# MOVHPD — Move High Packed Double Precision Floating-Point Value

Opcode/Instruction | Op / En | 64/32 bit Mode Support | CPUID Feature Flag | Description
--- | --- | --- | --- | ---
66 0F 16 /r MOVHPD xmm1, m64 | A | V/V | SSE2 | Move double precision floating-point value from m64 to high quadword of xmm1.
VEX.128.66.0F.WIG 16 /r VMOVHPD xmm2, xmm1, m64 | B | V/V | AVX | Merge double precision floating-point value from m64 and the low quadword of xmm1.
EVEX.128.66.0F.W1 16 /r VMOVHPD xmm2, xmm1, m64 | D | V/V | AVX512F | Merge double precision floating-point value from m64 and the low quadword of xmm1.
66 0F 17 /r MOVHPD m64, xmm1 | C | V/V | SSE2 | Move double precision floating-point value from high quadword of xmm1 to m64.
VEX.128.66.0F.WIG 17 /r VMOVHPD m64, xmm1 | C | V/V | AVX | Move double precision floating-point value from high quadword of xmm1 to m64.
EVEX.128.66.0F.W1 17 /r VMOVHPD m64, xmm1 | E | V/V | AVX512F | Move double precision floating-point value from high 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:reg (w) | 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 high 64-bits of the destination XMM register. The lower 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 (the third operand) and stores it in the upper 64-bits of the destination XMM register (first operand). The low 64-bits from the first source operand (second operand) are copied to the low 64-bits of the destination. Bits (MAXVL-1:128) of the corresponding destination register are zeroed.

128-bit store:

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

Note: VMOVHPD (store) (VEX.128.66.0F 17 /r) is legal and has the same behavior as the existing 66 0F 17 store. For VMOVHPD (store) VEX.vvvv and EVEX.vvvv are reserved and must be 1111b otherwise instruction will #UD.

If VMOVHPD 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 ¶

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

    DEST[63:0] (Unmodified)
    DEST[127:64] := SRC[63:0]
    DEST[MAXVL-1:128] (Unmodified)

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

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

### VMOVHPD (Store) ¶

    DEST[63:0] := SRC[127:64]

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

    MOVHPD __m128d _mm_loadh_pd ( __m128d a, double *p)

    MOVHPD void _mm_storeh_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.”