Intel 253666-024US - Manual (Page 712)

3-666 Vol. 2A MOVQ2DQ—Move Quadword from MMX Technology to XMM Register
INSTRUCTION SET REFERENCE, A-M
MOVQ2DQ—Move Quadword from MMX Technology to XMM Register
Description
Moves the quadword from the source operand (second operand) to the low quadword
of the destination operand (first operand). The source operand is an MMX technology
register and the destination operand is an XMM 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 MOVQ2DQ instruction is executed.
In 64-bit mode, use of the REX.R prefix permits this instruction to access additional
registers (XMM8-XMM15).
Operation
DEST[63:0] ← SRC[63:0];
DEST[127:64] ← 00000000000000000H;
Intel C/C++ Compiler Intrinsic Equivalent
MOVQ2DQ __128i _mm_movpi64_pi64 ( __m64 a)
SIMD Floating-Point Exceptions
None.
Protected Mode Exceptions
#NM If CR0.TS[bit 3] = 1.
#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.
#MF If there is a pending x87 FPU exception.
Real-Address Mode Exceptions
Same exceptions as in protected mode.
Opcode Instruction 64-Bit
Mode
Compat/
Leg Mode
Description
F3 0F D6 MOVQ2DQ xmm, mm Valid Valid Move quadword from mmx to low
quadword of xmm.