Intel 64 and IA-32 Architectures Software Developers Manual Volume 2B, Instruction Set Reference, N-Z

Vol. 2B B-53
INSTRUCTION FORMATS AND ENCODINGS
B.3 PENTIUM
®
PROCESSOR FAMILY INSTRUCTION
FORMATS AND ENCODINGS
The following table shows formats and encodings introduced by the Pentium
processor family.
Table B-16. Pentium Processor Family Instruction Formats and Encodings,
Non-64-Bit Modes
Instruction and Format Encoding
CMPXCHG8B – Compare and Exchange 8 Bytes
EDX:EAX with memory64 0000 1111 : 1100 0111 : mod 001 r/m
Table B-17. Pentium Processor Family Instruction Formats and Encodings, 64-Bit
Mode
Instruction and Format Encoding
CMPXCHG8B/CMPXCHG16B – Compare and
Exchange Bytes
EDX:EAX with memory64 0000 1111 : 1100 0111 : mod 001 r/m
RDX:RAX with memory128 0100 10XB 0000 1111 : 1100 0111 : mod
001 r/m