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: [PATCH: PR/40314] extract common address for memory access to fields of large struct


On Wed, Jun 3, 2009 at 8:59 AM, Carrot Wei<carrot@google.com> wrote:
> I've tested CSiBE, nearly no changes to code size and compile time. It
> seems there is no large structure in CSiBE to trigger this
> optimization. For mcf from CPU SPEC 2006, this optimization can reduce
> about 7% static instructions.

Alright, counts as an improvement worth pursuing.

What I was wondering though -- isn't this just a special case of Adam
Nemet's "constant anchor" additions to CSE?

You may want to check out
http://gcc.gnu.org/ml/gcc-patches/2009-05/msg01786.html (esp. the
section about TARGET_CONST_ANCHOR.  Isn't this the same optimization
as what you implemented?

Ciao!
Steven


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