Abstract: An execution unit circuit for use in a processor core provides efficient use of area and energy by reducing the per-entry storage requirement of a load-store unit issue queue. The execution unit circuit includes a recirculation queue that stores the effective address of the load and store operations and the values to be stored by the store operations. A queue control logic controls the recirculation queue and issue queue so that that after the effective address of a load or store operation has been computed, the effective address of the load operation or the store operation is written to the recirculation queue and the operation is removed from the issue queue, so that address operands and other values that were in the issue queue entry no longer require storage. When a load or store operation is rejected by the cache unit, it is subsequently reissued from the recirculation queue.

Abstract: Technology for fusing certain load instructions and compare-immediate instructions in a computer processor having a load-store architecture with respect to transferring data between memory and registers of the computer processor. In some embodiments the load and compare-immediate instructions are consecutive. In some embodiments, the instructions are only merged if: (i) the respective RA and RT fields of the two instructions match; (ii) the immediate field of the compare-immediate instruction has a certain value, or falls within a range of certain values; and/or (iii) the instructions are received in a consecutive manner.

Abstract: An execution unit circuit for use in a processor core provides efficient use of area and energy by reducing the per-entry storage requirement of a load-store unit issue queue. The execution unit circuit includes a recirculation queue that stores the effective address of the load and store operations and the values to be stored by the store operations. A queue control logic controls the recirculation queue and issue queue so that that after the effective address of a load or store operation has been computed, the effective address of the load operation or the store operation is written to the recirculation queue and the operation is removed from the issue queue, so that address operands and other values that were in the issue queue entry no longer require storage. When a load or store operation is rejected by the cache unit, it is subsequently reissued from the recirculation queue.

Abstract: An execution unit circuit for use in a processor core provides efficient use of area and energy by reducing the per-entry storage requirement of a load-store unit issue queue. The execution unit circuit includes a recirculation queue that stores the effective address of the load and store operations and the values to be stored by the store operations. A queue control logic controls the recirculation queue and issue queue so that that after the effective address of a load or store operation has been computed, the effective address of the load operation or the store operation is written to the recirculation queue and the operation is removed from the issue queue, so that address operands and other values that were in the issue queue entry no longer require storage. When a load or store operation is rejected by the cache unit, it is subsequently reissued from the recirculation queue.

Abstract: Technology for fusing certain load instructions and compare-immediate instructions in a computer processor having a load-store architecture with respect to transferring data between memory and registers of the computer processor. In some embodiments the load and compare-immediate instructions are consecutive. In some embodiments, the instructions are only merged if: (i) the respective RA and RT fields of the two instructions match; (ii) the immediate field of the compare-immediate instruction has a certain value, or falls within a range of certain values; and/or (iii) the instructions are received in a consecutive manner.

Abstract: Provided is a method for fusing store instructions in a microprocessor. The method includes identifying two instructions in an execution pipeline of a microprocessor. The method further includes determining that the two instructions meet a fusion criteria. In response to determining that the two instructions meet the fusion criteria, the two instructions are recoded into a fused instruction. The fused instruction is executed.

Abstract: An execution unit circuit for use in a processor core provides efficient use of area and energy by reducing the per-entry storage requirement of a load-store unit issue queue. The execution unit circuit includes a recirculation queue that stores the effective address of the load and store operations and the values to be stored by the store operations. A queue control logic controls the recirculation queue and issue queue so that that after the effective address of a load or store operation has been computed, the effective address of the load operation or the store operation is written to the recirculation queue and the operation is removed from the issue queue, so that address operands and other values that were in the issue queue entry no longer require storage. When a load or store operation is rejected by the cache unit, it is subsequently reissued from the recirculation queue.

Abstract: Technology for fusing an add-immediate instruction with a load-immediate instruction (or store-immediate instruction) in a microprocessor. This can result in quicker address generation while performing a load and store operation.

Abstract: In an approach for decreasing a rate of logic voltage level transitions in a multiplexor, one of a plurality of inputs to a multiplexor is selected with a first multiplexor select value at a first clock, wherein each input to the multiplexor is identified as one of i) valid and ii) invalid and the first multiplexor select value is latched in a latch until the first multiplexor select value is replaced by a second multiplexor select value. The second multiplexor select value is determined. The second multiplexor select value is applied to the multiplexor at a second clock if and only if the second multiplexor select value is different from the first multiplexor select value and the second multiplexor select value selects a valid input, wherein the second clock follows the first clock. Subsequent to applying the second multiplexor select value, the second multiplexor value is latched in the latch.

Abstract: An execution unit circuit for use in a processor core provides efficient use of area and energy by reducing the per-entry storage requirement of a load-store unit issue queue. The execution unit circuit includes a recirculation queue that stores the effective address of the load and store operations and the values to be stored by the store operations. A queue control logic controls the recirculation queue and issue queue so that that after the effective address of a load or store operation has been computed, the effective address of the load operation or the store operation is written to the recirculation queue and the operation is removed from the issue queue, so that address operands and other values that were in the issue queue entry no longer require storage. When a load or store operation is rejected by the cache unit, it is subsequently reissued from the recirculation queue.

Abstract: Operation of a multi-slice processor that includes execution slices and a dispatch network of the multi-slice processor implementing a hardware level transfer of an execution thread between execution slices. Operation of such a multi-slice processor includes responsive to a thread switch signal: halting dispatch of one or more instructions retrieved from an instruction cache; generating a plurality of instructions to transfer an execution thread from a first execution slice to a second execution slice; and dispatching the plurality of instructions instead of the one or more instructions retrieved from the instruction cache; and transferring, in dependence upon execution of the plurality of instructions from the thread switching instruction generator, the execution thread from the first execution slice to the second execution slice.

Abstract: Processor instruction scheduling by: providing a set of program instructions, selecting instructions for reordering from the set of program instructions, reordering the instructions according to instruction properties, assigning sequential instruction tags to the instructions, tagging the instructions for completion as a group in a completion table; and executing the instructions.

Abstract: Fast issuance and execution of a multi-width instruction across multiple slices in a parallel slice processor core is supported in part through the use of an early notification signal passed between issue logic associated with multiple slices handling that multi-width instruction coupled with an issuance of a different instruction by the originating issue logic for the early notification signal.

Abstract: Techniques are disclosed for performing issue queue snooping for an asynchronous flush and restore of a history buffer (HB) in a processing unit. One technique includes identifying an entry of the HB to restore to a register file in the processing unit. A restore ITAG of the HB entry is sent to the register file via a first restore bus, and restore data of the HB entry and the restore ITAG is sent to the register file via a second restore bus. After the restore ITAG and restore data are sent, an instruction is dispatched before the register file obtains the restore data. After it is determined that the restore data is still available via the second restore bus, a snooping operation is performed to obtain the restore data from the second restore bus for the dispatched instruction.

Abstract: Handling unaligned load operations, including: receiving a request to load data stored within a range of addresses; determining that the range of addresses includes addresses associated with a plurality of caches, wherein each of the plurality of caches are associated with a distinct processor slice; issuing, to each distinct processor slice, a request to load data stored within a cache associated with the distinct processor slice, wherein the request to load data stored within the cache associated with the distinct processor slice includes a portion of the range of addresses; executing, by each distinct processor slice, the request to load data stored within the cache associated with the distinct processor slice; and receiving, over a plurality of data communications busses, execution results from each distinct processor slice, wherein each data communications busses is associated with one of the distinct processor slices.

Abstract: Processor instruction scheduling by: providing a set of program instructions, selecting instructions for reordering from the set of program instructions, reordering the instructions according to instruction properties, assigning sequential instruction tags to the instructions, tagging the instructions for completion as a group in a completion table; and executing the instructions.

Abstract: Handling unaligned load operations, including: receiving a request to load data stored within a range of addresses; determining that the range of addresses includes addresses associated with a plurality of caches, wherein each of the plurality of caches are associated with a distinct processor slice; issuing, to each distinct processor slice, a request to load data stored within a cache associated with the distinct processor slice, wherein the request to load data stored within the cache associated with the distinct processor slice includes a portion of the range of addresses; executing, by each distinct processor slice, the request to load data stored within the cache associated with the distinct processor slice; and receiving, over a plurality of data communications busses, execution results from each distinct processor slice, wherein each data communications busses is associated with one of the distinct processor slices.

Abstract: Embodiments herein describe a reservation station (RS) in a processor that merges control data from multiple sources into a merged control data value. Before an instruction issues, the RS gathers and saves control data indicating how the instruction is to be executed. This control data may be saved in control registers. An instruction, however, can update many different types of status control bits in these registers. As such, the RS may store different types of control data for an instruction. Instead of the RS containing multiple registers and data paths for every type of control data, the embodiments herein describe merge logic in the RS that permits control data from different sources to be merged into a single control data value. Once the instruction is issued, the RS passes the merged control data value to an execution unit for processing.

Abstract: A computer processing system is provided. The computer processing system includes a processor configured to insert a move instruction in an instruction scheduling dependency graph generated for operands of the instruction operating on register pairs to ensure operand readiness for all of the operands used by the instruction operating on register pairs.

Abstract: A computer processing system is provided. The computer processing system includes a processor configured to insert a move instruction in an instruction scheduling dependency graph generated for operands of the instruction operating on register pairs to ensure operand readiness for all of the operands used by the instruction operating on register pairs.