Abstract: A fully associative cache memory, comprising: an array of storage elements; an allocation unit that allocates the storage elements in response to memory accesses that miss in the cache memory. Each memory access has an associated memory access type (MAT) of a plurality of predetermined MATs. Each valid storage element of the array has an associated MAT. For each MAT, the allocation unit maintains: a counter that counts of a number of valid storage elements associated with the MAT; and a corresponding threshold. The allocation unit allocates into any of the storage elements in response to a memory access that misses in the cache, unless the counter of the MAT of the memory access has reached the corresponding threshold, in which case the allocation unit replaces one of the valid storage elements associated with the MAT of the memory access.

Abstract: A microprocessor instruction translator translates a conditional load instruction into at least two microinstructions. An out-of-order execution pipeline executes the microinstructions. To execute a first microinstruction, an execution unit receives source operands from the source registers of a register file and responsively generates a first result using the source operands. To execute a second the microinstruction, an execution unit receives a previous value of the destination register and the first result and responsively reads data from a memory location specified by the first result and provides a second result that is the data if a condition is satisfied and that is the previous destination register value if not. The previous value of the destination register comprises a result produced by execution of a microinstruction that is the most recent in-order previous writer of the destination register with respect to the second microinstruction.

Abstract: A cache memory system including a primary cache and an overflow cache that are searched together using a search address. The overflow cache operates as an eviction array for the primary cache. The primary cache is addressed using bits of the search address, and the overflow cache is addressed by a hash index generated by a hash function applied to bits of the search address. The hash function operates to distribute victims evicted from the primary cache to different sets of the overflow cache to improve overall cache utilization. A hash generator may be included to perform the hash function. A hash table may be included to store hash indexes of valid entries in the primary cache. The cache memory system may be used to implement a translation lookaside buffer for a microprocessor.

Abstract: An asymmetric multi-core processor uses at least two asymmetric cores to collectively support the instructions of an instruction set architecture (ISA). A general-feature core and a special feature core that support different instruction subsets of the ISA. A switch manager detects whether a thread includes an instruction that is not supported by the currently-executing core and, after detecting such an instruction, switches the thread to the other core.

Abstract: A hardware data prefetcher is comprised in a memory access agent, wherein the memory access agent is one of a plurality of memory access agents that share a memory. The hardware data prefetcher includes a prefetch trait that is initially either exclusive or shared. The hardware data prefetcher also includes a prefetch module that performs hardware prefetches from a memory block of the shared memory using the prefetch trait. The hardware data prefetcher also includes an update module that performs analysis of accesses to the memory block by the plurality of memory access agents and, based on the analysis, dynamically updates the prefetch trait to either exclusive or shared while the prefetch module performs hardware prefetches from the memory block using the prefetch trait.

Abstract: A processor includes a processing core that detects a predetermined program is running on the processor and looks up a prefetch trait associated with the predetermined program running on the processor, wherein the prefetch trait is either exclusive or shared. The processor also includes a hardware data prefetcher that performs hardware prefetches for the predetermined program using the prefetch trait. Alternatively, the processing core loads each of one or more range registers of the processor with a respective address range in response to detecting that the predetermined program is running on the processor. Each of the one or more address ranges has an associated prefetch trait, wherein the prefetch trait is either exclusive or shared. The hardware data prefetcher performs hardware prefetches for the predetermined program using the prefetch traits associated with the address ranges loaded into the range registers.

Abstract: A microprocessor includes a plurality of registers that holds an architectural state of the microprocessor and an indicator that indicates a boot instruction set architecture (ISA) of the microprocessor as either the x86 ISA or the Advanced RISC Machines (ARM) ISA. The microprocessor also includes a hardware instruction translator that translates x86 ISA instructions and ARM ISA instructions into microinstructions. The hardware instruction translator translates, as instructions of the boot ISA, the initial ISA instructions that the microprocessor fetches from architectural memory space after receiving a reset signal. The microprocessor also includes an execution pipeline, coupled to the hardware instruction translator. The execution pipeline executes the microinstructions to generate results defined by the x86 ISA and ARM ISA instructions.

Abstract: A microprocessor includes a plurality of processing cores each including a hardware instruction translator that translates instructions of x86 instruction set architecture (ISA) machine language programs and Advanced RISC Machines (ARM) ISA machine language programs into microinstructions defined by a microinstruction set of the microprocessor. The microinstructions are encoded in a distinct manner from the manner in which the instructions of the x86 and ARM instruction sets are defined. Each core includes an execution pipeline that executes the microinstructions to generate results defined by the x86 ISA and ARM ISA instructions. Each core uses and associated indicator to determine whether it will boot as an x86 ISA core or an ARM ISA core when reset. The indicators are configurable to indicate that at least one of the cores will boot as an x86 ISA core and at least one other of the cores will boot as an ARM ISA core.

Abstract: A microprocessor processes conditional non-branch instructions that specify a condition and instruct the microprocessor to perform an operation if the condition is satisfied and otherwise to not perform the operation. A predictor provides a prediction about a conditional non-branch instruction. An instruction translator translates the conditional non-branch instruction into a no-operation microinstruction when the prediction predicts the condition will not be satisfied, and into a set of one or more microinstructions to unconditionally perform the operation when the prediction predicts the condition will be satisfied. An execution pipeline executes the no-operation microinstruction or the set of microinstructions. The predictor translates into a second set of one or more microinstructions to conditionally perform the operation when the prediction does not make a prediction.

Abstract: A microprocessor includes a first and second hardware data prefetchers configured to prefetch data into the microprocessor according to first and second respective algorithms, which are different. The second prefetcher is configured to detect a memory access pattern within a memory region and responsively prefetch data from the memory region according the second algorithm. The second prefetcher is further configured to provide to the first prefetcher a descriptor of the memory region. The first prefetcher is configured to stop prefetching data from the memory region in response to receiving the descriptor of the memory region from the second prefetcher. The second prefetcher also provides to the first prefetcher a communication to resume prefetching data from the memory region, such as when the second prefetcher subsequently detects that a predetermined number of memory accesses to the memory region are not in the memory access pattern.

Abstract: An instruction translator receives a conditional load/store instruction that specifies a condition, destination/data register, base register, offset source, and memory addressing mode. The instruction instructs the microprocessor to load data from a memory location into the destination register (conditional load) or store data to the memory location from the data register (conditional store) only if the condition flags satisfy the condition. The offset source specifies whether the offset is an immediate value or a value in an offset register. The addressing mode specifies whether the base register is updated when the condition flags satisfy the condition. The instruction translator translates the conditional load instruction into a number of microinstructions, which varies as a function of the offset source, addressing mode, and whether the conditional instruction is a conditional load or store instruction.

Abstract: A system includes functional units that are dynamically configurable during operation of the system. The system also includes a first module that collects performance data while the system executes a program with the functional units configured according to a configuration setting. The system also includes a second module that sends information to a server. The information includes the performance data, the configuration setting and data from which the program may be identified. The system also includes a third module that instructs the system to re-configure the functional units with a new configuration setting received from the server while the program is being executed by the system. The new configuration setting is based on analysis by the server of the information sent by the system and of similar information sent by other systems that include the dynamically configurable functional units.

Abstract: A server includes a first module that receives information from a plurality of systems. Each system of the plurality of systems includes functional units that are dynamically configurable during operation of the system. The information from each system of the plurality of systems includes performance data collected while executing a program when the functional units are configured according to a configuration setting respective to the system. The server also includes a second module that analyzes the received information to select a best-performing configuration setting of the configuration settings received from the plurality of systems. The server also includes a third module that provides a new configuration setting to the plurality of systems. The new configuration setting is a modification of the best-performing configuration.

Abstract: A microprocessor supports an instruction set architecture that specifies: processor modes, architectural registers associated with each mode, and a load multiple instruction that instructs the microprocessor to load data from memory into specified ones of the registers. Direct storage holds data associated with a first portion of the registers and is coupled to an execution unit to provide the data thereto. Indirect storage holds data associated with a second portion of the registers and cannot directly provide the data to the execution unit. Which architectural registers are in the first and second portions varies dynamically based upon the current processor mode. If a specified register is currently in the first portion, the microprocessor loads data from memory into the direct storage, whereas if in the second portion, the microprocessor loads data from memory into the direct storage and then stores the data from the direct storage to the indirect storage.

Abstract: A microprocessor includes a translation lookaside buffer and a first request to load into the microprocessor a page table entry in response to a miss of a virtual address in the translation lookaside buffer. The requested page table entry is included in a page table. The page table encompasses a plurality of cache lines including a first cache line that includes the requested page table entry. The microprocessor also includes hardware logic that makes a determination whether a second cache line physically sequential to the first cache line is outside the page table, and a second request to prefetch the second cache line into the microprocessor. The second request is selectively generated based at least on the determination made by the hardware logic.

Abstract: A microprocessor capable of operating as both an x86 ISA and an ARM ISA microprocessor includes first, second, and third storage that stores x86 ISA-specific, ARM ISA-specific, and non-ISA-specific state, respectively. When reset, the microprocessor initializes the first storage to default values specified by the x86 ISA, initializes the second storage to default values specified by the ARM ISA, initializes the third storage to predetermined values, and begins fetching instructions of a first ISA. The first ISA is the x86 ISA or the ARM ISA and a second ISA is the other ISA. The microprocessor updates the third storage in response to the first ISA instructions. In response to a subsequent one of the first ISA instructions that instructs the microprocessor to reset to the second ISA, the microprocessor refrains from modifying the non-ISA-specific state stored in the third storage and begins fetching instructions of the second ISA.

Abstract: A microprocessor capable of running both x86 instruction set architecture (ISA) machine language programs and Advanced RISC Machines (ARM) ISA machine language programs includes a mode indicator that indicates whether the microprocessor is currently fetching instructions of an x86 ISA or ARM ISA machine language program and a plurality of hardware registers. When the mode indicator indicates the microprocessor is currently fetching x86 ISA machine language program instructions, the plurality of hardware registers store x86 ISA architectural state; when the mode indicator indicates the microprocessor is currently fetching ARM ISA machine language program instructions, the plurality of hardware registers store ARM ISA architectural state.

Abstract: An ISA-defined instruction includes an immediate field having a first and second portions specifying first and second values, which instructs the microprocessor to perform an operation using a constant value as one of its source operands. The constant value is the first value rotated/shifted by a number of bits based on the second value. An instruction translator translates the instruction into one or more microinstructions. An execution pipeline executes the microinstructions generated by the instruction translator. The instruction translator, rather than the execution pipeline, generates the constant value for the execution pipeline as a source operand of at least one of the microinstructions for execution by the execution pipeline.

Abstract: A processor includes an indicator configured to indicate a first mode or a second mode and a functional unit configured to perform computations with a full degree of accuracy when the indicator indicates the first mode and to perform computations with less than the full degree of accuracy when the indicator indicates the second mode.

Abstract: A processor includes a storage configured to receive a snapshot of a state of the processor prior to performing a set of computations in an approximating manner. The processor also includes an indicator that indicates an amount of error accumulated while the set of computations is performed in the approximating manner. When the processor detects that the amount of error accumulated has exceeded an error bound, the processor is configured to restore the state of the processor to the snapshot from the storage.