Abstract: Techniques for selectively executing a lock instruction speculatively or non-speculatively based on lock address prediction and/or temporal lock prediction. including methods an devices for locking an entry in a memory device. In some techniques, a lock instruction executed by a thread for a particular memory entry of a memory device is detected. Whether contention occurred for the particular memory entry during an earlier speculative lock is detected on a condition that the lock instruction comprises a speculative lock instruction. The lock is executed non-speculatively if contention occurred for the particular memory entry during an earlier speculative lock. The lock is executed speculatively if contention did not occur for the particular memory entry during an earlier speculative lock.

Abstract: An arithmetic unit performs store-to-load forwarding based on predicted dependencies between store instructions and load instructions. In some embodiments, the arithmetic unit maintains a table of store instructions that are awaiting movement to a load/store unit of the instruction pipeline. In response to receiving a load instruction that is predicted to be dependent on a store instruction stored at the table, the arithmetic unit causes the data associated with the store instruction to be placed into the physical register targeted by the load instruction. In some embodiments, the arithmetic unit performs the forwarding by mapping the physical register targeted by the load instruction to the physical register where the data associated with the store instruction is located.

Abstract: An arithmetic unit performs store-to-load forwarding based on predicted dependencies between store instructions and load instructions. In some embodiments, the arithmetic unit maintains a table of store instructions that are awaiting movement to a load/store unit of the instruction pipeline. In response to receiving a load instruction that is predicted to be dependent on a store instruction stored at the table, the arithmetic unit causes the data associated with the store instruction to be placed into the physical register targeted by the load instruction. In some embodiments, the arithmetic unit performs the forwarding by mapping the physical register targeted by the load instruction to the physical register where the data associated with the store instruction is located.

Abstract: An arithmetic unit performs store-to-load forwarding based on predicted dependencies between store instructions and load instructions. In some embodiments, the arithmetic unit maintains a table of store instructions that are awaiting movement to a load/store unit of the instruction pipeline. In response to receiving a load instruction that is predicted to be dependent on a store instruction stored at the table, the arithmetic unit causes the data associated with the store instruction to be placed into the physical register targeted by the load instruction. In some embodiments, the arithmetic unit performs the forwarding by mapping the physical register targeted by the load instruction to the physical register where the data associated with the store instruction is located.

Abstract: Techniques for improving execution of a lock instruction are provided herein. A lock instruction and younger instructions are allowed to speculatively retire prior to the store portion of the lock instruction committing its value to memory. These instructions thus do not have to wait for the lock instruction to complete before retiring. In the event that the processor detects a violation of the atomic or fencing properties of the lock instruction prior to committing the value of the lock instruction, the processor rolls back state and executes the lock instruction in a slow mode in which younger instructions are not allowed to retire until the stored value of the lock instruction is committed. Speculative retirement of these instructions results in increased processing speed, as instructions no longer need to wait to retire after execution of a lock instruction.

Abstract: Techniques for selectively executing a lock instruction speculatively or non-speculatively based on lock address prediction and/or temporal lock prediction. including methods an devices for locking an entry in a memory device. In some techniques, a lock instruction executed by a thread for a particular memory entry of a memory device is detected. Whether contention occurred for the particular memory entry during an earlier speculative lock is detected on a condition that the lock instruction comprises a speculative lock instruction. The lock is executed non-speculatively if contention occurred for the particular memory entry during an earlier speculative lock. The lock is executed speculatively if contention did not occur for the particular memory entry during an earlier speculative lock.

Abstract: Techniques for improving execution of a lock instruction are provided herein. A lock instruction and younger instructions are allowed to speculatively retire prior to the store portion of the lock instruction committing its value to memory. These instructions thus do not have to wait for the lock instruction to complete before retiring. In the event that the processor detects a violation of the atomic or fencing properties of the lock instruction prior to committing the value of the lock instruction, the processor rolls back state and executes the lock instruction in a slow mode in which younger instructions are not allowed to retire until the stored value of the lock instruction is committed. Speculative retirement of these instructions results in increased processing speed, as instructions no longer need to wait to retire after execution of a lock instruction.

Abstract: A processor includes a store queue that stores information representing store instructions. In response to retirement of a store instruction, the processor invalidates the corresponding entry in the store queue, thereby indicating that the entry is available to store a subsequent store instruction. The store address is not removed from the queue until the subsequent store instruction is stored. Accordingly, the store address is available for comparison to a dependent load address.

Abstract: An arithmetic unit performs store-to-load forwarding based on predicted dependencies between store instructions and load instructions. In some embodiments, the arithmetic unit maintains a table of store instructions that are awaiting movement to a load/store unit of the instruction pipeline. In response to receiving a load instruction that is predicted to be dependent on a store instruction stored at the table, the arithmetic unit causes the data associated with the store instruction to be placed into the physical register targeted by the load instruction. In some embodiments, the arithmetic unit performs the forwarding by mapping the physical register targeted by the load instruction to the physical register where the data associated with the store instruction is located.

Abstract: A processor includes a store queue that stores information representing store instructions. In response to retirement of a store instruction, the processor invalidates the corresponding entry in the store queue, thereby indicating that the entry is available to store a subsequent store instruction. The store address is not removed from the queue until the subsequent store instruction is stored. Accordingly, the store address is available for comparison to a dependent load address.

Abstract: A system and method for copying and initializing a block of memory. To copy several data entities from a source region of memory to a destination region of memory, an instruction may copy each data entity one at a time. If an aggregate condition is determined to be satisfied, multiple data entities may be copied simultaneously. The aggregate condition may rely on an aggregate data size, the size of the data entities to be copied, and the alignment of the source and destination addresses.

Abstract: A system and method for copying and initializing a block of memory. To copy several data entities from a source region of memory to a destination region of memory, an instruction may copy each data entity one at a time. If an aggregate condition is determined to be satisfied, multiple data entities may be copied simultaneously. The aggregate condition may rely on an aggregate data size, the size of the data entities to be copied, and the alignment of the source and destination addresses.