Intel ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS MANUAL VOLUME 1 REV 2.3 Manual page 1718

PADDUSB/PADDUSW—Packed Add Unsigned with Saturation
Opcode
0F DC /r
0F DD /r
Description
Adds the individual unsigned data elements (bytes or words) of the packed source
operand (second operand) to the individual unsigned data elements of the packed
destination operand (first operand). (See
addition exceeds the range for the specified unsigned data type, the result is saturated.
The destination operand must be an MMX technology register; the source operand can
be either an MMX technology register or a quadword memory location.
Figure 3-7.
mm
mm/m64
mm
The PADDUSB instruction adds the unsigned bytes of the source operand to the
unsigned bytes of the destination operand and stores the results to the destination
operand. When an individual result is beyond the range of an unsigned byte (that is,
greater than FFH), the saturated unsigned byte value of FFH is written to the
destination operand.
The PADDUSW instruction adds the unsigned words of the source operand to the
unsigned words of the destination operand and stores the results to the destination
operand. When an individual result is beyond the range of an unsigned word (that is,
greater than FFFFH), the saturated unsigned word value of FFFFH is written to the
destination operand.
4:416
Instruction
PADDUSB mm, mm/m64 Add unsigned packed bytes from mm/m64 to unsigned
PADDUSW mm, mm/m64 Add unsigned packed words from mm/m64 to unsigned
Operation of the PADDUSB Instruction
PADDUSB mm, mm/m64
+ + +
Description
packed bytes in mm and saturate.
packed words in mm and saturate.
Figure 3-7.) If the result of an individual
10000000
+ + +
11111111
11111111 10010110
®
Volume 4: IA-32 Intel MMX™ Technology Instruction Reference
01111111 00111000
+ +
00010111 00000111
00111111
3006017