* tree-ssa-loop-niter.c (idx_infer_loop_bounds): Add and use

	argument "reliable".
	(infer_loop_bounds_from_ref, infer_loop_bounds_from_array):
	Add argument "reliable".  Propagate it through calls.
	(infer_loop_bounds_from_undefined):  Derive number of iterations
	estimates from references in blocks that do not dominate loop latch.
	(gcov_type_to_double_int): New function.
	(estimate_numbers_of_iterations_loop): Use gcov_type_to_double_int
	and expected_loop_iterations_unbounded.
	* cfgloopanal.c (expected_loop_iterations_unbounded): New function.
	(expected_loop_iterations): Use expected_loop_iterations_unbounded.
	* tree-data-ref.c (estimated_loop_iterations): Export.
	(get_references_in_stmt): Fix -- do not return addresses of local
	objects.
	* cfgloop.h (expected_loop_iterations_unbounded,
	estimated_loop_iterations): Declare.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@123630 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 17 insertions, 7 deletions

diff --git a/gcc/cfgloopanal.c b/gcc/cfgloopanal.c
index 5a9189787ea..4612ab8f1a1 100644
--- a/gcc/cfgloopanal.c
+++ b/gcc/cfgloopanal.c
@@ -423,11 +423,12 @@ average_num_loop_insns (struct loop *loop)
   return ninsns;
 }
 
-/* Returns expected number of LOOP iterations.
-   Compute upper bound on number of iterations in case they do not fit integer
-   to help loop peeling heuristics.  Use exact counts if at all possible.  */
-unsigned
-expected_loop_iterations (const struct loop *loop)
+/* Returns expected number of iterations of LOOP, according to
+   measured or guessed profile.  No bounding is done on the
+   value.  */
+
+gcov_type
+expected_loop_iterations_unbounded (const struct loop *loop)
 {
   edge e;
   edge_iterator ei;
@@ -450,8 +451,7 @@ expected_loop_iterations (const struct loop *loop)
       else
 	expected = (count_latch + count_in - 1) / count_in;
 
-      /* Avoid overflows.  */
-      return (expected > REG_BR_PROB_BASE ? REG_BR_PROB_BASE : expected);
+      return expected;
     }
   else
     {
@@ -473,6 +473,16 @@ expected_loop_iterations (const struct loop *loop)
     }
 }
 
+/* Returns expected number of LOOP iterations.  The returned value is bounded
+   by REG_BR_PROB_BASE.  */
+
+unsigned
+expected_loop_iterations (const struct loop *loop)
+{
+  gcov_type expected = expected_loop_iterations_unbounded (loop);
+  return (expected > REG_BR_PROB_BASE ? REG_BR_PROB_BASE : expected);
+}
+
 /* Returns the maximum level of nesting of subloops of LOOP.  */
 
 unsigned