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

4-44 Vol. 2B
INSTRUCTION SET REFERENCE, N-Z
PADDUSB/PADDUSW—Add Packed Unsigned Integers with Unsigned
Saturation
Description
Performs a SIMD add of the packed unsigned integers from the source operand
(second operand) and the destination operand (first operand), and stores the packed
integer results in the destination operand. See Figure 9-4 in the Intel
®
64 and IA-32
Architectures Software Developer’s Manual, Volume 1, for an illustration of a SIMD
operation. Overflow is handled with unsigned saturation, as described in the
following paragraphs.
These instructions can operate on either 64-bit or 128-bit operands. When operating
on 64-bit operands, the destination operand must be an MMX technology register
and the source operand can be either an MMX technology register or a 64-bit
memory location. When operating on 128-bit operands, the destination operand
must be an XMM register and the source operand can be either an XMM register or a
128-bit memory location.
The PADDUSB instruction adds packed unsigned byte integers. When an individual
byte result is beyond the range of an unsigned byte integer (that is, greater than
FFH), the saturated value of FFH is written to the destination operand.
The PADDUSW instruction adds packed unsigned word integers. When an individual
word result is beyond the range of an unsigned word integer (that is, greater than
FFFFH), the saturated value of FFFFH is written to the destination operand.
In 64-bit mode, using a REX prefix in the form of REX.R permits this instruction to
access additional registers (XMM8-XMM15).
Opcode Instruction
64-Bit
Mode
Compat/
Leg Mode Description
0F DC /r PADDUSB mm,
mm/m64
Valid Valid Add packed unsigned byte
integers from mm/m64 and mm
and saturate the results.
66 0F DC /r PADDUSB xmm1,
xmm2/m128
Valid Valid Add packed unsigned byte
integers from xmm2/m128 and
xmm1 saturate the results.
0F DD /r PADDUSW mm,
mm/m64
Valid Valid Add packed unsigned word
integers from mm/m64 and mm
and saturate the results.
66 0F DD /r PADDUSW xmm1,
xmm2/m128
Valid Valid Add packed unsigned word
integers from xmm2/m128 to
xmm1 and saturate the results.