/* Disassembly routines for TMS320C30 architecture
  Copyright (C) 1998-2024 Free Software Foundation, Inc.
  Contributed by Steven Haworth ([email protected])

  This file is part of the GNU opcodes library.

  This library 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, or (at your option)
  any later version.

  It 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 file; see the file COPYING.  If not, write to the
  Free Software Foundation, 51 Franklin Street - Fifth Floor, Boston,
  MA 02110-1301, USA.  */

#include "sysdep.h"
#include <errno.h>
#include <math.h>
#include "disassemble.h"
#include "opcode/tic30.h"

#define NORMAL_INSN   1
#define PARALLEL_INSN 2

/* Gets the type of instruction based on the top 2 or 3 bits of the
  instruction word.  */
#define GET_TYPE(insn) (insn & 0x80000000 ? insn & 0xC0000000 : insn & 0xE0000000)

/* Instruction types.  */
#define TWO_OPERAND_1 0x00000000
#define TWO_OPERAND_2 0x40000000
#define THREE_OPERAND 0x20000000
#define PAR_STORE     0xC0000000
#define MUL_ADDS      0x80000000
#define BRANCHES      0x60000000

/* Specific instruction id bits.  */
#define NORMAL_IDEN    0x1F800000
#define PAR_STORE_IDEN 0x3E000000
#define MUL_ADD_IDEN   0x2C000000
#define BR_IMM_IDEN    0x1F000000
#define BR_COND_IDEN   0x1C3F0000

/* Addressing modes.  */
#define AM_REGISTER 0x00000000
#define AM_DIRECT   0x00200000
#define AM_INDIRECT 0x00400000
#define AM_IMM      0x00600000

#define P_FIELD 0x03000000

#define REG_AR0 0x08
#define LDP_INSN 0x08700000

/* TMS320C30 program counter for current instruction.  */
static unsigned int _pc;

struct instruction
{
 int type;
 insn_template *tm;
 partemplate *ptm;
};

static int
get_tic30_instruction (unsigned long insn_word, struct instruction *insn)
{
 switch (GET_TYPE (insn_word))
   {
   case TWO_OPERAND_1:
   case TWO_OPERAND_2:
   case THREE_OPERAND:
     insn->type = NORMAL_INSN;
     {
       insn_template *current_optab = (insn_template *) tic30_optab;

       for (; current_optab < tic30_optab_end; current_optab++)
         {
           if (GET_TYPE (current_optab->base_opcode) == GET_TYPE (insn_word))
             {
               if (current_optab->operands == 0)
                 {
                   if (current_optab->base_opcode == insn_word)
                     {
                       insn->tm = current_optab;
                       break;
                     }
                 }
               else if ((current_optab->base_opcode & NORMAL_IDEN) == (insn_word & NORMAL_IDEN))
                 {
                   insn->tm = current_optab;
                   break;
                 }
             }
         }
     }
     break;

   case PAR_STORE:
     insn->type = PARALLEL_INSN;
     {
       partemplate *current_optab = (partemplate *) tic30_paroptab;

       for (; current_optab < tic30_paroptab_end; current_optab++)
         {
           if (GET_TYPE (current_optab->base_opcode) == GET_TYPE (insn_word))
             {
               if ((current_optab->base_opcode & PAR_STORE_IDEN)
                   == (insn_word & PAR_STORE_IDEN))
                 {
                   insn->ptm = current_optab;
                   break;
                 }
             }
         }
     }
     break;

   case MUL_ADDS:
     insn->type = PARALLEL_INSN;
     {
       partemplate *current_optab = (partemplate *) tic30_paroptab;

       for (; current_optab < tic30_paroptab_end; current_optab++)
         {
           if (GET_TYPE (current_optab->base_opcode) == GET_TYPE (insn_word))
             {
               if ((current_optab->base_opcode & MUL_ADD_IDEN)
                   == (insn_word & MUL_ADD_IDEN))
                 {
                   insn->ptm = current_optab;
                   break;
                 }
             }
         }
     }
     break;

   case BRANCHES:
     insn->type = NORMAL_INSN;
     {
       insn_template *current_optab = (insn_template *) tic30_optab;

       for (; current_optab < tic30_optab_end; current_optab++)
         {
           if (GET_TYPE (current_optab->base_opcode) == GET_TYPE (insn_word))
             {
               if (current_optab->operand_types[0] & Imm24)
                 {
                   if ((current_optab->base_opcode & BR_IMM_IDEN)
                       == (insn_word & BR_IMM_IDEN))
                     {
                       insn->tm = current_optab;
                       break;
                     }
                 }
               else if (current_optab->operands > 0)
                 {
                   if ((current_optab->base_opcode & BR_COND_IDEN)
                       == (insn_word & BR_COND_IDEN))
                     {
                       insn->tm = current_optab;
                       break;
                     }
                 }
               else
                 {
                   if ((current_optab->base_opcode & (BR_COND_IDEN | 0x00800000))
                       == (insn_word & (BR_COND_IDEN | 0x00800000)))
                     {
                       insn->tm = current_optab;
                       break;
                     }
                 }
             }
         }
     }
     break;
   default:
     return 0;
   }
 return 1;
}

#define OPERAND_BUFFER_LEN 15

static int
get_register_operand (unsigned char fragment, char *buffer)
{
 const reg *current_reg = tic30_regtab;

 if (buffer == NULL)
   return 0;
 for (; current_reg < tic30_regtab_end; current_reg++)
   {
     if ((fragment & 0x1F) == current_reg->opcode)
       {
         strncpy (buffer, current_reg->name, OPERAND_BUFFER_LEN - 1);
         buffer[OPERAND_BUFFER_LEN - 1] = 0;
         return 1;
       }
   }
 return 0;
}

static int
get_indirect_operand (unsigned short fragment,
                     int size,
                     char *buffer)
{
 unsigned char mod;
 unsigned arnum;
 unsigned char disp;

 if (buffer == NULL)
   return 0;
 /* Determine which bits identify the sections of the indirect
    operand based on the size in bytes.  */
 switch (size)
   {
   case 1:
     mod = (fragment & 0x00F8) >> 3;
     arnum = (fragment & 0x0007);
     disp = 0;
     break;
   case 2:
     mod = (fragment & 0xF800) >> 11;
     arnum = (fragment & 0x0700) >> 8;
     disp = (fragment & 0x00FF);
     break;
   default:
     return 0;
   }
 {
   const ind_addr_type *current_ind = tic30_indaddr_tab;

   for (; current_ind < tic30_indaddrtab_end; current_ind++)
     {
       if (current_ind->modfield == mod)
         {
           if (current_ind->displacement == IMPLIED_DISP && size == 2)
             continue;

           else
             {
               size_t i, len;
               int bufcnt;

               len = strlen (current_ind->syntax);

               for (i = 0, bufcnt = 0; i < len; i++, bufcnt++)
                 {
                   buffer[bufcnt] = current_ind->syntax[i];

                   if (bufcnt > 0
                       && bufcnt < OPERAND_BUFFER_LEN - 1
                       && buffer[bufcnt - 1] == 'a'
                       && buffer[bufcnt] == 'r')
                     buffer[++bufcnt] = arnum + '0';

                   if (bufcnt < OPERAND_BUFFER_LEN - 1
                       && buffer[bufcnt] == '('
                       && current_ind->displacement == DISP_REQUIRED)
                     {
                       snprintf (buffer + (bufcnt + 1),
                                OPERAND_BUFFER_LEN - (bufcnt + 1),
                                "%u", disp);
                       bufcnt += strlen (buffer + (bufcnt + 1));
                     }
                 }
               buffer[bufcnt + 1] = '\0';
               break;
             }
         }
     }
 }
 return 1;
}

static int
cnvt_tmsfloat_ieee (unsigned long tmsfloat, int size, float *ieeefloat)
{
 unsigned long exponent, sign, mant;
 union
 {
   unsigned long l;
   float f;
 } val;

 if (size == 2)
   {
     if ((tmsfloat & 0x0000F000) == 0x00008000)
       tmsfloat = 0x80000000;
     else
       {
         tmsfloat <<= 16;
         tmsfloat = (long) tmsfloat >> 4;
       }
   }
 exponent = tmsfloat & 0xFF000000;
 if (exponent == 0x80000000)
   {
     *ieeefloat = 0.0;
     return 1;
   }
 exponent += 0x7F000000;
 sign = (tmsfloat & 0x00800000) << 8;
 mant = tmsfloat & 0x007FFFFF;
 if (exponent == 0xFF000000)
   {
     if (mant == 0)
       *ieeefloat = ERANGE;
#ifdef HUGE_VALF
     if (sign == 0)
       *ieeefloat = HUGE_VALF;
     else
       *ieeefloat = -HUGE_VALF;
#else
     if (sign == 0)
       *ieeefloat = 1.0 / 0.0;
     else
       *ieeefloat = -1.0 / 0.0;
#endif
     return 1;
   }
 exponent >>= 1;
 if (sign)
   {
     mant = (~mant) & 0x007FFFFF;
     mant += 1;
     exponent += mant & 0x00800000;
     exponent &= 0x7F800000;
     mant &= 0x007FFFFF;
   }
 if (tmsfloat == 0x80000000)
   sign = mant = exponent = 0;
 tmsfloat = sign | exponent | mant;
 val.l = tmsfloat;
 *ieeefloat = val.f;
 return 1;
}

static int
print_two_operand (disassemble_info *info,
                  unsigned long insn_word,
                  struct instruction *insn)
{
 char name[12];
 char operand[2][OPERAND_BUFFER_LEN] =
 {
   {0},
   {0}
 };
 float f_number;

 if (insn->tm == NULL)
   return 0;
 strcpy (name, insn->tm->name);
 if (insn->tm->opcode_modifier == AddressMode)
   {
     int src_op, dest_op;
     /* Determine whether instruction is a store or a normal instruction.  */
     if ((insn->tm->operand_types[1] & (Direct | Indirect))
         == (Direct | Indirect))
       {
         src_op = 1;
         dest_op = 0;
       }
     else
       {
         src_op = 0;
         dest_op = 1;
       }
     /* Get the destination register.  */
     if (insn->tm->operands == 2)
       get_register_operand ((insn_word & 0x001F0000) >> 16, operand[dest_op]);
     /* Get the source operand based on addressing mode.  */
     switch (insn_word & AddressMode)
       {
       case AM_REGISTER:
         /* Check for the NOP instruction before getting the operand.  */
         if ((insn->tm->operand_types[0] & NotReq) == 0)
           get_register_operand ((insn_word & 0x0000001F), operand[src_op]);
         break;
       case AM_DIRECT:
         sprintf (operand[src_op], "@0x%lX", (insn_word & 0x0000FFFF));
         break;
       case AM_INDIRECT:
         get_indirect_operand ((insn_word & 0x0000FFFF), 2, operand[src_op]);
         break;
       case AM_IMM:
         /* Get the value of the immediate operand based on variable type.  */
         switch (insn->tm->imm_arg_type)
           {
           case Imm_Float:
             cnvt_tmsfloat_ieee ((insn_word & 0x0000FFFF), 2, &f_number);
             sprintf (operand[src_op], "%2.2f", f_number);
             break;
           case Imm_SInt:
             sprintf (operand[src_op], "%d", (short) (insn_word & 0x0000FFFF));
             break;
           case Imm_UInt:
             sprintf (operand[src_op], "%lu", (insn_word & 0x0000FFFF));
             break;
           default:
             return 0;
           }
         /* Handle special case for LDP instruction.  */
         if ((insn_word & 0xFFFFFF00) == LDP_INSN)
           {
             strcpy (name, "ldp");
             sprintf (operand[0], "0x%06lX", (insn_word & 0x000000FF) << 16);
             operand[1][0] = '\0';
           }
       }
   }
 /* Handle case for stack and rotate instructions.  */
 else if (insn->tm->operands == 1)
   {
     if (insn->tm->opcode_modifier == StackOp)
       get_register_operand ((insn_word & 0x001F0000) >> 16, operand[0]);
   }
 /* Output instruction to stream.  */
 info->fprintf_func (info->stream, "   %s %s%c%s", name,
                     operand[0][0] ? operand[0] : "",
                     operand[1][0] ? ',' : ' ',
                     operand[1][0] ? operand[1] : "");
 return 1;
}

static int
print_three_operand (disassemble_info *info,
                    unsigned long insn_word,
                    struct instruction *insn)
{
 char operand[3][OPERAND_BUFFER_LEN] =
 {
   {0},
   {0},
   {0}
 };

 if (insn->tm == NULL)
   return 0;
 switch (insn_word & AddressMode)
   {
   case AM_REGISTER:
     get_register_operand ((insn_word & 0x000000FF), operand[0]);
     get_register_operand ((insn_word & 0x0000FF00) >> 8, operand[1]);
     break;
   case AM_DIRECT:
     get_register_operand ((insn_word & 0x000000FF), operand[0]);
     get_indirect_operand ((insn_word & 0x0000FF00) >> 8, 1, operand[1]);
     break;
   case AM_INDIRECT:
     get_indirect_operand ((insn_word & 0x000000FF), 1, operand[0]);
     get_register_operand ((insn_word & 0x0000FF00) >> 8, operand[1]);
     break;
   case AM_IMM:
     get_indirect_operand ((insn_word & 0x000000FF), 1, operand[0]);
     get_indirect_operand ((insn_word & 0x0000FF00) >> 8, 1, operand[1]);
     break;
   default:
     return 0;
   }
 if (insn->tm->operands == 3)
   get_register_operand ((insn_word & 0x001F0000) >> 16, operand[2]);
 info->fprintf_func (info->stream, "   %s %s,%s%c%s", insn->tm->name,
                     operand[0], operand[1],
                     operand[2][0] ? ',' : ' ',
                     operand[2][0] ? operand[2] : "");
 return 1;
}

static int
print_par_insn (disassemble_info *info,
               unsigned long insn_word,
               struct instruction *insn)
{
 size_t i, len;
 char *name1, *name2;
 char operand[2][3][OPERAND_BUFFER_LEN] =
 {
   {
     {0},
     {0},
     {0}
   },
   {
     {0},
     {0},
     {0}
   }
 };

 if (insn->ptm == NULL)
   return 0;
 /* Parse out the names of each of the parallel instructions from the
    q_insn1_insn2 format.  */
 name1 = (char *) strdup (insn->ptm->name + 2);
 name2 = "";
 len = strlen (name1);
 for (i = 0; i < len; i++)
   {
     if (name1[i] == '_')
       {
         name2 = &name1[i + 1];
         name1[i] = '\0';
         break;
       }
   }
 /* Get the operands of the instruction based on the operand order.  */
 switch (insn->ptm->oporder)
   {
   case OO_4op1:
     get_indirect_operand ((insn_word & 0x000000FF), 1, operand[0][0]);
     get_indirect_operand ((insn_word & 0x0000FF00) >> 8, 1, operand[1][1]);
     get_register_operand ((insn_word >> 16) & 0x07, operand[1][0]);
     get_register_operand ((insn_word >> 22) & 0x07, operand[0][1]);
     break;
   case OO_4op2:
     get_indirect_operand ((insn_word & 0x000000FF), 1, operand[0][0]);
     get_indirect_operand ((insn_word & 0x0000FF00) >> 8, 1, operand[1][0]);
     get_register_operand ((insn_word >> 19) & 0x07, operand[1][1]);
     get_register_operand ((insn_word >> 22) & 0x07, operand[0][1]);
     break;
   case OO_4op3:
     get_indirect_operand ((insn_word & 0x000000FF), 1, operand[0][1]);
     get_indirect_operand ((insn_word & 0x0000FF00) >> 8, 1, operand[1][1]);
     get_register_operand ((insn_word >> 16) & 0x07, operand[1][0]);
     get_register_operand ((insn_word >> 22) & 0x07, operand[0][0]);
     break;
   case OO_5op1:
     get_indirect_operand ((insn_word & 0x000000FF), 1, operand[0][0]);
     get_indirect_operand ((insn_word & 0x0000FF00) >> 8, 1, operand[1][1]);
     get_register_operand ((insn_word >> 16) & 0x07, operand[1][0]);
     get_register_operand ((insn_word >> 19) & 0x07, operand[0][1]);
     get_register_operand ((insn_word >> 22) & 0x07, operand[0][2]);
     break;
   case OO_5op2:
     get_indirect_operand ((insn_word & 0x000000FF), 1, operand[0][1]);
     get_indirect_operand ((insn_word & 0x0000FF00) >> 8, 1, operand[1][1]);
     get_register_operand ((insn_word >> 16) & 0x07, operand[1][0]);
     get_register_operand ((insn_word >> 19) & 0x07, operand[0][0]);
     get_register_operand ((insn_word >> 22) & 0x07, operand[0][2]);
     break;
   case OO_PField:
     if (insn_word & 0x00800000)
       get_register_operand (0x01, operand[0][2]);
     else
       get_register_operand (0x00, operand[0][2]);
     if (insn_word & 0x00400000)
       get_register_operand (0x03, operand[1][2]);
     else
       get_register_operand (0x02, operand[1][2]);
     switch (insn_word & P_FIELD)
       {
       case 0x00000000:
         get_indirect_operand ((insn_word & 0x000000FF), 1, operand[0][1]);
         get_indirect_operand ((insn_word & 0x0000FF00) >> 8, 1, operand[0][0]);
         get_register_operand ((insn_word >> 16) & 0x07, operand[1][1]);
         get_register_operand ((insn_word >> 19) & 0x07, operand[1][0]);
         break;
       case 0x01000000:
         get_indirect_operand ((insn_word & 0x000000FF), 1, operand[1][0]);
         get_indirect_operand ((insn_word & 0x0000FF00) >> 8, 1, operand[0][0]);
         get_register_operand ((insn_word >> 16) & 0x07, operand[1][1]);
         get_register_operand ((insn_word >> 19) & 0x07, operand[0][1]);
         break;
       case 0x02000000:
         get_indirect_operand ((insn_word & 0x000000FF), 1, operand[1][1]);
         get_indirect_operand ((insn_word & 0x0000FF00) >> 8, 1, operand[1][0]);
         get_register_operand ((insn_word >> 16) & 0x07, operand[0][1]);
         get_register_operand ((insn_word >> 19) & 0x07, operand[0][0]);
         break;
       case 0x03000000:
         get_indirect_operand ((insn_word & 0x000000FF), 1, operand[1][1]);
         get_indirect_operand ((insn_word & 0x0000FF00) >> 8, 1, operand[0][0]);
         get_register_operand ((insn_word >> 16) & 0x07, operand[1][0]);
         get_register_operand ((insn_word >> 19) & 0x07, operand[0][1]);
         break;
       }
     break;
   default:
     return 0;
   }
 info->fprintf_func (info->stream, "   %s %s,%s%c%s", name1,
                     operand[0][0], operand[0][1],
                     operand[0][2][0] ? ',' : ' ',
                     operand[0][2][0] ? operand[0][2] : "");
 info->fprintf_func (info->stream, "\n\t\t\t|| %s %s,%s%c%s", name2,
                     operand[1][0], operand[1][1],
                     operand[1][2][0] ? ',' : ' ',
                     operand[1][2][0] ? operand[1][2] : "");
 free (name1);
 return 1;
}

static int
print_branch (disassemble_info *info,
             unsigned long insn_word,
             struct instruction *insn)
{
 char operand[2][OPERAND_BUFFER_LEN] =
 {
   {0},
   {0}
 };
 unsigned long address;
 int print_label = 0;

 if (insn->tm == NULL)
   return 0;
 /* Get the operands for 24-bit immediate jumps.  */
 if (insn->tm->operand_types[0] & Imm24)
   {
     address = insn_word & 0x00FFFFFF;
     sprintf (operand[0], "0x%lX", address);
     print_label = 1;
   }
 /* Get the operand for the trap instruction.  */
 else if (insn->tm->operand_types[0] & IVector)
   {
     address = insn_word & 0x0000001F;
     sprintf (operand[0], "0x%lX", address);
   }
 else
   {
     address = insn_word & 0x0000FFFF;
     /* Get the operands for the DB instructions.  */
     if (insn->tm->operands == 2)
       {
         get_register_operand (((insn_word & 0x01C00000) >> 22) + REG_AR0, operand[0]);
         if (insn_word & PCRel)
           {
             sprintf (operand[1], "%d", (short) address);
             print_label = 1;
           }
         else
           get_register_operand (insn_word & 0x0000001F, operand[1]);
       }
     /* Get the operands for the standard branches.  */
     else if (insn->tm->operands == 1)
       {
         if (insn_word & PCRel)
           {
             address = (short) address;
             sprintf (operand[0], "%ld", address);
             print_label = 1;
           }
         else
           get_register_operand (insn_word & 0x0000001F, operand[0]);
       }
   }
 info->fprintf_func (info->stream, "   %s %s%c%s", insn->tm->name,
                     operand[0][0] ? operand[0] : "",
                     operand[1][0] ? ',' : ' ',
                     operand[1][0] ? operand[1] : "");
 /* Print destination of branch in relation to current symbol.  */
 if (print_label && info->symbols)
   {
     asymbol *sym = *info->symbols;

     if ((insn->tm->opcode_modifier == PCRel) && (insn_word & PCRel))
       {
         address = (_pc + 1 + (short) address) - ((sym->section->vma + sym->value) / 4);
         /* Check for delayed instruction, if so adjust destination.  */
         if (insn_word & 0x00200000)
           address += 2;
       }
     else
       {
         address -= ((sym->section->vma + sym->value) / 4);
       }
     if (address == 0)
       info->fprintf_func (info->stream, " <%s>", sym->name);
     else
       info->fprintf_func (info->stream, " <%s %c %lu>", sym->name,
                           ((short) address < 0) ? '-' : '+',
                           address);
   }
 return 1;
}

int
print_insn_tic30 (bfd_vma pc, disassemble_info *info)
{
 unsigned long insn_word;
 struct instruction insn = { 0, NULL, NULL };
 bfd_vma bufaddr = pc - info->buffer_vma;

 if (bufaddr + 3 >= info->buffer_length)
   return -1;

 /* Obtain the current instruction word from the buffer.  */
 insn_word = (((unsigned) *(info->buffer + bufaddr) << 24)
              | (*(info->buffer + bufaddr + 1) << 16)
              | (*(info->buffer + bufaddr + 2) << 8)
              | *(info->buffer + bufaddr + 3));
 _pc = pc / 4;
 /* Get the instruction referred to by the current instruction word
    and print it out based on its type.  */
 if (!get_tic30_instruction (insn_word, &insn))
   return -1;
 switch (GET_TYPE (insn_word))
   {
   case TWO_OPERAND_1:
   case TWO_OPERAND_2:
     if (!print_two_operand (info, insn_word, &insn))
       return -1;
     break;
   case THREE_OPERAND:
     if (!print_three_operand (info, insn_word, &insn))
       return -1;
     break;
   case PAR_STORE:
   case MUL_ADDS:
     if (!print_par_insn (info, insn_word, &insn))
       return -1;
     break;
   case BRANCHES:
     if (!print_branch (info, insn_word, &insn))
       return -1;
     break;
   }
 return 4;
}