[gcc/devel/omp/gcc-11] Remove duplicate SESE code in NVPTX backend

[gcc/devel/omp/gcc-11] Remove duplicate SESE code in NVPTX backend

[Kwok Yeung]

https://gcc.gnu.org/g:f963d6c79b1d52ce565c772166c3c3e1b1d0aa78

commit f963d6c79b1d52ce565c772166c3c3e1b1d0aa78
Author: Julian Brown <julian@codesourcery.com>
Date:   Fri Sep 6 04:53:17 2019 -0700

    Remove duplicate SESE code in NVPTX backend
    
            gcc/
            * config/nvptx/nvptx.c (omp-sese.h): Include.
            (bb_pair_t, bb_pair_vec_t, pseudo_node_t, bracket, bracket_vec_t,
            bb_sese, bb_sese::~bb_sese, bb_sese::append, bb_sese::remove,
            BB_SET_SESE, BB_GET_SESE, nvptx_sese_number, nvptx_sese_pseudo,
            nvptx_sese_color, nvptx_find_sese): Remove.
            (nvptx_neuter_pars): Call omp_find_sese instead of nvptx_find_sese.
            * omp-sese.c (omp-sese.h): Include.
            (struct parallel): Rename to...
            (struct parallel_g): This.
            (parallel::parallel, parallel::~parallel): Rename to...
            (parallel_g::parallel_g, parallel_g::~parallel_g): These.
            (omp_sese_dump_pars, omp_sese_find_par, omp_sese_discover_pars,
            populate_single_mode_bitmaps, find_ssa_names_to_propagate,
            find_partitioned_var_uses, find_local_vars_to_propagate,
            neuter_worker_single): Update for parallel_g name change.
            (bb_pair_t, bb_pair_vec_t): Remove.
            (omp_find_sese): Make global.
            * omp-sese.h (bb_pair_t, bb_pair_vec_t): New.
            (omp_find_sese): Add prototype.

Diff:
---
 gcc/ChangeLog.omp        |  22 ++
 gcc/config/nvptx/nvptx.c | 622 +----------------------------------------------
 gcc/omp-sese.c           |  61 +++--
 gcc/omp-sese.h           |   6 +
 4 files changed, 59 insertions(+), 652 deletions(-)

diff --git a/gcc/ChangeLog.omp b/gcc/ChangeLog.omp
index 0332bca6b67..b0ad743f5f7 100644
--- a/gcc/ChangeLog.omp
+++ b/gcc/ChangeLog.omp
@@ -1,3 +1,25 @@
+2019-09-06  Julian Brown  <julian@codesourcery.com>
+
+	* config/nvptx/nvptx.c (omp-sese.h): Include.
+	(bb_pair_t, bb_pair_vec_t, pseudo_node_t, bracket, bracket_vec_t,
+	bb_sese, bb_sese::~bb_sese, bb_sese::append, bb_sese::remove,
+	BB_SET_SESE, BB_GET_SESE, nvptx_sese_number, nvptx_sese_pseudo,
+	nvptx_sese_color, nvptx_find_sese): Remove.
+	(nvptx_neuter_pars): Call omp_find_sese instead of nvptx_find_sese.
+	* omp-sese.c (omp-sese.h): Include.
+	(struct parallel): Rename to...
+	(struct parallel_g): This.
+	(parallel::parallel, parallel::~parallel): Rename to...
+	(parallel_g::parallel_g, parallel_g::~parallel_g): These.
+	(omp_sese_dump_pars, omp_sese_find_par, omp_sese_discover_pars,
+	populate_single_mode_bitmaps, find_ssa_names_to_propagate,
+	find_partitioned_var_uses, find_local_vars_to_propagate,
+	neuter_worker_single): Update for parallel_g name change.
+	(bb_pair_t, bb_pair_vec_t): Remove.
+	(omp_find_sese): Make global.
+	* omp-sese.h (bb_pair_t, bb_pair_vec_t): New.
+	(omp_find_sese): Add prototype.
+
 2019-09-06  Julian Brown  <julian@codesourcery.com>
 
 	* gimplify.c (gimplify_omp_workshare): Use OMP_CLAUSES, OMP_BODY
diff --git a/gcc/config/nvptx/nvptx.c b/gcc/config/nvptx/nvptx.c
index eb24628eb05..347ca534c87 100644
--- a/gcc/config/nvptx/nvptx.c
+++ b/gcc/config/nvptx/nvptx.c
@@ -80,6 +80,7 @@
 #include "intl.h"
 #include "opts.h"
 #include "tree-hash-traits.h"
+#include "omp-sese.h"
 
 /* This file should be included last.  */
 #include "target-def.h"
@@ -3490,625 +3491,6 @@ nvptx_discover_pars (bb_insn_map_t *map)
   return par;
 }
 
-/* Analyse a group of BBs within a partitioned region and create N
-   Single-Entry-Single-Exit regions.  Some of those regions will be
-   trivial ones consisting of a single BB.  The blocks of a
-   partitioned region might form a set of disjoint graphs -- because
-   the region encloses a differently partitoned sub region.
-
-   We use the linear time algorithm described in 'Finding Regions Fast:
-   Single Entry Single Exit and control Regions in Linear Time'
-   Johnson, Pearson & Pingali.  That algorithm deals with complete
-   CFGs, where a back edge is inserted from END to START, and thus the
-   problem becomes one of finding equivalent loops.
-
-   In this case we have a partial CFG.  We complete it by redirecting
-   any incoming edge to the graph to be from an arbitrary external BB,
-   and similarly redirecting any outgoing edge to be to  that BB.
-   Thus we end up with a closed graph.
-
-   The algorithm works by building a spanning tree of an undirected
-   graph and keeping track of back edges from nodes further from the
-   root in the tree to nodes nearer to the root in the tree.  In the
-   description below, the root is up and the tree grows downwards.
-
-   We avoid having to deal with degenerate back-edges to the same
-   block, by splitting each BB into 3 -- one for input edges, one for
-   the node itself and one for the output edges.  Such back edges are
-   referred to as 'Brackets'.  Cycle equivalent nodes will have the
-   same set of brackets.
-   
-   Determining bracket equivalency is done by maintaining a list of
-   brackets in such a manner that the list length and final bracket
-   uniquely identify the set.
-
-   We use coloring to mark all BBs with cycle equivalency with the
-   same color.  This is the output of the 'Finding Regions Fast'
-   algorithm.  Notice it doesn't actually find the set of nodes within
-   a particular region, just unorderd sets of nodes that are the
-   entries and exits of SESE regions.
-   
-   After determining cycle equivalency, we need to find the minimal
-   set of SESE regions.  Do this with a DFS coloring walk of the
-   complete graph.  We're either 'looking' or 'coloring'.  When
-   looking, and we're in the subgraph, we start coloring the color of
-   the current node, and remember that node as the start of the
-   current color's SESE region.  Every time we go to a new node, we
-   decrement the count of nodes with thet color.  If it reaches zero,
-   we remember that node as the end of the current color's SESE region
-   and return to 'looking'.  Otherwise we color the node the current
-   color.
-
-   This way we end up with coloring the inside of non-trivial SESE
-   regions with the color of that region.  */
-
-/* A pair of BBs.  We use this to represent SESE regions.  */
-typedef std::pair<basic_block, basic_block> bb_pair_t;
-typedef auto_vec<bb_pair_t> bb_pair_vec_t;
-
-/* A node in the undirected CFG.  The discriminator SECOND indicates just
-   above or just below the BB idicated by FIRST.  */
-typedef std::pair<basic_block, int> pseudo_node_t;
-
-/* A bracket indicates an edge towards the root of the spanning tree of the
-   undirected graph.  Each bracket has a color, determined
-   from the currrent set of brackets.  */
-struct bracket
-{
-  pseudo_node_t back; /* Back target */
-
-  /* Current color and size of set.  */
-  unsigned color;
-  unsigned size;
-
-  bracket (pseudo_node_t back_)
-  : back (back_), color (~0u), size (~0u)
-  {
-  }
-
-  unsigned get_color (auto_vec<unsigned> &color_counts, unsigned length)
-  {
-    if (length != size)
-      {
-	size = length;
-	color = color_counts.length ();
-	color_counts.quick_push (0);
-      }
-    color_counts[color]++;
-    return color;
-  }
-};
-
-typedef auto_vec<bracket> bracket_vec_t;
-
-/* Basic block info for finding SESE regions.    */
-
-struct bb_sese
-{
-  int node;  /* Node number in spanning tree.  */
-  int parent; /* Parent node number.  */
-
-  /* The algorithm splits each node A into Ai, A', Ao. The incoming
-     edges arrive at pseudo-node Ai and the outgoing edges leave at
-     pseudo-node Ao.  We have to remember which way we arrived at a
-     particular node when generating the spanning tree.  dir > 0 means
-     we arrived at Ai, dir < 0 means we arrived at Ao.  */
-  int dir;
-
-  /* Lowest numbered pseudo-node reached via a backedge from thsis
-     node, or any descendant.  */
-  pseudo_node_t high;
-
-  int color;  /* Cycle-equivalence color  */
-
-  /* Stack of brackets for this node.  */
-  bracket_vec_t brackets;
-
-  bb_sese (unsigned node_, unsigned p, int dir_)
-  :node (node_), parent (p), dir (dir_)
-  {
-  }
-  ~bb_sese ();
-
-  /* Push a bracket ending at BACK.  */
-  void push (const pseudo_node_t &back)
-  {
-    if (dump_file)
-      fprintf (dump_file, "Pushing backedge %d:%+d\n",
-	       back.first ? back.first->index : 0, back.second);
-    brackets.safe_push (bracket (back));
-  }
-  
-  void append (bb_sese *child);
-  void remove (const pseudo_node_t &);
-
-  /* Set node's color.  */
-  void set_color (auto_vec<unsigned> &color_counts)
-  {
-    color = brackets.last ().get_color (color_counts, brackets.length ());
-  }
-};
-
-bb_sese::~bb_sese ()
-{
-}
-
-/* Destructively append CHILD's brackets.  */
-
-void
-bb_sese::append (bb_sese *child)
-{
-  if (int len = child->brackets.length ())
-    {
-      int ix;
-
-      if (dump_file)
-	{
-	  for (ix = 0; ix < len; ix++)
-	    {
-	      const pseudo_node_t &pseudo = child->brackets[ix].back;
-	      fprintf (dump_file, "Appending (%d)'s backedge %d:%+d\n",
-		       child->node, pseudo.first ? pseudo.first->index : 0,
-		       pseudo.second);
-	    }
-	}
-      if (!brackets.length ())
-	std::swap (brackets, child->brackets);
-      else
-	{
-	  brackets.reserve (len);
-	  for (ix = 0; ix < len; ix++)
-	    brackets.quick_push (child->brackets[ix]);
-	}
-    }
-}
-
-/* Remove brackets that terminate at PSEUDO.  */
-
-void
-bb_sese::remove (const pseudo_node_t &pseudo)
-{
-  unsigned removed = 0;
-  int len = brackets.length ();
-
-  for (int ix = 0; ix < len; ix++)
-    {
-      if (brackets[ix].back == pseudo)
-	{
-	  if (dump_file)
-	    fprintf (dump_file, "Removing backedge %d:%+d\n",
-		     pseudo.first ? pseudo.first->index : 0, pseudo.second);
-	  removed++;
-	}
-      else if (removed)
-	brackets[ix-removed] = brackets[ix];
-    }
-  while (removed--)
-    brackets.pop ();
-}
-
-/* Accessors for BB's aux pointer.  */
-#define BB_SET_SESE(B, S) ((B)->aux = (S))
-#define BB_GET_SESE(B) ((bb_sese *)(B)->aux)
-
-/* DFS walk creating SESE data structures.  Only cover nodes with
-   BB_VISITED set.  Append discovered blocks to LIST.  We number in
-   increments of 3 so that the above and below pseudo nodes can be
-   implicitly numbered too.  */
-
-static int
-nvptx_sese_number (int n, int p, int dir, basic_block b,
-		   auto_vec<basic_block> *list)
-{
-  if (BB_GET_SESE (b))
-    return n;
-
-  if (dump_file)
-    fprintf (dump_file, "Block %d(%d), parent (%d), orientation %+d\n",
-	     b->index, n, p, dir);
-  
-  BB_SET_SESE (b, new bb_sese (n, p, dir));
-  p = n;
-      
-  n += 3;
-  list->quick_push (b);
-
-  /* First walk the nodes on the 'other side' of this node, then walk
-     the nodes on the same side.  */
-  for (unsigned ix = 2; ix; ix--)
-    {
-      vec<edge, va_gc> *edges = dir > 0 ? b->succs : b->preds;
-      size_t offset = (dir > 0 ? offsetof (edge_def, dest)
-		       : offsetof (edge_def, src));
-      edge e;
-      edge_iterator ei;
-
-      FOR_EACH_EDGE (e, ei, edges)
-	{
-	  basic_block target = *(basic_block *)((char *)e + offset);
-	  
-	  if (target->flags & BB_VISITED)
-	    n = nvptx_sese_number (n, p, dir, target, list);
-	}
-      dir = -dir;
-    }
-  return n;
-}
-
-/* Process pseudo node above (DIR < 0) or below (DIR > 0) ME.
-   EDGES are the outgoing edges and OFFSET is the offset to the src
-   or dst block on the edges.   */
-
-static void
-nvptx_sese_pseudo (basic_block me, bb_sese *sese, int depth, int dir,
-		   vec<edge, va_gc> *edges, size_t offset)
-{
-  edge e;
-  edge_iterator ei;
-  int hi_back = depth;
-  pseudo_node_t node_back (0, depth);
-  int hi_child = depth;
-  pseudo_node_t node_child (0, depth);
-  basic_block child = NULL;
-  unsigned num_children = 0;
-  int usd = -dir * sese->dir;
-
-  if (dump_file)
-    fprintf (dump_file, "\nProcessing %d(%d) %+d\n",
-	     me->index, sese->node, dir);
-
-  if (dir < 0)
-    {
-      /* This is the above pseudo-child.  It has the BB itself as an
-	 additional child node.  */
-      node_child = sese->high;
-      hi_child = node_child.second;
-      if (node_child.first)
-	hi_child += BB_GET_SESE (node_child.first)->node;
-      num_children++;
-    }
-
-  /* Examine each edge.
-     - if it is a child (a) append its bracket list and (b) record
-          whether it is the child with the highest reaching bracket.
-     - if it is an edge to ancestor, record whether it's the highest
-          reaching backlink.  */
-  FOR_EACH_EDGE (e, ei, edges)
-    {
-      basic_block target = *(basic_block *)((char *)e + offset);
-
-      if (bb_sese *t_sese = BB_GET_SESE (target))
-	{
-	  if (t_sese->parent == sese->node && !(t_sese->dir + usd))
-	    {
-	      /* Child node.  Append its bracket list. */
-	      num_children++;
-	      sese->append (t_sese);
-
-	      /* Compare it's hi value.  */
-	      int t_hi = t_sese->high.second;
-
-	      if (basic_block child_hi_block = t_sese->high.first)
-		t_hi += BB_GET_SESE (child_hi_block)->node;
-
-	      if (hi_child > t_hi)
-		{
-		  hi_child = t_hi;
-		  node_child = t_sese->high;
-		  child = target;
-		}
-	    }
-	  else if (t_sese->node < sese->node + dir
-		   && !(dir < 0 && sese->parent == t_sese->node))
-	    {
-	      /* Non-parental ancestor node -- a backlink.  */
-	      int d = usd * t_sese->dir;
-	      int back = t_sese->node + d;
-	
-	      if (hi_back > back)
-		{
-		  hi_back = back;
-		  node_back = pseudo_node_t (target, d);
-		}
-	    }
-	}
-      else
-	{ /* Fallen off graph, backlink to entry node.  */
-	  hi_back = 0;
-	  node_back = pseudo_node_t (0, 0);
-	}
-    }
-
-  /* Remove any brackets that terminate at this pseudo node.  */
-  sese->remove (pseudo_node_t (me, dir));
-
-  /* Now push any backlinks from this pseudo node.  */
-  FOR_EACH_EDGE (e, ei, edges)
-    {
-      basic_block target = *(basic_block *)((char *)e + offset);
-      if (bb_sese *t_sese = BB_GET_SESE (target))
-	{
-	  if (t_sese->node < sese->node + dir
-	      && !(dir < 0 && sese->parent == t_sese->node))
-	    /* Non-parental ancestor node - backedge from me.  */
-	    sese->push (pseudo_node_t (target, usd * t_sese->dir));
-	}
-      else
-	{
-	  /* back edge to entry node */
-	  sese->push (pseudo_node_t (0, 0));
-	}
-    }
-  
- /* If this node leads directly or indirectly to a no-return region of
-     the graph, then fake a backedge to entry node.  */
-  if (!sese->brackets.length () || !edges || !edges->length ())
-    {
-      hi_back = 0;
-      node_back = pseudo_node_t (0, 0);
-      sese->push (node_back);
-    }
-
-  /* Record the highest reaching backedge from us or a descendant.  */
-  sese->high = hi_back < hi_child ? node_back : node_child;
-
-  if (num_children > 1)
-    {
-      /* There is more than one child -- this is a Y shaped piece of
-	 spanning tree.  We have to insert a fake backedge from this
-	 node to the highest ancestor reached by not-the-highest
-	 reaching child.  Note that there may be multiple children
-	 with backedges to the same highest node.  That's ok and we
-	 insert the edge to that highest node.  */
-      hi_child = depth;
-      if (dir < 0 && child)
-	{
-	  node_child = sese->high;
-	  hi_child = node_child.second;
-	  if (node_child.first)
-	    hi_child += BB_GET_SESE (node_child.first)->node;
-	}
-
-      FOR_EACH_EDGE (e, ei, edges)
-	{
-	  basic_block target = *(basic_block *)((char *)e + offset);
-
-	  if (target == child)
-	    /* Ignore the highest child. */
-	    continue;
-
-	  bb_sese *t_sese = BB_GET_SESE (target);
-	  if (!t_sese)
-	    continue;
-	  if (t_sese->parent != sese->node)
-	    /* Not a child. */
-	    continue;
-
-	  /* Compare its hi value.  */
-	  int t_hi = t_sese->high.second;
-
-	  if (basic_block child_hi_block = t_sese->high.first)
-	    t_hi += BB_GET_SESE (child_hi_block)->node;
-
-	  if (hi_child > t_hi)
-	    {
-	      hi_child = t_hi;
-	      node_child = t_sese->high;
-	    }
-	}
-      
-      sese->push (node_child);
-    }
-}
-
-
-/* DFS walk of BB graph.  Color node BLOCK according to COLORING then
-   proceed to successors.  Set SESE entry and exit nodes of
-   REGIONS.  */
-
-static void
-nvptx_sese_color (auto_vec<unsigned> &color_counts, bb_pair_vec_t &regions,
-		  basic_block block, int coloring)
-{
-  bb_sese *sese = BB_GET_SESE (block);
-
-  if (block->flags & BB_VISITED)
-    {
-      /* If we've already encountered this block, either we must not
-	 be coloring, or it must have been colored the current color.  */
-      gcc_assert (coloring < 0 || (sese && coloring == sese->color));
-      return;
-    }
-  
-  block->flags |= BB_VISITED;
-
-  if (sese)
-    {
-      if (coloring < 0)
-	{
-	  /* Start coloring a region.  */
-	  regions[sese->color].first = block;
-	  coloring = sese->color;
-	}
-
-      if (!--color_counts[sese->color] && sese->color == coloring)
-	{
-	  /* Found final block of SESE region.  */
-	  regions[sese->color].second = block;
-	  coloring = -1;
-	}
-      else
-	/* Color the node, so we can assert on revisiting the node
-	   that the graph is indeed SESE.  */
-	sese->color = coloring;
-    }
-  else
-    /* Fallen off the subgraph, we cannot be coloring.  */
-    gcc_assert (coloring < 0);
-
-  /* Walk each successor block.  */
-  if (block->succs && block->succs->length ())
-    {
-      edge e;
-      edge_iterator ei;
-      
-      FOR_EACH_EDGE (e, ei, block->succs)
-	nvptx_sese_color (color_counts, regions, e->dest, coloring);
-    }
-  else
-    gcc_assert (coloring < 0);
-}
-
-/* Find minimal set of SESE regions covering BLOCKS.  REGIONS might
-   end up with NULL entries in it.  */
-
-static void
-nvptx_find_sese (auto_vec<basic_block> &blocks, bb_pair_vec_t &regions)
-{
-  basic_block block;
-  int ix;
-
-  /* First clear each BB of the whole function.  */ 
-  FOR_ALL_BB_FN (block, cfun)
-    {
-      block->flags &= ~BB_VISITED;
-      BB_SET_SESE (block, 0);
-    }
-
-  /* Mark blocks in the function that are in this graph.  */
-  for (ix = 0; blocks.iterate (ix, &block); ix++)
-    block->flags |= BB_VISITED;
-
-  /* Counts of nodes assigned to each color.  There cannot be more
-     colors than blocks (and hopefully there will be fewer).  */
-  auto_vec<unsigned> color_counts;
-  color_counts.reserve (blocks.length ());
-
-  /* Worklist of nodes in the spanning tree.  Again, there cannot be
-     more nodes in the tree than blocks (there will be fewer if the
-     CFG of blocks is disjoint).  */
-  auto_vec<basic_block> spanlist;
-  spanlist.reserve (blocks.length ());
-
-  /* Make sure every block has its cycle class determined.  */
-  for (ix = 0; blocks.iterate (ix, &block); ix++)
-    {
-      if (BB_GET_SESE (block))
-	/* We already met this block in an earlier graph solve.  */
-	continue;
-
-      if (dump_file)
-	fprintf (dump_file, "Searching graph starting at %d\n", block->index);
-      
-      /* Number the nodes reachable from block initial DFS order.  */
-      int depth = nvptx_sese_number (2, 0, +1, block, &spanlist);
-
-      /* Now walk in reverse DFS order to find cycle equivalents.  */
-      while (spanlist.length ())
-	{
-	  block = spanlist.pop ();
-	  bb_sese *sese = BB_GET_SESE (block);
-
-	  /* Do the pseudo node below.  */
-	  nvptx_sese_pseudo (block, sese, depth, +1,
-			     sese->dir > 0 ? block->succs : block->preds,
-			     (sese->dir > 0 ? offsetof (edge_def, dest)
-			      : offsetof (edge_def, src)));
-	  sese->set_color (color_counts);
-	  /* Do the pseudo node above.  */
-	  nvptx_sese_pseudo (block, sese, depth, -1,
-			     sese->dir < 0 ? block->succs : block->preds,
-			     (sese->dir < 0 ? offsetof (edge_def, dest)
-			      : offsetof (edge_def, src)));
-	}
-      if (dump_file)
-	fprintf (dump_file, "\n");
-    }
-
-  if (dump_file)
-    {
-      unsigned count;
-      const char *comma = "";
-      
-      fprintf (dump_file, "Found %d cycle equivalents\n",
-	       color_counts.length ());
-      for (ix = 0; color_counts.iterate (ix, &count); ix++)
-	{
-	  fprintf (dump_file, "%s%d[%d]={", comma, ix, count);
-
-	  comma = "";
-	  for (unsigned jx = 0; blocks.iterate (jx, &block); jx++)
-	    if (BB_GET_SESE (block)->color == ix)
-	      {
-		block->flags |= BB_VISITED;
-		fprintf (dump_file, "%s%d", comma, block->index);
-		comma=",";
-	      }
-	  fprintf (dump_file, "}");
-	  comma = ", ";
-	}
-      fprintf (dump_file, "\n");
-   }
-  
-  /* Now we've colored every block in the subgraph.  We now need to
-     determine the minimal set of SESE regions that cover that
-     subgraph.  Do this with a DFS walk of the complete function.
-     During the walk we're either 'looking' or 'coloring'.  When we
-     reach the last node of a particular color, we stop coloring and
-     return to looking.  */
-
-  /* There cannot be more SESE regions than colors.  */
-  regions.reserve (color_counts.length ());
-  for (ix = color_counts.length (); ix--;)
-    regions.quick_push (bb_pair_t (0, 0));
-
-  for (ix = 0; blocks.iterate (ix, &block); ix++)
-    block->flags &= ~BB_VISITED;
-
-  nvptx_sese_color (color_counts, regions, ENTRY_BLOCK_PTR_FOR_FN (cfun), -1);
-
-  if (dump_file)
-    {
-      const char *comma = "";
-      int len = regions.length ();
-      
-      fprintf (dump_file, "SESE regions:");
-      for (ix = 0; ix != len; ix++)
-	{
-	  basic_block from = regions[ix].first;
-	  basic_block to = regions[ix].second;
-
-	  if (from)
-	    {
-	      fprintf (dump_file, "%s %d{%d", comma, ix, from->index);
-	      if (to != from)
-		fprintf (dump_file, "->%d", to->index);
-
-	      int color = BB_GET_SESE (from)->color;
-
-	      /* Print the blocks within the region (excluding ends).  */
-	      FOR_EACH_BB_FN (block, cfun)
-		{
-		  bb_sese *sese = BB_GET_SESE (block);
-
-		  if (sese && sese->color == color
-		      && block != from && block != to)
-		    fprintf (dump_file, ".%d", block->index);
-		}
-	      fprintf (dump_file, "}");
-	    }
-	  comma = ",";
-	}
-      fprintf (dump_file, "\n\n");
-    }
-  
-  for (ix = 0; blocks.iterate (ix, &block); ix++)
-    delete BB_GET_SESE (block);
-}
-
-#undef BB_SET_SESE
-#undef BB_GET_SESE
-
 /* Propagate live state at the start of a partitioned region.  IS_CALL
    indicates whether the propagation is for a (partitioned) call
    instruction.  BLOCK provides the live register information, and
@@ -4930,7 +4312,7 @@ nvptx_neuter_pars (parallel *par, unsigned modes, unsigned outer)
 	  /* Neuter whole SESE regions.  */
 	  bb_pair_vec_t regions;
 
-	  nvptx_find_sese (par->blocks, regions);
+	  omp_find_sese (par->blocks, regions);
 	  len = regions.length ();
 	  for (ix = 0; ix != len; ix++)
 	    {
diff --git a/gcc/omp-sese.c b/gcc/omp-sese.c
index 63aac1029be..ec9cacdf092 100644
--- a/gcc/omp-sese.c
+++ b/gcc/omp-sese.c
@@ -52,20 +52,21 @@
 #include "tree-cfg.h"
 #include "omp-offload.h"
 #include "attribs.h"
+#include "omp-sese.h"
 
 /* Loop structure of the function.  The entire function is described as
    a NULL loop.  */
 
-struct parallel
+struct parallel_g
 {
   /* Parent parallel.  */
-  parallel *parent;
+  parallel_g *parent;
 
   /* Next sibling parallel.  */
-  parallel *next;
+  parallel_g *next;
 
   /* First child parallel.  */
-  parallel *inner;
+  parallel_g *inner;
 
   /* Partitioning mask of the parallel.  */
   unsigned mask;
@@ -95,14 +96,14 @@ struct parallel
   tree receiver_decl;
 
 public:
-  parallel (parallel *parent, unsigned mode);
-  ~parallel ();
+  parallel_g (parallel_g *parent, unsigned mode);
+  ~parallel_g ();
 };
 
 /* Constructor links the new parallel into it's parent's chain of
    children.  */
 
-parallel::parallel (parallel *parent_, unsigned mask_)
+parallel_g::parallel_g (parallel_g *parent_, unsigned mask_)
   :parent (parent_), next (0), inner (0), mask (mask_), inner_mask (0)
 {
   forked_block = join_block = 0;
@@ -120,7 +121,7 @@ parallel::parallel (parallel *parent_, unsigned mask_)
     }
 }
 
-parallel::~parallel ()
+parallel_g::~parallel_g ()
 {
   delete inner;
   delete next;
@@ -205,7 +206,6 @@ omp_sese_split_blocks (bb_stmt_map_t *map)
 	    {
 	      enum ifn_unique_kind k = ((enum ifn_unique_kind)
 		TREE_INT_CST_LOW (gimple_call_arg (stmt, 0)));
-	      gcall *call = as_a <gcall *> (stmt);
 
 	      if (k == IFN_UNIQUE_OACC_JOIN)
 		worklist.safe_push (stmt);
@@ -343,7 +343,7 @@ mask_name (unsigned mask)
 /* Dump this parallel and all its inner parallels.  */
 
 static void
-omp_sese_dump_pars (parallel *par, unsigned depth)
+omp_sese_dump_pars (parallel_g *par, unsigned depth)
 {
   fprintf (dump_file, "%u: mask %d (%s) head=%d, tail=%d\n",
 	   depth, par->mask, mask_name (par->mask),
@@ -367,8 +367,8 @@ omp_sese_dump_pars (parallel *par, unsigned depth)
    terminate a loop structure.  Add this block to the current loop,
    and then walk successor blocks.   */
 
-static parallel *
-omp_sese_find_par (bb_stmt_map_t *map, parallel *par, basic_block block)
+static parallel_g *
+omp_sese_find_par (bb_stmt_map_t *map, parallel_g *par, basic_block block)
 {
   if (block->flags & BB_VISITED)
     return par;
@@ -387,7 +387,7 @@ omp_sese_find_par (bb_stmt_map_t *map, parallel *par, basic_block block)
 	{
 	  /* A single block that is forced to be at the maximum partition
 	     level.  Make a singleton par for it.  */
-	  par = new parallel (par, GOMP_DIM_MASK (GOMP_DIM_GANG)
+	  par = new parallel_g (par, GOMP_DIM_MASK (GOMP_DIM_GANG)
 				   | GOMP_DIM_MASK (GOMP_DIM_WORKER)
 				   | GOMP_DIM_MASK (GOMP_DIM_VECTOR));
 	  par->forked_block = block;
@@ -415,7 +415,7 @@ omp_sese_find_par (bb_stmt_map_t *map, parallel *par, basic_block block)
 		    = TREE_INT_CST_LOW (gimple_call_arg (call, 2));
 		  unsigned mask = (dim >= 0) ? GOMP_DIM_MASK (dim) : 0;
 
-		  par = new parallel (par, mask);
+		  par = new parallel_g (par, mask);
 		  par->forked_block = block;
 		  par->forked_stmt = final_stmt;
 		  par->fork_stmt = stmt;
@@ -453,7 +453,7 @@ omp_sese_find_par (bb_stmt_map_t *map, parallel *par, basic_block block)
     par->blocks.safe_push (block);
   else
     /* This must be the entry block.  Create a NULL parallel.  */
-    par = new parallel (0, 0);
+    par = new parallel_g (0, 0);
 
 walk_successors:
   /* Walk successor blocks.  */
@@ -472,7 +472,7 @@ walk_successors:
    speeds up the discovery.  We rely on the BB visited flag having
    been cleared when splitting blocks.  */
 
-static parallel *
+static parallel_g *
 omp_sese_discover_pars (bb_stmt_map_t *map)
 {
   basic_block block;
@@ -485,7 +485,7 @@ omp_sese_discover_pars (bb_stmt_map_t *map)
   block = ENTRY_BLOCK_PTR_FOR_FN (cfun);
   block->flags &= ~BB_VISITED;
 
-  parallel *par = omp_sese_find_par (map, 0, block);
+  parallel_g *par = omp_sese_find_par (map, 0, block);
 
   if (dump_file)
     {
@@ -498,7 +498,7 @@ omp_sese_discover_pars (bb_stmt_map_t *map)
 }
 
 static void
-populate_single_mode_bitmaps (parallel *par, bitmap worker_single,
+populate_single_mode_bitmaps (parallel_g *par, bitmap worker_single,
 			      bitmap vector_single, unsigned outer_mask,
 			      int depth)
 {
@@ -583,7 +583,7 @@ install_var_field (tree var, tree record_type)
 typedef hash_set<tree> propagation_set;
 
 static void
-find_ssa_names_to_propagate (parallel *par, unsigned outer_mask,
+find_ssa_names_to_propagate (parallel_g *par, unsigned outer_mask,
 			     bitmap worker_single, bitmap vector_single,
 			     vec<propagation_set *> *prop_set)
 {
@@ -685,7 +685,7 @@ find_partitioned_var_uses_1 (tree *node, int *, void *data)
 }
 
 static void
-find_partitioned_var_uses (parallel *par, unsigned outer_mask,
+find_partitioned_var_uses (parallel_g *par, unsigned outer_mask,
 			   hash_set<tree> *partitioned_var_uses)
 {
   unsigned mask = outer_mask | par->mask;
@@ -713,7 +713,7 @@ find_partitioned_var_uses (parallel *par, unsigned outer_mask,
 }
 
 static void
-find_local_vars_to_propagate (parallel *par, unsigned outer_mask,
+find_local_vars_to_propagate (parallel_g *par, unsigned outer_mask,
 			      hash_set<tree> *partitioned_var_uses,
 			      vec<propagation_set *> *prop_set)
 {
@@ -852,8 +852,8 @@ worker_single_simple (basic_block from, basic_block to,
 	  if (def_escapes_block->contains (var))
 	    {
 	      gphi *join_phi = create_phi_node (NULL_TREE, skip_block);
-	      tree res = create_new_def_for (var, join_phi,
-					     gimple_phi_result_ptr (join_phi));
+	      create_new_def_for (var, join_phi,
+				  gimple_phi_result_ptr (join_phi));
 	      add_phi_arg (join_phi, var, e, UNKNOWN_LOCATION);
 
 	      tree neutered_def = copy_ssa_name (var, NULL);
@@ -1166,8 +1166,9 @@ worker_single_copy (basic_block from, basic_block to,
 }
 
 static void
-neuter_worker_single (parallel *par, unsigned outer_mask, bitmap worker_single,
-		      bitmap vector_single, vec<propagation_set *> *prop_set,
+neuter_worker_single (parallel_g *par, unsigned outer_mask,
+		      bitmap worker_single, bitmap vector_single,
+		      vec<propagation_set *> *prop_set,
 		      hash_set<tree> *partitioned_var_uses)
 {
   unsigned mask = outer_mask | par->mask;
@@ -1332,7 +1333,7 @@ oacc_do_neutering (void)
 	}
     }
 
-  parallel *par = omp_sese_discover_pars (&bb_stmt_map);
+  parallel_g *par = omp_sese_discover_pars (&bb_stmt_map);
   populate_single_mode_bitmaps (par, worker_single, vector_single, mask, 0);
 
   basic_block bb;
@@ -1461,10 +1462,6 @@ oacc_do_neutering (void)
    This way we end up with coloring the inside of non-trivial SESE
    regions with the color of that region.  */
 
-/* A pair of BBs.  We use this to represent SESE regions.  */
-typedef std::pair<basic_block, basic_block> bb_pair_t;
-typedef auto_vec<bb_pair_t> bb_pair_vec_t;
-
 /* A node in the undirected CFG.  The discriminator SECOND indicates just
    above or just below the BB idicated by FIRST.  */
 typedef std::pair<basic_block, int> pseudo_node_t;
@@ -1827,7 +1824,7 @@ omp_sese_pseudo (basic_block me, bb_sese *sese, int depth, int dir,
 
 static void
 omp_sese_color (auto_vec<unsigned> &color_counts, bb_pair_vec_t &regions,
-		  basic_block block, int coloring)
+		basic_block block, int coloring)
 {
   bb_sese *sese = BB_GET_SESE (block);
 
@@ -1881,7 +1878,7 @@ omp_sese_color (auto_vec<unsigned> &color_counts, bb_pair_vec_t &regions,
 /* Find minimal set of SESE regions covering BLOCKS.  REGIONS might
    end up with NULL entries in it.  */
 
-static void
+void
 omp_find_sese (auto_vec<basic_block> &blocks, bb_pair_vec_t &regions)
 {
   basic_block block;
diff --git a/gcc/omp-sese.h b/gcc/omp-sese.h
index 57290eb9d65..0b82a2417eb 100644
--- a/gcc/omp-sese.h
+++ b/gcc/omp-sese.h
@@ -21,6 +21,12 @@ along with GCC; see the file COPYING3.  If not see
 #ifndef GCC_OMP_SESE_H
 #define GCC_OMP_SESE_H
 
+/* A pair of BBs.  We use this to represent SESE regions.  */
+typedef std::pair<basic_block, basic_block> bb_pair_t;
+typedef auto_vec<bb_pair_t> bb_pair_vec_t;
+
+extern void omp_find_sese (auto_vec<basic_block> &blocks,
+			   bb_pair_vec_t &regions);
 extern void oacc_do_neutering (void);
 
 #endif