Preserve the original program while using graphite.

Earlier, graphite used to translate portions of the original program after
scop-detection in order to represent the SCoP into polyhedral model.  This was
required because each basic block was represented as independent basic block in
the polyhedral model. So all the cross-basic-block dependencies were translated
out-of-ssa.

With this patch those dependencies are also exposed to the ISL, so there is no
need to modify the original structure of the program.

After this patch we should be able to enable graphite at some default
optimization level.

Highlights:
Remove cross bb scalar to array translation
For reductions, add support for more than just INT_CST
Early bailout on codegen.
Verify loop-closed ssa structure during copy of renames
The uses of exprs should come from bb which dominates the bb
Collect the init value of close phi in loop-guard
Do not follow vuses for close-phi, postpone loop-close phi until the
    corresponding loop-phi is processed
Bail out if no bb found to place cond/loop -phis
Move insertion of liveouts at the end of codegen
Insert loop-phis in the loop-header.

This patch passes regtest and bootstrap with BOOT_CFLAGS='-O2 -fgraphite-identity -floop-nest-optimize'

2015-11-11  Aditya Kumar  <aditya.k7@samsung.com>
      Sebastian Pop  <s.pop@samsung.com>

	* graphite-isl-ast-to-gimple.c (class translate_isl_ast_to_gimple):
	  New member codegen_error
	(translate_isl_ast_for_loop): Remove call to single_succ_edge and early return.
	(translate_isl_ast_node_user): Early return in case of error.
	(translate_isl_ast_to_gimple::translate_isl_ast): Same.
	(translate_isl_ast_to_gimple::translate_pending_phi_nodes): New.
	(add_parameters_to_ivs_params): Remove macro.
	(graphite_regenerate_ast_isl): Add if_region pointer to region.
	* graphite-poly.c (new_poly_dr): Remove macro.
	(print_pdr): Same.
	(new_gimple_poly_bb): Same.
	(free_gimple_poly_bb): Same.
	(print_scop_params): Same.
	* graphite-poly.h (struct poly_dr): Same.
	(struct poly_bb): Add new_bb.
	(gbb_from_bb): Remove dead code.
	(pbb_from_bb): Same.
	* graphite-scop-detection.c (parameter_index_in_region_1): Same.
	(parameter_index_in_region): Same.
	(find_scop_parameters): Same.
	(build_cross_bb_scalars_def): New.
	(build_cross_bb_scalars_use): New.
	(graphite_find_cross_bb_scalar_vars): New
	(try_generate_gimple_bb): Reads and Writes.
	(build_alias_set): Move.
	(gather_bbs::before_dom_children): Gather bbs visited.
	(build_scops): call build_alias_set.
	* graphite-sese-to-poly.c (phi_arg_in_outermost_loop): Delete.
	(remove_simple_copy_phi): Delete.
	(remove_invariant_phi): Delete.
	(simple_copy_phi_p): Delete.
	(reduction_phi_p): Delete.
	(isl_id_for_dr): Remove unused param.
	(parameter_index_in_region_1): Remove macro usage.
	(set_scop_parameter_dim): Same.
	(add_param_constraints): Same.
	(add_conditions_to_constraints): Same
	(build_scop_iteration_domain): Same.
	(pdr_add_alias_set): Comment.
	(add_scalar_version_numbers): New.
	(build_poly_dr): ISL id.
	(build_scop_drs): Move.
	(build_poly_sr_1): Same.
	(insert_stmts): Remove.
	(build_poly_sr): New.
	(new_pbb_from_pbb): Delete.
	(insert_out_of_ssa_copy_on_edge): Delete.
	(create_zero_dim_array): Delete.
	(scalar_close_phi_node_p): Delete.
	(propagate_expr_outside_region): Delete.
	(rewrite_close_phi_out_of_ssa): Delete.
	(rewrite_phi_out_of_ssa): Delete.
	(rewrite_degenerate_phi): Delete.
	(rewrite_reductions_out_of_ssa): Delete.
	(rewrite_cross_bb_scalar_dependence): Delete.
	(handle_scalar_deps_crossing_scop_limits):
	(rewrite_cross_bb_scalar_deps): Delete.
	(build_poly_scop): Remove calls to out-of-ssa functions.
	* graphite.c (graphite_transform_loops): Early return in case of codegen error.
	* sese.c (debug_rename_map_1): Delete.
	(debug_rename_map): Delete.
	(sese_record_loop): Remove macro.
	(build_sese_loop_nests): Same.
	(new_sese_info): Same.
	(free_sese_info): Same.
	(sese_insert_phis_for_liveouts):
	(is_loop_closed_ssa_use): New.
	(number_of_phi_nodes): New.
	(bb_contains_loop_close_phi_nodes): New.
	(bb_contains_loop_phi_nodes): New.
	(phi_uses_name): New.
	(is_valid_rename):
	(get_rename): Add old_bb and loop_phi for more precise matching of
	exprs.
	(set_rename): Pass region.
	(later_of_the_two): New.
	(gsi_insert_earliest): New.
	(collect_all_ssa_names): New.
	(substitute_ssa_name): New.
	(rename_all_uses): New.
	(get_rename_from_scev): New.
	(rename_uses): Pass old_bb for more precise matching of exprs.
	(get_def_bb_for_const): New.
	(get_new_name): New.
	(get_loc): New.
	(get_edges): New.
	(copy_loop_phi_args): New.
	(copy_loop_phi_nodes): New.
	(get_loop_init_value): New.
	(find_init_value): New.
	(find_init_value_close_phi): New.
	(copy_loop_close_phi_args): New.
	(copy_loop_close_phi_nodes): New.
	(add_phi_arg_for_new_expr): New.
	(copy_cond_phi_args): New.
	(copy_cond_phi_nodes): New.
	(copy_phi_nodes): New.
	(should_copy_to_new_region): New.
	(set_rename_for_each_def): New.
	(graphite_copy_stmts_from_block): Early return in case of error.
	(copy_bb_and_scalar_dependences): Same.
	* sese.h (vec_find): New.
	(SESE_PARAMS): Delete.
	(SESE_LOOPS): Delete.
	(SESE_LOOP_NEST): Delete.
	(sese_contains_loop): Remove macro usage.
	(sese_nb_params): Same.
	(struct gimple_poly_bb): Added read_scalar_refs, write_scalar_refs.

Co-Authored-By: Sebastian Pop <s.pop@samsung.com>

From-SVN: r230200

1 files changed, 54 insertions, 6 deletions

diff --git a/gcc/sese.h b/gcc/sese.h
index b3d48b9..bce226a 100644
--- a/gcc/sese.h
+++ b/gcc/sese.h
@@ -22,6 +22,14 @@ along with GCC; see the file COPYING3.  If not see
 #ifndef GCC_SESE_H
 #define GCC_SESE_H
 
+typedef hash_map<basic_block, vec<basic_block> > bb_map_t;
+typedef hash_map<tree, vec<tree> > rename_map_t;
+typedef struct ifsese_s *ifsese;
+/* First phi is the new codegenerated phi second one is original phi.  */
+typedef std::pair <gphi *, gphi *> phi_rename;
+/* First edge is the init edge and second is the back edge w.r.t. a loop.  */
+typedef std::pair<edge, edge> init_back_edge_pair_t;
+
 /* A Single Entry, Single Exit region is a part of the CFG delimited
    by two edges.  */
 struct sese_l
@@ -50,6 +58,20 @@ get_exit_bb (sese_l &s)
   return s.exit->src;
 }
 
+/* Returns the index of V where ELEM can be found. -1 Otherwise.  */
+
+template<typename T>
+int
+vec_find (const vec<T> &v, const T &elem)
+{
+  int i;
+  T t;
+  FOR_EACH_VEC_ELT (v, i, t)
+    if (elem == t)
+      return i;
+  return -1;
+}
+
 /* A helper structure for bookkeeping information about a scop in graphite.  */
 typedef struct sese_info_t
 {
@@ -59,17 +81,29 @@ typedef struct sese_info_t
   /* Parameters used within the SCOP.  */
   vec<tree> params;
 
+  /* Maps an old name to one or more new names.  When there are several new
+     names, one has to select the definition corresponding to the immediate
+     dominator.  */
+  rename_map_t *rename_map;
+
   /* Loops completely contained in this SESE.  */
   bitmap loops;
   vec<loop_p> loop_nest;
 
   /* Basic blocks contained in this SESE.  */
   vec<basic_block> bbs;
-} *sese_info_p;
 
-#define SESE_PARAMS(S) (S->params)
-#define SESE_LOOPS(S) (S->loops)
-#define SESE_LOOP_NEST(S) (S->loop_nest)
+  /* Copied basic blocks indexed by the original bb.  */
+  bb_map_t *copied_bb_map;
+
+  /* A vector of phi nodes to be updated when all arguments are available.  The
+     pair contains first the old_phi and second the new_phi.  */
+  vec<phi_rename> incomplete_phis;
+
+  /* The condition region generated for this sese.  */
+  ifsese if_region;
+
+} *sese_info_p;
 
 extern sese_info_p new_sese_info (edge, edge);
 extern void free_sese_info (sese_info_p);
@@ -80,13 +114,23 @@ extern edge copy_bb_and_scalar_dependences (basic_block, sese_info_p, edge,
 extern struct loop *outermost_loop_in_sese (sese_l &, basic_block);
 extern tree scalar_evolution_in_region (sese_l &, loop_p, tree);
 extern bool invariant_in_sese_p_rec (tree, sese_l &, bool *);
+extern bool bb_contains_loop_phi_nodes (basic_block);
+extern bool bb_contains_loop_close_phi_nodes (basic_block);
+extern std::pair<edge, edge> get_edges (basic_block bb);
+extern void copy_loop_phi_args (gphi *, init_back_edge_pair_t &,
+				gphi *, init_back_edge_pair_t &,
+				sese_info_p, bool);
+extern bool copy_loop_close_phi_args (basic_block, basic_block,
+				      sese_info_p, bool);
+extern bool copy_cond_phi_args (gphi *, gphi *, vec<tree>,
+				sese_info_p, bool);
 
 /* Check that SESE contains LOOP.  */
 
 static inline bool
 sese_contains_loop (sese_info_p sese, struct loop *loop)
 {
-  return bitmap_bit_p (SESE_LOOPS (sese), loop->num);
+  return bitmap_bit_p (sese->loops, loop->num);
 }
 
 /* The number of parameters in REGION. */
@@ -94,7 +138,7 @@ sese_contains_loop (sese_info_p sese, struct loop *loop)
 static inline unsigned
 sese_nb_params (sese_info_p region)
 {
-  return SESE_PARAMS (region).length ();
+  return region->params.length ();
 }
 
 /* Checks whether BB is contained in the region delimited by ENTRY and
@@ -239,6 +283,8 @@ recompute_all_dominators (void)
   calculate_dominance_info (CDI_POST_DOMINATORS);
 }
 
+typedef std::pair <gimple *, tree> scalar_use;
+
 typedef struct gimple_poly_bb
 {
   basic_block bb;
@@ -267,6 +313,8 @@ typedef struct gimple_poly_bb
   vec<gimple *> conditions;
   vec<gimple *> condition_cases;
   vec<data_reference_p> data_refs;
+  vec<scalar_use> read_scalar_refs;
+  vec<tree> write_scalar_refs;
 } *gimple_poly_bb_p;
 
 #define GBB_BB(GBB) (GBB)->bb