Blakely, Sokoloff, Taylor & Zafman LLP
Instruction set extension using prefixes
 The present invention discloses a method and apparatus for encoding an instruction in an instruction set which uses a prefix code to qualify an existing opcode of an existing instruction. An opcode and an escape code are selected. The escape code is selected such that it is different from the prefix code and the existing opcode. The opcode, the escape code, and the prefix code are combined to generate an instruction code which uniquely represents the operation performed by the instruction. 
Intel Corporation
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G06F G06F
inventional inventional
Shreekant S. Thomas Lance Srinivas Patrice L.
Thakkar Huff Hacking Chennupaty Roussel