On Apr 28, 2009, at 10:02 AM, Landon Curt Noll wrote:
> Matt's idea is a reasonable compromise: to keep the tag field
> unchanged and increase the type field size to 4 bytes.
>
> chongo () /\oo/\
>
I agree and will generalize. We just all agree that things come in 32-
bit quantities.
The only possible revision to this would be to do some 64-bit
alignment. I mention this because there are/were machines (Alpha being
one) that really liked 64-bit alignment.
I am *not* suggesting making type/tag etc. be 64-bits. On such a
machine, a pair of 32-bit quantities it fine because fetch-then-split
is fast. The difficulty would be in an unaligned fetch or store. What
you'd want to do would be to pad strings, bignums, etc. out to 64 bits.
I bring it up because if we do that, now is the time.
Jon
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