On Wed, Nov 11, 2020 at 03:14:59AM -0800, Erick Ochoa wrote: > > Using the Dead Field Analysis, Dead Field Elimination > automatically transforms gimple to eliminate fields that > are never read. > > 2020-11-04 Erick Ochoa <erick.oc...@theobroma-systems.com> > > * gcc/Makefile.in: add file to list of sources > * gcc/ipa-dfe.c: New > * gcc/ipa-dfe.h: Same > * gcc/ipa-type-escape-analysis.h: Export code used in dfe. > * gcc/ipa-type-escape-analysis.c: Call transformation
Just random general nits, not a review. The gcc/ prefix shouldn't be in the filenames, paths are relative to the ChangeLog file into which it goes and gcc/ directory has a ChangeLog. All entries should start with a capital letter, so Add above, and all should end with a period (missing in all but one place). > --- > gcc/Makefile.in | 1 + > gcc/ipa-dfe.c | 1284 ++++++++++++++++++++++++++++++++ > gcc/ipa-dfe.h | 247 ++++++ > gcc/ipa-type-escape-analysis.c | 22 +- > gcc/ipa-type-escape-analysis.h | 10 + > 5 files changed, 1554 insertions(+), 10 deletions(-) > create mode 100644 gcc/ipa-dfe.c > create mode 100644 gcc/ipa-dfe.h > > diff --git a/gcc/Makefile.in b/gcc/Makefile.in > index 8b18c9217a2..8ef6047870b 100644 > --- a/gcc/Makefile.in > +++ b/gcc/Makefile.in > @@ -1416,6 +1416,7 @@ OBJS = \ > init-regs.o \ > internal-fn.o \ > ipa-type-escape-analysis.o \ > + ipa-dfe.o \ > ipa-cp.o \ > ipa-sra.o \ > ipa-devirt.o \ > diff --git a/gcc/ipa-dfe.c b/gcc/ipa-dfe.c > new file mode 100644 > index 00000000000..5ba68332ad2 > --- /dev/null > +++ b/gcc/ipa-dfe.c > @@ -0,0 +1,1284 @@ > +/* IPA Type Escape Analysis and Dead Field Elimination > + Copyright (C) 2019-2020 Free Software Foundation, Inc. > + > + Contributed by Erick Ochoa <erick.oc...@theobroma-systems.com> > + > +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 > +<http://www.gnu.org/licenses/>. */ > + > +/* Interprocedural dead field elimination (IPA-DFE) > + > + The goal of this transformation is to > + > + 1) Create new types to replace RECORD_TYPEs which hold dead fields. > + 2) Substitute instances of old RECORD_TYPEs for new RECORD_TYPEs. > + 3) Substitute instances of old FIELD_DECLs for new FIELD_DECLs. > + 4) Fix some instances of pointer arithmetic. > + 5) Relayout where needed. > + > + First stage - DFA > + ================= > + > + Use DFA to compute the set of FIELD_DECLs which can be deleted. > + > + Second stage - Reconstruct Types > + ================================ > + > + This stage is done by two family of classes, the SpecificTypeCollector > + and the TypeReconstructor. > + > + The SpecificTypeCollector collects all TYPE_P trees which point to > + RECORD_TYPE trees returned by DFA. The TypeReconstructor will create > + new RECORD_TYPE trees and new TYPE_P trees replacing the old RECORD_TYPE > + trees with the new RECORD_TYPE trees. > + > + Third stage - Substitute Types and Relayout > + =========================================== > + > + This stage is handled by ExprRewriter and GimpleRewriter. > + Some pointer arithmetic is fixed here to take into account those > eliminated > + FIELD_DECLS. > + */ > + > +#include "config.h" > + > +#include <map> > +#include <set> > +#include <vector> > +#include <stack> > +#include <string> We really do not want to use STL in GCC sources that much, we have our own vectors and hash_sets/maps. If something is still needed after that, the standard way to include STL header is define INCLUDE_ALGORITHM etc. macros before including system.h. > + > +#include "system.h" > + TypeStringifier stringifier; GCC is not a CamelCase shop, so types etc. should use lower-case only and underscores instead. This is everywhere in the patch. > + > + // Here we are just placing the types of interest in a set. > + for (std::map<tree, field_offsets_t>::const_iterator i > + = record_field_offset_map.begin (), > + e = record_field_offset_map.end (); > + i != e; ++i) This should just use hash_map. > + for (std::set<tree>::const_iterator i = non_escaping.begin (), > + e = non_escaping.end (); > + i != e; ++i) > + { > + tree type = *i; > + specifier.walk (type); > + } > + > + // These are all the types which need modifications. > + std::set<tree> to_modify = specifier.get_set (); And hash_set. Also note that code-generation from hash table iterations should be generally avoided, because the exact iteration order can change between different runs (or e.g. between cross-compilers from different hosts etc.). > + tree o_record = i->first; > + std::string o_name = stringifier.stringify (o_record); > + log ("original: %s\n", o_name.c_str ()); > + tree r_record = i->second; > + std::string r_name > + = r_record ? stringifier.stringify (r_record) : std::string (""); > + log ("modified: %s\n", r_name.c_str ()); This should use the various diagnostic routines rather than std::string etc. > +static tree > +get_new_identifier (tree type) > +{ > + const char *identifier = TypeStringifier::get_type_identifier > (type).c_str (); > + const bool is_new_type = strstr (identifier, "reorg"); reorg substring can appear in any user type name, can't it? Jakub
