public int getTargetOffset() {
    return target.getAddress() - getAddress();
  }
Gets the branch offset of this instruction. This is only valid to call if both this and the
target instruction each has been assigned an address, and it is merely a convenient shorthand
for {@code getTargetAddress() - getAddress()}.

@return the branch offset
android/android_framework/dex-maker/src/main/java/com/android/dx/dex/code/TargetInsn.java