MOVDQA

Move Aligned Double Quadword

Opcodes

Hex Mnemonic Encoding Long Mode Legacy Mode Description
66 0F 7F /r MOVDQA xmm2/m128, xmm1 B Valid Valid Move aligned double quadword from xmm1 to xmm2/m128.
66 0F 6F /r MOVDQA xmm1, xmm2/m128 A Valid Valid Move aligned double quadword from xmm2/m128 to xmm1.

Instruction Operand Encoding

Op/En Operand 0 Operand 1 Operand 2 Operand 3
A NA NA ModRM:r/m (r) ModRM:reg (w)
B NA NA ModRM:reg (r) ModRM:r/m (w)

Description

Moves a double quadword from the source operand (second operand) to the destination operand (first operand). This instruction can be used to load an XMM register from a 128-bit memory location, to store the contents of an XMM register into a 128-bit memory location, or to move data between two XMM registers. When the source or destination operand is a memory operand, the operand must be aligned on a 16-byte boundary or a general-protection exception (#GP) will be generated.

To move a double quadword to or from unaligned memory locations, use the MOVDQU instruction.

In 64-bit mode, use of the REX.R prefix permits this instruction to access additional registers (XMM8-XMM15).

Pseudo Code

DEST = SRC;
(* #GP if SRC or DEST unaligned memory operand *)

Exceptions

SIMD Floating-Point Exceptions

None.

64-Bit Mode Exceptions

Exception Description
#UD If CR0.EM[bit 2] = 1. If CR4.OSFXSR[bit 9] = 0. If CPUID.01H:EDX.SSE2[bit 26] = 0. If the LOCK prefix is used.
#NM If CR0.TS[bit 3] = 1.
#PF(fault-code) For a page fault.
#GP(0) If the memory address is in a non-canonical form. If memory operand is not aligned on a 16-byte boundary, regardless of segment.
#SS(0) If a memory address referencing the SS segment is in a non-canonical form.

Compatibility Mode Exceptions

Same exceptions as in protected mode.

Virtual-8086 Mode Exceptions

Exception Description
#PF(fault-code) For a page fault.
Same exceptions as in real address mode.

Real-Address Mode Exceptions

Exception Description
#UD If CR0.EM[bit 2] = 1. If CR4.OSFXSR[bit 9] = 0. If CPUID.01H:EDX.SSE2[bit 26] = 0. If the LOCK prefix is used.
#NM If CR0.TS[bit 3] = 1.
#GP If a memory operand is not aligned on a 16-byte boundary, regardless of segment. If any part of the operand lies outside of the effective address space from 0 to FFFFH.

Protected Mode Exceptions

Exception Description
#UD If CR0.EM[bit 2] = 1. If CR4.OSFXSR[bit 9] = 0. If CPUID.01H:EDX.SSE2[bit 26] = 0. If the LOCK prefix is used.
#NM If CR0.TS[bit 3] = 1.
#SS(0) If a memory operand effective address is outside the SS segment limit.
#GP(0) If a memory operand effective address is outside the CS, DS, ES, FS, or GS segment limit. If a memory operand is not aligned on a 16-byte boundary, regardless of segment.
#PF(fault-code) If a page fault occurs.