Index: /trunk/ccl/compiler/PPC/ppc2.lisp
===================================================================
--- /trunk/ccl/compiler/PPC/ppc2.lisp	(revision 5909)
+++ /trunk/ccl/compiler/PPC/ppc2.lisp	(revision 5910)
@@ -8249,5 +8249,7 @@
                (! set-double-c-arg df nextarg)            
                (push (cons :double-float nextarg) fp-loads)
-               (incf nextarg)))
+               (target-word-size-case
+                (32 (incf nextarg))
+                (64))))
             (:single-float
              (let* ((sf ($ ppc::fp1 :class :fpr :mode :single-float)))