On Tue, Apr 10, 2012 at 8:43 PM, Igor Zamyatin <izamya...@gmail.com> wrote: > Hi All! > > Here is a patch that enables unroll at O2 for Atom. > > This gives good performance boost on EEMBC 2.0 (~+8% in Geomean for 32 > bits) with quite moderate code size increase (~5% for EEMBC2.0, 32 > bits).
5% is not moderate. Your patch does enable unrolling at -O2 but not -O3, why? Why do you disable register renaming? check_imull requires a function comment. This completely looks like a hack for EEMBC2.0, so it's definitely not ok. -O2 is not supposed to give best benchmark results. Thanks, Richard. > > Tested for i386 and x86-64, ok for trunk? > > Thanks, > Igor > > ChangeLog: > > 2012-04-10 Yakovlev Vladimir <vladimir.b.yakov...@intel.com> > > * gcc/config/i386/i386.c (check_imull): New routine. > (ix86_loop_unroll_adjust): New target hook. > (ix86_option_override_internal): Enable unrolling on Atom at -O2. > (TARGET_LOOP_UNROLL_ADJUST): New define.
