
#include "fr.hpp"

// distinct sizes :
enum {
    S_0,
    S_4,        // 4 bits
    S_5,        // 5 bits
    S_8,        // 8 bits
    S_11,       // 11 bits
    S_12,       // 12 bits
    S_16        // 16 bits
};

// bits numbers for sizes :
const int bits[] = {
    0,
    4,
    5,
    8,
    11,
    12,
    16
};

// masks for sizes :
const int masks[] = {
    0x0000,
    0x000F,
    0x001F,
    0x00FF,
    0x07FF,
    0x0FFF,
    0xFFFF
};

const char dtypes[] = {
    0,
    dt_byte,
    dt_byte,
    dt_byte,
    dt_word,
    dt_word,
    dt_word
};

// distinct operands :
enum {
    O_null,         // null opcode
    O_gr,           // general register                         Ri
    O_gri,          // general register indirect                @Ri
    O_grip,         // general register indirect post-increment @Ri+
    O_r13_gr_i,     // indirect r13 + general register          @(R13, Ri)
    O_r14_imm8_i,   // indirect r14 + 8 bits immediate value    @(R14, imm)
    O_r15_imm4_i,   // indirect r15 + 4 bits immediate value    @(R15, imm)
    O_r15ip,        // indirect r15 post-increment              @R15+
    O_r15im,        // indirect r15 pre-decrement               @-R15
    O_r13,          // register r13                             R13
    O_r13ip,        // indirect r13 post-increment              @R13+
    O_dr,           // dedicated register                       Rs
    O_ps,           // program status register (PS)             PS
    O_imm,          // immediate value                          #i
    O_diri,         // indirect direct value                    @i
    O_rel,          // relative value                           label5
    O_reglist       // register list                            (R0, R1, R2, ...)
};

static int invert_word(int word) {
    int new_word = 0;

    new_word |= (word & 0x000F) >> 0;
    new_word <<= 4;
    new_word |= (word & 0x00F0) >> 4;
    new_word <<= 4;
    new_word |= (word & 0x0F00) >> 8;
    new_word <<= 4;
    new_word |= (word & 0xF000) >> 12;

    return new_word;
}

// structure of an opcode :
struct opcode_t {
    int insn;
    int opcode;
    int opcode_size;

    int op1;
    int op1_size;
    int op2;
    int op2_size;

#define I_SWAPOPS          0x00000100      // swap operands
#define I_DSHOT            0x00000200      // delay shot
#define I_ADDR_R           OP_ADDR_R
#define I_ADDR_W           OP_ADDR_W
#define I_IMM_2            0x00001000      // imm = imm * 2
#define I_IMM_4            0x00002000      // imm = imm * 4
    int flags;

    inline bool swap_ops(void) const { return flags & I_SWAPOPS; }
    inline bool delay_shot(void) const { return flags & I_DSHOT; }
    inline bool implied(void) const { return op1 == O_null && op2 == O_null; }

    inline int size(void) const {
        int n = bits[opcode_size];
        if ( op1 != O_null )   n += bits[op1_size];
        if ( op2 != O_null )   n += bits[op2_size];
        return n;
    }

    static void check(void);
    static const struct opcode_t * find(int *_data);
};

// FR opcodes :
static const struct opcode_t opcodes[] = {
    { fr_add,       0xA6,       S_8,    O_gr,           S_4,    O_gr,       S_4,        0         },
    { fr_add,       0xA4,       S_8,    O_imm,          S_4,    O_gr,       S_4,        0         },
    { fr_add2,      0xA5,       S_8,    O_imm,          S_4,    O_gr,       S_4,        0         },
    { fr_addc,      0xA7,       S_8,    O_gr,           S_4,    O_gr,       S_4,        0         },
    { fr_addn,      0xA2,       S_8,    O_gr,           S_4,    O_gr,       S_4,        0         },
    { fr_addn,      0xA0,       S_8,    O_imm,          S_4,    O_gr,       S_4,        0         },
    { fr_addn2,     0xA1,       S_8,    O_imm,          S_4,    O_gr,       S_4,        0         },
    { fr_sub,       0xAC,       S_8,    O_gr,           S_4,    O_gr,       S_4,        0         },
    { fr_subc,      0xAD,       S_8,    O_gr,           S_4,    O_gr,       S_4,        0         },
    { fr_subn,      0xAE,       S_8,    O_gr,           S_4,    O_gr,       S_4,        0         },
    { fr_cmp,       0xAA,       S_8,    O_gr,           S_4,    O_gr,       S_4,        0         },
    { fr_cmp,       0xA8,       S_8,    O_imm,          S_4,    O_gr,       S_4,        0         },
    { fr_cmp2,      0xA9,       S_8,    O_imm,          S_4,    O_gr,       S_4,        0         },
    { fr_and,       0x82,       S_8,    O_gr,           S_4,    O_gr,       S_4,        0         },
    { fr_and,       0x84,       S_8,    O_gr,           S_4,    O_gri,      S_4,        0         },
    { fr_andh,      0x85,       S_8,    O_gr,           S_4,    O_gri,      S_4,        0         },
    { fr_andb,      0x86,       S_8,    O_gr,           S_4,    O_gri,      S_4,        0         },
    { fr_or,        0x92,       S_8,    O_gr,           S_4,    O_gr,       S_4,        0         },
    { fr_or,        0x94,       S_8,    O_gr,           S_4,    O_gri,      S_4,        0         },
    { fr_orh,       0x95,       S_8,    O_gr,           S_4,    O_gri,      S_4,        0         },
    { fr_orb,       0x96,       S_8,    O_gr,           S_4,    O_gri,      S_4,        0         },
    { fr_eor,       0x9A,       S_8,    O_gr,           S_4,    O_gr,       S_4,        0         },
    { fr_eor,       0x9C,       S_8,    O_gr,           S_4,    O_gri,      S_4,        0         },
    { fr_eorh,      0x9D,       S_8,    O_gr,           S_4,    O_gri,      S_4,        0         },
    { fr_eorb,      0x9E,       S_8,    O_gr,           S_4,    O_gri,      S_4,        0         },
    { fr_bandl,     0x80,       S_8,    O_imm,          S_4,    O_gri,      S_4,        0         },
    { fr_bandh,     0x81,       S_8,    O_imm,          S_4,    O_gri,      S_4,        0         },
    { fr_borl,      0x90,       S_8,    O_imm,          S_4,    O_gri,      S_4,        0         },
    { fr_borh,      0x91,       S_8,    O_imm,          S_4,    O_gri,      S_4,        0         },
    { fr_beorl,     0x98,       S_8,    O_imm,          S_4,    O_gri,      S_4,        0         },
    { fr_beorh,     0x99,       S_8,    O_imm,          S_4,    O_gri,      S_4,        0         },
    { fr_btstl,     0x88,       S_8,    O_imm,          S_4,    O_gri,      S_4,        0         },
    { fr_btsth,     0x89,       S_8,    O_imm,          S_4,    O_gri,      S_4,        0         },
    { fr_mul,       0xAF,       S_8,    O_gr,           S_4,    O_gr,       S_4,        0         },
    { fr_mulu,      0xAB,       S_8,    O_gr,           S_4,    O_gr,       S_4,        0         },
    { fr_mulh,      0xBF,       S_8,    O_gr,           S_4,    O_gr,       S_4,        0         },
    { fr_muluh,     0xBB,       S_8,    O_gr,           S_4,    O_gr,       S_4,        0         },
    { fr_div0s,     0x974,      S_12,   O_gr,           S_4,    O_null,     0,          0         },
    { fr_div0u,     0x975,      S_12,   O_gr,           S_4,    O_null,     0,          0         },
    { fr_div1,      0x976,      S_12,   O_gr,           S_4,    O_null,     0,          0         },
    { fr_div2,      0x977,      S_12,   O_gr,           S_4,    O_null,     0,          0         },
    { fr_div3,      0x9F60,     S_16,   O_null,         0,      O_null,     0,          0         },
    { fr_div4s,     0x9F70,     S_16,   O_null,         0,      O_null,     0,          0         },
    { fr_lsl,       0xB6,       S_8,    O_gr,           S_4,    O_gr,       S_4,        0         },
    { fr_lsl,       0xB4,       S_8,    O_imm,          S_4,    O_gr,       S_4,        0         },
    { fr_lsl2,      0xB5,       S_8,    O_imm,          S_4,    O_gr,       S_4,        0         },
    { fr_lsr,       0xB2,       S_8,    O_gr,           S_4,    O_gr,       S_4,        0         },
    { fr_lsr,       0xB0,       S_8,    O_imm,          S_4,    O_gr,       S_4,        0         },
    { fr_lsr2,      0xB1,       S_8,    O_imm,          S_4,    O_gr,       S_4,        0         },
    { fr_asr,       0xBA,       S_8,    O_gr,           S_4,    O_gr,       S_4,        0         },
    { fr_asr,       0xB8,       S_8,    O_imm,          S_4,    O_gr,       S_4,        0         },
    { fr_asr2,      0xB9,       S_8,    O_imm,          S_4,    O_gr,       S_4,        0         },
    // fr_ldi_32 not here (considered as special)
    // fr_ldi_20 not here (considered as special)
    { fr_ldi_8,     0x0C,       S_4,    O_imm,          S_8,    O_gr,       S_4,        0         },
    { fr_ld,        0x04,       S_8,    O_gri,          S_4,    O_gr,       S_4,        0         },
    { fr_ld,        0x00,       S_8,    O_r13_gr_i,     S_4,    O_gr,       S_4,        0         },
    { fr_ld,        0x02,       S_4,    O_r14_imm8_i,   S_8,    O_gr,       S_4,        I_IMM_4   },
    { fr_ld,        0x03,       S_8,    O_r15_imm4_i,   S_4,    O_gr,       S_4,        I_IMM_4   },
    { fr_ld,        0x70,       S_12,   O_r15ip,        S_0,    O_gr,       S_4,        0         },
    { fr_ld,        0x78,       S_12,   O_r15ip,        S_0,    O_dr,       S_4,        0         },
    { fr_ld,        0x790,      S_16,   O_r15ip,        S_0,    O_ps,       S_0,        0         },
    { fr_lduh,      0x05,       S_8,    O_gri,          S_4,    O_gr,       S_4,        0         },
    { fr_lduh,      0x01,       S_8,    O_r13_gr_i,     S_4,    O_gr,       S_4,        0         },
    { fr_lduh,      0x04,       S_4,    O_r14_imm8_i,   S_8,    O_gr,       S_4,        I_IMM_2   },
    { fr_ldub,      0x06,       S_8,    O_gri,          S_4,    O_gr,       S_4,        0         },
    { fr_ldub,      0x02,       S_8,    O_r13_gr_i,     S_4,    O_gr,       S_4,        0         },
    { fr_ldub,      0x06,       S_4,    O_r14_imm8_i,   S_8,    O_gr,       S_4,        0         },
    { fr_st,        0x14,       S_8,    O_gri,          S_4,    O_gr,       S_4,        I_SWAPOPS },
    { fr_st,        0x10,       S_8,    O_r13_gr_i,     S_4,    O_gr,       S_4,        I_SWAPOPS },
    { fr_st,        0x03,       S_4,    O_r14_imm8_i,   S_8,    O_gr,       S_4,        I_SWAPOPS|I_IMM_4 },
    { fr_st,        0x13,       S_8,    O_r15_imm4_i,   S_4,    O_gr,       S_4,        I_SWAPOPS|I_IMM_4 },
    { fr_st,        0x170,      S_12,   O_gr,           S_4,    O_r15im,    S_0,        0         },
    { fr_st,        0x178,      S_12,   O_dr,           S_4,    O_r15im,    S_0,        0         },
    { fr_st,        0x1790,     S_16,   O_ps,           S_0,    O_r15im,    S_0,        0         },
    { fr_sth,       0x15,       S_8,    O_gri,          S_4,    O_gr,       S_4,        I_SWAPOPS },
    { fr_sth,       0x11,       S_8,    O_r13_gr_i,     S_4,    O_gr,       S_4,        I_SWAPOPS },
    { fr_sth,       0x05,       S_4,    O_r14_imm8_i,   S_8,    O_gr,       S_4,        I_SWAPOPS|I_IMM_2 },
    { fr_stb,       0x16,       S_8,    O_gri,          S_4,    O_gr,       S_4,        I_SWAPOPS },
    { fr_stb,       0x12,       S_8,    O_r13_gr_i,     S_4,    O_gr,       S_4,        I_SWAPOPS },
    { fr_stb,       0x07,       S_4,    O_r14_imm8_i,   S_8,    O_gr,       S_4,        I_SWAPOPS },
    { fr_mov,       0x8B,       S_8,    O_gr,           S_4,    O_gr,       S_4,        0         },
    { fr_mov,       0xB7,       S_8,    O_dr,           S_4,    O_gr,       S_4,        0         },
    { fr_mov,       0x171,      S_12,   O_ps,           S_0,    O_gr,       S_4,        0         },
    { fr_mov,       0xB3,       S_8,    O_dr,           S_4,    O_gr,       S_4,        I_SWAPOPS },
    { fr_mov,       0x71,       S_12,   O_gr,           S_4,    O_ps,       S_0,        0         },
    { fr_jmp,       0x970,      S_12,   O_gri,          S_4,    O_null,     0,          0         },
    { fr_call,      0x971,      S_12,   O_gri,          S_4,    O_null,     0,          0         },
    { fr_ret,       0x9720,     S_16,   O_null,         0,      O_null,     0,          0         },
    { fr_int,       0x1F,       S_8,    O_imm,          S_8,    O_null,     0,          0         },
    { fr_inte,      0x9F30,     S_16,   O_null,         0,      O_null,     0,          0         },
    { fr_reti,      0x9730,     S_16,   O_null,         0,      O_null,     0,          0         },
    { fr_bra,       0xE0,       S_8,    O_rel,          S_8,    O_null,     0,          0         },
    { fr_bno,       0xE1,       S_8,    O_rel,          S_8,    O_null,     0,          0         },
    { fr_beq,       0xE2,       S_8,    O_rel,          S_8,    O_null,     0,          0         },
    { fr_bne,       0xE3,       S_8,    O_rel,          S_8,    O_null,     0,          0         },
    { fr_bc,        0xE4,       S_8,    O_rel,          S_8,    O_null,     0,          0         },
    { fr_bnc,       0xE5,       S_8,    O_rel,          S_8,    O_null,     0,          0         },
    { fr_bn,        0xE6,       S_8,    O_rel,          S_8,    O_null,     0,          0         },
    { fr_bp,        0xE7,       S_8,    O_rel,          S_8,    O_null,     0,          0         },
    { fr_bv,        0xE8,       S_8,    O_rel,          S_8,    O_null,     0,          0         },
    { fr_bnv,       0xE9,       S_8,    O_rel,          S_8,    O_null,     0,          0         },
    { fr_blt,       0xEA,       S_8,    O_rel,          S_8,    O_null,     0,          0         },
    { fr_bge,       0xEB,       S_8,    O_rel,          S_8,    O_null,     0,          0         },
    { fr_ble,       0xEC,       S_8,    O_rel,          S_8,    O_null,     0,          0         },
    { fr_bgt,       0xED,       S_8,    O_rel,          S_8,    O_null,     0,          0         },
    { fr_bls,       0xEE,       S_8,    O_rel,          S_8,    O_null,     0,          0         },
    { fr_bhi,       0xEF,       S_8,    O_rel,          S_8,    O_null,     0,          0         },
    { fr_jmp,       0x9F0,      S_12,   O_gri,          S_4,    O_null,     0,          I_DSHOT   },
    { fr_call,      0x9F1,      S_12,   O_gri,          S_4,    O_null,     0,          I_DSHOT   },
    { fr_ret,       0x9F20,     S_16,   O_null,         0,      O_null,     0,          I_DSHOT   },
    { fr_bra,       0xF0,       S_8,    O_rel,          S_8,    O_null,     0,          I_DSHOT   },
    { fr_bno,       0xF1,       S_8,    O_rel,          S_8,    O_null,     0,          I_DSHOT   },
    { fr_beq,       0xF2,       S_8,    O_rel,          S_8,    O_null,     0,          I_DSHOT   },
    { fr_bne,       0xF3,       S_8,    O_rel,          S_8,    O_null,     0,          I_DSHOT   },
    { fr_bc,        0xF4,       S_8,    O_rel,          S_8,    O_null,     0,          I_DSHOT   },
    { fr_bnc,       0xF5,       S_8,    O_rel,          S_8,    O_null,     0,          I_DSHOT   },
    { fr_bn,        0xF6,       S_8,    O_rel,          S_8,    O_null,     0,          I_DSHOT   },
    { fr_bp,        0xF7,       S_8,    O_rel,          S_8,    O_null,     0,          I_DSHOT   },
    { fr_bv,        0xF8,       S_8,    O_rel,          S_8,    O_null,     0,          I_DSHOT   },
    { fr_bnv,       0xF9,       S_8,    O_rel,          S_8,    O_null,     0,          I_DSHOT   },
    { fr_blt,       0xFA,       S_8,    O_rel,          S_8,    O_null,     0,          I_DSHOT   },
    { fr_bge,       0xFB,       S_8,    O_rel,          S_8,    O_null,     0,          I_DSHOT   },
    { fr_ble,       0xFC,       S_8,    O_rel,          S_8,    O_null,     0,          I_DSHOT   },
    { fr_bgt,       0xFD,       S_8,    O_rel,          S_8,    O_null,     0,          I_DSHOT   },
    { fr_bls,       0xFE,       S_8,    O_rel,          S_8,    O_null,     0,          I_DSHOT   },
    { fr_bhi,       0xFF,       S_8,    O_rel,          S_8,    O_null,     0,          I_DSHOT   },
    { fr_dmov,      0x08,       S_8,    O_diri,         S_8,    O_r13,      S_0,        I_ADDR_R  },
    { fr_dmov,      0x18,       S_8,    O_r13,          S_0,    O_diri,     S_8,        I_ADDR_W  },
    { fr_dmov,      0x0C,       S_8,    O_diri,         S_8,    O_r13ip,    S_0,        I_ADDR_R  },
    { fr_dmov,      0x1C,       S_8,    O_r13ip,        S_0,    O_diri,     S_8,        I_ADDR_W  },
    { fr_dmov,      0x0B,       S_8,    O_diri,         S_8,    O_r15im,    S_0,        I_ADDR_R  },
    { fr_dmov,      0x1B,       S_8,    O_r15ip,        S_0,    O_diri,     S_8,        I_ADDR_W  },
    { fr_dmovh,     0x09,       S_8,    O_diri,         S_8,    O_r13,      S_0,        I_ADDR_R  },
    { fr_dmovh,     0x19,       S_8,    O_r13,          S_0,    O_diri,     S_8,        I_ADDR_W  },
    { fr_dmovh,     0x0D,       S_8,    O_diri,         S_8,    O_r13ip,    S_0,        I_ADDR_R  },
    { fr_dmovh,     0x1D,       S_8,    O_r13ip,        S_0,    O_diri,     S_8,        I_ADDR_W  },
    { fr_dmovb,     0x0A,       S_8,    O_diri,         S_8,    O_r13,      S_0,        I_ADDR_R  },
    { fr_dmovb,     0x1A,       S_8,    O_r13,          S_0,    O_diri,     S_8,        I_ADDR_W  },
    { fr_dmovb,     0x0E,       S_8,    O_diri,         S_8,    O_r13ip,    S_0,        I_ADDR_R  },
    { fr_dmovb,     0x1E,       S_8,    O_r13ip,        S_0,    O_diri,     S_8,        I_ADDR_W  },
    { fr_ldres,     0xBC,       S_8,    O_imm,          S_4,    O_grip,     S_4,        I_SWAPOPS },
    { fr_stres,     0xBD,       S_8,    O_imm,          S_4,    O_grip,     S_4,        0         },
    // fr_copop not here (considered as special)
    // fr_copld not here (considered as special)
    // fr_copst not here (considered as special)
    // fr_copsv not here (considered as special)
    { fr_nop,       0x9FA0,     S_16,   O_null,         0,      O_null,     0,          0         },
    { fr_andccr,    0x83,       S_8,    O_imm,          S_8,    O_null,     0,          0         },
    { fr_orccr,     0x93,       S_8,    O_imm,          S_8,    O_null,     0,          0         },
    { fr_stilm,     0x87,       S_8,    O_imm,          S_8,    O_null,     0,          0         },
    { fr_addsp,     0xA3,       S_8,    O_imm,          S_8,    O_null,     0,          0         },
    { fr_extsb,     0x978,      S_12,   O_gr,           S_4,    O_null,     0,          0         },
    { fr_extub,     0x979,      S_12,   O_gr,           S_4,    O_null,     0,          0         },
    { fr_extsh,     0x97A,      S_12,   O_gr,           S_4,    O_null,     0,          0         },
    { fr_extuh,     0x97B,      S_12,   O_gr,           S_4,    O_null,     0,          0         },
    { fr_ldm0,      0x8C,       S_8,    O_reglist,      S_8,    O_null,     0,          0         },
    { fr_ldm1,      0x8D,       S_8,    O_reglist,      S_8,    O_null,     0,          0         },
    { fr_stm0,      0x8E,       S_8,    O_reglist,      S_8,    O_null,     0,          0         },
    { fr_stm1,      0x8F,       S_8,    O_reglist,      S_8,    O_null,     0,          0         },
    { fr_enter,     0x0F,       S_8,    O_imm,          S_8,    O_null,     0,          I_IMM_4   },
    { fr_leave,     0x9F90,     S_16,   O_null,         0,      O_null,     0,          0         },
    { fr_xchb,      0x8A,       S_8,    O_gri,          S_4,    O_gr,       S_4,        0         }
};

void opcode_t::check(void) {
    for (int i = 0; i < qnumber(opcodes); i++) {
        int n = opcodes[i].size();
#if 0
        if ( n != 16 && n != 32 )
            msg("instruction n%d (%d) : size %d\n", i, opcodes[i].insn, n);
#endif
        QASSERT(10001, n == 16 || n == 32);
    }
}

const struct opcode_t * opcode_t::find(int *_data) {
    QASSERT(10002, _data != NULL);

    int data = (*_data << 8) | get_byte(cmd.ip + cmd.size);
    for (int i = 0; i < qnumber(opcodes); i++) {
        int mask;
        int shift;
        switch ( opcodes[i].opcode_size ) {
            case S_4:       mask = 0xF000; shift = 12; break;
            case S_5:       mask = 0xF100; shift = 11; break;
            case S_8:       mask = 0xFF00; shift = 8;  break;
            case S_12:      mask = 0xFFF0; shift = 4;  break;
            case S_16:      mask = 0xFFFF; shift = 0;  break;
            default:        INTERR(10012);
        }
        if ( ((data & mask) >> shift) != opcodes[i].opcode )
            continue;

        cmd.size++;
        *_data = invert_word(data);

        return &opcodes[i];
    }
    return NULL;
}

// get general register.
static int get_gr(const int num) {
    QASSERT(10003, num >= 0 && num <= 15);
    return num;
}

// get coprocessor register.
static int get_cr(const int num) {
    QASSERT(10004, num >= 0 && num <= 15);
    return num + 16;
}

// get dedicated register.
static int get_dr(const int num) {
    static int drs[] = {
        rTBR,
        rRP,
        rSSP,
        rUSP,
        rMDH,
        rMDL,
        rReserved6,
        rReserved7,
        rReserved8,
        rReserved9,
        rReserved10,
        rReserved11,
        rReserved12,
        rReserved13,
        rReserved14,
        rReserved15
    };
    QASSERT(10005, num >= 0 && num <= 15);
    return drs[num];
}

// fill an operand as a register.
static void set_reg(op_t &op, int reg, char d_typ) {
    op.type = o_reg;
    op.reg = (uint16)reg;
    op.dtyp = d_typ;
}

// fill an operand as an immediate value.
static void set_imm(op_t &op, int imm, char d_typ) {
    op.type = o_imm;
    switch ( d_typ ) {
        case dt_byte:   op.value = (char) imm; break;
        case dt_word:   op.value = (short) imm; break;
        case dt_dword:  op.value = imm; break;
        default:        INTERR(10013);
    }
    op.dtyp = d_typ;
}

// fill an operand as a phrase.
static void set_phrase(op_t &op, int type, int val, char d_typ) {
    switch ( type ) {
        case fIGR:       // indirect general register
        case fIGRP:      // indirect general register with post-increment
        case fIGRM:      // indirect general register with pre-decrement
        case fR13RI:     // indirect displacement between R13 and a general register
            op.reg = (uint16)val;
            break;

        case fIRA:       // indirect relative address
            op.addr = val;
            break;

        default:
            INTERR(10014);
    }
    op.type = o_phrase;
    op.specflag2 = (char)type;
    op.dtyp = d_typ;
}

// fill an operand as a relative address.
static void set_rel(op_t &op, int addr, char d_typ) {
    op.type = o_near;
    int raddr;
    switch ( d_typ ) {    /* ugly but functional */
        case dt_byte:
            raddr = ((signed char) addr);
            break;

        case dt_word:
            raddr = ((signed short) addr);
            break;

        default:
            INTERR(10015);
    }
    op.addr = cmd.ip + 2 + (raddr * 2);
#if defined(__DEBUG__)
    msg("0x%a = 0x%a + 2 + ((signed) 0x%X) * 2)\n", op.addr, cmd.ip, addr);
#endif /* __DEBUG__ */
    op.dtyp = dt_code;
}

// fill an operand as a reglist
static void set_reglist(op_t &op, int list) {
    op.type = o_reglist;
    op.value = list;
    op.dtyp = dt_byte;  // list is coded in a byte
}

static void set_displ(op_t &op, int reg, int imm, int flag, int local_flag) {
    op.type = o_displ;
    if ( reg != -1) op.reg = (uint16)get_gr(reg );
    if ( imm != -1 ) {
        int mul = 1;
        if ( local_flag & I_IMM_2 )         mul = 2;
        if ( local_flag & I_IMM_4 )         mul = 4;
        op.value = ((unsigned) imm) * mul;
    }
    op.dtyp = dt_byte;
    op.specflag1 |= flag;
}

// swap 2 opcodes (o1 <=> o2).
static void swap_ops(op_t &o1, op_t &o2) {
    QASSERT(10006, o1.type != o_void && o2.type != o_void);
    op_t tmp = o1;
    o1 = o2;
    o2 = tmp;
}

static void adjust_data(int size, int *data) {
    QASSERT(10007, data != NULL);
    int new_data = *data >> bits[size];
    *data = new_data;
}

/*
static void prepare_data(int size, int *data) {
    QASSERT(10008, data != NULL);
    int new_data = 0;
    switch ( size ) {
        case S_0:
        case S_4:
            new_data = *data;
            break;

        case S_5:
        case S_8:
            new_data |= (*data & 0x00F0) >> 4;
            new_data |= (*data & 0x000F) << 4;
            break;

        case S_11:
        case S_12:
            new_data |= (*data & 0x0F00) >> 8;
            new_data |= (*data & 0x00F0) >> 0;
            new_data |= (*data & 0x000F) << 8;
            break;

        case S_16:
            new_data |= (*data & 0xF000) >> 12;
            new_data |= (*data & 0x0F00) >> 4;
            new_data |= (*data & 0x00F0) << 4;
            new_data |= (*data & 0x000F) << 12;
            break;
    }
    *data = new_data;
}*/

#define SWAP_IF_BYTE(data)                  \
    do {                                    \
        if ( operand_size == S_8 ) {          \
            int h = (data & 0x0F) << 4;     \
            int l = (data & 0xF0) >> 4;     \
            data = h | l;                   \
        }                                   \
    }                                       \
    while ( 0 )

//
// defines some shortcuts.
//

#define __set_gr(op, reg)               set_reg(op, reg, dt_byte)
#define set_gr(op, reg)                 __set_gr(op, get_gr(reg))
#define __set_dr(op, reg)               set_reg(op, reg, dt_word)
#define set_dr(op, reg)                 __set_dr(op, get_dr(reg))
#define __set_cr(op, reg)               set_reg(op, reg, dt_word)
#define set_cr(op, reg)                 __set_cr(op, get_cr(reg))

#define set_gri(op, reg)                set_phrase(op, fIGR, get_gr(reg), dt_byte)
#define set_grip(op, reg)               set_phrase(op, fIGRP, get_gr(reg), dt_byte)
#define set_grim(op, reg)               set_phrase(op, fIGRM, get_gr(reg), dt_byte)
#define set_diri(op, addr)              set_phrase(op, fIRA, addr, dt_word)
#define set_r13_gr_i(op, reg)           set_phrase(op, fR13RI, get_gr(reg), dt_byte)
#define fill_op1(data, opc)             fill_op(data, cmd.Op1, opc->op1, opc->op1_size, opc->flags)
#define fill_op2(data, opc)             fill_op(data, cmd.Op2, opc->op2, opc->op2_size, opc->flags)
#define set_displ_gr(op, gr, f1)        set_displ(op, gr, -1, f1, 0)
#define set_displ_imm(op, imm, f1, f2)  set_displ(op, -1, imm, f1, f2)

static void fill_op(int data, op_t &op, int operand, int operand_size, int flags) {
    data &= masks[operand_size];
    //prepare_data(operand_size, &data);
    switch ( operand ) {
        case O_gr:           // general register                         Ri
            QASSERT(10009, operand_size == S_4);
            set_gr(op, data);
            break;

        case O_gri:          // general register indirect                @Ri
            QASSERT(10010, operand_size == S_4);
            set_gri(op, data);
            break;

        case O_grip:          // general register indirect                @Ri
            QASSERT(10011, operand_size == S_4);
            set_grip(op, data);
            break;

        case O_r13_gr_i:     // indirect r13 + general register          @(R13, Ri)
            set_r13_gr_i(op, data);
            break;

        case O_r14_imm8_i:   // indirect r14 + 8 bits immediate value    @(R14, imm)
            SWAP_IF_BYTE(data);
            set_displ_imm(op, data, OP_DISPL_IMM_R14, flags);
            break;

        case O_r15_imm4_i:   // indirect r15 + 4 bits immediate value    @(R15, imm)
            SWAP_IF_BYTE(data);
            set_displ_imm(op, data, OP_DISPL_IMM_R15, flags);
            break;

        case O_r15ip:        // indirect r15 post-increment              @R15+
            set_grip(op, rR15);
            break;

        case O_r15im:        // indirect r15 pre-decrement               @-R15
            set_grim(op, rR15);
            break;

        case O_r13:          // register r13                             R13
            __set_gr(op, rR13);
            break;

        case O_r13ip:        // indirect r13 post-increment              @R13+
            set_grip(op, rR13);
            break;

        case O_dr:           // dedicated register                       Rs
            set_dr(op, data);
            break;

        case O_ps:           // program status register (PS)             PS
            __set_dr(op, rPS);
            break;

        case O_imm:          // immediate value                          #i
            {
                SWAP_IF_BYTE(data);
                if ( cmd.itype == fr_enter )   data *= 4;
                if ( cmd.itype == fr_addsp)   data = ((signed) data ) * 4;
                set_imm(op, data, dtypes[operand_size]);
             }
             break;

        case O_diri:         // indirect direct value                    @i
            {
                SWAP_IF_BYTE(data);
                if ( cmd.itype == fr_dmov )   data *= 4;
                if ( cmd.itype == fr_dmovh )  data *= 2;
                set_diri(op, data);
            }
            op.specflag1 |= flags;
            break;

        case O_rel:          // relative value                           label5
            SWAP_IF_BYTE(data);
            set_rel(op, data, dtypes[operand_size]);
            break;

        case O_reglist:      // register list                            (R0, R1, R2, ...)
            SWAP_IF_BYTE(data);
            set_reglist(op, data);
            break;

        case O_null:         // null opcode
            INTERR(10016);
    }
}

// analyze a "common" instruction (those which are listed in the opcodes[] array).
static bool ana_common(int data) {
    const struct opcode_t *op = opcode_t::find(&data);
    if ( op == NULL )
        return false;

    // fill instruction type
    cmd.itype = (uint16)op->insn;

    // if instruction is implied, our job is finished!
    if ( op->implied() )
        goto ana_finished;

    adjust_data(op->opcode_size, &data);

    // fill operand 1
    if ( op->op1 != O_null ) {
        fill_op1(data, op);
        adjust_data(op->op1_size, &data);
    }

    // fill operand 2
    if ( op->op2 != O_null ) {
        fill_op2(data, op);
        adjust_data(op->op2_size, &data);
    }

    // swap opcodes if needed
    if ( op->swap_ops() )
        swap_ops(cmd.Op1, cmd.Op2);

ana_finished:
    cmd.auxpref = 0;

    // is insn delay shot ?
    if ( op->delay_shot() )
        cmd.auxpref |= INSN_DELAY_SHOT;

    return true;
}

// analyze a "special" instruction (those which are NOT listed in the opcodes[] array).
static bool ana_special(int data) {
    // detect ldi:20 instructions
    if ( data == 0x9B ) {
        cmd.itype = fr_ldi_20;
        data = (data << 8) | ua_next_byte();
        set_gr(cmd.Op2, data & 0x000F);
        set_imm(cmd.Op1, ua_next_word() | ((data & 0x00F0) << 12), dt_dword);
        return true;
    }

    data = (data << 8) | get_byte(cmd.ea + cmd.size);

    // detect ldi:32 instructions
    if ( (data & 0xFFF0) == 0x9F80 ) {
        cmd.size++;
        cmd.itype = fr_ldi_32;
        set_gr(cmd.Op2, data & 0x000F);
        set_imm(cmd.Op1, ua_next_long(), dt_dword);
        return true;
    }

    // detect call [rel] instructions
    int tmp = (data & 0xF800) >> 11;
    if ( tmp == 0x1A || tmp == 0x1B ) {
        cmd.itype = fr_call;
        cmd.size++;
        // extend sign
        if ( data & 0x400 )
          data |= ~0x07FF;
        else
          data &= 0x07FF;
        set_rel(cmd.Op1, data, dt_word);
        if ( tmp == 0x1B )
            cmd.auxpref |= INSN_DELAY_SHOT;
        return true;
    }

    // detect copop/copld/copst/copsv instructions
    if ( ((data & 0xFF00) >> 8) == 0x9F ) {
        int word = get_word(cmd.ea + cmd.size + 1);
        cmd.itype = fr_null;
        switch ( (data & 0x00F0) >> 4 ) {

            // copop
            case 0xC:   cmd.itype = fr_copop;
                        set_cr(cmd.Op3, (word & 0x00F0) >> 4);
                        set_cr(cmd.Op4, word & 0x000F);
                        break;

            // copld
            case 0xD:   cmd.itype = fr_copld;
                        set_gr(cmd.Op3, (word & 0x00F0) >> 4);
                        set_cr(cmd.Op4, word & 0x000F);
                        break;

            // copst
            case 0xE:   cmd.itype = fr_copst;
                        set_cr(cmd.Op3, (word & 0x00F0) >> 4);
                        set_gr(cmd.Op4, word & 0x000F);
                        break;

            // copsv
            case 0xF:   cmd.itype = fr_copsv;
                        set_cr(cmd.Op3, (word & 0x00F0) >> 4);
                        set_gr(cmd.Op4, word & 0x000F);
                        break;
        }
        if ( cmd.itype != fr_null ) {
            set_imm(cmd.Op1, data & 0x000F, dt_byte);
            set_imm(cmd.Op2, (word & 0xFF00) >> 8, dt_byte);
            cmd.size += 3;
            return true;
        }
    }

    return false;
}

// analyze an instruction.
int idaapi ana(void) {
#if defined(__DEBUG__)
    opcode_t::check();
#endif /* __DEBUG__ */

    int byte = ua_next_byte();

    bool success = ana_special(byte);
    if ( !success )
        success = ana_common(byte);

    return (success ? cmd.size : 0);
}
