User Guide

64-Bit Media Programming 207
24592—Rev. 3.15—November 2009 AMD64 Technology
generated. If all source operands are normalized numbers, these instructions never produce infinities,
NaNs, or denormalized numbers as results.
This aspect of 64-bit media floating-point operations does not comply with the IEEE 754 standard.
Software must use only normalized operands and ensure that computations remain within valid
normalized-number ranges.
No Support for Floating-Point Exceptions. The 64-bit media floating-point instructions do not
generate floating-point exceptions. Software must ensure that in-range operands are provided to these
instructions.
5.6 Instruction Summary—Integer Instructions
This section summarizes the functions of the integer (MMX and a few SSE and SSE2) instructions in
the 64-bit media instruction subset. These include integer instructions that use an MMX register for
source or destination and data-conversion instructions that convert from integers to floating-point
formats. For a summary of the floating-point instructions in the 64-bit media instruction subset,
including data-conversion instructions that convert from floating-point to integer formats, see
“Instruction Summary—Floating-Point Instructions” on page 223.
The instructions are organized here by functional group—such as data-transfer, vector arithmetic, and
so on. Software running at any privilege level can use any of these instructions, if the CPUID
instruction reports support for the instructions (see “Feature Detection” on page 229). More detail on
individual instructions is given in the alphabetically organized “64-Bit Media Instruction Reference”
in Volume 5.
5.6.1 Syntax
Each instruction has a mnemonic syntax used by assemblers to specify the operation and the operands
to be used for source and destination (result) data. The majority of 64-bit media integer instructions
have the following syntax:
MNEMONIC mmx1, mmx2/mem64
Figure 5-10 on page 208 shows an example of the mnemonic syntax for a packed add bytes (PADDB)
instruction.