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

Vol. 2B 4-391
INSTRUCTION SET REFERENCE, N-Z
UNPCKLPS—Unpack and Interleave Low Packed Single-Precision
Floating-Point Values
Description
Performs an interleaved unpack of the low-order single-precision floating-point
values from the source operand (second operand) and the destination operand (first
operand). See Figure 4-18. The source operand can be an XMM register or a 128-bit
memory location; the destination operand is an XMM register.
When unpacking from a memory operand, an implementation may fetch only the
appropriate 64 bits; however, alignment to 16-byte boundary and normal segment
checking will still be enforced.
In 64-bit mode, using a REX prefix in the form of REX.R permits this instruction to
access additional registers (XMM8-XMM15).
Operation
DEST[31:0] ← DEST[31:0];
DEST[63:32] ← SRC[31:0];
DEST[95:64] ← DEST[63:32];
Opcode Instruction
64-Bit
Mode
Compat/
Leg Mode Description
0F 14 /r UNPCKLPS xmm1,
xmm2/m128
Valid Valid Unpacks and Interleaves single-
precision floating-point values from
low quadwords of xmm1 and
xmm2/mem into xmm1.
Figure 4-18. UNPCKLPS Instruction Low Unpack and Interleave Operation
X3 X2 X1 X0
Y3 Y2 Y1 Y0
Y1 X1 Y0 X0
DEST
SRC
DEST