2014-08-14 Richard Biener <rguenther@suse.de>

	PR tree-optimization/62081
	* tree-ssa-loop.c (pass_fix_loops): New pass.
	(pass_tree_loop::gate):  Do not fixup loops here.
	* tree-pass.h (make_pass_fix_loops): Declare.
	* passes.def: Schedule pass_fix_loops before GIMPLE loop passes.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@213961 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 50 insertions, 3 deletions

diff --git a/gcc/tree-ssa-loop.c b/gcc/tree-ssa-loop.c
index d0c9980b35b..7d1f68e38b5 100644
--- a/gcc/tree-ssa-loop.c
+++ b/gcc/tree-ssa-loop.c
@@ -43,6 +43,56 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-vectorizer.h"
 
 
+/* A pass making sure loops are fixed up.  */
+
+namespace {
+
+const pass_data pass_data_fix_loops =
+{
+  GIMPLE_PASS, /* type */
+  "fix_loops", /* name */
+  OPTGROUP_LOOP, /* optinfo_flags */
+  TV_TREE_LOOP, /* tv_id */
+  PROP_cfg, /* properties_required */
+  0, /* properties_provided */
+  0, /* properties_destroyed */
+  0, /* todo_flags_start */
+  0, /* todo_flags_finish */
+};
+
+class pass_fix_loops : public gimple_opt_pass
+{
+public:
+  pass_fix_loops (gcc::context *ctxt)
+    : gimple_opt_pass (pass_data_fix_loops, ctxt)
+  {}
+
+  /* opt_pass methods: */
+  virtual bool gate (function *) { return flag_tree_loop_optimize; }
+
+  virtual unsigned int execute (function *fn);
+}; // class pass_fix_loops
+
+unsigned int
+pass_fix_loops::execute (function *)
+{
+  if (loops_state_satisfies_p (LOOPS_NEED_FIXUP))
+    {
+      calculate_dominance_info (CDI_DOMINATORS);
+      fix_loop_structure (NULL);
+    }
+  return 0;
+}
+
+} // anon namespace
+
+gimple_opt_pass *
+make_pass_fix_loops (gcc::context *ctxt)
+{
+  return new pass_fix_loops (ctxt);
+}
+
+
 /* Gate for loop pass group.  The group is controlled by -ftree-loop-optimize
    but we also avoid running it when the IL doesn't contain any loop.  */
 
@@ -57,9 +107,6 @@ gate_loop (function *fn)
   if (!loops_for_fn (fn))
     return true;
 
-  /* Make sure to drop / re-discover loops when necessary.  */
-  if (loops_state_satisfies_p (LOOPS_NEED_FIXUP))
-    fix_loop_structure (NULL);
   return number_of_loops (fn) > 1;
 }