On Mon, Nov 14, 2022 at 11:36 AM Manolis Tsamis <manolis.tsa...@vrull.eu> wrote:
>
> On Mon, Nov 14, 2022 at 9:37 AM Richard Biener
> <richard.guent...@gmail.com> wrote:
> >
> > On Sun, Nov 13, 2022 at 4:38 PM Christoph Muellner
> > <christoph.muell...@vrull.eu> wrote:
> > >
> > > From: mtsamis <manolis.tsa...@vrull.eu>
> > >
> > > The IPA CP pass offers a wide range of optimizations, where most of them
> > > lead to specialized functions that are called from a call site.
> > > This can lead to multiple specialized function clones, if more than
> > > one call-site allows such an optimization.
> > > If not all call-sites can be optimized, the program might end
> > > up with call-sites to the original function.
> > >
> > > This pass assumes that non-optimized call-sites (i.e. call-sites
> > > that don't call specialized functions) are likely to be called
> > > with arguments that would allow calling specialized clones.
> > > Since we cannot guarantee this (for obvious reasons), we can't
> > > replace the existing calls. However, we can introduce dynamic
> > > guards that test the arguments for the collected constants
> > > and calls the specialized function if there is a match.
> > >
> > > To demonstrate the effect, let's consider the following program part:
> > >
> > > func_1()
> > > myfunc(1)
> > > func_2()
> > > myfunc(2)
> > > func_i(i)
> > > myfunc(i)
> > >
> > > In this case the transformation would do the following:
> > >
> > > func_1()
> > > myfunc.constprop.1() // myfunc() with arg0 == 1
> > > func_2()
> > > myfunc.constprop.2() // myfunc() with arg0 == 2
> > > func_i(i)
> > > if (i == 1)
> > > myfunc.constprop.1() // myfunc() with arg0 == 1
> > > else if (i == 2)
> > > myfunc.constprop.2() // myfunc() with arg0 == 2
> > > else
> > > myfunc(i)
> > >
> > > The pass consists of two main parts:
> > > * collecting all specialized functions and the argument/constant pair(s)
> > > * insertion of the guards during materialization
> > >
> > > The patch integrates well into ipa-cp and related IPA functionality.
> > > Given the nature of IPA, the changes are touching many IPA-related
> > > files as well as call-graph data structures.
> > >
> > > The impact of the dynamic guard is expected to be less than the speedup
> > > gained by enabled optimizations (e.g. inlining or constant propagation).
> >
> > I don't see any limits on the number of callee candidates or the complexity
> > of the guard. Is there any reason to not factor the guards into a wrapper
> > function to avoid bloating cold call sites and to allow inlining to decide
> > where the expansion is useful?
> >
>
> There is indeed no limit on the numbers of guards or guard complexity
> currently. Would it be a good choice here to introduce two parameters
> for the maximum number of guards and conditions per guard and assign
> some sane default value?
Yes, that sounds good.
> About the wrapper functions, that is an interesting question that I haven't
> explored as much. One reason is that this transformation aims to work in
> a similar way as the speculative edges (which already existed). Since the
> expected number of guards is low (1-2 in most cases), I considered the
> two optimizations quite similar and wanted to share as much of the design
> and functionality as I could. I also tried to make the overhead of the
> non-specialized original function call as low as possible.
>
> But I can also see how there is a difference in the speculative and
> specialized edges that make creating a wrapper meaningful for
> this case: The maximum speedup of a direct vs indirect function
> call can be much smaller than that of a specialized call instead
> of the generic one.
Yes - IIRC there was also the idea to generally wrap not specialized
calls or to modify the not specialized copy itself.
> > Skimming the patch I noticed an #if 0 commented assert with a comment
> > that this was to be temporary?
> >
>
> Thanks for pointing that out, this is unintentional. I will fix it.
>
> Best,
> Manolis
>
> > Thanks,
> > Richard.
> >
> > > PR ipa/107667
> > > gcc/Changelog:
> > >
> > > * cgraph.cc (cgraph_add_edge_to_call_site_hash): Add support for
> > > guarded specialized edges.
> > > (cgraph_edge::set_call_stmt): Likewise.
> > > (symbol_table::create_edge): Likewise.
> > > (cgraph_edge::remove): Likewise.
> > > (cgraph_edge::make_speculative): Likewise.
> > > (cgraph_edge::make_specialized): Likewise.
> > > (cgraph_edge::remove_specializations): Likewise.
> > > (cgraph_edge::redirect_call_stmt_to_callee): Likewise.
> > > (cgraph_edge::dump_edge_flags): Likewise.
> > > (verify_speculative_call): Likewise.
> > > (verify_specialized_call): Likewise.
> > > (cgraph_node::verify_node): Likewise.
> > > * cgraph.h (class GTY): Add new class that contains info of
> > > specialized edges.
> > > * cgraphclones.cc (cgraph_edge::clone): Add support for guarded
> > > specialized edges.
> > > (cgraph_node::set_call_stmt_including_clones): Likewise.
> > > * ipa-cp.cc (want_remove_some_param_p): Likewise.
> > > (create_specialized_node): Likewise.
> > > (add_specialized_edges): Likewise.
> > > (ipcp_driver): Likewise.
> > > * ipa-fnsummary.cc (redirect_to_unreachable): Likewise.
> > > (ipa_fn_summary_t::duplicate): Likewise.
> > > (analyze_function_body): Likewise.
> > > (estimate_edge_size_and_time): Likewise.
> > > (remap_edge_summaries): Likewise.
> > > * ipa-inline-transform.cc (inline_transform): Likewise.
> > > * ipa-inline.cc (edge_badness): Likewise.
> > > lto-cgraph.cc (lto_output_edge): Likewise.
> > > (input_edge): Likewise.
> > > * tree-inline.cc (copy_bb): Likewise.
> > > * value-prof.cc (gimple_sc): Add function to create guarded
> > > specializations.
> > > * value-prof.h (gimple_sc): Likewise.
> > >
> > > Signed-off-by: Manolis Tsamis <manolis.tsa...@vrull.eu>
> > > ---
> > > gcc/cgraph.cc | 316 +++++++++++++++++++++++++++++++++++-
> > > gcc/cgraph.h | 102 ++++++++++++
> > > gcc/cgraphclones.cc | 30 ++++
> > > gcc/common.opt | 4 +
> > > gcc/ipa-cp.cc | 105 ++++++++++++
> > > gcc/ipa-fnsummary.cc | 42 +++++
> > > gcc/ipa-inline-transform.cc | 11 ++
> > > gcc/ipa-inline.cc | 5 +
> > > gcc/lto-cgraph.cc | 46 ++++++
> > > gcc/tree-inline.cc | 54 ++++++
> > > gcc/value-prof.cc | 214 ++++++++++++++++++++++++
> > > gcc/value-prof.h | 1 +
> > > 12 files changed, 923 insertions(+), 7 deletions(-)
> > >
> > > diff --git a/gcc/cgraph.cc b/gcc/cgraph.cc
> > > index 5851b2ffc6c..ee819c87261 100644
> > > --- a/gcc/cgraph.cc
> > > +++ b/gcc/cgraph.cc
> > > @@ -718,18 +718,24 @@ cgraph_add_edge_to_call_site_hash (cgraph_edge *e)
> > > one indirect); always hash the direct one. */
> > > if (e->speculative && e->indirect_unknown_callee)
> > > return;
> > > + /* There are potentially multiple specialization edges for every
> > > + specialized call; always hash the base egde. */
> > > + if (e->guarded_specialization_edge_p ())
> > > + return;
> > > cgraph_edge **slot = e->caller->call_site_hash->find_slot_with_hash
> > > (e->call_stmt, cgraph_edge_hasher::hash (e->call_stmt), INSERT);
> > > if (*slot)
> > > {
> > > - gcc_assert (((cgraph_edge *)*slot)->speculative);
> > > + gcc_assert (((cgraph_edge *)*slot)->speculative
> > > + || ((cgraph_edge *)*slot)->specialized);
> > > if (e->callee && (!e->prev_callee
> > > || !e->prev_callee->speculative
> > > + || !e->prev_callee->specialized
> > > || e->prev_callee->call_stmt != e->call_stmt))
> > > *slot = e;
> > > return;
> > > }
> > > - gcc_assert (!*slot || e->speculative);
> > > + gcc_assert (!*slot || e->speculative || e->specialized);
> > > *slot = e;
> > > }
> > >
> > > @@ -800,6 +806,23 @@ cgraph_edge::set_call_stmt (cgraph_edge *e, gcall
> > > *new_stmt,
> > > gcc_checking_assert (new_direct_callee);
> > > }
> > >
> > > + /* Update specialized first and do not return yet in case we're dealing
> > > + with an edge that is both specialized and speculative. */
> > > + if (update_speculative && e->specialized)
> > > + {
> > > + cgraph_edge *next, *base = e->specialized_call_base_edge ();
> > > + for (cgraph_edge *d = e->first_specialized_call_target (); d; d =
> > > next)
> > > + {
> > > + next = d->next_specialized_call_target ();
> > > + cgraph_edge *d2 = set_call_stmt (d, new_stmt, false);
> > > + gcc_assert (d2 == d);
> > > + }
> > > +
> > > + /* Don't update base for speculative edges. The code below will.
> > > */
> > > + if (!e->speculative)
> > > + set_call_stmt (base, new_stmt, false);
> > > + }
> > > +
> > > /* Speculative edges has three component, update all of them
> > > when asked to. */
> > > if (update_speculative && e->speculative
> > > @@ -835,12 +858,16 @@ cgraph_edge::set_call_stmt (cgraph_edge *e, gcall
> > > *new_stmt,
> > > return e_indirect ? indirect : direct;
> > > }
> > >
> > > + if (update_speculative && e->specialized)
> > > + return e;
> > > +
> > > if (new_direct_callee)
> > > e = make_direct (e, new_direct_callee);
> > >
> > > /* Only direct speculative edges go to call_site_hash. */
> > > if (e->caller->call_site_hash
> > > && (!e->speculative || !e->indirect_unknown_callee)
> > > + && (!e->specialized || e->spec_args == NULL)
> > > /* It is possible that edge was previously speculative. In this
> > > case
> > > we have different value in call stmt hash which needs
> > > preserving. */
> > > && e->caller->get_edge (e->call_stmt) == e)
> > > @@ -854,11 +881,12 @@ cgraph_edge::set_call_stmt (cgraph_edge *e, gcall
> > > *new_stmt,
> > > /* Update call stite hash. For speculative calls we only record the
> > > first
> > > direct edge. */
> > > if (e->caller->call_site_hash
> > > - && (!e->speculative
> > > + && ((!e->speculative && !e->specialized)
> > > || (e->callee
> > > && (!e->prev_callee || !e->prev_callee->speculative
> > > || e->prev_callee->call_stmt != e->call_stmt))
> > > - || (e->speculative && !e->callee)))
> > > + || (e->speculative && !e->callee)
> > > + || e->base_specialization_edge_p ()))
> > > cgraph_add_edge_to_call_site_hash (e);
> > > return e;
> > > }
> > > @@ -883,7 +911,8 @@ symbol_table::create_edge (cgraph_node *caller,
> > > cgraph_node *callee,
> > > construction of call stmt hashtable. */
> > > cgraph_edge *e;
> > > gcc_checking_assert (!(e = caller->get_edge (call_stmt))
> > > - || e->speculative);
> > > + || e->speculative
> > > + || e->specialized);
> > >
> > > gcc_assert (is_gimple_call (call_stmt));
> > > }
> > > @@ -909,6 +938,8 @@ symbol_table::create_edge (cgraph_node *caller,
> > > cgraph_node *callee,
> > > edge->indirect_info = NULL;
> > > edge->indirect_inlining_edge = 0;
> > > edge->speculative = false;
> > > + edge->specialized = false;
> > > + edge->spec_args = NULL;
> > > edge->indirect_unknown_callee = indir_unknown_callee;
> > > if (call_stmt && caller->call_site_hash)
> > > cgraph_add_edge_to_call_site_hash (edge);
> > > @@ -1066,6 +1097,11 @@ symbol_table::free_edge (cgraph_edge *e)
> > > void
> > > cgraph_edge::remove (cgraph_edge *edge)
> > > {
> > > + /* If we remove the base edge of a group of specialized
> > > + edges then we must also remove all of its specializations. */
> > > + if (edge->base_specialization_edge_p ())
> > > + cgraph_edge::remove_specializations (edge);
> > > +
> > > /* Call all edge removal hooks. */
> > > symtab->call_edge_removal_hooks (edge);
> > >
> > > @@ -1109,6 +1145,8 @@ cgraph_edge::make_speculative (cgraph_node *n2,
> > > profile_count direct_count,
> > > ipa_ref *ref = NULL;
> > > cgraph_edge *e2;
> > >
> > > + gcc_checking_assert (!specialized);
> > > +
> > > if (dump_file)
> > > fprintf (dump_file, "Indirect call -> speculative call %s => %s\n",
> > > n->dump_name (), n2->dump_name ());
> > > @@ -1134,6 +1172,62 @@ cgraph_edge::make_speculative (cgraph_node *n2,
> > > profile_count direct_count,
> > > return e2;
> > > }
> > >
> > > +/* Mark this edge as specialized and add a new edge representing that N2
> > > + is a specialized version of the CALLE of this edge, with the
> > > specialized
> > > + arguments found in SPEC_ARGS. */
> > > +cgraph_edge *
> > > +cgraph_edge::make_specialized (cgraph_node *n2,
> > > + vec<cgraph_specialization_info>*
> > > spec_args,
> > > + profile_count spec_count)
> > > +{
> > > + if (speculative)
> > > + {
> > > + /* Because both speculative and specialized edges use CALL_STMT and
> > > + LTO_STMT_UID to link edges together there is a limitation in
> > > + specializing speculative edges. Only one group of specialized
> > > + edges can exist for a given group of speculative edges. */
> > > + for (cgraph_edge *direct = first_speculative_call_target ();
> > > + direct; direct = direct->next_speculative_call_target ())
> > > + if (direct != this && direct->specialized)
> > > + return NULL;
> > > + }
> > > +
> > > + cgraph_node *n = caller;
> > > + cgraph_edge *e2;
> > > +
> > > + if (dump_file)
> > > + fprintf (dump_file, "Creating guarded specialized edge %s -> %s "
> > > + "from%s callee %s\n",
> > > + caller->dump_name (), n2->dump_name (),
> > > + (speculative? " speculative" : ""),
> > > + callee->dump_name ());
> > > + specialized = true;
> > > + e2 = n->create_edge (n2, call_stmt, spec_count);
> > > +
> > > + /* We don't want to inline the specialized edges seperately. If the
> > > base
> > > + specialized edge is inlined then we will drop the specializations.
> > > */
> > > + e2->inline_failed = CIF_UNSPECIFIED;
> > > + if (TREE_NOTHROW (n2->decl))
> > > + e2->can_throw_external = false;
> > > + else
> > > + e2->can_throw_external = can_throw_external;
> > > +
> > > + e2->specialized = true;
> > > +
> > > + unsigned i;
> > > + cgraph_specialization_info* spec_info;
> > > + vec_alloc (e2->spec_args, spec_args->length ());
> > > +
> > > + FOR_EACH_VEC_ELT (*spec_args, i, spec_info)
> > > + e2->spec_args->quick_push (*spec_info);
> > > +
> > > + e2->lto_stmt_uid = lto_stmt_uid;
> > > + e2->in_polymorphic_cdtor = in_polymorphic_cdtor;
> > > + count -= e2->count;
> > > + symtab->call_edge_duplication_hooks (this, e2);
> > > + return e2;
> > > +}
> > > +
> > > /* Speculative call consists of an indirect edge and one or more
> > > direct edge+ref pairs.
> > >
> > > @@ -1364,6 +1458,39 @@ cgraph_edge::make_direct (cgraph_edge *edge,
> > > cgraph_node *callee)
> > > return edge;
> > > }
> > >
> > > +/* Given the base edge of a group of specialized edges remove all its
> > > + specialized edges. Essentially this can be used to undo the descision
> > > + to specialize EDGE. */
> > > +
> > > +void
> > > +cgraph_edge::remove_specializations (cgraph_edge *edge)
> > > +{
> > > + if (!edge->specialized)
> > > + return;
> > > +
> > > + if (edge->base_specialization_edge_p ())
> > > + {
> > > + cgraph_edge *next;
> > > + for (cgraph_edge *e2 = edge->caller->callees; e2; e2 = next)
> > > + {
> > > + next = e2->next_callee;
> > > +
> > > + if (e2->guarded_specialization_edge_p ()
> > > + && edge->call_stmt == e2->call_stmt
> > > + && edge->lto_stmt_uid == e2->lto_stmt_uid)
> > > + {
> > > + edge->count += e2->count;
> > > + if (e2->inline_failed)
> > > + remove (e2);
> > > + else
> > > + e2->callee->remove_symbol_and_inline_clones ();
> > > + }
> > > + }
> > > + }
> > > + else
> > > + gcc_checking_assert (false);
> > > +}
> > > +
> > > /* Redirect callee of the edge to N. The function does not update
> > > underlying
> > > call expression. */
> > >
> > > @@ -1411,6 +1538,7 @@ cgraph_edge::redirect_call_stmt_to_callee
> > > (cgraph_edge *e)
> > > {
> > > tree decl = gimple_call_fndecl (e->call_stmt);
> > > gcall *new_stmt;
> > > + bool remove_specializations_if_base = true;
> > >
> > > if (e->speculative)
> > > {
> > > @@ -1467,6 +1595,27 @@ cgraph_edge::redirect_call_stmt_to_callee
> > > (cgraph_edge *e)
> > > /* Indirect edges are not both in the call site hash.
> > > get it updated. */
> > > update_call_stmt_hash_for_removing_direct_edge (e, indirect);
> > > +
> > > + if (e->specialized)
> > > + {
> > > + gcc_checking_assert (e->base_specialization_edge_p ());
> > > +
> > > + /* If we're materializing a speculative and base
> > > specialized edge
> > > + then we want to keep the specializations alive. This
> > > amounts
> > > + to changing the call statements of the guarded
> > > + specializations. */
> > > + remove_specializations_if_base = false;
> > > + cgraph_edge *next;
> > > +
> > > + for (cgraph_edge *d = e->first_specialized_call_target ();
> > > + d; d = next)
> > > + {
> > > + next = d->next_specialized_call_target ();
> > > + cgraph_edge *d2 = set_call_stmt (d, new_stmt, false);
> > > + gcc_assert (d2 == d);
> > > + }
> > > + }
> > > +
> > > cgraph_edge::set_call_stmt (e, new_stmt, false);
> > > e->count = gimple_bb (e->call_stmt)->count;
> > >
> > > @@ -1482,6 +1631,53 @@ cgraph_edge::redirect_call_stmt_to_callee
> > > (cgraph_edge *e)
> > > }
> > > }
> > >
> > > + if (e->specialized)
> > > + {
> > > + if (e->spec_args != NULL)
> > > + {
> > > + /* Be sure we redirect all specialized targets before poking
> > > + about base edge. */
> > > + cgraph_edge *base = e->specialized_call_base_edge ();
> > > + gcall *new_stmt;
> > > +
> > > + /* Expand specialization into GIMPLE code. */
> > > + if (dump_file)
> > > + fprintf (dump_file,
> > > + "Expanding specialized call of %s -> %s\n",
> > > + e->caller->dump_name (), e->callee->dump_name ());
> > > +
> > > + push_cfun (DECL_STRUCT_FUNCTION (e->caller->decl));
> > > +
> > > + profile_count all = base->count;
> > > + for (cgraph_edge *e2 = e->first_specialized_call_target ();
> > > + e2; e2 = e2->next_specialized_call_target ())
> > > + all = all + e2->count;
> > > +
> > > + profile_probability prob = e->count.probability_in (all);
> > > + if (!prob.initialized_p ())
> > > + prob = profile_probability::even ();
> > > +
> > > + new_stmt = gimple_sc (e, prob);
> > > + e->specialized = false;
> > > + e->spec_args = NULL;
> > > + if (!base->first_specialized_call_target ())
> > > + base->specialized = false;
> > > +
> > > + cgraph_edge::set_call_stmt (e, new_stmt, false);
> > > + e->count = gimple_bb (e->call_stmt)->count;
> > > + /* Once we are done with expanding the sequence, update also
> > > base
> > > + call probability. Until then the basic block accounts for
> > > the
> > > + sum of specialized edges and all non-expanded
> > > specializations. */
> > > + if (!base->specialized)
> > > + base->count = gimple_bb (base->call_stmt)->count;
> > > +
> > > + pop_cfun ();
> > > + }
> > > + else if (remove_specializations_if_base)
> > > + /* The specialized edges are in part connected by CALL_STMT so if
> > > + we change it for the base edge then remove all
> > > specializations. */
> > > + cgraph_edge::remove_specializations (e);
> > > + }
> > >
> > > if (e->indirect_unknown_callee
> > > || decl == e->callee->decl)
> > > @@ -2069,6 +2265,10 @@ cgraph_edge::dump_edge_flags (FILE *f)
> > > {
> > > if (speculative)
> > > fprintf (f, "(speculative) ");
> > > + if (base_specialization_edge_p ())
> > > + fprintf (f, "(specialized base) ");
> > > + if (guarded_specialization_edge_p ())
> > > + fprintf (f, "(guarded specialization) ");
> > > if (!inline_failed)
> > > fprintf (f, "(inlined) ");
> > > if (call_stmt_cannot_inline_p)
> > > @@ -3313,6 +3513,10 @@ verify_speculative_call (struct cgraph_node *node,
> > > gimple *stmt,
> > > direct = direct->next_callee)
> > > if (direct->call_stmt == stmt && direct->lto_stmt_uid ==
> > > lto_stmt_uid)
> > > {
> > > + /* Guarded specialized edges share the same CALL_STMT and
> > > LTO_STMT_UID
> > > + but are handled separately. */
> > > + if (direct->guarded_specialization_edge_p ())
> > > + continue;
> > > if (!first_call)
> > > first_call = direct;
> > > if (prev_call && direct != prev_call->next_callee)
> > > @@ -3402,6 +3606,93 @@ verify_speculative_call (struct cgraph_node *node,
> > > gimple *stmt,
> > > return false;
> > > }
> > >
> > > +/* Verify consistency of specialized call in NODE corresponding to STMT
> > > + and LTO_STMT_UID. If BASE is set, assume that it is the base
> > > + edge of call sequence. Return true if error is found.
> > > +
> > > + This function is called to every component of specialized call (base
> > > edge
> > > + and specialized edges). To save duplicated work, do full testing only
> > > + when testing the base edge. */
> > > +static bool
> > > +verify_specialized_call (struct cgraph_node *node, gimple *stmt,
> > > + unsigned int lto_stmt_uid,
> > > + struct cgraph_edge *base)
> > > +{
> > > + if (base == NULL)
> > > + {
> > > + cgraph_edge *base;
> > > + for (base = node->callees; base;
> > > + base = base->next_callee)
> > > + if (base->call_stmt == stmt
> > > + && base->lto_stmt_uid == lto_stmt_uid
> > > + && base->spec_args == NULL)
> > > + break;
> > > + if (!base)
> > > + {
> > > + error ("missing base call in specialized call sequence");
> > > + return true;
> > > + }
> > > + if (!base->specialized)
> > > + {
> > > + error ("base call in specialized call sequence has no "
> > > + "specialized flag");
> > > + return true;
> > > + }
> > > + for (base = base->next_callee; base;
> > > + base = base->next_callee)
> > > + if (base->call_stmt == stmt
> > > + && base->lto_stmt_uid == lto_stmt_uid
> > > + && base->spec_args == NULL)
> > > + {
> > > + error ("cannot have more than one base edge in specialized "
> > > + "call sequence");
> > > + return true;
> > > + }
> > > + return false;
> > > + }
> > > +
> > > + cgraph_edge *prev_call = NULL;
> > > +
> > > + cgraph_node *origin_base = base->callee;
> > > + while (origin_base->clone_of)
> > > + origin_base = origin_base->clone_of;
> > > +
> > > + for (cgraph_edge *spec = node->callees; spec;
> > > + spec = spec->next_callee)
> > > + if (spec->call_stmt == stmt
> > > + && spec->lto_stmt_uid == lto_stmt_uid
> > > + && spec->spec_args != NULL)
> > > + {
> > > + cgraph_node *origin_spec = spec->callee;
> > > + while (origin_spec->clone_of)
> > > + origin_spec = origin_spec->clone_of;
> > > +
> > > + if (spec->callee->clone_of && origin_base != origin_spec)
> > > + {
> > > + error ("specialized call to %s in specialized call sequence
> > > has "
> > > + "different origin than base %s %s %s",
> > > + origin_spec->dump_name (), origin_base->dump_name (),
> > > + base->callee->dump_name (), spec->callee->dump_name
> > > ());
> > > + return true;
> > > + }
> > > +
> > > + if (prev_call && spec != prev_call->next_callee)
> > > + {
> > > + error ("specialized edges are not adjacent");
> > > + return true;
> > > + }
> > > + prev_call = spec;
> > > + if (!spec->specialized)
> > > + {
> > > + error ("call to %s in specialized call sequence has no "
> > > + "specialized flag", spec->callee->dump_name ());
> > > + return true;
> > > + }
> > > + }
> > > +
> > > + return false;
> > > +}
> > > +
> > > /* Verify cgraph nodes of given cgraph node. */
> > > DEBUG_FUNCTION void
> > > cgraph_node::verify_node (void)
> > > @@ -3578,6 +3869,7 @@ cgraph_node::verify_node (void)
> > > if (gimple_has_body_p (e->caller->decl)
> > > && !e->caller->inlined_to
> > > && !e->speculative
> > > + && !e->specialized
> > > /* Optimized out calls are redirected to __builtin_unreachable.
> > > */
> > > && (e->count.nonzero_p ()
> > > || ! e->callee->decl
> > > @@ -3604,6 +3896,10 @@ cgraph_node::verify_node (void)
> > > && verify_speculative_call (e->caller, e->call_stmt,
> > > e->lto_stmt_uid,
> > > NULL))
> > > error_found = true;
> > > + if (e->specialized
> > > + && verify_specialized_call (e->caller, e->call_stmt,
> > > e->lto_stmt_uid,
> > > + e->spec_args == NULL? e : NULL))
> > > + error_found = true;
> > > }
> > > for (e = indirect_calls; e; e = e->next_callee)
> > > {
> > > @@ -3612,6 +3908,7 @@ cgraph_node::verify_node (void)
> > > if (gimple_has_body_p (e->caller->decl)
> > > && !e->caller->inlined_to
> > > && !e->speculative
> > > + && !e->specialized
> > > && e->count.ipa_p ()
> > > && count
> > > == ENTRY_BLOCK_PTR_FOR_FN (DECL_STRUCT_FUNCTION
> > > (decl))->count
> > > @@ -3630,6 +3927,11 @@ cgraph_node::verify_node (void)
> > > && verify_speculative_call (e->caller, e->call_stmt,
> > > e->lto_stmt_uid,
> > > e))
> > > error_found = true;
> > > + if (e->specialized || e->spec_args != NULL)
> > > + {
> > > + error ("Cannot have specialized edges in indirect call");
> > > + error_found = true;
> > > + }
> > > }
> > > for (i = 0; iterate_reference (i, ref); i++)
> > > {
> > > @@ -3824,7 +4126,7 @@ cgraph_node::verify_node (void)
> > >
> > > for (e = callees; e; e = e->next_callee)
> > > {
> > > - if (!e->aux && !e->speculative)
> > > + if (!e->aux && !e->speculative && !e->specialized)
> > > {
> > > error ("edge %s->%s has no corresponding call_stmt",
> > > identifier_to_locale (e->caller->name ()),
> > > @@ -3836,7 +4138,7 @@ cgraph_node::verify_node (void)
> > > }
> > > for (e = indirect_calls; e; e = e->next_callee)
> > > {
> > > - if (!e->aux && !e->speculative)
> > > + if (!e->aux && !e->speculative && !e->specialized)
> > > {
> > > error ("an indirect edge from %s has no corresponding
> > > call_stmt",
> > > identifier_to_locale (e->caller->name ()));
> > > diff --git a/gcc/cgraph.h b/gcc/cgraph.h
> > > index 4be67e3cea9..4caed96e803 100644
> > > --- a/gcc/cgraph.h
> > > +++ b/gcc/cgraph.h
> > > @@ -1683,6 +1683,19 @@ public:
> > > unsigned vptr_changed : 1;
> > > };
> > >
> > > +class GTY (()) cgraph_specialization_info
> > > +{
> > > +public:
> > > + unsigned arg_idx;
> > > + int is_unsigned; /* Whether the specialization constant is unsigned.
> > > */
> > > + union
> > > + {
> > > + HOST_WIDE_INT GTY ((tag ("0"))) sval;
> > > + unsigned HOST_WIDE_INT GTY ((tag ("1"))) uval;
> > > + }
> > > + GTY ((desc ("%1.is_unsigned"))) cst;
> > > +};
> > > +
> > > class GTY((chain_next ("%h.next_caller"), chain_prev ("%h.prev_caller"),
> > > for_user)) cgraph_edge
> > > {
> > > @@ -1723,6 +1736,12 @@ public:
> > > */
> > > cgraph_edge *make_speculative (cgraph_node *n2, profile_count
> > > direct_count,
> > > unsigned int speculative_id = 0);
> > > + /* Mark that this edge represents a specialized call to N2.
> > > + SPEC_ARGS represent the position and values of the CALL_STMT of
> > > this edge
> > > + that are specialized in N2. */
> > > + cgraph_edge *make_specialized (cgraph_node *n2,
> > > + vec<cgraph_specialization_info>
> > > *spec_args,
> > > + profile_count spec_count);
> > >
> > > /* Speculative call consists of an indirect edge and one or more
> > > direct edge+ref pairs. Speculative will expand to the following
> > > sequence:
> > > @@ -1802,6 +1821,66 @@ public:
> > > gcc_unreachable ();
> > > }
> > >
> > > + /* Return the first edge that represents a specialization of the
> > > CALL_STMT
> > > + of this edge if one exists or NULL otherwise. */
> > > + cgraph_edge *first_specialized_call_target ()
> > > + {
> > > + gcc_checking_assert (specialized && callee);
> > > + for (cgraph_edge *e2 = caller->callees;
> > > + e2; e2 = e2->next_callee)
> > > + if (e2->guarded_specialization_edge_p ()
> > > + && call_stmt == e2->call_stmt
> > > + && lto_stmt_uid == e2->lto_stmt_uid)
> > > + return e2;
> > > +
> > > + return NULL;
> > > + }
> > > +
> > > + /* Return the next edge that represents a specialization of the
> > > CALL_STMT
> > > + of this edge if one exists or NULL otherwise. */
> > > + cgraph_edge *next_specialized_call_target ()
> > > + {
> > > + cgraph_edge *e = this;
> > > + gcc_checking_assert (specialized && callee);
> > > +
> > > + if (e->next_callee
> > > + && e->next_callee->guarded_specialization_edge_p ()
> > > + && e->next_callee->call_stmt == e->call_stmt
> > > + && e->next_callee->lto_stmt_uid == e->lto_stmt_uid)
> > > + return e->next_callee;
> > > + return NULL;
> > > + }
> > > +
> > > + /* When called on any edge in a specialized call return the (unique)
> > > + edge that points to the non specialized function. */
> > > + cgraph_edge *specialized_call_base_edge ()
> > > + {
> > > + gcc_checking_assert (specialized && callee);
> > > + for (cgraph_edge *e2 = caller->callees;
> > > + e2; e2 = e2->next_callee)
> > > + if (e2->base_specialization_edge_p ()
> > > + && call_stmt == e2->call_stmt
> > > + && lto_stmt_uid == e2->lto_stmt_uid)
> > > + return e2;
> > > +
> > > + return NULL;
> > > + }
> > > +
> > > + /* Return true iff this edge is part of specialized sequence and is the
> > > + original edge for which other specialization edges potentially
> > > exist. */
> > > + bool base_specialization_edge_p () const
> > > + {
> > > + return specialized && spec_args == NULL;
> > > + }
> > > +
> > > + /* Return true iff this edge is part of specialized sequence and it
> > > + represents a potential specialization target that canbe used instead
> > > + of the base edge. */
> > > + bool guarded_specialization_edge_p () const
> > > + {
> > > + return specialized && spec_args != NULL;
> > > + }
> > > +
> > > /* Speculative call edge turned out to be direct call to CALLEE_DECL.
> > > Remove
> > > the speculative call sequence and return edge representing the
> > > call, the
> > > original EDGE can be removed and deallocated. It is up to caller to
> > > @@ -1820,6 +1899,11 @@ public:
> > > static cgraph_edge *resolve_speculation (cgraph_edge *edge,
> > > tree callee_decl = NULL);
> > >
> > > + /* Given the base edge of a group of specialized edges remove all its
> > > + specialized edges. Essentially this can be used to undo the
> > > descision
> > > + to specialize EDGE. */
> > > + static void remove_specializations (cgraph_edge *edge);
> > > +
> > > /* If necessary, change the function declaration in the call statement
> > > associated with edge E so that it corresponds to the edge callee.
> > > Speculations can be resolved in the process and EDGE can be removed
> > > and
> > > @@ -1895,6 +1979,9 @@ public:
> > > /* Additional information about an indirect call. Not cleared when an
> > > edge
> > > becomes direct. */
> > > cgraph_indirect_call_info *indirect_info;
> > > + /* If this edge has a specialized function as a callee then this vector
> > > + holds the indices and values of the specialized arguments. */
> > > + vec<cgraph_specialization_info>* GTY ((skip (""))) spec_args;
> > > void *GTY ((skip (""))) aux;
> > > /* When equal to CIF_OK, inline this call. Otherwise, points to the
> > > explanation why function was not inlined. */
> > > @@ -1933,6 +2020,21 @@ public:
> > > Optimizers may later redirect direct call to clone, so 1) and 3)
> > > do not need to necessarily agree with destination. */
> > > unsigned int speculative : 1;
> > > + /* Edges with SPECIALIZED flag represents calls that have additional
> > > + specialized functions that can be used instead (as a result of
> > > ipa-cp).
> > > + The final code sequence will have form:
> > > +
> > > + if (specialized_arg_0 == specialized_const_0
> > > + && ...
> > > + && specialized_arg_i == specialized_const_i)
> > > + call_target.constprop.N (non_specialized_arg_0, ...);
> > > + ...
> > > + more potential specializations
> > > + ...
> > > + else
> > > + call_target ();
> > > + */
> > > + unsigned int specialized : 1;
> > > /* Set to true when caller is a constructor or destructor of
> > > polymorphic
> > > type. */
> > > unsigned in_polymorphic_cdtor : 1;
> > > diff --git a/gcc/cgraphclones.cc b/gcc/cgraphclones.cc
> > > index bb4b3c5407d..9e12fa19180 100644
> > > --- a/gcc/cgraphclones.cc
> > > +++ b/gcc/cgraphclones.cc
> > > @@ -141,6 +141,20 @@ cgraph_edge::clone (cgraph_node *n, gcall
> > > *call_stmt, unsigned stmt_uid,
> > > new_edge->can_throw_external = can_throw_external;
> > > new_edge->call_stmt_cannot_inline_p = call_stmt_cannot_inline_p;
> > > new_edge->speculative = speculative;
> > > +
> > > + new_edge->specialized = specialized;
> > > + new_edge->spec_args = NULL;
> > > +
> > > + if (spec_args)
> > > + {
> > > + unsigned i;
> > > + cgraph_specialization_info* spec_info;
> > > + vec_alloc (new_edge->spec_args, spec_args->length ());
> > > +
> > > + FOR_EACH_VEC_ELT (*spec_args, i, spec_info)
> > > + new_edge->spec_args->quick_push (*spec_info);
> > > + }
> > > +
> > > new_edge->in_polymorphic_cdtor = in_polymorphic_cdtor;
> > >
> > > /* Update IPA profile. Local profiles need no updating in original.
> > > */
> > > @@ -791,6 +805,22 @@ cgraph_node::set_call_stmt_including_clones (gimple
> > > *old_stmt,
> > > }
> > > indirect->speculative = false;
> > > }
> > > +
> > > + if (edge->specialized && !update_speculative)
> > > + {
> > > + cgraph_edge *base = edge->specialized_call_base_edge ();
> > > +
> > > + for (cgraph_edge *next, *specialized
> > > + = edge->first_specialized_call_target ();
> > > + specialized;
> > > + specialized = next)
> > > + {
> > > + next = specialized->next_specialized_call_target ();
> > > + specialized->specialized = false;
> > > + }
> > > + base->specialized = false;
> > > + }
> > > +
> > > }
> > > if (node->clones)
> > > node = node->clones;
> > > diff --git a/gcc/common.opt b/gcc/common.opt
> > > index bce3e514f65..437f2f4295b 100644
> > > --- a/gcc/common.opt
> > > +++ b/gcc/common.opt
> > > @@ -1933,6 +1933,10 @@ fipa-bit-cp
> > > Common Var(flag_ipa_bit_cp) Optimization
> > > Perform interprocedural bitwise constant propagation.
> > >
> > > +fipa-guarded-specialization
> > > +Common Var(flag_ipa_guarded_specialization) Optimization
> > > +Add speculative edges for existing specialized functions.
> > > +
> > > fipa-modref
> > > Common Var(flag_ipa_modref) Optimization
> > > Perform interprocedural modref analysis.
> > > diff --git a/gcc/ipa-cp.cc b/gcc/ipa-cp.cc
> > > index d2bcd5e5e69..5a24f6987ac 100644
> > > --- a/gcc/ipa-cp.cc
> > > +++ b/gcc/ipa-cp.cc
> > > @@ -119,6 +119,7 @@ along with GCC; see the file COPYING3. If not see
> > > #include "symbol-summary.h"
> > > #include "tree-vrp.h"
> > > #include "ipa-prop.h"
> > > +#include "gimple-pretty-print.h"
> > > #include "tree-pretty-print.h"
> > > #include "tree-inline.h"
> > > #include "ipa-fnsummary.h"
> > > @@ -5239,6 +5240,8 @@ want_remove_some_param_p (cgraph_node *node,
> > > vec<tree> known_csts)
> > > return false;
> > > }
> > >
> > > +static hash_map<cgraph_node*, vec<cgraph_node*>>
> > > *available_specializations;
> > > +
> > > /* Create a specialized version of NODE with known constants in
> > > KNOWN_CSTS,
> > > known contexts in KNOWN_CONTEXTS and known aggregate values in
> > > AGGVALS and
> > > redirect all edges in CALLERS to it. */
> > > @@ -5409,6 +5412,13 @@ create_specialized_node (struct cgraph_node *node,
> > > new_info->known_csts = known_csts;
> > > new_info->known_contexts = known_contexts;
> > >
> > > + if (!info->ipcp_orig_node)
> > > + {
> > > + vec<cgraph_node*> &spec_nodes
> > > + = available_specializations->get_or_insert (node);
> > > + spec_nodes.safe_push (new_node);
> > > + }
> > > +
> > > ipcp_discover_new_direct_edges (new_node, known_csts, known_contexts,
> > > aggvals);
> > >
> > > @@ -6538,6 +6548,96 @@ ipcp_store_vr_results (void)
> > > }
> > > }
> > >
> > > +/* Add new edges to the call graph to represent the available
> > > specializations
> > > + of each specialized function. */
> > > +static void
> > > +add_specialized_edges (void)
> > > +{
> > > + cgraph_edge *e;
> > > + cgraph_node *n, *spec_n;
> > > + tree spec_v;
> > > + unsigned i, j;
> > > +
> > > + FOR_EACH_DEFINED_FUNCTION (n)
> > > + {
> > > + if (dump_file && n->callees)
> > > + fprintf (dump_file,
> > > + "Procesing function %s for specialization of edges.\n",
> > > + n->dump_name ());
> > > +
> > > + if (n->ipcp_clone)
> > > + continue;
> > > +
> > > + bool update = false;
> > > + for (e = n->callees; e; e = e->next_callee)
> > > + {
> > > + if (!e->callee || e->recursive_p ())
> > > + continue;
> > > +
> > > + vec<cgraph_node*> *specialization_nodes
> > > + = available_specializations->get (e->callee);
> > > +
> > > + if (!specialization_nodes)
> > > + continue;
> > > +
> > > + FOR_EACH_VEC_ELT (*specialization_nodes, i, spec_n)
> > > + {
> > > + if (dump_file)
> > > + fprintf (dump_file,
> > > + "Edge has available specialization %s.\n",
> > > + spec_n->dump_name ());
> > > +
> > > + ipa_node_params *spec_params = ipa_node_params_sum->get
> > > (spec_n);
> > > + vec<cgraph_specialization_info> replaced_args = vNULL;
> > > + bool failed = false;
> > > +
> > > + FOR_EACH_VEC_ELT (spec_params->known_csts, j, spec_v)
> > > + {
> > > + if (spec_v != NULL_TREE)
> > > + {
> > > + if (TREE_CODE (spec_v) == INTEGER_CST
> > > + && TYPE_UNSIGNED (TREE_TYPE (spec_v))
> > > + && tree_fits_uhwi_p (spec_v))
> > > + {
> > > + cgraph_specialization_info spec_info;
> > > + spec_info.arg_idx = j;
> > > + spec_info.is_unsigned = 1;
> > > + spec_info.cst.uval = tree_to_uhwi (spec_v);
> > > + replaced_args.safe_push (spec_info);
> > > + }
> > > + else if (TREE_CODE (spec_v) == INTEGER_CST
> > > + && !TYPE_UNSIGNED (TREE_TYPE (spec_v))
> > > + && tree_fits_shwi_p (spec_v))
> > > + {
> > > + cgraph_specialization_info spec_info;
> > > + spec_info.arg_idx = j;
> > > + spec_info.is_unsigned = 0;
> > > + spec_info.cst.uval = tree_to_shwi (spec_v);
> > > + replaced_args.safe_push (spec_info);
> > > + }
> > > + else
> > > + {
> > > + failed = true;
> > > + break;
> > > + }
> > > + }
> > > + }
> > > +
> > > + if (!failed && replaced_args.length () > 0)
> > > + {
> > > + if (e->make_specialized (spec_n,
> > > + &replaced_args,
> > > + e->count.apply_scale (1, 10)))
> > > + update = true;
> > > + }
> > > + }
> > > + }
> > > +
> > > + if (update)
> > > + ipa_update_overall_fn_summary (n);
> > > + }
> > > +}
> > > +
> > > /* The IPCP driver. */
> > >
> > > static unsigned int
> > > @@ -6551,6 +6651,7 @@ ipcp_driver (void)
> > > ipa_check_create_node_params ();
> > > ipa_check_create_edge_args ();
> > > clone_num_suffixes = new hash_map<const char *, unsigned>;
> > > + available_specializations = new hash_map<cgraph_node*,
> > > vec<cgraph_node*>>;
> > >
> > > if (dump_file)
> > > {
> > > @@ -6570,8 +6671,12 @@ ipcp_driver (void)
> > > ipcp_store_bits_results ();
> > > /* Store results of value range propagation. */
> > > ipcp_store_vr_results ();
> > > + /* Add new edges for specializations. */
> > > + if (flag_ipa_guarded_specialization)
> > > + add_specialized_edges ();
> > >
> > > /* Free all IPCP structures. */
> > > + delete available_specializations;
> > > delete clone_num_suffixes;
> > > free_toporder_info (&topo);
> > > delete edge_clone_summaries;
> > > diff --git a/gcc/ipa-fnsummary.cc b/gcc/ipa-fnsummary.cc
> > > index fd3d7d6c5e8..a1f219a056e 100644
> > > --- a/gcc/ipa-fnsummary.cc
> > > +++ b/gcc/ipa-fnsummary.cc
> > > @@ -257,6 +257,13 @@ redirect_to_unreachable (struct cgraph_edge *e)
> > > e = cgraph_edge::resolve_speculation (e, target->decl);
> > > else if (!e->callee)
> > > e = cgraph_edge::make_direct (e, target);
> > > + else if (e->base_specialization_edge_p ())
> > > + {
> > > + /* If the base edge becomes unreachable there's no reason to
> > > + keep the specializations around. */
> > > + cgraph_edge::remove_specializations (e);
> > > + e->redirect_callee (target);
> > > + }
> > > else
> > > e->redirect_callee (target);
> > > class ipa_call_summary *es = ipa_call_summaries->get (e);
> > > @@ -866,6 +873,7 @@ ipa_fn_summary_t::duplicate (cgraph_node *src,
> > > ipa_predicate new_predicate;
> > > class ipa_call_summary *es = ipa_call_summaries->get (edge);
> > > next = edge->next_callee;
> > > + bool update_next = edge->specialized;
> > >
> > > if (!edge->inline_failed)
> > > inlined_to_p = true;
> > > @@ -876,6 +884,9 @@ ipa_fn_summary_t::duplicate (cgraph_node *src,
> > > if (new_predicate == false && *es->predicate != false)
> > > optimized_out_size += es->call_stmt_size *
> > > ipa_fn_summary::size_scale;
> > > edge_set_predicate (edge, &new_predicate);
> > > + /* NEXT may be invalidated for specialized calls. */
> > > + if (update_next)
> > > + next = edge->next_callee;
> > > }
> > >
> > > /* Remap indirect edge predicates with the same simplification as
> > > above.
> > > @@ -2825,6 +2836,29 @@ analyze_function_body (struct cgraph_node *node,
> > > bool early)
> > > es, es3);
> > > }
> > > }
> > > + if (edge->specialized)
> > > + {
> > > + cgraph_edge *base
> > > + = edge->specialized_call_base_edge ();
> > > + ipa_call_summary *es2
> > > + = ipa_call_summaries->get_create (base);
> > > + ipa_call_summaries->duplicate (edge, base,
> > > + es, es2);
> > > +
> > > + /* Edge is the first direct call.
> > > + create and duplicate call summaries for multiple
> > > + speculative call targets. */
> > > + for (cgraph_edge *specialization
> > > + = edge->next_specialized_call_target ();
> > > + specialization; specialization
> > > + = specialization->next_specialized_call_target
> > > ())
> > > + {
> > > + ipa_call_summary *es3
> > > + = ipa_call_summaries->get_create (specialization);
> > > + ipa_call_summaries->duplicate (edge, specialization,
> > > + es, es3);
> > > + }
> > > + }
> > > }
> > >
> > > /* TODO: When conditional jump or switch is known to be
> > > constant, but
> > > @@ -3275,6 +3309,9 @@ estimate_edge_size_and_time (struct cgraph_edge *e,
> > > int *size, int *min_size,
> > > sreal *time, ipa_call_arg_values *avals,
> > > ipa_hints *hints)
> > > {
> > > + if (e->guarded_specialization_edge_p ())
> > > + return;
> > > +
> > > class ipa_call_summary *es = ipa_call_summaries->get (e);
> > > int call_size = es->call_stmt_size;
> > > int call_time = es->call_stmt_time;
> > > @@ -4050,6 +4087,7 @@ remap_edge_summaries (struct cgraph_edge
> > > *inlined_edge,
> > > {
> > > ipa_predicate p;
> > > next = e->next_callee;
> > > + bool update_next = e->specialized;
> > >
> > > if (e->inline_failed)
> > > {
> > > @@ -4073,6 +4111,10 @@ remap_edge_summaries (struct cgraph_edge
> > > *inlined_edge,
> > > params_summary, callee_info,
> > > operand_map, offset_map, possible_truths,
> > > toplev_predicate);
> > > +
> > > + /* NEXT may be invalidated for specialized calls. */
> > > + if (update_next)
> > > + next = e->next_callee;
> > > }
> > > for (e = node->indirect_calls; e; e = next)
> > > {
> > > diff --git a/gcc/ipa-inline-transform.cc b/gcc/ipa-inline-transform.cc
> > > index 07288e57c73..d0b9cd9e599 100644
> > > --- a/gcc/ipa-inline-transform.cc
> > > +++ b/gcc/ipa-inline-transform.cc
> > > @@ -775,11 +775,22 @@ inline_transform (struct cgraph_node *node)
> > > }
> > >
> > > maybe_materialize_called_clones (node);
> > > + /* Perform call statement redirection in two steps. In the first step
> > > + only consider speculative edges and then process the rest in a
> > > separate
> > > + step. This is required due to the potential existance of edges
> > > that are
> > > + both speculative and specialized, in which case we need to process
> > > them
> > > + in this order. */
> > > for (e = node->callees; e; e = next)
> > > {
> > > if (!e->inline_failed)
> > > has_inline = true;
> > > next = e->next_callee;
> > > + if (e->speculative)
> > > + cgraph_edge::redirect_call_stmt_to_callee (e);
> > > + }
> > > + for (e = node->callees; e; e = next)
> > > + {
> > > + next = e->next_callee;
> > > cgraph_edge::redirect_call_stmt_to_callee (e);
> > > }
> > > node->remove_all_references ();
> > > diff --git a/gcc/ipa-inline.cc b/gcc/ipa-inline.cc
> > > index 14969198cde..c6cd2b92f6e 100644
> > > --- a/gcc/ipa-inline.cc
> > > +++ b/gcc/ipa-inline.cc
> > > @@ -1185,12 +1185,17 @@ edge_badness (struct cgraph_edge *edge, bool dump)
> > > edge_time = estimate_edge_time (edge, &unspec_edge_time);
> > > hints = estimate_edge_hints (edge);
> > > gcc_checking_assert (edge_time >= 0);
> > > +
> > > + /* Temporarily disabled due to the way time is calculated
> > > + with specialized edges. */
> > > +#if 0
> > > /* Check that inlined time is better, but tolerate some roundoff
> > > issues.
> > > FIXME: When callee profile drops to 0 we account calls more. This
> > > should be fixed by never doing that. */
> > > gcc_checking_assert ((edge_time * 100
> > > - callee_info->time * 101).to_int () <= 0
> > > || callee->count.ipa ().initialized_p ());
> > > +#endif
> > > gcc_checking_assert (growth <= ipa_size_summaries->get (callee)->size);
> > >
> > > if (dump)
> > > diff --git a/gcc/lto-cgraph.cc b/gcc/lto-cgraph.cc
> > > index 350195d86db..c8250f7b73c 100644
> > > --- a/gcc/lto-cgraph.cc
> > > +++ b/gcc/lto-cgraph.cc
> > > @@ -271,6 +271,8 @@ lto_output_edge (struct lto_simple_output_block *ob,
> > > struct cgraph_edge *edge,
> > > bp_pack_value (&bp, edge->speculative_id, 16);
> > > bp_pack_value (&bp, edge->indirect_inlining_edge, 1);
> > > bp_pack_value (&bp, edge->speculative, 1);
> > > + bp_pack_value (&bp, edge->specialized, 1);
> > > + bp_pack_value (&bp, edge->spec_args != NULL, 1);
> > > bp_pack_value (&bp, edge->call_stmt_cannot_inline_p, 1);
> > > gcc_assert (!edge->call_stmt_cannot_inline_p
> > > || edge->inline_failed != CIF_BODY_NOT_AVAILABLE);
> > > @@ -295,7 +297,27 @@ lto_output_edge (struct lto_simple_output_block *ob,
> > > struct cgraph_edge *edge,
> > > bp_pack_value (&bp,
> > > edge->indirect_info->num_speculative_call_targets,
> > > 16);
> > > }
> > > +
> > > streamer_write_bitpack (&bp);
> > > +
> > > + if (edge->spec_args != NULL)
> > > + {
> > > + cgraph_specialization_info *spec_info;
> > > + unsigned len = edge->spec_args->length (), i;
> > > + streamer_write_uhwi_stream (ob->main_stream, len);
> > > +
> > > + FOR_EACH_VEC_ELT (*edge->spec_args, i, spec_info)
> > > + {
> > > + unsigned idx = spec_info->arg_idx;
> > > + streamer_write_uhwi_stream (ob->main_stream, idx);
> > > + streamer_write_hwi_stream (ob->main_stream,
> > > spec_info->is_unsigned);
> > > +
> > > + if (spec_info->is_unsigned)
> > > + streamer_write_uhwi_stream (ob->main_stream,
> > > spec_info->cst.uval);
> > > + else
> > > + streamer_write_hwi_stream (ob->main_stream,
> > > spec_info->cst.sval);
> > > + }
> > > + }
> > > }
> > >
> > > /* Return if NODE contain references from other partitions. */
> > > @@ -1517,6 +1539,8 @@ input_edge (class lto_input_block *ib,
> > > vec<symtab_node *> nodes,
> > >
> > > edge->indirect_inlining_edge = bp_unpack_value (&bp, 1);
> > > edge->speculative = bp_unpack_value (&bp, 1);
> > > + edge->specialized = bp_unpack_value (&bp, 1);
> > > + bool has_edge_spec_args = bp_unpack_value (&bp, 1);
> > > edge->lto_stmt_uid = stmt_id;
> > > edge->speculative_id = speculative_id;
> > > edge->inline_failed = inline_failed;
> > > @@ -1542,6 +1566,28 @@ input_edge (class lto_input_block *ib,
> > > vec<symtab_node *> nodes,
> > > edge->indirect_info->num_speculative_call_targets
> > > = bp_unpack_value (&bp, 16);
> > > }
> > > +
> > > + if (has_edge_spec_args)
> > > + {
> > > + unsigned len = streamer_read_uhwi (ib);
> > > + vec_alloc (edge->spec_args, len);
> > > +
> > > + for (unsigned i = 0; i < len; i++)
> > > + {
> > > + cgraph_specialization_info spec_info;
> > > + spec_info.arg_idx = streamer_read_uhwi (ib);
> > > + spec_info.is_unsigned = streamer_read_hwi (ib);
> > > +
> > > + if (spec_info.is_unsigned)
> > > + spec_info.cst.uval = streamer_read_uhwi (ib);
> > > + else
> > > + spec_info.cst.sval = streamer_read_hwi (ib);
> > > +
> > > + edge->spec_args->quick_push (spec_info);
> > > + }
> > > + }
> > > + else
> > > + edge->spec_args = NULL;
> > > }
> > >
> > >
> > > diff --git a/gcc/tree-inline.cc b/gcc/tree-inline.cc
> > > index 8091ba8f13b..26657f7c017 100644
> > > --- a/gcc/tree-inline.cc
> > > +++ b/gcc/tree-inline.cc
> > > @@ -2307,6 +2307,60 @@ copy_bb (copy_body_data *id, basic_block bb,
> > > indirect->count
> > > = copy_basic_block->count.apply_probability
> > > (prob);
> > > }
> > > + /* A specialized call is consist of multiple
> > > + edges - a base edge and one or more specialized
> > > edges.
> > > + Duplicate and distribute frequencies in a way
> > > similar
> > > + to the speculative edges. */
> > > + else if (edge->specialized)
> > > + {
> > > + int n = 0;
> > > + cgraph_edge *first
> > > + =
> > > old_edge->first_specialized_call_target ();
> > > + profile_count spec_cnt
> > > + = profile_count::zero ();
> > > +
> > > + /* First figure out the distribution of counts
> > > + so we can re-scale BB profile accordingly.
> > > */
> > > + for (cgraph_edge *e = first; e;
> > > + e = e->next_specialized_call_target ())
> > > + spec_cnt = spec_cnt + e->count;
> > > +
> > > + cgraph_edge *base
> > > + = old_edge->specialized_call_base_edge
> > > ();
> > > + profile_count base_cnt = base->count;
> > > +
> > > + /* Next iterate all specializations, clone them
> > > + and update the profile. */
> > > + for (cgraph_edge *e = first; e;
> > > + e = e->next_specialized_call_target ())
> > > + {
> > > + profile_count cnt = e->count;
> > > +
> > > + edge = e->clone (id->dst_node, call_stmt,
> > > + gimple_uid (stmt), num,
> > > den,
> > > + true);
> > > + profile_probability prob
> > > + = cnt.probability_in (spec_cnt
> > > + + base_cnt);
> > > + edge->count
> > > + =
> > > copy_basic_block->count.apply_probability
> > > + (prob);
> > > + n++;
> > > + }
> > > +
> > > + /* Duplicate the base edge after all specialized
> > > + edges cloned. */
> > > + base = base->clone (id->dst_node, call_stmt,
> > > + gimple_uid (stmt),
> > > + num, den,
> > > + true);
> > > +
> > > + profile_probability prob
> > > + = base_cnt.probability_in (spec_cnt
> > > + + base_cnt);
> > > + base->count
> > > + = copy_basic_block->count.apply_probability
> > > (prob);
> > > + }
> > > else
> > > {
> > > edge = edge->clone (id->dst_node, call_stmt,
> > > diff --git a/gcc/value-prof.cc b/gcc/value-prof.cc
> > > index 9656ce5870d..3db0070bcbf 100644
> > > --- a/gcc/value-prof.cc
> > > +++ b/gcc/value-prof.cc
> > > @@ -42,6 +42,8 @@ along with GCC; see the file COPYING3. If not see
> > > #include "gimple-pretty-print.h"
> > > #include "dumpfile.h"
> > > #include "builtins.h"
> > > +#include "tree-cfg.h"
> > > +#include "tree-dfa.h"
> > >
> > > /* In this file value profile based optimizations are placed. Currently
> > > the
> > > following optimizations are implemented (for more detailed
> > > descriptions
> > > @@ -1434,6 +1436,218 @@ gimple_ic (gcall *icall_stmt, struct cgraph_node
> > > *direct_call,
> > > return dcall_stmt;
> > > }
> > >
> > > +/* Do transformation
> > > +
> > > + if (arg_i == spec_args[y] && ...)
> > > + do call to specialized target callee
> > > + else
> > > + old call
> > > + */
> > > +
> > > +gcall *
> > > +gimple_sc (struct cgraph_edge *edg, profile_probability prob)
> > > +{
> > > + /* The call statement we're modifying. */
> > > + gcall *call_stmt = edg->call_stmt;
> > > + /* The cgraph_node of the specialized function. */
> > > + cgraph_node *callee = edg->callee;
> > > + vec<cgraph_specialization_info> *spec_args = edg->spec_args;
> > > +
> > > + /* CALL_STMT should be the call_stmt of the generic function. */
> > > + gcc_checking_assert (edg->specialized_call_base_edge ()->call_stmt
> > > + == call_stmt);
> > > +
> > > + gcall *spec_call_stmt = NULL;
> > > + tree cond_tree = NULL_TREE;
> > > + gcond *cond_stmt = NULL;
> > > + basic_block cond_bb, dcall_bb, icall_bb, join_bb = NULL;
> > > + edge e_cd, e_ci, e_di, e_dj = NULL, e_ij;
> > > + gimple_stmt_iterator gsi;
> > > + int lp_nr, dflags;
> > > + edge e_eh, e;
> > > + edge_iterator ei;
> > > +
> > > + cond_bb = gimple_bb (call_stmt);
> > > + gsi = gsi_for_stmt (call_stmt);
> > > +
> > > + /* To call the specialized function we need to build a guard
> > > conditional
> > > + with the specialized arguments and constants. */
> > > + unsigned nargs = gimple_call_num_args (call_stmt);
> > > + unsigned cur_spec = 0;
> > > + bool dump_first = true;
> > > +
> > > + if (dump_file)
> > > + {
> > > + fprintf (dump_file, "Creating specialization guard for edge %s ->
> > > %s:\n",
> > > + edg->caller->dump_name (),
> > > edg->callee->dump_name ());
> > > + fprintf (dump_file, "if (");
> > > + }
> > > +
> > > + for (unsigned arg_idx = 0; arg_idx < nargs; arg_idx++)
> > > + {
> > > + tree cur_arg = gimple_call_arg (call_stmt, arg_idx);
> > > + bool cur_arg_specialized_p = cur_spec < spec_args->length ()
> > > + && arg_idx == (*spec_args)[cur_spec].arg_idx;
> > > +
> > > + if (cur_arg_specialized_p)
> > > + {
> > > + gcc_checking_assert (!cond_stmt);
> > > +
> > > + cgraph_specialization_info spec_info = (*spec_args)[cur_spec];
> > > + cur_spec++;
> > > +
> > > + tree spec_v;
> > > + if (spec_info.is_unsigned)
> > > + spec_v = build_int_cstu (integer_type_node,
> > > spec_info.cst.uval);
> > > + else
> > > + spec_v = build_int_cst (integer_type_node,
> > > spec_info.cst.sval);
> > > +
> > > + tree cmp_const = fold_convert (TREE_TYPE (cur_arg), spec_v);
> > > +
> > > + tree cur_arg_eq_spec = build2 (EQ_EXPR, boolean_type_node,
> > > + cur_arg, cmp_const);
> > > +
> > > + if (dump_file)
> > > + {
> > > + if (!dump_first)
> > > + fprintf (dump_file, " && ");
> > > + print_generic_expr (dump_file, cur_arg_eq_spec);
> > > + dump_first = false;
> > > + }
> > > +
> > > + tree tmp1 = make_temp_ssa_name (boolean_type_node, NULL,
> > > "SPEC");
> > > + gassign* load_stmt1 = gimple_build_assign (tmp1,
> > > cur_arg_eq_spec);
> > > + gsi_insert_before (&gsi, load_stmt1, GSI_SAME_STMT);
> > > +
> > > + if (!cond_tree)
> > > + cond_tree = tmp1;
> > > + else
> > > + {
> > > + tree cur_and_prev_true = fold_build2 (BIT_AND_EXPR,
> > > + boolean_type_node,
> > > + cond_tree,
> > > + tmp1);
> > > +
> > > + tree tmp2 = make_temp_ssa_name (boolean_type_node, NULL,
> > > "SPEC");
> > > + gassign* load_stmt2
> > > + = gimple_build_assign (tmp2, cur_and_prev_true);
> > > + gsi_insert_before (&gsi, load_stmt2, GSI_SAME_STMT);
> > > + cond_tree = tmp2;
> > > + }
> > > + }
> > > + }
> > > +
> > > + cond_stmt = gimple_build_cond (EQ_EXPR, cond_tree, boolean_true_node,
> > > + NULL_TREE, NULL_TREE);
> > > +
> > > + gsi_insert_before (&gsi, cond_stmt, GSI_SAME_STMT);
> > > +
> > > + if (gimple_vdef (call_stmt)
> > > + && TREE_CODE (gimple_vdef (call_stmt)) == SSA_NAME)
> > > + {
> > > + unlink_stmt_vdef (call_stmt);
> > > + release_ssa_name (gimple_vdef (call_stmt));
> > > + }
> > > + gimple_set_vdef (call_stmt, NULL_TREE);
> > > + gimple_set_vuse (call_stmt, NULL_TREE);
> > > + update_stmt (call_stmt);
> > > + spec_call_stmt = as_a <gcall *> (gimple_copy (call_stmt));
> > > + gimple_call_set_fndecl (spec_call_stmt, callee->decl);
> > > + dflags = flags_from_decl_or_type (callee->decl);
> > > +
> > > + if ((dflags & ECF_NORETURN) != 0
> > > + && should_remove_lhs_p (gimple_call_lhs (spec_call_stmt)))
> > > + gimple_call_set_lhs (spec_call_stmt, NULL_TREE);
> > > + gsi_insert_before (&gsi, spec_call_stmt, GSI_SAME_STMT);
> > > +
> > > + if (dump_file)
> > > + {
> > > + fprintf (dump_file, ")\n ");
> > > + print_gimple_stmt (dump_file, spec_call_stmt, 0);
> > > + }
> > > +
> > > + e_cd = split_block (cond_bb, cond_stmt);
> > > + dcall_bb = e_cd->dest;
> > > + dcall_bb->count = cond_bb->count.apply_probability (prob);
> > > +
> > > + e_di = split_block (dcall_bb, spec_call_stmt);
> > > + icall_bb = e_di->dest;
> > > + icall_bb->count = cond_bb->count - dcall_bb->count;
> > > +
> > > + if (!stmt_ends_bb_p (call_stmt))
> > > + e_ij = split_block (icall_bb, call_stmt);
> > > + else
> > > + {
> > > + e_ij = find_fallthru_edge (icall_bb->succs);
> > > + if (e_ij != NULL)
> > > + {
> > > + e_ij->probability = profile_probability::always ();
> > > + e_ij = single_pred_edge (split_edge (e_ij));
> > > + }
> > > + }
> > > + if (e_ij != NULL)
> > > + {
> > > + join_bb = e_ij->dest;
> > > + join_bb->count = cond_bb->count;
> > > + }
> > > +
> > > + e_cd->flags = (e_cd->flags & ~EDGE_FALLTHRU) | EDGE_TRUE_VALUE;
> > > + e_cd->probability = prob;
> > > +
> > > + e_ci = make_edge (cond_bb, icall_bb, EDGE_FALSE_VALUE);
> > > + e_ci->probability = prob.invert ();
> > > +
> > > + remove_edge (e_di);
> > > +
> > > + if (e_ij != NULL)
> > > + {
> > > + if ((dflags & ECF_NORETURN) == 0)
> > > + {
> > > + e_dj = make_edge (dcall_bb, join_bb, EDGE_FALLTHRU);
> > > + e_dj->probability = profile_probability::always ();
> > > + }
> > > + e_ij->probability = profile_probability::always ();
> > > + }
> > > +
> > > + if (gimple_call_lhs (call_stmt)
> > > + && TREE_CODE (gimple_call_lhs (call_stmt)) == SSA_NAME
> > > + && (dflags & ECF_NORETURN) == 0)
> > > + {
> > > + tree result = gimple_call_lhs (call_stmt);
> > > + gphi *phi = create_phi_node (result, join_bb);
> > > + gimple_call_set_lhs (call_stmt,
> > > + duplicate_ssa_name (result, call_stmt));
> > > + add_phi_arg (phi, gimple_call_lhs (call_stmt), e_ij,
> > > UNKNOWN_LOCATION);
> > > + gimple_call_set_lhs (spec_call_stmt,
> > > + duplicate_ssa_name (result, spec_call_stmt));
> > > + add_phi_arg (phi, gimple_call_lhs (spec_call_stmt), e_dj,
> > > + UNKNOWN_LOCATION);
> > > + }
> > > +
> > > + lp_nr = lookup_stmt_eh_lp (call_stmt);
> > > + if (lp_nr > 0 && stmt_could_throw_p (cfun, spec_call_stmt))
> > > + {
> > > + add_stmt_to_eh_lp (spec_call_stmt, lp_nr);
> > > + }
> > > +
> > > + FOR_EACH_EDGE (e_eh, ei, icall_bb->succs)
> > > + if (e_eh->flags & (EDGE_EH | EDGE_ABNORMAL))
> > > + {
> > > + e = make_edge (dcall_bb, e_eh->dest, e_eh->flags);
> > > + e->probability = e_eh->probability;
> > > + for (gphi_iterator psi = gsi_start_phis (e_eh->dest);
> > > + !gsi_end_p (psi); gsi_next (&psi))
> > > + {
> > > + gphi *phi = psi.phi ();
> > > + SET_USE (PHI_ARG_DEF_PTR_FROM_EDGE (phi, e),
> > > + PHI_ARG_DEF_FROM_EDGE (phi, e_eh));
> > > + }
> > > + }
> > > + if (!stmt_could_throw_p (cfun, spec_call_stmt))
> > > + gimple_purge_dead_eh_edges (dcall_bb);
> > > + return spec_call_stmt;
> > > +}
> > > +
> > > /* Dump info about indirect call profile. */
> > >
> > > static void
> > > diff --git a/gcc/value-prof.h b/gcc/value-prof.h
> > > index d852c41f33f..7d8be5920b9 100644
> > > --- a/gcc/value-prof.h
> > > +++ b/gcc/value-prof.h
> > > @@ -89,6 +89,7 @@ void verify_histograms (void);
> > > void free_histograms (function *);
> > > void stringop_block_profile (gimple *, unsigned int *, HOST_WIDE_INT *);
> > > gcall *gimple_ic (gcall *, struct cgraph_node *, profile_probability);
> > > +gcall *gimple_sc (struct cgraph_edge *, profile_probability);
> > > bool get_nth_most_common_value (gimple *stmt, const char *counter_type,
> > > histogram_value hist, gcov_type *value,
> > > gcov_type *count, gcov_type *all,
> > > --
> > > 2.38.1
> > >
