The CS61c course staff wrote the majority of this code, Frederick James Meyer and I edited the assembler to support SIMD and slti. That is to say, he edited the assembler while I caught his Python bugs and made the repo.

Here's the full set of instructions and opcodes this assembler will put into machine code for you. We didn't change anything critical for the project.

opcodes:
  'disp':1,
  'lui':2,
  'ori':3,
  'addi':4,
  'andi':5,
  'jal':6,
  'j':7,
  'jr':8,
  'beq':9,
  'bne':10,
  'lw':11,
  'sw':12,
  'slti':13,
  'simd':14,


functs:
  'or':0,
  'and':1,
  'add':2,
  'sub':3,
  'sllv':4,
  'srlv':5,
  'srav':6,
  'slt':7,
  '_simd_or':0,
  '_simd_and':1,
  '_simd_add':2,
  '_simd_sub':3,
  '_simd_sllv':4,
  '_simd_srlv':5,
  '_simd_srav':6,
  '_simd_slt':7,


If you want to access the SIMD, just go ahead and use funct = 14 and the corresponding funct. 
Remember that this doesn't IMPLEMENT SIMD, this is to help you TEST your SIMD. Have fun, and if we help you catch a bug say thanks!