tree-vect-generic.c (uniform_vector_p): Move ...

2013-05-13  Marc Glisse  <marc.glisse@inria.fr>

gcc/
	* tree-vect-generic.c (uniform_vector_p): Move ...
	* tree.c (uniform_vector_p): ... here.
	* tree.h (uniform_vector_p): Declare it.
	* fold-const.c (fold_binary_loc) <shift>: Turn the second argument
	into a scalar.

gcc/testsuite/
	* gcc.dg/vector-shift-2.c: New testcase.

From-SVN: r198819

1 files changed, 48 insertions, 0 deletions

diff --git a/gcc/tree.c b/gcc/tree.c
index d93c6ae..d4e85e1 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -10133,6 +10133,54 @@ initializer_zerop (const_tree init)
     }
 }
 
+/* Check if vector VEC consists of all the equal elements and
+   that the number of elements corresponds to the type of VEC.
+   The function returns first element of the vector
+   or NULL_TREE if the vector is not uniform.  */
+tree
+uniform_vector_p (const_tree vec)
+{
+  tree first, t;
+  unsigned i;
+
+  if (vec == NULL_TREE)
+    return NULL_TREE;
+
+  gcc_assert (VECTOR_TYPE_P (TREE_TYPE (vec)));
+
+  if (TREE_CODE (vec) == VECTOR_CST)
+    {
+      first = VECTOR_CST_ELT (vec, 0);
+      for (i = 1; i < VECTOR_CST_NELTS (vec); ++i)
+	if (!operand_equal_p (first, VECTOR_CST_ELT (vec, i), 0))
+	  return NULL_TREE;
+
+      return first;
+    }
+
+  else if (TREE_CODE (vec) == CONSTRUCTOR)
+    {
+      first = error_mark_node;
+
+      FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (vec), i, t)
+        {
+          if (i == 0)
+            {
+              first = t;
+              continue;
+            }
+	  if (!operand_equal_p (first, t, 0))
+	    return NULL_TREE;
+        }
+      if (i != TYPE_VECTOR_SUBPARTS (TREE_TYPE (vec)))
+	return NULL_TREE;
+
+      return first;
+    }
+
+  return NULL_TREE;
+}
+
 /* Build an empty statement at location LOC.  */
 
 tree