MMX instruction that compares 2
64 bit values for
equality,
dwordwise.
Note: unlike integer comparison operators, MMX comparison operators do not affect any
flags.
Each
dword of the destination register is set to
all 1's if it was equal to the
corresponding word of the source register. Otherwise, it is set to all zeros.
Comparing a register with itself will always produce all 1's.
See also:
PCMPGTD,
PCMPEQB,
PCMPEQW