loop-unswitch.c (unswitch_single_loop): Use estimated_loop_iterations_int to prevent unswitching when...

	* loop-unswitch.c (unswitch_single_loop): Use
	estimated_loop_iterations_int to prevent unswitching when loop
	is known to not roll.
	* tree-ssa-loop-niter.c (estimated_loop_iterations): Do not segfault
	when SCEV is not initialized.
	(max_loop_iterations): Likewise.
	* tree-ssa-loop-unswitch.c (tree_ssa_unswitch_loops): Use
	estimated_loop_iterations_int to prevent unswithcing when
	loop is known to not roll.
	* tree-scalar-evolution.c (scev_initialized_p): New function.
	* tree-scalar-evolution.h (scev_initialized_p): Likewise.
	* loop-unroll.c (decide_peel_once_rolling): Use
	max_loop_iterations_int.
	(unroll_loop_constant_iterations): Update
	nb_iterations_upper_bound and nb_iterations_estimate.
	(decide_unroll_runtime_iterations): Use
	estimated_loop_iterations or max_loop_iterations;
	(unroll_loop_runtime_iterations): fix profile updating.
	(decide_peel_simple): Use estimated_loop_iterations
	and max_loop_iterations.
	(decide_unroll_stupid): Use estimated_loop_iterations
	ad max_loop_iterations.
	* loop-doloop.c (doloop_modify): Use max_loop_iterations_int.
	(doloop_optimize): Likewise.
	* loop-iv.c (iv_number_of_iterations): Use record_niter_bound.
	(find_simple_exit): Likewise.
	* cfgloop.h (struct niter_desc): Remove niter_max.

From-SVN: r192219

1 files changed, 20 insertions, 3 deletions

diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c
index 84ae610..cdcdb5c 100644
--- a/gcc/tree-ssa-loop-niter.c
+++ b/gcc/tree-ssa-loop-niter.c
@@ -3012,9 +3012,23 @@ estimate_numbers_of_iterations_loop (struct loop *loop)
 bool
 estimated_loop_iterations (struct loop *loop, double_int *nit)
 {
-  estimate_numbers_of_iterations_loop (loop);
+  /* When SCEV information is available, try to update loop iterations
+     estimate.  Otherwise just return whatever we recorded earlier.  */
+  if (scev_initialized_p ())
+    estimate_numbers_of_iterations_loop (loop);
+
+  /* Even if the bound is not recorded, possibly we can derrive one from
+     profile.  */
   if (!loop->any_estimate)
-    return false;
+    {
+      if (loop->header->count)
+	{
+          *nit = gcov_type_to_double_int
+		   (expected_loop_iterations_unbounded (loop) + 1);
+	  return true;
+	}
+      return false;
+    }
 
   *nit = loop->nb_iterations_estimate;
   return true;
@@ -3027,7 +3041,10 @@ estimated_loop_iterations (struct loop *loop, double_int *nit)
 bool
 max_loop_iterations (struct loop *loop, double_int *nit)
 {
-  estimate_numbers_of_iterations_loop (loop);
+  /* When SCEV information is available, try to update loop iterations
+     estimate.  Otherwise just return whatever we recorded earlier.  */
+  if (scev_initialized_p ())
+    estimate_numbers_of_iterations_loop (loop);
   if (!loop->any_upper_bound)
     return false;