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 NA ModRM:reg (r, w) ModRM:r/m (r) NA NA
B NA ModRM:r/m (r) VEX.vvvv (r) ModRM:r/m (r) NA
C NA ModRM:r/m (w) ModRM:reg (r) NA NA
D Tuple1 Scalar ModRM:reg (w) EVEX.vvvv (r) ModRM:r/m (r) NA
E Tuple1 Scalar ModRM:r/m (w) ModRM:reg (r) NA NA

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”.