* tree-ssa-loop-niter.c (number_of_iterations_cond): Split into several

	functions.
	(number_of_iterations_ne, number_of_iterations_lt_to_ne,
	assert_no_overflow_lt, assert_loop_rolls_lt, number_of_iterations_lt,
	number_of_iterations_le): New functions.
	(number_of_iterations_special): Removed.
	(number_of_iterations_exit): Do not use number_of_iterations_special.
	* tree.c (unsigned_type_for): Always return integer type.

	* gcc.dg/tree-ssa/pr19210-1.c: Update outcome.  Add new test loop.
	* gcc.dg/tree-ssa/pr19210-2.c: Ditto.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@109702 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 9 insertions, 1 deletions

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr19210-2.c b/gcc/testsuite/gcc.dg/tree-ssa/pr19210-2.c
index 498c6588975..9116e97ec4f 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/pr19210-2.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr19210-2.c
@@ -12,7 +12,15 @@ f (unsigned n)
   for(k = 5;k <= n;k += 4) /* { dg-warning "assuming.*not overflow" } */
     g();
 
-  for(k = 5;k <= n;k += 5) /* { dg-warning "assuming.*not overflow" } */
+  /* We used to get warning for this loop.  However, since then # of iterations
+     analysis improved, and we can now prove that this loop does not verflow.
+     This is because the only case when it would overflow is if n = ~0 (since
+     ~0 is divisible by 5), and this cannot be the case, since when we got
+     here, the previous loop exited, thus there exists k > n.  */
+  for(k = 5;k <= n;k += 5)
+    g();
+
+  for(k = 4;k <= n;k += 5) /* { dg-warning "assuming.*not overflow" } */
     g();
 
   for(k = 15;k >= n;k--) /* { dg-warning "assuming.*not infinite" } */