This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug tree-optimization/55334] [4.8 Regression] mgrid regression (ipa-cp disables vectorization)
- From: "rguenth at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Wed, 13 Feb 2013 09:09:09 +0000
- Subject: [Bug tree-optimization/55334] [4.8 Regression] mgrid regression (ipa-cp disables vectorization)
- Auto-submitted: auto-generated
- References: <bug-55334-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55334
--- Comment #25 from Richard Biener <rguenth at gcc dot gnu.org> 2013-02-13 09:09:09 UTC ---
(In reply to comment #24)
> Created attachment 29429 [details]
> Experimental patch resolving more dependencies
>
> This is my (untested, highly experimental) patch to resolve such
> dependencies. Basically, it 1) treats MEM_REFs as sort-of
> COMPONENT_REFs on top INDIRECT_REFs and always pushes the offset index
> to access_fns of a data reference structure, and 2) relaxes the rule
> that DR_BASE_OBJECTs need to be the same thing for MEM_REFs of DECLs,
> where we are happy if the DECLs are the same now.
That won't work (read: it will cause miscompiles). I believe with the
most recent data-dependence reorg I added a bunch of testcases that show
how to create breaking testcases ;)