http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53948
--- Comment #10 from Jeffrey A. Law <law at redhat dot com> 2013-02-08 13:19:46 UTC --- Right, REG_EXPR gets the underlying decl, but without access to tree.h we can't do anything useful with the decl. The whole point of Steven's patch which caused this regression was to avoid sucking in tree.h into ira-conflicts and other backend files. So the little helper just needs to live in expr.c or similar location where we can peek at the contents of the decl. The alternate is something like Steven's follow-up patch to create REG_FUNCTION_PARM_P which gives us better separation at the expense of using bits in the base rtl structure.
