x86 Instruction Set Reference


Move Quadword from XMM to MMX Technology Register

Opcode Mnemonic Description
F2 0F D6 MOVDQ2Q mm, xmm Move low quadword from xmm to MMX technology register.

Moves the low quadword from the source operand (second operand) to the destination operand (first operand). The source operand is an XMM register and the destination operand is an MMX technology register.

This instruction causes a transition from x87 FPU to MMX technology operation (that is, the x87 FPU top-of-stack pointer is set to 0 and the x87 FPU tag word is set to all 0s [valid]). If this instruction is executed while an x87 FPU floating-point exception is pending, the exception is handled before the MOVDQ2Q instruction is executed.

Destination = Source[0..63];
SIMD Floating-Point Exceptions
Protected Mode Exceptions
#NMIf TS in CR0 is set.
#NMIf TS in CR0 is set.
#UDIf EM in CR0 is set. If OSFXSR in CR4 is 0. If CPUID feature flag SSE2 is 0.
Real-Address Mode Exceptions
Same exceptions as in Protected Mode
Virtual-8086 Mode Exceptions
Same exceptions as in Protected Mode
Instruction Latency Throughput Execution Unit
MOVDQ2Q mm, xmm8/8/12/2/1FP_MOVE MMX_ALU