On 10/8/2012 11:01 AM, Nathan Froyd 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.
I think that's rasonable in general, but as time goes on, and every
$300 laptop is 64-bit capable, one should not go TOO far out of the
way trying to make sure we can compile everything on a 32-bit machine.
After all, we don't try to ensure we can compile on a 16-bit machine
though when I helped write the Realia COBOL compiler, it was a major
consideration that we had to be able to compile arbitrarily large
programs on a 32-bit machine with one megabyte of memory. That was
achieved at the time, but is hardly relevant now!
