/* Copyright (C) 2023 Aryadev Chavali

 * You may distribute and modify this code under the terms of the
 * GPLv2 license.  You should have received a copy of the GPLv2
 * license with this file.  If not, please write to:
 * aryadev@aryadevchavali.com.

 * Created: 2023-10-15
 * Author: Aryadev Chavali
 * Description: Instructions and opcodes
 */

#ifndef INST_H
#define INST_H

#include "./base.h"

typedef enum
{
  OP_NOOP = 0,

  // 0b0001
  OP_PUSH_BYTE  = 0b00000001,
  OP_PUSH_WORD  = 0b00000101,
  OP_PUSH_FLOAT = 0b00001001,
  // 0b0010
  OP_PUSH_BYTE_REGISTER  = 0b00000010,
  OP_PUSH_WORD_REGISTER  = 0b00000110,
  OP_PUSH_FLOAT_REGISTER = 0b00001010,
  // 0b0100
  OP_POP_BYTE  = 0b00000100,
  OP_POP_WORD  = 0b00001100,
  OP_POP_FLOAT = 0b00010100,
  // 0b1000
  OP_MOV_BYTE  = 0b00001000,
  OP_MOV_WORD  = 0b00011000,
  OP_MOV_FLOAT = 0b00101000,

  OP_HALT,
} opcode_t;

#define OPCODE_IS_PUSH(OPCODE)     (((OPCODE)&0b1) == 0b1)
#define OPCODE_IS_PUSH_REG(OPCODE) (((OPCODE)&0b10) == 0b10)
#define OPCODE_IS_POP(OPCODE)      (((OPCODE)&0b100) == 0b100)
#define OPCODE_IS_MOV(OPCODE)      (((OPCODE)&0b1000) == 0b1000)

typedef struct
{
  opcode_t opcode;
  data_t operand;
  byte reg; // At most 255 registers
} inst_t;

#define INST_BPUSH(BYTE) \
  ((inst_t){.opcode = OP_PUSH_BYTE, .operand = DBYTE(BYTE)})

#define INST_WPUSH(WORD) \
  ((inst_t){.opcode = OP_PUSH_WORD, .operand = DWORD(WORD)})

#define INST_FPUSH(FLOAT) \
  ((inst_t){.opcode = OP_PUSH_FLOAT, .operand = DFLOAT(FLOAT)})

#define INST_BMOV(BYTE, REG) \
  ((inst_t){.opcode = OP_MOV_BYTE, .operand = DBYTE(BYTE), .reg = (REG)})

#define INST_WMOV(WORD, REG) \
  ((inst_t){.opcode = OP_MOV_WORD, .operand = DWORD(WORD), .reg = (REG)})

#define INST_FMOV(FLOAT, REG) \
  ((inst_t){.opcode = OP_MOV_FLOAT, .operand = DFLOAT(FLOAT), .reg = (REG)})

#define INST_BPOP(BYTE) \
  ((inst_t){.opcode = OP_POP_BYTE, .operand = DBYTE(BYTE)})

#define INST_WPOP(WORD) \
  ((inst_t){.opcode = OP_POP_WORD, .operand = DWORD(WORD)})

#define INST_FPOP(FLOAT) \
  ((inst_t){.opcode = OP_POP_FLOAT, .operand = DFLOAT(FLOAT)})

#define INST_BPUSH_REG(REG) \
  ((inst_t){.opcode = OP_PUSH_BYTE_REGISTER, .reg = (REG)})

#define INST_WPUSH_REG(REG) \
  ((inst_t){.opcode = OP_PUSH_WORD_REGISTER, .reg = (REG)})

#define INST_FPUSH_REG(REG) \
  ((inst_t){.opcode = OP_PUSH_FLOAT_REGISTER, .reg = (REG)})

#endif