MOVHLPS — Move Packed Single-Precision Floating-Point Values High to Low

Opcode/Instruction	Op / En	64/32 bit Mode Support	CPUID Feature Flag	Description
NP 0F 12 /r MOVHLPS xmm1, xmm2	RM	V/V	SSE	Move two packed single-precision floating-point values from high quadword of xmm2 to low quadword of xmm1.
VEX.128.0F.WIG 12 /r VMOVHLPS xmm1, xmm2, xmm3	RVM	V/V	AVX	Merge two packed single-precision floating-point values from high quadword of xmm3 and low quadword of xmm2.
EVEX.128.0F.W0 12 /r VMOVHLPS xmm1, xmm2, xmm3	RVM	V/V	AVX512F	Merge two packed single-precision floating-point values from high quadword of xmm3 and low quadword of xmm2.

Instruction Operand Encoding¹ ¶

1. ModRM.MOD = 011B required

Op/En	Operand 1	Operand 2	Operand 3	Operand 4
RM	ModRM:reg (w)	ModRM:r/m (r)	NA	NA
RVM	ModRM:reg (w)	vvvv (r)	ModRM:r/m (r)	NA

Description ¶

This instruction cannot be used for memory to register moves.

128-bit two-argument form:

Moves two packed single-precision floating-point values from the high quadword of the second XMM argument (second operand) to the low quadword of the first XMM register (first argument). The quadword at bits 127:64 of the destination operand is left unchanged. Bits (MAXVL-1:128) of the corresponding destination register remain unchanged.

128-bit and EVEX three-argument form

Moves two packed single-precision floating-point values from the high quadword of the third XMM argument (third operand) to the low quadword of the destination (first operand). Copies the high quadword from the second XMM argument (second operand) to the high quadword of the destination (first operand). Bits (MAXVL-1:128) of the corresponding destination register are zeroed.

If VMOVHLPS 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 ¶

MOVHLPS (128-bit two-argument form) ¶

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

VMOVHLPS (128-bit three-argument form - VEX & EVEX) ¶

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

Intel C/C++ Compiler Intrinsic Equivalent ¶

MOVHLPS __m128 _mm_movehl_ps(__m128 a, __m128 b)

SIMD Floating-Point Exceptions ¶

None

Other Exceptions ¶

Non-EVEX-encoded instruction, see Exceptions Type 7; additionally

#UD	If VEX.L = 1.

EVEX-encoded instruction, see Exceptions Type E7NM.128.