Store buffer

A method comprising:

• issuing store operations to store items of store data to a data store and load operations to load items of load data from the data store;
• storing, in a store buffer, entry information corresponding to the store operations in advance of the store operations completing, the store buffer comprising a first zone and a second zone;
• and
• looking up, in response to a load operation of the load operations, whether the store buffer contains a corresponding entry corresponding to an older store operation for which target addresses of the load operation and the older store operation satisfy an address comparison condition;
• performing store-to-load forwarding in response to the load operation in response to determining that the corresponding entry is a first type of store buffer entry and the corresponding entry satisfies a forwarding condition;
• and
• delaying processing of the load operation in response to determining that the corresponding entry is a second type of store buffer entry and the corresponding entry satisfies the forwarding condition;
• wherein determining whether the corresponding entry is the first type of store buffer entry or the second type of store buffer entry comprises determining whether the corresponding entry is in the first zone or the second zone.

A non-transitory computer-readable medium to store computer-readable code for fabrication of an apparatus comprising:

• processing circuitry configured to issue store operations to store items of store data to a data store and load operations to load items of load data from the data store;
• a store buffer comprising entries configured to store entry information corresponding to the store operations in advance of the store operations completing, the store buffer comprising a first zone and a second zone;
• and
• store buffer lookup circuitry configured to lookup, in response to a load operation of the load operations, whether the store buffer contains a corresponding entry corresponding to an older store operation for which target addresses of the load operation and the older store operation satisfy an address comparison condition;
• in which:
• the store buffer lookup circuitry is configured to perform store-to-load forwarding in response to the load operation in response to determining that the corresponding entry is a first type of store buffer entry and the corresponding entry satisfies a forwarding condition;
• and
• the store buffer lookup circuitry is configured to delay processing of the load operation in response to determining that the corresponding entry is a second type of store buffer entry and the corresponding entry satisfies the forwarding condition;
• wherein determining whether the corresponding entry is the first type of store buffer entry or the second type of store buffer entry comprises determining whether the corresponding entry is in the first zone or the second zone.