Abstract: Retiring instructions out-of-order includes: receiving processor instructions comprising two or more and fewer than all processor instructions generated based on a program, where the processor instructions include a first instruction and a second instruction such that the first instruction precedes the second instruction in a program order of the program; receiving a start instruction that immediately precedes the processor instructions and indicates that the processor instructions are to be retired out-of-order; receiving a stop instruction immediately that succeeds the processor instructions and indicates a stop to out-of-order instruction retirement; and, in response to completing execution of the second instruction before completing execution of the first instruction, retiring the second instruction before retiring the first instruction.

Abstract: A pipeline in a processor core includes: at least one stage that decodes instructions including load instructions that retrieve data stored at respective virtual addresses, at least one stage that issues at least some decoded load instructions out-of-order, and at least one stage that initiates at least one prefetch operation. Copies of page table entries mapping virtual addresses to physical addresses are stored in a TLB. Managing misses in the TLB includes: handling a load instruction issued out-of-order using a hardware page table walker, after a miss in the TLB, handling a prefetch operation using the hardware page table walker, after a miss in the TLB, and handling any software-calling faults triggered by out-of-order load instructions handled by the hardware page table walker differently from any software-calling faults triggered by prefetch operations handled by the hardware page table walker.

Abstract: Memory prefetching in a processor comprises: identifying, in response to memory access instructions, a pattern of addresses; and determining, based on the pattern of addresses, an address to prefetch. Determining the address to prefetch comprises: determining, using the pattern of addresses, an index into a history table; retrieving, from the history table and using the index, an offset value, wherein the offset value is not the address to prefetch; and determining the address to prefetch using the offset value and at least one address of the pattern of addresses. The method further comprises prefetching the address to prefetch.

Abstract: Described herein are systems and methods for dynamic designation of instructions as sensitive. For example, some methods include detecting that a first instruction of a first process has been designated as a sensitive instruction; checking whether a sensitive handling enable indicator in a process state register storing a state of the first process is enabled; responsive to detection of the sensitive instruction and enablement of the sensitive handling enable indicator, invoking a constraint for execution of the first instruction; executing the first instruction subject to the constraint; and executing a second instruction of the first process without the constraint.

Abstract: Described herein are systems and methods for secure multithread execution. For example, some methods include fetching an instruction of a first thread from a memory into a processor pipeline that is configured to execute instructions from two or more threads in parallel using execution units of the processor pipeline; detecting that the instruction has been designated as a sensitive instruction; responsive to detection of the sensitive instruction, disabling execution of instructions of threads other than the first thread in the processor pipeline during execution of the sensitive instruction by an execution unit of the processor pipeline; executing the sensitive instruction using an execution unit of the processor pipeline; and, responsive to completion of execution of the sensitive instruction, enabling execution of instructions of threads other than the first thread in the processor pipeline.

Abstract: Controlling a vehicle comprises: providing, from an activation port, an activation signal for activating control of at least one of one or more electronically controllable devices during a high-speed activation time interval; and managing power consumed by an integrated circuit that includes two or more processor cores during the high-speed activation time interval. The managing includes: receiving the activation signal from the activation port, in response to the activation signal, executing at least a portion of stored code by a first subset of fewer than all of the processor cores at a first power level, and after the high-speed activation time interval, executing at least a portion of the stored code by a second subset of one or more of the processor cores at a second power level lower than the first power level.

Abstract: In a pipeline configured for out-of-order issuing, handling translation of virtual addresses to physical addresses includes: storing translations in a translation lookaside buffer (TLB), and updating at least one entry in the TLB based at least in part on an external instruction received from outside a first processor core. Managing external instructions includes: updating issue status information for each of multiple instructions stored in an instruction queue, processing the issue status information in response to receiving a first external instruction to identify at least two instructions in the instruction queue, including a first queued instruction and a second queued instruction. An instruction for performing an operation associated with the first external instruction is inserted into a stage of the pipeline so that the operation associated with the first external instruction is committed before the first queued instruction is committed and after the second queued instruction is committed.

Abstract: A front-end portion of a pipeline includes a stage that speculatively issues at least some instructions out-of-order. A back-end portion of the pipeline includes one or more stages that access a processor memory system. In the front-end (back-end), execution of instructions is managed based on information available in the front-end (back-end). Managing execution of a first memory barrier instruction includes preventing speculative out-of-order issuance of store instructions. The back-end control circuitry provides information accessible to the front-end control circuitry indicating that one or more particular memory instructions have completed handling by the processor memory system.

Abstract: A first cache module, comprising fully associative cache circuitry, provides TLB entries for a first group of multiple page sizes. A second cache module, comprising set associative cache circuitry, provides TLB entries for a second group of multiple page sizes. Managing TLB entries includes: performing a search in the first cache module based on selected tag bits of a target virtual address that are selected for each TLB entry in the first cache module based on information stored in the first cache module corresponding to one of the multiple pages sizes in the first group, and performing multiple search iterations in the second cache module based on selected index bits and selected tag bits of the target virtual address, where quantities of bits in the selected index bits and the selected tag bits are different for each of the search iterations.

Abstract: In a pipeline configured for out-of-order issuing, handling translation of virtual addresses to physical addresses includes: storing translations in a translation lookaside buffer (TLB), and updating at least one entry in the TLB based at least in part on an external instruction received from outside a first processor core. Managing external instructions includes: updating issue status information for each of multiple instructions stored in an instruction queue, processing the issue status information in response to receiving a first external instruction to identify at least two instructions in the instruction queue, including a first queued instruction and a second queued instruction. An instruction for performing an operation associated with the first external instruction is inserted into a stage of the pipeline so that the operation associated with the first external instruction is committed before the first queued instruction is committed and after the second queued instruction is committed.

Abstract: A method for managing an observed order of instructions in a computing system includes utilizing an overloaded memory barrier instruction to specify whether a global ordering constraint or a local ordering constraint is enforced.

Abstract: At least some instructions executed in a pipeline are each associated with corresponding trace information that characterizes execution of that instruction in the pipeline. A predetermined type of store instructions flow through a subset of contiguous stages of the pipeline. A signal is received to store a portion of the trace information. A stage before the subset of contiguous stages is stalled. A store instruction of the predetermined type is inserted into a stage at the beginning of the subset of contiguous stages to enable the store instruction to reach the memory access stage at which an operand of the store instruction including the portion of the trace information is sent out of the pipeline. The store instruction is filtered from a stage of the subset of contiguous stages that occurs earlier in the pipeline than a stage in which trace information is generated.

Abstract: Instructions are executed in a pipeline. Storage accessible to the pipeline stores branch prediction information characterizing results of branch instructions previously executed. A predicted branch result is provided, for at least some branch instructions, based on a selected predictor of multiple predictors. An actual branch result is provided based on an executed branch instruction, and the branch prediction information is updated based on the actual branch result. The predictors include: a first predictor that determines the predicted branch result based on at least a portion of the branch prediction information; and a second predictor that determines the predicted branch result independently from the branch prediction information.

Abstract: At least some instructions executed in a pipeline are each associated with corresponding trace information that characterizes execution of that instruction in the pipeline. A predetermined type of store instructions flow through a subset of contiguous stages of the pipeline. A signal is received to store a portion of the trace information. A stage before the subset of contiguous stages is stalled. A store instruction of the predetermined type is inserted into a stage at the beginning of the subset of contiguous stages to enable the store instruction to reach the memory access stage at which an operand of the store instruction including the portion of the trace information is sent out of the pipeline. The store instruction is filtered from a stage of the subset of contiguous stages that occurs earlier in the pipeline than a stage in which trace information is generated.

Abstract: A first cache module, comprising fully associative cache circuitry, provides TLB entries for a first group of multiple page sizes. A second cache module, comprising set associative cache circuitry, provides TLB entries for a second group of multiple page sizes. Managing TLB entries includes: performing a search in the first cache module based on selected tag bits of a target virtual address that are selected for each TLB entry in the first cache module based on information stored in the first cache module corresponding to one of the multiple pages sizes in the first group, and performing multiple search iterations in the second cache module based on selected index bits and selected tag bits of the target virtual address, where quantities of bits in the selected index bits and the selected tag bits are different for each of the search iterations.

Abstract: In a pipeline configured for out-of-order issuing, handling translation of virtual addresses to physical addresses includes: storing translations in a translation lookaside buffer (TLB), and updating at least one entry in the TLB based at least in part on an external instruction received from outside a first processor core. Managing external instructions includes: updating issue status information for each of multiple instructions stored in an instruction queue, processing the issue status information in response to receiving a first external instruction to identify at least two instructions in the instruction queue, including a first queued instruction and a second queued instruction. An instruction for performing an operation associated with the first external instruction is inserted into a stage of the pipeline so that the operation associated with the first external instruction is committed before the first queued instruction is committed and after the second queued instruction is committed.

Abstract: Managing the messages associated with memory pages stored in a main memory includes: receiving a message from outside the pipeline, and providing at least one low-level instruction to the pipeline for performing an operation indicated by the received message. Executing instructions in the pipeline includes: executing a series of low-level instructions in the pipeline, where the series of low-level instructions includes a first (second) set of low-level instructions converted from a first (second) high-level instruction.

Abstract: A predicted branch result is determined based on at least a portion of branch prediction information, which is updated based on an actual branch result, which is provided based on an executed branch instruction. For a first execution of a first branch instruction, the updating includes: computing a randomized value and storing the randomized value in association with an identified subset of one or more contexts that includes a context associated with the first branch instruction, obfuscating the actual branch result based at least in part on the randomized value, and storing a resulting obfuscated value in the branch prediction information. Providing a predicted branch result for a second execution of the first branch instruction includes: retrieving the obfuscated value from the branch prediction information, retrieving the randomized value, and de-obfuscating the obfuscated value using the randomized value to recover the actual branch result as the predicted branch result.

Abstract: Managing memory access requests for a plurality of processor cores includes: storing admission control information for determining whether or not to admit a predetermined type of memory access request into a shared resource that is shared among the processor cores and includes one or more cache levels of a hierarchical cache system and at least one memory controller for accessing a main memory; determining whether or not a memory access request of the predetermined type made on behalf of a first processor core should be admitted into the shared resource based at least in part on the stored admission control information; and updating the admission control information based on a latency of a response to a particular memory access request admitted into the shared resource, where the updating depends on whether the response originated from a particular cache level included in the shared resource or from the main memory.

Abstract: Managing instructions on a processor includes: identifying selected instructions as being associated with operations from a stored library of operations. The identifying includes, for instructions included in a particular thread executing on the processor, identifying first/second subsets of the instructions as being associated with a lock/unlock operation based on predetermined characteristics of the instructions. Managing lock/unlock operations associated with the selected instructions that are issued on a first processor core includes, for each instruction included in a first thread and identified as being associated with a lock operation corresponding to a particular lock, in response to determining that the particular lock has already been acquired, continuing to attempt to acquire the particular lock for multiple attempts using a lock operation different from the lock operation in the stored library.