Minor fixes to ipa-inline-analysis.c

Hi,
while analyzing c-ray I noticed two issues.  First is that I originally set number
of size/time entries to 32.  Once we reach this limit we conservatively account
everything as unconditional.  This limit is not met on relatively simple
testcases, like ray-sphere.  The reason is that aggregate tracking now adds a lot
of new conditionals on individual fields. While number of arguments hardly exceeds
5, the number of fields passed and used easilly. So there is need to increase
the bound.

While propagating info about non-constant parameters, we should also work in
reverse postorder rather than in random order, since we can propagate things 
down across SSA graph.

Bootstrapped/regtested & comitted.

Honza

On Wed, Nov 7, 2012 at 10:25 AM, Jan Hubicka <hubicka@ucw.cz> wrote:
> Hi,
> while analyzing c-ray I noticed two issues.  First is that I originally set number
> of size/time entries to 32.  Once we reach this limit we conservatively account
> everything as unconditional.  This limit is not met on relatively simple
> testcases, like ray-sphere.  The reason is that aggregate tracking now adds a lot
> of new conditionals on individual fields. While number of arguments hardly exceeds
> 5, the number of fields passed and used easilly. So there is need to increase
> the bound.
>
> While propagating info about non-constant parameters, we should also work in
> reverse postorder rather than in random order, since we can propagate things
> down across SSA graph.
>
> Bootstrapped/regtested & comitted.
>
> Honza
>
> Index: ChangeLog
> ===================================================================
> --- ChangeLog   (revision 193284)
> +++ ChangeLog   (working copy)
> @@ -1,3 +1,12 @@
> +2012-11-07  Jan Hubicka  <jh@suse.cz>
> +
> +       * ipa-inline-analysis.c (true_predicate, single_cond_predicate,
> +       reset_inline_edge_summary): Fix
> +       formatting.
> +       (account_size_time): Bump up the limit on number of size/time entries to
> +       256.
> +       (estimate_function_body_sizes): Work in reverse postorder.
> +
>  2012-11-07  David S. Miller  <davem@davemloft.net>
>
>         PR bootstrap/55211
> Index: ipa-inline-analysis.c
> ===================================================================
> --- ipa-inline-analysis.c       (revision 193284)
> +++ ipa-inline-analysis.c       (working copy)
> @@ -149,7 +149,7 @@ static inline struct predicate
>  true_predicate (void)
>  {
>    struct predicate p;
> -  p.clause[0]=0;
> +  p.clause[0] = 0;
>    return p;
>  }
>
> @@ -160,8 +160,8 @@ static inline struct predicate
>  single_cond_predicate (int cond)
>  {
>    struct predicate p;
> -  p.clause[0]=1 << cond;
> -  p.clause[1]=0;
> +  p.clause[0] = 1 << cond;
> +  p.clause[1] = 0;
>    return p;
>  }
>
> @@ -692,12 +692,14 @@ account_size_time (struct inline_summary
>         found = true;
>          break;
>        }
> -  if (i == 32)
> +  if (i == 256)

Shouldn't this be a --param?

>      {
>        i = 0;
>        found = true;
>        e = &VEC_index (size_time_entry, summary->entry, 0);
>        gcc_assert (!e->predicate.clause[0]);
> +      if (dump_file && (dump_flags & TDF_DETAILS))
> +       fprintf (dump_file, "\t\tReached limit on number of entries, ignoring the predicate.");
>      }
>    if (dump_file && (dump_flags & TDF_DETAILS) && (time || size))
>      {
> @@ -970,7 +972,7 @@ reset_inline_edge_summary (struct cgraph
>      {
>        struct inline_edge_summary *es = inline_edge_summary (e);
>
> -      es->call_stmt_size = es->call_stmt_time =0;
> +      es->call_stmt_size = es->call_stmt_time = 0;
>        if (es->predicate)
>         pool_free (edge_predicate_pool, es->predicate);
>        es->predicate = NULL;
> @@ -2280,6 +2282,8 @@ estimate_function_body_sizes (struct cgr
>    struct predicate bb_predicate;
>    struct ipa_node_params *parms_info = NULL;
>    VEC (predicate_t, heap) *nonconstant_names = NULL;
> +  int nblocks, n;
> +  int *order;
>
>    info->conds = 0;
>    info->entry = 0;
> @@ -2312,8 +2316,12 @@ estimate_function_body_sizes (struct cgr
>    gcc_assert (my_function && my_function->cfg);
>    if (parms_info)
>      compute_bb_predicates (node, parms_info, info);
> -  FOR_EACH_BB_FN (bb, my_function)
> +  gcc_assert (cfun == my_function);
> +  order = XNEWVEC (int, n_basic_blocks);
> +  nblocks = pre_and_rev_post_order_compute (NULL, order, false);
> +  for (n = 0; n < nblocks; n++)
>      {
> +      bb = BASIC_BLOCK (order[n]);
>        freq = compute_call_stmt_bb_frequency (node->symbol.decl, bb);
>
>        /* TODO: Obviously predicates can be propagated down across CFG.  */
> @@ -2486,6 +2494,7 @@ estimate_function_body_sizes (struct cgr
>    time = (time + CGRAPH_FREQ_BASE / 2) / CGRAPH_FREQ_BASE;
>    if (time > MAX_TIME)
>      time = MAX_TIME;
> +  free (order);
>
>    if (!early && nonconstant_names)
>      {

> > @@ -692,12 +692,14 @@ account_size_time (struct inline_summary
> >         found = true;
> >          break;
> >        }
> > -  if (i == 32)
> > +  if (i == 256)
> 
> Shouldn't this be a --param?

You are probably right.  ipa-inline-analysis has few hard wired constants in it but mostly
to allow use bitmaps in int and constantly sized arrays for predicates.  It was a plan that
those constants simply won't need tunning.  In this case we can definitely allow user changes.
I will make a patch.

Honza