- ;; FIXME: is this inefficient? Is there a better way of writing
- ;; it? (fixnum tagging is done with LEA). We can't use SHL
- ;; because we either scribble over the source register or briefly
- ;; have a non-descriptor in a descriptor register, unless we
- ;; introduce a temporary.
- (inst imul y x (ash 1 n-widetag-bits))