Other

Transmeta Corporation

Nvidia Corporation

Advanced Micro Devices Corporation

Vmware, Inc.

Globalfoundries Inc.

Apple Inc.

Intellectual Ventures Holding 81 LLC

Alexander Klaiber

Guillermo Juan Rozas

David A Dunn

H Peter Anvin

Paul S Serris

John P Banning

James Van Zoeren

Ross Segelken

Lacky V Shah

Darrell D Boggs

Magnus Ekman

Hens Vanderschoot

Brad Hoyt

Sridharan Ramakrishnan

Boris Weissman

Ganesh Venkitachalam

Vyacheslav Vladimirovich Malyugin

Min Xu

Hongwen Gao

Kevin John McGrath

Ben Hertzberg

Michael Shawn Greske

Robert Paul Masleid

Jeffry E Gonion

Geoffrey S Strongin

William Alexander Hughes

Bruce Holmer

Parag Gupta

Eric Hao

Nathan Daniel Tuck

Madhu Swarna

Aravindh Baktha

Rupert Brauch

Thomas Kistler

Nickolas Andrew Fortino

The output of a non-deterministic instruction is handled during record and replay in a virtual machine. An output of a non-deterministic instruction is stored to a buffer during record mode and retrieved from a buffer during replay mode without exiting to the hypervisor. At least part of the contents of the buffer can be stored to a log when the buffer is full during record mode, and the buffer can be replenished from a log when the buffer is empty during replay mode.

Efficient recording and replaying of non-deterministic instructions in a virtual machine and CPU therefor

The disclosure provides a micro-processing system operable in a hardware decoder mode and in a translation mode. In the hardware decoder mode, the hardware decoder receives and decodes non-native ISA instructions into native instructions for execution in a processing pipeline. In the translation mode, native translations of non-native ISA instructions are executed in the processing pipeline without using the hardware decoder. The system includes a code portion profile stored in hardware that changes dynamically in response to use of the hardware decoder to execute portions of non-native ISA code. The code portion profile is then used to dynamically form new native translations executable in the translation mode.

Profiling code portions to generate translations

Embodiments related to managing lazy runahead operations at a microprocessor are disclosed. For example, an embodiment of a method for operating a microprocessor described herein includes identifying a primary condition that triggers an unresolved state of the microprocessor. The example method also includes identifying a forcing condition that compels resolution of the unresolved state. The example method also includes, in response to identification of the forcing condition, causing the microprocessor to enter a runahead mode.

Lazy runahead operation for a microprocessor

Various embodiments of microprocessors and methods of operating a microprocessor during runahead operation are disclosed herein. One example method of operating a microprocessor includes identifying a runahead-triggering event associated with a runahead-triggering instruction and, responsive to identification of the runahead-triggering event, entering runahead operation and inserting the runahead-triggering instruction along with one or more additional instructions in a queue. The example method also includes resuming non-runahead operation of the microprocessor in response to resolution of the runahead-triggering event and re-dispatching the runahead-triggering instruction along with the one or more additional instructions from the queue to the execution logic.

Queued instruction re-dispatch after runahead

Embodiments related to managing potentially invalid results generated/obtained by a microprocessor during runahead are provided. In one example, a method for operating a microprocessor includes causing the microprocessor to enter runahead upon detection of a runahead event. The example method also includes, during runahead, determining that an operation associated with an instruction referencing a storage location would produce a potentially invalid result based on a value of an architectural poison bit associated with the storage location and performing a different operation in response.

Managing potentially invalid results during runahead

A processing bypass directory system and method are disclosed. In one embodiment, a bypass directory tracking process includes setting bits in a bypass directory when a corresponding architectural register is written. The bits are selectively cleared in the bypass directory each cycle. The configuration of the bits is utilized to determine which stage of a bypass path processing information is at.

Processing bypass directory tracking system and method

In a processor, a method for speculative permission acquisition for access to a shared memory. The method includes receiving a store from a processor core to modify a shared cache line, and in response to receiving the store, marking the cache line as speculative. The cache line is then modified in accordance with the store. Upon receiving a modification permission, the modified cache line is subsequently committed.

Speculative permission acquisition for shared memory

A system, method, and computer program product are provided for remapping registers based on a change in execution mode. A sequence of instructions is received for execution by a processor and a change in an execution mode from a first execution mode to a second execution mode within the sequence of instructions is identified, where a first register mapping is associated with the first execution mode and a second register mapping is associated with the second execution mode. Data stored in a set of registers within a processor is reorganized based on the first register mapping and the second register mapping in response to the change in the execution mode.

System, method, and computer program product for remapping registers based on a change in execution mode

Presented systems and methods can facilitate efficient information storage and tracking operations, including translation look aside buffer operations. In one embodiment, the systems and methods effectively allow the caching of invalid entries (with the attendant benefits e.g., regarding power, resource usage, stalls, etc), while maintaining the illusion that the TLBs do not in fact cache invalid entries (e.g., act in compliance with architectural rules). In one exemplary implementation, an 'unreal' TLB entry effectively serves as a hint that the linear address in question currently has no valid mapping. In one exemplary implementation, speculative operations that hit an unreal entry are discarded; architectural operations that hit an unreal entry discard the entry and perform a normal page walk, either obtaining a valid entry, or raising an architectural fault.

Translation lookaside buffer entry systems and methods

In an embodiment, a processor may implement a vector hazard check instruction to detect dependencies between vector memory operations based on the addresses of the vectors accessed by the vector memory operations. The addresses may be specified via a base address and a vector of indexes for each vector. In an embodiment, one of the base addresses may be an implied (or assumed) zero address, reducing the number of operands of the hazard check instruction.

Vector hazard check instruction with reduced source operands

A method for caching attribute data for matching attributes with physical addresses. The method includes storing a plurality of attribute entries in a memory, wherein the memory is configured to provide at least one attribute entry when accessed with a physical address, and wherein the attribute entry provided describes characteristics of the physical address.

Method and system for caching attribute data for matching attributes with physical addresses

A data structure for enforcing consistent per-physical page cacheability attributes is disclosed. The data structure is used with a method for enforcing consistent per-physical page cacheability attributes, which maintains memory coherency within a processor addressing memory, such as by comparing a desired cacheability attribute of a physical page address in a PTE against an authoritative table that indicates the current cacheability status. This comparison can be made at the time the PTE is inserted into a TLB. When the comparison detects a mismatch between the desired cacheability attribute of the page and the page's current cacheability status, corrective action can be taken to transition the page into the desired cacheability state.

Data structure for enforcing consistent per-physical page cacheability attributes

Growing community of inventors

Mountain View, CA, United States of America

Alexander Klaiber