Re: Keeping other stuff with addresses (was: What is an N-bit machine?)

On Sat, 30 Nov 2024 16:57:56 GMT
anton@mips.complang.tuwien.ac.at (Anton Ertl) wrote:

Thomas Koenig <tkoenig@netcologne.de> writes:

Anton Ertl <anton@mips.complang.tuwien.ac.at> schrieb: 

anton@mips.complang.tuwien.ac.at (Anton Ertl) writes: 

John Levine <johnl@taugh.com> writes: 

These days I'd say the relevant N is the size of arithmetic
registers but a lot of marketers appear to disagree with me. 

>
Which arithmetic registers on an Intel processor?  The 64 bits of a
GPR?  The 128 bits of an XMM register?  The 256 bits of a YMM
register?  The 512 bits of a ZMM register? 

>
The Cray-1 is even more interesting in that respect.  Is it a
4096-bit machine? 

>
If you consider the widest arithmetic it is capable of in one piece,
it is a 64-bit machine. 

 
That's not John Levine's criterion.
 
BTW, with your criterion, the Zen5 in the Ryzen AI 370HX is a 256-bit
machine, while the Zen5 in the Ryzen 9600X is a 512-bit machine.
According to John Levine's criterion they are both 512-bit machines.
According to me they are both 64-bit machines.  John Levine's and my
criteria are architectural, yours is implementation-oriented.
 
- anton

John Levine said "arythmetic". Not logic, not move, not swizzle, not
load/store. The widest arythmetic on Intel/AMD is 64 bits for inputs and
128 bits for output (integer multiplication).
On IBM processors, both z and POWER, they have arithmetic instructions
with 128-bit inputs. I think, on POWER some of them are even integer
arithmetic. Not sure about z.