Shared compare lanes for dependency wake up in a pair-based issue queue

摘要

An apparatus for shared compare lanes for dependency wakeup in a double issue queue includes a source dependency module that determines a number of source dependencies for two instructions to be paired in a row of a double issue queue of a processor. A source dependency includes an unavailable status of a dependent source for data required by the two instructions where the data is produced by another instruction. The apparatus includes a pairing determination module that writes each of the two instructions into a separate row of the double issue queue in response to the source dependency module determining that the number of source dependencies is greater than a source dependency maximum and pairs the two instructions in one row of the double issue queue in response to the source dependency module determining that the number of source dependencies is less than or equal to the source dependency maximum.