/* Translation of ISL AST to Gimple.
   Copyright (C) 2014 Free Software Foundation, Inc.
   Contributed by Roman Gareev <gareevroman@gmail.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/>.  */

#include "config.h"

#ifdef HAVE_cloog
#include <isl/set.h>
#include <isl/map.h>
#include <isl/union_map.h>
#include <isl/ast_build.h>
#endif

#include "system.h"
#include "coretypes.h"
#include "tree.h"
#include "basic-block.h"
#include "tree-ssa-alias.h"
#include "internal-fn.h"
#include "gimple-expr.h"
#include "is-a.h"
#include "gimple.h"
#include "gimple-iterator.h"
#include "tree-ssa-loop.h"
#include "tree-pass.h"
#include "cfgloop.h"
#include "tree-data-ref.h"
#include "sese.h"

#ifdef HAVE_cloog
#include "graphite-poly.h"
#include "graphite-isl-ast-to-gimple.h"

/* This flag is set when an error occurred during the translation of
   ISL AST to Gimple.  */

static bool graphite_regenerate_error;

/* Prints NODE to FILE.  */

void
print_isl_ast_node (FILE *file, __isl_keep isl_ast_node *node, 
		    __isl_keep isl_ctx *ctx)
{
  isl_printer *prn = isl_printer_to_file (ctx, file);
  prn = isl_printer_set_output_format (prn, ISL_FORMAT_C);
  prn = isl_printer_print_ast_node (prn, node);
  prn = isl_printer_print_str (prn, "\n");
  isl_printer_free (prn);
}

/* Generates a build, which specifies the constraints on the parameters.  */

static isl_ast_build *
generate_isl_context (scop_p scop)
{
  isl_set *context_isl = isl_set_params (isl_set_copy (scop->context));
  return isl_ast_build_from_context (context_isl);
}

/* Generates a schedule, which specifies an order used to
   visit elements in a domain.  */

static isl_union_map *
generate_isl_schedule (scop_p scop)
{
  int i;
  poly_bb_p pbb;
  isl_union_map *schedule_isl =
    isl_union_map_empty (isl_set_get_space (scop->context));

  FOR_EACH_VEC_ELT (SCOP_BBS (scop), i, pbb)
    {
      /* Dead code elimination: when the domain of a PBB is empty,
	 don't generate code for the PBB.  */
      if (isl_set_is_empty (pbb->domain))
	continue;

      isl_map *bb_schedule = isl_map_copy (pbb->transformed);
      bb_schedule = isl_map_intersect_domain (bb_schedule,
					      isl_set_copy (pbb->domain));
      schedule_isl =
        isl_union_map_union (schedule_isl,
			     isl_union_map_from_map (bb_schedule));
    }
  return schedule_isl;
}

static isl_ast_node *
scop_to_isl_ast (scop_p scop)
{
  isl_union_map *schedule_isl = generate_isl_schedule (scop);
  isl_ast_build *context_isl = generate_isl_context (scop);
  isl_ast_node *ast_isl = isl_ast_build_ast_from_schedule (context_isl,
							   schedule_isl);
  isl_ast_build_free (context_isl);
  return ast_isl;
}

/* GIMPLE Loop Generator: generates loops from STMT in GIMPLE form for
   the given SCOP.  Return true if code generation succeeded.

   FIXME: This is not yet a full implementation of the code generator
          with ISL ASTs. Generation of GIMPLE code is have to be added.  */

bool
graphite_regenerate_ast_isl (scop_p scop)
{
  timevar_push (TV_GRAPHITE_CODE_GEN);
  graphite_regenerate_error = false;
  isl_ast_node *root_node = scop_to_isl_ast (scop);
  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "\nISL AST generated by ISL: \n");
      print_isl_ast_node (dump_file, root_node, scop->ctx);
    }
  isl_ast_node_free (root_node);
  timevar_pop (TV_GRAPHITE_CODE_GEN);
  return !graphite_regenerate_error;
}
#endif