# MOVLPD — Move Low Packed Double Precision Floating-Point Value

Opcode/Instruction | Op / En | 64/32 bit Mode Support | CPUID Feature Flag | Description
--- | --- | --- | --- | ---
66 0F 12 /r MOVLPD xmm1, m64 | A | V/V | SSE2 | Move double precision floating-point value from m64 to low quadword of xmm1.
VEX.128.66.0F.WIG 12 /r VMOVLPD xmm2, xmm1, m64 | B | V/V | AVX | Merge double precision floating-point value from m64 and the high quadword of xmm1.
EVEX.128.66.0F.W1 12 /r VMOVLPD xmm2, xmm1, m64 | D | V/V | AVX512F | Merge double precision floating-point value from m64 and the high quadword of xmm1.
66 0F 13/r MOVLPD m64, xmm1 | C | V/V | SSE2 | Move double precision floating-point value from low quadword of xmm1 to m64.
VEX.128.66.0F.WIG 13/r VMOVLPD m64, xmm1 | C | V/V | AVX | Move double precision floating-point value from low quadword of xmm1 to m64.
EVEX.128.66.0F.W1 13/r VMOVLPD m64, xmm1 | E | V/V | AVX512F | Move double precision floating-point value from low quadword of xmm1 to m64.

## Instruction Operand Encoding ¶

Op/En | Tuple Type | Operand 1 | Operand 2 | Operand 3 | Operand 4
--- | --- | --- | --- | --- | ---
A | N/A | ModRM:reg (r, w) | ModRM:r/m (r) | N/A | N/A
B | N/A | ModRM:r/m (r) | VEX.vvvv (r) | ModRM:r/m (r) | N/A
C | N/A | ModRM:r/m (w) | ModRM:reg (r) | N/A | N/A
D | Tuple1 Scalar | ModRM:reg (w) | EVEX.vvvv (r) | ModRM:r/m (r) | N/A
E | Tuple1 Scalar | ModRM:r/m (w) | ModRM:reg (r) | N/A | N/A

## Description ¶

This instruction cannot be used for register to register or memory to memory moves.

128-bit Legacy SSE load:

Moves a double precision floating-point value from the source 64-bit memory operand and stores it in the low 64-bits of the destination XMM register. The upper 64bits of the XMM register are preserved. Bits (MAXVL-1:128) of the corresponding destination register are preserved.

VEX.128 & EVEX encoded load:

Loads a double precision floating-point value from the source 64-bit memory operand (third operand), merges it with the upper 64-bits of the first source XMM register (second operand), and stores it in the low 128-bits of the destination XMM register (first operand). Bits (MAXVL-1:128) of the corresponding destination register are zeroed.

128-bit store:

Stores a double precision floating-point value from the low 64-bits of the XMM register source (second operand) to the 64-bit memory location (first operand).

Note: VMOVLPD (store) (VEX.128.66.0F 13 /r) is legal and has the same behavior as the existing 66 0F 13 store. For VMOVLPD (store) VEX.vvvv and EVEX.vvvv are reserved and must be 1111b otherwise instruction will #UD.

If VMOVLPD is encoded with VEX.L or EVEX.L’L= 1, an attempt to execute the instruction encoded with VEX.L or EVEX.L’L= 1 will cause an #UD exception.

## Operation ¶

### MOVLPD (128-bit Legacy SSE Load) ¶

    DEST[63:0] := SRC[63:0]
    DEST[MAXVL-1:64] (Unmodified)

### VMOVLPD (VEX.128 & EVEX Encoded Load) ¶

    DEST[63:0] := SRC2[63:0]
    DEST[127:64] := SRC1[127:64]
    DEST[MAXVL-1:128] := 0

### VMOVLPD (Store) ¶

    DEST[63:0] := SRC[63:0]

## Intel C/C++ Compiler Intrinsic Equivalent ¶

    MOVLPD __m128d _mm_loadl_pd ( __m128d a, double *p)

    MOVLPD void _mm_storel_pd (double *p, __m128d a)

## SIMD Floating-Point Exceptions ¶

None.

## Other Exceptions ¶

Non-EVEX-encoded instruction, see Table 2-22, “Type 5 Class Exception Conditions,” additionally:

#UD | If VEX.L = 1.

EVEX-encoded instruction, see Table 2-57, “Type E9NF Class Exception Conditions.”