/*!
 \file C_extension.h
 \brief Implement C extensions part of the RISC-V
 \author Màrius Montón
 \date August 2018
*/
// SPDX-License-Identifier: GPL-3.0-or-later

#ifndef C_EXTENSION__H
#define C_EXTENSION__H

#include "systemc"
#include "extension_base.h"

namespace riscv_tlm {

    typedef enum {
        OP_C_ADDI4SPN,
        OP_C_FLD,
        OP_C_LW,
        OP_C_FLW,
        OP_C_FSD,
        OP_C_SW,
        OP_C_FSW,

        OP_C_NOP,
        OP_C_ADDI,
        OP_C_JAL,
        OP_C_LI,
        OP_C_ADDI16SP,
        OP_C_LUI,
        OP_C_SRLI,
        OP_C_SRAI,
        OP_C_ANDI,
        OP_C_SUB,
        OP_C_XOR,
        OP_C_OR,
        OP_C_AND,
        OP_C_J,
        OP_C_BEQZ,
        OP_C_BNEZ,

        OP_C_SLLI,
        OP_C_FLDSP,
        OP_C_LWSP,
        OP_C_FLWSP,
        OP_C_JR,
        OP_C_MV,
        OP_C_EBREAK,
        OP_C_JALR,
        OP_C_ADD,
        OP_C_FSDSP,
        OP_C_SWSP,
        OP_C_FSWSP,

        OP_C_ERROR
    } op_C_Codes;

    typedef enum {
        C_ADDI4SPN = 0b000,
        C_FLD = 0b001,
        C_LW = 0b010,
        C_FLW = 0b011,
        C_FSD = 0b101,
        C_SW = 0b110,
        C_FSW = 0b111,

        C_ADDI = 0b000,
        C_JAL = 0b001,
        C_LI = 0b010,
        C_ADDI16SP = 0b011,
        C_SRLI = 0b100,
        C_2_SRLI = 0b00,
        C_2_SRAI = 0b01,
        C_2_ANDI = 0b10,
        C_2_SUB = 0b11,
        C_3_SUB = 0b00,
        C_3_XOR = 0b01,
        C_3_OR = 0b10,
        C_3_AND = 0b11,
        C_J = 0b101,
        C_BEQZ = 0b110,
        C_BNEZ = 0b111,

        C_SLLI = 0b000,
        C_FLDSP = 0b001,
        C_LWSP = 0b010,
        C_FLWSP = 0b011,
        C_JR = 0b100,
        C_FDSP = 0b101,
        C_SWSP = 0b110,
        C_FWWSP = 0b111,
    } C_Codes;

/**
 * @brief Instruction decoding and fields access
 */
    class C_extension : public extension_base {
    public:

        /**
         * @brief Constructor, same as base clase
         */
        using extension_base::extension_base;

        /**
         * @brief Access to opcode field
         * @return return opcode field
         */
        inline std::int32_t opcode() const override {
            return static_cast<std::int32_t>(m_instr.range(1, 0));
        }

        inline std::int32_t get_rdp() const {
            return static_cast<std::int32_t>(m_instr.range(4, 2) + 8);
        }

        /**
         * @brief Access to rs1 field
         * @return rs1 field
         */
        inline std::int32_t get_rs1() const override {
            return static_cast<std::int32_t>(m_instr.range(11, 7));
        }

        inline void set_rs1(std::int32_t value) override {
            m_instr.range(11, 7) = value;
        }

        inline std::int32_t get_rs1p() const {
            return static_cast<std::int32_t>(m_instr.range(9, 7) + 8);
        }

        /**
         * @brief Access to rs2 field
         * @return rs2 field
         */
        inline std::int32_t get_rs2() const override {
            return static_cast<std::int32_t>(m_instr.range(6, 2));
        }

        inline void set_rs2(std::int32_t value) override {
            m_instr.range(6, 2) = value;
        }

        inline std::int32_t get_rs2p() const {
            return static_cast<std::int32_t>(m_instr.range(4, 2) + 8);
        }

        inline std::int32_t get_funct3() const override {
            return static_cast<std::int32_t>(m_instr.range(15, 13));
        }

        inline void set_funct3(std::int32_t value) override {
            m_instr.range(15, 13) = value;
        }

        /**
         * @brief Access to immediate field for I-type
         * @return immediate_I field
         */
        inline std::int32_t get_imm_I() const {
            std::int32_t aux = 0;

            aux = static_cast<std::int32_t>(m_instr.range(31, 20));

            /* sign extension (optimize) */
            if (m_instr[31] == 1) {
                aux |= (0b11111111111111111111) << 12;
            }

            return aux;
        }

        inline void set_imm_I(std::int32_t value) {
            m_instr.range(31, 20) = value;
        }

        /**
         * @brief Access to immediate field for S-type
         * @return immediate_S field
         */
        inline std::int32_t get_imm_S() const {
            std::int32_t aux = 0;

            aux = static_cast<std::int32_t>(m_instr.range(31, 25) << 5);
            aux |= static_cast<std::int32_t>(m_instr.range(11, 7));

            if (m_instr[31] == 1) {
                aux |= (0b11111111111111111111) << 12;
            }

            return aux;
        }

        inline void set_imm_S(std::int32_t value) {
            sc_dt::sc_uint<32> aux = value;

            m_instr.range(31, 25) = aux.range(11, 5);
            m_instr.range(11, 7) = aux.range(4, 0);
        }

        /**
         * @brief Access to immediate field for U-type
         * @return immediate_U field
         */
        inline std::int32_t get_imm_U() const {
            return static_cast<std::int32_t>(m_instr.range(31, 12));
        }

        inline void set_imm_U(std::int32_t value) {
            m_instr.range(31, 12) = (value << 12);
        }

        /**
         * @brief Access to immediate field for B-type
         * @return immediate_B field
         */
        inline std::int32_t get_imm_B() const {
            std::int32_t aux = 0;

            aux |= static_cast<std::int32_t>(m_instr[7] << 11);
            aux |= static_cast<std::int32_t>(m_instr.range(30, 25) << 5);
            aux |= static_cast<std::int32_t>(m_instr[31] << 12);
            aux |= static_cast<std::int32_t>(m_instr.range(11, 8) << 1);

            if (m_instr[31] == 1) {
                aux |= (0b11111111111111111111) << 12;
            }

            return aux;
        }

        inline void set_imm_B(std::int32_t value) {
            sc_dt::sc_uint<32> aux = value;

            m_instr[31] = aux[12];
            m_instr.range(30, 25) = aux.range(10, 5);
            m_instr.range(11, 7) = aux.range(4, 1);
            m_instr[6] = aux[11];
        }

        /**
         * @brief Access to immediate field for J-type
         * @return immediate_J field
         */
        inline std::int32_t get_imm_J() const {
            std::int32_t aux = 0;

            aux = static_cast<std::int32_t>(m_instr[12] << 11);
            aux |= static_cast<std::int32_t>(m_instr[11] << 4);
            aux |= static_cast<std::int32_t>(m_instr[10] << 9);
            aux |= static_cast<std::int32_t>(m_instr[9] << 8);
            aux |= static_cast<std::int32_t>(m_instr[8] << 10);
            aux |= static_cast<std::int32_t>(m_instr[7] << 6);
            aux |= static_cast<std::int32_t>(m_instr[6] << 7);
            aux |= static_cast<std::int32_t>(m_instr.range(5, 3) << 1);
            aux |= static_cast<std::int32_t>(m_instr[2] << 5);

            if (m_instr[12] == 1) {
                aux |= 0b11111111111111111111 << 12;
            }

            return aux;
        }

        inline void set_imm_J(std::int32_t value) {
            sc_dt::sc_uint<32> aux = (value << 20);

            m_instr[31] = aux[20];
            m_instr.range(30, 21) = aux.range(10, 1);
            m_instr[20] = aux[11];
            m_instr.range(19, 12) = aux.range(19, 12);
        }

        inline std::int32_t get_imm_L() const {
            std::int32_t aux = 0;

            aux = static_cast<std::int32_t>(m_instr.range(12, 10) << 3);
            aux |= static_cast<std::int32_t>(m_instr[6] << 2);
            aux |= static_cast<std::int32_t>(m_instr[5] << 6);

            return aux;
        }

        inline std::int32_t get_imm_LWSP() const {
            std::int32_t aux = 0;

            aux = static_cast<std::int32_t>(m_instr[12] << 5);
            aux |= static_cast<std::int32_t>(m_instr.range(6, 4) << 2);
            aux |= static_cast<std::int32_t>(m_instr.range(3, 2) << 6);

            return aux;
        }

        inline std::int32_t get_imm_ADDI() const {
            std::int32_t aux = 0;

            aux = static_cast<std::int32_t>(m_instr[12] << 5);
            aux |= static_cast<std::int32_t>(m_instr.range(6, 2));

            if (m_instr[12] == 1) {
                aux |= 0b11111111111111111111111111 << 6;
            }
            return aux;
        }

        inline std::int32_t get_imm_ADDI4SPN() const {
            std::int32_t aux = 0;

            aux = static_cast<std::int32_t>(m_instr.range(12, 11) << 4);
            aux |= static_cast<std::int32_t>(m_instr.range(10, 7) << 6);
            aux |= static_cast<std::int32_t>(m_instr[6] << 2);
            aux |= static_cast<std::int32_t>(m_instr[5] << 3);

            return aux;
        }

        inline std::int32_t get_imm_ADDI16SP() const {
            std::int32_t aux = 0;

            aux = static_cast<std::int32_t>(m_instr[12] << 9);
            aux |= static_cast<std::int32_t>(m_instr[6] << 4);
            aux |= static_cast<std::int32_t>(m_instr[5] << 6);
            aux |= static_cast<std::int32_t>(m_instr[4] << 8);
            aux |= static_cast<std::int32_t>(m_instr[3] << 7);
            aux |= static_cast<std::int32_t>(m_instr[2] << 5);

            if (m_instr[12] == 1) {
                aux |= 0b1111111111111111111111 << 10;
            }
            return aux;
        }

        inline std::int32_t get_imm_CSS() const {
            std::int32_t aux = 0;
            aux = static_cast<std::int32_t>(m_instr.range(12, 9) << 2);
            aux |= static_cast<std::int32_t>(m_instr.range(8, 7) << 6);

            return aux;
        }

        inline std::int32_t get_imm_CB() const {
            std::int32_t aux = 0;

            aux = static_cast<std::int32_t>(m_instr[12] << 8);
            aux |= static_cast<std::int32_t>(m_instr[11] << 4);
            aux |= static_cast<std::int32_t>(m_instr[10] << 3);
            aux |= static_cast<std::int32_t>(m_instr[6] << 7);
            aux |= static_cast<std::int32_t>(m_instr[5] << 6);
            aux |= static_cast<std::int32_t>(m_instr[4] << 2);
            aux |= static_cast<std::int32_t>(m_instr[3] << 1);
            aux |= static_cast<std::int32_t>(m_instr[2] << 5);

            if (m_instr[12] == 1) {
                aux |= 0b11111111111111111111111 << 9;
            }

            return aux;
        }

        inline std::int32_t get_imm_LUI() const {
            std::int32_t aux = 0;

            aux = static_cast<std::int32_t>(m_instr[12] << 17);
            aux |= static_cast<std::int32_t>(m_instr.range(6, 2) << 12);

            if (m_instr[12] == 1) {
                aux |= 0b111111111111111 << 17;
            }

            return aux;
        }

        inline std::int32_t get_csr() const {
            return get_imm_I();
        }

        /**
         * @brief Decodes opcode of instruction
         * @return opcode of instruction
         */
        op_C_Codes decode() const;

        bool Exec_C_JR();

        bool Exec_C_MV();

        bool Exec_C_LWSP();

        bool Exec_C_ADDI4SPN();

        bool Exec_C_SLLI();

        bool Exec_C_ADDI16SP();

        bool Exec_C_SWSP();

        bool Exec_C_BEQZ();

        bool Exec_C_BNEZ();

        bool Exec_C_LI();

        bool Exec_C_SRLI();

        bool Exec_C_SRAI();

        bool Exec_C_ANDI();

        bool Exec_C_ADD();

        bool Exec_C_SUB();

        bool Exec_C_XOR();

        bool Exec_C_OR();

        bool Exec_C_AND();

        bool Exec_C_ADDI() const;

        bool Exec_C_JALR();

        bool Exec_C_LW();

        bool Exec_C_SW();

        bool Exec_C_JAL(int m_rd);

        bool Exec_C_EBREAK();

        bool process_instruction(Instruction &inst, bool *breakpoint = nullptr);
    };
}

#endif