Don't cons with #'mapcar calls where the result is discarded, decide on mapc-internal at compile time if the Common Lisp functionality is not being used. 2009-10-12 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (mapc): New compiler macro, use mapc-internal at compile time if we're not using the Common Lisp functionality. * bytecomp.el (byte-compile-mapcar, byte-compile-maplist): New. If the return value of mapcar is being discarded, compile it to a mapc-internal call instead, and warn, because the programmer probably can't rely on always being compiled by an XEmacs that does this. Similarly for maplist and mapl; and use byte-compile-funarg for map, mapl, mapcan, mapcon.