/* reg.c --- register set model for RX simulator.

   Copyright (C) 2005, 2007, 2008, 2009 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 <string.h>

#include "cpu.h"
#include "bfd.h"
#include "trace.h"

int verbose = 0;
int trace = 0;
int enable_counting = 0;

int rx_in_gdb = 1;

int rx_flagmask;
int rx_flagand;
int rx_flagor;

int rx_big_endian;
regs_type regs;
int step_result;
unsigned int heapbottom = 0;
unsigned int heaptop = 0;

char *reg_names[] = {
  /* general registers */
  "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
  "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
  /* control register */
  "psw", "pc", "usp", "fpsw", "RES", "RES", "RES", "RES",
  "bpsw", "bpc", "isp", "fintv", "intb", "RES", "RES", "RES",
  "RES", "RES", "RES", "RES", "RES", "RES", "RES", "RES",
  "RES", "RES", "RES", "RES", "RES", "RES", "RES", "RES",
  "temp", "acc", "acchi", "accmi", "acclo"
};

unsigned int b2mask[] = { 0, 0xff, 0xffff, 0xffffff, 0xffffffff };
unsigned int b2signbit[] = { 0, (1 << 7), (1 << 15), (1 << 24), (1 << 31) };
int b2maxsigned[] = { 0, 0x7f, 0x7fff, 0x7fffff, 0x7fffffff };
int b2minsigned[] = { 0, -128, -32768, -8388608, -2147483647 - 1 };

static regs_type oldregs;

void
init_regs (void)
{
  memset (&regs, 0, sizeof (regs));
  memset (&oldregs, 0, sizeof (oldregs));
}

static unsigned int
get_reg_i (int id)
{
  if (id == 0)
    return regs.r_psw & FLAGBIT_U ? regs.r_usp : regs.r_isp;

  if (id >= 1 && id <= 15)
    return regs.r[id];

  switch (id)
    {
    case psw:
      return regs.r_psw;
    case fpsw:
      return regs.r_fpsw;
    case isp:
      return regs.r_isp;
    case usp:
      return regs.r_usp;
    case bpc:
      return regs.r_bpc;
    case bpsw:
      return regs.r_bpsw;
    case fintv:
      return regs.r_fintv;
    case intb:
      return regs.r_intb;
    case pc:
      return regs.r_pc;
    case r_temp_idx:
      return regs.r_temp;
    case acchi:
      return (SI)(regs.r_acc >> 32);
    case accmi:
      return (SI)(regs.r_acc >> 16);
    case acclo:
      return (SI)regs.r_acc;
    }
  abort();
}

unsigned int
get_reg (int id)
{
  unsigned int rv = get_reg_i (id);
  if (trace > ((id != pc && id != sp) ? 0 : 1))
    printf ("get_reg (%s) = %08x\n", reg_names[id], rv);
  return rv;
}

static unsigned long long
get_reg64_i (int id)
{
  switch (id)
    {
    case acc64:
      return regs.r_acc;
    default:
      abort ();
    }
}

unsigned long long
get_reg64 (int id)
{
  unsigned long long rv = get_reg64_i (id);
  if (trace > ((id != pc && id != sp) ? 0 : 1))
    printf ("get_reg (%s) = %016llx\n", reg_names[id], rv);
  return rv;
}

static int highest_sp = 0, lowest_sp = 0xffffff;

void
stack_heap_stats ()
{
  if (heapbottom < heaptop)
    printf ("heap:  %08x - %08x (%d bytes)\n", heapbottom, heaptop,
	    heaptop - heapbottom);
  if (lowest_sp < highest_sp)
    printf ("stack: %08x - %08x (%d bytes)\n", lowest_sp, highest_sp,
	    highest_sp - lowest_sp);
}

void
put_reg (int id, unsigned int v)
{
  if (trace > ((id != pc) ? 0 : 1))
    printf ("put_reg (%s) = %08x\n", reg_names[id], v);


  switch (id)
    {
    case psw:
      regs.r_psw = v;
      break;
    case fpsw:
      {
	SI anded;
	/* This is an odd one - The Cx flags are AND'd, and the FS flag
	   is synthetic.  */
	anded = regs.r_fpsw & v;
	anded |= ~ FPSWBITS_CMASK;
	regs.r_fpsw = v & anded;
	if (regs.r_fpsw & FPSWBITS_FMASK)
	  regs.r_fpsw |= FPSWBITS_FSUM;
	else
	  regs.r_fpsw &= ~FPSWBITS_FSUM;
      }
      break;
    case isp:
      regs.r_isp = v;
      break;
    case usp:
      regs.r_usp = v;
      break;
    case bpc:
      regs.r_bpc = v;
      break;
    case bpsw:
      regs.r_bpsw = v;
      break;
    case fintv:
      regs.r_fintv = v;
      break;
    case intb:
      regs.r_intb = v;
      break;
    case pc:
      regs.r_pc = v;
      break;

    case acchi:
      regs.r_acc = (regs.r_acc & 0xffffffffULL) | ((DI)v << 32);
      break;
    case accmi:
      regs.r_acc = (regs.r_acc & ~0xffffffff0000ULL) | ((DI)v << 16);
      break;
    case acclo:
      regs.r_acc = (regs.r_acc & ~0xffffffffULL) | ((DI)v);
      break;

    case 0: /* Stack pointer is "in" R0.  */
      {
	if (v < heaptop)
	  {
	    unsigned int line;
	    const char * dummy;
	    const char * fname = NULL;

	    sim_get_current_source_location (& dummy, & fname, &line);

	    /* The setjmp and longjmp functions play tricks with the stack pointer.  */
	    if (fname == NULL
		|| (strcmp (fname, "_setjmp") != 0
		    && strcmp (fname, "_longjmp") != 0))
	      {
		printf ("collision in %s: pc %08x heap %08x stack %08x\n",
			fname, (unsigned int) regs.r_pc, heaptop, v);
		exit (1);
	      }
	  }
	else
	  {
	    if (v < lowest_sp)
	      lowest_sp = v;
	    if (v > highest_sp)
	      highest_sp = v;
	  }

	if (regs.r_psw & FLAGBIT_U)
	  regs.r_usp = v;
	else
	  regs.r_isp = v;
	break;
      }

    default:
      if (id >= 1 || id <= 15)
	regs.r[id] = v;
      else
	abort ();
    }
}

void
put_reg64 (int id, unsigned long long v)
{
  if (trace > ((id != pc) ? 0 : 1))
    printf ("put_reg (%s) = %016llx\n", reg_names[id], v);

  switch (id)
    {
    case acc64:
      regs.r_acc = v;
      break;
    default:
      abort ();
    }
}

int
condition_true (int cond_id)
{
  int f;

  static const char *cond_name[] = {
    "Z",
    "!Z",
    "C",
    "!C",
    "C&!Z",
    "!(C&!Z)",
    "!S",
    "S",
    "!(S^O)",
    "S^O",
    "!((S^O)|Z)",
    "(S^O)|Z",
    "O",
    "!O",
    "always",
    "never"
  };
  switch (cond_id & 15)
    {
    case 0:
      f = FLAG_Z;
      break;		/* EQ/Z */
    case 1:
      f = !FLAG_Z;
      break;		/* NE/NZ */
    case 2:
      f = FLAG_C;
      break;		/* GEU/C */
    case 3:
      f = !FLAG_C;
      break;		/* LTU/NC */
    case 4:
      f = FLAG_C & !FLAG_Z;
      break;		/* GTU */
    case 5:
      f = !(FLAG_C & !FLAG_Z);
      break;		/* LEU */
    case 6:
      f = !FLAG_S;
      break;		/* PZ */
    case 7:
      f = FLAG_S;
      break;		/* N */

    case 8:
      f = !(FLAG_S ^ FLAG_O);
      break;		/* GE */
    case 9:
      f = FLAG_S ^ FLAG_O;
      break;		/* LT */
    case 10:
      f = !((FLAG_S ^ FLAG_O) | FLAG_Z);
      break;		/* GT */
    case 11:
      f = (FLAG_S ^ FLAG_O) | FLAG_Z;
      break;		/* LE */
    case 12:
      f = FLAG_O;
      break;		/* O */
    case 13:
      f = !FLAG_O;
      break;		/* NO */
    case 14:
      f = 1;		/* always */
      break;
    default:
      f = 0;		/* never */
      break;
    }
  if (trace && ((cond_id & 15) != 14))
    printf ("cond[%d] %s = %s\n", cond_id, cond_name[cond_id & 15],
	    f ? "true" : "false");
  return f;
}

void
set_flags (int mask, int newbits)
{
  regs.r_psw &= rx_flagand;
  regs.r_psw |= rx_flagor;
  regs.r_psw |= (newbits & mask & rx_flagmask);

  if (trace)
    {
      int i;
      printf ("flags now \033[32m %d", (int)((regs.r_psw >> 24) & 7));
      for (i = 17; i >= 0; i--)
	if (0x3000f & (1 << i))
	  {
	    if (regs.r_psw & (1 << i))
	      putchar ("CZSO------------IU"[i]);
	    else
	      putchar ('-');
	  }
      printf ("\033[0m\n");
    }
}

void
set_oszc (long long value, int b, int c)
{
  int mask = b2mask[b];
  int f = 0;

  if (c)
    f |= FLAGBIT_C;
  if ((value & mask) == 0)
    f |= FLAGBIT_Z;
  if (value & b2signbit[b])
    f |= FLAGBIT_S;
  if ((value > b2maxsigned[b]) || (value < b2minsigned[b]))
    f |= FLAGBIT_O;
  set_flags (FLAGBIT_Z | FLAGBIT_S | FLAGBIT_O | FLAGBIT_C, f);
}

void
set_szc (long long value, int b, int c)
{
  int mask = b2mask[b];
  int f = 0;

  if (c)
    f |= FLAGBIT_C;
  if ((value & mask) == 0)
    f |= FLAGBIT_Z;
  if (value & b2signbit[b])
    f |= FLAGBIT_S;
  set_flags (FLAGBIT_Z | FLAGBIT_S | FLAGBIT_C, f);
}

void
set_osz (long long value, int b)
{
  int mask = b2mask[b];
  int f = 0;

  if ((value & mask) == 0)
    f |= FLAGBIT_Z;
  if (value & b2signbit[b])
    f |= FLAGBIT_S;
  if ((value > b2maxsigned[b]) || (value < b2minsigned[b]))
    f |= FLAGBIT_O;
  set_flags (FLAGBIT_Z | FLAGBIT_S | FLAGBIT_O, f);
}

void
set_sz (long long value, int b)
{
  int mask = b2mask[b];
  int f = 0;

  if ((value & mask) == 0)
    f |= FLAGBIT_Z;
  if (value & b2signbit[b])
    f |= FLAGBIT_S;
  set_flags (FLAGBIT_Z | FLAGBIT_S, f);
}

void
set_zc (int z, int c)
{
  set_flags (FLAGBIT_C | FLAGBIT_Z,
	     (c ? FLAGBIT_C : 0) | (z ? FLAGBIT_Z : 0));
}

void
set_c (int c)
{
  set_flags (FLAGBIT_C, c ? FLAGBIT_C : 0);
}

static char *
psw2str(int rpsw)
{
  static char buf[10];
  char *bp = buf;
  int i, ipl;

  ipl = (rpsw & FLAGBITS_IPL) >> FLAGSHIFT_IPL;
  if (ipl > 9)
    {
      *bp++ = (ipl / 10) + '0';
      ipl %= 10;
    }
  *bp++ = ipl + '0';
  for (i = 20; i >= 0; i--)
    if (0x13000f & (1 << i))
      {
	if (rpsw & (1 << i))
	  *bp++ = "CZSO------------IU--P"[i];
	else
	  *bp++ = '-';
      }
  *bp = 0;
  return buf;
}

static char *
fpsw2str(int rpsw)
{
  static char buf[100];
  char *bp = buf;
  int i;	/*   ---+---+---+---+---+---+---+---+ */
  const char s1[] = "FFFFFF-----------EEEEE-DCCCCCCRR";
  const char s2[] = "SXUZOV-----------XUZOV-NEXUZOV01";
  const char rm[4][3] = { "RC", "RZ", "RP", "RN" };

  for (i = 31; i >= 0; i--)
    if (0xfc007dfc & (1 << i))
      {
	if (rpsw & (1 << i))
	  {
	    if (bp > buf)
	      *bp++ = '.';
	    *bp++ = s1[31-i];
	    *bp++ = s2[31-i];
	  }
      }
  if (bp > buf)
    *bp++ = '.';
  strcpy (bp, rm[rpsw&3]);
  return buf;
}

#define TRC(f,n) \
  if (oldregs.f != regs.f) \
    { \
      if (tag) { printf (tag); tag = 0; } \
      printf("  %s %08x:%08x", n, \
	     (unsigned int)oldregs.f, \
	     (unsigned int)regs.f); \
      oldregs.f = regs.f; \
    }

void
trace_register_changes (void)
{
  char *tag = "\033[36mREGS:";
  int i;

  if (!trace)
    return;
  for (i=1; i<16; i++)
    TRC (r[i], reg_names[i]);
  TRC (r_intb, "intb");
  TRC (r_usp, "usp");
  TRC (r_isp, "isp");
  if (oldregs.r_psw != regs.r_psw)
    {
      if (tag) { printf (tag); tag = 0; }
      printf("  psw %s:", psw2str(oldregs.r_psw));
      printf("%s", psw2str(regs.r_psw));
      oldregs.r_psw = regs.r_psw;
    }

  if (oldregs.r_fpsw != regs.r_fpsw)
    {
      if (tag) { printf (tag); tag = 0; }
      printf("  fpsw %s:", fpsw2str(oldregs.r_fpsw));
      printf("%s", fpsw2str(regs.r_fpsw));
      oldregs.r_fpsw = regs.r_fpsw;
    }

  if (oldregs.r_acc != regs.r_acc)
    {
      if (tag) { printf (tag); tag = 0; }
      printf("  acc %016llx:", oldregs.r_acc);
      printf("%016llx", regs.r_acc);
      oldregs.r_acc = regs.r_acc;
    }

  if (tag == 0)
    printf ("\033[0m\n");
}