Intel Corporation

Yuval Bustan

Zeev Sperber

Robert Valentine

Ittai Anati

Sagi Lahav

Rafi Marom

A method and apparatus for a two micro-operation flow using source override. In one embodiment, the method includes the identification of a macro-instruction having one or more streaming single instruction multiple data extension type operands. Once received, the macro-instruction is decoded into a first micro-operation (uOP) and a second uOP. Once decoded, a signal is asserted to disable source operand override logic if the first micro-operation updates a logical destination register that matches a logical source register of the micro-operation. Otherwise, the mutual source override is active and executed by a register alias table (RAT) when uOP with matching logic source and destination register are detected in a same clock cycle. In doing so, macro-instructions having 128-bit operands may be processed using, for example, two uOPs (one for the lower half and one for the upper half) in a 64-bit implementation, while preserving the atomicity of the original instruction.

Apparatus and method for two micro-operation flow using source override

Two or more pointers, each of which indicates where values of a respective group of bits of a source of a particular micro-operation will be found when the particular micro-operation is executed, may not all point to the same register. Renaming of the source of the particular micro-operation may be enabled by generating one or more new micro-operations that merge the values into a single register. The one or more new micro-operations are inserted into a sequence of micro-operations that includes the particular micro-operation. Once the source of the particular micro-operation has been renamed, subsequent micro-operations in the sequence may be renamed, if appropriate, and executed, without having to wait for the values to be calculated.

Elimination of potential renaming stalls due to use of partial registers

In some embodiments of the present invention, one or more elements of a processor core may receive a signal indicating that operands of a micro-instruction are narrow, for example less than or equal to 32 bits. In response to this signal, one or more components of a processor core element that are able to handle more than 32 bits of data (e.g. operands or results) may function as though they handle only 32 bits of data.

Growing community of inventors

Mishmeret, Israel

Yuval Bustan