Intel Corporation

William C Alexander, Iii

Andrew F Glew

Shreekant S Thakkar

Stephen Anthony Fischer

Bryant E Bigbee

Patrice L Roussel

Kris G Konigsfeld

Thomas R Huff

Jeffrey M Abramson

Atiq A Bajwa

Warren R Morrow

The present invention discloses a method and apparatus for saving and restoring registers. A single instruction is decoded. The single instruction moves contents of a plurality of registers associated with a functional unit in a processor to a memory; the processor operates under a plurality of operational modes and operand sizes. The single instruction arranges the contents in the memory according to a predetermined format into a plurality of groups, each group is aligned at an address boundary which corresponds to a multiple of 2bytes. The predetermined format is constant for the plurality of operational modes and operand sizes. The single instruction retains the contents of the plurality of registers after moving.

Efficient saving and restoring state in task switching

A method is provided for recovering the effective address of memory instructions in an out-of-order microprocessor for use by an exception handler upon the occurrence of one of an exception and a systems management interrupt. The microprocessor comprises at least one execution unit for executing a plurality of instructions out-of-order and a re-order buffer having storage locations for buffering result data produced from the execution of the plurality of instructions. Each instruction is associated with a location designator to identify a unique storage location within the re-order buffer in which the result data for an executed instruction is written. The microprocessor further comprises a memory order buffer having storage locations for buffering memory instructions waiting for access to memory for execution, these storage locations also being identified by corresponding location designators. According to this embodiment of the microprocessor, the effective address of memory instructions can be reconstructed by utilizing the location designators of the ROB (Reorder Buffer) to find the corresponding storage location in the MOB (Memory Order Buffer) at which place the linear address for the instruction may be found. By associating both the retirement and exception information of the memory instructions stored within the storage locations of the re-order buffer with the corresponding memory instructions and information stored within the memory order buffer, the linear address of either the youngest, valid, retiring memory uop or the oldest, valid, excepted memory uop can be selected, written to memory and subsequently used to reconstruct the effective address of the memory instruction for use by an exception handler.

Method and apparatus for saving the effective address of floating point

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Portland, OR, United States of America

William C Alexander, Iii