public static DecodedInstruction decode(CodeInput in) throws EOFException {
    int opcodeUnit = in.read();
    int opcode = Opcodes.extractOpcodeFromUnit(opcodeUnit);
    InstructionCodec format = OpcodeInfo.getFormat(opcode);

    return format.decode(opcodeUnit, in);
  }
Decodes an instruction from the given input source.
android/android_framework/dex-maker/src/main/java/com/android/dx/io/instructions/DecodedInstruction.java