Intel Corporation

Micron Technology Incorporated

Sae Magnetics (h.k.) Limited

Adi Yoaz

Ronny Ronen

Lihu Rappoport

Zeev Sperber

Mattan Erez

Stephan Jourdan

Sreenivas Subramoney

Jayesh Gaur

Adarsh Chauhan

Stanislav Shwartsman

Franck Sala

Stephan J Jourdan

Michael Bekerman

Bob Valentine

Robert Valentine

Hong Wang

Rajesh Bhikhubhai Patel

Gregory Pribush

Freddy Gabbay

Ilan Y Spillinger

Gad Shlomo Sheaffer

David J Sager

Michael Mishaeli

Shlomo Raikin

Robert S Chappell

Ronak Singhal

George Elias

Ofer Levy

Opher D Kahn

James David Dundas

Lev Makovsky

Gershon Kedem

Evgeni Krimer

Kamil Garifullin

Sangwook Kim

Sumeet Bandishte

Stephen J Jourdan

Pooja Roy

Alexandr Titov

Ori Lempel

Dhananjay Adhikari

Freddy Gabby

Stephen J Jourday

Omer Golz

A processor comprises a microarchitectural feature and dynamic tuning unit (DTU) circuitry. The processor executes a program for first and second execution windows with the microarchitectural feature disabled and enabled, respectively. The DTU circuitry automatically determines whether the processor achieved worse performance in the second execution window. In response to determining that the processor achieved worse performance in the second execution window, the DTU circuitry updates a usefulness state for a selected address of the program to denote worse performance. In response to multiple consecutive determinations that the processor achieved worse performance with the microarchitectural feature enabled, the DTU circuitry automatically updates the usefulness state to denote a confirmed bad state. In response to the usefulness state denoting the confirmed bad state, the DTU circuitry automatically disables the microarchitectural feature for the selected address for execution windows after the second execution window. Other embodiments are described and claimed.

Technology for dynamically tuning processor features

Systems, methods, and apparatuses relating to hardware for auto-predication of critical branches. In one embodiment, a processor core includes a decoder to decode instructions into decoded instructions, an execution unit to execute the decoded instructions, a branch predictor circuit to predict a future outcome of a branch instruction, and a branch predication manager circuit to disable use of the predicted future outcome for a conditional critical branch comprising the branch instruction.

Detecting a dynamic control flow re-convergence point for conditional branches in hardware

A processing device includes a branch IP table and branch predication circuitry coupled to the branch IP table. The branch predication circuitry to: determine a dynamic convergence point in a conditional branch of set of instructions; store the dynamic convergence point in the branch IP table; fetch a first and second speculative path of the conditional branch; while determining which of the first speculative path and the second speculative path is a taken path of the conditional branch and determining whether a dynamic convergence point is fetched corresponding to the stored dynamic convergence point, stall scheduling of instructions of the first speculative path and the second speculative path; and in response to determining that one of the first speculative path and the second speculative path is the taken path and the fetched dynamic convergence point corresponds to the stored convergence point, resume scheduling of the instructions of the taken path.

Automatic predication of hard-to-predict convergent branches

A processor including an execution unit, an instruction scheduler circuit to identify a first instruction of an instruction stream, identify a second instruction on which execution of the first instruction depends, and assign a first dispatch priority value to the first instruction and the second instruction, and a dispatch circuit to dispatch, based on the first dispatch priority value, the first instruction and the second instruction to an instruction execution circuit.

Criticality based port scheduling

A processor of an aspect includes a decode unit to decode a thread pause instruction from a first thread. A back-end portion of the processor is coupled with the decode unit. The back-end portion of the processor, in response to the thread pause instruction, is to pause processing of subsequent instructions of the first thread for execution. The subsequent instructions occur after the thread pause instruction in program order. The back-end portion, in response to the thread pause instruction, is also to keep at least a majority of the back-end portion of the processor, empty of instructions of the first thread, except for the thread pause instruction, for a predetermined period of time. The majority may include a plurality of execution units and an instruction queue unit.

Thread pause processors, methods, systems, and instructions

Methods and apparatus for restoring a meta predictor system upon detecting a branch or binary misprediction, are disclosed. An example apparatus may include a base misprediction history register to store a set of misprediction history values each indicating whether a previous branch prediction taken by a previous branch instruction was predicted correctly or incorrectly. The apparatus may comprise a meta predictor to detect a branch misprediction of a current branch prediction based at least in part on an output of the base misprediction history register. The meta predictor may restore the base misprediction history register based on the detecting of the branch misprediction. Additional apparatus, systems, and methods are disclosed.

Meta predictor restoration upon detecting misprediction

Methods and apparatus relating to a hardware move elimination and/or next page prefetching are described. In some embodiments, a logic may provide hardware move eliminations based on stored data. In an embodiment, a next page prefetcher is disclosed. Other embodiments are also described and claimed.

Tracking mechanism coupled to retirement in reorder buffer for indicating sharing logical registers of physical register in record indexed by logical register

A branch predicting apparatus is disclosed that reduces branch mispredictions in a processor. The branch prediction apparatus includes a base misprediction history register. The branch prediction apparatus includes a meta predictor that receives an index value and a branch prediction to generate a misprediction value in accordance with the base misprediction history register. The branch prediction apparatus also includes a logic gate that receives the branch prediction and the misprediction value to generate a final prediction. The final prediction may be used to predict whether a branch is taken or not taken.

Method and apparatus for predicting branches using a meta predictor

A new class traces for a processing engine, called 'extended blocks,' possess an architecture that permits possible many entry points but only a single exit point. These extended blocks may be indexed based upon the address of the last instruction therein. Use of the new trace architecture provides several advantages, including reduction of instruction redundancies, dynamic block extension and a sharing of instructions among various extended blocks.

Trace indexing via trace end addresses

A method and apparatus for dual-target register allocation is described, intended to enable the efficient mapping/renaming of registers associated with instructions within a pipelined microprocessor architecture.

Method and apparatus for increasing load bandwidth

A memory cache bank prediction unit is provided for use in a processor having a plurality of memory cache banks. The memory cache bank prediction unit has an input port that receives an instruction. The memory cache bank prediction unit also has an evaluation unit, coupled to the input port, that predicts which of the plurality of memory cache banks is associated with the instruction.

Memory cache bank prediction

The present invention is directed to an apparatus and method for data collapsing based on control-flow speculation (conditional branch predictions). Because conditional branch outcomes are resolved based on actual data values, the conditional branch prediction provides potentially valuable insight into data values. Upon encountering a branch if equal instruction and this instruction is predicted as taken or a branch if not equal instruction and this instruction is predicted as not taken, this invention assumes that the two operands used to determine the conditional branch are equal. The data predictions are safe because a data misprediction means a conditional branch misprediction which results in a pipeline flush of the instructions following the conditional branch instruction including the data mispredictions.

Method and system for safe data dependency collapsing based on control-flow speculation

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Austin, TX, United States of America

Adi Yoaz