Add rtl-ssa

This patch adds the RTL SSA infrastructure itself.  The following
fwprop.c patch will make use of it.

gcc/
	* configure.ac: Add rtl-ssa to the list of dependence directories.
	* configure: Regenerate.
	* Makefile.in (rtl-ssa-warn): New variable.
	(OBJS): Add the rtl-ssa object files.
	* emit-rtl.h (rtl_data::ssa): New field.
	* rtl-ssa.h: New file.
	* system.h: Include <functional> when INCLUDE_FUNCTIONAL is defined.
	* rtl-ssa/access-utils.h: Likewise.
	* rtl-ssa/accesses.h: New file.
	* rtl-ssa/accesses.cc: Likewise.
	* rtl-ssa/blocks.h: New file.
	* rtl-ssa/blocks.cc: Likewise.
	* rtl-ssa/change-utils.h: Likewise.
	* rtl-ssa/changes.h: New file.
	* rtl-ssa/changes.cc: Likewise.
	* rtl-ssa/functions.h: New file.
	* rtl-ssa/functions.cc: Likewise.
	* rtl-ssa/insn-utils.h: Likewise.
	* rtl-ssa/insns.h: New file.
	* rtl-ssa/insns.cc: Likewise.
	* rtl-ssa/internals.inl: Likewise.
	* rtl-ssa/is-a.inl: Likewise.
	* rtl-ssa/member-fns.inl: Likewise.
	* rtl-ssa/movement.h: Likewise.

gcc/Makefile.in

@@ -207,6 +207,7 @@ VALGRIND_DRIVER_DEFINES = @valgrind_path_defines@
 # This is how we control whether or not the additional warnings are applied.
 .-warn = $(STRICT_WARN)
 build-warn = $(STRICT_WARN)
+rtl-ssa-warn = $(STRICT_WARN)
 GCC_WARN_CFLAGS = $(LOOSE_WARN) $(C_LOOSE_WARN) $($(@D)-warn) $(if $(filter-out $(STRICT_WARN),$($(@D)-warn)),,$(C_STRICT_WARN)) $(NOCOMMON_FLAG) $($@-warn)
 GCC_WARN_CXXFLAGS = $(LOOSE_WARN) $($(@D)-warn) $(NOCOMMON_FLAG) $($@-warn)
 
@@ -1525,6 +1526,11 @@ OBJS = \
 	reorg.o \
 	resource.o \
 	rtl-error.o \
+	rtl-ssa/accesses.o \
+	rtl-ssa/blocks.o \
+	rtl-ssa/changes.o \
+	rtl-ssa/functions.o \
+	rtl-ssa/insns.o \
 	rtl-tests.o \
 	rtl.o \
 	rtlhash.o \

gcc/configure

@@ -33265,7 +33265,7 @@ $as_echo "$as_me: executing $ac_file commands" >&6;}
     "depdir":C) $SHELL $ac_aux_dir/mkinstalldirs $DEPDIR ;;
     "gccdepdir":C)
   ${CONFIG_SHELL-/bin/sh} $ac_aux_dir/mkinstalldirs build/$DEPDIR
-  for lang in $subdirs c-family common analyzer
+  for lang in $subdirs c-family common analyzer rtl-ssa
   do
       ${CONFIG_SHELL-/bin/sh} $ac_aux_dir/mkinstalldirs $lang/$DEPDIR
   done ;;

gcc/configure.ac

@@ -1242,7 +1242,7 @@ AC_CHECK_HEADERS(ext/hash_map)
 ZW_CREATE_DEPDIR
 AC_CONFIG_COMMANDS([gccdepdir],[
   ${CONFIG_SHELL-/bin/sh} $ac_aux_dir/mkinstalldirs build/$DEPDIR
-  for lang in $subdirs c-family common analyzer
+  for lang in $subdirs c-family common analyzer rtl-ssa
   do
       ${CONFIG_SHELL-/bin/sh} $ac_aux_dir/mkinstalldirs $lang/$DEPDIR
   done], [subdirs="$subdirs" ac_aux_dir=$ac_aux_dir DEPDIR=$DEPDIR])

gcc/emit-rtl.h

@@ -23,6 +23,7 @@ along with GCC; see the file COPYING3.  If not see
 class temp_slot;
 typedef class temp_slot *temp_slot_p;
 class predefined_function_abi;
+namespace rtl_ssa { class function_info; }
 
 /* Information mainlined about RTL representation of incoming arguments.  */
 struct GTY(()) incoming_args {
@@ -73,6 +74,8 @@ struct GTY(()) rtl_data {
      different ABIs.  */
   const predefined_function_abi *GTY((skip)) abi;
 
+  rtl_ssa::function_info *GTY((skip)) ssa;
+
   /* For function.c  */
 
   /* # of bytes of outgoing arguments.  If ACCUMULATE_OUTGOING_ARGS is

gcc/rtl-ssa.h

@@ -0,0 +1,71 @@
+// On-the-side RTL SSA representation                               -*- C++ -*-
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// 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/>.
+
+#ifndef GCC_RTL_SSA_H
+#define GCC_RTL_SSA_H 1
+
+// This is an aggregation header file.  This means it should contain only
+// other include files.
+
+#if 0
+// Files that use this one should first have:
+#define INCLUDE_ALGORITHM
+#define INCLUDE_FUNCTIONAL
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "backend.h"
+#include "rtl.h"
+#include "df.h"
+#endif
+
+// Needed by splay-tree-utils.h and directly by rtl-ssa.
+#include "pretty-print.h"
+
+// Needed directly by recog.h.
+#include "insn-config.h"
+
+// Needed directly by rtl-ssa.
+#include "splay-tree-utils.h"
+#include "recog.h"
+#include "regs.h"
+#include "function-abi.h"
+#include "obstack-utils.h"
+#include "mux-utils.h"
+#include "rtlanal.h"
+
+// Provides the global crtl->ssa.
+#include "tm_p.h"
+#include "memmodel.h"
+#include "emit-rtl.h"
+
+// The rtl-ssa files themselves.
+#include "rtl-ssa/accesses.h"
+#include "rtl-ssa/insns.h"
+#include "rtl-ssa/blocks.h"
+#include "rtl-ssa/changes.h"
+#include "rtl-ssa/functions.h"
+#include "rtl-ssa/is-a.inl"
+#include "rtl-ssa/access-utils.h"
+#include "rtl-ssa/insn-utils.h"
+#include "rtl-ssa/movement.h"
+#include "rtl-ssa/change-utils.h"
+#include "rtl-ssa/member-fns.inl"
+
+#endif