Re: [PATCH GCC][04/06]Add copying interface for dependence_info

[Jeff Law <law@redhat.com>]

On 08/14/2017 03:19 AM, Bin Cheng wrote:
> HI,
> This patch adds copying interface for dependence_info.  The methodology
> is we don't copy such information by default, and this interface should
> be called explicitly when it is safe and necessary to do so.  Just like
> this patch uses the interface in ivopts.
> Bootstrap and test in series.  Is it OK?
> 
> Thanks,
> bin
> 2017-08-10  Bin Cheng  <bin.cheng@arm.com>
> 
> 	* tree-ssa-address.c (copy_dependence_info): New function.
> 	* tree-ssa-address.h (copy_dependence_info): New declaration.
> 	* tree-ssa-loop-ivopts.c (rewrite_use_address): Call above func.
So do we have any structure sharing assumptions on the alias structures?
 ie, are we setting up the possibility that these objects will be shared
and that someone will modify them in a way that works in one context,
but not another?

If they're readonly after creation, then obviously this isn't a concern.

I wouldn't consider this an object or an ACK for the patch at this
point. More a design question we need to answer.

Jeff