Intel 253666-024US Manuel D’Utilisation

Page de 760
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 xmmmm
Valid
Valid
Move quadword from mmx to low 
quadword of xmm.