+
+/* Build a VEC_PERM_EXPR if V0, V1 and MASK are not error_mark_nodes
+ and have vector types, V0 has the same type as V1, and the number of
+ elements of V0, V1, MASK is the same.
+
+ In case V1 is a NULL_TREE it is assumed that __builtin_shuffle was
+ called with two arguments. In this case implementation passes the
+ first argument twice in order to share the same tree code. This fact
+ could enable the mask-values being twice the vector length. This is
+ an implementation accident and this semantics is not guaranteed to
+ the user. */
+tree
+c_build_vec_perm_expr (location_t loc, tree v0, tree v1, tree mask)
+{
+ tree ret;
+ bool wrap = true;
+ bool maybe_const = false;
+ bool two_arguments = false;
+
+ if (v1 == NULL_TREE)
+ {
+ two_arguments = true;
+ v1 = v0;
+ }
+
+ if (v0 == error_mark_node || v1 == error_mark_node
+ || mask == error_mark_node)
+ return error_mark_node;
+
+ if (TREE_CODE (TREE_TYPE (mask)) != VECTOR_TYPE
+ || TREE_CODE (TREE_TYPE (TREE_TYPE (mask))) != INTEGER_TYPE)
+ {
+ error_at (loc, "__builtin_shuffle last argument must "
+ "be an integer vector");
+ return error_mark_node;
+ }
+
+ if (TREE_CODE (TREE_TYPE (v0)) != VECTOR_TYPE
+ || TREE_CODE (TREE_TYPE (v1)) != VECTOR_TYPE)
+ {
+ error_at (loc, "__builtin_shuffle arguments must be vectors");
+ return error_mark_node;
+ }
+
+ if (TYPE_MAIN_VARIANT (TREE_TYPE (v0)) != TYPE_MAIN_VARIANT (TREE_TYPE (v1)))
+ {
+ error_at (loc, "__builtin_shuffle argument vectors must be of "
+ "the same type");
+ return error_mark_node;
+ }
+
+ if (TYPE_VECTOR_SUBPARTS (TREE_TYPE (v0))
+ != TYPE_VECTOR_SUBPARTS (TREE_TYPE (mask))
+ && TYPE_VECTOR_SUBPARTS (TREE_TYPE (v1))
+ != TYPE_VECTOR_SUBPARTS (TREE_TYPE (mask)))
+ {
+ error_at (loc, "__builtin_shuffle number of elements of the "
+ "argument vector(s) and the mask vector should "
+ "be the same");
+ return error_mark_node;
+ }
+
+ if (GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (v0))))
+ != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (mask)))))
+ {
+ error_at (loc, "__builtin_shuffle argument vector(s) inner type "
+ "must have the same size as inner type of the mask");
+ return error_mark_node;
+ }
+
+ /* Avoid C_MAYBE_CONST_EXPRs inside VEC_PERM_EXPR. */
+ v0 = c_fully_fold (v0, false, &maybe_const);
+ wrap &= maybe_const;
+
+ if (two_arguments)
+ v1 = v0 = save_expr (v0);
+ else
+ {
+ v1 = c_fully_fold (v1, false, &maybe_const);
+ wrap &= maybe_const;
+ }
+
+ mask = c_fully_fold (mask, false, &maybe_const);
+ wrap &= maybe_const;
+
+ ret = build3_loc (loc, VEC_PERM_EXPR, TREE_TYPE (v0), v0, v1, mask);
+
+ if (!wrap)
+ ret = c_wrap_maybe_const (ret, true);
+
+ return ret;
+}