gimple-fold.c (size_must_be_zero_p): Use value_range API instead of performing ad-hoc calculations.

	* gimple-fold.c (size_must_be_zero_p): Use value_range API instead
	of performing ad-hoc calculations.
	* tree-ssanames.c (set_range_info): New overloaded function
	accepting value_range &.
	(get_range_info): Same.
	* tree-ssanames.h (set_range_info_raw): Remove.
	(set_range_info): New prototype.
	(get_range_info): Same.
	* tree-vrp.h (value_range::null_p): Rename to zero_p.
	* tree-vrp.c (value_range::null_p): Same.

From-SVN: r265952

1 files changed, 9 insertions, 12 deletions

diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c
index 5468b60..67c8cfa 100644
--- a/gcc/gimple-fold.c
+++ b/gcc/gimple-fold.c
@@ -635,9 +635,8 @@ var_decl_component_p (tree var)
 	      && TREE_CODE (TREE_OPERAND (inner, 0)) == ADDR_EXPR));
 }
 
-/* If the SIZE argument representing the size of an object is in a range
-   of values of which exactly one is valid (and that is zero), return
-   true, otherwise false.  */
+/* Return TRUE if the SIZE argument, representing the size of an
+   object, is in a range of values of which exactly zero is valid.  */
 
 static bool
 size_must_be_zero_p (tree size)
@@ -648,21 +647,19 @@ size_must_be_zero_p (tree size)
   if (TREE_CODE (size) != SSA_NAME || !INTEGRAL_TYPE_P (TREE_TYPE (size)))
     return false;
 
-  wide_int min, max;
-  enum value_range_kind rtype = get_range_info (size, &min, &max);
-  if (rtype != VR_ANTI_RANGE)
-    return false;
-
   tree type = TREE_TYPE (size);
   int prec = TYPE_PRECISION (type);
 
-  wide_int wone = wi::one (prec);
-
   /* Compute the value of SSIZE_MAX, the largest positive value that
      can be stored in ssize_t, the signed counterpart of size_t.  */
   wide_int ssize_max = wi::lshift (wi::one (prec), prec - 1) - 1;
-
-  return wi::eq_p (min, wone) && wi::geu_p (max, ssize_max);
+  value_range valid_range (VR_RANGE,
+			   build_int_cst (type, 0),
+			   wide_int_to_tree (type, ssize_max));
+  value_range vr;
+  get_range_info (size, vr);
+  vr.intersect (&valid_range);
+  return vr.zero_p ();
 }
 
 /* Fold function call to builtin mem{{,p}cpy,move}.  Try to detect and