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

gcc/ChangeLog

 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.
+
+2017-10-13  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/82525
 	* graphite-isl-ast-to-gimple.c
 	(translate_isl_ast_to_gimple::widest_int_from_isl_expr_int): Split

gcc/cfgloop.c

@@ -1713,12 +1713,19 @@ loop_preheader_edge (const struct loop *loop)
   edge e;
   edge_iterator ei;
 
-  gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS));
+  gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS)
+	      && ! loops_state_satisfies_p (LOOPS_MAY_HAVE_MULTIPLE_LATCHES));
 
   FOR_EACH_EDGE (e, ei, loop->header->preds)
     if (e->src != loop->latch)
       break;
 
+  if (! e)
+    {
+      gcc_assert (! loop_outer (loop));
+      return single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun));
+    }
+
   return e;
 }
 

gcc/graphite-isl-ast-to-gimple.c

@@ -750,10 +750,8 @@ build_iv_mapping (vec<tree> iv_map, gimple_poly_bb_p gbb,
       if (codegen_error_p ())
 	t = integer_zero_node;
 
-      loop_p old_loop = gbb_loop_at_index (gbb, region, i - 2);
-      /* Record sth only for real loops.  */
-      if (loop_in_sese_p (old_loop, region))
-	iv_map[old_loop->num] = t;
+      loop_p old_loop = gbb_loop_at_index (gbb, region, i - 1);
+      iv_map[old_loop->num] = t;
     }
 }
 
@@ -1571,6 +1569,12 @@ graphite_regenerate_ast_isl (scop_p scop)
       update_ssa (TODO_update_ssa);
       checking_verify_ssa (true, true);
       rewrite_into_loop_closed_ssa (NULL, 0);
+      /* We analyzed evolutions of all SCOPs during SCOP detection
+         which cached evolutions.  Now we've introduced PHIs for
+	 liveouts which causes those cached solutions to be invalid
+	 for code-generation purposes given we'd insert references
+	 to SSA names not dominating their new use.  */
+      scev_reset ();
     }
 
   if (t.codegen_error_p ())

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))

gcc/graphite-sese-to-poly.c

@@ -86,7 +86,7 @@ extract_affine_chrec (scop_p s, tree e, __isl_take isl_space *space)
   isl_pw_aff *lhs = extract_affine (s, CHREC_LEFT (e), isl_space_copy (space));
   isl_pw_aff *rhs = extract_affine (s, CHREC_RIGHT (e), isl_space_copy (space));
   isl_local_space *ls = isl_local_space_from_space (space);
-  unsigned pos = sese_loop_depth (s->scop_info->region, get_chrec_loop (e));
+  unsigned pos = sese_loop_depth (s->scop_info->region, get_chrec_loop (e)) - 1;
   isl_aff *loop = isl_aff_set_coefficient_si
     (isl_aff_zero_on_domain (ls), isl_dim_in, pos, 1);
   isl_pw_aff *l = isl_pw_aff_from_aff (loop);
@@ -763,10 +763,10 @@ add_loop_constraints (scop_p scop, __isl_take isl_set *domain, loop_p loop,
     return domain;
   const sese_l &region = scop->scop_info->region;
   if (!loop_in_sese_p (loop, region))
-    ;
-  else
-    /* Recursion all the way up to the context loop.  */
-    domain = add_loop_constraints (scop, domain, loop_outer (loop), context);
+    return domain;
+
+  /* Recursion all the way up to the context loop.  */
+  domain = add_loop_constraints (scop, domain, loop_outer (loop), context);
 
   /* Then, build constraints over the loop in post-order: outer to inner.  */
 
@@ -777,21 +777,6 @@ add_loop_constraints (scop_p scop, __isl_take isl_set *domain, loop_p loop,
   domain = add_iter_domain_dimension (domain, loop, scop);
   isl_space *space = isl_set_get_space (domain);
 
-  if (!loop_in_sese_p (loop, region))
-    {
-      /* 0 == loop_i */
-      isl_local_space *ls = isl_local_space_from_space (space);
-      isl_constraint *c = isl_equality_alloc (ls);
-      c = isl_constraint_set_coefficient_si (c, isl_dim_set, loop_index, 1);
-      if (dump_file)
-	{
-	  fprintf (dump_file, "[sese-to-poly] adding constraint to the domain: ");
-	  print_isl_constraint (dump_file, c);
-	}
-      domain = isl_set_add_constraint (domain, c);
-      return domain;
-    }
-
   /* 0 <= loop_i */
   isl_local_space *ls = isl_local_space_from_space (isl_space_copy (space));
   isl_constraint *c = isl_inequality_alloc (ls);

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.  */

gcc/sese.h

@@ -334,6 +334,8 @@ gbb_loop_at_index (gimple_poly_bb_p gbb, sese_l &region, int index)
   while (--depth > index)
     loop = loop_outer (loop);
 
+  gcc_assert (loop_in_sese_p (loop, region));
+
   return loop;
 }
 

gcc/testsuite/ChangeLog

 2017-10-13  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/82451
+	* gcc.dg/graphite/pr82451.c: New testcase.
+	* gfortran.dg/graphite/id-27.f90: Likewise.
+	* gfortran.dg/graphite/pr82451.f: Likewise.
+
+2017-10-13  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/82525
 	* gcc.dg/graphite/id-30.c: New testcase.
 	* gfortran.dg/graphite/id-28.f90: Likewise.

gcc/testsuite/gcc.dg/graphite/fuse-1.c

 /* Check that the two loops are fused and that we manage to fold the two xor
    operations.  */
-/* { dg-options "-O2 -floop-nest-optimize -fdump-tree-forwprop4-all -fdump-tree-graphite-all" } */
+/* { dg-options "-O2 -floop-nest-optimize -fdump-tree-forwprop-all -fdump-tree-graphite-all" } */
 
 /* Make sure we fuse the loops like this:
 AST generated by isl:
 for (int c0 = 0; c0 <= 99; c0 += 1) {
-  S_3(0, c0);
-  S_6(0, c0);
-  S_9(0, c0);
+  S_3(c0);
+  S_6(c0);
+  S_9(c0);
 } */
-/* { dg-final { scan-tree-dump-times "AST generated by isl:.*for \\(int c0 = 0; c0 <= 99; c0 \\+= 1\\) \\{.*S_.*\\(0, c0\\);.*S_.*\\(0, c0\\);.*S_.*\\(0, c0\\);.*\\}" 1 "graphite" } } */
+/* { dg-final { scan-tree-dump-times "AST generated by isl:.*for \\(int c0 = 0; c0 <= 99; c0 \\+= 1\\) \\{.*S_.*\\(c0\\);.*S_.*\\(c0\\);.*S_.*\\(c0\\);.*\\}" 1 "graphite" } } */
 
 /* Check that after fusing the loops, the scalar computation is also fused.  */
 /* { dg-final { scan-tree-dump-times "gimple_simplified to\[^\\n\]*\\^ 12" 1 "forwprop4" } } */

gcc/testsuite/gcc.dg/graphite/fuse-2.c

@@ -3,13 +3,13 @@
 /* Make sure we fuse the loops like this:
 AST generated by isl:
 for (int c0 = 0; c0 <= 99; c0 += 1) {
-  S_3(0, c0);
-  S_6(0, c0);
-  S_9(0, c0);
+  S_3(c0);
+  S_6(c0);
+  S_9(c0);
 }
 */
 
-/* { dg-final { scan-tree-dump-times "AST generated by isl:.*for \\(int c0 = 0; c0 <= 99; c0 \\+= 1\\) \\{.*S_.*\\(0, c0\\);.*S_.*\\(0, c0\\);.*S_.*\\(0, c0\\);.*\\}" 1 "graphite" } } */
+/* { dg-final { scan-tree-dump-times "AST generated by isl:.*for \\(int c0 = 0; c0 <= 99; c0 \\+= 1\\) \\{.*S_.*\\(c0\\);.*S_.*\\(c0\\);.*S_.*\\(c0\\);.*\\}" 1 "graphite" } } */
 
 #define MAX 100
 int A[MAX], B[MAX], C[MAX];

gcc/testsuite/gcc.dg/graphite/pr82451.c

+/* { dg-do compile } */
+/* { dg-options "-O -floop-parallelize-all" } */
+
+static int a[];
+int b[1];
+int c;
+static void
+d (int *f, int *g)
+{
+  int e;
+  for (e = 0; e < 2; e++)
+    g[e] = 1;
+  for (e = 0; e < 2; e++)
+    g[e] = f[e] + f[e + 1];
+}
+void
+h ()
+{
+  for (;; c += 8)
+    d (&a[c], b);
+}

gcc/testsuite/gfortran.dg/graphite/id-27.f90

+! { dg-additional-options "-Ofast" }
+MODULE module_ra_gfdleta
+      INTEGER, PARAMETER              :: NBLY=15
+      REAL   , SAVE :: EM1(28,180),EM1WDE(28,180),TABLE1(28,180),     &
+                           TABLE2(28,180),TABLE3(28,180),EM3(28,180), &
+                           SOURCE(28,NBLY), DSRCE(28,NBLY)
+CONTAINS
+      SUBROUTINE TABLE 
+ INTEGER, PARAMETER :: NBLX=47
+ INTEGER , PARAMETER:: NBLW = 163
+      REAL ::  &
+               SUM(28,180),PERTSM(28,180),SUM3(28,180),       &
+               SUMWDE(28,180),SRCWD(28,NBLX),SRC1NB(28,NBLW), &
+               DBDTNB(28,NBLW)
+      REAL ::  &
+               ZMASS(181),ZROOT(181),SC(28),DSC(28),XTEMV(28), &
+               TFOUR(28),FORTCU(28),X(28),X1(28),X2(180),SRCS(28), &
+               R1T(28),R2(28),S2(28),T3(28),R1WD(28)
+      REAL ::  EXPO(180),FAC(180)
+      I = 0
+      DO 417 J=121,180
+      FAC(J)=ZMASS(J)*(ONE-(ONE+X2(J))*EXPO(J))/(X2(J)*X2(J))
+417   CONTINUE
+      DO 421 J=121,180
+      SUM3(I,J)=SUM3(I,J)+DBDTNB(I,N)*FAC(J)
+421   CONTINUE
+      IF (CENT.GT.160. .AND. CENT.LT.560.) THEN
+         DO 420 J=1,180
+         DO 420 I=1,28
+         SUMWDE(I,J)=SUMWDE(I,J)+SRC1NB(I,N)*EXPO(J)
+420      CONTINUE
+      ENDIF
+      DO 433 J=121,180
+      EM3(I,J)=SUM3(I,J)/FORTCU(I)
+433   CONTINUE
+      DO 501 I=1,28
+      EM1WDE(I,J)=SUMWDE(I,J)/TFOUR(I)
+501   CONTINUE
+      END SUBROUTINE TABLE
+      END MODULE module_RA_GFDLETA

gcc/testsuite/gfortran.dg/graphite/pr82451.f

+! { dg-do compile }
+! { dg-options "-O2 -floop-nest-optimize" }
+      MODULE LES3D_DATA
+      PARAMETER ( NSCHEME = 4, ICHEM = 0, ISGSK = 0, IVISC = 1 )
+      DOUBLE PRECISION DT, TIME, STATTIME, CFL, RELNO, TSTND, ALREF
+      INTEGER IDYN, IMAX, JMAX, KMAX
+      PARAMETER( RUNIV =  8.3145D3,
+     >        TPRANDLT =    0.91D0)
+      DOUBLE PRECISION,ALLOCATABLE,DIMENSION(:,:,:) ::
+     >             U, V, W, P, T, H, EK,
+     >         UAV, VAV, WAV, PAV, TAV, HAV, EKAV
+      DOUBLE PRECISION,ALLOCATABLE,DIMENSION(:,:,:,:) ::
+     >             CONC, HF, QAV, COAV, HFAV, DU
+      DOUBLE PRECISION,ALLOCATABLE,DIMENSION(:,:,:,:,:) ::
+     >             Q
+      END MODULE LES3D_DATA
+      SUBROUTINE FLUXJ()
+      USE LES3D_DATA
+      ALLOCATABLE QS(:), FSJ(:,:,:)
+      ALLOCATABLE DWDX(:),DWDY(:),DWDZ(:)
+      ALLOCATABLE DHDY(:), DKDY(:)
+      PARAMETER (  R12I = 1.0D0 / 12.0D0,
+     >             TWO3 = 2.0D0 / 3.0D0 )
+      ALLOCATE( QS(IMAX-1), FSJ(IMAX-1,0:JMAX-1,ND))
+      ALLOCATE( DWDX(IMAX-1),DWDY(IMAX-1),DWDZ(IMAX-1))
+      I1 = 1
+      DO K = K1,K2
+         DO J = J1,J2
+            DO I = I1, I2
+               FSJ(I,J,5) = FSJ(I,J,5) + PAV(I,J,K) * QS(I)
+            END DO
+            DO I = I1, I2
+               DWDX(I) = DXI * R12I * (WAV(I-2,J,K) - WAV(I+2,J,K) +
+     >                        8.0D0 * (WAV(I+1,J,K) - WAV(I-1,J,K)))
+            END DO
+         END DO
+      END DO
+      DEALLOCATE( QS, FSJ, DHDY, DKDY)
+      END

gcc/tree-data-ref.c

@@ -957,15 +957,14 @@ access_fn_component_p (tree op)
 }
 
 /* Determines the base object and the list of indices of memory reference
-   DR, analyzed in LOOP and instantiated in loop nest NEST.  */
+   DR, analyzed in LOOP and instantiated before NEST.  */
 
 static void
-dr_analyze_indices (struct data_reference *dr, loop_p nest, loop_p loop)
+dr_analyze_indices (struct data_reference *dr, edge nest, loop_p loop)
 {
   vec<tree> access_fns = vNULL;
   tree ref, op;
   tree base, off, access_fn;
-  basic_block before_loop;
 
   /* If analyzing a basic-block there are no indices to analyze
      and thus no access functions.  */
@@ -977,7 +976,6 @@ dr_analyze_indices (struct data_reference *dr, loop_p nest, loop_p loop)
     }
 
   ref = DR_REF (dr);
-  before_loop = block_before_loop (nest);
 
   /* REALPART_EXPR and IMAGPART_EXPR can be handled like accesses
      into a two element array with a constant index.  The base is
@@ -1002,7 +1000,7 @@ dr_analyze_indices (struct data_reference *dr, loop_p nest, loop_p loop)
 	{
 	  op = TREE_OPERAND (ref, 1);
 	  access_fn = analyze_scalar_evolution (loop, op);
-	  access_fn = instantiate_scev (before_loop, loop, access_fn);
+	  access_fn = instantiate_scev (nest, loop, access_fn);
 	  access_fns.safe_push (access_fn);
 	}
       else if (TREE_CODE (ref) == COMPONENT_REF
@@ -1034,7 +1032,7 @@ dr_analyze_indices (struct data_reference *dr, loop_p nest, loop_p loop)
     {
       op = TREE_OPERAND (ref, 0);
       access_fn = analyze_scalar_evolution (loop, op);
-      access_fn = instantiate_scev (before_loop, loop, access_fn);
+      access_fn = instantiate_scev (nest, loop, access_fn);
       if (TREE_CODE (access_fn) == POLYNOMIAL_CHREC)
 	{
 	  tree orig_type;
@@ -1139,7 +1137,7 @@ free_data_ref (data_reference_p dr)
    in which the data reference should be analyzed.  */
 
 struct data_reference *
-create_data_ref (loop_p nest, loop_p loop, tree memref, gimple *stmt,
+create_data_ref (edge nest, loop_p loop, tree memref, gimple *stmt,
 		 bool is_read, bool is_conditional_in_stmt)
 {
   struct data_reference *dr;
@@ -4970,7 +4968,8 @@ find_data_references_in_stmt (struct loop *nest, gimple *stmt,
 
   FOR_EACH_VEC_ELT (references, i, ref)
     {
-      dr = create_data_ref (nest, loop_containing_stmt (stmt), ref->ref,
+      dr = create_data_ref (nest ? loop_preheader_edge (nest) : NULL,
+			    loop_containing_stmt (stmt), ref->ref,
 			    stmt, ref->is_read, ref->is_conditional_in_stmt);
       gcc_assert (dr != NULL);
       datarefs->safe_push (dr);
@@ -4986,7 +4985,7 @@ find_data_references_in_stmt (struct loop *nest, gimple *stmt,
    should be analyzed.  */
 
 bool
-graphite_find_data_references_in_stmt (loop_p nest, loop_p loop, gimple *stmt,
+graphite_find_data_references_in_stmt (edge nest, loop_p loop, gimple *stmt,
 				       vec<data_reference_p> *datarefs)
 {
   unsigned i;

gcc/tree-data-ref.h

@@ -436,11 +436,11 @@ extern void free_data_ref (data_reference_p);
 extern void free_data_refs (vec<data_reference_p> );
 extern bool find_data_references_in_stmt (struct loop *, gimple *,
 					  vec<data_reference_p> *);
-extern bool graphite_find_data_references_in_stmt (loop_p, loop_p, gimple *,
+extern bool graphite_find_data_references_in_stmt (edge, loop_p, gimple *,
 						   vec<data_reference_p> *);
 tree find_data_references_in_loop (struct loop *, vec<data_reference_p> *);
 bool loop_nest_has_data_refs (loop_p loop);
-struct data_reference *create_data_ref (loop_p, loop_p, tree, gimple *, bool,
+struct data_reference *create_data_ref (edge, loop_p, tree, gimple *, bool,
 					bool);
 extern bool find_loop_nest (struct loop *, vec<loop_p> *);
 extern struct data_dependence_relation *initialize_data_dependence_relation

gcc/tree-scalar-evolution.h

@@ -30,7 +30,7 @@ extern void scev_reset (void);
 extern void scev_reset_htab (void);
 extern void scev_finalize (void);
 extern tree analyze_scalar_evolution (struct loop *, tree);
-extern tree instantiate_scev (basic_block, struct loop *, tree);
+extern tree instantiate_scev (edge, struct loop *, tree);
 extern tree resolve_mixers (struct loop *, tree, bool *);
 extern void gather_stats_on_scev_database (void);
 extern void final_value_replacement_loop (struct loop *);
@@ -60,7 +60,7 @@ block_before_loop (loop_p loop)
 static inline tree
 instantiate_parameters (struct loop *loop, tree chrec)
 {
-  return instantiate_scev (block_before_loop (loop), loop, chrec);
+  return instantiate_scev (loop_preheader_edge (loop), loop, chrec);
 }
 
 /* Returns the loop of the polynomial chrec CHREC.  */

gcc/tree-ssa-loop-prefetch.c

@@ -1632,7 +1632,8 @@ determine_loop_nest_reuse (struct loop *loop, struct mem_ref_group *refs,
   for (gr = refs; gr; gr = gr->next)
     for (ref = gr->refs; ref; ref = ref->next)
       {
-	dr = create_data_ref (nest, loop_containing_stmt (ref->stmt),
+	dr = create_data_ref (loop_preheader_edge (nest),
+			      loop_containing_stmt (ref->stmt),
 			      ref->mem, ref->stmt, !ref->write_p, false);
 
 	if (dr)