MOVSD

Move or Merge Scalar Double Precision Floating-Point Value

stableVMJITAOTinstruction

Encodings

Operand encoding

Each mode is a value of the Op/En column above. It says which field of the encoded instruction carries each operand, in the order they are written, and whether the instruction reads it, writes it or both.

Measured cost

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

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)


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 intrinsics#

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);

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."

Sources

• This instruction in the Intel manual
• Latency and throughput per microarchitecture