Makefile.in (tree-optimize.o): Add CFGLOOP_H dependence.

	* Makefile.in (tree-optimize.o): Add CFGLOOP_H dependence.
	* cfgloop.c (flow_loop_nodes_find): Export.
	* cfgloop.h (flow_loop_nodes_find, fix_loop_structure):
	Declare.
	* cfgloopmanip.c (fix_loop_structure): New function.
	* predict.c (predict_loops): Clean up the loops information.
	* tree-cfg.c (cleanup_tree_cfg_loop): New function.
	(tree_can_merge_blocks_p, remove_bb, tree_forwarder_block_p): Respect
	loop structure.
	* tree-flow.h (cleanup_tree_cfg_loop): Declare.
	(rewrite_into_loop_closed_ssa): Declaration changed.
	* tree-loop-linear.c (linear_transform_loops): Add argument to
	rewrite_into_loop_closed_ssa call.
	* tree-ssa-loop-ch.c (copy_loop_headers): Ditto.
	* tree-ssa-loop-im.c (move_computations): Ditto.
	* tree-ssa-loop.c (tree_loop_optimizer_init): Ditto.
	* tree-vectorizer.c (vectorize_loops): Ditto.
	* tree-optimize.c: Include cfgloop.h.
	(execute_todo): Choose whether to call cleanup_tree_cfg or
	cleanup_tree_cfg_loop.
	* tree-ssa-loop-ivcanon.c (canonicalize_loop_induction_variables,
	(tree_unroll_loops_completely): Enable cleanup_tree_cfg_loop call.
	* tree-ssa-loop-unswitch.c (tree_ssa_unswitch_loops): Enable
	cleanup_tree_cfg_loop call.
	* tree-ssa-loop-manip.c (find_uses_to_rename_bb): New function.
	(find_uses_to_rename, rewrite_into_loop_closed_ssa): Support
	work on part of cfg.

From-SVN: r96232

1 files changed, 55 insertions, 0 deletions

diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
index be7ee56b..c9a8e31 100644
--- a/gcc/tree-cfg.c
+++ b/gcc/tree-cfg.c
@@ -959,6 +959,30 @@ cleanup_tree_cfg (void)
 }
 
 
+/* Cleanup cfg and repair loop structures.  */
+
+void
+cleanup_tree_cfg_loop (void)
+{
+  bitmap changed_bbs = BITMAP_ALLOC (NULL);
+
+  cleanup_tree_cfg ();
+
+  fix_loop_structure (current_loops, changed_bbs);
+  calculate_dominance_info (CDI_DOMINATORS);
+
+  /* This usually does nothing.  But sometimes parts of cfg that originally
+     were inside a loop get out of it due to edge removal (since they
+     become unreachable by back edges from latch).  */
+  rewrite_into_loop_closed_ssa (changed_bbs);
+
+  BITMAP_FREE (changed_bbs);
+
+#ifdef ENABLE_CHECKING
+  verify_loop_structure (current_loops);
+#endif
+}
+
 /* Cleanup useless labels in basic blocks.  This is something we wish
    to do early because it allows us to group case labels before creating
    the edges for the CFG, and it speeds up block statement iterators in
@@ -1277,6 +1301,11 @@ tree_can_merge_blocks_p (basic_block a, basic_block b)
 	return false;
     }
 
+  /* Protect the loop latches.  */
+  if (current_loops
+      && b->loop_father->latch == b)
+    return false;
+
   return true;
 }
 
@@ -2045,6 +2074,20 @@ remove_bb (basic_block bb)
 	}
     }
 
+  /* If we remove the header or the latch of a loop, mark the loop for
+     removal by setting its header and latch to NULL.  */
+  if (current_loops)
+    {
+      struct loop *loop = bb->loop_father;
+
+      if (loop->latch == bb
+	  || loop->header == bb)
+	{
+	  loop->latch = NULL;
+	  loop->header = NULL;
+	}
+    }
+
   /* Remove all the instructions in the block.  */
   for (i = bsi_start (bb); !bsi_end_p (i);)
     {
@@ -4099,6 +4142,18 @@ tree_forwarder_block_p (basic_block bb, bool phi_wanted)
   if (find_edge (ENTRY_BLOCK_PTR, bb))
     return false;
 
+  if (current_loops)
+    { 
+      basic_block dest;
+      /* Protect loop latches, headers and preheaders.  */
+      if (bb->loop_father->header == bb)
+	return false;
+      dest = EDGE_SUCC (bb, 0)->dest;
+ 
+      if (dest->loop_father->header == dest)
+	return false;
+    }
+
   return true;
 }