PR tree-optimization/27865

	* tree-vrp.c (adjust_range_with_scev): Do not use TYPE_{MIN,MAX}_VALUE
	for pointer types.
	* tree-scalar-evolution.c (fold_used_pointer_cast, pointer_offset_p,
	fold_used_pointer, pointer_used_p): New functions.
	(analyze_scalar_evolution_1): Use fold_used_pointer.
	* tree-chrec.c (convert_affine_scev): Convert no-op casts correctly.
	* tree-ssa-loop-ivopts.c (generic_type_for): Return integral type
	for pointers.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@116213 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 8 insertions, 2 deletions

diff --git a/gcc/tree-chrec.c b/gcc/tree-chrec.c
index f36fc9b0291..a74a49c3972 100644
--- a/gcc/tree-chrec.c
+++ b/gcc/tree-chrec.c
@@ -1162,7 +1162,10 @@ convert_affine_scev (struct loop *loop, tree type,
 	 -- must_check_src_overflow is true, and the range of TYPE is superset
 	    of the range of CT -- i.e., in all cases except if CT signed and
 	    TYPE unsigned.
-         -- both CT and TYPE have the same precision and signedness.  */
+         -- both CT and TYPE have the same precision and signedness, and we
+	    verify instead that the source does not overflow (this may be
+	    easier than verifying it for the result, as we may use the
+	    information about the semantics of overflow in CT).  */
       if (must_check_src_overflow)
 	{
 	  if (TYPE_UNSIGNED (type) && !TYPE_UNSIGNED (ct))
@@ -1172,7 +1175,10 @@ convert_affine_scev (struct loop *loop, tree type,
 	}
       else if (TYPE_UNSIGNED (ct) == TYPE_UNSIGNED (type)
 	       && TYPE_PRECISION (ct) == TYPE_PRECISION (type))
-	must_check_rslt_overflow = false;
+	{
+	  must_check_rslt_overflow = false;
+	  must_check_src_overflow = true;
+	}
       else
 	must_check_rslt_overflow = true;
     }