|Opcode/Instruction||Op/En||64/32-bit Mode||CPUID Feature Flag||Description|
66 0F 12 /r
MOVLPD xmm, m64
|RM||V/V||SSE2||Move double-precision floating-point value from m64 to low quadword of xmm register.|
66 0F 13 /r
MOVLPD m64, xmm
|MR||V/V||SSE2||Move double-precision floating-point nvalue from low quadword of xmm register to m64.|
VEX.NDS.128.66.0F.WIG 12 /r
VMOVLPD xmm2, xmm1, m64
|RVM||V/V||AVX||Merge double-precision floating-point value from m64 and the high quadword of xmm1.|
VMOVLPD m64, xmm1
|MR||V/V||AVX||Move double-precision floating-point values from low quadword of xmm1 to m64.|
|Op/En||Operand 1||Operand 2||Operand 3||Operand 4|
|RM||ModRM:reg (r, w)||ModRM:r/m (r)||NA||NA|
|MR||ModRM:r/m (w)||ModRM:reg (r)||NA||NA|
|RVM||ModRM:reg (w)||VEX.vvvv (r)||ModRM:r/m (r)||NA|
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. The upper 128-bits of the corresponding YMM destination register are preserved.
In 64-bit mode, use of the REX.R prefix permits this instruction to access additional registers (XMM8-XMM15).
VEX.128 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). The upper 128-bits of the destination YMM register are zeroed.
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.128.66.0F 13 /r) instruction version, VEX.vvvv is reserved and must be 1111b other-wise instruction will #UD.
If VMOVLPD is encoded with VEX.L= 1, an attempt to execute the instruction encoded with VEX.L= 1 will cause an #UD exception.
MOVLPD (128-bit Legacy SSE load)
DEST[63:0] ← SRC[63:0] DEST[VLMAX-1:64] (Unmodified)
VMOVLPD (VEX.128 encoded load)
DEST[63:0] ← SRC2[63:0] DEST[127:64] ← SRC1[127:64] DEST[VLMAX-1:128] ← 0
DEST[63:0] ← SRC[63:0]
__m128d _mm_loadl_pd ( __m128d a, double *p)
void _mm_storel_pd (double *p, __m128d a)
See Exceptions Type 5; additionally
If VEX.L= 1.
If VEX.vvvv ≠ 1111B.