History buffer with single snoop tag for multiple-field registers

摘要

An approach is provided in which a mapper control unit matches a result instruction tag corresponding to an executed instruction to a history buffer entry's instruction tag. The matched history buffer entry includes multiple history buffer field sets that each include a field set state indicator. The mapper control unit identifies a subset of the history buffer field sets having a valid field set state indicator and stores result data corresponding to the result instruction tag in the identified subset of history buffer field sets. In turn, the mapper control unit restores a subset of a register's fields utilizing content from the subset of history buffer field sets.