re PR tree-optimization/48052 (loop not vectorized if index is "unsigned int")

	PR tree-optimization/48052
	* cfgloop.h (struct control_iv): New.
	(struct loop): New field control_ivs.
	* tree-ssa-loop-niter.c : Include "stor-layout.h".
	(number_of_iterations_lt): Set no_overflow information.
	(number_of_iterations_exit): Init control iv in niter struct.
	(record_control_iv): New.
	(estimate_numbers_of_iterations_loop): Call record_control_iv.
	(loop_exits_before_overflow): New.  Interface factored out of
	scev_probably_wraps_p.
	(scev_probably_wraps_p): Factor loop niter related code into
	loop_exits_before_overflow.
	(free_numbers_of_iterations_estimates_loop): Free control ivs.
	* tree-ssa-loop-niter.h (free_loop_control_ivs): New.

	gcc/testsuite/ChangeLog
	PR tree-optimization/48052
	* gcc.dg/tree-ssa/scev-8.c: New.
	* gcc.dg/tree-ssa/scev-9.c: New.
	* gcc.dg/tree-ssa/scev-10.c: New.
	* gcc.dg/vect/pr48052.c: New.

From-SVN: r224020

1 files changed, 11 insertions, 0 deletions

diff --git a/gcc/cfgloop.h b/gcc/cfgloop.h
index 1d84572..b011678 100644
--- a/gcc/cfgloop.h
+++ b/gcc/cfgloop.h
@@ -116,6 +116,14 @@ enum loop_estimation
   EST_LAST
 };
 
+/* The structure describing non-overflow control induction variable for
+   loop's exit edge.  */
+struct GTY ((chain_next ("%h.next"))) control_iv {
+  tree base;
+  tree step;
+  struct control_iv *next;
+};
+
 /* Structure to hold information for each natural loop.  */
 struct GTY ((chain_next ("%h.next"))) loop {
   /* Index into loops array.  */
@@ -203,6 +211,9 @@ struct GTY ((chain_next ("%h.next"))) loop {
   /* Upper bound on number of iterations of a loop.  */
   struct nb_iter_bound *bounds;
 
+  /* Non-overflow control ivs of a loop.  */
+  struct control_iv *control_ivs;
+
   /* Head of the cyclic list of the exits of the loop.  */
   struct loop_exit *exits;