public static int flippedIfOpcode(final int opcode) {
    switch (opcode) {
      case RegOps.IF_EQ:
      case RegOps.IF_NE:
        return opcode;
      case RegOps.IF_LT:
        return RegOps.IF_GT;
      case RegOps.IF_GE:
        return RegOps.IF_LE;
      case RegOps.IF_LE:
        return RegOps.IF_GE;
      case RegOps.IF_GT:
        return RegOps.IF_LT;
      default:
        throw new RuntimeException("Unrecognized IF regop: " + opcode);
    }
  }
Given an IF_* RegOp, returns the right-to-left flipped version. For example, IF_GT becomes
IF_LT.

@param opcode An IF_* RegOp
@return flipped IF Regop
android/android_framework/dex-maker/src/main/java/com/android/dx/rop/code/RegOps.java