On Mon, Sep 16, 2013 at 2:50 PM, Yuri Rumyantsev <ysrum...@gmail.com> wrote: > Hi All, > > Here is 1-line fix which improves Atom performance by better distance > estimation. We got ~20% speedup on one of bench from eembc2.0 with > this fix. > > Bootstrapping and regression testing were successful for x86-64. > > Is it OK for trunk? > > ChangeLog: > > 2013-09-16 Yuri Rumyantsev <ysrum...@gmail.com> > > * config/i386/i386.c (distance_agu_use_in_bb) : Proper initialization > of 'prev' var to get better distance estimation.
Please rewrite this part to: basic_block bb = NULL; rtx next = start; rtx prev = NULL; if (start != NULL_RTX) { bb = BLOCK_FOR_INSN (start); if (start != BB_HEAD (bb)) prev = insn; } A comment would be also nice here. It took me quite some time to decipher the code. OK with these changes. Thanks, Uros.