Intel ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS MANUAL VOLUME 1 REV 2.3 Manual page 1745

PSRLW/PSRLD/PSRLQ—Packed Shift Right Logical
Opcode
0F D1 /r
0F 71 /2 ib
0F D2 /r
0F 72 /2 ib
0F D3 /r
0F 73 /2 ib
Description
Shifts the bits in the data elements (words, doublewords, or quadword) in the
destination operand (first operand) to the right by the number of bits specified in the
unsigned count operand (second operand). (See
operation is written to the destination operand. As the bits in the data elements are
shifted right, the empty high-order bits are cleared (set to zero). If the value specified
by the count operand is greater than 15 (for words), 31 (for doublewords), or 63 (for a
quadword), then the destination operand is set to all zeros.
The destination operand must be an MMX technology register; the count operand can
be either an MMX technology register, a 64-bit memory location, or an 8-bit immediate.
The PSRLW instruction shifts each of the four words of the destination operand to the
right by the number of bits specified in the count operand; the PSRLD instruction shifts
each of the two doublewords of the destination operand; and the PSRLQ instruction
shifts the 64-bit quadword in the destination operand. As the individual data elements
are shifted right, the empty high-order bit positions are filled with zeros.
Figure 3-18.
mm
mm
®
Volume 4: IA-32 Intel MMX™ Technology Instruction Reference
Instruction
PSRLW mm, mm/m64
PSRLW mm, imm8
PSRLD mm, mm/m64
PSRLD mm, imm8
PSRLQ mm, mm/m64
PSRLQ mm, imm8
Operation of the PSRLW Instruction
PSRLW mm, 2
shift right
Description
Shift words in mm right by amount specified in mm/m64
while shifting in zeros.
Shift words in mm right by imm8 .
Shift doublewords in mm right by amount specified in
mm/m64 while shifting in zeros.
Shift doublewords in mm right by imm8 .
Shift mm right by amount specified in mm/m64 while
shifting in zeros.
Shift mm right by imm8 while shifting in zeros.
Figure 3-18.) The result of the shift
1111111111111100
shift right shift right
0011111111111111
0001000111000111
shift right
0000010001110001
3006027
4:443