Mips Technologies, Inc.

Maria Ukanwa

Karagada Ramarao Kishore

Kjeld Svendsen

Gideon Intrater

Vidya Rajagopalan

Xing Yu Jiang

Xing Xu Jiang

A system implemented in hardware includes a main processing core decoding instructions for out of order execution. The instructions include template based user defined instructions. A user execution block executes the template based user defined instructions. An interface is positioned between the main processing core and the user execution block. A computer readable medium includes executable instructions to describe a processing core supporting execution of a proprietary instruction set and decoding of customized instructions that adhere to a specified pattern. The specified pattern includes a source, a destination and a latency period. A user execution block is connected to the processing core to execute the customized instructions.

Apparatus and method for processing template based user defined instructions

A conditional move instruction implemented in a processor by forming and processing two decoded instructions, and applications thereof. In an embodiment, the conditional move instruction specifies a first source operand, a second source operand, and a third operand that is both a source and a destination. If the value of the second operand is not equal to a specified value, the first decoded instruction moves the third operand to a completion buffer register. If the value of the second operand is equal to the specified value, the second decoded instruction moves the value of the first operand to the completion buffer. When the decoded instruction that performed the move graduates, the contents of the completion buffer register is transferred to a register file register specified by the third operand.

Conditional move instruction formed into one decoded instruction to be graduated and another decoded instruction to be invalidated

A coprocessor interface unit for interfacing a coprocessor to an out-of-order execution pipeline, and applications thereof. In an embodiment, the coprocessor interface unit includes an in-order instruction queue, a coprocessor load data queue, and a coprocessor store data queue. Instructions are written into the in-order instruction queue by an instruction dispatch unit. Instructions exit the in-order instruction queue and enter the coprocessor. In the coprocessor, the instructions operate on data read from the coprocessor load data queue. Data is written back, for example, to memory or a register file by inserting the data into the out-of-order execution pipeline, either directly or via the coprocessor store data queue, which writes back the data.

Coprocessor load data queue for interfacing an out-of-order execution unit with an in-order coprocessor

A processor core and method for managing program counter redirection in an out-of-order processor pipeline. In one embodiment, the pipeline of the processor core includes a front-end instruction fetch portion, a back-end instruction execution portion, and pipeline control logic. Operation of the instruction fetch portion is decoupled from operation of the instruction execution portion. Following detection of a control transfer misprediction, operation of the instruction fetch portion is halted and instructions residing in the instruction fetch portion are invalidated. When the instruction associated with the misprediction reaches a selected pipeline stage, instructions residing in the instruction execution portion of the pipeline are invalidated and the flow of instructions from the instruction fetch portion to the instruction execution portion of the processor pipeline is restarted. A mispredict instruction identification checker and instruction identification tags are used to determine if a control transfer instruction is permitted to redirect instruction fetching.

Processor core and method for managing program counter redirection in an out-of-order processor pipeline

A processor includes a coprocessor interface unit that couples a coprocessor that executes instructions in-program order to an execution unit that executes instructions out-of-program order. The coprocessor interface unit includes a coprocessor store data queue. If data stored in a register of the coprocessor is to be stored in a register file of the execution unit, the data is transferred from the coprocessor to the coprocessor store data queue. A graduation unit coupled to the coprocessor is also provided. The graduation unit provides a signal to the coprocessor that determines whether an instruction executed by the coprocessor is permitted to alter an architectural state of the processor.

Growing community of inventors

Morgan Hill, CA, United States of America

Maria Ukanwa