On Mon, Oct 8, 2012 at 5:01 PM, Nathan Froyd <froy...@mozilla.com> wrote: > ----- Original Message ----- >> Btw, as for Richards idea of conditionally placing the length field >> in >> rtx_def looks like overkill to me. These days we'd merely want to >> optimize for 64bit hosts, thus unconditionally adding a 32 bit >> field to rtx_def looks ok to me (you can wrap that inside a union to >> allow both descriptive names and eventual different use - see what >> I've done to tree_base) > > IMHO, unconditionally adding that field isn't "optimize for 64-bit > hosts", but "gratuitously make one of the major compiler data > structures bigger on 32-bit hosts". Not everybody can cross-compile > from a 64-bit host. And even those people who can don't necessarily > want to. Please try to consider what's best for all the people who > use GCC, not just the cases you happen to be working with every day.
The challenge would of course be to have the overhead only for a minority of all RTX codes. After all that 32bits are free to be used for every one. And I would not consider RTX a 'major compiler data structure' - of course that makes the whole issue somewhat moot ;) Richard. > -Nathan