On Sun, Jun 2, 2013 at 7:14 PM, Xinliang David Li <davi...@google.com> wrote:
>
> auto profile info is not available yet in early inlining, why would
> this change make any difference?
Because the check of PARAM_EARLY_INLINING_INSNS is after the check of
cgraph_maybe_hot_edge_p in early inline. If
cgraph_maybe_hot_edge_p fails, the early inline will not happen even
if growth is less than PARAM_EARLY_INLINING_INSNS.
>
> Can you just reset the max_iters to a
> higher value for autoFDO?
We could do that, but it could still lead to some code bloat because
recursive inlines can happen for at most, say 10, iterations.
Dehao
>
> David
>
> On Sun, Jun 2, 2013 at 6:21 PM, Dehao Chen <de...@google.com> wrote:
> > The patch was committed to google-4_8, but it causes problem because
> > einline sets PARAM_EARLY_INLINING_INSNS = 11. This will cause
> > recursive inlining at einline stage (e.g. main->foo, foo->bar,
> > bar->foo) when autofdo is enabled.
> >
> > The following patch can fix the problem by doing more targetted early
> > inlining:
> >
> > Index: gcc/predict.c
> > ===================================================================
> > --- gcc/predict.c (revision 199593)
> > +++ gcc/predict.c (working copy)
> > @@ -175,6 +175,8 @@ cgraph_maybe_hot_edge_p (struct cgraph_edge *edge)
> > && !maybe_hot_count_p (NULL,
> > edge->count))
> > return false;
> > + if (flag_auto_profile)
> > + return false;
> > if (edge->caller->frequency == NODE_FREQUENCY_UNLIKELY_EXECUTED
> > || (edge->callee
> > && edge->callee->frequency == NODE_FREQUENCY_UNLIKELY_EXECUTED))
> >
> > Performance testing on-going...
> >
> > Dehao
> >
> > On Wed, May 29, 2013 at 3:44 PM, Dehao Chen <de...@google.com> wrote:
> >> OK, I'll commit the early inline part.
> >>
> >> Dehao
> >>
> >> On Wed, May 29, 2013 at 10:00 AM, Xinliang David Li <davi...@google.com>
> >> wrote:
> >>> The early inlining part is ok. The tracer optimization should be
> >>> revisited -- we should have more fine grain control on it (for
> >>> instance, based on FDO summary -- but that should be common to
> >>> FDO/LIPO).
> >>>
> >>> David
> >>>
> >>> On Wed, May 29, 2013 at 9:39 AM, Dehao Chen <de...@google.com> wrote:
> >>>> In gcc4-8, the max einline iterations are restricted to 1. For
> >>>> AutoFDO, this is bad because early inline is not size restricted. This
> >>>> patch allows einline to do multiple iterations in AutoFDO. It also
> >>>> enables tracer optimization in AutoFDO.
> >>>>
> >>>> Bootstrapped and passed regression test.
> >>>>
> >>>> OK for googel-4_8?
> >>>>
> >>>> Thanks,
> >>>> Dehao
> >>>>
> >>>> Index: gcc/ipa-inline.c
> >>>> ===================================================================
> >>>> --- gcc/ipa-inline.c (revision 199416)
> >>>> +++ gcc/ipa-inline.c (working copy)
> >>>> @@ -2161,7 +2161,8 @@ early_inliner (void)
> >>>> {
> >>>> /* We iterate incremental inlining to get trivial cases of
> >>>> indirect
> >>>> inlining. */
> >>>> - while (iterations < PARAM_VALUE
> >>>> (PARAM_EARLY_INLINER_MAX_ITERATIONS)
> >>>> + while ((flag_auto_profile
> >>>> + || iterations < PARAM_VALUE (PARAM_EARLY_INLINER_MAX_ITERATIONS))
> >>>> && early_inline_small_functions (node))
> >>>> {
> >>>> timevar_push (TV_INTEGRATION);
> >>>> Index: gcc/opts.c
> >>>> ===================================================================
> >>>> --- gcc/opts.c (revision 199416)
> >>>> +++ gcc/opts.c (working copy)
> >>>> @@ -1644,6 +1644,8 @@ common_handle_option (struct gcc_options *opts,
> >>>> opts->x_flag_peel_loops = value;
> >>>> if (!opts_set->x_flag_value_profile_transformations)
> >>>> opts->x_flag_value_profile_transformations = value;
> >>>> + if (!opts_set->x_flag_tracer)
> >>>> + opts->x_flag_tracer = value;
> >>>> if (!opts_set->x_flag_inline_functions)
> >>>> opts->x_flag_inline_functions = value;
> >>>> if (!opts_set->x_flag_ipa_cp)
