Abstract: Obsoleting values stored in registers in a processor based on processing obsolescent register-encoded instructions is disclosed. The processor is configured to support execution of read and/or write instructions that include obsolescence encoding indicating that one or more of its source and/or target register operands are to be obsoleted by the processor. A register encoded as obsolescent means the data value stored in such register will not be used by subsequent instructions in an instruction stream, and thus does not need to be retained. Thus, such register can be set as being in an obsolescent state so that the data value stored in such register can be ignored to improve performance. As one example, data values for registers having an obsolescent state can be ignored and thus not stored in a saved context for a process being switched out, thus conserving memory and improving processing time for a process switch.

Abstract: Obsoleting values stored in registers in a processor based on processing obsolescent register-encoded instructions is disclosed. The processor is configured to support execution of read and/or write instructions that include obsolescence encoding indicating that one or more of its source and/or target register operands are to be obsoleted by the processor. A register encoded as obsolescent means the data value stored in such register will not be used by subsequent instructions in an instruction stream, and thus does not need to be retained. Thus, such register can be set as being in an obsolescent state so that the data value stored in such register can be ignored to improve performance. As one example, data values for registers having an obsolescent state can be ignored and thus not stored in a saved context for a process being switched out, thus conserving memory and improving processing time for a process switch.

Abstract: Providing exception stack management using stack panic fault exceptions in processor-based devices is disclosed. In this regard, a processor device defines a “stack panic fault exception” that may be raised upon execution of an exception handler store operation attempting to write state data into an exception stack, and provides a dedicated plurality of stack panic fault exception state registers in which stack panic fault exception state data may be saved. Upon detecting a first exception, the processor device transfers program control to an exception handler for the first exception. If a second exception occurs upon execution of a store operation in the exception handler, the processor device determines that the second exception should be handled as a stack panic fault exception, saves the stack panic fault exception state data in the stack panic fault exception state registers, and transfers program control to a stack panic fault exception handler.

Abstract: Providing express memory obsolescence in processor-based devices is disclosed. In this regard, an instruction set architecture (ISA) of a processor-based device provides a memory load instruction indicating a final memory load operation from a memory address (i.e., after the memory load operation represented by the memory load instruction is performed, the value at the memory address need not be maintained). Upon receiving the memory load instruction by an execution pipeline of the processor-based device, an entry corresponding to the memory address of the memory load instruction is located in an intermediate memory external to the system memory of the processor-based device, and used to perform the final memory load operation. After the final memory load operation is performed using the entry, a value of an obsolete indicator for the entry is set to indicate that the entry can be reused prior to its contents being written to the system memory.

Abstract: A method includes reading, by a processor, one or more configuration values from a storage device or a memory management unit. The method also includes loading the one or more configuration values into one or more registers of the processor. The one or more registers are useable by the processor to perform address translation.

Abstract: Delays due to waiting for operands that will not be used by a select operand instruction, are alleviated based on an early recognition that such operand data is not required in order to complete the processing of the select operand instruction. At appropriate points prior to execution, determinations are made regarding a selection criterion or criteria specified by the select operand instruction, conditions that affect the selection criteria, and the availability of operands. A hold circuit uses the determinations to control the activation and release of a hold signal that controls processor pipeline stalls. A stall required to wait for operand data is skipped or a stall is terminated early, if the selected operand is available even though the other operand, that will not be used, is not available. A stall due to waiting for operands is maintained until the selection criteria is met and the selected operand is fetched and made available.

Abstract: An apparatus includes a primary hypervisor that is executable on a first set of processors and a secondary hypervisor that is executable on a second set of processors. The primary hypervisor may define settings of a resource and the secondary hypervisor may use the resource based on the settings defined by the primary hypervisor. For example, the primary hypervisor may program memory address translation mappings for the secondary hypervisor. The primary hypervisor and the secondary hypervisor may include their own schedulers.

Abstract: A memory structure compresses a portion of a memory tag using an indexed tag compression structure. A set of higher order bits of the memory tag may be stored in the indexed tag compression structure, where the set of higher order bits are identified by an index value. A tag array stores a set of lower order bits of the memory tag and the index value identifying the entry in the tag compression structure storing the set of higher order bits of the memory tag. The memory tag may comprise at least a portion of a memory address of a data element stored in a data array.

Abstract: A method and apparatus for allowing an out-of-order processor to reuse an in-use physical register is disclosed herein. The method and apparatus uses identifiers, such as tokens and/or other identifiers in a rename map table (RMT) and a physical register file (PRF), to indicate whether an instruction result is allowed or disallowed to be written into a physical register.

Abstract: A device includes a memory that stores a first page table that includes a first page table entry, wherein the first page table entry further includes a physical address, an alternative location associated with the page table entry, and a physical page of memory associated with the physical address. A first processing unit is configured to: read the first page table entry, and determine the physical address from the first page table entry. The second processing unit is configured to: read the physical address from the first page table entry, determine second page attribute data from the alternative location, wherein the second page attribute data define one or more accessibility attributes of the physical page of memory for the second processing unit, and access the physical page of memory associated with the physical address according to the one or more accessibility attributes.

Abstract: Techniques are described for a multi-processor having two or more processors that increases the opportunity for a load-exclusive command to take a cache line in an Exclusive state, which results in increased performance when a store-exclusive is executed. A new bus operation read prefer exclusive is used as a hint to other caches that a requesting master is likely to store to the cache line, and, if possible, the other cache should give the line up. In most cases, this will result in the other master giving the line up and the requesting master taking the line Exclusive. In most cases, two or more processors are not performing a semaphore management sequence to the same address at the same time. Thus, a requesting master's load-exclusive is able to take a cache line in the Exclusive state an increased number of times.

Abstract: Systems and method for memory management units (MMUs) configured to automatically pre-fill a translation lookaside buffer (TLB) with address translation entries expected to be used in the future, thereby reducing TLB miss rate and improving performance. The TLB may be pre-filled with translation entries, wherein addresses corresponding to the pre-fill may be selected based on predictions. Predictions may be derived from external devices, or based on stride values, wherein the stride values may be a predetermined constant or dynamically altered based on access patterns. Pre-filling the TLB may effectively remove latency involved in determining address translations for TLB misses from the critical path.

Abstract: A wireless mobile device includes a graphic processing unit (GPU) that has a system memory management unit (MMU) for saving and restoring system MMU translation contexts. The system MMU is coupled to a memory and the GPU. The system MMU includes a set of hardware resources. The hardware resources may be context banks, with each of the context banks having a set of hardware registers. The system MMU also includes a hardware controller that is configured to restore a hardware resource associated with an access stream of content issued by an execution thread of the GPU. The associated hardware resource may be restored from the memory into a physical hardware resource when the hardware resource associated with the access stream of content is not stored within one of the hardware resources.

Abstract: The disclosure is directed to a weakly-ordered processing system and method for enforcing strongly-ordered memory access requests in a weakly-ordered processing system. The processing system includes a plurality of memory devices and a plurality of processors. Each of the processors are configured to generate memory access requests to one or more of the memory devices, with each of the memory access requests having an attribute that can be asserted to indicate a strongly-ordered request. The processing system further includes a bus interconnect configured to interface the processors to the memory devices, the bus interconnect being further configured to enforce ordering constraints on the memory access requests based on the attributes.

Abstract: A system is disclosed for mapping operating-system-identified addresses for substantially-identical hardware modules into performance-parameter-based addresses for the hardware modules. The mapping is accomplished by configuring a flexible I/O interface responsive to a characterization of at least one performance parameter for each hardware module.

Abstract: A system is disclosed for mapping operating-system-identified addresses for substantially-identical hardware modules into performance-parameter-based addresses for the hardware modules. The mapping is accomplished by configuring a flexible I/O interface responsive to a characterization of at least one performance parameter for each hardware module.

Abstract: An apparatus for emulating the branch prediction behavior of an explicit subroutine call is disclosed. The apparatus includes a first input which is configured to receive an instruction address and a second input. The second input is configured to receive predecode information which describes the instruction address as being related to an implicit subroutine call to a subroutine. In response to the predecode information, the apparatus also includes an adder configured to add a constant to the instruction address defining a return address, causing the return address to be stored to an explicit subroutine resource, thus, facilitating subsequent branch prediction of a return call instruction.

Abstract: A first processing unit and a second processing unit can access a system memory that stores a common page table that is common to the first processing unit and the second processing unit. The common page table can store virtual memory addresses to physical memory addresses mapping for memory chunks accessed by a job of an application. A page entry, within the common page table, can include a first set of attribute bits that defines accessibility of the memory chunk by the first processing unit, a second set of attribute bits that defines accessibility of the same memory chunk by the second processing unit, and physical address bits that define a physical address of the memory chunk.

Abstract: Configuring a surrogate memory accessing agent using an instruction for translating and storing a data value is described. In one embodiment, the instruction is received that includes a first operand specifying a data value to be translated and a second operand specifying a virtual address associated with a location of a surrogate memory accessing agent register in which to store the data value. The data value can be translated to a first physical address. The virtual address can be translated to a second physical address. The first physical address is stored in the surrogate memory accessing agent register based on the second physical address.

Abstract: A device includes a memory that stores a first page table that includes a first page table entry, wherein the first page table entry further includes a physical address, an alternative location associated with the page table entry, and a physical page of memory associated with the physical address. A first processing unit is configured to: read the first page table entry, and determine the physical address from the first page table entry. The second processing unit is configured to: read the physical address from the first page table entry, determine second page attribute data from the alternative location, wherein the second page attribute data define one or more accessibility attributes of the physical page of memory for the second processing unit, and access the physical page of memory associated with the physical address according to the one or more accessibility attributes.