gimple.def (GIMPLE_ASSIGN): Fix incorrect information in the comment.

	* gimple.def (GIMPLE_ASSIGN): Fix incorrect information in the
	comment.  Add that if LHS is not a gimple register, then RHS1 has
	to be a single object (GIMPLE_SINGLE_RHS).

Co-Authored-By: Adam Nemet <anemet@caviumnetworks.com>

From-SVN: r147209

gcc/ChangeLog

+2009-05-06  Richard Guenther  <rguenther@suse.de>
+	    Adam Nemet  <anemet@caviumnetworks.com>
+
+	* gimple.def (GIMPLE_ASSIGN): Fix incorrect information in the
+	comment.  Add that if LHS is not a gimple register, then RHS1 has
+	to be a single object (GIMPLE_SINGLE_RHS).
+
 2009-05-06  Adam Nemet  <anemet@caviumnetworks.com>
 
 	* expr.c (get_def_for_expr): Move it up in the file.

gcc/gimple.def

@@ -102,16 +102,17 @@ DEFGSCODE(GIMPLE_CHANGE_DYNAMIC_TYPE, "gimple_change_dynamic_type",
 
    SUBCODE is the tree code for the expression computed by the RHS of the
    assignment.  It must be one of the tree codes accepted by
-   get_gimple_rhs_class.
+   get_gimple_rhs_class.  If LHS is not a gimple register according to
+   is_gimple_reg, SUBCODE must be of class GIMPLE_SINGLE_RHS.
 
    LHS is the operand on the LHS of the assignment.  It must be a tree node
-   accepted by is_gimple_operand.
+   accepted by is_gimple_lvalue.
 
-   RHS1 is the first operand on the RHS of the assignment. It must be a tree
-   node accepted by is_gimple_operand.
+   RHS1 is the first operand on the RHS of the assignment.  It must always be
+   present.  It must be a tree node accepted by is_gimple_val.
 
-   RHS2 is the second operand on the RHS of the assignemnt. It must be a tree
-   node accepted by is_gimple_operand.  This argument exists only if SUBCODE is
+   RHS2 is the second operand on the RHS of the assignment.  It must be a tree
+   node accepted by is_gimple_val.  This argument exists only if SUBCODE is
    of class GIMPLE_BINARY_RHS.  */
 DEFGSCODE(GIMPLE_ASSIGN, "gimple_assign",
 	  struct gimple_statement_with_memory_ops)