movsd
Move Scalar Double-Precision
MOVSD xmm1, xmm2/m64
Moves a single double (low 64 bits) between XMM/Memory.
Details
Moves a scalar double-precision (64-bit) floating-point value from the source to the low 64 bits of the destination XMM register. The upper 64 bits of the destination XMM register are preserved. No CPU flags are modified. This instruction operates in 32-bit mode or higher.
Pseudocode Operation
dest[63:0] ← src[63:0]
// dest[127:64] unchanged
Example
MOVSD xmm1, xmm2/m64
Encoding
Binary Layout
F2
+0
0F
+1
10
+2
Operands
-
dest
128-bit XMM SIMD register -
src
128-bit XMM SIMD register or Memory operand
Reference (Intel® SDM)
Instruction Forms
| Opcode | Instruction | Op/En | 64/32-bit Mode | CPUID | Description |
|---|---|---|---|---|---|
| F2 0F 10 /r | MOVSD xmm1, xmm2 | A | V/V | SSE2 | Move scalar double precision floating-point value from xmm2 to xmm1 register. |
| F2 0F 10 /r | MOVSD xmm1, m64 | A | V/V | SSE2 | Load scalar double precision floating-point value from m64 to xmm1 register. |
| F2 0F 11 /r | MOVSD xmm1/m64, xmm2 | C | V/V | SSE2 | Move scalar double precision floating-point value from xmm2 register to xmm1/m64. |
| VEX.LIG.F2.0F.WIG 10 /r | VMOVSD xmm1, xmm2, xmm3 | B | V/V | AVX | Merge scalar double precision floating-point value from xmm2 and xmm3 to xmm1 register. |
| VEX.LIG.F2.0F.WIG 10 /r | VMOVSD xmm1, m64 | D | V/V | AVX | Load scalar double precision floating-point value from m64 to xmm1 register. |
| VEX.LIG.F2.0F.WIG 11 /r | VMOVSD xmm1, xmm2, xmm3 | V/V | E AVX | Merge scalar double precision floating-point value from xmm2 and xmm3 registers to xmm1. | |
| VEX.LIG.F2.0F.WIG 11 /r | VMOVSD m64, xmm1 | C | V/V | AVX | Store scalar double precision floating-point value from xmm1 register to m64. |
| EVEX.LLIG.F2.0F.W1 10 /r | VMOVSD xmm1 {k1}{z}, xmm2, xmm3 | B | V/V | AVX512F OR AVX10.1 | Merge scalar double precision floating-point value from xmm2 and xmm3 registers to xmm1 under writemask k1. |
| EVEX.LLIG.F2.0F.W1 10 /r | VMOVSD xmm1 {k1}{z}, m64 | V/V | F AVX512F OR AVX10.1 | Load scalar double precision floating-point value from m64 to xmm1 register under writemask k1. | |
| EVEX.LLIG.F2.0F.W1 11 /r | VMOVSD xmm1 {k1}{z}, xmm2, xmm3 | V/V | E AVX512F OR AVX10.1 | Merge scalar double precision floating-point value from xmm2 and xmm3 registers to xmm1 under writemask k1. | |
| EVEX.LLIG.F2.0F.W1 11 /r | VMOVSD m64 {k1}, xmm1 | V/V | G AVX512F OR AVX10.1 | Store scalar double precision floating-point value from xmm1 register to m64 under writemask k1. |
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 | N/A | ModRM:reg (w) | ModRM:r/m (r) | N/A | N/A |
Description
Moves a scalar double precision floating-point value from the source operand (second operand) to the destination operand (first operand). The source and destination operands can be XMM registers or 64-bit memory locations.
This instruction can be used to move a double precision floating-point value to and from the low quadword of an
XMM register and a 64-bit memory location, or to move a double precision floating-point value between the low quadwords of two XMM registers. The instruction cannot be used to transfer data between memory locations.
Legacy version: When the source and destination operands are XMM registers, bits MAXVL:64 of the destination operand remains unchanged. When the source operand is a memory location and destination operand is an XMM
MOVSD—Move or Merge Scalar Double Precision Floating-Point Value Vol. 2B 4-109 registers, the quadword at bits 127:64 of the destination operand is cleared to all 0s, bits MAXVL:128 of the destination operand remains unchanged.
VEX and EVEX encoded register-register syntax: Moves a scalar double precision floating-point value from the second source operand (the third operand) to the low quadword element of the destination operand (the first operand). Bits 127:64 of the destination operand are copied from the first source operand (the second operand).
Bits (MAXVL-1:128) of the corresponding destination register are zeroed.
VEX and EVEX encoded memory store syntax: When the source operand is a memory location and destination operand is an XMM registers, bits MAXVL:64 of the destination operand is cleared to all 0s.
EVEX encoded versions: The low quadword of the destination is updated according to the writemask.
Note: For VMOVSD (memory store and load forms), VEX.vvvv and EVEX.vvvv are reserved and must be 1111b, otherwise instruction will #UD.
Operation
VMOVSD (EVEX.LLIG.F2.0F 10 /r: VMOVSD xmm1, m64 With Support for 32 Registers) IF k1[0] or *no writemask* THEN DEST[63:0] := SRC[63:0] ELSE IF *merging-masking* ; merging-masking THEN *DEST[63:0] remains unchanged* ELSE ; zeroing-masking THEN DEST[63:0] := 0 FI; FI; DEST[MAXVL-1:64] := 0 VMOVSD (EVEX.LLIG.F2.0F 11 /r: VMOVSD m64, xmm1 With Support for 32 Registers) IF k1[0] or *no writemask* THEN DEST[63:0] := SRC[63:0] ELSE *DEST[63:0] remains unchanged* ; merging-masking FI; VMOVSD (EVEX.LLIG.F2.0F 11 /r: VMOVSD xmm1, xmm2, xmm3) IF k1[0] or *no writemask* THEN DEST[63:0] := SRC2[63:0] ELSE IF *merging-masking* ; merging-masking THEN *DEST[63:0] remains unchanged* ELSE ; zeroing-masking THEN DEST[63:0] := 0 FI; FI; DEST[127:64] := SRC1[127:64] DEST[MAXVL-1:128] := 0 MOVSD (128-bit Legacy SSE Version: MOVSD xmm1, xmm2) DEST[63:0] := SRC[63:0] DEST[MAXVL-1:64] (Unmodified) MOVSD—Move or Merge Scalar Double Precision Floating-Point Value Vol. 2B 4-110 VMOVSD (VEX.128.F2.0F 11 /r: VMOVSD xmm1, xmm2, xmm3) DEST[63:0] := SRC2[63:0] DEST[127:64] := SRC1[127:64] DEST[MAXVL-1:128] := 0 VMOVSD (VEX.128.F2.0F 10 /r: VMOVSD xmm1, xmm2, xmm3) DEST[63:0] := SRC2[63:0] DEST[127:64] := SRC1[127:64] DEST[MAXVL-1:128] := 0 VMOVSD (VEX.128.F2.0F 10 /r: VMOVSD xmm1, m64) DEST[63:0] := SRC[63:0] DEST[MAXVL-1:64] := 0 MOVSD/VMOVSD (128-bit Versions: MOVSD m64, xmm1 or VMOVSD m64, xmm1) DEST[63:0] := SRC[63:0] MOVSD (128-bit Legacy SSE Version: MOVSD xmm1, m64) DEST[63:0] := SRC[63:0] DEST[127:64] := 0 DEST[MAXVL-1:128] (Unmodified)
Intel C/C++ Compiler Intrinsic Equivalent
VMOVSD __m128d _mm_mask_load_sd(__m128d s, __mmask8 k, double * p); VMOVSD __m128d _mm_maskz_load_sd( __mmask8 k, double * p); VMOVSD __m128d _mm_mask_move_sd(__m128d sh, __mmask8 k, __m128d sl, __m128d a); VMOVSD __m128d _mm_maskz_move_sd( __mmask8 k, __m128d s, __m128d a); VMOVSD void _mm_mask_store_sd(double * p, __mmask8 k, __m128d s); MOVSD __m128d _mm_load_sd (double *p) MOVSD void _mm_store_sd (double *p, __m128d a) MOVSD __m128d _mm_move_sd ( __m128d a, __m128d b)
Exceptions
SIMD Floating-Point Exceptions
None.
Other Exceptions
Non-EVEX-encoded instruction, see Table 2-22, “Type 5 Class Exception Conditions,” additionally:
#UD If VEX.vvvv != 1111B.
EVEX-encoded instruction, see Table 2-60, “Type E10 Class Exception Conditions.”
MOVSD—Move or Merge Scalar Double Precision Floating-Point Value Vol. 2B 4-111