Annotations in tree

[drizzle drizzle]

Hi,
   I am trying to find out how to insert annotations for certain array
references identified in tree-loop-linear.c so that when converting to
RTL they can be handled differently.  I find that simply inserting a
flag in the tree node is not enough as optimizations later on can lead
to the node being removed. Can any tell me what else can I do ?

I will appreciate all help....
dz