+
+ // During this forward scan, at some point it needs to answer the question
+ // "given a pointer to an MI in the current BB, is it located before or
+ // after the current instruction".
+ // To perform this, the following set keeps track of the MIs already seen
+ // during the scan, if a MI is not in the set, it is assumed to be located
+ // after. Newly created MIs have to be inserted in the set as well.