Abstract: A simultaneous multithreading processor is configured to select a first thread of the plurality of threads according to a predefined scheme, and access an instruction completion table to determine whether the first thread is eligible to have a first instruction prioritized. Responsive to determining that the first thread is eligible to have the first instruction prioritized, the simultaneous multithreading processor is further configured to execute the first instruction of the first thread using a dedicated prioritization resource.

Abstract: A computer system, processor, and method for processing information is disclosed that includes at least one processor having a main register file, the main register file having a plurality of entries for storing data; one or more execution units including a dense math execution unit; and at least one accumulator register file, the at least one accumulator register file associated with the dense math execution unit. The processor in an embodiment is configured to process data in the dense math execution unit where the results of the dense math execution unit are written to a first group of one or more accumulator register file entries, and after a checkpoint boundary is crossed based upon, for example, the number “N” of instructions dispatched after the start of the checkpoint, the results of the dense math execution unit are written to a second group of one or more accumulator register file entries.

Abstract: 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.

Abstract: A processor configured to manage a transaction memory (TM) state. The processor is configured to receive a first instruction indicating a start of a speculative transaction and update a register file with a speculative transaction memory (TM) state corresponding to the speculative transaction. The processor is further configured to determine whether or not the register file is able to store the entirety of speculative TM state. If the register file is unable to store the entirety of the speculative TM state, the processor is configured to copy a previous TM (pre-TM) state from the register file to a memory which is external to the processor. Further, the processor may be configured to complete updating the register file with the speculative TM state after the pre-TM state has been copied from the register file to the memory.

Abstract: A computer-implemented method, computer program product, and computer processing system are provided. The method includes processing, by a superscalar processing pipeline, respective sets of instructions in respective instruction processing cycles using an Instruction Completion Table (ICT) with a Ready-To-Complete (RTC) vector. The ICT includes a plurality of entries, each corresponding to a respective one of the instructions. A Next-To-Complete (NTC) instruction from among the respective sets of instructions is computed using the RTC vector.

Abstract: 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.

Abstract: A method, processor and system for processing data is disclosed that includes evicting one or more evicted fields from a logical register mapper; receiving, by a history buffer, the one or more evicted fields from the logical register mapper; determining whether two or more of the evicted fields from the mapper qualify to be written to a single entry in the history buffer; and in response to the two or more evicted fields qualifying, writing the two or more qualifying evicted fields received from the mapper to a single entry in the qualified history buffer. The method, processor, and/or system further includes in an embodiment, remapping the one or more qualified evicted fields, and further, in response to the two or more evicted fields not qualifying to be written to a single entry in the history buffer, writing the two or more evicted fields to multiple history buffer entries.

Abstract: 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.

Abstract: Systems, methods, and computer-readable media are described for performing speculative execution of both paths/branches of a weakly predicted branch instruction. A branch instruction may be fetched from an instruction queue and determined to be a weakly predicted branch instruction, in which case, both paths of the branch instruction may be dispatched and speculatively executed. When the actual path taken becomes known, instructions corresponding to the path not taken may be flushed. Instructions from both paths of a weakly predicted branch instruction that are speculatively executed may be dispatch and executed in an interleaved manner.

Abstract: A method, processor and system for processing data is disclosed that includes evicting one or more evicted fields from a logical register mapper; receiving, by a history buffer, the one or more evicted fields from the logical register mapper; determining whether two or more of the evicted fields from the mapper qualify to be written to a single entry in the history buffer; and in response to the two or more evicted fields qualifying, writing the two or more qualifying evicted fields received from the mapper to a single entry in the qualified history buffer. The method, processor, and/or system further includes in an embodiment, remapping the one or more qualified evicted fields, and further, in response to the two or more evicted fields not qualifying to be written to a single entry in the history buffer, writing the two or more evicted fields to multiple history buffer entries.

Abstract: 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.

Abstract: Method and apparatus for completing atomic instructions in a microprocessor may be provided by identifying from a program-ordered Instruction Completion Table (ICT) a last entry in a completion window of instructions for completion in a current clock cycle of a processor; in response to determining that the last entry includes an atomic instruction that straddles the completion window: excluding the last entry from completion during the current clock cycle; completing instructions in the completion window for the current clock cycle; and shifting the completion window to include the last entry and a next entry adjacent to the last entry in the ICT in a next clock cycle.

Abstract: A processor configured to manage a transaction memory (TM) state. The processor is configured to receive a first instruction indicating a start of a speculative transaction and update a register file with a speculative transaction memory (TM) state corresponding to the speculative transaction. The processor is further configured to determine whether or not the register file is able to store the entirety of speculative TM state. If the register file is unable to store the entirety of the speculative TM state, the processor is configured to copy a previous TM (pre-TM) state from the register file to a memory which is external to the processor. Further, the processor may be configured to complete updating the register file with the speculative TM state after the pre-TM state has been copied from the register file to the memory.

Abstract: Systems, methods, and computer-readable media are described for performing instruction execution using an instruction completion table (ICT) that is configured to accommodate shared ICT entries. A shared ICT entry maps to multiple instructions such as, for example, two instructions. Each shared ICT entry may be referenced by an even instruction tag (ITAG) and an odd ITAG that correspond to respective instructions that have been grouped together in the shared ICT entry. The instructions corresponding to a given shared ICT entry can be executed and finished independently of one another. A shared ICT entry is completed when each execution of each instruction corresponding to the shared ICT entry has finished and when all prior ICT entries have completed. Also described herein are system, methods, and computer-readable media for flushing instructions in shared ICT entries in response to execution of a branch instruction.

Abstract: A computer system, processor, and method for processing information is disclosed that includes at least one computer processor for processing instructions, the processor having a history buffer having a plurality of entries for storing information associated with a processor instruction evicted from a logical register, the history buffer having at least one recovery port; a logical register mapper for recovering information from the history buffer, the mapper having restore ports to recover information from the history buffer; and a restore multiplexor configured to receive as inputs information from one or more of the history buffer recovery ports, and configured to output information to one or more of the logical register mapper restore ports. The processor, system and/or method configured to improve flush recovery bandwidth.

Abstract: 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.

Abstract: Method and apparatus for a completion mechanism for a microprocessor are provided by identifying entries in a section of an Instruction Completion Table (ICT) that are marked as ready to complete via corresponding Ready to Complete (RTC) status bits; determining a tail pointer indicating a start of the entries in the ICT that are ready for completion; determining a head pointer that indicates an end of the entries in the ICT that are ready for completion; completing instructions included in the entries between the tail pointer and the head pointer; and updating the tail pointer to a value of the head pointer for a subsequent instruction completion round.

Abstract: Method and apparatus for a completion mechanism for a microprocessor are provided by marking entries in a section of an Instruction Completion Table (ICT) as ready to complete using corresponding Ready to Complete (RTC) status bits; determining a tail pointer indicating a start of the entries in the ICT that are ready for completion in a current clock cycle; performing a counting leading ones on an RTC vector that organizes the RTC status bits according to a program order for completing the entries to determine a count leading ones pointer that indicates an end of the entries in the ICT that are ready for completion in the current clock cycle; completing instructions included in the entries between the tail pointer and the count leading ones pointer in one clock cycle; and updating the tail pointer to a value of the count leading ones pointer for a subsequent clock cycle.

Abstract: Method and apparatus for stopping completions using stop codes in an instruction completion table are provided by during a first clock cycle, in response to determining that a given entry in an Instruction Completion Table (ICT) is finalized and is associated with a stop code, completing, according to a program order, instructions included in one or more finalized entries of the ICT located in the ICT before the given entry; during a second clock cycle, after completing the instructions, performing exception processing for a special instruction included in the given entry; and during a third clock cycle, after processing the special instruction, completing, according to the program order, additional instructions in one or more finalized entries located in the ICT after the given entry.

Abstract: 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.