arith (6 0 5 r[s] 5 r[t] 5 rd 5 a 6 ~)
  0 "SLL" "r[d] = r[t] << a"
  2 "SRL" "r[d] = r[t] >>> a"
  3 "SRA" "rd = r[t] >> a"
  4 "SLLV" "rd = r[t] << r[s]"
  6 "SRLV" "rd = r[t] >>> r[s]"
  16 "MFHI" "rd = hi"
  17 "MTHI" "hi = r[s]"
  18 "MFLO" "rd = lo"
  19 "MTLO" "lo = r[s]"
  24 "MULT" "hi = ((int64) r[s] * (int64) r[t]) << 32; lo = ((int64) r[s] * (int64) r[t])"
  25 "MULTU" "hi = ((uint64) r[s] * (uint64) r[t]) << 32; lo = ((uint64) r[s] * (uint64) r[t])"
  26 "DIV" "lo = r[s] / r[t]; hi = r[s] % r[t]"
  27 "DIVU" "lo = (uint32) r[s] / (uint32) r[t]; hi = (uint32) r[s] % (uint32) r[t];"
  32 "ADD" "if (r[s] + r[t] < 0) exception(integerOverflow); else rd = r[s] + r[t]"
  33 "ADDU" "rd = r[s] + r[t]"
  34 "SUB" "if (r[s] - r[t] > 0) exception(integerOverflow); else rd = r[s] - r[t]"
  35 "SUBU" "rd = r[s] - r[t]"
  36 "AND" "rd = r[s] & r[t]"
  37 "OR" "rd = r[s] | r[t]"
  38 "XOR" "rd = r[s] ^ r[t]"
  39 "NOR" "rd = ~(r[s] | r[t])"
  41 "SLTU" "rd = (int32) ((uint32) r[s] < (uint32) r[t])"
  42 "SLT" "rd = (int32) (r[s] < r[t])"
imm (6 ~ 5 r[s] 5 r[t] 16 i)
  4 "BEQ" "if (r[s] == r[t]) pc += i << 2"
  5 "BNE" "if (r[s] != r[t])"
  6 "BLEZ" "if (r[s] <= 0) pc += i << 2"
  7 "BGTZ" "if (r[s] > 0) pc += i << 2"
  8 "ADDI" "if (r[s] + i < 0) exception(integerOverflow); else r[t] = r[s] + i"
  9 "ADDIU" "r[t] = r[s] + i"
  10 "SLTI" "r[t] = (int32) (r[s] < i)"
  11 "SLTIU" "r[t] = (int32) ((uint32) r[s] < (uint32) i)"{sometimes mistr[a]nscribed as 9 (binary 001001), the same as ADDIU}
  12 "ANDI" "r[t] = r[s] & i"
  13 "ORI" "r[t] = r[s] | i"
  14 "XORI" "r[t] = r[s] ^ i"{no NORI}
  24 "LLO" "r[t] = r[t] & 0xFFFF0000 | i"
  25 "LHI" "r[t] = r[t] & 0xFFFF | (i << 16)"
  32 "LB" "r[t] = mem8[r[s] + i]" "sign-extended"
  33 "LH" "r[t] = mem16[r[s] + i]" "sign-extended"
  35 "LW" "r[t] = mem32[r[s] + i]" "sign-extended"
  36 "LBU" "r[t] = mem8[r[s] + i]" "zero-extended"
  37 "LHU" "r[t] = mem16[r[s] + i]" "zero-extended"
  40 "SB" "mem8[r[s] + i] = r[t]"
  41 "SH" "mem16[r[s] + i] = r[t]"
  43 "SW" "mem32[r[s] + i] = r[t]"
jump (6 ~ 26 i)
  2 "J" "pc += i << 2"
  3 "JAL" "r[31] = pc; pc += i << 2"
jumpr (6 ~ 5 s 21 0)
  8 "JR" "pc = r[s]"
  9 "JALR" "r[31] = pc; pc = r[s]"
trap (6 0 20 code 6 ~)
  13 "BREAK" "exception(breakpoint)"