Abstract: A method in a computer-aided design system for generating a functional design model of a processor, is described herein. The method comprises detecting memory address information corresponding to accessed data in a first instruction, and detecting memory address information corresponding to accessed data in a second instruction. The method further comprises comparing the memory address information corresponding to the first instruction and the memory address information corresponding to the second instruction, and detecting, based on the comparison, that the accessed data in the first instruction and the accessed data in the second instruction are in a same data range of the memory device. In addition the method comprise executing the second instruction using the accessed data from the first instruction and detecting an error from the execution of the second instruction.

Abstract: A computer system assigns a particular counter from among a plurality of counters currently in a counter free pool to count a number of mappings of logical registers from among a plurality of logical registers to a particular physical register from among a plurality of physical registers, responsive to an execution of an instruction by a mapper unit mapping at least one logical register from among the plurality of logical registers to the particular physical register, wherein the number of the plurality of counters is less than a number of the plurality of physical registers. The computer system, responsive to the counted number of mappings of logical registers to the particular physical register decremented to less than a minimum value, returns the particular counter to the counter free pool.

Abstract: Managing a global completion table used to track progress of groups of instructions, in which each group of instructions includes one or more instructions. Entries of the global completion table are allocated to the groups of instructions from a freelist of entries. That is, entries are allocated from a pool of entries, rather than allocating entries in-order in a circular queue.

Abstract: Managing a global completion table used to track progress of groups of instructions, in which each group of instructions includes one or more instructions. Entries of the global completion table are allocated to the groups of instructions from a freelist of entries. That is, entries are allocated from a pool of entries, rather than allocating entries in-order in a circular queue.

Abstract: Embodiments include issuing dynamic issue masks for processor hang prevention. Aspects include storing an instruction in an issue queue for execution by an execution unit, the instruction including a default issue mask. Aspects further include determining whether the instruction in the issue queue is likely to be rescinded by the execution unit. Based on determining that the instruction is not likely to be rescinded by the execution unit, aspects include issuing the instruction to the execution unit with the default issue mask. Based on determining that the instruction is likely to be rescinded by the execution unit, aspects include issuing the instruction to the execution unit with a likely to be rescinded issue mask.

Abstract: Embodiments include issuing dynamic issue masks for processor hang prevention. Aspects include storing an instruction in an issue queue for execution by an execution unit, the instruction including a default issue mask. Aspects further include determining whether the instruction in the issue queue is likely to be rescinded by the execution unit. Based on determining that the instruction is not likely to be rescinded by the execution unit, aspects include issuing the instruction to the execution unit with the default issue mask. Based on determining that the instruction is likely to be rescinded by the execution unit, aspects include issuing the instruction to the execution unit with a likely to be rescinded issue mask.

Abstract: A computer implemented method of processing instructions of a computer program. The method comprises providing at least two copies of program status data; identifying a first update instruction of the instructions that writes to at least one field of the program status data; and associating the first update instruction with a first copy of the at least two copies of program status data.

Abstract: A computer system assigns a particular counter from among a plurality of counters currently in a counter free pool to count a number of mappings of logical registers from among a plurality of logical registers to a particular physical register from among a plurality of physical registers, responsive to an execution of an instruction by a mapper unit mapping at least one logical register from among the plurality of logical registers to the particular physical register, wherein the number of the plurality of counters is less than a number of the plurality of physical registers. The computer system, responsive to the counted number of mappings of logical registers to the particular physical register decremented to less than a minimum value, returns the particular counter to the counter free pool.

Abstract: A method and a computer program for a processor simultaneously handle multiple instructions at a time. The method includes labeling of an instruction ending a relevant sample interval from a plurality of such instructions. Further, the method utilizes a buffer to store N more number of entries than actually required, wherein, N refers to the number of RI instructions younger than the instruction ending a sample interval. Further, the method also includes the step of recording relevant instrumentation data corresponding to the sample interval and providing the instrumentation data in response to identification of the sample interval.

Abstract: A method for managing cache memory including receiving an instruction fetch for an instruction stream in a cache memory, wherein the instruction fetch includes an instruction fetch reference tag for the instruction stream and the instruction stream is at least partially included within a cache line, comparing the instruction fetch reference tag to a previous instruction fetch reference tag, maintaining a cache replacement status of the cache line if the instruction fetch reference tag is the same as the previous instruction fetch reference tag, and upgrading the cache replacement status of the cache line if the instruction fetch reference tag is different from the previous instruction fetch reference tag, whereby the cache replacement status of the cache line is upgraded if the instruction stream is independently fetched more than once. A corresponding system and computer program product.

Abstract: A computer processing system method and apparatus having a processor employing an operating system (O/S) multi-task control between multiple user programs and which ensures that the programs do not interfere with each other, said computing processing system having a branch multiple page size prediction mechanism which predicts a page size along with a branch direction and a branch target of a branch for instructions of a processing pipeline, having a branch target buffer (BTB) predicting the branch target, said branch prediction mechanism storing recently used instructions close to the processor in a local cache, and having a translation look-aside buffer TLB mechanism which tracks the translation of the most recent pages and supports multiple page sizes.

Abstract: A computer system assigns a particular counter from among a plurality of counters currently in a counter free pool to count a number of mappings of logical registers from among a plurality of logical registers to a particular physical register from among a plurality of physical registers, responsive to an execution of an instruction by a mapper unit mapping at least one logical register from among the plurality of logical registers to the particular physical register, wherein the number of the plurality of counters is less than a number of the plurality of physical registers. The computer system, responsive to the counted number of mappings of logical registers to the particular physical register decremented to less than a minimum value, returns the particular counter to the counter free pool.

Abstract: A mapper unit of an out-of-order processor assigns a particular counter currently in a counter free pool to count a number of mappings of logical registers to a particular physical register from among multiple physical registers, responsive to an execution of an instruction by the mapper unit mapping at least one logical register to the particular physical register. The number of counters is less than the number of physical registers. The mapper unit, responsive to the counted number of mappings of logical registers to the particular physical register decremented to less than a minimum value, returns the particular counter to the counter free pool.

Abstract: A method of changing a value of associated with a logical address in a computing device. The method includes: receiving an instruction at an instruction decoder, the instruction including a target register expressed as a logical value; determining at an instruction decoder that a result of the instruction is to set the target register to a constant value, the target register being in a physical register file associated with an execution unit; and mapping, in a register mapper, the logical address to a location represented by a special register tag.

Abstract: A method of changing a value of associated with a logical address in a computing device. The method includes: receiving an instruction at an instruction decoder, the instruction including a target register expressed as a logical value; determining at an instruction decoder that a result of the instruction is to set the target register to a constant value, the target register being in a physical register file associated with an execution unit; and mapping, in a register mapper, the logical address to a location represented by a special register tag.

Abstract: A method and information processing system manage load and store operations that can be executed out-of-order. At least one of a load instruction and a store instruction is executed. A determination is made that an operand store compare hazard has been encountered. An entry within an operand store compare hazard prediction table is created based on the determination. The entry includes at least an instruction address of the instruction that has been executed and a hazard indicating flag associated with the instruction. The hazard indicating flag indicates that the instruction has encountered the operand store compare hazard. When a load instruction is associated with the hazard indicating flag, the load instruction becomes dependent upon all store instructions associated with a substantially similar hazard indicating flag.

Abstract: A method and information processing system manage load and store operations executed out-of-order. At least one of a load instruction and a store instruction is executed. A determination is made that an operand store compare hazard has been encountered. An entry within an operand store compare hazard prediction table is created based on the determination. The entry includes at least an instruction address of the instruction that has been executed and a hazard indicating flag associated with the instruction. The hazard indicating flag indicates that the instruction has encountered the operand store compare hazard. When a load instruction is associated with the hazard indicating flag the load instruction becomes dependent upon all store instructions associated with a substantially similar flag.

Abstract: A method and information processing system manage load and store operations executed out-of-order. At least one of a load instruction and a store instruction is executed. A determination is made that an operand store compare hazard has been encountered. An entry within an operand store compare hazard prediction table is created based on the determination. The entry includes at least an instruction address of the instruction that has been executed and a hazard indicating flag associated with the instruction. The hazard indicating flag indicates that the instruction has encountered the operand store compare hazard. When a load instruction is associated with the hazard indicating flag the load instruction becomes dependent upon all store instructions associated with a substantially similar flag.

Abstract: A system and method for collecting instrumentation data in a processor with a pipelined instruction execution stages arranged in an out-of-order execution architecture. One instruction group in a Global Completion Table is marked as a tagged group. Instrumentation data is stored for processing stages processing instructions associated with the tagged group. Sample signal pulses trigger a determination of whether the tagged group is the next-to-complete instruction group. When the sample pulse occurs at a time when the tagged group is the next-to-complete group, the instrumentation data is written as an output. Instrumentation data present during sample pulses that occur when the tagged group is not the next-to-complete group is optionally discarded. Sample pulses are generated at a rate equal to the desired sample rate times the number of groups in the global completion table to better ensure occurrence of a next-to-complete tagged group.

Abstract: Embodiments of the invention include a method of synchronizing translation changes in a processor including a translation lookaside buffer, the method including setting a control bit to enable blocking of all fetch requests that miss the translation lookaside buffer without changing a translation state of the current process; if there is at least one pending translation, then waiting for completion of the at least one pending translation; and resetting the control bit. A processor and a computer program product are provided.