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

6 files changed, 57 insertions, 18 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 4612ddf..0389ead 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,16 @@
+2018-11-08  Aldy Hernandez  <aldyh@redhat.com>
+
+	* 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.
+
 2018-11-09  Jan Hubicka  <jh@suse.cz>
 
 	* tree.c (fld_type_variant_equal_p): Test user align flag.
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
diff --git a/gcc/tree-ssanames.c b/gcc/tree-ssanames.c
index ff906e8..a2c2efb 100644
--- a/gcc/tree-ssanames.c
+++ b/gcc/tree-ssanames.c
@@ -398,6 +398,15 @@ set_range_info (tree name, enum value_range_kind range_type,
   set_range_info_raw (name, range_type, min, max);
 }
 
+/* Store range information for NAME from a value_range.  */
+
+void
+set_range_info (tree name, const value_range &vr)
+{
+  wide_int min = wi::to_wide (vr.min ());
+  wide_int max = wi::to_wide (vr.max ());
+  set_range_info (name, vr.kind (), min, max);
+}
 
 /* Gets range information MIN, MAX and returns enum value_range_kind
    corresponding to tree ssa_name NAME.  enum value_range_kind returned
@@ -421,6 +430,27 @@ get_range_info (const_tree name, wide_int *min, wide_int *max)
   return SSA_NAME_RANGE_TYPE (name);
 }
 
+/* Gets range information corresponding to ssa_name NAME and stores it
+   in a value_range VR.  Returns the value_range_kind.  */
+
+enum value_range_kind
+get_range_info (const_tree name, value_range &vr)
+{
+  tree min, max;
+  wide_int wmin, wmax;
+  enum value_range_kind kind = get_range_info (name, &wmin, &wmax);
+
+  if (kind == VR_VARYING || kind == VR_UNDEFINED)
+    min = max = NULL;
+  else
+    {
+      min = wide_int_to_tree (TREE_TYPE (name), wmin);
+      max = wide_int_to_tree (TREE_TYPE (name), wmax);
+    }
+  vr = value_range (kind, min, max);
+  return kind;
+}
+
 /* Set nonnull attribute to pointer NAME.  */
 
 void
diff --git a/gcc/tree-ssanames.h b/gcc/tree-ssanames.h
index 18a001a..a5ff14e 100644
--- a/gcc/tree-ssanames.h
+++ b/gcc/tree-ssanames.h
@@ -69,12 +69,11 @@ struct GTY ((variable_size)) range_info_def {
 /* Sets the value range to SSA.  */
 extern void set_range_info (tree, enum value_range_kind, const wide_int_ref &,
 			    const wide_int_ref &);
-extern void set_range_info_raw (tree, enum value_range_kind,
-				const wide_int_ref &,
-				const wide_int_ref &);
+extern void set_range_info (tree, const value_range &);
 /* Gets the value range from SSA.  */
 extern enum value_range_kind get_range_info (const_tree, wide_int *,
 					     wide_int *);
+extern enum value_range_kind get_range_info (const_tree, value_range &);
 extern void set_nonzero_bits (tree, const wide_int_ref &);
 extern wide_int get_nonzero_bits (const_tree);
 extern bool ssa_name_has_boolean_range (tree);
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index 17b0b6c..e45d788 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -743,7 +743,7 @@ vrp_bitmap_equal_p (const_bitmap b1, const_bitmap b2)
 static inline bool
 range_is_null (const value_range *vr)
 {
-  return vr->null_p ();
+  return vr->zero_p ();
 }
 
 static inline bool
diff --git a/gcc/tree-vrp.h b/gcc/tree-vrp.h
index c251329..3c870d5 100644
--- a/gcc/tree-vrp.h
+++ b/gcc/tree-vrp.h
@@ -63,7 +63,7 @@ class GTY((for_user)) value_range
 
   /* Misc methods.  */
   tree type () const;
-  bool null_p () const;
+  bool zero_p () const;
   bool may_contain_p (tree) const;
   bool singleton_p (tree *result = NULL) const;
   void deep_copy (const value_range *);
@@ -150,7 +150,7 @@ value_range::undefined_p () const
 /* Return TRUE if range is the constant zero.  */
 
 inline bool
-value_range::null_p () const
+value_range::zero_p () const
 {
   return (m_kind == VR_RANGE
 	  && integer_zerop (m_min)