> On Sep 8, 2017, at 4:00 PM, matthew green <m...@eterna.com.au> wrote:
>
>> Is the answer "it's using an ISA with 64-bit registers and addresses"?
>> This actually can be broken down into the "registers" and "addresses"
>> portion, but, in practice, the two tend to go together. (Always true
>> on most "64-bit" ports, a real question on amd64 (and others, if any)
>> which support 32-bit userland.)
>
> actually -- our mips64 ports largely use N32 userland, which
> is 64 bit registers and 32 bit addresses. this is also what
> linux calls "x32" for x86 platforms. obviously, this does
> require a 64 bit cpu.
That's why I asked "what does 'is 64-bit' mean". Your previous reference to
LP64 answers the question "does this program use 64 bit addresses". There are
at least two other possible questions: (a) does this program have access to 64
bit registers, and (b) can this program do operations such as arithmetic on 64
bit integers. (a) presumably implies (b) but the two are not equivalent. For
example, N32 is (a) and (b) but O32 -- the old "mips32" port -- is (b) but not
(a).
paul
