reg_known_value and copying collection

[Mike Stump]

On Friday, December 13, 2002, at 08:16 AM, Daniel Berlin wrote:
> reg_known_value is a non-root, xcalloc'd array used in alias analysis.
> It contains pointers to rtx'en, and we expect it to be available the 
> whole time from a  call to init_alias_analysis until a call to 
> end_alias_analysis.
>
> CSE ggc_collect's during this time period (IE after init, before end).
> The RTX's reg_known_value has in its array move.
> It gets screwed.
>
> Should reg_known_value be changed to be ggc_alloc'd and made a root?
> Anyone know of other places like this off the top of their head?

qty_table in cse.c:cse_basic_block.  I'm not sure if there are 
collections on the interior, but if there are...  Hopefully it is 
easier for you to check then it is to discover it later.