> I suggest you add this to x86-tune.def and enable it for > bdver3 and bdver4.
The macro TARGET_LOOP_UNROLL_ADJUST is not new. It is already available and is used by target s390. Since it is not an "x86 only" feature I didn't add that in x86-tune.def. Regards Ganesh -----Original Message----- From: H.J. Lu [mailto:hjl.to...@gmail.com] Sent: Thursday, November 21, 2013 12:02 AM To: Gopalasubramanian, Ganesh Cc: gcc-patches@gcc.gnu.org; Uros Bizjak (ubiz...@gmail.com); Richard Guenther <richard.guent...@gmail.com> (richard.guent...@gmail.com); borntrae...@de.ibm.com; Jakub Jelinek (ja...@redhat.com) Subject: Re: [RFC] [PATCH, i386] Adjust unroll factor for bdver3 and bdver4 On Wed, Nov 20, 2013 at 10:26 AM, Gopalasubramanian, Ganesh <ganesh.gopalasubraman...@amd.com> wrote: > Hi, > > Steamroller processors contain a loop predictor and a loop buffer, which may > make unrolling small loops less important. > When unrolling small loops for steamroller, making the unrolled loop fit in > the loop buffer should be a priority. > > This patch uses a heuristic approach (number of memory references) to decide > the unrolling factor for small loops. > This patch has some noise in SPEC 2006 results. > > Bootstrapping passes. > > I would like to know your comments before committing. > I suggest you add this to x86-tune.def and enable it for bdver3 and bdver4. -- H.J.
