International Business Machines Corporation

Cliff Kucharski

Dung Q Nguyen

David R Terry

Susan Elizabeth Eisen

Steven J Battle

Salma Ayub

Brian David Barrick

Sundeep Chadha

Joshua W Bowman

Hung Qui Le

Jing Zhang

Dhivya Jeganathan

Brandon R Goddard

David S Walder

Brian William Thompto

Michael Joseph Genden

James Wilson Bishop

Tu-An T Nguyen

Glenn Owen Kincaid

Marcy Evelyn Byers

Josh Bowman

Albert James Van Norstrand, Jr

Kenneth Lundy Ward

Maureen Anne Delaney

Christopher M Mueller

Sam G Chu

Eula Faye Abalos Tolentino

A method for restoring a mapper of a processor core includes saving first information in a staging latch. The first information represents a newly dispatched first instruction of the processor core and is saved in an entry latch of a save-and-restore buffer. In response to reception of a flush command of the processor core, the restoration of the mapper is begun with the first information from the staging latch without waiting for a comparison of a flush tag of the flush command with the entry latch of the save-and-restore buffer. A processor core configured to perform the method described above is also provided. A processor core is also provided that includes a dispatch, a mapper, a save-and-restore buffer that includes entry latches and is connected to the mapper via at least one pipeline, and a register disposed in the at least one pipeline.

Fast mapper restore for flush in processor

Disclosed is a method for rebalancing blocks of a register file. The method comprises allocating a first set of entries in a first register file to a first hardware thread of a processor core. The method further comprises allocating a second set of entries in a second register file to a second hardware thread of the processor core. The register tags in the first and second register files are compacted such that register tags associated with the first hardware thread are compacted into the first set of entries, and register tags associated with the second hardware thread are compacted into the second set of entries.

Compaction of architected registers in a simultaneous multithreading processor

A computer system, processor, programming instructions and/or method of processing data that includes a main register file having a plurality of entries for storing data; an accumulator register file having a plurality of entries for storing data wherein multiple main register file entries are mapped to one accumulator register file entry in the at least one accumulator register file; a logical register mapper to track and map logical registers to main register file entries, and a history buffer. Processing wide data width instructions includes evicting and restoring information from a single primary entry in the logical register mapper through a single read or write port in the logical register mapper without evicting or restoring the remaining other multiple main register file entries mapped in the accumulator register.

Evicting and restoring information using a single port of a logical register mapper and history buffer in a microprocessor comprising multiple main register file entries mapped to one accumulator register file entry

A computer system, processor, and method for processing information is disclosed that includes at least one computer processor, a register file associated with the at least one processor, preferably a condition register that stores status information, the register file having multiple locations for storing data, multiple ports to write data to and read data from the register file. The system or processor includes an execution area, and the processor is configured to read from all the read ports in a first cycle, and to read from all the read ports in a second cycle. In an embodiment, the execution area includes a staging latch to store data from a first cycle read operation, and in an aspect the computer system is configured to combine the data stored in the staging latch during a first read cycle with the data read from the second cycle.

Fused overloaded register file read to enable 2-cycle move from condition register instruction in a microprocessor

A method, processor and/or system for processing data is disclosed that in an aspect includes providing a physical register file with one or more register file entries for storing data; identifying each physical register file entry with a row identifier to identify the entry row in the physical register file; enabling one or more columns within a target entry row of the physical register file; and revising data in the columns enabled within the target entry row of the physical register file. In an aspect, each physical register file entry is partitioned into a plurality of columns having a bit width and a column mask preferably is used to enable the one or more columns within the target row of the physical register file, and data is revised in only the columns enabled by the column mask.

System and handling of register data in processors

Recovering microprocessor logical register values by: partitioning a register mapper by logical register type; providing a plurality of recovery ports; assigning a logical register type to a recovery port; receiving a restore required instruction; and mapping SRB (save and restore buffer) values to the register mapper by logical register type.

Supporting speculative microprocessor instruction execution

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.

Operation of a multi-slice processor implementing a hardware level transfer of an execution thread

A non-limiting example of a computer-implemented method for file register writes using pointers includes, responsive to a dispatch instruction, storing, at a location in a history buffer, an instruction tag and first data associated with the instruction tag. The method further includes storing a pointer in an issue queue. The pointer points to the location in the history buffer. The method further includes performing a write back of second data using the pointer stored in the issue queue. The write back writes the second data into the location of the history buffer associated with the pointer.

Register file write using pointers

Embodiments include systems, methods, and computer program products for using a multi-tier hang buster for detecting and breaking out of hang conditions in a processor. One method includes determining a plurality of actions available at each of a plurality of tiers used for breaking out of the hang condition in the processor. The method also includes, after detecting the hang condition on a first thread of the processor, performing one or more actions available at a first tier of the plurality of tiers to break out of the hang condition. The method further includes, after performing the one or more actions at the first tier and determining that the hang condition is still present, performing one or more actions available at one or more second tiers of the plurality of tiers to break out of the hang condition.

On-demand multi-tiered hang buster for SMT microprocessor

A computer system includes a dispatch routing network to dispatch a plurality of instructions, and a processor in signal communication with the dispatch routing network. The processor determines a move instruction from the plurality of instructions to move data produced by an older second instruction, and copies a splice target file (STF) tag from a source register of the move instruction to a destination register of the move instruction without physically copying data in a slice target register and without assigning a new STF tag destination to the move instruction.

Implementation of execution compression of instructions in slice target register file mapper

Techniques disclosed herein describe a variable latency pipe for interleaving instruction tags in a processor. According to one embodiment presented herein, an instruction tag is associated with an instruction upon issue of the instruction from the issue queue. One of a plurality of positions in the latency pipe is determined. The pipe stores one or more instruction tags, each associated with a respective instruction. The pipe also stores the instruction tags in a respective position based on the latency of each respective instruction. The instruction tag is stored at the determined position in the pipe.

Variable latency pipe for interleaving instruction tags in a microprocessor

Embodiments include systems, methods, and computer program products for on-demand error detection and correction of registers in a processor. One method includes detecting, before a first instruction is dispatched to an issue queue in the processor, an error in data, associated with the first instruction, stored in an entry of a register file in the processor. The method also includes, after detecting the error, halting the dispatch of the first instruction to the issue queue, and determining whether the entry of the register file has completed. The method further includes determining whether to perform error correction on the register file based on the determination of whether the entry of the register file has completed.

On-demand GPR ECC error detection and scrubbing for a multi-slice microprocessor

Method and system for restoring results to a register file of a processing unit is provided. An instruction is dispatched in a processing slice of the processing unit, targeting a register file, wherein the processing unit includes two or more processing slices, each processing slice including a corresponding history buffer and at least a portion of a register file. The processing unit evicts previous result data from the register file entry to a history buffer corresponding to the processing slice, by writing new result data into the register file entry, in response to the instruction. The processing unit detects a trigger condition relating to a rollback of the processing unit to a previous state, and restores the previous result data from the history buffer to the register file entry, in response to the trigger.

Growing community of inventors

Austin, TX, United States of America

Cliff Kucharski