CMPXCHG8B
SEMAPHORE PENTIUMREAL x86_64
2 encoding forms.
X86_CMPXCHG8B_X86_LEGACY_0F_C7_298793
m64,
XED_CMPXCHG8B_X86_LEGACY_0F_C7_485727
MEM0:rcw:q REG0=XED_REG_EDX:rcw:SUPP REG1=XED_REG_EAX:rcw:SUPP REG2=XED_REG_ECX:r:SUPP REG3=XED_REG_EBX:r:SUPP MEM0:rcw:q REG0=XED_REG_EDX:rcw:SUPP REG1=XED_REG_EAX:rcw:SUPP REG2=XED_REG_ECX:r:SUPP REG3=XED_REG_EBX:r:SUPP