Intel 253666-024US - Manual (Page 666)

3-620 Vol. 2A MOVDDUP—Move One Double-FP and Duplicate
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).
Operation
IF (Source == m64)
THEN
(* Load instruction *)
xmm1[63:0] = m64;
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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