2017-10-13 Richard Biener <rguenther@suse.de>

	PR tree-optimization/82451
	Revert
	2017-10-02  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/82355
	* graphite-isl-ast-to-gimple.c (build_iv_mapping): Also build
	a mapping for the enclosing loop but avoid generating one for
	the loop tree root.
	(copy_bb_and_scalar_dependences): Remove premature codegen
	error on PHIs in blocks duplicated into multiple places.
	* graphite-scop-detection.c
	(scop_detection::stmt_has_simple_data_refs_p): For a loop not
	in the region use it as loop and nest to analyze the DR in.
	(try_generate_gimple_bb): Likewise.
	* graphite-sese-to-poly.c (extract_affine_chrec): Adjust.
	(add_loop_constraints): For blocks in a loop not in the region
	create a dimension with a single iteration.
	* sese.h (gbb_loop_at_index): Remove assert.

	* cfgloop.c (loop_preheader_edge): For the loop tree root
	return the single successor of the entry block.
	* graphite-isl-ast-to-gimple.c (graphite_regenerate_ast_isl):
	Reset the SCEV hashtable and niters.
	* graphite-scop-detection.c
	(scop_detection::graphite_can_represent_scev): Add SCOP parameter,
	assert that we only have POLYNOMIAL_CHREC that vary in loops
	contained in the region.
	(scop_detection::graphite_can_represent_expr): Adjust.
	(scop_detection::stmt_has_simple_data_refs_p): For loops
	not in the region set loop to NULL.  The nest is now the
	entry edge to the region.
	(try_generate_gimple_bb): Likewise.
	* sese.c (scalar_evolution_in_region): Adjust for
	instantiate_scev change.
	* tree-data-ref.h (graphite_find_data_references_in_stmt):
	Make nest parameter the edge into the region.
	(create_data_ref): Likewise.
	* tree-data-ref.c (dr_analyze_indices): Make nest parameter an
	entry edge into a region and adjust instantiate_scev calls.
	(create_data_ref): Likewise.
	(graphite_find_data_references_in_stmt): Likewise.
	(find_data_references_in_stmt): Pass the loop preheader edge
	from the nest argument.
	* tree-scalar-evolution.h (instantiate_scev): Make instantiate_below
	parameter the edge into the region.
	(instantiate_parameters): Use the loop preheader edge as entry.
	* tree-scalar-evolution.c (analyze_scalar_evolution): Handle
	NULL loop.
	(get_instantiated_value_entry): Make instantiate_below parameter
	the edge into the region.
	(instantiate_scev_name): Likewise.  Adjust dominance checks,
	when we cannot use loop-based instantiation instantiate by
	walking use-def chains.
	(instantiate_scev_poly): Adjust.
	(instantiate_scev_binary): Likewise.
	(instantiate_scev_convert): Likewise.
	(instantiate_scev_not): Likewise.
	(instantiate_array_ref): Remove.
	(instantiate_scev_3): Likewise.
	(instantiate_scev_2): Likewise.
	(instantiate_scev_1): Likewise.
	(instantiate_scev_r): Do not blindly handle N-operand trees.
	Do not instantiate array-refs.  Handle all constants and invariants.
	(instantiate_scev): Make instantiate_below parameter
	the edge into the region.
	(resolve_mixers): Use the loop preheader edge for the region
	parameter to instantiate_scev_r.
	* tree-ssa-loop-prefetch.c (determine_loop_nest_reuse): Adjust.

	* gcc.dg/graphite/pr82451.c: New testcase.
	* gfortran.dg/graphite/id-27.f90: Likewise.
	* gfortran.dg/graphite/pr82451.f: Likewise.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@253707 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 24 insertions, 16 deletions

diff --git a/gcc/graphite-scop-detection.c b/gcc/graphite-scop-detection.c
index 3cd99322b77..c7e1dba9423 100644
--- a/gcc/graphite-scop-detection.c
+++ b/gcc/graphite-scop-detection.c
@@ -381,7 +381,7 @@ public:
 
      Something like "i * n" or "n * m" is not allowed.  */
 
-  static bool graphite_can_represent_scev (tree scev);
+  static bool graphite_can_represent_scev (sese_l scop, tree scev);
 
   /* Return true when EXPR can be represented in the polyhedral model.
 
@@ -934,7 +934,7 @@ scop_detection::graphite_can_represent_init (tree e)
    Something like "i * n" or "n * m" is not allowed.  */
 
 bool
-scop_detection::graphite_can_represent_scev (tree scev)
+scop_detection::graphite_can_represent_scev (sese_l scop, tree scev)
 {
   if (chrec_contains_undetermined (scev))
     return false;
@@ -945,13 +945,13 @@ scop_detection::graphite_can_represent_scev (tree scev)
     case BIT_NOT_EXPR:
     CASE_CONVERT:
     case NON_LVALUE_EXPR:
-      return graphite_can_represent_scev (TREE_OPERAND (scev, 0));
+      return graphite_can_represent_scev (scop, TREE_OPERAND (scev, 0));
 
     case PLUS_EXPR:
     case POINTER_PLUS_EXPR:
     case MINUS_EXPR:
-      return graphite_can_represent_scev (TREE_OPERAND (scev, 0))
-	&& graphite_can_represent_scev (TREE_OPERAND (scev, 1));
+      return graphite_can_represent_scev (scop, TREE_OPERAND (scev, 0))
+	&& graphite_can_represent_scev (scop, TREE_OPERAND (scev, 1));
 
     case MULT_EXPR:
       return !CONVERT_EXPR_CODE_P (TREE_CODE (TREE_OPERAND (scev, 0)))
@@ -959,18 +959,20 @@ scop_detection::graphite_can_represent_scev (tree scev)
 	&& !(chrec_contains_symbols (TREE_OPERAND (scev, 0))
 	     && chrec_contains_symbols (TREE_OPERAND (scev, 1)))
 	&& graphite_can_represent_init (scev)
-	&& graphite_can_represent_scev (TREE_OPERAND (scev, 0))
-	&& graphite_can_represent_scev (TREE_OPERAND (scev, 1));
+	&& graphite_can_represent_scev (scop, TREE_OPERAND (scev, 0))
+	&& graphite_can_represent_scev (scop, TREE_OPERAND (scev, 1));
 
     case POLYNOMIAL_CHREC:
       /* Check for constant strides.  With a non constant stride of
 	 'n' we would have a value of 'iv * n'.  Also check that the
 	 initial value can represented: for example 'n * m' cannot be
 	 represented.  */
+      gcc_assert (loop_in_sese_p (get_loop (cfun,
+					    CHREC_VARIABLE (scev)), scop));
       if (!evolution_function_right_is_integer_cst (scev)
 	  || !graphite_can_represent_init (scev))
 	return false;
-      return graphite_can_represent_scev (CHREC_LEFT (scev));
+      return graphite_can_represent_scev (scop, CHREC_LEFT (scev));
 
     default:
       break;
@@ -994,7 +996,7 @@ scop_detection::graphite_can_represent_expr (sese_l scop, loop_p loop,
 					     tree expr)
 {
   tree scev = scalar_evolution_in_region (scop, loop, expr);
-  return graphite_can_represent_scev (scev);
+  return graphite_can_represent_scev (scop, scev);
 }
 
 /* Return true if the data references of STMT can be represented by Graphite.
@@ -1003,12 +1005,15 @@ scop_detection::graphite_can_represent_expr (sese_l scop, loop_p loop,
 bool
 scop_detection::stmt_has_simple_data_refs_p (sese_l scop, gimple *stmt)
 {
-  loop_p nest;
+  edge nest;
   loop_p loop = loop_containing_stmt (stmt);
   if (!loop_in_sese_p (loop, scop))
-    nest = loop;
+    {
+      nest = scop.entry;
+      loop = NULL;
+    }
   else
-    nest = outermost_loop_in_sese (scop, gimple_bb (stmt));
+    nest = loop_preheader_edge (outermost_loop_in_sese (scop, gimple_bb (stmt)));
 
   auto_vec<data_reference_p> drs;
   if (! graphite_find_data_references_in_stmt (nest, loop, stmt, &drs))
@@ -1019,7 +1024,7 @@ scop_detection::stmt_has_simple_data_refs_p (sese_l scop, gimple *stmt)
   FOR_EACH_VEC_ELT (drs, j, dr)
     {
       for (unsigned i = 0; i < DR_NUM_DIMENSIONS (dr); ++i)
-	if (! graphite_can_represent_scev (DR_ACCESS_FN (dr, i)))
+	if (! graphite_can_represent_scev (scop, DR_ACCESS_FN (dr, i)))
 	  return false;
     }
 
@@ -1376,12 +1381,15 @@ try_generate_gimple_bb (scop_p scop, basic_block bb)
   vec<scalar_use> reads = vNULL;
 
   sese_l region = scop->scop_info->region;
-  loop_p nest;
+  edge nest;
   loop_p loop = bb->loop_father;
   if (!loop_in_sese_p (loop, region))
-    nest = loop;
+    {
+      nest = region.entry;
+      loop = NULL;
+    }
   else
-    nest = outermost_loop_in_sese (region, bb);
+    nest = loop_preheader_edge (outermost_loop_in_sese (region, bb));
 
   for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi);
        gsi_next (&gsi))