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/* Instruction printing code for the OpenRISC 1000
   Copyright (C) 1990, 93, 94, 95, 1998 Free Software Foundation, Inc.
   Contributed by Damjan Lampret <lampret@opencores.org>.
   Modified from a29k port.
 
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.  */
 
#define DEBUG 0
 
#include "dis-asm.h"
#include "opcode/or32.h"
 
#include <ctype.h>
#include <string.h>
#include <stdlib.h>
 
CONST unsigned int num_opcodes = (((sizeof or32_opcodes) / (sizeof or32_opcodes[0])) - 1);
 
#define EXTEND29(x) ((x) & 0x10000000 ? ((x) | 0xf0000000) : ((x)))
 
/* Calculates instruction length in bytes. Either 2 or 4 for OR16
   and always 4 for OR32. */
int insn_len (char *insn)
{
  CONST struct or32_opcode *pinsn;
  char *enc;
  int len = 0;
 
  for(pinsn = or32_opcodes; strlen(pinsn->name); pinsn++) {
    if (strcmp(pinsn->name, insn) == 0) {
      for (enc = pinsn->encoding; *enc != '\0'; enc++)
	if ((*enc == '0') && (*(enc+1) == 'x')) {
	  len += 4;
	  enc += 2;
	}
	else if (!isspace(*enc))
	  len++;
      return len / 8;
    }
  }
  printf("insn_len(%s): Unknown instruction.\n", insn);
  exit(1);
}
 
/* Now find the four bytes of INSN_CH and put them in *INSN.  */
static void
find_bytes_big (insn_ch, insn)
     unsigned char *insn_ch;
     unsigned long *insn;
{
  *insn = ((unsigned long)insn_ch[0] << 24) +
      ((unsigned long)insn_ch[1] << 16) +
      ((unsigned long)insn_ch[2] << 8) +
      (unsigned long)insn_ch[3];
#if DEBUG
      printf("find_bytes_big3: %x\n", *insn);
#endif
}
 
/* Is individual insn's operand signed or unsigned? */
int letter_signed(char l)
{
        struct or32_letter *pletter;
 
        for(pletter = or32_letters; pletter->letter != '\0'; pletter++)
                if (pletter->letter == l)
                        return pletter->sign;
 
        printf("letter_signed(%c): Unknown letter.\n", l);
        return 0;
}
 
/* Number of letters in the individual lettered operand. */
int letter_range(char l)
{
  CONST struct or32_opcode *pinsn;
  char *enc;
  int range = 0;
 
  for(pinsn = or32_opcodes; strlen(pinsn->name); pinsn++) {
    if (strchr(pinsn->encoding,l)) {
      for (enc = pinsn->encoding; *enc != '\0'; enc++)
	if ((*enc == '0') && (*(enc+1) == 'x')) {
	  enc += 2;
	}
	else if (*enc == l)
	  range++;
      return range;
    }
  }
  printf("\nABORT: letter_range(%c): Never used letter.\n", l);
  exit(1);
}
 
static void
find_bytes_little (insn_ch, insn)
     unsigned char *insn_ch;
     unsigned long *insn;
{
  *insn = ((unsigned long)insn_ch[3] << 24) +
      ((unsigned long)insn_ch[2] << 16) +
      ((unsigned long)insn_ch[1] << 8) +
      (unsigned long)insn_ch[0];
}
 
 
typedef void (*find_byte_func_type)
     PARAMS ((unsigned char *, unsigned long *));
 
static unsigned long
or32_extract(param_ch, enc_initial, insn)
     char param_ch;
     char *enc_initial;
     unsigned long insn;
{
  char *enc;
  unsigned long ret = 0;
  int opc_pos = 0;
  int param_pos = 0;
 
  for (enc = enc_initial; *enc != '\0'; enc++)
    if (*enc == param_ch)
      {
	if (enc - 2 >= enc_initial && (*(enc - 2) == '0') && (*(enc - 1) == 'x'))
	  continue;
	else
	  param_pos++;
      }
 
#if DEBUG
  printf("or32_extract: %c %x ", param_ch, param_pos);
#endif
        opc_pos = 32;
        for (enc = enc_initial; *enc != '\0'; )
                if ((*enc == '0') && (*(enc+1) == 'x')) {
                  opc_pos -= 4;
                  if ((param_ch == '0') || (param_ch == '1')) {
                        unsigned long tmp = strtol(enc, NULL, 16);
#if DEBUG
                        printf(" enc=%s, tmp=%x ", enc, tmp);
#endif
                        if (param_ch == '0')
                          tmp = 15 - tmp;
                        ret |= tmp << opc_pos;
                   }
                   enc += 3;
                }
                else if ((*enc == '0') || (*enc == '1')) {
                  opc_pos--;
                  if (param_ch == *enc)
                        ret |= 1 << opc_pos;
                  enc++;
                }
                else if (*enc == param_ch) {
                        opc_pos--;
                        param_pos--;
#if DEBUG
                        printf("\n  ret=%x opc_pos=%x, param_pos=%x\n", ret, opc_pos, param_pos);
#endif
                        ret += ((insn >> opc_pos) & 0x1) << param_pos;
                        if (!param_pos && letter_signed(param_ch) && ret >> (letter_range(param_ch) - 1)) {
#if DEBUG
                           printf("\n  ret=%x opc_pos=%x, param_pos=%x\n", ret, opc_pos, param_pos);
#endif
                           ret |= 0xffffffff << letter_range(param_ch);
#if DEBUG
                           printf("\n  after conversion to signed: ret=%x\n", ret);
#endif
                        }
                        enc++;
                }
                else if (isalpha(*enc)) {
                        opc_pos--;
                        enc++;
                }
                else if (*enc == '-') {
                  opc_pos--;
                  enc++;
                }
                else
                        enc++;
 
#if DEBUG
  printf("ret=%x\n", ret);
#endif
  return ret;
}
 
int
or32_opcode_match (insn, encoding)
     unsigned long insn;
     char *encoding;
{
  unsigned long ones, zeros;
 
#if DEBUG
  printf("or32_opcode_match: %.8lx\n", insn);
#endif    
  ones = or32_extract('1', encoding, insn);
  zeros = or32_extract('0', encoding, insn);
 
#if DEBUG
  printf("ones: %x \n", ones);
  printf("zeros: %x \n", zeros);
#endif
  if ((insn & ones) != ones) {
#if DEBUG
    printf("ret1\n");
#endif
    return 0;
  }
 
  if ((~insn & zeros) != zeros) {
#if DEBUG
    printf("ret2\n");
#endif
    return 0;
  }
 
#if DEBUG
  printf("ret3\n");
#endif
  return 1;
}
 
 
/* Print register to INFO->STREAM. Used only by print_insn. */
 
static void
or32_print_register (param_ch, encoding, insn, info)
     char param_ch;
     char *encoding;
     unsigned long insn;
     struct disassemble_info *info;
{
  int regnum = or32_extract(param_ch, encoding, insn);
 
#if DEBUG
  printf("or32_print_register: %c, %s, %x\n", param_ch, encoding, insn);
#endif  
  if (param_ch == 'A')
    (*info->fprintf_func) (info->stream, "r%d", regnum);
  else if (param_ch == 'B')
                (*info->fprintf_func) (info->stream, "r%d", regnum);
  else if (param_ch == 'S')
                (*info->fprintf_func) (info->stream, "r%d", regnum);
        else if (regnum < 16)
                (*info->fprintf_func) (info->stream, "r%d", regnum);
        else if (regnum < 32)
                (*info->fprintf_func) (info->stream, "r%d", regnum-16);
  else
                (*info->fprintf_func) (info->stream, "X%d", regnum);
}
 
/* Print immediate to INFO->STREAM. Used only by print_insn. */
 
static void
or32_print_immediate (param_ch, encoding, insn, info)
     char param_ch;
     char *encoding;
     unsigned long insn;
     struct disassemble_info *info;
{
  int imm = or32_extract(param_ch, encoding, insn);
 
  if (letter_signed(param_ch))
    (*info->fprintf_func) (info->stream, "0x%x", imm);
/*    (*info->fprintf_func) (info->stream, "%d", imm); */
  else
    (*info->fprintf_func) (info->stream, "0x%x", imm);
}
 
/* Print one instruction from MEMADDR on INFO->STREAM.
   Return the size of the instruction (always 4 on or32).  */
 
static int
print_insn (memaddr, info)
     bfd_vma memaddr;
     struct disassemble_info *info;
{
  /* The raw instruction.  */
  unsigned char insn_ch[4];
 
  /* Address. Will be sign extened 27-bit */
  int addr;
 
  /* The four bytes of the instruction.  */
  unsigned long insn;
 
  find_byte_func_type find_byte_func = (find_byte_func_type)info->private_data;
 
  struct or32_opcode CONST * opcode;
 
  {
    int status =
      (*info->read_memory_func) (memaddr, (bfd_byte *) &insn_ch[0], 4, info);
    if (status != 0)
      {
        (*info->memory_error_func) (status, memaddr, info);
        return -1;
      }
  }
 
  (*find_byte_func) (&insn_ch[0], &insn);
 
  for (opcode = &or32_opcodes[0];
       opcode < &or32_opcodes[num_opcodes];
       ++opcode)
    {
      if (or32_opcode_match (insn, opcode->encoding))
        {
          char *s;
 
          (*info->fprintf_func) (info->stream, "%s ", opcode->name);
          for (s = opcode->args; *s != '\0'; ++s)
            {
              switch (*s)
                {
                case '\0':
                  return 4;
 
                case 'r':
                  or32_print_register(*++s, opcode->encoding, insn, info);
                  break;
 
                case 'X':
                  addr = or32_extract ('X', opcode->encoding, insn) << 2;
 
                  /* Calulate the correct address.  XXX is this really correct ?? */
                  addr = memaddr + EXTEND29(addr);
 
                  (*info->print_address_func)
                    (addr, info);
                  break;
 
                default:
                  if (strchr (opcode->encoding, *s))
                    or32_print_immediate (*s, opcode->encoding, insn, info);
                  else
                    (*info->fprintf_func) (info->stream, "%c", *s);
                }
            }
 
          return 4;
        }
    }
 
  /* This used to be %8x for binutils.  */
  (*info->fprintf_func)
    (info->stream, ".word 0x%08x", insn);
  return 4;
}
 
/* Disassemble a big-endian or32 instruction.  */
int
print_insn_big_or32 (memaddr, info)
     bfd_vma memaddr;
     struct disassemble_info *info;
{
  info->private_data = (PTR) find_bytes_big;
  return print_insn (memaddr, info);
}
 
/* Disassemble a little-endian or32 instruction.  */
int
print_insn_little_or32 (memaddr, info)
     bfd_vma memaddr;
     struct disassemble_info *info;
{
  info->private_data = (PTR) find_bytes_little;
  return print_insn (memaddr, info);
}