Embedded Side-Effects

[Rakesh Kumar - Software, Noida]

Hi All,
 
Reading through the documentation of RTL Representation, under the heading
"Embedded Side-Effects on Addresses", I found the following statement which
seems ambiguous to me. It states:
 
"These embedded side effect expressions must be used with care. Instruction
patterns may not use them. Until the flow pass of the compiler, they may
occur only to represent pushes on to the stack."
 
Does it mean that there should be no pre_dec, post_inc, etc in RTL
generation, except in stack pushes? If so, why? Is this statement imposing a
restriction or suggesting something? Suppose I want to do this, will it give
something undesirable?
 
Thanks and Regards
Rakesh Kumar