On Mon, Nov 14, 2022 at 11:10 AM Richard Biener wrote: > On Mon, Nov 14, 2022 at 10:32 AM Christoph Müllner > wrote: > > > > > > > > On Mon, Nov 14, 2022 at 10:00 AM Richard Biener < > richard.guenther@gmail.com> wrote: > >> > >> On Mon, Nov 14, 2022 at 9:13 AM Christoph Müllner > >> wrote: > >> > > >> > > >> > > >> > On Mon, Nov 14, 2022 at 8:31 AM Richard Biener < > richard.guenther@gmail.com> wrote: > >> >> > >> >> On Sun, Nov 13, 2022 at 4:09 PM Christoph Muellner > >> >> wrote: > >> >> > > >> >> > From: Christoph Müllner > >> >> > > >> >> > This patch adds a new pass that looks up function pointer > assignments, > >> >> > and adds guarded direct calls to the call sites of the function > >> >> > pointers. > >> >> > > >> >> > E.g.: Lets assume an assignment to a function pointer as follows: > >> >> > b->cb = &myfun; > >> >> > Other part of the program can use the function pointer as > follows: > >> >> > b->cb (); > >> >> > With this pass the invocation will be transformed to: > >> >> > if (b->cb == myfun) > >> >> > myfun(); > >> >> > else > >> >> > b->cb () > >> >> > > >> >> > The impact of the dynamic guard is expected to be less than the > speedup > >> >> > gained by enabled optimizations (e.g. inlining or constant > propagation). > >> >> > >> >> We have speculative devirtualization doing this very transform, > shouldn't you > >> >> instead improve that instead of inventing another specialized pass? > >> > > >> > > >> > Yes, it can be integrated into ipa-devirt. > >> > > >> > The reason we initially decided to move it into its own file was that > C++ devirtualization > >> > and function pointer dereferencing/devirtualization will likely not > use the same analysis. > >> > E.g. ODR only applies to C++, C++ tables are not directly exposed to > the user. > >> > So we figured that different things should not be merged together, > but a reuse > >> > of common code to avoid duplication is mandatory. > >> > >> Btw, in other context the idea came up to build candidates based on > available > >> API/ABI (that can be indirectly called). That would help for example > the > >> get_ref calls in refine_subpel in the x264 benchmark. Maybe what you > >> do is actually > >> the very same thing (but look for explicit address-taking) - I didn't > >> look into whether > >> you prune the list of candidates based on API/ABI. > > > > > > No, I don't consider API/ABI at all (do you have a pointer so I can get > a better understanding of that idea?). > > No, it was just an idea discussed internally. > > > Adding guards for all possible functions with the same API/ABI seems > expensive (I might misunderstand the idea). > > My patch adds a maximum of 1 test per call site. > > > > What I do is looking which addresses are assigned to the function > pointer. > > If there is more than one assigned function, I drop the function pointer > from the list of candidates. > > OK. If the program is type correct that's probably going to work well > enough. If there are more than > one candidates then you could prune those by simple API checks, like > match up the number of arguments > or void vs. non-void return type. More advanced pruning might lose > some valid candidates (API vs. > ABI compatibility), but it's only heuristic pruning in any case. > > It would probably help depending on what exactly "assigned to the > function pointer" means. If the > function pointer is not from directly visible static storage then > matching up assignments and uses > is going to be a difficult IPA problem itself. So our original idea was > for > > (*fnptr) (args ...); > > look for all possible definitions in the (LTO) unit that match the > call signature and that have their > address taken and that possibly could be pointed to by fnptr and if > that's a single one, speculatively > devirtualize that. > Understood. That's an interesting idea. Assuming that functions with identical signatures are rare, both approaches should find similar candidates. I wonder why the API/ABI compatibility checks are needed if we only consider functions assigned to a function pointer. I.e. if call-site and callee don't match, wouldn't the indirect call suffer from the same incompatibility? The patch currently looks at the following properties of the RHS of a function pointer assignment: * rhs = gimple_assign_rhs1 (stmt) * rhs_t = TREE_TYPE (rhs) * possible_decl = TREE_OPERAND (rhs, 0) * node = cgraph_node::get (possible_decl) And the following rules are currently enforced: * TREE_CODE (rhs) == ADDR_EXPR * TREE_CODE (rhs_t) == POINTER_TYPE * TREE_CODE (TREE_TYPE (rhs_t)) == FUNCTION_TYPE * TREE_CODE (possible_decl) == FUNCTION_DECL > > I just checked in the dump file, and the patch also dereferences the > indirect calls to get_ref in refine_subpel. > > IIRC the x264 case has a global variable with all the function > pointers so your implementation > will likely pick up the single assignment to the individual fields. > > Richard. > > > > >> > >> > >> > The patch uses the same API like speculative devirtualization in the > propagation > >> > phase (ipa_make_edge_direct_to_target) and does not do anything in the > >> > transformation phase. So there is no duplication of functionality. > >> > > >> > I will move the code into ipa-devirt. > >> > > >> > Thanks! > >> > > >> > > >> >> > >> >> > >> >> Thanks, > >> >> Richard. > >> >> > >> >> > PR ipa/107666 > >> >> > gcc/ChangeLog: > >> >> > > >> >> > * Makefile.in: Add new pass. > >> >> > * common.opt: Add flag -fipa-guarded-deref. > >> >> > * lto-section-in.cc: Add new section "ipa_guarded_deref". > >> >> > * lto-streamer.h (enum lto_section_type): Add new section. > >> >> > * passes.def: Add new pass. > >> >> > * timevar.def (TV_IPA_GUARDED_DEREF): Add time var. > >> >> > * tree-pass.h (make_pass_ipa_guarded_deref): New prototype. > >> >> > * ipa-guarded-deref.cc: New file. > >> >> > > >> >> > Signed-off-by: Christoph Müllner > >> >> > --- > >> >> > gcc/Makefile.in | 1 + > >> >> > gcc/common.opt | 4 + > >> >> > gcc/ipa-guarded-deref.cc | 1115 > ++++++++++++++++++++++++++++++++++++++ > >> >> > gcc/lto-section-in.cc | 1 + > >> >> > gcc/lto-streamer.h | 1 + > >> >> > gcc/passes.def | 1 + > >> >> > gcc/timevar.def | 1 + > >> >> > gcc/tree-pass.h | 1 + > >> >> > 8 files changed, 1125 insertions(+) > >> >> > create mode 100644 gcc/ipa-guarded-deref.cc > >> >> > > >> >> > diff --git a/gcc/Makefile.in b/gcc/Makefile.in > >> >> > index f672e6ea549..402c4a6ea3f 100644 > >> >> > --- a/gcc/Makefile.in > >> >> > +++ b/gcc/Makefile.in > >> >> > @@ -1462,6 +1462,7 @@ OBJS = \ > >> >> > ipa-sra.o \ > >> >> > ipa-devirt.o \ > >> >> > ipa-fnsummary.o \ > >> >> > + ipa-guarded-deref.o \ > >> >> > ipa-polymorphic-call.o \ > >> >> > ipa-split.o \ > >> >> > ipa-inline.o \ > >> >> > diff --git a/gcc/common.opt b/gcc/common.opt > >> >> > index bce3e514f65..8344940ae5b 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-deref > >> >> > +Common Var(flag_ipa_guarded_deref) Optimization > >> >> > +Perform guarded function pointer derferencing. > >> >> > + > >> >> > fipa-modref > >> >> > Common Var(flag_ipa_modref) Optimization > >> >> > Perform interprocedural modref analysis. > >> >> > diff --git a/gcc/ipa-guarded-deref.cc b/gcc/ipa-guarded-deref.cc > >> >> > new file mode 100644 > >> >> > index 00000000000..198fb9b33ad > >> >> > --- /dev/null > >> >> > +++ b/gcc/ipa-guarded-deref.cc > >> >> > @@ -0,0 +1,1115 @@ > >> >> > +/* IPA pass to transform indirect calls to guarded direct calls. > >> >> > + Copyright (C) 2022 Free Software Foundation, Inc. > >> >> > + Contributed by Christoph Muellner (Vrull GmbH) > >> >> > + Based on work by Erick Ochoa (Vrull GmbH) > >> >> > + > >> >> > +This file is part of GCC. > >> >> > + > >> >> > +GCC is free software; you can redistribute it and/or modify it > under > >> >> > +the terms of the GNU General Public License as published by the > Free > >> >> > +Software Foundation; either version 3, or (at your option) any > later > >> >> > +version. > >> >> > + > >> >> > +GCC is distributed in the hope that it will be useful, but > WITHOUT ANY > >> >> > +WARRANTY; without even the implied warranty of MERCHANTABILITY or > >> >> > +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public > License > >> >> > +for more details. > >> >> > + > >> >> > +You should have received a copy of the GNU General Public License > >> >> > +along with GCC; see the file COPYING3. If not see > >> >> > +. */ > >> >> > + > >> >> > +/* Indirect calls are used to separate callees from their call > sites. > >> >> > + This helps to implement proper abstraction layers, but prevents > >> >> > + optimizations like constant-propagation or function > specialization. > >> >> > + > >> >> > + Assuming that we identify a function pointer that gets assigned > >> >> > + only a small amount of times, we can convert the indirect calls > >> >> > + to the target function into guarded direct calls and let later > >> >> > + passes apply additional optimizations. > >> >> > + > >> >> > + This pass does this by: > >> >> > + * Identifying function pointers that are assigned up to N=1 > times > >> >> > + to struct fields. > >> >> > + * Convert the indirect calls into a test for the call target > >> >> > + and a direct call > >> >> > + * If the test fails, then the indirect call will be executed. > >> >> > + > >> >> > + E.g.: > >> >> > + - function foo's address is taken and stored in a field of > struct > >> >> > + o->func = foo; > >> >> > + - the program writes into this struct field only once > >> >> > + - it is possible, that we miss a store (we would need strong > guarantees) > >> >> > + therefore, we do the following conversion: > >> >> > + o->func () > >> >> > + <--> > >> >> > + if (o->func == foo) > >> >> > + foo () > >> >> > + else > >> >> > + o->func () > >> >> > + > >> >> > + This pass is implemented as a full IPA pass that uses the LTO > section > >> >> > + "ipa_guarded_deref". */ > >> >> > + > >> >> > +#include "config.h" > >> >> > +#include "system.h" > >> >> > +#include "coretypes.h" > >> >> > +#include "backend.h" > >> >> > +#include "tree.h" > >> >> > +#include "gimple.h" > >> >> > +#include "alloc-pool.h" > >> >> > +#include "tree-pass.h" > >> >> > +#include "tree-cfg.h" > >> >> > +#include "ssa.h" > >> >> > +#include "cgraph.h" > >> >> > +#include "gimple-pretty-print.h" > >> >> > +#include "gimple-iterator.h" > >> >> > +#include "symbol-summary.h" > >> >> > +#include "ipa-utils.h" > >> >> > + > >> >> > +#include "attr-fnspec.h" > >> >> > +#include "gimple-ssa.h" > >> >> > +#include "data-streamer.h" > >> >> > +#include "lto-streamer.h" > >> >> > +#include "print-tree.h" > >> >> > +#include "calls.h" > >> >> > +#include "gimple-fold.h" > >> >> > +#include "tree-vrp.h" > >> >> > +#include "ipa-prop.h" > >> >> > +#include "ipa-fnsummary.h" > >> >> > +#include "demangle.h" > >> >> > +#include "dbgcnt.h" > >> >> > +#include "intl.h" > >> >> > +#include "stringpool.h" > >> >> > +#include "attribs.h" > >> >> > +#include "streamer-hooks.h" > >> >> > + > >> >> > +#include "alloc-pool.h" > >> >> > +#include "tree-pass.h" > >> >> > +#include "gimple-iterator.h" > >> >> > +#include "tree-dfa.h" > >> >> > +#include "cgraph.h" > >> >> > +#include "ipa-utils.h" > >> >> > +#include "symbol-summary.h" > >> >> > +#include "gimple-pretty-print.h" > >> >> > +#include "gimple-walk.h" > >> >> > +#include "print-tree.h" > >> >> > +#include "tree-streamer.h" > >> >> > +#include "alias.h" > >> >> > +#include "calls.h" > >> >> > +#include "ipa-modref-tree.h" > >> >> > +#include "ipa-modref.h" > >> >> > +#include "value-range.h" > >> >> > +#include "ipa-prop.h" > >> >> > +#include "ipa-fnsummary.h" > >> >> > +#include "attr-fnspec.h" > >> >> > +#include "symtab-clones.h" > >> >> > +#include "gimple-ssa.h" > >> >> > +#include "tree-phinodes.h" > >> >> > +#include "tree-ssa-operands.h" > >> >> > +#include "ssa-iterators.h" > >> >> > +#include "stringpool.h" > >> >> > +#include "tree-ssanames.h" > >> >> > +#include "attribs.h" > >> >> > +#include "tree-cfg.h" > >> >> > +#include "tree-eh.h" > >> >> > +#include "hash-traits.h" > >> >> > + > >> >> > +/* Struct that holds a function pointer type. > >> >> > + In our context a function pointer type is a record-field pair, > >> >> > + with the field being of a function pointer type. */ > >> >> > + > >> >> > +struct function_pointer_type > >> >> > +{ > >> >> > + /* Record type hosting the function pointer. */ > >> >> > + tree record; > >> >> > + /* field_decl of the function pointer. */ > >> >> > + tree field; > >> >> > +}; > >> >> > + > >> >> > +/* Add a default hash trait for the type function_pointer_type, > so it can be used > >> >> > + as key in hash collections (hash_map, hash_set, etc.). */ > >> >> > + > >> >> > +template <> > >> >> > +struct default_hash_traits > >> >> > + : typed_noop_remove > >> >> > +{ > >> >> > + GTY((skip)) typedef function_pointer_type value_type; > >> >> > + GTY((skip)) typedef function_pointer_type compare_type; > >> >> > + static hashval_t > >> >> > + hash (function_pointer_type p) > >> >> > + { > >> >> > + return TYPE_UID (p.record) ^ DECL_UID (p.field); > >> >> > + } > >> >> > + static const bool empty_zero_p = true; > >> >> > + static bool > >> >> > + is_empty (function_pointer_type p) > >> >> > + { > >> >> > + return p.record == NULL_TREE; > >> >> > + } > >> >> > + static bool > >> >> > + is_deleted (function_pointer_type p ATTRIBUTE_UNUSED) > >> >> > + { > >> >> > + return false; > >> >> > + } > >> >> > + static bool > >> >> > + equal (const function_pointer_type &l, > >> >> > + const function_pointer_type &r) > >> >> > + { > >> >> > + return (l.record == r.record) && (l.field == r.field); > >> >> > + } > >> >> > + static void > >> >> > + mark_empty (function_pointer_type &p) > >> >> > + { > >> >> > + p.record = NULL_TREE; > >> >> > + p.field = NULL_TREE; > >> >> > + } > >> >> > + static void > >> >> > + mark_deleted (function_pointer_type &p) > >> >> > + { > >> >> > + p.record = NULL_TREE; > >> >> > + p.field = NULL_TREE; > >> >> > + } > >> >> > +}; > >> >> > + > >> >> > +/* Store a call target to a function-pointer-type. > >> >> > + With this class we can correlate a field-record-pair > >> >> > + with a function pointer field with a call target. > >> >> > + > >> >> > + We maintain a 1:N mapping here, i.e. a fpt can have exactly 1 > call target, > >> >> > + but a call target can be referenced by multiple fpts. > >> >> > + > >> >> > + Note, that the information needs to be extracted with > >> >> > + the function pointer type as key and the call target as value. > >> >> > + However, on call graph modification events, we need a reverse > >> >> > + lookup (currenlty we don't optimize this code path). */ > >> >> > + > >> >> > +class function_pointer_type_assignments > >> >> > +{ > >> >> > +private: > >> >> > + /* Track function-pointer-types and their assigned call > targets. */ > >> >> > + hash_map m_assignments; > >> >> > + > >> >> > +public: > >> >> > + function_pointer_type_assignments () {} > >> >> > + > >> >> > + /* Get the call target for a function pointer type (if any). */ > >> >> > + cgraph_node *get_target (const function_pointer_type &v) > >> >> > + { > >> >> > + cgraph_node **pnode = m_assignments.get (v); > >> >> > + return pnode ? *pnode : NULL; > >> >> > + } > >> >> > + > >> >> > + /* Add a new assignment for a function pointer type. */ > >> >> > + > >> >> > + void > >> >> > + add_assignment (function_pointer_type fpt, cgraph_node *target) > >> >> > + { > >> >> > + bool existed_p; > >> >> > + cgraph_node *&node = m_assignments.get_or_insert (fpt, > &existed_p); > >> >> > + if (existed_p) > >> >> > + /* More, than one target -> set call target to NULL > (unknown). */ > >> >> > + node = NULL; > >> >> > + else > >> >> > + node = target; > >> >> > + } > >> >> > + > >> >> > + /* Print all stored information. */ > >> >> > + > >> >> > + void > >> >> > + print (void) > >> >> > + { > >> >> > + if (!dump_file) > >> >> > + return; > >> >> > + > >> >> > + fprintf (dump_file, > >> >> > + "Collected the following function pointer > assignments:\n"); > >> >> > + > >> >> > + hash_map::iterator iter > >> >> > + = m_assignments.begin (); > >> >> > + for (; iter != m_assignments.end (); ++iter) > >> >> > + { > >> >> > + function_pointer_type fpt = (*iter).first; > >> >> > + cgraph_node* callee = (*iter).second; > >> >> > + > >> >> > + if (fpt.record == NULL_TREE > >> >> > + || fpt.field == NULL_TREE > >> >> > + || callee == NULL) > >> >> > + continue; > >> >> > + > >> >> > + fprintf (dump_file, " "); > >> >> > + print_generic_expr (dump_file, fpt.record, TDF_NONE); > >> >> > + fprintf (dump_file, "::"); > >> >> > + print_generic_expr (dump_file, fpt.field, TDF_NONE); > >> >> > + fprintf (dump_file, " := %s\n", callee ? callee->name () > : ""); > >> >> > + } > >> >> > + } > >> >> > + > >> >> > + /* Callback for node removal. */ > >> >> > + > >> >> > + void > >> >> > + remove (cgraph_node *node) > >> >> > + { > >> >> > + /* Iterators are not removal-safe. > >> >> > + Therefore we need to advance the iterator before > >> >> > + we delete the element pointed to by the iterator. > >> >> > + To do so, we use a helper pointer. */ > >> >> > + function_pointer_type to_delete; > >> >> > + bool delete_fpt = false; > >> >> > + > >> >> > + /* We iterate over all entries, which is not optimal. > >> >> > + To improve this, we need a way for a reverse-lookup. */ > >> >> > + hash_map::iterator iter > >> >> > + = m_assignments.begin (); > >> >> > + for (; iter != m_assignments.end (); ++iter) > >> >> > + { > >> >> > + /* Deletion comes *after* iterator advancement. */ > >> >> > + if (delete_fpt) > >> >> > + { > >> >> > + m_assignments.remove (to_delete); > >> >> > + delete_fpt = false; > >> >> > + } > >> >> > + > >> >> > + /* Get the cgraph node and check if it matches. */ > >> >> > + cgraph_node* n = (*iter).second; > >> >> > + if (n == node) > >> >> > + { > >> >> > + /* Mark for removal (see above). */ > >> >> > + to_delete = (*iter).first; > >> >> > + delete_fpt = true; > >> >> > + } > >> >> > + } > >> >> > + > >> >> > + /* Deletion comes *after* iterator advancement. */ > >> >> > + if (delete_fpt) > >> >> > + { > >> >> > + m_assignments.remove (to_delete); > >> >> > + delete_fpt = false; > >> >> > + } > >> >> > + } > >> >> > + > >> >> > + void > >> >> > + serialize (struct output_block *ob, lto_symtab_encoder_t > &encoder) > >> >> > + { > >> >> > + unsigned HOST_WIDE_INT elements = m_assignments.elements (); > >> >> > + > >> >> > + /* Write the number of elements. */ > >> >> > + streamer_write_uhwi (ob, elements); > >> >> > + > >> >> > + hash_map::iterator iter > >> >> > + = m_assignments.begin (); > >> >> > + for (; iter != m_assignments.end (); ++iter) > >> >> > + { > >> >> > + /* Write the function pointer type. */ > >> >> > + function_pointer_type fpt = (*iter).first; > >> >> > + stream_write_tree_ref (ob, fpt.record); > >> >> > + stream_write_tree_ref (ob, fpt.field); > >> >> > + > >> >> > + /* Write the callee. */ > >> >> > + unsigned HOST_WIDE_INT symid; > >> >> > + cgraph_node* callee = (*iter).second; > >> >> > + if (callee) > >> >> > + symid = lto_symtab_encoder_encode (encoder, callee); > >> >> > + else > >> >> > + symid = 0; > >> >> > + > >> >> > + streamer_write_uhwi (ob, symid); > >> >> > + } > >> >> > + } > >> >> > + > >> >> > + void > >> >> > + deserialize (lto_input_block &ib, class data_in *data_in, > >> >> > + lto_symtab_encoder_t &encoder) > >> >> > + { > >> >> > + size_t elements = streamer_read_uhwi (&ib); > >> >> > + for (size_t i = 0; i < elements; i++) > >> >> > + { > >> >> > + /* Read the function pointer type. */ > >> >> > + function_pointer_type fpt; > >> >> > + fpt.record = stream_read_tree_ref (&ib, data_in); > >> >> > + fpt.field = stream_read_tree_ref (&ib, data_in); > >> >> > + > >> >> > + /* Read the callee. */ > >> >> > + cgraph_node *callee = NULL; > >> >> > + unsigned HOST_WIDE_INT symid = streamer_read_uhwi (&ib); > >> >> > + if (symid) > >> >> > + { > >> >> > + symtab_node *scallee = lto_symtab_encoder_deref > (encoder, symid); > >> >> > + callee = dyn_cast (scallee); > >> >> > + } > >> >> > + > >> >> > + /* Add the function pointer type assignment. */ > >> >> > + add_assignment (fpt, callee); > >> >> > + } > >> >> > + } > >> >> > + > >> >> > + ~function_pointer_type_assignments () {} > >> >> > +}; > >> >> > + > >> >> > +/* Store a record-field-pair to a call graph edge. > >> >> > + With this class we can correlate an indirect call with > >> >> > + the field-record-pair of its call site. > >> >> > + > >> >> > + Note, that the information needs to be extracted with > >> >> > + the edge as key and the function pointer type as value. */ > >> >> > + > >> >> > +class indirect_call_summary > >> >> > + : public call_summary > >> >> > +{ > >> >> > +public: > >> >> > + indirect_call_summary (symbol_table *table) > >> >> > + : call_summary (table) > >> >> > + { } > >> >> > + > >> >> > + /* Hook that is called by summary when an edge is duplicated. > */ > >> >> > + virtual void duplicate (cgraph_edge *src ATTRIBUTE_UNUSED, > >> >> > + cgraph_edge *dst ATTRIBUTE_UNUSED, > >> >> > + function_pointer_type *old_fpt, > >> >> > + function_pointer_type *new_fpt) > >> >> > + { > >> >> > + /* We may not have record-field-pair, because not every edge > >> >> > + is an indirect call. */ > >> >> > + if (!old_fpt) > >> >> > + return; > >> >> > + > >> >> > + new_fpt->record = old_fpt->record; > >> >> > + new_fpt->field = old_fpt->field; > >> >> > + } > >> >> > + > >> >> > + /* Print all stored information. */ > >> >> > + > >> >> > + void > >> >> > + print (void) > >> >> > + { > >> >> > + if (!dump_file) > >> >> > + return; > >> >> > + > >> >> > + fprintf (dump_file, > >> >> > + "Collected the following indirect calls:\n"); > >> >> > + > >> >> > + cgraph_node *caller = NULL; > >> >> > + FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (caller) > >> >> > + { > >> >> > + for (cgraph_edge *e = caller->indirect_calls; e; e = > e->next_callee) > >> >> > + { > >> >> > + function_pointer_type *fpt = get (e); > >> >> > + if (fpt && fpt->record && fpt->field) > >> >> > + { > >> >> > + fprintf (dump_file, " "); > >> >> > + fprintf (dump_file, "%s -> ", caller->name ()); > >> >> > + print_generic_expr (dump_file, fpt->record, > TDF_NONE); > >> >> > + fprintf (dump_file, "::"); > >> >> > + print_generic_expr (dump_file, fpt->field, > TDF_NONE); > >> >> > + fprintf (dump_file, "\n"); > >> >> > + } > >> >> > + } > >> >> > + } > >> >> > + } > >> >> > + > >> >> > + void > >> >> > + serialize (struct output_block *ob, lto_symtab_encoder_t > encoder) > >> >> > + { > >> >> > + unsigned HOST_WIDE_INT elements = 0; > >> >> > + > >> >> > + /* We iterate over all (cnodes x edges) and store all that > have > >> >> > + additional information stored. */ > >> >> > + > >> >> > + lto_symtab_encoder_iterator it; > >> >> > + for (it = lsei_start_function_in_partition (encoder); > !lsei_end_p (it); > >> >> > + lsei_next_function_in_partition (&it)) > >> >> > + { > >> >> > + cgraph_node *node = lsei_cgraph_node (it); > >> >> > + if (node->has_gimple_body_p ()) > >> >> > + elements++; > >> >> > + } > >> >> > + > >> >> > + /* Write the number of elements. */ > >> >> > + streamer_write_uhwi (ob, elements); > >> >> > + > >> >> > + for (it = lsei_start_function_in_partition (encoder); > !lsei_end_p (it); > >> >> > + lsei_next_function_in_partition (&it)) > >> >> > + { > >> >> > + cgraph_node *caller = lsei_cgraph_node (it); > >> >> > + if (!caller->has_gimple_body_p ()) > >> >> > + continue; > >> >> > + > >> >> > + /* Write caller. */ > >> >> > + unsigned HOST_WIDE_INT symid = lto_symtab_encoder_encode > (encoder, > >> >> > + > caller); > >> >> > + streamer_write_uhwi (ob, symid); > >> >> > + > >> >> > + for (cgraph_edge *e = caller->indirect_calls; e; e = > e->next_callee) > >> >> > + { > >> >> > + function_pointer_type *fpt = get (e); > >> >> > + if (fpt && fpt->record && fpt->field) > >> >> > + { > >> >> > + /* Write the function pointer type. */ > >> >> > + stream_write_tree_ref (ob, fpt->record); > >> >> > + stream_write_tree_ref (ob, fpt->field); > >> >> > + } > >> >> > + else > >> >> > + { > >> >> > + stream_write_tree_ref (ob, NULL_TREE); > >> >> > + stream_write_tree_ref (ob, NULL_TREE); > >> >> > + } > >> >> > + } > >> >> > + } > >> >> > + } > >> >> > + > >> >> > + void > >> >> > + deserialize (lto_input_block &ib, class data_in *data_in, > >> >> > + lto_symtab_encoder_t &encoder) > >> >> > + { > >> >> > + /* Read the number of elements. */ > >> >> > + size_t elements = streamer_read_uhwi (&ib); > >> >> > + > >> >> > + for (size_t i = 0; i < elements; i++) > >> >> > + { > >> >> > + /* Read caller. */ > >> >> > + unsigned HOST_WIDE_INT symid = streamer_read_uhwi (&ib); > >> >> > + symtab_node *scaller = lto_symtab_encoder_deref > (encoder, symid); > >> >> > + cgraph_node *caller = dyn_cast (scaller); > >> >> > + > >> >> > + for (cgraph_edge *e = caller->indirect_calls; e; e = > e->next_callee) > >> >> > + { > >> >> > + tree record = stream_read_tree_ref (&ib, data_in); > >> >> > + tree field = stream_read_tree_ref (&ib, data_in); > >> >> > + if (record == NULL_TREE && field == NULL_TREE) > >> >> > + continue; > >> >> > + > >> >> > + function_pointer_type *fpt = get_create (e); > >> >> > + fpt->record = record; > >> >> > + fpt->field = field; > >> >> > + } > >> >> > + } > >> >> > + } > >> >> > +}; > >> >> > + > >> >> > +class gimple_walker > >> >> > +{ > >> >> > +public: > >> >> > + gimple_walker () {} > >> >> > + > >> >> > + void walk (void* data); > >> >> > + > >> >> > +protected: > >> >> > + /* Overload these callbacks. */ > >> >> > + virtual void walk_gassign (__attribute__ ((unused)) > cgraph_node*, > >> >> > + __attribute__ ((unused)) gassign*, > >> >> > + __attribute__ ((unused)) void*) {} > >> >> > + virtual void walk_gcall (__attribute__ ((unused)) cgraph_node*, > >> >> > + __attribute__ ((unused)) gcall*, > >> >> > + __attribute__ ((unused)) void*) {} > >> >> > + > >> >> > +private: > >> >> > + /* Will walk declarations, locals, ssa names, and basic > blocks. */ > >> >> > + void _walk_cnode (cgraph_node *cnode, void *data); > >> >> > + > >> >> > + /* Iterate over all basic blocks in CNODE. */ > >> >> > + void _walk_bb (cgraph_node *cnode, basic_block bb, void *data); > >> >> > + > >> >> > + /* Iterate over all gimple_stmt in BB. */ > >> >> > + void _walk_gimple (cgraph_node *cnode, gimple *stmt, void > *data); > >> >> > +}; > >> >> > + > >> >> > +void > >> >> > +gimple_walker::walk (void *data) > >> >> > +{ > >> >> > + hash_set fndecls2; > >> >> > + cgraph_node *node = NULL; > >> >> > + > >> >> > + FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node) > >> >> > + { > >> >> > + node->get_body (); > >> >> > + tree decl = node->decl; > >> >> > + gcc_assert (decl); > >> >> > + const bool already_in_set = fndecls2.contains (decl); > >> >> > + > >> >> > + /* I think it is possible for different nodes to point to > the same > >> >> > + declaration. */ > >> >> > + if (already_in_set) > >> >> > + continue; > >> >> > + > >> >> > + if (dump_file) > >> >> > + dump_function_to_file (node->decl, dump_file, TDF_NONE); > >> >> > + > >> >> > + _walk_cnode (node, data); > >> >> > + > >> >> > + /* Add to set of known declarations. */ > >> >> > + fndecls2.add (decl); > >> >> > + } > >> >> > +} > >> >> > + > >> >> > +/* Walk over all basic blocks in CNODE. */ > >> >> > + > >> >> > +void > >> >> > +gimple_walker::_walk_cnode (cgraph_node *cnode, void *data) > >> >> > +{ > >> >> > + cnode->get_body (); > >> >> > + tree decl = cnode->decl; > >> >> > + gcc_assert (decl); > >> >> > + > >> >> > + function *func = DECL_STRUCT_FUNCTION (decl); > >> >> > + gcc_assert (func); > >> >> > + > >> >> > + basic_block bb = NULL; > >> >> > + > >> >> > + push_cfun (func); > >> >> > + FOR_EACH_BB_FN (bb, func) > >> >> > + { > >> >> > + _walk_bb (cnode, bb, data); > >> >> > + } > >> >> > + pop_cfun (); > >> >> > +} > >> >> > + > >> >> > +/* Walk over each gimple statement in BB. */ > >> >> > + > >> >> > +void > >> >> > +gimple_walker::_walk_bb (cgraph_node *cnode, basic_block bb, void > *data) > >> >> > +{ > >> >> > + gimple_stmt_iterator gsi; > >> >> > + for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) > >> >> > + { > >> >> > + gimple *stmt = gsi_stmt (gsi); > >> >> > + _walk_gimple (cnode, stmt, data); > >> >> > + } > >> >> > +} > >> >> > + > >> >> > +/* Switch for different gimple instruction types. */ > >> >> > + > >> >> > +void > >> >> > +gimple_walker::_walk_gimple (cgraph_node *cnode, gimple *stmt, > void *data) > >> >> > +{ > >> >> > + const enum gimple_code code = gimple_code (stmt); > >> >> > + switch (code) > >> >> > + { > >> >> > + case GIMPLE_ASSIGN: > >> >> > + { > >> >> > + gassign *assign = dyn_cast (stmt); > >> >> > + walk_gassign (cnode, assign, data); > >> >> > + break; > >> >> > + } > >> >> > + case GIMPLE_CALL: > >> >> > + { > >> >> > + gcall *call = dyn_cast (stmt); > >> >> > + walk_gcall (cnode, call, data); > >> >> > + break; > >> >> > + } > >> >> > + default: > >> >> > + break; > >> >> > + } > >> >> > +} > >> >> > + > >> >> > +class gimple_assignment_collector : public gimple_walker > >> >> > +{ > >> >> > +protected: > >> >> > + virtual void walk_gassign (cgraph_node *cnode, gassign *stmt, > void *data) > >> >> > + { > >> >> > + if (dump_file) > >> >> > + fprintf (dump_file, "%s: Entering.\n", __func__); > >> >> > + > >> >> > + function_pointer_type_assignments *fpas > >> >> > + = (function_pointer_type_assignments*) data; > >> >> > + > >> >> > + tree lhs = gimple_assign_lhs (stmt); > >> >> > + gcc_assert (lhs); > >> >> > + > >> >> > + /* We only care about a rhs which is a variable or a > constant. > >> >> > + Therefore, we only need to look at unary or single rhs. > */ > >> >> > + const enum gimple_rhs_class gclass = > gimple_assign_rhs_class (stmt); > >> >> > + if (gclass != GIMPLE_UNARY_RHS > >> >> > + && gclass != GIMPLE_SINGLE_RHS) > >> >> > + { > >> >> > + if (dump_file) > >> >> > + fprintf (dump_file, "%s: RHS class not matching.\n", > __func__); > >> >> > + return; > >> >> > + } > >> >> > + > >> >> > + tree rhs = gimple_assign_rhs1 (stmt); > >> >> > + > >> >> > + if (dump_file) > >> >> > + { > >> >> > + fprintf (dump_file, "%s: Analysing assignment:\n", > __func__); > >> >> > + fprintf (dump_file, " Function: %s\n", cnode->name ()); > >> >> > + fprintf (dump_file, " LHS: "); > >> >> > + print_generic_expr (dump_file, lhs, TDF_NONE); > >> >> > + fprintf (dump_file, "\n RHS: "); > >> >> > + print_generic_expr (dump_file, rhs, TDF_NONE); > >> >> > + fprintf (dump_file, "\n"); > >> >> > + } > >> >> > + > >> >> > + /* We are only interested in function pointers. */ > >> >> > + tree rhs_t = TREE_TYPE (rhs); > >> >> > + tree lhs_t = TREE_TYPE (lhs); > >> >> > + if (TREE_CODE (rhs_t) != POINTER_TYPE > >> >> > + || TREE_CODE (lhs_t) != POINTER_TYPE) > >> >> > + { > >> >> > + if (dump_file) > >> >> > + fprintf (dump_file, "%s: LHS not pointer type.\n", > __func__); > >> >> > + return; > >> >> > + } > >> >> > + if (TREE_CODE (TREE_TYPE (rhs_t)) != FUNCTION_TYPE > >> >> > + || TREE_CODE (TREE_TYPE (lhs_t)) != FUNCTION_TYPE) > >> >> > + { > >> >> > + if (dump_file) > >> >> > + fprintf (dump_file, "%s: RHS not function type.\n", > __func__); > >> >> > + return; > >> >> > + } > >> >> > + > >> >> > + /* We only care about function pointers assigned to fields. > >> >> > + So we look for COMPONENT_REF. */ > >> >> > + const enum tree_code code = TREE_CODE (lhs); > >> >> > + if (code != COMPONENT_REF) > >> >> > + { > >> >> > + if (dump_file) > >> >> > + fprintf (dump_file, "%s: LHS not component ref.\n", > __func__); > >> >> > + return; > >> >> > + } > >> >> > + > >> >> > + tree base = TREE_OPERAND (lhs, 0); > >> >> > + tree base_t = TREE_TYPE (base); > >> >> > + > >> >> > + /* We either have a record or a pointer to a record. */ > >> >> > + if (TREE_CODE (base_t) == POINTER_TYPE) > >> >> > + base_t = TREE_TYPE (base_t); > >> >> > + > >> >> > + if (TREE_CODE (base_t) != RECORD_TYPE) > >> >> > + { > >> >> > + if (dump_file) > >> >> > + { > >> >> > + fprintf (dump_file, "%s: Base type not record > type.\n", __func__); > >> >> > + fprintf (dump_file, "%s: base: ", __func__); > >> >> > + print_generic_expr (dump_file, base, TDF_DETAILS); > >> >> > + fprintf (dump_file, "%s: base_t: ", __func__); > >> >> > + print_generic_expr (dump_file, base_t, TDF_DETAILS); > >> >> > + } > >> >> > + return; > >> >> > + } > >> >> > + > >> >> > + /* We only care about addr expressions. */ > >> >> > + if (TREE_CODE (rhs) != ADDR_EXPR) > >> >> > + { > >> >> > + if (dump_file) > >> >> > + fprintf (dump_file, "%s: RHS is not addr expr.\n", > __func__); > >> >> > + return; > >> >> > + } > >> >> > + > >> >> > + tree possible_decl = TREE_OPERAND (rhs, 0); > >> >> > + if (TREE_CODE (possible_decl) != FUNCTION_DECL) > >> >> > + { > >> >> > + if (dump_file) > >> >> > + fprintf (dump_file, "%s: RHS addr expr is not a > function decl.\n", > >> >> > + __func__); > >> >> > + return; > >> >> > + } > >> >> > + > >> >> > + tree field = TREE_OPERAND (lhs, 1); > >> >> > + > >> >> > + /* Add record type and field decl to global summary. */ > >> >> > + function_pointer_type pair; > >> >> > + pair.record = base_t; > >> >> > + pair.field = field; > >> >> > + cgraph_node *node = cgraph_node::get (possible_decl); > >> >> > + > >> >> > + /* This is a candidate for optimization. */ > >> >> > + if (dump_file) > >> >> > + { > >> >> > + cgraph_node *orig = cgraph_node::get (cfun->decl); > >> >> > + fprintf (dump_file, "Candidate found in %s:\n", > orig->name ()); > >> >> > + print_gimple_stmt (dump_file, stmt, dump_flags); > >> >> > + } > >> >> > + > >> >> > + fpas->add_assignment (pair, node); > >> >> > + } > >> >> > + > >> >> > + virtual void walk_gcall (cgraph_node *cnode, gcall *stmt, void > *data) > >> >> > + { > >> >> > + (void)cnode; > >> >> > + > >> >> > + if (dump_file) > >> >> > + fprintf (dump_file, "%s: Entering.\n", __func__); > >> >> > + > >> >> > + function_pointer_type_assignments *fpas > >> >> > + = (function_pointer_type_assignments*) data; > >> >> > + > >> >> > + gcc_assert (stmt); > >> >> > + tree lhs = gimple_call_lhs (stmt); > >> >> > + if (!lhs) > >> >> > + return; > >> >> > + > >> >> > + tree lhs_t = TREE_TYPE (lhs); > >> >> > + /* We are only interested in function pointers. */ > >> >> > + if (TREE_CODE (lhs_t) != POINTER_TYPE) > >> >> > + return; > >> >> > + if (TREE_CODE (TREE_TYPE (lhs_t)) != FUNCTION_TYPE) > >> >> > + return; > >> >> > + > >> >> > + /* We only care about function pointers assigned to fields. > >> >> > + So we look for COMPONENT_REF. */ > >> >> > + const enum tree_code code = TREE_CODE (lhs); > >> >> > + if (code != COMPONENT_REF) > >> >> > + return; > >> >> > + > >> >> > + /* We either have a record or a pointer to a record. */ > >> >> > + tree base = TREE_OPERAND (lhs, 0); > >> >> > + tree base_t = TREE_TYPE (base); > >> >> > + if (TREE_CODE (base_t) != POINTER_TYPE) > >> >> > + return; > >> >> > + base_t = TREE_TYPE (base_t); > >> >> > + if (TREE_CODE (base_t) != RECORD_TYPE) > >> >> > + return; > >> >> > + if (!TYPE_P (base_t)) > >> >> > + return; > >> >> > + > >> >> > + tree field = TREE_OPERAND (lhs, 1); > >> >> > + > >> >> > + /* Add record type and field decl to global summary. */ > >> >> > + function_pointer_type pair; > >> >> > + pair.record = base_t; > >> >> > + pair.field = field; > >> >> > + > >> >> > + /* This is a reason to not optimize this pointer. */ > >> >> > + if (dump_file) > >> >> > + { > >> >> > + cgraph_node *orig = cgraph_node::get (cfun->decl); > >> >> > + fprintf (dump_file, "Counter-candidate found in %s:\n", > orig->name ()); > >> >> > + print_gimple_stmt (dump_file, stmt, dump_flags); > >> >> > + } > >> >> > + > >> >> > + fpas->add_assignment (pair, NULL); > >> >> > + } > >> >> > +}; > >> >> > + > >> >> > +/* Globals (prefixed by '_'). */ > >> >> > +static function_pointer_type_assignments > *_function_pointer_type_assignments; > >> >> > +static indirect_call_summary *_indirect_call_summaries; > >> >> > +static struct cgraph_node_hook_list *_cgraph_removal_hook_holder; > >> >> > + > >> >> > +/* Function updates our global summary. */ > >> >> > + > >> >> > +static void > >> >> > +remove_cgraph_callback (cgraph_node *node, void *data > ATTRIBUTE_UNUSED) > >> >> > +{ > >> >> > + if (dump_file) > >> >> > + fprintf (dump_file, "%s: node removal: %s\n", __func__, > node->name ()); > >> >> > + _function_pointer_type_assignments->remove (node); > >> >> > +} > >> >> > + > >> >> > +/* Register notification callbacks. */ > >> >> > + > >> >> > +static void > >> >> > +guarded_deref_register_cgraph_hooks (void) > >> >> > +{ > >> >> > + _cgraph_removal_hook_holder > >> >> > + = symtab->add_cgraph_removal_hook (&remove_cgraph_callback, > NULL); > >> >> > +} > >> >> > + > >> >> > +/* Unregister notification callbacks. */ > >> >> > + > >> >> > +static void > >> >> > +guarded_deref_unregister_cgraph_hooks (void) > >> >> > +{ > >> >> > + if (_cgraph_removal_hook_holder) > >> >> > + symtab->remove_cgraph_removal_hook > (_cgraph_removal_hook_holder); > >> >> > + _cgraph_removal_hook_holder = NULL; > >> >> > +} > >> >> > + > >> >> > +static void > >> >> > +guarded_deref_find_indirect (struct cgraph_node *node, > >> >> > + indirect_call_summary *ics) > >> >> > +{ > >> >> > + if (!node || node->inlined_to || !node->has_gimple_body_p ()) > >> >> > + return; > >> >> > + > >> >> > + for (cgraph_edge *e = node->indirect_calls; e; e = > e->next_callee) > >> >> > + { > >> >> > + gimple *stmt = e->call_stmt; > >> >> > + if (gimple_code (stmt) != GIMPLE_CALL) > >> >> > + continue; > >> >> > + > >> >> > + gcall *call_stmt = dyn_cast (stmt); > >> >> > + tree target = gimple_call_fn (call_stmt); > >> >> > + if (!target) > >> >> > + continue; > >> >> > + > >> >> > + if (TREE_CODE (target) != SSA_NAME) > >> >> > + continue; > >> >> > + > >> >> > + gimple *def = SSA_NAME_DEF_STMT (target); > >> >> > + > >> >> > + if (!gimple_assign_load_p (def)) > >> >> > + continue; > >> >> > + > >> >> > + const enum gimple_rhs_class gclass = > gimple_assign_rhs_class (def); > >> >> > + const bool valid = gclass == GIMPLE_UNARY_RHS || gclass == > GIMPLE_SINGLE_RHS; > >> >> > + if (!valid) > >> >> > + continue; > >> >> > + > >> >> > + tree rhs = gimple_assign_rhs1 (def); > >> >> > + const enum tree_code code = TREE_CODE (rhs); > >> >> > + bool is_load = COMPONENT_REF == code; > >> >> > + if (!is_load) > >> >> > + continue; > >> >> > + > >> >> > + tree base = TREE_OPERAND (rhs, 0); > >> >> > + tree field = TREE_OPERAND (rhs, 1); > >> >> > + if (RECORD_TYPE != TREE_CODE (TREE_TYPE (base))) > >> >> > + continue; > >> >> > + > >> >> > + function_pointer_type *fpt = ics->get_create (e); > >> >> > + fpt->record = TREE_TYPE (base); > >> >> > + fpt->field = field; > >> >> > + } > >> >> > +} > >> >> > + > >> >> > +static void > >> >> > +guarded_deref_generate_summary (void) > >> >> > +{ > >> >> > + if (dump_file) > >> >> > + fprintf (dump_file, "%s: Entering.\n", __func__); > >> >> > + > >> >> > + /* Allocate globals. */ > >> >> > + _function_pointer_type_assignments = new > function_pointer_type_assignments; > >> >> > + _indirect_call_summaries = new indirect_call_summary (symtab); > >> >> > + > >> >> > + /* First collect all function pointer assignments. */ > >> >> > + gimple_assignment_collector collector; > >> >> > + collector.walk (_function_pointer_type_assignments); > >> >> > + > >> >> > + /* Now collect all indirect calls. */ > >> >> > + cgraph_node *cnode = NULL; > >> >> > + FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (cnode) > >> >> > + { > >> >> > + guarded_deref_find_indirect (cnode, > _indirect_call_summaries); > >> >> > + } > >> >> > + > >> >> > + /* Print collected information. */ > >> >> > + _function_pointer_type_assignments->print (); > >> >> > + _indirect_call_summaries-> print (); > >> >> > + > >> >> > + /* Register hooks for cgraph changes in other passes. */ > >> >> > + guarded_deref_register_cgraph_hooks (); > >> >> > +} > >> >> > + > >> >> > +static void > >> >> > +guarded_deref_write_summary (void) > >> >> > +{ > >> >> > + if (dump_file) > >> >> > + fprintf (dump_file, "%s: Entering.\n", __func__); > >> >> > + > >> >> > + /* Only run if we are in a sane state. */ > >> >> > + if (!_function_pointer_type_assignments || > !_indirect_call_summaries) > >> >> > + return; > >> >> > + > >> >> > + /* Print collected information. */ > >> >> > + _function_pointer_type_assignments->print (); > >> >> > + _indirect_call_summaries-> print (); > >> >> > + > >> >> > + /* Unregister cgraph change hooks. */ > >> >> > + guarded_deref_unregister_cgraph_hooks (); > >> >> > + > >> >> > + /* Create an output block to write out information into. */ > >> >> > + struct output_block *ob = create_output_block > (LTO_section_ipa_guarded_deref); > >> >> > + > >> >> > + /* Get the cgraph_node encoder. */ > >> >> > + lto_symtab_encoder_t encoder = > ob->decl_state->symtab_node_encoder; > >> >> > + > >> >> > + /* Write collected function pointer assignments to the OB. */ > >> >> > + _function_pointer_type_assignments->serialize (ob, encoder); > >> >> > + > >> >> > + /* Write edge summaries. */ > >> >> > + _indirect_call_summaries->serialize (ob, encoder); > >> >> > + > >> >> > + /* Delete the information in memory. */ > >> >> > + delete _function_pointer_type_assignments; > >> >> > + _function_pointer_type_assignments = NULL; > >> >> > + delete _indirect_call_summaries; > >> >> > + _indirect_call_summaries = NULL; > >> >> > + > >> >> > + /* Write the contents of the output block into the instruction > stream. */ > >> >> > + produce_asm (ob, NULL); > >> >> > + > >> >> > + /* Now destroy the output block. */ > >> >> > + destroy_output_block (ob); > >> >> > +} > >> >> > + > >> >> > +static void > >> >> > +guarded_deref_read_summary (void) > >> >> > +{ > >> >> > + if (dump_file) > >> >> > + fprintf (dump_file, "%s: Entering.\n", __func__); > >> >> > + > >> >> > + if (_indirect_call_summaries || > _function_pointer_type_assignments) > >> >> > + return; > >> >> > + > >> >> > + /* Allocate globals. */ > >> >> > + _indirect_call_summaries = new indirect_call_summary (symtab); > >> >> > + _function_pointer_type_assignments = new > function_pointer_type_assignments; > >> >> > + > >> >> > + struct lto_file_decl_data **file_data_vec = > lto_get_file_decl_data (); > >> >> > + struct lto_file_decl_data *file_data; > >> >> > + unsigned int j = 0; > >> >> > + while ((file_data = file_data_vec[j++])) > >> >> > + { > >> >> > + size_t len; > >> >> > + const char *data = lto_get_summary_section_data (file_data, > >> >> > + > LTO_section_ipa_guarded_deref, > >> >> > + &len); > >> >> > + if (!data) > >> >> > + continue; > >> >> > + > >> >> > + const struct lto_function_header *header > >> >> > + = (const struct lto_function_header*) data; > >> >> > + > >> >> > + const int cfg_offset = sizeof (*header); > >> >> > + const int main_offset = cfg_offset + header->cfg_size; > >> >> > + const int string_offset = main_offset + header->main_size; > >> >> > + class data_in *data_in; > >> >> > + > >> >> > + lto_input_block ib ((const char *) data + main_offset, > >> >> > + header->main_size, > file_data->mode_table); > >> >> > + data_in = lto_data_in_create (file_data, > >> >> > + (const char *) data + > string_offset, > >> >> > + header->string_size, vNULL); > >> >> > + > >> >> > + lto_symtab_encoder_t encoder = > file_data->symtab_node_encoder; > >> >> > + > >> >> > + /* Read collected function pointer assignments from LTO > stream. */ > >> >> > + _function_pointer_type_assignments->deserialize (ib, > data_in, encoder); > >> >> > + > >> >> > + /* Read collected indirect call summary from LTO stream. > */ > >> >> > + _indirect_call_summaries->deserialize (ib, data_in, > encoder); > >> >> > + > >> >> > + lto_free_section_data (file_data, > LTO_section_ipa_guarded_deref, NULL, > >> >> > + data, len); > >> >> > + lto_data_in_delete (data_in); > >> >> > + } > >> >> > + > >> >> > + /* Print collected information. */ > >> >> > + _function_pointer_type_assignments->print (); > >> >> > + _indirect_call_summaries-> print (); > >> >> > + > >> >> > + /* Register hooks for cgraph changes in other passes. */ > >> >> > + guarded_deref_register_cgraph_hooks (); > >> >> > +} > >> >> > + > >> >> > +static unsigned int > >> >> > +guarded_deref_execute (void) > >> >> > +{ > >> >> > + if (dump_file) > >> >> > + fprintf (dump_file, "%s: Entering.\n", __func__); > >> >> > + > >> >> > + if (!_function_pointer_type_assignments > >> >> > + || !_indirect_call_summaries) > >> >> > + return 0; > >> >> > + > >> >> > + /* Unregister cgraph change hooks. */ > >> >> > + guarded_deref_unregister_cgraph_hooks (); > >> >> > + > >> >> > + /* Print collected information. */ > >> >> > + _function_pointer_type_assignments->print (); > >> >> > + _indirect_call_summaries-> print (); > >> >> > + > >> >> > + if (dump_file) > >> >> > + fprintf (dump_file, "%s: Starting propagation.\n", __func__); > >> >> > + > >> >> > + cgraph_node *cnode = NULL; > >> >> > + FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (cnode) > >> >> > + { > >> >> > + if (cnode->inlined_to) > >> >> > + continue; > >> >> > + > >> >> > + for (cgraph_edge *e = cnode->indirect_calls; e; e = > e->next_callee) > >> >> > + { > >> >> > + /* Get the function pointer type for the edge (if any). > */ > >> >> > + function_pointer_type *fpt = > _indirect_call_summaries->get (e); > >> >> > + if (!fpt || !fpt->record || !fpt->field) > >> >> > + continue; > >> >> > + > >> >> > + if (dump_file) > >> >> > + { > >> >> > + fprintf (dump_file, "looking for...:"); > >> >> > + print_generic_expr (dump_file, fpt->record, > TDF_NONE); > >> >> > + fprintf (dump_file, " "); > >> >> > + print_generic_expr (dump_file, fpt->field, TDF_NONE); > >> >> > + fprintf (dump_file, "\n"); > >> >> > + } > >> >> > + > >> >> > + /* Now get the call target (if any). */ > >> >> > + cgraph_node *target = > _function_pointer_type_assignments->get_target (*fpt); > >> >> > + if (!target || !target->decl) > >> >> > + continue; > >> >> > + > >> >> > + if (dump_file) > >> >> > + { > >> >> > + fprintf (dump_file, > >> >> > + "Replacing indirect call in %s by " > >> >> > + "speculative direct call to %s\n", > >> >> > + e->caller->name (), target->name ()); > >> >> > + } > >> >> > + > >> >> > + /* Convert the indirect call to a direct (speculative) > call. */ > >> >> > + ipa_make_edge_direct_to_target (e, target->decl, true); > >> >> > + > >> >> > + /* Update the function summaries. */ > >> >> > + ipa_update_overall_fn_summary (cnode); > >> >> > + } > >> >> > + } > >> >> > + > >> >> > + if (dump_file) > >> >> > + fprintf (dump_file, "%s: Finished propagation.\n", __func__); > >> >> > + > >> >> > + return 0; > >> >> > +} > >> >> > + > >> >> > +namespace { > >> >> > + > >> >> > +const pass_data pass_data_ipa_guarded_deref = > >> >> > +{ > >> >> > + IPA_PASS, /* type */ > >> >> > + "guarded-deref", /* name */ > >> >> > + OPTGROUP_NONE, /* optinfo_flags */ > >> >> > + TV_IPA_GUARDED_DEREF, /* tv_id */ > >> >> > + 0, /* properties_required */ > >> >> > + 0, /* properties_provided */ > >> >> > + 0, /* properties_destroyed */ > >> >> > + 0, /* todo_flags_start */ > >> >> > + 0, /* todo_flags_finish */ > >> >> > +}; > >> >> > + > >> >> > +class pass_ipa_guarded_deref : public ipa_opt_pass_d > >> >> > +{ > >> >> > +public: > >> >> > + pass_ipa_guarded_deref (gcc::context *ctxt) > >> >> > + : ipa_opt_pass_d (pass_data_ipa_guarded_deref, ctxt, > >> >> > + guarded_deref_generate_summary, /* > generate_summary */ > >> >> > + guarded_deref_write_summary, /* > write_summary */ > >> >> > + guarded_deref_read_summary, /* read_summary > */ > >> >> > + NULL, /* write_optimization_summary */ > >> >> > + NULL, /* read_optimization_summary */ > >> >> > + NULL, /* stmt_fixup */ > >> >> > + 0, /* function_transform_todo_flags_start */ > >> >> > + NULL, /* function_transform */ > >> >> > + NULL) /* variable_transform */ > >> >> > + {} > >> >> > + > >> >> > + /* opt_pass methods: */ > >> >> > + bool gate (function *) final override > >> >> > + { > >> >> > + return ((in_lto_p || flag_lto) && flag_ipa_guarded_deref); > >> >> > + } > >> >> > + > >> >> > + unsigned int execute (function *) final override > >> >> > + { > >> >> > + return guarded_deref_execute (); > >> >> > + } > >> >> > + > >> >> > +}; // class pass_ipa_guarded_deref > >> >> > + > >> >> > +} // anon namespace > >> >> > + > >> >> > +ipa_opt_pass_d * > >> >> > +make_pass_ipa_guarded_deref (gcc::context *ctxt) > >> >> > +{ > >> >> > + return new pass_ipa_guarded_deref (ctxt); > >> >> > +} > >> >> > diff --git a/gcc/lto-section-in.cc b/gcc/lto-section-in.cc > >> >> > index ba87c727670..22f6b66a291 100644 > >> >> > --- a/gcc/lto-section-in.cc > >> >> > +++ b/gcc/lto-section-in.cc > >> >> > @@ -57,6 +57,7 @@ const char > *lto_section_name[LTO_N_SECTION_TYPES] = > >> >> > "ipa_sra", > >> >> > "odr_types", > >> >> > "ipa_modref", > >> >> > + "ipa_guarded_deref", > >> >> > }; > >> >> > > >> >> > /* Hooks so that the ipa passes can call into the lto front end > to get > >> >> > diff --git a/gcc/lto-streamer.h b/gcc/lto-streamer.h > >> >> > index 2e3abd97959..744e8738376 100644 > >> >> > --- a/gcc/lto-streamer.h > >> >> > +++ b/gcc/lto-streamer.h > >> >> > @@ -229,6 +229,7 @@ enum lto_section_type > >> >> > LTO_section_ipa_sra, > >> >> > LTO_section_odr_types, > >> >> > LTO_section_ipa_modref, > >> >> > + LTO_section_ipa_guarded_deref, > >> >> > LTO_N_SECTION_TYPES /* Must be last. */ > >> >> > }; > >> >> > > >> >> > diff --git a/gcc/passes.def b/gcc/passes.def > >> >> > index 193b5794749..60c029e0515 100644 > >> >> > --- a/gcc/passes.def > >> >> > +++ b/gcc/passes.def > >> >> > @@ -154,6 +154,7 @@ along with GCC; see the file COPYING3. If not > see > >> >> > NEXT_PASS (pass_ipa_whole_program_visibility); > >> >> > NEXT_PASS (pass_ipa_profile); > >> >> > NEXT_PASS (pass_ipa_icf); > >> >> > + NEXT_PASS (pass_ipa_guarded_deref); > >> >> > NEXT_PASS (pass_ipa_devirt); > >> >> > NEXT_PASS (pass_ipa_cp); > >> >> > NEXT_PASS (pass_ipa_sra); > >> >> > diff --git a/gcc/timevar.def b/gcc/timevar.def > >> >> > index 63d9b005180..38fd7798768 100644 > >> >> > --- a/gcc/timevar.def > >> >> > +++ b/gcc/timevar.def > >> >> > @@ -72,6 +72,7 @@ DEFTIMEVAR (TV_CGRAPH_FUNC_EXPANSION , > "callgraph functions expansion") > >> >> > DEFTIMEVAR (TV_CGRAPH_IPA_PASSES , "callgraph ipa passes") > >> >> > DEFTIMEVAR (TV_IPA_ODR , "ipa ODR types") > >> >> > DEFTIMEVAR (TV_IPA_FNSUMMARY , "ipa function summary") > >> >> > +DEFTIMEVAR (TV_IPA_GUARDED_DEREF , "ipa guarded deref") > >> >> > DEFTIMEVAR (TV_IPA_UNREACHABLE , "ipa dead code removal") > >> >> > DEFTIMEVAR (TV_IPA_INHERITANCE , "ipa inheritance graph") > >> >> > DEFTIMEVAR (TV_IPA_VIRTUAL_CALL , "ipa virtual call target") > >> >> > diff --git a/gcc/tree-pass.h b/gcc/tree-pass.h > >> >> > index 8480d41384b..6cc200bd83e 100644 > >> >> > --- a/gcc/tree-pass.h > >> >> > +++ b/gcc/tree-pass.h > >> >> > @@ -525,6 +525,7 @@ extern ipa_opt_pass_d *make_pass_ipa_inline > (gcc::context *ctxt); > >> >> > extern simple_ipa_opt_pass *make_pass_ipa_free_lang_data > (gcc::context *ctxt); > >> >> > extern simple_ipa_opt_pass *make_pass_ipa_free_fn_summary > (gcc::context *ctxt); > >> >> > extern ipa_opt_pass_d *make_pass_ipa_cp (gcc::context *ctxt); > >> >> > +extern ipa_opt_pass_d *make_pass_ipa_guarded_deref (gcc::context > *ctxt); > >> >> > extern ipa_opt_pass_d *make_pass_ipa_sra (gcc::context *ctxt); > >> >> > extern ipa_opt_pass_d *make_pass_ipa_icf (gcc::context *ctxt); > >> >> > extern ipa_opt_pass_d *make_pass_ipa_devirt (gcc::context *ctxt); > >> >> > -- > >> >> > 2.38.1 > >> >> > >