Method and apparatus for performing a shift and exclusive or operation in a single instruction

A system comprising:

• a display control;
• a memory interface;
• and
• a processor, the processor comprising:
• a plurality of levels of cache including a Level 1 (L1) cache;
• a plurality of integer registers;
• a plurality of floating-point registers in which to store floating-point data elements including 128-bit packed double operands that are to have two 64-bit double floating-point data elements;
• a plurality of status registers;
• an instruction pointer register;
• an instruction prefetcher to fetch instructions;
• a decoder to decode the fetched instructions including an instruction to perform a shift and exclusive OR (XOR) operation, wherein the instruction to perform the shift and XOR operation has a first source operand identifier to identify a first source operand, a second source operand identifier to identify a second source operand, an immediate field to specify a shift amount, and a field to identify the first and second source operands as being one of a 32-bit source operand and a 64-bit source operand;
• and
• an execution unit coupled to the decoder, such that the processor, in response to the instruction to perform the shift and XOR operation, is to:
• shift the first source operand by the shift amount specified by the immediate field, wherein the first source operand is a scalar value,
• XOR the shifted first source operand with the second source operand, and
• store a resulting shifted and XOR'ed value in a destination register, wherein the destination register is a scalar register;
• and
• a floating-point unit to operate on floating-point data elements.