Intel Corporation

Christopher T Weaver

Shubhendu Sekhar Mukherjee

Joel S Emer

Steven Karl Reinhardt

Michael J Smith

Jason W Brandt

Hong Wang

Wei Ey Li

Thomas A Hartin

Guilherme D Ottoni

An apparatus is described having decode circuitry to decode a first instruction, wherein the first instruction indicates that a copy of a plurality of condition codes bits is to be copied from a first register to a second register. The apparatus also has first execution circuitry to copy a plurality of condition code bits from a first register to a second register.

System, apparatus, and method for supporting condition codes

A technique to reduce false error detection in microprocessors. A pi bit is propagated with an instruction through an instruction flow path. When a parity error is detected, the pi bit is set, instead of raising a machine check exception. Upon reaching a commit point, the processor can determine if the instruction was on a wrong path.

Method and apparatus for reducing false error detection in a microprocessor

A technique to reduce false error detection in microprocessors within a redundant multi-threaded computing environment. A pi bit is propagated with at least two instructions through an instruction flow path. Results of executing the instruction are compared to see if an error has occurred and if so, the pi bits are examined to determine which instruction contains the error.

Method and apparatus for reducing false error detection in a redundant multi-threaded system

A multithreaded architecture is disclosed for managing external memory updates for fault detection in redundant multithreading systems using speculative memory support. In particular, a method provides input replication of load values on a SRT processor by using speculative memory support to isolate redundant threads form external updates. This method thus avoids the need for dedicated structures to provide input replication.

Managing external memory updates for fault detection in redundant multithreading systems using speculative memory support

A technique to reduce false error detection in microprocessors by tracking instructions neutral to errors. As an instruction is decoded, an anti-pi bit is tagged to the decoded instruction. When a parity error is detected, an instruction queue first checks if the anti-pi bit is set. If the anti-pi bit is set, then instruction is neutral to errors, and the pi bit need not be set. Prefetch, branch predict hint and NOP are types of instructions that are neutral to errors.

Reducing false error detection in a microprocessor by tracking instructions neutral to errors

A method and apparatus for a checker instruction in a redundant multithreading environment is described. In one embodiment, when RMT requires, a processor may issue a checker instruction in both a leading thread and a trailing thread. The checker instruction may travel down individual pipelines for each thread independently until it reaches a buffer at the end of each pipeline. Then, prior to committing the checker instruction, the checker instruction looks for its counterpart and does a comparison of the instructions. If the checker instructions match, the checker instructions commit and retires otherwise an error is declared.

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Marlboro, MA, United States of America

Christopher T Weaver