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#ifndef INSTR_H_
#define INSTR_H_
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include "input.h"
// We have to use bit masks to identify the instruction we are to perform.
// Instructions are stored in a uint32_t, and inputted from hex.
// The format of the bit masks vary between
//
// PPPPPP SSSSS TTTTT DDDDD IIIIIIIIIII
// 6 5 5 5 11
//
// PPPPPP SSSSS TTTTT IIIIIIIIIIIIIIII
// 6 5 5 16
//
// P = pattern_mask
// S = five bit register number
// T = five bit register number
// D = five bit register number
// I = immediate mask (size can very between instructions)
// Definitions for 32 bit instruction bits.
#define PATTERN_BITS 0xFC000000 // 11111100000000000000000000000000
#define IMMEDIATE_BITS 0xFFFF // 00000000000000001111111111111111
#define SHORT_IMMEDIATE_BITS 0x7FF // 00000000000000000000011111111111
#define S_BITS 0x3e00000 // 00000011111000000000000000000000
#define T_BITS 0x1f0000 // 00000000000111110000000000000000
#define D_BITS 0xf800 // 00000000000000001111100000000000
// Contains bit masks for instructions for the immediate field.
enum immediate_mask {
im_add = 0x20u, // 100000
im_sub = 0x22u, // 100010
im_and = 0x24u, // 100100
im_or = 0x25u, // 100101
im_slt = 0x2au, // 101010
im_mul = 0x2u, // 000010
im_syscall = 0xcu // 001100
};
// Contains bit masks for the pattern field.
enum pattern_mask {
pm_add = 0x0u, // 000000
pm_sub = 0x0u, // 000000
pm_and = 0x0u, // 000000
pm_or = 0x0u, // 000000
pm_slt = 0x0u, // 000000
pm_mul = 0x1cu, // 011100
pm_beq = 0x4u, // 000100
pm_bne = 0x5u, // 000101
pm_addi = 0x8u, // 001000
pm_slti = 0xau, // 001010
pm_andi = 0xcu, // 001100
pm_ori = 0xdu, // 001101
pm_lui = 0xfu, // 001111
};
// Contains an enum representing instructions.
enum instructions {
add,
sub,
and,
or,
slt,
mul,
beq,
bne,
addi,
slti,
andi,
ori,
lui,
syscall
};
// Functions which extract bitfields from an instruction.
uint32_t get_i(const uint32_t instr);
uint32_t get_p(const uint32_t instr);
uint32_t get_d(const uint32_t instr);
uint32_t get_t(const uint32_t instr);
uint32_t get_s(const uint32_t instr);
// Functions which emulate mips instructions.
void mips_add(const uint32_t instr, uint32_t registers[32]);
void mips_sub(const uint32_t instr, uint32_t registers[32]);
void mips_and(const uint32_t instr, uint32_t registers[32]);
void mips_or(const uint32_t instr, uint32_t registers[32]);
void mips_slt(const uint32_t instr, uint32_t registers[32]);
void mips_mul(const uint32_t instr, uint32_t registers[32]);
void mips_beq(FILE *const fptr, const uint32_t instr, uint32_t registers[32]);
void mips_bne(FILE *const fptr, const uint32_t instr, uint32_t registers[32]);
void mips_addi(const uint32_t instr, uint32_t registers[32]);
void mips_slti(const uint32_t instr, uint32_t registers[32]);
void mips_andi(const uint32_t instr, uint32_t registers[32]);
void mips_ori(const uint32_t instr, uint32_t registers[32]);
void mips_lui(const uint32_t instr, uint32_t registers[32]);
int mips_syscall(uint32_t registers[32]);
#endif
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