On Fri, Nov 13, 2015 at 11:40:56AM +0100, Richard Biener wrote:
> On Fri, Nov 13, 2015 at 11:13 AM, James Greenhalgh
> <[email protected]> wrote:
> >
> > Hi,
> >
> > With all the work that has recently gone in to ifcvt, I thought I'd revisit
> > the branch cost settings for Cortex-A57. After a run of experiments [1],
> > I found {1, 3} to be the sweet spot, giving a small set of performance
> > improvements across some popular benchmarks.
> >
> > I'd therefore like to propose changing the branch cost to those numbers.
> >
> > Patch bootstrapped tuning for Cortex-A57 with no issues. I'll revisit
> > the same for Cortex-A53.
> >
> > OK?
>
> Can you re-do the experiment with adding a LOGICAL_OP_NON_SHORT_CIRCUIT
> target macro for aarch64? It's fallback uses BRANCH_COST (see fold-const.c
> and tree-ssa-ifcombine.c)
This didn't drastically change the results for the workloads I was
using as benchmarks. I'd still pick {1, 3} out as the winner.
Thanks,
James
> > ---
> > 2015-11-12 James Greenhalgh <[email protected]>
> >
> > * config/aarch64/aarch64.c (cortexa57_branch_costs): New.
> > (cortexa57_tunings): Use it.
> >
>
