/* srcdest.c --- decoding M32C addressing modes.

Copyright (C) 2005, 2007, 2008, 2009, 2010, 2011
Free Software Foundation, Inc.
Contributed by Red Hat, Inc.

This file is part of the GNU simulators.

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 <stdio.h>
#include <stdlib.h>

#include "cpu.h"
#include "mem.h"

static int src_indirect = 0;
static int dest_indirect = 0;
static int src_addend = 0;
static int dest_addend = 0;

static int
disp8 ()
{
  int rv;
  int tsave = trace;

  if (trace == 1)
    trace = 0;
  rv = mem_get_qi (get_reg (pc));
  regs.r_pc++;
  trace = tsave;
  return rv;
}

static int
disp16 ()
{
  int rv;
  int tsave = trace;

  if (trace == 1)
    trace = 0;
  rv = mem_get_hi (get_reg (pc));
  regs.r_pc += 2;
  trace = tsave;
  return rv;
}

static int
disp24 ()
{
  int rv;
  int tsave = trace;

  if (trace == 1)
    trace = 0;
  rv = mem_get_psi (get_reg (pc));
  regs.r_pc += 3;
  trace = tsave;
  return rv;
}

static int
disp20 ()
{
  return disp24 () & 0x000fffff;
}

const char *
bits (int v, int b)
{
  static char buf[17];
  char *bp = buf + 16;
  *bp = 0;
  while (b)
    {
      *--bp = (v & 1) ? '1' : '0';
      v >>= 1;
      b--;
    }
  return bp;
}

static const char *the_bits = 0;

void
decode_indirect (int si, int di)
{
  src_indirect = si;
  dest_indirect = di;
  if (trace && (si || di))
    printf ("indirect: s:%d d:%d\n", si, di);
}

void
decode_index (int sa, int da)
{
  src_addend = sa;
  dest_addend = da;
  if (trace && (sa || da))
    printf ("index: s:%d d:%d\n", sa, da);
}

srcdest
decode_srcdest4 (int destcode, int bw)
{
  srcdest sd;
  sd.bytes = bw ? 2 : 1;
  sd.mem = (destcode >= 6) ? 1 : 0;
  static const char *dc_wnames[16] = { "r0", "r1", "r2", "r3",
    "a0", "a1", "[a0]", "[a1]",
    "disp8[a0]", "disp8[a1]", "disp8[sb]", "disp8[fb]",
    "disp16[a0]", "disp16[a1]", "disp16[sb]", "disp16"
  };
  static const char *dc_bnames[4] = { "r0l", "r0h", "r1l", "r1h" };;

  if (trace)
    {
      const char *n = dc_wnames[destcode];
      if (bw == 0 && destcode <= 3)
	n = dc_bnames[destcode];
      if (!the_bits)
	the_bits = bits (destcode, 4);
      printf ("decode: %s (%d) : %s\n", the_bits, destcode, n);
      the_bits = 0;
    }

  switch (destcode)
    {
    case 0x0:
      sd.u.reg = bw ? r0 : r0l;
      break;
    case 0x1:
      sd.u.reg = bw ? r1 : r0h;
      break;
    case 0x2:
      sd.u.reg = bw ? r2 : r1l;
      break;
    case 0x3:
      sd.u.reg = bw ? r3 : r1h;
      break;
    case 0x4:
      sd.u.reg = a0;
      break;
    case 0x5:
      sd.u.reg = a1;
      break;
    case 0x6:
      sd.u.addr = get_reg (a0);
      break;
    case 0x7:
      sd.u.addr = get_reg (a1);
      break;
    case 0x8:
      sd.u.addr = get_reg (a0) + disp8 ();
      break;
    case 0x9:
      sd.u.addr = get_reg (a1) + disp8 ();
      break;
    case 0xa:
      sd.u.addr = get_reg (sb) + disp8 ();
      break;
    case 0xb:
      sd.u.addr = get_reg (fb) + sign_ext (disp8 (), 8);
      break;
    case 0xc:
      sd.u.addr = get_reg (a0) + disp16 ();
      break;
    case 0xd:
      sd.u.addr = get_reg (a1) + disp16 ();
      break;
    case 0xe:
      sd.u.addr = get_reg (sb) + disp16 ();
      break;
    case 0xf:
      sd.u.addr = disp16 ();
      break;
    default:
      abort ();
    }
  if (sd.mem)
    sd.u.addr &= addr_mask;
  return sd;
}

srcdest
decode_jumpdest (int destcode, int w)
{
  srcdest sd;
  sd.bytes = w ? 2 : 3;
  sd.mem = (destcode >= 6) ? 1 : 0;
  static const char *dc_wnames[16] = { "r0", "r1", "r2", "r3",
    "a0", "a1", "[a0]", "[a1]",
    "disp8[a0]", "disp8[a1]", "disp8[sb]", "disp8[fb]",
    "disp20[a0]", "disp20[a1]", "disp16[sb]", "abs16"
  };
  static const char *dc_anames[4] = { "r0l", "r0h", "r1l", "r1h" };

  if (trace)
    {
      const char *n = dc_wnames[destcode];
      if (w == 0 && destcode <= 3)
	n = dc_anames[destcode];
      if (!the_bits)
	the_bits = bits (destcode, 4);
      printf ("decode: %s : %s\n", the_bits, n);
      the_bits = 0;
    }

  switch (destcode)
    {
    case 0x0:
      sd.u.reg = w ? r0 : r2r0;
      break;
    case 0x1:
      sd.u.reg = w ? r1 : r2r0;
      break;
    case 0x2:
      sd.u.reg = w ? r2 : r3r1;
      break;
    case 0x3:
      sd.u.reg = w ? r3 : r3r1;
      break;
    case 0x4:
      sd.u.reg = w ? a0 : a1a0;
      break;
    case 0x5:
      sd.u.reg = w ? a1 : a1a0;
      break;
    case 0x6:
      sd.u.addr = get_reg (a0);
      break;
    case 0x7:
      sd.u.addr = get_reg (a1);
      break;
    case 0x8:
      sd.u.addr = get_reg (a0) + disp8 ();
      break;
    case 0x9:
      sd.u.addr = get_reg (a1) + disp8 ();
      break;
    case 0xa:
      sd.u.addr = get_reg (sb) + disp8 ();
      break;
    case 0xb:
      sd.u.addr = get_reg (fb) + sign_ext (disp8 (), 8);
      break;
    case 0xc:
      sd.u.addr = get_reg (a0) + disp20 ();
      break;
    case 0xd:
      sd.u.addr = get_reg (a1) + disp20 ();
      break;
    case 0xe:
      sd.u.addr = get_reg (sb) + disp16 ();
      break;
    case 0xf:
      sd.u.addr = disp16 ();
      break;
    default:
      abort ();
    }
  if (sd.mem)
    sd.u.addr &= addr_mask;
  return sd;
}

srcdest
decode_dest3 (int destcode, int bw)
{
  static char map[8] = { -1, -1, -1, 1, 0, 10, 11, 15 };

  the_bits = bits (destcode, 3);
  return decode_srcdest4 (map[destcode], bw);
}

srcdest
decode_src2 (int srccode, int bw, int d)
{
  static char map[4] = { 0, 10, 11, 15 };

  the_bits = bits (srccode, 2);
  return decode_srcdest4 (srccode ? map[srccode] : 1 - d, bw);
}

static struct
{
  reg_id b_regno;
  reg_id w_regno;
  int is_memory;
  int disp_bytes;
  char *name;
} modes23[] =
{
  {
  a0, a0, 1, 0, "[A0]"},	/* 0 0 0 0 0 */
  {
  a1, a1, 1, 0, "[A1]"},	/* 0 0 0 0 1 */
  {
  a0, a0, 0, 0, "A0"},		/* 0 0 0 1 0 */
  {
  a1, a1, 0, 0, "A1"},		/* 0 0 0 1 1 */
  {
  a0, a0, 1, 1, "dsp:8[A0]"},	/* 0 0 1 0 0 */
  {
  a1, a1, 1, 1, "dsp:8[A1]"},	/* 0 0 1 0 1 */
  {
  sb, sb, 1, 1, "dsp:8[SB]"},	/* 0 0 1 1 0 */
  {
  fb, fb, 1, -1, "dsp:8[FB]"},	/* 0 0 1 1 1 */
  {
  a0, a0, 1, 2, "dsp:16[A0]"},	/* 0 1 0 0 0 */
  {
  a1, a1, 1, 2, "dsp:16[A1]"},	/* 0 1 0 0 1 */
  {
  sb, sb, 1, 2, "dsp:16[SB]"},	/* 0 1 0 1 0 */
  {
  fb, fb, 1, -2, "dsp:16[FB]"},	/* 0 1 0 1 1 */
  {
  a0, a0, 1, 3, "dsp:24[A0]"},	/* 0 1 1 0 0 */
  {
  a1, a1, 1, 3, "dsp:24[A1]"},	/* 0 1 1 0 1 */
  {
  mem, mem, 1, 3, "abs24"},	/* 0 1 1 1 0 */
  {
  mem, mem, 1, 2, "abs16"},	/* 0 1 1 1 1 */
  {
  r0h, r2, 0, 0, "R0H/R2"},	/* 1 0 0 0 0 */
  {
  r1h, r3, 0, 0, "R1H/R3"},	/* 1 0 0 0 1 */
  {
  r0l, r0, 0, 0, "R0L/R0"},	/* 1 0 0 1 0 */
  {
  r1l, r1, 0, 0, "R1L/R1"},	/* 1 0 0 1 1 */
};

static srcdest
decode_sd23 (int bbb, int bb, int bytes, int ind, int add)
{
  srcdest sd;
  int code = (bbb << 2) | bb;

  if (code >= sizeof (modes23) / sizeof (modes23[0]))
    abort ();

  if (trace)
    {
      char *b1 = "";
      char *b2 = "";
      char ad[30];
      if (ind)
	{
	  b1 = "[";
	  b2 = "]";
	}
      if (add)
	sprintf (ad, "%+d", add);
      else
	ad[0] = 0;
      if (!the_bits)
	the_bits = bits (code, 4);
      printf ("decode: %s (%d) : %s%s%s%s\n", the_bits, code, b1,
	      modes23[code].name, ad, b2);
      the_bits = 0;
    }

  sd.bytes = bytes;
  sd.mem = modes23[code].is_memory;
  if (sd.mem)
    {
      if (modes23[code].w_regno == mem)
	sd.u.addr = 0;
      else
	sd.u.addr = get_reg (modes23[code].w_regno);
      switch (modes23[code].disp_bytes)
	{
	case 1:
	  sd.u.addr += disp8 ();
	  break;
	case 2:
	  sd.u.addr += disp16 ();
	  break;
	case -1:
	  sd.u.addr += sign_ext (disp8 (), 8);
	  break;
	case -2:
	  sd.u.addr += sign_ext (disp16 (), 16);
	  break;
	case 3:
	  sd.u.addr += disp24 ();
	  break;
	default:
	  break;
	}
      if (add)
	sd.u.addr += add;
      if (ind)
	sd.u.addr = mem_get_si (sd.u.addr & membus_mask);
      sd.u.addr &= membus_mask;
    }
  else
    {
      sd.u.reg = (bytes > 1) ? modes23[code].w_regno : modes23[code].b_regno;
      if (bytes == 3 || bytes == 4)
	{
	  switch (sd.u.reg)
	    {
	    case r0:
	      sd.u.reg = r2r0;
	      break;
	    case r1:
	      sd.u.reg = r3r1;
	      break;
	    case r2:
	      abort ();
	    case r3:
	      abort ();
	    default:;
	    }
	}

    }
  return sd;
}

srcdest
decode_dest23 (int ddd, int dd, int bytes)
{
  return decode_sd23 (ddd, dd, bytes, dest_indirect, dest_addend);
}

srcdest
decode_src23 (int sss, int ss, int bytes)
{
  return decode_sd23 (sss, ss, bytes, src_indirect, src_addend);
}

srcdest
decode_dest2 (int dd, int bytes)
{
  /* r0l/r0, abs16, dsp:8[SB], dsp:8[FB] */
  static char map[4] = { 0x12, 0x0f, 0x06, 0x07 };

  the_bits = bits (dd, 2);
  return decode_sd23 (map[dd] >> 2, map[dd] & 3, bytes, dest_indirect,
		      dest_addend);
}

srcdest
decode_src3 (int sss, int bytes)
{
  /* r0, r1, a0, a1, r2, r3, N/A, N/A */
  static char map[8] = { 0x12, 0x13, 0x02, 0x03, 0x10, 0x11, 0, 0 };

  the_bits = bits (sss, 3);
  return decode_sd23 (map[sss] >> 2, map[sss] & 3, bytes, src_indirect,
		      src_addend);
}

srcdest
decode_dest1 (int destcode, int bw)
{
  the_bits = bits (destcode, 1);
  return decode_srcdest4 (destcode, bw);
}

srcdest
decode_cr (int crcode)
{
  static int regcode[] = { 0, intbl, intbh, flags, isp, sp, sb, fb };
  srcdest sd;
  sd.mem = 0;
  sd.bytes = 2;
  sd.u.reg = regcode[crcode & 7];
  return sd;
}

srcdest
decode_cr_b (int crcode, int bank)
{
  /* FIXME: intbl, intbh, isp */
  static int regcode[3][8] = {
    {0, 0, flags, 0, 0, 0, 0, 0},
    {intb, sp, sb, fb, 0, 0, 0, isp},
    {0, 0, 0, 0, 0, 0, 0, 0}
  };
  srcdest sd;
  sd.mem = 0;
  sd.bytes = bank ? 3 : 2;
  sd.u.reg = regcode[bank][crcode & 7];
  return sd;
}

srcdest
widen_sd (srcdest sd)
{
  sd.bytes *= 2;
  if (!sd.mem)
    switch (sd.u.reg)
      {
      case r0l:
	sd.u.reg = r0;
	break;
      case r0:
	sd.u.reg = r2r0;
	break;
      case r1l:
	sd.u.reg = r1;
	break;
      case r1:
	sd.u.reg = r3r1;
	break;
      case a0:
	if (A16)
	  sd.u.reg = a1a0;
	break;
      default:
	break;
      }
  return sd;
}

srcdest
reg_sd (reg_id reg)
{
  srcdest rv;
  rv.bytes = reg_bytes[reg];
  rv.mem = 0;
  rv.u.reg = reg;
  return rv;
}

int
get_src (srcdest sd)
{
  int v;
  if (sd.mem)
    {
      switch (sd.bytes)
	{
	case 1:
	  v = mem_get_qi (sd.u.addr);
	  break;
	case 2:
	  v = mem_get_hi (sd.u.addr);
	  break;
	case 3:
	  v = mem_get_psi (sd.u.addr);
	  break;
	case 4:
	  v = mem_get_si (sd.u.addr);
	  break;
	default:
	  abort ();
	}
    }
  else
    {
      v = get_reg (sd.u.reg);
      switch (sd.bytes)
	{
	case 1:
	  v &= 0xff;
	  break;
	case 2:
	  v &= 0xffff;
	  break;
	case 3:
	  v &= 0xffffff;
	  break;
	}
    }
  return v;
}

void
put_dest (srcdest sd, int v)
{
  if (sd.mem)
    {
      switch (sd.bytes)
	{
	case 1:
	  mem_put_qi (sd.u.addr, v);
	  break;
	case 2:
	  mem_put_hi (sd.u.addr, v);
	  break;
	case 3:
	  mem_put_psi (sd.u.addr, v);
	  break;
	case 4:
	  mem_put_si (sd.u.addr, v);
	  break;
	}
    }
  else
    {
      switch (sd.bytes)
	{
	case 1:
	  v &= 0xff;
	  break;
	case 2:
	  v &= 0xffff;
	  break;
	case 3:
	  v &= 0xffffff;
	  break;
	}
      put_reg (sd.u.reg, v);
    }
}

srcdest
decode_bit (int destcode)
{
  srcdest sd;
  int addr = 0;
  static const char *dc_names[] = { "r0", "r1", "r2", "r3",
    "a0", "a1", "[a0]", "[a1]",
    "disp8[a0]", "disp8[a1]", "disp8[sb]", "disp8[fb]",
    "disp16[a0]", "disp16[a1]", "disp16[sb]", "abs16"
  };

  if (trace)
    {
      const char *the_bits = bits (destcode, 4);
      printf ("decode: %s : %s\n", the_bits, dc_names[destcode]);
    }

  switch (destcode)
    {
    case 0:
      sd.u.reg = r0;
      break;
    case 1:
      sd.u.reg = r1;
      break;
    case 2:
      sd.u.reg = r2;
      break;
    case 3:
      sd.u.reg = r3;
      break;
    case 4:
      sd.u.reg = a0;
      break;
    case 5:
      sd.u.reg = a1;
      break;
    case 6:
      addr = get_reg (a0);
      break;
    case 7:
      addr = get_reg (a1);
      break;
    case 8:
      addr = get_reg (a0) + disp8 ();
      break;
    case 9:
      addr = get_reg (a1) + disp8 ();
      break;
    case 10:
      addr = get_reg (sb) * 8 + disp8 ();
      break;
    case 11:
      addr = get_reg (fb) * 8 + sign_ext (disp8 (), 8);
      break;
    case 12:
      addr = get_reg (a0) + disp16 ();
      break;
    case 13:
      addr = get_reg (a1) + disp16 ();
      break;
    case 14:
      addr = get_reg (sb) + disp16 ();
      break;
    case 15:
      addr = disp16 ();
      break;
    }

  if (destcode < 6)
    {
      int d = disp8 ();
      sd.mem = 0;
      sd.mask = 1 << (d & 0x0f);
    }
  else
    {
      addr &= addr_mask;
      sd.mem = 1;
      sd.mask = 1 << (addr & 7);
      sd.u.addr = addr >> 3;
    }
  return sd;
}

srcdest
decode_bit11 (int op0)
{
  srcdest sd;
  sd.mask = 1 << (op0 & 7);
  sd.mem = 1;
  sd.u.addr = get_reg (sb) + disp8 ();
  return sd;
}

int
get_bit (srcdest sd)
{
  int b;
  if (sd.mem)
    b = mem_get_qi (sd.u.addr) & sd.mask;
  else
    b = get_reg (sd.u.reg) & sd.mask;
  return b ? 1 : 0;
}

void
put_bit (srcdest sd, int val)
{
  int b;
  if (sd.mem)
    b = mem_get_qi (sd.u.addr);
  else
    b = get_reg (sd.u.reg);
  if (val)
    b |= sd.mask;
  else
    b &= ~sd.mask;
  if (sd.mem)
    mem_put_qi (sd.u.addr, b);
  else
    put_reg (sd.u.reg, b);
}

int
get_bit2 (srcdest sd, int bit)
{
  int b;
  if (sd.mem)
    b = mem_get_qi (sd.u.addr + (bit >> 3)) & (1 << (bit & 7));
  else
    b = get_reg (sd.u.reg) & (1 << bit);
  return b ? 1 : 0;
}

void
put_bit2 (srcdest sd, int bit, int val)
{
  int b;
  if (sd.mem)
    b = mem_get_qi (sd.u.addr + (bit >> 3));
  else
    b = get_reg (sd.u.reg);
  if (val)
    b |= (1 << (bit & 7));
  else
    b &= ~(1 << (bit & 7));
  if (sd.mem)
    mem_put_qi (sd.u.addr + (bit >> 3), b);
  else
    put_reg (sd.u.reg, b);
}
