AMD x86-64 Architecture Programmer's Manual, Volume 4, 128-Bit ...

26568—Rev. 3.05—September 2003 AMD64 Technology
main memory
Physical memory, such as RAM and ROM (but not cache
memory) that is installed in a particular computer system.
mask
(1) A control bit that prevents the occurrence of a floatingpoint
exception from invoking an exception-handling
routine. (2) A field of bits used for a control purpose.
MBZ
Must be zero. If software attempts to set an MBZ bit to 1, a
general-protection exception (#GP) occurs.
memory
Unless otherwise specified, main memory.
ModRM
A byte following an instruction opcode that specifies
address calculation based on mode (Mod), register (R), and
memory (M) variables.
moffset
A 16, 32, or 64-bit offset that specifies a memory operand
directly without using a ModRM or SIB byte.
msb
Most-significant bit.
MSB
Most-significant byte.
multimedia instructions
A combination of 128-bit media instructions and 64-bit media
instructions.
octword
Same as double quadword.
offset
Same as displacement.
overflow
The condition in which a floating-point number is larger in
magnitude than the largest, finite, positive or negative
Preface xix