摘要:
A method for a byte swap operation on a 64 bit operand. The method of one embodiment comprises accessing an operand stored in a register. The operand is comprised of a plurality of bytes of data. A first set of bytes located in an upper half of said register is reordered. A second set of bytes located in a lower half of said register is reordered. The first set of bytes is swapped with the second set of bytes, wherein the first set of bytes is relocated to the lower half of the register and the second set of bytes is relocated to the upper half of the register.
摘要:
An apparatus and method for efficiently managing the architectural state of a processor. For example, one embodiment of a processor comprises: a source mask register to be logically subdivided into at least a first portion to store a usable portion of a mask value and a second portion to store an indication of whether the usable portion of the mask value has been updated; a control register to store an unusable portion of the mask value; architectural state management logic to read the indication to determine whether the mask value has been updated prior to performing a store operation, wherein if the mask value has been updated, then the architectural state management logic is to read the usable portion of the mask value from the first portion of the source mask register and zero out bits of the unusable portion of the mask value to generate a final mask value to be saved to memory, and wherein if the mask value has not been updated, then the architectural state management logic is to concatenate the usable portion of the mask value with the unusable portion of the mask value read from the control register to generate a final mask value to be saved to memory.