How to encode multi-byte no-op

[MathMan]

Hi all,

Currently using Lazarus 1.2.4 and FPC 2.6.4 under Windows 7/64 on an Intel x86-64 processor.

I wonder how i can convince the built-in assembler to encode the multi-byte no-operation instruction. The Intel docs state the following re multi-byte no-operation

0F 1F /0 NOP r/m32 Multi-byte no-operation instruction with r/m32 is a standard ModRM:r/m (r)

and it is avail. for all 64 bit x86 processors. I thought that probably combining a nop with an ModRM expression would do the trick - but I only get an "illegal combination of opcode and address" regardless whether I use the AT&T or Intel syntax.

Am I missing something obvious here or is it simply not supported by the built-in assembler?

Kind regards,
MathMan