Intel 64 and IA-32 Architectures Software Developers Manual Volume 2A, Instruction Set Reference, A-M
3-610 Vol. 2
INSTRUCTION SET REFERENCE, A-M
MOVDDUP—Move One Double-FP and Duplicate
Description
The linear address corresponds to the address of the least-significant byte of the
referenced memory data. When a memory address is indicated, the 8 bytes of data
at memory location m64 are loaded. When the register-register form of this opera-
tion is used, the lower half of the 128-bit source register is duplicated and copied into
the 128-bit destination register. See Figure 3-14.
In 64-bit mode, use of the REX.R prefix permits this instruction to access additional
registers (XMM8-XMM15).
Opcode Instruction
64-Bit
Mode
Compat/
Leg Mode Description
F2 0F 12
/r
MOVDDUP xmm1,
xmm2/m64
Valid Valid Move one double-precision floating-
point value from the lower 64-bit
operand in xmm2/m64 to xmm1
and duplicate.
Figure 3-14. MOVDDUP—Move One Double-FP and Duplicate
20
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