This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: Add -fsection-anchors (4.2 project)


Richard Sandiford wrote:

> Well, my last reply was largely trying to argue that the optimisation
> _can_ hurt you, even with base+offset addressing.  The point is that not
> every address calculation is used directly for a load and store.  It might
> be used to compute another address, such as one involving a variable index.
> Or it might be hoisted, stored, or passed to a function.

OK, now I understand what you meant.

> I'm not sure that really helps, but does what I wrote in my last
> reply make any more sense after the above?

Yes, thanks.

> I don't really understand what you're asking for here.  Grouping objects
> into blocks -- in a haphazard order -- doesn't have any direct advantage.
> It only helps if you make use of the information somehow.

Indeed.

> If some future pass
> wants to make use of the information, it's simply a case of adding the
> appropriate condition to use_object_blocks_p.

Right, that's good.

-- 
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]