public boolean isCommutative() {
    switch (opcode) {
      case RegOps.AND:
      case RegOps.OR:
      case RegOps.XOR:
      case RegOps.ADD:
      case RegOps.MUL:
        return true;
      default:
        return false;
    }
  }
Gets whether this opcode is commutative (the order of its sources are unimportant) or not. All
commutative Rops have exactly two sources and have no branchiness.

@return true if rop is commutative
android/android_framework/dex-maker/src/main/java/com/android/dx/rop/code/Rop.java