re PR target/83158 (gcc.target/i386/pr78057.c fail)

2017-11-28  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/83158
	* tree-vrp.c (intersect_ranges): Prefer ~[0, 0] in a few more
	cases.

From-SVN: r255190

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index fe6b562427e7a7d74b5db508387b4fe53d7b9ea6..7f5e6cb4573516d47dc828a923c84aea8b44a1cc 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2017-11-28  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/83158
+       * tree-vrp.c (intersect_ranges): Prefer ~[0, 0] in a few more
+       cases.
+
 2017-11-28  Segher Boessenkool  <segher@kernel.crashing.org>
 
        PR 81288/target

diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index 5f9baa3e7ff2bc59f3f6fac8fcb5ddda2794cfcb..1217f8259b70d04d83a1823f61c1394d20044982 100644 (file)
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -6021,11 +6021,14 @@ intersect_ranges (enum value_range_type *vr0type,
                   && vrp_val_is_max (vr1max))
            ;
          /* Choose the anti-range if it is ~[0,0], that range is special
-            enough to special case when vr1's range is relatively wide.  */
+            enough to special case when vr1's range is relatively wide.
+            At least for types bigger than int - this covers pointers
+            and arguments to functions like ctz.  */
          else if (*vr0min == *vr0max
                   && integer_zerop (*vr0min)
-                  && (TYPE_PRECISION (TREE_TYPE (*vr0min))
-                      == TYPE_PRECISION (ptr_type_node))
+                  && ((TYPE_PRECISION (TREE_TYPE (*vr0min))
+                       >= TYPE_PRECISION (integer_type_node))
+                      || POINTER_TYPE_P (TREE_TYPE (*vr0min)))
                   && TREE_CODE (vr1max) == INTEGER_CST
                   && TREE_CODE (vr1min) == INTEGER_CST
                   && (wi::clz (wi::to_wide (vr1max) - wi::to_wide (vr1min))