GCC build of HEAD failed for native with your patch on 2004-09-04T15:32:13Z.

[Richard Kenner]

    +2004-09-04  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
    +
    +	* fold-const.c (operand_equal_p): Remove code to allow null ARG0/1.
    +	Define locals macros OP_SAME and OP_SAME_WITH_NULL and use throughout.

It seems unlikely that this is the cause of the failure, since it's fine for
me, but it's not urgent and there is so much other breakage in the tree at
the moment (I reported three this morning and I've seen reports of others too
before this was committed) so I've reverted it for now.