Area and power efficient mechanism to wakeup store-dependent loads according to store drain merges

Abstract

A computer system, includes a store queue that holds store entries and a load queue that holds load entries sleeping on a store entry. A processor detects a store drain merge operation call and generates a pair of store tags comprising a first store tag corresponding to a first store entry to be drained and a second store tag corresponding to a second store entry to be drained. The processor determines the pair of store tags an even-type store tag or an odd-type store tag. The processor disables the odd store tag included in the even-type store tag pair when detecting the even-type store tag pair, and wakes up a first load entry dependent on the even store tag and a second load entry dependent on the odd store tag based on the even store tag included in the even-type store tag pair while the odd store tag is disabled.