International Business Machines Corporation

Steven J Battle

Dung Q Nguyen

Brian David Barrick

Joshua W Bowman

Susan Elizabeth Eisen

Brian William Thompto

David R Terry

Brandon R Goddard

Cliff Kucharski

Hung Qui Le

Salma Ayub

Tu-An T Nguyen

Saiful Islam

Sam G Chu

Albert James Van Norstrand, Jr

Eula A Tolentino

Owen Chiang

Khandker Nabil Adeeb

Christopher M Mueller

Sundeep Chadha

Kenneth Lundy Ward

David S Walder

Balaram Sinharoy

Richard James Eickemeyer

Christian Zoellin

Kurt Alan Feiste

Jentje Leenstra

John Barry Griswell, Jr

Dhivya Jeganathan

Nicholas R Orzol

Brendan M Wong

Jamory Hawkins

Kent Li

Brian D Victor

Jing Zhang

Maarten Jakob Boersma

Maureen Anne Delaney

James Wilson Bishop

Andreas Wagner

Niels Fricke

Glenn Owen Kincaid

Binglong Zhang

Thao T Doan

Howard Lawrence Levy

Eula Faye Abalos Tolentino

Eula Faye Tolentino

Provided is a method for assigning register tags to instructions at issue time. The method comprises receiving an instruction for execution by a microprocessor. The method further comprises dispatching the instruction to an issue queue without assigning a register tag to the instruction. The method further comprises determining that the instruction is ready to issue. In response to determining that the instruction is ready to issue, the method comprises assigning an available register tag to the instruction. The method further comprises issuing the instruction.

Assignment of microprocessor register tags at issue time

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

A system, processor, programming product and/or method including: an instruction dispatch unit configured to dispatch instructions of a compare immediate-conditional branch instruction sequence; and a compare register having at least one entry to hold information in a plurality of fields. Operations include: writing information from a first instruction of the compare immediate-conditional branch instruction sequence into one or more of the plurality of fields in an entry in the compare register; writing an immediate field and the ITAG of a compare immediate instruction into the entry in the compare register; writing, in response to dispatching a conditional branch instruction, an inferred compare result value into the entry in the compare register; comparing a computed compare result value to the inferred compare result value stored in the entry in the compare register; and not execute the compare immediate instruction or the conditional branch instruction.

Inferring future value for speculative branch resolution in a microprocessor

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

Aspects of the invention include includes determining a first instruction in a processing pipeline, wherein the first instruction includes a compare instruction, determining a second instruction in the processing pipeline, wherein the second instruction includes a conditional branch instruction relying on the compare instruction, determining a predicted result of the compare instruction, and completing the conditional branch instruction using the predicted result prior to executing the compare instruction.

Inferring future value for speculative branch resolution

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 reading out a plurality of entries in a history buffer prior to initiating a flush recovery process; initiating the flush recovery process; determining which of the history buffer entries read out of the history buffer should be recovered; and sending information associated with the history buffer entries to be recovered to one or more history buffer recovery ports. In one or more embodiments, the history buffer entries are continually read out in response to a processor and history buffer entries read out from the history buffer are directed to a specific history buffer recovery port associated with a mapper of a specific logical register.

Steering a history buffer entry to a specific recovery port during speculative flush recovery lookup in a processor

A computer system, processor, and method for processing information is disclosed that includes partitioning a logical register in the processor into a plurality of ranges of logical register entries based upon the logical register entry, assigning at least one recovery port of a history buffer to each range of logical register entries, initiating a flush recovery process for the processor, and directing history buffer entries to the assigned recovery port based upon the logical register entry associated with the history buffer entry.

Logical register recovery within a processor

In at least one embodiment, a processor includes architected and non-architected register files for buffering operands. The processor additionally includes an instruction fetch unit that fetches instructions to be executed and at least one execution unit. The at least one execution unit is configured to execute a first class of instructions that access operands in the architected register file and a second class of instructions that access operands in the non-architected register file. The processor also includes a mapper circuit that assigns physical registers to the instructions for buffering of operands. The processor additionally includes a dispatch circuit configured, based on detection of an instruction in one of the first and second classes of instructions for which correct operands do not reside in a respective one of the architected and non-architected register files, to automatically initiate transfer of operands between the architected and non-architected register files.

Processor providing intelligent management of values buffered in overlaid architected and non-architected register files

A method, system, and/or processor for processing data is disclosed that includes processing a parent stream, detecting a branch instruction in the parent stream, activating an additional child stream, copying the content of a parent mapper copy of the parent stream to an additional child mapper copy, dispatching instructions for the parent stream and the additional child stream, and executing the parent stream and the additional child stream on different execution slices. In an aspect, a first parent mapper copy is associated and used in connection with executing the parent stream and a second different child mapper copy is associated and used in connection with executing the additional child stream. The method in an aspect includes processing one or more streams and/or one or more threads of execution on one or more execution slices.

Instruction streaming using state migration

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

An approach is provided in which a system writes a set of data into a register file entry that includes a first memory array and a second memory array. The register file entry also includes a set of first write ports corresponding to the first memory array and a set of second write ports corresponding to the second memory array. The system configures a selection bit based on determining that a selected one of the set of first write ports is utilized to store the set of data in the first memory array. In turn, the system reads the set of data out of the first memory array based on the configured selection bit.

Implementing write ports in register-file array cell

A computer system, processor, and method for processing information is disclosed. The system, processor and/or method includes at least one computer processor; a register file associated with the at least one processor, the register file having a plurality of entries for storing data where a whole entry has two halves, the register file having multiple ports to write data to the register file and multiple ports to read data from the register file; and one or more execution units associated with the register file, the execution units configured to read data from the register file and to write data to the register file, wherein the processor is configured to write either scalar data or vector data to a single register file entry.

Thread-based organization of slice target register file entry in a microprocessor to permit writing scalar or vector data to portions of a single register file entry

Growing community of inventors

Austin, TX, United States of America

Steven J Battle