re PR tree-optimization/82451 ([GRAPHITE] codegen error in get_rename_from_scev)

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.

From-SVN: r253707

1 files changed, 2 insertions, 3 deletions

diff --git a/gcc/sese.c b/gcc/sese.c
index d6702ad..8aa8015 100644
--- a/gcc/sese.c
+++ b/gcc/sese.c
@@ -461,7 +461,6 @@ scalar_evolution_in_region (const sese_l &region, loop_p loop, tree t)
 {
   gimple *def;
   struct loop *def_loop;
-  basic_block before = region.entry->src;
 
   /* SCOP parameters.  */
   if (TREE_CODE (t) == SSA_NAME
@@ -472,7 +471,7 @@ scalar_evolution_in_region (const sese_l &region, loop_p loop, tree t)
       || loop_in_sese_p (loop, region))
     /* FIXME: we would need instantiate SCEV to work on a region, and be more
        flexible wrt. memory loads that may be invariant in the region.  */
-    return instantiate_scev (before, loop,
+    return instantiate_scev (region.entry, loop,
 			     analyze_scalar_evolution (loop, t));
 
   def = SSA_NAME_DEF_STMT (t);
@@ -494,7 +493,7 @@ scalar_evolution_in_region (const sese_l &region, loop_p loop, tree t)
   if (has_vdefs)
     return chrec_dont_know;
 
-  return instantiate_scev (before, loop, t);
+  return instantiate_scev (region.entry, loop, t);
 }
 
 /* Return true if BB is empty, contains only DEBUG_INSNs.  */