re PR rtl-optimization/56181 (ICE in verify_loop_structure, at cfgloop.c:1581 with -ftracer)

2013-02-08  Richard Biener  <rguenther@suse.de>

	PR middle-end/56181
	* cfgloop.h (flow_loops_find): Adjust.
	(bb_loop_header_p): Declare.
	* cfgloop.c (bb_loop_header_p): New function split out from ...
	(flow_loops_find): ... here.  Adjust function signature,
	support incremental loop structure update.
	(verify_loop_structure): Cleanup.  Verify a loop is a loop.
	* cfgloopmanip.c (fix_loop_structure): Move ...
	* loop-init.c (fix_loop_structure): ... here.
	(apply_loop_flags): Split out from ...
	(loop_optimizer_init): ... here.
	(fix_loop_structure): Use apply_loop_flags.  Use flow_loops_find
	in incremental mode, only remove dead loops here.

	* gcc.dg/torture/pr56181.c: New testcase.

From-SVN: r195879

1 files changed, 0 insertions, 156 deletions

diff --git a/gcc/cfgloopmanip.c b/gcc/cfgloopmanip.c
index c72ceda..3e53aa0 100644
--- a/gcc/cfgloopmanip.c
+++ b/gcc/cfgloopmanip.c
@@ -1760,159 +1760,3 @@ loop_version (struct loop *loop,
 
   return nloop;
 }
-
-/* The structure of loops might have changed.  Some loops might get removed
-   (and their headers and latches were set to NULL), loop exists might get
-   removed (thus the loop nesting may be wrong), and some blocks and edges
-   were changed (so the information about bb --> loop mapping does not have
-   to be correct).  But still for the remaining loops the header dominates
-   the latch, and loops did not get new subloops (new loops might possibly
-   get created, but we are not interested in them).  Fix up the mess.
-
-   If CHANGED_BBS is not NULL, basic blocks whose loop has changed are
-   marked in it.  */
-
-void
-fix_loop_structure (bitmap changed_bbs)
-{
-  basic_block bb;
-  struct loop *loop, *ploop;
-  loop_iterator li;
-  bool record_exits = false;
-  struct loop **superloop = XNEWVEC (struct loop *, number_of_loops ());
-
-  /* We need exact and fast dominance info to be available.  */
-  gcc_assert (dom_info_state (CDI_DOMINATORS) == DOM_OK);
-
-  /* Remove the old bb -> loop mapping.  Remember the depth of the blocks in
-     the loop hierarchy, so that we can recognize blocks whose loop nesting
-     relationship has changed.  */
-  FOR_EACH_BB (bb)
-    {
-      if (changed_bbs)
-	bb->aux = (void *) (size_t) loop_depth (bb->loop_father);
-      bb->loop_father = current_loops->tree_root;
-    }
-
-  if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS))
-    {
-      release_recorded_exits ();
-      record_exits = true;
-    }
-
-  /* First re-compute loop latches.  */
-  FOR_EACH_LOOP (li, loop, 0)
-    {
-      edge_iterator ei;
-      edge e, first_latch = NULL, latch = NULL;
-
-      if (!loop->header)
-	continue;
-
-      FOR_EACH_EDGE (e, ei, loop->header->preds)
-	if (dominated_by_p (CDI_DOMINATORS, e->src, loop->header))
-	  {
-	    if (!first_latch)
-	      first_latch = latch = e;
-	    else
-	      {
-		latch = NULL;
-		break;
-	      }
-	  }
-      /* If there was no latch, schedule the loop for removal.  */
-      if (!first_latch)
-	loop->header = NULL;
-      /* If there was a single latch, record it.  */
-      else if (latch)
-	loop->latch = latch->src;
-      /* Otherwise there are multiple latches which are eventually
-         disambiguated below.  */
-      else
-	loop->latch = NULL;
-    }
-
-  /* Remove the dead loops from structures.  We start from the innermost
-     loops, so that when we remove the loops, we know that the loops inside
-     are preserved, and do not waste time relinking loops that will be
-     removed later.  */
-  FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST)
-    {
-      if (loop->header)
-	continue;
-
-      while (loop->inner)
-	{
-	  ploop = loop->inner;
-	  flow_loop_tree_node_remove (ploop);
-	  flow_loop_tree_node_add (loop_outer (loop), ploop);
-	}
-
-      /* Remove the loop and free its data.  */
-      delete_loop (loop);
-    }
-
-  /* Rescan the bodies of loops, starting from the outermost ones.  We assume
-     that no optimization interchanges the order of the loops, i.e., it cannot
-     happen that L1 was superloop of L2 before and it is subloop of L2 now
-     (without explicitly updating loop information).  At the same time, we also
-     determine the new loop structure.  */
-  current_loops->tree_root->num_nodes = n_basic_blocks;
-  FOR_EACH_LOOP (li, loop, 0)
-    {
-      superloop[loop->num] = loop->header->loop_father;
-      loop->num_nodes = flow_loop_nodes_find (loop->header, loop);
-    }
-
-  /* Now fix the loop nesting.  */
-  FOR_EACH_LOOP (li, loop, 0)
-    {
-      ploop = superloop[loop->num];
-      if (ploop != loop_outer (loop))
-	{
-	  flow_loop_tree_node_remove (loop);
-	  flow_loop_tree_node_add (ploop, loop);
-	}
-    }
-  free (superloop);
-
-  /* Mark the blocks whose loop has changed.  */
-  if (changed_bbs)
-    {
-      FOR_EACH_BB (bb)
-	{
-	  if ((void *) (size_t) loop_depth (bb->loop_father) != bb->aux)
-	    bitmap_set_bit (changed_bbs, bb->index);
-
-    	  bb->aux = NULL;
-	}
-    }
-
-  if (!loops_state_satisfies_p (LOOPS_MAY_HAVE_MULTIPLE_LATCHES))
-    disambiguate_loops_with_multiple_latches ();
-
-  if (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS))
-    {
-      int cp_flags = CP_SIMPLE_PREHEADERS;
-
-      if (loops_state_satisfies_p (LOOPS_HAVE_FALLTHRU_PREHEADERS))
-	cp_flags |= CP_FALLTHRU_PREHEADERS;
-
-      create_preheaders (cp_flags);
-    }
-
-  if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES))
-    force_single_succ_latches ();
-
-  if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS))
-    mark_irreducible_loops ();
-
-  if (record_exits)
-    record_loop_exits ();
-
-  loops_state_clear (LOOPS_NEED_FIXUP);
-
-#ifdef ENABLE_CHECKING
-  verify_loop_structure ();
-#endif
-}