn & 0xfffc00) >> 10) & 0x7f;

      return ((insn & 0xff0000) >> 16) & 0x7f;
    }

  /* These are four byte or larger insns.  */
  if ((insn & 0xf0000000) == 0xf0000000)
    return ((insn & 0xfff00000) >> 20) & 0x7f;

  return ((insn & 0xff000000) >> 24) & 0x7f;
}

static INLINE void
dispatch (insn, extension, length)
     uint32 insn;
     uint32 extension;
     int length;
{
  struct hash_entry *h;

  h = &hash_table[hash(insn)];

  while ((insn & h->mask) != h->opcode
	  || (length != h->ops->length))
    {
      if (!h->next)
	{
	  (*mn10300_callback->printf_filtered) (mn10300_callback,
	    "ERROR looking up hash for 0x%x, PC=0x%x\n", insn, PC);
	  exit(1);
	}
      h = h->next;
    }


#ifdef HASH_STAT
  h->count++;
#endif

  /* Now call the right function.  */
  (h->ops->func)(insn, extension);
  PC += length;
}

/* FIXME These would more efficient to use than load_mem/store_mem,
   but need to be changed to use the memory map.  */

uint8
get_byte (x)
     uint8 *x;
{
  return *x;
}

uint16
get_half (x)
     uint8 *x;
{
  uint8 *a = x;
  return (a[1] << 8) + (a[0]);
}

uint32
get_word (x)
      uint8 *x;
{
  uint8 *a = x;
  return (a[3]<<24) + (a[2]<<16) + (a[1]<<8) + (a[0]);
}

void
put_byte (addr, data)
     uint8 *addr;
     uint8 data;
{
  uint8 *a = addr;
  a[0] = data;
}

void
put_half (addr, data)
     uint8 *addr;
     uint16 data;
{
  uint8 *a = addr;
  a[0] = data & 0xff;
  a[1] = (data >> 8) & 0xff;
}

void
put_word (addr, data)
     uint8 *addr;
     uint32 data;
{
  uint8 *a = addr;
  a[0] = data & 0xff;
  a[1] = (data >> 8) & 0xff;
  a[2] = (data >> 16) & 0xff;
  a[3] = (data >> 24) & 0xff;
}

void
sim_size (power)
     int power;

{
  if (State.mem)
    free (State.mem);

  max_mem = 1 << power;
  State.mem = (uint8 *) calloc (1,  1 << power);
  if (!State.mem)
    {
      (*mn10300_callback->printf_filtered) (mn10300_callback, "Allocation of main memory failed.\n");
      exit (1);
    }
}

static void
init_system ()
{
  if (!State.mem)
    sim_size(19);
}

int
sim_write (sd, addr, buffer, size)
     SIM_DESC sd;
     SIM_ADDR addr;
     unsigned char *buffer;
     int size;
{
  int i;

  init_system ();

  for (i = 0; i < size; i++)
    store_byte (addr + i, buffer[i]);

  return size;
}

/* Compare two opcode table entries for qsort.  */
static int
compare_simops (arg1, arg2)
     const PTR arg1;
     const PTR arg2;
{
  unsigned long code1 = ((struct simops *)arg1)->opcode;
  unsigned long code2 = ((struct simops *)arg2)->opcode;

  if (code1 < code2)
    return -1;
  if (code2 < code1)
    return 1;
  return 0;
}

SIM_DESC
sim_open (kind, cb, abfd, argv)
     SIM_OPEN_KIND kind;
     host_callback *cb;
     struct _bfd *abfd;
     char **argv;
{
  struct simops *s;
  struct hash_entry *h;
  char **p;
  int i;

  mn10300_callback = cb;

  /* Sort the opcode array from smallest opcode to largest.
     This will generally improve simulator performance as the smaller
     opcodes are generally preferred to the larger opcodes.  */
  for (i = 0, s = Simops; s->func; s++, i++)
    ;
  qsort (Simops, i, sizeof (Simops[0]), compare_simops);

  sim_kind = kind;
  myname = argv[0];

  for (p = argv + 1; *p; ++p)
    {
      if (strcmp (*p, "-E") == 0)
	++p; /* ignore endian spec */
      else
#ifdef DEBUG
      if (strcmp (*p, "-t") == 0)
	mn10300_debug = DEBUG;
      else
#endif
	(*mn10300_callback->printf_filtered) (mn10300_callback, "ERROR: unsupported option(s): %s\n",*p);
    }

 /* put all the opcodes in the hash table */
  for (s = Simops; s->func; s++)
    {
      h = &hash_table[hash(s->opcode)];

      /* go to the last entry in the chain */
      while (h->next)
	{
	  /* Don't insert the same opcode more than once.  */
	  if (h->opcode == s->opcode
	      && h->mask == s->mask
	      && h->ops == s)
	    break;
	  else
	    h = h->next;
	}

      /* Don't insert the same opcode more than once.  */
      if (h->opcode == s->opcode
	  && h->mask == s->mask
	  && h->ops == s)
	continue;

      if (h->ops)
	{
	  h->next = calloc(1,sizeof(struct hash_entry));
	  h = h->next;
	}
      h->ops = s;
      h->mask = s->mask;
      h->opcode = s->opcode;
#if HASH_STAT
      h->count = 0;
#endif
    }


  /* fudge our descriptor for now */
  return (SIM_DESC) 1;
}


void
sim_close (sd, quitting)
     SIM_DESC sd;
     int quitting;
{
  /* nothing to do */
}

void
sim_set_profile (n)
     int n;
{
  (*mn10300_callback->printf_filtered) (mn10300_callback, "sim_set_profile %d\n", n);
}

void
sim_set_profile_size (n)
     int n;
{
  (*mn10300_callback->printf_filtered) (mn10300_callback, "sim_set_profile_size %d\n", n);
}

int
sim_stop (sd)
     SIM_DESC sd;
{
  return 0;
}

void
sim_resume (sd, step, siggnal)
     SIM_DESC sd;
     int step, siggnal;
{
  uint32 inst;
  reg_t oldpc;
  struct hash_entry *h;

  if (step)
    State.exception = SIGTRAP;
  else
    State.exception = 0;

  State.exited = 0;

  do
    {
      unsigned long insn, extension;

      /* Fetch the current instruction.  */
      inst = load_mem_big (PC, 2);
      oldpc = PC;

      /* Using a giant case statement may seem like a waste because of the
 	code/rodata size the table itself will consume.  However, using
 	a giant case statement speeds up the simulator by 10-15% by avoiding
 	cascading if/else statements or cascading case statements.  */

      switch ((inst >> 8) & 0xff)
	{
	  /* All the single byte insns except 0x80, 0x90, 0xa0, 0xb0
	     which must be handled specially.  */
	  case 0x00:
	  case 0x04:
	  case 0x08:
	  case 0x0c:
	  case 0x10:
	  case 0x11:
	  case 0x12:
	  case 0x13:
	  case 0x14:
	  case 0x15:
	  case 0x16:
	  case 0x17:
	  case 0x18:
	  case 0x19:
	  case 0x1a:
	  case 0x1b:
	  case 0x1c:
	  case 0x1d:
	  case 0x1e:
	  case 0x1f:
	  case 0x3c:
	  case 0x3d:
	  case 0x3e:
	  case 0x3f:
	  case 0x40:
	  case 0x41:
	  case 0x44:
	  case 0x45:
	  case 0x48:
	  case 0x49:
	  case 0x4c:
	  case 0x4d:
	  case 0x50:
	  case 0x51:
	  case 0x52:
	  case 0x53:
	  case 0x54:
	  case 0x55:
	  case 0x56:
	  case 0x57:
	  case 0x60:
	  case 0x61:
	  case 0x62:
	  case 0x63:
	  case 0x64:
	  case 0x65:
	  case 0x66:
	  case 0x67:
	  case 0x68:
	  case 0x69:
	  case 0x6a:
	  case 0x6b:
	  case 0x6c:
	  case 0x6d:
	  case 0x6e:
	  case 0x6f:
	  case 0x70:
	  case 0x71:
	  case 0x72:
	  case 0x73:
	  case 0x74:
	  case 0x75:
	  case 0x76:
	  case 0x77:
	  case 0x78:
	  case 0x79:
	  case 0x7a:
	  case 0x7b:
	  case 0x7c:
	  case 0x7d:
	  case 0x7e:
	  case 0x7f:
	  case 0xcb:
	  case 0xd0:
	  case 0xd1:
	  case 0xd2:
	  case 0xd3:
	  case 0xd4:
	  case 0xd5:
	  case 0xd6:
	  case 0xd7:
	  case 0xd8:
	  case 0xd9:
	  case 0xda:
	  case 0xdb:
	  case 0xe0:
	  case 0xe1:
	  case 0xe2:
	  case 0xe3:
	  case 0xe4:
	  case 0xe5:
	  case 0xe6:
	  case 0xe7:
	  case 0xe8:
	  case 0xe9:
	  case 0xea:
	  case 0xeb:
	  case 0xec:
	  case 0xed:
	  case 0xee:
	  case 0xef:
	  case 0xff:
	    insn = (inst >> 8) & 0xff;
	    extension = 0;
	    dispatch (insn, extension, 1);
	    break;

	  /* Special cases where dm == dn is used to encode a different
	     instruction.  */
	  case 0x80:
	  case 0x85:
	  case 0x8a:
	  case 0x8f:
	  case 0x90:
	  case 0x95:
	  case 0x9a:
	  case 0x9f:
	  case 0xa0:
	  case 0xa5:
	  case 0xaa:
	  case 0xaf:
	  case 0xb0:
	  case 0xb5:
	  case 0xba:
	  case 0xbf:
	    insn = inst;
	    extension = 0;
	    dispatch (insn, extension, 2);
	    break;

	  case 0x81:
	  case 0x82:
	  case 0x83:
	  case 0x84:
	  case 0x86:
	  case 0x87:
	  case 0x88:
	  case 0x89:
	  case 0x8b:
	  case 0x8c:
	  case 0x8d:
	  case 0x8e:
	  case 0x91:
	  case 0x92:
	  case 0x93:
	  case 0x94:
	  case 0x96:
	  case 0x97:
	  case 0x98:
	  case 0x99:
	  case 0x9b:
	  case 0x9c:
	  case 0x9d:
	  case 0x9e:
	  case 0xa1:
	  case 0xa2:
	  case 0xa3:
	  case 0xa4:
	  case 0xa6:
	  case 0xa7:
	  case 0xa8:
	  case 0xa9:
	  case 0xab:
	  case 0xac:
	  case 0xad:
	  case 0xae:
	  case 0xb1:
	  case 0xb2:
	  case 0xb3:
	  case 0xb4:
	  case 0xb6:
	  case 0xb7:
	  case 0xb8:
	  case 0xb9:
	  case 0xbb:
	  case 0xbc:
	  case 0xbd:
	  case 0xbe:
	    insn = (inst >> 8) & 0xff;
	    extension = 0;
	  dispatch (insn, extension, 1);
	  break;

	  /* The two byte instructions.  */
	  case 0x20:
	  case 0x21:
	  case 0x22:
	  case 0x23:
	  case 0x28:
	  case 0x29:
	  case 0x2a:
	  case 0x2b:
	  case 0x42:
	  case 0x43:
	  case 0x46:
	  case 0x47:
	  case 0x4a:
	  case 0x4b:
	  case 0x4e:
	  case 0x4f:
	  case 0x58:
	  case 0x59:
	  case 0x5a:
	  case 0x5b:
	  case 0x5c:
	  case 0x5d:
	  case 0x5e:
	  case 0x5f:
	  case 0xc0:
	  case 0xc1:
	  case 0xc2:
	  case 0xc3:
	  case 0xc4:
	  case 0xc5:
	  case 0xc6:
	  case 0xc7:
	  case 0xc8:
	  case 0xc9:
	  case 0xca:
	  case 0xce:
	  case 0xcf:
	  case 0xf0:
	  case 0xf1:
	  case 0xf2:
	  case 0xf3:
	  case 0xf4:
	  case 0xf5:
	  case 0xf6:
	    insn = inst;
	    extension = 0;
	    dispatch (insn, extension, 2);
	    break;

	  /* The three byte insns with a 16bit operand in little endian
	     format.  */
	  case 0x01:
	  case 0x02:
	  case 0x03:
	  case 0x05:
	  case 0x06:
	  case 0x07:
	  case 0x09:
	  case 0x0a:
	  case 0x0b:
	  case 0x0d:
	  case 0x0e:
	  case 0x0f:
	  case 0x24:
	  case 0x25:
	  case 0x26:
	  case 0x27:
	  case 0x2c:
	  case 0x2d:
	  case 0x2e:
	  case 0x2f:
	  case 0x30:
	  case 0x31:
	  case 0x32:
	  case 0x33:
	  case 0x34:
	  case 0x35:
	  case 0x36:
	  case 0x37:
	  case 0x38:
	  case 0x39:
	  case 0x3a:
	  case 0x3b:
	  case 0xcc:
	    insn = load_byte (PC);
	    insn <<= 16;
	    insn |= load_half (PC + 1);
	    extension = 0;
	    dispatch (insn, extension, 3);
	    break;

	  /* The three byte insns without 16bit operand.  */
	  case 0xde:
	  case 0xdf:
	  case 0xf8:
	  case 0xf9:
	    insn = load_mem_big (PC, 3);
	    extension = 0;
	    dispatch (insn, extension, 3);
	    break;
	  
	  /* Four byte insns.  */
	  case 0xfa:
	  case 0xfb:
	    if ((inst & 0xfffc) == 0xfaf0
		|| (inst & 0xfffc) == 0xfaf4
		|| (inst & 0xfffc) == 0xfaf8)
	      insn = load_mem_big (PC, 4);
	    else
	      {
		insn = inst;
		insn <<= 16;
		insn |= load_half (PC + 2);
		extension = 0;
	      }
	    dispatch (insn, extension, 4);
	    break;

	  /* Five byte insns.  */
	  case 0xcd:
	    insn = load_byte (PC);
	    insn <<= 24;
	    insn |= (load_half (PC + 1) << 8);
	    insn |= load_byte (PC + 3);
	    extension = load_byte (PC + 4);
	    dispatch (insn, extension, 5);
	    break;

	  case 0xdc:
	    insn = load_byte (PC);
	    insn <<= 24;
	    extension = load_word (PC + 1);
	    insn |= (extension & 0xffffff00) >> 8;
	    extension &= 0xff;
	    dispatch (insn, extension, 5);
	    break;
	
	  /* Six byte insns.  */
	  case 0xfc:
	  case 0xfd:
	    insn = (inst << 16);
	    extension = load_word (PC + 2);
	    insn |= ((extension & 0xffff0000) >> 16);
	    extension &= 0xffff;
	    dispatch (insn, extension, 6);
	    break;
	    
	  case 0xdd:
	    insn = load_byte (PC) << 24;
	    extension = load_word (PC + 1);
	    insn |= ((extension >> 8) & 0xffffff);
	    extension = (extension & 0xff) << 16;
	    extension |= load_byte (PC + 5) << 8;
	    extension |= load_byte (PC + 6);
	    dispatch (insn, extension, 7);
	    break;

	  case 0xfe:
	    insn = inst << 16;
	    extension = load_word (PC + 2);
	    insn |= ((extension >> 16) & 0xffff);
	    extension <<= 8;
	    extension &= 0xffff00;
	    extension |= load_byte (PC + 6);
	    dispatch (insn, extension, 7);
	    break;

	  default:
	    abort ();
	}
    }
  while (!State.exception);

#ifdef HASH_STAT
  {
    int i;
    for (i = 0; i < MAX_HASH; i++)
      {
	 struct hash_entry *h;
	 h = &hash_table[i];

	 printf("hash 0x%x:\n", i);

	 while (h)
	   {
	     printf("h->opcode = 0x%x, count = 0x%x\n", h->opcode, h->count);
	     h = h->next;
	   }

	 printf("\n\n");
      }
    fflush (stdout);
  }
#endif

}

int
sim_trace (sd)
     SIM_DESC sd;
{
#ifdef DEBUG
  mn10300_debug = DEBUG;
#endif
  sim_resume (sd, 0, 0);
  return 1;
}

void
sim_info (sd, verbose)
     SIM_DESC sd;
     int verbose;
{
  (*mn10300_callback->printf_filtered) (mn10300_callback, "sim_info\n");
}

SIM_RC
sim_create_inferior (sd, argv, env)
     SIM_DESC sd;
     char **argv;
     char **env;
{
  return SIM_RC_OK;
}

void
sim_kill (sd)
     SIM_DESC sd;
{
  /* nothing to do */
}

void
sim_set_callbacks (p)
     host_callback *p;
{
  mn10300_callback = p;
}

/* All the code for exiting, signals, etc needs to be revamped.

   This is enough to get c-torture limping though.  */

void
sim_stop_reason (sd, reason, sigrc)
     SIM_DESC sd;
     enum sim_stop *reason;
     int *sigrc;
{
  if (State.exited)
    *reason = sim_exited;
  else
    *reason = sim_stopped;
  if (State.exception == SIGQUIT)
    *sigrc = 0;
  else
    *sigrc = State.exception;
}

void
sim_fetch_register (sd, rn, memory)
     SIM_DESC sd;
     int rn;
     unsigned char *memory;
{
  put_word (memory, State.regs[rn]);
}
 
void
sim_store_register (sd, rn, memory)
     SIM_DESC sd;
     int rn;
     unsigned char *memory;
{
  State.regs[rn] = get_word (memory);
}

int
sim_read (sd, addr, buffer, size)
     SIM_DESC sd;
     SIM_ADDR addr;
     unsigned char *buffer;
     int size;
{
  int i;
  for (i = 0; i < size; i++)
    buffer[i] = load_byte (addr + i);

  return size;
} 

void
sim_do_command (sd, cmd)
     SIM_DESC sd;
     char *cmd;
{
  (*mn10300_callback->printf_filtered) (mn10300_callback, "\"%s\" is not a valid mn10300 simulator command.\n", cmd);
}

SIM_RC
sim_load (sd, prog, abfd, from_tty)
     SIM_DESC sd;
     char *prog;
     bfd *abfd;
     int from_tty;
{
  extern bfd *sim_load_file (); /* ??? Don't know where this should live.  */
  bfd *prog_bfd;

  prog_bfd = sim_load_file (sd, myname, mn10300_callback, prog, abfd,
			    sim_kind == SIM_OPEN_DEBUG);
  if (prog_bfd == NULL)
    return SIM_RC_FAIL;
  PC = bfd_get_start_address (prog_bfd);
  if (abfd == NULL)
    bfd_close (prog_bfd);
  return SIM_RC_OK;
}